Adding ZMQ_LAST_ENDPOINT for wildcard support on TCP and IPC sockets

include/zmq.h

@@ -193,6 +193,7 @@ ZMQ_EXPORT int zmq_term (void *context);
 #define ZMQ_RCVTIMEO 27
 #define ZMQ_SNDTIMEO 28
 #define ZMQ_IPV4ONLY 31
+#define ZMQ_LAST_ENDPOINT 32
 
 /*  Message options                                                           */
 #define ZMQ_MORE 1
@@ -201,6 +202,9 @@ ZMQ_EXPORT int zmq_term (void *context);
 #define ZMQ_DONTWAIT 1
 #define ZMQ_SNDMORE 2
 
+/*  Wildcard endpoint support.                                                */
+#define ZMQ_ENDPOINT_MAX 256
+
 ZMQ_EXPORT void *zmq_socket (void *context, int type);
 ZMQ_EXPORT int zmq_close (void *s);
 ZMQ_EXPORT int zmq_setsockopt (void *s, int option, const void *optval,

src/ipc_listener.cpp

@@ -95,8 +95,25 @@ void zmq::ipc_listener_t::in_event ()
     send_attach (session, engine, false);
 }
 
+int zmq::ipc_listener_t::get_address (unsigned char *addr, size_t *len)
+{
+    if (bound_addr_len == 0) {
+       return -1;
+    }
+    
+    memcpy (addr, bound_addr, bound_addr_len + 1);
+    *len = bound_addr_len + 1;
+    return 0;
+}
+
 int zmq::ipc_listener_t::set_address (const char *addr_)
 {
+    
+    // Allow wildcard file
+    if(*addr_ == '*') {
+        addr_ = tempnam(NULL, NULL);
+    }
+    
     //  Get rid of the file associated with the UNIX domain socket that
     //  may have been left behind by the previous run of the application.
     ::unlink (addr_);
@@ -125,6 +142,9 @@ int zmq::ipc_listener_t::set_address (const char *addr_)
     if (rc != 0)
         return -1;
 
+    // Return the bound address
+    bound_addr_len = sprintf(bound_addr, "ipc://%s", addr_);
+
     return 0;  
 }
 

src/ipc_listener.hpp

@@ -48,6 +48,9 @@ namespace zmq
 
         //  Set address to listen on.
         int set_address (const char *addr_);
+        
+        // Get the bound address for use with wildcards
+        int get_address(unsigned char *addr, size_t *len);
 
     private:
 
@@ -65,6 +68,10 @@ namespace zmq
         //  newly created connection. The function may return retired_fd
         //  if the connection was dropped while waiting in the listen backlog.
         fd_t accept ();
+        
+        // Store the connected endpoint for binds to port 0
+        char bound_addr[256];
+        size_t bound_addr_len;
 
         //  True, if the undelying file for UNIX domain socket exists.
         bool has_file;

src/options.cpp

@@ -30,6 +30,7 @@ zmq::options_t::options_t () :
     rcvhwm (1000),
     affinity (0),
     identity_size (0),
+    last_endpoint_size(0),
     rate (100),
     recovery_ivl (10000),
     multicast_hops (1),
@@ -213,7 +214,6 @@ int zmq::options_t::setsockopt (int option_, const void *optval_,
             ipv4only = val;
             return 0;
         }
-
     }
 
     errno = EINVAL;
@@ -385,7 +385,15 @@ int zmq::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
         *((int*) optval_) = ipv4only;
         *optvallen_ = sizeof (int);
         return 0;
-
+        
+    case ZMQ_LAST_ENDPOINT:
+        if (*optvallen_ < last_endpoint_size) {
+            errno = EINVAL;
+            return -1;
+        }
+        memcpy (optval_, last_endpoint, last_endpoint_size);
+        *optvallen_ = last_endpoint_size;
+        return 0;
     }
 
     errno = EINVAL;

src/options.hpp

@@ -46,6 +46,10 @@ namespace zmq
         //  Socket identity
         unsigned char identity_size;
         unsigned char identity [256];
+        
+        // Last socket endpoint URI
+        unsigned char last_endpoint [256];
+        size_t last_endpoint_size;
 
         //  Maximum tranfer rate [kb/s]. Default 100kb/s.
         int rate;

src/socket_base.cpp

@@ -160,6 +160,7 @@ int zmq::socket_base_t::parse_uri (const char *uri_,
     }
     protocol_ = uri.substr (0, pos);
     address_ = uri.substr (pos + 3);
+    
     if (protocol_.empty () || address_.empty ()) {
         errno = EINVAL;
         return -1;
@@ -339,6 +340,8 @@ int zmq::socket_base_t::bind (const char *addr_)
             delete listener;
             return -1;
         }
+        
+        rc = listener->get_address (options.last_endpoint, &(options.last_endpoint_size));
         launch_child (listener);
         return 0;
     }
@@ -353,6 +356,7 @@ int zmq::socket_base_t::bind (const char *addr_)
             delete listener;
             return -1;
         }
+        rc = listener->get_address (options.last_endpoint, &(options.last_endpoint_size));
         launch_child (listener);
         return 0;
     }

src/tcp_address.cpp

@@ -387,11 +387,17 @@ int zmq::tcp_address_t::resolve (const char *name_, bool local_, bool ipv4only_)
           addr_str [addr_str.size () - 1] == ']')
         addr_str = addr_str.substr (1, addr_str.size () - 2);
 
-    //  Parse the port number (0 is not a valid port).
-    uint16_t port = (uint16_t) atoi (port_str.c_str());
-    if (port == 0) {
-        errno = EINVAL;
-        return -1;
+    uint16_t port;
+    if (port_str[0] == '*') {
+        // Resolve wildcard to 0 to allow autoselection of port
+        port = 0;
+    } else {
+        //  Parse the port number (0 is not a valid port).
+        port = (uint16_t) atoi (port_str.c_str());
+        if (port == 0) {
+            errno = EINVAL;
+            return -1;
+        }
     }
 
     //  Resolve the IP address.

src/tcp_listener.cpp

@@ -52,6 +52,7 @@ zmq::tcp_listener_t::tcp_listener_t (io_thread_t *io_thread_,
       socket_base_t *socket_, const options_t &options_) :
     own_t (io_thread_, options_),
     io_object_t (io_thread_),
+    bound_addr_len (0),
     has_file (false),
     s (retired_fd),
     socket (socket_)
@@ -119,6 +120,17 @@ void zmq::tcp_listener_t::close ()
     s = retired_fd;
 }
 
+int zmq::tcp_listener_t::get_address (unsigned char *addr, size_t *len)
+{
+    if (bound_addr_len == 0) {
+       return -1;
+    }
+    
+    memcpy (addr, bound_addr, bound_addr_len + 1);
+    *len = bound_addr_len + 1;
+    return 0;
+}
+
 int zmq::tcp_listener_t::set_address (const char *addr_)
 {
     //  Convert the textual address into address structure.
@@ -168,6 +180,7 @@ int zmq::tcp_listener_t::set_address (const char *addr_)
     errno_assert (rc == 0);
 #endif
 
+    
     //  Bind the socket to the network interface and port.
     rc = bind (s, address.addr (), address.addrlen ());
 #ifdef ZMQ_HAVE_WINDOWS
@@ -180,6 +193,25 @@ int zmq::tcp_listener_t::set_address (const char *addr_)
         return -1;
 #endif
 
+    struct sockaddr sa;
+    socklen_t sl = sizeof(sockaddr);                 
+    rc = getsockname (s, &sa, &sl);   
+    if (rc == 0) {
+        char host[INET6_ADDRSTRLEN];
+        int port;
+        
+        if ( sa.sa_family == AF_INET ) {
+            inet_ntop(AF_INET, &(((struct sockaddr_in *)&sa)->sin_addr), host, INET6_ADDRSTRLEN);
+            port = ntohs( ((struct sockaddr_in *)&sa)->sin_port);
+        } else {
+            inet_ntop(AF_INET6, &(((struct sockaddr_in6 *)&sa)->sin6_addr), host, INET6_ADDRSTRLEN);
+            port = ntohs( ((struct sockaddr_in6 *)&sa)->sin6_port);
+        }
+        
+        // Store the address for retrieval by users using wildcards
+        bound_addr_len = sprintf(bound_addr, "tcp://%s:%d", host, port);
+    }            
+    
     //  Listen for incomming connections.
     rc = listen (s, options.backlog);
 #ifdef ZMQ_HAVE_WINDOWS

src/tcp_listener.hpp

@@ -44,6 +44,9 @@ namespace zmq
 
         //  Set address to listen on.
         int set_address (const char *addr_);
+    
+        // Get the bound address for use with wildcards
+        int get_address(unsigned char *addr, size_t *len);
 
     private:
 
@@ -64,6 +67,10 @@ namespace zmq
 
         //  Address to listen on.
         tcp_address_t address;
+        
+        // Store the connected endpoint for binds to port 0
+        char bound_addr[256];
+        size_t bound_addr_len;
 
         //  True, if the undelying file for UNIX domain socket exists.
         bool has_file;