IPSec AH protocol enhancement in VPP native core

Change-Id: Iec5804d768485f4015bbf732d8d19ef2f24e6939
Signed-off-by: “mukeshyadav1984” <mukyadav@cisco.com>

1 files changed, 343 insertions, 0 deletions

diff --git a/src/vnet/ipsec/ah_decrypt.c b/src/vnet/ipsec/ah_decrypt.c
new file mode 100644
index 00000000000..c487d82e34a
--- /dev/null
+++ b/src/vnet/ipsec/ah_decrypt.c
@@ -0,0 +1,343 @@
+/*
+ * ah_decrypt.c : IPSec AH decrypt 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/ipsec/ipsec.h>
+#include <vnet/ipsec/esp.h>
+#include <vnet/ipsec/ah.h>
+
+#define foreach_ah_decrypt_next                \
+_(DROP, "error-drop")                           \
+_(IP4_INPUT, "ip4-input")                       \
+_(IP6_INPUT, "ip6-input")                       \
+_(IPSEC_GRE_INPUT, "ipsec-gre-input")
+
+#define _(v, s) AH_DECRYPT_NEXT_##v,
+typedef enum
+{
+  foreach_ah_decrypt_next
+#undef _
+    AH_DECRYPT_N_NEXT,
+} ah_decrypt_next_t;
+
+
+#define foreach_ah_decrypt_error                   \
+ _(RX_PKTS, "AH pkts received")                    \
+ _(DECRYPTION_FAILED, "AH decryption failed")      \
+ _(INTEG_ERROR, "Integrity check failed")           \
+ _(REPLAY, "SA replayed packet")                    \
+ _(NOT_IP, "Not IP packet (dropped)")
+
+
+typedef enum
+{
+#define _(sym,str) AH_DECRYPT_ERROR_##sym,
+  foreach_ah_decrypt_error
+#undef _
+    AH_DECRYPT_N_ERROR,
+} ah_decrypt_error_t;
+
+static char *ah_decrypt_error_strings[] = {
+#define _(sym,string) string,
+  foreach_ah_decrypt_error
+#undef _
+};
+
+typedef struct
+{
+  ipsec_integ_alg_t integ_alg;
+} ah_decrypt_trace_t;
+
+/* packet trace format function */
+static u8 *
+format_ah_decrypt_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 *);
+  ah_decrypt_trace_t *t = va_arg (*args, ah_decrypt_trace_t *);
+
+  s = format (s, "ah: integrity %U", format_ipsec_integ_alg, t->integ_alg);
+  return s;
+}
+
+static uword
+ah_decrypt_node_fn (vlib_main_t * vm,
+		    vlib_node_runtime_t * node, vlib_frame_t * from_frame)
+{
+  u32 n_left_from, *from, next_index, *to_next;
+  ipsec_main_t *im = &ipsec_main;
+  ipsec_proto_main_t *em = &ipsec_proto_main;
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+  int icv_size = 0;
+
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 i_bi0;
+	  u32 next0;
+	  vlib_buffer_t *i_b0;
+	  ah_header_t *ah0;
+	  ipsec_sa_t *sa0;
+	  u32 sa_index0 = ~0;
+	  u32 seq;
+	  ip4_header_t *ih4 = 0, *oh4 = 0;
+	  ip6_header_t *ih6 = 0, *oh6 = 0;
+	  u8 tunnel_mode = 1;
+	  u8 transport_ip6 = 0;
+	  u8 ip_hdr_size = 0;
+	  u8 tos = 0;
+	  u8 ttl = 0;
+
+
+	  i_bi0 = from[0];
+	  from += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  next0 = AH_DECRYPT_NEXT_DROP;
+
+	  i_b0 = vlib_get_buffer (vm, i_bi0);
+	  to_next[0] = i_bi0;
+	  to_next += 1;
+	  ih4 = vlib_buffer_get_current (i_b0);
+	  ip_hdr_size = ip4_header_bytes (ih4);
+	  ah0 = (ah_header_t *) ((u8 *) ih4 + ip_hdr_size);
+
+	  sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
+	  sa0 = pool_elt_at_index (im->sad, sa_index0);
+
+	  seq = clib_host_to_net_u32 (ah0->seq_no);
+	  /* anti-replay check */
+	  //TODO UT remaining
+	  if (sa0->use_anti_replay)
+	    {
+	      int rv = 0;
+
+	      if (PREDICT_TRUE (sa0->use_esn))
+		rv = esp_replay_check_esn (sa0, seq);
+	      else
+		rv = esp_replay_check (sa0, seq);
+
+	      if (PREDICT_FALSE (rv))
+		{
+		  clib_warning ("anti-replay SPI %u seq %u", sa0->spi, seq);
+		  vlib_node_increment_counter (vm, ah_decrypt_node.index,
+					       AH_DECRYPT_ERROR_REPLAY, 1);
+		  to_next[0] = i_bi0;
+		  to_next += 1;
+		  goto trace;
+		}
+	    }
+
+
+	  sa0->total_data_size += i_b0->current_length;
+	  icv_size =
+	    em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
+	  if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
+	    {
+	      u8 sig[64];
+	      u8 digest[64];
+	      memset (sig, 0, sizeof (sig));
+	      memset (digest, 0, sizeof (digest));
+	      u8 *icv =
+		vlib_buffer_get_current (i_b0) + ip_hdr_size +
+		sizeof (ah_header_t);
+	      memcpy (digest, icv, icv_size);
+	      memset (icv, 0, icv_size);
+
+	      if ((ih4->ip_version_and_header_length & 0xF0) == 0x40)
+		{
+		  tos = ih4->tos;
+		  ttl = ih4->ttl;
+		  ih4->tos = 0;
+		  ih4->ttl = 0;
+		  ih4->checksum = 0;
+		  ih4->flags_and_fragment_offset = 0;
+		}		//TODO else part for IPv6
+	      hmac_calc (sa0->integ_alg, sa0->integ_key, sa0->integ_key_len,
+			 (u8 *) ih4, i_b0->current_length, sig, sa0->use_esn,
+			 sa0->seq_hi);
+
+	      if (PREDICT_FALSE (memcmp (digest, sig, icv_size)))
+		{
+		  vlib_node_increment_counter (vm, ah_decrypt_node.index,
+					       AH_DECRYPT_ERROR_INTEG_ERROR,
+					       1);
+		  to_next[0] = i_bi0;
+		  to_next += 1;
+		  goto trace;
+		}
+
+	      //TODO UT remaining
+	      if (PREDICT_TRUE (sa0->use_anti_replay))
+		{
+		  if (PREDICT_TRUE (sa0->use_esn))
+		    esp_replay_advance_esn (sa0, seq);
+		  else
+		    esp_replay_advance (sa0, seq);
+		}
+
+	    }
+
+
+	  vlib_buffer_advance (i_b0,
+			       ip_hdr_size + sizeof (ah_header_t) + icv_size);
+	  i_b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
+
+	  /* transport mode */
+	  if (PREDICT_FALSE (!sa0->is_tunnel && !sa0->is_tunnel_ip6))
+	    {
+	      tunnel_mode = 0;
+
+	      if (PREDICT_TRUE
+		  ((ih4->ip_version_and_header_length & 0xF0) != 0x40))
+		{
+		  if (PREDICT_TRUE
+		      ((ih4->ip_version_and_header_length & 0xF0) == 0x60))
+		    transport_ip6 = 1;
+		  else
+		    {
+		      clib_warning ("next header: 0x%x", ah0->nexthdr);
+		      vlib_node_increment_counter (vm, ah_decrypt_node.index,
+						   AH_DECRYPT_ERROR_NOT_IP,
+						   1);
+		      goto trace;
+		    }
+		}
+	    }
+
+	  if (PREDICT_TRUE (tunnel_mode))
+	    {
+	      if (PREDICT_TRUE (ah0->nexthdr == IP_PROTOCOL_IP_IN_IP))
+		next0 = AH_DECRYPT_NEXT_IP4_INPUT;
+	      else if (ah0->nexthdr == IP_PROTOCOL_IPV6)
+		next0 = AH_DECRYPT_NEXT_IP6_INPUT;
+	      else
+		{
+		  clib_warning ("next header: 0x%x", ah0->nexthdr);
+		  vlib_node_increment_counter (vm, ah_decrypt_node.index,
+					       AH_DECRYPT_ERROR_DECRYPTION_FAILED,
+					       1);
+		  goto trace;
+		}
+	    }
+	  /* transport mode */
+	  else
+	    {
+	      if (PREDICT_FALSE (transport_ip6))
+		{
+		  ih6 =
+		    (ip6_header_t *) (i_b0->data +
+				      sizeof (ethernet_header_t));
+		  vlib_buffer_advance (i_b0, -sizeof (ip6_header_t));
+		  oh6 = vlib_buffer_get_current (i_b0);
+		  memmove (oh6, ih6, sizeof (ip6_header_t));
+
+		  next0 = AH_DECRYPT_NEXT_IP6_INPUT;
+		  oh6->protocol = ah0->nexthdr;
+		  oh6->payload_length =
+		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
+					  (vm, i_b0) - sizeof (ip6_header_t));
+		}
+	      else
+		{
+		  vlib_buffer_advance (i_b0, -sizeof (ip4_header_t));
+		  oh4 = vlib_buffer_get_current (i_b0);
+		  memmove (oh4, ih4, sizeof (ip4_header_t));
+
+		  next0 = AH_DECRYPT_NEXT_IP4_INPUT;
+		  oh4->ip_version_and_header_length = 0x45;
+		  oh4->fragment_id = 0;
+		  oh4->flags_and_fragment_offset = 0;
+		  oh4->protocol = ah0->nexthdr;
+		  oh4->length =
+		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
+					  (vm, i_b0));
+		  oh4->ttl = ttl;
+		  oh4->tos = tos;
+		  oh4->checksum = ip4_header_checksum (oh4);
+		}
+	    }
+
+	  /* for IPSec-GRE tunnel next node is ipsec-gre-input */
+	  if (PREDICT_FALSE
+	      ((vnet_buffer (i_b0)->ipsec.flags) &
+	       IPSEC_FLAG_IPSEC_GRE_TUNNEL))
+	    next0 = AH_DECRYPT_NEXT_IPSEC_GRE_INPUT;
+
+
+	  vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	trace:
+	  if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      i_b0->flags |= VLIB_BUFFER_IS_TRACED;
+	      ah_decrypt_trace_t *tr =
+		vlib_add_trace (vm, node, i_b0, sizeof (*tr));
+	      tr->integ_alg = sa0->integ_alg;
+	    }
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, i_bi0, next0);
+	}
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+  vlib_node_increment_counter (vm, ah_decrypt_node.index,
+			       AH_DECRYPT_ERROR_RX_PKTS,
+			       from_frame->n_vectors);
+
+  return from_frame->n_vectors;
+}
+
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ah_decrypt_node) = {
+  .function = ah_decrypt_node_fn,
+  .name = "ah-decrypt",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ah_decrypt_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
+  .error_strings = ah_decrypt_error_strings,
+
+  .n_next_nodes = AH_DECRYPT_N_NEXT,
+  .next_nodes = {
+#define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
+    foreach_ah_decrypt_next
+#undef _
+  },
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FUNCTION_MULTIARCH (ah_decrypt_node, ah_decrypt_node_fn)
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */