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NetBSD/lib/libpcap/savefile.c

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/* $NetBSD: savefile.c,v 1.8 2004/09/27 23:02:53 dyoung Exp $ */
/*
* 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.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static const char rcsid[] =
"@(#) Header: /tcpdump/master/libpcap/savefile.c,v 1.92.2.11 2004/03/11 23:46:14 guy Exp (LBL)";
#else
__RCSID("$NetBSD: savefile.c,v 1.8 2004/09/27 23:02:53 dyoung Exp $");
#endif
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <errno.h>
#include <memory.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pcap-int.h"
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
#define TCPDUMP_MAGIC 0xa1b2c3d4
#define PATCHED_TCPDUMP_MAGIC 0xa1b2cd34
/*
* We use the "receiver-makes-right" approach to byte order,
* because time is at a premium when we are writing the file.
* In other words, the pcap_file_header and pcap_pkthdr,
* records are written in host byte order.
* Note that the bytes of packet data are written out in the order in
* which they were received, so multi-byte fields in packets are not
* written in host byte order, they're written in whatever order the
* sending machine put them in.
*
* ntoh[ls] aren't sufficient because we might need to swap on a big-endian
* machine (if the file was written in little-end order).
*/
#define SWAPLONG(y) \
((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
#define SWAPSHORT(y) \
( (((y)&0xff)<<8) | ((u_short)((y)&0xff00)>>8) )
#define SFERR_TRUNC 1
#define SFERR_BADVERSION 2
#define SFERR_BADF 3
#define SFERR_EOF 4 /* not really an error, just a status */
/*
* We don't write DLT_* values to the capture file header, because
* they're not the same on all platforms.
*
* Unfortunately, the various flavors of BSD have not always used the same
* numerical values for the same data types, and various patches to
* libpcap for non-BSD OSes have added their own DLT_* codes for link
* layer encapsulation types seen on those OSes, and those codes have had,
* in some cases, values that were also used, on other platforms, for other
* link layer encapsulation types.
*
* This means that capture files of a type whose numerical DLT_* code
* means different things on different BSDs, or with different versions
* of libpcap, can't always be read on systems other than those like
* the one running on the machine on which the capture was made.
*
* Instead, we define here a set of LINKTYPE_* codes, and map DLT_* codes
* to LINKTYPE_* codes when writing a savefile header, and map LINKTYPE_*
* codes to DLT_* codes when reading a savefile header.
*
* For those DLT_* codes that have, as far as we know, the same values on
* all platforms (DLT_NULL through DLT_FDDI), we define LINKTYPE_xxx as
* DLT_xxx; that way, captures of those types can still be read by
* versions of libpcap that map LINKTYPE_* values to DLT_* values, and
* captures of those types written by versions of libpcap that map DLT_
* values to LINKTYPE_ values can still be read by older versions
* of libpcap.
*
* The other LINKTYPE_* codes are given values starting at 100, in the
* hopes that no DLT_* code will be given one of those values.
*
* In order to ensure that a given LINKTYPE_* code's value will refer to
* the same encapsulation type on all platforms, you should not allocate
* a new LINKTYPE_* value without consulting "tcpdump-workers@tcpdump.org".
* The tcpdump developers will allocate a value for you, and will not
* subsequently allocate it to anybody else; that value will be added to
* the "pcap.h" in the tcpdump.org CVS repository, so that a future
* libpcap release will include it.
*
* You should, if possible, also contribute patches to libpcap and tcpdump
* to handle the new encapsulation type, so that they can also be checked
* into the tcpdump.org CVS repository and so that they will appear in
* future libpcap and tcpdump releases.
*
* Do *NOT* assume that any values after the largest value in this file
* are available; you might not have the most up-to-date version of this
* file, and new values after that one might have been assigned. Also,
* do *NOT* use any values below 100 - those might already have been
* taken by one (or more!) organizations.
*/
#define LINKTYPE_NULL DLT_NULL
#define LINKTYPE_ETHERNET DLT_EN10MB /* also for 100Mb and up */
#define LINKTYPE_EXP_ETHERNET DLT_EN3MB /* 3Mb experimental Ethernet */
#define LINKTYPE_AX25 DLT_AX25
#define LINKTYPE_PRONET DLT_PRONET
#define LINKTYPE_CHAOS DLT_CHAOS
#define LINKTYPE_TOKEN_RING DLT_IEEE802 /* DLT_IEEE802 is used for Token Ring */
#define LINKTYPE_ARCNET DLT_ARCNET /* BSD-style headers */
#define LINKTYPE_SLIP DLT_SLIP
#define LINKTYPE_PPP DLT_PPP
#define LINKTYPE_FDDI DLT_FDDI
/*
* LINKTYPE_PPP is for use when there might, or might not, be an RFC 1662
* PPP in HDLC-like framing header (with 0xff 0x03 before the PPP protocol
* field) at the beginning of the packet.
*
* This is for use when there is always such a header; the address field
* might be 0xff, for regular PPP, or it might be an address field for Cisco
* point-to-point with HDLC framing as per section 4.3.1 of RFC 1547 ("Cisco
* HDLC"). This is, for example, what you get with NetBSD's DLT_PPP_SERIAL.
*
* We give it the same value as NetBSD's DLT_PPP_SERIAL, in the hopes that
* nobody else will choose a DLT_ value of 50, and so that DLT_PPP_SERIAL
* captures will be written out with a link type that NetBSD's tcpdump
* can read.
*/
#define LINKTYPE_PPP_HDLC 50 /* PPP in HDLC-like framing */
#define LINKTYPE_PPP_ETHER 51 /* NetBSD PPP-over-Ethernet */
/*
* This isn't supported in libpcap 0.8[.x], but is supported in the
* current CVS version; we include it here to note that it's not available
* for anybody else to use.
*/
#define LINKTYPE_SYMANTEC_FIREWALL 99 /* Symantec Enterprise Firewall */
#define LINKTYPE_ATM_RFC1483 100 /* LLC/SNAP-encapsulated ATM */
#define LINKTYPE_RAW 101 /* raw IP */
#define LINKTYPE_SLIP_BSDOS 102 /* BSD/OS SLIP BPF header */
#define LINKTYPE_PPP_BSDOS 103 /* BSD/OS PPP BPF header */
#define LINKTYPE_C_HDLC 104 /* Cisco HDLC */
#define LINKTYPE_IEEE802_11 105 /* IEEE 802.11 (wireless) */
#define LINKTYPE_ATM_CLIP 106 /* Linux Classical IP over ATM */
#define LINKTYPE_FRELAY 107 /* Frame Relay */
#define LINKTYPE_LOOP 108 /* OpenBSD loopback */
#define LINKTYPE_ENC 109 /* OpenBSD IPSEC enc */
/*
* These three types are reserved for future use.
*/
#define LINKTYPE_LANE8023 110 /* ATM LANE + 802.3 */
#define LINKTYPE_HIPPI 111 /* NetBSD HIPPI */
#define LINKTYPE_HDLC 112 /* NetBSD HDLC framing */
#define LINKTYPE_LINUX_SLL 113 /* Linux cooked socket capture */
#define LINKTYPE_LTALK 114 /* Apple LocalTalk hardware */
#define LINKTYPE_ECONET 115 /* Acorn Econet */
/*
* Reserved for use with OpenBSD ipfilter.
*/
#define LINKTYPE_IPFILTER 116
#define LINKTYPE_PFLOG 117 /* OpenBSD DLT_PFLOG */
#define LINKTYPE_CISCO_IOS 118 /* For Cisco-internal use */
#define LINKTYPE_PRISM_HEADER 119 /* 802.11+Prism II monitor mode */
#define LINKTYPE_AIRONET_HEADER 120 /* FreeBSD Aironet driver stuff */
/*
* Reserved for Siemens HiPath HDLC.
*/
#define LINKTYPE_HHDLC 121
#define LINKTYPE_IP_OVER_FC 122 /* RFC 2625 IP-over-Fibre Channel */
#define LINKTYPE_SUNATM 123 /* Solaris+SunATM */
/*
* Reserved as per request from Kent Dahlgren <kent@praesum.com>
* for private use.
*/
#define LINKTYPE_RIO 124 /* RapidIO */
#define LINKTYPE_PCI_EXP 125 /* PCI Express */
#define LINKTYPE_AURORA 126 /* Xilinx Aurora link layer */
#define LINKTYPE_IEEE802_11_RADIO 127 /* 802.11 plus BSD radio header */
/*
* Reserved for the TZSP encapsulation, as per request from
* Chris Waters <chris.waters@networkchemistry.com>
* TZSP is a generic encapsulation for any other link type,
* which includes a means to include meta-information
* with the packet, e.g. signal strength and channel
* for 802.11 packets.
*/
#define LINKTYPE_TZSP 128 /* Tazmen Sniffer Protocol */
#define LINKTYPE_ARCNET_LINUX 129 /* Linux-style headers */
/*
* Juniper-private data link types, as per request from
* Hannes Gredler <hannes@juniper.net>. The corresponding
* DLT_s are used for passing on chassis-internal
* metainformation such as QOS profiles, etc..
*/
#define LINKTYPE_JUNIPER_MLPPP 130
#define LINKTYPE_JUNIPER_MLFR 131
#define LINKTYPE_JUNIPER_ES 132
#define LINKTYPE_JUNIPER_GGSN 133
#define LINKTYPE_JUNIPER_MFR 134
#define LINKTYPE_JUNIPER_ATM2 135
#define LINKTYPE_JUNIPER_SERVICES 136
#define LINKTYPE_JUNIPER_ATM1 137
#define LINKTYPE_APPLE_IP_OVER_IEEE1394 138 /* Apple IP-over-IEEE 1394 cooked header */
#define LINKTYPE_RAWSS7 139 /* see rawss7.h for */
#define LINKTYPE_RAWSS7_MTP2 140 /* information on these */
#define LINKTYPE_RAWSS7_MTP3 141 /* definitions */
#define LINKTYPE_RAWSS7_SCCP 142
/*
* This isn't supported in libpcap 0.8[.x], but is supported in the
* current CVS version; we include it here to note that it's not available
* for anybody else to use.
*/
#define LINKTYPE_DOCSIS 143 /* DOCSIS MAC frames */
#define LINKTYPE_LINUX_IRDA 144 /* Linux-IrDA */
/*
* Reserved for IBM SP switch and IBM Next Federation switch.
*/
#define LINKTYPE_IBM_SP 145
#define LINKTYPE_IBM_SN 146
/*
* Reserved for private use. If you have some link-layer header type
* that you want to use within your organization, with the capture files
* using that link-layer header type not ever be sent outside your
* organization, you can use these values.
*
* No libpcap release will use these for any purpose, nor will any
* tcpdump release use them, either.
*
* Do *NOT* use these in capture files that you expect anybody not using
* your private versions of capture-file-reading tools to read; in
* particular, do *NOT* use them in products, otherwise you may find that
* people won't be able to use tcpdump, or snort, or Ethereal, or... to
* read capture files from your firewall/intrusion detection/traffic
* monitoring/etc. appliance, or whatever product uses that LINKTYPE_ value,
* and you may also find that the developers of those applications will
* not accept patches to let them read those files.
*
* Also, do not use them if somebody might send you a capture using them
* for *their* private type and tools using them for *your* private type
* would have to read them.
*
* Instead, in those cases, ask "tcpdump-workers@tcpdump.org" for a new DLT_
* and LINKTYPE_ value, as per the comment in pcap-bpf.h, and use the type
* you're given.
*/
#define LINKTYPE_USER0 147
#define LINKTYPE_USER1 148
#define LINKTYPE_USER2 149
#define LINKTYPE_USER3 150
#define LINKTYPE_USER4 151
#define LINKTYPE_USER5 152
#define LINKTYPE_USER6 153
#define LINKTYPE_USER7 154
#define LINKTYPE_USER8 155
#define LINKTYPE_USER9 156
#define LINKTYPE_USER10 157
#define LINKTYPE_USER11 158
#define LINKTYPE_USER12 159
#define LINKTYPE_USER13 160
#define LINKTYPE_USER14 161
#define LINKTYPE_USER15 162
/*
* For future use with 802.11 captures - defined by AbsoluteValue
* Systems to store a number of bits of link-layer information
* including radio information:
*
* http://www.shaftnet.org/~pizza/software/capturefrm.txt
*
* but could and arguably should also be used by non-AVS Linux
* 802.11 drivers; that may happen in the future.
*/
#define LINKTYPE_IEEE802_11_RADIO_AVS 163 /* 802.11 plus AVS radio header */
/*
* Juniper-private data link type, as per request from
* Hannes Gredler <hannes@juniper.net>. The corresponding
* DLT_s are used for passing on chassis-internal
* metainformation such as QOS profiles, etc..
*/
#define LINKTYPE_JUNIPER_MONITOR 164
static struct linktype_map {
int dlt;
int linktype;
} map[] = {
/*
* These DLT_* codes have LINKTYPE_* codes with values identical
* to the values of the corresponding DLT_* code.
*/
{ DLT_NULL, LINKTYPE_NULL },
{ DLT_EN10MB, LINKTYPE_ETHERNET },
{ DLT_EN3MB, LINKTYPE_EXP_ETHERNET },
{ DLT_AX25, LINKTYPE_AX25 },
{ DLT_PRONET, LINKTYPE_PRONET },
{ DLT_CHAOS, LINKTYPE_CHAOS },
{ DLT_IEEE802, LINKTYPE_TOKEN_RING },
{ DLT_ARCNET, LINKTYPE_ARCNET },
{ DLT_SLIP, LINKTYPE_SLIP },
{ DLT_PPP, LINKTYPE_PPP },
{ DLT_FDDI, LINKTYPE_FDDI },
/*
* These DLT_* codes have different values on different
* platforms; we map them to LINKTYPE_* codes that
* have values that should never be equal to any DLT_*
* code.
*/
#ifdef DLT_FR
/* BSD/OS Frame Relay */
{ DLT_FR, LINKTYPE_FRELAY },
#endif
{ DLT_SYMANTEC_FIREWALL, LINKTYPE_SYMANTEC_FIREWALL },
{ DLT_ATM_RFC1483, LINKTYPE_ATM_RFC1483 },
{ DLT_RAW, LINKTYPE_RAW },
{ DLT_SLIP_BSDOS, LINKTYPE_SLIP_BSDOS },
{ DLT_PPP_BSDOS, LINKTYPE_PPP_BSDOS },
/* BSD/OS Cisco HDLC */
{ DLT_C_HDLC, LINKTYPE_C_HDLC },
/*
* These DLT_* codes are not on all platforms, but, so far,
* there don't appear to be any platforms that define
* other codes with those values; we map them to
* different LINKTYPE_* values anyway, just in case.
*/
/* Linux ATM Classical IP */
{ DLT_ATM_CLIP, LINKTYPE_ATM_CLIP },
/* NetBSD sync/async serial PPP (or Cisco HDLC) */
{ DLT_PPP_SERIAL, LINKTYPE_PPP_HDLC },
/* NetBSD PPP over Ethernet */
{ DLT_PPP_ETHER, LINKTYPE_PPP_ETHER },
/* IEEE 802.11 wireless */
{ DLT_IEEE802_11, LINKTYPE_IEEE802_11 },
/* Frame Relay */
{ DLT_FRELAY, LINKTYPE_FRELAY },
/* OpenBSD loopback */
{ DLT_LOOP, LINKTYPE_LOOP },
/* Linux cooked socket capture */
{ DLT_LINUX_SLL, LINKTYPE_LINUX_SLL },
/* Apple LocalTalk hardware */
{ DLT_LTALK, LINKTYPE_LTALK },
/* Acorn Econet */
{ DLT_ECONET, LINKTYPE_ECONET },
/* OpenBSD DLT_PFLOG */
{ DLT_PFLOG, LINKTYPE_PFLOG },
/* For Cisco-internal use */
{ DLT_CISCO_IOS, LINKTYPE_CISCO_IOS },
/* Prism II monitor-mode header plus 802.11 header */
{ DLT_PRISM_HEADER, LINKTYPE_PRISM_HEADER },
/* FreeBSD Aironet driver stuff */
{ DLT_AIRONET_HEADER, LINKTYPE_AIRONET_HEADER },
/* Siemens HiPath HDLC */
{ DLT_HHDLC, LINKTYPE_HHDLC },
/* RFC 2625 IP-over-Fibre Channel */
{ DLT_IP_OVER_FC, LINKTYPE_IP_OVER_FC },
/* Solaris+SunATM */
{ DLT_SUNATM, LINKTYPE_SUNATM },
/* RapidIO */
{ DLT_RIO, LINKTYPE_RIO },
/* PCI Express */
{ DLT_PCI_EXP, LINKTYPE_PCI_EXP },
/* Xilinx Aurora link layer */
{ DLT_AURORA, LINKTYPE_AURORA },
/* 802.11 plus BSD radio header */
{ DLT_IEEE802_11_RADIO, LINKTYPE_IEEE802_11_RADIO },
/* Tazmen Sniffer Protocol */
{ DLT_TZSP, LINKTYPE_TZSP },
/* Arcnet with Linux-style link-layer headers */
{ DLT_ARCNET_LINUX, LINKTYPE_ARCNET_LINUX },
/* Juniper-internal chassis encapsulation */
{ DLT_JUNIPER_MLPPP, LINKTYPE_JUNIPER_MLPPP },
{ DLT_JUNIPER_MLFR, LINKTYPE_JUNIPER_MLFR },
{ DLT_JUNIPER_ES, LINKTYPE_JUNIPER_ES },
{ DLT_JUNIPER_GGSN, LINKTYPE_JUNIPER_GGSN },
{ DLT_JUNIPER_MFR, LINKTYPE_JUNIPER_MFR },
{ DLT_JUNIPER_ATM2, LINKTYPE_JUNIPER_ATM2 },
{ DLT_JUNIPER_SERVICES, LINKTYPE_JUNIPER_SERVICES },
{ DLT_JUNIPER_ATM1, LINKTYPE_JUNIPER_ATM1 },
/* Apple IP-over-IEEE 1394 cooked header */
{ DLT_APPLE_IP_OVER_IEEE1394, LINKTYPE_APPLE_IP_OVER_IEEE1394 },
/* DOCSIS MAC frames */
{ DLT_DOCSIS, LINKTYPE_DOCSIS },
/* IrDA IrLAP packets + Linux-cooked header */
{ DLT_LINUX_IRDA, LINKTYPE_LINUX_IRDA },
/* IBM SP and Next Federation switches */
{ DLT_IBM_SP, LINKTYPE_IBM_SP },
{ DLT_IBM_SN, LINKTYPE_IBM_SN },
/* 802.11 plus AVS radio header */
{ DLT_IEEE802_11_RADIO_AVS, LINKTYPE_IEEE802_11_RADIO_AVS },
/*
* Any platform that defines additional DLT_* codes should:
*
* request a LINKTYPE_* code and value from tcpdump.org,
* as per the above;
*
* add, in their version of libpcap, an entry to map
* those DLT_* codes to the corresponding LINKTYPE_*
* code;
*
* redefine, in their "net/bpf.h", any DLT_* values
* that collide with the values used by their additional
* DLT_* codes, to remove those collisions (but without
* making them collide with any of the LINKTYPE_*
* values equal to 50 or above; they should also avoid
* defining DLT_* values that collide with those
* LINKTYPE_* values, either).
*/
/* Juniper-internal chassis encapsulation */
{ DLT_JUNIPER_MONITOR, LINKTYPE_JUNIPER_MONITOR },
{ -1, -1 }
};
static int
dlt_to_linktype(int dlt)
{
int i;
for (i = 0; map[i].dlt != -1; i++) {
if (map[i].dlt == dlt)
return (map[i].linktype);
}
/*
* If we don't have a mapping for this DLT_ code, return an
* error; that means that the table above needs to have an
* entry added.
*/
return (-1);
}
static int
linktype_to_dlt(int linktype)
{
int i;
for (i = 0; map[i].linktype != -1; i++) {
if (map[i].linktype == linktype)
return (map[i].dlt);
}
/*
* If we don't have an entry for this link type, return
* the link type value; it may be a DLT_ value from an
* older version of libpcap.
*/
return linktype;
}
static int
sf_write_header(FILE *fp, int linktype, int thiszone, int snaplen)
{
struct pcap_file_header hdr;
hdr.magic = TCPDUMP_MAGIC;
hdr.version_major = PCAP_VERSION_MAJOR;
hdr.version_minor = PCAP_VERSION_MINOR;
hdr.thiszone = thiszone;
hdr.snaplen = snaplen;
hdr.sigfigs = 0;
hdr.linktype = linktype;
if (fwrite((char *)&hdr, sizeof(hdr), 1, fp) != 1)
return (-1);
return (0);
}
static void
swap_hdr(struct pcap_file_header *hp)
{
hp->version_major = SWAPSHORT(hp->version_major);
hp->version_minor = SWAPSHORT(hp->version_minor);
hp->thiszone = SWAPLONG(hp->thiszone);
hp->sigfigs = SWAPLONG(hp->sigfigs);
hp->snaplen = SWAPLONG(hp->snaplen);
hp->linktype = SWAPLONG(hp->linktype);
}
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 ignore
* requests to put it in non-blocking mode.
*/
return (0);
}
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);
}
static void
sf_close(pcap_t *p)
{
if (p->sf.rfile != stdin)
(void)fclose(p->sf.rfile);
if (p->sf.base != NULL)
free(p->sf.base);
}
pcap_t *
pcap_open_offline(const char *fname, char *errbuf)
{
register pcap_t *p;
register FILE *fp;
struct pcap_file_header hdr;
bpf_u_int32 magic;
int linklen;
p = (pcap_t *)malloc(sizeof(*p));
if (p == NULL) {
strlcpy(errbuf, "out of swap", PCAP_ERRBUF_SIZE);
return (NULL);
}
memset((char *)p, 0, sizeof(*p));
if (fname[0] == '-' && fname[1] == '\0')
fp = stdin;
else {
#ifndef WIN32
fp = fopen(fname, "r");
#else
fp = fopen(fname, "rb");
#endif
if (fp == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s",
fname, pcap_strerror(errno));
goto bad;
}
}
if (fread((char *)&hdr, sizeof(hdr), 1, fp) != 1) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "fread: %s",
pcap_strerror(errno));
goto bad;
}
magic = hdr.magic;
if (magic != TCPDUMP_MAGIC && magic != PATCHED_TCPDUMP_MAGIC) {
magic = SWAPLONG(magic);
if (magic != TCPDUMP_MAGIC && magic != PATCHED_TCPDUMP_MAGIC) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"bad dump file format");
goto bad;
}
p->sf.swapped = 1;
swap_hdr(&hdr);
}
if (magic == PATCHED_TCPDUMP_MAGIC) {
/*
* XXX - the patch that's in some versions of libpcap
* changes the packet header but not the magic number;
* we'd have to use some hacks^H^H^H^H^Hheuristics to
* detect that.
*/
p->sf.hdrsize = sizeof(struct pcap_sf_patched_pkthdr);
} else
p->sf.hdrsize = sizeof(struct pcap_sf_pkthdr);
if (hdr.version_major < PCAP_VERSION_MAJOR) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "archaic file format");
goto bad;
}
p->tzoff = hdr.thiszone;
p->snapshot = hdr.snaplen;
p->linktype = linktype_to_dlt(hdr.linktype);
p->sf.rfile = fp;
#ifndef WIN32
p->bufsize = hdr.snaplen;
#else
/* Allocate the space for pcap_pkthdr as well. It will be used by pcap_read_ex */
p->bufsize = hdr.snaplen+sizeof(struct pcap_pkthdr);
#endif
/* Align link header as required for proper data alignment */
/* XXX should handle all types */
switch (p->linktype) {
case DLT_EN10MB:
linklen = 14;
break;
case DLT_FDDI:
linklen = 13 + 8; /* fddi_header + llc */
break;
case DLT_NULL:
default:
linklen = 0;
break;
}
if (p->bufsize < 0)
p->bufsize = BPF_MAXBUFSIZE;
p->sf.base = (u_char *)malloc(p->bufsize + BPF_ALIGNMENT);
if (p->sf.base == NULL) {
strlcpy(errbuf, "out of swap", PCAP_ERRBUF_SIZE);
goto bad;
}
p->buffer = p->sf.base + BPF_ALIGNMENT - (linklen % BPF_ALIGNMENT);
p->sf.version_major = hdr.version_major;
p->sf.version_minor = hdr.version_minor;
#ifdef PCAP_FDDIPAD
/* XXX padding only needed for kernel fcode */
pcap_fddipad = 0;
#endif
/*
* We interchanged the caplen and len fields at version 2.3,
* in order to match the bpf header layout. But unfortunately
* some files were written with version 2.3 in their headers
* but without the interchanged fields.
*
* In addition, DG/UX tcpdump writes out files with a version
* number of 543.0, and with the caplen and len fields in the
* pre-2.3 order.
*/
switch (hdr.version_major) {
case 2:
if (hdr.version_minor < 3)
p->sf.lengths_swapped = SWAPPED;
else if (hdr.version_minor == 3)
p->sf.lengths_swapped = MAYBE_SWAPPED;
else
p->sf.lengths_swapped = NOT_SWAPPED;
break;
case 543:
p->sf.lengths_swapped = SWAPPED;
break;
default:
p->sf.lengths_swapped = NOT_SWAPPED;
break;
}
#ifndef WIN32
/*
* 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->setfilter_op = install_bpf_program;
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;
p->close_op = sf_close;
return (p);
bad:
if(fp)
fclose(fp);
free(p);
return (NULL);
}
/*
* Read sf_readfile and return the next packet. Return the header in hdr
* and the contents in buf. Return 0 on success, SFERR_EOF if there were
* no more packets, and SFERR_TRUNC if a partial packet was encountered.
*/
static int
sf_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, u_char *buf, u_int buflen)
{
struct pcap_sf_patched_pkthdr sf_hdr;
FILE *fp = p->sf.rfile;
size_t amt_read;
bpf_u_int32 t;
/*
* Read the packet header; the structure we use as a buffer
* is the longer structure for files generated by the patched
* libpcap, but if the file has the magic number for an
* unpatched libpcap we only read as many bytes as the regular
* header has.
*/
amt_read = fread(&sf_hdr, 1, p->sf.hdrsize, fp);
if (amt_read != p->sf.hdrsize) {
if (ferror(fp)) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"error reading dump file: %s",
pcap_strerror(errno));
return (-1);
} else {
if (amt_read != 0) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"truncated dump file; tried to read %d header bytes, only got %lu",
p->sf.hdrsize, (unsigned long)amt_read);
return (-1);
}
/* EOF */
return (1);
}
}
if (p->sf.swapped) {
/* these were written in opposite byte order */
hdr->caplen = SWAPLONG(sf_hdr.caplen);
hdr->len = SWAPLONG(sf_hdr.len);
hdr->ts.tv_sec = SWAPLONG(sf_hdr.ts.tv_sec);
hdr->ts.tv_usec = SWAPLONG(sf_hdr.ts.tv_usec);
} else {
hdr->caplen = sf_hdr.caplen;
hdr->len = sf_hdr.len;
hdr->ts.tv_sec = sf_hdr.ts.tv_sec;
hdr->ts.tv_usec = sf_hdr.ts.tv_usec;
}
/* Swap the caplen and len fields, if necessary. */
switch (p->sf.lengths_swapped) {
case NOT_SWAPPED:
break;
case MAYBE_SWAPPED:
if (hdr->caplen <= hdr->len) {
/*
* The captured length is <= the actual length,
* so presumably they weren't swapped.
*/
break;
}
/* FALLTHROUGH */
case SWAPPED:
t = hdr->caplen;
hdr->caplen = hdr->len;
hdr->len = t;
break;
}
if (hdr->caplen > buflen) {
/*
* This can happen due to Solaris 2.3 systems tripping
* over the BUFMOD problem and not setting the snapshot
* correctly in the savefile header. If the caplen isn't
* grossly wrong, try to salvage.
*/
static u_char *tp = NULL;
static size_t tsize = 0;
if (hdr->caplen > 65535) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"bogus savefile header");
return (-1);
}
if (tsize < hdr->caplen) {
tsize = ((hdr->caplen + 1023) / 1024) * 1024;
if (tp != NULL)
free((u_char *)tp);
tp = (u_char *)malloc(tsize);
if (tp == NULL) {
tsize = 0;
(void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"BUFMOD hack malloc");
return (-1);
}
}
amt_read = fread((char *)tp, 1, hdr->caplen, fp);
if (amt_read != hdr->caplen) {
if (ferror(fp)) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"error reading dump file: %s",
pcap_strerror(errno));
} else {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"truncated dump file; tried to read %u captured bytes, only got %lu",
hdr->caplen, (unsigned long)amt_read);
}
return (-1);
}
/*
* We can only keep up to buflen bytes. Since caplen > buflen
* is exactly how we got here, we know we can only keep the
* first buflen bytes and must drop the remainder. Adjust
* caplen accordingly, so we don't get confused later as
* to how many bytes we have to play with.
*/
hdr->caplen = buflen;
memcpy((char *)buf, (char *)tp, buflen);
} else {
/* read the packet itself */
amt_read = fread((char *)buf, 1, hdr->caplen, fp);
if (amt_read != hdr->caplen) {
if (ferror(fp)) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"error reading dump file: %s",
pcap_strerror(errno));
} else {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"truncated dump file; tried to read %u captured bytes, only got %lu",
hdr->caplen, (unsigned long)amt_read);
}
return (-1);
}
}
return (0);
}
/*
* Print out packets stored in the file initialized by sf_read_init().
* 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 = p->fcode.bf_insns;
int status = 0;
int n = 0;
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 = sf_next_packet(p, &h, p->buffer, p->bufsize);
if (status) {
if (status == 1)
return (0);
return (status);
}
if (fcode == NULL ||
bpf_filter(fcode, p->buffer, h.len, h.caplen)) {
(*callback)(user, &h, p->buffer);
if (++n >= cnt && cnt > 0)
break;
}
}
/*XXX this breaks semantics tcpslice expects */
return (n);
}
/*
* Output a packet to the initialized dump file.
*/
void
pcap_dump(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
{
register FILE *f;
struct pcap_sf_pkthdr sf_hdr;
f = (FILE *)user;
sf_hdr.ts.tv_sec = h->ts.tv_sec;
sf_hdr.ts.tv_usec = h->ts.tv_usec;
sf_hdr.caplen = h->caplen;
sf_hdr.len = h->len;
/* XXX we should check the return status */
(void)fwrite(&sf_hdr, sizeof(sf_hdr), 1, f);
(void)fwrite((char *)sp, h->caplen, 1, f);
}
/*
* Initialize so that sf_write() will output to the file named 'fname'.
*/
pcap_dumper_t *
pcap_dump_open(pcap_t *p, const char *fname)
{
FILE *f;
int linktype;
linktype = dlt_to_linktype(p->linktype);
if (linktype == -1) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"%s: link-layer type %d isn't supported in savefiles",
fname, linktype);
return (NULL);
}
if (fname[0] == '-' && fname[1] == '\0') {
f = stdout;
#ifdef WIN32
_setmode(_fileno(f), _O_BINARY);
#endif
} else {
#ifndef WIN32
f = fopen(fname, "w");
#else
f = fopen(fname, "wb");
setbuf(f, NULL); /* XXX - why? */
#endif
if (f == NULL) {
(void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s: %s",
fname, pcap_strerror(errno));
return (NULL);
}
}
(void)sf_write_header(f, linktype, p->tzoff, p->snapshot);
return ((pcap_dumper_t *)f);
}
FILE *
pcap_dump_file(pcap_dumper_t *p)
{
return ((FILE *)p);
}
int
pcap_dump_flush(pcap_dumper_t *p)
{
if (fflush((FILE *)p) == EOF)
return (-1);
else
return (0);
}
void
pcap_dump_close(pcap_dumper_t *p)
{
#ifdef notyet
if (ferror((FILE *)p))
return-an-error;
/* XXX should check return from fclose() too */
#endif
(void)fclose((FILE *)p);
}
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