ipsec: ipsec-tun protect

please consult the new tunnel proposal at:
  https://wiki.fd.io/view/VPP/IPSec

Type: feature

Change-Id: I52857fc92ae068b85f59be08bdbea1bd5932e291
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 436 insertions, 0 deletions

diff --git a/src/vnet/ipsec/ipsec_tun_in.c b/src/vnet/ipsec/ipsec_tun_in.c
new file mode 100644
index 00000000000..2ce1691b242
--- /dev/null
+++ b/src/vnet/ipsec/ipsec_tun_in.c
@@ -0,0 +1,436 @@
+/*
+ * ipsec_tun_protect_in.c : IPSec interface input 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/ipsec_io.h>
+#include <vnet/ipsec/ipsec_punt.h>
+#include <vnet/ipsec/ipsec_tun.h>
+#include <vnet/ip/ip4_input.h>
+
+/* Statistics (not really errors) */
+#define foreach_ipsec_tun_protect_input_error                     \
+  _(RX, "good packets received")                                  \
+  _(DISABLED, "ipsec packets received on disabled interface")     \
+  _(NO_TUNNEL, "no matching tunnel")                              \
+  _(TUNNEL_MISMATCH, "SPI-tunnel mismatch")                       \
+  _(SPI_0, "SPI 0")
+
+static char *ipsec_tun_protect_input_error_strings[] = {
+#define _(sym,string) string,
+  foreach_ipsec_tun_protect_input_error
+#undef _
+};
+
+typedef enum
+{
+#define _(sym,str) IPSEC_TUN_PROTECT_INPUT_ERROR_##sym,
+  foreach_ipsec_tun_protect_input_error
+#undef _
+    IPSEC_TUN_PROTECT_INPUT_N_ERROR,
+} ipsec_tun_protect_input_error_t;
+
+typedef enum ipsec_tun_next_t_
+{
+#define _(v, s) IPSEC_TUN_PROTECT_NEXT_##v,
+  foreach_ipsec_input_next
+#undef _
+    IPSEC_TUN_PROTECT_NEXT_DECRYPT,
+  IPSEC_TUN_PROTECT_N_NEXT,
+} ipsec_tun_next_t;
+
+typedef struct
+{
+  u32 spi;
+  u32 seq;
+} ipsec_tun_protect_input_trace_t;
+
+static u8 *
+format_ipsec_tun_protect_input_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 *);
+  ipsec_tun_protect_input_trace_t *t =
+    va_arg (*args, ipsec_tun_protect_input_trace_t *);
+
+  s = format (s, "IPSec: spi %u seq %u", t->spi, t->seq);
+  return s;
+}
+
+always_inline u16
+ipsec_ip4_if_no_tunnel (vlib_node_runtime_t * node,
+			vlib_buffer_t * b,
+			const esp_header_t * esp, const ip4_header_t * ip4)
+{
+  if (PREDICT_FALSE (0 == esp->spi))
+    {
+      b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_SPI_0];
+      b->punt_reason = ipsec_punt_reason[(ip4->protocol == IP_PROTOCOL_UDP ?
+					  IPSEC_PUNT_IP4_SPI_UDP_0 :
+					  IPSEC_PUNT_IP4_SPI_0)];
+    }
+  else
+    {
+      b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NO_TUNNEL];
+      b->punt_reason = ipsec_punt_reason[IPSEC_PUNT_IP4_NO_SUCH_TUNNEL];
+    }
+  return IPSEC_INPUT_NEXT_PUNT;
+}
+
+always_inline u16
+ipsec_ip6_if_no_tunnel (vlib_node_runtime_t * node,
+			vlib_buffer_t * b, const esp_header_t * esp)
+{
+  if (PREDICT_FALSE (0 == esp->spi))
+    {
+      b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NO_TUNNEL];
+      b->punt_reason = ipsec_punt_reason[IPSEC_PUNT_IP6_SPI_0];
+    }
+  else
+    {
+      b->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_NO_TUNNEL];
+      b->punt_reason = ipsec_punt_reason[IPSEC_PUNT_IP6_NO_SUCH_TUNNEL];
+    }
+  return (IPSEC_INPUT_NEXT_PUNT);
+}
+
+always_inline uword
+ipsec_tun_protect_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+				vlib_frame_t * from_frame, int is_ip6)
+{
+  ipsec_main_t *im = &ipsec_main;
+  vnet_main_t *vnm = im->vnet_main;
+  vnet_interface_main_t *vim = &vnm->interface_main;
+
+  int is_trace = node->flags & VLIB_NODE_FLAG_TRACE;
+  u32 thread_index = vm->thread_index;
+
+  u32 n_left_from, *from;
+  u16 nexts[VLIB_FRAME_SIZE], *next;
+  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
+
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+
+  vlib_get_buffers (vm, from, bufs, n_left_from);
+  b = bufs;
+  next = nexts;
+
+  clib_memset_u16 (nexts, im->esp4_decrypt_next_index, n_left_from);
+
+  u64 n_bytes = 0, n_packets = 0;
+  u32 n_disabled = 0, n_no_tunnel = 0;
+
+  u32 last_sw_if_index = ~0;
+  ipsec_tun_lkup_result_t last_result = {
+    .tun_index = ~0
+  };
+  ipsec4_tunnel_key_t last_key4;
+  ipsec6_tunnel_key_t last_key6;
+
+  vlib_combined_counter_main_t *rx_counter;
+  vlib_combined_counter_main_t *drop_counter;
+  ipsec_tun_protect_t *itp0;
+
+  if (is_ip6)
+    clib_memset (&last_key6, 0xff, sizeof (last_key6));
+  else
+    last_key4.as_u64 = ~0;
+
+  rx_counter = vim->combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX;
+  drop_counter = vim->combined_sw_if_counters + VNET_INTERFACE_COUNTER_DROP;
+
+  while (n_left_from > 0)
+    {
+      u32 sw_if_index0, len0, hdr_sz0;
+      ipsec_tun_lkup_result_t itr0;
+      ipsec4_tunnel_key_t key40;
+      ipsec6_tunnel_key_t key60;
+      ip4_header_t *ip40;
+      ip6_header_t *ip60;
+      esp_header_t *esp0;
+
+      ip40 = vlib_buffer_get_current (b[0]);
+
+      if (is_ip6)
+	{
+	  ip60 = (ip6_header_t *) ip40;
+	  esp0 = (esp_header_t *) (ip60 + 1);
+	  hdr_sz0 = sizeof (ip6_header_t);
+	}
+      else
+	{
+	  /* NAT UDP port 4500 case, don't advance any more */
+	  if (ip40->protocol == IP_PROTOCOL_UDP)
+	    {
+	      esp0 =
+		(esp_header_t *) ((u8 *) ip40 + ip4_header_bytes (ip40) +
+				  sizeof (udp_header_t));
+	      hdr_sz0 = 0;
+	    }
+	  else
+	    {
+	      esp0 = (esp_header_t *) ((u8 *) ip40 + ip4_header_bytes (ip40));
+	      hdr_sz0 = ip4_header_bytes (ip40);
+	    }
+	}
+
+      /* stats for the tunnel include all the data after the IP header
+         just like a norml IP-IP tunnel */
+      vlib_buffer_advance (b[0], hdr_sz0);
+      len0 = vlib_buffer_length_in_chain (vm, b[0]);
+
+      if (is_ip6)
+	{
+	  key60.remote_ip = ip60->src_address;
+	  key60.spi = esp0->spi;
+
+	  if (memcmp (&key60, &last_key6, sizeof (last_key6)) == 0)
+	    {
+	      itr0 = last_result;
+	    }
+	  else
+	    {
+	      uword *p = hash_get_mem (im->tun6_protect_by_key, &key60);
+	      if (p)
+		{
+		  itr0.as_u64 = p[0];
+		  last_result = itr0;
+		  clib_memcpy_fast (&last_key6, &key60, sizeof (key60));
+		}
+	      else
+		{
+		  next[0] = ipsec_ip6_if_no_tunnel (node, b[0], esp0);
+		  n_no_tunnel++;
+		  goto trace00;
+		}
+	    }
+	}
+      else
+	{
+	  key40.remote_ip = ip40->src_address.as_u32;
+	  key40.spi = esp0->spi;
+
+	  if (key40.as_u64 == last_key4.as_u64)
+	    {
+	      itr0 = last_result;
+	    }
+	  else
+	    {
+	      uword *p = hash_get (im->tun4_protect_by_key, key40.as_u64);
+	      if (p)
+		{
+		  itr0.as_u64 = p[0];
+		  last_result = itr0;
+		  last_key4.as_u64 = key40.as_u64;
+		}
+	      else
+		{
+		  next[0] = ipsec_ip4_if_no_tunnel (node, b[0], esp0, ip40);
+		  n_no_tunnel++;
+		  goto trace00;
+		}
+	    }
+	}
+
+      itp0 = pool_elt_at_index (ipsec_protect_pool, itr0.tun_index);
+      vnet_buffer (b[0])->ipsec.sad_index = itr0.sa_index;
+      vnet_buffer (b[0])->ipsec.protect_index = itr0.tun_index;
+
+      sw_if_index0 = itp0->itp_sw_if_index;
+      vnet_buffer (b[0])->sw_if_index[VLIB_RX] = sw_if_index0;
+
+      if (PREDICT_FALSE (!vnet_sw_interface_is_admin_up (vnm, sw_if_index0)))
+	{
+	  vlib_increment_combined_counter
+	    (drop_counter, thread_index, sw_if_index0, 1, len0);
+	  n_disabled++;
+	  b[0]->error = node->errors[IPSEC_TUN_PROTECT_INPUT_ERROR_DISABLED];
+	  next[0] = IPSEC_INPUT_NEXT_DROP;
+	  goto trace00;
+	}
+      else
+	{
+	  if (PREDICT_TRUE (sw_if_index0 == last_sw_if_index))
+	    {
+	      n_packets++;
+	      n_bytes += len0;
+	    }
+	  else
+	    {
+	      if (n_packets && !(itp0->itp_flags & IPSEC_PROTECT_ENCAPED))
+		{
+		  vlib_increment_combined_counter
+		    (rx_counter, thread_index, last_sw_if_index,
+		     n_packets, n_bytes);
+		}
+
+	      last_sw_if_index = sw_if_index0;
+	      n_packets = 1;
+	      n_bytes = len0;
+	    }
+
+	  /*
+	   * compare the packet's outer IP headers to that of the tunnels
+	   */
+	  if (is_ip6)
+	    {
+	      if (PREDICT_FALSE
+		  (!ip46_address_is_equal_v6
+		   (&itp0->itp_crypto.dst, &ip60->src_address)
+		   || !ip46_address_is_equal_v6 (&itp0->itp_crypto.src,
+						 &ip60->dst_address)))
+		{
+		  b[0]->error =
+		    node->errors
+		    [IPSEC_TUN_PROTECT_INPUT_ERROR_TUNNEL_MISMATCH];
+		  next[0] = IPSEC_INPUT_NEXT_DROP;
+		  goto trace00;
+		}
+	    }
+	  else
+	    {
+	      if (PREDICT_FALSE
+		  (!ip46_address_is_equal_v4
+		   (&itp0->itp_crypto.dst, &ip40->src_address)
+		   || !ip46_address_is_equal_v4 (&itp0->itp_crypto.src,
+						 &ip40->dst_address)))
+		{
+		  b[0]->error =
+		    node->errors
+		    [IPSEC_TUN_PROTECT_INPUT_ERROR_TUNNEL_MISMATCH];
+		  next[0] = IPSEC_INPUT_NEXT_DROP;
+		  goto trace00;
+		}
+	    }
+
+	  /*
+	   * There are two encap possibilities
+	   * 1) the tunnel and ths SA are prodiving encap, i.e. it's
+	   *   MAC | SA-IP | TUN-IP | ESP | PAYLOAD
+	   * implying the SA is in tunnel mode (on a tunnel interface)
+	   * 2) only the tunnel provides encap
+	   *   MAC | TUN-IP | ESP | PAYLOAD
+	   * implying the SA is in transport mode.
+	   *
+	   * For 2) we need only strip the tunnel encap and we're good.
+	   *  since the tunnel and crypto ecnap (int the tun=protect
+	   * object) are the same and we verified above that these match
+	   * for 1) we need to strip the SA-IP outer headers, to
+	   * reveal the tunnel IP and then check that this matches
+	   * the configured tunnel. this we can;t do here since it
+	   * involves a lookup in the per-tunnel-type DB - so ship
+	   * the packet to the tunnel-types provided node to do that
+	   */
+	  next[0] = IPSEC_TUN_PROTECT_NEXT_DECRYPT;
+	}
+    trace00:
+      if (PREDICT_FALSE (is_trace))
+	{
+	  if (b[0]->flags & VLIB_BUFFER_IS_TRACED)
+	    {
+	      ipsec_tun_protect_input_trace_t *tr =
+		vlib_add_trace (vm, node, b[0], sizeof (*tr));
+	      tr->spi = clib_host_to_net_u32 (esp0->spi);
+	      tr->seq = clib_host_to_net_u32 (esp0->seq);
+	    }
+	}
+
+      /* next */
+      b += 1;
+      next += 1;
+      n_left_from -= 1;
+    }
+
+  if (n_packets && !(itp0->itp_flags & IPSEC_PROTECT_ENCAPED))
+    {
+      vlib_increment_combined_counter (rx_counter,
+				       thread_index,
+				       last_sw_if_index, n_packets, n_bytes);
+    }
+
+  vlib_node_increment_counter (vm, node->node_index,
+			       IPSEC_TUN_PROTECT_INPUT_ERROR_RX,
+			       from_frame->n_vectors - (n_disabled +
+							n_no_tunnel));
+
+  vlib_buffer_enqueue_to_next (vm, node, from, nexts, from_frame->n_vectors);
+
+  return from_frame->n_vectors;
+}
+
+VLIB_NODE_FN (ipsec4_tun_input_node) (vlib_main_t * vm,
+				      vlib_node_runtime_t * node,
+				      vlib_frame_t * from_frame)
+{
+  return ipsec_tun_protect_input_inline (vm, node, from_frame,
+					 0 /* is_ip6 */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ipsec4_tun_input_node) = {
+  .name = "ipsec4-tun-input",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_tun_protect_input_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_tun_protect_input_error_strings),
+  .error_strings = ipsec_tun_protect_input_error_strings,
+  .n_next_nodes = IPSEC_TUN_PROTECT_N_NEXT,
+  .next_nodes = {
+    [IPSEC_TUN_PROTECT_NEXT_DROP] = "ip4-drop",
+    [IPSEC_TUN_PROTECT_NEXT_PUNT] = "punt-dispatch",
+    [IPSEC_TUN_PROTECT_NEXT_DECRYPT] = "esp4-decrypt-tun",
+  }
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FN (ipsec6_tun_input_node) (vlib_main_t * vm,
+				      vlib_node_runtime_t * node,
+				      vlib_frame_t * from_frame)
+{
+  return ipsec_tun_protect_input_inline (vm, node, from_frame,
+					 1 /* is_ip6 */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ipsec6_tun_input_node) = {
+  .name = "ipsec6-tun-input",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ipsec_tun_protect_input_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN(ipsec_tun_protect_input_error_strings),
+  .error_strings = ipsec_tun_protect_input_error_strings,
+  .n_next_nodes = IPSEC_TUN_PROTECT_N_NEXT,
+  .next_nodes = {
+    [IPSEC_TUN_PROTECT_NEXT_DROP] = "ip6-drop",
+    [IPSEC_TUN_PROTECT_NEXT_PUNT] = "punt-dispatch",
+    [IPSEC_TUN_PROTECT_NEXT_DECRYPT] = "esp6-decrypt-tun",
+  }
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */