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-rw-r--r--print-l2tp.c859
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diff --git a/print-l2tp.c b/print-l2tp.c
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+/*
+ * Copyright (c) 1991, 1993, 1994, 1995, 1996, 1997
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that: (1) source code distributions
+ * retain the above copyright notice and this paragraph in its entirety, (2)
+ * distributions including binary code include the above copyright notice and
+ * this paragraph in its entirety in the documentation or other materials
+ * provided with the distribution, and (3) all advertising materials mentioning
+ * features or use of this software display the following acknowledgement:
+ * ``This product includes software developed by the University of California,
+ * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
+ * the University nor the names of its contributors may be used to endorse
+ * or promote products derived from this software without specific prior
+ * written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * L2TP support contributed by Motonori Shindo (mshindo@mshindo.net)
+ */
+
+/* \summary: Layer Two Tunneling Protocol (L2TP) printer */
+
+/* specification: RFC 2661 */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#include "netdissect.h"
+#include "extract.h"
+
+#define L2TP_FLAG_TYPE 0x8000 /* Type (0=Data, 1=Control) */
+#define L2TP_FLAG_LENGTH 0x4000 /* Length */
+#define L2TP_FLAG_SEQUENCE 0x0800 /* Sequence */
+#define L2TP_FLAG_OFFSET 0x0200 /* Offset */
+#define L2TP_FLAG_PRIORITY 0x0100 /* Priority */
+
+#define L2TP_VERSION_MASK 0x000f /* Version Mask */
+#define L2TP_VERSION_L2F 0x0001 /* L2F */
+#define L2TP_VERSION_L2TP 0x0002 /* L2TP */
+
+#define L2TP_AVP_HDR_FLAG_MANDATORY 0x8000 /* Mandatory Flag */
+#define L2TP_AVP_HDR_FLAG_HIDDEN 0x4000 /* Hidden Flag */
+#define L2TP_AVP_HDR_LEN_MASK 0x03ff /* Length Mask */
+
+#define L2TP_FRAMING_CAP_SYNC_MASK 0x00000001 /* Synchronous */
+#define L2TP_FRAMING_CAP_ASYNC_MASK 0x00000002 /* Asynchronous */
+
+#define L2TP_FRAMING_TYPE_SYNC_MASK 0x00000001 /* Synchronous */
+#define L2TP_FRAMING_TYPE_ASYNC_MASK 0x00000002 /* Asynchronous */
+
+#define L2TP_BEARER_CAP_DIGITAL_MASK 0x00000001 /* Digital */
+#define L2TP_BEARER_CAP_ANALOG_MASK 0x00000002 /* Analog */
+
+#define L2TP_BEARER_TYPE_DIGITAL_MASK 0x00000001 /* Digital */
+#define L2TP_BEARER_TYPE_ANALOG_MASK 0x00000002 /* Analog */
+
+/* Authen Type */
+#define L2TP_AUTHEN_TYPE_RESERVED 0x0000 /* Reserved */
+#define L2TP_AUTHEN_TYPE_TEXTUAL 0x0001 /* Textual username/password exchange */
+#define L2TP_AUTHEN_TYPE_CHAP 0x0002 /* PPP CHAP */
+#define L2TP_AUTHEN_TYPE_PAP 0x0003 /* PPP PAP */
+#define L2TP_AUTHEN_TYPE_NO_AUTH 0x0004 /* No Authentication */
+#define L2TP_AUTHEN_TYPE_MSCHAPv1 0x0005 /* MSCHAPv1 */
+
+#define L2TP_PROXY_AUTH_ID_MASK 0x00ff
+
+
+#define L2TP_MSGTYPE_SCCRQ 1 /* Start-Control-Connection-Request */
+#define L2TP_MSGTYPE_SCCRP 2 /* Start-Control-Connection-Reply */
+#define L2TP_MSGTYPE_SCCCN 3 /* Start-Control-Connection-Connected */
+#define L2TP_MSGTYPE_STOPCCN 4 /* Stop-Control-Connection-Notification */
+#define L2TP_MSGTYPE_HELLO 6 /* Hello */
+#define L2TP_MSGTYPE_OCRQ 7 /* Outgoing-Call-Request */
+#define L2TP_MSGTYPE_OCRP 8 /* Outgoing-Call-Reply */
+#define L2TP_MSGTYPE_OCCN 9 /* Outgoing-Call-Connected */
+#define L2TP_MSGTYPE_ICRQ 10 /* Incoming-Call-Request */
+#define L2TP_MSGTYPE_ICRP 11 /* Incoming-Call-Reply */
+#define L2TP_MSGTYPE_ICCN 12 /* Incoming-Call-Connected */
+#define L2TP_MSGTYPE_CDN 14 /* Call-Disconnect-Notify */
+#define L2TP_MSGTYPE_WEN 15 /* WAN-Error-Notify */
+#define L2TP_MSGTYPE_SLI 16 /* Set-Link-Info */
+
+static const struct tok l2tp_msgtype2str[] = {
+ { L2TP_MSGTYPE_SCCRQ, "SCCRQ" },
+ { L2TP_MSGTYPE_SCCRP, "SCCRP" },
+ { L2TP_MSGTYPE_SCCCN, "SCCCN" },
+ { L2TP_MSGTYPE_STOPCCN, "StopCCN" },
+ { L2TP_MSGTYPE_HELLO, "HELLO" },
+ { L2TP_MSGTYPE_OCRQ, "OCRQ" },
+ { L2TP_MSGTYPE_OCRP, "OCRP" },
+ { L2TP_MSGTYPE_OCCN, "OCCN" },
+ { L2TP_MSGTYPE_ICRQ, "ICRQ" },
+ { L2TP_MSGTYPE_ICRP, "ICRP" },
+ { L2TP_MSGTYPE_ICCN, "ICCN" },
+ { L2TP_MSGTYPE_CDN, "CDN" },
+ { L2TP_MSGTYPE_WEN, "WEN" },
+ { L2TP_MSGTYPE_SLI, "SLI" },
+ { 0, NULL }
+};
+
+#define L2TP_AVP_MSGTYPE 0 /* Message Type */
+#define L2TP_AVP_RESULT_CODE 1 /* Result Code */
+#define L2TP_AVP_PROTO_VER 2 /* Protocol Version */
+#define L2TP_AVP_FRAMING_CAP 3 /* Framing Capabilities */
+#define L2TP_AVP_BEARER_CAP 4 /* Bearer Capabilities */
+#define L2TP_AVP_TIE_BREAKER 5 /* Tie Breaker */
+#define L2TP_AVP_FIRM_VER 6 /* Firmware Revision */
+#define L2TP_AVP_HOST_NAME 7 /* Host Name */
+#define L2TP_AVP_VENDOR_NAME 8 /* Vendor Name */
+#define L2TP_AVP_ASSND_TUN_ID 9 /* Assigned Tunnel ID */
+#define L2TP_AVP_RECV_WIN_SIZE 10 /* Receive Window Size */
+#define L2TP_AVP_CHALLENGE 11 /* Challenge */
+#define L2TP_AVP_Q931_CC 12 /* Q.931 Cause Code */
+#define L2TP_AVP_CHALLENGE_RESP 13 /* Challenge Response */
+#define L2TP_AVP_ASSND_SESS_ID 14 /* Assigned Session ID */
+#define L2TP_AVP_CALL_SER_NUM 15 /* Call Serial Number */
+#define L2TP_AVP_MINIMUM_BPS 16 /* Minimum BPS */
+#define L2TP_AVP_MAXIMUM_BPS 17 /* Maximum BPS */
+#define L2TP_AVP_BEARER_TYPE 18 /* Bearer Type */
+#define L2TP_AVP_FRAMING_TYPE 19 /* Framing Type */
+#define L2TP_AVP_PACKET_PROC_DELAY 20 /* Packet Processing Delay (OBSOLETE) */
+#define L2TP_AVP_CALLED_NUMBER 21 /* Called Number */
+#define L2TP_AVP_CALLING_NUMBER 22 /* Calling Number */
+#define L2TP_AVP_SUB_ADDRESS 23 /* Sub-Address */
+#define L2TP_AVP_TX_CONN_SPEED 24 /* (Tx) Connect Speed */
+#define L2TP_AVP_PHY_CHANNEL_ID 25 /* Physical Channel ID */
+#define L2TP_AVP_INI_RECV_LCP 26 /* Initial Received LCP CONFREQ */
+#define L2TP_AVP_LAST_SENT_LCP 27 /* Last Sent LCP CONFREQ */
+#define L2TP_AVP_LAST_RECV_LCP 28 /* Last Received LCP CONFREQ */
+#define L2TP_AVP_PROXY_AUTH_TYPE 29 /* Proxy Authen Type */
+#define L2TP_AVP_PROXY_AUTH_NAME 30 /* Proxy Authen Name */
+#define L2TP_AVP_PROXY_AUTH_CHAL 31 /* Proxy Authen Challenge */
+#define L2TP_AVP_PROXY_AUTH_ID 32 /* Proxy Authen ID */
+#define L2TP_AVP_PROXY_AUTH_RESP 33 /* Proxy Authen Response */
+#define L2TP_AVP_CALL_ERRORS 34 /* Call Errors */
+#define L2TP_AVP_ACCM 35 /* ACCM */
+#define L2TP_AVP_RANDOM_VECTOR 36 /* Random Vector */
+#define L2TP_AVP_PRIVATE_GRP_ID 37 /* Private Group ID */
+#define L2TP_AVP_RX_CONN_SPEED 38 /* (Rx) Connect Speed */
+#define L2TP_AVP_SEQ_REQUIRED 39 /* Sequencing Required */
+#define L2TP_AVP_PPP_DISCON_CC 46 /* PPP Disconnect Cause Code - RFC 3145 */
+
+static const struct tok l2tp_avp2str[] = {
+ { L2TP_AVP_MSGTYPE, "MSGTYPE" },
+ { L2TP_AVP_RESULT_CODE, "RESULT_CODE" },
+ { L2TP_AVP_PROTO_VER, "PROTO_VER" },
+ { L2TP_AVP_FRAMING_CAP, "FRAMING_CAP" },
+ { L2TP_AVP_BEARER_CAP, "BEARER_CAP" },
+ { L2TP_AVP_TIE_BREAKER, "TIE_BREAKER" },
+ { L2TP_AVP_FIRM_VER, "FIRM_VER" },
+ { L2TP_AVP_HOST_NAME, "HOST_NAME" },
+ { L2TP_AVP_VENDOR_NAME, "VENDOR_NAME" },
+ { L2TP_AVP_ASSND_TUN_ID, "ASSND_TUN_ID" },
+ { L2TP_AVP_RECV_WIN_SIZE, "RECV_WIN_SIZE" },
+ { L2TP_AVP_CHALLENGE, "CHALLENGE" },
+ { L2TP_AVP_Q931_CC, "Q931_CC", },
+ { L2TP_AVP_CHALLENGE_RESP, "CHALLENGE_RESP" },
+ { L2TP_AVP_ASSND_SESS_ID, "ASSND_SESS_ID" },
+ { L2TP_AVP_CALL_SER_NUM, "CALL_SER_NUM" },
+ { L2TP_AVP_MINIMUM_BPS, "MINIMUM_BPS" },
+ { L2TP_AVP_MAXIMUM_BPS, "MAXIMUM_BPS" },
+ { L2TP_AVP_BEARER_TYPE, "BEARER_TYPE" },
+ { L2TP_AVP_FRAMING_TYPE, "FRAMING_TYPE" },
+ { L2TP_AVP_PACKET_PROC_DELAY, "PACKET_PROC_DELAY" },
+ { L2TP_AVP_CALLED_NUMBER, "CALLED_NUMBER" },
+ { L2TP_AVP_CALLING_NUMBER, "CALLING_NUMBER" },
+ { L2TP_AVP_SUB_ADDRESS, "SUB_ADDRESS" },
+ { L2TP_AVP_TX_CONN_SPEED, "TX_CONN_SPEED" },
+ { L2TP_AVP_PHY_CHANNEL_ID, "PHY_CHANNEL_ID" },
+ { L2TP_AVP_INI_RECV_LCP, "INI_RECV_LCP" },
+ { L2TP_AVP_LAST_SENT_LCP, "LAST_SENT_LCP" },
+ { L2TP_AVP_LAST_RECV_LCP, "LAST_RECV_LCP" },
+ { L2TP_AVP_PROXY_AUTH_TYPE, "PROXY_AUTH_TYPE" },
+ { L2TP_AVP_PROXY_AUTH_NAME, "PROXY_AUTH_NAME" },
+ { L2TP_AVP_PROXY_AUTH_CHAL, "PROXY_AUTH_CHAL" },
+ { L2TP_AVP_PROXY_AUTH_ID, "PROXY_AUTH_ID" },
+ { L2TP_AVP_PROXY_AUTH_RESP, "PROXY_AUTH_RESP" },
+ { L2TP_AVP_CALL_ERRORS, "CALL_ERRORS" },
+ { L2TP_AVP_ACCM, "ACCM" },
+ { L2TP_AVP_RANDOM_VECTOR, "RANDOM_VECTOR" },
+ { L2TP_AVP_PRIVATE_GRP_ID, "PRIVATE_GRP_ID" },
+ { L2TP_AVP_RX_CONN_SPEED, "RX_CONN_SPEED" },
+ { L2TP_AVP_SEQ_REQUIRED, "SEQ_REQUIRED" },
+ { L2TP_AVP_PPP_DISCON_CC, "PPP_DISCON_CC" },
+ { 0, NULL }
+};
+
+static const struct tok l2tp_authentype2str[] = {
+ { L2TP_AUTHEN_TYPE_RESERVED, "Reserved" },
+ { L2TP_AUTHEN_TYPE_TEXTUAL, "Textual" },
+ { L2TP_AUTHEN_TYPE_CHAP, "CHAP" },
+ { L2TP_AUTHEN_TYPE_PAP, "PAP" },
+ { L2TP_AUTHEN_TYPE_NO_AUTH, "No Auth" },
+ { L2TP_AUTHEN_TYPE_MSCHAPv1, "MS-CHAPv1" },
+ { 0, NULL }
+};
+
+#define L2TP_PPP_DISCON_CC_DIRECTION_GLOBAL 0
+#define L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER 1
+#define L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL 2
+
+static const struct tok l2tp_cc_direction2str[] = {
+ { L2TP_PPP_DISCON_CC_DIRECTION_GLOBAL, "global error" },
+ { L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER, "at peer" },
+ { L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL,"at local" },
+ { 0, NULL }
+};
+
+#if 0
+static char *l2tp_result_code_StopCCN[] = {
+ "Reserved",
+ "General request to clear control connection",
+ "General error--Error Code indicates the problem",
+ "Control channel already exists",
+ "Requester is not authorized to establish a control channel",
+ "The protocol version of the requester is not supported",
+ "Requester is being shut down",
+ "Finite State Machine error"
+#define L2TP_MAX_RESULT_CODE_STOPCC_INDEX 8
+};
+#endif
+
+#if 0
+static char *l2tp_result_code_CDN[] = {
+ "Reserved",
+ "Call disconnected due to loss of carrier",
+ "Call disconnected for the reason indicated in error code",
+ "Call disconnected for administrative reasons",
+ "Call failed due to lack of appropriate facilities being "
+ "available (temporary condition)",
+ "Call failed due to lack of appropriate facilities being "
+ "available (permanent condition)",
+ "Invalid destination",
+ "Call failed due to no carrier detected",
+ "Call failed due to detection of a busy signal",
+ "Call failed due to lack of a dial tone",
+ "Call was not established within time allotted by LAC",
+ "Call was connected but no appropriate framing was detected"
+#define L2TP_MAX_RESULT_CODE_CDN_INDEX 12
+};
+#endif
+
+#if 0
+static char *l2tp_error_code_general[] = {
+ "No general error",
+ "No control connection exists yet for this LAC-LNS pair",
+ "Length is wrong",
+ "One of the field values was out of range or "
+ "reserved field was non-zero"
+ "Insufficient resources to handle this operation now",
+ "The Session ID is invalid in this context",
+ "A generic vendor-specific error occurred in the LAC",
+ "Try another"
+#define L2TP_MAX_ERROR_CODE_GENERAL_INDEX 8
+};
+#endif
+
+/******************************/
+/* generic print out routines */
+/******************************/
+static void
+print_string(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ u_int i;
+ for (i=0; i<length; i++) {
+ fn_print_char(ndo, GET_U_1(dat));
+ dat++;
+ }
+}
+
+static void
+print_octets(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ u_int i;
+ for (i=0; i<length; i++) {
+ ND_PRINT("%02x", GET_U_1(dat));
+ dat++;
+ }
+}
+
+static void
+print_16bits_val(netdissect_options *ndo, const uint8_t *dat)
+{
+ ND_PRINT("%u", GET_BE_U_2(dat));
+}
+
+static void
+print_32bits_val(netdissect_options *ndo, const uint8_t *dat)
+{
+ ND_PRINT("%u", GET_BE_U_4(dat));
+}
+
+/***********************************/
+/* AVP-specific print out routines */
+/***********************************/
+static void
+l2tp_msgtype_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ if (length < 2) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ ND_PRINT("%s", tok2str(l2tp_msgtype2str, "MSGTYPE-#%u",
+ GET_BE_U_2(dat)));
+}
+
+static void
+l2tp_result_code_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ /* Result Code */
+ if (length < 2) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ ND_PRINT("%u", GET_BE_U_2(dat));
+ dat += 2;
+ length -= 2;
+
+ /* Error Code (opt) */
+ if (length == 0)
+ return;
+ if (length < 2) {
+ ND_PRINT(" AVP too short");
+ return;
+ }
+ ND_PRINT("/%u", GET_BE_U_2(dat));
+ dat += 2;
+ length -= 2;
+
+ /* Error Message (opt) */
+ if (length == 0)
+ return;
+ ND_PRINT(" ");
+ print_string(ndo, dat, length);
+}
+
+static void
+l2tp_proto_ver_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ if (length < 2) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ ND_PRINT("%u.%u", (GET_BE_U_2(dat) >> 8),
+ (GET_BE_U_2(dat) & 0xff));
+}
+
+static void
+l2tp_framing_cap_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ if (GET_BE_U_4(dat) & L2TP_FRAMING_CAP_ASYNC_MASK) {
+ ND_PRINT("A");
+ }
+ if (GET_BE_U_4(dat) & L2TP_FRAMING_CAP_SYNC_MASK) {
+ ND_PRINT("S");
+ }
+}
+
+static void
+l2tp_bearer_cap_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ if (GET_BE_U_4(dat) & L2TP_BEARER_CAP_ANALOG_MASK) {
+ ND_PRINT("A");
+ }
+ if (GET_BE_U_4(dat) & L2TP_BEARER_CAP_DIGITAL_MASK) {
+ ND_PRINT("D");
+ }
+}
+
+static void
+l2tp_q931_cc_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ if (length < 3) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ print_16bits_val(ndo, dat);
+ ND_PRINT(", %02x", GET_U_1(dat + 2));
+ dat += 3;
+ length -= 3;
+ if (length != 0) {
+ ND_PRINT(" ");
+ print_string(ndo, dat, length);
+ }
+}
+
+static void
+l2tp_bearer_type_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ if (GET_BE_U_4(dat) & L2TP_BEARER_TYPE_ANALOG_MASK) {
+ ND_PRINT("A");
+ }
+ if (GET_BE_U_4(dat) & L2TP_BEARER_TYPE_DIGITAL_MASK) {
+ ND_PRINT("D");
+ }
+}
+
+static void
+l2tp_framing_type_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ if (GET_BE_U_4(dat) & L2TP_FRAMING_TYPE_ASYNC_MASK) {
+ ND_PRINT("A");
+ }
+ if (GET_BE_U_4(dat) & L2TP_FRAMING_TYPE_SYNC_MASK) {
+ ND_PRINT("S");
+ }
+}
+
+static void
+l2tp_packet_proc_delay_print(netdissect_options *ndo)
+{
+ ND_PRINT("obsolete");
+}
+
+static void
+l2tp_proxy_auth_type_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ if (length < 2) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ ND_PRINT("%s", tok2str(l2tp_authentype2str,
+ "AuthType-#%u", GET_BE_U_2(dat)));
+}
+
+static void
+l2tp_proxy_auth_id_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ if (length < 2) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ ND_PRINT("%u", GET_BE_U_2(dat) & L2TP_PROXY_AUTH_ID_MASK);
+}
+
+static void
+l2tp_call_errors_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ uint32_t val;
+
+ if (length < 2) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ dat += 2; /* skip "Reserved" */
+ length -= 2;
+
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ val = GET_BE_U_4(dat); dat += 4; length -= 4;
+ ND_PRINT("CRCErr=%u ", val);
+
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ val = GET_BE_U_4(dat); dat += 4; length -= 4;
+ ND_PRINT("FrameErr=%u ", val);
+
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ val = GET_BE_U_4(dat); dat += 4; length -= 4;
+ ND_PRINT("HardOver=%u ", val);
+
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ val = GET_BE_U_4(dat); dat += 4; length -= 4;
+ ND_PRINT("BufOver=%u ", val);
+
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ val = GET_BE_U_4(dat); dat += 4; length -= 4;
+ ND_PRINT("Timeout=%u ", val);
+
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ val = GET_BE_U_4(dat); dat += 4; length -= 4;
+ ND_PRINT("AlignErr=%u ", val);
+}
+
+static void
+l2tp_accm_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ uint32_t val;
+
+ if (length < 2) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ dat += 2; /* skip "Reserved" */
+ length -= 2;
+
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ val = GET_BE_U_4(dat); dat += 4; length -= 4;
+ ND_PRINT("send=%08x ", val);
+
+ if (length < 4) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ val = GET_BE_U_4(dat); dat += 4; length -= 4;
+ ND_PRINT("recv=%08x ", val);
+}
+
+static void
+l2tp_ppp_discon_cc_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ if (length < 5) {
+ ND_PRINT("AVP too short");
+ return;
+ }
+ /* Disconnect Code */
+ ND_PRINT("%04x, ", GET_BE_U_2(dat));
+ dat += 2;
+ length -= 2;
+ /* Control Protocol Number */
+ ND_PRINT("%04x ", GET_BE_U_2(dat));
+ dat += 2;
+ length -= 2;
+ /* Direction */
+ ND_PRINT("%s", tok2str(l2tp_cc_direction2str,
+ "Direction-#%u", GET_U_1(dat)));
+ dat++;
+ length--;
+
+ if (length != 0) {
+ ND_PRINT(" ");
+ print_string(ndo, (const u_char *)dat, length);
+ }
+}
+
+static u_int
+l2tp_avp_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ u_int len;
+ uint16_t attr_type;
+ int hidden = FALSE;
+
+ ND_PRINT(" ");
+ /* Flags & Length */
+ len = GET_BE_U_2(dat) & L2TP_AVP_HDR_LEN_MASK;
+
+ /* If it is not long enough to contain the header, we'll give up. */
+ if (len < 6)
+ goto trunc;
+
+ /* If it goes past the end of the remaining length of the packet,
+ we'll give up. */
+ if (len > (u_int)length)
+ goto trunc;
+
+ /* If it goes past the end of the remaining length of the captured
+ data, we'll give up. */
+ ND_TCHECK_LEN(dat, len);
+
+ /*
+ * After this point, we don't need to check whether we go past
+ * the length of the captured data; however, we *do* need to
+ * check whether we go past the end of the AVP.
+ */
+
+ if (GET_BE_U_2(dat) & L2TP_AVP_HDR_FLAG_MANDATORY) {
+ ND_PRINT("*");
+ }
+ if (GET_BE_U_2(dat) & L2TP_AVP_HDR_FLAG_HIDDEN) {
+ hidden = TRUE;
+ ND_PRINT("?");
+ }
+ dat += 2;
+
+ if (GET_BE_U_2(dat)) {
+ /* Vendor Specific Attribute */
+ ND_PRINT("VENDOR%04x:", GET_BE_U_2(dat)); dat += 2;
+ ND_PRINT("ATTR%04x", GET_BE_U_2(dat)); dat += 2;
+ ND_PRINT("(");
+ print_octets(ndo, dat, len-6);
+ ND_PRINT(")");
+ } else {
+ /* IETF-defined Attributes */
+ dat += 2;
+ attr_type = GET_BE_U_2(dat); dat += 2;
+ ND_PRINT("%s", tok2str(l2tp_avp2str, "AVP-#%u", attr_type));
+ ND_PRINT("(");
+ if (hidden) {
+ ND_PRINT("???");
+ } else {
+ switch (attr_type) {
+ case L2TP_AVP_MSGTYPE:
+ l2tp_msgtype_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_RESULT_CODE:
+ l2tp_result_code_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_PROTO_VER:
+ l2tp_proto_ver_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_FRAMING_CAP:
+ l2tp_framing_cap_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_BEARER_CAP:
+ l2tp_bearer_cap_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_TIE_BREAKER:
+ if (len-6 < 8) {
+ ND_PRINT("AVP too short");
+ break;
+ }
+ print_octets(ndo, dat, 8);
+ break;
+ case L2TP_AVP_FIRM_VER:
+ case L2TP_AVP_ASSND_TUN_ID:
+ case L2TP_AVP_RECV_WIN_SIZE:
+ case L2TP_AVP_ASSND_SESS_ID:
+ if (len-6 < 2) {
+ ND_PRINT("AVP too short");
+ break;
+ }
+ print_16bits_val(ndo, dat);
+ break;
+ case L2TP_AVP_HOST_NAME:
+ case L2TP_AVP_VENDOR_NAME:
+ case L2TP_AVP_CALLING_NUMBER:
+ case L2TP_AVP_CALLED_NUMBER:
+ case L2TP_AVP_SUB_ADDRESS:
+ case L2TP_AVP_PROXY_AUTH_NAME:
+ case L2TP_AVP_PRIVATE_GRP_ID:
+ print_string(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_CHALLENGE:
+ case L2TP_AVP_INI_RECV_LCP:
+ case L2TP_AVP_LAST_SENT_LCP:
+ case L2TP_AVP_LAST_RECV_LCP:
+ case L2TP_AVP_PROXY_AUTH_CHAL:
+ case L2TP_AVP_PROXY_AUTH_RESP:
+ case L2TP_AVP_RANDOM_VECTOR:
+ print_octets(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_Q931_CC:
+ l2tp_q931_cc_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_CHALLENGE_RESP:
+ if (len-6 < 16) {
+ ND_PRINT("AVP too short");
+ break;
+ }
+ print_octets(ndo, dat, 16);
+ break;
+ case L2TP_AVP_CALL_SER_NUM:
+ case L2TP_AVP_MINIMUM_BPS:
+ case L2TP_AVP_MAXIMUM_BPS:
+ case L2TP_AVP_TX_CONN_SPEED:
+ case L2TP_AVP_PHY_CHANNEL_ID:
+ case L2TP_AVP_RX_CONN_SPEED:
+ if (len-6 < 4) {
+ ND_PRINT("AVP too short");
+ break;
+ }
+ print_32bits_val(ndo, dat);
+ break;
+ case L2TP_AVP_BEARER_TYPE:
+ l2tp_bearer_type_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_FRAMING_TYPE:
+ l2tp_framing_type_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_PACKET_PROC_DELAY:
+ l2tp_packet_proc_delay_print(ndo);
+ break;
+ case L2TP_AVP_PROXY_AUTH_TYPE:
+ l2tp_proxy_auth_type_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_PROXY_AUTH_ID:
+ l2tp_proxy_auth_id_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_CALL_ERRORS:
+ l2tp_call_errors_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_ACCM:
+ l2tp_accm_print(ndo, dat, len-6);
+ break;
+ case L2TP_AVP_SEQ_REQUIRED:
+ break; /* No Attribute Value */
+ case L2TP_AVP_PPP_DISCON_CC:
+ l2tp_ppp_discon_cc_print(ndo, dat, len-6);
+ break;
+ default:
+ break;
+ }
+ }
+ ND_PRINT(")");
+ }
+
+ return (len);
+
+ trunc:
+ nd_print_trunc(ndo);
+ return (0);
+}
+
+
+void
+l2tp_print(netdissect_options *ndo, const u_char *dat, u_int length)
+{
+ const u_char *ptr = dat;
+ u_int cnt = 0; /* total octets consumed */
+ uint16_t pad;
+ int flag_t, flag_l, flag_s, flag_o;
+ uint16_t l2tp_len;
+
+ ndo->ndo_protocol = "l2tp";
+ flag_t = flag_l = flag_s = flag_o = FALSE;
+
+ if ((GET_BE_U_2(ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2TP) {
+ ND_PRINT(" l2tp:");
+ } else if ((GET_BE_U_2(ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2F) {
+ ND_PRINT(" l2f:");
+ return; /* nothing to do */
+ } else {
+ ND_PRINT(" Unknown Version, neither L2F(1) nor L2TP(2)");
+ return; /* nothing we can do */
+ }
+
+ ND_PRINT("[");
+ if (GET_BE_U_2(ptr) & L2TP_FLAG_TYPE) {
+ flag_t = TRUE;
+ ND_PRINT("T");
+ }
+ if (GET_BE_U_2(ptr) & L2TP_FLAG_LENGTH) {
+ flag_l = TRUE;
+ ND_PRINT("L");
+ }
+ if (GET_BE_U_2(ptr) & L2TP_FLAG_SEQUENCE) {
+ flag_s = TRUE;
+ ND_PRINT("S");
+ }
+ if (GET_BE_U_2(ptr) & L2TP_FLAG_OFFSET) {
+ flag_o = TRUE;
+ ND_PRINT("O");
+ }
+ if (GET_BE_U_2(ptr) & L2TP_FLAG_PRIORITY)
+ ND_PRINT("P");
+ ND_PRINT("]");
+
+ ptr += 2;
+ cnt += 2;
+
+ if (flag_l) {
+ l2tp_len = GET_BE_U_2(ptr);
+ ptr += 2;
+ cnt += 2;
+ } else {
+ l2tp_len = 0;
+ }
+ /* Tunnel ID */
+ ND_PRINT("(%u/", GET_BE_U_2(ptr));
+ ptr += 2;
+ cnt += 2;
+ /* Session ID */
+ ND_PRINT("%u)", GET_BE_U_2(ptr));
+ ptr += 2;
+ cnt += 2;
+
+ if (flag_s) {
+ ND_PRINT("Ns=%u,", GET_BE_U_2(ptr));
+ ptr += 2;
+ cnt += 2;
+ ND_PRINT("Nr=%u", GET_BE_U_2(ptr));
+ ptr += 2;
+ cnt += 2;
+ }
+
+ if (flag_o) { /* Offset Size */
+ pad = GET_BE_U_2(ptr);
+ /* Offset padding octets in packet buffer? */
+ ND_TCHECK_LEN(ptr + 2, pad);
+ ptr += (2 + pad);
+ cnt += (2 + pad);
+ }
+
+ if (flag_l) {
+ if (length < l2tp_len) {
+ ND_PRINT(" Length %u larger than packet", l2tp_len);
+ return;
+ }
+ length = l2tp_len;
+ }
+ if (length < cnt) {
+ ND_PRINT(" Length %u smaller than header length", length);
+ return;
+ }
+ if (flag_t) {
+ if (!flag_l) {
+ ND_PRINT(" No length");
+ return;
+ }
+ if (length - cnt == 0) {
+ ND_PRINT(" ZLB");
+ } else {
+ /*
+ * Print AVPs.
+ */
+ while (length - cnt != 0) {
+ u_int avp_length;
+
+ avp_length = l2tp_avp_print(ndo, ptr, length - cnt);
+ if (avp_length == 0) {
+ /*
+ * Truncated.
+ */
+ break;
+ }
+ cnt += avp_length;
+ ptr += avp_length;
+ }
+ }
+ } else {
+ ND_PRINT(" {");
+ ppp_print(ndo, ptr, length - cnt);
+ ND_PRINT("}");
+ }
+ return;
+trunc:
+ nd_print_trunc(ndo);
+}