specify client-side port: UDP support

--cport can be specified for udp connections

Signed-off-by: Kevin Constantine <kevin.constantine@gmail.com>

src/iperf_client_api.c

@@ -268,7 +268,8 @@ iperf_connect(struct iperf_test *test)
 
     /* Create and connect the control channel */
     if (test->ctrl_sck < 0)
-	test->ctrl_sck = netdial(test->settings->domain, Ptcp, test->bind_address, test->server_hostname, test->server_port);
+	// Create the control channel using an ephemeral port
+	test->ctrl_sck = netdial(test->settings->domain, Ptcp, test->bind_address, NULL, test->server_hostname, test->server_port);
     if (test->ctrl_sck < 0) {
         i_errno = IECONNECT;
         return -1;

src/iperf_udp.c

@@ -234,7 +234,7 @@ iperf_udp_connect(struct iperf_test *test)
 {
     int s, buf, sz;
 
-    if ((s = netdial(test->settings->domain, Pudp, test->bind_address, test->server_hostname, test->server_port)) < 0) {
+    if ((s = netdial(test->settings->domain, Pudp, test->bind_address, test->bind_port, test->server_hostname, test->server_port)) < 0) {
         i_errno = IESTREAMCONNECT;
         return -1;
     }

src/net.c

@@ -48,7 +48,7 @@
 
 /* make connection to server */
 int
-netdial(int domain, int proto, char *local, char *server, int port)
+netdial(int domain, int proto, char *local, int local_port, char *server, int port)
 {
     struct addrinfo hints, *local_res, *server_res;
     int s;
@@ -76,6 +76,13 @@ netdial(int domain, int proto, char *local, char *server, int port)
     }
 
     if (local) {
+        if (local_port) {
+            struct sockaddr_in *lcladdr;
+            lcladdr = (struct sockaddr_in *)local_res->ai_addr;
+            lcladdr->sin_port = htons(local_port);
+            local_res->ai_addr = (struct sockaddr *)lcladdr;
+        }
+
         if (bind(s, (struct sockaddr *) local_res->ai_addr, local_res->ai_addrlen) < 0) {
 	    close(s);
 	    freeaddrinfo(local_res);

src/net.h

@@ -10,7 +10,7 @@
 #ifndef __NET_H
 #define __NET_H
 
-int netdial(int domain, int proto, char *local, char *server, int port);
+int netdial(int domain, int proto, char *local, int local_port, char *server, int port);
 int netannounce(int domain, int proto, char *local, int port);
 int Nread(int fd, char *buf, size_t count, int prot);
 int Nwrite(int fd, const char *buf, size_t count, int prot) /* __attribute__((hot)) */;