X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-core%2Fsocket.c;h=b2d6e6fb08e098ecbb304416fbe331497b6be9e8;hb=6fc2d9e75412ef168ef3b09c091e5821fc39b99a;hp=e59c78a6fd4167ef17ff5319a5d323ccfe461161;hpb=c58379bde376cb2298fca14f83a86626f1b76f2f;p=catta

diff --git a/avahi-core/socket.c b/avahi-core/socket.c
index e59c78a..b2d6e6f 100644
--- a/avahi-core/socket.c
+++ b/avahi-core/socket.c
@@ -35,34 +35,54 @@
 #include <sys/time.h>
 #include <net/if.h>
 #include <sys/ioctl.h>
+#include <assert.h>
 
 #include "dns.h"
-#include "util.h"
+#include "fdutil.h"
 #include "socket.h"
+#include "log.h"
 
 static void mdns_mcast_group_ipv4(struct sockaddr_in *ret_sa) {
-    g_assert(ret_sa);
+    assert(ret_sa);
 
     memset(ret_sa, 0, sizeof(struct sockaddr_in));
-    
     ret_sa->sin_family = AF_INET;
     ret_sa->sin_port = htons(AVAHI_MDNS_PORT);
-    inet_pton(AF_INET, "224.0.0.251", &ret_sa->sin_addr);
+    inet_pton(AF_INET, AVAHI_IPV4_MCAST_GROUP, &ret_sa->sin_addr);
 }
 
 static void mdns_mcast_group_ipv6(struct sockaddr_in6 *ret_sa) {
-
-    g_assert(ret_sa);
+    assert(ret_sa);
 
     memset(ret_sa, 0, sizeof(struct sockaddr_in6));
-    
     ret_sa->sin6_family = AF_INET6;
     ret_sa->sin6_port = htons(AVAHI_MDNS_PORT);
-    inet_pton(AF_INET6, "ff02::fb", &ret_sa->sin6_addr);
+    inet_pton(AF_INET6, AVAHI_IPV6_MCAST_GROUP, &ret_sa->sin6_addr);
+}
+
+static void ipv4_address_to_sockaddr(struct sockaddr_in *ret_sa, const AvahiIPv4Address *a, uint16_t port) {
+    assert(ret_sa);
+    assert(a);
+    assert(port > 0);
+
+    memset(ret_sa, 0, sizeof(struct sockaddr_in));
+    ret_sa->sin_family = AF_INET;
+    ret_sa->sin_port = htons(port);
+    memcpy(&ret_sa->sin_addr, a, sizeof(AvahiIPv4Address));
 }
 
-int avahi_mdns_mcast_join_ipv4 (int index, int fd)
-{
+static void ipv6_address_to_sockaddr(struct sockaddr_in6 *ret_sa, const AvahiIPv6Address *a, uint16_t port) {
+    assert(ret_sa);
+    assert(a);
+    assert(port > 0);
+
+    memset(ret_sa, 0, sizeof(struct sockaddr_in6));
+    ret_sa->sin6_family = AF_INET6;
+    ret_sa->sin6_port = htons(port);
+    memcpy(&ret_sa->sin6_addr, a, sizeof(AvahiIPv6Address));
+}
+
+int avahi_mdns_mcast_join_ipv4(int fd, int idx) {
     struct ip_mreqn mreq; 
     struct sockaddr_in sa;
 
@@ -70,18 +90,17 @@ int avahi_mdns_mcast_join_ipv4 (int index, int fd)
  
     memset(&mreq, 0, sizeof(mreq));
     mreq.imr_multiaddr = sa.sin_addr;
-    mreq.imr_ifindex = index;
+    mreq.imr_ifindex = idx;
  
     if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
-        g_warning("IP_ADD_MEMBERSHIP failed: %s\n", strerror(errno));
+        avahi_log_warn("IP_ADD_MEMBERSHIP failed: %s\n", strerror(errno));
         return -1;
     } 
 
     return 0;
 }
 
-int avahi_mdns_mcast_join_ipv6 (int index, int fd)
-{
+int avahi_mdns_mcast_join_ipv6(int fd, int idx) {
     struct ipv6_mreq mreq6; 
     struct sockaddr_in6 sa6;
 
@@ -89,18 +108,17 @@ int avahi_mdns_mcast_join_ipv6 (int index, int fd)
 
     memset(&mreq6, 0, sizeof(mreq6));
     mreq6.ipv6mr_multiaddr = sa6.sin6_addr;
-    mreq6.ipv6mr_interface = index;
+    mreq6.ipv6mr_interface = idx;
 
     if (setsockopt(fd, SOL_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
-        g_warning("IPV6_ADD_MEMBERSHIP failed: %s\n", strerror(errno));
+        avahi_log_warn("IPV6_ADD_MEMBERSHIP failed: %s\n", strerror(errno));
         return -1;
     }
 
     return 0;
 }
 
-int avahi_mdns_mcast_leave_ipv4 (int index, int fd)
-{
+int avahi_mdns_mcast_leave_ipv4(int fd, int idx) {
     struct ip_mreqn mreq; 
     struct sockaddr_in sa;
     
@@ -108,18 +126,17 @@ int avahi_mdns_mcast_leave_ipv4 (int index, int fd)
  
     memset(&mreq, 0, sizeof(mreq));
     mreq.imr_multiaddr = sa.sin_addr;
-    mreq.imr_ifindex = index;
+    mreq.imr_ifindex = idx;
  
     if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
-        g_warning("IP_DROP_MEMBERSHIP failed: %s\n", strerror(errno));
+        avahi_log_warn("IP_DROP_MEMBERSHIP failed: %s\n", strerror(errno));
         return -1;
     }
 
     return 0;
 }
 
-int avahi_mdns_mcast_leave_ipv6 (int index, int fd)
-{
+int avahi_mdns_mcast_leave_ipv6(int fd, int idx) {
     struct ipv6_mreq mreq6; 
     struct sockaddr_in6 sa6;
 
@@ -127,78 +144,113 @@ int avahi_mdns_mcast_leave_ipv6 (int index, int fd)
 
     memset(&mreq6, 0, sizeof(mreq6));
     mreq6.ipv6mr_multiaddr = sa6.sin6_addr;
-    mreq6.ipv6mr_interface = index;
+    mreq6.ipv6mr_interface = idx;
 
     if (setsockopt(fd, SOL_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
-        g_warning("IPV6_DROP_MEMBERSHIP failed: %s\n", strerror(errno));
+        avahi_log_warn("IPV6_DROP_MEMBERSHIP failed: %s\n", strerror(errno));
         return -1;
     }
 
     return 0;
 }
 
-gint avahi_open_socket_ipv4(void) {
+static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
+    int yes;
+    
+    assert(fd >= 0);
+    assert(sa);
+    assert(l > 0);
+    
+    if (bind(fd, sa, l) < 0) {
+
+        if (errno != EADDRINUSE) {
+            avahi_log_warn("bind() failed: %s\n", strerror(errno));
+            return -1;
+        }
+            
+        avahi_log_warn("*** WARNING: Detected another %s mDNS stack running on this host. This makes mDNS unreliable and is thus not recommended. ***",
+                       sa->sa_family == AF_INET ? "IPv4" : "IPv6");
+
+        /* Try again, this time with SO_REUSEADDR set */
+        yes = 1;
+        if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
+            avahi_log_warn("SO_REUSEADDR failed: %s\n", strerror(errno));
+            return -1;
+        }
+
+        if (bind(fd, sa, l) < 0) {
+            avahi_log_warn("bind() failed: %s\n", strerror(errno));
+            return -1;
+        }
+    } else {
+
+        /* We enable SO_REUSEADDR afterwards, to make sure that the
+         * user may run other mDNS implementations if he really
+         * wants. */
+        
+        yes = 1;
+        if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
+            avahi_log_warn("SO_REUSEADDR failed: %s\n", strerror(errno));
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+int avahi_open_socket_ipv4(void) {
     struct sockaddr_in local;
     int fd = -1, ttl, yes;
         
     if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
-        g_warning("socket() failed: %s\n", strerror(errno));
+        avahi_log_warn("socket() failed: %s\n", strerror(errno));
         goto fail;
     }
     
     ttl = 255;
     if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
-        g_warning("IP_MULTICAST_TTL failed: %s\n", strerror(errno));
+        avahi_log_warn("IP_MULTICAST_TTL failed: %s\n", strerror(errno));
         goto fail;
     }
 
     ttl = 255;
     if (setsockopt(fd, SOL_IP, IP_TTL, &ttl, sizeof(ttl)) < 0) {
-        g_warning("IP_TTL failed: %s\n", strerror(errno));
+        avahi_log_warn("IP_TTL failed: %s\n", strerror(errno));
         goto fail;
     }
     
-    yes = 1;
-    if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
-        g_warning("SO_REUSEADDR failed: %s\n", strerror(errno));
-        goto fail;
-    }
-
     yes = 1;
     if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
-        g_warning("IP_MULTICAST_LOOP failed: %s\n", strerror(errno));
+        avahi_log_warn("IP_MULTICAST_LOOP failed: %s\n", strerror(errno));
         goto fail;
     }
-
     
     memset(&local, 0, sizeof(local));
     local.sin_family = AF_INET;
     local.sin_port = htons(AVAHI_MDNS_PORT);
-    
-    if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
-        g_warning("bind() failed: %s\n", strerror(errno));
+
+    if (bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local)) < 0)
         goto fail;
-    }
 
     yes = 1;
     if (setsockopt(fd, SOL_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
-        g_warning("IP_RECVTTL failed: %s\n", strerror(errno));
+        avahi_log_warn("IP_RECVTTL failed: %s\n", strerror(errno));
         goto fail;
     }
 
     yes = 1;
     if (setsockopt(fd, SOL_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0) {
-        g_warning("IP_PKTINFO failed: %s\n", strerror(errno));
+        avahi_log_warn("IP_PKTINFO failed: %s\n", strerror(errno));
         goto fail;
     }
     
     if (avahi_set_cloexec(fd) < 0) {
-        g_warning("FD_CLOEXEC failed: %s\n", strerror(errno));
+        avahi_log_warn("FD_CLOEXEC failed: %s\n", strerror(errno));
         goto fail;
     }
     
     if (avahi_set_nonblock(fd) < 0) {
-        g_warning("O_NONBLOCK failed: %s\n", strerror(errno));
+        avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno));
         goto fail;
     }
 
@@ -211,44 +263,38 @@ fail:
     return -1;
 }
 
-gint avahi_open_socket_ipv6(void) {
+int avahi_open_socket_ipv6(void) {
     struct sockaddr_in6 sa, local;
     int fd = -1, ttl, yes;
 
     mdns_mcast_group_ipv6(&sa);
         
     if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
-        g_warning("socket() failed: %s\n", strerror(errno));
+        avahi_log_warn("socket() failed: %s\n", strerror(errno));
         goto fail;
     }
     
     ttl = 255;
     if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
-        g_warning("IPV6_MULTICAST_HOPS failed: %s\n", strerror(errno));
+        avahi_log_warn("IPV6_MULTICAST_HOPS failed: %s\n", strerror(errno));
         goto fail;
     }
 
     ttl = 255;
     if (setsockopt(fd, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
-        g_warning("IPV6_UNICAST_HOPS failed: %s\n", strerror(errno));
+        avahi_log_warn("IPV6_UNICAST_HOPS failed: %s\n", strerror(errno));
         goto fail;
     }
     
-    yes = 1;
-    if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
-        g_warning("SO_REUSEADDR failed: %s\n", strerror(errno));
-        goto fail;
-    }
-
     yes = 1;
     if (setsockopt(fd, SOL_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) {
-        g_warning("IPV6_V6ONLY failed: %s\n", strerror(errno));
+        avahi_log_warn("IPV6_V6ONLY failed: %s\n", strerror(errno));
         goto fail;
     }
 
     yes = 1;
     if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
-        g_warning("IPV6_MULTICAST_LOOP failed: %s\n", strerror(errno));
+        avahi_log_warn("IPV6_MULTICAST_LOOP failed: %s\n", strerror(errno));
         goto fail;
     }
 
@@ -256,30 +302,28 @@ gint avahi_open_socket_ipv6(void) {
     local.sin6_family = AF_INET6;
     local.sin6_port = htons(AVAHI_MDNS_PORT);
     
-    if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
-        g_warning("bind() failed: %s\n", strerror(errno));
+    if (bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local)) < 0)
         goto fail;
-    }
 
     yes = 1;
     if (setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
-        g_warning("IPV6_HOPLIMIT failed: %s\n", strerror(errno));
+        avahi_log_warn("IPV6_HOPLIMIT failed: %s\n", strerror(errno));
         goto fail;
     }
 
     yes = 1;
     if (setsockopt(fd, SOL_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
-        g_warning("IPV6_PKTINFO failed: %s\n", strerror(errno));
+        avahi_log_warn("IPV6_PKTINFO failed: %s\n", strerror(errno));
         goto fail;
     }
     
     if (avahi_set_cloexec(fd) < 0) {
-        g_warning("FD_CLOEXEC failed: %s\n", strerror(errno));
+        avahi_log_warn("FD_CLOEXEC failed: %s\n", strerror(errno));
         goto fail;
     }
     
     if (avahi_set_nonblock(fd) < 0) {
-        g_warning("O_NONBLOCK failed: %s\n", strerror(errno));
+        avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno));
         goto fail;
     }
 
@@ -292,9 +336,9 @@ fail:
     return -1;
 }
 
-static gint sendmsg_loop(gint fd, struct msghdr *msg, gint flags) {
-    g_assert(fd >= 0);
-    g_assert(msg);
+static int sendmsg_loop(int fd, struct msghdr *msg, int flags) {
+    assert(fd >= 0);
+    assert(msg);
 
     for (;;) {
     
@@ -302,7 +346,7 @@ static gint sendmsg_loop(gint fd, struct msghdr *msg, gint flags) {
             break;
         
         if (errno != EAGAIN) {
-            g_message("sendmsg() failed: %s\n", strerror(errno));
+            avahi_log_debug("sendmsg() failed: %s\n", strerror(errno));
             return -1;
         }
         
@@ -313,7 +357,7 @@ static gint sendmsg_loop(gint fd, struct msghdr *msg, gint flags) {
     return 0;
 }
 
-gint avahi_send_dns_packet_ipv4(gint fd, gint interface, AvahiDnsPacket *p) {
+int avahi_send_dns_packet_ipv4(int fd, int interface, AvahiDnsPacket *p, const AvahiIPv4Address *a, uint16_t port) {
     struct sockaddr_in sa;
     struct msghdr msg;
     struct iovec io;
@@ -321,11 +365,15 @@ gint avahi_send_dns_packet_ipv4(gint fd, gint interface, AvahiDnsPacket *p) {
     struct in_pktinfo *pkti;
     uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in_pktinfo)];
 
-    g_assert(fd >= 0);
-    g_assert(p);
-    g_assert(avahi_dns_packet_check_valid(p) >= 0);
+    assert(fd >= 0);
+    assert(p);
+    assert(avahi_dns_packet_is_valid(p) >= 0);
+    assert(!a || port > 0);
 
-    mdns_mcast_group_ipv4(&sa);
+    if (!a)
+        mdns_mcast_group_ipv4(&sa);
+    else
+        ipv4_address_to_sockaddr(&sa, a, port);
 
     memset(&io, 0, sizeof(io));
     io.iov_base = AVAHI_DNS_PACKET_DATA(p);
@@ -349,10 +397,10 @@ gint avahi_send_dns_packet_ipv4(gint fd, gint interface, AvahiDnsPacket *p) {
     msg.msg_controllen = sizeof(cmsg_data);
     msg.msg_flags = 0;
 
-    return sendmsg_loop(fd, &msg, MSG_DONTROUTE);
+    return sendmsg_loop(fd, &msg, 0 /*MSG_DONTROUTE*/);
 }
 
-gint avahi_send_dns_packet_ipv6(gint fd, gint interface, AvahiDnsPacket *p) {
+int avahi_send_dns_packet_ipv6(int fd, int interface, AvahiDnsPacket *p, const AvahiIPv6Address *a, uint16_t port) {
     struct sockaddr_in6 sa;
     struct msghdr msg;
     struct iovec io;
@@ -360,11 +408,14 @@ gint avahi_send_dns_packet_ipv6(gint fd, gint interface, AvahiDnsPacket *p) {
     struct in6_pktinfo *pkti;
     uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in6_pktinfo)];
 
-    g_assert(fd >= 0);
-    g_assert(p);
-    g_assert(avahi_dns_packet_check_valid(p) >= 0);
+    assert(fd >= 0);
+    assert(p);
+    assert(avahi_dns_packet_is_valid(p) >= 0);
 
-    mdns_mcast_group_ipv6(&sa);
+    if (!a)
+        mdns_mcast_group_ipv6(&sa);
+    else
+        ipv6_address_to_sockaddr(&sa, a, port);
 
     memset(&io, 0, sizeof(io));
     io.iov_base = AVAHI_DNS_PACKET_DATA(p);
@@ -388,24 +439,31 @@ gint avahi_send_dns_packet_ipv6(gint fd, gint interface, AvahiDnsPacket *p) {
     msg.msg_controllen = sizeof(cmsg_data);
     msg.msg_flags = 0;
 
-    return sendmsg_loop(fd, &msg, MSG_DONTROUTE);
+    return sendmsg_loop(fd, &msg, 0 /*MSG_DONTROUTE*/);
 }
 
-AvahiDnsPacket* avahi_recv_dns_packet_ipv4(gint fd, struct sockaddr_in *ret_sa, gint *ret_iface, guint8* ret_ttl) {
+AvahiDnsPacket* avahi_recv_dns_packet_ipv4(int fd, struct sockaddr_in *ret_sa, AvahiIPv4Address *ret_dest_address, int *ret_iface, uint8_t* ret_ttl) {
     AvahiDnsPacket *p= NULL;
     struct msghdr msg;
     struct iovec io;
-    uint8_t aux[64];
+    uint8_t aux[1024];
     ssize_t l;
     struct cmsghdr *cmsg;
-    gboolean found_ttl = FALSE, found_iface = FALSE;
+    int found_ttl = 0, found_iface = 0;
+    int ms;
 
-    g_assert(fd >= 0);
-    g_assert(ret_sa);
-    g_assert(ret_iface);
-    g_assert(ret_ttl);
+    assert(fd >= 0);
+    assert(ret_sa);
+    assert(ret_dest_address);
+    assert(ret_iface);
+    assert(ret_ttl);
 
-    p = avahi_dns_packet_new(0);
+    if (ioctl(fd, FIONREAD, &ms) < 0) {
+        avahi_log_warn("ioctl(): %s", strerror(errno));
+        goto fail;
+    }
+
+    p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
 
     io.iov_base = AVAHI_DNS_PACKET_DATA(p);
     io.iov_len = p->max_size;
@@ -419,27 +477,48 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv4(gint fd, struct sockaddr_in *ret_sa,
     msg.msg_controllen = sizeof(aux);
     msg.msg_flags = 0;
     
-    if ((l = recvmsg(fd, &msg, 0)) < 0)
+    if ((l = recvmsg(fd, &msg, 0)) < 0) {
+        avahi_log_warn("recvmsg(): %s", strerror(errno));
         goto fail;
+    }
 
+    if (ret_sa->sin_addr.s_addr == INADDR_ANY) {
+        /* Linux 2.4 behaves very strangely sometimes! */
+
+        /*avahi_hexdump(AVAHI_DNS_PACKET_DATA(p), l); */
+        goto fail;
+    }
+    
+    assert(!(msg.msg_flags & MSG_CTRUNC));
+    assert(!(msg.msg_flags & MSG_TRUNC));
     p->size = (size_t) l;
     
     *ret_ttl = 0;
+
+/*     avahi_hexdump(msg.msg_control, msg.msg_controllen); */
         
-    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg,cmsg)) {
-        if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_TTL) {
-            *ret_ttl = *(uint8_t *) CMSG_DATA(cmsg);
-            found_ttl = TRUE;
-        }
+    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+
+/*         avahi_hexdump(CMSG_DATA(cmsg), cmsg->cmsg_len - sizeof(struct cmsghdr)); */
+        
+        if (cmsg->cmsg_level == SOL_IP) {
             
-        if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_PKTINFO) {
-            *ret_iface = ((struct in_pktinfo*) CMSG_DATA(cmsg))->ipi_ifindex;
-            found_iface = TRUE;
+            if (cmsg->cmsg_type == IP_TTL) {
+                *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
+                found_ttl = 1;
+            } else if (cmsg->cmsg_type == IP_PKTINFO) {
+                struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
+                *ret_iface = (int) i->ipi_ifindex;
+                ret_dest_address->address = i->ipi_addr.s_addr;
+                found_iface = 1;
+            }
         }
     }
 
-    g_assert(found_iface);
-    g_assert(found_ttl);
+/*     avahi_log_debug("ttl=%u iface=%i", *ret_ttl, *ret_iface); */
+
+    assert(found_iface);
+    assert(found_ttl);
 
     return p;
 
@@ -450,21 +529,29 @@ fail:
     return NULL;
 }
 
-AvahiDnsPacket* avahi_recv_dns_packet_ipv6(gint fd, struct sockaddr_in6 *ret_sa, gint *ret_iface, guint8* ret_ttl) {
+AvahiDnsPacket* avahi_recv_dns_packet_ipv6(int fd, struct sockaddr_in6 *ret_sa, AvahiIPv6Address *ret_dest_address, int *ret_iface, uint8_t* ret_ttl) {
     AvahiDnsPacket *p = NULL;
     struct msghdr msg;
     struct iovec io;
     uint8_t aux[64];
     ssize_t l;
+    int ms;
+    
     struct cmsghdr *cmsg;
-    gboolean found_ttl = FALSE, found_iface = FALSE;
+    int found_ttl = 0, found_iface = 0;
 
-    g_assert(fd >= 0);
-    g_assert(ret_sa);
-    g_assert(ret_iface);
-    g_assert(ret_ttl);
+    assert(fd >= 0);
+    assert(ret_sa);
+    assert(ret_dest_address);
+    assert(ret_iface);
+    assert(ret_ttl);
 
-    p = avahi_dns_packet_new(0);
+    if (ioctl(fd, FIONREAD, &ms) < 0) {
+        avahi_log_warn("ioctl(): %s", strerror(errno));
+        goto fail;
+    }
+    
+    p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
 
     io.iov_base = AVAHI_DNS_PACKET_DATA(p);
     io.iov_len = p->max_size;
@@ -478,8 +565,10 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv6(gint fd, struct sockaddr_in6 *ret_sa,
     msg.msg_controllen = sizeof(aux);
     msg.msg_flags = 0;
     
-    if ((l = recvmsg(fd, &msg, 0)) < 0)
+    if ((l = recvmsg(fd, &msg, 0)) < 0) {
+        avahi_log_warn("recvmsg(): %s", strerror(errno));
         goto fail;
+    }
 
     p->size = (size_t) l;
     
@@ -487,18 +576,20 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv6(gint fd, struct sockaddr_in6 *ret_sa,
 
     for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
         if (cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_HOPLIMIT) {
-            *ret_ttl = *(uint8_t *) CMSG_DATA(cmsg);
-            found_ttl = TRUE;
+            *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
+            found_ttl = 1;
         }
             
         if (cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
-            *ret_iface = ((struct in6_pktinfo*) CMSG_DATA(cmsg))->ipi6_ifindex;
-            found_iface = TRUE;
+            struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
+            *ret_iface = i->ipi6_ifindex;
+            memcpy(ret_dest_address->address, i->ipi6_addr.s6_addr, 16);
+            found_iface = 1;
         }
     }
 
-    g_assert(found_iface);
-    g_assert(found_ttl);
+    assert(found_iface);
+    assert(found_ttl);
 
     return p;
 
@@ -509,3 +600,98 @@ fail:
     return NULL;
 }
 
+int avahi_open_legacy_unicast_socket_ipv4(void) {
+    struct sockaddr_in local;
+    int fd = -1, yes;
+        
+    if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
+        avahi_log_warn("socket() failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    memset(&local, 0, sizeof(local));
+    local.sin_family = AF_INET;
+    
+    if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
+        avahi_log_warn("bind() failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    yes = 1;
+    if (setsockopt(fd, SOL_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IP_RECVTTL failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    yes = 1;
+    if (setsockopt(fd, SOL_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IP_PKTINFO failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    if (avahi_set_cloexec(fd) < 0) {
+        avahi_log_warn("FD_CLOEXEC failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    if (avahi_set_nonblock(fd) < 0) {
+        avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    return fd;
+
+fail:
+    if (fd >= 0)
+        close(fd);
+
+    return -1;
+}
+
+int avahi_open_legacy_unicast_socket_ipv6(void) {
+    struct sockaddr_in local;
+    int fd = -1, yes;
+        
+    if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
+        avahi_log_warn("socket() failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    memset(&local, 0, sizeof(local));
+    local.sin_family = AF_INET;
+    
+    if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
+        avahi_log_warn("bind() failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    yes = 1;
+    if (setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IPV6_HOPLIMIT failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    yes = 1;
+    if (setsockopt(fd, SOL_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IPV6_PKTINFO failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    if (avahi_set_cloexec(fd) < 0) {
+        avahi_log_warn("FD_CLOEXEC failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    if (avahi_set_nonblock(fd) < 0) {
+        avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    return fd;
+
+fail:
+    if (fd >= 0)
+        close(fd);
+
+    return -1;
+}