print-dhcp6.c - platform/external/tcpdump - Git at Google

 /*
  * Copyright (C) 1998 and 1999 WIDE Project.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the name of the project 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 BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */

 /* \summary: IPv6 DHCP printer */

 /*
  * RFC3315: DHCPv6
  * supported DHCPv6 options:
  *  RFC3319: Session Initiation Protocol (SIP) Servers options,
  *  RFC3633: IPv6 Prefix options,
  *  RFC3646: DNS Configuration options,
  *  RFC3898: Network Information Service (NIS) Configuration options,
  *  RFC4075: Simple Network Time Protocol (SNTP) Configuration option,
  *  RFC4242: Information Refresh Time option,
  *  RFC4280: Broadcast and Multicast Control Servers options,
  *  RFC5908: Network Time Protocol (NTP) Server Option for DHCPv6
  *  RFC6334: Dual-Stack Lite option,
  */

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #include <netdissect-stdinc.h>

 #include <stdio.h>
 #include <string.h>

 #include "netdissect.h"
 #include "addrtoname.h"
 #include "extract.h"

 /* lease duration */
 #define DHCP6_DURATION_INFINITE 0xffffffff

 /* Error Values */
 #define DH6ERR_FAILURE		16
 #define DH6ERR_AUTHFAIL		17
 #define DH6ERR_POORLYFORMED	18
 #define DH6ERR_UNAVAIL		19
 #define DH6ERR_OPTUNAVAIL	20

 /* Message type */
 #define DH6_SOLICIT	1
 #define DH6_ADVERTISE	2
 #define DH6_REQUEST	3
 #define DH6_CONFIRM	4
 #define DH6_RENEW	5
 #define DH6_REBIND	6
 #define DH6_REPLY	7
 #define DH6_RELEASE	8
 #define DH6_DECLINE	9
 #define DH6_RECONFIGURE	10
 #define DH6_INFORM_REQ	11
 #define DH6_RELAY_FORW	12
 #define DH6_RELAY_REPLY	13
 #define DH6_LEASEQUERY	14
 #define DH6_LQ_REPLY	15

 static const struct tok dh6_msgtype_str[] = {
 	{ DH6_SOLICIT,     "solicit"          },
 	{ DH6_ADVERTISE,   "advertise"        },
 	{ DH6_REQUEST,     "request"          },
 	{ DH6_CONFIRM,     "confirm"          },
 	{ DH6_RENEW,       "renew"            },
 	{ DH6_REBIND,      "rebind"           },
 	{ DH6_REPLY,       "reply"            },
 	{ DH6_RELEASE,     "release"          },
 	{ DH6_DECLINE,     "decline"          },
 	{ DH6_RECONFIGURE, "reconfigure"      },
 	{ DH6_INFORM_REQ,  "inf-req"          },
 	{ DH6_RELAY_FORW,  "relay-fwd"        },
 	{ DH6_RELAY_REPLY, "relay-reply"      },
 	{ DH6_LEASEQUERY,  "leasequery"       },
 	{ DH6_LQ_REPLY,    "leasequery-reply" },
 	{ 0, NULL }
 };

 /* DHCP6 base packet format */
 struct dhcp6 {
 	union {
 		nd_uint8_t m;
 		nd_uint32_t x;
 	} dh6_msgtypexid;
 	/* options follow */
 };
 #define dh6_msgtype	dh6_msgtypexid.m
 #define dh6_xid		dh6_msgtypexid.x
 #define DH6_XIDMASK	0x00ffffff

 /* DHCPv6 relay messages */
 struct dhcp6_relay {
 	nd_uint8_t dh6relay_msgtype;
 	nd_uint8_t dh6relay_hcnt;
 	nd_uint8_t dh6relay_linkaddr[16];	/* XXX: badly aligned */
 	nd_uint8_t dh6relay_peeraddr[16];
 	/* options follow */
 };

 /* options */
 #define DH6OPT_CLIENTID	1
 #define DH6OPT_SERVERID	2
 #define DH6OPT_IA_NA 3
 #define DH6OPT_IA_TA 4
 #define DH6OPT_IA_ADDR 5
 #define DH6OPT_ORO 6
 #define DH6OPT_PREFERENCE 7
 #  define DH6OPT_PREF_MAX 255
 #define DH6OPT_ELAPSED_TIME 8
 #define DH6OPT_RELAY_MSG 9
 /*#define DH6OPT_SERVER_MSG 10 deprecated */
 #define DH6OPT_AUTH 11
 #  define DH6OPT_AUTHPROTO_DELAYED 2
 #  define DH6OPT_AUTHPROTO_RECONFIG 3
 #  define DH6OPT_AUTHALG_HMACMD5 1
 #  define DH6OPT_AUTHRDM_MONOCOUNTER 0
 #  define DH6OPT_AUTHRECONFIG_KEY 1
 #  define DH6OPT_AUTHRECONFIG_HMACMD5 2
 #define DH6OPT_UNICAST 12
 #define DH6OPT_STATUS_CODE 13
 #  define DH6OPT_STCODE_SUCCESS 0
 #  define DH6OPT_STCODE_UNSPECFAIL 1
 #  define DH6OPT_STCODE_NOADDRAVAIL 2
 #  define DH6OPT_STCODE_NOBINDING 3
 #  define DH6OPT_STCODE_NOTONLINK 4
 #  define DH6OPT_STCODE_USEMULTICAST 5
 #  define DH6OPT_STCODE_NOPREFIXAVAIL 6
 #  define DH6OPT_STCODE_UNKNOWNQUERYTYPE 7
 #  define DH6OPT_STCODE_MALFORMEDQUERY 8
 #  define DH6OPT_STCODE_NOTCONFIGURED 9
 #  define DH6OPT_STCODE_NOTALLOWED 10
 #define DH6OPT_RAPID_COMMIT 14
 #define DH6OPT_USER_CLASS 15
 #define DH6OPT_VENDOR_CLASS 16
 #define DH6OPT_VENDOR_OPTS 17
 #define DH6OPT_INTERFACE_ID 18
 #define DH6OPT_RECONF_MSG 19
 #define DH6OPT_RECONF_ACCEPT 20
 #define DH6OPT_SIP_SERVER_D 21
 #define DH6OPT_SIP_SERVER_A 22
 #define DH6OPT_DNS_SERVERS 23
 #define DH6OPT_DOMAIN_LIST 24
 #define DH6OPT_IA_PD 25
 #define DH6OPT_IA_PD_PREFIX 26
 #define DH6OPT_NIS_SERVERS 27
 #define DH6OPT_NISP_SERVERS 28
 #define DH6OPT_NIS_NAME 29
 #define DH6OPT_NISP_NAME 30
 #define DH6OPT_SNTP_SERVERS 31
 #define DH6OPT_LIFETIME 32
 #define DH6OPT_BCMCS_SERVER_D 33
 #define DH6OPT_BCMCS_SERVER_A 34
 #define DH6OPT_GEOCONF_CIVIC 36
 #define DH6OPT_REMOTE_ID 37
 #define DH6OPT_SUBSCRIBER_ID 38
 #define DH6OPT_CLIENT_FQDN 39
 #define DH6OPT_PANA_AGENT 40
 #define DH6OPT_NEW_POSIX_TIMEZONE 41
 #define DH6OPT_NEW_TZDB_TIMEZONE 42
 #define DH6OPT_ERO 43
 #define DH6OPT_LQ_QUERY 44
 #define DH6OPT_CLIENT_DATA 45
 #define DH6OPT_CLT_TIME 46
 #define DH6OPT_LQ_RELAY_DATA 47
 #define DH6OPT_LQ_CLIENT_LINK 48
 #define DH6OPT_NTP_SERVER 56
 #  define DH6OPT_NTP_SUBOPTION_SRV_ADDR 1
 #  define DH6OPT_NTP_SUBOPTION_MC_ADDR 2
 #  define DH6OPT_NTP_SUBOPTION_SRV_FQDN 3
 #define DH6OPT_AFTR_NAME 64
 #define DH6OPT_MUDURL 112

 static const struct tok dh6opt_str[] = {
 	{ DH6OPT_CLIENTID,           "client-ID"            },
 	{ DH6OPT_SERVERID,           "server-ID"            },
 	{ DH6OPT_IA_NA,              "IA_NA"                },
 	{ DH6OPT_IA_TA,              "IA_TA"                },
 	{ DH6OPT_IA_ADDR,            "IA_ADDR"              },
 	{ DH6OPT_ORO,                "option-request"       },
 	{ DH6OPT_PREFERENCE,         "preference"           },
 	{ DH6OPT_ELAPSED_TIME,       "elapsed-time"         },
 	{ DH6OPT_RELAY_MSG,          "relay-message"        },
 	{ DH6OPT_AUTH,               "authentication"       },
 	{ DH6OPT_UNICAST,            "server-unicast"       },
 	{ DH6OPT_STATUS_CODE,        "status-code"          },
 	{ DH6OPT_RAPID_COMMIT,       "rapid-commit"         },
 	{ DH6OPT_USER_CLASS,         "user-class"           },
 	{ DH6OPT_VENDOR_CLASS,       "vendor-class"         },
 	{ DH6OPT_VENDOR_OPTS,        "vendor-specific-info" },
 	{ DH6OPT_INTERFACE_ID,       "interface-ID"         },
 	{ DH6OPT_RECONF_MSG,         "reconfigure-message"  },
 	{ DH6OPT_RECONF_ACCEPT,      "reconfigure-accept"   },
 	{ DH6OPT_SIP_SERVER_D,       "SIP-servers-domain"   },
 	{ DH6OPT_SIP_SERVER_A,       "SIP-servers-address"  },
 	{ DH6OPT_DNS_SERVERS,        "DNS-server"           },
 	{ DH6OPT_DOMAIN_LIST,        "DNS-search-list"      },
 	{ DH6OPT_IA_PD,              "IA_PD"                },
 	{ DH6OPT_IA_PD_PREFIX,       "IA_PD-prefix"         },
 	{ DH6OPT_SNTP_SERVERS,       "SNTP-servers"         },
 	{ DH6OPT_LIFETIME,           "lifetime"             },
 	{ DH6OPT_NIS_SERVERS,        "NIS-server"           },
 	{ DH6OPT_NISP_SERVERS,       "NIS+-server"          },
 	{ DH6OPT_NIS_NAME,           "NIS-domain-name"      },
 	{ DH6OPT_NISP_NAME,          "NIS+-domain-name"     },
 	{ DH6OPT_BCMCS_SERVER_D,     "BCMCS-domain-name"    },
 	{ DH6OPT_BCMCS_SERVER_A,     "BCMCS-server"         },
 	{ DH6OPT_GEOCONF_CIVIC,      "Geoconf-Civic"        },
 	{ DH6OPT_REMOTE_ID,          "Remote-ID"            },
 	{ DH6OPT_SUBSCRIBER_ID,      "Subscriber-ID"        },
 	{ DH6OPT_CLIENT_FQDN,        "Client-FQDN"          },
 	{ DH6OPT_PANA_AGENT,         "PANA-agent"           },
 	{ DH6OPT_NEW_POSIX_TIMEZONE, "POSIX-timezone"       },
 	{ DH6OPT_NEW_TZDB_TIMEZONE,  "POSIX-tz-database"    },
 	{ DH6OPT_ERO,                "Echo-request-option"  },
 	{ DH6OPT_LQ_QUERY,           "Lease-query"          },
 	{ DH6OPT_CLIENT_DATA,        "LQ-client-data"       },
 	{ DH6OPT_CLT_TIME,           "Clt-time"             },
 	{ DH6OPT_LQ_RELAY_DATA,      "LQ-relay-data"        },
 	{ DH6OPT_LQ_CLIENT_LINK,     "LQ-client-link"       },
 	{ DH6OPT_NTP_SERVER,         "NTP-server"           },
 	{ DH6OPT_AFTR_NAME,          "AFTR-Name"            },
 	{ DH6OPT_MUDURL,             "MUD-URL"              },
 	{ 0, NULL }
 };

 static const struct tok dh6opt_stcode_str[] = {
 	{ DH6OPT_STCODE_SUCCESS,          "Success"          }, /* RFC3315 */
 	{ DH6OPT_STCODE_UNSPECFAIL,       "UnspecFail"       }, /* RFC3315 */
 	{ DH6OPT_STCODE_NOADDRAVAIL,      "NoAddrsAvail"     }, /* RFC3315 */
 	{ DH6OPT_STCODE_NOBINDING,        "NoBinding"        }, /* RFC3315 */
 	{ DH6OPT_STCODE_NOTONLINK,        "NotOnLink"        }, /* RFC3315 */
 	{ DH6OPT_STCODE_USEMULTICAST,     "UseMulticast"     }, /* RFC3315 */
 	{ DH6OPT_STCODE_NOPREFIXAVAIL,    "NoPrefixAvail"    }, /* RFC3633 */
 	{ DH6OPT_STCODE_UNKNOWNQUERYTYPE, "UnknownQueryType" }, /* RFC5007 */
 	{ DH6OPT_STCODE_MALFORMEDQUERY,   "MalformedQuery"   }, /* RFC5007 */
 	{ DH6OPT_STCODE_NOTCONFIGURED,    "NotConfigured"    }, /* RFC5007 */
 	{ DH6OPT_STCODE_NOTALLOWED,       "NotAllowed"       }, /* RFC5007 */
 	{ 0, NULL }
 };

 struct dhcp6opt {
 	nd_uint16_t dh6opt_type;
 	nd_uint16_t dh6opt_len;
 	/* type-dependent data follows */
 };

 static const char *
 dhcp6stcode(const uint16_t code)
 {
 	return code > 255 ? "INVALID code" : tok2str(dh6opt_stcode_str, "code%u", code);
 }

 static void
 dhcp6opt_print(netdissect_options *ndo,
                const u_char *cp, const u_char *ep)
 {
 	const struct dhcp6opt *dh6o;
 	const u_char *tp;
 	size_t i;
 	uint16_t opttype;
 	size_t optlen;
 	uint8_t auth_proto;
 	u_int authinfolen, authrealmlen;
 	int remain_len;  /* Length of remaining options */
 	int label_len;   /* Label length */
 	uint16_t subopt_code;
 	uint16_t subopt_len;

 	if (cp == ep)
 		return;
 	while (cp < ep) {
 		if (ep < cp + sizeof(*dh6o))
 			goto trunc;
 		dh6o = (const struct dhcp6opt *)cp;
 		ND_TCHECK(*dh6o);
 		optlen = EXTRACT_16BITS(&dh6o->dh6opt_len);
 		if (ep < cp + sizeof(*dh6o) + optlen)
 			goto trunc;
 		opttype = EXTRACT_16BITS(&dh6o->dh6opt_type);
 		ND_PRINT((ndo, " (%s", tok2str(dh6opt_str, "opt_%u", opttype)));
 		ND_TCHECK2(*(cp + sizeof(*dh6o)), optlen);
 		switch (opttype) {
 		case DH6OPT_CLIENTID:
 		case DH6OPT_SERVERID:
 			if (optlen < 2) {
 				/*(*/
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			switch (EXTRACT_16BITS(tp)) {
 			case 1:
 				if (optlen >= 2 + 6) {
 					ND_PRINT((ndo, " hwaddr/time type %u time %u ",
 					    EXTRACT_16BITS(&tp[2]),
 					    EXTRACT_32BITS(&tp[4])));
 					for (i = 8; i < optlen; i++)
 						ND_PRINT((ndo, "%02x", tp[i]));
 					/*(*/
 					ND_PRINT((ndo, ")"));
 				} else {
 					/*(*/
 					ND_PRINT((ndo, " ?)"));
 				}
 				break;
 			case 2:
 				if (optlen >= 2 + 8) {
 					ND_PRINT((ndo, " vid "));
 					for (i = 2; i < 2 + 8; i++)
 						ND_PRINT((ndo, "%02x", tp[i]));
 					/*(*/
 					ND_PRINT((ndo, ")"));
 				} else {
 					/*(*/
 					ND_PRINT((ndo, " ?)"));
 				}
 				break;
 			case 3:
 				if (optlen >= 2 + 2) {
 					ND_PRINT((ndo, " hwaddr type %u ",
 					    EXTRACT_16BITS(&tp[2])));
 					for (i = 4; i < optlen; i++)
 						ND_PRINT((ndo, "%02x", tp[i]));
 					/*(*/
 					ND_PRINT((ndo, ")"));
 				} else {
 					/*(*/
 					ND_PRINT((ndo, " ?)"));
 				}
 				break;
 			default:
 				ND_PRINT((ndo, " type %d)", EXTRACT_16BITS(tp)));
 				break;
 			}
 			break;
 		case DH6OPT_IA_ADDR:
 			if (optlen < 24) {
 				/*(*/
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, " %s", ip6addr_string(ndo, &tp[0])));
 			ND_PRINT((ndo, " pltime:%u vltime:%u",
 			    EXTRACT_32BITS(&tp[16]),
 			    EXTRACT_32BITS(&tp[20])));
 			if (optlen > 24) {
 				/* there are sub-options */
 				dhcp6opt_print(ndo, tp + 24, tp + optlen);
 			}
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_ORO:
 		case DH6OPT_ERO:
 			if (optlen % 2) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			for (i = 0; i < optlen; i += 2) {
 				ND_PRINT((ndo, " %s",
 				    tok2str(dh6opt_str, "opt_%u", EXTRACT_16BITS(&tp[i]))));
 			}
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_PREFERENCE:
 			if (optlen != 1) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, " %d)", *tp));
 			break;
 		case DH6OPT_ELAPSED_TIME:
 			if (optlen != 2) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, " %d)", EXTRACT_16BITS(tp)));
 			break;
 		case DH6OPT_RELAY_MSG:
 			ND_PRINT((ndo, " ("));
 			tp = (const u_char *)(dh6o + 1);
 			dhcp6_print(ndo, tp, optlen);
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_AUTH:
 			if (optlen < 11) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			auth_proto = *tp;
 			switch (auth_proto) {
 			case DH6OPT_AUTHPROTO_DELAYED:
 				ND_PRINT((ndo, " proto: delayed"));
 				break;
 			case DH6OPT_AUTHPROTO_RECONFIG:
 				ND_PRINT((ndo, " proto: reconfigure"));
 				break;
 			default:
 				ND_PRINT((ndo, " proto: %d", auth_proto));
 				break;
 			}
 			tp++;
 			switch (*tp) {
 			case DH6OPT_AUTHALG_HMACMD5:
 				/* XXX: may depend on the protocol */
 				ND_PRINT((ndo, ", alg: HMAC-MD5"));
 				break;
 			default:
 				ND_PRINT((ndo, ", alg: %d", *tp));
 				break;
 			}
 			tp++;
 			switch (*tp) {
 			case DH6OPT_AUTHRDM_MONOCOUNTER:
 				ND_PRINT((ndo, ", RDM: mono"));
 				break;
 			default:
 				ND_PRINT((ndo, ", RDM: %d", *tp));
 				break;
 			}
 			tp++;
 			ND_PRINT((ndo, ", RD:"));
 			for (i = 0; i < 4; i++, tp += 2)
 				ND_PRINT((ndo, " %04x", EXTRACT_16BITS(tp)));

 			/* protocol dependent part */
 			authinfolen = optlen - 11;
 			switch (auth_proto) {
 			case DH6OPT_AUTHPROTO_DELAYED:
 				if (authinfolen == 0)
 					break;
 				if (authinfolen < 20) {
 					ND_PRINT((ndo, " ??"));
 					break;
 				}
 				authrealmlen = authinfolen - 20;
 				if (authrealmlen > 0) {
 					ND_PRINT((ndo, ", realm: "));
 				}
 				for (i = 0; i < authrealmlen; i++, tp++)
 					ND_PRINT((ndo, "%02x", *tp));
 				ND_PRINT((ndo, ", key ID: %08x", EXTRACT_32BITS(tp)));
 				tp += 4;
 				ND_PRINT((ndo, ", HMAC-MD5:"));
 				for (i = 0; i < 4; i++, tp+= 4)
 					ND_PRINT((ndo, " %08x", EXTRACT_32BITS(tp)));
 				break;
 			case DH6OPT_AUTHPROTO_RECONFIG:
 				if (authinfolen != 17) {
 					ND_PRINT((ndo, " ??"));
 					break;
 				}
 				switch (*tp++) {
 				case DH6OPT_AUTHRECONFIG_KEY:
 					ND_PRINT((ndo, " reconfig-key"));
 					break;
 				case DH6OPT_AUTHRECONFIG_HMACMD5:
 					ND_PRINT((ndo, " type: HMAC-MD5"));
 					break;
 				default:
 					ND_PRINT((ndo, " type: ??"));
 					break;
 				}
 				ND_PRINT((ndo, " value:"));
 				for (i = 0; i < 4; i++, tp+= 4)
 					ND_PRINT((ndo, " %08x", EXTRACT_32BITS(tp)));
 				break;
 			default:
 				ND_PRINT((ndo, " ??"));
 				break;
 			}

 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_RAPID_COMMIT: /* nothing todo */
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_INTERFACE_ID:
 		case DH6OPT_SUBSCRIBER_ID:
 			/*
 			 * Since we cannot predict the encoding, print hex dump
 			 * at most 10 characters.
 			 */
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, " "));
 			for (i = 0; i < optlen && i < 10; i++)
 				ND_PRINT((ndo, "%02x", tp[i]));
 			ND_PRINT((ndo, "...)"));
 			break;
 		case DH6OPT_RECONF_MSG:
 			if (optlen != 1) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			switch (*tp) {
 			case DH6_RENEW:
 				ND_PRINT((ndo, " for renew)"));
 				break;
 			case DH6_INFORM_REQ:
 				ND_PRINT((ndo, " for inf-req)"));
 				break;
 			default:
 				ND_PRINT((ndo, " for ?\?\?(%02x))", *tp));
 				break;
 			}
 			break;
 		case DH6OPT_RECONF_ACCEPT: /* nothing todo */
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_SIP_SERVER_A:
 		case DH6OPT_DNS_SERVERS:
 		case DH6OPT_SNTP_SERVERS:
 		case DH6OPT_NIS_SERVERS:
 		case DH6OPT_NISP_SERVERS:
 		case DH6OPT_BCMCS_SERVER_A:
 		case DH6OPT_PANA_AGENT:
 		case DH6OPT_LQ_CLIENT_LINK:
 			if (optlen % 16) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			for (i = 0; i < optlen; i += 16)
 				ND_PRINT((ndo, " %s", ip6addr_string(ndo, &tp[i])));
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_SIP_SERVER_D:
 		case DH6OPT_DOMAIN_LIST:
 			tp = (const u_char *)(dh6o + 1);
 			while (tp < cp + sizeof(*dh6o) + optlen) {
 				ND_PRINT((ndo, " "));
 				if ((tp = ns_nprint(ndo, tp, cp + sizeof(*dh6o) + optlen)) == NULL)
 					goto trunc;
 			}
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_STATUS_CODE:
 			if (optlen < 2) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, " %s)", dhcp6stcode(EXTRACT_16BITS(&tp[0]))));
 			break;
 		case DH6OPT_IA_NA:
 		case DH6OPT_IA_PD:
 			if (optlen < 12) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, " IAID:%u T1:%u T2:%u",
 			    EXTRACT_32BITS(&tp[0]),
 			    EXTRACT_32BITS(&tp[4]),
 			    EXTRACT_32BITS(&tp[8])));
 			if (optlen > 12) {
 				/* there are sub-options */
 				dhcp6opt_print(ndo, tp + 12, tp + optlen);
 			}
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_IA_TA:
 			if (optlen < 4) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, " IAID:%u", EXTRACT_32BITS(tp)));
 			if (optlen > 4) {
 				/* there are sub-options */
 				dhcp6opt_print(ndo, tp + 4, tp + optlen);
 			}
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_IA_PD_PREFIX:
 			if (optlen < 25) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, " %s/%d", ip6addr_string(ndo, &tp[9]), tp[8]));
 			ND_PRINT((ndo, " pltime:%u vltime:%u",
 			    EXTRACT_32BITS(&tp[0]),
 			    EXTRACT_32BITS(&tp[4])));
 			if (optlen > 25) {
 				/* there are sub-options */
 				dhcp6opt_print(ndo, tp + 25, tp + optlen);
 			}
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_LIFETIME:
 		case DH6OPT_CLT_TIME:
 			if (optlen != 4) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, " %d)", EXTRACT_32BITS(tp)));
 			break;
 		case DH6OPT_REMOTE_ID:
 			if (optlen < 4) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, " %d ", EXTRACT_32BITS(tp)));
 			/*
 			 * Print hex dump first 10 characters.
 			 */
 			for (i = 4; i < optlen && i < 14; i++)
 				ND_PRINT((ndo, "%02x", tp[i]));
 			ND_PRINT((ndo, "...)"));
 			break;
 		case DH6OPT_LQ_QUERY:
 			if (optlen < 17) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			switch (*tp) {
 			case 1:
 				ND_PRINT((ndo, " by-address"));
 				break;
 			case 2:
 				ND_PRINT((ndo, " by-clientID"));
 				break;
 			default:
 				ND_PRINT((ndo, " type_%d", (int)*tp));
 				break;
 			}
 			ND_PRINT((ndo, " %s", ip6addr_string(ndo, &tp[1])));
 			if (optlen > 17) {
 				/* there are query-options */
 				dhcp6opt_print(ndo, tp + 17, tp + optlen);
 			}
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_CLIENT_DATA:
 			tp = (const u_char *)(dh6o + 1);
 			if (optlen > 0) {
 				/* there are encapsulated options */
 				dhcp6opt_print(ndo, tp, tp + optlen);
 			}
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_LQ_RELAY_DATA:
 			if (optlen < 16) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, " %s ", ip6addr_string(ndo, &tp[0])));
 			/*
 			 * Print hex dump first 10 characters.
 			 */
 			for (i = 16; i < optlen && i < 26; i++)
 				ND_PRINT((ndo, "%02x", tp[i]));
 			ND_PRINT((ndo, "...)"));
 			break;
 		case DH6OPT_NTP_SERVER:
 			if (optlen < 4) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			while (tp < cp + sizeof(*dh6o) + optlen - 4) {
 				subopt_code = EXTRACT_16BITS(tp);
 				tp += 2;
 				subopt_len = EXTRACT_16BITS(tp);
 				tp += 2;
 				if (tp + subopt_len > cp + sizeof(*dh6o) + optlen)
 					goto trunc;
 				ND_PRINT((ndo, " subopt:%d", subopt_code));
 				switch (subopt_code) {
 				case DH6OPT_NTP_SUBOPTION_SRV_ADDR:
 				case DH6OPT_NTP_SUBOPTION_MC_ADDR:
 					if (subopt_len != 16) {
 						ND_PRINT((ndo, " ?"));
 						break;
 					}
 					ND_PRINT((ndo, " %s", ip6addr_string(ndo, &tp[0])));
 					break;
 				case DH6OPT_NTP_SUBOPTION_SRV_FQDN:
 					ND_PRINT((ndo, " "));
 					if (ns_nprint(ndo, tp, tp + subopt_len) == NULL)
 						goto trunc;
 					break;
 				default:
 					ND_PRINT((ndo, " ?"));
 					break;
 				}
 				tp += subopt_len;
 			}
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_AFTR_NAME:
 			if (optlen < 3) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			remain_len = optlen;
 			ND_PRINT((ndo, " "));
 			/* Encoding is described in section 3.1 of RFC 1035 */
 			while (remain_len && *tp) {
 				label_len =  *tp++;
 				if (label_len < remain_len - 1) {
 					(void)fn_printn(ndo, tp, label_len, NULL);
 					tp += label_len;
 					remain_len -= (label_len + 1);
 					if(*tp) ND_PRINT((ndo, "."));
 				} else {
 					ND_PRINT((ndo, " ?"));
 					break;
 				}
 			}
 			ND_PRINT((ndo, ")"));
 			break;
 		case DH6OPT_NEW_POSIX_TIMEZONE: /* all three of these options */
 		case DH6OPT_NEW_TZDB_TIMEZONE:	/* are encoded similarly */
 		case DH6OPT_MUDURL:		/* although GMT might not work */
 		        if (optlen < 5) {
 				ND_PRINT((ndo, " ?)"));
 				break;
 			}
 			tp = (const u_char *)(dh6o + 1);
 			ND_PRINT((ndo, "="));
 			(void)fn_printn(ndo, tp, (u_int)optlen, NULL);
 			ND_PRINT((ndo, ")"));
 			break;

 		default:
 			ND_PRINT((ndo, ")"));
 			break;
 		}

 		cp += sizeof(*dh6o) + optlen;
 	}
 	return;

 trunc:
 	ND_PRINT((ndo, "[|dhcp6ext]"));
 }

 /*
  * Print dhcp6 packets
  */
 void
 dhcp6_print(netdissect_options *ndo,
             const u_char *cp, u_int length)
 {
 	const struct dhcp6 *dh6;
 	const struct dhcp6_relay *dh6relay;
 	const u_char *ep;
 	const u_char *extp;
 	const char *name;

 	ND_PRINT((ndo, "dhcp6"));

 	ep = (const u_char *)ndo->ndo_snapend;
 	if (cp + length < ep)
 		ep = cp + length;

 	dh6 = (const struct dhcp6 *)cp;
 	dh6relay = (const struct dhcp6_relay *)cp;
 	ND_TCHECK(dh6->dh6_xid);
 	name = tok2str(dh6_msgtype_str, "msgtype-%u", dh6->dh6_msgtype);

 	if (!ndo->ndo_vflag) {
 		ND_PRINT((ndo, " %s", name));
 		return;
 	}

 	/* XXX relay agent messages have to be handled differently */

 	ND_PRINT((ndo, " %s (", name));	/*)*/
 	if (dh6->dh6_msgtype != DH6_RELAY_FORW &&
 	    dh6->dh6_msgtype != DH6_RELAY_REPLY) {
 		ND_PRINT((ndo, "xid=%x", EXTRACT_32BITS(&dh6->dh6_xid) & DH6_XIDMASK));
 		extp = (const u_char *)(dh6 + 1);
 		dhcp6opt_print(ndo, extp, ep);
 	} else {		/* relay messages */
 		struct in6_addr addr6;

 		ND_TCHECK(dh6relay->dh6relay_peeraddr);

 		memcpy(&addr6, dh6relay->dh6relay_linkaddr, sizeof (addr6));
 		ND_PRINT((ndo, "linkaddr=%s", ip6addr_string(ndo, &addr6)));

 		memcpy(&addr6, dh6relay->dh6relay_peeraddr, sizeof (addr6));
 		ND_PRINT((ndo, " peeraddr=%s", ip6addr_string(ndo, &addr6)));

 		dhcp6opt_print(ndo, (const u_char *)(dh6relay + 1), ep);
 	}
 	/*(*/
 	ND_PRINT((ndo, ")"));
 	return;

 trunc:
 	ND_PRINT((ndo, "[|dhcp6]"));
 }
	/*
	* Copyright (C) 1998 and 1999 WIDE Project.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. Neither the name of the project 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 BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	*/

	/* \summary: IPv6 DHCP printer */

	/*
	* RFC3315: DHCPv6
	* supported DHCPv6 options:
	* RFC3319: Session Initiation Protocol (SIP) Servers options,
	* RFC3633: IPv6 Prefix options,
	* RFC3646: DNS Configuration options,
	* RFC3898: Network Information Service (NIS) Configuration options,
	* RFC4075: Simple Network Time Protocol (SNTP) Configuration option,
	* RFC4242: Information Refresh Time option,
	* RFC4280: Broadcast and Multicast Control Servers options,
	* RFC5908: Network Time Protocol (NTP) Server Option for DHCPv6
	* RFC6334: Dual-Stack Lite option,
	*/

	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#endif

	#include <netdissect-stdinc.h>

	#include <stdio.h>
	#include <string.h>

	#include "netdissect.h"
	#include "addrtoname.h"
	#include "extract.h"

	/* lease duration */
	#define DHCP6_DURATION_INFINITE 0xffffffff

	/* Error Values */
	#define DH6ERR_FAILURE 16
	#define DH6ERR_AUTHFAIL 17
	#define DH6ERR_POORLYFORMED 18
	#define DH6ERR_UNAVAIL 19
	#define DH6ERR_OPTUNAVAIL 20

	/* Message type */
	#define DH6_SOLICIT 1
	#define DH6_ADVERTISE 2
	#define DH6_REQUEST 3
	#define DH6_CONFIRM 4
	#define DH6_RENEW 5
	#define DH6_REBIND 6
	#define DH6_REPLY 7
	#define DH6_RELEASE 8
	#define DH6_DECLINE 9
	#define DH6_RECONFIGURE 10
	#define DH6_INFORM_REQ 11
	#define DH6_RELAY_FORW 12
	#define DH6_RELAY_REPLY 13
	#define DH6_LEASEQUERY 14
	#define DH6_LQ_REPLY 15

	static const struct tok dh6_msgtype_str[] = {
	{ DH6_SOLICIT, "solicit" },
	{ DH6_ADVERTISE, "advertise" },
	{ DH6_REQUEST, "request" },
	{ DH6_CONFIRM, "confirm" },
	{ DH6_RENEW, "renew" },
	{ DH6_REBIND, "rebind" },
	{ DH6_REPLY, "reply" },
	{ DH6_RELEASE, "release" },
	{ DH6_DECLINE, "decline" },
	{ DH6_RECONFIGURE, "reconfigure" },
	{ DH6_INFORM_REQ, "inf-req" },
	{ DH6_RELAY_FORW, "relay-fwd" },
	{ DH6_RELAY_REPLY, "relay-reply" },
	{ DH6_LEASEQUERY, "leasequery" },
	{ DH6_LQ_REPLY, "leasequery-reply" },
	{ 0, NULL }
	};

	/* DHCP6 base packet format */
	struct dhcp6 {
	union {
	nd_uint8_t m;
	nd_uint32_t x;
	} dh6_msgtypexid;
	/* options follow */
	};
	#define dh6_msgtype dh6_msgtypexid.m
	#define dh6_xid dh6_msgtypexid.x
	#define DH6_XIDMASK 0x00ffffff

	/* DHCPv6 relay messages */
	struct dhcp6_relay {
	nd_uint8_t dh6relay_msgtype;
	nd_uint8_t dh6relay_hcnt;
	nd_uint8_t dh6relay_linkaddr[16]; /* XXX: badly aligned */
	nd_uint8_t dh6relay_peeraddr[16];
	/* options follow */
	};

	/* options */
	#define DH6OPT_CLIENTID 1
	#define DH6OPT_SERVERID 2
	#define DH6OPT_IA_NA 3
	#define DH6OPT_IA_TA 4
	#define DH6OPT_IA_ADDR 5
	#define DH6OPT_ORO 6
	#define DH6OPT_PREFERENCE 7
	# define DH6OPT_PREF_MAX 255
	#define DH6OPT_ELAPSED_TIME 8
	#define DH6OPT_RELAY_MSG 9
	/#define DH6OPT_SERVER_MSG 10 deprecated /
	#define DH6OPT_AUTH 11
	# define DH6OPT_AUTHPROTO_DELAYED 2
	# define DH6OPT_AUTHPROTO_RECONFIG 3
	# define DH6OPT_AUTHALG_HMACMD5 1
	# define DH6OPT_AUTHRDM_MONOCOUNTER 0
	# define DH6OPT_AUTHRECONFIG_KEY 1
	# define DH6OPT_AUTHRECONFIG_HMACMD5 2
	#define DH6OPT_UNICAST 12
	#define DH6OPT_STATUS_CODE 13
	# define DH6OPT_STCODE_SUCCESS 0
	# define DH6OPT_STCODE_UNSPECFAIL 1
	# define DH6OPT_STCODE_NOADDRAVAIL 2
	# define DH6OPT_STCODE_NOBINDING 3
	# define DH6OPT_STCODE_NOTONLINK 4
	# define DH6OPT_STCODE_USEMULTICAST 5
	# define DH6OPT_STCODE_NOPREFIXAVAIL 6
	# define DH6OPT_STCODE_UNKNOWNQUERYTYPE 7
	# define DH6OPT_STCODE_MALFORMEDQUERY 8
	# define DH6OPT_STCODE_NOTCONFIGURED 9
	# define DH6OPT_STCODE_NOTALLOWED 10
	#define DH6OPT_RAPID_COMMIT 14
	#define DH6OPT_USER_CLASS 15
	#define DH6OPT_VENDOR_CLASS 16
	#define DH6OPT_VENDOR_OPTS 17
	#define DH6OPT_INTERFACE_ID 18
	#define DH6OPT_RECONF_MSG 19
	#define DH6OPT_RECONF_ACCEPT 20
	#define DH6OPT_SIP_SERVER_D 21
	#define DH6OPT_SIP_SERVER_A 22
	#define DH6OPT_DNS_SERVERS 23
	#define DH6OPT_DOMAIN_LIST 24
	#define DH6OPT_IA_PD 25
	#define DH6OPT_IA_PD_PREFIX 26
	#define DH6OPT_NIS_SERVERS 27
	#define DH6OPT_NISP_SERVERS 28
	#define DH6OPT_NIS_NAME 29
	#define DH6OPT_NISP_NAME 30
	#define DH6OPT_SNTP_SERVERS 31
	#define DH6OPT_LIFETIME 32
	#define DH6OPT_BCMCS_SERVER_D 33
	#define DH6OPT_BCMCS_SERVER_A 34
	#define DH6OPT_GEOCONF_CIVIC 36
	#define DH6OPT_REMOTE_ID 37
	#define DH6OPT_SUBSCRIBER_ID 38
	#define DH6OPT_CLIENT_FQDN 39
	#define DH6OPT_PANA_AGENT 40
	#define DH6OPT_NEW_POSIX_TIMEZONE 41
	#define DH6OPT_NEW_TZDB_TIMEZONE 42
	#define DH6OPT_ERO 43
	#define DH6OPT_LQ_QUERY 44
	#define DH6OPT_CLIENT_DATA 45
	#define DH6OPT_CLT_TIME 46
	#define DH6OPT_LQ_RELAY_DATA 47
	#define DH6OPT_LQ_CLIENT_LINK 48
	#define DH6OPT_NTP_SERVER 56
	# define DH6OPT_NTP_SUBOPTION_SRV_ADDR 1
	# define DH6OPT_NTP_SUBOPTION_MC_ADDR 2
	# define DH6OPT_NTP_SUBOPTION_SRV_FQDN 3
	#define DH6OPT_AFTR_NAME 64
	#define DH6OPT_MUDURL 112

	static const struct tok dh6opt_str[] = {
	{ DH6OPT_CLIENTID, "client-ID" },
	{ DH6OPT_SERVERID, "server-ID" },
	{ DH6OPT_IA_NA, "IA_NA" },
	{ DH6OPT_IA_TA, "IA_TA" },
	{ DH6OPT_IA_ADDR, "IA_ADDR" },
	{ DH6OPT_ORO, "option-request" },
	{ DH6OPT_PREFERENCE, "preference" },
	{ DH6OPT_ELAPSED_TIME, "elapsed-time" },
	{ DH6OPT_RELAY_MSG, "relay-message" },
	{ DH6OPT_AUTH, "authentication" },
	{ DH6OPT_UNICAST, "server-unicast" },
	{ DH6OPT_STATUS_CODE, "status-code" },
	{ DH6OPT_RAPID_COMMIT, "rapid-commit" },
	{ DH6OPT_USER_CLASS, "user-class" },
	{ DH6OPT_VENDOR_CLASS, "vendor-class" },
	{ DH6OPT_VENDOR_OPTS, "vendor-specific-info" },
	{ DH6OPT_INTERFACE_ID, "interface-ID" },
	{ DH6OPT_RECONF_MSG, "reconfigure-message" },
	{ DH6OPT_RECONF_ACCEPT, "reconfigure-accept" },
	{ DH6OPT_SIP_SERVER_D, "SIP-servers-domain" },
	{ DH6OPT_SIP_SERVER_A, "SIP-servers-address" },
	{ DH6OPT_DNS_SERVERS, "DNS-server" },
	{ DH6OPT_DOMAIN_LIST, "DNS-search-list" },
	{ DH6OPT_IA_PD, "IA_PD" },
	{ DH6OPT_IA_PD_PREFIX, "IA_PD-prefix" },
	{ DH6OPT_SNTP_SERVERS, "SNTP-servers" },
	{ DH6OPT_LIFETIME, "lifetime" },
	{ DH6OPT_NIS_SERVERS, "NIS-server" },
	{ DH6OPT_NISP_SERVERS, "NIS+-server" },
	{ DH6OPT_NIS_NAME, "NIS-domain-name" },
	{ DH6OPT_NISP_NAME, "NIS+-domain-name" },
	{ DH6OPT_BCMCS_SERVER_D, "BCMCS-domain-name" },
	{ DH6OPT_BCMCS_SERVER_A, "BCMCS-server" },
	{ DH6OPT_GEOCONF_CIVIC, "Geoconf-Civic" },
	{ DH6OPT_REMOTE_ID, "Remote-ID" },
	{ DH6OPT_SUBSCRIBER_ID, "Subscriber-ID" },
	{ DH6OPT_CLIENT_FQDN, "Client-FQDN" },
	{ DH6OPT_PANA_AGENT, "PANA-agent" },
	{ DH6OPT_NEW_POSIX_TIMEZONE, "POSIX-timezone" },
	{ DH6OPT_NEW_TZDB_TIMEZONE, "POSIX-tz-database" },
	{ DH6OPT_ERO, "Echo-request-option" },
	{ DH6OPT_LQ_QUERY, "Lease-query" },
	{ DH6OPT_CLIENT_DATA, "LQ-client-data" },
	{ DH6OPT_CLT_TIME, "Clt-time" },
	{ DH6OPT_LQ_RELAY_DATA, "LQ-relay-data" },
	{ DH6OPT_LQ_CLIENT_LINK, "LQ-client-link" },
	{ DH6OPT_NTP_SERVER, "NTP-server" },
	{ DH6OPT_AFTR_NAME, "AFTR-Name" },
	{ DH6OPT_MUDURL, "MUD-URL" },
	{ 0, NULL }
	};

	static const struct tok dh6opt_stcode_str[] = {
	{ DH6OPT_STCODE_SUCCESS, "Success" }, /* RFC3315 */
	{ DH6OPT_STCODE_UNSPECFAIL, "UnspecFail" }, /* RFC3315 */
	{ DH6OPT_STCODE_NOADDRAVAIL, "NoAddrsAvail" }, /* RFC3315 */
	{ DH6OPT_STCODE_NOBINDING, "NoBinding" }, /* RFC3315 */
	{ DH6OPT_STCODE_NOTONLINK, "NotOnLink" }, /* RFC3315 */
	{ DH6OPT_STCODE_USEMULTICAST, "UseMulticast" }, /* RFC3315 */
	{ DH6OPT_STCODE_NOPREFIXAVAIL, "NoPrefixAvail" }, /* RFC3633 */
	{ DH6OPT_STCODE_UNKNOWNQUERYTYPE, "UnknownQueryType" }, /* RFC5007 */
	{ DH6OPT_STCODE_MALFORMEDQUERY, "MalformedQuery" }, /* RFC5007 */
	{ DH6OPT_STCODE_NOTCONFIGURED, "NotConfigured" }, /* RFC5007 */
	{ DH6OPT_STCODE_NOTALLOWED, "NotAllowed" }, /* RFC5007 */
	{ 0, NULL }
	};

	struct dhcp6opt {
	nd_uint16_t dh6opt_type;
	nd_uint16_t dh6opt_len;
	/* type-dependent data follows */
	};

	static const char *
	dhcp6stcode(const uint16_t code)
	{
	return code > 255 ? "INVALID code" : tok2str(dh6opt_stcode_str, "code%u", code);
	}

	static void
	dhcp6opt_print(netdissect_options *ndo,
	const u_char cp, const u_char ep)
	{
	const struct dhcp6opt *dh6o;
	const u_char *tp;
	size_t i;
	uint16_t opttype;
	size_t optlen;
	uint8_t auth_proto;
	u_int authinfolen, authrealmlen;
	int remain_len; /* Length of remaining options */
	int label_len; /* Label length */
	uint16_t subopt_code;
	uint16_t subopt_len;

	if (cp == ep)
	return;
	while (cp < ep) {
	if (ep < cp + sizeof(*dh6o))
	goto trunc;
	dh6o = (const struct dhcp6opt *)cp;
	ND_TCHECK(*dh6o);
	optlen = EXTRACT_16BITS(&dh6o->dh6opt_len);
	if (ep < cp + sizeof(*dh6o) + optlen)
	goto trunc;
	opttype = EXTRACT_16BITS(&dh6o->dh6opt_type);
	ND_PRINT((ndo, " (%s", tok2str(dh6opt_str, "opt_%u", opttype)));
	ND_TCHECK2((cp + sizeof(dh6o)), optlen);
	switch (opttype) {
	case DH6OPT_CLIENTID:
	case DH6OPT_SERVERID:
	if (optlen < 2) {
	/(/
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	switch (EXTRACT_16BITS(tp)) {
	case 1:
	if (optlen >= 2 + 6) {
	ND_PRINT((ndo, " hwaddr/time type %u time %u ",
	EXTRACT_16BITS(&tp[2]),
	EXTRACT_32BITS(&tp[4])));
	for (i = 8; i < optlen; i++)
	ND_PRINT((ndo, "%02x", tp[i]));
	/(/
	ND_PRINT((ndo, ")"));
	} else {
	/(/
	ND_PRINT((ndo, " ?)"));
	}
	break;
	case 2:
	if (optlen >= 2 + 8) {
	ND_PRINT((ndo, " vid "));
	for (i = 2; i < 2 + 8; i++)
	ND_PRINT((ndo, "%02x", tp[i]));
	/(/
	ND_PRINT((ndo, ")"));
	} else {
	/(/
	ND_PRINT((ndo, " ?)"));
	}
	break;
	case 3:
	if (optlen >= 2 + 2) {
	ND_PRINT((ndo, " hwaddr type %u ",
	EXTRACT_16BITS(&tp[2])));
	for (i = 4; i < optlen; i++)
	ND_PRINT((ndo, "%02x", tp[i]));
	/(/
	ND_PRINT((ndo, ")"));
	} else {
	/(/
	ND_PRINT((ndo, " ?)"));
	}
	break;
	default:
	ND_PRINT((ndo, " type %d)", EXTRACT_16BITS(tp)));
	break;
	}
	break;
	case DH6OPT_IA_ADDR:
	if (optlen < 24) {
	/(/
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, " %s", ip6addr_string(ndo, &tp[0])));
	ND_PRINT((ndo, " pltime:%u vltime:%u",
	EXTRACT_32BITS(&tp[16]),
	EXTRACT_32BITS(&tp[20])));
	if (optlen > 24) {
	/* there are sub-options */
	dhcp6opt_print(ndo, tp + 24, tp + optlen);
	}
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_ORO:
	case DH6OPT_ERO:
	if (optlen % 2) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	for (i = 0; i < optlen; i += 2) {
	ND_PRINT((ndo, " %s",
	tok2str(dh6opt_str, "opt_%u", EXTRACT_16BITS(&tp[i]))));
	}
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_PREFERENCE:
	if (optlen != 1) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, " %d)", *tp));
	break;
	case DH6OPT_ELAPSED_TIME:
	if (optlen != 2) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, " %d)", EXTRACT_16BITS(tp)));
	break;
	case DH6OPT_RELAY_MSG:
	ND_PRINT((ndo, " ("));
	tp = (const u_char *)(dh6o + 1);
	dhcp6_print(ndo, tp, optlen);
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_AUTH:
	if (optlen < 11) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	auth_proto = *tp;
	switch (auth_proto) {
	case DH6OPT_AUTHPROTO_DELAYED:
	ND_PRINT((ndo, " proto: delayed"));
	break;
	case DH6OPT_AUTHPROTO_RECONFIG:
	ND_PRINT((ndo, " proto: reconfigure"));
	break;
	default:
	ND_PRINT((ndo, " proto: %d", auth_proto));
	break;
	}
	tp++;
	switch (*tp) {
	case DH6OPT_AUTHALG_HMACMD5:
	/* XXX: may depend on the protocol */
	ND_PRINT((ndo, ", alg: HMAC-MD5"));
	break;
	default:
	ND_PRINT((ndo, ", alg: %d", *tp));
	break;
	}
	tp++;
	switch (*tp) {
	case DH6OPT_AUTHRDM_MONOCOUNTER:
	ND_PRINT((ndo, ", RDM: mono"));
	break;
	default:
	ND_PRINT((ndo, ", RDM: %d", *tp));
	break;
	}
	tp++;
	ND_PRINT((ndo, ", RD:"));
	for (i = 0; i < 4; i++, tp += 2)
	ND_PRINT((ndo, " %04x", EXTRACT_16BITS(tp)));

	/* protocol dependent part */
	authinfolen = optlen - 11;
	switch (auth_proto) {
	case DH6OPT_AUTHPROTO_DELAYED:
	if (authinfolen == 0)
	break;
	if (authinfolen < 20) {
	ND_PRINT((ndo, " ??"));
	break;
	}
	authrealmlen = authinfolen - 20;
	if (authrealmlen > 0) {
	ND_PRINT((ndo, ", realm: "));
	}
	for (i = 0; i < authrealmlen; i++, tp++)
	ND_PRINT((ndo, "%02x", *tp));
	ND_PRINT((ndo, ", key ID: %08x", EXTRACT_32BITS(tp)));
	tp += 4;
	ND_PRINT((ndo, ", HMAC-MD5:"));
	for (i = 0; i < 4; i++, tp+= 4)
	ND_PRINT((ndo, " %08x", EXTRACT_32BITS(tp)));
	break;
	case DH6OPT_AUTHPROTO_RECONFIG:
	if (authinfolen != 17) {
	ND_PRINT((ndo, " ??"));
	break;
	}
	switch (*tp++) {
	case DH6OPT_AUTHRECONFIG_KEY:
	ND_PRINT((ndo, " reconfig-key"));
	break;
	case DH6OPT_AUTHRECONFIG_HMACMD5:
	ND_PRINT((ndo, " type: HMAC-MD5"));
	break;
	default:
	ND_PRINT((ndo, " type: ??"));
	break;
	}
	ND_PRINT((ndo, " value:"));
	for (i = 0; i < 4; i++, tp+= 4)
	ND_PRINT((ndo, " %08x", EXTRACT_32BITS(tp)));
	break;
	default:
	ND_PRINT((ndo, " ??"));
	break;
	}

	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_RAPID_COMMIT: /* nothing todo */
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_INTERFACE_ID:
	case DH6OPT_SUBSCRIBER_ID:
	/*
	* Since we cannot predict the encoding, print hex dump
	* at most 10 characters.
	*/
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, " "));
	for (i = 0; i < optlen && i < 10; i++)
	ND_PRINT((ndo, "%02x", tp[i]));
	ND_PRINT((ndo, "...)"));
	break;
	case DH6OPT_RECONF_MSG:
	if (optlen != 1) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	switch (*tp) {
	case DH6_RENEW:
	ND_PRINT((ndo, " for renew)"));
	break;
	case DH6_INFORM_REQ:
	ND_PRINT((ndo, " for inf-req)"));
	break;
	default:
	ND_PRINT((ndo, " for ?\?\?(%02x))", *tp));
	break;
	}
	break;
	case DH6OPT_RECONF_ACCEPT: /* nothing todo */
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_SIP_SERVER_A:
	case DH6OPT_DNS_SERVERS:
	case DH6OPT_SNTP_SERVERS:
	case DH6OPT_NIS_SERVERS:
	case DH6OPT_NISP_SERVERS:
	case DH6OPT_BCMCS_SERVER_A:
	case DH6OPT_PANA_AGENT:
	case DH6OPT_LQ_CLIENT_LINK:
	if (optlen % 16) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	for (i = 0; i < optlen; i += 16)
	ND_PRINT((ndo, " %s", ip6addr_string(ndo, &tp[i])));
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_SIP_SERVER_D:
	case DH6OPT_DOMAIN_LIST:
	tp = (const u_char *)(dh6o + 1);
	while (tp < cp + sizeof(*dh6o) + optlen) {
	ND_PRINT((ndo, " "));
	if ((tp = ns_nprint(ndo, tp, cp + sizeof(*dh6o) + optlen)) == NULL)
	goto trunc;
	}
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_STATUS_CODE:
	if (optlen < 2) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, " %s)", dhcp6stcode(EXTRACT_16BITS(&tp[0]))));
	break;
	case DH6OPT_IA_NA:
	case DH6OPT_IA_PD:
	if (optlen < 12) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, " IAID:%u T1:%u T2:%u",
	EXTRACT_32BITS(&tp[0]),
	EXTRACT_32BITS(&tp[4]),
	EXTRACT_32BITS(&tp[8])));
	if (optlen > 12) {
	/* there are sub-options */
	dhcp6opt_print(ndo, tp + 12, tp + optlen);
	}
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_IA_TA:
	if (optlen < 4) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, " IAID:%u", EXTRACT_32BITS(tp)));
	if (optlen > 4) {
	/* there are sub-options */
	dhcp6opt_print(ndo, tp + 4, tp + optlen);
	}
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_IA_PD_PREFIX:
	if (optlen < 25) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, " %s/%d", ip6addr_string(ndo, &tp[9]), tp[8]));
	ND_PRINT((ndo, " pltime:%u vltime:%u",
	EXTRACT_32BITS(&tp[0]),
	EXTRACT_32BITS(&tp[4])));
	if (optlen > 25) {
	/* there are sub-options */
	dhcp6opt_print(ndo, tp + 25, tp + optlen);
	}
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_LIFETIME:
	case DH6OPT_CLT_TIME:
	if (optlen != 4) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, " %d)", EXTRACT_32BITS(tp)));
	break;
	case DH6OPT_REMOTE_ID:
	if (optlen < 4) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, " %d ", EXTRACT_32BITS(tp)));
	/*
	* Print hex dump first 10 characters.
	*/
	for (i = 4; i < optlen && i < 14; i++)
	ND_PRINT((ndo, "%02x", tp[i]));
	ND_PRINT((ndo, "...)"));
	break;
	case DH6OPT_LQ_QUERY:
	if (optlen < 17) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	switch (*tp) {
	case 1:
	ND_PRINT((ndo, " by-address"));
	break;
	case 2:
	ND_PRINT((ndo, " by-clientID"));
	break;
	default:
	ND_PRINT((ndo, " type_%d", (int)*tp));
	break;
	}
	ND_PRINT((ndo, " %s", ip6addr_string(ndo, &tp[1])));
	if (optlen > 17) {
	/* there are query-options */
	dhcp6opt_print(ndo, tp + 17, tp + optlen);
	}
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_CLIENT_DATA:
	tp = (const u_char *)(dh6o + 1);
	if (optlen > 0) {
	/* there are encapsulated options */
	dhcp6opt_print(ndo, tp, tp + optlen);
	}
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_LQ_RELAY_DATA:
	if (optlen < 16) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, " %s ", ip6addr_string(ndo, &tp[0])));
	/*
	* Print hex dump first 10 characters.
	*/
	for (i = 16; i < optlen && i < 26; i++)
	ND_PRINT((ndo, "%02x", tp[i]));
	ND_PRINT((ndo, "...)"));
	break;
	case DH6OPT_NTP_SERVER:
	if (optlen < 4) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	while (tp < cp + sizeof(*dh6o) + optlen - 4) {
	subopt_code = EXTRACT_16BITS(tp);
	tp += 2;
	subopt_len = EXTRACT_16BITS(tp);
	tp += 2;
	if (tp + subopt_len > cp + sizeof(*dh6o) + optlen)
	goto trunc;
	ND_PRINT((ndo, " subopt:%d", subopt_code));
	switch (subopt_code) {
	case DH6OPT_NTP_SUBOPTION_SRV_ADDR:
	case DH6OPT_NTP_SUBOPTION_MC_ADDR:
	if (subopt_len != 16) {
	ND_PRINT((ndo, " ?"));
	break;
	}
	ND_PRINT((ndo, " %s", ip6addr_string(ndo, &tp[0])));
	break;
	case DH6OPT_NTP_SUBOPTION_SRV_FQDN:
	ND_PRINT((ndo, " "));
	if (ns_nprint(ndo, tp, tp + subopt_len) == NULL)
	goto trunc;
	break;
	default:
	ND_PRINT((ndo, " ?"));
	break;
	}
	tp += subopt_len;
	}
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_AFTR_NAME:
	if (optlen < 3) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	remain_len = optlen;
	ND_PRINT((ndo, " "));
	/* Encoding is described in section 3.1 of RFC 1035 */
	while (remain_len && *tp) {
	label_len = *tp++;
	if (label_len < remain_len - 1) {
	(void)fn_printn(ndo, tp, label_len, NULL);
	tp += label_len;
	remain_len -= (label_len + 1);
	if(*tp) ND_PRINT((ndo, "."));
	} else {
	ND_PRINT((ndo, " ?"));
	break;
	}
	}
	ND_PRINT((ndo, ")"));
	break;
	case DH6OPT_NEW_POSIX_TIMEZONE: /* all three of these options */
	case DH6OPT_NEW_TZDB_TIMEZONE: /* are encoded similarly */
	case DH6OPT_MUDURL: /* although GMT might not work */
	if (optlen < 5) {
	ND_PRINT((ndo, " ?)"));
	break;
	}
	tp = (const u_char *)(dh6o + 1);
	ND_PRINT((ndo, "="));
	(void)fn_printn(ndo, tp, (u_int)optlen, NULL);
	ND_PRINT((ndo, ")"));
	break;

	default:
	ND_PRINT((ndo, ")"));
	break;
	}

	cp += sizeof(*dh6o) + optlen;
	}
	return;

	trunc:
	ND_PRINT((ndo, "[\|dhcp6ext]"));
	}

	/*
	* Print dhcp6 packets
	*/
	void
	dhcp6_print(netdissect_options *ndo,
	const u_char *cp, u_int length)
	{
	const struct dhcp6 *dh6;
	const struct dhcp6_relay *dh6relay;
	const u_char *ep;
	const u_char *extp;
	const char *name;

	ND_PRINT((ndo, "dhcp6"));

	ep = (const u_char *)ndo->ndo_snapend;
	if (cp + length < ep)
	ep = cp + length;

	dh6 = (const struct dhcp6 *)cp;
	dh6relay = (const struct dhcp6_relay *)cp;
	ND_TCHECK(dh6->dh6_xid);
	name = tok2str(dh6_msgtype_str, "msgtype-%u", dh6->dh6_msgtype);

	if (!ndo->ndo_vflag) {
	ND_PRINT((ndo, " %s", name));
	return;
	}

	/* XXX relay agent messages have to be handled differently */

	ND_PRINT((ndo, " %s (", name)); /)/
	if (dh6->dh6_msgtype != DH6_RELAY_FORW &&
	dh6->dh6_msgtype != DH6_RELAY_REPLY) {
	ND_PRINT((ndo, "xid=%x", EXTRACT_32BITS(&dh6->dh6_xid) & DH6_XIDMASK));
	extp = (const u_char *)(dh6 + 1);
	dhcp6opt_print(ndo, extp, ep);
	} else { /* relay messages */
	struct in6_addr addr6;

	ND_TCHECK(dh6relay->dh6relay_peeraddr);

	memcpy(&addr6, dh6relay->dh6relay_linkaddr, sizeof (addr6));
	ND_PRINT((ndo, "linkaddr=%s", ip6addr_string(ndo, &addr6)));

	memcpy(&addr6, dh6relay->dh6relay_peeraddr, sizeof (addr6));
	ND_PRINT((ndo, " peeraddr=%s", ip6addr_string(ndo, &addr6)));

	dhcp6opt_print(ndo, (const u_char *)(dh6relay + 1), ep);
	}
	/(/
	ND_PRINT((ndo, ")"));
	return;

	trunc:
	ND_PRINT((ndo, "[\|dhcp6]"));
	}