X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-core%2Fsocket.c;h=ef421c9f2218ce944cb882d856f3da2f97374db6;hb=8b39fbe45e2dd0dec1b6e460cdb3abef25ad168a;hp=91cbf40a0962276b67b5dd9b43812c0aaabc1b9e;hpb=907bf2598220828a50b22cc00395524bb74feb8e;p=catta

diff --git a/avahi-core/socket.c b/avahi-core/socket.c
index 91cbf40..ef421c9 100644
--- a/avahi-core/socket.c
+++ b/avahi-core/socket.c
@@ -37,11 +37,28 @@
 #include <sys/ioctl.h>
 #include <assert.h>
 
+#ifdef IP_RECVIF
+#include <net/if_dl.h>
+#endif
+
 #include "dns.h"
 #include "fdutil.h"
 #include "socket.h"
 #include "log.h"
 
+/* this is a portability hack */
+#ifndef IPV6_ADD_MEMBERSHIP
+#ifdef  IPV6_JOIN_GROUP
+#define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
+#endif
+#endif
+
+#ifndef IPV6_DROP_MEMBERSHIP
+#ifdef  IPV6_LEAVE_GROUP
+#define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP
+#endif
+#endif
+
 static void mdns_mcast_group_ipv4(struct sockaddr_in *ret_sa) {
     assert(ret_sa);
 
@@ -82,25 +99,37 @@ static void ipv6_address_to_sockaddr(struct sockaddr_in6 *ret_sa, const AvahiIPv
     memcpy(&ret_sa->sin6_addr, a, sizeof(AvahiIPv6Address));
 }
 
-int avahi_mdns_mcast_join_ipv4(int fd, int idx) {
-    struct ip_mreqn mreq; 
+#ifdef HAVE_STRUCT_IP_MREQN
+int avahi_mdns_mcast_join_ipv4(int fd, int idx, int join) {
+    struct ip_mreqn mreq;
+#else
+int avahi_mdns_mcast_join_ipv4(int fd, const AvahiAddress *a, int join) {
+    struct ip_mreq mreq;
+#endif
+        
     struct sockaddr_in sa;
-
-    mdns_mcast_group_ipv4 (&sa);
- 
     memset(&mreq, 0, sizeof(mreq));
-    mreq.imr_multiaddr = sa.sin_addr;
+
+#ifdef HAVE_STRUCT_IP_MREQN
     mreq.imr_ifindex = idx;
- 
-    if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
-        avahi_log_warn("IP_ADD_MEMBERSHIP failed: %s\n", strerror(errno));
+#else
+    assert(a);
+    assert(a->proto == AVAHI_PROTO_INET);
+    mreq.imr_interface.s_addr = a->data.ipv4.address;
+#endif
+    
+    mdns_mcast_group_ipv4(&sa);
+    mreq.imr_multiaddr = sa.sin_addr;
+
+    if (setsockopt(fd, IPPROTO_IP, join ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
+        avahi_log_warn("%s failed: %s", join ? "IP_ADD_MEMBERSHIP" : "IP_DROP_MEMBERSHIP", strerror(errno));
         return -1;
     } 
 
     return 0;
 }
 
-int avahi_mdns_mcast_join_ipv6(int fd, int idx) {
+int avahi_mdns_mcast_join_ipv6(int fd, int idx, int join) {
     struct ipv6_mreq mreq6; 
     struct sockaddr_in6 sa6;
 
@@ -110,52 +139,35 @@ int avahi_mdns_mcast_join_ipv6(int fd, int idx) {
     mreq6.ipv6mr_multiaddr = sa6.sin6_addr;
     mreq6.ipv6mr_interface = idx;
 
-    if (setsockopt(fd, SOL_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
-        avahi_log_warn("IPV6_ADD_MEMBERSHIP failed: %s\n", strerror(errno));
+    if (setsockopt(fd, IPPROTO_IPV6, join ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
+        avahi_log_warn("%s failed: %s", join ? "IPV6_ADD_MEMBERSHIP" : "IPV6_DROP_MEMBERSHIP", strerror(errno));
         return -1;
     }
 
     return 0;
 }
 
-int avahi_mdns_mcast_leave_ipv4(int fd, int idx) {
-    struct ip_mreqn mreq; 
-    struct sockaddr_in sa;
+static int reuseaddr(int fd) {
+    int yes;
     
-    mdns_mcast_group_ipv4 (&sa);
- 
-    memset(&mreq, 0, sizeof(mreq));
-    mreq.imr_multiaddr = sa.sin_addr;
-    mreq.imr_ifindex = idx;
- 
-    if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
-        avahi_log_warn("IP_DROP_MEMBERSHIP failed: %s\n", strerror(errno));
+    yes = 1;
+    if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("SO_REUSEADDR failed: %s", strerror(errno));
         return -1;
     }
-
-    return 0;
-}
-
-int avahi_mdns_mcast_leave_ipv6(int fd, int idx) {
-    struct ipv6_mreq mreq6; 
-    struct sockaddr_in6 sa6;
-
-    mdns_mcast_group_ipv6 (&sa6);
-
-    memset(&mreq6, 0, sizeof(mreq6));
-    mreq6.ipv6mr_multiaddr = sa6.sin6_addr;
-    mreq6.ipv6mr_interface = idx;
-
-    if (setsockopt(fd, SOL_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
-        avahi_log_warn("IPV6_DROP_MEMBERSHIP failed: %s\n", strerror(errno));
+    
+#ifdef SO_REUSEPORT
+    yes = 1;
+    if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("SO_REUSEPORT failed: %s", strerror(errno));
         return -1;
     }
-
+#endif
+    
     return 0;
 }
 
 static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
-    int yes;
     
     assert(fd >= 0);
     assert(sa);
@@ -164,7 +176,7 @@ static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
     if (bind(fd, sa, l) < 0) {
 
         if (errno != EADDRINUSE) {
-            avahi_log_warn("bind() failed: %s\n", strerror(errno));
+            avahi_log_warn("bind() failed: %s", strerror(errno));
             return -1;
         }
             
@@ -172,14 +184,11 @@ static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
                        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));
+        if (reuseaddr(fd) < 0)
             return -1;
-        }
-
+        
         if (bind(fd, sa, l) < 0) {
-            avahi_log_warn("bind() failed: %s\n", strerror(errno));
+            avahi_log_warn("bind() failed: %s", strerror(errno));
             return -1;
         }
     } else {
@@ -188,40 +197,124 @@ static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
          * 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));
+        if (reuseaddr(fd) < 0)
             return -1;
-        }
     }
 
     return 0;
 }
 
-int avahi_open_socket_ipv4(void) {
+static int ipv4_pktinfo(int fd) {
+    int yes;
+    
+#ifdef IP_PKTINFO
+    yes = 1;
+    if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IP_PKTINFO failed: %s", strerror(errno));
+        return -1;
+    }
+#else
+    
+#ifdef IP_RECVINTERFACE
+    yes = 1;
+    if (setsockopt (fd, IPPROTO_IP, IP_RECVINTERFACE, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IP_RECVINTERFACE failed: %s", strerror(errno));
+        return -1;
+    }
+#elif defined(IP_RECVIF)
+    yes = 1;
+    if (setsockopt (fd, IPPROTO_IP, IP_RECVIF, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IP_RECVIF failed: %s", strerror(errno));
+        return -1;
+    }
+#endif
+    
+#ifdef IP_RECVDSTADDR
+    yes = 1;
+    if (setsockopt (fd, IPPROTO_IP, IP_RECVDSTADDR, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IP_RECVDSTADDR failed: %s", strerror(errno));
+        return -1;
+    }
+#endif
+    
+#endif /* IP_PKTINFO */
+
+#ifdef IP_RECVTTL
+    yes = 1;
+    if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IP_RECVTTL failed: %s", strerror(errno));
+        return -1;
+    }
+#endif
+
+    return 0;
+}
+
+static int ipv6_pktinfo(int fd) {
+    int yes;
+    
+#ifdef IPV6_RECVPKTINFO
+    yes = 1;
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IPV6_RECVPKTINFO failed: %s", strerror(errno));
+        return -1;
+    }
+#elif defined(IPV6_PKTINFO)
+    yes = 1;
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IPV6_PKTINFO failed: %s", strerror(errno));
+        return -1;
+    }
+#endif
+
+#ifdef IPV6_RECVHOPS
+    yes = 1;
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPS, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IPV6_RECVHOPS failed: %s", strerror(errno));
+        return -1;
+    }
+#elif defined(IPV6_RECVHOPLIMIT)
+    yes = 1;
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IPV6_RECVHOPLIMIT failed: %s", strerror(errno));
+        return -1;
+    }
+#elif defined(IPV6_HOPLIMIT)
+    yes = 1;
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IPV6_HOPLIMIT failed: %s", strerror(errno));
+        return -1;
+    }
+#endif
+
+    return 0;
+}
+
+int avahi_open_socket_ipv4(int no_reuse) {
     struct sockaddr_in local;
-    int fd = -1, ttl, yes;
+    int fd = -1, r, ittl;
+    uint8_t ttl, cyes;
         
     if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
-        avahi_log_warn("socket() failed: %s\n", strerror(errno));
+        avahi_log_warn("socket() failed: %s", strerror(errno));
         goto fail;
     }
     
     ttl = 255;
-    if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
-        avahi_log_warn("IP_MULTICAST_TTL failed: %s\n", strerror(errno));
+    if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
+        avahi_log_warn("IP_MULTICAST_TTL failed: %s", strerror(errno));
         goto fail;
     }
 
-    ttl = 255;
-    if (setsockopt(fd, SOL_IP, IP_TTL, &ttl, sizeof(ttl)) < 0) {
-        avahi_log_warn("IP_TTL failed: %s\n", strerror(errno));
+    ittl = 255;
+    if (setsockopt(fd, IPPROTO_IP, IP_TTL, &ittl, sizeof(ittl)) < 0) {
+        avahi_log_warn("IP_TTL failed: %s", strerror(errno));
         goto fail;
     }
     
-    yes = 1;
-    if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
-        avahi_log_warn("IP_MULTICAST_LOOP failed: %s\n", strerror(errno));
+    cyes = 1;
+    if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &cyes, sizeof(cyes)) < 0) {
+        avahi_log_warn("IP_MULTICAST_LOOP failed: %s", strerror(errno));
         goto fail;
     }
     
@@ -229,28 +322,24 @@ int avahi_open_socket_ipv4(void) {
     local.sin_family = AF_INET;
     local.sin_port = htons(AVAHI_MDNS_PORT);
 
-    if (bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local)) < 0)
-        goto fail;
+    if (no_reuse)
+        r = bind(fd, (struct sockaddr*) &local, sizeof(local));
+    else
+        r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
 
-    yes = 1;
-    if (setsockopt(fd, SOL_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
-        avahi_log_warn("IP_RECVTTL failed: %s\n", strerror(errno));
+    if (r < 0)
         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 (ipv4_pktinfo (fd) < 0)
+         goto fail;
+
     if (avahi_set_cloexec(fd) < 0) {
-        avahi_log_warn("FD_CLOEXEC failed: %s\n", strerror(errno));
+        avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
         goto fail;
     }
     
     if (avahi_set_nonblock(fd) < 0) {
-        avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno));
+        avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
         goto fail;
     }
 
@@ -263,38 +352,39 @@ fail:
     return -1;
 }
 
-int avahi_open_socket_ipv6(void) {
+int avahi_open_socket_ipv6(int no_reuse) {
     struct sockaddr_in6 sa, local;
-    int fd = -1, ttl, yes;
+    int fd = -1, yes, r;
+    int ttl;
 
     mdns_mcast_group_ipv6(&sa);
         
     if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
-        avahi_log_warn("socket() failed: %s\n", strerror(errno));
+        avahi_log_warn("socket() failed: %s", strerror(errno));
         goto fail;
     }
     
     ttl = 255;
-    if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
-        avahi_log_warn("IPV6_MULTICAST_HOPS failed: %s\n", strerror(errno));
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
+        avahi_log_warn("IPV6_MULTICAST_HOPS failed: %s", strerror(errno));
         goto fail;
     }
 
     ttl = 255;
-    if (setsockopt(fd, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
-        avahi_log_warn("IPV6_UNICAST_HOPS failed: %s\n", strerror(errno));
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
+        avahi_log_warn("IPV6_UNICAST_HOPS failed: %s", strerror(errno));
         goto fail;
     }
     
     yes = 1;
-    if (setsockopt(fd, SOL_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) {
-        avahi_log_warn("IPV6_V6ONLY failed: %s\n", strerror(errno));
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IPV6_V6ONLY failed: %s", strerror(errno));
         goto fail;
     }
 
     yes = 1;
-    if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
-        avahi_log_warn("IPV6_MULTICAST_LOOP failed: %s\n", strerror(errno));
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
+        avahi_log_warn("IPV6_MULTICAST_LOOP failed: %s", strerror(errno));
         goto fail;
     }
 
@@ -302,28 +392,24 @@ int avahi_open_socket_ipv6(void) {
     local.sin6_family = AF_INET6;
     local.sin6_port = htons(AVAHI_MDNS_PORT);
     
-    if (bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local)) < 0)
-        goto fail;
+    if (no_reuse)
+        r = bind(fd, (struct sockaddr*) &local, sizeof(local));
+    else
+        r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
 
-    yes = 1;
-    if (setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
-        avahi_log_warn("IPV6_HOPLIMIT failed: %s\n", strerror(errno));
+    if (r < 0)
         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));
+    if (ipv6_pktinfo(fd) < 0)
         goto fail;
-    }
     
     if (avahi_set_cloexec(fd) < 0) {
-        avahi_log_warn("FD_CLOEXEC failed: %s\n", strerror(errno));
+        avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
         goto fail;
     }
     
     if (avahi_set_nonblock(fd) < 0) {
-        avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno));
+        avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
         goto fail;
     }
 
@@ -346,7 +432,7 @@ static int sendmsg_loop(int fd, struct msghdr *msg, int flags) {
             break;
         
         if (errno != EAGAIN) {
-            avahi_log_debug("sendmsg() failed: %s\n", strerror(errno));
+            avahi_log_debug("sendmsg() failed: %s", strerror(errno));
             return -1;
         }
         
@@ -361,13 +447,14 @@ int avahi_send_dns_packet_ipv4(int fd, int interface, AvahiDnsPacket *p, const A
     struct sockaddr_in sa;
     struct msghdr msg;
     struct iovec io;
+#ifdef IP_PKTINFO
     struct cmsghdr *cmsg;
-    struct in_pktinfo *pkti;
     uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in_pktinfo)];
+#endif
 
     assert(fd >= 0);
     assert(p);
-    assert(avahi_dns_packet_is_valid(p) >= 0);
+    assert(avahi_dns_packet_check_valid(p) >= 0);
     assert(!a || port > 0);
 
     if (!a)
@@ -379,24 +466,36 @@ int avahi_send_dns_packet_ipv4(int fd, int interface, AvahiDnsPacket *p, const A
     io.iov_base = AVAHI_DNS_PACKET_DATA(p);
     io.iov_len = p->size;
 
-    memset(cmsg_data, 0, sizeof(cmsg_data));
-    cmsg = (struct cmsghdr*) cmsg_data;
-    cmsg->cmsg_len = sizeof(cmsg_data);
-    cmsg->cmsg_level = IPPROTO_IP;
-    cmsg->cmsg_type = IP_PKTINFO;
-
-    pkti = (struct in_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
-    pkti->ipi_ifindex = interface;
-    
     memset(&msg, 0, sizeof(msg));
     msg.msg_name = &sa;
     msg.msg_namelen = sizeof(sa);
     msg.msg_iov = &io;
     msg.msg_iovlen = 1;
-    msg.msg_control = cmsg_data;
-    msg.msg_controllen = sizeof(cmsg_data);
     msg.msg_flags = 0;
+    msg.msg_control = NULL;
+    msg.msg_controllen = 0;
+
+#ifdef IP_PKTINFO
+    if (interface >= 0) {
+        struct in_pktinfo *pkti;
+        
+        memset(cmsg_data, 0, sizeof(cmsg_data));
+        cmsg = (struct cmsghdr*) cmsg_data;
+        cmsg->cmsg_len = sizeof(cmsg_data);
+        cmsg->cmsg_level = IPPROTO_IP;
+        cmsg->cmsg_type = IP_PKTINFO;
+
+        pkti = (struct in_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
+        pkti->ipi_ifindex = interface;
+
+        msg.msg_control = cmsg_data;
+        msg.msg_controllen = sizeof(cmsg_data);
+    }
+#endif
 
+    /** FIXME: We need some code to set the outgoing interface here if
+     * IP_PKTINFO is not available */
+    
     return sendmsg_loop(fd, &msg, 0);
 }
 
@@ -405,12 +504,11 @@ int avahi_send_dns_packet_ipv6(int fd, int interface, AvahiDnsPacket *p, const A
     struct msghdr msg;
     struct iovec io;
     struct cmsghdr *cmsg;
-    struct in6_pktinfo *pkti;
     uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in6_pktinfo)];
 
     assert(fd >= 0);
     assert(p);
-    assert(avahi_dns_packet_is_valid(p) >= 0);
+    assert(avahi_dns_packet_check_valid(p) >= 0);
 
     if (!a)
         mdns_mcast_group_ipv6(&sa);
@@ -421,25 +519,34 @@ int avahi_send_dns_packet_ipv6(int fd, int interface, AvahiDnsPacket *p, const A
     io.iov_base = AVAHI_DNS_PACKET_DATA(p);
     io.iov_len = p->size;
 
-    memset(cmsg_data, 0, sizeof(cmsg_data));
-    cmsg = (struct cmsghdr*) cmsg_data;
-    cmsg->cmsg_len = sizeof(cmsg_data);
-    cmsg->cmsg_level = IPPROTO_IPV6;
-    cmsg->cmsg_type = IPV6_PKTINFO;
-
-    pkti = (struct in6_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
-    pkti->ipi6_ifindex = interface;
     
     memset(&msg, 0, sizeof(msg));
     msg.msg_name = &sa;
     msg.msg_namelen = sizeof(sa);
     msg.msg_iov = &io;
     msg.msg_iovlen = 1;
-    msg.msg_control = cmsg_data;
-    msg.msg_controllen = sizeof(cmsg_data);
     msg.msg_flags = 0;
 
-    return sendmsg_loop(fd, &msg, 0 /*MSG_DONTROUTE*/);
+    if (interface >= 0) {
+        struct in6_pktinfo *pkti;
+    
+        memset(cmsg_data, 0, sizeof(cmsg_data));
+        cmsg = (struct cmsghdr*) cmsg_data;
+        cmsg->cmsg_len = sizeof(cmsg_data);
+        cmsg->cmsg_level = IPPROTO_IPV6;
+        cmsg->cmsg_type = IPV6_PKTINFO;
+        
+        pkti = (struct in6_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
+        pkti->ipi6_ifindex = interface;
+        
+        msg.msg_control = cmsg_data;
+        msg.msg_controllen = sizeof(cmsg_data);
+    } else {
+        msg.msg_control = NULL;
+        msg.msg_controllen = 0;
+    }
+    
+    return sendmsg_loop(fd, &msg, 0);
 }
 
 AvahiDnsPacket* avahi_recv_dns_packet_ipv4(int fd, struct sockaddr_in *ret_sa, AvahiIPv4Address *ret_dest_address, int *ret_iface, uint8_t* ret_ttl) {
@@ -449,14 +556,10 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv4(int fd, struct sockaddr_in *ret_sa, A
     uint8_t aux[1024];
     ssize_t l;
     struct cmsghdr *cmsg;
-    int found_ttl = 0, found_iface = 0;
+    int found_iface = 0, found_addr = 0;
     int ms;
 
     assert(fd >= 0);
-    assert(ret_sa);
-    assert(ret_dest_address);
-    assert(ret_iface);
-    assert(ret_ttl);
 
     if (ioctl(fd, FIONREAD, &ms) < 0) {
         avahi_log_warn("ioctl(): %s", strerror(errno));
@@ -469,8 +572,13 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv4(int fd, struct sockaddr_in *ret_sa, A
     io.iov_len = p->max_size;
     
     memset(&msg, 0, sizeof(msg));
-    msg.msg_name = ret_sa;
-    msg.msg_namelen = sizeof(struct sockaddr_in);
+    if (ret_sa) {
+        msg.msg_name = ret_sa;
+        msg.msg_namelen = sizeof(struct sockaddr_in);
+    } else {
+        msg.msg_name = NULL;
+        msg.msg_namelen = 0;
+    }
     msg.msg_iov = &io;
     msg.msg_iovlen = 1;
     msg.msg_control = aux;
@@ -482,7 +590,7 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv4(int fd, struct sockaddr_in *ret_sa, A
         goto fail;
     }
 
-    if (ret_sa->sin_addr.s_addr == INADDR_ANY) {
+    if (ret_sa && ret_sa->sin_addr.s_addr == INADDR_ANY) {
         /* Linux 2.4 behaves very strangely sometimes! */
 
         /*avahi_hexdump(AVAHI_DNS_PACKET_DATA(p), l); */
@@ -492,33 +600,67 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv4(int fd, struct sockaddr_in *ret_sa, A
     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); */
-        
+    if (ret_ttl)
+        *ret_ttl = 255;
+    
     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 == IPPROTO_IP) {
+            switch (cmsg->cmsg_type) {
+#ifdef IP_RECVTTL
+                case IP_RECVTTL:
+#endif
+                case IP_TTL:
+                    if (ret_ttl)
+                        *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
+
+                    break;
+
+#ifdef IP_PKTINFO
+                case IP_PKTINFO: {
+                    struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
+                    
+                    if (ret_iface)
+                        *ret_iface = (int) i->ipi_ifindex;
+                    
+                    if (ret_dest_address)
+                        ret_dest_address->address = i->ipi_addr.s_addr;
+                    
+                    found_addr = found_iface = 1;
+
+                    break;
+                }
+#elif defined(IP_RECVIF)
+                case IP_RECVIF: {
+                    struct sockaddr_dl *sdl = (struct sockaddr_dl *) CMSG_DATA (cmsg);
+                    
+                    if (ret_iface)
+                        *ret_iface = (int) sdl->sdl_index;
+                    
+                    found_iface = 1;
+                    break;
+                }
+#endif
             
-            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;
+#ifdef IP_RECVDSTADDR
+                case IP_RECVDSTADDR:
+                    if (ret_dest_address)
+                        memcpy(&ret_dest_address->address, CMSG_DATA (cmsg), 4);
+                    found_addr = 1;
+                    break;
+                    
+#endif
+                    
+                default:
+                    avahi_log_warn("Unhandled cmsg_type : %d", cmsg->cmsg_type);
+                    break;
             }
         }
     }
 
-/*     avahi_log_debug("ttl=%u iface=%i", *ret_ttl, *ret_iface); */
-
     assert(found_iface);
-    assert(found_ttl);
+    assert(found_addr);
 
     return p;
 
@@ -541,10 +683,6 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv6(int fd, struct sockaddr_in6 *ret_sa,
     int found_ttl = 0, found_iface = 0;
 
     assert(fd >= 0);
-    assert(ret_sa);
-    assert(ret_dest_address);
-    assert(ret_iface);
-    assert(ret_ttl);
 
     if (ioctl(fd, FIONREAD, &ms) < 0) {
         avahi_log_warn("ioctl(): %s", strerror(errno));
@@ -557,8 +695,14 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv6(int fd, struct sockaddr_in6 *ret_sa,
     io.iov_len = p->max_size;
     
     memset(&msg, 0, sizeof(msg));
-    msg.msg_name = ret_sa;
-    msg.msg_namelen = sizeof(struct sockaddr_in6);
+    if (ret_sa) {
+        msg.msg_name = ret_sa;
+        msg.msg_namelen = sizeof(struct sockaddr_in6);
+    } else {
+        msg.msg_name = NULL;
+        msg.msg_namelen = 0;
+    }
+    
     msg.msg_iov = &io;
     msg.msg_iovlen = 1;
     msg.msg_control = aux;
@@ -571,19 +715,28 @@ AvahiDnsPacket* avahi_recv_dns_packet_ipv6(int fd, struct sockaddr_in6 *ret_sa,
     }
 
     p->size = (size_t) l;
-    
-    *ret_ttl = 0;
+
+    if (ret_ttl)
+        *ret_ttl = 0;
 
     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) (*(int *) CMSG_DATA(cmsg));
+        if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_HOPLIMIT) {
+
+            if (ret_ttl)
+                *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
+            
             found_ttl = 1;
         }
             
-        if (cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
+        if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
             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);
+
+            if (ret_iface)
+                *ret_iface = i->ipi6_ifindex;
+
+            if (ret_dest_address)
+                memcpy(ret_dest_address->address, i->ipi6_addr.s6_addr, 16);
+            
             found_iface = 1;
         }
     }
@@ -600,12 +753,12 @@ fail:
     return NULL;
 }
 
-int avahi_open_legacy_unicast_socket_ipv4(void) {
+int avahi_open_unicast_socket_ipv4(void) {
     struct sockaddr_in local;
-    int fd = -1, yes;
+    int fd = -1;
         
     if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
-        avahi_log_warn("socket() failed: %s\n", strerror(errno));
+        avahi_log_warn("socket() failed: %s", strerror(errno));
         goto fail;
     }
     
@@ -613,29 +766,21 @@ int avahi_open_legacy_unicast_socket_ipv4(void) {
     local.sin_family = AF_INET;
     
     if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
-        avahi_log_warn("bind() failed: %s\n", strerror(errno));
+        avahi_log_warn("bind() failed: %s", 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;
+    if (ipv4_pktinfo(fd) < 0) {
+         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));
+        avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
         goto fail;
     }
     
     if (avahi_set_nonblock(fd) < 0) {
-        avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno));
+        avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
         goto fail;
     }
 
@@ -648,42 +793,33 @@ fail:
     return -1;
 }
 
-int avahi_open_legacy_unicast_socket_ipv6(void) {
-    struct sockaddr_in local;
-    int fd = -1, yes;
+int avahi_open_unicast_socket_ipv6(void) {
+    struct sockaddr_in6 local;
+    int fd = -1;
         
     if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
-        avahi_log_warn("socket() failed: %s\n", strerror(errno));
+        avahi_log_warn("socket() failed: %s", strerror(errno));
         goto fail;
     }
     
     memset(&local, 0, sizeof(local));
-    local.sin_family = AF_INET;
+    local.sin6_family = AF_INET6;
     
     if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
-        avahi_log_warn("bind() failed: %s\n", strerror(errno));
+        avahi_log_warn("bind() failed: %s", 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));
+    if (ipv6_pktinfo(fd) < 0)
         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));
+        avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
         goto fail;
     }
     
     if (avahi_set_nonblock(fd) < 0) {
-        avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno));
+        avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
         goto fail;
     }