]> git.meshlink.io Git - catta/blobdiff - avahi-core/iface.c
publish_no_reverse configuration flag added
[catta] / avahi-core / iface.c
index ff7106bf5d0d0e1ff57192ca6d1d9c4c084f2642..60a4f4939168df95c15a2d0ab21ad845843a2bb7 100644 (file)
@@ -1,18 +1,16 @@
-/* $Id$ */
-
 /***
   This file is part of avahi.
+
   avahi is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.
+
   avahi is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
   Public License for more details.
+
   You should have received a copy of the GNU Lesser General Public
   License along with avahi; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 #endif
 
 #include <string.h>
-#include <sys/socket.h>
-#include <asm/types.h>
-#include <linux/netlink.h>
-#include <linux/rtnetlink.h>
 #include <errno.h>
-#include <net/if.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#include <avahi-common/error.h>
+#include <avahi-common/malloc.h>
+#include <avahi-common/domain.h>
 
 #include "iface.h"
-#include "netlink.h"
 #include "dns.h"
 #include "socket.h"
 #include "announce.h"
-
-static void update_address_rr(AvahiInterfaceMonitor *m, AvahiInterfaceAddress *a, gboolean remove) {
-    g_assert(m);
-    g_assert(a);
-
-    if (avahi_interface_address_relevant(a) &&
-        !remove &&
-        m->server->config.register_addresses &&
+#include "util.h"
+#include "log.h"
+#include "multicast-lookup.h"
+#include "querier.h"
+
+void avahi_interface_address_update_rrs(AvahiInterfaceAddress *a, int remove_rrs) {
+    AvahiInterfaceMonitor *m;
+
+    assert(a);
+    m = a->monitor;
+
+    if (m->list_complete &&
+        avahi_interface_address_is_relevant(a) &&
+        avahi_interface_is_relevant(a->interface) &&
+        !remove_rrs &&
+        m->server->config.publish_addresses &&
         (m->server->state == AVAHI_SERVER_RUNNING ||
         m->server->state == AVAHI_SERVER_REGISTERING)) {
 
-        if (!a->entry_group) {
-            a->entry_group = avahi_entry_group_new(m->server, avahi_host_rr_entry_group_callback, NULL);
-            avahi_server_add_address(m->server, a->entry_group, a->interface->hardware->index, a->interface->protocol, 0, NULL, &a->address); 
-            avahi_entry_group_commit(a->entry_group);
+        /* Fill the entry group */
+        if (!a->entry_group)
+            a->entry_group = avahi_s_entry_group_new(m->server, avahi_host_rr_entry_group_callback, NULL);
+
+        if (!a->entry_group) /* OOM */
+            return;
+
+        if (avahi_s_entry_group_is_empty(a->entry_group)) {
+            char t[AVAHI_ADDRESS_STR_MAX];
+            AvahiProtocol p;
+
+            p = (a->interface->protocol == AVAHI_PROTO_INET && m->server->config.publish_a_on_ipv6) ||
+                (a->interface->protocol == AVAHI_PROTO_INET6 && m->server->config.publish_aaaa_on_ipv4) ? AVAHI_PROTO_UNSPEC : a->interface->protocol;
+
+            avahi_address_snprint(t, sizeof(t), &a->address);
+            avahi_log_info("Registering new address record for %s on %s.%s.", t, a->interface->hardware->name, p == AVAHI_PROTO_UNSPEC ? "*" : avahi_proto_to_string(p));
+
+            if (avahi_server_add_address(m->server, a->entry_group, a->interface->hardware->index, p, m->server->config.publish_no_reverse ? AVAHI_PUBLISH_NO_REVERSE : 0, NULL, &a->address) < 0) {
+                avahi_log_warn(__FILE__": avahi_server_add_address() failed: %s", avahi_strerror(m->server->error));
+                avahi_s_entry_group_free(a->entry_group);
+                a->entry_group = NULL;
+                return;
+            }
+
+            avahi_s_entry_group_commit(a->entry_group);
         }
     } else {
 
-        if (a->entry_group) {
+        /* Clear the entry group */
+
+        if (a->entry_group && !avahi_s_entry_group_is_empty(a->entry_group)) {
+            char t[AVAHI_ADDRESS_STR_MAX];
+            avahi_address_snprint(t, sizeof(t), &a->address);
+
+            avahi_log_info("Withdrawing address record for %s on %s.", t, a->interface->hardware->name);
 
-            if (avahi_entry_group_get_state(a->entry_group) == AVAHI_ENTRY_GROUP_REGISTERING)
+            if (avahi_s_entry_group_get_state(a->entry_group) == AVAHI_ENTRY_GROUP_REGISTERING &&
+                m->server->state == AVAHI_SERVER_REGISTERING)
                 avahi_server_decrease_host_rr_pending(m->server);
-            
-            avahi_entry_group_free(a->entry_group);
-            a->entry_group = NULL;
+
+            avahi_s_entry_group_reset(a->entry_group);
         }
-    } 
+    }
 }
 
-static void update_interface_rr(AvahiInterfaceMonitor *m, AvahiInterface *i, gboolean remove) {
+void avahi_interface_update_rrs(AvahiInterface *i, int remove_rrs) {
     AvahiInterfaceAddress *a;
-    
-    g_assert(m);
-    g_assert(i);
+
+    assert(i);
 
     for (a = i->addresses; a; a = a->address_next)
-        update_address_rr(m, a, remove);
+        avahi_interface_address_update_rrs(a, remove_rrs);
 }
 
-static void update_hw_interface_rr(AvahiInterfaceMonitor *m, AvahiHwInterface *hw, gboolean remove) {
+void avahi_hw_interface_update_rrs(AvahiHwInterface *hw, int remove_rrs) {
     AvahiInterface *i;
+    AvahiInterfaceMonitor *m;
 
-    g_assert(m);
-    g_assert(hw);
+    assert(hw);
+    m = hw->monitor;
 
     for (i = hw->interfaces; i; i = i->by_hardware_next)
-        update_interface_rr(m, i, remove);
+        avahi_interface_update_rrs(i, remove_rrs);
+
+    if (m->list_complete &&
+        !remove_rrs &&
+        m->server->config.publish_workstation &&
+        (m->server->state == AVAHI_SERVER_RUNNING)) {
+
+        if (!hw->entry_group)
+            hw->entry_group = avahi_s_entry_group_new(m->server, avahi_host_rr_entry_group_callback, NULL);
+
+        if (!hw->entry_group)
+            return; /* OOM */
+
+        if (avahi_s_entry_group_is_empty(hw->entry_group)) {
+            char name[AVAHI_LABEL_MAX], unescaped[AVAHI_LABEL_MAX], mac[256];
+            const char *p = m->server->host_name;
+
+            avahi_unescape_label(&p, unescaped, sizeof(unescaped));
+            avahi_format_mac_address(mac, sizeof(mac), hw->mac_address, hw->mac_address_size);
+            snprintf(name, sizeof(name), "%s [%s]", unescaped, mac);
+
+            if (avahi_server_add_service(m->server, hw->entry_group, hw->index, AVAHI_PROTO_UNSPEC, 0, name, "_workstation._tcp", NULL, NULL, 9, NULL) < 0) {
+                avahi_log_warn(__FILE__": avahi_server_add_service() failed: %s", avahi_strerror(m->server->error));
+                avahi_s_entry_group_free(hw->entry_group);
+                hw->entry_group = NULL;
+            } else
+                avahi_s_entry_group_commit(hw->entry_group);
+        }
+
+    } else {
+
+        if (hw->entry_group && !avahi_s_entry_group_is_empty(hw->entry_group)) {
+
+            avahi_log_info("Withdrawing workstation service for %s.", hw->name);
+
+            if (avahi_s_entry_group_get_state(hw->entry_group) == AVAHI_ENTRY_GROUP_REGISTERING &&
+                m->server->state == AVAHI_SERVER_REGISTERING)
+                avahi_server_decrease_host_rr_pending(m->server);
+
+            avahi_s_entry_group_reset(hw->entry_group);
+        }
+    }
+}
+
+void avahi_interface_monitor_update_rrs(AvahiInterfaceMonitor *m, int remove_rrs) {
+    AvahiHwInterface *hw;
+
+    assert(m);
+
+    for (hw = m->hw_interfaces; hw; hw = hw->hardware_next)
+        avahi_hw_interface_update_rrs(hw, remove_rrs);
+}
+
+static int interface_mdns_mcast_join(AvahiInterface *i, int join) {
+    char at[AVAHI_ADDRESS_STR_MAX];
+    int r;
+    assert(i);
+
+    if (!!join  == !!i->mcast_joined)
+        return 0;
+
+    if ((i->protocol == AVAHI_PROTO_INET6 && i->monitor->server->fd_ipv6 < 0) ||
+        (i->protocol == AVAHI_PROTO_INET && i->monitor->server->fd_ipv4 < 0))
+        return -1;
+
+    if (join) {
+        AvahiInterfaceAddress *a;
+
+        /* Look if there's an address with global scope */
+        for (a = i->addresses; a; a = a->address_next)
+            if (a->global_scope)
+                break;
+
+        /* No address with a global scope has been found, so let's use
+         * any. */
+        if (!a)
+            a = i->addresses;
+
+        /* Hmm, there is no address available. */
+        if (!a)
+            return -1;
+
+        i->local_mcast_address = a->address;
+    }
+
+    avahi_log_info("%s mDNS multicast group on interface %s.%s with address %s.",
+                   join ? "Joining" : "Leaving",
+                   i->hardware->name,
+                   avahi_proto_to_string(i->protocol),
+                   avahi_address_snprint(at, sizeof(at), &i->local_mcast_address));
+
+    if (i->protocol == AVAHI_PROTO_INET6)
+        r = avahi_mdns_mcast_join_ipv6(i->monitor->server->fd_ipv6, &i->local_mcast_address.data.ipv6, i->hardware->index, join);
+    else {
+        assert(i->protocol == AVAHI_PROTO_INET);
+
+        r = avahi_mdns_mcast_join_ipv4(i->monitor->server->fd_ipv4, &i->local_mcast_address.data.ipv4, i->hardware->index, join);
+    }
+
+    if (r < 0)
+        i->mcast_joined = 0;
+    else
+        i->mcast_joined = join;
+
+    return 0;
 }
 
-static void free_address(AvahiInterfaceMonitor *m, AvahiInterfaceAddress *a) {
-    g_assert(m);
-    g_assert(a);
-    g_assert(a->interface);
+static int interface_mdns_mcast_rejoin(AvahiInterface *i) {
+    AvahiInterfaceAddress *a, *usable = NULL, *found = NULL;
+    assert(i);
+
+    if (!i->mcast_joined)
+        return 0;
 
+    /* Check whether old address we joined with is still available. If
+     * not, rejoin using an other address. */
+
+    for (a = i->addresses; a; a = a->address_next) {
+        if (a->global_scope && !usable)
+            usable = a;
+
+        if (avahi_address_cmp(&a->address, &i->local_mcast_address) == 0) {
+
+            if (a->global_scope)
+                /* No action necessary: the address still exists and
+                 * has global scope. */
+                return 0;
+
+            found = a;
+        }
+    }
+
+    if (found && !usable)
+        /* No action necessary: the address still exists and no better one has been found */
+        return 0;
+
+    interface_mdns_mcast_join(i, 0);
+    return interface_mdns_mcast_join(i, 1);
+}
+
+void avahi_interface_address_free(AvahiInterfaceAddress *a) {
+    assert(a);
+    assert(a->interface);
+
+    avahi_interface_address_update_rrs(a, 1);
     AVAHI_LLIST_REMOVE(AvahiInterfaceAddress, address, a->interface->addresses, a);
 
     if (a->entry_group)
-        avahi_entry_group_free(a->entry_group);
-    
-    g_free(a);
+        avahi_s_entry_group_free(a->entry_group);
+
+    interface_mdns_mcast_rejoin(a->interface);
+
+    avahi_free(a);
 }
 
-static void free_interface(AvahiInterfaceMonitor *m, AvahiInterface *i, gboolean send_goodbye) {
-    g_assert(m);
-    g_assert(i);
+void avahi_interface_free(AvahiInterface *i, int send_goodbye) {
+    assert(i);
 
-    avahi_goodbye_interface(m->server, i, send_goodbye);
+    /* Handle goodbyes and remove announcers */
+    avahi_goodbye_interface(i->monitor->server, i, send_goodbye, 1);
     avahi_response_scheduler_force(i->response_scheduler);
-    
-    g_assert(!i->announcements);
+    assert(!i->announcers);
+
+    if (i->mcast_joined)
+        interface_mdns_mcast_join(i, 0);
+
+    /* Remove queriers */
+    avahi_querier_free_all(i);
+    avahi_hashmap_free(i->queriers_by_key);
+
+    /* Remove local RRs */
+    avahi_interface_update_rrs(i, 1);
 
     while (i->addresses)
-        free_address(m, i->addresses);
+        avahi_interface_address_free(i->addresses);
 
     avahi_response_scheduler_free(i->response_scheduler);
     avahi_query_scheduler_free(i->query_scheduler);
     avahi_probe_scheduler_free(i->probe_scheduler);
     avahi_cache_free(i->cache);
-    
-    AVAHI_LLIST_REMOVE(AvahiInterface, interface, m->interfaces, i);
-    AVAHI_LLIST_REMOVE(AvahiInterface, by_hardware, i->hardware->interfaces, i);
-    
-    g_free(i);
-}
-
-static void free_hw_interface(AvahiInterfaceMonitor *m, AvahiHwInterface *hw, gboolean send_goodbye) {
-    g_assert(m);
-    g_assert(hw);
 
-    while (hw->interfaces)
-        free_interface(m, hw->interfaces, send_goodbye);
-
-    AVAHI_LLIST_REMOVE(AvahiHwInterface, hardware, m->hw_interfaces, hw);
-    g_hash_table_remove(m->hash_table, &hw->index);
+    AVAHI_LLIST_REMOVE(AvahiInterface, interface, i->monitor->interfaces, i);
+    AVAHI_LLIST_REMOVE(AvahiInterface, by_hardware, i->hardware->interfaces, i);
 
-    g_free(hw->name);
-    g_free(hw);
+    avahi_free(i);
 }
 
-static AvahiInterfaceAddress* get_address(AvahiInterfaceMonitor *m, AvahiInterface *i, const AvahiAddress *raddr) {
-    AvahiInterfaceAddress *ia;
-    
-    g_assert(m);
-    g_assert(i);
-    g_assert(raddr);
+void avahi_hw_interface_free(AvahiHwInterface *hw, int send_goodbye) {
+    assert(hw);
 
-    for (ia = i->addresses; ia; ia = ia->address_next)
-        if (avahi_address_cmp(&ia->address, raddr) == 0)
-            return ia;
+    avahi_hw_interface_update_rrs(hw, 1);
 
-    return NULL;
-}
+    while (hw->interfaces)
+        avahi_interface_free(hw->interfaces, send_goodbye);
 
-static int netlink_list_items(AvahiNetlink *nl, guint16 type, guint *ret_seq) {
-    struct nlmsghdr *n;
-    struct rtgenmsg *gen;
-    guint8 req[1024];
-    
-    memset(&req, 0, sizeof(req));
-    n = (struct nlmsghdr*) req;
-    n->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg));
-    n->nlmsg_type = type;
-    n->nlmsg_flags = NLM_F_ROOT/*|NLM_F_MATCH*/|NLM_F_REQUEST;
-    n->nlmsg_pid = 0;
+    if (hw->entry_group)
+        avahi_s_entry_group_free(hw->entry_group);
 
-    gen = NLMSG_DATA(n);
-    memset(gen, 0, sizeof(struct rtgenmsg));
-    gen->rtgen_family = AF_UNSPEC;
+    AVAHI_LLIST_REMOVE(AvahiHwInterface, hardware, hw->monitor->hw_interfaces, hw);
+    avahi_hashmap_remove(hw->monitor->hashmap, &hw->index);
 
-    return avahi_netlink_send(nl, n, ret_seq);
+    avahi_free(hw->name);
+    avahi_free(hw);
 }
 
-static void new_interface(AvahiInterfaceMonitor *m, AvahiHwInterface *hw, guchar protocol) {
+AvahiInterface* avahi_interface_new(AvahiInterfaceMonitor *m, AvahiHwInterface *hw, AvahiProtocol protocol) {
     AvahiInterface *i;
-    
-    g_assert(m);
-    g_assert(hw);
-    g_assert(protocol != AF_UNSPEC);
 
-    i = g_new(AvahiInterface, 1);
+    assert(m);
+    assert(hw);
+    assert(AVAHI_PROTO_VALID(protocol));
+
+    if (!(i = avahi_new(AvahiInterface, 1)))
+        goto fail; /* OOM */
+
     i->monitor = m;
     i->hardware = hw;
     i->protocol = protocol;
-    i->announcing = FALSE;
+    i->announcing = 0;
+    i->mcast_joined = 0;
 
     AVAHI_LLIST_HEAD_INIT(AvahiInterfaceAddress, i->addresses);
-    AVAHI_LLIST_HEAD_INIT(AvahiAnnouncement, i->announcements);
+    AVAHI_LLIST_HEAD_INIT(AvahiAnnouncer, i->announcers);
+
+    AVAHI_LLIST_HEAD_INIT(AvahiQuerier, i->queriers);
+    i->queriers_by_key = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, NULL, NULL);
 
     i->cache = avahi_cache_new(m->server, i);
     i->response_scheduler = avahi_response_scheduler_new(i);
     i->query_scheduler = avahi_query_scheduler_new(i);
     i->probe_scheduler = avahi_probe_scheduler_new(i);
 
+    if (!i->cache || !i->response_scheduler || !i->query_scheduler || !i->probe_scheduler)
+        goto fail; /* OOM */
+
     AVAHI_LLIST_PREPEND(AvahiInterface, by_hardware, hw->interfaces, i);
     AVAHI_LLIST_PREPEND(AvahiInterface, interface, m->interfaces, i);
-}
 
-static void check_interface_relevant(AvahiInterfaceMonitor *m, AvahiInterface *i) {
-    gboolean b;
+    return i;
 
-    g_assert(m);
-    g_assert(i);
+fail:
 
-    b = avahi_interface_relevant(i);
+    if (i) {
+        if (i->cache)
+            avahi_cache_free(i->cache);
+        if (i->response_scheduler)
+            avahi_response_scheduler_free(i->response_scheduler);
+        if (i->query_scheduler)
+            avahi_query_scheduler_free(i->query_scheduler);
+        if (i->probe_scheduler)
+            avahi_probe_scheduler_free(i->probe_scheduler);
+    }
 
-    if (b && !i->announcing) {
-        g_message("New relevant interface %s.%i (#%i)", i->hardware->name, i->protocol, i->hardware->index);
+    return NULL;
+}
 
-        if (i->protocol == AF_INET)
-            avahi_mdns_mcast_join_ipv4(i->hardware->index, m->server->fd_ipv4);
-        if (i->protocol == AF_INET6)
-            avahi_mdns_mcast_join_ipv6(i->hardware->index, m->server->fd_ipv6);
+AvahiHwInterface *avahi_hw_interface_new(AvahiInterfaceMonitor *m, AvahiIfIndex idx) {
+    AvahiHwInterface *hw;
 
-        i->announcing = TRUE;
-        avahi_announce_interface(m->server, i);
-    } else if (!b && i->announcing) {
-        g_message("Interface %s.%i no longer relevant", i->hardware->name, i->protocol);
+    assert(m);
+    assert(AVAHI_IF_VALID(idx));
 
-        if (i->protocol == AF_INET)
-            avahi_mdns_mcast_leave_ipv4(i->hardware->index, m->server->fd_ipv4);
-        if (i->protocol == AF_INET6)
-            avahi_mdns_mcast_leave_ipv6(i->hardware->index, m->server->fd_ipv6);
+    if  (!(hw = avahi_new(AvahiHwInterface, 1)))
+        return NULL;
 
-        avahi_goodbye_interface(m->server, i, FALSE);
-        avahi_response_scheduler_clear(i->response_scheduler);
-        avahi_query_scheduler_clear(i->query_scheduler);
-        avahi_probe_scheduler_clear(i->probe_scheduler);
-        avahi_cache_flush(i->cache);
+    hw->monitor = m;
+    hw->name = NULL;
+    hw->flags_ok = 0;
+    hw->mtu = 1500;
+    hw->index = idx;
+    hw->mac_address_size = 0;
+    hw->entry_group = NULL;
+    hw->ratelimit_begin.tv_sec = 0;
+    hw->ratelimit_begin.tv_usec = 0;
+    hw->ratelimit_counter = 0;
 
-        i->announcing = FALSE;
-    }
-}
+    AVAHI_LLIST_HEAD_INIT(AvahiInterface, hw->interfaces);
+    AVAHI_LLIST_PREPEND(AvahiHwInterface, hardware, m->hw_interfaces, hw);
 
-static void check_hw_interface_relevant(AvahiInterfaceMonitor *m, AvahiHwInterface *hw) {
-    AvahiInterface *i;
-    
-    g_assert(m);
-    g_assert(hw);
+    avahi_hashmap_insert(m->hashmap, &hw->index, hw);
 
-    for (i = hw->interfaces; i; i = i->by_hardware_next)
-        check_interface_relevant(m, i);
+    if (m->server->fd_ipv4 >= 0 || m->server->config.publish_a_on_ipv6)
+        avahi_interface_new(m, hw, AVAHI_PROTO_INET);
+    if (m->server->fd_ipv6 >= 0 || m->server->config.publish_aaaa_on_ipv4)
+        avahi_interface_new(m, hw, AVAHI_PROTO_INET6);
+
+    return hw;
 }
 
-static void callback(AvahiNetlink *nl, struct nlmsghdr *n, gpointer userdata) {
-    AvahiInterfaceMonitor *m = userdata;
-    
-    g_assert(m);
-    g_assert(n);
-    g_assert(m->netlink == nl);
+AvahiInterfaceAddress *avahi_interface_address_new(AvahiInterfaceMonitor *m, AvahiInterface *i, const AvahiAddress *addr, unsigned prefix_len) {
+    AvahiInterfaceAddress *a;
 
-    if (n->nlmsg_type == RTM_NEWLINK) {
-        struct ifinfomsg *ifinfomsg = NLMSG_DATA(n);
-        AvahiHwInterface *hw;
-        struct rtattr *a = NULL;
-        size_t l;
+    assert(m);
+    assert(i);
 
-        if (ifinfomsg->ifi_family != AF_UNSPEC)
-            return;
+    if (!(a = avahi_new(AvahiInterfaceAddress, 1)))
+        return NULL;
 
-        if (!(hw = g_hash_table_lookup(m->hash_table, &ifinfomsg->ifi_index))) {
-            hw = g_new(AvahiHwInterface, 1);
-            hw->monitor = m;
-            hw->name = NULL;
-            hw->flags = 0;
-            hw->mtu = 1500;
-            hw->index = ifinfomsg->ifi_index;
-
-            AVAHI_LLIST_HEAD_INIT(AvahiInterface, hw->interfaces);
-            AVAHI_LLIST_PREPEND(AvahiHwInterface, hardware, m->hw_interfaces, hw);
-            
-            g_hash_table_insert(m->hash_table, &hw->index, hw);
-
-            if (m->server->fd_ipv4 >= 0)
-                new_interface(m, hw, AF_INET);
-            if (m->server->fd_ipv6 >= 0)
-                new_interface(m, hw, AF_INET6);
-        }
-        
-        hw->flags = ifinfomsg->ifi_flags;
+    a->interface = i;
+    a->monitor = m;
+    a->address = *addr;
+    a->prefix_len = prefix_len;
+    a->global_scope = 0;
+    a->deprecated = 0;
+    a->entry_group = NULL;
 
-        l = NLMSG_PAYLOAD(n, sizeof(struct ifinfomsg));
-        a = IFLA_RTA(ifinfomsg);
+    AVAHI_LLIST_PREPEND(AvahiInterfaceAddress, address, i->addresses, a);
 
-        while (RTA_OK(a, l)) {
-            switch(a->rta_type) {
-                case IFLA_IFNAME:
-                    g_free(hw->name);
-                    hw->name = g_strndup(RTA_DATA(a), RTA_PAYLOAD(a));
-                    break;
+    return a;
+}
 
-                case IFLA_MTU:
-                    g_assert(RTA_PAYLOAD(a) == sizeof(unsigned int));
-                    hw->mtu = *((unsigned int*) RTA_DATA(a));
-                    break;
-                    
-                default:
-                    ;
-            }
+void avahi_interface_check_relevant(AvahiInterface *i) {
+    int b;
+    AvahiInterfaceMonitor *m;
 
-            a = RTA_NEXT(a, l);
-        }
+    assert(i);
+    m = i->monitor;
 
-        update_hw_interface_rr(m, hw, FALSE);
-        check_hw_interface_relevant(m, hw);
-        
-    } else if (n->nlmsg_type == RTM_DELLINK) {
-        struct ifinfomsg *ifinfomsg = NLMSG_DATA(n);
-        AvahiHwInterface *hw;
+    b = avahi_interface_is_relevant(i);
 
-        if (ifinfomsg->ifi_family != AF_UNSPEC)
-            return;
-        
-        if (!(hw = avahi_interface_monitor_get_hw_interface(m, ifinfomsg->ifi_index)))
-            return;
+    if (m->list_complete && b && !i->announcing) {
+        interface_mdns_mcast_join(i, 1);
 
-        update_hw_interface_rr(m, hw, TRUE);
-        free_hw_interface(m, hw, FALSE);
-        
-    } else if (n->nlmsg_type == RTM_NEWADDR || n->nlmsg_type == RTM_DELADDR) {
+        if (i->mcast_joined) {
+            avahi_log_info("New relevant interface %s.%s for mDNS.", i->hardware->name, avahi_proto_to_string(i->protocol));
 
-        struct ifaddrmsg *ifaddrmsg = NLMSG_DATA(n);
-        AvahiInterface *i;
-        struct rtattr *a = NULL;
-        size_t l;
-        AvahiAddress raddr;
-        gboolean raddr_valid = FALSE;
+            i->announcing = 1;
+            avahi_announce_interface(m->server, i);
+            avahi_multicast_lookup_engine_new_interface(m->server->multicast_lookup_engine, i);
+        }
 
-        if (ifaddrmsg->ifa_family != AF_INET && ifaddrmsg->ifa_family != AF_INET6)
-            return;
+    } else if (!b && i->announcing) {
+        avahi_log_info("Interface %s.%s no longer relevant for mDNS.", i->hardware->name, avahi_proto_to_string(i->protocol));
 
-        if (!(i = (AvahiInterface*) avahi_interface_monitor_get_interface(m, ifaddrmsg->ifa_index, ifaddrmsg->ifa_family)))
-            return;
+        interface_mdns_mcast_join(i, 0);
 
-        raddr.family = ifaddrmsg->ifa_family;
+        avahi_goodbye_interface(m->server, i, 0, 1);
+        avahi_querier_free_all(i);
 
-        l = NLMSG_PAYLOAD(n, sizeof(struct ifaddrmsg));
-        a = IFA_RTA(ifaddrmsg);
+        avahi_response_scheduler_clear(i->response_scheduler);
+        avahi_query_scheduler_clear(i->query_scheduler);
+        avahi_probe_scheduler_clear(i->probe_scheduler);
+        avahi_cache_flush(i->cache);
 
-        while (RTA_OK(a, l)) {
+        i->announcing = 0;
 
-            switch(a->rta_type) {
-                case IFA_ADDRESS:
-                    if ((raddr.family == AF_INET6 && RTA_PAYLOAD(a) != 16) ||
-                        (raddr.family == AF_INET && RTA_PAYLOAD(a) != 4))
-                        return;
+    } else
+        interface_mdns_mcast_rejoin(i);
+}
 
-                    memcpy(raddr.data.data, RTA_DATA(a), RTA_PAYLOAD(a));
-                    raddr_valid = TRUE;
+void avahi_hw_interface_check_relevant(AvahiHwInterface *hw) {
+    AvahiInterface *i;
 
-                    break;
-                    
-                default:
-                    ;
-            }
-            
-            a = RTA_NEXT(a, l);
-        }
-        
-        if (!raddr_valid)
-            return;
+    assert(hw);
 
-        if (n->nlmsg_type == RTM_NEWADDR) {
-            AvahiInterfaceAddress *addr;
-            
-            if (!(addr = get_address(m, i, &raddr))) {
-                addr = g_new(AvahiInterfaceAddress, 1);
-                addr->monitor = m;
-                addr->address = raddr;
-                addr->interface = i;
-                addr->entry_group = NULL;
-
-                AVAHI_LLIST_PREPEND(AvahiInterfaceAddress, address, i->addresses, addr);
-            }
-            
-            addr->flags = ifaddrmsg->ifa_flags;
-            addr->scope = ifaddrmsg->ifa_scope;
+    for (i = hw->interfaces; i; i = i->by_hardware_next)
+        avahi_interface_check_relevant(i);
+}
 
-            update_address_rr(m, addr, FALSE);
-            check_interface_relevant(m, i);
-        } else {
-            AvahiInterfaceAddress *addr;
-            
-            if (!(addr = get_address(m, i, &raddr)))
-                return;
+void avahi_interface_monitor_check_relevant(AvahiInterfaceMonitor *m) {
+    AvahiInterface *i;
 
-            update_address_rr(m, addr, TRUE);
-            free_address(m, addr);
+    assert(m);
 
-            check_interface_relevant(m, i);
-        }
-                
-    } else if (n->nlmsg_type == NLMSG_DONE) {
-        
-        if (m->list == LIST_IFACE) {
-            m->list = LIST_DONE;
-            
-            if (netlink_list_items(m->netlink, RTM_GETADDR, &m->query_addr_seq) < 0)
-                g_warning("NETLINK: Failed to list addrs: %s", strerror(errno));
-            else
-                m->list = LIST_ADDR;
-        } else {
-            m->list = LIST_DONE;
-            g_message("Enumeration complete");
-        }
-        
-    } else if (n->nlmsg_type == NLMSG_ERROR && (n->nlmsg_seq == m->query_link_seq || n->nlmsg_seq == m->query_addr_seq)) {
-        struct nlmsgerr *e = NLMSG_DATA (n);
-                    
-        if (e->error)
-            g_warning("NETLINK: Failed to browse: %s", strerror(-e->error));
-    }
+    for (i = m->interfaces; i; i = i->interface_next)
+        avahi_interface_check_relevant(i);
 }
 
 AvahiInterfaceMonitor *avahi_interface_monitor_new(AvahiServer *s) {
     AvahiInterfaceMonitor *m = NULL;
 
-    m = g_new0(AvahiInterfaceMonitor, 1);
-    m->server = s;
-    if (!(m->netlink = avahi_netlink_new(s->context, G_PRIORITY_DEFAULT-10, RTMGRP_LINK|RTMGRP_IPV4_IFADDR|RTMGRP_IPV6_IFADDR, callback, m)))
-        goto fail;
+    if (!(m = avahi_new0(AvahiInterfaceMonitor, 1)))
+        return NULL; /* OOM */
 
-    m->hash_table = g_hash_table_new(g_int_hash, g_int_equal);
+    m->server = s;
+    m->list_complete = 0;
+    m->hashmap = avahi_hashmap_new(avahi_int_hash, avahi_int_equal, NULL, NULL);
 
     AVAHI_LLIST_HEAD_INIT(AvahiInterface, m->interfaces);
     AVAHI_LLIST_HEAD_INIT(AvahiHwInterface, m->hw_interfaces);
 
-    if (netlink_list_items(m->netlink, RTM_GETLINK, &m->query_link_seq) < 0)
+    if (avahi_interface_monitor_init_osdep(m) < 0)
         goto fail;
 
-    m->list = LIST_IFACE;
-
     return m;
 
 fail:
@@ -434,43 +509,32 @@ fail:
     return NULL;
 }
 
-void avahi_interface_monitor_sync(AvahiInterfaceMonitor *m) {
-    g_assert(m);
-    
-    while (m->list != LIST_DONE) {
-        if (!avahi_netlink_work(m->netlink, TRUE))
-            break;
-    } 
-}
-
 void avahi_interface_monitor_free(AvahiInterfaceMonitor *m) {
-    g_assert(m);
+    assert(m);
 
     while (m->hw_interfaces)
-        free_hw_interface(m, m->hw_interfaces, TRUE);
+        avahi_hw_interface_free(m->hw_interfaces, 1);
 
-    g_assert(!m->interfaces);
+    assert(!m->interfaces);
 
-    
-    if (m->netlink)
-        avahi_netlink_free(m->netlink);
-    
-    if (m->hash_table)
-        g_hash_table_destroy(m->hash_table);
+    avahi_interface_monitor_free_osdep(m);
 
-    g_free(m);
+    if (m->hashmap)
+        avahi_hashmap_free(m->hashmap);
+
+    avahi_free(m);
 }
 
 
-AvahiInterface* avahi_interface_monitor_get_interface(AvahiInterfaceMonitor *m, gint index, guchar protocol) {
+AvahiInterface* avahi_interface_monitor_get_interface(AvahiInterfaceMonitor *m, AvahiIfIndex idx, AvahiProtocol protocol) {
     AvahiHwInterface *hw;
     AvahiInterface *i;
-    
-    g_assert(m);
-    g_assert(index > 0);
-    g_assert(protocol != AF_UNSPEC);
 
-    if (!(hw = avahi_interface_monitor_get_hw_interface(m, index)))
+    assert(m);
+    assert(idx >= 0);
+    assert(protocol != AVAHI_PROTO_UNSPEC);
+
+    if (!(hw = avahi_interface_monitor_get_hw_interface(m, idx)))
         return NULL;
 
     for (i = hw->interfaces; i; i = i->by_hardware_next)
@@ -480,145 +544,202 @@ AvahiInterface* avahi_interface_monitor_get_interface(AvahiInterfaceMonitor *m,
     return NULL;
 }
 
-AvahiHwInterface* avahi_interface_monitor_get_hw_interface(AvahiInterfaceMonitor *m, gint index) {
-    g_assert(m);
-    g_assert(index > 0);
+AvahiHwInterface* avahi_interface_monitor_get_hw_interface(AvahiInterfaceMonitor *m, AvahiIfIndex idx) {
+    assert(m);
+    assert(idx >= 0);
 
-    return g_hash_table_lookup(m->hash_table, &index);
+    return avahi_hashmap_lookup(m->hashmap, &idx);
 }
 
+AvahiInterfaceAddress* avahi_interface_monitor_get_address(AvahiInterfaceMonitor *m, AvahiInterface *i, const AvahiAddress *raddr) {
+    AvahiInterfaceAddress *ia;
 
-void avahi_interface_send_packet_unicast(AvahiInterface *i, AvahiDnsPacket *p, const AvahiAddress *a, guint16 port) {
-    g_assert(i);
-    g_assert(p);
-/*     char t[64]; */
+    assert(m);
+    assert(i);
+    assert(raddr);
 
-    if (!avahi_interface_relevant(i))
+    for (ia = i->addresses; ia; ia = ia->address_next)
+        if (avahi_address_cmp(&ia->address, raddr) == 0)
+            return ia;
+
+    return NULL;
+}
+
+void avahi_interface_send_packet_unicast(AvahiInterface *i, AvahiDnsPacket *p, const AvahiAddress *a, uint16_t port) {
+    assert(i);
+    assert(p);
+
+    if (!i->announcing)
         return;
-    
-    g_assert(!a || a->family == i->protocol);
 
-/*     if (a) */
-/*         g_message("unicast sending on '%s.%i' to %s:%u", i->hardware->name, i->protocol, avahi_address_snprint(t, sizeof(t), a), port); */
-/*     else */
-/*         g_message("multicast sending on '%s.%i'", i->hardware->name, i->protocol); */
-    
-    if (i->protocol == AF_INET && i->monitor->server->fd_ipv4 >= 0)
-        avahi_send_dns_packet_ipv4(i->monitor->server->fd_ipv4, i->hardware->index, p, a ? &a->data.ipv4 : NULL, port);
-    else if (i->protocol == AF_INET6 && i->monitor->server->fd_ipv6 >= 0)
-        avahi_send_dns_packet_ipv6(i->monitor->server->fd_ipv6, i->hardware->index, p, a ? &a->data.ipv6 : NULL, port);
+    assert(!a || a->proto == i->protocol);
+
+    if (i->monitor->server->config.ratelimit_interval > 0) {
+        struct timeval now, end;
+
+        gettimeofday(&now, NULL);
+
+        end = i->hardware->ratelimit_begin;
+        avahi_timeval_add(&end, i->monitor->server->config.ratelimit_interval);
+
+        if (i->hardware->ratelimit_begin.tv_sec <= 0 ||
+            avahi_timeval_compare(&end, &now) < 0) {
+
+            i->hardware->ratelimit_begin = now;
+            i->hardware->ratelimit_counter = 0;
+        }
+
+        if (i->hardware->ratelimit_counter > i->monitor->server->config.ratelimit_burst)
+            return;
+
+        i->hardware->ratelimit_counter++;
+    }
+
+    if (i->protocol == AVAHI_PROTO_INET && i->monitor->server->fd_ipv4 >= 0)
+        avahi_send_dns_packet_ipv4(i->monitor->server->fd_ipv4, i->hardware->index, p, i->mcast_joined ? &i->local_mcast_address.data.ipv4 : NULL, a ? &a->data.ipv4 : NULL, port);
+    else if (i->protocol == AVAHI_PROTO_INET6 && i->monitor->server->fd_ipv6 >= 0)
+        avahi_send_dns_packet_ipv6(i->monitor->server->fd_ipv6, i->hardware->index, p, i->mcast_joined ? &i->local_mcast_address.data.ipv6 : NULL, a ? &a->data.ipv6 : NULL, port);
 }
 
 void avahi_interface_send_packet(AvahiInterface *i, AvahiDnsPacket *p) {
-    g_assert(i);
-    g_assert(p);
+    assert(i);
+    assert(p);
 
     avahi_interface_send_packet_unicast(i, p, NULL, 0);
 }
 
-gboolean avahi_interface_post_query(AvahiInterface *i, AvahiKey *key, gboolean immediately) {
-    g_assert(i);
-    g_assert(key);
+int avahi_interface_post_query(AvahiInterface *i, AvahiKey *key, int immediately, unsigned *ret_id) {
+    assert(i);
+    assert(key);
+
+    if (!i->announcing)
+        return 0;
+
+    return avahi_query_scheduler_post(i->query_scheduler, key, immediately, ret_id);
+}
 
-    if (avahi_interface_relevant(i))
-        return avahi_query_scheduler_post(i->query_scheduler, key, immediately);
+int avahi_interface_withraw_query(AvahiInterface *i, unsigned id) {
 
-    return FALSE;
+    return avahi_query_scheduler_withdraw_by_id(i->query_scheduler, id);
 }
 
-gboolean avahi_interface_post_response(AvahiInterface *i, AvahiRecord *record, gboolean flush_cache, const AvahiAddress *querier, gboolean immediately) {
-    g_assert(i);
-    g_assert(record);
+int avahi_interface_post_response(AvahiInterface *i, AvahiRecord *record, int flush_cache, const AvahiAddress *querier, int immediately) {
+    assert(i);
+    assert(record);
 
-    if (avahi_interface_relevant(i))
-        return avahi_response_scheduler_post(i->response_scheduler, record, flush_cache, querier, immediately);
+    if (!i->announcing)
+        return 0;
 
-    return FALSE;
+    return avahi_response_scheduler_post(i->response_scheduler, record, flush_cache, querier, immediately);
 }
 
-gboolean avahi_interface_post_probe(AvahiInterface *i, AvahiRecord *record, gboolean immediately) {
-    g_assert(i);
-    g_assert(record);
-    
-    if (avahi_interface_relevant(i))
-        return avahi_probe_scheduler_post(i->probe_scheduler, record, immediately);
+int avahi_interface_post_probe(AvahiInterface *i, AvahiRecord *record, int immediately) {
+    assert(i);
+    assert(record);
 
-    return FALSE;
+    if (!i->announcing)
+        return 0;
+
+    return avahi_probe_scheduler_post(i->probe_scheduler, record, immediately);
 }
 
-void avahi_dump_caches(AvahiInterfaceMonitor *m, FILE *f) {
+int avahi_dump_caches(AvahiInterfaceMonitor *m, AvahiDumpCallback callback, void* userdata) {
     AvahiInterface *i;
-    g_assert(m);
+    assert(m);
 
     for (i = m->interfaces; i; i = i->interface_next) {
-        if (avahi_interface_relevant(i)) {
-            fprintf(f, "\n;;; INTERFACE %s.%i ;;;\n", i->hardware->name, i->protocol);
-            avahi_cache_dump(i->cache, f);
+        if (avahi_interface_is_relevant(i)) {
+            char ln[256];
+            snprintf(ln, sizeof(ln), ";;; INTERFACE %s.%s ;;;", i->hardware->name, avahi_proto_to_string(i->protocol));
+            callback(ln, userdata);
+            if (avahi_cache_dump(i->cache, callback, userdata) < 0)
+                return -1;
         }
     }
-    fprintf(f, "\n");
+
+    return 0;
 }
 
-gboolean avahi_interface_relevant(AvahiInterface *i) {
+static int avahi_interface_is_relevant_internal(AvahiInterface *i) {
     AvahiInterfaceAddress *a;
-    gboolean relevant_address;
-    
-    g_assert(i);
 
-    relevant_address = FALSE;
-    
+    assert(i);
+
+    if (!i->hardware->flags_ok)
+        return 0;
+
     for (a = i->addresses; a; a = a->address_next)
-        if (avahi_interface_address_relevant(a)) {
-            relevant_address = TRUE;
-            break;
-        }
+        if (avahi_interface_address_is_relevant(a))
+            return 1;
 
-/*     g_message("%p. iface-relevant: %i %i %i %i %i %i", i, relevant_address, */
-/*               (i->hardware->flags & IFF_UP), */
-/*               (i->hardware->flags & IFF_RUNNING), */
-/*               !(i->hardware->flags & IFF_LOOPBACK), */
-/*               (i->hardware->flags & IFF_MULTICAST), */
-/*               !(i->hardware->flags & IFF_POINTOPOINT)); */
-    
-    return
-        (i->hardware->flags & IFF_UP) &&
-        (!i->monitor->server->config.use_iff_running || (i->hardware->flags & IFF_RUNNING)) &&
-        !(i->hardware->flags & IFF_LOOPBACK) &&
-        (i->hardware->flags & IFF_MULTICAST) &&
-        !(i->hardware->flags & IFF_POINTOPOINT) && 
-        relevant_address;
+    return 0;
 }
 
-gboolean avahi_interface_address_relevant(AvahiInterfaceAddress *a) { 
-    g_assert(a);
+int avahi_interface_is_relevant(AvahiInterface *i) {
+    AvahiStringList *l;
+    assert(i);
+
+    for (l = i->monitor->server->config.deny_interfaces; l; l = l->next)
+        if (strcasecmp((char*) l->text, i->hardware->name) == 0)
+            return 0;
+
+    if (i->monitor->server->config.allow_interfaces) {
 
-    return a->scope == RT_SCOPE_UNIVERSE;
+        for (l = i->monitor->server->config.allow_interfaces; l; l = l->next)
+            if (strcasecmp((char*) l->text, i->hardware->name) == 0)
+                goto good;
+
+        return 0;
+    }
+
+good:
+    return avahi_interface_is_relevant_internal(i);
 }
 
+int avahi_interface_address_is_relevant(AvahiInterfaceAddress *a) {
+    AvahiInterfaceAddress *b;
+    assert(a);
 
-gboolean avahi_interface_match(AvahiInterface *i, gint index, guchar protocol) {
-    g_assert(i);
-    
-    if (index > 0 && index != i->hardware->index)
-        return FALSE;
+    /* Publish public and non-deprecated IP addresses */
+    if (a->global_scope && !a->deprecated)
+        return 1;
 
-    if (protocol != AF_UNSPEC && protocol != i->protocol)
-        return FALSE;
+    /* Publish link-local and deprecated IP addresses only if they are
+     * the only ones on the link */
+    for (b = a->interface->addresses; b; b = b->address_next) {
+        if (b == a)
+            continue;
 
-    return TRUE;
+        if (b->global_scope && !b->deprecated)
+            return 0;
+    }
+
+    return 1;
 }
 
-void avahi_interface_monitor_walk(AvahiInterfaceMonitor *m, gint interface, guchar protocol, AvahiInterfaceMonitorWalkCallback callback, gpointer userdata) {
-    g_assert(m);
-    g_assert(callback);
-    
-    if (interface > 0) {
-        if (protocol != AF_UNSPEC) {
+int avahi_interface_match(AvahiInterface *i, AvahiIfIndex idx, AvahiProtocol protocol) {
+    assert(i);
+
+    if (idx != AVAHI_IF_UNSPEC && idx != i->hardware->index)
+        return 0;
+
+    if (protocol != AVAHI_PROTO_UNSPEC && protocol != i->protocol)
+        return 0;
+
+    return 1;
+}
+
+void avahi_interface_monitor_walk(AvahiInterfaceMonitor *m, AvahiIfIndex interface, AvahiProtocol protocol, AvahiInterfaceMonitorWalkCallback callback, void* userdata) {
+    assert(m);
+    assert(callback);
+
+    if (interface != AVAHI_IF_UNSPEC) {
+        if (protocol != AVAHI_PROTO_UNSPEC) {
             AvahiInterface *i;
-            
+
             if ((i = avahi_interface_monitor_get_interface(m, interface, protocol)))
                 callback(m, i, userdata);
-            
+
         } else {
             AvahiHwInterface *hw;
             AvahiInterface *i;
@@ -628,21 +749,117 @@ void avahi_interface_monitor_walk(AvahiInterfaceMonitor *m, gint interface, guch
                     if (avahi_interface_match(i, interface, protocol))
                         callback(m, i, userdata);
         }
-        
+
     } else {
         AvahiInterface *i;
-        
+
         for (i = m->interfaces; i; i = i->interface_next)
             if (avahi_interface_match(i, interface, protocol))
                 callback(m, i, userdata);
     }
 }
 
-void avahi_update_host_rrs(AvahiInterfaceMonitor *m, gboolean remove) {
-    AvahiInterface *i;
 
-    g_assert(m);
+int avahi_address_is_local(AvahiInterfaceMonitor *m, const AvahiAddress *a) {
+    AvahiInterface *i;
+    AvahiInterfaceAddress *ia;
+    assert(m);
+    assert(a);
 
     for (i = m->interfaces; i; i = i->interface_next)
-        update_interface_rr(m, i, remove);
+        for (ia = i->addresses; ia; ia = ia->address_next)
+            if (avahi_address_cmp(a, &ia->address) == 0)
+                return 1;
+
+    return 0;
+}
+
+int avahi_interface_address_on_link(AvahiInterface *i, const AvahiAddress *a) {
+    AvahiInterfaceAddress *ia;
+
+    assert(i);
+    assert(a);
+
+    if (a->proto != i->protocol)
+        return 0;
+
+    for (ia = i->addresses; ia; ia = ia->address_next) {
+
+        if (a->proto == AVAHI_PROTO_INET) {
+            uint32_t m;
+
+            m = ~(((uint32_t) -1) >> ia->prefix_len);
+
+            if ((ntohl(a->data.ipv4.address) & m) == (ntohl(ia->address.data.ipv4.address) & m))
+                return 1;
+        } else {
+            unsigned j;
+            unsigned char pl;
+            assert(a->proto == AVAHI_PROTO_INET6);
+
+            pl = ia->prefix_len;
+
+            for (j = 0; j < 16; j++) {
+                uint8_t m;
+
+                if (pl == 0)
+                    return 1;
+
+                if (pl >= 8) {
+                    m = 0xFF;
+                    pl -= 8;
+                } else {
+                    m = ~(0xFF >> pl);
+                    pl = 0;
+                }
+
+                if ((a->data.ipv6.address[j] & m) != (ia->address.data.ipv6.address[j] & m))
+                    break;
+            }
+        }
+    }
+
+    return 0;
+}
+
+int avahi_interface_has_address(AvahiInterfaceMonitor *m, AvahiIfIndex iface, const AvahiAddress *a) {
+    AvahiInterface *i;
+    AvahiInterfaceAddress *j;
+
+    assert(m);
+    assert(iface != AVAHI_IF_UNSPEC);
+    assert(a);
+
+    if (!(i = avahi_interface_monitor_get_interface(m, iface, a->proto)))
+        return 0;
+
+    for (j = i->addresses; j; j = j->address_next)
+        if (avahi_address_cmp(a, &j->address) == 0)
+            return 1;
+
+    return 0;
+}
+
+AvahiIfIndex avahi_find_interface_for_address(AvahiInterfaceMonitor *m, const AvahiAddress *a) {
+    AvahiInterface *i;
+    assert(m);
+
+    /* Some stupid OS don't support passing the interface index when a
+     * packet is received. We have to work around that limitation by
+     * looking for an interface that has the incoming address
+     * attached. This is sometimes ambiguous, but we have to live with
+     * it. */
+
+    for (i = m->interfaces; i; i = i->interface_next) {
+        AvahiInterfaceAddress *ai;
+
+        if (i->protocol != a->proto)
+            continue;
+
+        for (ai = i->addresses; ai; ai = ai->address_next)
+            if (avahi_address_cmp(a, &ai->address) == 0)
+                return i->hardware->index;
+    }
+
+    return AVAHI_IF_UNSPEC;
 }