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-rw-r--r--savefile.c394
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+/*
+ * 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);
+}