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_request_update_cb(struct uloop_timeout *t)
 284 {
 285         struct network *net = container_of(t, struct network, pex.request_update_timer);
 286         struct network_pex *pex = &net->pex;
 287         struct network_pex_host *host, *tmp;
 288         uint64_t now = unet_gettime();
 289
 290         uloop_timeout_set(t, 500);
 291
 292         if (list_empty(&pex->hosts))
 293                 return;
 294
 295         list_for_each_entry_safe(host, tmp, &pex->hosts, list) {
 296                 if (host->timeout && host->timeout < now) {
 297                         list_del(&host->list);
 298                         free(host);
 299                         continue;
 300                 }
 301
 302                 if (host->last_ping + 10 >= now)
 303                         continue;
 304
 305                 list_move_tail(&host->list, &pex->hosts);
 306                 network_pex_host_request_update(net, host);
 307         }
 308 }
 309
 310 void network_pex_init(struct network *net)
 311 {
 312         struct network_pex *pex = &net->pex;
 313
 314         memset(pex, 0, sizeof(*pex));
 315         pex->fd.fd = -1;
 316         INIT_LIST_HEAD(&pex->hosts);
 317         pex->request_update_timer.cb = network_pex_request_update_cb;
 318 }
 319
 320 static void
 321 network_pex_query_hosts(struct network *net)
 322 {
 323         struct network_host *host;
 324         int rv = rand();
 325         int hosts = 0;
 326         int i;
 327
 328         pex_msg_init(net, PEX_MSG_QUERY);
 329
 330         avl_for_each_element(&net->hosts, host, node) {
 331                 struct network_peer *peer = &host->peer;
 332                 void *id;
 333
 334                 if ((net->stun.port_ext && host == net->net_config.local_host) ||
 335                     peer->state.connected || peer->endpoint)
 336                         continue;
 337
 338                 id = pex_msg_append(PEX_ID_LEN);
 339                 if (!id)
 340                         break;
 341
 342                 memcpy(id, peer->key, PEX_ID_LEN);
 343                 hosts++;
 344         }
 345
 346         if (!hosts)
 347                 return;
 348
 349         rv %= net->hosts.count;
 350         for (i = 0; i < 2; i++) {
 351                 avl_for_each_element(&net->hosts, host, node) {
 352                         struct network_peer *peer = &host->peer;
 353
 354                         if (rv > 0) {
 355                                 rv--;
 356                                 continue;
 357                         }
 358
 359                         if (host == net->net_config.local_host)
 360                                 continue;
 361
 362                         if (!peer->state.connected)
 363                                 continue;
 364
 365                         D_PEER(net, peer, "send query for %d hosts", hosts);
 366                         pex_msg_send(net, peer);
 367                         return;
 368                 }
 369         }
 370
 371 }
 372
 373 static void
 374 network_pex_send_ping(struct network *net, struct network_peer *peer)
 375 {
 376         if (peer->state.pinged || !peer->state.endpoint.sa.sa_family)
 377                 return;
 378
 379         pex_msg_init(net, PEX_MSG_PING);
 380         pex_msg_send(net, peer);
 381         peer->state.pinged = true;
 382 }
 383
 384 static void
 385 network_pex_send_update_request(struct network *net, struct network_peer *peer,
 386                                 struct sockaddr_in6 *addr)
 387 {
 388         union network_endpoint ep = {};
 389         uint64_t version = 0;
 390
 391         if (addr)
 392                 memcpy(&ep.in6, addr, sizeof(ep.in6));
 393         else
 394                 pex_get_peer_addr(&ep.in6, net, peer);
 395
 396         if (net->net_data_len)
 397                 version = net->net_data_version;
 398
 399         if (!pex_msg_update_request_init(net->config.pubkey, net->config.key,
 400                                          net->config.auth_key, &ep,
 401                                          version, !!addr))
 402                 return;
 403
 404         pex_msg_send_ext(net, peer, addr);
 405 }
 406
 407 void network_pex_event(struct network *net, struct network_peer *peer,
 408                        enum pex_event ev)
 409 {
 410         if (!network_pex_active(&net->pex))
 411                 return;
 412
 413         switch (ev) {
 414         case PEX_EV_HANDSHAKE:
 415                 pex_send_hello(net, peer);
 416                 if (net->config.type == NETWORK_TYPE_DYNAMIC)
 417                         network_pex_send_update_request(net, peer, NULL);
 418                 break;
 419         case PEX_EV_ENDPOINT_CHANGE:
 420                 network_pex_handle_endpoint_change(net, peer);
 421                 break;
 422         case PEX_EV_QUERY:
 423                 network_pex_query_hosts(net);
 424                 break;
 425         case PEX_EV_PING:
 426                 network_pex_send_ping(net, peer);
 427                 break;
 428         }
 429 }
 430
 431 static void
 432 network_pex_recv_hello(struct network *net, struct network_peer *peer,
 433                        const struct pex_hello *data, size_t len)
 434 {
 435         char addrstr[INET6_ADDRSTRLEN];
 436         uint16_t flags;
 437         int af;
 438
 439         if (len < sizeof(*data))
 440                 return;
 441
 442         if (peer->state.has_local_ep_addr &&
 443             !memcmp(&peer->state.local_ep_addr, data->local_addr, sizeof(data->local_addr)))
 444                 return;
 445
 446         flags = ntohs(data->flags);
 447         af = (flags & PEER_EP_F_IPV6) ? AF_INET6 : AF_INET;
 448         D_PEER(net, peer, "set local endpoint address to %s",
 449                inet_ntop(af, data->local_addr, addrstr, sizeof(addrstr)));
 450         peer->state.has_local_ep_addr = true;
 451         memcpy(&peer->state.local_ep_addr, data->local_addr, sizeof(data->local_addr));
 452 }
 453
 454 static void
 455 network_pex_recv_peers(struct network *net, struct network_peer *peer,
 456                        const struct pex_peer_endpoint *data, size_t len)
 457 {
 458         struct network_peer *local = &net->net_config.local_host->peer;
 459         struct network_peer *cur;
 460
 461         for (; len >= sizeof(*data); len -= sizeof(*data), data++) {
 462                 union network_endpoint *ep;
 463                 uint16_t flags;
 464                 void *addr;
 465                 int len;
 466
 467                 if (!memcmp(data->peer_id, &local->key, PEX_ID_LEN)) {
 468                         network_stun_update_port(net, false, ntohs(data->port));
 469                         continue;
 470                 }
 471
 472                 cur = pex_msg_peer(net, data->peer_id);
 473                 if (!cur || cur == peer)
 474                         continue;
 475
 476                 D_PEER(net, peer, "received peer address for %s",
 477                        network_peer_name(cur));
 478                 flags = ntohs(data->flags);
 479                 ep = &cur->state.next_endpoint;
 480                 ep->sa.sa_family = (flags & PEER_EP_F_IPV6) ? AF_INET6 : AF_INET;
 481                 addr = network_endpoint_addr(ep, &len);
 482                 memcpy(addr, data->addr, len);
 483                 ep->in.sin_port = data->port;
 484         }
 485 }
 486
 487 static void
 488 network_pex_recv_query(struct network *net, struct network_peer *peer,
 489                        const uint8_t *data, size_t len)
 490 {
 491         struct network_peer *cur;
 492         int resp = 0;
 493
 494         pex_msg_init(net, PEX_MSG_NOTIFY_PEERS);
 495         for (; len >= 8; data += 8, len -= 8) {
 496                 cur = pex_msg_peer(net, data);
 497                 if (!cur || !cur->state.connected)
 498                         continue;
 499
 500                 if (!pex_msg_add_peer_endpoint(net, cur, peer))
 501                         resp++;
 502         }
 503
 504         if (!resp)
 505                 return;
 506
 507         D_PEER(net, peer, "send query response with %d hosts", resp);
 508         pex_msg_send(net, peer);
 509 }
 510
 511 static void
 512 network_pex_recv_ping(struct network *net, struct network_peer *peer)
 513 {
 514         time_t now = time(NULL);
 515
 516         if (peer->state.last_request == now)
 517                 return;
 518
 519         peer->state.last_request = now;
 520         pex_msg_init(net, PEX_MSG_PONG);
 521         pex_msg_send(net, peer);
 522 }
 523
 524 static void
 525 network_pex_recv_update_request(struct network *net, struct network_peer *peer,
 526                                 const uint8_t *data, size_t len,
 527                                 struct sockaddr_in6 *addr)
 528 {
 529         struct pex_update_request *req = (struct pex_update_request *)data;
 530         struct pex_msg_update_send_ctx ctx = {};
 531         uint64_t req_version = be64_to_cpu(req->cur_version);
 532         int *query_count;
 533         bool done = false;
 534
 535         if (len < sizeof(struct pex_update_request))
 536                 return;
 537
 538         if (net->config.type != NETWORK_TYPE_DYNAMIC)
 539                 return;
 540
 541         if (peer)
 542                 query_count = &peer->state.num_net_queries;
 543         else
 544                 query_count = &net->num_net_queries;
 545
 546         if (++*query_count > 10)
 547                 return;
 548
 549         D("receive update request, local version=%"PRIu64", remote version=%"PRIu64, net->net_data_version, req_version);
 550
 551         if (req_version >= net->net_data_version) {
 552                 struct pex_update_response_no_data *res;
 553
 554                 pex_msg_init_ext(net, PEX_MSG_UPDATE_RESPONSE_NO_DATA, !!addr);
 555                 res = pex_msg_append(sizeof(*res));
 556                 res->req_id = req->req_id;
 557                 res->cur_version = cpu_to_be64(net->net_data_version);
 558                 pex_msg_send_ext(net, peer, addr);
 559         }
 560
 561         if (req_version > net->net_data_version)
 562                 network_pex_send_update_request(net, peer, addr);
 563
 564         if (!peer || !net->net_data_len)
 565                 return;
 566
 567         if (req_version >= net->net_data_version)
 568                 return;
 569
 570         pex_msg_update_response_init(&ctx, net->config.pubkey, net->config.auth_key,
 571                                      peer->key, !!addr, (void *)data,
 572                                      net->net_data, net->net_data_len);
 573         while (!done) {
 574                 pex_msg_send_ext(net, peer, addr);
 575                 done = !pex_msg_update_response_continue(&ctx);
 576         }
 577 }
 578
 579 static void
 580 network_pex_recv_update_response(struct network *net, const uint8_t *data, size_t len,
 581                               struct sockaddr_in6 *addr, enum pex_opcode op)
 582 {
 583         struct network_peer *peer;
 584         void *net_data;
 585         int net_data_len = 0;
 586         uint64_t version = 0;
 587         bool no_prev_data = !net->net_data_len;
 588
 589         if (net->config.type != NETWORK_TYPE_DYNAMIC)
 590                 return;
 591
 592         net_data = pex_msg_update_response_recv(data, len, op, &net_data_len, &version);
 593         if (!net_data)
 594                 return;
 595
 596         if (version <= net->net_data_version) {
 597                 free(net_data);
 598                 return;
 599         }
 600
 601         D_NET(net, "received updated network data, len=%d", net_data_len);
 602         free(net->net_data);
 603
 604         net->net_data = net_data;
 605         net->net_data_len = net_data_len;
 606         net->net_data_version = version;
 607         if (network_save_dynamic(net) < 0)
 608                 return;
 609
 610         uloop_timeout_set(&net->reload_timer, no_prev_data ? 1 : UNETD_DATA_UPDATE_DELAY);
 611         vlist_for_each_element(&net->peers, peer, node) {
 612                 if (!peer->state.connected || !peer->pex_port)
 613                         continue;
 614                 network_pex_send_update_request(net, peer, NULL);
 615         }
 616 }
 617
 618 static void
 619 network_pex_recv(struct network *net, struct network_peer *peer, struct pex_hdr *hdr)
 620 {
 621         const void *data = hdr + 1;
 622
 623         if (hdr->version != 0)
 624                 return;
 625
 626         D_PEER(net, peer, "PEX rx op=%d", hdr->opcode);
 627         switch (hdr->opcode) {
 628         case PEX_MSG_HELLO:
 629                 network_pex_recv_hello(net, peer, data, hdr->len);
 630                 break;
 631         case PEX_MSG_NOTIFY_PEERS:
 632                 network_pex_recv_peers(net, peer, data, hdr->len);
 633                 break;
 634         case PEX_MSG_QUERY:
 635                 network_pex_recv_query(net, peer, data, hdr->len);
 636                 break;
 637         case PEX_MSG_PING:
 638                 network_pex_recv_ping(net, peer);
 639                 break;
 640         case PEX_MSG_PONG:
 641                 break;
 642         case PEX_MSG_UPDATE_REQUEST:
 643                 network_pex_recv_update_request(net, peer, data, hdr->len,
 644                                                 NULL);
 645                 break;
 646         case PEX_MSG_UPDATE_RESPONSE:
 647         case PEX_MSG_UPDATE_RESPONSE_DATA:
 648         case PEX_MSG_UPDATE_RESPONSE_NO_DATA:
 649                 network_pex_recv_update_response(net, data, hdr->len,
 650                                               NULL, hdr->opcode);
 651                 break;
 652         case PEX_MSG_ENDPOINT_NOTIFY:
 653                 break;
 654         }
 655 }
 656
 657 static void
 658 network_pex_fd_cb(struct uloop_fd *fd, unsigned int events)
 659 {
 660         struct network *net = container_of(fd, struct network, pex.fd);
 661         struct network_peer *local = &net->net_config.local_host->peer;
 662         struct network_peer *peer;
 663         struct sockaddr_in6 sin6;
 664         static char buf[PEX_BUF_SIZE];
 665         struct pex_hdr *hdr = (struct pex_hdr *)buf;
 666         ssize_t len;
 667
 668         while (1) {
 669                 socklen_t slen = sizeof(sin6);
 670
 671                 len = recvfrom(fd->fd, buf, sizeof(buf), 0, (struct sockaddr *)&sin6, &slen);
 672                 if (len < 0) {
 673                         if (errno == EINTR)
 674                                 continue;
 675
 676                         if (errno == EAGAIN)
 677                                 break;
 678
 679                         D_NET(net, "recvfrom failed: %s", strerror(errno));
 680                         network_pex_close(net);
 681                         return;
 682                 }
 683
 684                 if (!len)
 685                         continue;
 686
 687                 hdr = pex_rx_accept(buf, len, false);
 688                 if (!hdr)
 689                         continue;
 690
 691                 peer = pex_msg_peer(net, hdr->id);
 692                 if (!peer)
 693                         continue;
 694
 695                 if (memcmp(&sin6.sin6_addr, &peer->local_addr.in6, sizeof(sin6.sin6_addr)) != 0)
 696                         continue;
 697
 698                 if (peer == local)
 699                         continue;
 700
 701                 network_pex_recv(net, peer, hdr);
 702         }
 703 }
 704
 705 void network_pex_create_host(struct network *net, union network_endpoint *ep,
 706                              unsigned int timeout)
 707 {
 708         struct network_pex *pex = &net->pex;
 709         struct network_pex_host *host;
 710         uint64_t now = unet_gettime();
 711         bool new_host = false;
 712
 713         list_for_each_entry(host, &pex->hosts, list) {
 714                 if (memcmp(&host->endpoint, ep, sizeof(host->endpoint)) != 0)
 715                         continue;
 716
 717                 if (host->last_ping + 10 < now) {
 718                         list_move_tail(&host->list, &pex->hosts);
 719                         network_pex_host_request_update(net, host);
 720                 }
 721                 goto out;
 722         }
 723
 724         host = calloc(1, sizeof(*host));
 725         new_host = true;
 726         memcpy(&host->endpoint, ep, sizeof(host->endpoint));
 727         list_add_tail(&host->list, &pex->hosts);
 728
 729 out:
 730         if (timeout && (new_host || host->timeout))
 731                 host->timeout = timeout + unet_gettime();
 732 }
 733
 734 static void
 735 network_pex_open_auth_connect(struct network *net)
 736 {
 737         struct network_pex *pex = &net->pex;
 738         struct network_peer *peer;
 739         struct blob_attr *cur;
 740         int rem;
 741
 742         if (net->config.type != NETWORK_TYPE_DYNAMIC)
 743                 return;
 744
 745         uloop_timeout_set(&pex->request_update_timer, 5000);
 746
 747         vlist_for_each_element(&net->peers, peer, node) {
 748                 union network_endpoint ep = {};
 749
 750                 if (!peer->endpoint || peer->dynamic)
 751                         continue;
 752
 753                 if (network_get_endpoint(&ep, AF_UNSPEC, peer->endpoint,
 754                                          UNETD_GLOBAL_PEX_PORT, 0) < 0)
 755                         continue;
 756
 757                 ep.in.sin_port = htons(UNETD_GLOBAL_PEX_PORT);
 758                 network_pex_create_host(net, &ep, 0);
 759         }
 760
 761         if (!net->config.auth_connect)
 762                 return;
 763
 764         blobmsg_for_each_attr(cur, net->config.auth_connect, rem) {
 765                 union network_endpoint ep = {};
 766
 767                 if (network_get_endpoint(&ep, AF_UNSPEC, blobmsg_get_string(cur),
 768                                          UNETD_GLOBAL_PEX_PORT, 0) < 0)
 769                         continue;
 770
 771                 network_pex_create_host(net, &ep, 0);
 772         }
 773 }
 774
 775
 776 int network_pex_open(struct network *net)
 777 {
 778         struct network_host *local_host = net->net_config.local_host;
 779         struct network_peer *local;
 780         struct network_pex *pex = &net->pex;
 781         struct sockaddr_in6 sin6 = {};
 782         int yes = 1;
 783         int fd;
 784
 785         network_pex_open_auth_connect(net);
 786
 787         if (!local_host || !local_host->peer.pex_port)
 788                 return 0;
 789
 790         local = &local_host->peer;
 791         fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
 792         if (fd < 0)
 793                 return -1;
 794
 795         fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
 796         fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
 797
 798         sin6.sin6_family = AF_INET6;
 799         memcpy(&sin6.sin6_addr, &local->local_addr.in6,
 800                sizeof(local->local_addr.in6));
 801         sin6.sin6_port = htons(local_host->peer.pex_port);
 802
 803         if (bind(fd, (struct sockaddr *)&sin6, sizeof(sin6)) < 0) {
 804                 perror("bind");
 805                 goto close;
 806         }
 807
 808         setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
 809         setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &yes, sizeof(yes));
 810 #ifdef linux
 811         setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
 812                    network_name(net), strlen(network_name(net)));
 813 #endif
 814
 815         pex->fd.fd = fd;
 816         pex->fd.cb = network_pex_fd_cb;
 817         uloop_fd_add(&pex->fd, ULOOP_READ);
 818
 819         return 0;
 820
 821 close:
 822         close(fd);
 823         return -1;
 824 }
 825
 826 void network_pex_close(struct network *net)
 827 {
 828         struct network_pex *pex = &net->pex;
 829         struct network_pex_host *host, *tmp;
 830         uint64_t now = unet_gettime();
 831
 832         uloop_timeout_cancel(&pex->request_update_timer);
 833         list_for_each_entry_safe(host, tmp, &pex->hosts, list) {
 834                 if (host->timeout)
 835                         continue;
 836
 837                 if (host->last_active + UNETD_PEX_HOST_ACITVE_TIMEOUT >= now)
 838                         continue;
 839
 840                 list_del(&host->list);
 841                 free(host);
 842         }
 843
 844         if (pex->fd.fd < 0)
 845                 return;
 846
 847         uloop_fd_delete(&pex->fd);
 848         close(pex->fd.fd);
 849         network_pex_init(net);
 850 }
 851
 852 void network_pex_free(struct network *net)
 853 {
 854         struct network_pex *pex = &net->pex;
 855         struct network_pex_host *host, *tmp;
 856
 857         list_for_each_entry_safe(host, tmp, &pex->hosts, list) {
 858                 list_del(&host->list);
 859                 free(host);
 860         }
 861 }
 862
 863 static struct network *
 864 global_pex_find_network(const uint8_t *id)
 865 {
 866         struct network *net;
 867
 868         avl_for_each_element(&networks, net, node) {
 869                 if (!memcmp(id, net->config.auth_key, PEX_ID_LEN))
 870                         return net;
 871         }
 872
 873         return NULL;
 874 }
 875
 876 static void
 877 global_pex_set_active(struct network *net, struct sockaddr_in6 *addr)
 878 {
 879         struct network_pex *pex = &net->pex;
 880         struct network_pex_host *host;
 881
 882         list_for_each_entry(host, &pex->hosts, list) {
 883                 if (memcmp(&host->endpoint.in6, addr, sizeof(*addr)) != 0)
 884                         continue;
 885
 886                 host->last_active = unet_gettime();
 887         }
 888 }
 889
 890 static void
 891 global_pex_recv(void *msg, size_t msg_len, struct sockaddr_in6 *addr)
 892 {
 893         struct pex_hdr *hdr;
 894         struct pex_ext_hdr *ehdr;
 895         struct network_peer *peer;
 896         struct network *net;
 897         char buf[INET6_ADDRSTRLEN];
 898         void *data;
 899         int addr_len;
 900
 901         if (stun_msg_is_valid(msg, msg_len)) {
 902                 avl_for_each_element(&networks, net, node)
 903                         network_stun_rx_packet(net, msg, msg_len);
 904         }
 905
 906         hdr = pex_rx_accept(msg, msg_len, true);
 907         if (!hdr)
 908                 return;
 909
 910         ehdr = (void *)(hdr + 1);
 911         data = (void *)(ehdr + 1);
 912
 913         if (hdr->version != 0)
 914                 return;
 915
 916         net = global_pex_find_network(ehdr->auth_id);
 917         if (!net || net->config.type != NETWORK_TYPE_DYNAMIC)
 918                 return;
 919
 920         *(uint64_t *)hdr->id ^= pex_network_hash(net->config.auth_key, ehdr->nonce);
 921
 922         global_pex_set_active(net, addr);
 923
 924         D("PEX global rx op=%d", hdr->opcode);
 925         switch (hdr->opcode) {
 926         case PEX_MSG_HELLO:
 927         case PEX_MSG_NOTIFY_PEERS:
 928         case PEX_MSG_QUERY:
 929         case PEX_MSG_PING:
 930         case PEX_MSG_PONG:
 931                 break;
 932         case PEX_MSG_UPDATE_REQUEST:
 933                 peer = pex_msg_peer(net, hdr->id);
 934                 network_pex_recv_update_request(net, peer, data, hdr->len,
 935                                                 addr);
 936                 break;
 937         case PEX_MSG_UPDATE_RESPONSE:
 938         case PEX_MSG_UPDATE_RESPONSE_DATA:
 939         case PEX_MSG_UPDATE_RESPONSE_NO_DATA:
 940                 network_pex_recv_update_response(net, data, hdr->len, addr, hdr->opcode);
 941                 break;
 942         case PEX_MSG_ENDPOINT_PORT_NOTIFY:
 943                 if (hdr->len < sizeof(struct pex_endpoint_port_notify))
 944                         break;
 945         case PEX_MSG_ENDPOINT_NOTIFY:
 946                 peer = pex_msg_peer(net, hdr->id);
 947                 if (!peer)
 948                         break;
 949
 950                 D_PEER(net, peer, "receive endpoint notification from %s",
 951                   inet_ntop(addr->sin6_family, network_endpoint_addr((void *)addr, &addr_len),
 952                             buf, sizeof(buf)));
 953
 954                 memcpy(&peer->state.next_endpoint, addr, sizeof(*addr));
 955                 if (hdr->opcode == PEX_MSG_ENDPOINT_PORT_NOTIFY) {
 956                         struct pex_endpoint_port_notify *port = data;
 957
 958                         peer->state.next_endpoint.in.sin_port = port->port;
 959                 }
 960                 break;
 961         }
 962 }
 963
 964 static void
 965 pex_recv_control(struct pex_msg_local_control *msg, int len)
 966 {
 967         struct network *net;
 968
 969         if (msg->msg_type != 0)
 970                 return;
 971
 972         net = global_pex_find_network(msg->auth_id);
 973         if (!net)
 974                 return;
 975
 976         if (!msg->timeout)
 977                 msg->timeout = 60;
 978         network_pex_create_host(net, &msg->ep, msg->timeout);
 979 }
 980
 981 int global_pex_open(const char *unix_path)
 982 {
 983         struct sockaddr_in6 sin6 = {};
 984         int ret;
 985
 986         sin6.sin6_family = AF_INET6;
 987         sin6.sin6_port = htons(global_pex_port);
 988
 989         ret = pex_open(&sin6, sizeof(sin6), global_pex_recv, true);
 990
 991         if (unix_path)
 992                 pex_unix_open(unix_path, pex_recv_control);
 993
 994         return ret;
 995 }