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 1.12 2000-10-09 02:59:40 guy Exp $ (LBL)";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <sys/param.h>
  32 #include <sys/time.h>
  33 #include <sys/socket.h>
  34
  35 #include <netinet/in.h>
  36
  37 #include <stdio.h>
  38 #include <string.h>
  39
  40 #include "interface.h"
  41 #include "addrtoname.h"
  42 #include "ppp.h"
  43 #include "ethertype.h"
  44 #include "ether.h"
  45 #include "extract.h"                    /* must come after interface.h */
  46
  47 /* Codes */
  48 enum {
  49   PPPOE_PADI = 0x09,
  50   PPPOE_PADO = 0x07,
  51   PPPOE_PADR = 0x19,
  52   PPPOE_PADS = 0x65,
  53   PPPOE_PADT = 0xa7
  54 };
  55
  56 static struct tok pppoecode2str[] = {
  57   { PPPOE_PADI, "PADI"},
  58   { PPPOE_PADO, "PADO"},
  59   { PPPOE_PADR, "PADR"},
  60   { PPPOE_PADS, "PADS"},
  61   { PPPOE_PADT, "PADT"},
  62   { 0, ""}, /* PPP Data */
  63   { 0, NULL }
  64 };
  65
  66 /* Tags */
  67 enum {
  68   PPPOE_EOL = 0,
  69   PPPOE_SERVICE_NAME = 0x0101,
  70   PPPOE_AC_NAME = 0x0102,
  71   PPPOE_HOST_UNIQ = 0x0103,
  72   PPPOE_AC_COOKIE = 0x0104,
  73   PPPOE_VENDOR = 0x0105,
  74   PPPOE_RELAY_SID = 0x0110,
  75   PPPOE_SERVICE_NAME_ERROR = 0x0201,
  76   PPPOE_AC_SYSTEM_ERROR = 0x0202,
  77   PPPOE_GENERIC_ERROR = 0x0203
  78 };
  79
  80 static struct tok pppoetag2str[] = {
  81   { PPPOE_EOL, "EOL"},
  82   { PPPOE_SERVICE_NAME, "Service-Name" },
  83   { PPPOE_AC_NAME, "AC-Name" },
  84   { PPPOE_HOST_UNIQ, "Host-Uniq" },
  85   { PPPOE_AC_COOKIE, "AC-Cookie" },
  86   { PPPOE_VENDOR, "Vendor-Specific" },
  87   { PPPOE_RELAY_SID, "Relay-Session-ID" },
  88   { PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" },
  89   { PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" },
  90   { PPPOE_GENERIC_ERROR, "Generic-Error" },
  91   { 0, NULL}
  92 };
  93
  94 #define PPPOE_HDRLEN 6
  95
  96 void
  97 pppoe_print(register const u_char *bp, u_int length)
  98 {
  99   register const struct ether_header *eh;
 100   register u_short pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid, pppoe_length;
 101   const u_char *pppoe_packet, *pppoe_payload;
 102
 103   eh = (struct ether_header *)packetp;
 104   pppoe_packet = packetp+ETHER_HDRLEN;
 105   if (pppoe_packet > snapend) {
 106     printf("[|pppoe]");
 107     return;
 108   }
 109
 110   pppoe_ver  = (pppoe_packet[0]&0xF0)>>4;
 111   pppoe_type  = (pppoe_packet[0]&0x0F);
 112   pppoe_code = (pppoe_packet[1]);
 113   pppoe_sessionid = (EXTRACT_16BITS(pppoe_packet+2));
 114   pppoe_length    = (EXTRACT_16BITS(pppoe_packet+4));
 115   pppoe_payload = pppoe_packet+6;
 116
 117   if (snapend < pppoe_payload) {
 118     printf(" truncated PPPoE");
 119     return;
 120   }
 121
 122   if (pppoe_ver != 1) {
 123     printf(" [ver %d]",pppoe_ver);
 124   }
 125   if (pppoe_type != 1) {
 126     printf(" [type %d]",pppoe_type);
 127   }
 128
 129   printf("PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code));
 130   if (pppoe_code == PPPOE_PADI && pppoe_length > 1484-PPPOE_HDRLEN) {
 131     printf(" [len %d!]",pppoe_length);
 132   }
 133   if (pppoe_sessionid) {
 134     printf(" [ses 0x%x]",pppoe_sessionid);
 135   }
 136
 137   if (pppoe_payload + pppoe_length < snapend) {
 138     /*
 139     printf(" [length %d (%d extra bytes)]", pppoe_length, snapend-pppoe_payload-pppoe_length);
 140     {
 141       const u_char *x = pppoe_payload+pppoe_length;
 142       default_print(x, snapend - x);
 143     }
 144     */
 145     snapend = pppoe_payload+pppoe_length;
 146   }
 147
 148
 149   if (pppoe_code) {
 150     /* PPP session packets don't contain tags */
 151     u_short tag_type = 0xffff, tag_len;
 152     const u_char *p = pppoe_payload;
 153
 154     /* loop invariant:
 155        p points to next tag,
 156        tag_type is previous tag or 0xffff for first iteration
 157     */
 158     while (tag_type &&
 159            p+4 < pppoe_payload + length &&
 160            p+4 < snapend) {
 161       tag_type = EXTRACT_16BITS(p);
 162       tag_len  = EXTRACT_16BITS(p+2);
 163       p += 4;
 164       /* p points to tag_value */
 165
 166       if (tag_len) {
 167         int isascii = 1;
 168         const u_char *v = p;
 169
 170         for (v=p; v<p+tag_len; v++)
 171           if (*v >= 127 || *v < 32) {
 172             isascii = 0;
 173             break;
 174           }
 175
 176         /* TODO print UTF8 decoded text */
 177         if (isascii)
 178           printf(" [%s \"%*.*s\"]",
 179                  tok2str(pppoetag2str, "TAG-0x%x", tag_type),
 180                  tag_len < 80 ? tag_len : 80,
 181                  tag_len < 80 ? tag_len : 80,
 182                  p
 183                  );
 184         else
 185           printf(" [%s UTF8]", tok2str(pppoetag2str, "TAG-0x%x", tag_type));
 186       } else
 187         printf(" [%s]", tok2str(pppoetag2str, "TAG-0x%x", tag_type));
 188
 189       p += tag_len;
 190       /* p points to next tag */
 191     }
 192   } else {
 193 #if 0
 194     /* We now make use of ppp_print() instead, because it has more
 195        comprehensive support for PPP. It also gives us a consistent
 196        output with other protocols like L2TP. */
 197     u_short ptype;
 198     if (pppoe_payload[0] & 0x1) {
 199       ptype = pppoe_payload[0];
 200       pppoe_payload +=1;
 201       pppoe_length  -=1;
 202     } else if (pppoe_payload[1] & 0x1) {
 203       ptype = ntohs(*(u_short *)pppoe_payload);
 204       pppoe_payload +=2;
 205       pppoe_length  -=2;
 206     } else {
 207       printf(" Invalid PPP protocol ID: %x %x", pppoe_payload[0],pppoe_payload[1]);
 208       return;
 209     }
 210     printf(" ");
 211     if (ptype == PPP_IP)
 212       ip_print(pppoe_payload, pppoe_length);
 213     else if (ptype == PPP_LCP)
 214       lcp_print(pppoe_payload, pppoe_length);
 215     else
 216       printf("%s ", tok2str(ppptype2str, "proto-0x%x", ptype));
 217 #endif
 218     printf(" ");
 219     ppp_print(pppoe_payload, pppoe_length);
 220   }
 221   return;
 222 }