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 reject
98 * requests to put it in non-blocking mode. (If it's a
99 * pipe, it could be put in non-blocking mode, but that
100 * would significantly complicate the code to read packets,
101 * as it would have to handle reading partial packets and
102 * keeping the state of the read.)
104 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
105 "Savefiles cannot be put into non-blocking mode");
110 sf_stats(pcap_t *p, struct pcap_stat *ps)
112 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
113 "Statistics aren't available from savefiles");
119 sf_setbuff(pcap_t *p, int dim)
121 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
122 "The kernel buffer size cannot be set while reading from a file");
127 sf_setmode(pcap_t *p, int mode)
129 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
130 "impossible to set mode while reading from a file");
135 sf_setmintocopy(pcap_t *p, int size)
137 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
138 "The mintocopy parameter cannot be set while reading from a file");
144 sf_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
146 strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",
152 * Set direction flag: Which packets do we accept on a forwarding
153 * single device? IN, OUT or both?
156 sf_setdirection(pcap_t *p, pcap_direction_t d)
158 snprintf(p->errbuf, sizeof(p->errbuf),
159 "Setting direction is not supported on savefiles");
164 sf_cleanup(pcap_t *p)
166 if (p->sf.rfile != stdin)
167 (void)fclose(p->sf.rfile);
168 if (p->buffer != NULL)
170 pcap_freecode(&p->fcode);
174 pcap_open_offline(const char *fname, char *errbuf)
179 if (fname[0] == '-' && fname[1] == '\0')
182 #if defined(WIN32) || defined(MSDOS)
184 * We're reading from the standard input, so put it in binary
185 * mode, as savefiles are binary files.
191 #if !defined(WIN32) && !defined(MSDOS)
192 fp = fopen(fname, "r");
194 fp = fopen(fname, "rb");
197 snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", fname,
198 pcap_strerror(errno));
202 p = pcap_fopen_offline(fp, errbuf);
211 pcap_t* pcap_hopen_offline(intptr_t osfd, char *errbuf)
216 fd = _open_osfhandle(osfd, _O_RDONLY);
219 snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
223 file = _fdopen(fd, "rb");
226 snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
230 return pcap_fopen_offline(file, errbuf);
234 static int (*check_headers[])(pcap_t *, bpf_u_int32, FILE *, char *) = {
239 #define N_FILE_TYPES (sizeof check_headers / sizeof check_headers[0])
245 pcap_fopen_offline(FILE *fp, char *errbuf)
252 p = pcap_create_common("(savefile)", errbuf);
257 * Read the first 4 bytes of the file; the network analyzer dump
258 * file formats we support (pcap and pcap-ng), and several other
259 * formats we might support in the future (such as snoop, DOS and
260 * Windows Sniffer, and Microsoft Network Monitor) all have magic
261 * numbers that are unique in their first 4 bytes.
263 amt_read = fread((char *)&magic, 1, sizeof(magic), fp);
264 if (amt_read != sizeof(magic)) {
266 snprintf(errbuf, PCAP_ERRBUF_SIZE,
267 "error reading dump file: %s",
268 pcap_strerror(errno));
270 snprintf(errbuf, PCAP_ERRBUF_SIZE,
271 "truncated dump file; tried to read %lu file header bytes, only got %lu",
272 (unsigned long)sizeof(magic),
273 (unsigned long)amt_read);
279 * Try all file types.
281 for (i = 0; i < N_FILE_TYPES; i++) {
282 switch ((*check_headers[i])(p, magic, fp, errbuf)) {
286 * Error trying to read the header.
299 * Well, who knows what this mess is....
301 snprintf(errbuf, PCAP_ERRBUF_SIZE, "unknown file format");
308 /* Padding only needed for live capture fcode */
312 #if !defined(WIN32) && !defined(MSDOS)
314 * You can do "select()" and "poll()" on plain files on most
315 * platforms, and should be able to do so on pipes.
317 * You can't do "select()" on anything other than sockets in
318 * Windows, so, on Win32 systems, we don't have "selectable_fd".
320 p->selectable_fd = fileno(fp);
323 p->read_op = pcap_offline_read;
324 p->inject_op = sf_inject;
325 p->setfilter_op = install_bpf_program;
326 p->setdirection_op = sf_setdirection;
327 p->set_datalink_op = NULL; /* we don't support munging link-layer headers */
328 p->getnonblock_op = sf_getnonblock;
329 p->setnonblock_op = sf_setnonblock;
330 p->stats_op = sf_stats;
332 p->setbuff_op = sf_setbuff;
333 p->setmode_op = sf_setmode;
334 p->setmintocopy_op = sf_setmintocopy;
336 p->cleanup_op = sf_cleanup;
346 * Read packets from a capture file, and call the callback for each
348 * If cnt > 0, return after 'cnt' packets, otherwise continue until eof.
351 pcap_offline_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
353 struct bpf_insn *fcode;
358 while (status == 0) {
359 struct pcap_pkthdr h;
362 * Has "pcap_breakloop()" been called?
363 * If so, return immediately - if we haven't read any
364 * packets, clear the flag and return -2 to indicate
365 * that we were told to break out of the loop, otherwise
366 * leave the flag set, so that the *next* call will break
367 * out of the loop without having read any packets, and
368 * return the number of packets we've processed so far.
378 status = p->sf.next_packet_op(p, &h, &data);
385 if ((fcode = p->fcode.bf_insns) == NULL ||
386 bpf_filter(fcode, data, h.len, h.caplen)) {
387 (*callback)(user, &h, data);
388 if (++n >= cnt && cnt > 0)
392 /*XXX this breaks semantics tcpslice expects */