iputils/ninfod/ninfod_core.c - nest-cam/4320010/iputils-s20121221 - Git at Google

 /* $USAGI: ninfod_core.c,v 1.29 2003-07-16 09:49:01 yoshfuji Exp $ */
 /*
  * Copyright (C) 2002 USAGI/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.
  */
 /*
  * Author:
  * 	YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
  */

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

 #if HAVE_SYS_TYPES_H
 # include <sys/types.h>
 #endif
 #if STDC_HEADERS
 # include <stdio.h>
 # include <stdlib.h>
 # include <stddef.h>
 #else
 # if HAVE_STDLIB_H
 #  include <stdlib.h>
 # endif
 #endif
 #if ENABLE_THREADS && HAVE_PTHREAD_H
 # include <pthread.h>
 #endif
 #if HAVE_STRING_H
 # if !STDC_HEADERS && HAVE_MEMORY_H
 #  include <memory.h>
 # endif
 # include <string.h>
 #endif
 #if HAVE_STRINGS_H
 # include <strings.h>
 #endif
 #if HAVE_INTTYPES_H
 # include <inttypes.h>
 #else
 # if HAVE_STDINT_H
 #  include <stdint.h>
 # endif
 #endif
 #if HAVE_UNISTD_H
 # include <unistd.h>
 #endif

 #if TIME_WITH_SYS_TIME
 # include <sys/time.h>
 # include <time.h>
 #else
 # if HAVE_SYS_TIME_H
 #  include <sys/time.h>
 # else
 #  include <time.h>
 # endif
 #endif

 #if HAVE_SYS_UIO_H
 #include <sys/uio.h>
 #endif

 #if HAVE_NETINET_IN_H
 # include <netinet/in.h>
 #endif

 #if HAVE_NETINET_ICMP6_H
 # include <netinet/icmp6.h>
 #endif
 #ifndef HAVE_STRUCT_ICMP6_NODEINFO
 # include "icmp6_nodeinfo.h"
 #endif

 #if HAVE_NETDB_H
 # include <netdb.h>
 #endif
 #include <errno.h>

 #if HAVE_SYSLOG_H
 # include <syslog.h>
 #endif

 #include "ninfod.h"

 #ifndef offsetof
 # define offsetof(aggregate,member)	((size_t)&((aggregate *)0)->member)
 #endif

 #define ARRAY_SIZE(a)		(sizeof(a) / sizeof(a[0]))

 /* ---------- */
 /* ID */
 static char *RCSID __attribute__ ((unused)) = "$USAGI: ninfod_core.c,v 1.29 2003-07-16 09:49:01 yoshfuji Exp $";

 /* Variables */
 int initialized = 0;

 #if ENABLE_THREADS && HAVE_LIBPTHREAD
 pthread_attr_t pattr;
 #endif

 static uint32_t suptypes[(MAX_SUPTYPES+31)>>5];
 static size_t suptypes_len;

 /* ---------- */
 struct subjinfo {
 	uint8_t	code;
 	char	*name;
 	int	(*checksubj)(CHECKANDFILL_ARGS);
 	int	(*init)(INIT_ARGS);
 };

 static struct subjinfo subjinfo_table [] = {
 	[ICMP6_NI_SUBJ_IPV6] = {
 		.code = ICMP6_NI_SUBJ_IPV6,
 		.name = "IPv6",
 		//.init = init_nodeinfo_ipv6addr,
 		.checksubj = pr_nodeinfo_ipv6addr,
 	},
 	[ICMP6_NI_SUBJ_FQDN] = {
 		.code = ICMP6_NI_SUBJ_FQDN,
 		.name = "FQDN",
 		//.init = init_nodeinfo_nodename,
 		.checksubj = pr_nodeinfo_nodename,
 	},
 	[ICMP6_NI_SUBJ_IPV4] = {
 		.code = ICMP6_NI_SUBJ_IPV4,
 		.name = "IPv4",
 		//.init = init_nodeinfo_ipv4addr,
 		.checksubj = pr_nodeinfo_ipv4addr,
 	},
 };

 static struct subjinfo subjinfo_null = {
 	.name = "null",
 	.checksubj = pr_nodeinfo_noop,
 };

 static __inline__ struct subjinfo *subjinfo_lookup(int code)
 {
 	if (code >= ARRAY_SIZE(subjinfo_table))
 		return NULL;
 	if (subjinfo_table[code].name == NULL)
 		return NULL;
 	return &subjinfo_table[code];
 }

 /* ---------- */
 #define QTYPEINFO_F_RATELIMIT	0x1

 struct qtypeinfo {
 	uint16_t qtype;
 	char	*name;
 	int	(*getreply)(CHECKANDFILL_ARGS);
 	void	(*init)(INIT_ARGS);
 	int	flags;
 };

 static struct qtypeinfo qtypeinfo_table[] = {
 	[NI_QTYPE_NOOP]		= {
 		.qtype = NI_QTYPE_NOOP,
 		.name = "NOOP",
 		.getreply = pr_nodeinfo_noop,
 	},
 #if ENABLE_SUPTYPES
 	[NI_QTYPE_SUPTYPES]	= {
 		.qtype = NI_QTYPE_SUPTYPES,
 		.name = "SupTypes",
 		.getreply = pr_nodeinfo_suptypes,
 		.init = init_nodeinfo_suptypes,
 	},
 #endif
 	[NI_QTYPE_DNSNAME]	= {
 		.qtype = NI_QTYPE_DNSNAME,
 		.name = "DnsName",
 		.getreply = pr_nodeinfo_nodename,
 		.init = init_nodeinfo_nodename,
 	},
 	[NI_QTYPE_NODEADDR]	= {
 		.qtype = NI_QTYPE_NODEADDR,
 		.name = "NodeAddr",
 		.getreply = pr_nodeinfo_ipv6addr,
 		.init = init_nodeinfo_ipv6addr,
 	},
 	[NI_QTYPE_IPV4ADDR]	= {
 		.qtype = NI_QTYPE_IPV4ADDR,
 		.name = "IPv4Addr",
 		.getreply = pr_nodeinfo_ipv4addr,
 		.init = init_nodeinfo_ipv4addr,
 	},
 };

 static struct qtypeinfo qtypeinfo_unknown = {
 	.name = "unknown",
 	.getreply = pr_nodeinfo_unknown,
 	.flags = QTYPEINFO_F_RATELIMIT,
 };

 static struct qtypeinfo qtypeinfo_refused = {
 	.name = "refused",
 	.getreply = pr_nodeinfo_refused,
 	.flags = QTYPEINFO_F_RATELIMIT,
 };

 static __inline__ struct qtypeinfo *qtypeinfo_lookup(int qtype)
 {
 	if (qtype >= ARRAY_SIZE(qtypeinfo_table))
 		return &qtypeinfo_unknown;
 	if (qtypeinfo_table[qtype].name == NULL)
 		return &qtypeinfo_unknown;
 	return &qtypeinfo_table[qtype];
 }

 /* ---------- */
 /* noop */
 int pr_nodeinfo_noop(CHECKANDFILL_ARGS)
 {
 	DEBUG(LOG_DEBUG, "%s()\n", __func__);

 	if (subjlen) {
 		DEBUG(LOG_WARNING,
 		      "%s(): invalid subject length(%zu)\n",
 		      __func__, subjlen);
 		return 1;
 	}

 	if (reply) {
 		p->reply.ni_type = ICMP6_NI_REPLY;
 		p->reply.ni_code = ICMP6_NI_SUCCESS;
 		p->reply.ni_cksum = 0;
 		p->reply.ni_qtype = htons(NI_QTYPE_NOOP);
 		p->reply.ni_flags = flags;
 	}

 	if (subj_if)
 		*subj_if = 0;

 	return 0;
 }

 #if ENABLE_SUPTYPES
 /* suptypes */
 int pr_nodeinfo_suptypes(CHECKANDFILL_ARGS)
 {
 	DEBUG(LOG_DEBUG, "%s()\n", __func__);

 	if (subjlen) {
 		DEBUG(LOG_WARNING, "%s(): invalid subject length(%zu)\n",
 		      __func__, subjlen);
 		return 1;
 	}

 	if (reply) {
 		p->reply.ni_type = ICMP6_NI_REPLY;
 		p->reply.ni_code = ICMP6_NI_SUCCESS;
 		p->reply.ni_cksum = 0;
 		p->reply.ni_qtype = htons(NI_QTYPE_SUPTYPES);
 		p->reply.ni_flags = flags&~NI_SUPTYPE_FLAG_COMPRESS;

 		p->replydatalen = suptypes_len<<2;
 		p->replydata = ni_malloc(p->replydatalen);
 		if (p->replydata == NULL) {
 			p->replydatalen = -1;
 			return -1;	/*XXX*/
 		}

 		memcpy(p->replydata, suptypes, p->replydatalen);
 	}
 	return 0;
 }

 void init_nodeinfo_suptypes(INIT_ARGS)
 {
 	size_t w, b;
 	int i;

 	if (!forced && initialized)
 		return;

 	memset(suptypes, 0, sizeof(suptypes));
 	suptypes_len = 0;

 	for (i=0; i < ARRAY_SIZE(qtypeinfo_table); i++) {
 		unsigned short qtype;

 		if (qtypeinfo_table[i].name == NULL)
 			continue;
 		qtype = qtypeinfo_table[i].qtype;
 		w = qtype>>5;
 		b = qtype&0x1f;
 		if (w >= ARRAY_SIZE(suptypes)) {
 			/* This is programming error. */
 			DEBUG(LOG_ERR, "Warning: Too Large Supported Types\n");
 			exit(1);
 		}
 		suptypes[w] |= htonl(1<<b);

 		if (suptypes_len < w)
 			suptypes_len = w;
 	}
 	suptypes_len++;
 }
 #endif

 /* ---------- */
 /* unknown qtype response */
 int pr_nodeinfo_unknown(CHECKANDFILL_ARGS)
 {
 	if (!reply)
 		return -1;	/*???*/

 	p->reply.ni_type = ICMP6_NI_REPLY;
 	p->reply.ni_code = ICMP6_NI_UNKNOWN;
 	p->reply.ni_cksum = 0;
 	//p->reply.ni_qtype = 0;
 	p->reply.ni_flags = flags;

 	p->replydata = NULL;
 	p->replydatalen = 0;

 	return 0;
 }

 /* refused response */
 int pr_nodeinfo_refused(CHECKANDFILL_ARGS)
 {
 	if (!reply)
 		return -1;	/*???*/

 	p->reply.ni_type = ICMP6_NI_REPLY;
 	p->reply.ni_code = ICMP6_NI_REFUSED;
 	p->reply.ni_cksum = 0;
 	//p->reply.ni_qtype = 0;
 	p->reply.ni_flags = flags;

 	p->replydata = NULL;
 	p->replydatalen = 0;

 	return 0;
 }

 /* ---------- */
 /* Policy */
 static int ni_policy(struct packetcontext *p)
 {
 	const struct in6_addr *saddr = &((const struct sockaddr_in6 *)&p->addr)->sin6_addr;

 	/*
 	 * >0: reply
 	 *  0: refused
 	 * <0: discard
 	 */

 	/* Default policy is to refuse queries from
 	 * non-local addresses; loopback, link-local or
 	 * site-local are okay
 	 */
 	if (!(IN6_IS_ADDR_LINKLOCAL(saddr) ||
 	      IN6_IS_ADDR_SITELOCAL(saddr) ||
 	      IN6_IS_ADDR_LOOPBACK(saddr)))
 		return 0;
 	return 1;
 }

 /* ---------- */
 void init_core(int forced)
 {
 	int i;

 	DEBUG(LOG_DEBUG, "%s()\n", __func__);

 	if (!initialized || forced) {
 		struct timeval tv;
 		unsigned int seed = 0;
 		pid_t pid;

 		if (gettimeofday(&tv, NULL) < 0) {
 			DEBUG(LOG_WARNING, "%s(): failed to gettimeofday()\n", __func__);
 		} else {
 			seed = (tv.tv_usec & 0xffffffff);
 		}

 		pid = getpid();
 		seed ^= (((unsigned long)pid) & 0xffffffff);

 		srand(seed);

 #if ENABLE_THREADS && HAVE_LIBPTHREAD
 		if (initialized)
 			pthread_attr_destroy(&pattr);

 		pthread_attr_init(&pattr);
 		pthread_attr_setdetachstate(&pattr, PTHREAD_CREATE_DETACHED);
 #endif
 	}

 	for (i=0; i < ARRAY_SIZE(subjinfo_table); i++) {
 		if (subjinfo_table[i].name == NULL)
 			continue;
 		if (subjinfo_table[i].init)
 			subjinfo_table[i].init(forced);
 	}

 	for (i=0; i < ARRAY_SIZE(qtypeinfo_table); i++) {
 		if (qtypeinfo_table[i].name == NULL)
 			continue;
 		if (qtypeinfo_table[i].init)
 			qtypeinfo_table[i].init(forced);
 	}

 	initialized = 1;

 	return;
 }

 #if ENABLE_THREADS && HAVE_LIBPTHREAD
 static void *ni_send_thread(void *data)
 {
 	int ret;
 	DEBUG(LOG_DEBUG, "%s(): thread=%ld\n", __func__, pthread_self());
 	ret = ni_send(data);
 	DEBUG(LOG_DEBUG, "%s(): thread=%ld => %d\n", __func__, pthread_self(), ret);
 	return NULL;
 }
 #else
 static int ni_send_fork(struct packetcontext *p)
 {
 	pid_t child = fork();
 	if (child < 0)
 		return -1;
 	if (child == 0) {
 		pid_t grandchild = fork();
 		if (grandchild < 0)
 			exit(1);
 		if (grandchild == 0) {
 			int ret;
 			DEBUG(LOG_DEBUG, "%s(): worker=%d\n",
 			      __func__, getpid());
 			ret = ni_send(p);
 			DEBUG(LOG_DEBUG, "%s(): worker=%d => %d\n",
 			      __func__, getpid(), ret);
 			exit(ret > 0 ? 1 : 0);
 		}
 		ni_free(p->replydata);
 		ni_free(p);
 		exit(0);
 	} else {
 		waitpid(child, NULL, 0);
 		ni_free(p->replydata);
 		ni_free(p);
 	}
 	return 0;
 }
 #endif

 static int ni_ratelimit(void)
 {
 	static struct timeval last;
 	struct timeval tv, sub;

 	if (gettimeofday(&tv, NULL) < 0) {
 		DEBUG(LOG_WARNING, "%s(): gettimeofday(): %s\n",
 		      __func__, strerror(errno));
 		return -1;
 	}

 	if (!timerisset(&last)) {
 		last = tv;
 		return 0;
 	}

 	timersub(&tv, &last, &sub);

 	if (sub.tv_sec < 1)
 		return 1;

 	last = tv;
 	return 0;
 }

 int pr_nodeinfo(struct packetcontext *p)
 {
 	struct icmp6_nodeinfo *query = (struct icmp6_nodeinfo *)p->query;

 	char *subject = (char *)(query + 1);
 	size_t subjlen;
 	struct subjinfo *subjinfo;
 	struct qtypeinfo *qtypeinfo;
 	int replyonsubjcheck = 0;
 	unsigned int subj_if;
 #if ENABLE_DEBUG
 	char printbuf[128];
 	int i;
 	char *cp;
 #endif
 #if ENABLE_THREADS && HAVE_PTHREAD_H
 	pthread_t thread;
 #endif
 	int rc;

 	/* Step 0: Check destination address
 	 *		discard non-linklocal multicast
 	 *		discard non-nigroup multicast address(?)
 	 */
 	if (IN6_IS_ADDR_MULTICAST(&p->pktinfo.ipi6_addr)) {
 		if (!IN6_IS_ADDR_MC_LINKLOCAL(&p->pktinfo.ipi6_addr)) {
 			DEBUG(LOG_WARNING,
 			      "Destination is non-link-local multicast address.\n");
 			ni_free(p);
 			return -1;
 		}
 #if 0
 		/* Do not discard NI Queries to multicast address
 		 * other than its own NI Group Address(es) by default.
 		 */
 		if (!check_nigroup(&p->pktinfo.ipi6_addr)) {
 			DEBUG(LOG_WARNING,
 			      "Destination is link-local multicast address other than "
 			      "NI Group address.\n");
 			ni_free(p);
 			return -1;
 		}
 #endif
 	}

 	/* Step 1: Check length */
 	if (p->querylen < sizeof(struct icmp6_nodeinfo)) {
 		DEBUG(LOG_WARNING, "Query too short\n");
 		ni_free(p);
 		return -1;
 	}

 #if ENABLE_DEBUG
 	cp = printbuf;
 	for (i = 0; i < sizeof(query->icmp6_ni_nonce); i++) {
 		cp += sprintf(cp, " %02x", query->icmp6_ni_nonce[i]);
 	}
 	DEBUG(LOG_DEBUG, "%s(): qtype=%d, flags=0x%04x, nonce[] = {%s }\n",
 	      __func__,
 	      ntohs(query->ni_qtype), ntohs(query->ni_flags), printbuf);
 #endif

 	subjlen = p->querylen - sizeof(struct icmp6_nodeinfo);

 	/* Step 2: Check Subject Code */
 	switch(htons(query->ni_qtype)) {
 	case NI_QTYPE_NOOP:
 	case NI_QTYPE_SUPTYPES:
 		if (query->ni_code != ICMP6_NI_SUBJ_FQDN) {
 			DEBUG(LOG_WARNING,
 			      "%s(): invalid/unknown code %u\n",
 			      __func__, query->ni_code);
 			subjlen = 0;
 		}
 		subjinfo = &subjinfo_null;
 		break;
 	default:
 		subjinfo = subjinfo_lookup(query->ni_code);
 		if (!subjinfo) {
 			DEBUG(LOG_WARNING,
 			      "%s(): unknown code %u\n",
 			      __func__, query->ni_code);
 			ni_free(p);
 			return -1;
 		}
 	}

 	/* Step 3: Lookup Qtype */
 	qtypeinfo = qtypeinfo_lookup(ntohs(query->ni_qtype));

 	/* Step 4: Check Subject
 	 *         (And fill reply if it is available now)
 	 */
 	if (qtypeinfo->getreply == subjinfo->checksubj)
 		replyonsubjcheck = 1;

 	if (subjinfo->checksubj(p,
 				subject, subjlen,
 				query->ni_flags,
 				replyonsubjcheck ? NULL : &subj_if,
 				replyonsubjcheck)) {
 		if (p->replydatalen < 0) {
 			DEBUG(LOG_WARNING,
 			      "failed to make reply: %s\n",
 			      strerror(errno));
 		}
 		ni_free(p);
 		return -1;
 	}

 	/* XXX: Step 5: Check the policy */
 	rc = ni_policy(p);
 	if (rc <= 0) {
 		ni_free(p->replydata);
 		p->replydata = NULL;
 		p->replydatalen = 0;
 		if (rc < 0) {
 			DEBUG(LOG_WARNING, "Ignored by policy.\n");
 			ni_free(p);
 			return -1;
 		}
 		DEBUG(LOG_WARNING, "Refused by policy.\n");
 		replyonsubjcheck = 0;
 		qtypeinfo = &qtypeinfo_refused;
 	}

 	/* Step 6: Fill the reply if not yet done */
 	if (!replyonsubjcheck) {
 		if (qtypeinfo->getreply(p,
 					NULL, 0,
 					query->ni_flags,
 					&subj_if,
 					1)) {
 			if (p->replydatalen) {
 				DEBUG(LOG_WARNING,
 				      "failed to make reply: %s\n",
 				      strerror(errno));
 			}
 			ni_free(p);
 			return -1;
 		}
 	}

 	/* Step 7: Rate Limit */
 	if (qtypeinfo->flags&QTYPEINFO_F_RATELIMIT &&
 	    ni_ratelimit()) {
 		ni_free(p->replydata);
 		ni_free(p);
 		return -1;
 	}

 	/* Step 8: Fill Qtype / Nonce */
 	p->reply.ni_qtype = query->ni_qtype;
 	memcpy(p->reply.icmp6_ni_nonce, query->icmp6_ni_nonce, sizeof(p->reply.icmp6_ni_nonce));

 	/* Step 9: Source address selection */
 	if (IN6_IS_ADDR_MULTICAST(&p->pktinfo.ipi6_addr)) {
 		/* if query was sent to multicast address,
 		 * use source address selection in kernel.
 		 * XXX: anycast?
 		 */
 		memset(&p->pktinfo.ipi6_addr, 0, sizeof(p->pktinfo.ipi6_addr));

 	 	/* Random Delay between zero and MAX_ANYCAST_DELAY_TIME is
 		 * required if query was sent to anycast or multicast address.
 		 */
 		p->delay = (int) (MAX_ANYCAST_DELAY_TIME*rand()/(RAND_MAX+1.0));
 	} else {
 		p->delay = 0;
 	}

 	/* Step 10: Send the reply
 	 * XXX: with possible random delay */
 #if ENABLE_THREADS && HAVE_LIBPTHREAD
 	/* ni_send_thread() frees p */
 	if (pthread_create(&thread, &pattr, ni_send_thread, p)) {
 		ni_free(p->replydata);
 		ni_free(p);
 		return -1;
 	}
 #else
 	/* ni_send_fork() frees p */
 	if (ni_send_fork(p)) {
 		ni_free(p->replydata);
 		ni_free(p);
 		return -1;
 	}
 #endif

 	return 0;
 }
	/* $USAGI: ninfod_core.c,v 1.29 2003-07-16 09:49:01 yoshfuji Exp $ */
	/*
	* Copyright (C) 2002 USAGI/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.
	*/
	/*
	* Author:
	* YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
	*/

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

	#if HAVE_SYS_TYPES_H
	# include <sys/types.h>
	#endif
	#if STDC_HEADERS
	# include <stdio.h>
	# include <stdlib.h>
	# include <stddef.h>
	#else
	# if HAVE_STDLIB_H
	# include <stdlib.h>
	# endif
	#endif
	#if ENABLE_THREADS && HAVE_PTHREAD_H
	# include <pthread.h>
	#endif
	#if HAVE_STRING_H
	# if !STDC_HEADERS && HAVE_MEMORY_H
	# include <memory.h>
	# endif
	# include <string.h>
	#endif
	#if HAVE_STRINGS_H
	# include <strings.h>
	#endif
	#if HAVE_INTTYPES_H
	# include <inttypes.h>
	#else
	# if HAVE_STDINT_H
	# include <stdint.h>
	# endif
	#endif
	#if HAVE_UNISTD_H
	# include <unistd.h>
	#endif

	#if TIME_WITH_SYS_TIME
	# include <sys/time.h>
	# include <time.h>
	#else
	# if HAVE_SYS_TIME_H
	# include <sys/time.h>
	# else
	# include <time.h>
	# endif
	#endif

	#if HAVE_SYS_UIO_H
	#include <sys/uio.h>
	#endif

	#if HAVE_NETINET_IN_H
	# include <netinet/in.h>
	#endif

	#if HAVE_NETINET_ICMP6_H
	# include <netinet/icmp6.h>
	#endif
	#ifndef HAVE_STRUCT_ICMP6_NODEINFO
	# include "icmp6_nodeinfo.h"
	#endif

	#if HAVE_NETDB_H
	# include <netdb.h>
	#endif
	#include <errno.h>

	#if HAVE_SYSLOG_H
	# include <syslog.h>
	#endif

	#include "ninfod.h"

	#ifndef offsetof
	# define offsetof(aggregate,member) ((size_t)&((aggregate *)0)->member)
	#endif

	#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))

	/* ---------- */
	/* ID */
	static char *RCSID __attribute__ ((unused)) = "$USAGI: ninfod_core.c,v 1.29 2003-07-16 09:49:01 yoshfuji Exp $";

	/* Variables */
	int initialized = 0;

	#if ENABLE_THREADS && HAVE_LIBPTHREAD
	pthread_attr_t pattr;
	#endif

	static uint32_t suptypes[(MAX_SUPTYPES+31)>>5];
	static size_t suptypes_len;

	/* ---------- */
	struct subjinfo {
	uint8_t code;
	char *name;
	int (*checksubj)(CHECKANDFILL_ARGS);
	int (*init)(INIT_ARGS);
	};

	static struct subjinfo subjinfo_table [] = {
	[ICMP6_NI_SUBJ_IPV6] = {
	.code = ICMP6_NI_SUBJ_IPV6,
	.name = "IPv6",
	//.init = init_nodeinfo_ipv6addr,
	.checksubj = pr_nodeinfo_ipv6addr,
	},
	[ICMP6_NI_SUBJ_FQDN] = {
	.code = ICMP6_NI_SUBJ_FQDN,
	.name = "FQDN",
	//.init = init_nodeinfo_nodename,
	.checksubj = pr_nodeinfo_nodename,
	},
	[ICMP6_NI_SUBJ_IPV4] = {
	.code = ICMP6_NI_SUBJ_IPV4,
	.name = "IPv4",
	//.init = init_nodeinfo_ipv4addr,
	.checksubj = pr_nodeinfo_ipv4addr,
	},
	};

	static struct subjinfo subjinfo_null = {
	.name = "null",
	.checksubj = pr_nodeinfo_noop,
	};

	static __inline__ struct subjinfo *subjinfo_lookup(int code)
	{
	if (code >= ARRAY_SIZE(subjinfo_table))
	return NULL;
	if (subjinfo_table[code].name == NULL)
	return NULL;
	return &subjinfo_table[code];
	}

	/* ---------- */
	#define QTYPEINFO_F_RATELIMIT 0x1

	struct qtypeinfo {
	uint16_t qtype;
	char *name;
	int (*getreply)(CHECKANDFILL_ARGS);
	void (*init)(INIT_ARGS);
	int flags;
	};

	static struct qtypeinfo qtypeinfo_table[] = {
	[NI_QTYPE_NOOP] = {
	.qtype = NI_QTYPE_NOOP,
	.name = "NOOP",
	.getreply = pr_nodeinfo_noop,
	},
	#if ENABLE_SUPTYPES
	[NI_QTYPE_SUPTYPES] = {
	.qtype = NI_QTYPE_SUPTYPES,
	.name = "SupTypes",
	.getreply = pr_nodeinfo_suptypes,
	.init = init_nodeinfo_suptypes,
	},
	#endif
	[NI_QTYPE_DNSNAME] = {
	.qtype = NI_QTYPE_DNSNAME,
	.name = "DnsName",
	.getreply = pr_nodeinfo_nodename,
	.init = init_nodeinfo_nodename,
	},
	[NI_QTYPE_NODEADDR] = {
	.qtype = NI_QTYPE_NODEADDR,
	.name = "NodeAddr",
	.getreply = pr_nodeinfo_ipv6addr,
	.init = init_nodeinfo_ipv6addr,
	},
	[NI_QTYPE_IPV4ADDR] = {
	.qtype = NI_QTYPE_IPV4ADDR,
	.name = "IPv4Addr",
	.getreply = pr_nodeinfo_ipv4addr,
	.init = init_nodeinfo_ipv4addr,
	},
	};

	static struct qtypeinfo qtypeinfo_unknown = {
	.name = "unknown",
	.getreply = pr_nodeinfo_unknown,
	.flags = QTYPEINFO_F_RATELIMIT,
	};

	static struct qtypeinfo qtypeinfo_refused = {
	.name = "refused",
	.getreply = pr_nodeinfo_refused,
	.flags = QTYPEINFO_F_RATELIMIT,
	};

	static __inline__ struct qtypeinfo *qtypeinfo_lookup(int qtype)
	{
	if (qtype >= ARRAY_SIZE(qtypeinfo_table))
	return &qtypeinfo_unknown;
	if (qtypeinfo_table[qtype].name == NULL)
	return &qtypeinfo_unknown;
	return &qtypeinfo_table[qtype];
	}

	/* ---------- */
	/* noop */
	int pr_nodeinfo_noop(CHECKANDFILL_ARGS)
	{
	DEBUG(LOG_DEBUG, "%s()\n", __func__);

	if (subjlen) {
	DEBUG(LOG_WARNING,
	"%s(): invalid subject length(%zu)\n",
	__func__, subjlen);
	return 1;
	}

	if (reply) {
	p->reply.ni_type = ICMP6_NI_REPLY;
	p->reply.ni_code = ICMP6_NI_SUCCESS;
	p->reply.ni_cksum = 0;
	p->reply.ni_qtype = htons(NI_QTYPE_NOOP);
	p->reply.ni_flags = flags;
	}

	if (subj_if)
	*subj_if = 0;

	return 0;
	}

	#if ENABLE_SUPTYPES
	/* suptypes */
	int pr_nodeinfo_suptypes(CHECKANDFILL_ARGS)
	{
	DEBUG(LOG_DEBUG, "%s()\n", __func__);

	if (subjlen) {
	DEBUG(LOG_WARNING, "%s(): invalid subject length(%zu)\n",
	__func__, subjlen);
	return 1;
	}

	if (reply) {
	p->reply.ni_type = ICMP6_NI_REPLY;
	p->reply.ni_code = ICMP6_NI_SUCCESS;
	p->reply.ni_cksum = 0;
	p->reply.ni_qtype = htons(NI_QTYPE_SUPTYPES);
	p->reply.ni_flags = flags&~NI_SUPTYPE_FLAG_COMPRESS;

	p->replydatalen = suptypes_len<<2;
	p->replydata = ni_malloc(p->replydatalen);
	if (p->replydata == NULL) {
	p->replydatalen = -1;
	return -1; /XXX/
	}

	memcpy(p->replydata, suptypes, p->replydatalen);
	}
	return 0;
	}

	void init_nodeinfo_suptypes(INIT_ARGS)
	{
	size_t w, b;
	int i;

	if (!forced && initialized)
	return;

	memset(suptypes, 0, sizeof(suptypes));
	suptypes_len = 0;

	for (i=0; i < ARRAY_SIZE(qtypeinfo_table); i++) {
	unsigned short qtype;

	if (qtypeinfo_table[i].name == NULL)
	continue;
	qtype = qtypeinfo_table[i].qtype;
	w = qtype>>5;
	b = qtype&0x1f;
	if (w >= ARRAY_SIZE(suptypes)) {
	/* This is programming error. */
	DEBUG(LOG_ERR, "Warning: Too Large Supported Types\n");
	exit(1);
	}
	suptypes[w] \|= htonl(1<<b);

	if (suptypes_len < w)
	suptypes_len = w;
	}
	suptypes_len++;
	}
	#endif

	/* ---------- */
	/* unknown qtype response */
	int pr_nodeinfo_unknown(CHECKANDFILL_ARGS)
	{
	if (!reply)
	return -1; /???/

	p->reply.ni_type = ICMP6_NI_REPLY;
	p->reply.ni_code = ICMP6_NI_UNKNOWN;
	p->reply.ni_cksum = 0;
	//p->reply.ni_qtype = 0;
	p->reply.ni_flags = flags;

	p->replydata = NULL;
	p->replydatalen = 0;

	return 0;
	}

	/* refused response */
	int pr_nodeinfo_refused(CHECKANDFILL_ARGS)
	{
	if (!reply)
	return -1; /???/

	p->reply.ni_type = ICMP6_NI_REPLY;
	p->reply.ni_code = ICMP6_NI_REFUSED;
	p->reply.ni_cksum = 0;
	//p->reply.ni_qtype = 0;
	p->reply.ni_flags = flags;

	p->replydata = NULL;
	p->replydatalen = 0;

	return 0;
	}

	/* ---------- */
	/* Policy */
	static int ni_policy(struct packetcontext *p)
	{
	const struct in6_addr saddr = &((const struct sockaddr_in6 )&p->addr)->sin6_addr;

	/*
	* >0: reply
	* 0: refused
	* <0: discard
	*/

	/* Default policy is to refuse queries from
	* non-local addresses; loopback, link-local or
	* site-local are okay
	*/
	if (!(IN6_IS_ADDR_LINKLOCAL(saddr) \|\|
	IN6_IS_ADDR_SITELOCAL(saddr) \|\|
	IN6_IS_ADDR_LOOPBACK(saddr)))
	return 0;
	return 1;
	}

	/* ---------- */
	void init_core(int forced)
	{
	int i;

	DEBUG(LOG_DEBUG, "%s()\n", __func__);

	if (!initialized \|\| forced) {
	struct timeval tv;
	unsigned int seed = 0;
	pid_t pid;

	if (gettimeofday(&tv, NULL) < 0) {
	DEBUG(LOG_WARNING, "%s(): failed to gettimeofday()\n", __func__);
	} else {
	seed = (tv.tv_usec & 0xffffffff);
	}

	pid = getpid();
	seed ^= (((unsigned long)pid) & 0xffffffff);

	srand(seed);

	#if ENABLE_THREADS && HAVE_LIBPTHREAD
	if (initialized)
	pthread_attr_destroy(&pattr);

	pthread_attr_init(&pattr);
	pthread_attr_setdetachstate(&pattr, PTHREAD_CREATE_DETACHED);
	#endif
	}

	for (i=0; i < ARRAY_SIZE(subjinfo_table); i++) {
	if (subjinfo_table[i].name == NULL)
	continue;
	if (subjinfo_table[i].init)
	subjinfo_table[i].init(forced);
	}

	for (i=0; i < ARRAY_SIZE(qtypeinfo_table); i++) {
	if (qtypeinfo_table[i].name == NULL)
	continue;
	if (qtypeinfo_table[i].init)
	qtypeinfo_table[i].init(forced);
	}

	initialized = 1;

	return;
	}

	#if ENABLE_THREADS && HAVE_LIBPTHREAD
	static void ni_send_thread(void data)
	{
	int ret;
	DEBUG(LOG_DEBUG, "%s(): thread=%ld\n", __func__, pthread_self());
	ret = ni_send(data);
	DEBUG(LOG_DEBUG, "%s(): thread=%ld => %d\n", __func__, pthread_self(), ret);
	return NULL;
	}
	#else
	static int ni_send_fork(struct packetcontext *p)
	{
	pid_t child = fork();
	if (child < 0)
	return -1;
	if (child == 0) {
	pid_t grandchild = fork();
	if (grandchild < 0)
	exit(1);
	if (grandchild == 0) {
	int ret;
	DEBUG(LOG_DEBUG, "%s(): worker=%d\n",
	__func__, getpid());
	ret = ni_send(p);
	DEBUG(LOG_DEBUG, "%s(): worker=%d => %d\n",
	__func__, getpid(), ret);
	exit(ret > 0 ? 1 : 0);
	}
	ni_free(p->replydata);
	ni_free(p);
	exit(0);
	} else {
	waitpid(child, NULL, 0);
	ni_free(p->replydata);
	ni_free(p);
	}
	return 0;
	}
	#endif

	static int ni_ratelimit(void)
	{
	static struct timeval last;
	struct timeval tv, sub;

	if (gettimeofday(&tv, NULL) < 0) {
	DEBUG(LOG_WARNING, "%s(): gettimeofday(): %s\n",
	__func__, strerror(errno));
	return -1;
	}

	if (!timerisset(&last)) {
	last = tv;
	return 0;
	}

	timersub(&tv, &last, &sub);

	if (sub.tv_sec < 1)
	return 1;

	last = tv;
	return 0;
	}

	int pr_nodeinfo(struct packetcontext *p)
	{
	struct icmp6_nodeinfo query = (struct icmp6_nodeinfo )p->query;

	char subject = (char )(query + 1);
	size_t subjlen;
	struct subjinfo *subjinfo;
	struct qtypeinfo *qtypeinfo;
	int replyonsubjcheck = 0;
	unsigned int subj_if;
	#if ENABLE_DEBUG
	char printbuf[128];
	int i;
	char *cp;
	#endif
	#if ENABLE_THREADS && HAVE_PTHREAD_H
	pthread_t thread;
	#endif
	int rc;

	/* Step 0: Check destination address
	* discard non-linklocal multicast
	* discard non-nigroup multicast address(?)
	*/
	if (IN6_IS_ADDR_MULTICAST(&p->pktinfo.ipi6_addr)) {
	if (!IN6_IS_ADDR_MC_LINKLOCAL(&p->pktinfo.ipi6_addr)) {
	DEBUG(LOG_WARNING,
	"Destination is non-link-local multicast address.\n");
	ni_free(p);
	return -1;
	}
	#if 0
	/* Do not discard NI Queries to multicast address
	* other than its own NI Group Address(es) by default.
	*/
	if (!check_nigroup(&p->pktinfo.ipi6_addr)) {
	DEBUG(LOG_WARNING,
	"Destination is link-local multicast address other than "
	"NI Group address.\n");
	ni_free(p);
	return -1;
	}
	#endif
	}

	/* Step 1: Check length */
	if (p->querylen < sizeof(struct icmp6_nodeinfo)) {
	DEBUG(LOG_WARNING, "Query too short\n");
	ni_free(p);
	return -1;
	}

	#if ENABLE_DEBUG
	cp = printbuf;
	for (i = 0; i < sizeof(query->icmp6_ni_nonce); i++) {
	cp += sprintf(cp, " %02x", query->icmp6_ni_nonce[i]);
	}
	DEBUG(LOG_DEBUG, "%s(): qtype=%d, flags=0x%04x, nonce[] = {%s }\n",
	__func__,
	ntohs(query->ni_qtype), ntohs(query->ni_flags), printbuf);
	#endif

	subjlen = p->querylen - sizeof(struct icmp6_nodeinfo);

	/* Step 2: Check Subject Code */
	switch(htons(query->ni_qtype)) {
	case NI_QTYPE_NOOP:
	case NI_QTYPE_SUPTYPES:
	if (query->ni_code != ICMP6_NI_SUBJ_FQDN) {
	DEBUG(LOG_WARNING,
	"%s(): invalid/unknown code %u\n",
	__func__, query->ni_code);
	subjlen = 0;
	}
	subjinfo = &subjinfo_null;
	break;
	default:
	subjinfo = subjinfo_lookup(query->ni_code);
	if (!subjinfo) {
	DEBUG(LOG_WARNING,
	"%s(): unknown code %u\n",
	__func__, query->ni_code);
	ni_free(p);
	return -1;
	}
	}

	/* Step 3: Lookup Qtype */
	qtypeinfo = qtypeinfo_lookup(ntohs(query->ni_qtype));

	/* Step 4: Check Subject
	* (And fill reply if it is available now)
	*/
	if (qtypeinfo->getreply == subjinfo->checksubj)
	replyonsubjcheck = 1;

	if (subjinfo->checksubj(p,
	subject, subjlen,
	query->ni_flags,
	replyonsubjcheck ? NULL : &subj_if,
	replyonsubjcheck)) {
	if (p->replydatalen < 0) {
	DEBUG(LOG_WARNING,
	"failed to make reply: %s\n",
	strerror(errno));
	}
	ni_free(p);
	return -1;
	}

	/* XXX: Step 5: Check the policy */
	rc = ni_policy(p);
	if (rc <= 0) {
	ni_free(p->replydata);
	p->replydata = NULL;
	p->replydatalen = 0;
	if (rc < 0) {
	DEBUG(LOG_WARNING, "Ignored by policy.\n");
	ni_free(p);
	return -1;
	}
	DEBUG(LOG_WARNING, "Refused by policy.\n");
	replyonsubjcheck = 0;
	qtypeinfo = &qtypeinfo_refused;
	}

	/* Step 6: Fill the reply if not yet done */
	if (!replyonsubjcheck) {
	if (qtypeinfo->getreply(p,
	NULL, 0,
	query->ni_flags,
	&subj_if,
	1)) {
	if (p->replydatalen) {
	DEBUG(LOG_WARNING,
	"failed to make reply: %s\n",
	strerror(errno));
	}
	ni_free(p);
	return -1;
	}
	}

	/* Step 7: Rate Limit */
	if (qtypeinfo->flags&QTYPEINFO_F_RATELIMIT &&
	ni_ratelimit()) {
	ni_free(p->replydata);
	ni_free(p);
	return -1;
	}

	/* Step 8: Fill Qtype / Nonce */
	p->reply.ni_qtype = query->ni_qtype;
	memcpy(p->reply.icmp6_ni_nonce, query->icmp6_ni_nonce, sizeof(p->reply.icmp6_ni_nonce));

	/* Step 9: Source address selection */
	if (IN6_IS_ADDR_MULTICAST(&p->pktinfo.ipi6_addr)) {
	/* if query was sent to multicast address,
	* use source address selection in kernel.
	* XXX: anycast?
	*/
	memset(&p->pktinfo.ipi6_addr, 0, sizeof(p->pktinfo.ipi6_addr));

	/* Random Delay between zero and MAX_ANYCAST_DELAY_TIME is
	* required if query was sent to anycast or multicast address.
	*/
	p->delay = (int) (MAX_ANYCAST_DELAY_TIME*rand()/(RAND_MAX+1.0));
	} else {
	p->delay = 0;
	}

	/* Step 10: Send the reply
	* XXX: with possible random delay */
	#if ENABLE_THREADS && HAVE_LIBPTHREAD
	/* ni_send_thread() frees p */
	if (pthread_create(&thread, &pattr, ni_send_thread, p)) {
	ni_free(p->replydata);
	ni_free(p);
	return -1;
	}
	#else
	/* ni_send_fork() frees p */
	if (ni_send_fork(p)) {
	ni_free(p->replydata);
	ni_free(p);
	return -1;
	}
	#endif

	return 0;
	}