]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-eap.c
gre: add support for MikroTik Ethernet-over-IP hack.
[tcpdump] / print-eap.c
index 0d9f62b752403ccfb1a24614f59c2ac8cb69a017..e640e83dd46208610e402f4698d62c5e87b9bdc9 100644 (file)
@@ -42,11 +42,11 @@ struct eap_frame_t {
 };
 
 static const struct tok eap_frame_type_values[] = {
-    { EAP_FRAME_TYPE_PACKET,           "EAP packet" },
-    { EAP_FRAME_TYPE_START,                    "EAPOL start" },
-    { EAP_FRAME_TYPE_LOGOFF,           "EAPOL logoff" },
-    { EAP_FRAME_TYPE_KEY,                      "EAPOL key" },
-    { EAP_FRAME_TYPE_ENCAP_ASF_ALERT,  "Encapsulated ASF alert" },
+    { EAP_FRAME_TYPE_PACKET,           "EAP packet" },
+    { EAP_FRAME_TYPE_START,            "EAPOL start" },
+    { EAP_FRAME_TYPE_LOGOFF,           "EAPOL logoff" },
+    { EAP_FRAME_TYPE_KEY,              "EAPOL key" },
+    { EAP_FRAME_TYPE_ENCAP_ASF_ALERT,  "Encapsulated ASF alert" },
     { 0, NULL}
 };
 
@@ -77,9 +77,9 @@ static const struct tok eap_code_values[] = {
 #define                EAP_TYPE_MD5_CHALLENGE  4
 #define                EAP_TYPE_OTP            5
 #define                EAP_TYPE_GTC            6
-#define                EAP_TYPE_TLS            13              /* RFC 2716 */
+#define                EAP_TYPE_TLS            13              /* RFC 5216 */
 #define                EAP_TYPE_SIM            18              /* RFC 4186 */
-#define                EAP_TYPE_TTLS           21              /* draft-funk-eap-ttls-v0-01.txt */
+#define                EAP_TYPE_TTLS           21              /* RFC 5281, draft-funk-eap-ttls-v0-01.txt */
 #define                EAP_TYPE_AKA            23              /* RFC 4187 */
 #define                EAP_TYPE_FAST           43              /* RFC 4851 */
 #define                EAP_TYPE_EXPANDED_TYPES 254
@@ -89,23 +89,23 @@ static const struct tok eap_type_values[] = {
     { EAP_TYPE_NO_PROPOSED,    "No proposed" },
     { EAP_TYPE_IDENTITY,       "Identity" },
     { EAP_TYPE_NOTIFICATION,    "Notification" },
-    { EAP_TYPE_NAK,            "Nak" },
+    { EAP_TYPE_NAK,            "Nak" },
     { EAP_TYPE_MD5_CHALLENGE,   "MD5-challenge" },
-    { EAP_TYPE_OTP,            "OTP" },
-    { EAP_TYPE_GTC,            "GTC" },
-    { EAP_TYPE_TLS,            "TLS" },
-    { EAP_TYPE_SIM,            "SIM" },
-    { EAP_TYPE_TTLS,           "TTLS" },
-    { EAP_TYPE_AKA,            "AKA" },
-    { EAP_TYPE_FAST,           "FAST" },
+    { EAP_TYPE_OTP,            "OTP" },
+    { EAP_TYPE_GTC,            "GTC" },
+    { EAP_TYPE_TLS,            "TLS" },
+    { EAP_TYPE_SIM,            "SIM" },
+    { EAP_TYPE_TTLS,           "TTLS" },
+    { EAP_TYPE_AKA,            "AKA" },
+    { EAP_TYPE_FAST,           "FAST" },
     { EAP_TYPE_EXPANDED_TYPES,  "Expanded types" },
     { EAP_TYPE_EXPERIMENTAL,    "Experimental" },
     { 0, NULL}
 };
 
-#define EAP_TLS_EXTRACT_BIT_L(x)       (((x)&0x80)>>7)
+#define EAP_TLS_EXTRACT_BIT_L(x)       (((x)&0x80)>>7)
 
-/* RFC 2716 - EAP TLS bits */
+/* RFC 5216 - EAP TLS bits */
 #define EAP_TLS_FLAGS_LEN_INCLUDED             (1 << 7)
 #define EAP_TLS_FLAGS_MORE_FRAGMENTS           (1 << 6)
 #define EAP_TLS_FLAGS_START                    (1 << 5)
@@ -152,26 +152,40 @@ eap_print(netdissect_options *ndo,
           u_int length)
 {
     u_int type, subtype, len;
-    int count;
+    u_int count;
+    const char *sep;
 
-    ND_TCHECK_1(cp);
+    ndo->ndo_protocol = "eap";
     type = GET_U_1(cp);
-    ND_TCHECK_2(cp + 2);
     len = GET_BE_U_2(cp + 2);
-    if(len != length) {
-       goto trunc;
+    if (len != length) {
+        /*
+         * Probably a fragment; in some cases the fragmentation might
+         * not put an EAP header on every packet, if reassembly can
+         * be done without that (e.g., fragmentation to make a message
+         * fit in multiple TLVs in a RADIUS packet).
+         */
+        ND_PRINT("EAP fragment?");
+        return;
     }
     ND_PRINT("%s (%u), id %u, len %u",
             tok2str(eap_code_values, "unknown", type),
             type,
             GET_U_1((cp + 1)),
             len);
+    if (len < 4) {
+        ND_PRINT(" (too short for EAP header)");
+        return;
+    }
 
     ND_TCHECK_LEN(cp, len);
 
     if (type == EAP_REQUEST || type == EAP_RESPONSE) {
         /* RFC 3748 Section 4.1 */
-        ND_TCHECK_1(cp + 4);
+        if (len < 5) {
+            ND_PRINT(" (too short for EAP request/response)");
+            return;
+        }
         subtype = GET_U_1(cp + 4);
         ND_PRINT("\n\t\t Type %s (%u)",
                 tok2str(eap_type_values, "unknown", subtype),
@@ -179,63 +193,81 @@ eap_print(netdissect_options *ndo,
 
         switch (subtype) {
             case EAP_TYPE_IDENTITY:
-                if (len - 5 > 0) {
+                /* According to RFC 3748, the message is optional */
+                if (len > 5) {
                     ND_PRINT(", Identity: ");
-                    (void)nd_printzp(ndo, cp + 5, len - 5, NULL);
+                    nd_printjnp(ndo, cp + 5, len - 5);
                 }
                 break;
 
             case EAP_TYPE_NOTIFICATION:
-                if (len - 5 > 0) {
-                    ND_PRINT(", Notification: ");
-                    (void)nd_printzp(ndo, cp + 5, len - 5, NULL);
+                /* According to RFC 3748, there must be at least one octet of message */
+                if (len < 6) {
+                    ND_PRINT(" (too short for EAP Notification request/response)");
+                    return;
                 }
+                ND_PRINT(", Notification: ");
+                nd_printjnp(ndo, cp + 5, len - 5);
                 break;
 
             case EAP_TYPE_NAK:
-                count = 5;
-
                 /*
                  * one or more octets indicating
                  * the desired authentication
                  * type one octet per type
                  */
-                while (count < (int)len) {
-                    ND_TCHECK_1(cp + count);
-                    ND_PRINT(" %s (%u),",
+                if (len < 6) {
+                    ND_PRINT(" (too short for EAP Legacy NAK request/response)");
+                    return;
+                }
+                sep = "";
+                for (count = 5; count < len; count++) {
+                    ND_PRINT("%s %s (%u)", sep,
                            tok2str(eap_type_values, "unknown", GET_U_1((cp + count))),
                            GET_U_1(cp + count));
-                    count++;
+                    sep = ",";
                 }
                 break;
 
             case EAP_TYPE_TTLS:
             case EAP_TYPE_TLS:
-                ND_TCHECK_1(cp + 5);
+                if (len < 6) {
+                    ND_PRINT(" (too short for EAP TLS/TTLS request/response)");
+                    return;
+                }
                 if (subtype == EAP_TYPE_TTLS)
                     ND_PRINT(" TTLSv%u",
                            EAP_TTLS_VERSION(GET_U_1((cp + 5))));
-                ND_PRINT(" flags [%s] 0x%02x,",
+                ND_PRINT(" flags [%s] 0x%02x",
                        bittok2str(eap_tls_flags_values, "none", GET_U_1((cp + 5))),
                        GET_U_1(cp + 5));
 
                 if (EAP_TLS_EXTRACT_BIT_L(GET_U_1(cp + 5))) {
-                    ND_TCHECK_4(cp + 6);
-                    ND_PRINT(" len %u", GET_BE_U_4(cp + 6));
+                    if (len < 10) {
+                        ND_PRINT(" (too short for EAP TLS/TTLS request/response with length)");
+                        return;
+                    }
+                    ND_PRINT(", len %u", GET_BE_U_4(cp + 6));
                 }
                 break;
 
             case EAP_TYPE_FAST:
-                ND_TCHECK_1(cp + 5);
+                if (len < 6) {
+                    ND_PRINT(" (too short for EAP FAST request/response)");
+                    return;
+                }
                 ND_PRINT(" FASTv%u",
                        EAP_TTLS_VERSION(GET_U_1((cp + 5))));
-                ND_PRINT(" flags [%s] 0x%02x,",
+                ND_PRINT(" flags [%s] 0x%02x",
                        bittok2str(eap_tls_flags_values, "none", GET_U_1((cp + 5))),
                        GET_U_1(cp + 5));
 
                 if (EAP_TLS_EXTRACT_BIT_L(GET_U_1(cp + 5))) {
-                    ND_TCHECK_4(cp + 6);
-                    ND_PRINT(" len %u", GET_BE_U_4(cp + 6));
+                    if (len < 10) {
+                        ND_PRINT(" (too short for EAP FAST request/response with length)");
+                        return;
+                    }
+                    ND_PRINT(", len %u", GET_BE_U_4(cp + 6));
                 }
 
                 /* FIXME - TLV attributes follow */
@@ -243,8 +275,11 @@ eap_print(netdissect_options *ndo,
 
             case EAP_TYPE_AKA:
             case EAP_TYPE_SIM:
-                ND_TCHECK_1(cp + 5);
-                ND_PRINT(" subtype [%s] 0x%02x,",
+                if (len < 6) {
+                    ND_PRINT(" (too short for EAP SIM/AKA request/response)");
+                    return;
+                }
+                ND_PRINT(" subtype [%s] 0x%02x",
                        tok2str(eap_aka_subtype_values, "unknown", GET_U_1((cp + 5))),
                        GET_U_1(cp + 5));
 
@@ -263,7 +298,6 @@ eap_print(netdissect_options *ndo,
     return;
 trunc:
     nd_print_trunc(ndo);
-    return;
 }
 
 void