ipsec: Revert "ipsec: fix chained ESP"

This reverts commit c2c1bfd9b72aec88526c06479b128725eb525866.

Reason for revert: Seems it's breaking ipsec esp tests

Type: fix

Change-Id: Iac590eee23cbf92a10c62dafa789aa9c3b2284dd
Signed-off-by: Florin Coras <fcoras@cisco.com>

3 files changed, 51 insertions, 146 deletions

diff --git a/src/vnet/ipsec/esp_decrypt.c b/src/vnet/ipsec/esp_decrypt.c
index 986087ba462..36689480538 100644
--- a/src/vnet/ipsec/esp_decrypt.c
+++ b/src/vnet/ipsec/esp_decrypt.c
@@ -214,7 +214,7 @@ esp_remove_tail (vlib_main_t * vm, vlib_buffer_t * b, vlib_buffer_t * last,
    return pointer to it */
 static_always_inline u8 *
 esp_move_icv (vlib_main_t * vm, vlib_buffer_t * first,
-	      esp_decrypt_packet_data_t * pd, u16 icv_sz, u16 * dif)
+	      esp_decrypt_packet_data_t * pd, u16 icv_sz)
 {
   vlib_buffer_t *before_last, *bp;
   u16 last_sz = pd->lb->current_length;
@@ -232,8 +232,6 @@ esp_move_icv (vlib_main_t * vm, vlib_buffer_t * first,
   clib_memcpy_fast (lb_curr, vlib_buffer_get_tail (before_last) - first_sz,
 		    first_sz);
   before_last->current_length -= first_sz;
-  if (dif)
-    dif[0] = first_sz;
   pd->lb = before_last;
   pd->icv_removed = 1;
   pd->free_buffer_index = before_last->next_buffer;
@@ -241,76 +239,6 @@ esp_move_icv (vlib_main_t * vm, vlib_buffer_t * first,
   return lb_curr;
 }
 
-static_always_inline int
-esp_insert_esn (vlib_main_t * vm, ipsec_sa_t * sa,
-		esp_decrypt_packet_data_t * pd, vnet_crypto_op_t * op,
-		u16 * len, vlib_buffer_t * b, u8 * payload)
-{
-  if (!ipsec_sa_is_set_USE_ESN (sa))
-    return 1;
-
-  /* shift ICV by 4 bytes to insert ESN */
-  u32 seq_hi = clib_host_to_net_u32 (sa->seq_hi);
-  u8 tmp[ESP_MAX_ICV_SIZE], sz = sizeof (sa->seq_hi);
-
-  if (pd->icv_removed)
-    {
-      u16 space_left = vlib_buffer_space_left_at_end (vm, pd->lb);
-      if (space_left >= sz)
-	{
-	  clib_memcpy_fast (vlib_buffer_get_tail (pd->lb), &seq_hi, sz);
-	  op->len += sz;
-	}
-      else
-	return 0;
-
-      len[0] = b->current_length;
-    }
-  else
-    {
-      clib_memcpy_fast (tmp, payload + len[0], ESP_MAX_ICV_SIZE);
-      clib_memcpy_fast (payload + len[0], &seq_hi, sz);
-      clib_memcpy_fast (payload + len[0] + sz, tmp, ESP_MAX_ICV_SIZE);
-      op->len += sz;
-      op->digest += sz;
-    }
-  return 1;
-}
-
-static_always_inline u8 *
-esp_move_icv_esn (vlib_main_t * vm, vlib_buffer_t * first,
-		  esp_decrypt_packet_data_t * pd, u16 icv_sz, ipsec_sa_t * sa,
-		  u8 * extra_esn, vnet_crypto_op_t * op)
-{
-  u16 dif = 0;
-  u8 *digest = esp_move_icv (vm, first, pd, icv_sz, &dif);
-  if (dif)
-    op->len -= dif;
-
-  if (ipsec_sa_is_set_USE_ESN (sa))
-    {
-      u8 sz = sizeof (sa->seq_hi);
-      u32 seq_hi = clib_host_to_net_u32 (sa->seq_hi);
-      u16 space_left = vlib_buffer_space_left_at_end (vm, pd->lb);
-
-      if (space_left >= sz)
-	{
-	  clib_memcpy_fast (vlib_buffer_get_tail (pd->lb), &seq_hi, sz);
-	  op->len += sz;
-	}
-      else
-	{
-	  /* no space for ESN at the tail, use the next buffer
-	   * (with ICV data) */
-	  ASSERT (pd->icv_removed);
-	  vlib_buffer_t *tmp = vlib_get_buffer (vm, pd->free_buffer_index);
-	  clib_memcpy_fast (vlib_buffer_get_current (tmp) - sz, &seq_hi, sz);
-	  extra_esn[0] = 1;
-	}
-    }
-  return digest;
-}
-
 always_inline uword
 esp_decrypt_inline (vlib_main_t * vm,
 		    vlib_node_runtime_t * node, vlib_frame_t * from_frame,
@@ -318,6 +246,7 @@ esp_decrypt_inline (vlib_main_t * vm,
 {
   ipsec_main_t *im = &ipsec_main;
   u32 thread_index = vm->thread_index;
+  u16 buffer_data_size = vlib_buffer_get_default_data_size (vm);
   u16 len;
   ipsec_per_thread_data_t *ptd = vec_elt_at_index (im->ptd, thread_index);
   u32 *from = vlib_frame_vector_args (from_frame);
@@ -329,7 +258,6 @@ esp_decrypt_inline (vlib_main_t * vm,
   u32 current_sa_index = ~0, current_sa_bytes = 0, current_sa_pkts = 0;
   const u8 esp_sz = sizeof (esp_header_t);
   ipsec_sa_t *sa0 = 0;
-  vnet_crypto_op_t _op, *op = &_op;
   vnet_crypto_op_chunk_t *ch;
   vnet_crypto_op_t **crypto_ops = &ptd->crypto_ops;
   vnet_crypto_op_t **integ_ops = &ptd->integ_ops;
@@ -399,6 +327,7 @@ esp_decrypt_inline (vlib_main_t * vm,
       /* store packet data for next round for easier prefetch */
       pd->sa_data = cpd.sa_data;
       pd->current_data = b[0]->current_data;
+      pd->current_length = b[0]->current_length;
       pd->hdr_sz = pd->current_data - vnet_buffer (b[0])->l3_hdr_offset;
       payload = b[0]->data + pd->current_data;
       pd->seq = clib_host_to_net_u32 (((esp_header_t *) payload)->seq);
@@ -417,6 +346,17 @@ esp_decrypt_inline (vlib_main_t * vm,
 	}
       pd->current_length = b[0]->current_length;
 
+      /* we need 4 extra bytes for HMAC calculation when ESN are used */
+      /* Chained buffers can process ESN as a separate chunk */
+      if (pd->lb == b[0] && ipsec_sa_is_set_USE_ESN (sa0) && cpd.icv_sz &&
+	  (pd->lb->current_data + pd->lb->current_length + 4
+	   > buffer_data_size))
+	{
+	  b[0]->error = node->errors[ESP_DECRYPT_ERROR_NO_TAIL_SPACE];
+	  next[0] = ESP_DECRYPT_NEXT_DROP;
+	  goto next;
+	}
+
       /* anti-reply check */
       if (ipsec_sa_anti_replay_check (sa0, pd->seq))
 	{
@@ -438,6 +378,9 @@ esp_decrypt_inline (vlib_main_t * vm,
 
       if (PREDICT_TRUE (sa0->integ_op_id != VNET_CRYPTO_OP_NONE))
 	{
+	  vnet_crypto_op_t *op;
+	  vec_add2_aligned (integ_ops[0], op, 1, CLIB_CACHE_LINE_BYTES);
+
 	  vnet_crypto_op_init (op, sa0->integ_op_id);
 	  op->key_index = sa0->integ_key_index;
 	  op->src = payload;
@@ -451,42 +394,14 @@ esp_decrypt_inline (vlib_main_t * vm,
 	    {
 	      /* buffer is chained */
 	      vlib_buffer_t *cb = b[0];
-	      op->len = pd->current_length;
+	      op->flags |= VNET_CRYPTO_OP_FLAG_CHAINED_BUFFERS;
+	      op->chunk_index = vec_len (ptd->chunks);
 
-	      /* special case when ICV is splitted and needs to be reassembled
-	       * first -> move it to the last buffer. Also take into account
-	       * that ESN needs to be added after encrypted data and may or
-	       * may not fit in the tail.*/
 	      if (pd->lb->current_length < cpd.icv_sz)
-		{
-		  u8 extra_esn = 0;
-		  op->digest =
-		    esp_move_icv_esn (vm, b[0], pd, cpd.icv_sz, sa0,
-				      &extra_esn, op);
-
-		  if (extra_esn)
-		    {
-		      /* esn is in the last buffer, that was unlinked from
-		       * the chain */
-		      op->len = b[0]->current_length;
-		    }
-		  else
-		    {
-		      if (pd->lb == b[0])
-			{
-			  /* we now have a single buffer of crypto data, adjust
-			   * the length (second buffer contains only ICV) */
-			  integ_ops = &ptd->integ_ops;
-			  crypto_ops = &ptd->crypto_ops;
-			  goto out;
-			}
-		    }
-		}
+		op->digest = esp_move_icv (vm, b[0], pd, cpd.icv_sz);
 	      else
 		op->digest = vlib_buffer_get_tail (pd->lb) - cpd.icv_sz;
 
-	      op->flags |= VNET_CRYPTO_OP_FLAG_CHAINED_BUFFERS;
-	      op->chunk_index = vec_len (ptd->chunks);
 	      vec_add2 (ptd->chunks, ch, 1);
 	      ch->len = pd->current_length;
 	      ch->src = payload;
@@ -557,7 +472,6 @@ esp_decrypt_inline (vlib_main_t * vm,
 			      ch->len += sz;
 			    }
 			}
-		      break;
 		    }
 		  else
 		    ch->len = cb->current_length;
@@ -568,10 +482,17 @@ esp_decrypt_inline (vlib_main_t * vm,
 		  cb = vlib_get_buffer (vm, cb->next_buffer);
 		}
 	    }
-	  else
-	    esp_insert_esn (vm, sa0, pd, op, &len, b[0], payload);
-	out:
-	  vec_add_aligned (integ_ops[0], op, 1, CLIB_CACHE_LINE_BYTES);
+	  else if (ipsec_sa_is_set_USE_ESN (sa0))
+	    {
+	      /* shift ICV by 4 bytes to insert ESN */
+	      u32 seq_hi = clib_host_to_net_u32 (sa0->seq_hi);
+	      u8 tmp[ESP_MAX_ICV_SIZE], sz = sizeof (sa0->seq_hi);
+	      clib_memcpy_fast (tmp, payload + len, ESP_MAX_ICV_SIZE);
+	      clib_memcpy_fast (payload + len, &seq_hi, sz);
+	      clib_memcpy_fast (payload + len + sz, tmp, ESP_MAX_ICV_SIZE);
+	      op->len += sz;
+	      op->digest += sz;
+	    }
 	}
 
       payload += esp_sz;
@@ -579,6 +500,8 @@ esp_decrypt_inline (vlib_main_t * vm,
 
       if (sa0->crypto_dec_op_id != VNET_CRYPTO_OP_NONE)
 	{
+	  vnet_crypto_op_t *op;
+	  vec_add2_aligned (crypto_ops[0], op, 1, CLIB_CACHE_LINE_BYTES);
 	  vnet_crypto_op_init (op, sa0->crypto_dec_op_id);
 	  op->key_index = sa0->crypto_key_index;
 	  op->iv = payload;
@@ -639,9 +562,8 @@ esp_decrypt_inline (vlib_main_t * vm,
 			{
 			  if (pd->lb->current_length < cpd.icv_sz)
 			    {
-			      u16 dif = 0;
 			      op->tag =
-				esp_move_icv (vm, b[0], pd, cpd.icv_sz, &dif);
+				esp_move_icv (vm, b[0], pd, cpd.icv_sz);
 
 			      /* this chunk does not contain crypto data */
 			      op->n_chunks -= 1;
@@ -649,10 +571,7 @@ esp_decrypt_inline (vlib_main_t * vm,
 			      /* and fix previous chunk's length as it might have
 			         been changed */
 			      ASSERT (op->n_chunks > 0);
-			      if (pd->lb == b[0])
-				ch[-1].len -= dif;
-			      else
-				ch[-1].len = pd->lb->current_length;
+			      ch[-1].len = pd->lb->current_length;
 			      break;
 			    }
 			  else
@@ -674,8 +593,6 @@ esp_decrypt_inline (vlib_main_t * vm,
 		  cb = vlib_get_buffer (vm, cb->next_buffer);
 		}
 	    }
-
-	  vec_add_aligned (crypto_ops[0], op, 1, CLIB_CACHE_LINE_BYTES);
 	}
 
       /* next */
@@ -826,7 +743,7 @@ esp_decrypt_inline (vlib_main_t * vm,
 	    clib_memcpy_le64 (ip, old_ip, ip_hdr_sz);
 
 	  b[0]->current_data = pd->current_data + adv - ip_hdr_sz;
-	  b[0]->current_length += ip_hdr_sz - adv;
+	  b[0]->current_length = pd->current_length + ip_hdr_sz - adv;
 	  esp_remove_tail (vm, b[0], pd->lb, tail);
 
 	  if (is_ip6)
diff --git a/src/vnet/ipsec/esp_encrypt.c b/src/vnet/ipsec/esp_encrypt.c
index 9b32d3fc38e..e06babd92ef 100644
--- a/src/vnet/ipsec/esp_encrypt.c
+++ b/src/vnet/ipsec/esp_encrypt.c
@@ -44,6 +44,7 @@ typedef enum
  _(SEQ_CYCLED, "sequence number cycled (packet dropped)")       \
  _(CRYPTO_ENGINE_ERROR, "crypto engine error (packet dropped)") \
  _(NO_BUFFERS, "no buffers (packet dropped)")                   \
+ _(NO_TRAILER_SPACE, "no trailer space (packet dropped)")
 
 typedef enum
 {
@@ -90,8 +91,7 @@ format_esp_encrypt_trace (u8 * s, va_list * args)
 
 /* pad packet in input buffer */
 static_always_inline u8 *
-esp_add_footer_and_icv (vlib_main_t * vm, vlib_buffer_t ** last,
-			u8 block_size, u8 icv_sz,
+esp_add_footer_and_icv (vlib_buffer_t * b, u8 block_size, u8 icv_sz,
 			u16 * next, vlib_node_runtime_t * node,
 			u16 buffer_data_size, uword total_len)
 {
@@ -103,27 +103,18 @@ esp_add_footer_and_icv (vlib_main_t * vm, vlib_buffer_t ** last,
   u16 min_length = total_len + 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 (last[0]) +
-				      last[0]->current_length + pad_bytes);
+  esp_footer_t *f = (esp_footer_t *) (vlib_buffer_get_current (b) +
+				      b->current_length + pad_bytes);
   u16 tail_sz = sizeof (esp_footer_t) + pad_bytes + icv_sz;
 
-  if (last[0]->current_length + tail_sz > buffer_data_size)
+  if (b->current_data + tail_sz > buffer_data_size)
     {
-      u32 tmp_bi = 0;
-      if (vlib_buffer_alloc (vm, &tmp_bi, 1) != 1)
-	return 0;
-
-      vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
-      last[0]->next_buffer = tmp_bi;
-      last[0]->flags |= VLIB_BUFFER_NEXT_PRESENT;
-      f = (esp_footer_t *) (vlib_buffer_get_current (tmp) + pad_bytes);
-      tmp->current_length += tail_sz;
-      last[0] = tmp;
+      // TODO alloc new buffer
+      b->error = node->errors[ESP_ENCRYPT_ERROR_NO_TRAILER_SPACE];
+      next[0] = ESP_ENCRYPT_NEXT_DROP;
+      return 0;
     }
-  else
-    last[0]->current_length += tail_sz;
 
-  f->pad_length = pad_bytes;
   if (pad_bytes)
     {
       ASSERT (pad_bytes <= ESP_MAX_BLOCK_SIZE);
@@ -131,6 +122,8 @@ esp_add_footer_and_icv (vlib_main_t * vm, vlib_buffer_t ** last,
       clib_memcpy_fast ((u8 *) f - pad_bytes, pad_data, pad_bytes);
     }
 
+  f->pad_length = pad_bytes;
+  b->current_length += tail_sz;
   return &f->next_header;
 }
 
@@ -409,17 +402,13 @@ esp_encrypt_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
       if (ipsec_sa_is_set_IS_TUNNEL (sa0))
 	{
 	  payload = vlib_buffer_get_current (b[0]);
-	  next_hdr_ptr = esp_add_footer_and_icv (vm, &lb, block_sz, icv_sz,
+	  next_hdr_ptr = esp_add_footer_and_icv (lb, block_sz, icv_sz,
 						 next, node,
 						 buffer_data_size,
 						 vlib_buffer_length_in_chain
 						 (vm, b[0]));
 	  if (!next_hdr_ptr)
-	    {
-	      b[0]->error = node->errors[ESP_ENCRYPT_ERROR_NO_BUFFERS];
-	      next[0] = ESP_ENCRYPT_NEXT_DROP;
-	      goto trace;
-	    }
+	    goto trace;
 	  b[0]->flags &= ~VLIB_BUFFER_TOTAL_LENGTH_VALID;
 	  payload_len = b[0]->current_length;
 	  payload_len_total = vlib_buffer_length_in_chain (vm, b[0]);
@@ -482,7 +471,7 @@ esp_encrypt_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 
 	  vlib_buffer_advance (b[0], ip_len);
 	  payload = vlib_buffer_get_current (b[0]);
-	  next_hdr_ptr = esp_add_footer_and_icv (vm, &lb, block_sz, icv_sz,
+	  next_hdr_ptr = esp_add_footer_and_icv (lb, block_sz, icv_sz,
 						 next, node,
 						 buffer_data_size,
 						 vlib_buffer_length_in_chain
diff --git a/test/test_ipsec_esp.py b/test/test_ipsec_esp.py
index cd5a88c1969..5b057e750cc 100644
--- a/test/test_ipsec_esp.py
+++ b/test/test_ipsec_esp.py
@@ -509,10 +509,9 @@ class RunTestIpsecEspAll(ConfigIpsecESP,
                            count=NUM_PKTS)
 
         LARGE_PKT_SZ = [
-            1970,  # results in 2 chained buffers entering decrypt node
-                   # but leaving as simple buffer due to ICV removal (tra4)
             4010,  # ICV ends up splitted accross 2 buffers in esp_decrypt
                    # for transport4; transport6 takes normal path
+
             4020,  # same as above but tra4 and tra6 are switched
         ]
         if self.engine in engines_supporting_chain_bufs: