Agressively reconnect connections on write errors

diff --git a/src/modules/rlm_radius/rlm_radius_udp.c b/src/modules/rlm_radius/rlm_radius_udp.c
index a7d17cfd1ec692661babf60c64bf25af20d3bf41..1dc7884795531b75744923c0b6f04bf9056a470a 100644 (file)
--- a/src/modules/rlm_radius/rlm_radius_udp.c
+++ b/src/modules/rlm_radius/rlm_radius_udp.c
@@ -1243,7 +1243,13 @@ static void request_timeout(fr_event_list_t *el, fr_time_t now, void *uctx)
        fr_trunk_request_requeue(treq);
 }
 
-
+/** Attempt to write a packet to a connection
+ *
+ * @return
+ *     - 0 on success.
+ *     - 1 if no outbound buffer space available.
+ *     - -1 on connection error.
+ */
 static int write_packet(fr_event_list_t *el, fr_trunk_request_t *treq, uint8_t const *packet, size_t packet_len)
 {
        char const              *action;
@@ -1294,9 +1300,14 @@ static int write_packet(fr_event_list_t *el, fr_trunk_request_t *treq, uint8_t c
 
        slen = write(h->fd, packet, packet_len);
        if (slen < 0) {
-               // @todo - handle EWOULDBLOCK
-               REDEBUG("Failed writing packet to %s - %s", h->name, fr_syserror(errno));
-               return -1;
+               switch (errno) {
+               case EWOULDBLOCK:
+                       return 1;
+
+               default:
+                       REDEBUG("Failed writing packet to %s - %s", h->name, fr_syserror(errno));
+                       return -1;
+               }
        }
        rad_assert((size_t) slen == packet_len);        /* Should never get partial writes with UDP */
 
@@ -1340,7 +1351,6 @@ static void request_mux(fr_event_list_t *el,
                               fr_packet_codes[u->code], u->rr->id, u->packet_len, h->name);
 
                        if (encode(h->inst, request, u, u->rr->id, false) < 0) {
-                       fail_after_alloc:
                                udp_request_clear(u, h, 0);
                                if (u->ev) (void) fr_event_timer_delete(&u->ev);
                                goto fail;
@@ -1360,14 +1370,24 @@ static void request_mux(fr_event_list_t *el,
                log_request_pair_list(L_DBG_LVL_2, request, request->packet->vps, NULL);
                if (u->extra) log_request_pair_list(L_DBG_LVL_2, request, u->extra, NULL);
 
-               if (write_packet(el, treq, u->packet, u->packet_len) < 0) goto fail_after_alloc;
-               fr_trunk_request_signal_sent(treq);
+               switch (write_packet(el, treq, u->packet, u->packet_len)) {
+               case 0:
+                       break;
+
+               case 1: /* no space - save encoded packet for later */
+                       return;
+
+               case -1:
+                       fr_trunk_connection_signal_reconnect(tconn, FR_CONNECTION_FAILED);
+                       return;
+               }
 
                /*
                 *      Tell the trunk API that this request is now in
                 *      the "sent" state.  And we don't want to see
                 *      this request again.
                 */
+               fr_trunk_request_signal_sent(treq);
                u->c = c;
 
                // @todo - if there are no free IDs, call fr_trunk_connection_requests_requeue()