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#ifndef lint
22static const char rcsid[] _U_ =
23    "@(#) $Header: /tcpdump/master/libpcap/pcap-nit.c,v 1.62 2008-04-14 20:40:58 guy Exp $ (LBL)";
24#endif
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/file.h>
34#include <sys/ioctl.h>
35#include <sys/socket.h>
36
37#include <net/if.h>
38#include <net/nit.h>
39
40#include <netinet/in.h>
41#include <netinet/in_systm.h>
42#include <netinet/ip.h>
43#include <netinet/if_ether.h>
44#include <netinet/ip_var.h>
45#include <netinet/udp.h>
46#include <netinet/udp_var.h>
47#include <netinet/tcp.h>
48#include <netinet/tcpip.h>
49
50#include <ctype.h>
51#include <errno.h>
52#include <stdio.h>
53
54#include "pcap-int.h"
55
56#ifdef HAVE_OS_PROTO_H
57#include "os-proto.h"
58#endif
59
60/*
61 * The chunk size for NIT.  This is the amount of buffering
62 * done for read calls.
63 */
64#define CHUNKSIZE (2*1024)
65
66/*
67 * The total buffer space used by NIT.
68 */
69#define BUFSPACE (4*CHUNKSIZE)
70
71/* Forwards */
72static int nit_setflags(int, int, int, char *);
73
74static int
75pcap_stats_nit(pcap_t *p, struct pcap_stat *ps)
76{
77
78	/*
79	 * "ps_recv" counts packets handed to the filter, not packets
80	 * that passed the filter.  As filtering is done in userland,
81	 * this does not include packets dropped because we ran out
82	 * of buffer space.
83	 *
84	 * "ps_drop" presumably counts packets dropped by the socket
85	 * because of flow control requirements or resource exhaustion;
86	 * it doesn't count packets dropped by the interface driver.
87	 * As filtering is done in userland, it counts packets regardless
88	 * of whether they would've passed the filter.
89	 *
90	 * These statistics don't include packets not yet read from the
91	 * kernel by libpcap or packets not yet read from libpcap by the
92	 * application.
93	 */
94	*ps = p->md.stat;
95	return (0);
96}
97
98static int
99pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
100{
101	register int cc, n;
102	register u_char *bp, *cp, *ep;
103	register struct nit_hdr *nh;
104	register int caplen;
105
106	cc = p->cc;
107	if (cc == 0) {
108		cc = read(p->fd, (char *)p->buffer, p->bufsize);
109		if (cc < 0) {
110			if (errno == EWOULDBLOCK)
111				return (0);
112			snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
113				pcap_strerror(errno));
114			return (-1);
115		}
116		bp = p->buffer;
117	} else
118		bp = p->bp;
119
120	/*
121	 * Loop through each packet.  The increment expression
122	 * rounds up to the next int boundary past the end of
123	 * the previous packet.
124	 */
125	n = 0;
126	ep = bp + cc;
127	while (bp < ep) {
128		/*
129		 * Has "pcap_breakloop()" been called?
130		 * If so, return immediately - if we haven't read any
131		 * packets, clear the flag and return -2 to indicate
132		 * that we were told to break out of the loop, otherwise
133		 * leave the flag set, so that the *next* call will break
134		 * out of the loop without having read any packets, and
135		 * return the number of packets we've processed so far.
136		 */
137		if (p->break_loop) {
138			if (n == 0) {
139				p->break_loop = 0;
140				return (-2);
141			} else {
142				p->cc = ep - bp;
143				p->bp = bp;
144				return (n);
145			}
146		}
147
148		nh = (struct nit_hdr *)bp;
149		cp = bp + sizeof(*nh);
150
151		switch (nh->nh_state) {
152
153		case NIT_CATCH:
154			break;
155
156		case NIT_NOMBUF:
157		case NIT_NOCLUSTER:
158		case NIT_NOSPACE:
159			p->md.stat.ps_drop = nh->nh_dropped;
160			continue;
161
162		case NIT_SEQNO:
163			continue;
164
165		default:
166			snprintf(p->errbuf, sizeof(p->errbuf),
167			    "bad nit state %d", nh->nh_state);
168			return (-1);
169		}
170		++p->md.stat.ps_recv;
171		bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
172		    sizeof(int) - 1) & ~(sizeof(int) - 1));
173
174		caplen = nh->nh_wirelen;
175		if (caplen > p->snapshot)
176			caplen = p->snapshot;
177		if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) {
178			struct pcap_pkthdr h;
179			h.ts = nh->nh_timestamp;
180			h.len = nh->nh_wirelen;
181			h.caplen = caplen;
182			(*callback)(user, &h, cp);
183			if (++n >= cnt && cnt > 0) {
184				p->cc = ep - bp;
185				p->bp = bp;
186				return (n);
187			}
188		}
189	}
190	p->cc = 0;
191	return (n);
192}
193
194static int
195pcap_inject_nit(pcap_t *p, const void *buf, size_t size)
196{
197	struct sockaddr sa;
198	int ret;
199
200	memset(&sa, 0, sizeof(sa));
201	strncpy(sa.sa_data, device, sizeof(sa.sa_data));
202	ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa));
203	if (ret == -1) {
204		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
205		    pcap_strerror(errno));
206		return (-1);
207	}
208	return (ret);
209}
210
211static int
212nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
213{
214	struct nit_ioc nioc;
215
216	memset(&nioc, 0, sizeof(nioc));
217	nioc.nioc_bufspace = BUFSPACE;
218	nioc.nioc_chunksize = CHUNKSIZE;
219	nioc.nioc_typetomatch = NT_ALLTYPES;
220	nioc.nioc_snaplen = p->snapshot;
221	nioc.nioc_bufalign = sizeof(int);
222	nioc.nioc_bufoffset = 0;
223
224	if (to_ms != 0) {
225		nioc.nioc_flags |= NF_TIMEOUT;
226		nioc.nioc_timeout.tv_sec = to_ms / 1000;
227		nioc.nioc_timeout.tv_usec = (to_ms * 1000) % 1000000;
228	}
229	if (promisc)
230		nioc.nioc_flags |= NF_PROMISC;
231
232	if (ioctl(fd, SIOCSNIT, &nioc) < 0) {
233		snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s",
234		    pcap_strerror(errno));
235		return (-1);
236	}
237	return (0);
238}
239
240static int
241pcap_activate_nit(pcap_t *p)
242{
243	int fd;
244	struct sockaddr_nit snit;
245
246	if (p->opt.rfmon) {
247		/*
248		 * No monitor mode on SunOS 3.x or earlier (no
249		 * Wi-Fi *devices* for the hardware that supported
250		 * them!).
251		 */
252		return (PCAP_ERROR_RFMON_NOTSUP);
253	}
254
255	if (p->snapshot < 96)
256		/*
257		 * NIT requires a snapshot length of at least 96.
258		 */
259		p->snapshot = 96;
260
261	memset(p, 0, sizeof(*p));
262	p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
263	if (fd < 0) {
264		snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
265		    "socket: %s", pcap_strerror(errno));
266		goto bad;
267	}
268	snit.snit_family = AF_NIT;
269	(void)strncpy(snit.snit_ifname, p->opt.source, NITIFSIZ);
270
271	if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
272		snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
273		    "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno));
274		goto bad;
275	}
276	nit_setflags(p->fd, p->opt.promisc, p->md.timeout, p->errbuf);
277
278	/*
279	 * NIT supports only ethernets.
280	 */
281	p->linktype = DLT_EN10MB;
282
283	p->bufsize = BUFSPACE;
284	p->buffer = (u_char *)malloc(p->bufsize);
285	if (p->buffer == NULL) {
286		strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
287		goto bad;
288	}
289
290	/*
291	 * "p->fd" is a socket, so "select()" should work on it.
292	 */
293	p->selectable_fd = p->fd;
294
295	/*
296	 * This is (presumably) a real Ethernet capture; give it a
297	 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
298	 * that an application can let you choose it, in case you're
299	 * capturing DOCSIS traffic that a Cisco Cable Modem
300	 * Termination System is putting out onto an Ethernet (it
301	 * doesn't put an Ethernet header onto the wire, it puts raw
302	 * DOCSIS frames out on the wire inside the low-level
303	 * Ethernet framing).
304	 */
305	p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
306	/*
307	 * If that fails, just leave the list empty.
308	 */
309	if (p->dlt_list != NULL) {
310		p->dlt_list[0] = DLT_EN10MB;
311		p->dlt_list[1] = DLT_DOCSIS;
312		p->dlt_count = 2;
313	}
314
315	p->read_op = pcap_read_nit;
316	p->inject_op = pcap_inject_nit;
317	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
318	p->setdirection_op = NULL;	/* Not implemented. */
319	p->set_datalink_op = NULL;	/* can't change data link type */
320	p->getnonblock_op = pcap_getnonblock_fd;
321	p->setnonblock_op = pcap_setnonblock_fd;
322	p->stats_op = pcap_stats_nit;
323
324	return (0);
325 bad:
326	pcap_cleanup_live_common(p);
327	return (PCAP_ERROR);
328}
329
330pcap_t *
331pcap_create_interface(const char *device, char *ebuf)
332{
333	pcap_t *p;
334
335	p = pcap_create_common(device, ebuf);
336	if (p == NULL)
337		return (NULL);
338
339	p->activate_op = pcap_activate_nit;
340	return (p);
341}
342
343int
344pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
345{
346	return (0);
347}
348