pcap-nit.c revision 17683 
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  char rcsid[] =
23    "@(#)$Header: pcap-nit.c,v 1.29 96/07/15 00:48:51 leres Exp $ (LBL)";
24#endif
25
26#include <sys/types.h>
27#include <sys/time.h>
28#include <sys/timeb.h>
29#include <sys/file.h>
30#include <sys/ioctl.h>
31#include <sys/socket.h>
32
33#include <net/if.h>
34#include <net/nit.h>
35
36#include <netinet/in.h>
37#include <netinet/in_systm.h>
38#include <netinet/ip.h>
39#include <netinet/if_ether.h>
40#include <netinet/ip_var.h>
41#include <netinet/udp.h>
42#include <netinet/udp_var.h>
43#include <netinet/tcp.h>
44#include <netinet/tcpip.h>
45
46#include <ctype.h>
47#include <errno.h>
48#include <stdio.h>
49
50#include "pcap-int.h"
51
52#include "gnuc.h"
53#ifdef HAVE_OS_PROTO_H
54#include "os-proto.h"
55#endif
56
57/*
58 * The chunk size for NIT.  This is the amount of buffering
59 * done for read calls.
60 */
61#define CHUNKSIZE (2*1024)
62
63/*
64 * The total buffer space used by NIT.
65 */
66#define BUFSPACE (4*CHUNKSIZE)
67
68/* Forwards */
69static int nit_setflags(int, int, int, char *);
70
71int
72pcap_stats(pcap_t *p, struct pcap_stat *ps)
73{
74
75	*ps = p->md.stat;
76	return (0);
77}
78
79int
80pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
81{
82	register int cc, n;
83	register struct bpf_insn *fcode = p->fcode.bf_insns;
84	register u_char *bp, *cp, *ep;
85	register struct nit_hdr *nh;
86	register int caplen;
87
88	cc = p->cc;
89	if (cc == 0) {
90		cc = read(p->fd, (char *)p->buffer, p->bufsize);
91		if (cc < 0) {
92			if (errno == EWOULDBLOCK)
93				return (0);
94			sprintf(p->errbuf, "pcap_read: %s",
95				pcap_strerror(errno));
96			return (-1);
97		}
98		bp = p->buffer;
99	} else
100		bp = p->bp;
101
102	/*
103	 * Loop through each packet.  The increment expression
104	 * rounds up to the next int boundary past the end of
105	 * the previous packet.
106	 */
107	n = 0;
108	ep = bp + cc;
109	while (bp < ep) {
110		nh = (struct nit_hdr *)bp;
111		cp = bp + sizeof(*nh);
112
113		switch (nh->nh_state) {
114
115		case NIT_CATCH:
116			break;
117
118		case NIT_NOMBUF:
119		case NIT_NOCLUSTER:
120		case NIT_NOSPACE:
121			p->md.stat.ps_drop = nh->nh_dropped;
122			continue;
123
124		case NIT_SEQNO:
125			continue;
126
127		default:
128			sprintf(p->errbuf, "bad nit state %d", nh->nh_state);
129			return (-1);
130		}
131		++p->md.stat.ps_recv;
132		bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
133		    sizeof(int) - 1) & ~(sizeof(int) - 1));
134
135		caplen = nh->nh_wirelen;
136		if (caplen > p->snapshot)
137			caplen = p->snapshot;
138		if (bpf_filter(fcode, cp, nh->nh_wirelen, caplen)) {
139			struct pcap_pkthdr h;
140			h.ts = nh->nh_timestamp;
141			h.len = nh->nh_wirelen;
142			h.caplen = caplen;
143			(*callback)(user, &h, cp);
144			if (++n >= cnt && cnt >= 0) {
145				p->cc = ep - bp;
146				p->bp = bp;
147				return (n);
148			}
149		}
150	}
151	p->cc = 0;
152	return (n);
153}
154
155static int
156nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
157{
158	struct nit_ioc nioc;
159
160	bzero((char *)&nioc, sizeof(nioc));
161	nioc.nioc_bufspace = BUFSPACE;
162	nioc.nioc_chunksize = CHUNKSIZE;
163	nioc.nioc_typetomatch = NT_ALLTYPES;
164	nioc.nioc_snaplen = p->snapshot;
165	nioc.nioc_bufalign = sizeof(int);
166	nioc.nioc_bufoffset = 0;
167
168	if (to_ms != 0) {
169		nioc.nioc_flags |= NF_TIMEOUT;
170		nioc.nioc_timeout.tv_sec = to_ms / 1000;
171		nioc.nioc_timeout.tv_usec = (to_ms * 1000) % 1000000;
172	}
173	if (promisc)
174		nioc.nioc_flags |= NF_PROMISC;
175
176	if (ioctl(fd, SIOCSNIT, &nioc) < 0) {
177		sprintf(ebuf, "SIOCSNIT: %s", pcap_strerror(errno));
178		return (-1);
179	}
180	return (0);
181}
182
183pcap_t *
184pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
185{
186	int fd;
187	struct sockaddr_nit snit;
188	register pcap_t *p;
189
190	p = (pcap_t *)malloc(sizeof(*p));
191	if (p == NULL) {
192		strcpy(ebuf, pcap_strerror(errno));
193		return (NULL);
194	}
195
196	if (snaplen < 96)
197		/*
198		 * NIT requires a snapshot length of at least 96.
199		 */
200		snaplen = 96;
201
202	bzero(p, sizeof(*p));
203	p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
204	if (fd < 0) {
205		sprintf(ebuf, "socket: %s", pcap_strerror(errno));
206		goto bad;
207	}
208	snit.snit_family = AF_NIT;
209	(void)strncpy(snit.snit_ifname, device, NITIFSIZ);
210
211	if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
212		sprintf(ebuf, "bind: %s: %s", snit.snit_ifname,
213			pcap_strerror(errno));
214		goto bad;
215	}
216	p->snapshot = snaplen;
217	nit_setflags(p->fd, promisc, to_ms, ebuf);
218
219	/*
220	 * NIT supports only ethernets.
221	 */
222	p->linktype = DLT_EN10MB;
223
224	p->bufsize = BUFSPACE;
225	p->buffer = (u_char *)malloc(p->bufsize);
226	if (p->buffer == NULL) {
227		strcpy(ebuf, pcap_strerror(errno));
228		goto bad;
229	}
230	return (p);
231 bad:
232	if (fd >= 0)
233		close(fd);
234	free(p);
235	return (NULL);
236}
237
238int
239pcap_setfilter(pcap_t *p, struct bpf_program *fp)
240{
241
242	p->fcode = *fp;
243	return (0);
244}
245