1 /*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
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 #include "varattrs.h"
23
24 #ifndef lint
25 static const char copyright[] _U_ =
26 "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
27 The Regents of the University of California. All rights reserved.\n";
28 #endif
29
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <stdarg.h>
34 #include <limits.h>
35 #ifdef _WIN32
36 #include <winsock2.h>
37 #include <windows.h>
38
39 #define THREAD_HANDLE HANDLE
40 #define THREAD_FUNC_ARG_TYPE LPVOID
41 #define THREAD_FUNC_RETURN_TYPE DWORD __stdcall
42
43 #include "getopt.h"
44 #else
45 #include <pthread.h>
46 #include <signal.h>
47 #include <unistd.h>
48
49 #define THREAD_HANDLE pthread_t
50 #define THREAD_FUNC_ARG_TYPE void *
51 #define THREAD_FUNC_RETURN_TYPE void *
52 #endif
53 #include <errno.h>
54 #include <sys/types.h>
55
56 #include <pcap.h>
57
58 #include "pcap/funcattrs.h"
59
60 #ifdef _WIN32
61 #include "portability.h"
62 #endif
63
64 static char *program_name;
65
66 /* Forwards */
67 static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
68 static void PCAP_NORETURN usage(void);
69 static void PCAP_NORETURN error(const char *, ...) PCAP_PRINTFLIKE(1, 2);
70 static void warning(const char *, ...) PCAP_PRINTFLIKE(1, 2);
71 static char *copy_argv(char **);
72
73 static pcap_t *pd;
74
75 #ifdef _WIN32
76 /*
77 * Generate a string for a Win32-specific error (i.e. an error generated when
78 * calling a Win32 API).
79 * For errors occurred during standard C calls, we still use pcap_strerror()
80 */
81 #define ERRBUF_SIZE 1024
82 static const char *
win32_strerror(DWORD error)83 win32_strerror(DWORD error)
84 {
85 static char errbuf[ERRBUF_SIZE+1];
86 size_t errlen;
87
88 FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, 0, errbuf,
89 ERRBUF_SIZE, NULL);
90
91 /*
92 * "FormatMessage()" "helpfully" sticks CR/LF at the end of the
93 * message. Get rid of it.
94 */
95 errlen = strlen(errbuf);
96 if (errlen >= 2) {
97 errbuf[errlen - 1] = '\0';
98 errbuf[errlen - 2] = '\0';
99 errlen -= 2;
100 }
101 return errbuf;
102 }
103 #else
104 static void
catch_sigusr1(int sig _U_)105 catch_sigusr1(int sig _U_)
106 {
107 printf("Got SIGUSR1\n");
108 }
109 #endif
110
111 static void
sleep_secs(int secs)112 sleep_secs(int secs)
113 {
114 #ifdef _WIN32
115 Sleep(secs*1000);
116 #else
117 unsigned secs_remaining;
118
119 if (secs <= 0)
120 return;
121 secs_remaining = secs;
122 while (secs_remaining != 0)
123 secs_remaining = sleep(secs_remaining);
124 #endif
125 }
126
127 static THREAD_FUNC_RETURN_TYPE
capture_thread_func(THREAD_FUNC_ARG_TYPE arg)128 capture_thread_func(THREAD_FUNC_ARG_TYPE arg)
129 {
130 char *device = arg;
131 int packet_count;
132 int status;
133 #ifndef _WIN32
134 struct sigaction action;
135 sigset_t mask;
136 #endif
137
138 #ifndef _WIN32
139 sigemptyset(&mask);
140 action.sa_handler = catch_sigusr1;
141 action.sa_mask = mask;
142 action.sa_flags = 0;
143 if (sigaction(SIGUSR1, &action, NULL) == -1)
144 error("Can't catch SIGUSR1: %s", strerror(errno));
145 #endif
146
147 printf("Listening on %s\n", device);
148 for (;;) {
149 packet_count = 0;
150 status = pcap_dispatch(pd, -1, countme,
151 (u_char *)&packet_count);
152 if (status < 0)
153 break;
154 if (status != 0) {
155 printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
156 status, packet_count);
157 } else
158 printf("No packets seen by pcap_dispatch\n");
159 }
160 if (status == PCAP_ERROR_BREAK) {
161 /*
162 * We got interrupted, so perhaps we didn't
163 * manage to finish a line we were printing.
164 * Print an extra newline, just in case.
165 */
166 putchar('\n');
167 printf("Loop got broken\n");
168 }
169 (void)fflush(stdout);
170 if (status == PCAP_ERROR) {
171 /*
172 * Error. Report it.
173 */
174 (void)fprintf(stderr, "%s: pcap_dispatch: %s\n",
175 program_name, pcap_geterr(pd));
176 }
177 return 0;
178 }
179
180 int
main(int argc,char ** argv)181 main(int argc, char **argv)
182 {
183 register int op;
184 register char *cp, *cmdbuf, *device;
185 int do_wakeup = 1;
186 pcap_if_t *devlist;
187 bpf_u_int32 localnet, netmask;
188 struct bpf_program fcode;
189 char ebuf[PCAP_ERRBUF_SIZE];
190 int status;
191 THREAD_HANDLE capture_thread;
192 #ifndef _WIN32
193 void *retval;
194 #endif
195
196 device = NULL;
197 if ((cp = strrchr(argv[0], '/')) != NULL)
198 program_name = cp + 1;
199 else
200 program_name = argv[0];
201
202 opterr = 0;
203 while ((op = getopt(argc, argv, "i:n")) != -1) {
204 switch (op) {
205
206 case 'i':
207 device = optarg;
208 break;
209
210 case 'n':
211 do_wakeup = 0;
212 break;
213
214 default:
215 usage();
216 /* NOTREACHED */
217 }
218 }
219
220 if (device == NULL) {
221 if (pcap_findalldevs(&devlist, ebuf) == -1)
222 error("%s", ebuf);
223 if (devlist == NULL)
224 error("no interfaces available for capture");
225 device = strdup(devlist->name);
226 pcap_freealldevs(devlist);
227 }
228 *ebuf = '\0';
229 pd = pcap_create(device, ebuf);
230 if (pd == NULL)
231 error("%s", ebuf);
232 status = pcap_set_snaplen(pd, 65535);
233 if (status != 0)
234 error("%s: pcap_set_snaplen failed: %s",
235 device, pcap_statustostr(status));
236 status = pcap_set_timeout(pd, 5*60*1000);
237 if (status != 0)
238 error("%s: pcap_set_timeout failed: %s",
239 device, pcap_statustostr(status));
240 status = pcap_activate(pd);
241 if (status < 0) {
242 /*
243 * pcap_activate() failed.
244 */
245 error("%s: %s\n(%s)", device,
246 pcap_statustostr(status), pcap_geterr(pd));
247 } else if (status > 0) {
248 /*
249 * pcap_activate() succeeded, but it's warning us
250 * of a problem it had.
251 */
252 warning("%s: %s\n(%s)", device,
253 pcap_statustostr(status), pcap_geterr(pd));
254 }
255 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
256 localnet = 0;
257 netmask = 0;
258 warning("%s", ebuf);
259 }
260 cmdbuf = copy_argv(&argv[optind]);
261
262 if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
263 error("%s", pcap_geterr(pd));
264
265 if (pcap_setfilter(pd, &fcode) < 0)
266 error("%s", pcap_geterr(pd));
267
268 #ifdef _WIN32
269 capture_thread = CreateThread(NULL, 0, capture_thread_func, device,
270 0, NULL);
271 if (capture_thread == NULL)
272 error("Can't create capture thread: %s",
273 win32_strerror(GetLastError()));
274 #else
275 status = pthread_create(&capture_thread, NULL, capture_thread_func,
276 device);
277 if (status != 0)
278 error("Can't create capture thread: %s", strerror(status));
279 #endif
280 sleep_secs(60);
281 printf("Doing pcap_breakloop()\n");
282 pcap_breakloop(pd);
283 if (do_wakeup) {
284 /*
285 * Force a wakeup in the capture thread.
286 *
287 * On some platforms, with some devices,, pcap_breakloop()
288 * can't do that itself. On Windows, poke the device's
289 * event handle; on UN*X, send a SIGUSR1 to the thread.
290 */
291 #ifdef _WIN32
292 printf("Setting event\n");
293 if (!SetEvent(pcap_getevent(pd)))
294 error("Can't set event for pcap_t: %s",
295 win32_strerror(GetLastError()));
296 #else
297 printf("Sending SIGUSR1\n");
298 status = pthread_kill(capture_thread, SIGUSR1);
299 if (status != 0)
300 warning("Can't interrupt capture thread: %s",
301 strerror(status));
302 #endif
303 }
304
305 /*
306 * Now wait for the capture thread to terminate.
307 */
308 #ifdef _WIN32
309 if (WaitForSingleObject(capture_thread, INFINITE) == WAIT_FAILED)
310 error("Wait for thread termination failed: %s",
311 win32_strerror(GetLastError()));
312 CloseHandle(capture_thread);
313 #else
314 status = pthread_join(capture_thread, &retval);
315 if (status != 0)
316 error("Wait for thread termination failed: %s",
317 strerror(status));
318 #endif
319
320 pcap_close(pd);
321 pcap_freecode(&fcode);
322 exit(status == -1 ? 1 : 0);
323 }
324
325 static void
countme(u_char * user,const struct pcap_pkthdr * h _U_,const u_char * sp _U_)326 countme(u_char *user, const struct pcap_pkthdr *h _U_, const u_char *sp _U_)
327 {
328 int *counterp = (int *)user;
329
330 (*counterp)++;
331 }
332
333 static void
usage(void)334 usage(void)
335 {
336 (void)fprintf(stderr, "Usage: %s [ -n ] [ -i interface ] [ expression ]\n",
337 program_name);
338 exit(1);
339 }
340
341 /* VARARGS */
342 static void
error(const char * fmt,...)343 error(const char *fmt, ...)
344 {
345 va_list ap;
346
347 (void)fprintf(stderr, "%s: ", program_name);
348 va_start(ap, fmt);
349 (void)vfprintf(stderr, fmt, ap);
350 va_end(ap);
351 if (*fmt) {
352 fmt += strlen(fmt);
353 if (fmt[-1] != '\n')
354 (void)fputc('\n', stderr);
355 }
356 exit(1);
357 /* NOTREACHED */
358 }
359
360 /* VARARGS */
361 static void
warning(const char * fmt,...)362 warning(const char *fmt, ...)
363 {
364 va_list ap;
365
366 (void)fprintf(stderr, "%s: WARNING: ", program_name);
367 va_start(ap, fmt);
368 (void)vfprintf(stderr, fmt, ap);
369 va_end(ap);
370 if (*fmt) {
371 fmt += strlen(fmt);
372 if (fmt[-1] != '\n')
373 (void)fputc('\n', stderr);
374 }
375 }
376
377 /*
378 * Copy arg vector into a new buffer, concatenating arguments with spaces.
379 */
380 static char *
copy_argv(register char ** argv)381 copy_argv(register char **argv)
382 {
383 register char **p;
384 register size_t len = 0;
385 char *buf;
386 char *src, *dst;
387
388 p = argv;
389 if (*p == 0)
390 return 0;
391
392 while (*p)
393 len += strlen(*p++) + 1;
394
395 buf = (char *)malloc(len);
396 if (buf == NULL)
397 error("copy_argv: malloc");
398
399 p = argv;
400 dst = buf;
401 while ((src = *p++) != NULL) {
402 while ((*dst++ = *src++) != '\0')
403 ;
404 dst[-1] = ' ';
405 }
406 dst[-1] = '\0';
407
408 return buf;
409 }
410