![Guy Harris](/assets/img/avatar_default.png)
capture file for an unsupported link-layer encapsulation type (as the nettl reader does), and report it correctly if it occurs on an open or read attempt rather than a save attempt. svn path=/trunk/; revision=1647
472 lines
14 KiB
C
472 lines
14 KiB
C
/* snoop.c
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*
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* $Id: snoop.c,v 1.25 2000/02/19 08:00:04 guy Exp $
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*
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* Wiretap Library
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* Copyright (c) 1998 by Gilbert Ramirez <gram@xiexie.org>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <errno.h>
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#include "wtap.h"
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#include "file_wrappers.h"
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#include "buffer.h"
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#include "snoop.h"
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#ifdef HAVE_NETINET_IN_H
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#include <netinet/in.h>
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#endif
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/* See RFC 1761 for a description of the "snoop" file format. */
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/* Magic number in "snoop" files. */
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static const char snoop_magic[] = {
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's', 'n', 'o', 'o', 'p', '\0', '\0', '\0'
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};
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/* "snoop" file header (minus magic number). */
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struct snoop_hdr {
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guint32 version; /* version number (should be 2) */
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guint32 network; /* network type */
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};
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/* "snoop" record header. */
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struct snooprec_hdr {
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guint32 orig_len; /* actual length of packet */
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guint32 incl_len; /* number of octets captured in file */
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guint32 rec_len; /* length of record */
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guint32 cum_drops; /* cumulative number of dropped packets */
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guint32 ts_sec; /* timestamp seconds */
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guint32 ts_usec; /* timestamp microseconds */
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};
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static int snoop_read(wtap *wth, int *err);
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static gboolean snoop_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
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const u_char *pd, int *err);
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/*
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* See
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*
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* http://www.opengroup.org/onlinepubs/9638599/apdxf.htm
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*
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* for the "dlpi.h" header file specified by The Open Group, which lists
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* the DL_ values for various protocols; Solaris 7 uses the same values.
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*
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* The page at
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*
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* http://mrpink.lerc.nasa.gov/118x/support.html
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*
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* has links to modified versions of "tcpdump" and "libpcap" for SUNatm
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* DLPI support; they suggest the 3.0 verson of SUNatm uses those
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* values.
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*
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* It also has a link to "convert.c", which is a program to convert files
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* from the format written by the "atmsnoop" program that comes with the
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* SunATM package to regular "snoop" format, claims that "SunATM 2.1 claimed
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* to be DL_FDDI (don't ask why). SunATM 3.0 claims to be DL_IPATM, which
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* is 0x12".
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*
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* It also says that "ATM Mac header is 12 bytes long.", and seems to imply
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* that in an "atmsnoop" file, the header contains 2 bytes (direction and
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* VPI?), 2 bytes of VCI, 6 bytes of something, and 2 bytes of Ethernet
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* type; if those 6 bytes are 2 bytes of DSAP, 2 bytes of LSAP, 1 byte
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* of LLC control, and 3 bytes of SNAP OUI, that'd mean that an ATM
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* pseudo-header in an "atmsnoop" file is probably 1 byte of direction,
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* 1 byte of VPI, and 2 bytes of VCI.
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*
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* The aforementioned page also has a link to some capture files from
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* "atmsnoop"; this version of "snoop.c" appears to be able to read them.
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*
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* Source to an "atmdump" package, which includes a modified version of
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* "libpcap" to handle SunATM DLPI and an ATM driver for FreeBSD, and
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* also includes "atmdump", which is a modified "tcpdump", says that an
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* ATM packet handed up from the Sun driver for the Sun SBus ATM card on
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* Solaris 2.5.1 has 1 byte of direction, 1 byte of VPI, 2 bytes of VCI,
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* and then the ATM PDU, and suggests that the direction byte is 0x80 for
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* "transmitted" (presumably meaning DTE->DCE) and presumably not 0x80 for
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* "received" (presumably meaning DCE->DTE).
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*
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* In fact, the "direction" byte appears to have some other stuff, perhaps
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* a traffic type, in the lower 7 bits, with the 8th bit indicating the
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* direction.
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*
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* I don't know what the encapsulation of any of the other types is, so I
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* leave them all as WTAP_ENCAP_UNKNOWN. I also don't know whether "snoop"
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* can handle any of them (it presumably can't handle ATM, otherwise Sun
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* wouldn't have supplied "atmsnoop"; even if it can't, this may be useful
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* reference information for anybody doing code to use DLPI to do raw packet
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* captures on those network types.
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*/
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int snoop_open(wtap *wth, int *err)
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{
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int bytes_read;
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char magic[sizeof snoop_magic];
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struct snoop_hdr hdr;
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static const int snoop_encap[] = {
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WTAP_ENCAP_ETHERNET, /* IEEE 802.3 */
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WTAP_ENCAP_UNKNOWN, /* IEEE 802.4 Token Bus */
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WTAP_ENCAP_TR,
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WTAP_ENCAP_UNKNOWN, /* IEEE 802.6 Metro Net */
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WTAP_ENCAP_ETHERNET,
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WTAP_ENCAP_UNKNOWN, /* HDLC */
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WTAP_ENCAP_UNKNOWN, /* Character Synchronous, e.g. bisync */
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WTAP_ENCAP_UNKNOWN, /* IBM Channel-to-Channel */
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WTAP_ENCAP_FDDI_BITSWAPPED,
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WTAP_ENCAP_UNKNOWN, /* Other */
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WTAP_ENCAP_UNKNOWN, /* Frame Relay LAPF */
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WTAP_ENCAP_UNKNOWN, /* Multi-protocol over Frame Relay */
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WTAP_ENCAP_UNKNOWN, /* Character Async (e.g., SLIP and PPP?) */
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WTAP_ENCAP_UNKNOWN, /* X.25 Classical IP */
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WTAP_ENCAP_UNKNOWN, /* software loopback */
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WTAP_ENCAP_UNKNOWN, /* not defined in "dlpi.h" */
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WTAP_ENCAP_UNKNOWN, /* Fibre Channel */
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WTAP_ENCAP_UNKNOWN, /* ATM */
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WTAP_ENCAP_ATM_SNIFFER, /* ATM Classical IP */
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WTAP_ENCAP_UNKNOWN, /* X.25 LAPB */
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WTAP_ENCAP_UNKNOWN, /* ISDN */
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WTAP_ENCAP_UNKNOWN, /* HIPPI */
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WTAP_ENCAP_UNKNOWN, /* 100VG-AnyLAN Ethernet */
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WTAP_ENCAP_UNKNOWN, /* 100VG-AnyLAN Token Ring */
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WTAP_ENCAP_UNKNOWN, /* "ISO 8802/3 and Ethernet" */
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WTAP_ENCAP_UNKNOWN, /* 100BaseT (but that's just Ethernet) */
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};
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#define NUM_SNOOP_ENCAPS (sizeof snoop_encap / sizeof snoop_encap[0])
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/* Read in the string that should be at the start of a "snoop" file */
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file_seek(wth->fh, 0, SEEK_SET);
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wth->data_offset = 0;
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errno = WTAP_ERR_CANT_READ;
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bytes_read = file_read(magic, 1, sizeof magic, wth->fh);
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if (bytes_read != sizeof magic) {
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*err = file_error(wth->fh);
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if (*err != 0)
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return -1;
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return 0;
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}
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wth->data_offset += sizeof magic;
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if (memcmp(magic, snoop_magic, sizeof snoop_magic) != 0) {
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return 0;
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}
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/* Read the rest of the header. */
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errno = WTAP_ERR_CANT_READ;
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bytes_read = file_read(&hdr, 1, sizeof hdr, wth->fh);
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if (bytes_read != sizeof hdr) {
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*err = file_error(wth->fh);
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if (*err != 0)
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return -1;
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return 0;
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}
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wth->data_offset += sizeof hdr;
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hdr.version = ntohl(hdr.version);
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if (hdr.version != 2) {
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/* We only support version 2. */
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g_message("snoop: version %u unsupported", hdr.version);
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*err = WTAP_ERR_UNSUPPORTED;
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return -1;
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}
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hdr.network = ntohl(hdr.network);
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if (hdr.network >= NUM_SNOOP_ENCAPS
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|| snoop_encap[hdr.network] == WTAP_ENCAP_UNKNOWN) {
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g_message("snoop: network type %u unknown or unsupported",
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hdr.network);
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*err = WTAP_ERR_UNSUPPORTED_ENCAP;
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return -1;
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}
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/* This is a snoop file */
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wth->file_type = WTAP_FILE_SNOOP;
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wth->subtype_read = snoop_read;
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wth->file_encap = snoop_encap[hdr.network];
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wth->snapshot_length = 16384; /* XXX - not available in header */
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return 1;
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}
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/* Read the next packet */
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static int snoop_read(wtap *wth, int *err)
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{
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guint32 rec_size;
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guint32 packet_size;
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guint32 orig_size;
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int bytes_read;
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struct snooprec_hdr hdr;
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char atm_phdr[4];
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int data_offset;
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char padbuf[4];
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int padbytes;
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int bytes_to_read;
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/* Read record header. */
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errno = WTAP_ERR_CANT_READ;
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bytes_read = file_read(&hdr, 1, sizeof hdr, wth->fh);
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if (bytes_read != sizeof hdr) {
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*err = file_error(wth->fh);
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if (*err != 0)
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return -1;
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if (bytes_read != 0) {
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*err = WTAP_ERR_SHORT_READ;
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return -1;
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}
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return 0;
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}
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wth->data_offset += sizeof hdr;
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rec_size = ntohl(hdr.rec_len);
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orig_size = ntohl(hdr.orig_len);
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packet_size = ntohl(hdr.incl_len);
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if (packet_size > WTAP_MAX_PACKET_SIZE) {
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/*
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* Probably a corrupt capture file; don't blow up trying
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* to allocate space for an immensely-large packet.
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*/
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g_message("snoop: File has %u-byte packet, bigger than maximum of %u",
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packet_size, WTAP_MAX_PACKET_SIZE);
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*err = WTAP_ERR_BAD_RECORD;
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return -1;
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}
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/*
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* If this is an ATM packet, the first four bytes are the
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* direction of the packet (transmit/receive), the VPI, and
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* the VCI; read them and generate the pseudo-header from
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* them.
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*/
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if (wth->file_encap == WTAP_ENCAP_ATM_SNIFFER) {
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if (packet_size < 4) {
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/*
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* Uh-oh, the packet isn't big enough to even
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* have a pseudo-header.
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*/
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g_message("snoop: atmsnoop file has a %u-byte packet, too small to have even an ATM pseudo-header\n",
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packet_size);
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*err = WTAP_ERR_BAD_RECORD;
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return -1;
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}
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errno = WTAP_ERR_CANT_READ;
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bytes_read = file_read(atm_phdr, 1, 4, wth->fh);
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if (bytes_read != 4) {
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*err = file_error(wth->fh);
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if (*err == 0)
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*err = WTAP_ERR_SHORT_READ;
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return -1;
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}
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wth->phdr.pseudo_header.ngsniffer_atm.channel =
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(atm_phdr[0] & 0x80) ? 1 : 0;
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wth->phdr.pseudo_header.ngsniffer_atm.Vpi = atm_phdr[1];
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wth->phdr.pseudo_header.ngsniffer_atm.Vci = pntohs(&atm_phdr[2]);
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/* We don't have this information */
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wth->phdr.pseudo_header.ngsniffer_atm.cells = 0;
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wth->phdr.pseudo_header.ngsniffer_atm.aal5t_u2u = 0;
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wth->phdr.pseudo_header.ngsniffer_atm.aal5t_len = 0;
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wth->phdr.pseudo_header.ngsniffer_atm.aal5t_chksum = 0;
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/*
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* Assume it's AAL5; we know nothing more about it.
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*
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* For what it's worth, in one "atmsnoop" capture,
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* the lower 7 bits of the first byte of the header
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* were 0x05 for ILMI traffic, 0x06 for Signalling
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* AAL traffic, and 0x02 for at least some RFC 1483-style
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* LLC multiplexed traffic.
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*/
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wth->phdr.pseudo_header.ngsniffer_atm.AppTrafType =
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ATT_AAL5|ATT_HL_UNKNOWN;
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wth->phdr.pseudo_header.ngsniffer_atm.AppHLType =
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AHLT_UNKNOWN;
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/*
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* Don't count the pseudo-header as part of the packet.
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*/
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rec_size -= 4;
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orig_size -= 4;
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packet_size -= 4;
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wth->data_offset += 4;
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}
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buffer_assure_space(wth->frame_buffer, packet_size);
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data_offset = wth->data_offset;
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errno = WTAP_ERR_CANT_READ;
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bytes_read = file_read(buffer_start_ptr(wth->frame_buffer), 1,
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packet_size, wth->fh);
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if (bytes_read != packet_size) {
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*err = file_error(wth->fh);
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if (*err == 0)
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*err = WTAP_ERR_SHORT_READ;
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return -1;
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}
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wth->data_offset += packet_size;
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wth->phdr.ts.tv_sec = ntohl(hdr.ts_sec);
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wth->phdr.ts.tv_usec = ntohl(hdr.ts_usec);
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wth->phdr.caplen = packet_size;
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wth->phdr.len = orig_size;
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wth->phdr.pkt_encap = wth->file_encap;
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/*
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* Skip over the padding (don't "fseek()", as the standard
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* I/O library on some platforms discards buffered data if
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* you do that, which means it does a lot more reads).
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* There's probably not much padding (it's probably padded only
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* to a 4-byte boundary), so we probably need only do one read.
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*/
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padbytes = rec_size - (sizeof hdr + packet_size);
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while (padbytes != 0) {
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bytes_to_read = padbytes;
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if (bytes_to_read > sizeof padbuf)
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bytes_to_read = sizeof padbuf;
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errno = WTAP_ERR_CANT_READ;
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bytes_read = file_read(padbuf, 1, bytes_to_read, wth->fh);
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if (bytes_read != bytes_to_read) {
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*err = file_error(wth->fh);
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if (*err == 0)
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*err = WTAP_ERR_SHORT_READ;
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return -1;
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}
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wth->data_offset += bytes_read;
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padbytes -= bytes_read;
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}
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return data_offset;
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}
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static const int wtap_encap[] = {
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-1, /* WTAP_ENCAP_UNKNOWN -> unsupported */
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0x04, /* WTAP_ENCAP_ETHERNET -> DL_ETHER */
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0x02, /* WTAP_ENCAP_TR -> DL_TPR */
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-1, /* WTAP_ENCAP_SLIP -> unsupported */
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-1, /* WTAP_ENCAP_PPP -> unsupported */
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0x08, /* WTAP_ENCAP_FDDI -> DL_FDDI */
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0x08, /* WTAP_ENCAP_FDDI_BITSWAPPED -> DL_FDDI */
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-1, /* WTAP_ENCAP_RAW_IP -> unsupported */
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-1, /* WTAP_ENCAP_ARCNET -> unsupported */
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-1, /* WTAP_ENCAP_ATM_RFC1483 -> unsupported */
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-1, /* WTAP_ENCAP_LINUX_ATM_CLIP -> unsupported */
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-1, /* WTAP_ENCAP_LAPB -> unsupported*/
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-1, /* WTAP_ENCAP_ATM_SNIFFER -> unsupported */
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0 /* WTAP_ENCAP_NULL -> DLT_NULL */
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};
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#define NUM_WTAP_ENCAPS (sizeof wtap_encap / sizeof wtap_encap[0])
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/* Returns 0 if we could write the specified encapsulation type,
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an error indication otherwise. */
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int snoop_dump_can_write_encap(int filetype, int encap)
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{
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/* Per-packet encapsulations aren't supported. */
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if (encap == WTAP_ENCAP_PER_PACKET)
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return WTAP_ERR_ENCAP_PER_PACKET_UNSUPPORTED;
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if (encap < 0 || encap >= NUM_WTAP_ENCAPS || wtap_encap[encap] == -1)
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return WTAP_ERR_UNSUPPORTED_ENCAP;
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return 0;
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}
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/* Returns TRUE on success, FALSE on failure; sets "*err" to an error code on
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failure */
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gboolean snoop_dump_open(wtap_dumper *wdh, int *err)
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{
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struct snoop_hdr file_hdr;
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int nwritten;
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/* This is a snoop file */
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wdh->subtype_write = snoop_dump;
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wdh->subtype_close = NULL;
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/* Write the file header. */
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nwritten = fwrite(&snoop_magic, 1, sizeof snoop_magic, wdh->fh);
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if (nwritten != sizeof snoop_magic) {
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if (nwritten < 0)
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*err = errno;
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else
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*err = WTAP_ERR_SHORT_WRITE;
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return FALSE;
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}
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/* current "snoop" format is 2 */
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file_hdr.version = htonl(2);
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file_hdr.network = htonl(wtap_encap[wdh->encap]);
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nwritten = fwrite(&file_hdr, 1, sizeof file_hdr, wdh->fh);
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if (nwritten != sizeof file_hdr) {
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if (nwritten < 0)
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*err = errno;
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else
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*err = WTAP_ERR_SHORT_WRITE;
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return FALSE;
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}
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return TRUE;
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}
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/* Write a record for a packet to a dump file.
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Returns TRUE on success, FALSE on failure. */
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static gboolean snoop_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
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const u_char *pd, int *err)
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{
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struct snooprec_hdr rec_hdr;
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int nwritten;
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int reclen;
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int padlen;
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static char zeroes[4];
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/* Record length = header length plus data length... */
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reclen = sizeof rec_hdr + phdr->caplen;
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/* ... plus enough bytes to pad it to a 4-byte boundary. */
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padlen = ((reclen + 3) & ~3) - reclen;
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reclen += padlen;
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rec_hdr.orig_len = htonl(phdr->len);
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rec_hdr.incl_len = htonl(phdr->caplen);
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rec_hdr.rec_len = htonl(reclen);
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rec_hdr.cum_drops = 0;
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rec_hdr.ts_sec = htonl(phdr->ts.tv_sec);
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rec_hdr.ts_usec = htonl(phdr->ts.tv_usec);
|
|
nwritten = fwrite(&rec_hdr, 1, sizeof rec_hdr, wdh->fh);
|
|
if (nwritten != sizeof rec_hdr) {
|
|
if (nwritten < 0)
|
|
*err = errno;
|
|
else
|
|
*err = WTAP_ERR_SHORT_WRITE;
|
|
return FALSE;
|
|
}
|
|
nwritten = fwrite(pd, 1, phdr->caplen, wdh->fh);
|
|
if (nwritten != phdr->caplen) {
|
|
if (nwritten < 0)
|
|
*err = errno;
|
|
else
|
|
*err = WTAP_ERR_SHORT_WRITE;
|
|
return FALSE;
|
|
}
|
|
|
|
/* Now write the padding. */
|
|
nwritten = fwrite(zeroes, 1, padlen, wdh->fh);
|
|
if (nwritten != padlen) {
|
|
if (nwritten < 0)
|
|
*err = errno;
|
|
else
|
|
*err = WTAP_ERR_SHORT_WRITE;
|
|
return FALSE;
|
|
}
|
|
return TRUE;
|
|
}
|