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source: lib/trace.c @ 68667ee

4.0.1-hotfixescachetimestampsdevelopdpdk-ndagetsilivegetfragoffhelplibtrace4ndag_formatpfringrc-4.0.1rc-4.0.2rc-4.0.3rc-4.0.4ringdecrementfixringperformanceringtimestampfixes

Last change on this file since 68667ee was 68667ee, checked in by Perry Lorier <perry@…>, 16 years ago
Merged in a whole heap of useful features
Property mode set to `100644`
File size: 46.5 KB

Line
1	/*
2	* This file is part of libtrace
3	*
4	* Copyright (c) 2004 The University of Waikato, Hamilton, New Zealand.
5	* Authors: Daniel Lawson
6	* Perry Lorier
7	*
8	* All rights reserved.
9	*
10	* This code has been developed by the University of Waikato WAND
11	* research group. For further information please see http://www.wand.net.nz/
12	*
13	* libtrace is free software; you can redistribute it and/or modify
14	* it under the terms of the GNU General Public License as published by
15	* the Free Software Foundation; either version 2 of the License, or
16	* (at your option) any later version.
17	*
18	* libtrace is distributed in the hope that it will be useful,
19	* but WITHOUT ANY WARRANTY; without even the implied warranty of
20	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21	* GNU General Public License for more details.
22	*
23	* You should have received a copy of the GNU General Public License
24	* along with libtrace; if not, write to the Free Software
25	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26	*
27	* $Id$
28	*
29	*/
30
31
32	/** @file
33	*
34	* @brief Trace file processing library
35	*
36	* @author Daniel Lawson
37	* @author Perry Lorier
38	*
39	* @internal
40	*/
41	#define _GNU_SOURCE
42	#include "common.h"
43	#include "config.h"
44	#include <assert.h>
45	#include <errno.h>
46	#include <fcntl.h>
47	#include <netdb.h>
48	#include <stdio.h>
49	#include <stdlib.h>
50	#include <string.h>
51	#include <sys/stat.h>
52	#include <sys/types.h>
53
54	#ifdef HAVE_LIMITS_H
55	# include <limits.h>
56	#endif
57
58	#ifdef HAVE_SYS_LIMITS_H
59	# include <sys/limits.h>
60	#endif
61
62	#include <sys/socket.h>
63	#include <sys/un.h>
64	#include <sys/mman.h>
65	#include <unistd.h>
66	#include <net/ethernet.h>
67	#include <time.h>
68	#include <sys/ioctl.h>
69
70	#ifdef HAVE_STDINT_H
71	# include <stdint.h>
72	#else
73	# error "Can't find stdint.h - you need to replace this"
74	#endif
75
76	#ifdef HAVE_STDDEF_H
77	# include <stddef.h>
78	#else
79	# error "Can't find stddef.h - do you define ptrdiff_t elsewhere?"
80	#endif
81
82	#include "libtrace.h"
83	#include "fifo.h"
84
85	#if HAVE_PCAP_BPF_H
86	# include <pcap-bpf.h>
87	# ifndef HAVE_BPF
88	# define HAVE_BPF 1
89	# endif
90	#else
91	# ifdef HAVE_NET_BPF_H
92	# include <net/bpf.h>
93	# ifndef HAVE_BPF
94	# define HAVE_BPF 1
95	# endif
96	# endif
97	#endif
98
99	#if HAVE_PCAP_H
100	# include <pcap.h>
101	# ifndef HAVE_PCAP
102	# define HAVE_PCAP 1
103	# endif
104	#endif
105
106	#ifdef HAVE_ZLIB_H
107	# include <zlib.h>
108	# ifndef HAVE_ZLIB
109	# define HAVE_ZLIB 1
110	# endif
111	#endif
112
113
114	#include "wag.h"
115
116	#ifdef HAVE_DAG_API
117	# include "dagnew.h"
118	# include "dagapi.h"
119	# ifndef DAGDEVICE
120	# define DAGDEVICE 1
121	# endif
122	#else
123	# include "dagformat.h"
124	#endif
125
126
127	typedef enum {SOCKET, TRACE, STDIN, DEVICE, INTERFACE, RT } source_t;
128
129	typedef enum {ERF, PCAP, PCAPINT, DAG, RTCLIENT, WAG, WAGINT } format_t;
130
131	#if HAVE_BPF
132	/** A type encapsulating a bpf filter
133	* This type covers the compiled bpf filter, as well as the original filter
134	* string
135	*
136	*/
137	struct libtrace_filter_t {
138	struct bpf_insn *filter;
139	char * filterstring;
140	};
141	#endif
142
143	/** The information about traces that are open
144	* @internal
145	*/
146	struct libtrace_t {
147	format_t format; /*< The format that this trace is in /
148	source_t sourcetype; /*< The type (device,file, etc /
149	union {
150	/** Information about rtclients */
151	struct {
152	char *hostname;
153	short port;
154	} rt;
155	char path; /< information for local sockets /
156	char interface; /*< intormation for reading of network
157	interfaces */
158	} conn_info;
159	/** Information about the current state of the input device */
160	union {
161	int fd;
162	#if HAVE_ZLIB
163	gzFile *file;
164	#else
165	FILE *file;
166	#endif
167	#if HAVE_PCAP
168	pcap_t *pcap;
169	#endif
170	} input;
171	struct fifo_t *fifo;
172	struct {
173	void *buf;
174	unsigned bottom;
175	unsigned top;
176	unsigned diff;
177	unsigned curr;
178	unsigned offset;
179	} dag;
180	struct {
181	void *buffer;
182	int size;
183	} packet;
184	double last_ts;
185	double start_ts;
186	};
187
188	#define RP_BUFSIZE 65536
189
190	#define URI_PROTO_LINE 16
191	static int init_trace(struct libtrace_t *libtrace, char uri) {
192	char *scan = calloc(sizeof(char),URI_PROTO_LINE);
193	char *uridata = 0;
194	struct stat buf;
195
196	// parse the URI to determine what sort of event we are dealing with
197
198	// want snippet before the : to get the uri base type.
199
200	if((uridata = strchr(uri,':')) == NULL) {
201	// badly formed URI - needs a :
202	return 0;
203	}
204
205	if ((uridata - uri) > URI_PROTO_LINE) {
206	// badly formed URI - uri type is too long
207	return 0;
208	}
209	strncpy(scan,uri, (uridata - uri));
210
211	if (!strncasecmp(scan,"erf",3)) {
212	(*libtrace)->format=ERF;
213	#if HAVE_PCAP
214	} else if (!strncasecmp(scan,"pcapint",7)) {
215	(*libtrace)->format=PCAPINT;
216	} else if (!strncasecmp(scan,"pcap",4)) {
217	(*libtrace)->format=PCAP;
218	#else
219	} else if (!strncasecmp(scan,"pcap",4)) { // also catches pcapint
220	fprintf(stderr,"This version of libtrace has been compiled without PCAP support\n");
221	return 0;
222	#endif
223
224	#ifdef DAGDEVICE
225	} else if (!strncasecmp(scan,"dag",3)) {
226	(*libtrace)->format=DAG;
227	#else
228	} else if (!strncasecmp(scan,"dag",3)) {
229	fprintf(stderr,"This version of libtrace has been compiled without DAG support\n");
230	return 0;
231	#endif
232	} else if (!strncasecmp(scan,"rtclient",7)) {
233	(*libtrace)->format=RTCLIENT;
234	} else if (!strncasecmp(scan,"wagint",6)) {
235	(*libtrace)->format=WAGINT;
236	} else if (!strncasecmp(scan,"wag",3)) {
237	(*libtrace)->format=WAG;
238	} else {
239	//badly formed URI
240	return 0;
241	}
242
243	// push uridata past the delimiter
244	uridata++;
245
246	// libtrace->format now contains the type of uri
247	// libtrace->uridata contains the appropriate data for this
248
249	switch((*libtrace)->format) {
250	#if HAVE_PCAP
251	case PCAPINT:
252	#endif
253	case WAGINT:
254	/* Can have uridata of the following format
255	* eth0
256	* etc
257	*/
258	// We basically assume this is correct.
259	(*libtrace)->sourcetype = INTERFACE;
260	(*libtrace)->conn_info.path = strdup(uridata);
261	break;
262	#if HAVE_PCAP
263	case PCAP:
264	#endif
265	case ERF:
266	case WAG:
267	/*
268	* Can have uridata of the following format
269	* /path/to/socket (probably not PCAP)
270	* /path/to/file
271	* /path/to/file.gz (not PCAP)
272	* /dev/device (use PCAPINT)
273	* -
274	*/
275	if (!strncmp(uridata,"-",1)) {
276	(*libtrace)->sourcetype = STDIN;
277	} else {
278	if (stat(uridata,&buf) == -1) {
279	perror("stat");
280	return 0;
281	}
282	if (S_ISSOCK(buf.st_mode)) {
283	(*libtrace)->sourcetype = SOCKET;
284	} else if (S_ISCHR(buf.st_mode)) {
285	(*libtrace)->sourcetype = DEVICE;
286	} else {
287	(*libtrace)->sourcetype = TRACE;
288	}
289	(*libtrace)->conn_info.path = strdup(uridata);
290	}
291	break;
292	case DAG:
293	#ifdef DAGDEVICE
294	/*
295	* Can have uridata of the following format:
296	* /dev/device
297	*/
298	if (stat(uridata,&buf) == -1) {
299	perror("stat");
300	return 0;
301	}
302	if (S_ISCHR(buf.st_mode)) {
303	(*libtrace)->sourcetype = DEVICE;
304	} else {
305	fprintf(stderr,"%s isn't a valid char device, exiting\n",uridata);
306	exit(1);
307	}
308	(*libtrace)->conn_info.path = strdup(uridata);
309	#endif
310	break;
311
312	case RTCLIENT:
313	/*
314	* Can have the uridata in the format
315	* hostname
316	* hostname:port
317	*/
318	(*libtrace)->sourcetype = RT;
319	if (strlen(uridata) == 0) {
320	(*libtrace)->conn_info.rt.hostname =
321	strdup("localhost");
322	(*libtrace)->conn_info.rt.port =
323	COLLECTOR_PORT;
324	break;
325	}
326	if ((scan = strchr(uridata,':')) == NULL) {
327	(*libtrace)->conn_info.rt.hostname =
328	strdup(uridata);
329	(*libtrace)->conn_info.rt.port =
330	COLLECTOR_PORT;
331	} else {
332	(*libtrace)->conn_info.rt.hostname =
333	(char *)strndup(uridata,(scan - uridata));
334
335	(*libtrace)->conn_info.rt.port =
336	atoi(++scan);
337	}
338	break;
339	}
340
341
342	(*libtrace)->fifo = create_fifo(1048576);
343	assert( (*libtrace)->fifo);
344	//(*libtrace)->packet.buffer = 0;
345	//(*libtrace)->packet.size = 0;
346
347	return 1;
348	}
349
350	/** Create a trace file from a URI
351	*
352	* @returns opaque pointer to a libtrace_t
353	*
354	* Valid URI's are:
355	* erf:/path/to/erf/file
356	* erf:/path/to/erf/file.gz
357	* erf:/path/to/rtclient/socket
358	* erf:- (stdin)
359	* pcapint:pcapinterface (eg: pcapint:eth0)
360	* pcap:/path/to/pcap/file
361	* pcap:-
362	* rtclient:hostname
363	* rtclient:hostname:port
364	* wag:-
365	* wag:/path/to/wag/file
366	* wag:/path/to/wag/file.gz
367	* wag:/path/to/wag/socket
368	* wagint:/dev/device
369	*
370	* URIs which have yet to be implemented are:
371	* dag:/dev/dagcard
372	* pcap:/path/to/pcap/socket
373	*
374	* If an error occured when attempting to open a trace, NULL is returned
375	* and an error is output to stdout.
376	*/
377	struct libtrace_t trace_create(char uri) {
378	struct libtrace_t *libtrace = malloc(sizeof(struct libtrace_t));
379	struct hostent *he;
380	struct sockaddr_in remote;
381	struct sockaddr_un unix_sock;
382	#if HAVE_PCAP
383	char errbuf[PCAP_ERRBUF_SIZE];
384	#endif
385
386	if(init_trace(&libtrace,uri) == 0) {
387	return 0;
388	}
389
390	switch(libtrace->sourcetype) {
391	case RT:
392	if ((he=gethostbyname(libtrace->conn_info.rt.hostname)) == NULL) {
393	perror("gethostbyname");
394	return 0;
395	}
396	if ((libtrace->input.fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
397	perror("socket");
398	return 0;
399	}
400
401	remote.sin_family = AF_INET;
402	remote.sin_port = htons(libtrace->conn_info.rt.port);
403	remote.sin_addr = ((struct in_addr )he->h_addr);
404	bzero(&(remote.sin_zero), 8);
405
406	if (connect(libtrace->input.fd, (struct sockaddr *)&remote,
407	sizeof(struct sockaddr)) == -1) {
408	perror("connect (inet)");
409	return 0;
410	}
411	break;
412	case TRACE:
413	#if HAVE_PCAP
414	if (libtrace->format == PCAP) {
415	if ((libtrace->input.pcap = pcap_open_offline(libtrace->conn_info.path, errbuf)) == NULL) {
416	fprintf(stderr,"%s\n",errbuf);
417	return 0;
418	}
419	} else {
420	#else
421	{
422	#endif
423	#if HAVE_ZLIB
424	libtrace->input.file = gzopen(libtrace->conn_info.path, "r");
425	#else
426	libtrace->input.file = fopen(libtrace->conn_info.path, "r");
427	#endif
428	}
429	break;
430	case STDIN:
431	#if HAVE_PCAP
432	if (libtrace->format == PCAP) {
433	libtrace->input.pcap = pcap_open_offline("-",errbuf);
434	} else {
435	#else
436	{
437	#endif
438	#if HAVE_ZLIB
439	libtrace->input.file = gzdopen(STDIN, "r");
440	#else
441	libtrace->input.file = stdin;
442	#endif
443	}
444	break;
445	case SOCKET:
446	/* Pcap doesn't work */
447	if (libtrace->format != PCAP) {
448	if ((libtrace->input.fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
449	perror("socket");
450	return 0;
451	}
452	unix_sock.sun_family = AF_UNIX;
453	bzero(unix_sock.sun_path,108);
454	snprintf(unix_sock.sun_path,108,"%s",libtrace->conn_info.path);
455
456	if (connect(libtrace->input.fd, (struct sockaddr *)&unix_sock,
457	sizeof(struct sockaddr)) == -1) {
458	perror("connect (unix)");
459	return 0;
460	}
461	}
462	break;
463	case DEVICE:
464	case INTERFACE:
465	switch (libtrace->format) {
466	#if HAVE_PCAP
467	case PCAPINT:
468	case PCAP:
469	libtrace->input.pcap = pcap_open_live(
470	libtrace->conn_info.path,
471	4096,
472	1,
473	0,
474	errbuf);
475	break;
476	#endif
477	case WAGINT:
478	case WAG:
479	libtrace->input.fd = open(
480	libtrace->conn_info.path,
481	O_RDONLY);
482	break;
483	#ifdef DAGDEVICE
484	case DAG:
485	if((libtrace->input.fd = dag_open(libtrace->conn_info.path)) < 0) {
486	fprintf(stderr,"Cannot open DAG %s: %m\n", libtrace->conn_info.path,errno);
487	exit(0);
488	}
489	if((libtrace->dag.buf = dag_mmap(libtrace->input.fd)) == MAP_FAILED) {
490	fprintf(stderr,"Cannot mmap DAG %s: %m\n", libtrace->conn_info.path,errno);
491	exit(0);
492	}
493	if(dag_start(libtrace->input.fd) < 0) {
494	fprintf(stderr,"Cannot start DAG %s: %m\n", libtrace->conn_info.path,errno);
495	exit(0);
496	}
497	break;
498	#endif
499	default:
500	fprintf(stderr,"Unknown format trace, hoping I can just read\n");
501	break;
502
503	}
504	break;
505	default:
506	fprintf(stderr,"Unsupported source type for libtrace, terminating (%i)\n",libtrace->sourcetype);
507	exit(0);
508
509	}
510	return libtrace;
511	}
512
513	/** Close a trace file, freeing up any resources it may have been using
514	*
515	*/
516	void trace_destroy(struct libtrace_t *libtrace) {
517	assert(libtrace);
518	#if HAVE_PCAP
519	if (libtrace->format == PCAP \|\| libtrace->format == PCAPINT) {
520	pcap_close(libtrace->input.pcap);
521	#else
522	if (0) {
523	#endif
524	} else if (libtrace->sourcetype == SOCKET \|\| libtrace->sourcetype == RT) {
525	close(libtrace->input.fd);
526	#ifdef DAGDEVICE
527	} else if (libtrace->format == DAG) {
528	dag_stop(libtrace->input.fd);
529	#endif
530	} else {
531	#if HAVE_ZLIB
532	gzclose(libtrace->input.file);
533	#else
534	fclose(libtrace->input.file);
535	#endif
536	}
537	// need to free things!
538	destroy_fifo(libtrace->fifo);
539	free(libtrace);
540	}
541
542	static int trace_read(struct libtrace_t libtrace, void buffer, size_t len) {
543	int numbytes;
544	static short lctr = 0;
545	struct dag_record_t *recptr = 0;
546	int rlen;
547	assert(libtrace);
548	assert(len >= 0);
549
550	if (buffer == 0)
551	buffer = malloc(len);
552
553	while(1) {
554	switch(libtrace->sourcetype) {
555	case SOCKET:
556	case RT:
557
558	#ifndef MSG_NOSIGNAL
559	#define MSG_NOSIGNAL 0
560	#endif
561	// read from the network
562	if ((numbytes=recv(libtrace->input.fd,
563	buffer,
564	len,
565	MSG_NOSIGNAL)) == -1) {
566	if (errno == EINTR) {
567	// ignore EINTR in case
568	// a caller is using signals
569	continue;
570	}
571	perror("recv");
572	return -1;
573	}
574	break;
575	case DEVICE:
576	switch(libtrace->format) {
577	#ifdef DAGDEVICE
578	case DAG:
579
580	libtrace->dag.bottom = libtrace->dag.top;
581	libtrace->dag.top = dag_offset(
582	libtrace->input.fd,
583	&(libtrace->dag.bottom),
584	0);
585	libtrace->dag.diff = libtrace->dag.top -
586	libtrace->dag.bottom;
587
588	numbytes=libtrace->dag.diff;
589	libtrace->dag.offset = 0;
590
591	break;
592	#endif
593	default:
594	if ((numbytes=read(libtrace->input.fd,
595	buffer,
596	len)) == -1) {
597	perror("read");
598	return -1;
599	}
600	}
601	break;
602	default:
603	#if HAVE_ZLIB
604	if ((numbytes=gzread(libtrace->input.file,
605	buffer,
606	len)) == -1) {
607	perror("gzread");
608	return -1;
609	}
610	#else
611	if ((numbytes=fread(buffer,len,1,libtrace->input.file)) == 0 ) {
612	if(feof(libtrace->input.file)) {
613	return 0;
614	}
615	if(ferror(libtrace->input.file)) {
616	perror("fread");
617	return -1;
618	}
619	return 0;
620	}
621	#endif
622	}
623	break;
624	}
625	return numbytes;
626
627	}
628
629	/** Read one packet from the trace into buffer
630	*
631	* @param libtrace the libtrace opaque pointer
632	* @param packet the packet opaque pointer
633	* @returns false if it failed to read a packet
634	*
635	*/
636	int trace_read_packet(struct libtrace_t libtrace, struct libtrace_packet_t packet) {
637	int numbytes;
638	int size;
639	char buf[RP_BUFSIZE];
640	#if HAVE_PCAP
641	struct pcap_pkthdr pcaphdr;
642	const u_char *pcappkt;
643	#endif
644	dag_record_t *erfptr;
645	int read_required = 0;
646
647	void *buffer = 0;
648	if (!libtrace) {
649	fprintf(stderr,"Oi! You called trace_read_packet() with a NULL libtrace parameter!\n");
650	}
651	assert(libtrace);
652	assert(packet);
653
654	/* Store the trace we are reading from into the packet opaque
655	* structure */
656	packet->trace = libtrace;
657
658	buffer = packet->buffer;
659	#if HAVE_PCAP
660	/* PCAP gives us it's own per-packet interface. Let's use it */
661	if (libtrace->format == PCAP \|\| libtrace->format == PCAPINT) {
662	if ((pcappkt = pcap_next(libtrace->input.pcap, &pcaphdr)) == NULL) {
663	return -1;
664	}
665	memcpy(buffer,&pcaphdr,sizeof(struct pcap_pkthdr));
666	memcpy(buffer + sizeof(struct pcap_pkthdr),pcappkt,pcaphdr.len);
667	numbytes = pcaphdr.len;
668
669	packet->size = numbytes + sizeof(struct pcap_pkthdr);
670	return numbytes;
671	}
672	#endif
673
674	/* If we're reading from an ERF input, it's an offline trace. We can make some assumptions */
675	if (libtrace->format == ERF) {
676	void *buffer2 = buffer;
677	int rlen;
678	// read in the trace header
679	if ((numbytes=gzread(libtrace->input.file,
680	buffer,
681	dag_record_size)) == -1) {
682	perror("gzread");
683	return -1;
684	}
685	if (numbytes == 0) {
686	return 0;
687	}
688	rlen = ntohs(((dag_record_t *)buffer)->rlen);
689	size = rlen - dag_record_size;
690	assert(size < LIBTRACE_PACKET_BUFSIZE);
691	buffer2 = buffer + dag_record_size;
692
693	// read in the rest of the packet
694	if ((numbytes=gzread(libtrace->input.file,
695	buffer2,
696	size)) == -1) {
697	perror("gzread");
698	return -1;
699	}
700	//if ((numbytes + dag_record_size) != rlen) {
701	// printf("read %d wanted %d\n",numbytes +dag_record_size, rlen);
702	//}
703	packet->size = rlen;
704
705	return rlen;
706	}
707
708	#ifdef DAGDEVICE
709	if (libtrace->format == DAG) {
710	if (libtrace->dag.diff == 0) {
711	if ((numbytes = trace_read(libtrace,buf,RP_BUFSIZE)) <= 0)
712	return numbytes;
713	}
714	// DAG always gives us whole packets.
715
716	erfptr = (dag_record_t ) ((void )libtrace->dag.buf + (libtrace->dag.bottom + libtrace->dag.offset));
717	size = ntohs(erfptr->rlen);
718
719	if ( size > LIBTRACE_PACKET_BUFSIZE) {
720	printf("%d\n",size);
721	assert( size < LIBTRACE_PACKET_BUFSIZE);
722	}
723
724	// have to copy it out of the memory hole at this stage:
725	memcpy(packet->buffer, erfptr, size);
726
727	packet->size = size;
728	libtrace->dag.offset += size;
729	libtrace->dag.diff -= size;
730
731	assert(libtrace->dag.diff >= 0);
732	//assert(libtrace->dag.offset <= libtrace->dag.top);
733	return (size);
734
735	}
736	#endif
737	do {
738	if (fifo_out_available(libtrace->fifo) == 0 \|\| read_required) {
739	if ((numbytes = trace_read(libtrace,buf,RP_BUFSIZE))<=0){
740	return numbytes;
741	}
742	assert(libtrace->fifo);
743	fifo_write(libtrace->fifo,buf,numbytes);
744
745	read_required = 0;
746	}
747
748	switch (libtrace->format) {
749	case RTCLIENT:
750	// only do this if we're reading from the RT interface
751	if (fifo_out_read(libtrace->fifo, &packet->status, sizeof(int)) == 0) {
752	read_required = 1;
753	continue;
754	}
755
756	fifo_out_update(libtrace->fifo,sizeof(int));
757
758	/* FALL THRU */
759	case ERF:
760	//case DAG:
761	// read in the erf header
762	if ((numbytes = fifo_out_read(libtrace->fifo, buffer, sizeof(dag_record_t))) == 0) {
763	fifo_out_reset(libtrace->fifo);
764	read_required = 1;
765	continue;
766	}
767
768	size = ntohs(((dag_record_t *)buffer)->rlen);
769	break;
770	case WAG:
771	if ((numbytes = fifo_out_read(libtrace->fifo,
772	&size,
773	sizeof(size)))
774	== 0) {
775	fifo_out_reset(libtrace->fifo);
776	read_required = 1;
777	continue;
778	}
779	size*=4;
780	break;
781	default:
782	fprintf(stderr,"Unknown type in _read()\n");
783	assert(0);
784	}
785
786	assert(size < LIBTRACE_PACKET_BUFSIZE);
787
788	// read in the full packet
789	if ((numbytes = fifo_out_read(libtrace->fifo, buffer, size)) == 0) {
790	fifo_out_reset(libtrace->fifo);
791	read_required = 1;
792	continue;
793	}
794
795	// got in our whole packet, so...
796	fifo_out_update(libtrace->fifo,size);
797
798	if (libtrace->sourcetype == SOCKET \|\| libtrace->sourcetype == RT) {
799	fifo_ack_update(libtrace->fifo,size + sizeof(int));
800	} else {
801	fifo_ack_update(libtrace->fifo,size);
802	}
803
804	packet->size = numbytes;
805	return numbytes;
806
807	} while (1);
808	}
809
810
811	/** get a pointer to the link layer
812	* @param packet a pointer to a libtrace_packet structure
813	*
814	* @returns a pointer to the link layer, or NULL if there is no link layer
815	* you should call trace_get_link_type() to find out what type of link layer this is
816	*/
817	void trace_get_link(struct libtrace_packet_t packet) {
818	void *ethptr = 0;
819
820	struct wag_event_t event = (struct wag_event_t )packet->buffer;
821	struct wag_data_event_t *data_event;
822
823
824	switch(packet->trace->format) {
825	case ERF:
826	case DAG:
827	case RTCLIENT:
828	if (trace_get_link_type(packet)==TRACE_TYPE_ETH)
829	ethptr = ((uint8_t *)packet->buffer +
830	dag_record_size + 2);
831	else
832	ethptr = ((uint8_t *)packet->buffer +
833	dag_record_size + 2);
834	break;
835	#if HAVE_PCAP
836	case PCAPINT:
837	case PCAP:
838	ethptr = (struct ether_header *)(packet->buffer + sizeof(struct pcap_pkthdr));
839	break;
840	#endif
841	case WAGINT:
842	case WAG:
843	switch (event->type) {
844	case 0x0:
845	data_event = (void*)&(event->payload);
846	return data_event->data;
847	default:
848	fprintf(stderr,"Unknown WAG Event (0x%08x)\n",event->type);
849	return NULL;
850	}
851
852	default:
853	fprintf(stderr,"Dunno this trace format\n");
854	assert(0);
855	}
856	return ethptr;
857	}
858
859	/** get a pointer to the IP header (if any)
860	* @param packet a pointer to a libtrace_packet structure
861	*
862	* @returns a pointer to the IP header, or NULL if there is not an IP packet
863	*/
864	struct libtrace_ip trace_get_ip(struct libtrace_packet_t packet) {
865	struct libtrace_ip *ipptr = 0;
866
867	switch(trace_get_link_type(packet)) {
868	case TRACE_TYPE_80211:
869	{
870
871	struct ieee_802_11_header *wifi = trace_get_link(packet);
872
873	// Data packet?
874	if (wifi->type != 2) {
875	ipptr = NULL;
876	}
877	else {
878	struct ieee_802_11_payload eth = (void)wifi->data;
879	if (eth->type != 0x0008) {
880	ipptr=NULL;
881	} else {
882	ipptr=(void*)eth->data;
883	}
884	}
885	}
886	break;
887	case TRACE_TYPE_ETH:
888	{
889	struct ether_header *eth =
890	trace_get_link(packet);
891	if (ntohs(eth->ether_type)!=0x0800) {
892	ipptr = NULL;
893	}
894	else {
895	ipptr = ((void *)eth) + 14;
896	}
897	break;
898	}
899	case TRACE_TYPE_ATM:
900	{
901	struct atm_rec *atm =
902	trace_get_link(packet);
903	// TODO: Find out what ATM does, and return
904	// NULL for non IP data
905	// Presumably it uses the normal stuff
906	ipptr = (void*)&atm->pload;
907	break;
908	}
909	default:
910	fprintf(stderr,"Don't understand link layer type %i in trace_get_ip()\n",
911	trace_get_link_type(packet));
912	ipptr=NULL;
913	break;
914	}
915
916	return ipptr;
917	}
918
919	#define SW_IP_OFFMASK 0xff1f
920
921	/** get a pointer to the TCP header (if any)
922	* @param packet a pointer to a libtrace_packet structure
923	*
924	* @returns a pointer to the TCP header, or NULL if there is not a TCP packet
925	*/
926	struct libtrace_tcp trace_get_tcp(struct libtrace_packet_t packet) {
927	struct libtrace_tcp *tcpptr = 0;
928	struct libtrace_ip *ipptr = 0;
929
930	if(!(ipptr = trace_get_ip(packet))) {
931	return 0;
932	}
933	if ((ipptr->ip_p == 6) && ((ipptr->ip_off & SW_IP_OFFMASK) == 0)) {
934	tcpptr = (struct libtrace_tcp )((ptrdiff_t)ipptr + (ipptr->ip_hl 4));
935	}
936	return tcpptr;
937	}
938
939	/** get a pointer to the TCP header (if any) given a pointer to the IP header
940	* @param ip The IP header
941	* @param[out] skipped An output variable of the number of bytes skipped
942	*
943	* @returns a pointer to the TCP header, or NULL if this is not a TCP packet
944	*
945	* Skipped can be NULL, in which case it will be ignored by the program.
946	*/
947	struct libtrace_tcp get_tcp_from_ip(struct libtrace_ip ip, int *skipped)
948	{
949	#define SW_IP_OFFMASK 0xff1f
950	struct libtrace_tcp *tcpptr = 0;
951
952	if ((ip->ip_p == 6) && ((ip->ip_off & SW_IP_OFFMASK) == 0)) {
953	tcpptr = (struct libtrace_tcp )((ptrdiff_t)ip+ (ip->ip_hl 4));
954	}
955
956	if (skipped)
957	skipped=(ip->ip_hl4);
958
959	return tcpptr;
960	}
961
962	/** get a pointer to the UDP header (if any)
963	* @param packet a pointer to a libtrace_packet structure
964	*
965	* @returns a pointer to the UDP header, or NULL if this is not a UDP packet
966	*/
967	struct libtrace_udp trace_get_udp(struct libtrace_packet_t packet) {
968	struct libtrace_udp *udpptr = 0;
969	struct libtrace_ip *ipptr = 0;
970
971	if(!(ipptr = trace_get_ip(packet))) {
972	return 0;
973	}
974	if ((ipptr->ip_p == 17) && ((ipptr->ip_off & SW_IP_OFFMASK) == 0)) {
975	udpptr = (struct libtrace_udp )((ptrdiff_t)ipptr + (ipptr->ip_hl 4));
976	}
977
978	return udpptr;
979	}
980
981	/** get a pointer to the UDP header (if any) given a pointer to the IP header
982	* @param ip The IP header
983	* @param[out] skipped An output variable of the number of bytes skipped
984	*
985	* @returns a pointer to the UDP header, or NULL if this is not a UDP packet
986	*
987	* Skipped can be NULL, in which case it will be ignored by the program.
988	*/
989	struct libtrace_udp get_udp_from_ip(struct libtrace_ip ip, int *skipped)
990	{
991	struct libtrace_udp *udpptr = 0;
992
993	if ((ip->ip_p == 6) && ((ip->ip_off & SW_IP_OFFMASK) == 0)) {
994	udpptr = (struct libtrace_udp )((ptrdiff_t)ip+ (ip->ip_hl 4));
995	}
996
997	if (skipped)
998	skipped=(ip->ip_hl4);
999
1000	return udpptr;
1001	}
1002
1003
1004	/** get a pointer to the ICMP header (if any)
1005	* @param packet a pointer to a libtrace_packet structure
1006	*
1007	* @returns a pointer to the ICMP header, or NULL if this is not a ICMP packet
1008	*/
1009	struct libtrace_icmp trace_get_icmp(struct libtrace_packet_t packet) {
1010	struct libtrace_icmp *icmpptr = 0;
1011	struct libtrace_ip *ipptr = 0;
1012
1013	if(!(ipptr = trace_get_ip(packet))) {
1014	return 0;
1015	}
1016	if ((ipptr->ip_p == 1)&& ((ipptr->ip_off & SW_IP_OFFMASK) == 0 )){
1017	icmpptr = (struct libtrace_icmp )((ptrdiff_t)ipptr + (ipptr->ip_hl 4));
1018	}
1019	return icmpptr;
1020	}
1021
1022	/** get a pointer to the ICMP header (if any) given a pointer to the IP header
1023	* @param ip The IP header
1024	* @param[out] skipped An output variable of the number of bytes skipped
1025	*
1026	* @returns a pointer to the ICMP header, or NULL if this is not a ICMP packet
1027	*
1028	* Skipped can be NULL, in which case it will be ignored by the program.
1029	*/
1030	struct libtrace_icmp get_icmp_from_ip(struct libtrace_ip ip, int *skipped)
1031	{
1032	struct libtrace_icmp *icmpptr = 0;
1033
1034	if ((ip->ip_p == 6) && ((ip->ip_off & SW_IP_OFFMASK) == 0)) {
1035	icmpptr = (struct libtrace_icmp )((ptrdiff_t)ip+ (ip->ip_hl 4));
1036	}
1037
1038	if (skipped)
1039	skipped=(ip->ip_hl4);
1040
1041	return icmpptr;
1042	}
1043	/** parse an ip or tcp option
1044	* @param[in,out] ptr the pointer to the current option
1045	* @param[in,out] len the length of the remaining buffer
1046	* @param[out] type the type of the option
1047	* @param[out] optlen the length of the option
1048	* @param[out] data the data of the option
1049	*
1050	* @returns bool true if there is another option (and the fields are filled in)
1051	* or false if this was the last option.
1052	*
1053	* This updates ptr to point to the next option after this one, and updates
1054	* len to be the number of bytes remaining in the options area. Type is updated
1055	* to be the code of this option, and data points to the data of this option,
1056	* with optlen saying how many bytes there are.
1057	*
1058	* @note Beware of fragmented packets.
1059	* @author Perry Lorier
1060	*/
1061	int trace_get_next_option(unsigned char *ptr,int len,
1062	unsigned char *type,
1063	unsigned char *optlen,
1064	unsigned char **data)
1065	{
1066	if (*len<=0)
1067	return 0;
1068	type=*ptr;
1069	switch(*type) {
1070	case 0: /* End of options */
1071	return 0;
1072	case 1: /* Pad */
1073	(*ptr)++;
1074	(*len)--;
1075	return 1;
1076	default:
1077	optlen = (*ptr+1);
1078	if (*optlen<2)
1079	return 0; // I have no idea wtf is going on
1080	// with these packets
1081	(len)-=optlen;
1082	(data)=(ptr+2);
1083	(ptr)+=optlen;
1084	if (*len<0)
1085	return 0;
1086	return 1;
1087	}
1088	assert(0);
1089	}
1090
1091
1092	/** Get the current time in DAG time format
1093	* @param packet a pointer to a libtrace_packet structure
1094	* @returns a 64 bit timestamp in DAG ERF format (upper 32 bits are the seconds
1095	* past 1970-01-01, the lower 32bits are partial seconds)
1096	* @author Daniel Lawson
1097	*/
1098	uint64_t trace_get_erf_timestamp(struct libtrace_packet_t *packet) {
1099	uint64_t timestamp = 0;
1100	dag_record_t *erfptr = 0;
1101	struct pcap_pkthdr *pcapptr = 0;
1102	struct wag_event_t *wagptr = 0;
1103	switch (packet->trace->format) {
1104	case DAG:
1105	case ERF:
1106	case RTCLIENT:
1107	erfptr = (dag_record_t *)packet->buffer;
1108	timestamp = erfptr->ts;
1109	break;
1110	#if HAVE_PCAP
1111	case PCAPINT:
1112	case PCAP:
1113	pcapptr = (struct pcap_pkthdr *)packet->buffer;
1114	timestamp = ((((uint64_t)pcapptr->ts.tv_sec) << 32) + \
1115	(pcapptr->ts.tv_usec*UINT_MAX/1000000));
1116	break;
1117	#endif
1118	case WAGINT:
1119	case WAG:
1120	wagptr = (struct wag_event_t *)packet->buffer;
1121	timestamp = wagptr->timestamp_lo;
1122	timestamp \|= (uint64_t)wagptr->timestamp_hi<<32;
1123	timestamp = ((timestamp%44000000)*(UINT_MAX/44000000))
1124	\| ((timestamp/44000000)<<32);
1125	break;
1126	default:
1127	fprintf(stderr,"Unknown format in trace_get_erf_timestamp\n");
1128	timestamp = 0;
1129	}
1130	return timestamp;
1131	}
1132
1133	/** Get the current time in struct timeval
1134	* @param packet a pointer to a libtrace_packet structure
1135	*
1136	* @returns time that this packet was seen in a struct timeval
1137	* @author Daniel Lawson
1138	* @author Perry Lorier
1139	*/
1140	struct timeval trace_get_timeval(struct libtrace_packet_t *packet) {
1141	struct timeval tv;
1142	#if HAVE_PCAP
1143	struct pcap_pkthdr *pcapptr = 0;
1144	#endif
1145	uint64_t ts;
1146	//uint32_t seconds;
1147	switch (packet->trace->format) {
1148	#if HAVE_PCAP
1149	case PCAPINT:
1150	case PCAP:
1151	pcapptr = (struct pcap_pkthdr *)packet->buffer;
1152	tv = pcapptr->ts;
1153	break;
1154	#endif
1155	case WAGINT:
1156	case WAG:
1157	case DAG:
1158	case ERF:
1159	case RTCLIENT:
1160	default:
1161	// FIXME: This isn't portable to big-endian machines
1162	ts = trace_get_erf_timestamp(packet);
1163	tv.tv_sec = ts >> 32;
1164	ts = (1000000 * (ts & 0xffffffffULL));
1165	ts += (ts & 0x80000000ULL) << 1;
1166	tv.tv_usec = ts >> 32;
1167	if (tv.tv_usec >= 1000000) {
1168	tv.tv_usec -= 1000000;
1169	tv.tv_sec += 1;
1170	}
1171	break;
1172	}
1173	return tv;
1174	}
1175
1176	/** Get the current time in floating point seconds
1177	* @param packet a pointer to a libtrace_packet structure
1178	* @returns time that this packet was seen in 64bit floating point seconds
1179	* @author Perry Lorier
1180	*/
1181	double trace_get_seconds(struct libtrace_packet_t *packet) {
1182	uint64_t ts;
1183	ts = trace_get_erf_timestamp(packet);
1184	return (ts>>32) + ((ts & UINT_MAX)*1.0 / UINT_MAX);
1185	}
1186
1187	/** Get the size of the packet in the trace
1188	* @param packet the packet opaque pointer
1189	* @returns the size of the packet in the trace
1190	* @author Perry Lorier
1191	* @note Due to this being a header capture, or anonymisation, this may not
1192	* be the same size as the original packet. See trace_get_wire_length() for the
1193	* original size of the packet.
1194	* @note This can (and often is) different for different packets in a trace!
1195	* @par
1196	* This is sometimes called the "snaplen".
1197	*/
1198	int trace_get_capture_length(struct libtrace_packet_t *packet) {
1199	dag_record_t *erfptr = 0;
1200	#if HAVE_PCAP
1201	struct pcap_pkthdr *pcapptr = 0;
1202	#endif
1203	struct wag_event_t *wag_event;
1204	switch (packet->trace->format) {
1205	case DAG:
1206	case ERF:
1207	case RTCLIENT:
1208	erfptr = (dag_record_t *)packet->buffer;
1209	return ntohs(erfptr->rlen);
1210	#if HAVE_PCAP
1211	case PCAPINT:
1212	case PCAP:
1213	pcapptr = (struct pcap_pkthdr *)packet->buffer;
1214	//return ntohs(pcapptr->caplen);
1215	return pcapptr->caplen;
1216	#endif
1217	case WAGINT:
1218	case WAG:
1219	wag_event = (struct wag_event_t *)packet->buffer;
1220	switch(wag_event->type) {
1221	case 0:
1222	return wag_event->length*4-(
1223	sizeof(struct wag_event_t)+
1224	sizeof(struct wag_data_event_t)
1225	);
1226	default:
1227	assert(0);
1228	}
1229	default:
1230	assert(0);
1231	}
1232	return -1;
1233	}
1234
1235	/** Get the size of the packet as it was seen on the wire.
1236	* @param packet a pointer to a libtrace_packet structure
1237	*
1238	* @returns the size of the packet as it was on the wire.
1239	* @author Perry Lorier
1240	* @author Daniel Lawson
1241	* @note Due to the trace being a header capture, or anonymisation this may
1242	* not be the same as the Capture Len.
1243	*/
1244	int trace_get_wire_length(struct libtrace_packet_t *packet){
1245	dag_record_t *erfptr = 0;
1246	#if HAVE_PCAP
1247	struct pcap_pkthdr *pcapptr = 0;
1248	#endif
1249	struct wag_event_t *wag_event = 0;
1250	switch (packet->trace->format) {
1251	case DAG:
1252	case ERF:
1253	case RTCLIENT:
1254	erfptr = (dag_record_t *)packet->buffer;
1255	return ntohs(erfptr->wlen);
1256	break;
1257	#if HAVE_PCAP
1258	case PCAPINT:
1259	case PCAP:
1260	pcapptr = (struct pcap_pkthdr *)packet->buffer;
1261	return ntohs(pcapptr->len);
1262	break;
1263	#endif
1264	case WAGINT:
1265	case WAG:
1266	wag_event = (struct wag_event_t *)packet->buffer;
1267	switch(wag_event->type) {
1268	case 0:
1269	return ((struct wag_data_event_t *)(&wag_event->payload))->frame_length;
1270	default:
1271	assert(0);
1272	}
1273	}
1274	return -1;
1275
1276	}
1277
1278	/** Get the type of the link layer
1279	* @param packet a pointer to a libtrace_packet structure
1280	* @returns libtrace_linktype_t
1281	* @author Perry Lorier
1282	* @author Daniel Lawson
1283	*/
1284	libtrace_linktype_t trace_get_link_type(struct libtrace_packet_t *packet ) {
1285	dag_record_t *erfptr = 0;
1286	#if HAVE_PCAP
1287	struct pcap_pkthdr *pcapptr = 0;
1288	#endif
1289	int linktype = 0;
1290	switch (packet->trace->format) {
1291	case DAG:
1292	case ERF:
1293	case RTCLIENT:
1294	erfptr = (dag_record_t *)packet->buffer;
1295	switch (erfptr->type) {
1296	case TYPE_ETH: return TRACE_TYPE_ETH;
1297	case TYPE_ATM: return TRACE_TYPE_ATM;
1298	default: assert(0);
1299	}
1300	return erfptr->type;
1301
1302	break;
1303	#if HAVE_PCAP
1304	case PCAPINT:
1305	case PCAP:
1306	pcapptr = (struct pcap_pkthdr *)packet->buffer;
1307	linktype = pcap_datalink(packet->trace->input.pcap);
1308	switch (linktype) {
1309	case 1:
1310	return TRACE_TYPE_ETH;
1311	case 11:
1312	return TRACE_TYPE_ATM;
1313	case DLT_IEEE802_11:
1314	return TRACE_TYPE_80211;
1315	}
1316	break;
1317	#endif
1318	case WAGINT:
1319	case WAG:
1320	return TRACE_TYPE_80211;
1321	}
1322	return -1;
1323	}
1324
1325	/** Get the source MAC addres
1326	* @param packet a pointer to a libtrace_packet structure
1327	* @returns a pointer to the source mac, (or NULL if there is no source MAC)
1328	* @author Perry Lorier
1329	*/
1330	uint8_t trace_get_source_mac(struct libtrace_packet_t packet) {
1331	void *link = trace_get_link(packet);
1332	struct ieee_802_11_header *wifi = link;
1333	struct ether_header *ethptr = link;
1334	if (!link)
1335	return NULL;
1336	switch (trace_get_link_type(packet)) {
1337	case TRACE_TYPE_80211:
1338	return (uint8_t*)&wifi->mac2;
1339	case TRACE_TYPE_ETH:
1340	return (uint8_t*)&ethptr->ether_shost;
1341	default:
1342	fprintf(stderr,"Not implemented\n");
1343	assert(0);
1344	}
1345	}
1346
1347	/** Get the destination MAC addres
1348	* @param packet a libtrace_packet pointer
1349	* @returns a pointer to the destination mac, (or NULL if there is no
1350	* destination MAC)
1351	* @author Perry Lorier
1352	*/
1353	uint8_t trace_get_destination_mac(struct libtrace_packet_t packet) {
1354	void *link = trace_get_link(packet);
1355	struct ieee_802_11_header *wifi = link;
1356	struct ether_header *ethptr = link;
1357	if (!link)
1358	return NULL;
1359	switch (trace_get_link_type(packet)) {
1360	case TRACE_TYPE_80211:
1361	return (uint8_t*)&wifi->mac1;
1362	case TRACE_TYPE_ETH:
1363	return (uint8_t*)&ethptr->ether_dhost;
1364	default:
1365	fprintf(stderr,"Not implemented\n");
1366	assert(0);
1367	}
1368	}
1369
1370
1371	/** process a libtrace event
1372	* @param trace the libtrace opaque pointer
1373	* @param packet the libtrace_packet opaque pointer
1374	* @returns
1375	* TRACE_EVENT_IOWAIT Waiting on I/O on fd
1376	* TRACE_EVENT_SLEEP Next event in seconds
1377	* TRACE_EVENT_PACKET Packet arrived in buffer with size size
1378	* FIXME currently keeps a copy of the packet inside the trace pointer,
1379	* which in turn is stored inside the new packet object...
1380	* @author Perry Lorier
1381	*/
1382	struct libtrace_eventobj_t trace_event(struct libtrace_t *trace,
1383	struct libtrace_packet_t *packet) {
1384	struct libtrace_eventobj_t event;
1385
1386	if (!trace) {
1387	fprintf(stderr,"You called trace_event() with a NULL trace object!\n");
1388	}
1389	assert(trace);
1390	assert(packet);
1391
1392	/* Store the trace we are reading from into the packet opaque
1393	* structure */
1394	packet->trace = trace;
1395
1396	/* Is there a packet ready? */
1397	switch (trace->sourcetype) {
1398	#if HAVE_PCAP
1399	case INTERFACE:
1400	{
1401	int data;
1402	event.fd = pcap_fileno(trace->input.pcap);
1403	if(ioctl(event.fd,FIONREAD,&data)==-1){
1404	perror("ioctl(FIONREAD)");
1405	}
1406	if (data>0) {
1407	trace_read_packet(trace,packet);
1408	event.type = TRACE_EVENT_PACKET;
1409	return event;
1410	}
1411	event.type = TRACE_EVENT_IOWAIT;
1412	return event;
1413	}
1414	#endif
1415	case SOCKET:
1416	case DEVICE:
1417	case RT:
1418	{
1419	int data;
1420	event.fd = trace->input.fd;
1421	if(ioctl(event.fd,FIONREAD,&data)==-1){
1422	perror("ioctl(FIONREAD)");
1423	}
1424	if (data>0) {
1425	trace_read_packet(trace,packet);
1426	event.type = TRACE_EVENT_PACKET;
1427	return event;
1428	}
1429	event.type = TRACE_EVENT_IOWAIT;
1430	return event;
1431	}
1432	case STDIN:
1433	case TRACE:
1434	{
1435	double ts;
1436	/* "Prime" the pump */
1437	if (!trace->packet.buffer) {
1438	trace->packet.buffer = malloc(4096);
1439	trace->packet.size=
1440	trace_read_packet(trace,packet);
1441	}
1442	ts=trace_get_seconds(packet);
1443	if (trace->last_ts!=0) {
1444	event.seconds = ts - trace->last_ts;
1445	if (event.seconds>time(NULL)-trace->start_ts) {
1446	event.type = TRACE_EVENT_SLEEP;
1447	return event;
1448	}
1449
1450	}
1451	else {
1452	trace->start_ts = time(NULL);
1453	trace->last_ts = ts;
1454	}
1455
1456	packet->size = trace->packet.size;
1457	memcpy(packet->buffer,trace->packet.buffer,trace->packet.size);
1458
1459	free(trace->packet.buffer);
1460	trace->packet.buffer = 0;
1461	event.type = TRACE_EVENT_PACKET;
1462	return event;
1463	}
1464	default:
1465	assert(0);
1466	}
1467	assert(0);
1468	}
1469
1470	/** setup a BPF filter
1471	* @param filterstring a char * containing the bpf filter string
1472	* @returns opaque pointer pointer to a libtrace_filter_t object
1473	* @author Daniel Lawson
1474	*/
1475	struct libtrace_filter_t trace_bpf_setfilter(const char filterstring) {
1476	#if HAVE_BPF
1477	struct libtrace_filter_t *filter = malloc(sizeof(struct libtrace_filter_t));
1478	filter->filterstring = strdup(filterstring);
1479	filter->filter = 0;
1480	return filter;
1481	#else
1482	fprintf(stderr,"This version of libtrace does not have bpf filter support\n");
1483	return 0;
1484	#endif
1485	}
1486
1487	/** apply a BPF filter
1488	* @param filter the filter opaque pointer
1489	* @param packet the packet opaque pointer
1490	* @returns 0 if the filter fails, 1 if it succeeds
1491	* @author Daniel Lawson
1492	*/
1493	int trace_bpf_filter(struct libtrace_filter_t *filter,
1494	struct libtrace_packet_t *packet) {
1495	#if HAVE_BPF
1496	void *linkptr = 0;
1497	int clen = 0;
1498	assert(filter);
1499	assert(packet);
1500	linkptr = trace_get_link(packet);
1501	assert(linkptr);
1502	clen = trace_get_capture_length(packet);
1503
1504
1505	if (filter->filterstring && ! filter->filter) {
1506	pcap_t *pcap;
1507	struct bpf_program bpfprog;
1508
1509	switch (trace_get_link_type(packet)) {
1510	case TRACE_TYPE_ETH:
1511	pcap = pcap_open_dead(DLT_EN10MB, 1500);
1512	break;
1513	default:
1514	printf("only works for ETH at the moment\n");
1515	assert(0);
1516	}
1517
1518	// build filter
1519	if (pcap_compile( pcap, &bpfprog, filter->filterstring, 1, 0)) {
1520	printf("bpf compilation error: %s\n",
1521	pcap_geterr(pcap));
1522	assert(0);
1523	}
1524	pcap_close(pcap);
1525	filter->filter = bpfprog.bf_insns;
1526	}
1527
1528	assert(filter->filter);
1529	return bpf_filter(filter->filter, linkptr, clen, clen);
1530	#else
1531	fprintf(stderr,"This version of libtrace does not have bpf filter support\n");
1532	return 0;
1533	#endif
1534	}
1535
1536	/** Set the direction flag, if it has one
1537	* @param packet the packet opaque pointer
1538	* @param direction the new direction (0,1,2,3)
1539	* @returns a signed value containing the direction flag, or -1 if this is not supported
1540	* @author Daniel Lawson
1541	*/
1542	int8_t trace_set_direction(struct libtrace_packet_t *packet, int8_t direction) {
1543
1544	dag_record_t *erfptr = 0;
1545	assert(packet);
1546
1547	switch(packet->trace->format) {
1548	case DAG:
1549	case ERF:
1550	case RTCLIENT:
1551	erfptr = (dag_record_t *)packet->buffer;
1552	erfptr->flags.iface = direction;
1553	break;
1554	default:
1555	direction = -1;
1556	}
1557
1558	return direction;
1559
1560
1561	}
1562
1563	/** Get the direction flag, if it has one
1564	* @param packet a pointer to a libtrace_packet structure
1565	* @returns a signed value containing the direction flag, or -1 if this is not supported
1566	* @author Daniel Lawson
1567	*/
1568	int8_t trace_get_direction(struct libtrace_packet_t *packet) {
1569
1570	int8_t direction;
1571	dag_record_t *erfptr = 0;
1572	assert(packet);
1573
1574	switch(packet->trace->format) {
1575	case DAG:
1576	case ERF:
1577	case RTCLIENT:
1578	erfptr = (dag_record_t *)packet->buffer;
1579	direction = erfptr->flags.iface;
1580	break;
1581	default:
1582	direction = -1;
1583	}
1584
1585	return direction;
1586
1587
1588	}
1589
1590	#define ROOT_SERVER(x) ((x) < 512)
1591	#define ROOT_CLIENT(x) ((512 <= (x)) && ((x) < 1024))
1592	#define NONROOT_SERVER(x) ((x) >= 5000)
1593	#define NONROOT_CLIENT(x) ((1024 <= (x)) && ((x) < 5000))
1594	#define DYNAMIC(x) ((49152 < (x)) && ((x) < 65535))
1595	#define SERVER(x) ROOT_SERVER(x) \|\| NONROOT_SERVER(x)
1596	#define CLIENT(x) ROOT_CLIENT(x) \|\| NONROOT_CLIENT(x)
1597
1598
1599	/** Attempt to deduce the 'server' port
1600	* @param protocol the IP protocol (eg, 6 or 17 for TCP or UDP)
1601	* @param source the TCP or UDP source port
1602	* @param dest the TCP or UDP destination port
1603	* @returns a hint as to which port is the server port
1604	* @author Daniel Lawson
1605	*/
1606	int8_t trace_get_server_port(uint8_t protocol, uint16_t source, uint16_t dest) {
1607	/*
1608	* * If the ports are equal, return DEST
1609	* * Check for well-known ports in the given protocol
1610	* * Root server ports: 0 - 511
1611	* * Root client ports: 512 - 1023
1612	* * non-root client ports: 1024 - 4999
1613	* * non-root server ports: 5000+
1614	* * Check for static ranges: 1024 - 49151
1615	* * Check for dynamic ranges: 49152 - 65535
1616	* * flip a coin.
1617	*/
1618
1619	uint16_t server, client;
1620
1621	/* equal */
1622	if (source == client)
1623	return USE_DEST;
1624
1625	/* root server port, 0 - 511 */
1626	if (ROOT_SERVER(source) && ROOT_SERVER(dest)) {
1627	if (source < dest)
1628	return USE_SOURCE;
1629	return USE_DEST;
1630	}
1631
1632	if (ROOT_SERVER(source) && !ROOT_SERVER(dest))
1633	return USE_SOURCE;
1634	if (!ROOT_SERVER(source) && ROOT_SERVER(dest))
1635	return USE_DEST;
1636
1637	/* non-root server */
1638	if (NONROOT_SERVER(source) && NONROOT_SERVER(dest)) {
1639	if (source < dest)
1640	return USE_SOURCE;
1641	return USE_DEST;
1642	}
1643	if (NONROOT_SERVER(source) && !NONROOT_SERVER(dest))
1644	return USE_SOURCE;
1645	if (!NONROOT_SERVER(source) && NONROOT_SERVER(dest))
1646	return USE_DEST;
1647
1648	/* root client */
1649	if (ROOT_CLIENT(source) && ROOT_CLIENT(dest)) {
1650	if (source < dest)
1651	return USE_SOURCE;
1652	return USE_DEST;
1653	}
1654	if (ROOT_CLIENT(source) && !ROOT_CLIENT(dest)) {
1655	/* prefer root-client over nonroot-client */
1656	if (NONROOT_CLIENT(dest))
1657	return USE_SOURCE;
1658	return USE_DEST;
1659	}
1660	if (!ROOT_CLIENT(source) && ROOT_CLIENT(dest)) {
1661	/* prefer root-client over nonroot-client */
1662	if (NONROOT_CLIENT(source))
1663	return USE_DEST;
1664	return USE_SOURCE;
1665	}
1666
1667	/* nonroot client */
1668	if (NONROOT_CLIENT(source) && NONROOT_CLIENT(dest)) {
1669	if (source < dest)
1670	return USE_SOURCE;
1671	return USE_DEST;
1672	}
1673	if (NONROOT_CLIENT(source) && !NONROOT_CLIENT(dest))
1674	return USE_DEST;
1675	if (!NONROOT_CLIENT(source) && NONROOT_CLIENT(dest))
1676	return USE_SOURCE;
1677
1678	/* dynamic range */
1679	if (DYNAMIC(source) && DYNAMIC(dest))
1680	if (source < dest)
1681	return USE_SOURCE;
1682	return USE_DEST;
1683	if (DYNAMIC(source) && !DYNAMIC(dest))
1684	return USE_DEST;
1685	if (!DYNAMIC(source) && DYNAMIC(dest))
1686	return USE_SOURCE;
1687	/*
1688	if (SERVER(source) && CLIENT(dest))
1689	return USE_SOURCE;
1690
1691	if (SERVER(dest) && CLIENT(source))
1692	return USE_DEST;
1693	if (ROOT_SERVER(source) && !ROOT_SERVER(dest))
1694	return USE_SOURCE;
1695	if (ROOT_SERVER(dest) && !ROOT_SERVER(source))
1696	return USE_DEST;
1697	*/
1698	// failing that test...
1699	if (source < dest) {
1700	return USE_SOURCE;
1701	}
1702	return USE_DEST;
1703
1704	}
1705
1706	/** Truncate the packet at the suggested length
1707	* @param packet the packet opaque pointer
1708	* @param size the new length of the packet
1709	* @returns the new length of the packet, or the original length of the
1710	* packet if unchanged
1711	* NOTE: len refers to the network-level payload of the packet, and not
1712	* any capture headers included as well. For example, to truncate a packet
1713	* after the IP header, set scan to sizeof(ethernet_header) + sizeof(ip_header)
1714	* @author Daniel Lawson
1715	*/
1716	size_t trace_truncate_packet(struct libtrace_packet_t *packet, size_t size) {
1717	dag_record_t *erfptr;
1718	#if HAVE_PCAP
1719	struct pcap_pkthdr *pcaphdr;
1720	#endif
1721
1722	assert(packet);
1723
1724	if (size > packet->size) {
1725	// can't make a packet larger
1726	return packet->size;
1727	}
1728	switch (packet->trace->format) {
1729	#if HAVE_PCAP
1730	case PCAPINT:
1731	case PCAP:
1732	pcaphdr = (struct pcap_pkthdr *)packet->buffer;
1733	pcaphdr->caplen = size + sizeof(struct pcap_pkthdr);
1734	packet->size = pcaphdr->caplen;
1735	break;
1736	#endif
1737	case ERF:
1738	case DAG:
1739	case RTCLIENT:
1740	erfptr = (dag_record_t *)packet->buffer;
1741	erfptr->rlen = ntohs(size + sizeof(dag_record_t));
1742	packet->size = size + sizeof(dag_record_t);
1743	break;
1744	case WAGINT:
1745	case WAG:
1746	// don't know how to do this?
1747	break;
1748	}
1749	return packet->size;
1750	}
1751

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