interfacemgr.c

非常好的dns解析软件

	return (ISC_R_SUCCESS);
}

static isc_boolean_t
listenon_is_ip6_any(ns_listenelt_t *elt) {
	if (elt->acl->length != 1)
		return (ISC_FALSE);
	if (elt->acl->elements[0].negative == ISC_FALSE &&
	    elt->acl->elements[0].type == dns_aclelementtype_any)
		return (ISC_TRUE);  /* listen-on-v6 { any; } */
	return (ISC_FALSE); /* All others */
}

static isc_result_t
setup_locals(ns_interfacemgr_t *mgr, isc_interface_t *interface) {
	isc_result_t result;
	dns_aclelement_t elt;
	unsigned int family;
	unsigned int prefixlen;

	family = interface->address.family;
	
	elt.type = dns_aclelementtype_ipprefix;
	elt.negative = ISC_FALSE;
	elt.u.ip_prefix.address = interface->address;
	elt.u.ip_prefix.prefixlen = (family == AF_INET) ? 32 : 128;
	result = dns_acl_appendelement(mgr->aclenv.localhost, &elt);
	if (result != ISC_R_SUCCESS)
		return (result);

	result = isc_netaddr_masktoprefixlen(&interface->netmask,
					     &prefixlen);

	/* Non contigious netmasks not allowed by IPv6 arch. */
	if (result != ISC_R_SUCCESS && family == AF_INET6)
		return (result);

	if (result != ISC_R_SUCCESS) {
		isc_log_write(IFMGR_COMMON_LOGARGS,
			      ISC_LOG_WARNING,
			      "omitting IPv4 interface %s from "
			      "localnets ACL: %s",
			      interface->name,
			      isc_result_totext(result));
	} else {
		elt.u.ip_prefix.prefixlen = prefixlen;
		if (dns_acl_elementmatch(mgr->aclenv.localnets, &elt,
					 NULL) == ISC_R_NOTFOUND) {
			result = dns_acl_appendelement(mgr->aclenv.localnets,
						       &elt);
			if (result != ISC_R_SUCCESS)
				return (result);
		}
	}

	return (ISC_R_SUCCESS);
}

static void
setup_listenon(ns_interfacemgr_t *mgr, isc_interface_t *interface,
	       in_port_t port)
{ 
	isc_sockaddr_t *addr;
	isc_sockaddr_t *old;

	addr = isc_mem_get(mgr->mctx, sizeof(*addr));
	if (addr == NULL)
		return;

	isc_sockaddr_fromnetaddr(addr, &interface->address, port);

	for (old = ISC_LIST_HEAD(mgr->listenon);
	     old != NULL;
	     old = ISC_LIST_NEXT(old, link))
		if (isc_sockaddr_equal(addr, old))
			break;	

	if (old != NULL)
		isc_mem_put(mgr->mctx, addr, sizeof(*addr));
	else
		ISC_LIST_APPEND(mgr->listenon, addr, link);
}

static void
clearlistenon(ns_interfacemgr_t *mgr) {
	isc_sockaddr_t *old;

	old = ISC_LIST_HEAD(mgr->listenon);
	while (old != NULL) {
		ISC_LIST_UNLINK(mgr->listenon, old, link);
		isc_mem_put(mgr->mctx, old, sizeof(*old));
		old = ISC_LIST_HEAD(mgr->listenon);
	}
}

static isc_result_t
do_scan(ns_interfacemgr_t *mgr, ns_listenlist_t *ext_listen,
	isc_boolean_t verbose)
{
	isc_interfaceiter_t *iter = NULL;
	isc_boolean_t scan_ipv4 = ISC_FALSE;
	isc_boolean_t scan_ipv6 = ISC_FALSE;
	isc_boolean_t adjusting = ISC_FALSE;
	isc_boolean_t ipv6only = ISC_TRUE;
	isc_boolean_t ipv6pktinfo = ISC_TRUE;
	isc_result_t result;
	isc_netaddr_t zero_address, zero_address6;
	ns_listenelt_t *le;
	isc_sockaddr_t listen_addr;
	ns_interface_t *ifp;
	isc_boolean_t log_explicit = ISC_FALSE;
	isc_boolean_t dolistenon;

	if (ext_listen != NULL)
		adjusting = ISC_TRUE;

	if (isc_net_probeipv6() == ISC_R_SUCCESS)
		scan_ipv6 = ISC_TRUE;
#ifdef WANT_IPV6
	else
		isc_log_write(IFMGR_COMMON_LOGARGS,
			      verbose ? ISC_LOG_INFO : ISC_LOG_DEBUG(1),
			      "no IPv6 interfaces found");
#endif

	if (isc_net_probeipv4() == ISC_R_SUCCESS)
		scan_ipv4 = ISC_TRUE;
	else
		isc_log_write(IFMGR_COMMON_LOGARGS,
			      verbose ? ISC_LOG_INFO : ISC_LOG_DEBUG(1),
			      "no IPv4 interfaces found");

	/*
	 * A special, but typical case; listen-on-v6 { any; }.
	 * When we can make the socket IPv6-only, open a single wildcard
	 * socket for IPv6 communication.  Otherwise, make separate socket
	 * for each IPv6 address in order to avoid accepting IPv4 packets
	 * as the form of mapped addresses unintentionally unless explicitly
	 * allowed.
	 */
#ifndef ISC_ALLOW_MAPPED
	if (scan_ipv6 == ISC_TRUE &&
	    isc_net_probe_ipv6only() != ISC_R_SUCCESS) {
		ipv6only = ISC_FALSE;
		log_explicit = ISC_TRUE;
	}
#endif
	if (scan_ipv6 == ISC_TRUE &&
	    isc_net_probe_ipv6pktinfo() != ISC_R_SUCCESS) {
		ipv6pktinfo = ISC_FALSE;
		log_explicit = ISC_TRUE;
	}
	if (scan_ipv6 == ISC_TRUE && ipv6only && ipv6pktinfo) {
		for (le = ISC_LIST_HEAD(mgr->listenon6->elts);
		     le != NULL;
		     le = ISC_LIST_NEXT(le, link)) {
			struct in6_addr in6a;

			if (!listenon_is_ip6_any(le))
				continue;

			in6a = in6addr_any;
			isc_sockaddr_fromin6(&listen_addr, &in6a, le->port);

			ifp = find_matching_interface(mgr, &listen_addr);
			if (ifp != NULL) {
				ifp->generation = mgr->generation;
			} else {
				isc_log_write(IFMGR_COMMON_LOGARGS,
					      ISC_LOG_INFO,
					      "listening on IPv6 "
					      "interfaces, port %u",
					      le->port);
				result = ns_interface_setup(mgr, &listen_addr,
							    "<any>", &ifp,
							    ISC_TRUE);
				if (result == ISC_R_SUCCESS)
					ifp->flags |= NS_INTERFACEFLAG_ANYADDR;
				else
					isc_log_write(IFMGR_COMMON_LOGARGS,
						      ISC_LOG_ERROR,
						      "listening on all IPv6 "
						      "interfaces failed");
				/* Continue. */
			}
		}
	}

	isc_netaddr_any(&zero_address);
	isc_netaddr_any6(&zero_address6);

	result = isc_interfaceiter_create(mgr->mctx, &iter);
	if (result != ISC_R_SUCCESS)
		return (result);

	if (adjusting == ISC_FALSE) {
		result = clearacl(mgr->mctx, &mgr->aclenv.localhost);
		if (result != ISC_R_SUCCESS)
			goto cleanup_iter;
		result = clearacl(mgr->mctx, &mgr->aclenv.localnets);
		if (result != ISC_R_SUCCESS)
			goto cleanup_iter;
		clearlistenon(mgr);
	}

	for (result = isc_interfaceiter_first(iter);
	     result == ISC_R_SUCCESS;
	     result = isc_interfaceiter_next(iter))
	{
		isc_interface_t interface;
		ns_listenlist_t *ll;
		unsigned int family; 

		result = isc_interfaceiter_current(iter, &interface);
		if (result != ISC_R_SUCCESS)
			break;

		family = interface.address.family;
		if (family != AF_INET && family != AF_INET6)
			continue;
		if (scan_ipv4 == ISC_FALSE && family == AF_INET)
			continue;
		if (scan_ipv6 == ISC_FALSE && family == AF_INET6)
			continue;

		/*
		 * Test for the address being nonzero rather than testing
		 * INTERFACE_F_UP, because on some systems the latter
		 * follows the media state and we could end up ignoring
		 * the interface for an entire rescan interval due to
		 * a temporary media glitch at rescan time.
		 */
		if (family == AF_INET &&
		    isc_netaddr_equal(&interface.address, &zero_address)) {
			continue;
		}
		if (family == AF_INET6 &&
		    isc_netaddr_equal(&interface.address, &zero_address6)) {
			continue;
		}

		if (adjusting == ISC_FALSE) {
			result = setup_locals(mgr, &interface);
			if (result != ISC_R_SUCCESS)
				goto ignore_interface;
		}

		ll = (family == AF_INET) ? mgr->listenon4 : mgr->listenon6;
		dolistenon = ISC_TRUE;
		for (le = ISC_LIST_HEAD(ll->elts);
		     le != NULL;
		     le = ISC_LIST_NEXT(le, link))
		{
			int match;
			isc_boolean_t ipv6_wildcard = ISC_FALSE;
			isc_netaddr_t listen_netaddr;
			isc_sockaddr_t listen_sockaddr;

			/*
			 * Construct a socket address for this IP/port
			 * combination.
			 */
			if (family == AF_INET) {
				isc_netaddr_fromin(&listen_netaddr,
						   &interface.address.type.in);
			} else {
				isc_netaddr_fromin6(&listen_netaddr,
						    &interface.address.type.in6);
				isc_netaddr_setzone(&listen_netaddr,
						    interface.address.zone);
			}
			isc_sockaddr_fromnetaddr(&listen_sockaddr,
						 &listen_netaddr,
						 le->port);

			/*
			 * See if the address matches the listen-on statement;
			 * if not, ignore the interface.
			 */
			(void)dns_acl_match(&listen_netaddr, NULL, le->acl,
					    &mgr->aclenv, &match, NULL);
			if (match <= 0)
				continue;

			if (adjusting == ISC_FALSE && dolistenon == ISC_TRUE) {
				setup_listenon(mgr, &interface, le->port);
				dolistenon = ISC_FALSE;
			}

			/*
			 * The case of "any" IPv6 address will require
			 * special considerations later, so remember it.
			 */
			if (family == AF_INET6 && ipv6only && ipv6pktinfo &&
			    listenon_is_ip6_any(le))
				ipv6_wildcard = ISC_TRUE;

			/*
			 * When adjusting interfaces with extra a listening
			 * list, see if the address matches the extra list.
			 * If it does, and is also covered by a wildcard
			 * interface, we need to listen on the address
			 * explicitly.
			 */
			if (adjusting == ISC_TRUE) {
				ns_listenelt_t *ele;

				match = 0;
				for (ele = ISC_LIST_HEAD(ext_listen->elts);
				     ele != NULL;
				     ele = ISC_LIST_NEXT(ele, link)) {
					(void)dns_acl_match(&listen_netaddr,
							    NULL, ele->acl,
							    NULL, &match, NULL);
					if (match > 0 && ele->port == le->port)
						break;
					else
						match = 0;
				}
				if (ipv6_wildcard == ISC_TRUE && match == 0)
					continue;
			}

			ifp = find_matching_interface(mgr, &listen_sockaddr);
			if (ifp != NULL) {
				ifp->generation = mgr->generation;
			} else {
				char sabuf[ISC_SOCKADDR_FORMATSIZE];

				if (adjusting == ISC_FALSE &&
				    ipv6_wildcard == ISC_TRUE)
					continue;

				if (log_explicit && family == AF_INET6 &&
				    !adjusting && listenon_is_ip6_any(le)) {
					isc_log_write(IFMGR_COMMON_LOGARGS,
						      verbose ? ISC_LOG_INFO :
							      ISC_LOG_DEBUG(1),
						      "IPv6 socket API is "
						      "incomplete; explicitly "
						      "binding to each IPv6 "
						      "address separately");
					log_explicit = ISC_FALSE;
				}
				isc_sockaddr_format(&listen_sockaddr,
						    sabuf, sizeof(sabuf));
				isc_log_write(IFMGR_COMMON_LOGARGS,
					      ISC_LOG_INFO,
					      "%s"
					      "listening on %s interface "
					      "%s, %s",
					      (adjusting == ISC_TRUE) ?
					      "additionally " : "",
					      (family == AF_INET) ?
					      "IPv4" : "IPv6",
					      interface.name, sabuf);

				result = ns_interface_setup(mgr,
							    &listen_sockaddr,
							    interface.name,
							    &ifp,
							    (adjusting == ISC_TRUE) ?
							    ISC_FALSE :
							    ISC_TRUE);

				if (result != ISC_R_SUCCESS) {
					isc_log_write(IFMGR_COMMON_LOGARGS,
						      ISC_LOG_ERROR,
						      "creating %s interface "
						      "%s failed; interface "
						      "ignored",
						      (family == AF_INET) ?
						      "IPv4" : "IPv6",
						      interface.name);
				}
				/* Continue. */
			}

		}
		continue;

	ignore_interface:
		isc_log_write(IFMGR_COMMON_LOGARGS,
			      ISC_LOG_ERROR,
			      "ignoring %s interface %s: %s",
			      (family == AF_INET) ? "IPv4" : "IPv6",
			      interface.name, isc_result_totext(result));
		continue;
	}
	if (result != ISC_R_NOMORE)
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "interface iteration failed: %s",
				 isc_result_totext(result));
	else 
		result = ISC_R_SUCCESS;
 cleanup_iter:
	isc_interfaceiter_destroy(&iter);
	return (result);
}

static void
ns_interfacemgr_scan0(ns_interfacemgr_t *mgr, ns_listenlist_t *ext_listen,
		      isc_boolean_t verbose)
{
	isc_boolean_t purge = ISC_TRUE;

	REQUIRE(NS_INTERFACEMGR_VALID(mgr));

	mgr->generation++;	/* Increment the generation count. */

	if (do_scan(mgr, ext_listen, verbose) != ISC_R_SUCCESS)
		purge = ISC_FALSE;

	/*
	 * Now go through the interface list and delete anything that
	 * does not have the current generation number.  This is
	 * how we catch interfaces that go away or change their
	 * addresses.
	 */
	if (purge)
		purge_old_interfaces(mgr);

	/*
	 * Warn if we are not listening on any interface, unless
	 * we're in lwresd-only mode, in which case that is to 
	 * be expected.
	 */
	if (ext_listen == NULL &&
	    ISC_LIST_EMPTY(mgr->interfaces) && ! ns_g_lwresdonly) {
		isc_log_write(IFMGR_COMMON_LOGARGS, ISC_LOG_WARNING,
			      "not listening on any interfaces");
	}
}

void
ns_interfacemgr_scan(ns_interfacemgr_t *mgr, isc_boolean_t verbose) {
	ns_interfacemgr_scan0(mgr, NULL, verbose);
}

void
ns_interfacemgr_adjust(ns_interfacemgr_t *mgr, ns_listenlist_t *list,
		       isc_boolean_t verbose)
{
	ns_interfacemgr_scan0(mgr, list, verbose);
}

void
ns_interfacemgr_setlistenon4(ns_interfacemgr_t *mgr, ns_listenlist_t *value) {
	LOCK(&mgr->lock);
	ns_listenlist_detach(&mgr->listenon4);
	ns_listenlist_attach(value, &mgr->listenon4);
	UNLOCK(&mgr->lock);
}

void
ns_interfacemgr_setlistenon6(ns_interfacemgr_t *mgr, ns_listenlist_t *value) {
	LOCK(&mgr->lock);
	ns_listenlist_detach(&mgr->listenon6);
	ns_listenlist_attach(value, &mgr->listenon6);
	UNLOCK(&mgr->lock);
}

void
ns_interfacemgr_dumprecursing(FILE *f, ns_interfacemgr_t *mgr) {
	ns_interface_t *interface;

	LOCK(&mgr->lock);
	interface = ISC_LIST_HEAD(mgr->interfaces);
	while (interface != NULL) {
		if (interface->clientmgr != NULL)
			ns_client_dumprecursing(f, interface->clientmgr);
		interface = ISC_LIST_NEXT(interface, link);
	}
	UNLOCK(&mgr->lock);
}

isc_boolean_t
ns_interfacemgr_listeningon(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr) {
	isc_sockaddr_t *old;

	old = ISC_LIST_HEAD(mgr->listenon);
	for (old = ISC_LIST_HEAD(mgr->listenon);
	     old != NULL;
	     old = ISC_LIST_NEXT(old, link))
		if (isc_sockaddr_equal(old, addr))
			return (ISC_TRUE);
	return (ISC_FALSE);
}