First patch, bug 610752.

debian/netcfg-common.templates

@@ -329,3 +329,11 @@ Description: for internal use; can be preseeded
  Set to false to prevent /etc/network/interfaces being adjusted for use by
  network-manager. If you do this, network-manager will probably not work
  correctly.
+
+Template: netcfg/link_wait_timeout
+Type: string
+_Description: Waiting time
+ Enter waiting time (in seconds) for detecting the link. You
+ must enter a greater than zero value in order for it to be
+ considered. You can leave the field blank and a default value
+ will be used.

netcfg-common.c

@@ -1268,12 +1268,28 @@ int netcfg_detect_link(struct debconfclient *client, const char *if_name)
     int count, rv = 0;
     int link_waits = NETCFG_LINK_WAIT_TIME * 4;
     int gw_tries = NETCFG_GATEWAY_REACHABILITY_TRIES;
+    int ret;
 
     if (gateway.s_addr) {
         inet_ntop(AF_INET, &gateway, s_gateway, sizeof(s_gateway));
         sprintf(arping, "arping -c 1 -w 1 -f -I %s %s", if_name, s_gateway);
     }
-
+
+    /* Ask for link detection timeout. */
+    debconf_input(client, "low", "netcfg/link_wait_timeout");
+    ret = debconf_go(client);
+
+    if (!ret)
+        debconf_get(client, "netcfg/link_wait_timeout");
+
+    if (!ret && client->value) {
+        link_waits = atoi(client->value);
+
+        if (link_waits <= 0) {
+            link_waits = NETCFG_LINK_WAIT_TIME * 4;
+        }
+    }
+
     debconf_capb(client, "progresscancel");
     debconf_subst(client, "netcfg/link_detect_progress", "interface", if_name);
     debconf_progress_start(client, 0, 100, "netcfg/link_detect_progress");

netcfg.h

@@ -46,9 +46,8 @@
 "ff02::1 ip6-allnodes\n" \
 "ff02::2 ip6-allrouters\n"
 
-/* The time, in seconds, that we will wait for a link to be established
- * via link autonegotiation.  Sometime in the future this may become a
- * preseed option.
+/* The default time, in seconds, that we will wait for a link to be
+ * established via link autonegotiation.
  */
 #define NETCFG_LINK_WAIT_TIME 3