source: lib/libtrace.h.in @ 3c828b8

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1/*
2 * This file is part of libtrace
3 *
4 * Copyright (c) 2007-2015 The University of Waikato, Hamilton,
5 * New Zealand.
6 *
7 * Authors: Daniel Lawson
8 *          Perry Lorier
9 *          Shane Alcock
10 *          Richard Sanger
11 *
12 * All rights reserved.
13 *
14 * This code has been developed by the University of Waikato WAND
15 * research group. For further information please see http://www.wand.net.nz/
16 *
17 * libtrace is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
21 *
22 * libtrace is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
25 * GNU General Public License for more details.
26 *
27 * You should have received a copy of the GNU General Public License
28 * along with libtrace; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
30 *
31 * $Id$
32 *
33 */
34
35#ifndef LIBTRACE_H
36#define LIBTRACE_H
37
38/** @file
39 *
40 * @brief Trace file processing library header
41 *
42 * @author Daniel Lawson
43 * @author Perry Lorier
44 * @author Shane Alcock
45 * @author Richard Sanger
46 *
47 * @version $Id$
48 *
49 * This library provides a per packet interface into a trace file, or a live
50 * captures.  It supports ERF, DAG cards, PCAP, Linux and BSD native sockets,
51 * legacy ERF formats etc.
52 *
53 * @par Usage
54 * See the example/ directory in the source distribution for some simple
55 * examples
56 *
57 * @par Linking
58 * To use this library you need to link against libtrace by passing -ltrace
59 * to your linker.
60 *
61 * See libtrace_parallel.h for a description of the parallel API that allows
62 * programmers to spread packet processing across multiple threads.
63 *
64 */
65
66#include <sys/types.h>
67#include <stddef.h>
68#include <stdio.h>
69/* Compile time assertion. Sourced from:
70 * http://www.pixelbeat.org/programming/gcc/static_assert.html */
71#define ct_assert(e) extern char (*ct_assert(void)) [sizeof(char[1 - 2*!(e)])]
72
73#ifndef WIN32
74#include <sys/time.h>
75#endif
76
77/* Deal with missing byte order macros */
78#include <sys/param.h>
79
80#if defined(BYTE_ORDER) && !defined(__BYTE_ORDER)
81#define __BYTE_ORDER    BYTE_ORDER
82#endif
83
84#if defined(BIG_ENDIAN) && !defined(__BIG_ENDIAN)
85#define __BIG_ENDIAN    BIG_ENDIAN
86#endif
87
88#if defined(LITTLE_ENDIAN) && !defined(__LITTLE_ENDIAN)
89#define __LITTLE_ENDIAN LITTLE_ENDIAN
90#endif
91
92#ifdef WIN32
93#   include <winsock2.h>
94#   include <ws2tcpip.h>
95    typedef short sa_family_t;
96    /* Make up for a lack of stdbool.h */
97#    define bool signed char
98#    define false 0
99#    define true 1
100#    if !defined(ssize_t)
101     /* XXX: Not 64-bit safe! */
102#    define ssize_t int
103#    endif   
104#else
105#    include <netinet/in.h>
106
107#ifndef __cplusplus
108#    include <stdbool.h>
109#endif
110
111#    include <sys/types.h>
112#    include <sys/socket.h>
113#endif
114
115/** API version as 2 byte hex digits, eg 0xXXYYZZ */
116#define LIBTRACE_API_VERSION \
117            ((@LIBTRACE_MAJOR@<<16)|(@LIBTRACE_MID@<<8)|(@LIBTRACE_MINOR@))
118
119/** This used to be replaced with the current SVN revision number when
120 * 'make dist' was invoked to create a distributable tarball. We don't use
121 * SVN anymore and there probably isn't any need to know the exact revision
122 * number either these days. */
123#define LIBTRACE_SVN_REVISION LIBTRACE_API_VERSION
124
125/** DAG driver version installed on the current system */
126#define DAG_DRIVER_V "@DAG_VERSION_NUM@"
127
128/**
129  * A version of assert that always runs the first argument even
130  * when not debugging, however only asserts the condition if debugging
131  * Intended for use mainly with pthread locks etc. which have error
132  * returns but *should* never actually fail.
133  */
134#ifdef NDEBUG
135#define ASSERT_RET(run, cond) run
136#else
137#define ASSERT_RET(run, cond) assert(run cond)
138//#define ASSERT_RET(run, cond) run
139#endif
140   
141#ifdef __cplusplus
142extern "C" {
143#endif
144
145#ifdef _MSC_VER
146    /* define the following from MSVC's internal types */
147    typedef             __int8  int8_t;
148    typedef             __int16 int16_t;
149    typedef             __int32 int32_t;
150    typedef             __int64 int64_t;
151    typedef unsigned    __int8  uint8_t;
152    typedef unsigned    __int16 uint16_t;
153    typedef unsigned    __int32 uint32_t;
154    typedef unsigned    __int64 uint64_t;
155   
156    /* Windows pads bitfields out to to the size of their parent type
157     * however gcc warns that this doesn't meet with the iso C specification
158     * so produces warnings for this behaviour.  sigh.
159     */
160    #define LT_BITFIELD8        uint8_t
161    #define LT_BITFIELD16       uint16_t
162    #define LT_BITFIELD32       uint32_t
163    #define LT_BITFIELD64       uint64_t
164#else
165    #ifdef HAVE_STDINT_H
166        #   include <stdint.h>
167    #endif
168    /* GCC warns if the bitfield type is not "unsigned int", however windows
169     * generates incorrect code for this (see above), so we define these
170     * macros.  How Hideous.  So much for C's portability.
171     */
172    #define LT_BITFIELD8        unsigned int
173    #define LT_BITFIELD16       unsigned int
174    #define LT_BITFIELD32       unsigned int
175    #define LT_BITFIELD64       unsigned int
176#endif
177
178/* Ensure these gcc optimisation attributes are defined consistently,
179 * without requiring users to need to have access to the config.h
180 * generated by running configure.
181 */
182
183#define LT_USE_PACKED @HAVE_ATTRIBUTE_PACKED@
184#define LT_USE_UNUSED @HAVE_ATTRIBUTE_UNUSED@
185#define LT_USE_DEPRECATED @HAVE_ATTRIBUTE_DEPRECATED@
186#define LT_USE_PURE @HAVE_ATTRIBUTE_PURE@
187#define LT_USE_PRINTF @HAVE_ATTRIBUTE_FORMAT@
188#define LT_USE_VISIBILITY @HAVE_VISIBILITY@
189
190#if LT_USE_PACKED
191#  define PACKED __attribute__((packed))
192#else
193#  define PACKED
194#endif
195
196#if LT_USE_UNUSED
197#  define UNUSED __attribute__((unused))
198#else
199#  define UNUSED
200#endif
201
202#if LT_USE_DEPRECATED
203#  define DEPRECATED __attribute__((deprecated))
204#else
205#  define DEPRECATED
206#endif
207
208#if LT_USE_PURE
209#  define SIMPLE_FUNCTION __attribute__((pure))
210#else
211#  define SIMPLE_FUNCTION
212#endif
213
214#if LT_USE_PRINTF
215#  define PRINTF(formatpos, argpos) __attribute__((format(printf,formatpos, argpos)))
216#else
217#  define PRINTF(formatpos, argpos)
218#endif
219
220#ifndef CACHE_LINE_SIZE
221#define CACHE_LINE_SIZE 64
222#endif
223#define ALIGN_STRUCT(x) __attribute__((aligned(x)))
224
225#ifdef _MSC_VER
226    #ifdef LT_BUILDING_DLL
227        #define DLLEXPORT __declspec(dllexport)
228    #else
229        #define DLLEXPORT __declspec(dllimport)
230    #endif
231    #define DLLLOCAL
232#else
233    #ifndef DLLEXPORT
234        #if LT_USE_VISIBILITY && LT_BUILDING_DLL
235            #define DLLEXPORT __attribute__ ((visibility("default")))
236            #define DLLLOCAL __attribute__ ((visibility("hidden")))
237        #else
238            #define DLLEXPORT
239            #define DLLLOCAL
240        #endif
241    #endif
242#endif
243
244
245/** Opaque structure holding information about an output trace */
246typedef struct libtrace_out_t libtrace_out_t;
247
248/** Opaque structure holding information about a trace */
249typedef struct libtrace_t libtrace_t;
250
251/** Opaque structure holding information about a bpf filter */
252typedef struct libtrace_filter_t libtrace_filter_t;
253
254/** Opaque structure holding information about libtrace thread */
255typedef struct libtrace_thread_t libtrace_thread_t;
256
257/** Opaque structure holding callback functions for libtrace threads */
258typedef struct callback_set libtrace_callback_set_t;
259
260/** If the packet has allocated its own memory the buffer_control should be
261 * set to TRACE_CTRL_PACKET, so that the memory will be freed when the packet
262 * is destroyed. If the packet has been zero-copied out of memory owned by
263 * something else, e.g. a DAG card, it should be TRACE_CTRL_EXTERNAL.
264 *
265 * @note The letters p and e are magic numbers used to detect if the packet
266 * wasn't created properly.
267 */
268typedef enum {
269        TRACE_CTRL_PACKET='p',  /**< Buffer memory is owned by the packet */
270        TRACE_CTRL_EXTERNAL='e' /**< Buffer memory is owned by an external source */
271} buf_control_t;
272
273/** The size of a packet's buffer when managed by libtrace */
274#define LIBTRACE_PACKET_BUFSIZE 65536
275
276/** Libtrace error information */
277typedef struct trace_err_t{
278        int err_num;            /**< error code */
279        char problem[1024];     /**< the format, uri etc that caused the error for reporting purposes */
280} libtrace_err_t;
281
282/** Enumeration of error codes */
283enum {
284        /** No Error has occurred.... yet. */
285        TRACE_ERR_NOERROR       = 0,
286        /** The URI passed to trace_create() is unsupported, or badly formed */
287        TRACE_ERR_BAD_FORMAT    = -1,
288        /** The trace failed to initialise */
289        TRACE_ERR_INIT_FAILED   = -2,
290        /** Unknown config option */
291        TRACE_ERR_UNKNOWN_OPTION= -3,
292        /** This output uri cannot write packets of this type */
293        TRACE_ERR_NO_CONVERSION = -4,
294        /** This packet is corrupt, or unusable for the action required */
295        TRACE_ERR_BAD_PACKET    = -5,
296        /** Option known, but unsupported by this format */
297        TRACE_ERR_OPTION_UNAVAIL= -6,
298        /** This feature is unsupported */
299        TRACE_ERR_UNSUPPORTED   = -7,
300        /** Illegal use of the API */
301        TRACE_ERR_BAD_STATE     = -8,
302        /** Failed to compile a BPF filter */
303        TRACE_ERR_BAD_FILTER    = -9,
304        /** RT communication breakdown */
305        TRACE_ERR_RT_FAILURE    = -10,
306        /** Compression format unsupported */
307        TRACE_ERR_UNSUPPORTED_COMPRESS  = -11,
308        /** Wandio has returned an error */
309        TRACE_ERR_WANDIO_FAILED = -12,
310        /** Input URI (file) not found */
311        TRACE_ERR_URI_NOT_FOUND = -13,
312        /** NULL passed to create trace **/
313        TRACE_ERR_URI_NULL = -14,
314        /** NULL trace passed to trace_start **/
315        TRACE_ERR_NULL_TRACE = -15,
316        /** Unable to finish last packet in trace_pause **/
317        TRACE_ERR_PAUSE_FIN = -16,
318        /** Packet is NULL **/
319        TRACE_ERR_NULL_PACKET = -17,
320        /** Filter is NULL **/
321        TRACE_ERR_NULL_FILTER = -18,
322        /** Buffer is NULL **/
323        TRACE_ERR_NULL_BUFFER = -19,
324        /** Trace stats err **/
325        TRACE_ERR_STAT = -20,
326        /** Unable to create deadtrace **/
327        TRACE_ERR_CREATE_DEADTRACE = -21,
328        /** Bad linktype **/
329        TRACE_ERR_BAD_LINKTYPE = -22,
330        /** Bad IO for the trace **/
331        TRACE_ERR_BAD_IO = -23,
332        /** Trace has bad header **/
333        TRACE_ERR_BAD_HEADER = -24,
334        /** Trace err seeking by erf **/
335        TRACE_ERR_SEEK_ERF = -25,
336        /** Trace err combiner **/
337        TRACE_ERR_COMBINER = -26,
338        /** Error pausing processing thread **/
339        TRACE_ERR_PAUSE_PTHREAD = -27,
340        /** Error with trace thread **/
341        TRACE_ERR_THREAD = -28,
342        /** Thread in unexpecting state **/
343        TRACE_ERR_THREAD_STATE = -29,
344        /** Trace configuration error **/
345        TRACE_ERR_CONFIG = -30,
346        /** NULL passed misc **/
347        TRACE_ERR_NULL = -31,
348        /** Err with trace output file **/
349        TRACE_ERR_OUTPUT_FILE = -32,
350};
351
352/** Enumeration of DLTs supported by libtrace
353 */
354typedef enum {
355        /* Special value used to indicate a failure to convert to libtrace
356         * DLT */
357        TRACE_DLT_ERROR = -1,
358
359        /** pcap documents this as having the Address Family value in host
360          * byte order as the framing.  Ugly? Yes.
361          */
362        TRACE_DLT_NULL = 0,
363        TRACE_DLT_EN10MB = 1,
364        TRACE_DLT_PPP = 9,
365        TRACE_DLT_ATM_RFC1483 = 11,
366
367        /** Ok, so OpenBSD has a different value for DLT_RAW as the rest of
368         * the planet, so detect this.  When reading to/from files we should
369         * be using TRACE_DLT_LINKTYPE_RAW instead. When talking about DLT's
370         * inside libtrace tho, we should be using /these/ DLT's.
371         */
372#ifdef __OpenBSD__
373        TRACE_DLT_OPENBSD_LOOP=12,
374        TRACE_DLT_RAW = 14,
375#else
376        TRACE_DLT_RAW = 12,
377        TRACE_DLT_OPENBSD_LOOP = 108,
378#endif
379        TRACE_DLT_PPP_SERIAL = 50,
380        TRACE_DLT_LINKTYPE_RAW = 101, /**< See TRACE_DLT_RAW for explanations of pain. */
381        TRACE_DLT_C_HDLC = 104,
382        TRACE_DLT_IEEE802_11 = 105,
383        TRACE_DLT_LINUX_SLL = 113,
384        TRACE_DLT_PFLOG = 117,
385        TRACE_DLT_IEEE802_11_RADIO = 127 /**< Radiotap */
386} libtrace_dlt_t ;
387
388/** Enumeration of link layer types supported by libtrace */
389typedef enum {
390       TRACE_TYPE_CONTENT_INVALID = -2, /**< Packet contents are not valid */
391       TRACE_TYPE_UNKNOWN = -1,         /**< Unable to determine link type */
392    /* TRACE_TYPE_LEGACY = 0            Obsolete */
393       TRACE_TYPE_HDLC_POS = 1,         /**< HDLC over POS */
394       TRACE_TYPE_ETH = 2,              /**< 802.3 style Ethernet */
395       TRACE_TYPE_ATM = 3,              /**< ATM frame */
396       TRACE_TYPE_80211 = 4,            /**< 802.11 frames */
397       TRACE_TYPE_NONE = 5,             /**< Raw IP frames */
398       TRACE_TYPE_LINUX_SLL = 6,        /**< Linux "null" framing */
399       TRACE_TYPE_PFLOG = 7,            /**< FreeBSD's PFlog */
400    /* TRACE_TYPE_LEGACY_DEFAULT        Obsolete */
401       TRACE_TYPE_POS = 9,              /**< Packet-over-SONET */
402    /* TRACE_TYPE_LEGACY_ATM            Obsolete */
403    /* TRACE_TYPE_LEGACY_ETH            Obsolete */
404       TRACE_TYPE_80211_PRISM = 12,     /**< 802.11 Prism frames */
405       TRACE_TYPE_AAL5 = 13,            /**< ATM Adaptation Layer 5 frames */
406       TRACE_TYPE_DUCK = 14,         /**< Pseudo link layer for DUCK packets */
407       TRACE_TYPE_80211_RADIO = 15,  /**< Radiotap + 802.11 */
408       TRACE_TYPE_LLCSNAP = 16,      /**< Raw LLC/SNAP */
409       TRACE_TYPE_PPP = 17,          /**< PPP frames */
410       TRACE_TYPE_METADATA = 18,        /**< WDCAP-style meta-data */
411       TRACE_TYPE_NONDATA = 19,         /**< Not a data packet */
412       TRACE_TYPE_OPENBSD_LOOP = 20,    /**< OpenBSD loopback */
413       TRACE_TYPE_ERF_META = 21, /**< ERF Provenance metadata record */
414       TRACE_TYPE_ETSILI = 22,  /**< ETSI Lawful Intercept */
415       TRACE_TYPE_PCAPNG_META = 23,     /** PCAPNG meta packet */
416} libtrace_linktype_t;
417
418/** RT protocol base format identifiers.
419 * This is used to describe the capture format of the packet is being sent
420 * using the RT protocol.
421 */
422enum base_format_t {
423        TRACE_FORMAT_ERF          =1,   /**< ERF (DAG capture format) */
424        TRACE_FORMAT_PCAP         =2,   /**< Live PCAP capture */
425        TRACE_FORMAT_PCAPFILE     =3,   /**< PCAP trace file */
426        TRACE_FORMAT_WAG          =4,   /**< WAG live capture (Obsolete) */
427        TRACE_FORMAT_RT           =5,   /**< RT network protocol */
428        TRACE_FORMAT_LEGACY_ATM   =6,   /**< Legacy ERF for ATM capture */
429        TRACE_FORMAT_LEGACY_POS   =7,   /**< Legacy ERF for POS capture */
430        TRACE_FORMAT_LEGACY_ETH   =8,   /**< Legacy ERF for ETH capture */
431        TRACE_FORMAT_LINUX_NATIVE =9,   /**< Linux native interface capture */
432        TRACE_FORMAT_DUCK         =10,  /**< DAG Clock information */
433        TRACE_FORMAT_BPF          =11,  /**< BSD native interface capture */
434        TRACE_FORMAT_TSH          =12,  /**< TSH trace format */
435        TRACE_FORMAT_ATMHDR       =13,  /**< Legacy ATM header capture */
436        TRACE_FORMAT_LEGACY_NZIX  =14,  /**< Legacy format used for NZIX traces */
437        TRACE_FORMAT_LINUX_RING   =15,  /**< Linux native interface capture PACKET_MMAP */
438        TRACE_FORMAT_RAWERF       =16,  /**< Special format for reading uncompressed ERF traces without checking for compression */
439        TRACE_FORMAT_DPDK     =17, /**< The Intel Data Plane Development Kit format */
440        TRACE_FORMAT_PCAPNG     =18,    /**< PCAP-NG trace file */
441        TRACE_FORMAT_NDAG       =19,    /**< DAG multicast over a network */
442        TRACE_FORMAT_DPDK_NDAG       =20,    /**< DAG multicast over a network, received via DPDK */
443        TRACE_FORMAT_ETSILIVE     =21,  /**< ETSI LI over a network */
444        TRACE_FORMAT_UNKNOWN      =22,  /** Unknown format */
445};
446
447/** RT protocol packet types */
448typedef enum {
449        TRACE_RT_HELLO          =1, /**< Connection accepted */
450        TRACE_RT_START          =2, /**< Request for data transmission to begin
451                                    */
452        TRACE_RT_ACK            =3, /**< Data acknowledgement */
453        TRACE_RT_STATUS         =4, /**< Fifo status packet */
454        TRACE_RT_DUCK           =5, /**< Dag duck info packet */
455        TRACE_RT_END_DATA       =6, /**< Server is exiting message */
456        TRACE_RT_CLOSE          =7, /**< Client is exiting message */
457        TRACE_RT_DENY_CONN      =8, /**< Connection has been denied */
458        TRACE_RT_PAUSE          =9, /**< Request server to suspend sending data
459                                     */
460        TRACE_RT_PAUSE_ACK      =10,/**< Server is paused message */
461        TRACE_RT_OPTION         =11,/**< Option request */
462        TRACE_RT_KEYCHANGE      =12,/**< Anonymisation key has changed */
463        TRACE_RT_DUCK_2_4       =13,/**< Dag 2.4 Duck */
464        TRACE_RT_DUCK_2_5       =14,/**< Dag 2.5 Duck */
465        TRACE_RT_LOSTCONN       =15,/**< Lost connection to server */
466        TRACE_RT_SERVERSTART    =16,/**< Reliable server has been restarted */
467        TRACE_RT_CLIENTDROP     =17,/**< Reliable client was lost */
468        TRACE_RT_METADATA       =18,/**< Packet contains server meta-data */
469        TRACE_RT_DUCK_5_0       =19,/**< Dag 5.0 Duck */
470        TRACE_RT_PCAPNG_META    =20,/**< Metadata for a PCAP NG input source */
471        TRACE_RT_ERF_META       =21,/**< Metadata for a ERF input source */
472
473        /** Not actually used - all DATA types begin from this value */
474        TRACE_RT_DATA_SIMPLE    = 1000,
475       
476        /** RT is encapsulating an ERF capture record */
477        TRACE_RT_DATA_ERF       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_ERF,
478        /** RT is encapsulating a WAG capture record */
479        TRACE_RT_DATA_WAG       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_WAG,
480        /** RT is encapsulating a Legacy ATM capture record */
481        TRACE_RT_DATA_LEGACY_ATM=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_ATM,
482        /** RT is encapsulating a Legacy POS capture record */
483        TRACE_RT_DATA_LEGACY_POS=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_POS,
484        /** RT is encapsulating a Legacy ETH capture record */
485        TRACE_RT_DATA_LEGACY_ETH=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_ETH,
486        /** RT is encapsulating a Linux native capture record */
487        TRACE_RT_DATA_LINUX_NATIVE=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LINUX_NATIVE,
488        /** RT is encapsulating a BSD native capture record */
489        //TRACE_RT_DATA_BPF       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_BPF,
490        /** RT is encapsulating a TSH capture record */
491        TRACE_RT_DATA_TSH       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_TSH,
492        /** RT is encapsulating an ATM header capture record */
493        TRACE_RT_DATA_ATMHDR = TRACE_RT_DATA_SIMPLE + TRACE_FORMAT_ATMHDR,
494        /** RT is encapsulating a Legacy NZIX capture record */
495        TRACE_RT_DATA_LEGACY_NZIX=TRACE_RT_DATA_SIMPLE + TRACE_FORMAT_LEGACY_NZIX,
496        /** RT is encapsulating a Linux native PACKET_MMAP capture record */
497        TRACE_RT_DATA_LINUX_RING=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LINUX_RING,
498    /** RT is encapsulating a Intel DPDK capture record */
499        TRACE_RT_DATA_DPDK=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_DPDK,
500
501        TRACE_RT_DATA_ETSILI = TRACE_RT_DATA_SIMPLE + TRACE_FORMAT_ETSILIVE,
502
503        /** As PCAP does not store the linktype with the packet, we need to
504         * create a separate RT type for each supported DLT, starting from
505         * this value */
506        TRACE_RT_DATA_DLT               = 2000,
507        /** RT is encapsulating a PCAP capture record with a NULL linktype */
508        TRACE_RT_DLT_NULL               =TRACE_RT_DATA_DLT+TRACE_DLT_NULL,
509        /** RT is encapsulating a PCAP capture record with an Ethernet
510         * linktype */
511        TRACE_RT_DLT_EN10MB             =TRACE_RT_DATA_DLT+TRACE_DLT_EN10MB,
512        /** RT is encapsulating a PCAP capture record with an 802.11
513         * linktype */
514        TRACE_RT_DLT_IEEE802_11         =TRACE_RT_DATA_DLT+TRACE_DLT_IEEE802_11,
515        /** RT is encapsulating a PCAP capture record with a Linux SLL
516         * linktype */
517        TRACE_RT_DLT_LINUX_SLL          =TRACE_RT_DATA_DLT+TRACE_DLT_LINUX_SLL,
518        /** RT is encapsulating a PCAP capture record with a PFlog linktype */
519        TRACE_RT_DLT_PFLOG              =TRACE_RT_DATA_DLT+TRACE_DLT_PFLOG,
520        /** RT is encapsulating a PCAP capture record with an AAL5 linktype */
521        TRACE_RT_DLT_ATM_RFC1483        =TRACE_RT_DATA_DLT+TRACE_DLT_ATM_RFC1483,
522        /** Unused value marking the end of the valid range for PCAP RT
523         * encapsulation */
524        TRACE_RT_DATA_DLT_END           = 2999,
525        /** BPF does not store the linktype with the packet, so we need a
526         * separate RT type for each supported DLT. This value represents the
527         * starting point */
528        TRACE_RT_DATA_BPF               = 3000,
529
530        TRACE_RT_BPF_NULL               = TRACE_RT_DATA_BPF+TRACE_DLT_NULL,
531        TRACE_RT_BPF_EN10MB             = TRACE_RT_DATA_BPF+TRACE_DLT_EN10MB,
532        TRACE_RT_BPF_IEEE802_11         = TRACE_RT_DATA_BPF+TRACE_DLT_IEEE802_11,
533        TRACE_RT_BPF_PFLOG              =TRACE_RT_DATA_BPF+TRACE_DLT_PFLOG,
534        TRACE_RT_BPF_ATM_RFC1483        =TRACE_RT_DATA_BPF+TRACE_DLT_ATM_RFC1483,
535
536        TRACE_RT_DATA_BPF_END           = 3999,
537
538        TRACE_RT_DATA_PCAPNG            = 4000,
539        TRACE_RT_DATA_PCAPNG_END        = 4499,
540        /** Unused value marking the end of the valid range for all RT packet
541         * types */
542        TRACE_RT_LAST                   = 4500
543} libtrace_rt_types_t;
544
545/** IP Protocol values */
546typedef enum {
547        TRACE_IPPROTO_IP        = 0,    /**< IP pseudo protocol number */
548        TRACE_IPPROTO_ICMP      = 1,    /**< Internet Control Message protocol */
549        TRACE_IPPROTO_IGMP      = 2,    /**< Internet Group Management Protocol */
550        TRACE_IPPROTO_IPIP      = 4,    /**< IP encapsulated in IP */
551        TRACE_IPPROTO_TCP       = 6,    /**< Transmission Control Protocol */
552        TRACE_IPPROTO_UDP       = 17,   /**< User Datagram Protocol */
553        TRACE_IPPROTO_IPV6      = 41,   /**< IPv6 over IPv4 */
554        TRACE_IPPROTO_ROUTING   = 43,   /**< IPv6 Routing header */
555        TRACE_IPPROTO_FRAGMENT  = 44,   /**< IPv6 Fragmentation header */
556        TRACE_IPPROTO_RSVP      = 46,   /**< Resource Reservation Protocol */
557        TRACE_IPPROTO_GRE       = 47,   /**< General Routing Encapsulation */
558        TRACE_IPPROTO_ESP       = 50,   /**< Encapsulated Security Payload [RFC2406] */
559        TRACE_IPPROTO_AH        = 51,   /**< Authentication Header [RFC2402] */
560        TRACE_IPPROTO_ICMPV6    = 58,   /**< ICMPv6 */
561        TRACE_IPPROTO_NONE      = 59,   /**< IPv6 no next header */
562        TRACE_IPPROTO_DSTOPTS   = 60,   /**< IPv6 destination options */
563        TRACE_IPPROTO_OSPF      = 89,   /**< Open Shortest Path First routing protocol */
564        TRACE_IPPROTO_PIM       = 103,  /**< Protocol Independant Multicast */
565        TRACE_IPPROTO_SCTP      = 132   /**< Stream Control Transmission Protocol */
566} libtrace_ipproto_t;
567
568/** Ethertypes supported by Libtrace */
569typedef enum {
570        /* Numbers <=1500 are of course, LLC/SNAP */
571        TRACE_ETHERTYPE_LOOPBACK= 0x0060,       /**< Ethernet Loopback */
572        TRACE_ETHERTYPE_IP      = 0x0800,       /**< IPv4 */
573        TRACE_ETHERTYPE_ARP     = 0x0806,       /**< Address resolution protocol */
574        TRACE_ETHERTYPE_RARP    = 0x8035,       /**< Reverse ARP */
575        TRACE_ETHERTYPE_8021Q   = 0x8100,       /**< 802.1q VLAN Extended Header */
576        TRACE_ETHERTYPE_IPV6    = 0x86DD,       /**< IPv6 */
577        TRACE_ETHERTYPE_MPLS    = 0x8847,       /**< MPLS Unicast traffic */
578        TRACE_ETHERTYPE_MPLS_MC = 0x8848,       /**< MPLS Multicast traffic */
579        TRACE_ETHERTYPE_PPP_DISC= 0x8863,       /**< PPPoE Service Discovery */
580        TRACE_ETHERTYPE_PPP_SES = 0x8864        /**< PPPoE Session Messages */
581} libtrace_ethertype_t;
582
583typedef struct libtrace_packet_cache {
584        int capture_length;             /**< Cached capture length */
585        int wire_length;                /**< Cached wire length */
586        int payload_length;             /**< Cached payload length */
587        int framing_length;             /**< Cached framing length */
588        void *l2_header;                /**< Cached link header */
589        libtrace_linktype_t link_type;  /**< Cached link type */
590        uint32_t l2_remaining;          /**< Cached link remaining */
591        void *l3_header;                /**< Cached l3 header */
592        uint16_t l3_ethertype;          /**< Cached l3 ethertype */
593        uint32_t l3_remaining;          /**< Cached l3 remaining */
594        void *l4_header;                /**< Cached transport header */
595        uint8_t transport_proto;        /**< Cached transport protocol */
596        uint32_t l4_remaining;          /**< Cached transport remaining */
597} libtrace_packet_cache_t;
598
599/** The libtrace packet structure. Applications shouldn't be
600 * meddling around in here
601 */
602typedef struct libtrace_packet_t {
603        struct libtrace_t *trace;       /**< Pointer to the trace */
604        void *header;                   /**< Pointer to the framing header */
605        void *payload;                  /**< Pointer to the link layer */
606        void *buffer;                   /**< Allocated buffer */
607        libtrace_rt_types_t  type;      /**< RT protocol type for the packet */
608        buf_control_t buf_control;      /**< Describes memory ownership */
609        libtrace_packet_cache_t cached; /**< Cached packet properties / headers */
610        uint64_t order; /**< Notes the order of this packet in relation to the input */
611        uint64_t hash; /**< A hash of the packet as supplied by the user */
612        int error; /**< The error status of pread_packet */
613        uint64_t internalid;            /** Internal identifier for the pkt */
614        void *srcbucket;
615
616        pthread_mutex_t ref_lock;       /**< Lock for reference counter */
617        int refcount;                 /**< Reference counter */
618        int which_trace_start;          /**< Used to match packet to a started instance of the parent trace */
619
620} libtrace_packet_t;
621
622#define IS_LIBTRACE_META_PACKET(packet) (packet->type < TRACE_RT_DATA_SIMPLE)
623
624
625/** Trace directions.
626 * Note that these are the directions used by convention. More directions
627 * are possible, not just these 3, and that they may not conform to this
628 * convention.
629 */
630typedef enum {
631        TRACE_DIR_OUTGOING = 0,         /**< Packets originating "inside" */
632        TRACE_DIR_INCOMING = 1,         /**< Packets originating "outside" */
633        TRACE_DIR_OTHER    = 2,         /**< Packets with an unknown direction, or one that's unknown */
634        TRACE_DIR_UNKNOWN = -1,         /**< No direction information available */
635} libtrace_direction_t;
636
637/** Enumeration of Radiotap fields */
638typedef enum {
639    TRACE_RADIOTAP_TSFT = 0, /**< Timer synchronisation function, in microseconds (uint64) */
640    TRACE_RADIOTAP_FLAGS = 1, /**< Wireless flags (uint8) */
641    TRACE_RADIOTAP_RATE = 2, /**< Bitrate in units of 500kbps (uint8) */
642    TRACE_RADIOTAP_CHANNEL = 3, /**< Frequency in MHz (uint16) and channel flags (uint16) */
643    TRACE_RADIOTAP_FHSS = 4, /**< FHSS hop set (uint8) and hopping pattern (uint8) */
644    TRACE_RADIOTAP_DBM_ANTSIGNAL = 5, /**< Signal power in dBm (int8) */
645    TRACE_RADIOTAP_DBM_ANTNOISE = 6, /**< Noise power in dBm (int8) */
646    TRACE_RADIOTAP_LOCK_QUALITY = 7, /**< Barker Code lock quality (uint16) */
647    TRACE_RADIOTAP_TX_ATTENUATION = 8, /**< TX attenuation as unitless distance from max power (uint16) */
648    TRACE_RADIOTAP_DB_TX_ATTENUATION = 9, /**< TX attenuation as dB from max power (uint16) */
649    TRACE_RADIOTAP_DBM_TX_POWER = 10, /**< TX Power in dBm (int8) */
650    TRACE_RADIOTAP_ANTENNA = 11, /**< Antenna frame was rx'd or tx'd on (uint8) */
651    TRACE_RADIOTAP_DB_ANTSIGNAL = 12, /**< Signal power in dB from a fixed reference (uint8) */
652    TRACE_RADIOTAP_DB_ANTNOISE = 13, /**< Noise power in dB from a fixed reference (uint8) */
653    TRACE_RADIOTAP_RX_FLAGS = 14, /** Properties of received frame (uint16) */
654    TRACE_RADIOTAP_TX_FLAGS = 15, /** Properties of transmitted frame (uint16) */
655    TRACE_RADIOTAP_RTS_RETRIES = 16, /** Number of rts retries frame used (uint8) */
656    TRACE_RADIOTAP_DATA_RETRIES = 17, /** Number of unicast retries a transmitted frame used (uint8) */
657    TRACE_RADIOTAP_EXT = 31
658} libtrace_radiotap_field_t;
659
660
661/** @name Protocol structures
662 * These convenience structures provide portable versions of the headers
663 * for a variety of protocols.
664 * @{
665 */
666
667#ifdef WIN32
668#pragma pack(push)
669#pragma pack(1)
670#endif
671
672/** Generic IP header structure */
673typedef struct libtrace_ip
674{
675#if __BYTE_ORDER == __LITTLE_ENDIAN
676    LT_BITFIELD8 ip_hl:4;               /**< Header Length */
677    LT_BITFIELD8 ip_v:4;                /**< Version */
678#elif __BYTE_ORDER == __BIG_ENDIAN
679    LT_BITFIELD8 ip_v:4;                /**< Version */
680    LT_BITFIELD8 ip_hl:4;               /**< Header Length */
681#else
682#   error "Adjust your <bits/endian.h> defines"
683#endif
684    uint8_t  ip_tos;                    /**< Type of Service */
685    uint16_t ip_len;                    /**< Total Length */
686    int16_t  ip_id;                     /**< Identification */
687    uint16_t ip_off;                    /**< IP Fragment offset (and flags) */
688    uint8_t  ip_ttl;                    /**< Time to Live */
689    uint8_t  ip_p;                      /**< Protocol */
690    uint16_t ip_sum;                    /**< Checksum */
691    struct in_addr ip_src;              /**< Source Address */
692    struct in_addr ip_dst;              /**< Destination Address */
693} PACKED libtrace_ip_t;
694
695/** IPv6 header extension structure */
696typedef struct libtrace_ip6_ext
697{
698        uint8_t nxt;    /**< Next header */
699        uint8_t len;    /**< Length of the current header */
700} PACKED libtrace_ip6_ext_t;
701
702/** IPv6 fragmentation header */
703typedef struct libtrace_ip6_frag
704{
705        uint8_t nxt;    /**< Next header */
706        uint8_t res;    /**< Reserved */
707        uint16_t frag_off;      /**< Fragment Offset (includes M flag) */
708        uint32_t ident; /** Fragment identification */
709} PACKED libtrace_ip6_frag_t;
710
711/** Generic IPv6 header structure
712 *
713 * @note The flow label field also includes the Version and Traffic Class
714 * fields, because we haven't figured out a nice way to deal with fields
715 * crossing byte boundaries on both Big and Little Endian machines */
716typedef struct libtrace_ip6
717{
718    uint32_t flow;                      /**< Flow label */
719    uint16_t plen;                      /**< Payload length */
720    uint8_t nxt;                        /**< Next header */
721    uint8_t hlim;                       /**< Hop limit */
722    struct in6_addr ip_src;             /**< Source address */
723    struct in6_addr ip_dst;             /**< Destination address */
724} PACKED libtrace_ip6_t;
725
726/** Generic TCP header structure */
727typedef struct libtrace_tcp
728  {
729    uint16_t source;            /**< Source Port */
730    uint16_t dest;              /**< Destination port */
731    uint32_t seq;               /**< Sequence number */
732    uint32_t ack_seq;           /**< Acknowledgement Number */
733#  if __BYTE_ORDER == __LITTLE_ENDIAN
734    LT_BITFIELD8 ecn_ns:1;      /**< ECN Nonce Sum */
735    LT_BITFIELD8 res1:3;        /**< Reserved bits */
736    LT_BITFIELD8 doff:4;        /**< Data Offset */
737    LT_BITFIELD8 fin:1;         /**< FIN */
738    LT_BITFIELD8 syn:1;         /**< SYN flag */
739    LT_BITFIELD8 rst:1;         /**< RST flag */
740    LT_BITFIELD8 psh:1;         /**< PuSH flag */
741    LT_BITFIELD8 ack:1;         /**< ACK flag */
742    LT_BITFIELD8 urg:1;         /**< URG flag */
743    LT_BITFIELD8 ece:1;         /**< ECN Echo */
744    LT_BITFIELD8 cwr:1;         /**< ECN CWR */
745#  elif __BYTE_ORDER == __BIG_ENDIAN
746    LT_BITFIELD8 doff:4;        /**< Data offset */
747    LT_BITFIELD8 res1:3;        /**< Reserved bits */
748    LT_BITFIELD8 ecn_ns:1;      /**< ECN Nonce Sum */
749    LT_BITFIELD8 cwr:1;         /**< ECN CWR */
750    LT_BITFIELD8 ece:1;         /**< ECN Echo */
751    LT_BITFIELD8 urg:1;         /**< URG flag */
752    LT_BITFIELD8 ack:1;         /**< ACK flag */
753    LT_BITFIELD8 psh:1;         /**< PuSH flag */
754    LT_BITFIELD8 rst:1;         /**< RST flag */
755    LT_BITFIELD8 syn:1;         /**< SYN flag */
756    LT_BITFIELD8 fin:1;         /**< FIN flag */
757#  else
758#   error "Adjust your <bits/endian.h> defines"
759#  endif
760    uint16_t window;            /**< Window Size */
761    uint16_t check;             /**< Checksum */
762    uint16_t urg_ptr;           /**< Urgent Pointer */
763} PACKED libtrace_tcp_t;
764
765/** Generic UDP header structure */
766typedef struct libtrace_udp {
767  uint16_t      source;         /**< Source port */
768  uint16_t      dest;           /**< Destination port */
769  uint16_t      len;            /**< Length */
770  uint16_t      check;          /**< Checksum */
771} PACKED libtrace_udp_t;
772
773/** Generic ICMP header structure */
774typedef struct libtrace_icmp
775{
776  uint8_t type;         /**< Message Type */
777  uint8_t code;         /**< Type Sub-code */
778  uint16_t checksum;            /**< Checksum */
779  union
780  {
781    struct
782    {
783      uint16_t  id;             /**< ID of the Echo request */
784      uint16_t  sequence;       /**< Sequence number of the Echo request */
785    } echo;                     /**< Echo Datagram */
786    uint32_t    gateway;        /**< Gateway Address */
787    struct
788    {
789      uint16_t  unused;         /**< Unused */
790      uint16_t  mtu;            /**< Next-hop MTU */
791    } frag;                     /**< Path MTU Discovery */
792  } un;                         /**< Union for Payloads of Various ICMP Codes */
793} PACKED libtrace_icmp_t;
794
795/** Generic ICMPv6 header structure */
796typedef struct libtrace_icmp6 {
797  uint8_t type;         /**< Message Type */
798  uint8_t code;         /**< Type Sub-code */
799  uint16_t checksum;    /**< Checksum */
800
801  union {
802    struct {
803        uint8_t length;   /**< Length of original datagram content in 64 bit words */
804        uint8_t unused;   /**< Unused */       
805        uint8_t unused1;  /**< Unused */
806    } extend;   /**< Extensions added in RFC 4884 for Time Exceeded and Destination Unreachable Messages */
807
808    uint32_t mtu;       /**< MTU from Packet Too Big Message */
809    uint32_t pointer;   /**< Pointer from Parameter Problem Message */
810    struct {
811        uint16_t id;    /**< Echo Identifier */
812        uint16_t sequence; /**< Echo Sequence Number */
813    } echo; /**< Data required for Echo Request and Reply messages */
814  } un;
815} PACKED libtrace_icmp6_t;
816
817/** Generic LLC/SNAP header structure */
818typedef struct libtrace_llcsnap
819{
820/* LLC */
821  uint8_t dsap;                 /**< Destination Service Access Point */
822  uint8_t ssap;                 /**< Source Service Access Point */
823  uint8_t control;              /**< Control field */
824/* SNAP */
825  LT_BITFIELD32 oui:24;         /**< Organisationally Unique Identifier (scope)*/
826  uint16_t type;                /**< Protocol within OUI */
827} PACKED libtrace_llcsnap_t;
828
829/** 802.3 frame */
830typedef struct libtrace_ether
831{
832  uint8_t ether_dhost[6];       /**< Destination Ether Addr */
833  uint8_t ether_shost[6];       /**< Source Ether Addr */
834  uint16_t ether_type;          /**< Packet Type ID Field (next-header) */
835} PACKED libtrace_ether_t;
836
837/** 802.1Q frame */
838typedef struct libtrace_8021q
839{
840  LT_BITFIELD16 vlan_pri:3;      /**< VLAN User Priority */
841  LT_BITFIELD16 vlan_cfi:1;      /**< VLAN Format Indicator,
842                                   * 0 for ethernet, 1 for token ring */
843  LT_BITFIELD16 vlan_id:12;      /**< VLAN Id */
844  uint16_t vlan_ether_type;      /**< VLAN Sub-packet Type ID Field
845                                   * (next-header)*/
846} PACKED libtrace_8021q_t;
847
848/** ATM User Network Interface (UNI) Cell. */
849typedef struct libtrace_atm_cell
850{
851  LT_BITFIELD32 gfc:4;          /**< Generic Flow Control */
852  LT_BITFIELD32 vpi:8;          /**< Virtual Path Identifier */
853  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
854  LT_BITFIELD32 pt:3;           /**< Payload Type */
855  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
856  LT_BITFIELD32 hec:8;          /**< Header Error Control */
857} PACKED libtrace_atm_cell_t;
858
859/** ATM Network Node/Network Interface (NNI) Cell. */
860typedef struct libtrace_atm_nni_cell
861{
862  LT_BITFIELD32 vpi:12;         /**< Virtual Path Identifier */
863  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
864  LT_BITFIELD32 pt:3;           /**< Payload Type */
865  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
866  LT_BITFIELD32 hec:8;          /**< Header Error Control */
867} PACKED libtrace_atm_nni_cell_t;
868
869/** Captured UNI cell.
870 *
871 * Endace don't capture the HEC, presumably to keep alignment.  This
872 * version of the \ref libtrace_atm_cell is used when dealing with DAG
873 * captures of uni cells.
874 *
875 */
876typedef struct libtrace_atm_capture_cell
877{
878  LT_BITFIELD32 gfc:4;          /**< Generic Flow Control */
879  LT_BITFIELD32 vpi:8;          /**< Virtual Path Identifier */
880  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
881  LT_BITFIELD32 pt:3;           /**< Payload Type */
882  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
883} PACKED libtrace_atm_capture_cell_t;
884
885/** Captured NNI cell.
886 *
887 * Endace don't capture the HEC, presumably to keep alignment.  This
888 * version of the \ref libtrace_atm_nni_cell is used when dealing with DAG
889 * captures of nni cells.
890 *
891 */
892typedef struct libtrace_atm_nni_capture_cell
893{
894  LT_BITFIELD32 vpi:12;         /**< Virtual Path Identifier */
895  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
896  LT_BITFIELD32 pt:3;           /**< Payload Type */
897  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
898  LT_BITFIELD32 hec:8;          /**< Header Error Control */
899} PACKED libtrace_atm_nni_capture_cell_t;
900
901/** PPP header */
902typedef struct libtrace_ppp
903{
904 /* I can't figure out where the hell these two variables come from. They're
905  * definitely not in RFC 1661 which defines PPP. Probably some weird thing
906  * relating to the lack of distinction between PPP, HDLC and CHDLC */
907       
908/* uint8_t address; */          /**< PPP Address (0xFF - All stations) */
909/* uint8_t header;  */          /**< PPP Control (0x03 - Unnumbered info) */
910 uint16_t protocol;             /**< PPP Protocol (htons(0x0021) - IPv4 */
911} PACKED libtrace_ppp_t;
912
913/** PPPoE header */
914typedef struct libtrace_pppoe
915{
916 LT_BITFIELD8 version:4;        /**< Protocol version number */
917 LT_BITFIELD8 type:4;           /**< PPPoE Type */
918 uint8_t code;                  /**< PPPoE Code */
919 uint16_t session_id;           /**< Session Identifier */
920 uint16_t length;               /**< Total Length of the PPP packet */
921} PACKED libtrace_pppoe_t;
922
923/** Libtrace local definition of GRE (Generalised Routing Protocol) header
924 * RFC2890
925 */
926typedef struct libtrace_gre_t
927{
928    uint16_t flags;         /**< Flags and version */
929    uint16_t ethertype;     /**< Payload ethertype */
930    uint16_t checksum;      /**< Optional checksum */
931    uint16_t reserved1;     /**< Optional reserved */
932    uint16_t key;           /**< Optional key (or Tenant Network ID) */
933    uint16_t seq;           /**< Optional sequence number */
934} PACKED libtrace_gre_t;
935
936#define LIBTRACE_GRE_FLAG_CHECKSUM 0x8000
937#define LIBTRACE_GRE_FLAG_KEY      0x2000
938#define LIBTRACE_GRE_FLAG_SEQ      0x1000
939#define LIBTRACE_GRE_FLAG_VERMASK  0x0007
940
941
942/* PPTP GRE (RFC2637) */
943#define LIBTRACE_GRE_FLAG_ACK      0x0080
944#define LIBTRACE_GRE_PPTP_VERSION  0x0001
945
946/** Libtrace local definition of VXLAN Header
947 * (draft-mahalingam-dutt-dcops-vxlan)
948 */
949typedef struct libtrace_vxlan_t
950{
951    uint8_t flags;          /**< Flags */
952    uint8_t reserved1[3];   /**< Reserved */
953    uint8_t vni[3];         /**< VXLAN Network Identifier (VNI) */
954    uint8_t reserved2;
955} PACKED libtrace_vxlan_t;
956
957/** 802.11 header */
958typedef struct libtrace_80211_t {
959#if __BYTE_ORDER == __LITTLE_ENDIAN
960        LT_BITFIELD32      protocol:2;  /**< Protocol Version */
961        LT_BITFIELD32      type:2;      /**< Frame Type */
962        LT_BITFIELD32      subtype:4;   /**< Frame Subtype */
963#else
964        LT_BITFIELD32      subtype:4;   /**< Frame Subtype */
965        LT_BITFIELD32      type:2;      /**< Frame Type */
966        LT_BITFIELD32      protocol:2;  /**< Protocol Version */
967#endif
968
969#if __BYTE_ORDER == __LITTLE_ENDIAN
970        LT_BITFIELD32      to_ds:1;     /**< Packet to Distribution Service */
971        LT_BITFIELD32      from_ds:1;   /**< Packet from Distribution Service */
972        LT_BITFIELD32      more_frag:1; /**< Packet has more fragments */
973        LT_BITFIELD32      retry:1;     /**< Packet is a retry */
974        LT_BITFIELD32      power:1;     /**< Power Management mode */
975        LT_BITFIELD32      more_data:1; /**< More data is buffered at station */
976        LT_BITFIELD32      wep:1;       /**< WEP encryption indicator */
977        LT_BITFIELD32      order:1;     /**< Strictly-Ordered class indicator */
978#else
979        LT_BITFIELD32      order:1;     /**< Strictly-Ordered class indicator */
980        LT_BITFIELD32      wep:1;       /**< WEP encryption indicator */
981        LT_BITFIELD32      more_data:1; /**< More data is buffered at station */
982        LT_BITFIELD32      power:1;     /**< Power Management mode */
983        LT_BITFIELD32      retry:1;     /**< Packet is a retry */
984        LT_BITFIELD32      more_frag:1; /**< Packet has more fragments */
985        LT_BITFIELD32      from_ds:1;   /**< Packet from Distribution Service */
986        LT_BITFIELD32      to_ds:1;     /**< Packet to Distribution Service */
987#endif
988       
989        uint16_t     duration;  /**< Duration value for NAV calculation */
990        uint8_t      mac1[6];   /**< MAC Address 1 */
991        uint8_t      mac2[6];   /**< MAC Address 2 */
992        uint8_t      mac3[6];   /**< MAC Address 3 */
993        uint16_t     SeqCtl;    /**< Sequence Control */       
994        uint8_t      mac4[6];   /**< MAC Address 4 */
995} PACKED libtrace_80211_t;
996
997/** The Radiotap header pre-amble
998 *
999 * All Radiotap headers start with this pre-amble, followed by the fields
1000 * specified in the it_present bitmask. If bit 31 of it_present is set, then
1001 * another bitmask follows.
1002 * @note All of the radiotap data fields are in little-endian byte-order.
1003 */
1004typedef struct libtrace_radiotap_t {
1005    uint8_t     it_version; /**< Radiotap version */
1006    uint8_t     it_pad; /**< Padding for natural alignment */
1007    uint16_t    it_len; /**< Length in bytes of the entire Radiotap header */
1008    uint32_t    it_present; /**< Which Radiotap fields are present */
1009} PACKED libtrace_radiotap_t;
1010
1011/** OSPF header */
1012typedef struct libtrace_ospf_v2_t
1013{
1014        uint8_t ospf_v;         /**< OSPF Version, should be 2 */
1015        uint8_t type;           /**< OSPF Packet Type */
1016        uint16_t ospf_len;      /**< Packet length, including OSPF header */
1017        struct in_addr router;  /**< Router ID of the packet source */
1018        struct in_addr area;    /**< Area the packet belongs to */
1019        uint16_t sum;           /**< Checksum */
1020        uint16_t au_type;       /**< Authentication procedure */
1021        uint16_t zero;          /**< Always zero */
1022        uint8_t au_key_id;      /**< Authentication Key ID */
1023        uint8_t au_data_len;    /**< Authentication Data Length */
1024        uint32_t au_seq_num;    /**< Cryptographic Sequence Number */
1025} PACKED libtrace_ospf_v2_t;
1026
1027/** Options Field present in some OSPFv2 packets */
1028typedef struct libtrace_ospf_options_t {
1029#if __BYTE_ORDER == __LITTLE_ENDIAN
1030        LT_BITFIELD8 unused1:1;
1031        LT_BITFIELD8 e_bit:1;
1032        LT_BITFIELD8 mc_bit:1;
1033        LT_BITFIELD8 np_bit:1;
1034        LT_BITFIELD8 ea_bit:1;
1035        LT_BITFIELD8 dc_bit:1;
1036        LT_BITFIELD8 unused2:2;
1037#elif __BYTE_ORDER == __BIG_ENDIAN
1038        LT_BITFIELD8 unused2:2;
1039        LT_BITFIELD8 dc_bit:1;
1040        LT_BITFIELD8 ea_bit:1;
1041        LT_BITFIELD8 np_bit:1;
1042        LT_BITFIELD8 mc_bit:1;
1043        LT_BITFIELD8 e_bit:1;
1044        LT_BITFIELD8 unused1:1;
1045#endif
1046} PACKED libtrace_ospf_options_t;
1047
1048/** LSA Header for OSPFv2 */
1049typedef struct libtrace_ospf_lsa_v2_t
1050{
1051        uint16_t age;           /**< Time in seconds since LSA originated */
1052        libtrace_ospf_options_t lsa_options;    /**< Options */
1053        uint8_t lsa_type;       /**< LSA type */
1054        struct in_addr ls_id;   /**< Link State ID */
1055        struct in_addr adv_router; /**< Router that originated this LSA */
1056        uint32_t seq;           /**< LS sequence number */
1057        uint16_t checksum;      /**< Checksum */
1058        uint16_t length;        /**< Length of the LSA including LSA header */
1059} PACKED libtrace_ospf_lsa_v2_t;
1060
1061/** OSPFv2 Hello Packet */
1062typedef struct libtrace_ospf_hello_v2_t
1063{
1064        struct in_addr mask;    /**< Network mask for this interface */
1065        uint16_t interval;      /**< Interval between Hello packets (secs) */
1066        libtrace_ospf_options_t hello_options;  /**< Options */
1067        uint8_t priority;       /**< Router Priority */
1068        uint32_t deadint;       /**< Interval before declaring a router down */
1069        struct in_addr designated;      /**< Designated router for the network */
1070        struct in_addr backup;  /**< Backup designated router */
1071
1072        /** Neighbors follow from here, but there can be anywhere from 1 to N
1073         * neighbors so I can't include that here */
1074} PACKED libtrace_ospf_hello_v2_t;
1075
1076/** OSPFv2 Database Description packet */
1077typedef struct libtrace_ospf_db_desc_v2_t
1078{
1079        uint16_t mtu;           /**< Interface MTU */
1080        libtrace_ospf_options_t db_desc_options;        /**< Options */
1081#if __BYTE_ORDER == __LITTLE_ENDIAN
1082        LT_BITFIELD8 db_desc_ms:1;      /**< If set, this router is the master */
1083        LT_BITFIELD8 db_desc_m:1;       /**< If set, more packets to follow */
1084        LT_BITFIELD8 db_desc_i:1;       /**< If set, this is the first packet in sequence */
1085        LT_BITFIELD8 zero:5;
1086#elif __BYTE_ORDER == __BIG_ENDIAN
1087        LT_BITFIELD8 zero:5;
1088        LT_BITFIELD8 db_desc_i:1;       /**< If set, this is the first packet in sequence */
1089        LT_BITFIELD8 db_desc_m:1;       /**< If set, more packets to follow */
1090        LT_BITFIELD8 db_desc_ms:1;      /**< If set, this router is the master */
1091#endif
1092        uint32_t seq;           /**< Sequence number for DD packets */
1093} PACKED libtrace_ospf_db_desc_v2_t;
1094
1095/** OSPF Link State Request Packet */
1096typedef struct libtrace_ospf_ls_req_t
1097{
1098        uint32_t ls_type;       /**< Link State Type */
1099        uint32_t ls_id;         /**< Link State Id */
1100        uint32_t advertising_router;    /**< Advertising Router */
1101} PACKED libtrace_ospf_ls_req_t;
1102
1103/** OSPF Link State Update Packet */
1104typedef struct libtrace_ospf_ls_update_t
1105{
1106        uint32_t ls_num_adv;    /**< Number of LSAs in this packet */
1107
1108        /* Followed by LSAs, use API functions to access these */
1109} PACKED libtrace_ospf_ls_update_t;
1110
1111/** OSPFv2 AS External LSA Body */
1112typedef struct libtrace_ospf_as_external_lsa_t
1113{
1114        struct in_addr netmask; /**< Netmask for the destination */
1115#if __BYTE_ORDER == __LITTLE_ENDIAN
1116        LT_BITFIELD8 tos:7;
1117        LT_BITFIELD8 e:1;       /**< If set, metric is Type 2. Else, Type 1 */
1118#elif __BYTE_ORDER == __BIG_ENDIAN
1119        LT_BITFIELD8 e:1;       /**< If set, metric is Type 2. Else, Type 1 */
1120        LT_BITFIELD8 tos:7;
1121#endif
1122        uint8_t metric_a;       /**< Byte 1 of the Metric field */
1123        uint8_t metric_b;       /**< Byte 2 of the Metric field */
1124        uint8_t metric_c;       /**< Byte 3 of the Metric field */
1125        struct in_addr forwarding;      /**< Forwarding address */
1126        uint32_t external_tag;          /**< External Route Tag */
1127} PACKED libtrace_ospf_as_external_lsa_v2_t;
1128
1129/** OSPFv2 Summary LSA Body */
1130typedef struct libtrace_ospf_summary_lsa
1131{
1132        struct in_addr netmask; /**< Netmask for the destination */
1133        uint8_t zero;           /**< Always zero */
1134        uint8_t metric_a;       /**< Byte 1 of the Metric field */
1135        uint8_t metric_b;       /**< Byte 2 of the Metric field */
1136        uint8_t metric_c;       /**< Byte 3 of the Metric field */
1137       
1138} PACKED libtrace_ospf_summary_lsa_v2_t;
1139
1140/** OSPFv2 Network LSA Body */
1141typedef struct libtrace_ospf_network_lsa_t
1142{
1143        struct in_addr netmask; /**< Netmask for the network */
1144        /* Followed by IDs of attached routers */
1145} PACKED libtrace_ospf_network_lsa_v2_t;
1146
1147/** OSPFv2 Router Link structure */
1148typedef struct libtrace_ospf_link_t
1149{
1150        struct in_addr link_id;         /**< Object that link connects to */
1151        struct in_addr link_data;       /**< Link Data field */
1152        uint8_t type;                   /**< Link Type */
1153        uint8_t num_tos;                /**< Number of TOS metrics */
1154        uint16_t tos_metric;            /**< Cost of router link */
1155} PACKED libtrace_ospf_link_v2_t;
1156
1157/** OSPFv2 Router LSA */
1158typedef struct libtrace_ospf_router_lsa_t
1159{
1160#if __BYTE_ORDER == __LITTLE_ENDIAN
1161        LT_BITFIELD8 b:1;       /**< Area Border Router Flag */
1162        LT_BITFIELD8 e:1;       /**< External Router Flag */
1163        LT_BITFIELD8 v:1;       /**< Virtual Endpoint Flag */
1164        LT_BITFIELD8 zero:5;
1165#elif __BYTE_ORDER == __BIG_ENDIAN
1166        LT_BITFIELD8 zero:5;
1167        LT_BITFIELD8 v:1;       /**< Virtual Endpoint Flag */
1168        LT_BITFIELD8 e:1;       /**< External Router Flag */
1169        LT_BITFIELD8 b:1;       /**< Area Border Router Flag */
1170#endif
1171        uint8_t zero2;          /**< Always zero */
1172        uint16_t num_links;     /**< Number of links in LSA */
1173} PACKED libtrace_ospf_router_lsa_v2_t;
1174
1175/** OSPF message types */
1176typedef enum {
1177        TRACE_OSPF_HELLO = 1,           /**< OSPF Hello */
1178        TRACE_OSPF_DATADESC = 2,        /**< OSPF Database Description */
1179        TRACE_OSPF_LSREQ = 3,           /**< OSPF Link State Request */
1180        TRACE_OSPF_LSUPDATE = 4,        /**< OSPF Link State Update */
1181        TRACE_OSPF_LSACK = 5            /**< OSPF Link State Acknowledgement */
1182} libtrace_ospf_types_t;
1183
1184/** OSPF link state acknowledgement types */
1185typedef enum {
1186        TRACE_OSPF_LS_ROUTER = 1,       /**< OSPF Router LSA */
1187        TRACE_OSPF_LS_NETWORK = 2,      /**< OSPF Network LSA */
1188        TRACE_OSPF_LS_SUMMARY = 3,      /**< OSPF Summary LSA */
1189        TRACE_OSPF_LS_ASBR_SUMMARY = 4, /**< OSPF Summary LSA (ASBR) */
1190        TRACE_OSPF_LS_EXTERNAL = 5      /**< OSPF AS External LSA */
1191} libtrace_ospf_ls_types_t;
1192
1193/** A local definition of an SLL header */
1194typedef struct libtrace_sll_header_t {
1195        uint16_t pkttype;               /**< Packet type */
1196        uint16_t hatype;                /**< Link-layer address type */
1197        uint16_t halen;                 /**< Link-layer address length */
1198        unsigned char addr[8];          /**< Link-layer address */
1199        uint16_t protocol;              /**< Protocol */
1200} libtrace_sll_header_t;
1201
1202
1203/* SLL packet types */
1204
1205/** Packet was addressed for the local host */
1206#define TRACE_SLL_HOST          0
1207/** Packet was addressed for a broadcast address */
1208#define TRACE_SLL_BROADCAST     1
1209/** Packet was addressed for a multicast address */
1210#define TRACE_SLL_MULTICAST     2
1211/** Packet was addressed for another host but was captured by a promiscuous
1212 * device */
1213#define TRACE_SLL_OTHERHOST     3
1214/** Packet originated from the local host */
1215#define TRACE_SLL_OUTGOING      4
1216
1217
1218#ifdef WIN32
1219#pragma pack(pop)
1220#endif
1221
1222
1223/*@}*/
1224
1225/** Prints help information for libtrace
1226 *
1227 * Function prints out some basic help information regarding libtrace,
1228 * and then prints out the help() function registered with each input module
1229 */
1230DLLEXPORT void trace_help(void);
1231
1232/** Causes a libtrace reader to stop blocking whilst waiting on new packets
1233 * and immediately return EOF.
1234 *
1235 * This function is useful if you are handling signals within your libtrace
1236 * program. If a live source is not receiving any packets (or they are being
1237 * filtered), a call to trace_read_packet will result in an infinite loop as
1238 * it will block until a packet is received. Normally, a SIGINT would cause the
1239 * program to end and thus break the loop, but if you are handling the signal
1240 * yourself then that signal will never reach libtrace.
1241 *
1242 * Instead this function sets a global variable within libtrace that will
1243 * cause a blocking live capture to break on the next internal timeout,
1244 * allowing control to be returned to the user and their own signal handling
1245 * to kick in.
1246 */
1247DLLEXPORT void trace_interrupt(void);
1248
1249/** @name Trace management
1250 * These members deal with creating, configuring, starting, pausing and
1251 * cleaning up a trace object
1252 *@{
1253 */
1254
1255/** Takes a uri and splits it into a format and uridata component.
1256 * @param uri           The uri to be parsed
1257 * @param [out] format  A pointer that will be updated to point to an allocated
1258 *                      string holding the format component of the URI
1259 * @return NULL if an error occurred, otherwise return a pointer to the uridata
1260 * component
1261 *
1262 * @note The format component is strdup'd by this function, so be sure to free
1263 * it when you are done with the split URI. Similarly, do not pass a pointer
1264 * to an allocated string into this function as the 'format' parameter, as
1265 * that memory will be leaked and replaced with the strdup'd format.
1266 */
1267DLLEXPORT const char *trace_parse_uri(const char *uri, char **format);
1268
1269/** Create an input trace from a URI
1270 *
1271 * @param uri A valid libtrace URI to be opened
1272 * @return An opaque pointer to a libtrace_t
1273 *
1274 * Some valid URI's are:
1275 *  - erf:/path/to/erf/file
1276 *  - erf:-  (stdin)
1277 *  - dag:/dev/dagcard
1278 *  - pcapint:pcapinterface                (eg: pcap:eth0)
1279 *  - pcap:/path/to/pcap/file
1280 *  - pcap:-
1281 *  - rt:hostname
1282 *  - rt:hostname:port
1283 *
1284 *  If an error occurred when attempting to open the trace file, a
1285 *  trace is still returned so trace_is_err() should be called to find out
1286 *  if an error occurred. The trace is created in the configuration state, you
1287 *  must call trace_start before attempting to read packets from the trace.
1288 */
1289DLLEXPORT libtrace_t *trace_create(const char *uri);
1290
1291/** Creates a "dummy" trace file that has only the format type set.
1292 *
1293 * @param uri A valid (but fake) URI indicating the format of the dummy trace that is to be created.
1294 * @return An opaque pointer to a (sparsely initialised) libtrace_t
1295 *
1296 * Only the format portion of the uri parameter matters - the 'file' being
1297 * opened does not have to exist.
1298 *
1299 * @note IMPORTANT: Do not attempt to call trace_read_packet or other such
1300 * functions with the dummy trace. Its intended purpose is to provide access
1301 * to the format functions where the original trace may no longer exist or is
1302 * not the correct format, e.g. reading ERF packets from an RT input.
1303 */
1304DLLEXPORT libtrace_t *trace_create_dead(const char *uri);
1305
1306/** Creates a trace output file from a URI.
1307 *
1308 * @param uri The uri string describing the output format and destination
1309 * @return An opaque pointer to a libtrace_output_t
1310 *
1311 * Valid URIs include:
1312 *  - erf:/path/to/erf/file
1313 *  - pcap:/path/to/pcap/file
1314 *
1315 *  If an error occurred when attempting to open the output trace, a trace is
1316 *  still returned but trace_errno will be set. Use trace_is_err_out() and
1317 *  trace_perror_output() to get more information.
1318 */
1319DLLEXPORT libtrace_out_t *trace_create_output(const char *uri);
1320
1321/** Start an input trace
1322 * @param libtrace      The trace to start
1323 * @return 0 on success, -1 on failure
1324 *
1325 * This does the actual work of starting the input trace and applying
1326 * all the config options.  This may fail, returning -1. The libtrace error
1327 * handling functions can be used to get more information about what
1328 * specifically went wrong.
1329 */
1330DLLEXPORT int trace_start(libtrace_t *libtrace);
1331
1332/** Pauses an input trace
1333 * @param libtrace      The trace to pause
1334 * @return 0 on success, -1 on failure
1335 *
1336 * This stops an input trace that is in progress and returns you to the
1337 * configuration state.  Any packets that arrive on a live capture after
1338 * trace_pause() has been called will be discarded.  To resume the trace, call
1339 * trace_start().
1340 */
1341DLLEXPORT int trace_pause(libtrace_t *libtrace);
1342
1343/** Start an output trace
1344 * @param libtrace      The trace to start
1345 * @return 0 on success, -1 on failure
1346 *
1347 * This does the actual work with starting a trace capable of writing packets. 
1348 * This generally creates the output file.
1349 */
1350DLLEXPORT int trace_start_output(libtrace_out_t *libtrace);
1351
1352/** Valid configuration options for input traces */
1353typedef enum {
1354        /** Maximum number of bytes to be captured for any given packet */
1355        TRACE_OPTION_SNAPLEN,   
1356
1357        /** If enabled, places a live capture interface into promiscuous mode */
1358        TRACE_OPTION_PROMISC,   
1359
1360        /** Apply this filter to all packets read from this trace */
1361        TRACE_OPTION_FILTER,   
1362
1363        /** Defines the frequency of meta-data reporting, e.g. DUCK packets */
1364        TRACE_OPTION_META_FREQ,
1365
1366        /** If enabled, the libtrace event API will ignore time gaps between
1367         * packets when reading from a trace file */
1368        TRACE_OPTION_EVENT_REALTIME,
1369
1370        /** The hasher function for a parallel libtrace. It is recommended to
1371         * access this option via trace_set_hasher(). */
1372        TRACE_OPTION_HASHER,
1373
1374        /** Speed up trace file replays (via trace_event()) by this factor */
1375        TRACE_OPTION_REPLAY_SPEEDUP,
1376
1377        /** Always assume ERF framing length is the given value, rather than
1378         *  trying to calculate it from the packet type. */
1379        TRACE_OPTION_CONSTANT_ERF_FRAMING,
1380} trace_option_t;
1381
1382/** Sets an input config option
1383 * @param libtrace      The trace object to apply the option to
1384 * @param option        The option to set
1385 * @param value         The value to set the option to
1386 * @return -1 if option configuration failed, 0 otherwise
1387 *
1388 * This should be called after trace_create(), and before trace_start()
1389 *
1390 * @note Please consider using the newer trace_set_X() functions to access
1391 * this function.
1392 */
1393DLLEXPORT int trace_config(libtrace_t *libtrace,
1394                trace_option_t option,
1395                void *value);
1396
1397/** Maximum number of bytes to be captured for any given packet
1398 *
1399 * @param libtrace The trace object to apply the option to
1400 * @param snaplen The snap length to set
1401 * @return -1 if option configuration failed, 0 otherwise
1402 */
1403DLLEXPORT int trace_set_snaplen(libtrace_t *trace, int snaplen);
1404
1405/** If enabled, places a live capture interface into promiscuous mode
1406 *
1407 * @param libtrace The trace object to apply the option to
1408 * @param promisc
1409 * @return -1 if option configuration failed, 0 otherwise
1410 */
1411DLLEXPORT int trace_set_promisc(libtrace_t *trace, bool promisc);
1412
1413/** Apply this filter to all packets read from this trace
1414 *
1415 * @param libtrace The trace object to apply the option to
1416 * @param filter The filter to apply
1417 * @return -1 if option configuration failed, 0 otherwise
1418 */
1419DLLEXPORT int trace_set_filter(libtrace_t *trace, libtrace_filter_t *filter);
1420
1421/** Defines the frequency of meta-data reporting, e.g. DUCK packets
1422 *
1423 * @param libtrace The trace object to apply the option to
1424 * @param freq The meta data frequency
1425 * @return -1 if option configuration failed, 0 otherwise
1426 */
1427DLLEXPORT int trace_set_meta_freq(libtrace_t *trace, int freq);
1428
1429/** If enabled, the libtrace event API will ignore time gaps between
1430 * packets when reading from a trace file.
1431 *
1432 * @param libtrace The trace object to apply the option to
1433 * @param realtime True ignores gaps
1434 * @return -1 if option configuration failed, 0 otherwise
1435 */
1436DLLEXPORT int trace_set_event_realtime(libtrace_t *trace, bool realtime);
1437
1438/** Valid compression types
1439 * Note, this must be kept in sync with WANDIO_COMPRESS_* numbers in wandio.h
1440 */
1441typedef enum {
1442        TRACE_OPTION_COMPRESSTYPE_NONE = 0, /**< No compression */
1443        TRACE_OPTION_COMPRESSTYPE_ZLIB = 1, /**< GZip Compression */
1444        TRACE_OPTION_COMPRESSTYPE_BZ2  = 2, /**< BZip2 Compression */
1445        TRACE_OPTION_COMPRESSTYPE_LZO  = 3,  /**< LZO Compression */
1446        TRACE_OPTION_COMPRESSTYPE_LZMA  = 4,  /**< LZO Compression */
1447        TRACE_OPTION_COMPRESSTYPE_LAST
1448} trace_option_compresstype_t;
1449
1450/** Valid configuration options for output traces */
1451typedef enum {
1452        /** File flags to use when opening an output file, e.g. O_APPEND */
1453        TRACE_OPTION_OUTPUT_FILEFLAGS,
1454        /** Compression level: 0 = no compression, 1 = faster compression,
1455         * 9 = better compression */
1456        TRACE_OPTION_OUTPUT_COMPRESS,
1457        /** Compression type, see trace_option_compresstype_t */
1458        TRACE_OPTION_OUTPUT_COMPRESSTYPE
1459} trace_option_output_t;
1460
1461/* To add a new stat field update this list, and the relevant places in
1462 * libtrace_stat_t structure.
1463 */
1464/** An X Macro set for libtrace stat fields */
1465#define LIBTRACE_STAT_FIELDS \
1466        X(accepted) \
1467        X(filtered) \
1468        X(received) \
1469        X(dropped) \
1470        X(captured) \
1471        X(missing) \
1472        X(errors)
1473
1474/**
1475 * Statistic counters are cumulative from the time the trace is started.
1476 * Trace pause will reset the counters, to zero.
1477 * Always check \a{field}_valid is set before attempting to read the stored
1478 * value.
1479 *
1480 * @note Always allocate this structure using trace_create_statistics().
1481 *       This allows us to extend the structure in the future.
1482 */
1483typedef struct libtrace_stat_t {
1484#define X(name) LT_BITFIELD64 name ##_valid : 1;
1485        LIBTRACE_STAT_FIELDS
1486#undef X
1487        /* We use the remaining space as magic to ensure the structure
1488         * was alloc'd by us. We can easily decrease the no. bits without
1489         * problems as long as we update any asserts as needed */
1490        LT_BITFIELD64 reserved1: 25; /**< Bits reserved for future fields */
1491        LT_BITFIELD64 reserved2: 24; /**< Bits reserved for future fields */
1492        LT_BITFIELD64 magic: 8; /**< A number stored against the format to
1493                                  ensure the struct was allocated correctly */
1494
1495        /* These must all be uint64_t's, match this order with the X macro */
1496        /** The number of packets that have been read from the input trace
1497         * using trace_read_packet(). In the parallel framework this may include
1498         * some packets waiting in a batch yet to be seen by the user's
1499         * application.
1500         *
1501         * This does not include filtered packets because these do not make it
1502         * to trace_read_packet().
1503         *
1504         * @note This field replaces trace_get_accepted_packets()
1505         */
1506        uint64_t accepted;
1507
1508        /** The number of packets that were captured, but discarded for not
1509         * matching a provided filter.
1510         *
1511         * @note This field replaces trace_get_filtered_packets()
1512         */
1513        uint64_t filtered;
1514
1515        /** The total number of good packets which have been received. Including
1516         * those which are dropped and filtered. This does not include errors.
1517         *
1518         * @note This may include a small number of buffered packets
1519         *       not yet included in accepted.
1520         *
1521         * @note This field replaces trace_get_received_packets()
1522         */
1523        uint64_t received;
1524
1525        /** The number of packets that have been dropped on an input trace
1526         * due to lack of buffer space on the capturing device. This does not
1527         * included errored packets which are dropped directly by the card.
1528         *
1529         * @note This field replaces trace_get_dropped_packets()
1530         */
1531        uint64_t dropped;
1532
1533        /** The number of received packets that have not been dropped. This
1534         * includes filtered packets.
1535         *
1536         * This is equivalent to received-dropped.
1537         *
1538         * @note This may include a small number of buffered packets
1539         *       not yet included in accepted.
1540         */
1541        uint64_t captured;
1542
1543        /** The number of packets (or aggregated records) that have been
1544         *  lost between the original capture device and the current input
1545         *  trace.
1546         *
1547         *  @note Only relevant for input formats that use a network to
1548         *  transfer live captured packets from one host to another (e.g.
1549         *  nDAG).
1550         */
1551        uint64_t missing;
1552
1553        /** The number of packets that have been discarded by the network card
1554         * because they are invalid. That includes FCS mismatches, incorrect
1555         * packet lengths etc.
1556         */
1557        uint64_t errors;
1558} libtrace_stat_t;
1559
1560ct_assert(offsetof(libtrace_stat_t, accepted) == 8);
1561
1562/** Sets an output config option
1563 *
1564 * @param libtrace      The output trace object to apply the option to
1565 * @param option        The option to set
1566 * @param value         The value to set the option to
1567 * @return -1 if option configuration failed, 0 otherwise
1568 * This should be called after trace_create_output, and before
1569 * trace_start_output
1570 */
1571DLLEXPORT int trace_config_output(libtrace_out_t *libtrace,
1572                trace_option_output_t option,
1573                void *value
1574                );
1575
1576/** Close an input trace, freeing up any resources it may have been using
1577 *
1578 * @param trace         The input trace to be destroyed
1579 *
1580 */
1581DLLEXPORT void trace_destroy(libtrace_t *trace);
1582
1583/** Close a dummy trace file, freeing up any resources it may have been using
1584 * @param trace         The dummy trace to be destroyed
1585 */
1586DLLEXPORT void trace_destroy_dead(libtrace_t *trace);
1587
1588/** Close an output trace, freeing up any resources it may have been using
1589 * @param trace         The output trace to be destroyed
1590 */
1591DLLEXPORT void trace_destroy_output(libtrace_out_t *trace);
1592
1593/** Flush an output trace, forcing any buffered packets to be written
1594 * @param libtrace      The output trace to be flushed
1595 */
1596DLLEXPORT int trace_flush_output(libtrace_out_t *libtrace);
1597
1598/** Check (and clear) the current error state of an input trace
1599 * @param trace         The input trace to check the error state on
1600 * @return The current error status and message
1601 *
1602 * This reads and returns the current error state and sets the current error
1603 * to "no error".
1604 */
1605DLLEXPORT libtrace_err_t trace_get_err(libtrace_t *trace);
1606
1607/** Indicate if there has been an error on an input trace
1608 * @param trace         The input trace to check the error state on
1609 * @return true if an error has occurred, false otherwise
1610 *
1611 * @note This does not clear the error status, and only returns true or false.
1612 */
1613DLLEXPORT bool trace_is_err(libtrace_t *trace);
1614
1615/** Outputs the error message for an input trace to stderr and clear the error
1616 * status.
1617 * @param trace         The input trace with the error to output
1618 * @param msg           The message to prepend to the error
1619 *
1620 * This function does clear the error status.
1621 */
1622DLLEXPORT void trace_perror(libtrace_t *trace, const char *msg,...) PRINTF(2,3);
1623
1624/** Checks (and clears) the current error state for an output trace
1625 * @param trace         The output trace to check the error state on
1626 * @return The current error status and message
1627 *
1628 * This reads and returns the current error state and sets the current error
1629 * to "no error".
1630 */
1631DLLEXPORT libtrace_err_t trace_get_err_output(libtrace_out_t *trace);
1632
1633/** Indicates if there is an error on an output trace
1634 * @param trace         The output trace to check the error state on
1635 * @return true if an error has occurred, false otherwise.
1636 *
1637 * This does not clear the error status, and only returns true or false.
1638 */
1639DLLEXPORT bool trace_is_err_output(libtrace_out_t *trace);
1640
1641/** Outputs the error message for an output trace to stderr and clear the error
1642 * status.
1643 * @param trace         The output trace with the error to output
1644 * @param msg           The message to prepend to the error
1645 * This function does clear the error status.
1646 */
1647DLLEXPORT void trace_perror_output(libtrace_out_t *trace, const char *msg,...)
1648        PRINTF(2,3);
1649
1650/** Returns the number of packets observed on an input trace.
1651 * Includes the number of packets counted as early as possible, before
1652 * filtering, and includes dropped packets.
1653 *
1654 * @param trace         The input trace to examine
1655 * @returns The number of packets seen at the capture point before filtering.
1656 *
1657 * If the number is not known, this function will return UINT64_MAX
1658 *
1659 * @deprecated This function is deprecated: Use trace_get_statistics(), this
1660 *             allows all statistic counters to be read in an atomic manner.
1661 */
1662DLLEXPORT DEPRECATED
1663uint64_t trace_get_received_packets(libtrace_t *trace);
1664
1665/** Returns the number of packets that were captured, but discarded for not
1666 * matching a provided filter.
1667 *
1668 * @param trace         The input trace to examine
1669 * @returns The number of packets that were successfully captured, but filtered
1670 *
1671 * If the number is not known, this function will return UINT64_MAX
1672 *
1673 * @deprecated This function is deprecated: Use trace_get_statistics(), this
1674 *             allows all statistic counters to be read in an atomic manner.
1675 */
1676DLLEXPORT DEPRECATED
1677uint64_t trace_get_filtered_packets(libtrace_t *trace);
1678
1679/** Returns the number of packets that have been dropped on an input trace due
1680 * to lack of buffer space on the capturing device.
1681 *
1682 * @param trace         The input trace to examine
1683 * @returns The number of packets captured, but dropped due to buffer overruns
1684 *
1685 * If the number is not known, this function will return UINT64_MAX
1686 *
1687 * @deprecated This function is deprecated: Use trace_get_statistics(), this
1688 *             allows all statistic counters to be read in an atomic manner.
1689 */
1690DLLEXPORT DEPRECATED
1691uint64_t trace_get_dropped_packets(libtrace_t *trace);
1692
1693/** Returns the number of packets that have been read from the input trace using
1694 * trace_read_packet().
1695 *
1696 * @param trace         The input trace to examine
1697 * @returns The number of packets that have been read by the libtrace user.
1698 *
1699 * If the number is not known, this function will return UINT64_MAX
1700 *
1701 * @deprecated This function is deprecated: Use trace_get_statistics(), this
1702 *             allows all statistic counters to be read in an atomic manner.
1703 */
1704DLLEXPORT DEPRECATED
1705uint64_t trace_get_accepted_packets(libtrace_t *trace);
1706
1707/**
1708 * Returns statistic counters for a trace, for a parallel trace this is a
1709 * combined total.
1710 * Where possible these are retrieved atomically, however this behaviour depends
1711 * on the underlying trace format.
1712 *
1713 * @param trace The input trace to examine.
1714 * @param stats Optional, Filled upon return with statistics about the trace,
1715 *              check the flags included to see if a given statistic is valid.
1716 *              If NULL a statistic structure owned by libtrace is returned, this
1717 *              should not be free'd and will become invalid if the trace is
1718 *              destroyed.
1719 *
1720 * @return A pointer to the statistics structure.
1721 * @note Use trace_create_stat() to create the stats object, this way future
1722 *       versions of libtrace can add to the structure without breaking existing
1723 *       code.
1724 */
1725DLLEXPORT
1726libtrace_stat_t *trace_get_statistics(libtrace_t *trace, libtrace_stat_t *stats);
1727
1728
1729/**
1730 * Returns statistic counters for a single thread of a trace.
1731 * Where possible these are retrieved atomically, however this behaviour depends
1732 * on the underlying trace format.
1733 *
1734 * @param trace The input trace to examine.
1735 * @param t An optional thread to received stats for or NULL to retrieve stats
1736 *          for the current thread
1737 * @param stats Filled upon return with statistics about the trace, check the
1738 *              flags included to see if a given statistic is valid.
1739 *
1740 * @note Use trace_create_stat() to create the stats object, this way future
1741 *       versions of libtrace can add to the structure without breaking existing
1742 *       code.
1743 */
1744DLLEXPORT
1745void trace_get_thread_statistics(libtrace_t *trace, libtrace_thread_t *t,
1746                                 libtrace_stat_t *stats);
1747
1748/**
1749 * Creates and returns a zeroed libtrace_stat_t structure.
1750 *
1751 * This allows us to add extra fields increasing the size of the structure
1752 * without breaking existing libtrace applications.
1753 *
1754 * This structure should be free'd using free().
1755 *
1756 * @return A valid pointer to a libtrace_stat_t struct otherwise NULL if
1757 *         memory was not available.
1758 */
1759DLLEXPORT libtrace_stat_t* trace_create_statistics(void);
1760
1761/**
1762 * Clear all fields of given statistic.
1763 * This api doesn't verify the magic field unlike other stat apis.
1764 *
1765 * @param s The statistic structure to clear
1766 */
1767DLLEXPORT
1768void trace_clear_statistics(libtrace_stat_t *s);
1769
1770/**
1771 * Performs the operation c=a-b accounting for valid fields.
1772 * c is allowed to be a or b.
1773 *
1774 * @param a The minuend
1775 * @param b The subtrahend
1776 * @param c The resulting difference
1777 */
1778DLLEXPORT
1779void trace_subtract_statistics(const libtrace_stat_t *a,
1780                               const libtrace_stat_t *b, libtrace_stat_t *c);
1781
1782/**
1783 * Performs operation c=a+b accounting for valid fields.
1784 * c is allowed to be a or b.
1785 *
1786 * @param a The first operand
1787 * @param b The second operand
1788 * @param c The result
1789 */
1790DLLEXPORT
1791void trace_add_statistics(const libtrace_stat_t *a,
1792                          const libtrace_stat_t *b, libtrace_stat_t *c);
1793
1794/**
1795 * Prints all valid stats to a file stream, (which could be stdout/err).
1796 * By default the format "name: value" is used.
1797 *
1798 * @param s The statistic structure to print
1799 * @param f The output file stream
1800 * @param format An optional format string such as the default ("%s: %"PRIu64"\n")
1801 *               This is passed to fprintf and called with two arguments
1802 *               first a char* (%s) and second a uint64_t (%PRIu64).
1803 *
1804 * @return -1 if an error occurs when writing to the file stream, check errno.
1805 *         Otherwise 0.
1806 */
1807DLLEXPORT
1808int trace_print_statistics(const libtrace_stat_t *s, FILE *f,
1809                           const char *format);
1810
1811
1812/*@}*/
1813
1814/** @name Reading / Writing packets
1815 * These members deal with creating, reading and writing packets
1816 *
1817 * @{
1818 */
1819
1820/** Create a new packet object
1821 *
1822 * @return A pointer to an initialised libtrace_packet_t object, or NULL if
1823 * libtrace is unable to allocate space for a new packet.
1824 */
1825DLLEXPORT libtrace_packet_t *trace_create_packet(void);
1826
1827/** Copy a packet object
1828 * @param packet        The source packet to copy
1829 * @return A new packet which has the same content as the source packet
1830 *
1831 * @note This always involves a copy, which can be slow.  Use of this
1832 * function should be avoided where possible.
1833 *
1834 * @par The reason you would want to use this function is that a zero-copied
1835 * packet from a device will be stored using memory owned by the device which
1836 * may be a limited resource. Copying the packet will ensure that the packet
1837 * is now stored in memory owned and managed by libtrace.
1838 */
1839DLLEXPORT libtrace_packet_t *trace_copy_packet(const libtrace_packet_t *packet);
1840
1841/** Destroy a packet object
1842 * @param packet        The packet to be destroyed
1843 *
1844 */
1845DLLEXPORT void trace_destroy_packet(libtrace_packet_t *packet);
1846
1847/** Read the next packet from an input trace
1848 *
1849 * @param trace         The libtrace opaque pointer for the input trace
1850 * @param packet        The packet opaque pointer
1851 * @return 0 on EOF, negative value on error, number of bytes read when successful.
1852 *
1853 * @note The number of bytes read is usually (but not always) the same as
1854 * trace_get_framing_length()+trace_get_capture_length() depending on the
1855 * trace format.
1856 *
1857 * @note The trace must have been started with trace_start before calling
1858 * this function
1859 *
1860 * @note When reading from a live capture, this function will block until a
1861 * packet is observed on the capture interface. The libtrace event API
1862 * (e.g. trace_event()) should be used if non-blocking operation is required.
1863 */
1864DLLEXPORT int trace_read_packet(libtrace_t *trace, libtrace_packet_t *packet);
1865
1866/** Converts the data provided in buffer into a valid libtrace packet
1867 *
1868 * @param trace         An input trace of the same format as the "packet"
1869 *                      contained in the buffer
1870 * @param packet        The libtrace packet to prepare
1871 * @param buffer        A buffer containing the packet data, including the
1872 *                      capture format header
1873 * @param rt_type       The RT type for the packet that is being prepared
1874 * @param flags         Used to specify options for the preparation function,
1875 *                      e.g. who owns the packet buffer
1876 *
1877 * @return -1 if an error occurs, 0 otherwise
1878 *
1879 * Packet preparation is a tricky concept - the idea is to take the data
1880 * pointed to by 'buffer' and treat it as a packet record of the same capture
1881 * format as that used by the input trace. The provided libtrace packet then
1882 * has its internal pointers and values set to describe the packet record in
1883 * the buffer.
1884 *
1885 * The primary use of this function is to allow the RT packet reader to
1886 * easily and safely convert packets from the RT format back into the format
1887 * that they were originally captured with., essentially removing the RT
1888 * encapsulation.
1889 *
1890 * This function is now available via the exported API, as it can have some
1891 * uses outside of internal libtrace contexts. However, we strongly advise
1892 * that you avoid using this function unless you really know what you are
1893 * doing.
1894 */
1895DLLEXPORT int trace_prepare_packet(libtrace_t *trace, libtrace_packet_t *packet,
1896                void *buffer, libtrace_rt_types_t rt_type, uint32_t flags);
1897
1898/** Flags for prepare_packet functions */
1899enum {
1900        /** The buffer memory has been allocated by libtrace and should be
1901         * freed when the packet is destroyed. */
1902        TRACE_PREP_OWN_BUFFER           =1,
1903
1904        /** The buffer memory is externally-owned and must not be freed by
1905         * libtrace when the packet is destroyed. */
1906        TRACE_PREP_DO_NOT_OWN_BUFFER    =0
1907};
1908
1909
1910/** Event types
1911 * see \ref libtrace_eventobj_t and \ref trace_event
1912 */
1913typedef enum {
1914        TRACE_EVENT_IOWAIT,     /**< Wait on the given file descriptor */
1915        TRACE_EVENT_SLEEP,      /**< Sleep for the given amount of time */
1916        TRACE_EVENT_PACKET,     /**< Packet has been read from input trace */
1917        TRACE_EVENT_TERMINATE   /**< End of input trace */
1918} libtrace_event_t;
1919
1920/** Structure returned by libtrace_event explaining what the current event is */
1921typedef struct libtrace_eventobj_t {
1922        libtrace_event_t type; /**< Event type (iowait,sleep,packet) */
1923       
1924        /** If the event is IOWAIT, the file descriptor to wait on */
1925        int fd;               
1926        /** If the event is SLEEP, the amount of time to sleep for in seconds */
1927        double seconds;       
1928        /** If the event is PACKET, the value returned by trace_read_packet() */
1929        int size;
1930} libtrace_eventobj_t;
1931
1932/** Processes the next libtrace event from an input trace.
1933 * @param trace The libtrace opaque pointer for the input trace
1934 * @param packet The libtrace_packet opaque pointer to use for reading packets
1935 * @return A libtrace_event struct containing the event type and details of the event.
1936 *
1937 * Type can be:
1938 *  TRACE_EVENT_IOWAIT  Waiting on I/O on a file descriptor
1939 *  TRACE_EVENT_SLEEP   Wait a specified amount of time for the next event
1940 *  TRACE_EVENT_PACKET  Packet was read from the trace
1941 *  TRACE_EVENT_TERMINATE Trace terminated (perhaps with an error condition)
1942 */
1943DLLEXPORT libtrace_eventobj_t trace_event(libtrace_t *trace,
1944                libtrace_packet_t *packet);
1945
1946
1947/** Write one packet out to the output trace
1948 *
1949 * @param trace         The libtrace_out opaque pointer for the output trace
1950 * @param packet        The packet opaque pointer of the packet to be written
1951 * @return The number of bytes written out, if zero or negative then an error has occured.
1952 */
1953DLLEXPORT int trace_write_packet(libtrace_out_t *trace, libtrace_packet_t *packet);
1954
1955/** Gets the capture format for a given packet.
1956 * @param packet        The packet to get the capture format for.
1957 * @return The capture format of the packet
1958 *
1959 * @note Due to ability to convert packets between formats relatively easily
1960 * in Libtrace, the format of the packet right now may not be the format that
1961 * the packet was originally captured with.
1962 */
1963DLLEXPORT
1964enum base_format_t trace_get_format(struct libtrace_packet_t *packet);
1965
1966/** Construct a libtrace packet from a buffer containing the packet payload.
1967 * @param[in,out] packet        Libtrace Packet object to update with the new
1968 *                              data.
1969 * @param linktype              The linktype of the packet data.
1970 * @param[in] data              The packet data (including linklayer).
1971 * @param len                   Length of packet data provided in the buffer.
1972 *
1973 * @note The constructed packet will be in the PCAP format.
1974 *
1975 * @note To be useful, the provided buffer must start with the layer 2 header
1976 * (or a metadata header, if desired).
1977 */
1978DLLEXPORT
1979void trace_construct_packet(libtrace_packet_t *packet,
1980                libtrace_linktype_t linktype, const void *data, uint16_t len);
1981
1982/*@}*/
1983
1984/** @name Protocol decodes
1985 * These functions locate and return a pointer to various headers inside a
1986 * packet
1987 *
1988 * A packet is divided up into several "layers.":
1989 *
1990 * @li Framing header -- This is the header provided by the capture format
1991 * itself rather than anything that was sent over the network. This provides
1992 * basic details about the packet record including capture lengths, wire
1993 * lengths, timestamps, direction information and any other metadata that is
1994 * part of the capture format. 
1995 *
1996 * @li Metadata header (optional) -- A header containing metadata about a
1997 * packet that was captured, but the metadata was not transmitted over the
1998 * wire.  Some examples include RadioTap and Linux_sll headers.  This can be
1999 * retrieved by trace_get_packet_meta(), or skipped using
2000 * trace_get_payload_from_meta(). There may be multiple "metadata" headers on
2001 * a packet.
2002 *
2003 * @li Layer 2/Link layer/Datalink header -- This can be retrieved by
2004 * trace_get_layer2(), or skipped using trace_get_payload_from_layer2().
2005 *
2006 * @li Layer 3/IP/IPv6 -- This can be retrieved by trace_get_layer3().  As a
2007 * convenience trace_get_ip()/trace_get_ip6() can be used to find an IPv4/IPv6
2008 * header.
2009 *
2010 * @li Layer 5/transport -- These are protocols carried in IPv4/IPv6 frames.
2011 * These can be retrieved using trace_get_transport().
2012 *
2013 * @{
2014 */
2015
2016
2017/** Gets a pointer to the first byte of the packet as it was captured and
2018 * returns its corresponding linktype and capture length.
2019 *
2020 * Use this function instead of the deprecated trace_get_link().
2021 *
2022 * @param packet The packet to get the buffer from
2023 * @param[out] linktype The linktype of the returned pointer
2024 * @param[out] remaining The capture length (the number of captured bytes from
2025 * the returned pointer)
2026 * @return A pointer to the first byte of the packet
2027 */
2028DLLEXPORT void *trace_get_packet_buffer(const libtrace_packet_t *packet,
2029                libtrace_linktype_t *linktype, uint32_t *remaining);
2030
2031/** Get a pointer to the link layer for a given packet
2032 * @param packet        The packet to get the link layer for
2033 *
2034 * @return A pointer to the link layer, or NULL if there is no link layer
2035 *
2036 * @deprecated This function is deprecated: Use trace_get_packet_buffer() or
2037 * one of the trace_get_layer*() functions instead.
2038 * @note You should call trace_get_link_type to find out what type of link
2039 * layer has been returned to you.
2040 */
2041DLLEXPORT SIMPLE_FUNCTION DEPRECATED
2042void *trace_get_link(const libtrace_packet_t *packet);
2043
2044/** Strips layer 2.5 headers from a given packet.
2045 * @param packet        The packet to strip headers from.
2046 *
2047 * @return The packet with the requested headers removed (if they were
2048 * present).
2049 *
2050 * This function is intended for removing those pesky layer 2.5 headers
2051 * that are not supported by other packet analysis applications, e.g. VLAN
2052 * and MPLS headers. If successful, the resulting packet will be a simple
2053 * Ethernet-IP-Transport packet that just about anything should be able to
2054 * parse without difficulty.
2055 *
2056 * If this function encounters a layer 2 or 2.5 header that it does not
2057 * support, stripping will cease and the packet returning will be stripped
2058 * up to but not including the unsupported header.
2059 *
2060 * New in libtrace 4.0.0
2061 *
2062 * @note This function only supports stripping headers from Ethernet packets
2063 * for now. Passing in packets of other link types will simply result in
2064 * the original packet being returned unmodified.
2065 *
2066 */
2067DLLEXPORT libtrace_packet_t *trace_strip_packet(libtrace_packet_t *packet);
2068
2069/** Get a pointer to the IPv4 header (if any) for a given packet
2070 * @param packet        The packet to get the IPv4 header for
2071 *
2072 * @return A pointer to the IPv4 header, or NULL if there is no IPv4 header
2073 *
2074 * If a partial IP header is present, i.e. the packet has been truncated before
2075 * the end of the IP header, this function will return NULL.
2076 *
2077 * You should consider using \ref trace_get_layer3 instead of this function.
2078 */
2079DLLEXPORT SIMPLE_FUNCTION
2080libtrace_ip_t *trace_get_ip(libtrace_packet_t *packet);
2081
2082/** get a pointer to the IPv6 header (if any)
2083 * @param packet        The packet to get the IPv6 header for
2084 *
2085 * @return A pointer to the IPv6 header, or NULL if there is no IPv6 header
2086 *
2087 * If a partial IPv6 header is present, i.e. the packet has been truncated
2088 * before the end of the IP header, this function will return NULL.
2089 *
2090 * You should consider using \ref trace_get_layer3 instead of this function.
2091 */
2092DLLEXPORT SIMPLE_FUNCTION
2093libtrace_ip6_t *trace_get_ip6(libtrace_packet_t *packet);
2094
2095/** Return a pointer to the first metadata header in a packet, if present.
2096 *
2097 * This function takes a pointer to a libtrace packet and if any metadata
2098 * headers exist, returns a pointer to the first one, along with its
2099 * corresponding linktype.
2100 *
2101 * If no metadata headers exist in the packet, NULL is returned.
2102 *
2103 * A metadata header is a header that was prepended by the capturing device,
2104 * such as a Linux SLL header, or a Radiotap wireless monitoring header.
2105 * Subsequent metadata headers may be accessed with the
2106 * trace_get_payload_from_meta(...) function.
2107 *
2108 * @param packet The libtrace packet
2109 * @param[out] linktype The linktype of the returned metadata header
2110 * @param[out] remaining The number of bytes captured after the returned
2111 * pointer.
2112 * @return A pointer to the first metadata header, or NULL if there are no
2113 * metadata headers present.
2114 *
2115 * remaining may be NULL, however linktype must be provided.
2116 */
2117DLLEXPORT void *trace_get_packet_meta(const libtrace_packet_t *packet,
2118                libtrace_linktype_t *linktype,
2119                uint32_t *remaining);
2120
2121/** Returns the payload of a metadata header.
2122 *
2123 * This function takes a pointer to the start of a metadata header (either
2124 * obtained via trace_get_packet_meta(...) or by a previous call to
2125 * trace_get_payload_from_meta(...)) along with its corresponding linktype and
2126 * returns the payload, i.e. the next header. It will also update the linktype
2127 * parameter to indicate the type of payload.
2128 * 
2129 * If the linktype indicates that the header passed in is not a metadata
2130 * header, the function returns NULL to indicate this. The linktype remains
2131 * unchanged in this case.
2132 *
2133 * This function allows the user to iterate through metadata headers which are
2134 * sometimes present before the actual packet as it was received on the wire.
2135 * Examples of metadata headers include the Linux SLL header and the Radiotap
2136 * wireless monitoring header.
2137 *
2138 * If the metadata header passed into this function is truncated, this
2139 * function will return NULL, and remaining will be set to 0.
2140 *
2141 * If there are 0 bytes of payload following the provided metadata header, the
2142 * function will return a pointer to where the header would otherwise be and
2143 * remaining will be 0.
2144 *
2145 * Therefore, be sure to check the value of remaining after calling this
2146 * function!
2147 *
2148 * @param[in] meta A pointer to a metadata header
2149 * @param[in,out] linktype The linktype of meta (updated to indicate the
2150 * linktype of the returned header if applicable).
2151 * @param[in,out] remaining The number of bytes after the meta pointer.
2152 * @return A pointer to the payload of the metadata header. If meta is not a
2153 * pointer to a metadata header, NULL is returned and linktype remains
2154 * unchanged.
2155 *
2156 * All parameters are mandatory.
2157 */
2158DLLEXPORT void *trace_get_payload_from_meta(const void *meta,
2159                libtrace_linktype_t *linktype,
2160                uint32_t *remaining);
2161
2162
2163/** Get a pointer to the layer 2 header. Generally this is the first byte of the
2164 * packet as it was seen on the wire.
2165 *
2166 * This function takes a libtrace packet and skips over any metadata headers if
2167 * present (such as Linux SLL or Radiotap) and returns a pointer to the first
2168 * byte of the packet that was actually received by the network interface.
2169 *
2170 * @param packet The libtrace packet to find the layer 2 header for
2171 * @param[out] linktype The linktype of the returned layer 2 header
2172 * @param[out] remaining The number of bytes left in the packet after the
2173 * returned pointer.
2174 * @return A pointer to the first byte of the packet as it was seen on the
2175 * wire. If no layer 2 header is present, this function will return NULL.
2176 *
2177 * remaining may be NULL, otherwise it will be filled in by the function.
2178 */
2179DLLEXPORT void *trace_get_layer2(const libtrace_packet_t *packet,
2180                libtrace_linktype_t *linktype,
2181                uint32_t *remaining);
2182
2183/** Gets a pointer to the next header following a layer 2 header
2184 *
2185 * @param l2                    The pointer to the current layer 2 header
2186 * @param linktype              The type of the layer 2 header
2187 * @param[out] ethertype        An optional output variable of the ethernet type of the new header
2188 * @param[in,out] remaining     Updated with the number of captured bytes
2189                                remaining
2190 *
2191 * @return A pointer to the header following the provided layer 2 header, or
2192 * NULL if no subsequent header is present.
2193 *
2194 * Remaining must point to the number of bytes captured from the layer 2 header
2195 * and beyond.  It will be decremented by the number of bytes skipped to find
2196 * the payload.
2197 *
2198 * If the layer 2 header is complete but there are zero bytes of payload after
2199 * the end of the header, a pointer to where the payload would be is returned
2200 * and remaining will be set to 0.  If the layer 2 header is incomplete
2201 * (truncated), then NULL is returned and remaining will be set to 0.
2202 * Therefore, it is very important to check the value of remaining after
2203 * calling this function.
2204 *
2205 */
2206DLLEXPORT void *trace_get_payload_from_layer2(void *l2,
2207                libtrace_linktype_t linktype,
2208                uint16_t *ethertype,
2209                uint32_t *remaining);
2210
2211
2212/** Get a pointer to the layer 3 (e.g. IP) header.
2213 * @param packet  The libtrace packet to find the layer 3 header for
2214 * @param[out] ethertype The ethertype of the layer 3 header
2215 * @param[out] remaining The amount of captured data remaining in the packet starting from the returned pointer, i.e. including the layer 3 header.
2216 *
2217 * @return A pointer to the layer 3 header. If no layer 3 header is present in
2218 * the packet, NULL is returned. If the layer 3 header is truncated, a valid
2219 * pointer will still be returned so be sure to check the value of remaining
2220 * before attempting to process the returned header.
2221 *
2222 * remaining may be NULL, otherwise it will be set to the number of captured
2223 * bytes after the pointer returned.
2224 */
2225DLLEXPORT
2226void *trace_get_layer3(const libtrace_packet_t *packet,
2227                uint16_t *ethertype, uint32_t *remaining);
2228
2229/** Calculates the expected IP checksum for a packet.
2230 * @param packet        The libtrace packet to calculate the checksum for
2231 * @param[out] csum     The checksum that is calculated by this function. This
2232 *                      may not be NULL.
2233 *
2234 * @return A pointer to the original checksum field within the IP
2235 * header. If the checksum field is not present in the packet, NULL is returned.
2236 *
2237 * @note The return value points to the checksum that exists within the current
2238 * packet. The value in csum is the value that the checksum should be, given
2239 * the current packet contents. 
2240 *
2241 * @note This function involves the use of a memcpy, so be careful about
2242 * calling it excessively if performance is a concern for you.
2243 *
2244 * New in libtrace 3.0.17
2245 */
2246DLLEXPORT uint16_t *trace_checksum_layer3(libtrace_packet_t *packet,
2247                uint16_t *csum);
2248
2249/** Calculates the expected checksum for the transport header in a packet.
2250 * @param packet        The libtrace packet to calculate the checksum for
2251 * @param[out] csum     The checksum that is calculated by this function. This
2252 *                      may not be NULL.
2253 *
2254 * @return A pointer to the original checksum field within the transport
2255 * header. If the checksum field is not present in the packet, NULL is returned.
2256 *
2257 * @note The return value points to the checksum that exists within the current
2258 * packet. The value in csum is the value that the checksum should be, given
2259 * the current packet contents. 
2260 *
2261 * @note This function involves the use of a memcpy, so be careful about
2262 * calling it excessively if performance is a concern for you.
2263 *
2264 * @note Because transport checksums are calculated across the entire payload,
2265 * truncated packets will result in NULL being returned.
2266 *
2267 * This function will determine the appropriate checksum for whatever transport
2268 * layer header is present in the provided packet. At this stage, this only
2269 * currently works for TCP, UDP and ICMP packets.
2270 *
2271 * Be wary of TCP checksum offloading if you are examining the checksum of
2272 * packets captured on the same host that generated them!
2273 *
2274 * New in libtrace 3.0.17
2275 */
2276DLLEXPORT uint16_t *trace_checksum_transport(libtrace_packet_t *packet,
2277                uint16_t *csum);
2278
2279/** Calculates the fragment offset in bytes for an IP packet
2280 * @param packet        The libtrace packet to calculate the offset for
2281 * @param[out] more     A boolean flag to indicate whether there are more
2282 *                      fragments after the current packet.
2283 * @return The fragment offset for the packet in bytes. If the packet is not
2284 * an IP packet or the fragment offset is not present in packet, the return
2285 * value will be 0.
2286 *
2287 * @note The value returned is in bytes, not 8-octet units as it is stored
2288 * in the fragment offset field in the headers. In other words, libtrace
2289 * automatically does the multiplication for you.
2290 *
2291 * The value passed in for 'more' does not matter; it will be overwritten
2292 * with the value of the More Fragments flag from the IP header.
2293 *
2294 * New in libtrace 3.0.20
2295 */
2296DLLEXPORT uint16_t trace_get_fragment_offset(const libtrace_packet_t *packet,
2297                uint8_t *more);
2298
2299/** Gets a pointer to the transport layer header (if any)
2300 * @param packet   The libtrace packet to find the transport header for
2301 * @param[out] proto    The protocol present at the transport layer.
2302 * @param[out] remaining The amount of captured data remaining in the packet
2303 * starting from the returned pointer, i.e. including the transport header.
2304 *
2305 * @return A pointer to the transport layer header. If no transport header is
2306 * present in the packet, NULL is returned. If the transport header is
2307 * truncated, a valid pointer will still be returned so be sure to check the
2308 * value of remaining before attempting to process the returned header.
2309 *
2310 * remaining may be NULL, otherwise it will be set to the number of captured
2311 * bytes after the returned pointer.
2312 *
2313 * @note proto may be NULL if proto is unneeded.
2314 */
2315DLLEXPORT void *trace_get_transport(const libtrace_packet_t *packet,
2316                uint8_t *proto, uint32_t *remaining);
2317
2318/** Gets a pointer to the payload following an IPv4 header
2319 * @param ip            The IPv4 Header
2320 * @param[out] proto    The protocol of the header following the IPv4 header
2321 * @param[in,out] remaining Updated with the number of captured bytes remaining
2322 *
2323 * @return A pointer to the transport layer header, or NULL if no subsequent
2324 * header is present.
2325 *
2326 * When calling this function, remaining must contain the number of captured
2327 * bytes remaining in the packet starting from the IPv4 header (including the
2328 * IPv4 header itself).
2329 *
2330 * remaining will be decremented by the size of the IPv4 header (including any
2331 * options). If the IPv4 header is complete but there are zero bytes of payload
2332 * after the IPv4 header, a pointer to where the payload would be is returned
2333 * and remaining will be set to 0.  If the IPv4 header is incomplete, NULL will
2334 * be returned and remaining will be set to 0. Therefore, it is very important
2335 * to check the value of remaining after calling this function.
2336 *
2337 * proto may be NULL, in which case it won't be updated.
2338 *
2339 * @note This is similar to trace_get_transport_from_ip in libtrace2
2340 */
2341DLLEXPORT void *trace_get_payload_from_ip(libtrace_ip_t *ip, uint8_t *proto,
2342                uint32_t *remaining);
2343
2344/** Gets a pointer to the payload following an IPv6 header
2345 * @param ipptr         The IPv6 Header
2346 * @param[out] proto    The protocol of the header following the IPv6 header
2347 * @param[in,out] remaining Updated with the number of captured bytes remaining
2348 *
2349 * @return A pointer to the transport layer header, or NULL if no subsequent
2350 * header is present.
2351 *
2352 * When calling this function, remaining must contain the number of captured
2353 * bytes remaining in the packet starting from the IPv6 header (including the
2354 * IPv6 header itself).
2355 *
2356 * remaining will be decremented by the size of the IPv6 header (including any
2357 * options). If the IPv6 header is complete but there are zero bytes of payload
2358 * after the IPv6 header, a pointer to where the payload would be is returned
2359 * and remaining will be set to 0.  If the IPv6 header is incomplete, NULL will
2360 * be returned and remaining will be set to 0. Therefore, it is very important
2361 * to check the value of remaining after calling this function.
2362 *
2363 * proto may be NULL, in which case it won't be updated.
2364 *
2365 */
2366DLLEXPORT void *trace_get_payload_from_ip6(libtrace_ip6_t *ipptr,
2367                uint8_t *proto, uint32_t *remaining);
2368
2369/** Gets a pointer to the payload following a link header
2370 * @param linkptr       A pointer to the link layer header
2371 * @param linktype      The linktype of the link header being examined
2372 * @param[out] type     An output variable for the ethernet type
2373 * @param[in,out] remaining Updated with the number of captured bytes remaining
2374 *
2375 * @return A pointer to the header following the link header, or NULL if no
2376 * subsequent header is present.
2377 *
2378 * When calling this function, remaining must contain the number of captured
2379 * bytes remaining in the packet starting from the link header (including the
2380 * link header itself). remaining will be updated to contain the number of
2381 * bytes remaining after the link header has been skipped.
2382 *
2383 * @deprecated This function is deprecated: you should be using
2384 * trace_get_payload_from_layer2() or trace_get_payload_from_meta() instead.
2385 *
2386 */
2387DLLEXPORT void *trace_get_payload_from_link(void *linkptr,
2388                libtrace_linktype_t linktype,
2389                uint16_t *type, uint32_t *remaining);
2390
2391/** Gets a pointer to the payload following an 802.1q (VLAN) header.
2392 * @param vlan      A pointer to the VLAN header
2393 * @param[out] type  The ethernet type, replaced with the VLAN ether type
2394 * @param[in,out] remaining Updated with the number of captured bytes remaining
2395 *
2396 * @return A pointer to the header beyond the VLAN header, if one is present.
2397 * Otherwise, returns NULL. 
2398 *
2399 * When calling this function, remaining must contain the number of captured
2400 * bytes remaining in the packet starting from the VLAN header (including the
2401 * VLAN header itself). remaining will be updated to contain the number of
2402 * bytes remaining after the VLAN header has been skipped.
2403 *
2404 * If the VLAN header is complete but there are zero bytes of payload after
2405 * the VLAN header, a pointer to where the payload would be is returned and
2406 * remaining will be set to 0.  If the VLAN header is incomplete, NULL will be
2407 * returned and remaining will be set to 0. Therefore, it is important to check
2408 * the value of remaining after calling this function.
2409 *
2410 * type will be set to the ethertype of the VLAN payload. This parameter is not
2411 * mandatory, but is highly recommended.
2412 *
2413 */
2414DLLEXPORT void *trace_get_payload_from_vlan(
2415                void *vlan, uint16_t *type, uint32_t *remaining);
2416
2417/** Gets a pointer to the payload following an MPLS header.
2418 * @param mpls      A pointer to the MPLS header
2419 * @param[out] type  The ethernet type, replaced by the ether type of the
2420 * returned header - 0x0000 if an Ethernet header is returned
2421 * @param[in,out] remaining Updated with the number of captured bytes remaining
2422 *
2423 * @return A pointer to the header beyond the MPLS label, if one is present.
2424 * Will return NULL if there is not enough bytes remaining to skip past the
2425 * MPLS label.
2426 *
2427 * When calling this function, remaining must contain the number of captured
2428 * bytes remaining in the packet starting from the MPLS header (including the
2429 * MPLS header itself). remaining will be updated to contain the number of
2430 * bytes remaining after the MPLS header has been skipped.
2431 *
2432 * If the MPLS header is complete but there are zero bytes of payload after
2433 * the MPLS header, a pointer to where the payload would be is returned and
2434 * remaining will be set to 0.  If the MPLS header is incomplete, NULL will be
2435 * returned and remaining will be set to 0. Therefore, it is important to check
2436 * the value of remaining after calling this function.
2437 *
2438 * type will be set to the ethertype of the MPLS payload. This parameter is
2439 * mandatory - it may not be NULL.
2440 *
2441 * @note This function will only remove one MPLS label at a time - the type
2442 * will be set to 0x8847 if there is another MPLS label following the one
2443 * skipped by this function.
2444 *
2445 */
2446DLLEXPORT void *trace_get_payload_from_mpls(
2447                void *mpls, uint16_t *type, uint32_t *remaining);
2448
2449/** Gets a pointer to the payload following a PPPoE header
2450 * @param pppoe      A pointer to the PPPoE header
2451 * @param[out] type  The ethernet type, replaced by the ether type of the
2452 * returned header - 0x0000 if an Ethernet header is returned
2453 * @param[in,out] remaining  Updated with the number of captured bytes remaining
2454 *
2455 * @return A pointer to the header beyond the PPPoE header. NOTE that this
2456 * function will also skip over the PPP header that will immediately follow
2457 * the PPPoE header. This function will return NULL if there are not enough
2458 * bytes remaining to skip past both the PPPoE and PPP headers.
2459 *
2460 * When calling this function, remaining must contain the number of captured
2461 * bytes remaining in the packet starting from the PPPoE header (including the
2462 * PPPoE header itself). remaining will be updated to contain the number of
2463 * bytes remaining after the PPPoE and PPP headers have been removed.
2464 *
2465 * If the PPPoE and PPP headers are complete but there are zero bytes of
2466 * payload after the PPP header, a pointer to where the payload would be is
2467 * returned and remaining will be set to 0.  If the PPPoE or PPP header is
2468 * incomplete, NULL will be returned and remaining will be set to 0. Therefore,
2469 * it is important to check the value of remaining after calling this function.
2470 *
2471 * type will be set to the ether type of the PPP payload. This parameter is
2472 * mandatory - it may not be NULL.
2473 *
2474 */
2475DLLEXPORT void *trace_get_payload_from_pppoe(
2476                void *pppoe, uint16_t *type, uint32_t *remaining);
2477
2478/** Gets a pointer to the payload following a TCP header
2479 * @param tcp           A pointer to the TCP header
2480 * @param[in,out] remaining Updated with the number of captured bytes remaining
2481 *
2482 * @return A pointer to the TCP payload, or NULL if the TCP header is truncated.
2483 *
2484 * When calling this function, remaining must contain the number of captured
2485 * bytes remaining in the packet starting from the TCP header (including the
2486 * TCP header itself). remaining will be updated to contain the number of
2487 * bytes remaining after the TCP header has been skipped.
2488 *
2489 * If the TCP header is complete but there are zero bytes of payload after
2490 * the TCP header, a pointer to where the payload would be is returned and
2491 * remaining will be set to 0.  If the TCP header is incomplete, NULL will be
2492 * returned and remaining will be set to 0. Therefore, it is important to check
2493 * the value of remaining after calling this function.
2494 *
2495 */
2496DLLEXPORT void *trace_get_payload_from_tcp(libtrace_tcp_t *tcp,
2497                uint32_t *remaining);
2498
2499/** Gets a pointer to the payload following a UDP header
2500 * @param udp           A pointer to the UDP header
2501 * @param[in,out] remaining Updated with the number of captured bytes remaining
2502 *
2503 * @return A pointer to the UDP payload, or NULL if the UDP header is truncated.
2504 *
2505 * When calling this function, remaining must contain the number of captured
2506 * bytes remaining in the packet starting from the UDP header (including the
2507 * UDP header itself). remaining will be updated to contain the number of
2508 * bytes remaining after the UDP header has been skipped.
2509 *
2510 * If the UDP header is complete but there are zero bytes of payload after
2511 * the UDP header, a pointer to where the payload would be is returned and
2512 * remaining will be set to 0.  If the UDP header is incomplete, NULL will be
2513 * returned and remaining will be set to 0. Therefore, it is important to check
2514 * the value of remaining after calling this function.
2515 *
2516 */
2517DLLEXPORT void *trace_get_payload_from_udp(libtrace_udp_t *udp, uint32_t *remaining);
2518
2519/** Gets a pointer to the payload following a ICMP header
2520 * @param icmp           A pointer to the ICMP header
2521 * @param[in,out] remaining Updated with the number of captured bytes remaining
2522 *
2523 * @return A pointer to the ICMP payload, or NULL if the ICMP header is
2524 * truncated.
2525 *
2526 * When calling this function, remaining must contain the number of captured
2527 * bytes remaining in the packet starting from the ICMP header (including the
2528 * ICMP header itself). remaining will be updated to contain the number of
2529 * bytes remaining after the ICMP header has been skipped.
2530 *
2531 * If the ICMP header is complete but there are zero bytes of payload after
2532 * the ICMP header, a pointer to where the payload would be is returned and
2533 * remaining will be set to 0.  If the ICMP header is incomplete, NULL will be
2534 * returned and remaining will be set to 0. Therefore, it is important to check
2535 * the value of remaining after calling this function.
2536 *
2537 * @note In the case of some ICMP messages, the payload may be the IP header
2538 * from the packet that triggered the ICMP message.
2539 *
2540 */
2541DLLEXPORT void *trace_get_payload_from_icmp(libtrace_icmp_t *icmp,
2542                uint32_t *remaining);
2543
2544/** Gets a pointer to the payload following a ICMPv6 header
2545 * @param icmp           A pointer to the ICMPv6 header
2546 * @param[in,out] remaining Updated with the number of captured bytes remaining
2547 *
2548 * @return A pointer to the ICMPv6 payload, or NULL if the ICMPv6 header is
2549 * truncated.
2550 *
2551 * When calling this function, remaining must contain the number of captured
2552 * bytes remaining in the packet starting from the ICMPv6 header (including the
2553 * ICMP header itself). remaining will be updated to contain the number of
2554 * bytes remaining after the ICMPv6 header has been skipped.
2555 *
2556 * If the ICMPv6 header is complete but there are zero bytes of payload after
2557 * the header, a pointer to where the payload would be is returned and
2558 * remaining will be set to 0.  If the ICMPv6 header is incomplete, NULL will be
2559 * returned and remaining will be set to 0. Therefore, it is important to check
2560 * the value of remaining after calling this function.
2561 *
2562 * @note In the case of some ICMPv6 messages, the payload may be the IP header
2563 * from the packet that triggered the ICMP message.
2564 *
2565 */
2566DLLEXPORT void *trace_get_payload_from_icmp6(libtrace_icmp6_t *icmp,
2567                uint32_t *remaining);
2568
2569/** Gets a pointer to the payload following a GRE header
2570 * @param         gre       A pointer to the beginning of the GRE header.
2571 * @param[in,out] remaining Updated with the number of captured bytes remaining.
2572 *
2573 * @return A pointer to the GRE payload, or NULL if the GRE header is truncated.
2574 *
2575 * When calling this function, remaining must contain the number of captured
2576 * bytes remaining in the packet starting from the GRE header (including the
2577 * GRE header itself). remaining will be updated to contain the number of
2578 * bytes remaining after the GRE header has been skipped.
2579 *
2580 * If the GRE header is complete but there are zero bytes of payload after
2581 * the header, a pointer to where the payload would be is returned and
2582 * remaining will be set to 0.  If the GRE header is incomplete, NULL will be
2583 * returned and remaining will be set to 0. Therefore, it is important to check
2584 * the value of remaining after calling this function.
2585 */
2586DLLEXPORT void *trace_get_payload_from_gre(libtrace_gre_t *gre,
2587                uint32_t *remaining);
2588
2589/** Gets a pointer to the payload following a VXLAN header
2590 * @param         udp       A pointer to the beginning of the UDP header.
2591 * @param[in,out] remaining Updated with the number of captured bytes remaining.
2592 *
2593 * @return A pointer to the beginning of the VXLAN header, or NULL if the UDP
2594 * header is truncated, or this is not a VXLAN packet.
2595 *
2596 */
2597DLLEXPORT libtrace_vxlan_t *trace_get_vxlan_from_udp(libtrace_udp_t *udp,
2598                uint32_t *remaining);
2599
2600/** Gets a pointer to the payload following a VXLAN header
2601 * @param         vxlan       A pointer to the beginning of the VXLAN header.
2602 * @param[in,out] remaining Updated with the number of captured bytes remaining.
2603 *
2604 * @return A pointer to the VXLAN payload, or NULL if the VXLAN header is
2605 * truncated.
2606 *
2607 * When calling this function, remaining must contain the number of captured
2608 * bytes remaining in the packet starting from the VXLAN header (including the
2609 * VXLAN header itself). remaining will be updated to contain the number of
2610 * bytes remaining after the VXLAN header has been skipped.
2611 *
2612 * If the VXLAN header is complete but there are zero bytes of payload after
2613 * the header, a pointer to where the payload would be is returned and
2614 * remaining will be set to 0.  If the VXLAN header is incomplete, NULL will be
2615 * returned and remaining will be set to 0. Therefore, it is important to check
2616 * the value of remaining after calling this function.
2617 */
2618DLLEXPORT void *trace_get_payload_from_vxlan(libtrace_vxlan_t *vxlan,
2619                uint32_t *remaining);
2620
2621/** Get a pointer to the TCP header (if present)
2622 * @param packet        The packet to get the TCP header from
2623 *
2624 * @return A pointer to the TCP header, or NULL if there is not a complete TCP
2625 * header present in the packet.
2626 *
2627 * This is a short-cut function enabling quick and easy access to the TCP
2628 * header if that is all you care about. However, we recommend the use of the
2629 * more generic trace_get_transport() function instead.
2630 *
2631 * @note Unlike trace_get_transport(), this function will return NULL if the
2632 * TCP header is incomplete or truncated.
2633 */
2634DLLEXPORT SIMPLE_FUNCTION
2635libtrace_tcp_t *trace_get_tcp(libtrace_packet_t *packet);
2636
2637/** Get a pointer to the TCP header following an IPv4 header (if present)
2638 * @param ip            The IP header to find the subsequent TCP header for
2639 * @param[in,out] remaining Updated with the number of captured bytes remaining
2640 *
2641 * @return A pointer to the TCP header, or NULL if no TCP header is present in
2642 * the packet.
2643 *
2644 * When calling this function, remaining must contain the number of captured
2645 * bytes remaining in the packet starting from the IP header (including the
2646 * IP header itself). remaining will be updated to contain the number of
2647 * bytes remaining after the IP header has been skipped.
2648 *
2649 * If the IP header is complete but there are zero bytes of payload after
2650 * the IP header, a pointer to where the payload would be is returned and
2651 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
2652 * returned and remaining will be set to 0. Therefore, it is important to check
2653 * the value of remaining after calling this function.
2654 *
2655 * @note This function is rather redundant now that the layer 3 header is
2656 * cached. There should be no performance advantage for the user to call this
2657 * function over just calling trace_get_transport().
2658 *
2659 * @note The last parameter has changed from libtrace2
2660 */
2661DLLEXPORT SIMPLE_FUNCTION
2662libtrace_tcp_t *trace_get_tcp_from_ip(libtrace_ip_t *ip, uint32_t *remaining);
2663
2664/** Get a pointer to the UDP header (if present)
2665 * @param packet        The packet to get the UDP header from
2666 *
2667 * @return A pointer to the UDP header, or NULL if there is not a complete UDP
2668 * header present in the packet.
2669 *
2670 * This is a short-cut function enabling quick and easy access to the UDP
2671 * header if that is all you care about. However, we recommend the use of the
2672 * more generic trace_get_transport() function instead.
2673 *
2674 * @note Unlike trace_get_transport(), this function will return NULL if the
2675 * UDP header is incomplete or truncated.
2676 */
2677DLLEXPORT SIMPLE_FUNCTION
2678libtrace_udp_t *trace_get_udp(libtrace_packet_t *packet);
2679
2680/** Get a pointer to the UDP header following an IPv4 header (if present)
2681 * @param ip            The IP header to find the subsequent UDP header for
2682 * @param[in,out] remaining Updated with the number of captured bytes remaining
2683 *
2684 * @return A pointer to the UDP header, or NULL if no UDP header is present in
2685 * the packet.
2686 *
2687 * When calling this function, remaining must contain the number of captured
2688 * bytes remaining in the packet starting from the IP header (including the
2689 * IP header itself). remaining will be updated to contain the number of
2690 * bytes remaining after the IP header has been skipped.
2691 *
2692 * If the IP header is complete but there are zero bytes of payload after
2693 * the IP header, a pointer to where the payload would be is returned and
2694 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
2695 * returned and remaining will be set to 0. Therefore, it is important to check
2696 * the value of remaining after calling this function.
2697 *
2698 * @note This function is rather redundant now that the layer 3 header is
2699 * cached. There should be no performance advantage for the user to call this
2700 * function over just calling trace_get_transport().
2701 *
2702 * @note The last parameter has changed from libtrace2
2703 */
2704DLLEXPORT SIMPLE_FUNCTION
2705libtrace_udp_t *trace_get_udp_from_ip(libtrace_ip_t *ip,uint32_t *remaining);
2706
2707/** Get a pointer to the ICMP header (if present)
2708 * @param packet        The packet to get the ICMP header from
2709 *
2710 * @return A pointer to the ICMP header, or NULL if there is not a complete
2711 * ICMP header present in the packet.
2712 *
2713 * This is a short-cut function enabling quick and easy access to the ICMP
2714 * header if that is all you care about. However, we recommend the use of the
2715 * more generic trace_get_transport() function instead.
2716 *
2717 * @note Unlike trace_get_transport(), this function will return NULL if the
2718 * ICMP header is incomplete or truncated.
2719 */
2720DLLEXPORT SIMPLE_FUNCTION
2721libtrace_icmp_t *trace_get_icmp(libtrace_packet_t *packet);
2722
2723/** Get a pointer to the ICMPv6 header (if present)
2724 * @param packet        The packet to get the ICMPv6 header from
2725 *
2726 * @return A pointer to the ICMPv6 header, or NULL if there is not a complete
2727 * ICMP header present in the packet.
2728 *
2729 * This is a short-cut function enabling quick and easy access to the ICMPv6
2730 * header if that is all you care about. However, we recommend the use of the
2731 * more generic trace_get_transport() function instead.
2732 *
2733 * @note Unlike trace_get_transport(), this function will return NULL if the
2734 * ICMPv6 header is incomplete or truncated.
2735 */
2736DLLEXPORT SIMPLE_FUNCTION
2737libtrace_icmp6_t *trace_get_icmp6(libtrace_packet_t *packet);
2738
2739/** Get a pointer to the ICMP header following an IPv4 header (if present)
2740 * @param ip            The IP header to find the subsequent ICMP header for
2741 * @param[in,out] remaining Updated with the number of captured bytes remaining
2742 *
2743 * @return A pointer to the ICMP header, or NULL if no UDP header is present in
2744 * the packet.
2745 *
2746 * When calling this function, remaining must contain the number of captured
2747 * bytes remaining in the packet starting from the IP header (including the
2748 * IP header itself). remaining will be updated to contain the number of
2749 * bytes remaining after the IP header has been skipped.
2750 *
2751 * If the IP header is complete but there are zero bytes of payload after
2752 * the IP header, a pointer to where the payload would be is returned and
2753 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
2754 * returned and remaining will be set to 0. Therefore, it is important to check
2755 * the value of remaining after calling this function.
2756 *
2757 * @note This function is rather redundant now that the layer 3 header is
2758 * cached. There should be no performance advantage for the user to call this
2759 * function over just calling trace_get_transport().
2760 *
2761 * @note The last parameter has changed from libtrace2
2762 */
2763DLLEXPORT SIMPLE_FUNCTION
2764libtrace_icmp_t *trace_get_icmp_from_ip(libtrace_ip_t *ip,uint32_t *remaining);
2765
2766/** Get a pointer to the OSPF header (if present)
2767 * @param packet        The packet to get the OSPF header from
2768 * @param[out] version  The OSPF version number
2769 * @param[out] remaining        Updated with the number of captured bytes remaining
2770 * @return A pointer to the start of the OSPF header or NULL if there is no
2771 * complete OSPF header present in the packet
2772 *
2773 * This is a short-cut function enabling quick and easy access to the OSPF
2774 * header. If you only care about the OSPF header, this function may be useful
2775 * but we otherwise recommend the use of the more generic trace_get_transport()
2776 * function instead.
2777 *
2778 * Upon return, 'version' is updated to contain the OSPF version number for the
2779 * packet so that the returned pointer may be cast to the correct type.
2780 * The version parameter MUST contain a valid pointer; it MUST NOT be NULL.
2781 *
2782 * 'remaining' is also set to contain the number of captured bytes remaining
2783 * starting from the pointer returned by this function.
2784 *
2785 * @note Unlike trace_get_transport(), this function will return NULL if the
2786 * OSPF header is incomplete or truncated.
2787 */
2788DLLEXPORT SIMPLE_FUNCTION
2789void *trace_get_ospf_header(libtrace_packet_t *packet, uint8_t *version,
2790                uint32_t *remaining);
2791
2792/** Get a pointer to the contents of the OSPF packet *after* the OSPF header
2793 * @param header        The OSPF header to get the OSPF contents from
2794 * @param[out] ospf_type        The OSPF packet type
2795 * @param[in, out] remaining    Updated with the number of captured bytes remaining
2796 * @return A pointer to the first byte after the OSPF header.
2797 *
2798 * This function returns a void pointer that can be cast appropriately
2799 * based on the ospf_type. For example, if the ospf_type is TRACE_OSPF_HELLO
2800 * then the return pointer should be cast as a libtrace_ospf_hello_v2_t
2801 * structure.
2802 *
2803 * If the OSPF header is truncated, then NULL will be returned. If the OSPF
2804 * contents are missing or truncated, the pointer to the start of the content
2805 * will still be returned so be careful to check the value of remaining.
2806 *
2807 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2808 * packet starting from the beginning of the OSPF header. It will be updated
2809 * to contain the number of bytes remaining from the start of the OSPF contents.
2810 *
2811 * @note This function only works for OSPF version 2 packets.
2812 * @note Use trace_get_first_ospf_lsa_v2_from_X() and trace_get_next_ospf_lsa_v2() to read the LSAs from Link State Update packets.
2813 * @note Use trace_get_first_ospf_lsa_v2_from_X() and trace_get_next_ospf_lsa_header_v2() to read the LSA headers from Link State Ack packets.
2814 *
2815 */
2816DLLEXPORT SIMPLE_FUNCTION
2817void *trace_get_ospf_contents_v2(libtrace_ospf_v2_t *header,
2818                uint8_t *ospf_type, uint32_t *remaining);
2819
2820/** Get a pointer to the start of the first LSA contained within an LS Update packet
2821 * @param ls_update     Pointer to the LS Update header
2822 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2823 * @return A pointer to the first LSA in the packet.
2824 *
2825 * This function simply skips past the LS Update header to provide a suitable
2826 * pointer to pass into trace_get_next_ospf_lsa_v2.
2827 *
2828 * If the OSPF packet is truncated, then NULL will be returned.
2829 *
2830 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2831 * packet starting from the beginning of the LS Update header. It will be
2832 * updated to contain the number of bytes remaining from the start of the
2833 * first LSA.
2834 *
2835 * @note This function only works for OSPF version 2 packets.
2836 * @note trace_get_next_ospf_lsa_v2() should be subsequently used to process the LSAs
2837 */
2838DLLEXPORT SIMPLE_FUNCTION
2839unsigned char *trace_get_first_ospf_lsa_from_update_v2(
2840                libtrace_ospf_ls_update_t *ls_update,
2841                uint32_t *remaining);
2842
2843/** Get a pointer to the start of the first LSA contained within an Database Description packet
2844 * @param db_desc       Pointer to the Database Description header
2845 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2846 * @return A pointer to the first LSA in the packet.
2847 *
2848 * This function simply skips past the Database Description header to provide a
2849 * suitable pointer to pass into trace_get_next_ospf_lsa_header_v2.
2850 *
2851 * If the OSPF packet is truncated, then NULL will be returned.
2852 *
2853 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2854 * packet starting from the beginning of the Database Description header. It
2855 * will be updated to contain the number of bytes remaining from the start of
2856 * the first LSA.
2857 *
2858 * @note This function only works for OSPF version 2 packets.
2859 * @note trace_get_next_ospf_lsa_header_v2() should be subsequently used to process the LSA headers
2860 */
2861DLLEXPORT SIMPLE_FUNCTION
2862unsigned char *trace_get_first_ospf_lsa_from_db_desc_v2(
2863                libtrace_ospf_db_desc_v2_t *db_desc,
2864                uint32_t *remaining);
2865
2866/** Get a pointer to the start of the first link contained within a Router LSA
2867 * @param lsa   Pointer to the Router LSA
2868 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2869 * @return A pointer to the first link in the packet.
2870 *
2871 * This function simply skips past the Router LSA header to provide a
2872 * suitable pointer to pass into trace_get_next_ospf_link_v2.
2873 *
2874 * If the OSPF packet is truncated, then NULL will be returned.
2875 *
2876 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2877 * packet starting from the beginning of the Router LSA (not including the LSA
2878 * header) header. It will be updated to contain the number of bytes remaining
2879 * from the start of the first Link.
2880 *
2881 * @note This function only works for OSPF version 2 packets.
2882 * @note trace_get_next_ospf_link_v2() should be subsequently used to process
2883 * the links
2884 */
2885DLLEXPORT SIMPLE_FUNCTION
2886unsigned char *trace_get_first_ospf_link_from_router_lsa_v2(
2887                libtrace_ospf_router_lsa_v2_t *lsa,
2888                uint32_t *remaining);
2889
2890/** Parses an OSPF Router LSA Link and finds the next Link (if there is one)
2891 * @param[in,out] current       Pointer to the next Link (updated by this function)
2892 * @param[out] link             Set to point to the Link located at the original value of current
2893 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2894 * @param[out] link_len         Set to the size of the Link pointed to by 'link'
2895 * @return 0 if there are no more links after the current one, 1 otherwise.
2896 *
2897 * When called, 'current' MUST point to an OSPF Router LSA link. Ideally, this
2898 * would come from either a call to
2899 * trace_get_first_ospf_link_from_router_lsa_v2() or a previous call of this
2900 * function.
2901 *
2902 * 'link' will be set to the value of 'current', so that the caller may then
2903 * do any processing they wish on that particular link. 'current' is advanced
2904 * to point to the next link and 'link_len' is updated to report the size of
2905 * the original link.
2906 *
2907 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2908 * packet starting from the beginning of the Link pointed to by 'current'.
2909 * It will be updated to contain the number of bytes remaining from the start
2910 * of the next link.
2911 *
2912 * If this function returns 0 but 'link' is NOT NULL, that link is still valid
2913 * but there are no more links after this one.
2914 * If this function returns 0 AND link is NULL, the link is obviously not
2915 * suitable for processing.
2916 *
2917 * @note This function only works for OSPF version 2 packets.
2918 */
2919DLLEXPORT SIMPLE_FUNCTION
2920int trace_get_next_ospf_link_v2(unsigned char **current,
2921                libtrace_ospf_link_v2_t **link,
2922                uint32_t *remaining,
2923                uint32_t *link_len);
2924
2925/** Parses an OSPF LSA and finds the next LSA (if there is one)
2926 * @param[in,out] current       Pointer to the next LSA (updated by this function)
2927 * @param[out] lsa_hdr          Set to point to the header of the LSA located at the original value of current
2928 * @param[out] lsa_body         Set to point to the body of the LSA located at the original value of current
2929 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2930 * @param[out] lsa_type         Set to the type of the LSA located at the original value of current
2931 * @param[out] lsa_length       Set to the size of the LSA located at the original value of current
2932 * @return 1 if there are more LSAs after the current one, 0 if there are no more LSAs to come, and -1 if the current LSA is incomplete, truncated or invalid.
2933 *
2934 * When called, 'current' MUST point to an OSPF LSA. Ideally, this would come
2935 * from either a call to trace_get_first_ospf_lsa_from_update_v2() or a
2936 * previous call of this function.
2937 *
2938 * This function should only be used to access COMPLETE LSAs, i.e. LSAs that
2939 * have both a header and a body. In OSPFv2, only the LSAs contained within
2940 * LSA Update packets meet this requirement. trace_get_next_ospf_lsa_header_v2
2941 * should be used to read header-only LSAs, e.g. those present in LS Acks.
2942 *
2943 * 'lsa_hdr' will be set to the value of 'current', so that the caller may then
2944 * do any processing they wish on that particular LSA. 'lsa_body' will be set
2945 * to point to the first byte after the LSA header. 'current' is advanced
2946 * to point to the next LSA. 'lsa_length' is updated to contain the size of
2947 * the parsed LSA, while 'lsa_type' is set to indicate the LSA type.
2948 *
2949 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2950 * packet starting from the beginning of the LSA pointed to by 'current'.
2951 * It will be updated to contain the number of bytes remaining from the start
2952 * of the next LSA.
2953 *
2954 * If this function returns 0 but 'lsa_hdr' is NOT NULL, that LSA is still
2955 * valid but there are no more LSAs after this one.
2956 * If this function returns 0 AND 'lsa_hdr' is NULL, the LSA is obviously not
2957 * suitable for processing.
2958 *
2959 * It is also recommended to check the value of 'lsa_body' before
2960 * de-referencing it. 'lsa_body' will be set to NULL if there is only an LSA
2961 * header present.
2962 *
2963 * @note This function only works for OSPF version 2 packets.
2964 *
2965 */
2966DLLEXPORT SIMPLE_FUNCTION
2967int trace_get_next_ospf_lsa_v2(unsigned char **current,
2968                libtrace_ospf_lsa_v2_t **lsa_hdr,
2969                unsigned char **lsa_body,
2970                uint32_t *remaining,
2971                uint8_t *lsa_type,
2972                uint16_t *lsa_length);
2973
2974/** Parses an OSPF LSA header and finds the next LSA (if there is one)
2975 * @param[in,out] current       Pointer to the next LSA (updated by this function)
2976 * @param[out] lsa_hdr          Set to point to the header of the LSA located at the original value of current
2977 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2978 * @param[out] lsa_length       Set to the size of the LSA located at the original value of current
2979 * @return 1 if there are more LSAs after the current one, 0 if there are no more LSAs to come, and -1 if the current LSA is incomplete, truncated or invalid.
2980 *
2981 * When called, 'current' MUST point to an OSPF LSA. Ideally, this would come
2982 * from either a call to trace_get_first_ospf_lsa_from_db_desc_v2() or a
2983 * previous call of this function.
2984 *
2985 * This function should only be used to access LSA headers, i.e. LSAs that
2986 * have a header only. In OSPFv2, the LSAs contained within LSA Ack and
2987 * Database Description packets meet this requirement.
2988 * trace_get_next_ospf_lsa_v2 should be used to read full LSAs, e.g. those
2989 * present in LS Updates.
2990 *
2991 * 'lsa_hdr' will be set to the value of 'current', so that the caller may then
2992 * do any processing they wish on that particular LSA header. 'current' is
2993 * advanced to point to the next LSA header. 'lsa_length' is updated to contain
2994 * the size of the parsed LSA header.
2995 *
2996 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2997 * packet starting from the beginning of the LSA pointed to by 'current'.
2998 * It will be updated to contain the number of bytes remaining from the start
2999 * of the next LSA.
3000 *
3001 * If this function returns 0 but 'lsa_hdr' is NOT NULL, that LSA is still
3002 * valid but there are no more LSAs after this one.
3003 * If this function returns 0 AND 'lsa_hdr' is NULL, the LSA is obviously not
3004 * suitable for processing.
3005 *
3006 * @note This function only works for OSPF version 2 packets.
3007 *
3008 */
3009DLLEXPORT SIMPLE_FUNCTION
3010int trace_get_next_ospf_lsa_header_v2(unsigned char **current,
3011                libtrace_ospf_lsa_v2_t **lsa_hdr,
3012                uint32_t *remaining,
3013                uint8_t *lsa_type,
3014                uint16_t *lsa_length);
3015
3016/** Extracts the metric field from an AS External LSA packet
3017 *
3018 * @param as_lsa        The AS External LSA
3019 * @returns The value of the metric field
3020 *
3021 * The metric field in the AS External LSA packet is a 24-bit value, which
3022 * is difficult to extract correctly. To avoid byte-ordering issues, use this
3023 * function which will extract the correct value for you.
3024 */
3025DLLEXPORT SIMPLE_FUNCTION
3026uint32_t trace_get_ospf_metric_from_as_external_lsa_v2(
3027                libtrace_ospf_as_external_lsa_v2_t *as_lsa);
3028
3029/** Extracts the metric field from a Summary LSA packet
3030 *
3031 * @param sum_lsa       The Summary LSA
3032 * @returns The value of the metric field
3033 *
3034 * The metric field in the Summary LSA packet is a 24-bit value, which
3035 * is difficult to extract correctly. To avoid byte-ordering issues, use this
3036 * function which will extract the correct value for you.
3037 */
3038DLLEXPORT SIMPLE_FUNCTION
3039uint32_t trace_get_ospf_metric_from_summary_lsa_v2(
3040                libtrace_ospf_summary_lsa_v2_t *sum_lsa);
3041
3042
3043/** Gets the destination MAC address for a given packet
3044 * @param packet        The packet to extract the destination MAC address from
3045 *
3046 * @return A pointer to the destination MAC address field in the layer 2
3047 * header, (or NULL if there is no destination MAC address or layer 2 header
3048 * available)
3049 *
3050 * @note This is a zero-copy function, so the memory that the returned pointer
3051 * points to is part of the packet itself.
3052 */
3053DLLEXPORT SIMPLE_FUNCTION
3054uint8_t *trace_get_destination_mac(libtrace_packet_t *packet);
3055
3056/** Gets the source MAC address for a given packet
3057 * @param packet        The packet to extract the source MAC address from
3058 *
3059 * @return A pointer to the source MAC address field in the layer 2
3060 * header, (or NULL if there is no source MAC address or layer 2 header
3061 * available)
3062 *
3063 * @note This is a zero-copy function, so the memory that the returned pointer
3064 * points to is part of the packet itself.
3065 */
3066DLLEXPORT SIMPLE_FUNCTION
3067uint8_t *trace_get_source_mac(libtrace_packet_t *packet);
3068
3069/** Get the source IP address for a given packet
3070 * @param packet        The packet to extract the source IP address from
3071 * @param addr          A pointer to a sockaddr structure to store the address
3072 *                      in. If NULL, static storage is used instead.
3073 * @return A pointer to a sockaddr holding a v4 or v6 IP address or on some
3074 * platforms a sockaddr holding a MAC address. Returns NULL if no source IP
3075 * address was available.
3076 *
3077 * @note The best way to use this function is to pass in a pointer to the
3078 * struct sockaddr_storage for the addr parameter. This will avoid problems
3079 * with trying to shoe-horn an IPv6 address into a sockaddr that only supports
3080 * IPv4.
3081 */
3082DLLEXPORT SIMPLE_FUNCTION
3083struct sockaddr *trace_get_source_address(const libtrace_packet_t *packet,
3084                struct sockaddr *addr);
3085
3086/** Get the source IP address for a packet and convert it into a string
3087 * @param packet        The packet to extract the source IP address from
3088 * @param space         A pointer to a character buffer to store the address
3089 *                      in. If NULL, static storage is used instead.
3090 * @param spacelen      The size of the buffer passed in via 'space'. Set this
3091 *                      to zero if you are going to pass in a NULL buffer.
3092 * @return A pointer to a character buffer containing the string representation
3093 * of the source IP address. For packets where there is no suitable IP address,
3094 * the source MAC will be returned instead. Returns NULL if no valid address
3095 * is available.
3096 *
3097 * @note Be wary of the possibility of the address being an IPv6 address - make
3098 * sure your buffer is large enough!
3099 *
3100 * New in libtrace 3.0.17.
3101 */
3102DLLEXPORT SIMPLE_FUNCTION
3103char *trace_get_source_address_string(const libtrace_packet_t *packet,
3104                char *space, int spacelen);
3105
3106/** Get the destination IP address for a given packet
3107 * @param packet        The packet to extract the destination IP address from
3108 * @param addr          A pointer to a sockaddr structure to store the address
3109 *                      in. If NULL, static storage is used instead.
3110 * @return A pointer to a sockaddr holding a v4 or v6 IP address or on some
3111 * platforms a sockaddr holding a MAC address. Returns NULL if no destination
3112 * IP address was available.
3113 *
3114 * @note The best way to use this function is to pass in a pointer to the
3115 * struct sockaddr_storage for the addr parameter. This will avoid problems
3116 * with trying to shoe-horn an IPv6 address into a sockaddr that only supports
3117 * IPv4.
3118 */
3119DLLEXPORT SIMPLE_FUNCTION
3120struct sockaddr *trace_get_destination_address(const libtrace_packet_t *packet,
3121                struct sockaddr *addr);
3122
3123/** Get the destination IP address for a packet and convert it into a string
3124 * @param packet        The packet to extract the destination IP address from
3125 * @param space         A pointer to a character buffer to store the address
3126 *                      in. If NULL, static storage is used instead.
3127 * @param spacelen      The size of the buffer passed in via 'space'. Set this
3128 *                      to zero if you are going to pass in a NULL buffer.
3129 * @return A pointer to a character buffer containing the string representation
3130 * of the destination IP address. For packets where there is no suitable IP
3131 * address, the destination MAC will be returned instead. Returns NULL if no
3132 * valid address is available.
3133 *
3134 * @note Be wary of the possibility of the address being an IPv6 address - make
3135 * sure your buffer is large enough!
3136 *
3137 * New in libtrace 3.0.17.
3138 */
3139DLLEXPORT SIMPLE_FUNCTION
3140char *trace_get_destination_address_string(const libtrace_packet_t *packet,
3141                char *space, int spacelen);
3142
3143/** Parses an IP or TCP option
3144 * @param[in,out] ptr   The pointer to the current option
3145 * @param[in,out] len   The total length of all the remaining options
3146 * @param[out] type     The type of the option
3147 * @param[out] optlen   The length of the option
3148 * @param[out] data     The data of the option
3149 *
3150 * @return bool true if there is another option (and the fields are filled in)
3151 *               or false if this was the last option.
3152 *
3153 * This updates ptr to point to the next option after this one, and updates
3154 * len to be the number of bytes remaining in the options area.  Type is updated
3155 * to be the code of this option, and data points to the data of this option,
3156 * with optlen saying how many bytes there are.
3157 *
3158 * @note Beware of fragmented packets.
3159 */
3160DLLEXPORT int trace_get_next_option(unsigned char **ptr,int *len,
3161                        unsigned char *type,
3162                        unsigned char *optlen,
3163                        unsigned char **data);
3164
3165/*@}*/
3166
3167/** @name Time
3168 * These functions deal with the timestamp describing when a packet was
3169 * captured and can convert it into various formats
3170 * @{
3171 */
3172
3173/** Get the packet timestamp in the DAG time format
3174 * @param packet        The packet to extract the timestamp from
3175 *
3176 * @return a 64 bit timestamp in DAG ERF format (upper 32 bits are the seconds
3177 * past 1970-01-01, the lower 32bits are partial seconds)
3178 */
3179DLLEXPORT SIMPLE_FUNCTION
3180uint64_t trace_get_erf_timestamp(const libtrace_packet_t *packet);
3181
3182/** Get the packet timestamp as a struct timeval
3183 * @param packet        The packet to extract the timestamp from
3184 *
3185 * @return The time that this packet was captured in a struct timeval
3186 */
3187DLLEXPORT SIMPLE_FUNCTION
3188struct timeval trace_get_timeval(const libtrace_packet_t *packet);
3189
3190/** Get the packet timestamp as a struct timespec
3191 * @param packet        The packet to extract the timestamp from
3192 *
3193 * @return The time that this packet was captured in a struct timespec
3194 */
3195DLLEXPORT SIMPLE_FUNCTION
3196struct timespec trace_get_timespec(const libtrace_packet_t *packet);
3197
3198/** Get the packet timestamp in floating point seconds
3199 * @param packet        The packet to extract the timestamp from
3200 *
3201 * @return time that this packet was seen in 64-bit floating point seconds from
3202 * the UNIX epoch (1970-01-01 00:00:00 UTC).
3203 */
3204DLLEXPORT SIMPLE_FUNCTION
3205double trace_get_seconds(const libtrace_packet_t *packet);
3206
3207/** Seek within an input trace to a time specified in floating point seconds
3208 * @param trace         The input trace to seek within
3209 * @param seconds       The time to seek to, in floating point seconds
3210 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
3211 * the error that occurred.
3212 *
3213 * This will make the next packet read to be the first packet to occur at or
3214 * after the specified time.  This must be called in the configuration state
3215 * (i.e. before trace_start() or after trace_pause()).
3216 *
3217 * The time format accepted by this function is 64-bit floating point seconds
3218 * since the UNIX epoch (1970-01-01 00:00:00 UTC), i.e. the same format as
3219 * trace_get_seconds().
3220 *
3221 * @note This function may be extremely slow.
3222 */
3223DLLEXPORT int trace_seek_seconds(libtrace_t *trace, double seconds);
3224
3225/** Seek within an input trace to a time specified as a timeval
3226 * @param trace         The input trace to seek within
3227 * @param tv            The time to seek to, as a timeval
3228 *
3229 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
3230 * the error that occurred.
3231 *
3232 * This will make the next packet read to be the first packet to occur at or
3233 * after the specified time.  This must be called in the configuration state
3234 * (i.e. before trace_start() or after trace_pause()).
3235 *
3236 * @note This function may be extremely slow.
3237 */
3238DLLEXPORT int trace_seek_timeval(libtrace_t *trace, struct timeval tv);
3239
3240/** Seek within an input trace to a time specified as an ERF timestamp
3241 * @param trace         The input trace to seek within
3242 * @param ts            The time to seek to, as an ERF timestamp
3243 *
3244 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
3245 * the error that occurred.
3246 *
3247 * This will make the next packet read to be the first packet to occur at or
3248 * after the specified time.  This must be called in the configuration state
3249 * (i.e. before trace_start() or after trace_pause()).
3250 *
3251 * The time format accepted by this function is the ERF timestamp, which is a
3252 * 64-bit value where the upper 32 bits are seconds since the UNIX epoch and
3253 * the lower 32 bits are partial seconds.
3254 *
3255 * @note This function may be extremely slow.
3256 */
3257DLLEXPORT int trace_seek_erf_timestamp(libtrace_t *trace, uint64_t ts);
3258
3259/*@}*/
3260
3261/** @name Sizes
3262 * This section deals with finding or setting the various different lengths
3263 * that a packet can have, e.g. capture lengths, wire lengths, etc.
3264 * @{
3265 */
3266/** Get the current size of the packet (in bytes), taking into account any
3267 * truncation or snapping that may have previously been performed.
3268 *
3269 * @param packet        The packet to determine the capture length for
3270 * @return The size of the packet read from the input trace, i.e. what is
3271 * actually available to libtrace at the moment.
3272 *
3273 * @note Most traces are header captures, so this value may not be the same
3274 * as the size of the packet when it was captured. Use trace_get_wire_length()
3275 * to get the original size of the packet.
3276 
3277 * @note This can (and often is) different for different packets in a trace!
3278 
3279 * @note This is sometimes called the "snaplen".
3280 *
3281 * @note The return size refers to the network-level payload of the packet and
3282 * does not include any capture framing headers. For example, an Ethernet
3283 * packet with an empty TCP packet will return sizeof(ethernet_header) +
3284 * sizeof(ip_header) + sizeof(tcp_header), but not the capture format
3285 * (pcap/erf/etc) header.
3286 */
3287DLLEXPORT SIMPLE_FUNCTION
3288size_t trace_get_capture_length(const libtrace_packet_t *packet);
3289
3290/** Get the size of the packet as it was originally seen on the wire (in bytes).
3291 * @param packet        The packet to determine the wire length for
3292 * @return The size of the packet as it was on the wire.
3293 *
3294 * @note This value may not be the same as the capture length, due to
3295 * truncation.
3296 *
3297 * @note trace_get_wire_length \em includes  the Frame Check Sequence. This is
3298 * different behaviour compared to most PCAP-based tools.
3299 *
3300 * @note The return size refers to the network-level payload of the packet and
3301 * does not include any capture framing headers. For example, an Ethernet
3302 * packet with an empty TCP packet will return sizeof(ethernet_header) +
3303 * sizeof(ip_header) + sizeof(tcp_header), but not the capture format
3304 * (pcap/erf/etc) header.
3305 */
3306DLLEXPORT SIMPLE_FUNCTION
3307size_t trace_get_wire_length(const libtrace_packet_t *packet);
3308
3309/** Get the length of the capture framing headers (in bytes).
3310 * @param packet        The packet to determine the framing length for
3311 * @return The size of the capture format header encapsulating the packet.
3312 *
3313 * @note This length corresponds to the difference between the amount of
3314 * memory required to store a captured packet and the capture length reported
3315 * by trace_capture_length()
3316 */
3317DLLEXPORT SIMPLE_FUNCTION
3318size_t trace_get_framing_length(const libtrace_packet_t *packet);
3319
3320/** Get the length of the original payload content of the packet (in bytes).
3321 * @param packet        The packet to determine the payload length for
3322 * @return The size of the packet payload (without headers). Returns 0 if
3323 * unable to calculate payload length correctly.
3324 *
3325 * This function reports the amount of data that followed the transport header
3326 * when the packet was originally captured, i.e. prior to any snapping. Best
3327 * described as the wire length minus the packet headers.
3328 *
3329 * Currently only supports some protocols and will return 0 if an unsupported
3330 * protocol header is encountered, or if one of the headers is truncated.
3331 *
3332 * @note Supports IPv4, IPv6, TCP, UDP and ICMP.
3333 */
3334DLLEXPORT SIMPLE_FUNCTION
3335size_t trace_get_payload_length(const libtrace_packet_t *packet);
3336
3337/** Truncate ("snap") the packet to the suggested length
3338 * @param packet        The packet to truncate
3339 * @param size          The new length of the packet (in bytes)
3340 *
3341 * @return The new capture length of the packet or the original capture
3342 * length of the packet if unchanged.
3343 *
3344 * This function will modify the capture length of the given packet. The wire
3345 * length will not be changed, so you can always determine what the original
3346 * packet size was, prior to the truncation.
3347 *
3348 * @note You can only use this function to decrease the capture length. Any
3349 * attempt to increase capture length will have no effect.
3350 */
3351DLLEXPORT size_t trace_set_capture_length(libtrace_packet_t *packet, size_t size);
3352
3353/*@}*/
3354
3355
3356/** Gets the link layer type for a packet
3357 * @param packet        The packet to extract the link layer type for
3358 * @return A libtrace_linktype_t describing the link layer protocol being used
3359 * by this packet.
3360 */
3361DLLEXPORT SIMPLE_FUNCTION
3362libtrace_linktype_t trace_get_link_type(const libtrace_packet_t *packet);
3363
3364/** Set the direction flag for a packet, if the capture format supports
3365 * direction tagging.
3366 *
3367 * @param packet        The packet to set the direction for
3368 * @param direction     The new direction
3369 * @returns -1 on error, or the direction that was set.
3370 *
3371 * @note Few capture formats actually support direction tagging. Most notably,
3372 * we cannot set the direction on PCAP packets.
3373 */
3374DLLEXPORT libtrace_direction_t trace_set_direction(libtrace_packet_t *packet, libtrace_direction_t direction);
3375
3376/** Get the direction flag for a packet, if it has one.
3377 * @param packet  The packet to get the direction for
3378 *
3379 * @return A value representing the direction flag, or -1 if this is not
3380 * supported by the capture format.
3381 *
3382 * The direction is defined as 0 for packets originating locally (ie, outbound)
3383 * and 1 for packets originating remotely (ie, inbound). Other values are
3384 * possible, which might be overloaded to mean special things for certain
3385 * traces, e.g. in the Waikato traces, 2 is used to represent an "Unknown"
3386 * direction.
3387 *
3388 * For DAG/ERF traces, the direction is extracted from the "Interface" bits in
3389 * the ERF header, which can range from 0 - 3.
3390 */
3391DLLEXPORT SIMPLE_FUNCTION
3392libtrace_direction_t trace_get_direction(const libtrace_packet_t *packet);
3393
3394/** @name BPF
3395 * This section deals with using Berkley Packet Filters to filter input traces
3396 * @{
3397 */
3398/** Creates a BPF filter
3399 * @param filterstring The filter string describing the BPF filter to create
3400 * @return An opaque pointer to a libtrace_filter_t object
3401 *
3402 * @note The filter is not actually compiled at this point, so no correctness
3403 * tests are performed here. trace_create_filter() will always return ok, but
3404 * if the filter is poorly constructed an error will be generated when the
3405 * filter is actually used.
3406 */
3407DLLEXPORT SIMPLE_FUNCTION
3408libtrace_filter_t *trace_create_filter(const char *filterstring);
3409
3410/** Create a BPF filter based on pre-compiled byte-code.
3411 * @param bf_insns      A pointer to the start of the byte-code
3412 * @param bf_len        The number of BPF instructions 
3413 * @return              An opaque pointer to a libtrace_filter_t object
3414 * @note                The supplied byte-code is not checked for correctness.
3415 *                      Instead, incorrect byte-code will generate an error
3416 *                      once the filter is actually used.
3417 * @author              Scott Raynel
3418 */
3419DLLEXPORT libtrace_filter_t *
3420trace_create_filter_from_bytecode(void *bf_insns, unsigned int bf_len);
3421
3422/** Apply a BPF filter to a packet
3423 * @param filter        The filter to be applied       
3424 * @param packet        The packet to be matched against the filter
3425 * @return >0 if the filter matches, 0 if it doesn't, -1 on error.
3426 *
3427 * @note Due to the way BPF filters are built, the filter is not actually
3428 * compiled until the first time trace_create_filter is called. If your filter
3429 * is incorrect, it will generate an error message and assert, exiting the
3430 * program. This behaviour may change to a more graceful handling of this error
3431 * in the future.
3432 */
3433DLLEXPORT int trace_apply_filter(libtrace_filter_t *filter,
3434                const libtrace_packet_t *packet);
3435
3436/** Destroy a BPF filter
3437 * @param filter        The filter to be destroyed
3438 *
3439 * Deallocates all the resources associated with a BPF filter.
3440 */
3441DLLEXPORT void trace_destroy_filter(libtrace_filter_t *filter);
3442/*@}*/
3443
3444/** @name Portability
3445 * This section contains functions that deal with portability issues, e.g. byte
3446 * ordering.
3447 * @{
3448 */
3449
3450/** Converts an ethernet address to a printable string
3451 * @param addr  Ethernet address in network byte order
3452 * @param buf   Buffer to store the ascii representation, or NULL to indicate
3453 * that static storage should be used.
3454 * @return buf, or if buf is NULL then a statically allocated buffer.
3455 *
3456 * This function is similar to the GNU ether_ntoa_r function, with a few
3457 * minor differences.  If NULL is passed as buf, then the function will
3458 * use an internal static buffer. If NULL isn't passed then the function
3459 * will use that buffer instead.
3460 *
3461 * The address pointers returned by trace_get_source_mac() and
3462 * trace_get_destination_mac() can be passed directly into this function.
3463 *
3464 * @note The type of addr isn't struct ether_addr as it is with ether_ntoa_r,
3465 * however it is bit compatible so that a cast will work.
3466 */
3467DLLEXPORT char *trace_ether_ntoa(const uint8_t *addr, char *buf);
3468
3469/** Convert a string to an ethernet address
3470 * @param buf   A string containing an Ethernet address in hex format
3471 * delimited with :'s.
3472 * @param addr  Buffer to store the binary representation, or NULL to indicate
3473 * that static storage should be used.
3474 * @return addr, or if addr is NULL then a statically allocated buffer.
3475 *
3476 * This function is similar to the GNU ether_aton_r function, with a few
3477 * minor differences.  If NULL is passed as addr, then the function will
3478 * use an internal static buffer. If NULL isn't passed then the function will
3479 * use that buffer instead.
3480 *
3481 * The address returned by this function will be in network byte order.
3482 *
3483 * @note the type of addr isn't struct ether_addr as it is with ether_aton_r,
3484 * however it is bit compatible so that a cast will work.
3485 */
3486DLLEXPORT uint8_t *trace_ether_aton(const char *buf, uint8_t *addr);
3487
3488/*@}*/
3489
3490/** @name Ports
3491 * This section contains functions for dealing with port numbers at the
3492 * transport layer.
3493 *
3494 * @{
3495 */
3496
3497/** An indication of which port is the "server" port for a given port pair */
3498typedef enum {
3499        USE_DEST,       /**< Destination port is the server port */
3500        USE_SOURCE      /**< Source port is the server port */
3501} serverport_t;
3502
3503/** Gets the source port for a given packet
3504 * @param packet        The packet to get the source port from
3505 * @return The source port in HOST byte order or 0 if no suitable port number
3506 * can be extracted from the packet.
3507 *
3508 * This function will return 0 if the transport protocol is known not to
3509 * use port numbers, e.g. ICMP. 0 is also returned if no transport header is
3510 * present in the packet or the transport header has been truncated such that
3511 * the port fields are not readable.
3512 *
3513 * @note If the transport protocol is not known by libtrace, the first two
3514 * bytes of the transport header will be treated as the source port field.
3515 */
3516DLLEXPORT SIMPLE_FUNCTION
3517uint16_t trace_get_source_port(const libtrace_packet_t *packet);
3518
3519/** Gets the destination port for a given packet
3520 * @param packet        The packet to get the destination port from
3521 * @return The destination port in HOST byte order or 0 if no suitable port
3522 * number can be extracted from the packet.
3523 *
3524 * This function will return 0 if the transport protocol is known not to
3525 * use port numbers, e.g. ICMP. 0 is also returned if no transport header is
3526 * present in the packet or the transport header has been truncated such that
3527 * the port fields are not readable.
3528 *
3529 * @note If the transport protocol is not known by libtrace, the third and
3530 * fourth bytes of the transport header will be treated as the destination
3531 * port field.
3532 *
3533 */
3534DLLEXPORT SIMPLE_FUNCTION
3535uint16_t trace_get_destination_port(const libtrace_packet_t *packet);
3536
3537/** Hint at which of the two provided ports is the server port.
3538 *
3539 * @param protocol      The IP layer protocol, eg 6 (tcp), 17 (udp)
3540 * @param source        The source port from the packet
3541 * @param dest          The destination port from the packet
3542 *
3543 * @return one of USE_SOURCE or USE_DEST describing on which of the two ports
3544 * is most likely to be the server port.
3545 *
3546 * @note Ports must be provided in HOST byte order!
3547 *
3548 * This function is based almost entirely on heuristics and should not be
3549 * treated as a definitive means of identifying the server port. However, it
3550 * is deterministic, so it is very handy for identifying both halves of the
3551 * same flow.
3552 */
3553DLLEXPORT SIMPLE_FUNCTION
3554int8_t trace_get_server_port(uint8_t protocol, uint16_t source, uint16_t dest);
3555
3556/*@}*/
3557
3558/** @name Wireless trace support
3559 * Functions to access wireless information from packets that have wireless
3560 * monitoring headers such as Radiotap or Prism.
3561 *
3562 * The trace_get_wireless_* functions provide an abstract interface for
3563 * retrieving information from wireless traces. They take a pointer to the
3564 * wireless monitoring header (usually found with trace_get_packet_meta()) and
3565 * the linktype of the header passed in.
3566 *
3567 * All of the trace_get_wireless_* functions return false if the requested
3568 * information was unavailable, or true if it was. The actual data is stored
3569 * in an output variable supplied by the caller. Values returned into the
3570 * output variable will always be returned in host byte order.
3571 * @{
3572 */
3573
3574
3575#ifndef ARPHRD_80211_RADIOTAP
3576/** libc doesn't define this yet, so we have to do so ourselves */
3577#define ARPHRD_80211_RADIOTAP 803
3578#endif
3579
3580/** Get the wireless Timer Synchronisation Function
3581 *
3582 * Gets the value of the timer synchronisation function for this frame, which
3583 * is a value in microseconds indicating the time that the first bit of the
3584 * MPDU was received by the MAC.
3585 *
3586 * @param linkptr The wireless meta header
3587 * @param linktype The linktype of the wireless meta header passed in
3588 * @param[out] tsft The value of the timer synchronisation function.
3589 * @return true if the field was available, false if not.
3590 */
3591DLLEXPORT bool trace_get_wireless_tsft(void *linkptr,
3592        libtrace_linktype_t linktype, uint64_t *tsft);
3593
3594/** Get the wireless data rate
3595 *
3596 * @param linkptr The wireless meta header
3597 * @param linktype The linktype of the wireless meta header passed in
3598 * @param[out] rate The data-rate of the frame in units of 500kbps
3599 * @return true if the field was available, false if not.
3600 */
3601DLLEXPORT bool trace_get_wireless_rate(void *linkptr,
3602        libtrace_linktype_t linktype, uint8_t *rate);
3603
3604/** Get the wireless channel frequency
3605 * @param linkptr The wireless meta header
3606 * @param linktype The linktype of the wireless meta header passed in
3607 * @param[out] freq The frequency in MHz of the channel the frame was
3608 * transmitted or received on.
3609 * @return true if the field was available, false if not.
3610 */
3611DLLEXPORT bool trace_get_wireless_freq(void *linkptr,
3612        libtrace_linktype_t linktype, uint16_t *freq);
3613
3614/** Get the wireless signal strength in dBm
3615 * @param linkptr The wireless meta header
3616 * @param linktype The linktype of the wireless meta header passed in
3617 * @param[out] strength The RF signal power at the antenna, in dB difference
3618 * from 1mW.
3619 * @return true if the field was available, false if not.
3620 */
3621DLLEXPORT bool trace_get_wireless_signal_strength_dbm(void *linkptr,
3622        libtrace_linktype_t linktype, int8_t *strength);
3623
3624/** Get the wireless noise strength in dBm
3625 * @param linkptr The wireless meta header
3626 * @param linktype The linktype of the wireless meta header passed in
3627 * @param[out] strength The RF noise power at the antenna, in dB difference
3628 * from 1mW.
3629 * @return true if the field was available, false if not.
3630 */
3631DLLEXPORT bool trace_get_wireless_noise_strength_dbm(void *linkptr,
3632        libtrace_linktype_t linktype, int8_t *strength);
3633
3634/** Get the wireless signal strength in dB
3635 * @param linkptr The wireless meta header
3636 * @param linktype The linktype of the wireless meta header passed in
3637 * @param[out] strength The RF signal power at the antenna, in dB difference
3638 * from a fixed reference.
3639 * @return true if the field was available, false if not.
3640 */
3641DLLEXPORT bool trace_get_wireless_signal_strength_db(void *linkptr,
3642        libtrace_linktype_t linktype, uint8_t *strength);
3643
3644/** Get the wireless noise strength in dB
3645 * @param linkptr The wireless meta header
3646 * @param linktype The linktype of the wireless meta header passed in
3647 * @param[out] strength The RF noise power at the antenna, in dB difference
3648 * from a fixed reference.
3649 * @return true if the field was available, false if not.
3650 */
3651DLLEXPORT bool trace_get_wireless_noise_strength_db(void *linkptr,
3652        libtrace_linktype_t linktype, uint8_t *strength);
3653
3654/** Get the wireless transmit attenuation
3655 * @param linkptr The wireless meta header
3656 * @param linktype The linktype of the wireless meta header passed in
3657 * @param[out] attenuation The transmit power as a unitless distance from
3658 * maximum power set at factory calibration. 0 indicates maximum transmission
3659 * power.
3660 * @return true if the field was available, false if not.
3661 */
3662DLLEXPORT bool trace_get_wireless_tx_attenuation(void *linkptr,
3663        libtrace_linktype_t linktype, uint16_t *attenuation);
3664
3665/** Get the wireless transmit attenuation in dB
3666 * @param linkptr The wireless meta header
3667 * @param linktype The linktype of the wireless meta header passed in
3668 * @param[out] attenuation The transmit power as dB difference from maximum
3669 * power set at factory calibration. 0 indicates maximum power.
3670 * @return true if the field was available, false if not.
3671 */
3672DLLEXPORT bool trace_get_wireless_tx_attenuation_db(void *linkptr,
3673        libtrace_linktype_t linktype, uint16_t *attenuation);
3674
3675/** Get the wireless transmit power in dBm
3676 * @param linkptr The wireless meta header
3677 * @param linktype The linktype of the wireless meta header passed in
3678 * @param[out] txpower The transmit power as dB from a 1mW reference. This is
3679 * the absolute power level measured at the antenna port. 
3680 * @return true if the field was available, false if not.
3681 */
3682DLLEXPORT bool trace_get_wireless_tx_power_dbm(void *linkptr,
3683                libtrace_linktype_t linktype, int8_t *txpower);
3684
3685/** Get the wireless antenna
3686 * @param linkptr The wireless meta header
3687 * @param linktype The linktype of the wireless meta header passed in
3688 * @param[out] antenna The antenna that was used to transmit or receive the
3689 * frame.
3690 * @return true if the field was available, false if not.
3691 */
3692DLLEXPORT bool trace_get_wireless_antenna(void *linkptr,
3693        libtrace_linktype_t linktype, uint8_t *antenna);
3694
3695/*@}*/
3696
3697#ifdef __cplusplus
3698} /* extern "C" */
3699#endif /* #ifdef __cplusplus */
3700#endif /* LIBTRACE_H_ */
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