xref: /freebsd/contrib/libpcap/pcap-snit.c (revision ce834215a70ff69e7e222827437116eee2f9ac6f)
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
27 static 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 */
85 static int nit_setflags(int, int, int, char *);
86 
87 int
88 pcap_stats(pcap_t *p, struct pcap_stat *ps)
89 {
90 
91 	*ps = p->md.stat;
92 	return (0);
93 }
94 
95 int
96 pcap_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 
170 static int
171 nit_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 
202 pcap_t *
203 pcap_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 
294 int
295 pcap_setfilter(pcap_t *p, struct bpf_program *fp)
296 {
297 
298 	p->fcode = *fp;
299 	return (0);
300 }
301