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.
35 #include <pcap-types.h>
49 #ifdef HAVE_OS_PROTO_H
54 #include "sf-pcapng.h"
58 * These aren't exported on Windows, because they would only work if both
59 * WinPcap and the code using it were to use the Universal CRT; otherwise,
60 * a FILE structure in WinPcap and a FILE structure in the code using it
61 * could be different if they're using different versions of the C runtime.
63 * Instead, pcap/pcap.h defines them as macros that wrap the hopen versions,
64 * with the wrappers calling _fileno() and _get_osfhandle() themselves,
65 * so that they convert the appropriate CRT version's FILE structure to
66 * a HANDLE (which is OS-defined, not CRT-defined, and is part of the Win32
69 static pcap_t *pcap_fopen_offline_with_tstamp_precision(FILE *, u_int, char *);
70 static pcap_t *pcap_fopen_offline(FILE *, char *);
74 * Setting O_BINARY on DOS/Windows is a bit tricky
77 #define SET_BINMODE(f) _setmode(_fileno(f), _O_BINARY)
79 #if defined(__HIGHC__)
80 #define SET_BINMODE(f) setmode(f, O_BINARY)
82 #define SET_BINMODE(f) setmode(fileno(f), O_BINARY)
87 sf_getnonblock(pcap_t *p _U_)
90 * This is a savefile, not a live capture file, so never say
91 * it's in non-blocking mode.
97 sf_setnonblock(pcap_t *p, int nonblock _U_)
100 * This is a savefile, not a live capture file, so reject
101 * requests to put it in non-blocking mode. (If it's a
102 * pipe, it could be put in non-blocking mode, but that
103 * would significantly complicate the code to read packets,
104 * as it would have to handle reading partial packets and
105 * keeping the state of the read.)
107 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
108 "Savefiles cannot be put into non-blocking mode");
113 sf_stats(pcap_t *p, struct pcap_stat *ps _U_)
115 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
116 "Statistics aren't available from savefiles");
121 static struct pcap_stat *
122 sf_stats_ex(pcap_t *p, int *size)
124 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
125 "Statistics aren't available from savefiles");
130 sf_setbuff(pcap_t *p, int dim)
132 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
133 "The kernel buffer size cannot be set while reading from a file");
138 sf_setmode(pcap_t *p, int mode)
140 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
141 "impossible to set mode while reading from a file");
146 sf_setmintocopy(pcap_t *p, int size)
148 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
149 "The mintocopy parameter cannot be set while reading from a file");
154 sf_getevent(pcap_t *pcap)
156 (void)pcap_snprintf(pcap->errbuf, sizeof(pcap->errbuf),
157 "The read event cannot be retrieved while reading from a file");
158 return (INVALID_HANDLE_VALUE);
162 sf_oid_get_request(pcap_t *p, bpf_u_int32 oid _U_, void *data _U_,
165 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
166 "An OID get request cannot be performed on a file");
171 sf_oid_set_request(pcap_t *p, bpf_u_int32 oid _U_, const void *data _U_,
174 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
175 "An OID set request cannot be performed on a file");
180 sf_sendqueue_transmit(pcap_t *p, pcap_send_queue *queue, int sync)
182 strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",
188 sf_setuserbuffer(pcap_t *p, int size)
190 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
191 "The user buffer cannot be set when reading from a file");
196 sf_live_dump(pcap_t *p, char *filename, int maxsize, int maxpacks)
198 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
199 "Live packet dumping cannot be performed when reading from a file");
204 sf_live_dump_ended(pcap_t *p, int sync)
206 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
207 "Live packet dumping cannot be performed on a pcap_open_dead pcap_t");
211 static PAirpcapHandle
212 sf_get_airpcap_handle(pcap_t *pcap)
219 sf_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
221 strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",
227 * Set direction flag: Which packets do we accept on a forwarding
228 * single device? IN, OUT or both?
231 sf_setdirection(pcap_t *p, pcap_direction_t d _U_)
233 pcap_snprintf(p->errbuf, sizeof(p->errbuf),
234 "Setting direction is not supported on savefiles");
239 sf_cleanup(pcap_t *p)
241 if (p->rfile != stdin)
242 (void)fclose(p->rfile);
243 if (p->buffer != NULL)
245 pcap_freecode(&p->fcode);
249 pcap_open_offline_with_tstamp_precision(const char *fname, u_int precision,
256 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
257 "A null pointer was supplied as the file name");
260 if (fname[0] == '-' && fname[1] == '\0')
263 #if defined(_WIN32) || defined(MSDOS)
265 * We're reading from the standard input, so put it in binary
266 * mode, as savefiles are binary files.
273 * "b" is supported as of C90, so *all* UN*Xes should
274 * support it, even though it does nothing. It's
275 * required on Windows, as the file is a binary file
276 * and must be read in binary mode.
278 fp = fopen(fname, "rb");
280 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
285 p = pcap_fopen_offline_with_tstamp_precision(fp, precision, errbuf);
294 pcap_open_offline(const char *fname, char *errbuf)
296 return (pcap_open_offline_with_tstamp_precision(fname,
297 PCAP_TSTAMP_PRECISION_MICRO, errbuf));
301 pcap_t* pcap_hopen_offline_with_tstamp_precision(intptr_t osfd, u_int precision,
307 fd = _open_osfhandle(osfd, _O_RDONLY);
310 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
311 errno, "_open_osfhandle");
315 file = _fdopen(fd, "rb");
318 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
323 return pcap_fopen_offline_with_tstamp_precision(file, precision,
327 pcap_t* pcap_hopen_offline(intptr_t osfd, char *errbuf)
329 return pcap_hopen_offline_with_tstamp_precision(osfd,
330 PCAP_TSTAMP_PRECISION_MICRO, errbuf);
334 static pcap_t *(*check_headers[])(bpf_u_int32, FILE *, u_int, char *, int *) = {
339 #define N_FILE_TYPES (sizeof check_headers / sizeof check_headers[0])
345 pcap_fopen_offline_with_tstamp_precision(FILE *fp, u_int precision,
355 * Read the first 4 bytes of the file; the network analyzer dump
356 * file formats we support (pcap and pcapng), and several other
357 * formats we might support in the future (such as snoop, DOS and
358 * Windows Sniffer, and Microsoft Network Monitor) all have magic
359 * numbers that are unique in their first 4 bytes.
361 amt_read = fread((char *)&magic, 1, sizeof(magic), fp);
362 if (amt_read != sizeof(magic)) {
364 pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
365 errno, "error reading dump file");
367 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
368 "truncated dump file; tried to read %lu file header bytes, only got %lu",
369 (unsigned long)sizeof(magic),
370 (unsigned long)amt_read);
376 * Try all file types.
378 for (i = 0; i < N_FILE_TYPES; i++) {
379 p = (*check_headers[i])(magic, fp, precision, errbuf, &err);
381 /* Yup, that's it. */
386 * Error trying to read the header.
393 * Well, who knows what this mess is....
395 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "unknown file format");
401 /* Padding only needed for live capture fcode */
404 #if !defined(_WIN32) && !defined(MSDOS)
406 * You can do "select()" and "poll()" on plain files on most
407 * platforms, and should be able to do so on pipes.
409 * You can't do "select()" on anything other than sockets in
410 * Windows, so, on Win32 systems, we don't have "selectable_fd".
412 p->selectable_fd = fileno(fp);
415 p->read_op = pcap_offline_read;
416 p->inject_op = sf_inject;
417 p->setfilter_op = install_bpf_program;
418 p->setdirection_op = sf_setdirection;
419 p->set_datalink_op = NULL; /* we don't support munging link-layer headers */
420 p->getnonblock_op = sf_getnonblock;
421 p->setnonblock_op = sf_setnonblock;
422 p->stats_op = sf_stats;
424 p->stats_ex_op = sf_stats_ex;
425 p->setbuff_op = sf_setbuff;
426 p->setmode_op = sf_setmode;
427 p->setmintocopy_op = sf_setmintocopy;
428 p->getevent_op = sf_getevent;
429 p->oid_get_request_op = sf_oid_get_request;
430 p->oid_set_request_op = sf_oid_set_request;
431 p->sendqueue_transmit_op = sf_sendqueue_transmit;
432 p->setuserbuffer_op = sf_setuserbuffer;
433 p->live_dump_op = sf_live_dump;
434 p->live_dump_ended_op = sf_live_dump_ended;
435 p->get_airpcap_handle_op = sf_get_airpcap_handle;
439 * For offline captures, the standard one-shot callback can
440 * be used for pcap_next()/pcap_next_ex().
442 p->oneshot_callback = pcap_oneshot;
445 * Savefiles never require special BPF code generation.
447 p->bpf_codegen_flags = 0;
458 pcap_fopen_offline(FILE *fp, char *errbuf)
460 return (pcap_fopen_offline_with_tstamp_precision(fp,
461 PCAP_TSTAMP_PRECISION_MICRO, errbuf));
465 * Read packets from a capture file, and call the callback for each
467 * If cnt > 0, return after 'cnt' packets, otherwise continue until eof.
470 pcap_offline_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
472 struct bpf_insn *fcode;
477 while (status == 0) {
478 struct pcap_pkthdr h;
481 * Has "pcap_breakloop()" been called?
482 * If so, return immediately - if we haven't read any
483 * packets, clear the flag and return -2 to indicate
484 * that we were told to break out of the loop, otherwise
485 * leave the flag set, so that the *next* call will break
486 * out of the loop without having read any packets, and
487 * return the number of packets we've processed so far.
497 status = p->next_packet_op(p, &h, &data);
504 if ((fcode = p->fcode.bf_insns) == NULL ||
505 bpf_filter(fcode, data, h.len, h.caplen)) {
506 (*callback)(user, &h, data);
507 if (++n >= cnt && cnt > 0)
511 /*XXX this breaks semantics tcpslice expects */