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

   1 /*
   2  * Copyright (c) 2004 - Michael Richardson <mcr@xelerance.com>
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that: (1) source code distributions
   6  * retain the above copyright notice and this paragraph in its entirety, (2)
   7  * distributions including binary code include the above copyright notice and
   8  * this paragraph in its entirety in the documentation or other materials
   9  * provided with the distribution, and (3) all advertising materials mentioning
  10  * features or use of this software display the following acknowledgement:
  11  * ``This product includes software developed by the University of California,
  12  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  13  * the University nor the names of its contributors may be used to endorse
  14  * or promote products derived from this software without specific prior
  15  * written permission.
  16  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  17  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  19  *
  20  * Format and print EAP packets.
  21  *
  22  */
  23
  24 #ifndef lint
  25 static const char rcsid[] _U_ =
  26     "@(#) $Header: /tcpdump/master/tcpdump/print-eap.c,v 1.4 2007-10-04 08:34:28 hannes Exp $";
  27 #endif
  28
  29 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #include <tcpdump-stdinc.h>
  34
  35 #include <stdio.h>
  36 #include <string.h>
  37
  38 #include "netdissect.h"
  39 #include "interface.h"
  40 #include "addrtoname.h"
  41 #include "extract.h"
  42 #include "ether.h"
  43
  44 #define EAP_FRAME_TYPE_PACKET           0
  45 #define EAP_FRAME_TYPE_START            1
  46 #define EAP_FRAME_TYPE_LOGOFF           2
  47 #define EAP_FRAME_TYPE_KEY              3
  48 #define EAP_FRAME_TYPE_ENCAP_ASF_ALERT  4
  49
  50 struct eap_frame_t {
  51     unsigned char   version;
  52     unsigned char   type;
  53     unsigned char   length[2];
  54 };
  55
  56 static const struct tok eap_frame_type_values[] = {
  57     { EAP_FRAME_TYPE_PACKET,            "EAP packet" },
  58     { EAP_FRAME_TYPE_START,             "EAPOL start" },
  59     { EAP_FRAME_TYPE_LOGOFF,            "EAPOL logoff" },
  60     { EAP_FRAME_TYPE_KEY,               "EAPOL key" },
  61     { EAP_FRAME_TYPE_ENCAP_ASF_ALERT,   "Encapsulated ASF alert" },
  62     { 0, NULL}
  63 };
  64
  65 /* RFC 3748 */
  66 struct eap_packet_t {
  67     unsigned char       code;
  68     unsigned char       id;
  69     unsigned char       length[2];
  70 };
  71
  72 #define         EAP_REQUEST     1
  73 #define         EAP_RESPONSE    2
  74 #define         EAP_SUCCESS     3
  75 #define         EAP_FAILURE     4
  76
  77 static const struct tok eap_code_values[] = {
  78     { EAP_REQUEST,      "Request" },
  79     { EAP_RESPONSE,     "Response" },
  80     { EAP_SUCCESS,      "Success" },
  81     { EAP_FAILURE,      "Failure" },
  82     { 0, NULL}
  83 };
  84
  85 #define         EAP_TYPE_NO_PROPOSED    0
  86 #define         EAP_TYPE_IDENTITY       1
  87 #define         EAP_TYPE_NOTIFICATION   2
  88 #define         EAP_TYPE_NAK            3
  89 #define         EAP_TYPE_MD5_CHALLENGE  4
  90 #define         EAP_TYPE_OTP            5
  91 #define         EAP_TYPE_GTC            6
  92 #define         EAP_TYPE_EXPANDED_TYPES 254
  93 #define         EAP_TYPE_EXPERIMENTAL   255
  94
  95 static const struct tok eap_type_values[] = {
  96     { EAP_TYPE_NO_PROPOSED,     "No proposed" },
  97     { EAP_TYPE_IDENTITY,        "Identity" },
  98     { EAP_TYPE_NOTIFICATION,    "Notification" },
  99     { EAP_TYPE_NAK,             "Nak" },
 100     { EAP_TYPE_MD5_CHALLENGE,   "MD5-challenge" },
 101     { EAP_TYPE_OTP,             "OTP" },
 102     { EAP_TYPE_GTC,             "GTC" },
 103     { EAP_TYPE_EXPANDED_TYPES,  "Expanded types" },
 104     { EAP_TYPE_EXPERIMENTAL,    "Experimental" },
 105     { 0, NULL}
 106 };
 107
 108 /*
 109  * Print EAP requests / responses
 110  */
 111 void
 112 eap_print(netdissect_options *ndo _U_,
 113           register const u_char *cp,
 114           u_int length _U_)
 115 {
 116     const struct eap_frame_t *eap;
 117     const u_char *tptr;
 118     u_int tlen, type, subtype;
 119     int count=0, len;
 120
 121     tptr = cp;
 122     tlen = length;
 123     eap = (const struct eap_frame_t *)cp;
 124     TCHECK(*eap);
 125
 126     /* in non-verbose mode just lets print the basic info */
 127     if (vflag < 1) {
 128         printf("%s (%u) v%u, len %u",
 129                tok2str(eap_frame_type_values, "unknown", eap->type),
 130                eap->type,
 131                eap->version,
 132                EXTRACT_16BITS(eap->length));
 133         return;
 134     }
 135
 136     printf("%s (%u) v%u, len %u",
 137            tok2str(eap_frame_type_values, "unknown", eap->type),
 138            eap->type,
 139            eap->version,
 140            EXTRACT_16BITS(eap->length));
 141
 142     tptr += sizeof(const struct eap_frame_t);
 143     tlen -= sizeof(const struct eap_frame_t);
 144
 145     switch (eap->type) {
 146     case EAP_FRAME_TYPE_PACKET:
 147         type = *(tptr);
 148         len = EXTRACT_16BITS(tptr+2);
 149         printf(", %s (%u), id %u, len %u",
 150                tok2str(eap_code_values, "unknown", type),
 151                type,
 152                *(tptr+1),
 153                len);
 154
 155         if (!TTEST2(*tptr, len))
 156             goto trunc;
 157
 158         if (type <= 2) { /* For EAP_REQUEST and EAP_RESPONSE only */
 159             subtype = *(tptr+4);
 160             printf("\n\t\t Type %s (%u)",
 161                    tok2str(eap_type_values, "unknown", *(tptr+4)),
 162                    *(tptr+4));
 163
 164             switch (subtype) {
 165             case EAP_TYPE_IDENTITY:
 166                 if (len - 5 > 0) {
 167                     printf(", Identity: ");
 168                     safeputs((const char *)tptr+5, len-5);
 169                 }
 170                 break;
 171
 172             case EAP_TYPE_NOTIFICATION:
 173                 if (len - 5 > 0) {
 174                     printf(", Notification: ");
 175                     safeputs((const char *)tptr+5, len-5);
 176                 }
 177                 break;
 178
 179             case EAP_TYPE_NAK:
 180                 count = 5;
 181
 182                 /*
 183                  * one or more octets indicating
 184                  * the desired authentication
 185                  * type one octet per type
 186                  */
 187                 while (count < len) {
 188                     printf(" %s (%u),",
 189                            tok2str(eap_type_values, "unknown", *(tptr+count)),
 190                            *(tptr+count));
 191                     count++;
 192                 }
 193                 break;
 194
 195             case EAP_TYPE_MD5_CHALLENGE:
 196             case EAP_TYPE_OTP:
 197             case EAP_TYPE_GTC:
 198             case EAP_TYPE_EXPANDED_TYPES:
 199             case EAP_TYPE_EXPERIMENTAL:
 200             default:
 201                 break;
 202             }
 203         }
 204         break;
 205
 206     case EAP_FRAME_TYPE_LOGOFF:
 207     case EAP_FRAME_TYPE_ENCAP_ASF_ALERT:
 208     default:
 209         break;
 210     }
 211     return;
 212
 213  trunc:
 214     printf("\n\t[|EAP]");
 215 }
 216
 217 /*
 218  * Local Variables:
 219  * c-basic-offset: 4
 220  * End:
 221  */