diff options
Diffstat (limited to 'savefile.c')
-rw-r--r-- | savefile.c | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/savefile.c b/savefile.c new file mode 100644 index 0000000..8115749 --- /dev/null +++ b/savefile.c @@ -0,0 +1,394 @@ +/* + * Copyright (c) 1993, 1994, 1995, 1996, 1997 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that: (1) source code distributions + * retain the above copyright notice and this paragraph in its entirety, (2) + * distributions including binary code include the above copyright notice and + * this paragraph in its entirety in the documentation or other materials + * provided with the distribution, and (3) all advertising materials mentioning + * features or use of this software display the following acknowledgement: + * ``This product includes software developed by the University of California, + * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of + * the University nor the names of its contributors may be used to endorse + * or promote products derived from this software without specific prior + * written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + * + * savefile.c - supports offline use of tcpdump + * Extraction/creation by Jeffrey Mogul, DECWRL + * Modified by Steve McCanne, LBL. + * + * Used to save the received packet headers, after filtering, to + * a file, and then read them later. + * The first record in the file contains saved values for the machine + * dependent values so we can print the dump file on any architecture. + */ + +#ifndef lint +static const char rcsid[] _U_ = + "@(#) $Header: /tcpdump/master/libpcap/savefile.c,v 1.183 2008-12-23 20:13:29 guy Exp $ (LBL)"; +#endif + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#ifdef WIN32 +#include <pcap-stdinc.h> +#else /* WIN32 */ +#if HAVE_INTTYPES_H +#include <inttypes.h> +#elif HAVE_STDINT_H +#include <stdint.h> +#endif +#ifdef HAVE_SYS_BITYPES_H +#include <sys/bitypes.h> +#endif +#include <sys/types.h> +#endif /* WIN32 */ + +#include <errno.h> +#include <memory.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "pcap-int.h" +#include "pcap/usb.h" + +#ifdef HAVE_OS_PROTO_H +#include "os-proto.h" +#endif + +#include "sf-pcap.h" +#include "sf-pcap-ng.h" + +/* + * Setting O_BINARY on DOS/Windows is a bit tricky + */ +#if defined(WIN32) + #define SET_BINMODE(f) _setmode(_fileno(f), _O_BINARY) +#elif defined(MSDOS) + #if defined(__HIGHC__) + #define SET_BINMODE(f) setmode(f, O_BINARY) + #else + #define SET_BINMODE(f) setmode(fileno(f), O_BINARY) + #endif +#endif + +static int +sf_getnonblock(pcap_t *p, char *errbuf) +{ + /* + * This is a savefile, not a live capture file, so never say + * it's in non-blocking mode. + */ + return (0); +} + +static int +sf_setnonblock(pcap_t *p, int nonblock, char *errbuf) +{ + /* + * This is a savefile, not a live capture file, so reject + * requests to put it in non-blocking mode. (If it's a + * pipe, it could be put in non-blocking mode, but that + * would significantly complicate the code to read packets, + * as it would have to handle reading partial packets and + * keeping the state of the read.) + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "Savefiles cannot be put into non-blocking mode"); + return (-1); +} + +static int +sf_stats(pcap_t *p, struct pcap_stat *ps) +{ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "Statistics aren't available from savefiles"); + return (-1); +} + +#ifdef WIN32 +static int +sf_setbuff(pcap_t *p, int dim) +{ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "The kernel buffer size cannot be set while reading from a file"); + return (-1); +} + +static int +sf_setmode(pcap_t *p, int mode) +{ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "impossible to set mode while reading from a file"); + return (-1); +} + +static int +sf_setmintocopy(pcap_t *p, int size) +{ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "The mintocopy parameter cannot be set while reading from a file"); + return (-1); +} +#endif + +static int +sf_inject(pcap_t *p, const void *buf _U_, size_t size _U_) +{ + strlcpy(p->errbuf, "Sending packets isn't supported on savefiles", + PCAP_ERRBUF_SIZE); + return (-1); +} + +/* + * Set direction flag: Which packets do we accept on a forwarding + * single device? IN, OUT or both? + */ +static int +sf_setdirection(pcap_t *p, pcap_direction_t d) +{ + snprintf(p->errbuf, sizeof(p->errbuf), + "Setting direction is not supported on savefiles"); + return (-1); +} + +static void +sf_cleanup(pcap_t *p) +{ + if (p->sf.rfile != stdin) + (void)fclose(p->sf.rfile); + if (p->buffer != NULL) + free(p->buffer); + pcap_freecode(&p->fcode); +} + +pcap_t * +pcap_open_offline(const char *fname, char *errbuf) +{ + FILE *fp; + pcap_t *p; + + if (fname[0] == '-' && fname[1] == '\0') + { + fp = stdin; +#if defined(WIN32) || defined(MSDOS) + /* + * We're reading from the standard input, so put it in binary + * mode, as savefiles are binary files. + */ + SET_BINMODE(fp); +#endif + } + else { +#if !defined(WIN32) && !defined(MSDOS) + fp = fopen(fname, "r"); +#else + fp = fopen(fname, "rb"); +#endif + if (fp == NULL) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", fname, + pcap_strerror(errno)); + return (NULL); + } + } + p = pcap_fopen_offline(fp, errbuf); + if (p == NULL) { + if (fp != stdin) + fclose(fp); + } + return (p); +} + +#ifdef WIN32 +pcap_t* pcap_hopen_offline(intptr_t osfd, char *errbuf) +{ + int fd; + FILE *file; + + fd = _open_osfhandle(osfd, _O_RDONLY); + if ( fd < 0 ) + { + snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno)); + return NULL; + } + + file = _fdopen(fd, "rb"); + if ( file == NULL ) + { + snprintf(errbuf, PCAP_ERRBUF_SIZE, pcap_strerror(errno)); + return NULL; + } + + return pcap_fopen_offline(file, errbuf); +} +#endif + +static int (*check_headers[])(pcap_t *, bpf_u_int32, FILE *, char *) = { + pcap_check_header, + pcap_ng_check_header +}; + +#define N_FILE_TYPES (sizeof check_headers / sizeof check_headers[0]) + +#ifdef WIN32 +static +#endif +pcap_t * +pcap_fopen_offline(FILE *fp, char *errbuf) +{ + register pcap_t *p; + bpf_u_int32 magic; + size_t amt_read; + u_int i; + + p = pcap_create_common("(savefile)", errbuf); + if (p == NULL) + return (NULL); + + /* + * Read the first 4 bytes of the file; the network analyzer dump + * file formats we support (pcap and pcap-ng), and several other + * formats we might support in the future (such as snoop, DOS and + * Windows Sniffer, and Microsoft Network Monitor) all have magic + * numbers that are unique in their first 4 bytes. + */ + amt_read = fread((char *)&magic, 1, sizeof(magic), fp); + if (amt_read != sizeof(magic)) { + if (ferror(fp)) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "error reading dump file: %s", + pcap_strerror(errno)); + } else { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "truncated dump file; tried to read %lu file header bytes, only got %lu", + (unsigned long)sizeof(magic), + (unsigned long)amt_read); + } + goto bad; + } + + /* + * Try all file types. + */ + for (i = 0; i < N_FILE_TYPES; i++) { + switch ((*check_headers[i])(p, magic, fp, errbuf)) { + + case -1: + /* + * Error trying to read the header. + */ + goto bad; + + case 1: + /* + * Yup, that's it. + */ + goto found; + } + } + + /* + * Well, who knows what this mess is.... + */ + snprintf(errbuf, PCAP_ERRBUF_SIZE, "unknown file format"); + goto bad; + +found: + p->sf.rfile = fp; + +#ifdef PCAP_FDDIPAD + /* Padding only needed for live capture fcode */ + p->fddipad = 0; +#endif + +#if !defined(WIN32) && !defined(MSDOS) + /* + * You can do "select()" and "poll()" on plain files on most + * platforms, and should be able to do so on pipes. + * + * You can't do "select()" on anything other than sockets in + * Windows, so, on Win32 systems, we don't have "selectable_fd". + */ + p->selectable_fd = fileno(fp); +#endif + + p->read_op = pcap_offline_read; + p->inject_op = sf_inject; + p->setfilter_op = install_bpf_program; + p->setdirection_op = sf_setdirection; + p->set_datalink_op = NULL; /* we don't support munging link-layer headers */ + p->getnonblock_op = sf_getnonblock; + p->setnonblock_op = sf_setnonblock; + p->stats_op = sf_stats; +#ifdef WIN32 + p->setbuff_op = sf_setbuff; + p->setmode_op = sf_setmode; + p->setmintocopy_op = sf_setmintocopy; +#endif + p->cleanup_op = sf_cleanup; + p->activated = 1; + + return (p); + bad: + free(p); + return (NULL); +} + +/* + * Read packets from a capture file, and call the callback for each + * packet. + * If cnt > 0, return after 'cnt' packets, otherwise continue until eof. + */ +int +pcap_offline_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) +{ + struct bpf_insn *fcode; + int status = 0; + int n = 0; + u_char *data; + + while (status == 0) { + struct pcap_pkthdr h; + + /* + * Has "pcap_breakloop()" been called? + * If so, return immediately - if we haven't read any + * packets, clear the flag and return -2 to indicate + * that we were told to break out of the loop, otherwise + * leave the flag set, so that the *next* call will break + * out of the loop without having read any packets, and + * return the number of packets we've processed so far. + */ + if (p->break_loop) { + if (n == 0) { + p->break_loop = 0; + return (-2); + } else + return (n); + } + + status = p->sf.next_packet_op(p, &h, &data); + if (status) { + if (status == 1) + return (0); + return (status); + } + + if ((fcode = p->fcode.bf_insns) == NULL || + bpf_filter(fcode, data, h.len, h.caplen)) { + (*callback)(user, &h, data); + if (++n >= cnt && cnt > 0) + break; + } + } + /*XXX this breaks semantics tcpslice expects */ + return (n); +} |