Split out the common code from timed DNS updates

2 files changed, 121 insertions, 0 deletions

diff --git a/src/providers/ldap/sdap_dyndns.c b/src/providers/ldap/sdap_dyndns.c
index fbeb6a3d..d7e20ca4 100644
--- a/src/providers/ldap/sdap_dyndns.c
+++ b/src/providers/ldap/sdap_dyndns.c
@@ -627,3 +627,111 @@ sdap_dyndns_get_addrs_recv(struct tevent_req *req,
     *_addresses = talloc_steal(mem_ctx, state->addresses);
     return EOK;
 }
+
+struct sdap_dyndns_timer_state {
+    struct tevent_context *ev;
+    struct sdap_id_ctx *sdap_ctx;
+    struct be_nsupdate_ctx *dyndns_ctx;
+
+    struct sdap_id_op *sdap_op;
+};
+
+static void sdap_dyndns_timer_conn_done(struct tevent_req *req);
+
+struct tevent_req *
+sdap_dyndns_timer_conn_send(TALLOC_CTX *mem_ctx,
+                            struct tevent_context *ev,
+                            struct sdap_id_ctx *sdap_ctx,
+                            struct be_nsupdate_ctx *dyndns_ctx)
+{
+    struct sdap_dyndns_timer_state *state;
+    struct tevent_req *req;
+    struct tevent_req *subreq;
+    errno_t ret;
+
+    req = tevent_req_create(mem_ctx, &state, struct sdap_dyndns_timer_state);
+    if (req == NULL) {
+        return NULL;
+    }
+    state->ev = ev;
+    state->sdap_ctx = sdap_ctx;
+    state->dyndns_ctx = dyndns_ctx;
+
+    /* In order to prevent the connection triggering an
+     * online callback which would in turn trigger a concurrent DNS
+     * update
+     */
+    state->dyndns_ctx->timer_in_progress = true;
+
+    /* Make sure to have a valid LDAP connection */
+    state->sdap_op = sdap_id_op_create(state, state->sdap_ctx->conn_cache);
+    if (state->sdap_op == NULL) {
+        DEBUG(SSSDBG_OP_FAILURE, ("sdap_id_op_create failed\n"));
+        ret = ENOMEM;
+        goto fail;
+    }
+
+    subreq = sdap_id_op_connect_send(state->sdap_op, state, &ret);
+    if (subreq == NULL) {
+        DEBUG(SSSDBG_OP_FAILURE, ("sdap_id_op_connect_send failed: [%d](%s)\n",
+              ret, sss_strerror(ret)));
+        ret = ENOMEM;
+        goto fail;
+    }
+    tevent_req_set_callback(subreq, sdap_dyndns_timer_conn_done, req);
+    return req;
+
+fail:
+    dyndns_ctx->timer_in_progress = false;
+    be_nsupdate_timer_schedule(ev, dyndns_ctx);
+    tevent_req_error(req, ret);
+    tevent_req_post(req, ev);
+    return req;
+}
+
+
+static void
+sdap_dyndns_timer_conn_done(struct tevent_req *subreq)
+{
+    struct tevent_req *req = tevent_req_callback_data(subreq,
+                                                      struct tevent_req);
+    struct sdap_dyndns_timer_state *state = tevent_req_data(req,
+                                            struct sdap_dyndns_timer_state);
+    errno_t ret;
+    int dp_error;
+
+    state->dyndns_ctx->timer_in_progress = false;
+
+    ret = sdap_id_op_connect_recv(subreq, &dp_error);
+    talloc_zfree(subreq);
+    if (ret != EOK) {
+        if (dp_error == DP_ERR_OFFLINE) {
+            DEBUG(SSSDBG_MINOR_FAILURE, ("No server is available, "
+                  "dynamic DNS update is skipped in offline mode.\n"));
+            /* Another timer will be scheduled when provider goes online */
+            tevent_req_error(req, ERR_DYNDNS_OFFLINE);
+        } else {
+            DEBUG(SSSDBG_OP_FAILURE,
+                  ("Failed to connect to LDAP server: [%d](%s)\n",
+                  ret, sss_strerror(ret)));
+
+            /* Just schedule another dyndns retry */
+            be_nsupdate_timer_schedule(state->ev, state->dyndns_ctx);
+            tevent_req_error(req, ERR_NETWORK_IO);
+        }
+        return;
+    }
+
+    /* All OK, schedule another refresh and let the user call its
+     * provider-specific update
+     */
+    be_nsupdate_timer_schedule(state->ev, state->dyndns_ctx);
+    tevent_req_done(req);
+}
+
+errno_t
+sdap_dyndns_timer_conn_recv(struct tevent_req *req)
+{
+    TEVENT_REQ_RETURN_ON_ERROR(req);
+    return EOK;
+}
diff --git a/src/providers/ldap/sdap_dyndns.h b/src/providers/ldap/sdap_dyndns.h
index 66de64a5..7aaff5d2 100644
--- a/src/providers/ldap/sdap_dyndns.h
+++ b/src/providers/ldap/sdap_dyndns.h
@@ -47,4 +47,17 @@ sdap_dyndns_update_send(TALLOC_CTX *mem_ctx,
 
 errno_t sdap_dyndns_update_recv(struct tevent_req *req);
 
+/* Connects to the LDAP server in order to read the address from the
+ * socket and be able to perform dynamic DNS updates. Reschedules the
+ * task automatically on errors and sets/resets the timer_in_progress
+ * guard in be_nsupdate_ctx.
+ */
+struct tevent_req *
+sdap_dyndns_timer_conn_send(TALLOC_CTX *mem_ctx,
+                            struct tevent_context *ev,
+                            struct sdap_id_ctx *sdap_ctx,
+                            struct be_nsupdate_ctx *dyndns_ctx);
+
+errno_t sdap_dyndns_timer_conn_recv(struct tevent_req *req);
+
 #endif /* SDAP_DYNDNS_H_ */