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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 ats.type = htonl ((uint32_t) GNUNET_ATS_QUALITY_NET_DISTANCE);
186 ats.value = htonl (session->distance);
187 plugin->env->update_address_metrics (plugin->env->cls,
196 * Function called by MST on each message from the box.
198 * @param cls closure with the 'struct Plugin'
199 * @param client identification of the client (with the 'struct Session')
200 * @param message the actual message
201 * @return GNUNET_OK on success
206 const struct GNUNET_MessageHeader *message)
208 struct Plugin *plugin = cls;
209 struct Session *session = client;
210 struct GNUNET_ATS_Information ats;
212 ats.type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
213 ats.value = htonl (session->distance);
214 session->active = GNUNET_YES;
215 plugin->env->receive (plugin->env->cls,
219 plugin->env->update_address_metrics (plugin->env->cls,
220 &session->sender, NULL, 0, session, &ats, 1);
226 * Handler for messages received from the DV service.
228 * @param cls closure with the plugin
229 * @param sender sender of the message
230 * @param distance how far did the message travel
231 * @param msg actual message payload
234 handle_dv_message_received (void *cls,
235 const struct GNUNET_PeerIdentity *sender,
237 const struct GNUNET_MessageHeader *msg)
239 struct Plugin *plugin = cls;
240 struct GNUNET_ATS_Information ats;
241 struct Session *session;
243 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received `%s' message for peer `%s': new distance %u\n",
244 "DV_MESSAGE_RECEIVED",
245 GNUNET_i2s (sender), distance);
248 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
255 if (GNUNET_MESSAGE_TYPE_DV_BOX == ntohs (msg->type))
257 /* need to unbox using MST */
258 GNUNET_SERVER_mst_receive (plugin->mst,
260 (const char *) &msg[1],
261 ntohs (msg->size) - sizeof (struct GNUNET_MessageHeader),
266 ats.type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
267 ats.value = htonl (distance);
268 session->active = GNUNET_YES;
269 plugin->env->receive (plugin->env->cls, sender,
272 plugin->env->update_address_metrics (plugin->env->cls,
273 sender, "", 0, session, &ats, 1);
278 * Function called if DV starts to be able to talk to a peer.
280 * @param cls closure with 'struct Plugin'
281 * @param peer newly connected peer
282 * @param distance distance to the peer
283 * @param network the network the next hop is located in
286 handle_dv_connect (void *cls,
287 const struct GNUNET_PeerIdentity *peer,
288 uint32_t distance, uint32_t network)
290 struct Plugin *plugin = cls;
291 struct Session *session;
292 struct GNUNET_ATS_Information ats[2];
295 * This requires transport plugin to be linked to libgnunetats.
296 * If you remove it, also remove libgnunetats linkage from Makefile.am
298 LOG (GNUNET_ERROR_TYPE_DEBUG,
299 "Received `%s' message for peer `%s' with next hop in network %s \n",
302 GNUNET_ATS_print_network_type (network));
304 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
309 session->distance = distance;
310 if (GNUNET_YES == session->active)
311 notify_distance_change (session);
312 return; /* nothing to do */
314 session = GNUNET_new (struct Session);
315 session->sender = *peer;
316 session->distance = distance;
317 session->network = network;
318 GNUNET_assert (GNUNET_YES ==
319 GNUNET_CONTAINER_multipeermap_put (plugin->sessions,
322 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
324 /* Notify transport and ats about new connection */
325 ats[0].type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
326 ats[0].value = htonl (distance);
327 ats[0].type = htonl (GNUNET_ATS_NETWORK_TYPE);
328 ats[0].value = htonl (network);
329 plugin->env->session_start (plugin->env->cls, peer, PLUGIN_NAME, NULL, 0,
335 * Function called if DV distance to a peer is changed.
337 * @param cls closure with 'struct Plugin'
338 * @param peer connected peer
339 * @param distance new distance to the peer
342 handle_dv_distance_changed (void *cls,
343 const struct GNUNET_PeerIdentity *peer,
346 struct Plugin *plugin = cls;
347 struct Session *session;
349 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received `%s' message for peer `%s': new distance %u\n",
350 "DV_DISTANCE_CHANGED",
351 GNUNET_i2s (peer), distance);
353 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
359 handle_dv_connect (plugin, peer, distance, 0);
362 session->distance = distance;
363 if (GNUNET_YES == session->active)
364 notify_distance_change (session);
369 * Release session object and clean up associated resources.
371 * @param session session to clean up
374 free_session (struct Session *session)
376 struct Plugin *plugin = session->plugin;
377 struct PendingRequest *pr;
379 GNUNET_assert (GNUNET_YES ==
380 GNUNET_CONTAINER_multipeermap_remove (plugin->sessions,
383 if (GNUNET_YES == session->active)
384 plugin->env->session_end (plugin->env->cls,
387 while (NULL != (pr = session->pr_head))
389 GNUNET_CONTAINER_DLL_remove (session->pr_head,
392 GNUNET_DV_send_cancel (pr->th);
394 if (NULL != pr->transmit_cont)
395 pr->transmit_cont (pr->transmit_cont_cls,
397 GNUNET_SYSERR, 0, 0);
400 GNUNET_free (session);
405 * Function called if DV is no longer able to talk to a peer.
407 * @param cls closure with 'struct Plugin'
408 * @param peer peer that disconnected
411 handle_dv_disconnect (void *cls,
412 const struct GNUNET_PeerIdentity *peer)
414 struct Plugin *plugin = cls;
415 struct Session *session;
417 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received `%s' message for peer `%s'\n",
421 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
424 return; /* nothing to do */
426 free_session (session);
431 * Function called once the delivery of a message has been successful.
432 * Clean up the pending request, and call continuations.
435 * @param ok GNUNET_OK on success, GNUNET_SYSERR on error
438 send_finished (void *cls,
441 struct PendingRequest *pr = cls;
442 struct Session *session = pr->session;
445 GNUNET_CONTAINER_DLL_remove (session->pr_head,
448 if (NULL != pr->transmit_cont)
449 pr->transmit_cont (pr->transmit_cont_cls,
457 * Function that can be used by the transport service to transmit
458 * a message using the plugin.
461 * @param session the session used
462 * @param priority how important is the message
463 * @param msgbuf the message to transmit
464 * @param msgbuf_size number of bytes in 'msgbuf'
465 * @param timeout when should we time out
466 * @param cont continuation to call once the message has
467 * been transmitted (or if the transport is ready
468 * for the next transmission call; or if the
469 * peer disconnected...)
470 * @param cont_cls closure for cont
471 * @return number of bytes used (on the physical network, with overheads);
472 * -1 on hard errors (i.e. address invalid); 0 is a legal value
473 * and does NOT mean that the message was not transmitted (DV)
476 dv_plugin_send (void *cls,
477 struct Session *session,
478 const char *msgbuf, size_t msgbuf_size, unsigned int priority,
479 struct GNUNET_TIME_Relative timeout,
480 GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls)
482 struct PendingRequest *pr;
483 const struct GNUNET_MessageHeader *msg;
484 struct GNUNET_MessageHeader *box;
487 msg = (const struct GNUNET_MessageHeader *) msgbuf;
488 if (ntohs (msg->size) != msgbuf_size)
491 box = GNUNET_malloc (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
492 box->type = htons (GNUNET_MESSAGE_TYPE_DV_BOX);
493 box->size = htons (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
494 memcpy (&box[1], msgbuf, msgbuf_size);
497 pr = GNUNET_new (struct PendingRequest);
498 pr->transmit_cont = cont;
499 pr->transmit_cont_cls = cont_cls;
500 pr->session = session;
501 GNUNET_CONTAINER_DLL_insert_tail (session->pr_head,
504 pr->th = GNUNET_DV_send (session->plugin->dvh,
509 GNUNET_free_non_null (box);
515 * Function that can be used to force the plugin to disconnect
516 * from the given peer and cancel all previous transmissions
517 * (and their continuations).
520 * @param target peer from which to disconnect
523 dv_plugin_disconnect (void *cls, const struct GNUNET_PeerIdentity *target)
525 struct Plugin *plugin = cls;
526 struct Session *session;
527 struct PendingRequest *pr;
529 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
532 return; /* nothing to do */
533 while (NULL != (pr = session->pr_head))
535 GNUNET_CONTAINER_DLL_remove (session->pr_head,
538 GNUNET_DV_send_cancel (pr->th);
540 if (NULL != pr->transmit_cont)
541 pr->transmit_cont (pr->transmit_cont_cls,
543 GNUNET_SYSERR, 0, 0);
546 session->active = GNUNET_NO;
551 * Convert the transports address to a nice, human-readable
555 * @param type name of the transport that generated the address
556 * @param addr one of the addresses of the host, NULL for the last address
557 * the specific address format depends on the transport
558 * @param addrlen length of the address
559 * @param numeric should (IP) addresses be displayed in numeric form?
560 * @param timeout after how long should we give up?
561 * @param asc function to call on each string
562 * @param asc_cls closure for asc
565 dv_plugin_address_pretty_printer (void *cls, const char *type, const void *addr,
566 size_t addrlen, int numeric,
567 struct GNUNET_TIME_Relative timeout,
568 GNUNET_TRANSPORT_AddressStringCallback asc,
571 if ( (0 == addrlen) &&
572 (0 == strcmp (type, "dv")) )
579 * Convert the DV address to a pretty string.
582 * @param addr the (hopefully) DV address
583 * @param addrlen the length of the address
585 * @return string representing the DV address
588 dv_plugin_address_to_string (void *cls, const void *addr, size_t addrlen)
592 GNUNET_break (0); /* malformed */
600 * Another peer has suggested an address for this peer and transport
601 * plugin. Check that this could be a valid address. This function
602 * is not expected to 'validate' the address in the sense of trying to
603 * connect to it but simply to see if the binary format is technically
604 * legal for establishing a connection to this peer (and make sure that
605 * the address really corresponds to our network connection/settings
606 * and not some potential man-in-the-middle).
609 * @param addr pointer to the address
610 * @param addrlen length of addr
611 * @return GNUNET_OK if this is a plausible address for this peer
612 * and transport, GNUNET_SYSERR if not
616 dv_plugin_check_address (void *cls, const void *addr, size_t addrlen)
619 return GNUNET_SYSERR;
625 * Create a new session to transmit data to the target
626 * This session will used to send data to this peer and the plugin will
627 * notify us by calling the env->session_end function
629 * @param cls the plugin
630 * @param address the address
631 * @return the session if the address is valid, NULL otherwise
633 static struct Session *
634 dv_get_session (void *cls,
635 const struct GNUNET_HELLO_Address *address)
637 struct Plugin *plugin = cls;
638 struct Session *session;
640 if (0 != address->address_length)
642 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
645 return NULL; /* not valid right now */
646 session->active = GNUNET_YES;
652 * Function called to convert a string address to
655 * @param cls closure ('struct Plugin*')
656 * @param addr string address
657 * @param addrlen length of the address including \0 termination
658 * @param buf location to store the buffer
659 * If the function returns GNUNET_SYSERR, its contents are undefined.
660 * @param added length of created address
661 * @return GNUNET_OK on success, GNUNET_SYSERR on failure
664 dv_plugin_string_to_address (void *cls,
670 if ( (addrlen == 3) &&
671 (0 == strcmp ("dv", addr)) )
676 return GNUNET_SYSERR;
682 * Function to obtain the network type for a session
683 * FIXME: we should probably look at the network type
684 * used by the next hop here. Or find some other way
685 * to properly allow ATS-DV resource allocation.
687 * @param cls closure ('struct Plugin*')
688 * @param session the session
689 * @return the network type
691 static enum GNUNET_ATS_Network_Type
692 dv_get_network (void *cls,
693 struct Session *session)
695 GNUNET_assert (NULL != session);
696 return session->network;
701 * Entry point for the plugin.
703 * @param cls closure with the plugin environment
707 libgnunet_plugin_transport_dv_init (void *cls)
709 struct GNUNET_TRANSPORT_PluginEnvironment *env = cls;
710 struct GNUNET_TRANSPORT_PluginFunctions *api;
711 struct Plugin *plugin;
713 plugin = GNUNET_new (struct Plugin);
715 plugin->sessions = GNUNET_CONTAINER_multipeermap_create (1024 * 8, GNUNET_YES);
716 plugin->mst = GNUNET_SERVER_mst_create (&unbox_cb,
718 plugin->dvh = GNUNET_DV_service_connect (env->cfg,
721 &handle_dv_distance_changed,
722 &handle_dv_disconnect,
723 &handle_dv_message_received);
724 if (NULL == plugin->dvh)
726 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
727 GNUNET_SERVER_mst_destroy (plugin->mst);
728 GNUNET_free (plugin);
731 api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions);
733 api->send = &dv_plugin_send;
734 api->disconnect = &dv_plugin_disconnect;
735 api->address_pretty_printer = &dv_plugin_address_pretty_printer;
736 api->check_address = &dv_plugin_check_address;
737 api->address_to_string = &dv_plugin_address_to_string;
738 api->string_to_address = &dv_plugin_string_to_address;
739 api->get_session = &dv_get_session;
740 api->get_network = &dv_get_network;
746 * Function called to free a session.
750 * @param value session to free
751 * @return GNUNET_OK (continue to iterate)
754 free_session_iterator (void *cls,
755 const struct GNUNET_PeerIdentity *key,
758 struct Session *session = value;
760 free_session (session);
766 * Exit point from the plugin.
768 * @param cls plugin API
772 libgnunet_plugin_transport_dv_done (void *cls)
774 struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
775 struct Plugin *plugin = api->cls;
777 GNUNET_DV_service_disconnect (plugin->dvh);
778 GNUNET_CONTAINER_multipeermap_iterate (plugin->sessions,
779 &free_session_iterator,
781 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
782 GNUNET_SERVER_mst_destroy (plugin->mst);
783 GNUNET_free (plugin);
788 /* end of plugin_transport_dv.c */