socket: handle binding to "host!<ip>"

Regression since 3060557af702d (shipped in 8.9.0)

Fixes #15553
Reported-by: marcos-ng on github
Closes #15583

diff --git a/lib/cf-socket.c b/lib/cf-socket.c
index b4840f7ebc5607b0dbc0b8960f6d9b51f898229a..497a3b965f1250f5b23641d35ea92dc285b42a14 100644 (file)
--- a/lib/cf-socket.c
+++ b/lib/cf-socket.c
@@ -600,36 +600,39 @@ static CURLcode bindlocal(struct Curl_easy *data, struct connectdata *conn,
   if(!iface && !host && !port)
     /* no local kind of binding was requested */
     return CURLE_OK;
+  else if(iface && (strlen(iface) >= 255) )
+    return CURLE_BAD_FUNCTION_ARGUMENT;
 
   memset(&sa, 0, sizeof(struct Curl_sockaddr_storage));
 
-  if(iface && (strlen(iface) < 255) ) {
+  if(iface || host) {
     char myhost[256] = "";
     int done = 0; /* -1 for error, 1 for address found */
     if2ip_result_t if2ip_result = IF2IP_NOT_FOUND;
 
-    /* interface */
 #ifdef SO_BINDTODEVICE
-    /*
-      * This binds the local socket to a particular interface. This will
-      * force even requests to other local interfaces to go out the external
-      * interface. Only bind to the interface when specified as interface,
-      * not just as a hostname or ip address.
-      *
-      * The interface might be a VRF, eg: vrf-blue, which means it cannot be
-      * converted to an IP address and would fail Curl_if2ip. Simply try to
-      * use it straight away.
-      */
-    if(setsockopt(sockfd, SOL_SOCKET, SO_BINDTODEVICE,
-                  iface, (curl_socklen_t)strlen(iface) + 1) == 0) {
-      /* This is often "errno 1, error: Operation not permitted" if you are
-        * not running as root or another suitable privileged user. If it
-        * succeeds it means the parameter was a valid interface and not an IP
-        * address. Return immediately.
-        */
-      if(!host_input) {
-        infof(data, "socket successfully bound to interface '%s'", iface);
-        return CURLE_OK;
+    if(iface) {
+      /*
+       * This binds the local socket to a particular interface. This will
+       * force even requests to other local interfaces to go out the external
+       * interface. Only bind to the interface when specified as interface,
+       * not just as a hostname or ip address.
+       *
+       * The interface might be a VRF, eg: vrf-blue, which means it cannot be
+       * converted to an IP address and would fail Curl_if2ip. Simply try to
+       * use it straight away.
+       */
+      if(setsockopt(sockfd, SOL_SOCKET, SO_BINDTODEVICE,
+                    iface, (curl_socklen_t)strlen(iface) + 1) == 0) {
+        /* This is often "errno 1, error: Operation not permitted" if you are
+         * not running as root or another suitable privileged user. If it
+         * succeeds it means the parameter was a valid interface and not an IP
+         * address. Return immediately.
+         */
+        if(!host_input) {
+          infof(data, "socket successfully bound to interface '%s'", iface);
+          return CURLE_OK;
+        }
       }
     }
 #endif