static void reg_context_events( struct mosquitto_db* db, struct epoll_event* events, int* epollfd_index, int efd, time_t now) { int i, s; for(i = 0; i < db->context_count; i++) { if (! db->contexts[i]) continue; db->contexts[i]->pollfd_index = -1; if (db->contexts[i]->sock != INVALID_SOCKET) { #ifdef WITH_BRIDGE if (db->contexts[i]->bridge){ _mosquitto_check_keepalive (db->contexts[i]); } #endif create_context_events(db, events, epollfd_index, efd, now, i); } else { #ifdef WITH_BRIDGE if(db->contexts[i]->bridge){ create_bridge_events(db, events, epollfd_index, efd, i); } else { #endif if(db->contexts[i]->clean_session == true) { mqtt3_context_cleanup(db, db->contexts[i], true); db->contexts[i] = NULL; } else if (db->config->persistent_client_expiration > 0) { /* This is a persistent client, check to see if the * last time it connected was longer than * persistent_client_expiration seconds ago. If so, * expire it and clean up. */ if (time(NULL) > db->contexts[i]->disconnect_t+db->config->persistent_client_expiration){ _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "Expiring persistent client %s due to timeout.", db->contexts[i]->id); g_clients_expired++; db->contexts[i]->clean_session = true; mqtt3_context_cleanup(db, db->contexts[i], true); db->contexts[i] = NULL; } } #ifdef WITH_BRIDGE } #endif } } }
void mosquitto__free_disused_contexts(struct mosquitto_db *db) { struct mosquitto *context, *next; assert(db); context = db->ll_for_free; while(context){ next = context->for_free_next; mqtt3_context_cleanup(db, context, true); context = next; } db->ll_for_free = NULL; }
int mqtt3_handle_connect(struct mosquitto_db *db, struct mosquitto *context) { char *protocol_name = NULL; uint8_t protocol_version; uint8_t connect_flags; char *client_id = NULL; char *will_payload = NULL, *will_topic = NULL; uint16_t will_payloadlen; struct mosquitto_message *will_struct = NULL; uint8_t will, will_retain, will_qos, clean_session; uint8_t username_flag, password_flag; char *username = NULL, *password = NULL; int i; int rc; struct _mosquitto_acl_user *acl_tail; int slen; #ifdef WITH_TLS X509 *client_cert; X509_NAME *name; X509_NAME_ENTRY *name_entry; #endif struct _clientid_index_hash *find_cih; struct _clientid_index_hash *new_cih; #ifdef WITH_SYS_TREE g_connection_count++; #endif /* Don't accept multiple CONNECT commands. */ if(context->state != mosq_cs_new){ mqtt3_context_disconnect(db, context); return MOSQ_ERR_PROTOCOL; } if(_mosquitto_read_string(&context->in_packet, &protocol_name)){ mqtt3_context_disconnect(db, context); return 1; } if(!protocol_name){ mqtt3_context_disconnect(db, context); return 3; } if(strcmp(protocol_name, PROTOCOL_NAME)){ if(db->config->connection_messages == true){ _mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "Invalid protocol \"%s\" in CONNECT from %s.", protocol_name, context->address); } _mosquitto_free(protocol_name); mqtt3_context_disconnect(db, context); return MOSQ_ERR_PROTOCOL; } _mosquitto_free(protocol_name); if(_mosquitto_read_byte(&context->in_packet, &protocol_version)){ mqtt3_context_disconnect(db, context); return 1; } if((protocol_version&0x7F) != PROTOCOL_VERSION){ if(db->config->connection_messages == true){ _mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "Invalid protocol version %d in CONNECT from %s.", protocol_version, context->address); } _mosquitto_send_connack(context, CONNACK_REFUSED_PROTOCOL_VERSION); mqtt3_context_disconnect(db, context); return MOSQ_ERR_PROTOCOL; } if((protocol_version&0x80) == 0x80){ context->is_bridge = true; } if(_mosquitto_read_byte(&context->in_packet, &connect_flags)){ mqtt3_context_disconnect(db, context); return 1; } clean_session = connect_flags & 0x02; will = connect_flags & 0x04; will_qos = (connect_flags & 0x18) >> 3; will_retain = connect_flags & 0x20; password_flag = connect_flags & 0x40; username_flag = connect_flags & 0x80; if(_mosquitto_read_uint16(&context->in_packet, &(context->keepalive))){ mqtt3_context_disconnect(db, context); return 1; } if(_mosquitto_read_string(&context->in_packet, &client_id)){ mqtt3_context_disconnect(db, context); return 1; } slen = strlen(client_id); #ifdef WITH_STRICT_PROTOCOL if(slen > 23 || slen == 0){ #else if(slen == 0){ #endif _mosquitto_free(client_id); _mosquitto_send_connack(context, CONNACK_REFUSED_IDENTIFIER_REJECTED); mqtt3_context_disconnect(db, context); return 1; } /* clientid_prefixes check */ if(db->config->clientid_prefixes){ if(strncmp(db->config->clientid_prefixes, client_id, strlen(db->config->clientid_prefixes))){ _mosquitto_free(client_id); _mosquitto_send_connack(context, CONNACK_REFUSED_NOT_AUTHORIZED); mqtt3_context_disconnect(db, context); return MOSQ_ERR_SUCCESS; } } if(will){ will_struct = _mosquitto_calloc(1, sizeof(struct mosquitto_message)); if(!will_struct){ mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_NOMEM; goto handle_connect_error; } if(_mosquitto_read_string(&context->in_packet, &will_topic)){ mqtt3_context_disconnect(db, context); rc = 1; goto handle_connect_error; } if(strlen(will_topic) == 0){ /* FIXME - CONNACK_REFUSED_IDENTIFIER_REJECTED not really appropriate here. */ _mosquitto_send_connack(context, CONNACK_REFUSED_IDENTIFIER_REJECTED); mqtt3_context_disconnect(db, context); rc = 1; goto handle_connect_error; } if(_mosquitto_read_uint16(&context->in_packet, &will_payloadlen)){ mqtt3_context_disconnect(db, context); rc = 1; goto handle_connect_error; } if(will_payloadlen > 0){ will_payload = _mosquitto_malloc(will_payloadlen); if(!will_payload){ mqtt3_context_disconnect(db, context); rc = 1; goto handle_connect_error; } rc = _mosquitto_read_bytes(&context->in_packet, will_payload, will_payloadlen); if(rc){ mqtt3_context_disconnect(db, context); rc = 1; goto handle_connect_error; } } } if(username_flag){ rc = _mosquitto_read_string(&context->in_packet, &username); if(rc == MOSQ_ERR_SUCCESS){ if(password_flag){ rc = _mosquitto_read_string(&context->in_packet, &password); if(rc == MOSQ_ERR_NOMEM){ rc = MOSQ_ERR_NOMEM; goto handle_connect_error; }else if(rc == MOSQ_ERR_PROTOCOL){ /* Password flag given, but no password. Ignore. */ password_flag = 0; } } }else if(rc == MOSQ_ERR_NOMEM){ rc = MOSQ_ERR_NOMEM; goto handle_connect_error; }else{ /* Username flag given, but no username. Ignore. */ username_flag = 0; } } #ifdef WITH_TLS if(context->listener->use_identity_as_username){ if(!context->ssl){ _mosquitto_send_connack(context, CONNACK_REFUSED_BAD_USERNAME_PASSWORD); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; } #ifdef REAL_WITH_TLS_PSK if(context->listener->psk_hint){ /* Client should have provided an identity to get this far. */ if(!context->username){ _mosquitto_send_connack(context, CONNACK_REFUSED_BAD_USERNAME_PASSWORD); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; } }else{ #endif /* REAL_WITH_TLS_PSK */ client_cert = SSL_get_peer_certificate(context->ssl); if(!client_cert){ _mosquitto_send_connack(context, CONNACK_REFUSED_BAD_USERNAME_PASSWORD); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; } name = X509_get_subject_name(client_cert); if(!name){ _mosquitto_send_connack(context, CONNACK_REFUSED_BAD_USERNAME_PASSWORD); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; } i = X509_NAME_get_index_by_NID(name, NID_commonName, -1); if(i == -1){ _mosquitto_send_connack(context, CONNACK_REFUSED_BAD_USERNAME_PASSWORD); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; } name_entry = X509_NAME_get_entry(name, i); context->username = _mosquitto_strdup((char *)ASN1_STRING_data(name_entry->value)); if(!context->username){ rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; } #ifdef REAL_WITH_TLS_PSK } #endif /* REAL_WITH_TLS_PSK */ }else{ #endif /* WITH_TLS */ if(username_flag){ rc = mosquitto_unpwd_check(db, username, password); if(rc == MOSQ_ERR_AUTH){ _mosquitto_send_connack(context, CONNACK_REFUSED_BAD_USERNAME_PASSWORD); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; }else if(rc == MOSQ_ERR_INVAL){ goto handle_connect_error; } context->username = username; context->password = password; username = NULL; /* Avoid free() in error: below. */ password = NULL; } if(!username_flag && db->config->allow_anonymous == false){ _mosquitto_send_connack(context, CONNACK_REFUSED_NOT_AUTHORIZED); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; } #ifdef WITH_TLS } #endif /* Find if this client already has an entry. This must be done *after* any security checks. */ HASH_FIND_STR(db->clientid_index_hash, client_id, find_cih); if(find_cih){ i = find_cih->db_context_index; /* Found a matching client */ if(db->contexts[i]->sock == -1){ /* Client is reconnecting after a disconnect */ /* FIXME - does anything else need to be done here? */ }else{ /* Client is already connected, disconnect old version */ if(db->config->connection_messages == true){ _mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Client %s already connected, closing old connection.", client_id); } } db->contexts[i]->clean_session = clean_session; mqtt3_context_cleanup(db, db->contexts[i], false); db->contexts[i]->state = mosq_cs_connected; db->contexts[i]->address = _mosquitto_strdup(context->address); db->contexts[i]->sock = context->sock; db->contexts[i]->listener = context->listener; db->contexts[i]->last_msg_in = mosquitto_time(); db->contexts[i]->last_msg_out = mosquitto_time(); db->contexts[i]->keepalive = context->keepalive; db->contexts[i]->pollfd_index = context->pollfd_index; #ifdef WITH_TLS db->contexts[i]->ssl = context->ssl; #endif if(context->username){ db->contexts[i]->username = _mosquitto_strdup(context->username); } context->sock = -1; #ifdef WITH_TLS context->ssl = NULL; #endif context->state = mosq_cs_disconnecting; context = db->contexts[i]; if(context->msgs){ mqtt3_db_message_reconnect_reset(context); } } context->id = client_id; client_id = NULL; context->clean_session = clean_session; context->ping_t = 0; // Add the client ID to the DB hash table here new_cih = _mosquitto_malloc(sizeof(struct _clientid_index_hash)); if(!new_cih){ _mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Error: Out of memory."); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_NOMEM; goto handle_connect_error; } new_cih->id = context->id; new_cih->db_context_index = context->db_index; HASH_ADD_KEYPTR(hh, db->clientid_index_hash, context->id, strlen(context->id), new_cih); #ifdef WITH_PERSISTENCE if(!clean_session){ db->persistence_changes++; } #endif /* Associate user with its ACL, assuming we have ACLs loaded. */ if(db->acl_list){ acl_tail = db->acl_list; while(acl_tail){ if(context->username){ if(acl_tail->username && !strcmp(context->username, acl_tail->username)){ context->acl_list = acl_tail; break; } }else{ if(acl_tail->username == NULL){ context->acl_list = acl_tail; break; } } acl_tail = acl_tail->next; } }else{ context->acl_list = NULL; } if(will_struct){ if(mosquitto_acl_check(db, context, will_topic, MOSQ_ACL_WRITE) != MOSQ_ERR_SUCCESS){ _mosquitto_send_connack(context, CONNACK_REFUSED_NOT_AUTHORIZED); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; } context->will = will_struct; context->will->topic = will_topic; if(will_payload){ context->will->payload = will_payload; context->will->payloadlen = will_payloadlen; }else{ context->will->payload = NULL; context->will->payloadlen = 0; } context->will->qos = will_qos; context->will->retain = will_retain; } if(db->config->connection_messages == true){ _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "New client connected from %s as %s (c%d, k%d).", context->address, context->id, context->clean_session, context->keepalive); } context->state = mosq_cs_connected; return _mosquitto_send_connack(context, CONNACK_ACCEPTED); handle_connect_error: if(client_id) _mosquitto_free(client_id); if(username) _mosquitto_free(username); if(password) _mosquitto_free(password); if(will_payload) _mosquitto_free(will_payload); if(will_topic) _mosquitto_free(will_topic); if(will_struct) _mosquitto_free(will_struct); return rc; } int mqtt3_handle_disconnect(struct mosquitto_db *db, struct mosquitto *context) { if(!context){ return MOSQ_ERR_INVAL; } if(context->in_packet.remaining_length != 0){ return MOSQ_ERR_PROTOCOL; } _mosquitto_log_printf(NULL, MOSQ_LOG_DEBUG, "Received DISCONNECT from %s", context->id); context->state = mosq_cs_disconnecting; mqtt3_context_disconnect(db, context); return MOSQ_ERR_SUCCESS; } int mqtt3_handle_subscribe(struct mosquitto_db *db, struct mosquitto *context) { int rc = 0; int rc2; uint16_t mid; char *sub; uint8_t qos; uint8_t *payload = NULL, *tmp_payload; uint32_t payloadlen = 0; int len; char *sub_mount; if(!context) return MOSQ_ERR_INVAL; _mosquitto_log_printf(NULL, MOSQ_LOG_DEBUG, "Received SUBSCRIBE from %s", context->id); /* FIXME - plenty of potential for memory leaks here */ if(_mosquitto_read_uint16(&context->in_packet, &mid)) return 1; while(context->in_packet.pos < context->in_packet.remaining_length){ sub = NULL; if(_mosquitto_read_string(&context->in_packet, &sub)){ if(payload) _mosquitto_free(payload); return 1; } if(sub){ if(_mosquitto_read_byte(&context->in_packet, &qos)){ _mosquitto_free(sub); if(payload) _mosquitto_free(payload); return 1; } if(qos > 2){ _mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "Invalid QoS in subscription command from %s, disconnecting.", context->address); _mosquitto_free(sub); if(payload) _mosquitto_free(payload); return 1; } if(_mosquitto_fix_sub_topic(&sub)){ _mosquitto_free(sub); if(payload) _mosquitto_free(payload); return 1; } if(!strlen(sub)){ _mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "Empty subscription string from %s, disconnecting.", context->address); _mosquitto_free(sub); if(payload) _mosquitto_free(payload); return 1; } if(context->listener && context->listener->mount_point){ len = strlen(context->listener->mount_point) + strlen(sub) + 1; sub_mount = _mosquitto_calloc(len, sizeof(char)); if(!sub_mount){ _mosquitto_free(sub); if(payload) _mosquitto_free(payload); return MOSQ_ERR_NOMEM; } snprintf(sub_mount, len, "%s%s", context->listener->mount_point, sub); _mosquitto_free(sub); sub = sub_mount; } _mosquitto_log_printf(NULL, MOSQ_LOG_DEBUG, "\t%s (QoS %d)", sub, qos); rc2 = mqtt3_sub_add(db, context, sub, qos, &db->subs); if(rc2 == MOSQ_ERR_SUCCESS){ if(mqtt3_retain_queue(db, context, sub, qos)) rc = 1; }else if(rc2 != -1){ rc = rc2; } _mosquitto_log_printf(NULL, MOSQ_LOG_SUBSCRIBE, "%s %d %s", context->id, qos, sub); _mosquitto_free(sub); tmp_payload = _mosquitto_realloc(payload, payloadlen + 1); if(tmp_payload){ payload = tmp_payload; payload[payloadlen] = qos; payloadlen++; }else{ if(payload) _mosquitto_free(payload); return MOSQ_ERR_NOMEM; } } } if(_mosquitto_send_suback(context, mid, payloadlen, payload)) rc = 1; _mosquitto_free(payload); #ifdef WITH_PERSISTENCE db->persistence_changes++; #endif return rc; }
int mqtt3_socket_accept(struct _mosquitto_db *db, int listensock) { int i; int j; int new_sock = -1; struct mosquitto **tmp_contexts = NULL; struct mosquitto *new_context; int opt = 1; #ifdef WITH_TLS BIO *bio; int rc; #endif #ifdef WITH_WRAP struct request_info wrap_req; #endif new_sock = accept(listensock, NULL, 0); if(new_sock == INVALID_SOCKET) return -1; #ifndef WIN32 /* Set non-blocking */ opt = fcntl(new_sock, F_GETFL, 0); if(opt == -1 || fcntl(new_sock, F_SETFL, opt | O_NONBLOCK) == -1){ /* If either fcntl fails, don't want to allow this client to connect. */ close(new_sock); return -1; } #else if(ioctlsocket(new_sock, FIONBIO, &opt)){ closesocket(new_sock); return INVALID_SOCKET; } #endif #ifdef WITH_WRAP /* Use tcpd / libwrap to determine whether a connection is allowed. */ request_init(&wrap_req, RQ_FILE, new_sock, RQ_DAEMON, "mosquitto", 0); fromhost(&wrap_req); if(!hosts_access(&wrap_req)){ /* Access is denied */ _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "Client connection denied access by tcpd."); COMPAT_CLOSE(new_sock); return -1; }else{ #endif new_context = mqtt3_context_init(new_sock); if(!new_context){ COMPAT_CLOSE(new_sock); return -1; } for(i=0; i<db->config->listener_count; i++){ for(j=0; j<db->config->listeners[i].sock_count; j++){ if(db->config->listeners[i].socks[j] == listensock){ new_context->listener = &db->config->listeners[i]; break; } } } if(!new_context->listener){ COMPAT_CLOSE(new_sock); return -1; } if(new_context->listener->max_connections > 0 && new_context->listener->client_count >= new_context->listener->max_connections){ COMPAT_CLOSE(new_sock); return -1; } _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "New connection from %s.", new_context->address); for(i=0; i<db->context_count; i++){ if(db->contexts[i] == NULL){ db->contexts[i] = new_context; break; } } if(i==db->context_count){ tmp_contexts = _mosquitto_realloc(db->contexts, sizeof(struct mosquitto*)*(db->context_count+1)); if(tmp_contexts){ db->context_count++; db->contexts = tmp_contexts; db->contexts[db->context_count-1] = new_context; }else{ mqtt3_context_cleanup(NULL, new_context, true); } } new_context->listener->client_count++; #ifdef WITH_TLS /* TLS init */ for(i=0; i<db->config->listener_count; i++){ for(j=0; j<db->config->listeners[i].sock_count; j++){ if(db->config->listeners[i].socks[j] == listensock){ if(db->config->listeners[i].ssl_ctx){ new_context->ssl = SSL_new(db->config->listeners[i].ssl_ctx); if(!new_context->ssl){ COMPAT_CLOSE(new_sock); return -1; } SSL_set_ex_data(new_context->ssl, tls_ex_index_context, new_context); SSL_set_ex_data(new_context->ssl, tls_ex_index_listener, &db->config->listeners[i]); new_context->want_read = true; new_context->want_write = true; bio = BIO_new_socket(new_sock, BIO_NOCLOSE); SSL_set_bio(new_context->ssl, bio, bio); rc = SSL_accept(new_context->ssl); if(rc != 1){ rc = SSL_get_error(new_context->ssl, rc); if(rc == SSL_ERROR_WANT_READ){ new_context->want_read = true; }else if(rc == SSL_ERROR_WANT_WRITE){ new_context->want_write = true; } } } } } } #endif #ifdef WITH_WRAP } #endif return new_sock; }
int mosquitto_main_loop(struct mosquitto_db *db, int *listensock, int listensock_count, int listener_max) { time_t start_time = time(NULL); time_t last_backup = time(NULL); time_t last_store_clean = time(NULL); time_t now; int fdcount; #ifndef WIN32 sigset_t sigblock, origsig; #endif int i; struct pollfd *pollfds = NULL; int pollfd_count = 0; int pollfd_index; #ifndef WIN32 sigemptyset(&sigblock); sigaddset(&sigblock, SIGINT); #endif while(run){ mqtt3_db_sys_update(db, db->config->sys_interval, start_time); if(listensock_count + db->context_count > pollfd_count){ pollfd_count = listensock_count + db->context_count; pollfds = _mosquitto_realloc(pollfds, sizeof(struct pollfd)*pollfd_count); if(!pollfds){ _mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Error: Out of memory."); return MOSQ_ERR_NOMEM; } } memset(pollfds, -1, sizeof(struct pollfd)*pollfd_count); pollfd_index = 0; for(i=0; i<listensock_count; i++){ pollfds[pollfd_index].fd = listensock[i]; pollfds[pollfd_index].events = POLLIN; pollfds[pollfd_index].revents = 0; pollfd_index++; } now = time(NULL); for(i=0; i<db->context_count; i++){ if(db->contexts[i]){ db->contexts[i]->pollfd_index = -1; if(db->contexts[i]->sock != INVALID_SOCKET){ #ifdef WITH_BRIDGE if(db->contexts[i]->bridge){ _mosquitto_check_keepalive(db->contexts[i]); } #endif /* Local bridges never time out in this fashion. */ if(!(db->contexts[i]->keepalive) || db->contexts[i]->bridge || now - db->contexts[i]->last_msg_in < (time_t)(db->contexts[i]->keepalive)*3/2){ if(mqtt3_db_message_write(db->contexts[i]) == MOSQ_ERR_SUCCESS){ pollfds[pollfd_index].fd = db->contexts[i]->sock; pollfds[pollfd_index].events = POLLIN | POLLRDHUP; pollfds[pollfd_index].revents = 0; if(db->contexts[i]->out_packet){ pollfds[pollfd_index].events |= POLLOUT; } db->contexts[i]->pollfd_index = pollfd_index; pollfd_index++; }else{ mqtt3_context_disconnect(db, db->contexts[i]); } }else{ if(db->config->connection_messages == true){ _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "Client %s has exceeded timeout, disconnecting.", db->contexts[i]->id); } /* Client has exceeded keepalive*1.5 */ mqtt3_context_disconnect(db, db->contexts[i]); } }else{ #ifdef WITH_BRIDGE if(db->contexts[i]->bridge){ /* Want to try to restart the bridge connection */ if(!db->contexts[i]->bridge->restart_t){ db->contexts[i]->bridge->restart_t = time(NULL)+db->contexts[i]->bridge->restart_timeout; }else{ if(db->contexts[i]->bridge->start_type == bst_automatic && time(NULL) > db->contexts[i]->bridge->restart_t){ db->contexts[i]->bridge->restart_t = 0; if(mqtt3_bridge_connect(db, db->contexts[i]) == MOSQ_ERR_SUCCESS){ pollfds[pollfd_index].fd = db->contexts[i]->sock; pollfds[pollfd_index].events = POLLIN | POLLRDHUP; pollfds[pollfd_index].revents = 0; if(db->contexts[i]->out_packet){ pollfds[pollfd_index].events |= POLLOUT; } db->contexts[i]->pollfd_index = pollfd_index; pollfd_index++; }else{ /* Retry later. */ db->contexts[i]->bridge->restart_t = time(NULL)+db->contexts[i]->bridge->restart_timeout; } } } }else{ #endif if(db->contexts[i]->clean_session == true){ mqtt3_context_cleanup(db, db->contexts[i], true); db->contexts[i] = NULL; }else if(db->config->persistent_client_expiration > 0){ /* This is a persistent client, check to see if the * last time it connected was longer than * persistent_client_expiration seconds ago. If so, * expire it and clean up. */ if(time(NULL) > db->contexts[i]->disconnect_t+db->config->persistent_client_expiration){ _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "Expiring persistent client %s due to timeout.", db->contexts[i]->id); g_clients_expired++; db->contexts[i]->clean_session = true; mqtt3_context_cleanup(db, db->contexts[i], true); db->contexts[i] = NULL; } } #ifdef WITH_BRIDGE } #endif } } } mqtt3_db_message_timeout_check(db, db->config->retry_interval); #ifndef WIN32 sigprocmask(SIG_SETMASK, &sigblock, &origsig); fdcount = poll(pollfds, pollfd_index, 100); sigprocmask(SIG_SETMASK, &origsig, NULL); #else fdcount = WSAPoll(pollfds, pollfd_index, 100); #endif if(fdcount == -1){ loop_handle_errors(db, pollfds); }else{ loop_handle_reads_writes(db, pollfds); for(i=0; i<listensock_count; i++){ if(pollfds[i].revents & (POLLIN | POLLPRI)){ while(mqtt3_socket_accept(db, listensock[i]) != -1){ } } } } #ifdef WITH_PERSISTENCE if(db->config->persistence && db->config->autosave_interval){ if(db->config->autosave_on_changes){ if(db->persistence_changes > db->config->autosave_interval){ mqtt3_db_backup(db, false, false); db->persistence_changes = 0; } }else{ if(last_backup + db->config->autosave_interval < now){ mqtt3_db_backup(db, false, false); last_backup = time(NULL); } } } #endif if(!db->config->store_clean_interval || last_store_clean + db->config->store_clean_interval < now){ mqtt3_db_store_clean(db); last_store_clean = time(NULL); } #ifdef WITH_PERSISTENCE if(flag_db_backup){ mqtt3_db_backup(db, false, false); flag_db_backup = false; } #endif if(flag_reload){ _mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "Reloading config."); mqtt3_config_read(db->config, true); mosquitto_security_cleanup(db, true); mosquitto_security_init(db, true); mosquitto_security_apply(db); mqtt3_log_init(db->config->log_type, db->config->log_dest); flag_reload = false; } if(flag_tree_print){ mqtt3_sub_tree_print(&db->subs, 0); flag_tree_print = false; } } if(pollfds) _mosquitto_free(pollfds); return MOSQ_ERR_SUCCESS; }
int main(int argc, char *argv[]) { int *listensock = NULL; int listensock_count = 0; int listensock_index = 0; struct mqtt3_config config; char buf[1024]; int i, j; FILE *pid; int listener_max; int rc; char err[256]; #ifdef WIN32 SYSTEMTIME st; #else struct timeval tv; #endif #if defined(WIN32) || defined(__CYGWIN__) if(argc == 2){ if(!strcmp(argv[1], "run")){ service_run(); return 0; }else if(!strcmp(argv[1], "install")){ service_install(); return 0; }else if(!strcmp(argv[1], "uninstall")){ service_uninstall(); return 0; } } #endif #ifdef WIN32 GetSystemTime(&st); srand(st.wSecond + st.wMilliseconds); #else gettimeofday(&tv, NULL); srand(tv.tv_sec + tv.tv_usec); #endif memset(&int_db, 0, sizeof(struct mosquitto_db)); _mosquitto_net_init(); mqtt3_config_init(&config); rc = mqtt3_config_parse_args(&config, argc, argv); if(rc != MOSQ_ERR_SUCCESS) return rc; int_db.config = &config; if(config.daemon){ #ifndef WIN32 switch(fork()){ case 0: break; case -1: strerror_r(errno, err, 256); _mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Error in fork: %s", err); return 1; default: return MOSQ_ERR_SUCCESS; } #else _mosquitto_log_printf(NULL, MOSQ_LOG_WARNING, "Warning: Can't start in daemon mode in Windows."); #endif } if(config.daemon && config.pid_file){ pid = _mosquitto_fopen(config.pid_file, "wt"); if(pid){ fprintf(pid, "%d", getpid()); fclose(pid); }else{ _mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Error: Unable to write pid file."); return 1; } } rc = drop_privileges(&config); if(rc != MOSQ_ERR_SUCCESS) return rc; rc = mqtt3_db_open(&config, &int_db); if(rc != MOSQ_ERR_SUCCESS){ _mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Error: Couldn't open database."); return rc; } /* Initialise logging only after initialising the database in case we're * logging to topics */ mqtt3_log_init(config.log_type, config.log_dest); _mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "mosquitto version %s (build date %s) starting", VERSION, TIMESTAMP); if(config.config_file){ _mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "Config loaded from %s.", config.config_file); }else{ _mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "Using default config."); } rc = mosquitto_security_module_init(&int_db); if(rc) return rc; rc = mosquitto_security_init(&int_db, false); if(rc) return rc; #ifdef WITH_SYS_TREE if(config.sys_interval > 0){ /* Set static $SYS messages */ snprintf(buf, 1024, "mosquitto version %s", VERSION); mqtt3_db_messages_easy_queue(&int_db, NULL, "$SYS/broker/version", 2, strlen(buf), buf, 1); snprintf(buf, 1024, "%s", TIMESTAMP); mqtt3_db_messages_easy_queue(&int_db, NULL, "$SYS/broker/timestamp", 2, strlen(buf), buf, 1); #ifdef CHANGESET snprintf(buf, 1024, "%s", CHANGESET); mqtt3_db_messages_easy_queue(&int_db, NULL, "$SYS/broker/changeset", 2, strlen(buf), buf, 1); #endif } #endif listener_max = -1; listensock_index = 0; for(i=0; i<config.listener_count; i++){ if(mqtt3_socket_listen(&config.listeners[i])){ _mosquitto_free(int_db.contexts); mqtt3_db_close(&int_db); if(config.pid_file){ remove(config.pid_file); } return 1; } listensock_count += config.listeners[i].sock_count; listensock = _mosquitto_realloc(listensock, sizeof(int)*listensock_count); if(!listensock){ _mosquitto_free(int_db.contexts); mqtt3_db_close(&int_db); if(config.pid_file){ remove(config.pid_file); } return 1; } for(j=0; j<config.listeners[i].sock_count; j++){ if(config.listeners[i].socks[j] == INVALID_SOCKET){ _mosquitto_free(int_db.contexts); mqtt3_db_close(&int_db); if(config.pid_file){ remove(config.pid_file); } return 1; } listensock[listensock_index] = config.listeners[i].socks[j]; if(listensock[listensock_index] > listener_max){ listener_max = listensock[listensock_index]; } listensock_index++; } } signal(SIGINT, handle_sigint); signal(SIGTERM, handle_sigint); #ifdef SIGHUP signal(SIGHUP, handle_sighup); #endif #ifndef WIN32 signal(SIGUSR1, handle_sigusr1); signal(SIGUSR2, handle_sigusr2); signal(SIGPIPE, SIG_IGN); #endif #ifdef WITH_BRIDGE for(i=0; i<config.bridge_count; i++){ if(mqtt3_bridge_new(&int_db, &(config.bridges[i]))){ _mosquitto_log_printf(NULL, MOSQ_LOG_WARNING, "Warning: Unable to connect to bridge %s.", config.bridges[i].name); } } #endif run = 1; rc = mosquitto_main_loop(&int_db, listensock, listensock_count, listener_max); _mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "mosquitto version %s terminating", VERSION); mqtt3_log_close(); #ifdef WITH_PERSISTENCE if(config.persistence){ mqtt3_db_backup(&int_db, true, true); } #endif for(i=0; i<int_db.context_count; i++){ if(int_db.contexts[i]){ mqtt3_context_cleanup(&int_db, int_db.contexts[i], true); } } _mosquitto_free(int_db.contexts); int_db.contexts = NULL; mqtt3_db_close(&int_db); if(listensock){ for(i=0; i<listensock_count; i++){ if(listensock[i] != INVALID_SOCKET){ #ifndef WIN32 close(listensock[i]); #else closesocket(listensock[i]); #endif } } _mosquitto_free(listensock); } mosquitto_security_module_cleanup(&int_db); if(config.pid_file){ remove(config.pid_file); } _mosquitto_net_cleanup(); mqtt3_config_cleanup(int_db.config); return rc; }
int mqtt3_handle_connect(mosquitto_db *db, mqtt3_context *context) { char *protocol_name; uint8_t protocol_version; uint8_t connect_flags; char *client_id; char *will_topic = NULL, *will_message = NULL; uint8_t will, will_retain, will_qos, clean_session; uint8_t username_flag, password_flag; char *username, *password; int i; int rc; /* Don't accept multiple CONNECT commands. */ if(context->core.state != mosq_cs_new) return MOSQ_ERR_PROTOCOL; if(_mosquitto_read_string(&context->core.in_packet, &protocol_name)) return 1; if(!protocol_name){ mqtt3_socket_close(context); return 3; } if(strcmp(protocol_name, PROTOCOL_NAME)){ mqtt3_log_printf(MOSQ_LOG_INFO, "Invalid protocol \"%s\" in CONNECT from %s.", protocol_name, context->address); _mosquitto_free(protocol_name); mqtt3_socket_close(context); return MOSQ_ERR_PROTOCOL; } if(_mosquitto_read_byte(&context->core.in_packet, &protocol_version)) return 1; if(protocol_version != PROTOCOL_VERSION){ mqtt3_log_printf(MOSQ_LOG_INFO, "Invalid protocol version %d in CONNECT from %s.", protocol_version, context->address); _mosquitto_free(protocol_name); mqtt3_raw_connack(context, 1); mqtt3_socket_close(context); return MOSQ_ERR_PROTOCOL; } _mosquitto_free(protocol_name); if(_mosquitto_read_byte(&context->core.in_packet, &connect_flags)) return 1; clean_session = connect_flags & 0x02; will = connect_flags & 0x04; will_qos = (connect_flags & 0x18) >> 3; will_retain = connect_flags & 0x20; username_flag = connect_flags & 0x40; password_flag = connect_flags & 0x80; if(_mosquitto_read_uint16(&context->core.in_packet, &(context->core.keepalive))) return 1; if(_mosquitto_read_string(&context->core.in_packet, &client_id)) return 1; /* Find if this client already has an entry */ for(i=0; i<db->context_count; i++){ if(db->contexts[i] && db->contexts[i]->core.id && !strcmp(db->contexts[i]->core.id, client_id)){ /* Client does match. */ if(db->contexts[i]->core.sock == -1){ /* Client is reconnecting after a disconnect */ /* FIXME - does anything else need to be done here? */ }else{ /* Client is already connected, disconnect old version */ mqtt3_log_printf(MOSQ_LOG_ERR, "Client %s already connected, closing old connection.", client_id); } if(clean_session){ db->contexts[i]->clean_session = true; } mqtt3_context_cleanup(db, db->contexts[i], false); db->contexts[i]->core.state = mosq_cs_connected; db->contexts[i]->address = _mosquitto_strdup(context->address); db->contexts[i]->core.sock = context->core.sock; context->core.sock = -1; context->core.state = mosq_cs_disconnecting; context = db->contexts[i]; break; } } if(connect_flags & 0x04){ context->core.will = malloc(sizeof(struct mosquitto_message)); if(!context->core.will) return MOSQ_ERR_NOMEM; if(_mosquitto_read_string(&context->core.in_packet, &context->core.will->topic)) return 1; if(_mosquitto_read_string(&context->core.in_packet, &will_message)) return 1; if(will_message){ context->core.will->payload = (uint8_t *)will_message; context->core.will->payloadlen = strlen(will_message); }else{ context->core.will->payload = NULL; context->core.will->payloadlen = 0; } context->core.will->qos = will_qos; context->core.will->retain = will_retain; } if(username_flag){ rc = _mosquitto_read_string(&context->core.in_packet, &username); if(rc == MOSQ_ERR_SUCCESS){ if(password_flag){ rc = _mosquitto_read_string(&context->core.in_packet, &password); if(rc == MOSQ_ERR_NOMEM){ return MOSQ_ERR_NOMEM; }else if(rc == MOSQ_ERR_PROTOCOL){ /* Password flag given, but no password. Ignore. */ password_flag = 0; } } }else if(rc == MOSQ_ERR_NOMEM){ return MOSQ_ERR_NOMEM; }else{ /* Username flag given, but no username. Ignore. */ username_flag = 0; } } mqtt3_log_printf(MOSQ_LOG_DEBUG, "Received CONNECT from %s as %s", context->address, client_id); context->core.id = client_id; context->clean_session = clean_session; if(will_topic) _mosquitto_free(will_topic); if(will_message) _mosquitto_free(will_message); context->core.state = mosq_cs_connected; return mqtt3_raw_connack(context, 0); }
int mqtt3_handle_connect(struct mosquitto_db *db, struct mosquitto *context) { char *protocol_name = NULL; uint8_t protocol_version; uint8_t connect_flags; char *client_id = NULL; char *will_payload = NULL, *will_topic = NULL; uint16_t will_payloadlen; struct mosquitto_message *will_struct = NULL; uint8_t will, will_retain, will_qos, clean_session; uint8_t username_flag, password_flag; char *username = NULL, *password = NULL; int rc; int slen; #ifdef WITH_SYS_TREE g_connection_count++; #endif /* Don't accept multiple CONNECT commands. */ if(context->state != mosq_cs_new){//已经connect过了 mqtt3_context_disconnect(db, context); return MOSQ_ERR_PROTOCOL; } //读取开头的协议名称 if(_mosquitto_read_string(&context->in_packet, &protocol_name)){ mqtt3_context_disconnect(db, context); return 1; } if(!protocol_name){ mqtt3_context_disconnect(db, context); return 3; } if(strcmp(protocol_name, PROTOCOL_NAME)){//协议名必须为"MQIsdp" if(db->config->connection_messages == true){ _mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "Invalid protocol \"%s\" in CONNECT from %s.", protocol_name, context->address); } _mosquitto_free(protocol_name); mqtt3_context_disconnect(db, context); return MOSQ_ERR_PROTOCOL; }//协议名只是为了检验是否为"MQIsdp"的,只后就没用啦 _mosquitto_free(protocol_name); if(_mosquitto_read_byte(&context->in_packet, &protocol_version)){//8 个字节的协议号 mqtt3_context_disconnect(db, context); return 1; } if((protocol_version&0x7F) != PROTOCOL_VERSION){//协议名必须是3版本 if(db->config->connection_messages == true){ _mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "Invalid protocol version %d in CONNECT from %s.", protocol_version, context->address); } _mosquitto_send_connack(context, CONNACK_REFUSED_PROTOCOL_VERSION); mqtt3_context_disconnect(db, context); return MOSQ_ERR_PROTOCOL; } if((protocol_version&0x80) == 0x80){//发送这种协议来的,就认为是bridge context->is_bridge = true; } //下面读取各个标志 if(_mosquitto_read_byte(&context->in_packet, &connect_flags)){ mqtt3_context_disconnect(db, context); return 1; } clean_session = connect_flags & 0x02; will = connect_flags & 0x04; will_qos = (connect_flags & 0x18) >> 3; will_retain = connect_flags & 0x20; password_flag = connect_flags & 0x40; username_flag = connect_flags & 0x80; context->clean_session = clean_session; context->ping_t = 0; if(_mosquitto_read_uint16(&context->in_packet, &(context->keepalive))){ mqtt3_context_disconnect(db, context); return 1; } //客户端ID是必须有的,flags无法控制 if(_mosquitto_read_string(&context->in_packet, &client_id)){ mqtt3_context_disconnect(db, context); return 1; } slen = strlen(client_id); #ifdef WITH_STRICT_PROTOCOL if(slen > 23 || slen == 0){ #else if(slen == 0){ #endif _mosquitto_free(client_id); _mosquitto_send_connack(context, CONNACK_REFUSED_IDENTIFIER_REJECTED); mqtt3_context_disconnect(db, context); return 1; } context->id = client_id; client_id = NULL; /* clientid_prefixes check */ if(db->config->clientid_prefixes){//如果配置文件配置了客户端统一前缀clientid_prefixes,那么所有客户端昵称必须一致 if(strncmp(db->config->clientid_prefixes, context->id, strlen(db->config->clientid_prefixes))){ _mosquitto_send_connack(context, CONNACK_REFUSED_NOT_AUTHORIZED); mqtt3_context_disconnect(db, context); return MOSQ_ERR_SUCCESS; } } if(will){//will指的是如果客户端意外断开连接,那么will Message内容的字符串消息会发布到Will Topic指代的地方 //申请一个message结构,待会填充到context->will上面 will_struct = _mosquitto_calloc(1, sizeof(struct mosquitto_message)); if(!will_struct){ mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_NOMEM; goto handle_connect_error; } if(_mosquitto_read_string(&context->in_packet, &will_topic)){ mqtt3_context_disconnect(db, context); rc = 1; goto handle_connect_error; } if(strlen(will_topic) == 0){ /* FIXME - CONNACK_REFUSED_IDENTIFIER_REJECTED not really appropriate here. */ _mosquitto_send_connack(context, CONNACK_REFUSED_IDENTIFIER_REJECTED); mqtt3_context_disconnect(db, context); rc = 1; goto handle_connect_error; } //由于需要记录长度,所以不能一次读取_mosquitto_read_string if(_mosquitto_read_uint16(&context->in_packet, &will_payloadlen)){ mqtt3_context_disconnect(db, context); rc = 1; goto handle_connect_error; } will_payload = _mosquitto_malloc(will_payloadlen); if(!will_payload){ mqtt3_context_disconnect(db, context); rc = 1; goto handle_connect_error; } rc = _mosquitto_read_bytes(&context->in_packet, will_payload, will_payloadlen); if(rc){ mqtt3_context_disconnect(db, context); rc = 1; goto handle_connect_error; } //设置will-topic的相关信息,mqtt3_context_disconnect会用,判断连接不是主动断开的话会Publis一条消息 if(mosquitto_acl_check(db, context, will_topic, MOSQ_ACL_WRITE) != MOSQ_ERR_SUCCESS){ _mosquitto_send_connack(context, CONNACK_REFUSED_NOT_AUTHORIZED); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; } context->will = will_struct; will_struct = NULL ;//设置为空,避免handle_connect_error释放。放到context上面后续释放即可 context->will->topic = will_topic; will_topic = NULL ; if(will_payload){ context->will->payload = will_payload; context->will->payloadlen = will_payloadlen; will_payload = NULL ; }else{ context->will->payload = NULL; context->will->payloadlen = 0; } context->will->qos = will_qos; context->will->retain = will_retain; } if(username_flag){//读取用户名密码 rc = _mosquitto_read_string(&context->in_packet, &username); if(rc == MOSQ_ERR_SUCCESS){ if(password_flag){ rc = _mosquitto_read_string(&context->in_packet, &password); if(rc == MOSQ_ERR_NOMEM){ rc = MOSQ_ERR_NOMEM; goto handle_connect_error; }else if(rc == MOSQ_ERR_PROTOCOL){ /* Password flag given, but no password. Ignore. */ password_flag = 0; } } }else if(rc == MOSQ_ERR_NOMEM){ rc = MOSQ_ERR_NOMEM; goto handle_connect_error; }else{ /* Username flag given, but no username. Ignore. */ username_flag = 0; } } context->username = username; context->password = password; username = NULL; /* Avoid free() in error: below. */ password = NULL; if(username_flag && password_flag){//如果发送了用户名密码,那么进行用户名密码校验 //放入待验证的客户端链表头部 struct _mosquitto_auth_list * tmpauth = _mosquitto_calloc(1, sizeof(struct _mosquitto_auth_list)); if(tmpauth == NULL){ _mosquitto_send_connack(context, CONNACK_REFUSED_SERVER_UNAVAILABLE); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; } context->auth_result = CONNACK_REFUSED_NOT_AUTHORIZED ; pthread_mutex_lock(&db->auth_list_mutex) ; tmpauth->context = context ; tmpauth->next = db->waiting_auth_list ;//如果db->waiting_auth_list为空这里也可以没事的 assert( context->sock != -1) ; db->waiting_auth_list = tmpauth; db->contexts[context->db_index] = NULL ;//暂时将这个链接从contexts中移除出来,待验证完成后,放入finished_auth_list context->db_index = -1 ; pthread_mutex_unlock(&db->auth_list_mutex) ; //rc = mosquitto_unpwd_check(db, context->username, context->password); return MOSQ_ERR_SUCCESS ; } //查看系统是否允许匿名使用 if(!username_flag && db->config->allow_anonymous == false){ _mosquitto_send_connack(context, CONNACK_REFUSED_NOT_AUTHORIZED); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_error; } //没有用户名,那么OK,继续后面的处理 rc = mqtt3_handle_post_check_unpwd( db, context) ; return rc ; handle_connect_error: if(client_id) _mosquitto_free(client_id); if(username) _mosquitto_free(username); if(password) _mosquitto_free(password); if(will_payload) _mosquitto_free(will_payload); if(will_topic) _mosquitto_free(will_topic); if(will_struct) _mosquitto_free(will_struct); return rc; } int try_wakeup_finished_auth_connections( struct mosquitto_db *db ){ int i=0, dbidx = 0 ; struct _mosquitto_auth_list * tofree = NULL; pthread_mutex_lock(&db->auth_list_mutex) ; struct _mosquitto_auth_list * tmpauth = db->finished_auth_list ; db->finished_auth_list = NULL ; while( tmpauth ){ //将链表每个元素还原到contexts数组里面 assert(tmpauth->context->sock != -1); for(i = dbidx ; i < db->context_count; i++){ if(db->contexts[i] == NULL){ db->contexts[i] = tmpauth->context ; break ; } } if( i == db->context_count){ struct mosquitto **tmp_contexts = NULL; tmp_contexts = _mosquitto_realloc(db->contexts, sizeof(struct mosquitto*)*(db->context_count+1)); if(tmp_contexts){ db->context_count += 1; db->contexts = tmp_contexts; db->contexts[i] = tmpauth->context; }else{ //到这里,说明contexts[]数组不够了,而且relloac也失败,怎么办,只能丢掉这个连接了。但是下面并没有return -1,而且还去访问了。是个bug // Out of memory mqtt3_context_cleanup(NULL, tmpauth->context, true); tmpauth = tmpauth->next ; continue ; } } //已经将这个连接放到contexts数组了。下面需要完成验证的后面部分 db->contexts[i]->db_index = i ; mqtt3_handle_post_check_unpwd(db, db->contexts[i]) ; dbidx = i+1 ; tofree = tmpauth ; tmpauth = tmpauth->next ; _mosquitto_free( tofree ) ; } pthread_mutex_unlock(&db->auth_list_mutex) ; return MOSQ_ERR_SUCCESS ; }
int mqtt3_handle_post_check_unpwd( struct mosquitto_db *db, struct mosquitto *context ){ int rc = 0; int i = 0; struct _clientid_index_hash *find_cih; struct _clientid_index_hash *new_cih; struct _mosquitto_acl_user *acl_tail; if(context->auth_result != CONNACK_ACCEPTED){//密码检查失败 _mosquitto_send_connack(context, CONNACK_REFUSED_BAD_USERNAME_PASSWORD); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_SUCCESS; goto handle_connect_post_error; } /* Find if this client already has an entry. This must be done *after* any security checks. */ HASH_FIND_STR(db->clientid_index_hash, context->id, find_cih); if(find_cih){ i = find_cih->db_context_index;//这个客户端在db->contexts[]数组中的位置 /* Found a matching client */ if(db->contexts[i]->sock == -1){//这个肯定是断开连接后重练的 /* Client is reconnecting after a disconnect */ /* FIXME - does anything else need to be done here? */ }else{//这个是肿么回事? /* Client is already connected, disconnect old version */ if(db->config->connection_messages == true){ _mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Client %s already connected, closing old connection.", context->id); } } //清除上一次连接的相关信息,进行初始化,设置为新连接的信息,这里需要考虑离线消息的问题 assert( db->contexts[i] != context ) ; db->contexts[i]->clean_session = context->clean_session; mqtt3_context_cleanup(db, db->contexts[i], false);//可能会关闭多点登陆的旧连接 db->contexts[i]->state = mosq_cs_connected; db->contexts[i]->address = _mosquitto_strdup(context->address); db->contexts[i]->sock = context->sock; db->contexts[i]->listener = context->listener; db->contexts[i]->last_msg_in = mosquitto_time(); db->contexts[i]->last_msg_out = mosquitto_time(); db->contexts[i]->keepalive = context->keepalive; db->contexts[i]->pollfd_index = context->pollfd_index; db->contexts[i]->id = _mosquitto_strdup(context->id); if(context->username){ db->contexts[i]->username = _mosquitto_strdup(context->username); } if(context->password){ db->contexts[i]->password = _mosquitto_strdup(context->password); } _mosquitto_free(context->id);//参考mqtt3_context_cleanup,这里必须设置为空,否则db->clientid_index_hash会在那里被清楚 context->id = NULL; context->sock = -1; context->clean_session = 1 ;//让其待会在mosquitto_main_loop里面被清空 context->state = mosq_cs_disconnecting; //上面这行是什么作用? 这个指针拿掉后,就没了,内存泄露? //不是这样的,因为这个函数的上层调用方式为loop_handle_reads_writes()->_mosquitto_packet_read(db, db->contexts[i]) //也就是这里的context其实是db->contexts数组的某一项,因此这里由于已经知道client_id了,而且其曾经存在于某contexts项 //因此找到那一项后,将context上的数据拷贝到之前的记录中,然后将当前记录设置为sock = -1。state = mosq_cs_disconnecting context = db->contexts[i];//交换使用旧的context if(context->msgs){//旧的连接上还有数据挂着··· //所以需要将状态设置为一个OK的状态,重发上次的数据等,这里要小心重发的问题,别让客户端记录历史数据包 //里面的代码可能有bug mqtt3_db_message_reconnect_reset(context); } } // Add the client ID to the DB hash table here //已经在里面的不需要增加进去了吧,不是,在mqtt3_context_cleanup里面又del掉了···还得加一次 new_cih = _mosquitto_malloc(sizeof(struct _clientid_index_hash)); if(!new_cih){ _mosquitto_log_printf(NULL, MOSQ_LOG_ERR, "Error: Out of memory."); mqtt3_context_disconnect(db, context); rc = MOSQ_ERR_NOMEM; goto handle_connect_post_error; } new_cih->id = context->id; new_cih->db_context_index = context->db_index; HASH_ADD_KEYPTR(hh, db->clientid_index_hash, context->id, strlen(context->id), new_cih); #ifdef WITH_PERSISTENCE if(!context->clean_session){ db->persistence_changes++; } #endif /* Associate user with its ACL, assuming we have ACLs loaded. */ if(db->acl_list){ acl_tail = db->acl_list; while(acl_tail){ if(context->username){ if(acl_tail->username && !strcmp(context->username, acl_tail->username)){ context->acl_list = acl_tail; break; } }else{ if(acl_tail->username == NULL){ context->acl_list = acl_tail; break; } } acl_tail = acl_tail->next; } }else{ context->acl_list = NULL; } if(db->config->connection_messages == true){ _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "New client connected from %s as %s (c%d, k%d).", context->address, context->id, context->clean_session, context->keepalive); } context->state = mosq_cs_connected; //给客户端发送连接成功的CONNACK回包 return _mosquitto_send_connack(context, CONNACK_ACCEPTED); handle_connect_post_error: return rc; }
int mqtt3_socket_accept(struct mosquitto_db *db, int listensock) { int i; int j; int new_sock = -1; struct mosquitto **tmp_contexts = NULL; struct mosquitto *new_context; int opt = 1; new_sock = accept(listensock, NULL, 0); if(new_sock == INVALID_SOCKET) return -1; #ifdef WITH_SYS_TREE g_socket_connections++; #endif /* Set non-blocking */ opt = fcntl(new_sock, F_GETFL, 0); if(opt == -1 || fcntl(new_sock, F_SETFL, opt | O_NONBLOCK) == -1){ /* If either fcntl fails, don't want to allow this client to connect. */ close(new_sock); return -1; } //初始化个跟客户端连接的context,里面会设置客户端的IP地址,这里可以考虑不在里面做,accept的时候参数中完成即可 new_context = mqtt3_context_init(new_sock); if(!new_context){ COMPAT_CLOSE(new_sock); return -1; } for(i=0; i<db->config->listener_count; i++){//循环找每一个listeners,找到我是属于哪个listeners.实际上epoll后就不需要这些东西了 for(j=0; j<db->config->listeners[i].sock_count; j++){ if(db->config->listeners[i].socks[j] == listensock){ new_context->listener = &db->config->listeners[i];//指向我所属的listener break; } } } if(!new_context->listener){ COMPAT_CLOSE(new_sock); return -1; } if(new_context->listener->max_connections > 0 && new_context->listener->client_count >= new_context->listener->max_connections){ _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "Client connection from %s denied: max_connections exceeded.", new_context->address); COMPAT_CLOSE(new_sock); return -1; } _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "New connection from %s on port %d.", new_context->address, new_context->listener->port); for(i=0; i<db->context_count; i++){//找一个空的contexts结构,指向这一个空连接 if(db->contexts[i] == NULL){ db->contexts[i] = new_context; break; } } if(i==db->context_count){//没有了,重新realloc一个,这个代价很大的。所以建议申请2倍,保留一些空余的,到一定程度的时候每次增加32个也行 tmp_contexts = _mosquitto_realloc(db->contexts, sizeof(struct mosquitto*)*(db->context_count+1)); if(tmp_contexts){ db->context_count += 1;//暂时改为一次增长32个,不然每次都realloc很恐怖 db->contexts = tmp_contexts;//这样的话,所有人都不能用指向contexts数组某个位置的指针来标识这个连接,比如放到epoll里面去世不行的 db->contexts[i] = new_context; }else{ //到这里,说明contexts[]数组不够了,而且relloac也失败,怎么办,只能丢掉这个连接了。但是下面并没有return -1,而且还去访问了。是个bug // Out of memory mqtt3_context_cleanup(NULL, new_context, true); return -1 ;//必须return,否则下面会core } } // If we got here then the context's DB index is "i" regardless of how we got here new_context->db_index = i; new_context->listener->client_count++; return new_sock; }