From 74f488d6757c076f17f7d331d9ff80e6476bf647 Mon Sep 17 00:00:00 2001
From: Jason Glasgow <jglasgow@chromium.org>
Date: Thu, 3 Nov 2011 20:00:07 -0400
Subject: [PATCH] connect: add a flag so interface name only refers to an interface name

add a flag so interface name only refers to an interface name not a
hostname.  This prevents connect from blocking, which is the desired
behavior when using the mulit interfaces with c-ares.
---
 include/curl/curl.h |    3 +++
 lib/connect.c       |    3 +++
 lib/url.c           |   10 ++++++++++
 lib/urldata.h       |    1 +
 4 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/include/curl/curl.h b/include/curl/curl.h
index f4aa17f..1fc2476 100644
--- a/include/curl/curl.h
+++ b/include/curl/curl.h
@@ -1486,6 +1486,9 @@ typedef enum {
   /* allow GSSAPI credential delegation */
   CINIT(GSSAPI_DELEGATION, LONG, 210),
 
+  /* Force the interface to be only an interface not a hostname */
+  CINIT(BIND_INTERFACE_ONLY, LONG, 211),
+
   CURLOPT_LASTENTRY /* the last unused */
 } CURLoption;
 
diff --git a/lib/connect.c b/lib/connect.c
index 2a1876e..56a57b1 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -308,6 +308,9 @@ static CURLcode bindlocal(struct connectdata *conn,
       long ipver = conn->ip_version;
       int rc;
 
+      if(data->set.bind_interface_only)
+        return CURLE_INTERFACE_FAILED;
+
       if(af == AF_INET)
         conn->ip_version = CURL_IPRESOLVE_V4;
 #ifdef ENABLE_IPV6
diff --git a/lib/url.c b/lib/url.c
index 4bc82a6..ac1e269 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -1964,6 +1964,16 @@ CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option,
     result = setstropt(&data->set.str[STRING_DEVICE],
                        va_arg(param, char *));
     break;
+
+  case CURLOPT_BIND_INTERFACE_ONLY:
+    /*
+     * Force device to only refer to an interface name.  Do not try
+     * DNS on it.  Usefully when using multi sockets because DNS
+     * resolution may block.
+     */
+    data->set.bind_interface_only = (bool)(0 != va_arg(param, long));
+    break;
+
   case CURLOPT_LOCALPORT:
     /*
      * Set what local port to bind the socket to when performing an operation.
diff --git a/lib/urldata.h b/lib/urldata.h
index 3e7db25..7aec400 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -1517,6 +1517,7 @@ struct UserDefined {
   unsigned int scope;    /* address scope for IPv6 */
   long allowed_protocols;
   long redir_protocols;
+  bool bind_interface_only; /* force STRING_DEVICE to refer to an interface */
 #if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
   long socks5_gssapi_nec; /* flag to support nec socks5 server */
 #endif
-- 
1.7.3.1