zebra - BFD client de-registration support

CM-10680
Issue: When BGP daemon is stopped, all the BGP BFD sessions are not getting deleted from PTM.
Root cause: BGP daemon stop causes BFD de-register message to be sent for every peer on which BFD is enabled. But, all the de-register messages from bgpd to zebra are not processed before the socket close. This results in some stale BGP BFD sessions.
Fix: Support for client de-register message has been added in PTM/BFD.  Changes in Quagga to support BFD client de-registrations:
−   The BFD clients de-registration is sent directly from zebra daemon when zebra client (bgpd, ospfd and ospf6d) socket close is detected.
−   Introduced a BFD flag for the zebra clients to prevent BFD de-registration messages from being sent to zebra daemon when the client is shutting down. This reduces the BFD messaging.

CM-10540
Issue: Invalid ptm status “fail” instead of “n/a” being displayed for VRF interfaces.
Root cause: ptm status is not being initialized to “unknown” status when VRF interface is added or changed. The uninitialized value is ‘0’ which is the value for “fail”
Fix: Initialized the ptm status to the correct value.

Signed-off-by: Radhika Mahankali <radhika@cumulusnetworks.com>
Reviewed-by: Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: Kanna Rajagopal <kanna@cumulusnetworks.com>

Ticket: CM-10680, CM-10540
Reviewed By: CCR-4653
Testing Done: PTM smoke, BGP smoke and ptmd_test.py:TestMultipleAddrsIntfOspfBgp

1 files changed, 41 insertions, 0 deletions

diff --git a/zebra/zebra_ptm.c b/zebra/zebra_ptm.c
index 731bd3562..bf6afb021 100644
--- a/zebra/zebra_ptm.c
+++ b/zebra/zebra_ptm.c
@@ -48,6 +48,7 @@ const char ZEBRA_PTM_GET_STATUS_CMD[] = "get-status";
 const char ZEBRA_PTM_BFD_START_CMD[] = "start-bfd-sess";
 const char ZEBRA_PTM_BFD_STOP_CMD[] = "stop-bfd-sess";
 const char ZEBRA_PTM_BFD_CLIENT_REG_CMD[] = "reg-bfd-client";
+const char ZEBRA_PTM_BFD_CLIENT_DEREG_CMD[] = "dereg-bfd-client";
 
 const char ZEBRA_PTM_CMD_STR[] = "cmd";
 const char ZEBRA_PTM_CMD_STATUS_STR[] = "cmd_status";
@@ -1001,6 +1002,46 @@ zebra_ptm_bfd_client_register (struct zserv *client, int sock, u_short length)
   return 0;
 }
 
+/* BFD client deregister */
+void
+zebra_ptm_bfd_client_deregister (struct zserv *client)
+{
+  void *out_ctxt;
+  char tmp_buf[64];
+  int data_len = ZEBRA_PTM_SEND_MAX_SOCKBUF;
+
+  if (client->proto != ZEBRA_ROUTE_OSPF && client->proto != ZEBRA_ROUTE_BGP
+      && client->proto != ZEBRA_ROUTE_OSPF6)
+    return;
+
+  if (IS_ZEBRA_DEBUG_EVENT)
+    zlog_debug("bfd_client_deregister msg for client %s",
+                zebra_route_string(client->proto));
+
+  if (ptm_cb.ptm_sock == -1)
+    {
+      ptm_cb.t_timer = thread_add_timer (zebrad.master, zebra_ptm_connect,
+                                             NULL, ptm_cb.reconnect_time);
+      return;
+    }
+
+  ptm_lib_init_msg(ptm_hdl, 0, PTMLIB_MSG_TYPE_CMD, NULL, &out_ctxt);
+
+  sprintf(tmp_buf, "%s", ZEBRA_PTM_BFD_CLIENT_DEREG_CMD);
+  ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_CMD_STR, tmp_buf);
+
+  sprintf(tmp_buf, "%s", zebra_route_string(client->proto));
+  ptm_lib_append_msg(ptm_hdl, out_ctxt, ZEBRA_PTM_BFD_CLIENT_FIELD,
+                      tmp_buf);
+
+  ptm_lib_complete_msg(ptm_hdl, out_ctxt, ptm_cb.out_data, &data_len);
+
+  if (IS_ZEBRA_DEBUG_SEND)
+    zlog_debug ("%s: Sent message (%d) %s", __func__, data_len,
+                  ptm_cb.out_data);
+  zebra_ptm_send_message(ptm_cb.out_data, data_len);
+}
+
 int
 zebra_ptm_get_enable_state(void)
 {