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.
36 #include <pcap-stdinc.h>
43 #ifdef HAVE_SYS_BITYPES_H
44 #include <sys/bitypes.h>
46 #include <sys/types.h>
57 #ifdef HAVE_OS_PROTO_H
62 #include "sf-pcap-ng.h"
66 * These aren't exported on Windows, because they would only work if both
67 * WinPcap and the code using it were to use the Universal CRT; otherwise,
68 * a FILE structure in WinPcap and a FILE structure in the code using it
69 * could be different if they're using different versions of the C runtime.
71 * Instead, pcap/pcap.h defines them as macros that wrap the hopen versions,
72 * with the wrappers calling _fileno() and _get_osfhandle() themselves,
73 * so that they convert the appropriate CRT version's FILE structure to
74 * a HANDLE (which is OS-defined, not CRT-defined, and is part of the Win32
77 static pcap_t *pcap_fopen_offline_with_tstamp_precision(FILE *, u_int, char *);
78 static pcap_t *pcap_fopen_offline(FILE *, char *);
82 * Setting O_BINARY on DOS/Windows is a bit tricky
85 #define SET_BINMODE(f) _setmode(_fileno(f), _O_BINARY)
87 #if defined(__HIGHC__)
88 #define SET_BINMODE(f) setmode(f, O_BINARY)
90 #define SET_BINMODE(f) setmode(fileno(f), O_BINARY)
95 sf_getnonblock(pcap_t *p, char *errbuf)
98 * This is a savefile, not a live capture file, so never say
99 * it's in non-blocking mode.
105 sf_setnonblock(pcap_t *p, int nonblock, char *errbuf)
108 * This is a savefile, not a live capture file, so reject
109 * requests to put it in non-blocking mode. (If it's a
110 * pipe, it could be put in non-blocking mode, but that
111 * would significantly complicate the code to read packets,
112 * as it would have to handle reading partial packets and
113 * keeping the state of the read.)
115 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
116 "Savefiles cannot be put into non-blocking mode");
121 sf_stats(pcap_t *p, struct pcap_stat *ps)
123 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
124 "Statistics aren't available from savefiles");
129 static struct pcap_stat *
130 sf_stats_ex(pcap_t *p, int *size)
132 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
133 "Statistics aren't available from savefiles");
138 sf_setbuff(pcap_t *p, int dim)
140 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
141 "The kernel buffer size cannot be set while reading from a file");
146 sf_setmode(pcap_t *p, int mode)
148 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
149 "impossible to set mode while reading from a file");
154 sf_setmintocopy(pcap_t *p, int size)
156 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
157 "The mintocopy parameter cannot be set while reading from a file");
162 sf_getevent(pcap_t *pcap)
164 (void)pcap_snprintf(pcap->errbuf, sizeof(pcap->errbuf),
165 "The read event cannot be retrieved while reading from a file");
166 return (INVALID_HANDLE_VALUE);
170 sf_oid_get_request(pcap_t *p, bpf_u_int32 oid _U_, void *data _U_,
173 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
174 "An OID get request cannot be performed on a file");
179 sf_oid_set_request(pcap_t *p, bpf_u_int32 oid _U_, const void *data _U_,
182 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
183 "An OID set request cannot be performed on a file");
188 sf_sendqueue_transmit(pcap_t *p, pcap_send_queue *queue, int sync)
190 strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",
196 sf_setuserbuffer(pcap_t *p, int size)
198 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
199 "The user buffer cannot be set when reading from a file");
204 sf_live_dump(pcap_t *p, char *filename, int maxsize, int maxpacks)
206 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
207 "Live packet dumping cannot be performed when reading from a file");
212 sf_live_dump_ended(pcap_t *p, int sync)
214 pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
215 "Live packet dumping cannot be performed on a pcap_open_dead pcap_t");
219 static PAirpcapHandle
220 sf_get_airpcap_handle(pcap_t *pcap)
227 sf_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
229 strlcpy(p->errbuf, "Sending packets isn't supported on savefiles",
235 * Set direction flag: Which packets do we accept on a forwarding
236 * single device? IN, OUT or both?
239 sf_setdirection(pcap_t *p, pcap_direction_t d)
241 pcap_snprintf(p->errbuf, sizeof(p->errbuf),
242 "Setting direction is not supported on savefiles");
247 sf_cleanup(pcap_t *p)
249 if (p->rfile != stdin)
250 (void)fclose(p->rfile);
251 if (p->buffer != NULL)
253 pcap_freecode(&p->fcode);
257 * fopen's safe version on Windows.
260 FILE *fopen_safe(const char *filename, const char* mode)
264 errno = fopen_s(&fp, filename, mode);
273 pcap_open_offline_with_tstamp_precision(const char *fname, u_int precision,
280 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
281 "A null pointer was supplied as the file name");
284 if (fname[0] == '-' && fname[1] == '\0')
287 #if defined(_WIN32) || defined(MSDOS)
289 * We're reading from the standard input, so put it in binary
290 * mode, as savefiles are binary files.
296 #if !defined(_WIN32) && !defined(MSDOS)
297 fp = fopen(fname, "r");
299 fp = fopen(fname, "rb");
302 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", fname,
303 pcap_strerror(errno));
307 p = pcap_fopen_offline_with_tstamp_precision(fp, precision, errbuf);
316 pcap_open_offline(const char *fname, char *errbuf)
318 return (pcap_open_offline_with_tstamp_precision(fname,
319 PCAP_TSTAMP_PRECISION_MICRO, errbuf));
323 pcap_t* pcap_hopen_offline_with_tstamp_precision(intptr_t osfd, u_int precision,
329 fd = _open_osfhandle(osfd, _O_RDONLY);
332 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
336 file = _fdopen(fd, "rb");
339 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno));
343 return pcap_fopen_offline_with_tstamp_precision(file, precision,
347 pcap_t* pcap_hopen_offline(intptr_t osfd, char *errbuf)
349 return pcap_hopen_offline_with_tstamp_precision(osfd,
350 PCAP_TSTAMP_PRECISION_MICRO, errbuf);
354 static pcap_t *(*check_headers[])(bpf_u_int32, FILE *, u_int, char *, int *) = {
359 #define N_FILE_TYPES (sizeof check_headers / sizeof check_headers[0])
365 pcap_fopen_offline_with_tstamp_precision(FILE *fp, u_int precision,
375 * Read the first 4 bytes of the file; the network analyzer dump
376 * file formats we support (pcap and pcap-ng), and several other
377 * formats we might support in the future (such as snoop, DOS and
378 * Windows Sniffer, and Microsoft Network Monitor) all have magic
379 * numbers that are unique in their first 4 bytes.
381 amt_read = fread((char *)&magic, 1, sizeof(magic), fp);
382 if (amt_read != sizeof(magic)) {
384 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
385 "error reading dump file: %s",
386 pcap_strerror(errno));
388 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
389 "truncated dump file; tried to read %lu file header bytes, only got %lu",
390 (unsigned long)sizeof(magic),
391 (unsigned long)amt_read);
397 * Try all file types.
399 for (i = 0; i < N_FILE_TYPES; i++) {
400 p = (*check_headers[i])(magic, fp, precision, errbuf, &err);
402 /* Yup, that's it. */
407 * Error trying to read the header.
414 * Well, who knows what this mess is....
416 pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "unknown file format");
422 /* Padding only needed for live capture fcode */
425 #if !defined(_WIN32) && !defined(MSDOS)
427 * You can do "select()" and "poll()" on plain files on most
428 * platforms, and should be able to do so on pipes.
430 * You can't do "select()" on anything other than sockets in
431 * Windows, so, on Win32 systems, we don't have "selectable_fd".
433 p->selectable_fd = fileno(fp);
436 p->read_op = pcap_offline_read;
437 p->inject_op = sf_inject;
438 p->setfilter_op = install_bpf_program;
439 p->setdirection_op = sf_setdirection;
440 p->set_datalink_op = NULL; /* we don't support munging link-layer headers */
441 p->getnonblock_op = sf_getnonblock;
442 p->setnonblock_op = sf_setnonblock;
443 p->stats_op = sf_stats;
445 p->stats_ex_op = sf_stats_ex;
446 p->setbuff_op = sf_setbuff;
447 p->setmode_op = sf_setmode;
448 p->setmintocopy_op = sf_setmintocopy;
449 p->getevent_op = sf_getevent;
450 p->oid_get_request_op = sf_oid_get_request;
451 p->oid_set_request_op = sf_oid_set_request;
452 p->sendqueue_transmit_op = sf_sendqueue_transmit;
453 p->setuserbuffer_op = sf_setuserbuffer;
454 p->live_dump_op = sf_live_dump;
455 p->live_dump_ended_op = sf_live_dump_ended;
456 p->get_airpcap_handle_op = sf_get_airpcap_handle;
460 * For offline captures, the standard one-shot callback can
461 * be used for pcap_next()/pcap_next_ex().
463 p->oneshot_callback = pcap_oneshot;
466 * Savefiles never require special BPF code generation.
468 p->bpf_codegen_flags = 0;
479 pcap_fopen_offline(FILE *fp, char *errbuf)
481 return (pcap_fopen_offline_with_tstamp_precision(fp,
482 PCAP_TSTAMP_PRECISION_MICRO, errbuf));
486 * Read packets from a capture file, and call the callback for each
488 * If cnt > 0, return after 'cnt' packets, otherwise continue until eof.
491 pcap_offline_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
493 struct bpf_insn *fcode;
498 while (status == 0) {
499 struct pcap_pkthdr h;
502 * Has "pcap_breakloop()" been called?
503 * If so, return immediately - if we haven't read any
504 * packets, clear the flag and return -2 to indicate
505 * that we were told to break out of the loop, otherwise
506 * leave the flag set, so that the *next* call will break
507 * out of the loop without having read any packets, and
508 * return the number of packets we've processed so far.
518 status = p->next_packet_op(p, &h, &data);
525 if ((fcode = p->fcode.bf_insns) == NULL ||
526 bpf_filter(fcode, data, h.len, h.caplen)) {
527 (*callback)(user, &h, data);
528 if (++n >= cnt && cnt > 0)
532 /*XXX this breaks semantics tcpslice expects */