wireguard: initial implementation of wireguard protocol

Type: feature

The main information about plugin you can see in README.md

vpp# wireguard ?
  wireguard create                         wireguard create listen-port <port> private-key <key> src <IP> [generate-key]
  wireguard delete                         wireguard delete <interface>
  wireguard peer add                       wireguard peer add <wg_int> public-key <pub_key_other>endpoint <ip4_dst> allowed-ip <prefix>dst-port [port_dst] persistent-keepalive [keepalive_interval]
  wireguard peer remove                    wireguard peer remove <index>

Change-Id: I85eb0bfc033ccfb2045696398d8a108b1c64b8d9
Signed-off-by: Artem Glazychev <artem.glazychev@xored.com>
Signed-off-by: Damjan Marion <damarion@cisco.com>
Signed-off-by: Jim Thompson <jim@netgate.com>
Signed-off-by: Neale Ranns <nranns@cisco.com>
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 451 insertions, 0 deletions

diff --git a/src/plugins/wireguard/wireguard_input.c b/src/plugins/wireguard/wireguard_input.c
new file mode 100755
index 00000000000..832ad031daa
--- /dev/null
+++ b/src/plugins/wireguard/wireguard_input.c
@@ -0,0 +1,451 @@
+/*
+ * Copyright (c) 2020 Doc.ai 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 <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/pg/pg.h>
+#include <vppinfra/error.h>
+#include <wireguard/wireguard.h>
+
+#include <wireguard/wireguard_send.h>
+#include <wireguard/wireguard_if.h>
+
+#define foreach_wg_input_error                          \
+  _(NONE, "No error")                                   \
+  _(HANDSHAKE_MAC, "Invalid MAC handshake")             \
+  _(PEER, "Peer error")                                 \
+  _(INTERFACE, "Interface error")                       \
+  _(DECRYPTION, "Failed during decryption")             \
+  _(KEEPALIVE_SEND, "Failed while sending Keepalive")   \
+  _(HANDSHAKE_SEND, "Failed while sending Handshake")   \
+  _(UNDEFINED, "Undefined error")
+
+typedef enum
+{
+#define _(sym,str) WG_INPUT_ERROR_##sym,
+  foreach_wg_input_error
+#undef _
+    WG_INPUT_N_ERROR,
+} wg_input_error_t;
+
+static char *wg_input_error_strings[] = {
+#define _(sym,string) string,
+  foreach_wg_input_error
+#undef _
+};
+
+typedef struct
+{
+  message_type_t type;
+  u16 current_length;
+  bool is_keepalive;
+
+} wg_input_trace_t;
+
+u8 *
+format_wg_message_type (u8 * s, va_list * args)
+{
+  message_type_t type = va_arg (*args, message_type_t);
+
+  switch (type)
+    {
+#define _(v,a) case MESSAGE_##v: return (format (s, "%s", a));
+      foreach_wg_message_type
+#undef _
+    }
+  return (format (s, "unknown"));
+}
+
+/* packet trace format function */
+static u8 *
+format_wg_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 *);
+
+  wg_input_trace_t *t = va_arg (*args, wg_input_trace_t *);
+
+  s = format (s, "WG input: \n");
+  s = format (s, "  Type: %U\n", format_wg_message_type, t->type);
+  s = format (s, "  Length: %d\n", t->current_length);
+  s = format (s, "  Keepalive: %s", t->is_keepalive ? "true" : "false");
+
+  return s;
+}
+
+typedef enum
+{
+  WG_INPUT_NEXT_IP4_INPUT,
+  WG_INPUT_NEXT_PUNT,
+  WG_INPUT_NEXT_ERROR,
+  WG_INPUT_N_NEXT,
+} wg_input_next_t;
+
+/* static void */
+/* set_peer_address (wg_peer_t * peer, ip4_address_t ip4, u16 udp_port) */
+/* { */
+/*   if (peer) */
+/*     { */
+/*       ip46_address_set_ip4 (&peer->dst.addr, &ip4); */
+/*       peer->dst.port = udp_port; */
+/*     } */
+/* } */
+
+static wg_input_error_t
+wg_handshake_process (vlib_main_t * vm, wg_main_t * wmp, vlib_buffer_t * b)
+{
+  enum cookie_mac_state mac_state;
+  bool packet_needs_cookie;
+  bool under_load;
+  wg_if_t *wg_if;
+  wg_peer_t *peer = NULL;
+
+  void *current_b_data = vlib_buffer_get_current (b);
+
+  udp_header_t *uhd = current_b_data - sizeof (udp_header_t);
+  ip4_header_t *iph =
+    current_b_data - sizeof (udp_header_t) - sizeof (ip4_header_t);
+  ip4_address_t ip4_src = iph->src_address;
+  u16 udp_src_port = clib_host_to_net_u16 (uhd->src_port);;
+  u16 udp_dst_port = clib_host_to_net_u16 (uhd->dst_port);;
+
+  message_header_t *header = current_b_data;
+  under_load = false;
+
+  wg_if = wg_if_get_by_port (udp_dst_port);
+
+  if (NULL == wg_if)
+    return WG_INPUT_ERROR_INTERFACE;
+
+  if (header->type == MESSAGE_HANDSHAKE_COOKIE)
+    {
+      message_handshake_cookie_t *packet =
+	(message_handshake_cookie_t *) current_b_data;
+      u32 *entry =
+	wg_index_table_lookup (&wmp->index_table, packet->receiver_index);
+      if (entry)
+	{
+	  peer = pool_elt_at_index (wmp->peers, *entry);
+	}
+      if (!peer)
+	return WG_INPUT_ERROR_PEER;
+
+      // TODO: Implement cookie_maker_consume_payload
+
+      return WG_INPUT_ERROR_NONE;
+    }
+
+  u32 len = (header->type == MESSAGE_HANDSHAKE_INITIATION ?
+	     sizeof (message_handshake_initiation_t) :
+	     sizeof (message_handshake_response_t));
+
+  message_macs_t *macs = (message_macs_t *)
+    ((u8 *) current_b_data + len - sizeof (*macs));
+
+  mac_state =
+    cookie_checker_validate_macs (vm, &wg_if->cookie_checker, macs,
+				  current_b_data, len, under_load, ip4_src,
+				  udp_src_port);
+
+  if ((under_load && mac_state == VALID_MAC_WITH_COOKIE)
+      || (!under_load && mac_state == VALID_MAC_BUT_NO_COOKIE))
+    packet_needs_cookie = false;
+  else if (under_load && mac_state == VALID_MAC_BUT_NO_COOKIE)
+    packet_needs_cookie = true;
+  else
+    return WG_INPUT_ERROR_HANDSHAKE_MAC;
+
+  switch (header->type)
+    {
+    case MESSAGE_HANDSHAKE_INITIATION:
+      {
+	message_handshake_initiation_t *message = current_b_data;
+
+	if (packet_needs_cookie)
+	  {
+	    // TODO: Add processing
+	  }
+	noise_remote_t *rp;
+
+	if (noise_consume_initiation
+	    (wmp->vlib_main, &wg_if->local, &rp, message->sender_index,
+	     message->unencrypted_ephemeral, message->encrypted_static,
+	     message->encrypted_timestamp))
+	  {
+	    peer = pool_elt_at_index (wmp->peers, rp->r_peer_idx);
+	  }
+
+	if (!peer)
+	  return WG_INPUT_ERROR_PEER;
+
+	// set_peer_address (peer, ip4_src, udp_src_port);
+	if (PREDICT_FALSE (!wg_send_handshake_response (vm, peer)))
+	  {
+	    vlib_node_increment_counter (vm, wg_input_node.index,
+					 WG_INPUT_ERROR_HANDSHAKE_SEND, 1);
+	  }
+	break;
+      }
+    case MESSAGE_HANDSHAKE_RESPONSE:
+      {
+	message_handshake_response_t *resp = current_b_data;
+	u32 *entry =
+	  wg_index_table_lookup (&wmp->index_table, resp->receiver_index);
+	if (entry)
+	  {
+	    peer = pool_elt_at_index (wmp->peers, *entry);
+	    if (!peer || peer->is_dead)
+	      return WG_INPUT_ERROR_PEER;
+	  }
+
+	if (!noise_consume_response
+	    (wmp->vlib_main, &peer->remote, resp->sender_index,
+	     resp->receiver_index, resp->unencrypted_ephemeral,
+	     resp->encrypted_nothing))
+	  {
+	    return WG_INPUT_ERROR_PEER;
+	  }
+	if (packet_needs_cookie)
+	  {
+	    // TODO: Add processing
+	  }
+
+	// set_peer_address (peer, ip4_src, udp_src_port);
+	if (noise_remote_begin_session (wmp->vlib_main, &peer->remote))
+	  {
+	    wg_timers_session_derived (peer);
+	    wg_timers_handshake_complete (peer);
+	    if (PREDICT_FALSE (!wg_send_keepalive (vm, peer)))
+	      {
+		vlib_node_increment_counter (vm, wg_input_node.index,
+					     WG_INPUT_ERROR_KEEPALIVE_SEND,
+					     1);
+	      }
+	  }
+	break;
+      }
+    default:
+      break;
+    }
+
+  wg_timers_any_authenticated_packet_received (peer);
+  wg_timers_any_authenticated_packet_traversal (peer);
+  return WG_INPUT_ERROR_NONE;
+}
+
+static_always_inline bool
+fib_prefix_is_cover_addr_4 (const fib_prefix_t * p1,
+			    const ip4_address_t * ip4)
+{
+  switch (p1->fp_proto)
+    {
+    case FIB_PROTOCOL_IP4:
+      return (ip4_destination_matches_route (&ip4_main,
+					     &p1->fp_addr.ip4,
+					     ip4, p1->fp_len) != 0);
+    case FIB_PROTOCOL_IP6:
+      return (false);
+    case FIB_PROTOCOL_MPLS:
+      break;
+    }
+  return (false);
+}
+
+VLIB_NODE_FN (wg_input_node) (vlib_main_t * vm,
+			      vlib_node_runtime_t * node,
+			      vlib_frame_t * frame)
+{
+  message_type_t header_type;
+  u32 n_left_from;
+  u32 *from;
+  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
+  u16 nexts[VLIB_FRAME_SIZE], *next;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  b = bufs;
+  next = nexts;
+
+  vlib_get_buffers (vm, from, bufs, n_left_from);
+
+  wg_main_t *wmp = &wg_main;
+  wg_peer_t *peer = NULL;
+
+  while (n_left_from > 0)
+    {
+      bool is_keepalive = false;
+      next[0] = WG_INPUT_NEXT_PUNT;
+      header_type =
+	((message_header_t *) vlib_buffer_get_current (b[0]))->type;
+
+      switch (header_type)
+	{
+	case MESSAGE_HANDSHAKE_INITIATION:
+	case MESSAGE_HANDSHAKE_RESPONSE:
+	case MESSAGE_HANDSHAKE_COOKIE:
+	  {
+	    wg_input_error_t ret = wg_handshake_process (vm, wmp, b[0]);
+	    if (ret != WG_INPUT_ERROR_NONE)
+	      {
+		next[0] = WG_INPUT_NEXT_ERROR;
+		b[0]->error = node->errors[ret];
+	      }
+	    break;
+	  }
+	case MESSAGE_DATA:
+	  {
+	    message_data_t *data = vlib_buffer_get_current (b[0]);
+	    u32 *entry =
+	      wg_index_table_lookup (&wmp->index_table, data->receiver_index);
+
+	    if (entry)
+	      {
+		peer = pool_elt_at_index (wmp->peers, *entry);
+		if (!peer)
+		  {
+		    next[0] = WG_INPUT_NEXT_ERROR;
+		    b[0]->error = node->errors[WG_INPUT_ERROR_PEER];
+		    goto out;
+		  }
+	      }
+
+	    u16 encr_len = b[0]->current_length - sizeof (message_data_t);
+	    u16 decr_len = encr_len - NOISE_AUTHTAG_LEN;
+	    u8 *decr_data = clib_mem_alloc (decr_len);
+
+	    enum noise_state_crypt state_cr =
+	      noise_remote_decrypt (wmp->vlib_main,
+				    &peer->remote,
+				    data->receiver_index,
+				    data->counter,
+				    data->encrypted_data,
+				    encr_len,
+				    decr_data);
+
+	    switch (state_cr)
+	      {
+	      case SC_OK:
+		break;
+	      case SC_CONN_RESET:
+		wg_timers_handshake_complete (peer);
+		break;
+	      case SC_KEEP_KEY_FRESH:
+		if (PREDICT_FALSE (!wg_send_handshake (vm, peer, false)))
+		  {
+		    vlib_node_increment_counter (vm, wg_input_node.index,
+						 WG_INPUT_ERROR_HANDSHAKE_SEND,
+						 1);
+		  }
+		break;
+	      case SC_FAILED:
+		next[0] = WG_INPUT_NEXT_ERROR;
+		b[0]->error = node->errors[WG_INPUT_ERROR_DECRYPTION];
+		goto out;
+	      default:
+		break;
+	      }
+
+	    clib_memcpy (vlib_buffer_get_current (b[0]), decr_data, decr_len);
+	    b[0]->current_length = decr_len;
+	    b[0]->flags &= ~VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
+
+	    clib_mem_free (decr_data);
+
+	    wg_timers_any_authenticated_packet_received (peer);
+	    wg_timers_any_authenticated_packet_traversal (peer);
+
+	    if (decr_len == 0)
+	      {
+		is_keepalive = true;
+		goto out;
+	      }
+
+	    wg_timers_data_received (peer);
+
+	    ip4_header_t *iph = vlib_buffer_get_current (b[0]);
+
+	    const wg_peer_allowed_ip_t *allowed_ip;
+	    bool allowed = false;
+
+	    /*
+	     * we could make this into an ACL, but the expectation
+	     * is that there aren't many allowed IPs and thus a linear
+	     * walk is fater than an ACL
+	     */
+	    vec_foreach (allowed_ip, peer->allowed_ips)
+	    {
+	      if (fib_prefix_is_cover_addr_4 (&allowed_ip->prefix,
+					      &iph->src_address))
+		{
+		  allowed = true;
+		  break;
+		}
+	    }
+	    if (allowed)
+	      {
+		vnet_buffer (b[0])->sw_if_index[VLIB_RX] =
+		  peer->wg_sw_if_index;
+		next[0] = WG_INPUT_NEXT_IP4_INPUT;
+	      }
+	    break;
+	  }
+	default:
+	  break;
+	}
+
+    out:
+      if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
+			 && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
+	{
+	  wg_input_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t));
+	  t->type = header_type;
+	  t->current_length = b[0]->current_length;
+	  t->is_keepalive = is_keepalive;
+	}
+      n_left_from -= 1;
+      next += 1;
+      b += 1;
+    }
+  vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
+
+  return frame->n_vectors;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (wg_input_node) =
+{
+  .name = "wg-input",
+  .vector_size = sizeof (u32),
+  .format_trace = format_wg_input_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (wg_input_error_strings),
+  .error_strings = wg_input_error_strings,
+  .n_next_nodes = WG_INPUT_N_NEXT,
+  /* edit / add dispositions here */
+  .next_nodes = {
+        [WG_INPUT_NEXT_IP4_INPUT] = "ip4-input-no-checksum",
+        [WG_INPUT_NEXT_PUNT] = "error-punt",
+        [WG_INPUT_NEXT_ERROR] = "error-drop",
+  },
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */