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