pcap-snit.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 * Modifications made to accommodate the new SunOS4.0 NIT facility by
22 * Micky Liu, micky@cunixc.cc.columbia.edu, Columbia University in May, 1989.
23 * This module now handles the STREAMS based NIT.
24 */
25
26#ifndef lint
27static const char rcsid[] =
28    "@(#) $Header: /tcpdump/master/libpcap/pcap-snit.c,v 1.54 2000/10/28 00:01:30 guy Exp $ (LBL)";
29#endif
30
31#ifdef HAVE_CONFIG_H
32#include "config.h"
33#endif
34
35#include <sys/types.h>
36#include <sys/time.h>
37#include <sys/timeb.h>
38#include <sys/dir.h>
39#include <sys/fcntlcom.h>
40#include <sys/file.h>
41#include <sys/ioctl.h>
42#include <sys/socket.h>
43#include <sys/stropts.h>
44
45#include <net/if.h>
46#include <net/nit.h>
47#include <net/nit_if.h>
48#include <net/nit_pf.h>
49#include <net/nit_buf.h>
50
51#include <netinet/in.h>
52#include <netinet/in_systm.h>
53#include <netinet/ip.h>
54#include <netinet/if_ether.h>
55#include <netinet/ip_var.h>
56#include <netinet/udp.h>
57#include <netinet/udp_var.h>
58#include <netinet/tcp.h>
59#include <netinet/tcpip.h>
60
61#include <ctype.h>
62#include <errno.h>
63#include <stdio.h>
64#include <string.h>
65#include <unistd.h>
66
67#include "pcap-int.h"
68
69#ifdef HAVE_OS_PROTO_H
70#include "os-proto.h"
71#endif
72
73/*
74 * The chunk size for NIT.  This is the amount of buffering
75 * done for read calls.
76 */
77#define CHUNKSIZE (2*1024)
78
79/*
80 * The total buffer space used by NIT.
81 */
82#define BUFSPACE (4*CHUNKSIZE)
83
84/* Forwards */
85static int nit_setflags(int, int, int, char *);
86
87int
88pcap_stats(pcap_t *p, struct pcap_stat *ps)
89{
90
91	*ps = p->md.stat;
92	return (0);
93}
94
95int
96pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
97{
98	register int cc, n;
99	register struct bpf_insn *fcode = p->fcode.bf_insns;
100	register u_char *bp, *cp, *ep;
101	register struct nit_bufhdr *hdrp;
102	register struct nit_iftime *ntp;
103	register struct nit_iflen *nlp;
104	register struct nit_ifdrops *ndp;
105	register int caplen;
106
107	cc = p->cc;
108	if (cc == 0) {
109		cc = read(p->fd, (char *)p->buffer, p->bufsize);
110		if (cc < 0) {
111			if (errno == EWOULDBLOCK)
112				return (0);
113			snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
114				pcap_strerror(errno));
115			return (-1);
116		}
117		bp = p->buffer;
118	} else
119		bp = p->bp;
120
121	/*
122	 * loop through each snapshot in the chunk
123	 */
124	n = 0;
125	ep = bp + cc;
126	while (bp < ep) {
127		++p->md.stat.ps_recv;
128		cp = bp;
129
130		/* get past NIT buffer  */
131		hdrp = (struct nit_bufhdr *)cp;
132		cp += sizeof(*hdrp);
133
134		/* get past NIT timer   */
135		ntp = (struct nit_iftime *)cp;
136		cp += sizeof(*ntp);
137
138		ndp = (struct nit_ifdrops *)cp;
139		p->md.stat.ps_drop = ndp->nh_drops;
140		cp += sizeof *ndp;
141
142		/* get past packet len  */
143		nlp = (struct nit_iflen *)cp;
144		cp += sizeof(*nlp);
145
146		/* next snapshot        */
147		bp += hdrp->nhb_totlen;
148
149		caplen = nlp->nh_pktlen;
150		if (caplen > p->snapshot)
151			caplen = p->snapshot;
152
153		if (bpf_filter(fcode, cp, nlp->nh_pktlen, caplen)) {
154			struct pcap_pkthdr h;
155			h.ts = ntp->nh_timestamp;
156			h.len = nlp->nh_pktlen;
157			h.caplen = caplen;
158			(*callback)(user, &h, cp);
159			if (++n >= cnt && cnt >= 0) {
160				p->cc = ep - bp;
161				p->bp = bp;
162				return (n);
163			}
164		}
165	}
166	p->cc = 0;
167	return (n);
168}
169
170static int
171nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
172{
173	bpf_u_int32 flags;
174	struct strioctl si;
175	struct timeval timeout;
176
177	si.ic_timout = INFTIM;
178	if (to_ms != 0) {
179		timeout.tv_sec = to_ms / 1000;
180		timeout.tv_usec = (to_ms * 1000) % 1000000;
181		si.ic_cmd = NIOCSTIME;
182		si.ic_len = sizeof(timeout);
183		si.ic_dp = (char *)&timeout;
184		if (ioctl(fd, I_STR, (char *)&si) < 0) {
185			snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSTIME: %s",
186			    pcap_strerror(errno));
187			return (-1);
188		}
189	}
190	flags = NI_TIMESTAMP | NI_LEN | NI_DROPS;
191	if (promisc)
192		flags |= NI_PROMISC;
193	si.ic_cmd = NIOCSFLAGS;
194	si.ic_len = sizeof(flags);
195	si.ic_dp = (char *)&flags;
196	if (ioctl(fd, I_STR, (char *)&si) < 0) {
197		snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSFLAGS: %s",
198		    pcap_strerror(errno));
199		return (-1);
200	}
201	return (0);
202}
203
204pcap_t *
205pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
206{
207	struct strioctl si;		/* struct for ioctl() */
208	struct ifreq ifr;		/* interface request struct */
209	int chunksize = CHUNKSIZE;
210	int fd;
211	static char dev[] = "/dev/nit";
212	register pcap_t *p;
213
214	p = (pcap_t *)malloc(sizeof(*p));
215	if (p == NULL) {
216		strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
217		return (NULL);
218	}
219
220	if (snaplen < 96)
221		/*
222		 * NIT requires a snapshot length of at least 96.
223		 */
224		snaplen = 96;
225
226	memset(p, 0, sizeof(*p));
227	p->fd = fd = open(dev, O_RDONLY);
228	if (fd < 0) {
229		snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s", dev,
230		    pcap_strerror(errno));
231		goto bad;
232	}
233
234	/* arrange to get discrete messages from the STREAM and use NIT_BUF */
235	if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
236		snprintf(ebuf, PCAP_ERRBUF_SIZE, "I_SRDOPT: %s",
237		    pcap_strerror(errno));
238		goto bad;
239	}
240	if (ioctl(fd, I_PUSH, "nbuf") < 0) {
241		snprintf(ebuf, PCAP_ERRBUF_SIZE, "push nbuf: %s",
242		    pcap_strerror(errno));
243		goto bad;
244	}
245	/* set the chunksize */
246	si.ic_cmd = NIOCSCHUNK;
247	si.ic_timout = INFTIM;
248	si.ic_len = sizeof(chunksize);
249	si.ic_dp = (char *)&chunksize;
250	if (ioctl(fd, I_STR, (char *)&si) < 0) {
251		snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSCHUNK: %s",
252		    pcap_strerror(errno));
253		goto bad;
254	}
255
256	/* request the interface */
257	strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
258	ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = ' ';
259	si.ic_cmd = NIOCBIND;
260	si.ic_len = sizeof(ifr);
261	si.ic_dp = (char *)&ifr;
262	if (ioctl(fd, I_STR, (char *)&si) < 0) {
263		snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCBIND: %s: %s",
264			ifr.ifr_name, pcap_strerror(errno));
265		goto bad;
266	}
267
268	/* set the snapshot length */
269	si.ic_cmd = NIOCSSNAP;
270	si.ic_len = sizeof(snaplen);
271	si.ic_dp = (char *)&snaplen;
272	if (ioctl(fd, I_STR, (char *)&si) < 0) {
273		snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSSNAP: %s",
274		    pcap_strerror(errno));
275		goto bad;
276	}
277	p->snapshot = snaplen;
278	if (nit_setflags(p->fd, promisc, to_ms, ebuf) < 0)
279		goto bad;
280
281	(void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
282	/*
283	 * NIT supports only ethernets.
284	 */
285	p->linktype = DLT_EN10MB;
286
287	p->bufsize = BUFSPACE;
288	p->buffer = (u_char *)malloc(p->bufsize);
289	if (p->buffer == NULL) {
290		strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
291		goto bad;
292	}
293	return (p);
294 bad:
295	if (fd >= 0)
296		close(fd);
297	free(p);
298	return (NULL);
299}
300
301int
302pcap_setfilter(pcap_t *p, struct bpf_program *fp)
303{
304
305	if (install_bpf_program(p, fp) < 0)
306		return (-1);
307	return (0);
308}
309