1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 Copyright © 2015-2017 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
9 #include "sd-resolve.h"
11 #include "alloc-util.h"
12 #include "event-util.h"
15 #include "hexdecoct.h"
16 #include "memory-util.h"
17 #include "netlink-util.h"
18 #include "networkd-manager.h"
19 #include "networkd-util.h"
20 #include "parse-util.h"
21 #include "path-util.h"
22 #include "resolve-private.h"
23 #include "string-util.h"
25 #include "wireguard.h"
27 static void resolve_endpoints(NetDev
*netdev
);
29 static void wireguard_peer_free(WireguardPeer
*peer
) {
30 WireguardIPmask
*mask
;
35 if (peer
->wireguard
) {
36 LIST_REMOVE(peers
, peer
->wireguard
->peers
, peer
);
38 set_remove(peer
->wireguard
->peers_with_unresolved_endpoint
, peer
);
39 set_remove(peer
->wireguard
->peers_with_failed_endpoint
, peer
);
42 hashmap_remove(peer
->wireguard
->peers_by_section
, peer
->section
);
45 network_config_section_free(peer
->section
);
47 while ((mask
= peer
->ipmasks
)) {
48 LIST_REMOVE(ipmasks
, peer
->ipmasks
, mask
);
52 free(peer
->endpoint_host
);
53 free(peer
->endpoint_port
);
54 free(peer
->preshared_key_file
);
55 explicit_bzero_safe(peer
->preshared_key
, WG_KEY_LEN
);
60 DEFINE_NETWORK_SECTION_FUNCTIONS(WireguardPeer
, wireguard_peer_free
);
62 static int wireguard_peer_new_static(Wireguard
*w
, const char *filename
, unsigned section_line
, WireguardPeer
**ret
) {
63 _cleanup_(network_config_section_freep
) NetworkConfigSection
*n
= NULL
;
64 _cleanup_(wireguard_peer_freep
) WireguardPeer
*peer
= NULL
;
70 assert(section_line
> 0);
72 r
= network_config_section_new(filename
, section_line
, &n
);
76 peer
= hashmap_get(w
->peers_by_section
, n
);
78 *ret
= TAKE_PTR(peer
);
82 peer
= new(WireguardPeer
, 1);
86 *peer
= (WireguardPeer
) {
87 .flags
= WGPEER_F_REPLACE_ALLOWEDIPS
,
89 .section
= TAKE_PTR(n
),
92 LIST_PREPEND(peers
, w
->peers
, peer
);
94 r
= hashmap_ensure_allocated(&w
->peers_by_section
, &network_config_hash_ops
);
98 r
= hashmap_put(w
->peers_by_section
, peer
->section
, peer
);
102 *ret
= TAKE_PTR(peer
);
106 static int wireguard_set_ipmask_one(NetDev
*netdev
, sd_netlink_message
*message
, const WireguardIPmask
*mask
, uint16_t index
) {
113 /* This returns 1 on success, 0 on recoverable error, and negative errno on failure. */
115 r
= sd_netlink_message_open_array(message
, index
);
119 r
= sd_netlink_message_append_u16(message
, WGALLOWEDIP_A_FAMILY
, mask
->family
);
123 r
= netlink_message_append_in_addr_union(message
, WGALLOWEDIP_A_IPADDR
, mask
->family
, &mask
->ip
);
127 r
= sd_netlink_message_append_u8(message
, WGALLOWEDIP_A_CIDR_MASK
, mask
->cidr
);
131 r
= sd_netlink_message_close_container(message
);
133 return log_netdev_error_errno(netdev
, r
, "Could not add wireguard allowed ip: %m");
138 r
= sd_netlink_message_cancel_array(message
);
140 return log_netdev_error_errno(netdev
, r
, "Could not cancel wireguard allowed ip message attribute: %m");
145 static int wireguard_set_peer_one(NetDev
*netdev
, sd_netlink_message
*message
, const WireguardPeer
*peer
, uint16_t index
, WireguardIPmask
**mask_start
) {
146 WireguardIPmask
*mask
, *start
;
155 /* This returns 1 on success, 0 on recoverable error, and negative errno on failure. */
157 start
= *mask_start
?: peer
->ipmasks
;
159 r
= sd_netlink_message_open_array(message
, index
);
163 r
= sd_netlink_message_append_data(message
, WGPEER_A_PUBLIC_KEY
, &peer
->public_key
, sizeof(peer
->public_key
));
168 r
= sd_netlink_message_append_data(message
, WGPEER_A_PRESHARED_KEY
, &peer
->preshared_key
, WG_KEY_LEN
);
172 r
= sd_netlink_message_append_u32(message
, WGPEER_A_FLAGS
, peer
->flags
);
176 r
= sd_netlink_message_append_u16(message
, WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL
, peer
->persistent_keepalive_interval
);
180 if (IN_SET(peer
->endpoint
.sa
.sa_family
, AF_INET
, AF_INET6
)) {
181 r
= netlink_message_append_sockaddr_union(message
, WGPEER_A_ENDPOINT
, &peer
->endpoint
);
187 r
= sd_netlink_message_open_container(message
, WGPEER_A_ALLOWEDIPS
);
191 LIST_FOREACH(ipmasks
, mask
, start
) {
192 r
= wireguard_set_ipmask_one(netdev
, message
, mask
, ++j
);
199 r
= sd_netlink_message_close_container(message
);
201 return log_netdev_error_errno(netdev
, r
, "Could not add wireguard allowed ip: %m");
203 r
= sd_netlink_message_close_container(message
);
205 return log_netdev_error_errno(netdev
, r
, "Could not add wireguard peer: %m");
207 *mask_start
= mask
; /* Start next cycle from this mask. */
211 r
= sd_netlink_message_cancel_array(message
);
213 return log_netdev_error_errno(netdev
, r
, "Could not cancel wireguard peers: %m");
218 static int wireguard_set_interface(NetDev
*netdev
) {
219 _cleanup_(sd_netlink_message_unrefp
) sd_netlink_message
*message
= NULL
;
220 WireguardIPmask
*mask_start
= NULL
;
221 WireguardPeer
*peer
, *peer_start
;
222 bool sent_once
= false;
228 w
= WIREGUARD(netdev
);
231 for (peer_start
= w
->peers
; peer_start
|| !sent_once
; ) {
234 message
= sd_netlink_message_unref(message
);
236 r
= sd_genl_message_new(netdev
->manager
->genl
, SD_GENL_WIREGUARD
, WG_CMD_SET_DEVICE
, &message
);
238 return log_netdev_error_errno(netdev
, r
, "Failed to allocate generic netlink message: %m");
240 r
= sd_netlink_message_append_string(message
, WGDEVICE_A_IFNAME
, netdev
->ifname
);
242 return log_netdev_error_errno(netdev
, r
, "Could not append wireguard interface name: %m");
244 if (peer_start
== w
->peers
) {
245 r
= sd_netlink_message_append_data(message
, WGDEVICE_A_PRIVATE_KEY
, &w
->private_key
, WG_KEY_LEN
);
247 return log_netdev_error_errno(netdev
, r
, "Could not append wireguard private key: %m");
249 r
= sd_netlink_message_append_u16(message
, WGDEVICE_A_LISTEN_PORT
, w
->port
);
251 return log_netdev_error_errno(netdev
, r
, "Could not append wireguard port: %m");
253 r
= sd_netlink_message_append_u32(message
, WGDEVICE_A_FWMARK
, w
->fwmark
);
255 return log_netdev_error_errno(netdev
, r
, "Could not append wireguard fwmark: %m");
257 r
= sd_netlink_message_append_u32(message
, WGDEVICE_A_FLAGS
, w
->flags
);
259 return log_netdev_error_errno(netdev
, r
, "Could not append wireguard flags: %m");
262 r
= sd_netlink_message_open_container(message
, WGDEVICE_A_PEERS
);
264 return log_netdev_error_errno(netdev
, r
, "Could not append wireguard peer attributes: %m");
266 LIST_FOREACH(peers
, peer
, peer_start
) {
267 r
= wireguard_set_peer_one(netdev
, message
, peer
, ++i
, &mask_start
);
273 peer_start
= peer
; /* Start next cycle from this peer. */
275 r
= sd_netlink_message_close_container(message
);
277 return log_netdev_error_errno(netdev
, r
, "Could not close wireguard container: %m");
279 r
= sd_netlink_send(netdev
->manager
->genl
, message
, &serial
);
281 return log_netdev_error_errno(netdev
, r
, "Could not set wireguard device: %m");
289 static void wireguard_peer_destroy_callback(WireguardPeer
*peer
) {
293 assert(peer
->wireguard
);
295 netdev
= NETDEV(peer
->wireguard
);
297 if (section_is_invalid(peer
->section
))
298 wireguard_peer_free(peer
);
300 netdev_unref(netdev
);
303 static int on_resolve_retry(sd_event_source
*s
, usec_t usec
, void *userdata
) {
304 NetDev
*netdev
= userdata
;
308 w
= WIREGUARD(netdev
);
311 if (!netdev_is_managed(netdev
))
314 assert(set_isempty(w
->peers_with_unresolved_endpoint
));
316 SWAP_TWO(w
->peers_with_unresolved_endpoint
, w
->peers_with_failed_endpoint
);
318 resolve_endpoints(netdev
);
324 * Given the number of retries this function will return will an exponential
325 * increasing time in milliseconds to wait starting at 200ms and capped at 25 seconds.
327 static int exponential_backoff_milliseconds(unsigned n_retries
) {
328 return (2 << MIN(n_retries
, 7U)) * 100 * USEC_PER_MSEC
;
331 static int wireguard_resolve_handler(sd_resolve_query
*q
,
333 const struct addrinfo
*ai
,
334 WireguardPeer
*peer
) {
340 assert(peer
->wireguard
);
345 if (!netdev_is_managed(netdev
))
349 log_netdev_error(netdev
, "Failed to resolve host '%s:%s': %s", peer
->endpoint_host
, peer
->endpoint_port
, gai_strerror(ret
));
351 r
= set_ensure_put(&w
->peers_with_failed_endpoint
, NULL
, peer
);
353 log_netdev_error(netdev
, "Failed to save a peer, dropping the peer: %m");
354 peer
->section
->invalid
= true;
358 } else if ((ai
->ai_family
== AF_INET
&& ai
->ai_addrlen
== sizeof(struct sockaddr_in
)) ||
359 (ai
->ai_family
== AF_INET6
&& ai
->ai_addrlen
== sizeof(struct sockaddr_in6
)))
360 memcpy(&peer
->endpoint
, ai
->ai_addr
, ai
->ai_addrlen
);
362 log_netdev_error(netdev
, "Neither IPv4 nor IPv6 address found for peer endpoint %s:%s, ignoring the address.",
363 peer
->endpoint_host
, peer
->endpoint_port
);
366 if (!set_isempty(w
->peers_with_unresolved_endpoint
)) {
367 resolve_endpoints(netdev
);
371 (void) wireguard_set_interface(netdev
);
373 if (!set_isempty(w
->peers_with_failed_endpoint
)) {
377 usec
= usec_add(now(CLOCK_MONOTONIC
), exponential_backoff_milliseconds(w
->n_retries
));
378 r
= event_reset_time(netdev
->manager
->event
, &w
->resolve_retry_event_source
,
379 CLOCK_MONOTONIC
, usec
, 0, on_resolve_retry
, netdev
,
380 0, "wireguard-resolve-retry", true);
382 log_netdev_warning_errno(netdev
, r
, "Could not arm resolve retry handler: %m");
390 static void resolve_endpoints(NetDev
*netdev
) {
391 static const struct addrinfo hints
= {
392 .ai_family
= AF_UNSPEC
,
393 .ai_socktype
= SOCK_DGRAM
,
394 .ai_protocol
= IPPROTO_UDP
401 w
= WIREGUARD(netdev
);
404 SET_FOREACH(peer
, w
->peers_with_unresolved_endpoint
) {
405 r
= resolve_getaddrinfo(netdev
->manager
->resolve
,
410 wireguard_resolve_handler
,
411 wireguard_peer_destroy_callback
,
416 log_netdev_error_errno(netdev
, r
, "Failed to create resolver: %m");
420 /* Avoid freeing netdev. It will be unrefed by the destroy callback. */
423 (void) set_remove(w
->peers_with_unresolved_endpoint
, peer
);
427 static int netdev_wireguard_post_create(NetDev
*netdev
, Link
*link
, sd_netlink_message
*m
) {
429 assert(WIREGUARD(netdev
));
431 (void) wireguard_set_interface(netdev
);
432 resolve_endpoints(netdev
);
436 int config_parse_wireguard_listen_port(
438 const char *filename
,
441 unsigned section_line
,
454 if (isempty(rvalue
) || streq(rvalue
, "auto")) {
459 r
= parse_ip_port(rvalue
, s
);
461 log_syntax(unit
, LOG_WARNING
, filename
, line
, r
,
462 "Invalid port specification, ignoring assignment: %s", rvalue
);
469 static int wireguard_decode_key_and_warn(
471 uint8_t ret
[static WG_KEY_LEN
],
473 const char *filename
,
475 const char *lvalue
) {
477 _cleanup_(erase_and_freep
) void *key
= NULL
;
486 if (isempty(rvalue
)) {
487 memzero(ret
, WG_KEY_LEN
);
491 if (!streq(lvalue
, "PublicKey"))
492 (void) warn_file_is_world_accessible(filename
, NULL
, unit
, line
);
494 r
= unbase64mem_full(rvalue
, strlen(rvalue
), true, &key
, &len
);
496 return log_syntax(unit
, LOG_WARNING
, filename
, line
, r
,
497 "Failed to decode wireguard key provided by %s=, ignoring assignment: %m", lvalue
);
498 if (len
!= WG_KEY_LEN
)
499 return log_syntax(unit
, LOG_WARNING
, filename
, line
, SYNTHETIC_ERRNO(EINVAL
),
500 "Wireguard key provided by %s= has invalid length (%zu bytes), ignoring assignment.",
503 memcpy(ret
, key
, WG_KEY_LEN
);
507 int config_parse_wireguard_private_key(
509 const char *filename
,
512 unsigned section_line
,
525 (void) wireguard_decode_key_and_warn(rvalue
, w
->private_key
, unit
, filename
, line
, lvalue
);
529 int config_parse_wireguard_private_key_file(
531 const char *filename
,
534 unsigned section_line
,
541 _cleanup_free_
char *path
= NULL
;
548 if (isempty(rvalue
)) {
549 w
->private_key_file
= mfree(w
->private_key_file
);
553 path
= strdup(rvalue
);
557 if (path_simplify_and_warn(path
, PATH_CHECK_ABSOLUTE
, unit
, filename
, line
, lvalue
) < 0)
560 return free_and_replace(w
->private_key_file
, path
);
563 int config_parse_wireguard_preshared_key(
565 const char *filename
,
568 unsigned section_line
,
583 r
= wireguard_peer_new_static(w
, filename
, section_line
, &peer
);
587 (void) wireguard_decode_key_and_warn(rvalue
, peer
->preshared_key
, unit
, filename
, line
, lvalue
);
591 int config_parse_wireguard_preshared_key_file(
593 const char *filename
,
596 unsigned section_line
,
603 _cleanup_(wireguard_peer_free_or_set_invalidp
) WireguardPeer
*peer
= NULL
;
604 _cleanup_free_
char *path
= NULL
;
612 r
= wireguard_peer_new_static(w
, filename
, section_line
, &peer
);
616 if (isempty(rvalue
)) {
617 peer
->preshared_key_file
= mfree(peer
->preshared_key_file
);
622 path
= strdup(rvalue
);
626 if (path_simplify_and_warn(path
, PATH_CHECK_ABSOLUTE
, unit
, filename
, line
, lvalue
) < 0)
629 free_and_replace(peer
->preshared_key_file
, path
);
634 int config_parse_wireguard_public_key(
636 const char *filename
,
639 unsigned section_line
,
646 _cleanup_(wireguard_peer_free_or_set_invalidp
) WireguardPeer
*peer
= NULL
;
654 r
= wireguard_peer_new_static(w
, filename
, section_line
, &peer
);
658 r
= wireguard_decode_key_and_warn(rvalue
, peer
->public_key
, unit
, filename
, line
, lvalue
);
666 int config_parse_wireguard_allowed_ips(
668 const char *filename
,
671 unsigned section_line
,
678 _cleanup_(wireguard_peer_free_or_set_invalidp
) WireguardPeer
*peer
= NULL
;
679 union in_addr_union addr
;
680 unsigned char prefixlen
;
683 WireguardIPmask
*ipmask
;
691 r
= wireguard_peer_new_static(w
, filename
, section_line
, &peer
);
695 for (const char *p
= rvalue
;;) {
696 _cleanup_free_
char *word
= NULL
;
698 r
= extract_first_word(&p
, &word
, "," WHITESPACE
, 0);
704 log_syntax(unit
, LOG_WARNING
, filename
, line
, r
,
705 "Failed to split allowed ips \"%s\" option: %m", rvalue
);
709 r
= in_addr_prefix_from_string_auto(word
, &family
, &addr
, &prefixlen
);
711 log_syntax(unit
, LOG_WARNING
, filename
, line
, r
,
712 "Network address is invalid, ignoring assignment: %s", word
);
716 ipmask
= new(WireguardIPmask
, 1);
720 *ipmask
= (WireguardIPmask
) {
726 LIST_PREPEND(ipmasks
, peer
->ipmasks
, ipmask
);
733 int config_parse_wireguard_endpoint(
735 const char *filename
,
738 unsigned section_line
,
745 _cleanup_(wireguard_peer_free_or_set_invalidp
) WireguardPeer
*peer
= NULL
;
746 const char *begin
, *end
;
757 if (rvalue
[0] == '[') {
759 end
= strchr(rvalue
, ']');
761 log_syntax(unit
, LOG_WARNING
, filename
, line
, 0,
762 "Unable to find matching brace of endpoint, ignoring assignment: %s",
768 if (*end
!= ':' || !*(end
+ 1)) {
769 log_syntax(unit
, LOG_WARNING
, filename
, line
, 0,
770 "Unable to find port of endpoint, ignoring assignment: %s",
777 end
= strrchr(rvalue
, ':');
778 if (!end
|| !*(end
+ 1)) {
779 log_syntax(unit
, LOG_WARNING
, filename
, line
, 0,
780 "Unable to find port of endpoint, ignoring assignment: %s",
788 r
= wireguard_peer_new_static(w
, filename
, section_line
, &peer
);
792 r
= free_and_strndup(&peer
->endpoint_host
, begin
, len
);
796 r
= free_and_strdup(&peer
->endpoint_port
, end
);
800 r
= set_ensure_put(&w
->peers_with_unresolved_endpoint
, NULL
, peer
);
803 TAKE_PTR(peer
); /* The peer may already have been in the hash map, that is fine too. */
808 int config_parse_wireguard_keepalive(
810 const char *filename
,
813 unsigned section_line
,
821 uint16_t keepalive
= 0;
831 r
= wireguard_peer_new_static(w
, filename
, section_line
, &peer
);
835 if (streq(rvalue
, "off"))
838 r
= safe_atou16(rvalue
, &keepalive
);
840 log_syntax(unit
, LOG_WARNING
, filename
, line
, r
,
841 "Failed to parse \"%s\" as keepalive interval (range 0–65535), ignoring assignment: %m",
847 peer
->persistent_keepalive_interval
= keepalive
;
851 static void wireguard_init(NetDev
*netdev
) {
855 w
= WIREGUARD(netdev
);
858 w
->flags
= WGDEVICE_F_REPLACE_PEERS
;
861 static void wireguard_done(NetDev
*netdev
) {
865 w
= WIREGUARD(netdev
);
868 sd_event_source_unref(w
->resolve_retry_event_source
);
870 explicit_bzero_safe(w
->private_key
, WG_KEY_LEN
);
871 free(w
->private_key_file
);
873 hashmap_free_with_destructor(w
->peers_by_section
, wireguard_peer_free
);
874 set_free(w
->peers_with_unresolved_endpoint
);
875 set_free(w
->peers_with_failed_endpoint
);
878 static int wireguard_read_key_file(const char *filename
, uint8_t dest
[static WG_KEY_LEN
]) {
879 _cleanup_(erase_and_freep
) char *key
= NULL
;
888 (void) warn_file_is_world_accessible(filename
, NULL
, NULL
, 0);
890 r
= read_full_file_full(
892 READ_FULL_FILE_SECURE
| READ_FULL_FILE_UNBASE64
| READ_FULL_FILE_WARN_WORLD_READABLE
| READ_FULL_FILE_CONNECT_SOCKET
,
897 if (key_len
!= WG_KEY_LEN
)
900 memcpy(dest
, key
, WG_KEY_LEN
);
904 static int wireguard_peer_verify(WireguardPeer
*peer
) {
905 NetDev
*netdev
= NETDEV(peer
->wireguard
);
908 if (section_is_invalid(peer
->section
))
911 if (eqzero(peer
->public_key
))
912 return log_netdev_error_errno(netdev
, SYNTHETIC_ERRNO(EINVAL
),
913 "%s: WireGuardPeer section without PublicKey= configured. "
914 "Ignoring [WireGuardPeer] section from line %u.",
915 peer
->section
->filename
, peer
->section
->line
);
917 r
= wireguard_read_key_file(peer
->preshared_key_file
, peer
->preshared_key
);
919 return log_netdev_error_errno(netdev
, r
,
920 "%s: Failed to read preshared key from '%s'. "
921 "Ignoring [WireGuardPeer] section from line %u.",
922 peer
->section
->filename
, peer
->preshared_key_file
,
923 peer
->section
->line
);
928 static int wireguard_verify(NetDev
*netdev
, const char *filename
) {
929 WireguardPeer
*peer
, *peer_next
;
934 w
= WIREGUARD(netdev
);
937 r
= wireguard_read_key_file(w
->private_key_file
, w
->private_key
);
939 return log_netdev_error_errno(netdev
, r
,
940 "Failed to read private key from %s. Dropping network device %s.",
941 w
->private_key_file
, netdev
->ifname
);
943 if (eqzero(w
->private_key
))
944 return log_netdev_error_errno(netdev
, SYNTHETIC_ERRNO(EINVAL
),
945 "%s: Missing PrivateKey= or PrivateKeyFile=, "
946 "Dropping network device %s.",
947 filename
, netdev
->ifname
);
949 LIST_FOREACH_SAFE(peers
, peer
, peer_next
, w
->peers
)
950 if (wireguard_peer_verify(peer
) < 0)
951 wireguard_peer_free(peer
);
956 const NetDevVTable wireguard_vtable
= {
957 .object_size
= sizeof(Wireguard
),
958 .sections
= NETDEV_COMMON_SECTIONS
"WireGuard\0WireGuardPeer\0",
959 .post_create
= netdev_wireguard_post_create
,
960 .init
= wireguard_init
,
961 .done
= wireguard_done
,
962 .create_type
= NETDEV_CREATE_INDEPENDENT
,
963 .config_verify
= wireguard_verify
,
964 .generate_mac
= true,