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 #ifndef lint
27 static const char rcsid[] _U_ =
28     "@(#) $Header: /tcpdump/master/libpcap/pcap-snit.c,v 1.77 2008-04-14 20:40:58 guy Exp $ (LBL)";
29 #endif
30 
31 #ifdef HAVE_CONFIG_H
32 #include "config.h"
33 #endif
34 
35 #include <sys/types.h>
36 #include <sys/time.h>
37 #include <sys/timeb.h>
38 #include <sys/dir.h>
39 #include <sys/fcntlcom.h>
40 #include <sys/file.h>
41 #include <sys/ioctl.h>
42 #include <sys/socket.h>
43 #include <sys/stropts.h>
44 
45 #include <net/if.h>
46 #include <net/nit.h>
47 #include <net/nit_if.h>
48 #include <net/nit_pf.h>
49 #include <net/nit_buf.h>
50 
51 #include <netinet/in.h>
52 #include <netinet/in_systm.h>
53 #include <netinet/ip.h>
54 #include <netinet/if_ether.h>
55 #include <netinet/ip_var.h>
56 #include <netinet/udp.h>
57 #include <netinet/udp_var.h>
58 #include <netinet/tcp.h>
59 #include <netinet/tcpip.h>
60 
61 #include <ctype.h>
62 #include <errno.h>
63 #include <stdio.h>
64 #include <string.h>
65 #include <unistd.h>
66 
67 #include "pcap-int.h"
68 
69 #ifdef HAVE_OS_PROTO_H
70 #include "os-proto.h"
71 #endif
72 
73 /*
74  * The chunk size for NIT.  This is the amount of buffering
75  * done for read calls.
76  */
77 #define CHUNKSIZE (2*1024)
78 
79 /*
80  * The total buffer space used by NIT.
81  */
82 #define BUFSPACE (4*CHUNKSIZE)
83 
84 /* Forwards */
85 static int nit_setflags(int, int, int, char *);
86 
87 /*
88  * Private data for capturing on STREAMS NIT devices.
89  */
90 struct pcap_snit {
91 	struct pcap_stat stat;
92 };
93 
94 static int
pcap_stats_snit(pcap_t * p,struct pcap_stat * ps)95 pcap_stats_snit(pcap_t *p, struct pcap_stat *ps)
96 {
97 	struct pcap_snit *psn = p->priv;
98 
99 	/*
100 	 * "ps_recv" counts packets handed to the filter, not packets
101 	 * that passed the filter.  As filtering is done in userland,
102 	 * this does not include packets dropped because we ran out
103 	 * of buffer space.
104 	 *
105 	 * "ps_drop" counts packets dropped inside the "/dev/nit"
106 	 * device because of flow control requirements or resource
107 	 * exhaustion; it doesn't count packets dropped by the
108 	 * interface driver, or packets dropped upstream.  As filtering
109 	 * is done in userland, it counts packets regardless of whether
110 	 * they would've passed the filter.
111 	 *
112 	 * These statistics don't include packets not yet read from the
113 	 * kernel by libpcap or packets not yet read from libpcap by the
114 	 * application.
115 	 */
116 	*ps = psn->stat;
117 	return (0);
118 }
119 
120 static int
pcap_read_snit(pcap_t * p,int cnt,pcap_handler callback,u_char * user)121 pcap_read_snit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
122 {
123 	struct pcap_snit *psn = p->priv;
124 	register int cc, n;
125 	register u_char *bp, *cp, *ep;
126 	register struct nit_bufhdr *hdrp;
127 	register struct nit_iftime *ntp;
128 	register struct nit_iflen *nlp;
129 	register struct nit_ifdrops *ndp;
130 	register int caplen;
131 
132 	cc = p->cc;
133 	if (cc == 0) {
134 		cc = read(p->fd, (char *)p->buffer, p->bufsize);
135 		if (cc < 0) {
136 			if (errno == EWOULDBLOCK)
137 				return (0);
138 			snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
139 				pcap_strerror(errno));
140 			return (-1);
141 		}
142 		bp = p->buffer;
143 	} else
144 		bp = p->bp;
145 
146 	/*
147 	 * loop through each snapshot in the chunk
148 	 */
149 	n = 0;
150 	ep = bp + cc;
151 	while (bp < ep) {
152 		/*
153 		 * Has "pcap_breakloop()" been called?
154 		 * If so, return immediately - if we haven't read any
155 		 * packets, clear the flag and return -2 to indicate
156 		 * that we were told to break out of the loop, otherwise
157 		 * leave the flag set, so that the *next* call will break
158 		 * out of the loop without having read any packets, and
159 		 * return the number of packets we've processed so far.
160 		 */
161 		if (p->break_loop) {
162 			if (n == 0) {
163 				p->break_loop = 0;
164 				return (-2);
165 			} else {
166 				p->bp = bp;
167 				p->cc = ep - bp;
168 				return (n);
169 			}
170 		}
171 
172 		++psn->stat.ps_recv;
173 		cp = bp;
174 
175 		/* get past NIT buffer  */
176 		hdrp = (struct nit_bufhdr *)cp;
177 		cp += sizeof(*hdrp);
178 
179 		/* get past NIT timer   */
180 		ntp = (struct nit_iftime *)cp;
181 		cp += sizeof(*ntp);
182 
183 		ndp = (struct nit_ifdrops *)cp;
184 		psn->stat.ps_drop = ndp->nh_drops;
185 		cp += sizeof *ndp;
186 
187 		/* get past packet len  */
188 		nlp = (struct nit_iflen *)cp;
189 		cp += sizeof(*nlp);
190 
191 		/* next snapshot        */
192 		bp += hdrp->nhb_totlen;
193 
194 		caplen = nlp->nh_pktlen;
195 		if (caplen > p->snapshot)
196 			caplen = p->snapshot;
197 
198 		if (bpf_filter(p->fcode.bf_insns, cp, nlp->nh_pktlen, caplen)) {
199 			struct pcap_pkthdr h;
200 			h.ts = ntp->nh_timestamp;
201 			h.len = nlp->nh_pktlen;
202 			h.caplen = caplen;
203 			(*callback)(user, &h, cp);
204 			if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) {
205 				p->cc = ep - bp;
206 				p->bp = bp;
207 				return (n);
208 			}
209 		}
210 	}
211 	p->cc = 0;
212 	return (n);
213 }
214 
215 static int
pcap_inject_snit(pcap_t * p,const void * buf,size_t size)216 pcap_inject_snit(pcap_t *p, const void *buf, size_t size)
217 {
218 	struct strbuf ctl, data;
219 
220 	/*
221 	 * XXX - can we just do
222 	 *
223 	ret = write(pd->f, buf, size);
224 	 */
225 	ctl.len = sizeof(*sa);	/* XXX - what was this? */
226 	ctl.buf = (char *)sa;
227 	data.buf = buf;
228 	data.len = size;
229 	ret = putmsg(p->fd, &ctl, &data);
230 	if (ret == -1) {
231 		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
232 		    pcap_strerror(errno));
233 		return (-1);
234 	}
235 	return (ret);
236 }
237 
238 static int
nit_setflags(pcap_t * p)239 nit_setflags(pcap_t *p)
240 {
241 	bpf_u_int32 flags;
242 	struct strioctl si;
243 	u_int zero = 0;
244 	struct timeval timeout;
245 
246 	if (p->opt.immediate) {
247 		/*
248 		 * Set the chunk size to zero, so that chunks get sent
249 		 * up immediately.
250 		 */
251 		si.ic_cmd = NIOCSCHUNK;
252 		si.ic_len = sizeof(zero);
253 		si.ic_dp = (char *)&zero;
254 		if (ioctl(p->fd, I_STR, (char *)&si) < 0) {
255 			snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCSCHUNK: %s",
256 			    pcap_strerror(errno));
257 			return (-1);
258 		}
259 	}
260 	si.ic_timout = INFTIM;
261 	if (p->opt.timeout != 0) {
262 		timeout.tv_sec = p->opt.timeout / 1000;
263 		timeout.tv_usec = (p->opt.timeout * 1000) % 1000000;
264 		si.ic_cmd = NIOCSTIME;
265 		si.ic_len = sizeof(timeout);
266 		si.ic_dp = (char *)&timeout;
267 		if (ioctl(p->fd, I_STR, (char *)&si) < 0) {
268 			snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCSTIME: %s",
269 			    pcap_strerror(errno));
270 			return (-1);
271 		}
272 	}
273 	flags = NI_TIMESTAMP | NI_LEN | NI_DROPS;
274 	if (p->opt.promisc)
275 		flags |= NI_PROMISC;
276 	si.ic_cmd = NIOCSFLAGS;
277 	si.ic_len = sizeof(flags);
278 	si.ic_dp = (char *)&flags;
279 	if (ioctl(p->fd, I_STR, (char *)&si) < 0) {
280 		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCSFLAGS: %s",
281 		    pcap_strerror(errno));
282 		return (-1);
283 	}
284 	return (0);
285 }
286 
287 static int
pcap_activate_snit(pcap_t * p)288 pcap_activate_snit(pcap_t *p)
289 {
290 	struct strioctl si;		/* struct for ioctl() */
291 	struct ifreq ifr;		/* interface request struct */
292 	int chunksize = CHUNKSIZE;
293 	int fd;
294 	static char dev[] = "/dev/nit";
295 
296 	if (p->opt.rfmon) {
297 		/*
298 		 * No monitor mode on SunOS 4.x (no Wi-Fi devices on
299 		 * hardware supported by SunOS 4.x).
300 		 */
301 		return (PCAP_ERROR_RFMON_NOTSUP);
302 	}
303 
304 	if (p->snapshot < 96)
305 		/*
306 		 * NIT requires a snapshot length of at least 96.
307 		 */
308 		p->snapshot = 96;
309 
310 	/*
311 	 * Initially try a read/write open (to allow the inject
312 	 * method to work).  If that fails due to permission
313 	 * issues, fall back to read-only.  This allows a
314 	 * non-root user to be granted specific access to pcap
315 	 * capabilities via file permissions.
316 	 *
317 	 * XXX - we should have an API that has a flag that
318 	 * controls whether to open read-only or read-write,
319 	 * so that denial of permission to send (or inability
320 	 * to send, if sending packets isn't supported on
321 	 * the device in question) can be indicated at open
322 	 * time.
323 	 */
324 	p->fd = fd = open(dev, O_RDWR);
325 	if (fd < 0 && errno == EACCES)
326 		p->fd = fd = open(dev, O_RDONLY);
327 	if (fd < 0) {
328 		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s: %s", dev,
329 		    pcap_strerror(errno));
330 		goto bad;
331 	}
332 
333 	/* arrange to get discrete messages from the STREAM and use NIT_BUF */
334 	if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
335 		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "I_SRDOPT: %s",
336 		    pcap_strerror(errno));
337 		goto bad;
338 	}
339 	if (ioctl(fd, I_PUSH, "nbuf") < 0) {
340 		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "push nbuf: %s",
341 		    pcap_strerror(errno));
342 		goto bad;
343 	}
344 	/* set the chunksize */
345 	si.ic_cmd = NIOCSCHUNK;
346 	si.ic_timout = INFTIM;
347 	si.ic_len = sizeof(chunksize);
348 	si.ic_dp = (char *)&chunksize;
349 	if (ioctl(fd, I_STR, (char *)&si) < 0) {
350 		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCSCHUNK: %s",
351 		    pcap_strerror(errno));
352 		goto bad;
353 	}
354 
355 	/* request the interface */
356 	strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name));
357 	ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
358 	si.ic_cmd = NIOCBIND;
359 	si.ic_len = sizeof(ifr);
360 	si.ic_dp = (char *)&ifr;
361 	if (ioctl(fd, I_STR, (char *)&si) < 0) {
362 		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCBIND: %s: %s",
363 			ifr.ifr_name, pcap_strerror(errno));
364 		goto bad;
365 	}
366 
367 	/* set the snapshot length */
368 	si.ic_cmd = NIOCSSNAP;
369 	si.ic_len = sizeof(p->snapshot);
370 	si.ic_dp = (char *)&p->snapshot;
371 	if (ioctl(fd, I_STR, (char *)&si) < 0) {
372 		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCSSNAP: %s",
373 		    pcap_strerror(errno));
374 		goto bad;
375 	}
376 	if (nit_setflags(p) < 0)
377 		goto bad;
378 
379 	(void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
380 	/*
381 	 * NIT supports only ethernets.
382 	 */
383 	p->linktype = DLT_EN10MB;
384 
385 	p->bufsize = BUFSPACE;
386 	p->buffer = (u_char *)malloc(p->bufsize);
387 	if (p->buffer == NULL) {
388 		strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
389 		goto bad;
390 	}
391 
392 	/*
393 	 * "p->fd" is an FD for a STREAMS device, so "select()" and
394 	 * "poll()" should work on it.
395 	 */
396 	p->selectable_fd = p->fd;
397 
398 	/*
399 	 * This is (presumably) a real Ethernet capture; give it a
400 	 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
401 	 * that an application can let you choose it, in case you're
402 	 * capturing DOCSIS traffic that a Cisco Cable Modem
403 	 * Termination System is putting out onto an Ethernet (it
404 	 * doesn't put an Ethernet header onto the wire, it puts raw
405 	 * DOCSIS frames out on the wire inside the low-level
406 	 * Ethernet framing).
407 	 */
408 	p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
409 	/*
410 	 * If that fails, just leave the list empty.
411 	 */
412 	if (p->dlt_list != NULL) {
413 		p->dlt_list[0] = DLT_EN10MB;
414 		p->dlt_list[1] = DLT_DOCSIS;
415 		p->dlt_count = 2;
416 	}
417 
418 	p->read_op = pcap_read_snit;
419 	p->inject_op = pcap_inject_snit;
420 	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
421 	p->setdirection_op = NULL;	/* Not implemented. */
422 	p->set_datalink_op = NULL;	/* can't change data link type */
423 	p->getnonblock_op = pcap_getnonblock_fd;
424 	p->setnonblock_op = pcap_setnonblock_fd;
425 	p->stats_op = pcap_stats_snit;
426 
427 	return (0);
428  bad:
429 	pcap_cleanup_live_common(p);
430 	return (PCAP_ERROR);
431 }
432 
433 pcap_t *
pcap_create_interface(const char * device,char * ebuf)434 pcap_create_interface(const char *device, char *ebuf)
435 {
436 	pcap_t *p;
437 
438 	p = pcap_create_common(device, ebuf, sizeof (struct pcap_snit));
439 	if (p == NULL)
440 		return (NULL);
441 
442 	p->activate_op = pcap_activate_snit;
443 	return (p);
444 }
445 
446 int
pcap_platform_finddevs(pcap_if_t ** alldevsp,char * errbuf)447 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
448 {
449 	return (0);
450 }
451