remote.c

   1 /*
   2  *   This program is free software; you can redistribute it and/or modify
   3  *   it under the terms of the GNU General Public License as published by
   4  *   the Free Software Foundation; either version 2 of the License.
   5  *
   6  *   This program is distributed in the hope that it will be useful,
   7  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  *   GNU General Public License for more details.
  10  *
  11  *   You should have received a copy of the GNU General Public License
  12  *   along with this program; if not, write to the Free Software
  13  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
  14  *
  15  *   Copyright (C) 2020 embedd.ch
  16  *   Copyright (C) 2020 Felix Fietkau <nbd@nbd.name>
  17  *   Copyright (C) 2020 John Crispin <john@phrozen.org>
  18  */
  19
  20 #include <sys/types.h>
  21 #include <sys/socket.h>
  22 #include <netinet/in.h>
  23 #include <net/if.h>
  24 #include <arpa/inet.h>
  25 #include <errno.h>
  26 #include <unistd.h>
  27
  28 #include <libubox/vlist.h>
  29 #include <libubox/avl-cmp.h>
  30 #include <libubox/usock.h>
  31 #include "usteer.h"
  32 #include "remote.h"
  33 #include "node.h"
  34
  35 static uint32_t local_id;
  36 static struct uloop_fd remote_fd;
  37 static struct uloop_timeout remote_timer;
  38 static struct uloop_timeout reload_timer;
  39
  40 static struct blob_buf buf;
  41 static uint32_t msg_seq;
  42
  43 struct interface {
  44         struct vlist_node node;
  45         int ifindex;
  46 };
  47
  48 static void
  49 interfaces_update_cb(struct vlist_tree *tree,
  50                      struct vlist_node *node_new,
  51                      struct vlist_node *node_old);
  52
  53 static int remote_host_cmp(const void *k1, const void *k2, void *ptr)
  54 {
  55         unsigned long v1 = (unsigned long) k1;
  56         unsigned long v2 = (unsigned long) k2;
  57
  58         return v2 - v1;
  59 }
  60
  61 static VLIST_TREE(interfaces, avl_strcmp, interfaces_update_cb, true, true);
  62 LIST_HEAD(remote_nodes);
  63 static AVL_TREE(remote_hosts, remote_host_cmp, false, NULL);
  64
  65 static const char *
  66 interface_name(struct interface *iface)
  67 {
  68         return iface->node.avl.key;
  69 }
  70
  71 static void
  72 interface_check(struct interface *iface)
  73 {
  74         iface->ifindex = if_nametoindex(interface_name(iface));
  75         uloop_timeout_set(&reload_timer, 1);
  76 }
  77
  78 static void
  79 interface_init(struct interface *iface)
  80 {
  81         interface_check(iface);
  82 }
  83
  84 static void
  85 interface_free(struct interface *iface)
  86 {
  87         avl_delete(&interfaces.avl, &iface->node.avl);
  88         free(iface);
  89 }
  90
  91 static void
  92 interfaces_update_cb(struct vlist_tree *tree,
  93                      struct vlist_node *node_new,
  94                      struct vlist_node *node_old)
  95 {
  96         struct interface *iface;
  97
  98         if (node_new && node_old) {
  99                 iface = container_of(node_new, struct interface, node);
 100                 free(iface);
 101                 iface = container_of(node_old, struct interface, node);
 102                 interface_check(iface);
 103         } else if (node_old) {
 104                 iface = container_of(node_old, struct interface, node);
 105                 interface_free(iface);
 106         } else {
 107                 iface = container_of(node_new, struct interface, node);
 108                 interface_init(iface);
 109         }
 110 }
 111
 112 void usteer_interface_add(const char *name)
 113 {
 114         struct interface *iface;
 115         char *name_buf;
 116
 117         iface = calloc_a(sizeof(*iface), &name_buf, strlen(name) + 1);
 118         strcpy(name_buf, name);
 119         vlist_add(&interfaces, &iface->node, name_buf);
 120 }
 121
 122 void config_set_interfaces(struct blob_attr *data)
 123 {
 124         struct blob_attr *cur;
 125         int rem;
 126
 127         if (!data)
 128                 return;
 129
 130         if (!blobmsg_check_attr_list(data, BLOBMSG_TYPE_STRING))
 131                 return;
 132
 133         vlist_update(&interfaces);
 134         blobmsg_for_each_attr(cur, data, rem) {
 135                 usteer_interface_add(blobmsg_data(cur));
 136         }
 137         vlist_flush(&interfaces);
 138 }
 139
 140 void config_get_interfaces(struct blob_buf *buf)
 141 {
 142         struct interface *iface;
 143         void *c;
 144
 145         c = blobmsg_open_array(buf, "interfaces");
 146         vlist_for_each_element(&interfaces, iface, node) {
 147                 blobmsg_add_string(buf, NULL, interface_name(iface));
 148         }
 149         blobmsg_close_array(buf, c);
 150 }
 151
 152 static void
 153 interface_add_station(struct usteer_remote_node *node, struct blob_attr *data)
 154 {
 155         struct sta *sta;
 156         struct sta_info *si;
 157         struct apmsg_sta msg;
 158         bool create;
 159
 160         if (!parse_apmsg_sta(&msg, data)) {
 161                 MSG(DEBUG, "Cannot parse station in message\n");
 162                 return;
 163         }
 164
 165         if (msg.timeout <= 0) {
 166                 MSG(DEBUG, "Refuse to add an already expired station entry\n");
 167                 return;
 168         }
 169
 170         sta = usteer_sta_get(msg.addr, true);
 171         if (!sta)
 172                 return;
 173
 174         si = usteer_sta_info_get(sta, &node->node, &create);
 175         if (!si)
 176                 return;
 177
 178         si->connected = msg.connected;
 179         si->signal = msg.signal;
 180         si->seen = current_time - msg.seen;
 181         usteer_sta_info_update_timeout(si, msg.timeout);
 182 }
 183
 184 static void
 185 remote_node_free(struct usteer_remote_node *node)
 186 {
 187         struct usteer_remote_host *host = node->host;
 188
 189         list_del(&node->list);
 190         list_del(&node->host_list);
 191         usteer_sta_node_cleanup(&node->node);
 192         free(node);
 193
 194         if (!list_empty(&host->nodes))
 195                 return;
 196
 197         avl_delete(&remote_hosts, &host->avl);
 198         free(host);
 199 }
 200
 201 static struct usteer_remote_host *
 202 interface_get_host(const char *addr, unsigned long id)
 203 {
 204         struct usteer_remote_host *host;
 205
 206         host = avl_find_element(&remote_hosts, (void *)id, host, avl);
 207         if (host)
 208                 goto out;
 209
 210         host = calloc(1, sizeof(*host));
 211         host->avl.key = (void *)id;
 212         INIT_LIST_HEAD(&host->nodes);
 213         avl_insert(&remote_hosts, &host->avl);
 214
 215 out:
 216         if (host->addr && strcmp(host->addr, addr) != 0)
 217                 return host;
 218
 219         free(host->addr);
 220         host->addr = strdup(addr);
 221
 222         return host;
 223 }
 224
 225 static struct usteer_remote_node *
 226 interface_get_node(struct usteer_remote_host *host, const char *name)
 227 {
 228         struct usteer_remote_node *node;
 229         int addr_len = strlen(host->addr);
 230         char *buf;
 231
 232         list_for_each_entry(node, &host->nodes, host_list)
 233                 if (!strcmp(node->name, name))
 234                         return node;
 235
 236         node = calloc_a(sizeof(*node), &buf, addr_len + 1 + strlen(name) + 1);
 237         node->node.type = NODE_TYPE_REMOTE;
 238
 239         sprintf(buf, "%s#%s", host->addr, name);
 240         node->node.avl.key = buf;
 241         node->name = buf + addr_len + 1;
 242         node->host = host;
 243         INIT_LIST_HEAD(&node->node.sta_info);
 244
 245         list_add_tail(&node->list, &remote_nodes);
 246         list_add_tail(&node->host_list, &host->nodes);
 247
 248         return node;
 249 }
 250
 251 static void
 252 interface_add_node(struct usteer_remote_host *host, struct blob_attr *data)
 253 {
 254         struct usteer_remote_node *node;
 255         struct apmsg_node msg;
 256         struct blob_attr *cur;
 257         int rem;
 258
 259         if (!parse_apmsg_node(&msg, data)) {
 260                 MSG(DEBUG, "Cannot parse node in message\n");
 261                 return;
 262         }
 263
 264         node = interface_get_node(host, msg.name);
 265         node->check = 0;
 266         node->node.freq = msg.freq;
 267         node->node.n_assoc = msg.n_assoc;
 268         node->node.max_assoc = msg.max_assoc;
 269         node->node.noise = msg.noise;
 270         node->node.load = msg.load;
 271         snprintf(node->node.ssid, sizeof(node->node.ssid), "%s", msg.ssid);
 272         usteer_node_set_blob(&node->node.rrm_nr, msg.rrm_nr);
 273         usteer_node_set_blob(&node->node.node_info, msg.node_info);
 274
 275         blob_for_each_attr(cur, msg.stations, rem)
 276                 interface_add_station(node, cur);
 277 }
 278
 279 static void
 280 interface_recv_msg(struct interface *iface, struct in_addr *addr, void *buf, int len)
 281 {
 282         struct usteer_remote_host *host;
 283         char addr_str[INET_ADDRSTRLEN];
 284         struct blob_attr *data = buf;
 285         struct apmsg msg;
 286         struct blob_attr *cur;
 287         int rem;
 288
 289         if (blob_pad_len(data) != len) {
 290                 MSG(DEBUG, "Invalid message length (header: %d, real: %d)\n", blob_pad_len(data), len);
 291                 return;
 292         }
 293
 294         if (!parse_apmsg(&msg, data)) {
 295                 MSG(DEBUG, "Missing fields in message\n");
 296                 return;
 297         }
 298
 299         if (msg.id == local_id)
 300                 return;
 301
 302         MSG(NETWORK, "Received message on %s (id=%08x->%08x seq=%d len=%d)\n",
 303                 interface_name(iface), msg.id, local_id, msg.seq, len);
 304
 305         inet_ntop(AF_INET, addr, addr_str, sizeof(addr_str));
 306
 307         host = interface_get_host(addr_str, msg.id);
 308
 309         blob_for_each_attr(cur, msg.nodes, rem)
 310                 interface_add_node(host, cur);
 311 }
 312
 313 static struct interface *
 314 interface_find_by_ifindex(int index)
 315 {
 316         struct interface *iface;
 317
 318         vlist_for_each_element(&interfaces, iface, node) {
 319                 if (iface->ifindex == index)
 320                         return iface;
 321         }
 322
 323         return NULL;
 324 }
 325
 326 static void
 327 interface_recv(struct uloop_fd *u, unsigned int events)
 328 {
 329         static char buf[APMGR_BUFLEN];
 330         static char cmsg_buf[( CMSG_SPACE(sizeof(struct in_pktinfo)) + sizeof(int)) + 1];
 331         static struct sockaddr_in sin;
 332         static struct iovec iov = {
 333                 .iov_base = buf,
 334                 .iov_len = sizeof(buf)
 335         };
 336         static struct msghdr msg = {
 337                 .msg_name = &sin,
 338                 .msg_namelen = sizeof(sin),
 339                 .msg_iov = &iov,
 340                 .msg_iovlen = 1,
 341                 .msg_control = cmsg_buf,
 342                 .msg_controllen = sizeof(cmsg_buf),
 343         };
 344         struct cmsghdr *cmsg;
 345         int len;
 346
 347         do {
 348                 struct in_pktinfo *pkti = NULL;
 349                 struct interface *iface;
 350
 351                 len = recvmsg(u->fd, &msg, 0);
 352                 if (len < 0) {
 353                         switch (errno) {
 354                         case EAGAIN:
 355                                 return;
 356                         case EINTR:
 357                                 continue;
 358                         default:
 359                                 perror("recvmsg");
 360                                 uloop_fd_delete(u);
 361                                 return;
 362                         }
 363                 }
 364
 365                 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
 366                         if (cmsg->cmsg_type != IP_PKTINFO)
 367                                 continue;
 368
 369                         pkti = (struct in_pktinfo *) CMSG_DATA(cmsg);
 370                 }
 371
 372                 if (!pkti) {
 373                         MSG(DEBUG, "Received packet without ifindex\n");
 374                         continue;
 375                 }
 376
 377                 iface = interface_find_by_ifindex(pkti->ipi_ifindex);
 378                 if (!iface) {
 379                         MSG(DEBUG, "Received packet from unconfigured interface %d\n", pkti->ipi_ifindex);
 380                         continue;
 381                 }
 382
 383                 interface_recv_msg(iface, &sin.sin_addr, buf, len);
 384         } while (1);
 385 }
 386
 387 static void interface_send_msg(struct interface *iface, struct blob_attr *data)
 388 {
 389         static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1];
 390         static struct sockaddr_in a;
 391         static struct iovec iov;
 392         static struct msghdr m = {
 393                 .msg_name = (struct sockaddr *) &a,
 394                 .msg_namelen = sizeof(a),
 395                 .msg_iov = &iov,
 396                 .msg_iovlen = 1,
 397                 .msg_control = cmsg_data,
 398                 .msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)),
 399         };
 400         struct in_pktinfo *pkti;
 401         struct cmsghdr *cmsg;
 402
 403         a.sin_family = AF_INET;
 404         a.sin_port = htons(16720);
 405         a.sin_addr.s_addr = ~0;
 406
 407         memset(cmsg_data, 0, sizeof(cmsg_data));
 408         cmsg = CMSG_FIRSTHDR(&m);
 409         cmsg->cmsg_len = m.msg_controllen;
 410         cmsg->cmsg_level = IPPROTO_IP;
 411         cmsg->cmsg_type = IP_PKTINFO;
 412
 413         pkti = (struct in_pktinfo *) CMSG_DATA(cmsg);
 414         pkti->ipi_ifindex = iface->ifindex;
 415
 416         iov.iov_base = data;
 417         iov.iov_len = blob_pad_len(data);
 418
 419         if (sendmsg(remote_fd.fd, &m, 0) < 0)
 420                 perror("sendmsg");
 421 }
 422
 423 static void usteer_send_sta_info(struct sta_info *sta)
 424 {
 425         int seen = current_time - sta->seen;
 426         void *c;
 427
 428         c = blob_nest_start(&buf, 0);
 429         blob_put(&buf, APMSG_STA_ADDR, sta->sta->addr, 6);
 430         blob_put_int8(&buf, APMSG_STA_CONNECTED, !!sta->connected);
 431         blob_put_int32(&buf, APMSG_STA_SIGNAL, sta->signal);
 432         blob_put_int32(&buf, APMSG_STA_SEEN, seen);
 433         blob_put_int32(&buf, APMSG_STA_TIMEOUT, config.local_sta_timeout - seen);
 434         blob_nest_end(&buf, c);
 435 }
 436
 437 static void usteer_send_node(struct usteer_node *node, struct sta_info *sta)
 438 {
 439         void *c, *s, *r;
 440
 441         c = blob_nest_start(&buf, 0);
 442
 443         blob_put_string(&buf, APMSG_NODE_NAME, usteer_node_name(node));
 444         blob_put_string(&buf, APMSG_NODE_SSID, node->ssid);
 445         blob_put_int32(&buf, APMSG_NODE_FREQ, node->freq);
 446         blob_put_int32(&buf, APMSG_NODE_NOISE, node->noise);
 447         blob_put_int32(&buf, APMSG_NODE_LOAD, node->load);
 448         blob_put_int32(&buf, APMSG_NODE_N_ASSOC, node->n_assoc);
 449         blob_put_int32(&buf, APMSG_NODE_MAX_ASSOC, node->max_assoc);
 450         if (node->rrm_nr) {
 451                 r = blob_nest_start(&buf, APMSG_NODE_RRM_NR);
 452                 blobmsg_add_field(&buf, BLOBMSG_TYPE_ARRAY, "",
 453                                   blobmsg_data(node->rrm_nr),
 454                                   blobmsg_data_len(node->rrm_nr));
 455                 blob_nest_end(&buf, r);
 456         }
 457
 458         if (node->node_info)
 459                 blob_put(&buf, APMSG_NODE_NODE_INFO,
 460                          blob_data(node->node_info),
 461                          blob_len(node->node_info));
 462
 463         s = blob_nest_start(&buf, APMSG_NODE_STATIONS);
 464
 465         if (sta) {
 466                 usteer_send_sta_info(sta);
 467         } else {
 468                 list_for_each_entry(sta, &node->sta_info, node_list)
 469                         usteer_send_sta_info(sta);
 470         }
 471
 472         blob_nest_end(&buf, s);
 473
 474         blob_nest_end(&buf, c);
 475 }
 476
 477 static void
 478 usteer_check_timeout(void)
 479 {
 480         struct usteer_remote_node *node, *tmp;
 481         int timeout = config.remote_node_timeout / config.remote_update_interval;
 482
 483         list_for_each_entry_safe(node, tmp, &remote_nodes, list) {
 484                 if (node->check++ > timeout)
 485                         remote_node_free(node);
 486         }
 487 }
 488
 489 static void *
 490 usteer_update_init(void)
 491 {
 492         blob_buf_init(&buf, 0);
 493         blob_put_int32(&buf, APMSG_ID, local_id);
 494         blob_put_int32(&buf, APMSG_SEQ, ++msg_seq);
 495
 496         return blob_nest_start(&buf, APMSG_NODES);
 497 }
 498
 499 static void
 500 usteer_update_send(void *c)
 501 {
 502         struct interface *iface;
 503
 504         blob_nest_end(&buf, c);
 505
 506         vlist_for_each_element(&interfaces, iface, node)
 507                 interface_send_msg(iface, buf.head);
 508 }
 509
 510 void
 511 usteer_send_sta_update(struct sta_info *si)
 512 {
 513         void *c = usteer_update_init();
 514         usteer_send_node(si->node, si);
 515         usteer_update_send(c);
 516 }
 517
 518 static void
 519 usteer_send_update_timer(struct uloop_timeout *t)
 520 {
 521         struct usteer_node *node;
 522         void *c;
 523
 524         usteer_update_time();
 525         uloop_timeout_set(t, config.remote_update_interval);
 526
 527         c = usteer_update_init();
 528         for_each_local_node(node)
 529                 usteer_send_node(node, NULL);
 530
 531         usteer_update_send(c);
 532         usteer_check_timeout();
 533 }
 534
 535 static int
 536 usteer_init_local_id(void)
 537 {
 538         FILE *f;
 539
 540         f = fopen("/dev/urandom", "r");
 541         if (!f) {
 542                 perror("fopen(/dev/urandom)");
 543                 return -1;
 544         }
 545
 546         if (fread(&local_id, sizeof(local_id), 1, f) < 1)
 547                 return -1;
 548
 549         fclose(f);
 550         return 0;
 551 }
 552
 553 static void
 554 usteer_reload_timer(struct uloop_timeout *t)
 555 {
 556         int yes = 1;
 557         int fd;
 558
 559         if (remote_fd.registered) {
 560                 uloop_fd_delete(&remote_fd);
 561                 close(remote_fd.fd);
 562         }
 563
 564         fd = usock(USOCK_UDP | USOCK_SERVER | USOCK_NONBLOCK |
 565                    USOCK_NUMERIC | USOCK_IPV4ONLY,
 566                    "0.0.0.0", APMGR_PORT_STR);
 567         if (fd < 0) {
 568                 perror("usock");
 569                 return;
 570         }
 571
 572         if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0)
 573                 perror("setsockopt(IP_PKTINFO)");
 574
 575         if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &yes, sizeof(yes)) < 0)
 576                 perror("setsockopt(SO_BROADCAST)");
 577
 578         remote_fd.fd = fd;
 579         remote_fd.cb = interface_recv;
 580         uloop_fd_add(&remote_fd, ULOOP_READ);
 581 }
 582
 583 int usteer_interface_init(void)
 584 {
 585         if (usteer_init_local_id())
 586                 return -1;
 587
 588         remote_timer.cb = usteer_send_update_timer;
 589         remote_timer.cb(&remote_timer);
 590
 591         reload_timer.cb = usteer_reload_timer;
 592         reload_timer.cb(&reload_timer);
 593
 594         return 0;
 595 }