forked from osmocom/wireshark
ee39938f67
and in different capture files; throw in some heuristics to try to figure out whether the 4-byte header is: 1) PPP-over-HDLC (some version of ISDN4BSD?); 2) big-endian AF_ value (BSD on big-endian platforms); 3) little-endian AF_ value (BSD on little-endian platforms); 4) two octets of 0 followed by an Ethernet type (Linux, at least on little-endian platforms, as mutated by "libpcap"). Make a separate Wiretap encapsulation type, WTAP_ENCAP_NULL, corresponding to DLT_NULL. Have the PPP code dissect the frame if it's PPP-over-HDLC, and have "ethertype()" dissect the Ethernet type and the rest of the packet if it's a Linux-style header; dissect it ourselves only if it's an AF_ value. Have Wiretap impose a maximum packet size of 65535 bytes, so that it fails more gracefully when handed a corrupt "libpcap" capture file (other capture file formats with more than a 16-bit capture length field, if any, will have that check added later), and put that size in "wtap.h" and have Ethereal use it as its notion of a maximum packet size. Have Ethereal put up a "this file appears to be damaged or corrupt" message box if Wiretap returns a WTAP_ERR_BAD_RECORD error when opening or reading a capture file. Include loopback interfaces in the list of interfaces offered by the "Capture" dialog box, but put them at the end of the list so that it doesn't default to a loopback interface unless there are no other interfaces. Also, don't require that an interface in the list have an IP address associated with it, and only put one entry in the list for a given interface (SIOCGIFCONF returns one entry per interface *address*, not per *interface* - and even if you were to use only IP addresses, an interface could conceivably have more than one IP address). Exclusively use Wiretap encapsulation types internally, even when capturing; don't use DLT_ types. svn path=/trunk/; revision=540 |
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| .. | ||
| AUTHORS | ||
| COPYING | ||
| ChangeLog | ||
| INSTALL | ||
| Makefile | ||
| Makefile.am | ||
| Makefile.nmake | ||
| NEWS | ||
| README | ||
| acconfig.h | ||
| acinclude.m4 | ||
| buffer.c | ||
| buffer.h | ||
| config.h.win32 | ||
| configure.in | ||
| file.c | ||
| iptrace.c | ||
| iptrace.h | ||
| lanalyzer.c | ||
| lanalyzer.h | ||
| libpcap.c | ||
| libpcap.h | ||
| netmon.c | ||
| netmon.h | ||
| netxray.c | ||
| netxray.h | ||
| ngsniffer.c | ||
| ngsniffer.h | ||
| radcom.c | ||
| radcom.h | ||
| snoop.c | ||
| snoop.h | ||
| wtap.c | ||
| wtap.h | ||
README
$Id: README,v 1.16 1999/08/20 07:55:49 guy Exp $ Wiretap is a library that is being developed as a future replacement for libpcap, the current standard Unix library for packet capturing. Libpcap is great in that it is very platform independent and has a wonderful BPF optimizing engine. But it has some shortcomings as well. These shortcomings came to a head during the development of Ethereal (http://ethereal.zing.org), a packet analyzer. As such, I began developing wiretap so that: 1. The library can easily be amended with new packet filtering objects. Libpcap is very TCP/IP-oriented. I want to filter on IPX objects, SNA objects, etc. I also want any decent programmer to be able to add new filters to the library. 2. The library can read file formats from many packet-capturing utilities. Libpcap only reads Libpcap files. 3. The library can capture on more than one network interface at a time, and save this trace in one file. 4. Network names can be resolved immediately after a trace and saved in the trace file. That way, I can ship a trace of my firewall-protected network to a colleague, and he'll see the proper hostnames for the IP addresses in the packet capture, even though he doesn't have access to the DNS server behind my LAN's firewall. 5. I want to look into the possibility of compressing packet data when saved to a file, like Sniffer. 6. The packet-filter can be optimized for the host OS. Not all OSes have BPF; SunOS has NIT and Solaris has DLPI, which both use the CMU/Stanford packet-filter pseudomachine. RMON has another type of packet-filter syntax which we could support. Wiretap is very good at reading many file formats, as per #2 above. Wiretap has no filter capability at present; it currently doesn't support packet capture, so it wouldn't be useful there, and filtering when reading a capture file is done by Ethereal, using a more powerful filtering mechanism than that provided by BPF. File Formats ============ Libpcap ------- The "libpcap" file format was determined by reading the "libpcap" code; wiretap reads the "libpcap" file format with its own code, rather than using the "libpcap" library's code to read it. Sniffer (uncompressed) ------- The Sniffer format is documented in the Sniffer manual. Unfortunately, Sniffer manuals tend to document only the format for the Sniffer model they document. Token-Ring and ethernet seems to work well, though. If you have an ATM Sniffer file, both Guy and Gilbert would be *very* interested in receiving a sample. (see 'AUTHORS' file for our e-mail addresses). LANalyzer --------- The LANalyzer format is available from http://www.novell.com. Search their knowledge base for "Trace File Format". Network Monitor --------------- Microsoft's Network Monitor file format is supported, at least under Ethernet and token-ring. If you have capture files of other datalink types, please send them to Guy. "snoop" ------- The Solaris 2.x "snoop" program's format is documented in RFC 1761. "iptrace" --------- This is the capture program that comes with AIX 3.x and 4.x. Right now wiretap only supports iptrace 2.0 (AIX4) because I don't have access to an AIX3 machine. iptrace has an undocumented, yet very simple, file format. The interesting thing about iptrace is that it will record packets coming in from all network interfaces; a single iptrace file can contain multiple datalink types. I have tested iptrace on ethernet and token-ring; if you can provide an iptrace file with any other datalink type, I would appreciate a copy. (with the output from 'ipreport' too, if possible). Sniffer Basic (NetXRay)/Windows Sniffer Pro ------------------------------------------- Network Associates' Sniffer Basic (formerly NetXRay from Cinco Networks) file format is now supported, at least for Ethernet and token-ring. Network Associates' Windows Sniffer Pro appears to use a variant of that format; it's supported to the same extent. RADCOM WAN/LAN Analyzers ------------------------ Olivier Abad has added code to read Ethernet and LAPB captures from RADCOM WAN/LAN Analyzers (see http://www.radcom-inc.com/). Gilbert Ramirez <gram@verdict.uthscsa.edu> Guy Harris <guy@netapp.com>