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 const char rcsid[] _U_ =
23 "@(#) $Header: /tcpdump/master/libpcap/pcap-nit.c,v 1.62 2008-04-14 20:40:58 guy Exp $ (LBL)";
24 #endif
25
26 #ifdef HAVE_CONFIG_H
27 #include "config.h"
28 #endif
29
30 #include <sys/types.h>
31 #include <sys/time.h>
32 #include <sys/timeb.h>
33 #include <sys/file.h>
34 #include <sys/ioctl.h>
35 #include <sys/socket.h>
36
37 #include <net/if.h>
38 #include <net/nit.h>
39
40 #include <netinet/in.h>
41 #include <netinet/in_systm.h>
42 #include <netinet/ip.h>
43 #include <netinet/if_ether.h>
44 #include <netinet/ip_var.h>
45 #include <netinet/udp.h>
46 #include <netinet/udp_var.h>
47 #include <netinet/tcp.h>
48 #include <netinet/tcpip.h>
49
50 #include <ctype.h>
51 #include <errno.h>
52 #include <stdio.h>
53
54 #include "pcap-int.h"
55
56 #ifdef HAVE_OS_PROTO_H
57 #include "os-proto.h"
58 #endif
59
60 /*
61 * The chunk size for NIT. This is the amount of buffering
62 * done for read calls.
63 */
64 #define CHUNKSIZE (2*1024)
65
66 /*
67 * The total buffer space used by NIT.
68 */
69 #define BUFSPACE (4*CHUNKSIZE)
70
71 /* Forwards */
72 static int nit_setflags(int, int, int, char *);
73
74 /*
75 * Private data for capturing on NIT devices.
76 */
77 struct pcap_nit {
78 struct pcap_stat stat;
79 };
80
81 static int
pcap_stats_nit(pcap_t * p,struct pcap_stat * ps)82 pcap_stats_nit(pcap_t *p, struct pcap_stat *ps)
83 {
84 struct pcap_nit *pn = p->priv;
85
86 /*
87 * "ps_recv" counts packets handed to the filter, not packets
88 * that passed the filter. As filtering is done in userland,
89 * this does not include packets dropped because we ran out
90 * of buffer space.
91 *
92 * "ps_drop" presumably counts packets dropped by the socket
93 * because of flow control requirements or resource exhaustion;
94 * it doesn't count packets dropped by the interface driver.
95 * As filtering is done in userland, it counts packets regardless
96 * of whether they would've passed the filter.
97 *
98 * These statistics don't include packets not yet read from the
99 * kernel by libpcap or packets not yet read from libpcap by the
100 * application.
101 */
102 *ps = pn->stat;
103 return (0);
104 }
105
106 static int
pcap_read_nit(pcap_t * p,int cnt,pcap_handler callback,u_char * user)107 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
108 {
109 struct pcap_nit *pn = p->priv;
110 register int cc, n;
111 register u_char *bp, *cp, *ep;
112 register struct nit_hdr *nh;
113 register int caplen;
114
115 cc = p->cc;
116 if (cc == 0) {
117 cc = read(p->fd, (char *)p->buffer, p->bufsize);
118 if (cc < 0) {
119 if (errno == EWOULDBLOCK)
120 return (0);
121 snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
122 pcap_strerror(errno));
123 return (-1);
124 }
125 bp = p->buffer;
126 } else
127 bp = p->bp;
128
129 /*
130 * Loop through each packet. The increment expression
131 * rounds up to the next int boundary past the end of
132 * the previous packet.
133 */
134 n = 0;
135 ep = bp + cc;
136 while (bp < ep) {
137 /*
138 * Has "pcap_breakloop()" been called?
139 * If so, return immediately - if we haven't read any
140 * packets, clear the flag and return -2 to indicate
141 * that we were told to break out of the loop, otherwise
142 * leave the flag set, so that the *next* call will break
143 * out of the loop without having read any packets, and
144 * return the number of packets we've processed so far.
145 */
146 if (p->break_loop) {
147 if (n == 0) {
148 p->break_loop = 0;
149 return (-2);
150 } else {
151 p->cc = ep - bp;
152 p->bp = bp;
153 return (n);
154 }
155 }
156
157 nh = (struct nit_hdr *)bp;
158 cp = bp + sizeof(*nh);
159
160 switch (nh->nh_state) {
161
162 case NIT_CATCH:
163 break;
164
165 case NIT_NOMBUF:
166 case NIT_NOCLUSTER:
167 case NIT_NOSPACE:
168 pn->stat.ps_drop = nh->nh_dropped;
169 continue;
170
171 case NIT_SEQNO:
172 continue;
173
174 default:
175 snprintf(p->errbuf, sizeof(p->errbuf),
176 "bad nit state %d", nh->nh_state);
177 return (-1);
178 }
179 ++pn->stat.ps_recv;
180 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
181 sizeof(int) - 1) & ~(sizeof(int) - 1));
182
183 caplen = nh->nh_wirelen;
184 if (caplen > p->snapshot)
185 caplen = p->snapshot;
186 if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) {
187 struct pcap_pkthdr h;
188 h.ts = nh->nh_timestamp;
189 h.len = nh->nh_wirelen;
190 h.caplen = caplen;
191 (*callback)(user, &h, cp);
192 if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) {
193 p->cc = ep - bp;
194 p->bp = bp;
195 return (n);
196 }
197 }
198 }
199 p->cc = 0;
200 return (n);
201 }
202
203 static int
pcap_inject_nit(pcap_t * p,const void * buf,size_t size)204 pcap_inject_nit(pcap_t *p, const void *buf, size_t size)
205 {
206 struct sockaddr sa;
207 int ret;
208
209 memset(&sa, 0, sizeof(sa));
210 strncpy(sa.sa_data, device, sizeof(sa.sa_data));
211 ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa));
212 if (ret == -1) {
213 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
214 pcap_strerror(errno));
215 return (-1);
216 }
217 return (ret);
218 }
219
220 static int
nit_setflags(pcap_t * p)221 nit_setflags(pcap_t *p)
222 {
223 struct nit_ioc nioc;
224
225 memset(&nioc, 0, sizeof(nioc));
226 nioc.nioc_typetomatch = NT_ALLTYPES;
227 nioc.nioc_snaplen = p->snapshot;
228 nioc.nioc_bufalign = sizeof(int);
229 nioc.nioc_bufoffset = 0;
230
231 if (p->opt.buffer_size != 0)
232 nioc.nioc_bufspace = p->opt.buffer_size;
233 else {
234 /* Default buffer size */
235 nioc.nioc_bufspace = BUFSPACE;
236 }
237
238 if (p->opt.immediate) {
239 /*
240 * XXX - will this cause packets to be delivered immediately?
241 * XXX - given that this is for SunOS prior to 4.0, do
242 * we care?
243 */
244 nioc.nioc_chunksize = 0;
245 } else
246 nioc.nioc_chunksize = CHUNKSIZE;
247 if (p->opt.timeout != 0) {
248 nioc.nioc_flags |= NF_TIMEOUT;
249 nioc.nioc_timeout.tv_sec = p->opt.timeout / 1000;
250 nioc.nioc_timeout.tv_usec = (p->opt.timeout * 1000) % 1000000;
251 }
252 if (p->opt.promisc)
253 nioc.nioc_flags |= NF_PROMISC;
254
255 if (ioctl(p->fd, SIOCSNIT, &nioc) < 0) {
256 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s",
257 pcap_strerror(errno));
258 return (-1);
259 }
260 return (0);
261 }
262
263 static int
pcap_activate_nit(pcap_t * p)264 pcap_activate_nit(pcap_t *p)
265 {
266 int fd;
267 struct sockaddr_nit snit;
268
269 if (p->opt.rfmon) {
270 /*
271 * No monitor mode on SunOS 3.x or earlier (no
272 * Wi-Fi *devices* for the hardware that supported
273 * them!).
274 */
275 return (PCAP_ERROR_RFMON_NOTSUP);
276 }
277
278 if (p->snapshot < 96)
279 /*
280 * NIT requires a snapshot length of at least 96.
281 */
282 p->snapshot = 96;
283
284 memset(p, 0, sizeof(*p));
285 p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
286 if (fd < 0) {
287 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
288 "socket: %s", pcap_strerror(errno));
289 goto bad;
290 }
291 snit.snit_family = AF_NIT;
292 (void)strncpy(snit.snit_ifname, p->opt.source, NITIFSIZ);
293
294 if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
295 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
296 "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno));
297 goto bad;
298 }
299 if (nit_setflags(p) < 0)
300 goto bad;
301
302 /*
303 * NIT supports only ethernets.
304 */
305 p->linktype = DLT_EN10MB;
306
307 p->bufsize = BUFSPACE;
308 p->buffer = (u_char *)malloc(p->bufsize);
309 if (p->buffer == NULL) {
310 strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
311 goto bad;
312 }
313
314 /*
315 * "p->fd" is a socket, so "select()" should work on it.
316 */
317 p->selectable_fd = p->fd;
318
319 /*
320 * This is (presumably) a real Ethernet capture; give it a
321 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
322 * that an application can let you choose it, in case you're
323 * capturing DOCSIS traffic that a Cisco Cable Modem
324 * Termination System is putting out onto an Ethernet (it
325 * doesn't put an Ethernet header onto the wire, it puts raw
326 * DOCSIS frames out on the wire inside the low-level
327 * Ethernet framing).
328 */
329 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
330 /*
331 * If that fails, just leave the list empty.
332 */
333 if (p->dlt_list != NULL) {
334 p->dlt_list[0] = DLT_EN10MB;
335 p->dlt_list[1] = DLT_DOCSIS;
336 p->dlt_count = 2;
337 }
338
339 p->read_op = pcap_read_nit;
340 p->inject_op = pcap_inject_nit;
341 p->setfilter_op = install_bpf_program; /* no kernel filtering */
342 p->setdirection_op = NULL; /* Not implemented. */
343 p->set_datalink_op = NULL; /* can't change data link type */
344 p->getnonblock_op = pcap_getnonblock_fd;
345 p->setnonblock_op = pcap_setnonblock_fd;
346 p->stats_op = pcap_stats_nit;
347
348 return (0);
349 bad:
350 pcap_cleanup_live_common(p);
351 return (PCAP_ERROR);
352 }
353
354 pcap_t *
pcap_create_interface(const char * device,char * ebuf)355 pcap_create_interface(const char *device, char *ebuf)
356 {
357 pcap_t *p;
358
359 p = pcap_create_common(device, ebuf, sizeof (struct pcap_nit));
360 if (p == NULL)
361 return (NULL);
362
363 p->activate_op = pcap_activate_nit;
364 return (p);
365 }
366
367 int
pcap_platform_finddevs(pcap_if_t ** alldevsp,char * errbuf)368 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
369 {
370 return (0);
371 }
372