2 This file is part of GNUnet
3 (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 2, or (at your
8 option) any later version.
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11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file transport/plugin_transport_tcp.c
23 * @brief Implementation of the TCP transport service
24 * @author Christian Grothoff
28 #include "gnunet_hello_lib.h"
29 #include "gnunet_connection_lib.h"
30 #include "gnunet_container_lib.h"
31 #include "gnunet_os_lib.h"
32 #include "gnunet_protocols.h"
33 #include "gnunet_resolver_service.h"
34 #include "gnunet_server_lib.h"
35 #include "gnunet_service_lib.h"
36 #include "gnunet_signatures.h"
37 #include "gnunet_statistics_service.h"
38 #include "gnunet_transport_service.h"
39 #include "plugin_transport.h"
40 #include "transport.h"
42 #define DEBUG_TCP GNUNET_YES
45 * How long until we give up on transmitting the welcome message?
47 #define HOSTNAME_RESOLVE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
51 * Initial handshake message for a session.
56 * Type is GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME.
58 struct GNUNET_MessageHeader header;
61 * Identity of the node connecting (TCP client)
63 struct GNUNET_PeerIdentity clientIdentity;
69 * Encapsulation of all of the state of the plugin.
75 * Information kept for each message that is yet to
82 * This is a doubly-linked list.
84 struct PendingMessage *next;
87 * This is a doubly-linked list.
89 struct PendingMessage *prev;
97 * Continuation function to call once the message
98 * has been sent. Can be NULL if there is no
99 * continuation to call.
101 GNUNET_TRANSPORT_TransmitContinuation transmit_cont;
104 * Closure for transmit_cont.
106 void *transmit_cont_cls;
109 * Timeout value for the pending message.
111 struct GNUNET_TIME_Absolute timeout;
114 * So that the gnunet-service-transport can group messages together,
115 * these pending messages need to accept a message buffer and size
116 * instead of just a GNUNET_MessageHeader.
124 * Session handle for TCP connections.
130 * Stored in a linked list.
132 struct Session *next;
135 * Pointer to the global plugin struct.
137 struct Plugin *plugin;
140 * The client (used to identify this connection)
142 struct GNUNET_SERVER_Client *client;
145 * Messages currently pending for transmission
146 * to this peer, if any.
148 struct PendingMessage *pending_messages_head;
151 * Messages currently pending for transmission
152 * to this peer, if any.
154 struct PendingMessage *pending_messages_tail;
157 * Handle for pending transmission request.
159 struct GNUNET_CONNECTION_TransmitHandle *transmit_handle;
162 * To whom are we talking to (set to our identity
163 * if we are still waiting for the welcome message)
165 struct GNUNET_PeerIdentity target;
168 * At what time did we reset last_received last?
170 struct GNUNET_TIME_Absolute last_quota_update;
173 * Address of the other peer (either based on our 'connect'
174 * call or on our 'accept' call).
179 * How many bytes have we received since the "last_quota_update"
182 uint64_t last_received;
185 * Number of bytes per ms that this peer is allowed
191 * Length of connect_addr.
196 * Are we still expecting the welcome message? (GNUNET_YES/GNUNET_NO)
197 * GNUNET_SYSERR is used to mark non-welcoming connections (HELLO
200 int expecting_welcome;
206 * Encapsulation of all of the state of the plugin.
213 struct GNUNET_TRANSPORT_PluginEnvironment *env;
218 struct GNUNET_CONNECTION_Handle *lsock;
221 * List of open TCP sessions.
223 struct Session *sessions;
226 * Handle for the statistics service.
228 struct GNUNET_STATISTICS_Handle *statistics;
231 * Handle to the network service.
233 struct GNUNET_SERVICE_Context *service;
236 * Handle to the server for this service.
238 struct GNUNET_SERVER_Handle *server;
241 * Copy of the handler array where the closures are
242 * set to this struct's instance.
244 struct GNUNET_SERVER_MessageHandler *handlers;
247 * Handle for request of hostname resolution, non-NULL if pending.
249 struct GNUNET_RESOLVER_RequestHandle *hostname_dns;
252 * ID of task used to update our addresses when one expires.
254 GNUNET_SCHEDULER_TaskIdentifier address_update_task;
257 * Port that we are actually listening on.
262 * Port that the user said we would have visible to the
271 * Find a session handle for the given peer.
272 * FIXME: using a hash map we could do this in O(1).
274 * @return NULL if no matching session exists
276 static struct Session *
277 find_session_by_target (struct Plugin *plugin,
278 const struct GNUNET_PeerIdentity *target)
282 ret = plugin->sessions;
283 while ( (ret != NULL) &&
284 ((GNUNET_SYSERR == ret->expecting_welcome) ||
285 (0 != memcmp (target,
286 &ret->target, sizeof (struct GNUNET_PeerIdentity)))))
293 * Find the session handle for the given client.
295 * @return NULL if no matching session exists
297 static struct Session *
298 find_session_by_client (struct Plugin *plugin,
299 const struct GNUNET_SERVER_Client *client)
303 ret = plugin->sessions;
304 while ((ret != NULL) && (client != ret->client))
311 * Create a new session. Also queues a welcome message.
314 * @param target peer to connect to
315 * @param client client to use
316 * @return new session object
318 static struct Session *
319 create_session (struct Plugin *plugin,
320 const struct GNUNET_PeerIdentity *target,
321 struct GNUNET_SERVER_Client *client)
324 struct PendingMessage *pm;
325 struct WelcomeMessage welcome;
327 ret = GNUNET_malloc (sizeof (struct Session));
328 ret->plugin = plugin;
329 ret->next = plugin->sessions;
330 plugin->sessions = ret;
331 ret->client = client;
332 ret->target = *target;
333 ret->last_quota_update = GNUNET_TIME_absolute_get ();
334 ret->quota_in = plugin->env->default_quota_in;
335 ret->expecting_welcome = GNUNET_YES;
336 pm = GNUNET_malloc (sizeof (struct PendingMessage) + sizeof (struct WelcomeMessage));
337 pm->msg = (const char*) &pm[1];
338 pm->message_size = sizeof (struct WelcomeMessage);
339 welcome.header.size = htons (sizeof (struct WelcomeMessage));
340 welcome.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME);
341 welcome.clientIdentity = *plugin->env->my_identity;
342 memcpy (&pm[1], &welcome, sizeof (welcome));
343 pm->timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
344 GNUNET_CONTAINER_DLL_insert (ret->pending_messages_head,
345 ret->pending_messages_tail,
352 * If we have pending messages, ask the server to
353 * transmit them (schedule the respective tasks, etc.)
355 * @param session for which session should we do this
357 static void process_pending_messages (struct Session *session);
361 * Function called to notify a client about the socket
362 * being ready to queue more data. "buf" will be
363 * NULL and "size" zero if the socket was closed for
364 * writing in the meantime.
367 * @param size number of bytes available in buf
368 * @param buf where the callee should write the message
369 * @return number of bytes written to buf
372 do_transmit (void *cls, size_t size, void *buf)
374 struct Session *session = cls;
375 struct PendingMessage *pm;
380 session->transmit_handle = NULL;
384 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
386 "Timeout trying to transmit to peer `%4s', discarding message queue.\n",
387 GNUNET_i2s (&session->target));
390 while (NULL != (pm = session->pending_messages_head))
392 GNUNET_CONTAINER_DLL_remove (session->pending_messages_head,
393 session->pending_messages_tail,
396 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
398 "Failed to transmit %u byte message to `%4s'.\n",
400 GNUNET_i2s (&session->target));
402 if (pm->transmit_cont != NULL)
403 pm->transmit_cont (pm->transmit_cont_cls,
404 &session->target, GNUNET_SYSERR);
411 while (NULL != (pm = session->pending_messages_head))
413 if (size < pm->message_size)
415 memcpy (cbuf, pm->msg, pm->message_size);
416 cbuf += pm->message_size;
417 ret += pm->message_size;
418 size -= pm->message_size;
419 GNUNET_CONTAINER_DLL_remove (session->pending_messages_head,
420 session->pending_messages_tail,
422 if (pm->transmit_cont != NULL)
423 pm->transmit_cont (pm->transmit_cont_cls,
424 &session->target, GNUNET_OK);
427 if (session->client != NULL)
428 process_pending_messages (session);
430 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
431 "tcp", "Transmitting %u bytes\n", ret);
438 * If we have pending messages, ask the server to
439 * transmit them (schedule the respective tasks, etc.)
441 * @param session for which session should we do this
444 process_pending_messages (struct Session *session)
446 struct PendingMessage *pm;
447 GNUNET_assert (session->client != NULL);
448 if (session->transmit_handle != NULL)
450 if (NULL == (pm = session->pending_messages_head))
452 session->transmit_handle
453 = GNUNET_SERVER_notify_transmit_ready (session->client,
455 GNUNET_TIME_absolute_get_remaining
457 &do_transmit, session);
462 * Functions with this signature are called whenever we need
463 * to close a session due to a disconnect or failure to
464 * establish a connection.
466 * @param session session to close down
469 disconnect_session (struct Session *session)
471 struct Session *prev;
473 struct PendingMessage *pm;
476 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
478 "Disconnecting from `%4s' at %s (session %p).\n",
479 GNUNET_i2s (&session->target),
480 (session->connect_addr != NULL) ?
481 GNUNET_a2s (session->connect_addr,
482 session->connect_alen) : "*", session);
484 /* remove from session list */
486 pos = session->plugin->sessions;
487 while (pos != session)
493 session->plugin->sessions = session->next;
495 prev->next = session->next;
497 if (session->transmit_handle != NULL)
499 GNUNET_CONNECTION_notify_transmit_ready_cancel
500 (session->transmit_handle);
501 session->transmit_handle = NULL;
503 while (NULL != (pm = session->pending_messages_head))
506 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
508 pm->transmit_cont != NULL
509 ? "Could not deliver message to `%4s'.\n"
511 "Could not deliver message to `%4s', notifying.\n",
512 GNUNET_i2s (&session->target));
514 GNUNET_CONTAINER_DLL_remove (session->pending_messages_head,
515 session->pending_messages_tail,
517 if (NULL != pm->transmit_cont)
518 pm->transmit_cont (pm->transmit_cont_cls,
519 &session->target, GNUNET_SYSERR);
522 if (GNUNET_NO == session->expecting_welcome)
525 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
527 "Notifying transport service about loss of data connection with `%4s'.\n",
528 GNUNET_i2s (&session->target));
530 /* Data session that actually went past the initial handshake;
531 transport service may know about this one, so we need to
532 notify transport service about disconnect */
533 // FIXME: we should have a very clear connect-disconnect
534 // protocol with gnunet-service-transport!
535 session->plugin->env->receive (session->plugin->env->cls,
536 &session->target, NULL,
538 session->connect_addr,
539 session->connect_alen);
541 if (session->client != NULL)
543 GNUNET_SERVER_client_drop (session->client);
544 session->client = NULL;
546 GNUNET_free_non_null (session->connect_addr);
547 GNUNET_free (session);
552 * Function that can be used by the transport service to transmit
553 * a message using the plugin. Note that in the case of a
554 * peer disconnecting, the continuation MUST be called
555 * prior to the disconnect notification itself. This function
556 * will be called with this peer's HELLO message to initiate
557 * a fresh connection to another peer.
560 * @param target who should receive this message
561 * @param msg the message to transmit
562 * @param priority how important is the message (most plugins will
563 * ignore message priority and just FIFO)
564 * @param timeout how long to wait at most for the transmission (does not
565 * require plugins to discard the message after the timeout,
566 * just advisory for the desired delay; most plugins will ignore
568 * @param addr the address to use (can be NULL if the plugin
569 * is "on its own" (i.e. re-use existing TCP connection))
570 * @param addrlen length of the address in bytes
571 * @param force_address GNUNET_YES if the plugin MUST use the given address,
572 * otherwise the plugin may use other addresses or
573 * existing connections (if available)
574 * @param cont continuation to call once the message has
575 * been transmitted (or if the transport is ready
576 * for the next transmission call; or if the
577 * peer disconnected...); can be NULL
578 * @param cont_cls closure for cont
579 * @return number of bytes used (on the physical network, with overheads);
580 * -1 on hard errors (i.e. address invalid); 0 is a legal value
581 * and does NOT mean that the message was not transmitted (DV)
584 tcp_plugin_send (void *cls,
585 const struct GNUNET_PeerIdentity *target,
589 struct GNUNET_TIME_Relative timeout,
593 GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls)
595 struct Plugin *plugin = cls;
596 struct Session *session;
597 struct PendingMessage *pm;
598 struct GNUNET_CONNECTION_Handle *sa;
601 session = find_session_by_target (plugin, target);
602 if ( (session != NULL) && ((GNUNET_YES == force_address) &&
603 ( (session->connect_alen != addrlen) ||
604 (0 != memcmp (session->connect_addr,
607 session = NULL; /* ignore existing session */
609 if ( (session == NULL) &&
613 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
615 "Asked to transmit to `%4s' without address and I have no existing connection (failing).\n",
616 GNUNET_i2s (target));
622 if (sizeof (struct sockaddr_in) == addrlen)
624 else if (sizeof (struct sockaddr_in6) == addrlen)
631 sa = GNUNET_CONNECTION_create_from_sockaddr (plugin->env->sched,
633 GNUNET_SERVER_MAX_MESSAGE_SIZE);
637 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
639 "Failed to create connection to `%4s' at `%s'\n",
641 GNUNET_a2s (addr, addrlen));
647 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
649 "Asked to transmit to `%4s', creating fresh session.\n",
650 GNUNET_i2s (target));
652 session = create_session (plugin,
654 GNUNET_SERVER_connect_socket (plugin->server,
656 session->connect_addr = GNUNET_malloc (addrlen);
657 memcpy (session->connect_addr,
660 session->connect_alen = addrlen;
662 GNUNET_assert (session != NULL);
663 GNUNET_assert (session->client != NULL);
666 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
668 "Creating pending message of size %d\n",
671 /* create new message entry */
672 pm = GNUNET_malloc (sizeof (struct PendingMessage) + msgbuf_size);
673 pm->msg = (const char*) &pm[1];
674 memcpy (&pm[1], msg, msgbuf_size);
675 pm->message_size = msgbuf_size;
676 pm->timeout = GNUNET_TIME_relative_to_absolute (timeout);
677 pm->transmit_cont = cont;
678 pm->transmit_cont_cls = cont_cls;
680 /* append pm to pending_messages list */
681 GNUNET_CONTAINER_DLL_insert_after (session->pending_messages_head,
682 session->pending_messages_tail,
683 session->pending_messages_tail,
686 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
688 "Asked to transmit %u bytes to `%s', added message to list.\n",
690 GNUNET_i2s (target));
692 process_pending_messages (session);
698 * Function that can be called to force a disconnect from the
699 * specified neighbour. This should also cancel all previously
700 * scheduled transmissions. Obviously the transmission may have been
701 * partially completed already, which is OK. The plugin is supposed
702 * to close the connection (if applicable) and no longer call the
703 * transmit continuation(s).
705 * Finally, plugin MUST NOT call the services's receive function to
706 * notify the service that the connection to the specified target was
707 * closed after a getting this call.
710 * @param target peer for which the last transmission is
714 tcp_plugin_disconnect (void *cls, const struct GNUNET_PeerIdentity *target)
716 struct Plugin *plugin = cls;
717 struct Session *session;
718 struct PendingMessage *pm;
721 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
723 "Asked to cancel session with `%4s'\n",
724 GNUNET_i2s (target));
726 session = plugin->sessions;
727 while (NULL != session)
729 if (0 == memcmp (target,
731 sizeof (struct GNUNET_PeerIdentity)))
733 pm = session->pending_messages_head;
736 pm->transmit_cont = NULL;
737 pm->transmit_cont_cls = NULL;
740 if (session->client != NULL)
742 GNUNET_SERVER_client_drop (session->client);
743 session->client = NULL;
745 /* rest of the clean-up of the session will be done as part of
746 disconnect_notify which should be triggered any time now
747 (or which may be triggering this call in the first place) */
749 session = session->next;
754 struct PrettyPrinterContext
756 GNUNET_TRANSPORT_AddressStringCallback asc;
763 * Append our port and forward the result.
766 append_port (void *cls, const char *hostname)
768 struct PrettyPrinterContext *ppc = cls;
771 if (hostname == NULL)
773 ppc->asc (ppc->asc_cls, NULL);
777 GNUNET_asprintf (&ret, "%s:%d", hostname, ppc->port);
778 ppc->asc (ppc->asc_cls, ret);
784 * Convert the transports address to a nice, human-readable
788 * @param type name of the transport that generated the address
789 * @param addr one of the addresses of the host, NULL for the last address
790 * the specific address format depends on the transport
791 * @param addrlen length of the address
792 * @param numeric should (IP) addresses be displayed in numeric form?
793 * @param timeout after how long should we give up?
794 * @param asc function to call on each string
795 * @param asc_cls closure for asc
798 tcp_plugin_address_pretty_printer (void *cls,
803 struct GNUNET_TIME_Relative timeout,
804 GNUNET_TRANSPORT_AddressStringCallback asc,
807 struct Plugin *plugin = cls;
808 const struct sockaddr_in *v4;
809 const struct sockaddr_in6 *v6;
810 struct PrettyPrinterContext *ppc;
812 if ((addrlen != sizeof (struct sockaddr_in)) &&
813 (addrlen != sizeof (struct sockaddr_in6)))
815 /* invalid address */
820 ppc = GNUNET_malloc (sizeof (struct PrettyPrinterContext));
822 ppc->asc_cls = asc_cls;
823 if (addrlen == sizeof (struct sockaddr_in))
825 v4 = (const struct sockaddr_in *) addr;
826 ppc->port = ntohs (v4->sin_port);
830 v6 = (const struct sockaddr_in6 *) addr;
831 ppc->port = ntohs (v6->sin6_port);
834 GNUNET_RESOLVER_hostname_get (plugin->env->sched,
838 !numeric, timeout, &append_port, ppc);
843 * Update the last-received and bandwidth quota values
846 * @param session session to update
847 * @param force set to GNUNET_YES if we should update even
848 * though the minimum refresh time has not yet expired
851 update_quota (struct Session *session, int force)
853 struct GNUNET_TIME_Absolute now;
854 unsigned long long delta;
855 unsigned long long total_allowed;
856 unsigned long long total_remaining;
858 now = GNUNET_TIME_absolute_get ();
859 delta = now.value - session->last_quota_update.value;
860 if ((delta < MIN_QUOTA_REFRESH_TIME) && (!force))
861 return; /* too early, not enough data */
863 total_allowed = session->quota_in * delta;
864 if (total_allowed > session->last_received)
866 /* got less than acceptable */
867 total_remaining = total_allowed - session->last_received;
868 session->last_received = 0;
869 delta = total_remaining / session->quota_in; /* bonus seconds */
870 if (delta > MAX_BANDWIDTH_CARRY)
871 delta = MAX_BANDWIDTH_CARRY; /* limit amount of carry-over */
875 /* got more than acceptable */
876 session->last_received -= total_allowed;
879 session->last_quota_update.value = now.value - delta;
884 * Set a quota for receiving data from the given peer; this is a
885 * per-transport limit. The transport should limit its read/select
886 * calls to stay below the quota (in terms of incoming data).
889 * @param target the peer for whom the quota is given
890 * @param quota_in quota for receiving/sending data in bytes per ms
893 tcp_plugin_set_receive_quota (void *cls,
894 const struct GNUNET_PeerIdentity *target,
897 struct Plugin *plugin = cls;
898 struct Session *session;
900 session = find_session_by_target (plugin, target);
902 return; /* peer must have disconnected, ignore */
903 if (session->quota_in != quota_in)
905 update_quota (session, GNUNET_YES);
906 if (session->quota_in > quota_in)
907 session->last_quota_update = GNUNET_TIME_absolute_get ();
908 session->quota_in = quota_in;
914 * Check if the given port is plausible (must be either
915 * our listen port or our advertised port). If it is
916 * neither, we return one of these two ports at random.
918 * @return either in_port or a more plausible port
921 check_port (struct Plugin *plugin, uint16_t in_port)
923 if ((in_port == plugin->adv_port) || (in_port == plugin->open_port))
925 return (GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
927 ? plugin->open_port : plugin->adv_port;
932 * Another peer has suggested an address for this peer and transport
933 * plugin. Check that this could be a valid address.
936 * @param addr pointer to the address
937 * @param addrlen length of addr
938 * @return GNUNET_OK if this is a plausible address for this peer
942 tcp_plugin_check_address (void *cls, void *addr, size_t addrlen)
944 struct Plugin *plugin = cls;
945 char buf[sizeof (struct sockaddr_in6)];
946 struct sockaddr_in *v4;
947 struct sockaddr_in6 *v6;
949 if ((addrlen != sizeof (struct sockaddr_in)) &&
950 (addrlen != sizeof (struct sockaddr_in6)))
953 return GNUNET_SYSERR;
955 memcpy (buf, addr, sizeof (struct sockaddr_in6));
956 if (addrlen == sizeof (struct sockaddr_in))
958 v4 = (struct sockaddr_in *) buf;
959 v4->sin_port = htons (check_port (plugin, ntohs (v4->sin_port)));
963 v6 = (struct sockaddr_in6 *) buf;
964 v6->sin6_port = htons (check_port (plugin, ntohs (v6->sin6_port)));
967 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
969 "Informing transport service about my address `%s'.\n",
970 GNUNET_a2s (addr, addrlen));
977 * We've received a welcome from this peer via TCP. Possibly create a
978 * fresh client record and send back our welcome.
981 * @param client identification of the client
982 * @param message the actual message
985 handle_tcp_welcome (void *cls,
986 struct GNUNET_SERVER_Client *client,
987 const struct GNUNET_MessageHeader *message)
989 struct Plugin *plugin = cls;
990 const struct WelcomeMessage *wm = (const struct WelcomeMessage *) message;
991 struct Session *session;
996 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
998 "Received `%s' message from a `%4s/%p'.\n", "WELCOME",
999 GNUNET_i2s (&wm->clientIdentity), client);
1002 session = find_session_by_client (plugin, client);
1003 if (session == NULL)
1005 GNUNET_SERVER_client_keep (client);
1006 session = create_session (plugin,
1007 &wm->clientIdentity, client);
1009 GNUNET_SERVER_client_get_address (client, &vaddr, &alen))
1012 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1014 "Found address `%s' for incoming connection %p\n",
1015 GNUNET_a2s (vaddr, alen),
1018 session->connect_addr = vaddr;
1019 session->connect_alen = alen;
1024 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1026 "Did not obtain TCP socket address for incoming connection\n");
1030 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1032 "Creating new session %p for connection %p\n",
1035 process_pending_messages (session);
1037 if (session->expecting_welcome != GNUNET_YES)
1039 GNUNET_break_op (0);
1040 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1043 session->expecting_welcome = GNUNET_NO;
1044 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1049 * Calculate how long we should delay reading from the TCP socket to
1050 * ensure that we stay within our bandwidth limits (push back).
1052 * @param session for which client should this be calculated
1054 static struct GNUNET_TIME_Relative
1055 calculate_throttle_delay (struct Session *session)
1057 struct GNUNET_TIME_Relative ret;
1058 struct GNUNET_TIME_Absolute now;
1063 now = GNUNET_TIME_absolute_get ();
1064 del = now.value - session->last_quota_update.value;
1065 if (del > MAX_BANDWIDTH_CARRY)
1067 update_quota (session, GNUNET_YES);
1068 del = now.value - session->last_quota_update.value;
1069 GNUNET_assert (del <= MAX_BANDWIDTH_CARRY);
1071 if (session->quota_in == 0)
1072 session->quota_in = 1; /* avoid divison by zero */
1073 avail = del * session->quota_in;
1074 if (avail > session->last_received)
1075 return GNUNET_TIME_UNIT_ZERO; /* can receive right now */
1076 excess = session->last_received - avail;
1077 ret.value = excess / session->quota_in;
1083 * Task to signal the server that we can continue
1084 * receiving from the TCP client now.
1087 delayed_done (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1089 struct Session *session = cls;
1090 GNUNET_SERVER_receive_done (session->client, GNUNET_OK);
1095 * We've received data for this peer via TCP. Unbox,
1096 * compute latency and forward.
1098 * @param cls closure
1099 * @param client identification of the client
1100 * @param message the actual message
1103 handle_tcp_data (void *cls,
1104 struct GNUNET_SERVER_Client *client,
1105 const struct GNUNET_MessageHeader *message)
1107 struct Plugin *plugin = cls;
1108 struct Session *session;
1110 struct GNUNET_TIME_Relative delay;
1112 msize = ntohs (message->size);
1113 session = find_session_by_client (plugin, client);
1115 if (GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME == ntohs(message->type))
1117 /* We don't want to propagate WELCOME messages up! */
1118 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1121 if ( (NULL == session) || (GNUNET_NO != session->expecting_welcome))
1123 GNUNET_break_op (0);
1124 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1128 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1130 "Passing %u bytes of type %u from `%4s' to transport service.\n",
1131 (unsigned int) msize,
1132 (unsigned int) ntohs (message->type),
1133 GNUNET_i2s (&session->target));
1135 plugin->env->receive (plugin->env->cls, &session->target, message, 1,
1136 session->connect_addr,
1137 session->connect_alen);
1138 /* update bandwidth used */
1139 session->last_received += msize;
1140 update_quota (session, GNUNET_NO);
1141 delay = calculate_throttle_delay (session);
1142 if (delay.value == 0)
1143 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1145 GNUNET_SCHEDULER_add_delayed (session->plugin->env->sched,
1146 delay, &delayed_done, session);
1151 * Handlers for the various TCP messages.
1153 static struct GNUNET_SERVER_MessageHandler my_handlers[] = {
1154 {&handle_tcp_welcome, NULL, GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME,
1155 sizeof (struct WelcomeMessage)},
1156 {&handle_tcp_data, NULL, GNUNET_MESSAGE_TYPE_ALL, 0},
1162 * Functions with this signature are called whenever a peer
1163 * is disconnected on the network level.
1165 * @param cls closure
1166 * @param client identification of the client
1169 disconnect_notify (void *cls, struct GNUNET_SERVER_Client *client)
1171 struct Plugin *plugin = cls;
1172 struct Session *session;
1176 session = find_session_by_client (plugin, client);
1177 if (session == NULL)
1178 return; /* unknown, nothing to do */
1180 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1182 "Destroying session of `%4s' with %s (%p) due to network-level disconnect.\n",
1183 GNUNET_i2s (&session->target),
1184 (session->connect_addr != NULL) ?
1185 GNUNET_a2s (session->connect_addr,
1186 session->connect_alen) : "*", client);
1188 disconnect_session (session);
1193 * Add the IP of our network interface to the list of
1194 * our external IP addresses.
1197 process_interfaces (void *cls,
1200 const struct sockaddr *addr, socklen_t addrlen)
1202 struct Plugin *plugin = cls;
1204 struct sockaddr_in *v4;
1205 struct sockaddr_in6 *v6;
1207 af = addr->sa_family;
1210 v4 = (struct sockaddr_in *) addr;
1211 v4->sin_port = htons (plugin->adv_port);
1215 GNUNET_assert (af == AF_INET6);
1216 v6 = (struct sockaddr_in6 *) addr;
1217 v6->sin6_port = htons (plugin->adv_port);
1219 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO |
1220 GNUNET_ERROR_TYPE_BULK,
1221 "tcp", _("Found address `%s' (%s)\n"),
1222 GNUNET_a2s (addr, addrlen), name);
1223 plugin->env->notify_address (plugin->env->cls,
1225 addr, addrlen, GNUNET_TIME_UNIT_FOREVER_REL);
1231 * Function called by the resolver for each address obtained from DNS
1232 * for our own hostname. Add the addresses to the list of our
1233 * external IP addresses.
1235 * @param cls closure
1236 * @param addr one of the addresses of the host, NULL for the last address
1237 * @param addrlen length of the address
1240 process_hostname_ips (void *cls,
1241 const struct sockaddr *addr, socklen_t addrlen)
1243 struct Plugin *plugin = cls;
1247 plugin->hostname_dns = NULL;
1250 process_interfaces (plugin, "<hostname>", GNUNET_YES, addr, addrlen);
1255 * Entry point for the plugin.
1258 libgnunet_plugin_transport_tcp_init (void *cls)
1260 struct GNUNET_TRANSPORT_PluginEnvironment *env = cls;
1261 struct GNUNET_TRANSPORT_PluginFunctions *api;
1262 struct Plugin *plugin;
1263 struct GNUNET_SERVICE_Context *service;
1264 unsigned long long aport;
1265 unsigned long long bport;
1268 service = GNUNET_SERVICE_start ("transport-tcp", env->sched, env->cfg);
1269 if (service == NULL)
1271 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING,
1274 ("Failed to start service for `%s' transport plugin.\n"),
1280 GNUNET_CONFIGURATION_get_value_number (env->cfg,
1286 GNUNET_CONFIGURATION_get_value_number (env->cfg,
1289 &aport)) && (aport > 65535)))
1291 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
1294 ("Require valid port number for service `%s' in configuration!\n"),
1296 GNUNET_SERVICE_stop (service);
1301 plugin = GNUNET_malloc (sizeof (struct Plugin));
1302 plugin->open_port = bport;
1303 plugin->adv_port = aport;
1305 plugin->lsock = NULL;
1306 plugin->statistics = NULL;
1307 api = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_PluginFunctions));
1309 api->send = &tcp_plugin_send;
1310 api->disconnect = &tcp_plugin_disconnect;
1311 api->address_pretty_printer = &tcp_plugin_address_pretty_printer;
1312 api->set_receive_quota = &tcp_plugin_set_receive_quota;
1313 api->check_address = &tcp_plugin_check_address;
1314 plugin->service = service;
1315 plugin->server = GNUNET_SERVICE_get_server (service);
1316 plugin->handlers = GNUNET_malloc (sizeof (my_handlers));
1317 memcpy (plugin->handlers, my_handlers, sizeof (my_handlers));
1320 sizeof (my_handlers) / sizeof (struct GNUNET_SERVER_MessageHandler);
1322 plugin->handlers[i].callback_cls = plugin;
1323 GNUNET_SERVER_add_handlers (plugin->server, plugin->handlers);
1325 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
1326 "tcp", _("TCP transport listening on port %llu\n"), bport);
1328 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
1331 ("TCP transport advertises itself as being on port %llu\n"),
1333 GNUNET_SERVER_disconnect_notify (plugin->server, &disconnect_notify,
1335 /* FIXME: do the two calls below periodically again and
1336 not just once (since the info we get might change...) */
1337 GNUNET_OS_network_interfaces_list (&process_interfaces, plugin);
1338 plugin->hostname_dns = GNUNET_RESOLVER_hostname_resolve (env->sched,
1341 HOSTNAME_RESOLVE_TIMEOUT,
1342 &process_hostname_ips,
1349 * Exit point from the plugin.
1352 libgnunet_plugin_transport_tcp_done (void *cls)
1354 struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
1355 struct Plugin *plugin = api->cls;
1356 struct Session *session;
1358 while (NULL != (session = plugin->sessions))
1359 disconnect_session (session);
1360 if (NULL != plugin->hostname_dns)
1362 GNUNET_RESOLVER_request_cancel (plugin->hostname_dns);
1363 plugin->hostname_dns = NULL;
1365 GNUNET_SERVICE_stop (plugin->service);
1366 GNUNET_free (plugin->handlers);
1367 GNUNET_free (plugin);
1372 /* end of plugin_transport_tcp.c */