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 #include <config.h>
27
28 #include <sys/types.h>
29 #include <sys/time.h>
30 #include <sys/timeb.h>
31 #include <sys/dir.h>
32 #include <sys/fcntlcom.h>
33 #include <sys/file.h>
34 #include <sys/ioctl.h>
35 #include <sys/socket.h>
36 #include <sys/stropts.h>
37
38 #include <net/if.h>
39 #include <net/nit.h>
40 #include <net/nit_if.h>
41 #include <net/nit_pf.h>
42 #include <net/nit_buf.h>
43
44 #include <netinet/in.h>
45 #include <netinet/in_systm.h>
46 #include <netinet/ip.h>
47 #include <netinet/if_ether.h>
48 #include <netinet/ip_var.h>
49 #include <netinet/udp.h>
50 #include <netinet/udp_var.h>
51 #include <netinet/tcp.h>
52 #include <netinet/tcpip.h>
53
54 #include <errno.h>
55 #include <stdio.h>
56 #include <string.h>
57 #include <unistd.h>
58
59 #include "pcap-int.h"
60
61 #ifdef HAVE_OS_PROTO_H
62 #include "os-proto.h"
63 #endif
64
65 /*
66 * The chunk size for NIT. This is the amount of buffering
67 * done for read calls.
68 */
69 #define CHUNKSIZE (2*1024)
70
71 /*
72 * The total buffer space used by NIT.
73 */
74 #define BUFSPACE (4*CHUNKSIZE)
75
76 /* Forwards */
77 static int nit_setflags(int, int, int, char *);
78
79 /*
80 * Private data for capturing on STREAMS NIT devices.
81 */
82 struct pcap_snit {
83 struct pcap_stat stat;
84 };
85
86 static int
pcap_stats_snit(pcap_t * p,struct pcap_stat * ps)87 pcap_stats_snit(pcap_t *p, struct pcap_stat *ps)
88 {
89 struct pcap_snit *psn = p->priv;
90
91 /*
92 * "ps_recv" counts packets handed to the filter, not packets
93 * that passed the filter. As filtering is done in userland,
94 * this does not include packets dropped because we ran out
95 * of buffer space.
96 *
97 * "ps_drop" counts packets dropped inside the "/dev/nit"
98 * device because of flow control requirements or resource
99 * exhaustion; it doesn't count packets dropped by the
100 * interface driver, or packets dropped upstream. As filtering
101 * is done in userland, it counts packets regardless of whether
102 * they would've passed the filter.
103 *
104 * These statistics don't include packets not yet read from the
105 * kernel by libpcap or packets not yet read from libpcap by the
106 * application.
107 */
108 *ps = psn->stat;
109 return (0);
110 }
111
112 static int
pcap_read_snit(pcap_t * p,int cnt,pcap_handler callback,u_char * user)113 pcap_read_snit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
114 {
115 struct pcap_snit *psn = p->priv;
116 register int cc, n;
117 register u_char *bp, *cp, *ep;
118 register struct nit_bufhdr *hdrp;
119 register struct nit_iftime *ntp;
120 register struct nit_iflen *nlp;
121 register struct nit_ifdrops *ndp;
122 register int caplen;
123
124 cc = p->cc;
125 if (cc == 0) {
126 cc = read(p->fd, (char *)p->buffer, p->bufsize);
127 if (cc < 0) {
128 if (errno == EWOULDBLOCK)
129 return (0);
130 pcapint_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
131 errno, "pcap_read");
132 return (-1);
133 }
134 bp = (u_char *)p->buffer;
135 } else
136 bp = p->bp;
137
138 /*
139 * loop through each snapshot in the chunk
140 *
141 * This assumes that a single buffer of packets will have
142 * <= INT_MAX packets, so the packet count doesn't overflow.
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 (pcapint_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,int size)211 pcap_inject_snit(pcap_t *p, const void *buf, int 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 pcapint_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 pcapint_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 pcapint_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 pcapint_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 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
338 "Attempt to open %s failed with EACCES - root privileges may be required",
339 dev);
340 } else {
341 err = PCAP_ERROR;
342 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
343 errno, "%s", dev);
344 }
345 goto bad;
346 }
347
348 /* arrange to get discrete messages from the STREAM and use NIT_BUF */
349 if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
350 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
351 errno, "I_SRDOPT");
352 err = PCAP_ERROR;
353 goto bad;
354 }
355 if (ioctl(fd, I_PUSH, "nbuf") < 0) {
356 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
357 errno, "push nbuf");
358 err = PCAP_ERROR;
359 goto bad;
360 }
361 /* set the chunksize */
362 si.ic_cmd = NIOCSCHUNK;
363 si.ic_timout = INFTIM;
364 si.ic_len = sizeof(chunksize);
365 si.ic_dp = (char *)&chunksize;
366 if (ioctl(fd, I_STR, (char *)&si) < 0) {
367 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
368 errno, "NIOCSCHUNK");
369 err = PCAP_ERROR;
370 goto bad;
371 }
372
373 /* request the interface */
374 strncpy(ifr.ifr_name, p->opt.device, sizeof(ifr.ifr_name));
375 ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
376 si.ic_cmd = NIOCBIND;
377 si.ic_len = sizeof(ifr);
378 si.ic_dp = (char *)𝔦
379 if (ioctl(fd, I_STR, (char *)&si) < 0) {
380 /*
381 * XXX - is there an error that means "no such device"?
382 * Is there one that means "that device doesn't support
383 * STREAMS NIT"?
384 */
385 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
386 errno, "NIOCBIND: %s", ifr.ifr_name);
387 err = PCAP_ERROR;
388 goto bad;
389 }
390
391 /* set the snapshot length */
392 si.ic_cmd = NIOCSSNAP;
393 si.ic_len = sizeof(p->snapshot);
394 si.ic_dp = (char *)&p->snapshot;
395 if (ioctl(fd, I_STR, (char *)&si) < 0) {
396 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
397 errno, "NIOCSSNAP");
398 err = PCAP_ERROR;
399 goto bad;
400 }
401 if (nit_setflags(p) < 0) {
402 err = PCAP_ERROR;
403 goto bad;
404 }
405
406 (void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
407 /*
408 * NIT supports only ethernets.
409 */
410 p->linktype = DLT_EN10MB;
411
412 p->bufsize = BUFSPACE;
413 p->buffer = malloc(p->bufsize);
414 if (p->buffer == NULL) {
415 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
416 errno, "malloc");
417 err = PCAP_ERROR;
418 goto bad;
419 }
420
421 /*
422 * "p->fd" is an FD for a STREAMS device, so "select()" and
423 * "poll()" should work on it.
424 */
425 p->selectable_fd = p->fd;
426
427 /*
428 * This is (presumably) a real Ethernet capture; give it a
429 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
430 * that an application can let you choose it, in case you're
431 * capturing DOCSIS traffic that a Cisco Cable Modem
432 * Termination System is putting out onto an Ethernet (it
433 * doesn't put an Ethernet header onto the wire, it puts raw
434 * DOCSIS frames out on the wire inside the low-level
435 * Ethernet framing).
436 */
437 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
438 if (p->dlt_list == NULL) {
439 pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
440 errno, "malloc");
441 err = PCAP_ERROR;
442 goto bad;
443 }
444 p->dlt_list[0] = DLT_EN10MB;
445 p->dlt_list[1] = DLT_DOCSIS;
446 p->dlt_count = 2;
447
448 p->read_op = pcap_read_snit;
449 p->inject_op = pcap_inject_snit;
450 p->setfilter_op = pcapint_install_bpf_program; /* no kernel filtering */
451 p->setdirection_op = NULL; /* Not implemented. */
452 p->set_datalink_op = NULL; /* can't change data link type */
453 p->getnonblock_op = pcapint_getnonblock_fd;
454 p->setnonblock_op = pcapint_setnonblock_fd;
455 p->stats_op = pcap_stats_snit;
456
457 return (0);
458 bad:
459 pcapint_cleanup_live_common(p);
460 return (err);
461 }
462
463 pcap_t *
pcapint_create_interface(const char * device _U_,char * ebuf)464 pcapint_create_interface(const char *device _U_, char *ebuf)
465 {
466 pcap_t *p;
467
468 p = PCAP_CREATE_COMMON(ebuf, struct pcap_snit);
469 if (p == NULL)
470 return (NULL);
471
472 p->activate_op = pcap_activate_snit;
473 return (p);
474 }
475
476 /*
477 * XXX - there's probably a NIOCBIND error that means "that device
478 * doesn't support NIT"; if so, we should try an NIOCBIND and use that.
479 */
480 static int
can_be_bound(const char * name _U_)481 can_be_bound(const char *name _U_)
482 {
483 return (1);
484 }
485
486 static int
get_if_flags(const char * name _U_,bpf_u_int32 * flags _U_,char * errbuf _U_)487 get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)
488 {
489 /*
490 * Nothing we can do.
491 * XXX - is there a way to find out whether an adapter has
492 * something plugged into it?
493 */
494 return (0);
495 }
496
497 int
pcapint_platform_finddevs(pcap_if_list_t * devlistp,char * errbuf)498 pcapint_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
499 {
500 return (pcapint_findalldevs_interfaces(devlistp, errbuf, can_be_bound,
501 get_if_flags));
502 }
503
504 /*
505 * Libpcap version string.
506 */
507 const char *
pcap_lib_version(void)508 pcap_lib_version(void)
509 {
510 return (PCAP_VERSION_STRING);
511 }
512