source: lib/libtrace.h.in @ c909fad

4.0.1-hotfixescachetimestampsdevelopdpdk-ndagetsilivegetfragoffhelplibtrace4ndag_formatpfringrc-4.0.1rc-4.0.2rc-4.0.3rc-4.0.4ringdecrementfixringperformanceringtimestampfixes
Last change on this file since c909fad was c909fad, checked in by Shane Alcock <salcock@…>, 8 years ago
  • Added checksumming functions for both the IP and transport layer. The functions will calculate the correct checksum for that packet and also return a pointer to the checksum field in the appropriate header so that the caller can either evaluate whether the checksum is correct, replace the existing checksum, or do whatever they want.
  • Also managed to fix a bunch of broken Revision svn tags
  • Property mode set to 100644
File size: 125.0 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        /** Failed to compile a BPF filter */
226        TRACE_ERR_BAD_FILTER    = -9,
227        /** RT communication breakdown */
228        TRACE_ERR_RT_FAILURE    = -10,
229        /** Compression format unsupported */
230        TRACE_ERR_UNSUPPORTED_COMPRESS  = -11
231};
232
233/** Enumeration of DLTs supported by libtrace
234 */
235typedef enum {
236        /** pcap documents this as having the Address Family value in host byte order as the
237          * framing.  Ugly? Yes.
238          */
239        TRACE_DLT_NULL = 0,
240        TRACE_DLT_EN10MB = 1,
241        TRACE_DLT_PPP = 9,
242        TRACE_DLT_ATM_RFC1483 = 11,
243       
244        /** Ok, so OpenBSD has a different value for DLT_RAW as the rest of the planet, so detect
245          * this.  When reading to/from files we should be using TRACE_DLT_LINKTYPE_RAW instead.
246          * When talking about DLT's inside libtrace tho, we should be using /these/ DLT's.
247          */
248#ifdef __OpenBSD__
249        TRACE_DLT_RAW = 14,     
250#else
251        TRACE_DLT_RAW = 12,
252#endif
253        TRACE_DLT_PPP_SERIAL = 50,
254        TRACE_DLT_LINKTYPE_RAW = 101, /**< See TRACE_DLT_RAW for explainations of pain. */
255        TRACE_DLT_C_HDLC = 104,
256        TRACE_DLT_IEEE802_11 = 105,
257        TRACE_DLT_LINUX_SLL = 113,
258        TRACE_DLT_PFLOG = 117,
259        TRACE_DLT_IEEE802_11_RADIO = 127 /**< Radiotap */
260} libtrace_dlt_t ;
261
262/** Enumeration of link layer types supported by libtrace */
263typedef enum {
264    /* TRACE_TYPE_LEGACY = 0            Obsolete */
265       TRACE_TYPE_HDLC_POS = 1,         /**< HDLC over POS */
266       TRACE_TYPE_ETH = 2,              /**< 802.3 style Ethernet */
267       TRACE_TYPE_ATM = 3,              /**< ATM frame */
268       TRACE_TYPE_80211 = 4,            /**< 802.11 frames */
269       TRACE_TYPE_NONE = 5,             /**< Raw IP frames */
270       TRACE_TYPE_LINUX_SLL = 6,        /**< Linux "null" framing */
271       TRACE_TYPE_PFLOG = 7,            /**< FreeBSD's PFlog */
272    /* TRACE_TYPE_LEGACY_DEFAULT        Obsolete */
273       TRACE_TYPE_POS = 9,              /**< Packet-over-SONET */
274    /* TRACE_TYPE_LEGACY_ATM            Obsolete */
275    /* TRACE_TYPE_LEGACY_ETH            Obsolete */
276       TRACE_TYPE_80211_PRISM = 12,     /**< 802.11 Prism frames */
277       TRACE_TYPE_AAL5 = 13,            /**< ATM Adaptation Layer 5 frames */
278       TRACE_TYPE_DUCK = 14,         /**< Pseudo link layer for DUCK packets */
279       TRACE_TYPE_80211_RADIO = 15,  /**< Radiotap + 802.11 */
280       TRACE_TYPE_LLCSNAP = 16,      /**< Raw LLC/SNAP */
281       TRACE_TYPE_PPP = 17,          /**< PPP frames */
282       TRACE_TYPE_METADATA = 18,        /**< WDCAP-style meta-data */
283       TRACE_TYPE_NONDATA = 19          /**< Not a data packet */
284} libtrace_linktype_t;
285
286/** RT protocol base format identifiers.
287 * This is used to describe the capture format of the packet is being sent
288 * using the RT protocol.
289 */
290enum base_format_t {
291        TRACE_FORMAT_ERF          =1,   /**< ERF (DAG capture format) */
292        TRACE_FORMAT_PCAP         =2,   /**< Live PCAP capture */
293        TRACE_FORMAT_PCAPFILE     =3,   /**< PCAP trace file */
294        TRACE_FORMAT_WAG          =4,   /**< WAG live capture (Obsolete) */
295        TRACE_FORMAT_RT           =5,   /**< RT network protocol */
296        TRACE_FORMAT_LEGACY_ATM   =6,   /**< Legacy ERF for ATM capture */
297        TRACE_FORMAT_LEGACY_POS   =7,   /**< Legacy ERF for POS capture */
298        TRACE_FORMAT_LEGACY_ETH   =8,   /**< Legacy ERF for ETH capture */
299        TRACE_FORMAT_LINUX_NATIVE =9,   /**< Linux native interface capture */
300        TRACE_FORMAT_DUCK         =10,  /**< DAG Clock information */
301        TRACE_FORMAT_BPF          =11,  /**< BSD native interface capture */
302        TRACE_FORMAT_TSH          =12,  /**< TSH trace format */
303        TRACE_FORMAT_ATMHDR       =13,  /**< Legacy ATM header capture */
304        TRACE_FORMAT_LEGACY_NZIX  =14,  /**< Legacy format used for NZIX traces */
305        TRACE_FORMAT_LINUX_RING   =15   /**< Linux native interface capture PACKET_MMAP */
306};
307
308/** RT protocol packet types */
309typedef enum {
310        TRACE_RT_HELLO          =1, /**< Connection accepted */
311        TRACE_RT_START          =2, /**< Request for data transmission to begin
312                                    */
313        TRACE_RT_ACK            =3, /**< Data acknowledgement */
314        TRACE_RT_STATUS         =4, /**< Fifo status packet */
315        TRACE_RT_DUCK           =5, /**< Dag duck info packet */
316        TRACE_RT_END_DATA       =6, /**< Server is exiting message */
317        TRACE_RT_CLOSE          =7, /**< Client is exiting message */
318        TRACE_RT_DENY_CONN      =8, /**< Connection has been denied */
319        TRACE_RT_PAUSE          =9, /**< Request server to suspend sending data
320                                     */
321        TRACE_RT_PAUSE_ACK      =10,/**< Server is paused message */
322        TRACE_RT_OPTION         =11,/**< Option request */
323        TRACE_RT_KEYCHANGE      =12,/**< Anonymisation key has changed */
324        TRACE_RT_DUCK_2_4       =13,/**< Dag 2.4 Duck */
325        TRACE_RT_DUCK_2_5       =14,/**< Dag 2.5 Duck */
326        TRACE_RT_LOSTCONN       =15,/**< Lost connection to server */
327        TRACE_RT_SERVERSTART    =16,/**< Reliable server has been restarted */
328        TRACE_RT_CLIENTDROP     =17,/**< Reliable client was lost */
329        TRACE_RT_METADATA       =18,/**< Packet contains server meta-data */
330
331        /** Not actually used - all DATA types begin from this value */
332        TRACE_RT_DATA_SIMPLE    = 1000,
333       
334        /** RT is encapsulating an ERF capture record */
335        TRACE_RT_DATA_ERF       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_ERF,
336        /** RT is encapsulating a WAG capture record */
337        TRACE_RT_DATA_WAG       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_WAG,
338        /** RT is encapsulating a Legacy ATM capture record */
339        TRACE_RT_DATA_LEGACY_ATM=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_ATM,
340        /** RT is encapsulating a Legacy POS capture record */
341        TRACE_RT_DATA_LEGACY_POS=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_POS,
342        /** RT is encapsulating a Legacy ETH capture record */
343        TRACE_RT_DATA_LEGACY_ETH=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LEGACY_ETH,
344        /** RT is encapsulating a Linux native capture record */
345        TRACE_RT_DATA_LINUX_NATIVE=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LINUX_NATIVE,
346        /** RT is encapsulating a BSD native capture record */
347        //TRACE_RT_DATA_BPF       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_BPF,
348        /** RT is encapsulating a TSH capture record */
349        TRACE_RT_DATA_TSH       =TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_TSH,
350        /** RT is encapsulating an ATM header capture record */
351        TRACE_RT_DATA_ATMHDR = TRACE_RT_DATA_SIMPLE + TRACE_FORMAT_ATMHDR,
352        /** RT is encapsulating a Legacy NZIX capture record */
353        TRACE_RT_DATA_LEGACY_NZIX=TRACE_RT_DATA_SIMPLE + TRACE_FORMAT_LEGACY_NZIX,
354        /** RT is encapsulating a Linux native PACKET_MMAP capture record */
355        TRACE_RT_DATA_LINUX_RING=TRACE_RT_DATA_SIMPLE+TRACE_FORMAT_LINUX_RING,
356
357        /** As PCAP does not store the linktype with the packet, we need to
358         * create a separate RT type for each supported DLT, starting from
359         * this value */
360        TRACE_RT_DATA_DLT               = 2000,
361        /** RT is encapsulating a PCAP capture record with a NULL linktype */
362        TRACE_RT_DLT_NULL               =TRACE_RT_DATA_DLT+TRACE_DLT_NULL,
363        /** RT is encapsulating a PCAP capture record with an Ethernet
364         * linktype */
365        TRACE_RT_DLT_EN10MB             =TRACE_RT_DATA_DLT+TRACE_DLT_EN10MB,
366        /** RT is encapsulating a PCAP capture record with an 802.11
367         * linktype */
368        TRACE_RT_DLT_IEEE802_11         =TRACE_RT_DATA_DLT+TRACE_DLT_IEEE802_11,
369        /** RT is encapsulating a PCAP capture record with a Linux SLL
370         * linktype */
371        TRACE_RT_DLT_LINUX_SLL          =TRACE_RT_DATA_DLT+TRACE_DLT_LINUX_SLL,
372        /** RT is encapsulating a PCAP capture record with a PFlog linktype */
373        TRACE_RT_DLT_PFLOG              =TRACE_RT_DATA_DLT+TRACE_DLT_PFLOG,
374        /** RT is encapsulating a PCAP capture record with an AAL5 linktype */
375        TRACE_RT_DLT_ATM_RFC1483        =TRACE_RT_DATA_DLT+TRACE_DLT_ATM_RFC1483,
376        /** Unused value marking the end of the valid range for PCAP RT
377         * encapsulation */
378        TRACE_RT_DATA_DLT_END           = 2999,
379        /** BPF does not store the linktype with the packet, so we need a
380         * separate RT type for each supported DLT. This value represents the
381         * starting point */
382        TRACE_RT_DATA_BPF               = 3000,
383
384        TRACE_RT_BPF_NULL               = TRACE_RT_DATA_BPF+TRACE_DLT_NULL,
385        TRACE_RT_BPF_EN10MB             = TRACE_RT_DATA_BPF+TRACE_DLT_EN10MB,
386        TRACE_RT_BPF_IEEE802_11         = TRACE_RT_DATA_BPF+TRACE_DLT_IEEE802_11,
387        TRACE_RT_BPF_PFLOG              =TRACE_RT_DATA_BPF+TRACE_DLT_PFLOG,
388        TRACE_RT_BPF_ATM_RFC1483        =TRACE_RT_DATA_BPF+TRACE_DLT_ATM_RFC1483,
389
390        TRACE_RT_DATA_BPF_END           = 3999,
391        /** Unused value marking the end of the valid range for all RT packet
392         * types */
393        TRACE_RT_LAST                   = 4000
394} libtrace_rt_types_t;
395
396/** IP Protocol values */
397typedef enum {
398        TRACE_IPPROTO_IP        = 0,    /**< IP pseudo protocol number */
399        TRACE_IPPROTO_ICMP      = 1,    /**< Internet Control Message protocol */
400        TRACE_IPPROTO_IGMP      = 2,    /**< Internet Group Management Protocol */
401        TRACE_IPPROTO_IPIP      = 4,    /**< IP encapsulated in IP */
402        TRACE_IPPROTO_TCP       = 6,    /**< Transmission Control Protocol */
403        TRACE_IPPROTO_UDP       = 17,   /**< User Datagram Protocol */
404        TRACE_IPPROTO_IPV6      = 41,   /**< IPv6 over IPv4 */
405        TRACE_IPPROTO_ROUTING   = 43,   /**< IPv6 Routing header */
406        TRACE_IPPROTO_FRAGMENT  = 44,   /**< IPv6 Fragmentation header */
407        TRACE_IPPROTO_RSVP      = 46,   /**< Resource Reservation Protocol */
408        TRACE_IPPROTO_GRE       = 47,   /**< General Routing Encapsulation */
409        TRACE_IPPROTO_ESP       = 50,   /**< Encapsulated Security Payload [RFC2406] */
410        TRACE_IPPROTO_AH        = 51,   /**< Authentication Header [RFC2402] */
411        TRACE_IPPROTO_ICMPV6    = 58,   /**< ICMPv6 */
412        TRACE_IPPROTO_NONE      = 59,   /**< IPv6 no next header */
413        TRACE_IPPROTO_DSTOPTS   = 60,   /**< IPv6 destination options */
414        TRACE_IPPROTO_OSPF      = 89,   /**< Open Shortest Path First routing protocol */
415        TRACE_IPPROTO_PIM       = 103,  /**< Protocol Independant Multicast */
416        TRACE_IPPROTO_SCTP      = 132   /**< Stream Control Transmission Protocol */
417} libtrace_ipproto_t;
418
419/** Ethertypes supported by Libtrace */
420typedef enum {
421        /* Numbers <=1500 are of course, LLC/SNAP */
422        TRACE_ETHERTYPE_LOOPBACK= 0x0060,       /**< Ethernet Loopback */
423        TRACE_ETHERTYPE_IP      = 0x0800,       /**< IPv4 */
424        TRACE_ETHERTYPE_ARP     = 0x0806,       /**< Address resolution protocol */
425        TRACE_ETHERTYPE_RARP    = 0x8035,       /**< Reverse ARP */
426        TRACE_ETHERTYPE_8021Q   = 0x8100,       /**< 802.1q VLAN Extended Header */
427        TRACE_ETHERTYPE_IPV6    = 0x86DD,       /**< IPv6 */
428        TRACE_ETHERTYPE_MPLS    = 0x8847,       /**< MPLS Unicast traffic */
429        TRACE_ETHERTYPE_MPLS_MC = 0x8848,       /**< MPLS Multicast traffic */
430        TRACE_ETHERTYPE_PPP_DISC= 0x8863,       /**< PPPoE Service Discovery */
431        TRACE_ETHERTYPE_PPP_SES = 0x8864        /**< PPPoE Session Messages */
432} libtrace_ethertype_t;
433
434/** The libtrace packet structure. Applications shouldn't be
435 * meddling around in here
436 */
437typedef struct libtrace_packet_t {
438        struct libtrace_t *trace;       /**< Pointer to the trace */
439        void *header;                   /**< Pointer to the framing header */
440        void *payload;                  /**< Pointer to the link layer */
441        void *buffer;                   /**< Allocated buffer */
442        libtrace_rt_types_t  type;      /**< RT protocol type for the packet */
443        buf_control_t buf_control;      /**< Describes memory ownership */
444        int capture_length;             /**< Cached capture length */
445        int wire_length;                /**< Cached wire length */
446        int payload_length;             /**< Cached payload length */
447        void *l2_header;                /**< Cached link header */
448        libtrace_linktype_t link_type;  /**< Cached link type */
449        uint32_t l2_remaining;          /**< Cached link remaining */
450        void *l3_header;                /**< Cached l3 header */
451        uint16_t l3_ethertype;          /**< Cached l3 ethertype */
452        uint32_t l3_remaining;          /**< Cached l3 remaining */
453        void *l4_header;                /**< Cached transport header */
454        uint8_t transport_proto;        /**< Cached transport protocol */
455        uint32_t l4_remaining;          /**< Cached transport remaining */
456} libtrace_packet_t;
457
458
459/** Trace directions.
460 * Note that these are the directions used by convention. More directions
461 * are possible, not just these 3, and that they may not conform to this
462 * convention.
463 */
464typedef enum {
465        TRACE_DIR_OUTGOING = 0,         /**< Packets originating "inside" */
466        TRACE_DIR_INCOMING = 1,         /**< Packets originating "outside" */
467        TRACE_DIR_OTHER    = 2          /**< Packets with an unknown direction, or one that's unknown */
468} libtrace_direction_t;
469
470/** Enumeration of Radiotap fields */
471typedef enum {
472    TRACE_RADIOTAP_TSFT = 0, /**< Timer synchronisation function, in microseconds (uint64) */
473    TRACE_RADIOTAP_FLAGS = 1, /**< Wireless flags (uint8) */
474    TRACE_RADIOTAP_RATE = 2, /**< Bitrate in units of 500kbps (uint8) */
475    TRACE_RADIOTAP_CHANNEL = 3, /**< Frequency in MHz (uint16) and channel flags (uint16) */
476    TRACE_RADIOTAP_FHSS = 4, /**< FHSS hop set (uint8) and hopping pattern (uint8) */
477    TRACE_RADIOTAP_DBM_ANTSIGNAL = 5, /**< Signal power in dBm (int8) */
478    TRACE_RADIOTAP_DBM_ANTNOISE = 6, /**< Noise power in dBm (int8) */
479    TRACE_RADIOTAP_LOCK_QUALITY = 7, /**< Barker Code lock quality (uint16) */
480    TRACE_RADIOTAP_TX_ATTENUATION = 8, /**< TX attenuation as unitless distance from max power (uint16) */
481    TRACE_RADIOTAP_DB_TX_ATTENUATION = 9, /**< TX attenutation as dB from max power (uint16) */
482    TRACE_RADIOTAP_DBM_TX_POWER = 10, /**< TX Power in dBm (int8) */
483    TRACE_RADIOTAP_ANTENNA = 11, /**< Antenna frame was rx'd or tx'd on (uint8) */
484    TRACE_RADIOTAP_DB_ANTSIGNAL = 12, /**< Signal power in dB from a fixed reference (uint8) */
485    TRACE_RADIOTAP_DB_ANTNOISE = 13, /**< Noise power in dB from a fixed reference (uint8) */
486    TRACE_RADIOTAP_RX_FLAGS = 14, /** Properties of received frame (uint16) */
487    TRACE_RADIOTAP_TX_FLAGS = 15, /** Properties of transmitted frame (uint16) */
488    TRACE_RADIOTAP_RTS_RETRIES = 16, /** Number of rts retries frame used (uint8) */
489    TRACE_RADIOTAP_DATA_RETRIES = 17, /** Number of unicast retries a transmitted frame used (uint8) */
490    TRACE_RADIOTAP_EXT = 31
491} libtrace_radiotap_field_t;
492
493
494/** @name Protocol structures
495 * These convenience structures provide portable versions of the headers
496 * for a variety of protocols.
497 * @{
498 */
499
500#ifdef WIN32
501#pragma pack(push)
502#pragma pack(1)
503#endif
504
505/** Generic IP header structure */
506typedef struct libtrace_ip
507{
508#if BYTE_ORDER == LITTLE_ENDIAN
509    LT_BITFIELD8 ip_hl:4;               /**< Header Length */
510    LT_BITFIELD8 ip_v:4;                /**< Version */
511#elif BYTE_ORDER == BIG_ENDIAN
512    LT_BITFIELD8 ip_v:4;                /**< Version */
513    LT_BITFIELD8 ip_hl:4;               /**< Header Length */
514#else
515#   error "Adjust your <bits/endian.h> defines"
516#endif
517    uint8_t  ip_tos;                    /**< Type of Service */
518    uint16_t ip_len;                    /**< Total Length */
519    int16_t  ip_id;                     /**< Identification */
520    uint16_t ip_off;                    /**< IP Fragment offset (and flags) */
521    uint8_t  ip_ttl;                    /**< Time to Live */
522    uint8_t  ip_p;                      /**< Protocol */
523    uint16_t ip_sum;                    /**< Checksum */
524    struct in_addr ip_src;              /**< Source Address */
525    struct in_addr ip_dst;              /**< Destination Address */
526} PACKED libtrace_ip_t;
527
528/** IPv6 header extension structure */
529typedef struct libtrace_ip6_ext
530{
531        uint8_t nxt;    /**< Next header */
532        uint8_t len;    /**< Length of the current header */
533} PACKED libtrace_ip6_ext_t;
534
535typedef struct libtrace_ip6_frag
536{
537        uint8_t nxt;    /**< Next header */
538        uint8_t res;    /**< Reserved */
539        uint16_t frag_off;      /**< Fragment Offset (includes M flag) */
540        uint32_t ident; /** Fragment identification */
541} PACKED libtrace_ip6_frag_t;
542
543/** Generic IPv6 header structure
544 *
545 * @note The flow label field also includes the Version and Traffic Class
546 * fields, because we haven't figured out a nice way to deal with fields
547 * crossing byte boundaries on both Big and Little Endian machines */
548typedef struct libtrace_ip6
549{
550    uint32_t flow;                      /**< Flow label */
551    uint16_t plen;                      /**< Payload length */
552    uint8_t nxt;                        /**< Next header */
553    uint8_t hlim;                       /**< Hop limit */
554    struct in6_addr ip_src;             /**< Source address */
555    struct in6_addr ip_dst;             /**< Destination address */
556} PACKED libtrace_ip6_t;
557
558/** Generic TCP header structure */
559typedef struct libtrace_tcp
560  {
561    uint16_t source;            /**< Source Port */
562    uint16_t dest;              /**< Destination port */
563    uint32_t seq;               /**< Sequence number */
564    uint32_t ack_seq;           /**< Acknowledgement Number */
565#  if BYTE_ORDER == LITTLE_ENDIAN
566    LT_BITFIELD8 ecn_ns:1;      /**< ECN Nonce Sum */
567    LT_BITFIELD8 res1:3;        /**< Reserved bits */
568    LT_BITFIELD8 doff:4;        /**< Data Offset */
569    LT_BITFIELD8 fin:1;         /**< FIN */
570    LT_BITFIELD8 syn:1;         /**< SYN flag */
571    LT_BITFIELD8 rst:1;         /**< RST flag */
572    LT_BITFIELD8 psh:1;         /**< PuSH flag */
573    LT_BITFIELD8 ack:1;         /**< ACK flag */
574    LT_BITFIELD8 urg:1;         /**< URG flag */
575    LT_BITFIELD8 ece:1;         /**< ECN Echo */
576    LT_BITFIELD8 cwr:1;         /**< ECN CWR */
577#  elif BYTE_ORDER == BIG_ENDIAN
578    LT_BITFIELD8 doff:4;        /**< Data offset */
579    LT_BITFIELD8 res1:3;        /**< Reserved bits */
580    LT_BITFIELD8 ecn_ns:1;      /**< ECN Nonce Sum */
581    LT_BITFIELD8 cwr:1;         /**< ECN CWR */
582    LT_BITFIELD8 ece:1;         /**< ECN Echo */
583    LT_BITFIELD8 urg:1;         /**< URG flag */
584    LT_BITFIELD8 ack:1;         /**< ACK flag */
585    LT_BITFIELD8 psh:1;         /**< PuSH flag */
586    LT_BITFIELD8 rst:1;         /**< RST flag */
587    LT_BITFIELD8 syn:1;         /**< SYN flag */
588    LT_BITFIELD8 fin:1;         /**< FIN flag */
589#  else
590#   error "Adjust your <bits/endian.h> defines"
591#  endif
592    uint16_t window;            /**< Window Size */
593    uint16_t check;             /**< Checksum */
594    uint16_t urg_ptr;           /**< Urgent Pointer */
595} PACKED libtrace_tcp_t;
596
597/** Generic UDP header structure */
598typedef struct libtrace_udp {
599  uint16_t      source;         /**< Source port */
600  uint16_t      dest;           /**< Destination port */
601  uint16_t      len;            /**< Length */
602  uint16_t      check;          /**< Checksum */
603} PACKED libtrace_udp_t;
604
605/** Generic ICMP header structure */
606typedef struct libtrace_icmp
607{
608  uint8_t type;         /**< Message Type */
609  uint8_t code;         /**< Type Sub-code */
610  uint16_t checksum;            /**< Checksum */
611  union
612  {
613    struct
614    {
615      uint16_t  id;             /**< ID of the Echo request */
616      uint16_t  sequence;       /**< Sequence number of the Echo request */
617    } echo;                     /**< Echo Datagram */
618    uint32_t    gateway;        /**< Gateway Address */
619    struct
620    {
621      uint16_t  unused;         /**< Unused */
622      uint16_t  mtu;            /**< Next-hop MTU */
623    } frag;                     /**< Path MTU Discovery */
624  } un;                         /**< Union for Payloads of Various ICMP Codes */
625} PACKED libtrace_icmp_t;
626
627typedef struct libtrace_icmp6 {
628  uint8_t type;         /**< Message Type */
629  uint8_t code;         /**< Type Sub-code */
630  uint16_t checksum;    /**< Checksum */
631
632  union {
633    struct {
634        uint8_t length;   /**< Length of original datagram content in 64 bit words */
635        uint8_t unused;   /**< Unused */       
636        uint8_t unused1;  /**< Unused */
637    } extend;   /**< Extensions added in RFC 4884 for Time Exceeded and Destination Unreachable Messages */
638
639    uint32_t mtu;       /**< MTU from Packet Too Big Message */
640    uint32_t pointer;   /**< Pointer from Parameter Problem Message */
641    struct {
642        uint16_t id;    /**< Echo Identifier */
643        uint16_t sequence; /**< Echo Sequence Number */
644    } echo; /**< Data required for Echo Request and Reply messages */
645  } un;
646} PACKED libtrace_icmp6_t;
647
648/** Generic LLC/SNAP header structure */
649typedef struct libtrace_llcsnap
650{
651/* LLC */
652  uint8_t dsap;                 /**< Destination Service Access Point */
653  uint8_t ssap;                 /**< Source Service Access Point */
654  uint8_t control;              /**< Control field */
655/* SNAP */
656  LT_BITFIELD32 oui:24;         /**< Organisationally Unique Identifier (scope)*/
657  uint16_t type;                /**< Protocol within OUI */
658} PACKED libtrace_llcsnap_t;
659
660/** 802.3 frame */
661typedef struct libtrace_ether
662{
663  uint8_t ether_dhost[6];       /**< Destination Ether Addr */
664  uint8_t ether_shost[6];       /**< Source Ether Addr */
665  uint16_t ether_type;          /**< Packet Type ID Field (next-header) */
666} PACKED libtrace_ether_t;
667
668/** 802.1Q frame */
669typedef struct libtrace_8021q
670{
671  LT_BITFIELD16 vlan_pri:3;      /**< VLAN User Priority */
672  LT_BITFIELD16 vlan_cfi:1;      /**< VLAN Format Indicator,
673                                   * 0 for ethernet, 1 for token ring */
674  LT_BITFIELD16 vlan_id:12;      /**< VLAN Id */
675  uint16_t vlan_ether_type;      /**< VLAN Sub-packet Type ID Field
676                                   * (next-header)*/
677} PACKED libtrace_8021q_t;
678
679/** ATM User Network Interface (UNI) Cell. */
680typedef struct libtrace_atm_cell
681{
682  LT_BITFIELD32 gfc:4;          /**< Generic Flow Control */
683  LT_BITFIELD32 vpi:8;          /**< Virtual Path Identifier */
684  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
685  LT_BITFIELD32 pt:3;           /**< Payload Type */
686  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
687  LT_BITFIELD32 hec:8;          /**< Header Error Control */
688} PACKED libtrace_atm_cell_t;
689
690/** ATM Network Node/Network Interface (NNI) Cell. */
691typedef struct libtrace_atm_nni_cell
692{
693  LT_BITFIELD32 vpi:12;         /**< Virtual Path Identifier */
694  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
695  LT_BITFIELD32 pt:3;           /**< Payload Type */
696  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
697  LT_BITFIELD32 hec:8;          /**< Header Error Control */
698} PACKED libtrace_atm_nni_cell_t;
699
700/** Captured UNI cell.
701 *
702 * Endace don't capture the HEC, presumably to keep alignment.  This
703 * version of the \ref libtrace_atm_cell is used when dealing with DAG
704 * captures of uni cells.
705 *
706 */
707typedef struct libtrace_atm_capture_cell
708{
709  LT_BITFIELD32 gfc:4;          /**< Generic Flow Control */
710  LT_BITFIELD32 vpi:8;          /**< Virtual Path Identifier */
711  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
712  LT_BITFIELD32 pt:3;           /**< Payload Type */
713  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
714} PACKED libtrace_atm_capture_cell_t;
715
716/** Captured NNI cell.
717 *
718 * Endace don't capture the HEC, presumably to keep alignment.  This
719 * version of the \ref libtrace_atm_nni_cell is used when dealing with DAG
720 * captures of nni cells.
721 *
722 */
723typedef struct libtrace_atm_nni_capture_cell
724{
725  LT_BITFIELD32 vpi:12;         /**< Virtual Path Identifier */
726  LT_BITFIELD32 vci:16;         /**< Virtual Channel Identifier */
727  LT_BITFIELD32 pt:3;           /**< Payload Type */
728  LT_BITFIELD32 clp:1;          /**< Cell Loss Priority */
729  LT_BITFIELD32 hec:8;          /**< Header Error Control */
730} PACKED libtrace_atm_nni_capture_cell_t;
731
732/** PPP header */
733typedef struct libtrace_ppp
734{
735 /* I can't figure out where the hell these two variables come from. They're
736  * definitely not in RFC 1661 which defines PPP. Probably some weird thing
737  * relating to the lack of distinction between PPP, HDLC and CHDLC */
738       
739/* uint8_t address; */          /**< PPP Address (0xFF - All stations) */
740/* uint8_t header;  */          /**< PPP Control (0x03 - Unnumbered info) */
741 uint16_t protocol;             /**< PPP Protocol (htons(0x0021) - IPv4 */
742} PACKED libtrace_ppp_t;
743
744/** PPPoE header */
745typedef struct libtrace_pppoe
746{
747 LT_BITFIELD8 version:4;        /**< Protocol version number */
748 LT_BITFIELD8 type:4;           /**< PPPoE Type */
749 uint8_t code;                  /**< PPPoE Code */
750 uint16_t session_id;           /**< Session Identifier */
751 uint16_t length;               /**< Total Length of the PPP packet */
752} PACKED libtrace_pppoe_t;
753
754/** 802.11 header */
755typedef struct libtrace_80211_t {
756#if BYTE_ORDER == LITTLE_ENDIAN
757        LT_BITFIELD32      protocol:2;  /**< Protocol Version */
758        LT_BITFIELD32      type:2;      /**< Frame Type */
759        LT_BITFIELD32      subtype:4;   /**< Frame Subtype */
760#else
761        LT_BITFIELD32      subtype:4;   /**< Frame Subtype */
762        LT_BITFIELD32      type:2;      /**< Frame Type */
763        LT_BITFIELD32      protocol:2;  /**< Protocol Version */
764#endif
765
766#if BYTE_ORDER == LITTLE_ENDIAN
767        LT_BITFIELD32      to_ds:1;     /**< Packet to Distribution Service */
768        LT_BITFIELD32      from_ds:1;   /**< Packet from Distribution Service */
769        LT_BITFIELD32      more_frag:1; /**< Packet has more fragments */
770        LT_BITFIELD32      retry:1;     /**< Packet is a retry */
771        LT_BITFIELD32      power:1;     /**< Power Management mode */
772        LT_BITFIELD32      more_data:1; /**< More data is buffered at station */
773        LT_BITFIELD32      wep:1;       /**< WEP encryption indicator */
774        LT_BITFIELD32      order:1;     /**< Strictly-Ordered class indicator */
775#else
776        LT_BITFIELD32      order:1;     /**< Strictly-Ordered class indicator */
777        LT_BITFIELD32      wep:1;       /**< WEP encryption indicator */
778        LT_BITFIELD32      more_data:1; /**< More data is buffered at station */
779        LT_BITFIELD32      power:1;     /**< Power Management mode */
780        LT_BITFIELD32      retry:1;     /**< Packet is a retry */
781        LT_BITFIELD32      more_frag:1; /**< Packet has more fragments */
782        LT_BITFIELD32      from_ds:1;   /**< Packet from Distribution Service */
783        LT_BITFIELD32      to_ds:1;     /**< Packet to Distribution Service */
784#endif
785       
786        uint16_t     duration;  /**< Duration value for NAV calculation */
787        uint8_t      mac1[6];   /**< MAC Address 1 */
788        uint8_t      mac2[6];   /**< MAC Address 2 */
789        uint8_t      mac3[6];   /**< MAC Address 3 */
790        uint16_t     SeqCtl;    /**< Sequence Control */       
791        uint8_t      mac4[6];   /**< MAC Address 4 */
792} PACKED libtrace_80211_t;
793
794/** The Radiotap header pre-amble
795 *
796 * All Radiotap headers start with this pre-amble, followed by the fields
797 * specified in the it_present bitmask. If bit 31 of it_present is set, then
798 * another bitmask follows.
799 * @note All of the radiotap data fields are in little-endian byte-order.
800 */
801typedef struct libtrace_radiotap_t {
802    uint8_t     it_version; /**< Radiotap version */
803    uint8_t     it_pad; /**< Padding for natural alignment */
804    uint16_t    it_len; /**< Length in bytes of the entire Radiotap header */
805    uint32_t    it_present; /**< Which Radiotap fields are present */
806} PACKED libtrace_radiotap_t;
807
808/** OSPF header */
809typedef struct libtrace_ospf_v2_t
810{
811        uint8_t ospf_v;         /**< OSPF Version, should be 2 */
812        uint8_t type;           /**< OSPF Packet Type */
813        uint16_t len;           /**< Packet length, including OSPF header */
814        struct in_addr router;  /**< Router ID of the packet source */
815        struct in_addr area;    /**< Area the packet belongs to */
816        uint16_t sum;           /**< Checksum */
817        uint16_t au_type;       /**< Authentication procedure */
818        uint16_t zero;          /**< Always zero */
819        uint8_t au_key_id;      /**< Authentication Key ID */
820        uint8_t au_data_len;    /**< Authentication Data Length */
821        uint32_t au_seq_num;    /**< Cryptographic Sequence Number */
822} PACKED libtrace_ospf_v2_t;
823
824/** Options Field present in some OSPFv2 packets */
825typedef struct libtrace_ospf_options_t {
826#if BYTE_ORDER == LITTLE_ENDIAN
827        LT_BITFIELD8 unused1:1;
828        LT_BITFIELD8 e_bit:1;
829        LT_BITFIELD8 mc_bit:1;
830        LT_BITFIELD8 np_bit:1;
831        LT_BITFIELD8 ea_bit:1;
832        LT_BITFIELD8 dc_bit:1;
833        LT_BITFIELD8 unused2:2;
834#elif BYTE_ORDER == BIG_ENDIAN
835        LT_BITFIELD8 unused2:2;
836        LT_BITFIELD8 dc_bit:1;
837        LT_BITFIELD8 ea_bit:1;
838        LT_BITFIELD8 np_bit:1;
839        LT_BITFIELD8 mc_bit:1;
840        LT_BITFIELD8 e_bit:1;
841        LT_BITFIELD8 unused1:1;
842#endif
843} PACKED libtrace_ospf_options_t;
844
845/** LSA Header for OSPFv2 */
846typedef struct libtrace_ospf_lsa_v2_t
847{
848        uint16_t age;           /**< Time in seconds since LSA originated */
849        libtrace_ospf_options_t lsa_options;    /**< Options */
850        uint8_t lsa_type;       /**< LSA type */
851        struct in_addr ls_id;   /**< Link State ID */
852        struct in_addr adv_router; /**< Router that originated this LSA */
853        uint32_t seq;           /**< LS sequence number */
854        uint16_t checksum;      /**< Checksum */
855        uint16_t length;        /**< Length of the LSA including LSA header */
856} PACKED libtrace_ospf_lsa_v2_t;
857
858/** OSPFv2 Hello Packet */
859typedef struct libtrace_ospf_hello_v2_t
860{
861        struct in_addr mask;    /**< Network mask for this interface */
862        uint16_t interval;      /**< Interval between Hello packets (secs) */
863        libtrace_ospf_options_t hello_options;  /**< Options */
864        uint8_t priority;       /**< Router Priority */
865        uint32_t deadint;       /**< Interval before declaring a router down */
866        struct in_addr designated;      /**< Designated router for the network */
867        struct in_addr backup;  /**< Backup designated router */
868
869        /** Neighbors follow from here, but there can be anywhere from 1 to N
870         * neighbors so I can't include that here */
871} PACKED libtrace_ospf_hello_v2_t;
872
873/** OSPFv2 Database Description packet */
874typedef struct libtrace_ospf_db_desc_v2_t
875{
876        uint16_t mtu;           /**< Interface MTU */
877        libtrace_ospf_options_t db_desc_options;        /**< Options */
878#if BYTE_ORDER == LITTLE_ENDIAN
879        LT_BITFIELD8 db_desc_ms:1;      /**< If set, this router is the master */
880        LT_BITFIELD8 db_desc_m:1;       /**< If set, more packets to follow */
881        LT_BITFIELD8 db_desc_i:1;       /**< If set, this is the first packet in sequence */
882        LT_BITFIELD8 zero:5;
883#elif BYTE_ORDER == BIG_ENDIAN
884        LT_BITFIELD8 zero:5;
885        LT_BITFIELD8 db_desc_i:1;       /**< If set, this is the first packet in sequence */
886        LT_BITFIELD8 db_desc_m:1;       /**< If set, more packets to follow */
887        LT_BITFIELD8 db_desc_ms:1;      /**< If set, this router is the master */
888#endif
889        uint32_t seq;           /**< Sequence number for DD packets */
890} PACKED libtrace_ospf_db_desc_v2_t;
891
892/** OSPF Link State Request Packet */
893typedef struct libtrace_ospf_ls_req_t
894{
895        uint32_t ls_type;       /**< Link State Type */
896        uint32_t ls_id;         /**< Link State Id */
897        uint32_t advertising_router;    /**< Advertising Router */
898} PACKED libtrace_ospf_ls_req_t;
899
900/** OSPF Link State Update Packet */
901typedef struct libtrace_ospf_ls_update_t
902{
903        uint32_t ls_num_adv;    /**< Number of LSAs in this packet */
904
905        /* Followed by LSAs, use API functions to access these */
906} PACKED libtrace_ospf_ls_update_t;
907
908/** OSPFv2 AS External LSA Body */
909typedef struct libtrace_ospf_as_external_lsa_t
910{
911        struct in_addr netmask; /**< Netmask for the destination */
912#if BYTE_ORDER == LITTLE_ENDIAN
913        LT_BITFIELD8 tos:7;
914        LT_BITFIELD8 e:1;       /**< If set, metric is Type 2. Else, Type 1 */
915#elif BYTE_ORDER == BIG_ENDIAN
916        LT_BITFIELD8 e:1;       /**< If set, metric is Type 2. Else, Type 1 */
917        LT_BITFIELD8 tos:7;
918#endif
919        uint8_t metric_a;       /**< Byte 1 of the Metric field */
920        uint8_t metric_b;       /**< Byte 2 of the Metric field */
921        uint8_t metric_c;       /**< Byte 3 of the Metric field */
922        struct in_addr forwarding;      /**< Forwarding address */
923        uint32_t external_tag;          /**< External Route Tag */
924} PACKED libtrace_ospf_as_external_lsa_v2_t;
925
926/** OSPFv2 Summary LSA Body */
927typedef struct libtrace_ospf_summary_lsa
928{
929        struct in_addr netmask; /**< Netmask for the destination */
930        uint8_t zero;           /**< Always zero */
931        uint8_t metric_a;       /**< Byte 1 of the Metric field */
932        uint8_t metric_b;       /**< Byte 2 of the Metric field */
933        uint8_t metric_c;       /**< Byte 3 of the Metric field */
934       
935} PACKED libtrace_ospf_summary_lsa_v2_t;
936
937/** OSPFv2 Network LSA Body */
938typedef struct libtrace_ospf_network_lsa_t
939{
940        struct in_addr netmask; /**< Netmask for the network */
941        /* Followed by IDs of attached routers */
942} PACKED libtrace_ospf_network_lsa_v2_t;
943
944/** OSPFv2 Router Link structure */
945typedef struct libtrace_ospf_link_t
946{
947        struct in_addr link_id;         /**< Object that link connects to */
948        struct in_addr link_data;       /**< Link Data field */
949        uint8_t type;                   /**< Link Type */
950        uint8_t num_tos;                /**< Number of TOS metrics */
951        uint16_t tos_metric;            /**< Cost of router link */
952} PACKED libtrace_ospf_link_v2_t;
953
954/** OSPFv2 Router LSA */
955typedef struct libtrace_ospf_router_lsa_t
956{
957#if BYTE_ORDER == LITTLE_ENDIAN
958        LT_BITFIELD8 b:1;       /**< Area Border Router Flag */
959        LT_BITFIELD8 e:1;       /**< External Router Flag */
960        LT_BITFIELD8 v:1;       /**< Virtual Endpoint Flag */
961        LT_BITFIELD8 zero:5;
962#elif BYTE_ORDER == BIG_ENDIAN
963        LT_BITFIELD8 zero:5;
964        LT_BITFIELD8 v:1;       /**< Virtual Endpoint Flag */
965        LT_BITFIELD8 e:1;       /**< External Router Flag */
966        LT_BITFIELD8 b:1;       /**< Area Border Router Flag */
967#endif
968        uint8_t zero2;          /**< Always zero */
969        uint16_t num_links;     /**< Number of links in LSA */
970} PACKED libtrace_ospf_router_lsa_v2_t;
971
972typedef enum {
973        TRACE_OSPF_HELLO = 1,           /**< OSPF Hello */
974        TRACE_OSPF_DATADESC = 2,        /**< OSPF Database Description */
975        TRACE_OSPF_LSREQ = 3,           /**< OSPF Link State Request */
976        TRACE_OSPF_LSUPDATE = 4,        /**< OSPF Link State Update */
977        TRACE_OSPF_LSACK = 5            /**< OSPF Link State Acknowledgement */
978} libtrace_ospf_types_t;
979
980typedef enum {
981        TRACE_OSPF_LS_ROUTER = 1,       /**< OSPF Router LSA */
982        TRACE_OSPF_LS_NETWORK = 2,      /**< OSPF Network LSA */
983        TRACE_OSPF_LS_SUMMARY = 3,      /**< OSPF Summary LSA */
984        TRACE_OSPF_LS_ASBR_SUMMARY = 4, /**< OSPF Summary LSA (ASBR) */
985        TRACE_OSPF_LS_EXTERNAL = 5      /**< OSPF AS External LSA */
986} libtrace_ospf_ls_types_t;
987
988/** A local definition of an SLL header */
989typedef struct libtrace_sll_header_t {
990        uint16_t pkttype;               /**< Packet type */
991        uint16_t hatype;                /**< Link-layer address type */
992        uint16_t halen;                 /**< Link-layer address length */
993        unsigned char addr[8];          /**< Link-layer address */
994        uint16_t protocol;              /**< Protocol */
995} libtrace_sll_header_t;
996
997
998/* SLL packet types */
999
1000/** Packet was addressed for the local host */
1001#define TRACE_SLL_HOST          0
1002/** Packet was addressed for a broadcast address */
1003#define TRACE_SLL_BROADCAST     1
1004/** Packet was addressed for a multicast address */
1005#define TRACE_SLL_MULTICAST     2
1006/** Packet was addressed for another host but was captured by a promiscuous
1007 * device */
1008#define TRACE_SLL_OTHERHOST     3
1009/** Packet originated from the local host */
1010#define TRACE_SLL_OUTGOING      4
1011
1012
1013#ifdef WIN32
1014#pragma pack(pop)
1015#endif
1016
1017
1018/*@}*/
1019
1020/** Prints help information for libtrace
1021 *
1022 * Function prints out some basic help information regarding libtrace,
1023 * and then prints out the help() function registered with each input module
1024 */
1025DLLEXPORT void trace_help(void);
1026
1027/** Causes a libtrace reader to stop blocking whilst waiting on new packets
1028 * and immediately return EOF.
1029 *
1030 * This function is useful if you are handling signals within your libtrace
1031 * program. If a live source is not receiving any packets (or they are being
1032 * filtered), a call to trace_read_packet will result in an infinite loop as
1033 * it will block until a packet is received. Normally, a SIGINT would cause the
1034 * program to end and thus break the loop, but if you are handling the signal
1035 * yourself then that signal will never reach libtrace.
1036 *
1037 * Instead this function sets a global variable within libtrace that will
1038 * cause a blocking live capture to break on the next internal timeout,
1039 * allowing control to be returned to the user and their own signal handling
1040 * to kick in.
1041 */
1042DLLEXPORT void trace_interrupt(void);
1043
1044/** @name Trace management
1045 * These members deal with creating, configuring, starting, pausing and
1046 * cleaning up a trace object
1047 *@{
1048 */
1049
1050/** Takes a uri and splits it into a format and uridata component.
1051 * @param uri           The uri to be parsed
1052 * @param [out] format  A pointer that will be updated to point to an allocated
1053 *                      string holding the format component of the URI
1054 * @return NULL if an error occured, otherwise return a pointer to the uridata
1055 * component
1056 *
1057 * @note The format component is strdup'd by this function, so be sure to free
1058 * it when you are done with the split URI. Similarly, do not pass a pointer
1059 * to an allocated string into this function as the 'format' parameter, as
1060 * that memory will be leaked and replaced with the strdup'd format.
1061 */
1062DLLEXPORT const char *trace_parse_uri(const char *uri, char **format);
1063
1064/** Create an input trace from a URI
1065 *
1066 * @param uri A valid libtrace URI to be opened
1067 * @return An opaque pointer to a libtrace_t
1068 *
1069 * Some valid URI's are:
1070 *  - erf:/path/to/erf/file
1071 *  - erf:-  (stdin)
1072 *  - dag:/dev/dagcard                 
1073 *  - pcapint:pcapinterface                (eg: pcap:eth0)
1074 *  - pcap:/path/to/pcap/file
1075 *  - pcap:-
1076 *  - rt:hostname
1077 *  - rt:hostname:port
1078 *
1079 *  If an error occured when attempting to open the trace file, a
1080 *  trace is still returned so trace_is_err() should be called to find out
1081 *  if an error occured. The trace is created in the configuration state, you
1082 *  must call trace_start before attempting to read packets from the trace.
1083 */
1084DLLEXPORT libtrace_t *trace_create(const char *uri);
1085
1086/** Creates a "dummy" trace file that has only the format type set.
1087 *
1088 * @param uri A valid (but fake) URI indicating the format of the dummy trace that is to be created.
1089 * @return An opaque pointer to a (sparsely initialised) libtrace_t
1090 *
1091 * Only the format portion of the uri parameter matters - the 'file' being
1092 * opened does not have to exist.
1093 *
1094 * @note IMPORTANT: Do not attempt to call trace_read_packet or other such
1095 * functions with the dummy trace. Its intended purpose is to provide access
1096 * to the format functions where the original trace may no longer exist or is
1097 * not the correct format, e.g. reading ERF packets from an RT input.
1098 */
1099DLLEXPORT libtrace_t *trace_create_dead(const char *uri);
1100
1101/** Creates a trace output file from a URI.
1102 *
1103 * @param uri The uri string describing the output format and destination
1104 * @return An opaque pointer to a libtrace_output_t
1105 *
1106 * Valid URIs include:
1107 *  - erf:/path/to/erf/file
1108 *  - pcap:/path/to/pcap/file
1109 *
1110 *  If an error occured when attempting to open the output trace, a trace is
1111 *  still returned but trace_errno will be set. Use trace_is_err_out() and
1112 *  trace_perror_output() to get more information.
1113 */
1114DLLEXPORT libtrace_out_t *trace_create_output(const char *uri);
1115
1116/** Start an input trace
1117 * @param libtrace      The trace to start
1118 * @return 0 on success, -1 on failure
1119 *
1120 * This does the actual work of starting the input trace and applying
1121 * all the config options.  This may fail, returning -1. The libtrace error
1122 * handling functions can be used to get more information about what
1123 * specifically went wrong.
1124 */
1125DLLEXPORT int trace_start(libtrace_t *libtrace);
1126
1127/** Pauses an input trace
1128 * @param libtrace      The trace to pause
1129 * @return 0 on success, -1 on failure
1130 *
1131 * This stops an input trace that is in progress and returns you to the
1132 * configuration state.  Any packets that arrive on a live capture after
1133 * trace_pause() has been called will be discarded.  To resume the trace, call
1134 * trace_start().
1135 */
1136DLLEXPORT int trace_pause(libtrace_t *libtrace);
1137
1138/** Start an output trace
1139 * @param libtrace      The trace to start
1140 * @return 0 on success, -1 on failure
1141 *
1142 * This does the actual work with starting a trace capable of writing packets. 
1143 * This generally creates the output file.
1144 */
1145DLLEXPORT int trace_start_output(libtrace_out_t *libtrace);
1146
1147/** Valid configuration options for input traces */
1148typedef enum {
1149        /** Maximum number of bytes to be captured for any given packet */
1150        TRACE_OPTION_SNAPLEN,   
1151
1152        /** If enabled, places a live capture interface into promiscuous mode */
1153        TRACE_OPTION_PROMISC,   
1154
1155        /** Apply this filter to all packets read from this trace */
1156        TRACE_OPTION_FILTER,   
1157
1158        /** Defines the frequency of meta-data reporting, e.g. DUCK packets */
1159        TRACE_OPTION_META_FREQ,
1160
1161        /** If enabled, the libtrace event API will ignore time gaps between
1162         * packets when reading from a trace file */
1163        TRACE_OPTION_EVENT_REALTIME
1164} trace_option_t;
1165
1166/** Sets an input config option
1167 * @param libtrace      The trace object to apply the option to
1168 * @param option        The option to set
1169 * @param value         The value to set the option to
1170 * @return -1 if option configuration failed, 0 otherwise
1171 * This should be called after trace_create, and before trace_start
1172 */
1173DLLEXPORT int trace_config(libtrace_t *libtrace,
1174                trace_option_t option,
1175                void *value);
1176
1177/** Valid compression types
1178 * Note, this must be kept in sync with WANDIO_COMPRESS_* numbers in wandio.h
1179 */
1180typedef enum {
1181        TRACE_OPTION_COMPRESSTYPE_NONE = 0, /**< No compression */
1182        TRACE_OPTION_COMPRESSTYPE_ZLIB = 1, /**< GZip Compression */
1183        TRACE_OPTION_COMPRESSTYPE_BZ2  = 2, /**< BZip2 Compression */
1184        TRACE_OPTION_COMPRESSTYPE_LZO  = 3  /**< LZO Compression */
1185} trace_option_compresstype_t;
1186
1187/** Valid configuration options for output traces */
1188typedef enum {
1189        /** File flags to use when opening an output file, e.g. O_APPEND */
1190        TRACE_OPTION_OUTPUT_FILEFLAGS,
1191        /** Compression level: 0 = no compression, 1 = faster compression,
1192         * 9 = better compression */
1193        TRACE_OPTION_OUTPUT_COMPRESS,
1194        /** Compression type, see trace_option_compresstype_t */
1195        TRACE_OPTION_OUTPUT_COMPRESSTYPE
1196} trace_option_output_t;
1197
1198/** Sets an output config option
1199 *
1200 * @param libtrace      The output trace object to apply the option to
1201 * @param option        The option to set
1202 * @param value         The value to set the option to
1203 * @return -1 if option configuration failed, 0 otherwise
1204 * This should be called after trace_create_output, and before
1205 * trace_start_output
1206 */
1207DLLEXPORT int trace_config_output(libtrace_out_t *libtrace,
1208                trace_option_output_t option,
1209                void *value
1210                );
1211
1212/** Close an input trace, freeing up any resources it may have been using
1213 *
1214 * @param trace         The input trace to be destroyed
1215 *
1216 */
1217DLLEXPORT void trace_destroy(libtrace_t *trace);
1218
1219/** Close a dummy trace file, freeing up any resources it may have been using
1220 * @param trace         The dummy trace to be destroyed
1221 */
1222DLLEXPORT void trace_destroy_dead(libtrace_t *trace);
1223
1224/** Close an output trace, freeing up any resources it may have been using
1225 * @param trace         The output trace to be destroyed
1226 */
1227DLLEXPORT void trace_destroy_output(libtrace_out_t *trace);
1228
1229/** Check (and clear) the current error state of an input trace
1230 * @param trace         The input trace to check the error state on
1231 * @return The current error status and message
1232 *
1233 * This reads and returns the current error state and sets the current error
1234 * to "no error".
1235 */
1236DLLEXPORT libtrace_err_t trace_get_err(libtrace_t *trace);
1237
1238/** Indicate if there has been an error on an input trace
1239 * @param trace         The input trace to check the error state on
1240 * @return true if an error has occurred, false otherwise
1241 *
1242 * @note This does not clear the error status, and only returns true or false.
1243 */
1244DLLEXPORT bool trace_is_err(libtrace_t *trace);
1245
1246/** Outputs the error message for an input trace to stderr and clear the error
1247 * status.
1248 * @param trace         The input trace with the error to output
1249 * @param msg           The message to prepend to the error
1250 *
1251 * This function does clear the error status.
1252 */
1253DLLEXPORT void trace_perror(libtrace_t *trace, const char *msg,...) PRINTF(2,3);
1254
1255/** Checks (and clears) the current error state for an output trace
1256 * @param trace         The output trace to check the error state on
1257 * @return The current error status and message
1258 *
1259 * This reads and returns the current error state and sets the current error
1260 * to "no error".
1261 */
1262DLLEXPORT libtrace_err_t trace_get_err_output(libtrace_out_t *trace);
1263
1264/** Indicates if there is an error on an output trace
1265 * @param trace         The output trace to check the error state on
1266 * @return true if an error has occurred, false otherwise.
1267 *
1268 * This does not clear the error status, and only returns true or false.
1269 */
1270DLLEXPORT bool trace_is_err_output(libtrace_out_t *trace);
1271
1272/** Outputs the error message for an output trace to stderr and clear the error
1273 * status.
1274 * @param trace         The output trace with the error to output
1275 * @param msg           The message to prepend to the error
1276 * This function does clear the error status.
1277 */
1278DLLEXPORT void trace_perror_output(libtrace_out_t *trace, const char *msg,...)
1279        PRINTF(2,3);
1280
1281/** Returns the number of packets observed on an input trace.
1282 * Includes the number of packets counted as early as possible, before
1283 * filtering, and includes dropped packets.
1284 *
1285 * @param trace         The input trace to examine
1286 * @returns The number of packets seen at the capture point before filtering.
1287 *
1288 * If the number is not known, this function will return UINT64_MAX
1289 */
1290DLLEXPORT
1291uint64_t trace_get_received_packets(libtrace_t *trace);
1292
1293/** Returns the number of packets that were captured, but discarded for not
1294 * matching a provided filter.
1295 *
1296 * @param trace         The input trace to examine
1297 * @returns The number of packets that were successfully captured, but filtered
1298 *
1299 * If the number is not known, this function will return UINT64_MAX
1300 */
1301DLLEXPORT
1302uint64_t trace_get_filtered_packets(libtrace_t *trace);
1303
1304/** Returns the number of packets that have been dropped on an input trace due
1305 * to lack of buffer space on the capturing device.
1306 *
1307 * @param trace         The input trace to examine
1308 * @returns The number of packets captured, but dropped due to buffer overruns
1309 *
1310 * If the number is not known, this function will return UINT64_MAX
1311 */
1312DLLEXPORT
1313uint64_t trace_get_dropped_packets(libtrace_t *trace);
1314
1315/** Returns the number of packets that have been read from the input trace using
1316 * trace_read_packet().
1317 *
1318 * @param trace         The input trace to examine
1319 * @returns The number of packets that have been read by the libtrace user.
1320 *
1321 * If the number is not known, this function will return UINT64_MAX
1322 */
1323DLLEXPORT
1324uint64_t trace_get_accepted_packets(libtrace_t *trace);
1325
1326
1327/*@}*/
1328
1329/** @name Reading / Writing packets
1330 * These members deal with creating, reading and writing packets
1331 *
1332 * @{
1333 */
1334
1335/** Create a new packet object
1336 *
1337 * @return A pointer to an initialised libtrace_packet_t object
1338 */
1339DLLEXPORT libtrace_packet_t *trace_create_packet(void);
1340
1341/** Copy a packet object
1342 * @param packet        The source packet to copy
1343 * @return A new packet which has the same content as the source packet
1344 *
1345 * @note This always involves a copy, which can be slow.  Use of this
1346 * function should be avoided where possible.
1347 *
1348 * @par The reason you would want to use this function is that a zerocopied
1349 * packet from a device will be stored using memory owned by the device which
1350 * may be a limited resource. Copying the packet will ensure that the packet
1351 * is now stored in memory owned and managed by libtrace.
1352 */
1353DLLEXPORT libtrace_packet_t *trace_copy_packet(const libtrace_packet_t *packet);
1354
1355/** Destroy a packet object
1356 * @param packet        The packet to be destroyed
1357 *
1358 */
1359DLLEXPORT void trace_destroy_packet(libtrace_packet_t *packet);
1360
1361
1362/** Read the next packet from an input trace
1363 *
1364 * @param trace         The libtrace opaque pointer for the input trace
1365 * @param packet        The packet opaque pointer
1366 * @return 0 on EOF, negative value on error, number of bytes read when successful.
1367 *
1368 * @note The number of bytes read is usually (but not always) the same as
1369 * trace_get_framing_length()+trace_get_capture_length() depending on the
1370 * trace format.
1371 *
1372 * @note The trace must have been started with trace_start before calling
1373 * this function
1374 *
1375 * @note When reading from a live capture, this function will block until a
1376 * packet is observed on the capture interface. The libtrace event API
1377 * (e.g. trace_event()) should be used if non-blocking operation is required.
1378 */
1379DLLEXPORT int trace_read_packet(libtrace_t *trace, libtrace_packet_t *packet);
1380
1381/** Event types
1382 * see \ref libtrace_eventobj_t and \ref trace_event
1383 */
1384typedef enum {
1385        TRACE_EVENT_IOWAIT,     /**< Wait on the given file descriptor */
1386        TRACE_EVENT_SLEEP,      /**< Sleep for the given amount of time */
1387        TRACE_EVENT_PACKET,     /**< Packet has been read from input trace */
1388        TRACE_EVENT_TERMINATE   /**< End of input trace */
1389} libtrace_event_t;
1390
1391/** Structure returned by libtrace_event explaining what the current event is */
1392typedef struct libtrace_eventobj_t {
1393        libtrace_event_t type; /**< Event type (iowait,sleep,packet) */
1394       
1395        /** If the event is IOWAIT, the file descriptor to wait on */
1396        int fd;               
1397        /** If the event is SLEEP, the amount of time to sleep for in seconds */
1398        double seconds;       
1399        /** If the event is PACKET, the value returned by trace_read_packet() */
1400        int size;
1401} libtrace_eventobj_t;
1402
1403/** Processes the next libtrace event from an input trace.
1404 * @param trace The libtrace opaque pointer for the input trace
1405 * @param packet The libtrace_packet opaque pointer to use for reading packets
1406 * @return A libtrace_event struct containing the event type and details of the event.
1407 *
1408 * Type can be:
1409 *  TRACE_EVENT_IOWAIT  Waiting on I/O on a file descriptor
1410 *  TRACE_EVENT_SLEEP   Wait a specified amount of time for the next event
1411 *  TRACE_EVENT_PACKET  Packet was read from the trace
1412 *  TRACE_EVENT_TERMINATE Trace terminated (perhaps with an error condition)
1413 */
1414DLLEXPORT libtrace_eventobj_t trace_event(libtrace_t *trace,
1415                libtrace_packet_t *packet);
1416
1417
1418/** Write one packet out to the output trace
1419 *
1420 * @param trace         The libtrace_out opaque pointer for the output trace
1421 * @param packet        The packet opaque pointer of the packet to be written
1422 * @return The number of bytes written out, if zero or negative then an error has occured.
1423 */
1424DLLEXPORT int trace_write_packet(libtrace_out_t *trace, libtrace_packet_t *packet);
1425
1426/** Gets the capture format for a given packet.
1427 * @param packet        The packet to get the capture format for.
1428 * @return The capture format of the packet
1429 *
1430 * @note Due to ability to convert packets between formats relatively easily
1431 * in Libtrace, the format of the packet right now may not be the format that
1432 * the packet was originally captured with.
1433 */
1434DLLEXPORT
1435enum base_format_t trace_get_format(struct libtrace_packet_t *packet);
1436
1437/** Construct a libtrace packet from a buffer containing the packet payload.
1438 * @param[in,out] packet        Libtrace Packet object to update with the new
1439 *                              data.
1440 * @param linktype              The linktype of the packet data.
1441 * @param[in] data              The packet data (including linklayer).
1442 * @param len                   Length of packet data provided in the buffer.
1443 *
1444 * @note The constructed packet will be in the PCAP format.
1445 *
1446 * @note To be useful, the provided buffer must start with the layer 2 header
1447 * (or a metadata header, if desired).
1448 */
1449DLLEXPORT
1450void trace_construct_packet(libtrace_packet_t *packet,
1451                libtrace_linktype_t linktype, const void *data, uint16_t len);
1452
1453/*@}*/
1454
1455/** @name Protocol decodes
1456 * These functions locate and return a pointer to various headers inside a
1457 * packet
1458 *
1459 * A packet is divided up into several "layers.":
1460 *
1461 * @li Framing header -- This is the header provided by the capture format
1462 * itself rather than anything that was sent over the network. This provides
1463 * basic details about the packet record including capture lengths, wire
1464 * lengths, timestamps, direction information and any other metadata that is
1465 * part of the capture format. 
1466 *
1467 * @li Metadata header (optional) -- A header containing metadata about a
1468 * packet that was captured, but the metadata was not transmitted over the
1469 * wire.  Some examples include RadioTap and Linux_sll headers.  This can be
1470 * retrieved by trace_get_packet_meta(), or skipped using
1471 * trace_get_payload_from_meta(). There may be multiple "metadata" headers on
1472 * a packet.
1473 *
1474 * @li Layer 2/Link layer/Datalink header -- This can be retrieved by
1475 * trace_get_layer2(), or skipped using trace_get_payload_from_layer2().
1476 *
1477 * @li Layer 3/IP/IPv6 -- This can be retrieved by trace_get_layer3().  As a
1478 * convenience trace_get_ip()/trace_get_ip6() can be used to find an IPv4/IPv6
1479 * header.
1480 *
1481 * @li Layer 5/transport -- These are protocols carried in IPv4/IPv6 frames.
1482 * These can be retrieved using trace_get_transport().
1483 *
1484 * @{
1485 */
1486
1487
1488/** Gets a pointer to the first byte of the packet as it was captured and
1489 * returns its corresponding linktype and capture length.
1490 *
1491 * Use this function instead of the deprecated trace_get_link().
1492 *
1493 * @param packet The packet to get the buffer from
1494 * @param[out] linktype The linktype of the returned pointer
1495 * @param[out] remaining The capture length (the number of captured bytes from
1496 * the returned pointer)
1497 * @return A pointer to the first byte of the packet
1498 */
1499DLLEXPORT void *trace_get_packet_buffer(const libtrace_packet_t *packet,
1500                libtrace_linktype_t *linktype, uint32_t *remaining);
1501
1502/** Get a pointer to the link layer for a given packet
1503 * @param packet        The packet to get the link layer for
1504 *
1505 * @return A pointer to the link layer, or NULL if there is no link layer
1506 *
1507 * @deprecated This function is deprecated: Use trace_get_packet_buffer() or
1508 * one of the trace_get_layer*() functions instead.
1509 * @note You should call trace_get_link_type to find out what type of link
1510 * layer has been returned to you.
1511 */
1512DLLEXPORT SIMPLE_FUNCTION DEPRECATED
1513void *trace_get_link(const libtrace_packet_t *packet);
1514
1515/** Get a pointer to the IPv4 header (if any) for a given packet
1516 * @param packet        The packet to get the IPv4 header for
1517 *
1518 * @return A pointer to the IPv4 header, or NULL if there is no IPv4 header
1519 *
1520 * If a partial IP header is present, i.e. the packet has been truncated before
1521 * the end of the IP header, this function will return NULL.
1522 *
1523 * You should consider using \ref trace_get_layer3 instead of this function.
1524 */
1525DLLEXPORT SIMPLE_FUNCTION
1526libtrace_ip_t *trace_get_ip(libtrace_packet_t *packet);
1527
1528/** get a pointer to the IPv6 header (if any)
1529 * @param packet        The packet to get the IPv6 header for
1530 *
1531 * @return A pointer to the IPv6 header, or NULL if there is no IPv6 header
1532 *
1533 * If a partial IPv6 header is present, i.e. the packet has been truncated
1534 * before the end of the IP header, this function will return NULL.
1535 *
1536 * You should consider using \ref trace_get_layer3 instead of this function.
1537 */
1538DLLEXPORT SIMPLE_FUNCTION
1539libtrace_ip6_t *trace_get_ip6(libtrace_packet_t *packet);
1540
1541/** Return a pointer to the first metadata header in a packet, if present.
1542 *
1543 * This function takes a pointer to a libtrace packet and if any metadata
1544 * headers exist, returns a pointer to the first one, along with its
1545 * corresponding linktype.
1546 *
1547 * If no metadata headers exist in the packet, NULL is returned.
1548 *
1549 * A metadata header is a header that was prepended by the capturing device,
1550 * such as a Linux SLL header, or a Radiotap wireless monitoring header.
1551 * Subsequent metadata headers may be accessed with the
1552 * trace_get_payload_from_meta(...) function.
1553 *
1554 * @param packet The libtrace packet
1555 * @param[out] linktype The linktype of the returned metadata header
1556 * @param[out] remaining The number of bytes captured after the returned
1557 * pointer.
1558 * @return A pointer to the first metadata header, or NULL if there are no
1559 * metadata headers present.
1560 *
1561 * remaining may be NULL, however linktype must be provided.
1562 */
1563DLLEXPORT void *trace_get_packet_meta(const libtrace_packet_t *packet,
1564                libtrace_linktype_t *linktype,
1565                uint32_t *remaining);
1566
1567/** Returns the payload of a metadata header.
1568 *
1569 * This function takes a pointer to the start of a metadata header (either
1570 * obtained via trace_get_packet_meta(...) or by a previous call to
1571 * trace_get_payload_from_meta(...)) along with its corresponding linktype and
1572 * returns the payload, i.e. the next header. It will also update the linktype
1573 * parameter to indicate the type of payload.
1574 * 
1575 * If the linktype indicates that the header passed in is not a metadata
1576 * header, the function returns NULL to indicate this. The linktype remains
1577 * unchanged in this case.
1578 *
1579 * This function allows the user to iterate through metadata headers which are
1580 * sometimes present before the actual packet as it was received on the wire.
1581 * Examples of metadata headers include the Linux SLL header and the Radiotap
1582 * wireless monitoring header.
1583 *
1584 * If the metadata header passed into this function is truncated, this
1585 * function will return NULL, and remaining will be set to 0.
1586 *
1587 * If there are 0 bytes of payload following the provided metadata header, the
1588 * function will return a pointer to where the header would otherwise be and
1589 * remaining will be 0.
1590 *
1591 * Therefore, be sure to check the value of remaining after calling this
1592 * function!
1593 *
1594 * @param[in] meta A pointer to a metadata header
1595 * @param[in,out] linktype The linktype of meta (updated to indicate the
1596 * linktype of the returned header if applicable).
1597 * @param[in,out] remaining The number of bytes after the meta pointer.
1598 * @return A pointer to the payload of the metadata header. If meta is not a
1599 * pointer to a metadata header, NULL is returned and linktype remains
1600 * unchanged.
1601 *
1602 * All parameters are mandatory.
1603 */
1604DLLEXPORT void *trace_get_payload_from_meta(const void *meta,
1605                libtrace_linktype_t *linktype,
1606                uint32_t *remaining);
1607
1608
1609/** Get a pointer to the layer 2 header. Generally this is the first byte of the
1610 * packet as it was seen on the wire.
1611 *
1612 * This function takes a libtrace packet and skips over any metadata headers if
1613 * present (such as Linux SLL or Radiotap) and returns a pointer to the first
1614 * byte of the packet that was actually received by the network interface.
1615 *
1616 * @param packet The libtrace packet to find the layer 2 header for
1617 * @param[out] linktype The linktype of the returned layer 2 header
1618 * @param[out] remaining The number of bytes left in the packet after the
1619 * returned pointer.
1620 * @return A pointer to the first byte of the packet as it was seen on the
1621 * wire. If no layer 2 header is present, this function will return NULL.
1622 *
1623 * remaining may be NULL, otherwise it will be filled in by the function.
1624 */
1625DLLEXPORT void *trace_get_layer2(const libtrace_packet_t *packet,
1626                libtrace_linktype_t *linktype,
1627                uint32_t *remaining);
1628
1629/** Gets a pointer to the next header following a layer 2 header
1630 *
1631 * @param l2                    The pointer to the current layer 2 header
1632 * @param linktype              The type of the layer 2 header
1633 * @param[out] ethertype        An optional output variable of the ethernet type of the new header
1634 * @param[in,out] remaining     Updated with the number of captured bytes
1635                                remaining
1636 *
1637 * @return A pointer to the header following the provided layer 2 header, or
1638 * NULL if no subsequent header is present.
1639 *
1640 * Remaining must point to the number of bytes captured from the layer 2 header
1641 * and beyond.  It will be decremented by the number of bytes skipped to find
1642 * the payload.
1643 *
1644 * If the layer 2 header is complete but there are zero bytes of payload after
1645 * the end of the header, a pointer to where the payload would be is returned
1646 * and remaining will be set to 0.  If the layer 2 header is incomplete
1647 * (truncated), then NULL is returned and remaining will be set to 0.
1648 * Therefore, it is very important to check the value of remaining after
1649 * calling this function.
1650 *
1651 */
1652DLLEXPORT void *trace_get_payload_from_layer2(void *l2,
1653                libtrace_linktype_t linktype,
1654                uint16_t *ethertype,
1655                uint32_t *remaining);
1656
1657
1658/** Get a pointer to the layer 3 (e.g. IP) header.
1659 * @param packet  The libtrace packet to find the layer 3 header for
1660 * @param[out] ethertype The ethertype of the layer 3 header
1661 * @param[out] remaining The amount of captured data remaining in the packet starting from the returned pointer, i.e. including the layer 3 header.
1662 *
1663 * @return A pointer to the layer 3 header. If no layer 3 header is present in
1664 * the packet, NULL is returned. If the layer 3 header is truncated, a valid
1665 * pointer will still be returned so be sure to check the value of remaining
1666 * before attempting to process the returned header.
1667 *
1668 * remaining may be NULL, otherwise it will be set to the number of captured
1669 * bytes after the pointer returned.
1670 */
1671DLLEXPORT
1672void *trace_get_layer3(const libtrace_packet_t *packet,
1673                uint16_t *ethertype, uint32_t *remaining);
1674
1675/** Calculates the expected IP checksum for a packet.
1676 * @param packet        The libtrace packet to calculate the checksum for
1677 * @param[out] csum     The checksum that is calculated by this function. This
1678 *                      may not be NULL.
1679 *
1680 * @return A pointer to the original checksum field within the IP
1681 * header. If the checksum field is not present in the packet, NULL is returned.
1682 *
1683 * @note The return value points to the checksum that exists within the current
1684 * packet. The value in csum is the value that the checksum should be, given
1685 * the current packet contents. 
1686 *
1687 * @note This function involves the use of a memcpy, so be careful about
1688 * calling it excessively if performance is a concern for you.
1689 *
1690 * New in libtrace 3.0.17
1691 */
1692DLLEXPORT uint16_t *trace_checksum_layer3(libtrace_packet_t *packet,
1693                uint16_t *csum);
1694
1695/** Calculates the expected checksum for the transport header in a packet.
1696 * @param packet        The libtrace packet to calculate the checksum for
1697 * @param[out] csum     The checksum that is calculated by this function. This
1698 *                      may not be NULL.
1699 *
1700 * @return A pointer to the original checksum field within the transport
1701 * header. If the checksum field is not present in the packet, NULL is returned.
1702 *
1703 * @note The return value points to the checksum that exists within the current
1704 * packet. The value in csum is the value that the checksum should be, given
1705 * the current packet contents. 
1706 *
1707 * @note This function involves the use of a memcpy, so be careful about
1708 * calling it excessively if performance is a concern for you.
1709 *
1710 * @note Because transport checksums are calculated across the entire payload,
1711 * truncated packets will result in NULL being returned.
1712 *
1713 * This function will determine the appropriate checksum for whatever transport
1714 * layer header is present in the provided packet. At this stage, this only
1715 * currently works for TCP, UDP and ICMP packets.
1716 *
1717 * Be wary of TCP checksum offloading if you are examining the checksum of
1718 * packets captured on the same host that generated them!
1719 *
1720 * New in libtrace 3.0.17
1721 */
1722DLLEXPORT uint16_t *trace_checksum_transport(libtrace_packet_t *packet,
1723                uint16_t *csum);
1724
1725/** Gets a pointer to the transport layer header (if any)
1726 * @param packet   The libtrace packet to find the transport header for
1727 * @param[out] proto    The protocol present at the transport layer.
1728 * @param[out] remaining The amount of captured data remaining in the packet
1729 * starting from the returned pointer, i.e. including the transport header.
1730 *
1731 * @return A pointer to the transport layer header. If no transport header is
1732 * present in the packet, NULL is returned. If the transport header is
1733 * truncated, a valid pointer will still be returned so be sure to check the
1734 * value of remaining before attempting to process the returned header.
1735 *
1736 * remaining may be NULL, otherwise it will be set to the number of captured
1737 * bytes after the returned pointer.
1738 *
1739 * @note proto may be NULL if proto is unneeded.
1740 */
1741DLLEXPORT void *trace_get_transport(const libtrace_packet_t *packet,
1742                uint8_t *proto, uint32_t *remaining);
1743
1744/** Gets a pointer to the payload following an IPv4 header
1745 * @param ip            The IPv4 Header
1746 * @param[out] proto    The protocol of the header following the IPv4 header
1747 * @param[in,out] remaining Updated with the number of captured bytes remaining
1748 *
1749 * @return A pointer to the transport layer header, or NULL if no subsequent
1750 * header is present.
1751 *
1752 * When calling this function, remaining must contain the number of captured
1753 * bytes remaining in the packet starting from the IPv4 header (including the
1754 * IPv4 header itself).
1755 *
1756 * remaining will be decremented by the size of the IPv4 header (including any
1757 * options). If the IPv4 header is complete but there are zero bytes of payload
1758 * after the IPv4 header, a pointer to where the payload would be is returned
1759 * and remaining will be set to 0.  If the IPv4 header is incomplete, NULL will
1760 * be returned and remaining will be set to 0. Therefore, it is very important
1761 * to check the value of remaining after calling this function.
1762 *
1763 * proto may be NULL, in which case it won't be updated.
1764 *
1765 * @note This is similar to trace_get_transport_from_ip in libtrace2
1766 */
1767DLLEXPORT void *trace_get_payload_from_ip(libtrace_ip_t *ip, uint8_t *proto,
1768                uint32_t *remaining);
1769
1770/** Gets a pointer to the payload following an IPv6 header
1771 * @param ipptr         The IPv6 Header
1772 * @param[out] proto    The protocol of the header following the IPv6 header
1773 * @param[in,out] remaining Updated with the number of captured bytes remaining
1774 *
1775 * @return A pointer to the transport layer header, or NULL if no subsequent
1776 * header is present.
1777 *
1778 * When calling this function, remaining must contain the number of captured
1779 * bytes remaining in the packet starting from the IPv6 header (including the
1780 * IPv6 header itself).
1781 *
1782 * remaining will be decremented by the size of the IPv6 header (including any
1783 * options). If the IPv6 header is complete but there are zero bytes of payload
1784 * after the IPv6 header, a pointer to where the payload would be is returned
1785 * and remaining will be set to 0.  If the IPv6 header is incomplete, NULL will
1786 * be returned and remaining will be set to 0. Therefore, it is very important
1787 * to check the value of remaining after calling this function.
1788 *
1789 * proto may be NULL, in which case it won't be updated.
1790 *
1791 */
1792DLLEXPORT void *trace_get_payload_from_ip6(libtrace_ip6_t *ipptr,
1793                uint8_t *proto, uint32_t *remaining);
1794
1795/** Gets a pointer to the payload following a link header
1796 * @param linkptr       A pointer to the link layer header
1797 * @param linktype      The linktype of the link header being examined
1798 * @param[out] type     An output variable for the ethernet type
1799 * @param[in,out] remaining Updated with the number of captured bytes remaining
1800 *
1801 * @return A pointer to the header following the link header, or NULL if no
1802 * subsequent header is present.
1803 *
1804 * When calling this function, remaining must contain the number of captured
1805 * bytes remaining in the packet starting from the link header (including the
1806 * link header itself). remaining will be updated to contain the number of
1807 * bytes remaining after the link header has been skipped.
1808 *
1809 * @deprecated This function is deprecated: you should be using
1810 * trace_get_payload_from_layer2() or trace_get_payload_from_meta() instead.
1811 *
1812 */
1813DLLEXPORT void *trace_get_payload_from_link(void *linkptr,
1814                libtrace_linktype_t linktype,
1815                uint16_t *type, uint32_t *remaining);
1816
1817/** Gets a pointer to the payload following an 802.1q (VLAN) header.
1818 * @param vlan      A pointer to the VLAN header
1819 * @param[out] type  The ethernet type, replaced with the VLAN ether type
1820 * @param[in,out] remaining Updated with the number of captured bytes remaining
1821 *
1822 * @return A pointer to the header beyond the VLAN header, if one is present.
1823 * Otherwise, returns NULL. 
1824 *
1825 * When calling this function, remaining must contain the number of captured
1826 * bytes remaining in the packet starting from the VLAN header (including the
1827 * VLAN header itself). remaining will be updated to contain the number of
1828 * bytes remaining after the VLAN header has been skipped.
1829 *
1830 * If the VLAN header is complete but there are zero bytes of payload after
1831 * the VLAN header, a pointer to where the payload would be is returned and
1832 * remaining will be set to 0.  If the VLAN header is incomplete, NULL will be
1833 * returned and remaining will be set to 0. Therefore, it is important to check
1834 * the value of remaining after calling this function.
1835 *
1836 * type will be set to the ethertype of the VLAN payload. This parameter is not
1837 * mandatory, but is highly recommended.
1838 *
1839 */
1840DLLEXPORT void *trace_get_payload_from_vlan(
1841                void *vlan, uint16_t *type, uint32_t *remaining);
1842
1843/** Gets a pointer to the payload following an MPLS header.
1844 * @param mpls      A pointer to the MPLS header
1845 * @param[out] type  The ethernet type, replaced by the ether type of the
1846 * returned header - 0x0000 if an Ethernet header is returned
1847 * @param[in,out] remaining Updated with the number of captured bytes remaining
1848 *
1849 * @return A pointer to the header beyond the MPLS label, if one is present.
1850 * Will return NULL if there is not enough bytes remaining to skip past the
1851 * MPLS label.
1852 *
1853 * When calling this function, remaining must contain the number of captured
1854 * bytes remaining in the packet starting from the MPLS header (including the
1855 * MPLS header itself). remaining will be updated to contain the number of
1856 * bytes remaining after the MPLS header has been skipped.
1857 *
1858 * If the MPLS header is complete but there are zero bytes of payload after
1859 * the MPLS header, a pointer to where the payload would be is returned and
1860 * remaining will be set to 0.  If the MPLS header is incomplete, NULL will be
1861 * returned and remaining will be set to 0. Therefore, it is important to check
1862 * the value of remaining after calling this function.
1863 *
1864 * type will be set to the ethertype of the MPLS payload. This parameter is
1865 * mandatory - it may not be NULL.
1866 *
1867 * @note This function will only remove one MPLS label at a time - the type
1868 * will be set to 0x8847 if there is another MPLS label following the one
1869 * skipped by this function.
1870 *
1871 */
1872DLLEXPORT void *trace_get_payload_from_mpls(
1873                void *mpls, uint16_t *type, uint32_t *remaining);
1874
1875/** Gets a pointer to the payload following a PPPoE header
1876 * @param pppoe      A pointer to the PPPoE header
1877 * @param[out] type  The ethernet type, replaced by the ether type of the
1878 * returned header - 0x0000 if an Ethernet header is returned
1879 * @param[in,out] remaining  Updated with the number of captured bytes remaining
1880 *
1881 * @return A pointer to the header beyond the PPPoE header. NOTE that this
1882 * function will also skip over the PPP header that will immediately follow
1883 * the PPPoE header. This function will return NULL if there are not enough
1884 * bytes remaining to skip past both the PPPoE and PPP headers.
1885 *
1886 * When calling this function, remaining must contain the number of captured
1887 * bytes remaining in the packet starting from the PPPoE header (including the
1888 * PPPoE header itself). remaining will be updated to contain the number of
1889 * bytes remaining after the PPPoE and PPP headers have been removed.
1890 *
1891 * If the PPPoE and PPP headers are complete but there are zero bytes of
1892 * payload after the PPP header, a pointer to where the payload would be is
1893 * returned and remaining will be set to 0.  If the PPPoE or PPP header is
1894 * incomplete, NULL will be returned and remaining will be set to 0. Therefore,
1895 * it is important to check the value of remaining after calling this function.
1896 *
1897 * type will be set to the ether type of the PPP payload. This parameter is
1898 * mandatory - it may not be NULL.
1899 *
1900 */
1901DLLEXPORT void *trace_get_payload_from_pppoe(
1902                void *pppoe, uint16_t *type, uint32_t *remaining);
1903
1904/** Gets a pointer to the payload following a TCP header
1905 * @param tcp           A pointer to the TCP header
1906 * @param[in,out] remaining Updated with the number of captured bytes remaining
1907 *
1908 * @return A pointer to the TCP payload, or NULL if the TCP header is truncated.
1909 *
1910 * When calling this function, remaining must contain the number of captured
1911 * bytes remaining in the packet starting from the TCP header (including the
1912 * TCP header itself). remaining will be updated to contain the number of
1913 * bytes remaining after the TCP header has been skipped.
1914 *
1915 * If the TCP header is complete but there are zero bytes of payload after
1916 * the TCP header, a pointer to where the payload would be is returned and
1917 * remaining will be set to 0.  If the TCP header is incomplete, NULL will be
1918 * returned and remaining will be set to 0. Therefore, it is important to check
1919 * the value of remaining after calling this function.
1920 *
1921 */
1922DLLEXPORT void *trace_get_payload_from_tcp(libtrace_tcp_t *tcp,
1923                uint32_t *remaining);
1924
1925/** Gets a pointer to the payload following a UDP header
1926 * @param udp           A pointer to the UDP header
1927 * @param[in,out] remaining Updated with the number of captured bytes remaining
1928 *
1929 * @return A pointer to the UDP payload, or NULL if the UDP header is truncated.
1930 *
1931 * When calling this function, remaining must contain the number of captured
1932 * bytes remaining in the packet starting from the UDP header (including the
1933 * UDP header itself). remaining will be updated to contain the number of
1934 * bytes remaining after the UDP header has been skipped.
1935 *
1936 * If the UDP header is complete but there are zero bytes of payload after
1937 * the UDP header, a pointer to where the payload would be is returned and
1938 * remaining will be set to 0.  If the UDP header is incomplete, NULL will be
1939 * returned and remaining will be set to 0. Therefore, it is important to check
1940 * the value of remaining after calling this function.
1941 *
1942 */
1943DLLEXPORT void *trace_get_payload_from_udp(libtrace_udp_t *udp, uint32_t *remaining);
1944
1945/** Gets a pointer to the payload following a ICMP header
1946 * @param icmp           A pointer to the ICMP header
1947 * @param[in,out] remaining Updated with the number of captured bytes remaining
1948 *
1949 * @return A pointer to the ICMP payload, or NULL if the ICMP header is
1950 * truncated.
1951 *
1952 * When calling this function, remaining must contain the number of captured
1953 * bytes remaining in the packet starting from the ICMP header (including the
1954 * ICMP header itself). remaining will be updated to contain the number of
1955 * bytes remaining after the ICMP header has been skipped.
1956 *
1957 * If the ICMP header is complete but there are zero bytes of payload after
1958 * the ICMP header, a pointer to where the payload would be is returned and
1959 * remaining will be set to 0.  If the ICMP header is incomplete, NULL will be
1960 * returned and remaining will be set to 0. Therefore, it is important to check
1961 * the value of remaining after calling this function.
1962 *
1963 * @note In the case of some ICMP messages, the payload may be the IP header
1964 * from the packet that triggered the ICMP message.
1965 *
1966 */
1967DLLEXPORT void *trace_get_payload_from_icmp(libtrace_icmp_t *icmp,
1968                uint32_t *remaining);
1969
1970/** Gets a pointer to the payload following a ICMPv6 header
1971 * @param icmp           A pointer to the ICMPv6 header
1972 * @param[in,out] remaining Updated with the number of captured bytes remaining
1973 *
1974 * @return A pointer to the ICMPv6 payload, or NULL if the ICMPv6 header is
1975 * truncated.
1976 *
1977 * When calling this function, remaining must contain the number of captured
1978 * bytes remaining in the packet starting from the ICMPv6 header (including the
1979 * ICMP header itself). remaining will be updated to contain the number of
1980 * bytes remaining after the ICMPv6 header has been skipped.
1981 *
1982 * If the ICMPv6 header is complete but there are zero bytes of payload after
1983 * the header, a pointer to where the payload would be is returned and
1984 * remaining will be set to 0.  If the ICMPv6 header is incomplete, NULL will be
1985 * returned and remaining will be set to 0. Therefore, it is important to check
1986 * the value of remaining after calling this function.
1987 *
1988 * @note In the case of some ICMPv6 messages, the payload may be the IP header
1989 * from the packet that triggered the ICMP message.
1990 *
1991 */
1992DLLEXPORT void *trace_get_payload_from_icmp6(libtrace_icmp6_t *icmp,
1993                uint32_t *remaining);
1994
1995/** Get a pointer to the TCP header (if present)
1996 * @param packet        The packet to get the TCP header from
1997 *
1998 * @return A pointer to the TCP header, or NULL if there is not a complete TCP
1999 * header present in the packet.
2000 *
2001 * This is a short-cut function enabling quick and easy access to the TCP
2002 * header if that is all you care about. However, we recommend the use of the
2003 * more generic trace_get_transport() function instead.
2004 *
2005 * @note Unlike trace_get_transport(), this function will return NULL if the
2006 * TCP header is incomplete or truncated.
2007 */
2008DLLEXPORT SIMPLE_FUNCTION
2009libtrace_tcp_t *trace_get_tcp(libtrace_packet_t *packet);
2010
2011/** Get a pointer to the TCP header following an IPv4 header (if present)
2012 * @param ip            The IP header to find the subsequent TCP header for
2013 * @param[in,out] remaining Updated with the number of captured bytes remaining
2014 *
2015 * @return A pointer to the TCP header, or NULL if no TCP header is present in
2016 * the packet.
2017 *
2018 * When calling this function, remaining must contain the number of captured
2019 * bytes remaining in the packet starting from the IP header (including the
2020 * IP header itself). remaining will be updated to contain the number of
2021 * bytes remaining after the IP header has been skipped.
2022 *
2023 * If the IP header is complete but there are zero bytes of payload after
2024 * the IP header, a pointer to where the payload would be is returned and
2025 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
2026 * returned and remaining will be set to 0. Therefore, it is important to check
2027 * the value of remaining after calling this function.
2028 *
2029 * @note This function is rather redundant now that the layer 3 header is
2030 * cached. There should be no performance advantage for the user to call this
2031 * function over just calling trace_get_transport().
2032 *
2033 * @note The last parameter has changed from libtrace2
2034 */
2035DLLEXPORT SIMPLE_FUNCTION
2036libtrace_tcp_t *trace_get_tcp_from_ip(libtrace_ip_t *ip, uint32_t *remaining);
2037
2038/** Get a pointer to the UDP header (if present)
2039 * @param packet        The packet to get the UDP header from
2040 *
2041 * @return A pointer to the UDP header, or NULL if there is not a complete UDP
2042 * header present in the packet.
2043 *
2044 * This is a short-cut function enabling quick and easy access to the UDP
2045 * header if that is all you care about. However, we recommend the use of the
2046 * more generic trace_get_transport() function instead.
2047 *
2048 * @note Unlike trace_get_transport(), this function will return NULL if the
2049 * UDP header is incomplete or truncated.
2050 */
2051DLLEXPORT SIMPLE_FUNCTION
2052libtrace_udp_t *trace_get_udp(libtrace_packet_t *packet);
2053
2054/** Get a pointer to the UDP header following an IPv4 header (if present)
2055 * @param ip            The IP header to find the subsequent UDP header for
2056 * @param[in,out] remaining Updated with the number of captured bytes remaining
2057 *
2058 * @return A pointer to the UDP header, or NULL if no UDP header is present in
2059 * the packet.
2060 *
2061 * When calling this function, remaining must contain the number of captured
2062 * bytes remaining in the packet starting from the IP header (including the
2063 * IP header itself). remaining will be updated to contain the number of
2064 * bytes remaining after the IP header has been skipped.
2065 *
2066 * If the IP header is complete but there are zero bytes of payload after
2067 * the IP header, a pointer to where the payload would be is returned and
2068 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
2069 * returned and remaining will be set to 0. Therefore, it is important to check
2070 * the value of remaining after calling this function.
2071 *
2072 * @note This function is rather redundant now that the layer 3 header is
2073 * cached. There should be no performance advantage for the user to call this
2074 * function over just calling trace_get_transport().
2075 *
2076 * @note The last parameter has changed from libtrace2
2077 */
2078DLLEXPORT SIMPLE_FUNCTION
2079libtrace_udp_t *trace_get_udp_from_ip(libtrace_ip_t *ip,uint32_t *remaining);
2080
2081/** Get a pointer to the ICMP header (if present)
2082 * @param packet        The packet to get the ICMP header from
2083 *
2084 * @return A pointer to the ICMP header, or NULL if there is not a complete
2085 * ICMP header present in the packet.
2086 *
2087 * This is a short-cut function enabling quick and easy access to the ICMP
2088 * header if that is all you care about. However, we recommend the use of the
2089 * more generic trace_get_transport() function instead.
2090 *
2091 * @note Unlike trace_get_transport(), this function will return NULL if the
2092 * ICMP header is incomplete or truncated.
2093 */
2094DLLEXPORT SIMPLE_FUNCTION
2095libtrace_icmp_t *trace_get_icmp(libtrace_packet_t *packet);
2096
2097/** Get a pointer to the ICMPv6 header (if present)
2098 * @param packet        The packet to get the ICMPv6 header from
2099 *
2100 * @return A pointer to the ICMPv6 header, or NULL if there is not a complete
2101 * ICMP header present in the packet.
2102 *
2103 * This is a short-cut function enabling quick and easy access to the ICMPv6
2104 * header if that is all you care about. However, we recommend the use of the
2105 * more generic trace_get_transport() function instead.
2106 *
2107 * @note Unlike trace_get_transport(), this function will return NULL if the
2108 * ICMPv6 header is incomplete or truncated.
2109 */
2110DLLEXPORT SIMPLE_FUNCTION
2111libtrace_icmp6_t *trace_get_icmp6(libtrace_packet_t *packet);
2112
2113/** Get a pointer to the ICMP header following an IPv4 header (if present)
2114 * @param ip            The IP header to find the subsequent ICMP header for
2115 * @param[in,out] remaining Updated with the number of captured bytes remaining
2116 *
2117 * @return A pointer to the ICMP header, or NULL if no UDP header is present in
2118 * the packet.
2119 *
2120 * When calling this function, remaining must contain the number of captured
2121 * bytes remaining in the packet starting from the IP header (including the
2122 * IP header itself). remaining will be updated to contain the number of
2123 * bytes remaining after the IP header has been skipped.
2124 *
2125 * If the IP header is complete but there are zero bytes of payload after
2126 * the IP header, a pointer to where the payload would be is returned and
2127 * remaining will be set to 0.  If the IP header is incomplete, NULL will be
2128 * returned and remaining will be set to 0. Therefore, it is important to check
2129 * the value of remaining after calling this function.
2130 *
2131 * @note This function is rather redundant now that the layer 3 header is
2132 * cached. There should be no performance advantage for the user to call this
2133 * function over just calling trace_get_transport().
2134 *
2135 * @note The last parameter has changed from libtrace2
2136 */
2137DLLEXPORT SIMPLE_FUNCTION
2138libtrace_icmp_t *trace_get_icmp_from_ip(libtrace_ip_t *ip,uint32_t *remaining);
2139
2140/** Get a pointer to the OSPF header (if present)
2141 * @param packet        The packet to get the OSPF header from
2142 * @param[out] version  The OSPF version number
2143 * @param[out] remaining        Updated with the number of captured bytes remaining
2144 * @return A pointer to the start of the OSPF header or NULL if there is no
2145 * complete OSPF header present in the packet
2146 *
2147 * This is a short-cut function enabling quick and easy access to the OSPF
2148 * header. If you only care about the OSPF header, this function may be useful
2149 * but we otherwise recommend the use of the more generic trace_get_transport()
2150 * function instead.
2151 *
2152 * Upon return, 'version' is updated to contain the OSPF version number for the
2153 * packet so that the returned pointer may be cast to the correct type.
2154 * The version parameter MUST contain a valid pointer; it MUST NOT be NULL.
2155 *
2156 * 'remaining' is also set to contain the number of captured bytes remaining
2157 * starting from the pointer returned by this function.
2158 *
2159 * @note Unlike trace_get_transport(), this function will return NULL if the
2160 * OSPF header is incomplete or truncated.
2161 */
2162DLLEXPORT SIMPLE_FUNCTION
2163void *trace_get_ospf_header(libtrace_packet_t *packet, uint8_t *version,
2164                uint32_t *remaining);
2165
2166/** Get a pointer to the contents of the OSPF packet *after* the OSPF header
2167 * @param header        The OSPF header to get the OSPF contents from
2168 * @param[out] ospf_type        The OSPF packet type
2169 * @param[in, out] remaining    Updated with the number of captured bytes remaining
2170 * @return A pointer to the first byte after the OSPF header.
2171 *
2172 * This function returns a void pointer that can be cast appropriately
2173 * based on the ospf_type. For example, if the ospf_type is TRACE_OSPF_HELLO
2174 * then the return pointer should be cast as a libtrace_ospf_hello_v2_t
2175 * structure.
2176 *
2177 * If the OSPF header is truncated, then NULL will be returned. If the OSPF
2178 * contents are missing or truncated, the pointer to the start of the content
2179 * will still be returned so be careful to check the value of remaining.
2180 *
2181 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2182 * packet starting from the beginning of the OSPF header. It will be updated
2183 * to contain the number of bytes remaining from the start of the OSPF contents.
2184 *
2185 * @note This function only works for OSPF version 2 packets.
2186 * @note Use trace_get_first_ospf_lsa_v2_from_X() and trace_get_next_ospf_lsa_v2() to read the LSAs from Link State Update packets.
2187 * @note Use trace_get_first_ospf_lsa_v2_from_X() and trace_get_next_ospf_lsa_header_v2() to read the LSA headers from Link State Ack packets.
2188 *
2189 */
2190DLLEXPORT SIMPLE_FUNCTION
2191void *trace_get_ospf_contents_v2(libtrace_ospf_v2_t *header,
2192                uint8_t *ospf_type, uint32_t *remaining);
2193
2194/** Get a pointer to the start of the first LSA contained within an LS Update packet
2195 * @param ls_update     Pointer to the LS Update header
2196 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2197 * @return A pointer to the first LSA in the packet.
2198 *
2199 * This function simply skips past the LS Update header to provide a suitable
2200 * pointer to pass into trace_get_next_ospf_lsa_v2.
2201 *
2202 * If the OSPF packet is truncated, then NULL will be returned.
2203 *
2204 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2205 * packet starting from the beginning of the LS Update header. It will be
2206 * updated to contain the number of bytes remaining from the start of the
2207 * first LSA.
2208 *
2209 * @note This function only works for OSPF version 2 packets.
2210 * @note trace_get_next_ospf_lsa_v2() should be subequently used to process the LSAs
2211 */
2212DLLEXPORT SIMPLE_FUNCTION
2213unsigned char *trace_get_first_ospf_lsa_from_update_v2(
2214                libtrace_ospf_ls_update_t *ls_update,
2215                uint32_t *remaining);
2216
2217/** Get a pointer to the start of the first LSA contained within an Database Description packet
2218 * @param db_desc       Pointer to the Database Description header
2219 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2220 * @return A pointer to the first LSA in the packet.
2221 *
2222 * This function simply skips past the Database Description header to provide a
2223 * suitable pointer to pass into trace_get_next_ospf_lsa_header_v2.
2224 *
2225 * If the OSPF packet is truncated, then NULL will be returned.
2226 *
2227 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2228 * packet starting from the beginning of the Database Description header. It
2229 * will be updated to contain the number of bytes remaining from the start of
2230 * the first LSA.
2231 *
2232 * @note This function only works for OSPF version 2 packets.
2233 * @note trace_get_next_ospf_lsa_header_v2() should be subequently used to process the LSA headers
2234 */
2235DLLEXPORT SIMPLE_FUNCTION
2236unsigned char *trace_get_first_ospf_lsa_from_db_desc_v2(
2237                libtrace_ospf_db_desc_v2_t *db_desc,
2238                uint32_t *remaining);
2239
2240/** Get a pointer to the start of the first link contained within a Router LSA
2241 * @param lsa   Pointer to the Router LSA
2242 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2243 * @return A pointer to the first link in the packet.
2244 *
2245 * This function simply skips past the Router LSA header to provide a
2246 * suitable pointer to pass into trace_get_next_ospf_link_v2.
2247 *
2248 * If the OSPF packet is truncated, then NULL will be returned.
2249 *
2250 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2251 * packet starting from the beginning of the Router LSA (not including the LSA
2252 * header) header. It will be updated to contain the number of bytes remaining
2253 * from the start of the first Link.
2254 *
2255 * @note This function only works for OSPF version 2 packets.
2256 * @note trace_get_next_ospf_link_v2() should be subequently used to process
2257 * the links
2258 */
2259DLLEXPORT SIMPLE_FUNCTION
2260unsigned char *trace_get_first_ospf_link_from_router_lsa_v2(
2261                libtrace_ospf_router_lsa_v2_t *lsa,
2262                uint32_t *remaining);
2263
2264/** Parses an OSPF Router LSA Link and finds the next Link (if there is one)
2265 * @param[in,out] current       Pointer to the next Link (updated by this function)
2266 * @param[out] link             Set to point to the Link located at the original value of current
2267 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2268 * @param[out] link_len         Set to the size of the Link pointed to by 'link'
2269 * @return 0 if there are no more links after the current one, 1 otherwise.
2270 *
2271 * When called, 'current' MUST point to an OSPF Router LSA link. Ideally, this
2272 * would come from either a call to
2273 * trace_get_first_ospf_link_from_router_lsa_v2() or a previous call of this
2274 * function.
2275 *
2276 * 'link' will be set to the value of 'current', so that the caller may then
2277 * do any processing they wish on that particular link. 'current' is advanced
2278 * to point to the next link and 'link_len' is updated to report the size of
2279 * the original link.
2280 *
2281 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2282 * packet starting from the beginning of the Link pointed to by 'current'.
2283 * It will be updated to contain the number of bytes remaining from the start
2284 * of the next link.
2285 *
2286 * If this function returns 0 but 'link' is NOT NULL, that link is still valid
2287 * but there are no more links after this one.
2288 * If this function returns 0 AND link is NULL, the link is obviously not
2289 * suitable for processing.
2290 *
2291 * @note This function only works for OSPF version 2 packets.
2292 */
2293DLLEXPORT SIMPLE_FUNCTION
2294int trace_get_next_ospf_link_v2(unsigned char **current,
2295                libtrace_ospf_link_v2_t **link,
2296                uint32_t *remaining,
2297                uint32_t *link_len);
2298
2299/** Parses an OSPF LSA and finds the next LSA (if there is one)
2300 * @param[in,out] current       Pointer to the next LSA (updated by this function)
2301 * @param[out] lsa_hdr          Set to point to the header of the LSA located at the original value of current
2302 * @param[out] lsa_body         Set to point to the body of the LSA located at the original value of current
2303 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2304 * @param[out] lsa_type         Set to the type of the LSA located at the original value of current
2305 * @param[out] lsa_length       Set to the size of the LSA located at the original value of current
2306 * @return 1 if there are more LSAs after the current one, 0 if there are no more LSAs to come, and -1 if the current LSA is incomplete, truncated or invalid.
2307 *
2308 * When called, 'current' MUST point to an OSPF LSA. Ideally, this would come
2309 * from either a call to trace_get_first_ospf_lsa_from_update_v2() or a
2310 * previous call of this function.
2311 *
2312 * This function should only be used to access COMPLETE LSAs, i.e. LSAs that
2313 * have both a header and a body. In OSPFv2, only the LSAs contained within
2314 * LSA Update packets meet this requirement. trace_get_next_ospf_lsa_header_v2
2315 * should be used to read header-only LSAs, e.g. those present in LS Acks.
2316 *
2317 * 'lsa_hdr' will be set to the value of 'current', so that the caller may then
2318 * do any processing they wish on that particular LSA. 'lsa_body' will be set
2319 * to point to the first byte after the LSA header. 'current' is advanced
2320 * to point to the next LSA. 'lsa_length' is updated to contain the size of
2321 * the parsed LSA, while 'lsa_type' is set to indicate the LSA type.
2322 *
2323 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2324 * packet starting from the beginning of the LSA pointed to by 'current'.
2325 * It will be updated to contain the number of bytes remaining from the start
2326 * of the next LSA.
2327 *
2328 * If this function returns 0 but 'lsa_hdr' is NOT NULL, that LSA is still
2329 * valid but there are no more LSAs after this one.
2330 * If this function returns 0 AND 'lsa_hdr' is NULL, the LSA is obviously not
2331 * suitable for processing.
2332 *
2333 * It is also recommended to check the value of 'lsa_body' before
2334 * de-referencing it. 'lsa_body' will be set to NULL if there is only an LSA
2335 * header present.
2336 *
2337 * @note This function only works for OSPF version 2 packets.
2338 *
2339 */
2340DLLEXPORT SIMPLE_FUNCTION
2341int trace_get_next_ospf_lsa_v2(unsigned char **current,
2342                libtrace_ospf_lsa_v2_t **lsa_hdr,
2343                unsigned char **lsa_body,
2344                uint32_t *remaining,
2345                uint8_t *lsa_type,
2346                uint16_t *lsa_length);
2347
2348/** Parses an OSPF LSA header and finds the next LSA (if there is one)
2349 * @param[in,out] current       Pointer to the next LSA (updated by this function)
2350 * @param[out] lsa_hdr          Set to point to the header of the LSA located at the original value of current
2351 * @param[in,out] remaining     Updated with the number of captured bytes remaining
2352 * @param[out] lsa_length       Set to the size of the LSA located at the original value of current
2353 * @return 1 if there are more LSAs after the current one, 0 if there are no more LSAs to come, and -1 if the current LSA is incomplete, truncated or invalid.
2354 *
2355 * When called, 'current' MUST point to an OSPF LSA. Ideally, this would come
2356 * from either a call to trace_get_first_ospf_lsa_from_db_desc_v2() or a
2357 * previous call of this function.
2358 *
2359 * This function should only be used to access LSA headers, i.e. LSAs that
2360 * have a header only. In OSPFv2, the LSAs contained within LSA Ack and
2361 * Database Description packets meet this requirement.
2362 * trace_get_next_ospf_lsa_v2 should be used to read full LSAs, e.g. those
2363 * present in LS Updates.
2364 *
2365 * 'lsa_hdr' will be set to the value of 'current', so that the caller may then
2366 * do any processing they wish on that particular LSA header. 'current' is
2367 * advanced to point to the next LSA header. 'lsa_length' is updated to contain
2368 * the size of the parsed LSA header.
2369 *
2370 * 'remaining' MUST be set to the amount of bytes remaining in the captured
2371 * packet starting from the beginning of the LSA pointed to by 'current'.
2372 * It will be updated to contain the number of bytes remaining from the start
2373 * of the next LSA.
2374 *
2375 * If this function returns 0 but 'lsa_hdr' is NOT NULL, that LSA is still
2376 * valid but there are no more LSAs after this one.
2377 * If this function returns 0 AND 'lsa_hdr' is NULL, the LSA is obviously not
2378 * suitable for processing.
2379 *
2380 * @note This function only works for OSPF version 2 packets.
2381 *
2382 */
2383DLLEXPORT SIMPLE_FUNCTION
2384int trace_get_next_ospf_lsa_header_v2(unsigned char **current,
2385                libtrace_ospf_lsa_v2_t **lsa_hdr,
2386                uint32_t *remaining,
2387                uint8_t *lsa_type,
2388                uint16_t *lsa_length);
2389
2390/** Extracts the metric field from an AS External LSA packet
2391 *
2392 * @param as_lsa        The AS External LSA
2393 * @returns The value of the metric field
2394 *
2395 * The metric field in the AS External LSA packet is a 24-bit value, which
2396 * is difficult to extract correctly. To avoid byte-ordering issues, use this
2397 * function which will extract the correct value for you.
2398 */
2399DLLEXPORT SIMPLE_FUNCTION
2400uint32_t trace_get_ospf_metric_from_as_external_lsa_v2(
2401                libtrace_ospf_as_external_lsa_v2_t *as_lsa);
2402
2403/** Extracts the metric field from a Summary LSA packet
2404 *
2405 * @param sum_lsa       The Summary LSA
2406 * @returns The value of the metric field
2407 *
2408 * The metric field in the Summary LSA packet is a 24-bit value, which
2409 * is difficult to extract correctly. To avoid byte-ordering issues, use this
2410 * function which will extract the correct value for you.
2411 */
2412DLLEXPORT SIMPLE_FUNCTION
2413uint32_t trace_get_ospf_metric_from_summary_lsa_v2(
2414                libtrace_ospf_summary_lsa_v2_t *sum_lsa);
2415
2416
2417/** Gets the destination MAC address for a given packet
2418 * @param packet        The packet to extract the destination MAC address from
2419 *
2420 * @return A pointer to the destination MAC address field in the layer 2
2421 * header, (or NULL if there is no destination MAC address or layer 2 header
2422 * available)
2423 *
2424 * @note This is a zero-copy function, so the memory that the returned pointer
2425 * points to is part of the packet itself.
2426 */
2427DLLEXPORT SIMPLE_FUNCTION
2428uint8_t *trace_get_destination_mac(libtrace_packet_t *packet);
2429
2430/** Gets the source MAC address for a given packet
2431 * @param packet        The packet to extract the source MAC address from
2432 *
2433 * @return A pointer to the source MAC address field in the layer 2
2434 * header, (or NULL if there is no source MAC address or layer 2 header
2435 * available)
2436 *
2437 * @note This is a zero-copy function, so the memory that the returned pointer
2438 * points to is part of the packet itself.
2439 */
2440DLLEXPORT SIMPLE_FUNCTION
2441uint8_t *trace_get_source_mac(libtrace_packet_t *packet);
2442
2443/** Get the source IP address for a given packet
2444 * @param packet        The packet to extract the source IP address from
2445 * @param addr          A pointer to a sockaddr structure to store the address
2446 *                      in. If NULL, static storage is used instead.
2447 * @return A pointer to a sockaddr holding a v4 or v6 IP address or on some
2448 * platforms a sockaddr holding a MAC address. Returns NULL if no source IP
2449 * address was available.
2450 *
2451 * @note The best way to use this function is to pass in a pointer to the
2452 * struct sockaddr_storage for the addr parameter. This will avoid problems
2453 * with trying to shoe-horn an IPv6 address into a sockaddr that only supports
2454 * IPv4.
2455 */
2456DLLEXPORT SIMPLE_FUNCTION
2457struct sockaddr *trace_get_source_address(const libtrace_packet_t *packet,
2458                struct sockaddr *addr);
2459
2460/** Get the source IP address for a packet and convert it into a string
2461 * @param packet        The packet to extract the source IP address from
2462 * @param space         A pointer to a character buffer to store the address
2463 *                      in. If NULL, static storage is used instead.
2464 * @param spacelen      The size of the buffer passed in via 'space'. Set this
2465 *                      to zero if you are going to pass in a NULL buffer.
2466 * @return A pointer to a character buffer containing the string representation
2467 * of the source IP address. For packets where there is no suitable IP address,
2468 * the source MAC will be returned instead. Returns NULL if no valid address
2469 * is available.
2470 *
2471 * @note Be wary of the possibility of the address being an IPv6 address - make
2472 * sure your buffer is large enough!
2473 *
2474 * New in libtrace 3.0.17.
2475 */
2476DLLEXPORT SIMPLE_FUNCTION
2477char *trace_get_source_address_string(const libtrace_packet_t *packet,
2478                char *space, int spacelen);
2479
2480/** Get the destination IP address for a given packet
2481 * @param packet        The packet to extract the destination IP address from
2482 * @param addr          A pointer to a sockaddr structure to store the address
2483 *                      in. If NULL, static storage is used instead.
2484 * @return A pointer to a sockaddr holding a v4 or v6 IP address or on some
2485 * platforms a sockaddr holding a MAC address. Returns NULL if no destination
2486 * IP address was available.
2487 *
2488 * @note The best way to use this function is to pass in a pointer to the
2489 * struct sockaddr_storage for the addr parameter. This will avoid problems
2490 * with trying to shoe-horn an IPv6 address into a sockaddr that only supports
2491 * IPv4.
2492 */
2493DLLEXPORT SIMPLE_FUNCTION
2494struct sockaddr *trace_get_destination_address(const libtrace_packet_t *packet,
2495                struct sockaddr *addr);
2496
2497/** Get the destination IP address for a packet and convert it into a string
2498 * @param packet        The packet to extract the destination IP address from
2499 * @param space         A pointer to a character buffer to store the address
2500 *                      in. If NULL, static storage is used instead.
2501 * @param spacelen      The size of the buffer passed in via 'space'. Set this
2502 *                      to zero if you are going to pass in a NULL buffer.
2503 * @return A pointer to a character buffer containing the string representation
2504 * of the destination IP address. For packets where there is no suitable IP
2505 * address, the destination MAC will be returned instead. Returns NULL if no
2506 * valid address is available.
2507 *
2508 * @note Be wary of the possibility of the address being an IPv6 address - make
2509 * sure your buffer is large enough!
2510 *
2511 * New in libtrace 3.0.17.
2512 */
2513DLLEXPORT SIMPLE_FUNCTION
2514char *trace_get_destination_address_string(const libtrace_packet_t *packet,
2515                char *space, int spacelen);
2516
2517/** Parses an IP or TCP option
2518 * @param[in,out] ptr   The pointer to the current option
2519 * @param[in,out] len   The total length of all the remaining options
2520 * @param[out] type     The type of the option
2521 * @param[out] optlen   The length of the option
2522 * @param[out] data     The data of the option
2523 *
2524 * @return bool true if there is another option (and the fields are filled in)
2525 *               or false if this was the last option.
2526 *
2527 * This updates ptr to point to the next option after this one, and updates
2528 * len to be the number of bytes remaining in the options area.  Type is updated
2529 * to be the code of this option, and data points to the data of this option,
2530 * with optlen saying how many bytes there are.
2531 *
2532 * @note Beware of fragmented packets.
2533 */
2534DLLEXPORT int trace_get_next_option(unsigned char **ptr,int *len,
2535                        unsigned char *type,
2536                        unsigned char *optlen,
2537                        unsigned char **data);
2538
2539/*@}*/
2540
2541/** @name Time
2542 * These functions deal with the timestamp describing when a packet was
2543 * captured and can convert it into various formats
2544 * @{
2545 */
2546
2547/** Get the packet timestamp in the DAG time format
2548 * @param packet        The packet to extract the timestamp from
2549 *
2550 * @return a 64 bit timestamp in DAG ERF format (upper 32 bits are the seconds
2551 * past 1970-01-01, the lower 32bits are partial seconds)
2552 */
2553DLLEXPORT SIMPLE_FUNCTION
2554uint64_t trace_get_erf_timestamp(const libtrace_packet_t *packet);
2555
2556/** Get the packet timestamp as a struct timeval
2557 * @param packet        The packet to extract the timestamp from
2558 *
2559 * @return The time that this packet was captured in a struct timeval
2560 */
2561DLLEXPORT SIMPLE_FUNCTION
2562struct timeval trace_get_timeval(const libtrace_packet_t *packet);
2563
2564/** Get the packet timestamp as a struct timespec
2565 * @param packet        The packet to extract the timestamp from
2566 *
2567 * @return The time that this packet was captured in a struct timespec
2568 */
2569DLLEXPORT SIMPLE_FUNCTION
2570struct timespec trace_get_timespec(const libtrace_packet_t *packet);
2571
2572/** Get the packet timestamp in floating point seconds
2573 * @param packet        The packet to extract the timestamp from
2574 *
2575 * @return time that this packet was seen in 64-bit floating point seconds from
2576 * the UNIX epoch (1970-01-01 00:00:00 UTC).
2577 */
2578DLLEXPORT SIMPLE_FUNCTION
2579double trace_get_seconds(const libtrace_packet_t *packet);
2580
2581/** Seek within an input trace to a time specified in floating point seconds
2582 * @param trace         The input trace to seek within
2583 * @param seconds       The time to seek to, in floating point seconds
2584 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
2585 * the error that occurred.
2586 *
2587 * This will make the next packet read to be the first packet to occur at or
2588 * after the specified time.  This must be called in the configuration state
2589 * (i.e. before trace_start() or after trace_pause()).
2590 *
2591 * The time format accepted by this function is 64-bit floating point seconds
2592 * since the UNIX epoch (1970-01-01 00:00:00 UTC), i.e. the same format as
2593 * trace_get_seconds().
2594 *
2595 * @note This function may be extremely slow.
2596 */
2597DLLEXPORT int trace_seek_seconds(libtrace_t *trace, double seconds);
2598
2599/** Seek within an input trace to a time specified as a timeval
2600 * @param trace         The input trace to seek within
2601 * @param tv            The time to seek to, as a timeval
2602 *
2603 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
2604 * the error that occurred.
2605 *
2606 * This will make the next packet read to be the first packet to occur at or
2607 * after the specified time.  This must be called in the configuration state
2608 * (i.e. before trace_start() or after trace_pause()).
2609 *
2610 * @note This function may be extremely slow.
2611 */
2612DLLEXPORT int trace_seek_timeval(libtrace_t *trace, struct timeval tv);
2613
2614/** Seek within an input trace to a time specified as an ERF timestamp
2615 * @param trace         The input trace to seek within
2616 * @param ts            The time to seek to, as an ERF timestamp
2617 *
2618 * @return 0 on success, -1 if the seek fails. Use trace_perror() to determine
2619 * the error that occurred.
2620 *
2621 * This will make the next packet read to be the first packet to occur at or
2622 * after the specified time.  This must be called in the configuration state
2623 * (i.e. before trace_start() or after trace_pause()).
2624 *
2625 * The time format accepted by this function is the ERF timestamp, which is a
2626 * 64-bit value where the upper 32 bits are seconds since the UNIX epoch and
2627 * the lower 32 bits are partial seconds.
2628 *
2629 * @note This function may be extremely slow.
2630 */
2631DLLEXPORT int trace_seek_erf_timestamp(libtrace_t *trace, uint64_t ts);
2632
2633/*@}*/
2634
2635/** @name Sizes
2636 * This section deals with finding or setting the various different lengths
2637 * that a packet can have, e.g. capture lengths, wire lengths, etc.
2638 * @{
2639 */
2640/** Get the current size of the packet (in bytes), taking into account any
2641 * truncation or snapping that may have previously been performed.
2642 *
2643 * @param packet        The packet to determine the capture length for
2644 * @return The size of the packet read from the input trace, i.e. what is
2645 * actually available to libtrace at the moment.
2646 *
2647 * @note Most traces are header captures, so this value may not be the same
2648 * as the size of the packet when it was captured. Use trace_get_wire_length()
2649 * to get the original size of the packet.
2650 
2651 * @note This can (and often is) different for different packets in a trace!
2652 
2653 * @note This is sometimes called the "snaplen".
2654 *
2655 * @note The return size refers to the network-level payload of the packet and
2656 * does not include any capture framing headers. For example, an Ethernet
2657 * packet with an empty TCP packet will return sizeof(ethernet_header) +
2658 * sizeof(ip_header) + sizeof(tcp_header), but not the capture format
2659 * (pcap/erf/etc) header.
2660 */
2661DLLEXPORT SIMPLE_FUNCTION
2662size_t trace_get_capture_length(const libtrace_packet_t *packet);
2663
2664/** Get the size of the packet as it was originally seen on the wire (in bytes).
2665 * @param packet        The packet to determine the wire length for
2666 * @return The size of the packet as it was on the wire.
2667 *
2668 * @note This value may not be the same as the capture length, due to
2669 * truncation.
2670 *
2671 * @note trace_get_wire_length \em includes  the Frame Check Sequence. This is
2672 * different behaviour compared to most PCAP-based tools.
2673 *
2674 * @note The return size refers to the network-level payload of the packet and
2675 * does not include any capture framing headers. For example, an Ethernet
2676 * packet with an empty TCP packet will return sizeof(ethernet_header) +
2677 * sizeof(ip_header) + sizeof(tcp_header), but not the capture format
2678 * (pcap/erf/etc) header.
2679 */
2680DLLEXPORT SIMPLE_FUNCTION
2681size_t trace_get_wire_length(const libtrace_packet_t *packet);
2682
2683/** Get the length of the capture framing headers (in bytes).
2684 * @param packet        The packet to determine the framing length for
2685 * @return The size of the capture format header encapsulating the packet.
2686 *
2687 * @note This length corresponds to the difference between the amount of
2688 * memory required to store a captured packet and the capture length reported
2689 * by trace_capture_length()
2690 */
2691DLLEXPORT SIMPLE_FUNCTION
2692size_t trace_get_framing_length(const libtrace_packet_t *packet);
2693
2694/** Get the length of the original payload content of the packet (in bytes).
2695 * @param packet        The packet to determine the payload length for
2696 * @return The size of the packet payload (without headers). Returns 0 if
2697 * unable to calculate payload length correctly.
2698 *
2699 * This function reports the amount of data that followed the transport header
2700 * when the packet was originally captured, i.e. prior to any snapping. Best
2701 * described as the wire length minus the packet headers.
2702 *
2703 * Currently only supports some protocols and will return 0 if an unsupported
2704 * protocol header is encountered, or if one of the headers is truncated.
2705 *
2706 * @note Supports IPv4, IPv6, TCP, UDP and ICMP.
2707 */
2708DLLEXPORT SIMPLE_FUNCTION
2709size_t trace_get_payload_length(const libtrace_packet_t *packet);
2710
2711/** Truncate ("snap") the packet to the suggested length
2712 * @param packet        The packet to truncate
2713 * @param size          The new length of the packet (in bytes)
2714 *
2715 * @return The new capture length of the packet or the original capture
2716 * length of the packet if unchanged.
2717 *
2718 * This function will modify the capture length of the given packet. The wire
2719 * length will not be changed, so you can always determine what the original
2720 * packet size was, prior to the truncation.
2721 *
2722 * @note You can only use this function to decrease the capture length. Any
2723 * attempt to increase capture length will have no effect.
2724 */
2725DLLEXPORT size_t trace_set_capture_length(libtrace_packet_t *packet, size_t size);
2726
2727/*@}*/
2728
2729
2730/** Gets the link layer type for a packet
2731 * @param packet        The packet to extract the link layer type for
2732 * @return A libtrace_linktype_t describing the link layer protocol being used
2733 * by this packet.
2734 */
2735DLLEXPORT SIMPLE_FUNCTION
2736libtrace_linktype_t trace_get_link_type(const libtrace_packet_t *packet);
2737
2738/** Set the direction flag for a packet, if the capture format supports
2739 * direction tagging.
2740 *
2741 * @param packet        The packet to set the direction for
2742 * @param direction     The new direction
2743 * @returns -1 on error, or the direction that was set.
2744 *
2745 * @note Few capture formats actually support direction tagging. Most notably,
2746 * we cannot set the direction on PCAP packets.
2747 */
2748DLLEXPORT libtrace_direction_t trace_set_direction(libtrace_packet_t *packet, libtrace_direction_t direction);
2749
2750/** Get the direction flag for a packet, if it has one.
2751 * @param packet  The packet to get the direction for
2752 *
2753 * @return A value representing the direction flag, or -1 if this is not
2754 * supported by the capture format.
2755 *
2756 * The direction is defined as 0 for packets originating locally (ie, outbound)
2757 * and 1 for packets originating remotely (ie, inbound). Other values are
2758 * possible, which might be overloaded to mean special things for certain
2759 * traces, e.g. in the Waikato traces, 2 is used to represent an "Unknown"
2760 * direction.
2761 *
2762 * For DAG/ERF traces, the direction is extracted from the "Interface" bits in
2763 * the ERF header, which can range from 0 - 3.
2764 */
2765DLLEXPORT SIMPLE_FUNCTION
2766libtrace_direction_t trace_get_direction(const libtrace_packet_t *packet);
2767
2768/** @name BPF
2769 * This section deals with using Berkley Packet Filters to filter input traces
2770 * @{
2771 */
2772/** Creates a BPF filter
2773 * @param filterstring The filter string describing the BPF filter to create
2774 * @return An opaque pointer to a libtrace_filter_t object
2775 *
2776 * @note The filter is not actually compiled at this point, so no correctness
2777 * tests are performed here. trace_create_filter() will always return ok, but
2778 * if the filter is poorly constructed an error will be generated when the
2779 * filter is actually used.
2780 */
2781DLLEXPORT SIMPLE_FUNCTION
2782libtrace_filter_t *trace_create_filter(const char *filterstring);
2783
2784/** Create a BPF filter based on pre-compiled byte-code.
2785 * @param bf_insns      A pointer to the start of the byte-code
2786 * @param bf_len        The number of BPF instructions 
2787 * @return              An opaque pointer to a libtrace_filter_t object
2788 * @note                The supplied byte-code is not checked for correctness.
2789 *                      Instead, incorrect byte-code will generate an error
2790 *                      once the filter is actually used.
2791 * @author              Scott Raynel
2792 */
2793DLLEXPORT libtrace_filter_t *
2794trace_create_filter_from_bytecode(void *bf_insns, unsigned int bf_len);
2795
2796/** Apply a BPF filter to a packet
2797 * @param filter        The filter to be applied       
2798 * @param packet        The packet to be matched against the filter
2799 * @return >0 if the filter matches, 0 if it doesn't, -1 on error.
2800 *
2801 * @note Due to the way BPF filters are built, the filter is not actually
2802 * compiled until the first time trace_create_filter is called. If your filter
2803 * is incorrect, it will generate an error message and assert, exiting the
2804 * program. This behaviour may change to a more graceful handling of this error
2805 * in the future.
2806 */
2807DLLEXPORT int trace_apply_filter(libtrace_filter_t *filter,
2808                const libtrace_packet_t *packet);
2809
2810/** Destroy a BPF filter
2811 * @param filter        The filter to be destroyed
2812 *
2813 * Deallocates all the resources associated with a BPF filter.
2814 */
2815DLLEXPORT void trace_destroy_filter(libtrace_filter_t *filter);
2816/*@}*/
2817
2818/** @name Portability
2819 * This section contains functions that deal with portability issues, e.g. byte
2820 * ordering.
2821 * @{
2822 */
2823
2824/** Converts an ethernet address to a printable string
2825 * @param addr  Ethernet address in network byte order
2826 * @param buf   Buffer to store the ascii representation, or NULL to indicate
2827 * that static storage should be used.
2828 * @return buf, or if buf is NULL then a statically allocated buffer.
2829 *
2830 * This function is similar to the GNU ether_ntoa_r function, with a few
2831 * minor differences.  If NULL is passed as buf, then the function will
2832 * use an internal static buffer. If NULL isn't passed then the function
2833 * will use that buffer instead.
2834 *
2835 * The address pointers returned by trace_get_source_mac() and
2836 * trace_get_destination_mac() can be passed directly into this function.
2837 *
2838 * @note The type of addr isn't struct ether_addr as it is with ether_ntoa_r,
2839 * however it is bit compatible so that a cast will work.
2840 */
2841DLLEXPORT char *trace_ether_ntoa(const uint8_t *addr, char *buf);
2842
2843/** Convert a string to an ethernet address
2844 * @param buf   A string containing an Ethernet address in hex format
2845 * delimited with :'s.
2846 * @param addr  Buffer to store the binary representation, or NULL to indicate
2847 * that static storage should be used.
2848 * @return addr, or if addr is NULL then a statically allocated buffer.
2849 *
2850 * This function is similar to the GNU ether_aton_r function, with a few
2851 * minor differences.  If NULL is passed as addr, then the function will
2852 * use an internal static buffer. If NULL isn't passed then the function will
2853 * use that buffer instead.
2854 *
2855 * The address returned by this function will be in network byte order.
2856 *
2857 * @note the type of addr isn't struct ether_addr as it is with ether_aton_r,
2858 * however it is bit compatible so that a cast will work.
2859 */
2860DLLEXPORT uint8_t *trace_ether_aton(const char *buf, uint8_t *addr);
2861
2862/*@}*/
2863
2864/** @name Ports
2865 * This section contains functions for dealing with port numbers at the
2866 * transport layer.
2867 *
2868 * @{
2869 */
2870
2871/** An indication of which port is the "server" port for a given port pair */
2872typedef enum {
2873        USE_DEST,       /**< Destination port is the server port */
2874        USE_SOURCE      /**< Source port is the server port */
2875} serverport_t;
2876
2877/** Gets the source port for a given packet
2878 * @param packet        The packet to get the source port from
2879 * @return The source port in HOST byte order or 0 if no suitable port number
2880 * can be extracted from the packet.
2881 *
2882 * This function will return 0 if the transport protocol is known not to
2883 * use port numbers, e.g. ICMP. 0 is also returned if no transport header is
2884 * present in the packet or the transport header has been truncated such that
2885 * the port fields are not readable.
2886 *
2887 * @note If the transport protocol is not known by libtrace, the first two
2888 * bytes of the transport header will be treated as the source port field.
2889 */
2890DLLEXPORT SIMPLE_FUNCTION
2891uint16_t trace_get_source_port(const libtrace_packet_t *packet);
2892
2893/** Gets the destination port for a given packet
2894 * @param packet        The packet to get the destination port from
2895 * @return The destination port in HOST byte order or 0 if no suitable port
2896 * number can be extracted from the packet.
2897 *
2898 * This function will return 0 if the transport protocol is known not to
2899 * use port numbers, e.g. ICMP. 0 is also returned if no transport header is
2900 * present in the packet or the transport header has been truncated such that
2901 * the port fields are not readable.
2902 *
2903 * @note If the transport protocol is not known by libtrace, the third and
2904 * fourth bytes of the transport header will be treated as the destination
2905 * port field.
2906 *
2907 */
2908DLLEXPORT SIMPLE_FUNCTION
2909uint16_t trace_get_destination_port(const libtrace_packet_t *packet);
2910
2911/** Hint at which of the two provided ports is the server port.
2912 *
2913 * @param protocol      The IP layer protocol, eg 6 (tcp), 17 (udp)
2914 * @param source        The source port from the packet
2915 * @param dest          The destination port from the packet
2916 *
2917 * @return one of USE_SOURCE or USE_DEST describing on which of the two ports
2918 * is most likely to be the server port.
2919 *
2920 * @note Ports must be provided in HOST byte order!
2921 *
2922 * This function is based almost entirely on heuristics and should not be
2923 * treated as a definitive means of identifying the server port. However, it
2924 * is deterministic, so it is very handy for identifying both halves of the
2925 * same flow.
2926 */
2927DLLEXPORT SIMPLE_FUNCTION
2928int8_t trace_get_server_port(uint8_t protocol, uint16_t source, uint16_t dest);
2929
2930/*@}*/
2931
2932/** @name Wireless trace support
2933 * Functions to access wireless information from packets that have wireless
2934 * monitoring headers such as Radiotap or Prism.
2935 *
2936 * The trace_get_wireless_* functions provide an abstract interface for
2937 * retrieving information from wireless traces. They take a pointer to the
2938 * wireless monitoring header (usually found with trace_get_packet_meta()) and
2939 * the linktype of the header passed in.
2940 *
2941 * All of the trace_get_wireless_* functions return false if the requested
2942 * information was unavailable, or true if it was. The actual data is stored
2943 * in an output variable supplied by the caller. Values returned into the
2944 * output variable will always be returned in host byte order.
2945 * @{
2946 */
2947
2948
2949#ifndef ARPHRD_80211_RADIOTAP
2950/** libc doesn't define this yet, so we have to do so ourselves */
2951#define ARPHRD_80211_RADIOTAP 803
2952#endif
2953
2954/** Get the wireless Timer Synchronisation Function
2955 *
2956 * Gets the value of the timer synchronisation function for this frame, which
2957 * is a value in microseconds indicating the time that the first bit of the
2958 * MPDU was received by the MAC.
2959 *
2960 * @param linkptr The wireless meta header
2961 * @param linktype The linktype of the wireless meta header passed in
2962 * @param[out] tsft The value of the timer synchronisation function.
2963 * @return true if the field was available, false if not.
2964 */
2965DLLEXPORT bool trace_get_wireless_tsft(void *linkptr,
2966        libtrace_linktype_t linktype, uint64_t *tsft);
2967
2968/** Get the wireless data rate
2969 *
2970 * @param linkptr The wireless meta header
2971 * @param linktype The linktype of the wireless meta header passed in
2972 * @param[out] rate The data-rate of the frame in units of 500kbps
2973 * @return true if the field was available, false if not.
2974 */
2975DLLEXPORT bool trace_get_wireless_rate(void *linkptr,
2976        libtrace_linktype_t linktype, uint8_t *rate);
2977
2978/** Get the wireless channel frequency
2979 * @param linkptr The wireless meta header
2980 * @param linktype The linktype of the wireless meta header passed in
2981 * @param[out] freq The frequency in MHz of the channel the frame was
2982 * transmitted or received on.
2983 * @return true if the field was available, false if not.
2984 */
2985DLLEXPORT bool trace_get_wireless_freq(void *linkptr,
2986        libtrace_linktype_t linktype, uint16_t *freq);
2987
2988/** Get the wireless signal strength in dBm
2989 * @param linkptr The wireless meta header
2990 * @param linktype The linktype of the wireless meta header passed in
2991 * @param[out] strength The RF signal power at the antenna, in dB difference
2992 * from 1mW.
2993 * @return true if the field was available, false if not.
2994 */
2995DLLEXPORT bool trace_get_wireless_signal_strength_dbm(void *linkptr,
2996        libtrace_linktype_t linktype, int8_t *strength);
2997
2998/** Get the wireless noise strength in dBm
2999 * @param linkptr The wireless meta header
3000 * @param linktype The linktype of the wireless meta header passed in
3001 * @param[out] strength The RF noise power at the antenna, in dB difference
3002 * from 1mW.
3003 * @return true if the field was available, false if not.
3004 */
3005DLLEXPORT bool trace_get_wireless_noise_strength_dbm(void *linkptr,
3006        libtrace_linktype_t linktype, int8_t *strength);
3007
3008/** Get the wireless signal strength in dB
3009 * @param linkptr The wireless meta header
3010 * @param linktype The linktype of the wireless meta header passed in
3011 * @param[out] strength The RF signal power at the antenna, in dB difference
3012 * from a fixed reference.
3013 * @return true if the field was available, false if not.
3014 */
3015DLLEXPORT bool trace_get_wireless_signal_strength_db(void *linkptr,
3016        libtrace_linktype_t linktype, uint8_t *strength);
3017
3018/** Get the wireless noise strength in dB
3019 * @param linkptr The wireless meta header
3020 * @param linktype The linktype of the wireless meta header passed in
3021 * @param[out] strength The RF noise power at the antenna, in dB difference
3022 * from a fixed reference.
3023 * @return true if the field was available, false if not.
3024 */
3025DLLEXPORT bool trace_get_wireless_noise_strength_db(void *linkptr,
3026        libtrace_linktype_t linktype, uint8_t *strength);
3027
3028/** Get the wireless transmit attenuation
3029 * @param linkptr The wireless meta header
3030 * @param linktype The linktype of the wireless meta header passed in
3031 * @param[out] attenuation The transmit power as a unitless distance from
3032 * maximum power set at factory calibration. 0 indicates maximum transmission
3033 * power.
3034 * @return true if the field was available, false if not.
3035 */
3036DLLEXPORT bool trace_get_wireless_tx_attenuation(void *linkptr,
3037        libtrace_linktype_t linktype, uint16_t *attenuation);
3038
3039/** Get the wireless transmit attenuation in dB
3040 * @param linkptr The wireless meta header
3041 * @param linktype The linktype of the wireless meta header passed in
3042 * @param[out] attenuation The transmit power as dB difference from maximum
3043 * power set at factory calibration. 0 indicates maximum power.
3044 * @return true if the field was available, false if not.
3045 */
3046DLLEXPORT bool trace_get_wireless_tx_attenuation_db(void *linkptr,
3047        libtrace_linktype_t linktype, uint16_t *attenuation);
3048
3049/** Get the wireless transmit power in dBm
3050 * @param linkptr The wireless meta header
3051 * @param linktype The linktype of the wireless meta header passed in
3052 * @param[out] txpower The transmit power as dB from a 1mW reference. This is
3053 * the absolute power level measured at the antenna port. 
3054 * @return true if the field was available, false if not.
3055 */
3056DLLEXPORT bool trace_get_wireless_tx_power_dbm(void *linkptr,
3057                libtrace_linktype_t linktype, int8_t *txpower);
3058
3059/** Get the wireless antenna
3060 * @param linkptr The wireless meta header
3061 * @param linktype The linktype of the wireless meta header passed in
3062 * @param[out] antenna The antenna that was used to transmit or receive the
3063 * frame.
3064 * @return true if the field was available, false if not.
3065 */
3066DLLEXPORT bool trace_get_wireless_antenna(void *linkptr,
3067        libtrace_linktype_t linktype, uint8_t *antenna);
3068
3069/*@}*/
3070
3071#ifdef __cplusplus
3072} /* extern "C" */
3073#endif /* #ifdef __cplusplus */
3074#endif /* LIBTRACE_H_ */
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