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