DoH: Fix missing send callback calls

When handling outgoing data, there were a couple of rarely executed
code paths that would not take into account that the callback MUST be
called.

It could lead to potential memory leaks and consequent shutdown hangs.

diff --git a/lib/isc/netmgr/http.c b/lib/isc/netmgr/http.c
index 2b7740d18a836511622f317436434aa2c9cd5e41..f18f972ff62ecf2c44a224648a48074f5491b6ce 100644 (file)
--- a/lib/isc/netmgr/http.c
+++ b/lib/isc/netmgr/http.c
@@ -1367,6 +1367,22 @@ move_pending_send_callbacks(isc_nm_http_session_t *session,
        ISC_LIST_INIT(session->pending_write_callbacks);
 }
 
+static inline void
+http_append_pending_send_request(isc_nm_http_session_t *session,
+                                isc_nmhandle_t *httphandle, isc_nm_cb_t cb,
+                                void *cbarg) {
+       REQUIRE(VALID_HTTP2_SESSION(session));
+       REQUIRE(VALID_NMHANDLE(httphandle));
+       REQUIRE(cb != NULL);
+
+       isc__nm_uvreq_t *newcb = isc__nm_uvreq_get(httphandle->sock);
+
+       newcb->cb.send = cb;
+       newcb->cbarg = cbarg;
+       isc_nmhandle_attach(httphandle, &newcb->handle);
+       ISC_LIST_APPEND(session->pending_write_callbacks, newcb, link);
+}
+
 static bool
 http_send_outgoing(isc_nm_http_session_t *session, isc_nmhandle_t *httphandle,
                   isc_nm_cb_t cb, void *cbarg) {
@@ -1378,10 +1394,25 @@ http_send_outgoing(isc_nm_http_session_t *session, isc_nmhandle_t *httphandle,
        size_t max_total_write_size = 0;
 #endif /* ENABLE_HTTP_WRITE_BUFFERING */
 
-       if (!http_session_active(session) ||
-           (!nghttp2_session_want_write(session->ngsession) &&
-            session->pending_write_data == NULL))
+       if (!http_session_active(session)) {
+               if (cb != NULL) {
+                       isc__nm_uvreq_t *req =
+                               isc__nm_uvreq_get(httphandle->sock);
+
+                       req->cb.send = cb;
+                       req->cbarg = cbarg;
+                       isc_nmhandle_attach(httphandle, &req->handle);
+                       isc__nm_sendcb(httphandle->sock, req, ISC_R_CANCELED,
+                                      true);
+               }
+               return false;
+       } else if (!nghttp2_session_want_write(session->ngsession) &&
+                  session->pending_write_data == NULL)
        {
+               if (cb != NULL) {
+                       http_append_pending_send_request(session, httphandle,
+                                                        cb, cbarg);
+               }
                return false;
        }
 
@@ -1448,16 +1479,8 @@ http_send_outgoing(isc_nm_http_session_t *session, isc_nmhandle_t *httphandle,
                 * will flush the buffer.
                 */
                if (cb != NULL) {
-                       isc__nm_uvreq_t *newcb = NULL;
-
-                       INSIST(VALID_NMHANDLE(httphandle));
-
-                       newcb = isc__nm_uvreq_get(httphandle->sock);
-                       newcb->cb.send = cb;
-                       newcb->cbarg = cbarg;
-                       isc_nmhandle_attach(httphandle, &newcb->handle);
-                       ISC_LIST_APPEND(session->pending_write_callbacks, newcb,
-                                       link);
+                       http_append_pending_send_request(session, httphandle,
+                                                        cb, cbarg);
                }
                goto nothing_to_send;
        } else if (session->sending == 0 && total == 0 &&
@@ -1499,6 +1522,10 @@ http_send_outgoing(isc_nm_http_session_t *session, isc_nmhandle_t *httphandle,
 
        if (total == 0) {
                /* No data returned */
+               if (cb != NULL) {
+                       http_append_pending_send_request(session, httphandle,
+                                                        cb, cbarg);
+               }
                goto nothing_to_send;
        }