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3 (C) 2002--2013 Christian Grothoff (and other contributing authors)
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22 * @file dv/plugin_transport_dv.c
23 * @brief DV transport service, takes incoming DV requests and deals with
25 * @author Nathan Evans
26 * @author Christian Grothoff
30 #include "gnunet_util_lib.h"
31 #include "gnunet_protocols.h"
32 #include "gnunet_statistics_service.h"
33 #include "gnunet_dv_service.h"
34 #include "gnunet_transport_service.h"
35 #include "gnunet_transport_plugin.h"
39 #define LOG(kind,...) GNUNET_log_from (kind, "transport-dv",__VA_ARGS__)
41 #define PLUGIN_NAME "dv"
44 * Encapsulation of all of the state of the plugin.
50 * An active request for transmission via DV.
58 struct PendingRequest *next;
63 struct PendingRequest *prev;
66 * Continuation function to call once the transmission buffer
67 * has again space available. NULL if there is no
68 * continuation to call.
70 GNUNET_TRANSPORT_TransmitContinuation transmit_cont;
73 * Closure for transmit_cont.
75 void *transmit_cont_cls;
78 * Transmission handle from DV client library.
80 struct GNUNET_DV_TransmitHandle *th;
83 * Session of this request.
85 struct Session *session;
91 * Session handle for connections.
97 * Mandatory session header.
99 struct SessionHeader header;
102 * Pointer to the global plugin struct.
104 struct Plugin *plugin;
107 * Head of pending requests.
109 struct PendingRequest *pr_head;
112 * Tail of pending requests.
114 struct PendingRequest *pr_tail;
117 * To whom are we talking to.
119 struct GNUNET_PeerIdentity sender;
122 * Current distance to the given peer.
127 * Current network the next hop peer is located in
129 enum GNUNET_ATS_Network_Type network;
132 * Does the transport service know about this session (and we thus
133 * need to call `session_end` when it is released?)
141 * Encapsulation of all of the state of the plugin.
148 struct GNUNET_TRANSPORT_PluginEnvironment *env;
151 * Hash map of sessions (active and inactive).
153 struct GNUNET_CONTAINER_MultiPeerMap *sessions;
156 * Copy of the handler array where the closures are
157 * set to this struct's instance.
159 struct GNUNET_SERVER_MessageHandler *handlers;
162 * Handle to the DV service
164 struct GNUNET_DV_ServiceHandle *dvh;
167 * Tokenizer for boxed messages.
169 struct GNUNET_SERVER_MessageStreamTokenizer *mst;
175 * Notify transport service about the change in distance.
177 * @param session session where the distance changed
180 notify_distance_change (struct Session *session)
182 struct Plugin *plugin = session->plugin;
183 struct GNUNET_ATS_Information ats;
185 if (GNUNET_YES != session->active)
187 ats.type = htonl ((uint32_t) GNUNET_ATS_QUALITY_NET_DISTANCE);
188 ats.value = htonl (session->distance);
189 plugin->env->update_address_metrics (plugin->env->cls,
198 * Function called by MST on each message from the box.
200 * @param cls closure with the `struct Plugin *`
201 * @param client identification of the client (with the 'struct Session')
202 * @param message the actual message
203 * @return #GNUNET_OK on success
208 const struct GNUNET_MessageHeader *message)
210 struct Plugin *plugin = cls;
211 struct Session *session = client;
212 struct GNUNET_ATS_Information ats;
214 ats.type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
215 ats.value = htonl (session->distance);
216 session->active = GNUNET_YES;
217 plugin->env->receive (plugin->env->cls,
221 plugin->env->update_address_metrics (plugin->env->cls,
222 &session->sender, NULL,
230 * Handler for messages received from the DV service.
232 * @param cls closure with the plugin
233 * @param sender sender of the message
234 * @param distance how far did the message travel
235 * @param msg actual message payload
238 handle_dv_message_received (void *cls,
239 const struct GNUNET_PeerIdentity *sender,
241 const struct GNUNET_MessageHeader *msg)
243 struct Plugin *plugin = cls;
244 struct GNUNET_ATS_Information ats;
245 struct Session *session;
247 LOG (GNUNET_ERROR_TYPE_DEBUG,
248 "Received `%s' message for peer `%s': new distance %u\n",
249 "DV_MESSAGE_RECEIVED",
250 GNUNET_i2s (sender), distance);
251 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
258 if (GNUNET_MESSAGE_TYPE_DV_BOX == ntohs (msg->type))
260 /* need to unbox using MST */
261 GNUNET_SERVER_mst_receive (plugin->mst,
263 (const char *) &msg[1],
264 ntohs (msg->size) - sizeof (struct GNUNET_MessageHeader),
269 ats.type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
270 ats.value = htonl (distance);
271 session->active = GNUNET_YES;
272 plugin->env->receive (plugin->env->cls, sender,
275 plugin->env->update_address_metrics (plugin->env->cls,
283 * Function called if DV starts to be able to talk to a peer.
285 * @param cls closure with `struct Plugin *`
286 * @param peer newly connected peer
287 * @param distance distance to the peer
288 * @param network the network the next hop is located in
291 handle_dv_connect (void *cls,
292 const struct GNUNET_PeerIdentity *peer,
294 enum GNUNET_ATS_Network_Type network)
296 struct Plugin *plugin = cls;
297 struct Session *session;
298 struct GNUNET_ATS_Information ats[2];
300 GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != network);
302 * This requires transport plugin to be linked to libgnunetats.
303 * If you remove it, also remove libgnunetats linkage from Makefile.am
305 LOG (GNUNET_ERROR_TYPE_DEBUG,
306 "Received `%s' message for peer `%s' with next hop in network %s\n",
309 GNUNET_ATS_print_network_type (network));
311 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
316 session->distance = distance;
317 notify_distance_change (session);
318 return; /* nothing to do */
321 session = GNUNET_new (struct Session);
322 session->sender = *peer;
323 session->plugin = plugin;
324 session->distance = distance;
325 session->network = network;
326 GNUNET_assert(GNUNET_YES ==
327 GNUNET_CONTAINER_multipeermap_put (plugin->sessions,
328 &session->sender, session,
329 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
331 LOG (GNUNET_ERROR_TYPE_DEBUG,
332 "Creating new DV session %p for peer `%s' at distance %u\n",
337 /* Notify transport and ats about new connection */
338 ats[0].type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
339 ats[0].value = htonl (distance);
340 ats[1].type = htonl (GNUNET_ATS_NETWORK_TYPE);
341 ats[1].value = htonl ((uint32_t) network);
342 session->active = GNUNET_YES;
343 plugin->env->session_start (plugin->env->cls, peer,
351 * Function called if DV distance to a peer is changed.
353 * @param cls closure with `struct Plugin *`
354 * @param peer connected peer
355 * @param distance new distance to the peer
356 * @param network network type used for the connection
359 handle_dv_distance_changed (void *cls,
360 const struct GNUNET_PeerIdentity *peer,
362 enum GNUNET_ATS_Network_Type network)
364 struct Plugin *plugin = cls;
365 struct Session *session;
367 GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != network);
368 LOG (GNUNET_ERROR_TYPE_DEBUG,
369 "Received `%s' message for peer `%s': new distance %u\n",
370 "DV_DISTANCE_CHANGED",
373 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
378 handle_dv_connect (plugin, peer, distance, network);
381 session->distance = distance;
382 notify_distance_change (session);
387 * Release session object and clean up associated resources.
389 * @param session session to clean up
392 free_session (struct Session *session)
394 struct Plugin *plugin = session->plugin;
395 struct PendingRequest *pr;
397 GNUNET_assert (GNUNET_YES ==
398 GNUNET_CONTAINER_multipeermap_remove (plugin->sessions,
402 LOG (GNUNET_ERROR_TYPE_DEBUG,
403 "Freeing session %p for peer `%s'\n",
405 GNUNET_i2s (&session->sender));
406 if (GNUNET_YES == session->active)
408 plugin->env->session_end (plugin->env->cls,
411 session->active = GNUNET_NO;
413 while (NULL != (pr = session->pr_head))
415 GNUNET_CONTAINER_DLL_remove (session->pr_head,
418 GNUNET_DV_send_cancel (pr->th);
420 if (NULL != pr->transmit_cont)
421 pr->transmit_cont (pr->transmit_cont_cls,
423 GNUNET_SYSERR, 0, 0);
426 GNUNET_free (session);
431 * Function called if DV is no longer able to talk to a peer.
433 * @param cls closure with `struct Plugin *`
434 * @param peer peer that disconnected
437 handle_dv_disconnect (void *cls,
438 const struct GNUNET_PeerIdentity *peer)
440 struct Plugin *plugin = cls;
441 struct Session *session;
443 LOG (GNUNET_ERROR_TYPE_DEBUG,
444 "Received `%s' message for peer `%s'\n",
447 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
450 return; /* nothing to do */
451 free_session (session);
456 * Function called once the delivery of a message has been successful.
457 * Clean up the pending request, and call continuations.
460 * @param ok #GNUNET_OK on success, #GNUNET_SYSERR on error
463 send_finished (void *cls,
466 struct PendingRequest *pr = cls;
467 struct Session *session = pr->session;
470 GNUNET_CONTAINER_DLL_remove (session->pr_head,
473 if (NULL != pr->transmit_cont)
474 pr->transmit_cont (pr->transmit_cont_cls,
482 * Function that can be used by the transport service to transmit
483 * a message using the plugin.
486 * @param session the session used
487 * @param priority how important is the message
488 * @param msgbuf the message to transmit
489 * @param msgbuf_size number of bytes in 'msgbuf'
490 * @param timeout when should we time out
491 * @param cont continuation to call once the message has
492 * been transmitted (or if the transport is ready
493 * for the next transmission call; or if the
494 * peer disconnected...)
495 * @param cont_cls closure for @a cont
496 * @return number of bytes used (on the physical network, with overheads);
497 * -1 on hard errors (i.e. address invalid); 0 is a legal value
498 * and does NOT mean that the message was not transmitted (DV)
501 dv_plugin_send (void *cls,
502 struct Session *session,
505 unsigned int priority,
506 struct GNUNET_TIME_Relative timeout,
507 GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls)
509 struct Plugin *plugin = cls;
510 struct PendingRequest *pr;
511 const struct GNUNET_MessageHeader *msg;
512 struct GNUNET_MessageHeader *box;
515 msg = (const struct GNUNET_MessageHeader *) msgbuf;
516 if (ntohs (msg->size) != msgbuf_size)
519 box = GNUNET_malloc (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
520 box->type = htons (GNUNET_MESSAGE_TYPE_DV_BOX);
521 box->size = htons (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
522 memcpy (&box[1], msgbuf, msgbuf_size);
525 pr = GNUNET_new (struct PendingRequest);
526 pr->transmit_cont = cont;
527 pr->transmit_cont_cls = cont_cls;
528 pr->session = session;
529 GNUNET_CONTAINER_DLL_insert_tail (session->pr_head,
533 pr->th = GNUNET_DV_send (plugin->dvh,
538 GNUNET_free_non_null (box);
544 * Function that can be used to force the plugin to disconnect
545 * from the given peer and cancel all previous transmissions
546 * (and their continuations).
548 * @param cls closure with the `struct Plugin *`
549 * @param target peer from which to disconnect
552 dv_plugin_disconnect_peer (void *cls,
553 const struct GNUNET_PeerIdentity *target)
555 struct Plugin *plugin = cls;
556 struct Session *session;
557 struct PendingRequest *pr;
559 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
562 return; /* nothing to do */
563 while (NULL != (pr = session->pr_head))
565 GNUNET_CONTAINER_DLL_remove (session->pr_head,
568 GNUNET_DV_send_cancel (pr->th);
570 if (NULL != pr->transmit_cont)
571 pr->transmit_cont (pr->transmit_cont_cls,
573 GNUNET_SYSERR, 0, 0);
576 session->active = GNUNET_NO;
581 * Function that can be used to force the plugin to disconnect
582 * from the given peer and cancel all previous transmissions
583 * (and their continuations).
585 * @param cls closure with the `struct Plugin *`
586 * @param session which session to disconnect
590 dv_plugin_disconnect_session (void *cls,
591 struct Session *session)
593 struct PendingRequest *pr;
595 while (NULL != (pr = session->pr_head))
597 GNUNET_CONTAINER_DLL_remove (session->pr_head,
600 GNUNET_DV_send_cancel (pr->th);
602 if (NULL != pr->transmit_cont)
603 pr->transmit_cont (pr->transmit_cont_cls,
605 GNUNET_SYSERR, 0, 0);
608 session->active = GNUNET_NO;
614 * Convert the transports address to a nice, human-readable
618 * @param type name of the transport that generated the address
619 * @param addr one of the addresses of the host, NULL for the last address
620 * the specific address format depends on the transport
621 * @param addrlen length of the address
622 * @param numeric should (IP) addresses be displayed in numeric form?
623 * @param timeout after how long should we give up?
624 * @param asc function to call on each string
625 * @param asc_cls closure for @a asc
628 dv_plugin_address_pretty_printer (void *cls, const char *type,
630 size_t addrlen, int numeric,
631 struct GNUNET_TIME_Relative timeout,
632 GNUNET_TRANSPORT_AddressStringCallback asc,
635 if ( (0 == addrlen) &&
636 (0 == strcmp (type, "dv")) )
643 * Convert the DV address to a pretty string.
646 * @param addr the (hopefully) DV address
647 * @param addrlen the length of the @a addr
648 * @return string representing the DV address
651 dv_plugin_address_to_string (void *cls,
657 GNUNET_break (0); /* malformed */
665 * Another peer has suggested an address for this peer and transport
666 * plugin. Check that this could be a valid address. This function
667 * is not expected to 'validate' the address in the sense of trying to
668 * connect to it but simply to see if the binary format is technically
669 * legal for establishing a connection to this peer (and make sure that
670 * the address really corresponds to our network connection/settings
671 * and not some potential man-in-the-middle).
674 * @param addr pointer to the address
675 * @param addrlen length of addr
676 * @return #GNUNET_OK if this is a plausible address for this peer
677 * and transport, #GNUNET_SYSERR if not
681 dv_plugin_check_address (void *cls,
686 return GNUNET_SYSERR;
692 * Create a new session to transmit data to the target
693 * This session will used to send data to this peer and the plugin will
694 * notify us by calling the env->session_end function
696 * @param cls the plugin
697 * @param address the address
698 * @return the session if the address is valid, NULL otherwise
700 static struct Session *
701 dv_get_session (void *cls,
702 const struct GNUNET_HELLO_Address *address)
704 struct Plugin *plugin = cls;
705 struct Session *session;
707 if (0 != address->address_length)
709 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
712 return NULL; /* not valid right now */
713 session->active = GNUNET_YES;
719 * Function called to convert a string address to
722 * @param cls closure ('struct Plugin*')
723 * @param addr string address
724 * @param addrlen length of the @a addr including \0 termination
725 * @param buf location to store the buffer
726 * If the function returns #GNUNET_SYSERR, its contents are undefined.
727 * @param added length of created address
728 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
731 dv_plugin_string_to_address (void *cls,
737 if ( (addrlen == 3) &&
738 (0 == strcmp ("dv", addr)) )
743 return GNUNET_SYSERR;
747 dv_plugin_update_session_timeout (void *cls,
748 const struct GNUNET_PeerIdentity *peer,
749 struct Session *session)
755 * Function to obtain the network type for a session
756 * FIXME: we should probably look at the network type
757 * used by the next hop here. Or find some other way
758 * to properly allow ATS-DV resource allocation.
760 * @param cls closure (`struct Plugin *`)
761 * @param session the session
762 * @return the network type
764 static enum GNUNET_ATS_Network_Type
765 dv_get_network (void *cls,
766 struct Session *session)
768 GNUNET_assert (NULL != session);
769 return session->network;
774 * Function that is called to get the keepalive factor.
775 * GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT is divided by this number to
776 * calculate the interval between keepalive packets.
778 * @param cls closure with the `struct Plugin`
779 * @return keepalive factor
782 dv_plugin_query_keepalive_factor (void *cls)
789 * Entry point for the plugin.
791 * @param cls closure with the plugin environment
795 libgnunet_plugin_transport_dv_init (void *cls)
797 struct GNUNET_TRANSPORT_PluginEnvironment *env = cls;
798 struct GNUNET_TRANSPORT_PluginFunctions *api;
799 struct Plugin *plugin;
801 plugin = GNUNET_new (struct Plugin);
803 plugin->sessions = GNUNET_CONTAINER_multipeermap_create (1024 * 8, GNUNET_YES);
804 plugin->mst = GNUNET_SERVER_mst_create (&unbox_cb,
806 plugin->dvh = GNUNET_DV_service_connect (env->cfg,
809 &handle_dv_distance_changed,
810 &handle_dv_disconnect,
811 &handle_dv_message_received);
812 if (NULL == plugin->dvh)
814 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
815 GNUNET_SERVER_mst_destroy (plugin->mst);
816 GNUNET_free (plugin);
819 api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions);
821 api->send = &dv_plugin_send;
822 api->disconnect_peer = &dv_plugin_disconnect_peer;
823 api->disconnect_session = &dv_plugin_disconnect_session;
824 api->address_pretty_printer = &dv_plugin_address_pretty_printer;
825 api->check_address = &dv_plugin_check_address;
826 api->address_to_string = &dv_plugin_address_to_string;
827 api->string_to_address = &dv_plugin_string_to_address;
828 api->query_keepalive_factor = &dv_plugin_query_keepalive_factor;
829 api->get_session = &dv_get_session;
830 api->get_network = &dv_get_network;
831 api->update_session_timeout = &dv_plugin_update_session_timeout;
837 * Function called to free a session.
841 * @param value session to free
842 * @return #GNUNET_OK (continue to iterate)
845 free_session_iterator (void *cls,
846 const struct GNUNET_PeerIdentity *key,
849 struct Session *session = value;
851 free_session (session);
857 * Exit point from the plugin.
859 * @param cls plugin API
863 libgnunet_plugin_transport_dv_done (void *cls)
865 struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
866 struct Plugin *plugin = api->cls;
868 GNUNET_DV_service_disconnect (plugin->dvh);
869 GNUNET_CONTAINER_multipeermap_iterate (plugin->sessions,
870 &free_session_iterator,
872 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
873 GNUNET_SERVER_mst_destroy (plugin->mst);
874 GNUNET_free (plugin);
879 /* end of plugin_transport_dv.c */