2 * Copyright (c) 1993, 1994, 1995, 1996, 1997
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
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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 * savefile.c - supports offline use of tcpdump
22 * Extraction/creation by Jeffrey Mogul, DECWRL
23 * Modified by Steve McCanne, LBL.
25 * Used to save the received packet headers, after filtering, to
26 * a file, and then read them later.
27 * The first record in the file contains saved values for the machine
28 * dependent values so we can print the dump file on any architecture.
36 #include <pcap-stdinc.h>
43 #ifdef HAVE_SYS_BITYPES_H
44 #include <sys/bitypes.h>
46 #include <sys/types.h>
58 #ifdef HAVE_OS_PROTO_H
63 #include "sf-pcap-ng.h"
66 * Setting O_BINARY on DOS/Windows is a bit tricky
69 #define SET_BINMODE(f) _setmode(_fileno(f), _O_BINARY)
71 #if defined(__HIGHC__)
72 #define SET_BINMODE(f) setmode(f, O_BINARY)
74 #define SET_BINMODE(f) setmode(fileno(f), O_BINARY)
79 sf_getnonblock(pcap_t *p, char *errbuf)
82 * This is a savefile, not a live capture file, so never say
83 * it's in non-blocking mode.
89 sf_setnonblock(pcap_t *p, int nonblock, char *errbuf)
92 * This is a savefile, not a live capture file, so reject
93 * requests to put it in non-blocking mode. (If it's a
94 * pipe, it could be put in non-blocking mode, but that
95 * would significantly complicate the code to read packets,
96 * as it would have to handle reading partial packets and
97 * keeping the state of the read.)
99 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
100 "Savefiles cannot be put into non-blocking mode");
105 sf_stats(pcap_t *p, struct pcap_stat *ps)
107 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
108 "Statistics aren't available from savefiles");
114 sf_setbuff(pcap_t *p, int dim)
116 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
117 "The kernel buffer size cannot be set while reading from a file");
122 sf_setmode(pcap_t *p, int mode)
124 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
125 "impossible to set mode while reading from a file");
130 sf_setmintocopy(pcap_t *p, int size)
132 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
133 "The mintocopy parameter cannot be set while reading from a file");
139 sf_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
141 strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",
147 * Set direction flag: Which packets do we accept on a forwarding
148 * single device? IN, OUT or both?
151 sf_setdirection(pcap_t *p, pcap_direction_t d)
153 snprintf(p->errbuf, sizeof(p->errbuf),
154 "Setting direction is not supported on savefiles");
159 sf_cleanup(pcap_t *p)
161 if (p->rfile != stdin)
162 (void)fclose(p->rfile);
163 if (p->buffer != NULL)
165 pcap_freecode(&p->fcode);
169 pcap_open_offline_with_tstamp_precision(const char *fname, u_int precision,
175 if (fname[0] == '-' && fname[1] == '\0')
178 #if defined(WIN32) || defined(MSDOS)
180 * We're reading from the standard input, so put it in binary
181 * mode, as savefiles are binary files.
187 #if !defined(WIN32) && !defined(MSDOS)
188 fp = fopen(fname, "r");
190 fp = fopen(fname, "rb");
193 snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", fname,
194 pcap_strerror(errno));
198 p = pcap_fopen_offline_with_tstamp_precision(fp, precision, errbuf);
207 pcap_open_offline(const char *fname, char *errbuf)
209 return (pcap_open_offline_with_tstamp_precision(fname,
210 PCAP_TSTAMP_PRECISION_MICRO, errbuf));
214 pcap_t* pcap_hopen_offline_with_tstamp_precision(intptr_t osfd, u_int precision,
220 fd = _open_osfhandle(osfd, _O_RDONLY);
223 snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
227 file = _fdopen(fd, "rb");
230 snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
234 return pcap_fopen_offline_with_tstamp_precision(file, precision,
238 pcap_t* pcap_hopen_offline(intptr_t osfd, char *errbuf)
240 return pcap_hopen_offline_with_tstamp_precision(osfd,
241 PCAP_TSTAMP_PRECISION_MICRO, errbuf);
245 static pcap_t *(*check_headers[])(bpf_u_int32, FILE *, u_int, char *, int *) = {
250 #define N_FILE_TYPES (sizeof check_headers / sizeof check_headers[0])
256 pcap_fopen_offline_with_tstamp_precision(FILE *fp, u_int precision,
266 * Read the first 4 bytes of the file; the network analyzer dump
267 * file formats we support (pcap and pcap-ng), and several other
268 * formats we might support in the future (such as snoop, DOS and
269 * Windows Sniffer, and Microsoft Network Monitor) all have magic
270 * numbers that are unique in their first 4 bytes.
272 amt_read = fread((char *)&magic, 1, sizeof(magic), fp);
273 if (amt_read != sizeof(magic)) {
275 snprintf(errbuf, PCAP_ERRBUF_SIZE,
276 "error reading dump file: %s",
277 pcap_strerror(errno));
279 snprintf(errbuf, PCAP_ERRBUF_SIZE,
280 "truncated dump file; tried to read %lu file header bytes, only got %lu",
281 (unsigned long)sizeof(magic),
282 (unsigned long)amt_read);
288 * Try all file types.
290 for (i = 0; i < N_FILE_TYPES; i++) {
291 p = (*check_headers[i])(magic, fp, precision, errbuf, &err);
293 /* Yup, that's it. */
298 * Error trying to read the header.
305 * Well, who knows what this mess is....
307 snprintf(errbuf, PCAP_ERRBUF_SIZE, "unknown file format");
313 /* Padding only needed for live capture fcode */
316 #if !defined(WIN32) && !defined(MSDOS)
318 * You can do "select()" and "poll()" on plain files on most
319 * platforms, and should be able to do so on pipes.
321 * You can't do "select()" on anything other than sockets in
322 * Windows, so, on Win32 systems, we don't have "selectable_fd".
324 p->selectable_fd = fileno(fp);
327 p->read_op = pcap_offline_read;
328 p->inject_op = sf_inject;
329 p->setfilter_op = install_bpf_program;
330 p->setdirection_op = sf_setdirection;
331 p->set_datalink_op = NULL; /* we don't support munging link-layer headers */
332 p->getnonblock_op = sf_getnonblock;
333 p->setnonblock_op = sf_setnonblock;
334 p->stats_op = sf_stats;
336 p->setbuff_op = sf_setbuff;
337 p->setmode_op = sf_setmode;
338 p->setmintocopy_op = sf_setmintocopy;
342 * For offline captures, the standard one-shot callback can
343 * be used for pcap_next()/pcap_next_ex().
345 p->oneshot_callback = pcap_oneshot;
356 pcap_fopen_offline(FILE *fp, char *errbuf)
358 return (pcap_fopen_offline_with_tstamp_precision(fp,
359 PCAP_TSTAMP_PRECISION_MICRO, errbuf));
363 * Read packets from a capture file, and call the callback for each
365 * If cnt > 0, return after 'cnt' packets, otherwise continue until eof.
368 pcap_offline_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
370 struct bpf_insn *fcode;
375 while (status == 0) {
376 struct pcap_pkthdr h;
379 * Has "pcap_breakloop()" been called?
380 * If so, return immediately - if we haven't read any
381 * packets, clear the flag and return -2 to indicate
382 * that we were told to break out of the loop, otherwise
383 * leave the flag set, so that the *next* call will break
384 * out of the loop without having read any packets, and
385 * return the number of packets we've processed so far.
395 status = p->next_packet_op(p, &h, &data);
402 if ((fcode = p->fcode.bf_insns) == NULL ||
403 bpf_filter(fcode, data, h.len, h.caplen)) {
404 (*callback)(user, &h, data);
405 if (++n >= cnt && cnt > 0)
409 /*XXX this breaks semantics tcpslice expects */