2 This file is part of GNUnet.
3 (C) 2009, 2010, 2011 Christian Grothoff (and other contributing authors)
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13 General Public License for more details.
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22 * @file core/gnunet-service-core_neighbours.c
23 * @brief code for managing low-level 'plaintext' connections with transport (key exchange may or may not be done yet)
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
28 #include "gnunet_statistics_service.h"
29 #include "gnunet_transport_service.h"
30 #include "gnunet-service-core.h"
31 #include "gnunet-service-core_neighbours.h"
32 #include "gnunet-service-core_kx.h"
33 #include "gnunet-service-core_sessions.h"
34 #include "gnunet_constants.h"
38 * Message ready for transmission via transport service. This struct
39 * is followed by the actual content of the message.
41 struct NeighbourMessageEntry
45 * We keep messages in a doubly linked list.
47 struct NeighbourMessageEntry *next;
50 * We keep messages in a doubly linked list.
52 struct NeighbourMessageEntry *prev;
55 * By when are we supposed to transmit this message?
57 struct GNUNET_TIME_Absolute deadline;
60 * How long is the message? (number of bytes following the "struct
61 * MessageEntry", but not including the size of "struct
62 * MessageEntry" itself!)
70 * Data kept per transport-connected peer.
76 * Head of the batched message queue (already ordered, transmit
77 * starting with the head).
79 struct NeighbourMessageEntry *message_head;
82 * Tail of the batched message queue (already ordered, append new
85 struct NeighbourMessageEntry *message_tail;
88 * Handle for pending requests for transmission to this peer
89 * with the transport service. NULL if no request is pending.
91 struct GNUNET_TRANSPORT_TransmitHandle *th;
94 * Information about the key exchange with the other peer.
96 struct GSC_KeyExchangeInfo *kxinfo;
99 * Identity of the other peer.
101 struct GNUNET_PeerIdentity peer;
104 * ID of task used for re-trying plaintext scheduling.
106 GNUNET_SCHEDULER_TaskIdentifier retry_plaintext_task;
112 * Map of peer identities to 'struct Neighbour'.
114 static struct GNUNET_CONTAINER_MultiPeerMap *neighbours;
119 static struct GNUNET_TRANSPORT_Handle *transport;
123 * Find the entry for the given neighbour.
125 * @param peer identity of the neighbour
126 * @return NULL if we are not connected, otherwise the
129 static struct Neighbour *
130 find_neighbour (const struct GNUNET_PeerIdentity *peer)
132 if (NULL == neighbours)
134 return GNUNET_CONTAINER_multipeermap_get (neighbours, peer);
139 * Free the given entry for the neighbour.
141 * @param n neighbour to free
144 free_neighbour (struct Neighbour *n)
146 struct NeighbourMessageEntry *m;
148 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
149 "Destroying neighbour entry for peer `%4s'\n",
150 GNUNET_i2s (&n->peer));
151 while (NULL != (m = n->message_head))
153 GNUNET_CONTAINER_DLL_remove (n->message_head, n->message_tail, m);
158 GNUNET_TRANSPORT_notify_transmit_ready_cancel (n->th);
161 GNUNET_STATISTICS_update (GSC_stats,
163 ("# sessions terminated by transport disconnect"),
165 if (NULL != n->kxinfo)
167 GSC_KX_stop (n->kxinfo);
170 if (n->retry_plaintext_task != GNUNET_SCHEDULER_NO_TASK)
172 GNUNET_SCHEDULER_cancel (n->retry_plaintext_task);
173 n->retry_plaintext_task = GNUNET_SCHEDULER_NO_TASK;
175 GNUNET_assert (GNUNET_OK ==
176 GNUNET_CONTAINER_multipeermap_remove (neighbours,
178 GNUNET_STATISTICS_set (GSC_stats,
179 gettext_noop ("# neighbour entries allocated"),
180 GNUNET_CONTAINER_multipeermap_size (neighbours),
187 * Check if we have encrypted messages for the specified neighbour
188 * pending, and if so, check with the transport about sending them
191 * @param n neighbour to check.
194 process_queue (struct Neighbour *n);
198 * Function called when the transport service is ready to receive a
199 * message for the respective peer
201 * @param cls neighbour to use message from
202 * @param size number of bytes we can transmit
203 * @param buf where to copy the message
204 * @return number of bytes transmitted
207 transmit_ready (void *cls, size_t size, void *buf)
209 struct Neighbour *n = cls;
210 struct NeighbourMessageEntry *m;
221 GNUNET_CONTAINER_DLL_remove (n->message_head, n->message_tail, m);
224 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
225 "Transmission of message of type %u and size %u failed\n",
227 ntohs (((struct GNUNET_MessageHeader *) &m[1])->type),
228 (unsigned int) m->size);
234 GNUNET_assert (size >= m->size);
235 memcpy (cbuf, &m[1], m->size);
237 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
238 "Copied message of type %u and size %u into transport buffer for `%4s'\n",
240 ntohs (((struct GNUNET_MessageHeader *) &m[1])->type),
241 (unsigned int) ret, GNUNET_i2s (&n->peer));
244 GNUNET_STATISTICS_update (GSC_stats,
246 ("# encrypted bytes given to transport"), ret,
253 * Check if we have messages for the specified neighbour pending, and
254 * if so, check with the transport about sending them out.
256 * @param n neighbour to check.
259 process_queue (struct Neighbour *n)
261 struct NeighbourMessageEntry *m;
264 return; /* request already pending */
268 /* notify sessions that the queue is empty and more messages
269 * could thus be queued now */
270 GSC_SESSIONS_solicit (&n->peer);
273 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
274 "Asking transport for transmission of %u bytes to `%4s' in next %s\n",
275 (unsigned int) m->size, GNUNET_i2s (&n->peer),
276 GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_remaining (m->deadline), GNUNET_NO));
278 GNUNET_TRANSPORT_notify_transmit_ready (transport, &n->peer, m->size,
279 GNUNET_TIME_absolute_get_remaining
280 (m->deadline), &transmit_ready,
284 /* message request too large or duplicate request */
286 /* discard encrypted message */
287 GNUNET_CONTAINER_DLL_remove (n->message_head, n->message_tail, m);
295 * Function called by transport to notify us that
296 * a peer connected to us (on the network level).
299 * @param peer the peer that connected
302 handle_transport_notify_connect (void *cls,
303 const struct GNUNET_PeerIdentity *peer)
307 if (0 == memcmp (peer, &GSC_my_identity, sizeof (struct GNUNET_PeerIdentity)))
312 n = find_neighbour (peer);
315 /* duplicate connect notification!? */
319 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
320 "Received connection from `%4s'.\n",
322 n = GNUNET_new (struct Neighbour);
324 GNUNET_assert (GNUNET_OK ==
325 GNUNET_CONTAINER_multipeermap_put (neighbours,
327 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
328 GNUNET_STATISTICS_set (GSC_stats,
329 gettext_noop ("# neighbour entries allocated"),
330 GNUNET_CONTAINER_multipeermap_size (neighbours),
332 n->kxinfo = GSC_KX_start (peer);
337 * Function called by transport telling us that a peer
341 * @param peer the peer that disconnected
344 handle_transport_notify_disconnect (void *cls,
345 const struct GNUNET_PeerIdentity *peer)
349 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
350 "Peer `%4s' disconnected from us; received notification from transport.\n",
352 n = find_neighbour (peer);
363 * Function called by the transport for each received message.
366 * @param peer (claimed) identity of the other peer
367 * @param message the message
370 handle_transport_receive (void *cls, const struct GNUNET_PeerIdentity *peer,
371 const struct GNUNET_MessageHeader *message)
376 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
377 "Received message of type %u from `%4s', demultiplexing.\n",
378 (unsigned int) ntohs (message->type), GNUNET_i2s (peer));
379 if (0 == memcmp (peer, &GSC_my_identity, sizeof (struct GNUNET_PeerIdentity)))
384 n = find_neighbour (peer);
387 /* received message from peer that is not connected!? */
391 type = ntohs (message->type);
394 case GNUNET_MESSAGE_TYPE_CORE_EPHEMERAL_KEY:
395 GSC_KX_handle_ephemeral_key (n->kxinfo, message);
397 case GNUNET_MESSAGE_TYPE_CORE_PING:
398 GSC_KX_handle_ping (n->kxinfo, message);
400 case GNUNET_MESSAGE_TYPE_CORE_PONG:
401 GSC_KX_handle_pong (n->kxinfo, message);
403 case GNUNET_MESSAGE_TYPE_CORE_ENCRYPTED_MESSAGE:
404 GSC_KX_handle_encrypted_message (n->kxinfo, message);
406 case GNUNET_MESSAGE_TYPE_DUMMY:
407 /* Dummy messages for testing / benchmarking, just discard */
410 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
412 ("Unsupported message of type %u (%u bytes) received from peer `%s'\n"),
413 (unsigned int) type, (unsigned int) ntohs (message->size),
421 * Transmit the given message to the given target.
423 * @param target peer that should receive the message (must be connected)
424 * @param msg message to transmit
425 * @param timeout by when should the transmission be done?
428 GSC_NEIGHBOURS_transmit (const struct GNUNET_PeerIdentity *target,
429 const struct GNUNET_MessageHeader *msg,
430 struct GNUNET_TIME_Relative timeout)
432 struct NeighbourMessageEntry *me;
436 n = find_neighbour (target);
442 msize = ntohs (msg->size);
443 me = GNUNET_malloc (sizeof (struct NeighbourMessageEntry) + msize);
444 me->deadline = GNUNET_TIME_relative_to_absolute (timeout);
446 memcpy (&me[1], msg, msize);
447 GNUNET_CONTAINER_DLL_insert_tail (n->message_head, n->message_tail, me);
453 * Initialize neighbours subsystem.
456 GSC_NEIGHBOURS_init ()
458 neighbours = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_NO);
460 GNUNET_TRANSPORT_connect (GSC_cfg, &GSC_my_identity, NULL,
461 &handle_transport_receive,
462 &handle_transport_notify_connect,
463 &handle_transport_notify_disconnect);
464 if (NULL == transport)
466 GNUNET_CONTAINER_multipeermap_destroy (neighbours);
468 return GNUNET_SYSERR;
475 * Wrapper around 'free_neighbour'.
478 * @param key peer identity
479 * @param value the 'struct Neighbour' to free
480 * @return GNUNET_OK (continue to iterate)
483 free_neighbour_helper (void *cls,
484 const struct GNUNET_PeerIdentity * key,
487 struct Neighbour *n = value;
489 /* transport should have 'disconnected' all neighbours... */
497 * Shutdown neighbours subsystem.
500 GSC_NEIGHBOURS_done ()
502 if (NULL != transport)
504 GNUNET_TRANSPORT_disconnect (transport);
507 if (NULL != neighbours)
509 GNUNET_CONTAINER_multipeermap_iterate (neighbours, &free_neighbour_helper,
511 GNUNET_CONTAINER_multipeermap_destroy (neighbours);
516 /* end of gnunet-service-core_neighbours.c */