source: lib/libtrace.h.in @ ed5b2ce

cachetimestampsdevelopdpdk-ndagetsilivendag_formatrc-4.0.2rc-4.0.3rc-4.0.4ringdecrementfixringperformance
Last change on this file since ed5b2ce was ed5b2ce, checked in by Shane Alcock <salcock@…>, 4 years ago

Add support for reading pcapng traces

Also added special macro: IS_LIBTRACE_META_PACKET()
This macro can be used to easily recognise if a "packet" is a
genuine packet record or a meta record (such as a pcapng interface
block or an RT control message).

  • Property mode set to 100644
File size: 143.2 KB
Line 
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[255];      /**< 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};
309
310/** Enumeration of DLTs supported by libtrace
311 */
312typedef enum {
313        /* Special value used to indicate a failure to convert to libtrace
314         * DLT */
315        TRACE_DLT_ERROR = -1,
316
317        /** pcap documents this as having the Address Family value in host
318          * byte order as the framing.  Ugly? Yes.
319          */
320        TRACE_DLT_NULL = 0,
321        TRACE_DLT_EN10MB = 1,
322        TRACE_DLT_PPP = 9,
323        TRACE_DLT_ATM_RFC1483 = 11,
324
325        /** Ok, so OpenBSD has a different value for DLT_RAW as the rest of
326         * the planet, so detect this.  When reading to/from files we should
327         * be using TRACE_DLT_LINKTYPE_RAW instead. When talking about DLT's
328         * inside libtrace tho, we should be using /these/ DLT's.
329         */
330#ifdef __OpenBSD__
331        TRACE_DLT_OPENBSD_LOOP=12,
332        TRACE_DLT_RAW = 14
333#else
334        TRACE_DLT_RAW = 12,
335        TRACE_DLT_OPENBSD_LOOP = 108,
336#endif
337        TRACE_DLT_PPP_SERIAL = 50,
338        TRACE_DLT_LINKTYPE_RAW = 101, /**< See TRACE_DLT_RAW for explanations of pain. */
339        TRACE_DLT_C_HDLC = 104,
340        TRACE_DLT_IEEE802_11 = 105,
341        TRACE_DLT_LINUX_SLL = 113,
342        TRACE_DLT_PFLOG = 117,
343        TRACE_DLT_IEEE802_11_RADIO = 127 /**< Radiotap */
344} libtrace_dlt_t ;
345
346/** Enumeration of link layer types supported by libtrace */
347typedef enum {
348       TRACE_TYPE_UNKNOWN = -1,         /**< Unable to determine link type */
349    /* TRACE_TYPE_LEGACY = 0            Obsolete */
350       TRACE_TYPE_HDLC_POS = 1,         /**< HDLC over POS */
351       TRACE_TYPE_ETH = 2,              /**< 802.3 style Ethernet */
352       TRACE_TYPE_ATM = 3,              /**< ATM frame */
353       TRACE_TYPE_80211 = 4,            /**< 802.11 frames */
354       TRACE_TYPE_NONE = 5,             /**< Raw IP frames */
355       TRACE_TYPE_LINUX_SLL = 6,        /**< Linux "null" framing */
356       TRACE_TYPE_PFLOG = 7,            /**< FreeBSD's PFlog */
357    /* TRACE_TYPE_LEGACY_DEFAULT        Obsolete */
358       TRACE_TYPE_POS = 9,              /**< Packet-over-SONET */
359    /* TRACE_TYPE_LEGACY_ATM            Obsolete */
360    /* TRACE_TYPE_LEGACY_ETH            Obsolete */
361       TRACE_TYPE_80211_PRISM = 12,     /**< 802.11 Prism frames */
362       TRACE_TYPE_AAL5 = 13,            /**< ATM Adaptation Layer 5 frames */
363       TRACE_TYPE_DUCK = 14,         /**< Pseudo link layer for DUCK packets */
364       TRACE_TYPE_80211_RADIO = 15,  /**< Radiotap + 802.11 */
365       TRACE_TYPE_LLCSNAP = 16,      /**< Raw LLC/SNAP */
366       TRACE_TYPE_PPP = 17,          /**< PPP frames */
367       TRACE_TYPE_METADATA = 18,        /**< WDCAP-style meta-data */
368       TRACE_TYPE_NONDATA = 19,         /**< Not a data packet */
369       TRACE_TYPE_OPENBSD_LOOP = 20     /**< OpenBSD loopback */
370} libtrace_linktype_t;
371
372/** RT protocol base format identifiers.
373 * This is used to describe the capture format of the packet is being sent
374 * using the RT protocol.
375 */
376enum base_format_t {
377        TRACE_FORMAT_ERF          =1,   /**< ERF (DAG capture format) */
378        TRACE_FORMAT_PCAP         =2,   /**< Live PCAP capture */
379        TRACE_FORMAT_PCAPFILE     =3,   /**< PCAP trace file */
380        TRACE_FORMAT_WAG          =4,   /**< WAG live capture (Obsolete) */
381        TRACE_FORMAT_RT           =5,   /**< RT network protocol */
382        TRACE_FORMAT_LEGACY_ATM   =6,   /**< Legacy ERF for ATM capture */
383        TRACE_FORMAT_LEGACY_POS   =7,   /**< Legacy ERF for POS capture */
384        TRACE_FORMAT_LEGACY_ETH   =8,   /**< Legacy ERF for ETH capture */
385        TRACE_FORMAT_LINUX_NATIVE =9,   /**< Linux native interface capture */
386        TRACE_FORMAT_DUCK         =10,  /**< DAG Clock information */
387        TRACE_FORMAT_BPF          =11,  /**< BSD native interface capture */
388        TRACE_FORMAT_TSH          =12,  /**< TSH trace format */
389        TRACE_FORMAT_ATMHDR       =13,  /**< Legacy ATM header capture */
390        TRACE_FORMAT_LEGACY_NZIX  =14,  /**< Legacy format used for NZIX traces */
391        TRACE_FORMAT_LINUX_RING   =15,  /**< Linux native interface capture PACKET_MMAP */
392        TRACE_FORMAT_RAWERF       =16,  /**< Special format for reading uncompressed ERF traces without checking for compression */
393        TRACE_FORMAT_DPDK     =17, /**< The Intel Data Plane Development Kit format */
394        TRACE_FORMAT_PCAPNG     =18,    /**< PCAP-NG trace file */
395};
396
397/** RT protocol packet types */
398typedef enum {
399        TRACE_RT_HELLO          =1, /**< Connection accepted */
400        TRACE_RT_START          =2, /**< Request for data transmission to begin
401                                    */
402        TRACE_RT_ACK            =3, /**< Data acknowledgement */
403        TRACE_RT_STATUS         =4, /**< Fifo status packet */
404        TRACE_RT_DUCK           =5, /**< Dag duck info packet */
405        TRACE_RT_END_DATA       =6, /**< Server is exiting message */
406        TRACE_RT_CLOSE          =7, /**< Client is exiting message */
407        TRACE_RT_DENY_CONN      =8, /**< Connection has been denied */
408        TRACE_RT_PAUSE          =9, /**< Request server to suspend sending data
409                                     */
410        TRACE_RT_PAUSE_ACK      =10,/**< Server is paused message */
411        TRACE_RT_OPTION         =11,/**< Option request */
412        TRACE_RT_KEYCHANGE      =12,/**< Anonymisation key has changed */
413        TRACE_RT_DUCK_2_4       =13,/**< Dag 2.4 Duck */
414        TRACE_RT_DUCK_2_5       =14,/**< Dag 2.5 Duck */
415        TRACE_RT_LOSTCONN       =15,/**< Lost connection to server */
416        TRACE_RT_SERVERSTART    =16,/**< Reliable server has been restarted */
417        TRACE_RT_CLIENTDROP     =17,/**< Reliable client was lost */
418        TRACE_RT_METADATA       =18,/**< Packet contains server meta-data */
419        TRACE_RT_DUCK_5_0       =19,/**< Dag 5.0 Duck */
420        TRACE_RT_PCAPNG_META    =20,/**< Metadata for a PCAP NG input source */
421
422        /** Not actually used - all DATA types begin from this value */
423        TRACE_RT_DATA_SIMPLE    = 1000,
424       
425        /** RT is encapsulating an ERF capture record */
426        TRACE_RT_DATA_ERF       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_ERF,
427        /** RT is encapsulating a WAG capture record */
428        TRACE_RT_DATA_WAG       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_WAG,
429        /** RT is encapsulating a Legacy ATM capture record */
430        TRACE_RT_DATA_LEGACY_ATM=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_ATM,
431        /** RT is encapsulating a Legacy POS capture record */
432        TRACE_RT_DATA_LEGACY_POS=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_POS,
433        /** RT is encapsulating a Legacy ETH capture record */
434        TRACE_RT_DATA_LEGACY_ETH=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_ETH,
435        /** RT is encapsulating a Linux native capture record */
436        TRACE_RT_DATA_LINUX_NATIVE=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LINUX_NATIVE,
437        /** RT is encapsulating a BSD native capture record */
438        //TRACE_RT_DATA_BPF       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_BPF,
439        /** RT is encapsulating a TSH capture record */
440        TRACE_RT_DATA_TSH       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_TSH,
441        /** RT is encapsulating an ATM header capture record */
442        TRACE_RT_DATA_ATMHDR = TRACE_RT_DATA_SIMPLE + TRACE_FORMAT_ATMHDR,
443        /** RT is encapsulating a Legacy NZIX capture record */
444        TRACE_RT_DATA_LEGACY_NZIX=TRACE_RT_DATA_SIMPLE + TRACE_FORMAT_LEGACY_NZIX,
445        /** RT is encapsulating a Linux native PACKET_MMAP capture record */
446        TRACE_RT_DATA_LINUX_RING=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LINUX_RING,
447    /** RT is encapsulating a Intel DPDK capture record */
448        TRACE_RT_DATA_DPDK=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_DPDK,
449
450        /** As PCAP does not store the linktype with the packet, we need to
451         * create a separate RT type for each supported DLT, starting from
452         * this value */
453        TRACE_RT_DATA_DLT               = 2000,
454        /** RT is encapsulating a PCAP capture record with a NULL linktype */
455        TRACE_RT_DLT_NULL               =TRACE_RT_DATA_DLT+TRACE_DLT_NULL,
456        /** RT is encapsulating a PCAP capture record with an Ethernet
457         * linktype */
458        TRACE_RT_DLT_EN10MB             =TRACE_RT_DATA_DLT+TRACE_DLT_EN10MB,
459        /** RT is encapsulating a PCAP capture record with an 802.11
460         * linktype */
461        TRACE_RT_DLT_IEEE802_11         =TRACE_RT_DATA_DLT+TRACE_DLT_IEEE802_11,
462        /** RT is encapsulating a PCAP capture record with a Linux SLL
463         * linktype */
464        TRACE_RT_DLT_LINUX_SLL          =TRACE_RT_DATA_DLT+TRACE_DLT_LINUX_SLL,
465        /** RT is encapsulating a PCAP capture record with a PFlog linktype */
466        TRACE_RT_DLT_PFLOG              =TRACE_RT_DATA_DLT+TRACE_DLT_PFLOG,
467        /** RT is encapsulating a PCAP capture record with an AAL5 linktype */
468        TRACE_RT_DLT_ATM_RFC1483        =TRACE_RT_DATA_DLT+TRACE_DLT_ATM_RFC1483,
469        /** Unused value marking the end of the valid range for PCAP RT
470         * encapsulation */
471        TRACE_RT_DATA_DLT_END           = 2999,
472        /** BPF does not store the linktype with the packet, so we need a
473         * separate RT type for each supported DLT. This value represents the
474         * starting point */
475        TRACE_RT_DATA_BPF               = 3000,
476
477        TRACE_RT_BPF_NULL               = TRACE_RT_DATA_BPF+TRACE_DLT_NULL,
478        TRACE_RT_BPF_EN10MB             = TRACE_RT_DATA_BPF+TRACE_DLT_EN10MB,
479        TRACE_RT_BPF_IEEE802_11         = TRACE_RT_DATA_BPF+TRACE_DLT_IEEE802_11,
480        TRACE_RT_BPF_PFLOG              =TRACE_RT_DATA_BPF+TRACE_DLT_PFLOG,
481        TRACE_RT_BPF_ATM_RFC1483        =TRACE_RT_DATA_BPF+TRACE_DLT_ATM_RFC1483,
482
483        TRACE_RT_DATA_BPF_END           = 3999,
484
485        TRACE_RT_DATA_PCAPNG            = 4000,
486        TRACE_RT_DATA_PCAPNG_END        = 4499,
487        /** Unused value marking the end of the valid range for all RT packet
488         * types */
489        TRACE_RT_LAST                   = 4500
490} libtrace_rt_types_t;
491
492/** IP Protocol values */
493typedef enum {
494        TRACE_IPPROTO_IP        = 0,    /**< IP pseudo protocol number */
495        TRACE_IPPROTO_ICMP      = 1,    /**< Internet Control Message protocol */
496        TRACE_IPPROTO_IGMP      = 2,    /**< Internet Group Management Protocol */
497        TRACE_IPPROTO_IPIP      = 4,    /**< IP encapsulated in IP */
498        TRACE_IPPROTO_TCP       = 6,    /**< Transmission Control Protocol */
499        TRACE_IPPROTO_UDP       = 17,   /**< User Datagram Protocol */
500        TRACE_IPPROTO_IPV6      = 41,   /**< IPv6 over IPv4 */
501        TRACE_IPPROTO_ROUTING   = 43,   /**< IPv6 Routing header */
502        TRACE_IPPROTO_FRAGMENT  = 44,   /**< IPv6 Fragmentation header */
503        TRACE_IPPROTO_RSVP      = 46,   /**< Resource Reservation Protocol */
504        TRACE_IPPROTO_GRE       = 47,   /**< General Routing Encapsulation */
505        TRACE_IPPROTO_ESP       = 50,   /**< Encapsulated Security Payload [RFC2406] */
506        TRACE_IPPROTO_AH        = 51,   /**< Authentication Header [RFC2402] */
507        TRACE_IPPROTO_ICMPV6    = 58,   /**< ICMPv6 */
508        TRACE_IPPROTO_NONE      = 59,   /**< IPv6 no next header */
509        TRACE_IPPROTO_DSTOPTS   = 60,   /**< IPv6 destination options */
510        TRACE_IPPROTO_OSPF      = 89,   /**< Open Shortest Path First routing protocol */
511        TRACE_IPPROTO_PIM       = 103,  /**< Protocol Independant Multicast */
512        TRACE_IPPROTO_SCTP      = 132   /**< Stream Control Transmission Protocol */
513} libtrace_ipproto_t;
514
515/** Ethertypes supported by Libtrace */
516typedef enum {
517        /* Numbers <=1500 are of course, LLC/SNAP */
518        TRACE_ETHERTYPE_LOOPBACK= 0x0060,       /**< Ethernet Loopback */
519        TRACE_ETHERTYPE_IP      = 0x0800,       /**< IPv4 */
520        TRACE_ETHERTYPE_ARP     = 0x0806,       /**< Address resolution protocol */
521        TRACE_ETHERTYPE_RARP    = 0x8035,       /**< Reverse ARP */
522        TRACE_ETHERTYPE_8021Q   = 0x8100,       /**< 802.1q VLAN Extended Header */
523        TRACE_ETHERTYPE_IPV6    = 0x86DD,       /**< IPv6 */
524        TRACE_ETHERTYPE_MPLS    = 0x8847,       /**< MPLS Unicast traffic */
525        TRACE_ETHERTYPE_MPLS_MC = 0x8848,       /**< MPLS Multicast traffic */
526        TRACE_ETHERTYPE_PPP_DISC= 0x8863,       /**< PPPoE Service Discovery */
527        TRACE_ETHERTYPE_PPP_SES = 0x8864        /**< PPPoE Session Messages */
528} libtrace_ethertype_t;
529
530/** The libtrace packet structure. Applications shouldn't be
531 * meddling around in here
532 */
533typedef struct libtrace_packet_t {
534        struct libtrace_t *trace;       /**< Pointer to the trace */
535        void *header;                   /**< Pointer to the framing header */
536        void *payload;                  /**< Pointer to the link layer */
537        void *buffer;                   /**< Allocated buffer */
538        libtrace_rt_types_t  type;      /**< RT protocol type for the packet */
539        buf_control_t buf_control;      /**< Describes memory ownership */
540        int capture_length;             /**< Cached capture length */
541        int wire_length;                /**< Cached wire length */
542        int payload_length;             /**< Cached payload length */
543        void *l2_header;                /**< Cached link header */
544        libtrace_linktype_t link_type;  /**< Cached link type */
545        uint32_t l2_remaining;          /**< Cached link remaining */
546        void *l3_header;                /**< Cached l3 header */
547        uint16_t l3_ethertype;          /**< Cached l3 ethertype */
548        uint32_t l3_remaining;          /**< Cached l3 remaining */
549        void *l4_header;                /**< Cached transport header */
550        uint8_t transport_proto;        /**< Cached transport protocol */
551        uint32_t l4_remaining;          /**< Cached transport remaining */
552        uint64_t order; /**< Notes the order of this packet in relation to the input */
553        uint64_t hash; /**< A hash of the packet as supplied by the user */
554        int error; /**< The error status of pread_packet */
555        uint64_t internalid;            /** Internal identifier for the pkt */
556        void *srcbucket;
557} libtrace_packet_t;
558
559#define IS_LIBTRACE_META_PACKET(packet) (packet->type < TRACE_RT_DATA_SIMPLE)
560
561
562/** Trace directions.
563 * Note that these are the directions used by convention. More directions
564 * are possible, not just these 3, and that they may not conform to this
565 * convention.
566 */
567typedef enum {
568        TRACE_DIR_OUTGOING = 0,         /**< Packets originating "inside" */
569        TRACE_DIR_INCOMING = 1,         /**< Packets originating "outside" */
570        TRACE_DIR_OTHER    = 2,         /**< Packets with an unknown direction, or one that's unknown */
571        TRACE_DIR_UNKNOWN = -1,         /**< No direction information available */
572} libtrace_direction_t;
573
574/** Enumeration of Radiotap fields */
575typedef enum {
576    TRACE_RADIOTAP_TSFT = 0, /**< Timer synchronisation function, in microseconds (uint64) */
577    TRACE_RADIOTAP_FLAGS = 1, /**< Wireless flags (uint8) */
578    TRACE_RADIOTAP_RATE = 2, /**< Bitrate in units of 500kbps (uint8) */
579    TRACE_RADIOTAP_CHANNEL = 3, /**< Frequency in MHz (uint16) and channel flags (uint16) */
580    TRACE_RADIOTAP_FHSS = 4, /**< FHSS hop set (uint8) and hopping pattern (uint8) */
581    TRACE_RADIOTAP_DBM_ANTSIGNAL = 5, /**< Signal power in dBm (int8) */
582    TRACE_RADIOTAP_DBM_ANTNOISE = 6, /**< Noise power in dBm (int8) */
583    TRACE_RADIOTAP_LOCK_QUALITY = 7, /**< Barker Code lock quality (uint16) */
584    TRACE_RADIOTAP_TX_ATTENUATION = 8, /**< TX attenuation as unitless distance from max power (uint16) */
585    TRACE_RADIOTAP_DB_TX_ATTENUATION = 9, /**< TX attenuation as dB from max power (uint16) */
586    TRACE_RADIOTAP_DBM_TX_POWER = 10, /**< TX Power in dBm (int8) */
587    TRACE_RADIOTAP_ANTENNA = 11, /**< Antenna frame was rx'd or tx'd on (uint8) */
588    TRACE_RADIOTAP_DB_ANTSIGNAL = 12, /**< Signal power in dB from a fixed reference (uint8) */
589    TRACE_RADIOTAP_DB_ANTNOISE = 13, /**< Noise power in dB from a fixed reference (uint8) */
590    TRACE_RADIOTAP_RX_FLAGS = 14, /** Properties of received frame (uint16) */
591    TRACE_RADIOTAP_TX_FLAGS = 15, /** Properties of transmitted frame (uint16) */
592    TRACE_RADIOTAP_RTS_RETRIES = 16, /** Number of rts retries frame used (uint8) */
593    TRACE_RADIOTAP_DATA_RETRIES = 17, /** Number of unicast retries a transmitted frame used (uint8) */
594    TRACE_RADIOTAP_EXT = 31
595} libtrace_radiotap_field_t;
596
597
598/** @name Protocol structures
599 * These convenience structures provide portable versions of the headers
600 * for a variety of protocols.
601 * @{
602 */
603
604#ifdef WIN32
605#pragma pack(push)
606#pragma pack(1)
607#endif
608
609/** Generic IP header structure */
610typedef struct libtrace_ip
611{
612#if __BYTE_ORDER == __LITTLE_ENDIAN
613    LT_BITFIELD8 ip_hl:4;               /**< Header Length */
614    LT_BITFIELD8 ip_v:4;                /**< Version */
615#elif __BYTE_ORDER == __BIG_ENDIAN
616    LT_BITFIELD8 ip_v:4;                /**< Version */
617    LT_BITFIELD8 ip_hl:4;               /**< Header Length */
618#else
619#   error "Adjust your <bits/endian.h> defines"
620#endif
621    uint8_t  ip_tos;                    /**< Type of Service */
622    uint16_t ip_len;                    /**< Total Length */
623    int16_t  ip_id;                     /**< Identification */
624    uint16_t ip_off;                    /**< IP Fragment offset (and flags) */
625    uint8_t  ip_ttl;                    /**< Time to Live */
626    uint8_t  ip_p;                      /**< Protocol */
627    uint16_t ip_sum;                    /**< Checksum */
628    struct in_addr ip_src;              /**< Source Address */
629    struct in_addr ip_dst;              /**< Destination Address */
630} PACKED libtrace_ip_t;
631
632/** IPv6 header extension structure */
633typedef struct libtrace_ip6_ext
634{
635        uint8_t nxt;    /**< Next header */
636        uint8_t len;    /**< Length of the current header */
637} PACKED libtrace_ip6_ext_t;
638
639/** IPv6 fragmentation header */
640typedef struct libtrace_ip6_frag
641{
642        uint8_t nxt;    /**< Next header */
643        uint8_t res;    /**< Reserved */
644        uint16_t frag_off;      /**< Fragment Offset (includes M flag) */
645        uint32_t ident; /** Fragment identification */
646} PACKED libtrace_ip6_frag_t;
647
648/** Generic IPv6 header structure
649 *
650 * @note The flow label field also includes the Version and Traffic Class
651 * fields, because we haven't figured out a nice way to deal with fields
652 * crossing byte boundaries on both Big and Little Endian machines */
653typedef struct libtrace_ip6
654{
655    uint32_t flow;                      /**< Flow label */
656    uint16_t plen;                      /**< Payload length */
657    uint8_t nxt;                        /**< Next header */
658    uint8_t hlim;                       /**< Hop limit */
659    struct in6_addr ip_src;             /**< Source address */
660    struct in6_addr ip_dst;             /**< Destination address */
661} PACKED libtrace_ip6_t;
662
663/** Generic TCP header structure */
664typedef struct libtrace_tcp
665  {
666    uint16_t source;            /**< Source Port */
667    uint16_t dest;              /**< Destination port */
668    uint32_t seq;               /**< Sequence number */
669    uint32_t ack_seq;           /**< Acknowledgement Number */
670#  if __BYTE_ORDER == __LITTLE_ENDIAN
671    LT_BITFIELD8 ecn_ns:1;      /**< ECN Nonce Sum */
672    LT_BITFIELD8 res1:3;        /**< Reserved bits */
673    LT_BITFIELD8 doff:4;        /**< Data Offset */
674    LT_BITFIELD8 fin:1;         /**< FIN */
675    LT_BITFIELD8 syn:1;         /**< SYN flag */
676    LT_BITFIELD8 rst:1;         /**< RST flag */
677    LT_BITFIELD8 psh:1;         /**< PuSH flag */
678    LT_BITFIELD8 ack:1;         /**< ACK flag */
679    LT_BITFIELD8 urg:1;         /**< URG flag */
680    LT_BITFIELD8 ece:1;         /**< ECN Echo */
681    LT_BITFIELD8 cwr:1;         /**< ECN CWR */
682#  elif __BYTE_ORDER == __BIG_ENDIAN
683    LT_BITFIELD8 doff:4;        /**< Data offset */
684    LT_BITFIELD8 res1:3;        /**< Reserved bits */
685    LT_BITFIELD8 ecn_ns:1;      /**< ECN Nonce Sum */
686    LT_BITFIELD8 cwr:1;         /**< ECN CWR */
687    LT_BITFIELD8 ece:1;         /**< ECN Echo */
688    LT_BITFIELD8 urg:1;         /**< URG flag */
689    LT_BITFIELD8 ack:1;         /**< ACK flag */
690    LT_BITFIELD8 psh:1;         /**< PuSH flag */
691    LT_BITFIELD8 rst:1;         /**< RST flag */
692    LT_BITFIELD8 syn:1;         /**< SYN flag */
693    LT_BITFIELD8 fin:1;         /**< FIN flag */
694#  else
695#   error "Adjust your <bits/endian.h> defines"
696#  endif
697    uint16_t window;            /**< Window Size */
698    uint16_t check;             /**< Checksum */
699    uint16_t urg_ptr;           /**< Urgent Pointer */
700} PACKED libtrace_tcp_t;
701
702/** Generic UDP header structure */
703typedef struct libtrace_udp {
704  uint16_t      source;         /**< Source port */
705  uint16_t      dest;           /**< Destination port */
706  uint16_t      len;            /**< Length */
707  uint16_t      check;          /**< Checksum */
708} PACKED libtrace_udp_t;
709
710/** Generic ICMP header structure */
711typedef struct libtrace_icmp
712{
713  uint8_t type;         /**< Message Type */
714  uint8_t code;         /**< Type Sub-code */
715  uint16_t checksum;            /**< Checksum */
716  union
717  {
718    struct
719    {
720      uint16_t  id;             /**< ID of the Echo request */
721      uint16_t  sequence;       /**< Sequence number of the Echo request */
722    } echo;                     /**< Echo Datagram */
723    uint32_t    gateway;        /**< Gateway Address */
724    struct
725    {
726      uint16_t  unused;         /**< Unused */
727      uint16_t  mtu;            /**< Next-hop MTU */
728    } frag;                     /**< Path MTU Discovery */
729  } un;                         /**< Union for Payloads of Various ICMP Codes */
730} PACKED libtrace_icmp_t;
731
732/** Generic ICMPv6 header structure */
733typedef struct libtrace_icmp6 {
734  uint8_t type;         /**< Message Type */
735  uint8_t code;         /**< Type Sub-code */
736  uint16_t checksum;    /**< Checksum */
737
738  union {
739    struct {
740        uint8_t length;   /**< Length of original datagram content in 64 bit words */
741        uint8_t unused;   /**< Unused */       
742        uint8_t unused1;  /**< Unused */
743    } extend;   /**< Extensions added in RFC 4884 for Time Exceeded and Destination Unreachable Messages */
744
745    uint32_t mtu;       /**< MTU from Packet Too Big Message */
746    uint32_t pointer;   /**< Pointer from Parameter Problem Message */
747    struct {
748        uint16_t id;    /**< Echo Identifier */
749        uint16_t sequence; /**< Echo Sequence Number */
750    } echo; /**< Data required for Echo Request and Reply messages */
751  } un;
752} PACKED libtrace_icmp6_t;
753
754/** Generic LLC/SNAP header structure */
755typedef struct libtrace_llcsnap
756{
757/* LLC */
758  uint8_t dsap;                 /**< Destination Service Access Point */
759  uint8_t ssap;                 /**< Source Service Access Point */
760  uint8_t control;              /**< Control field */
761/* SNAP */
762  LT_BITFIELD32 oui:24;         /**< Organisationally Unique Identifier (scope)*/
763  uint16_t type;                /**< Protocol within OUI */
764} PACKED libtrace_llcsnap_t;
765
766/** 802.3 frame */
767typedef struct libtrace_ether
768{
769  uint8_t ether_dhost[6];       /**< Destination Ether Addr */
770  uint8_t ether_shost[6];       /**< Source Ether Addr */
771  uint16_t ether_type;          /**< Packet Type ID Field (next-header) */
772} PACKED libtrace_ether_t;
773
774/** 802.1Q frame */
775typedef struct libtrace_8021q
776{
777  LT_BITFIELD16 vlan_pri:3;      /**< VLAN User Priority */
778  LT_BITFIELD16 vlan_cfi:1;      /**< VLAN Format Indicator,
779                                   * 0 for ethernet, 1 for token ring */
780  LT_BITFIELD16 vlan_id:12;      /**< VLAN Id */
781  uint16_t vlan_ether_type;      /**< VLAN Sub-packet Type ID Field
782                                   * (next-header)*/
783} PACKED libtrace_8021q_t;
784
785/** ATM User Network Interface (UNI) Cell. */
786typedef struct libtrace_atm_cell
787{
788  LT_BITFIELD32 gfc:4;          /**< Generic Flow Control */
789  LT_BITFIELD32 vpi:8;          /**< Virtual Path Identifier */
790  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
791  LT_BITFIELD32 pt:3;           /**< Payload Type */
792  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
793  LT_BITFIELD32 hec:8;          /**< Header Error Control */
794} PACKED libtrace_atm_cell_t;
795
796/** ATM Network Node/Network Interface (NNI) Cell. */
797typedef struct libtrace_atm_nni_cell
798{
799  LT_BITFIELD32 vpi:12;         /**< Virtual Path Identifier */
800  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
801  LT_BITFIELD32 pt:3;           /**< Payload Type */
802  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
803  LT_BITFIELD32 hec:8;          /**< Header Error Control */
804} PACKED libtrace_atm_nni_cell_t;
805
806/** Captured UNI cell.
807 *
808 * Endace don't capture the HEC, presumably to keep alignment.  This
809 * version of the \ref libtrace_atm_cell is used when dealing with DAG
810 * captures of uni cells.
811 *
812 */
813typedef struct libtrace_atm_capture_cell
814{
815  LT_BITFIELD32 gfc:4;          /**< Generic Flow Control */
816  LT_BITFIELD32 vpi:8;          /**< Virtual Path Identifier */
817  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
818  LT_BITFIELD32 pt:3;           /**< Payload Type */
819  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
820} PACKED libtrace_atm_capture_cell_t;
821
822/** Captured NNI cell.
823 *
824 * Endace don't capture the HEC, presumably to keep alignment.  This
825 * version of the \ref libtrace_atm_nni_cell is used when dealing with DAG
826 * captures of nni cells.
827 *
828 */
829typedef struct libtrace_atm_nni_capture_cell
830{
831  LT_BITFIELD32 vpi:12;         /**< Virtual Path Identifier */
832  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
833  LT_BITFIELD32 pt:3;           /**< Payload Type */
834  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
835  LT_BITFIELD32 hec:8;          /**< Header Error Control */
836} PACKED libtrace_atm_nni_capture_cell_t;
837
838/** PPP header */
839typedef struct libtrace_ppp
840{
841 /* I can't figure out where the hell these two variables come from. They're
842  * definitely not in RFC 1661 which defines PPP. Probably some weird thing
843  * relating to the lack of distinction between PPP, HDLC and CHDLC */
844       
845/* uint8_t address; */          /**< PPP Address (0xFF - All stations) */
846/* uint8_t header;  */          /**< PPP Control (0x03 - Unnumbered info) */
847 uint16_t protocol;             /**< PPP Protocol (htons(0x0021) - IPv4 */
848} PACKED libtrace_ppp_t;
849
850/** PPPoE header */
851typedef struct libtrace_pppoe
852{
853 LT_BITFIELD8 version:4;        /**< Protocol version number */
854 LT_BITFIELD8 type:4;           /**< PPPoE Type */
855 uint8_t code;                  /**< PPPoE Code */
856 uint16_t session_id;           /**< Session Identifier */
857 uint16_t length;               /**< Total Length of the PPP packet */
858} PACKED libtrace_pppoe_t;
859
860/** Libtrace local definition of GRE (Generalised Routing Protocol) header
861 * RFC2890
862 */
863typedef struct libtrace_gre_t
864{
865    uint16_t flags;         /**< Flags and version */
866    uint16_t ethertype;     /**< Payload ethertype */
867    uint16_t checksum;      /**< Optional checksum */
868    uint16_t reserved1;     /**< Optional reserved */
869    uint16_t key;           /**< Optional key (or Tenant Network ID) */
870    uint16_t seq;           /**< Optional sequence number */
871} PACKED libtrace_gre_t;
872
873#define LIBTRACE_GRE_FLAG_CHECKSUM 0x8000
874#define LIBTRACE_GRE_FLAG_KEY      0x2000
875#define LIBTRACE_GRE_FLAG_SEQ      0x1000
876#define LIBTRACE_GRE_FLAG_VERMASK  0x0007
877
878
879/* PPTP GRE (RFC2637) */
880#define LIBTRACE_GRE_FLAG_ACK      0x0080
881#define LIBTRACE_GRE_PPTP_VERSION  0x0001
882
883/** Libtrace local definition of VXLAN Header
884 * (draft-mahalingam-dutt-dcops-vxlan)
885 */
886typedef struct libtrace_vxlan_t
887{
888    uint8_t flags;          /**< Flags */
889    uint8_t reserved1[3];   /**< Reserved */
890    uint8_t vni[3];         /**< VXLAN Network Identifier (VNI) */
891    uint8_t reserved2;
892} PACKED libtrace_vxlan_t;
893
894/** 802.11 header */
895typedef struct libtrace_80211_t {
896#if __BYTE_ORDER == __LITTLE_ENDIAN
897        LT_BITFIELD32      protocol:2;  /**< Protocol Version */
898        LT_BITFIELD32      type:2;      /**< Frame Type */
899        LT_BITFIELD32      subtype:4;   /**< Frame Subtype */
900#else
901        LT_BITFIELD32      subtype:4;   /**< Frame Subtype */
902        LT_BITFIELD32      type:2;      /**< Frame Type */
903        LT_BITFIELD32      protocol:2;  /**< Protocol Version */
904#endif
905
906#if __BYTE_ORDER == __LITTLE_ENDIAN
907        LT_BITFIELD32      to_ds:1;     /**< Packet to Distribution Service */
908        LT_BITFIELD32      from_ds:1;   /**< Packet from Distribution Service */
909        LT_BITFIELD32      more_frag:1; /**< Packet has more fragments */
910        LT_BITFIELD32      retry:1;     /**< Packet is a retry */
911        LT_BITFIELD32      power:1;     /**< Power Management mode */
912        LT_BITFIELD32      more_data:1; /**< More data is buffered at station */
913        LT_BITFIELD32      wep:1;       /**< WEP encryption indicator */
914        LT_BITFIELD32      order:1;     /**< Strictly-Ordered class indicator */
915#else
916        LT_BITFIELD32      order:1;     /**< Strictly-Ordered class indicator */
917        LT_BITFIELD32      wep:1;       /**< WEP encryption indicator */
918        LT_BITFIELD32      more_data:1; /**< More data is buffered at station */
919        LT_BITFIELD32      power:1;     /**< Power Management mode */
920        LT_BITFIELD32      retry:1;     /**< Packet is a retry */
921        LT_BITFIELD32      more_frag:1; /**< Packet has more fragments */
922        LT_BITFIELD32      from_ds:1;   /**< Packet from Distribution Service */
923        LT_BITFIELD32      to_ds:1;     /**< Packet to Distribution Service */
924#endif
925       
926        uint16_t     duration;  /**< Duration value for NAV calculation */
927        uint8_t      mac1[6];   /**< MAC Address 1 */
928        uint8_t      mac2[6];   /**< MAC Address 2 */
929        uint8_t      mac3[6];   /**< MAC Address 3 */
930        uint16_t     SeqCtl;    /**< Sequence Control */       
931        uint8_t      mac4[6];   /**< MAC Address 4 */
932} PACKED libtrace_80211_t;
933
934/** The Radiotap header pre-amble
935 *
936 * All Radiotap headers start with this pre-amble, followed by the fields
937 * specified in the it_present bitmask. If bit 31 of it_present is set, then
938 * another bitmask follows.
939 * @note All of the radiotap data fields are in little-endian byte-order.
940 */
941typedef struct libtrace_radiotap_t {
942    uint8_t     it_version; /**< Radiotap version */
943    uint8_t     it_pad; /**< Padding for natural alignment */
944    uint16_t    it_len; /**< Length in bytes of the entire Radiotap header */
945    uint32_t    it_present; /**< Which Radiotap fields are present */
946} PACKED libtrace_radiotap_t;
947
948/** OSPF header */
949typedef struct libtrace_ospf_v2_t
950{
951        uint8_t ospf_v;         /**< OSPF Version, should be 2 */
952        uint8_t type;           /**< OSPF Packet Type */
953        uint16_t ospf_len;      /**< Packet length, including OSPF header */
954        struct in_addr router;  /**< Router ID of the packet source */
955        struct in_addr area;    /**< Area the packet belongs to */
956        uint16_t sum;           /**< Checksum */
957        uint16_t au_type;       /**< Authentication procedure */
958        uint16_t zero;          /**< Always zero */
959        uint8_t au_key_id;      /**< Authentication Key ID */
960        uint8_t au_data_len;    /**< Authentication Data Length */
961        uint32_t au_seq_num;    /**< Cryptographic Sequence Number */
962} PACKED libtrace_ospf_v2_t;
963
964/** Options Field present in some OSPFv2 packets */
965typedef struct libtrace_ospf_options_t {
966#if __BYTE_ORDER == __LITTLE_ENDIAN
967        LT_BITFIELD8 unused1:1;
968        LT_BITFIELD8 e_bit:1;
969        LT_BITFIELD8 mc_bit:1;
970        LT_BITFIELD8 np_bit:1;
971        LT_BITFIELD8 ea_bit:1;
972        LT_BITFIELD8 dc_bit:1;
973        LT_BITFIELD8 unused2:2;
974#elif __BYTE_ORDER == __BIG_ENDIAN
975        LT_BITFIELD8 unused2:2;
976        LT_BITFIELD8 dc_bit:1;
977        LT_BITFIELD8 ea_bit:1;
978        LT_BITFIELD8 np_bit:1;
979        LT_BITFIELD8 mc_bit:1;
980        LT_BITFIELD8 e_bit:1;
981        LT_BITFIELD8 unused1:1;
982#endif
983} PACKED libtrace_ospf_options_t;
984
985/** LSA Header for OSPFv2 */
986typedef struct libtrace_ospf_lsa_v2_t
987{
988        uint16_t age;           /**< Time in seconds since LSA originated */
989        libtrace_ospf_options_t lsa_options;    /**< Options */
990        uint8_t lsa_type;       /**< LSA type */
991        struct in_addr ls_id;   /**< Link State ID */
992        struct in_addr adv_router; /**< Router that originated this LSA */
993        uint32_t seq;           /**< LS sequence number */
994        uint16_t checksum;      /**< Checksum */
995        uint16_t length;        /**< Length of the LSA including LSA header */
996} PACKED libtrace_ospf_lsa_v2_t;
997
998/** OSPFv2 Hello Packet */
999typedef struct libtrace_ospf_hello_v2_t
1000{
1001        struct in_addr mask;    /**< Network mask for this interface */
1002        uint16_t interval;      /**< Interval between Hello packets (secs) */
1003        libtrace_ospf_options_t hello_options;  /**< Options */
1004        uint8_t priority;       /**< Router Priority */
1005        uint32_t deadint;       /**< Interval before declaring a router down */
1006        struct in_addr designated;      /**< Designated router for the network */
1007        struct in_addr backup;  /**< Backup designated router */
1008
1009        /** Neighbors follow from here, but there can be anywhere from 1 to N
1010         * neighbors so I can't include that here */
1011} PACKED libtrace_ospf_hello_v2_t;
1012
1013/** OSPFv2 Database Description packet */
1014typedef struct libtrace_ospf_db_desc_v2_t
1015{
1016        uint16_t mtu;           /**< Interface MTU */
1017        libtrace_ospf_options_t db_desc_options;        /**< Options */
1018#if __BYTE_ORDER == __LITTLE_ENDIAN
1019        LT_BITFIELD8 db_desc_ms:1;      /**< If set, this router is the master */
1020        LT_BITFIELD8 db_desc_m:1;       /**< If set, more packets to follow */
1021        LT_BITFIELD8 db_desc_i:1;       /**< If set, this is the first packet in sequence */
1022        LT_BITFIELD8 zero:5;
1023#elif __BYTE_ORDER == __BIG_ENDIAN
1024        LT_BITFIELD8 zero:5;
1025        LT_BITFIELD8 db_desc_i:1;       /**< If set, this is the first packet in sequence */
1026        LT_BITFIELD8 db_desc_m:1;       /**< If set, more packets to follow */
1027        LT_BITFIELD8 db_desc_ms:1;      /**< If set, this router is the master */
1028#endif
1029        uint32_t seq;           /**< Sequence number for DD packets */
1030} PACKED libtrace_ospf_db_desc_v2_t;
1031
1032/** OSPF Link State Request Packet */
1033typedef struct libtrace_ospf_ls_req_t
1034{
1035        uint32_t ls_type;       /**< Link State Type */
1036        uint32_t ls_id;         /**< Link State Id */
1037        uint32_t advertising_router;    /**< Advertising Router */
1038} PACKED libtrace_ospf_ls_req_t;
1039
1040/** OSPF Link State Update Packet */
1041typedef struct libtrace_ospf_ls_update_t
1042{
1043        uint32_t ls_num_adv;    /**< Number of LSAs in this packet */
1044
1045        /* Followed by LSAs, use API functions to access these */
1046} PACKED libtrace_ospf_ls_update_t;
1047
1048/** OSPFv2 AS External LSA Body */
1049typedef struct libtrace_ospf_as_external_lsa_t
1050{
1051        struct in_addr netmask; /**< Netmask for the destination */
1052#if __BYTE_ORDER == __LITTLE_ENDIAN
1053        LT_BITFIELD8 tos:7;
1054        LT_BITFIELD8 e:1;       /**< If set, metric is Type 2. Else, Type 1 */
1055#elif __BYTE_ORDER == __BIG_ENDIAN
1056        LT_BITFIELD8 e:1;       /**< If set, metric is Type 2. Else, Type 1 */
1057        LT_BITFIELD8 tos:7;
1058#endif
1059        uint8_t metric_a;       /**< Byte 1 of the Metric field */
1060        uint8_t metric_b;       /**< Byte 2 of the Metric field */
1061        uint8_t metric_c;       /**< Byte 3 of the Metric field */
1062        struct in_addr forwarding;      /**< Forwarding address */
1063        uint32_t external_tag;          /**< External Route Tag */
1064} PACKED libtrace_ospf_as_external_lsa_v2_t;
1065
1066/** OSPFv2 Summary LSA Body */
1067typedef struct libtrace_ospf_summary_lsa
1068{
1069        struct in_addr netmask; /**< Netmask for the destination */
1070        uint8_t zero;           /**< Always zero */
1071        uint8_t metric_a;       /**< Byte 1 of the Metric field */
1072        uint8_t metric_b;       /**< Byte 2 of the Metric field */
1073        uint8_t metric_c;       /**< Byte 3 of the Metric field */
1074       
1075} PACKED libtrace_ospf_summary_lsa_v2_t;
1076
1077/** OSPFv2 Network LSA Body */
1078typedef struct libtrace_ospf_network_lsa_t
1079{
1080        struct in_addr netmask; /**< Netmask for the network */
1081        /* Followed by IDs of attached routers */
1082} PACKED libtrace_ospf_network_lsa_v2_t;
1083
1084/** OSPFv2 Router Link structure */
1085typedef struct libtrace_ospf_link_t
1086{
1087        struct in_addr link_id;         /**< Object that link connects to */
1088        struct in_addr link_data;       /**< Link Data field */
1089        uint8_t type;                   /**< Link Type */
1090        uint8_t num_tos;                /**< Number of TOS metrics */
1091        uint16_t tos_metric;            /**< Cost of router link */
1092} PACKED libtrace_ospf_link_v2_t;
1093
1094/** OSPFv2 Router LSA */
1095typedef struct libtrace_ospf_router_lsa_t
1096{
1097#if __BYTE_ORDER == __LITTLE_ENDIAN
1098        LT_BITFIELD8 b:1;       /**< Area Border Router Flag */
1099        LT_BITFIELD8 e:1;       /**< External Router Flag */
1100        LT_BITFIELD8 v:1;       /**< Virtual Endpoint Flag */
1101        LT_BITFIELD8 zero:5;
1102#elif __BYTE_ORDER == __BIG_ENDIAN
1103        LT_BITFIELD8 zero:5;
1104        LT_BITFIELD8 v:1;       /**< Virtual Endpoint Flag */
1105        LT_BITFIELD8 e:1;       /**< External Router Flag */
1106        LT_BITFIELD8 b:1;       /**< Area Border Router Flag */
1107#endif
1108        uint8_t zero2;          /**< Always zero */
1109        uint16_t num_links;     /**< Number of links in LSA */
1110} PACKED libtrace_ospf_router_lsa_v2_t;
1111
1112/** OSPF message types */
1113typedef enum {
1114        TRACE_OSPF_HELLO = 1,           /**< OSPF Hello */
1115        TRACE_OSPF_DATADESC = 2,        /**< OSPF Database Description */
1116        TRACE_OSPF_LSREQ = 3,           /**< OSPF Link State Request */
1117        TRACE_OSPF_LSUPDATE = 4,        /**< OSPF Link State Update */
1118        TRACE_OSPF_LSACK = 5            /**< OSPF Link State Acknowledgement */
1119} libtrace_ospf_types_t;
1120
1121/** OSPF link state acknowledgement types */
1122typedef enum {
1123        TRACE_OSPF_LS_ROUTER = 1,       /**< OSPF Router LSA */
1124        TRACE_OSPF_LS_NETWORK = 2,      /**< OSPF Network LSA */
1125        TRACE_OSPF_LS_SUMMARY = 3,      /**< OSPF Summary LSA */
1126        TRACE_OSPF_LS_ASBR_SUMMARY = 4, /**< OSPF Summary LSA (ASBR) */
1127        TRACE_OSPF_LS_EXTERNAL = 5      /**< OSPF AS External LSA */
1128} libtrace_ospf_ls_types_t;
1129
1130/** A local definition of an SLL header */
1131typedef struct libtrace_sll_header_t {
1132        uint16_t pkttype;               /**< Packet type */
1133        uint16_t hatype;                /**< Link-layer address type */
1134        uint16_t halen;                 /**< Link-layer address length */
1135        unsigned char addr[8];          /**< Link-layer address */
1136        uint16_t protocol;              /**< Protocol */
1137} libtrace_sll_header_t;
1138
1139
1140/* SLL packet types */
1141
1142/** Packet was addressed for the local host */
1143#define TRACE_SLL_HOST          0
1144/** Packet was addressed for a broadcast address */
1145#define TRACE_SLL_BROADCAST     1
1146/** Packet was addressed for a multicast address */
1147#define TRACE_SLL_MULTICAST     2
1148/** Packet was addressed for another host but was captured by a promiscuous
1149 * device */
1150#define TRACE_SLL_OTHERHOST     3
1151/** Packet originated from the local host */
1152#define TRACE_SLL_OUTGOING      4
1153
1154
1155#ifdef WIN32
1156#pragma pack(pop)
1157#endif
1158
1159
1160/*@}*/
1161
1162/** Prints help information for libtrace
1163 *
1164 * Function prints out some basic help information regarding libtrace,
1165 * and then prints out the help() function registered with each input module
1166 */
1167DLLEXPORT void trace_help(void);
1168
1169/** Causes a libtrace reader to stop blocking whilst waiting on new packets
1170 * and immediately return EOF.
1171 *
1172 * This function is useful if you are handling signals within your libtrace
1173 * program. If a live source is not receiving any packets (or they are being
1174 * filtered), a call to trace_read_packet will result in an infinite loop as
1175 * it will block until a packet is received. Normally, a SIGINT would cause the
1176 * program to end and thus break the loop, but if you are handling the signal
1177 * yourself then that signal will never reach libtrace.
1178 *
1179 * Instead this function sets a global variable within libtrace that will
1180 * cause a blocking live capture to break on the next internal timeout,
1181 * allowing control to be returned to the user and their own signal handling
1182 * to kick in.
1183 */
1184DLLEXPORT void trace_interrupt(void);
1185
1186/** @name Trace management
1187 * These members deal with creating, configuring, starting, pausing and
1188 * cleaning up a trace object
1189 *@{
1190 */
1191
1192/** Takes a uri and splits it into a format and uridata component.
1193 * @param uri           The uri to be parsed
1194 * @param [out] format  A pointer that will be updated to point to an allocated
1195 *                      string holding the format component of the URI
1196 * @return NULL if an error occurred, otherwise return a pointer to the uridata
1197 * component
1198 *
1199 * @note The format component is strdup'd by this function, so be sure to free
1200 * it when you are done with the split URI. Similarly, do not pass a pointer
1201 * to an allocated string into this function as the 'format' parameter, as
1202 * that memory will be leaked and replaced with the strdup'd format.
1203 */
1204DLLEXPORT const char *trace_parse_uri(const char *uri, char **format);
1205
1206/** Create an input trace from a URI
1207 *
1208 * @param uri A valid libtrace URI to be opened
1209 * @return An opaque pointer to a libtrace_t
1210 *
1211 * Some valid URI's are:
1212 *  - erf:/path/to/erf/file
1213 *  - erf:-  (stdin)
1214 *  - dag:/dev/dagcard
1215 *  - pcapint:pcapinterface                (eg: pcap:eth0)
1216 *  - pcap:/path/to/pcap/file
1217 *  - pcap:-
1218 *  - rt:hostname
1219 *  - rt:hostname:port
1220 *
1221 *  If an error occurred when attempting to open the trace file, a
1222 *  trace is still returned so trace_is_err() should be called to find out
1223 *  if an error occurred. The trace is created in the configuration state, you
1224 *  must call trace_start before attempting to read packets from the trace.
1225 */
1226DLLEXPORT libtrace_t *trace_create(const char *uri);
1227
1228/** Creates a "dummy" trace file that has only the format type set.
1229 *
1230 * @param uri A valid (but fake) URI indicating the format of the dummy trace that is to be created.
1231 * @return An opaque pointer to a (sparsely initialised) libtrace_t
1232 *
1233 * Only the format portion of the uri parameter matters - the 'file' being
1234 * opened does not have to exist.
1235 *
1236 * @note IMPORTANT: Do not attempt to call trace_read_packet or other such
1237 * functions with the dummy trace. Its intended purpose is to provide access
1238 * to the format functions where the original trace may no longer exist or is
1239 * not the correct format, e.g. reading ERF packets from an RT input.
1240 */
1241DLLEXPORT libtrace_t *trace_create_dead(const char *uri);
1242
1243/** Creates a trace output file from a URI.
1244 *
1245 * @param uri The uri string describing the output format and destination
1246 * @return An opaque pointer to a libtrace_output_t
1247 *
1248 * Valid URIs include:
1249 *  - erf:/path/to/erf/file
1250 *  - pcap:/path/to/pcap/file
1251 *
1252 *  If an error occurred when attempting to open the output trace, a trace is
1253 *  still returned but trace_errno will be set. Use trace_is_err_out() and
1254 *  trace_perror_output() to get more information.
1255 */
1256DLLEXPORT libtrace_out_t *trace_create_output(const char *uri);
1257
1258/** Start an input trace
1259 * @param libtrace      The trace to start
1260 * @return 0 on success, -1 on failure
1261 *
1262 * This does the actual work of starting the input trace and applying
1263 * all the config options.  This may fail, returning -1. The libtrace error
1264 * handling functions can be used to get more information about what
1265 * specifically went wrong.
1266 */
1267DLLEXPORT int trace_start(libtrace_t *libtrace);
1268
1269/** Pauses an input trace
1270 * @param libtrace      The trace to pause
1271 * @return 0 on success, -1 on failure
1272 *
1273 * This stops an input trace that is in progress and returns you to the
1274 * configuration state.  Any packets that arrive on a live capture after
1275 * trace_pause() has been called will be discarded.  To resume the trace, call
1276 * trace_start().
1277 */
1278DLLEXPORT int trace_pause(libtrace_t *libtrace);
1279
1280/** Start an output trace
1281 * @param libtrace      The trace to start
1282 * @return 0 on success, -1 on failure
1283 *
1284 * This does the actual work with starting a trace capable of writing packets. 
1285 * This generally creates the output file.
1286 */
1287DLLEXPORT int trace_start_output(libtrace_out_t *libtrace);
1288
1289/** Valid configuration options for input traces */
1290typedef enum {
1291        /** Maximum number of bytes to be captured for any given packet */
1292        TRACE_OPTION_SNAPLEN,   
1293
1294        /** If enabled, places a live capture interface into promiscuous mode */
1295        TRACE_OPTION_PROMISC,   
1296
1297        /** Apply this filter to all packets read from this trace */
1298        TRACE_OPTION_FILTER,   
1299
1300        /** Defines the frequency of meta-data reporting, e.g. DUCK packets */
1301        TRACE_OPTION_META_FREQ,
1302
1303        /** If enabled, the libtrace event API will ignore time gaps between
1304         * packets when reading from a trace file */
1305        TRACE_OPTION_EVENT_REALTIME,
1306
1307        /** The hasher function for a parallel libtrace. It is recommended to
1308         * access this option via trace_set_hasher(). */
1309        TRACE_OPTION_HASHER
1310} trace_option_t;
1311
1312/** Sets an input config option
1313 * @param libtrace      The trace object to apply the option to
1314 * @param option        The option to set
1315 * @param value         The value to set the option to
1316 * @return -1 if option configuration failed, 0 otherwise
1317 *
1318 * This should be called after trace_create(), and before trace_start()
1319 *
1320 * @note Please consider using the newer trace_set_X() functions to access
1321 * this function.
1322 */
1323DLLEXPORT int trace_config(libtrace_t *libtrace,
1324                trace_option_t option,
1325                void *value);
1326
1327/** Maximum number of bytes to be captured for any given packet
1328 *
1329 * @param libtrace The trace object to apply the option to
1330 * @param snaplen The snap length to set
1331 * @return -1 if option configuration failed, 0 otherwise
1332 */
1333DLLEXPORT int trace_set_snaplen(libtrace_t *trace, int snaplen);
1334
1335/** If enabled, places a live capture interface into promiscuous mode
1336 *
1337 * @param libtrace The trace object to apply the option to
1338 * @param promisc
1339 * @return -1 if option configuration failed, 0 otherwise
1340 */
1341DLLEXPORT int trace_set_promisc(libtrace_t *trace, bool promisc);
1342
1343/** Apply this filter to all packets read from this trace
1344 *
1345 * @param libtrace The trace object to apply the option to
1346 * @param filter The filter to apply
1347 * @return -1 if option configuration failed, 0 otherwise
1348 */
1349DLLEXPORT int trace_set_filter(libtrace_t *trace, libtrace_filter_t *filter);
1350
1351/** Defines the frequency of meta-data reporting, e.g. DUCK packets
1352 *
1353 * @param libtrace The trace object to apply the option to
1354 * @param freq The meta data frequency
1355 * @return -1 if option configuration failed, 0 otherwise
1356 */
1357DLLEXPORT int trace_set_meta_freq(libtrace_t *trace, int freq);
1358
1359/** If enabled, the libtrace event API will ignore time gaps between
1360 * packets when reading from a trace file.
1361 *
1362 * @param libtrace The trace object to apply the option to
1363 * @param realtime True ignores gaps
1364 * @return -1 if option configuration failed, 0 otherwise
1365 */
1366DLLEXPORT int trace_set_event_realtime(libtrace_t *trace, bool realtime);
1367
1368/** Valid compression types
1369 * Note, this must be kept in sync with WANDIO_COMPRESS_* numbers in wandio.h
1370 */
1371typedef enum {
1372        TRACE_OPTION_COMPRESSTYPE_NONE = 0, /**< No compression */
1373        TRACE_OPTION_COMPRESSTYPE_ZLIB = 1, /**< GZip Compression */
1374        TRACE_OPTION_COMPRESSTYPE_BZ2  = 2, /**< BZip2 Compression */
1375        TRACE_OPTION_COMPRESSTYPE_LZO  = 3,  /**< LZO Compression */
1376        TRACE_OPTION_COMPRESSTYPE_LZMA  = 4,  /**< LZO Compression */
1377        TRACE_OPTION_COMPRESSTYPE_LAST
1378} trace_option_compresstype_t;
1379
1380/** Valid configuration options for output traces */
1381typedef enum {
1382        /** File flags to use when opening an output file, e.g. O_APPEND */
1383        TRACE_OPTION_OUTPUT_FILEFLAGS,
1384        /** Compression level: 0 = no compression, 1 = faster compression,
1385         * 9 = better compression */
1386        TRACE_OPTION_OUTPUT_COMPRESS,
1387        /** Compression type, see trace_option_compresstype_t */
1388        TRACE_OPTION_OUTPUT_COMPRESSTYPE
1389} trace_option_output_t;
1390
1391/* To add a new stat field update this list, and the relevant places in
1392 * libtrace_stat_t structure.
1393 */
1394/** An X Macro set for libtrace stat fields */
1395#define LIBTRACE_STAT_FIELDS \
1396        X(accepted) \
1397        X(filtered) \
1398        X(received) \
1399        X(dropped) \
1400        X(captured) \
1401        X(errors)
1402
1403/**
1404 * Statistic counters are cumulative from the time the trace is started.
1405 * Trace pause will reset the counters, to zero.
1406 * Always check \a{field}_valid is set before attempting to read the stored
1407 * value.
1408 *
1409 * @note Always allocate this structure using trace_create_statistics().
1410 *       This allows us to extend the structure in the future.
1411 */
1412typedef struct libtrace_stat_t {
1413#define X(name) LT_BITFIELD64 name ##_valid : 1;
1414        LIBTRACE_STAT_FIELDS
1415#undef X
1416        /* We use the remaining space as magic to ensure the structure
1417         * was alloc'd by us. We can easily decrease the no. bits without
1418         * problems as long as we update any asserts as needed */
1419        LT_BITFIELD64 reserved1: 26; /**< Bits reserved for future fields */
1420        LT_BITFIELD64 reserved2: 24; /**< Bits reserved for future fields */
1421        LT_BITFIELD64 magic: 8; /**< A number stored against the format to
1422                                  ensure the struct was allocated correctly */
1423
1424        /* These must all be uint64_t's, match this order with the X macro */
1425        /** The number of packets that have been read from the input trace
1426         * using trace_read_packet(). In the parallel framework this may include
1427         * some packets waiting in a batch yet to be seen by the user's
1428         * application.
1429         *
1430         * This does not include filtered packets because these do not make it
1431         * to trace_read_packet().
1432         *
1433         * @note This field replaces trace_get_accepted_packets()
1434         */
1435        uint64_t accepted;
1436
1437        /** The number of packets that were captured, but discarded for not
1438         * matching a provided filter.
1439         *
1440         * @note This field replaces trace_get_filtered_packets()
1441         */
1442        uint64_t filtered;
1443
1444        /** The total number of good packets which have been received. Including
1445         * those which are dropped and filtered. This does not include errors.
1446         *
1447         * @note This may include a small number of buffered packets
1448         *       not yet included in accepted.
1449         *
1450         * @note This field replaces trace_get_received_packets()
1451         */
1452        uint64_t received;
1453
1454        /** The number of packets that have been dropped on an input trace
1455         * due to lack of buffer space on the capturing device. This does not
1456         * included errored packets which are dropped directly by the card.
1457         *
1458         * @note This field replaces trace_get_dropped_packets()
1459         */
1460        uint64_t dropped;
1461
1462        /** The number of received packets that have not been dropped. This
1463         * includes filtered packets.
1464         *
1465         * This is equivalent to received-dropped.
1466         *
1467         * @note This may include a small number of buffered packets
1468         *       not yet included in accepted.
1469         */
1470        uint64_t captured;
1471
1472        /** The number of packets that have been discarded by the network card
1473         * because they are invalid. That includes FCS mismatches, incorrect
1474         * packet lengths etc.
1475         */
1476        uint64_t errors;
1477} libtrace_stat_t;
1478
1479ct_assert(offsetof(libtrace_stat_t, accepted) == 8);
1480
1481/** Sets an output config option
1482 *
1483 * @param libtrace      The output trace object to apply the option to
1484 * @param option        The option to set
1485 * @param value         The value to set the option to
1486 * @return -1 if option configuration failed, 0 otherwise
1487 * This should be called after trace_create_output, and before
1488 * trace_start_output
1489 */
1490DLLEXPORT int trace_config_output(libtrace_out_t *libtrace,
1491                trace_option_output_t option,
1492                void *value
1493                );
1494
1495/** Close an input trace, freeing up any resources it may have been using
1496 *
1497 * @param trace         The input trace to be destroyed
1498 *
1499 */
1500DLLEXPORT void trace_destroy(libtrace_t *trace);
1501
1502/** Close a dummy trace file, freeing up any resources it may have been using
1503 * @param trace         The dummy trace to be destroyed
1504 */
1505DLLEXPORT void trace_destroy_dead(libtrace_t *trace);
1506
1507/** Close an output trace, freeing up any resources it may have been using
1508 * @param trace         The output trace to be destroyed
1509 */
1510DLLEXPORT void trace_destroy_output(libtrace_out_t *trace);
1511
1512/** Check (and clear) the current error state of an input trace
1513 * @param trace         The input trace to check the error state on
1514 * @return The current error status and message
1515 *
1516 * This reads and returns the current error state and sets the current error
1517 * to "no error".
1518 */
1519DLLEXPORT libtrace_err_t trace_get_err(libtrace_t *trace);
1520
1521/** Indicate if there has been an error on an input trace
1522 * @param trace         The input trace to check the error state on
1523 * @return true if an error has occurred, false otherwise
1524 *
1525 * @note This does not clear the error status, and only returns true or false.
1526 */
1527DLLEXPORT bool trace_is_err(libtrace_t *trace);
1528
1529/** Outputs the error message for an input trace to stderr and clear the error
1530 * status.
1531 * @param trace         The input trace with the error to output
1532 * @param msg           The message to prepend to the error
1533 *
1534 * This function does clear the error status.
1535 */
1536DLLEXPORT void trace_perror(libtrace_t *trace, const char *msg,...) PRINTF(2,3);
1537
1538/** Checks (and clears) the current error state for an output trace
1539 * @param trace         The output trace to check the error state on
1540 * @return The current error status and message
1541 *
1542 * This reads and returns the current error state and sets the current error
1543 * to "no error".
1544 */
1545DLLEXPORT libtrace_err_t trace_get_err_output(libtrace_out_t *trace);
1546
1547/** Indicates if there is an error on an output trace
1548 * @param trace         The output trace to check the error state on
1549 * @return true if an error has occurred, false otherwise.
1550 *
1551 * This does not clear the error status, and only returns true or false.
1552 */
1553DLLEXPORT bool trace_is_err_output(libtrace_out_t *trace);
1554
1555/** Outputs the error message for an output trace to stderr and clear the error
1556 * status.
1557 * @param trace         The output trace with the error to output
1558 * @param msg           The message to prepend to the error
1559 * This function does clear the error status.
1560 */
1561DLLEXPORT void trace_perror_output(libtrace_out_t *trace, const char *msg,...)
1562        PRINTF(2,3);
1563
1564/** Returns the number of packets observed on an input trace.
1565 * Includes the number of packets counted as early as possible, before
1566 * filtering, and includes dropped packets.
1567 *
1568 * @param trace         The input trace to examine
1569 * @returns The number of packets seen at the capture point before filtering.
1570 *
1571 * If the number is not known, this function will return UINT64_MAX
1572 *
1573 * @deprecated This function is deprecated: Use trace_get_statistics(), this
1574 *             allows all statistic counters to be read in an atomic manner.
1575 */
1576DLLEXPORT DEPRECATED
1577uint64_t trace_get_received_packets(libtrace_t *trace);
1578
1579/** Returns the number of packets that were captured, but discarded for not
1580 * matching a provided filter.
1581 *
1582 * @param trace         The input trace to examine
1583 * @returns The number of packets that were successfully captured, but filtered
1584 *
1585 * If the number is not known, this function will return UINT64_MAX
1586 *
1587 * @deprecated This function is deprecated: Use trace_get_statistics(), this
1588 *             allows all statistic counters to be read in an atomic manner.
1589 */
1590DLLEXPORT DEPRECATED
1591uint64_t trace_get_filtered_packets(libtrace_t *trace);
1592
1593/** Returns the number of packets that have been dropped on an input trace due
1594 * to lack of buffer space on the capturing device.
1595 *
1596 * @param trace         The input trace to examine
1597 * @returns The number of packets captured, but dropped due to buffer overruns
1598 *
1599 * If the number is not known, this function will return UINT64_MAX
1600 *
1601 * @deprecated This function is deprecated: Use trace_get_statistics(), this
1602 *             allows all statistic counters to be read in an atomic manner.
1603 */
1604DLLEXPORT DEPRECATED
1605uint64_t trace_get_dropped_packets(libtrace_t *trace);
1606
1607/** Returns the number of packets that have been read from the input trace using
1608 * trace_read_packet().
1609 *
1610 * @param trace         The input trace to examine
1611 * @returns The number of packets that have been read by the libtrace user.
1612 *
1613 * If the number is not known, this function will return UINT64_MAX
1614 *
1615 * @deprecated This function is deprecated: Use trace_get_statistics(), this
1616 *             allows all statistic counters to be read in an atomic manner.
1617 */
1618DLLEXPORT DEPRECATED
1619uint64_t trace_get_accepted_packets(libtrace_t *trace);
1620
1621/**
1622 * Returns statistic counters for a trace, for a parallel trace this is a
1623 * combined total.
1624 * Where possible these are retrieved atomically, however this behaviour depends
1625 * on the underlying trace format.
1626 *
1627 * @param trace The input trace to examine.
1628 * @param stats Optional, Filled upon return with statistics about the trace,
1629 *              check the flags included to see if a given statistic is valid.
1630 *              If NULL a statistic structure owned by libtrace is returned, this
1631 *              should not be free'd and will become invalid if the trace is
1632 *              destroyed.
1633 *
1634 * @return A pointer to the statistics structure.
1635 * @note Use trace_create_stat() to create the stats object, this way future
1636 *       versions of libtrace can add to the structure without breaking existing
1637 *       code.
1638 */
1639DLLEXPORT
1640libtrace_stat_t *trace_get_statistics(libtrace_t *trace, libtrace_stat_t *stats);
1641
1642
1643/**
1644 * Returns statistic counters for a single thread of a trace.
1645 * Where possible these are retrieved atomically, however this behaviour depends
1646 * on the underlying trace format.
1647 *
1648 * @param trace The input trace to examine.
1649 * @param t An optional thread to received stats for or NULL to retrieve stats
1650 *          for the current thread
1651 * @param stats Filled upon return with statistics about the trace, check the
1652 *              flags included to see if a given statistic is valid.
1653 *
1654 * @note Use trace_create_stat() to create the stats object, this way future
1655 *       versions of libtrace can add to the structure without breaking existing
1656 *       code.
1657 */
1658DLLEXPORT
1659void trace_get_thread_statistics(libtrace_t *trace, libtrace_thread_t *t,
1660                                 libtrace_stat_t *stats);
1661
1662/**
1663 * Creates and returns a zeroed libtrace_stat_t structure.
1664 *
1665 * This allows us to add extra fields increasing the size of the structure
1666 * without breaking existing libtrace applications.
1667 *
1668 * This structure should be free'd using free().
1669 *
1670 * @return A valid pointer to a libtrace_stat_t struct otherwise NULL if
1671 *         memory was not available.
1672 */
1673DLLEXPORT libtrace_stat_t* trace_create_statistics(void);
1674
1675/**
1676 * Clear all fields of given statistic.
1677 * This api doesn't verify the magic field unlike other stat apis.
1678 *
1679 * @param s The statistic structure to clear
1680 */
1681DLLEXPORT
1682void trace_clear_statistics(libtrace_stat_t *s);
1683
1684/**
1685 * Performs the operation c=a-b accounting for valid fields.
1686 * c is allowed to be a or b.
1687 *
1688 * @param a The minuend
1689 * @param b The subtrahend
1690 * @param c The resulting difference
1691 */
1692DLLEXPORT
1693void trace_subtract_statistics(const libtrace_stat_t *a,
1694                               const libtrace_stat_t *b, libtrace_stat_t *c);
1695
1696/**
1697 * Performs operation c=a+b accounting for valid fields.
1698 * c is allowed to be a or b.
1699 *
1700 * @param a The first operand
1701 * @param b The second operand
1702 * @param c The result
1703 */
1704DLLEXPORT
1705void trace_add_statistics(const libtrace_stat_t *a,
1706                          const libtrace_stat_t *b, libtrace_stat_t *c);
1707
1708/**
1709 * Prints all valid stats to a file stream, (which could be stdout/err).
1710 * By default the format "name: value" is used.
1711 *
1712 * @param s The statistic structure to print
1713 * @param f The output file stream
1714 * @param format An optional format string such as the default ("%s: %"PRIu64"\n")
1715 *               This is passed to fprintf and called with two arguments
1716 *               first a char* (%s) and second a uint64_t (%PRIu64).
1717 *
1718 * @return -1 if an error occurs when writing to the file stream, check errno.
1719 *         Otherwise 0.
1720 */
1721DLLEXPORT
1722int trace_print_statistics(const libtrace_stat_t *s, FILE *f,
1723                           const char *format);
1724
1725
1726/*@}*/
1727
1728/** @name Reading / Writing packets
1729 * These members deal with creating, reading and writing packets
1730 *
1731 * @{
1732 */
1733
1734/** Create a new packet object
1735 *
1736 * @return A pointer to an initialised libtrace_packet_t object, or NULL if
1737 * libtrace is unable to allocate space for a new packet.
1738 */
1739DLLEXPORT libtrace_packet_t *trace_create_packet(void);
1740
1741/** Copy a packet object
1742 * @param packet        The source packet to copy
1743 * @return A new packet which has the same content as the source packet
1744 *
1745 * @note This always involves a copy, which can be slow.  Use of this
1746 * function should be avoided where possible.
1747 *
1748 * @par The reason you would want to use this function is that a zero-copied
1749 * packet from a device will be stored using memory owned by the device which
1750 * may be a limited resource. Copying the packet will ensure that the packet
1751 * is now stored in memory owned and managed by libtrace.
1752 */
1753DLLEXPORT libtrace_packet_t *trace_copy_packet(const libtrace_packet_t *packet);
1754
1755/** Destroy a packet object
1756 * @param packet        The packet to be destroyed
1757 *
1758 */
1759DLLEXPORT void trace_destroy_packet(libtrace_packet_t *packet);
1760
1761
1762/** Read the next packet from an input trace
1763 *
1764 * @param trace         The libtrace opaque pointer for the input trace
1765 * @param packet        The packet opaque pointer
1766 * @return 0 on EOF, negative value on error, number of bytes read when successful.
1767 *
1768 * @note The number of bytes read is usually (but not always) the same as
1769 * trace_get_framing_length()+trace_get_capture_length() depending on the
1770 * trace format.
1771 *
1772 * @note The trace must have been started with trace_start before calling
1773 * this function
1774 *
1775 * @note When reading from a live capture, this function will block until a
1776 * packet is observed on the capture interface. The libtrace event API
1777 * (e.g. trace_event()) should be used if non-blocking operation is required.
1778 */
1779DLLEXPORT int trace_read_packet(libtrace_t *trace, libtrace_packet_t *packet);
1780
1781/** Event types
1782 * see \ref libtrace_eventobj_t and \ref trace_event
1783 */
1784typedef enum {
1785        TRACE_EVENT_IOWAIT,     /**< Wait on the given file descriptor */
1786        TRACE_EVENT_SLEEP,      /**< Sleep for the given amount of time */
1787        TRACE_EVENT_PACKET,     /**< Packet has been read from input trace */
1788        TRACE_EVENT_TERMINATE   /**< End of input trace */
1789} libtrace_event_t;
1790
1791/** Structure returned by libtrace_event explaining what the current event is */
1792typedef struct libtrace_eventobj_t {
1793        libtrace_event_t type; /**< Event type (iowait,sleep,packet) */
1794       
1795        /** If the event is IOWAIT, the file descriptor to wait on */
1796        int fd;               
1797        /** If the event is SLEEP, the amount of time to sleep for in seconds */
1798        double seconds;       
1799        /** If the event is PACKET, the value returned by trace_read_packet() */
1800        int size;
1801} libtrace_eventobj_t;
1802
1803/** Processes the next libtrace event from an input trace.
1804 * @param trace The libtrace opaque pointer for the input trace
1805 * @param packet The libtrace_packet opaque pointer to use for reading packets
1806 * @return A libtrace_event struct containing the event type and details of the event.
1807 *
1808 * Type can be:
1809 *  TRACE_EVENT_IOWAIT  Waiting on I/O on a file descriptor
1810 *  TRACE_EVENT_SLEEP   Wait a specified amount of time for the next event
1811 *  TRACE_EVENT_PACKET  Packet was read from the trace
1812 *  TRACE_EVENT_TERMINATE Trace terminated (perhaps with an error condition)
1813 */
1814DLLEXPORT libtrace_eventobj_t trace_event(libtrace_t *trace,
1815                libtrace_packet_t *packet);
1816
1817
1818/** Write one packet out to the output trace
1819 *
1820 * @param trace         The libtrace_out opaque pointer for the output trace
1821 * @param packet        The packet opaque pointer of the packet to be written
1822 * @return The number of bytes written out, if zero or negative then an error has occured.
1823 */
1824DLLEXPORT int trace_write_packet(libtrace_out_t *trace, libtrace_packet_t *packet);
1825
1826/** Gets the capture format for a given packet.
1827 * @param packet        The packet to get the capture format for.
1828 * @return The capture format of the packet
1829 *
1830 * @note Due to ability to convert packets between formats relatively easily
1831 * in Libtrace, the format of the packet right now may not be the format that
1832 * the packet was originally captured with.
1833 */
1834DLLEXPORT
1835enum base_format_t trace_get_format(struct libtrace_packet_t *packet);
1836
1837/** Construct a libtrace packet from a buffer containing the packet payload.
1838 * @param[in,out] packet        Libtrace Packet object to update with the new
1839 *                              data.
1840 * @param linktype              The linktype of the packet data.
1841 * @param[in] data              The packet data (including linklayer).
1842 * @param len                   Length of packet data provided in the buffer.
1843 *
1844 * @note The constructed packet will be in the PCAP format.
1845 *
1846 * @note To be useful, the provided buffer must start with the layer 2 header
1847 * (or a metadata header, if desired).
1848 */
1849DLLEXPORT
1850void trace_construct_packet(libtrace_packet_t *packet,
1851                libtrace_linktype_t linktype, const void *data, uint16_t len);
1852
1853/*@}*/
1854
1855/** @name Protocol decodes
1856 * These functions locate and return a pointer to various headers inside a
1857 * packet
1858 *
1859 * A packet is divided up into several "layers.":
1860 *
1861 * @li Framing header -- This is the header provided by the capture format
1862 * itself rather than anything that was sent over the network. This provides
1863 * basic details about the packet record including capture lengths, wire
1864 * lengths, timestamps, direction information and any other metadata that is
1865 * part of the capture format. 
1866 *
1867 * @li Metadata header (optional) -- A header containing metadata about a
1868 * packet that was captured, but the metadata was not transmitted over the
1869 * wire.  Some examples include RadioTap and Linux_sll headers.  This can be
1870 * retrieved by trace_get_packet_meta(), or skipped using
1871 * trace_get_payload_from_meta(). There may be multiple "metadata" headers on
1872 * a packet.
1873 *
1874 * @li Layer 2/Link layer/Datalink header -- This can be retrieved by
1875 * trace_get_layer2(), or skipped using trace_get_payload_from_layer2().
1876 *
1877 * @li Layer 3/IP/IPv6 -- This can be retrieved by trace_get_layer3().  As a
1878 * convenience trace_get_ip()/trace_get_ip6() can be used to find an IPv4/IPv6
1879 * header.
1880 *
1881 * @li Layer 5/transport -- These are protocols carried in IPv4/IPv6 frames.
1882 * These can be retrieved using trace_get_transport().
1883 *
1884 * @{
1885 */
1886
1887
1888/** Gets a pointer to the first byte of the packet as it was captured and
1889 * returns its corresponding linktype and capture length.
1890 *
1891 * Use this function instead of the deprecated trace_get_link().
1892 *
1893 * @param packet The packet to get the buffer from
1894 * @param[out] linktype The linktype of the returned pointer
1895 * @param[out] remaining The capture length (the number of captured bytes from
1896 * the returned pointer)
1897 * @return A pointer to the first byte of the packet
1898 */
1899DLLEXPORT void *trace_get_packet_buffer(const libtrace_packet_t *packet,
1900                libtrace_linktype_t *linktype, uint32_t *remaining);
1901
1902/** Get a pointer to the link layer for a given packet
1903 * @param packet        The packet to get the link layer for
1904 *
1905 * @return A pointer to the link layer, or NULL if there is no link layer
1906 *
1907 * @deprecated This function is deprecated: Use trace_get_packet_buffer() or
1908 * one of the trace_get_layer*() functions instead.
1909 * @note You should call trace_get_link_type to find out what type of link
1910 * layer has been returned to you.
1911 */
1912DLLEXPORT SIMPLE_FUNCTION DEPRECATED
1913void *trace_get_link(const libtrace_packet_t *packet);
1914
1915/** Strips layer 2.5 headers from a given packet.
1916 * @param packet        The packet to strip headers from.
1917 *
1918 * @return The packet with the requested headers removed (if they were
1919 * present).
1920 *
1921 * This function is intended for removing those pesky layer 2.5 headers
1922 * that are not supported by other packet analysis applications, e.g. VLAN
1923 * and MPLS headers. If successful, the resulting packet will be a simple
1924 * Ethernet-IP-Transport packet that just about anything should be able to
1925 * parse without difficulty.
1926 *
1927 * If this function encounters a layer 2 or 2.5 header that it does not
1928 * support, stripping will cease and the packet returning will be stripped
1929 * up to but not including the unsupported header.
1930 *
1931 * New in libtrace 4.0.0
1932 *
1933 * @note This function only supports stripping headers from Ethernet packets
1934 * for now. Passing in packets of other link types will simply result in
1935 * the original packet being returned unmodified.
1936 *
1937 */
1938DLLEXPORT libtrace_packet_t *trace_strip_packet(libtrace_packet_t *packet);
1939
1940/** Get a pointer to the IPv4 header (if any) for a given packet
1941 * @param packet        The packet to get the IPv4 header for
1942 *
1943 * @return A pointer to the IPv4 header, or NULL if there is no IPv4 header
1944 *
1945 * If a partial IP header is present, i.e. the packet has been truncated before
1946 * the end of the IP header, this function will return NULL.
1947 *
1948 * You should consider using \ref trace_get_layer3 instead of this function.
1949 */
1950DLLEXPORT SIMPLE_FUNCTION
1951libtrace_ip_t *trace_get_ip(libtrace_packet_t *packet);
1952
1953/** get a pointer to the IPv6 header (if any)
1954 * @param packet        The packet to get the IPv6 header for
1955 *
1956 * @return A pointer to the IPv6 header, or NULL if there is no IPv6 header
1957 *
1958 * If a partial IPv6 header is present, i.e. the packet has been truncated
1959 * before the end of the IP header, this function will return NULL.
1960 *
1961 * You should consider using \ref trace_get_layer3 instead of this function.
1962 */
1963DLLEXPORT SIMPLE_FUNCTION
1964libtrace_ip6_t *trace_get_ip6(libtrace_packet_t *packet);
1965
1966/** Return a pointer to the first metadata header in a packet, if present.
1967 *
1968 * This function takes a pointer to a libtrace packet and if any metadata
1969 * headers exist, returns a pointer to the first one, along with its
1970 * corresponding linktype.
1971 *
1972 * If no metadata headers exist in the packet, NULL is returned.
1973 *
1974 * A metadata header is a header that was prepended by the capturing device,
1975 * such as a Linux SLL header, or a Radiotap wireless monitoring header.
1976 * Subsequent metadata headers may be accessed with the
1977 * trace_get_payload_from_meta(...) function.
1978 *
1979 * @param packet The libtrace packet
1980 * @param[out] linktype The linktype of the returned metadata header
1981 * @param[out] remaining The number of bytes captured after the returned
1982 * pointer.
1983 * @return A pointer to the first metadata header, or NULL if there are no
1984 * metadata headers present.
1985 *
1986 * remaining may be NULL, however linktype must be provided.
1987 */
1988DLLEXPORT void *trace_get_packet_meta(const libtrace_packet_t *packet,
1989                libtrace_linktype_t *linktype,
1990                uint32_t *remaining);
1991
1992/** Returns the payload of a metadata header.
1993 *
1994 * This function takes a pointer to the start of a metadata header (either
1995 * obtained via trace_get_packet_meta(...) or by a previous call to
1996 * trace_get_payload_from_meta(...)) along with its corresponding linktype and
1997 * returns the payload, i.e. the next header. It will also update the linktype
1998 * parameter to indicate the type of payload.
1999 * 
2000 * If the linktype indicates that the header passed in is not a metadata
2001 * header, the function returns NULL to indicate this. The linktype remains
2002 * unchanged in this case.
2003 *
2004 * This function allows the user to iterate through metadata headers which are
2005 * sometimes present before the actual packet as it was received on the wire.
2006 * Examples of metadata headers include the Linux SLL header and the Radiotap
2007 * wireless monitoring header.
2008 *
2009 * If the metadata header passed into this function is truncated, this
2010 * function will return NULL, and remaining will be set to 0.
2011 *
2012 * If there are 0 bytes of payload following the provided metadata header, the
2013 * function will return a pointer to where the header would otherwise be and
2014 * remaining will be 0.
2015 *
2016 * Therefore, be sure to check the value of remaining after calling this
2017 * function!
2018 *
2019 * @param[in] meta A pointer to a metadata header
2020 * @param[in,out] linktype The linktype of meta (updated to indicate the
2021 * linktype of the returned header if applicable).
2022 * @param[in,out] remaining The number of bytes after the meta pointer.
2023 * @return A pointer to the payload of the metadata header. If meta is not a
2024 * pointer to a metadata header, NULL is returned and linktype remains
2025 * unchanged.
2026 *
2027 * All parameters are mandatory.
2028 */
2029DLLEXPORT void *trace_get_payload_from_meta(const void *meta,
2030                libtrace_linktype_t *linktype,
2031                uint32_t *remaining);
2032
2033
2034/** Get a pointer to the layer 2 header. Generally this is the first byte of the
2035 * packet as it was seen on the wire.
2036 *
2037 * This function takes a libtrace packet and skips over any metadata headers if
2038 * present (such as Linux SLL or Radiotap) and returns a pointer to the first
2039 * byte of the packet that was actually received by the network interface.
2040 *
2041 * @param packet The libtrace packet to find the layer 2 header for
2042 * @param[out] linktype The linktype of the returned layer 2 header
2043 * @param[out] remaining The number of bytes left in the packet after the
2044 * returned pointer.
2045 * @return A pointer to the first byte of the packet as it was seen on the
2046 * wire. If no layer 2 header is present, this function will return NULL.
2047 *
2048 * remaining may be NULL, otherwise it will be filled in by the function.
2049 */
2050DLLEXPORT void *trace_get_layer2(const libtrace_packet_t *packet,
2051                libtrace_linktype_t *linktype,
2052                uint32_t *remaining);
2053
2054/** Gets a pointer to the next header following a layer 2 header
2055 *
2056 * @param l2                    The pointer to the current layer 2 header
2057 * @param linktype              The type of the layer 2 header
2058 * @param[out] ethertype        An optional output variable of the ethernet type of the new header
2059 * @param[in,out] remaining     Updated with the number of captured bytes
2060                                remaining
2061 *
2062 * @return A pointer to the header following the provided layer 2 header, or
2063 * NULL if no subsequent header is present.
2064 *
2065 * Remaining must point to the number of bytes captured from the layer 2 header
2066 * and beyond.  It will be decremented by the number of bytes skipped to find
2067 * the payload.
2068 *
2069 * If the layer 2 header is complete but there are zero bytes of payload after
2070 * the end of the header, a pointer to where the payload would be is returned
2071 * and remaining will be set to 0.  If the layer 2 header is incomplete
2072 * (truncated), then NULL is returned and remaining will be set to 0.
2073 * Therefore, it is very important to check the value of remaining after
2074 * calling this function.
2075 *
2076 */
2077DLLEXPORT void *trace_get_payload_from_layer2(void *l2,
2078                libtrace_linktype_t linktype,
2079                uint16_t *ethertype,
2080                uint32_t *remaining);
2081
2082
2083/** Get a pointer to the layer 3 (e.g. IP) header.
2084 * @param packet  The libtrace packet to find the layer 3 header for
2085 * @param[out] ethertype The ethertype of the layer 3 header
2086 * @param[out] remaining The amount of captured data remaining in the packet starting from the returned pointer, i.e. including the layer 3 header.
2087 *
2088 * @return A pointer to the layer 3 header. If no layer 3 header is present in
2089 * the packet, NULL is returned. If the layer 3 header is truncated, a valid
2090 * pointer will still be returned so be sure to check the value of remaining
2091 * before attempting to process the returned header.
2092 *
2093 * remaining may be NULL, otherwise it will be set to the number of captured
2094 * bytes after the pointer returned.
2095 */
2096DLLEXPORT
2097void *trace_get_layer3(const libtrace_packet_t *packet,
2098                uint16_t *ethertype, uint32_t *remaining);
2099
2100/** Calculates the expected IP checksum for a packet.
2101 * @param packet        The libtrace packet to calculate the checksum for
2102 * @param[out] csum     The checksum that is calculated by this function. This
2103 *                      may not be NULL.
2104 *
2105 * @return A pointer to the original checksum field within the IP
2106 * header. If the checksum field is not present in the packet, NULL is returned.
2107 *
2108 * @note The return value points to the checksum that exists within the current
2109 * packet. The value in csum is the value that the checksum should be, given
2110 * the current packet contents. 
2111 *
2112 * @note This function involves the use of a memcpy, so be careful about
2113 * calling it excessively if performance is a concern for you.
2114 *
2115 * New in libtrace 3.0.17
2116 */
2117DLLEXPORT uint16_t *trace_checksum_layer3(libtrace_packet_t *packet,
2118                uint16_t *csum);
2119
2120/** Calculates the expected checksum for the transport header in a packet.
2121 * @param packet        The libtrace packet to calculate the checksum for
2122 * @param[out] csum     The checksum that is calculated by this function. This
2123 *                      may not be NULL.
2124 *
2125 * @return A pointer to the original checksum field within the transport
2126 * header. If the checksum field is not present in the packet, NULL is returned.
2127 *
2128 * @note The return value points to the checksum that exists within the current
2129 * packet. The value in csum is the value that the checksum should be, given
2130 * the current packet contents. 
2131 *
2132 * @note This function involves the use of a memcpy, so be careful about
2133 * calling it excessively if performance is a concern for you.
2134 *
2135 * @note Because transport checksums are calculated across the entire payload,
2136 * truncated packets will result in NULL being returned.
2137 *
2138 * This function will determine the appropriate checksum for whatever transport
2139 * layer header is present in the provided packet. At this stage, this only
2140 * currently works for TCP, UDP and ICMP packets.
2141 *
2142 * Be wary of TCP checksum offloading if you are examining the checksum of
2143 * packets captured on the same host that generated them!
2144 *
2145 * New in libtrace 3.0.17
2146 */
2147DLLEXPORT uint16_t *trace_checksum_transport(libtrace_packet_t *packet,
2148                uint16_t *csum);
2149
2150/** Calculates the fragment offset in bytes for an IP packet
2151 * @param packet        The libtrace packet to calculate the offset for
2152 * @param[out] more     A boolean flag to indicate whether there are more
2153 *                      fragments after the current packet.
2154 * @return The fragment offset for the packet in bytes. If the packet is not
2155 * an IP packet or the fragment offset is not present in packet, the return
2156 * value will be 0.
2157 *
2158 * @note The value returned is in bytes, not 8-octet units as it is stored
2159 * in the fragment offset field in the headers. In other words, libtrace
2160 * automatically does the multiplication for you.
2161 *
2162 * The value passed in for 'more' does not matter; it will be overwritten
2163 * with the value of the More Fragments flag from the IP header.
2164 *
2165 * New in libtrace 3.0.20
2166 */
2167DLLEXPORT uint16_t trace_get_fragment_offset(const libtrace_packet_t *packet,
2168                uint8_t *more);
2169
2170/** Gets a pointer to the transport layer header (if any)
2171 * @param packet   The libtrace packet to find the transport header for
2172 * @param[out] proto    The protocol present at the transport layer.
2173 * @param[out] remaining The amount of captured data remaining in the packet
2174 * starting from the returned pointer, i.e. including the transport header.
2175 *
2176 * @return A pointer to the transport layer header. If no transport header is
2177 * present in the packet, NULL is returned. If the transport header is
2178 * truncated, a valid pointer will still be returned so be sure to check the
2179 * value of remaining before attempting to process the returned header.
2180 *
2181 * remaining may be NULL, otherwise it will be set to the number of captured
2182 * bytes after the returned pointer.
2183 *
2184 * @note proto may be NULL if proto is unneeded.
2185 */
2186DLLEXPORT void *trace_get_transport(const libtrace_packet_t *packet,
2187                uint8_t *proto, uint32_t *remaining);
2188
2189/** Gets a pointer to the payload following an IPv4 header
2190 * @param ip            The IPv4 Header
2191 * @param[out] proto    The protocol of the header following the IPv4 header
2192 * @param[in,out] remaining Updated with the number of captured bytes remaining
2193 *
2194 * @return A pointer to the transport layer header, or NULL if no subsequent
2195 * header is present.
2196 *
2197 * When calling this function, remaining must contain the number of captured
2198 * bytes remaining in the packet starting from the IPv4 header (including the
2199 * IPv4 header itself).
2200 *
2201 * remaining will be decremented by the size of the IPv4 header (including any
2202 * options). If the IPv4 header is complete but there are zero bytes of payload
2203 * after the IPv4 header, a pointer to where the payload would be is returned
2204 * and remaining will be set to 0.  If the IPv4 header is incomplete, NULL will
2205 * be returned and remaining will be set to 0. Therefore, it is very important
2206 * to check the value of remaining after calling this function.
2207 *
2208 * proto may be NULL, in which case it won't be updated.
2209 *
2210 * @note This is similar to trace_get_transport_from_ip in libtrace2
2211 */
2212DLLEXPORT void *trace_get_payload_from_ip(libtrace_ip_t *ip, uint8_t *proto,
2213                uint32_t *remaining);
2214
2215/** Gets a pointer to the payload following an IPv6 header
2216 * @param ipptr         The IPv6 Header
2217 * @param[out] proto    The protocol of the header following the IPv6 header
2218 * @param[in,out] remaining Updated with the number of captured bytes remaining
2219 *
2220 * @return A pointer to the transport layer header, or NULL if no subsequent
2221 * header is present.
2222 *
2223 * When calling this function, remaining must contain the number of captured
2224 * bytes remaining in the packet starting from the IPv6 header (including the
2225 * IPv6 header itself).
2226 *
2227 * remaining will be decremented by the size of the IPv6 header (including any
2228 * options). If the IPv6 header is complete but there are zero bytes of payload
2229 * after the IPv6 header, a pointer to where the payload would be is returned
2230 * and remaining will be set to 0.  If the IPv6 header is incomplete, NULL will
2231 * be returned and remaining will be set to 0. Therefore, it is very important
2232 * to check the value of remaining after calling this function.
2233 *
2234 * proto may be NULL, in which case it won't be updated.
2235 *
2236 */
2237DLLEXPORT void *trace_get_payload_from_ip6(libtrace_ip6_t *ipptr,
2238                uint8_t *proto, uint32_t *remaining);
2239
2240/** Gets a pointer to the payload following a link header
2241 * @param linkptr       A pointer to the link layer header
2242 * @param linktype      The linktype of the link header being examined
2243 * @param[out] type     An output variable for the ethernet type
2244 * @param[in,out] remaining Updated with the number of captured bytes remaining
2245 *
2246 * @return A pointer to the header following the link header, or NULL if no
2247 * subsequent header is present.
2248 *
2249 * When calling this function, remaining must contain the number of captured
2250 * bytes remaining in the packet starting from the link header (including the
2251 * link header itself). remaining will be updated to contain the number of
2252 * bytes remaining after the link header has been skipped.
2253 *
2254 * @deprecated This function is deprecated: you should be using
2255 * trace_get_payload_from_layer2() or trace_get_payload_from_meta() instead.
2256 *
2257 */
2258DLLEXPORT void *trace_get_payload_from_link(void *linkptr,
2259                libtrace_linktype_t linktype,
2260                uint16_t *type, uint32_t *remaining);
2261
2262/** Gets a pointer to the payload following an 802.1q (VLAN) header.
2263 * @param vlan      A pointer to the VLAN header
2264 * @param[out] type  The ethernet type, replaced with the VLAN ether type
2265 * @param[in,out] remaining Updated with the number of captured bytes remaining
2266 *
2267 * @return A pointer to the header beyond the VLAN header, if one is present.
2268 * Otherwise, returns NULL. 
2269 *
2270 * When calling this function, remaining must contain the number of captured
2271 * bytes remaining in the packet starting from the VLAN header (including the
2272 * VLAN header itself). remaining will be updated to contain the number of
2273 * bytes remaining after the VLAN header has been skipped.
2274 *
2275 * If the VLAN header is complete but there are zero bytes of payload after
2276 * the VLAN header, a pointer to where the payload would be is returned and
2277 * remaining will be set to 0.  If the VLAN header is incomplete, NULL will be
2278 * returned and remaining will be set to 0. Therefore, it is important to check
2279 * the value of remaining after calling this function.
2280 *
2281 * type will be set to the ethertype of the VLAN payload. This parameter is not
2282 * mandatory, but is highly recommended.
2283 *
2284 */
2285DLLEXPORT void *trace_get_payload_from_vlan(
2286                void *vlan, uint16_t *type, uint32_t *remaining);
2287
2288/** Gets a pointer to the payload following an MPLS header.
2289 * @param mpls      A pointer to the MPLS header
2290 * @param[out] type  The ethernet type, replaced by the ether type of the
2291 * returned header - 0x0000 if an Ethernet header is returned
2292 * @param[in,out] remaining Updated with the number of captured bytes remaining
2293 *
2294 * @return A pointer to the header beyond the MPLS label, if one is present.
2295 * Will return NULL if there is not enough bytes remaining to skip past the
2296 * MPLS label.
2297 *
2298 * When calling this function, remaining must contain the number of captured
2299 * bytes remaining in the packet starting from the MPLS header (including the
2300 * MPLS header itself). remaining will be updated to contain the number of
2301 * bytes remaining after the MPLS header has been skipped.
2302 *
2303 * If the MPLS header is complete but there are zero bytes of payload after
2304 * the MPLS header, a pointer to where the payload would be is returned and
2305 * remaining will be set to 0.  If the MPLS header is incomplete, NULL will be
2306 * returned and remaining will be set to 0. Therefore, it is important to check
2307 * the value of remaining after calling this function.
2308 *
2309 * type will be set to the ethertype of the MPLS payload. This parameter is
2310 * mandatory - it may not be NULL.
2311 *
2312 * @note This function will only remove one MPLS label at a time - the type
2313 * will be set to 0x8847 if there is another MPLS label following the one
2314 * skipped by this function.
2315 *
2316 */
2317DLLEXPORT void *trace_get_payload_from_mpls(
2318                void *mpls, uint16_t *type, uint32_t *remaining);
2319
2320/** Gets a pointer to the payload following a PPPoE header
2321 * @param pppoe      A pointer to the PPPoE header
2322 * @param[out] type  The ethernet type, replaced by the ether type of the
2323 * returned header - 0x0000 if an Ethernet header is returned
2324 * @param[in,out] remaining  Updated with the number of captured bytes remaining
2325 *
2326 * @return A pointer to the header beyond the PPPoE header. NOTE that this
2327 * function will also skip over the PPP header that will immediately follow
2328 * the PPPoE header. This function will return NULL if there are not enough
2329 * bytes remaining to skip past both the PPPoE and PPP headers.
2330 *
2331 * When calling this function, remaining must contain the number of captured
2332 * bytes remaining in the packet starting from the PPPoE header (including the
2333 * PPPoE header itself). remaining will be updated to contain the number of
2334 * bytes remaining after the PPPoE and PPP headers have been removed.
2335 *
2336 * If the PPPoE and PPP headers are complete but there are zero bytes of
2337 * payload after the PPP header, a pointer to where the payload would be is
2338 * returned and remaining will be set to 0.  If the PPPoE or PPP header is
2339 * incomplete, NULL will be returned and remaining will be set to 0. Therefore,
2340 * it is important to check the value of remaining after calling this function.
2341 *
2342 * type will be set to the ether type of the PPP payload. This parameter is
2343 * mandatory - it may not be NULL.
2344 *
2345 */
2346DLLEXPORT void *trace_get_payload_from_pppoe(
2347                void *pppoe, uint16_t *type, uint32_t *remaining);
2348
2349/** Gets a pointer to the payload following a TCP header
2350 * @param tcp           A pointer to the TCP header
2351 * @param[in,out] remaining Updated with the number of captured bytes remaining
2352 *
2353 * @return A pointer to the TCP payload, or NULL if the TCP header is truncated.
2354 *
2355 * When calling this function, remaining must contain the number of captured
2356 * bytes remaining in the packet starting from the TCP header (including the
2357 * TCP header itself). remaining will be updated to contain the number of
2358 * bytes remaining after the TCP header has been skipped.
2359 *
2360 * If the TCP header is complete but there are zero bytes of payload after
2361 * the TCP header, a pointer to where the payload would be is returned and
2362 * remaining will be set to 0.  If the TCP header is incomplete, NULL will be
2363 * returned and remaining will be set to 0. Therefore, it is important to check
2364 * the value of remaining after calling this function.
2365 *
2366 */
2367DLLEXPORT void *trace_get_payload_from_tcp(libtrace_tcp_t *tcp,
2368                uint32_t *remaining);
2369
2370/** Gets a pointer to the payload following a UDP header
2371 * @param udp           A pointer to the UDP header
2372 * @param[in,out] remaining Updated with the number of captured bytes remaining
2373 *
2374 * @return A pointer to the UDP payload, or NULL if the UDP header is truncated.
2375 *
2376 * When calling this function, remaining must contain the number of captured
2377 * bytes remaining in the packet starting from the UDP header (including the
2378 * UDP header itself). remaining will be updated to contain the number of
2379 * bytes remaining after the UDP header has been skipped.
2380 *
2381 * If the UDP header is complete but there are zero bytes of payload after
2382 * the UDP header, a pointer to where the payload would be is returned and
2383 * remaining will be set to 0.  If the UDP header is incomplete, NULL will be
2384 * returned and remaining will be set to 0. Therefore, it is important to check
2385 * the value of remaining after calling this function.
2386 *
2387 */
2388DLLEXPORT void *trace_get_payload_from_udp(libtrace_udp_t *udp, uint32_t *remaining);
2389
2390/** Gets a pointer to the payload following a ICMP header
2391 * @param icmp           A pointer to the ICMP header
2392 * @param[in,out] remaining Updated with the number of captured bytes remaining
2393 *
2394 * @return A pointer to the ICMP payload, or NULL if the ICMP header is
2395 * truncated.
2396 *
2397 * When calling this function, remaining must contain the number of captured
2398 * bytes remaining in the packet starting from the ICMP header (including the
2399 * ICMP header itself). remaining will be updated to contain the number of
2400 * bytes remaining after the ICMP header has been skipped.
2401 *
2402 * If the ICMP header is complete but there are zero bytes of payload after
2403 * the ICMP header, a pointer to where the payload would be is returned and
2404 * remaining will be set to 0.  If the ICMP header is incomplete, NULL will be
2405 * returned and remaining will be set to 0. Therefore, it is important to check
2406 * the value of remaining after calling this function.
2407 *
2408 * @note In the case of some ICMP messages, the payload may be the IP header
2409 * from the packet that triggered the ICMP message.
2410 *
2411 */
2412DLLEXPORT void *trace_get_payload_from_icmp(libtrace_icmp_t *icmp,
2413                uint32_t *remaining);
2414
2415/** Gets a pointer to the payload following a ICMPv6 header
2416 * @param icmp           A pointer to the ICMPv6 header
2417 * @param[in,out] remaining Updated with the number of captured bytes remaining
2418 *
2419 * @return A pointer to the ICMPv6 payload, or NULL if the ICMPv6 header is
2420 * truncated.
2421 *
2422 * When calling this function, remaining must contain the number of captured
2423 * bytes remaining in the packet starting from the ICMPv6 header (including the
2424 * ICMP header itself). remaining will be updated to contain the number of
2425 * bytes remaining after the ICMPv6 header has been skipped.
2426 *
2427 * If the ICMPv6 header is complete but there are zero bytes of payload after
2428 * the header, a pointer to where the payload would be is returned and
2429 * remaining will be set to 0.  If the ICMPv6 header is incomplete, NULL will be
2430 * returned and remaining will be set to 0. Therefore, it is important to check
2431 * the value of remaining after calling this function.
2432 *
2433 * @note In the case of some ICMPv6 messages, the payload may be the IP header
2434 * from the packet that triggered the ICMP message.
2435 *
2436 */
2437DLLEXPORT void *trace_get_payload_from_icmp6(libtrace_icmp6_t *icmp,
2438                uint32_t *remaining);
2439
2440/** Gets a pointer to the payload following a GRE header
2441 * @param         gre       A pointer to the beginning of the GRE header.
2442 * @param[in,out] remaining Updated with the number of captured bytes remaining.
2443 *
2444 * @return A pointer to the GRE payload, or NULL if the GRE header is truncated.
2445 *
2446 * When calling this function, remaining must contain the number of captured
2447 * bytes remaining in the packet starting from the GRE header (including the
2448 * GRE header itself). remaining will be updated to contain the number of
2449 * bytes remaining after the GRE header has been skipped.
2450 *
2451 * If the GRE header is complete but there are zero bytes of payload after
2452 * the header, a pointer to where the payload would be is returned and
2453 * remaining will be set to 0.  If the GRE header is incomplete, NULL will be
2454 * returned and remaining will be set to 0. Therefore, it is important to check
2455 * the value of remaining after calling this function.
2456 */
2457DLLEXPORT void *trace_get_payload_from_gre(libtrace_gre_t *gre,
2458                uint32_t *remaining);
2459
2460/** Gets a pointer to the payload following a VXLAN header
2461 * @param         udp       A pointer to the beginning of the UDP header.
2462 * @param[in,out] remaining Updated with the number of captured bytes remaining.
2463 *
2464 * @return A pointer to the beginning of the VXLAN header, or NULL if the UDP
2465 * header is truncated, or this is not a VXLAN packet.
2466 *
2467 */
2468DLLEXPORT libtrace_vxlan_t *trace_get_vxlan_from_udp(libtrace_udp_t *udp,
2469                uint32_t *remaining);
2470
2471/** Gets a pointer to the payload following a VXLAN header
2472 * @param         vxlan       A pointer to the beginning of the VXLAN header.
2473 * @param[in,out] remaining Updated with the number of captured bytes remaining.
2474 *
2475 * @return A pointer to the VXLAN payload, or NULL if the VXLAN header is
2476 * truncated.
2477 *
2478 * When calling this function, remaining must contain the number of captured
2479 * bytes remaining in the packet starting from the VXLAN header (including the
2480 * VXLAN header itself). remaining will be updated to contain the number of
2481 * bytes remaining after the VXLAN header has been skipped.
2482 *
2483 * If the VXLAN header is complete but there are zero bytes of payload after
2484 * the header, a pointer to where the payload would be is returned and
2485 * remaining will be set to 0.  If the VXLAN header is incomplete, NULL will be
2486 * returned and remaining will be set to 0. Therefore, it is important to check
2487 * the value of remaining after calling this function.
2488 */
2489DLLEXPORT void *trace_get_payload_from_vxlan(libtrace_vxlan_t *vxlan,
2490                uint32_t *remaining);
2491
2492/** Get a pointer to the TCP header (if present)
2493 * @param packet        The packet to get the TCP header from
2494 *
2495 * @return A pointer to the TCP header, or NULL if there is not a complete TCP
2496 * header present in the packet.
2497 *
2498 * This is a short-cut function enabling quick and easy access to the TCP
2499 * header if that is all you care about. However, we recommend the use of the
2500 * more generic trace_get_transport() function instead.
2501 *
2502 * @note Unlike trace_get_transport(), this function will return NULL if the
2503 * TCP header is incomplete or truncated.
2504 */
2505DLLEXPORT SIMPLE_FUNCTION
2506libtrace_tcp_t *trace_get_tcp(libtrace_packet_t *packet);
2507
2508/** Get a pointer to the TCP header following an IPv4 header (if present)
2509 * @param ip            The IP header to find the subsequent TCP header for
2510 * @param[in,out] remaining Updated with the number of captured bytes remaining
2511 *
2512 * @return A pointer to the TCP header, or NULL if no TCP header is present in
2513 * the packet.
2514 *
2515 * When calling this function, remaining must contain the number of captured
2516 * bytes remaining in the packet starting from the IP header (including the
2517 * IP header itself). remaining will be updated to contain the number of
2518 * bytes remaining after the IP header has been skipped.
2519 *
2520 * If the IP header is complete but there are zero bytes of payload after
2521 * the IP header, a pointer to where the payload would be is returned and
2522 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
2523 * returned and remaining will be set to 0. Therefore, it is important to check
2524 * the value of remaining after calling this function.
2525 *
2526 * @note This function is rather redundant now that the layer 3 header is
2527 * cached. There should be no performance advantage for the user to call this
2528 * function over just calling trace_get_transport().
2529 *
2530 * @note The last parameter has changed from libtrace2
2531 */
2532DLLEXPORT SIMPLE_FUNCTION
2533libtrace_tcp_t *trace_get_tcp_from_ip(libtrace_ip_t *ip, uint32_t *remaining);
2534
2535/** Get a pointer to the UDP header (if present)
2536 * @param packet        The packet to get the UDP header from
2537 *
2538 * @return A pointer to the UDP header, or NULL if there is not a complete UDP
2539 * header present in the packet.
2540 *
2541 * This is a short-cut function enabling quick and easy access to the UDP
2542 * header if that is all you care about. However, we recommend the use of the
2543 * more generic trace_get_transport() function instead.
2544 *
2545 * @note Unlike trace_get_transport(), this function will return NULL if the
2546 * UDP header is incomplete or truncated.
2547 */
2548DLLEXPORT SIMPLE_FUNCTION
2549libtrace_udp_t *trace_get_udp(libtrace_packet_t *packet);
2550
2551/** Get a pointer to the UDP header following an IPv4 header (if present)
2552 * @param ip            The IP header to find the subsequent UDP header for
2553 * @param[in,out] remaining Updated with the number of captured bytes remaining
2554 *
2555 * @return A pointer to the UDP header, or NULL if no UDP header is present in
2556 * the packet.
2557 *
2558 * When calling this function, remaining must contain the number of captured
2559 * bytes remaining in the packet starting from the IP header (including the
2560 * IP header itself). remaining will be updated to contain the number of
2561 * bytes remaining after the IP header has been skipped.
2562 *
2563 * If the IP header is complete but there are zero bytes of payload after
2564 * the IP header, a pointer to where the payload would be is returned and
2565 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
2566 * returned and remaining will be set to 0. Therefore, it is important to check
2567 * the value of remaining after calling this function.
2568 *
2569 * @note This function is rather redundant now that the layer 3 header is
2570 * cached. There should be no performance advantage for the user to call this
2571 * function over just calling trace_get_transport().
2572 *
2573 * @note The last parameter has changed from libtrace2
2574 */
2575DLLEXPORT SIMPLE_FUNCTION
2576libtrace_udp_t *trace_get_udp_from_ip(libtrace_ip_t *ip,uint32_t *remaining);
2577
2578/** Get a pointer to the ICMP header (if present)
2579 * @param packet        The packet to get the ICMP header from
2580 *
2581 * @return A pointer to the ICMP header, or NULL if there is not a complete
2582 * ICMP header present in the packet.
2583 *
2584 * This is a short-cut function enabling quick and easy access to the ICMP
2585 * header if that is all you care about. However, we recommend the use of the
2586 * more generic trace_get_transport() function instead.
2587 *
2588 * @note Unlike trace_get_transport(), this function will return NULL if the
2589 * ICMP header is incomplete or truncated.
2590 */
2591DLLEXPORT SIMPLE_FUNCTION
2592libtrace_icmp_t *trace_get_icmp(libtrace_packet_t *packet);
2593
2594/** Get a pointer to the ICMPv6 header (if present)
2595 * @param packet        The packet to get the ICMPv6 header from
2596 *
2597 * @return A pointer to the ICMPv6 header, or NULL if there is not a complete
2598 * ICMP header present in the packet.
2599 *
2600 * This is a short-cut function enabling quick and easy access to the ICMPv6
2601 * header if that is all you care about. However, we recommend the use of the
2602 * more generic trace_get_transport() function instead.
2603 *
2604 * @note Unlike trace_get_transport(), this function will return NULL if the
2605 * ICMPv6 header is incomplete or truncated.
2606 */
2607DLLEXPORT SIMPLE_FUNCTION
2608libtrace_icmp6_t *trace_get_icmp6(libtrace_packet_t *packet);
2609
2610/** Get a pointer to the ICMP header following an IPv4 header (if present)
2611 * @param ip            The IP header to find the subsequent ICMP header for
2612 * @param[in,out] remaining Updated with the number of captured bytes remaining
2613 *
2614 * @return A pointer to the ICMP header, or NULL if no UDP header is present in
2615 * the packet.
2616 *
2617 * When calling this function, remaining must contain the number of captured
2618 * bytes remaining in the packet starting from the IP header (including the
2619 * IP header itself). remaining will be updated to contain the number of
2620 * bytes remaining after the IP header has been skipped.
2621 *
2622 * If the IP header is complete but there are zero bytes of payload after
2623 * the IP header, a pointer to where the payload would be is returned and
2624 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
2625 * returned and remaining will be set to 0. Therefore, it is important to check
2626 * the value of remaining after calling this function.
2627 *
2628 * @note This function is rather redundant now that the layer 3 header is
2629 * cached. There should be no performance advantage for the user to call this
2630 * function over just calling trace_get_transport().
2631 *
2632 * @note The last parameter has changed from libtrace2
2633 */
2634DLLEXPORT SIMPLE_FUNCTION
2635libtrace_icmp_t *trace_get_icmp_from_ip(libtrace_ip_t *ip,uint32_t *remaining);
2636
2637/** Get a pointer to the OSPF header (if present)
2638 * @param packet        The packet to get the OSPF header from
2639 * @param[out] version  The OSPF version number
2640 * @param[out] remaining        Updated with the number of captured bytes remaining
2641 * @return A pointer to the start of the OSPF header or NULL if there is no
2642 * complete OSPF header present in the packet
2643 *
2644 * This is a short-cut function enabling quick and easy access to the OSPF
2645 * header. If you only care about the OSPF header, this function may be useful
2646 * but we otherwise recommend the use of the more generic trace_get_transport()
2647 * function instead.
2648 *
2649 * Upon return, 'version' is updated to contain the OSPF version number for the
2650 * packet so that the returned pointer may be cast to the correct type.
2651 * The version parameter MUST contain a valid pointer; it MUST NOT be NULL.
2652 *
2653 * 'remaining' is also set to contain the number of captured bytes remaining
2654 * starting from the pointer returned by this function.
2655 *
2656 * @note Unlike trace_get_transport(), this function will return NULL if the
2657 * OSPF header is incomplete or truncated.
2658 */
2659DLLEXPORT SIMPLE_FUNCTION
2660void *trace_get_ospf_header(libtrace_packet_t *packet, uint8_t *version,
2661                uint32_t *remaining);
2662
2663/** Get a pointer to the contents of the OSPF packet *after* the OSPF header
2664 * @param header        The OSPF header to get the OSPF contents from
2665 * @param[out] ospf_type        The OSPF packet type
2666 * @param[in, out] remaining    Updated with the number of captured bytes remaining
2667 * @return A pointer to the first byte after the OSPF header.
2668 *
2669 * This function returns a void pointer that can be cast appropriately
2670 * based on the ospf_type. For example, if the ospf_type is TRACE_OSPF_HELLO
2671 * then the return pointer should be cast as a libtrace_ospf_hello_v2_t
2672 * structure.
2673 *
2674 * If the OSPF header is truncated, then NULL will be returned. If the OSPF
2675 * contents are missing or truncated, the pointer to the start of the content
2676 * will still be returned so be careful to check the value of remaining.
2677 *
2678 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2679 * packet starting from the beginning of the OSPF header. It will be updated
2680 * to contain the number of bytes remaining from the start of the OSPF contents.
2681 *
2682 * @note This function only works for OSPF version 2 packets.
2683 * @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.
2684 * @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.
2685 *
2686 */
2687DLLEXPORT SIMPLE_FUNCTION
2688void *trace_get_ospf_contents_v2(libtrace_ospf_v2_t *header,
2689                uint8_t *ospf_type, uint32_t *remaining);
2690
2691/** Get a pointer to the start of the first LSA contained within an LS Update packet
2692 * @param ls_update     Pointer to the LS Update header
2693 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2694 * @return A pointer to the first LSA in the packet.
2695 *
2696 * This function simply skips past the LS Update header to provide a suitable
2697 * pointer to pass into trace_get_next_ospf_lsa_v2.
2698 *
2699 * If the OSPF packet is truncated, then NULL will be returned.
2700 *
2701 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2702 * packet starting from the beginning of the LS Update header. It will be
2703 * updated to contain the number of bytes remaining from the start of the
2704 * first LSA.
2705 *
2706 * @note This function only works for OSPF version 2 packets.
2707 * @note trace_get_next_ospf_lsa_v2() should be subsequently used to process the LSAs
2708 */
2709DLLEXPORT SIMPLE_FUNCTION
2710unsigned char *trace_get_first_ospf_lsa_from_update_v2(
2711                libtrace_ospf_ls_update_t *ls_update,
2712                uint32_t *remaining);
2713
2714/** Get a pointer to the start of the first LSA contained within an Database Description packet
2715 * @param db_desc       Pointer to the Database Description header
2716 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2717 * @return A pointer to the first LSA in the packet.
2718 *
2719 * This function simply skips past the Database Description header to provide a
2720 * suitable pointer to pass into trace_get_next_ospf_lsa_header_v2.
2721 *
2722 * If the OSPF packet is truncated, then NULL will be returned.
2723 *
2724 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2725 * packet starting from the beginning of the Database Description header. It
2726 * will be updated to contain the number of bytes remaining from the start of
2727 * the first LSA.
2728 *
2729 * @note This function only works for OSPF version 2 packets.
2730 * @note trace_get_next_ospf_lsa_header_v2() should be subsequently used to process the LSA headers
2731 */
2732DLLEXPORT SIMPLE_FUNCTION
2733unsigned char *trace_get_first_ospf_lsa_from_db_desc_v2(
2734                libtrace_ospf_db_desc_v2_t *db_desc,
2735                uint32_t *remaining);
2736
2737/** Get a pointer to the start of the first link contained within a Router LSA
2738 * @param lsa   Pointer to the Router LSA
2739 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2740 * @return A pointer to the first link in the packet.
2741 *
2742 * This function simply skips past the Router LSA header to provide a
2743 * suitable pointer to pass into trace_get_next_ospf_link_v2.
2744 *
2745 * If the OSPF packet is truncated, then NULL will be returned.
2746 *
2747 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2748 * packet starting from the beginning of the Router LSA (not including the LSA
2749 * header) header. It will be updated to contain the number of bytes remaining
2750 * from the start of the first Link.
2751 *
2752 * @note This function only works for OSPF version 2 packets.
2753 * @note trace_get_next_ospf_link_v2() should be subsequently used to process
2754 * the links
2755 */
2756DLLEXPORT SIMPLE_FUNCTION
2757unsigned char *trace_get_first_ospf_link_from_router_lsa_v2(
2758                libtrace_ospf_router_lsa_v2_t *lsa,
2759                uint32_t *remaining);
2760
2761/** Parses an OSPF Router LSA Link and finds the next Link (if there is one)
2762 * @param[in,out] current       Pointer to the next Link (updated by this function)
2763 * @param[out] link             Set to point to the Link located at the original value of current
2764 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2765 * @param[out] link_len         Set to the size of the Link pointed to by 'link'
2766 * @return 0 if there are no more links after the current one, 1 otherwise.
2767 *
2768 * When called, 'current' MUST point to an OSPF Router LSA link. Ideally, this
2769 * would come from either a call to
2770 * trace_get_first_ospf_link_from_router_lsa_v2() or a previous call of this
2771 * function.
2772 *
2773 * 'link' will be set to the value of 'current', so that the caller may then
2774 * do any processing they wish on that particular link. 'current' is advanced
2775 * to point to the next link and 'link_len' is updated to report the size of
2776 * the original link.
2777 *
2778 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2779 * packet starting from the beginning of the Link pointed to by 'current'.
2780 * It will be updated to contain the number of bytes remaining from the start
2781 * of the next link.
2782 *
2783 * If this function returns 0 but 'link' is NOT NULL, that link is still valid
2784 * but there are no more links after this one.
2785 * If this function returns 0 AND link is NULL, the link is obviously not
2786 * suitable for processing.
2787 *
2788 * @note This function only works for OSPF version 2 packets.
2789 */
2790DLLEXPORT SIMPLE_FUNCTION
2791int trace_get_next_ospf_link_v2(unsigned char **current,
2792                libtrace_ospf_link_v2_t **link,
2793                uint32_t *remaining,
2794                uint32_t *link_len);
2795
2796/** Parses an OSPF LSA and finds the next LSA (if there is one)
2797 * @param[in,out] current       Pointer to the next LSA (updated by this function)
2798 * @param[out] lsa_hdr          Set to point to the header of the LSA located at the original value of current
2799 * @param[out] lsa_body         Set to point to the body of the LSA located at the original value of current
2800 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2801 * @param[out] lsa_type         Set to the type of the LSA located at the original value of current
2802 * @param[out] lsa_length       Set to the size of the LSA located at the original value of current
2803 * @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.
2804 *
2805 * When called, 'current' MUST point to an OSPF LSA. Ideally, this would come
2806 * from either a call to trace_get_first_ospf_lsa_from_update_v2() or a
2807 * previous call of this function.
2808 *
2809 * This function should only be used to access COMPLETE LSAs, i.e. LSAs that
2810 * have both a header and a body. In OSPFv2, only the LSAs contained within
2811 * LSA Update packets meet this requirement. trace_get_next_ospf_lsa_header_v2
2812 * should be used to read header-only LSAs, e.g. those present in LS Acks.
2813 *
2814 * 'lsa_hdr' will be set to the value of 'current', so that the caller may then
2815 * do any processing they wish on that particular LSA. 'lsa_body' will be set
2816 * to point to the first byte after the LSA header. 'current' is advanced
2817 * to point to the next LSA. 'lsa_length' is updated to contain the size of
2818 * the parsed LSA, while 'lsa_type' is set to indicate the LSA type.
2819 *
2820 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2821 * packet starting from the beginning of the LSA pointed to by 'current'.
2822 * It will be updated to contain the number of bytes remaining from the start
2823 * of the next LSA.
2824 *
2825 * If this function returns 0 but 'lsa_hdr' is NOT NULL, that LSA is still
2826 * valid but there are no more LSAs after this one.
2827 * If this function returns 0 AND 'lsa_hdr' is NULL, the LSA is obviously not
2828 * suitable for processing.
2829 *
2830 * It is also recommended to check the value of 'lsa_body' before
2831 * de-referencing it. 'lsa_body' will be set to NULL if there is only an LSA
2832 * header present.
2833 *
2834 * @note This function only works for OSPF version 2 packets.
2835 *
2836 */
2837DLLEXPORT SIMPLE_FUNCTION
2838int trace_get_next_ospf_lsa_v2(unsigned char **current,
2839                libtrace_ospf_lsa_v2_t **lsa_hdr,
2840                unsigned char **lsa_body,
2841                uint32_t *remaining,
2842                uint8_t *lsa_type,
2843                uint16_t *lsa_length);
2844
2845/** Parses an OSPF LSA header and finds the next LSA (if there is one)
2846 * @param[in,out] current       Pointer to the next LSA (updated by this function)
2847 * @param[out] lsa_hdr          Set to point to the header of the LSA located at the original value of current
2848 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2849 * @param[out] lsa_length       Set to the size of the LSA located at the original value of current
2850 * @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.
2851 *
2852 * When called, 'current' MUST point to an OSPF LSA. Ideally, this would come
2853 * from either a call to trace_get_first_ospf_lsa_from_db_desc_v2() or a
2854 * previous call of this function.
2855 *
2856 * This function should only be used to access LSA headers, i.e. LSAs that
2857 * have a header only. In OSPFv2, the LSAs contained within LSA Ack and
2858 * Database Description packets meet this requirement.
2859 * trace_get_next_ospf_lsa_v2 should be used to read full LSAs, e.g. those
2860 * present in LS Updates.
2861 *
2862 * 'lsa_hdr' will be set to the value of 'current', so that the caller may then
2863 * do any processing they wish on that particular LSA header. 'current' is
2864 * advanced to point to the next LSA header. 'lsa_length' is updated to contain
2865 * the size of the parsed LSA header.
2866 *
2867 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2868 * packet starting from the beginning of the LSA pointed to by 'current'.
2869 * It will be updated to contain the number of bytes remaining from the start
2870 * of the next LSA.
2871 *
2872 * If this function returns 0 but 'lsa_hdr' is NOT NULL, that LSA is still
2873 * valid but there are no more LSAs after this one.
2874 * If this function returns 0 AND 'lsa_hdr' is NULL, the LSA is obviously not
2875 * suitable for processing.
2876 *
2877 * @note This function only works for OSPF version 2 packets.
2878 *
2879 */
2880DLLEXPORT SIMPLE_FUNCTION
2881int trace_get_next_ospf_lsa_header_v2(unsigned char **current,
2882                libtrace_ospf_lsa_v2_t **lsa_hdr,
2883                uint32_t *remaining,
2884                uint8_t *lsa_type,
2885                uint16_t *lsa_length);
2886
2887/** Extracts the metric field from an AS External LSA packet
2888 *
2889 * @param as_lsa        The AS External LSA
2890 * @returns The value of the metric field
2891 *
2892 * The metric field in the AS External LSA packet is a 24-bit value, which
2893 * is difficult to extract correctly. To avoid byte-ordering issues, use this
2894 * function which will extract the correct value for you.
2895 */
2896DLLEXPORT SIMPLE_FUNCTION
2897uint32_t trace_get_ospf_metric_from_as_external_lsa_v2(
2898                libtrace_ospf_as_external_lsa_v2_t *as_lsa);
2899
2900/** Extracts the metric field from a Summary LSA packet
2901 *
2902 * @param sum_lsa       The Summary LSA
2903 * @returns The value of the metric field
2904 *
2905 * The metric field in the Summary LSA packet is a 24-bit value, which
2906 * is difficult to extract correctly. To avoid byte-ordering issues, use this
2907 * function which will extract the correct value for you.
2908 */
2909DLLEXPORT SIMPLE_FUNCTION
2910uint32_t trace_get_ospf_metric_from_summary_lsa_v2(
2911                libtrace_ospf_summary_lsa_v2_t *sum_lsa);
2912
2913
2914/** Gets the destination MAC address for a given packet
2915 * @param packet        The packet to extract the destination MAC address from
2916 *
2917 * @return A pointer to the destination MAC address field in the layer 2
2918 * header, (or NULL if there is no destination MAC address or layer 2 header
2919 * available)
2920 *
2921 * @note This is a zero-copy function, so the memory that the returned pointer
2922 * points to is part of the packet itself.
2923 */
2924DLLEXPORT SIMPLE_FUNCTION
2925uint8_t *trace_get_destination_mac(libtrace_packet_t *packet);
2926
2927/** Gets the source MAC address for a given packet
2928 * @param packet        The packet to extract the source MAC address from
2929 *
2930 * @return A pointer to the source MAC address field in the layer 2
2931 * header, (or NULL if there is no source MAC address or layer 2 header
2932 * available)
2933 *
2934 * @note This is a zero-copy function, so the memory that the returned pointer
2935 * points to is part of the packet itself.
2936 */
2937DLLEXPORT SIMPLE_FUNCTION
2938uint8_t *trace_get_source_mac(libtrace_packet_t *packet);
2939
2940/** Get the source IP address for a given packet
2941 * @param packet        The packet to extract the source IP address from
2942 * @param addr          A pointer to a sockaddr structure to store the address
2943 *                      in. If NULL, static storage is used instead.
2944 * @return A pointer to a sockaddr holding a v4 or v6 IP address or on some
2945 * platforms a sockaddr holding a MAC address. Returns NULL if no source IP
2946 * address was available.
2947 *
2948 * @note The best way to use this function is to pass in a pointer to the
2949 * struct sockaddr_storage for the addr parameter. This will avoid problems
2950 * with trying to shoe-horn an IPv6 address into a sockaddr that only supports
2951 * IPv4.
2952 */
2953DLLEXPORT SIMPLE_FUNCTION
2954struct sockaddr *trace_get_source_address(const libtrace_packet_t *packet,
2955                struct sockaddr *addr);
2956
2957/** Get the source IP address for a packet and convert it into a string
2958 * @param packet        The packet to extract the source IP address from
2959 * @param space         A pointer to a character buffer to store the address
2960 *                      in. If NULL, static storage is used instead.
2961 * @param spacelen      The size of the buffer passed in via 'space'. Set this
2962 *                      to zero if you are going to pass in a NULL buffer.
2963 * @return A pointer to a character buffer containing the string representation
2964 * of the source IP address. For packets where there is no suitable IP address,
2965 * the source MAC will be returned instead. Returns NULL if no valid address
2966 * is available.
2967 *
2968 * @note Be wary of the possibility of the address being an IPv6 address - make
2969 * sure your buffer is large enough!
2970 *
2971 * New in libtrace 3.0.17.
2972 */
2973DLLEXPORT SIMPLE_FUNCTION
2974char *trace_get_source_address_string(const libtrace_packet_t *packet,
2975                char *space, int spacelen);
2976
2977/** Get the destination IP address for a given packet
2978 * @param packet        The packet to extract the destination IP address from
2979 * @param addr          A pointer to a sockaddr structure to store the address
2980 *                      in. If NULL, static storage is used instead.
2981 * @return A pointer to a sockaddr holding a v4 or v6 IP address or on some
2982 * platforms a sockaddr holding a MAC address. Returns NULL if no destination
2983 * IP address was available.
2984 *
2985 * @note The best way to use this function is to pass in a pointer to the
2986 * struct sockaddr_storage for the addr parameter. This will avoid problems
2987 * with trying to shoe-horn an IPv6 address into a sockaddr that only supports
2988 * IPv4.
2989 */
2990DLLEXPORT SIMPLE_FUNCTION
2991struct sockaddr *trace_get_destination_address(const libtrace_packet_t *packet,
2992                struct sockaddr *addr);
2993
2994/** Get the destination IP address for a packet and convert it into a string
2995 * @param packet        The packet to extract the destination IP address from
2996 * @param space         A pointer to a character buffer to store the address
2997 *                      in. If NULL, static storage is used instead.
2998 * @param spacelen      The size of the buffer passed in via 'space'. Set this
2999 *                      to zero if you are going to pass in a NULL buffer.
3000 * @return A pointer to a character buffer containing the string representation
3001 * of the destination IP address. For packets where there is no suitable IP
3002 * address, the destination MAC will be returned instead. Returns NULL if no
3003 * valid address is available.
3004 *
3005 * @note Be wary of the possibility of the address being an IPv6 address - make
3006 * sure your buffer is large enough!
3007 *
3008 * New in libtrace 3.0.17.
3009 */
3010DLLEXPORT SIMPLE_FUNCTION
3011char *trace_get_destination_address_string(const libtrace_packet_t *packet,
3012                char *space, int spacelen);
3013
3014/** Parses an IP or TCP option
3015 * @param[in,out] ptr   The pointer to the current option
3016 * @param[in,out] len   The total length of all the remaining options
3017 * @param[out] type     The type of the option
3018 * @param[out] optlen   The length of the option
3019 * @param[out] data     The data of the option
3020 *
3021 * @return bool true if there is another option (and the fields are filled in)
3022 *               or false if this was the last option.
3023 *
3024 * This updates ptr to point to the next option after this one, and updates
3025 * len to be the number of bytes remaining in the options area.  Type is updated
3026 * to be the code of this option, and data points to the data of this option,
3027 * with optlen saying how many bytes there are.
3028 *
3029 * @note Beware of fragmented packets.
3030 */
3031DLLEXPORT int trace_get_next_option(unsigned char **ptr,int *len,
3032                        unsigned char *type,
3033                        unsigned char *optlen,
3034                        unsigned char **data);
3035
3036/*@}*/
3037
3038/** @name Time
3039 * These functions deal with the timestamp describing when a packet was
3040 * captured and can convert it into various formats
3041 * @{
3042 */
3043
3044/** Get the packet timestamp in the DAG time format
3045 * @param packet        The packet to extract the timestamp from
3046 *
3047 * @return a 64 bit timestamp in DAG ERF format (upper 32 bits are the seconds
3048 * past 1970-01-01, the lower 32bits are partial seconds)
3049 */
3050DLLEXPORT SIMPLE_FUNCTION
3051uint64_t trace_get_erf_timestamp(const libtrace_packet_t *packet);
3052
3053/** Get the packet timestamp as a struct timeval
3054 * @param packet        The packet to extract the timestamp from
3055 *
3056 * @return The time that this packet was captured in a struct timeval
3057 */
3058DLLEXPORT SIMPLE_FUNCTION
3059struct timeval trace_get_timeval(const libtrace_packet_t *packet);
3060
3061/** Get the packet timestamp as a struct timespec
3062 * @param packet        The packet to extract the timestamp from
3063 *
3064 * @return The time that this packet was captured in a struct timespec
3065 */
3066DLLEXPORT SIMPLE_FUNCTION
3067struct timespec trace_get_timespec(const libtrace_packet_t *packet);
3068
3069/** Get the packet timestamp in floating point seconds
3070 * @param packet        The packet to extract the timestamp from
3071 *
3072 * @return time that this packet was seen in 64-bit floating point seconds from
3073 * the UNIX epoch (1970-01-01 00:00:00 UTC).
3074 */
3075DLLEXPORT SIMPLE_FUNCTION
3076double trace_get_seconds(const libtrace_packet_t *packet);
3077
3078/** Seek within an input trace to a time specified in floating point seconds
3079 * @param trace         The input trace to seek within
3080 * @param seconds       The time to seek to, in floating point seconds
3081 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
3082 * the error that occurred.
3083 *
3084 * This will make the next packet read to be the first packet to occur at or
3085 * after the specified time.  This must be called in the configuration state
3086 * (i.e. before trace_start() or after trace_pause()).
3087 *
3088 * The time format accepted by this function is 64-bit floating point seconds
3089 * since the UNIX epoch (1970-01-01 00:00:00 UTC), i.e. the same format as
3090 * trace_get_seconds().
3091 *
3092 * @note This function may be extremely slow.
3093 */
3094DLLEXPORT int trace_seek_seconds(libtrace_t *trace, double seconds);
3095
3096/** Seek within an input trace to a time specified as a timeval
3097 * @param trace         The input trace to seek within
3098 * @param tv            The time to seek to, as a timeval
3099 *
3100 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
3101 * the error that occurred.
3102 *
3103 * This will make the next packet read to be the first packet to occur at or
3104 * after the specified time.  This must be called in the configuration state
3105 * (i.e. before trace_start() or after trace_pause()).
3106 *
3107 * @note This function may be extremely slow.
3108 */
3109DLLEXPORT int trace_seek_timeval(libtrace_t *trace, struct timeval tv);
3110
3111/** Seek within an input trace to a time specified as an ERF timestamp
3112 * @param trace         The input trace to seek within
3113 * @param ts            The time to seek to, as an ERF timestamp
3114 *
3115 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
3116 * the error that occurred.
3117 *
3118 * This will make the next packet read to be the first packet to occur at or
3119 * after the specified time.  This must be called in the configuration state
3120 * (i.e. before trace_start() or after trace_pause()).
3121 *
3122 * The time format accepted by this function is the ERF timestamp, which is a
3123 * 64-bit value where the upper 32 bits are seconds since the UNIX epoch and
3124 * the lower 32 bits are partial seconds.
3125 *
3126 * @note This function may be extremely slow.
3127 */
3128DLLEXPORT int trace_seek_erf_timestamp(libtrace_t *trace, uint64_t ts);
3129
3130/*@}*/
3131
3132/** @name Sizes
3133 * This section deals with finding or setting the various different lengths
3134 * that a packet can have, e.g. capture lengths, wire lengths, etc.
3135 * @{
3136 */
3137/** Get the current size of the packet (in bytes), taking into account any
3138 * truncation or snapping that may have previously been performed.
3139 *
3140 * @param packet        The packet to determine the capture length for
3141 * @return The size of the packet read from the input trace, i.e. what is
3142 * actually available to libtrace at the moment.
3143 *
3144 * @note Most traces are header captures, so this value may not be the same
3145 * as the size of the packet when it was captured. Use trace_get_wire_length()
3146 * to get the original size of the packet.
3147 
3148 * @note This can (and often is) different for different packets in a trace!
3149 
3150 * @note This is sometimes called the "snaplen".
3151 *
3152 * @note The return size refers to the network-level payload of the packet and
3153 * does not include any capture framing headers. For example, an Ethernet
3154 * packet with an empty TCP packet will return sizeof(ethernet_header) +
3155 * sizeof(ip_header) + sizeof(tcp_header), but not the capture format
3156 * (pcap/erf/etc) header.
3157 */
3158DLLEXPORT SIMPLE_FUNCTION
3159size_t trace_get_capture_length(const libtrace_packet_t *packet);
3160
3161/** Get the size of the packet as it was originally seen on the wire (in bytes).
3162 * @param packet        The packet to determine the wire length for
3163 * @return The size of the packet as it was on the wire.
3164 *
3165 * @note This value may not be the same as the capture length, due to
3166 * truncation.
3167 *
3168 * @note trace_get_wire_length \em includes  the Frame Check Sequence. This is
3169 * different behaviour compared to most PCAP-based tools.
3170 *
3171 * @note The return size refers to the network-level payload of the packet and
3172 * does not include any capture framing headers. For example, an Ethernet
3173 * packet with an empty TCP packet will return sizeof(ethernet_header) +
3174 * sizeof(ip_header) + sizeof(tcp_header), but not the capture format
3175 * (pcap/erf/etc) header.
3176 */
3177DLLEXPORT SIMPLE_FUNCTION
3178size_t trace_get_wire_length(const libtrace_packet_t *packet);
3179
3180/** Get the length of the capture framing headers (in bytes).
3181 * @param packet        The packet to determine the framing length for
3182 * @return The size of the capture format header encapsulating the packet.
3183 *
3184 * @note This length corresponds to the difference between the amount of
3185 * memory required to store a captured packet and the capture length reported
3186 * by trace_capture_length()
3187 */
3188DLLEXPORT SIMPLE_FUNCTION
3189size_t trace_get_framing_length(const libtrace_packet_t *packet);
3190
3191/** Get the length of the original payload content of the packet (in bytes).
3192 * @param packet        The packet to determine the payload length for
3193 * @return The size of the packet payload (without headers). Returns 0 if
3194 * unable to calculate payload length correctly.
3195 *
3196 * This function reports the amount of data that followed the transport header
3197 * when the packet was originally captured, i.e. prior to any snapping. Best
3198 * described as the wire length minus the packet headers.
3199 *
3200 * Currently only supports some protocols and will return 0 if an unsupported
3201 * protocol header is encountered, or if one of the headers is truncated.
3202 *
3203 * @note Supports IPv4, IPv6, TCP, UDP and ICMP.
3204 */
3205DLLEXPORT SIMPLE_FUNCTION
3206size_t trace_get_payload_length(const libtrace_packet_t *packet);
3207
3208/** Truncate ("snap") the packet to the suggested length
3209 * @param packet        The packet to truncate
3210 * @param size          The new length of the packet (in bytes)
3211 *
3212 * @return The new capture length of the packet or the original capture
3213 * length of the packet if unchanged.
3214 *
3215 * This function will modify the capture length of the given packet. The wire
3216 * length will not be changed, so you can always determine what the original
3217 * packet size was, prior to the truncation.
3218 *
3219 * @note You can only use this function to decrease the capture length. Any
3220 * attempt to increase capture length will have no effect.
3221 */
3222DLLEXPORT size_t trace_set_capture_length(libtrace_packet_t *packet, size_t size);
3223
3224/*@}*/
3225
3226
3227/** Gets the link layer type for a packet
3228 * @param packet        The packet to extract the link layer type for
3229 * @return A libtrace_linktype_t describing the link layer protocol being used
3230 * by this packet.
3231 */
3232DLLEXPORT SIMPLE_FUNCTION
3233libtrace_linktype_t trace_get_link_type(const libtrace_packet_t *packet);
3234
3235/** Set the direction flag for a packet, if the capture format supports
3236 * direction tagging.
3237 *
3238 * @param packet        The packet to set the direction for
3239 * @param direction     The new direction
3240 * @returns -1 on error, or the direction that was set.
3241 *
3242 * @note Few capture formats actually support direction tagging. Most notably,
3243 * we cannot set the direction on PCAP packets.
3244 */
3245DLLEXPORT libtrace_direction_t trace_set_direction(libtrace_packet_t *packet, libtrace_direction_t direction);
3246
3247/** Get the direction flag for a packet, if it has one.
3248 * @param packet  The packet to get the direction for
3249 *
3250 * @return A value representing the direction flag, or -1 if this is not
3251 * supported by the capture format.
3252 *
3253 * The direction is defined as 0 for packets originating locally (ie, outbound)
3254 * and 1 for packets originating remotely (ie, inbound). Other values are
3255 * possible, which might be overloaded to mean special things for certain
3256 * traces, e.g. in the Waikato traces, 2 is used to represent an "Unknown"
3257 * direction.
3258 *
3259 * For DAG/ERF traces, the direction is extracted from the "Interface" bits in
3260 * the ERF header, which can range from 0 - 3.
3261 */
3262DLLEXPORT SIMPLE_FUNCTION
3263libtrace_direction_t trace_get_direction(const libtrace_packet_t *packet);
3264
3265/** @name BPF
3266 * This section deals with using Berkley Packet Filters to filter input traces
3267 * @{
3268 */
3269/** Creates a BPF filter
3270 * @param filterstring The filter string describing the BPF filter to create
3271 * @return An opaque pointer to a libtrace_filter_t object
3272 *
3273 * @note The filter is not actually compiled at this point, so no correctness
3274 * tests are performed here. trace_create_filter() will always return ok, but
3275 * if the filter is poorly constructed an error will be generated when the
3276 * filter is actually used.
3277 */
3278DLLEXPORT SIMPLE_FUNCTION
3279libtrace_filter_t *trace_create_filter(const char *filterstring);
3280
3281/** Create a BPF filter based on pre-compiled byte-code.
3282 * @param bf_insns      A pointer to the start of the byte-code
3283 * @param bf_len        The number of BPF instructions 
3284 * @return              An opaque pointer to a libtrace_filter_t object
3285 * @note                The supplied byte-code is not checked for correctness.
3286 *                      Instead, incorrect byte-code will generate an error
3287 *                      once the filter is actually used.
3288 * @author              Scott Raynel
3289 */
3290DLLEXPORT libtrace_filter_t *
3291trace_create_filter_from_bytecode(void *bf_insns, unsigned int bf_len);
3292
3293/** Apply a BPF filter to a packet
3294 * @param filter        The filter to be applied       
3295 * @param packet        The packet to be matched against the filter
3296 * @return >0 if the filter matches, 0 if it doesn't, -1 on error.
3297 *
3298 * @note Due to the way BPF filters are built, the filter is not actually
3299 * compiled until the first time trace_create_filter is called. If your filter
3300 * is incorrect, it will generate an error message and assert, exiting the
3301 * program. This behaviour may change to a more graceful handling of this error
3302 * in the future.
3303 */
3304DLLEXPORT int trace_apply_filter(libtrace_filter_t *filter,
3305                const libtrace_packet_t *packet);
3306
3307/** Destroy a BPF filter
3308 * @param filter        The filter to be destroyed
3309 *
3310 * Deallocates all the resources associated with a BPF filter.
3311 */
3312DLLEXPORT void trace_destroy_filter(libtrace_filter_t *filter);
3313/*@}*/
3314
3315/** @name Portability
3316 * This section contains functions that deal with portability issues, e.g. byte
3317 * ordering.
3318 * @{
3319 */
3320
3321/** Converts an ethernet address to a printable string
3322 * @param addr  Ethernet address in network byte order
3323 * @param buf   Buffer to store the ascii representation, or NULL to indicate
3324 * that static storage should be used.
3325 * @return buf, or if buf is NULL then a statically allocated buffer.
3326 *
3327 * This function is similar to the GNU ether_ntoa_r function, with a few
3328 * minor differences.  If NULL is passed as buf, then the function will
3329 * use an internal static buffer. If NULL isn't passed then the function
3330 * will use that buffer instead.
3331 *
3332 * The address pointers returned by trace_get_source_mac() and
3333 * trace_get_destination_mac() can be passed directly into this function.
3334 *
3335 * @note The type of addr isn't struct ether_addr as it is with ether_ntoa_r,
3336 * however it is bit compatible so that a cast will work.
3337 */
3338DLLEXPORT char *trace_ether_ntoa(const uint8_t *addr, char *buf);
3339
3340/** Convert a string to an ethernet address
3341 * @param buf   A string containing an Ethernet address in hex format
3342 * delimited with :'s.
3343 * @param addr  Buffer to store the binary representation, or NULL to indicate
3344 * that static storage should be used.
3345 * @return addr, or if addr is NULL then a statically allocated buffer.
3346 *
3347 * This function is similar to the GNU ether_aton_r function, with a few
3348 * minor differences.  If NULL is passed as addr, then the function will
3349 * use an internal static buffer. If NULL isn't passed then the function will
3350 * use that buffer instead.
3351 *
3352 * The address returned by this function will be in network byte order.
3353 *
3354 * @note the type of addr isn't struct ether_addr as it is with ether_aton_r,
3355 * however it is bit compatible so that a cast will work.
3356 */
3357DLLEXPORT uint8_t *trace_ether_aton(const char *buf, uint8_t *addr);
3358
3359/*@}*/
3360
3361/** @name Ports
3362 * This section contains functions for dealing with port numbers at the
3363 * transport layer.
3364 *
3365 * @{
3366 */
3367
3368/** An indication of which port is the "server" port for a given port pair */
3369typedef enum {
3370        USE_DEST,       /**< Destination port is the server port */
3371        USE_SOURCE      /**< Source port is the server port */
3372} serverport_t;
3373
3374/** Gets the source port for a given packet
3375 * @param packet        The packet to get the source port from
3376 * @return The source port in HOST byte order or 0 if no suitable port number
3377 * can be extracted from the packet.
3378 *
3379 * This function will return 0 if the transport protocol is known not to
3380 * use port numbers, e.g. ICMP. 0 is also returned if no transport header is
3381 * present in the packet or the transport header has been truncated such that
3382 * the port fields are not readable.
3383 *
3384 * @note If the transport protocol is not known by libtrace, the first two
3385 * bytes of the transport header will be treated as the source port field.
3386 */
3387DLLEXPORT SIMPLE_FUNCTION
3388uint16_t trace_get_source_port(const libtrace_packet_t *packet);
3389
3390/** Gets the destination port for a given packet
3391 * @param packet        The packet to get the destination port from
3392 * @return The destination port in HOST byte order or 0 if no suitable port
3393 * number can be extracted from the packet.
3394 *
3395 * This function will return 0 if the transport protocol is known not to
3396 * use port numbers, e.g. ICMP. 0 is also returned if no transport header is
3397 * present in the packet or the transport header has been truncated such that
3398 * the port fields are not readable.
3399 *
3400 * @note If the transport protocol is not known by libtrace, the third and
3401 * fourth bytes of the transport header will be treated as the destination
3402 * port field.
3403 *
3404 */
3405DLLEXPORT SIMPLE_FUNCTION
3406uint16_t trace_get_destination_port(const libtrace_packet_t *packet);
3407
3408/** Hint at which of the two provided ports is the server port.
3409 *
3410 * @param protocol      The IP layer protocol, eg 6 (tcp), 17 (udp)
3411 * @param source        The source port from the packet
3412 * @param dest          The destination port from the packet
3413 *
3414 * @return one of USE_SOURCE or USE_DEST describing on which of the two ports
3415 * is most likely to be the server port.
3416 *
3417 * @note Ports must be provided in HOST byte order!
3418 *
3419 * This function is based almost entirely on heuristics and should not be
3420 * treated as a definitive means of identifying the server port. However, it
3421 * is deterministic, so it is very handy for identifying both halves of the
3422 * same flow.
3423 */
3424DLLEXPORT SIMPLE_FUNCTION
3425int8_t trace_get_server_port(uint8_t protocol, uint16_t source, uint16_t dest);
3426
3427/*@}*/
3428
3429/** @name Wireless trace support
3430 * Functions to access wireless information from packets that have wireless
3431 * monitoring headers such as Radiotap or Prism.
3432 *
3433 * The trace_get_wireless_* functions provide an abstract interface for
3434 * retrieving information from wireless traces. They take a pointer to the
3435 * wireless monitoring header (usually found with trace_get_packet_meta()) and
3436 * the linktype of the header passed in.
3437 *
3438 * All of the trace_get_wireless_* functions return false if the requested
3439 * information was unavailable, or true if it was. The actual data is stored
3440 * in an output variable supplied by the caller. Values returned into the
3441 * output variable will always be returned in host byte order.
3442 * @{
3443 */
3444
3445
3446#ifndef ARPHRD_80211_RADIOTAP
3447/** libc doesn't define this yet, so we have to do so ourselves */
3448#define ARPHRD_80211_RADIOTAP 803
3449#endif
3450
3451/** Get the wireless Timer Synchronisation Function
3452 *
3453 * Gets the value of the timer synchronisation function for this frame, which
3454 * is a value in microseconds indicating the time that the first bit of the
3455 * MPDU was received by the MAC.
3456 *
3457 * @param linkptr The wireless meta header
3458 * @param linktype The linktype of the wireless meta header passed in
3459 * @param[out] tsft The value of the timer synchronisation function.
3460 * @return true if the field was available, false if not.
3461 */
3462DLLEXPORT bool trace_get_wireless_tsft(void *linkptr,
3463        libtrace_linktype_t linktype, uint64_t *tsft);
3464
3465/** Get the wireless data rate
3466 *
3467 * @param linkptr The wireless meta header
3468 * @param linktype The linktype of the wireless meta header passed in
3469 * @param[out] rate The data-rate of the frame in units of 500kbps
3470 * @return true if the field was available, false if not.
3471 */
3472DLLEXPORT bool trace_get_wireless_rate(void *linkptr,
3473        libtrace_linktype_t linktype, uint8_t *rate);
3474
3475/** Get the wireless channel frequency
3476 * @param linkptr The wireless meta header
3477 * @param linktype The linktype of the wireless meta header passed in
3478 * @param[out] freq The frequency in MHz of the channel the frame was
3479 * transmitted or received on.
3480 * @return true if the field was available, false if not.
3481 */
3482DLLEXPORT bool trace_get_wireless_freq(void *linkptr,
3483        libtrace_linktype_t linktype, uint16_t *freq);
3484
3485/** Get the wireless signal strength in dBm
3486 * @param linkptr The wireless meta header
3487 * @param linktype The linktype of the wireless meta header passed in
3488 * @param[out] strength The RF signal power at the antenna, in dB difference
3489 * from 1mW.
3490 * @return true if the field was available, false if not.
3491 */
3492DLLEXPORT bool trace_get_wireless_signal_strength_dbm(void *linkptr,
3493        libtrace_linktype_t linktype, int8_t *strength);
3494
3495/** Get the wireless noise strength in dBm
3496 * @param linkptr The wireless meta header
3497 * @param linktype The linktype of the wireless meta header passed in
3498 * @param[out] strength The RF noise power at the antenna, in dB difference
3499 * from 1mW.
3500 * @return true if the field was available, false if not.
3501 */
3502DLLEXPORT bool trace_get_wireless_noise_strength_dbm(void *linkptr,
3503        libtrace_linktype_t linktype, int8_t *strength);
3504
3505/** Get the wireless signal strength in dB
3506 * @param linkptr The wireless meta header
3507 * @param linktype The linktype of the wireless meta header passed in
3508 * @param[out] strength The RF signal power at the antenna, in dB difference
3509 * from a fixed reference.
3510 * @return true if the field was available, false if not.
3511 */
3512DLLEXPORT bool trace_get_wireless_signal_strength_db(void *linkptr,
3513        libtrace_linktype_t linktype, uint8_t *strength);
3514
3515/** Get the wireless noise strength in dB
3516 * @param linkptr The wireless meta header
3517 * @param linktype The linktype of the wireless meta header passed in
3518 * @param[out] strength The RF noise power at the antenna, in dB difference
3519 * from a fixed reference.
3520 * @return true if the field was available, false if not.
3521 */
3522DLLEXPORT bool trace_get_wireless_noise_strength_db(void *linkptr,
3523        libtrace_linktype_t linktype, uint8_t *strength);
3524
3525/** Get the wireless transmit attenuation
3526 * @param linkptr The wireless meta header
3527 * @param linktype The linktype of the wireless meta header passed in
3528 * @param[out] attenuation The transmit power as a unitless distance from
3529 * maximum power set at factory calibration. 0 indicates maximum transmission
3530 * power.
3531 * @return true if the field was available, false if not.
3532 */
3533DLLEXPORT bool trace_get_wireless_tx_attenuation(void *linkptr,
3534        libtrace_linktype_t linktype, uint16_t *attenuation);
3535
3536/** Get the wireless transmit attenuation in dB
3537 * @param linkptr The wireless meta header
3538 * @param linktype The linktype of the wireless meta header passed in
3539 * @param[out] attenuation The transmit power as dB difference from maximum
3540 * power set at factory calibration. 0 indicates maximum power.
3541 * @return true if the field was available, false if not.
3542 */
3543DLLEXPORT bool trace_get_wireless_tx_attenuation_db(void *linkptr,
3544        libtrace_linktype_t linktype, uint16_t *attenuation);
3545
3546/** Get the wireless transmit power in dBm
3547 * @param linkptr The wireless meta header
3548 * @param linktype The linktype of the wireless meta header passed in
3549 * @param[out] txpower The transmit power as dB from a 1mW reference. This is
3550 * the absolute power level measured at the antenna port. 
3551 * @return true if the field was available, false if not.
3552 */
3553DLLEXPORT bool trace_get_wireless_tx_power_dbm(void *linkptr,
3554                libtrace_linktype_t linktype, int8_t *txpower);
3555
3556/** Get the wireless antenna
3557 * @param linkptr The wireless meta header
3558 * @param linktype The linktype of the wireless meta header passed in
3559 * @param[out] antenna The antenna that was used to transmit or receive the
3560 * frame.
3561 * @return true if the field was available, false if not.
3562 */
3563DLLEXPORT bool trace_get_wireless_antenna(void *linkptr,
3564        libtrace_linktype_t linktype, uint8_t *antenna);
3565
3566/*@}*/
3567
3568#ifdef __cplusplus
3569} /* extern "C" */
3570#endif /* #ifdef __cplusplus */
3571#endif /* LIBTRACE_H_ */
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