2 This file is part of GNUnet
3 (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Christian Grothoff (and other contributing authors)
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6 it under the terms of the GNU General Public License as published
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13 General Public License for more details.
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17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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21 * @file transport/plugin_transport_tcp.c
22 * @brief Implementation of the TCP transport service
23 * @author Christian Grothoff
26 #include "gnunet_hello_lib.h"
27 #include "gnunet_connection_lib.h"
28 #include "gnunet_container_lib.h"
29 #include "gnunet_os_lib.h"
30 #include "gnunet_protocols.h"
31 #include "gnunet_resolver_service.h"
32 #include "gnunet_server_lib.h"
33 #include "gnunet_service_lib.h"
34 #include "gnunet_signatures.h"
35 #include "gnunet_statistics_service.h"
36 #include "gnunet_transport_service.h"
37 #include "plugin_transport.h"
38 #include "transport.h"
40 #define DEBUG_TCP GNUNET_YES
43 * How long until we give up on transmitting the welcome message?
45 #define HOSTNAME_RESOLVE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
49 * Initial handshake message for a session.
54 * Type is GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME.
56 struct GNUNET_MessageHeader header;
59 * Identity of the node connecting (TCP client)
61 struct GNUNET_PeerIdentity clientIdentity;
67 * Encapsulation of all of the state of the plugin.
73 * Information kept for each message that is yet to
80 * This is a doubly-linked list.
82 struct PendingMessage *next;
85 * This is a doubly-linked list.
87 struct PendingMessage *prev;
95 * Continuation function to call once the message
96 * has been sent. Can be NULL if there is no
97 * continuation to call.
99 GNUNET_TRANSPORT_TransmitContinuation transmit_cont;
102 * Closure for transmit_cont.
104 void *transmit_cont_cls;
107 * Timeout value for the pending message.
109 struct GNUNET_TIME_Absolute timeout;
112 * So that the gnunet-service-transport can group messages together,
113 * these pending messages need to accept a message buffer and size
114 * instead of just a GNUNET_MessageHeader.
122 * Session handle for TCP connections.
128 * Stored in a linked list.
130 struct Session *next;
133 * Pointer to the global plugin struct.
135 struct Plugin *plugin;
138 * The client (used to identify this connection)
140 struct GNUNET_SERVER_Client *client;
143 * Messages currently pending for transmission
144 * to this peer, if any.
146 struct PendingMessage *pending_messages_head;
149 * Messages currently pending for transmission
150 * to this peer, if any.
152 struct PendingMessage *pending_messages_tail;
155 * Handle for pending transmission request.
157 struct GNUNET_CONNECTION_TransmitHandle *transmit_handle;
160 * To whom are we talking to (set to our identity
161 * if we are still waiting for the welcome message)
163 struct GNUNET_PeerIdentity target;
166 * ID of task used to delay receiving more to throttle sender.
168 GNUNET_SCHEDULER_TaskIdentifier receive_delay_task;
171 * Address of the other peer (either based on our 'connect'
172 * call or on our 'accept' call).
177 * Last activity on this connection. Used to select preferred
180 struct GNUNET_TIME_Absolute last_activity;
183 * Length of connect_addr.
188 * Are we still expecting the welcome message? (GNUNET_YES/GNUNET_NO)
190 int expecting_welcome;
193 * Was this a connection that was inbound (we accepted)? (GNUNET_YES/GNUNET_NO)
201 * Encapsulation of all of the state of the plugin.
208 struct GNUNET_TRANSPORT_PluginEnvironment *env;
213 struct GNUNET_CONNECTION_Handle *lsock;
216 * List of open TCP sessions.
218 struct Session *sessions;
221 * Handle for the statistics service.
223 struct GNUNET_STATISTICS_Handle *statistics;
226 * Handle to the network service.
228 struct GNUNET_SERVICE_Context *service;
231 * Handle to the server for this service.
233 struct GNUNET_SERVER_Handle *server;
236 * Copy of the handler array where the closures are
237 * set to this struct's instance.
239 struct GNUNET_SERVER_MessageHandler *handlers;
242 * Handle for request of hostname resolution, non-NULL if pending.
244 struct GNUNET_RESOLVER_RequestHandle *hostname_dns;
247 * ID of task used to update our addresses when one expires.
249 GNUNET_SCHEDULER_TaskIdentifier address_update_task;
252 * Port that we are actually listening on.
257 * Port that the user said we would have visible to the
266 * Find the session handle for the given client.
268 * @return NULL if no matching session exists
270 static struct Session *
271 find_session_by_client (struct Plugin *plugin,
272 const struct GNUNET_SERVER_Client *client)
276 ret = plugin->sessions;
277 while ((ret != NULL) && (client != ret->client))
284 * Create a new session. Also queues a welcome message.
287 * @param target peer to connect to
288 * @param client client to use
289 * @return new session object
291 static struct Session *
292 create_session (struct Plugin *plugin,
293 const struct GNUNET_PeerIdentity *target,
294 struct GNUNET_SERVER_Client *client)
297 struct PendingMessage *pm;
298 struct WelcomeMessage welcome;
300 GNUNET_assert (client != NULL);
301 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
303 "Creating new session for peer `%4s'\n",
304 GNUNET_i2s (target));
305 ret = GNUNET_malloc (sizeof (struct Session));
306 ret->last_activity = GNUNET_TIME_absolute_get ();
307 ret->plugin = plugin;
308 ret->next = plugin->sessions;
309 plugin->sessions = ret;
310 ret->client = client;
311 ret->target = *target;
312 ret->expecting_welcome = GNUNET_YES;
313 pm = GNUNET_malloc (sizeof (struct PendingMessage) + sizeof (struct WelcomeMessage));
314 pm->msg = (const char*) &pm[1];
315 pm->message_size = sizeof (struct WelcomeMessage);
316 welcome.header.size = htons (sizeof (struct WelcomeMessage));
317 welcome.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME);
318 welcome.clientIdentity = *plugin->env->my_identity;
319 memcpy (&pm[1], &welcome, sizeof (welcome));
320 pm->timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
321 GNUNET_STATISTICS_update (plugin->env->stats,
322 gettext_noop ("# bytes currently in TCP buffers"),
325 GNUNET_CONTAINER_DLL_insert (ret->pending_messages_head,
326 ret->pending_messages_tail,
328 GNUNET_STATISTICS_update (plugin->env->stats,
329 gettext_noop ("# TCP sessions active"),
337 * If we have pending messages, ask the server to
338 * transmit them (schedule the respective tasks, etc.)
340 * @param session for which session should we do this
342 static void process_pending_messages (struct Session *session);
346 * Function called to notify a client about the socket
347 * being ready to queue more data. "buf" will be
348 * NULL and "size" zero if the socket was closed for
349 * writing in the meantime.
352 * @param size number of bytes available in buf
353 * @param buf where the callee should write the message
354 * @return number of bytes written to buf
357 do_transmit (void *cls, size_t size, void *buf)
359 struct Session *session = cls;
360 struct GNUNET_PeerIdentity pid;
361 struct Plugin *plugin;
362 struct PendingMessage *pos;
363 struct PendingMessage *hd;
364 struct PendingMessage *tl;
365 struct GNUNET_TIME_Absolute now;
369 session->transmit_handle = NULL;
370 plugin = session->plugin;
374 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
376 "Timeout trying to transmit to peer `%4s', discarding message queue.\n",
377 GNUNET_i2s (&session->target));
379 /* timeout; cancel all messages that have already expired */
383 now = GNUNET_TIME_absolute_get ();
384 while ( (NULL != (pos = session->pending_messages_head)) &&
385 (pos->timeout.value <= now.value) )
387 GNUNET_CONTAINER_DLL_remove (session->pending_messages_head,
388 session->pending_messages_tail,
391 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
393 "Failed to transmit %u byte message to `%4s'.\n",
395 GNUNET_i2s (&session->target));
397 ret += pos->message_size;
398 GNUNET_CONTAINER_DLL_insert_after (hd, tl, tl, pos);
400 /* do this call before callbacks (so that if callbacks destroy
401 session, they have a chance to cancel actions done by this
403 process_pending_messages (session);
404 pid = session->target;
405 /* no do callbacks and do not use session again since
406 the callbacks may abort the session */
407 while (NULL != (pos = hd))
409 GNUNET_CONTAINER_DLL_remove (hd, tl, pos);
410 if (pos->transmit_cont != NULL)
411 pos->transmit_cont (pos->transmit_cont_cls,
412 &pid, GNUNET_SYSERR);
415 GNUNET_STATISTICS_update (plugin->env->stats,
416 gettext_noop ("# bytes currently in TCP buffers"),
419 GNUNET_STATISTICS_update (plugin->env->stats,
420 gettext_noop ("# bytes discarded by TCP (timeout)"),
425 /* copy all pending messages that would fit */
430 while (NULL != (pos = session->pending_messages_head))
432 if (ret + pos->message_size > size)
434 GNUNET_CONTAINER_DLL_remove (session->pending_messages_head,
435 session->pending_messages_tail,
437 GNUNET_assert (size >= pos->message_size);
438 memcpy (cbuf, pos->msg, pos->message_size);
439 cbuf += pos->message_size;
440 ret += pos->message_size;
441 size -= pos->message_size;
442 GNUNET_CONTAINER_DLL_insert_after (hd, tl, tl, pos);
444 /* schedule 'continuation' before callbacks so that callbacks that
445 cancel everything don't cause us to use a session that no longer
447 process_pending_messages (session);
448 session->last_activity = GNUNET_TIME_absolute_get ();
449 pid = session->target;
450 /* we'll now call callbacks that may cancel the session; hence
451 we should not use 'session' after this point */
452 while (NULL != (pos = hd))
454 GNUNET_CONTAINER_DLL_remove (hd, tl, pos);
455 if (pos->transmit_cont != NULL)
456 pos->transmit_cont (pos->transmit_cont_cls,
460 GNUNET_assert (hd == NULL);
461 GNUNET_assert (tl == NULL);
463 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
464 "tcp", "Transmitting %u bytes\n", ret);
466 GNUNET_STATISTICS_update (plugin->env->stats,
467 gettext_noop ("# bytes currently in TCP buffers"),
470 GNUNET_STATISTICS_update (plugin->env->stats,
471 gettext_noop ("# bytes transmitted via TCP"),
479 * If we have pending messages, ask the server to
480 * transmit them (schedule the respective tasks, etc.)
482 * @param session for which session should we do this
485 process_pending_messages (struct Session *session)
487 struct PendingMessage *pm;
489 GNUNET_assert (session->client != NULL);
490 if (session->transmit_handle != NULL)
492 if (NULL == (pm = session->pending_messages_head))
494 session->transmit_handle
495 = GNUNET_SERVER_notify_transmit_ready (session->client,
497 GNUNET_TIME_absolute_get_remaining
499 &do_transmit, session);
504 * Functions with this signature are called whenever we need
505 * to close a session due to a disconnect or failure to
506 * establish a connection.
508 * @param session session to close down
511 disconnect_session (struct Session *session)
513 struct Session *prev;
515 struct PendingMessage *pm;
518 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
520 "Disconnecting from `%4s' at %s (session %p).\n",
521 GNUNET_i2s (&session->target),
522 (session->connect_addr != NULL) ?
523 GNUNET_a2s (session->connect_addr,
524 session->connect_alen) : "*", session);
526 /* remove from session list */
528 pos = session->plugin->sessions;
529 while (pos != session)
535 session->plugin->sessions = session->next;
537 prev->next = session->next;
539 if (session->transmit_handle != NULL)
541 GNUNET_CONNECTION_notify_transmit_ready_cancel
542 (session->transmit_handle);
543 session->transmit_handle = NULL;
545 while (NULL != (pm = session->pending_messages_head))
548 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
550 pm->transmit_cont != NULL
551 ? "Could not deliver message to `%4s'.\n"
553 "Could not deliver message to `%4s', notifying.\n",
554 GNUNET_i2s (&session->target));
556 GNUNET_STATISTICS_update (session->plugin->env->stats,
557 gettext_noop ("# bytes currently in TCP buffers"),
558 - (int64_t) pm->message_size,
560 GNUNET_STATISTICS_update (session->plugin->env->stats,
561 gettext_noop ("# bytes discarded by TCP (disconnect)"),
564 GNUNET_CONTAINER_DLL_remove (session->pending_messages_head,
565 session->pending_messages_tail,
567 if (NULL != pm->transmit_cont)
568 pm->transmit_cont (pm->transmit_cont_cls,
569 &session->target, GNUNET_SYSERR);
572 GNUNET_break (session->client != NULL);
573 if (session->receive_delay_task != GNUNET_SCHEDULER_NO_TASK)
575 GNUNET_SCHEDULER_cancel (session->plugin->env->sched,
576 session->receive_delay_task);
577 GNUNET_SERVER_receive_done (session->client,
580 GNUNET_SERVER_client_drop (session->client);
581 GNUNET_STATISTICS_update (session->plugin->env->stats,
582 gettext_noop ("# TCP sessions active"),
585 GNUNET_free_non_null (session->connect_addr);
586 GNUNET_free (session);
591 * Given two otherwise equivalent sessions, pick the better one.
593 * @param s1 one session (also default)
594 * @param s2 other session
595 * @return "better" session (more active)
597 static struct Session *
598 select_better_session (struct Session *s1,
605 if ( (s1->expecting_welcome == GNUNET_NO) &&
606 (s2->expecting_welcome == GNUNET_YES) )
608 if ( (s1->expecting_welcome == GNUNET_YES) &&
609 (s2->expecting_welcome == GNUNET_NO) )
611 if (s1->last_activity.value < s2->last_activity.value)
613 if (s1->last_activity.value > s2->last_activity.value)
615 if ( (GNUNET_YES == s1->inbound) &&
616 (GNUNET_NO == s2->inbound) )
618 if ( (GNUNET_NO == s1->inbound) &&
619 (GNUNET_YES == s2->inbound) )
626 * Function that can be used by the transport service to transmit
627 * a message using the plugin. Note that in the case of a
628 * peer disconnecting, the continuation MUST be called
629 * prior to the disconnect notification itself. This function
630 * will be called with this peer's HELLO message to initiate
631 * a fresh connection to another peer.
634 * @param target who should receive this message
635 * @param msg the message to transmit
636 * @param msgbuf_size number of bytes in 'msg'
637 * @param priority how important is the message (most plugins will
638 * ignore message priority and just FIFO)
639 * @param timeout how long to wait at most for the transmission (does not
640 * require plugins to discard the message after the timeout,
641 * just advisory for the desired delay; most plugins will ignore
643 * @param session which session must be used (or NULL for "any")
644 * @param addr the address to use (can be NULL if the plugin
645 * is "on its own" (i.e. re-use existing TCP connection))
646 * @param addrlen length of the address in bytes
647 * @param force_address GNUNET_YES if the plugin MUST use the given address,
648 * GNUNET_NO means the plugin may use any other address and
649 * GNUNET_SYSERR means that only reliable existing
650 * bi-directional connections should be used (regardless
652 * @param cont continuation to call once the message has
653 * been transmitted (or if the transport is ready
654 * for the next transmission call; or if the
655 * peer disconnected...); can be NULL
656 * @param cont_cls closure for cont
657 * @return number of bytes used (on the physical network, with overheads);
658 * -1 on hard errors (i.e. address invalid); 0 is a legal value
659 * and does NOT mean that the message was not transmitted (DV)
662 tcp_plugin_send (void *cls,
663 const struct GNUNET_PeerIdentity *target,
667 struct GNUNET_TIME_Relative timeout,
668 struct Session *session,
672 GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls)
674 struct Plugin *plugin = cls;
675 struct Session *cand_session;
676 struct Session *next;
677 struct PendingMessage *pm;
678 struct GNUNET_CONNECTION_Handle *sa;
681 GNUNET_STATISTICS_update (plugin->env->stats,
682 gettext_noop ("# bytes TCP was asked to transmit"),
685 /* FIXME: we could do this a cheaper with a hash table
686 where we could restrict the iteration to entries that match
687 the target peer... */
691 next = plugin->sessions;
692 while (NULL != (session = next))
694 next = session->next;
695 GNUNET_assert (session->client != NULL);
696 if (0 != memcmp (target,
698 sizeof (struct GNUNET_PeerIdentity)))
700 if ( ( (GNUNET_SYSERR == force_address) &&
701 (session->expecting_welcome == GNUNET_NO) ) ||
702 (GNUNET_NO == force_address) )
704 cand_session = select_better_session (cand_session,
708 if (GNUNET_SYSERR == force_address)
710 GNUNET_break (GNUNET_YES == force_address);
716 if (session->inbound == GNUNET_YES)
718 if (addrlen != session->connect_alen)
720 if (0 != memcmp (session->connect_addr,
724 cand_session = select_better_session (cand_session,
727 session = cand_session;
729 if ( (session == NULL) &&
733 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
735 "Asked to transmit to `%4s' without address and I have no existing connection (failing).\n",
736 GNUNET_i2s (target));
738 GNUNET_STATISTICS_update (plugin->env->stats,
739 gettext_noop ("# bytes discarded by TCP (no address and no connection)"),
746 if (sizeof (struct sockaddr_in) == addrlen)
750 else if (sizeof (struct sockaddr_in6) == addrlen)
759 sa = GNUNET_CONNECTION_create_from_sockaddr (plugin->env->sched,
761 GNUNET_SERVER_MAX_MESSAGE_SIZE);
765 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
767 "Failed to create connection to `%4s' at `%s'\n",
769 GNUNET_a2s (addr, addrlen));
771 GNUNET_STATISTICS_update (plugin->env->stats,
772 gettext_noop ("# bytes discarded by TCP (failed to connect)"),
778 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
780 "Asked to transmit to `%4s', creating fresh session using address `%s'.\n",
782 GNUNET_a2s (addr, addrlen));
784 session = create_session (plugin,
786 GNUNET_SERVER_connect_socket (plugin->server,
788 session->connect_addr = GNUNET_malloc (addrlen);
789 memcpy (session->connect_addr,
792 session->connect_alen = addrlen;
794 GNUNET_assert (session != NULL);
795 GNUNET_assert (session->client != NULL);
796 GNUNET_STATISTICS_update (plugin->env->stats,
797 gettext_noop ("# bytes currently in TCP buffers"),
800 /* create new message entry */
801 pm = GNUNET_malloc (sizeof (struct PendingMessage) + msgbuf_size);
802 pm->msg = (const char*) &pm[1];
803 memcpy (&pm[1], msg, msgbuf_size);
804 pm->message_size = msgbuf_size;
805 pm->timeout = GNUNET_TIME_relative_to_absolute (timeout);
806 pm->transmit_cont = cont;
807 pm->transmit_cont_cls = cont_cls;
809 /* append pm to pending_messages list */
810 GNUNET_CONTAINER_DLL_insert_after (session->pending_messages_head,
811 session->pending_messages_tail,
812 session->pending_messages_tail,
815 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
817 "Asked to transmit %u bytes to `%s', added message to list.\n",
819 GNUNET_i2s (target));
821 process_pending_messages (session);
827 * Function that can be called to force a disconnect from the
828 * specified neighbour. This should also cancel all previously
829 * scheduled transmissions. Obviously the transmission may have been
830 * partially completed already, which is OK. The plugin is supposed
831 * to close the connection (if applicable) and no longer call the
832 * transmit continuation(s).
834 * Finally, plugin MUST NOT call the services's receive function to
835 * notify the service that the connection to the specified target was
836 * closed after a getting this call.
839 * @param target peer for which the last transmission is
843 tcp_plugin_disconnect (void *cls,
844 const struct GNUNET_PeerIdentity *target)
846 struct Plugin *plugin = cls;
847 struct Session *session;
848 struct Session *next;
849 struct PendingMessage *pm;
852 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
854 "Asked to cancel session with `%4s'\n",
855 GNUNET_i2s (target));
857 next = plugin->sessions;
858 while (NULL != (session = next))
860 next = session->next;
861 if (0 != memcmp (target,
863 sizeof (struct GNUNET_PeerIdentity)))
865 pm = session->pending_messages_head;
868 pm->transmit_cont = NULL;
869 pm->transmit_cont_cls = NULL;
872 disconnect_session (session);
878 * Context for address to string conversion.
880 struct PrettyPrinterContext
883 * Function to call with the result.
885 GNUNET_TRANSPORT_AddressStringCallback asc;
893 * Port to add after the IP address.
900 * Append our port and forward the result.
902 * @param cls the 'struct PrettyPrinterContext*'
903 * @param hostname hostname part of the address
906 append_port (void *cls, const char *hostname)
908 struct PrettyPrinterContext *ppc = cls;
911 if (hostname == NULL)
913 ppc->asc (ppc->asc_cls, NULL);
917 GNUNET_asprintf (&ret, "%s:%d", hostname, ppc->port);
918 ppc->asc (ppc->asc_cls, ret);
924 * Convert the transports address to a nice, human-readable
928 * @param type name of the transport that generated the address
929 * @param addr one of the addresses of the host, NULL for the last address
930 * the specific address format depends on the transport
931 * @param addrlen length of the address
932 * @param numeric should (IP) addresses be displayed in numeric form?
933 * @param timeout after how long should we give up?
934 * @param asc function to call on each string
935 * @param asc_cls closure for asc
938 tcp_plugin_address_pretty_printer (void *cls,
943 struct GNUNET_TIME_Relative timeout,
944 GNUNET_TRANSPORT_AddressStringCallback asc,
947 struct Plugin *plugin = cls;
948 const struct sockaddr_in *v4;
949 const struct sockaddr_in6 *v6;
950 struct PrettyPrinterContext *ppc;
952 if ((addrlen != sizeof (struct sockaddr_in)) &&
953 (addrlen != sizeof (struct sockaddr_in6)))
955 /* invalid address */
960 ppc = GNUNET_malloc (sizeof (struct PrettyPrinterContext));
962 ppc->asc_cls = asc_cls;
963 if (addrlen == sizeof (struct sockaddr_in))
965 v4 = (const struct sockaddr_in *) addr;
966 ppc->port = ntohs (v4->sin_port);
970 v6 = (const struct sockaddr_in6 *) addr;
971 ppc->port = ntohs (v6->sin6_port);
974 GNUNET_RESOLVER_hostname_get (plugin->env->sched,
978 !numeric, timeout, &append_port, ppc);
983 * Check if the given port is plausible (must be either
984 * our listen port or our advertised port). If it is
985 * neither, we return one of these two ports at random.
987 * @param plugin global variables
988 * @param in_port port number to check
989 * @return either in_port or a more plausible port
992 check_port (struct Plugin *plugin, uint16_t in_port)
994 if ((in_port == plugin->adv_port) || (in_port == plugin->open_port))
996 return (GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
998 ? plugin->open_port : plugin->adv_port;
1003 * Another peer has suggested an address for this peer and transport
1004 * plugin. Check that this could be a valid address.
1006 * @param cls closure, our 'struct Plugin*'
1007 * @param addr pointer to the address
1008 * @param addrlen length of addr
1009 * @return GNUNET_OK if this is a plausible address for this peer
1013 tcp_plugin_check_address (void *cls, void *addr, size_t addrlen)
1015 struct Plugin *plugin = cls;
1016 char buf[sizeof (struct sockaddr_in6)];
1017 struct sockaddr_in *v4;
1018 struct sockaddr_in6 *v6;
1020 if ((addrlen != sizeof (struct sockaddr_in)) &&
1021 (addrlen != sizeof (struct sockaddr_in6)))
1023 GNUNET_break_op (0);
1024 return GNUNET_SYSERR;
1026 memcpy (buf, addr, sizeof (struct sockaddr_in6));
1027 if (addrlen == sizeof (struct sockaddr_in))
1029 v4 = (struct sockaddr_in *) buf;
1030 v4->sin_port = htons (check_port (plugin, ntohs (v4->sin_port)));
1034 v6 = (struct sockaddr_in6 *) buf;
1035 v6->sin6_port = htons (check_port (plugin, ntohs (v6->sin6_port)));
1038 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1040 "Informing transport service about my address `%s'.\n",
1041 GNUNET_a2s (addr, addrlen));
1048 * We've received a welcome from this peer via TCP. Possibly create a
1049 * fresh client record and send back our welcome.
1051 * @param cls closure
1052 * @param client identification of the client
1053 * @param message the actual message
1056 handle_tcp_welcome (void *cls,
1057 struct GNUNET_SERVER_Client *client,
1058 const struct GNUNET_MessageHeader *message)
1060 struct Plugin *plugin = cls;
1061 const struct WelcomeMessage *wm = (const struct WelcomeMessage *) message;
1062 struct Session *session;
1067 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1069 "Received %s message from a `%4s/%p'.\n",
1071 GNUNET_i2s (&wm->clientIdentity), client);
1073 GNUNET_STATISTICS_update (plugin->env->stats,
1074 gettext_noop ("# TCP WELCOME messages received"),
1077 session = find_session_by_client (plugin, client);
1078 if (session == NULL)
1080 GNUNET_SERVER_client_keep (client);
1081 session = create_session (plugin,
1082 &wm->clientIdentity, client);
1083 session->inbound = GNUNET_YES;
1085 GNUNET_SERVER_client_get_address (client, &vaddr, &alen))
1088 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1090 "Found address `%s' for incoming connection %p\n",
1091 GNUNET_a2s (vaddr, alen),
1094 session->connect_addr = vaddr;
1095 session->connect_alen = alen;
1100 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1102 "Did not obtain TCP socket address for incoming connection\n");
1106 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1108 "Creating new session %p for connection %p\n",
1111 process_pending_messages (session);
1113 if (session->expecting_welcome != GNUNET_YES)
1115 GNUNET_break_op (0);
1116 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1119 session->last_activity = GNUNET_TIME_absolute_get ();
1120 session->expecting_welcome = GNUNET_NO;
1121 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1126 * Task to signal the server that we can continue
1127 * receiving from the TCP client now.
1129 * @param cls the 'struct Session*'
1130 * @param tc task context (unused)
1133 delayed_done (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1135 struct Session *session = cls;
1136 struct GNUNET_TIME_Relative delay;
1138 session->receive_delay_task = GNUNET_SCHEDULER_NO_TASK;
1139 delay = session->plugin->env->receive (session->plugin->env->cls,
1144 if (delay.value == 0)
1145 GNUNET_SERVER_receive_done (session->client, GNUNET_OK);
1147 session->receive_delay_task =
1148 GNUNET_SCHEDULER_add_delayed (session->plugin->env->sched,
1149 delay, &delayed_done, session);
1154 * We've received data for this peer via TCP. Unbox,
1155 * compute latency and forward.
1157 * @param cls closure
1158 * @param client identification of the client
1159 * @param message the actual message
1162 handle_tcp_data (void *cls,
1163 struct GNUNET_SERVER_Client *client,
1164 const struct GNUNET_MessageHeader *message)
1166 struct Plugin *plugin = cls;
1167 struct Session *session;
1168 struct GNUNET_TIME_Relative delay;
1170 if (GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME == ntohs(message->type))
1172 /* We don't want to propagate WELCOME messages up! */
1173 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1176 session = find_session_by_client (plugin, client);
1177 if ( (NULL == session) || (GNUNET_NO != session->expecting_welcome))
1179 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1182 session->last_activity = GNUNET_TIME_absolute_get ();
1184 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1186 "Passing %u bytes of type %u from `%4s' to transport service.\n",
1187 (unsigned int) ntohs (message->size),
1188 (unsigned int) ntohs (message->type),
1189 GNUNET_i2s (&session->target));
1191 GNUNET_STATISTICS_update (plugin->env->stats,
1192 gettext_noop ("# bytes received via TCP"),
1193 ntohs (message->size),
1195 delay = plugin->env->receive (plugin->env->cls, &session->target, message, 1,
1197 (GNUNET_YES == session->inbound) ? NULL : session->connect_addr,
1198 (GNUNET_YES == session->inbound) ? 0 : session->connect_alen);
1199 if (delay.value == 0)
1200 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1202 session->receive_delay_task =
1203 GNUNET_SCHEDULER_add_delayed (session->plugin->env->sched,
1204 delay, &delayed_done, session);
1209 * Handlers for the various TCP messages.
1211 static struct GNUNET_SERVER_MessageHandler my_handlers[] = {
1212 {&handle_tcp_welcome, NULL, GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME,
1213 sizeof (struct WelcomeMessage)},
1214 {&handle_tcp_data, NULL, GNUNET_MESSAGE_TYPE_ALL, 0},
1220 * Functions with this signature are called whenever a peer
1221 * is disconnected on the network level.
1223 * @param cls closure
1224 * @param client identification of the client
1227 disconnect_notify (void *cls, struct GNUNET_SERVER_Client *client)
1229 struct Plugin *plugin = cls;
1230 struct Session *session;
1234 session = find_session_by_client (plugin, client);
1235 if (session == NULL)
1236 return; /* unknown, nothing to do */
1238 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1240 "Destroying session of `%4s' with %s (%p) due to network-level disconnect.\n",
1241 GNUNET_i2s (&session->target),
1242 (session->connect_addr != NULL) ?
1243 GNUNET_a2s (session->connect_addr,
1244 session->connect_alen) : "*", client);
1246 disconnect_session (session);
1251 * Add the IP of our network interface to the list of
1252 * our external IP addresses.
1255 process_interfaces (void *cls,
1258 const struct sockaddr *addr, socklen_t addrlen)
1260 struct Plugin *plugin = cls;
1262 struct sockaddr_in *v4;
1263 struct sockaddr_in6 *v6;
1265 af = addr->sa_family;
1268 v4 = (struct sockaddr_in *) addr;
1269 v4->sin_port = htons (plugin->adv_port);
1273 GNUNET_assert (af == AF_INET6);
1274 v6 = (struct sockaddr_in6 *) addr;
1275 v6->sin6_port = htons (plugin->adv_port);
1277 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO |
1278 GNUNET_ERROR_TYPE_BULK,
1279 "tcp", _("Found address `%s' (%s)\n"),
1280 GNUNET_a2s (addr, addrlen), name);
1281 plugin->env->notify_address (plugin->env->cls,
1283 addr, addrlen, GNUNET_TIME_UNIT_FOREVER_REL);
1289 * Function called by the resolver for each address obtained from DNS
1290 * for our own hostname. Add the addresses to the list of our
1291 * external IP addresses.
1293 * @param cls closure
1294 * @param addr one of the addresses of the host, NULL for the last address
1295 * @param addrlen length of the address
1298 process_hostname_ips (void *cls,
1299 const struct sockaddr *addr, socklen_t addrlen)
1301 struct Plugin *plugin = cls;
1305 plugin->hostname_dns = NULL;
1308 process_interfaces (plugin, "<hostname>", GNUNET_YES, addr, addrlen);
1313 * Entry point for the plugin.
1316 libgnunet_plugin_transport_tcp_init (void *cls)
1318 struct GNUNET_TRANSPORT_PluginEnvironment *env = cls;
1319 struct GNUNET_TRANSPORT_PluginFunctions *api;
1320 struct Plugin *plugin;
1321 struct GNUNET_SERVICE_Context *service;
1322 unsigned long long aport;
1323 unsigned long long bport;
1326 service = GNUNET_SERVICE_start ("transport-tcp", env->sched, env->cfg);
1327 if (service == NULL)
1329 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING,
1332 ("Failed to start service for `%s' transport plugin.\n"),
1338 GNUNET_CONFIGURATION_get_value_number (env->cfg,
1344 GNUNET_CONFIGURATION_get_value_number (env->cfg,
1347 &aport)) && (aport > 65535)))
1349 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
1352 ("Require valid port number for service `%s' in configuration!\n"),
1354 GNUNET_SERVICE_stop (service);
1359 plugin = GNUNET_malloc (sizeof (struct Plugin));
1360 plugin->open_port = bport;
1361 plugin->adv_port = aport;
1363 plugin->lsock = NULL;
1364 plugin->statistics = NULL;
1365 api = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_PluginFunctions));
1367 api->send = &tcp_plugin_send;
1368 api->disconnect = &tcp_plugin_disconnect;
1369 api->address_pretty_printer = &tcp_plugin_address_pretty_printer;
1370 api->check_address = &tcp_plugin_check_address;
1371 plugin->service = service;
1372 plugin->server = GNUNET_SERVICE_get_server (service);
1373 plugin->handlers = GNUNET_malloc (sizeof (my_handlers));
1374 memcpy (plugin->handlers, my_handlers, sizeof (my_handlers));
1377 sizeof (my_handlers) / sizeof (struct GNUNET_SERVER_MessageHandler);
1379 plugin->handlers[i].callback_cls = plugin;
1380 GNUNET_SERVER_add_handlers (plugin->server, plugin->handlers);
1382 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
1383 "tcp", _("TCP transport listening on port %llu\n"), bport);
1385 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
1387 _("TCP transport advertises itself as being on port %llu\n"),
1389 GNUNET_SERVER_disconnect_notify (plugin->server,
1392 /* FIXME: do the two calls below periodically again and
1393 not just once (since the info we get might change...) */
1394 GNUNET_OS_network_interfaces_list (&process_interfaces, plugin);
1395 plugin->hostname_dns = GNUNET_RESOLVER_hostname_resolve (env->sched,
1398 HOSTNAME_RESOLVE_TIMEOUT,
1399 &process_hostname_ips,
1406 * Exit point from the plugin.
1409 libgnunet_plugin_transport_tcp_done (void *cls)
1411 struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
1412 struct Plugin *plugin = api->cls;
1413 struct Session *session;
1415 while (NULL != (session = plugin->sessions))
1416 disconnect_session (session);
1417 if (NULL != plugin->hostname_dns)
1419 GNUNET_RESOLVER_request_cancel (plugin->hostname_dns);
1420 plugin->hostname_dns = NULL;
1422 GNUNET_SERVICE_stop (plugin->service);
1423 GNUNET_free (plugin->handlers);
1424 GNUNET_free (plugin);
1429 /* end of plugin_transport_tcp.c */