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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 */
315 session = GNUNET_new (struct Session);
316 session->sender = *peer;
317 session->distance = distance;
318 session->network = network;
320 GNUNET_YES == GNUNET_CONTAINER_multipeermap_put (plugin->sessions,
321 &session->sender, session,
322 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
324 LOG (GNUNET_ERROR_TYPE_DEBUG,
325 "Creating new session %p for peer `%s'\n",
329 /* Notify transport and ats about new connection */
330 ats[0].type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
331 ats[0].value = htonl (distance);
332 ats[1].type = htonl (GNUNET_ATS_NETWORK_TYPE);
333 ats[1].value = htonl (network);
334 plugin->env->session_start (plugin->env->cls, peer, PLUGIN_NAME, NULL, 0,
340 * Function called if DV distance to a peer is changed.
342 * @param cls closure with 'struct Plugin'
343 * @param peer connected peer
344 * @param distance new distance to the peer
347 handle_dv_distance_changed (void *cls,
348 const struct GNUNET_PeerIdentity *peer,
351 struct Plugin *plugin = cls;
352 struct Session *session;
354 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received `%s' message for peer `%s': new distance %u\n",
355 "DV_DISTANCE_CHANGED",
356 GNUNET_i2s (peer), distance);
358 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
364 handle_dv_connect (plugin, peer, distance, 0);
367 session->distance = distance;
368 if (GNUNET_YES == session->active)
369 notify_distance_change (session);
374 * Release session object and clean up associated resources.
376 * @param session session to clean up
379 free_session (struct Session *session)
381 struct Plugin *plugin = session->plugin;
382 struct PendingRequest *pr;
384 GNUNET_assert (GNUNET_YES ==
385 GNUNET_CONTAINER_multipeermap_remove (plugin->sessions,
389 LOG (GNUNET_ERROR_TYPE_DEBUG,
390 "Freeing session %p for peer `%s'\n",
392 GNUNET_i2s (&session->sender));
394 if (GNUNET_YES == session->active)
395 plugin->env->session_end (plugin->env->cls,
398 while (NULL != (pr = session->pr_head))
400 GNUNET_CONTAINER_DLL_remove (session->pr_head,
403 GNUNET_DV_send_cancel (pr->th);
405 if (NULL != pr->transmit_cont)
406 pr->transmit_cont (pr->transmit_cont_cls,
408 GNUNET_SYSERR, 0, 0);
411 GNUNET_free (session);
416 * Function called if DV is no longer able to talk to a peer.
418 * @param cls closure with 'struct Plugin'
419 * @param peer peer that disconnected
422 handle_dv_disconnect (void *cls,
423 const struct GNUNET_PeerIdentity *peer)
425 struct Plugin *plugin = cls;
426 struct Session *session;
428 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received `%s' message for peer `%s'\n",
432 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
435 return; /* nothing to do */
437 free_session (session);
442 * Function called once the delivery of a message has been successful.
443 * Clean up the pending request, and call continuations.
446 * @param ok GNUNET_OK on success, GNUNET_SYSERR on error
449 send_finished (void *cls,
452 struct PendingRequest *pr = cls;
453 struct Session *session = pr->session;
456 GNUNET_CONTAINER_DLL_remove (session->pr_head,
459 if (NULL != pr->transmit_cont)
460 pr->transmit_cont (pr->transmit_cont_cls,
468 * Function that can be used by the transport service to transmit
469 * a message using the plugin.
472 * @param session the session used
473 * @param priority how important is the message
474 * @param msgbuf the message to transmit
475 * @param msgbuf_size number of bytes in 'msgbuf'
476 * @param timeout when should we time out
477 * @param cont continuation to call once the message has
478 * been transmitted (or if the transport is ready
479 * for the next transmission call; or if the
480 * peer disconnected...)
481 * @param cont_cls closure for cont
482 * @return number of bytes used (on the physical network, with overheads);
483 * -1 on hard errors (i.e. address invalid); 0 is a legal value
484 * and does NOT mean that the message was not transmitted (DV)
487 dv_plugin_send (void *cls,
488 struct Session *session,
489 const char *msgbuf, size_t msgbuf_size, unsigned int priority,
490 struct GNUNET_TIME_Relative timeout,
491 GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls)
493 struct PendingRequest *pr;
494 const struct GNUNET_MessageHeader *msg;
495 struct GNUNET_MessageHeader *box;
498 msg = (const struct GNUNET_MessageHeader *) msgbuf;
499 if (ntohs (msg->size) != msgbuf_size)
502 box = GNUNET_malloc (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
503 box->type = htons (GNUNET_MESSAGE_TYPE_DV_BOX);
504 box->size = htons (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
505 memcpy (&box[1], msgbuf, msgbuf_size);
508 pr = GNUNET_new (struct PendingRequest);
509 pr->transmit_cont = cont;
510 pr->transmit_cont_cls = cont_cls;
511 pr->session = session;
512 GNUNET_CONTAINER_DLL_insert_tail (session->pr_head,
515 pr->th = GNUNET_DV_send (session->plugin->dvh,
520 GNUNET_free_non_null (box);
526 * Function that can be used to force the plugin to disconnect
527 * from the given peer and cancel all previous transmissions
528 * (and their continuations).
531 * @param target peer from which to disconnect
534 dv_plugin_disconnect (void *cls, const struct GNUNET_PeerIdentity *target)
536 struct Plugin *plugin = cls;
537 struct Session *session;
538 struct PendingRequest *pr;
540 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
543 return; /* nothing to do */
544 while (NULL != (pr = session->pr_head))
546 GNUNET_CONTAINER_DLL_remove (session->pr_head,
549 GNUNET_DV_send_cancel (pr->th);
551 if (NULL != pr->transmit_cont)
552 pr->transmit_cont (pr->transmit_cont_cls,
554 GNUNET_SYSERR, 0, 0);
557 session->active = GNUNET_NO;
562 * Convert the transports address to a nice, human-readable
566 * @param type name of the transport that generated the address
567 * @param addr one of the addresses of the host, NULL for the last address
568 * the specific address format depends on the transport
569 * @param addrlen length of the address
570 * @param numeric should (IP) addresses be displayed in numeric form?
571 * @param timeout after how long should we give up?
572 * @param asc function to call on each string
573 * @param asc_cls closure for asc
576 dv_plugin_address_pretty_printer (void *cls, const char *type, const void *addr,
577 size_t addrlen, int numeric,
578 struct GNUNET_TIME_Relative timeout,
579 GNUNET_TRANSPORT_AddressStringCallback asc,
582 if ( (0 == addrlen) &&
583 (0 == strcmp (type, "dv")) )
590 * Convert the DV address to a pretty string.
593 * @param addr the (hopefully) DV address
594 * @param addrlen the length of the address
596 * @return string representing the DV address
599 dv_plugin_address_to_string (void *cls, const void *addr, size_t addrlen)
603 GNUNET_break (0); /* malformed */
611 * Another peer has suggested an address for this peer and transport
612 * plugin. Check that this could be a valid address. This function
613 * is not expected to 'validate' the address in the sense of trying to
614 * connect to it but simply to see if the binary format is technically
615 * legal for establishing a connection to this peer (and make sure that
616 * the address really corresponds to our network connection/settings
617 * and not some potential man-in-the-middle).
620 * @param addr pointer to the address
621 * @param addrlen length of addr
622 * @return GNUNET_OK if this is a plausible address for this peer
623 * and transport, GNUNET_SYSERR if not
627 dv_plugin_check_address (void *cls, const void *addr, size_t addrlen)
630 return GNUNET_SYSERR;
636 * Create a new session to transmit data to the target
637 * This session will used to send data to this peer and the plugin will
638 * notify us by calling the env->session_end function
640 * @param cls the plugin
641 * @param address the address
642 * @return the session if the address is valid, NULL otherwise
644 static struct Session *
645 dv_get_session (void *cls,
646 const struct GNUNET_HELLO_Address *address)
648 struct Plugin *plugin = cls;
649 struct Session *session;
651 if (0 != address->address_length)
653 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
656 return NULL; /* not valid right now */
657 session->active = GNUNET_YES;
663 * Function called to convert a string address to
666 * @param cls closure ('struct Plugin*')
667 * @param addr string address
668 * @param addrlen length of the address including \0 termination
669 * @param buf location to store the buffer
670 * If the function returns GNUNET_SYSERR, its contents are undefined.
671 * @param added length of created address
672 * @return GNUNET_OK on success, GNUNET_SYSERR on failure
675 dv_plugin_string_to_address (void *cls,
681 if ( (addrlen == 3) &&
682 (0 == strcmp ("dv", addr)) )
687 return GNUNET_SYSERR;
693 * Function to obtain the network type for a session
694 * FIXME: we should probably look at the network type
695 * used by the next hop here. Or find some other way
696 * to properly allow ATS-DV resource allocation.
698 * @param cls closure ('struct Plugin*')
699 * @param session the session
700 * @return the network type
702 static enum GNUNET_ATS_Network_Type
703 dv_get_network (void *cls,
704 struct Session *session)
706 GNUNET_assert (NULL != session);
707 return session->network;
712 * Entry point for the plugin.
714 * @param cls closure with the plugin environment
718 libgnunet_plugin_transport_dv_init (void *cls)
720 struct GNUNET_TRANSPORT_PluginEnvironment *env = cls;
721 struct GNUNET_TRANSPORT_PluginFunctions *api;
722 struct Plugin *plugin;
724 plugin = GNUNET_new (struct Plugin);
726 plugin->sessions = GNUNET_CONTAINER_multipeermap_create (1024 * 8, GNUNET_YES);
727 plugin->mst = GNUNET_SERVER_mst_create (&unbox_cb,
729 plugin->dvh = GNUNET_DV_service_connect (env->cfg,
732 &handle_dv_distance_changed,
733 &handle_dv_disconnect,
734 &handle_dv_message_received);
735 if (NULL == plugin->dvh)
737 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
738 GNUNET_SERVER_mst_destroy (plugin->mst);
739 GNUNET_free (plugin);
742 api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions);
744 api->send = &dv_plugin_send;
745 api->disconnect = &dv_plugin_disconnect;
746 api->address_pretty_printer = &dv_plugin_address_pretty_printer;
747 api->check_address = &dv_plugin_check_address;
748 api->address_to_string = &dv_plugin_address_to_string;
749 api->string_to_address = &dv_plugin_string_to_address;
750 api->get_session = &dv_get_session;
751 api->get_network = &dv_get_network;
757 * Function called to free a session.
761 * @param value session to free
762 * @return GNUNET_OK (continue to iterate)
765 free_session_iterator (void *cls,
766 const struct GNUNET_PeerIdentity *key,
769 struct Session *session = value;
771 free_session (session);
777 * Exit point from the plugin.
779 * @param cls plugin API
783 libgnunet_plugin_transport_dv_done (void *cls)
785 struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
786 struct Plugin *plugin = api->cls;
788 GNUNET_DV_service_disconnect (plugin->dvh);
789 GNUNET_CONTAINER_multipeermap_iterate (plugin->sessions,
790 &free_session_iterator,
792 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
793 GNUNET_SERVER_mst_destroy (plugin->mst);
794 GNUNET_free (plugin);
799 /* end of plugin_transport_dv.c */