2 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996
3 * The Regents of the University of California. All rights reserved.
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
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.
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.
27 static const char rcsid[] _U_ =
28 "@(#) $Header: /tcpdump/master/libpcap/pcap-snit.c,v 1.66.2.3 2003/11/21 10:20:48 guy Exp $ (LBL)";
35 #include <sys/types.h>
37 #include <sys/timeb.h>
39 #include <sys/fcntlcom.h>
41 #include <sys/ioctl.h>
42 #include <sys/socket.h>
43 #include <sys/stropts.h>
47 #include <net/nit_if.h>
48 #include <net/nit_pf.h>
49 #include <net/nit_buf.h>
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>
69 #ifdef HAVE_OS_PROTO_H
74 * The chunk size for NIT. This is the amount of buffering
75 * done for read calls.
77 #define CHUNKSIZE (2*1024)
80 * The total buffer space used by NIT.
82 #define BUFSPACE (4*CHUNKSIZE)
85 static int nit_setflags(int, int, int, char *);
88 pcap_stats_snit(pcap_t *p, struct pcap_stat *ps)
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
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.
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
113 pcap_read_snit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
116 register struct bpf_insn *fcode = p->fcode.bf_insns;
117 register u_char *bp, *cp, *ep;
118 register struct nit_bufhdr *hdrp;
119 register struct nit_iftime *ntp;
120 register struct nit_iflen *nlp;
121 register struct nit_ifdrops *ndp;
126 cc = read(p->fd, (char *)p->buffer, p->bufsize);
128 if (errno == EWOULDBLOCK)
130 snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
131 pcap_strerror(errno));
139 * loop through each snapshot in the chunk
145 * Has "pcap_breakloop()" been called?
146 * If so, return immediately - if we haven't read any
147 * packets, clear the flag and return -2 to indicate
148 * that we were told to break out of the loop, otherwise
149 * leave the flag set, so that the *next* call will break
150 * out of the loop without having read any packets, and
151 * return the number of packets we've processed so far.
164 ++p->md.stat.ps_recv;
167 /* get past NIT buffer */
168 hdrp = (struct nit_bufhdr *)cp;
171 /* get past NIT timer */
172 ntp = (struct nit_iftime *)cp;
175 ndp = (struct nit_ifdrops *)cp;
176 p->md.stat.ps_drop = ndp->nh_drops;
179 /* get past packet len */
180 nlp = (struct nit_iflen *)cp;
184 bp += hdrp->nhb_totlen;
186 caplen = nlp->nh_pktlen;
187 if (caplen > p->snapshot)
188 caplen = p->snapshot;
190 if (bpf_filter(fcode, cp, nlp->nh_pktlen, caplen)) {
191 struct pcap_pkthdr h;
192 h.ts = ntp->nh_timestamp;
193 h.len = nlp->nh_pktlen;
195 (*callback)(user, &h, cp);
196 if (++n >= cnt && cnt >= 0) {
208 nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
212 struct timeval timeout;
214 si.ic_timout = INFTIM;
216 timeout.tv_sec = to_ms / 1000;
217 timeout.tv_usec = (to_ms * 1000) % 1000000;
218 si.ic_cmd = NIOCSTIME;
219 si.ic_len = sizeof(timeout);
220 si.ic_dp = (char *)&timeout;
221 if (ioctl(fd, I_STR, (char *)&si) < 0) {
222 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSTIME: %s",
223 pcap_strerror(errno));
227 flags = NI_TIMESTAMP | NI_LEN | NI_DROPS;
230 si.ic_cmd = NIOCSFLAGS;
231 si.ic_len = sizeof(flags);
232 si.ic_dp = (char *)&flags;
233 if (ioctl(fd, I_STR, (char *)&si) < 0) {
234 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSFLAGS: %s",
235 pcap_strerror(errno));
242 pcap_close_snit(pcap_t *p)
244 if (p->buffer != NULL)
251 pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
254 struct strioctl si; /* struct for ioctl() */
255 struct ifreq ifr; /* interface request struct */
256 int chunksize = CHUNKSIZE;
258 static char dev[] = "/dev/nit";
261 p = (pcap_t *)malloc(sizeof(*p));
263 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
269 * NIT requires a snapshot length of at least 96.
273 memset(p, 0, sizeof(*p));
274 p->fd = fd = open(dev, O_RDONLY);
276 snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s", dev,
277 pcap_strerror(errno));
281 /* arrange to get discrete messages from the STREAM and use NIT_BUF */
282 if (ioctl(fd, I_SRDOPT, (char *)RMSGD) < 0) {
283 snprintf(ebuf, PCAP_ERRBUF_SIZE, "I_SRDOPT: %s",
284 pcap_strerror(errno));
287 if (ioctl(fd, I_PUSH, "nbuf") < 0) {
288 snprintf(ebuf, PCAP_ERRBUF_SIZE, "push nbuf: %s",
289 pcap_strerror(errno));
292 /* set the chunksize */
293 si.ic_cmd = NIOCSCHUNK;
294 si.ic_timout = INFTIM;
295 si.ic_len = sizeof(chunksize);
296 si.ic_dp = (char *)&chunksize;
297 if (ioctl(fd, I_STR, (char *)&si) < 0) {
298 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSCHUNK: %s",
299 pcap_strerror(errno));
303 /* request the interface */
304 strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
305 ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
306 si.ic_cmd = NIOCBIND;
307 si.ic_len = sizeof(ifr);
308 si.ic_dp = (char *)𝔦
309 if (ioctl(fd, I_STR, (char *)&si) < 0) {
310 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCBIND: %s: %s",
311 ifr.ifr_name, pcap_strerror(errno));
315 /* set the snapshot length */
316 si.ic_cmd = NIOCSSNAP;
317 si.ic_len = sizeof(snaplen);
318 si.ic_dp = (char *)&snaplen;
319 if (ioctl(fd, I_STR, (char *)&si) < 0) {
320 snprintf(ebuf, PCAP_ERRBUF_SIZE, "NIOCSSNAP: %s",
321 pcap_strerror(errno));
324 p->snapshot = snaplen;
325 if (nit_setflags(p->fd, promisc, to_ms, ebuf) < 0)
328 (void)ioctl(fd, I_FLUSH, (char *)FLUSHR);
330 * NIT supports only ethernets.
332 p->linktype = DLT_EN10MB;
334 p->bufsize = BUFSPACE;
335 p->buffer = (u_char *)malloc(p->bufsize);
336 if (p->buffer == NULL) {
337 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
342 * "p->fd" is an FD for a STREAMS device, so "select()" and
343 * "poll()" should work on it.
345 p->selectable_fd = p->fd;
347 p->read_op = pcap_read_snit;
348 p->setfilter_op = install_bpf_program; /* no kernel filtering */
349 p->set_datalink_op = NULL; /* can't change data link type */
350 p->getnonblock_op = pcap_getnonblock_fd;
351 p->setnonblock_op = pcap_setnonblock_fd;
352 p->stats_op = pcap_stats_snit;
353 p->close_op = pcap_close_snit;
364 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)