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
22 static const char rcsid[] _U_ =
23 "@(#) $Header: /tcpdump/master/libpcap/pcap-nit.c,v 1.57.2.1 2005/05/03 18:54:37 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 */
72 static int nit_setflags(int, int, int, char *);
73
74 static int
pcap_stats_nit(pcap_t * p,struct pcap_stat * ps)75 pcap_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
98 static int
pcap_read_nit(pcap_t * p,int cnt,pcap_handler callback,u_char * user)99 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
100 {
101 register int cc, n;
102 register struct bpf_insn *fcode = p->fcode.bf_insns;
103 register u_char *bp, *cp, *ep;
104 register struct nit_hdr *nh;
105 register int caplen;
106
107 cc = p->cc;
108 if (cc == 0) {
109 cc = read(p->fd, (char *)p->buffer, p->bufsize);
110 if (cc < 0) {
111 if (errno == EWOULDBLOCK)
112 return (0);
113 snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
114 pcap_strerror(errno));
115 return (-1);
116 }
117 bp = p->buffer;
118 } else
119 bp = p->bp;
120
121 /*
122 * Loop through each packet. The increment expression
123 * rounds up to the next int boundary past the end of
124 * the previous packet.
125 */
126 n = 0;
127 ep = bp + cc;
128 while (bp < ep) {
129 /*
130 * Has "pcap_breakloop()" been called?
131 * If so, return immediately - if we haven't read any
132 * packets, clear the flag and return -2 to indicate
133 * that we were told to break out of the loop, otherwise
134 * leave the flag set, so that the *next* call will break
135 * out of the loop without having read any packets, and
136 * return the number of packets we've processed so far.
137 */
138 if (p->break_loop) {
139 if (n == 0) {
140 p->break_loop = 0;
141 return (-2);
142 } else {
143 p->cc = ep - bp;
144 p->bp = bp;
145 return (n);
146 }
147 }
148
149 nh = (struct nit_hdr *)bp;
150 cp = bp + sizeof(*nh);
151
152 switch (nh->nh_state) {
153
154 case NIT_CATCH:
155 break;
156
157 case NIT_NOMBUF:
158 case NIT_NOCLUSTER:
159 case NIT_NOSPACE:
160 p->md.stat.ps_drop = nh->nh_dropped;
161 continue;
162
163 case NIT_SEQNO:
164 continue;
165
166 default:
167 snprintf(p->errbuf, sizeof(p->errbuf),
168 "bad nit state %d", nh->nh_state);
169 return (-1);
170 }
171 ++p->md.stat.ps_recv;
172 bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
173 sizeof(int) - 1) & ~(sizeof(int) - 1));
174
175 caplen = nh->nh_wirelen;
176 if (caplen > p->snapshot)
177 caplen = p->snapshot;
178 if (bpf_filter(fcode, cp, nh->nh_wirelen, caplen)) {
179 struct pcap_pkthdr h;
180 h.ts = nh->nh_timestamp;
181 h.len = nh->nh_wirelen;
182 h.caplen = caplen;
183 (*callback)(user, &h, cp);
184 if (++n >= cnt && cnt >= 0) {
185 p->cc = ep - bp;
186 p->bp = bp;
187 return (n);
188 }
189 }
190 }
191 p->cc = 0;
192 return (n);
193 }
194
195 static int
pcap_inject_nit(pcap_t * p,const void * buf,size_t size)196 pcap_inject_nit(pcap_t *p, const void *buf, size_t size)
197 {
198 struct sockaddr sa;
199 int ret;
200
201 memset(&sa, 0, sizeof(sa));
202 strncpy(sa.sa_data, device, sizeof(sa.sa_data));
203 ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa));
204 if (ret == -1) {
205 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
206 pcap_strerror(errno));
207 return (-1);
208 }
209 return (ret);
210 }
211
212 static int
nit_setflags(int fd,int promisc,int to_ms,char * ebuf)213 nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
214 {
215 struct nit_ioc nioc;
216
217 memset(&nioc, 0, sizeof(nioc));
218 nioc.nioc_bufspace = BUFSPACE;
219 nioc.nioc_chunksize = CHUNKSIZE;
220 nioc.nioc_typetomatch = NT_ALLTYPES;
221 nioc.nioc_snaplen = p->snapshot;
222 nioc.nioc_bufalign = sizeof(int);
223 nioc.nioc_bufoffset = 0;
224
225 if (to_ms != 0) {
226 nioc.nioc_flags |= NF_TIMEOUT;
227 nioc.nioc_timeout.tv_sec = to_ms / 1000;
228 nioc.nioc_timeout.tv_usec = (to_ms * 1000) % 1000000;
229 }
230 if (promisc)
231 nioc.nioc_flags |= NF_PROMISC;
232
233 if (ioctl(fd, SIOCSNIT, &nioc) < 0) {
234 snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s",
235 pcap_strerror(errno));
236 return (-1);
237 }
238 return (0);
239 }
240
241 static void
pcap_close_nit(pcap_t * p)242 pcap_close_nit(pcap_t *p)
243 {
244 pcap_close_common(p);
245 if (p->device != NULL)
246 free(p->device);
247 }
248
249 pcap_t *
pcap_open_live(const char * device,int snaplen,int promisc,int to_ms,char * ebuf)250 pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
251 char *ebuf)
252 {
253 int fd;
254 struct sockaddr_nit snit;
255 register pcap_t *p;
256
257 p = (pcap_t *)malloc(sizeof(*p));
258 if (p == NULL) {
259 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
260 return (NULL);
261 }
262
263 if (snaplen < 96)
264 /*
265 * NIT requires a snapshot length of at least 96.
266 */
267 snaplen = 96;
268
269 memset(p, 0, sizeof(*p));
270 p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
271 if (fd < 0) {
272 snprintf(ebuf, PCAP_ERRBUF_SIZE,
273 "socket: %s", pcap_strerror(errno));
274 goto bad;
275 }
276 snit.snit_family = AF_NIT;
277 (void)strncpy(snit.snit_ifname, device, NITIFSIZ);
278
279 if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
280 snprintf(ebuf, PCAP_ERRBUF_SIZE,
281 "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno));
282 goto bad;
283 }
284 p->snapshot = snaplen;
285 nit_setflags(p->fd, promisc, to_ms, ebuf);
286
287 /*
288 * NIT supports only ethernets.
289 */
290 p->linktype = DLT_EN10MB;
291
292 p->bufsize = BUFSPACE;
293 p->buffer = (u_char *)malloc(p->bufsize);
294 if (p->buffer == NULL) {
295 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
296 goto bad;
297 }
298
299 /*
300 * We need the device name in order to send packets.
301 */
302 p->device = strdup(device);
303 if (p->device == NULL) {
304 strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
305 free(p->buffer);
306 goto bad;
307 }
308
309 /*
310 * "p->fd" is a socket, so "select()" should work on it.
311 */
312 p->selectable_fd = p->fd;
313
314 /*
315 * This is (presumably) a real Ethernet capture; give it a
316 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
317 * that an application can let you choose it, in case you're
318 * capturing DOCSIS traffic that a Cisco Cable Modem
319 * Termination System is putting out onto an Ethernet (it
320 * doesn't put an Ethernet header onto the wire, it puts raw
321 * DOCSIS frames out on the wire inside the low-level
322 * Ethernet framing).
323 */
324 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
325 /*
326 * If that fails, just leave the list empty.
327 */
328 if (p->dlt_list != NULL) {
329 p->dlt_list[0] = DLT_EN10MB;
330 p->dlt_list[1] = DLT_DOCSIS;
331 p->dlt_count = 2;
332 }
333
334 p->read_op = pcap_read_nit;
335 p->inject_op = pcap_inject_nit;
336 p->setfilter_op = install_bpf_program; /* no kernel filtering */
337 p->setdirection_op = NULL; /* Not implemented. */
338 p->set_datalink_op = NULL; /* can't change data link type */
339 p->getnonblock_op = pcap_getnonblock_fd;
340 p->setnonblock_op = pcap_setnonblock_fd;
341 p->stats_op = pcap_stats_nit;
342 p->close_op = pcap_close_nit;
343
344 return (p);
345 bad:
346 if (fd >= 0)
347 close(fd);
348 free(p);
349 return (NULL);
350 }
351
352 int
pcap_platform_finddevs(pcap_if_t ** alldevsp,char * errbuf)353 pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
354 {
355 return (0);
356 }
357