ipip: Support MPLS over IP

Type: feature

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: Ief1755131297afcaa14fe74fd8dd28c71a92fbe6

3 files changed, 102 insertions, 5 deletions

diff --git a/src/vnet/ipip/ipip.c b/src/vnet/ipip/ipip.c
index 357eb58f160..ca52142f5c6 100644
--- a/src/vnet/ipip/ipip.c
+++ b/src/vnet/ipip/ipip.c
@@ -93,6 +93,9 @@ ipip_build_rewrite (vnet_main_t * vnm, u32 sw_if_index,
 	case VNET_LINK_IP4:
 	  ip4->protocol = IP_PROTOCOL_IP_IN_IP;
 	  break;
+	case VNET_LINK_MPLS:
+	  ip4->protocol = IP_PROTOCOL_MPLS_IN_IP;
+	  break;
 	default:
 	  break;
 	}
@@ -121,6 +124,9 @@ ipip_build_rewrite (vnet_main_t * vnm, u32 sw_if_index,
 	case VNET_LINK_IP4:
 	  ip6->protocol = IP_PROTOCOL_IP_IN_IP;
 	  break;
+	case VNET_LINK_MPLS:
+	  ip6->protocol = IP_PROTOCOL_MPLS_IN_IP;
+	  break;
 	default:
 	  break;
 	}
@@ -202,6 +208,46 @@ ipip66_fixup (vlib_main_t * vm,
 }
 
 static void
+ipipm6_fixup (vlib_main_t *vm, const ip_adjacency_t *adj, vlib_buffer_t *b,
+	      const void *data)
+{
+  tunnel_encap_decap_flags_t flags;
+  ip6_header_t *ip6;
+
+  flags = pointer_to_uword (data);
+
+  /* Must set locally originated otherwise we're not allowed to
+     fragment the packet later and we'll get an unwanted hop-limt
+     decrement */
+  b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
+
+  ip6 = vlib_buffer_get_current (b);
+  ip6->payload_length =
+    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b) - sizeof (*ip6));
+  tunnel_encap_fixup_mplso6 (flags, (mpls_unicast_header_t *) (ip6 + 1), ip6);
+}
+
+static void
+ipipm4_fixup (vlib_main_t *vm, const ip_adjacency_t *adj, vlib_buffer_t *b,
+	      const void *data)
+{
+  tunnel_encap_decap_flags_t flags;
+  ip4_header_t *ip4;
+
+  flags = pointer_to_uword (data);
+
+  /* Must set locally originated otherwise we'll do a TTL decrement
+   * during ip4-rewrite */
+  b->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;
+
+  ip4 = vlib_buffer_get_current (b);
+  ip4->length =
+    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b) - sizeof (*ip4));
+  tunnel_encap_fixup_mplso4 (flags, (mpls_unicast_header_t *) (ip4 + 1), ip4);
+  ip4->checksum = ip4_header_checksum (ip4);
+}
+
+static void
 ipip_tunnel_stack (adj_index_t ai)
 {
   ip_adjacency_t *adj;
@@ -265,8 +311,12 @@ ipip_get_fixup (const ipip_tunnel_t * t, vnet_link_t lt, adj_flags_t * aflags)
     return (ipip66_fixup);
   if (t->transport == IPIP_TRANSPORT_IP6 && lt == VNET_LINK_IP4)
     return (ipip46_fixup);
+  if (t->transport == IPIP_TRANSPORT_IP6 && lt == VNET_LINK_MPLS)
+    return (ipipm6_fixup);
   if (t->transport == IPIP_TRANSPORT_IP4 && lt == VNET_LINK_IP6)
     return (ipip64_fixup);
+  if (t->transport == IPIP_TRANSPORT_IP4 && lt == VNET_LINK_MPLS)
+    return (ipipm4_fixup);
   if (t->transport == IPIP_TRANSPORT_IP4 && lt == VNET_LINK_IP4)
     {
       *aflags = *aflags | ADJ_FLAG_MIDCHAIN_FIXUP_IP4O4_HDR;
@@ -756,12 +806,14 @@ ipip_add_tunnel (ipip_transport_t transport,
   if (t->transport == IPIP_TRANSPORT_IP6 && !gm->ip6_protocol_registered)
     {
       ip6_register_protocol (IP_PROTOCOL_IP_IN_IP, ipip6_input_node.index);
+      ip6_register_protocol (IP_PROTOCOL_MPLS_IN_IP, ipip6_input_node.index);
       ip6_register_protocol (IP_PROTOCOL_IPV6, ipip6_input_node.index);
       gm->ip6_protocol_registered = true;
     }
   else if (t->transport == IPIP_TRANSPORT_IP4 && !gm->ip4_protocol_registered)
     {
       ip4_register_protocol (IP_PROTOCOL_IP_IN_IP, ipip4_input_node.index);
+      ip4_register_protocol (IP_PROTOCOL_MPLS_IN_IP, ipip4_input_node.index);
       ip4_register_protocol (IP_PROTOCOL_IPV6, ipip4_input_node.index);
       gm->ip4_protocol_registered = true;
     }
diff --git a/src/vnet/ipip/node.c b/src/vnet/ipip/node.c
index baaeee863fc..b008a21a20f 100644
--- a/src/vnet/ipip/node.c
+++ b/src/vnet/ipip/node.c
@@ -22,11 +22,12 @@
 #include <vnet/tunnel/tunnel_dp.h>
 #include <vppinfra/sparse_vec.h>
 
-#define foreach_ipip_input_next                                                \
-  _(PUNT, "error-punt")                                                        \
-  _(DROP, "error-drop")                                                        \
-  _(IP4_INPUT, "ip4-input")                                                    \
-  _(IP6_INPUT, "ip6-input")
+#define foreach_ipip_input_next                                               \
+  _ (PUNT, "error-punt")                                                      \
+  _ (DROP, "error-drop")                                                      \
+  _ (IP4_INPUT, "ip4-input")                                                  \
+  _ (IP6_INPUT, "ip6-input")                                                  \
+  _ (MPLS_INPUT, "mpls-input")
 
 typedef enum
 {
@@ -175,6 +176,17 @@ ipip_input (vlib_main_t * vm, vlib_node_runtime_t * node,
 	      else
 		tunnel_decap_fixup_4o4 (t0->flags, ip40 + 1, ip40);
 	    }
+	  else if (inner_protocol0 == IP_PROTOCOL_MPLS_IN_IP)
+	    {
+	      next0 = IPIP_INPUT_NEXT_MPLS_INPUT;
+
+	      if (is_ipv6)
+		tunnel_decap_fixup_mplso6 (
+		  t0->flags, (mpls_unicast_header_t *) (ip60 + 1), ip60);
+	      else
+		tunnel_decap_fixup_mplso4 (
+		  t0->flags, (mpls_unicast_header_t *) ip40 + 1, ip40);
+	    }
 
 	  if (!is_ipv6 && t0->mode == IPIP_MODE_6RD
 	      && t0->sixrd.security_check)
diff --git a/src/vnet/tunnel/tunnel_dp.h b/src/vnet/tunnel/tunnel_dp.h
index f84e764f7ea..d6f07b5ec21 100644
--- a/src/vnet/tunnel/tunnel_dp.h
+++ b/src/vnet/tunnel/tunnel_dp.h
@@ -121,6 +121,25 @@ tunnel_encap_fixup_4o6 (tunnel_encap_decap_flags_t flags,
 }
 
 static_always_inline void
+tunnel_encap_fixup_mplso6 (tunnel_encap_decap_flags_t flags,
+			   const mpls_unicast_header_t *inner,
+			   ip6_header_t *outer)
+{
+  if (flags & TUNNEL_ENCAP_DECAP_FLAG_ENCAP_COPY_DSCP)
+    ip6_set_dscp_network_order (outer,
+				vnet_mpls_uc_get_exp (inner->label_exp_s_ttl));
+}
+
+static_always_inline void
+tunnel_encap_fixup_mplso4 (tunnel_encap_decap_flags_t flags,
+			   const mpls_unicast_header_t *inner,
+			   ip4_header_t *outer)
+{
+  if (flags & TUNNEL_ENCAP_DECAP_FLAG_ENCAP_COPY_DSCP)
+    ip4_header_set_dscp (outer, vnet_mpls_uc_get_exp (inner->label_exp_s_ttl));
+}
+
+static_always_inline void
 tunnel_decap_fixup_4o6 (tunnel_encap_decap_flags_t flags,
 			ip4_header_t * inner, const ip6_header_t * outer)
 {
@@ -152,6 +171,20 @@ tunnel_decap_fixup_4o4 (tunnel_encap_decap_flags_t flags,
     ip4_header_set_ecn_w_chksum (inner, ip4_header_get_ecn (outer));
 }
 
+static_always_inline void
+tunnel_decap_fixup_mplso6 (tunnel_encap_decap_flags_t flags,
+			   mpls_unicast_header_t *inner,
+			   const ip6_header_t *outer)
+{
+}
+
+static_always_inline void
+tunnel_decap_fixup_mplso4 (tunnel_encap_decap_flags_t flags,
+			   mpls_unicast_header_t *inner,
+			   const ip4_header_t *outer)
+{
+}
+
 #endif
 
 /*