xref: /freebsd/contrib/libpcap/pcap-snit.c (revision e627b39baccd1ec9129690167cf5e6d860509655)
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
22 static  char rcsid[] =
23     "@(#)$Header: pcap-snit.c,v 1.42 96/07/15 00:48:51 leres Exp $ (LBL)";
24 #endif
25 
26 /*
27  * Modifications made to accommodate the new SunOS4.0 NIT facility by
28  * Micky Liu, micky@cunixc.cc.columbia.edu, Columbia University in May, 1989.
29  * This module now handles the STREAMS based NIT.
30  */
31 
32 #include <sys/types.h>
33 #include <sys/time.h>
34 #include <sys/timeb.h>
35 #include <sys/dir.h>
36 #include <sys/fcntlcom.h>
37 #include <sys/file.h>
38 #include <sys/ioctl.h>
39 #include <sys/socket.h>
40 #include <sys/stropts.h>
41 
42 #include <net/if.h>
43 #include <net/nit.h>
44 #include <net/nit_if.h>
45 #include <net/nit_pf.h>
46 #include <net/nit_buf.h>
47 
48 #include <netinet/in.h>
49 #include <netinet/in_systm.h>
50 #include <netinet/ip.h>
51 #include <netinet/if_ether.h>
52 #include <netinet/ip_var.h>
53 #include <netinet/udp.h>
54 #include <netinet/udp_var.h>
55 #include <netinet/tcp.h>
56 #include <netinet/tcpip.h>
57 
58 #include <ctype.h>
59 #include <errno.h>
60 #ifdef HAVE_MALLOC_H
61 #include <malloc.h>
62 #endif
63 #include <stdio.h>
64 #include <string.h>
65 #include <unistd.h>
66 
67 #include "pcap-int.h"
68 
69 #include "gnuc.h"
70 #ifdef HAVE_OS_PROTO_H
71 #include "os-proto.h"
72 #endif
73 
74 /*
75  * The chunk size for NIT.  This is the amount of buffering
76  * done for read calls.
77  */
78 #define CHUNKSIZE (2*1024)
79 
80 /*
81  * The total buffer space used by NIT.
82  */
83 #define BUFSPACE (4*CHUNKSIZE)
84 
85 /* Forwards */
86 static int nit_setflags(int, int, int, char *);
87 
88 int
89 pcap_stats(pcap_t *p, struct pcap_stat *ps)
90 {
91 
92 	*ps = p->md.stat;
93 	return (0);
94 }
95 
96 int
97 pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
98 {
99 	register int cc, n;
100 	register struct bpf_insn *fcode = p->fcode.bf_insns;
101 	register u_char *bp, *cp, *ep;
102 	register struct nit_bufhdr *hdrp;
103 	register struct nit_iftime *ntp;
104 	register struct nit_iflen *nlp;
105 	register struct nit_ifdrops *ndp;
106 	register int caplen;
107 
108 	cc = p->cc;
109 	if (cc == 0) {
110 		cc = read(p->fd, (char *)p->buffer, p->bufsize);
111 		if (cc < 0) {
112 			if (errno == EWOULDBLOCK)
113 				return (0);
114 			sprintf(p->errbuf, "pcap_read: %s",
115 				pcap_strerror(errno));
116 			return (-1);
117 		}
118 		bp = p->buffer;
119 	} else
120 		bp = p->bp;
121 
122 	/*
123 	 * loop through each snapshot in the chunk
124 	 */
125 	n = 0;
126 	ep = bp + cc;
127 	while (bp < ep) {
128 		++p->md.stat.ps_recv;
129 		cp = bp;
130 
131 		/* get past NIT buffer  */
132 		hdrp = (struct nit_bufhdr *)cp;
133 		cp += sizeof(*hdrp);
134 
135 		/* get past NIT timer   */
136 		ntp = (struct nit_iftime *)cp;
137 		cp += sizeof(*ntp);
138 
139 		ndp = (struct nit_ifdrops *)cp;
140 		p->md.stat.ps_drop = ndp->nh_drops;
141 		cp += sizeof *ndp;
142 
143 		/* get past packet len  */
144 		nlp = (struct nit_iflen *)cp;
145 		cp += sizeof(*nlp);
146 
147 		/* next snapshot        */
148 		bp += hdrp->nhb_totlen;
149 
150 		caplen = nlp->nh_pktlen;
151 		if (caplen > p->snapshot)
152 			caplen = p->snapshot;
153 
154 		if (bpf_filter(fcode, cp, nlp->nh_pktlen, caplen)) {
155 			struct pcap_pkthdr h;
156 			h.ts = ntp->nh_timestamp;
157 			h.len = nlp->nh_pktlen;
158 			h.caplen = caplen;
159 			(*callback)(user, &h, cp);
160 			if (++n >= cnt && cnt >= 0) {
161 				p->cc = ep - bp;
162 				p->bp = bp;
163 				return (n);
164 			}
165 		}
166 	}
167 	p->cc = 0;
168 	return (n);
169 }
170 
171 static int
172 nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
173 {
174 	bpf_u_int32 flags;
175 	struct strioctl si;
176 	struct timeval timeout;
177 
178 	si.ic_timout = INFTIM;
179 	if (to_ms != 0) {
180 		timeout.tv_sec = to_ms / 1000;
181 		timeout.tv_usec = (to_ms * 1000) % 1000000;
182 		si.ic_cmd = NIOCSTIME;
183 		si.ic_len = sizeof(timeout);
184 		si.ic_dp = (char *)&timeout;
185 		if (ioctl(fd, I_STR, (char *)&si) < 0) {
186 			sprintf(ebuf, "NIOCSTIME: %s", 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 		sprintf(ebuf, "NIOCSFLAGS: %s", pcap_strerror(errno));
198 		return (-1);
199 	}
200 	return (0);
201 }
202 
203 pcap_t *
204 pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
205 {
206 	struct strioctl si;		/* struct for ioctl() */
207 	struct ifreq ifr;		/* interface request struct */
208 	int chunksize = CHUNKSIZE;
209 	int fd;
210 	static char dev[] = "/dev/nit";
211 	register pcap_t *p;
212 
213 	p = (pcap_t *)malloc(sizeof(*p));
214 	if (p == NULL) {
215 		strcpy(ebuf, pcap_strerror(errno));
216 		return (NULL);
217 	}
218 
219 	if (snaplen < 96)
220 		/*
221 		 * NIT requires a snapshot length of at least 96.
222 		 */
223 		snaplen = 96;
224 
225 	bzero(p, sizeof(*p));
226 	p->fd = fd = open(dev, O_RDONLY);
227 	if (fd < 0) {
228 		sprintf(ebuf, "%s: %s", dev, pcap_strerror(errno));
229 		goto bad;
230 	}
231 
232 	/* arrange to get discrete messages from the STREAM and use NIT_BUF */
233 	if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
234 		sprintf(ebuf, "I_SRDOPT: %s", pcap_strerror(errno));
235 		goto bad;
236 	}
237 	if (ioctl(fd, I_PUSH, "nbuf") < 0) {
238 		sprintf(ebuf, "push nbuf: %s", pcap_strerror(errno));
239 		goto bad;
240 	}
241 	/* set the chunksize */
242 	si.ic_cmd = NIOCSCHUNK;
243 	si.ic_timout = INFTIM;
244 	si.ic_len = sizeof(chunksize);
245 	si.ic_dp = (char *)&chunksize;
246 	if (ioctl(fd, I_STR, (char *)&si) < 0) {
247 		sprintf(ebuf, "NIOCSCHUNK: %s", pcap_strerror(errno));
248 		goto bad;
249 	}
250 
251 	/* request the interface */
252 	strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
253 	ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = ' ';
254 	si.ic_cmd = NIOCBIND;
255 	si.ic_len = sizeof(ifr);
256 	si.ic_dp = (char *)&ifr;
257 	if (ioctl(fd, I_STR, (char *)&si) < 0) {
258 		sprintf(ebuf, "NIOCBIND: %s: %s",
259 			ifr.ifr_name, pcap_strerror(errno));
260 		goto bad;
261 	}
262 
263 	/* set the snapshot length */
264 	si.ic_cmd = NIOCSSNAP;
265 	si.ic_len = sizeof(snaplen);
266 	si.ic_dp = (char *)&snaplen;
267 	if (ioctl(fd, I_STR, (char *)&si) < 0) {
268 		sprintf(ebuf, "NIOCSSNAP: %s", pcap_strerror(errno));
269 		goto bad;
270 	}
271 	p->snapshot = snaplen;
272 	if (nit_setflags(p->fd, promisc, to_ms, ebuf) < 0)
273 		goto bad;
274 
275 	(void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
276 	/*
277 	 * NIT supports only ethernets.
278 	 */
279 	p->linktype = DLT_EN10MB;
280 
281 	p->bufsize = BUFSPACE;
282 	p->buffer = (u_char *)malloc(p->bufsize);
283 	if (p->buffer == NULL) {
284 		strcpy(ebuf, pcap_strerror(errno));
285 		goto bad;
286 	}
287 	return (p);
288  bad:
289 	if (fd >= 0)
290 		close(fd);
291 	free(p);
292 	return (NULL);
293 }
294 
295 int
296 pcap_setfilter(pcap_t *p, struct bpf_program *fp)
297 {
298 
299 	p->fcode = *fp;
300 	return (0);
301 }
302