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-rwxr-xr-xsrc/plugins/wireguard/wireguard_input.c451
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:
+ */