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
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 * 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.
32 static const char rcsid[] _U_ =
33 "@(#) $Header: /tcpdump/master/libpcap/savefile.c,v 1.183 2008-12-23 20:13:29 guy Exp $ (LBL)";
41 #include <pcap-stdinc.h>
48 #ifdef HAVE_SYS_BITYPES_H
49 #include <sys/bitypes.h>
51 #include <sys/types.h>
63 #ifdef HAVE_OS_PROTO_H
68 #include "sf-pcap-ng.h"
71 * Setting O_BINARY on DOS/Windows is a bit tricky
74 #define SET_BINMODE(f) _setmode(_fileno(f), _O_BINARY)
76 #if defined(__HIGHC__)
77 #define SET_BINMODE(f) setmode(f, O_BINARY)
79 #define SET_BINMODE(f) setmode(fileno(f), O_BINARY)
84 sf_getnonblock(pcap_t *p, char *errbuf)
87 * This is a savefile, not a live capture file, so never say
88 * it's in non-blocking mode.
94 sf_setnonblock(pcap_t *p, int nonblock, char *errbuf)
97 * This is a savefile, not a live capture file, so ignore
98 * requests to put it in non-blocking mode.
104 sf_stats(pcap_t *p, struct pcap_stat *ps)
106 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
107 "Statistics aren't available from savefiles");
113 sf_setbuff(pcap_t *p, int dim)
115 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
116 "The kernel buffer size cannot be set while reading from a file");
121 sf_setmode(pcap_t *p, int mode)
123 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
124 "impossible to set mode while reading from a file");
129 sf_setmintocopy(pcap_t *p, int size)
131 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
132 "The mintocopy parameter cannot be set while reading from a file");
138 sf_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
140 strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",
146 * Set direction flag: Which packets do we accept on a forwarding
147 * single device? IN, OUT or both?
150 sf_setdirection(pcap_t *p, pcap_direction_t d)
152 snprintf(p->errbuf, sizeof(p->errbuf),
153 "Setting direction is not supported on savefiles");
158 sf_cleanup(pcap_t *p)
160 if (p->sf.rfile != stdin)
161 (void)fclose(p->sf.rfile);
162 if (p->buffer != NULL)
167 pcap_open_offline(const char *fname, char *errbuf)
172 if (fname[0] == '-' && fname[1] == '\0')
175 #if defined(WIN32) || defined(MSDOS)
177 * We're reading from the standard input, so put it in binary
178 * mode, as savefiles are binary files.
184 #if !defined(WIN32) && !defined(MSDOS)
185 fp = fopen(fname, "r");
187 fp = fopen(fname, "rb");
190 snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", fname,
191 pcap_strerror(errno));
195 p = pcap_fopen_offline(fp, errbuf);
204 pcap_t* pcap_hopen_offline(intptr_t osfd, char *errbuf)
209 fd = _open_osfhandle(osfd, _O_RDONLY);
212 snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
216 file = _fdopen(fd, "rb");
219 snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
223 return pcap_fopen_offline(file, errbuf);
227 static int (*check_headers[])(pcap_t *, bpf_u_int32, FILE *, char *) = {
232 #define N_FILE_TYPES (sizeof check_headers / sizeof check_headers[0])
238 pcap_fopen_offline(FILE *fp, char *errbuf)
245 p = pcap_create_common("(savefile)", errbuf);
250 * Read the first 4 bytes of the file; the network analyzer dump
251 * file formats we support (pcap and pcap-ng), and several other
252 * formats we might support in the future (such as snoop, DOS and
253 * Windows Sniffer, and Microsoft Network Monitor) all have magic
254 * numbers that are unique in their first 4 bytes.
256 amt_read = fread((char *)&magic, 1, sizeof(magic), fp);
257 if (amt_read != sizeof(magic)) {
259 snprintf(errbuf, PCAP_ERRBUF_SIZE,
260 "error reading dump file: %s",
261 pcap_strerror(errno));
263 snprintf(errbuf, PCAP_ERRBUF_SIZE,
264 "truncated dump file; tried to read %lu file header bytes, only got %lu",
265 (unsigned long)sizeof(magic),
266 (unsigned long)amt_read);
272 * Try all file types.
274 for (i = 0; i < N_FILE_TYPES; i++) {
275 switch ((*check_headers[i])(p, magic, fp, errbuf)) {
279 * Error trying to read the header.
292 * Well, who knows what this mess is....
294 snprintf(errbuf, PCAP_ERRBUF_SIZE, "unknown file format");
301 /* Padding only needed for live capture fcode */
305 #if !defined(WIN32) && !defined(MSDOS)
307 * You can do "select()" and "poll()" on plain files on most
308 * platforms, and should be able to do so on pipes.
310 * You can't do "select()" on anything other than sockets in
311 * Windows, so, on Win32 systems, we don't have "selectable_fd".
313 p->selectable_fd = fileno(fp);
316 p->read_op = pcap_offline_read;
317 p->inject_op = sf_inject;
318 p->setfilter_op = install_bpf_program;
319 p->setdirection_op = sf_setdirection;
320 p->set_datalink_op = NULL; /* we don't support munging link-layer headers */
321 p->getnonblock_op = sf_getnonblock;
322 p->setnonblock_op = sf_setnonblock;
323 p->stats_op = sf_stats;
325 p->setbuff_op = sf_setbuff;
326 p->setmode_op = sf_setmode;
327 p->setmintocopy_op = sf_setmintocopy;
329 p->cleanup_op = sf_cleanup;
339 * Read packets from a capture file, and call the callback for each
341 * If cnt > 0, return after 'cnt' packets, otherwise continue until eof.
344 pcap_offline_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
346 struct bpf_insn *fcode;
351 while (status == 0) {
352 struct pcap_pkthdr h;
355 * Has "pcap_breakloop()" been called?
356 * If so, return immediately - if we haven't read any
357 * packets, clear the flag and return -2 to indicate
358 * that we were told to break out of the loop, otherwise
359 * leave the flag set, so that the *next* call will break
360 * out of the loop without having read any packets, and
361 * return the number of packets we've processed so far.
371 status = p->sf.next_packet_op(p, &h, &data);
378 if ((fcode = p->fcode.bf_insns) == NULL ||
379 bpf_filter(fcode, p->buffer, h.len, h.caplen)) {
380 (*callback)(user, &h, data);
381 if (++n >= cnt && cnt > 0)
385 /*XXX this breaks semantics tcpslice expects */