pimd: pim bfd support

All PIM Neighbors for a given pim interface is registered with
BFD.
Upon receiving BFD status down event, PIM Neighbor with BFD info is deleted.
Add pim bfd configuraiton (CLI) per interface, '[no] ip pim bfd'

Testing Done:
Configure BFD under PIM interface on all neighbor routers,
check bfd sessions up, remote end unconfigure BFD, results in BFD session down.
Previous state was UP to New state DOWN, results in PIM neighbor delete behind
that particular pim interface.
Pim-smoke Results:
Ran 94 tests in 7409.680s
FAILED (SKIP=8, failures=2)

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

1 files changed, 360 insertions, 0 deletions

diff --git a/pimd/pim_bfd.c b/pimd/pim_bfd.c
new file mode 100644
index 000000000..5c10df32e
--- /dev/null
+++ b/pimd/pim_bfd.c
@@ -0,0 +1,360 @@
+/*
+ * pim_bfd.c: PIM BFD handling routines
+ *
+ * Copyright (C) 2017 Cumulus Networks, Inc.
+ * Chirag Shah
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#include <zebra.h>
+
+#include "lib/json.h"
+#include "command.h"
+#include "vty.h"
+#include "zclient.h"
+
+#include "pim_cmd.h"
+#include "pim_vty.h"
+#include "pim_iface.h"
+#include "pim_bfd.h"
+#include "bfd.h"
+#include "pimd.h"
+#include "pim_zebra.h"
+
+/*
+ * pim_bfd_write_config - Write the interface BFD configuration.
+ */
+void
+pim_bfd_write_config (struct vty *vty, struct interface *ifp)
+{
+  struct pim_interface *pim_ifp = ifp->info;
+  struct bfd_info *bfd_info = NULL;
+
+  if (!pim_ifp)
+    return;
+  bfd_info = (struct bfd_info *) pim_ifp->bfd_info;
+  if (!bfd_info)
+    {
+      zlog_debug ("%s: interface %s bfd_info is NULL ", __PRETTY_FUNCTION__,
+                  ifp->name);
+      return;
+    }
+  if (CHECK_FLAG (bfd_info->flags, BFD_FLAG_PARAM_CFG))
+    vty_out (vty, " ip pim bfd %d %d %d%s",
+             bfd_info->detect_mult, bfd_info->required_min_rx,
+             bfd_info->desired_min_tx, VTY_NEWLINE);
+  else
+    vty_out (vty, " ip pim bfd%s", VTY_NEWLINE);
+}
+
+/*
+ * pim_bfd_show_info - Show BFD info structure
+ */
+void
+pim_bfd_show_info (struct vty *vty, void *bfd_info, json_object * json_obj,
+                   u_char use_json, int param_only)
+{
+  if (param_only)
+    bfd_show_param (vty, (struct bfd_info *) bfd_info, 1, 0, use_json,
+                    json_obj);
+  else
+    bfd_show_info (vty, (struct bfd_info *) bfd_info, 0, 1, use_json,
+                   json_obj);
+}
+
+/*
+ * pim_bfd_info_nbr_create - Create/update BFD information for a neighbor.
+ */
+void
+pim_bfd_info_nbr_create (struct pim_interface *pim_ifp,
+                         struct pim_neighbor *neigh)
+{
+  struct bfd_info *nbr_bfd_info = NULL;
+
+  /* Check if Pim Interface BFD is enabled */
+  if (!pim_ifp || !pim_ifp->bfd_info)
+    return;
+
+  if (!neigh->bfd_info)
+    neigh->bfd_info = bfd_info_create ();
+
+  if (!neigh->bfd_info)
+    return;
+  zlog_debug ("%s: bfd_info ", __PRETTY_FUNCTION__);
+
+  nbr_bfd_info = (struct bfd_info *) neigh->bfd_info;
+  nbr_bfd_info->detect_mult = pim_ifp->bfd_info->detect_mult;
+  nbr_bfd_info->desired_min_tx = pim_ifp->bfd_info->desired_min_tx;
+  nbr_bfd_info->required_min_rx = pim_ifp->bfd_info->required_min_rx;
+}
+
+/*
+ * pim_bfd_info_free - Free BFD info structure
+ */
+void
+pim_bfd_info_free (void **bfd_info)
+{
+  bfd_info_free ((struct bfd_info **) bfd_info);
+}
+
+static void
+pim_bfd_reg_dereg_nbr (struct pim_neighbor *nbr, int command)
+{
+  struct pim_interface *pim_ifp = NULL;
+  struct bfd_info *bfd_info = NULL;
+  struct zclient *zclient = NULL;
+
+  zclient = pim_zebra_zclient_get ();
+
+  if (!nbr)
+    return;
+  pim_ifp = nbr->interface->info;
+  bfd_info = (struct bfd_info *) pim_ifp->bfd_info;
+  if (!bfd_info)
+    return;
+  if (PIM_DEBUG_PIM_TRACE)
+    {
+      char str[INET_ADDRSTRLEN];
+      pim_inet4_dump ("<bfd_nbr?>", nbr->source_addr, str, sizeof (str));
+      zlog_debug ("%s Nbr %s %s with BFD", __PRETTY_FUNCTION__, str,
+              bfd_get_command_dbg_str (command));
+    }
+  bfd_peer_sendmsg (zclient, bfd_info, AF_INET,
+                    &nbr->source_addr, NULL, nbr->interface->name,
+                    0, 0, command, 0, VRF_DEFAULT);
+}
+
+/*
+ * pim_bfd_reg_dereg_all_nbr - Register/Deregister all neighbors associated
+ *                              with a interface with BFD through
+ *                              zebra for starting/stopping the monitoring of
+ *                              the neighbor rechahability.
+ */
+int
+pim_bfd_reg_dereg_all_nbr (struct interface *ifp, int command)
+{
+  struct pim_interface *pim_ifp = NULL;
+  struct listnode *node = NULL;
+  struct pim_neighbor *neigh = NULL;
+
+  pim_ifp = ifp->info;
+  if (!pim_ifp)
+    return -1;
+  if (!pim_ifp->bfd_info)
+    return -1;
+
+  for (ALL_LIST_ELEMENTS_RO (pim_ifp->pim_neighbor_list, node, neigh))
+    {
+      if (command != ZEBRA_BFD_DEST_DEREGISTER)
+        pim_bfd_info_nbr_create (pim_ifp, neigh);
+      else
+        bfd_info_free ((struct bfd_info **) &neigh->bfd_info);
+
+      pim_bfd_reg_dereg_nbr (neigh, command);
+    }
+
+  return 0;
+}
+
+/*
+ * pim_bfd_trigger_event - Neighbor is registered/deregistered with BFD when
+ *                          neighbor state is changed to/from 2way.
+ */
+void
+pim_bfd_trigger_event (struct pim_interface *pim_ifp, struct pim_neighbor *nbr, uint8_t nbr_up)
+{
+  if (nbr_up)
+    {
+      pim_bfd_info_nbr_create (pim_ifp, nbr);
+      pim_bfd_reg_dereg_nbr (nbr, ZEBRA_BFD_DEST_REGISTER);
+    }
+  else
+    {
+      pim_bfd_info_free ((void *)&nbr->bfd_info);
+      pim_bfd_reg_dereg_nbr (nbr, ZEBRA_BFD_DEST_DEREGISTER);
+    }
+}
+
+/*
+ * pim_bfd_if_param_set - Set the configured BFD paramter values for
+ *                         interface.
+ */
+void
+pim_bfd_if_param_set (struct interface *ifp, u_int32_t min_rx,
+                      u_int32_t min_tx, u_int8_t detect_mult, int defaults)
+{
+  struct pim_interface *pim_ifp = ifp->info;
+  int command = 0;
+
+  bfd_set_param ((struct bfd_info **) &(pim_ifp->bfd_info), min_rx, min_tx,
+                 detect_mult, defaults, &command);
+
+  if (pim_ifp->bfd_info)
+    {
+      if (PIM_DEBUG_PIM_TRACE)
+        zlog_debug ("%s: interface %s has bfd_info", __PRETTY_FUNCTION__,
+                    ifp->name);
+    }
+  if (command)
+    pim_bfd_reg_dereg_all_nbr (ifp, command);
+}
+
+
+/*
+ * pim_bfd_interface_dest_update - Find the neighbor for which the BFD status
+ *                                  has changed and bring down the neighbor
+ *                                  connectivity if the BFD status changed to
+ *                                  down.
+ */
+static int
+pim_bfd_interface_dest_update (int command, struct zclient *zclient,
+                               zebra_size_t length, vrf_id_t vrf_id)
+{
+  struct interface *ifp = NULL;
+  struct pim_interface *pim_ifp = NULL;
+  struct prefix p;
+  int status;
+  char msg[100];
+  int old_status;
+  struct bfd_info *bfd_info = NULL;
+  struct timeval tv;
+  struct listnode *neigh_node = NULL;
+  struct listnode *neigh_nextnode = NULL;
+  struct pim_neighbor *neigh = NULL;
+
+  ifp = bfd_get_peer_info (zclient->ibuf, &p, NULL, &status, vrf_id);
+
+  if ((ifp == NULL) || (p.family != AF_INET))
+    return 0;
+
+  pim_ifp = ifp->info;
+  if (!pim_ifp)
+    return 0;
+
+  if (!pim_ifp->bfd_info)
+    {
+      if (PIM_DEBUG_PIM_TRACE)
+        zlog_debug ("%s: pim interface %s BFD is disabled ", __PRETTY_FUNCTION__,
+                    ifp->name);
+      return 0;
+    }
+
+  if (PIM_DEBUG_PIM_TRACE)
+    {
+      char buf[PREFIX2STR_BUFFER];
+      prefix2str (&p, buf, sizeof (buf));
+      zlog_debug ("%s: interface %s bfd destination %s %s",
+                  __PRETTY_FUNCTION__, ifp->name, buf,
+                  bfd_get_status_str (status));
+    }
+
+  for (ALL_LIST_ELEMENTS (pim_ifp->pim_neighbor_list, neigh_node,
+                          neigh_nextnode, neigh))
+    {
+      bfd_info = (struct bfd_info *) neigh->bfd_info;
+      if (bfd_info->status == status)
+        {
+          if (PIM_DEBUG_PIM_TRACE)
+            {
+              char str[INET_ADDRSTRLEN];
+              pim_inet4_dump ("<nht_nbr?>", neigh->source_addr, str,
+                              sizeof (str));
+              zlog_debug ("%s: bfd status is same for nbr %s",
+                          __PRETTY_FUNCTION__, str);
+            }
+          continue;
+        }
+      old_status = bfd_info->status;
+      bfd_info->status = status;
+      monotime(&tv);
+      bfd_info->last_update = tv.tv_sec;
+
+      if (PIM_DEBUG_PIM_TRACE)
+        {
+          zlog_debug ("%s: status %s old_status %s", __PRETTY_FUNCTION__,
+                      bfd_get_status_str (status),
+                      bfd_get_status_str (old_status));
+        }
+      if ((status == BFD_STATUS_DOWN) && (old_status == BFD_STATUS_UP))
+        {
+          snprintf (msg, sizeof (msg), "BFD Session Expired");
+          pim_neighbor_delete (ifp, neigh, msg);
+        }
+    }
+  return 0;
+}
+
+/*
+ * pim_bfd_nbr_replay - Replay all the neighbors that have BFD enabled
+ *                       to zebra
+ */
+static int
+pim_bfd_nbr_replay (int command, struct zclient *zclient, zebra_size_t length,
+                    vrf_id_t vrf_id)
+{
+  struct interface *ifp = NULL;
+  struct pim_interface *pim_ifp = NULL;
+  struct pim_neighbor *neigh = NULL;
+  struct listnode *node;
+  struct listnode *neigh_node;
+  struct listnode *neigh_nextnode;
+
+  /* Send the client registration */
+  bfd_client_sendmsg (zclient, ZEBRA_BFD_CLIENT_REGISTER);
+
+  for (ALL_LIST_ELEMENTS_RO (vrf_iflist (VRF_DEFAULT), node, ifp))
+    {
+      pim_ifp = ifp->info;
+
+      if (!pim_ifp)
+        continue;
+
+      if (pim_ifp->pim_sock_fd < 0)
+        continue;
+
+      for (ALL_LIST_ELEMENTS (pim_ifp->pim_neighbor_list, neigh_node,
+                              neigh_nextnode, neigh))
+        {
+          if (!neigh->bfd_info)
+            continue;
+          if (PIM_DEBUG_PIM_TRACE)
+            {
+              char str[INET_ADDRSTRLEN];
+              pim_inet4_dump ("<bfd_nbr?>", neigh->source_addr, str,
+                              sizeof (str));
+              zlog_debug ("%s: Replaying Pim Neigh %s to BFD",
+                          __PRETTY_FUNCTION__, str);
+            }
+          pim_bfd_reg_dereg_nbr (neigh, ZEBRA_BFD_DEST_UPDATE);
+
+        }
+    }
+  return 0;
+}
+
+void
+pim_bfd_init (void)
+{
+  struct zclient *zclient = NULL;
+
+  zclient = pim_zebra_zclient_get ();
+
+  bfd_gbl_init ();
+
+  zclient->interface_bfd_dest_update = pim_bfd_interface_dest_update;
+  zclient->bfd_dest_replay = pim_bfd_nbr_replay;
+}