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#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/dir.h>
34#include <sys/fcntlcom.h>
35#include <sys/file.h>
36#include <sys/ioctl.h>
37#include <sys/socket.h>
38#include <sys/stropts.h>
39
40#include <net/if.h>
41#include <net/nit.h>
42#include <net/nit_if.h>
43#include <net/nit_pf.h>
44#include <net/nit_buf.h>
45
46#include <netinet/in.h>
47#include <netinet/in_systm.h>
48#include <netinet/ip.h>
49#include <netinet/if_ether.h>
50#include <netinet/ip_var.h>
51#include <netinet/udp.h>
52#include <netinet/udp_var.h>
53#include <netinet/tcp.h>
54#include <netinet/tcpip.h>
55
56#include <ctype.h>
57#include <errno.h>
58#include <stdio.h>
59#include <string.h>
60#include <unistd.h>
61
62#include "pcap-int.h"
63
64#ifdef HAVE_OS_PROTO_H
65#include "os-proto.h"
66#endif
67
68/*
69 * The chunk size for NIT.  This is the amount of buffering
70 * done for read calls.
71 */
72#define CHUNKSIZE (2*1024)
73
74/*
75 * The total buffer space used by NIT.
76 */
77#define BUFSPACE (4*CHUNKSIZE)
78
79/* Forwards */
80static int nit_setflags(int, int, int, char *);
81
82/*
83 * Private data for capturing on STREAMS NIT devices.
84 */
85struct pcap_snit {
86	struct pcap_stat stat;
87};
88
89static int
90pcap_stats_snit(pcap_t *p, struct pcap_stat *ps)
91{
92	struct pcap_snit *psn = p->priv;
93
94	/*
95	 * "ps_recv" counts packets handed to the filter, not packets
96	 * that passed the filter.  As filtering is done in userland,
97	 * this does not include packets dropped because we ran out
98	 * of buffer space.
99	 *
100	 * "ps_drop" counts packets dropped inside the "/dev/nit"
101	 * device because of flow control requirements or resource
102	 * exhaustion; it doesn't count packets dropped by the
103	 * interface driver, or packets dropped upstream.  As filtering
104	 * is done in userland, it counts packets regardless of whether
105	 * they would've passed the filter.
106	 *
107	 * These statistics don't include packets not yet read from the
108	 * kernel by libpcap or packets not yet read from libpcap by the
109	 * application.
110	 */
111	*ps = psn->stat;
112	return (0);
113}
114
115static int
116pcap_read_snit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
117{
118	struct pcap_snit *psn = p->priv;
119	register int cc, n;
120	register u_char *bp, *cp, *ep;
121	register struct nit_bufhdr *hdrp;
122	register struct nit_iftime *ntp;
123	register struct nit_iflen *nlp;
124	register struct nit_ifdrops *ndp;
125	register int caplen;
126
127	cc = p->cc;
128	if (cc == 0) {
129		cc = read(p->fd, (char *)p->buffer, p->bufsize);
130		if (cc < 0) {
131			if (errno == EWOULDBLOCK)
132				return (0);
133			pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
134			    errno, "pcap_read");
135			return (-1);
136		}
137		bp = (u_char *)p->buffer;
138	} else
139		bp = p->bp;
140
141	/*
142	 * loop through each snapshot in the chunk
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 (bpf_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
210static int
211pcap_inject_snit(pcap_t *p, const void *buf, size_t 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		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
227		    errno, "send");
228		return (-1);
229	}
230	return (ret);
231}
232
233static int
234nit_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			pcap_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			pcap_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		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
276		    errno, "NIOCSFLAGS");
277		return (-1);
278	}
279	return (0);
280}
281
282static int
283pcap_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		else
338			err = PCAP_ERROR;
339		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
340		    errno, "%s", dev);
341		goto bad;
342	}
343
344	/* arrange to get discrete messages from the STREAM and use NIT_BUF */
345	if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
346		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
347		    errno, "I_SRDOPT");
348		err = PCAP_ERROR;
349		goto bad;
350	}
351	if (ioctl(fd, I_PUSH, "nbuf") < 0) {
352		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
353		    errno, "push nbuf");
354		err = PCAP_ERROR;
355		goto bad;
356	}
357	/* set the chunksize */
358	si.ic_cmd = NIOCSCHUNK;
359	si.ic_timout = INFTIM;
360	si.ic_len = sizeof(chunksize);
361	si.ic_dp = (char *)&chunksize;
362	if (ioctl(fd, I_STR, (char *)&si) < 0) {
363		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
364		    errno, "NIOCSCHUNK");
365		err = PCAP_ERROR;
366		goto bad;
367	}
368
369	/* request the interface */
370	strncpy(ifr.ifr_name, p->opt.device, sizeof(ifr.ifr_name));
371	ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
372	si.ic_cmd = NIOCBIND;
373	si.ic_len = sizeof(ifr);
374	si.ic_dp = (char *)&ifr;
375	if (ioctl(fd, I_STR, (char *)&si) < 0) {
376		/*
377		 * XXX - is there an error that means "no such device"?
378		 * Is there one that means "that device doesn't support
379		 * STREAMS NIT"?
380		 */
381		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
382		    errno, "NIOCBIND: %s", ifr.ifr_name);
383		err = PCAP_ERROR;
384		goto bad;
385	}
386
387	/* set the snapshot length */
388	si.ic_cmd = NIOCSSNAP;
389	si.ic_len = sizeof(p->snapshot);
390	si.ic_dp = (char *)&p->snapshot;
391	if (ioctl(fd, I_STR, (char *)&si) < 0) {
392		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
393		    errno, "NIOCSSNAP");
394		err = PCAP_ERROR;
395		goto bad;
396	}
397	if (nit_setflags(p) < 0) {
398		err = PCAP_ERROR;
399		goto bad;
400	}
401
402	(void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
403	/*
404	 * NIT supports only ethernets.
405	 */
406	p->linktype = DLT_EN10MB;
407
408	p->bufsize = BUFSPACE;
409	p->buffer = malloc(p->bufsize);
410	if (p->buffer == NULL) {
411		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
412		    errno, "malloc");
413		err = PCAP_ERROR;
414		goto bad;
415	}
416
417	/*
418	 * "p->fd" is an FD for a STREAMS device, so "select()" and
419	 * "poll()" should work on it.
420	 */
421	p->selectable_fd = p->fd;
422
423	/*
424	 * This is (presumably) a real Ethernet capture; give it a
425	 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
426	 * that an application can let you choose it, in case you're
427	 * capturing DOCSIS traffic that a Cisco Cable Modem
428	 * Termination System is putting out onto an Ethernet (it
429	 * doesn't put an Ethernet header onto the wire, it puts raw
430	 * DOCSIS frames out on the wire inside the low-level
431	 * Ethernet framing).
432	 */
433	p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
434	/*
435	 * If that fails, just leave the list empty.
436	 */
437	if (p->dlt_list != NULL) {
438		p->dlt_list[0] = DLT_EN10MB;
439		p->dlt_list[1] = DLT_DOCSIS;
440		p->dlt_count = 2;
441	}
442
443	p->read_op = pcap_read_snit;
444	p->inject_op = pcap_inject_snit;
445	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
446	p->setdirection_op = NULL;	/* Not implemented. */
447	p->set_datalink_op = NULL;	/* can't change data link type */
448	p->getnonblock_op = pcap_getnonblock_fd;
449	p->setnonblock_op = pcap_setnonblock_fd;
450	p->stats_op = pcap_stats_snit;
451
452	return (0);
453 bad:
454	pcap_cleanup_live_common(p);
455	return (err);
456}
457
458pcap_t *
459pcap_create_interface(const char *device _U_, char *ebuf)
460{
461	pcap_t *p;
462
463	p = pcap_create_common(ebuf, sizeof (struct pcap_snit));
464	if (p == NULL)
465		return (NULL);
466
467	p->activate_op = pcap_activate_snit;
468	return (p);
469}
470
471/*
472 * XXX - there's probably a NIOCBIND error that means "that device
473 * doesn't support NIT"; if so, we should try an NIOCBIND and use that.
474 */
475static int
476can_be_bound(const char *name _U_)
477{
478	return (1);
479}
480
481static int
482get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)
483{
484	/*
485	 * Nothing we can do.
486	 * XXX - is there a way to find out whether an adapter has
487	 * something plugged into it?
488	 */
489	return (0);
490}
491
492int
493pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
494{
495	return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound,
496	    get_if_flags));
497}
498
499/*
500 * Libpcap version string.
501 */
502const char *
503pcap_lib_version(void)
504{
505	return (PCAP_VERSION_STRING);
506}
507