pcap-snoop.c revision 56889 
1/*
2 * Copyright (c) 1993, 1994, 1995, 1996, 1997
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: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 */
21#ifndef lint
22static const char rcsid[] =
23    "@(#) $Header: /tcpdump/master/libpcap/pcap-snoop.c,v 1.20.1.1 1999/10/07 23:46:40 mcr Exp $ (LBL)";
24#endif
25
26#include <sys/param.h>
27#include <sys/file.h>
28#include <sys/ioctl.h>
29#include <sys/socket.h>
30#include <sys/time.h>
31
32#include <net/raw.h>
33#include <net/if.h>
34
35#include <netinet/in.h>
36#include <netinet/in_systm.h>
37#include <netinet/ip.h>
38#include <netinet/if_ether.h>
39#include <netinet/ip_var.h>
40#include <netinet/udp.h>
41#include <netinet/udp_var.h>
42#include <netinet/tcp.h>
43#include <netinet/tcpip.h>
44
45#include <errno.h>
46#include <stdio.h>
47#include <stdlib.h>
48#include <string.h>
49#include <unistd.h>
50
51#include "pcap-int.h"
52
53#include "gnuc.h"
54#ifdef HAVE_OS_PROTO_H
55#include "os-proto.h"
56#endif
57
58int
59pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
60{
61	int cc;
62	register struct snoopheader *sh;
63	register int datalen;
64	register int caplen;
65	register u_char *cp;
66
67again:
68	cc = read(p->fd, (char *)p->buffer, p->bufsize);
69	if (cc < 0) {
70		/* Don't choke when we get ptraced */
71		switch (errno) {
72
73		case EINTR:
74				goto again;
75
76		case EWOULDBLOCK:
77			return (0);			/* XXX */
78		}
79		sprintf(p->errbuf, "read: %s", pcap_strerror(errno));
80		return (-1);
81	}
82	sh = (struct snoopheader *)p->buffer;
83	datalen = sh->snoop_packetlen;
84	caplen = (datalen < p->snapshot) ? datalen : p->snapshot;
85	cp = (u_char *)(sh + 1) + p->offset;		/* XXX */
86
87	if (p->fcode.bf_insns == NULL ||
88	    bpf_filter(p->fcode.bf_insns, cp, datalen, caplen)) {
89		struct pcap_pkthdr h;
90		++p->md.stat.ps_recv;
91		h.ts = sh->snoop_timestamp;
92		h.len = datalen;
93		h.caplen = caplen;
94		(*callback)(user, &h, cp);
95		return (1);
96	}
97	return (0);
98}
99
100int
101pcap_stats(pcap_t *p, struct pcap_stat *ps)
102{
103	register struct rawstats *rs;
104	struct rawstats rawstats;
105
106	rs = &rawstats;
107	bzero((char *)rs, sizeof(*rs));
108	if (ioctl(p->fd, SIOCRAWSTATS, (char *)rs) < 0) {
109		sprintf(p->errbuf, "SIOCRAWSTATS: %s", pcap_strerror(errno));
110		return (-1);
111	}
112
113	p->md.stat.ps_drop =
114	    rs->rs_snoop.ss_ifdrops + rs->rs_snoop.ss_sbdrops +
115	    rs->rs_drain.ds_ifdrops + rs->rs_drain.ds_sbdrops;
116
117	*ps = p->md.stat;
118	return (0);
119}
120
121/* XXX can't disable promiscuous */
122pcap_t *
123pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
124{
125	int fd;
126	struct sockaddr_raw sr;
127	struct snoopfilter sf;
128	u_int v;
129	pcap_t *p;
130
131	p = (pcap_t *)malloc(sizeof(*p));
132	if (p == NULL) {
133		sprintf(ebuf, "malloc: %s", pcap_strerror(errno));
134		return (NULL);
135	}
136	bzero((char *)p, sizeof(*p));
137	fd = socket(PF_RAW, SOCK_RAW, RAWPROTO_SNOOP);
138	if (fd < 0) {
139		sprintf(ebuf, "snoop socket: %s", pcap_strerror(errno));
140		goto bad;
141	}
142	p->fd = fd;
143	bzero((char *)&sr, sizeof(sr));
144	sr.sr_family = AF_RAW;
145	(void)strncpy(sr.sr_ifname, device, sizeof(sr.sr_ifname));
146	if (bind(fd, (struct sockaddr *)&sr, sizeof(sr))) {
147		sprintf(ebuf, "snoop bind: %s", pcap_strerror(errno));
148		goto bad;
149	}
150	bzero((char *)&sf, sizeof(sf));
151	if (ioctl(fd, SIOCADDSNOOP, &sf) < 0) {
152		sprintf(ebuf, "SIOCADDSNOOP: %s", pcap_strerror(errno));
153		goto bad;
154	}
155	v = 64 * 1024;
156	(void)setsockopt(fd, SOL_SOCKET, SO_RCVBUF, (char *)&v, sizeof(v));
157	if (ioctl(fd, SIOCSNOOPLEN, &snaplen) < 0) {
158		sprintf(ebuf, "SIOCSNOOPLEN: %s", pcap_strerror(errno));
159		goto bad;
160	}
161	p->snapshot = snaplen;
162	v = 1;
163	if (ioctl(fd, SIOCSNOOPING, &v) < 0) {
164		sprintf(ebuf, "SIOCSNOOPING: %s", pcap_strerror(errno));
165		goto bad;
166	}
167	/*
168	 * XXX hack - map device name to link layer type
169	 */
170	if (strncmp("et", device, 2) == 0 ||	/* Challenge 10 Mbit */
171	    strncmp("ec", device, 2) == 0 ||	/* Indigo/Indy 10 Mbit,
172						   O2 10/100 */
173	    strncmp("ef", device, 2) == 0 ||	/* O200/2000 10/100 Mbit */
174	    strncmp("gfe", device, 3) == 0 ||	/* GIO 100 Mbit */
175	    strncmp("fxp", device, 3) == 0 ||	/* Challenge VME Enet */
176	    strncmp("ep", device, 2) == 0 ||	/* Challenge 8x10 Mbit EPLEX */
177	    strncmp("vfe", device, 3) == 0 ||	/* Challenge VME 100Mbit */
178	    strncmp("fa", device, 2) == 0 ||
179	    strncmp("qaa", device, 3) == 0) {
180		p->linktype = DLT_EN10MB;
181		p->offset = RAW_HDRPAD(sizeof(struct ether_header));
182	} else if (strncmp("ipg", device, 3) == 0 ||
183		   strncmp("rns", device, 3) == 0 ||	/* O2/200/2000 FDDI */
184		   strncmp("xpi", device, 3) == 0) {
185		p->linktype = DLT_FDDI;
186		p->offset = 3;				/* XXX yeah? */
187	} else if (strncmp("ppp", device, 3) == 0) {
188		p->linktype = DLT_RAW;
189	} else if (strncmp("lo", device, 2) == 0) {
190		p->linktype = DLT_NULL;
191	} else {
192		sprintf(ebuf, "snoop: unknown physical layer type");
193		goto bad;
194	}
195
196	p->bufsize = 4096;				/* XXX */
197	p->buffer = (u_char *)malloc(p->bufsize);
198	if (p->buffer == NULL) {
199		sprintf(ebuf, "malloc: %s", pcap_strerror(errno));
200		goto bad;
201	}
202
203	return (p);
204 bad:
205	(void)close(fd);
206	free(p);
207	return (NULL);
208}
209
210int
211pcap_setfilter(pcap_t *p, struct bpf_program *fp)
212{
213
214	p->fcode = *fp;
215	return (0);
216}
217