diff options
Diffstat (limited to 'src/plugins/wireguard/wireguard_input.c')
| -rwxr-xr-x | src/plugins/wireguard/wireguard_input.c | 451 |
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: + */ |