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 */