ipsec: support UDP encap/decap for NAT traversal
[vpp.git] / src / vnet / ipsec / esp_encrypt.c
index 44a0451..0ce5e54 100644 (file)
@@ -18,6 +18,7 @@
 #include <vnet/vnet.h>
 #include <vnet/api_errno.h>
 #include <vnet/ip/ip.h>
+#include <vnet/udp/udp.h>
 
 #include <vnet/ipsec/ipsec.h>
 #include <vnet/ipsec/esp.h>
@@ -65,6 +66,7 @@ typedef struct
 {
   u32 spi;
   u32 seq;
+  u8 udp_encap;
   ipsec_crypto_alg_t crypto_alg;
   ipsec_integ_alg_t integ_alg;
 } esp_encrypt_trace_t;
@@ -77,10 +79,11 @@ format_esp_encrypt_trace (u8 * s, va_list * args)
   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
   esp_encrypt_trace_t *t = va_arg (*args, esp_encrypt_trace_t *);
 
-  s = format (s, "esp: spi %u seq %u crypto %U integrity %U",
+  s = format (s, "esp: spi %u seq %u crypto %U integrity %U%s",
              t->spi, t->seq,
              format_ipsec_crypto_alg, t->crypto_alg,
-             format_ipsec_integ_alg, t->integ_alg);
+             format_ipsec_integ_alg, t->integ_alg,
+             t->udp_encap ? " udp-encap-enabled" : "");
   return s;
 }
 
@@ -155,13 +158,14 @@ esp_encrypt_node_fn (vlib_main_t * vm,
          vlib_buffer_t *i_b0, *o_b0 = 0;
          u32 sa_index0;
          ipsec_sa_t *sa0;
-         ip4_and_esp_header_t *ih0, *oh0 = 0;
+         ip4_and_esp_header_t *oh0 = 0;
          ip6_and_esp_header_t *ih6_0, *oh6_0 = 0;
+         ip4_and_udp_and_esp_header_t *iuh0, *ouh0 = 0;
          uword last_empty_buffer;
          esp_header_t *o_esp0;
          esp_footer_t *f0;
          u8 is_ipv6;
-         u8 ip_hdr_size;
+         u8 ip_udp_hdr_size;
          u8 next_hdr_type;
          u32 ip_proto = 0;
          u8 transport_mode = 0;
@@ -198,7 +202,7 @@ esp_encrypt_node_fn (vlib_main_t * vm,
          o_b0 = vlib_get_buffer (vm, o_bi0);
          o_b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
          o_b0->current_data = sizeof (ethernet_header_t);
-         ih0 = vlib_buffer_get_current (i_b0);
+         iuh0 = vlib_buffer_get_current (i_b0);
          vlib_prefetch_buffer_with_index (vm,
                                           empty_buffers[last_empty_buffer -
                                                         1], STORE);
@@ -211,18 +215,18 @@ esp_encrypt_node_fn (vlib_main_t * vm,
 
          /* is ipv6 */
          if (PREDICT_FALSE
-             ((ih0->ip4.ip_version_and_header_length & 0xF0) == 0x60))
+             ((iuh0->ip4.ip_version_and_header_length & 0xF0) == 0x60))
            {
              is_ipv6 = 1;
              ih6_0 = vlib_buffer_get_current (i_b0);
-             ip_hdr_size = sizeof (ip6_header_t);
              next_hdr_type = IP_PROTOCOL_IPV6;
              oh6_0 = vlib_buffer_get_current (o_b0);
-             o_esp0 = vlib_buffer_get_current (o_b0) + sizeof (ip6_header_t);
 
              oh6_0->ip6.ip_version_traffic_class_and_flow_label =
                ih6_0->ip6.ip_version_traffic_class_and_flow_label;
              oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_ESP;
+             ip_udp_hdr_size = sizeof (ip6_header_t);
+             o_esp0 = vlib_buffer_get_current (o_b0) + ip_udp_hdr_size;
              oh6_0->ip6.hop_limit = 254;
              oh6_0->ip6.src_address.as_u64[0] =
                ih6_0->ip6.src_address.as_u64[0];
@@ -232,8 +236,8 @@ esp_encrypt_node_fn (vlib_main_t * vm,
                ih6_0->ip6.dst_address.as_u64[0];
              oh6_0->ip6.dst_address.as_u64[1] =
                ih6_0->ip6.dst_address.as_u64[1];
-             oh6_0->esp.spi = clib_net_to_host_u32 (sa0->spi);
-             oh6_0->esp.seq = clib_net_to_host_u32 (sa0->seq);
+             o_esp0->spi = clib_net_to_host_u32 (sa0->spi);
+             o_esp0->seq = clib_net_to_host_u32 (sa0->seq);
              ip_proto = ih6_0->ip6.protocol;
 
              next0 = ESP_ENCRYPT_NEXT_IP6_LOOKUP;
@@ -241,22 +245,37 @@ esp_encrypt_node_fn (vlib_main_t * vm,
          else
            {
              is_ipv6 = 0;
-             ip_hdr_size = sizeof (ip4_header_t);
              next_hdr_type = IP_PROTOCOL_IP_IN_IP;
              oh0 = vlib_buffer_get_current (o_b0);
-             o_esp0 = vlib_buffer_get_current (o_b0) + sizeof (ip4_header_t);
+             ouh0 = vlib_buffer_get_current (o_b0);
 
              oh0->ip4.ip_version_and_header_length = 0x45;
-             oh0->ip4.tos = ih0->ip4.tos;
+             oh0->ip4.tos = iuh0->ip4.tos;
              oh0->ip4.fragment_id = 0;
              oh0->ip4.flags_and_fragment_offset = 0;
              oh0->ip4.ttl = 254;
-             oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
-             oh0->ip4.src_address.as_u32 = ih0->ip4.src_address.as_u32;
-             oh0->ip4.dst_address.as_u32 = ih0->ip4.dst_address.as_u32;
-             oh0->esp.spi = clib_net_to_host_u32 (sa0->spi);
-             oh0->esp.seq = clib_net_to_host_u32 (sa0->seq);
-             ip_proto = ih0->ip4.protocol;
+             if (sa0->udp_encap)
+               {
+                 ouh0->udp.src_port =
+                   clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
+                 ouh0->udp.dst_port =
+                   clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
+                 ouh0->udp.checksum = 0;
+                 ouh0->ip4.protocol = IP_PROTOCOL_UDP;
+                 ip_udp_hdr_size =
+                   sizeof (udp_header_t) + sizeof (ip4_header_t);
+               }
+             else
+               {
+                 oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
+                 ip_udp_hdr_size = sizeof (ip4_header_t);
+               }
+             o_esp0 = vlib_buffer_get_current (o_b0) + ip_udp_hdr_size;
+             oh0->ip4.src_address.as_u32 = iuh0->ip4.src_address.as_u32;
+             oh0->ip4.dst_address.as_u32 = iuh0->ip4.dst_address.as_u32;
+             o_esp0->spi = clib_net_to_host_u32 (sa0->spi);
+             o_esp0->seq = clib_net_to_host_u32 (sa0->seq);
+             ip_proto = iuh0->ip4.protocol;
 
              next0 = ESP_ENCRYPT_NEXT_IP4_LOOKUP;
            }
@@ -299,7 +318,7 @@ esp_encrypt_node_fn (vlib_main_t * vm,
                  vnet_buffer (o_b0)->sw_if_index[VLIB_TX] =
                    vnet_buffer (i_b0)->sw_if_index[VLIB_TX];
                }
-             vlib_buffer_advance (i_b0, ip_hdr_size);
+             vlib_buffer_advance (i_b0, ip_udp_hdr_size);
            }
 
          ASSERT (sa0->crypto_alg < IPSEC_CRYPTO_N_ALG);
@@ -327,7 +346,7 @@ esp_encrypt_node_fn (vlib_main_t * vm,
              f0->pad_length = pad_bytes;
              f0->next_header = next_hdr_type;
 
-             o_b0->current_length = ip_hdr_size + sizeof (esp_header_t) +
+             o_b0->current_length = ip_udp_hdr_size + sizeof (esp_header_t) +
                BLOCK_SIZE * blocks + IV_SIZE;
 
              vnet_buffer (o_b0)->sw_if_index[VLIB_RX] =
@@ -338,14 +357,14 @@ esp_encrypt_node_fn (vlib_main_t * vm,
              RAND_bytes (iv, sizeof (iv));
 
              clib_memcpy ((u8 *) vlib_buffer_get_current (o_b0) +
-                          ip_hdr_size + sizeof (esp_header_t), iv,
+                          ip_udp_hdr_size + sizeof (esp_header_t), iv,
                           em->ipsec_proto_main_crypto_algs[sa0->
                                                            crypto_alg].iv_size);
 
              esp_encrypt_cbc (sa0->crypto_alg,
                               (u8 *) vlib_buffer_get_current (i_b0),
                               (u8 *) vlib_buffer_get_current (o_b0) +
-                              ip_hdr_size + sizeof (esp_header_t) +
+                              ip_udp_hdr_size + sizeof (esp_header_t) +
                               IV_SIZE, BLOCK_SIZE * blocks,
                               sa0->crypto_key, iv);
            }
@@ -354,7 +373,7 @@ esp_encrypt_node_fn (vlib_main_t * vm,
                                             sa0->integ_key_len,
                                             (u8 *) o_esp0,
                                             o_b0->current_length -
-                                            ip_hdr_size,
+                                            ip_udp_hdr_size,
                                             vlib_buffer_get_current (o_b0) +
                                             o_b0->current_length,
                                             sa0->use_esn, sa0->seq_hi);
@@ -371,6 +390,12 @@ esp_encrypt_node_fn (vlib_main_t * vm,
              oh0->ip4.length =
                clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0));
              oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
+             if (sa0->udp_encap)
+               {
+                 ouh0->udp.length =
+                   clib_host_to_net_u16 (oh0->ip4.length -
+                                         ip4_header_bytes (&oh0->ip4));
+               }
            }
 
          if (transport_mode)
@@ -387,6 +412,7 @@ esp_encrypt_node_fn (vlib_main_t * vm,
                    vlib_add_trace (vm, node, o_b0, sizeof (*tr));
                  tr->spi = sa0->spi;
                  tr->seq = sa0->seq - 1;
+                 tr->udp_encap = sa0->udp_encap;
                  tr->crypto_alg = sa0->crypto_alg;
                  tr->integ_alg = sa0->integ_alg;
                }