pcap.c revision 39291 
1/*
2 * Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the Computer Systems
16 *	Engineering Group at Lawrence Berkeley Laboratory.
17 * 4. Neither the name of the University nor of the Laboratory may be used
18 *    to endorse or promote products derived from this software without
19 *    specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static const char rcsid[] =
36    "@(#) $Header: pcap.c,v 1.29 98/07/12 13:15:39 leres Exp $ (LBL)";
37#endif
38
39#include <sys/types.h>
40
41#include <stdio.h>
42#include <stdlib.h>
43#include <string.h>
44#include <unistd.h>
45
46#include "gnuc.h"
47#ifdef HAVE_OS_PROTO_H
48#include "os-proto.h"
49#endif
50
51#include "pcap-int.h"
52
53int
54pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
55{
56
57	if (p->sf.rfile != NULL)
58		return (pcap_offline_read(p, cnt, callback, user));
59	return (pcap_read(p, cnt, callback, user));
60}
61
62int
63pcap_loop(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
64{
65	register int n;
66
67	for (;;) {
68		if (p->sf.rfile != NULL)
69			n = pcap_offline_read(p, cnt, callback, user);
70		else {
71			/*
72			 * XXX keep reading until we get something
73			 * (or an error occurs)
74			 */
75			do {
76				n = pcap_read(p, cnt, callback, user);
77			} while (n == 0);
78		}
79		if (n <= 0)
80			return (n);
81		if (cnt > 0) {
82			cnt -= n;
83			if (cnt <= 0)
84				return (0);
85		}
86	}
87}
88
89struct singleton {
90	struct pcap_pkthdr *hdr;
91	const u_char *pkt;
92};
93
94
95static void
96pcap_oneshot(u_char *userData, const struct pcap_pkthdr *h, const u_char *pkt)
97{
98	struct singleton *sp = (struct singleton *)userData;
99	*sp->hdr = *h;
100	sp->pkt = pkt;
101}
102
103const u_char *
104pcap_next(pcap_t *p, struct pcap_pkthdr *h)
105{
106	struct singleton s;
107
108	s.hdr = h;
109	if (pcap_dispatch(p, 1, pcap_oneshot, (u_char*)&s) <= 0)
110		return (0);
111	return (s.pkt);
112}
113
114int
115pcap_datalink(pcap_t *p)
116{
117	return (p->linktype);
118}
119
120int
121pcap_snapshot(pcap_t *p)
122{
123	return (p->snapshot);
124}
125
126int
127pcap_is_swapped(pcap_t *p)
128{
129	return (p->sf.swapped);
130}
131
132int
133pcap_major_version(pcap_t *p)
134{
135	return (p->sf.version_major);
136}
137
138int
139pcap_minor_version(pcap_t *p)
140{
141	return (p->sf.version_minor);
142}
143
144FILE *
145pcap_file(pcap_t *p)
146{
147	return (p->sf.rfile);
148}
149
150int
151pcap_fileno(pcap_t *p)
152{
153	return (p->fd);
154}
155
156void
157pcap_perror(pcap_t *p, char *prefix)
158{
159	fprintf(stderr, "%s: %s\n", prefix, p->errbuf);
160}
161
162char *
163pcap_geterr(pcap_t *p)
164{
165	return (p->errbuf);
166}
167
168/*
169 * Not all systems have strerror().
170 */
171char *
172pcap_strerror(int errnum)
173{
174#ifdef HAVE_STRERROR
175	return (strerror(errnum));
176#else
177	extern int sys_nerr;
178	extern const char *const sys_errlist[];
179	static char ebuf[20];
180
181	if ((unsigned int)errnum < sys_nerr)
182		return ((char *)sys_errlist[errnum]);
183	(void)sprintf(ebuf, "Unknown error: %d", errnum);
184	return(ebuf);
185#endif
186}
187
188void
189pcap_close(pcap_t *p)
190{
191	/*XXX*/
192	if (p->fd >= 0)
193		close(p->fd);
194	if (p->sf.rfile != NULL) {
195		(void)fclose(p->sf.rfile);
196		if (p->sf.base != NULL)
197			free(p->sf.base);
198	} else if (p->buffer != NULL)
199		free(p->buffer);
200#ifdef linux
201	if (p->md.device != NULL)
202		free(p->md.device);
203#endif
204
205	free(p);
206}
207