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 #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/dir.h>
34 #include <sys/fcntlcom.h>
35 #include <sys/file.h>
36 #include <sys/ioctl.h>
37 #include <sys/socket.h>
38 #include <sys/stropts.h>
39
40 #include <net/if.h>
41 #include <net/nit.h>
42 #include <net/nit_if.h>
43 #include <net/nit_pf.h>
44 #include <net/nit_buf.h>
45
46 #include <netinet/in.h>
47 #include <netinet/in_systm.h>
48 #include <netinet/ip.h>
49 #include <netinet/if_ether.h>
50 #include <netinet/ip_var.h>
51 #include <netinet/udp.h>
52 #include <netinet/udp_var.h>
53 #include <netinet/tcp.h>
54 #include <netinet/tcpip.h>
55
56 #include <errno.h>
57 #include <stdio.h>
58 #include <string.h>
59 #include <unistd.h>
60
61 #include "pcap-int.h"
62
63 #ifdef HAVE_OS_PROTO_H
64 #include "os-proto.h"
65 #endif
66
67 /*
68 * The chunk size for NIT. This is the amount of buffering
69 * done for read calls.
70 */
71 #define CHUNKSIZE (2*1024)
72
73 /*
74 * The total buffer space used by NIT.
75 */
76 #define BUFSPACE (4*CHUNKSIZE)
77
78 /* Forwards */
79 static int nit_setflags(int, int, int, char *);
80
81 /*
82 * Private data for capturing on STREAMS NIT devices.
83 */
84 struct pcap_snit {
85 struct pcap_stat stat;
86 };
87
88 static int
pcap_stats_snit(pcap_t * p,struct pcap_stat * ps)89 pcap_stats_snit(pcap_t *p, struct pcap_stat *ps)
90 {
91 struct pcap_snit *psn = p->priv;
92
93 /*
94 * "ps_recv" counts packets handed to the filter, not packets
95 * that passed the filter. As filtering is done in userland,
96 * this does not include packets dropped because we ran out
97 * of buffer space.
98 *
99 * "ps_drop" counts packets dropped inside the "/dev/nit"
100 * device because of flow control requirements or resource
101 * exhaustion; it doesn't count packets dropped by the
102 * interface driver, or packets dropped upstream. As filtering
103 * is done in userland, it counts packets regardless of whether
104 * they would've passed the filter.
105 *
106 * These statistics don't include packets not yet read from the
107 * kernel by libpcap or packets not yet read from libpcap by the
108 * application.
109 */
110 *ps = psn->stat;
111 return (0);
112 }
113
114 static int
pcap_read_snit(pcap_t * p,int cnt,pcap_handler callback,u_char * user)115 pcap_read_snit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
116 {
117 struct pcap_snit *psn = p->priv;
118 register int cc, n;
119 register u_char *bp, *cp, *ep;
120 register struct nit_bufhdr *hdrp;
121 register struct nit_iftime *ntp;
122 register struct nit_iflen *nlp;
123 register struct nit_ifdrops *ndp;
124 register int caplen;
125
126 cc = p->cc;
127 if (cc == 0) {
128 cc = read(p->fd, (char *)p->buffer, p->bufsize);
129 if (cc < 0) {
130 if (errno == EWOULDBLOCK)
131 return (0);
132 pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
133 errno, "pcap_read");
134 return (-1);
135 }
136 bp = (u_char *)p->buffer;
137 } else
138 bp = p->bp;
139
140 /*
141 * loop through each snapshot in the chunk
142 *
143 * This assumes that a single buffer of packets will have
144 * <= INT_MAX packets, so the packet count doesn't overflow.
145 */
146 n = 0;
147 ep = bp + cc;
148 while (bp < ep) {
149 /*
150 * Has "pcap_breakloop()" been called?
151 * If so, return immediately - if we haven't read any
152 * packets, clear the flag and return -2 to indicate
153 * that we were told to break out of the loop, otherwise
154 * leave the flag set, so that the *next* call will break
155 * out of the loop without having read any packets, and
156 * return the number of packets we've processed so far.
157 */
158 if (p->break_loop) {
159 if (n == 0) {
160 p->break_loop = 0;
161 return (-2);
162 } else {
163 p->bp = bp;
164 p->cc = ep - bp;
165 return (n);
166 }
167 }
168
169 ++psn->stat.ps_recv;
170 cp = bp;
171
172 /* get past NIT buffer */
173 hdrp = (struct nit_bufhdr *)cp;
174 cp += sizeof(*hdrp);
175
176 /* get past NIT timer */
177 ntp = (struct nit_iftime *)cp;
178 cp += sizeof(*ntp);
179
180 ndp = (struct nit_ifdrops *)cp;
181 psn->stat.ps_drop = ndp->nh_drops;
182 cp += sizeof *ndp;
183
184 /* get past packet len */
185 nlp = (struct nit_iflen *)cp;
186 cp += sizeof(*nlp);
187
188 /* next snapshot */
189 bp += hdrp->nhb_totlen;
190
191 caplen = nlp->nh_pktlen;
192 if (caplen > p->snapshot)
193 caplen = p->snapshot;
194
195 if (pcap_filter(p->fcode.bf_insns, cp, nlp->nh_pktlen, caplen)) {
196 struct pcap_pkthdr h;
197 h.ts = ntp->nh_timestamp;
198 h.len = nlp->nh_pktlen;
199 h.caplen = caplen;
200 (*callback)(user, &h, cp);
201 if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) {
202 p->cc = ep - bp;
203 p->bp = bp;
204 return (n);
205 }
206 }
207 }
208 p->cc = 0;
209 return (n);
210 }
211
212 static int
pcap_inject_snit(pcap_t * p,const void * buf,int size)213 pcap_inject_snit(pcap_t *p, const void *buf, int size)
214 {
215 struct strbuf ctl, data;
216
217 /*
218 * XXX - can we just do
219 *
220 ret = write(pd->f, buf, size);
221 */
222 ctl.len = sizeof(*sa); /* XXX - what was this? */
223 ctl.buf = (char *)sa;
224 data.buf = buf;
225 data.len = size;
226 ret = putmsg(p->fd, &ctl, &data);
227 if (ret == -1) {
228 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
229 errno, "send");
230 return (-1);
231 }
232 return (ret);
233 }
234
235 static int
nit_setflags(pcap_t * p)236 nit_setflags(pcap_t *p)
237 {
238 bpf_u_int32 flags;
239 struct strioctl si;
240 u_int zero = 0;
241 struct timeval timeout;
242
243 if (p->opt.immediate) {
244 /*
245 * Set the chunk size to zero, so that chunks get sent
246 * up immediately.
247 */
248 si.ic_cmd = NIOCSCHUNK;
249 si.ic_len = sizeof(zero);
250 si.ic_dp = (char *)&zero;
251 if (ioctl(p->fd, I_STR, (char *)&si) < 0) {
252 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
253 errno, "NIOCSCHUNK");
254 return (-1);
255 }
256 }
257 si.ic_timout = INFTIM;
258 if (p->opt.timeout != 0) {
259 timeout.tv_sec = p->opt.timeout / 1000;
260 timeout.tv_usec = (p->opt.timeout * 1000) % 1000000;
261 si.ic_cmd = NIOCSTIME;
262 si.ic_len = sizeof(timeout);
263 si.ic_dp = (char *)&timeout;
264 if (ioctl(p->fd, I_STR, (char *)&si) < 0) {
265 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
266 errno, "NIOCSTIME");
267 return (-1);
268 }
269 }
270 flags = NI_TIMESTAMP | NI_LEN | NI_DROPS;
271 if (p->opt.promisc)
272 flags |= NI_PROMISC;
273 si.ic_cmd = NIOCSFLAGS;
274 si.ic_len = sizeof(flags);
275 si.ic_dp = (char *)&flags;
276 if (ioctl(p->fd, I_STR, (char *)&si) < 0) {
277 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
278 errno, "NIOCSFLAGS");
279 return (-1);
280 }
281 return (0);
282 }
283
284 static int
pcap_activate_snit(pcap_t * p)285 pcap_activate_snit(pcap_t *p)
286 {
287 struct strioctl si; /* struct for ioctl() */
288 struct ifreq ifr; /* interface request struct */
289 int chunksize = CHUNKSIZE;
290 int fd;
291 static const char dev[] = "/dev/nit";
292 int err;
293
294 if (p->opt.rfmon) {
295 /*
296 * No monitor mode on SunOS 4.x (no Wi-Fi devices on
297 * hardware supported by SunOS 4.x).
298 */
299 return (PCAP_ERROR_RFMON_NOTSUP);
300 }
301
302 /*
303 * Turn a negative snapshot value (invalid), a snapshot value of
304 * 0 (unspecified), or a value bigger than the normal maximum
305 * value, into the maximum allowed value.
306 *
307 * If some application really *needs* a bigger snapshot
308 * length, we should just increase MAXIMUM_SNAPLEN.
309 */
310 if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
311 p->snapshot = MAXIMUM_SNAPLEN;
312
313 if (p->snapshot < 96)
314 /*
315 * NIT requires a snapshot length of at least 96.
316 */
317 p->snapshot = 96;
318
319 /*
320 * Initially try a read/write open (to allow the inject
321 * method to work). If that fails due to permission
322 * issues, fall back to read-only. This allows a
323 * non-root user to be granted specific access to pcap
324 * capabilities via file permissions.
325 *
326 * XXX - we should have an API that has a flag that
327 * controls whether to open read-only or read-write,
328 * so that denial of permission to send (or inability
329 * to send, if sending packets isn't supported on
330 * the device in question) can be indicated at open
331 * time.
332 */
333 p->fd = fd = open(dev, O_RDWR);
334 if (fd < 0 && errno == EACCES)
335 p->fd = fd = open(dev, O_RDONLY);
336 if (fd < 0) {
337 if (errno == EACCES) {
338 err = PCAP_ERROR_PERM_DENIED;
339 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
340 "Attempt to open %s failed with EACCES - root privileges may be required",
341 dev);
342 } else {
343 err = PCAP_ERROR;
344 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
345 errno, "%s", dev);
346 }
347 goto bad;
348 }
349
350 /* arrange to get discrete messages from the STREAM and use NIT_BUF */
351 if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
352 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
353 errno, "I_SRDOPT");
354 err = PCAP_ERROR;
355 goto bad;
356 }
357 if (ioctl(fd, I_PUSH, "nbuf") < 0) {
358 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
359 errno, "push nbuf");
360 err = PCAP_ERROR;
361 goto bad;
362 }
363 /* set the chunksize */
364 si.ic_cmd = NIOCSCHUNK;
365 si.ic_timout = INFTIM;
366 si.ic_len = sizeof(chunksize);
367 si.ic_dp = (char *)&chunksize;
368 if (ioctl(fd, I_STR, (char *)&si) < 0) {
369 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
370 errno, "NIOCSCHUNK");
371 err = PCAP_ERROR;
372 goto bad;
373 }
374
375 /* request the interface */
376 strncpy(ifr.ifr_name, p->opt.device, sizeof(ifr.ifr_name));
377 ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
378 si.ic_cmd = NIOCBIND;
379 si.ic_len = sizeof(ifr);
380 si.ic_dp = (char *)𝔦
381 if (ioctl(fd, I_STR, (char *)&si) < 0) {
382 /*
383 * XXX - is there an error that means "no such device"?
384 * Is there one that means "that device doesn't support
385 * STREAMS NIT"?
386 */
387 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
388 errno, "NIOCBIND: %s", ifr.ifr_name);
389 err = PCAP_ERROR;
390 goto bad;
391 }
392
393 /* set the snapshot length */
394 si.ic_cmd = NIOCSSNAP;
395 si.ic_len = sizeof(p->snapshot);
396 si.ic_dp = (char *)&p->snapshot;
397 if (ioctl(fd, I_STR, (char *)&si) < 0) {
398 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
399 errno, "NIOCSSNAP");
400 err = PCAP_ERROR;
401 goto bad;
402 }
403 if (nit_setflags(p) < 0) {
404 err = PCAP_ERROR;
405 goto bad;
406 }
407
408 (void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
409 /*
410 * NIT supports only ethernets.
411 */
412 p->linktype = DLT_EN10MB;
413
414 p->bufsize = BUFSPACE;
415 p->buffer = malloc(p->bufsize);
416 if (p->buffer == NULL) {
417 pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
418 errno, "malloc");
419 err = PCAP_ERROR;
420 goto bad;
421 }
422
423 /*
424 * "p->fd" is an FD for a STREAMS device, so "select()" and
425 * "poll()" should work on it.
426 */
427 p->selectable_fd = p->fd;
428
429 /*
430 * This is (presumably) a real Ethernet capture; give it a
431 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
432 * that an application can let you choose it, in case you're
433 * capturing DOCSIS traffic that a Cisco Cable Modem
434 * Termination System is putting out onto an Ethernet (it
435 * doesn't put an Ethernet header onto the wire, it puts raw
436 * DOCSIS frames out on the wire inside the low-level
437 * Ethernet framing).
438 */
439 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
440 /*
441 * If that fails, just leave the list empty.
442 */
443 if (p->dlt_list != NULL) {
444 p->dlt_list[0] = DLT_EN10MB;
445 p->dlt_list[1] = DLT_DOCSIS;
446 p->dlt_count = 2;
447 }
448
449 p->read_op = pcap_read_snit;
450 p->inject_op = pcap_inject_snit;
451 p->setfilter_op = install_bpf_program; /* no kernel filtering */
452 p->setdirection_op = NULL; /* Not implemented. */
453 p->set_datalink_op = NULL; /* can't change data link type */
454 p->getnonblock_op = pcap_getnonblock_fd;
455 p->setnonblock_op = pcap_setnonblock_fd;
456 p->stats_op = pcap_stats_snit;
457
458 return (0);
459 bad:
460 pcap_cleanup_live_common(p);
461 return (err);
462 }
463
464 pcap_t *
pcap_create_interface(const char * device _U_,char * ebuf)465 pcap_create_interface(const char *device _U_, char *ebuf)
466 {
467 pcap_t *p;
468
469 p = PCAP_CREATE_COMMON(ebuf, struct pcap_snit);
470 if (p == NULL)
471 return (NULL);
472
473 p->activate_op = pcap_activate_snit;
474 return (p);
475 }
476
477 /*
478 * XXX - there's probably a NIOCBIND error that means "that device
479 * doesn't support NIT"; if so, we should try an NIOCBIND and use that.
480 */
481 static int
can_be_bound(const char * name _U_)482 can_be_bound(const char *name _U_)
483 {
484 return (1);
485 }
486
487 static int
get_if_flags(const char * name _U_,bpf_u_int32 * flags _U_,char * errbuf _U_)488 get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)
489 {
490 /*
491 * Nothing we can do.
492 * XXX - is there a way to find out whether an adapter has
493 * something plugged into it?
494 */
495 return (0);
496 }
497
498 int
pcap_platform_finddevs(pcap_if_list_t * devlistp,char * errbuf)499 pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
500 {
501 return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound,
502 get_if_flags));
503 }
504
505 /*
506 * Libpcap version string.
507 */
508 const char *
pcap_lib_version(void)509 pcap_lib_version(void)
510 {
511 return (PCAP_VERSION_STRING);
512 }
513