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source: lib/trace.c @ 7bb7dda

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

Last change on this file since 7bb7dda was 7bb7dda, checked in by Daniel Lawson <dlawson@…>, 17 years ago
improved trace_event() in the case of trace playback. Seems to work fine now :)
Property mode set to `100644`
File size: 50.8 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_INTTYPES_H
71	# include <inttypes.h>
72	#else
73	# error "Can't find inttypes.h - this needs to be fixed"
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	#else
88	# ifdef HAVE_NET_BPF_H
89	# include <net/bpf.h>
90	# endif
91	#endif
92
93	#if HAVE_PCAP_H
94	# include <pcap.h>
95	#endif
96
97	#ifdef HAVE_ZLIB_H
98	# include <zlib.h>
99	#endif
100
101
102	#include "wag.h"
103
104	#ifdef HAVE_DAG_API
105	# include "dagnew.h"
106	# include "dagapi.h"
107	#else
108	# include "dagformat.h"
109	#endif
110
111
112	typedef enum {SOCKET, TRACE, STDIN, DEVICE, INTERFACE, RT } source_t;
113
114	typedef enum {ERF, PCAP, PCAPINT, DAG, RTCLIENT, WAG, WAGINT } format_t;
115
116	#if HAVE_BPF
117	/** A type encapsulating a bpf filter
118	* This type covers the compiled bpf filter, as well as the original filter
119	* string
120	*
121	*/
122	struct libtrace_filter_t {
123	struct bpf_insn *filter;
124	char * filterstring;
125	};
126	#endif
127
128	/** The information about traces that are open
129	* @internal
130	*/
131	struct libtrace_t {
132	format_t format; /*< The format that this trace is in /
133	source_t sourcetype; /*< The type (device,file, etc /
134	union {
135	/** Information about rtclients */
136	struct {
137	char *hostname;
138	short port;
139	} rt;
140	char path; /< information for local sockets /
141	char interface; /*< intormation for reading of network
142	interfaces */
143	} conn_info;
144	/** Information about the current state of the input device */
145	union {
146	int fd;
147	#if HAVE_ZLIB
148	gzFile *file;
149	#else
150	FILE *file;
151	#endif
152	#if HAVE_PCAP
153	pcap_t *pcap;
154	#endif
155	} input;
156	struct fifo_t *fifo;
157	struct {
158	void *buf;
159	unsigned bottom;
160	unsigned top;
161	unsigned diff;
162	unsigned curr;
163	unsigned offset;
164	} dag;
165	struct {
166	void *buffer;
167	int size;
168	} packet;
169	double tdelta;
170	double trace_start_ts;
171	double real_start_ts;
172	double trace_last_ts;
173
174	double last_ts;
175	double start_ts;
176	};
177
178	struct trace_sll_header_t {
179	uint16_t pkttype; /* packet type */
180	uint16_t hatype; /* link-layer address type */
181	uint16_t halen; /* link-layer address length */
182	char addr[8]; /* link-layer address */
183	uint16_t protocol; /* protocol */
184	};
185
186	#define RP_BUFSIZE 65536
187
188	#define URI_PROTO_LINE 16
189	static int init_trace(struct libtrace_t *libtrace, char uri) {
190	char *scan = calloc(sizeof(char),URI_PROTO_LINE);
191	char *uridata = 0;
192	struct stat buf;
193
194	// parse the URI to determine what sort of event we are dealing with
195
196	// want snippet before the : to get the uri base type.
197
198	if((uridata = strchr(uri,':')) == NULL) {
199	// badly formed URI - needs a :
200	return 0;
201	}
202
203	if ((uridata - uri) > URI_PROTO_LINE) {
204	// badly formed URI - uri type is too long
205	return 0;
206	}
207	strncpy(scan,uri, (uridata - uri));
208
209	(*libtrace)->tdelta = 0.0;
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	#if HAVE_DAG
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	#if HAVE_DAG
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	1,
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	#if HAVE_DAG
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	#if HAVE_DAG
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	#if HAVE_DAG
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	#if HAVE_PCAP
630	void trace_pcap_handler(u_char user, const struct pcap_pkthdr pcaphdr, const u_char *pcappkt) {
631	struct libtrace_packet_t packet = (struct libtrace_packet_t )user;
632	void *buffer = packet->buffer;
633	int numbytes = 0;
634
635	memcpy(buffer,pcaphdr,sizeof(struct pcap_pkthdr));
636	numbytes = pcaphdr->len;
637	memcpy(buffer + sizeof(struct pcap_pkthdr),pcappkt,numbytes);
638
639	packet->size = numbytes + sizeof(struct pcap_pkthdr);
640
641	}
642	#endif
643	/** Read one packet from the trace into buffer
644	*
645	* @param libtrace the libtrace opaque pointer
646	* @param packet the packet opaque pointer
647	* @returns false if it failed to read a packet
648	*
649	*/
650	int trace_read_packet(struct libtrace_t libtrace, struct libtrace_packet_t packet) {
651	int numbytes;
652	int size;
653	char buf[RP_BUFSIZE];
654	#if HAVE_PCAP
655	//struct pcap_pkthdr *pcaphdr = malloc(sizeof(struct pcap_pkthdr));
656	const u_char *pcappkt;
657	int pcapbytes = 0;
658	#endif
659	dag_record_t *erfptr;
660	int read_required = 0;
661
662	void *buffer = 0;
663	if (!libtrace) {
664	fprintf(stderr,"Oi! You called trace_read_packet() with a NULL libtrace parameter!\n");
665	}
666	assert(libtrace);
667	assert(packet);
668
669	/* Store the trace we are reading from into the packet opaque
670	* structure */
671	packet->trace = libtrace;
672
673	buffer = packet->buffer;
674	#if HAVE_PCAP
675	/* PCAP gives us it's own per-packet interface. Let's use it */
676	if (libtrace->format == PCAP \|\| libtrace->format == PCAPINT) {
677	/* pcap_next doesn't return enough information for us
678	* newer libpcap has pcap_next_ex, which does, but we'd
679	* really rather have it all the time. */
680
681	//if ((pcappkt = pcap_next(libtrace->input.pcap, &pcaphdr)) == NULL) {
682	/*
683	if ((pcapbytes = pcap_next_ex(libtrace->input.pcap,
684	&pcaphdr,
685	&pcappkt)) < 0 ) {
686	*/
687	/* Instead of pcap_next/pcap_next_ex, we do this ourselves
688	* with a trivial callback function. This lets us
689	* catch the same errors as pcap_next_ex, but removes
690	* the requirement for libpcap >= 0.8.x
691	*/
692	while ((pcapbytes = pcap_dispatch(libtrace->input.pcap,
693	1, /* number of packets */
694	&trace_pcap_handler,
695	(u_char *)packet)) == 0);
696
697	if (pcapbytes < 0 ) {
698	return -1;
699	}
700	return (packet->size - sizeof(struct pcap_pkthdr));
701	//memcpy(buffer,&pcaphdr,sizeof(struct pcap_pkthdr));
702	//numbytes = pcaphdr->len;
703	//memcpy(buffer + sizeof(struct pcap_pkthdr),pcappkt,numbytes);
704
705	//packet->size = numbytes + sizeof(struct pcap_pkthdr);
706	//return numbytes;
707	}
708	#endif
709
710	/* If we're reading from an ERF input, it's an offline trace. We can make some assumptions */
711	if (libtrace->format == ERF) {
712	void *buffer2 = buffer;
713	int rlen;
714	// read in the trace header
715	if ((numbytes=gzread(libtrace->input.file,
716	buffer,
717	dag_record_size)) == -1) {
718	perror("gzread");
719	return -1;
720	}
721	if (numbytes == 0) {
722	return 0;
723	}
724	rlen = ntohs(((dag_record_t *)buffer)->rlen);
725	size = rlen - dag_record_size;
726	assert(size < LIBTRACE_PACKET_BUFSIZE);
727	buffer2 = buffer + dag_record_size;
728
729	// read in the rest of the packet
730	if ((numbytes=gzread(libtrace->input.file,
731	buffer2,
732	size)) == -1) {
733	perror("gzread");
734	return -1;
735	}
736	//if ((numbytes + dag_record_size) != rlen) {
737	// printf("read %d wanted %d\n",numbytes +dag_record_size, rlen);
738	//}
739	packet->size = rlen;
740
741	return rlen;
742	}
743
744	#if HAVE_DAG
745	if (libtrace->format == DAG) {
746	if (libtrace->dag.diff == 0) {
747	if ((numbytes = trace_read(libtrace,buf,RP_BUFSIZE)) <= 0)
748	return numbytes;
749	}
750	// DAG always gives us whole packets.
751
752	erfptr = (dag_record_t ) ((void )libtrace->dag.buf + (libtrace->dag.bottom + libtrace->dag.offset));
753	size = ntohs(erfptr->rlen);
754
755	if ( size > LIBTRACE_PACKET_BUFSIZE) {
756	printf("%d\n",size);
757	assert( size < LIBTRACE_PACKET_BUFSIZE);
758	}
759
760	// have to copy it out of the memory hole at this stage:
761	memcpy(packet->buffer, erfptr, size);
762
763	packet->size = size;
764	libtrace->dag.offset += size;
765	libtrace->dag.diff -= size;
766
767	assert(libtrace->dag.diff >= 0);
768	//assert(libtrace->dag.offset <= libtrace->dag.top);
769	return (size);
770
771	}
772	#endif
773	do {
774	if (fifo_out_available(libtrace->fifo) == 0 \|\| read_required) {
775	if ((numbytes = trace_read(libtrace,buf,RP_BUFSIZE))<=0){
776	return numbytes;
777	}
778	assert(libtrace->fifo);
779	fifo_write(libtrace->fifo,buf,numbytes);
780
781	read_required = 0;
782	}
783
784	switch (libtrace->format) {
785	case RTCLIENT:
786	// only do this if we're reading from the RT interface
787	if (fifo_out_read(libtrace->fifo, &packet->status, sizeof(int)) == 0) {
788	read_required = 1;
789	continue;
790	}
791
792	fifo_out_update(libtrace->fifo,sizeof(int));
793
794	/* FALL THRU */
795	case ERF:
796	//case DAG:
797	// read in the erf header
798	if ((numbytes = fifo_out_read(libtrace->fifo, buffer, sizeof(dag_record_t))) == 0) {
799	fifo_out_reset(libtrace->fifo);
800	read_required = 1;
801	continue;
802	}
803
804	size = ntohs(((dag_record_t *)buffer)->rlen);
805	break;
806	case WAG:
807	if ((numbytes = fifo_out_read(libtrace->fifo,
808	&size,
809	sizeof(size)))
810	== 0) {
811	fifo_out_reset(libtrace->fifo);
812	read_required = 1;
813	continue;
814	}
815	size*=4;
816	break;
817	default:
818	fprintf(stderr,"Unknown type in _read()\n");
819	assert(0);
820	}
821
822	assert(size < LIBTRACE_PACKET_BUFSIZE);
823
824	// read in the full packet
825	if ((numbytes = fifo_out_read(libtrace->fifo, buffer, size)) == 0) {
826	fifo_out_reset(libtrace->fifo);
827	read_required = 1;
828	continue;
829	}
830
831	// got in our whole packet, so...
832	fifo_out_update(libtrace->fifo,size);
833
834	if (libtrace->sourcetype == SOCKET \|\| libtrace->sourcetype == RT) {
835	fifo_ack_update(libtrace->fifo,size + sizeof(int));
836	} else {
837	fifo_ack_update(libtrace->fifo,size);
838	}
839
840	packet->size = numbytes;
841	return numbytes;
842
843	} while (1);
844	}
845
846
847	/** get a pointer to the link layer
848	* @param packet a pointer to a libtrace_packet structure
849	*
850	* @returns a pointer to the link layer, or NULL if there is no link layer
851	* you should call trace_get_link_type() to find out what type of link layer this is
852	*/
853	void trace_get_link(const struct libtrace_packet_t packet) {
854	const void *ethptr = 0;
855	dag_record_t *erfptr = 0;
856	struct wag_event_t event = (struct wag_event_t )packet->buffer;
857	struct wag_data_event_t *data_event;
858
859
860	switch(packet->trace->format) {
861	case ERF:
862	case DAG:
863	case RTCLIENT:
864	erfptr = (dag_record_t *)packet->buffer;
865	if (erfptr->flags.rxerror == 1) {
866	return NULL;
867	}
868	if (trace_get_link_type(packet)==TRACE_TYPE_ETH)
869	ethptr = ((uint8_t *)packet->buffer +
870	dag_record_size + 2);
871	else
872	ethptr = ((uint8_t *)packet->buffer +
873	dag_record_size + 2);
874	break;
875	#if HAVE_PCAP
876	case PCAPINT:
877	case PCAP:
878	ethptr = (packet->buffer + sizeof(struct pcap_pkthdr));
879	break;
880	#endif
881	case WAGINT:
882	case WAG:
883	switch (event->type) {
884	case 0x0:
885	data_event = (void*)&(event->payload);
886	return data_event->data;
887	default:
888	fprintf(stderr,"Unknown WAG Event (0x%08x)\n",event->type);
889	return NULL;
890	}
891
892	default:
893	fprintf(stderr,"Don't know this trace format\n");
894	assert(0);
895	}
896	return ethptr;
897	}
898
899	/** get a pointer to the IP header (if any)
900	* @param packet a pointer to a libtrace_packet structure
901	*
902	* @returns a pointer to the IP header, or NULL if there is not an IP packet
903	*/
904	struct libtrace_ip trace_get_ip(struct libtrace_packet_t packet) {
905	struct libtrace_ip *ipptr = 0;
906
907	switch(trace_get_link_type(packet)) {
908	case TRACE_TYPE_80211:
909	{
910
911	struct ieee_802_11_header *wifi = trace_get_link(packet);
912	if (!wifi) {
913	ipptr = NULL;
914	break;
915	}
916
917	// Data packet?
918	if (wifi->type != 2) {
919	ipptr = NULL;
920	}
921	else {
922	struct ieee_802_11_payload eth = (void)wifi->data;
923	if (eth->type != 0x0008) {
924	ipptr=NULL;
925	} else {
926	ipptr=(void*)eth->data;
927	}
928	}
929	}
930	break;
931	case TRACE_TYPE_ETH:
932	{
933	struct ether_header *eth =
934	trace_get_link(packet);
935	if (!eth) {
936	ipptr = NULL;
937	break;
938	}
939	if (ntohs(eth->ether_type)!=0x0800) {
940	ipptr = NULL;
941	}
942	else {
943	ipptr = ((void *)eth) + 14;
944	}
945	break;
946	}
947	case TRACE_TYPE_NONE:
948	ipptr = trace_get_link(packet);
949	break;
950	case TRACE_TYPE_LINUX_SLL:
951	{
952	struct trace_sll_header_t *sll;
953
954	sll = trace_get_link(packet);
955	if (!sll) {
956	ipptr = NULL;
957	break;
958	}
959	if (ntohs(sll->protocol)!=0x0800) {
960	ipptr = NULL;
961	}
962	else {
963	ipptr = ((void)sll)+sizeof(sll);
964	}
965	}
966	break;
967	case TRACE_TYPE_ATM:
968	{
969	struct atm_rec *atm =
970	trace_get_link(packet);
971	// TODO: Find out what ATM does, and return
972	// NULL for non IP data
973	// Presumably it uses the normal stuff
974	if (!atm) {
975	ipptr = NULL;
976	break;
977	}
978	ipptr = (void*)&atm->pload;
979	break;
980	}
981	default:
982	fprintf(stderr,"Don't understand link layer type %i in trace_get_ip()\n",
983	trace_get_link_type(packet));
984	ipptr=NULL;
985	break;
986	}
987
988	return ipptr;
989	}
990
991	#define SW_IP_OFFMASK 0xff1f
992
993	/** get a pointer to the TCP header (if any)
994	* @param packet a pointer to a libtrace_packet structure
995	*
996	* @returns a pointer to the TCP header, or NULL if there is not a TCP packet
997	*/
998	struct libtrace_tcp trace_get_tcp(struct libtrace_packet_t packet) {
999	struct libtrace_tcp *tcpptr = 0;
1000	struct libtrace_ip *ipptr = 0;
1001
1002	if(!(ipptr = trace_get_ip(packet))) {
1003	return 0;
1004	}
1005	if ((ipptr->ip_p == 6) && ((ipptr->ip_off & SW_IP_OFFMASK) == 0)) {
1006	tcpptr = (struct libtrace_tcp )((ptrdiff_t)ipptr + (ipptr->ip_hl 4));
1007	}
1008	return tcpptr;
1009	}
1010
1011	/** get a pointer to the TCP header (if any) given a pointer to the IP header
1012	* @param ip The IP header
1013	* @param[out] skipped An output variable of the number of bytes skipped
1014	*
1015	* @returns a pointer to the TCP header, or NULL if this is not a TCP packet
1016	*
1017	* Skipped can be NULL, in which case it will be ignored by the program.
1018	*/
1019	struct libtrace_tcp get_tcp_from_ip(struct libtrace_ip ip, int *skipped)
1020	{
1021	#define SW_IP_OFFMASK 0xff1f
1022	struct libtrace_tcp *tcpptr = 0;
1023
1024	if ((ip->ip_p == 6) && ((ip->ip_off & SW_IP_OFFMASK) == 0)) {
1025	tcpptr = (struct libtrace_tcp )((ptrdiff_t)ip+ (ip->ip_hl 4));
1026	}
1027
1028	if (skipped)
1029	skipped=(ip->ip_hl4);
1030
1031	return tcpptr;
1032	}
1033
1034	/** get a pointer to the UDP header (if any)
1035	* @param packet a pointer to a libtrace_packet structure
1036	*
1037	* @returns a pointer to the UDP header, or NULL if this is not a UDP packet
1038	*/
1039	struct libtrace_udp trace_get_udp(struct libtrace_packet_t packet) {
1040	struct libtrace_udp *udpptr = 0;
1041	struct libtrace_ip *ipptr = 0;
1042
1043	if(!(ipptr = trace_get_ip(packet))) {
1044	return 0;
1045	}
1046	if ((ipptr->ip_p == 17) && ((ipptr->ip_off & SW_IP_OFFMASK) == 0)) {
1047	udpptr = (struct libtrace_udp )((ptrdiff_t)ipptr + (ipptr->ip_hl 4));
1048	}
1049
1050	return udpptr;
1051	}
1052
1053	/** get a pointer to the UDP header (if any) given a pointer to the IP header
1054	* @param ip The IP header
1055	* @param[out] skipped An output variable of the number of bytes skipped
1056	*
1057	* @returns a pointer to the UDP header, or NULL if this is not a UDP packet
1058	*
1059	* Skipped can be NULL, in which case it will be ignored by the program.
1060	*/
1061	struct libtrace_udp get_udp_from_ip(struct libtrace_ip ip, int *skipped)
1062	{
1063	struct libtrace_udp *udpptr = 0;
1064
1065	if ((ip->ip_p == 6) && ((ip->ip_off & SW_IP_OFFMASK) == 0)) {
1066	udpptr = (struct libtrace_udp )((ptrdiff_t)ip+ (ip->ip_hl 4));
1067	}
1068
1069	if (skipped)
1070	skipped=(ip->ip_hl4);
1071
1072	return udpptr;
1073	}
1074
1075
1076	/** get a pointer to the ICMP header (if any)
1077	* @param packet a pointer to a libtrace_packet structure
1078	*
1079	* @returns a pointer to the ICMP header, or NULL if this is not a ICMP packet
1080	*/
1081	struct libtrace_icmp trace_get_icmp(struct libtrace_packet_t packet) {
1082	struct libtrace_icmp *icmpptr = 0;
1083	struct libtrace_ip *ipptr = 0;
1084
1085	if(!(ipptr = trace_get_ip(packet))) {
1086	return 0;
1087	}
1088	if ((ipptr->ip_p == 1)&& ((ipptr->ip_off & SW_IP_OFFMASK) == 0 )){
1089	icmpptr = (struct libtrace_icmp )((ptrdiff_t)ipptr + (ipptr->ip_hl 4));
1090	}
1091	return icmpptr;
1092	}
1093
1094	/** get a pointer to the ICMP header (if any) given a pointer to the IP header
1095	* @param ip The IP header
1096	* @param[out] skipped An output variable of the number of bytes skipped
1097	*
1098	* @returns a pointer to the ICMP header, or NULL if this is not a ICMP packet
1099	*
1100	* Skipped can be NULL, in which case it will be ignored by the program.
1101	*/
1102	struct libtrace_icmp get_icmp_from_ip(struct libtrace_ip ip, int *skipped)
1103	{
1104	struct libtrace_icmp *icmpptr = 0;
1105
1106	if ((ip->ip_p == 6) && ((ip->ip_off & SW_IP_OFFMASK) == 0)) {
1107	icmpptr = (struct libtrace_icmp )((ptrdiff_t)ip+ (ip->ip_hl 4));
1108	}
1109
1110	if (skipped)
1111	skipped=(ip->ip_hl4);
1112
1113	return icmpptr;
1114	}
1115	/** parse an ip or tcp option
1116	* @param[in,out] ptr the pointer to the current option
1117	* @param[in,out] len the length of the remaining buffer
1118	* @param[out] type the type of the option
1119	* @param[out] optlen the length of the option
1120	* @param[out] data the data of the option
1121	*
1122	* @returns bool true if there is another option (and the fields are filled in)
1123	* or false if this was the last option.
1124	*
1125	* This updates ptr to point to the next option after this one, and updates
1126	* len to be the number of bytes remaining in the options area. Type is updated
1127	* to be the code of this option, and data points to the data of this option,
1128	* with optlen saying how many bytes there are.
1129	*
1130	* @note Beware of fragmented packets.
1131	* @author Perry Lorier
1132	*/
1133	int trace_get_next_option(unsigned char *ptr,int len,
1134	unsigned char *type,
1135	unsigned char *optlen,
1136	unsigned char **data)
1137	{
1138	if (*len<=0)
1139	return 0;
1140	type=*ptr;
1141	switch(*type) {
1142	case 0: /* End of options */
1143	return 0;
1144	case 1: /* Pad */
1145	(*ptr)++;
1146	(*len)--;
1147	return 1;
1148	default:
1149	optlen = (*ptr+1);
1150	if (*optlen<2)
1151	return 0; // I have no idea wtf is going on
1152	// with these packets
1153	(len)-=optlen;
1154	(data)=(ptr+2);
1155	(ptr)+=optlen;
1156	if (*len<0)
1157	return 0;
1158	return 1;
1159	}
1160	assert(0);
1161	}
1162
1163
1164	/** Get the current time in DAG time format
1165	* @param packet a pointer to a libtrace_packet structure
1166	* @returns a 64 bit timestamp in DAG ERF format (upper 32 bits are the seconds
1167	* past 1970-01-01, the lower 32bits are partial seconds)
1168	* @author Daniel Lawson
1169	*/
1170	uint64_t trace_get_erf_timestamp(const struct libtrace_packet_t *packet) {
1171	uint64_t timestamp = 0;
1172	dag_record_t *erfptr = 0;
1173	struct pcap_pkthdr *pcapptr = 0;
1174	struct wag_event_t *wagptr = 0;
1175	switch (packet->trace->format) {
1176	case DAG:
1177	case ERF:
1178	case RTCLIENT:
1179	erfptr = (dag_record_t *)packet->buffer;
1180	timestamp = erfptr->ts;
1181	break;
1182	#if HAVE_PCAP
1183	case PCAPINT:
1184	case PCAP:
1185	pcapptr = (struct pcap_pkthdr *)packet->buffer;
1186	timestamp = ((((uint64_t)pcapptr->ts.tv_sec) << 32) + \
1187	(pcapptr->ts.tv_usec*UINT_MAX/1000000));
1188	break;
1189	#endif
1190	case WAGINT:
1191	case WAG:
1192	wagptr = (struct wag_event_t *)packet->buffer;
1193	timestamp = wagptr->timestamp_lo;
1194	timestamp \|= (uint64_t)wagptr->timestamp_hi<<32;
1195	timestamp = ((timestamp%44000000)*(UINT_MAX/44000000))
1196	\| ((timestamp/44000000)<<32);
1197	break;
1198	default:
1199	fprintf(stderr,"Unknown format in trace_get_erf_timestamp\n");
1200	timestamp = 0;
1201	}
1202	return timestamp;
1203	}
1204
1205	/** Get the current time in struct timeval
1206	* @param packet a pointer to a libtrace_packet structure
1207	*
1208	* @returns time that this packet was seen in a struct timeval
1209	* @author Daniel Lawson
1210	* @author Perry Lorier
1211	*/
1212	struct timeval trace_get_timeval(const struct libtrace_packet_t *packet) {
1213	struct timeval tv;
1214	#if HAVE_PCAP
1215	struct pcap_pkthdr *pcapptr = 0;
1216	#endif
1217	uint64_t ts;
1218	//uint32_t seconds;
1219	switch (packet->trace->format) {
1220	#if HAVE_PCAP
1221	case PCAPINT:
1222	case PCAP:
1223	pcapptr = (struct pcap_pkthdr *)packet->buffer;
1224	tv = pcapptr->ts;
1225	break;
1226	#endif
1227	case WAGINT:
1228	case WAG:
1229	case DAG:
1230	case ERF:
1231	case RTCLIENT:
1232	default:
1233	// FIXME: This isn't portable to big-endian machines
1234	ts = trace_get_erf_timestamp(packet);
1235	tv.tv_sec = ts >> 32;
1236	ts = (1000000 * (ts & 0xffffffffULL));
1237	ts += (ts & 0x80000000ULL) << 1;
1238	tv.tv_usec = ts >> 32;
1239	if (tv.tv_usec >= 1000000) {
1240	tv.tv_usec -= 1000000;
1241	tv.tv_sec += 1;
1242	}
1243	break;
1244	}
1245	return tv;
1246	}
1247
1248	/** Get the current time in floating point seconds
1249	* @param packet a pointer to a libtrace_packet structure
1250	* @returns time that this packet was seen in 64bit floating point seconds
1251	* @author Perry Lorier
1252	*/
1253	double trace_get_seconds(const struct libtrace_packet_t *packet) {
1254	uint64_t ts;
1255	ts = trace_get_erf_timestamp(packet);
1256	return (ts>>32) + ((ts & UINT_MAX)*1.0 / UINT_MAX);
1257	}
1258
1259	/** Get the size of the packet in the trace
1260	* @param packet the packet opaque pointer
1261	* @returns the size of the packet in the trace
1262	* @author Perry Lorier
1263	* @note Due to this being a header capture, or anonymisation, this may not
1264	* be the same size as the original packet. See trace_get_wire_length() for the
1265	* original size of the packet.
1266	* @note This can (and often is) different for different packets in a trace!
1267	* @par
1268	* This is sometimes called the "snaplen".
1269	*/
1270	int trace_get_capture_length(const struct libtrace_packet_t *packet) {
1271	dag_record_t *erfptr = 0;
1272	#if HAVE_PCAP
1273	struct pcap_pkthdr *pcapptr = 0;
1274	#endif
1275	struct wag_event_t *wag_event;
1276	switch (packet->trace->format) {
1277	case DAG:
1278	case ERF:
1279	case RTCLIENT:
1280	erfptr = (dag_record_t *)packet->buffer;
1281	return ntohs(erfptr->rlen);
1282	#if HAVE_PCAP
1283	case PCAPINT:
1284	case PCAP:
1285	pcapptr = (struct pcap_pkthdr *)packet->buffer;
1286	//return ntohs(pcapptr->caplen);
1287	return pcapptr->caplen;
1288	#endif
1289	case WAGINT:
1290	case WAG:
1291	wag_event = (struct wag_event_t *)packet->buffer;
1292	switch(wag_event->type) {
1293	case 0:
1294	return wag_event->length*4-(
1295	sizeof(struct wag_event_t)+
1296	sizeof(struct wag_data_event_t)
1297	);
1298	default:
1299	assert(0);
1300	}
1301	default:
1302	assert(0);
1303	}
1304	return -1;
1305	}
1306
1307	/** Get the size of the packet as it was seen on the wire.
1308	* @param packet a pointer to a libtrace_packet structure
1309	*
1310	* @returns the size of the packet as it was on the wire.
1311	* @author Perry Lorier
1312	* @author Daniel Lawson
1313	* @note Due to the trace being a header capture, or anonymisation this may
1314	* not be the same as the Capture Len.
1315	*/
1316	int trace_get_wire_length(const struct libtrace_packet_t *packet){
1317	dag_record_t *erfptr = 0;
1318	#if HAVE_PCAP
1319	struct pcap_pkthdr *pcapptr = 0;
1320	#endif
1321	struct wag_event_t *wag_event = 0;
1322	switch (packet->trace->format) {
1323	case DAG:
1324	case ERF:
1325	case RTCLIENT:
1326	erfptr = (dag_record_t *)packet->buffer;
1327	return ntohs(erfptr->wlen);
1328	break;
1329	#if HAVE_PCAP
1330	case PCAPINT:
1331	case PCAP:
1332	pcapptr = (struct pcap_pkthdr *)packet->buffer;
1333	return ntohs(pcapptr->len);
1334	break;
1335	#endif
1336	case WAGINT:
1337	case WAG:
1338	wag_event = (struct wag_event_t *)packet->buffer;
1339	switch(wag_event->type) {
1340	case 0:
1341	return ((struct wag_data_event_t *)(&wag_event->payload))->frame_length;
1342	default:
1343	assert(0);
1344	}
1345	}
1346	return -1;
1347
1348	}
1349
1350	/** Get the type of the link layer
1351	* @param packet a pointer to a libtrace_packet structure
1352	* @returns libtrace_linktype_t
1353	* @author Perry Lorier
1354	* @author Daniel Lawson
1355	*/
1356	libtrace_linktype_t trace_get_link_type(const struct libtrace_packet_t *packet ) {
1357	dag_record_t *erfptr = 0;
1358	#if HAVE_PCAP
1359	struct pcap_pkthdr *pcapptr = 0;
1360	#endif
1361	int linktype = 0;
1362	switch (packet->trace->format) {
1363	case DAG:
1364	case ERF:
1365	case RTCLIENT:
1366	erfptr = (dag_record_t *)packet->buffer;
1367	switch (erfptr->type) {
1368	case TYPE_ETH: return TRACE_TYPE_ETH;
1369	case TYPE_ATM: return TRACE_TYPE_ATM;
1370	default: assert(0);
1371	}
1372	return erfptr->type;
1373
1374	break;
1375	#if HAVE_PCAP
1376	case PCAPINT:
1377	case PCAP:
1378	pcapptr = (struct pcap_pkthdr *)packet->buffer;
1379	linktype = pcap_datalink(packet->trace->input.pcap);
1380	switch (linktype) {
1381	case DLT_NULL:
1382	return TRACE_TYPE_NONE;
1383	case DLT_EN10MB:
1384	return TRACE_TYPE_ETH;
1385	case DLT_ATM_RFC1483:
1386	return TRACE_TYPE_ATM;
1387	case DLT_IEEE802_11:
1388	return TRACE_TYPE_80211;
1389	#ifdef DLT_LINUX_SLL
1390	case DLT_LINUX_SLL:
1391	return TRACE_TYPE_LINUX_SLL;
1392	#endif
1393	}
1394	break;
1395	#endif
1396	case WAGINT:
1397	case WAG:
1398	return TRACE_TYPE_80211;
1399	}
1400	return -1;
1401	}
1402
1403	/** Get the source MAC addres
1404	* @param packet a pointer to a libtrace_packet structure
1405	* @returns a pointer to the source mac, (or NULL if there is no source MAC)
1406	* @author Perry Lorier
1407	*/
1408	uint8_t trace_get_source_mac(const struct libtrace_packet_t packet) {
1409	void *link = trace_get_link(packet);
1410	struct ieee_802_11_header *wifi = link;
1411	struct ether_header *ethptr = link;
1412	if (!link)
1413	return NULL;
1414	switch (trace_get_link_type(packet)) {
1415	case TRACE_TYPE_80211:
1416	return (uint8_t*)&wifi->mac2;
1417	case TRACE_TYPE_ETH:
1418	return (uint8_t*)&ethptr->ether_shost;
1419	default:
1420	fprintf(stderr,"Not implemented\n");
1421	assert(0);
1422	}
1423	}
1424
1425	/** Get the destination MAC addres
1426	* @param packet a libtrace_packet pointer
1427	* @returns a pointer to the destination mac, (or NULL if there is no
1428	* destination MAC)
1429	* @author Perry Lorier
1430	*/
1431	uint8_t trace_get_destination_mac(const struct libtrace_packet_t packet) {
1432	void *link = trace_get_link(packet);
1433	struct ieee_802_11_header *wifi = link;
1434	struct ether_header *ethptr = link;
1435	if (!link)
1436	return NULL;
1437	switch (trace_get_link_type(packet)) {
1438	case TRACE_TYPE_80211:
1439	return (uint8_t*)&wifi->mac1;
1440	case TRACE_TYPE_ETH:
1441	return (uint8_t*)&ethptr->ether_dhost;
1442	default:
1443	fprintf(stderr,"Not implemented\n");
1444	assert(0);
1445	}
1446	}
1447
1448
1449	/** process a libtrace event
1450	* @param trace the libtrace opaque pointer
1451	* @param packet the libtrace_packet opaque pointer
1452	* @returns
1453	* TRACE_EVENT_IOWAIT Waiting on I/O on fd
1454	* TRACE_EVENT_SLEEP Next event in seconds
1455	* TRACE_EVENT_PACKET Packet arrived in buffer with size size
1456	* TRACE_EVENT_TERMINATE Trace terminated (perhaps with an error condition)
1457	* FIXME currently keeps a copy of the packet inside the trace pointer,
1458	* which in turn is stored inside the new packet object...
1459	* @author Perry Lorier
1460	*/
1461	struct libtrace_eventobj_t trace_event(struct libtrace_t *trace,
1462	struct libtrace_packet_t *packet) {
1463	struct libtrace_eventobj_t event;
1464
1465	if (!trace) {
1466	fprintf(stderr,"You called trace_event() with a NULL trace object!\n");
1467	}
1468	assert(trace);
1469	assert(packet);
1470
1471	/* Store the trace we are reading from into the packet opaque
1472	* structure */
1473	packet->trace = trace;
1474
1475	/* Is there a packet ready? */
1476	switch (trace->sourcetype) {
1477	#if HAVE_PCAP
1478	case INTERFACE:
1479	{
1480	int data;
1481	event.fd = pcap_fileno(trace->input.pcap);
1482	if(ioctl(event.fd,FIONREAD,&data)==-1){
1483	perror("ioctl(FIONREAD)");
1484	}
1485	if (data>0) {
1486	event.size = trace_read_packet(trace,packet);
1487	event.type = TRACE_EVENT_PACKET;
1488	return event;
1489	}
1490	event.type = TRACE_EVENT_IOWAIT;
1491	return event;
1492	}
1493	#endif
1494	case SOCKET:
1495	case DEVICE:
1496	case RT:
1497	{
1498	int data;
1499	event.fd = trace->input.fd;
1500	if(ioctl(event.fd,FIONREAD,&data)==-1){
1501	perror("ioctl(FIONREAD)");
1502	}
1503	if (data>0) {
1504	event.size = trace_read_packet(trace,packet);
1505	event.type = TRACE_EVENT_PACKET;
1506	return event;
1507	}
1508	event.type = TRACE_EVENT_IOWAIT;
1509	return event;
1510	}
1511	case STDIN:
1512	case TRACE:
1513	{
1514	double ts;
1515	double now;
1516	struct timeval stv;
1517	/* "Prime" the pump */
1518	if (!trace->packet.buffer) {
1519	trace->packet.buffer = malloc(4096);
1520	trace->packet.size=
1521	trace_read_packet(trace,packet);
1522	event.size = trace->packet.size;
1523	if (trace->packet.size > 0 ) {
1524	memcpy(trace->packet.buffer,packet->buffer,trace->packet.size);
1525	} else {
1526	// return here, the test for event.size will sort out the error
1527	event.type = TRACE_EVENT_PACKET;
1528	return event;
1529	}
1530	}
1531
1532	ts=trace_get_seconds(packet);
1533	if (trace->tdelta!=0) {
1534	// Get the adjusted current time
1535	gettimeofday(&stv, NULL);
1536	now = stv.tv_sec + ((double)stv.tv_usec / 1000000.0);
1537	now -= trace->tdelta; // adjust for trace delta
1538
1539
1540	// if the trace timestamp is still in the future,
1541	// return a SLEEP event, otherwise fire the packet
1542	if (ts > now) {
1543	event.seconds = ts - trace->trace_last_ts;
1544	event.type = TRACE_EVENT_SLEEP;
1545	return event;
1546	}
1547	} else {
1548	gettimeofday(&stv, NULL);
1549	// work out the difference between the start of trace replay,
1550	// and the first packet in the trace
1551	trace->tdelta = stv.tv_sec + ((double)stv.tv_usec / 1000000.0);
1552	trace->tdelta -= ts;
1553
1554	}
1555
1556	// This is the first packet, so just fire away.
1557	packet->size = trace->packet.size;
1558	memcpy(packet->buffer,trace->packet.buffer,trace->packet.size);
1559
1560	free(trace->packet.buffer);
1561	trace->packet.buffer = 0;
1562	event.type = TRACE_EVENT_PACKET;
1563
1564	trace->trace_last_ts = ts;
1565
1566	return event;
1567	}
1568	default:
1569	assert(0);
1570	}
1571	assert(0);
1572	}
1573
1574	/** setup a BPF filter
1575	* @param filterstring a char * containing the bpf filter string
1576	* @returns opaque pointer pointer to a libtrace_filter_t object
1577	* @author Daniel Lawson
1578	*/
1579	struct libtrace_filter_t trace_bpf_setfilter(const char filterstring) {
1580	#if HAVE_BPF
1581	struct libtrace_filter_t *filter = malloc(sizeof(struct libtrace_filter_t));
1582	filter->filterstring = strdup(filterstring);
1583	filter->filter = 0;
1584	return filter;
1585	#else
1586	fprintf(stderr,"This version of libtrace does not have bpf filter support\n");
1587	return 0;
1588	#endif
1589	}
1590
1591	/** apply a BPF filter
1592	* @param filter the filter opaque pointer
1593	* @param packet the packet opaque pointer
1594	* @returns 0 if the filter fails, 1 if it succeeds
1595	* @author Daniel Lawson
1596	*/
1597	int trace_bpf_filter(struct libtrace_filter_t *filter,
1598	struct libtrace_packet_t *packet) {
1599	#if HAVE_BPF
1600	void *linkptr = 0;
1601	int clen = 0;
1602	assert(filter);
1603	assert(packet);
1604	linkptr = trace_get_link(packet);
1605	if (!linkptr) {
1606	return 0;
1607	}
1608
1609	clen = trace_get_capture_length(packet);
1610
1611
1612	if (filter->filterstring && ! filter->filter) {
1613	pcap_t *pcap;
1614	struct bpf_program bpfprog;
1615
1616	switch (trace_get_link_type(packet)) {
1617	case TRACE_TYPE_ETH:
1618	pcap = pcap_open_dead(DLT_EN10MB, 1500);
1619	break;
1620	case TRACE_TYPE_LINUX_SLL:
1621	pcap = pcap_open_dead(DLT_LINUX_SLL, 1500);
1622	break;
1623	default:
1624	printf("only works for ETH and LINUX_SLL (ppp) at the moment\n");
1625	assert(0);
1626	}
1627
1628	// build filter
1629	if (pcap_compile( pcap, &bpfprog, filter->filterstring, 1, 0)) {
1630	printf("bpf compilation error: %s\n",
1631	pcap_geterr(pcap));
1632	assert(0);
1633	}
1634	pcap_close(pcap);
1635	filter->filter = bpfprog.bf_insns;
1636	}
1637
1638	assert(filter->filter);
1639	return bpf_filter(filter->filter, linkptr, clen, clen);
1640	#else
1641	fprintf(stderr,"This version of libtrace does not have bpf filter support\n");
1642	return 0;
1643	#endif
1644	}
1645
1646	/** Set the direction flag, if it has one
1647	* @param packet the packet opaque pointer
1648	* @param direction the new direction (0,1,2,3)
1649	* @returns a signed value containing the direction flag, or -1 if this is not supported
1650	* @author Daniel Lawson
1651	*/
1652	int8_t trace_set_direction(struct libtrace_packet_t *packet, int8_t direction) {
1653
1654	dag_record_t *erfptr = 0;
1655	assert(packet);
1656
1657	switch(packet->trace->format) {
1658	case DAG:
1659	case ERF:
1660	case RTCLIENT:
1661	erfptr = (dag_record_t *)packet->buffer;
1662	erfptr->flags.iface = direction;
1663	break;
1664	default:
1665	direction = -1;
1666	}
1667
1668	return direction;
1669
1670
1671	}
1672
1673	/** Get the direction flag, if it has one
1674	* @param packet a pointer to a libtrace_packet structure
1675	* @returns a signed value containing the direction flag, or -1 if this is not supported
1676	* The direction is defined as 0 for packets originating locally (ie, outbound)
1677	* and 1 for packets originating remotely (ie, inbound).
1678	* Other values are possible, which might be overloaded to mean special things
1679	* for a special trace.
1680	* @author Daniel Lawson
1681	*/
1682	int8_t trace_get_direction(const struct libtrace_packet_t *packet) {
1683
1684	int8_t direction;
1685	dag_record_t *erfptr = 0;
1686	assert(packet);
1687	direction = -1;
1688
1689	switch(packet->trace->format) {
1690	case DAG:
1691	case ERF:
1692	case RTCLIENT:
1693	erfptr = (dag_record_t *)packet->buffer;
1694	direction = erfptr->flags.iface;
1695	break;
1696	case PCAP:
1697	case PCAPINT:
1698	switch (trace_get_link_type(packet)) {
1699	case TRACE_TYPE_LINUX_SLL:
1700	{
1701	struct trace_sll_header_t *sll;
1702	sll = trace_get_link(packet);
1703	if (!sll) {
1704	return -1;
1705	}
1706	/* 0 == LINUX_SLL_HOST */
1707	/* the Waikato Capture point defines "packets
1708	* originating locally" (ie, outbound), with a
1709	* direction of 0, and "packets destined locally"
1710	* (ie, inbound), with a direction of 1.
1711	* This is kind-of-opposite to LINUX_SLL.
1712	* We return consistent values here, however
1713	*
1714	* Note that in recent versions of pcap, you can
1715	* use "inbound" and "outbound" on ppp in linux
1716	*/
1717	if (ntohs(sll->pkttype==0)) {
1718
1719	direction = 1;
1720	}
1721	else {
1722	direction = 0;
1723	}
1724	break;
1725	}
1726	default:
1727	/* pass */
1728	break;
1729	}
1730	default:
1731	/* pass */
1732	break;
1733	}
1734
1735	return direction;
1736
1737
1738	}
1739
1740	#define ROOT_SERVER(x) ((x) < 512)
1741	#define ROOT_CLIENT(x) ((512 <= (x)) && ((x) < 1024))
1742	#define NONROOT_SERVER(x) ((x) >= 5000)
1743	#define NONROOT_CLIENT(x) ((1024 <= (x)) && ((x) < 5000))
1744	#define DYNAMIC(x) ((49152 < (x)) && ((x) < 65535))
1745	#define SERVER(x) ROOT_SERVER(x) \|\| NONROOT_SERVER(x)
1746	#define CLIENT(x) ROOT_CLIENT(x) \|\| NONROOT_CLIENT(x)
1747
1748
1749	/* Attempt to deduce the 'server' port
1750	* @param protocol the IP protocol (eg, 6 or 17 for TCP or UDP)
1751	* @param source the TCP or UDP source port
1752	* @param dest the TCP or UDP destination port
1753	* @returns a hint as to which port is the server port
1754	* @author Daniel Lawson
1755	*/
1756	int8_t trace_get_server_port(uint8_t protocol, uint16_t source, uint16_t dest) {
1757	/*
1758	* * If the ports are equal, return DEST
1759	* * Check for well-known ports in the given protocol
1760	* * Root server ports: 0 - 511
1761	* * Root client ports: 512 - 1023
1762	* * non-root client ports: 1024 - 4999
1763	* * non-root server ports: 5000+
1764	* * Check for static ranges: 1024 - 49151
1765	* * Check for dynamic ranges: 49152 - 65535
1766	* * flip a coin.
1767	*/
1768
1769	uint16_t server, client;
1770
1771	/* equal */
1772	if (source == client)
1773	return USE_DEST;
1774
1775	/* root server port, 0 - 511 */
1776	if (ROOT_SERVER(source) && ROOT_SERVER(dest)) {
1777	if (source < dest)
1778	return USE_SOURCE;
1779	return USE_DEST;
1780	}
1781
1782	if (ROOT_SERVER(source) && !ROOT_SERVER(dest))
1783	return USE_SOURCE;
1784	if (!ROOT_SERVER(source) && ROOT_SERVER(dest))
1785	return USE_DEST;
1786
1787	/* non-root server */
1788	if (NONROOT_SERVER(source) && NONROOT_SERVER(dest)) {
1789	if (source < dest)
1790	return USE_SOURCE;
1791	return USE_DEST;
1792	}
1793	if (NONROOT_SERVER(source) && !NONROOT_SERVER(dest))
1794	return USE_SOURCE;
1795	if (!NONROOT_SERVER(source) && NONROOT_SERVER(dest))
1796	return USE_DEST;
1797
1798	/* root client */
1799	if (ROOT_CLIENT(source) && ROOT_CLIENT(dest)) {
1800	if (source < dest)
1801	return USE_SOURCE;
1802	return USE_DEST;
1803	}
1804	if (ROOT_CLIENT(source) && !ROOT_CLIENT(dest)) {
1805	/* prefer root-client over nonroot-client */
1806	if (NONROOT_CLIENT(dest))
1807	return USE_SOURCE;
1808	return USE_DEST;
1809	}
1810	if (!ROOT_CLIENT(source) && ROOT_CLIENT(dest)) {
1811	/* prefer root-client over nonroot-client */
1812	if (NONROOT_CLIENT(source))
1813	return USE_DEST;
1814	return USE_SOURCE;
1815	}
1816
1817	/* nonroot client */
1818	if (NONROOT_CLIENT(source) && NONROOT_CLIENT(dest)) {
1819	if (source < dest)
1820	return USE_SOURCE;
1821	return USE_DEST;
1822	}
1823	if (NONROOT_CLIENT(source) && !NONROOT_CLIENT(dest))
1824	return USE_DEST;
1825	if (!NONROOT_CLIENT(source) && NONROOT_CLIENT(dest))
1826	return USE_SOURCE;
1827
1828	/* dynamic range */
1829	if (DYNAMIC(source) && DYNAMIC(dest))
1830	if (source < dest)
1831	return USE_SOURCE;
1832	return USE_DEST;
1833	if (DYNAMIC(source) && !DYNAMIC(dest))
1834	return USE_DEST;
1835	if (!DYNAMIC(source) && DYNAMIC(dest))
1836	return USE_SOURCE;
1837	/*
1838	if (SERVER(source) && CLIENT(dest))
1839	return USE_SOURCE;
1840
1841	if (SERVER(dest) && CLIENT(source))
1842	return USE_DEST;
1843	if (ROOT_SERVER(source) && !ROOT_SERVER(dest))
1844	return USE_SOURCE;
1845	if (ROOT_SERVER(dest) && !ROOT_SERVER(source))
1846	return USE_DEST;
1847	*/
1848	// failing that test...
1849	if (source < dest) {
1850	return USE_SOURCE;
1851	}
1852	return USE_DEST;
1853
1854	}
1855
1856	/** Truncate the packet at the suggested length
1857	* @param packet the packet opaque pointer
1858	* @param size the new length of the packet
1859	* @returns the new length of the packet, or the original length of the
1860	* packet if unchanged
1861	* NOTE: len refers to the network-level payload of the packet, and not
1862	* any capture headers included as well. For example, to truncate a packet
1863	* after the IP header, set scan to sizeof(ethernet_header) + sizeof(ip_header)
1864	* @author Daniel Lawson
1865	*/
1866	size_t trace_truncate_packet(struct libtrace_packet_t *packet, size_t size) {
1867	dag_record_t *erfptr;
1868	#if HAVE_PCAP
1869	struct pcap_pkthdr *pcaphdr;
1870	#endif
1871
1872	assert(packet);
1873
1874	if (size > packet->size) {
1875	// can't make a packet larger
1876	return packet->size;
1877	}
1878	switch (packet->trace->format) {
1879	#if HAVE_PCAP
1880	case PCAPINT:
1881	case PCAP:
1882	pcaphdr = (struct pcap_pkthdr *)packet->buffer;
1883	pcaphdr->caplen = size + sizeof(struct pcap_pkthdr);
1884	packet->size = pcaphdr->caplen;
1885	break;
1886	#endif
1887	case ERF:
1888	case DAG:
1889	case RTCLIENT:
1890	erfptr = (dag_record_t *)packet->buffer;
1891	erfptr->rlen = ntohs(size + sizeof(dag_record_t));
1892	packet->size = size + sizeof(dag_record_t);
1893	break;
1894	case WAGINT:
1895	case WAG:
1896	// don't know how to do this?
1897	break;
1898	}
1899	return packet->size;
1900	}
1901

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