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_enc.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, 30)
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 MeshTunnelQueue *tq_head;
140 struct MeshTunnelQueue *tq_tail;
145 * Struct used to queue messages in a tunnel.
147 struct MeshTunnelQueue
152 struct MeshTunnelQueue *next;
153 struct MeshTunnelQueue *prev;
158 struct MeshChannel *ch;
163 /* struct GNUNET_MessageHeader *msg; */
167 /******************************************************************************/
168 /******************************* GLOBALS ***********************************/
169 /******************************************************************************/
172 * Global handle to the statistics service.
174 extern struct GNUNET_STATISTICS_Handle *stats;
177 * Local peer own ID (memory efficient handle).
179 extern GNUNET_PEER_Id myid;
182 * Local peer own ID (full value).
184 extern struct GNUNET_PeerIdentity my_full_id;
188 * Set of all tunnels, in order to trigger a new exchange on rekey.
189 * Indexed by peer's ID.
191 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
194 * Default TTL for payload packets.
196 static unsigned long long default_ttl;
201 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
204 * Own ephemeral private key.
206 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
209 * Cached message used to perform a key exchange.
211 static struct GNUNET_MESH_KX_Ephemeral kx_msg;
214 * Task to generate a new ephemeral key.
216 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
221 static struct GNUNET_TIME_Relative rekey_period;
223 /******************************************************************************/
224 /******************************** STATIC ***********************************/
225 /******************************************************************************/
228 * Get string description for tunnel state.
230 * @param s Tunnel state.
232 * @return String representation.
235 GMT_state2s (enum MeshTunnel3State s)
237 static char buf[128];
241 case MESH_TUNNEL3_NEW:
242 return "MESH_TUNNEL3_NEW";
243 case MESH_TUNNEL3_SEARCHING:
244 return "MESH_TUNNEL3_SEARCHING";
245 case MESH_TUNNEL3_WAITING:
246 return "MESH_TUNNEL3_WAITING";
247 case MESH_TUNNEL3_READY:
248 return "MESH_TUNNEL3_READY";
249 case MESH_TUNNEL3_RECONNECTING:
250 return "MESH_TUNNEL3_RECONNECTING";
253 sprintf (buf, "%u (UNKNOWN STATE)", s);
260 * Ephemeral key message purpose size.
262 * @return Size of the part of the ephemeral key message that must be signed.
265 ephemeral_purpose_size (void)
267 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
268 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
269 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
270 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
271 sizeof (struct GNUNET_PeerIdentity);
276 * Size of the encrypted part of a ping message.
278 * @return Size of the encrypted part of a ping message.
281 ping_encryption_size (void)
283 return sizeof (struct GNUNET_PeerIdentity) + sizeof (uint32_t);
288 * Check that a ephemeral key message s well formed and correctly signed.
290 * @param t Tunnel on which the message came.
291 * @param msg The ephemeral key message.
293 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
296 check_ephemeral (struct MeshTunnel3 *t,
297 const struct GNUNET_MESH_KX_Ephemeral *msg)
299 /* Check message size */
300 if (ntohs (msg->header.size) != sizeof (struct GNUNET_MESH_KX_Ephemeral))
301 return GNUNET_SYSERR;
303 /* Check signature size */
304 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
305 return GNUNET_SYSERR;
308 if (0 != memcmp (&msg->origin_identity,
309 GMP_get_id (t->peer),
310 sizeof (struct GNUNET_PeerIdentity)))
311 return GNUNET_SYSERR;
313 /* Check signature */
315 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_MESH_KX,
318 &msg->origin_identity.public_key))
319 return GNUNET_SYSERR;
326 * Encrypt data with the tunnel key.
328 * @param t Tunnel whose key to use.
329 * @param dst Destination for the encrypted data.
330 * @param src Source of the plaintext. Can overlap with @c dst.
331 * @param size Size of the plaintext.
332 * @param iv Initialization Vector to use.
335 t_encrypt (struct MeshTunnel3 *t,
336 void *dst, const void *src,
337 size_t size, uint32_t iv)
339 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
341 GNUNET_CRYPTO_symmetric_derive_iv (&siv, &t->e_key, &iv, sizeof (uint32_t), NULL);
342 return GNUNET_CRYPTO_symmetric_encrypt (src, size, &t->e_key, &siv, dst);
347 * Decrypt data with the tunnel key.
349 * @param t Tunnel whose key to use.
350 * @param dst Destination for the plaintext.
351 * @param src Source of the encrypted data. Can overlap with @c dst.
352 * @param size Size of the encrypted data.
353 * @param iv Initialization Vector to use.
356 t_decrypt (struct MeshTunnel3 *t,
357 void *dst, const void *src,
358 size_t size, uint32_t iv)
360 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
362 GNUNET_CRYPTO_symmetric_derive_iv (&siv, &t->e_key, &iv, sizeof (uint32_t), NULL);
363 return GNUNET_CRYPTO_symmetric_decrypt (src, size, &t->d_key, &siv, dst);
368 * Create key material by doing ECDH on the local and remote ephemeral keys.
370 * @param key_material Where to store the key material.
371 * @param ephemeral_key Peer's public ephemeral key.
374 derive_key_material (struct GNUNET_HashCode *key_material,
375 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
378 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
387 * Create a symmetic key from the identities of both ends and the key material
390 * @param key Destination for the generated key.
391 * @param sender ID of the peer that will encrypt with @c key.
392 * @param receiver ID of the peer that will decrypt with @c key.
393 * @param key_material Hash created with ECDH with the ephemeral keys.
396 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
397 const struct GNUNET_PeerIdentity *sender,
398 const struct GNUNET_PeerIdentity *receiver,
399 const struct GNUNET_HashCode *key_material)
401 const char salt[] = "MESH kx salt";
403 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
405 key_material, sizeof (struct GNUNET_HashCode),
406 sender, sizeof (struct GNUNET_PeerIdentity),
407 receiver, sizeof (struct GNUNET_PeerIdentity),
412 * Pick a connection on which send the next data message.
414 * @param t Tunnel on which to send the message.
415 * @param fwd Is this a fwd message?
417 * @return The connection on which to send the next message.
419 static struct MeshConnection *
420 tunnel_get_connection (struct MeshTunnel3 *t, int fwd)
422 struct MeshTConnection *iter;
423 struct MeshConnection *best;
425 unsigned int lowest_q;
427 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GMP_2s (t->peer));
430 for (iter = t->connection_head; NULL != iter; iter = iter->next)
432 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
433 GNUNET_h2s (GMC_get_id (iter->c)), GMC_get_state (iter->c));
434 if (MESH_CONNECTION_READY == GMC_get_state (iter->c))
436 qn = GMC_get_qn (iter->c, fwd);
437 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
450 * Send all cached messages that we can, tunnel is online.
452 * @param t Tunnel that holds the messages.
453 * @param fwd Is this fwd?
456 send_queued_data (struct MeshTunnel3 *t, int fwd)
458 struct MeshTunnelQueue *tq;
459 struct MeshTunnelQueue *next;
462 LOG (GNUNET_ERROR_TYPE_DEBUG,
463 "GMT_send_queued_data on tunnel %s\n",
466 if (NULL == t->channel_head ||
467 GNUNET_NO == GMCH_is_origin (t->channel_head->ch, fwd))
470 room = GMT_get_buffer (t, fwd);
471 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
472 for (tq = t->tq_head; NULL != tq && room > 0; tq = next)
474 LOG (GNUNET_ERROR_TYPE_DEBUG, " data on channel %s\n", GMCH_2s (tq->ch));
477 GNUNET_CONTAINER_DLL_remove (t->tq_head, t->tq_tail, tq);
478 GMCH_send_prebuilt_message ((struct GNUNET_MessageHeader *) &tq[1],
483 LOG (GNUNET_ERROR_TYPE_DEBUG,
484 "GMT_send_queued_data end\n",
492 * Cache a message to be sent once tunnel is online.
494 * @param t Tunnel to hold the message.
495 * @param ch Channel the message is about.
496 * @param msg Message itself (copy will be made).
497 * @param fwd Is this fwd?
500 queue_data (struct MeshTunnel3 *t,
501 struct MeshChannel *ch,
502 const struct GNUNET_MessageHeader *msg,
505 struct MeshTunnelQueue *tq;
506 uint16_t size = ntohs (msg->size);
508 if (MESH_TUNNEL3_READY == t->state)
511 GMT_send_prebuilt_message (msg, t, ch, fwd);
515 tq = GNUNET_malloc (sizeof (struct MeshTunnelQueue) + size);
518 memcpy (&tq[1], msg, size);
519 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tq);
525 * Send the ephemeral key on a tunnel.
527 * @param t Tunnel on which to send the key.
530 send_ephemeral (struct MeshTunnel3 *t)
532 kx_msg.sender_status = htonl (t->state);
534 /* When channel is NULL, fwd is irrelevant. */
535 GMT_send_prebuilt_message (&kx_msg.header, t, NULL, GNUNET_YES);
539 * Send a ping message on a tunnel.
541 * @param t Tunnel on which to send the ping.
544 send_ping (struct MeshTunnel3 *t)
546 struct GNUNET_MESH_KX_Ping msg;
548 msg.header.size = htons (sizeof (msg));
549 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_PING);
550 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
551 msg.target = *GMP_get_id (t->peer);
552 msg.nonce = t->kx_ctx->challenge;
553 t_encrypt (t, &msg.target, &msg.target, ping_encryption_size(), msg.iv);
555 /* When channel is NULL, fwd is irrelevant. */
556 GMT_send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES);
561 * Send a pong message on a tunnel.
563 * @param t Tunnel on which to send the pong.
564 * @param challenge Value sent in the ping that we have to send back.
567 send_pong (struct MeshTunnel3 *t, uint32_t challenge)
569 struct GNUNET_MESH_KX_Pong msg;
571 msg.header.size = htons (sizeof (msg));
572 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_PONG);
573 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
574 msg.nonce = challenge;
575 t_encrypt (t, &msg.nonce, &msg.nonce, sizeof (msg.nonce), msg.iv);
577 /* When channel is NULL, fwd is irrelevant. */
578 GMT_send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES);
583 * Initiate a rekey with the remote peer.
585 * @param cls Closure (tunnel).
586 * @param tc TaskContext.
589 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
591 struct MeshTunnel3 *t = cls;
593 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
595 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
598 t->kx_ctx = GNUNET_new (struct MeshTunnelKXCtx);
599 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
601 t->kx_ctx->d_key_old = t->d_key;
604 t->rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_WAIT, &rekey_tunnel, t);
609 * Out ephemeral key has changed, create new session key on all tunnels.
611 * @param cls Closure (size of the hashmap).
612 * @param key Current public key.
613 * @param value Value in the hash map (tunnel).
615 * @return #GNUNET_YES, so we should continue to iterate,
618 rekey_iterator (void *cls,
619 const struct GNUNET_PeerIdentity *key,
622 struct MeshTunnel3 *t = value;
623 struct GNUNET_TIME_Relative delay;
627 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
628 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
629 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
636 * Create a new ephemeral key and key message, schedule next rekeying.
638 * @param cls Closure (unused).
639 * @param tc TaskContext.
642 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
644 struct GNUNET_TIME_Absolute time;
647 rekey_task = GNUNET_SCHEDULER_NO_TASK;
649 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
652 GNUNET_free_non_null (my_ephemeral_key);
653 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
655 time = GNUNET_TIME_absolute_get ();
656 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
657 time = GNUNET_TIME_absolute_add (time, rekey_period);
658 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
659 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
660 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
662 GNUNET_assert (GNUNET_OK ==
663 GNUNET_CRYPTO_eddsa_sign (my_private_key,
667 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
668 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
670 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
675 * Demultiplex data per channel and call appropriate channel handler.
677 * @param t Tunnel on which the data came.
678 * @param msg Data message.
679 * @param fwd Is this FWD data? (root -> dest)
682 handle_data (struct MeshTunnel3 *t,
683 const struct GNUNET_MESH_Data *msg,
686 struct MeshChannel *ch;
691 size = ntohs (msg->header.size);
693 sizeof (struct GNUNET_MESH_Data) +
694 sizeof (struct GNUNET_MessageHeader))
699 type = ntohs (msg->header.type);
700 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a %s message\n",
701 GNUNET_MESH_DEBUG_M2S (type));
702 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
703 GNUNET_MESH_DEBUG_M2S (ntohs (msg[1].header.type)));
706 ch = GMT_get_channel (t, ntohl (msg->chid));
709 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
711 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
716 GMT_change_state (t, MESH_TUNNEL3_READY);
717 GMCH_handle_data (ch, msg, fwd);
721 handle_data_ack (struct MeshTunnel3 *t,
722 const struct GNUNET_MESH_DataACK *msg,
725 struct MeshChannel *ch;
729 size = ntohs (msg->header.size);
730 if (size != sizeof (struct GNUNET_MESH_DataACK))
737 ch = GMT_get_channel (t, ntohl (msg->chid));
740 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
742 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
747 GMCH_handle_data_ack (ch, msg, fwd);
751 handle_ch_create (struct MeshTunnel3 *t,
752 const struct GNUNET_MESH_ChannelCreate *msg,
755 struct MeshChannel *ch;
759 size = ntohs (msg->header.size);
760 if (size != sizeof (struct GNUNET_MESH_ChannelCreate))
767 ch = GMT_get_channel (t, ntohl (msg->chid));
770 /* Probably a retransmission, safe to ignore */
771 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
775 ch = GMCH_handle_create (t, msg, fwd);
777 GMT_add_channel (t, ch);
781 handle_ch_ack (struct MeshTunnel3 *t,
782 const struct GNUNET_MESH_ChannelManage *msg,
785 struct MeshChannel *ch;
789 size = ntohs (msg->header.size);
790 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
797 ch = GMT_get_channel (t, ntohl (msg->chid));
800 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
802 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
807 GMCH_handle_ack (ch, msg, fwd);
811 handle_ch_destroy (struct MeshTunnel3 *t,
812 const struct GNUNET_MESH_ChannelManage *msg,
815 struct MeshChannel *ch;
819 size = ntohs (msg->header.size);
820 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
827 ch = GMT_get_channel (t, ntohl (msg->chid));
830 /* Probably a retransmission, safe to ignore */
834 GMCH_handle_destroy (ch, msg, fwd);
839 * The peer's ephemeral key has changed: update the symmetrical keys.
841 * @param t Tunnel this message came on.
842 * @param msg Key eXchange message.
845 handle_ephemeral (struct MeshTunnel3 *t,
846 const struct GNUNET_MESH_KX_Ephemeral *msg)
848 struct GNUNET_HashCode km;
849 LOG (GNUNET_ERROR_TYPE_DEBUG, " ephemeral key message\n");
851 if (GNUNET_OK != check_ephemeral (t, msg))
856 derive_key_material (&km, &msg->ephemeral_key);
857 derive_symmertic (&t->e_key, &my_full_id, GMP_get_id (t->peer), &km);
858 derive_symmertic (&t->d_key, GMP_get_id (t->peer), &my_full_id, &km);
863 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
864 * Answer with by retransmitting the challenge with the "opposite" key.
866 * @param t Tunnel this message came on.
867 * @param msg Key eXchange Ping message.
870 handle_ping (struct MeshTunnel3 *t,
871 const struct GNUNET_MESH_KX_Ping *msg)
873 struct GNUNET_MESH_KX_Ping res;
875 LOG (GNUNET_ERROR_TYPE_DEBUG, " ping message\n");
876 t_decrypt (t, &res.target, &msg->target, ping_encryption_size(), msg->iv);
877 if (0 != memcmp (&my_full_id, &msg->target, sizeof (my_full_id)))
880 LOG (GNUNET_ERROR_TYPE_DEBUG, " at %s\n", GNUNET_i2s (&my_full_id));
881 LOG (GNUNET_ERROR_TYPE_DEBUG, " for %s\n", GNUNET_i2s (&msg->target));
885 send_pong (t, res.iv);
890 * Peer has answer to our challenge.
891 * If answer is successful, consider the key exchange finished and clean
892 * up all related state.
894 * @param t Tunnel this message came on.
895 * @param msg Key eXchange Pong message.
898 handle_pong (struct MeshTunnel3 *t,
899 const struct GNUNET_MESH_KX_Pong *msg)
901 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
903 GNUNET_SCHEDULER_cancel (t->rekey_task);
904 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
905 GNUNET_free (t->kx_ctx);
916 * Demultiplex by message type and call appropriate handler for a message
917 * towards a channel of a local tunnel.
919 * @param t Tunnel this message came on.
920 * @param msgh Message header.
921 * @param fwd Is this message fwd?
924 handle_decrypted (struct MeshTunnel3 *t,
925 const struct GNUNET_MessageHeader *msgh,
930 type = ntohs (msgh->type);
931 LOG (GNUNET_ERROR_TYPE_DEBUG,
932 "Got a %s message!\n",
933 GNUNET_MESH_DEBUG_M2S (type));
937 case GNUNET_MESSAGE_TYPE_MESH_DATA:
938 /* Don't send hop ACK, wait for client to ACK */
939 handle_data (t, (struct GNUNET_MESH_Data *) msgh, fwd);
942 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
943 handle_data_ack (t, (struct GNUNET_MESH_DataACK *) msgh, fwd);
946 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
948 (struct GNUNET_MESH_ChannelCreate *) msgh,
952 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
954 (struct GNUNET_MESH_ChannelManage *) msgh,
958 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
959 handle_ch_destroy (t,
960 (struct GNUNET_MESH_ChannelManage *) msgh,
966 LOG (GNUNET_ERROR_TYPE_DEBUG,
967 "end-to-end message not known (%u)\n",
972 /******************************************************************************/
973 /******************************** API ***********************************/
974 /******************************************************************************/
977 * Decrypt and demultiplex by message type. Call appropriate handler
980 * @param t Tunnel this message came on.
981 * @param msg Encrypted message.
982 * @param fwd Is this message fwd?
985 GMT_handle_encrypted (struct MeshTunnel3 *t,
986 const struct GNUNET_MESH_Encrypted *msg,
989 size_t size = ntohs (msg->header.size);
990 size_t payload_size = size - sizeof (struct GNUNET_MESH_Encrypted);
991 size_t decrypted_size;
992 char cbuf [payload_size];
993 struct GNUNET_MessageHeader *msgh;
996 decrypted_size = t_decrypt (t, cbuf, &msg[1], payload_size, msg->iv);
998 while (off < decrypted_size)
1000 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
1001 handle_decrypted (t, msgh, fwd);
1002 off += ntohs (msgh->size);
1008 * Demultiplex an encapsulated KX message by message type.
1010 * @param t Tunnel on which the message came.
1011 * @param message Payload of KX message.
1014 GMT_handle_kx (struct MeshTunnel3 *t,
1015 const struct GNUNET_MessageHeader *message)
1019 type = ntohs (message->type);
1020 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
1023 case GNUNET_MESSAGE_TYPE_MESH_KX:
1024 handle_ephemeral (t, (struct GNUNET_MESH_KX_Ephemeral *) message);
1027 case GNUNET_MESSAGE_TYPE_MESH_KX_PING:
1028 handle_ping (t, (struct GNUNET_MESH_KX_Ping *) message);
1031 case GNUNET_MESSAGE_TYPE_MESH_KX_PONG:
1032 handle_pong (t, (struct GNUNET_MESH_KX_Pong *) message);
1036 GNUNET_break_op (0);
1037 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
1043 * Initialize the tunnel subsystem.
1045 * @param c Configuration handle.
1046 * @param key ECC private key, to derive all other keys and do crypto.
1049 GMT_init (const struct GNUNET_CONFIGURATION_Handle *c,
1050 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
1052 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1054 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "DEFAULT_TTL",
1057 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1058 "MESH", "DEFAULT_TTL", "USING DEFAULT");
1062 GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REKEY_PERIOD",
1065 rekey_period = GNUNET_TIME_UNIT_DAYS;
1068 my_private_key = key;
1069 kx_msg.header.size = htons (sizeof (kx_msg));
1070 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX);
1071 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_MESH_KX);
1072 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
1073 kx_msg.origin_identity = my_full_id;
1074 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
1076 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
1081 * Shut down the tunnel subsystem.
1086 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
1088 GNUNET_SCHEDULER_cancel (rekey_task);
1089 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1091 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
1098 * @param destination Peer this tunnel is towards.
1100 struct MeshTunnel3 *
1101 GMT_new (struct MeshPeer *destination)
1103 struct MeshTunnel3 *t;
1105 t = GNUNET_new (struct MeshTunnel3);
1107 t->peer = destination;
1110 GNUNET_CONTAINER_multipeermap_put (tunnels, GMP_get_id (destination), t,
1111 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
1122 * Change the tunnel state.
1124 * @param t Tunnel whose state to change.
1125 * @param state New state.
1128 GMT_change_state (struct MeshTunnel3* t, enum MeshTunnel3State state)
1132 LOG (GNUNET_ERROR_TYPE_DEBUG,
1133 "Tunnel %s state was %s\n",
1135 GMT_state2s (t->state));
1136 LOG (GNUNET_ERROR_TYPE_DEBUG,
1137 "Tunnel %s state is now %s\n",
1139 GMT_state2s (state));
1140 if (MESH_TUNNEL3_WAITING == t->state)
1142 send_queued_data (t, GNUNET_YES);
1143 send_queued_data (t, GNUNET_NO);
1146 if (MESH_TUNNEL3_READY == state && 3 <= GMT_count_connections (t))
1148 GMP_stop_search (t->peer);
1154 * Add a connection to a tunnel.
1157 * @param c Connection.
1160 GMT_add_connection (struct MeshTunnel3 *t, struct MeshConnection *c)
1162 struct MeshTConnection *aux;
1164 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1168 aux = GNUNET_new (struct MeshTConnection);
1170 GNUNET_CONTAINER_DLL_insert_tail (t->connection_head, t->connection_tail, aux);
1175 * Remove a connection from a tunnel.
1178 * @param c Connection.
1181 GMT_remove_connection (struct MeshTunnel3 *t, struct MeshConnection *c)
1183 struct MeshTConnection *aux;
1185 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1188 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
1196 * Add a channel to a tunnel.
1199 * @param ch Channel.
1202 GMT_add_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1204 struct MeshTChannel *aux;
1206 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
1208 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1210 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
1215 aux = GNUNET_new (struct MeshTChannel);
1217 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
1218 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
1223 * Remove a channel from a tunnel.
1226 * @param ch Channel.
1229 GMT_remove_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1231 struct MeshTChannel *aux;
1233 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
1234 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1238 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GMCH_2s (ch));
1239 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
1248 * Search for a channel by global ID.
1250 * @param t Tunnel containing the channel.
1251 * @param chid Public channel number.
1253 * @return channel handler, NULL if doesn't exist
1255 struct MeshChannel *
1256 GMT_get_channel (struct MeshTunnel3 *t, MESH_ChannelNumber chid)
1258 struct MeshTChannel *iter;
1263 for (iter = t->channel_head; NULL != iter; iter = iter->next)
1265 if (GMCH_get_id (iter->ch) == chid)
1269 return NULL == iter ? NULL : iter->ch;
1274 * Tunnel is empty: destroy it.
1276 * Notifies all connections about the destruction.
1278 * @param t Tunnel to destroy.
1281 GMT_destroy_empty (struct MeshTunnel3 *t)
1283 struct MeshTConnection *iter;
1285 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1287 GMC_send_destroy (iter->c);
1290 t->destroy = GNUNET_YES;
1295 * Destroy tunnel if empty (no more channels).
1297 * @param t Tunnel to destroy if empty.
1300 GMT_destroy_if_empty (struct MeshTunnel3 *t)
1302 if (1 < GMT_count_channels (t))
1305 GMT_destroy_empty (t);
1310 * Destroy the tunnel.
1312 * This function does not generate any warning traffic to clients or peers.
1315 * Cancel messages belonging to this tunnel queued to neighbors.
1316 * Free any allocated resources linked to the tunnel.
1318 * @param t The tunnel to destroy.
1321 GMT_destroy (struct MeshTunnel3 *t)
1323 struct MeshTConnection *iter;
1324 struct MeshTConnection *next;
1329 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GMP_2s (t->peer));
1331 // if (GNUNET_YES != GNUNET_CONTAINER_multihashmap_remove (tunnels, &t->id, t))
1332 // GNUNET_break (0);
1334 for (iter = t->connection_head; NULL != iter; iter = next)
1337 GMC_destroy (iter->c);
1340 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
1341 GMP_set_tunnel (t->peer, NULL);
1343 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1344 GNUNET_SCHEDULER_cancel (t->rekey_task);
1351 * @brief Use the given path for the tunnel.
1352 * Update the next and prev hops (and RCs).
1353 * (Re)start the path refresh in case the tunnel is locally owned.
1355 * @param t Tunnel to update.
1356 * @param p Path to use.
1358 * @return Connection created.
1360 struct MeshConnection *
1361 GMT_use_path (struct MeshTunnel3 *t, struct MeshPeerPath *p)
1363 struct MeshConnection *c;
1364 struct GNUNET_HashCode cid;
1365 unsigned int own_pos;
1367 if (NULL == t || NULL == p)
1373 for (own_pos = 0; own_pos < p->length; own_pos++)
1375 if (p->peers[own_pos] == myid)
1378 if (own_pos > p->length - 1)
1384 GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE, &cid);
1385 c = GMC_new (&cid, t, p, own_pos);
1386 GMT_add_connection (t, c);
1392 * Count established (ready) connections of a tunnel.
1394 * @param t Tunnel on which to count.
1396 * @return Number of connections.
1399 GMT_count_connections (struct MeshTunnel3 *t)
1401 struct MeshTConnection *iter;
1404 for (count = 0, iter = t->connection_head;
1406 iter = iter->next, count++);
1412 * Count channels of a tunnel.
1414 * @param t Tunnel on which to count.
1416 * @return Number of channels.
1419 GMT_count_channels (struct MeshTunnel3 *t)
1421 struct MeshTChannel *iter;
1424 for (count = 0, iter = t->channel_head;
1426 iter = iter->next, count++) /* skip */;
1433 * Get the state of a tunnel.
1437 * @return Tunnel's state.
1439 enum MeshTunnel3State
1440 GMT_get_state (struct MeshTunnel3 *t)
1443 return (enum MeshTunnel3State) -1;
1448 * Get the total buffer space for a tunnel.
1450 * If terminal, use the biggest channel buffer (or 64) if no channel exists.
1451 * If not terminal, use the sum of all connection buffers.
1454 * @param fwd Is this for FWD traffic?
1456 * @return Buffer space offered by all entities (c/ch) in the tunnel.
1459 GMT_get_buffer (struct MeshTunnel3 *t, int fwd)
1461 struct MeshTConnection *iter;
1462 unsigned int buffer;
1464 iter = t->connection_head;
1467 /* If terminal, return biggest channel buffer */
1468 if (NULL == iter || GMC_is_terminal (iter->c, fwd))
1470 struct MeshTChannel *iter_ch;
1471 unsigned int ch_buf;
1473 if (NULL == t->channel_head)
1475 /* Probably getting buffer for a channel create/handshake. */
1479 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = iter_ch->next)
1481 ch_buf = GMCH_get_buffer (iter_ch->ch, fwd);
1482 if (ch_buf > buffer)
1488 /* If not terminal, return sum of connection buffers */
1489 while (NULL != iter)
1491 if (GMC_get_state (iter->c) != MESH_CONNECTION_READY)
1497 buffer += GMC_get_buffer (iter->c, fwd);
1506 * Get the tunnel's destination.
1510 * @return ID of the destination peer.
1512 const struct GNUNET_PeerIdentity *
1513 GMT_get_destination (struct MeshTunnel3 *t)
1515 return GMP_get_id (t->peer);
1520 * Get the tunnel's next free global channel ID.
1524 * @return GID of a channel free to use.
1527 GMT_get_next_chid (struct MeshTunnel3 *t)
1529 MESH_ChannelNumber chid;
1531 while (NULL != GMT_get_channel (t, t->next_chid))
1533 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
1534 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
1536 chid = t->next_chid;
1537 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
1544 * Send ACK on one or more channels due to buffer in connections.
1546 * @param t Channel which has some free buffer space.
1547 * @param fwd Is this for FWD traffic? (ACK goes to root)
1550 GMT_unchoke_channels (struct MeshTunnel3 *t, int fwd)
1552 struct MeshTChannel *iter;
1553 unsigned int buffer;
1554 unsigned int channels = GMT_count_channels (t);
1555 unsigned int choked_n;
1556 struct MeshChannel *choked[channels];
1558 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT_unchoke_channels on %s\n", GMT_2s (t));
1559 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
1560 if (NULL != t->channel_head)
1561 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
1569 /* Get buffer space */
1570 buffer = GMT_get_buffer (t, fwd);
1576 /* Count and remember choked channels */
1578 for (iter = t->channel_head; NULL != iter; iter = iter->next)
1580 if (GNUNET_NO == GMCH_get_allowed (iter->ch, fwd))
1582 choked[choked_n++] = iter->ch;
1586 /* Unchoke random channels */
1587 while (0 < buffer && 0 < choked_n)
1589 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1591 GMCH_allow_client (choked[r], fwd);
1594 choked[r] = choked[choked_n];
1600 * Send ACK on one or more connections due to buffer space to the client.
1602 * Iterates all connections of the tunnel and sends ACKs appropriately.
1605 * @param fwd Is this in for FWD traffic? (ACK goes dest->root)
1608 GMT_send_acks (struct MeshTunnel3 *t, int fwd)
1610 struct MeshTConnection *iter;
1613 uint32_t allow_per_connection;
1615 unsigned int buffer;
1617 LOG (GNUNET_ERROR_TYPE_DEBUG,
1618 "Tunnel send %s ACKs on %s\n",
1619 fwd ? "FWD" : "BCK", GMT_2s (t));
1626 if (NULL == t->channel_head ||
1627 GNUNET_NO == GMCH_is_origin (t->channel_head->ch, !fwd))
1633 buffer = GMT_get_buffer (t, fwd);
1635 /* Count connections, how many messages are already allowed */
1636 cs = GMT_count_connections (t);
1637 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
1639 allowed += GMC_get_allowed (iter->c, fwd);
1642 /* Make sure there is no overflow */
1643 if (allowed > buffer)
1649 /* Authorize connections to send more data */
1650 to_allow = buffer; /* - allowed; */
1652 for (iter = t->connection_head; NULL != iter && to_allow > 0; iter = iter->next)
1654 allow_per_connection = to_allow/cs;
1655 to_allow -= allow_per_connection;
1657 if (GMC_get_allowed (iter->c, fwd) > 64 / 3)
1661 GMC_allow (iter->c, buffer, fwd);
1664 GNUNET_break (to_allow == 0);
1669 * Sends an already built message on a tunnel, encrypting it and
1670 * choosing the best connection.
1672 * @param message Message to send. Function modifies it.
1673 * @param t Tunnel on which this message is transmitted.
1674 * @param ch Channel on which this message is transmitted.
1675 * @param fwd Is this a fwd message?
1678 GMT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1679 struct MeshTunnel3 *t,
1680 struct MeshChannel *ch,
1683 struct MeshConnection *c;
1684 struct GNUNET_MESH_Encrypted *msg;
1685 size_t size = ntohs (message->size);
1686 size_t encrypted_size;
1687 char *cbuf[sizeof (struct GNUNET_MESH_Encrypted) + size + 64];
1691 if (MESH_TUNNEL3_READY != t->state)
1693 queue_data (t, ch, message, fwd);
1696 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GMT_2s (t));
1698 iv = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_NONCE, UINT64_MAX);
1699 msg = (struct GNUNET_MESH_Encrypted *) cbuf;
1700 msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED);
1701 msg->iv = GNUNET_htonll (iv);
1702 encrypted_size = t_encrypt (t, &msg[1], message, size, iv);
1703 msg->header.size = htons (sizeof (struct GNUNET_MESH_Encrypted) + encrypted_size);
1704 c = tunnel_get_connection (t, fwd);
1707 GNUNET_break (GNUNET_YES == t->destroy);
1710 type = ntohs (message->type);
1713 case GNUNET_MESSAGE_TYPE_MESH_DATA:
1714 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
1715 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
1716 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
1717 msg->cid = *GMC_get_id (c);
1718 msg->ttl = htonl (default_ttl);
1721 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1722 GNUNET_MESH_DEBUG_M2S (type));
1726 GMC_send_prebuilt_message (&msg->header, c, fwd);
1730 * Is the tunnel directed towards the local peer?
1734 * @return GNUNET_YES if it is loopback.
1737 GMT_is_loopback (const struct MeshTunnel3 *t)
1739 return (myid == GMP_get_short_id(t->peer));
1744 * Is the tunnel using this path already?
1749 * @return GNUNET_YES a connection uses this path.
1752 GMT_is_path_used (const struct MeshTunnel3 *t, const struct MeshPeerPath *p)
1754 struct MeshTConnection *iter;
1756 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1757 if (GMC_get_path (iter->c) == p)
1765 * Get a cost of a path for a tunnel considering existing connections.
1768 * @param path Candidate path.
1770 * @return Cost of the path (path length + number of overlapping nodes)
1773 GMT_get_path_cost (const struct MeshTunnel3 *t,
1774 const struct MeshPeerPath *path)
1776 struct MeshTConnection *iter;
1777 unsigned int overlap;
1785 GNUNET_assert (NULL != t);
1787 for (i = 0; i < path->length; i++)
1789 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1791 for (j = 0; j < GMC_get_path (iter->c)->length; j++)
1793 if (path->peers[i] == GMC_get_path (iter->c)->peers[j])
1801 return (path->length + overlap) * (path->score * -1);
1806 * Get the static string for the peer this tunnel is directed.
1810 * @return Static string the destination peer's ID.
1813 GMT_2s (const struct MeshTunnel3 *t)
1815 return GMP_2s (t->peer);