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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];
300 * This requires transport plugin to be linked to libgnunetats.
301 * If you remove it, also remove libgnunetats linkage from Makefile.am
303 LOG (GNUNET_ERROR_TYPE_DEBUG,
304 "Received `%s' message for peer `%s' with next hop in network %s\n",
307 GNUNET_ATS_print_network_type (network));
309 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
314 session->distance = distance;
315 notify_distance_change (session);
316 return; /* nothing to do */
319 session = GNUNET_new (struct Session);
320 session->sender = *peer;
321 session->plugin = plugin;
322 session->distance = distance;
323 session->network = network;
324 GNUNET_assert(GNUNET_YES ==
325 GNUNET_CONTAINER_multipeermap_put (plugin->sessions,
326 &session->sender, session,
327 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
329 LOG (GNUNET_ERROR_TYPE_DEBUG,
330 "Creating new session %p for peer `%s'\n",
334 /* Notify transport and ats about new connection */
335 ats[0].type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
336 ats[0].value = htonl (distance);
337 ats[1].type = htonl (GNUNET_ATS_NETWORK_TYPE);
338 ats[1].value = htonl (network);
339 session->active = GNUNET_YES;
340 plugin->env->session_start (plugin->env->cls, peer,
348 * Function called if DV distance to a peer is changed.
350 * @param cls closure with `struct Plugin *`
351 * @param peer connected peer
352 * @param distance new distance to the peer
355 handle_dv_distance_changed (void *cls,
356 const struct GNUNET_PeerIdentity *peer,
359 struct Plugin *plugin = cls;
360 struct Session *session;
362 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received `%s' message for peer `%s': new distance %u\n",
363 "DV_DISTANCE_CHANGED",
364 GNUNET_i2s (peer), distance);
366 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
372 handle_dv_connect (plugin, peer, distance, 0);
375 session->distance = distance;
376 notify_distance_change (session);
381 * Release session object and clean up associated resources.
383 * @param session session to clean up
386 free_session (struct Session *session)
388 struct Plugin *plugin = session->plugin;
389 struct PendingRequest *pr;
391 GNUNET_assert (GNUNET_YES ==
392 GNUNET_CONTAINER_multipeermap_remove (plugin->sessions,
396 LOG (GNUNET_ERROR_TYPE_DEBUG,
397 "Freeing session %p for peer `%s'\n",
399 GNUNET_i2s (&session->sender));
400 if (GNUNET_YES == session->active)
402 plugin->env->session_end (plugin->env->cls,
405 session->active = GNUNET_NO;
407 while (NULL != (pr = session->pr_head))
409 GNUNET_CONTAINER_DLL_remove (session->pr_head,
412 GNUNET_DV_send_cancel (pr->th);
414 if (NULL != pr->transmit_cont)
415 pr->transmit_cont (pr->transmit_cont_cls,
417 GNUNET_SYSERR, 0, 0);
420 GNUNET_free (session);
425 * Function called if DV is no longer able to talk to a peer.
427 * @param cls closure with `struct Plugin *`
428 * @param peer peer that disconnected
431 handle_dv_disconnect (void *cls,
432 const struct GNUNET_PeerIdentity *peer)
434 struct Plugin *plugin = cls;
435 struct Session *session;
437 LOG (GNUNET_ERROR_TYPE_DEBUG,
438 "Received `%s' message for peer `%s'\n",
441 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
444 return; /* nothing to do */
445 free_session (session);
450 * Function called once the delivery of a message has been successful.
451 * Clean up the pending request, and call continuations.
454 * @param ok #GNUNET_OK on success, #GNUNET_SYSERR on error
457 send_finished (void *cls,
460 struct PendingRequest *pr = cls;
461 struct Session *session = pr->session;
464 GNUNET_CONTAINER_DLL_remove (session->pr_head,
467 if (NULL != pr->transmit_cont)
468 pr->transmit_cont (pr->transmit_cont_cls,
476 * Function that can be used by the transport service to transmit
477 * a message using the plugin.
480 * @param session the session used
481 * @param priority how important is the message
482 * @param msgbuf the message to transmit
483 * @param msgbuf_size number of bytes in 'msgbuf'
484 * @param timeout when should we time out
485 * @param cont continuation to call once the message has
486 * been transmitted (or if the transport is ready
487 * for the next transmission call; or if the
488 * peer disconnected...)
489 * @param cont_cls closure for @a cont
490 * @return number of bytes used (on the physical network, with overheads);
491 * -1 on hard errors (i.e. address invalid); 0 is a legal value
492 * and does NOT mean that the message was not transmitted (DV)
495 dv_plugin_send (void *cls,
496 struct Session *session,
499 unsigned int priority,
500 struct GNUNET_TIME_Relative timeout,
501 GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls)
503 struct Plugin *plugin = cls;
504 struct PendingRequest *pr;
505 const struct GNUNET_MessageHeader *msg;
506 struct GNUNET_MessageHeader *box;
509 msg = (const struct GNUNET_MessageHeader *) msgbuf;
510 if (ntohs (msg->size) != msgbuf_size)
513 box = GNUNET_malloc (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
514 box->type = htons (GNUNET_MESSAGE_TYPE_DV_BOX);
515 box->size = htons (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
516 memcpy (&box[1], msgbuf, msgbuf_size);
519 pr = GNUNET_new (struct PendingRequest);
520 pr->transmit_cont = cont;
521 pr->transmit_cont_cls = cont_cls;
522 pr->session = session;
523 GNUNET_CONTAINER_DLL_insert_tail (session->pr_head,
527 pr->th = GNUNET_DV_send (plugin->dvh,
532 GNUNET_free_non_null (box);
538 * Function that can be used to force the plugin to disconnect
539 * from the given peer and cancel all previous transmissions
540 * (and their continuations).
542 * @param cls closure with the `struct Plugin *`
543 * @param target peer from which to disconnect
546 dv_plugin_disconnect (void *cls,
547 const struct GNUNET_PeerIdentity *target)
549 struct Plugin *plugin = cls;
550 struct Session *session;
551 struct PendingRequest *pr;
553 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
556 return; /* nothing to do */
557 while (NULL != (pr = session->pr_head))
559 GNUNET_CONTAINER_DLL_remove (session->pr_head,
562 GNUNET_DV_send_cancel (pr->th);
564 if (NULL != pr->transmit_cont)
565 pr->transmit_cont (pr->transmit_cont_cls,
567 GNUNET_SYSERR, 0, 0);
570 session->active = GNUNET_NO;
575 * Convert the transports address to a nice, human-readable
579 * @param type name of the transport that generated the address
580 * @param addr one of the addresses of the host, NULL for the last address
581 * the specific address format depends on the transport
582 * @param addrlen length of the address
583 * @param numeric should (IP) addresses be displayed in numeric form?
584 * @param timeout after how long should we give up?
585 * @param asc function to call on each string
586 * @param asc_cls closure for @a asc
589 dv_plugin_address_pretty_printer (void *cls, const char *type,
591 size_t addrlen, int numeric,
592 struct GNUNET_TIME_Relative timeout,
593 GNUNET_TRANSPORT_AddressStringCallback asc,
596 if ( (0 == addrlen) &&
597 (0 == strcmp (type, "dv")) )
604 * Convert the DV address to a pretty string.
607 * @param addr the (hopefully) DV address
608 * @param addrlen the length of the @a addr
609 * @return string representing the DV address
612 dv_plugin_address_to_string (void *cls,
618 GNUNET_break (0); /* malformed */
626 * Another peer has suggested an address for this peer and transport
627 * plugin. Check that this could be a valid address. This function
628 * is not expected to 'validate' the address in the sense of trying to
629 * connect to it but simply to see if the binary format is technically
630 * legal for establishing a connection to this peer (and make sure that
631 * the address really corresponds to our network connection/settings
632 * and not some potential man-in-the-middle).
635 * @param addr pointer to the address
636 * @param addrlen length of addr
637 * @return #GNUNET_OK if this is a plausible address for this peer
638 * and transport, #GNUNET_SYSERR if not
642 dv_plugin_check_address (void *cls,
647 return GNUNET_SYSERR;
653 * Create a new session to transmit data to the target
654 * This session will used to send data to this peer and the plugin will
655 * notify us by calling the env->session_end function
657 * @param cls the plugin
658 * @param address the address
659 * @return the session if the address is valid, NULL otherwise
661 static struct Session *
662 dv_get_session (void *cls,
663 const struct GNUNET_HELLO_Address *address)
665 struct Plugin *plugin = cls;
666 struct Session *session;
668 if (0 != address->address_length)
670 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
673 return NULL; /* not valid right now */
674 session->active = GNUNET_YES;
680 * Function called to convert a string address to
683 * @param cls closure ('struct Plugin*')
684 * @param addr string address
685 * @param addrlen length of the @a addr including \0 termination
686 * @param buf location to store the buffer
687 * If the function returns #GNUNET_SYSERR, its contents are undefined.
688 * @param added length of created address
689 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
692 dv_plugin_string_to_address (void *cls,
698 if ( (addrlen == 3) &&
699 (0 == strcmp ("dv", addr)) )
704 return GNUNET_SYSERR;
710 * Function to obtain the network type for a session
711 * FIXME: we should probably look at the network type
712 * used by the next hop here. Or find some other way
713 * to properly allow ATS-DV resource allocation.
715 * @param cls closure (`struct Plugin *`)
716 * @param session the session
717 * @return the network type
719 static enum GNUNET_ATS_Network_Type
720 dv_get_network (void *cls,
721 struct Session *session)
723 GNUNET_assert (NULL != session);
724 return session->network;
729 * Entry point for the plugin.
731 * @param cls closure with the plugin environment
735 libgnunet_plugin_transport_dv_init (void *cls)
737 struct GNUNET_TRANSPORT_PluginEnvironment *env = cls;
738 struct GNUNET_TRANSPORT_PluginFunctions *api;
739 struct Plugin *plugin;
741 plugin = GNUNET_new (struct Plugin);
743 plugin->sessions = GNUNET_CONTAINER_multipeermap_create (1024 * 8, GNUNET_YES);
744 plugin->mst = GNUNET_SERVER_mst_create (&unbox_cb,
746 plugin->dvh = GNUNET_DV_service_connect (env->cfg,
749 &handle_dv_distance_changed,
750 &handle_dv_disconnect,
751 &handle_dv_message_received);
752 if (NULL == plugin->dvh)
754 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
755 GNUNET_SERVER_mst_destroy (plugin->mst);
756 GNUNET_free (plugin);
759 api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions);
761 api->send = &dv_plugin_send;
762 api->disconnect = &dv_plugin_disconnect;
763 api->address_pretty_printer = &dv_plugin_address_pretty_printer;
764 api->check_address = &dv_plugin_check_address;
765 api->address_to_string = &dv_plugin_address_to_string;
766 api->string_to_address = &dv_plugin_string_to_address;
767 api->get_session = &dv_get_session;
768 api->get_network = &dv_get_network;
774 * Function called to free a session.
778 * @param value session to free
779 * @return GNUNET_OK (continue to iterate)
782 free_session_iterator (void *cls,
783 const struct GNUNET_PeerIdentity *key,
786 struct Session *session = value;
788 free_session (session);
794 * Exit point from the plugin.
796 * @param cls plugin API
800 libgnunet_plugin_transport_dv_done (void *cls)
802 struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
803 struct Plugin *plugin = api->cls;
805 GNUNET_DV_service_disconnect (plugin->dvh);
806 GNUNET_CONTAINER_multipeermap_iterate (plugin->sessions,
807 &free_session_iterator,
809 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
810 GNUNET_SERVER_mst_destroy (plugin->mst);
811 GNUNET_free (plugin);
816 /* end of plugin_transport_dv.c */