src/vnet/ipsec/esp_encrypt.c - fdio/vpp - Gitiles

 /*
  * esp_encrypt.c : IPSec ESP encrypt node
  *
  * Copyright (c) 2015 Cisco and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <vnet/vnet.h>
 #include <vnet/api_errno.h>
 #include <vnet/ip/ip.h>
 #include <vnet/udp/udp.h>

 #include <vnet/crypto/crypto.h>

 #include <vnet/ipsec/ipsec.h>
 #include <vnet/ipsec/esp.h>

 #define foreach_esp_encrypt_next                   \
 _(DROP, "error-drop")                              \
 _(IP4_LOOKUP, "ip4-lookup")                        \
 _(IP6_LOOKUP, "ip6-lookup")                        \
 _(INTERFACE_OUTPUT, "interface-output")

 #define _(v, s) ESP_ENCRYPT_NEXT_##v,
 typedef enum
 {
   foreach_esp_encrypt_next
 #undef _
     ESP_ENCRYPT_N_NEXT,
 } esp_encrypt_next_t;

 #define foreach_esp_encrypt_error                               \
  _(RX_PKTS, "ESP pkts received")                                \
  _(SEQ_CYCLED, "sequence number cycled (packet dropped)")       \
  _(CRYPTO_ENGINE_ERROR, "crypto engine error (packet dropped)") \
  _(CHAINED_BUFFER, "chained buffers (packet dropped)")          \
  _(NO_TRAILER_SPACE, "no trailer space (packet dropped)")

 typedef enum
 {
 #define _(sym,str) ESP_ENCRYPT_ERROR_##sym,
   foreach_esp_encrypt_error
 #undef _
     ESP_ENCRYPT_N_ERROR,
 } esp_encrypt_error_t;

 static char *esp_encrypt_error_strings[] = {
 #define _(sym,string) string,
   foreach_esp_encrypt_error
 #undef _
 };

 typedef struct
 {
   u32 sa_index;
   u32 spi;
   u32 seq;
   u8 udp_encap;
   ipsec_crypto_alg_t crypto_alg;
   ipsec_integ_alg_t integ_alg;
 } esp_encrypt_trace_t;

 /* packet trace format function */
 static u8 *
 format_esp_encrypt_trace (u8 * s, va_list * args)
 {
   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
   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: sa-index %d spi %u seq %u crypto %U integrity %U%s",
 	      t->sa_index, t->spi, t->seq,
 	      format_ipsec_crypto_alg, t->crypto_alg,
 	      format_ipsec_integ_alg, t->integ_alg,
 	      t->udp_encap ? " udp-encap-enabled" : "");
   return s;
 }

 /* pad packet in input buffer */
 static_always_inline u8 *
 esp_add_footer_and_icv (vlib_buffer_t * b, u8 block_size, u8 icv_sz)
 {
   static const u8 pad_data[ESP_MAX_BLOCK_SIZE] = {
     0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
     0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x00, 0x00,
   };

   u16 min_length = b->current_length + sizeof (esp_footer_t);
   u16 new_length = round_pow2 (min_length, block_size);
   u8 pad_bytes = new_length - min_length;
   esp_footer_t *f = (esp_footer_t *) (vlib_buffer_get_current (b) +
 				      new_length - sizeof (esp_footer_t));

   if (pad_bytes)
     clib_memcpy_fast ((u8 *) f - pad_bytes, pad_data, ESP_MAX_BLOCK_SIZE);

   f->pad_length = pad_bytes;
   b->current_length = new_length + icv_sz;
   return &f->next_header;
 }

 static_always_inline void
 esp_update_ip4_hdr (ip4_header_t * ip4, u16 len, int is_transport, int is_udp)
 {
   ip_csum_t sum;
   u16 old_len;

   len = clib_net_to_host_u16 (len);
   old_len = ip4->length;

   if (is_transport)
     {
       u8 prot = is_udp ? IP_PROTOCOL_UDP : IP_PROTOCOL_IPSEC_ESP;

       sum = ip_csum_update (ip4->checksum, ip4->protocol,
 			    prot, ip4_header_t, protocol);
       ip4->protocol = prot;

       sum = ip_csum_update (sum, old_len, len, ip4_header_t, length);
     }
   else
     sum = ip_csum_update (ip4->checksum, old_len, len, ip4_header_t, length);

   ip4->length = len;
   ip4->checksum = ip_csum_fold (sum);
 }

 static_always_inline void
 esp_fill_udp_hdr (ipsec_sa_t * sa, udp_header_t * udp, u16 len)
 {
   clib_memcpy_fast (udp, &sa->udp_hdr, sizeof (udp_header_t));
   udp->length = clib_net_to_host_u16 (len);
 }

 static_always_inline u8
 ext_hdr_is_pre_esp (u8 nexthdr)
 {
 #ifdef CLIB_HAVE_VEC128
   static const u8x16 ext_hdr_types = {
     IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS,
     IP_PROTOCOL_IPV6_ROUTE,
     IP_PROTOCOL_IPV6_FRAGMENTATION,
   };

   return !u8x16_is_all_zero (ext_hdr_types == u8x16_splat (nexthdr));
 #else
   return ((nexthdr ^ IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS) |
 	  (nexthdr ^ IP_PROTOCOL_IPV6_ROUTE) |
 	  (nexthdr ^ IP_PROTOCOL_IPV6_FRAGMENTATION) != 0);
 #endif
 }

 static_always_inline u8
 esp_get_ip6_hdr_len (ip6_header_t * ip6)
 {
   /* this code assumes that HbH, route and frag headers will be before
      others, if that is not the case, they will end up encrypted */

   u8 len = sizeof (ip6_header_t);
   ip6_ext_header_t *p;

   /* if next packet doesn't have ext header */
   if (ext_hdr_is_pre_esp (ip6->protocol) == 0)
     return len;

   p = (void *) (ip6 + 1);
   len += ip6_ext_header_len (p);

   while (ext_hdr_is_pre_esp (p->next_hdr))
     {
       len += ip6_ext_header_len (p);
       p = ip6_ext_next_header (p);
     }

   return len;
 }

 static_always_inline int
 esp_trailer_icv_overflow (vlib_node_runtime_t * node, vlib_buffer_t * b,
 			  u16 * next, u16 buffer_data_size)
 {
   if (b->current_data + b->current_length <= buffer_data_size)
     return 0;

   b->current_length -= buffer_data_size - b->current_data;
   b->error = node->errors[ESP_ENCRYPT_ERROR_NO_TRAILER_SPACE];
   next[0] = ESP_ENCRYPT_NEXT_DROP;
   return 1;
 }

 static_always_inline void
 esp_process_ops (vlib_main_t * vm, vlib_node_runtime_t * node,
 		 vnet_crypto_op_t * ops, vlib_buffer_t * b[], u16 * nexts)
 {
   u32 n_fail, n_ops = vec_len (ops);
   vnet_crypto_op_t *op = ops;

   if (n_ops == 0)
     return;

   n_fail = n_ops - vnet_crypto_process_ops (vm, op, n_ops);

   while (n_fail)
     {
       ASSERT (op - ops < n_ops);

       if (op->status != VNET_CRYPTO_OP_STATUS_COMPLETED)
 	{
 	  u32 bi = op->user_data;
 	  b[bi]->error = node->errors[ESP_ENCRYPT_ERROR_CRYPTO_ENGINE_ERROR];
 	  nexts[bi] = ESP_ENCRYPT_NEXT_DROP;
 	  n_fail--;
 	}
       op++;
     }
 }

 always_inline uword
 esp_encrypt_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 		    vlib_frame_t * frame, int is_ip6, int is_tun)
 {
   ipsec_main_t *im = &ipsec_main;
   ipsec_per_thread_data_t *ptd = vec_elt_at_index (im->ptd, vm->thread_index);
   u32 *from = vlib_frame_vector_args (frame);
   u32 n_left = frame->n_vectors;
   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
   u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
   u32 thread_index = vm->thread_index;
   u16 buffer_data_size = vlib_buffer_get_default_data_size (vm);
   u32 current_sa_index = ~0, current_sa_packets = 0;
   u32 current_sa_bytes = 0, spi = 0;
   u8 block_sz = 0, iv_sz = 0, icv_sz = 0;
   ipsec_sa_t *sa0 = 0;

   vlib_get_buffers (vm, from, b, n_left);
   vec_reset_length (ptd->crypto_ops);
   vec_reset_length (ptd->integ_ops);

   while (n_left > 0)
     {
       u32 sa_index0 = vnet_buffer (b[0])->ipsec.sad_index;
       dpo_id_t *dpo;
       esp_header_t *esp;
       u8 *payload, *next_hdr_ptr;
       u16 payload_len;
       u32 hdr_len;

       if (n_left > 2)
 	{
 	  u8 *p;
 	  vlib_prefetch_buffer_header (b[2], LOAD);
 	  p = vlib_buffer_get_current (b[1]);
 	  CLIB_PREFETCH (p, CLIB_CACHE_LINE_BYTES, LOAD);
 	  p -= CLIB_CACHE_LINE_BYTES;
 	  CLIB_PREFETCH (p, CLIB_CACHE_LINE_BYTES, LOAD);
 	}

       if (is_tun)
 	{
 	  /* we are on a ipsec tunnel's feature arc */
 	  u32 next0;
 	  sa_index0 = *(u32 *) vnet_feature_next_with_data (&next0, b[0],
 							    sizeof
 							    (sa_index0));
 	  next[0] = next0;
 	}
       else
 	sa_index0 = vnet_buffer (b[0])->ipsec.sad_index;

       if (sa_index0 != current_sa_index)
 	{
 	  sa0 = pool_elt_at_index (im->sad, sa_index0);
 	  current_sa_index = sa_index0;
 	  vlib_increment_combined_counter (&ipsec_sa_counters, thread_index,
 					   sa_index0, current_sa_packets,
 					   current_sa_bytes);
 	  current_sa_packets = current_sa_bytes = 0;
 	  spi = clib_net_to_host_u32 (sa0->spi);
 	  block_sz = sa0->crypto_block_size;
 	  icv_sz = sa0->integ_icv_size;
 	  iv_sz = sa0->crypto_iv_size;
 	}

       if (vlib_buffer_chain_linearize (vm, b[0]) != 1)
 	{
 	  b[0]->error = node->errors[ESP_ENCRYPT_ERROR_CHAINED_BUFFER];
 	  next[0] = ESP_ENCRYPT_NEXT_DROP;
 	  goto trace;
 	}

       if (PREDICT_FALSE (esp_seq_advance (sa0)))
 	{
 	  b[0]->error = node->errors[ESP_ENCRYPT_ERROR_SEQ_CYCLED];
 	  next[0] = ESP_ENCRYPT_NEXT_DROP;
 	  goto trace;
 	}

       /* space for IV */
       hdr_len = iv_sz;

       if (ipsec_sa_is_set_IS_TUNNEL (sa0))
 	{
 	  payload = vlib_buffer_get_current (b[0]);
 	  next_hdr_ptr = esp_add_footer_and_icv (b[0], block_sz, icv_sz);
 	  payload_len = b[0]->current_length;

 	  if (esp_trailer_icv_overflow (node, b[0], next, buffer_data_size))
 	    goto trace;

 	  /* ESP header */
 	  hdr_len += sizeof (*esp);
 	  esp = (esp_header_t *) (payload - hdr_len);

 	  /* optional UDP header */
 	  if (ipsec_sa_is_set_UDP_ENCAP (sa0))
 	    {
 	      hdr_len += sizeof (udp_header_t);
 	      esp_fill_udp_hdr (sa0, (udp_header_t *) (payload - hdr_len),
 				payload_len + hdr_len);
 	    }

 	  /* IP header */
 	  if (ipsec_sa_is_set_IS_TUNNEL_V6 (sa0))
 	    {
 	      ip6_header_t *ip6;
 	      u16 len = sizeof (ip6_header_t);
 	      hdr_len += len;
 	      ip6 = (ip6_header_t *) (payload - hdr_len);
 	      clib_memcpy_fast (ip6, &sa0->ip6_hdr, len);
 	      *next_hdr_ptr = (is_ip6 ?
 			       IP_PROTOCOL_IPV6 : IP_PROTOCOL_IP_IN_IP);
 	      len = payload_len + hdr_len - len;
 	      ip6->payload_length = clib_net_to_host_u16 (len);
 	    }
 	  else
 	    {
 	      ip4_header_t *ip4;
 	      u16 len = sizeof (ip4_header_t);
 	      hdr_len += len;
 	      ip4 = (ip4_header_t *) (payload - hdr_len);
 	      clib_memcpy_fast (ip4, &sa0->ip4_hdr, len);
 	      *next_hdr_ptr = (is_ip6 ?
 			       IP_PROTOCOL_IPV6 : IP_PROTOCOL_IP_IN_IP);
 	      len = payload_len + hdr_len;
 	      esp_update_ip4_hdr (ip4, len, /* is_transport */ 0, 0);
 	    }

 	  dpo = sa0->dpo + IPSEC_PROTOCOL_ESP;
 	  if (!is_tun)
 	    {
 	      next[0] = dpo->dpoi_next_node;
 	      vnet_buffer (b[0])->ip.adj_index[VLIB_TX] = dpo->dpoi_index;
 	    }
 	}
       else			/* transport mode */
 	{
 	  u8 *l2_hdr, l2_len, *ip_hdr, ip_len;
 	  udp_header_t *udp = 0;
 	  u8 *old_ip_hdr = vlib_buffer_get_current (b[0]);

 	  ip_len = is_ip6 ?
 	    esp_get_ip6_hdr_len ((ip6_header_t *) old_ip_hdr) :
 	    ip4_header_bytes ((ip4_header_t *) old_ip_hdr);

 	  vlib_buffer_advance (b[0], ip_len);
 	  payload = vlib_buffer_get_current (b[0]);
 	  next_hdr_ptr = esp_add_footer_and_icv (b[0], block_sz, icv_sz);
 	  payload_len = b[0]->current_length;

 	  if (esp_trailer_icv_overflow (node, b[0], next, buffer_data_size))
 	    goto trace;

 	  /* ESP header */
 	  hdr_len += sizeof (*esp);
 	  esp = (esp_header_t *) (payload - hdr_len);

 	  /* optional UDP header */
 	  if (ipsec_sa_is_set_UDP_ENCAP (sa0))
 	    {
 	      hdr_len += sizeof (udp_header_t);
 	      udp = (udp_header_t *) (payload - hdr_len);
 	    }

 	  /* IP header */
 	  hdr_len += ip_len;
 	  ip_hdr = payload - hdr_len;

 	  /* L2 header */
 	  l2_len = vnet_buffer (b[0])->ip.save_rewrite_length;
 	  hdr_len += l2_len;
 	  l2_hdr = payload - hdr_len;

 	  /* copy l2 and ip header */
 	  clib_memcpy_le32 (l2_hdr, old_ip_hdr - l2_len, l2_len);
 	  clib_memcpy_le64 (ip_hdr, old_ip_hdr, ip_len);

 	  if (is_ip6)
 	    {
 	      ip6_header_t *ip6 = (ip6_header_t *) (ip_hdr);
 	      *next_hdr_ptr = ip6->protocol;
 	      ip6->protocol = IP_PROTOCOL_IPSEC_ESP;
 	      ip6->payload_length =
 		clib_host_to_net_u16 (payload_len + hdr_len - l2_len -
 				      ip_len);
 	    }
 	  else
 	    {
 	      u16 len;
 	      ip4_header_t *ip4 = (ip4_header_t *) (ip_hdr);
 	      *next_hdr_ptr = ip4->protocol;
 	      len = payload_len + hdr_len - l2_len;
 	      if (udp)
 		{
 		  esp_update_ip4_hdr (ip4, len, /* is_transport */ 1, 1);
 		  esp_fill_udp_hdr (sa0, udp, len - ip_len);
 		}
 	      else
 		esp_update_ip4_hdr (ip4, len, /* is_transport */ 1, 0);
 	    }

 	  next[0] = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
 	}

       esp->spi = spi;
       esp->seq = clib_net_to_host_u32 (sa0->seq);

       if (sa0->crypto_enc_op_id)
 	{
 	  vnet_crypto_op_t *op;
 	  vec_add2_aligned (ptd->crypto_ops, op, 1, CLIB_CACHE_LINE_BYTES);
 	  vnet_crypto_op_init (op, sa0->crypto_enc_op_id);
 	  op->iv = payload - iv_sz;
 	  op->src = op->dst = payload;
 	  op->key = sa0->crypto_key.data;
 	  op->len = payload_len - icv_sz;
 	  op->flags = VNET_CRYPTO_OP_FLAG_INIT_IV;
 	  op->user_data = b - bufs;
 	  op->salt = sa0->salt;

 	  if (ipsec_sa_is_set_IS_AEAD (sa0))
 	    {
 	      /*
 	       * construct the AAD in a scratch space in front
 	       * of the IP header.
 	       */
 	      op->aad = payload - hdr_len - sizeof (esp_aead_t);

 	      esp_aad_fill (op, esp, sa0);

 	      op->tag = payload + op->len;
 	      op->tag_len = 16;
 	    }
 	}

       if (sa0->integ_op_id)
 	{
 	  vnet_crypto_op_t *op;
 	  vec_add2_aligned (ptd->integ_ops, op, 1, CLIB_CACHE_LINE_BYTES);
 	  vnet_crypto_op_init (op, sa0->integ_op_id);
 	  op->src = payload - iv_sz - sizeof (esp_header_t);
 	  op->digest = payload + payload_len - icv_sz;
 	  op->key = sa0->integ_key.data;
 	  op->key_len = sa0->integ_key.len;
 	  op->digest_len = icv_sz;
 	  op->len = payload_len - icv_sz + iv_sz + sizeof (esp_header_t);
 	  op->user_data = b - bufs;
 	  if (ipsec_sa_is_set_USE_ESN (sa0))
 	    {
 	      u32 seq_hi = clib_net_to_host_u32 (sa0->seq_hi);
 	      clib_memcpy_fast (op->digest, &seq_hi, sizeof (seq_hi));
 	      op->len += sizeof (seq_hi);
 	    }
 	}

       vlib_buffer_advance (b[0], 0LL - hdr_len);

       current_sa_packets += 1;
       current_sa_bytes += payload_len;

     trace:
       if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
 	{
 	  esp_encrypt_trace_t *tr = vlib_add_trace (vm, node, b[0],
 						    sizeof (*tr));
 	  tr->sa_index = sa_index0;
 	  tr->spi = sa0->spi;
 	  tr->seq = sa0->seq - 1;
 	  tr->udp_encap = ipsec_sa_is_set_UDP_ENCAP (sa0);
 	  tr->crypto_alg = sa0->crypto_alg;
 	  tr->integ_alg = sa0->integ_alg;
 	}
       /* next */
       n_left -= 1;
       next += 1;
       b += 1;
     }

   vlib_increment_combined_counter (&ipsec_sa_counters, thread_index,
 				   current_sa_index, current_sa_packets,
 				   current_sa_bytes);
   esp_process_ops (vm, node, ptd->crypto_ops, bufs, nexts);
   esp_process_ops (vm, node, ptd->integ_ops, bufs, nexts);

   vlib_node_increment_counter (vm, node->node_index,
 			       ESP_ENCRYPT_ERROR_RX_PKTS, frame->n_vectors);

   vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
   return frame->n_vectors;
 }

 VLIB_NODE_FN (esp4_encrypt_node) (vlib_main_t * vm,
 				  vlib_node_runtime_t * node,
 				  vlib_frame_t * from_frame)
 {
   return esp_encrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ , 0);
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (esp4_encrypt_node) = {
   .name = "esp4-encrypt",
   .vector_size = sizeof (u32),
   .format_trace = format_esp_encrypt_trace,
   .type = VLIB_NODE_TYPE_INTERNAL,

   .n_errors = ARRAY_LEN(esp_encrypt_error_strings),
   .error_strings = esp_encrypt_error_strings,

   .n_next_nodes = ESP_ENCRYPT_N_NEXT,
   .next_nodes = {
 #define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
     foreach_esp_encrypt_next
 #undef _
   },
 };
 /* *INDENT-ON* */

 VLIB_NODE_FN (esp6_encrypt_node) (vlib_main_t * vm,
 				  vlib_node_runtime_t * node,
 				  vlib_frame_t * from_frame)
 {
   return esp_encrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ , 0);
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (esp6_encrypt_node) = {
   .name = "esp6-encrypt",
   .vector_size = sizeof (u32),
   .format_trace = format_esp_encrypt_trace,
   .type = VLIB_NODE_TYPE_INTERNAL,

   .n_errors = ARRAY_LEN(esp_encrypt_error_strings),
   .error_strings = esp_encrypt_error_strings,

   .n_next_nodes = ESP_ENCRYPT_N_NEXT,
   .next_nodes = {
 #define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
     foreach_esp_encrypt_next
 #undef _
   },
 };
 /* *INDENT-ON* */

 VLIB_NODE_FN (esp4_encrypt_tun_node) (vlib_main_t * vm,
 				      vlib_node_runtime_t * node,
 				      vlib_frame_t * from_frame)
 {
   return esp_encrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ , 1);
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (esp4_encrypt_tun_node) = {
   .name = "esp4-encrypt-tun",
   .vector_size = sizeof (u32),
   .format_trace = format_esp_encrypt_trace,
   .type = VLIB_NODE_TYPE_INTERNAL,

   .n_errors = ARRAY_LEN(esp_encrypt_error_strings),
   .error_strings = esp_encrypt_error_strings,

   .n_next_nodes = 1,
   .next_nodes = {
     [ESP_ENCRYPT_NEXT_DROP] = "ip4-drop",
   },
 };

 VNET_FEATURE_INIT (esp4_encrypt_tun_feat_node, static) =
 {
   .arc_name = "ip4-output",
   .node_name = "esp4-encrypt-tun",
   .runs_before = VNET_FEATURES ("adj-midchain-tx"),
 };
 /* *INDENT-ON* */

 VLIB_NODE_FN (esp6_encrypt_tun_node) (vlib_main_t * vm,
 				      vlib_node_runtime_t * node,
 				      vlib_frame_t * from_frame)
 {
   return esp_encrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ , 1);
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (esp6_encrypt_tun_node) = {
   .name = "esp6-encrypt-tun",
   .vector_size = sizeof (u32),
   .format_trace = format_esp_encrypt_trace,
   .type = VLIB_NODE_TYPE_INTERNAL,

   .n_errors = ARRAY_LEN(esp_encrypt_error_strings),
   .error_strings = esp_encrypt_error_strings,

   .n_next_nodes = 1,
   .next_nodes = {
     [ESP_ENCRYPT_NEXT_DROP] = "ip6-drop",
   },
 };

 VNET_FEATURE_INIT (esp6_encrypt_tun_feat_node, static) =
 {
   .arc_name = "ip6-output",
   .node_name = "esp6-encrypt-tun",
   .runs_before = VNET_FEATURES ("adj-midchain-tx"),
 };
 /* *INDENT-ON* */

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* esp_encrypt.c : IPSec ESP encrypt node
	*
	* Copyright (c) 2015 Cisco and/or its affiliates.
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at:
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <vnet/vnet.h>
	#include <vnet/api_errno.h>
	#include <vnet/ip/ip.h>
	#include <vnet/udp/udp.h>

	#include <vnet/crypto/crypto.h>

	#include <vnet/ipsec/ipsec.h>
	#include <vnet/ipsec/esp.h>

	#define foreach_esp_encrypt_next \
	_(DROP, "error-drop") \
	_(IP4_LOOKUP, "ip4-lookup") \
	_(IP6_LOOKUP, "ip6-lookup") \
	_(INTERFACE_OUTPUT, "interface-output")

	#define _(v, s) ESP_ENCRYPT_NEXT_##v,
	typedef enum
	{
	foreach_esp_encrypt_next
	#undef _
	ESP_ENCRYPT_N_NEXT,
	} esp_encrypt_next_t;

	#define foreach_esp_encrypt_error \
	_(RX_PKTS, "ESP pkts received") \
	_(SEQ_CYCLED, "sequence number cycled (packet dropped)") \
	_(CRYPTO_ENGINE_ERROR, "crypto engine error (packet dropped)") \
	_(CHAINED_BUFFER, "chained buffers (packet dropped)") \
	_(NO_TRAILER_SPACE, "no trailer space (packet dropped)")

	typedef enum
	{
	#define _(sym,str) ESP_ENCRYPT_ERROR_##sym,
	foreach_esp_encrypt_error
	#undef _
	ESP_ENCRYPT_N_ERROR,
	} esp_encrypt_error_t;

	static char *esp_encrypt_error_strings[] = {
	#define _(sym,string) string,
	foreach_esp_encrypt_error
	#undef _
	};

	typedef struct
	{
	u32 sa_index;
	u32 spi;
	u32 seq;
	u8 udp_encap;
	ipsec_crypto_alg_t crypto_alg;
	ipsec_integ_alg_t integ_alg;
	} esp_encrypt_trace_t;

	/* packet trace format function */
	static u8 *
	format_esp_encrypt_trace (u8 * s, va_list * args)
	{
	CLIB_UNUSED (vlib_main_t * vm) = va_arg (args, vlib_main_t );
	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: sa-index %d spi %u seq %u crypto %U integrity %U%s",
	t->sa_index, t->spi, t->seq,
	format_ipsec_crypto_alg, t->crypto_alg,
	format_ipsec_integ_alg, t->integ_alg,
	t->udp_encap ? " udp-encap-enabled" : "");
	return s;
	}

	/* pad packet in input buffer */
	static_always_inline u8 *
	esp_add_footer_and_icv (vlib_buffer_t * b, u8 block_size, u8 icv_sz)
	{
	static const u8 pad_data[ESP_MAX_BLOCK_SIZE] = {
	0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
	0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x00, 0x00,
	};

	u16 min_length = b->current_length + sizeof (esp_footer_t);
	u16 new_length = round_pow2 (min_length, block_size);
	u8 pad_bytes = new_length - min_length;
	esp_footer_t f = (esp_footer_t ) (vlib_buffer_get_current (b) +
	new_length - sizeof (esp_footer_t));

	if (pad_bytes)
	clib_memcpy_fast ((u8 *) f - pad_bytes, pad_data, ESP_MAX_BLOCK_SIZE);

	f->pad_length = pad_bytes;
	b->current_length = new_length + icv_sz;
	return &f->next_header;
	}

	static_always_inline void
	esp_update_ip4_hdr (ip4_header_t * ip4, u16 len, int is_transport, int is_udp)
	{
	ip_csum_t sum;
	u16 old_len;

	len = clib_net_to_host_u16 (len);
	old_len = ip4->length;

	if (is_transport)
	{
	u8 prot = is_udp ? IP_PROTOCOL_UDP : IP_PROTOCOL_IPSEC_ESP;

	sum = ip_csum_update (ip4->checksum, ip4->protocol,
	prot, ip4_header_t, protocol);
	ip4->protocol = prot;

	sum = ip_csum_update (sum, old_len, len, ip4_header_t, length);
	}
	else
	sum = ip_csum_update (ip4->checksum, old_len, len, ip4_header_t, length);

	ip4->length = len;
	ip4->checksum = ip_csum_fold (sum);
	}

	static_always_inline void
	esp_fill_udp_hdr (ipsec_sa_t * sa, udp_header_t * udp, u16 len)
	{
	clib_memcpy_fast (udp, &sa->udp_hdr, sizeof (udp_header_t));
	udp->length = clib_net_to_host_u16 (len);
	}

	static_always_inline u8
	ext_hdr_is_pre_esp (u8 nexthdr)
	{
	#ifdef CLIB_HAVE_VEC128
	static const u8x16 ext_hdr_types = {
	IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS,
	IP_PROTOCOL_IPV6_ROUTE,
	IP_PROTOCOL_IPV6_FRAGMENTATION,
	};

	return !u8x16_is_all_zero (ext_hdr_types == u8x16_splat (nexthdr));
	#else
	return ((nexthdr ^ IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS) \|
	(nexthdr ^ IP_PROTOCOL_IPV6_ROUTE) \|
	(nexthdr ^ IP_PROTOCOL_IPV6_FRAGMENTATION) != 0);
	#endif
	}

	static_always_inline u8
	esp_get_ip6_hdr_len (ip6_header_t * ip6)
	{
	/* this code assumes that HbH, route and frag headers will be before
	others, if that is not the case, they will end up encrypted */

	u8 len = sizeof (ip6_header_t);
	ip6_ext_header_t *p;

	/* if next packet doesn't have ext header */
	if (ext_hdr_is_pre_esp (ip6->protocol) == 0)
	return len;

	p = (void *) (ip6 + 1);
	len += ip6_ext_header_len (p);

	while (ext_hdr_is_pre_esp (p->next_hdr))
	{
	len += ip6_ext_header_len (p);
	p = ip6_ext_next_header (p);
	}

	return len;
	}

	static_always_inline int
	esp_trailer_icv_overflow (vlib_node_runtime_t * node, vlib_buffer_t * b,
	u16 * next, u16 buffer_data_size)
	{
	if (b->current_data + b->current_length <= buffer_data_size)
	return 0;

	b->current_length -= buffer_data_size - b->current_data;
	b->error = node->errors[ESP_ENCRYPT_ERROR_NO_TRAILER_SPACE];
	next[0] = ESP_ENCRYPT_NEXT_DROP;
	return 1;
	}

	static_always_inline void
	esp_process_ops (vlib_main_t * vm, vlib_node_runtime_t * node,
	vnet_crypto_op_t * ops, vlib_buffer_t * b[], u16 * nexts)
	{
	u32 n_fail, n_ops = vec_len (ops);
	vnet_crypto_op_t *op = ops;

	if (n_ops == 0)
	return;

	n_fail = n_ops - vnet_crypto_process_ops (vm, op, n_ops);

	while (n_fail)
	{
	ASSERT (op - ops < n_ops);

	if (op->status != VNET_CRYPTO_OP_STATUS_COMPLETED)
	{
	u32 bi = op->user_data;
	b[bi]->error = node->errors[ESP_ENCRYPT_ERROR_CRYPTO_ENGINE_ERROR];
	nexts[bi] = ESP_ENCRYPT_NEXT_DROP;
	n_fail--;
	}
	op++;
	}
	}

	always_inline uword
	esp_encrypt_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
	vlib_frame_t * frame, int is_ip6, int is_tun)
	{
	ipsec_main_t *im = &ipsec_main;
	ipsec_per_thread_data_t *ptd = vec_elt_at_index (im->ptd, vm->thread_index);
	u32 *from = vlib_frame_vector_args (frame);
	u32 n_left = frame->n_vectors;
	vlib_buffer_t bufs[VLIB_FRAME_SIZE], *b = bufs;
	u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
	u32 thread_index = vm->thread_index;
	u16 buffer_data_size = vlib_buffer_get_default_data_size (vm);
	u32 current_sa_index = ~0, current_sa_packets = 0;
	u32 current_sa_bytes = 0, spi = 0;
	u8 block_sz = 0, iv_sz = 0, icv_sz = 0;
	ipsec_sa_t *sa0 = 0;

	vlib_get_buffers (vm, from, b, n_left);
	vec_reset_length (ptd->crypto_ops);
	vec_reset_length (ptd->integ_ops);

	while (n_left > 0)
	{
	u32 sa_index0 = vnet_buffer (b[0])->ipsec.sad_index;
	dpo_id_t *dpo;
	esp_header_t *esp;
	u8 payload, next_hdr_ptr;
	u16 payload_len;
	u32 hdr_len;

	if (n_left > 2)
	{
	u8 *p;
	vlib_prefetch_buffer_header (b[2], LOAD);
	p = vlib_buffer_get_current (b[1]);
	CLIB_PREFETCH (p, CLIB_CACHE_LINE_BYTES, LOAD);
	p -= CLIB_CACHE_LINE_BYTES;
	CLIB_PREFETCH (p, CLIB_CACHE_LINE_BYTES, LOAD);
	}

	if (is_tun)
	{
	/* we are on a ipsec tunnel's feature arc */
	u32 next0;
	sa_index0 = (u32 ) vnet_feature_next_with_data (&next0, b[0],
	sizeof
	(sa_index0));
	next[0] = next0;
	}
	else
	sa_index0 = vnet_buffer (b[0])->ipsec.sad_index;

	if (sa_index0 != current_sa_index)
	{
	sa0 = pool_elt_at_index (im->sad, sa_index0);
	current_sa_index = sa_index0;
	vlib_increment_combined_counter (&ipsec_sa_counters, thread_index,
	sa_index0, current_sa_packets,
	current_sa_bytes);
	current_sa_packets = current_sa_bytes = 0;
	spi = clib_net_to_host_u32 (sa0->spi);
	block_sz = sa0->crypto_block_size;
	icv_sz = sa0->integ_icv_size;
	iv_sz = sa0->crypto_iv_size;
	}

	if (vlib_buffer_chain_linearize (vm, b[0]) != 1)
	{
	b[0]->error = node->errors[ESP_ENCRYPT_ERROR_CHAINED_BUFFER];
	next[0] = ESP_ENCRYPT_NEXT_DROP;
	goto trace;
	}

	if (PREDICT_FALSE (esp_seq_advance (sa0)))
	{
	b[0]->error = node->errors[ESP_ENCRYPT_ERROR_SEQ_CYCLED];
	next[0] = ESP_ENCRYPT_NEXT_DROP;
	goto trace;
	}

	/* space for IV */
	hdr_len = iv_sz;

	if (ipsec_sa_is_set_IS_TUNNEL (sa0))
	{
	payload = vlib_buffer_get_current (b[0]);
	next_hdr_ptr = esp_add_footer_and_icv (b[0], block_sz, icv_sz);
	payload_len = b[0]->current_length;

	if (esp_trailer_icv_overflow (node, b[0], next, buffer_data_size))
	goto trace;

	/* ESP header */
	hdr_len += sizeof (*esp);
	esp = (esp_header_t *) (payload - hdr_len);

	/* optional UDP header */
	if (ipsec_sa_is_set_UDP_ENCAP (sa0))
	{
	hdr_len += sizeof (udp_header_t);
	esp_fill_udp_hdr (sa0, (udp_header_t *) (payload - hdr_len),
	payload_len + hdr_len);
	}

	/* IP header */
	if (ipsec_sa_is_set_IS_TUNNEL_V6 (sa0))
	{
	ip6_header_t *ip6;
	u16 len = sizeof (ip6_header_t);
	hdr_len += len;
	ip6 = (ip6_header_t *) (payload - hdr_len);
	clib_memcpy_fast (ip6, &sa0->ip6_hdr, len);
	*next_hdr_ptr = (is_ip6 ?
	IP_PROTOCOL_IPV6 : IP_PROTOCOL_IP_IN_IP);
	len = payload_len + hdr_len - len;
	ip6->payload_length = clib_net_to_host_u16 (len);
	}
	else
	{
	ip4_header_t *ip4;
	u16 len = sizeof (ip4_header_t);
	hdr_len += len;
	ip4 = (ip4_header_t *) (payload - hdr_len);
	clib_memcpy_fast (ip4, &sa0->ip4_hdr, len);
	*next_hdr_ptr = (is_ip6 ?
	IP_PROTOCOL_IPV6 : IP_PROTOCOL_IP_IN_IP);
	len = payload_len + hdr_len;
	esp_update_ip4_hdr (ip4, len, /* is_transport */ 0, 0);
	}

	dpo = sa0->dpo + IPSEC_PROTOCOL_ESP;
	if (!is_tun)
	{
	next[0] = dpo->dpoi_next_node;
	vnet_buffer (b[0])->ip.adj_index[VLIB_TX] = dpo->dpoi_index;
	}
	}
	else /* transport mode */
	{
	u8 l2_hdr, l2_len, ip_hdr, ip_len;
	udp_header_t *udp = 0;
	u8 *old_ip_hdr = vlib_buffer_get_current (b[0]);

	ip_len = is_ip6 ?
	esp_get_ip6_hdr_len ((ip6_header_t *) old_ip_hdr) :
	ip4_header_bytes ((ip4_header_t *) old_ip_hdr);

	vlib_buffer_advance (b[0], ip_len);
	payload = vlib_buffer_get_current (b[0]);
	next_hdr_ptr = esp_add_footer_and_icv (b[0], block_sz, icv_sz);
	payload_len = b[0]->current_length;

	if (esp_trailer_icv_overflow (node, b[0], next, buffer_data_size))
	goto trace;

	/* ESP header */
	hdr_len += sizeof (*esp);
	esp = (esp_header_t *) (payload - hdr_len);

	/* optional UDP header */
	if (ipsec_sa_is_set_UDP_ENCAP (sa0))
	{
	hdr_len += sizeof (udp_header_t);
	udp = (udp_header_t *) (payload - hdr_len);
	}

	/* IP header */
	hdr_len += ip_len;
	ip_hdr = payload - hdr_len;

	/* L2 header */
	l2_len = vnet_buffer (b[0])->ip.save_rewrite_length;
	hdr_len += l2_len;
	l2_hdr = payload - hdr_len;

	/* copy l2 and ip header */
	clib_memcpy_le32 (l2_hdr, old_ip_hdr - l2_len, l2_len);
	clib_memcpy_le64 (ip_hdr, old_ip_hdr, ip_len);

	if (is_ip6)
	{
	ip6_header_t ip6 = (ip6_header_t ) (ip_hdr);
	*next_hdr_ptr = ip6->protocol;
	ip6->protocol = IP_PROTOCOL_IPSEC_ESP;
	ip6->payload_length =
	clib_host_to_net_u16 (payload_len + hdr_len - l2_len -
	ip_len);
	}
	else
	{
	u16 len;
	ip4_header_t ip4 = (ip4_header_t ) (ip_hdr);
	*next_hdr_ptr = ip4->protocol;
	len = payload_len + hdr_len - l2_len;
	if (udp)
	{
	esp_update_ip4_hdr (ip4, len, /* is_transport */ 1, 1);
	esp_fill_udp_hdr (sa0, udp, len - ip_len);
	}
	else
	esp_update_ip4_hdr (ip4, len, /* is_transport */ 1, 0);
	}

	next[0] = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
	}

	esp->spi = spi;
	esp->seq = clib_net_to_host_u32 (sa0->seq);

	if (sa0->crypto_enc_op_id)
	{
	vnet_crypto_op_t *op;
	vec_add2_aligned (ptd->crypto_ops, op, 1, CLIB_CACHE_LINE_BYTES);
	vnet_crypto_op_init (op, sa0->crypto_enc_op_id);
	op->iv = payload - iv_sz;
	op->src = op->dst = payload;
	op->key = sa0->crypto_key.data;
	op->len = payload_len - icv_sz;
	op->flags = VNET_CRYPTO_OP_FLAG_INIT_IV;
	op->user_data = b - bufs;
	op->salt = sa0->salt;

	if (ipsec_sa_is_set_IS_AEAD (sa0))
	{
	/*
	* construct the AAD in a scratch space in front
	* of the IP header.
	*/
	op->aad = payload - hdr_len - sizeof (esp_aead_t);

	esp_aad_fill (op, esp, sa0);

	op->tag = payload + op->len;
	op->tag_len = 16;
	}
	}

	if (sa0->integ_op_id)
	{
	vnet_crypto_op_t *op;
	vec_add2_aligned (ptd->integ_ops, op, 1, CLIB_CACHE_LINE_BYTES);
	vnet_crypto_op_init (op, sa0->integ_op_id);
	op->src = payload - iv_sz - sizeof (esp_header_t);
	op->digest = payload + payload_len - icv_sz;
	op->key = sa0->integ_key.data;
	op->key_len = sa0->integ_key.len;
	op->digest_len = icv_sz;
	op->len = payload_len - icv_sz + iv_sz + sizeof (esp_header_t);
	op->user_data = b - bufs;
	if (ipsec_sa_is_set_USE_ESN (sa0))
	{
	u32 seq_hi = clib_net_to_host_u32 (sa0->seq_hi);
	clib_memcpy_fast (op->digest, &seq_hi, sizeof (seq_hi));
	op->len += sizeof (seq_hi);
	}
	}

	vlib_buffer_advance (b[0], 0LL - hdr_len);

	current_sa_packets += 1;
	current_sa_bytes += payload_len;

	trace:
	if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
	{
	esp_encrypt_trace_t *tr = vlib_add_trace (vm, node, b[0],
	sizeof (*tr));
	tr->sa_index = sa_index0;
	tr->spi = sa0->spi;
	tr->seq = sa0->seq - 1;
	tr->udp_encap = ipsec_sa_is_set_UDP_ENCAP (sa0);
	tr->crypto_alg = sa0->crypto_alg;
	tr->integ_alg = sa0->integ_alg;
	}
	/* next */
	n_left -= 1;
	next += 1;
	b += 1;
	}

	vlib_increment_combined_counter (&ipsec_sa_counters, thread_index,
	current_sa_index, current_sa_packets,
	current_sa_bytes);
	esp_process_ops (vm, node, ptd->crypto_ops, bufs, nexts);
	esp_process_ops (vm, node, ptd->integ_ops, bufs, nexts);

	vlib_node_increment_counter (vm, node->node_index,
	ESP_ENCRYPT_ERROR_RX_PKTS, frame->n_vectors);

	vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
	return frame->n_vectors;
	}

	VLIB_NODE_FN (esp4_encrypt_node) (vlib_main_t * vm,
	vlib_node_runtime_t * node,
	vlib_frame_t * from_frame)
	{
	return esp_encrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ , 0);
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (esp4_encrypt_node) = {
	.name = "esp4-encrypt",
	.vector_size = sizeof (u32),
	.format_trace = format_esp_encrypt_trace,
	.type = VLIB_NODE_TYPE_INTERNAL,

	.n_errors = ARRAY_LEN(esp_encrypt_error_strings),
	.error_strings = esp_encrypt_error_strings,

	.n_next_nodes = ESP_ENCRYPT_N_NEXT,
	.next_nodes = {
	#define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
	foreach_esp_encrypt_next
	#undef _
	},
	};
	/* INDENT-ON */

	VLIB_NODE_FN (esp6_encrypt_node) (vlib_main_t * vm,
	vlib_node_runtime_t * node,
	vlib_frame_t * from_frame)
	{
	return esp_encrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ , 0);
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (esp6_encrypt_node) = {
	.name = "esp6-encrypt",
	.vector_size = sizeof (u32),
	.format_trace = format_esp_encrypt_trace,
	.type = VLIB_NODE_TYPE_INTERNAL,

	.n_errors = ARRAY_LEN(esp_encrypt_error_strings),
	.error_strings = esp_encrypt_error_strings,

	.n_next_nodes = ESP_ENCRYPT_N_NEXT,
	.next_nodes = {
	#define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
	foreach_esp_encrypt_next
	#undef _
	},
	};
	/* INDENT-ON */

	VLIB_NODE_FN (esp4_encrypt_tun_node) (vlib_main_t * vm,
	vlib_node_runtime_t * node,
	vlib_frame_t * from_frame)
	{
	return esp_encrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ , 1);
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (esp4_encrypt_tun_node) = {
	.name = "esp4-encrypt-tun",
	.vector_size = sizeof (u32),
	.format_trace = format_esp_encrypt_trace,
	.type = VLIB_NODE_TYPE_INTERNAL,

	.n_errors = ARRAY_LEN(esp_encrypt_error_strings),
	.error_strings = esp_encrypt_error_strings,

	.n_next_nodes = 1,
	.next_nodes = {
	[ESP_ENCRYPT_NEXT_DROP] = "ip4-drop",
	},
	};

	VNET_FEATURE_INIT (esp4_encrypt_tun_feat_node, static) =
	{
	.arc_name = "ip4-output",
	.node_name = "esp4-encrypt-tun",
	.runs_before = VNET_FEATURES ("adj-midchain-tx"),
	};
	/* INDENT-ON */

	VLIB_NODE_FN (esp6_encrypt_tun_node) (vlib_main_t * vm,
	vlib_node_runtime_t * node,
	vlib_frame_t * from_frame)
	{
	return esp_encrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ , 1);
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (esp6_encrypt_tun_node) = {
	.name = "esp6-encrypt-tun",
	.vector_size = sizeof (u32),
	.format_trace = format_esp_encrypt_trace,
	.type = VLIB_NODE_TYPE_INTERNAL,

	.n_errors = ARRAY_LEN(esp_encrypt_error_strings),
	.error_strings = esp_encrypt_error_strings,

	.n_next_nodes = 1,
	.next_nodes = {
	[ESP_ENCRYPT_NEXT_DROP] = "ip6-drop",
	},
	};

	VNET_FEATURE_INIT (esp6_encrypt_tun_feat_node, static) =
	{
	.arc_name = "ip6-output",
	.node_name = "esp6-encrypt-tun",
	.runs_before = VNET_FEATURES ("adj-midchain-tx"),
	};
	/* INDENT-ON */

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/