gre: Tunnel encap/decap flags

Type: feature

common funcitons across IP-in-IP and GRE tunnels for encap/decap
functions

Signed-off-by: Neale Ranns <nranns@cisco.com>
Change-Id: I325b66824878d843af167adfe5a7a96b0ab90566

5 files changed, 123 insertions, 17 deletions

diff --git a/src/vnet/gre/gre.api b/src/vnet/gre/gre.api
index 0a98178ca87..fb78b47f3aa 100644
--- a/src/vnet/gre/gre.api
+++ b/src/vnet/gre/gre.api
@@ -34,6 +34,8 @@ enum gre_tunnel_type : u8
     @param context - sender context, to match reply w/ request
     @param tunnel_type - 0: L3, 1: TEB, 2: ERSPAN
     @param instance - optional unique custom device instance, else ~0.
+    @param mode - P2P or P2MP
+    @param flags - to control encap/decap behaviour
     @param src - Source IP address
     @param dst - Destination IP address, can be multicast
     @param outer_table_id - Encap FIB table ID
@@ -44,6 +46,7 @@ typedef gre_tunnel
 {
   vl_api_gre_tunnel_type_t type;
   vl_api_tunnel_mode_t mode;
+  vl_api_tunnel_encap_decap_flags_t flags;
   u16 session_id;
   u32 instance;
   u32 outer_table_id;
diff --git a/src/vnet/gre/gre.c b/src/vnet/gre/gre.c
index 2b95d99148a..f1bc6946416 100644
--- a/src/vnet/gre/gre.c
+++ b/src/vnet/gre/gre.c
@@ -18,6 +18,7 @@
 #include <vnet/vnet.h>
 #include <vnet/gre/gre.h>
 #include <vnet/adj/adj_midchain.h>
+#include <vnet/tunnel/tunnel_dp.h>
 
 extern gre_main_t gre_main;
 
@@ -274,11 +275,45 @@ gre_build_rewrite (vnet_main_t * vnm,
   return (rewrite);
 }
 
-#define is_v4_packet(_h) ((*(u8*) _h) & 0xF0) == 0x40
+static void
+gre44_fixup (vlib_main_t * vm,
+	     const ip_adjacency_t * adj, vlib_buffer_t * b0, const void *data)
+{
+  tunnel_encap_decap_flags_t flags;
+  ip4_and_gre_header_t *ip0;
+
+  ip0 = vlib_buffer_get_current (b0);
+  flags = pointer_to_uword (data);
+
+  /* Fixup the checksum and len fields in the GRE tunnel encap
+   * that was applied at the midchain node */
+  ip0->ip4.length =
+    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
+  tunnel_encap_fixup_4o4 (flags, (ip4_header_t *) (ip0 + 1), &ip0->ip4);
+  ip0->ip4.checksum = ip4_header_checksum (&ip0->ip4);
+}
 
 static void
-gre4_fixup (vlib_main_t * vm,
-	    const ip_adjacency_t * adj, vlib_buffer_t * b0, const void *data)
+gre64_fixup (vlib_main_t * vm,
+	     const ip_adjacency_t * adj, vlib_buffer_t * b0, const void *data)
+{
+  tunnel_encap_decap_flags_t flags;
+  ip4_and_gre_header_t *ip0;
+
+  ip0 = vlib_buffer_get_current (b0);
+  flags = pointer_to_uword (data);
+
+  /* Fixup the checksum and len fields in the GRE tunnel encap
+   * that was applied at the midchain node */
+  ip0->ip4.length =
+    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
+  tunnel_encap_fixup_6o4 (flags, (ip6_header_t *) (ip0 + 1), &ip0->ip4);
+  ip0->ip4.checksum = ip4_header_checksum (&ip0->ip4);
+}
+
+static void
+grex4_fixup (vlib_main_t * vm,
+	     const ip_adjacency_t * adj, vlib_buffer_t * b0, const void *data)
 {
   ip4_header_t *ip0;
 
@@ -291,8 +326,44 @@ gre4_fixup (vlib_main_t * vm,
 }
 
 static void
-gre6_fixup (vlib_main_t * vm,
-	    const ip_adjacency_t * adj, vlib_buffer_t * b0, const void *data)
+gre46_fixup (vlib_main_t * vm,
+	     const ip_adjacency_t * adj, vlib_buffer_t * b0, const void *data)
+{
+  tunnel_encap_decap_flags_t flags;
+  ip6_and_gre_header_t *ip0;
+
+  ip0 = vlib_buffer_get_current (b0);
+  flags = pointer_to_uword (data);
+
+  /* Fixup the payload length field in the GRE tunnel encap that was applied
+   * at the midchain node */
+  ip0->ip6.payload_length =
+    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0) -
+			  sizeof (*ip0));
+  tunnel_encap_fixup_4o6 (flags, (ip4_header_t *) (ip0 + 1), &ip0->ip6);
+}
+
+static void
+gre66_fixup (vlib_main_t * vm,
+	     const ip_adjacency_t * adj, vlib_buffer_t * b0, const void *data)
+{
+  tunnel_encap_decap_flags_t flags;
+  ip6_and_gre_header_t *ip0;
+
+  ip0 = vlib_buffer_get_current (b0);
+  flags = pointer_to_uword (data);
+
+  /* Fixup the payload length field in the GRE tunnel encap that was applied
+   * at the midchain node */
+  ip0->ip6.payload_length =
+    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0) -
+			  sizeof (*ip0));
+  tunnel_encap_fixup_6o6 (flags, (ip6_header_t *) (ip0 + 1), &ip0->ip6);
+}
+
+static void
+grex6_fixup (vlib_main_t * vm,
+	     const ip_adjacency_t * adj, vlib_buffer_t * b0, const void *data)
 {
   ip6_header_t *ip0;
 
@@ -305,25 +376,49 @@ gre6_fixup (vlib_main_t * vm,
 			  sizeof (*ip0));
 }
 
+/**
+ * return the appropriate fixup function given the overlay (link-type) and
+ * underlay (fproto) combination
+ */
+static adj_midchain_fixup_t
+gre_get_fixup (fib_protocol_t fproto, vnet_link_t lt)
+{
+  if (fproto == FIB_PROTOCOL_IP6 && lt == VNET_LINK_IP6)
+    return (gre66_fixup);
+  if (fproto == FIB_PROTOCOL_IP6 && lt == VNET_LINK_IP4)
+    return (gre46_fixup);
+  if (fproto == FIB_PROTOCOL_IP4 && lt == VNET_LINK_IP6)
+    return (gre64_fixup);
+  if (fproto == FIB_PROTOCOL_IP4 && lt == VNET_LINK_IP4)
+    return (gre44_fixup);
+  if (fproto == FIB_PROTOCOL_IP6 && lt == VNET_LINK_ETHERNET)
+    return (grex6_fixup);
+  if (fproto == FIB_PROTOCOL_IP4 && lt == VNET_LINK_ETHERNET)
+    return (grex4_fixup);
+
+  ASSERT (0);
+  return (gre44_fixup);
+}
+
 void
 gre_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
 {
   gre_main_t *gm = &gre_main;
   gre_tunnel_t *t;
   adj_flags_t af;
-  u8 is_ipv6;
   u32 ti;
 
   ti = gm->tunnel_index_by_sw_if_index[sw_if_index];
   t = pool_elt_at_index (gm->tunnels, ti);
-  is_ipv6 = t->tunnel_dst.fp_proto == FIB_PROTOCOL_IP6 ? 1 : 0;
   af = ADJ_FLAG_MIDCHAIN_IP_STACK;
 
   if (VNET_LINK_ETHERNET == adj_get_link_type (ai))
     af |= ADJ_FLAG_MIDCHAIN_NO_COUNT;
 
   adj_nbr_midchain_update_rewrite
-    (ai, !is_ipv6 ? gre4_fixup : gre6_fixup, NULL, af,
+    (ai, gre_get_fixup (t->tunnel_dst.fp_proto,
+			adj_get_link_type (ai)),
+     uword_to_pointer (t->flags, void *), af,
      gre_build_rewrite (vnm, sw_if_index, adj_get_link_type (ai),
 			&t->tunnel_dst.fp_addr));
 
@@ -334,13 +429,12 @@ adj_walk_rc_t
 mgre_mk_complete_walk (adj_index_t ai, void *data)
 {
   mgre_walk_ctx_t *ctx = data;
-  adj_midchain_fixup_t f;
-
-  f = (ctx->t->tunnel_dst.fp_proto == FIB_PROTOCOL_IP4 ?
-       gre4_fixup : gre6_fixup);
 
   adj_nbr_midchain_update_rewrite
-    (ai, f, NULL, ADJ_FLAG_MIDCHAIN_IP_STACK,
+    (ai, gre_get_fixup (ctx->t->tunnel_dst.fp_proto,
+			adj_get_link_type (ai)),
+     uword_to_pointer (ctx->t->flags, void *),
+     ADJ_FLAG_MIDCHAIN_IP_STACK,
      gre_build_rewrite (vnet_get_main (),
 			ctx->t->sw_if_index,
 			adj_get_link_type (ai),
@@ -355,11 +449,10 @@ adj_walk_rc_t
 mgre_mk_incomplete_walk (adj_index_t ai, void *data)
 {
   gre_tunnel_t *t = data;
-  adj_midchain_fixup_t f;
-
-  f = (t->tunnel_dst.fp_proto == FIB_PROTOCOL_IP4 ? gre4_fixup : gre6_fixup);
 
-  adj_nbr_midchain_update_rewrite (ai, f, NULL, ADJ_FLAG_NONE, NULL);
+  adj_nbr_midchain_update_rewrite (ai, gre_get_fixup (t->tunnel_dst.fp_proto,
+						      adj_get_link_type (ai)),
+				   NULL, ADJ_FLAG_NONE, NULL);
 
   adj_midchain_delegate_unstack (ai);
 
diff --git a/src/vnet/gre/gre.h b/src/vnet/gre/gre.h
index 70f624122ce..0cc60b87eeb 100644
--- a/src/vnet/gre/gre.h
+++ b/src/vnet/gre/gre.h
@@ -206,6 +206,7 @@ typedef struct
   u32 sw_if_index;
   gre_tunnel_type_t type;
   tunnel_mode_t mode;
+  tunnel_encap_decap_flags_t flags;
 
   /**
    * an L2 tunnel always rquires an L2 midchain. cache here for DP.
@@ -368,6 +369,7 @@ typedef struct
   ip46_address_t src, dst;
   u32 outer_table_id;
   u16 session_id;
+  tunnel_encap_decap_flags_t flags;
 } vnet_gre_tunnel_add_del_args_t;
 
 extern int vnet_gre_tunnel_add_del (vnet_gre_tunnel_add_del_args_t * a,
diff --git a/src/vnet/gre/gre_api.c b/src/vnet/gre/gre_api.c
index 619b5fc233c..934fc661b47 100644
--- a/src/vnet/gre/gre_api.c
+++ b/src/vnet/gre/gre_api.c
@@ -89,6 +89,7 @@ static void vl_api_gre_tunnel_add_del_t_handler
 {
   vnet_gre_tunnel_add_del_args_t _a = { }, *a = &_a;
   vl_api_gre_tunnel_add_del_reply_t *rmp;
+  tunnel_encap_decap_flags_t flags;
   u32 sw_if_index = ~0;
   ip46_type_t itype[2];
   int rv = 0;
@@ -118,11 +119,17 @@ static void vl_api_gre_tunnel_add_del_t_handler
   if (rv)
     goto out;
 
+  rv = tunnel_encap_decap_flags_decode (mp->tunnel.flags, &flags);
+
+  if (rv)
+    goto out;
+
   a->is_add = mp->is_add;
   a->is_ipv6 = (itype[0] == IP46_TYPE_IP6);
   a->instance = ntohl (mp->tunnel.instance);
   a->session_id = ntohs (mp->tunnel.session_id);
   a->outer_table_id = ntohl (mp->tunnel.outer_table_id);
+  a->flags = flags;
 
   rv = vnet_gre_tunnel_add_del (a, &sw_if_index);
 
diff --git a/src/vnet/gre/interface.c b/src/vnet/gre/interface.c
index 178b080a73b..553c89aeb51 100644
--- a/src/vnet/gre/interface.c
+++ b/src/vnet/gre/interface.c
@@ -346,6 +346,7 @@ vnet_gre_tunnel_add (vnet_gre_tunnel_add_del_args_t * a,
 
   t->type = a->type;
   t->mode = a->mode;
+  t->flags = a->flags;
   if (t->type == GRE_TUNNEL_TYPE_ERSPAN)
     t->session_id = a->session_id;