The Tcpdump Group git mirrors - tcpdump/blob - print-pppoe.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 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 #ifndef lint
  23 static const char rcsid[] =
  24 "@(#) $Header: /tcpdump/master/tcpdump/print-pppoe.c,v 1.18 2002-09-05 21:25:45 guy Exp $ (LBL)";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <tcpdump-stdinc.h>
  32
  33 #include <stdio.h>
  34 #include <string.h>
  35
  36 #include "interface.h"
  37 #include "addrtoname.h"
  38 #include "ppp.h"
  39 #include "ethertype.h"
  40 #include "ether.h"
  41 #include "extract.h"                    /* must come after interface.h */
  42
  43 /* Codes */
  44 enum {
  45         PPPOE_PADI = 0x09,
  46         PPPOE_PADO = 0x07,
  47         PPPOE_PADR = 0x19,
  48         PPPOE_PADS = 0x65,
  49         PPPOE_PADT = 0xa7
  50 };
  51
  52 static struct tok pppoecode2str[] = {
  53         { PPPOE_PADI, "PADI" },
  54         { PPPOE_PADO, "PADO" },
  55         { PPPOE_PADR, "PADR" },
  56         { PPPOE_PADS, "PADS" },
  57         { PPPOE_PADT, "PADT" },
  58         { 0, "" }, /* PPP Data */
  59         { 0, NULL }
  60 };
  61
  62 /* Tags */
  63 enum {
  64         PPPOE_EOL = 0,
  65         PPPOE_SERVICE_NAME = 0x0101,
  66         PPPOE_AC_NAME = 0x0102,
  67         PPPOE_HOST_UNIQ = 0x0103,
  68         PPPOE_AC_COOKIE = 0x0104,
  69         PPPOE_VENDOR = 0x0105,
  70         PPPOE_RELAY_SID = 0x0110,
  71         PPPOE_SERVICE_NAME_ERROR = 0x0201,
  72         PPPOE_AC_SYSTEM_ERROR = 0x0202,
  73         PPPOE_GENERIC_ERROR = 0x0203
  74 };
  75
  76 static struct tok pppoetag2str[] = {
  77         { PPPOE_EOL, "EOL" },
  78         { PPPOE_SERVICE_NAME, "Service-Name" },
  79         { PPPOE_AC_NAME, "AC-Name" },
  80         { PPPOE_HOST_UNIQ, "Host-Uniq" },
  81         { PPPOE_AC_COOKIE, "AC-Cookie" },
  82         { PPPOE_VENDOR, "Vendor-Specific" },
  83         { PPPOE_RELAY_SID, "Relay-Session-ID" },
  84         { PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" },
  85         { PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" },
  86         { PPPOE_GENERIC_ERROR, "Generic-Error" },
  87         { 0, NULL }
  88 };
  89
  90 #define PPPOE_HDRLEN 6
  91
  92 void
  93 pppoe_if_print(u_char *user _U_, const struct pcap_pkthdr *h,
  94              register const u_char *p)
  95 {
  96         register u_int length = h->len;
  97         register u_int caplen = h->caplen;
  98         u_int hdr_len;
  99
 100         ++infodelay;
 101         ts_print(&h->ts);
 102
 103         /*
 104          * Some printers want to get back at the link level addresses,
 105          * and/or check that they're not walking off the end of the packet.
 106          * Rather than pass them all the way down, we set these globals.
 107          */
 108         packetp = p;
 109         snapend = p + caplen;
 110
 111         hdr_len = pppoe_print(p, length);
 112
 113         /*
 114          * If "-x" was specified, print stuff past the PPPoE and PPP headers,
 115          * if there's anything to print.
 116          */
 117         if (xflag && caplen > hdr_len)
 118                 default_print(p + hdr_len, caplen - hdr_len);
 119
 120         putchar('\n');
 121
 122         --infodelay;
 123         if (infoprint)
 124                 info(0);
 125 }
 126
 127 u_int
 128 pppoe_print(register const u_char *bp, u_int length)
 129 {
 130         u_short pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid, pppoe_length;
 131         const u_char *pppoe_packet, *pppoe_payload;
 132
 133         pppoe_packet = bp;
 134         if (pppoe_packet > snapend) {
 135                 printf("[|pppoe]");
 136                 return (PPPOE_HDRLEN);
 137         }
 138
 139         pppoe_ver  = (pppoe_packet[0] & 0xF0) >> 4;
 140         pppoe_type  = (pppoe_packet[0] & 0x0F);
 141         pppoe_code = pppoe_packet[1];
 142         pppoe_sessionid = EXTRACT_16BITS(pppoe_packet + 2);
 143         pppoe_length    = EXTRACT_16BITS(pppoe_packet + 4);
 144         pppoe_payload = pppoe_packet + PPPOE_HDRLEN;
 145
 146         if (snapend < pppoe_payload) {
 147                 printf(" truncated PPPoE");
 148                 return (PPPOE_HDRLEN);
 149         }
 150
 151         if (pppoe_ver != 1) {
 152                 printf(" [ver %d]",pppoe_ver);
 153         }
 154         if (pppoe_type != 1) {
 155                 printf(" [type %d]",pppoe_type);
 156         }
 157
 158         printf("PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code));
 159         if (pppoe_code == PPPOE_PADI && pppoe_length > 1484 - PPPOE_HDRLEN) {
 160                 printf(" [len %d!]",pppoe_length);
 161         }
 162         if (pppoe_sessionid) {
 163                 printf(" [ses 0x%x]", pppoe_sessionid);
 164         }
 165
 166         if (pppoe_payload + pppoe_length < snapend) {
 167 #if 0
 168                 const u_char *x = pppoe_payload + pppoe_length;
 169                 printf(" [length %d (%d extra bytes)]",
 170                     pppoe_length, snapend - pppoe_payload - pppoe_length);
 171                 default_print(x, snapend - x);
 172 #endif
 173                 snapend = pppoe_payload+pppoe_length;
 174         }
 175
 176         if (pppoe_code) {
 177                 /* PPP session packets don't contain tags */
 178                 u_short tag_type = 0xffff, tag_len;
 179                 const u_char *p = pppoe_payload;
 180
 181                 /*
 182                  * loop invariant:
 183                  * p points to next tag,
 184                  * tag_type is previous tag or 0xffff for first iteration
 185                  */
 186                 while (tag_type && p + 4 < pppoe_payload + length &&
 187                     p + 4 < snapend) {
 188                         tag_type = EXTRACT_16BITS(p);
 189                         tag_len = EXTRACT_16BITS(p + 2);
 190                         p += 4;
 191                         /* p points to tag_value */
 192
 193                         if (tag_len) {
 194                                 int isascii = 1;
 195                                 const u_char *v = p;
 196                                 u_short l;
 197
 198                                 for (v = p; v < p + tag_len; v++)
 199                                         if (*v >= 127 || *v < 32) {
 200                                                 isascii = 0;
 201                                                 break;
 202                                         }
 203
 204                                 /* TODO print UTF8 decoded text */
 205                                 if (isascii) {
 206                                         l = (tag_len < 80 ? tag_len : 80);
 207                                         printf(" [%s \"%*.*s\"]",
 208                                             tok2str(pppoetag2str, "TAG-0x%x", tag_type),
 209                                             l, l, p);
 210                                 } else
 211                                         printf(" [%s UTF8]",
 212                                             tok2str(pppoetag2str, "TAG-0x%x", tag_type));
 213                         } else
 214                                 printf(" [%s]", tok2str(pppoetag2str,
 215                                     "TAG-0x%x", tag_type));
 216
 217                         p += tag_len;
 218                         /* p points to next tag */
 219                 }
 220                 return (0);
 221         } else {
 222                 /* PPPoE data */
 223                 printf(" ");
 224                 return (PPPOE_HDRLEN + ppp_print(pppoe_payload, pppoe_length));
 225         }
 226 }