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 <errno.h>
57#include <stdio.h>
58#include <string.h>
59#include <unistd.h>
60
61#include "pcap-int.h"
62
63#ifdef HAVE_OS_PROTO_H
64#include "os-proto.h"
65#endif
66
67/*
68 * The chunk size for NIT.  This is the amount of buffering
69 * done for read calls.
70 */
71#define CHUNKSIZE (2*1024)
72
73/*
74 * The total buffer space used by NIT.
75 */
76#define BUFSPACE (4*CHUNKSIZE)
77
78/* Forwards */
79static int nit_setflags(int, int, int, char *);
80
81/*
82 * Private data for capturing on STREAMS NIT devices.
83 */
84struct pcap_snit {
85	struct pcap_stat stat;
86};
87
88static int
89pcap_stats_snit(pcap_t *p, struct pcap_stat *ps)
90{
91	struct pcap_snit *psn = p->priv;
92
93	/*
94	 * "ps_recv" counts packets handed to the filter, not packets
95	 * that passed the filter.  As filtering is done in userland,
96	 * this does not include packets dropped because we ran out
97	 * of buffer space.
98	 *
99	 * "ps_drop" counts packets dropped inside the "/dev/nit"
100	 * device because of flow control requirements or resource
101	 * exhaustion; it doesn't count packets dropped by the
102	 * interface driver, or packets dropped upstream.  As filtering
103	 * is done in userland, it counts packets regardless of whether
104	 * they would've passed the filter.
105	 *
106	 * These statistics don't include packets not yet read from the
107	 * kernel by libpcap or packets not yet read from libpcap by the
108	 * application.
109	 */
110	*ps = psn->stat;
111	return (0);
112}
113
114static int
115pcap_read_snit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
116{
117	struct pcap_snit *psn = p->priv;
118	register int cc, n;
119	register u_char *bp, *cp, *ep;
120	register struct nit_bufhdr *hdrp;
121	register struct nit_iftime *ntp;
122	register struct nit_iflen *nlp;
123	register struct nit_ifdrops *ndp;
124	register int caplen;
125
126	cc = p->cc;
127	if (cc == 0) {
128		cc = read(p->fd, (char *)p->buffer, p->bufsize);
129		if (cc < 0) {
130			if (errno == EWOULDBLOCK)
131				return (0);
132			pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
133			    errno, "pcap_read");
134			return (-1);
135		}
136		bp = (u_char *)p->buffer;
137	} else
138		bp = p->bp;
139
140	/*
141	 * loop through each snapshot in the chunk
142	 *
143	 * This assumes that a single buffer of packets will have
144	 * <= INT_MAX packets, so the packet count doesn't overflow.
145	 */
146	n = 0;
147	ep = bp + cc;
148	while (bp < ep) {
149		/*
150		 * Has "pcap_breakloop()" been called?
151		 * If so, return immediately - if we haven't read any
152		 * packets, clear the flag and return -2 to indicate
153		 * that we were told to break out of the loop, otherwise
154		 * leave the flag set, so that the *next* call will break
155		 * out of the loop without having read any packets, and
156		 * return the number of packets we've processed so far.
157		 */
158		if (p->break_loop) {
159			if (n == 0) {
160				p->break_loop = 0;
161				return (-2);
162			} else {
163				p->bp = bp;
164				p->cc = ep - bp;
165				return (n);
166			}
167		}
168
169		++psn->stat.ps_recv;
170		cp = bp;
171
172		/* get past NIT buffer  */
173		hdrp = (struct nit_bufhdr *)cp;
174		cp += sizeof(*hdrp);
175
176		/* get past NIT timer   */
177		ntp = (struct nit_iftime *)cp;
178		cp += sizeof(*ntp);
179
180		ndp = (struct nit_ifdrops *)cp;
181		psn->stat.ps_drop = ndp->nh_drops;
182		cp += sizeof *ndp;
183
184		/* get past packet len  */
185		nlp = (struct nit_iflen *)cp;
186		cp += sizeof(*nlp);
187
188		/* next snapshot        */
189		bp += hdrp->nhb_totlen;
190
191		caplen = nlp->nh_pktlen;
192		if (caplen > p->snapshot)
193			caplen = p->snapshot;
194
195		if (pcap_filter(p->fcode.bf_insns, cp, nlp->nh_pktlen, caplen)) {
196			struct pcap_pkthdr h;
197			h.ts = ntp->nh_timestamp;
198			h.len = nlp->nh_pktlen;
199			h.caplen = caplen;
200			(*callback)(user, &h, cp);
201			if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) {
202				p->cc = ep - bp;
203				p->bp = bp;
204				return (n);
205			}
206		}
207	}
208	p->cc = 0;
209	return (n);
210}
211
212static int
213pcap_inject_snit(pcap_t *p, const void *buf, int size)
214{
215	struct strbuf ctl, data;
216
217	/*
218	 * XXX - can we just do
219	 *
220	ret = write(pd->f, buf, size);
221	 */
222	ctl.len = sizeof(*sa);	/* XXX - what was this? */
223	ctl.buf = (char *)sa;
224	data.buf = buf;
225	data.len = size;
226	ret = putmsg(p->fd, &ctl, &data);
227	if (ret == -1) {
228		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
229		    errno, "send");
230		return (-1);
231	}
232	return (ret);
233}
234
235static int
236nit_setflags(pcap_t *p)
237{
238	bpf_u_int32 flags;
239	struct strioctl si;
240	u_int zero = 0;
241	struct timeval timeout;
242
243	if (p->opt.immediate) {
244		/*
245		 * Set the chunk size to zero, so that chunks get sent
246		 * up immediately.
247		 */
248		si.ic_cmd = NIOCSCHUNK;
249		si.ic_len = sizeof(zero);
250		si.ic_dp = (char *)&zero;
251		if (ioctl(p->fd, I_STR, (char *)&si) < 0) {
252			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
253			    errno, "NIOCSCHUNK");
254			return (-1);
255		}
256	}
257	si.ic_timout = INFTIM;
258	if (p->opt.timeout != 0) {
259		timeout.tv_sec = p->opt.timeout / 1000;
260		timeout.tv_usec = (p->opt.timeout * 1000) % 1000000;
261		si.ic_cmd = NIOCSTIME;
262		si.ic_len = sizeof(timeout);
263		si.ic_dp = (char *)&timeout;
264		if (ioctl(p->fd, I_STR, (char *)&si) < 0) {
265			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
266			    errno, "NIOCSTIME");
267			return (-1);
268		}
269	}
270	flags = NI_TIMESTAMP | NI_LEN | NI_DROPS;
271	if (p->opt.promisc)
272		flags |= NI_PROMISC;
273	si.ic_cmd = NIOCSFLAGS;
274	si.ic_len = sizeof(flags);
275	si.ic_dp = (char *)&flags;
276	if (ioctl(p->fd, I_STR, (char *)&si) < 0) {
277		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
278		    errno, "NIOCSFLAGS");
279		return (-1);
280	}
281	return (0);
282}
283
284static int
285pcap_activate_snit(pcap_t *p)
286{
287	struct strioctl si;		/* struct for ioctl() */
288	struct ifreq ifr;		/* interface request struct */
289	int chunksize = CHUNKSIZE;
290	int fd;
291	static const char dev[] = "/dev/nit";
292	int err;
293
294	if (p->opt.rfmon) {
295		/*
296		 * No monitor mode on SunOS 4.x (no Wi-Fi devices on
297		 * hardware supported by SunOS 4.x).
298		 */
299		return (PCAP_ERROR_RFMON_NOTSUP);
300	}
301
302	/*
303	 * Turn a negative snapshot value (invalid), a snapshot value of
304	 * 0 (unspecified), or a value bigger than the normal maximum
305	 * value, into the maximum allowed value.
306	 *
307	 * If some application really *needs* a bigger snapshot
308	 * length, we should just increase MAXIMUM_SNAPLEN.
309	 */
310	if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
311		p->snapshot = MAXIMUM_SNAPLEN;
312
313	if (p->snapshot < 96)
314		/*
315		 * NIT requires a snapshot length of at least 96.
316		 */
317		p->snapshot = 96;
318
319	/*
320	 * Initially try a read/write open (to allow the inject
321	 * method to work).  If that fails due to permission
322	 * issues, fall back to read-only.  This allows a
323	 * non-root user to be granted specific access to pcap
324	 * capabilities via file permissions.
325	 *
326	 * XXX - we should have an API that has a flag that
327	 * controls whether to open read-only or read-write,
328	 * so that denial of permission to send (or inability
329	 * to send, if sending packets isn't supported on
330	 * the device in question) can be indicated at open
331	 * time.
332	 */
333	p->fd = fd = open(dev, O_RDWR);
334	if (fd < 0 && errno == EACCES)
335		p->fd = fd = open(dev, O_RDONLY);
336	if (fd < 0) {
337		if (errno == EACCES) {
338			err = PCAP_ERROR_PERM_DENIED;
339			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
340			    "Attempt to open %s failed with EACCES - root privileges may be required",
341			    dev);
342		} else {
343			err = PCAP_ERROR;
344			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
345			    errno, "%s", dev);
346		}
347		goto bad;
348	}
349
350	/* arrange to get discrete messages from the STREAM and use NIT_BUF */
351	if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
352		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
353		    errno, "I_SRDOPT");
354		err = PCAP_ERROR;
355		goto bad;
356	}
357	if (ioctl(fd, I_PUSH, "nbuf") < 0) {
358		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
359		    errno, "push nbuf");
360		err = PCAP_ERROR;
361		goto bad;
362	}
363	/* set the chunksize */
364	si.ic_cmd = NIOCSCHUNK;
365	si.ic_timout = INFTIM;
366	si.ic_len = sizeof(chunksize);
367	si.ic_dp = (char *)&chunksize;
368	if (ioctl(fd, I_STR, (char *)&si) < 0) {
369		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
370		    errno, "NIOCSCHUNK");
371		err = PCAP_ERROR;
372		goto bad;
373	}
374
375	/* request the interface */
376	strncpy(ifr.ifr_name, p->opt.device, sizeof(ifr.ifr_name));
377	ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
378	si.ic_cmd = NIOCBIND;
379	si.ic_len = sizeof(ifr);
380	si.ic_dp = (char *)&ifr;
381	if (ioctl(fd, I_STR, (char *)&si) < 0) {
382		/*
383		 * XXX - is there an error that means "no such device"?
384		 * Is there one that means "that device doesn't support
385		 * STREAMS NIT"?
386		 */
387		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
388		    errno, "NIOCBIND: %s", ifr.ifr_name);
389		err = PCAP_ERROR;
390		goto bad;
391	}
392
393	/* set the snapshot length */
394	si.ic_cmd = NIOCSSNAP;
395	si.ic_len = sizeof(p->snapshot);
396	si.ic_dp = (char *)&p->snapshot;
397	if (ioctl(fd, I_STR, (char *)&si) < 0) {
398		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
399		    errno, "NIOCSSNAP");
400		err = PCAP_ERROR;
401		goto bad;
402	}
403	if (nit_setflags(p) < 0) {
404		err = PCAP_ERROR;
405		goto bad;
406	}
407
408	(void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
409	/*
410	 * NIT supports only ethernets.
411	 */
412	p->linktype = DLT_EN10MB;
413
414	p->bufsize = BUFSPACE;
415	p->buffer = malloc(p->bufsize);
416	if (p->buffer == NULL) {
417		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
418		    errno, "malloc");
419		err = PCAP_ERROR;
420		goto bad;
421	}
422
423	/*
424	 * "p->fd" is an FD for a STREAMS device, so "select()" and
425	 * "poll()" should work on it.
426	 */
427	p->selectable_fd = p->fd;
428
429	/*
430	 * This is (presumably) a real Ethernet capture; give it a
431	 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
432	 * that an application can let you choose it, in case you're
433	 * capturing DOCSIS traffic that a Cisco Cable Modem
434	 * Termination System is putting out onto an Ethernet (it
435	 * doesn't put an Ethernet header onto the wire, it puts raw
436	 * DOCSIS frames out on the wire inside the low-level
437	 * Ethernet framing).
438	 */
439	p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
440	/*
441	 * If that fails, just leave the list empty.
442	 */
443	if (p->dlt_list != NULL) {
444		p->dlt_list[0] = DLT_EN10MB;
445		p->dlt_list[1] = DLT_DOCSIS;
446		p->dlt_count = 2;
447	}
448
449	p->read_op = pcap_read_snit;
450	p->inject_op = pcap_inject_snit;
451	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
452	p->setdirection_op = NULL;	/* Not implemented. */
453	p->set_datalink_op = NULL;	/* can't change data link type */
454	p->getnonblock_op = pcap_getnonblock_fd;
455	p->setnonblock_op = pcap_setnonblock_fd;
456	p->stats_op = pcap_stats_snit;
457
458	return (0);
459 bad:
460	pcap_cleanup_live_common(p);
461	return (err);
462}
463
464pcap_t *
465pcap_create_interface(const char *device _U_, char *ebuf)
466{
467	pcap_t *p;
468
469	p = PCAP_CREATE_COMMON(ebuf, struct pcap_snit);
470	if (p == NULL)
471		return (NULL);
472
473	p->activate_op = pcap_activate_snit;
474	return (p);
475}
476
477/*
478 * XXX - there's probably a NIOCBIND error that means "that device
479 * doesn't support NIT"; if so, we should try an NIOCBIND and use that.
480 */
481static int
482can_be_bound(const char *name _U_)
483{
484	return (1);
485}
486
487static int
488get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)
489{
490	/*
491	 * Nothing we can do.
492	 * XXX - is there a way to find out whether an adapter has
493	 * something plugged into it?
494	 */
495	return (0);
496}
497
498int
499pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
500{
501	return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound,
502	    get_if_flags));
503}
504
505/*
506 * Libpcap version string.
507 */
508const char *
509pcap_lib_version(void)
510{
511	return (PCAP_VERSION_STRING);
512}
513