handle case where writing status check packets blocks

we remember that, and try to write it again as soon as the
socket becomes writable

diff --git a/src/modules/rlm_radius/rlm_radius_udp.c b/src/modules/rlm_radius/rlm_radius_udp.c
index 2e96500871b18c6406110a4cda87f4293ccc4af1..51623562278dc6a36d0b053583106d798de5f93e 100644 (file)
--- a/src/modules/rlm_radius/rlm_radius_udp.c
+++ b/src/modules/rlm_radius/rlm_radius_udp.c
@@ -136,6 +136,7 @@ typedef struct rlm_radius_udp_connection_t {
         */
        rlm_radius_udp_request_t *status_u;             //!< For Status-Server checks.
        rlm_radius_id_t         *id;                    //!< RADIUS ID tracking structure.
+       bool                    status_check_blocked;   //!< if we blocked writing status check packets
 } rlm_radius_udp_connection_t;
 
 
@@ -438,6 +439,7 @@ static void conn_zombie_timeout(UNUSED fr_event_list_t *el, UNUSED struct timeva
                 *      Re-initialize the timers.
                 */
                u->timer.count = 0;
+               c->status_check_blocked = false;
 
                rcode = conn_write(c, u);
                if (rcode < 0) {
@@ -1402,7 +1404,12 @@ retransmit:
        /*
         *      If we wrote the packet to the connection, we're done.
         */
-       if (rcode != 0) return;
+       if (rcode != 0) {
+               if (u == c->status_u) {
+                       c->status_check_blocked = false;
+               }
+               return;
+       }
 
        /*
         *      EWOULDBLOCK, move the connection to blocked/
@@ -1411,10 +1418,13 @@ retransmit:
        conn_transition(c, CONN_BLOCKED);
 
        /*
-        *      @todo - status packets should get written as soon as
-        *      the socket becomes writable.
+        *      Remember to write status check packets as soon as the
+        *      socket becomes writable.
         */
-       if (u == c->status_u) return;
+       if (u == c->status_u) {
+               c->status_check_blocked = true;
+               return;
+       }
 
        /*
         *      Move the packet back to the thread queue, and try to
@@ -1767,20 +1777,45 @@ static void conn_writable(fr_event_list_t *el, UNUSED int fd, UNUSED int flags,
        bool                            pending = false;
        rlm_radius_udp_connection_state_t prev_state = c->state;
        rlm_radius_udp_connection_t     *next;
+       int                             rcode;
 
        DEBUG3("%s - Writing packets for connection %s", c->module_name, c->name);
 
        /*
-        *      @todo - if we have a pending status check packet,
-        *      write that first.
+        *      If we have a pending status check packet, write that
+        *      first.
         */
+       if (c->status_check_blocked) {
+               c->status_check_blocked = false;
+               rcode = conn_write(c, c->status_u);
+
+               /*
+                *      Error, close the connection.
+                */
+               if (rcode < 0) {
+                       talloc_free(c);
+                       return;
+               }
+
+               /*
+                *      Blocked, don't write anything more to the
+                *      connection.
+                */
+               if (rcode == 0) {
+                       c->status_check_blocked = true;
+                       conn_transition(c, CONN_BLOCKED);
+                       return;
+               }
+
+               /*
+                *      Written successfully, go write more packets.
+                */
+       }
 
        /*
         *      Empty the global queue of packets to send.
         */
        while ((u = fr_heap_peek(c->thread->queued)) != NULL) {
-               int rcode;
-
                rad_assert(u->state == PACKET_STATE_QUEUED);
 
                /*