Initial commit of files

src/libnet/udp_server.c

@@ -0,0 +1,59 @@
+//
+// UDP Server
+//
+
+#include "netlib.h"
+
+int udp_server( const char *host, const char *service )
+{
+  /* socket stuff */
+  int    sock;       /* tcp socket */
+  
+  /* dual stack listener */
+  struct addrinfo hints;
+  struct addrinfo *res, *ressave;
+  
+  /* set-up hints structure */
+  bzero(&hints, sizeof(hints));
+  hints.ai_family = AF_UNSPEC;
+  hints.ai_flags = AI_PASSIVE;
+  hints.ai_socktype = SOCK_DGRAM;
+  if ( getaddrinfo(host, service, &hints, &res) )
+  {
+    log_error( "getaddrinfo" );
+    return -1;
+  }
+  ressave = res;
+  
+  /*
+   * "res" has a chain of addrinfo structure filled with
+   * 0.0.0.0 (for IPv4), 0:0:0:0:0:0:0:0 (for IPv6) and alike,
+   * with port filled for "myservice".
+   */
+  while (res)
+  {
+    /* bind() and listen() to res->ai_addr */
+    sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol );
+    if ( sock < 0 )
+      continue;
+    
+    /* bind */
+    if ( bind(sock, res->ai_addr, res->ai_addrlen) == 0 )
+      break;  // success
+      
+      /* error, try again */
+      close( sock );
+    res = res->ai_next;
+  }
+  
+  freeaddrinfo( ressave );
+  
+  /* able to bind? */
+  if ( !res )
+  {
+    log_error( "server" );
+    return -1;
+  }    
+  
+  return sock;
+}