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_request_update(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         char addrstr[INET6_ADDRSTRLEN];
 183         union network_endpoint dest_ep;
 184         union network_addr local_addr = {};
 185         uint64_t version = 0;
 186         int len;
 187
 188         if (net->net_data_len)
 189                 version = net->net_data_version;
 190
 191         D("request network data from host %s",
 192           inet_ntop(host->endpoint.sa.sa_family,
 193                     (host->endpoint.sa.sa_family == AF_INET6 ?
 194                      (const void *)&host->endpoint.in6.sin6_addr :
 195                      (const void *)&host->endpoint.in.sin_addr),
 196                     addrstr, sizeof(addrstr)));
 197
 198         if (!pex_msg_update_request_init(net->config.pubkey, net->config.key,
 199                                          net->config.auth_key, &host->endpoint,
 200                                          version, true))
 201                 return;
 202
 203         __pex_msg_send(-1, &host->endpoint, NULL, 0);
 204
 205         if (!net->net_config.local_host)
 206                 return;
 207
 208         pex_msg_init_ext(net, PEX_MSG_ENDPOINT_NOTIFY, true);
 209
 210         memcpy(&dest_ep, &host->endpoint, sizeof(dest_ep));
 211
 212         /* work around issue with local address lookup for local broadcast */
 213         if (host->endpoint.sa.sa_family == AF_INET) {
 214                 uint8_t *data = (uint8_t *)&dest_ep.in.sin_addr;
 215
 216                 if (data[3] == 0xff)
 217                         data[3] = 0xfe;
 218         }
 219         network_get_local_addr(&local_addr, &dest_ep);
 220
 221         memset(&dest_ep, 0, sizeof(dest_ep));
 222         dest_ep.sa.sa_family = host->endpoint.sa.sa_family;
 223         if (host->endpoint.sa.sa_family == AF_INET) {
 224                 packet.ipv4.ip = (struct ip){
 225                         .ip_hl = 5,
 226                         .ip_v = 4,
 227                         .ip_ttl = 64,
 228                         .ip_p = IPPROTO_UDP,
 229                         .ip_src = local_addr.in,
 230                         .ip_dst = host->endpoint.in.sin_addr,
 231                 };
 232                 dest_ep.in.sin_addr = host->endpoint.in.sin_addr;
 233                 udp = &packet.ipv4.udp;
 234                 len = sizeof(packet.ipv4);
 235         } else {
 236                 packet.ipv6.ip = (struct ip6_hdr){
 237                         .ip6_flow = htonl(6 << 28),
 238                         .ip6_hops = 128,
 239                         .ip6_nxt = IPPROTO_UDP,
 240                         .ip6_src = local_addr.in6,
 241                         .ip6_dst = host->endpoint.in6.sin6_addr,
 242                 };
 243                 dest_ep.in6.sin6_addr = host->endpoint.in6.sin6_addr;
 244                 udp = &packet.ipv6.udp;
 245                 len = sizeof(packet.ipv6);
 246         }
 247
 248         udp->uh_sport = htons(net->net_config.local_host->peer.port);
 249         udp->uh_dport = host->endpoint.in6.sin6_port;
 250
 251         if (__pex_msg_send(-1, &dest_ep, &packet, len) < 0)
 252                 D_NET(net, "pex_msg_send_raw failed: %s", strerror(errno));
 253 }
 254
 255 static void
 256 network_pex_request_update_cb(struct uloop_timeout *t)
 257 {
 258         struct network *net = container_of(t, struct network, pex.request_update_timer);
 259         struct network_pex *pex = &net->pex;
 260         struct network_pex_host *host;
 261
 262         uloop_timeout_set(t, 5000);
 263
 264 retry:
 265         if (list_empty(&pex->hosts))
 266                 return;
 267
 268         host = list_first_entry(&pex->hosts, struct network_pex_host, list);
 269         if (host->timeout && host->timeout < unet_gettime()) {
 270                 list_del(&host->list);
 271                 free(host);
 272                 goto retry;
 273         }
 274
 275         list_move_tail(&host->list, &pex->hosts);
 276         network_pex_host_request_update(net, host);
 277 }
 278
 279 void network_pex_init(struct network *net)
 280 {
 281         struct network_pex *pex = &net->pex;
 282
 283         memset(pex, 0, sizeof(*pex));
 284         pex->fd.fd = -1;
 285         INIT_LIST_HEAD(&pex->hosts);
 286         pex->request_update_timer.cb = network_pex_request_update_cb;
 287 }
 288
 289 static void
 290 network_pex_query_hosts(struct network *net)
 291 {
 292         struct network_host *host;
 293         int rv = rand();
 294         int hosts = 0;
 295         int i;
 296
 297         pex_msg_init(net, PEX_MSG_QUERY);
 298
 299         avl_for_each_element(&net->hosts, host, node) {
 300                 struct network_peer *peer = &host->peer;
 301                 void *id;
 302
 303                 if (host == net->net_config.local_host ||
 304                     peer->state.connected ||
 305                     peer->endpoint)
 306                         continue;
 307
 308                 id = pex_msg_append(PEX_ID_LEN);
 309                 if (!id)
 310                         break;
 311
 312                 memcpy(id, peer->key, PEX_ID_LEN);
 313                 hosts++;
 314         }
 315
 316         if (!hosts)
 317                 return;
 318
 319         rv %= net->hosts.count;
 320         for (i = 0; i < 2; i++) {
 321                 avl_for_each_element(&net->hosts, host, node) {
 322                         struct network_peer *peer = &host->peer;
 323
 324                         if (rv > 0) {
 325                                 rv--;
 326                                 continue;
 327                         }
 328
 329                         if (host == net->net_config.local_host)
 330                                 continue;
 331
 332                         if (!peer->state.connected)
 333                                 continue;
 334
 335                         D_PEER(net, peer, "send query for %d hosts", hosts);
 336                         pex_msg_send(net, peer);
 337                         return;
 338                 }
 339         }
 340
 341 }
 342
 343 static void
 344 network_pex_send_ping(struct network *net, struct network_peer *peer)
 345 {
 346         pex_msg_init(net, PEX_MSG_PING);
 347         pex_msg_send(net, peer);
 348 }
 349
 350 static void
 351 network_pex_send_update_request(struct network *net, struct network_peer *peer,
 352                                 struct sockaddr_in6 *addr)
 353 {
 354         union network_endpoint ep = {};
 355         uint64_t version = 0;
 356
 357         if (addr)
 358                 memcpy(&ep.in6, addr, sizeof(ep.in6));
 359         else
 360                 pex_get_peer_addr(&ep.in6, net, peer);
 361
 362         if (net->net_data_len)
 363                 version = net->net_data_version;
 364
 365         if (!pex_msg_update_request_init(net->config.pubkey, net->config.key,
 366                                          net->config.auth_key, &ep,
 367                                          version, !!addr))
 368                 return;
 369
 370         pex_msg_send_ext(net, peer, addr);
 371 }
 372
 373 void network_pex_event(struct network *net, struct network_peer *peer,
 374                        enum pex_event ev)
 375 {
 376         if (!network_pex_active(&net->pex))
 377                 return;
 378
 379         if (peer)
 380                 D_PEER(net, peer, "PEX event type=%d", ev);
 381         else
 382                 D_NET(net, "PEX event type=%d", ev);
 383
 384         switch (ev) {
 385         case PEX_EV_HANDSHAKE:
 386                 pex_send_hello(net, peer);
 387                 if (net->config.type == NETWORK_TYPE_DYNAMIC)
 388                         network_pex_send_update_request(net, peer, NULL);
 389                 break;
 390         case PEX_EV_ENDPOINT_CHANGE:
 391                 network_pex_handle_endpoint_change(net, peer);
 392                 break;
 393         case PEX_EV_QUERY:
 394                 network_pex_query_hosts(net);
 395                 break;
 396         case PEX_EV_PING:
 397                 network_pex_send_ping(net, peer);
 398                 break;
 399         }
 400 }
 401
 402 static void
 403 network_pex_recv_hello(struct network *net, struct network_peer *peer,
 404                        const struct pex_hello *data, size_t len)
 405 {
 406         char addrstr[INET6_ADDRSTRLEN];
 407         uint16_t flags;
 408         int af;
 409
 410         if (len < sizeof(*data))
 411                 return;
 412
 413         if (peer->state.has_local_ep_addr &&
 414             !memcmp(&peer->state.local_ep_addr, data->local_addr, sizeof(data->local_addr)))
 415                 return;
 416
 417         flags = ntohs(data->flags);
 418         af = (flags & PEER_EP_F_IPV6) ? AF_INET6 : AF_INET;
 419         D_PEER(net, peer, "set local endpoint address to %s",
 420                inet_ntop(af, data->local_addr, addrstr, sizeof(addrstr)));
 421         peer->state.has_local_ep_addr = true;
 422         memcpy(&peer->state.local_ep_addr, data->local_addr, sizeof(data->local_addr));
 423 }
 424
 425 static void
 426 network_pex_recv_peers(struct network *net, struct network_peer *peer,
 427                        const struct pex_peer_endpoint *data, size_t len)
 428 {
 429         struct network_peer *local = &net->net_config.local_host->peer;
 430         struct network_peer *cur;
 431
 432         for (; len >= sizeof(*data); len -= sizeof(*data), data++) {
 433                 union network_endpoint *ep;
 434                 uint16_t flags;
 435                 void *addr;
 436                 int len;
 437
 438                 cur = pex_msg_peer(net, data->peer_id);
 439                 if (!cur)
 440                         continue;
 441
 442                 if (cur == peer || cur == local)
 443                         continue;
 444
 445                 D_PEER(net, peer, "received peer address for %s",
 446                        network_peer_name(cur));
 447                 flags = ntohs(data->flags);
 448                 ep = &cur->state.next_endpoint;
 449                 ep->sa.sa_family = (flags & PEER_EP_F_IPV6) ? AF_INET6 : AF_INET;
 450                 addr = network_endpoint_addr(ep, &len);
 451                 memcpy(addr, data->addr, len);
 452                 ep->in.sin_port = data->port;
 453         }
 454 }
 455
 456 static void
 457 network_pex_recv_query(struct network *net, struct network_peer *peer,
 458                        const uint8_t *data, size_t len)
 459 {
 460         struct network_peer *cur;
 461         int resp = 0;
 462
 463         pex_msg_init(net, PEX_MSG_NOTIFY_PEERS);
 464         for (; len >= 8; data += 8, len -= 8) {
 465                 cur = pex_msg_peer(net, data);
 466                 if (!cur || !cur->state.connected)
 467                         continue;
 468
 469                 if (!pex_msg_add_peer_endpoint(net, cur, peer))
 470                         resp++;
 471         }
 472
 473         if (!resp)
 474                 return;
 475
 476         D_PEER(net, peer, "send query response with %d hosts", resp);
 477         pex_msg_send(net, peer);
 478 }
 479
 480 static void
 481 network_pex_recv_ping(struct network *net, struct network_peer *peer)
 482 {
 483         time_t now = time(NULL);
 484
 485         if (peer->state.last_request == now)
 486                 return;
 487
 488         peer->state.last_request = now;
 489         pex_msg_init(net, PEX_MSG_PONG);
 490         pex_msg_send(net, peer);
 491 }
 492
 493 static void
 494 network_pex_recv_update_request(struct network *net, struct network_peer *peer,
 495                                 const uint8_t *data, size_t len,
 496                                 struct sockaddr_in6 *addr)
 497 {
 498         struct pex_update_request *req = (struct pex_update_request *)data;
 499         struct pex_msg_update_send_ctx ctx = {};
 500         uint64_t req_version = be64_to_cpu(req->cur_version);
 501         int *query_count;
 502         bool done = false;
 503
 504         if (len < sizeof(struct pex_update_request))
 505                 return;
 506
 507         if (net->config.type != NETWORK_TYPE_DYNAMIC)
 508                 return;
 509
 510         if (peer)
 511                 query_count = &peer->state.num_net_queries;
 512         else
 513                 query_count = &net->num_net_queries;
 514
 515         if (++*query_count > 10)
 516                 return;
 517
 518         D("receive update request, local version=%"PRIu64", remote version=%"PRIu64, net->net_data_version, req_version);
 519
 520         if (req_version >= net->net_data_version) {
 521                 struct pex_update_response_no_data *res;
 522
 523                 pex_msg_init_ext(net, PEX_MSG_UPDATE_RESPONSE_NO_DATA, !!addr);
 524                 res = pex_msg_append(sizeof(*res));
 525                 res->req_id = req->req_id;
 526                 res->cur_version = cpu_to_be64(net->net_data_version);
 527                 pex_msg_send_ext(net, peer, addr);
 528         }
 529
 530         if (req_version > net->net_data_version)
 531                 network_pex_send_update_request(net, peer, addr);
 532
 533         if (!peer || !net->net_data_len)
 534                 return;
 535
 536         if (req_version >= net->net_data_version)
 537                 return;
 538
 539         pex_msg_update_response_init(&ctx, net->config.pubkey, net->config.auth_key,
 540                                      peer->key, !!addr, (void *)data,
 541                                      net->net_data, net->net_data_len);
 542         while (!done) {
 543                 pex_msg_send_ext(net, peer, addr);
 544                 done = !pex_msg_update_response_continue(&ctx);
 545         }
 546 }
 547
 548 static void
 549 network_pex_recv_update_response(struct network *net, const uint8_t *data, size_t len,
 550                               struct sockaddr_in6 *addr, enum pex_opcode op)
 551 {
 552         struct network_peer *peer;
 553         void *net_data;
 554         int net_data_len = 0;
 555         uint64_t version = 0;
 556         bool no_prev_data = !net->net_data_len;
 557
 558         if (net->config.type != NETWORK_TYPE_DYNAMIC)
 559                 return;
 560
 561         net_data = pex_msg_update_response_recv(data, len, op, &net_data_len, &version);
 562         if (!net_data)
 563                 return;
 564
 565         if (version <= net->net_data_version) {
 566                 free(net_data);
 567                 return;
 568         }
 569
 570         D_NET(net, "received updated network data, len=%d", net_data_len);
 571         free(net->net_data);
 572
 573         net->net_data = net_data;
 574         net->net_data_len = net_data_len;
 575         net->net_data_version = version;
 576         if (network_save_dynamic(net) < 0)
 577                 return;
 578
 579         uloop_timeout_set(&net->reload_timer, no_prev_data ? 1 : UNETD_DATA_UPDATE_DELAY);
 580         vlist_for_each_element(&net->peers, peer, node) {
 581                 if (!peer->state.connected || !peer->pex_port)
 582                         continue;
 583                 network_pex_send_update_request(net, peer, NULL);
 584         }
 585 }
 586
 587 static void
 588 network_pex_recv(struct network *net, struct network_peer *peer, struct pex_hdr *hdr)
 589 {
 590         const void *data = hdr + 1;
 591
 592         if (hdr->version != 0)
 593                 return;
 594
 595         D_PEER(net, peer, "PEX rx op=%d", hdr->opcode);
 596         switch (hdr->opcode) {
 597         case PEX_MSG_HELLO:
 598                 network_pex_recv_hello(net, peer, data, hdr->len);
 599                 break;
 600         case PEX_MSG_NOTIFY_PEERS:
 601                 network_pex_recv_peers(net, peer, data, hdr->len);
 602                 break;
 603         case PEX_MSG_QUERY:
 604                 network_pex_recv_query(net, peer, data, hdr->len);
 605                 break;
 606         case PEX_MSG_PING:
 607                 network_pex_recv_ping(net, peer);
 608                 break;
 609         case PEX_MSG_PONG:
 610                 break;
 611         case PEX_MSG_UPDATE_REQUEST:
 612                 network_pex_recv_update_request(net, peer, data, hdr->len,
 613                                                 NULL);
 614                 break;
 615         case PEX_MSG_UPDATE_RESPONSE:
 616         case PEX_MSG_UPDATE_RESPONSE_DATA:
 617         case PEX_MSG_UPDATE_RESPONSE_NO_DATA:
 618                 network_pex_recv_update_response(net, data, hdr->len,
 619                                               NULL, hdr->opcode);
 620                 break;
 621         case PEX_MSG_ENDPOINT_NOTIFY:
 622                 break;
 623         }
 624 }
 625
 626 static void
 627 network_pex_fd_cb(struct uloop_fd *fd, unsigned int events)
 628 {
 629         struct network *net = container_of(fd, struct network, pex.fd);
 630         struct network_peer *local = &net->net_config.local_host->peer;
 631         struct network_peer *peer;
 632         struct sockaddr_in6 sin6;
 633         static char buf[PEX_BUF_SIZE];
 634         struct pex_hdr *hdr = (struct pex_hdr *)buf;
 635         ssize_t len;
 636
 637         while (1) {
 638                 socklen_t slen = sizeof(sin6);
 639
 640                 len = recvfrom(fd->fd, buf, sizeof(buf), 0, (struct sockaddr *)&sin6, &slen);
 641                 if (len < 0) {
 642                         if (errno == EINTR)
 643                                 continue;
 644
 645                         if (errno == EAGAIN)
 646                                 break;
 647
 648                         D_NET(net, "recvfrom failed: %s", strerror(errno));
 649                         network_pex_close(net);
 650                         return;
 651                 }
 652
 653                 if (!len)
 654                         continue;
 655
 656                 if (len < sizeof(*hdr))
 657                         continue;
 658
 659                 hdr->len = ntohs(hdr->len);
 660                 if (len - sizeof(hdr) < hdr->len)
 661                         continue;
 662
 663                 peer = pex_msg_peer(net, hdr->id);
 664                 if (!peer)
 665                         continue;
 666
 667                 if (memcmp(&sin6.sin6_addr, &peer->local_addr.in6, sizeof(sin6.sin6_addr)) != 0)
 668                         continue;
 669
 670                 if (peer == local)
 671                         continue;
 672
 673                 network_pex_recv(net, peer, hdr);
 674         }
 675 }
 676
 677 void network_pex_create_host(struct network *net, union network_endpoint *ep,
 678                              unsigned int timeout)
 679 {
 680         struct network_pex *pex = &net->pex;
 681         struct network_pex_host *host;
 682         bool new_host = false;
 683
 684         list_for_each_entry(host, &pex->hosts, list) {
 685                 if (memcmp(&host->endpoint, ep, sizeof(host->endpoint)) != 0)
 686                         continue;
 687
 688                 list_move_tail(&host->list, &pex->hosts);
 689                 goto out;
 690         }
 691
 692         host = calloc(1, sizeof(*host));
 693         new_host = true;
 694         memcpy(&host->endpoint, ep, sizeof(host->endpoint));
 695         list_add_tail(&host->list, &pex->hosts);
 696
 697 out:
 698         if (timeout && (new_host || host->timeout))
 699                 host->timeout = timeout + unet_gettime();
 700         network_pex_host_request_update(net, host);
 701 }
 702
 703 static void
 704 network_pex_open_auth_connect(struct network *net)
 705 {
 706         struct network_pex *pex = &net->pex;
 707         struct network_peer *peer;
 708         struct blob_attr *cur;
 709         int rem;
 710
 711         if (net->config.type != NETWORK_TYPE_DYNAMIC)
 712                 return;
 713
 714         uloop_timeout_set(&pex->request_update_timer, 5000);
 715
 716         vlist_for_each_element(&net->peers, peer, node) {
 717                 union network_endpoint ep = {};
 718
 719                 if (!peer->endpoint || peer->dynamic)
 720                         continue;
 721
 722                 if (network_get_endpoint(&ep, peer->endpoint,
 723                                          UNETD_GLOBAL_PEX_PORT, 0) < 0)
 724                         continue;
 725
 726                 ep.in.sin_port = htons(UNETD_GLOBAL_PEX_PORT);
 727                 network_pex_create_host(net, &ep, 0);
 728         }
 729
 730         if (!net->config.auth_connect)
 731                 return;
 732
 733         blobmsg_for_each_attr(cur, net->config.auth_connect, rem) {
 734                 union network_endpoint ep = {};
 735
 736                 if (network_get_endpoint(&ep, blobmsg_get_string(cur),
 737                                          UNETD_GLOBAL_PEX_PORT, 0) < 0)
 738                         continue;
 739
 740                 network_pex_create_host(net, &ep, 0);
 741         }
 742 }
 743
 744
 745 int network_pex_open(struct network *net)
 746 {
 747         struct network_host *local_host = net->net_config.local_host;
 748         struct network_peer *local;
 749         struct network_pex *pex = &net->pex;
 750         struct sockaddr_in6 sin6 = {};
 751         int yes = 1;
 752         int fd;
 753
 754         network_pex_open_auth_connect(net);
 755
 756         if (!local_host || !local_host->peer.pex_port)
 757                 return 0;
 758
 759         local = &local_host->peer;
 760         fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
 761         if (fd < 0)
 762                 return -1;
 763
 764         fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
 765         fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
 766
 767         sin6.sin6_family = AF_INET6;
 768         memcpy(&sin6.sin6_addr, &local->local_addr.in6,
 769                sizeof(local->local_addr.in6));
 770         sin6.sin6_port = htons(local_host->peer.pex_port);
 771
 772         if (bind(fd, (struct sockaddr *)&sin6, sizeof(sin6)) < 0) {
 773                 perror("bind");
 774                 goto close;
 775         }
 776
 777         setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
 778         setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &yes, sizeof(yes));
 779 #ifdef linux
 780         setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
 781                    network_name(net), strlen(network_name(net)));
 782 #endif
 783
 784         pex->fd.fd = fd;
 785         pex->fd.cb = network_pex_fd_cb;
 786         uloop_fd_add(&pex->fd, ULOOP_READ);
 787
 788         return 0;
 789
 790 close:
 791         close(fd);
 792         return -1;
 793 }
 794
 795 void network_pex_close(struct network *net)
 796 {
 797         struct network_pex *pex = &net->pex;
 798         struct network_pex_host *host, *tmp;
 799
 800         uloop_timeout_cancel(&pex->request_update_timer);
 801         list_for_each_entry_safe(host, tmp, &pex->hosts, list) {
 802                 if (host->timeout)
 803                         continue;
 804
 805                 list_del(&host->list);
 806                 free(host);
 807         }
 808
 809         if (pex->fd.fd < 0)
 810                 return;
 811
 812         uloop_fd_delete(&pex->fd);
 813         close(pex->fd.fd);
 814         network_pex_init(net);
 815 }
 816
 817 void network_pex_free(struct network *net)
 818 {
 819         struct network_pex *pex = &net->pex;
 820         struct network_pex_host *host, *tmp;
 821
 822         list_for_each_entry_safe(host, tmp, &pex->hosts, list) {
 823                 list_del(&host->list);
 824                 free(host);
 825         }
 826 }
 827
 828 static struct network *
 829 global_pex_find_network(const uint8_t *id)
 830 {
 831         struct network *net;
 832
 833         avl_for_each_element(&networks, net, node) {
 834                 if (!memcmp(id, net->config.auth_key, PEX_ID_LEN))
 835                         return net;
 836         }
 837
 838         return NULL;
 839 }
 840
 841 static void
 842 global_pex_recv(struct pex_hdr *hdr, struct sockaddr_in6 *addr)
 843 {
 844         struct pex_ext_hdr *ehdr = (void *)(hdr + 1);
 845         struct network_peer *peer;
 846         struct network *net;
 847         void *data = (void *)(ehdr + 1);
 848         char buf[INET6_ADDRSTRLEN];
 849         int addr_len;
 850
 851         if (hdr->version != 0)
 852                 return;
 853
 854         net = global_pex_find_network(ehdr->auth_id);
 855         if (!net || net->config.type != NETWORK_TYPE_DYNAMIC)
 856                 return;
 857
 858         *(uint64_t *)hdr->id ^= pex_network_hash(net->config.auth_key, ehdr->nonce);
 859
 860         D("PEX global rx op=%d", hdr->opcode);
 861         switch (hdr->opcode) {
 862         case PEX_MSG_HELLO:
 863         case PEX_MSG_NOTIFY_PEERS:
 864         case PEX_MSG_QUERY:
 865         case PEX_MSG_PING:
 866         case PEX_MSG_PONG:
 867                 break;
 868         case PEX_MSG_UPDATE_REQUEST:
 869                 peer = pex_msg_peer(net, hdr->id);
 870                 network_pex_recv_update_request(net, peer, data, hdr->len,
 871                                                 addr);
 872                 break;
 873         case PEX_MSG_UPDATE_RESPONSE:
 874         case PEX_MSG_UPDATE_RESPONSE_DATA:
 875         case PEX_MSG_UPDATE_RESPONSE_NO_DATA:
 876                 network_pex_recv_update_response(net, data, hdr->len, addr, hdr->opcode);
 877                 break;
 878         case PEX_MSG_ENDPOINT_NOTIFY:
 879                 peer = pex_msg_peer(net, hdr->id);
 880                 if (!peer)
 881                         break;
 882
 883                 if (IN6_IS_ADDR_V4MAPPED(&addr->sin6_addr)) {
 884                         struct sockaddr_in *sin = (struct sockaddr_in *)addr;
 885                         struct in_addr in = *(struct in_addr *)&addr->sin6_addr.s6_addr[12];
 886                         int port = addr->sin6_port;
 887
 888                         memset(addr, 0, sizeof(*addr));
 889                         sin->sin_port = port;
 890                         sin->sin_family = AF_INET;
 891                         sin->sin_addr = in;
 892                 }
 893
 894                 D_PEER(net, peer, "receive endpoint notification from %s",
 895                   inet_ntop(addr->sin6_family, network_endpoint_addr((void *)addr, &addr_len),
 896                             buf, sizeof(buf)));
 897
 898                 memcpy(&peer->state.next_endpoint, addr, sizeof(*addr));
 899                 break;
 900         }
 901 }
 902
 903 int global_pex_open(void)
 904 {
 905         struct sockaddr_in6 sin6 = {};
 906
 907         sin6.sin6_family = AF_INET6;
 908         sin6.sin6_port = htons(global_pex_port);
 909
 910         return pex_open(&sin6, sizeof(sin6), global_pex_recv, true);
 911 }