2 This file is part of GNUnet
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 @e 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;
88 * Number of bytes to transmit.
95 * Session handle for connections.
100 * Pointer to the global plugin struct.
102 struct Plugin *plugin;
105 * Head of pending requests.
107 struct PendingRequest *pr_head;
110 * Tail of pending requests.
112 struct PendingRequest *pr_tail;
114 struct GNUNET_HELLO_Address *address;
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,
190 session->address, session, &ats, 1);
195 * Function called by MST on each message from the box.
197 * @param cls closure with the `struct Plugin *`
198 * @param client identification of the client (with the 'struct Session')
199 * @param message the actual message
200 * @return #GNUNET_OK on success
205 const struct GNUNET_MessageHeader *message)
207 struct Plugin *plugin = cls;
208 struct Session *session = client;
209 struct GNUNET_ATS_Information ats;
211 ats.type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
212 ats.value = htonl (session->distance);
213 session->active = GNUNET_YES;
214 LOG (GNUNET_ERROR_TYPE_DEBUG,
215 "Delivering message of type %u with %u bytes from peer `%s'\n",
216 ntohs (message->type),
217 ntohs (message->size),
218 GNUNET_i2s (&session->sender));
220 plugin->env->receive (plugin->env->cls, session->address, session,
222 plugin->env->update_address_metrics (plugin->env->cls,
223 session->address, session, &ats, 1);
229 * Handler for messages received from the DV service.
231 * @param cls closure with the plugin
232 * @param sender sender of the message
233 * @param distance how far did the message travel
234 * @param msg actual message payload
237 handle_dv_message_received (void *cls,
238 const struct GNUNET_PeerIdentity *sender,
240 const struct GNUNET_MessageHeader *msg)
242 struct Plugin *plugin = cls;
243 struct GNUNET_ATS_Information ats;
244 struct Session *session;
246 LOG (GNUNET_ERROR_TYPE_DEBUG,
247 "Received DV_MESSAGE_RECEIVED message for peer `%s': new distance %u\n",
248 GNUNET_i2s (sender), distance);
249 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
256 if (GNUNET_MESSAGE_TYPE_DV_BOX == ntohs (msg->type))
258 /* need to unbox using MST */
259 LOG (GNUNET_ERROR_TYPE_DEBUG,
260 "Unboxing DV message using MST\n");
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 LOG (GNUNET_ERROR_TYPE_DEBUG,
273 "Delivering message of type %u with %u bytes from peer `%s'\n",
276 GNUNET_i2s (sender));
277 plugin->env->receive (plugin->env->cls, session->address, session, msg);
278 plugin->env->update_address_metrics (plugin->env->cls,
279 session->address, session, &ats, 1);
284 * Function called if DV starts to be able to talk to a peer.
286 * @param cls closure with `struct Plugin *`
287 * @param peer newly connected peer
288 * @param distance distance to the peer
289 * @param network the network the next hop is located in
292 handle_dv_connect (void *cls,
293 const struct GNUNET_PeerIdentity *peer,
295 enum GNUNET_ATS_Network_Type network)
297 struct Plugin *plugin = cls;
298 struct Session *session;
299 struct GNUNET_ATS_Information ats[2];
301 GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != network);
303 * This requires transport plugin to be linked to libgnunetats.
304 * If you remove it, also remove libgnunetats linkage from Makefile.am
306 LOG (GNUNET_ERROR_TYPE_DEBUG,
307 "Received `%s' message for peer `%s' with next hop in network %s\n",
310 GNUNET_ATS_print_network_type (network));
312 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
317 session->distance = distance;
318 notify_distance_change (session);
319 return; /* nothing to do */
322 session = GNUNET_new (struct Session);
323 session->address = GNUNET_HELLO_address_allocate (peer, PLUGIN_NAME,
324 NULL, 0, GNUNET_HELLO_ADDRESS_INFO_NONE);
325 session->sender = *peer;
326 session->plugin = plugin;
327 session->distance = distance;
328 session->network = network;
329 GNUNET_assert(GNUNET_YES ==
330 GNUNET_CONTAINER_multipeermap_put (plugin->sessions,
331 &session->sender, session,
332 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
334 LOG (GNUNET_ERROR_TYPE_DEBUG,
335 "Creating new DV session %p for peer `%s' at distance %u\n",
340 /* Notify transport and ats about new connection */
341 ats[0].type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
342 ats[0].value = htonl (distance);
343 ats[1].type = htonl (GNUNET_ATS_NETWORK_TYPE);
344 ats[1].value = htonl ((uint32_t) network);
345 session->active = GNUNET_YES;
346 plugin->env->session_start (plugin->env->cls, session->address,
352 * Function called if DV distance to a peer is changed.
354 * @param cls closure with `struct Plugin *`
355 * @param peer connected peer
356 * @param distance new distance to the peer
357 * @param network network type used for the connection
360 handle_dv_distance_changed (void *cls,
361 const struct GNUNET_PeerIdentity *peer,
363 enum GNUNET_ATS_Network_Type network)
365 struct Plugin *plugin = cls;
366 struct Session *session;
368 GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != network);
369 LOG (GNUNET_ERROR_TYPE_DEBUG,
370 "Received `%s' message for peer `%s': new distance %u\n",
371 "DV_DISTANCE_CHANGED",
374 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
379 handle_dv_connect (plugin, peer, distance, network);
382 session->distance = distance;
383 notify_distance_change (session);
388 * Release session object and clean up associated resources.
390 * @param session session to clean up
393 free_session (struct Session *session)
395 struct Plugin *plugin = session->plugin;
396 struct PendingRequest *pr;
398 GNUNET_assert (GNUNET_YES ==
399 GNUNET_CONTAINER_multipeermap_remove (plugin->sessions,
403 LOG (GNUNET_ERROR_TYPE_DEBUG,
404 "Freeing session %p for peer `%s'\n",
406 GNUNET_i2s (&session->sender));
407 if (GNUNET_YES == session->active)
409 plugin->env->session_end (plugin->env->cls,
412 session->active = GNUNET_NO;
414 while (NULL != (pr = session->pr_head))
416 GNUNET_CONTAINER_DLL_remove (session->pr_head,
419 GNUNET_DV_send_cancel (pr->th);
421 if (NULL != pr->transmit_cont)
422 pr->transmit_cont (pr->transmit_cont_cls,
428 GNUNET_HELLO_address_free (session->address);
429 GNUNET_free (session);
434 * Function called if DV is no longer able to talk to a peer.
436 * @param cls closure with `struct Plugin *`
437 * @param peer peer that disconnected
440 handle_dv_disconnect (void *cls,
441 const struct GNUNET_PeerIdentity *peer)
443 struct Plugin *plugin = cls;
444 struct Session *session;
446 LOG (GNUNET_ERROR_TYPE_DEBUG,
447 "Received `%s' message for peer `%s'\n",
450 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
453 return; /* nothing to do */
454 free_session (session);
459 * Function called once the delivery of a message has been successful.
460 * Clean up the pending request, and call continuations.
463 * @param ok #GNUNET_OK on success, #GNUNET_SYSERR on error
466 send_finished (void *cls,
469 struct PendingRequest *pr = cls;
470 struct Session *session = pr->session;
473 GNUNET_CONTAINER_DLL_remove (session->pr_head,
476 if (NULL != pr->transmit_cont)
477 pr->transmit_cont (pr->transmit_cont_cls,
486 * Function that can be used by the transport service to transmit
487 * a message using the plugin.
490 * @param session the session used
491 * @param priority how important is the message
492 * @param msgbuf the message to transmit
493 * @param msgbuf_size number of bytes in 'msgbuf'
494 * @param timeout when should we time out
495 * @param cont continuation to call once the message has
496 * been transmitted (or if the transport is ready
497 * for the next transmission call; or if the
498 * peer disconnected...)
499 * @param cont_cls closure for @a cont
500 * @return number of bytes used (on the physical network, with overheads);
501 * -1 on hard errors (i.e. address invalid); 0 is a legal value
502 * and does NOT mean that the message was not transmitted (DV)
505 dv_plugin_send (void *cls,
506 struct Session *session,
509 unsigned int priority,
510 struct GNUNET_TIME_Relative timeout,
511 GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls)
513 struct Plugin *plugin = cls;
514 struct PendingRequest *pr;
515 const struct GNUNET_MessageHeader *msg;
516 struct GNUNET_MessageHeader *box;
519 msg = (const struct GNUNET_MessageHeader *) msgbuf;
520 if (ntohs (msg->size) != msgbuf_size)
523 LOG (GNUNET_ERROR_TYPE_DEBUG,
524 "Boxing DV message\n");
525 box = GNUNET_malloc (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
526 box->type = htons (GNUNET_MESSAGE_TYPE_DV_BOX);
527 box->size = htons (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
528 memcpy (&box[1], msgbuf, msgbuf_size);
531 pr = GNUNET_new (struct PendingRequest);
532 pr->transmit_cont = cont;
533 pr->transmit_cont_cls = cont_cls;
534 pr->session = session;
535 pr->size = msgbuf_size;
536 GNUNET_CONTAINER_DLL_insert_tail (session->pr_head,
540 pr->th = GNUNET_DV_send (plugin->dvh,
545 GNUNET_free_non_null (box);
551 * Function that can be used to force the plugin to disconnect
552 * from the given peer and cancel all previous transmissions
553 * (and their continuations).
555 * @param cls closure with the `struct Plugin *`
556 * @param target peer from which to disconnect
559 dv_plugin_disconnect_peer (void *cls,
560 const struct GNUNET_PeerIdentity *target)
562 struct Plugin *plugin = cls;
563 struct Session *session;
564 struct PendingRequest *pr;
566 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
569 return; /* nothing to do */
570 while (NULL != (pr = session->pr_head))
572 GNUNET_CONTAINER_DLL_remove (session->pr_head,
575 GNUNET_DV_send_cancel (pr->th);
577 if (NULL != pr->transmit_cont)
578 pr->transmit_cont (pr->transmit_cont_cls,
584 session->active = GNUNET_NO;
589 * Function that can be used to force the plugin to disconnect
590 * from the given peer and cancel all previous transmissions
591 * (and their continuations).
593 * @param cls closure with the `struct Plugin *`
594 * @param session which session to disconnect
598 dv_plugin_disconnect_session (void *cls,
599 struct Session *session)
601 struct PendingRequest *pr;
603 while (NULL != (pr = session->pr_head))
605 GNUNET_CONTAINER_DLL_remove (session->pr_head,
608 GNUNET_DV_send_cancel (pr->th);
610 if (NULL != pr->transmit_cont)
611 pr->transmit_cont (pr->transmit_cont_cls,
617 session->active = GNUNET_NO;
623 * Convert the transports address to a nice, human-readable
627 * @param type name of the transport that generated the address
628 * @param addr one of the addresses of the host, NULL for the last address
629 * the specific address format depends on the transport
630 * @param addrlen length of the address
631 * @param numeric should (IP) addresses be displayed in numeric form?
632 * @param timeout after how long should we give up?
633 * @param asc function to call on each string
634 * @param asc_cls closure for @a asc
637 dv_plugin_address_pretty_printer (void *cls, const char *type,
639 size_t addrlen, int numeric,
640 struct GNUNET_TIME_Relative timeout,
641 GNUNET_TRANSPORT_AddressStringCallback asc,
644 if ( (0 == addrlen) &&
645 (0 == strcmp (type, "dv")) )
660 * Convert the DV address to a pretty string.
663 * @param addr the (hopefully) DV address
664 * @param addrlen the length of the @a addr
665 * @return string representing the DV address
668 dv_plugin_address_to_string (void *cls,
674 GNUNET_break (0); /* malformed */
682 * Another peer has suggested an address for this peer and transport
683 * plugin. Check that this could be a valid address. This function
684 * is not expected to 'validate' the address in the sense of trying to
685 * connect to it but simply to see if the binary format is technically
686 * legal for establishing a connection to this peer (and make sure that
687 * the address really corresponds to our network connection/settings
688 * and not some potential man-in-the-middle).
691 * @param addr pointer to the address
692 * @param addrlen length of @a addr
693 * @return #GNUNET_OK if this is a plausible address for this peer
694 * and transport, #GNUNET_SYSERR if not
698 dv_plugin_check_address (void *cls,
703 return GNUNET_SYSERR;
709 * Create a new session to transmit data to the target
710 * This session will used to send data to this peer and the plugin will
711 * notify us by calling the env->session_end function
713 * @param cls the plugin
714 * @param address the address
715 * @return the session if the address is valid, NULL otherwise
717 static struct Session *
718 dv_get_session (void *cls,
719 const struct GNUNET_HELLO_Address *address)
721 struct Plugin *plugin = cls;
722 struct Session *session;
724 if (0 != address->address_length)
726 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
729 return NULL; /* not valid right now */
730 session->active = GNUNET_YES;
736 * Function called to convert a string address to
739 * @param cls closure ('struct Plugin*')
740 * @param addr string address
741 * @param addrlen length of the @a addr including \0 termination
742 * @param buf location to store the buffer
743 * If the function returns #GNUNET_SYSERR, its contents are undefined.
744 * @param added length of created address
745 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
748 dv_plugin_string_to_address (void *cls,
754 if ( (addrlen == 3) &&
755 (0 == strcmp ("dv", addr)) )
760 return GNUNET_SYSERR;
765 * Function that will be called whenever the transport service wants to
766 * notify the plugin that a session is still active and in use and
767 * therefore the session timeout for this session has to be updated
769 * @param cls closure (`struct Plugin *`)
770 * @param peer which peer was the session for
771 * @param session which session is being updated
774 dv_plugin_update_session_timeout (void *cls,
775 const struct GNUNET_PeerIdentity *peer,
776 struct Session *session)
778 /* DV currently doesn't time out like "normal" plugins,
779 so it should be safe to do nothing, right?
780 (or should we add an internal timeout?) */
785 * Function to obtain the network type for a session
786 * FIXME: we should probably look at the network type
787 * used by the next hop here. Or find some other way
788 * to properly allow ATS-DV resource allocation.
790 * @param cls closure (`struct Plugin *`)
791 * @param session the session
792 * @return the network type
794 static enum GNUNET_ATS_Network_Type
795 dv_get_network (void *cls,
796 struct Session *session)
798 GNUNET_assert (NULL != session);
799 return session->network;
804 * Function that is called to get the keepalive factor.
805 * GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT is divided by this number to
806 * calculate the interval between keepalive packets.
808 * @param cls closure with the `struct Plugin`
809 * @return keepalive factor
812 dv_plugin_query_keepalive_factor (void *cls)
819 * Entry point for the plugin.
821 * @param cls closure with the plugin environment
825 libgnunet_plugin_transport_dv_init (void *cls)
827 struct GNUNET_TRANSPORT_PluginEnvironment *env = cls;
828 struct GNUNET_TRANSPORT_PluginFunctions *api;
829 struct Plugin *plugin;
831 plugin = GNUNET_new (struct Plugin);
833 plugin->sessions = GNUNET_CONTAINER_multipeermap_create (1024 * 8, GNUNET_YES);
834 plugin->mst = GNUNET_SERVER_mst_create (&unbox_cb,
836 plugin->dvh = GNUNET_DV_service_connect (env->cfg,
839 &handle_dv_distance_changed,
840 &handle_dv_disconnect,
841 &handle_dv_message_received);
842 if (NULL == plugin->dvh)
844 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
845 GNUNET_SERVER_mst_destroy (plugin->mst);
846 GNUNET_free (plugin);
849 api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions);
851 api->send = &dv_plugin_send;
852 api->disconnect_peer = &dv_plugin_disconnect_peer;
853 api->disconnect_session = &dv_plugin_disconnect_session;
854 api->address_pretty_printer = &dv_plugin_address_pretty_printer;
855 api->check_address = &dv_plugin_check_address;
856 api->address_to_string = &dv_plugin_address_to_string;
857 api->string_to_address = &dv_plugin_string_to_address;
858 api->query_keepalive_factor = &dv_plugin_query_keepalive_factor;
859 api->get_session = &dv_get_session;
860 api->get_network = &dv_get_network;
861 api->update_session_timeout = &dv_plugin_update_session_timeout;
867 * Function called to free a session.
871 * @param value session to free
872 * @return #GNUNET_OK (continue to iterate)
875 free_session_iterator (void *cls,
876 const struct GNUNET_PeerIdentity *key,
879 struct Session *session = value;
881 free_session (session);
887 * Exit point from the plugin.
889 * @param cls plugin API
893 libgnunet_plugin_transport_dv_done (void *cls)
895 struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
896 struct Plugin *plugin = api->cls;
898 GNUNET_DV_service_disconnect (plugin->dvh);
899 GNUNET_CONTAINER_multipeermap_iterate (plugin->sessions,
900 &free_session_iterator,
902 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
903 GNUNET_SERVER_mst_destroy (plugin->mst);
904 GNUNET_free (plugin);
909 /* end of plugin_transport_dv.c */