diff -u srelay-0.4.6.orig/main.c srelay-0.4.6/main.c
--- srelay-0.4.6.orig/main.c	2003-03-26 20:45:12.000000000 +0000
+++ srelay-0.4.6/main.c	2007-08-09 13:53:30.000000000 +0100
@@ -43,6 +43,7 @@
 char *ident = "srelay";
 char *pidfile = PIDFILE;
 char *pwdfile = PWDFILE;
+char *bindtodevice = NULL;
 pid_t master_pid;
 
 #if USE_THREAD
@@ -74,6 +75,9 @@
   fprintf(stderr, "options:\n"
 	  "\t-c file\tconfig file\n"
 	  "\t-i i/f\tlisten interface IP[:PORT]\n"
+#ifdef SO_BINDTODEVICE
+	  "\t-J i/f\toutbound interface name\n"
+#endif
 	  "\t-m num\tmax child/thread\n"
 	  "\t-o min\tidle timeout minutes\n"
 	  "\t-p file\tpid file\n"
@@ -125,7 +129,7 @@
 
   uid = getuid();
 
-  while((ch = getopt(ac, av, "a:c:i:m:o:p:u:frstbvh?")) != -1)
+  while((ch = getopt(ac, av, "a:c:i:J:m:o:p:u:frstbvh?")) != -1)
     switch (ch) {
     case 'a':
       if (optarg != NULL) {
@@ -180,6 +184,14 @@
       }
       break;
 
+#ifdef SO_BINDTODEVICE
+    case 'J':
+      if (optarg != NULL) {
+	bindtodevice = strdup(optarg);
+      }
+      break;
+#endif
+
     case 'o':
       if (optarg != NULL) {
 	idle_timeout = atol(optarg);
diff -u srelay-0.4.6.orig/socks.c srelay-0.4.6/socks.c
--- srelay-0.4.6.orig/socks.c	2003-04-13 22:13:25.000000000 +0100
+++ srelay-0.4.6/socks.c	2007-08-09 14:44:24.000000000 +0100
@@ -990,6 +990,24 @@
   return(-1);
 }
 
+#ifdef SO_BINDTODEVICE
+#include <net/if.h>
+static int do_bindtodevice(int cs, char *dev)
+{
+  int rc;
+  struct ifreq interface;
+  
+  strncpy(interface.ifr_name, dev, IFNAMSIZ);
+  setreuid(PROCUID, 0);
+  rc = setsockopt(cs, SOL_SOCKET, SO_BINDTODEVICE,
+                  (char *)&interface, sizeof(interface));
+  setreuid(0, PROCUID);
+  if (rc < 0)
+    msg_out(crit, "setsockopt SO_BINDTODEVICE(%s) failed: %d", dev, errno);
+  return(rc);
+}
+#endif
+
 int socks_direct_conn(int ver, struct socks_req *req)
 {
   int    cs, acs = 0;
@@ -1037,6 +1055,14 @@
         continue;
       }
 
+#ifdef SO_BINDTODEVICE
+      if (bindtodevice && do_bindtodevice(cs, bindtodevice) < 0) {
+        save_errno = errno;
+        close(cs);
+        continue;
+      }
+#endif
+
       if (connect(cs, res->ai_addr, res->ai_addrlen) < 0) {
         /* connect fail */
 	save_errno = errno;
@@ -1096,6 +1122,14 @@
       return(-1);
     }
 
+#ifdef SO_BINDTODEVICE
+    if (bindtodevice && do_bindtodevice(acs, bindtodevice) < 0) {
+      GEN_ERR_REP(req->s, ver);
+      close(acs);
+      return(-1);
+    }
+#endif
+
     if (bind_sock(acs, req, &ba) != 0) {
       GEN_ERR_REP(req->s, ver);
       return(-1);
@@ -1351,6 +1385,14 @@
       continue;
     }
 
+#ifdef SO_BINDTODEVICE
+    if (bindtodevice && do_bindtodevice(cs, bindtodevice) < 0) {
+      save_errno = errno;
+      close(cs);
+      continue;
+    }
+#endif
+
     if (connect(cs, res->ai_addr, res->ai_addrlen) < 0) {
       /* connect fail */
       save_errno = errno;
diff -u srelay-0.4.6.orig/srelay.h srelay-0.4.6/srelay.h
--- srelay-0.4.6.orig/srelay.h	2003-04-14 06:36:15.000000000 +0100
+++ srelay-0.4.6/srelay.h	2007-08-09 13:46:06.000000000 +0100
@@ -266,6 +266,7 @@
 extern char *ident;
 extern char *pidfile;
 extern char *pwdfile;
+extern char *bindtodevice;
 extern int max_child;
 extern int cur_child;
 extern char method_tab[];
