source: lib/libtrace.h.in @ c0506ea

4.0.1-hotfixescachetimestampsdevelopdpdk-ndagetsilivegetfragoffhelplibtrace4ndag_formatpfringrc-4.0.1rc-4.0.2rc-4.0.3rc-4.0.4ringdecrementfixringperformanceringtimestampfixes
Last change on this file since c0506ea was c0506ea, checked in by Shane Alcock <salcock@…>, 10 years ago
  • We now use pcap_create and pcap_activate for pcap interfaces if libpcap 1.0 or later is available. This doesn't seem to make much of a difference performance-wise, as pcap_open_live was updated to use these functions anyway. This means if mmapped packet capture is available, we would have used it via pcap_open_live anyway.
  • Added a new function (trace_interrupt). Calling this function will set an internal variable which can be used to cause any blocking read_packet function to exit with an EOF. Useful for programs that are handling signals themselves and need a way to tell libtrace to stop. Prior to this, programs like tracestats would not exit on Ctrl-C if reading from a pcap interface which was not receiving any packets.
  • Updated pcap interface format to respond to trace_interrupt.
  • Optimising trace_apply_filter to minimise calls to trace_get_link_type and trace_get_packet_buffer.
  • Removed unused extern variable "form" from libtrace_int.h
  • Fixed bug with filters in the pcap interface format which would result in "invalid BPF program" error message when filter was definitely legit.
  • Updated version number to 3.0.13
  • Property mode set to 100644
File size: 96.9 KB
Line 
1/*
2 * This file is part of libtrace
3 *
4 * Copyright (c) 2007,2008,2009,2010 The University of Waikato, Hamilton,
5 * New Zealand.
6 *
7 * Authors: Daniel Lawson
8 *          Perry Lorier
9 *          Shane Alcock
10 *         
11 * All rights reserved.
12 *
13 * This code has been developed by the University of Waikato WAND
14 * research group. For further information please see http://www.wand.net.nz/
15 *
16 * libtrace is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
20 *
21 * libtrace is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24 * GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with libtrace; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
29 *
30 * $Id$
31 *
32 */
33
34#ifndef LIBTRACE_H
35#define LIBTRACE_H
36
37/** @file
38 *
39 * @brief Trace file processing library header
40 *
41 * @author Daniel Lawson
42 * @author Perry Lorier
43 * @author Shane Alcock
44 *
45 * @version $Id$
46 *
47 * This library provides a per packet interface into a trace file, or a live
48 * captures.  It supports ERF, DAG cards, PCAP, Linux and BSD native sockets,
49 * legacy ERF formats etc.
50 *
51 * @par Usage
52 * See the example/ directory in the source distribution for some simple
53 * examples
54 *
55 * @par Linking
56 * To use this library you need to link against libtrace by passing -ltrace
57 * to your linker. You may also need to link against a version of libpcap
58 * and of zlib which are compiled for largefile support (if you wish to access
59 * traces larger than 2 GB). This is left as an exercise for the reader. Debian
60 * Woody, at least, does not support large file offsets.
61 *
62 */
63
64#include <sys/types.h>
65#ifndef WIN32
66#include <sys/time.h>
67#endif
68
69#ifdef _MSC_VER
70    /* define the following from MSVC's internal types */
71    typedef             __int8  int8_t;
72    typedef             __int16 int16_t;
73    typedef             __int32 int32_t;
74    typedef             __int64 int64_t;
75    typedef unsigned    __int8  uint8_t;
76    typedef unsigned    __int16 uint16_t;
77    typedef unsigned    __int32 uint32_t;
78    typedef unsigned    __int64 uint64_t;
79    #ifdef LT_BUILDING_DLL
80        #define DLLEXPORT __declspec(dllexport)
81    #else
82        #define DLLEXPORT __declspec(dllimport)
83    #endif
84    #define DLLLOCAL
85    /* Windows pads bitfields out to to the size of their parent type
86     * however gcc warns that this doesn't meet with the iso C specification
87     * so produces warnings for this behaviour.  sigh.
88     */
89    #define LT_BITFIELD8        uint8_t
90    #define LT_BITFIELD16       uint16_t
91    #define LT_BITFIELD32       uint32_t
92    #define LT_BITFIELD64       uint64_t
93#else
94    #ifdef HAVE_STDINT_H
95        #   include <stdint.h>
96    #endif
97    #if __GNUC__ >= 4
98        #ifdef LT_BUILDING_DLL
99                #define DLLEXPORT __attribute__ ((visibility("default")))
100                #define DLLLOCAL __attribute__ ((visibility("hidden")))
101        #else
102                #define DLLEXPORT
103                #define DLLLOCAL
104        #endif
105    #else
106        #define DLLEXPORT
107        #define DLLLOCAL
108    #endif
109    /* GCC warns if the bitfield type is not "unsigned int", however windows
110     * generates incorrect code for this (see above), so we define these
111     * macros.  How Hideous.  So much for C's portability.
112     */
113    #define LT_BITFIELD8        unsigned int
114    #define LT_BITFIELD16       unsigned int
115    #define LT_BITFIELD32       unsigned int
116    #define LT_BITFIELD64       unsigned int
117#endif
118
119#ifdef WIN32
120#   include <winsock2.h>
121#   include <ws2tcpip.h>
122    typedef short sa_family_t;
123    /* Make up for a lack of stdbool.h */
124#    define bool signed char
125#    define false 0
126#    define true 1
127#    if !defined(ssize_t)
128     /* XXX: Not 64-bit safe! */
129#    define ssize_t int
130#    endif   
131#else
132#    include <netinet/in.h>
133
134#ifndef __cplusplus
135#    include <stdbool.h>
136#endif
137
138#    include <sys/types.h>
139#    include <sys/socket.h>
140#endif
141
142/** API version as 2 byte hex digits, eg 0xXXYYZZ */
143#define LIBTRACE_API_VERSION \
144            ((@LIBTRACE_MAJOR@<<16)|(@LIBTRACE_MID@<<8)|(@LIBTRACE_MINOR@))
145
146/** Replaced with the current SVN revision number when 'make dist' is invoked
147 *  to create a distributable tarball */
148#define LIBTRACE_SVN_REVISION 0
149
150/** DAG driver version installed on the current system */
151#define DAG_DRIVER_V "@DAG_VERSION_NUM@"
152   
153#ifdef __cplusplus
154extern "C" {
155#endif
156
157/* Function does not depend on anything but its
158 * parameters, used to hint gcc's optimisations
159 */
160#if __GNUC__ >= 3
161#  define DEPRECATED __attribute__((deprecated))
162#  define SIMPLE_FUNCTION __attribute__((pure))
163#  define UNUSED __attribute__((unused))
164#  define PACKED __attribute__((packed))
165#  define PRINTF(formatpos,argpos) __attribute__((format(printf,formatpos,argpos)))
166#else
167#  define DEPRECATED
168#  define SIMPLE_FUNCTION
169#  define UNUSED
170#  define PACKED
171#  define PRINTF(formatpos,argpos)
172#endif
173       
174/** Opaque structure holding information about an output trace */
175typedef struct libtrace_out_t libtrace_out_t;
176       
177/** Opaque structure holding information about a trace */
178typedef struct libtrace_t libtrace_t;
179       
180/** Opaque structure holding information about a bpf filter */
181typedef struct libtrace_filter_t libtrace_filter_t;
182
183/** If the packet has allocated its own memory the buffer_control should be
184 * set to TRACE_CTRL_PACKET, so that the memory will be freed when the packet
185 * is destroyed. If the packet has been zerocopied out of memory owned by
186 * something else, e.g. a DAG card, it should be TRACE_CTRL_EXTERNAL.
187 *
188 * @note The letters p and e are magic numbers used to detect if the packet
189 * wasn't created properly.
190 */
191typedef enum {
192        TRACE_CTRL_PACKET='p',  /**< Buffer memory is owned by the packet */
193        TRACE_CTRL_EXTERNAL='e' /**< Buffer memory is owned by an external source */
194} buf_control_t;
195
196/** The size of a packet's buffer when managed by libtrace */
197#define LIBTRACE_PACKET_BUFSIZE 65536
198
199/** Libtrace error information */
200typedef struct trace_err_t{
201        int err_num;            /**< error code */
202        char problem[255];      /**< the format, uri etc that caused the error for reporting purposes */
203} libtrace_err_t;
204
205/** Enumeration of error codes */
206enum {
207        /** No Error has occured.... yet. */
208        TRACE_ERR_NOERROR       = 0,
209        /** The URI passed to trace_create() is unsupported, or badly formed */
210        TRACE_ERR_BAD_FORMAT    = -1,
211        /** The trace failed to initialise */
212        TRACE_ERR_INIT_FAILED   = -2,
213        /** Unknown config option */
214        TRACE_ERR_UNKNOWN_OPTION= -3,
215        /** This output uri cannot write packets of this type */
216        TRACE_ERR_NO_CONVERSION = -4,
217        /** This packet is corrupt, or unusable for the action required */
218        TRACE_ERR_BAD_PACKET    = -5,
219        /** Option known, but unsupported by this format */
220        TRACE_ERR_OPTION_UNAVAIL= -6,
221        /** This feature is unsupported */
222        TRACE_ERR_UNSUPPORTED   = -7,
223        /** Illegal use of the API */
224        TRACE_ERR_BAD_STATE     = -8
225};
226
227/** Enumeration of DLTs supported by libtrace
228 */
229typedef enum {
230        /** pcap documents this as having the Address Family value in host byte order as the
231          * framing.  Ugly? Yes.
232          */
233        TRACE_DLT_NULL = 0,
234        TRACE_DLT_EN10MB = 1,
235        TRACE_DLT_PPP = 9,
236        TRACE_DLT_ATM_RFC1483 = 11,
237       
238        /** Ok, so OpenBSD has a different value for DLT_RAW as the rest of the planet, so detect
239          * this.  When reading to/from files we should be using TRACE_DLT_LINKTYPE_RAW instead.
240          * When talking about DLT's inside libtrace tho, we should be using /these/ DLT's.
241          */
242#ifdef __OpenBSD__
243        TRACE_DLT_RAW = 14,     
244#else
245        TRACE_DLT_RAW = 12,
246#endif
247        TRACE_DLT_PPP_SERIAL = 50,
248        TRACE_DLT_LINKTYPE_RAW = 101, /**< See TRACE_DLT_RAW for explainations of pain. */
249        TRACE_DLT_C_HDLC = 104,
250        TRACE_DLT_IEEE802_11 = 105,
251        TRACE_DLT_LINUX_SLL = 113,
252        TRACE_DLT_PFLOG = 117,
253        TRACE_DLT_IEEE802_11_RADIO = 127 /**< Radiotap */
254} libtrace_dlt_t ;
255
256/** Enumeration of link layer types supported by libtrace */
257typedef enum {
258    /* TRACE_TYPE_LEGACY = 0            Obsolete */
259       TRACE_TYPE_HDLC_POS = 1,         /**< HDLC over POS */
260       TRACE_TYPE_ETH = 2,              /**< 802.3 style Ethernet */
261       TRACE_TYPE_ATM = 3,              /**< ATM frame */
262       TRACE_TYPE_80211 = 4,            /**< 802.11 frames */
263       TRACE_TYPE_NONE = 5,             /**< Raw IP frames */
264       TRACE_TYPE_LINUX_SLL = 6,        /**< Linux "null" framing */
265       TRACE_TYPE_PFLOG = 7,            /**< FreeBSD's PFlog */
266    /* TRACE_TYPE_LEGACY_DEFAULT        Obsolete */
267       TRACE_TYPE_POS = 9,              /**< Packet-over-SONET */
268    /* TRACE_TYPE_LEGACY_ATM            Obsolete */
269    /* TRACE_TYPE_LEGACY_ETH            Obsolete */
270       TRACE_TYPE_80211_PRISM = 12,     /**< 802.11 Prism frames */
271       TRACE_TYPE_AAL5 = 13,            /**< ATM Adaptation Layer 5 frames */
272       TRACE_TYPE_DUCK = 14,         /**< Pseudo link layer for DUCK packets */
273       TRACE_TYPE_80211_RADIO = 15,  /**< Radiotap + 802.11 */
274       TRACE_TYPE_LLCSNAP = 16,      /**< Raw LLC/SNAP */
275       TRACE_TYPE_PPP = 17,          /**< PPP frames */
276       TRACE_TYPE_METADATA = 18,        /**< WDCAP-style meta-data */
277       TRACE_TYPE_NONDATA = 19          /**< Not a data packet */
278} libtrace_linktype_t;
279
280/** RT protocol base format identifiers.
281 * This is used to describe the capture format of the packet is being sent
282 * using the RT protocol.
283 */
284enum base_format_t {
285        TRACE_FORMAT_ERF          =1,   /**< ERF (DAG capture format) */
286        TRACE_FORMAT_PCAP         =2,   /**< Live PCAP capture */
287        TRACE_FORMAT_PCAPFILE     =3,   /**< PCAP trace file */
288        TRACE_FORMAT_WAG          =4,   /**< WAG live capture (Obsolete) */
289        TRACE_FORMAT_RT           =5,   /**< RT network protocol */
290        TRACE_FORMAT_LEGACY_ATM   =6,   /**< Legacy ERF for ATM capture */
291        TRACE_FORMAT_LEGACY_POS   =7,   /**< Legacy ERF for POS capture */
292        TRACE_FORMAT_LEGACY_ETH   =8,   /**< Legacy ERF for ETH capture */
293        TRACE_FORMAT_LINUX_NATIVE =9,   /**< Linux native interface capture */
294        TRACE_FORMAT_DUCK         =10,  /**< DAG Clock information */
295        TRACE_FORMAT_BPF          =11,  /**< BSD native interface capture */
296        TRACE_FORMAT_TSH          =12,  /**< TSH trace format */
297        TRACE_FORMAT_ATMHDR       =13,  /**< Legacy ATM header capture */
298        TRACE_FORMAT_LEGACY_NZIX  =14   /**< Legacy format used for NZIX traces */
299};
300
301/** RT protocol packet types */
302typedef enum {
303        TRACE_RT_HELLO          =1, /**< Connection accepted */
304        TRACE_RT_START          =2, /**< Request for data transmission to begin
305                                    */
306        TRACE_RT_ACK            =3, /**< Data acknowledgement */
307        TRACE_RT_STATUS         =4, /**< Fifo status packet */
308        TRACE_RT_DUCK           =5, /**< Dag duck info packet */
309        TRACE_RT_END_DATA       =6, /**< Server is exiting message */
310        TRACE_RT_CLOSE          =7, /**< Client is exiting message */
311        TRACE_RT_DENY_CONN      =8, /**< Connection has been denied */
312        TRACE_RT_PAUSE          =9, /**< Request server to suspend sending data
313                                     */
314        TRACE_RT_PAUSE_ACK      =10,/**< Server is paused message */
315        TRACE_RT_OPTION         =11,/**< Option request */
316        TRACE_RT_KEYCHANGE      =12,/**< Anonymisation key has changed */
317        TRACE_RT_DUCK_2_4       =13,/**< Dag 2.4 Duck */
318        TRACE_RT_DUCK_2_5       =14,/**< Dag 2.5 Duck */
319        TRACE_RT_LOSTCONN       =15,/**< Lost connection to server */
320        TRACE_RT_SERVERSTART    =16,/**< Reliable server has been restarted */
321        TRACE_RT_CLIENTDROP     =17,/**< Reliable client was lost */
322        TRACE_RT_METADATA       =18,/**< Packet contains server meta-data */
323
324        /** Not actually used - all DATA types begin from this value */
325        TRACE_RT_DATA_SIMPLE    = 1000,
326       
327        /** RT is encapsulating an ERF capture record */
328        TRACE_RT_DATA_ERF       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_ERF,
329        /** RT is encapsulating a WAG capture record */
330        TRACE_RT_DATA_WAG       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_WAG,
331        /** RT is encapsulating a Legacy ATM capture record */
332        TRACE_RT_DATA_LEGACY_ATM=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_ATM,
333        /** RT is encapsulating a Legacy POS capture record */
334        TRACE_RT_DATA_LEGACY_POS=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_POS,
335        /** RT is encapsulating a Legacy ETH capture record */
336        TRACE_RT_DATA_LEGACY_ETH=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_ETH,
337        /** RT is encapsulating a Linux native capture record */
338        TRACE_RT_DATA_LINUX_NATIVE=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LINUX_NATIVE,
339        /** RT is encapsulating a BSD native capture record */
340        TRACE_RT_DATA_BPF       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_BPF,
341        /** RT is encapsulating a TSH capture record */
342        TRACE_RT_DATA_TSH       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_TSH,
343        /** RT is encapsulating an ATM header capture record */
344        TRACE_RT_DATA_ATMHDR = TRACE_RT_DATA_SIMPLE + TRACE_FORMAT_ATMHDR,
345        /** RT is encapsulating a Legacy NZIX capture record */
346        TRACE_RT_DATA_LEGACY_NZIX=TRACE_RT_DATA_SIMPLE + TRACE_FORMAT_LEGACY_NZIX,
347
348        /** As PCAP does not store the linktype with the packet, we need to
349         * create a separate RT type for each supported DLT, starting from
350         * this value */
351        TRACE_RT_DATA_DLT               = 2000,
352        /** RT is encapsulating a PCAP capture record with a NULL linktype */
353        TRACE_RT_DLT_NULL               =TRACE_RT_DATA_DLT+TRACE_DLT_NULL,
354        /** RT is encapsulating a PCAP capture record with an Ethernet
355         * linktype */
356        TRACE_RT_DLT_EN10MB             =TRACE_RT_DATA_DLT+TRACE_DLT_EN10MB,
357        /** RT is encapsulating a PCAP capture record with an 802.11
358         * linktype */
359        TRACE_RT_DLT_IEEE802_11         =TRACE_RT_DATA_DLT+TRACE_DLT_IEEE802_11,
360        /** RT is encapsulating a PCAP capture record with a Linux SLL
361         * linktype */
362        TRACE_RT_DLT_LINUX_SLL          =TRACE_RT_DATA_DLT+TRACE_DLT_LINUX_SLL,
363        /** RT is encapsulating a PCAP capture record with a PFlog linktype */
364        TRACE_RT_DLT_PFLOG              =TRACE_RT_DATA_DLT+TRACE_DLT_PFLOG,
365        /** RT is encapsulating a PCAP capture record with an AAL5 linktype */
366        TRACE_RT_DLT_ATM_RFC1483        =TRACE_RT_DATA_DLT+TRACE_DLT_ATM_RFC1483,
367        /** Unused value marking the end of the valid range for PCAP RT
368         * encapsulation */
369        TRACE_RT_DATA_DLT_END           = 2999,
370        /** Unused value marking the end of the valid range for all RT packet
371         * types */
372        TRACE_RT_LAST                   = (2<<31)
373} libtrace_rt_types_t;
374
375/** IP Protocol values */
376typedef enum {
377        TRACE_IPPROTO_IP        = 0,    /**< IP pseudo protocol number */
378        TRACE_IPPROTO_ICMP      = 1,    /**< Internet Control Message protocol */
379        TRACE_IPPROTO_IGMP      = 2,    /**< Internet Group Management Protocol */
380        TRACE_IPPROTO_IPIP      = 4,    /**< IP encapsulated in IP */
381        TRACE_IPPROTO_TCP       = 6,    /**< Transmission Control Protocol */
382        TRACE_IPPROTO_UDP       = 17,   /**< User Datagram Protocol */
383        TRACE_IPPROTO_IPV6      = 41,   /**< IPv6 over IPv4 */
384        TRACE_IPPROTO_ROUTING   = 43,   /**< IPv6 Routing header */
385        TRACE_IPPROTO_FRAGMENT  = 44,   /**< IPv6 Fragmentation header */
386        TRACE_IPPROTO_RSVP      = 46,   /**< Resource Reservation Protocol */
387        TRACE_IPPROTO_GRE       = 47,   /**< General Routing Encapsulation */
388        TRACE_IPPROTO_ESP       = 50,   /**< Encapsulated Security Payload [RFC2406] */
389        TRACE_IPPROTO_AH        = 51,   /**< Authentication Header [RFC2402] */
390        TRACE_IPPROTO_ICMPV6    = 58,   /**< ICMPv6 */
391        TRACE_IPPROTO_NONE      = 59,   /**< IPv6 no next header */
392        TRACE_IPPROTO_DSTOPTS   = 60,   /**< IPv6 destination options */
393        TRACE_IPPROTO_PIM       = 103,  /**< Protocol Independant Multicast */
394        TRACE_IPPROTO_SCTP      = 132   /**< Stream Control Transmission Protocol */
395} libtrace_ipproto_t;
396
397/** Ethertypes supported by Libtrace */
398typedef enum {
399        /* Numbers <=1500 are of course, LLC/SNAP */
400        TRACE_ETHERTYPE_IP      = 0x0800,       /**< IPv4 */
401        TRACE_ETHERTYPE_ARP     = 0x0806,       /**< Address resolution protocol */
402        TRACE_ETHERTYPE_RARP    = 0x8035,       /**< Reverse ARP */
403        TRACE_ETHERTYPE_8021Q   = 0x8100,       /**< 802.1q VLAN Extended Header */
404        TRACE_ETHERTYPE_IPV6    = 0x86DD,       /**< IPv6 */
405        TRACE_ETHERTYPE_MPLS    = 0x8847,       /**< MPLS Unicast traffic */
406        TRACE_ETHERTYPE_MPLS_MC = 0x8848,       /**< MPLS Multicast traffic */
407        TRACE_ETHERTYPE_PPP_DISC= 0x8863,       /**< PPPoE Service Discovery */
408        TRACE_ETHERTYPE_PPP_SES = 0x8864        /**< PPPoE Session Messages */
409} libtrace_ethertype_t;
410
411/** The libtrace packet structure. Applications shouldn't be
412 * meddling around in here
413 */
414typedef struct libtrace_packet_t {
415        struct libtrace_t *trace;       /**< Pointer to the trace */
416        void *header;                   /**< Pointer to the framing header */
417        void *payload;                  /**< Pointer to the link layer */
418        void *buffer;                   /**< Allocated buffer */
419        libtrace_rt_types_t  type;      /**< RT protocol type for the packet */
420        buf_control_t buf_control;      /**< Describes memory ownership */
421        int capture_length;             /**< Cached capture length */
422        int payload_length;             /**< Cached payload length */
423        void *l2_header;                /**< Cached link header */
424        libtrace_linktype_t link_type;  /**< Cached link type */
425        uint32_t l2_remaining;          /**< Cached link remaining */
426        void *l3_header;                /**< Cached l3 header */
427        uint16_t l3_ethertype;          /**< Cached l3 ethertype */
428        uint32_t l3_remaining;          /**< Cached l3 remaining */
429        void *l4_header;                /**< Cached transport header */
430        uint8_t transport_proto;        /**< Cached transport protocol */
431        uint32_t l4_remaining;          /**< Cached transport remaining */
432} libtrace_packet_t;
433
434
435/** Trace directions.
436 * Note that these are the directions used by convention. More directions
437 * are possible, not just these 3, and that they may not conform to this
438 * convention.
439 */
440typedef enum {
441        TRACE_DIR_OUTGOING = 0,         /**< Packets originating "inside" */
442        TRACE_DIR_INCOMING = 1,         /**< Packets originating "outside" */
443        TRACE_DIR_OTHER    = 2          /**< Packets with an unknown direction, or one that's unknown */
444} libtrace_direction_t;
445
446/** Enumeration of Radiotap fields */
447typedef enum {
448    TRACE_RADIOTAP_TSFT = 0, /**< Timer synchronisation function, in microseconds (uint64) */
449    TRACE_RADIOTAP_FLAGS = 1, /**< Wireless flags (uint8) */
450    TRACE_RADIOTAP_RATE = 2, /**< Bitrate in units of 500kbps (uint8) */
451    TRACE_RADIOTAP_CHANNEL = 3, /**< Frequency in MHz (uint16) and channel flags (uint16) */
452    TRACE_RADIOTAP_FHSS = 4, /**< FHSS hop set (uint8) and hopping pattern (uint8) */
453    TRACE_RADIOTAP_DBM_ANTSIGNAL = 5, /**< Signal power in dBm (int8) */
454    TRACE_RADIOTAP_DBM_ANTNOISE = 6, /**< Noise power in dBm (int8) */
455    TRACE_RADIOTAP_LOCK_QUALITY = 7, /**< Barker Code lock quality (uint16) */
456    TRACE_RADIOTAP_TX_ATTENUATION = 8, /**< TX attenuation as unitless distance from max power (uint16) */
457    TRACE_RADIOTAP_DB_TX_ATTENUATION = 9, /**< TX attenutation as dB from max power (uint16) */
458    TRACE_RADIOTAP_DBM_TX_POWER = 10, /**< TX Power in dBm (int8) */
459    TRACE_RADIOTAP_ANTENNA = 11, /**< Antenna frame was rx'd or tx'd on (uint8) */
460    TRACE_RADIOTAP_DB_ANTSIGNAL = 12, /**< Signal power in dB from a fixed reference (uint8) */
461    TRACE_RADIOTAP_DB_ANTNOISE = 13, /**< Noise power in dB from a fixed reference (uint8) */
462    TRACE_RADIOTAP_RX_FLAGS = 14, /** Properties of received frame (uint16) */
463    TRACE_RADIOTAP_TX_FLAGS = 15, /** Properties of transmitted frame (uint16) */
464    TRACE_RADIOTAP_RTS_RETRIES = 16, /** Number of rts retries frame used (uint8) */
465    TRACE_RADIOTAP_DATA_RETRIES = 17, /** Number of unicast retries a transmitted frame used (uint8) */
466    TRACE_RADIOTAP_EXT = 31
467} libtrace_radiotap_field_t;
468
469
470/** @name Protocol structures
471 * These convenience structures provide portable versions of the headers
472 * for a variety of protocols.
473 * @{
474 */
475
476#ifdef WIN32
477#pragma pack(push)
478#pragma pack(1)
479#endif
480
481/** Generic IP header structure */
482typedef struct libtrace_ip
483{
484#if BYTE_ORDER == LITTLE_ENDIAN
485    LT_BITFIELD8 ip_hl:4;               /**< Header Length */
486    LT_BITFIELD8 ip_v:4;                /**< Version */
487#elif BYTE_ORDER == BIG_ENDIAN
488    LT_BITFIELD8 ip_v:4;                /**< Version */
489    LT_BITFIELD8 ip_hl:4;               /**< Header Length */
490#else
491#   error "Adjust your <bits/endian.h> defines"
492#endif
493    uint8_t  ip_tos;                    /**< Type of Service */
494    uint16_t ip_len;                    /**< Total Length */
495    int16_t  ip_id;                     /**< Identification */
496    uint16_t ip_off;                    /**< IP Fragment offset (and flags) */
497    uint8_t  ip_ttl;                    /**< Time to Live */
498    uint8_t  ip_p;                      /**< Protocol */
499    uint16_t ip_sum;                    /**< Checksum */
500    struct in_addr ip_src;              /**< Source Address */
501    struct in_addr ip_dst;              /**< Destination Address */
502} PACKED libtrace_ip_t;
503
504/** IPv6 header extension structure */
505typedef struct libtrace_ip6_ext
506{
507        uint8_t nxt;    /**< Next header */
508        uint8_t len;    /**< Length of the current header */
509} PACKED libtrace_ip6_ext_t;
510
511typedef struct libtrace_ip6_frag
512{
513        uint8_t nxt;    /**< Next header */
514        uint8_t res;    /**< Reserved */
515        uint16_t frag_off;      /**< Fragment Offset (includes M flag) */
516        uint32_t ident; /** Fragment identification */
517} PACKED libtrace_ip6_frag_t;
518
519/** Generic IPv6 header structure
520 *
521 * @note The flow label field also includes the Version and Traffic Class
522 * fields, because we haven't figured out a nice way to deal with fields
523 * crossing byte boundaries on both Big and Little Endian machines */
524typedef struct libtrace_ip6
525{
526    uint32_t flow;                      /**< Flow label */
527    uint16_t plen;                      /**< Payload length */
528    uint8_t nxt;                        /**< Next header */
529    uint8_t hlim;                       /**< Hop limit */
530    struct in6_addr ip_src;             /**< Source address */
531    struct in6_addr ip_dst;             /**< Destination address */
532} PACKED libtrace_ip6_t;
533
534/** Generic TCP header structure */
535typedef struct libtrace_tcp
536  {
537    uint16_t source;            /**< Source Port */
538    uint16_t dest;              /**< Destination port */
539    uint32_t seq;               /**< Sequence number */
540    uint32_t ack_seq;           /**< Acknowledgement Number */
541#  if BYTE_ORDER == LITTLE_ENDIAN
542    LT_BITFIELD8 ecn_ns:1;      /**< ECN Nonce Sum */
543    LT_BITFIELD8 res1:3;        /**< Reserved bits */
544    LT_BITFIELD8 doff:4;        /**< Data Offset */
545    LT_BITFIELD8 fin:1;         /**< FIN */
546    LT_BITFIELD8 syn:1;         /**< SYN flag */
547    LT_BITFIELD8 rst:1;         /**< RST flag */
548    LT_BITFIELD8 psh:1;         /**< PuSH flag */
549    LT_BITFIELD8 ack:1;         /**< ACK flag */
550    LT_BITFIELD8 urg:1;         /**< URG flag */
551    LT_BITFIELD8 ece:1;         /**< ECN Echo */
552    LT_BITFIELD8 cwr:1;         /**< ECN CWR */
553#  elif BYTE_ORDER == BIG_ENDIAN
554    LT_BITFIELD8 doff:4;        /**< Data offset */
555    LT_BITFIELD8 res1:3;        /**< Reserved bits */
556    LT_BITFIELD8 ecn_ns:1;      /**< ECN Nonce Sum */
557    LT_BITFIELD8 cwr:1;         /**< ECN CWR */
558    LT_BITFIELD8 ece:1;         /**< ECN Echo */
559    LT_BITFIELD8 urg:1;         /**< URG flag */
560    LT_BITFIELD8 ack:1;         /**< ACK flag */
561    LT_BITFIELD8 psh:1;         /**< PuSH flag */
562    LT_BITFIELD8 rst:1;         /**< RST flag */
563    LT_BITFIELD8 syn:1;         /**< SYN flag */
564    LT_BITFIELD8 fin:1;         /**< FIN flag */
565#  else
566#   error "Adjust your <bits/endian.h> defines"
567#  endif
568    uint16_t window;            /**< Window Size */
569    uint16_t check;             /**< Checksum */
570    uint16_t urg_ptr;           /**< Urgent Pointer */
571} PACKED libtrace_tcp_t;
572
573/** Generic UDP header structure */
574typedef struct libtrace_udp {
575  uint16_t      source;         /**< Source port */
576  uint16_t      dest;           /**< Destination port */
577  uint16_t      len;            /**< Length */
578  uint16_t      check;          /**< Checksum */
579} PACKED libtrace_udp_t;
580
581/** Generic ICMP header structure */
582typedef struct libtrace_icmp
583{
584  uint8_t type;         /**< Message Type */
585  uint8_t code;         /**< Type Sub-code */
586  uint16_t checksum;            /**< Checksum */
587  union
588  {
589    struct
590    {
591      uint16_t  id;             /**< ID of the Echo request */
592      uint16_t  sequence;       /**< Sequence number of the Echo request */
593    } echo;                     /**< Echo Datagram */
594    uint32_t    gateway;        /**< Gateway Address */
595    struct
596    {
597      uint16_t  unused;         /**< Unused */
598      uint16_t  mtu;            /**< Next-hop MTU */
599    } frag;                     /**< Path MTU Discovery */
600  } un;                         /**< Union for Payloads of Various ICMP Codes */
601} PACKED libtrace_icmp_t;
602
603/** Generic LLC/SNAP header structure */
604typedef struct libtrace_llcsnap
605{
606/* LLC */
607  uint8_t dsap;                 /**< Destination Service Access Point */
608  uint8_t ssap;                 /**< Source Service Access Point */
609  uint8_t control;              /**< Control field */
610/* SNAP */
611  LT_BITFIELD32 oui:24;         /**< Organisationally Unique Identifier (scope)*/
612  uint16_t type;                /**< Protocol within OUI */
613} PACKED libtrace_llcsnap_t;
614
615/** 802.3 frame */
616typedef struct libtrace_ether
617{
618  uint8_t ether_dhost[6];       /**< Destination Ether Addr */
619  uint8_t ether_shost[6];       /**< Source Ether Addr */
620  uint16_t ether_type;          /**< Packet Type ID Field (next-header) */
621} PACKED libtrace_ether_t;
622
623/** 802.1Q frame */
624typedef struct libtrace_8021q
625{
626  LT_BITFIELD16 vlan_pri:3;      /**< VLAN User Priority */
627  LT_BITFIELD16 vlan_cfi:1;      /**< VLAN Format Indicator,
628                                   * 0 for ethernet, 1 for token ring */
629  LT_BITFIELD16 vlan_id:12;      /**< VLAN Id */
630  uint16_t vlan_ether_type;      /**< VLAN Sub-packet Type ID Field
631                                   * (next-header)*/
632} PACKED libtrace_8021q_t;
633
634/** ATM User Network Interface (UNI) Cell. */
635typedef struct libtrace_atm_cell
636{
637  LT_BITFIELD32 gfc:4;          /**< Generic Flow Control */
638  LT_BITFIELD32 vpi:8;          /**< Virtual Path Identifier */
639  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
640  LT_BITFIELD32 pt:3;           /**< Payload Type */
641  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
642  LT_BITFIELD32 hec:8;          /**< Header Error Control */
643} PACKED libtrace_atm_cell_t;
644
645/** ATM Network Node/Network Interface (NNI) Cell. */
646typedef struct libtrace_atm_nni_cell
647{
648  LT_BITFIELD32 vpi:12;         /**< Virtual Path Identifier */
649  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
650  LT_BITFIELD32 pt:3;           /**< Payload Type */
651  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
652  LT_BITFIELD32 hec:8;          /**< Header Error Control */
653} PACKED libtrace_atm_nni_cell_t;
654
655/** Captured UNI cell.
656 *
657 * Endace don't capture the HEC, presumably to keep alignment.  This
658 * version of the \ref libtrace_atm_cell is used when dealing with DAG
659 * captures of uni cells.
660 *
661 */
662typedef struct libtrace_atm_capture_cell
663{
664  LT_BITFIELD32 gfc:4;          /**< Generic Flow Control */
665  LT_BITFIELD32 vpi:8;          /**< Virtual Path Identifier */
666  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
667  LT_BITFIELD32 pt:3;           /**< Payload Type */
668  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
669} PACKED libtrace_atm_capture_cell_t;
670
671/** Captured NNI cell.
672 *
673 * Endace don't capture the HEC, presumably to keep alignment.  This
674 * version of the \ref libtrace_atm_nni_cell is used when dealing with DAG
675 * captures of nni cells.
676 *
677 */
678typedef struct libtrace_atm_nni_capture_cell
679{
680  LT_BITFIELD32 vpi:12;         /**< Virtual Path Identifier */
681  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
682  LT_BITFIELD32 pt:3;           /**< Payload Type */
683  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
684  LT_BITFIELD32 hec:8;          /**< Header Error Control */
685} PACKED libtrace_atm_nni_capture_cell_t;
686
687/** PPP header */
688typedef struct libtrace_ppp
689{
690 /* I can't figure out where the hell these two variables come from. They're
691  * definitely not in RFC 1661 which defines PPP. Probably some weird thing
692  * relating to the lack of distinction between PPP, HDLC and CHDLC */
693       
694/* uint8_t address; */          /**< PPP Address (0xFF - All stations) */
695/* uint8_t header;  */          /**< PPP Control (0x03 - Unnumbered info) */
696 uint16_t protocol;             /**< PPP Protocol (htons(0x0021) - IPv4 */
697} PACKED libtrace_ppp_t;
698
699/** PPPoE header */
700typedef struct libtrace_pppoe
701{
702 LT_BITFIELD8 version:4;        /**< Protocol version number */
703 LT_BITFIELD8 type:4;           /**< PPPoE Type */
704 uint8_t code;                  /**< PPPoE Code */
705 uint16_t session_id;           /**< Session Identifier */
706 uint16_t length;               /**< Total Length of the PPP packet */
707} PACKED libtrace_pppoe_t;
708
709/** 802.11 header */
710typedef struct libtrace_80211_t {
711#if BYTE_ORDER == LITTLE_ENDIAN
712        LT_BITFIELD32      protocol:2;  /**< Protocol Version */
713        LT_BITFIELD32      type:2;      /**< Frame Type */
714        LT_BITFIELD32      subtype:4;   /**< Frame Subtype */
715#else
716        LT_BITFIELD32      subtype:4;   /**< Frame Subtype */
717        LT_BITFIELD32      type:2;      /**< Frame Type */
718        LT_BITFIELD32      protocol:2;  /**< Protocol Version */
719#endif
720
721#if BYTE_ORDER == LITTLE_ENDIAN
722        LT_BITFIELD32      to_ds:1;     /**< Packet to Distribution Service */
723        LT_BITFIELD32      from_ds:1;   /**< Packet from Distribution Service */
724        LT_BITFIELD32      more_frag:1; /**< Packet has more fragments */
725        LT_BITFIELD32      retry:1;     /**< Packet is a retry */
726        LT_BITFIELD32      power:1;     /**< Power Management mode */
727        LT_BITFIELD32      more_data:1; /**< More data is buffered at station */
728        LT_BITFIELD32      wep:1;       /**< WEP encryption indicator */
729        LT_BITFIELD32      order:1;     /**< Strictly-Ordered class indicator */
730#else
731        LT_BITFIELD32      order:1;     /**< Strictly-Ordered class indicator */
732        LT_BITFIELD32      wep:1;       /**< WEP encryption indicator */
733        LT_BITFIELD32      more_data:1; /**< More data is buffered at station */
734        LT_BITFIELD32      power:1;     /**< Power Management mode */
735        LT_BITFIELD32      retry:1;     /**< Packet is a retry */
736        LT_BITFIELD32      more_frag:1; /**< Packet has more fragments */
737        LT_BITFIELD32      from_ds:1;   /**< Packet from Distribution Service */
738        LT_BITFIELD32      to_ds:1;     /**< Packet to Distribution Service */
739#endif
740        uint16_t     duration;  /**< Duration value for NAV calculation */
741        uint8_t      mac1[6];   /**< MAC Address 1 */
742        uint8_t      mac2[6];   /**< MAC Address 2 */
743        uint8_t      mac3[6];   /**< MAC Address 3 */
744        uint16_t     SeqCtl;    /**< Sequence Control */       
745        uint8_t      mac4[6];   /**< MAC Address 4 */
746} PACKED libtrace_80211_t;
747
748/** The Radiotap header pre-amble
749 *
750 * All Radiotap headers start with this pre-amble, followed by the fields
751 * specified in the it_present bitmask. If bit 31 of it_present is set, then
752 * another bitmask follows.
753 * @note All of the radiotap data fields are in little-endian byte-order.
754 */
755typedef struct libtrace_radiotap_t {
756    uint8_t     it_version; /**< Radiotap version */
757    uint8_t     it_pad; /**< Padding for natural alignment */
758    uint16_t    it_len; /**< Length in bytes of the entire Radiotap header */
759    uint32_t    it_present; /**< Which Radiotap fields are present */
760} PACKED libtrace_radiotap_t;
761
762
763#ifdef WIN32
764#pragma pack(pop)
765#endif
766
767
768/*@}*/
769
770/** Prints help information for libtrace
771 *
772 * Function prints out some basic help information regarding libtrace,
773 * and then prints out the help() function registered with each input module
774 */
775DLLEXPORT void trace_help(void);
776
777/** Causes a libtrace reader to stop blocking whilst waiting on new packets
778 * and immediately return EOF.
779 *
780 * This function is useful if you are handling signals within your libtrace
781 * program. If a live source is not receiving any packets (or they are being
782 * filtered), a call to trace_read_packet will result in an infinite loop as
783 * it will block until a packet is received. Normally, a SIGINT would cause the
784 * program to end and thus break the loop, but if you are handling the signal
785 * yourself then that signal will never reach libtrace.
786 *
787 * Instead this function sets a global variable within libtrace that will
788 * cause a blocking live capture to break on the next internal timeout,
789 * allowing control to be returned to the user and their own signal handling
790 * to kick in.
791 */
792DLLEXPORT void trace_interrupt(void);
793
794/** @name Trace management
795 * These members deal with creating, configuring, starting, pausing and
796 * cleaning up a trace object
797 *@{
798 */
799
800/** Takes a uri and splits it into a format and uridata component.
801 * @param uri           The uri to be parsed
802 * @param [out] format  A pointer that will be updated to point to an allocated
803 *                      string holding the format component of the URI
804 * @return NULL if an error occured, otherwise return a pointer to the uridata
805 * component
806 *
807 * @note The format component is strdup'd by this function, so be sure to free
808 * it when you are done with the split URI. Similarly, do not pass a pointer
809 * to an allocated string into this function as the 'format' parameter, as
810 * that memory will be leaked and replaced with the strdup'd format.
811 */
812DLLEXPORT const char *trace_parse_uri(const char *uri, char **format);
813
814/** Create an input trace from a URI
815 *
816 * @param uri A valid libtrace URI to be opened
817 * @return An opaque pointer to a libtrace_t
818 *
819 * Some valid URI's are:
820 *  - erf:/path/to/erf/file
821 *  - erf:-  (stdin)
822 *  - dag:/dev/dagcard                 
823 *  - pcapint:pcapinterface                (eg: pcap:eth0)
824 *  - pcap:/path/to/pcap/file
825 *  - pcap:-
826 *  - rt:hostname
827 *  - rt:hostname:port
828 *
829 *  If an error occured when attempting to open the trace file, a
830 *  trace is still returned so trace_is_err() should be called to find out
831 *  if an error occured. The trace is created in the configuration state, you
832 *  must call trace_start before attempting to read packets from the trace.
833 */
834DLLEXPORT libtrace_t *trace_create(const char *uri);
835
836/** Creates a "dummy" trace file that has only the format type set.
837 *
838 * @param uri A valid (but fake) URI indicating the format of the dummy trace that is to be created.
839 * @return An opaque pointer to a (sparsely initialised) libtrace_t
840 *
841 * Only the format portion of the uri parameter matters - the 'file' being
842 * opened does not have to exist.
843 *
844 * @note IMPORTANT: Do not attempt to call trace_read_packet or other such
845 * functions with the dummy trace. Its intended purpose is to provide access
846 * to the format functions where the original trace may no longer exist or is
847 * not the correct format, e.g. reading ERF packets from an RT input.
848 */
849DLLEXPORT libtrace_t *trace_create_dead(const char *uri);
850
851/** Creates a trace output file from a URI.
852 *
853 * @param uri The uri string describing the output format and destination
854 * @return An opaque pointer to a libtrace_output_t
855 *
856 * Valid URIs include:
857 *  - erf:/path/to/erf/file
858 *  - pcap:/path/to/pcap/file
859 *
860 *  If an error occured when attempting to open the output trace, a trace is
861 *  still returned but trace_errno will be set. Use trace_is_err_out() and
862 *  trace_perror_output() to get more information.
863 */
864DLLEXPORT libtrace_out_t *trace_create_output(const char *uri);
865
866/** Start an input trace
867 * @param libtrace      The trace to start
868 * @return 0 on success, -1 on failure
869 *
870 * This does the actual work of starting the input trace and applying
871 * all the config options.  This may fail, returning -1. The libtrace error
872 * handling functions can be used to get more information about what
873 * specifically went wrong.
874 */
875DLLEXPORT int trace_start(libtrace_t *libtrace);
876
877/** Pauses an input trace
878 * @param libtrace      The trace to pause
879 * @return 0 on success, -1 on failure
880 *
881 * This stops an input trace that is in progress and returns you to the
882 * configuration state.  Any packets that arrive on a live capture after
883 * trace_pause() has been called will be discarded.  To resume the trace, call
884 * trace_start().
885 */
886DLLEXPORT int trace_pause(libtrace_t *libtrace);
887
888/** Start an output trace
889 * @param libtrace      The trace to start
890 * @return 0 on success, -1 on failure
891 *
892 * This does the actual work with starting a trace capable of writing packets. 
893 * This generally creates the output file.
894 */
895DLLEXPORT int trace_start_output(libtrace_out_t *libtrace);
896
897/** Valid configuration options for input traces */
898typedef enum {
899        /** Maximum number of bytes to be captured for any given packet */
900        TRACE_OPTION_SNAPLEN,   
901
902        /** If enabled, places a live capture interface into promiscuous mode */
903        TRACE_OPTION_PROMISC,   
904
905        /** Apply this filter to all packets read from this trace */
906        TRACE_OPTION_FILTER,   
907
908        /** Defines the frequency of meta-data reporting, e.g. DUCK packets */
909        TRACE_OPTION_META_FREQ,
910
911        /** If enabled, the libtrace event API will ignore time gaps between
912         * packets when reading from a trace file */
913        TRACE_OPTION_EVENT_REALTIME
914} trace_option_t;
915
916/** Sets an input config option
917 * @param libtrace      The trace object to apply the option to
918 * @param option        The option to set
919 * @param value         The value to set the option to
920 * @return -1 if option configuration failed, 0 otherwise
921 * This should be called after trace_create, and before trace_start
922 */
923DLLEXPORT int trace_config(libtrace_t *libtrace,
924                trace_option_t option,
925                void *value);
926
927/** Valid compression types
928 * Note, this must be kept in sync with WANDIO_COMPRESS_* numbers in wandio.h
929 */
930typedef enum {
931        TRACE_OPTION_COMPRESSTYPE_NONE = 0, /**< No compression */
932        TRACE_OPTION_COMPRESSTYPE_ZLIB = 1, /**< GZip Compression */
933        TRACE_OPTION_COMPRESSTYPE_BZ2  = 2, /**< BZip2 Compression */
934        TRACE_OPTION_COMPRESSTYPE_LZO  = 3  /**< LZO Compression */
935} trace_option_compresstype_t;
936
937/** Valid configuration options for output traces */
938typedef enum {
939        /** File flags to use when opening an output file, e.g. O_APPEND */
940        TRACE_OPTION_OUTPUT_FILEFLAGS,
941        /** Compression level: 0 = no compression, 1 = faster compression,
942         * 9 = better compression */
943        TRACE_OPTION_OUTPUT_COMPRESS,
944        /** Compression type, see trace_option_compresstype_t */
945        TRACE_OPTION_OUTPUT_COMPRESSTYPE
946} trace_option_output_t;
947
948/** Sets an output config option
949 *
950 * @param libtrace      The output trace object to apply the option to
951 * @param option        The option to set
952 * @param value         The value to set the option to
953 * @return -1 if option configuration failed, 0 otherwise
954 * This should be called after trace_create_output, and before
955 * trace_start_output
956 */
957DLLEXPORT int trace_config_output(libtrace_out_t *libtrace,
958                trace_option_output_t option,
959                void *value
960                );
961
962/** Close an input trace, freeing up any resources it may have been using
963 *
964 * @param trace         The input trace to be destroyed
965 *
966 */
967DLLEXPORT void trace_destroy(libtrace_t *trace);
968
969/** Close a dummy trace file, freeing up any resources it may have been using
970 * @param trace         The dummy trace to be destroyed
971 */
972DLLEXPORT void trace_destroy_dead(libtrace_t *trace);
973
974/** Close an output trace, freeing up any resources it may have been using
975 * @param trace         The output trace to be destroyed
976 */
977DLLEXPORT void trace_destroy_output(libtrace_out_t *trace);
978
979/** Check (and clear) the current error state of an input trace
980 * @param trace         The input trace to check the error state on
981 * @return The current error status and message
982 *
983 * This reads and returns the current error state and sets the current error
984 * to "no error".
985 */
986DLLEXPORT libtrace_err_t trace_get_err(libtrace_t *trace);
987
988/** Indicate if there has been an error on an input trace
989 * @param trace         The input trace to check the error state on
990 * @return true if an error has occurred, false otherwise
991 *
992 * @note This does not clear the error status, and only returns true or false.
993 */
994DLLEXPORT bool trace_is_err(libtrace_t *trace);
995
996/** Outputs the error message for an input trace to stderr and clear the error
997 * status.
998 * @param trace         The input trace with the error to output
999 * @param msg           The message to prepend to the error
1000 *
1001 * This function does clear the error status.
1002 */
1003DLLEXPORT void trace_perror(libtrace_t *trace, const char *msg,...) PRINTF(2,3);
1004
1005/** Checks (and clears) the current error state for an output trace
1006 * @param trace         The output trace to check the error state on
1007 * @return The current error status and message
1008 *
1009 * This reads and returns the current error state and sets the current error
1010 * to "no error".
1011 */
1012DLLEXPORT libtrace_err_t trace_get_err_output(libtrace_out_t *trace);
1013
1014/** Indicates if there is an error on an output trace
1015 * @param trace         The output trace to check the error state on
1016 * @return true if an error has occurred, false otherwise.
1017 *
1018 * This does not clear the error status, and only returns true or false.
1019 */
1020DLLEXPORT bool trace_is_err_output(libtrace_out_t *trace);
1021
1022/** Outputs the error message for an output trace to stderr and clear the error
1023 * status.
1024 * @param trace         The output trace with the error to output
1025 * @param msg           The message to prepend to the error
1026 * This function does clear the error status.
1027 */
1028DLLEXPORT void trace_perror_output(libtrace_out_t *trace, const char *msg,...)
1029        PRINTF(2,3);
1030
1031/** Returns the number of packets observed on an input trace.
1032 * Includes the number of packets counted as early as possible, before
1033 * filtering, and includes dropped packets.
1034 *
1035 * @param trace         The input trace to examine
1036 * @returns The number of packets seen at the capture point before filtering.
1037 *
1038 * If the number is not known, this function will return UINT64_MAX
1039 */
1040DLLEXPORT
1041uint64_t trace_get_received_packets(libtrace_t *trace);
1042
1043/** Returns the number of packets that were captured, but discarded for not
1044 * matching a provided filter.
1045 *
1046 * @param trace         The input trace to examine
1047 * @returns The number of packets that were successfully captured, but filtered
1048 *
1049 * If the number is not known, this function will return UINT64_MAX
1050 */
1051DLLEXPORT
1052uint64_t trace_get_filtered_packets(libtrace_t *trace);
1053
1054/** Returns the number of packets that have been dropped on an input trace due
1055 * to lack of buffer space on the capturing device.
1056 *
1057 * @param trace         The input trace to examine
1058 * @returns The number of packets captured, but dropped due to buffer overruns
1059 *
1060 * If the number is not known, this function will return UINT64_MAX
1061 */
1062DLLEXPORT
1063uint64_t trace_get_dropped_packets(libtrace_t *trace);
1064
1065/** Returns the number of packets that have been read from the input trace using
1066 * trace_read_packet().
1067 *
1068 * @param trace         The input trace to examine
1069 * @returns The number of packets that have been read by the libtrace user.
1070 *
1071 * If the number is not known, this function will return UINT64_MAX
1072 */
1073DLLEXPORT
1074uint64_t trace_get_accepted_packets(libtrace_t *trace);
1075
1076
1077/*@}*/
1078
1079/** @name Reading / Writing packets
1080 * These members deal with creating, reading and writing packets
1081 *
1082 * @{
1083 */
1084
1085/** Create a new packet object
1086 *
1087 * @return A pointer to an initialised libtrace_packet_t object
1088 */
1089DLLEXPORT libtrace_packet_t *trace_create_packet(void);
1090
1091/** Copy a packet object
1092 * @param packet        The source packet to copy
1093 * @return A new packet which has the same content as the source packet
1094 *
1095 * @note This always involves a copy, which can be slow.  Use of this
1096 * function should be avoided where possible.
1097 *
1098 * @par The reason you would want to use this function is that a zerocopied
1099 * packet from a device will be stored using memory owned by the device which
1100 * may be a limited resource. Copying the packet will ensure that the packet
1101 * is now stored in memory owned and managed by libtrace.
1102 */
1103DLLEXPORT libtrace_packet_t *trace_copy_packet(const libtrace_packet_t *packet);
1104
1105/** Destroy a packet object
1106 * @param packet        The packet to be destroyed
1107 *
1108 */
1109DLLEXPORT void trace_destroy_packet(libtrace_packet_t *packet);
1110
1111
1112/** Read the next packet from an input trace
1113 *
1114 * @param trace         The libtrace opaque pointer for the input trace
1115 * @param packet        The packet opaque pointer
1116 * @return 0 on EOF, negative value on error, number of bytes read when successful.
1117 *
1118 * @note The number of bytes read is usually (but not always) the same as
1119 * trace_get_framing_length()+trace_get_capture_length() depending on the
1120 * trace format.
1121 *
1122 * @note The trace must have been started with trace_start before calling
1123 * this function
1124 *
1125 * @note When reading from a live capture, this function will block until a
1126 * packet is observed on the capture interface. The libtrace event API
1127 * (e.g. trace_event()) should be used if non-blocking operation is required.
1128 */
1129DLLEXPORT int trace_read_packet(libtrace_t *trace, libtrace_packet_t *packet);
1130
1131/** Event types
1132 * see \ref libtrace_eventobj_t and \ref trace_event
1133 */
1134typedef enum {
1135        TRACE_EVENT_IOWAIT,     /**< Wait on the given file descriptor */
1136        TRACE_EVENT_SLEEP,      /**< Sleep for the given amount of time */
1137        TRACE_EVENT_PACKET,     /**< Packet has been read from input trace */
1138        TRACE_EVENT_TERMINATE   /**< End of input trace */
1139} libtrace_event_t;
1140
1141/** Structure returned by libtrace_event explaining what the current event is */
1142typedef struct libtrace_eventobj_t {
1143        libtrace_event_t type; /**< Event type (iowait,sleep,packet) */
1144       
1145        /** If the event is IOWAIT, the file descriptor to wait on */
1146        int fd;               
1147        /** If the event is SLEEP, the amount of time to sleep for in seconds */
1148        double seconds;       
1149        /** If the event is PACKET, the value returned by trace_read_packet() */
1150        int size;
1151} libtrace_eventobj_t;
1152
1153/** Processes the next libtrace event from an input trace.
1154 * @param trace The libtrace opaque pointer for the input trace
1155 * @param packet The libtrace_packet opaque pointer to use for reading packets
1156 * @return A libtrace_event struct containing the event type and details of the event.
1157 *
1158 * Type can be:
1159 *  TRACE_EVENT_IOWAIT  Waiting on I/O on a file descriptor
1160 *  TRACE_EVENT_SLEEP   Wait a specified amount of time for the next event
1161 *  TRACE_EVENT_PACKET  Packet was read from the trace
1162 *  TRACE_EVENT_TERMINATE Trace terminated (perhaps with an error condition)
1163 */
1164DLLEXPORT libtrace_eventobj_t trace_event(libtrace_t *trace,
1165                libtrace_packet_t *packet);
1166
1167
1168/** Write one packet out to the output trace
1169 *
1170 * @param trace         The libtrace_out opaque pointer for the output trace
1171 * @param packet        The packet opaque pointer of the packet to be written
1172 * @return The number of bytes written out, if zero or negative then an error has occured.
1173 */
1174DLLEXPORT int trace_write_packet(libtrace_out_t *trace, libtrace_packet_t *packet);
1175
1176/** Gets the capture format for a given packet.
1177 * @param packet        The packet to get the capture format for.
1178 * @return The capture format of the packet
1179 *
1180 * @note Due to ability to convert packets between formats relatively easily
1181 * in Libtrace, the format of the packet right now may not be the format that
1182 * the packet was originally captured with.
1183 */
1184DLLEXPORT
1185enum base_format_t trace_get_format(struct libtrace_packet_t *packet);
1186
1187/** Construct a libtrace packet from a buffer containing the packet payload.
1188 * @param[in,out] packet        Libtrace Packet object to update with the new
1189 *                              data.
1190 * @param linktype              The linktype of the packet data.
1191 * @param[in] data              The packet data (including linklayer).
1192 * @param len                   Length of packet data provided in the buffer.
1193 *
1194 * @note The constructed packet will be in the PCAP format.
1195 *
1196 * @note To be useful, the provided buffer must start with the layer 2 header
1197 * (or a metadata header, if desired).
1198 */
1199DLLEXPORT
1200void trace_construct_packet(libtrace_packet_t *packet,
1201                libtrace_linktype_t linktype, const void *data, uint16_t len);
1202
1203/*@}*/
1204
1205/** @name Protocol decodes
1206 * These functions locate and return a pointer to various headers inside a
1207 * packet
1208 *
1209 * A packet is divided up into several "layers.":
1210 *
1211 * @li Framing header -- This is the header provided by the capture format
1212 * itself rather than anything that was sent over the network. This provides
1213 * basic details about the packet record including capture lengths, wire
1214 * lengths, timestamps, direction information and any other metadata that is
1215 * part of the capture format. 
1216 *
1217 * @li Metadata header (optional) -- A header containing metadata about a
1218 * packet that was captured, but the metadata was not transmitted over the
1219 * wire.  Some examples include RadioTap and Linux_sll headers.  This can be
1220 * retrieved by trace_get_packet_meta(), or skipped using
1221 * trace_get_payload_from_meta(). There may be multiple "metadata" headers on
1222 * a packet.
1223 *
1224 * @li Layer 2/Link layer/Datalink header -- This can be retrieved by
1225 * trace_get_layer2(), or skipped using trace_get_payload_from_layer2().
1226 *
1227 * @li Layer 3/IP/IPv6 -- This can be retrieved by trace_get_layer3().  As a
1228 * convenience trace_get_ip()/trace_get_ip6() can be used to find an IPv4/IPv6
1229 * header.
1230 *
1231 * @li Layer 5/transport -- These are protocols carried in IPv4/IPv6 frames.
1232 * These can be retrieved using trace_get_transport().
1233 *
1234 * @{
1235 */
1236
1237
1238/** Gets a pointer to the first byte of the packet as it was captured and
1239 * returns its corresponding linktype and capture length.
1240 *
1241 * Use this function instead of the deprecated trace_get_link().
1242 *
1243 * @param packet The packet to get the buffer from
1244 * @param[out] linktype The linktype of the returned pointer
1245 * @param[out] remaining The capture length (the number of captured bytes from
1246 * the returned pointer)
1247 * @return A pointer to the first byte of the packet
1248 */
1249DLLEXPORT void *trace_get_packet_buffer(const libtrace_packet_t *packet,
1250                libtrace_linktype_t *linktype, uint32_t *remaining);
1251
1252/** Get a pointer to the link layer for a given packet
1253 * @param packet        The packet to get the link layer for
1254 *
1255 * @return A pointer to the link layer, or NULL if there is no link layer
1256 *
1257 * @deprecated This function is deprecated: Use trace_get_packet_buffer() or
1258 * one of the trace_get_layer*() functions instead.
1259 * @note You should call trace_get_link_type to find out what type of link
1260 * layer has been returned to you.
1261 */
1262DLLEXPORT SIMPLE_FUNCTION DEPRECATED
1263void *trace_get_link(const libtrace_packet_t *packet);
1264
1265/** Get a pointer to the IPv4 header (if any) for a given packet
1266 * @param packet        The packet to get the IPv4 header for
1267 *
1268 * @return A pointer to the IPv4 header, or NULL if there is no IPv4 header
1269 *
1270 * If a partial IP header is present, i.e. the packet has been truncated before
1271 * the end of the IP header, this function will return NULL.
1272 *
1273 * You should consider using \ref trace_get_layer3 instead of this function.
1274 */
1275DLLEXPORT SIMPLE_FUNCTION
1276libtrace_ip_t *trace_get_ip(libtrace_packet_t *packet);
1277
1278/** get a pointer to the IPv6 header (if any)
1279 * @param packet        The packet to get the IPv6 header for
1280 *
1281 * @return A pointer to the IPv6 header, or NULL if there is no IPv6 header
1282 *
1283 * If a partial IPv6 header is present, i.e. the packet has been truncated
1284 * before the end of the IP header, this function will return NULL.
1285 *
1286 * You should consider using \ref trace_get_layer3 instead of this function.
1287 */
1288DLLEXPORT SIMPLE_FUNCTION
1289libtrace_ip6_t *trace_get_ip6(libtrace_packet_t *packet);
1290
1291/** Return a pointer to the first metadata header in a packet, if present.
1292 *
1293 * This function takes a pointer to a libtrace packet and if any metadata
1294 * headers exist, returns a pointer to the first one, along with its
1295 * corresponding linktype.
1296 *
1297 * If no metadata headers exist in the packet, NULL is returned.
1298 *
1299 * A metadata header is a header that was prepended by the capturing device,
1300 * such as a Linux SLL header, or a Radiotap wireless monitoring header.
1301 * Subsequent metadata headers may be accessed with the
1302 * trace_get_payload_from_meta(...) function.
1303 *
1304 * @param packet The libtrace packet
1305 * @param[out] linktype The linktype of the returned metadata header
1306 * @param[out] remaining The number of bytes captured after the returned
1307 * pointer.
1308 * @return A pointer to the first metadata header, or NULL if there are no
1309 * metadata headers present.
1310 *
1311 * remaining may be NULL, however linktype must be provided.
1312 */
1313DLLEXPORT void *trace_get_packet_meta(const libtrace_packet_t *packet,
1314                libtrace_linktype_t *linktype,
1315                uint32_t *remaining);
1316
1317/** Returns the payload of a metadata header.
1318 *
1319 * This function takes a pointer to the start of a metadata header (either
1320 * obtained via trace_get_packet_meta(...) or by a previous call to
1321 * trace_get_payload_from_meta(...)) along with its corresponding linktype and
1322 * returns the payload, i.e. the next header. It will also update the linktype
1323 * parameter to indicate the type of payload.
1324 * 
1325 * If the linktype indicates that the header passed in is not a metadata
1326 * header, the function returns NULL to indicate this. The linktype remains
1327 * unchanged in this case.
1328 *
1329 * This function allows the user to iterate through metadata headers which are
1330 * sometimes present before the actual packet as it was received on the wire.
1331 * Examples of metadata headers include the Linux SLL header and the Radiotap
1332 * wireless monitoring header.
1333 *
1334 * If the metadata header passed into this function is truncated, this
1335 * function will return NULL, and remaining will be set to 0.
1336 *
1337 * If there are 0 bytes of payload following the provided metadata header, the
1338 * function will return a pointer to where the header would otherwise be and
1339 * remaining will be 0.
1340 *
1341 * Therefore, be sure to check the value of remaining after calling this
1342 * function!
1343 *
1344 * @param[in] meta A pointer to a metadata header
1345 * @param[in,out] linktype The linktype of meta (updated to indicate the
1346 * linktype of the returned header if applicable).
1347 * @param[in,out] remaining The number of bytes after the meta pointer.
1348 * @return A pointer to the payload of the metadata header. If meta is not a
1349 * pointer to a metadata header, NULL is returned and linktype remains
1350 * unchanged.
1351 *
1352 * All parameters are mandatory.
1353 */
1354DLLEXPORT void *trace_get_payload_from_meta(const void *meta,
1355                libtrace_linktype_t *linktype,
1356                uint32_t *remaining);
1357
1358
1359/** Get a pointer to the layer 2 header. Generally this is the first byte of the
1360 * packet as it was seen on the wire.
1361 *
1362 * This function takes a libtrace packet and skips over any metadata headers if
1363 * present (such as Linux SLL or Radiotap) and returns a pointer to the first
1364 * byte of the packet that was actually received by the network interface.
1365 *
1366 * @param packet The libtrace packet to find the layer 2 header for
1367 * @param[out] linktype The linktype of the returned layer 2 header
1368 * @param[out] remaining The number of bytes left in the packet after the
1369 * returned pointer.
1370 * @return A pointer to the first byte of the packet as it was seen on the
1371 * wire. If no layer 2 header is present, this function will return NULL.
1372 *
1373 * remaining may be NULL, otherwise it will be filled in by the function.
1374 */
1375DLLEXPORT void *trace_get_layer2(const libtrace_packet_t *packet,
1376                libtrace_linktype_t *linktype,
1377                uint32_t *remaining);
1378
1379/** Gets a pointer to the next header following a layer 2 header
1380 *
1381 * @param l2                    The pointer to the current layer 2 header
1382 * @param linktype              The type of the layer 2 header
1383 * @param[out] ethertype        An optional output variable of the ethernet type of the new header
1384 * @param[in,out] remaining     Updated with the number of captured bytes
1385                                remaining
1386 *
1387 * @return A pointer to the header following the provided layer 2 header, or
1388 * NULL if no subsequent header is present.
1389 *
1390 * Remaining must point to the number of bytes captured from the layer 2 header
1391 * and beyond.  It will be decremented by the number of bytes skipped to find
1392 * the payload.
1393 *
1394 * If the layer 2 header is complete but there are zero bytes of payload after
1395 * the end of the header, a pointer to where the payload would be is returned
1396 * and remaining will be set to 0.  If the layer 2 header is incomplete
1397 * (truncated), then NULL is returned and remaining will be set to 0.
1398 * Therefore, it is very important to check the value of remaining after
1399 * calling this function.
1400 *
1401 */
1402DLLEXPORT void *trace_get_payload_from_layer2(void *l2,
1403                libtrace_linktype_t linktype,
1404                uint16_t *ethertype,
1405                uint32_t *remaining);
1406
1407
1408/** Get a pointer to the layer 3 (e.g. IP) header.
1409 * @param packet  The libtrace packet to find the layer 3 header for
1410 * @param[out] ethertype The ethertype of the layer 3 header
1411 * @param[out] remaining The amount of captured data remaining in the packet starting from the returned pointer, i.e. including the layer 3 header.
1412 *
1413 * @return A pointer to the layer 3 header. If no layer 3 header is present in
1414 * the packet, NULL is returned. If the layer 3 header is truncated, a valid
1415 * pointer will still be returned so be sure to check the value of remaining
1416 * before attempting to process the returned header.
1417 *
1418 * remaining may be NULL, otherwise it will be set to the number of captured
1419 * bytes after the pointer returned.
1420 */
1421DLLEXPORT
1422void *trace_get_layer3(const libtrace_packet_t *packet,
1423                uint16_t *ethertype, uint32_t *remaining);
1424
1425/** Gets a pointer to the transport layer header (if any)
1426 * @param packet   The libtrace packet to find the transport header for
1427 * @param[out] proto    The protocol present at the transport layer.
1428 * @param[out] remaining The amount of captured data remaining in the packet
1429 * starting from the returned pointer, i.e. including the transport header.
1430 *
1431 * @return A pointer to the transport layer header. If no transport header is
1432 * present in the packet, NULL is returned. If the transport header is
1433 * truncated, a valid pointer will still be returned so be sure to check the
1434 * value of remaining before attempting to process the returned header.
1435 *
1436 * remaining may be NULL, otherwise it will be set to the number of captured
1437 * bytes after the returned pointer.
1438 *
1439 * @note proto may be NULL if proto is unneeded.
1440 */
1441DLLEXPORT void *trace_get_transport(const libtrace_packet_t *packet,
1442                uint8_t *proto, uint32_t *remaining);
1443
1444/** Gets a pointer to the payload following an IPv4 header
1445 * @param ip            The IPv4 Header
1446 * @param[out] proto    The protocol of the header following the IPv4 header
1447 * @param[in,out] remaining Updated with the number of captured bytes remaining
1448 *
1449 * @return A pointer to the transport layer header, or NULL if no subsequent
1450 * header is present.
1451 *
1452 * When calling this function, remaining must contain the number of captured
1453 * bytes remaining in the packet starting from the IPv4 header (including the
1454 * IPv4 header itself).
1455 *
1456 * remaining will be decremented by the size of the IPv4 header (including any
1457 * options). If the IPv4 header is complete but there are zero bytes of payload
1458 * after the IPv4 header, a pointer to where the payload would be is returned
1459 * and remaining will be set to 0.  If the IPv4 header is incomplete, NULL will
1460 * be returned and remaining will be set to 0. Therefore, it is very important
1461 * to check the value of remaining after calling this function.
1462 *
1463 * proto may be NULL, in which case it won't be updated.
1464 *
1465 * @note This is similar to trace_get_transport_from_ip in libtrace2
1466 */
1467DLLEXPORT void *trace_get_payload_from_ip(libtrace_ip_t *ip, uint8_t *proto,
1468                uint32_t *remaining);
1469
1470/** Gets a pointer to the payload following an IPv6 header
1471 * @param ipptr         The IPv6 Header
1472 * @param[out] proto    The protocol of the header following the IPv6 header
1473 * @param[in,out] remaining Updated with the number of captured bytes remaining
1474 *
1475 * @return A pointer to the transport layer header, or NULL if no subsequent
1476 * header is present.
1477 *
1478 * When calling this function, remaining must contain the number of captured
1479 * bytes remaining in the packet starting from the IPv6 header (including the
1480 * IPv6 header itself).
1481 *
1482 * remaining will be decremented by the size of the IPv6 header (including any
1483 * options). If the IPv6 header is complete but there are zero bytes of payload
1484 * after the IPv6 header, a pointer to where the payload would be is returned
1485 * and remaining will be set to 0.  If the IPv6 header is incomplete, NULL will
1486 * be returned and remaining will be set to 0. Therefore, it is very important
1487 * to check the value of remaining after calling this function.
1488 *
1489 * proto may be NULL, in which case it won't be updated.
1490 *
1491 */
1492DLLEXPORT void *trace_get_payload_from_ip6(libtrace_ip6_t *ipptr,
1493                uint8_t *proto, uint32_t *remaining);
1494
1495/** Gets a pointer to the payload following a link header
1496 * @param linkptr       A pointer to the link layer header
1497 * @param linktype      The linktype of the link header being examined
1498 * @param[out] type     An output variable for the ethernet type
1499 * @param[in,out] remaining Updated with the number of captured bytes remaining
1500 *
1501 * @return A pointer to the header following the link header, or NULL if no
1502 * subsequent header is present.
1503 *
1504 * When calling this function, remaining must contain the number of captured
1505 * bytes remaining in the packet starting from the link header (including the
1506 * link header itself). remaining will be updated to contain the number of
1507 * bytes remaining after the link header has been skipped.
1508 *
1509 * @deprecated This function is deprecated: you should be using
1510 * trace_get_payload_from_layer2() or trace_get_payload_from_meta() instead.
1511 *
1512 */
1513DLLEXPORT void *trace_get_payload_from_link(void *linkptr,
1514                libtrace_linktype_t linktype,
1515                uint16_t *type, uint32_t *remaining);
1516
1517/** Gets a pointer to the payload following an 802.1q (VLAN) header.
1518 * @param vlan      A pointer to the VLAN header
1519 * @param[out] type  The ethernet type, replaced with the VLAN ether type
1520 * @param[in,out] remaining Updated with the number of captured bytes remaining
1521 *
1522 * @return A pointer to the header beyond the VLAN header, if one is present.
1523 * Otherwise, returns NULL. 
1524 *
1525 * When calling this function, remaining must contain the number of captured
1526 * bytes remaining in the packet starting from the VLAN header (including the
1527 * VLAN header itself). remaining will be updated to contain the number of
1528 * bytes remaining after the VLAN header has been skipped.
1529 *
1530 * If the VLAN header is complete but there are zero bytes of payload after
1531 * the VLAN header, a pointer to where the payload would be is returned and
1532 * remaining will be set to 0.  If the VLAN header is incomplete, NULL will be
1533 * returned and remaining will be set to 0. Therefore, it is important to check
1534 * the value of remaining after calling this function.
1535 *
1536 * type will be set to the ethertype of the VLAN payload. This parameter is not
1537 * mandatory, but is highly recommended.
1538 *
1539 */
1540DLLEXPORT void *trace_get_payload_from_vlan(
1541                void *vlan, uint16_t *type, uint32_t *remaining);
1542
1543/** Gets a pointer to the payload following an MPLS header.
1544 * @param mpls      A pointer to the MPLS header
1545 * @param[out] type  The ethernet type, replaced by the ether type of the
1546 * returned header - 0x0000 if an Ethernet header is returned
1547 * @param[in,out] remaining Updated with the number of captured bytes remaining
1548 *
1549 * @return A pointer to the header beyond the MPLS label, if one is present.
1550 * Will return NULL if there is not enough bytes remaining to skip past the
1551 * MPLS label.
1552 *
1553 * When calling this function, remaining must contain the number of captured
1554 * bytes remaining in the packet starting from the MPLS header (including the
1555 * MPLS header itself). remaining will be updated to contain the number of
1556 * bytes remaining after the MPLS header has been skipped.
1557 *
1558 * If the MPLS header is complete but there are zero bytes of payload after
1559 * the MPLS header, a pointer to where the payload would be is returned and
1560 * remaining will be set to 0.  If the MPLS header is incomplete, NULL will be
1561 * returned and remaining will be set to 0. Therefore, it is important to check
1562 * the value of remaining after calling this function.
1563 *
1564 * type will be set to the ethertype of the MPLS payload. This parameter is
1565 * mandatory - it may not be NULL.
1566 *
1567 * @note This function will only remove one MPLS label at a time - the type
1568 * will be set to 0x8847 if there is another MPLS label following the one
1569 * skipped by this function.
1570 *
1571 */
1572DLLEXPORT void *trace_get_payload_from_mpls(
1573                void *mpls, uint16_t *type, uint32_t *remaining);
1574
1575/** Gets a pointer to the payload following a PPPoE header
1576 * @param pppoe      A pointer to the PPPoE header
1577 * @param[out] type  The ethernet type, replaced by the ether type of the
1578 * returned header - 0x0000 if an Ethernet header is returned
1579 * @param[in,out] remaining  Updated with the number of captured bytes remaining
1580 *
1581 * @return A pointer to the header beyond the PPPoE header. NOTE that this
1582 * function will also skip over the PPP header that will immediately follow
1583 * the PPPoE header. This function will return NULL if there are not enough
1584 * bytes remaining to skip past both the PPPoE and PPP headers.
1585 *
1586 * When calling this function, remaining must contain the number of captured
1587 * bytes remaining in the packet starting from the PPPoE header (including the
1588 * PPPoE header itself). remaining will be updated to contain the number of
1589 * bytes remaining after the PPPoE and PPP headers have been removed.
1590 *
1591 * If the PPPoE and PPP headers are complete but there are zero bytes of
1592 * payload after the PPP header, a pointer to where the payload would be is
1593 * returned and remaining will be set to 0.  If the PPPoE or PPP header is
1594 * incomplete, NULL will be returned and remaining will be set to 0. Therefore,
1595 * it is important to check the value of remaining after calling this function.
1596 *
1597 * type will be set to the ether type of the PPP payload. This parameter is
1598 * mandatory - it may not be NULL.
1599 *
1600 */
1601DLLEXPORT void *trace_get_payload_from_pppoe(
1602                void *pppoe, uint16_t *type, uint32_t *remaining);
1603
1604/** Gets a pointer to the payload following a TCP header
1605 * @param tcp           A pointer to the TCP header
1606 * @param[in,out] remaining Updated with the number of captured bytes remaining
1607 *
1608 * @return A pointer to the TCP payload, or NULL if the TCP header is truncated.
1609 *
1610 * When calling this function, remaining must contain the number of captured
1611 * bytes remaining in the packet starting from the TCP header (including the
1612 * TCP header itself). remaining will be updated to contain the number of
1613 * bytes remaining after the TCP header has been skipped.
1614 *
1615 * If the TCP header is complete but there are zero bytes of payload after
1616 * the TCP header, a pointer to where the payload would be is returned and
1617 * remaining will be set to 0.  If the TCP header is incomplete, NULL will be
1618 * returned and remaining will be set to 0. Therefore, it is important to check
1619 * the value of remaining after calling this function.
1620 *
1621 */
1622DLLEXPORT void *trace_get_payload_from_tcp(libtrace_tcp_t *tcp,
1623                uint32_t *remaining);
1624
1625/** Gets a pointer to the payload following a UDP header
1626 * @param udp           A pointer to the UDP header
1627 * @param[in,out] remaining Updated with the number of captured bytes remaining
1628 *
1629 * @return A pointer to the UDP payload, or NULL if the UDP header is truncated.
1630 *
1631 * When calling this function, remaining must contain the number of captured
1632 * bytes remaining in the packet starting from the UDP header (including the
1633 * UDP header itself). remaining will be updated to contain the number of
1634 * bytes remaining after the UDP header has been skipped.
1635 *
1636 * If the UDP header is complete but there are zero bytes of payload after
1637 * the UDP header, a pointer to where the payload would be is returned and
1638 * remaining will be set to 0.  If the UDP header is incomplete, NULL will be
1639 * returned and remaining will be set to 0. Therefore, it is important to check
1640 * the value of remaining after calling this function.
1641 *
1642 */
1643DLLEXPORT void *trace_get_payload_from_udp(libtrace_udp_t *udp, uint32_t *remaining);
1644
1645/** Gets a pointer to the payload following a ICMP header
1646 * @param icmp           A pointer to the ICMP header
1647 * @param[in,out] remaining Updated with the number of captured bytes remaining
1648 *
1649 * @return A pointer to the ICMP payload, or NULL if the ICMP header is
1650 * truncated.
1651 *
1652 * When calling this function, remaining must contain the number of captured
1653 * bytes remaining in the packet starting from the ICMP header (including the
1654 * ICMP header itself). remaining will be updated to contain the number of
1655 * bytes remaining after the ICMP header has been skipped.
1656 *
1657 * If the ICMP header is complete but there are zero bytes of payload after
1658 * the ICMP header, a pointer to where the payload would be is returned and
1659 * remaining will be set to 0.  If the ICMP header is incomplete, NULL will be
1660 * returned and remaining will be set to 0. Therefore, it is important to check
1661 * the value of remaining after calling this function.
1662 *
1663 * @note In the case of some ICMP messages, the payload may be the IP header
1664 * from the packet that triggered the ICMP message.
1665 *
1666 */
1667DLLEXPORT void *trace_get_payload_from_icmp(libtrace_icmp_t *icmp,
1668                uint32_t *remaining);
1669
1670/** Get a pointer to the TCP header (if present)
1671 * @param packet        The packet to get the TCP header from
1672 *
1673 * @return A pointer to the TCP header, or NULL if there is not a complete TCP
1674 * header present in the packet.
1675 *
1676 * This is a short-cut function enabling quick and easy access to the TCP
1677 * header if that is all you care about. However, we recommend the use of the
1678 * more generic trace_get_transport() function instead.
1679 *
1680 * @note Unlike trace_get_transport(), this function will return NULL if the
1681 * TCP header is incomplete or truncated.
1682 */
1683DLLEXPORT SIMPLE_FUNCTION
1684libtrace_tcp_t *trace_get_tcp(libtrace_packet_t *packet);
1685
1686/** Get a pointer to the TCP header following an IPv4 header (if present)
1687 * @param ip            The IP header to find the subsequent TCP header for
1688 * @param[in,out] remaining Updated with the number of captured bytes remaining
1689 *
1690 * @return A pointer to the TCP header, or NULL if no TCP header is present in
1691 * the packet.
1692 *
1693 * When calling this function, remaining must contain the number of captured
1694 * bytes remaining in the packet starting from the IP header (including the
1695 * IP header itself). remaining will be updated to contain the number of
1696 * bytes remaining after the IP header has been skipped.
1697 *
1698 * If the IP header is complete but there are zero bytes of payload after
1699 * the IP header, a pointer to where the payload would be is returned and
1700 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
1701 * returned and remaining will be set to 0. Therefore, it is important to check
1702 * the value of remaining after calling this function.
1703 *
1704 * @note This function is rather redundant now that the layer 3 header is
1705 * cached. There should be no performance advantage for the user to call this
1706 * function over just calling trace_get_transport().
1707 *
1708 * @note The last parameter has changed from libtrace2
1709 */
1710DLLEXPORT SIMPLE_FUNCTION
1711libtrace_tcp_t *trace_get_tcp_from_ip(libtrace_ip_t *ip, uint32_t *remaining);
1712
1713/** Get a pointer to the UDP header (if present)
1714 * @param packet        The packet to get the UDP header from
1715 *
1716 * @return A pointer to the UDP header, or NULL if there is not a complete UDP
1717 * header present in the packet.
1718 *
1719 * This is a short-cut function enabling quick and easy access to the UDP
1720 * header if that is all you care about. However, we recommend the use of the
1721 * more generic trace_get_transport() function instead.
1722 *
1723 * @note Unlike trace_get_transport(), this function will return NULL if the
1724 * UDP header is incomplete or truncated.
1725 */
1726DLLEXPORT SIMPLE_FUNCTION
1727libtrace_udp_t *trace_get_udp(libtrace_packet_t *packet);
1728
1729/** Get a pointer to the UDP header following an IPv4 header (if present)
1730 * @param ip            The IP header to find the subsequent UDP header for
1731 * @param[in,out] remaining Updated with the number of captured bytes remaining
1732 *
1733 * @return A pointer to the UDP header, or NULL if no UDP header is present in
1734 * the packet.
1735 *
1736 * When calling this function, remaining must contain the number of captured
1737 * bytes remaining in the packet starting from the IP header (including the
1738 * IP header itself). remaining will be updated to contain the number of
1739 * bytes remaining after the IP header has been skipped.
1740 *
1741 * If the IP header is complete but there are zero bytes of payload after
1742 * the IP header, a pointer to where the payload would be is returned and
1743 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
1744 * returned and remaining will be set to 0. Therefore, it is important to check
1745 * the value of remaining after calling this function.
1746 *
1747 * @note This function is rather redundant now that the layer 3 header is
1748 * cached. There should be no performance advantage for the user to call this
1749 * function over just calling trace_get_transport().
1750 *
1751 * @note The last parameter has changed from libtrace2
1752 */
1753DLLEXPORT SIMPLE_FUNCTION
1754libtrace_udp_t *trace_get_udp_from_ip(libtrace_ip_t *ip,uint32_t *remaining);
1755
1756/** Get a pointer to the ICMP header (if present)
1757 * @param packet        The packet to get the ICMP header from
1758 *
1759 * @return A pointer to the ICMP header, or NULL if there is not a complete
1760 * ICMP header present in the packet.
1761 *
1762 * This is a short-cut function enabling quick and easy access to the ICMP
1763 * header if that is all you care about. However, we recommend the use of the
1764 * more generic trace_get_transport() function instead.
1765 *
1766 * @note Unlike trace_get_transport(), this function will return NULL if the
1767 * ICMP header is incomplete or truncated.
1768 */
1769DLLEXPORT SIMPLE_FUNCTION
1770libtrace_icmp_t *trace_get_icmp(libtrace_packet_t *packet);
1771
1772/** Get a pointer to the ICMP header following an IPv4 header (if present)
1773 * @param ip            The IP header to find the subsequent ICMP header for
1774 * @param[in,out] remaining Updated with the number of captured bytes remaining
1775 *
1776 * @return A pointer to the ICMP header, or NULL if no UDP header is present in
1777 * the packet.
1778 *
1779 * When calling this function, remaining must contain the number of captured
1780 * bytes remaining in the packet starting from the IP header (including the
1781 * IP header itself). remaining will be updated to contain the number of
1782 * bytes remaining after the IP header has been skipped.
1783 *
1784 * If the IP header is complete but there are zero bytes of payload after
1785 * the IP header, a pointer to where the payload would be is returned and
1786 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
1787 * returned and remaining will be set to 0. Therefore, it is important to check
1788 * the value of remaining after calling this function.
1789 *
1790 * @note This function is rather redundant now that the layer 3 header is
1791 * cached. There should be no performance advantage for the user to call this
1792 * function over just calling trace_get_transport().
1793 *
1794 * @note The last parameter has changed from libtrace2
1795 */
1796DLLEXPORT SIMPLE_FUNCTION
1797libtrace_icmp_t *trace_get_icmp_from_ip(libtrace_ip_t *ip,uint32_t *remaining);
1798
1799/** Gets the destination MAC address for a given packet
1800 * @param packet        The packet to extract the destination MAC address from
1801 *
1802 * @return A pointer to the destination MAC address field in the layer 2
1803 * header, (or NULL if there is no destination MAC address or layer 2 header
1804 * available)
1805 *
1806 * @note This is a zero-copy function, so the memory that the returned pointer
1807 * points to is part of the packet itself.
1808 */
1809DLLEXPORT SIMPLE_FUNCTION
1810uint8_t *trace_get_destination_mac(libtrace_packet_t *packet);
1811
1812/** Gets the source MAC address for a given packet
1813 * @param packet        The packet to extract the source MAC address from
1814 *
1815 * @return A pointer to the source MAC address field in the layer 2
1816 * header, (or NULL if there is no source MAC address or layer 2 header
1817 * available)
1818 *
1819 * @note This is a zero-copy function, so the memory that the returned pointer
1820 * points to is part of the packet itself.
1821 */
1822DLLEXPORT SIMPLE_FUNCTION
1823uint8_t *trace_get_source_mac(libtrace_packet_t *packet);
1824
1825/** Get the source IP address for a given packet
1826 * @param packet        The packet to extract the source IP address from
1827 * @param addr          A pointer to a sockaddr structure to store the address
1828 *                      in. If NULL, static storage is used instead.
1829 * @return A pointer to a sockaddr holding a v4 or v6 IP address or on some
1830 * platforms a sockaddr holding a MAC address. Returns NULL if no source IP
1831 * address was available.
1832 *
1833 * @note The best way to use this function is to pass in a pointer to the
1834 * struct sockaddr_storage for the addr parameter. This will avoid problems
1835 * with trying to shoe-horn an IPv6 address into a sockaddr that only supports
1836 * IPv4.
1837 */
1838DLLEXPORT SIMPLE_FUNCTION
1839struct sockaddr *trace_get_source_address(const libtrace_packet_t *packet,
1840                struct sockaddr *addr);
1841
1842/** Get the destination IP address for a given packet
1843 * @param packet        The packet to extract the destination IP address from
1844 * @param addr          A pointer to a sockaddr structure to store the address
1845 *                      in. If NULL, static storage is used instead.
1846 * @return A pointer to a sockaddr holding a v4 or v6 IP address or on some
1847 * platforms a sockaddr holding a MAC address. Returns NULL if no destination
1848 * IP address was available.
1849 *
1850 * @note The best way to use this function is to pass in a pointer to the
1851 * struct sockaddr_storage for the addr parameter. This will avoid problems
1852 * with trying to shoe-horn an IPv6 address into a sockaddr that only supports
1853 * IPv4.
1854 */
1855DLLEXPORT SIMPLE_FUNCTION
1856struct sockaddr *trace_get_destination_address(const libtrace_packet_t *packet,
1857                struct sockaddr *addr);
1858
1859
1860/** Parses an IP or TCP option
1861 * @param[in,out] ptr   The pointer to the current option
1862 * @param[in,out] len   The total length of all the remaining options
1863 * @param[out] type     The type of the option
1864 * @param[out] optlen   The length of the option
1865 * @param[out] data     The data of the option
1866 *
1867 * @return bool true if there is another option (and the fields are filled in)
1868 *               or false if this was the last option.
1869 *
1870 * This updates ptr to point to the next option after this one, and updates
1871 * len to be the number of bytes remaining in the options area.  Type is updated
1872 * to be the code of this option, and data points to the data of this option,
1873 * with optlen saying how many bytes there are.
1874 *
1875 * @note Beware of fragmented packets.
1876 */
1877DLLEXPORT int trace_get_next_option(unsigned char **ptr,int *len,
1878                        unsigned char *type,
1879                        unsigned char *optlen,
1880                        unsigned char **data);
1881
1882/*@}*/
1883
1884/** @name Time
1885 * These functions deal with the timestamp describing when a packet was
1886 * captured and can convert it into various formats
1887 * @{
1888 */
1889
1890/** Get the packet timestamp in the DAG time format
1891 * @param packet        The packet to extract the timestamp from
1892 *
1893 * @return a 64 bit timestamp in DAG ERF format (upper 32 bits are the seconds
1894 * past 1970-01-01, the lower 32bits are partial seconds)
1895 */
1896DLLEXPORT SIMPLE_FUNCTION
1897uint64_t trace_get_erf_timestamp(const libtrace_packet_t *packet);
1898
1899/** Get the packet timestamp as a struct timeval
1900 * @param packet        The packet to extract the timestamp from
1901 *
1902 * @return The time that this packet was captured in a struct timeval
1903 */
1904DLLEXPORT SIMPLE_FUNCTION
1905struct timeval trace_get_timeval(const libtrace_packet_t *packet);
1906
1907/** Get the packet timestamp as a struct timespec
1908 * @param packet        The packet to extract the timestamp from
1909 *
1910 * @return The time that this packet was captured in a struct timespec
1911 */
1912DLLEXPORT SIMPLE_FUNCTION
1913struct timespec trace_get_timespec(const libtrace_packet_t *packet);
1914
1915/** Get the packet timestamp in floating point seconds
1916 * @param packet        The packet to extract the timestamp from
1917 *
1918 * @return time that this packet was seen in 64-bit floating point seconds from
1919 * the UNIX epoch (1970-01-01 00:00:00 UTC).
1920 */
1921DLLEXPORT SIMPLE_FUNCTION
1922double trace_get_seconds(const libtrace_packet_t *packet);
1923
1924/** Seek within an input trace to a time specified in floating point seconds
1925 * @param trace         The input trace to seek within
1926 * @param seconds       The time to seek to, in floating point seconds
1927 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
1928 * the error that occurred.
1929 *
1930 * This will make the next packet read to be the first packet to occur at or
1931 * after the specified time.  This must be called in the configuration state
1932 * (i.e. before trace_start() or after trace_pause()).
1933 *
1934 * The time format accepted by this function is 64-bit floating point seconds
1935 * since the UNIX epoch (1970-01-01 00:00:00 UTC), i.e. the same format as
1936 * trace_get_seconds().
1937 *
1938 * @note This function may be extremely slow.
1939 */
1940DLLEXPORT int trace_seek_seconds(libtrace_t *trace, double seconds);
1941
1942/** Seek within an input trace to a time specified as a timeval
1943 * @param trace         The input trace to seek within
1944 * @param tv            The time to seek to, as a timeval
1945 *
1946 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
1947 * the error that occurred.
1948 *
1949 * This will make the next packet read to be the first packet to occur at or
1950 * after the specified time.  This must be called in the configuration state
1951 * (i.e. before trace_start() or after trace_pause()).
1952 *
1953 * @note This function may be extremely slow.
1954 */
1955DLLEXPORT int trace_seek_timeval(libtrace_t *trace, struct timeval tv);
1956
1957/** Seek within an input trace to a time specified as an ERF timestamp
1958 * @param trace         The input trace to seek within
1959 * @param ts            The time to seek to, as an ERF timestamp
1960 *
1961 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
1962 * the error that occurred.
1963 *
1964 * This will make the next packet read to be the first packet to occur at or
1965 * after the specified time.  This must be called in the configuration state
1966 * (i.e. before trace_start() or after trace_pause()).
1967 *
1968 * The time format accepted by this function is the ERF timestamp, which is a
1969 * 64-bit value where the upper 32 bits are seconds since the UNIX epoch and
1970 * the lower 32 bits are partial seconds.
1971 *
1972 * @note This function may be extremely slow.
1973 */
1974DLLEXPORT int trace_seek_erf_timestamp(libtrace_t *trace, uint64_t ts);
1975
1976/*@}*/
1977
1978/** @name Sizes
1979 * This section deals with finding or setting the various different lengths
1980 * that a packet can have, e.g. capture lengths, wire lengths, etc.
1981 * @{
1982 */
1983/** Get the current size of the packet (in bytes), taking into account any
1984 * truncation or snapping that may have previously been performed.
1985 *
1986 * @param packet        The packet to determine the capture length for
1987 * @return The size of the packet read from the input trace, i.e. what is
1988 * actually available to libtrace at the moment.
1989 *
1990 * @note Most traces are header captures, so this value may not be the same
1991 * as the size of the packet when it was captured. Use trace_get_wire_length()
1992 * to get the original size of the packet.
1993 
1994 * @note This can (and often is) different for different packets in a trace!
1995 
1996 * @note This is sometimes called the "snaplen".
1997 *
1998 * @note The return size refers to the network-level payload of the packet and
1999 * does not include any capture framing headers. For example, an Ethernet
2000 * packet with an empty TCP packet will return sizeof(ethernet_header) +
2001 * sizeof(ip_header) + sizeof(tcp_header), but not the capture format
2002 * (pcap/erf/etc) header.
2003 */
2004DLLEXPORT SIMPLE_FUNCTION
2005size_t trace_get_capture_length(const libtrace_packet_t *packet);
2006
2007/** Get the size of the packet as it was originally seen on the wire (in bytes).
2008 * @param packet        The packet to determine the wire length for
2009 * @return The size of the packet as it was on the wire.
2010 *
2011 * @note This value may not be the same as the capture length, due to
2012 * truncation.
2013 *
2014 * @note trace_get_wire_length \em includes  the Frame Check Sequence. This is
2015 * different behaviour compared to most PCAP-based tools.
2016 *
2017 * @note The return size refers to the network-level payload of the packet and
2018 * does not include any capture framing headers. For example, an Ethernet
2019 * packet with an empty TCP packet will return sizeof(ethernet_header) +
2020 * sizeof(ip_header) + sizeof(tcp_header), but not the capture format
2021 * (pcap/erf/etc) header.
2022 */
2023DLLEXPORT SIMPLE_FUNCTION
2024size_t trace_get_wire_length(const libtrace_packet_t *packet);
2025
2026/** Get the length of the capture framing headers (in bytes).
2027 * @param packet        The packet to determine the framing length for
2028 * @return The size of the capture format header encapsulating the packet.
2029 *
2030 * @note This length corresponds to the difference between the amount of
2031 * memory required to store a captured packet and the capture length reported
2032 * by trace_capture_length()
2033 */
2034DLLEXPORT SIMPLE_FUNCTION
2035size_t trace_get_framing_length(const libtrace_packet_t *packet);
2036
2037/** Get the length of the original payload content of the packet (in bytes).
2038 * @param packet        The packet to determine the payload length for
2039 * @return The size of the packet payload (without headers). Returns 0 if
2040 * unable to calculate payload length correctly.
2041 *
2042 * This function reports the amount of data that followed the transport header
2043 * when the packet was originally captured, i.e. prior to any snapping. Best
2044 * described as the wire length minus the packet headers.
2045 *
2046 * Currently only supports some protocols and will return 0 if an unsupported
2047 * protocol header is encountered, or if one of the headers is truncated.
2048 *
2049 * @note Supports IPv4, IPv6, TCP, UDP and ICMP.
2050 */
2051DLLEXPORT SIMPLE_FUNCTION
2052size_t trace_get_payload_length(const libtrace_packet_t *packet);
2053
2054/** Truncate ("snap") the packet to the suggested length
2055 * @param packet        The packet to truncate
2056 * @param size          The new length of the packet (in bytes)
2057 *
2058 * @return The new capture length of the packet or the original capture
2059 * length of the packet if unchanged.
2060 *
2061 * This function will modify the capture length of the given packet. The wire
2062 * length will not be changed, so you can always determine what the original
2063 * packet size was, prior to the truncation.
2064 *
2065 * @note You can only use this function to decrease the capture length. Any
2066 * attempt to increase capture length will have no effect.
2067 */
2068DLLEXPORT size_t trace_set_capture_length(libtrace_packet_t *packet, size_t size);
2069
2070/*@}*/
2071
2072
2073/** Gets the link layer type for a packet
2074 * @param packet        The packet to extract the link layer type for
2075 * @return A libtrace_linktype_t describing the link layer protocol being used
2076 * by this packet.
2077 */
2078DLLEXPORT SIMPLE_FUNCTION
2079libtrace_linktype_t trace_get_link_type(const libtrace_packet_t *packet);
2080
2081/** Set the direction flag for a packet, if the capture format supports
2082 * direction tagging.
2083 *
2084 * @param packet        The packet to set the direction for
2085 * @param direction     The new direction
2086 * @returns -1 on error, or the direction that was set.
2087 *
2088 * @note Few capture formats actually support direction tagging. Most notably,
2089 * we cannot set the direction on PCAP packets.
2090 */
2091DLLEXPORT libtrace_direction_t trace_set_direction(libtrace_packet_t *packet, libtrace_direction_t direction);
2092
2093/** Get the direction flag for a packet, if it has one.
2094 * @param packet  The packet to get the direction for
2095 *
2096 * @return A value representing the direction flag, or -1 if this is not
2097 * supported by the capture format.
2098 *
2099 * The direction is defined as 0 for packets originating locally (ie, outbound)
2100 * and 1 for packets originating remotely (ie, inbound). Other values are
2101 * possible, which might be overloaded to mean special things for certain
2102 * traces, e.g. in the Waikato traces, 2 is used to represent an "Unknown"
2103 * direction.
2104 *
2105 * For DAG/ERF traces, the direction is extracted from the "Interface" bits in
2106 * the ERF header, which can range from 0 - 3.
2107 */
2108DLLEXPORT SIMPLE_FUNCTION
2109libtrace_direction_t trace_get_direction(const libtrace_packet_t *packet);
2110
2111/** @name BPF
2112 * This section deals with using Berkley Packet Filters to filter input traces
2113 * @{
2114 */
2115/** Creates a BPF filter
2116 * @param filterstring The filter string describing the BPF filter to create
2117 * @return An opaque pointer to a libtrace_filter_t object
2118 *
2119 * @note The filter is not actually compiled at this point, so no correctness
2120 * tests are performed here. trace_create_filter() will always return ok, but
2121 * if the filter is poorly constructed an error will be generated when the
2122 * filter is actually used.
2123 */
2124DLLEXPORT SIMPLE_FUNCTION
2125libtrace_filter_t *trace_create_filter(const char *filterstring);
2126
2127/** Create a BPF filter based on pre-compiled byte-code.
2128 * @param bf_insns      A pointer to the start of the byte-code
2129 * @param bf_len        The number of BPF instructions 
2130 * @return              An opaque pointer to a libtrace_filter_t object
2131 * @note                The supplied byte-code is not checked for correctness.
2132 *                      Instead, incorrect byte-code will generate an error
2133 *                      once the filter is actually used.
2134 * @author              Scott Raynel
2135 */
2136DLLEXPORT libtrace_filter_t *
2137trace_create_filter_from_bytecode(void *bf_insns, unsigned int bf_len);
2138
2139/** Apply a BPF filter to a packet
2140 * @param filter        The filter to be applied       
2141 * @param packet        The packet to be matched against the filter
2142 * @return >0 if the filter matches, 0 if it doesn't, -1 on error.
2143 *
2144 * @note Due to the way BPF filters are built, the filter is not actually
2145 * compiled until the first time trace_create_filter is called. If your filter
2146 * is incorrect, it will generate an error message and assert, exiting the
2147 * program. This behaviour may change to a more graceful handling of this error
2148 * in the future.
2149 */
2150DLLEXPORT int trace_apply_filter(libtrace_filter_t *filter,
2151                const libtrace_packet_t *packet);
2152
2153/** Destroy a BPF filter
2154 * @param filter        The filter to be destroyed
2155 *
2156 * Deallocates all the resources associated with a BPF filter.
2157 */
2158DLLEXPORT void trace_destroy_filter(libtrace_filter_t *filter);
2159/*@}*/
2160
2161/** @name Portability
2162 * This section contains functions that deal with portability issues, e.g. byte
2163 * ordering.
2164 * @{
2165 */
2166
2167/** Converts an ethernet address to a printable string
2168 * @param addr  Ethernet address in network byte order
2169 * @param buf   Buffer to store the ascii representation, or NULL to indicate
2170 * that static storage should be used.
2171 * @return buf, or if buf is NULL then a statically allocated buffer.
2172 *
2173 * This function is similar to the GNU ether_ntoa_r function, with a few
2174 * minor differences.  If NULL is passed as buf, then the function will
2175 * use an internal static buffer. If NULL isn't passed then the function
2176 * will use that buffer instead.
2177 *
2178 * The address pointers returned by trace_get_source_mac() and
2179 * trace_get_destination_mac() can be passed directly into this function.
2180 *
2181 * @note The type of addr isn't struct ether_addr as it is with ether_ntoa_r,
2182 * however it is bit compatible so that a cast will work.
2183 */
2184DLLEXPORT char *trace_ether_ntoa(const uint8_t *addr, char *buf);
2185
2186/** Convert a string to an ethernet address
2187 * @param buf   A string containing an Ethernet address in hex format
2188 * delimited with :'s.
2189 * @param addr  Buffer to store the binary representation, or NULL to indicate
2190 * that static storage should be used.
2191 * @return addr, or if addr is NULL then a statically allocated buffer.
2192 *
2193 * This function is similar to the GNU ether_aton_r function, with a few
2194 * minor differences.  If NULL is passed as addr, then the function will
2195 * use an internal static buffer. If NULL isn't passed then the function will
2196 * use that buffer instead.
2197 *
2198 * The address returned by this function will be in network byte order.
2199 *
2200 * @note the type of addr isn't struct ether_addr as it is with ether_aton_r,
2201 * however it is bit compatible so that a cast will work.
2202 */
2203DLLEXPORT uint8_t *trace_ether_aton(const char *buf, uint8_t *addr);
2204
2205/*@}*/
2206
2207/** @name Ports
2208 * This section contains functions for dealing with port numbers at the
2209 * transport layer.
2210 *
2211 * @{
2212 */
2213
2214/** An indication of which port is the "server" port for a given port pair */
2215typedef enum {
2216        USE_DEST,       /**< Destination port is the server port */
2217        USE_SOURCE      /**< Source port is the server port */
2218} serverport_t;
2219
2220/** Gets the source port for a given packet
2221 * @param packet        The packet to get the source port from
2222 * @return The source port in HOST byte order or 0 if no suitable port number
2223 * can be extracted from the packet.
2224 *
2225 * This function will return 0 if the transport protocol is known not to
2226 * use port numbers, e.g. ICMP. 0 is also returned if no transport header is
2227 * present in the packet or the transport header has been truncated such that
2228 * the port fields are not readable.
2229 *
2230 * @note If the transport protocol is not known by libtrace, the first two
2231 * bytes of the transport header will be treated as the source port field.
2232 */
2233DLLEXPORT SIMPLE_FUNCTION
2234uint16_t trace_get_source_port(const libtrace_packet_t *packet);
2235
2236/** Gets the destination port for a given packet
2237 * @param packet        The packet to get the destination port from
2238 * @return The destination port in HOST byte order or 0 if no suitable port
2239 * number can be extracted from the packet.
2240 *
2241 * This function will return 0 if the transport protocol is known not to
2242 * use port numbers, e.g. ICMP. 0 is also returned if no transport header is
2243 * present in the packet or the transport header has been truncated such that
2244 * the port fields are not readable.
2245 *
2246 * @note If the transport protocol is not known by libtrace, the third and
2247 * fourth bytes of the transport header will be treated as the destination
2248 * port field.
2249 *
2250 */
2251DLLEXPORT SIMPLE_FUNCTION
2252uint16_t trace_get_destination_port(const libtrace_packet_t *packet);
2253
2254/** Hint at which of the two provided ports is the server port.
2255 *
2256 * @param protocol      The IP layer protocol, eg 6 (tcp), 17 (udp)
2257 * @param source        The source port from the packet
2258 * @param dest          The destination port from the packet
2259 *
2260 * @return one of USE_SOURCE or USE_DEST describing on which of the two ports
2261 * is most likely to be the server port.
2262 *
2263 * @note Ports must be provided in HOST byte order!
2264 *
2265 * This function is based almost entirely on heuristics and should not be
2266 * treated as a definitive means of identifying the server port. However, it
2267 * is deterministic, so it is very handy for identifying both halves of the
2268 * same flow.
2269 */
2270DLLEXPORT SIMPLE_FUNCTION
2271int8_t trace_get_server_port(uint8_t protocol, uint16_t source, uint16_t dest);
2272
2273/*@}*/
2274
2275/** @name Wireless trace support
2276 * Functions to access wireless information from packets that have wireless
2277 * monitoring headers such as Radiotap or Prism.
2278 *
2279 * The trace_get_wireless_* functions provide an abstract interface for
2280 * retrieving information from wireless traces. They take a pointer to the
2281 * wireless monitoring header (usually found with trace_get_packet_meta()) and
2282 * the linktype of the header passed in.
2283 *
2284 * All of the trace_get_wireless_* functions return false if the requested
2285 * information was unavailable, or true if it was. The actual data is stored
2286 * in an output variable supplied by the caller. Values returned into the
2287 * output variable will always be returned in host byte order.
2288 * @{
2289 */
2290
2291
2292#ifndef ARPHRD_80211_RADIOTAP
2293/** libc doesn't define this yet, so we have to do so ourselves */
2294#define ARPHRD_80211_RADIOTAP 803
2295#endif
2296
2297/** Get the wireless Timer Synchronisation Function
2298 *
2299 * Gets the value of the timer synchronisation function for this frame, which
2300 * is a value in microseconds indicating the time that the first bit of the
2301 * MPDU was received by the MAC.
2302 *
2303 * @param linkptr The wireless meta header
2304 * @param linktype The linktype of the wireless meta header passed in
2305 * @param[out] tsft The value of the timer synchronisation function.
2306 * @return true if the field was available, false if not.
2307 */
2308DLLEXPORT bool trace_get_wireless_tsft(void *linkptr,
2309        libtrace_linktype_t linktype, uint64_t *tsft);
2310
2311/** Get the wireless data rate
2312 *
2313 * @param linkptr The wireless meta header
2314 * @param linktype The linktype of the wireless meta header passed in
2315 * @param[out] rate The data-rate of the frame in units of 500kbps
2316 * @return true if the field was available, false if not.
2317 */
2318DLLEXPORT bool trace_get_wireless_rate(void *linkptr,
2319        libtrace_linktype_t linktype, uint8_t *rate);
2320
2321/** Get the wireless channel frequency
2322 * @param linkptr The wireless meta header
2323 * @param linktype The linktype of the wireless meta header passed in
2324 * @param[out] freq The frequency in MHz of the channel the frame was
2325 * transmitted or received on.
2326 * @return true if the field was available, false if not.
2327 */
2328DLLEXPORT bool trace_get_wireless_freq(void *linkptr,
2329        libtrace_linktype_t linktype, uint16_t *freq);
2330
2331/** Get the wireless signal strength in dBm
2332 * @param linkptr The wireless meta header
2333 * @param linktype The linktype of the wireless meta header passed in
2334 * @param[out] strength The RF signal power at the antenna, in dB difference
2335 * from 1mW.
2336 * @return true if the field was available, false if not.
2337 */
2338DLLEXPORT bool trace_get_wireless_signal_strength_dbm(void *linkptr,
2339        libtrace_linktype_t linktype, int8_t *strength);
2340
2341/** Get the wireless noise strength in dBm
2342 * @param linkptr The wireless meta header
2343 * @param linktype The linktype of the wireless meta header passed in
2344 * @param[out] strength The RF noise power at the antenna, in dB difference
2345 * from 1mW.
2346 * @return true if the field was available, false if not.
2347 */
2348DLLEXPORT bool trace_get_wireless_noise_strength_dbm(void *linkptr,
2349        libtrace_linktype_t linktype, int8_t *strength);
2350
2351/** Get the wireless signal strength in dB
2352 * @param linkptr The wireless meta header
2353 * @param linktype The linktype of the wireless meta header passed in
2354 * @param[out] strength The RF signal power at the antenna, in dB difference
2355 * from a fixed reference.
2356 * @return true if the field was available, false if not.
2357 */
2358DLLEXPORT bool trace_get_wireless_signal_strength_db(void *linkptr,
2359        libtrace_linktype_t linktype, uint8_t *strength);
2360
2361/** Get the wireless noise strength in dB
2362 * @param linkptr The wireless meta header
2363 * @param linktype The linktype of the wireless meta header passed in
2364 * @param[out] strength The RF noise power at the antenna, in dB difference
2365 * from a fixed reference.
2366 * @return true if the field was available, false if not.
2367 */
2368DLLEXPORT bool trace_get_wireless_noise_strength_db(void *linkptr,
2369        libtrace_linktype_t linktype, uint8_t *strength);
2370
2371/** Get the wireless transmit attenuation
2372 * @param linkptr The wireless meta header
2373 * @param linktype The linktype of the wireless meta header passed in
2374 * @param[out] attenuation The transmit power as a unitless distance from
2375 * maximum power set at factory calibration. 0 indicates maximum transmission
2376 * power.
2377 * @return true if the field was available, false if not.
2378 */
2379DLLEXPORT bool trace_get_wireless_tx_attenuation(void *linkptr,
2380        libtrace_linktype_t linktype, uint16_t *attenuation);
2381
2382/** Get the wireless transmit attenuation in dB
2383 * @param linkptr The wireless meta header
2384 * @param linktype The linktype of the wireless meta header passed in
2385 * @param[out] attenuation The transmit power as dB difference from maximum
2386 * power set at factory calibration. 0 indicates maximum power.
2387 * @return true if the field was available, false if not.
2388 */
2389DLLEXPORT bool trace_get_wireless_tx_attenuation_db(void *linkptr,
2390        libtrace_linktype_t linktype, uint16_t *attenuation);
2391
2392/** Get the wireless transmit power in dBm
2393 * @param linkptr The wireless meta header
2394 * @param linktype The linktype of the wireless meta header passed in
2395 * @param[out] txpower The transmit power as dB from a 1mW reference. This is
2396 * the absolute power level measured at the antenna port. 
2397 * @return true if the field was available, false if not.
2398 */
2399DLLEXPORT bool trace_get_wireless_tx_power_dbm(void *linkptr,
2400                libtrace_linktype_t linktype, int8_t *txpower);
2401
2402/** Get the wireless antenna
2403 * @param linkptr The wireless meta header
2404 * @param linktype The linktype of the wireless meta header passed in
2405 * @param[out] antenna The antenna that was used to transmit or receive the
2406 * frame.
2407 * @return true if the field was available, false if not.
2408 */
2409DLLEXPORT bool trace_get_wireless_antenna(void *linkptr,
2410        libtrace_linktype_t linktype, uint8_t *antenna);
2411
2412/*@}*/
2413
2414#ifdef __cplusplus
2415} /* extern "C" */
2416#endif /* #ifdef __cplusplus */
2417#endif /* LIBTRACE_H_ */
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