The Android Open Source Project | 2949f58 | 2009-03-03 19:30:46 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that: (1) source code distributions |
| 7 | * retain the above copyright notice and this paragraph in its entirety, (2) |
| 8 | * distributions including binary code include the above copyright notice and |
| 9 | * this paragraph in its entirety in the documentation or other materials |
| 10 | * provided with the distribution, and (3) all advertising materials mentioning |
| 11 | * features or use of this software display the following acknowledgement: |
| 12 | * ``This product includes software developed by the University of California, |
| 13 | * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of |
| 14 | * the University nor the names of its contributors may be used to endorse |
| 15 | * or promote products derived from this software without specific prior |
| 16 | * written permission. |
| 17 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED |
| 18 | * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF |
| 19 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| 20 | */ |
| 21 | |
| 22 | #ifdef HAVE_CONFIG_H |
| 23 | #include "config.h" |
| 24 | #endif |
| 25 | |
| 26 | #ifndef lint |
| 27 | static const char rcsid[] _U_ = |
JP Abgrall | 53f17a9 | 2014-02-12 14:02:41 -0800 | [diff] [blame] | 28 | "@(#) $Header: /tcpdump/master/tcpdump/print-vjc.c,v 1.15 2004-03-25 03:31:17 mcr Exp $ (LBL)"; |
The Android Open Source Project | 2949f58 | 2009-03-03 19:30:46 -0800 | [diff] [blame] | 29 | #endif |
| 30 | |
| 31 | #include <tcpdump-stdinc.h> |
| 32 | |
| 33 | #include <pcap.h> |
| 34 | #include <stdio.h> |
| 35 | |
| 36 | #include "interface.h" |
| 37 | #include "addrtoname.h" |
| 38 | |
| 39 | #include "slcompress.h" |
| 40 | #include "ppp.h" |
| 41 | |
| 42 | /* |
| 43 | * XXX - for BSD/OS PPP, what packets get supplied with a PPP header type |
| 44 | * of PPP_VJC and what packets get supplied with a PPP header type of |
| 45 | * PPP_VJNC? PPP_VJNC is for "UNCOMPRESSED_TCP" packets, and PPP_VJC |
| 46 | * is for COMPRESSED_TCP packets (PPP_IP is used for TYPE_IP packets). |
| 47 | * |
| 48 | * RFC 1144 implies that, on the wire, the packet type is *not* needed |
| 49 | * for PPP, as different PPP protocol types can be used; it only needs |
| 50 | * to be put on the wire for SLIP. |
| 51 | * |
| 52 | * It also indicates that, for compressed SLIP: |
| 53 | * |
| 54 | * If the COMPRESSED_TCP bit is set in the first byte, it's |
| 55 | * a COMPRESSED_TCP packet; that byte is the change byte, and |
| 56 | * the COMPRESSED_TCP bit, 0x80, isn't used in the change byte. |
| 57 | * |
| 58 | * If the upper 4 bits of the first byte are 7, it's an |
| 59 | * UNCOMPRESSED_TCP packet; that byte is the first byte of |
| 60 | * the UNCOMPRESSED_TCP modified IP header, with a connection |
| 61 | * number in the protocol field, and with the version field |
| 62 | * being 7, not 4. |
| 63 | * |
| 64 | * Otherwise, the packet is an IPv4 packet (where the upper 4 bits |
| 65 | * of the packet are 4). |
| 66 | * |
| 67 | * So this routine looks as if it's sort-of intended to handle |
| 68 | * compressed SLIP, although it doesn't handle UNCOMPRESSED_TCP |
| 69 | * correctly for that (it doesn't fix the version number and doesn't |
| 70 | * do anything to the protocol field), and doesn't check for COMPRESSED_TCP |
| 71 | * packets correctly for that (you only check the first bit - see |
| 72 | * B.1 in RFC 1144). |
| 73 | * |
| 74 | * But it's called for BSD/OS PPP, not SLIP - perhaps BSD/OS does weird |
| 75 | * things with the headers? |
| 76 | * |
| 77 | * Without a BSD/OS VJC-compressed PPP trace, or knowledge of what the |
| 78 | * BSD/OS VJC code does, we can't say what's the case. |
| 79 | * |
| 80 | * We therefore leave "proto" - which is the PPP protocol type - in place, |
| 81 | * *not* marked as unused, for now, so that GCC warnings about the |
| 82 | * unused argument remind us that we should fix this some day. |
| 83 | */ |
| 84 | int |
| 85 | vjc_print(register const char *bp, u_short proto _U_) |
| 86 | { |
| 87 | int i; |
| 88 | |
| 89 | switch (bp[0] & 0xf0) { |
| 90 | case TYPE_IP: |
| 91 | if (eflag) |
| 92 | printf("(vjc type=IP) "); |
| 93 | return PPP_IP; |
| 94 | case TYPE_UNCOMPRESSED_TCP: |
| 95 | if (eflag) |
| 96 | printf("(vjc type=raw TCP) "); |
| 97 | return PPP_IP; |
| 98 | case TYPE_COMPRESSED_TCP: |
| 99 | if (eflag) |
| 100 | printf("(vjc type=compressed TCP) "); |
| 101 | for (i = 0; i < 8; i++) { |
| 102 | if (bp[1] & (0x80 >> i)) |
| 103 | printf("%c", "?CI?SAWU"[i]); |
| 104 | } |
| 105 | if (bp[1]) |
| 106 | printf(" "); |
| 107 | printf("C=0x%02x ", bp[2]); |
| 108 | printf("sum=0x%04x ", *(u_short *)&bp[3]); |
| 109 | return -1; |
| 110 | case TYPE_ERROR: |
| 111 | if (eflag) |
| 112 | printf("(vjc type=error) "); |
| 113 | return -1; |
| 114 | default: |
| 115 | if (eflag) |
| 116 | printf("(vjc type=0x%02x) ", bp[0] & 0xf0); |
| 117 | return -1; |
| 118 | } |
| 119 | } |