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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
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,
293 uint32_t distance, uint32_t network)
295 struct Plugin *plugin = cls;
296 struct Session *session;
297 struct GNUNET_ATS_Information ats[2];
299 GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != network);
301 * This requires transport plugin to be linked to libgnunetats.
302 * If you remove it, also remove libgnunetats linkage from Makefile.am
304 LOG (GNUNET_ERROR_TYPE_DEBUG,
305 "Received `%s' message for peer `%s' with next hop in network %s\n",
308 GNUNET_ATS_print_network_type (network));
310 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
315 session->distance = distance;
316 notify_distance_change (session);
317 return; /* nothing to do */
320 session = GNUNET_new (struct Session);
321 session->sender = *peer;
322 session->plugin = plugin;
323 session->distance = distance;
324 session->network = network;
325 GNUNET_assert(GNUNET_YES ==
326 GNUNET_CONTAINER_multipeermap_put (plugin->sessions,
327 &session->sender, session,
328 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
330 LOG (GNUNET_ERROR_TYPE_DEBUG,
331 "Creating new session %p for peer `%s'\n",
335 /* Notify transport and ats about new connection */
336 ats[0].type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
337 ats[0].value = htonl (distance);
338 ats[1].type = htonl (GNUNET_ATS_NETWORK_TYPE);
339 ats[1].value = htonl (network);
340 session->active = GNUNET_YES;
341 plugin->env->session_start (plugin->env->cls, peer,
349 * Function called if DV distance to a peer is changed.
351 * @param cls closure with `struct Plugin *`
352 * @param peer connected peer
353 * @param distance new distance to the peer
354 * @param network network type used for the connection
357 handle_dv_distance_changed (void *cls,
358 const struct GNUNET_PeerIdentity *peer,
362 struct Plugin *plugin = cls;
363 struct Session *session;
365 LOG (GNUNET_ERROR_TYPE_DEBUG,
366 "Received `%s' message for peer `%s': new distance %u\n",
367 "DV_DISTANCE_CHANGED",
370 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
375 handle_dv_connect (plugin, peer, distance, network);
378 session->distance = distance;
379 notify_distance_change (session);
384 * Release session object and clean up associated resources.
386 * @param session session to clean up
389 free_session (struct Session *session)
391 struct Plugin *plugin = session->plugin;
392 struct PendingRequest *pr;
394 GNUNET_assert (GNUNET_YES ==
395 GNUNET_CONTAINER_multipeermap_remove (plugin->sessions,
399 LOG (GNUNET_ERROR_TYPE_DEBUG,
400 "Freeing session %p for peer `%s'\n",
402 GNUNET_i2s (&session->sender));
403 if (GNUNET_YES == session->active)
405 plugin->env->session_end (plugin->env->cls,
408 session->active = GNUNET_NO;
410 while (NULL != (pr = session->pr_head))
412 GNUNET_CONTAINER_DLL_remove (session->pr_head,
415 GNUNET_DV_send_cancel (pr->th);
417 if (NULL != pr->transmit_cont)
418 pr->transmit_cont (pr->transmit_cont_cls,
420 GNUNET_SYSERR, 0, 0);
423 GNUNET_free (session);
428 * Function called if DV is no longer able to talk to a peer.
430 * @param cls closure with `struct Plugin *`
431 * @param peer peer that disconnected
434 handle_dv_disconnect (void *cls,
435 const struct GNUNET_PeerIdentity *peer)
437 struct Plugin *plugin = cls;
438 struct Session *session;
440 LOG (GNUNET_ERROR_TYPE_DEBUG,
441 "Received `%s' message for peer `%s'\n",
444 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
447 return; /* nothing to do */
448 free_session (session);
453 * Function called once the delivery of a message has been successful.
454 * Clean up the pending request, and call continuations.
457 * @param ok #GNUNET_OK on success, #GNUNET_SYSERR on error
460 send_finished (void *cls,
463 struct PendingRequest *pr = cls;
464 struct Session *session = pr->session;
467 GNUNET_CONTAINER_DLL_remove (session->pr_head,
470 if (NULL != pr->transmit_cont)
471 pr->transmit_cont (pr->transmit_cont_cls,
479 * Function that can be used by the transport service to transmit
480 * a message using the plugin.
483 * @param session the session used
484 * @param priority how important is the message
485 * @param msgbuf the message to transmit
486 * @param msgbuf_size number of bytes in 'msgbuf'
487 * @param timeout when should we time out
488 * @param cont continuation to call once the message has
489 * been transmitted (or if the transport is ready
490 * for the next transmission call; or if the
491 * peer disconnected...)
492 * @param cont_cls closure for @a cont
493 * @return number of bytes used (on the physical network, with overheads);
494 * -1 on hard errors (i.e. address invalid); 0 is a legal value
495 * and does NOT mean that the message was not transmitted (DV)
498 dv_plugin_send (void *cls,
499 struct Session *session,
502 unsigned int priority,
503 struct GNUNET_TIME_Relative timeout,
504 GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls)
506 struct Plugin *plugin = cls;
507 struct PendingRequest *pr;
508 const struct GNUNET_MessageHeader *msg;
509 struct GNUNET_MessageHeader *box;
512 msg = (const struct GNUNET_MessageHeader *) msgbuf;
513 if (ntohs (msg->size) != msgbuf_size)
516 box = GNUNET_malloc (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
517 box->type = htons (GNUNET_MESSAGE_TYPE_DV_BOX);
518 box->size = htons (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
519 memcpy (&box[1], msgbuf, msgbuf_size);
522 pr = GNUNET_new (struct PendingRequest);
523 pr->transmit_cont = cont;
524 pr->transmit_cont_cls = cont_cls;
525 pr->session = session;
526 GNUNET_CONTAINER_DLL_insert_tail (session->pr_head,
530 pr->th = GNUNET_DV_send (plugin->dvh,
535 GNUNET_free_non_null (box);
541 * Function that can be used to force the plugin to disconnect
542 * from the given peer and cancel all previous transmissions
543 * (and their continuations).
545 * @param cls closure with the `struct Plugin *`
546 * @param target peer from which to disconnect
549 dv_plugin_disconnect_peer (void *cls,
550 const struct GNUNET_PeerIdentity *target)
552 struct Plugin *plugin = cls;
553 struct Session *session;
554 struct PendingRequest *pr;
556 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
559 return; /* nothing to do */
560 while (NULL != (pr = session->pr_head))
562 GNUNET_CONTAINER_DLL_remove (session->pr_head,
565 GNUNET_DV_send_cancel (pr->th);
567 if (NULL != pr->transmit_cont)
568 pr->transmit_cont (pr->transmit_cont_cls,
570 GNUNET_SYSERR, 0, 0);
573 session->active = GNUNET_NO;
578 * Function that can be used to force the plugin to disconnect
579 * from the given peer and cancel all previous transmissions
580 * (and their continuations).
582 * @param cls closure with the `struct Plugin *`
583 * @param session which session to disconnect
587 dv_plugin_disconnect_session (void *cls,
588 struct Session *session)
590 struct PendingRequest *pr;
592 while (NULL != (pr = session->pr_head))
594 GNUNET_CONTAINER_DLL_remove (session->pr_head,
597 GNUNET_DV_send_cancel (pr->th);
599 if (NULL != pr->transmit_cont)
600 pr->transmit_cont (pr->transmit_cont_cls,
602 GNUNET_SYSERR, 0, 0);
605 session->active = GNUNET_NO;
611 * Convert the transports address to a nice, human-readable
615 * @param type name of the transport that generated the address
616 * @param addr one of the addresses of the host, NULL for the last address
617 * the specific address format depends on the transport
618 * @param addrlen length of the address
619 * @param numeric should (IP) addresses be displayed in numeric form?
620 * @param timeout after how long should we give up?
621 * @param asc function to call on each string
622 * @param asc_cls closure for @a asc
625 dv_plugin_address_pretty_printer (void *cls, const char *type,
627 size_t addrlen, int numeric,
628 struct GNUNET_TIME_Relative timeout,
629 GNUNET_TRANSPORT_AddressStringCallback asc,
632 if ( (0 == addrlen) &&
633 (0 == strcmp (type, "dv")) )
640 * Convert the DV address to a pretty string.
643 * @param addr the (hopefully) DV address
644 * @param addrlen the length of the @a addr
645 * @return string representing the DV address
648 dv_plugin_address_to_string (void *cls,
654 GNUNET_break (0); /* malformed */
662 * Another peer has suggested an address for this peer and transport
663 * plugin. Check that this could be a valid address. This function
664 * is not expected to 'validate' the address in the sense of trying to
665 * connect to it but simply to see if the binary format is technically
666 * legal for establishing a connection to this peer (and make sure that
667 * the address really corresponds to our network connection/settings
668 * and not some potential man-in-the-middle).
671 * @param addr pointer to the address
672 * @param addrlen length of addr
673 * @return #GNUNET_OK if this is a plausible address for this peer
674 * and transport, #GNUNET_SYSERR if not
678 dv_plugin_check_address (void *cls,
683 return GNUNET_SYSERR;
689 * Create a new session to transmit data to the target
690 * This session will used to send data to this peer and the plugin will
691 * notify us by calling the env->session_end function
693 * @param cls the plugin
694 * @param address the address
695 * @return the session if the address is valid, NULL otherwise
697 static struct Session *
698 dv_get_session (void *cls,
699 const struct GNUNET_HELLO_Address *address)
701 struct Plugin *plugin = cls;
702 struct Session *session;
704 if (0 != address->address_length)
706 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
709 return NULL; /* not valid right now */
710 session->active = GNUNET_YES;
716 * Function called to convert a string address to
719 * @param cls closure ('struct Plugin*')
720 * @param addr string address
721 * @param addrlen length of the @a addr including \0 termination
722 * @param buf location to store the buffer
723 * If the function returns #GNUNET_SYSERR, its contents are undefined.
724 * @param added length of created address
725 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
728 dv_plugin_string_to_address (void *cls,
734 if ( (addrlen == 3) &&
735 (0 == strcmp ("dv", addr)) )
740 return GNUNET_SYSERR;
746 * Function to obtain the network type for a session
747 * FIXME: we should probably look at the network type
748 * used by the next hop here. Or find some other way
749 * to properly allow ATS-DV resource allocation.
751 * @param cls closure (`struct Plugin *`)
752 * @param session the session
753 * @return the network type
755 static enum GNUNET_ATS_Network_Type
756 dv_get_network (void *cls,
757 struct Session *session)
759 GNUNET_assert (NULL != session);
760 return session->network;
765 * Entry point for the plugin.
767 * @param cls closure with the plugin environment
771 libgnunet_plugin_transport_dv_init (void *cls)
773 struct GNUNET_TRANSPORT_PluginEnvironment *env = cls;
774 struct GNUNET_TRANSPORT_PluginFunctions *api;
775 struct Plugin *plugin;
777 plugin = GNUNET_new (struct Plugin);
779 plugin->sessions = GNUNET_CONTAINER_multipeermap_create (1024 * 8, GNUNET_YES);
780 plugin->mst = GNUNET_SERVER_mst_create (&unbox_cb,
782 plugin->dvh = GNUNET_DV_service_connect (env->cfg,
785 &handle_dv_distance_changed,
786 &handle_dv_disconnect,
787 &handle_dv_message_received);
788 if (NULL == plugin->dvh)
790 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
791 GNUNET_SERVER_mst_destroy (plugin->mst);
792 GNUNET_free (plugin);
795 api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions);
797 api->send = &dv_plugin_send;
798 api->disconnect_peer = &dv_plugin_disconnect_peer;
799 api->disconnect_session = &dv_plugin_disconnect_session;
800 api->address_pretty_printer = &dv_plugin_address_pretty_printer;
801 api->check_address = &dv_plugin_check_address;
802 api->address_to_string = &dv_plugin_address_to_string;
803 api->string_to_address = &dv_plugin_string_to_address;
804 api->get_session = &dv_get_session;
805 api->get_network = &dv_get_network;
811 * Function called to free a session.
815 * @param value session to free
816 * @return #GNUNET_OK (continue to iterate)
819 free_session_iterator (void *cls,
820 const struct GNUNET_PeerIdentity *key,
823 struct Session *session = value;
825 free_session (session);
831 * Exit point from the plugin.
833 * @param cls plugin API
837 libgnunet_plugin_transport_dv_done (void *cls)
839 struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
840 struct Plugin *plugin = api->cls;
842 GNUNET_DV_service_disconnect (plugin->dvh);
843 GNUNET_CONTAINER_multipeermap_iterate (plugin->sessions,
844 &free_session_iterator,
846 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
847 GNUNET_SERVER_mst_destroy (plugin->mst);
848 GNUNET_free (plugin);
853 /* end of plugin_transport_dv.c */