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.
10 GNUnet is distributed in the hope that it will be useful, but
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_os_lib.h"
31 #include "gnunet_protocols.h"
32 #include "gnunet_resolver_service.h"
33 #include "gnunet_server_lib.h"
34 #include "gnunet_service_lib.h"
35 #include "gnunet_signatures.h"
36 #include "gnunet_statistics_service.h"
37 #include "gnunet_transport_service.h"
38 #include "plugin_transport.h"
39 #include "transport.h"
41 #define DEBUG_TCP GNUNET_NO
44 * How long until we give up on transmitting the welcome message?
46 #define WELCOME_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
49 * How long until we give up on transmitting the welcome message?
51 #define HOSTNAME_RESOLVE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
55 * Initial handshake message for a session.
60 * Type is GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME.
62 struct GNUNET_MessageHeader header;
65 * Identity of the node connecting (TCP client)
67 struct GNUNET_PeerIdentity clientIdentity;
73 * Encapsulation of all of the state of the plugin.
79 * Information kept for each message that is yet to
86 * This is a linked list.
88 struct PendingMessage *next;
96 * So that the gnunet_transport_service can group messages together,
97 * these pending messages need to accept a message buffer and size
98 * instead of just a GNUNET_MessageHeader.
103 * Continuation function to call once the message
104 * has been sent. Can be NULL if there is no
105 * continuation to call.
107 GNUNET_TRANSPORT_TransmitContinuation transmit_cont;
110 * Closure for transmit_cont.
112 void *transmit_cont_cls;
115 * Timeout value for the pending message.
117 struct GNUNET_TIME_Absolute timeout;
123 * Session handle for TCP connections.
129 * Stored in a linked list.
131 struct Session *next;
134 * Pointer to the global plugin struct.
136 struct Plugin *plugin;
139 * The client (used to identify this connection)
141 struct GNUNET_SERVER_Client *client;
144 * Messages currently pending for transmission
145 * to this peer, if any.
147 struct PendingMessage *pending_messages;
150 * Handle for pending transmission request.
152 struct GNUNET_CONNECTION_TransmitHandle *transmit_handle;
155 * To whom are we talking to (set to our identity
156 * if we are still waiting for the welcome message)
158 struct GNUNET_PeerIdentity target;
161 * At what time did we reset last_received last?
163 struct GNUNET_TIME_Absolute last_quota_update;
166 * Address of the other peer (either based on our 'connect'
167 * call or on our 'accept' call).
172 * How many bytes have we received since the "last_quota_update"
175 uint64_t last_received;
178 * Number of bytes per ms that this peer is allowed
184 * Length of connect_addr.
189 * Are we still expecting the welcome message? (GNUNET_YES/GNUNET_NO)
190 * GNUNET_SYSERR is used to mark non-welcoming connections (HELLO
193 int expecting_welcome;
199 * Encapsulation of all of the state of the plugin.
206 struct GNUNET_TRANSPORT_PluginEnvironment *env;
211 struct GNUNET_CONNECTION_Handle *lsock;
214 * List of open TCP sessions.
216 struct Session *sessions;
219 * Handle for the statistics service.
221 struct GNUNET_STATISTICS_Handle *statistics;
224 * Handle to the network service.
226 struct GNUNET_SERVICE_Context *service;
229 * Handle to the server for this service.
231 struct GNUNET_SERVER_Handle *server;
234 * Copy of the handler array where the closures are
235 * set to this struct's instance.
237 struct GNUNET_SERVER_MessageHandler *handlers;
240 * Handle for request of hostname resolution, non-NULL if pending.
242 struct GNUNET_RESOLVER_RequestHandle *hostname_dns;
245 * ID of task used to update our addresses when one expires.
247 GNUNET_SCHEDULER_TaskIdentifier address_update_task;
250 * Port that we are actually listening on.
255 * Port that the user said we would have visible to the
264 * Find the session handle for the given peer.
266 static struct Session *
267 find_session_by_target (struct Plugin *plugin,
268 const struct GNUNET_PeerIdentity *target)
272 ret = plugin->sessions;
273 while ( (ret != NULL) &&
274 ((GNUNET_SYSERR == ret->expecting_welcome) ||
275 (0 != memcmp (target,
276 &ret->target, sizeof (struct GNUNET_PeerIdentity)))))
283 * Find the session handle for the given peer.
285 static struct Session *
286 find_session_by_client (struct Plugin *plugin,
287 const struct GNUNET_SERVER_Client *client)
291 ret = plugin->sessions;
292 while ((ret != NULL) && (client != ret->client))
299 * Create a welcome message.
301 static struct PendingMessage *
302 create_welcome (struct Plugin *plugin)
304 struct PendingMessage *pm;
305 struct WelcomeMessage *welcome;
307 pm = GNUNET_malloc (sizeof (struct PendingMessage));
308 pm->msg = GNUNET_malloc(sizeof(struct WelcomeMessage));
309 welcome = (struct WelcomeMessage *)pm->msg;
310 pm->message_size = sizeof (struct WelcomeMessage);
311 welcome->header.size = htons (sizeof (struct WelcomeMessage));
312 welcome->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME);
313 welcome->clientIdentity = *plugin->env->my_identity;
314 pm->timeout = GNUNET_TIME_relative_to_absolute (WELCOME_TIMEOUT);
320 * Create a new session.
323 * @param target peer to connect to
324 * @param client client to use
325 * @return new session object
327 static struct Session *
328 create_session (struct Plugin *plugin,
329 const struct GNUNET_PeerIdentity *target,
330 struct GNUNET_SERVER_Client *client)
334 ret = GNUNET_malloc (sizeof (struct Session));
335 ret->plugin = plugin;
336 ret->next = plugin->sessions;
337 plugin->sessions = ret;
338 ret->client = client;
339 ret->target = *target;
340 ret->last_quota_update = GNUNET_TIME_absolute_get ();
341 ret->quota_in = plugin->env->default_quota_in;
342 ret->expecting_welcome = GNUNET_YES;
343 ret->pending_messages = create_welcome (plugin);
349 * If we have pending messages, ask the server to
350 * transmit them (schedule the respective tasks, etc.)
352 * @param session for which session should we do this
354 static void process_pending_messages (struct Session *session);
358 * Function called to notify a client about the socket
359 * being ready to queue more data. "buf" will be
360 * NULL and "size" zero if the socket was closed for
361 * writing in the meantime.
364 * @param size number of bytes available in buf
365 * @param buf where the callee should write the message
366 * @return number of bytes written to buf
369 do_transmit (void *cls, size_t size, void *buf)
371 struct Session *session = cls;
372 struct PendingMessage *pm;
377 session->transmit_handle = NULL;
381 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
383 "Timeout trying to transmit to peer `%4s', discarding message queue.\n",
384 GNUNET_i2s (&session->target));
387 while (NULL != (pm = session->pending_messages))
389 session->pending_messages = pm->next;
391 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
393 "Failed to transmit message of to `%4s'.\n",
394 GNUNET_i2s (&session->target));
396 if (pm->transmit_cont != NULL)
397 pm->transmit_cont (pm->transmit_cont_cls,
398 &session->target, GNUNET_SYSERR);
405 while (NULL != (pm = session->pending_messages))
407 if (size < pm->message_size)
409 memcpy (cbuf, pm->msg, pm->message_size);
410 cbuf += pm->message_size;
411 ret += pm->message_size;
412 size -= pm->message_size;
413 session->pending_messages = pm->next;
414 if (pm->transmit_cont != NULL)
415 pm->transmit_cont (pm->transmit_cont_cls,
416 &session->target, GNUNET_OK);
419 if (session->client != NULL)
420 process_pending_messages (session);
422 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
423 "tcp", "Transmitting %u bytes\n", ret);
430 * If we have pending messages, ask the server to
431 * transmit them (schedule the respective tasks, etc.)
433 * @param session for which session should we do this
436 process_pending_messages (struct Session *session)
438 struct PendingMessage *pm;
439 GNUNET_assert (session->client != NULL);
440 if (session->transmit_handle != NULL)
442 if (NULL == (pm = session->pending_messages))
444 session->transmit_handle
445 = GNUNET_SERVER_notify_transmit_ready (session->client,
447 GNUNET_TIME_absolute_get_remaining
449 &do_transmit, session);
454 * Functions with this signature are called whenever we need
455 * to close a session due to a disconnect or failure to
456 * establish a connection.
458 * @param session session to close down
461 disconnect_session (struct Session *session)
463 struct Session *prev;
465 struct PendingMessage *pm;
468 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
470 "Disconnecting from `%4s' at %s (session %p).\n",
471 GNUNET_i2s (&session->target),
472 (session->connect_addr != NULL) ?
473 GNUNET_a2s (session->connect_addr,
474 session->connect_alen) : "*", session);
476 /* remove from session list */
478 pos = session->plugin->sessions;
479 while (pos != session)
485 session->plugin->sessions = session->next;
487 prev->next = session->next;
489 if (session->transmit_handle != NULL)
491 GNUNET_CONNECTION_notify_transmit_ready_cancel
492 (session->transmit_handle);
493 session->transmit_handle = NULL;
495 while (NULL != (pm = session->pending_messages))
498 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
500 pm->transmit_cont != NULL
501 ? "Could not deliver message to `%4s'.\n"
503 "Could not deliver message to `%4s', notifying.\n",
504 GNUNET_i2s (&session->target));
506 session->pending_messages = pm->next;
507 if (NULL != pm->transmit_cont)
508 pm->transmit_cont (pm->transmit_cont_cls,
509 &session->target, GNUNET_SYSERR);
510 GNUNET_free(pm->msg);
513 if (GNUNET_NO == session->expecting_welcome)
516 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
518 "Notifying transport service about loss of data connection with `%4s'.\n",
519 GNUNET_i2s (&session->target));
521 /* Data session that actually went past the
522 initial handshake; transport service may
523 know about this one, so we need to
524 notify transport service about disconnect */
525 session->plugin->env->receive (session->plugin->env->cls,
526 &session->target, NULL,
528 session->connect_addr,
529 session->connect_alen);
531 if (session->client != NULL)
533 GNUNET_SERVER_client_drop (session->client);
534 session->client = NULL;
536 GNUNET_free_non_null (session->connect_addr);
537 GNUNET_free (session);
542 * Function that can be used by the transport service to transmit
543 * a message using the plugin. Note that in the case of a
544 * peer disconnecting, the continuation MUST be called
545 * prior to the disconnect notification itself. This function
546 * will be called with this peer's HELLO message to initiate
547 * a fresh connection to another peer.
550 * @param target who should receive this message
551 * @param msg the message to transmit
552 * @param priority how important is the message (most plugins will
553 * ignore message priority and just FIFO)
554 * @param timeout how long to wait at most for the transmission (does not
555 * require plugins to discard the message after the timeout,
556 * just advisory for the desired delay; most plugins will ignore
558 * @param addr the address to use (can be NULL if the plugin
559 * is "on its own" (i.e. re-use existing TCP connection))
560 * @param addrlen length of the address in bytes
561 * @param force_address GNUNET_YES if the plugin MUST use the given address,
562 * otherwise the plugin may use other addresses or
563 * existing connections (if available)
564 * @param cont continuation to call once the message has
565 * been transmitted (or if the transport is ready
566 * for the next transmission call; or if the
567 * peer disconnected...); can be NULL
568 * @param cont_cls closure for cont
569 * @return number of bytes used (on the physical network, with overheads);
570 * -1 on hard errors (i.e. address invalid); 0 is a legal value
571 * and does NOT mean that the message was not transmitted (DV)
574 tcp_plugin_send (void *cls,
575 const struct GNUNET_PeerIdentity *target,
579 struct GNUNET_TIME_Relative timeout,
583 GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls)
585 struct Plugin *plugin = cls;
586 struct Session *session;
587 struct PendingMessage *pm;
588 struct PendingMessage *pme;
589 struct GNUNET_CONNECTION_Handle *sa;
592 session = find_session_by_target (plugin, target);
593 if ( (session != NULL) && ((GNUNET_YES == force_address) &&
594 ( (session->connect_alen != addrlen) ||
595 (0 != memcmp (session->connect_addr,
598 session = NULL; /* ignore existing session */
600 if ( (session == NULL) &&
604 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
606 "Asked to transmit to `%4s' without address and I have no existing connection (failing).\n",
607 GNUNET_i2s (target));
613 if (sizeof (struct sockaddr_in) == addrlen)
615 else if (sizeof (struct sockaddr_in6) == addrlen)
622 sa = GNUNET_CONNECTION_create_from_sockaddr (plugin->env->sched,
624 GNUNET_SERVER_MAX_MESSAGE_SIZE);
628 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
630 "Failed to create connection to `%4s' at `%s'\n",
632 GNUNET_a2s (addr, addrlen));
638 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
640 "Asked to transmit to `%4s', creating fresh session.\n",
641 GNUNET_i2s (target));
643 session = create_session (plugin,
645 GNUNET_SERVER_connect_socket (plugin->server,
647 session->connect_addr = GNUNET_malloc (addrlen);
648 memcpy (session->connect_addr,
651 session->connect_alen = addrlen;
653 GNUNET_assert (session != NULL);
654 GNUNET_assert (session->client != NULL);
657 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
659 "Creating pending message of size %d\n",
662 /* create new message entry */
663 pm = GNUNET_malloc (sizeof (struct PendingMessage));
664 pm->msg = GNUNET_malloc(msgbuf_size);
665 memcpy (pm->msg, msg, msgbuf_size);
666 pm->message_size = msgbuf_size;
667 pm->timeout = GNUNET_TIME_relative_to_absolute (timeout);
668 pm->transmit_cont = cont;
669 pm->transmit_cont_cls = cont_cls;
671 /* append pm to pending_messages list */
672 pme = session->pending_messages;
675 session->pending_messages = pm;
679 /* FIXME: this could be done faster by keeping
680 track of the tail of the list... */
681 while (NULL != pme->next)
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;
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 for incoming `%s' message\n",
1017 session->connect_addr = vaddr;
1018 session->connect_alen = alen;
1023 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1025 "Didn't find address for incoming `%s' message\n",
1030 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1032 "Creating new session %p for incoming `%s' message.\n",
1033 session, "WELCOME");
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))
1118 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1119 "tcp", "Received a welcome, NOT sending to clients!\n");
1121 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1122 return; /* We don't want to propagate WELCOME messages up! */
1125 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1126 "tcp", "Received DATA message, checking session!\n");
1128 if ( (NULL == session) || (GNUNET_NO != session->expecting_welcome))
1130 GNUNET_break_op (0);
1131 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1135 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1136 "tcp", "Receiving %u bytes from `%4s'.\n",
1137 msize, GNUNET_i2s (&session->target));
1140 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1142 "Forwarding %u bytes of data of type %u to transport service.\n",
1143 (unsigned int) msize,
1144 (unsigned int) ntohs (message->type));
1146 plugin->env->receive (plugin->env->cls, &session->target, message, 1,
1147 session->connect_addr,
1148 session->connect_alen);
1149 /* update bandwidth used */
1150 session->last_received += msize;
1151 update_quota (session, GNUNET_NO);
1152 delay = calculate_throttle_delay (session);
1153 if (delay.value == 0)
1154 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1156 GNUNET_SCHEDULER_add_delayed (session->plugin->env->sched,
1157 delay, &delayed_done, session);
1162 * Handlers for the various TCP messages.
1164 static struct GNUNET_SERVER_MessageHandler my_handlers[] = {
1165 {&handle_tcp_welcome, NULL, GNUNET_MESSAGE_TYPE_TRANSPORT_TCP_WELCOME,
1166 sizeof (struct WelcomeMessage)},
1167 {&handle_tcp_data, NULL, GNUNET_MESSAGE_TYPE_ALL, 0},
1173 create_tcp_handlers (struct Plugin *plugin)
1176 plugin->handlers = GNUNET_malloc (sizeof (my_handlers));
1177 memcpy (plugin->handlers, my_handlers, sizeof (my_handlers));
1180 sizeof (my_handlers) / sizeof (struct GNUNET_SERVER_MessageHandler);
1182 plugin->handlers[i].callback_cls = plugin;
1183 GNUNET_SERVER_add_handlers (plugin->server, plugin->handlers);
1188 * Functions with this signature are called whenever a peer
1189 * is disconnected on the network level.
1191 * @param cls closure
1192 * @param client identification of the client
1195 disconnect_notify (void *cls, struct GNUNET_SERVER_Client *client)
1197 struct Plugin *plugin = cls;
1198 struct Session *session;
1202 session = find_session_by_client (plugin, client);
1203 if (session == NULL)
1204 return; /* unknown, nothing to do */
1206 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1208 "Destroying session of `%4s' with %s (%p) due to network-level disconnect.\n",
1209 GNUNET_i2s (&session->target),
1210 (session->connect_addr != NULL) ?
1211 GNUNET_a2s (session->connect_addr,
1212 session->connect_alen) : "*", client);
1214 disconnect_session (session);
1219 * Add the IP of our network interface to the list of
1220 * our external IP addresses.
1223 process_interfaces (void *cls,
1226 const struct sockaddr *addr, socklen_t addrlen)
1228 struct Plugin *plugin = cls;
1230 struct sockaddr_in *v4;
1231 struct sockaddr_in6 *v6;
1233 af = addr->sa_family;
1236 v4 = (struct sockaddr_in *) addr;
1237 v4->sin_port = htons (plugin->adv_port);
1241 GNUNET_assert (af == AF_INET6);
1242 v6 = (struct sockaddr_in6 *) addr;
1243 v6->sin6_port = htons (plugin->adv_port);
1245 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO |
1246 GNUNET_ERROR_TYPE_BULK,
1247 "tcp", _("Found address `%s' (%s)\n"),
1248 GNUNET_a2s (addr, addrlen), name);
1249 plugin->env->notify_address (plugin->env->cls,
1251 addr, addrlen, GNUNET_TIME_UNIT_FOREVER_REL);
1257 * Function called by the resolver for each address obtained from DNS
1258 * for our own hostname. Add the addresses to the list of our
1259 * external IP addresses.
1261 * @param cls closure
1262 * @param addr one of the addresses of the host, NULL for the last address
1263 * @param addrlen length of the address
1266 process_hostname_ips (void *cls,
1267 const struct sockaddr *addr, socklen_t addrlen)
1269 struct Plugin *plugin = cls;
1273 plugin->hostname_dns = NULL;
1276 process_interfaces (plugin, "<hostname>", GNUNET_YES, addr, addrlen);
1281 * Entry point for the plugin.
1284 libgnunet_plugin_transport_tcp_init (void *cls)
1286 struct GNUNET_TRANSPORT_PluginEnvironment *env = cls;
1287 struct GNUNET_TRANSPORT_PluginFunctions *api;
1288 struct Plugin *plugin;
1289 struct GNUNET_SERVICE_Context *service;
1290 unsigned long long aport;
1291 unsigned long long bport;
1293 service = GNUNET_SERVICE_start ("transport-tcp", env->sched, env->cfg);
1294 if (service == NULL)
1296 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING,
1299 ("Failed to start service for `%s' transport plugin.\n"),
1305 GNUNET_CONFIGURATION_get_value_number (env->cfg,
1311 GNUNET_CONFIGURATION_get_value_number (env->cfg,
1314 &aport)) && (aport > 65535)))
1316 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
1319 ("Require valid port number for service `%s' in configuration!\n"),
1321 GNUNET_SERVICE_stop (service);
1326 plugin = GNUNET_malloc (sizeof (struct Plugin));
1327 plugin->open_port = bport;
1328 plugin->adv_port = aport;
1330 plugin->lsock = NULL;
1331 plugin->statistics = NULL;
1332 api = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_PluginFunctions));
1334 api->send = &tcp_plugin_send;
1335 api->disconnect = &tcp_plugin_disconnect;
1336 api->address_pretty_printer = &tcp_plugin_address_pretty_printer;
1337 api->set_receive_quota = &tcp_plugin_set_receive_quota;
1338 api->check_address = &tcp_plugin_check_address;
1339 plugin->service = service;
1340 plugin->server = GNUNET_SERVICE_get_server (service);
1341 create_tcp_handlers (plugin);
1342 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
1343 "tcp", _("TCP transport listening on port %llu\n"), bport);
1345 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
1348 ("TCP transport advertises itself as being on port %llu\n"),
1350 GNUNET_SERVER_disconnect_notify (plugin->server, &disconnect_notify,
1352 /* FIXME: do the two calls below periodically again and
1353 not just once (since the info we get might change...) */
1354 GNUNET_OS_network_interfaces_list (&process_interfaces, plugin);
1355 plugin->hostname_dns = GNUNET_RESOLVER_hostname_resolve (env->sched,
1358 HOSTNAME_RESOLVE_TIMEOUT,
1359 &process_hostname_ips,
1366 * Exit point from the plugin.
1369 libgnunet_plugin_transport_tcp_done (void *cls)
1371 struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
1372 struct Plugin *plugin = api->cls;
1373 struct Session *session;
1375 while (NULL != (session = plugin->sessions))
1376 disconnect_session (session);
1377 if (NULL != plugin->hostname_dns)
1379 GNUNET_RESOLVER_request_cancel (plugin->hostname_dns);
1380 plugin->hostname_dns = NULL;
1382 GNUNET_SERVICE_stop (plugin->service);
1383 GNUNET_free (plugin->handlers);
1384 GNUNET_free (plugin);
1389 /* end of plugin_transport_tcp.c */