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
22#ifdef HAVE_CONFIG_H
23#include <config.h>
24#endif
25
26#include <sys/types.h>
27#include <sys/time.h>
28#include <sys/timeb.h>
29#include <sys/file.h>
30#include <sys/ioctl.h>
31#include <sys/socket.h>
32
33#include <net/if.h>
34#include <net/nit.h>
35
36#include <netinet/in.h>
37#include <netinet/in_systm.h>
38#include <netinet/ip.h>
39#include <netinet/if_ether.h>
40#include <netinet/ip_var.h>
41#include <netinet/udp.h>
42#include <netinet/udp_var.h>
43#include <netinet/tcp.h>
44#include <netinet/tcpip.h>
45
46#include <errno.h>
47#include <stdio.h>
48
49#include "pcap-int.h"
50
51#ifdef HAVE_OS_PROTO_H
52#include "os-proto.h"
53#endif
54
55/*
56 * The chunk size for NIT.  This is the amount of buffering
57 * done for read calls.
58 */
59#define CHUNKSIZE (2*1024)
60
61/*
62 * The total buffer space used by NIT.
63 */
64#define BUFSPACE (4*CHUNKSIZE)
65
66/* Forwards */
67static int nit_setflags(int, int, int, char *);
68
69/*
70 * Private data for capturing on NIT devices.
71 */
72struct pcap_nit {
73	struct pcap_stat stat;
74};
75
76static int
77pcap_stats_nit(pcap_t *p, struct pcap_stat *ps)
78{
79	struct pcap_nit *pn = p->priv;
80
81	/*
82	 * "ps_recv" counts packets handed to the filter, not packets
83	 * that passed the filter.  As filtering is done in userland,
84	 * this does not include packets dropped because we ran out
85	 * of buffer space.
86	 *
87	 * "ps_drop" presumably counts packets dropped by the socket
88	 * because of flow control requirements or resource exhaustion;
89	 * it doesn't count packets dropped by the interface driver.
90	 * As filtering is done in userland, it counts packets regardless
91	 * of whether they would've passed the filter.
92	 *
93	 * These statistics don't include packets not yet read from the
94	 * kernel by libpcap or packets not yet read from libpcap by the
95	 * application.
96	 */
97	*ps = pn->stat;
98	return (0);
99}
100
101static int
102pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
103{
104	struct pcap_nit *pn = p->priv;
105	register int cc, n;
106	register u_char *bp, *cp, *ep;
107	register struct nit_hdr *nh;
108	register int caplen;
109
110	cc = p->cc;
111	if (cc == 0) {
112		cc = read(p->fd, (char *)p->buffer, p->bufsize);
113		if (cc < 0) {
114			if (errno == EWOULDBLOCK)
115				return (0);
116			pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
117			    errno, "pcap_read");
118			return (-1);
119		}
120		bp = (u_char *)p->buffer;
121	} else
122		bp = p->bp;
123
124	/*
125	 * Loop through each packet.  The increment expression
126	 * rounds up to the next int boundary past the end of
127	 * the previous packet.
128	 *
129	 * This assumes that a single buffer of packets will have
130	 * <= INT_MAX packets, so the packet count doesn't overflow.
131	 */
132	n = 0;
133	ep = bp + cc;
134	while (bp < ep) {
135		/*
136		 * Has "pcap_breakloop()" been called?
137		 * If so, return immediately - if we haven't read any
138		 * packets, clear the flag and return -2 to indicate
139		 * that we were told to break out of the loop, otherwise
140		 * leave the flag set, so that the *next* call will break
141		 * out of the loop without having read any packets, and
142		 * return the number of packets we've processed so far.
143		 */
144		if (p->break_loop) {
145			if (n == 0) {
146				p->break_loop = 0;
147				return (-2);
148			} else {
149				p->cc = ep - bp;
150				p->bp = bp;
151				return (n);
152			}
153		}
154
155		nh = (struct nit_hdr *)bp;
156		cp = bp + sizeof(*nh);
157
158		switch (nh->nh_state) {
159
160		case NIT_CATCH:
161			break;
162
163		case NIT_NOMBUF:
164		case NIT_NOCLUSTER:
165		case NIT_NOSPACE:
166			pn->stat.ps_drop = nh->nh_dropped;
167			continue;
168
169		case NIT_SEQNO:
170			continue;
171
172		default:
173			snprintf(p->errbuf, sizeof(p->errbuf),
174			    "bad nit state %d", nh->nh_state);
175			return (-1);
176		}
177		++pn->stat.ps_recv;
178		bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
179		    sizeof(int) - 1) & ~(sizeof(int) - 1));
180
181		caplen = nh->nh_wirelen;
182		if (caplen > p->snapshot)
183			caplen = p->snapshot;
184		if (pcap_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) {
185			struct pcap_pkthdr h;
186			h.ts = nh->nh_timestamp;
187			h.len = nh->nh_wirelen;
188			h.caplen = caplen;
189			(*callback)(user, &h, cp);
190			if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) {
191				p->cc = ep - bp;
192				p->bp = bp;
193				return (n);
194			}
195		}
196	}
197	p->cc = 0;
198	return (n);
199}
200
201static int
202pcap_inject_nit(pcap_t *p, const void *buf, int size)
203{
204	struct sockaddr sa;
205	int ret;
206
207	memset(&sa, 0, sizeof(sa));
208	strncpy(sa.sa_data, device, sizeof(sa.sa_data));
209	ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa));
210	if (ret == -1) {
211		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
212		    errno, "send");
213		return (-1);
214	}
215	return (ret);
216}
217
218static int
219nit_setflags(pcap_t *p)
220{
221	struct nit_ioc nioc;
222
223	memset(&nioc, 0, sizeof(nioc));
224	nioc.nioc_typetomatch = NT_ALLTYPES;
225	nioc.nioc_snaplen = p->snapshot;
226	nioc.nioc_bufalign = sizeof(int);
227	nioc.nioc_bufoffset = 0;
228
229	if (p->opt.buffer_size != 0)
230		nioc.nioc_bufspace = p->opt.buffer_size;
231	else {
232		/* Default buffer size */
233		nioc.nioc_bufspace = BUFSPACE;
234	}
235
236	if (p->opt.immediate) {
237		/*
238		 * XXX - will this cause packets to be delivered immediately?
239		 * XXX - given that this is for SunOS prior to 4.0, do
240		 * we care?
241		 */
242		nioc.nioc_chunksize = 0;
243	} else
244		nioc.nioc_chunksize = CHUNKSIZE;
245	if (p->opt.timeout != 0) {
246		nioc.nioc_flags |= NF_TIMEOUT;
247		nioc.nioc_timeout.tv_sec = p->opt.timeout / 1000;
248		nioc.nioc_timeout.tv_usec = (p->opt.timeout * 1000) % 1000000;
249	}
250	if (p->opt.promisc)
251		nioc.nioc_flags |= NF_PROMISC;
252
253	if (ioctl(p->fd, SIOCSNIT, &nioc) < 0) {
254		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
255		    errno, "SIOCSNIT");
256		return (-1);
257	}
258	return (0);
259}
260
261static int
262pcap_activate_nit(pcap_t *p)
263{
264	int fd;
265	struct sockaddr_nit snit;
266
267	if (p->opt.rfmon) {
268		/*
269		 * No monitor mode on SunOS 3.x or earlier (no
270		 * Wi-Fi *devices* for the hardware that supported
271		 * them!).
272		 */
273		return (PCAP_ERROR_RFMON_NOTSUP);
274	}
275
276	/*
277	 * Turn a negative snapshot value (invalid), a snapshot value of
278	 * 0 (unspecified), or a value bigger than the normal maximum
279	 * value, into the maximum allowed value.
280	 *
281	 * If some application really *needs* a bigger snapshot
282	 * length, we should just increase MAXIMUM_SNAPLEN.
283	 */
284	if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
285		p->snapshot = MAXIMUM_SNAPLEN;
286
287	if (p->snapshot < 96)
288		/*
289		 * NIT requires a snapshot length of at least 96.
290		 */
291		p->snapshot = 96;
292
293	memset(p, 0, sizeof(*p));
294	p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
295	if (fd < 0) {
296		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
297		    errno, "socket");
298		goto bad;
299	}
300	snit.snit_family = AF_NIT;
301	(void)strncpy(snit.snit_ifname, p->opt.device, NITIFSIZ);
302
303	if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
304		/*
305		 * XXX - there's probably a particular bind error that
306		 * means "there's no such device" and a particular bind
307		 * error that means "that device doesn't support NIT";
308		 * they might be the same error, if they both end up
309		 * meaning "NIT doesn't know about that device".
310		 */
311		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
312		    errno, "bind: %s", snit.snit_ifname);
313		goto bad;
314	}
315	if (nit_setflags(p) < 0)
316		goto bad;
317
318	/*
319	 * NIT supports only ethernets.
320	 */
321	p->linktype = DLT_EN10MB;
322
323	p->bufsize = BUFSPACE;
324	p->buffer = malloc(p->bufsize);
325	if (p->buffer == NULL) {
326		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
327		    errno, "malloc");
328		goto bad;
329	}
330
331	/*
332	 * "p->fd" is a socket, so "select()" should work on it.
333	 */
334	p->selectable_fd = p->fd;
335
336	/*
337	 * This is (presumably) a real Ethernet capture; give it a
338	 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
339	 * that an application can let you choose it, in case you're
340	 * capturing DOCSIS traffic that a Cisco Cable Modem
341	 * Termination System is putting out onto an Ethernet (it
342	 * doesn't put an Ethernet header onto the wire, it puts raw
343	 * DOCSIS frames out on the wire inside the low-level
344	 * Ethernet framing).
345	 */
346	p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
347	/*
348	 * If that fails, just leave the list empty.
349	 */
350	if (p->dlt_list != NULL) {
351		p->dlt_list[0] = DLT_EN10MB;
352		p->dlt_list[1] = DLT_DOCSIS;
353		p->dlt_count = 2;
354	}
355
356	p->read_op = pcap_read_nit;
357	p->inject_op = pcap_inject_nit;
358	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
359	p->setdirection_op = NULL;	/* Not implemented. */
360	p->set_datalink_op = NULL;	/* can't change data link type */
361	p->getnonblock_op = pcap_getnonblock_fd;
362	p->setnonblock_op = pcap_setnonblock_fd;
363	p->stats_op = pcap_stats_nit;
364
365	return (0);
366 bad:
367	pcap_cleanup_live_common(p);
368	return (PCAP_ERROR);
369}
370
371pcap_t *
372pcap_create_interface(const char *device _U_, char *ebuf)
373{
374	pcap_t *p;
375
376	p = PCAP_CREATE_COMMON(ebuf, struct pcap_nit);
377	if (p == NULL)
378		return (NULL);
379
380	p->activate_op = pcap_activate_nit;
381	return (p);
382}
383
384/*
385 * XXX - there's probably a particular bind error that means "that device
386 * doesn't support NIT"; if so, we should try a bind and use that.
387 */
388static int
389can_be_bound(const char *name _U_)
390{
391	return (1);
392}
393
394static int
395get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)
396{
397	/*
398	 * Nothing we can do.
399	 * XXX - is there a way to find out whether an adapter has
400	 * something plugged into it?
401	 */
402	return (0);
403}
404
405int
406pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
407{
408	return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound,
409	    get_if_flags));
410}
411
412/*
413 * Libpcap version string.
414 */
415const char *
416pcap_lib_version(void)
417{
418	return (PCAP_VERSION_STRING);
419}
420