/* Copyright (c) 2001 Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. * Copyright (c) 2007-2018, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file connection.c * \brief General high-level functions to handle reading and writing * on connections. * * Each connection (ideally) represents a TLS connection, a TCP socket, a unix * socket, or a UDP socket on which reads and writes can occur. (But see * connection_edge.c for cases where connections can also represent streams * that do not have a corresponding socket.) * * The module implements the abstract type, connection_t. The subtypes are: * * * The base type implemented in this module is responsible for basic * rate limiting, flow control, and marshalling bytes onto and off of the * network (either directly or via TLS). * * Connections are registered with the main loop with connection_add(). As * they become able to read or write register the fact with the event main * loop by calling connection_watch_events(), connection_start_reading(), or * connection_start_writing(). When they no longer want to read or write, * they call connection_stop_reading() or connection_stop_writing(). * * To queue data to be written on a connection, call * connection_buf_add(). When data arrives, the * connection_process_inbuf() callback is invoked, which dispatches to a * type-specific function (such as connection_edge_process_inbuf() for * example). Connection types that need notice of when data has been written * receive notification via connection_flushed_some() and * connection_finished_flushing(). These functions all delegate to * type-specific implementations. * * Additionally, beyond the core of connection_t, this module also implements: * **/ #define CONNECTION_PRIVATE #include "or/or.h" #include "or/bridges.h" #include "lib/container/buffers.h" #include "lib/tls/buffers_tls.h" /* * Define this so we get channel internal functions, since we're implementing * part of a subclass (channel_tls_t). */ #define TOR_CHANNEL_INTERNAL_ #define CONNECTION_PRIVATE #include "lib/err/backtrace.h" #include "or/channel.h" #include "or/channeltls.h" #include "or/circuitbuild.h" #include "or/circuitlist.h" #include "or/circuituse.h" #include "or/config.h" #include "or/connection.h" #include "or/connection_edge.h" #include "or/connection_or.h" #include "or/control.h" #include "lib/crypt_ops/crypto_util.h" #include "or/directory.h" #include "or/dirserv.h" #include "or/dns.h" #include "or/dnsserv.h" #include "or/dos.h" #include "or/entrynodes.h" #include "or/ext_orport.h" #include "or/geoip.h" #include "or/main.h" #include "or/hibernate.h" #include "or/hs_common.h" #include "or/hs_ident.h" #include "or/nodelist.h" #include "or/proto_http.h" #include "or/proto_socks.h" #include "or/policies.h" #include "or/reasons.h" #include "or/relay.h" #include "or/rendclient.h" #include "or/rendcommon.h" #include "or/rephist.h" #include "or/router.h" #include "or/routerlist.h" #include "or/transports.h" #include "or/routerparse.h" #include "lib/sandbox/sandbox.h" #include "lib/net/buffers_net.h" #include "lib/tls/tortls.h" #include "lib/evloop/compat_libevent.h" #include "lib/compress/compress.h" #ifdef HAVE_PWD_H #include #endif #ifdef HAVE_UNISTD_H #include #endif #ifdef HAVE_SYS_STAT_H #include #endif #ifdef HAVE_SYS_UN_H #include #include #endif #include "or/dir_connection_st.h" #include "or/control_connection_st.h" #include "or/entry_connection_st.h" #include "or/listener_connection_st.h" #include "or/or_connection_st.h" #include "or/port_cfg_st.h" #include "or/routerinfo_st.h" #include "or/socks_request_st.h" static connection_t *connection_listener_new( const struct sockaddr *listensockaddr, socklen_t listensocklen, int type, const char *address, const port_cfg_t *portcfg); static void connection_init(time_t now, connection_t *conn, int type, int socket_family); static int connection_handle_listener_read(connection_t *conn, int new_type); static int connection_finished_flushing(connection_t *conn); static int connection_flushed_some(connection_t *conn); static int connection_finished_connecting(connection_t *conn); static int connection_reached_eof(connection_t *conn); static int connection_buf_read_from_socket(connection_t *conn, ssize_t *max_to_read, int *socket_error); static int connection_process_inbuf(connection_t *conn, int package_partial); static void client_check_address_changed(tor_socket_t sock); static void set_constrained_socket_buffers(tor_socket_t sock, int size); static const char *connection_proxy_state_to_string(int state); static int connection_read_https_proxy_response(connection_t *conn); static void connection_send_socks5_connect(connection_t *conn); static const char *proxy_type_to_string(int proxy_type); static int get_proxy_type(void); const tor_addr_t *conn_get_outbound_address(sa_family_t family, const or_options_t *options, unsigned int conn_type); static void reenable_blocked_connection_init(const or_options_t *options); static void reenable_blocked_connection_schedule(void); /** The last addresses that our network interface seemed to have been * binding to. We use this as one way to detect when our IP changes. * * XXXX+ We should really use the entire list of interfaces here. **/ static tor_addr_t *last_interface_ipv4 = NULL; /* DOCDOC last_interface_ipv6 */ static tor_addr_t *last_interface_ipv6 = NULL; /** A list of tor_addr_t for addresses we've used in outgoing connections. * Used to detect IP address changes. */ static smartlist_t *outgoing_addrs = NULL; #define CASE_ANY_LISTENER_TYPE \ case CONN_TYPE_OR_LISTENER: \ case CONN_TYPE_EXT_OR_LISTENER: \ case CONN_TYPE_AP_LISTENER: \ case CONN_TYPE_DIR_LISTENER: \ case CONN_TYPE_CONTROL_LISTENER: \ case CONN_TYPE_AP_TRANS_LISTENER: \ case CONN_TYPE_AP_NATD_LISTENER: \ case CONN_TYPE_AP_DNS_LISTENER: \ case CONN_TYPE_AP_HTTP_CONNECT_LISTENER /**************************************************************/ /** Convert a connection_t* to an listener_connection_t*; assert if the cast * is invalid. */ listener_connection_t * TO_LISTENER_CONN(connection_t *c) { tor_assert(c->magic == LISTENER_CONNECTION_MAGIC); return DOWNCAST(listener_connection_t, c); } size_t connection_get_inbuf_len(connection_t *conn) { return conn->inbuf ? buf_datalen(conn->inbuf) : 0; } size_t connection_get_outbuf_len(connection_t *conn) { return conn->outbuf ? buf_datalen(conn->outbuf) : 0; } /** * Return the human-readable name for the connection type type */ const char * conn_type_to_string(int type) { static char buf[64]; switch (type) { case CONN_TYPE_OR_LISTENER: return "OR listener"; case CONN_TYPE_OR: return "OR"; case CONN_TYPE_EXIT: return "Exit"; case CONN_TYPE_AP_LISTENER: return "Socks listener"; case CONN_TYPE_AP_TRANS_LISTENER: return "Transparent pf/netfilter listener"; case CONN_TYPE_AP_NATD_LISTENER: return "Transparent natd listener"; case CONN_TYPE_AP_DNS_LISTENER: return "DNS listener"; case CONN_TYPE_AP: return "Socks"; case CONN_TYPE_DIR_LISTENER: return "Directory listener"; case CONN_TYPE_DIR: return "Directory"; case CONN_TYPE_CONTROL_LISTENER: return "Control listener"; case CONN_TYPE_CONTROL: return "Control"; case CONN_TYPE_EXT_OR: return "Extended OR"; case CONN_TYPE_EXT_OR_LISTENER: return "Extended OR listener"; case CONN_TYPE_AP_HTTP_CONNECT_LISTENER: return "HTTP tunnel listener"; default: log_warn(LD_BUG, "unknown connection type %d", type); tor_snprintf(buf, sizeof(buf), "unknown [%d]", type); return buf; } } /** * Return the human-readable name for the connection state state * for the connection type type */ const char * conn_state_to_string(int type, int state) { static char buf[96]; switch (type) { CASE_ANY_LISTENER_TYPE: if (state == LISTENER_STATE_READY) return "ready"; break; case CONN_TYPE_OR: switch (state) { case OR_CONN_STATE_CONNECTING: return "connect()ing"; case OR_CONN_STATE_PROXY_HANDSHAKING: return "handshaking (proxy)"; case OR_CONN_STATE_TLS_HANDSHAKING: return "handshaking (TLS)"; case OR_CONN_STATE_TLS_CLIENT_RENEGOTIATING: return "renegotiating (TLS, v2 handshake)"; case OR_CONN_STATE_TLS_SERVER_RENEGOTIATING: return "waiting for renegotiation or V3 handshake"; case OR_CONN_STATE_OR_HANDSHAKING_V2: return "handshaking (Tor, v2 handshake)"; case OR_CONN_STATE_OR_HANDSHAKING_V3: return "handshaking (Tor, v3 handshake)"; case OR_CONN_STATE_OPEN: return "open"; } break; case CONN_TYPE_EXT_OR: switch (state) { case EXT_OR_CONN_STATE_AUTH_WAIT_AUTH_TYPE: return "waiting for authentication type"; case EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_NONCE: return "waiting for client nonce"; case EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_HASH: return "waiting for client hash"; case EXT_OR_CONN_STATE_OPEN: return "open"; case EXT_OR_CONN_STATE_FLUSHING: return "flushing final OKAY"; } break; case CONN_TYPE_EXIT: switch (state) { case EXIT_CONN_STATE_RESOLVING: return "waiting for dest info"; case EXIT_CONN_STATE_CONNECTING: return "connecting"; case EXIT_CONN_STATE_OPEN: return "open"; case EXIT_CONN_STATE_RESOLVEFAILED: return "resolve failed"; } break; case CONN_TYPE_AP: switch (state) { case AP_CONN_STATE_SOCKS_WAIT: return "waiting for socks info"; case AP_CONN_STATE_NATD_WAIT: return "waiting for natd dest info"; case AP_CONN_STATE_RENDDESC_WAIT: return "waiting for rendezvous desc"; case AP_CONN_STATE_CONTROLLER_WAIT: return "waiting for controller"; case AP_CONN_STATE_CIRCUIT_WAIT: return "waiting for circuit"; case AP_CONN_STATE_CONNECT_WAIT: return "waiting for connect response"; case AP_CONN_STATE_RESOLVE_WAIT: return "waiting for resolve response"; case AP_CONN_STATE_OPEN: return "open"; } break; case CONN_TYPE_DIR: switch (state) { case DIR_CONN_STATE_CONNECTING: return "connecting"; case DIR_CONN_STATE_CLIENT_SENDING: return "client sending"; case DIR_CONN_STATE_CLIENT_READING: return "client reading"; case DIR_CONN_STATE_CLIENT_FINISHED: return "client finished"; case DIR_CONN_STATE_SERVER_COMMAND_WAIT: return "waiting for command"; case DIR_CONN_STATE_SERVER_WRITING: return "writing"; } break; case CONN_TYPE_CONTROL: switch (state) { case CONTROL_CONN_STATE_OPEN: return "open (protocol v1)"; case CONTROL_CONN_STATE_NEEDAUTH: return "waiting for authentication (protocol v1)"; } break; } log_warn(LD_BUG, "unknown connection state %d (type %d)", state, type); tor_snprintf(buf, sizeof(buf), "unknown state [%d] on unknown [%s] connection", state, conn_type_to_string(type)); return buf; } /** Allocate and return a new dir_connection_t, initialized as by * connection_init(). */ dir_connection_t * dir_connection_new(int socket_family) { dir_connection_t *dir_conn = tor_malloc_zero(sizeof(dir_connection_t)); connection_init(time(NULL), TO_CONN(dir_conn), CONN_TYPE_DIR, socket_family); return dir_conn; } /** Allocate and return a new or_connection_t, initialized as by * connection_init(). * * Initialize active_circuit_pqueue. * * Set active_circuit_pqueue_last_recalibrated to current cell_ewma tick. */ or_connection_t * or_connection_new(int type, int socket_family) { or_connection_t *or_conn = tor_malloc_zero(sizeof(or_connection_t)); time_t now = time(NULL); tor_assert(type == CONN_TYPE_OR || type == CONN_TYPE_EXT_OR); connection_init(now, TO_CONN(or_conn), type, socket_family); connection_or_set_canonical(or_conn, 0); if (type == CONN_TYPE_EXT_OR) connection_or_set_ext_or_identifier(or_conn); return or_conn; } /** Allocate and return a new entry_connection_t, initialized as by * connection_init(). * * Allocate space to store the socks_request. */ entry_connection_t * entry_connection_new(int type, int socket_family) { entry_connection_t *entry_conn = tor_malloc_zero(sizeof(entry_connection_t)); tor_assert(type == CONN_TYPE_AP); connection_init(time(NULL), ENTRY_TO_CONN(entry_conn), type, socket_family); entry_conn->socks_request = socks_request_new(); /* If this is coming from a listener, we'll set it up based on the listener * in a little while. Otherwise, we're doing this as a linked connection * of some kind, and we should set it up here based on the socket family */ if (socket_family == AF_INET) entry_conn->entry_cfg.ipv4_traffic = 1; else if (socket_family == AF_INET6) entry_conn->entry_cfg.ipv6_traffic = 1; return entry_conn; } /** Allocate and return a new edge_connection_t, initialized as by * connection_init(). */ edge_connection_t * edge_connection_new(int type, int socket_family) { edge_connection_t *edge_conn = tor_malloc_zero(sizeof(edge_connection_t)); tor_assert(type == CONN_TYPE_EXIT); connection_init(time(NULL), TO_CONN(edge_conn), type, socket_family); return edge_conn; } /** Allocate and return a new control_connection_t, initialized as by * connection_init(). */ control_connection_t * control_connection_new(int socket_family) { control_connection_t *control_conn = tor_malloc_zero(sizeof(control_connection_t)); connection_init(time(NULL), TO_CONN(control_conn), CONN_TYPE_CONTROL, socket_family); return control_conn; } /** Allocate and return a new listener_connection_t, initialized as by * connection_init(). */ listener_connection_t * listener_connection_new(int type, int socket_family) { listener_connection_t *listener_conn = tor_malloc_zero(sizeof(listener_connection_t)); connection_init(time(NULL), TO_CONN(listener_conn), type, socket_family); return listener_conn; } /** Allocate, initialize, and return a new connection_t subtype of type * to make or receive connections of address family socket_family. The * type should be one of the CONN_TYPE_* constants. */ connection_t * connection_new(int type, int socket_family) { switch (type) { case CONN_TYPE_OR: case CONN_TYPE_EXT_OR: return TO_CONN(or_connection_new(type, socket_family)); case CONN_TYPE_EXIT: return TO_CONN(edge_connection_new(type, socket_family)); case CONN_TYPE_AP: return ENTRY_TO_CONN(entry_connection_new(type, socket_family)); case CONN_TYPE_DIR: return TO_CONN(dir_connection_new(socket_family)); case CONN_TYPE_CONTROL: return TO_CONN(control_connection_new(socket_family)); CASE_ANY_LISTENER_TYPE: return TO_CONN(listener_connection_new(type, socket_family)); default: { connection_t *conn = tor_malloc_zero(sizeof(connection_t)); connection_init(time(NULL), conn, type, socket_family); return conn; } } } /** Initializes conn. (you must call connection_add() to link it into the main * array). * * Set conn-\>magic to the correct value. * * Set conn-\>type to type. Set conn-\>s and conn-\>conn_array_index to * -1 to signify they are not yet assigned. * * Initialize conn's timestamps to now. */ static void connection_init(time_t now, connection_t *conn, int type, int socket_family) { static uint64_t n_connections_allocated = 1; switch (type) { case CONN_TYPE_OR: case CONN_TYPE_EXT_OR: conn->magic = OR_CONNECTION_MAGIC; break; case CONN_TYPE_EXIT: conn->magic = EDGE_CONNECTION_MAGIC; break; case CONN_TYPE_AP: conn->magic = ENTRY_CONNECTION_MAGIC; break; case CONN_TYPE_DIR: conn->magic = DIR_CONNECTION_MAGIC; break; case CONN_TYPE_CONTROL: conn->magic = CONTROL_CONNECTION_MAGIC; break; CASE_ANY_LISTENER_TYPE: conn->magic = LISTENER_CONNECTION_MAGIC; break; default: conn->magic = BASE_CONNECTION_MAGIC; break; } conn->s = TOR_INVALID_SOCKET; /* give it a default of 'not used' */ conn->conn_array_index = -1; /* also default to 'not used' */ conn->global_identifier = n_connections_allocated++; conn->type = type; conn->socket_family = socket_family; if (!connection_is_listener(conn)) { /* listeners never use their buf */ conn->inbuf = buf_new(); conn->outbuf = buf_new(); } conn->timestamp_created = now; conn->timestamp_last_read_allowed = now; conn->timestamp_last_write_allowed = now; } /** Create a link between conn_a and conn_b. */ void connection_link_connections(connection_t *conn_a, connection_t *conn_b) { tor_assert(! SOCKET_OK(conn_a->s)); tor_assert(! SOCKET_OK(conn_b->s)); conn_a->linked = 1; conn_b->linked = 1; conn_a->linked_conn = conn_b; conn_b->linked_conn = conn_a; } /** Return true iff the provided connection listener type supports AF_UNIX * sockets. */ int conn_listener_type_supports_af_unix(int type) { /* For now only control ports or SOCKS ports can be Unix domain sockets * and listeners at the same time */ switch (type) { case CONN_TYPE_CONTROL_LISTENER: case CONN_TYPE_AP_LISTENER: return 1; default: return 0; } } /** Deallocate memory used by conn. Deallocate its buffers if * necessary, close its socket if necessary, and mark the directory as dirty * if conn is an OR or OP connection. */ STATIC void connection_free_minimal(connection_t *conn) { void *mem; size_t memlen; if (!conn) return; switch (conn->type) { case CONN_TYPE_OR: case CONN_TYPE_EXT_OR: tor_assert(conn->magic == OR_CONNECTION_MAGIC); mem = TO_OR_CONN(conn); memlen = sizeof(or_connection_t); break; case CONN_TYPE_AP: tor_assert(conn->magic == ENTRY_CONNECTION_MAGIC); mem = TO_ENTRY_CONN(conn); memlen = sizeof(entry_connection_t); break; case CONN_TYPE_EXIT: tor_assert(conn->magic == EDGE_CONNECTION_MAGIC); mem = TO_EDGE_CONN(conn); memlen = sizeof(edge_connection_t); break; case CONN_TYPE_DIR: tor_assert(conn->magic == DIR_CONNECTION_MAGIC); mem = TO_DIR_CONN(conn); memlen = sizeof(dir_connection_t); break; case CONN_TYPE_CONTROL: tor_assert(conn->magic == CONTROL_CONNECTION_MAGIC); mem = TO_CONTROL_CONN(conn); memlen = sizeof(control_connection_t); break; CASE_ANY_LISTENER_TYPE: tor_assert(conn->magic == LISTENER_CONNECTION_MAGIC); mem = TO_LISTENER_CONN(conn); memlen = sizeof(listener_connection_t); break; default: tor_assert(conn->magic == BASE_CONNECTION_MAGIC); mem = conn; memlen = sizeof(connection_t); break; } if (conn->linked) { log_info(LD_GENERAL, "Freeing linked %s connection [%s] with %d " "bytes on inbuf, %d on outbuf.", conn_type_to_string(conn->type), conn_state_to_string(conn->type, conn->state), (int)connection_get_inbuf_len(conn), (int)connection_get_outbuf_len(conn)); } if (!connection_is_listener(conn)) { buf_free(conn->inbuf); buf_free(conn->outbuf); } else { if (conn->socket_family == AF_UNIX) { /* For now only control and SOCKS ports can be Unix domain sockets * and listeners at the same time */ tor_assert(conn_listener_type_supports_af_unix(conn->type)); if (unlink(conn->address) < 0 && errno != ENOENT) { log_warn(LD_NET, "Could not unlink %s: %s", conn->address, strerror(errno)); } } } tor_free(conn->address); if (connection_speaks_cells(conn)) { or_connection_t *or_conn = TO_OR_CONN(conn); tor_tls_free(or_conn->tls); or_conn->tls = NULL; or_handshake_state_free(or_conn->handshake_state); or_conn->handshake_state = NULL; tor_free(or_conn->nickname); if (or_conn->chan) { /* Owww, this shouldn't happen, but... */ log_info(LD_CHANNEL, "Freeing orconn at %p, saw channel %p with ID " "%"PRIu64 " left un-NULLed", or_conn, TLS_CHAN_TO_BASE(or_conn->chan), ( TLS_CHAN_TO_BASE(or_conn->chan)->global_identifier)); if (!CHANNEL_FINISHED(TLS_CHAN_TO_BASE(or_conn->chan))) { channel_close_for_error(TLS_CHAN_TO_BASE(or_conn->chan)); } or_conn->chan->conn = NULL; or_conn->chan = NULL; } } if (conn->type == CONN_TYPE_AP) { entry_connection_t *entry_conn = TO_ENTRY_CONN(conn); tor_free(entry_conn->chosen_exit_name); tor_free(entry_conn->original_dest_address); if (entry_conn->socks_request) socks_request_free(entry_conn->socks_request); if (entry_conn->pending_optimistic_data) { buf_free(entry_conn->pending_optimistic_data); } if (entry_conn->sending_optimistic_data) { buf_free(entry_conn->sending_optimistic_data); } } if (CONN_IS_EDGE(conn)) { rend_data_free(TO_EDGE_CONN(conn)->rend_data); hs_ident_edge_conn_free(TO_EDGE_CONN(conn)->hs_ident); } if (conn->type == CONN_TYPE_CONTROL) { control_connection_t *control_conn = TO_CONTROL_CONN(conn); tor_free(control_conn->safecookie_client_hash); tor_free(control_conn->incoming_cmd); if (control_conn->ephemeral_onion_services) { SMARTLIST_FOREACH(control_conn->ephemeral_onion_services, char *, cp, { memwipe(cp, 0, strlen(cp)); tor_free(cp); }); smartlist_free(control_conn->ephemeral_onion_services); } } /* Probably already freed by connection_free. */ tor_event_free(conn->read_event); tor_event_free(conn->write_event); conn->read_event = conn->write_event = NULL; if (conn->type == CONN_TYPE_DIR) { dir_connection_t *dir_conn = TO_DIR_CONN(conn); tor_free(dir_conn->requested_resource); tor_compress_free(dir_conn->compress_state); if (dir_conn->spool) { SMARTLIST_FOREACH(dir_conn->spool, spooled_resource_t *, spooled, spooled_resource_free(spooled)); smartlist_free(dir_conn->spool); } rend_data_free(dir_conn->rend_data); hs_ident_dir_conn_free(dir_conn->hs_ident); if (dir_conn->guard_state) { /* Cancel before freeing, if it's still there. */ entry_guard_cancel(&dir_conn->guard_state); } circuit_guard_state_free(dir_conn->guard_state); } if (SOCKET_OK(conn->s)) { log_debug(LD_NET,"closing fd %d.",(int)conn->s); tor_close_socket(conn->s); conn->s = TOR_INVALID_SOCKET; } if (conn->type == CONN_TYPE_OR && !tor_digest_is_zero(TO_OR_CONN(conn)->identity_digest)) { log_warn(LD_BUG, "called on OR conn with non-zeroed identity_digest"); connection_or_clear_identity(TO_OR_CONN(conn)); } if (conn->type == CONN_TYPE_OR || conn->type == CONN_TYPE_EXT_OR) { connection_or_remove_from_ext_or_id_map(TO_OR_CONN(conn)); tor_free(TO_OR_CONN(conn)->ext_or_conn_id); tor_free(TO_OR_CONN(conn)->ext_or_auth_correct_client_hash); tor_free(TO_OR_CONN(conn)->ext_or_transport); } memwipe(mem, 0xCC, memlen); /* poison memory */ tor_free(mem); } /** Make sure conn isn't in any of the global conn lists; then free it. */ MOCK_IMPL(void, connection_free_,(connection_t *conn)) { if (!conn) return; tor_assert(!connection_is_on_closeable_list(conn)); tor_assert(!connection_in_array(conn)); if (BUG(conn->linked_conn)) { conn->linked_conn->linked_conn = NULL; if (! conn->linked_conn->marked_for_close && conn->linked_conn->reading_from_linked_conn) connection_start_reading(conn->linked_conn); conn->linked_conn = NULL; } if (connection_speaks_cells(conn)) { if (!tor_digest_is_zero(TO_OR_CONN(conn)->identity_digest)) { connection_or_clear_identity(TO_OR_CONN(conn)); } } if (conn->type == CONN_TYPE_CONTROL) { connection_control_closed(TO_CONTROL_CONN(conn)); } #if 1 /* DEBUGGING */ if (conn->type == CONN_TYPE_AP) { connection_ap_warn_and_unmark_if_pending_circ(TO_ENTRY_CONN(conn), "connection_free"); } #endif /* 1 */ /* Notify the circuit creation DoS mitigation subsystem that an OR client * connection has been closed. And only do that if we track it. */ if (conn->type == CONN_TYPE_OR) { dos_close_client_conn(TO_OR_CONN(conn)); } connection_unregister_events(conn); connection_free_minimal(conn); } /** * Called when we're about to finally unlink and free a connection: * perform necessary accounting and cleanup * - Directory conns that failed to fetch a rendezvous descriptor * need to inform pending rendezvous streams. * - OR conns need to call rep_hist_note_*() to record status. * - AP conns need to send a socks reject if necessary. * - Exit conns need to call connection_dns_remove() if necessary. * - AP and Exit conns need to send an end cell if they can. * - DNS conns need to fail any resolves that are pending on them. * - OR and edge connections need to be unlinked from circuits. */ void connection_about_to_close_connection(connection_t *conn) { tor_assert(conn->marked_for_close); switch (conn->type) { case CONN_TYPE_DIR: connection_dir_about_to_close(TO_DIR_CONN(conn)); break; case CONN_TYPE_OR: case CONN_TYPE_EXT_OR: connection_or_about_to_close(TO_OR_CONN(conn)); break; case CONN_TYPE_AP: connection_ap_about_to_close(TO_ENTRY_CONN(conn)); break; case CONN_TYPE_EXIT: connection_exit_about_to_close(TO_EDGE_CONN(conn)); break; } } /** Return true iff connection_close_immediate() has been called on this * connection. */ #define CONN_IS_CLOSED(c) \ ((c)->linked ? ((c)->linked_conn_is_closed) : (! SOCKET_OK(c->s))) /** Close the underlying socket for conn, so we don't try to * flush it. Must be used in conjunction with (right before) * connection_mark_for_close(). */ void connection_close_immediate(connection_t *conn) { assert_connection_ok(conn,0); if (CONN_IS_CLOSED(conn)) { log_err(LD_BUG,"Attempt to close already-closed connection."); tor_fragile_assert(); return; } if (conn->outbuf_flushlen) { log_info(LD_NET,"fd %d, type %s, state %s, %d bytes on outbuf.", (int)conn->s, conn_type_to_string(conn->type), conn_state_to_string(conn->type, conn->state), (int)conn->outbuf_flushlen); } connection_unregister_events(conn); /* Prevent the event from getting unblocked. */ conn->read_blocked_on_bw = 0; conn->write_blocked_on_bw = 0; if (SOCKET_OK(conn->s)) tor_close_socket(conn->s); conn->s = TOR_INVALID_SOCKET; if (conn->linked) conn->linked_conn_is_closed = 1; if (conn->outbuf) buf_clear(conn->outbuf); conn->outbuf_flushlen = 0; } /** Mark conn to be closed next time we loop through * conn_close_if_marked() in main.c. */ void connection_mark_for_close_(connection_t *conn, int line, const char *file) { assert_connection_ok(conn,0); tor_assert(line); tor_assert(line < 1<<16); /* marked_for_close can only fit a uint16_t. */ tor_assert(file); if (conn->type == CONN_TYPE_OR) { /* * An or_connection should have been closed through one of the channel- * aware functions in connection_or.c. We'll assume this is an error * close and do that, and log a bug warning. */ log_warn(LD_CHANNEL | LD_BUG, "Something tried to close an or_connection_t without going " "through channels at %s:%d", file, line); connection_or_close_for_error(TO_OR_CONN(conn), 0); } else { /* Pass it down to the real function */ connection_mark_for_close_internal_(conn, line, file); } } /** Mark conn to be closed next time we loop through * conn_close_if_marked() in main.c; the _internal version bypasses the * CONN_TYPE_OR checks; this should be called when you either are sure that * if this is an or_connection_t the controlling channel has been notified * (e.g. with connection_or_notify_error()), or you actually are the * connection_or_close_for_error() or connection_or_close_normally() function. * For all other cases, use connection_mark_and_flush() instead, which * checks for or_connection_t properly, instead. See below. */ MOCK_IMPL(void, connection_mark_for_close_internal_, (connection_t *conn, int line, const char *file)) { assert_connection_ok(conn,0); tor_assert(line); tor_assert(line < 1<<16); /* marked_for_close can only fit a uint16_t. */ tor_assert(file); if (conn->marked_for_close) { log_warn(LD_BUG,"Duplicate call to connection_mark_for_close at %s:%d" " (first at %s:%d)", file, line, conn->marked_for_close_file, conn->marked_for_close); tor_fragile_assert(); return; } if (conn->type == CONN_TYPE_OR) { /* * Bad news if this happens without telling the controlling channel; do * this so we can find things that call this wrongly when the asserts hit. */ log_debug(LD_CHANNEL, "Calling connection_mark_for_close_internal_() on an OR conn " "at %s:%d", file, line); } conn->marked_for_close = line; conn->marked_for_close_file = file; add_connection_to_closeable_list(conn); /* in case we're going to be held-open-til-flushed, reset * the number of seconds since last successful write, so * we get our whole 15 seconds */ conn->timestamp_last_write_allowed = time(NULL); } /** Find each connection that has hold_open_until_flushed set to * 1 but hasn't written in the past 15 seconds, and set * hold_open_until_flushed to 0. This means it will get cleaned * up in the next loop through close_if_marked() in main.c. */ void connection_expire_held_open(void) { time_t now; smartlist_t *conns = get_connection_array(); now = time(NULL); SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) { /* If we've been holding the connection open, but we haven't written * for 15 seconds... */ if (conn->hold_open_until_flushed) { tor_assert(conn->marked_for_close); if (now - conn->timestamp_last_write_allowed >= 15) { int severity; if (conn->type == CONN_TYPE_EXIT || (conn->type == CONN_TYPE_DIR && conn->purpose == DIR_PURPOSE_SERVER)) severity = LOG_INFO; else severity = LOG_NOTICE; log_fn(severity, LD_NET, "Giving up on marked_for_close conn that's been flushing " "for 15s (fd %d, type %s, state %s).", (int)conn->s, conn_type_to_string(conn->type), conn_state_to_string(conn->type, conn->state)); conn->hold_open_until_flushed = 0; } } } SMARTLIST_FOREACH_END(conn); } #if defined(HAVE_SYS_UN_H) || defined(RUNNING_DOXYGEN) /** Create an AF_UNIX listenaddr struct. * listenaddress provides the path to the Unix socket. * * Eventually listenaddress will also optionally contain user, group, * and file permissions for the new socket. But not yet. XXX * Also, since we do not create the socket here the information doesn't help * here. * * If not NULL readable_address will contain a copy of the path part of * listenaddress. * * The listenaddr struct has to be freed by the caller. */ static struct sockaddr_un * create_unix_sockaddr(const char *listenaddress, char **readable_address, socklen_t *len_out) { struct sockaddr_un *sockaddr = NULL; sockaddr = tor_malloc_zero(sizeof(struct sockaddr_un)); sockaddr->sun_family = AF_UNIX; if (strlcpy(sockaddr->sun_path, listenaddress, sizeof(sockaddr->sun_path)) >= sizeof(sockaddr->sun_path)) { log_warn(LD_CONFIG, "Unix socket path '%s' is too long to fit.", escaped(listenaddress)); tor_free(sockaddr); return NULL; } if (readable_address) *readable_address = tor_strdup(listenaddress); *len_out = sizeof(struct sockaddr_un); return sockaddr; } #else /* !(defined(HAVE_SYS_UN_H) || defined(RUNNING_DOXYGEN)) */ static struct sockaddr * create_unix_sockaddr(const char *listenaddress, char **readable_address, socklen_t *len_out) { (void)listenaddress; (void)readable_address; log_fn(LOG_ERR, LD_BUG, "Unix domain sockets not supported, yet we tried to create one."); *len_out = 0; tor_fragile_assert(); return NULL; } #endif /* defined(HAVE_SYS_UN_H) || defined(RUNNING_DOXYGEN) */ /** Warn that an accept or a connect has failed because we're running out of * TCP sockets we can use on current system. Rate-limit these warnings so * that we don't spam the log. */ static void warn_too_many_conns(void) { #define WARN_TOO_MANY_CONNS_INTERVAL (6*60*60) static ratelim_t last_warned = RATELIM_INIT(WARN_TOO_MANY_CONNS_INTERVAL); char *m; if ((m = rate_limit_log(&last_warned, approx_time()))) { int n_conns = get_n_open_sockets(); log_warn(LD_NET,"Failing because we have %d connections already. Please " "read doc/TUNING for guidance.%s", n_conns, m); tor_free(m); control_event_general_status(LOG_WARN, "TOO_MANY_CONNECTIONS CURRENT=%d", n_conns); } } #ifdef HAVE_SYS_UN_H #define UNIX_SOCKET_PURPOSE_CONTROL_SOCKET 0 #define UNIX_SOCKET_PURPOSE_SOCKS_SOCKET 1 /** Check if the purpose isn't one of the ones we know what to do with */ static int is_valid_unix_socket_purpose(int purpose) { int valid = 0; switch (purpose) { case UNIX_SOCKET_PURPOSE_CONTROL_SOCKET: case UNIX_SOCKET_PURPOSE_SOCKS_SOCKET: valid = 1; break; } return valid; } /** Return a string description of a unix socket purpose */ static const char * unix_socket_purpose_to_string(int purpose) { const char *s = "unknown-purpose socket"; switch (purpose) { case UNIX_SOCKET_PURPOSE_CONTROL_SOCKET: s = "control socket"; break; case UNIX_SOCKET_PURPOSE_SOCKS_SOCKET: s = "SOCKS socket"; break; } return s; } /** Check whether we should be willing to open an AF_UNIX socket in * path. Return 0 if we should go ahead and -1 if we shouldn't. */ static int check_location_for_unix_socket(const or_options_t *options, const char *path, int purpose, const port_cfg_t *port) { int r = -1; char *p = NULL; tor_assert(is_valid_unix_socket_purpose(purpose)); p = tor_strdup(path); cpd_check_t flags = CPD_CHECK_MODE_ONLY; if (get_parent_directory(p)<0 || p[0] != '/') { log_warn(LD_GENERAL, "Bad unix socket address '%s'. Tor does not support " "relative paths for unix sockets.", path); goto done; } if (port->is_world_writable) { /* World-writable sockets can go anywhere. */ r = 0; goto done; } if (port->is_group_writable) { flags |= CPD_GROUP_OK; } if (port->relax_dirmode_check) { flags |= CPD_RELAX_DIRMODE_CHECK; } if (check_private_dir(p, flags, options->User) < 0) { char *escpath, *escdir; escpath = esc_for_log(path); escdir = esc_for_log(p); log_warn(LD_GENERAL, "Before Tor can create a %s in %s, the directory " "%s needs to exist, and to be accessible only by the user%s " "account that is running Tor. (On some Unix systems, anybody " "who can list a socket can connect to it, so Tor is being " "careful.)", unix_socket_purpose_to_string(purpose), escpath, escdir, port->is_group_writable ? " and group" : ""); tor_free(escpath); tor_free(escdir); goto done; } r = 0; done: tor_free(p); return r; } #endif /* defined(HAVE_SYS_UN_H) */ /** Tell the TCP stack that it shouldn't wait for a long time after * sock has closed before reusing its port. Return 0 on success, * -1 on failure. */ static int make_socket_reuseable(tor_socket_t sock) { #ifdef _WIN32 (void) sock; return 0; #else int one=1; /* REUSEADDR on normal places means you can rebind to the port * right after somebody else has let it go. But REUSEADDR on win32 * means you can bind to the port _even when somebody else * already has it bound_. So, don't do that on Win32. */ if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*) &one, (socklen_t)sizeof(one)) == -1) { return -1; } return 0; #endif /* defined(_WIN32) */ } #ifdef _WIN32 /** Tell the Windows TCP stack to prevent other applications from receiving * traffic from tor's open ports. Return 0 on success, -1 on failure. */ static int make_win32_socket_exclusive(tor_socket_t sock) { #ifdef SO_EXCLUSIVEADDRUSE int one=1; /* Any socket that sets REUSEADDR on win32 can bind to a port _even when * somebody else already has it bound_, and _even if the original socket * didn't set REUSEADDR_. Use EXCLUSIVEADDRUSE to prevent this port-stealing * on win32. */ if (setsockopt(sock, SOL_SOCKET, SO_EXCLUSIVEADDRUSE, (void*) &one, (socklen_t)sizeof(one))) { return -1; } return 0; #else /* !(defined(SO_EXCLUSIVEADDRUSE)) */ (void) sock; return 0; #endif /* defined(SO_EXCLUSIVEADDRUSE) */ } #endif /* defined(_WIN32) */ /** Max backlog to pass to listen. We start at */ static int listen_limit = INT_MAX; /* Listen on fd with appropriate backlog. Return as for listen. */ static int tor_listen(tor_socket_t fd) { int r; if ((r = listen(fd, listen_limit)) < 0) { if (listen_limit == SOMAXCONN) return r; if ((r = listen(fd, SOMAXCONN)) == 0) { listen_limit = SOMAXCONN; log_warn(LD_NET, "Setting listen backlog to INT_MAX connections " "didn't work, but SOMAXCONN did. Lowering backlog limit."); } } return r; } /** Bind a new non-blocking socket listening to the socket described * by listensockaddr. * * address is only used for logging purposes and to add the information * to the conn. */ static connection_t * connection_listener_new(const struct sockaddr *listensockaddr, socklen_t socklen, int type, const char *address, const port_cfg_t *port_cfg) { listener_connection_t *lis_conn; connection_t *conn = NULL; tor_socket_t s = TOR_INVALID_SOCKET; /* the socket we're going to make */ or_options_t const *options = get_options(); (void) options; /* Windows doesn't use this. */ #if defined(HAVE_PWD_H) && defined(HAVE_SYS_UN_H) const struct passwd *pw = NULL; #endif uint16_t usePort = 0, gotPort = 0; int start_reading = 0; static int global_next_session_group = SESSION_GROUP_FIRST_AUTO; tor_addr_t addr; int exhaustion = 0; if (listensockaddr->sa_family == AF_INET || listensockaddr->sa_family == AF_INET6) { int is_stream = (type != CONN_TYPE_AP_DNS_LISTENER); if (is_stream) start_reading = 1; tor_addr_from_sockaddr(&addr, listensockaddr, &usePort); log_notice(LD_NET, "Opening %s on %s", conn_type_to_string(type), fmt_addrport(&addr, usePort)); s = tor_open_socket_nonblocking(tor_addr_family(&addr), is_stream ? SOCK_STREAM : SOCK_DGRAM, is_stream ? IPPROTO_TCP: IPPROTO_UDP); if (!SOCKET_OK(s)) { int e = tor_socket_errno(s); if (ERRNO_IS_RESOURCE_LIMIT(e)) { warn_too_many_conns(); /* * We'll call the OOS handler at the error exit, so set the * exhaustion flag for it. */ exhaustion = 1; } else { log_warn(LD_NET, "Socket creation failed: %s", tor_socket_strerror(e)); } goto err; } if (make_socket_reuseable(s) < 0) { log_warn(LD_NET, "Error setting SO_REUSEADDR flag on %s: %s", conn_type_to_string(type), tor_socket_strerror(errno)); } #ifdef _WIN32 if (make_win32_socket_exclusive(s) < 0) { log_warn(LD_NET, "Error setting SO_EXCLUSIVEADDRUSE flag on %s: %s", conn_type_to_string(type), tor_socket_strerror(errno)); } #endif /* defined(_WIN32) */ #if defined(USE_TRANSPARENT) && defined(IP_TRANSPARENT) if (options->TransProxyType_parsed == TPT_TPROXY && type == CONN_TYPE_AP_TRANS_LISTENER) { int one = 1; if (setsockopt(s, SOL_IP, IP_TRANSPARENT, (void*)&one, (socklen_t)sizeof(one)) < 0) { const char *extra = ""; int e = tor_socket_errno(s); if (e == EPERM) extra = "TransTPROXY requires root privileges or similar" " capabilities."; log_warn(LD_NET, "Error setting IP_TRANSPARENT flag: %s.%s", tor_socket_strerror(e), extra); } } #endif /* defined(USE_TRANSPARENT) && defined(IP_TRANSPARENT) */ #ifdef IPV6_V6ONLY if (listensockaddr->sa_family == AF_INET6) { int one = 1; /* We need to set IPV6_V6ONLY so that this socket can't get used for * IPv4 connections. */ if (setsockopt(s,IPPROTO_IPV6, IPV6_V6ONLY, (void*)&one, (socklen_t)sizeof(one)) < 0) { int e = tor_socket_errno(s); log_warn(LD_NET, "Error setting IPV6_V6ONLY flag: %s", tor_socket_strerror(e)); /* Keep going; probably not harmful. */ } } #endif /* defined(IPV6_V6ONLY) */ if (bind(s,listensockaddr,socklen) < 0) { const char *helpfulhint = ""; int e = tor_socket_errno(s); if (ERRNO_IS_EADDRINUSE(e)) helpfulhint = ". Is Tor already running?"; log_warn(LD_NET, "Could not bind to %s:%u: %s%s", address, usePort, tor_socket_strerror(e), helpfulhint); goto err; } if (is_stream) { if (tor_listen(s) < 0) { log_warn(LD_NET, "Could not listen on %s:%u: %s", address, usePort, tor_socket_strerror(tor_socket_errno(s))); goto err; } } if (usePort != 0) { gotPort = usePort; } else { tor_addr_t addr2; struct sockaddr_storage ss; socklen_t ss_len=sizeof(ss); if (getsockname(s, (struct sockaddr*)&ss, &ss_len)<0) { log_warn(LD_NET, "getsockname() couldn't learn address for %s: %s", conn_type_to_string(type), tor_socket_strerror(tor_socket_errno(s))); gotPort = 0; } tor_addr_from_sockaddr(&addr2, (struct sockaddr*)&ss, &gotPort); } #ifdef HAVE_SYS_UN_H /* * AF_UNIX generic setup stuff */ } else if (listensockaddr->sa_family == AF_UNIX) { /* We want to start reading for both AF_UNIX cases */ start_reading = 1; tor_assert(conn_listener_type_supports_af_unix(type)); if (check_location_for_unix_socket(options, address, (type == CONN_TYPE_CONTROL_LISTENER) ? UNIX_SOCKET_PURPOSE_CONTROL_SOCKET : UNIX_SOCKET_PURPOSE_SOCKS_SOCKET, port_cfg) < 0) { goto err; } log_notice(LD_NET, "Opening %s on %s", conn_type_to_string(type), address); tor_addr_make_unspec(&addr); if (unlink(address) < 0 && errno != ENOENT) { log_warn(LD_NET, "Could not unlink %s: %s", address, strerror(errno)); goto err; } s = tor_open_socket_nonblocking(AF_UNIX, SOCK_STREAM, 0); if (! SOCKET_OK(s)) { int e = tor_socket_errno(s); if (ERRNO_IS_RESOURCE_LIMIT(e)) { warn_too_many_conns(); /* * We'll call the OOS handler at the error exit, so set the * exhaustion flag for it. */ exhaustion = 1; } else { log_warn(LD_NET,"Socket creation failed: %s.", strerror(e)); } goto err; } if (bind(s, listensockaddr, (socklen_t)sizeof(struct sockaddr_un)) == -1) { log_warn(LD_NET,"Bind to %s failed: %s.", address, tor_socket_strerror(tor_socket_errno(s))); goto err; } #ifdef HAVE_PWD_H if (options->User) { pw = tor_getpwnam(options->User); struct stat st; if (pw == NULL) { log_warn(LD_NET,"Unable to chown() %s socket: user %s not found.", address, options->User); goto err; } else if (fstat(s, &st) == 0 && st.st_uid == pw->pw_uid && st.st_gid == pw->pw_gid) { /* No change needed */ } else if (chown(sandbox_intern_string(address), pw->pw_uid, pw->pw_gid) < 0) { log_warn(LD_NET,"Unable to chown() %s socket: %s.", address, strerror(errno)); goto err; } } #endif /* defined(HAVE_PWD_H) */ { unsigned mode; const char *status; struct stat st; if (port_cfg->is_world_writable) { mode = 0666; status = "world-writable"; } else if (port_cfg->is_group_writable) { mode = 0660; status = "group-writable"; } else { mode = 0600; status = "private"; } /* We need to use chmod; fchmod doesn't work on sockets on all * platforms. */ if (fstat(s, &st) == 0 && (st.st_mode & 0777) == mode) { /* no change needed */ } else if (chmod(sandbox_intern_string(address), mode) < 0) { log_warn(LD_FS,"Unable to make %s %s.", address, status); goto err; } } if (listen(s, SOMAXCONN) < 0) { log_warn(LD_NET, "Could not listen on %s: %s", address, tor_socket_strerror(tor_socket_errno(s))); goto err; } #endif /* defined(HAVE_SYS_UN_H) */ } else { log_err(LD_BUG, "Got unexpected address family %d.", listensockaddr->sa_family); tor_assert(0); } lis_conn = listener_connection_new(type, listensockaddr->sa_family); conn = TO_CONN(lis_conn); conn->socket_family = listensockaddr->sa_family; conn->s = s; s = TOR_INVALID_SOCKET; /* Prevent double-close */ conn->address = tor_strdup(address); conn->port = gotPort; tor_addr_copy(&conn->addr, &addr); memcpy(&lis_conn->entry_cfg, &port_cfg->entry_cfg, sizeof(entry_port_cfg_t)); if (port_cfg->entry_cfg.isolation_flags) { lis_conn->entry_cfg.isolation_flags = port_cfg->entry_cfg.isolation_flags; if (port_cfg->entry_cfg.session_group >= 0) { lis_conn->entry_cfg.session_group = port_cfg->entry_cfg.session_group; } else { /* This can wrap after around INT_MAX listeners are opened. But I don't * believe that matters, since you would need to open a ridiculous * number of listeners while keeping the early ones open before you ever * hit this. An OR with a dozen ports open, for example, would have to * close and re-open its listeners every second for 4 years nonstop. */ lis_conn->entry_cfg.session_group = global_next_session_group--; } } if (type != CONN_TYPE_AP_LISTENER) { lis_conn->entry_cfg.ipv4_traffic = 1; lis_conn->entry_cfg.ipv6_traffic = 1; lis_conn->entry_cfg.prefer_ipv6 = 0; } if (connection_add(conn) < 0) { /* no space, forget it */ log_warn(LD_NET,"connection_add for listener failed. Giving up."); goto err; } log_fn(usePort==gotPort ? LOG_DEBUG : LOG_NOTICE, LD_NET, "%s listening on port %u.", conn_type_to_string(type), gotPort); conn->state = LISTENER_STATE_READY; if (start_reading) { connection_start_reading(conn); } else { tor_assert(type == CONN_TYPE_AP_DNS_LISTENER); dnsserv_configure_listener(conn); } /* * Normal exit; call the OOS handler since connection count just changed; * the exhaustion flag will always be zero here though. */ connection_check_oos(get_n_open_sockets(), 0); return conn; err: if (SOCKET_OK(s)) tor_close_socket(s); if (conn) connection_free(conn); /* Call the OOS handler, indicate if we saw an exhaustion-related error */ connection_check_oos(get_n_open_sockets(), exhaustion); return NULL; } /** Do basic sanity checking on a newly received socket. Return 0 * if it looks ok, else return -1. * * Notably, some TCP stacks can erroneously have accept() return successfully * with socklen 0, when the client sends an RST before the accept call (as * nmap does). We want to detect that, and not go on with the connection. */ static int check_sockaddr(const struct sockaddr *sa, int len, int level) { int ok = 1; if (sa->sa_family == AF_INET) { struct sockaddr_in *sin=(struct sockaddr_in*)sa; if (len != sizeof(struct sockaddr_in)) { log_fn(level, LD_NET, "Length of address not as expected: %d vs %d", len,(int)sizeof(struct sockaddr_in)); ok = 0; } if (sin->sin_addr.s_addr == 0 || sin->sin_port == 0) { log_fn(level, LD_NET, "Address for new connection has address/port equal to zero."); ok = 0; } } else if (sa->sa_family == AF_INET6) { struct sockaddr_in6 *sin6=(struct sockaddr_in6*)sa; if (len != sizeof(struct sockaddr_in6)) { log_fn(level, LD_NET, "Length of address not as expected: %d vs %d", len,(int)sizeof(struct sockaddr_in6)); ok = 0; } if (tor_mem_is_zero((void*)sin6->sin6_addr.s6_addr, 16) || sin6->sin6_port == 0) { log_fn(level, LD_NET, "Address for new connection has address/port equal to zero."); ok = 0; } } else if (sa->sa_family == AF_UNIX) { ok = 1; } else { ok = 0; } return ok ? 0 : -1; } /** Check whether the socket family from an accepted socket got is the * same as the one that listener is waiting for. If it isn't, log * a useful message and return -1. Else return 0. * * This is annoying, but can apparently happen on some Darwins. */ static int check_sockaddr_family_match(sa_family_t got, connection_t *listener) { if (got != listener->socket_family) { log_info(LD_BUG, "A listener connection returned a socket with a " "mismatched family. %s for addr_family %d gave us a socket " "with address family %d. Dropping.", conn_type_to_string(listener->type), (int)listener->socket_family, (int)got); return -1; } return 0; } /** The listener connection conn told poll() it wanted to read. * Call accept() on conn-\>s, and add the new connection if necessary. */ static int connection_handle_listener_read(connection_t *conn, int new_type) { tor_socket_t news; /* the new socket */ connection_t *newconn = 0; /* information about the remote peer when connecting to other routers */ struct sockaddr_storage addrbuf; struct sockaddr *remote = (struct sockaddr*)&addrbuf; /* length of the remote address. Must be whatever accept() needs. */ socklen_t remotelen = (socklen_t)sizeof(addrbuf); const or_options_t *options = get_options(); tor_assert((size_t)remotelen >= sizeof(struct sockaddr_in)); memset(&addrbuf, 0, sizeof(addrbuf)); news = tor_accept_socket_nonblocking(conn->s,remote,&remotelen); if (!SOCKET_OK(news)) { /* accept() error */ int e = tor_socket_errno(conn->s); if (ERRNO_IS_ACCEPT_EAGAIN(e)) { /* * they hung up before we could accept(). that's fine. * * give the OOS handler a chance to run though */ connection_check_oos(get_n_open_sockets(), 0); return 0; } else if (ERRNO_IS_RESOURCE_LIMIT(e)) { warn_too_many_conns(); /* Exhaustion; tell the OOS handler */ connection_check_oos(get_n_open_sockets(), 1); return 0; } /* else there was a real error. */ log_warn(LD_NET,"accept() failed: %s. Closing listener.", tor_socket_strerror(e)); connection_mark_for_close(conn); /* Tell the OOS handler about this too */ connection_check_oos(get_n_open_sockets(), 0); return -1; } log_debug(LD_NET, "Connection accepted on socket %d (child of fd %d).", (int)news,(int)conn->s); /* We accepted a new conn; run OOS handler */ connection_check_oos(get_n_open_sockets(), 0); if (make_socket_reuseable(news) < 0) { if (tor_socket_errno(news) == EINVAL) { /* This can happen on OSX if we get a badly timed shutdown. */ log_debug(LD_NET, "make_socket_reuseable returned EINVAL"); } else { log_warn(LD_NET, "Error setting SO_REUSEADDR flag on %s: %s", conn_type_to_string(new_type), tor_socket_strerror(errno)); } tor_close_socket(news); return 0; } if (options->ConstrainedSockets) set_constrained_socket_buffers(news, (int)options->ConstrainedSockSize); if (check_sockaddr_family_match(remote->sa_family, conn) < 0) { tor_close_socket(news); return 0; } if (conn->socket_family == AF_INET || conn->socket_family == AF_INET6 || (conn->socket_family == AF_UNIX && new_type == CONN_TYPE_AP)) { tor_addr_t addr; uint16_t port; if (check_sockaddr(remote, remotelen, LOG_INFO)<0) { log_info(LD_NET, "accept() returned a strange address; closing connection."); tor_close_socket(news); return 0; } tor_addr_from_sockaddr(&addr, remote, &port); /* process entrance policies here, before we even create the connection */ if (new_type == CONN_TYPE_AP) { /* check sockspolicy to see if we should accept it */ if (socks_policy_permits_address(&addr) == 0) { log_notice(LD_APP, "Denying socks connection from untrusted address %s.", fmt_and_decorate_addr(&addr)); tor_close_socket(news); return 0; } } if (new_type == CONN_TYPE_DIR) { /* check dirpolicy to see if we should accept it */ if (dir_policy_permits_address(&addr) == 0) { log_notice(LD_DIRSERV,"Denying dir connection from address %s.", fmt_and_decorate_addr(&addr)); tor_close_socket(news); return 0; } } if (new_type == CONN_TYPE_OR) { /* Assess with the connection DoS mitigation subsystem if this address * can open a new connection. */ if (dos_conn_addr_get_defense_type(&addr) == DOS_CONN_DEFENSE_CLOSE) { tor_close_socket(news); return 0; } } newconn = connection_new(new_type, conn->socket_family); newconn->s = news; /* remember the remote address */ tor_addr_copy(&newconn->addr, &addr); if (new_type == CONN_TYPE_AP && conn->socket_family == AF_UNIX) { newconn->port = 0; newconn->address = tor_strdup(conn->address); } else { newconn->port = port; newconn->address = tor_addr_to_str_dup(&addr); } if (new_type == CONN_TYPE_AP && conn->socket_family != AF_UNIX) { log_info(LD_NET, "New SOCKS connection opened from %s.", fmt_and_decorate_addr(&addr)); } if (new_type == CONN_TYPE_AP && conn->socket_family == AF_UNIX) { log_info(LD_NET, "New SOCKS AF_UNIX connection opened"); } if (new_type == CONN_TYPE_CONTROL) { log_notice(LD_CONTROL, "New control connection opened from %s.", fmt_and_decorate_addr(&addr)); } } else if (conn->socket_family == AF_UNIX && conn->type != CONN_TYPE_AP) { tor_assert(conn->type == CONN_TYPE_CONTROL_LISTENER); tor_assert(new_type == CONN_TYPE_CONTROL); log_notice(LD_CONTROL, "New control connection opened."); newconn = connection_new(new_type, conn->socket_family); newconn->s = news; /* remember the remote address -- do we have anything sane to put here? */ tor_addr_make_unspec(&newconn->addr); newconn->port = 1; newconn->address = tor_strdup(conn->address); } else { tor_assert(0); }; if (connection_add(newconn) < 0) { /* no space, forget it */ connection_free(newconn); return 0; /* no need to tear down the parent */ } if (connection_init_accepted_conn(newconn, TO_LISTENER_CONN(conn)) < 0) { if (! newconn->marked_for_close) connection_mark_for_close(newconn); return 0; } return 0; } /** Initialize states for newly accepted connection conn. * * If conn is an OR, start the TLS handshake. * * If conn is a transparent AP, get its original destination * and place it in circuit_wait. * * The listener parameter is only used for AP connections. */ int connection_init_accepted_conn(connection_t *conn, const listener_connection_t *listener) { int rv; connection_start_reading(conn); switch (conn->type) { case CONN_TYPE_EXT_OR: /* Initiate Extended ORPort authentication. */ return connection_ext_or_start_auth(TO_OR_CONN(conn)); case CONN_TYPE_OR: control_event_or_conn_status(TO_OR_CONN(conn), OR_CONN_EVENT_NEW, 0); rv = connection_tls_start_handshake(TO_OR_CONN(conn), 1); if (rv < 0) { connection_or_close_for_error(TO_OR_CONN(conn), 0); } return rv; break; case CONN_TYPE_AP: memcpy(&TO_ENTRY_CONN(conn)->entry_cfg, &listener->entry_cfg, sizeof(entry_port_cfg_t)); TO_ENTRY_CONN(conn)->nym_epoch = get_signewnym_epoch(); TO_ENTRY_CONN(conn)->socks_request->listener_type = listener->base_.type; switch (TO_CONN(listener)->type) { case CONN_TYPE_AP_LISTENER: conn->state = AP_CONN_STATE_SOCKS_WAIT; TO_ENTRY_CONN(conn)->socks_request->socks_prefer_no_auth = listener->entry_cfg.socks_prefer_no_auth; break; case CONN_TYPE_AP_TRANS_LISTENER: TO_ENTRY_CONN(conn)->is_transparent_ap = 1; /* XXXX028 -- is this correct still, with the addition of * pending_entry_connections ? */ conn->state = AP_CONN_STATE_CIRCUIT_WAIT; return connection_ap_process_transparent(TO_ENTRY_CONN(conn)); case CONN_TYPE_AP_NATD_LISTENER: TO_ENTRY_CONN(conn)->is_transparent_ap = 1; conn->state = AP_CONN_STATE_NATD_WAIT; break; case CONN_TYPE_AP_HTTP_CONNECT_LISTENER: conn->state = AP_CONN_STATE_HTTP_CONNECT_WAIT; } break; case CONN_TYPE_DIR: conn->purpose = DIR_PURPOSE_SERVER; conn->state = DIR_CONN_STATE_SERVER_COMMAND_WAIT; break; case CONN_TYPE_CONTROL: conn->state = CONTROL_CONN_STATE_NEEDAUTH; break; } return 0; } /** Take conn, make a nonblocking socket; try to connect to * sa, binding to bindaddr if sa is not localhost. If fail, return -1 and if * applicable put your best guess about errno into *socket_error. * If connected return 1, if EAGAIN return 0. */ MOCK_IMPL(STATIC int, connection_connect_sockaddr,(connection_t *conn, const struct sockaddr *sa, socklen_t sa_len, const struct sockaddr *bindaddr, socklen_t bindaddr_len, int *socket_error)) { tor_socket_t s; int inprogress = 0; const or_options_t *options = get_options(); tor_assert(conn); tor_assert(sa); tor_assert(socket_error); if (net_is_completely_disabled()) { /* We should never even try to connect anyplace if the network is * completely shut off. * * (We don't check net_is_disabled() here, since we still sometimes * want to open connections when we're in soft hibernation.) */ static ratelim_t disablenet_violated = RATELIM_INIT(30*60); *socket_error = SOCK_ERRNO(ENETUNREACH); log_fn_ratelim(&disablenet_violated, LOG_WARN, LD_BUG, "Tried to open a socket with DisableNetwork set."); tor_fragile_assert(); return -1; } const int protocol_family = sa->sa_family; const int proto = (sa->sa_family == AF_INET6 || sa->sa_family == AF_INET) ? IPPROTO_TCP : 0; s = tor_open_socket_nonblocking(protocol_family, SOCK_STREAM, proto); if (! SOCKET_OK(s)) { /* * Early OOS handler calls; it matters if it's an exhaustion-related * error or not. */ *socket_error = tor_socket_errno(s); if (ERRNO_IS_RESOURCE_LIMIT(*socket_error)) { warn_too_many_conns(); connection_check_oos(get_n_open_sockets(), 1); } else { log_warn(LD_NET,"Error creating network socket: %s", tor_socket_strerror(*socket_error)); connection_check_oos(get_n_open_sockets(), 0); } return -1; } if (make_socket_reuseable(s) < 0) { log_warn(LD_NET, "Error setting SO_REUSEADDR flag on new connection: %s", tor_socket_strerror(errno)); } /* * We've got the socket open; give the OOS handler a chance to check * against configured maximum socket number, but tell it no exhaustion * failure. */ connection_check_oos(get_n_open_sockets(), 0); if (bindaddr && bind(s, bindaddr, bindaddr_len) < 0) { *socket_error = tor_socket_errno(s); log_warn(LD_NET,"Error binding network socket: %s", tor_socket_strerror(*socket_error)); tor_close_socket(s); return -1; } tor_assert(options); if (options->ConstrainedSockets) set_constrained_socket_buffers(s, (int)options->ConstrainedSockSize); if (connect(s, sa, sa_len) < 0) { int e = tor_socket_errno(s); if (!ERRNO_IS_CONN_EINPROGRESS(e)) { /* yuck. kill it. */ *socket_error = e; log_info(LD_NET, "connect() to socket failed: %s", tor_socket_strerror(e)); tor_close_socket(s); return -1; } else { inprogress = 1; } } /* it succeeded. we're connected. */ log_fn(inprogress ? LOG_DEBUG : LOG_INFO, LD_NET, "Connection to socket %s (sock "TOR_SOCKET_T_FORMAT").", inprogress ? "in progress" : "established", s); conn->s = s; if (connection_add_connecting(conn) < 0) { /* no space, forget it */ *socket_error = SOCK_ERRNO(ENOBUFS); return -1; } return inprogress ? 0 : 1; } /* Log a message if connection attempt is made when IPv4 or IPv6 is disabled. * Log a less severe message if we couldn't conform to ClientPreferIPv6ORPort * or ClientPreferIPv6ORPort. */ static void connection_connect_log_client_use_ip_version(const connection_t *conn) { const or_options_t *options = get_options(); /* Only clients care about ClientUseIPv4/6, bail out early on servers, and * on connections we don't care about */ if (server_mode(options) || !conn || conn->type == CONN_TYPE_EXIT) { return; } /* We're only prepared to log OR and DIR connections here */ if (conn->type != CONN_TYPE_OR && conn->type != CONN_TYPE_DIR) { return; } const int must_ipv4 = !fascist_firewall_use_ipv6(options); const int must_ipv6 = (options->ClientUseIPv4 == 0); const int pref_ipv6 = (conn->type == CONN_TYPE_OR ? fascist_firewall_prefer_ipv6_orport(options) : fascist_firewall_prefer_ipv6_dirport(options)); tor_addr_t real_addr; tor_addr_make_null(&real_addr, AF_UNSPEC); /* OR conns keep the original address in real_addr, as addr gets overwritten * with the descriptor address */ if (conn->type == CONN_TYPE_OR) { const or_connection_t *or_conn = TO_OR_CONN((connection_t *)conn); tor_addr_copy(&real_addr, &or_conn->real_addr); } else if (conn->type == CONN_TYPE_DIR) { tor_addr_copy(&real_addr, &conn->addr); } /* Check if we broke a mandatory address family restriction */ if ((must_ipv4 && tor_addr_family(&real_addr) == AF_INET6) || (must_ipv6 && tor_addr_family(&real_addr) == AF_INET)) { static int logged_backtrace = 0; log_info(LD_BUG, "Outgoing %s connection to %s violated ClientUseIPv%s 0.", conn->type == CONN_TYPE_OR ? "OR" : "Dir", fmt_addr(&real_addr), options->ClientUseIPv4 == 0 ? "4" : "6"); if (!logged_backtrace) { log_backtrace(LOG_INFO, LD_BUG, "Address came from"); logged_backtrace = 1; } } /* Bridges are allowed to break IPv4/IPv6 ORPort preferences to connect to * the node's configured address when ClientPreferIPv6ORPort is auto */ if (options->UseBridges && conn->type == CONN_TYPE_OR && options->ClientPreferIPv6ORPort == -1) { return; } /* Check if we couldn't satisfy an address family preference */ if ((!pref_ipv6 && tor_addr_family(&real_addr) == AF_INET6) || (pref_ipv6 && tor_addr_family(&real_addr) == AF_INET)) { log_info(LD_NET, "Outgoing connection to %s doesn't satisfy " "ClientPreferIPv6%sPort %d, with ClientUseIPv4 %d, and " "fascist_firewall_use_ipv6 %d (ClientUseIPv6 %d and UseBridges " "%d).", fmt_addr(&real_addr), conn->type == CONN_TYPE_OR ? "OR" : "Dir", conn->type == CONN_TYPE_OR ? options->ClientPreferIPv6ORPort : options->ClientPreferIPv6DirPort, options->ClientUseIPv4, fascist_firewall_use_ipv6(options), options->ClientUseIPv6, options->UseBridges); } } /** Retrieve the outbound address depending on the protocol (IPv4 or IPv6) * and the connection type (relay, exit, ...) * Return a socket address or NULL in case nothing is configured. **/ const tor_addr_t * conn_get_outbound_address(sa_family_t family, const or_options_t *options, unsigned int conn_type) { const tor_addr_t *ext_addr = NULL; int fam_index; switch (family) { case AF_INET: fam_index = 0; break; case AF_INET6: fam_index = 1; break; default: return NULL; } // If an exit connection, use the exit address (if present) if (conn_type == CONN_TYPE_EXIT) { if (!tor_addr_is_null( &options->OutboundBindAddresses[OUTBOUND_ADDR_EXIT][fam_index])) { ext_addr = &options->OutboundBindAddresses[OUTBOUND_ADDR_EXIT] [fam_index]; } else if (!tor_addr_is_null( &options->OutboundBindAddresses[OUTBOUND_ADDR_EXIT_AND_OR] [fam_index])) { ext_addr = &options->OutboundBindAddresses[OUTBOUND_ADDR_EXIT_AND_OR] [fam_index]; } } else { // All non-exit connections if (!tor_addr_is_null( &options->OutboundBindAddresses[OUTBOUND_ADDR_OR][fam_index])) { ext_addr = &options->OutboundBindAddresses[OUTBOUND_ADDR_OR] [fam_index]; } else if (!tor_addr_is_null( &options->OutboundBindAddresses[OUTBOUND_ADDR_EXIT_AND_OR] [fam_index])) { ext_addr = &options->OutboundBindAddresses[OUTBOUND_ADDR_EXIT_AND_OR] [fam_index]; } } return ext_addr; } /** Take conn, make a nonblocking socket; try to connect to * addr:port (port arrives in *host order*). If fail, return -1 and if * applicable put your best guess about errno into *socket_error. * Else assign s to conn-\>s: if connected return 1, if EAGAIN return 0. * * addr:port can be different to conn->addr:conn->port if connecting through * a proxy. * * address is used to make the logs useful. * * On success, add conn to the list of polled connections. */ int connection_connect(connection_t *conn, const char *address, const tor_addr_t *addr, uint16_t port, int *socket_error) { struct sockaddr_storage addrbuf; struct sockaddr_storage bind_addr_ss; struct sockaddr *bind_addr = NULL; struct sockaddr *dest_addr; int dest_addr_len, bind_addr_len = 0; /* Log if we didn't stick to ClientUseIPv4/6 or ClientPreferIPv6OR/DirPort */ connection_connect_log_client_use_ip_version(conn); if (!tor_addr_is_loopback(addr)) { const tor_addr_t *ext_addr = NULL; ext_addr = conn_get_outbound_address(tor_addr_family(addr), get_options(), conn->type); if (ext_addr) { memset(&bind_addr_ss, 0, sizeof(bind_addr_ss)); bind_addr_len = tor_addr_to_sockaddr(ext_addr, 0, (struct sockaddr *) &bind_addr_ss, sizeof(bind_addr_ss)); if (bind_addr_len == 0) { log_warn(LD_NET, "Error converting OutboundBindAddress %s into sockaddr. " "Ignoring.", fmt_and_decorate_addr(ext_addr)); } else { bind_addr = (struct sockaddr *)&bind_addr_ss; } } } memset(&addrbuf,0,sizeof(addrbuf)); dest_addr = (struct sockaddr*) &addrbuf; dest_addr_len = tor_addr_to_sockaddr(addr, port, dest_addr, sizeof(addrbuf)); tor_assert(dest_addr_len > 0); log_debug(LD_NET, "Connecting to %s:%u.", escaped_safe_str_client(address), port); return connection_connect_sockaddr(conn, dest_addr, dest_addr_len, bind_addr, bind_addr_len, socket_error); } #ifdef HAVE_SYS_UN_H /** Take conn, make a nonblocking socket; try to connect to * an AF_UNIX socket at socket_path. If fail, return -1 and if applicable * put your best guess about errno into *socket_error. Else assign s * to conn-\>s: if connected return 1, if EAGAIN return 0. * * On success, add conn to the list of polled connections. */ int connection_connect_unix(connection_t *conn, const char *socket_path, int *socket_error) { struct sockaddr_un dest_addr; tor_assert(socket_path); /* Check that we'll be able to fit it into dest_addr later */ if (strlen(socket_path) + 1 > sizeof(dest_addr.sun_path)) { log_warn(LD_NET, "Path %s is too long for an AF_UNIX socket\n", escaped_safe_str_client(socket_path)); *socket_error = SOCK_ERRNO(ENAMETOOLONG); return -1; } memset(&dest_addr, 0, sizeof(dest_addr)); dest_addr.sun_family = AF_UNIX; strlcpy(dest_addr.sun_path, socket_path, sizeof(dest_addr.sun_path)); log_debug(LD_NET, "Connecting to AF_UNIX socket at %s.", escaped_safe_str_client(socket_path)); return connection_connect_sockaddr(conn, (struct sockaddr *)&dest_addr, sizeof(dest_addr), NULL, 0, socket_error); } #endif /* defined(HAVE_SYS_UN_H) */ /** Convert state number to string representation for logging purposes. */ static const char * connection_proxy_state_to_string(int state) { static const char *unknown = "???"; static const char *states[] = { "PROXY_NONE", "PROXY_INFANT", "PROXY_HTTPS_WANT_CONNECT_OK", "PROXY_SOCKS4_WANT_CONNECT_OK", "PROXY_SOCKS5_WANT_AUTH_METHOD_NONE", "PROXY_SOCKS5_WANT_AUTH_METHOD_RFC1929", "PROXY_SOCKS5_WANT_AUTH_RFC1929_OK", "PROXY_SOCKS5_WANT_CONNECT_OK", "PROXY_CONNECTED", }; if (state < PROXY_NONE || state > PROXY_CONNECTED) return unknown; return states[state]; } /** Returns the global proxy type used by tor. Use this function for * logging or high-level purposes, don't use it to fill the * proxy_type field of or_connection_t; use the actual proxy * protocol instead.*/ static int get_proxy_type(void) { const or_options_t *options = get_options(); if (options->ClientTransportPlugin) return PROXY_PLUGGABLE; else if (options->HTTPSProxy) return PROXY_CONNECT; else if (options->Socks4Proxy) return PROXY_SOCKS4; else if (options->Socks5Proxy) return PROXY_SOCKS5; else return PROXY_NONE; } /* One byte for the version, one for the command, two for the port, and four for the addr... and, one more for the username NUL: */ #define SOCKS4_STANDARD_BUFFER_SIZE (1 + 1 + 2 + 4 + 1) /** Write a proxy request of type (socks4, socks5, https) to conn * for conn->addr:conn->port, authenticating with the auth details given * in the configuration (if available). SOCKS 5 and HTTP CONNECT proxies * support authentication. * * Returns -1 if conn->addr is incompatible with the proxy protocol, and * 0 otherwise. * * Use connection_read_proxy_handshake() to complete the handshake. */ int connection_proxy_connect(connection_t *conn, int type) { const or_options_t *options; tor_assert(conn); options = get_options(); switch (type) { case PROXY_CONNECT: { char buf[1024]; char *base64_authenticator=NULL; const char *authenticator = options->HTTPSProxyAuthenticator; /* Send HTTP CONNECT and authentication (if available) in * one request */ if (authenticator) { base64_authenticator = alloc_http_authenticator(authenticator); if (!base64_authenticator) log_warn(LD_OR, "Encoding https authenticator failed"); } if (base64_authenticator) { const char *addrport = fmt_addrport(&conn->addr, conn->port); tor_snprintf(buf, sizeof(buf), "CONNECT %s HTTP/1.1\r\n" "Host: %s\r\n" "Proxy-Authorization: Basic %s\r\n\r\n", addrport, addrport, base64_authenticator); tor_free(base64_authenticator); } else { tor_snprintf(buf, sizeof(buf), "CONNECT %s HTTP/1.0\r\n\r\n", fmt_addrport(&conn->addr, conn->port)); } connection_buf_add(buf, strlen(buf), conn); conn->proxy_state = PROXY_HTTPS_WANT_CONNECT_OK; break; } case PROXY_SOCKS4: { unsigned char *buf; uint16_t portn; uint32_t ip4addr; size_t buf_size = 0; char *socks_args_string = NULL; /* Send a SOCKS4 connect request */ if (tor_addr_family(&conn->addr) != AF_INET) { log_warn(LD_NET, "SOCKS4 client is incompatible with IPv6"); return -1; } { /* If we are here because we are trying to connect to a pluggable transport proxy, check if we have any SOCKS arguments to transmit. If we do, compress all arguments to a single string in 'socks_args_string': */ if (get_proxy_type() == PROXY_PLUGGABLE) { socks_args_string = pt_get_socks_args_for_proxy_addrport(&conn->addr, conn->port); if (socks_args_string) log_debug(LD_NET, "Sending out '%s' as our SOCKS argument string.", socks_args_string); } } { /* Figure out the buffer size we need for the SOCKS message: */ buf_size = SOCKS4_STANDARD_BUFFER_SIZE; /* If we have a SOCKS argument string, consider its size when calculating the buffer size: */ if (socks_args_string) buf_size += strlen(socks_args_string); } buf = tor_malloc_zero(buf_size); ip4addr = tor_addr_to_ipv4n(&conn->addr); portn = htons(conn->port); buf[0] = 4; /* version */ buf[1] = SOCKS_COMMAND_CONNECT; /* command */ memcpy(buf + 2, &portn, 2); /* port */ memcpy(buf + 4, &ip4addr, 4); /* addr */ /* Next packet field is the userid. If we have pluggable transport SOCKS arguments, we have to embed them there. Otherwise, we use an empty userid. */ if (socks_args_string) { /* place the SOCKS args string: */ tor_assert(strlen(socks_args_string) > 0); tor_assert(buf_size >= SOCKS4_STANDARD_BUFFER_SIZE + strlen(socks_args_string)); strlcpy((char *)buf + 8, socks_args_string, buf_size - 8); tor_free(socks_args_string); } else { buf[8] = 0; /* no userid */ } connection_buf_add((char *)buf, buf_size, conn); tor_free(buf); conn->proxy_state = PROXY_SOCKS4_WANT_CONNECT_OK; break; } case PROXY_SOCKS5: { unsigned char buf[4]; /* fields: vers, num methods, method list */ /* Send a SOCKS5 greeting (connect request must wait) */ buf[0] = 5; /* version */ /* We have to use SOCKS5 authentication, if we have a Socks5ProxyUsername or if we want to pass arguments to our pluggable transport proxy: */ if ((options->Socks5ProxyUsername) || (get_proxy_type() == PROXY_PLUGGABLE && (get_socks_args_by_bridge_addrport(&conn->addr, conn->port)))) { /* number of auth methods */ buf[1] = 2; buf[2] = 0x00; /* no authentication */ buf[3] = 0x02; /* rfc1929 Username/Passwd auth */ conn->proxy_state = PROXY_SOCKS5_WANT_AUTH_METHOD_RFC1929; } else { buf[1] = 1; buf[2] = 0x00; /* no authentication */ conn->proxy_state = PROXY_SOCKS5_WANT_AUTH_METHOD_NONE; } connection_buf_add((char *)buf, 2 + buf[1], conn); break; } default: log_err(LD_BUG, "Invalid proxy protocol, %d", type); tor_fragile_assert(); return -1; } log_debug(LD_NET, "set state %s", connection_proxy_state_to_string(conn->proxy_state)); return 0; } /** Read conn's inbuf. If the http response from the proxy is all * here, make sure it's good news, then return 1. If it's bad news, * return -1. Else return 0 and hope for better luck next time. */ static int connection_read_https_proxy_response(connection_t *conn) { char *headers; char *reason=NULL; int status_code; time_t date_header; switch (fetch_from_buf_http(conn->inbuf, &headers, MAX_HEADERS_SIZE, NULL, NULL, 10000, 0)) { case -1: /* overflow */ log_warn(LD_PROTOCOL, "Your https proxy sent back an oversized response. Closing."); return -1; case 0: log_info(LD_NET,"https proxy response not all here yet. Waiting."); return 0; /* case 1, fall through */ } if (parse_http_response(headers, &status_code, &date_header, NULL, &reason) < 0) { log_warn(LD_NET, "Unparseable headers from proxy (connecting to '%s'). Closing.", conn->address); tor_free(headers); return -1; } tor_free(headers); if (!reason) reason = tor_strdup("[no reason given]"); if (status_code == 200) { log_info(LD_NET, "HTTPS connect to '%s' successful! (200 %s) Starting TLS.", conn->address, escaped(reason)); tor_free(reason); return 1; } /* else, bad news on the status code */ switch (status_code) { case 403: log_warn(LD_NET, "The https proxy refused to allow connection to %s " "(status code %d, %s). Closing.", conn->address, status_code, escaped(reason)); break; default: log_warn(LD_NET, "The https proxy sent back an unexpected status code %d (%s). " "Closing.", status_code, escaped(reason)); break; } tor_free(reason); return -1; } /** Send SOCKS5 CONNECT command to conn, copying conn->addr * and conn->port into the request. */ static void connection_send_socks5_connect(connection_t *conn) { unsigned char buf[1024]; size_t reqsize = 6; uint16_t port = htons(conn->port); buf[0] = 5; /* version */ buf[1] = SOCKS_COMMAND_CONNECT; /* command */ buf[2] = 0; /* reserved */ if (tor_addr_family(&conn->addr) == AF_INET) { uint32_t addr = tor_addr_to_ipv4n(&conn->addr); buf[3] = 1; reqsize += 4; memcpy(buf + 4, &addr, 4); memcpy(buf + 8, &port, 2); } else { /* AF_INET6 */ buf[3] = 4; reqsize += 16; memcpy(buf + 4, tor_addr_to_in6_addr8(&conn->addr), 16); memcpy(buf + 20, &port, 2); } connection_buf_add((char *)buf, reqsize, conn); conn->proxy_state = PROXY_SOCKS5_WANT_CONNECT_OK; } /** Wrapper around fetch_from_buf_socks_client: see that functions * for documentation of its behavior. */ static int connection_fetch_from_buf_socks_client(connection_t *conn, int state, char **reason) { return fetch_from_buf_socks_client(conn->inbuf, state, reason); } /** Call this from connection_*_process_inbuf() to advance the proxy * handshake. * * No matter what proxy protocol is used, if this function returns 1, the * handshake is complete, and the data remaining on inbuf may contain the * start of the communication with the requested server. * * Returns 0 if the current buffer contains an incomplete response, and -1 * on error. */ int connection_read_proxy_handshake(connection_t *conn) { int ret = 0; char *reason = NULL; log_debug(LD_NET, "enter state %s", connection_proxy_state_to_string(conn->proxy_state)); switch (conn->proxy_state) { case PROXY_HTTPS_WANT_CONNECT_OK: ret = connection_read_https_proxy_response(conn); if (ret == 1) conn->proxy_state = PROXY_CONNECTED; break; case PROXY_SOCKS4_WANT_CONNECT_OK: ret = connection_fetch_from_buf_socks_client(conn, conn->proxy_state, &reason); if (ret == 1) conn->proxy_state = PROXY_CONNECTED; break; case PROXY_SOCKS5_WANT_AUTH_METHOD_NONE: ret = connection_fetch_from_buf_socks_client(conn, conn->proxy_state, &reason); /* no auth needed, do connect */ if (ret == 1) { connection_send_socks5_connect(conn); ret = 0; } break; case PROXY_SOCKS5_WANT_AUTH_METHOD_RFC1929: ret = connection_fetch_from_buf_socks_client(conn, conn->proxy_state, &reason); /* send auth if needed, otherwise do connect */ if (ret == 1) { connection_send_socks5_connect(conn); ret = 0; } else if (ret == 2) { unsigned char buf[1024]; size_t reqsize, usize, psize; const char *user, *pass; char *socks_args_string = NULL; if (get_proxy_type() == PROXY_PLUGGABLE) { socks_args_string = pt_get_socks_args_for_proxy_addrport(&conn->addr, conn->port); if (!socks_args_string) { log_warn(LD_NET, "Could not create SOCKS args string."); ret = -1; break; } log_debug(LD_NET, "SOCKS5 arguments: %s", socks_args_string); tor_assert(strlen(socks_args_string) > 0); tor_assert(strlen(socks_args_string) <= MAX_SOCKS5_AUTH_SIZE_TOTAL); if (strlen(socks_args_string) > MAX_SOCKS5_AUTH_FIELD_SIZE) { user = socks_args_string; usize = MAX_SOCKS5_AUTH_FIELD_SIZE; pass = socks_args_string + MAX_SOCKS5_AUTH_FIELD_SIZE; psize = strlen(socks_args_string) - MAX_SOCKS5_AUTH_FIELD_SIZE; } else { user = socks_args_string; usize = strlen(socks_args_string); pass = "\0"; psize = 1; } } else if (get_options()->Socks5ProxyUsername) { user = get_options()->Socks5ProxyUsername; pass = get_options()->Socks5ProxyPassword; tor_assert(user && pass); usize = strlen(user); psize = strlen(pass); } else { log_err(LD_BUG, "We entered %s for no reason!", __func__); tor_fragile_assert(); ret = -1; break; } /* Username and password lengths should have been checked above and during torrc parsing. */ tor_assert(usize <= MAX_SOCKS5_AUTH_FIELD_SIZE && psize <= MAX_SOCKS5_AUTH_FIELD_SIZE); reqsize = 3 + usize + psize; buf[0] = 1; /* negotiation version */ buf[1] = usize; memcpy(buf + 2, user, usize); buf[2 + usize] = psize; memcpy(buf + 3 + usize, pass, psize); if (socks_args_string) tor_free(socks_args_string); connection_buf_add((char *)buf, reqsize, conn); conn->proxy_state = PROXY_SOCKS5_WANT_AUTH_RFC1929_OK; ret = 0; } break; case PROXY_SOCKS5_WANT_AUTH_RFC1929_OK: ret = connection_fetch_from_buf_socks_client(conn, conn->proxy_state, &reason); /* send the connect request */ if (ret == 1) { connection_send_socks5_connect(conn); ret = 0; } break; case PROXY_SOCKS5_WANT_CONNECT_OK: ret = connection_fetch_from_buf_socks_client(conn, conn->proxy_state, &reason); if (ret == 1) conn->proxy_state = PROXY_CONNECTED; break; default: log_err(LD_BUG, "Invalid proxy_state for reading, %d", conn->proxy_state); tor_fragile_assert(); ret = -1; break; } log_debug(LD_NET, "leaving state %s", connection_proxy_state_to_string(conn->proxy_state)); if (ret < 0) { if (reason) { log_warn(LD_NET, "Proxy Client: unable to connect to %s:%d (%s)", conn->address, conn->port, escaped(reason)); tor_free(reason); } else { log_warn(LD_NET, "Proxy Client: unable to connect to %s:%d", conn->address, conn->port); } } else if (ret == 1) { log_info(LD_NET, "Proxy Client: connection to %s:%d successful", conn->address, conn->port); } return ret; } /** Given a list of listener connections in old_conns, and list of * port_cfg_t entries in ports, open a new listener for every port in * ports that does not already have a listener in old_conns. * * Remove from old_conns every connection that has a corresponding * entry in ports. Add to new_conns new every connection we * launch. * * If control_listeners_only is true, then we only open control * listeners, and we do not remove any noncontrol listeners from old_conns. * * Return 0 on success, -1 on failure. **/ static int retry_listener_ports(smartlist_t *old_conns, const smartlist_t *ports, smartlist_t *new_conns, int control_listeners_only) { smartlist_t *launch = smartlist_new(); int r = 0; if (control_listeners_only) { SMARTLIST_FOREACH(ports, port_cfg_t *, p, { if (p->type == CONN_TYPE_CONTROL_LISTENER) smartlist_add(launch, p); }); } else { smartlist_add_all(launch, ports); } /* Iterate through old_conns, comparing it to launch: remove from both lists * each pair of elements that corresponds to the same port. */ SMARTLIST_FOREACH_BEGIN(old_conns, connection_t *, conn) { const port_cfg_t *found_port = NULL; /* Okay, so this is a listener. Is it configured? */ SMARTLIST_FOREACH_BEGIN(launch, const port_cfg_t *, wanted) { if (conn->type != wanted->type) continue; if ((conn->socket_family != AF_UNIX && wanted->is_unix_addr) || (conn->socket_family == AF_UNIX && ! wanted->is_unix_addr)) continue; if (wanted->server_cfg.no_listen) continue; /* We don't want to open a listener for this one */ if (wanted->is_unix_addr) { if (conn->socket_family == AF_UNIX && !strcmp(wanted->unix_addr, conn->address)) { found_port = wanted; break; } } else { int port_matches; if (wanted->port == CFG_AUTO_PORT) { port_matches = 1; } else { port_matches = (wanted->port == conn->port); } if (port_matches && tor_addr_eq(&wanted->addr, &conn->addr)) { found_port = wanted; break; } } } SMARTLIST_FOREACH_END(wanted); if (found_port) { /* This listener is already running; we don't need to launch it. */ //log_debug(LD_NET, "Already have %s on %s:%d", // conn_type_to_string(found_port->type), conn->address, conn->port); smartlist_remove(launch, found_port); /* And we can remove the connection from old_conns too. */ SMARTLIST_DEL_CURRENT(old_conns, conn); } } SMARTLIST_FOREACH_END(conn); /* Now open all the listeners that are configured but not opened. */ SMARTLIST_FOREACH_BEGIN(launch, const port_cfg_t *, port) { struct sockaddr *listensockaddr; socklen_t listensocklen = 0; char *address=NULL; connection_t *conn; int real_port = port->port == CFG_AUTO_PORT ? 0 : port->port; tor_assert(real_port <= UINT16_MAX); if (port->server_cfg.no_listen) continue; #ifndef _WIN32 /* We don't need to be root to create a UNIX socket, so defer until after * setuid. */ const or_options_t *options = get_options(); if (port->is_unix_addr && !geteuid() && (options->User) && strcmp(options->User, "root")) continue; #endif /* !defined(_WIN32) */ if (port->is_unix_addr) { listensockaddr = (struct sockaddr *) create_unix_sockaddr(port->unix_addr, &address, &listensocklen); } else { listensockaddr = tor_malloc(sizeof(struct sockaddr_storage)); listensocklen = tor_addr_to_sockaddr(&port->addr, real_port, listensockaddr, sizeof(struct sockaddr_storage)); address = tor_addr_to_str_dup(&port->addr); } if (listensockaddr) { conn = connection_listener_new(listensockaddr, listensocklen, port->type, address, port); tor_free(listensockaddr); tor_free(address); } else { conn = NULL; } if (!conn) { r = -1; } else { if (new_conns) smartlist_add(new_conns, conn); } } SMARTLIST_FOREACH_END(port); smartlist_free(launch); return r; } /** Launch listeners for each port you should have open. Only launch * listeners who are not already open, and only close listeners we no longer * want. * * Add all old conns that should be closed to replaced_conns. * Add all new connections to new_conns. * * If close_all_noncontrol is true, then we only open control * listeners, and we close all other listeners. */ int retry_all_listeners(smartlist_t *replaced_conns, smartlist_t *new_conns, int close_all_noncontrol) { smartlist_t *listeners = smartlist_new(); const or_options_t *options = get_options(); int retval = 0; const uint16_t old_or_port = router_get_advertised_or_port(options); const uint16_t old_or_port_ipv6 = router_get_advertised_or_port_by_af(options,AF_INET6); const uint16_t old_dir_port = router_get_advertised_dir_port(options, 0); SMARTLIST_FOREACH_BEGIN(get_connection_array(), connection_t *, conn) { if (connection_is_listener(conn) && !conn->marked_for_close) smartlist_add(listeners, conn); } SMARTLIST_FOREACH_END(conn); if (retry_listener_ports(listeners, get_configured_ports(), new_conns, close_all_noncontrol) < 0) retval = -1; /* Any members that were still in 'listeners' don't correspond to * any configured port. Kill 'em. */ SMARTLIST_FOREACH_BEGIN(listeners, connection_t *, conn) { log_notice(LD_NET, "Closing no-longer-configured %s on %s:%d", conn_type_to_string(conn->type), conn->address, conn->port); if (replaced_conns) { smartlist_add(replaced_conns, conn); } else { connection_close_immediate(conn); connection_mark_for_close(conn); } } SMARTLIST_FOREACH_END(conn); smartlist_free(listeners); if (old_or_port != router_get_advertised_or_port(options) || old_or_port_ipv6 != router_get_advertised_or_port_by_af(options, AF_INET6) || old_dir_port != router_get_advertised_dir_port(options, 0)) { /* Our chosen ORPort or DirPort is not what it used to be: the * descriptor we had (if any) should be regenerated. (We won't * automatically notice this because of changes in the option, * since the value could be "auto".) */ mark_my_descriptor_dirty("Chosen Or/DirPort changed"); } return retval; } /** Mark every listener of type other than CONTROL_LISTENER to be closed. */ void connection_mark_all_noncontrol_listeners(void) { SMARTLIST_FOREACH_BEGIN(get_connection_array(), connection_t *, conn) { if (conn->marked_for_close) continue; if (conn->type == CONN_TYPE_CONTROL_LISTENER) continue; if (connection_is_listener(conn)) connection_mark_for_close(conn); } SMARTLIST_FOREACH_END(conn); } /** Mark every external connection not used for controllers for close. */ void connection_mark_all_noncontrol_connections(void) { SMARTLIST_FOREACH_BEGIN(get_connection_array(), connection_t *, conn) { if (conn->marked_for_close) continue; switch (conn->type) { case CONN_TYPE_CONTROL_LISTENER: case CONN_TYPE_CONTROL: break; case CONN_TYPE_AP: connection_mark_unattached_ap(TO_ENTRY_CONN(conn), END_STREAM_REASON_HIBERNATING); break; case CONN_TYPE_OR: { or_connection_t *orconn = TO_OR_CONN(conn); if (orconn->chan) { connection_or_close_normally(orconn, 0); } else { /* * There should have been one, but mark for close and hope * for the best.. */ connection_mark_for_close(conn); } } break; default: connection_mark_for_close(conn); break; } } SMARTLIST_FOREACH_END(conn); } /** Return 1 if we should apply rate limiting to conn, and 0 * otherwise. * Right now this just checks if it's an internal IP address or an * internal connection. We also should, but don't, check if the connection * uses pluggable transports, since we should then limit it even if it * comes from an internal IP address. */ static int connection_is_rate_limited(connection_t *conn) { const or_options_t *options = get_options(); if (conn->linked) return 0; /* Internal connection */ else if (! options->CountPrivateBandwidth && (tor_addr_family(&conn->addr) == AF_UNSPEC || /* no address */ tor_addr_family(&conn->addr) == AF_UNIX || /* no address */ tor_addr_is_internal(&conn->addr, 0))) return 0; /* Internal address */ else return 1; } /** When was either global write bucket last empty? If this was recent, then * we're probably low on bandwidth, and we should be stingy with our bandwidth * usage. */ static time_t write_buckets_last_empty_at = -100; /** How many seconds of no active local circuits will make the * connection revert to the "relayed" bandwidth class? */ #define CLIENT_IDLE_TIME_FOR_PRIORITY 30 /** Return 1 if conn should use tokens from the "relayed" * bandwidth rates, else 0. Currently, only OR conns with bandwidth * class 1, and directory conns that are serving data out, count. */ static int connection_counts_as_relayed_traffic(connection_t *conn, time_t now) { if (conn->type == CONN_TYPE_OR && connection_or_client_used(TO_OR_CONN(conn)) + CLIENT_IDLE_TIME_FOR_PRIORITY < now) return 1; if (conn->type == CONN_TYPE_DIR && DIR_CONN_IS_SERVER(conn)) return 1; return 0; } /** Helper function to decide how many bytes out of global_bucket * we're willing to use for this transaction. base is the size * of a cell on the network; priority says whether we should * write many of them or just a few; and conn_bucket (if * non-negative) provides an upper limit for our answer. */ static ssize_t connection_bucket_get_share(int base, int priority, ssize_t global_bucket_val, ssize_t conn_bucket) { ssize_t at_most; ssize_t num_bytes_high = (priority ? 32 : 16) * base; ssize_t num_bytes_low = (priority ? 4 : 2) * base; /* Do a rudimentary limiting so one circuit can't hog a connection. * Pick at most 32 cells, at least 4 cells if possible, and if we're in * the middle pick 1/8 of the available bandwidth. */ at_most = global_bucket_val / 8; at_most -= (at_most % base); /* round down */ if (at_most > num_bytes_high) /* 16 KB, or 8 KB for low-priority */ at_most = num_bytes_high; else if (at_most < num_bytes_low) /* 2 KB, or 1 KB for low-priority */ at_most = num_bytes_low; if (at_most > global_bucket_val) at_most = global_bucket_val; if (conn_bucket >= 0 && at_most > conn_bucket) at_most = conn_bucket; if (at_most < 0) return 0; return at_most; } /** How many bytes at most can we read onto this connection? */ static ssize_t connection_bucket_read_limit(connection_t *conn, time_t now) { int base = RELAY_PAYLOAD_SIZE; int priority = conn->type != CONN_TYPE_DIR; ssize_t conn_bucket = -1; size_t global_bucket_val = token_bucket_rw_get_read(&global_bucket); if (connection_speaks_cells(conn)) { or_connection_t *or_conn = TO_OR_CONN(conn); if (conn->state == OR_CONN_STATE_OPEN) conn_bucket = token_bucket_rw_get_read(&or_conn->bucket); base = get_cell_network_size(or_conn->wide_circ_ids); } if (!connection_is_rate_limited(conn)) { /* be willing to read on local conns even if our buckets are empty */ return conn_bucket>=0 ? conn_bucket : 1<<14; } if (connection_counts_as_relayed_traffic(conn, now)) { size_t relayed = token_bucket_rw_get_read(&global_relayed_bucket); global_bucket_val = MIN(global_bucket_val, relayed); } return connection_bucket_get_share(base, priority, global_bucket_val, conn_bucket); } /** How many bytes at most can we write onto this connection? */ ssize_t connection_bucket_write_limit(connection_t *conn, time_t now) { int base = RELAY_PAYLOAD_SIZE; int priority = conn->type != CONN_TYPE_DIR; size_t conn_bucket = conn->outbuf_flushlen; size_t global_bucket_val = token_bucket_rw_get_write(&global_bucket); if (!connection_is_rate_limited(conn)) { /* be willing to write to local conns even if our buckets are empty */ return conn->outbuf_flushlen; } if (connection_speaks_cells(conn)) { /* use the per-conn write limit if it's lower */ or_connection_t *or_conn = TO_OR_CONN(conn); if (conn->state == OR_CONN_STATE_OPEN) conn_bucket = MIN(conn_bucket, token_bucket_rw_get_write(&or_conn->bucket)); base = get_cell_network_size(or_conn->wide_circ_ids); } if (connection_counts_as_relayed_traffic(conn, now)) { size_t relayed = token_bucket_rw_get_write(&global_relayed_bucket); global_bucket_val = MIN(global_bucket_val, relayed); } return connection_bucket_get_share(base, priority, global_bucket_val, conn_bucket); } /** Return 1 if the global write buckets are low enough that we * shouldn't send attempt bytes of low-priority directory stuff * out to conn. Else return 0. * Priority was 1 for v1 requests (directories and running-routers), * and 2 for v2 requests and later (statuses and descriptors). * * There are a lot of parameters we could use here: * - global_relayed_write_bucket. Low is bad. * - global_write_bucket. Low is bad. * - bandwidthrate. Low is bad. * - bandwidthburst. Not a big factor? * - attempt. High is bad. * - total bytes queued on outbufs. High is bad. But I'm wary of * using this, since a few slow-flushing queues will pump up the * number without meaning what we meant to mean. What we really * mean is "total directory bytes added to outbufs recently", but * that's harder to quantify and harder to keep track of. */ int global_write_bucket_low(connection_t *conn, size_t attempt, int priority) { size_t smaller_bucket = MIN(token_bucket_rw_get_write(&global_bucket), token_bucket_rw_get_write(&global_relayed_bucket)); if (authdir_mode(get_options()) && priority>1) return 0; /* there's always room to answer v2 if we're an auth dir */ if (!connection_is_rate_limited(conn)) return 0; /* local conns don't get limited */ if (smaller_bucket < attempt) return 1; /* not enough space no matter the priority */ { const time_t diff = approx_time() - write_buckets_last_empty_at; if (diff <= 1) return 1; /* we're already hitting our limits, no more please */ } if (priority == 1) { /* old-style v1 query */ /* Could we handle *two* of these requests within the next two seconds? */ const or_options_t *options = get_options(); size_t can_write = (size_t) (smaller_bucket + 2*(options->RelayBandwidthRate ? options->RelayBandwidthRate : options->BandwidthRate)); if (can_write < 2*attempt) return 1; } else { /* v2 query */ /* no further constraints yet */ } return 0; } /** When did we last tell the accounting subsystem about transmitted * bandwidth? */ static time_t last_recorded_accounting_at = 0; /** Helper: adjusts our bandwidth history and informs the controller as * appropriate, given that we have just read num_read bytes and written * num_written bytes on conn. */ static void record_num_bytes_transferred_impl(connection_t *conn, time_t now, size_t num_read, size_t num_written) { /* Count bytes of answering direct and tunneled directory requests */ if (conn->type == CONN_TYPE_DIR && conn->purpose == DIR_PURPOSE_SERVER) { if (num_read > 0) rep_hist_note_dir_bytes_read(num_read, now); if (num_written > 0) rep_hist_note_dir_bytes_written(num_written, now); } if (!connection_is_rate_limited(conn)) return; /* local IPs are free */ if (conn->type == CONN_TYPE_OR) rep_hist_note_or_conn_bytes(conn->global_identifier, num_read, num_written, now); if (num_read > 0) { rep_hist_note_bytes_read(num_read, now); } if (num_written > 0) { rep_hist_note_bytes_written(num_written, now); } if (conn->type == CONN_TYPE_EXIT) rep_hist_note_exit_bytes(conn->port, num_written, num_read); /* Remember these bytes towards statistics. */ stats_increment_bytes_read_and_written(num_read, num_written); /* Remember these bytes towards accounting. */ if (accounting_is_enabled(get_options())) { if (now > last_recorded_accounting_at && last_recorded_accounting_at) { accounting_add_bytes(num_read, num_written, (int)(now - last_recorded_accounting_at)); } else { accounting_add_bytes(num_read, num_written, 0); } last_recorded_accounting_at = now; } } /** We just read num_read and wrote num_written bytes * onto conn. Decrement buckets appropriately. */ static void connection_buckets_decrement(connection_t *conn, time_t now, size_t num_read, size_t num_written) { if (num_written >= INT_MAX || num_read >= INT_MAX) { log_err(LD_BUG, "Value out of range. num_read=%lu, num_written=%lu, " "connection type=%s, state=%s", (unsigned long)num_read, (unsigned long)num_written, conn_type_to_string(conn->type), conn_state_to_string(conn->type, conn->state)); tor_assert_nonfatal_unreached(); if (num_written >= INT_MAX) num_written = 1; if (num_read >= INT_MAX) num_read = 1; } record_num_bytes_transferred_impl(conn, now, num_read, num_written); if (!connection_is_rate_limited(conn)) return; /* local IPs are free */ unsigned flags = 0; if (connection_counts_as_relayed_traffic(conn, now)) { flags = token_bucket_rw_dec(&global_relayed_bucket, num_read, num_written); } flags |= token_bucket_rw_dec(&global_bucket, num_read, num_written); if (flags & TB_WRITE) { write_buckets_last_empty_at = now; } if (connection_speaks_cells(conn) && conn->state == OR_CONN_STATE_OPEN) { or_connection_t *or_conn = TO_OR_CONN(conn); token_bucket_rw_dec(&or_conn->bucket, num_read, num_written); } } /** * Mark conn as needing to stop reading because bandwidth has been * exhausted. If is_global_bw, it is closing because global bandwidth * limit has been exhausted. Otherwise, it is closing because its own * bandwidth limit has been exhausted. */ void connection_read_bw_exhausted(connection_t *conn, bool is_global_bw) { (void)is_global_bw; conn->read_blocked_on_bw = 1; connection_stop_reading(conn); reenable_blocked_connection_schedule(); } /** * Mark conn as needing to stop reading because write bandwidth has * been exhausted. If is_global_bw, it is closing because global * bandwidth limit has been exhausted. Otherwise, it is closing because its * own bandwidth limit has been exhausted. */ void connection_write_bw_exhausted(connection_t *conn, bool is_global_bw) { (void)is_global_bw; conn->write_blocked_on_bw = 1; connection_stop_reading(conn); reenable_blocked_connection_schedule(); } /** If we have exhausted our global buckets, or the buckets for conn, * stop reading. */ void connection_consider_empty_read_buckets(connection_t *conn) { const char *reason; if (!connection_is_rate_limited(conn)) return; /* Always okay. */ int is_global = 1; if (token_bucket_rw_get_read(&global_bucket) <= 0) { reason = "global read bucket exhausted. Pausing."; } else if (connection_counts_as_relayed_traffic(conn, approx_time()) && token_bucket_rw_get_read(&global_relayed_bucket) <= 0) { reason = "global relayed read bucket exhausted. Pausing."; } else if (connection_speaks_cells(conn) && conn->state == OR_CONN_STATE_OPEN && token_bucket_rw_get_read(&TO_OR_CONN(conn)->bucket) <= 0) { reason = "connection read bucket exhausted. Pausing."; is_global = false; } else return; /* all good, no need to stop it */ LOG_FN_CONN(conn, (LOG_DEBUG, LD_NET, "%s", reason)); connection_read_bw_exhausted(conn, is_global); } /** If we have exhausted our global buckets, or the buckets for conn, * stop writing. */ void connection_consider_empty_write_buckets(connection_t *conn) { const char *reason; if (!connection_is_rate_limited(conn)) return; /* Always okay. */ bool is_global = true; if (token_bucket_rw_get_write(&global_bucket) <= 0) { reason = "global write bucket exhausted. Pausing."; } else if (connection_counts_as_relayed_traffic(conn, approx_time()) && token_bucket_rw_get_write(&global_relayed_bucket) <= 0) { reason = "global relayed write bucket exhausted. Pausing."; } else if (connection_speaks_cells(conn) && conn->state == OR_CONN_STATE_OPEN && token_bucket_rw_get_write(&TO_OR_CONN(conn)->bucket) <= 0) { reason = "connection write bucket exhausted. Pausing."; is_global = false; } else return; /* all good, no need to stop it */ LOG_FN_CONN(conn, (LOG_DEBUG, LD_NET, "%s", reason)); connection_write_bw_exhausted(conn, is_global); } /** Initialize the global buckets to the values configured in the * options */ void connection_bucket_init(void) { const or_options_t *options = get_options(); const uint32_t now_ts = monotime_coarse_get_stamp(); token_bucket_rw_init(&global_bucket, (int32_t)options->BandwidthRate, (int32_t)options->BandwidthBurst, now_ts); if (options->RelayBandwidthRate) { token_bucket_rw_init(&global_relayed_bucket, (int32_t)options->RelayBandwidthRate, (int32_t)options->RelayBandwidthBurst, now_ts); } else { token_bucket_rw_init(&global_relayed_bucket, (int32_t)options->BandwidthRate, (int32_t)options->BandwidthBurst, now_ts); } reenable_blocked_connection_init(options); } /** Update the global connection bucket settings to a new value. */ void connection_bucket_adjust(const or_options_t *options) { token_bucket_rw_adjust(&global_bucket, (int32_t)options->BandwidthRate, (int32_t)options->BandwidthBurst); if (options->RelayBandwidthRate) { token_bucket_rw_adjust(&global_relayed_bucket, (int32_t)options->RelayBandwidthRate, (int32_t)options->RelayBandwidthBurst); } else { token_bucket_rw_adjust(&global_relayed_bucket, (int32_t)options->BandwidthRate, (int32_t)options->BandwidthBurst); } } /** * Cached value of the last coarse-timestamp when we refilled the * global buckets. */ static uint32_t last_refilled_global_buckets_ts=0; /** * Refill the token buckets for a single connection conn, and the * global token buckets as appropriate. Requires that now_ts is * the time in coarse timestamp units. */ static void connection_bucket_refill_single(connection_t *conn, uint32_t now_ts) { /* Note that we only check for equality here: the underlying * token bucket functions can handle moving backwards in time if they * need to. */ if (now_ts != last_refilled_global_buckets_ts) { token_bucket_rw_refill(&global_bucket, now_ts); token_bucket_rw_refill(&global_relayed_bucket, now_ts); last_refilled_global_buckets_ts = now_ts; } if (connection_speaks_cells(conn) && conn->state == OR_CONN_STATE_OPEN) { or_connection_t *or_conn = TO_OR_CONN(conn); token_bucket_rw_refill(&or_conn->bucket, now_ts); } } /** * Event to re-enable all connections that were previously blocked on read or * write. */ static mainloop_event_t *reenable_blocked_connections_ev = NULL; /** True iff reenable_blocked_connections_ev is currently scheduled. */ static int reenable_blocked_connections_is_scheduled = 0; /** Delay after which to run reenable_blocked_connections_ev. */ static struct timeval reenable_blocked_connections_delay; /** * Re-enable all connections that were previously blocked on read or write. * This event is scheduled after enough time has elapsed to be sure * that the buckets will refill when the connections have something to do. */ static void reenable_blocked_connections_cb(mainloop_event_t *ev, void *arg) { (void)ev; (void)arg; SMARTLIST_FOREACH_BEGIN(get_connection_array(), connection_t *, conn) { if (conn->read_blocked_on_bw == 1) { connection_start_reading(conn); conn->read_blocked_on_bw = 0; } if (conn->write_blocked_on_bw == 1) { connection_start_writing(conn); conn->write_blocked_on_bw = 0; } } SMARTLIST_FOREACH_END(conn); reenable_blocked_connections_is_scheduled = 0; } /** * Initialize the mainloop event that we use to wake up connections that * find themselves blocked on bandwidth. */ static void reenable_blocked_connection_init(const or_options_t *options) { if (! reenable_blocked_connections_ev) { reenable_blocked_connections_ev = mainloop_event_new(reenable_blocked_connections_cb, NULL); reenable_blocked_connections_is_scheduled = 0; } time_t sec = options->TokenBucketRefillInterval / 1000; int msec = (options->TokenBucketRefillInterval % 1000); reenable_blocked_connections_delay.tv_sec = sec; reenable_blocked_connections_delay.tv_usec = msec * 1000; } /** * Called when we have blocked a connection for being low on bandwidth: * schedule an event to reenable such connections, if it is not already * scheduled. */ static void reenable_blocked_connection_schedule(void) { if (reenable_blocked_connections_is_scheduled) return; if (BUG(reenable_blocked_connections_ev == NULL)) { reenable_blocked_connection_init(get_options()); } mainloop_event_schedule(reenable_blocked_connections_ev, &reenable_blocked_connections_delay); reenable_blocked_connections_is_scheduled = 1; } /** Read bytes from conn-\>s and process them. * * It calls connection_buf_read_from_socket() to bring in any new bytes, * and then calls connection_process_inbuf() to process them. * * Mark the connection and return -1 if you want to close it, else * return 0. */ static int connection_handle_read_impl(connection_t *conn) { ssize_t max_to_read=-1, try_to_read; size_t before, n_read = 0; int socket_error = 0; if (conn->marked_for_close) return 0; /* do nothing */ conn->timestamp_last_read_allowed = approx_time(); connection_bucket_refill_single(conn, monotime_coarse_get_stamp()); switch (conn->type) { case CONN_TYPE_OR_LISTENER: return connection_handle_listener_read(conn, CONN_TYPE_OR); case CONN_TYPE_EXT_OR_LISTENER: return connection_handle_listener_read(conn, CONN_TYPE_EXT_OR); case CONN_TYPE_AP_LISTENER: case CONN_TYPE_AP_TRANS_LISTENER: case CONN_TYPE_AP_NATD_LISTENER: case CONN_TYPE_AP_HTTP_CONNECT_LISTENER: return connection_handle_listener_read(conn, CONN_TYPE_AP); case CONN_TYPE_DIR_LISTENER: return connection_handle_listener_read(conn, CONN_TYPE_DIR); case CONN_TYPE_CONTROL_LISTENER: return connection_handle_listener_read(conn, CONN_TYPE_CONTROL); case CONN_TYPE_AP_DNS_LISTENER: /* This should never happen; eventdns.c handles the reads here. */ tor_fragile_assert(); return 0; } loop_again: try_to_read = max_to_read; tor_assert(!conn->marked_for_close); before = buf_datalen(conn->inbuf); if (connection_buf_read_from_socket(conn, &max_to_read, &socket_error) < 0) { /* There's a read error; kill the connection.*/ if (conn->type == CONN_TYPE_OR) { connection_or_notify_error(TO_OR_CONN(conn), socket_error != 0 ? errno_to_orconn_end_reason(socket_error) : END_OR_CONN_REASON_CONNRESET, socket_error != 0 ? tor_socket_strerror(socket_error) : "(unknown, errno was 0)"); } if (CONN_IS_EDGE(conn)) { edge_connection_t *edge_conn = TO_EDGE_CONN(conn); connection_edge_end_errno(edge_conn); if (conn->type == CONN_TYPE_AP && TO_ENTRY_CONN(conn)->socks_request) { /* broken, don't send a socks reply back */ TO_ENTRY_CONN(conn)->socks_request->has_finished = 1; } } connection_close_immediate(conn); /* Don't flush; connection is dead. */ /* * This can bypass normal channel checking since we did * connection_or_notify_error() above. */ connection_mark_for_close_internal(conn); return -1; } n_read += buf_datalen(conn->inbuf) - before; if (CONN_IS_EDGE(conn) && try_to_read != max_to_read) { /* instruct it not to try to package partial cells. */ if (connection_process_inbuf(conn, 0) < 0) { return -1; } if (!conn->marked_for_close && connection_is_reading(conn) && !conn->inbuf_reached_eof && max_to_read > 0) goto loop_again; /* try reading again, in case more is here now */ } /* one last try, packaging partial cells and all. */ if (!conn->marked_for_close && connection_process_inbuf(conn, 1) < 0) { return -1; } if (conn->linked_conn) { /* The other side's handle_write() will never actually get called, so * we need to invoke the appropriate callbacks ourself. */ connection_t *linked = conn->linked_conn; if (n_read) { /* Probably a no-op, since linked conns typically don't count for * bandwidth rate limiting. But do it anyway so we can keep stats * accurately. Note that since we read the bytes from conn, and * we're writing the bytes onto the linked connection, we count * these as written bytes. */ connection_buckets_decrement(linked, approx_time(), 0, n_read); if (connection_flushed_some(linked) < 0) connection_mark_for_close(linked); if (!connection_wants_to_flush(linked)) connection_finished_flushing(linked); } if (!buf_datalen(linked->outbuf) && conn->active_on_link) connection_stop_reading_from_linked_conn(conn); } /* If we hit the EOF, call connection_reached_eof(). */ if (!conn->marked_for_close && conn->inbuf_reached_eof && connection_reached_eof(conn) < 0) { return -1; } return 0; } /* DOCDOC connection_handle_read */ int connection_handle_read(connection_t *conn) { int res; update_current_time(time(NULL)); res = connection_handle_read_impl(conn); return res; } /** Pull in new bytes from conn-\>s or conn-\>linked_conn onto conn-\>inbuf, * either directly or via TLS. Reduce the token buckets by the number of bytes * read. * * If *max_to_read is -1, then decide it ourselves, else go with the * value passed to us. When returning, if it's changed, subtract the * number of bytes we read from *max_to_read. * * Return -1 if we want to break conn, else return 0. */ static int connection_buf_read_from_socket(connection_t *conn, ssize_t *max_to_read, int *socket_error) { int result; ssize_t at_most = *max_to_read; size_t slack_in_buf, more_to_read; size_t n_read = 0, n_written = 0; if (at_most == -1) { /* we need to initialize it */ /* how many bytes are we allowed to read? */ at_most = connection_bucket_read_limit(conn, approx_time()); } slack_in_buf = buf_slack(conn->inbuf); again: if ((size_t)at_most > slack_in_buf && slack_in_buf >= 1024) { more_to_read = at_most - slack_in_buf; at_most = slack_in_buf; } else { more_to_read = 0; } if (connection_speaks_cells(conn) && conn->state > OR_CONN_STATE_PROXY_HANDSHAKING) { int pending; or_connection_t *or_conn = TO_OR_CONN(conn); size_t initial_size; if (conn->state == OR_CONN_STATE_TLS_HANDSHAKING || conn->state == OR_CONN_STATE_TLS_CLIENT_RENEGOTIATING) { /* continue handshaking even if global token bucket is empty */ return connection_tls_continue_handshake(or_conn); } log_debug(LD_NET, "%d: starting, inbuf_datalen %ld (%d pending in tls object)." " at_most %ld.", (int)conn->s,(long)buf_datalen(conn->inbuf), tor_tls_get_pending_bytes(or_conn->tls), (long)at_most); initial_size = buf_datalen(conn->inbuf); /* else open, or closing */ result = buf_read_from_tls(conn->inbuf, or_conn->tls, at_most); if (TOR_TLS_IS_ERROR(result) || result == TOR_TLS_CLOSE) or_conn->tls_error = result; else or_conn->tls_error = 0; switch (result) { case TOR_TLS_CLOSE: case TOR_TLS_ERROR_IO: log_debug(LD_NET,"TLS connection closed %son read. Closing. " "(Nickname %s, address %s)", result == TOR_TLS_CLOSE ? "cleanly " : "", or_conn->nickname ? or_conn->nickname : "not set", conn->address); return result; CASE_TOR_TLS_ERROR_ANY_NONIO: log_debug(LD_NET,"tls error [%s]. breaking (nickname %s, address %s).", tor_tls_err_to_string(result), or_conn->nickname ? or_conn->nickname : "not set", conn->address); return result; case TOR_TLS_WANTWRITE: connection_start_writing(conn); return 0; case TOR_TLS_WANTREAD: if (conn->in_connection_handle_write) { /* We've been invoked from connection_handle_write, because we're * waiting for a TLS renegotiation, the renegotiation started, and * SSL_read returned WANTWRITE. But now SSL_read is saying WANTREAD * again. Stop waiting for write events now, or else we'll * busy-loop until data arrives for us to read. */ connection_stop_writing(conn); if (!connection_is_reading(conn)) connection_start_reading(conn); } /* we're already reading, one hopes */ break; case TOR_TLS_DONE: /* no data read, so nothing to process */ break; /* so we call bucket_decrement below */ default: break; } pending = tor_tls_get_pending_bytes(or_conn->tls); if (pending) { /* If we have any pending bytes, we read them now. This *can* * take us over our read allotment, but really we shouldn't be * believing that SSL bytes are the same as TCP bytes anyway. */ int r2 = buf_read_from_tls(conn->inbuf, or_conn->tls, pending); if (BUG(r2<0)) { log_warn(LD_BUG, "apparently, reading pending bytes can fail."); return -1; } } result = (int)(buf_datalen(conn->inbuf)-initial_size); tor_tls_get_n_raw_bytes(or_conn->tls, &n_read, &n_written); log_debug(LD_GENERAL, "After TLS read of %d: %ld read, %ld written", result, (long)n_read, (long)n_written); } else if (conn->linked) { if (conn->linked_conn) { result = buf_move_to_buf(conn->inbuf, conn->linked_conn->outbuf, &conn->linked_conn->outbuf_flushlen); } else { result = 0; } //log_notice(LD_GENERAL, "Moved %d bytes on an internal link!", result); /* If the other side has disappeared, or if it's been marked for close and * we flushed its outbuf, then we should set our inbuf_reached_eof. */ if (!conn->linked_conn || (conn->linked_conn->marked_for_close && buf_datalen(conn->linked_conn->outbuf) == 0)) conn->inbuf_reached_eof = 1; n_read = (size_t) result; } else { /* !connection_speaks_cells, !conn->linked_conn. */ int reached_eof = 0; CONN_LOG_PROTECT(conn, result = buf_read_from_socket(conn->inbuf, conn->s, at_most, &reached_eof, socket_error)); if (reached_eof) conn->inbuf_reached_eof = 1; // log_fn(LOG_DEBUG,"read_to_buf returned %d.",read_result); if (result < 0) return -1; n_read = (size_t) result; } if (n_read > 0) { /* change *max_to_read */ *max_to_read = at_most - n_read; /* Update edge_conn->n_read */ if (conn->type == CONN_TYPE_AP) { edge_connection_t *edge_conn = TO_EDGE_CONN(conn); /* Check for overflow: */ if (PREDICT_LIKELY(UINT32_MAX - edge_conn->n_read > n_read)) edge_conn->n_read += (int)n_read; else edge_conn->n_read = UINT32_MAX; } /* If CONN_BW events are enabled, update conn->n_read_conn_bw for * OR/DIR/EXIT connections, checking for overflow. */ if (get_options()->TestingEnableConnBwEvent && (conn->type == CONN_TYPE_OR || conn->type == CONN_TYPE_DIR || conn->type == CONN_TYPE_EXIT)) { if (PREDICT_LIKELY(UINT32_MAX - conn->n_read_conn_bw > n_read)) conn->n_read_conn_bw += (int)n_read; else conn->n_read_conn_bw = UINT32_MAX; } } connection_buckets_decrement(conn, approx_time(), n_read, n_written); if (more_to_read && result == at_most) { slack_in_buf = buf_slack(conn->inbuf); at_most = more_to_read; goto again; } /* Call even if result is 0, since the global read bucket may * have reached 0 on a different conn, and this connection needs to * know to stop reading. */ connection_consider_empty_read_buckets(conn); if (n_written > 0 && connection_is_writing(conn)) connection_consider_empty_write_buckets(conn); return 0; } /** A pass-through to fetch_from_buf. */ int connection_buf_get_bytes(char *string, size_t len, connection_t *conn) { return buf_get_bytes(conn->inbuf, string, len); } /** As buf_get_line(), but read from a connection's input buffer. */ int connection_buf_get_line(connection_t *conn, char *data, size_t *data_len) { return buf_get_line(conn->inbuf, data, data_len); } /** As fetch_from_buf_http, but fetches from a connection's input buffer_t as * appropriate. */ int connection_fetch_from_buf_http(connection_t *conn, char **headers_out, size_t max_headerlen, char **body_out, size_t *body_used, size_t max_bodylen, int force_complete) { return fetch_from_buf_http(conn->inbuf, headers_out, max_headerlen, body_out, body_used, max_bodylen, force_complete); } /** Return conn-\>outbuf_flushlen: how many bytes conn wants to flush * from its outbuf. */ int connection_wants_to_flush(connection_t *conn) { return conn->outbuf_flushlen > 0; } /** Are there too many bytes on edge connection conn's outbuf to * send back a relay-level sendme yet? Return 1 if so, 0 if not. Used by * connection_edge_consider_sending_sendme(). */ int connection_outbuf_too_full(connection_t *conn) { return (conn->outbuf_flushlen > 10*CELL_PAYLOAD_SIZE); } /** * On Windows Vista and Windows 7, tune the send buffer size according to a * hint from the OS. * * This should help fix slow upload rates. */ static void update_send_buffer_size(tor_socket_t sock) { #ifdef _WIN32 /* We only do this on Vista and 7, because earlier versions of Windows * don't have the SIO_IDEAL_SEND_BACKLOG_QUERY functionality, and on * later versions it isn't necessary. */ static int isVistaOr7 = -1; if (isVistaOr7 == -1) { isVistaOr7 = 0; OSVERSIONINFO osvi = { 0 }; osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO); GetVersionEx(&osvi); if (osvi.dwMajorVersion == 6 && osvi.dwMinorVersion < 2) isVistaOr7 = 1; } if (!isVistaOr7) return; if (get_options()->ConstrainedSockets) return; ULONG isb = 0; DWORD bytesReturned = 0; if (!WSAIoctl(sock, SIO_IDEAL_SEND_BACKLOG_QUERY, NULL, 0, &isb, sizeof(isb), &bytesReturned, NULL, NULL)) { setsockopt(sock, SOL_SOCKET, SO_SNDBUF, (const char*)&isb, sizeof(isb)); } #else (void) sock; #endif } /** Try to flush more bytes onto conn-\>s. * * This function gets called either from conn_write_callback() in main.c * when libevent tells us that conn wants to write, or below * from connection_buf_add() when an entire TLS record is ready. * * Update conn-\>timestamp_last_write_allowed to now, and call flush_buf * or flush_buf_tls appropriately. If it succeeds and there are no more * more bytes on conn-\>outbuf, then call connection_finished_flushing * on it too. * * If force, then write as many bytes as possible, ignoring bandwidth * limits. (Used for flushing messages to controller connections on fatal * errors.) * * Mark the connection and return -1 if you want to close it, else * return 0. */ static int connection_handle_write_impl(connection_t *conn, int force) { int e; socklen_t len=(socklen_t)sizeof(e); int result; ssize_t max_to_write; time_t now = approx_time(); size_t n_read = 0, n_written = 0; int dont_stop_writing = 0; tor_assert(!connection_is_listener(conn)); if (conn->marked_for_close || !SOCKET_OK(conn->s)) return 0; /* do nothing */ if (conn->in_flushed_some) { log_warn(LD_BUG, "called recursively from inside conn->in_flushed_some"); return 0; } conn->timestamp_last_write_allowed = now; connection_bucket_refill_single(conn, monotime_coarse_get_stamp()); /* Sometimes, "writable" means "connected". */ if (connection_state_is_connecting(conn)) { if (getsockopt(conn->s, SOL_SOCKET, SO_ERROR, (void*)&e, &len) < 0) { log_warn(LD_BUG, "getsockopt() syscall failed"); if (conn->type == CONN_TYPE_OR) { or_connection_t *orconn = TO_OR_CONN(conn); connection_or_close_for_error(orconn, 0); } else { if (CONN_IS_EDGE(conn)) { connection_edge_end_errno(TO_EDGE_CONN(conn)); } connection_mark_for_close(conn); } return -1; } if (e) { /* some sort of error, but maybe just inprogress still */ if (!ERRNO_IS_CONN_EINPROGRESS(e)) { log_info(LD_NET,"in-progress connect failed. Removing. (%s)", tor_socket_strerror(e)); if (CONN_IS_EDGE(conn)) connection_edge_end_errno(TO_EDGE_CONN(conn)); if (conn->type == CONN_TYPE_OR) connection_or_notify_error(TO_OR_CONN(conn), errno_to_orconn_end_reason(e), tor_socket_strerror(e)); connection_close_immediate(conn); /* * This can bypass normal channel checking since we did * connection_or_notify_error() above. */ connection_mark_for_close_internal(conn); return -1; } else { return 0; /* no change, see if next time is better */ } } /* The connection is successful. */ if (connection_finished_connecting(conn)<0) return -1; } max_to_write = force ? (ssize_t)conn->outbuf_flushlen : connection_bucket_write_limit(conn, now); if (connection_speaks_cells(conn) && conn->state > OR_CONN_STATE_PROXY_HANDSHAKING) { or_connection_t *or_conn = TO_OR_CONN(conn); size_t initial_size; if (conn->state == OR_CONN_STATE_TLS_HANDSHAKING || conn->state == OR_CONN_STATE_TLS_CLIENT_RENEGOTIATING) { connection_stop_writing(conn); if (connection_tls_continue_handshake(or_conn) < 0) { /* Don't flush; connection is dead. */ connection_or_notify_error(or_conn, END_OR_CONN_REASON_MISC, "TLS error in connection_tls_" "continue_handshake()"); connection_close_immediate(conn); /* * This can bypass normal channel checking since we did * connection_or_notify_error() above. */ connection_mark_for_close_internal(conn); return -1; } return 0; } else if (conn->state == OR_CONN_STATE_TLS_SERVER_RENEGOTIATING) { return connection_handle_read(conn); } /* else open, or closing */ initial_size = buf_datalen(conn->outbuf); result = buf_flush_to_tls(conn->outbuf, or_conn->tls, max_to_write, &conn->outbuf_flushlen); if (result >= 0) update_send_buffer_size(conn->s); /* If we just flushed the last bytes, tell the channel on the * or_conn to check if it needs to geoip_change_dirreq_state() */ /* XXXX move this to flushed_some or finished_flushing -NM */ if (buf_datalen(conn->outbuf) == 0 && or_conn->chan) channel_notify_flushed(TLS_CHAN_TO_BASE(or_conn->chan)); switch (result) { CASE_TOR_TLS_ERROR_ANY: case TOR_TLS_CLOSE: log_info(LD_NET, result != TOR_TLS_CLOSE ? "tls error. breaking.":"TLS connection closed on flush"); /* Don't flush; connection is dead. */ connection_or_notify_error(or_conn, END_OR_CONN_REASON_MISC, result != TOR_TLS_CLOSE ? "TLS error in during flush" : "TLS closed during flush"); connection_close_immediate(conn); /* * This can bypass normal channel checking since we did * connection_or_notify_error() above. */ connection_mark_for_close_internal(conn); return -1; case TOR_TLS_WANTWRITE: log_debug(LD_NET,"wanted write."); /* we're already writing */ dont_stop_writing = 1; break; case TOR_TLS_WANTREAD: /* Make sure to avoid a loop if the receive buckets are empty. */ log_debug(LD_NET,"wanted read."); if (!connection_is_reading(conn)) { connection_write_bw_exhausted(conn, true); /* we'll start reading again when we get more tokens in our * read bucket; then we'll start writing again too. */ } /* else no problem, we're already reading */ return 0; /* case TOR_TLS_DONE: * for TOR_TLS_DONE, fall through to check if the flushlen * is empty, so we can stop writing. */ } tor_tls_get_n_raw_bytes(or_conn->tls, &n_read, &n_written); log_debug(LD_GENERAL, "After TLS write of %d: %ld read, %ld written", result, (long)n_read, (long)n_written); or_conn->bytes_xmitted += result; or_conn->bytes_xmitted_by_tls += n_written; /* So we notice bytes were written even on error */ /* XXXX This cast is safe since we can never write INT_MAX bytes in a * single set of TLS operations. But it looks kinda ugly. If we refactor * the *_buf_tls functions, we should make them return ssize_t or size_t * or something. */ result = (int)(initial_size-buf_datalen(conn->outbuf)); } else { CONN_LOG_PROTECT(conn, result = buf_flush_to_socket(conn->outbuf, conn->s, max_to_write, &conn->outbuf_flushlen)); if (result < 0) { if (CONN_IS_EDGE(conn)) connection_edge_end_errno(TO_EDGE_CONN(conn)); if (conn->type == CONN_TYPE_AP) { /* writing failed; we couldn't send a SOCKS reply if we wanted to */ TO_ENTRY_CONN(conn)->socks_request->has_finished = 1; } connection_close_immediate(conn); /* Don't flush; connection is dead. */ connection_mark_for_close(conn); return -1; } update_send_buffer_size(conn->s); n_written = (size_t) result; } if (n_written && conn->type == CONN_TYPE_AP) { edge_connection_t *edge_conn = TO_EDGE_CONN(conn); /* Check for overflow: */ if (PREDICT_LIKELY(UINT32_MAX - edge_conn->n_written > n_written)) edge_conn->n_written += (int)n_written; else edge_conn->n_written = UINT32_MAX; } /* If CONN_BW events are enabled, update conn->n_written_conn_bw for * OR/DIR/EXIT connections, checking for overflow. */ if (n_written && get_options()->TestingEnableConnBwEvent && (conn->type == CONN_TYPE_OR || conn->type == CONN_TYPE_DIR || conn->type == CONN_TYPE_EXIT)) { if (PREDICT_LIKELY(UINT32_MAX - conn->n_written_conn_bw > n_written)) conn->n_written_conn_bw += (int)n_written; else conn->n_written_conn_bw = UINT32_MAX; } connection_buckets_decrement(conn, approx_time(), n_read, n_written); if (result > 0) { /* If we wrote any bytes from our buffer, then call the appropriate * functions. */ if (connection_flushed_some(conn) < 0) { if (connection_speaks_cells(conn)) { connection_or_notify_error(TO_OR_CONN(conn), END_OR_CONN_REASON_MISC, "Got error back from " "connection_flushed_some()"); } /* * This can bypass normal channel checking since we did * connection_or_notify_error() above. */ connection_mark_for_close_internal(conn); } } if (!connection_wants_to_flush(conn) && !dont_stop_writing) { /* it's done flushing */ if (connection_finished_flushing(conn) < 0) { /* already marked */ return -1; } return 0; } /* Call even if result is 0, since the global write bucket may * have reached 0 on a different conn, and this connection needs to * know to stop writing. */ connection_consider_empty_write_buckets(conn); if (n_read > 0 && connection_is_reading(conn)) connection_consider_empty_read_buckets(conn); return 0; } /* DOCDOC connection_handle_write */ int connection_handle_write(connection_t *conn, int force) { int res; update_current_time(time(NULL)); conn->in_connection_handle_write = 1; res = connection_handle_write_impl(conn, force); conn->in_connection_handle_write = 0; return res; } /** * Try to flush data that's waiting for a write on conn. Return * -1 on failure, 0 on success. * * Don't use this function for regular writing; the buffers * system should be good enough at scheduling writes there. Instead, this * function is for cases when we're about to exit or something and we want * to report it right away. */ int connection_flush(connection_t *conn) { return connection_handle_write(conn, 1); } /** Helper for connection_write_to_buf_impl and connection_write_buf_to_buf: * * Return true iff it is okay to queue bytes on conn's outbuf for * writing. */ static int connection_may_write_to_buf(connection_t *conn) { /* if it's marked for close, only allow write if we mean to flush it */ if (conn->marked_for_close && !conn->hold_open_until_flushed) return 0; return 1; } /** Helper for connection_write_to_buf_impl and connection_write_buf_to_buf: * * Called when an attempt to add bytes on conn's outbuf has failed; * mark the connection and warn as appropriate. */ static void connection_write_to_buf_failed(connection_t *conn) { if (CONN_IS_EDGE(conn)) { /* if it failed, it means we have our package/delivery windows set wrong compared to our max outbuf size. close the whole circuit. */ log_warn(LD_NET, "write_to_buf failed. Closing circuit (fd %d).", (int)conn->s); circuit_mark_for_close(circuit_get_by_edge_conn(TO_EDGE_CONN(conn)), END_CIRC_REASON_INTERNAL); } else if (conn->type == CONN_TYPE_OR) { or_connection_t *orconn = TO_OR_CONN(conn); log_warn(LD_NET, "write_to_buf failed on an orconn; notifying of error " "(fd %d)", (int)(conn->s)); connection_or_close_for_error(orconn, 0); } else { log_warn(LD_NET, "write_to_buf failed. Closing connection (fd %d).", (int)conn->s); connection_mark_for_close(conn); } } /** Helper for connection_write_to_buf_impl and connection_write_buf_to_buf: * * Called when an attempt to add bytes on conn's outbuf has succeeded: * record the number of bytes added. */ static void connection_write_to_buf_commit(connection_t *conn, size_t len) { /* If we receive optimistic data in the EXIT_CONN_STATE_RESOLVING * state, we don't want to try to write it right away, since * conn->write_event won't be set yet. Otherwise, write data from * this conn as the socket is available. */ if (conn->write_event) { connection_start_writing(conn); } conn->outbuf_flushlen += len; } /** Append len bytes of string onto conn's * outbuf, and ask it to start writing. * * If zlib is nonzero, this is a directory connection that should get * its contents compressed or decompressed as they're written. If zlib is * negative, this is the last data to be compressed, and the connection's zlib * state should be flushed. */ MOCK_IMPL(void, connection_write_to_buf_impl_,(const char *string, size_t len, connection_t *conn, int zlib)) { /* XXXX This function really needs to return -1 on failure. */ int r; if (!len && !(zlib<0)) return; if (!connection_may_write_to_buf(conn)) return; size_t written; if (zlib) { size_t old_datalen = buf_datalen(conn->outbuf); dir_connection_t *dir_conn = TO_DIR_CONN(conn); int done = zlib < 0; CONN_LOG_PROTECT(conn, r = buf_add_compress(conn->outbuf, dir_conn->compress_state, string, len, done)); written = buf_datalen(conn->outbuf) - old_datalen; } else { CONN_LOG_PROTECT(conn, r = buf_add(conn->outbuf, string, len)); written = len; } if (r < 0) { connection_write_to_buf_failed(conn); return; } connection_write_to_buf_commit(conn, written); } void connection_buf_add_compress(const char *string, size_t len, dir_connection_t *conn, int done) { connection_write_to_buf_impl_(string, len, TO_CONN(conn), done ? -1 : 1); } /** * Add all bytes from buf to conn's outbuf, draining them * from buf. (If the connection is marked and will soon be closed, * nothing is drained.) */ void connection_buf_add_buf(connection_t *conn, buf_t *buf) { tor_assert(conn); tor_assert(buf); size_t len = buf_datalen(buf); if (len == 0) return; if (!connection_may_write_to_buf(conn)) return; buf_move_all(conn->outbuf, buf); connection_write_to_buf_commit(conn, len); } #define CONN_GET_ALL_TEMPLATE(var, test) \ STMT_BEGIN \ smartlist_t *conns = get_connection_array(); \ smartlist_t *ret_conns = smartlist_new(); \ SMARTLIST_FOREACH_BEGIN(conns, connection_t *, var) { \ if (var && (test) && !var->marked_for_close) \ smartlist_add(ret_conns, var); \ } SMARTLIST_FOREACH_END(var); \ return ret_conns; \ STMT_END /* Return a list of connections that aren't close and matches the given type * and state. The returned list can be empty and must be freed using * smartlist_free(). The caller does NOT have ownership of the objects in the * list so it must not free them nor reference them as they can disappear. */ smartlist_t * connection_list_by_type_state(int type, int state) { CONN_GET_ALL_TEMPLATE(conn, (conn->type == type && conn->state == state)); } /* Return a list of connections that aren't close and matches the given type * and purpose. The returned list can be empty and must be freed using * smartlist_free(). The caller does NOT have ownership of the objects in the * list so it must not free them nor reference them as they can disappear. */ smartlist_t * connection_list_by_type_purpose(int type, int purpose) { CONN_GET_ALL_TEMPLATE(conn, (conn->type == type && conn->purpose == purpose)); } /** Return a connection_t * from get_connection_array() that satisfies test on * var, and that is not marked for close. */ #define CONN_GET_TEMPLATE(var, test) \ STMT_BEGIN \ smartlist_t *conns = get_connection_array(); \ SMARTLIST_FOREACH(conns, connection_t *, var, \ { \ if (var && (test) && !var->marked_for_close) \ return var; \ }); \ return NULL; \ STMT_END /** Return a connection with given type, address, port, and purpose; * or NULL if no such connection exists (or if all such connections are marked * for close). */ MOCK_IMPL(connection_t *, connection_get_by_type_addr_port_purpose,(int type, const tor_addr_t *addr, uint16_t port, int purpose)) { CONN_GET_TEMPLATE(conn, (conn->type == type && tor_addr_eq(&conn->addr, addr) && conn->port == port && conn->purpose == purpose)); } /** Return the stream with id id if it is not already marked for * close. */ connection_t * connection_get_by_global_id(uint64_t id) { CONN_GET_TEMPLATE(conn, conn->global_identifier == id); } /** Return a connection of type type that is not marked for close. */ connection_t * connection_get_by_type(int type) { CONN_GET_TEMPLATE(conn, conn->type == type); } /** Return a connection of type type that is in state state, * and that is not marked for close. */ connection_t * connection_get_by_type_state(int type, int state) { CONN_GET_TEMPLATE(conn, conn->type == type && conn->state == state); } /** Return a connection of type type that has rendquery equal * to rendquery, and that is not marked for close. If state * is non-zero, conn must be of that state too. */ connection_t * connection_get_by_type_state_rendquery(int type, int state, const char *rendquery) { tor_assert(type == CONN_TYPE_DIR || type == CONN_TYPE_AP || type == CONN_TYPE_EXIT); tor_assert(rendquery); CONN_GET_TEMPLATE(conn, (conn->type == type && (!state || state == conn->state)) && ( (type == CONN_TYPE_DIR && TO_DIR_CONN(conn)->rend_data && !rend_cmp_service_ids(rendquery, rend_data_get_address(TO_DIR_CONN(conn)->rend_data))) || (CONN_IS_EDGE(conn) && TO_EDGE_CONN(conn)->rend_data && !rend_cmp_service_ids(rendquery, rend_data_get_address(TO_EDGE_CONN(conn)->rend_data))) )); } /** Return a new smartlist of dir_connection_t * from get_connection_array() * that satisfy conn_test on connection_t *conn_var, and dirconn_test on * dir_connection_t *dirconn_var. conn_var must be of CONN_TYPE_DIR and not * marked for close to be included in the list. */ #define DIR_CONN_LIST_TEMPLATE(conn_var, conn_test, \ dirconn_var, dirconn_test) \ STMT_BEGIN \ smartlist_t *conns = get_connection_array(); \ smartlist_t *dir_conns = smartlist_new(); \ SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn_var) { \ if (conn_var && (conn_test) \ && conn_var->type == CONN_TYPE_DIR \ && !conn_var->marked_for_close) { \ dir_connection_t *dirconn_var = TO_DIR_CONN(conn_var); \ if (dirconn_var && (dirconn_test)) { \ smartlist_add(dir_conns, dirconn_var); \ } \ } \ } SMARTLIST_FOREACH_END(conn_var); \ return dir_conns; \ STMT_END /** Return a list of directory connections that are fetching the item * described by purpose/resource. If there are none, * return an empty list. This list must be freed using smartlist_free, * but the pointers in it must not be freed. * Note that this list should not be cached, as the pointers in it can be * freed if their connections close. */ smartlist_t * connection_dir_list_by_purpose_and_resource( int purpose, const char *resource) { DIR_CONN_LIST_TEMPLATE(conn, conn->purpose == purpose, dirconn, 0 == strcmp_opt(resource, dirconn->requested_resource)); } /** Return a list of directory connections that are fetching the item * described by purpose/resource/state. If there are * none, return an empty list. This list must be freed using smartlist_free, * but the pointers in it must not be freed. * Note that this list should not be cached, as the pointers in it can be * freed if their connections close. */ smartlist_t * connection_dir_list_by_purpose_resource_and_state( int purpose, const char *resource, int state) { DIR_CONN_LIST_TEMPLATE(conn, conn->purpose == purpose && conn->state == state, dirconn, 0 == strcmp_opt(resource, dirconn->requested_resource)); } #undef DIR_CONN_LIST_TEMPLATE /** Return an arbitrary active OR connection that isn't this_conn. * * We use this to guess if we should tell the controller that we * didn't manage to connect to any of our bridges. */ static connection_t * connection_get_another_active_or_conn(const or_connection_t *this_conn) { CONN_GET_TEMPLATE(conn, conn != TO_CONN(this_conn) && conn->type == CONN_TYPE_OR); } /** Return 1 if there are any active OR connections apart from * this_conn. * * We use this to guess if we should tell the controller that we * didn't manage to connect to any of our bridges. */ int any_other_active_or_conns(const or_connection_t *this_conn) { connection_t *conn = connection_get_another_active_or_conn(this_conn); if (conn != NULL) { log_debug(LD_DIR, "%s: Found an OR connection: %s", __func__, conn->address); return 1; } return 0; } #undef CONN_GET_TEMPLATE /** Return 1 if conn is a listener conn, else return 0. */ int connection_is_listener(connection_t *conn) { if (conn->type == CONN_TYPE_OR_LISTENER || conn->type == CONN_TYPE_EXT_OR_LISTENER || conn->type == CONN_TYPE_AP_LISTENER || conn->type == CONN_TYPE_AP_TRANS_LISTENER || conn->type == CONN_TYPE_AP_DNS_LISTENER || conn->type == CONN_TYPE_AP_NATD_LISTENER || conn->type == CONN_TYPE_AP_HTTP_CONNECT_LISTENER || conn->type == CONN_TYPE_DIR_LISTENER || conn->type == CONN_TYPE_CONTROL_LISTENER) return 1; return 0; } /** Return 1 if conn is in state "open" and is not marked * for close, else return 0. */ int connection_state_is_open(connection_t *conn) { tor_assert(conn); if (conn->marked_for_close) return 0; if ((conn->type == CONN_TYPE_OR && conn->state == OR_CONN_STATE_OPEN) || (conn->type == CONN_TYPE_EXT_OR) || (conn->type == CONN_TYPE_AP && conn->state == AP_CONN_STATE_OPEN) || (conn->type == CONN_TYPE_EXIT && conn->state == EXIT_CONN_STATE_OPEN) || (conn->type == CONN_TYPE_CONTROL && conn->state == CONTROL_CONN_STATE_OPEN)) return 1; return 0; } /** Return 1 if conn is in 'connecting' state, else return 0. */ int connection_state_is_connecting(connection_t *conn) { tor_assert(conn); if (conn->marked_for_close) return 0; switch (conn->type) { case CONN_TYPE_OR: return conn->state == OR_CONN_STATE_CONNECTING; case CONN_TYPE_EXIT: return conn->state == EXIT_CONN_STATE_CONNECTING; case CONN_TYPE_DIR: return conn->state == DIR_CONN_STATE_CONNECTING; } return 0; } /** Allocates a base64'ed authenticator for use in http or https * auth, based on the input string authenticator. Returns it * if success, else returns NULL. */ char * alloc_http_authenticator(const char *authenticator) { /* an authenticator in Basic authentication * is just the string "username:password" */ const size_t authenticator_length = strlen(authenticator); const size_t base64_authenticator_length = base64_encode_size(authenticator_length, 0) + 1; char *base64_authenticator = tor_malloc(base64_authenticator_length); if (base64_encode(base64_authenticator, base64_authenticator_length, authenticator, authenticator_length, 0) < 0) { tor_free(base64_authenticator); /* free and set to null */ } return base64_authenticator; } /** Given a socket handle, check whether the local address (sockname) of the * socket is one that we've connected from before. If so, double-check * whether our address has changed and we need to generate keys. If we do, * call init_keys(). */ static void client_check_address_changed(tor_socket_t sock) { tor_addr_t out_addr, iface_addr; tor_addr_t **last_interface_ip_ptr; sa_family_t family; if (!outgoing_addrs) outgoing_addrs = smartlist_new(); if (tor_addr_from_getsockname(&out_addr, sock) < 0) { int e = tor_socket_errno(sock); log_warn(LD_NET, "getsockname() to check for address change failed: %s", tor_socket_strerror(e)); return; } family = tor_addr_family(&out_addr); if (family == AF_INET) last_interface_ip_ptr = &last_interface_ipv4; else if (family == AF_INET6) last_interface_ip_ptr = &last_interface_ipv6; else return; if (! *last_interface_ip_ptr) { tor_addr_t *a = tor_malloc_zero(sizeof(tor_addr_t)); if (get_interface_address6(LOG_INFO, family, a)==0) { *last_interface_ip_ptr = a; } else { tor_free(a); } } /* If we've used this address previously, we're okay. */ SMARTLIST_FOREACH(outgoing_addrs, const tor_addr_t *, a_ptr, if (tor_addr_eq(a_ptr, &out_addr)) return; ); /* Uh-oh. We haven't connected from this address before. Has the interface * address changed? */ if (get_interface_address6(LOG_INFO, family, &iface_addr)<0) return; if (tor_addr_eq(&iface_addr, *last_interface_ip_ptr)) { /* Nope, it hasn't changed. Add this address to the list. */ smartlist_add(outgoing_addrs, tor_memdup(&out_addr, sizeof(tor_addr_t))); } else { /* The interface changed. We're a client, so we need to regenerate our * keys. First, reset the state. */ log_notice(LD_NET, "Our IP address has changed. Rotating keys..."); tor_addr_copy(*last_interface_ip_ptr, &iface_addr); SMARTLIST_FOREACH(outgoing_addrs, tor_addr_t*, a_ptr, tor_free(a_ptr)); smartlist_clear(outgoing_addrs); smartlist_add(outgoing_addrs, tor_memdup(&out_addr, sizeof(tor_addr_t))); /* We'll need to resolve ourselves again. */ reset_last_resolved_addr(); /* Okay, now change our keys. */ ip_address_changed(1); } } /** Some systems have limited system buffers for recv and xmit on * sockets allocated in a virtual server or similar environment. For a Tor * server this can produce the "Error creating network socket: No buffer * space available" error once all available TCP buffer space is consumed. * This method will attempt to constrain the buffers allocated for the socket * to the desired size to stay below system TCP buffer limits. */ static void set_constrained_socket_buffers(tor_socket_t sock, int size) { void *sz = (void*)&size; socklen_t sz_sz = (socklen_t) sizeof(size); if (setsockopt(sock, SOL_SOCKET, SO_SNDBUF, sz, sz_sz) < 0) { int e = tor_socket_errno(sock); log_warn(LD_NET, "setsockopt() to constrain send " "buffer to %d bytes failed: %s", size, tor_socket_strerror(e)); } if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF, sz, sz_sz) < 0) { int e = tor_socket_errno(sock); log_warn(LD_NET, "setsockopt() to constrain recv " "buffer to %d bytes failed: %s", size, tor_socket_strerror(e)); } } /** Process new bytes that have arrived on conn-\>inbuf. * * This function just passes conn to the connection-specific * connection_*_process_inbuf() function. It also passes in * package_partial if wanted. */ static int connection_process_inbuf(connection_t *conn, int package_partial) { tor_assert(conn); switch (conn->type) { case CONN_TYPE_OR: return connection_or_process_inbuf(TO_OR_CONN(conn)); case CONN_TYPE_EXT_OR: return connection_ext_or_process_inbuf(TO_OR_CONN(conn)); case CONN_TYPE_EXIT: case CONN_TYPE_AP: return connection_edge_process_inbuf(TO_EDGE_CONN(conn), package_partial); case CONN_TYPE_DIR: return connection_dir_process_inbuf(TO_DIR_CONN(conn)); case CONN_TYPE_CONTROL: return connection_control_process_inbuf(TO_CONTROL_CONN(conn)); default: log_err(LD_BUG,"got unexpected conn type %d.", conn->type); tor_fragile_assert(); return -1; } } /** Called whenever we've written data on a connection. */ static int connection_flushed_some(connection_t *conn) { int r = 0; tor_assert(!conn->in_flushed_some); conn->in_flushed_some = 1; if (conn->type == CONN_TYPE_DIR && conn->state == DIR_CONN_STATE_SERVER_WRITING) { r = connection_dirserv_flushed_some(TO_DIR_CONN(conn)); } else if (conn->type == CONN_TYPE_OR) { r = connection_or_flushed_some(TO_OR_CONN(conn)); } else if (CONN_IS_EDGE(conn)) { r = connection_edge_flushed_some(TO_EDGE_CONN(conn)); } conn->in_flushed_some = 0; return r; } /** We just finished flushing bytes to the appropriately low network layer, * and there are no more bytes remaining in conn-\>outbuf or * conn-\>tls to be flushed. * * This function just passes conn to the connection-specific * connection_*_finished_flushing() function. */ static int connection_finished_flushing(connection_t *conn) { tor_assert(conn); /* If the connection is closed, don't try to do anything more here. */ if (CONN_IS_CLOSED(conn)) return 0; // log_fn(LOG_DEBUG,"entered. Socket %u.", conn->s); connection_stop_writing(conn); switch (conn->type) { case CONN_TYPE_OR: return connection_or_finished_flushing(TO_OR_CONN(conn)); case CONN_TYPE_EXT_OR: return connection_ext_or_finished_flushing(TO_OR_CONN(conn)); case CONN_TYPE_AP: case CONN_TYPE_EXIT: return connection_edge_finished_flushing(TO_EDGE_CONN(conn)); case CONN_TYPE_DIR: return connection_dir_finished_flushing(TO_DIR_CONN(conn)); case CONN_TYPE_CONTROL: return connection_control_finished_flushing(TO_CONTROL_CONN(conn)); default: log_err(LD_BUG,"got unexpected conn type %d.", conn->type); tor_fragile_assert(); return -1; } } /** Called when our attempt to connect() to another server has just * succeeded. * * This function just passes conn to the connection-specific * connection_*_finished_connecting() function. */ static int connection_finished_connecting(connection_t *conn) { tor_assert(conn); if (!server_mode(get_options())) { /* See whether getsockname() says our address changed. We need to do this * now that the connection has finished, because getsockname() on Windows * won't work until then. */ client_check_address_changed(conn->s); } switch (conn->type) { case CONN_TYPE_OR: return connection_or_finished_connecting(TO_OR_CONN(conn)); case CONN_TYPE_EXIT: return connection_edge_finished_connecting(TO_EDGE_CONN(conn)); case CONN_TYPE_DIR: return connection_dir_finished_connecting(TO_DIR_CONN(conn)); default: log_err(LD_BUG,"got unexpected conn type %d.", conn->type); tor_fragile_assert(); return -1; } } /** Callback: invoked when a connection reaches an EOF event. */ static int connection_reached_eof(connection_t *conn) { switch (conn->type) { case CONN_TYPE_OR: case CONN_TYPE_EXT_OR: return connection_or_reached_eof(TO_OR_CONN(conn)); case CONN_TYPE_AP: case CONN_TYPE_EXIT: return connection_edge_reached_eof(TO_EDGE_CONN(conn)); case CONN_TYPE_DIR: return connection_dir_reached_eof(TO_DIR_CONN(conn)); case CONN_TYPE_CONTROL: return connection_control_reached_eof(TO_CONTROL_CONN(conn)); default: log_err(LD_BUG,"got unexpected conn type %d.", conn->type); tor_fragile_assert(); return -1; } } /** Comparator for the two-orconn case in OOS victim sort */ static int oos_victim_comparator_for_orconns(or_connection_t *a, or_connection_t *b) { int a_circs, b_circs; /* Fewer circuits == higher priority for OOS kill, sort earlier */ a_circs = connection_or_get_num_circuits(a); b_circs = connection_or_get_num_circuits(b); if (a_circs < b_circs) return 1; else if (a_circs > b_circs) return -1; else return 0; } /** Sort comparator for OOS victims; better targets sort before worse * ones. */ static int oos_victim_comparator(const void **a_v, const void **b_v) { connection_t *a = NULL, *b = NULL; /* Get connection pointers out */ a = (connection_t *)(*a_v); b = (connection_t *)(*b_v); tor_assert(a != NULL); tor_assert(b != NULL); /* * We always prefer orconns as victims currently; we won't even see * these non-orconn cases, but if we do, sort them after orconns. */ if (a->type == CONN_TYPE_OR && b->type == CONN_TYPE_OR) { return oos_victim_comparator_for_orconns(TO_OR_CONN(a), TO_OR_CONN(b)); } else { /* * One isn't an orconn; if one is, it goes first. We currently have no * opinions about cases where neither is an orconn. */ if (a->type == CONN_TYPE_OR) return -1; else if (b->type == CONN_TYPE_OR) return 1; else return 0; } } /** Pick n victim connections for the OOS handler and return them in a * smartlist. */ MOCK_IMPL(STATIC smartlist_t *, pick_oos_victims, (int n)) { smartlist_t *eligible = NULL, *victims = NULL; smartlist_t *conns; int conn_counts_by_type[CONN_TYPE_MAX_ + 1], i; /* * Big damn assumption (someone improve this someday!): * * Socket exhaustion normally happens on high-volume relays, and so * most of the connections involved are orconns. We should pick victims * by assembling a list of all orconns, and sorting them in order of * how much 'damage' by some metric we'd be doing by dropping them. * * If we move on from orconns, we should probably think about incoming * directory connections next, or exit connections. Things we should * probably never kill are controller connections and listeners. * * This function will count how many connections of different types * exist and log it for purposes of gathering data on typical OOS * situations to guide future improvements. */ /* First, get the connection array */ conns = get_connection_array(); /* * Iterate it and pick out eligible connection types, and log some stats * along the way. */ eligible = smartlist_new(); memset(conn_counts_by_type, 0, sizeof(conn_counts_by_type)); SMARTLIST_FOREACH_BEGIN(conns, connection_t *, c) { /* Bump the counter */ tor_assert(c->type <= CONN_TYPE_MAX_); ++(conn_counts_by_type[c->type]); /* Skip anything without a socket we can free */ if (!(SOCKET_OK(c->s))) { continue; } /* Skip anything we would count as moribund */ if (connection_is_moribund(c)) { continue; } switch (c->type) { case CONN_TYPE_OR: /* We've got an orconn, it's eligible to be OOSed */ smartlist_add(eligible, c); break; default: /* We don't know what to do with it, ignore it */ break; } } SMARTLIST_FOREACH_END(c); /* Log some stats */ if (smartlist_len(conns) > 0) { /* At least one counter must be non-zero */ log_info(LD_NET, "Some stats on conn types seen during OOS follow"); for (i = CONN_TYPE_MIN_; i <= CONN_TYPE_MAX_; ++i) { /* Did we see any? */ if (conn_counts_by_type[i] > 0) { log_info(LD_NET, "%s: %d conns", conn_type_to_string(i), conn_counts_by_type[i]); } } log_info(LD_NET, "Done with OOS conn type stats"); } /* Did we find more eligible targets than we want to kill? */ if (smartlist_len(eligible) > n) { /* Sort the list in order of target preference */ smartlist_sort(eligible, oos_victim_comparator); /* Pick first n as victims */ victims = smartlist_new(); for (i = 0; i < n; ++i) { smartlist_add(victims, smartlist_get(eligible, i)); } /* Free the original list */ smartlist_free(eligible); } else { /* No, we can just call them all victims */ victims = eligible; } return victims; } /** Kill a list of connections for the OOS handler. */ MOCK_IMPL(STATIC void, kill_conn_list_for_oos, (smartlist_t *conns)) { if (!conns) return; SMARTLIST_FOREACH_BEGIN(conns, connection_t *, c) { /* Make sure the channel layer gets told about orconns */ if (c->type == CONN_TYPE_OR) { connection_or_close_for_error(TO_OR_CONN(c), 1); } else { connection_mark_for_close(c); } } SMARTLIST_FOREACH_END(c); log_notice(LD_NET, "OOS handler marked %d connections", smartlist_len(conns)); } /** Check if a connection is on the way out so the OOS handler doesn't try * to kill more than it needs. */ int connection_is_moribund(connection_t *conn) { if (conn != NULL && (conn->conn_array_index < 0 || conn->marked_for_close)) { return 1; } else { return 0; } } /** Out-of-Sockets handler; n_socks is the current number of open * sockets, and failed is non-zero if a socket exhaustion related * error immediately preceded this call. This is where to do * circuit-killing heuristics as needed. */ void connection_check_oos(int n_socks, int failed) { int target_n_socks = 0, moribund_socks, socks_to_kill; smartlist_t *conns; /* Early exit: is OOS checking disabled? */ if (get_options()->DisableOOSCheck) { return; } /* Sanity-check args */ tor_assert(n_socks >= 0); /* * Make some log noise; keep it at debug level since this gets a chance * to run on every connection attempt. */ log_debug(LD_NET, "Running the OOS handler (%d open sockets, %s)", n_socks, (failed != 0) ? "exhaustion seen" : "no exhaustion"); /* * Check if we're really handling an OOS condition, and if so decide how * many sockets we want to get down to. Be sure we check if the threshold * is distinct from zero first; it's possible for this to be called a few * times before we've finished reading the config. */ if (n_socks >= get_options()->ConnLimit_high_thresh && get_options()->ConnLimit_high_thresh != 0 && get_options()->ConnLimit_ != 0) { /* Try to get down to the low threshold */ target_n_socks = get_options()->ConnLimit_low_thresh; log_notice(LD_NET, "Current number of sockets %d is greater than configured " "limit %d; OOS handler trying to get down to %d", n_socks, get_options()->ConnLimit_high_thresh, target_n_socks); } else if (failed) { /* * If we're not at the limit but we hit a socket exhaustion error, try to * drop some (but not as aggressively as ConnLimit_low_threshold, which is * 3/4 of ConnLimit_) */ target_n_socks = (n_socks * 9) / 10; log_notice(LD_NET, "We saw socket exhaustion at %d open sockets; OOS handler " "trying to get down to %d", n_socks, target_n_socks); } if (target_n_socks > 0) { /* * It's an OOS! * * Count moribund sockets; it's be important that anything we decide * to get rid of here but don't immediately close get counted as moribund * on subsequent invocations so we don't try to kill too many things if * connection_check_oos() gets called multiple times. */ moribund_socks = connection_count_moribund(); if (moribund_socks < n_socks - target_n_socks) { socks_to_kill = n_socks - target_n_socks - moribund_socks; conns = pick_oos_victims(socks_to_kill); if (conns) { kill_conn_list_for_oos(conns); log_notice(LD_NET, "OOS handler killed %d conns", smartlist_len(conns)); smartlist_free(conns); } else { log_notice(LD_NET, "OOS handler failed to pick any victim conns"); } } else { log_notice(LD_NET, "Not killing any sockets for OOS because there are %d " "already moribund, and we only want to eliminate %d", moribund_socks, n_socks - target_n_socks); } } } /** Log how many bytes are used by buffers of different kinds and sizes. */ void connection_dump_buffer_mem_stats(int severity) { uint64_t used_by_type[CONN_TYPE_MAX_+1]; uint64_t alloc_by_type[CONN_TYPE_MAX_+1]; int n_conns_by_type[CONN_TYPE_MAX_+1]; uint64_t total_alloc = 0; uint64_t total_used = 0; int i; smartlist_t *conns = get_connection_array(); memset(used_by_type, 0, sizeof(used_by_type)); memset(alloc_by_type, 0, sizeof(alloc_by_type)); memset(n_conns_by_type, 0, sizeof(n_conns_by_type)); SMARTLIST_FOREACH_BEGIN(conns, connection_t *, c) { int tp = c->type; ++n_conns_by_type[tp]; if (c->inbuf) { used_by_type[tp] += buf_datalen(c->inbuf); alloc_by_type[tp] += buf_allocation(c->inbuf); } if (c->outbuf) { used_by_type[tp] += buf_datalen(c->outbuf); alloc_by_type[tp] += buf_allocation(c->outbuf); } } SMARTLIST_FOREACH_END(c); for (i=0; i <= CONN_TYPE_MAX_; ++i) { total_used += used_by_type[i]; total_alloc += alloc_by_type[i]; } tor_log(severity, LD_GENERAL, "In buffers for %d connections: %"PRIu64" used/%"PRIu64" allocated", smartlist_len(conns), (total_used), (total_alloc)); for (i=CONN_TYPE_MIN_; i <= CONN_TYPE_MAX_; ++i) { if (!n_conns_by_type[i]) continue; tor_log(severity, LD_GENERAL, " For %d %s connections: %"PRIu64" used/%"PRIu64" allocated", n_conns_by_type[i], conn_type_to_string(i), (used_by_type[i]), (alloc_by_type[i])); } } /** Verify that connection conn has all of its invariants * correct. Trigger an assert if anything is invalid. */ void assert_connection_ok(connection_t *conn, time_t now) { (void) now; /* XXXX unused. */ tor_assert(conn); tor_assert(conn->type >= CONN_TYPE_MIN_); tor_assert(conn->type <= CONN_TYPE_MAX_); switch (conn->type) { case CONN_TYPE_OR: case CONN_TYPE_EXT_OR: tor_assert(conn->magic == OR_CONNECTION_MAGIC); break; case CONN_TYPE_AP: tor_assert(conn->magic == ENTRY_CONNECTION_MAGIC); break; case CONN_TYPE_EXIT: tor_assert(conn->magic == EDGE_CONNECTION_MAGIC); break; case CONN_TYPE_DIR: tor_assert(conn->magic == DIR_CONNECTION_MAGIC); break; case CONN_TYPE_CONTROL: tor_assert(conn->magic == CONTROL_CONNECTION_MAGIC); break; CASE_ANY_LISTENER_TYPE: tor_assert(conn->magic == LISTENER_CONNECTION_MAGIC); break; default: tor_assert(conn->magic == BASE_CONNECTION_MAGIC); break; } if (conn->linked_conn) { tor_assert(conn->linked_conn->linked_conn == conn); tor_assert(conn->linked); } if (conn->linked) tor_assert(!SOCKET_OK(conn->s)); if (conn->outbuf_flushlen > 0) { /* With optimistic data, we may have queued data in * EXIT_CONN_STATE_RESOLVING while the conn is not yet marked to writing. * */ tor_assert((conn->type == CONN_TYPE_EXIT && conn->state == EXIT_CONN_STATE_RESOLVING) || connection_is_writing(conn) || conn->write_blocked_on_bw || (CONN_IS_EDGE(conn) && TO_EDGE_CONN(conn)->edge_blocked_on_circ)); } if (conn->hold_open_until_flushed) tor_assert(conn->marked_for_close); /* XXXX check: read_blocked_on_bw, write_blocked_on_bw, s, conn_array_index, * marked_for_close. */ /* buffers */ if (conn->inbuf) buf_assert_ok(conn->inbuf); if (conn->outbuf) buf_assert_ok(conn->outbuf); if (conn->type == CONN_TYPE_OR) { or_connection_t *or_conn = TO_OR_CONN(conn); if (conn->state == OR_CONN_STATE_OPEN) { /* tor_assert(conn->bandwidth > 0); */ /* the above isn't necessarily true: if we just did a TLS * handshake but we didn't recognize the other peer, or it * gave a bad cert/etc, then we won't have assigned bandwidth, * yet it will be open. -RD */ // tor_assert(conn->read_bucket >= 0); } // tor_assert(conn->addr && conn->port); tor_assert(conn->address); if (conn->state > OR_CONN_STATE_PROXY_HANDSHAKING) tor_assert(or_conn->tls); } if (CONN_IS_EDGE(conn)) { /* XXX unchecked: package window, deliver window. */ if (conn->type == CONN_TYPE_AP) { entry_connection_t *entry_conn = TO_ENTRY_CONN(conn); if (entry_conn->chosen_exit_optional || entry_conn->chosen_exit_retries) tor_assert(entry_conn->chosen_exit_name); tor_assert(entry_conn->socks_request); if (conn->state == AP_CONN_STATE_OPEN) { tor_assert(entry_conn->socks_request->has_finished); if (!conn->marked_for_close) { tor_assert(ENTRY_TO_EDGE_CONN(entry_conn)->cpath_layer); assert_cpath_layer_ok(ENTRY_TO_EDGE_CONN(entry_conn)->cpath_layer); } } } if (conn->type == CONN_TYPE_EXIT) { tor_assert(conn->purpose == EXIT_PURPOSE_CONNECT || conn->purpose == EXIT_PURPOSE_RESOLVE); } } else if (conn->type == CONN_TYPE_DIR) { } else { /* Purpose is only used for dir and exit types currently */ tor_assert(!conn->purpose); } switch (conn->type) { CASE_ANY_LISTENER_TYPE: tor_assert(conn->state == LISTENER_STATE_READY); break; case CONN_TYPE_OR: tor_assert(conn->state >= OR_CONN_STATE_MIN_); tor_assert(conn->state <= OR_CONN_STATE_MAX_); break; case CONN_TYPE_EXT_OR: tor_assert(conn->state >= EXT_OR_CONN_STATE_MIN_); tor_assert(conn->state <= EXT_OR_CONN_STATE_MAX_); break; case CONN_TYPE_EXIT: tor_assert(conn->state >= EXIT_CONN_STATE_MIN_); tor_assert(conn->state <= EXIT_CONN_STATE_MAX_); tor_assert(conn->purpose >= EXIT_PURPOSE_MIN_); tor_assert(conn->purpose <= EXIT_PURPOSE_MAX_); break; case CONN_TYPE_AP: tor_assert(conn->state >= AP_CONN_STATE_MIN_); tor_assert(conn->state <= AP_CONN_STATE_MAX_); tor_assert(TO_ENTRY_CONN(conn)->socks_request); break; case CONN_TYPE_DIR: tor_assert(conn->state >= DIR_CONN_STATE_MIN_); tor_assert(conn->state <= DIR_CONN_STATE_MAX_); tor_assert(conn->purpose >= DIR_PURPOSE_MIN_); tor_assert(conn->purpose <= DIR_PURPOSE_MAX_); break; case CONN_TYPE_CONTROL: tor_assert(conn->state >= CONTROL_CONN_STATE_MIN_); tor_assert(conn->state <= CONTROL_CONN_STATE_MAX_); break; default: tor_assert(0); } } /** Fills addr and port with the details of the global * proxy server we are using. * conn contains the connection we are using the proxy for. * * Return 0 on success, -1 on failure. */ int get_proxy_addrport(tor_addr_t *addr, uint16_t *port, int *proxy_type, const connection_t *conn) { const or_options_t *options = get_options(); /* Client Transport Plugins can use another proxy, but that should be hidden * from the rest of tor (as the plugin is responsible for dealing with the * proxy), check it first, then check the rest of the proxy types to allow * the config to have unused ClientTransportPlugin entries. */ if (options->ClientTransportPlugin) { const transport_t *transport = NULL; int r; r = get_transport_by_bridge_addrport(&conn->addr, conn->port, &transport); if (r<0) return -1; if (transport) { /* transport found */ tor_addr_copy(addr, &transport->addr); *port = transport->port; *proxy_type = transport->socks_version; return 0; } /* Unused ClientTransportPlugin. */ } if (options->HTTPSProxy) { tor_addr_copy(addr, &options->HTTPSProxyAddr); *port = options->HTTPSProxyPort; *proxy_type = PROXY_CONNECT; return 0; } else if (options->Socks4Proxy) { tor_addr_copy(addr, &options->Socks4ProxyAddr); *port = options->Socks4ProxyPort; *proxy_type = PROXY_SOCKS4; return 0; } else if (options->Socks5Proxy) { tor_addr_copy(addr, &options->Socks5ProxyAddr); *port = options->Socks5ProxyPort; *proxy_type = PROXY_SOCKS5; return 0; } tor_addr_make_unspec(addr); *port = 0; *proxy_type = PROXY_NONE; return 0; } /** Log a failed connection to a proxy server. * conn is the connection we use the proxy server for. */ void log_failed_proxy_connection(connection_t *conn) { tor_addr_t proxy_addr; uint16_t proxy_port; int proxy_type; if (get_proxy_addrport(&proxy_addr, &proxy_port, &proxy_type, conn) != 0) return; /* if we have no proxy set up, leave this function. */ log_warn(LD_NET, "The connection to the %s proxy server at %s just failed. " "Make sure that the proxy server is up and running.", proxy_type_to_string(proxy_type), fmt_addrport(&proxy_addr, proxy_port)); } /** Return string representation of proxy_type. */ static const char * proxy_type_to_string(int proxy_type) { switch (proxy_type) { case PROXY_CONNECT: return "HTTP"; case PROXY_SOCKS4: return "SOCKS4"; case PROXY_SOCKS5: return "SOCKS5"; case PROXY_PLUGGABLE: return "pluggable transports SOCKS"; case PROXY_NONE: return "NULL"; default: tor_assert(0); } return NULL; /*Unreached*/ } /** Call connection_free_minimal() on every connection in our array, and * release all storage held by connection.c. * * Don't do the checks in connection_free(), because they will * fail. */ void connection_free_all(void) { smartlist_t *conns = get_connection_array(); /* We don't want to log any messages to controllers. */ SMARTLIST_FOREACH(conns, connection_t *, conn, if (conn->type == CONN_TYPE_CONTROL) TO_CONTROL_CONN(conn)->event_mask = 0); control_update_global_event_mask(); /* Unlink everything from the identity map. */ connection_or_clear_identity_map(); connection_or_clear_ext_or_id_map(); /* Clear out our list of broken connections */ clear_broken_connection_map(0); SMARTLIST_FOREACH(conns, connection_t *, conn, connection_free_minimal(conn)); if (outgoing_addrs) { SMARTLIST_FOREACH(outgoing_addrs, tor_addr_t *, addr, tor_free(addr)); smartlist_free(outgoing_addrs); outgoing_addrs = NULL; } tor_free(last_interface_ipv4); tor_free(last_interface_ipv6); last_recorded_accounting_at = 0; mainloop_event_free(reenable_blocked_connections_ev); reenable_blocked_connections_is_scheduled = 0; memset(&reenable_blocked_connections_delay, 0, sizeof(struct timeval)); } /** Log a warning, and possibly emit a control event, that received came * at a skewed time. trusted indicates that the source was one * that we had more faith in and therefore the warning level should have higher * severity. */ MOCK_IMPL(void, clock_skew_warning, (const connection_t *conn, long apparent_skew, int trusted, log_domain_mask_t domain, const char *received, const char *source)) { char dbuf[64]; char *ext_source = NULL, *warn = NULL; format_time_interval(dbuf, sizeof(dbuf), apparent_skew); if (conn) tor_asprintf(&ext_source, "%s:%s:%d", source, conn->address, conn->port); else ext_source = tor_strdup(source); log_fn(trusted ? LOG_WARN : LOG_INFO, domain, "Received %s with skewed time (%s): " "It seems that our clock is %s by %s, or that theirs is %s%s. " "Tor requires an accurate clock to work: please check your time, " "timezone, and date settings.", received, ext_source, apparent_skew > 0 ? "ahead" : "behind", dbuf, apparent_skew > 0 ? "behind" : "ahead", (!conn || trusted) ? "" : ", or they are sending us the wrong time"); if (trusted) { control_event_general_status(LOG_WARN, "CLOCK_SKEW SKEW=%ld SOURCE=%s", apparent_skew, ext_source); tor_asprintf(&warn, "Clock skew %ld in %s from %s", apparent_skew, received, source); control_event_bootstrap_problem(warn, "CLOCK_SKEW", conn, 1); } tor_free(warn); tor_free(ext_source); }