git.meshlink.io Git - meshlink/blob - src/discovery.c

   1 #include "system.h"
   2
   3 #include <catta/core.h>
   4 #include <catta/lookup.h>
   5 #include <catta/publish.h>
   6 #include <catta/log.h>
   7 #include <catta/simple-watch.h>
   8 #include <catta/malloc.h>
   9 #include <catta/alternative.h>
  10 #include <catta/error.h>
  11
  12 #include "meshlink_internal.h"
  13 #include "discovery.h"
  14 #include "sockaddr.h"
  15 #include "logger.h"
  16 #include "node.h"
  17 #include "connection.h"
  18
  19 #define MESHLINK_MDNS_SERVICE_TYPE "_%s._tcp"
  20 #define MESHLINK_MDNS_NAME_KEY "name"
  21 #define MESHLINK_MDNS_FINGERPRINT_KEY "fingerprint"
  22
  23 static void generate_rand_string(char *buffer, size_t size) {
  24         for(size_t i = 0; i < (size - 1); ++i) {
  25                 buffer[i] = 'a' + (rand() % ('z' - 'a' + 1));
  26         }
  27
  28         buffer[size - 1] = '\0';
  29 }
  30
  31 static void discovery_entry_group_callback(CattaServer *server, CattaSEntryGroup *group, CattaEntryGroupState state, void *userdata) {
  32         (void)server;
  33         (void)group;
  34         meshlink_handle_t *mesh = userdata;
  35
  36         // asserts
  37         assert(mesh != NULL);
  38         assert(mesh->catta_server != NULL);
  39         assert(mesh->catta_poll != NULL);
  40
  41         pthread_mutex_lock(&(mesh->mesh_mutex));
  42
  43         /* Called whenever the entry group state changes */
  44         switch(state) {
  45         case CATTA_ENTRY_GROUP_ESTABLISHED:
  46                 /* The entry group has been established successfully */
  47                 logger(mesh, MESHLINK_DEBUG, "Catta Service successfully established.\n");
  48                 break;
  49
  50         case CATTA_ENTRY_GROUP_COLLISION:
  51                 logger(mesh, MESHLINK_WARNING, "Catta Service collision.\n");
  52                 // @TODO can we just set a new name and retry?
  53                 break;
  54
  55         case CATTA_ENTRY_GROUP_FAILURE :
  56                 /* Some kind of failure happened while we were registering our services */
  57                 logger(mesh, MESHLINK_ERROR, "Catta Entry group failure: %s\n", catta_strerror(catta_server_errno(mesh->catta_server)));
  58                 catta_simple_poll_quit(mesh->catta_poll);
  59                 break;
  60
  61         case CATTA_ENTRY_GROUP_UNCOMMITED:
  62         case CATTA_ENTRY_GROUP_REGISTERING:
  63                 ;
  64         }
  65
  66         pthread_mutex_unlock(&(mesh->mesh_mutex));
  67 }
  68
  69
  70 static void discovery_create_services(meshlink_handle_t *mesh) {
  71         char *fingerprint = NULL;
  72         char *txt_name = NULL;
  73         char *txt_fingerprint = NULL;
  74
  75         // asserts
  76         assert(mesh != NULL);
  77         assert(mesh->name != NULL);
  78         assert(mesh->myport != NULL);
  79         assert(mesh->catta_server != NULL);
  80         assert(mesh->catta_poll != NULL);
  81         assert(mesh->catta_servicetype != NULL);
  82         assert(mesh->self != NULL);
  83
  84         pthread_mutex_lock(&(mesh->mesh_mutex));
  85
  86         logger(mesh, MESHLINK_DEBUG, "Adding service\n");
  87
  88         /* Ifthis is the first time we're called, let's create a new entry group */
  89         if(!mesh->catta_group) {
  90                 if(!(mesh->catta_group = catta_s_entry_group_new(mesh->catta_server, discovery_entry_group_callback, mesh))) {
  91                         logger(mesh, MESHLINK_ERROR, "catta_entry_group_new() failed: %s\n", catta_strerror(catta_server_errno(mesh->catta_server)));
  92                         goto fail;
  93                 }
  94         }
  95
  96         /* Create txt records */
  97         fingerprint = meshlink_get_fingerprint(mesh, (meshlink_node_t *)mesh->self);
  98         xasprintf(&txt_name, "%s=%s", MESHLINK_MDNS_NAME_KEY, mesh->name);
  99         xasprintf(&txt_fingerprint, "%s=%s", MESHLINK_MDNS_FINGERPRINT_KEY, fingerprint);
 100
 101         /* Add the service */
 102         int ret = 0;
 103
 104         if((ret = catta_server_add_service(mesh->catta_server, mesh->catta_group, CATTA_IF_UNSPEC, CATTA_PROTO_UNSPEC, 0, fingerprint, mesh->catta_servicetype, NULL, NULL, atoi(mesh->myport), txt_name, txt_fingerprint, NULL)) < 0) {
 105                 logger(mesh, MESHLINK_ERROR, "Failed to add service: %s\n", catta_strerror(ret));
 106                 goto fail;
 107         }
 108
 109         /* Tell the server to register the service */
 110         if((ret = catta_s_entry_group_commit(mesh->catta_group)) < 0) {
 111                 logger(mesh, MESHLINK_ERROR, "Failed to commit entry_group: %s\n", catta_strerror(ret));
 112                 goto fail;
 113         }
 114
 115         goto done;
 116
 117 fail:
 118         catta_simple_poll_quit(mesh->catta_poll);
 119
 120 done:
 121         free(fingerprint);
 122         free(txt_name);
 123         free(txt_fingerprint);
 124
 125         pthread_mutex_unlock(&(mesh->mesh_mutex));
 126 }
 127
 128 static void discovery_server_callback(CattaServer *server, CattaServerState state, void *userdata) {
 129         (void)server;
 130         meshlink_handle_t *mesh = userdata;
 131
 132         // asserts
 133         assert(mesh != NULL);
 134
 135         switch(state) {
 136         case CATTA_SERVER_RUNNING:
 137
 138                 /* The serve has startup successfully and registered its host
 139                  * name on the network, so it's time to create our services */
 140                 if(!mesh->catta_group) {
 141                         discovery_create_services(mesh);
 142                 }
 143
 144                 break;
 145
 146         case CATTA_SERVER_COLLISION: {
 147                 // asserts
 148                 assert(mesh->catta_server != NULL);
 149                 assert(mesh->catta_poll != NULL);
 150
 151                 /* A host name collision happened. Let's pick a new name for the server */
 152                 char hostname[17];
 153                 generate_rand_string(hostname, sizeof(hostname));
 154                 int result = catta_server_set_host_name(mesh->catta_server, hostname);
 155
 156                 if(result < 0) {
 157                         catta_simple_poll_quit(mesh->catta_poll);
 158                 }
 159         }
 160         break;
 161
 162         case CATTA_SERVER_REGISTERING:
 163
 164                 /* Let's drop our registered services. When the server is back
 165                  * in CATTA_SERVER_RUNNING state we will register them
 166                  * again with the new host name. */
 167                 if(mesh->catta_group) {
 168                         catta_s_entry_group_reset(mesh->catta_group);
 169                         mesh->catta_group = NULL;
 170                 }
 171
 172                 break;
 173
 174         case CATTA_SERVER_FAILURE:
 175                 // asserts
 176                 assert(mesh->catta_server != NULL);
 177                 assert(mesh->catta_poll != NULL);
 178
 179                 /* Terminate on failure */
 180                 catta_simple_poll_quit(mesh->catta_poll);
 181                 break;
 182
 183         case CATTA_SERVER_INVALID:
 184                 break;
 185         }
 186 }
 187
 188 static void discovery_resolve_callback(CattaSServiceResolver *resolver, CattaIfIndex interface_, CattaProtocol protocol, CattaResolverEvent event, const char *name, const char *type, const char *domain, const char *host_name, const CattaAddress *address, uint16_t port, CattaStringList *txt, CattaLookupResultFlags flags, void *userdata) {
 189         (void)interface_;
 190         (void)protocol;
 191         (void)flags;
 192         meshlink_handle_t *mesh = userdata;
 193
 194         // asserts
 195         assert(resolver != NULL);
 196         assert(mesh != NULL);
 197         assert(mesh->catta_server != NULL);
 198
 199         /* Called whenever a service has been resolved successfully or timed out */
 200         switch(event) {
 201         case CATTA_RESOLVER_FAILURE:
 202                 // asserts
 203                 assert(name != NULL);
 204                 assert(type != NULL);
 205                 assert(domain != NULL);
 206                 break;
 207
 208         case CATTA_RESOLVER_FOUND: {
 209                 // asserts
 210                 assert(name != NULL);
 211                 assert(type != NULL);
 212                 assert(domain != NULL);
 213                 assert(host_name != NULL);
 214                 assert(address != NULL);
 215                 assert(txt != NULL);
 216
 217                 // retrieve fingerprint
 218                 CattaStringList *node_name_li = catta_string_list_find(txt, MESHLINK_MDNS_NAME_KEY);
 219                 CattaStringList *node_fp_li = catta_string_list_find(txt, MESHLINK_MDNS_FINGERPRINT_KEY);
 220
 221                 if(node_name_li != NULL && node_fp_li != NULL) {
 222                         char *node_name = (char *)catta_string_list_get_text(node_name_li) + strlen(MESHLINK_MDNS_NAME_KEY);
 223                         char *node_fp = (char *)catta_string_list_get_text(node_fp_li) + strlen(MESHLINK_MDNS_FINGERPRINT_KEY);
 224
 225                         if(node_name[0] == '=' && node_fp[0] == '=') {
 226                                 pthread_mutex_lock(&(mesh->mesh_mutex));
 227
 228                                 node_name += 1;
 229                                 node_fp += 1;
 230
 231                                 meshlink_node_t *node = meshlink_get_node(mesh, node_name);
 232
 233                                 if(node != NULL) {
 234                                         logger(mesh, MESHLINK_INFO, "Node %s is part of the mesh network.\n", node->name);
 235
 236                                         sockaddr_t naddress;
 237                                         memset(&naddress, 0, sizeof(naddress));
 238
 239                                         switch(address->proto) {
 240                                         case CATTA_PROTO_INET: {
 241                                                 naddress.in.sin_family = AF_INET;
 242                                                 naddress.in.sin_port = htons(port);
 243                                                 naddress.in.sin_addr.s_addr = address->data.ipv4.address;
 244                                         }
 245                                         break;
 246
 247                                         case CATTA_PROTO_INET6: {
 248                                                 naddress.in6.sin6_family = AF_INET6;
 249                                                 naddress.in6.sin6_port = htons(port);
 250                                                 memcpy(naddress.in6.sin6_addr.s6_addr, address->data.ipv6.address, sizeof(naddress.in6.sin6_addr.s6_addr));
 251                                         }
 252                                         break;
 253
 254                                         default:
 255                                                 naddress.unknown.family = AF_UNKNOWN;
 256                                                 break;
 257                                         }
 258
 259                                         if(naddress.unknown.family != AF_UNKNOWN) {
 260                                                 meshlink_hint_address(mesh, (meshlink_node_t *)node, (struct sockaddr *)&naddress);
 261                                                 pthread_mutex_lock(&(mesh->mesh_mutex));
 262
 263                                                 node_t *n = (node_t *)node;
 264
 265                                                 if(n->connection && n->connection->outgoing) {
 266                                                         n->connection->outgoing->timeout = 0;
 267
 268                                                         if(n->connection->outgoing->ev.cb) {
 269                                                                 timeout_set(&mesh->loop, &n->connection->outgoing->ev, &(struct timeval) {
 270                                                                         0, 0
 271                                                                 });
 272                                                         }
 273
 274                                                         n->connection->last_ping_time = 0;
 275                                                 }
 276
 277                                                 pthread_mutex_unlock(&(mesh->mesh_mutex));
 278                                         } else {
 279                                                 logger(mesh, MESHLINK_WARNING, "Could not resolve node %s to a known address family type.\n", node->name);
 280                                         }
 281                                 } else {
 282                                         logger(mesh, MESHLINK_WARNING, "Node %s is not part of the mesh network.\n", node_name);
 283                                 }
 284
 285                                 pthread_mutex_unlock(&(mesh->mesh_mutex));
 286                         }
 287                 }
 288         }
 289         break;
 290         }
 291
 292         catta_s_service_resolver_free(resolver);
 293 }
 294
 295 static void discovery_browse_callback(CattaSServiceBrowser *browser, CattaIfIndex interface_, CattaProtocol protocol, CattaBrowserEvent event, const char *name, const char *type, const char *domain, CattaLookupResultFlags flags, void *userdata) {
 296         (void)browser;
 297         (void)flags;
 298         meshlink_handle_t *mesh = userdata;
 299
 300         // asserts
 301         assert(mesh != NULL);
 302         assert(mesh->catta_server != NULL);
 303         assert(mesh->catta_poll != NULL);
 304
 305         /* Called whenever a new services becomes available on the LAN or is removed from the LAN */
 306         switch(event) {
 307         case CATTA_BROWSER_FAILURE:
 308                 catta_simple_poll_quit(mesh->catta_poll);
 309                 break;
 310
 311         case CATTA_BROWSER_NEW:
 312                 catta_s_service_resolver_new(mesh->catta_server, interface_, protocol, name, type, domain, CATTA_PROTO_UNSPEC, 0, discovery_resolve_callback, mesh);
 313                 break;
 314
 315         case CATTA_BROWSER_REMOVE:
 316         case CATTA_BROWSER_ALL_FOR_NOW:
 317         case CATTA_BROWSER_CACHE_EXHAUSTED:
 318                 break;
 319         }
 320 }
 321
 322 static void *discovery_loop(void *userdata) {
 323         meshlink_handle_t *mesh = userdata;
 324
 325         // asserts
 326         assert(mesh != NULL);
 327         assert(mesh->catta_poll != NULL);
 328
 329         catta_simple_poll_loop(mesh->catta_poll);
 330
 331         return NULL;
 332 }
 333
 334 static void discovery_log_cb(CattaLogLevel level, const char *txt) {
 335         meshlink_log_level_t mlevel = MESHLINK_CRITICAL;
 336
 337         switch(level) {
 338         case CATTA_LOG_ERROR:
 339                 mlevel = MESHLINK_ERROR;
 340                 break;
 341
 342         case CATTA_LOG_WARN:
 343                 mlevel = MESHLINK_WARNING;
 344                 break;
 345
 346         case CATTA_LOG_NOTICE:
 347         case CATTA_LOG_INFO:
 348                 mlevel = MESHLINK_INFO;
 349                 break;
 350
 351         case CATTA_LOG_DEBUG:
 352         default:
 353                 mlevel = MESHLINK_DEBUG;
 354                 break;
 355         }
 356
 357         logger(NULL, mlevel, "%s\n", txt);
 358 }
 359
 360 bool discovery_start(meshlink_handle_t *mesh) {
 361         logger(mesh, MESHLINK_DEBUG, "discovery_start called\n");
 362
 363         // asserts
 364         assert(mesh != NULL);
 365         assert(mesh->catta_poll == NULL);
 366         assert(mesh->catta_server == NULL);
 367         assert(mesh->catta_browser == NULL);
 368         assert(mesh->discovery_threadstarted == false);
 369         assert(mesh->catta_servicetype == NULL);
 370
 371         // handle catta logs
 372         catta_set_log_function(discovery_log_cb);
 373
 374         // create service type string
 375         size_t servicetype_strlen = sizeof(MESHLINK_MDNS_SERVICE_TYPE) + strlen(mesh->appname) + 1;
 376         mesh->catta_servicetype = malloc(servicetype_strlen);
 377
 378         if(mesh->catta_servicetype == NULL) {
 379                 logger(mesh, MESHLINK_ERROR, "Failed to allocate memory for service type string.\n");
 380                 goto fail;
 381         }
 382
 383         snprintf(mesh->catta_servicetype, servicetype_strlen, MESHLINK_MDNS_SERVICE_TYPE, mesh->appname);
 384
 385         // Allocate discovery loop object
 386         if(!(mesh->catta_poll = catta_simple_poll_new())) {
 387                 logger(mesh, MESHLINK_ERROR, "Failed to create discovery poll object.\n");
 388                 goto fail;
 389         }
 390
 391         // generate some unique host name (we actually do not care about it)
 392         char hostname[17];
 393         generate_rand_string(hostname, sizeof(hostname));
 394
 395         // Let's set the host name for this server.
 396         CattaServerConfig config;
 397         catta_server_config_init(&config);
 398         config.host_name = catta_strdup(hostname);
 399         config.publish_workstation = 0;
 400         config.disallow_other_stacks = 0;
 401         config.publish_hinfo = 0;
 402         config.publish_addresses = 1;
 403         config.publish_no_reverse = 1;
 404
 405         /* Allocate a new server */
 406         int error;
 407         mesh->catta_server = catta_server_new(catta_simple_poll_get(mesh->catta_poll), &config, discovery_server_callback, mesh, &error);
 408
 409         /* Free the configuration data */
 410         catta_server_config_free(&config);
 411
 412         /* Check wether creating the server object succeeded */
 413         if(!mesh->catta_server) {
 414                 logger(mesh, MESHLINK_ERROR, "Failed to create discovery server: %s\n", catta_strerror(error));
 415                 goto fail;
 416         }
 417
 418         // Create the service browser
 419         if(!(mesh->catta_browser = catta_s_service_browser_new(mesh->catta_server, CATTA_IF_UNSPEC, CATTA_PROTO_UNSPEC, mesh->catta_servicetype, NULL, 0, discovery_browse_callback, mesh))) {
 420                 logger(mesh, MESHLINK_ERROR, "Failed to create discovery service browser: %s\n", catta_strerror(catta_server_errno(mesh->catta_server)));
 421                 goto fail;
 422         }
 423
 424         // Start the discovery thread
 425         if(pthread_create(&mesh->discovery_thread, NULL, discovery_loop, mesh) != 0) {
 426                 logger(mesh, MESHLINK_ERROR, "Could not start discovery thread: %s\n", strerror(errno));
 427                 memset(&mesh->discovery_thread, 0, sizeof(mesh)->discovery_thread);
 428                 goto fail;
 429         }
 430
 431         mesh->discovery_threadstarted = true;
 432
 433         return true;
 434
 435 fail:
 436
 437         if(mesh->catta_browser != NULL) {
 438                 catta_s_service_browser_free(mesh->catta_browser);
 439                 mesh->catta_browser = NULL;
 440         }
 441
 442         if(mesh->catta_server != NULL) {
 443                 catta_server_free(mesh->catta_server);
 444                 mesh->catta_server = NULL;
 445         }
 446
 447         if(mesh->catta_poll != NULL) {
 448                 catta_simple_poll_free(mesh->catta_poll);
 449                 mesh->catta_poll = NULL;
 450         }
 451
 452         if(mesh->catta_servicetype != NULL) {
 453                 free(mesh->catta_servicetype);
 454                 mesh->catta_servicetype = NULL;
 455         }
 456
 457         return false;
 458 }
 459
 460 void discovery_stop(meshlink_handle_t *mesh) {
 461         logger(mesh, MESHLINK_DEBUG, "discovery_stop called\n");
 462
 463         // asserts
 464         assert(mesh != NULL);
 465
 466         // Shut down
 467         if(mesh->catta_poll) {
 468                 catta_simple_poll_quit(mesh->catta_poll);
 469         }
 470
 471         // Wait for the discovery thread to finish
 472         if(mesh->discovery_threadstarted == true) {
 473                 pthread_join(mesh->discovery_thread, NULL);
 474                 mesh->discovery_threadstarted = false;
 475         }
 476
 477         // Clean up resources
 478         if(mesh->catta_browser != NULL) {
 479                 catta_s_service_browser_free(mesh->catta_browser);
 480                 mesh->catta_browser = NULL;
 481         }
 482
 483         if(mesh->catta_group) {
 484                 catta_s_entry_group_reset(mesh->catta_group);
 485                 catta_s_entry_group_free(mesh->catta_group);
 486                 mesh->catta_group = NULL;
 487         }
 488
 489         if(mesh->catta_server != NULL) {
 490                 catta_server_free(mesh->catta_server);
 491                 mesh->catta_server = NULL;
 492         }
 493
 494         if(mesh->catta_poll != NULL) {
 495                 catta_simple_poll_free(mesh->catta_poll);
 496                 mesh->catta_poll = NULL;
 497         }
 498
 499         if(mesh->catta_servicetype != NULL) {
 500                 free(mesh->catta_servicetype);
 501                 mesh->catta_servicetype = NULL;
 502         }
 503 }