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
22 #ifdef HAVE_CONFIG_H
23 #include <config.h>
24 #endif
25
26 #include <sys/types.h>
27 #include <sys/time.h>
28 #include <sys/timeb.h>
29 #include <sys/file.h>
30 #include <sys/ioctl.h>
31 #include <sys/socket.h>
32
33 #include <net/if.h>
34 #include <net/nit.h>
35
36 #include <netinet/in.h>
37 #include <netinet/in_systm.h>
38 #include <netinet/ip.h>
39 #include <netinet/if_ether.h>
40 #include <netinet/ip_var.h>
41 #include <netinet/udp.h>
42 #include <netinet/udp_var.h>
43 #include <netinet/tcp.h>
44 #include <netinet/tcpip.h>
45
46 #include <ctype.h>
47 #include <errno.h>
48 #include <stdio.h>
49
50 #include "pcap-int.h"
51
52 #ifdef HAVE_OS_PROTO_H
53 #include "os-proto.h"
54 #endif
55
56 /*
57 * The chunk size for NIT. This is the amount of buffering
58 * done for read calls.
59 */
60 #define CHUNKSIZE (2*1024)
61
62 /*
63 * The total buffer space used by NIT.
64 */
65 #define BUFSPACE (4*CHUNKSIZE)
66
67 /* Forwards */
68 static int nit_setflags(int, int, int, char *);
69
70 /*
71 * Private data for capturing on NIT devices.
72 */
73 struct pcap_nit {
74 struct pcap_stat stat;
75 };
76
77 static int
pcap_stats_nit(pcap_t * p,struct pcap_stat * ps)78 pcap_stats_nit(pcap_t *p, struct pcap_stat *ps)
79 {
80 struct pcap_nit *pn = p->priv;
81
82 /*
83 * "ps_recv" counts packets handed to the filter, not packets
84 * that passed the filter. As filtering is done in userland,
85 * this does not include packets dropped because we ran out
86 * of buffer space.
87 *
88 * "ps_drop" presumably counts packets dropped by the socket
89 * because of flow control requirements or resource exhaustion;
90 * it doesn't count packets dropped by the interface driver.
91 * As filtering is done in userland, it counts packets regardless
92 * of whether they would've passed the filter.
93 *
94 * These statistics don't include packets not yet read from the
95 * kernel by libpcap or packets not yet read from libpcap by the
96 * application.
97 */
98 *ps = pn->stat;
99 return (0);
100 }
101
102 static int
pcap_read_nit(pcap_t * p,int cnt,pcap_handler callback,u_char * user)103 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
104 {
105 struct pcap_nit *pn = p->priv;
106 register int cc, n;
107 register u_char *bp, *cp, *ep;
108 register struct nit_hdr *nh;
109 register int caplen;
110
111 cc = p->cc;
112 if (cc == 0) {
113 cc = read(p->fd, (char *)p->buffer, p->bufsize);
114 if (cc < 0) {
115 if (errno == EWOULDBLOCK)
116 return (0);
117 pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
118 errno, "pcap_read");
119 return (-1);
120 }
121 bp = (u_char *)p->buffer;
122 } else
123 bp = p->bp;
124
125 /*
126 * Loop through each packet. The increment expression
127 * rounds up to the next int boundary past the end of
128 * the previous packet.
129 */
130 n = 0;
131 ep = bp + cc;
132 while (bp < ep) {
133 /*
134 * Has "pcap_breakloop()" been called?
135 * If so, return immediately - if we haven't read any
136 * packets, clear the flag and return -2 to indicate
137 * that we were told to break out of the loop, otherwise
138 * leave the flag set, so that the *next* call will break
139 * out of the loop without having read any packets, and
140 * return the number of packets we've processed so far.
141 */
142 if (p->break_loop) {
143 if (n == 0) {
144 p->break_loop = 0;
145 return (-2);
146 } else {
147 p->cc = ep - bp;
148 p->bp = bp;
149 return (n);
150 }
151 }
152
153 nh = (struct nit_hdr *)bp;
154 cp = bp + sizeof(*nh);
155
156 switch (nh->nh_state) {
157
158 case NIT_CATCH:
159 break;
160
161 case NIT_NOMBUF:
162 case NIT_NOCLUSTER:
163 case NIT_NOSPACE:
164 pn->stat.ps_drop = nh->nh_dropped;
165 continue;
166
167 case NIT_SEQNO:
168 continue;
169
170 default:
171 pcap_snprintf(p->errbuf, sizeof(p->errbuf),
172 "bad nit state %d", nh->nh_state);
173 return (-1);
174 }
175 ++pn->stat.ps_recv;
176 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
177 sizeof(int) - 1) & ~(sizeof(int) - 1));
178
179 caplen = nh->nh_wirelen;
180 if (caplen > p->snapshot)
181 caplen = p->snapshot;
182 if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) {
183 struct pcap_pkthdr h;
184 h.ts = nh->nh_timestamp;
185 h.len = nh->nh_wirelen;
186 h.caplen = caplen;
187 (*callback)(user, &h, cp);
188 if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) {
189 p->cc = ep - bp;
190 p->bp = bp;
191 return (n);
192 }
193 }
194 }
195 p->cc = 0;
196 return (n);
197 }
198
199 static int
pcap_inject_nit(pcap_t * p,const void * buf,size_t size)200 pcap_inject_nit(pcap_t *p, const void *buf, size_t size)
201 {
202 struct sockaddr sa;
203 int ret;
204
205 memset(&sa, 0, sizeof(sa));
206 strncpy(sa.sa_data, device, sizeof(sa.sa_data));
207 ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa));
208 if (ret == -1) {
209 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
210 errno, "send");
211 return (-1);
212 }
213 return (ret);
214 }
215
216 static int
nit_setflags(pcap_t * p)217 nit_setflags(pcap_t *p)
218 {
219 struct nit_ioc nioc;
220
221 memset(&nioc, 0, sizeof(nioc));
222 nioc.nioc_typetomatch = NT_ALLTYPES;
223 nioc.nioc_snaplen = p->snapshot;
224 nioc.nioc_bufalign = sizeof(int);
225 nioc.nioc_bufoffset = 0;
226
227 if (p->opt.buffer_size != 0)
228 nioc.nioc_bufspace = p->opt.buffer_size;
229 else {
230 /* Default buffer size */
231 nioc.nioc_bufspace = BUFSPACE;
232 }
233
234 if (p->opt.immediate) {
235 /*
236 * XXX - will this cause packets to be delivered immediately?
237 * XXX - given that this is for SunOS prior to 4.0, do
238 * we care?
239 */
240 nioc.nioc_chunksize = 0;
241 } else
242 nioc.nioc_chunksize = CHUNKSIZE;
243 if (p->opt.timeout != 0) {
244 nioc.nioc_flags |= NF_TIMEOUT;
245 nioc.nioc_timeout.tv_sec = p->opt.timeout / 1000;
246 nioc.nioc_timeout.tv_usec = (p->opt.timeout * 1000) % 1000000;
247 }
248 if (p->opt.promisc)
249 nioc.nioc_flags |= NF_PROMISC;
250
251 if (ioctl(p->fd, SIOCSNIT, &nioc) < 0) {
252 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
253 errno, "SIOCSNIT");
254 return (-1);
255 }
256 return (0);
257 }
258
259 static int
pcap_activate_nit(pcap_t * p)260 pcap_activate_nit(pcap_t *p)
261 {
262 int fd;
263 struct sockaddr_nit snit;
264
265 if (p->opt.rfmon) {
266 /*
267 * No monitor mode on SunOS 3.x or earlier (no
268 * Wi-Fi *devices* for the hardware that supported
269 * them!).
270 */
271 return (PCAP_ERROR_RFMON_NOTSUP);
272 }
273
274 /*
275 * Turn a negative snapshot value (invalid), a snapshot value of
276 * 0 (unspecified), or a value bigger than the normal maximum
277 * value, into the maximum allowed value.
278 *
279 * If some application really *needs* a bigger snapshot
280 * length, we should just increase MAXIMUM_SNAPLEN.
281 */
282 if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
283 p->snapshot = MAXIMUM_SNAPLEN;
284
285 if (p->snapshot < 96)
286 /*
287 * NIT requires a snapshot length of at least 96.
288 */
289 p->snapshot = 96;
290
291 memset(p, 0, sizeof(*p));
292 p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
293 if (fd < 0) {
294 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
295 errno, "socket");
296 goto bad;
297 }
298 snit.snit_family = AF_NIT;
299 (void)strncpy(snit.snit_ifname, p->opt.device, NITIFSIZ);
300
301 if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
302 /*
303 * XXX - there's probably a particular bind error that
304 * means "there's no such device" and a particular bind
305 * error that means "that device doesn't support NIT";
306 * they might be the same error, if they both end up
307 * meaning "NIT doesn't know about that device".
308 */
309 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
310 errno, "bind: %s", snit.snit_ifname);
311 goto bad;
312 }
313 if (nit_setflags(p) < 0)
314 goto bad;
315
316 /*
317 * NIT supports only ethernets.
318 */
319 p->linktype = DLT_EN10MB;
320
321 p->bufsize = BUFSPACE;
322 p->buffer = malloc(p->bufsize);
323 if (p->buffer == NULL) {
324 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
325 errno, "malloc");
326 goto bad;
327 }
328
329 /*
330 * "p->fd" is a socket, so "select()" should work on it.
331 */
332 p->selectable_fd = p->fd;
333
334 /*
335 * This is (presumably) a real Ethernet capture; give it a
336 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
337 * that an application can let you choose it, in case you're
338 * capturing DOCSIS traffic that a Cisco Cable Modem
339 * Termination System is putting out onto an Ethernet (it
340 * doesn't put an Ethernet header onto the wire, it puts raw
341 * DOCSIS frames out on the wire inside the low-level
342 * Ethernet framing).
343 */
344 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
345 /*
346 * If that fails, just leave the list empty.
347 */
348 if (p->dlt_list != NULL) {
349 p->dlt_list[0] = DLT_EN10MB;
350 p->dlt_list[1] = DLT_DOCSIS;
351 p->dlt_count = 2;
352 }
353
354 p->read_op = pcap_read_nit;
355 p->inject_op = pcap_inject_nit;
356 p->setfilter_op = install_bpf_program; /* no kernel filtering */
357 p->setdirection_op = NULL; /* Not implemented. */
358 p->set_datalink_op = NULL; /* can't change data link type */
359 p->getnonblock_op = pcap_getnonblock_fd;
360 p->setnonblock_op = pcap_setnonblock_fd;
361 p->stats_op = pcap_stats_nit;
362
363 return (0);
364 bad:
365 pcap_cleanup_live_common(p);
366 return (PCAP_ERROR);
367 }
368
369 pcap_t *
pcap_create_interface(const char * device _U_,char * ebuf)370 pcap_create_interface(const char *device _U_, char *ebuf)
371 {
372 pcap_t *p;
373
374 p = pcap_create_common(ebuf, sizeof (struct pcap_nit));
375 if (p == NULL)
376 return (NULL);
377
378 p->activate_op = pcap_activate_nit;
379 return (p);
380 }
381
382 /*
383 * XXX - there's probably a particular bind error that means "that device
384 * doesn't support NIT"; if so, we should try a bind and use that.
385 */
386 static int
can_be_bound(const char * name _U_)387 can_be_bound(const char *name _U_)
388 {
389 return (1);
390 }
391
392 static int
get_if_flags(const char * name _U_,bpf_u_int32 * flags _U_,char * errbuf _U_)393 get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)
394 {
395 /*
396 * Nothing we can do.
397 * XXX - is there a way to find out whether an adapter has
398 * something plugged into it?
399 */
400 return (0);
401 }
402
403 int
pcap_platform_finddevs(pcap_if_list_t * devlistp,char * errbuf)404 pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
405 {
406 return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound,
407 get_if_flags));
408 }
409
410 /*
411 * Libpcap version string.
412 */
413 const char *
pcap_lib_version(void)414 pcap_lib_version(void)
415 {
416 return (PCAP_VERSION_STRING);
417 }
418