| /* |
| * Copyright (c) 1990, 1991, 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. |
| */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include "config.h" |
| #endif |
| |
| #ifndef lint |
| static const char rcsid[] _U_ = |
| "@(#) $Header: /tcpdump/master/tcpdump/print-vjc.c,v 1.15 2004-03-25 03:31:17 mcr Exp $ (LBL)"; |
| #endif |
| |
| #include <tcpdump-stdinc.h> |
| |
| #include <pcap.h> |
| #include <stdio.h> |
| |
| #include "interface.h" |
| #include "addrtoname.h" |
| |
| #include "slcompress.h" |
| #include "ppp.h" |
| |
| /* |
| * XXX - for BSD/OS PPP, what packets get supplied with a PPP header type |
| * of PPP_VJC and what packets get supplied with a PPP header type of |
| * PPP_VJNC? PPP_VJNC is for "UNCOMPRESSED_TCP" packets, and PPP_VJC |
| * is for COMPRESSED_TCP packets (PPP_IP is used for TYPE_IP packets). |
| * |
| * RFC 1144 implies that, on the wire, the packet type is *not* needed |
| * for PPP, as different PPP protocol types can be used; it only needs |
| * to be put on the wire for SLIP. |
| * |
| * It also indicates that, for compressed SLIP: |
| * |
| * If the COMPRESSED_TCP bit is set in the first byte, it's |
| * a COMPRESSED_TCP packet; that byte is the change byte, and |
| * the COMPRESSED_TCP bit, 0x80, isn't used in the change byte. |
| * |
| * If the upper 4 bits of the first byte are 7, it's an |
| * UNCOMPRESSED_TCP packet; that byte is the first byte of |
| * the UNCOMPRESSED_TCP modified IP header, with a connection |
| * number in the protocol field, and with the version field |
| * being 7, not 4. |
| * |
| * Otherwise, the packet is an IPv4 packet (where the upper 4 bits |
| * of the packet are 4). |
| * |
| * So this routine looks as if it's sort-of intended to handle |
| * compressed SLIP, although it doesn't handle UNCOMPRESSED_TCP |
| * correctly for that (it doesn't fix the version number and doesn't |
| * do anything to the protocol field), and doesn't check for COMPRESSED_TCP |
| * packets correctly for that (you only check the first bit - see |
| * B.1 in RFC 1144). |
| * |
| * But it's called for BSD/OS PPP, not SLIP - perhaps BSD/OS does weird |
| * things with the headers? |
| * |
| * Without a BSD/OS VJC-compressed PPP trace, or knowledge of what the |
| * BSD/OS VJC code does, we can't say what's the case. |
| * |
| * We therefore leave "proto" - which is the PPP protocol type - in place, |
| * *not* marked as unused, for now, so that GCC warnings about the |
| * unused argument remind us that we should fix this some day. |
| */ |
| int |
| vjc_print(register const char *bp, u_short proto _U_) |
| { |
| int i; |
| |
| switch (bp[0] & 0xf0) { |
| case TYPE_IP: |
| if (eflag) |
| printf("(vjc type=IP) "); |
| return PPP_IP; |
| case TYPE_UNCOMPRESSED_TCP: |
| if (eflag) |
| printf("(vjc type=raw TCP) "); |
| return PPP_IP; |
| case TYPE_COMPRESSED_TCP: |
| if (eflag) |
| printf("(vjc type=compressed TCP) "); |
| for (i = 0; i < 8; i++) { |
| if (bp[1] & (0x80 >> i)) |
| printf("%c", "?CI?SAWU"[i]); |
| } |
| if (bp[1]) |
| printf(" "); |
| printf("C=0x%02x ", bp[2]); |
| printf("sum=0x%04x ", *(u_short *)&bp[3]); |
| return -1; |
| case TYPE_ERROR: |
| if (eflag) |
| printf("(vjc type=error) "); |
| return -1; |
| default: |
| if (eflag) |
| printf("(vjc type=0x%02x) ", bp[0] & 0xf0); |
| return -1; |
| } |
| } |