ppp: use common code to get options from pppcp packet data

diff --git a/gatchat/ppp_cp.c b/gatchat/ppp_cp.c
index 263fa8b..d7d70b7 100644 (file)
--- a/gatchat/ppp_cp.c
+++ b/gatchat/ppp_cp.c
@@ -1140,6 +1140,22 @@ static void remove_config_option(gpointer elem, gpointer user_data)
        data->config_options = g_list_delete_link(data->config_options, list);
 }
 
+static struct ppp_option *extract_ppp_option(guint8 *packet_data)
+{
+       struct ppp_option *option;
+       guint8 otype = packet_data[0];
+       guint8 olen = packet_data[1];
+
+       option = g_try_malloc0(olen);
+       if (option == NULL)
+               return NULL;
+
+       option->type = otype;
+       option->length = olen;
+       memcpy(option->data, &packet_data[2], olen-2);
+       return option;
+}
+
 static guint8 pppcp_process_configure_request(struct pppcp_data *data,
                                        struct pppcp_packet *packet)
 {
@@ -1157,14 +1173,13 @@ static guint8 pppcp_process_configure_request(struct pppcp_data *data,
         * check the options.
         */
        while (i < len) {
-               guint8 otype = packet->data[i];
-               guint8 olen = packet->data[i+1];
-               option = g_try_malloc0(olen);
+               option = extract_ppp_option(&packet->data[i]);
                if (option == NULL)
                        break;
-               option->type = otype;
-               option->length = olen;
-               memcpy(option->data, &packet->data[i+2], olen-2);
+
+               /* skip ahead to the next option */
+               i += option->length;
+
                if (action->option_scan)
                        rval = action->option_scan(option, data);
                switch (rval) {
@@ -1182,10 +1197,9 @@ static guint8 pppcp_process_configure_request(struct pppcp_data *data,
                                                option);
                        break;
                case OPTION_ERR:
-                       g_printerr("unhandled option type %d\n", otype);
+                       g_printerr("unhandled option type %d\n", option->type);
+                       g_free(option);
                }
-               /* skip ahead to the next option */
-               i += olen;
        }
 
        /* make sure all required config options were included */
@@ -1242,16 +1256,12 @@ static guint8 pppcp_process_configure_ack(struct pppcp_data *data,
         * and apply them.
         */
        while (i < len) {
-               guint8 otype = packet->data[i];
-               guint8 olen = packet->data[i + 1];
-               acked_option = g_try_malloc0(olen);
+               acked_option = extract_ppp_option(&packet->data[i]);
                if (acked_option == NULL)
                        break;
-               acked_option->type = otype;
-               acked_option->length = olen;
-               memcpy(acked_option->data, &packet->data[i + 2], olen - 2);
                list = g_list_find_custom(data->config_options,
-                               GUINT_TO_POINTER((guint) otype), is_option);
+                               GUINT_TO_POINTER((guint) acked_option->type),
+                               is_option);
                if (list) {
                        /*
                         * once we've applied the option, delete it from
@@ -1266,10 +1276,11 @@ static guint8 pppcp_process_configure_ack(struct pppcp_data *data,
                                g_list_delete_link(data->config_options, list);
                } else
                        g_printerr("oops -- found acked option %d we didn't request\n", acked_option->type);
-               g_free(acked_option);
 
                /* skip ahead to the next option */
-               i += olen;
+               i += acked_option->length;
+
+               g_free(acked_option);
        }
        return RCA;
 }
@@ -1300,14 +1311,13 @@ static guint8 pppcp_process_configure_nak(struct pppcp_data *data,
         * modify a value there, or add a new option.
         */
        while (i < len) {
-               guint8 otype = packet->data[i];
-               guint8 olen = packet->data[i+1];
-               naked_option = g_try_malloc0(olen);
+               naked_option = extract_ppp_option(&packet->data[i]);
                if (naked_option == NULL)
                        break;
-               naked_option->type = otype;
-               naked_option->length = olen;
-               memcpy(naked_option->data, &packet->data[i + 2], olen - 2);
+
+               /* skip ahead to the next option */
+               i += naked_option->length;
+
                if (action->option_scan)
                        rval = action->option_scan(naked_option, data);
                if (rval == OPTION_ACCEPT) {
@@ -1316,7 +1326,8 @@ static guint8 pppcp_process_configure_nak(struct pppcp_data *data,
                         * match.
                         */
                        list = g_list_find_custom(data->config_options,
-                               GUINT_TO_POINTER((guint) otype), is_option);
+                               GUINT_TO_POINTER((guint) naked_option->type),
+                               is_option);
                        if (list) {
                                /* modify current option value to match */
                                config_option = list->data;
@@ -1326,10 +1337,11 @@ static guint8 pppcp_process_configure_nak(struct pppcp_data *data,
                                 * we need to reallocate
                                 */
                                if ((config_option->length ==
-                                       naked_option->length) && (olen - 2)) {
+                                       naked_option->length) &&
+                                                       (naked_option - 2)) {
                                                memcpy(config_option->data,
-                                                       naked_option->data,
-                                                       olen - 2);
+                                                  naked_option->data,
+                                                  naked_option->length - 2);
                                } else {
                                        /* XXX implement this */
                                        g_printerr("uh oh, option value doesn't match\n");
@@ -1344,9 +1356,6 @@ static guint8 pppcp_process_configure_nak(struct pppcp_data *data,
                        g_printerr("oops, option wasn't acceptable\n");
                        g_free(naked_option);
                }
-
-               /* skip ahead to the next option */
-               i += olen;
        }
        return RCN;
 }