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 connectivity.
87 enum MeshTunnel3CState cstate;
90 * State of the tunnel encryption.
92 enum MeshTunnel3EState estate;
95 * Key eXchange context.
97 struct MeshTunnelKXCtx *kx_ctx;
100 * Encryption ("our") key.
102 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
105 * Decryption ("their") key.
107 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
110 * Task to start the rekey process.
112 GNUNET_SCHEDULER_TaskIdentifier rekey_task;
115 * Paths that are actively used to reach the destination peer.
117 struct MeshTConnection *connection_head;
118 struct MeshTConnection *connection_tail;
121 * Next connection number.
126 * Channels inside this tunnel.
128 struct MeshTChannel *channel_head;
129 struct MeshTChannel *channel_tail;
132 * Channel ID for the next created channel.
134 MESH_ChannelNumber next_chid;
137 * Destroy flag: if true, destroy on last message.
142 * Queued messages, to transmit once tunnel gets connected.
144 struct MeshTunnelDelayed *tq_head;
145 struct MeshTunnelDelayed *tq_tail;
150 * Struct used to save messages in a non-ready tunnel to send once connected.
152 struct MeshTunnelDelayed
157 struct MeshTunnelDelayed *next;
158 struct MeshTunnelDelayed *prev;
163 struct MeshTunnel3 *t;
166 * Tunnel queue given to the channel to cancel request. Update on send_queued.
168 struct MeshTunnel3Queue *tq;
173 /* struct GNUNET_MessageHeader *msg; */
178 * Handle for messages queued but not yet sent.
180 struct MeshTunnel3Queue
183 * Connection queue handle, to cancel if necessary.
185 struct MeshConnectionQueue *cq;
188 * Handle in case message hasn't been given to a connection yet.
190 struct MeshTunnelDelayed *tqd;
193 * Continuation to call once sent.
198 * Closure for @c cont.
204 /******************************************************************************/
205 /******************************* GLOBALS ***********************************/
206 /******************************************************************************/
209 * Global handle to the statistics service.
211 extern struct GNUNET_STATISTICS_Handle *stats;
214 * Local peer own ID (memory efficient handle).
216 extern GNUNET_PEER_Id myid;
219 * Local peer own ID (full value).
221 extern struct GNUNET_PeerIdentity my_full_id;
225 * Don't try to recover tunnels if shutting down.
227 extern int shutting_down;
231 * Set of all tunnels, in order to trigger a new exchange on rekey.
232 * Indexed by peer's ID.
234 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
237 * Default TTL for payload packets.
239 static unsigned long long default_ttl;
244 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
247 * Own ephemeral private key.
249 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
252 * Cached message used to perform a key exchange.
254 static struct GNUNET_MESH_KX_Ephemeral kx_msg;
257 * Task to generate a new ephemeral key.
259 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
264 static struct GNUNET_TIME_Relative rekey_period;
266 /******************************************************************************/
267 /******************************** STATIC ***********************************/
268 /******************************************************************************/
271 * Get string description for tunnel connectivity state.
273 * @param cs Tunnel state.
275 * @return String representation.
278 cstate2s (enum MeshTunnel3CState cs)
280 static char buf[128];
284 case MESH_TUNNEL3_NEW:
285 return "MESH_TUNNEL3_NEW";
286 case MESH_TUNNEL3_SEARCHING:
287 return "MESH_TUNNEL3_SEARCHING";
288 case MESH_TUNNEL3_WAITING:
289 return "MESH_TUNNEL3_WAITING";
290 case MESH_TUNNEL3_READY:
291 return "MESH_TUNNEL3_READY";
294 sprintf (buf, "%u (UNKNOWN STATE)", cs);
302 * Get string description for tunnel encryption state.
304 * @param es Tunnel state.
306 * @return String representation.
309 estate2s (enum MeshTunnel3EState es)
311 static char buf[128];
315 case MESH_TUNNEL3_KEY_UNINITIALIZED:
316 return "MESH_TUNNEL3_KEY_UNINITIALIZED";
317 case MESH_TUNNEL3_KEY_SENT:
318 return "MESH_TUNNEL3_KEY_SENT";
319 case MESH_TUNNEL3_KEY_PING:
320 return "MESH_TUNNEL3_KEY_PING";
321 case MESH_TUNNEL3_KEY_OK:
322 return "MESH_TUNNEL3_KEY_OK";
325 sprintf (buf, "%u (UNKNOWN STATE)", es);
333 * @brief Check if tunnel is ready to send traffic.
335 * Tunnel must be connected and with encryption correctly set up.
337 * @param t Tunnel to check.
339 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
342 is_ready (struct MeshTunnel3 *t)
344 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready: cs=%s, es=%s\n",
345 cstate2s (t->cstate), estate2s (t->estate));
346 return (MESH_TUNNEL3_READY == t->cstate
347 && MESH_TUNNEL3_KEY_OK == t->estate)
348 || GMT_is_loopback (t);
353 * Ephemeral key message purpose size.
355 * @return Size of the part of the ephemeral key message that must be signed.
358 ephemeral_purpose_size (void)
360 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
361 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
362 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
363 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
364 sizeof (struct GNUNET_PeerIdentity);
369 * Size of the encrypted part of a ping message.
371 * @return Size of the encrypted part of a ping message.
374 ping_encryption_size (void)
376 return sizeof (struct GNUNET_PeerIdentity) + sizeof (uint32_t);
381 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
383 * @param tch Tunnel's channel handle.
385 * @return Amount of messages the channel can still buffer towards the client.
388 get_channel_buffer (const struct MeshTChannel *tch)
392 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
393 fwd = GMCH_is_origin (tch->ch, GNUNET_YES);
395 return GMCH_get_buffer (tch->ch, fwd);
400 * Get the channel's allowance status.
402 * @param tch Tunnel's channel handle.
404 * @return #GNUNET_YES if we allowed the client to send data to us.
407 get_channel_allowed (const struct MeshTChannel *tch)
411 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
412 fwd = GMCH_is_origin (tch->ch, GNUNET_YES);
414 return GMCH_get_allowed (tch->ch, fwd);
419 * Get the connection's buffer.
421 * @param tc Tunnel's connection handle.
423 * @return Amount of messages the connection can still buffer.
426 get_connection_buffer (const struct MeshTConnection *tc)
430 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
431 fwd = GMC_is_origin (tc->c, GNUNET_YES);
433 return GMC_get_buffer (tc->c, fwd);
438 * Get the connection's allowance.
440 * @param tc Tunnel's connection handle.
442 * @return Amount of messages we have allowed the next peer to send us.
445 get_connection_allowed (const struct MeshTConnection *tc)
449 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
450 fwd = GMC_is_origin (tc->c, GNUNET_YES);
452 return GMC_get_allowed (tc->c, fwd);
457 * Check that a ephemeral key message s well formed and correctly signed.
459 * @param t Tunnel on which the message came.
460 * @param msg The ephemeral key message.
462 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
465 check_ephemeral (struct MeshTunnel3 *t,
466 const struct GNUNET_MESH_KX_Ephemeral *msg)
468 /* Check message size */
469 if (ntohs (msg->header.size) != sizeof (struct GNUNET_MESH_KX_Ephemeral))
470 return GNUNET_SYSERR;
472 /* Check signature size */
473 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
474 return GNUNET_SYSERR;
477 if (0 != memcmp (&msg->origin_identity,
478 GMP_get_id (t->peer),
479 sizeof (struct GNUNET_PeerIdentity)))
480 return GNUNET_SYSERR;
482 /* Check signature */
484 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_MESH_KX,
487 &msg->origin_identity.public_key))
488 return GNUNET_SYSERR;
495 * Encrypt data with the tunnel key.
497 * @param t Tunnel whose key to use.
498 * @param dst Destination for the encrypted data.
499 * @param src Source of the plaintext. Can overlap with @c dst.
500 * @param size Size of the plaintext.
501 * @param iv Initialization Vector to use.
504 t_encrypt (struct MeshTunnel3 *t,
505 void *dst, const void *src,
506 size_t size, uint32_t iv)
508 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
510 GNUNET_CRYPTO_symmetric_derive_iv (&siv, &t->e_key, &iv, sizeof (uint32_t), NULL);
511 return GNUNET_CRYPTO_symmetric_encrypt (src, size, &t->e_key, &siv, dst);
516 * Decrypt data with the tunnel key.
518 * @param t Tunnel whose key to use.
519 * @param dst Destination for the plaintext.
520 * @param src Source of the encrypted data. Can overlap with @c dst.
521 * @param size Size of the encrypted data.
522 * @param iv Initialization Vector to use.
525 t_decrypt (struct MeshTunnel3 *t,
526 void *dst, const void *src,
527 size_t size, uint32_t iv)
529 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
531 GNUNET_CRYPTO_symmetric_derive_iv (&siv, &t->d_key, &iv, sizeof (uint32_t), NULL);
532 return GNUNET_CRYPTO_symmetric_decrypt (src, size, &t->d_key, &siv, dst);
537 * Create key material by doing ECDH on the local and remote ephemeral keys.
539 * @param key_material Where to store the key material.
540 * @param ephemeral_key Peer's public ephemeral key.
543 derive_key_material (struct GNUNET_HashCode *key_material,
544 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
547 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
556 * Create a symmetic key from the identities of both ends and the key material
559 * @param key Destination for the generated key.
560 * @param sender ID of the peer that will encrypt with @c key.
561 * @param receiver ID of the peer that will decrypt with @c key.
562 * @param key_material Hash created with ECDH with the ephemeral keys.
565 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
566 const struct GNUNET_PeerIdentity *sender,
567 const struct GNUNET_PeerIdentity *receiver,
568 const struct GNUNET_HashCode *key_material)
570 const char salt[] = "MESH kx salt";
572 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
574 key_material, sizeof (struct GNUNET_HashCode),
575 sender, sizeof (struct GNUNET_PeerIdentity),
576 receiver, sizeof (struct GNUNET_PeerIdentity),
581 * Pick a connection on which send the next data message.
583 * @param t Tunnel on which to send the message.
585 * @return The connection on which to send the next message.
587 static struct MeshConnection *
588 tunnel_get_connection (struct MeshTunnel3 *t)
590 struct MeshTConnection *iter;
591 struct MeshConnection *best;
593 unsigned int lowest_q;
595 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GMP_2s (t->peer));
598 for (iter = t->connection_head; NULL != iter; iter = iter->next)
600 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
601 GMC_2s (iter->c), GMC_get_state (iter->c));
602 if (MESH_CONNECTION_READY == GMC_get_state (iter->c))
604 qn = GMC_get_qn (iter->c, GMC_is_origin (iter->c, GNUNET_YES));
605 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
613 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GMC_2s (best));
619 * Callback called when a queued message is sent.
621 * Calculates the average time and connection packet tracking.
623 * @param cls Closure (TunnelQueue handle).
624 * @param c Connection this message was on.
625 * @param q Connection queue handle (unused).
626 * @param type Type of message sent.
627 * @param fwd Was this a FWD going message?
628 * @param size Size of the message.
631 message_sent (void *cls,
632 struct MeshConnection *c,
633 struct MeshConnectionQueue *q,
634 uint16_t type, int fwd, size_t size)
636 struct MeshTunnel3Queue *qt = cls;
638 GNUNET_assert (NULL != qt->cont);
639 qt->cont (qt->cont_cls, GMC_get_tunnel (c), qt, type, size);
645 * Delete a queued message: either was sent or the channel was destroyed
646 * before the tunnel's key exchange had a chance to finish.
648 * @param tq Queue handle.
651 unqueue_data (struct MeshTunnelDelayed *tq)
653 GNUNET_CONTAINER_DLL_remove (tq->t->tq_head, tq->t->tq_tail, tq);
659 * Cache a message to be sent once tunnel is online.
661 * @param t Tunnel to hold the message.
662 * @param msg Message itself (copy will be made).
664 static struct MeshTunnelDelayed *
665 queue_data (struct MeshTunnel3 *t, const struct GNUNET_MessageHeader *msg)
667 struct MeshTunnelDelayed *tqd;
668 uint16_t size = ntohs (msg->size);
670 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GMT_2s (t));
672 if (GNUNET_YES == is_ready (t))
678 tqd = GNUNET_malloc (sizeof (struct MeshTunnelDelayed) + size);
681 memcpy (&tqd[1], msg, size);
682 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
689 * Sends an already built message on a tunnel, encrypting it and
690 * choosing the best connection.
692 * @param message Message to send. Function modifies it.
693 * @param t Tunnel on which this message is transmitted.
694 * @param force Force the tunnel to take the message (buffer overfill).
695 * @param cont Continuation to call once message is really sent.
696 * @param cont_cls Closure for @c cont.
697 * @param existing_q In case this a transmission of previously queued data,
698 * this should be TunnelQueue given to the client.
701 * @return Handle to cancel message. NULL if @c cont is NULL.
703 static struct MeshTunnel3Queue *
704 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
705 struct MeshTunnel3 *t, int force,
706 GMT_sent cont, void *cont_cls,
707 struct MeshTunnel3Queue *existing_q)
709 struct MeshTunnel3Queue *tq;
710 struct MeshConnection *c;
711 struct GNUNET_MESH_Encrypted *msg;
712 size_t size = ntohs (message->size);
713 char cbuf[sizeof (struct GNUNET_MESH_Encrypted) + size];
718 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GMT_2s (t));
720 if (GNUNET_NO == is_ready (t))
722 struct MeshTunnelDelayed *tqd;
723 /* A non null existing_q indicates sending of queued data.
724 * Should only happen after tunnel becomes ready.
726 GNUNET_assert (NULL == existing_q);
727 tqd = queue_data (t, message);
730 tq = GNUNET_new (struct MeshTunnel3Queue);
734 tq->cont_cls = cont_cls;
738 GNUNET_assert (GNUNET_NO == GMT_is_loopback (t));
740 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
741 msg = (struct GNUNET_MESH_Encrypted *) cbuf;
742 msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED);
744 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv) == size);
745 msg->header.size = htons (sizeof (struct GNUNET_MESH_Encrypted) + size);
746 c = tunnel_get_connection (t);
749 GNUNET_break (GNUNET_YES == t->destroy);
752 type = ntohs (message->type);
755 case GNUNET_MESSAGE_TYPE_MESH_DATA:
756 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
757 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
758 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
759 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
760 msg->cid = *GMC_get_id (c);
761 msg->ttl = htonl (default_ttl);
764 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
769 fwd = GMC_is_origin (c, GNUNET_YES);
773 (void) GMC_send_prebuilt_message (&msg->header, c, fwd, force, NULL, NULL);
776 if (NULL == existing_q)
778 tq = GNUNET_new (struct MeshTunnel3Queue); /* FIXME valgrind: leak*/
785 tq->cq = GMC_send_prebuilt_message (&msg->header, c, fwd, force,
788 tq->cont_cls = cont_cls;
795 * Send all cached messages that we can, tunnel is online.
797 * @param t Tunnel that holds the messages. Cannot be loopback.
800 send_queued_data (struct MeshTunnel3 *t)
802 struct MeshTunnelDelayed *tqd;
803 struct MeshTunnelDelayed *next;
806 LOG (GNUNET_ERROR_TYPE_DEBUG,
807 "GMT_send_queued_data on tunnel %s\n",
810 if (GMT_is_loopback (t))
816 if (GNUNET_NO == is_ready (t))
818 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
819 estate2s (t->estate), cstate2s (t->cstate));
823 room = GMT_get_connections_buffer (t);
824 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
825 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
826 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
828 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
831 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
833 NULL != tqd->tq ? tqd->tq->cont : NULL,
834 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
838 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT_send_queued_data end\n", GMP_2s (t->peer));
843 * Sends key exchange message on a tunnel, choosing the best connection.
844 * Should not be called on loopback tunnels.
846 * @param t Tunnel on which this message is transmitted.
847 * @param message Message to send. Function modifies it.
850 send_kx (struct MeshTunnel3 *t,
851 const struct GNUNET_MessageHeader *message)
853 struct MeshConnection *c;
854 struct GNUNET_MESH_KX *msg;
855 size_t size = ntohs (message->size);
856 char cbuf[sizeof (struct GNUNET_MESH_KX) + size];
860 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GMT_2s (t));
862 /* Avoid loopback. */
863 if (GMT_is_loopback (t))
865 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
870 /* Must have a connection. */
871 if (NULL == t->connection_head)
873 GNUNET_break (MESH_TUNNEL3_SEARCHING == t->cstate);
877 msg = (struct GNUNET_MESH_KX *) cbuf;
878 msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX);
879 msg->header.size = htons (sizeof (struct GNUNET_MESH_KX) + size);
880 c = tunnel_get_connection (t);
883 GNUNET_break (GNUNET_YES == t->destroy || MESH_TUNNEL3_READY != t->cstate);
886 type = ntohs (message->type);
889 case GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL:
890 case GNUNET_MESSAGE_TYPE_MESH_KX_PING:
891 case GNUNET_MESSAGE_TYPE_MESH_KX_PONG:
892 msg->reserved = htonl (0);
893 memcpy (&msg[1], message, size);
896 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
901 fwd = GMC_is_origin (t->connection_head->c, GNUNET_YES);
902 /* TODO save handle and cancel in case of a unneeded retransmission */
903 GMC_send_prebuilt_message (&msg->header, c, fwd, GNUNET_YES, NULL, NULL);
908 * Send the ephemeral key on a tunnel.
910 * @param t Tunnel on which to send the key.
913 send_ephemeral (struct MeshTunnel3 *t)
915 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s()\n", __FUNCTION__);
917 kx_msg.sender_status = htonl (t->estate);
918 send_kx (t, &kx_msg.header);
922 * Send a ping message on a tunnel.
924 * @param t Tunnel on which to send the ping.
927 send_ping (struct MeshTunnel3 *t)
929 struct GNUNET_MESH_KX_Ping msg;
931 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s()\n", __FUNCTION__);
932 msg.header.size = htons (sizeof (msg));
933 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_PING);
934 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
935 msg.target = *GMP_get_id (t->peer);
936 msg.nonce = t->kx_ctx->challenge;
938 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
939 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&msg.target));
940 t_encrypt (t, &msg.target, &msg.target, ping_encryption_size(), msg.iv);
941 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
942 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg.target));
944 send_kx (t, &msg.header);
949 * Send a pong message on a tunnel.
951 * @param t Tunnel on which to send the pong.
952 * @param challenge Value sent in the ping that we have to send back.
955 send_pong (struct MeshTunnel3 *t, uint32_t challenge)
957 struct GNUNET_MESH_KX_Pong msg;
959 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s()\n", __FUNCTION__);
960 msg.header.size = htons (sizeof (msg));
961 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_PONG);
962 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
963 msg.nonce = challenge;
964 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
965 t_encrypt (t, &msg.nonce, &msg.nonce, sizeof (msg.nonce), msg.iv);
966 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
968 send_kx (t, &msg.header);
973 * Initiate a rekey with the remote peer.
975 * @param cls Closure (tunnel).
976 * @param tc TaskContext.
979 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
981 struct MeshTunnel3 *t = cls;
983 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
985 LOG (GNUNET_ERROR_TYPE_DEBUG, "Re-key Tunnel\n");
986 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
989 if (NULL == t->kx_ctx)
991 LOG (GNUNET_ERROR_TYPE_DEBUG, " new kx ctx\n");
992 t->kx_ctx = GNUNET_new (struct MeshTunnelKXCtx);
993 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
995 t->kx_ctx->d_key_old = t->d_key;
1000 case MESH_TUNNEL3_KEY_UNINITIALIZED:
1001 t->estate = MESH_TUNNEL3_KEY_SENT;
1003 case MESH_TUNNEL3_KEY_SENT:
1005 case MESH_TUNNEL3_KEY_PING:
1006 case MESH_TUNNEL3_KEY_OK:
1008 t->estate = MESH_TUNNEL3_KEY_PING;
1011 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1014 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1015 GNUNET_STRINGS_relative_time_to_string (REKEY_WAIT, GNUNET_YES));
1016 t->rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_WAIT, &rekey_tunnel, t);
1021 * Out ephemeral key has changed, create new session key on all tunnels.
1023 * @param cls Closure (size of the hashmap).
1024 * @param key Current public key.
1025 * @param value Value in the hash map (tunnel).
1027 * @return #GNUNET_YES, so we should continue to iterate,
1030 rekey_iterator (void *cls,
1031 const struct GNUNET_PeerIdentity *key,
1034 struct MeshTunnel3 *t = value;
1035 struct GNUNET_TIME_Relative delay;
1036 long n = (long) cls;
1039 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1042 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1043 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1044 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1051 * Create a new ephemeral key and key message, schedule next rekeying.
1053 * @param cls Closure (unused).
1054 * @param tc TaskContext.
1057 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1059 struct GNUNET_TIME_Absolute time;
1062 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1064 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1067 GNUNET_free_non_null (my_ephemeral_key);
1068 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1070 time = GNUNET_TIME_absolute_get ();
1071 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1072 time = GNUNET_TIME_absolute_add (time, rekey_period);
1073 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1074 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1075 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1077 GNUNET_assert (GNUNET_OK ==
1078 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1080 &kx_msg.signature));
1082 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1083 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1085 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1090 * Called only on shutdown, destroy every tunnel.
1092 * @param cls Closure (unused).
1093 * @param key Current public key.
1094 * @param value Value in the hash map (tunnel).
1096 * @return #GNUNET_YES, so we should continue to iterate,
1099 destroy_iterator (void *cls,
1100 const struct GNUNET_PeerIdentity *key,
1103 struct MeshTunnel3 *t = value;
1111 * Demultiplex data per channel and call appropriate channel handler.
1113 * @param t Tunnel on which the data came.
1114 * @param msg Data message.
1115 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1116 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1117 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1118 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1121 handle_data (struct MeshTunnel3 *t,
1122 const struct GNUNET_MESH_Data *msg,
1125 struct MeshChannel *ch;
1129 size = ntohs (msg->header.size);
1131 sizeof (struct GNUNET_MESH_Data) +
1132 sizeof (struct GNUNET_MessageHeader))
1137 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1138 GM_m2s (ntohs (msg[1].header.type)));
1141 ch = GMT_get_channel (t, ntohl (msg->chid));
1144 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1146 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1151 GMCH_handle_data (ch, msg, fwd);
1156 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1158 * @param t Tunnel on which the DATA ACK came.
1159 * @param msg DATA ACK message.
1160 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1161 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1162 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1163 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1166 handle_data_ack (struct MeshTunnel3 *t,
1167 const struct GNUNET_MESH_DataACK *msg,
1170 struct MeshChannel *ch;
1174 size = ntohs (msg->header.size);
1175 if (size != sizeof (struct GNUNET_MESH_DataACK))
1182 ch = GMT_get_channel (t, ntohl (msg->chid));
1185 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1187 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1192 GMCH_handle_data_ack (ch, msg, fwd);
1197 * Handle channel create.
1199 * @param t Tunnel on which the data came.
1200 * @param msg Data message.
1203 handle_ch_create (struct MeshTunnel3 *t,
1204 const struct GNUNET_MESH_ChannelCreate *msg)
1206 struct MeshChannel *ch;
1210 size = ntohs (msg->header.size);
1211 if (size != sizeof (struct GNUNET_MESH_ChannelCreate))
1218 ch = GMT_get_channel (t, ntohl (msg->chid));
1219 if (NULL != ch && ! GMT_is_loopback (t))
1221 /* Probably a retransmission, safe to ignore */
1222 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1226 ch = GMCH_handle_create (t, msg);
1229 GMT_add_channel (t, ch);
1235 * Handle channel NACK: check correctness and call channel handler for NACKs.
1237 * @param t Tunnel on which the NACK came.
1238 * @param msg NACK message.
1241 handle_ch_nack (struct MeshTunnel3 *t,
1242 const struct GNUNET_MESH_ChannelManage *msg)
1244 struct MeshChannel *ch;
1248 size = ntohs (msg->header.size);
1249 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
1256 ch = GMT_get_channel (t, ntohl (msg->chid));
1259 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1261 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1266 GMCH_handle_nack (ch);
1271 * Handle a CHANNEL ACK (SYNACK/ACK).
1273 * @param t Tunnel on which the CHANNEL ACK came.
1274 * @param msg CHANNEL ACK message.
1275 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1276 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1277 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1278 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1281 handle_ch_ack (struct MeshTunnel3 *t,
1282 const struct GNUNET_MESH_ChannelManage *msg,
1285 struct MeshChannel *ch;
1289 size = ntohs (msg->header.size);
1290 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
1297 ch = GMT_get_channel (t, ntohl (msg->chid));
1300 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1302 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1307 GMCH_handle_ack (ch, msg, fwd);
1313 * Handle a channel destruction message.
1315 * @param t Tunnel on which the message came.
1316 * @param msg Channel destroy message.
1317 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1318 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1319 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1320 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1323 handle_ch_destroy (struct MeshTunnel3 *t,
1324 const struct GNUNET_MESH_ChannelManage *msg,
1327 struct MeshChannel *ch;
1331 size = ntohs (msg->header.size);
1332 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
1339 ch = GMT_get_channel (t, ntohl (msg->chid));
1342 /* Probably a retransmission, safe to ignore */
1346 GMCH_handle_destroy (ch, msg, fwd);
1351 * The peer's ephemeral key has changed: update the symmetrical keys.
1353 * @param t Tunnel this message came on.
1354 * @param msg Key eXchange message.
1357 handle_ephemeral (struct MeshTunnel3 *t,
1358 const struct GNUNET_MESH_KX_Ephemeral *msg)
1360 struct GNUNET_HashCode km;
1361 LOG (GNUNET_ERROR_TYPE_DEBUG, " ephemeral key message\n");
1363 if (GNUNET_OK != check_ephemeral (t, msg))
1365 GNUNET_break_op (0);
1368 derive_key_material (&km, &msg->ephemeral_key);
1369 LOG (GNUNET_ERROR_TYPE_DEBUG, " km is %s\n", GNUNET_h2s (&km));
1370 derive_symmertic (&t->e_key, &my_full_id, GMP_get_id (t->peer), &km);
1371 derive_symmertic (&t->d_key, GMP_get_id (t->peer), &my_full_id, &km);
1372 if (MESH_TUNNEL3_KEY_SENT == t->estate)
1374 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, send ping\n");
1376 t->estate = MESH_TUNNEL3_KEY_PING;
1382 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
1383 * Answer with by retransmitting the challenge with the "opposite" key.
1385 * @param t Tunnel this message came on.
1386 * @param msg Key eXchange Ping message.
1389 handle_ping (struct MeshTunnel3 *t,
1390 const struct GNUNET_MESH_KX_Ping *msg)
1392 struct GNUNET_MESH_KX_Ping res;
1394 if (ntohs (msg->header.size) != sizeof (res))
1396 GNUNET_break_op (0);
1400 LOG (GNUNET_ERROR_TYPE_DEBUG, " ping message\n");
1401 t_decrypt (t, &res.target, &msg->target, ping_encryption_size (), msg->iv);
1402 if (0 != memcmp (&my_full_id, &res.target, sizeof (my_full_id)))
1404 GNUNET_break_op (0);
1405 LOG (GNUNET_ERROR_TYPE_DEBUG, " e got %u\n", msg->nonce);
1406 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg->target));
1407 LOG (GNUNET_ERROR_TYPE_DEBUG, " got %u\n", res.nonce);
1408 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&res.target));
1412 send_pong (t, res.nonce);
1417 * Peer has answer to our challenge.
1418 * If answer is successful, consider the key exchange finished and clean
1419 * up all related state.
1421 * @param t Tunnel this message came on.
1422 * @param msg Key eXchange Pong message.
1425 handle_pong (struct MeshTunnel3 *t,
1426 const struct GNUNET_MESH_KX_Pong *msg)
1430 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG received\n");
1431 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1433 GNUNET_break_op (0);
1436 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1438 if (challenge != t->kx_ctx->challenge)
1440 LOG (GNUNET_ERROR_TYPE_DEBUG,
1441 "Wrong PONG challenge: %u (e: %u). Expected: %u.\n",
1442 challenge, msg->nonce, t->kx_ctx->challenge);
1443 GNUNET_break_op (0);
1446 GNUNET_SCHEDULER_cancel (t->rekey_task);
1447 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1448 GNUNET_free (t->kx_ctx);
1450 GMT_change_estate (t, MESH_TUNNEL3_KEY_OK);
1455 * Demultiplex by message type and call appropriate handler for a message
1456 * towards a channel of a local tunnel.
1458 * @param t Tunnel this message came on.
1459 * @param msgh Message header.
1460 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1461 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1462 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1463 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1466 handle_decrypted (struct MeshTunnel3 *t,
1467 const struct GNUNET_MessageHeader *msgh,
1472 type = ntohs (msgh->type);
1473 LOG (GNUNET_ERROR_TYPE_DEBUG,
1474 "Got a %s message!\n",
1479 case GNUNET_MESSAGE_TYPE_MESH_DATA:
1480 /* Don't send hop ACK, wait for client to ACK */
1481 handle_data (t, (struct GNUNET_MESH_Data *) msgh, fwd);
1484 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
1485 handle_data_ack (t, (struct GNUNET_MESH_DataACK *) msgh, fwd);
1488 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
1489 handle_ch_create (t,
1490 (struct GNUNET_MESH_ChannelCreate *) msgh);
1493 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK:
1495 (struct GNUNET_MESH_ChannelManage *) msgh);
1498 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
1500 (struct GNUNET_MESH_ChannelManage *) msgh,
1504 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
1505 handle_ch_destroy (t,
1506 (struct GNUNET_MESH_ChannelManage *) msgh,
1511 GNUNET_break_op (0);
1512 LOG (GNUNET_ERROR_TYPE_DEBUG,
1513 "end-to-end message not known (%u)\n",
1514 ntohs (msgh->type));
1518 /******************************************************************************/
1519 /******************************** API ***********************************/
1520 /******************************************************************************/
1523 * Decrypt and demultiplex by message type. Call appropriate handler
1524 * for every message.
1526 * @param t Tunnel this message came on.
1527 * @param msg Encrypted message.
1530 GMT_handle_encrypted (struct MeshTunnel3 *t,
1531 const struct GNUNET_MESH_Encrypted *msg)
1533 size_t size = ntohs (msg->header.size);
1534 size_t payload_size = size - sizeof (struct GNUNET_MESH_Encrypted);
1535 size_t decrypted_size;
1536 char cbuf [payload_size];
1537 struct GNUNET_MessageHeader *msgh;
1540 decrypted_size = t_decrypt (t, cbuf, &msg[1], payload_size, msg->iv);
1542 while (off < decrypted_size)
1544 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
1545 handle_decrypted (t, msgh, GNUNET_SYSERR);
1546 off += ntohs (msgh->size);
1552 * Demultiplex an encapsulated KX message by message type.
1554 * @param t Tunnel on which the message came.
1555 * @param message Payload of KX message.
1558 GMT_handle_kx (struct MeshTunnel3 *t,
1559 const struct GNUNET_MessageHeader *message)
1563 type = ntohs (message->type);
1564 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
1567 case GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL:
1568 handle_ephemeral (t, (struct GNUNET_MESH_KX_Ephemeral *) message);
1571 case GNUNET_MESSAGE_TYPE_MESH_KX_PING:
1572 handle_ping (t, (struct GNUNET_MESH_KX_Ping *) message);
1575 case GNUNET_MESSAGE_TYPE_MESH_KX_PONG:
1576 handle_pong (t, (struct GNUNET_MESH_KX_Pong *) message);
1580 GNUNET_break_op (0);
1581 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
1587 * Initialize the tunnel subsystem.
1589 * @param c Configuration handle.
1590 * @param key ECC private key, to derive all other keys and do crypto.
1593 GMT_init (const struct GNUNET_CONFIGURATION_Handle *c,
1594 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
1596 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1598 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "DEFAULT_TTL",
1601 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1602 "MESH", "DEFAULT_TTL", "USING DEFAULT");
1606 GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REKEY_PERIOD",
1609 rekey_period = GNUNET_TIME_UNIT_DAYS;
1612 my_private_key = key;
1613 kx_msg.header.size = htons (sizeof (kx_msg));
1614 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL);
1615 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_MESH_KX);
1616 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
1617 kx_msg.origin_identity = my_full_id;
1618 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
1620 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
1625 * Shut down the tunnel subsystem.
1630 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
1632 GNUNET_SCHEDULER_cancel (rekey_task);
1633 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1635 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
1636 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
1643 * @param destination Peer this tunnel is towards.
1645 struct MeshTunnel3 *
1646 GMT_new (struct MeshPeer *destination)
1648 struct MeshTunnel3 *t;
1650 t = GNUNET_new (struct MeshTunnel3);
1652 t->peer = destination;
1655 GNUNET_CONTAINER_multipeermap_put (tunnels, GMP_get_id (destination), t,
1656 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
1667 * Change the tunnel's connection state.
1669 * @param t Tunnel whose connection state to change.
1670 * @param cstate New connection state.
1673 GMT_change_cstate (struct MeshTunnel3* t, enum MeshTunnel3CState cstate)
1677 LOG (GNUNET_ERROR_TYPE_DEBUG,
1678 "Tunnel %s cstate was %s\n",
1679 GMP_2s (t->peer), cstate2s (t->cstate));
1680 LOG (GNUNET_ERROR_TYPE_DEBUG,
1681 "Tunnel %s cstate is now %s\n",
1682 GMP_2s (t->peer), cstate2s (cstate));
1683 if (myid != GMP_get_short_id (t->peer) &&
1684 MESH_TUNNEL3_READY != t->cstate &&
1685 MESH_TUNNEL3_READY == cstate)
1688 if (MESH_TUNNEL3_KEY_OK == t->estate)
1690 LOG (GNUNET_ERROR_TYPE_DEBUG, " triggered send queued data\n");
1691 send_queued_data (t);
1693 else if (MESH_TUNNEL3_KEY_UNINITIALIZED == t->estate)
1695 LOG (GNUNET_ERROR_TYPE_DEBUG, " triggered rekey\n");
1696 rekey_tunnel (t, NULL);
1701 if (MESH_TUNNEL3_READY == cstate && 3 <= GMT_count_connections (t))
1703 GMP_stop_search (t->peer);
1708 * Change the tunnel encryption state.
1710 * @param t Tunnel whose encryption state to change.
1711 * @param state New encryption state.
1714 GMT_change_estate (struct MeshTunnel3* t, enum MeshTunnel3EState state)
1718 LOG (GNUNET_ERROR_TYPE_DEBUG,
1719 "Tunnel %s estate was %s\n",
1720 GMP_2s (t->peer), estate2s (t->estate));
1721 LOG (GNUNET_ERROR_TYPE_DEBUG,
1722 "Tunnel %s estate is now %s\n",
1723 GMP_2s (t->peer), estate2s (state));
1724 if (myid != GMP_get_short_id (t->peer) &&
1725 MESH_TUNNEL3_KEY_OK != t->estate && MESH_TUNNEL3_KEY_OK == state)
1728 send_queued_data (t);
1736 * Add a connection to a tunnel.
1739 * @param c Connection.
1742 GMT_add_connection (struct MeshTunnel3 *t, struct MeshConnection *c)
1744 struct MeshTConnection *aux;
1746 GNUNET_assert (NULL != c);
1748 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1752 aux = GNUNET_new (struct MeshTConnection);
1754 GNUNET_CONTAINER_DLL_insert_tail (t->connection_head, t->connection_tail, aux);
1759 * Mark a path as no longer valid for this tunnel: has been tried and failed.
1761 * @param t Tunnel to update.
1762 * @param path Invalid path to remove. Is destroyed after removal.
1765 GMT_remove_path (struct MeshTunnel3 *t, struct MeshPeerPath *path)
1767 GMP_remove_path (t->peer, path);
1772 * Remove a connection from a tunnel.
1775 * @param c Connection.
1778 GMT_remove_connection (struct MeshTunnel3 *t,
1779 struct MeshConnection *c)
1781 struct MeshTConnection *aux;
1782 struct MeshTConnection *next;
1784 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
1785 GMC_2s (c), GMT_2s (t));
1786 for (aux = t->connection_head; aux != NULL; aux = next)
1791 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
1796 /* Start new connections if needed */
1797 if (NULL == t->connection_head
1798 && GNUNET_NO == t->destroy
1799 && GNUNET_NO == shutting_down)
1801 LOG (GNUNET_ERROR_TYPE_DEBUG, " no more connections\n");
1802 GMP_connect (t->peer);
1803 t->cstate = MESH_TUNNEL3_SEARCHING;
1807 /* If not marked as ready, no change is needed */
1808 if (MESH_TUNNEL3_READY != t->cstate)
1811 /* Check if any connection is ready to maintaing cstate */
1812 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1813 if (MESH_CONNECTION_READY == GMC_get_state (aux->c))
1816 t->cstate = MESH_TUNNEL3_WAITING;
1821 * Add a channel to a tunnel.
1824 * @param ch Channel.
1827 GMT_add_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1829 struct MeshTChannel *aux;
1831 GNUNET_assert (NULL != ch);
1833 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
1835 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1837 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
1842 aux = GNUNET_new (struct MeshTChannel);
1844 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
1845 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
1847 if (GNUNET_YES == t->destroy)
1849 t->destroy = GNUNET_NO;
1850 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
1856 * Remove a channel from a tunnel.
1859 * @param ch Channel.
1862 GMT_remove_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1864 struct MeshTChannel *aux;
1866 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
1867 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1871 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GMCH_2s (ch));
1872 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
1881 * Search for a channel by global ID.
1883 * @param t Tunnel containing the channel.
1884 * @param chid Public channel number.
1886 * @return channel handler, NULL if doesn't exist
1888 struct MeshChannel *
1889 GMT_get_channel (struct MeshTunnel3 *t, MESH_ChannelNumber chid)
1891 struct MeshTChannel *iter;
1896 for (iter = t->channel_head; NULL != iter; iter = iter->next)
1898 if (GMCH_get_id (iter->ch) == chid)
1902 return NULL == iter ? NULL : iter->ch;
1907 * Tunnel is empty: destroy it.
1909 * Notifies all connections about the destruction.
1911 * @param t Tunnel to destroy.
1914 GMT_destroy_empty (struct MeshTunnel3 *t)
1916 struct MeshTConnection *iter;
1918 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel empty: destroying scheduled\n");
1919 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1921 GMC_send_destroy (iter->c);
1924 t->cstate = MESH_TUNNEL3_NEW;
1925 t->destroy = GNUNET_YES;
1930 * Destroy tunnel if empty (no more channels).
1932 * @param t Tunnel to destroy if empty.
1935 GMT_destroy_if_empty (struct MeshTunnel3 *t)
1937 if (1 < GMT_count_channels (t))
1940 GMT_destroy_empty (t);
1945 * Destroy the tunnel.
1947 * This function does not generate any warning traffic to clients or peers.
1950 * Cancel messages belonging to this tunnel queued to neighbors.
1951 * Free any allocated resources linked to the tunnel.
1953 * @param t The tunnel to destroy.
1956 GMT_destroy (struct MeshTunnel3 *t)
1958 struct MeshTConnection *iter_c;
1959 struct MeshTConnection *next_c;
1960 struct MeshTChannel *iter_ch;
1961 struct MeshTChannel *next_ch;
1968 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GMP_2s (t->peer));
1970 GNUNET_break (GNUNET_YES ==
1971 GNUNET_CONTAINER_multipeermap_remove (tunnels,
1972 GMP_get_id (t->peer), t));
1974 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
1976 next_c = iter_c->next;
1977 GMC_destroy (iter_c->c);
1979 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
1981 next_ch = iter_ch->next;
1982 GMCH_destroy (iter_ch->ch);
1983 /* Should only happen on shutdown, but it's ok. */
1986 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
1987 GMP_set_tunnel (t->peer, NULL);
1989 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1990 GNUNET_SCHEDULER_cancel (t->rekey_task);
1997 * @brief Use the given path for the tunnel.
1998 * Update the next and prev hops (and RCs).
1999 * (Re)start the path refresh in case the tunnel is locally owned.
2001 * @param t Tunnel to update.
2002 * @param p Path to use.
2004 * @return Connection created.
2006 struct MeshConnection *
2007 GMT_use_path (struct MeshTunnel3 *t, struct MeshPeerPath *p)
2009 struct MeshConnection *c;
2010 struct GNUNET_HashCode cid;
2011 unsigned int own_pos;
2013 if (NULL == t || NULL == p)
2019 for (own_pos = 0; own_pos < p->length; own_pos++)
2021 if (p->peers[own_pos] == myid)
2024 if (own_pos > p->length - 1)
2026 GNUNET_break_op (0);
2030 GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE, &cid);
2031 c = GMC_new (&cid, t, p, own_pos);
2034 /* Path was flawed */
2037 GMT_add_connection (t, c);
2043 * Count established (ready) connections of a tunnel.
2045 * @param t Tunnel on which to count.
2047 * @return Number of connections.
2050 GMT_count_connections (struct MeshTunnel3 *t)
2052 struct MeshTConnection *iter;
2055 for (count = 0, iter = t->connection_head;
2057 iter = iter->next, count++);
2063 * Count channels of a tunnel.
2065 * @param t Tunnel on which to count.
2067 * @return Number of channels.
2070 GMT_count_channels (struct MeshTunnel3 *t)
2072 struct MeshTChannel *iter;
2075 for (count = 0, iter = t->channel_head;
2077 iter = iter->next, count++) /* skip */;
2084 * Get the connectivity state of a tunnel.
2088 * @return Tunnel's connectivity state.
2090 enum MeshTunnel3CState
2091 GMT_get_cstate (struct MeshTunnel3 *t)
2096 return (enum MeshTunnel3CState) -1;
2103 * Get the maximum buffer space for a tunnel towards a local client.
2107 * @return Biggest buffer space offered by any channel in the tunnel.
2110 GMT_get_channels_buffer (struct MeshTunnel3 *t)
2112 struct MeshTChannel *iter;
2113 unsigned int buffer;
2114 unsigned int ch_buf;
2116 if (NULL == t->channel_head)
2118 /* Probably getting buffer for a channel create/handshake. */
2123 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2125 ch_buf = get_channel_buffer (iter);
2126 if (ch_buf > buffer)
2134 * Get the total buffer space for a tunnel for P2P traffic.
2138 * @return Buffer space offered by all connections in the tunnel.
2141 GMT_get_connections_buffer (struct MeshTunnel3 *t)
2143 struct MeshTConnection *iter;
2144 unsigned int buffer;
2147 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2149 if (GMC_get_state (iter->c) != MESH_CONNECTION_READY)
2153 buffer += get_connection_buffer (iter);
2161 * Get the tunnel's destination.
2165 * @return ID of the destination peer.
2167 const struct GNUNET_PeerIdentity *
2168 GMT_get_destination (struct MeshTunnel3 *t)
2170 return GMP_get_id (t->peer);
2175 * Get the tunnel's next free global channel ID.
2179 * @return GID of a channel free to use.
2182 GMT_get_next_chid (struct MeshTunnel3 *t)
2184 MESH_ChannelNumber chid;
2185 MESH_ChannelNumber mask;
2188 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2189 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2190 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2192 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GMP_get_id (t->peer));
2198 while (NULL != GMT_get_channel (t, t->next_chid))
2200 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2201 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
2202 t->next_chid |= mask;
2204 chid = t->next_chid;
2205 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
2206 t->next_chid |= mask;
2213 * Send ACK on one or more channels due to buffer in connections.
2215 * @param t Channel which has some free buffer space.
2218 GMT_unchoke_channels (struct MeshTunnel3 *t)
2220 struct MeshTChannel *iter;
2221 unsigned int buffer;
2222 unsigned int channels = GMT_count_channels (t);
2223 unsigned int choked_n;
2224 struct MeshChannel *choked[channels];
2226 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT_unchoke_channels on %s\n", GMT_2s (t));
2227 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
2228 if (NULL != t->channel_head)
2229 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
2231 /* Get buffer space */
2232 buffer = GMT_get_connections_buffer (t);
2238 /* Count and remember choked channels */
2240 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2242 if (GNUNET_NO == get_channel_allowed (iter))
2244 choked[choked_n++] = iter->ch;
2248 /* Unchoke random channels */
2249 while (0 < buffer && 0 < choked_n)
2251 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
2253 GMCH_allow_client (choked[r], GMCH_is_origin (choked[r], GNUNET_YES));
2256 choked[r] = choked[choked_n];
2262 * Send ACK on one or more connections due to buffer space to the client.
2264 * Iterates all connections of the tunnel and sends ACKs appropriately.
2269 GMT_send_connection_acks (struct MeshTunnel3 *t)
2271 struct MeshTConnection *iter;
2274 uint32_t allow_per_connection;
2276 unsigned int buffer;
2278 LOG (GNUNET_ERROR_TYPE_DEBUG,
2279 "Tunnel send connection ACKs on %s\n",
2288 buffer = GMT_get_channels_buffer (t);
2290 /* Count connections, how many messages are already allowed */
2291 cs = GMT_count_connections (t);
2292 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2294 allowed += get_connection_allowed (iter);
2297 /* Make sure there is no overflow */
2298 if (allowed > buffer)
2303 /* Authorize connections to send more data */
2304 to_allow = buffer; /* - allowed; */
2306 for (iter = t->connection_head; NULL != iter && to_allow > 0; iter = iter->next)
2308 allow_per_connection = to_allow/cs;
2309 to_allow -= allow_per_connection;
2311 if (get_connection_allowed (iter) > 64 / 3)
2315 GMC_allow (iter->c, buffer, GMC_is_origin (iter->c, GNUNET_YES));
2318 GNUNET_break (to_allow == 0);
2323 * Cancel a previously sent message while it's in the queue.
2325 * ONLY can be called before the continuation given to the send function
2326 * is called. Once the continuation is called, the message is no longer in the
2329 * @param q Handle to the queue.
2332 GMT_cancel (struct MeshTunnel3Queue *q)
2337 /* message_sent() will be called and free q */
2339 else if (NULL != q->tqd)
2341 unqueue_data (q->tqd);
2351 * Sends an already built message on a tunnel, encrypting it and
2352 * choosing the best connection.
2354 * @param message Message to send. Function modifies it.
2355 * @param t Tunnel on which this message is transmitted.
2356 * @param force Force the tunnel to take the message (buffer overfill).
2357 * @param cont Continuation to call once message is really sent.
2358 * @param cont_cls Closure for @c cont.
2360 * @return Handle to cancel message. NULL if @c cont is NULL.
2362 struct MeshTunnel3Queue *
2363 GMT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2364 struct MeshTunnel3 *t, int force,
2365 GMT_sent cont, void *cont_cls)
2367 return send_prebuilt_message (message, t, force, cont, cont_cls, NULL);
2372 * Is the tunnel directed towards the local peer?
2376 * @return #GNUNET_YES if it is loopback.
2379 GMT_is_loopback (const struct MeshTunnel3 *t)
2381 return (myid == GMP_get_short_id (t->peer));
2386 * Is the tunnel this path already?
2391 * @return #GNUNET_YES a connection uses this path.
2394 GMT_is_path_used (const struct MeshTunnel3 *t, const struct MeshPeerPath *p)
2396 struct MeshTConnection *iter;
2398 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2399 if (GMC_get_path (iter->c) == p)
2407 * Get a cost of a path for a tunnel considering existing connections.
2410 * @param path Candidate path.
2412 * @return Cost of the path (path length + number of overlapping nodes)
2415 GMT_get_path_cost (const struct MeshTunnel3 *t,
2416 const struct MeshPeerPath *path)
2418 struct MeshTConnection *iter;
2419 const struct MeshPeerPath *aux;
2420 unsigned int overlap;
2428 GNUNET_assert (NULL != t);
2430 for (i = 0; i < path->length; i++)
2432 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2434 aux = GMC_get_path (iter->c);
2438 for (j = 0; j < aux->length; j++)
2440 if (path->peers[i] == aux->peers[j])
2448 return (path->length + overlap) * (path->score * -1);
2453 * Get the static string for the peer this tunnel is directed.
2457 * @return Static string the destination peer's ID.
2460 GMT_2s (const struct MeshTunnel3 *t)
2465 return GMP_2s (t->peer);