/* This file is part of GNUnet Copyright (C) 2002--2015 GNUnet e.V. GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ /** * @file transport/plugin_transport_tcp.c * @brief Implementation of the TCP transport service * @author Christian Grothoff */ #include "platform.h" #include "gnunet_hello_lib.h" #include "gnunet_constants.h" #include "gnunet_util_lib.h" #include "gnunet_nat_lib.h" #include "gnunet_protocols.h" #include "gnunet_resolver_service.h" #include "gnunet_signatures.h" #include "gnunet_statistics_service.h" #include "gnunet_transport_service.h" #include "gnunet_transport_plugin.h" #include "transport.h" #define LOG(kind,...) GNUNET_log_from (kind, "transport-tcp",__VA_ARGS__) #define PLUGIN_NAME "tcp" /** * How long until we give up on establishing an NAT connection? * Must be > 4 RTT */ #define NAT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 10) GNUNET_NETWORK_STRUCT_BEGIN /** * Initial handshake message for a session. */ struct WelcomeMessage { /** * Type is #GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME. */ struct GNUNET_MessageHeader header; /** * Identity of the node connecting (TCP client) */ struct GNUNET_PeerIdentity clientIdentity; }; /** * Basically a WELCOME message, but with the purpose * of giving the waiting peer a client handle to use */ struct TCP_NAT_ProbeMessage { /** * Type is #GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_NAT_PROBE. */ struct GNUNET_MessageHeader header; /** * Identity of the sender of the message. */ struct GNUNET_PeerIdentity clientIdentity; }; GNUNET_NETWORK_STRUCT_END /** * Context for sending a NAT probe via TCP. */ struct TCPProbeContext { /** * Active probes are kept in a DLL. */ struct TCPProbeContext *next; /** * Active probes are kept in a DLL. */ struct TCPProbeContext *prev; /** * Probe connection. */ struct GNUNET_CONNECTION_Handle *sock; /** * Message to be sent. */ struct TCP_NAT_ProbeMessage message; /** * Handle to the transmission. */ struct GNUNET_CONNECTION_TransmitHandle *transmit_handle; /** * Transport plugin handle. */ struct Plugin *plugin; }; /** * Bits in the `options` field of TCP addresses. */ enum TcpAddressOptions { /** * No bits set. */ TCP_OPTIONS_NONE = 0, /** * See #HTTP_OPTIONS_VERIFY_CERTIFICATE. */ TCP_OPTIONS_RESERVED = 1, /** * Enable TCP Stealth-style port knocking. */ TCP_OPTIONS_TCP_STEALTH = 2 }; GNUNET_NETWORK_STRUCT_BEGIN /** * Network format for IPv4 addresses. */ struct IPv4TcpAddress { /** * Optional options and flags for this address, * see `enum TcpAddressOptions` */ uint32_t options GNUNET_PACKED; /** * IPv4 address, in network byte order. */ uint32_t ipv4_addr GNUNET_PACKED; /** * Port number, in network byte order. */ uint16_t t4_port GNUNET_PACKED; }; /** * Network format for IPv6 addresses. */ struct IPv6TcpAddress { /** * Optional flags for this address * see `enum TcpAddressOptions` */ uint32_t options GNUNET_PACKED; /** * IPv6 address. */ struct in6_addr ipv6_addr GNUNET_PACKED; /** * Port number, in network byte order. */ uint16_t t6_port GNUNET_PACKED; }; GNUNET_NETWORK_STRUCT_END /** * Encapsulation of all of the state of the plugin. */ struct Plugin; /** * Information kept for each message that is yet to * be transmitted. */ struct PendingMessage { /** * This is a doubly-linked list. */ struct PendingMessage *next; /** * This is a doubly-linked list. */ struct PendingMessage *prev; /** * The pending message */ const char *msg; /** * Continuation function to call once the message * has been sent. Can be NULL if there is no * continuation to call. */ GNUNET_TRANSPORT_TransmitContinuation transmit_cont; /** * Closure for @e transmit_cont. */ void *transmit_cont_cls; /** * Timeout value for the pending message. */ struct GNUNET_TIME_Absolute timeout; /** * So that the gnunet-service-transport can group messages together, * these pending messages need to accept a message buffer and size * instead of just a `struct GNUNET_MessageHeader`. */ size_t message_size; }; /** * Session handle for TCP connections. */ struct GNUNET_ATS_Session { /** * To whom are we talking to (set to our identity * if we are still waiting for the welcome message) */ struct GNUNET_PeerIdentity target; /** * Pointer to the global plugin struct. */ struct Plugin *plugin; /** * The client (used to identify this connection) */ struct GNUNET_SERVER_Client *client; /** * Task cleaning up a NAT client connection establishment attempt; */ struct GNUNET_SCHEDULER_Task *nat_connection_timeout; /** * Messages currently pending for transmission * to this peer, if any. */ struct PendingMessage *pending_messages_head; /** * Messages currently pending for transmission * to this peer, if any. */ struct PendingMessage *pending_messages_tail; /** * Handle for pending transmission request. */ struct GNUNET_SERVER_TransmitHandle *transmit_handle; /** * Address of the other peer. */ struct GNUNET_HELLO_Address *address; /** * ID of task used to delay receiving more to throttle sender. */ struct GNUNET_SCHEDULER_Task *receive_delay_task; /** * Session timeout task */ struct GNUNET_SCHEDULER_Task *timeout_task; /** * When will this session time out? */ struct GNUNET_TIME_Absolute timeout; /** * When will we continue to read from the socket? * (used to enforce inbound quota). */ struct GNUNET_TIME_Absolute receive_delay; /** * Last activity on this connection. Used to select preferred * connection. */ struct GNUNET_TIME_Absolute last_activity; /** * Number of bytes waiting for transmission to this peer. */ unsigned long long bytes_in_queue; /** * Number of messages waiting for transmission to this peer. */ unsigned int msgs_in_queue; /** * Network type of the address. */ enum GNUNET_ATS_Network_Type scope; /** * Are we still expecting the welcome message? (#GNUNET_YES/#GNUNET_NO) */ int expecting_welcome; /** * Was this session created using NAT traversal? */ int is_nat; }; /** * Context for address to string conversion, closure * for #append_port(). */ struct PrettyPrinterContext { /** * DLL */ struct PrettyPrinterContext *next; /** * DLL */ struct PrettyPrinterContext *prev; /** * Our plugin. */ struct Plugin *plugin; /** * Timeout task */ struct GNUNET_SCHEDULER_Task *timeout_task; /** * Resolver handle */ struct GNUNET_RESOLVER_RequestHandle *resolver_handle; /** * Function to call with the result. */ GNUNET_TRANSPORT_AddressStringCallback asc; /** * Clsoure for @e asc. */ void *asc_cls; /** * IPv6 address */ int ipv6; /** * Options */ uint32_t options; /** * Port to add after the IP address. */ uint16_t port; }; /** * Encapsulation of all of the state of the plugin. */ struct Plugin { /** * Our environment. */ struct GNUNET_TRANSPORT_PluginEnvironment *env; /** * The listen socket. */ struct GNUNET_CONNECTION_Handle *lsock; /** * Our handle to the NAT module. */ struct GNUNET_NAT_Handle *nat; /** * Map from peer identities to sessions for the given peer. */ struct GNUNET_CONTAINER_MultiPeerMap *sessionmap; /** * Handle to the network service. */ struct GNUNET_SERVICE_Context *service; /** * Handle to the server for this service. */ struct GNUNET_SERVER_Handle *server; /** * Copy of the handler array where the closures are * set to this struct's instance. */ struct GNUNET_SERVER_MessageHandler *handlers; /** * Map of peers we have tried to contact behind a NAT */ struct GNUNET_CONTAINER_MultiPeerMap *nat_wait_conns; /** * List of active TCP probes. */ struct TCPProbeContext *probe_head; /** * List of active TCP probes. */ struct TCPProbeContext *probe_tail; /** * Function to call about session status changes. */ GNUNET_TRANSPORT_SessionInfoCallback sic; /** * Closure for @e sic. */ void *sic_cls; /** * ID of task used to update our addresses when one expires. */ struct GNUNET_SCHEDULER_Task *address_update_task; /** * Running pretty printers: head */ struct PrettyPrinterContext *ppc_dll_head; /** * Running pretty printers: tail */ struct PrettyPrinterContext *ppc_dll_tail; /** * Welcome message used by this peer. */ struct WelcomeMessage my_welcome; /** * How many more TCP sessions are we allowed to open right now? */ unsigned long long max_connections; /** * How many more TCP sessions do we have right now? */ unsigned long long cur_connections; /** * Address options */ uint32_t myoptions; /** * Port that we are actually listening on. */ uint16_t open_port; /** * Port that the user said we would have visible to the * rest of the world. */ uint16_t adv_port; }; /** * If a session monitor is attached, notify it about the new * session state. * * @param plugin our plugin * @param session session that changed state * @param state new state of the session */ static void notify_session_monitor (struct Plugin *plugin, struct GNUNET_ATS_Session *session, enum GNUNET_TRANSPORT_SessionState state) { struct GNUNET_TRANSPORT_SessionInfo info; if (NULL == plugin->sic) return; memset (&info, 0, sizeof (info)); info.state = state; info.is_inbound = (0 != (GNUNET_HELLO_ADDRESS_INFO_INBOUND & session->address->local_info)) ? GNUNET_YES : GNUNET_NO; info.num_msg_pending = session->msgs_in_queue; info.num_bytes_pending = session->bytes_in_queue; if (NULL != session->receive_delay_task) info.receive_delay = session->receive_delay; info.session_timeout = session->timeout; info.address = session->address; plugin->sic (plugin->sic_cls, session, &info); } /** * Our external IP address/port mapping has changed. * * @param cls closure, the `struct Plugin` * @param add_remove #GNUNET_YES to mean the new public IP address, #GNUNET_NO to mean * the previous (now invalid) one * @param addr either the previous or the new public IP address * @param addrlen actual length of @a addr */ static void tcp_nat_port_map_callback (void *cls, int add_remove, const struct sockaddr *addr, socklen_t addrlen) { struct Plugin *plugin = cls; struct GNUNET_HELLO_Address *address; struct IPv4TcpAddress t4; struct IPv6TcpAddress t6; void *arg; size_t args; LOG(GNUNET_ERROR_TYPE_INFO, "NAT notification to %s address `%s'\n", (GNUNET_YES == add_remove) ? "add" : "remove", GNUNET_a2s (addr, addrlen)); /* convert 'addr' to our internal format */ switch (addr->sa_family) { case AF_INET: GNUNET_assert(addrlen == sizeof(struct sockaddr_in)); memset (&t4, 0, sizeof(t4)); t4.options = htonl (plugin->myoptions); t4.ipv4_addr = ((struct sockaddr_in *) addr)->sin_addr.s_addr; t4.t4_port = ((struct sockaddr_in *) addr)->sin_port; arg = &t4; args = sizeof (t4); break; case AF_INET6: GNUNET_assert(addrlen == sizeof(struct sockaddr_in6)); memset (&t6, 0, sizeof(t6)); GNUNET_memcpy (&t6.ipv6_addr, &((struct sockaddr_in6 *) addr)->sin6_addr, sizeof(struct in6_addr)); t6.options = htonl (plugin->myoptions); t6.t6_port = ((struct sockaddr_in6 *) addr)->sin6_port; arg = &t6; args = sizeof (t6); break; default: GNUNET_break(0); return; } /* modify our published address list */ GNUNET_assert ((args == sizeof (struct IPv4TcpAddress)) || (args == sizeof (struct IPv6TcpAddress))); address = GNUNET_HELLO_address_allocate (plugin->env->my_identity, PLUGIN_NAME, arg, args, GNUNET_HELLO_ADDRESS_INFO_NONE); plugin->env->notify_address (plugin->env->cls, add_remove, address); GNUNET_HELLO_address_free(address); } /** * Function called for a quick conversion of the binary address to * a numeric address. Note that the caller must not free the * address and that the next call to this function is allowed * to override the address again. * * @param cls closure (`struct Plugin*`) * @param addr binary address * @param addrlen length of @a addr * @return string representing the same address */ static const char * tcp_plugin_address_to_string (void *cls, const void *addr, size_t addrlen) { static char rbuf[INET6_ADDRSTRLEN + 12]; char buf[INET6_ADDRSTRLEN]; const void *sb; struct in_addr a4; struct in6_addr a6; const struct IPv4TcpAddress *t4; const struct IPv6TcpAddress *t6; int af; uint16_t port; uint32_t options; switch (addrlen) { case sizeof(struct IPv6TcpAddress): t6 = addr; af = AF_INET6; port = ntohs (t6->t6_port); options = ntohl (t6->options); GNUNET_memcpy (&a6, &t6->ipv6_addr, sizeof(a6)); sb = &a6; break; case sizeof(struct IPv4TcpAddress): t4 = addr; af = AF_INET; port = ntohs (t4->t4_port); options = ntohl (t4->options); GNUNET_memcpy (&a4, &t4->ipv4_addr, sizeof(a4)); sb = &a4; break; default: LOG (GNUNET_ERROR_TYPE_WARNING, _("Unexpected address length: %u bytes\n"), (unsigned int) addrlen); return NULL ; } if (NULL == inet_ntop (af, sb, buf, INET6_ADDRSTRLEN)) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "inet_ntop"); return NULL ; } GNUNET_snprintf (rbuf, sizeof(rbuf), (af == AF_INET6) ? "%s.%u.[%s]:%u" : "%s.%u.%s:%u", PLUGIN_NAME, options, buf, port); return rbuf; } /** * Function called to convert a string address to * a binary address. * * @param cls closure (`struct Plugin*`) * @param addr string address * @param addrlen length of the address * @param buf location to store the buffer * @param added location to store the number of bytes in the buffer. * If the function returns #GNUNET_SYSERR, its contents are undefined. * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure */ static int tcp_plugin_string_to_address (void *cls, const char *addr, uint16_t addrlen, void **buf, size_t *added) { struct sockaddr_storage socket_address; char *address; char *plugin; char *optionstr; uint32_t options; /* Format tcp.options.address:port */ address = NULL; plugin = NULL; optionstr = NULL; if ((NULL == addr) || (0 == addrlen)) { GNUNET_break(0); return GNUNET_SYSERR; } if ('\0' != addr[addrlen - 1]) { GNUNET_break(0); return GNUNET_SYSERR; } if (strlen (addr) != addrlen - 1) { GNUNET_break(0); return GNUNET_SYSERR; } plugin = GNUNET_strdup (addr); optionstr = strchr (plugin, '.'); if (NULL == optionstr) { GNUNET_break(0); GNUNET_free(plugin); return GNUNET_SYSERR; } optionstr[0] = '\0'; optionstr++; options = atol (optionstr); address = strchr (optionstr, '.'); if (NULL == address) { GNUNET_break(0); GNUNET_free(plugin); return GNUNET_SYSERR; } address[0] = '\0'; address++; if (GNUNET_OK != GNUNET_STRINGS_to_address_ip (address, strlen (address), &socket_address)) { GNUNET_break(0); GNUNET_free(plugin); return GNUNET_SYSERR; } GNUNET_free(plugin); switch (socket_address.ss_family) { case AF_INET: { struct IPv4TcpAddress *t4; struct sockaddr_in *in4 = (struct sockaddr_in *) &socket_address; t4 = GNUNET_new (struct IPv4TcpAddress); t4->options = htonl (options); t4->ipv4_addr = in4->sin_addr.s_addr; t4->t4_port = in4->sin_port; *buf = t4; *added = sizeof(struct IPv4TcpAddress); return GNUNET_OK; } case AF_INET6: { struct IPv6TcpAddress *t6; struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &socket_address; t6 = GNUNET_new (struct IPv6TcpAddress); t6->options = htonl (options); t6->ipv6_addr = in6->sin6_addr; t6->t6_port = in6->sin6_port; *buf = t6; *added = sizeof(struct IPv6TcpAddress); return GNUNET_OK; } default: return GNUNET_SYSERR; } } /** * Find the session handle for the given client. * Currently uses both the hashmap and the client * context, as the client context is new and the * logic still needs to be tested. * * @param plugin the plugin * @param client which client to find the session handle for * @return NULL if no matching session exists */ static struct GNUNET_ATS_Session * lookup_session_by_client (struct Plugin *plugin, struct GNUNET_SERVER_Client *client) { return GNUNET_SERVER_client_get_user_context (client, struct GNUNET_ATS_Session); } /** * Functions with this signature are called whenever we need * to close a session due to a disconnect or failure to * establish a connection. * * @param cls the `struct Plugin` * @param session session to close down * @return #GNUNET_OK on success */ static int tcp_plugin_disconnect_session (void *cls, struct GNUNET_ATS_Session *session) { struct Plugin *plugin = cls; struct PendingMessage *pm; LOG (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting session of peer `%s' address `%s'\n", GNUNET_i2s (&session->target), tcp_plugin_address_to_string (session->plugin, session->address->address, session->address->address_length)); if (NULL != session->timeout_task) { GNUNET_SCHEDULER_cancel (session->timeout_task); session->timeout_task = NULL; session->timeout = GNUNET_TIME_UNIT_ZERO_ABS; } if (GNUNET_YES == GNUNET_CONTAINER_multipeermap_remove (plugin->sessionmap, &session->target, session)) { GNUNET_STATISTICS_update (session->plugin->env->stats, gettext_noop ("# TCP sessions active"), -1, GNUNET_NO); } else { GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_remove (plugin->nat_wait_conns, &session->target, session)); } if (NULL != session->client) GNUNET_SERVER_client_set_user_context (session->client, NULL); /* clean up state */ if (NULL != session->transmit_handle) { GNUNET_SERVER_notify_transmit_ready_cancel (session->transmit_handle); session->transmit_handle = NULL; } session->plugin->env->session_end (session->plugin->env->cls, session->address, session); if (NULL != session->nat_connection_timeout) { GNUNET_SCHEDULER_cancel (session->nat_connection_timeout); session->nat_connection_timeout = NULL; } while (NULL != (pm = session->pending_messages_head)) { LOG (GNUNET_ERROR_TYPE_DEBUG, (NULL != pm->transmit_cont) ? "Could not deliver message to `%s' at %s.\n" : "Could not deliver message to `%s' at %s, notifying.\n", GNUNET_i2s (&session->target), tcp_plugin_address_to_string (session->plugin, session->address->address, session->address->address_length)); GNUNET_STATISTICS_update (session->plugin->env->stats, gettext_noop ("# bytes currently in TCP buffers"), -(int64_t) pm->message_size, GNUNET_NO); GNUNET_STATISTICS_update (session->plugin->env->stats, gettext_noop ("# bytes discarded by TCP (disconnect)"), pm->message_size, GNUNET_NO); GNUNET_CONTAINER_DLL_remove (session->pending_messages_head, session->pending_messages_tail, pm); GNUNET_assert (0 < session->msgs_in_queue); session->msgs_in_queue--; GNUNET_assert (pm->message_size <= session->bytes_in_queue); session->bytes_in_queue -= pm->message_size; if (NULL != pm->transmit_cont) pm->transmit_cont (pm->transmit_cont_cls, &session->target, GNUNET_SYSERR, pm->message_size, 0); GNUNET_free (pm); } GNUNET_assert (0 == session->msgs_in_queue); GNUNET_assert (0 == session->bytes_in_queue); notify_session_monitor (session->plugin, session, GNUNET_TRANSPORT_SS_DONE); if (NULL != session->receive_delay_task) { GNUNET_SCHEDULER_cancel (session->receive_delay_task); session->receive_delay_task = NULL; } if (NULL != session->client) { GNUNET_SERVER_client_disconnect (session->client); session->client = NULL; } GNUNET_HELLO_address_free (session->address); GNUNET_assert (NULL == session->transmit_handle); GNUNET_free (session); return GNUNET_OK; } /** * Function that is called to get the keepalive factor. * #GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT is divided by this number to * calculate the interval between keepalive packets. * * @param cls closure with the `struct Plugin` * @return keepalive factor */ static unsigned int tcp_plugin_query_keepalive_factor (void *cls) { return 3; } /** * Session was idle for too long, so disconnect it * * @param cls the `struct GNUNET_ATS_Session` of the idle session */ static void session_timeout (void *cls) { struct GNUNET_ATS_Session *s = cls; struct GNUNET_TIME_Relative left; s->timeout_task = NULL; left = GNUNET_TIME_absolute_get_remaining (s->timeout); if (0 != left.rel_value_us) { /* not actually our turn yet, but let's at least update the monitor, it may think we're about to die ... */ notify_session_monitor (s->plugin, s, GNUNET_TRANSPORT_SS_UPDATE); s->timeout_task = GNUNET_SCHEDULER_add_delayed (left, &session_timeout, s); return; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Session %p was idle for %s, disconnecting\n", s, GNUNET_STRINGS_relative_time_to_string (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT, GNUNET_YES)); /* call session destroy function */ tcp_plugin_disconnect_session (s->plugin, s); } /** * Increment session timeout due to activity. * * @param s session to increment timeout for */ static void reschedule_session_timeout (struct GNUNET_ATS_Session *s) { GNUNET_assert (NULL != s->timeout_task); s->timeout = GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT); } /** * Create a new session. Also queues a welcome message. * * @param plugin the plugin * @param address the address to create the session for * @param scope network scope the address is from * @param client client to use, reference counter must have already been increased * @param is_nat this a NAT session, we should wait for a client to * connect to us from an address, then assign that to * the session * @return new session object */ static struct GNUNET_ATS_Session * create_session (struct Plugin *plugin, const struct GNUNET_HELLO_Address *address, enum GNUNET_ATS_Network_Type scope, struct GNUNET_SERVER_Client *client, int is_nat) { struct GNUNET_ATS_Session *session; struct PendingMessage *pm; if (GNUNET_YES != is_nat) GNUNET_assert (NULL != client); else GNUNET_assert (NULL == client); LOG (GNUNET_ERROR_TYPE_DEBUG, "Creating new session for peer `%4s' at address %s\n", GNUNET_i2s (&address->peer), tcp_plugin_address_to_string (plugin, address->address, address->address_length)); session = GNUNET_new (struct GNUNET_ATS_Session); session->last_activity = GNUNET_TIME_absolute_get (); session->plugin = plugin; session->is_nat = is_nat; if (NULL != client) { session->client = client; GNUNET_SERVER_client_set_user_context (client, session); } session->address = GNUNET_HELLO_address_copy (address); session->target = address->peer; session->expecting_welcome = GNUNET_YES; session->scope = scope; pm = GNUNET_malloc (sizeof (struct PendingMessage) + sizeof (struct WelcomeMessage)); pm->msg = (const char *) &pm[1]; pm->message_size = sizeof(struct WelcomeMessage); GNUNET_memcpy (&pm[1], &plugin->my_welcome, sizeof(struct WelcomeMessage)); pm->timeout = GNUNET_TIME_UNIT_FOREVER_ABS; GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# bytes currently in TCP buffers"), pm->message_size, GNUNET_NO); GNUNET_CONTAINER_DLL_insert (session->pending_messages_head, session->pending_messages_tail, pm); session->msgs_in_queue++; session->bytes_in_queue += pm->message_size; session->timeout = GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT); session->timeout_task = GNUNET_SCHEDULER_add_delayed (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT, &session_timeout, session); notify_session_monitor (session->plugin, session, GNUNET_TRANSPORT_SS_INIT); if (GNUNET_YES != is_nat) { GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# TCP sessions active"), 1, GNUNET_NO); notify_session_monitor (session->plugin, session, GNUNET_TRANSPORT_SS_UP); } else { notify_session_monitor (session->plugin, session, GNUNET_TRANSPORT_SS_HANDSHAKE); } return session; } /** * If we have pending messages, ask the server to * transmit them (schedule the respective tasks, etc.) * * @param session for which session should we do this */ static void process_pending_messages (struct GNUNET_ATS_Session *session); /** * Function called to notify a client about the socket * being ready to queue more data. "buf" will be * NULL and "size" zero if the socket was closed for * writing in the meantime. * * @param cls closure * @param size number of bytes available in @a buf * @param buf where the callee should write the message * @return number of bytes written to @a buf */ static size_t do_transmit (void *cls, size_t size, void *buf) { struct GNUNET_ATS_Session *session = cls; struct GNUNET_PeerIdentity pid; struct Plugin *plugin; struct PendingMessage *pos; struct PendingMessage *hd; struct PendingMessage *tl; struct GNUNET_TIME_Absolute now; char *cbuf; size_t ret; session->transmit_handle = NULL; plugin = session->plugin; if (NULL == buf) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Timeout trying to transmit to peer `%4s', discarding message queue.\n", GNUNET_i2s (&session->target)); /* timeout; cancel all messages that have already expired */ hd = NULL; tl = NULL; ret = 0; now = GNUNET_TIME_absolute_get (); while ( (NULL != (pos = session->pending_messages_head)) && (pos->timeout.abs_value_us <= now.abs_value_us) ) { GNUNET_CONTAINER_DLL_remove (session->pending_messages_head, session->pending_messages_tail, pos); GNUNET_assert (0 < session->msgs_in_queue); session->msgs_in_queue--; GNUNET_assert (pos->message_size <= session->bytes_in_queue); session->bytes_in_queue -= pos->message_size; LOG (GNUNET_ERROR_TYPE_DEBUG, "Failed to transmit %u byte message to `%4s'.\n", pos->message_size, GNUNET_i2s (&session->target)); ret += pos->message_size; GNUNET_CONTAINER_DLL_insert_after (hd, tl, tl, pos); } /* do this call before callbacks (so that if callbacks destroy * session, they have a chance to cancel actions done by this * call) */ process_pending_messages (session); pid = session->target; /* no do callbacks and do not use session again since * the callbacks may abort the session */ while (NULL != (pos = hd)) { GNUNET_CONTAINER_DLL_remove (hd, tl, pos); if (NULL != pos->transmit_cont) pos->transmit_cont (pos->transmit_cont_cls, &pid, GNUNET_SYSERR, pos->message_size, 0); GNUNET_free (pos); } GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# bytes currently in TCP buffers"), -(int64_t) ret, GNUNET_NO); GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# bytes discarded by TCP (timeout)"), ret, GNUNET_NO); if (0 < ret) notify_session_monitor (session->plugin, session, GNUNET_TRANSPORT_SS_UPDATE); return 0; } /* copy all pending messages that would fit */ ret = 0; cbuf = buf; hd = NULL; tl = NULL; while (NULL != (pos = session->pending_messages_head)) { if (ret + pos->message_size > size) break; GNUNET_CONTAINER_DLL_remove (session->pending_messages_head, session->pending_messages_tail, pos); GNUNET_assert (0 < session->msgs_in_queue); session->msgs_in_queue--; GNUNET_assert (pos->message_size <= session->bytes_in_queue); session->bytes_in_queue -= pos->message_size; GNUNET_assert(size >= pos->message_size); LOG (GNUNET_ERROR_TYPE_DEBUG, "Transmitting message of type %u size %u to peer %s at %s\n", ntohs (((struct GNUNET_MessageHeader *) pos->msg)->type), pos->message_size, GNUNET_i2s (&session->target), tcp_plugin_address_to_string (session->plugin, session->address->address, session->address->address_length)); /* FIXME: this GNUNET_memcpy can be up to 7% of our total runtime */ GNUNET_memcpy (cbuf, pos->msg, pos->message_size); cbuf += pos->message_size; ret += pos->message_size; size -= pos->message_size; GNUNET_CONTAINER_DLL_insert_tail (hd, tl, pos); } notify_session_monitor (session->plugin, session, GNUNET_TRANSPORT_SS_UPDATE); /* schedule 'continuation' before callbacks so that callbacks that * cancel everything don't cause us to use a session that no longer * exists... */ process_pending_messages (session); session->last_activity = GNUNET_TIME_absolute_get (); pid = session->target; /* we'll now call callbacks that may cancel the session; hence * we should not use 'session' after this point */ while (NULL != (pos = hd)) { GNUNET_CONTAINER_DLL_remove (hd, tl, pos); if (NULL != pos->transmit_cont) pos->transmit_cont (pos->transmit_cont_cls, &pid, GNUNET_OK, pos->message_size, pos->message_size); /* FIXME: include TCP overhead */ GNUNET_free (pos); } GNUNET_assert (NULL == hd); GNUNET_assert (NULL == tl); GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# bytes currently in TCP buffers"), - (int64_t) ret, GNUNET_NO); GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# bytes transmitted via TCP"), ret, GNUNET_NO); return ret; } /** * If we have pending messages, ask the server to * transmit them (schedule the respective tasks, etc.) * * @param session for which session should we do this */ static void process_pending_messages (struct GNUNET_ATS_Session *session) { struct PendingMessage *pm; GNUNET_assert (NULL != session->client); if (NULL != session->transmit_handle) return; if (NULL == (pm = session->pending_messages_head)) return; session->transmit_handle = GNUNET_SERVER_notify_transmit_ready (session->client, pm->message_size, GNUNET_TIME_absolute_get_remaining (pm->timeout), &do_transmit, session); } /** * Function that can be used by the transport service to transmit * a message using the plugin. Note that in the case of a * peer disconnecting, the continuation MUST be called * prior to the disconnect notification itself. This function * will be called with this peer's HELLO message to initiate * a fresh connection to another peer. * * @param cls closure * @param session which session must be used * @param msgbuf the message to transmit * @param msgbuf_size number of bytes in @a msgbuf * @param priority how important is the message (most plugins will * ignore message priority and just FIFO) * @param to how long to wait at most for the transmission (does not * require plugins to discard the message after the timeout, * just advisory for the desired delay; most plugins will ignore * this as well) * @param cont continuation to call once the message has * been transmitted (or if the transport is ready * for the next transmission call; or if the * peer disconnected...); can be NULL * @param cont_cls closure for @a cont * @return number of bytes used (on the physical network, with overheads); * -1 on hard errors (i.e. address invalid); 0 is a legal value * and does NOT mean that the message was not transmitted (DV) */ static ssize_t tcp_plugin_send (void *cls, struct GNUNET_ATS_Session *session, const char *msgbuf, size_t msgbuf_size, unsigned int priority, struct GNUNET_TIME_Relative to, GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls) { struct Plugin * plugin = cls; struct PendingMessage *pm; /* create new message entry */ pm = GNUNET_malloc (sizeof (struct PendingMessage) + msgbuf_size); pm->msg = (const char *) &pm[1]; GNUNET_memcpy (&pm[1], msgbuf, msgbuf_size); pm->message_size = msgbuf_size; pm->timeout = GNUNET_TIME_relative_to_absolute (to); pm->transmit_cont = cont; pm->transmit_cont_cls = cont_cls; LOG(GNUNET_ERROR_TYPE_DEBUG, "Asked to transmit %u bytes to `%s', added message to list.\n", msgbuf_size, GNUNET_i2s (&session->target)); if (GNUNET_YES == GNUNET_CONTAINER_multipeermap_contains_value (plugin->sessionmap, &session->target, session)) { GNUNET_assert (NULL != session->client); GNUNET_SERVER_client_set_timeout (session->client, GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT); GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# bytes currently in TCP buffers"), msgbuf_size, GNUNET_NO); /* append pm to pending_messages list */ GNUNET_CONTAINER_DLL_insert_tail (session->pending_messages_head, session->pending_messages_tail, pm); notify_session_monitor (session->plugin, session, GNUNET_TRANSPORT_SS_UPDATE); session->msgs_in_queue++; session->bytes_in_queue += pm->message_size; process_pending_messages (session); return msgbuf_size; } if (GNUNET_YES == GNUNET_CONTAINER_multipeermap_contains_value (plugin->nat_wait_conns, &session->target, session)) { LOG (GNUNET_ERROR_TYPE_DEBUG, "This NAT WAIT session for peer `%s' is not yet ready!\n", GNUNET_i2s (&session->target)); GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# bytes currently in TCP buffers"), msgbuf_size, GNUNET_NO); /* append pm to pending_messages list */ GNUNET_CONTAINER_DLL_insert_tail (session->pending_messages_head, session->pending_messages_tail, pm); session->msgs_in_queue++; session->bytes_in_queue += pm->message_size; notify_session_monitor (session->plugin, session, GNUNET_TRANSPORT_SS_HANDSHAKE); return msgbuf_size; } LOG (GNUNET_ERROR_TYPE_ERROR, "Invalid session %p\n", session); if (NULL != cont) cont (cont_cls, &session->target, GNUNET_SYSERR, pm->message_size, 0); GNUNET_break (0); GNUNET_free (pm); return GNUNET_SYSERR; /* session does not exist here */ } /** * Closure for #session_lookup_it(). */ struct GNUNET_ATS_SessionItCtx { /** * Address we are looking for. */ const struct GNUNET_HELLO_Address *address; /** * Where to store the session (if we found it). */ struct GNUNET_ATS_Session *result; }; /** * Look for a session by address. * * @param cls the `struct GNUNET_ATS_SessionItCtx` * @param key unused * @param value a `struct GNUNET_ATS_Session` * @return #GNUNET_YES to continue looking, #GNUNET_NO if we found the session */ static int session_lookup_it (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct GNUNET_ATS_SessionItCtx *si_ctx = cls; struct GNUNET_ATS_Session *session = value; if (0 != GNUNET_HELLO_address_cmp (si_ctx->address, session->address)) return GNUNET_YES; si_ctx->result = session; return GNUNET_NO; } /** * Task cleaning up a NAT connection attempt after timeout * * @param cls the `struct GNUNET_ATS_Session` */ static void nat_connect_timeout (void *cls) { struct GNUNET_ATS_Session *session = cls; session->nat_connection_timeout = NULL; LOG (GNUNET_ERROR_TYPE_DEBUG, "NAT WAIT connection to `%4s' at `%s' could not be established, removing session\n", GNUNET_i2s (&session->target), tcp_plugin_address_to_string (session->plugin, session->address->address, session->address->address_length)); tcp_plugin_disconnect_session (session->plugin, session); } /** * Function that will be called whenever the transport service wants to * notify the plugin that a session is still active and in use and * therefore the session timeout for this session has to be updated * * @param cls closure * @param peer which peer was the session for * @param session which session is being updated */ static void tcp_plugin_update_session_timeout (void *cls, const struct GNUNET_PeerIdentity *peer, struct GNUNET_ATS_Session *session) { reschedule_session_timeout (session); } /** * Task to signal the server that we can continue * receiving from the TCP client now. * * @param cls the `struct GNUNET_ATS_Session *` */ static void delayed_done (void *cls) { struct GNUNET_ATS_Session *session = cls; session->receive_delay_task = NULL; reschedule_session_timeout (session); GNUNET_SERVER_receive_done (session->client, GNUNET_OK); } /** * Function that will be called whenever the transport service wants to * notify the plugin that the inbound quota changed and that the plugin * should update it's delay for the next receive value * * @param cls closure * @param peer which peer was the session for * @param session which session is being updated * @param delay new delay to use for receiving */ static void tcp_plugin_update_inbound_delay (void *cls, const struct GNUNET_PeerIdentity *peer, struct GNUNET_ATS_Session *session, struct GNUNET_TIME_Relative delay) { if (NULL == session->receive_delay_task) return; LOG (GNUNET_ERROR_TYPE_DEBUG, "New inbound delay %s\n", GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_NO)); session->receive_delay = GNUNET_TIME_relative_to_absolute (delay); GNUNET_SCHEDULER_cancel (session->receive_delay_task); session->receive_delay_task = GNUNET_SCHEDULER_add_delayed (delay, &delayed_done, session); } /** * Create a new session to transmit data to the target * This session will used to send data to this peer and the plugin will * notify us by calling the env->session_end function * * @param cls closure * @param address the address to use * @return the session if the address is valid, NULL otherwise */ static struct GNUNET_ATS_Session * tcp_plugin_get_session (void *cls, const struct GNUNET_HELLO_Address *address) { struct Plugin *plugin = cls; struct GNUNET_ATS_Session *session = NULL; int af; const void *sb; size_t sbs; struct GNUNET_CONNECTION_Handle *sa; struct sockaddr_in a4; struct sockaddr_in6 a6; const struct IPv4TcpAddress *t4; const struct IPv6TcpAddress *t6; unsigned int options; enum GNUNET_ATS_Network_Type net_type; unsigned int is_natd = GNUNET_NO; size_t addrlen; #ifdef TCP_STEALTH struct GNUNET_NETWORK_Handle *s; #endif addrlen = address->address_length; LOG (GNUNET_ERROR_TYPE_DEBUG, "Trying to get session for `%s' address of peer `%s'\n", tcp_plugin_address_to_string (plugin, address->address, address->address_length), GNUNET_i2s (&address->peer)); if (GNUNET_HELLO_address_check_option (address, GNUNET_HELLO_ADDRESS_INFO_INBOUND)) { GNUNET_break (0); return NULL; } /* look for existing session */ if (GNUNET_YES == GNUNET_CONTAINER_multipeermap_contains (plugin->sessionmap, &address->peer)) { struct GNUNET_ATS_SessionItCtx si_ctx; si_ctx.address = address; si_ctx.result = NULL; GNUNET_CONTAINER_multipeermap_get_multiple (plugin->sessionmap, &address->peer, &session_lookup_it, &si_ctx); if (NULL != si_ctx.result) { session = si_ctx.result; LOG (GNUNET_ERROR_TYPE_DEBUG, "Found existing session for `%s' address `%s'\n", GNUNET_i2s (&address->peer), tcp_plugin_address_to_string (plugin, address->address, address->address_length)); return session; } } if (addrlen == sizeof(struct IPv6TcpAddress)) { GNUNET_assert (NULL != address->address); /* make static analysis happy */ t6 = address->address; options = t6->options; af = AF_INET6; memset (&a6, 0, sizeof(a6)); #if HAVE_SOCKADDR_IN_SIN_LEN a6.sin6_len = sizeof (a6); #endif a6.sin6_family = AF_INET6; a6.sin6_port = t6->t6_port; if (t6->t6_port == 0) is_natd = GNUNET_YES; GNUNET_memcpy (&a6.sin6_addr, &t6->ipv6_addr, sizeof(struct in6_addr)); sb = &a6; sbs = sizeof(a6); } else if (addrlen == sizeof(struct IPv4TcpAddress)) { GNUNET_assert(NULL != address->address); /* make static analysis happy */ t4 = address->address; options = t4->options; af = AF_INET; memset (&a4, 0, sizeof(a4)); #if HAVE_SOCKADDR_IN_SIN_LEN a4.sin_len = sizeof (a4); #endif a4.sin_family = AF_INET; a4.sin_port = t4->t4_port; if (t4->t4_port == 0) is_natd = GNUNET_YES; a4.sin_addr.s_addr = t4->ipv4_addr; sb = &a4; sbs = sizeof(a4); } else { GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# requests to create session with invalid address"), 1, GNUNET_NO); return NULL; } net_type = plugin->env->get_address_type (plugin->env->cls, sb, sbs); GNUNET_break (net_type != GNUNET_ATS_NET_UNSPECIFIED); if ( (is_natd == GNUNET_YES) && (addrlen == sizeof(struct IPv6TcpAddress)) ) { /* NAT client only works with IPv4 addresses */ return NULL; } if (plugin->cur_connections >= plugin->max_connections) { /* saturated */ return NULL; } if ( (is_natd == GNUNET_YES) && (GNUNET_YES == GNUNET_CONTAINER_multipeermap_contains (plugin->nat_wait_conns, &address->peer))) { /* Only do one NAT punch attempt per peer identity */ return NULL; } if ( (is_natd == GNUNET_YES) && (NULL != plugin->nat) && (GNUNET_NO == GNUNET_CONTAINER_multipeermap_contains (plugin->nat_wait_conns, &address->peer))) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Found valid IPv4 NAT address (creating session)!\n"); session = create_session (plugin, address, net_type, NULL, GNUNET_YES); session->nat_connection_timeout = GNUNET_SCHEDULER_add_delayed (NAT_TIMEOUT, &nat_connect_timeout, session); GNUNET_assert (GNUNET_OK == GNUNET_CONTAINER_multipeermap_put (plugin->nat_wait_conns, &session->target, session, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)); LOG (GNUNET_ERROR_TYPE_DEBUG, "Created NAT WAIT connection to `%4s' at `%s'\n", GNUNET_i2s (&session->target), GNUNET_a2s (sb, sbs)); if (GNUNET_OK == GNUNET_NAT_run_client (plugin->nat, &a4)) { return session; } else { LOG(GNUNET_ERROR_TYPE_DEBUG, "Running NAT client for `%4s' at `%s' failed\n", GNUNET_i2s (&session->target), GNUNET_a2s (sb, sbs)); tcp_plugin_disconnect_session (plugin, session); return NULL; } } /* create new outbound session */ if (0 != (options & TCP_OPTIONS_TCP_STEALTH)) { #ifdef TCP_STEALTH s = GNUNET_NETWORK_socket_create (af, SOCK_STREAM, 0); if (NULL == s) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK, "socket"); sa = NULL; } else { if ( (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (s, IPPROTO_TCP, TCP_STEALTH, &session->target, sizeof (struct GNUNET_PeerIdentity))) || (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (s, IPPROTO_TCP, TCP_STEALTH_INTEGRITY, &plugin->my_welcome, sizeof (struct WelcomeMessage))) ) { /* TCP STEALTH not supported by kernel */ GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (s)); sa = NULL; } else { sa = GNUNET_CONNECTION_connect_socket (s, sb, sbs); } } #else sa = NULL; #endif } else { sa = GNUNET_CONNECTION_create_from_sockaddr (af, sb, sbs); } if (NULL == sa) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Failed to create connection to `%4s' at `%s'\n", GNUNET_i2s (&address->peer), GNUNET_a2s (sb, sbs)); return NULL; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Asked to transmit to `%4s', creating fresh session using address `%s'.\n", GNUNET_i2s (&address->peer), GNUNET_a2s (sb, sbs)); session = create_session (plugin, address, net_type, GNUNET_SERVER_connect_socket (plugin->server, sa), GNUNET_NO); (void) GNUNET_CONTAINER_multipeermap_put (plugin->sessionmap, &session->target, session, GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE); /* Send TCP Welcome */ process_pending_messages (session); return session; } /** * We have been asked to destroy all connections to a particular peer. * This function is called on each applicable session and must tear it * down. * * @param cls the `struct Plugin *` * @param key the peer which the session belongs to (unused) * @param value the `struct GNUNET_ATS_Session` * @return #GNUNET_YES (continue to iterate) */ static int session_disconnect_it (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct Plugin *plugin = cls; struct GNUNET_ATS_Session *session = value; GNUNET_STATISTICS_update (session->plugin->env->stats, gettext_noop ("# transport-service disconnect requests for TCP"), 1, GNUNET_NO); tcp_plugin_disconnect_session (plugin, session); return GNUNET_YES; } /** * Function that can be called to force a disconnect from the * specified neighbour. This should also cancel all previously * scheduled transmissions. Obviously the transmission may have been * partially completed already, which is OK. The plugin is supposed * to close the connection (if applicable) and no longer call the * transmit continuation(s). * * Finally, plugin MUST NOT call the services's receive function to * notify the service that the connection to the specified target was * closed after a getting this call. * * @param cls closure * @param target peer for which the last transmission is * to be cancelled */ static void tcp_plugin_disconnect (void *cls, const struct GNUNET_PeerIdentity *target) { struct Plugin *plugin = cls; LOG (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting peer `%4s'\n", GNUNET_i2s (target)); GNUNET_CONTAINER_multipeermap_get_multiple (plugin->sessionmap, target, &session_disconnect_it, plugin); GNUNET_CONTAINER_multipeermap_get_multiple (plugin->nat_wait_conns, target, &session_disconnect_it, plugin); } /** * We are processing an address pretty printing request and finished * the IP resolution (if applicable). Append our port and forward the * result. If called with @a hostname NULL, we are done and should * clean up the pretty printer (otherwise, there might be multiple * hostnames for the IP address and we might receive more). * * @param cls the `struct PrettyPrinterContext *` * @param hostname hostname part of the address */ static void append_port (void *cls, const char *hostname) { struct PrettyPrinterContext *ppc = cls; struct Plugin *plugin = ppc->plugin; char *ret; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "append_port called with hostname `%s'\n", hostname); if (NULL == hostname) { /* Final call, done */ ppc->resolver_handle = NULL; GNUNET_CONTAINER_DLL_remove (plugin->ppc_dll_head, plugin->ppc_dll_tail, ppc); ppc->asc (ppc->asc_cls, NULL, GNUNET_OK); GNUNET_free (ppc); return; } if (GNUNET_YES == ppc->ipv6) GNUNET_asprintf (&ret, "%s.%u.[%s]:%d", PLUGIN_NAME, ppc->options, hostname, ppc->port); else GNUNET_asprintf (&ret, "%s.%u.%s:%d", PLUGIN_NAME, ppc->options, hostname, ppc->port); ppc->asc (ppc->asc_cls, ret, GNUNET_OK); GNUNET_free (ret); } /** * Convert the transports address to a nice, human-readable format. * * @param cls closure with the `struct Plugin` * @param type name of the transport that generated the address * @param addr one of the addresses of the host, NULL for the last address * the specific address format depends on the transport * @param addrlen length of the @a addr * @param numeric should (IP) addresses be displayed in numeric form? * @param timeout after how long should we give up? * @param asc function to call on each string * @param asc_cls closure for @a asc */ static void tcp_plugin_address_pretty_printer (void *cls, const char *type, const void *addr, size_t addrlen, int numeric, struct GNUNET_TIME_Relative timeout, GNUNET_TRANSPORT_AddressStringCallback asc, void *asc_cls) { struct Plugin *plugin = cls; struct PrettyPrinterContext *ppc; const void *sb; size_t sbs; struct sockaddr_in a4; struct sockaddr_in6 a6; const struct IPv4TcpAddress *t4; const struct IPv6TcpAddress *t6; uint16_t port; uint32_t options; if (sizeof(struct IPv6TcpAddress) == addrlen) { t6 = addr; memset (&a6, 0, sizeof(a6)); a6.sin6_family = AF_INET6; a6.sin6_port = t6->t6_port; GNUNET_memcpy (&a6.sin6_addr, &t6->ipv6_addr, sizeof(struct in6_addr)); port = ntohs (t6->t6_port); options = ntohl (t6->options); sb = &a6; sbs = sizeof(a6); } else if (sizeof(struct IPv4TcpAddress) == addrlen) { t4 = addr; memset (&a4, 0, sizeof(a4)); a4.sin_family = AF_INET; a4.sin_port = t4->t4_port; a4.sin_addr.s_addr = t4->ipv4_addr; port = ntohs (t4->t4_port); options = ntohl (t4->options); sb = &a4; sbs = sizeof(a4); } else { /* invalid address */ LOG (GNUNET_ERROR_TYPE_WARNING, _("Unexpected address length: %u bytes\n"), (unsigned int) addrlen); asc (asc_cls, NULL, GNUNET_SYSERR); asc (asc_cls, NULL, GNUNET_OK); return; } ppc = GNUNET_new (struct PrettyPrinterContext); ppc->plugin = plugin; if (addrlen == sizeof(struct IPv6TcpAddress)) ppc->ipv6 = GNUNET_YES; else ppc->ipv6 = GNUNET_NO; ppc->asc = asc; ppc->asc_cls = asc_cls; ppc->port = port; ppc->options = options; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Starting DNS reverse lookup\n"); ppc->resolver_handle = GNUNET_RESOLVER_hostname_get (sb, sbs, ! numeric, timeout, &append_port, ppc); if (NULL == ppc->resolver_handle) { GNUNET_break (0); GNUNET_free (ppc); return; } GNUNET_CONTAINER_DLL_insert (plugin->ppc_dll_head, plugin->ppc_dll_tail, ppc); } /** * Check if the given port is plausible (must be either our listen * port or our advertised port), or any port if we are behind NAT * and do not have a port open. If it is neither, we return * #GNUNET_SYSERR. * * @param plugin global variables * @param in_port port number to check * @return #GNUNET_OK if port is either open_port or adv_port */ static int check_port (struct Plugin *plugin, uint16_t in_port) { if ( (in_port == plugin->adv_port) || (in_port == plugin->open_port) ) return GNUNET_OK; return GNUNET_SYSERR; } /** * Function that will be called to check if a binary address for this * plugin is well-formed and corresponds to an address for THIS peer * (as per our configuration). Naturally, if absolutely necessary, * plugins can be a bit conservative in their answer, but in general * plugins should make sure that the address does not redirect * traffic to a 3rd party that might try to man-in-the-middle our * traffic. * * @param cls closure, our `struct Plugin *` * @param addr pointer to the address * @param addrlen length of @a addr * @return #GNUNET_OK if this is a plausible address for this peer * and transport, #GNUNET_SYSERR if not */ static int tcp_plugin_check_address (void *cls, const void *addr, size_t addrlen) { struct Plugin *plugin = cls; const struct IPv4TcpAddress *v4; const struct IPv6TcpAddress *v6; if ( (addrlen != sizeof(struct IPv4TcpAddress)) && (addrlen != sizeof(struct IPv6TcpAddress)) ) { GNUNET_break_op (0); return GNUNET_SYSERR; } if (addrlen == sizeof(struct IPv4TcpAddress)) { v4 = (const struct IPv4TcpAddress *) addr; if (0 != memcmp (&v4->options, &plugin->myoptions, sizeof(uint32_t))) { GNUNET_break (0); return GNUNET_SYSERR; } if (GNUNET_OK != check_port (plugin, ntohs (v4->t4_port))) return GNUNET_SYSERR; if (GNUNET_OK != GNUNET_NAT_test_address (plugin->nat, &v4->ipv4_addr, sizeof (struct in_addr))) return GNUNET_SYSERR; } else { v6 = (const struct IPv6TcpAddress *) addr; if (IN6_IS_ADDR_LINKLOCAL (&v6->ipv6_addr)) { GNUNET_break_op (0); return GNUNET_SYSERR; } if (0 != memcmp (&v6->options, &plugin->myoptions, sizeof (uint32_t))) { GNUNET_break (0); return GNUNET_SYSERR; } if (GNUNET_OK != check_port (plugin, ntohs (v6->t6_port))) return GNUNET_SYSERR; if (GNUNET_OK != GNUNET_NAT_test_address (plugin->nat, &v6->ipv6_addr, sizeof(struct in6_addr))) return GNUNET_SYSERR; } return GNUNET_OK; } /** * We've received a nat probe from this peer via TCP. Finish * creating the client session and resume sending of queued * messages. * * @param cls closure * @param client identification of the client * @param message the actual message */ static void handle_tcp_nat_probe (void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { struct Plugin *plugin = cls; struct GNUNET_ATS_Session *session; const struct TCP_NAT_ProbeMessage *tcp_nat_probe; size_t alen; void *vaddr; struct IPv4TcpAddress *t4; struct IPv6TcpAddress *t6; const struct sockaddr_in *s4; const struct sockaddr_in6 *s6; LOG (GNUNET_ERROR_TYPE_DEBUG, "Received NAT probe\n"); /* We have received a TCP NAT probe, meaning we (hopefully) initiated * a connection to this peer by running gnunet-nat-client. This peer * received the punch message and now wants us to use the new connection * as the default for that peer. Do so and then send a WELCOME message * so we can really be connected! */ if (ntohs (message->size) != sizeof(struct TCP_NAT_ProbeMessage)) { GNUNET_break_op(0); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); return; } tcp_nat_probe = (const struct TCP_NAT_ProbeMessage *) message; if (0 == memcmp (&tcp_nat_probe->clientIdentity, plugin->env->my_identity, sizeof(struct GNUNET_PeerIdentity))) { /* refuse connections from ourselves */ GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); return; } session = GNUNET_CONTAINER_multipeermap_get (plugin->nat_wait_conns, &tcp_nat_probe->clientIdentity); if (NULL == session) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Did NOT find session for NAT probe!\n"); GNUNET_SERVER_receive_done (client, GNUNET_OK); return; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Found session for NAT probe!\n"); if (NULL != session->nat_connection_timeout) { GNUNET_SCHEDULER_cancel (session->nat_connection_timeout); session->nat_connection_timeout = NULL; } if (GNUNET_OK != GNUNET_SERVER_client_get_address (client, &vaddr, &alen)) { GNUNET_break(0); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); tcp_plugin_disconnect_session (plugin, session); return; } GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_remove (plugin->nat_wait_conns, &tcp_nat_probe->clientIdentity, session)); GNUNET_SERVER_client_set_user_context (client, session); (void) GNUNET_CONTAINER_multipeermap_put (plugin->sessionmap, &session->target, session, GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE); session->last_activity = GNUNET_TIME_absolute_get (); LOG (GNUNET_ERROR_TYPE_DEBUG, "Found address `%s' for incoming connection\n", GNUNET_a2s (vaddr, alen)); switch (((const struct sockaddr *) vaddr)->sa_family) { case AF_INET: s4 = vaddr; t4 = GNUNET_new (struct IPv4TcpAddress); t4->options = htonl (TCP_OPTIONS_NONE); t4->t4_port = s4->sin_port; t4->ipv4_addr = s4->sin_addr.s_addr; session->address = GNUNET_HELLO_address_allocate (&tcp_nat_probe->clientIdentity, PLUGIN_NAME, &t4, sizeof(struct IPv4TcpAddress), GNUNET_HELLO_ADDRESS_INFO_NONE); break; case AF_INET6: s6 = vaddr; t6 = GNUNET_new (struct IPv6TcpAddress); t6->options = htonl (TCP_OPTIONS_NONE); t6->t6_port = s6->sin6_port; GNUNET_memcpy (&t6->ipv6_addr, &s6->sin6_addr, sizeof(struct in6_addr)); session->address = GNUNET_HELLO_address_allocate (&tcp_nat_probe->clientIdentity, PLUGIN_NAME, &t6, sizeof(struct IPv6TcpAddress), GNUNET_HELLO_ADDRESS_INFO_NONE); break; default: GNUNET_break_op(0); LOG(GNUNET_ERROR_TYPE_DEBUG, "Bad address for incoming connection!\n"); GNUNET_free(vaddr); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); tcp_plugin_disconnect_session (plugin, session); return; } GNUNET_free (vaddr); GNUNET_break (NULL == session->client); session->client = client; GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# TCP sessions active"), 1, GNUNET_NO); process_pending_messages (session); GNUNET_SERVER_receive_done (client, GNUNET_OK); } /** * We've received a welcome from this peer via TCP. Possibly create a * fresh client record and send back our welcome. * * @param cls closure * @param client identification of the client * @param message the actual message */ static void handle_tcp_welcome (void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { struct Plugin *plugin = cls; const struct WelcomeMessage *wm = (const struct WelcomeMessage *) message; struct GNUNET_HELLO_Address *address; struct GNUNET_ATS_Session *session; size_t alen; void *vaddr; struct IPv4TcpAddress t4; struct IPv6TcpAddress t6; const struct sockaddr_in *s4; const struct sockaddr_in6 *s6; if (0 == memcmp (&wm->clientIdentity, plugin->env->my_identity, sizeof(struct GNUNET_PeerIdentity))) { /* refuse connections from ourselves */ GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); if (GNUNET_OK == GNUNET_SERVER_client_get_address (client, &vaddr, &alen)) { LOG (GNUNET_ERROR_TYPE_INFO, "Received WELCOME message from my own identity `%4s' on address `%s'\n", GNUNET_i2s (&wm->clientIdentity), GNUNET_a2s (vaddr, alen)); GNUNET_free(vaddr); } return; } LOG(GNUNET_ERROR_TYPE_DEBUG, "Received WELCOME message from `%4s' %p\n", GNUNET_i2s (&wm->clientIdentity), client); GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# TCP WELCOME messages received"), 1, GNUNET_NO); session = lookup_session_by_client (plugin, client); if (NULL != session) { if (GNUNET_OK == GNUNET_SERVER_client_get_address (client, &vaddr, &alen)) { LOG (GNUNET_ERROR_TYPE_DEBUG, "Found existing session %p for peer `%s'\n", session, GNUNET_a2s (vaddr, alen)); GNUNET_free (vaddr); } } else { if (GNUNET_OK == GNUNET_SERVER_client_get_address (client, &vaddr, &alen)) { if (alen == sizeof(struct sockaddr_in)) { s4 = vaddr; memset (&t4, '\0', sizeof (t4)); t4.options = htonl (TCP_OPTIONS_NONE); t4.t4_port = s4->sin_port; t4.ipv4_addr = s4->sin_addr.s_addr; address = GNUNET_HELLO_address_allocate (&wm->clientIdentity, PLUGIN_NAME, &t4, sizeof(t4), GNUNET_HELLO_ADDRESS_INFO_INBOUND); } else if (alen == sizeof(struct sockaddr_in6)) { s6 = vaddr; memset (&t6, '\0', sizeof (t6)); t6.options = htonl (TCP_OPTIONS_NONE); t6.t6_port = s6->sin6_port; GNUNET_memcpy (&t6.ipv6_addr, &s6->sin6_addr, sizeof(struct in6_addr)); address = GNUNET_HELLO_address_allocate (&wm->clientIdentity, PLUGIN_NAME, &t6, sizeof (t6), GNUNET_HELLO_ADDRESS_INFO_INBOUND); } else { GNUNET_break (0); GNUNET_free_non_null (vaddr); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); return; } session = create_session (plugin, address, plugin->env->get_address_type (plugin->env->cls, vaddr, alen), client, GNUNET_NO); GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != session->scope); GNUNET_HELLO_address_free (address); LOG (GNUNET_ERROR_TYPE_DEBUG, "Creating new%s session %p for peer `%s' client %p\n", GNUNET_HELLO_address_check_option (session->address, GNUNET_HELLO_ADDRESS_INFO_INBOUND) ? " inbound" : "", session, tcp_plugin_address_to_string (plugin, session->address->address, session->address->address_length), client); GNUNET_free (vaddr); (void) GNUNET_CONTAINER_multipeermap_put (plugin->sessionmap, &session->target, session, GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE); /* Notify transport and ATS about new session */ plugin->env->session_start (plugin->env->cls, session->address, session, session->scope); } else { LOG(GNUNET_ERROR_TYPE_DEBUG, "Did not obtain TCP socket address for incoming connection\n"); GNUNET_break(0); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); return; } } if (session->expecting_welcome != GNUNET_YES) { GNUNET_break_op(0); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); GNUNET_break(0); return; } session->last_activity = GNUNET_TIME_absolute_get (); session->expecting_welcome = GNUNET_NO; process_pending_messages (session); GNUNET_SERVER_client_set_timeout (client, GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT); GNUNET_SERVER_receive_done (client, GNUNET_OK); } /** * We've received data for this peer via TCP. Unbox, * compute latency and forward. * * @param cls closure * @param client identification of the client * @param message the actual message */ static void handle_tcp_data (void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { struct Plugin *plugin = cls; struct GNUNET_ATS_Session *session; struct GNUNET_TIME_Relative delay; uint16_t type; type = ntohs (message->type); if ( (GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME == type) || (GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_NAT_PROBE == type) ) { /* We don't want to propagate WELCOME and NAT Probe messages up! */ GNUNET_SERVER_receive_done (client, GNUNET_OK); return; } session = lookup_session_by_client (plugin, client); if (NULL == session) { /* No inbound session found */ void *vaddr; size_t alen; GNUNET_SERVER_client_get_address (client, &vaddr, &alen); LOG (GNUNET_ERROR_TYPE_ERROR, "Received unexpected %u bytes of type %u from `%s'\n", (unsigned int) ntohs (message->size), (unsigned int) ntohs (message->type), GNUNET_a2s (vaddr, alen)); GNUNET_break_op(0); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); GNUNET_free_non_null (vaddr); return; } if (GNUNET_YES == session->expecting_welcome) { /* Session is expecting WELCOME message */ void *vaddr; size_t alen; GNUNET_SERVER_client_get_address (client, &vaddr, &alen); LOG (GNUNET_ERROR_TYPE_ERROR, "Received unexpected %u bytes of type %u from `%s'\n", (unsigned int) ntohs (message->size), (unsigned int) ntohs (message->type), GNUNET_a2s (vaddr, alen)); GNUNET_break_op(0); GNUNET_SERVER_receive_done (client, GNUNET_SYSERR); GNUNET_free_non_null (vaddr); return; } session->last_activity = GNUNET_TIME_absolute_get (); LOG (GNUNET_ERROR_TYPE_DEBUG, "Passing %u bytes of type %u from `%4s' to transport service.\n", (unsigned int) ntohs (message->size), (unsigned int) ntohs (message->type), GNUNET_i2s (&session->target)); GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# bytes received via TCP"), ntohs (message->size), GNUNET_NO); GNUNET_assert (GNUNET_CONTAINER_multipeermap_contains_value (plugin->sessionmap, &session->target, session)); delay = plugin->env->receive (plugin->env->cls, session->address, session, message); reschedule_session_timeout (session); if (0 == delay.rel_value_us) { GNUNET_SERVER_receive_done (client, GNUNET_OK); } else { LOG (GNUNET_ERROR_TYPE_DEBUG, "Throttling receiving from `%s' for %s\n", GNUNET_i2s (&session->target), GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES)); GNUNET_SERVER_disable_receive_done_warning (client); GNUNET_assert (NULL == session->receive_delay_task); session->receive_delay_task = GNUNET_SCHEDULER_add_delayed (delay, &delayed_done, session); } } /** * Function called whenever a peer is connected on the "SERVER" level. * Increments number of active connections and suspends server if we * have reached the limit. * * @param cls closure * @param client identification of the client */ static void connect_notify (void *cls, struct GNUNET_SERVER_Client *client) { struct Plugin *plugin = cls; if (NULL == client) return; plugin->cur_connections++; GNUNET_STATISTICS_set (plugin->env->stats, gettext_noop ("# TCP server connections active"), plugin->cur_connections, GNUNET_NO); GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# TCP server connect events"), 1, GNUNET_NO); if (plugin->cur_connections != plugin->max_connections) return; GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("TCP connection limit reached, suspending server\n")); GNUNET_STATISTICS_update (plugin->env->stats, gettext_noop ("# TCP service suspended"), 1, GNUNET_NO); GNUNET_SERVER_suspend (plugin->server); /* Maximum number of connections rechead */ } /** * Function called whenever a peer is disconnected on the "SERVER" * level. Cleans up the connection, decrements number of active * connections and if applicable resumes listening. * * @param cls closure * @param client identification of the client */ static void disconnect_notify (void *cls, struct GNUNET_SERVER_Client *client) { struct Plugin *plugin = cls; struct GNUNET_ATS_Session *session; if (NULL == client) return; GNUNET_assert (plugin->cur_connections >= 1); plugin->cur_connections--; session = lookup_session_by_client (plugin, client); if (NULL == session) return; /* unknown, nothing to do */ LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying session of `%4s' with %s due to network-level disconnect.\n", GNUNET_i2s (&session->target), tcp_plugin_address_to_string (session->plugin, session->address->address, session->address->address_length)); if (plugin->cur_connections == plugin->max_connections) { GNUNET_STATISTICS_update (session->plugin->env->stats, gettext_noop ("# TCP service resumed"), 1, GNUNET_NO); GNUNET_SERVER_resume (plugin->server); /* Resume server */ } GNUNET_STATISTICS_set (plugin->env->stats, gettext_noop ("# TCP server connections active"), plugin->cur_connections, GNUNET_NO); GNUNET_STATISTICS_update (session->plugin->env->stats, gettext_noop ("# network-level TCP disconnect events"), 1, GNUNET_NO); tcp_plugin_disconnect_session (plugin, session); } /** * We can now send a probe message, copy into buffer to really send. * * @param cls closure, a `struct TCPProbeContext` * @param size max size to copy * @param buf buffer to copy message to * @return number of bytes copied into @a buf */ static size_t notify_send_probe (void *cls, size_t size, void *buf) { struct TCPProbeContext *tcp_probe_ctx = cls; struct Plugin *plugin = tcp_probe_ctx->plugin; size_t ret; tcp_probe_ctx->transmit_handle = NULL; GNUNET_CONTAINER_DLL_remove (plugin->probe_head, plugin->probe_tail, tcp_probe_ctx); if (NULL == buf) { GNUNET_CONNECTION_destroy (tcp_probe_ctx->sock); GNUNET_free(tcp_probe_ctx); return 0; } GNUNET_assert(size >= sizeof(tcp_probe_ctx->message)); GNUNET_memcpy (buf, &tcp_probe_ctx->message, sizeof(tcp_probe_ctx->message)); GNUNET_SERVER_connect_socket (tcp_probe_ctx->plugin->server, tcp_probe_ctx->sock); ret = sizeof(tcp_probe_ctx->message); GNUNET_free (tcp_probe_ctx); return ret; } /** * Function called by the NAT subsystem suggesting another peer wants * to connect to us via connection reversal. Try to connect back to the * given IP. * * @param cls closure * @param addr address to try * @param addrlen number of bytes in @a addr */ static void try_connection_reversal (void *cls, const struct sockaddr *addr, socklen_t addrlen) { struct Plugin *plugin = cls; struct GNUNET_CONNECTION_Handle *sock; struct TCPProbeContext *tcp_probe_ctx; /** * We have received an ICMP response, ostensibly from a peer * that wants to connect to us! Send a message to establish a connection. */ sock = GNUNET_CONNECTION_create_from_sockaddr (AF_INET, addr, addrlen); if (NULL == sock) { /* failed for some odd reason (out of sockets?); ignore attempt */ return; } tcp_probe_ctx = GNUNET_new (struct TCPProbeContext); tcp_probe_ctx->message.header.size = htons (sizeof (struct TCP_NAT_ProbeMessage)); tcp_probe_ctx->message.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_NAT_PROBE); tcp_probe_ctx->message.clientIdentity = *plugin->env->my_identity; tcp_probe_ctx->plugin = plugin; tcp_probe_ctx->sock = sock; GNUNET_CONTAINER_DLL_insert (plugin->probe_head, plugin->probe_tail, tcp_probe_ctx); tcp_probe_ctx->transmit_handle = GNUNET_CONNECTION_notify_transmit_ready (sock, ntohs (tcp_probe_ctx->message.header.size), GNUNET_TIME_UNIT_FOREVER_REL, ¬ify_send_probe, tcp_probe_ctx); } /** * Function obtain the network type for a session * * @param cls closure (`struct Plugin *`) * @param session the session * @return the network type in HBO or #GNUNET_SYSERR */ static enum GNUNET_ATS_Network_Type tcp_plugin_get_network (void *cls, struct GNUNET_ATS_Session *session) { return session->scope; } /** * Function obtain the network type for an address. * * @param cls closure (`struct Plugin *`) * @param address the address * @return the network type */ static enum GNUNET_ATS_Network_Type tcp_plugin_get_network_for_address (void *cls, const struct GNUNET_HELLO_Address *address) { struct Plugin *plugin = cls; size_t addrlen; struct sockaddr_in a4; struct sockaddr_in6 a6; const struct IPv4TcpAddress *t4; const struct IPv6TcpAddress *t6; const void *sb; size_t sbs; addrlen = address->address_length; if (addrlen == sizeof(struct IPv6TcpAddress)) { GNUNET_assert (NULL != address->address); /* make static analysis happy */ t6 = address->address; memset (&a6, 0, sizeof(a6)); #if HAVE_SOCKADDR_IN_SIN_LEN a6.sin6_len = sizeof (a6); #endif a6.sin6_family = AF_INET6; a6.sin6_port = t6->t6_port; GNUNET_memcpy (&a6.sin6_addr, &t6->ipv6_addr, sizeof(struct in6_addr)); sb = &a6; sbs = sizeof(a6); } else if (addrlen == sizeof(struct IPv4TcpAddress)) { GNUNET_assert (NULL != address->address); /* make static analysis happy */ t4 = address->address; memset (&a4, 0, sizeof(a4)); #if HAVE_SOCKADDR_IN_SIN_LEN a4.sin_len = sizeof (a4); #endif a4.sin_family = AF_INET; a4.sin_port = t4->t4_port; a4.sin_addr.s_addr = t4->ipv4_addr; sb = &a4; sbs = sizeof(a4); } else { GNUNET_break (0); return GNUNET_ATS_NET_UNSPECIFIED; } return plugin->env->get_address_type (plugin->env->cls, sb, sbs); } /** * Return information about the given session to the * monitor callback. * * @param cls the `struct Plugin` with the monitor callback (`sic`) * @param peer peer we send information about * @param value our `struct GNUNET_ATS_Session` to send information about * @return #GNUNET_OK (continue to iterate) */ static int send_session_info_iter (void *cls, const struct GNUNET_PeerIdentity *peer, void *value) { struct Plugin *plugin = cls; struct GNUNET_ATS_Session *session = value; notify_session_monitor (plugin, session, GNUNET_TRANSPORT_SS_INIT); /* FIXME: cannot tell if this is up or not from current session state... */ notify_session_monitor (plugin, session, GNUNET_TRANSPORT_SS_UP); return GNUNET_OK; } /** * Begin monitoring sessions of a plugin. There can only * be one active monitor per plugin (i.e. if there are * multiple monitors, the transport service needs to * multiplex the generated events over all of them). * * @param cls closure of the plugin * @param sic callback to invoke, NULL to disable monitor; * plugin will being by iterating over all active * sessions immediately and then enter monitor mode * @param sic_cls closure for @a sic */ static void tcp_plugin_setup_monitor (void *cls, GNUNET_TRANSPORT_SessionInfoCallback sic, void *sic_cls) { struct Plugin *plugin = cls; plugin->sic = sic; plugin->sic_cls = sic_cls; if (NULL != sic) { GNUNET_CONTAINER_multipeermap_iterate (plugin->sessionmap, &send_session_info_iter, plugin); /* signal end of first iteration */ sic (sic_cls, NULL, NULL); } } /** * Entry point for the plugin. * * @param cls closure, the `struct GNUNET_TRANSPORT_PluginEnvironment *` * @return the `struct GNUNET_TRANSPORT_PluginFunctions *` or NULL on error */ void * libgnunet_plugin_transport_tcp_init (void *cls) { static const struct GNUNET_SERVER_MessageHandler my_handlers[] = { { &handle_tcp_welcome, NULL, GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME, sizeof(struct WelcomeMessage) }, { &handle_tcp_nat_probe, NULL, GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_NAT_PROBE, sizeof(struct TCP_NAT_ProbeMessage) }, { &handle_tcp_data, NULL, GNUNET_MESSAGE_TYPE_ALL, 0 }, { NULL, NULL, 0, 0 } }; struct GNUNET_TRANSPORT_PluginEnvironment *env = cls; struct GNUNET_TRANSPORT_PluginFunctions *api; struct Plugin *plugin; struct GNUNET_SERVICE_Context *service; unsigned long long aport; unsigned long long bport; unsigned long long max_connections; unsigned int i; struct GNUNET_TIME_Relative idle_timeout; #ifdef TCP_STEALTH struct GNUNET_NETWORK_Handle *const*lsocks; #endif int ret; int ret_s; struct sockaddr **addrs; socklen_t *addrlens; if (NULL == env->receive) { /* run in 'stub' mode (i.e. as part of gnunet-peerinfo), don't fully initialze the plugin or the API */ api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions); api->cls = NULL; api->address_pretty_printer = &tcp_plugin_address_pretty_printer; api->address_to_string = &tcp_plugin_address_to_string; api->string_to_address = &tcp_plugin_string_to_address; return api; } GNUNET_assert (NULL != env->cfg); if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_number (env->cfg, "transport-tcp", "MAX_CONNECTIONS", &max_connections)) max_connections = 128; aport = 0; if ((GNUNET_OK != GNUNET_CONFIGURATION_get_value_number (env->cfg, "transport-tcp", "PORT", &bport)) || (bport > 65535) || ((GNUNET_OK == GNUNET_CONFIGURATION_get_value_number (env->cfg, "transport-tcp", "ADVERTISED-PORT", &aport)) && (aport > 65535) )) { LOG(GNUNET_ERROR_TYPE_ERROR, _("Require valid port number for service `%s' in configuration!\n"), "transport-tcp"); return NULL ; } if (0 == aport) aport = bport; if (0 == bport) aport = 0; if (0 != bport) { service = GNUNET_SERVICE_start ("transport-tcp", env->cfg, GNUNET_SERVICE_OPTION_NONE); if (NULL == service) { LOG (GNUNET_ERROR_TYPE_WARNING, _("Failed to start service.\n")); return NULL; } } else service = NULL; api = NULL; plugin = GNUNET_new (struct Plugin); plugin->sessionmap = GNUNET_CONTAINER_multipeermap_create (max_connections, GNUNET_YES); plugin->max_connections = max_connections; plugin->open_port = bport; plugin->adv_port = aport; plugin->env = env; plugin->my_welcome.header.size = htons (sizeof(struct WelcomeMessage)); plugin->my_welcome.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME); plugin->my_welcome.clientIdentity = *plugin->env->my_identity; if ( (NULL != service) && (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno (env->cfg, "transport-tcp", "TCP_STEALTH")) ) { #ifdef TCP_STEALTH plugin->myoptions |= TCP_OPTIONS_TCP_STEALTH; lsocks = GNUNET_SERVICE_get_listen_sockets (service); if (NULL != lsocks) { uint32_t len = sizeof (struct WelcomeMessage); for (i=0;NULL!=lsocks[i];i++) { if ( (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (lsocks[i], IPPROTO_TCP, TCP_STEALTH, env->my_identity, sizeof (struct GNUNET_PeerIdentity))) || (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (lsocks[i], IPPROTO_TCP, TCP_STEALTH_INTEGRITY_LEN, &len, sizeof (len))) ) { /* TCP STEALTH not supported by kernel */ GNUNET_assert (0 == i); GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("TCP_STEALTH not supported on this platform.\n")); goto die; } } } #else GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("TCP_STEALTH not supported on this platform.\n")); goto die; #endif } if ( (NULL != service) && (GNUNET_SYSERR != (ret_s = GNUNET_SERVICE_get_server_addresses ("transport-tcp", env->cfg, &addrs, &addrlens)))) { for (ret = ret_s-1; ret >= 0; ret--) LOG (GNUNET_ERROR_TYPE_INFO, "Binding to address `%s'\n", GNUNET_a2s (addrs[ret], addrlens[ret])); plugin->nat = GNUNET_NAT_register (env->cfg, GNUNET_YES, aport, (unsigned int) ret_s, (const struct sockaddr **) addrs, addrlens, &tcp_nat_port_map_callback, &try_connection_reversal, plugin, NULL); for (ret = ret_s -1; ret >= 0; ret--) GNUNET_free (addrs[ret]); GNUNET_free_non_null (addrs); GNUNET_free_non_null (addrlens); } else { plugin->nat = GNUNET_NAT_register (plugin->env->cfg, GNUNET_YES, 0, 0, NULL, NULL, NULL, &try_connection_reversal, plugin, NULL); } api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions); api->cls = plugin; api->send = &tcp_plugin_send; api->get_session = &tcp_plugin_get_session; api->disconnect_session = &tcp_plugin_disconnect_session; api->query_keepalive_factor = &tcp_plugin_query_keepalive_factor; api->disconnect_peer = &tcp_plugin_disconnect; api->address_pretty_printer = &tcp_plugin_address_pretty_printer; api->check_address = &tcp_plugin_check_address; api->address_to_string = &tcp_plugin_address_to_string; api->string_to_address = &tcp_plugin_string_to_address; api->get_network = &tcp_plugin_get_network; api->get_network_for_address = &tcp_plugin_get_network_for_address; api->update_session_timeout = &tcp_plugin_update_session_timeout; api->update_inbound_delay = &tcp_plugin_update_inbound_delay; api->setup_monitor = &tcp_plugin_setup_monitor; plugin->service = service; if (NULL != service) { plugin->server = GNUNET_SERVICE_get_server (service); } else { if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_time (env->cfg, "transport-tcp", "TIMEOUT", &idle_timeout)) { GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR, "transport-tcp", "TIMEOUT"); goto die; } plugin->server = GNUNET_SERVER_create_with_sockets (NULL, plugin, NULL, idle_timeout, GNUNET_YES); } plugin->handlers = GNUNET_malloc (sizeof (my_handlers)); GNUNET_memcpy (plugin->handlers, my_handlers, sizeof(my_handlers)); for (i = 0;i < sizeof(my_handlers) / sizeof(struct GNUNET_SERVER_MessageHandler);i++) plugin->handlers[i].callback_cls = plugin; GNUNET_SERVER_add_handlers (plugin->server, plugin->handlers); GNUNET_SERVER_connect_notify (plugin->server, &connect_notify, plugin); GNUNET_SERVER_disconnect_notify (plugin->server, &disconnect_notify, plugin); plugin->nat_wait_conns = GNUNET_CONTAINER_multipeermap_create (16, GNUNET_YES); if (0 != bport) LOG (GNUNET_ERROR_TYPE_INFO, _("TCP transport listening on port %llu\n"), bport); else LOG (GNUNET_ERROR_TYPE_INFO, _("TCP transport not listening on any port (client only)\n")); if ( (aport != bport) && (0 != bport) ) LOG (GNUNET_ERROR_TYPE_INFO, _("TCP transport advertises itself as being on port %llu\n"), aport); /* Initially set connections to 0 */ GNUNET_STATISTICS_set (plugin->env->stats, gettext_noop ("# TCP sessions active"), 0, GNUNET_NO); return api; die: if (NULL != plugin->nat) GNUNET_NAT_unregister (plugin->nat); GNUNET_CONTAINER_multipeermap_destroy (plugin->sessionmap); if (NULL != service) GNUNET_SERVICE_stop (service); GNUNET_free (plugin); GNUNET_free_non_null (api); return NULL; } /** * Exit point from the plugin. * * @param cls the `struct GNUNET_TRANSPORT_PluginFunctions` * @return NULL */ void * libgnunet_plugin_transport_tcp_done (void *cls) { struct GNUNET_TRANSPORT_PluginFunctions *api = cls; struct Plugin *plugin = api->cls; struct TCPProbeContext *tcp_probe; struct PrettyPrinterContext *cur; struct PrettyPrinterContext *next; if (NULL == plugin) { GNUNET_free(api); return NULL ; } LOG (GNUNET_ERROR_TYPE_DEBUG, "Shutting down TCP plugin\n"); /* Removing leftover sessions */ GNUNET_CONTAINER_multipeermap_iterate (plugin->sessionmap, &session_disconnect_it, plugin); /* Removing leftover NAT sessions */ GNUNET_CONTAINER_multipeermap_iterate (plugin->nat_wait_conns, &session_disconnect_it, plugin); for (cur = plugin->ppc_dll_head; NULL != cur; cur = next) { next = cur->next; GNUNET_CONTAINER_DLL_remove (plugin->ppc_dll_head, plugin->ppc_dll_tail, cur); GNUNET_RESOLVER_request_cancel (cur->resolver_handle); cur->asc (cur->asc_cls, NULL, GNUNET_OK); GNUNET_free (cur); } if (NULL != plugin->service) GNUNET_SERVICE_stop (plugin->service); else GNUNET_SERVER_destroy (plugin->server); GNUNET_free (plugin->handlers); if (NULL != plugin->nat) GNUNET_NAT_unregister (plugin->nat); while (NULL != (tcp_probe = plugin->probe_head)) { GNUNET_CONTAINER_DLL_remove (plugin->probe_head, plugin->probe_tail, tcp_probe); GNUNET_CONNECTION_destroy (tcp_probe->sock); GNUNET_free (tcp_probe); } GNUNET_CONTAINER_multipeermap_destroy (plugin->nat_wait_conns); GNUNET_CONTAINER_multipeermap_destroy (plugin->sessionmap); GNUNET_break (0 == plugin->cur_connections); GNUNET_free (plugin); GNUNET_free (api); return NULL; } /* end of plugin_transport_tcp.c */