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
27static 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 */
85static int nit_setflags(int, int, int, char *);
86
87static int
88pcap_stats_snit(pcap_t *p, struct pcap_stat *ps)
89{
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 = p->md.stat;
109	return (0);
110}
111
112static int
113pcap_read_snit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
114{
115	register int cc, n;
116	register u_char *bp, *cp, *ep;
117	register struct nit_bufhdr *hdrp;
118	register struct nit_iftime *ntp;
119	register struct nit_iflen *nlp;
120	register struct nit_ifdrops *ndp;
121	register int caplen;
122
123	cc = p->cc;
124	if (cc == 0) {
125		cc = read(p->fd, (char *)p->buffer, p->bufsize);
126		if (cc < 0) {
127			if (errno == EWOULDBLOCK)
128				return (0);
129			snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
130				pcap_strerror(errno));
131			return (-1);
132		}
133		bp = p->buffer;
134	} else
135		bp = p->bp;
136
137	/*
138	 * loop through each snapshot in the chunk
139	 */
140	n = 0;
141	ep = bp + cc;
142	while (bp < ep) {
143		/*
144		 * Has "pcap_breakloop()" been called?
145		 * If so, return immediately - if we haven't read any
146		 * packets, clear the flag and return -2 to indicate
147		 * that we were told to break out of the loop, otherwise
148		 * leave the flag set, so that the *next* call will break
149		 * out of the loop without having read any packets, and
150		 * return the number of packets we've processed so far.
151		 */
152		if (p->break_loop) {
153			if (n == 0) {
154				p->break_loop = 0;
155				return (-2);
156			} else {
157				p->bp = bp;
158				p->cc = ep - bp;
159				return (n);
160			}
161		}
162
163		++p->md.stat.ps_recv;
164		cp = bp;
165
166		/* get past NIT buffer  */
167		hdrp = (struct nit_bufhdr *)cp;
168		cp += sizeof(*hdrp);
169
170		/* get past NIT timer   */
171		ntp = (struct nit_iftime *)cp;
172		cp += sizeof(*ntp);
173
174		ndp = (struct nit_ifdrops *)cp;
175		p->md.stat.ps_drop = ndp->nh_drops;
176		cp += sizeof *ndp;
177
178		/* get past packet len  */
179		nlp = (struct nit_iflen *)cp;
180		cp += sizeof(*nlp);
181
182		/* next snapshot        */
183		bp += hdrp->nhb_totlen;
184
185		caplen = nlp->nh_pktlen;
186		if (caplen > p->snapshot)
187			caplen = p->snapshot;
188
189		if (bpf_filter(p->fcode.bf_insns, cp, nlp->nh_pktlen, caplen)) {
190			struct pcap_pkthdr h;
191			h.ts = ntp->nh_timestamp;
192			h.len = nlp->nh_pktlen;
193			h.caplen = caplen;
194			(*callback)(user, &h, cp);
195			if (++n >= cnt && cnt > 0) {
196				p->cc = ep - bp;
197				p->bp = bp;
198				return (n);
199			}
200		}
201	}
202	p->cc = 0;
203	return (n);
204}
205
206static int
207pcap_inject_snit(pcap_t *p, const void *buf, size_t size)
208{
209	struct strbuf ctl, data;
210
211	/*
212	 * XXX - can we just do
213	 *
214	ret = write(pd->f, buf, size);
215	 */
216	ctl.len = sizeof(*sa);	/* XXX - what was this? */
217	ctl.buf = (char *)sa;
218	data.buf = buf;
219	data.len = size;
220	ret = putmsg(p->fd, &ctl, &data);
221	if (ret == -1) {
222		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
223		    pcap_strerror(errno));
224		return (-1);
225	}
226	return (ret);
227}
228
229static int
230nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
231{
232	bpf_u_int32 flags;
233	struct strioctl si;
234	struct timeval timeout;
235
236	si.ic_timout = INFTIM;
237	if (to_ms != 0) {
238		timeout.tv_sec = to_ms / 1000;
239		timeout.tv_usec = (to_ms * 1000) % 1000000;
240		si.ic_cmd = NIOCSTIME;
241		si.ic_len = sizeof(timeout);
242		si.ic_dp = (char *)&timeout;
243		if (ioctl(fd, I_STR, (char *)&si) < 0) {
244			snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSTIME: %s",
245			    pcap_strerror(errno));
246			return (-1);
247		}
248	}
249	flags = NI_TIMESTAMP | NI_LEN | NI_DROPS;
250	if (promisc)
251		flags |= NI_PROMISC;
252	si.ic_cmd = NIOCSFLAGS;
253	si.ic_len = sizeof(flags);
254	si.ic_dp = (char *)&flags;
255	if (ioctl(fd, I_STR, (char *)&si) < 0) {
256		snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSFLAGS: %s",
257		    pcap_strerror(errno));
258		return (-1);
259	}
260	return (0);
261}
262
263static int
264pcap_activate_snit(pcap_t *p)
265{
266	struct strioctl si;		/* struct for ioctl() */
267	struct ifreq ifr;		/* interface request struct */
268	int chunksize = CHUNKSIZE;
269	int fd;
270	static char dev[] = "/dev/nit";
271
272	if (p->opt.rfmon) {
273		/*
274		 * No monitor mode on SunOS 4.x (no Wi-Fi devices on
275		 * hardware supported by SunOS 4.x).
276		 */
277		return (PCAP_ERROR_RFMON_NOTSUP);
278	}
279
280	if (p->snapshot < 96)
281		/*
282		 * NIT requires a snapshot length of at least 96.
283		 */
284		p->snapshot = 96;
285
286	/*
287	 * Initially try a read/write open (to allow the inject
288	 * method to work).  If that fails due to permission
289	 * issues, fall back to read-only.  This allows a
290	 * non-root user to be granted specific access to pcap
291	 * capabilities via file permissions.
292	 *
293	 * XXX - we should have an API that has a flag that
294	 * controls whether to open read-only or read-write,
295	 * so that denial of permission to send (or inability
296	 * to send, if sending packets isn't supported on
297	 * the device in question) can be indicated at open
298	 * time.
299	 */
300	p->fd = fd = open(dev, O_RDWR);
301	if (fd < 0 && errno == EACCES)
302		p->fd = fd = open(dev, O_RDONLY);
303	if (fd < 0) {
304		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s: %s", dev,
305		    pcap_strerror(errno));
306		goto bad;
307	}
308
309	/* arrange to get discrete messages from the STREAM and use NIT_BUF */
310	if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
311		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "I_SRDOPT: %s",
312		    pcap_strerror(errno));
313		goto bad;
314	}
315	if (ioctl(fd, I_PUSH, "nbuf") < 0) {
316		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "push nbuf: %s",
317		    pcap_strerror(errno));
318		goto bad;
319	}
320	/* set the chunksize */
321	si.ic_cmd = NIOCSCHUNK;
322	si.ic_timout = INFTIM;
323	si.ic_len = sizeof(chunksize);
324	si.ic_dp = (char *)&chunksize;
325	if (ioctl(fd, I_STR, (char *)&si) < 0) {
326		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCSCHUNK: %s",
327		    pcap_strerror(errno));
328		goto bad;
329	}
330
331	/* request the interface */
332	strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name));
333	ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
334	si.ic_cmd = NIOCBIND;
335	si.ic_len = sizeof(ifr);
336	si.ic_dp = (char *)&ifr;
337	if (ioctl(fd, I_STR, (char *)&si) < 0) {
338		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCBIND: %s: %s",
339			ifr.ifr_name, pcap_strerror(errno));
340		goto bad;
341	}
342
343	/* set the snapshot length */
344	si.ic_cmd = NIOCSSNAP;
345	si.ic_len = sizeof(p->snapshot);
346	si.ic_dp = (char *)&p->snapshot;
347	if (ioctl(fd, I_STR, (char *)&si) < 0) {
348		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "NIOCSSNAP: %s",
349		    pcap_strerror(errno));
350		goto bad;
351	}
352	if (nit_setflags(p->fd, p->opt.promisc, p->md.timeout, p->errbuf) < 0)
353		goto bad;
354
355	(void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
356	/*
357	 * NIT supports only ethernets.
358	 */
359	p->linktype = DLT_EN10MB;
360
361	p->bufsize = BUFSPACE;
362	p->buffer = (u_char *)malloc(p->bufsize);
363	if (p->buffer == NULL) {
364		strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
365		goto bad;
366	}
367
368	/*
369	 * "p->fd" is an FD for a STREAMS device, so "select()" and
370	 * "poll()" should work on it.
371	 */
372	p->selectable_fd = p->fd;
373
374	/*
375	 * This is (presumably) a real Ethernet capture; give it a
376	 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
377	 * that an application can let you choose it, in case you're
378	 * capturing DOCSIS traffic that a Cisco Cable Modem
379	 * Termination System is putting out onto an Ethernet (it
380	 * doesn't put an Ethernet header onto the wire, it puts raw
381	 * DOCSIS frames out on the wire inside the low-level
382	 * Ethernet framing).
383	 */
384	p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
385	/*
386	 * If that fails, just leave the list empty.
387	 */
388	if (p->dlt_list != NULL) {
389		p->dlt_list[0] = DLT_EN10MB;
390		p->dlt_list[1] = DLT_DOCSIS;
391		p->dlt_count = 2;
392	}
393
394	p->read_op = pcap_read_snit;
395	p->inject_op = pcap_inject_snit;
396	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
397	p->setdirection_op = NULL;	/* Not implemented. */
398	p->set_datalink_op = NULL;	/* can't change data link type */
399	p->getnonblock_op = pcap_getnonblock_fd;
400	p->setnonblock_op = pcap_setnonblock_fd;
401	p->stats_op = pcap_stats_snit;
402
403	return (0);
404 bad:
405	pcap_cleanup_live_common(p);
406	return (PCAP_ERROR);
407}
408
409pcap_t *
410pcap_create(const char *device, char *ebuf)
411{
412	pcap_t *p;
413
414	p = pcap_create_common(device, ebuf);
415	if (p == NULL)
416		return (NULL);
417
418	p->activate_op = pcap_activate_snit;
419	return (p);
420}
421
422int
423pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
424{
425	return (0);
426}
427