src/network/netdev/wireguard.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 /***
   3   Copyright © 2015-2017 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
   4 ***/
   5
   6 #include <sys/ioctl.h>
   7 #include <net/if.h>
   8 #include <netinet/in.h>
   9 #include <linux/if_arp.h>
  10 #include <linux/ipv6_route.h>
  11
  12 #include "sd-resolve.h"
  13
  14 #include "alloc-util.h"
  15 #include "dns-domain.h"
  16 #include "event-util.h"
  17 #include "fd-util.h"
  18 #include "fileio.h"
  19 #include "hexdecoct.h"
  20 #include "memory-util.h"
  21 #include "netlink-util.h"
  22 #include "networkd-manager.h"
  23 #include "networkd-route-util.h"
  24 #include "networkd-route.h"
  25 #include "networkd-util.h"
  26 #include "parse-helpers.h"
  27 #include "parse-util.h"
  28 #include "random-util.h"
  29 #include "resolve-private.h"
  30 #include "string-util.h"
  31 #include "strv.h"
  32 #include "wireguard.h"
  33
  34 static void wireguard_resolve_endpoints(NetDev *netdev);
  35 static int peer_resolve_endpoint(WireguardPeer *peer);
  36
  37 static void wireguard_peer_clear_ipmasks(WireguardPeer *peer) {
  38         assert(peer);
  39
  40         LIST_CLEAR(ipmasks, peer->ipmasks, free);
  41 }
  42
  43 static WireguardPeer* wireguard_peer_free(WireguardPeer *peer) {
  44         if (!peer)
  45                 return NULL;
  46
  47         if (peer->wireguard) {
  48                 LIST_REMOVE(peers, peer->wireguard->peers, peer);
  49
  50                 if (peer->section)
  51                         hashmap_remove(peer->wireguard->peers_by_section, peer->section);
  52         }
  53
  54         config_section_free(peer->section);
  55
  56         wireguard_peer_clear_ipmasks(peer);
  57
  58         free(peer->endpoint_host);
  59         free(peer->endpoint_port);
  60         free(peer->preshared_key_file);
  61         explicit_bzero_safe(peer->preshared_key, WG_KEY_LEN);
  62
  63         sd_event_source_disable_unref(peer->resolve_retry_event_source);
  64         sd_resolve_query_unref(peer->resolve_query);
  65
  66         return mfree(peer);
  67 }
  68
  69 DEFINE_SECTION_CLEANUP_FUNCTIONS(WireguardPeer, wireguard_peer_free);
  70
  71 static int wireguard_peer_new_static(Wireguard *w, const char *filename, unsigned section_line, WireguardPeer **ret) {
  72         _cleanup_(config_section_freep) ConfigSection *n = NULL;
  73         _cleanup_(wireguard_peer_freep) WireguardPeer *peer = NULL;
  74         int r;
  75
  76         assert(w);
  77         assert(ret);
  78         assert(filename);
  79         assert(section_line > 0);
  80
  81         r = config_section_new(filename, section_line, &n);
  82         if (r < 0)
  83                 return r;
  84
  85         peer = hashmap_get(w->peers_by_section, n);
  86         if (peer) {
  87                 *ret = TAKE_PTR(peer);
  88                 return 0;
  89         }
  90
  91         peer = new(WireguardPeer, 1);
  92         if (!peer)
  93                 return -ENOMEM;
  94
  95         *peer = (WireguardPeer) {
  96                 .flags = WGPEER_F_REPLACE_ALLOWEDIPS,
  97                 .wireguard = w,
  98                 .section = TAKE_PTR(n),
  99         };
 100
 101         LIST_PREPEND(peers, w->peers, peer);
 102
 103         r = hashmap_ensure_put(&w->peers_by_section, &config_section_hash_ops, peer->section, peer);
 104         if (r < 0)
 105                 return r;
 106
 107         *ret = TAKE_PTR(peer);
 108         return 0;
 109 }
 110
 111 static int wireguard_set_ipmask_one(NetDev *netdev, sd_netlink_message *message, const WireguardIPmask *mask, uint16_t index) {
 112         int r;
 113
 114         assert(message);
 115         assert(mask);
 116         assert(index > 0);
 117
 118         /* This returns 1 on success, 0 on recoverable error, and negative errno on failure. */
 119
 120         r = sd_netlink_message_open_array(message, index);
 121         if (r < 0)
 122                 return 0;
 123
 124         r = sd_netlink_message_append_u16(message, WGALLOWEDIP_A_FAMILY, mask->family);
 125         if (r < 0)
 126                 goto cancel;
 127
 128         r = netlink_message_append_in_addr_union(message, WGALLOWEDIP_A_IPADDR, mask->family, &mask->ip);
 129         if (r < 0)
 130                 goto cancel;
 131
 132         r = sd_netlink_message_append_u8(message, WGALLOWEDIP_A_CIDR_MASK, mask->cidr);
 133         if (r < 0)
 134                 goto cancel;
 135
 136         r = sd_netlink_message_close_container(message);
 137         if (r < 0)
 138                 return log_netdev_error_errno(netdev, r, "Could not add wireguard allowed ip: %m");
 139
 140         return 1;
 141
 142 cancel:
 143         r = sd_netlink_message_cancel_array(message);
 144         if (r < 0)
 145                 return log_netdev_error_errno(netdev, r, "Could not cancel wireguard allowed ip message attribute: %m");
 146
 147         return 0;
 148 }
 149
 150 static int wireguard_set_peer_one(NetDev *netdev, sd_netlink_message *message, const WireguardPeer *peer, uint16_t index, WireguardIPmask **mask_start) {
 151         WireguardIPmask *start, *last = NULL;
 152         uint16_t j = 0;
 153         int r;
 154
 155         assert(message);
 156         assert(peer);
 157         assert(index > 0);
 158         assert(mask_start);
 159
 160         /* This returns 1 on success, 0 on recoverable error, and negative errno on failure. */
 161
 162         start = *mask_start ?: peer->ipmasks;
 163
 164         r = sd_netlink_message_open_array(message, index);
 165         if (r < 0)
 166                 return 0;
 167
 168         r = sd_netlink_message_append_data(message, WGPEER_A_PUBLIC_KEY, &peer->public_key, sizeof(peer->public_key));
 169         if (r < 0)
 170                 goto cancel;
 171
 172         if (!*mask_start) {
 173                 r = sd_netlink_message_append_data(message, WGPEER_A_PRESHARED_KEY, &peer->preshared_key, WG_KEY_LEN);
 174                 if (r < 0)
 175                         goto cancel;
 176
 177                 r = sd_netlink_message_append_u32(message, WGPEER_A_FLAGS, peer->flags);
 178                 if (r < 0)
 179                         goto cancel;
 180
 181                 r = sd_netlink_message_append_u16(message, WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL, peer->persistent_keepalive_interval);
 182                 if (r < 0)
 183                         goto cancel;
 184
 185                 if (IN_SET(peer->endpoint.sa.sa_family, AF_INET, AF_INET6)) {
 186                         r = netlink_message_append_sockaddr_union(message, WGPEER_A_ENDPOINT, &peer->endpoint);
 187                         if (r < 0)
 188                                 goto cancel;
 189                 }
 190         }
 191
 192         r = sd_netlink_message_open_container(message, WGPEER_A_ALLOWEDIPS);
 193         if (r < 0)
 194                 goto cancel;
 195
 196         LIST_FOREACH(ipmasks, mask, start) {
 197                 r = wireguard_set_ipmask_one(netdev, message, mask, ++j);
 198                 if (r < 0)
 199                         return r;
 200                 if (r == 0) {
 201                         last = mask;
 202                         break;
 203                 }
 204         }
 205
 206         r = sd_netlink_message_close_container(message);
 207         if (r < 0)
 208                 return log_netdev_error_errno(netdev, r, "Could not add wireguard allowed ip: %m");
 209
 210         r = sd_netlink_message_close_container(message);
 211         if (r < 0)
 212                 return log_netdev_error_errno(netdev, r, "Could not add wireguard peer: %m");
 213
 214         *mask_start = last; /* Start next cycle from this mask. */
 215         return !last;
 216
 217 cancel:
 218         r = sd_netlink_message_cancel_array(message);
 219         if (r < 0)
 220                 return log_netdev_error_errno(netdev, r, "Could not cancel wireguard peers: %m");
 221
 222         return 0;
 223 }
 224
 225 static int wireguard_set_interface(NetDev *netdev) {
 226         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL;
 227         WireguardIPmask *mask_start = NULL;
 228         WireguardPeer *peer_start;
 229         bool sent_once = false;
 230         uint32_t serial;
 231         Wireguard *w = WIREGUARD(netdev);
 232         int r;
 233
 234         for (peer_start = w->peers; peer_start || !sent_once; ) {
 235                 uint16_t i = 0;
 236
 237                 message = sd_netlink_message_unref(message);
 238
 239                 r = sd_genl_message_new(netdev->manager->genl, WG_GENL_NAME, WG_CMD_SET_DEVICE, &message);
 240                 if (r < 0)
 241                         return log_netdev_error_errno(netdev, r, "Failed to allocate generic netlink message: %m");
 242
 243                 r = sd_netlink_message_append_string(message, WGDEVICE_A_IFNAME, netdev->ifname);
 244                 if (r < 0)
 245                         return log_netdev_error_errno(netdev, r, "Could not append wireguard interface name: %m");
 246
 247                 if (peer_start == w->peers) {
 248                         r = sd_netlink_message_append_data(message, WGDEVICE_A_PRIVATE_KEY, &w->private_key, WG_KEY_LEN);
 249                         if (r < 0)
 250                                 return log_netdev_error_errno(netdev, r, "Could not append wireguard private key: %m");
 251
 252                         r = sd_netlink_message_append_u16(message, WGDEVICE_A_LISTEN_PORT, w->port);
 253                         if (r < 0)
 254                                 return log_netdev_error_errno(netdev, r, "Could not append wireguard port: %m");
 255
 256                         r = sd_netlink_message_append_u32(message, WGDEVICE_A_FWMARK, w->fwmark);
 257                         if (r < 0)
 258                                 return log_netdev_error_errno(netdev, r, "Could not append wireguard fwmark: %m");
 259
 260                         r = sd_netlink_message_append_u32(message, WGDEVICE_A_FLAGS, w->flags);
 261                         if (r < 0)
 262                                 return log_netdev_error_errno(netdev, r, "Could not append wireguard flags: %m");
 263                 }
 264
 265                 r = sd_netlink_message_open_container(message, WGDEVICE_A_PEERS);
 266                 if (r < 0)
 267                         return log_netdev_error_errno(netdev, r, "Could not append wireguard peer attributes: %m");
 268
 269                 WireguardPeer *peer_last = NULL;
 270                 LIST_FOREACH(peers, peer, peer_start) {
 271                         r = wireguard_set_peer_one(netdev, message, peer, ++i, &mask_start);
 272                         if (r < 0)
 273                                 return r;
 274                         if (r == 0) {
 275                                 peer_last = peer;
 276                                 break;
 277                         }
 278                 }
 279                 peer_start = peer_last; /* Start next cycle from this peer. */
 280
 281                 r = sd_netlink_message_close_container(message);
 282                 if (r < 0)
 283                         return log_netdev_error_errno(netdev, r, "Could not close wireguard container: %m");
 284
 285                 r = sd_netlink_send(netdev->manager->genl, message, &serial);
 286                 if (r < 0)
 287                         return log_netdev_error_errno(netdev, r, "Could not set wireguard device: %m");
 288
 289                 sent_once = true;
 290         }
 291
 292         return 0;
 293 }
 294
 295 static int on_resolve_retry(sd_event_source *s, usec_t usec, void *userdata) {
 296         WireguardPeer *peer = ASSERT_PTR(userdata);
 297         NetDev *netdev;
 298
 299         assert(peer->wireguard);
 300
 301         netdev = NETDEV(peer->wireguard);
 302
 303         if (!netdev_is_managed(netdev))
 304                 return 0;
 305
 306         peer->resolve_query = sd_resolve_query_unref(peer->resolve_query);
 307
 308         (void) peer_resolve_endpoint(peer);
 309         return 0;
 310 }
 311
 312 static usec_t peer_next_resolve_usec(WireguardPeer *peer) {
 313         usec_t usec;
 314
 315         /* Given the number of retries this function will return an exponential increasing amount of
 316          * milliseconds to wait starting at 200ms and capped at 25 seconds. */
 317
 318         assert(peer);
 319
 320         usec = (2 << MIN(peer->n_retries, 7U)) * 100 * USEC_PER_MSEC;
 321
 322         return random_u64_range(usec / 10) + usec * 9 / 10;
 323 }
 324
 325 static int wireguard_peer_resolve_handler(
 326               sd_resolve_query *q,
 327               int ret,
 328               const struct addrinfo *ai,
 329               void *userdata) {
 330
 331         WireguardPeer *peer = ASSERT_PTR(userdata);
 332         NetDev *netdev;
 333         int r;
 334
 335         assert(peer->wireguard);
 336
 337         netdev = NETDEV(peer->wireguard);
 338
 339         if (!netdev_is_managed(netdev))
 340                 return 0;
 341
 342         if (ret != 0) {
 343                 log_netdev_warning(netdev, "Failed to resolve host '%s:%s', ignoring: %s",
 344                                    peer->endpoint_host, peer->endpoint_port, gai_strerror(ret));
 345                 peer->n_retries++;
 346
 347         } else {
 348                 bool found = false;
 349                 for (; ai; ai = ai->ai_next) {
 350                         if (!IN_SET(ai->ai_family, AF_INET, AF_INET6))
 351                                 continue;
 352
 353                         if (ai->ai_addrlen != (ai->ai_family == AF_INET ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6)))
 354                                 continue;
 355
 356                         memcpy(&peer->endpoint, ai->ai_addr, ai->ai_addrlen);
 357                         (void) wireguard_set_interface(netdev);
 358                         peer->n_retries = 0;
 359                         found = true;
 360                         break;
 361                 }
 362
 363                 if (!found) {
 364                         log_netdev_warning(netdev, "Neither IPv4 nor IPv6 address found for peer endpoint %s:%s, ignoring the endpoint.",
 365                                            peer->endpoint_host, peer->endpoint_port);
 366                         peer->n_retries++;
 367                 }
 368         }
 369
 370         if (peer->n_retries > 0) {
 371                 r = event_reset_time_relative(netdev->manager->event,
 372                                               &peer->resolve_retry_event_source,
 373                                               CLOCK_BOOTTIME,
 374                                               peer_next_resolve_usec(peer), 0,
 375                                               on_resolve_retry, peer, 0, "wireguard-resolve-retry", true);
 376                 if (r < 0)
 377                         log_netdev_warning_errno(netdev, r, "Could not arm resolve retry handler for endpoint %s:%s, ignoring: %m",
 378                                                  peer->endpoint_host, peer->endpoint_port);
 379         }
 380
 381         wireguard_resolve_endpoints(netdev);
 382         return 0;
 383 }
 384
 385 static int peer_resolve_endpoint(WireguardPeer *peer) {
 386         static const struct addrinfo hints = {
 387                 .ai_family = AF_UNSPEC,
 388                 .ai_socktype = SOCK_DGRAM,
 389                 .ai_protocol = IPPROTO_UDP
 390         };
 391         NetDev *netdev;
 392         int r;
 393
 394         assert(peer);
 395         assert(peer->wireguard);
 396
 397         netdev = NETDEV(peer->wireguard);
 398
 399         if (!peer->endpoint_host || !peer->endpoint_port)
 400                 /* Not necessary to resolve the endpoint. */
 401                 return 0;
 402
 403         if (sd_event_source_get_enabled(peer->resolve_retry_event_source, NULL) > 0)
 404                 /* Timer event source is enabled. The endpoint will be resolved later. */
 405                 return 0;
 406
 407         if (peer->resolve_query)
 408                 /* Being resolved, or already resolved. */
 409                 return 0;
 410
 411         r = sd_resolve_getaddrinfo(netdev->manager->resolve,
 412                                    &peer->resolve_query,
 413                                    peer->endpoint_host,
 414                                    peer->endpoint_port,
 415                                    &hints,
 416                                    wireguard_peer_resolve_handler,
 417                                    peer);
 418         if (r < 0)
 419                 return log_netdev_full_errno(netdev, r == -ENOBUFS ? LOG_DEBUG : LOG_WARNING, r,
 420                                              "Failed to create endpoint resolver for %s:%s, ignoring: %m",
 421                                              peer->endpoint_host, peer->endpoint_port);
 422
 423         return 0;
 424 }
 425
 426 static void wireguard_resolve_endpoints(NetDev *netdev) {
 427         Wireguard *w = WIREGUARD(netdev);
 428
 429         LIST_FOREACH(peers, peer, w->peers)
 430                 if (peer_resolve_endpoint(peer) == -ENOBUFS)
 431                         /* Too many requests. Let's resolve remaining endpoints later. */
 432                         break;
 433 }
 434
 435 static int netdev_wireguard_post_create(NetDev *netdev, Link *link) {
 436         assert(WIREGUARD(netdev));
 437
 438         (void) wireguard_set_interface(netdev);
 439         wireguard_resolve_endpoints(netdev);
 440         return 0;
 441 }
 442
 443 int config_parse_wireguard_listen_port(
 444                 const char *unit,
 445                 const char *filename,
 446                 unsigned line,
 447                 const char *section,
 448                 unsigned section_line,
 449                 const char *lvalue,
 450                 int ltype,
 451                 const char *rvalue,
 452                 void *data,
 453                 void *userdata) {
 454
 455         uint16_t *s = ASSERT_PTR(data);
 456         int r;
 457
 458         assert(rvalue);
 459
 460         if (isempty(rvalue) || streq(rvalue, "auto")) {
 461                 *s = 0;
 462                 return 0;
 463         }
 464
 465         r = parse_ip_port(rvalue, s);
 466         if (r < 0) {
 467                 log_syntax(unit, LOG_WARNING, filename, line, r,
 468                            "Invalid port specification, ignoring assignment: %s", rvalue);
 469                 return 0;
 470         }
 471
 472         return 0;
 473 }
 474
 475 static int wireguard_decode_key_and_warn(
 476                 const char *rvalue,
 477                 uint8_t ret[static WG_KEY_LEN],
 478                 const char *unit,
 479                 const char *filename,
 480                 unsigned line,
 481                 const char *lvalue) {
 482
 483         _cleanup_(erase_and_freep) void *key = NULL;
 484         size_t len;
 485         int r;
 486
 487         assert(rvalue);
 488         assert(ret);
 489         assert(filename);
 490         assert(lvalue);
 491
 492         if (isempty(rvalue)) {
 493                 memzero(ret, WG_KEY_LEN);
 494                 return 0;
 495         }
 496
 497         if (!streq(lvalue, "PublicKey"))
 498                 (void) warn_file_is_world_accessible(filename, NULL, unit, line);
 499
 500         r = unbase64mem_full(rvalue, strlen(rvalue), true, &key, &len);
 501         if (r == -ENOMEM)
 502                 return log_oom();
 503         if (r < 0) {
 504                 log_syntax(unit, LOG_WARNING, filename, line, r,
 505                            "Failed to decode wireguard key provided by %s=, ignoring assignment: %m", lvalue);
 506                 return 0;
 507         }
 508         if (len != WG_KEY_LEN) {
 509                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 510                            "Wireguard key provided by %s= has invalid length (%zu bytes), ignoring assignment.",
 511                            lvalue, len);
 512                 return 0;
 513         }
 514
 515         memcpy(ret, key, WG_KEY_LEN);
 516         return 0;
 517 }
 518
 519 int config_parse_wireguard_private_key(
 520                 const char *unit,
 521                 const char *filename,
 522                 unsigned line,
 523                 const char *section,
 524                 unsigned section_line,
 525                 const char *lvalue,
 526                 int ltype,
 527                 const char *rvalue,
 528                 void *data,
 529                 void *userdata) {
 530
 531         Wireguard *w = WIREGUARD(data);
 532
 533         return wireguard_decode_key_and_warn(rvalue, w->private_key, unit, filename, line, lvalue);
 534 }
 535
 536 int config_parse_wireguard_private_key_file(
 537                 const char *unit,
 538                 const char *filename,
 539                 unsigned line,
 540                 const char *section,
 541                 unsigned section_line,
 542                 const char *lvalue,
 543                 int ltype,
 544                 const char *rvalue,
 545                 void *data,
 546                 void *userdata) {
 547
 548         Wireguard *w = WIREGUARD(data);
 549         _cleanup_free_ char *path = NULL;
 550
 551         if (isempty(rvalue)) {
 552                 w->private_key_file = mfree(w->private_key_file);
 553                 return 0;
 554         }
 555
 556         path = strdup(rvalue);
 557         if (!path)
 558                 return log_oom();
 559
 560         if (path_simplify_and_warn(path, PATH_CHECK_ABSOLUTE, unit, filename, line, lvalue) < 0)
 561                 return 0;
 562
 563         return free_and_replace(w->private_key_file, path);
 564 }
 565
 566 int config_parse_wireguard_peer_key(
 567                 const char *unit,
 568                 const char *filename,
 569                 unsigned line,
 570                 const char *section,
 571                 unsigned section_line,
 572                 const char *lvalue,
 573                 int ltype,
 574                 const char *rvalue,
 575                 void *data,
 576                 void *userdata) {
 577
 578         Wireguard *w = WIREGUARD(data);
 579         _cleanup_(wireguard_peer_free_or_set_invalidp) WireguardPeer *peer = NULL;
 580         int r;
 581
 582         r = wireguard_peer_new_static(w, filename, section_line, &peer);
 583         if (r < 0)
 584                 return log_oom();
 585
 586         r = wireguard_decode_key_and_warn(rvalue,
 587                                           streq(lvalue, "PublicKey") ? peer->public_key : peer->preshared_key,
 588                                           unit, filename, line, lvalue);
 589         if (r < 0)
 590                 return r;
 591
 592         TAKE_PTR(peer);
 593         return 0;
 594 }
 595
 596 int config_parse_wireguard_preshared_key_file(
 597                 const char *unit,
 598                 const char *filename,
 599                 unsigned line,
 600                 const char *section,
 601                 unsigned section_line,
 602                 const char *lvalue,
 603                 int ltype,
 604                 const char *rvalue,
 605                 void *data,
 606                 void *userdata) {
 607
 608         Wireguard *w = WIREGUARD(data);
 609         _cleanup_(wireguard_peer_free_or_set_invalidp) WireguardPeer *peer = NULL;
 610         _cleanup_free_ char *path = NULL;
 611         int r;
 612
 613         r = wireguard_peer_new_static(w, filename, section_line, &peer);
 614         if (r < 0)
 615                 return log_oom();
 616
 617         if (isempty(rvalue)) {
 618                 peer->preshared_key_file = mfree(peer->preshared_key_file);
 619                 TAKE_PTR(peer);
 620                 return 0;
 621         }
 622
 623         path = strdup(rvalue);
 624         if (!path)
 625                 return log_oom();
 626
 627         if (path_simplify_and_warn(path, PATH_CHECK_ABSOLUTE, unit, filename, line, lvalue) < 0)
 628                 return 0;
 629
 630         free_and_replace(peer->preshared_key_file, path);
 631         TAKE_PTR(peer);
 632         return 0;
 633 }
 634
 635 int config_parse_wireguard_allowed_ips(
 636                 const char *unit,
 637                 const char *filename,
 638                 unsigned line,
 639                 const char *section,
 640                 unsigned section_line,
 641                 const char *lvalue,
 642                 int ltype,
 643                 const char *rvalue,
 644                 void *data,
 645                 void *userdata) {
 646
 647         assert(rvalue);
 648
 649         Wireguard *w = WIREGUARD(data);
 650         _cleanup_(wireguard_peer_free_or_set_invalidp) WireguardPeer *peer = NULL;
 651         union in_addr_union addr;
 652         unsigned char prefixlen;
 653         int r, family;
 654         WireguardIPmask *ipmask;
 655
 656         r = wireguard_peer_new_static(w, filename, section_line, &peer);
 657         if (r < 0)
 658                 return log_oom();
 659
 660         if (isempty(rvalue)) {
 661                 wireguard_peer_clear_ipmasks(peer);
 662                 TAKE_PTR(peer);
 663                 return 0;
 664         }
 665
 666         for (const char *p = rvalue;;) {
 667                 _cleanup_free_ char *word = NULL;
 668                 union in_addr_union masked;
 669
 670                 r = extract_first_word(&p, &word, "," WHITESPACE, 0);
 671                 if (r == 0)
 672                         break;
 673                 if (r == -ENOMEM)
 674                         return log_oom();
 675                 if (r < 0) {
 676                         log_syntax(unit, LOG_WARNING, filename, line, r,
 677                                    "Failed to split allowed ips \"%s\" option: %m", rvalue);
 678                         break;
 679                 }
 680
 681                 r = in_addr_prefix_from_string_auto(word, &family, &addr, &prefixlen);
 682                 if (r < 0) {
 683                         log_syntax(unit, LOG_WARNING, filename, line, r,
 684                                    "Network address is invalid, ignoring assignment: %s", word);
 685                         continue;
 686                 }
 687
 688                 masked = addr;
 689                 assert_se(in_addr_mask(family, &masked, prefixlen) >= 0);
 690                 if (!in_addr_equal(family, &masked, &addr))
 691                         log_syntax(unit, LOG_WARNING, filename, line, 0,
 692                                    "Specified address '%s' is not properly masked, assuming '%s'.",
 693                                    word,
 694                                    IN_ADDR_PREFIX_TO_STRING(family, &masked, prefixlen));
 695
 696                 ipmask = new(WireguardIPmask, 1);
 697                 if (!ipmask)
 698                         return log_oom();
 699
 700                 *ipmask = (WireguardIPmask) {
 701                         .family = family,
 702                         .ip = masked,
 703                         .cidr = prefixlen,
 704                 };
 705
 706                 LIST_PREPEND(ipmasks, peer->ipmasks, ipmask);
 707         }
 708
 709         TAKE_PTR(peer);
 710         return 0;
 711 }
 712
 713 int config_parse_wireguard_endpoint(
 714                 const char *unit,
 715                 const char *filename,
 716                 unsigned line,
 717                 const char *section,
 718                 unsigned section_line,
 719                 const char *lvalue,
 720                 int ltype,
 721                 const char *rvalue,
 722                 void *data,
 723                 void *userdata) {
 724
 725         assert(filename);
 726         assert(rvalue);
 727         assert(userdata);
 728
 729         Wireguard *w = WIREGUARD(userdata);
 730         _cleanup_(wireguard_peer_free_or_set_invalidp) WireguardPeer *peer = NULL;
 731         _cleanup_free_ char *host = NULL;
 732         union in_addr_union addr;
 733         const char *p;
 734         uint16_t port;
 735         int family, r;
 736
 737         r = wireguard_peer_new_static(w, filename, section_line, &peer);
 738         if (r < 0)
 739                 return log_oom();
 740
 741         r = in_addr_port_ifindex_name_from_string_auto(rvalue, &family, &addr, &port, NULL, NULL);
 742         if (r >= 0) {
 743                 if (family == AF_INET)
 744                         peer->endpoint.in = (struct sockaddr_in) {
 745                                 .sin_family = AF_INET,
 746                                 .sin_addr = addr.in,
 747                                 .sin_port = htobe16(port),
 748                         };
 749                 else if (family == AF_INET6)
 750                         peer->endpoint.in6 = (struct sockaddr_in6) {
 751                                 .sin6_family = AF_INET6,
 752                                 .sin6_addr = addr.in6,
 753                                 .sin6_port = htobe16(port),
 754                         };
 755                 else
 756                         assert_not_reached();
 757
 758                 peer->endpoint_host = mfree(peer->endpoint_host);
 759                 peer->endpoint_port = mfree(peer->endpoint_port);
 760
 761                 TAKE_PTR(peer);
 762                 return 0;
 763         }
 764
 765         p = strrchr(rvalue, ':');
 766         if (!p) {
 767                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 768                            "Unable to find port of endpoint, ignoring assignment: %s",
 769                            rvalue);
 770                 return 0;
 771         }
 772
 773         host = strndup(rvalue, p - rvalue);
 774         if (!host)
 775                 return log_oom();
 776
 777         if (!dns_name_is_valid(host)) {
 778                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 779                            "Invalid domain name of endpoint, ignoring assignment: %s",
 780                            rvalue);
 781                 return 0;
 782         }
 783
 784         p++;
 785         r = parse_ip_port(p, &port);
 786         if (r < 0) {
 787                 log_syntax(unit, LOG_WARNING, filename, line, r,
 788                            "Invalid port of endpoint, ignoring assignment: %s",
 789                            rvalue);
 790                 return 0;
 791         }
 792
 793         peer->endpoint = (union sockaddr_union) {};
 794
 795         free_and_replace(peer->endpoint_host, host);
 796
 797         r = free_and_strdup(&peer->endpoint_port, p);
 798         if (r < 0)
 799                 return log_oom();
 800
 801         TAKE_PTR(peer); /* The peer may already have been in the hash map, that is fine too. */
 802         return 0;
 803 }
 804
 805 int config_parse_wireguard_keepalive(
 806                 const char *unit,
 807                 const char *filename,
 808                 unsigned line,
 809                 const char *section,
 810                 unsigned section_line,
 811                 const char *lvalue,
 812                 int ltype,
 813                 const char *rvalue,
 814                 void *data,
 815                 void *userdata) {
 816
 817         assert(rvalue);
 818
 819         Wireguard *w = WIREGUARD(data);
 820         _cleanup_(wireguard_peer_free_or_set_invalidp) WireguardPeer *peer = NULL;
 821         uint16_t keepalive = 0;
 822         int r;
 823
 824         r = wireguard_peer_new_static(w, filename, section_line, &peer);
 825         if (r < 0)
 826                 return log_oom();
 827
 828         if (streq(rvalue, "off"))
 829                 keepalive = 0;
 830         else {
 831                 r = safe_atou16(rvalue, &keepalive);
 832                 if (r < 0) {
 833                         log_syntax(unit, LOG_WARNING, filename, line, r,
 834                                    "Failed to parse \"%s\" as keepalive interval (range 0–65535), ignoring assignment: %m",
 835                                    rvalue);
 836                         return 0;
 837                 }
 838         }
 839
 840         peer->persistent_keepalive_interval = keepalive;
 841
 842         TAKE_PTR(peer);
 843         return 0;
 844 }
 845
 846 int config_parse_wireguard_route_table(
 847                 const char *unit,
 848                 const char *filename,
 849                 unsigned line,
 850                 const char *section,
 851                 unsigned section_line,
 852                 const char *lvalue,
 853                 int ltype,
 854                 const char *rvalue,
 855                 void *data,
 856                 void *userdata) {
 857
 858         NetDev *netdev = ASSERT_PTR(userdata);
 859         uint32_t *table = ASSERT_PTR(data);
 860         int r;
 861
 862         assert(filename);
 863         assert(lvalue);
 864         assert(rvalue);
 865
 866         if (isempty(rvalue) || parse_boolean(rvalue) == 0) {
 867                 *table = 0; /* Disabled. */
 868                 return 0;
 869         }
 870
 871         r = manager_get_route_table_from_string(netdev->manager, rvalue, table);
 872         if (r < 0) {
 873                 log_syntax(unit, LOG_WARNING, filename, line, r,
 874                            "Failed to parse %s=, ignoring assignment: %s",
 875                            lvalue, rvalue);
 876                 return 0;
 877         }
 878
 879         return 0;
 880 }
 881
 882 int config_parse_wireguard_peer_route_table(
 883                 const char *unit,
 884                 const char *filename,
 885                 unsigned line,
 886                 const char *section,
 887                 unsigned section_line,
 888                 const char *lvalue,
 889                 int ltype,
 890                 const char *rvalue,
 891                 void *data,
 892                 void *userdata) {
 893
 894         Wireguard *w = WIREGUARD(userdata);
 895         _cleanup_(wireguard_peer_free_or_set_invalidp) WireguardPeer *peer = NULL;
 896         int r;
 897
 898         assert(filename);
 899         assert(lvalue);
 900         assert(rvalue);
 901         assert(NETDEV(w)->manager);
 902
 903         r = wireguard_peer_new_static(w, filename, section_line, &peer);
 904         if (r < 0)
 905                 return log_oom();
 906
 907         if (isempty(rvalue)) {
 908                 peer->route_table_set = false; /* Use the table specified in [WireGuard] section. */
 909                 TAKE_PTR(peer);
 910                 return 0;
 911         }
 912
 913         if (parse_boolean(rvalue) == 0) {
 914                 peer->route_table = 0; /* Disabled. */
 915                 peer->route_table_set = true;
 916                 TAKE_PTR(peer);
 917                 return 0;
 918         }
 919
 920         r = manager_get_route_table_from_string(NETDEV(w)->manager, rvalue, &peer->route_table);
 921         if (r < 0) {
 922                 log_syntax(unit, LOG_WARNING, filename, line, r,
 923                            "Failed to parse %s=, ignoring assignment: %s",
 924                            lvalue, rvalue);
 925                 return 0;
 926         }
 927
 928         peer->route_table_set = true;
 929         TAKE_PTR(peer);
 930         return 0;
 931 }
 932
 933 int config_parse_wireguard_route_priority(
 934                 const char *unit,
 935                 const char *filename,
 936                 unsigned line,
 937                 const char *section,
 938                 unsigned section_line,
 939                 const char *lvalue,
 940                 int ltype,
 941                 const char *rvalue,
 942                 void *data,
 943                 void *userdata) {
 944
 945         uint32_t *priority = ASSERT_PTR(data);
 946         int r;
 947
 948         assert(filename);
 949         assert(lvalue);
 950         assert(rvalue);
 951
 952         if (isempty(rvalue)) {
 953                 *priority = 0;
 954                 return 0;
 955         }
 956
 957         r = safe_atou32(rvalue, priority);
 958         if (r < 0) {
 959                 log_syntax(unit, LOG_WARNING, filename, line, r,
 960                            "Could not parse route priority \"%s\", ignoring assignment: %m", rvalue);
 961                 return 0;
 962         }
 963
 964         return 0;
 965 }
 966
 967 int config_parse_wireguard_peer_route_priority(
 968                 const char *unit,
 969                 const char *filename,
 970                 unsigned line,
 971                 const char *section,
 972                 unsigned section_line,
 973                 const char *lvalue,
 974                 int ltype,
 975                 const char *rvalue,
 976                 void *data,
 977                 void *userdata) {
 978
 979         _cleanup_(wireguard_peer_free_or_set_invalidp) WireguardPeer *peer = NULL;
 980         Wireguard *w;
 981         int r;
 982
 983         assert(filename);
 984         assert(lvalue);
 985         assert(rvalue);
 986         assert(userdata);
 987
 988         w = WIREGUARD(userdata);
 989         assert(w);
 990
 991         r = wireguard_peer_new_static(w, filename, section_line, &peer);
 992         if (r < 0)
 993                 return log_oom();
 994
 995         if (isempty(rvalue)) {
 996                 peer->route_priority_set = false; /* Use the priority specified in [WireGuard] section. */
 997                 TAKE_PTR(peer);
 998                 return 0;
 999         }
1000
1001         r = safe_atou32(rvalue, &peer->route_priority);
1002         if (r < 0) {
1003                 log_syntax(unit, LOG_WARNING, filename, line, r,
1004                            "Could not parse route priority \"%s\", ignoring assignment: %m", rvalue);
1005                 return 0;
1006         }
1007
1008         peer->route_priority_set = true;
1009         TAKE_PTR(peer);
1010         return 0;
1011 }
1012
1013 static void wireguard_init(NetDev *netdev) {
1014         Wireguard *w = WIREGUARD(netdev);
1015
1016         w->flags = WGDEVICE_F_REPLACE_PEERS;
1017 }
1018
1019 static void wireguard_done(NetDev *netdev) {
1020         Wireguard *w = WIREGUARD(netdev);
1021
1022         explicit_bzero_safe(w->private_key, WG_KEY_LEN);
1023         free(w->private_key_file);
1024
1025         hashmap_free_with_destructor(w->peers_by_section, wireguard_peer_free);
1026
1027         set_free(w->routes);
1028 }
1029
1030 static int wireguard_read_key_file(const char *filename, uint8_t dest[static WG_KEY_LEN]) {
1031         _cleanup_(erase_and_freep) char *key = NULL;
1032         size_t key_len;
1033         int r;
1034
1035         if (!filename)
1036                 return 0;
1037
1038         assert(dest);
1039
1040         r = read_full_file_full(
1041                         AT_FDCWD, filename, UINT64_MAX, SIZE_MAX,
1042                         READ_FULL_FILE_SECURE | READ_FULL_FILE_UNBASE64 | READ_FULL_FILE_WARN_WORLD_READABLE | READ_FULL_FILE_CONNECT_SOCKET,
1043                         NULL, &key, &key_len);
1044         if (r < 0)
1045                 return r;
1046
1047         if (key_len != WG_KEY_LEN)
1048                 return -EINVAL;
1049
1050         memcpy(dest, key, WG_KEY_LEN);
1051         return 0;
1052 }
1053
1054 static int wireguard_peer_verify(WireguardPeer *peer) {
1055         NetDev *netdev = NETDEV(peer->wireguard);
1056         int r;
1057
1058         if (section_is_invalid(peer->section))
1059                 return -EINVAL;
1060
1061         if (eqzero(peer->public_key))
1062                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
1063                                               "%s: WireGuardPeer section without PublicKey= configured. "
1064                                               "Ignoring [WireGuardPeer] section from line %u.",
1065                                               peer->section->filename, peer->section->line);
1066
1067         r = wireguard_read_key_file(peer->preshared_key_file, peer->preshared_key);
1068         if (r < 0)
1069                 return log_netdev_error_errno(netdev, r,
1070                                               "%s: Failed to read preshared key from '%s'. "
1071                                               "Ignoring [WireGuardPeer] section from line %u.",
1072                                               peer->section->filename, peer->preshared_key_file,
1073                                               peer->section->line);
1074
1075         return 0;
1076 }
1077
1078 static int wireguard_verify(NetDev *netdev, const char *filename) {
1079         Wireguard *w = WIREGUARD(netdev);
1080         int r;
1081
1082         r = wireguard_read_key_file(w->private_key_file, w->private_key);
1083         if (r < 0)
1084                 return log_netdev_error_errno(netdev, r,
1085                                               "Failed to read private key from %s. Ignoring network device.",
1086                                               w->private_key_file);
1087
1088         if (eqzero(w->private_key))
1089                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
1090                                               "%s: Missing PrivateKey= or PrivateKeyFile=, "
1091                                               "Ignoring network device.", filename);
1092
1093         LIST_FOREACH(peers, peer, w->peers) {
1094                 if (wireguard_peer_verify(peer) < 0) {
1095                         wireguard_peer_free(peer);
1096                         continue;
1097                 }
1098
1099                 if ((peer->route_table_set ? peer->route_table : w->route_table) == 0)
1100                         continue;
1101
1102                 LIST_FOREACH(ipmasks, ipmask, peer->ipmasks) {
1103                         _cleanup_(route_freep) Route *route = NULL;
1104
1105                         r = route_new(&route);
1106                         if (r < 0)
1107                                 return log_oom();
1108
1109                         route->family = ipmask->family;
1110                         route->dst = ipmask->ip;
1111                         route->dst_prefixlen = ipmask->cidr;
1112                         route->scope = RT_SCOPE_UNIVERSE;
1113                         route->protocol = RTPROT_STATIC;
1114                         route->table = peer->route_table_set ? peer->route_table : w->route_table;
1115                         route->priority = peer->route_priority_set ? peer->route_priority : w->route_priority;
1116                         if (route->priority == 0 && route->family == AF_INET6)
1117                                 route->priority = IP6_RT_PRIO_USER;
1118                         route->source = NETWORK_CONFIG_SOURCE_STATIC;
1119
1120                         r = set_ensure_consume(&w->routes, &route_hash_ops, TAKE_PTR(route));
1121                         if (r < 0)
1122                                 return log_oom();
1123                 }
1124         }
1125
1126         return 0;
1127 }
1128
1129 const NetDevVTable wireguard_vtable = {
1130         .object_size = sizeof(Wireguard),
1131         .sections = NETDEV_COMMON_SECTIONS "WireGuard\0WireGuardPeer\0",
1132         .post_create = netdev_wireguard_post_create,
1133         .init = wireguard_init,
1134         .done = wireguard_done,
1135         .create_type = NETDEV_CREATE_INDEPENDENT,
1136         .config_verify = wireguard_verify,
1137         .iftype = ARPHRD_NONE,
1138 };