pex.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2022 Felix Fietkau <nbd@nbd.name>
   4  */
   5 #include <sys/types.h>
   6 #include <sys/socket.h>
   7 #include <arpa/inet.h>
   8 #include <netinet/in.h>
   9 #include <netinet/ip.h>
  10 #include <netinet/ip6.h>
  11 #include <netinet/udp.h>
  12 #include <fcntl.h>
  13 #include <stdlib.h>
  14 #include <inttypes.h>
  15 #include "unetd.h"
  16 #include "pex-msg.h"
  17
  18 static const char *pex_peer_id_str(const uint8_t *key)
  19 {
  20         static char str[20];
  21         int i;
  22
  23         for (i = 0; i < 8; i++)
  24                 sprintf(str + i * 2, "%02x", key[i]);
  25
  26         return str;
  27 }
  28
  29 static struct pex_hdr *
  30 pex_msg_init(struct network *net, uint8_t opcode)
  31 {
  32         return __pex_msg_init(net->config.pubkey, opcode);
  33 }
  34
  35 static struct pex_hdr *
  36 pex_msg_init_ext(struct network *net, uint8_t opcode, bool ext)
  37 {
  38         return __pex_msg_init_ext(net->config.pubkey, net->config.auth_key, opcode, ext);
  39 }
  40
  41 static struct network_peer *
  42 pex_msg_peer(struct network *net, const uint8_t *id)
  43 {
  44         struct network_peer *peer;
  45         uint8_t key[WG_KEY_LEN] = {};
  46
  47         memcpy(key, id, PEX_ID_LEN);
  48         peer = avl_find_ge_element(&net->peers.avl, key, peer, node.avl);
  49         if (!peer || memcmp(peer->key, key, PEX_ID_LEN) != 0) {
  50                 D_NET(net, "can't find peer %s", pex_peer_id_str(id));
  51                 return NULL;
  52         }
  53
  54         return peer;
  55 }
  56
  57 static void
  58 pex_get_peer_addr(struct sockaddr_in6 *sin6, struct network *net,
  59                   struct network_peer *peer)
  60 {
  61         *sin6 = (struct sockaddr_in6){
  62                 .sin6_family = AF_INET6,
  63                 .sin6_addr = peer->local_addr.in6,
  64                 .sin6_port = htons(peer->pex_port),
  65         };
  66 }
  67
  68 static void pex_msg_send(struct network *net, struct network_peer *peer)
  69 {
  70         struct sockaddr_in6 sin6 = {};
  71
  72         if (!peer || peer == &net->net_config.local_host->peer ||
  73             !peer->pex_port)
  74                 return;
  75
  76         pex_get_peer_addr(&sin6, net, peer);
  77         if (__pex_msg_send(net->pex.fd.fd, &sin6, NULL, 0) < 0)
  78                 D_PEER(net, peer, "pex_msg_send failed: %s", strerror(errno));
  79 }
  80
  81 static void pex_msg_send_ext(struct network *net, struct network_peer *peer,
  82                              struct sockaddr_in6 *addr)
  83 {
  84         char addrbuf[INET6_ADDRSTRLEN];
  85
  86         if (!addr)
  87                 return pex_msg_send(net, peer);
  88
  89         if (__pex_msg_send(-1, addr, NULL, 0) < 0)
  90                 D_NET(net, "pex_msg_send_ext(%s) failed: %s",
  91                       inet_ntop(addr->sin6_family, (const void *)&addr->sin6_addr, addrbuf,
  92                                 sizeof(addrbuf)),
  93                       strerror(errno));
  94 }
  95
  96 static void
  97 pex_send_hello(struct network *net, struct network_peer *peer)
  98 {
  99         struct pex_hello *data;
 100
 101         pex_msg_init(net, PEX_MSG_HELLO);
 102         data = pex_msg_append(sizeof(*data));
 103         if (peer->state.endpoint.sa.sa_family == AF_INET6)
 104             data->flags |= htons(PEER_EP_F_IPV6);
 105         if (network_get_local_addr(&data->local_addr, &peer->state.endpoint))
 106                 return;
 107
 108         pex_msg_send(net, peer);
 109 }
 110
 111 static int
 112 pex_msg_add_peer_endpoint(struct network *net, struct network_peer *peer,
 113                           struct network_peer *receiver)
 114 {
 115         struct pex_peer_endpoint *data;
 116         uint16_t flags = 0;
 117         const void *addr;
 118         int port;
 119         int len;
 120
 121         addr = network_endpoint_addr(&peer->state.endpoint, &len);
 122         port = peer->state.endpoint.in.sin_port;
 123         if (len > 4)
 124                 flags |= PEER_EP_F_IPV6;
 125         if (network_endpoint_addr_equal(&peer->state.endpoint,
 126                                         &receiver->state.endpoint)) {
 127                 if (!peer->state.has_local_ep_addr) {
 128                         D_PEER(net, peer, "can't send peer to %s, missing local address",
 129                                network_peer_name(receiver));
 130                         return -1;
 131                 }
 132
 133                 addr = &peer->state.local_ep_addr;
 134                 port = htons(peer->port);
 135                 flags |= PEER_EP_F_LOCAL;
 136         }
 137
 138         data = pex_msg_append(sizeof(*data));
 139         if (!data)
 140                 return -1;
 141
 142         memcpy(data->peer_id, peer->key, sizeof(data->peer_id));
 143         memcpy(data->addr, addr, len);
 144         data->port = port;
 145         data->flags = htons(flags);
 146         D_PEER(net, peer, "send endpoint to %s", network_peer_name(receiver));
 147
 148         return 0;
 149 }
 150
 151 static void
 152 network_pex_handle_endpoint_change(struct network *net, struct network_peer *peer)
 153 {
 154         struct network_peer *cur;
 155
 156         vlist_for_each_element(&net->peers, cur, node) {
 157                 if (cur == peer || !cur->state.connected)
 158                         continue;
 159
 160                 pex_msg_init(net, PEX_MSG_NOTIFY_PEERS);
 161                 if (pex_msg_add_peer_endpoint(net, peer, cur))
 162                         continue;
 163
 164                 pex_msg_send(net, cur);
 165         }
 166 }
 167
 168 static void
 169 network_pex_host_send_endpoint_notify(struct network *net, struct network_pex_host *host)
 170 {
 171         union {
 172                 struct {
 173                         struct ip ip;
 174                         struct udphdr udp;
 175                 } ipv4;
 176                 struct {
 177                         struct ip6_hdr ip;
 178                         struct udphdr udp;
 179                 } ipv6;
 180         } packet = {};
 181         struct udphdr *udp;
 182         union network_endpoint dest_ep;
 183         union network_addr local_addr = {};
 184         int len;
 185
 186         pex_msg_init_ext(net, PEX_MSG_ENDPOINT_NOTIFY, true);
 187
 188         memcpy(&dest_ep, &host->endpoint, sizeof(dest_ep));
 189
 190         /* work around issue with local address lookup for local broadcast */
 191         if (host->endpoint.sa.sa_family == AF_INET) {
 192                 uint8_t *data = (uint8_t *)&dest_ep.in.sin_addr;
 193
 194                 if (data[3] == 0xff)
 195                         data[3] = 0xfe;
 196         }
 197         network_get_local_addr(&local_addr, &dest_ep);
 198
 199         memset(&dest_ep, 0, sizeof(dest_ep));
 200         dest_ep.sa.sa_family = host->endpoint.sa.sa_family;
 201         if (host->endpoint.sa.sa_family == AF_INET) {
 202                 packet.ipv4.ip = (struct ip){
 203                         .ip_hl = 5,
 204                         .ip_v = 4,
 205                         .ip_ttl = 64,
 206                         .ip_p = IPPROTO_UDP,
 207                         .ip_src = local_addr.in,
 208                         .ip_dst = host->endpoint.in.sin_addr,
 209                 };
 210                 dest_ep.in.sin_addr = host->endpoint.in.sin_addr;
 211                 udp = &packet.ipv4.udp;
 212                 len = sizeof(packet.ipv4);
 213         } else {
 214                 packet.ipv6.ip = (struct ip6_hdr){
 215                         .ip6_flow = htonl(6 << 28),
 216                         .ip6_hops = 128,
 217                         .ip6_nxt = IPPROTO_UDP,
 218                         .ip6_src = local_addr.in6,
 219                         .ip6_dst = host->endpoint.in6.sin6_addr,
 220                 };
 221                 dest_ep.in6.sin6_addr = host->endpoint.in6.sin6_addr;
 222                 udp = &packet.ipv6.udp;
 223                 len = sizeof(packet.ipv6);
 224         }
 225
 226         udp->uh_sport = htons(net->net_config.local_host->peer.port);
 227         udp->uh_dport = host->endpoint.in6.sin6_port;
 228
 229         if (__pex_msg_send(-1, &dest_ep, &packet, len) < 0)
 230                 D_NET(net, "pex_msg_send_raw failed: %s", strerror(errno));
 231 }
 232
 233
 234 static void
 235 network_pex_host_send_port_notify(struct network *net, struct network_pex_host *host)
 236 {
 237         struct pex_endpoint_port_notify *data;
 238
 239         if (!net->stun.port_ext)
 240                 return;
 241
 242         pex_msg_init_ext(net, PEX_MSG_ENDPOINT_PORT_NOTIFY, true);
 243
 244         data = pex_msg_append(sizeof(*data));
 245         data->port = htons(net->stun.port_ext);
 246
 247         __pex_msg_send(-1, &host->endpoint, NULL, 0);
 248 }
 249
 250 static void
 251 network_pex_host_request_update(struct network *net, struct network_pex_host *host)
 252 {
 253         char addrstr[INET6_ADDRSTRLEN];
 254         uint64_t version = 0;
 255
 256         host->last_ping = unet_gettime();
 257
 258         if (net->net_data_len)
 259                 version = net->net_data_version;
 260
 261         D("request network data from host %s",
 262           inet_ntop(host->endpoint.sa.sa_family,
 263                     (host->endpoint.sa.sa_family == AF_INET6 ?
 264                      (const void *)&host->endpoint.in6.sin6_addr :
 265                      (const void *)&host->endpoint.in.sin_addr),
 266                     addrstr, sizeof(addrstr)));
 267
 268         if (!pex_msg_update_request_init(net->config.pubkey, net->config.key,
 269                                          net->config.auth_key, &host->endpoint,
 270                                          version, true))
 271                 return;
 272
 273         __pex_msg_send(-1, &host->endpoint, NULL, 0);
 274
 275         if (!net->net_config.local_host)
 276                 return;
 277
 278         network_pex_host_send_port_notify(net, host);
 279         network_pex_host_send_endpoint_notify(net, host);
 280 }
 281
 282 static void
 283 network_pex_free_host(struct network *net, struct network_pex_host *host)
 284 {
 285         struct network_pex *pex = &net->pex;
 286
 287         pex->num_hosts--;
 288         list_del(&host->list);
 289         free(host);
 290 }
 291
 292 static void
 293 network_pex_request_update_cb(struct uloop_timeout *t)
 294 {
 295         struct network *net = container_of(t, struct network, pex.request_update_timer);
 296         struct network_pex *pex = &net->pex;
 297         struct network_pex_host *host, *tmp;
 298         uint64_t now = unet_gettime();
 299
 300         uloop_timeout_set(t, 500);
 301
 302         if (list_empty(&pex->hosts))
 303                 return;
 304
 305         list_for_each_entry_safe(host, tmp, &pex->hosts, list) {
 306                 if (host->timeout && host->timeout < now) {
 307                         network_pex_free_host(net, host);
 308                         continue;
 309                 }
 310
 311                 if (host->last_ping + 10 >= now)
 312                         continue;
 313
 314                 list_move_tail(&host->list, &pex->hosts);
 315                 network_pex_host_request_update(net, host);
 316         }
 317 }
 318
 319 void network_pex_init(struct network *net)
 320 {
 321         struct network_pex *pex = &net->pex;
 322
 323         memset(pex, 0, sizeof(*pex));
 324         pex->fd.fd = -1;
 325         INIT_LIST_HEAD(&pex->hosts);
 326         pex->request_update_timer.cb = network_pex_request_update_cb;
 327 }
 328
 329 static void
 330 network_pex_query_hosts(struct network *net)
 331 {
 332         struct network_host *host;
 333         int rv = rand();
 334         int hosts = 0;
 335         int i;
 336
 337         pex_msg_init(net, PEX_MSG_QUERY);
 338
 339         avl_for_each_element(&net->hosts, host, node) {
 340                 struct network_peer *peer = &host->peer;
 341                 void *id;
 342
 343                 if ((net->stun.port_ext && host == net->net_config.local_host) ||
 344                     peer->state.connected || peer->endpoint)
 345                         continue;
 346
 347                 id = pex_msg_append(PEX_ID_LEN);
 348                 if (!id)
 349                         break;
 350
 351                 memcpy(id, peer->key, PEX_ID_LEN);
 352                 hosts++;
 353         }
 354
 355         if (!hosts)
 356                 return;
 357
 358         rv %= net->hosts.count;
 359         for (i = 0; i < 2; i++) {
 360                 avl_for_each_element(&net->hosts, host, node) {
 361                         struct network_peer *peer = &host->peer;
 362
 363                         if (rv > 0) {
 364                                 rv--;
 365                                 continue;
 366                         }
 367
 368                         if (host == net->net_config.local_host)
 369                                 continue;
 370
 371                         if (!peer->state.connected)
 372                                 continue;
 373
 374                         D_PEER(net, peer, "send query for %d hosts", hosts);
 375                         pex_msg_send(net, peer);
 376                         return;
 377                 }
 378         }
 379
 380 }
 381
 382 static void
 383 network_pex_send_ping(struct network *net, struct network_peer *peer)
 384 {
 385         if (peer->state.pinged || !peer->state.endpoint.sa.sa_family)
 386                 return;
 387
 388         pex_msg_init(net, PEX_MSG_PING);
 389         pex_msg_send(net, peer);
 390         peer->state.pinged = true;
 391 }
 392
 393 static void
 394 network_pex_send_update_request(struct network *net, struct network_peer *peer,
 395                                 struct sockaddr_in6 *addr)
 396 {
 397         union network_endpoint ep = {};
 398         uint64_t version = 0;
 399
 400         if (addr)
 401                 memcpy(&ep.in6, addr, sizeof(ep.in6));
 402         else
 403                 pex_get_peer_addr(&ep.in6, net, peer);
 404
 405         if (net->net_data_len)
 406                 version = net->net_data_version;
 407
 408         if (!pex_msg_update_request_init(net->config.pubkey, net->config.key,
 409                                          net->config.auth_key, &ep,
 410                                          version, !!addr))
 411                 return;
 412
 413         pex_msg_send_ext(net, peer, addr);
 414 }
 415
 416 void network_pex_event(struct network *net, struct network_peer *peer,
 417                        enum pex_event ev)
 418 {
 419         if (!network_pex_active(&net->pex))
 420                 return;
 421
 422         switch (ev) {
 423         case PEX_EV_HANDSHAKE:
 424                 pex_send_hello(net, peer);
 425                 if (net->config.type == NETWORK_TYPE_DYNAMIC)
 426                         network_pex_send_update_request(net, peer, NULL);
 427                 break;
 428         case PEX_EV_ENDPOINT_CHANGE:
 429                 network_pex_handle_endpoint_change(net, peer);
 430                 break;
 431         case PEX_EV_QUERY:
 432                 network_pex_query_hosts(net);
 433                 break;
 434         case PEX_EV_PING:
 435                 network_pex_send_ping(net, peer);
 436                 break;
 437         }
 438 }
 439
 440 static void
 441 network_pex_recv_hello(struct network *net, struct network_peer *peer,
 442                        const struct pex_hello *data, size_t len)
 443 {
 444         char addrstr[INET6_ADDRSTRLEN];
 445         uint16_t flags;
 446         int af;
 447
 448         if (len < sizeof(*data))
 449                 return;
 450
 451         if (peer->state.has_local_ep_addr &&
 452             !memcmp(&peer->state.local_ep_addr, data->local_addr, sizeof(data->local_addr)))
 453                 return;
 454
 455         flags = ntohs(data->flags);
 456         af = (flags & PEER_EP_F_IPV6) ? AF_INET6 : AF_INET;
 457         D_PEER(net, peer, "set local endpoint address to %s",
 458                inet_ntop(af, data->local_addr, addrstr, sizeof(addrstr)));
 459         peer->state.has_local_ep_addr = true;
 460         memcpy(&peer->state.local_ep_addr, data->local_addr, sizeof(data->local_addr));
 461 }
 462
 463 static void
 464 network_pex_recv_peers(struct network *net, struct network_peer *peer,
 465                        const struct pex_peer_endpoint *data, size_t len)
 466 {
 467         struct network_peer *local = &net->net_config.local_host->peer;
 468         struct network_peer *cur;
 469
 470         for (; len >= sizeof(*data); len -= sizeof(*data), data++) {
 471                 union network_endpoint *ep;
 472                 uint16_t flags;
 473                 void *addr;
 474                 int len;
 475
 476                 if (!memcmp(data->peer_id, &local->key, PEX_ID_LEN)) {
 477                         network_stun_update_port(net, false, ntohs(data->port));
 478                         continue;
 479                 }
 480
 481                 cur = pex_msg_peer(net, data->peer_id);
 482                 if (!cur || cur == peer)
 483                         continue;
 484
 485                 D_PEER(net, peer, "received peer address for %s",
 486                        network_peer_name(cur));
 487                 flags = ntohs(data->flags);
 488                 ep = &cur->state.next_endpoint;
 489                 ep->sa.sa_family = (flags & PEER_EP_F_IPV6) ? AF_INET6 : AF_INET;
 490                 addr = network_endpoint_addr(ep, &len);
 491                 memcpy(addr, data->addr, len);
 492                 ep->in.sin_port = data->port;
 493         }
 494 }
 495
 496 static void
 497 network_pex_recv_query(struct network *net, struct network_peer *peer,
 498                        const uint8_t *data, size_t len)
 499 {
 500         struct network_peer *cur;
 501         int resp = 0;
 502
 503         pex_msg_init(net, PEX_MSG_NOTIFY_PEERS);
 504         for (; len >= 8; data += 8, len -= 8) {
 505                 cur = pex_msg_peer(net, data);
 506                 if (!cur || !cur->state.connected)
 507                         continue;
 508
 509                 if (!pex_msg_add_peer_endpoint(net, cur, peer))
 510                         resp++;
 511         }
 512
 513         if (!resp)
 514                 return;
 515
 516         D_PEER(net, peer, "send query response with %d hosts", resp);
 517         pex_msg_send(net, peer);
 518 }
 519
 520 static void
 521 network_pex_recv_ping(struct network *net, struct network_peer *peer)
 522 {
 523         time_t now = time(NULL);
 524
 525         if (peer->state.last_request == now)
 526                 return;
 527
 528         peer->state.last_request = now;
 529         pex_msg_init(net, PEX_MSG_PONG);
 530         pex_msg_send(net, peer);
 531 }
 532
 533 static void
 534 network_pex_recv_update_request(struct network *net, struct network_peer *peer,
 535                                 const uint8_t *data, size_t len,
 536                                 struct sockaddr_in6 *addr)
 537 {
 538         struct pex_update_request *req = (struct pex_update_request *)data;
 539         struct pex_msg_update_send_ctx ctx = {};
 540         uint64_t req_version = be64_to_cpu(req->cur_version);
 541         int *query_count;
 542         bool done = false;
 543
 544         if (len < sizeof(struct pex_update_request))
 545                 return;
 546
 547         if (net->config.type != NETWORK_TYPE_DYNAMIC)
 548                 return;
 549
 550         if (peer)
 551                 query_count = &peer->state.num_net_queries;
 552         else
 553                 query_count = &net->num_net_queries;
 554
 555         if (++*query_count > 10)
 556                 return;
 557
 558         D("receive update request, local version=%"PRIu64", remote version=%"PRIu64, net->net_data_version, req_version);
 559
 560         if (req_version >= net->net_data_version) {
 561                 struct pex_update_response_no_data *res;
 562
 563                 pex_msg_init_ext(net, PEX_MSG_UPDATE_RESPONSE_NO_DATA, !!addr);
 564                 res = pex_msg_append(sizeof(*res));
 565                 res->req_id = req->req_id;
 566                 res->cur_version = cpu_to_be64(net->net_data_version);
 567                 pex_msg_send_ext(net, peer, addr);
 568         }
 569
 570         if (req_version > net->net_data_version)
 571                 network_pex_send_update_request(net, peer, addr);
 572
 573         if (!peer || !net->net_data_len)
 574                 return;
 575
 576         if (req_version >= net->net_data_version)
 577                 return;
 578
 579         pex_msg_update_response_init(&ctx, net->config.pubkey, net->config.auth_key,
 580                                      peer->key, !!addr, (void *)data,
 581                                      net->net_data, net->net_data_len);
 582         while (!done) {
 583                 pex_msg_send_ext(net, peer, addr);
 584                 done = !pex_msg_update_response_continue(&ctx);
 585         }
 586 }
 587
 588 static void
 589 network_pex_recv_update_response(struct network *net, const uint8_t *data, size_t len,
 590                               struct sockaddr_in6 *addr, enum pex_opcode op)
 591 {
 592         struct network_peer *peer;
 593         void *net_data;
 594         int net_data_len = 0;
 595         uint64_t version = 0;
 596         bool no_prev_data = !net->net_data_len;
 597
 598         if (net->config.type != NETWORK_TYPE_DYNAMIC)
 599                 return;
 600
 601         net_data = pex_msg_update_response_recv(data, len, op, &net_data_len, &version);
 602         if (!net_data)
 603                 return;
 604
 605         if (version <= net->net_data_version) {
 606                 free(net_data);
 607                 return;
 608         }
 609
 610         D_NET(net, "received updated network data, len=%d", net_data_len);
 611         free(net->net_data);
 612
 613         net->net_data = net_data;
 614         net->net_data_len = net_data_len;
 615         net->net_data_version = version;
 616         if (network_save_dynamic(net) < 0)
 617                 return;
 618
 619         uloop_timeout_set(&net->reload_timer, no_prev_data ? 1 : UNETD_DATA_UPDATE_DELAY);
 620         vlist_for_each_element(&net->peers, peer, node) {
 621                 if (!peer->state.connected || !peer->pex_port)
 622                         continue;
 623                 network_pex_send_update_request(net, peer, NULL);
 624         }
 625 }
 626
 627 static void
 628 network_pex_recv(struct network *net, struct network_peer *peer, struct pex_hdr *hdr)
 629 {
 630         const void *data = hdr + 1;
 631
 632         if (hdr->version != 0)
 633                 return;
 634
 635         D_PEER(net, peer, "PEX rx op=%d", hdr->opcode);
 636         switch (hdr->opcode) {
 637         case PEX_MSG_HELLO:
 638                 network_pex_recv_hello(net, peer, data, hdr->len);
 639                 break;
 640         case PEX_MSG_NOTIFY_PEERS:
 641                 network_pex_recv_peers(net, peer, data, hdr->len);
 642                 break;
 643         case PEX_MSG_QUERY:
 644                 network_pex_recv_query(net, peer, data, hdr->len);
 645                 break;
 646         case PEX_MSG_PING:
 647                 network_pex_recv_ping(net, peer);
 648                 break;
 649         case PEX_MSG_PONG:
 650                 break;
 651         case PEX_MSG_UPDATE_REQUEST:
 652                 network_pex_recv_update_request(net, peer, data, hdr->len,
 653                                                 NULL);
 654                 break;
 655         case PEX_MSG_UPDATE_RESPONSE:
 656         case PEX_MSG_UPDATE_RESPONSE_DATA:
 657         case PEX_MSG_UPDATE_RESPONSE_NO_DATA:
 658                 network_pex_recv_update_response(net, data, hdr->len,
 659                                               NULL, hdr->opcode);
 660                 break;
 661         case PEX_MSG_ENDPOINT_NOTIFY:
 662                 break;
 663         }
 664 }
 665
 666 static void
 667 network_pex_fd_cb(struct uloop_fd *fd, unsigned int events)
 668 {
 669         struct network *net = container_of(fd, struct network, pex.fd);
 670         struct network_peer *local = &net->net_config.local_host->peer;
 671         struct network_peer *peer;
 672         struct sockaddr_in6 sin6;
 673         static char buf[PEX_BUF_SIZE];
 674         struct pex_hdr *hdr = (struct pex_hdr *)buf;
 675         ssize_t len;
 676
 677         while (1) {
 678                 socklen_t slen = sizeof(sin6);
 679
 680                 len = recvfrom(fd->fd, buf, sizeof(buf), 0, (struct sockaddr *)&sin6, &slen);
 681                 if (len < 0) {
 682                         if (errno == EINTR)
 683                                 continue;
 684
 685                         if (errno == EAGAIN)
 686                                 break;
 687
 688                         D_NET(net, "recvfrom failed: %s", strerror(errno));
 689                         network_pex_close(net);
 690                         return;
 691                 }
 692
 693                 if (!len)
 694                         continue;
 695
 696                 hdr = pex_rx_accept(buf, len, false);
 697                 if (!hdr)
 698                         continue;
 699
 700                 peer = pex_msg_peer(net, hdr->id);
 701                 if (!peer)
 702                         continue;
 703
 704                 if (memcmp(&sin6.sin6_addr, &peer->local_addr.in6, sizeof(sin6.sin6_addr)) != 0)
 705                         continue;
 706
 707                 if (peer == local)
 708                         continue;
 709
 710                 network_pex_recv(net, peer, hdr);
 711         }
 712 }
 713
 714 void network_pex_create_host(struct network *net, union network_endpoint *ep,
 715                              unsigned int timeout)
 716 {
 717         struct network_pex *pex = &net->pex;
 718         struct network_pex_host *host;
 719         uint64_t now = unet_gettime();
 720         bool new_host = false;
 721
 722         list_for_each_entry(host, &pex->hosts, list) {
 723                 if (memcmp(&host->endpoint, ep, sizeof(host->endpoint)) != 0)
 724                         continue;
 725
 726                 if (host->last_ping + 10 < now) {
 727                         list_move_tail(&host->list, &pex->hosts);
 728                         network_pex_host_request_update(net, host);
 729                 }
 730                 goto out;
 731         }
 732
 733         host = calloc(1, sizeof(*host));
 734         new_host = true;
 735         memcpy(&host->endpoint, ep, sizeof(host->endpoint));
 736         list_add_tail(&host->list, &pex->hosts);
 737         pex->num_hosts++;
 738
 739 out:
 740         if (timeout && (new_host || host->timeout))
 741                 host->timeout = timeout + unet_gettime();
 742 }
 743
 744 static void
 745 network_pex_open_auth_connect(struct network *net)
 746 {
 747         struct network_pex *pex = &net->pex;
 748         struct network_peer *peer;
 749         struct blob_attr *cur;
 750         int rem;
 751
 752         if (net->config.type != NETWORK_TYPE_DYNAMIC)
 753                 return;
 754
 755         uloop_timeout_set(&pex->request_update_timer, 5000);
 756
 757         vlist_for_each_element(&net->peers, peer, node) {
 758                 union network_endpoint ep = {};
 759
 760                 if (!peer->endpoint || peer->dynamic)
 761                         continue;
 762
 763                 if (network_get_endpoint(&ep, AF_UNSPEC, peer->endpoint,
 764                                          UNETD_GLOBAL_PEX_PORT, 0) < 0)
 765                         continue;
 766
 767                 ep.in.sin_port = htons(UNETD_GLOBAL_PEX_PORT);
 768                 network_pex_create_host(net, &ep, 0);
 769         }
 770
 771         if (!net->config.auth_connect)
 772                 return;
 773
 774         blobmsg_for_each_attr(cur, net->config.auth_connect, rem) {
 775                 union network_endpoint ep = {};
 776
 777                 if (network_get_endpoint(&ep, AF_UNSPEC, blobmsg_get_string(cur),
 778                                          UNETD_GLOBAL_PEX_PORT, 0) < 0)
 779                         continue;
 780
 781                 network_pex_create_host(net, &ep, 0);
 782         }
 783 }
 784
 785
 786 int network_pex_open(struct network *net)
 787 {
 788         struct network_host *local_host = net->net_config.local_host;
 789         struct network_peer *local;
 790         struct network_pex *pex = &net->pex;
 791         struct sockaddr_in6 sin6 = {};
 792         int yes = 1;
 793         int fd;
 794
 795         network_pex_open_auth_connect(net);
 796
 797         if (!local_host || !local_host->peer.pex_port)
 798                 return 0;
 799
 800         local = &local_host->peer;
 801         fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
 802         if (fd < 0)
 803                 return -1;
 804
 805         fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
 806         fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
 807
 808         sin6.sin6_family = AF_INET6;
 809         memcpy(&sin6.sin6_addr, &local->local_addr.in6,
 810                sizeof(local->local_addr.in6));
 811         sin6.sin6_port = htons(local_host->peer.pex_port);
 812
 813         if (bind(fd, (struct sockaddr *)&sin6, sizeof(sin6)) < 0) {
 814                 perror("bind");
 815                 goto close;
 816         }
 817
 818         setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
 819         setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &yes, sizeof(yes));
 820 #ifdef linux
 821         setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
 822                    network_name(net), strlen(network_name(net)));
 823 #endif
 824
 825         pex->fd.fd = fd;
 826         pex->fd.cb = network_pex_fd_cb;
 827         uloop_fd_add(&pex->fd, ULOOP_READ);
 828
 829         return 0;
 830
 831 close:
 832         close(fd);
 833         return -1;
 834 }
 835
 836 void network_pex_close(struct network *net)
 837 {
 838         struct network_pex *pex = &net->pex;
 839         struct network_pex_host *host, *tmp;
 840         uint64_t now = unet_gettime();
 841
 842         uloop_timeout_cancel(&pex->request_update_timer);
 843         list_for_each_entry_safe(host, tmp, &pex->hosts, list) {
 844                 if (host->timeout)
 845                         continue;
 846
 847                 if (host->last_active + UNETD_PEX_HOST_ACITVE_TIMEOUT >= now)
 848                         continue;
 849
 850                 network_pex_free_host(net, host);
 851         }
 852
 853         if (pex->fd.fd < 0)
 854                 return;
 855
 856         uloop_fd_delete(&pex->fd);
 857         close(pex->fd.fd);
 858         network_pex_init(net);
 859 }
 860
 861 void network_pex_free(struct network *net)
 862 {
 863         struct network_pex *pex = &net->pex;
 864         struct network_pex_host *host, *tmp;
 865
 866         list_for_each_entry_safe(host, tmp, &pex->hosts, list)
 867                 network_pex_free_host(net, host);
 868 }
 869
 870 static struct network *
 871 global_pex_find_network(const uint8_t *id)
 872 {
 873         struct network *net;
 874
 875         avl_for_each_element(&networks, net, node) {
 876                 if (!memcmp(id, net->config.auth_key, PEX_ID_LEN))
 877                         return net;
 878         }
 879
 880         return NULL;
 881 }
 882
 883 static void
 884 global_pex_set_active(struct network *net, struct sockaddr_in6 *addr)
 885 {
 886         struct network_pex *pex = &net->pex;
 887         struct network_pex_host *host;
 888
 889         list_for_each_entry(host, &pex->hosts, list) {
 890                 if (memcmp(&host->endpoint.in6, addr, sizeof(*addr)) != 0)
 891                         continue;
 892
 893                 host->last_active = unet_gettime();
 894         }
 895 }
 896
 897 static void
 898 global_pex_recv(void *msg, size_t msg_len, struct sockaddr_in6 *addr)
 899 {
 900         struct pex_hdr *hdr;
 901         struct pex_ext_hdr *ehdr;
 902         struct network_peer *peer;
 903         struct network *net;
 904         char buf[INET6_ADDRSTRLEN];
 905         void *data;
 906         int addr_len;
 907
 908         if (stun_msg_is_valid(msg, msg_len)) {
 909                 avl_for_each_element(&networks, net, node)
 910                         network_stun_rx_packet(net, msg, msg_len);
 911         }
 912
 913         hdr = pex_rx_accept(msg, msg_len, true);
 914         if (!hdr)
 915                 return;
 916
 917         ehdr = (void *)(hdr + 1);
 918         data = (void *)(ehdr + 1);
 919
 920         if (hdr->version != 0)
 921                 return;
 922
 923         net = global_pex_find_network(ehdr->auth_id);
 924         if (!net || net->config.type != NETWORK_TYPE_DYNAMIC)
 925                 return;
 926
 927         *(uint64_t *)hdr->id ^= pex_network_hash(net->config.auth_key, ehdr->nonce);
 928
 929         global_pex_set_active(net, addr);
 930
 931         D("PEX global rx op=%d", hdr->opcode);
 932         switch (hdr->opcode) {
 933         case PEX_MSG_HELLO:
 934         case PEX_MSG_NOTIFY_PEERS:
 935         case PEX_MSG_QUERY:
 936         case PEX_MSG_PING:
 937         case PEX_MSG_PONG:
 938                 break;
 939         case PEX_MSG_UPDATE_REQUEST:
 940                 peer = pex_msg_peer(net, hdr->id);
 941                 network_pex_recv_update_request(net, peer, data, hdr->len,
 942                                                 addr);
 943                 break;
 944         case PEX_MSG_UPDATE_RESPONSE:
 945         case PEX_MSG_UPDATE_RESPONSE_DATA:
 946         case PEX_MSG_UPDATE_RESPONSE_NO_DATA:
 947                 network_pex_recv_update_response(net, data, hdr->len, addr, hdr->opcode);
 948                 break;
 949         case PEX_MSG_ENDPOINT_PORT_NOTIFY:
 950                 if (hdr->len < sizeof(struct pex_endpoint_port_notify))
 951                         break;
 952         case PEX_MSG_ENDPOINT_NOTIFY:
 953                 peer = pex_msg_peer(net, hdr->id);
 954                 if (!peer)
 955                         break;
 956
 957                 D_PEER(net, peer, "receive endpoint notification from %s",
 958                   inet_ntop(addr->sin6_family, network_endpoint_addr((void *)addr, &addr_len),
 959                             buf, sizeof(buf)));
 960
 961                 memcpy(&peer->state.next_endpoint, addr, sizeof(*addr));
 962                 if (hdr->opcode == PEX_MSG_ENDPOINT_PORT_NOTIFY) {
 963                         struct pex_endpoint_port_notify *port = data;
 964                         union network_endpoint host_ep = {
 965                                 .in6 = *addr
 966                         };
 967
 968                         peer->state.next_endpoint.in.sin_port = port->port;
 969                         if (net->pex.num_hosts < NETWORK_PEX_HOSTS_LIMIT)
 970                                 network_pex_create_host(net, &host_ep, 120);
 971                 }
 972                 break;
 973         }
 974 }
 975
 976 static void
 977 pex_recv_control(struct pex_msg_local_control *msg, int len)
 978 {
 979         struct network *net;
 980
 981         if (msg->msg_type != 0)
 982                 return;
 983
 984         net = global_pex_find_network(msg->auth_id);
 985         if (!net)
 986                 return;
 987
 988         if (!msg->timeout)
 989                 msg->timeout = 60;
 990         network_pex_create_host(net, &msg->ep, msg->timeout);
 991 }
 992
 993 int global_pex_open(const char *unix_path)
 994 {
 995         struct sockaddr_in6 sin6 = {};
 996         int ret;
 997
 998         sin6.sin6_family = AF_INET6;
 999         sin6.sin6_port = htons(global_pex_port);
1000
1001         ret = pex_open(&sin6, sizeof(sin6), global_pex_recv, true);
1002
1003         if (unix_path)
1004                 pex_unix_open(unix_path, pex_recv_control);
1005
1006         return ret;
1007 }