2 This file is part of GNUnet
3 (C) 2002--2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
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->plugin = plugin;
318 session->distance = distance;
319 session->network = network;
321 GNUNET_YES == GNUNET_CONTAINER_multipeermap_put (plugin->sessions,
322 &session->sender, session,
323 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
325 LOG (GNUNET_ERROR_TYPE_DEBUG,
326 "Creating new session %p for peer `%s'\n",
330 /* Notify transport and ats about new connection */
331 ats[0].type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
332 ats[0].value = htonl (distance);
333 ats[1].type = htonl (GNUNET_ATS_NETWORK_TYPE);
334 ats[1].value = htonl (network);
335 plugin->env->session_start (plugin->env->cls, peer, PLUGIN_NAME, NULL, 0,
341 * Function called if DV distance to a peer is changed.
343 * @param cls closure with 'struct Plugin'
344 * @param peer connected peer
345 * @param distance new distance to the peer
348 handle_dv_distance_changed (void *cls,
349 const struct GNUNET_PeerIdentity *peer,
352 struct Plugin *plugin = cls;
353 struct Session *session;
355 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received `%s' message for peer `%s': new distance %u\n",
356 "DV_DISTANCE_CHANGED",
357 GNUNET_i2s (peer), distance);
359 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
365 handle_dv_connect (plugin, peer, distance, 0);
368 session->distance = distance;
369 if (GNUNET_YES == session->active)
370 notify_distance_change (session);
375 * Release session object and clean up associated resources.
377 * @param session session to clean up
380 free_session (struct Session *session)
382 struct Plugin *plugin = session->plugin;
383 struct PendingRequest *pr;
385 GNUNET_assert (GNUNET_YES ==
386 GNUNET_CONTAINER_multipeermap_remove (plugin->sessions,
390 LOG (GNUNET_ERROR_TYPE_DEBUG,
391 "Freeing session %p for peer `%s'\n",
393 GNUNET_i2s (&session->sender));
395 if (GNUNET_YES == session->active)
396 plugin->env->session_end (plugin->env->cls,
399 while (NULL != (pr = session->pr_head))
401 GNUNET_CONTAINER_DLL_remove (session->pr_head,
404 GNUNET_DV_send_cancel (pr->th);
406 if (NULL != pr->transmit_cont)
407 pr->transmit_cont (pr->transmit_cont_cls,
409 GNUNET_SYSERR, 0, 0);
412 GNUNET_free (session);
417 * Function called if DV is no longer able to talk to a peer.
419 * @param cls closure with 'struct Plugin'
420 * @param peer peer that disconnected
423 handle_dv_disconnect (void *cls,
424 const struct GNUNET_PeerIdentity *peer)
426 struct Plugin *plugin = cls;
427 struct Session *session;
429 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received `%s' message for peer `%s'\n",
433 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
436 return; /* nothing to do */
438 free_session (session);
443 * Function called once the delivery of a message has been successful.
444 * Clean up the pending request, and call continuations.
447 * @param ok GNUNET_OK on success, GNUNET_SYSERR on error
450 send_finished (void *cls,
453 struct PendingRequest *pr = cls;
454 struct Session *session = pr->session;
457 GNUNET_CONTAINER_DLL_remove (session->pr_head,
460 if (NULL != pr->transmit_cont)
461 pr->transmit_cont (pr->transmit_cont_cls,
469 * Function that can be used by the transport service to transmit
470 * a message using the plugin.
473 * @param session the session used
474 * @param priority how important is the message
475 * @param msgbuf the message to transmit
476 * @param msgbuf_size number of bytes in 'msgbuf'
477 * @param timeout when should we time out
478 * @param cont continuation to call once the message has
479 * been transmitted (or if the transport is ready
480 * for the next transmission call; or if the
481 * peer disconnected...)
482 * @param cont_cls closure for cont
483 * @return number of bytes used (on the physical network, with overheads);
484 * -1 on hard errors (i.e. address invalid); 0 is a legal value
485 * and does NOT mean that the message was not transmitted (DV)
488 dv_plugin_send (void *cls,
489 struct Session *session,
490 const char *msgbuf, size_t msgbuf_size, unsigned int priority,
491 struct GNUNET_TIME_Relative timeout,
492 GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls)
494 struct Plugin *plugin = cls;
495 struct PendingRequest *pr;
496 const struct GNUNET_MessageHeader *msg;
497 struct GNUNET_MessageHeader *box;
500 msg = (const struct GNUNET_MessageHeader *) msgbuf;
501 if (ntohs (msg->size) != msgbuf_size)
504 box = GNUNET_malloc (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
505 box->type = htons (GNUNET_MESSAGE_TYPE_DV_BOX);
506 box->size = htons (sizeof (struct GNUNET_MessageHeader) + msgbuf_size);
507 memcpy (&box[1], msgbuf, msgbuf_size);
510 pr = GNUNET_new (struct PendingRequest);
511 pr->transmit_cont = cont;
512 pr->transmit_cont_cls = cont_cls;
513 pr->session = session;
514 GNUNET_CONTAINER_DLL_insert_tail (session->pr_head,
518 pr->th = GNUNET_DV_send (plugin->dvh,
523 GNUNET_free_non_null (box);
529 * Function that can be used to force the plugin to disconnect
530 * from the given peer and cancel all previous transmissions
531 * (and their continuations).
534 * @param target peer from which to disconnect
537 dv_plugin_disconnect (void *cls, const struct GNUNET_PeerIdentity *target)
539 struct Plugin *plugin = cls;
540 struct Session *session;
541 struct PendingRequest *pr;
543 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
546 return; /* nothing to do */
547 while (NULL != (pr = session->pr_head))
549 GNUNET_CONTAINER_DLL_remove (session->pr_head,
552 GNUNET_DV_send_cancel (pr->th);
554 if (NULL != pr->transmit_cont)
555 pr->transmit_cont (pr->transmit_cont_cls,
557 GNUNET_SYSERR, 0, 0);
560 session->active = GNUNET_NO;
565 * Convert the transports address to a nice, human-readable
569 * @param type name of the transport that generated the address
570 * @param addr one of the addresses of the host, NULL for the last address
571 * the specific address format depends on the transport
572 * @param addrlen length of the address
573 * @param numeric should (IP) addresses be displayed in numeric form?
574 * @param timeout after how long should we give up?
575 * @param asc function to call on each string
576 * @param asc_cls closure for asc
579 dv_plugin_address_pretty_printer (void *cls, const char *type, const void *addr,
580 size_t addrlen, int numeric,
581 struct GNUNET_TIME_Relative timeout,
582 GNUNET_TRANSPORT_AddressStringCallback asc,
585 if ( (0 == addrlen) &&
586 (0 == strcmp (type, "dv")) )
593 * Convert the DV address to a pretty string.
596 * @param addr the (hopefully) DV address
597 * @param addrlen the length of the address
599 * @return string representing the DV address
602 dv_plugin_address_to_string (void *cls, const void *addr, size_t addrlen)
606 GNUNET_break (0); /* malformed */
614 * Another peer has suggested an address for this peer and transport
615 * plugin. Check that this could be a valid address. This function
616 * is not expected to 'validate' the address in the sense of trying to
617 * connect to it but simply to see if the binary format is technically
618 * legal for establishing a connection to this peer (and make sure that
619 * the address really corresponds to our network connection/settings
620 * and not some potential man-in-the-middle).
623 * @param addr pointer to the address
624 * @param addrlen length of addr
625 * @return GNUNET_OK if this is a plausible address for this peer
626 * and transport, GNUNET_SYSERR if not
630 dv_plugin_check_address (void *cls, const void *addr, size_t addrlen)
633 return GNUNET_SYSERR;
639 * Create a new session to transmit data to the target
640 * This session will used to send data to this peer and the plugin will
641 * notify us by calling the env->session_end function
643 * @param cls the plugin
644 * @param address the address
645 * @return the session if the address is valid, NULL otherwise
647 static struct Session *
648 dv_get_session (void *cls,
649 const struct GNUNET_HELLO_Address *address)
651 struct Plugin *plugin = cls;
652 struct Session *session;
654 if (0 != address->address_length)
656 session = GNUNET_CONTAINER_multipeermap_get (plugin->sessions,
659 return NULL; /* not valid right now */
660 session->active = GNUNET_YES;
666 * Function called to convert a string address to
669 * @param cls closure ('struct Plugin*')
670 * @param addr string address
671 * @param addrlen length of the address including \0 termination
672 * @param buf location to store the buffer
673 * If the function returns GNUNET_SYSERR, its contents are undefined.
674 * @param added length of created address
675 * @return GNUNET_OK on success, GNUNET_SYSERR on failure
678 dv_plugin_string_to_address (void *cls,
684 if ( (addrlen == 3) &&
685 (0 == strcmp ("dv", addr)) )
690 return GNUNET_SYSERR;
696 * Function to obtain the network type for a session
697 * FIXME: we should probably look at the network type
698 * used by the next hop here. Or find some other way
699 * to properly allow ATS-DV resource allocation.
701 * @param cls closure ('struct Plugin*')
702 * @param session the session
703 * @return the network type
705 static enum GNUNET_ATS_Network_Type
706 dv_get_network (void *cls,
707 struct Session *session)
709 GNUNET_assert (NULL != session);
710 return session->network;
715 * Entry point for the plugin.
717 * @param cls closure with the plugin environment
721 libgnunet_plugin_transport_dv_init (void *cls)
723 struct GNUNET_TRANSPORT_PluginEnvironment *env = cls;
724 struct GNUNET_TRANSPORT_PluginFunctions *api;
725 struct Plugin *plugin;
727 plugin = GNUNET_new (struct Plugin);
729 plugin->sessions = GNUNET_CONTAINER_multipeermap_create (1024 * 8, GNUNET_YES);
730 plugin->mst = GNUNET_SERVER_mst_create (&unbox_cb,
732 plugin->dvh = GNUNET_DV_service_connect (env->cfg,
735 &handle_dv_distance_changed,
736 &handle_dv_disconnect,
737 &handle_dv_message_received);
738 if (NULL == plugin->dvh)
740 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
741 GNUNET_SERVER_mst_destroy (plugin->mst);
742 GNUNET_free (plugin);
745 api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions);
747 api->send = &dv_plugin_send;
748 api->disconnect = &dv_plugin_disconnect;
749 api->address_pretty_printer = &dv_plugin_address_pretty_printer;
750 api->check_address = &dv_plugin_check_address;
751 api->address_to_string = &dv_plugin_address_to_string;
752 api->string_to_address = &dv_plugin_string_to_address;
753 api->get_session = &dv_get_session;
754 api->get_network = &dv_get_network;
760 * Function called to free a session.
764 * @param value session to free
765 * @return GNUNET_OK (continue to iterate)
768 free_session_iterator (void *cls,
769 const struct GNUNET_PeerIdentity *key,
772 struct Session *session = value;
774 free_session (session);
780 * Exit point from the plugin.
782 * @param cls plugin API
786 libgnunet_plugin_transport_dv_done (void *cls)
788 struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
789 struct Plugin *plugin = api->cls;
791 GNUNET_DV_service_disconnect (plugin->dvh);
792 GNUNET_CONTAINER_multipeermap_iterate (plugin->sessions,
793 &free_session_iterator,
795 GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions);
796 GNUNET_SERVER_mst_destroy (plugin->mst);
797 GNUNET_free (plugin);
802 /* end of plugin_transport_dv.c */