2 This file is part of GNUnet.
3 (C) 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 #include "gnunet_util_lib.h"
24 #include "gnunet_signatures.h"
25 #include "gnunet_statistics_service.h"
27 #include "mesh_protocol.h"
28 #include "mesh_path.h"
30 #include "gnunet-service-mesh_tunnel.h"
31 #include "gnunet-service-mesh_connection.h"
32 #include "gnunet-service-mesh_channel.h"
33 #include "gnunet-service-mesh_peer.h"
35 #define LOG(level, ...) GNUNET_log_from(level,"mesh-tun",__VA_ARGS__)
37 #define REKEY_WAIT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5)
39 /******************************************************************************/
40 /******************************** STRUCTS **********************************/
41 /******************************************************************************/
45 struct MeshTChannel *next;
46 struct MeshTChannel *prev;
47 struct MeshChannel *ch;
50 struct MeshTConnection
52 struct MeshTConnection *next;
53 struct MeshTConnection *prev;
54 struct MeshConnection *c;
58 * Structure used during a Key eXchange.
60 struct MeshTunnelKXCtx
63 * Decryption ("their") old key, for decrypting traffic sent by the
64 * other end before the key exchange started.
66 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
69 * Challenge to send in a ping and expect in the pong.
75 * Struct containing all information regarding a tunnel to a peer.
80 * Endpoint of the tunnel.
82 struct MeshPeer *peer;
85 * State of the tunnel.
87 enum MeshTunnel3State state;
90 * Key eXchange context.
92 struct MeshTunnelKXCtx *kx_ctx;
95 * Encryption ("our") key.
97 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
100 * Decryption ("their") key.
102 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
105 * Task to start the rekey process.
107 GNUNET_SCHEDULER_TaskIdentifier rekey_task;
110 * Paths that are actively used to reach the destination peer.
112 struct MeshTConnection *connection_head;
113 struct MeshTConnection *connection_tail;
116 * Next connection number.
121 * Channels inside this tunnel.
123 struct MeshTChannel *channel_head;
124 struct MeshTChannel *channel_tail;
127 * Channel ID for the next created channel.
129 MESH_ChannelNumber next_chid;
132 * Destroy flag: if true, destroy on last message.
137 * Queued messages, to transmit once tunnel gets connected.
139 struct MeshTunnelDelayed *tq_head;
140 struct MeshTunnelDelayed *tq_tail;
145 * Struct used to save messages in a non-ready tunnel to send once connected.
147 struct MeshTunnelDelayed
152 struct MeshTunnelDelayed *next;
153 struct MeshTunnelDelayed *prev;
158 struct MeshChannel *ch;
163 /* struct GNUNET_MessageHeader *msg; */
168 * Handle for messages queued but not yet sent.
170 struct MeshTunnel3Queue
173 * Connection queue handle, to cancel if necessary.
175 struct MeshConnectionQueue *q;
178 * Continuation to call once sent.
183 * Closure for @c cont.
189 /******************************************************************************/
190 /******************************* GLOBALS ***********************************/
191 /******************************************************************************/
194 * Global handle to the statistics service.
196 extern struct GNUNET_STATISTICS_Handle *stats;
199 * Local peer own ID (memory efficient handle).
201 extern GNUNET_PEER_Id myid;
204 * Local peer own ID (full value).
206 extern struct GNUNET_PeerIdentity my_full_id;
210 * Set of all tunnels, in order to trigger a new exchange on rekey.
211 * Indexed by peer's ID.
213 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
216 * Default TTL for payload packets.
218 static unsigned long long default_ttl;
223 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
226 * Own ephemeral private key.
228 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
231 * Cached message used to perform a key exchange.
233 static struct GNUNET_MESH_KX_Ephemeral kx_msg;
236 * Task to generate a new ephemeral key.
238 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
243 static struct GNUNET_TIME_Relative rekey_period;
245 /******************************************************************************/
246 /******************************** STATIC ***********************************/
247 /******************************************************************************/
250 * Get string description for tunnel state.
252 * @param s Tunnel state.
254 * @return String representation.
257 GMT_state2s (enum MeshTunnel3State s)
259 static char buf[128];
263 case MESH_TUNNEL3_NEW:
264 return "MESH_TUNNEL3_NEW";
265 case MESH_TUNNEL3_SEARCHING:
266 return "MESH_TUNNEL3_SEARCHING";
267 case MESH_TUNNEL3_WAITING:
268 return "MESH_TUNNEL3_WAITING";
269 case MESH_TUNNEL3_KEY_SENT:
270 return "MESH_TUNNEL3_KEY_SENT";
271 case MESH_TUNNEL3_READY:
272 return "MESH_TUNNEL3_READY";
273 case MESH_TUNNEL3_RECONNECTING:
274 return "MESH_TUNNEL3_RECONNECTING";
275 case MESH_TUNNEL3_REKEY:
276 return "MESH_TUNNEL3_REKEY";
279 sprintf (buf, "%u (UNKNOWN STATE)", s);
286 * Ephemeral key message purpose size.
288 * @return Size of the part of the ephemeral key message that must be signed.
291 ephemeral_purpose_size (void)
293 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
294 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
295 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
296 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
297 sizeof (struct GNUNET_PeerIdentity);
302 * Size of the encrypted part of a ping message.
304 * @return Size of the encrypted part of a ping message.
307 ping_encryption_size (void)
309 return sizeof (struct GNUNET_PeerIdentity) + sizeof (uint32_t);
314 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
316 * @param tch Tunnel's channel handle.
318 * @return Amount of messages the channel can still buffer towards the client.
321 get_channel_buffer (const struct MeshTChannel *tch)
325 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
326 fwd = GMCH_is_origin (tch->ch, GNUNET_YES);
328 return GMCH_get_buffer (tch->ch, fwd);
333 * Get the channel's allowance status.
335 * @param tch Tunnel's channel handle.
337 * @return #GNUNET_YES if we allowed the client to send data to us.
340 get_channel_allowed (const struct MeshTChannel *tch)
344 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
345 fwd = GMCH_is_origin (tch->ch, GNUNET_YES);
347 return GMCH_get_allowed (tch->ch, fwd);
352 * Get the connection's buffer.
354 * @param tc Tunnel's connection handle.
356 * @return Amount of messages the connection can still buffer.
359 get_connection_buffer (const struct MeshTConnection *tc)
363 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
364 fwd = GMC_is_origin (tc->c, GNUNET_YES);
366 return GMC_get_buffer (tc->c, fwd);
371 * Get the connection's allowance.
373 * @param tc Tunnel's connection handle.
375 * @return Amount of messages we have allowed the next peer to send us.
378 get_connection_allowed (const struct MeshTConnection *tc)
382 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
383 fwd = GMC_is_origin (tc->c, GNUNET_YES);
385 return GMC_get_allowed (tc->c, fwd);
390 * Check that a ephemeral key message s well formed and correctly signed.
392 * @param t Tunnel on which the message came.
393 * @param msg The ephemeral key message.
395 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
398 check_ephemeral (struct MeshTunnel3 *t,
399 const struct GNUNET_MESH_KX_Ephemeral *msg)
401 /* Check message size */
402 if (ntohs (msg->header.size) != sizeof (struct GNUNET_MESH_KX_Ephemeral))
403 return GNUNET_SYSERR;
405 /* Check signature size */
406 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
407 return GNUNET_SYSERR;
410 if (0 != memcmp (&msg->origin_identity,
411 GMP_get_id (t->peer),
412 sizeof (struct GNUNET_PeerIdentity)))
413 return GNUNET_SYSERR;
415 /* Check signature */
417 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_MESH_KX,
420 &msg->origin_identity.public_key))
421 return GNUNET_SYSERR;
428 * Encrypt data with the tunnel key.
430 * @param t Tunnel whose key to use.
431 * @param dst Destination for the encrypted data.
432 * @param src Source of the plaintext. Can overlap with @c dst.
433 * @param size Size of the plaintext.
434 * @param iv Initialization Vector to use.
437 t_encrypt (struct MeshTunnel3 *t,
438 void *dst, const void *src,
439 size_t size, uint32_t iv)
441 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
443 GNUNET_CRYPTO_symmetric_derive_iv (&siv, &t->e_key, &iv, sizeof (uint32_t), NULL);
444 return GNUNET_CRYPTO_symmetric_encrypt (src, size, &t->e_key, &siv, dst);
449 * Decrypt data with the tunnel key.
451 * @param t Tunnel whose key to use.
452 * @param dst Destination for the plaintext.
453 * @param src Source of the encrypted data. Can overlap with @c dst.
454 * @param size Size of the encrypted data.
455 * @param iv Initialization Vector to use.
458 t_decrypt (struct MeshTunnel3 *t,
459 void *dst, const void *src,
460 size_t size, uint32_t iv)
462 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
464 GNUNET_CRYPTO_symmetric_derive_iv (&siv, &t->d_key, &iv, sizeof (uint32_t), NULL);
465 return GNUNET_CRYPTO_symmetric_decrypt (src, size, &t->d_key, &siv, dst);
470 * Create key material by doing ECDH on the local and remote ephemeral keys.
472 * @param key_material Where to store the key material.
473 * @param ephemeral_key Peer's public ephemeral key.
476 derive_key_material (struct GNUNET_HashCode *key_material,
477 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
480 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
489 * Create a symmetic key from the identities of both ends and the key material
492 * @param key Destination for the generated key.
493 * @param sender ID of the peer that will encrypt with @c key.
494 * @param receiver ID of the peer that will decrypt with @c key.
495 * @param key_material Hash created with ECDH with the ephemeral keys.
498 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
499 const struct GNUNET_PeerIdentity *sender,
500 const struct GNUNET_PeerIdentity *receiver,
501 const struct GNUNET_HashCode *key_material)
503 const char salt[] = "MESH kx salt";
505 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
507 key_material, sizeof (struct GNUNET_HashCode),
508 sender, sizeof (struct GNUNET_PeerIdentity),
509 receiver, sizeof (struct GNUNET_PeerIdentity),
514 * Pick a connection on which send the next data message.
516 * @param t Tunnel on which to send the message.
518 * @return The connection on which to send the next message.
520 static struct MeshConnection *
521 tunnel_get_connection (struct MeshTunnel3 *t)
523 struct MeshTConnection *iter;
524 struct MeshConnection *best;
526 unsigned int lowest_q;
528 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GMP_2s (t->peer));
531 for (iter = t->connection_head; NULL != iter; iter = iter->next)
533 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
534 GNUNET_h2s (GMC_get_id (iter->c)), GMC_get_state (iter->c));
535 if (MESH_CONNECTION_READY == GMC_get_state (iter->c))
537 qn = GMC_get_qn (iter->c, GMC_is_origin (iter->c, GNUNET_YES));
538 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
551 * Send all cached messages that we can, tunnel is online.
553 * @param t Tunnel that holds the messages. Cannot be loopback.
556 send_queued_data (struct MeshTunnel3 *t)
558 struct MeshTunnelDelayed *tq;
559 struct MeshTunnelDelayed *next;
562 LOG (GNUNET_ERROR_TYPE_DEBUG,
563 "GMT_send_queued_data on tunnel %s\n",
566 if (GMT_is_loopback (t))
572 room = GMT_get_connections_buffer (t);
573 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
574 for (tq = t->tq_head; NULL != tq && room > 0; tq = next)
576 LOG (GNUNET_ERROR_TYPE_DEBUG, " data on channel %s\n", GMCH_2s (tq->ch));
579 GNUNET_CONTAINER_DLL_remove (t->tq_head, t->tq_tail, tq);
580 GMCH_send_prebuilt_message ((struct GNUNET_MessageHeader *) &tq[1],
581 tq->ch, GMCH_is_origin (tq->ch, GNUNET_YES),
586 LOG (GNUNET_ERROR_TYPE_DEBUG,
587 "GMT_send_queued_data end\n",
595 * Cache a message to be sent once tunnel is online.
597 * @param t Tunnel to hold the message.
598 * @param ch Channel the message is about.
599 * @param msg Message itself (copy will be made).
602 queue_data (struct MeshTunnel3 *t,
603 struct MeshChannel *ch,
604 const struct GNUNET_MessageHeader *msg)
606 struct MeshTunnelDelayed *tq;
607 uint16_t size = ntohs (msg->size);
609 if (MESH_TUNNEL3_READY == t->state)
615 tq = GNUNET_malloc (sizeof (struct MeshTunnelDelayed) + size);
618 memcpy (&tq[1], msg, size);
619 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tq);
625 * Sends key exchange message on a tunnel, choosing the best connection.
626 * Should not be called on loopback tunnels.
628 * @param t Tunnel on which this message is transmitted.
629 * @param message Message to send. Function modifies it.
632 send_kx (struct MeshTunnel3 *t,
633 const struct GNUNET_MessageHeader *message)
635 struct MeshConnection *c;
636 struct GNUNET_MESH_KX *msg;
637 size_t size = ntohs (message->size);
638 char cbuf[sizeof (struct GNUNET_MESH_KX) + size];
642 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GMT_2s (t));
644 /* Avoid loopback. */
645 if (GMT_is_loopback (t))
647 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
652 /* Must have a connection. */
653 if (NULL == t->connection_head)
659 msg = (struct GNUNET_MESH_KX *) cbuf;
660 msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX);
661 msg->header.size = htons (sizeof (struct GNUNET_MESH_KX) + size);
662 c = tunnel_get_connection (t);
665 GNUNET_break (GNUNET_YES == t->destroy);
668 type = ntohs (message->type);
671 case GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL:
672 case GNUNET_MESSAGE_TYPE_MESH_KX_PING:
673 case GNUNET_MESSAGE_TYPE_MESH_KX_PONG:
674 msg->reserved = htonl (0);
675 memcpy (&msg[1], message, size);
678 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
679 GNUNET_MESH_DEBUG_M2S (type));
683 fwd = GMC_is_origin (t->connection_head->c, GNUNET_YES);
684 /* TODO save handle and cancel in case of a unneeded retransmission */
685 GMC_send_prebuilt_message (&msg->header, c, fwd, NULL, NULL);
690 * Send the ephemeral key on a tunnel.
692 * @param t Tunnel on which to send the key.
695 send_ephemeral (struct MeshTunnel3 *t)
697 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s()\n", __FUNCTION__);
699 kx_msg.sender_status = htonl (t->state);
700 send_kx (t, &kx_msg.header);
704 * Send a ping message on a tunnel.
706 * @param t Tunnel on which to send the ping.
709 send_ping (struct MeshTunnel3 *t)
711 struct GNUNET_MESH_KX_Ping msg;
713 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s()\n", __FUNCTION__);
714 msg.header.size = htons (sizeof (msg));
715 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_PING);
716 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
717 msg.target = *GMP_get_id (t->peer);
718 msg.nonce = t->kx_ctx->challenge;
720 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
721 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&msg.target));
722 t_encrypt (t, &msg.target, &msg.target, ping_encryption_size(), msg.iv);
723 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
724 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg.target));
726 send_kx (t, &msg.header);
731 * Send a pong message on a tunnel.
733 * @param t Tunnel on which to send the pong.
734 * @param challenge Value sent in the ping that we have to send back.
737 send_pong (struct MeshTunnel3 *t, uint32_t challenge)
739 struct GNUNET_MESH_KX_Pong msg;
741 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s()\n", __FUNCTION__);
742 msg.header.size = htons (sizeof (msg));
743 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_PONG);
744 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
745 msg.nonce = challenge;
746 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
747 t_encrypt (t, &msg.nonce, &msg.nonce, sizeof (msg.nonce), msg.iv);
748 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
750 send_kx (t, &msg.header);
755 * Initiate a rekey with the remote peer.
757 * @param cls Closure (tunnel).
758 * @param tc TaskContext.
761 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
763 struct MeshTunnel3 *t = cls;
765 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
767 LOG (GNUNET_ERROR_TYPE_DEBUG, "Re-key Tunnel\n");
768 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
771 if (NULL == t->kx_ctx)
773 LOG (GNUNET_ERROR_TYPE_DEBUG, " new kx ctx\n");
774 t->kx_ctx = GNUNET_new (struct MeshTunnelKXCtx);
775 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
777 t->kx_ctx->d_key_old = t->d_key;
780 if (MESH_TUNNEL3_READY == t->state || MESH_TUNNEL3_REKEY == t->state)
783 t->state = MESH_TUNNEL3_REKEY;
785 else if (MESH_TUNNEL3_WAITING == t->state)
787 t->state = MESH_TUNNEL3_KEY_SENT;
791 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->state);
794 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
795 GNUNET_STRINGS_relative_time_to_string (REKEY_WAIT, GNUNET_YES));
796 t->rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_WAIT, &rekey_tunnel, t);
801 * Out ephemeral key has changed, create new session key on all tunnels.
803 * @param cls Closure (size of the hashmap).
804 * @param key Current public key.
805 * @param value Value in the hash map (tunnel).
807 * @return #GNUNET_YES, so we should continue to iterate,
810 rekey_iterator (void *cls,
811 const struct GNUNET_PeerIdentity *key,
814 struct MeshTunnel3 *t = value;
815 struct GNUNET_TIME_Relative delay;
819 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
822 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
823 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
824 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
831 * Create a new ephemeral key and key message, schedule next rekeying.
833 * @param cls Closure (unused).
834 * @param tc TaskContext.
837 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
839 struct GNUNET_TIME_Absolute time;
842 rekey_task = GNUNET_SCHEDULER_NO_TASK;
844 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
847 GNUNET_free_non_null (my_ephemeral_key);
848 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
850 time = GNUNET_TIME_absolute_get ();
851 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
852 time = GNUNET_TIME_absolute_add (time, rekey_period);
853 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
854 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
855 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
857 GNUNET_assert (GNUNET_OK ==
858 GNUNET_CRYPTO_eddsa_sign (my_private_key,
862 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
863 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
865 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
870 * Called only on shutdown, destroy every tunnel.
872 * @param cls Closure (unused).
873 * @param key Current public key.
874 * @param value Value in the hash map (tunnel).
876 * @return #GNUNET_YES, so we should continue to iterate,
879 destroy_iterator (void *cls,
880 const struct GNUNET_PeerIdentity *key,
883 struct MeshTunnel3 *t = value;
891 * Demultiplex data per channel and call appropriate channel handler.
893 * @param t Tunnel on which the data came.
894 * @param msg Data message.
895 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
896 * #GNUNET_YES if message is FWD on the respective channel (loopback)
897 * #GNUNET_NO if message is BCK on the respective channel (loopback)
898 * #GNUNET_SYSERR if message on a one-ended channel (remote)
901 handle_data (struct MeshTunnel3 *t,
902 const struct GNUNET_MESH_Data *msg,
905 struct MeshChannel *ch;
910 size = ntohs (msg->header.size);
912 sizeof (struct GNUNET_MESH_Data) +
913 sizeof (struct GNUNET_MessageHeader))
918 type = ntohs (msg->header.type);
919 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a %s message\n",
920 GNUNET_MESH_DEBUG_M2S (type));
921 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
922 GNUNET_MESH_DEBUG_M2S (ntohs (msg[1].header.type)));
925 ch = GMT_get_channel (t, ntohl (msg->chid));
928 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
930 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
935 GMT_change_state (t, MESH_TUNNEL3_READY);
936 GMCH_handle_data (ch, msg, fwd);
941 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
943 * @param t Tunnel on which the DATA ACK came.
944 * @param msg DATA ACK message.
945 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
946 * #GNUNET_YES if message is FWD on the respective channel (loopback)
947 * #GNUNET_NO if message is BCK on the respective channel (loopback)
948 * #GNUNET_SYSERR if message on a one-ended channel (remote)
951 handle_data_ack (struct MeshTunnel3 *t,
952 const struct GNUNET_MESH_DataACK *msg,
955 struct MeshChannel *ch;
959 size = ntohs (msg->header.size);
960 if (size != sizeof (struct GNUNET_MESH_DataACK))
967 ch = GMT_get_channel (t, ntohl (msg->chid));
970 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
972 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
977 GMCH_handle_data_ack (ch, msg, fwd);
982 * Handle channel create.
984 * @param t Tunnel on which the data came.
985 * @param msg Data message.
988 handle_ch_create (struct MeshTunnel3 *t,
989 const struct GNUNET_MESH_ChannelCreate *msg)
991 struct MeshChannel *ch;
995 size = ntohs (msg->header.size);
996 if (size != sizeof (struct GNUNET_MESH_ChannelCreate))
1003 ch = GMT_get_channel (t, ntohl (msg->chid));
1004 if (NULL != ch && ! GMT_is_loopback (t))
1006 /* Probably a retransmission, safe to ignore */
1007 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1011 ch = GMCH_handle_create (t, msg);
1014 GMT_add_channel (t, ch);
1020 * Handle channel NACK: check correctness and call channel handler for NACKs.
1022 * @param t Tunnel on which the NACK came.
1023 * @param msg NACK message.
1026 handle_ch_nack (struct MeshTunnel3 *t,
1027 const struct GNUNET_MESH_ChannelManage *msg)
1029 struct MeshChannel *ch;
1033 size = ntohs (msg->header.size);
1034 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
1041 ch = GMT_get_channel (t, ntohl (msg->chid));
1044 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1046 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1051 GMCH_handle_nack (ch);
1056 * Handle a CHANNEL ACK (SYNACK/ACK).
1058 * @param t Tunnel on which the CHANNEL ACK came.
1059 * @param msg CHANNEL ACK message.
1060 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1061 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1062 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1063 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1066 handle_ch_ack (struct MeshTunnel3 *t,
1067 const struct GNUNET_MESH_ChannelManage *msg,
1070 struct MeshChannel *ch;
1074 size = ntohs (msg->header.size);
1075 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
1082 ch = GMT_get_channel (t, ntohl (msg->chid));
1085 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1087 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1092 GMCH_handle_ack (ch, msg, fwd);
1098 * Handle a channel destruction message.
1100 * @param t Tunnel on which the message came.
1101 * @param msg Channel destroy message.
1102 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1103 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1104 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1105 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1108 handle_ch_destroy (struct MeshTunnel3 *t,
1109 const struct GNUNET_MESH_ChannelManage *msg,
1112 struct MeshChannel *ch;
1116 size = ntohs (msg->header.size);
1117 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
1124 ch = GMT_get_channel (t, ntohl (msg->chid));
1127 /* Probably a retransmission, safe to ignore */
1131 GMCH_handle_destroy (ch, msg, fwd);
1136 * The peer's ephemeral key has changed: update the symmetrical keys.
1138 * @param t Tunnel this message came on.
1139 * @param msg Key eXchange message.
1142 handle_ephemeral (struct MeshTunnel3 *t,
1143 const struct GNUNET_MESH_KX_Ephemeral *msg)
1145 struct GNUNET_HashCode km;
1146 LOG (GNUNET_ERROR_TYPE_DEBUG, " ephemeral key message\n");
1148 if (GNUNET_OK != check_ephemeral (t, msg))
1150 GNUNET_break_op (0);
1153 derive_key_material (&km, &msg->ephemeral_key);
1154 LOG (GNUNET_ERROR_TYPE_DEBUG, " km is %s\n", GNUNET_h2s (&km));
1155 derive_symmertic (&t->e_key, &my_full_id, GMP_get_id (t->peer), &km);
1156 derive_symmertic (&t->d_key, GMP_get_id (t->peer), &my_full_id, &km);
1157 if (MESH_TUNNEL3_KEY_SENT == t->state)
1159 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, send ping\n");
1161 t->state = MESH_TUNNEL3_REKEY;
1167 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
1168 * Answer with by retransmitting the challenge with the "opposite" key.
1170 * @param t Tunnel this message came on.
1171 * @param msg Key eXchange Ping message.
1174 handle_ping (struct MeshTunnel3 *t,
1175 const struct GNUNET_MESH_KX_Ping *msg)
1177 struct GNUNET_MESH_KX_Ping res;
1179 if (ntohs (msg->header.size) != sizeof (res))
1181 GNUNET_break_op (0);
1185 LOG (GNUNET_ERROR_TYPE_DEBUG, " ping message\n");
1186 t_decrypt (t, &res.target, &msg->target, ping_encryption_size (), msg->iv);
1187 if (0 != memcmp (&my_full_id, &res.target, sizeof (my_full_id)))
1189 GNUNET_break_op (0);
1190 LOG (GNUNET_ERROR_TYPE_DEBUG, " e got %u\n", msg->nonce);
1191 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg->target));
1192 LOG (GNUNET_ERROR_TYPE_DEBUG, " got %u\n", res.nonce);
1193 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&res.target));
1197 send_pong (t, res.nonce);
1202 * Peer has answer to our challenge.
1203 * If answer is successful, consider the key exchange finished and clean
1204 * up all related state.
1206 * @param t Tunnel this message came on.
1207 * @param msg Key eXchange Pong message.
1210 handle_pong (struct MeshTunnel3 *t,
1211 const struct GNUNET_MESH_KX_Pong *msg)
1215 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG received\n");
1216 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1218 GNUNET_break_op (0);
1221 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1223 if (challenge != t->kx_ctx->challenge)
1225 LOG (GNUNET_ERROR_TYPE_DEBUG,
1226 "Wrong PONG challenge: %u (e: %u). Expected: %u.\n",
1227 challenge, msg->nonce, t->kx_ctx->challenge);
1228 GNUNET_break_op (0);
1231 GNUNET_SCHEDULER_cancel (t->rekey_task);
1232 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1233 GNUNET_free (t->kx_ctx);
1235 t->state = MESH_TUNNEL3_READY;
1236 send_queued_data (t);
1241 * Demultiplex by message type and call appropriate handler for a message
1242 * towards a channel of a local tunnel.
1244 * @param t Tunnel this message came on.
1245 * @param msgh Message header.
1246 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1247 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1248 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1249 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1252 handle_decrypted (struct MeshTunnel3 *t,
1253 const struct GNUNET_MessageHeader *msgh,
1258 type = ntohs (msgh->type);
1259 LOG (GNUNET_ERROR_TYPE_DEBUG,
1260 "Got a %s message!\n",
1261 GNUNET_MESH_DEBUG_M2S (type));
1265 case GNUNET_MESSAGE_TYPE_MESH_DATA:
1266 /* Don't send hop ACK, wait for client to ACK */
1267 handle_data (t, (struct GNUNET_MESH_Data *) msgh, fwd);
1270 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
1271 handle_data_ack (t, (struct GNUNET_MESH_DataACK *) msgh, fwd);
1274 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
1275 handle_ch_create (t,
1276 (struct GNUNET_MESH_ChannelCreate *) msgh);
1279 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK:
1281 (struct GNUNET_MESH_ChannelManage *) msgh);
1284 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
1286 (struct GNUNET_MESH_ChannelManage *) msgh,
1290 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
1291 handle_ch_destroy (t,
1292 (struct GNUNET_MESH_ChannelManage *) msgh,
1297 GNUNET_break_op (0);
1298 LOG (GNUNET_ERROR_TYPE_DEBUG,
1299 "end-to-end message not known (%u)\n",
1300 ntohs (msgh->type));
1304 /******************************************************************************/
1305 /******************************** API ***********************************/
1306 /******************************************************************************/
1309 * Decrypt and demultiplex by message type. Call appropriate handler
1310 * for every message.
1312 * @param t Tunnel this message came on.
1313 * @param msg Encrypted message.
1316 GMT_handle_encrypted (struct MeshTunnel3 *t,
1317 const struct GNUNET_MESH_Encrypted *msg)
1319 size_t size = ntohs (msg->header.size);
1320 size_t payload_size = size - sizeof (struct GNUNET_MESH_Encrypted);
1321 size_t decrypted_size;
1322 char cbuf [payload_size];
1323 struct GNUNET_MessageHeader *msgh;
1326 decrypted_size = t_decrypt (t, cbuf, &msg[1], payload_size, msg->iv);
1328 while (off < decrypted_size)
1330 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
1331 handle_decrypted (t, msgh, GNUNET_SYSERR);
1332 off += ntohs (msgh->size);
1338 * Demultiplex an encapsulated KX message by message type.
1340 * @param t Tunnel on which the message came.
1341 * @param message Payload of KX message.
1344 GMT_handle_kx (struct MeshTunnel3 *t,
1345 const struct GNUNET_MessageHeader *message)
1349 type = ntohs (message->type);
1350 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
1353 case GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL:
1354 handle_ephemeral (t, (struct GNUNET_MESH_KX_Ephemeral *) message);
1357 case GNUNET_MESSAGE_TYPE_MESH_KX_PING:
1358 handle_ping (t, (struct GNUNET_MESH_KX_Ping *) message);
1361 case GNUNET_MESSAGE_TYPE_MESH_KX_PONG:
1362 handle_pong (t, (struct GNUNET_MESH_KX_Pong *) message);
1366 GNUNET_break_op (0);
1367 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
1373 * Initialize the tunnel subsystem.
1375 * @param c Configuration handle.
1376 * @param key ECC private key, to derive all other keys and do crypto.
1379 GMT_init (const struct GNUNET_CONFIGURATION_Handle *c,
1380 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
1382 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1384 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "DEFAULT_TTL",
1387 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1388 "MESH", "DEFAULT_TTL", "USING DEFAULT");
1392 GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REKEY_PERIOD",
1395 rekey_period = GNUNET_TIME_UNIT_DAYS;
1398 my_private_key = key;
1399 kx_msg.header.size = htons (sizeof (kx_msg));
1400 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL);
1401 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_MESH_KX);
1402 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
1403 kx_msg.origin_identity = my_full_id;
1404 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
1406 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
1411 * Shut down the tunnel subsystem.
1416 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
1418 GNUNET_SCHEDULER_cancel (rekey_task);
1419 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1421 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
1422 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
1429 * @param destination Peer this tunnel is towards.
1431 struct MeshTunnel3 *
1432 GMT_new (struct MeshPeer *destination)
1434 struct MeshTunnel3 *t;
1436 t = GNUNET_new (struct MeshTunnel3);
1438 t->peer = destination;
1441 GNUNET_CONTAINER_multipeermap_put (tunnels, GMP_get_id (destination), t,
1442 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
1453 * Change the tunnel state.
1455 * @param t Tunnel whose state to change.
1456 * @param state New state.
1459 GMT_change_state (struct MeshTunnel3* t, enum MeshTunnel3State state)
1463 LOG (GNUNET_ERROR_TYPE_DEBUG,
1464 "Tunnel %s state was %s\n",
1466 GMT_state2s (t->state));
1467 LOG (GNUNET_ERROR_TYPE_DEBUG,
1468 "Tunnel %s state is now %s\n",
1470 GMT_state2s (state));
1471 if (myid != GMP_get_short_id (t->peer) &&
1472 MESH_TUNNEL3_WAITING == t->state && MESH_TUNNEL3_READY == state)
1474 LOG (GNUNET_ERROR_TYPE_DEBUG, " triggered rekey\n");
1475 rekey_tunnel (t, NULL);
1476 LOG (GNUNET_ERROR_TYPE_DEBUG,
1477 "Tunnel %s state is now %s\n",
1479 GMT_state2s (t->state));
1485 if (MESH_TUNNEL3_READY == state && 3 <= GMT_count_connections (t))
1487 GMP_stop_search (t->peer);
1493 * Add a connection to a tunnel.
1496 * @param c Connection.
1499 GMT_add_connection (struct MeshTunnel3 *t, struct MeshConnection *c)
1501 struct MeshTConnection *aux;
1503 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1507 aux = GNUNET_new (struct MeshTConnection);
1509 GNUNET_CONTAINER_DLL_insert_tail (t->connection_head, t->connection_tail, aux);
1514 * Remove a connection from a tunnel.
1517 * @param c Connection.
1520 GMT_remove_connection (struct MeshTunnel3 *t, struct MeshConnection *c)
1522 struct MeshTConnection *aux;
1524 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1527 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
1535 * Add a channel to a tunnel.
1538 * @param ch Channel.
1541 GMT_add_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1543 struct MeshTChannel *aux;
1545 GNUNET_assert (NULL != ch);
1547 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
1549 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1551 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
1556 aux = GNUNET_new (struct MeshTChannel);
1558 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
1559 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
1564 * Remove a channel from a tunnel.
1567 * @param ch Channel.
1570 GMT_remove_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1572 struct MeshTChannel *aux;
1574 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
1575 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1579 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GMCH_2s (ch));
1580 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
1589 * Search for a channel by global ID.
1591 * @param t Tunnel containing the channel.
1592 * @param chid Public channel number.
1594 * @return channel handler, NULL if doesn't exist
1596 struct MeshChannel *
1597 GMT_get_channel (struct MeshTunnel3 *t, MESH_ChannelNumber chid)
1599 struct MeshTChannel *iter;
1604 for (iter = t->channel_head; NULL != iter; iter = iter->next)
1606 if (GMCH_get_id (iter->ch) == chid)
1610 return NULL == iter ? NULL : iter->ch;
1615 * Tunnel is empty: destroy it.
1617 * Notifies all connections about the destruction.
1619 * @param t Tunnel to destroy.
1622 GMT_destroy_empty (struct MeshTunnel3 *t)
1624 struct MeshTConnection *iter;
1626 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1628 GMC_send_destroy (iter->c);
1631 t->destroy = GNUNET_YES;
1636 * Destroy tunnel if empty (no more channels).
1638 * @param t Tunnel to destroy if empty.
1641 GMT_destroy_if_empty (struct MeshTunnel3 *t)
1643 if (1 < GMT_count_channels (t))
1646 GMT_destroy_empty (t);
1651 * Destroy the tunnel.
1653 * This function does not generate any warning traffic to clients or peers.
1656 * Cancel messages belonging to this tunnel queued to neighbors.
1657 * Free any allocated resources linked to the tunnel.
1659 * @param t The tunnel to destroy.
1662 GMT_destroy (struct MeshTunnel3 *t)
1664 struct MeshTConnection *iter_c;
1665 struct MeshTConnection *next_c;
1666 struct MeshTChannel *iter_ch;
1667 struct MeshTChannel *next_ch;
1672 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GMP_2s (t->peer));
1674 GNUNET_break (GNUNET_YES ==
1675 GNUNET_CONTAINER_multipeermap_remove (tunnels,
1676 GMP_get_id (t->peer), t));
1678 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
1680 next_c = iter_c->next;
1681 GMC_destroy (iter_c->c);
1683 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
1685 next_ch = iter_ch->next;
1686 GMCH_destroy (iter_ch->ch);
1687 /* Should only happen on shutdown, but it's ok. */
1690 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
1691 GMP_set_tunnel (t->peer, NULL);
1693 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1694 GNUNET_SCHEDULER_cancel (t->rekey_task);
1701 * @brief Use the given path for the tunnel.
1702 * Update the next and prev hops (and RCs).
1703 * (Re)start the path refresh in case the tunnel is locally owned.
1705 * @param t Tunnel to update.
1706 * @param p Path to use.
1708 * @return Connection created.
1710 struct MeshConnection *
1711 GMT_use_path (struct MeshTunnel3 *t, struct MeshPeerPath *p)
1713 struct MeshConnection *c;
1714 struct GNUNET_HashCode cid;
1715 unsigned int own_pos;
1717 if (NULL == t || NULL == p)
1723 for (own_pos = 0; own_pos < p->length; own_pos++)
1725 if (p->peers[own_pos] == myid)
1728 if (own_pos > p->length - 1)
1734 GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE, &cid);
1735 c = GMC_new (&cid, t, p, own_pos);
1736 GMT_add_connection (t, c);
1742 * Count established (ready) connections of a tunnel.
1744 * @param t Tunnel on which to count.
1746 * @return Number of connections.
1749 GMT_count_connections (struct MeshTunnel3 *t)
1751 struct MeshTConnection *iter;
1754 for (count = 0, iter = t->connection_head;
1756 iter = iter->next, count++);
1762 * Count channels of a tunnel.
1764 * @param t Tunnel on which to count.
1766 * @return Number of channels.
1769 GMT_count_channels (struct MeshTunnel3 *t)
1771 struct MeshTChannel *iter;
1774 for (count = 0, iter = t->channel_head;
1776 iter = iter->next, count++) /* skip */;
1783 * Get the state of a tunnel.
1787 * @return Tunnel's state.
1789 enum MeshTunnel3State
1790 GMT_get_state (struct MeshTunnel3 *t)
1795 return (enum MeshTunnel3State) -1;
1802 * Get the maximum buffer space for a tunnel towards a local client.
1806 * @return Biggest buffer space offered by any channel in the tunnel.
1809 GMT_get_channels_buffer (struct MeshTunnel3 *t)
1811 struct MeshTChannel *iter;
1812 unsigned int buffer;
1813 unsigned int ch_buf;
1815 if (NULL == t->channel_head)
1817 /* Probably getting buffer for a channel create/handshake. */
1822 for (iter = t->channel_head; NULL != iter; iter = iter->next)
1824 ch_buf = get_channel_buffer (iter);
1825 if (ch_buf > buffer)
1833 * Get the total buffer space for a tunnel for P2P traffic.
1837 * @return Buffer space offered by all connections in the tunnel.
1840 GMT_get_connections_buffer (struct MeshTunnel3 *t)
1842 struct MeshTConnection *iter;
1843 unsigned int buffer;
1845 iter = t->connection_head;
1847 while (NULL != iter)
1849 if (GMC_get_state (iter->c) != MESH_CONNECTION_READY)
1855 buffer += get_connection_buffer (iter);
1864 * Get the tunnel's destination.
1868 * @return ID of the destination peer.
1870 const struct GNUNET_PeerIdentity *
1871 GMT_get_destination (struct MeshTunnel3 *t)
1873 return GMP_get_id (t->peer);
1878 * Get the tunnel's next free global channel ID.
1882 * @return GID of a channel free to use.
1885 GMT_get_next_chid (struct MeshTunnel3 *t)
1887 MESH_ChannelNumber chid;
1889 while (NULL != GMT_get_channel (t, t->next_chid))
1891 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
1892 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
1894 chid = t->next_chid;
1895 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
1902 * Send ACK on one or more channels due to buffer in connections.
1904 * @param t Channel which has some free buffer space.
1907 GMT_unchoke_channels (struct MeshTunnel3 *t)
1909 struct MeshTChannel *iter;
1910 unsigned int buffer;
1911 unsigned int channels = GMT_count_channels (t);
1912 unsigned int choked_n;
1913 struct MeshChannel *choked[channels];
1915 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT_unchoke_channels on %s\n", GMT_2s (t));
1916 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
1917 if (NULL != t->channel_head)
1918 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
1920 /* Get buffer space */
1921 buffer = GMT_get_connections_buffer (t);
1927 /* Count and remember choked channels */
1929 for (iter = t->channel_head; NULL != iter; iter = iter->next)
1931 if (GNUNET_NO == get_channel_allowed (iter))
1933 choked[choked_n++] = iter->ch;
1937 /* Unchoke random channels */
1938 while (0 < buffer && 0 < choked_n)
1940 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1942 GMCH_allow_client (choked[r], GMCH_is_origin (choked[r], GNUNET_YES));
1945 choked[r] = choked[choked_n];
1951 * Send ACK on one or more connections due to buffer space to the client.
1953 * Iterates all connections of the tunnel and sends ACKs appropriately.
1958 GMT_send_connection_acks (struct MeshTunnel3 *t)
1960 struct MeshTConnection *iter;
1963 uint32_t allow_per_connection;
1965 unsigned int buffer;
1967 LOG (GNUNET_ERROR_TYPE_DEBUG,
1968 "Tunnel send connection ACKs on %s\n",
1977 buffer = GMT_get_channels_buffer (t);
1979 /* Count connections, how many messages are already allowed */
1980 cs = GMT_count_connections (t);
1981 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
1983 allowed += get_connection_allowed (iter);
1986 /* Make sure there is no overflow */
1987 if (allowed > buffer)
1992 /* Authorize connections to send more data */
1993 to_allow = buffer; /* - allowed; */
1995 for (iter = t->connection_head; NULL != iter && to_allow > 0; iter = iter->next)
1997 allow_per_connection = to_allow/cs;
1998 to_allow -= allow_per_connection;
2000 if (get_connection_allowed (iter) > 64 / 3)
2004 GMC_allow (iter->c, buffer, GMC_is_origin (iter->c, GNUNET_YES));
2007 GNUNET_break (to_allow == 0);
2012 * Callback called when a queued message is sent.
2014 * Calculates the average time and connection packet tracking.
2016 * @param cls Closure (TunnelQueue handle).
2017 * @param c Connection this message was on.
2018 * @param type Type of message sent.
2019 * @param fwd Was this a FWD going message?
2020 * @param size Size of the message.
2023 message_sent (void *cls,
2024 struct MeshConnection *c,
2025 struct MeshConnectionQueue *q,
2026 uint16_t type, int fwd, size_t size)
2028 struct MeshTunnel3Queue *qt = cls;
2030 GNUNET_assert (NULL != qt->cont);
2031 qt->cont (qt->cont_cls, GMC_get_tunnel (c), qt, type, size);
2037 * Cancel a previously sent message while it's in the queue.
2039 * ONLY can be called before the continuation given to the send function
2040 * is called. Once the continuation is called, the message is no longer in the
2043 * @param q Handle to the queue.
2046 GMT_cancel (struct MeshTunnel3Queue *q)
2049 /* message_sent() will be called and free q */
2053 * Sends an already built message on a tunnel, encrypting it and
2054 * choosing the best connection.
2056 * @param message Message to send. Function modifies it.
2057 * @param t Tunnel on which this message is transmitted.
2058 * @param ch Channel on which this message is transmitted.
2059 * @param fwd Is this a fwd message on @c ch?
2060 * @param cont Continuation to call once message is really sent.
2061 * @param cont_cls Closure for @c cont.
2063 * @return Handle to cancel message. NULL if @c cont is NULL.
2065 struct MeshTunnel3Queue *
2066 GMT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2067 struct MeshTunnel3 *t,
2068 struct MeshChannel *ch, int fwd,
2069 GMT_sent cont, void *cont_cls)
2071 struct MeshTunnel3Queue *q;
2072 struct MeshConnection *c;
2073 struct GNUNET_MESH_Encrypted *msg;
2074 size_t size = ntohs (message->size);
2075 size_t encrypted_size;
2076 char cbuf[sizeof (struct GNUNET_MESH_Encrypted) + size];
2080 if (MESH_TUNNEL3_READY != t->state)
2082 queue_data (t, ch, message);
2086 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GMT_2s (t));
2088 if (GMT_is_loopback (t))
2090 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
2091 handle_decrypted (t, message, fwd);
2092 /* FIXME: call cont? */
2093 return NULL; /* Already delivered, cannot cancel */
2096 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2097 msg = (struct GNUNET_MESH_Encrypted *) cbuf;
2098 msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED);
2100 encrypted_size = t_encrypt (t, &msg[1], message, size, iv);
2101 msg->header.size = htons (sizeof (struct GNUNET_MESH_Encrypted) + encrypted_size);
2102 c = tunnel_get_connection (t);
2105 GNUNET_break (GNUNET_YES == t->destroy);
2108 type = ntohs (message->type);
2111 case GNUNET_MESSAGE_TYPE_MESH_DATA:
2112 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
2113 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
2114 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
2115 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
2116 msg->cid = *GMC_get_id (c);
2117 msg->ttl = htonl (default_ttl);
2120 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
2121 GNUNET_MESH_DEBUG_M2S (type));
2125 fwd = GMC_is_origin (c, GNUNET_YES);
2129 (void) GMC_send_prebuilt_message (&msg->header, c, fwd, NULL, NULL);
2132 q = GNUNET_new (struct MeshTunnel3Queue); /* FIXME valgrind: leak*/
2133 q->q = GMC_send_prebuilt_message (&msg->header, c, fwd, &message_sent, q);
2135 q->cont_cls = cont_cls;
2141 * Is the tunnel directed towards the local peer?
2145 * @return #GNUNET_YES if it is loopback.
2148 GMT_is_loopback (const struct MeshTunnel3 *t)
2150 return (myid == GMP_get_short_id (t->peer));
2155 * Is the tunnel this path already?
2160 * @return #GNUNET_YES a connection uses this path.
2163 GMT_is_path_used (const struct MeshTunnel3 *t, const struct MeshPeerPath *p)
2165 struct MeshTConnection *iter;
2167 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2168 if (GMC_get_path (iter->c) == p)
2176 * Get a cost of a path for a tunnel considering existing connections.
2179 * @param path Candidate path.
2181 * @return Cost of the path (path length + number of overlapping nodes)
2184 GMT_get_path_cost (const struct MeshTunnel3 *t,
2185 const struct MeshPeerPath *path)
2187 struct MeshTConnection *iter;
2188 unsigned int overlap;
2196 GNUNET_assert (NULL != t);
2198 for (i = 0; i < path->length; i++)
2200 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2202 for (j = 0; j < GMC_get_path (iter->c)->length; j++)
2204 if (path->peers[i] == GMC_get_path (iter->c)->peers[j])
2212 return (path->length + overlap) * (path->score * -1);
2217 * Get the static string for the peer this tunnel is directed.
2221 * @return Static string the destination peer's ID.
2224 GMT_2s (const struct MeshTunnel3 *t)
2229 return GMP_2s (t->peer);