Merge pull request #238 from ianbarber/master

Wildcard support in TCP and IPC addresses

AUTHORS

@@ -33,6 +33,7 @@ Gerard Toonstra <gtoonstra@gmail.com>
 Ghislain Putois <ghpu@infonie.fr>
 Gonzalo Diethelm <gdiethelm@dcv.cl>
 Guido Goldstein <zmq@a-nugget.de>
+Ian Barber <ian.barber@gmail.com>
 Ilja Golshtein <ilejncs@narod.ru>
 Ivo Danihelka <ivo@danihelka.net>
 Jacob Rideout <jacob.rideout@returnpath.net>

doc/zmq_getsockopt.txt

@@ -391,6 +391,17 @@ Option value unit:: N/A (flags)
 Default value:: N/A
 Applicable socket types:: all
 
+ZMQ_LAST_ENDPOINT: Retrieve the last endpoint set
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The 'ZMQ_LAST_ENDPOINT' option shall retrieve the last endpoint bound for 
+TCP and IPC transports. The returned value will be a string in the form of
+a ZMQ DSN. 
+
+[horizontal]
+Option value type:: character string
+Option value unit:: N/A
+Default value:: NULL
+Applicable socket types:: all, when binding TCP or IPC transports
 
 RETURN VALUE
 ------------

include/zmq.h

@@ -221,6 +221,7 @@ ZMQ_EXPORT int zmq_term (zmq_ctx_t context);
 #define ZMQ_RCVTIMEO 27
 #define ZMQ_SNDTIMEO 28
 #define ZMQ_IPV4ONLY 31
+#define ZMQ_LAST_ENDPOINT 32
 
 /*  Message options                                                           */
 #define ZMQ_MORE 1

src/ipc_listener.cpp

@@ -95,8 +95,32 @@ void zmq::ipc_listener_t::in_event ()
     send_attach (session, engine, false);
 }
 
+int zmq::ipc_listener_t::get_address (std::string *addr_)
+{
+    struct sockaddr_un sun;
+    int rc;
+
+    // Get the details of the IPC socket
+    socklen_t sl = sizeof(sockaddr_un);                 
+    rc = getsockname (s, (sockaddr *)&sun, &sl);   
+    if (rc != 0) {
+        return rc;
+    }
+    
+    // Store the address for retrieval by users using wildcards
+    *addr_ = std::string("ipc://") + std::string(sun.sun_path);
+
+    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_);
@@ -124,7 +148,7 @@ int zmq::ipc_listener_t::set_address (const char *addr_)
     rc = listen (s, options.backlog);
     if (rc != 0)
         return -1;
-
+        
     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(std::string *addr_);
 
     private:
 

src/options.cpp

@@ -213,7 +213,6 @@ int zmq::options_t::setsockopt (int option_, const void *optval_,
             ipv4only = val;
             return 0;
         }
-
     }
 
     errno = EINVAL;
@@ -385,7 +384,16 @@ int zmq::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
         *((int*) optval_) = ipv4only;
         *optvallen_ = sizeof (int);
         return 0;
-
+        
+    case ZMQ_LAST_ENDPOINT:
+        // don't allow string which cannot contain the entire message
+        if (*optvallen_ < last_endpoint.size() + 1) {
+            errno = EINVAL;
+            return -1;
+        }
+        memcpy (optval_, last_endpoint.c_str(), last_endpoint.size()+1);
+        *optvallen_ = last_endpoint.size()+1;
+        return 0;
     }
 
     errno = EINVAL;

src/options.hpp

@@ -23,6 +23,8 @@
 #ifndef __ZMQ_OPTIONS_HPP_INCLUDED__
 #define __ZMQ_OPTIONS_HPP_INCLUDED__
 
+#include <string>
+
 #include "stddef.h"
 #include "stdint.hpp"
 
@@ -46,6 +48,9 @@ namespace zmq
         //  Socket identity
         unsigned char identity_size;
         unsigned char identity [256];
+        
+        // Last socket endpoint URI
+        std::string last_endpoint;
 
         //  Maximum tranfer rate [kb/s]. Default 100kb/s.
         int rate;

src/socket_base.cpp

@@ -161,6 +161,7 @@ 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;
@@ -340,6 +341,8 @@ int zmq::socket_base_t::bind (const char *addr_)
             delete listener;
             return -1;
         }
+        
+        rc = listener->get_address (&options.last_endpoint);
         launch_child (listener);
         return 0;
     }
@@ -354,6 +357,8 @@ int zmq::socket_base_t::bind (const char *addr_)
             delete listener;
             return -1;
         }
+        
+        rc = listener->get_address (&options.last_endpoint);
         launch_child (listener);
         return 0;
     }

src/tcp_address.cpp

@@ -387,11 +387,18 @@ 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;
+    // Allow 0 specifically, to detect invalid port error in atoi if not
+    if (port_str[0] == '*' || port_str[0] == '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

@@ -22,6 +22,7 @@
 #include <new>
 
 #include <string.h>
+#include <sstream>
 
 #include "platform.hpp"
 #include "tcp_listener.hpp"
@@ -119,6 +120,40 @@ void zmq::tcp_listener_t::close ()
     s = retired_fd;
 }
 
+int zmq::tcp_listener_t::get_address (std::string *addr_)
+{ 
+    struct sockaddr sa;
+    char host[INET6_ADDRSTRLEN];
+    int port, rc;
+    std::stringstream portnum;
+    
+    // Get the details of the TCP socket
+    socklen_t sl = sizeof(sockaddr);                 
+    rc = getsockname (s, &sa, &sl);   
+    if (rc != 0) {
+        return rc;
+    }
+    
+    // Split the retrieval between IPv4 and v6 addresses
+    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);
+        portnum << port;
+        
+        // Store the address for retrieval by users using wildcards
+        *addr_ = std::string("tcp://") + std::string(host) + std::string(":") + portnum.str();
+    } else {
+        inet_ntop(AF_INET6, &(((struct sockaddr_in6 *)&sa)->sin6_addr), host, INET6_ADDRSTRLEN);
+        port = ntohs( ((struct sockaddr_in6 *)&sa)->sin6_port);
+        portnum << port;
+        
+        // Store the address for retrieval by users using wildcards
+        *addr_ = std::string("tcp://[") + std::string(host) + std::string("]:") + portnum.str();
+    }
+    
+    return 0;
+}
+
 int zmq::tcp_listener_t::set_address (const char *addr_)
 {
     //  Convert the textual address into address structure.
@@ -168,6 +203,7 @@ 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

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 wildcard
+        int get_address(std::string *addr_);
 
     private: