pcap-snit.c revision 26175 
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: pcap-snit.c,v 1.45 96/12/10 23:15:01 leres Exp $ (LBL)";
29#endif
30
31#include <sys/types.h>
32#include <sys/time.h>
33#include <sys/timeb.h>
34#include <sys/dir.h>
35#include <sys/fcntlcom.h>
36#include <sys/file.h>
37#include <sys/ioctl.h>
38#include <sys/socket.h>
39#include <sys/stropts.h>
40
41#include <net/if.h>
42#include <net/nit.h>
43#include <net/nit_if.h>
44#include <net/nit_pf.h>
45#include <net/nit_buf.h>
46
47#include <netinet/in.h>
48#include <netinet/in_systm.h>
49#include <netinet/ip.h>
50#include <netinet/if_ether.h>
51#include <netinet/ip_var.h>
52#include <netinet/udp.h>
53#include <netinet/udp_var.h>
54#include <netinet/tcp.h>
55#include <netinet/tcpip.h>
56
57#include <ctype.h>
58#include <errno.h>
59#ifdef HAVE_MALLOC_H
60#include <malloc.h>
61#endif
62#include <stdio.h>
63#include <string.h>
64#include <unistd.h>
65
66#include "pcap-int.h"
67
68#include "gnuc.h"
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			sprintf(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			sprintf(ebuf, "NIOCSTIME: %s", pcap_strerror(errno));
186			return (-1);
187		}
188	}
189	flags = NI_TIMESTAMP | NI_LEN | NI_DROPS;
190	if (promisc)
191		flags |= NI_PROMISC;
192	si.ic_cmd = NIOCSFLAGS;
193	si.ic_len = sizeof(flags);
194	si.ic_dp = (char *)&flags;
195	if (ioctl(fd, I_STR, (char *)&si) < 0) {
196		sprintf(ebuf, "NIOCSFLAGS: %s", pcap_strerror(errno));
197		return (-1);
198	}
199	return (0);
200}
201
202pcap_t *
203pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
204{
205	struct strioctl si;		/* struct for ioctl() */
206	struct ifreq ifr;		/* interface request struct */
207	int chunksize = CHUNKSIZE;
208	int fd;
209	static char dev[] = "/dev/nit";
210	register pcap_t *p;
211
212	p = (pcap_t *)malloc(sizeof(*p));
213	if (p == NULL) {
214		strcpy(ebuf, pcap_strerror(errno));
215		return (NULL);
216	}
217
218	if (snaplen < 96)
219		/*
220		 * NIT requires a snapshot length of at least 96.
221		 */
222		snaplen = 96;
223
224	bzero(p, sizeof(*p));
225	p->fd = fd = open(dev, O_RDONLY);
226	if (fd < 0) {
227		sprintf(ebuf, "%s: %s", dev, pcap_strerror(errno));
228		goto bad;
229	}
230
231	/* arrange to get discrete messages from the STREAM and use NIT_BUF */
232	if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
233		sprintf(ebuf, "I_SRDOPT: %s", pcap_strerror(errno));
234		goto bad;
235	}
236	if (ioctl(fd, I_PUSH, "nbuf") < 0) {
237		sprintf(ebuf, "push nbuf: %s", pcap_strerror(errno));
238		goto bad;
239	}
240	/* set the chunksize */
241	si.ic_cmd = NIOCSCHUNK;
242	si.ic_timout = INFTIM;
243	si.ic_len = sizeof(chunksize);
244	si.ic_dp = (char *)&chunksize;
245	if (ioctl(fd, I_STR, (char *)&si) < 0) {
246		sprintf(ebuf, "NIOCSCHUNK: %s", pcap_strerror(errno));
247		goto bad;
248	}
249
250	/* request the interface */
251	strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
252	ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = ' ';
253	si.ic_cmd = NIOCBIND;
254	si.ic_len = sizeof(ifr);
255	si.ic_dp = (char *)&ifr;
256	if (ioctl(fd, I_STR, (char *)&si) < 0) {
257		sprintf(ebuf, "NIOCBIND: %s: %s",
258			ifr.ifr_name, pcap_strerror(errno));
259		goto bad;
260	}
261
262	/* set the snapshot length */
263	si.ic_cmd = NIOCSSNAP;
264	si.ic_len = sizeof(snaplen);
265	si.ic_dp = (char *)&snaplen;
266	if (ioctl(fd, I_STR, (char *)&si) < 0) {
267		sprintf(ebuf, "NIOCSSNAP: %s", pcap_strerror(errno));
268		goto bad;
269	}
270	p->snapshot = snaplen;
271	if (nit_setflags(p->fd, promisc, to_ms, ebuf) < 0)
272		goto bad;
273
274	(void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
275	/*
276	 * NIT supports only ethernets.
277	 */
278	p->linktype = DLT_EN10MB;
279
280	p->bufsize = BUFSPACE;
281	p->buffer = (u_char *)malloc(p->bufsize);
282	if (p->buffer == NULL) {
283		strcpy(ebuf, pcap_strerror(errno));
284		goto bad;
285	}
286	return (p);
287 bad:
288	if (fd >= 0)
289		close(fd);
290	free(p);
291	return (NULL);
292}
293
294int
295pcap_setfilter(pcap_t *p, struct bpf_program *fp)
296{
297
298	p->fcode = *fp;
299	return (0);
300}
301