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 1.9 2000-09-28 06:43:06 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 struct mbuf;
  36 struct rtentry;
  37
  38 #include <netinet/in.h>
  39
  40 #include <stdio.h>
  41 #include <string.h>
  42
  43 #include "interface.h"
  44 #include "addrtoname.h"
  45 #include "ppp.h"
  46 #include "ethertype.h"
  47 #include "ether.h"
  48 #include "extract.h"                    /* must come after interface.h */
  49
  50 /* Codes */
  51 enum {
  52   PPPOE_PADI = 0x09,
  53   PPPOE_PADO = 0x07,
  54   PPPOE_PADR = 0x19,
  55   PPPOE_PADS = 0x65,
  56   PPPOE_PADT = 0xa7
  57 };
  58
  59 static struct tok pppoecode2str[] = {
  60   { PPPOE_PADI, "PADI"},
  61   { PPPOE_PADO, "PADO"},
  62   { PPPOE_PADR, "PADR"},
  63   { PPPOE_PADS, "PADS"},
  64   { PPPOE_PADT, "PADT"},
  65   { 0, ""}, /* PPP Data */
  66   { 0, NULL }
  67 };
  68
  69 /* Tags */
  70 enum {
  71   PPPOE_EOL = 0,
  72   PPPOE_SERVICE_NAME = 0x0101,
  73   PPPOE_AC_NAME = 0x0102,
  74   PPPOE_HOST_UNIQ = 0x0103,
  75   PPPOE_AC_COOKIE = 0x0104,
  76   PPPOE_VENDOR = 0x0105,
  77   PPPOE_RELAY_SID = 0x0110,
  78   PPPOE_SERVICE_NAME_ERROR = 0x0201,
  79   PPPOE_AC_SYSTEM_ERROR = 0x0202,
  80   PPPOE_GENERIC_ERROR = 0x0203
  81 };
  82
  83 static struct tok pppoetag2str[] = {
  84   { PPPOE_EOL, "EOL"},
  85   { PPPOE_SERVICE_NAME, "Service-Name" },
  86   { PPPOE_AC_NAME, "AC-Name" },
  87   { PPPOE_HOST_UNIQ, "Host-Uniq" },
  88   { PPPOE_AC_COOKIE, "AC-Cookie" },
  89   { PPPOE_VENDOR, "Vendor-Specific" },
  90   { PPPOE_RELAY_SID, "Relay-Session-ID" },
  91   { PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" },
  92   { PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" },
  93   { PPPOE_GENERIC_ERROR, "Generic-Error" },
  94   { 0, NULL}
  95 };
  96
  97 #define PPPOE_HDRLEN 6
  98
  99 void
 100 pppoe_print(register const u_char *bp, u_int length)
 101 {
 102   register const struct ether_header *eh;
 103   register u_short pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid, pppoe_length;
 104   const u_char *pppoe_packet, *pppoe_payload;
 105
 106   eh = (struct ether_header *)packetp;
 107   pppoe_packet = packetp+sizeof(struct ether_header);
 108   if (pppoe_packet > snapend) {
 109     printf("[|pppoe]");
 110     return;
 111   }
 112
 113   pppoe_ver  = (pppoe_packet[0]&0xF0)>>4;
 114   pppoe_type  = (pppoe_packet[0]&0x0F);
 115   pppoe_code = (pppoe_packet[1]);
 116   pppoe_sessionid = (EXTRACT_16BITS(pppoe_packet+2));
 117   pppoe_length    = (EXTRACT_16BITS(pppoe_packet+4));
 118   pppoe_payload = pppoe_packet+6;
 119
 120   if (snapend < pppoe_payload) {
 121     printf(" truncated PPPoE");
 122     return;
 123   }
 124
 125   if (pppoe_ver != 1) {
 126     printf(" [ver %d]",pppoe_ver);
 127   }
 128   if (pppoe_type != 1) {
 129     printf(" [type %d]",pppoe_type);
 130   }
 131
 132   printf("PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code));
 133   if (pppoe_code == PPPOE_PADI && pppoe_length > 1484-PPPOE_HDRLEN) {
 134     printf(" [len %d!]",pppoe_length);
 135   }
 136   if (pppoe_sessionid) {
 137     printf(" [ses 0x%x]",pppoe_sessionid);
 138   }
 139
 140   if (pppoe_payload + pppoe_length < snapend) {
 141     /*
 142     printf(" [length %d (%d extra bytes)]", pppoe_length, snapend-pppoe_payload-pppoe_length);
 143     {
 144       const u_char *x = pppoe_payload+pppoe_length;
 145       default_print(x, snapend - x);
 146     }
 147     */
 148     snapend = pppoe_payload+pppoe_length;
 149   }
 150
 151
 152   if (pppoe_code) {
 153     /* PPP session packets don't contain tags */
 154     u_short tag_type = 0xffff, tag_len;
 155     const u_char *p = pppoe_payload;
 156
 157     /* loop invariant:
 158        p points to next tag,
 159        tag_type is previous tag or 0xffff for first iteration
 160     */
 161     while (tag_type &&
 162            p+4 < pppoe_payload + length &&
 163            p+4 < snapend) {
 164       tag_type = EXTRACT_16BITS(p);
 165       tag_len  = EXTRACT_16BITS(p+2);
 166       p += 4;
 167       /* p points to tag_value */
 168
 169       if (tag_len) {
 170         int isascii = 1;
 171         const u_char *v = p;
 172
 173         for (v=p; v<p+tag_len; v++)
 174           if (*v >= 127 || *v < 32) {
 175             isascii = 0;
 176             break;
 177           }
 178
 179         /* TODO print UTF8 decoded text */
 180         if (isascii)
 181           printf(" [%s \"%*.*s\"]",
 182                  tok2str(pppoetag2str, "TAG-0x%x", tag_type),
 183                  tag_len < 80 ? tag_len : 80,
 184                  tag_len < 80 ? tag_len : 80,
 185                  p
 186                  );
 187         else
 188           printf(" [%s UTF8]", tok2str(pppoetag2str, "TAG-0x%x", tag_type));
 189       } else
 190         printf(" [%s]", tok2str(pppoetag2str, "TAG-0x%x", tag_type));
 191
 192       p += tag_len;
 193       /* p points to next tag */
 194     }
 195   } else {
 196 #if 0
 197     /* We now make use of ppp_print() instead, because it has more
 198        comprehensive support for PPP. It also gives us a consistent
 199        output with other protocols like L2TP. */
 200     u_short ptype;
 201     if (pppoe_payload[0] & 0x1) {
 202       ptype = pppoe_payload[0];
 203       pppoe_payload +=1;
 204       pppoe_length  -=1;
 205     } else if (pppoe_payload[1] & 0x1) {
 206       ptype = ntohs(*(u_short *)pppoe_payload);
 207       pppoe_payload +=2;
 208       pppoe_length  -=2;
 209     } else {
 210       printf(" Invalid PPP protocol ID: %x %x", pppoe_payload[0],pppoe_payload[1]);
 211       return;
 212     }
 213     printf(" ");
 214     if (ptype == PPP_IP)
 215       ip_print(pppoe_payload, pppoe_length);
 216     else if (ptype == PPP_LCP)
 217       lcp_print(pppoe_payload, pppoe_length);
 218     else
 219       printf("%s ", tok2str(ppptype2str, "proto-0x%x", ptype));
 220 #endif
 221     printf(" ");
 222     ppp_print(pppoe_payload);
 223   }
 224   return;
 225 }