libpcap  1.10.1
About: libpcap is a packet filter library used by tools like tcpdump.
  Fossies Dox: libpcap-1.10.1.tar.gz  ("unofficial" and yet experimental doxygen-generated source code documentation)  

capturetest.c
Go to the documentation of this file.
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 "getopt.h"
37 #else
38  #include <unistd.h>
39 #endif
40 #include <errno.h>
41 #ifndef _WIN32
42  #include <signal.h>
43 #endif
44 #include <sys/types.h>
45 
46 #include <pcap.h>
47 
48 #include "pcap/funcattrs.h"
49 
50 #ifdef _WIN32
51  #include "portability.h"
52 #endif
53 
54 static char *program_name;
55 
56 /* Forwards */
57 static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
58 static void PCAP_NORETURN usage(void);
59 static void PCAP_NORETURN error(const char *, ...) PCAP_PRINTFLIKE(1, 2);
60 static void warning(const char *, ...) PCAP_PRINTFLIKE(1, 2);
61 static char *copy_argv(char **);
62 
63 static pcap_t *pd;
64 #ifndef _WIN32
65 static int breaksigint = 0;
66 #endif
67 
68 #ifndef _WIN32
69 static void
70 sigint_handler(int signum _U_)
71 {
72  if (breaksigint)
74 }
75 #endif
76 
77 #ifdef _WIN32
78 /*
79  * We don't have UN*X-style signals, so we don't have anything to test.
80  */
81 #define B_OPTION ""
82 #define R_OPTION ""
83 #define S_OPTION ""
84 #else
85 /*
86  * We do have UN*X-style signals (we assume that "not Windows" means "UN*X").
87  */
88 #define B_OPTION "b"
89 #define R_OPTION "r"
90 #define S_OPTION "s"
91 #endif
92 
93 #define COMMAND_OPTIONS B_OPTION "i:mn" R_OPTION S_OPTION "t:"
94 #define USAGE_OPTIONS "-" B_OPTION "mn" R_OPTION S_OPTION
95 
96 int
97 main(int argc, char **argv)
98 {
99  register int op;
100  register char *cp, *cmdbuf, *device;
101  long longarg;
102  char *p;
103  int timeout = 1000;
104  int immediate = 0;
105  int nonblock = 0;
106 #ifndef _WIN32
107  int sigrestart = 0;
108  int catchsigint = 0;
109 #endif
110  pcap_if_t *devlist;
111  bpf_u_int32 localnet, netmask;
112  struct bpf_program fcode;
113  char ebuf[PCAP_ERRBUF_SIZE];
114  int status;
115  int packet_count;
116 
117  device = NULL;
118  if ((cp = strrchr(argv[0], '/')) != NULL)
119  program_name = cp + 1;
120  else
121  program_name = argv[0];
122 
123  opterr = 0;
124  while ((op = getopt(argc, argv, COMMAND_OPTIONS)) != -1) {
125  switch (op) {
126 
127 #ifndef _WIN32
128  case 'b':
129  breaksigint = 1;
130  break;
131 #endif
132 
133  case 'i':
134  device = optarg;
135  break;
136 
137  case 'm':
138  immediate = 1;
139  break;
140 
141  case 'n':
142  nonblock = 1;
143  break;
144 
145 #ifndef _WIN32
146  case 'r':
147  sigrestart = 1;
148  break;
149 
150  case 's':
151  catchsigint = 1;
152  break;
153 #endif
154 
155  case 't':
156  longarg = strtol(optarg, &p, 10);
157  if (p == optarg || *p != '\0') {
158  error("Timeout value \"%s\" is not a number",
159  optarg);
160  /* NOTREACHED */
161  }
162  if (longarg < 0) {
163  error("Timeout value %ld is negative", longarg);
164  /* NOTREACHED */
165  }
166  if (longarg > INT_MAX) {
167  error("Timeout value %ld is too large (> %d)",
168  longarg, INT_MAX);
169  /* NOTREACHED */
170  }
171  timeout = (int)longarg;
172  break;
173 
174  default:
175  usage();
176  /* NOTREACHED */
177  }
178  }
179 
180  if (device == NULL) {
181  if (pcap_findalldevs(&devlist, ebuf) == -1)
182  error("%s", ebuf);
183  if (devlist == NULL)
184  error("no interfaces available for capture");
185  device = strdup(devlist->name);
186  pcap_freealldevs(devlist);
187  }
188  *ebuf = '\0';
189 
190 #ifndef _WIN32
191  /*
192  * If we were told to catch SIGINT, do so.
193  */
194  if (catchsigint) {
195  struct sigaction action;
196 
197  action.sa_handler = sigint_handler;
198  sigemptyset(&action.sa_mask);
199 
200  /*
201  * Should SIGINT interrupt, or restart, system calls?
202  */
203  action.sa_flags = sigrestart ? SA_RESTART : 0;
204 
205  if (sigaction(SIGINT, &action, NULL) == -1)
206  error("Can't catch SIGINT: %s\n",
207  strerror(errno));
208  }
209 #endif
210 
211  pd = pcap_create(device, ebuf);
212  if (pd == NULL)
213  error("%s", ebuf);
214  status = pcap_set_snaplen(pd, 65535);
215  if (status != 0)
216  error("%s: pcap_set_snaplen failed: %s",
217  device, pcap_statustostr(status));
218  if (immediate) {
219  status = pcap_set_immediate_mode(pd, 1);
220  if (status != 0)
221  error("%s: pcap_set_immediate_mode failed: %s",
222  device, pcap_statustostr(status));
223  }
224  status = pcap_set_timeout(pd, timeout);
225  if (status != 0)
226  error("%s: pcap_set_timeout failed: %s",
227  device, pcap_statustostr(status));
228  status = pcap_activate(pd);
229  if (status < 0) {
230  /*
231  * pcap_activate() failed.
232  */
233  error("%s: %s\n(%s)", device,
234  pcap_statustostr(status), pcap_geterr(pd));
235  } else if (status > 0) {
236  /*
237  * pcap_activate() succeeded, but it's warning us
238  * of a problem it had.
239  */
240  warning("%s: %s\n(%s)", device,
241  pcap_statustostr(status), pcap_geterr(pd));
242  }
243  if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
244  localnet = 0;
245  netmask = 0;
246  warning("%s", ebuf);
247  }
248  cmdbuf = copy_argv(&argv[optind]);
249 
250  if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
251  error("%s", pcap_geterr(pd));
252 
253  if (pcap_setfilter(pd, &fcode) < 0)
254  error("%s", pcap_geterr(pd));
255  if (pcap_setnonblock(pd, nonblock, ebuf) == -1)
256  error("pcap_setnonblock failed: %s", ebuf);
257  printf("Listening on %s\n", device);
258  for (;;) {
259  packet_count = 0;
260  status = pcap_dispatch(pd, -1, countme,
261  (u_char *)&packet_count);
262  if (status < 0)
263  break;
264  if (status != 0) {
265  printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
266  status, packet_count);
267  struct pcap_stat ps;
268  pcap_stats(pd, &ps);
269  printf("%d ps_recv, %d ps_drop, %d ps_ifdrop\n",
270  ps.ps_recv, ps.ps_drop, ps.ps_ifdrop);
271  }
272  }
273  if (status == -2) {
274  /*
275  * We got interrupted, so perhaps we didn't
276  * manage to finish a line we were printing.
277  * Print an extra newline, just in case.
278  */
279  putchar('\n');
280  printf("Broken out of loop from SIGINT handler\n");
281  }
282  (void)fflush(stdout);
283  if (status == -1) {
284  /*
285  * Error. Report it.
286  */
287  (void)fprintf(stderr, "%s: pcap_dispatch: %s\n",
289  }
290  pcap_close(pd);
291  pcap_freecode(&fcode);
292  free(cmdbuf);
293  exit(status == -1 ? 1 : 0);
294 }
295 
296 static void
297 countme(u_char *user, const struct pcap_pkthdr *h _U_, const u_char *sp _U_)
298 {
299  int *counterp = (int *)user;
300 
301  (*counterp)++;
302 }
303 
304 static void
305 usage(void)
306 {
307  (void)fprintf(stderr, "Usage: %s [ " USAGE_OPTIONS " ] [ -i interface ] [ -t timeout] [expression]\n",
308  program_name);
309  exit(1);
310 }
311 
312 /* VARARGS */
313 static void
314 error(const char *fmt, ...)
315 {
316  va_list ap;
317 
318  (void)fprintf(stderr, "%s: ", program_name);
319  va_start(ap, fmt);
320  (void)vfprintf(stderr, fmt, ap);
321  va_end(ap);
322  if (*fmt) {
323  fmt += strlen(fmt);
324  if (fmt[-1] != '\n')
325  (void)fputc('\n', stderr);
326  }
327  exit(1);
328  /* NOTREACHED */
329 }
330 
331 /* VARARGS */
332 static void
333 warning(const char *fmt, ...)
334 {
335  va_list ap;
336 
337  (void)fprintf(stderr, "%s: WARNING: ", program_name);
338  va_start(ap, fmt);
339  (void)vfprintf(stderr, fmt, ap);
340  va_end(ap);
341  if (*fmt) {
342  fmt += strlen(fmt);
343  if (fmt[-1] != '\n')
344  (void)fputc('\n', stderr);
345  }
346 }
347 
348 /*
349  * Copy arg vector into a new buffer, concatenating arguments with spaces.
350  */
351 static char *
352 copy_argv(register char **argv)
353 {
354  register char **p;
355  register size_t len = 0;
356  char *buf;
357  char *src, *dst;
358 
359  p = argv;
360  if (*p == 0)
361  return 0;
362 
363  while (*p)
364  len += strlen(*p++) + 1;
365 
366  buf = (char *)malloc(len);
367  if (buf == NULL)
368  error("copy_argv: malloc");
369 
370  p = argv;
371  dst = buf;
372  while ((src = *p++) != NULL) {
373  while ((*dst++ = *src++) != '\0')
374  ;
375  dst[-1] = ' ';
376  }
377  dst[-1] = '\0';
378 
379  return buf;
380 }
u_int bpf_u_int32
Definition: bpf.h:98
static void warning(const char *,...)
Definition: capturetest.c:333
#define USAGE_OPTIONS
Definition: capturetest.c:94
#define COMMAND_OPTIONS
Definition: capturetest.c:93
static void error(const char *,...)
Definition: capturetest.c:314
static pcap_t * pd
Definition: capturetest.c:63
static char * program_name
Definition: capturetest.c:54
static const char copyright[]
Definition: capturetest.c:25
static char * copy_argv(char **)
static void sigint_handler(int signum)
Definition: capturetest.c:70
int main(int argc, char **argv)
Definition: capturetest.c:97
static void countme(u_char *, const struct pcap_pkthdr *, const u_char *)
Definition: capturetest.c:297
static int breaksigint
Definition: capturetest.c:65
static void usage(void)
Definition: capturetest.c:305
#define PCAP_NORETURN
Definition: funcattrs.h:248
#define PCAP_PRINTFLIKE(x, y)
Definition: funcattrs.h:270
int pcap_compile(pcap_t *p, struct bpf_program *program, const char *buf, int optimize, bpf_u_int32 mask)
Definition: gencode.c:724
void pcap_freecode(struct bpf_program *program)
Definition: gencode.c:900
int optind
Definition: getopt.c:45
char * optarg
Definition: getopt.c:48
int opterr
Definition: getopt.c:44
char * strerror(int)
int getopt(int, char *const *, const char *)
Definition: getopt.c:59
long strtol(const char *, char **, int)
int printf(const char *,...)
int pcap_lookupnet(const char *device, bpf_u_int32 *localnet, bpf_u_int32 *netmask, char *errbuf)
Definition: pcap-dos.c:518
#define _U_
Definition: pcap-dos.h:93
int errno
#define PCAP_ERRBUF_SIZE
Definition: pcap.h:152
int pcap_set_snaplen(pcap_t *p, int snaplen)
Definition: pcap.c:2548
int pcap_set_timeout(pcap_t *p, int timeout_ms)
Definition: pcap.c:2575
void pcap_breakloop(pcap_t *p)
Definition: pcap.c:2921
void pcap_freealldevs(pcap_if_t *alldevs)
Definition: pcap.c:1431
int pcap_activate(pcap_t *p)
Definition: pcap.c:2708
int pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf)
Definition: pcap.c:3555
int pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
Definition: pcap.c:2882
int pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
Definition: pcap.c:711
char * pcap_geterr(pcap_t *p)
Definition: pcap.c:3505
const char * pcap_statustostr(int errnum)
Definition: pcap.c:3610
pcap_t * pcap_create(const char *device, char *errbuf)
Definition: pcap.c:2252
void pcap_close(pcap_t *p)
Definition: pcap.c:4065
int pcap_stats(pcap_t *p, struct pcap_stat *ps)
Definition: pcap.c:3736
int pcap_set_immediate_mode(pcap_t *p, int immediate)
Definition: pcap.c:2629
int pcap_setfilter(pcap_t *p, struct bpf_program *fp)
Definition: pcap.c:3695
Definition: pcap.h:301
char * name
Definition: pcap.h:303
u_int ps_drop
Definition: pcap.h:256
u_int ps_recv
Definition: pcap.h:255
u_int ps_ifdrop
Definition: pcap.h:257
Definition: pcap-int.h:200