pcap-nit.c revision 75107 
1/*
2 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996
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-nit.c,v 1.39 2000/10/28 00:01:29 guy Exp $ (LBL)";
24#endif
25
26#ifdef HAVE_CONFIG_H
27#include "config.h"
28#endif
29
30#include <sys/types.h>
31#include <sys/time.h>
32#include <sys/timeb.h>
33#include <sys/file.h>
34#include <sys/ioctl.h>
35#include <sys/socket.h>
36
37#include <net/if.h>
38#include <net/nit.h>
39
40#include <netinet/in.h>
41#include <netinet/in_systm.h>
42#include <netinet/ip.h>
43#include <netinet/if_ether.h>
44#include <netinet/ip_var.h>
45#include <netinet/udp.h>
46#include <netinet/udp_var.h>
47#include <netinet/tcp.h>
48#include <netinet/tcpip.h>
49
50#include <ctype.h>
51#include <errno.h>
52#include <stdio.h>
53
54#include "pcap-int.h"
55
56#ifdef HAVE_OS_PROTO_H
57#include "os-proto.h"
58#endif
59
60/*
61 * The chunk size for NIT.  This is the amount of buffering
62 * done for read calls.
63 */
64#define CHUNKSIZE (2*1024)
65
66/*
67 * The total buffer space used by NIT.
68 */
69#define BUFSPACE (4*CHUNKSIZE)
70
71/* Forwards */
72static int nit_setflags(int, int, int, char *);
73
74int
75pcap_stats(pcap_t *p, struct pcap_stat *ps)
76{
77
78	*ps = p->md.stat;
79	return (0);
80}
81
82int
83pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
84{
85	register int cc, n;
86	register struct bpf_insn *fcode = p->fcode.bf_insns;
87	register u_char *bp, *cp, *ep;
88	register struct nit_hdr *nh;
89	register int caplen;
90
91	cc = p->cc;
92	if (cc == 0) {
93		cc = read(p->fd, (char *)p->buffer, p->bufsize);
94		if (cc < 0) {
95			if (errno == EWOULDBLOCK)
96				return (0);
97			snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
98				pcap_strerror(errno));
99			return (-1);
100		}
101		bp = p->buffer;
102	} else
103		bp = p->bp;
104
105	/*
106	 * Loop through each packet.  The increment expression
107	 * rounds up to the next int boundary past the end of
108	 * the previous packet.
109	 */
110	n = 0;
111	ep = bp + cc;
112	while (bp < ep) {
113		nh = (struct nit_hdr *)bp;
114		cp = bp + sizeof(*nh);
115
116		switch (nh->nh_state) {
117
118		case NIT_CATCH:
119			break;
120
121		case NIT_NOMBUF:
122		case NIT_NOCLUSTER:
123		case NIT_NOSPACE:
124			p->md.stat.ps_drop = nh->nh_dropped;
125			continue;
126
127		case NIT_SEQNO:
128			continue;
129
130		default:
131			snprintf(p->errbuf, sizeof(p->errbuf),
132			    "bad nit state %d", nh->nh_state);
133			return (-1);
134		}
135		++p->md.stat.ps_recv;
136		bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
137		    sizeof(int) - 1) & ~(sizeof(int) - 1));
138
139		caplen = nh->nh_wirelen;
140		if (caplen > p->snapshot)
141			caplen = p->snapshot;
142		if (bpf_filter(fcode, cp, nh->nh_wirelen, caplen)) {
143			struct pcap_pkthdr h;
144			h.ts = nh->nh_timestamp;
145			h.len = nh->nh_wirelen;
146			h.caplen = caplen;
147			(*callback)(user, &h, cp);
148			if (++n >= cnt && cnt >= 0) {
149				p->cc = ep - bp;
150				p->bp = bp;
151				return (n);
152			}
153		}
154	}
155	p->cc = 0;
156	return (n);
157}
158
159static int
160nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
161{
162	struct nit_ioc nioc;
163
164	memset(&nioc, 0, sizeof(nioc));
165	nioc.nioc_bufspace = BUFSPACE;
166	nioc.nioc_chunksize = CHUNKSIZE;
167	nioc.nioc_typetomatch = NT_ALLTYPES;
168	nioc.nioc_snaplen = p->snapshot;
169	nioc.nioc_bufalign = sizeof(int);
170	nioc.nioc_bufoffset = 0;
171
172	if (to_ms != 0) {
173		nioc.nioc_flags |= NF_TIMEOUT;
174		nioc.nioc_timeout.tv_sec = to_ms / 1000;
175		nioc.nioc_timeout.tv_usec = (to_ms * 1000) % 1000000;
176	}
177	if (promisc)
178		nioc.nioc_flags |= NF_PROMISC;
179
180	if (ioctl(fd, SIOCSNIT, &nioc) < 0) {
181		snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s",
182		    pcap_strerror(errno));
183		return (-1);
184	}
185	return (0);
186}
187
188pcap_t *
189pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
190{
191	int fd;
192	struct sockaddr_nit snit;
193	register pcap_t *p;
194
195	p = (pcap_t *)malloc(sizeof(*p));
196	if (p == NULL) {
197		strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
198		return (NULL);
199	}
200
201	if (snaplen < 96)
202		/*
203		 * NIT requires a snapshot length of at least 96.
204		 */
205		snaplen = 96;
206
207	memset(p, 0, sizeof(*p));
208	p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
209	if (fd < 0) {
210		snprintf(ebuf, PCAP_ERRBUF_SIZE,
211		    "socket: %s", pcap_strerror(errno));
212		goto bad;
213	}
214	snit.snit_family = AF_NIT;
215	(void)strncpy(snit.snit_ifname, device, NITIFSIZ);
216
217	if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
218		snprintf(ebuf, PCAP_ERRBUF_SIZE,
219		    "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno));
220		goto bad;
221	}
222	p->snapshot = snaplen;
223	nit_setflags(p->fd, promisc, to_ms, ebuf);
224
225	/*
226	 * NIT supports only ethernets.
227	 */
228	p->linktype = DLT_EN10MB;
229
230	p->bufsize = BUFSPACE;
231	p->buffer = (u_char *)malloc(p->bufsize);
232	if (p->buffer == NULL) {
233		strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
234		goto bad;
235	}
236	return (p);
237 bad:
238	if (fd >= 0)
239		close(fd);
240	free(p);
241	return (NULL);
242}
243
244int
245pcap_setfilter(pcap_t *p, struct bpf_program *fp)
246{
247
248	if (install_bpf_program(p, fp) < 0)
249		return (-1);
250	return (0);
251}
252