1110 lines
27 KiB
C
1110 lines
27 KiB
C
/*
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* Copyright (c) 1993, 1994, 1995, 1996, 1997
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that: (1) source code distributions
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* retain the above copyright notice and this paragraph in its entirety, (2)
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* distributions including binary code include the above copyright notice and
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* this paragraph in its entirety in the documentation or other materials
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* provided with the distribution, and (3) all advertising materials mentioning
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* features or use of this software display the following acknowledgement:
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* ``This product includes software developed by the University of California,
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* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
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* the University nor the names of its contributors may be used to endorse
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* or promote products derived from this software without specific prior
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* written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*
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* sf-pcap-ng.c - pcap-ng-file-format-specific code from savefile.c
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*/
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#ifndef lint
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static const char rcsid[] _U_ =
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"@(#) $Header$ (LBL)";
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#endif
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#ifdef WIN32
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#include <pcap-stdinc.h>
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#else /* WIN32 */
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#if HAVE_INTTYPES_H
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#include <inttypes.h>
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#elif HAVE_STDINT_H
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#include <stdint.h>
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#endif
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#ifdef HAVE_SYS_BITYPES_H
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#include <sys/bitypes.h>
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#endif
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#include <sys/types.h>
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#endif /* WIN32 */
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#include <errno.h>
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#include <memory.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "pcap-int.h"
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#include "pcap-common.h"
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#ifdef HAVE_OS_PROTO_H
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#include "os-proto.h"
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#endif
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#include "sf-pcap-ng.h"
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/*
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* Block types.
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*/
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/*
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* Common part at the beginning of all blocks.
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*/
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struct block_header {
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bpf_u_int32 block_type;
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bpf_u_int32 total_length;
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};
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/*
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* Common trailer at the end of all blocks.
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*/
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struct block_trailer {
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bpf_u_int32 total_length;
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};
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/*
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* Common options.
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*/
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#define OPT_ENDOFOPT 0 /* end of options */
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#define OPT_COMMENT 1 /* comment string */
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/*
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* Option header.
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*/
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struct option_header {
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u_short option_code;
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u_short option_length;
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};
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/*
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* Structures for the part of each block type following the common
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* part.
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*/
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/*
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* Section Header Block.
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*/
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#define BT_SHB 0x0A0D0D0A
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struct section_header_block {
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bpf_u_int32 byte_order_magic;
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u_short major_version;
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u_short minor_version;
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u_int64_t section_length;
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/* followed by options and trailer */
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};
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/*
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* Byte-order magic value.
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*/
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#define BYTE_ORDER_MAGIC 0x1A2B3C4D
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/*
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* Current version number. If major_version isn't PCAP_NG_VERSION_MAJOR,
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* that means that this code can't read the file.
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*/
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#define PCAP_NG_VERSION_MAJOR 1
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/*
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* Interface Description Block.
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*/
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#define BT_IDB 0x00000001
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struct interface_description_block {
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u_short linktype;
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u_short reserved;
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bpf_u_int32 snaplen;
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/* followed by options and trailer */
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};
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/*
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* Options in the IDB.
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*/
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#define IF_NAME 2 /* interface name string */
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#define IF_DESCRIPTION 3 /* interface description string */
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#define IF_IPV4ADDR 4 /* interface's IPv4 address and netmask */
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#define IF_IPV6ADDR 5 /* interface's IPv6 address and prefix length */
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#define IF_MACADDR 6 /* interface's MAC address */
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#define IF_EUIADDR 7 /* interface's EUI address */
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#define IF_SPEED 8 /* interface's speed, in bits/s */
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#define IF_TSRESOL 9 /* interface's time stamp resolution */
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#define IF_TZONE 10 /* interface's time zone */
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#define IF_FILTER 11 /* filter used when capturing on interface */
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#define IF_OS 12 /* string OS on which capture on this interface was done */
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#define IF_FCSLEN 13 /* FCS length for this interface */
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#define IF_TSOFFSET 14 /* time stamp offset for this interface */
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/*
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* Enhanced Packet Block.
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*/
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#define BT_EPB 0x00000006
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struct enhanced_packet_block {
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bpf_u_int32 interface_id;
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bpf_u_int32 timestamp_high;
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bpf_u_int32 timestamp_low;
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bpf_u_int32 caplen;
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bpf_u_int32 len;
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/* followed by packet data, options, and trailer */
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};
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/*
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* Simple Packet Block.
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*/
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#define BT_SPB 0x00000003
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struct simple_packet_block {
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bpf_u_int32 len;
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/* followed by packet data and trailer */
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};
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/*
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* Packet Block.
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*/
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#define BT_PB 0x00000002
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struct packet_block {
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u_short interface_id;
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u_short drops_count;
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bpf_u_int32 timestamp_high;
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bpf_u_int32 timestamp_low;
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bpf_u_int32 caplen;
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bpf_u_int32 len;
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/* followed by packet data, options, and trailer */
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};
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/*
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* Block cursor - used when processing the contents of a block.
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* Contains a pointer into the data being processed and a count
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* of bytes remaining in the block.
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*/
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struct block_cursor {
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u_char *data;
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size_t data_remaining;
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bpf_u_int32 block_type;
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};
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static int pcap_ng_next_packet(pcap_t *p, struct pcap_pkthdr *hdr,
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u_char **data);
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static int
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read_bytes(FILE *fp, void *buf, size_t bytes_to_read, int fail_on_eof,
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char *errbuf)
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{
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size_t amt_read;
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amt_read = fread(buf, 1, bytes_to_read, fp);
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if (amt_read != bytes_to_read) {
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if (ferror(fp)) {
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"error reading dump file: %s",
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pcap_strerror(errno));
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} else {
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if (amt_read == 0 && !fail_on_eof)
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return (0); /* EOF */
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"truncated dump file; tried to read %lu bytes, only got %lu",
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(unsigned long)bytes_to_read,
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(unsigned long)amt_read);
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}
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return (-1);
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}
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return (1);
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}
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static int
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read_block(FILE *fp, pcap_t *p, struct block_cursor *cursor, char *errbuf)
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{
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int status;
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struct block_header bhdr;
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status = read_bytes(fp, &bhdr, sizeof(bhdr), 0, errbuf);
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if (status <= 0)
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return (status); /* error or EOF */
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if (p->sf.swapped) {
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bhdr.block_type = SWAPLONG(bhdr.block_type);
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bhdr.total_length = SWAPLONG(bhdr.total_length);
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}
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/*
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* Is this block "too big"?
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*
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* We choose 16MB as "too big", for now, so that we handle
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* "reasonably" large buffers but don't chew up all the
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* memory if we read a malformed file.
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*/
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if (bhdr.total_length > 16*1024*1024) {
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"pcap-ng block size %u > maximum %u",
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bhdr.total_length, 16*1024*1024);
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return (-1);
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}
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/*
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* Is this block "too small" - i.e., is it shorter than a block
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* header plus a block trailer?
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*/
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if (bhdr.total_length < sizeof(struct block_header) +
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sizeof(struct block_trailer)) {
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"block in pcap-ng dump file has a length of %u < %lu",
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bhdr.total_length,
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(unsigned long)(sizeof(struct block_header) + sizeof(struct block_trailer)));
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return (-1);
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}
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/*
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* Is the buffer big enough?
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*/
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if (p->bufsize < bhdr.total_length) {
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/*
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* No - make it big enough.
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*/
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p->buffer = realloc(p->buffer, bhdr.total_length);
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if (p->buffer == NULL) {
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snprintf(errbuf, PCAP_ERRBUF_SIZE, "out of memory");
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return (-1);
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}
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}
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/*
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* Copy the stuff we've read to the buffer, and read the rest
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* of the block.
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*/
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memcpy(p->buffer, &bhdr, sizeof(bhdr));
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if (read_bytes(fp, p->buffer + sizeof(bhdr),
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bhdr.total_length - sizeof(bhdr), 1, errbuf) == -1)
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return (-1);
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/*
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* Initialize the cursor.
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*/
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cursor->data = p->buffer + sizeof(bhdr);
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cursor->data_remaining = bhdr.total_length - sizeof(bhdr) -
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sizeof(struct block_trailer);
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cursor->block_type = bhdr.block_type;
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return (1);
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}
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static void *
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get_from_block_data(struct block_cursor *cursor, size_t chunk_size,
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char *errbuf)
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{
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void *data;
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/*
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* Make sure we have the specified amount of data remaining in
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* the block data.
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*/
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if (cursor->data_remaining < chunk_size) {
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"block of type %u in pcap-ng dump file is too short",
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cursor->block_type);
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return (NULL);
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}
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/*
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* Return the current pointer, and skip past the chunk.
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*/
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data = cursor->data;
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cursor->data += chunk_size;
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cursor->data_remaining -= chunk_size;
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return (data);
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}
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static struct option_header *
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get_opthdr_from_block_data(pcap_t *p, struct block_cursor *cursor, char *errbuf)
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{
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struct option_header *opthdr;
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opthdr = get_from_block_data(cursor, sizeof(*opthdr), errbuf);
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if (opthdr == NULL) {
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/*
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* Option header is cut short.
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*/
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return (NULL);
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}
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/*
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* Byte-swap it if necessary.
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*/
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if (p->sf.swapped) {
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opthdr->option_code = SWAPSHORT(opthdr->option_code);
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opthdr->option_length = SWAPSHORT(opthdr->option_length);
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}
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return (opthdr);
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}
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static void *
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get_optvalue_from_block_data(struct block_cursor *cursor,
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struct option_header *opthdr, char *errbuf)
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{
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size_t padded_option_len;
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void *optvalue;
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/* Pad option length to 4-byte boundary */
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padded_option_len = opthdr->option_length;
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padded_option_len = ((padded_option_len + 3)/4)*4;
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optvalue = get_from_block_data(cursor, padded_option_len, errbuf);
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if (optvalue == NULL) {
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/*
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* Option value is cut short.
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*/
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return (NULL);
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}
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return (optvalue);
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}
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static int
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process_idb_options(pcap_t *p, struct block_cursor *cursor, u_int *tsresol,
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u_int64_t *tsoffset, char *errbuf)
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{
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struct option_header *opthdr;
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void *optvalue;
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int saw_tsresol, saw_tsoffset;
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u_char tsresol_opt;
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u_int i;
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saw_tsresol = 0;
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saw_tsoffset = 0;
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while (cursor->data_remaining != 0) {
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/*
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* Get the option header.
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*/
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opthdr = get_opthdr_from_block_data(p, cursor, errbuf);
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if (opthdr == NULL) {
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/*
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* Option header is cut short.
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*/
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return (-1);
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}
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/*
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* Get option value.
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*/
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optvalue = get_optvalue_from_block_data(cursor, opthdr,
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errbuf);
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if (optvalue == NULL) {
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/*
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* Option value is cut short.
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*/
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return (-1);
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}
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switch (opthdr->option_code) {
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case OPT_ENDOFOPT:
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if (opthdr->option_length != 0) {
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"Interface Description Block has opt_endofopt option with length %u != 0",
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opthdr->option_length);
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return (-1);
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}
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goto done;
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case IF_TSRESOL:
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if (opthdr->option_length != 1) {
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"Interface Description Block has if_tsresol option with length %u != 1",
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opthdr->option_length);
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return (-1);
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}
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if (saw_tsresol) {
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"Interface Description Block has more than one if_tsresol option");
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return (-1);
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}
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saw_tsresol = 1;
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tsresol_opt = *(u_int *)optvalue;
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if (tsresol_opt & 0x80) {
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/*
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* Resolution is negative power of 2.
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*/
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*tsresol = 1 << (tsresol_opt & 0x7F);
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} else {
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/*
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* Resolution is negative power of 10.
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*/
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*tsresol = 1;
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for (i = 0; i < tsresol_opt; i++)
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*tsresol *= 10;
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}
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if (*tsresol == 0) {
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/*
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* Resolution is too high.
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*/
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if (tsresol_opt & 0x80) {
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"Interface Description Block if_tsresol option resolution 2^-%u is too high",
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tsresol_opt & 0x7F);
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} else {
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"Interface Description Block if_tsresol option resolution 10^-%u is too high",
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tsresol_opt);
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}
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return (-1);
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}
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break;
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case IF_TSOFFSET:
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if (opthdr->option_length != 8) {
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"Interface Description Block has if_tsoffset option with length %u != 8",
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opthdr->option_length);
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return (-1);
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}
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if (saw_tsoffset) {
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snprintf(errbuf, PCAP_ERRBUF_SIZE,
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"Interface Description Block has more than one if_tsoffset option");
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return (-1);
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}
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saw_tsoffset = 1;
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memcpy(tsoffset, optvalue, sizeof(*tsoffset));
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if (p->sf.swapped)
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*tsoffset = SWAPLL(*tsoffset);
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break;
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default:
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break;
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}
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}
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|
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done:
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return (0);
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}
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|
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/*
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* Check whether this is a pcap-ng savefile and, if it is, extract the
|
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* relevant information from the header.
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*/
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int
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pcap_ng_check_header(pcap_t *p, bpf_u_int32 magic, FILE *fp, char *errbuf)
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{
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size_t amt_read;
|
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bpf_u_int32 total_length;
|
|
bpf_u_int32 byte_order_magic;
|
|
struct block_header *bhdrp;
|
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struct section_header_block *shbp;
|
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int status;
|
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struct block_cursor cursor;
|
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struct interface_description_block *idbp;
|
|
|
|
/*
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|
* Check whether the first 4 bytes of the file are the block
|
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* type for a pcap-ng savefile.
|
|
*/
|
|
if (magic != BT_SHB) {
|
|
/*
|
|
* XXX - check whether this looks like what the block
|
|
* type would be after being munged by mapping between
|
|
* UN*X and DOS/Windows text file format and, if it
|
|
* does, look for the byte-order magic number in
|
|
* the appropriate place and, if we find it, report
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|
* this as possibly being a pcap-ng file transferred
|
|
* between UN*X and Windows in text file format?
|
|
*/
|
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return (0); /* nope */
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}
|
|
|
|
/*
|
|
* OK, they are. However, that's just \n\r\r\n, so it could,
|
|
* conceivably, be an ordinary text file.
|
|
*
|
|
* It could not, however, conceivably be any other type of
|
|
* capture file, so we can read the rest of the putative
|
|
* Section Header Block; put the block type in the common
|
|
* header, read the rest of the common header and the
|
|
* fixed-length portion of the SHB, and look for the byte-order
|
|
* magic value.
|
|
*/
|
|
amt_read = fread(&total_length, 1, sizeof(total_length), fp);
|
|
if (amt_read < sizeof(total_length)) {
|
|
if (ferror(fp)) {
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
|
"error reading dump file: %s",
|
|
pcap_strerror(errno));
|
|
return (-1); /* fail */
|
|
}
|
|
|
|
/*
|
|
* Possibly a weird short text file, so just say
|
|
* "not pcap-ng".
|
|
*/
|
|
return (0);
|
|
}
|
|
amt_read = fread(&byte_order_magic, 1, sizeof(byte_order_magic), fp);
|
|
if (amt_read < sizeof(byte_order_magic)) {
|
|
if (ferror(fp)) {
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
|
"error reading dump file: %s",
|
|
pcap_strerror(errno));
|
|
return (-1); /* fail */
|
|
}
|
|
|
|
/*
|
|
* Possibly a weird short text file, so just say
|
|
* "not pcap-ng".
|
|
*/
|
|
return (0);
|
|
}
|
|
if (byte_order_magic != BYTE_ORDER_MAGIC) {
|
|
byte_order_magic = SWAPLONG(byte_order_magic);
|
|
if (byte_order_magic != BYTE_ORDER_MAGIC) {
|
|
/*
|
|
* Not a pcap-ng file.
|
|
*/
|
|
return (0);
|
|
}
|
|
p->sf.swapped = 1;
|
|
total_length = SWAPLONG(total_length);
|
|
}
|
|
|
|
/*
|
|
* Check the sanity of the total length.
|
|
*/
|
|
if (total_length < sizeof(*bhdrp) + sizeof(*shbp) + sizeof(struct block_trailer)) {
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
|
"Section Header Block in pcap-ng dump file has a length of %u < %lu",
|
|
total_length,
|
|
(unsigned long)(sizeof(*bhdrp) + sizeof(*shbp) + sizeof(struct block_trailer)));
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* Allocate a buffer into which to read blocks. We default to
|
|
* the maximum of:
|
|
*
|
|
* the total length of the SHB for which we read the header;
|
|
*
|
|
* 2K, which should be more than large enough for an Enhanced
|
|
* Packet Block containing a full-size Ethernet frame, and
|
|
* leaving room for some options.
|
|
*
|
|
* If we find a bigger block, we reallocate the buffer.
|
|
*/
|
|
p->bufsize = 2048;
|
|
if (p->bufsize < total_length)
|
|
p->bufsize = total_length;
|
|
p->buffer = malloc(p->bufsize);
|
|
if (p->buffer == NULL) {
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE, "out of memory");
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* Copy the stuff we've read to the buffer, and read the rest
|
|
* of the SHB.
|
|
*/
|
|
bhdrp = (struct block_header *)p->buffer;
|
|
shbp = (struct section_header_block *)(p->buffer + sizeof(struct block_header));
|
|
bhdrp->block_type = magic;
|
|
bhdrp->total_length = total_length;
|
|
shbp->byte_order_magic = byte_order_magic;
|
|
if (read_bytes(fp,
|
|
p->buffer + (sizeof(magic) + sizeof(total_length) + sizeof(byte_order_magic)),
|
|
total_length - (sizeof(magic) + sizeof(total_length) + sizeof(byte_order_magic)),
|
|
1, errbuf) == -1)
|
|
goto fail;
|
|
|
|
if (p->sf.swapped) {
|
|
/*
|
|
* Byte-swap the fields we've read.
|
|
*/
|
|
shbp->major_version = SWAPSHORT(shbp->major_version);
|
|
shbp->minor_version = SWAPSHORT(shbp->minor_version);
|
|
|
|
/*
|
|
* XXX - we don't care about the section length.
|
|
*/
|
|
}
|
|
if (shbp->major_version != PCAP_NG_VERSION_MAJOR) {
|
|
snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
|
"unknown pcap-ng savefile major version number %u",
|
|
shbp->major_version);
|
|
goto fail;
|
|
}
|
|
p->sf.version_major = shbp->major_version;
|
|
p->sf.version_minor = shbp->minor_version;
|
|
|
|
/*
|
|
* Set the default time stamp resolution and offset.
|
|
*/
|
|
p->sf.tsresol = 1000000; /* microsecond resolution */
|
|
p->sf.tsscale = 1; /* multiply by 1 to scale to microseconds */
|
|
p->sf.tsoffset = 0; /* absolute timestamps */
|
|
|
|
/*
|
|
* Now start looking for an Interface Description Block.
|
|
*/
|
|
for (;;) {
|
|
/*
|
|
* Read the next block.
|
|
*/
|
|
status = read_block(fp, p, &cursor, errbuf);
|
|
if (status == 0) {
|
|
/* EOF - no IDB in this file */
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"the capture file has no Interface Description Blocks");
|
|
goto fail;
|
|
}
|
|
if (status == -1)
|
|
goto fail; /* error */
|
|
switch (cursor.block_type) {
|
|
|
|
case BT_IDB:
|
|
/*
|
|
* Get a pointer to the fixed-length portion of the
|
|
* IDB.
|
|
*/
|
|
idbp = get_from_block_data(&cursor, sizeof(*idbp),
|
|
errbuf);
|
|
if (idbp == NULL)
|
|
goto fail; /* error */
|
|
|
|
/*
|
|
* Byte-swap it if necessary.
|
|
*/
|
|
if (p->sf.swapped) {
|
|
idbp->linktype = SWAPSHORT(idbp->linktype);
|
|
idbp->snaplen = SWAPLONG(idbp->snaplen);
|
|
}
|
|
|
|
/*
|
|
* Count this interface.
|
|
*/
|
|
p->sf.ifcount++;
|
|
|
|
/*
|
|
* Now look for various time stamp options, so
|
|
* we know how to interpret the time stamps.
|
|
*/
|
|
if (process_idb_options(p, &cursor, &p->sf.tsresol,
|
|
&p->sf.tsoffset, errbuf) == -1)
|
|
goto fail;
|
|
|
|
/*
|
|
* Compute the scaling factor to convert the
|
|
* sub-second part of the time stamp to
|
|
* microseconds.
|
|
*/
|
|
if (p->sf.tsresol > 1000000) {
|
|
/*
|
|
* Higher than microsecond resolution;
|
|
* scale down to microseconds.
|
|
*/
|
|
p->sf.tsscale = (p->sf.tsresol / 1000000);
|
|
} else {
|
|
/*
|
|
* Lower than microsecond resolution;
|
|
* scale up to microseconds.
|
|
*/
|
|
p->sf.tsscale = (1000000 / p->sf.tsresol);
|
|
}
|
|
goto done;
|
|
|
|
case BT_EPB:
|
|
case BT_SPB:
|
|
case BT_PB:
|
|
/*
|
|
* Saw a packet before we saw any IDBs. That's
|
|
* not valid, as we don't know what link-layer
|
|
* encapsulation the packet has.
|
|
*/
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"the capture file has a packet block before any Interface Description Blocks");
|
|
goto fail;
|
|
|
|
default:
|
|
/*
|
|
* Just ignore it.
|
|
*/
|
|
break;
|
|
}
|
|
}
|
|
|
|
done:
|
|
p->tzoff = 0; /* XXX - not used in pcap */
|
|
p->snapshot = idbp->snaplen;
|
|
p->linktype = linktype_to_dlt(idbp->linktype);
|
|
p->linktype_ext = 0;
|
|
|
|
p->sf.next_packet_op = pcap_ng_next_packet;
|
|
|
|
return (1);
|
|
|
|
fail:
|
|
free(p->buffer);
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* Read and return the next packet from the savefile. Return the header
|
|
* in hdr and a pointer to the contents in data. Return 0 on success, 1
|
|
* if there were no more packets, and -1 on an error.
|
|
*/
|
|
static int
|
|
pcap_ng_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, u_char **data)
|
|
{
|
|
struct block_cursor cursor;
|
|
int status;
|
|
struct enhanced_packet_block *epbp;
|
|
struct simple_packet_block *spbp;
|
|
struct packet_block *pbp;
|
|
bpf_u_int32 interface_id = 0xFFFFFFFF;
|
|
struct interface_description_block *idbp;
|
|
struct section_header_block *shbp;
|
|
FILE *fp = p->sf.rfile;
|
|
u_int tsresol;
|
|
u_int64_t tsoffset;
|
|
u_int64_t t, sec, frac;
|
|
|
|
/*
|
|
* Look for an Enhanced Packet Block, a Simple Packet Block,
|
|
* or a Packet Block.
|
|
*/
|
|
for (;;) {
|
|
/*
|
|
* Read the block type and length; those are common
|
|
* to all blocks.
|
|
*/
|
|
status = read_block(fp, p, &cursor, p->errbuf);
|
|
if (status == 0)
|
|
return (1); /* EOF */
|
|
if (status == -1)
|
|
return (-1); /* error */
|
|
switch (cursor.block_type) {
|
|
|
|
case BT_EPB:
|
|
/*
|
|
* Get a pointer to the fixed-length portion of the
|
|
* EPB.
|
|
*/
|
|
epbp = get_from_block_data(&cursor, sizeof(*epbp),
|
|
p->errbuf);
|
|
if (epbp == NULL)
|
|
return (-1); /* error */
|
|
|
|
/*
|
|
* Byte-swap it if necessary.
|
|
*/
|
|
if (p->sf.swapped) {
|
|
/* these were written in opposite byte order */
|
|
interface_id = SWAPLONG(epbp->interface_id);
|
|
hdr->caplen = SWAPLONG(epbp->caplen);
|
|
hdr->len = SWAPLONG(epbp->len);
|
|
t = ((u_int64_t)SWAPLONG(epbp->timestamp_high)) << 32 |
|
|
SWAPLONG(epbp->timestamp_low);
|
|
} else {
|
|
interface_id = epbp->interface_id;
|
|
hdr->caplen = epbp->caplen;
|
|
hdr->len = epbp->len;
|
|
t = ((u_int64_t)epbp->timestamp_high) << 32 |
|
|
epbp->timestamp_low;
|
|
}
|
|
goto found;
|
|
|
|
case BT_SPB:
|
|
/*
|
|
* Get a pointer to the fixed-length portion of the
|
|
* SPB.
|
|
*/
|
|
spbp = get_from_block_data(&cursor, sizeof(*spbp),
|
|
p->errbuf);
|
|
if (spbp == NULL)
|
|
return (-1); /* error */
|
|
|
|
/*
|
|
* SPB packets are assumed to have arrived on
|
|
* the first interface.
|
|
*/
|
|
interface_id = 0;
|
|
|
|
/*
|
|
* Byte-swap it if necessary.
|
|
*/
|
|
if (p->sf.swapped) {
|
|
/* these were written in opposite byte order */
|
|
hdr->len = SWAPLONG(spbp->len);
|
|
} else
|
|
hdr->len = spbp->len;
|
|
|
|
/*
|
|
* The SPB doesn't give the captured length;
|
|
* it's the minimum of the snapshot length
|
|
* and the packet length.
|
|
*/
|
|
hdr->caplen = hdr->len;
|
|
if (hdr->caplen > p->snapshot)
|
|
hdr->caplen = p->snapshot;
|
|
t = 0; /* no time stamps */
|
|
goto found;
|
|
|
|
case BT_PB:
|
|
/*
|
|
* Get a pointer to the fixed-length portion of the
|
|
* PB.
|
|
*/
|
|
pbp = get_from_block_data(&cursor, sizeof(*pbp),
|
|
p->errbuf);
|
|
if (pbp == NULL)
|
|
return (-1); /* error */
|
|
|
|
/*
|
|
* Byte-swap it if necessary.
|
|
*/
|
|
if (p->sf.swapped) {
|
|
/* these were written in opposite byte order */
|
|
interface_id = SWAPSHORT(pbp->interface_id);
|
|
hdr->caplen = SWAPLONG(pbp->caplen);
|
|
hdr->len = SWAPLONG(pbp->len);
|
|
t = ((u_int64_t)SWAPLONG(pbp->timestamp_high)) << 32 |
|
|
SWAPLONG(pbp->timestamp_low);
|
|
} else {
|
|
interface_id = pbp->interface_id;
|
|
hdr->caplen = pbp->caplen;
|
|
hdr->len = pbp->len;
|
|
t = ((u_int64_t)pbp->timestamp_high) << 32 |
|
|
pbp->timestamp_low;
|
|
}
|
|
goto found;
|
|
|
|
case BT_IDB:
|
|
/*
|
|
* Interface Description Block. Get a pointer
|
|
* to its fixed-length portion.
|
|
*/
|
|
idbp = get_from_block_data(&cursor, sizeof(*idbp),
|
|
p->errbuf);
|
|
if (idbp == NULL)
|
|
return (-1); /* error */
|
|
|
|
/*
|
|
* Byte-swap it if necessary.
|
|
*/
|
|
if (p->sf.swapped) {
|
|
idbp->linktype = SWAPSHORT(idbp->linktype);
|
|
idbp->snaplen = SWAPLONG(idbp->snaplen);
|
|
}
|
|
|
|
/*
|
|
* If the link-layer type or snapshot length
|
|
* differ from the ones for the first IDB we
|
|
* saw, quit.
|
|
*
|
|
* XXX - just discard packets from those
|
|
* interfaces?
|
|
*/
|
|
if (p->linktype != idbp->linktype) {
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"an interface has a type %u different from the type of the first interface",
|
|
idbp->linktype);
|
|
return (-1);
|
|
}
|
|
if (p->snapshot != idbp->snaplen) {
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"an interface has a snapshot length %u different from the type of the first interface",
|
|
idbp->snaplen);
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* Count this interface.
|
|
*/
|
|
p->sf.ifcount++;
|
|
|
|
/*
|
|
* Set the default time stamp resolution and offset.
|
|
*/
|
|
tsresol = 1000000; /* microsecond resolution */
|
|
tsoffset = 0; /* absolute timestamps */
|
|
|
|
/*
|
|
* Now look for various time stamp options, to
|
|
* make sure they're the same.
|
|
*
|
|
* XXX - we could, in theory, handle multiple
|
|
* different resolutions and offsets, but we
|
|
* don't do so for now.
|
|
*/
|
|
if (process_idb_options(p, &cursor, &tsresol, &tsoffset,
|
|
p->errbuf) == -1)
|
|
return (-1);
|
|
if (tsresol != p->sf.tsresol) {
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"an interface has a time stamp resolution different from the time stamp resolution of the first interface");
|
|
return (-1);
|
|
}
|
|
if (tsoffset != p->sf.tsoffset) {
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"an interface has a time stamp offset different from the time stamp offset of the first interface");
|
|
return (-1);
|
|
}
|
|
break;
|
|
|
|
case BT_SHB:
|
|
/*
|
|
* Section Header Block. Get a pointer
|
|
* to its fixed-length portion.
|
|
*/
|
|
shbp = get_from_block_data(&cursor, sizeof(*shbp),
|
|
p->errbuf);
|
|
if (shbp == NULL)
|
|
return (-1); /* error */
|
|
|
|
/*
|
|
* Assume the byte order of this section is
|
|
* the same as that of the previous section.
|
|
* We'll check for that later.
|
|
*/
|
|
if (p->sf.swapped) {
|
|
shbp->byte_order_magic =
|
|
SWAPLONG(shbp->byte_order_magic);
|
|
shbp->major_version =
|
|
SWAPSHORT(shbp->major_version);
|
|
}
|
|
|
|
/*
|
|
* Make sure the byte order doesn't change;
|
|
* pcap_is_swapped() shouldn't change its
|
|
* return value in the middle of reading a capture.
|
|
*/
|
|
switch (shbp->byte_order_magic) {
|
|
|
|
case BYTE_ORDER_MAGIC:
|
|
/*
|
|
* OK.
|
|
*/
|
|
break;
|
|
|
|
case SWAPLONG(BYTE_ORDER_MAGIC):
|
|
/*
|
|
* Byte order changes.
|
|
*/
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"the file has sections with different byte orders");
|
|
return (-1);
|
|
|
|
default:
|
|
/*
|
|
* Not a valid SHB.
|
|
*/
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"the file has a section with a bad byte order magic field");
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* Make sure the major version is the version
|
|
* we handle.
|
|
*/
|
|
if (shbp->major_version != PCAP_NG_VERSION_MAJOR) {
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"unknown pcap-ng savefile major version number %u",
|
|
shbp->major_version);
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* Reset the interface count; this section should
|
|
* have its own set of IDBs. If any of them
|
|
* don't have the same interface type, snapshot
|
|
* length, or resolution as the first interface
|
|
* we saw, we'll fail. (And if we don't see
|
|
* any IDBs, we'll fail when we see a packet
|
|
* block.)
|
|
*/
|
|
p->sf.ifcount = 0;
|
|
break;
|
|
|
|
default:
|
|
/*
|
|
* Not a packet block, IDB, or SHB; ignore it.
|
|
*/
|
|
break;
|
|
}
|
|
}
|
|
|
|
found:
|
|
/*
|
|
* Is the interface ID an interface we know?
|
|
*/
|
|
if (interface_id >= p->sf.ifcount) {
|
|
/*
|
|
* Yes. Fail.
|
|
*/
|
|
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
|
|
"a packet arrived on interface %u, but there's no Interface Description Block for that interface",
|
|
interface_id);
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* Convert the time stamp to a struct timeval.
|
|
*/
|
|
sec = t / p->sf.tsresol + p->sf.tsoffset;
|
|
frac = t % p->sf.tsresol;
|
|
if (p->sf.tsresol > 1000000) {
|
|
/*
|
|
* Higher than microsecond resolution; scale down to
|
|
* microseconds.
|
|
*/
|
|
frac /= p->sf.tsscale;
|
|
} else {
|
|
/*
|
|
* Lower than microsecond resolution; scale up to
|
|
* microseconds.
|
|
*/
|
|
frac *= p->sf.tsscale;
|
|
}
|
|
hdr->ts.tv_sec = sec;
|
|
hdr->ts.tv_usec = frac;
|
|
|
|
/*
|
|
* Get a pointer to the packet data.
|
|
*/
|
|
*data = get_from_block_data(&cursor, hdr->caplen, p->errbuf);
|
|
if (*data == NULL)
|
|
return (-1);
|
|
|
|
if (p->sf.swapped) {
|
|
/*
|
|
* Convert pseudo-headers from the byte order of
|
|
* the host on which the file was saved to our
|
|
* byte order, as necessary.
|
|
*/
|
|
switch (p->linktype) {
|
|
|
|
case DLT_USB_LINUX:
|
|
swap_linux_usb_header(hdr, *data, 0);
|
|
break;
|
|
|
|
case DLT_USB_LINUX_MMAPPED:
|
|
swap_linux_usb_header(hdr, *data, 1);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return (0);
|
|
}
|