zebra: optionally use protobuf with FPM

Change zebra so that it can optionally use protobuf serialization when
communicating with a Forwarding Plane Manager component.

  * zebra/main.c

    Add the --fpm-format/-F command line option. This allows the user
    to control the format (protbuf|netlink) that is used to
    communicate with the FPM.

  * zebra/zebra_fpm.c

    - zebra_init_msg_format(),

      This new function is invoked on process startup to determine the
      FPM format that should be used.

    - zfpm_init()

      Change to accept any 'FPM message format' specified by the user
      (via the new command line flag).

    - zebra_encode_route()

      Tweak to use the selected FPM format.

  * zebra_fpm_protobuf.c

    New code to build protobuf messages to be sent to the FPM.

  * zebra/Makefile.am

    - Include common.am

    - Build new file zebra_fpm_protobuf.c when protobuf is available.

    - Link with the fpm_pb library.

Signed-off-by: Avneesh Sachdev <avneesh@sproute.com>

1 files changed, 311 insertions, 0 deletions

diff --git a/zebra/zebra_fpm_protobuf.c b/zebra/zebra_fpm_protobuf.c
new file mode 100644
index 000000000..beef310b1
--- /dev/null
+++ b/zebra/zebra_fpm_protobuf.c
@@ -0,0 +1,311 @@
+/*
+ * zebra_fpm_protobuf.c
+ *
+ * @copyright Copyright (C) 2016 Sproute Networks, Inc.
+ *
+ * @author Avneesh Sachdev <avneesh@sproute.com>
+ *
+ * This file is part of Quagga.
+ *
+ * Quagga 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, or (at your option) any
+ * later version.
+ *
+ * Quagga 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 Quagga; see the file COPYING.  If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+#include <zebra.h>
+
+#include "log.h"
+#include "rib.h"
+
+#include "qpb/qpb.pb-c.h"
+#include "qpb/qpb.h"
+#include "qpb/qpb_allocator.h"
+#include "qpb/linear_allocator.h"
+#include "fpm/fpm_pb.h"
+
+#include "zebra_fpm_private.h"
+
+/*
+ * create_delete_route_message
+ */
+static Fpm__DeleteRoute *
+create_delete_route_message (qpb_allocator_t *allocator, rib_dest_t *dest,
+			     struct rib *rib)
+{
+  Fpm__DeleteRoute *msg;
+
+  msg = QPB_ALLOC(allocator, typeof(*msg));
+  if (!msg) {
+    assert(0);
+    return NULL;
+  }
+
+  fpm__delete_route__init(msg);
+  msg->vrf_id = rib_dest_vrf(dest)->vrf_id;
+
+  qpb_address_family_set(&msg->address_family, rib_dest_af(dest));
+
+  /*
+   * XXX Hardcode subaddress family for now.
+   */
+  msg->sub_address_family = QPB__SUB_ADDRESS_FAMILY__UNICAST;
+  msg->key = fpm_route_key_create (allocator, rib_dest_prefix(dest));
+  if (!msg->key) {
+    assert(0);
+    return NULL;
+  }
+
+  return msg;
+}
+
+/*
+ * add_nexthop
+ */
+static inline int
+add_nexthop (qpb_allocator_t *allocator, Fpm__AddRoute *msg, rib_dest_t *dest,
+	     struct nexthop *nexthop)
+{
+  uint32_t if_index;
+  union g_addr *gateway, *src;
+
+  gateway = src = NULL;
+
+  if_index = nexthop->ifindex;
+
+  if (nexthop->type == NEXTHOP_TYPE_IPV4
+      || nexthop->type == NEXTHOP_TYPE_IPV4_IFINDEX)
+    {
+      gateway = &nexthop->gate;
+      if (nexthop->src.ipv4.s_addr)
+	src = &nexthop->src;
+    }
+
+  if (nexthop->type == NEXTHOP_TYPE_IPV6
+      || nexthop->type == NEXTHOP_TYPE_IPV6_IFNAME
+      || nexthop->type == NEXTHOP_TYPE_IPV6_IFINDEX)
+    {
+      gateway = &nexthop->gate;
+    }
+
+  if (nexthop->type == NEXTHOP_TYPE_IFINDEX
+      || nexthop->type == NEXTHOP_TYPE_IFNAME)
+    {
+      if (nexthop->src.ipv4.s_addr)
+	src = &nexthop->src;
+    }
+
+  if (!gateway && if_index == 0)
+    return 0;
+
+  /*
+   * We have a valid nexthop.
+   */
+  {
+    Fpm__Nexthop *pb_nh;
+    pb_nh = QPB_ALLOC(allocator, typeof(*pb_nh));
+    if (!pb_nh) {
+      assert(0);
+      return 0;
+    }
+
+    fpm__nexthop__init(pb_nh);
+
+    if (if_index != 0) {
+      pb_nh->if_id = qpb_if_identifier_create (allocator, if_index);
+    }
+
+    if (gateway) {
+      pb_nh->address = qpb_l3_address_create (allocator, gateway,
+					      rib_dest_af(dest));
+    }
+
+    msg->nexthops[msg->n_nexthops++] = pb_nh;
+  }
+
+  // TODO: Use src.
+
+  return 1;
+}
+
+/*
+ * create_add_route_message
+ */
+static Fpm__AddRoute *
+create_add_route_message (qpb_allocator_t *allocator, rib_dest_t *dest,
+			  struct rib *rib)
+{
+  Fpm__AddRoute *msg;
+  int discard;
+  struct nexthop *nexthop, *tnexthop;
+  int recursing;
+  uint num_nhs, u;
+  struct nexthop *nexthops[MAX (MULTIPATH_NUM, 64)];
+
+  msg = QPB_ALLOC(allocator, typeof(*msg));
+  if (!msg) {
+    assert(0);
+    return NULL;
+  }
+
+  fpm__add_route__init(msg);
+
+  msg->vrf_id = rib_dest_vrf(dest)->vrf_id;
+
+  qpb_address_family_set (&msg->address_family, rib_dest_af(dest));
+
+  /*
+   * XXX Hardcode subaddress family for now.
+   */
+  msg->sub_address_family = QPB__SUB_ADDRESS_FAMILY__UNICAST;
+  msg->key = fpm_route_key_create (allocator, rib_dest_prefix(dest));
+  qpb_protocol_set (&msg->protocol, rib->type);
+
+  if ((rib->flags & ZEBRA_FLAG_BLACKHOLE) || (rib->flags & ZEBRA_FLAG_REJECT))
+    discard = 1;
+  else
+    discard = 0;
+
+  if (discard)
+    {
+      if (rib->flags & ZEBRA_FLAG_BLACKHOLE) {
+	msg->route_type = FPM__ROUTE_TYPE__BLACKHOLE;
+      } else if (rib->flags & ZEBRA_FLAG_REJECT) {
+	msg->route_type = FPM__ROUTE_TYPE__UNREACHABLE;
+      } else {
+	assert (0);
+      }
+      return msg;
+    }
+  else {
+    msg->route_type = FPM__ROUTE_TYPE__NORMAL;
+  }
+
+  msg->metric = rib->metric;
+
+  /*
+   * Figure out the set of nexthops to be added to the message.
+   */
+  num_nhs = 0;
+  for (ALL_NEXTHOPS_RO (rib->nexthop, nexthop, tnexthop, recursing))
+    {
+      if (MULTIPATH_NUM != 0 && num_nhs >= MULTIPATH_NUM)
+        break;
+
+      if (num_nhs >= ZEBRA_NUM_OF(nexthops))
+	break;
+
+      if (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_RECURSIVE))
+        continue;
+
+      if (!CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE))
+	continue;
+
+      nexthops[num_nhs] = nexthop;
+      num_nhs++;
+    }
+
+  if (!num_nhs) {
+    zfpm_debug ("netlink_encode_route(): No useful nexthop.");
+    assert(0);
+    return NULL;
+  }
+
+  /*
+   * And add them to the message.
+   */
+  if (!(msg->nexthops = qpb_alloc_ptr_array(allocator, num_nhs))) {
+    assert(0);
+    return NULL;
+  }
+
+  msg->n_nexthops = 0;
+  for (u = 0; u < num_nhs; u++) {
+    if (!add_nexthop(allocator, msg, dest, nexthops[u])) {
+      assert(0);
+      return NULL;
+    }
+  }
+
+  assert(msg->n_nexthops == num_nhs);
+
+  return msg;
+}
+
+/*
+ * create_route_message
+ */
+static Fpm__Message *
+create_route_message (qpb_allocator_t *allocator, rib_dest_t *dest,
+		      struct rib *rib)
+{
+  Fpm__Message *msg;
+
+  msg = QPB_ALLOC(allocator, typeof(*msg));
+  if (!msg) {
+    assert(0);
+    return NULL;
+  }
+
+  fpm__message__init(msg);
+
+  if (!rib) {
+    msg->type = FPM__MESSAGE__TYPE__DELETE_ROUTE;
+    msg->delete_route = create_delete_route_message(allocator, dest, rib);
+    if (!msg->delete_route) {
+      assert(0);
+      return NULL;
+    }
+    return msg;
+  }
+
+  msg->type = FPM__MESSAGE__TYPE__ADD_ROUTE;
+  msg->add_route = create_add_route_message(allocator, dest, rib);
+  if (!msg->add_route) {
+    assert(0);
+    return NULL;
+  }
+
+  return msg;
+}
+
+/*
+ * zfpm_protobuf_encode_route
+ *
+ * Create a protobuf message corresponding to the given route in the
+ * given buffer space.
+ *
+ * Returns the number of bytes written to the buffer. 0 or a negative
+ * value indicates an error.
+ */
+int
+zfpm_protobuf_encode_route (rib_dest_t *dest, struct rib *rib,
+			    uint8_t *in_buf, size_t in_buf_len)
+{
+  Fpm__Message *msg;
+  QPB_DECLARE_STACK_ALLOCATOR (allocator, 4096);
+  size_t len;
+
+  QPB_INIT_STACK_ALLOCATOR (allocator);
+
+  msg = create_route_message(&allocator, dest, rib);
+  if (!msg) {
+    assert(0);
+    return 0;
+  }
+
+  len = fpm__message__pack(msg, (uint8_t *) in_buf);
+  assert(len <= in_buf_len);
+
+  QPB_RESET_STACK_ALLOCATOR (allocator);
+  return len;
+}