ppp: handle Config-Reject

if our peer sends us a Config-Reject packet, we must delete that
config item and not request that it be negotiated when we send our
next Config-Request.

diff --git a/gatchat/ppp_cp.c b/gatchat/ppp_cp.c
index d7d70b7..ac1a37d 100644 (file)
--- a/gatchat/ppp_cp.c
+++ b/gatchat/ppp_cp.c
@@ -1363,22 +1363,49 @@ static guint8 pppcp_process_configure_nak(struct pppcp_data *data,
 static guint8 pppcp_process_configure_reject(struct pppcp_data *data,
                                        struct pppcp_packet *packet)
 {
+       guint len;
+       GList *list;
+       struct ppp_option *rejected_option;
+       guint i = 0;
+
+       len = ntohs(packet->length) - CP_HEADER_SZ;
+
        /*
         * make sure identifier matches that of last sent configure
         * request
         */
-       if (packet->identifier == data->config_identifier) {
-               /*
-                * check to see which options were rejected
-                * Rejected options must be a subset of requested
-                * options.
-                *
-                * when a new configure-request is sent, we may
-                * not request any of these options be negotiated
-                */
-               return RCN;
+       if (packet->identifier != data->config_identifier)
+               return 0;
+
+       /*
+        * check to see which options were rejected
+        * Rejected options must be a subset of requested
+        * options.
+        *
+        * when a new configure-request is sent, we may
+        * not request any of these options be negotiated
+        */
+       while (i < len) {
+               rejected_option = extract_ppp_option(&packet->data[i]);
+               if (rejected_option == NULL)
+                       break;
+
+               /* skip ahead to the next option */
+               i += rejected_option->length;
+
+               /* find this option in our config options list */
+               list = g_list_find_custom(data->config_options,
+                       GUINT_TO_POINTER((guint) rejected_option->type),
+                       is_option);
+               if (list) {
+                       /* delete this config option */
+                       g_free(list->data);
+                       data->config_options =
+                               g_list_delete_link(data->config_options, list);
+               }
+               g_free(rejected_option);
        }
-       return 0;
+       return RCN;
 }
 
 static guint8 pppcp_process_terminate_request(struct pppcp_data *data,