BGP: Add support for flowspec (RFC 5575)

1 files changed, 225 insertions, 0 deletions

diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c
index 66561ee4..1ae75a64 100644
--- a/proto/bgp/packets.c
+++ b/proto/bgp/packets.c
@@ -20,6 +20,7 @@
 #include "nest/mrtdump.h"
 #include "conf/conf.h"
 #include "lib/unaligned.h"
+#include "lib/flowspec.h"
 #include "lib/socket.h"
 
 #include "nest/cli.h"
@@ -793,6 +794,26 @@ bgp_update_next_hop_ip(struct bgp_export_state *s, eattr *a, ea_list **to)
     WITHDRAW(BAD_NEXT_HOP);
 }
 
+static uint
+bgp_encode_next_hop_none(struct bgp_write_state *s UNUSED, eattr *a UNUSED, byte *buf UNUSED, uint size UNUSED)
+{
+  // FIXME
+  return 0;
+}
+
+static void
+bgp_decode_next_hop_none(struct bgp_parse_state *s UNUSED, byte *data UNUSED, uint len UNUSED, rta *a UNUSED)
+{
+  // FIXME
+  return;
+}
+
+static void
+bgp_update_next_hop_none(struct bgp_export_state *s UNUSED, eattr *a UNUSED, ea_list **to UNUSED)
+{
+  // FIXME
+}
+
 
 /*
  *	UPDATE
@@ -1066,6 +1087,190 @@ bgp_decode_next_hop_ip6(struct bgp_parse_state *s, byte *data, uint len, rta *a)
 }
 
 
+static uint
+bgp_encode_nlri_flow4(struct bgp_write_state *s, struct bgp_bucket *buck, byte *buf, uint size)
+{
+  byte *pos = buf;
+
+  while (!EMPTY_LIST(buck->prefixes) && (size >= 4))
+  {
+    struct bgp_prefix *px = HEAD(buck->prefixes);
+    struct net_addr_flow4 *net = (void *) px->net;
+    uint flen = net->length - sizeof(net_addr_flow4);
+
+    /* Encode path ID */
+    if (s->add_path)
+    {
+      put_u32(pos, px->path_id);
+      ADVANCE(pos, size, 4);
+    }
+
+    if (flen > size)
+      break;
+
+    /* Copy whole flow data including length */
+    memcpy(pos, net->data, flen);
+    ADVANCE(pos, size, flen);
+
+    bgp_free_prefix(s->channel, px);
+  }
+
+  return pos - buf;
+}
+
+static void
+bgp_decode_nlri_flow4(struct bgp_parse_state *s, byte *pos, uint len, rta *a)
+{
+  while (len)
+  {
+    u32 path_id = 0;
+
+    /* Decode path ID */
+    if (s->add_path)
+    {
+      if (len < 4)
+	bgp_parse_error(s, 1);
+
+      path_id = get_u32(pos);
+      ADVANCE(pos, len, 4);
+    }
+
+    if (len < 2)
+      bgp_parse_error(s, 1);
+
+    /* Decode flow length */
+    uint hlen = flow_hdr_length(pos);
+    uint dlen = flow_read_length(pos);
+    uint flen = hlen + dlen;
+    byte *data = pos + hlen;
+
+    if (len < flen)
+      bgp_parse_error(s, 1);
+
+    /* Validate flow data */
+    enum flow_validated_state r = flow4_validate(data, dlen);
+    if (r != FLOW_ST_VALID)
+    {
+      log(L_REMOTE "%s: Invalid flow route: %s", s->proto->p.name, flow_validated_state_str(r));
+      bgp_parse_error(s, 1);
+    }
+
+    if (data[0] != FLOW_TYPE_DST_PREFIX)
+    {
+      log(L_REMOTE "%s: No dst prefix at first pos", s->proto->p.name);
+      bgp_parse_error(s, 1);
+    }
+
+    /* Decode dst prefix */
+    ip4_addr px = IP4_NONE;
+    uint pxlen = data[1];
+
+    // FIXME: Use some generic function
+    memcpy(&px, data, BYTES(pxlen));
+    px = ip4_and(px, ip4_mkmask(pxlen));
+
+    /* Prepare the flow */
+    net_addr *n = alloca(sizeof(struct net_addr_flow4) + flen);
+    net_fill_flow4(n, px, pxlen, pos, flen);
+    ADVANCE(pos, len, flen);
+
+    bgp_rte_update(s, n, path_id, a);
+  }
+}
+
+
+static uint
+bgp_encode_nlri_flow6(struct bgp_write_state *s, struct bgp_bucket *buck, byte *buf, uint size)
+{
+  byte *pos = buf;
+
+  while (!EMPTY_LIST(buck->prefixes) && (size >= 4))
+  {
+    struct bgp_prefix *px = HEAD(buck->prefixes);
+    struct net_addr_flow6 *net = (void *) px->net;
+    uint flen = net->length - sizeof(net_addr_flow6);
+
+    /* Encode path ID */
+    if (s->add_path)
+    {
+      put_u32(pos, px->path_id);
+      ADVANCE(pos, size, 4);
+    }
+
+    if (flen > size)
+      break;
+
+    /* Copy whole flow data including length */
+    memcpy(pos, net->data, flen);
+    ADVANCE(pos, size, flen);
+
+    bgp_free_prefix(s->channel, px);
+  }
+
+  return pos - buf;
+}
+
+static void
+bgp_decode_nlri_flow6(struct bgp_parse_state *s, byte *pos, uint len, rta *a)
+{
+  while (len)
+  {
+    u32 path_id = 0;
+
+    /* Decode path ID */
+    if (s->add_path)
+    {
+      if (len < 4)
+	bgp_parse_error(s, 1);
+
+      path_id = get_u32(pos);
+      ADVANCE(pos, len, 4);
+    }
+
+    if (len < 2)
+      bgp_parse_error(s, 1);
+
+    /* Decode flow length */
+    uint hlen = flow_hdr_length(pos);
+    uint dlen = flow_read_length(pos);
+    uint flen = hlen + dlen;
+    byte *data = pos + hlen;
+
+    if (len < flen)
+      bgp_parse_error(s, 1);
+
+    /* Validate flow data */
+    enum flow_validated_state r = flow6_validate(data, dlen);
+    if (r != FLOW_ST_VALID)
+    {
+      log(L_REMOTE "%s: Invalid flow route: %s", s->proto->p.name, flow_validated_state_str(r));
+      bgp_parse_error(s, 1);
+    }
+
+    if (data[0] != FLOW_TYPE_DST_PREFIX)
+    {
+      log(L_REMOTE "%s: No dst prefix at first pos", s->proto->p.name);
+      bgp_parse_error(s, 1);
+    }
+
+    /* Decode dst prefix */
+    ip6_addr px = IP6_NONE;
+    uint pxlen = data[1];
+
+    // FIXME: Use some generic function
+    memcpy(&px, data, BYTES(pxlen));
+    px = ip6_and(px, ip6_mkmask(pxlen));
+
+    /* Prepare the flow */
+    net_addr *n = alloca(sizeof(struct net_addr_flow6) + flen);
+    net_fill_flow6(n, px, pxlen, pos, flen);
+    ADVANCE(pos, len, flen);
+
+    bgp_rte_update(s, n, path_id, a);
+  }
+}
+
+
 static const struct bgp_af_desc bgp_af_table[] = {
   {
     .afi = BGP_AF_IPV4,
@@ -1088,6 +1293,16 @@ static const struct bgp_af_desc bgp_af_table[] = {
     .update_next_hop = bgp_update_next_hop_ip,
   },
   {
+    .afi = BGP_AF_FLOW4,
+    .net = NET_FLOW4,
+    .name = "flow4",
+    .encode_nlri = bgp_encode_nlri_flow4,
+    .decode_nlri = bgp_decode_nlri_flow4,
+    .encode_next_hop = bgp_encode_next_hop_none,
+    .decode_next_hop = bgp_decode_next_hop_none,
+    .update_next_hop = bgp_update_next_hop_none,
+  },
+  {
     .afi = BGP_AF_IPV6,
     .net = NET_IP6,
     .name = "ipv6",
@@ -1107,6 +1322,16 @@ static const struct bgp_af_desc bgp_af_table[] = {
     .decode_next_hop = bgp_decode_next_hop_ip6,
     .update_next_hop = bgp_update_next_hop_ip,
   },
+  {
+    .afi = BGP_AF_FLOW6,
+    .net = NET_FLOW6,
+    .name = "flow6",
+    .encode_nlri = bgp_encode_nlri_flow6,
+    .decode_nlri = bgp_decode_nlri_flow6,
+    .encode_next_hop = bgp_encode_next_hop_none,
+    .decode_next_hop = bgp_decode_next_hop_none,
+    .update_next_hop = bgp_update_next_hop_none,
+  },
 };
 
 const struct bgp_af_desc *