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 #ifdef HAVE_CONFIG_H
  25 #include "config.h"
  26 #endif
  27
  28 #include <tcpdump-stdinc.h>
  29
  30 #include <stdio.h>
  31 #include <string.h>
  32
  33 #include "netdissect.h"
  34 #include "interface.h"
  35 #include "addrtoname.h"
  36 #include "extract.h"
  37 #include "ether.h"
  38
  39 #define EAP_FRAME_TYPE_PACKET           0
  40 #define EAP_FRAME_TYPE_START            1
  41 #define EAP_FRAME_TYPE_LOGOFF           2
  42 #define EAP_FRAME_TYPE_KEY              3
  43 #define EAP_FRAME_TYPE_ENCAP_ASF_ALERT  4
  44
  45 struct eap_frame_t {
  46     unsigned char   version;
  47     unsigned char   type;
  48     unsigned char   length[2];
  49 };
  50
  51 static const struct tok eap_frame_type_values[] = {
  52     { EAP_FRAME_TYPE_PACKET,            "EAP packet" },
  53     { EAP_FRAME_TYPE_START,             "EAPOL start" },
  54     { EAP_FRAME_TYPE_LOGOFF,            "EAPOL logoff" },
  55     { EAP_FRAME_TYPE_KEY,               "EAPOL key" },
  56     { EAP_FRAME_TYPE_ENCAP_ASF_ALERT,   "Encapsulated ASF alert" },
  57     { 0, NULL}
  58 };
  59
  60 /* RFC 3748 */
  61 struct eap_packet_t {
  62     unsigned char       code;
  63     unsigned char       id;
  64     unsigned char       length[2];
  65 };
  66
  67 #define         EAP_REQUEST     1
  68 #define         EAP_RESPONSE    2
  69 #define         EAP_SUCCESS     3
  70 #define         EAP_FAILURE     4
  71
  72 static const struct tok eap_code_values[] = {
  73     { EAP_REQUEST,      "Request" },
  74     { EAP_RESPONSE,     "Response" },
  75     { EAP_SUCCESS,      "Success" },
  76     { EAP_FAILURE,      "Failure" },
  77     { 0, NULL}
  78 };
  79
  80 #define         EAP_TYPE_NO_PROPOSED    0
  81 #define         EAP_TYPE_IDENTITY       1
  82 #define         EAP_TYPE_NOTIFICATION   2
  83 #define         EAP_TYPE_NAK            3
  84 #define         EAP_TYPE_MD5_CHALLENGE  4
  85 #define         EAP_TYPE_OTP            5
  86 #define         EAP_TYPE_GTC            6
  87 #define         EAP_TYPE_TLS            13              /* RFC 2716 */
  88 #define         EAP_TYPE_SIM            18              /* RFC 4186 */
  89 #define         EAP_TYPE_TTLS           21              /* draft-funk-eap-ttls-v0-01.txt */
  90 #define         EAP_TYPE_AKA            23              /* RFC 4187 */
  91 #define         EAP_TYPE_FAST           43              /* RFC 4851 */
  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_TLS,             "TLS" },
 104     { EAP_TYPE_SIM,             "SIM" },
 105     { EAP_TYPE_TTLS,            "TTLS" },
 106     { EAP_TYPE_AKA,             "AKA" },
 107     { EAP_TYPE_FAST,            "FAST" },
 108     { EAP_TYPE_EXPANDED_TYPES,  "Expanded types" },
 109     { EAP_TYPE_EXPERIMENTAL,    "Experimental" },
 110     { 0, NULL}
 111 };
 112
 113 #define EAP_TLS_EXTRACT_BIT_L(x)        (((x)&0x80)>>7)
 114
 115 /* RFC 2716 - EAP TLS bits */
 116 #define EAP_TLS_FLAGS_LEN_INCLUDED              (1 << 7)
 117 #define EAP_TLS_FLAGS_MORE_FRAGMENTS            (1 << 6)
 118 #define EAP_TLS_FLAGS_START                     (1 << 5)
 119
 120 static const struct tok eap_tls_flags_values[] = {
 121         { EAP_TLS_FLAGS_LEN_INCLUDED, "L bit" },
 122         { EAP_TLS_FLAGS_MORE_FRAGMENTS, "More fragments bit"},
 123         { EAP_TLS_FLAGS_START, "Start bit"},
 124         { 0, NULL}
 125 };
 126
 127 #define EAP_TTLS_VERSION(x)             ((x)&0x07)
 128
 129 /* EAP-AKA and EAP-SIM - RFC 4187 */
 130 #define EAP_AKA_CHALLENGE               1
 131 #define EAP_AKA_AUTH_REJECT             2
 132 #define EAP_AKA_SYNC_FAILURE            4
 133 #define EAP_AKA_IDENTITY                5
 134 #define EAP_SIM_START                   10
 135 #define EAP_SIM_CHALLENGE               11
 136 #define EAP_AKA_NOTIFICATION            12
 137 #define EAP_AKA_REAUTH                  13
 138 #define EAP_AKA_CLIENT_ERROR            14
 139
 140 static const struct tok eap_aka_subtype_values[] = {
 141     { EAP_AKA_CHALLENGE,        "Challenge" },
 142     { EAP_AKA_AUTH_REJECT,      "Auth reject" },
 143     { EAP_AKA_SYNC_FAILURE,     "Sync failure" },
 144     { EAP_AKA_IDENTITY,         "Identity" },
 145     { EAP_SIM_START,            "Start" },
 146     { EAP_SIM_CHALLENGE,        "Challenge" },
 147     { EAP_AKA_NOTIFICATION,     "Notification" },
 148     { EAP_AKA_REAUTH,           "Reauth" },
 149     { EAP_AKA_CLIENT_ERROR,     "Client error" },
 150     { 0, NULL}
 151 };
 152
 153 /*
 154  * Print EAP requests / responses
 155  */
 156 void
 157 eap_print(netdissect_options *ndo _U_,
 158           register const u_char *cp,
 159           u_int length _U_)
 160 {
 161     const struct eap_frame_t *eap;
 162     const u_char *tptr;
 163     u_int tlen, type, subtype;
 164     int count=0, len;
 165
 166     tptr = cp;
 167     tlen = length;
 168     eap = (const struct eap_frame_t *)cp;
 169     TCHECK(*eap);
 170
 171     /* in non-verbose mode just lets print the basic info */
 172     if (vflag < 1) {
 173         printf("%s (%u) v%u, len %u",
 174                tok2str(eap_frame_type_values, "unknown", eap->type),
 175                eap->type,
 176                eap->version,
 177                EXTRACT_16BITS(eap->length));
 178         return;
 179     }
 180
 181     printf("%s (%u) v%u, len %u",
 182            tok2str(eap_frame_type_values, "unknown", eap->type),
 183            eap->type,
 184            eap->version,
 185            EXTRACT_16BITS(eap->length));
 186
 187     tptr += sizeof(const struct eap_frame_t);
 188     tlen -= sizeof(const struct eap_frame_t);
 189
 190     switch (eap->type) {
 191     case EAP_FRAME_TYPE_PACKET:
 192         type = *(tptr);
 193         len = EXTRACT_16BITS(tptr+2);
 194         printf(", %s (%u), id %u, len %u",
 195                tok2str(eap_code_values, "unknown", type),
 196                type,
 197                *(tptr+1),
 198                len);
 199
 200         if (!TTEST2(*tptr, len))
 201             goto trunc;
 202
 203         if (type <= 2) { /* For EAP_REQUEST and EAP_RESPONSE only */
 204             subtype = *(tptr+4);
 205             printf("\n\t\t Type %s (%u)",
 206                    tok2str(eap_type_values, "unknown", *(tptr+4)),
 207                    *(tptr+4));
 208
 209             switch (subtype) {
 210             case EAP_TYPE_IDENTITY:
 211                 if (len - 5 > 0) {
 212                     printf(", Identity: ");
 213                     safeputs((const char *)tptr+5, len-5);
 214                 }
 215                 break;
 216
 217             case EAP_TYPE_NOTIFICATION:
 218                 if (len - 5 > 0) {
 219                     printf(", Notification: ");
 220                     safeputs((const char *)tptr+5, len-5);
 221                 }
 222                 break;
 223
 224             case EAP_TYPE_NAK:
 225                 count = 5;
 226
 227                 /*
 228                  * one or more octets indicating
 229                  * the desired authentication
 230                  * type one octet per type
 231                  */
 232                 while (count < len) {
 233                     printf(" %s (%u),",
 234                            tok2str(eap_type_values, "unknown", *(tptr+count)),
 235                            *(tptr+count));
 236                     count++;
 237                 }
 238                 break;
 239
 240             case EAP_TYPE_TTLS:
 241                 printf(" TTLSv%u",
 242                        EAP_TTLS_VERSION(*(tptr+5))); /* fall through */
 243             case EAP_TYPE_TLS:
 244                 printf(" flags [%s] 0x%02x,",
 245                        bittok2str(eap_tls_flags_values, "none", *(tptr+5)),
 246                        *(tptr+5));
 247
 248                 if (EAP_TLS_EXTRACT_BIT_L(*(tptr+5))) {
 249                     printf(" len %u", EXTRACT_32BITS(tptr+6));
 250                 }
 251                 break;
 252
 253             case EAP_TYPE_FAST:
 254                 printf(" FASTv%u",
 255                        EAP_TTLS_VERSION(*(tptr+5)));
 256                 printf(" flags [%s] 0x%02x,",
 257                        bittok2str(eap_tls_flags_values, "none", *(tptr+5)),
 258                        *(tptr+5));
 259
 260                 if (EAP_TLS_EXTRACT_BIT_L(*(tptr+5))) {
 261                     printf(" len %u", EXTRACT_32BITS(tptr+6));
 262                 }
 263
 264                 /* FIXME - TLV attributes follow */
 265                 break;
 266
 267             case EAP_TYPE_AKA:
 268             case EAP_TYPE_SIM:
 269                 printf(" subtype [%s] 0x%02x,",
 270                        tok2str(eap_aka_subtype_values, "unknown", *(tptr+5)),
 271                        *(tptr+5));
 272
 273                 /* FIXME - TLV attributes follow */
 274                 break;
 275
 276             case EAP_TYPE_MD5_CHALLENGE:
 277             case EAP_TYPE_OTP:
 278             case EAP_TYPE_GTC:
 279             case EAP_TYPE_EXPANDED_TYPES:
 280             case EAP_TYPE_EXPERIMENTAL:
 281             default:
 282                 break;
 283             }
 284         }
 285         break;
 286
 287     case EAP_FRAME_TYPE_LOGOFF:
 288     case EAP_FRAME_TYPE_ENCAP_ASF_ALERT:
 289     default:
 290         break;
 291     }
 292     return;
 293
 294  trunc:
 295     printf("\n\t[|EAP]");
 296 }
 297
 298 /*
 299  * Local Variables:
 300  * c-basic-offset: 4
 301  * End:
 302  */