* add option to not enable SO_REUSEADDR for multicast sockets, effectively disallow multiple mDNS stacks running simultaneously

* add a config file option for this and enable it by default
* remove some bad \n in log messages


git-svn-id: file:///home/lennart/svn/public/avahi/trunk@646 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe

7 files changed, 65 insertions, 50 deletions

diff --git a/avahi-core/core.h b/avahi-core/core.h
index 705fa31..4883c6b 100644
--- a/avahi-core/core.h
+++ b/avahi-core/core.h
@@ -80,6 +80,7 @@ typedef struct AvahiServerConfig {
     int enable_wide_area;             /**< Enable wide area support */
     AvahiAddress wide_area_servers[AVAHI_MAX_WIDE_AREA_SERVERS]; /** Unicast DNS server to use for wide area lookup */
     unsigned n_wide_area_servers;     /**< Number of servers in wide_area_servers[] */
+    int disallow_other_stacks;        /**< Make sure that only one mDNS responder is run at the same time on the local machine. If this is enable Avahi will not set SO_REUSADDR on its sockets, effectively preventing other stacks from running on the local machine */
 } AvahiServerConfig;
 
 /** Allocate a new mDNS responder object. */
diff --git a/avahi-core/server.c b/avahi-core/server.c
index c4545c6..6b7571e 100644
--- a/avahi-core/server.c
+++ b/avahi-core/server.c
@@ -1324,8 +1324,8 @@ static int valid_server_config(const AvahiServerConfig *sc) {
 static int setup_sockets(AvahiServer *s) {
     assert(s);
     
-    s->fd_ipv4 = s->config.use_ipv4 ? avahi_open_socket_ipv4() : -1;
-    s->fd_ipv6 = s->config.use_ipv6 ? avahi_open_socket_ipv6() : -1;
+    s->fd_ipv4 = s->config.use_ipv4 ? avahi_open_socket_ipv4(s->config.disallow_other_stacks) : -1;
+    s->fd_ipv6 = s->config.use_ipv6 ? avahi_open_socket_ipv6(s->config.disallow_other_stacks) : -1;
     
     if (s->fd_ipv6 < 0 && s->fd_ipv4 < 0)
         return AVAHI_ERR_NO_NETWORK;
@@ -2446,6 +2446,7 @@ AvahiServerConfig* avahi_server_config_init(AvahiServerConfig *c) {
     c->add_service_cookie = 1;
     c->enable_wide_area = 0;
     c->n_wide_area_servers = 0;
+    c->disallow_other_stacks = 0;
     
     return c;
 }
diff --git a/avahi-core/socket.c b/avahi-core/socket.c
index ecc137b..0323b37 100644
--- a/avahi-core/socket.c
+++ b/avahi-core/socket.c
@@ -93,7 +93,7 @@ int avahi_mdns_mcast_join_ipv4(int fd, int idx) {
     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));
+        avahi_log_warn("IP_ADD_MEMBERSHIP failed: %s", strerror(errno));
         return -1;
     } 
 
@@ -111,7 +111,7 @@ int avahi_mdns_mcast_join_ipv6(int fd, int idx) {
     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));
+        avahi_log_warn("IPV6_ADD_MEMBERSHIP failed: %s", strerror(errno));
         return -1;
     }
 
@@ -129,7 +129,7 @@ int avahi_mdns_mcast_leave_ipv4(int fd, int idx) {
     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));
+        avahi_log_warn("IP_DROP_MEMBERSHIP failed: %s", strerror(errno));
         return -1;
     }
 
@@ -147,7 +147,7 @@ int avahi_mdns_mcast_leave_ipv6(int fd, int idx) {
     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));
+        avahi_log_warn("IPV6_DROP_MEMBERSHIP failed: %s", strerror(errno));
         return -1;
     }
 
@@ -164,7 +164,7 @@ 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;
         }
             
@@ -174,12 +174,12 @@ static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
         /* 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));
+            avahi_log_warn("SO_REUSEADDR failed: %s", strerror(errno));
             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 {
@@ -190,7 +190,7 @@ static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
         
         yes = 1;
         if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
-            avahi_log_warn("SO_REUSEADDR failed: %s\n", strerror(errno));
+            avahi_log_warn("SO_REUSEADDR failed: %s", strerror(errno));
             return -1;
         }
     }
@@ -198,30 +198,30 @@ static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
     return 0;
 }
 
-int avahi_open_socket_ipv4(void) {
+int avahi_open_socket_ipv4(int no_reuse) {
     struct sockaddr_in local;
-    int fd = -1, ttl, yes;
+    int fd = -1, ttl, yes, r;
         
     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));
+        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));
+        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));
+        avahi_log_warn("IP_MULTICAST_LOOP failed: %s", strerror(errno));
         goto fail;
     }
     
@@ -229,28 +229,33 @@ 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)
+    if (no_reuse)
+        r = bind(fd, (struct sockaddr*) &local, sizeof(local));
+    else
+        r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
+
+    if (r < 0)
         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));
+        avahi_log_warn("IP_RECVTTL failed: %s", 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));
+        avahi_log_warn("IP_PKTINFO failed: %s", 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;
     }
 
@@ -263,38 +268,38 @@ 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, ttl, yes, r;
 
     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));
+        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));
+        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));
+        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));
+        avahi_log_warn("IPV6_MULTICAST_LOOP failed: %s", strerror(errno));
         goto fail;
     }
 
@@ -302,28 +307,33 @@ 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)
+    if (no_reuse)
+        r = bind(fd, (struct sockaddr*) &local, sizeof(local));
+    else
+        r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
+
+    if (r < 0)
         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));
+        avahi_log_warn("IPV6_HOPLIMIT failed: %s", 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));
+        avahi_log_warn("IPV6_PKTINFO failed: %s", 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;
     }
 
@@ -346,7 +356,7 @@ 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;
         }
         
@@ -631,7 +641,7 @@ int avahi_open_unicast_socket_ipv4(void) {
     int fd = -1, yes;
         
     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;
     }
     
@@ -639,29 +649,29 @@ int avahi_open_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));
+        avahi_log_warn("IP_RECVTTL failed: %s", 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));
+        avahi_log_warn("IP_PKTINFO failed: %s", 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;
     }
 
@@ -679,7 +689,7 @@ int avahi_open_unicast_socket_ipv6(void) {
     int fd = -1, yes;
         
     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;
     }
     
@@ -687,29 +697,29 @@ int avahi_open_unicast_socket_ipv6(void) {
     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));
+        avahi_log_warn("IPV6_HOPLIMIT failed: %s", 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));
+        avahi_log_warn("IPV6_PKTINFO failed: %s", 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;
     }
 
diff --git a/avahi-core/socket.h b/avahi-core/socket.h
index 971e7e8..caf7066 100644
--- a/avahi-core/socket.h
+++ b/avahi-core/socket.h
@@ -32,8 +32,8 @@
 #define AVAHI_IPV4_MCAST_GROUP "224.0.0.251"
 #define AVAHI_IPV6_MCAST_GROUP "ff02::fb"
 
-int avahi_open_socket_ipv4(void);
-int avahi_open_socket_ipv6(void);
+int avahi_open_socket_ipv4(int no_reuse);
+int avahi_open_socket_ipv6(int no_reuse);
 
 int avahi_open_unicast_socket_ipv4(void);
 int avahi_open_unicast_socket_ipv6(void);
diff --git a/avahi-daemon/avahi-daemon.conf b/avahi-daemon/avahi-daemon.conf
index 4761baa..b561f06 100644
--- a/avahi-daemon/avahi-daemon.conf
+++ b/avahi-daemon/avahi-daemon.conf
@@ -7,6 +7,7 @@ check-response-ttl=no
 use-iff-running=no
 enable-dbus=yes
 add-service-cookie=yes
+disallow-other-stacks=yes
 
 [wide-area]
 enable-wide-area=yes
diff --git a/avahi-daemon/main.c b/avahi-daemon/main.c
index 5320b68..07d7127 100644
--- a/avahi-daemon/main.c
+++ b/avahi-daemon/main.c
@@ -393,6 +393,8 @@ static int load_config_file(DaemonConfig *c) {
                     c->server_config.check_response_ttl = is_yes(p->value);
                 else if (strcasecmp(p->key, "use-iff-running") == 0)
                     c->server_config.use_iff_running = is_yes(p->value);
+                else if (strcasecmp(p->key, "disallow-other-stacks") == 0)
+                    c->server_config.disallow_other_stacks = is_yes(p->value);
                 else if (strcasecmp(p->key, "enable-dbus") == 0) {
 
                     if (*(p->value) == 'w' || *(p->value) == 'W') {
@@ -871,6 +873,7 @@ int main(int argc, char *argv[]) {
     init_rand_seed();
     
     avahi_server_config_init(&config.server_config);
+    config.server_config.disallow_other_stacks = 1;
     config.command = DAEMON_RUN;
     config.daemonize = 0;
     config.config_file = NULL;
diff --git a/docs/TODO b/docs/TODO
index ed55e5f..6a8bd50 100644
--- a/docs/TODO
+++ b/docs/TODO
@@ -11,8 +11,6 @@ for 0.6:
 * Add static host configuration like static services [lathiat]
 * wrap avahi_server_add_record() via DBUS and in avahi-client  [lathiat]
 
-* add option to disable SO_REUSEADDR to disallow binding of multiple processes to port 5353
-
 * add flags argument to disable cookies-setting for local services
 
 * reset commit throttling for entry groups after a while
@@ -87,3 +85,4 @@ done:
 * allow resolving of services without name
 * add sever version check to avahi-client
 * Passive observation of failures
+* add option to disable SO_REUSEADDR to disallow binding of multiple processes to port 5353