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 (NULL != tc && 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;
603 if (MESH_TUNNEL3_READY == t->state)
606 t->state = MESH_TUNNEL3_REKEY;
608 else if (MESH_TUNNEL3_WAITING == t->state)
610 t->state = MESH_TUNNEL3_KEY_SENT;
614 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->state);
617 t->rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_WAIT, &rekey_tunnel, t);
622 * Out ephemeral key has changed, create new session key on all tunnels.
624 * @param cls Closure (size of the hashmap).
625 * @param key Current public key.
626 * @param value Value in the hash map (tunnel).
628 * @return #GNUNET_YES, so we should continue to iterate,
631 rekey_iterator (void *cls,
632 const struct GNUNET_PeerIdentity *key,
635 struct MeshTunnel3 *t = value;
636 struct GNUNET_TIME_Relative delay;
640 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
643 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
644 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
645 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
652 * Create a new ephemeral key and key message, schedule next rekeying.
654 * @param cls Closure (unused).
655 * @param tc TaskContext.
658 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
660 struct GNUNET_TIME_Absolute time;
663 rekey_task = GNUNET_SCHEDULER_NO_TASK;
665 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
668 GNUNET_free_non_null (my_ephemeral_key);
669 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
671 time = GNUNET_TIME_absolute_get ();
672 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
673 time = GNUNET_TIME_absolute_add (time, rekey_period);
674 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
675 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
676 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
678 GNUNET_assert (GNUNET_OK ==
679 GNUNET_CRYPTO_eddsa_sign (my_private_key,
683 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
684 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
686 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
691 * Demultiplex data per channel and call appropriate channel handler.
693 * @param t Tunnel on which the data came.
694 * @param msg Data message.
695 * @param fwd Is this FWD data? (root -> dest)
698 handle_data (struct MeshTunnel3 *t,
699 const struct GNUNET_MESH_Data *msg,
702 struct MeshChannel *ch;
707 size = ntohs (msg->header.size);
709 sizeof (struct GNUNET_MESH_Data) +
710 sizeof (struct GNUNET_MessageHeader))
715 type = ntohs (msg->header.type);
716 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a %s message\n",
717 GNUNET_MESH_DEBUG_M2S (type));
718 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
719 GNUNET_MESH_DEBUG_M2S (ntohs (msg[1].header.type)));
722 ch = GMT_get_channel (t, ntohl (msg->chid));
725 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
727 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
732 GMT_change_state (t, MESH_TUNNEL3_READY);
733 GMCH_handle_data (ch, msg, fwd);
737 handle_data_ack (struct MeshTunnel3 *t,
738 const struct GNUNET_MESH_DataACK *msg,
741 struct MeshChannel *ch;
745 size = ntohs (msg->header.size);
746 if (size != sizeof (struct GNUNET_MESH_DataACK))
753 ch = GMT_get_channel (t, ntohl (msg->chid));
756 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
758 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
763 GMCH_handle_data_ack (ch, msg, fwd);
767 handle_ch_create (struct MeshTunnel3 *t,
768 const struct GNUNET_MESH_ChannelCreate *msg,
771 struct MeshChannel *ch;
775 size = ntohs (msg->header.size);
776 if (size != sizeof (struct GNUNET_MESH_ChannelCreate))
783 ch = GMT_get_channel (t, ntohl (msg->chid));
786 /* Probably a retransmission, safe to ignore */
787 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
791 ch = GMCH_handle_create (t, msg, fwd);
793 GMT_add_channel (t, ch);
797 handle_ch_ack (struct MeshTunnel3 *t,
798 const struct GNUNET_MESH_ChannelManage *msg,
801 struct MeshChannel *ch;
805 size = ntohs (msg->header.size);
806 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
813 ch = GMT_get_channel (t, ntohl (msg->chid));
816 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
818 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
823 GMCH_handle_ack (ch, msg, fwd);
827 handle_ch_destroy (struct MeshTunnel3 *t,
828 const struct GNUNET_MESH_ChannelManage *msg,
831 struct MeshChannel *ch;
835 size = ntohs (msg->header.size);
836 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
843 ch = GMT_get_channel (t, ntohl (msg->chid));
846 /* Probably a retransmission, safe to ignore */
850 GMCH_handle_destroy (ch, msg, fwd);
855 * The peer's ephemeral key has changed: update the symmetrical keys.
857 * @param t Tunnel this message came on.
858 * @param msg Key eXchange message.
861 handle_ephemeral (struct MeshTunnel3 *t,
862 const struct GNUNET_MESH_KX_Ephemeral *msg)
864 struct GNUNET_HashCode km;
865 LOG (GNUNET_ERROR_TYPE_DEBUG, " ephemeral key message\n");
867 if (GNUNET_OK != check_ephemeral (t, msg))
872 derive_key_material (&km, &msg->ephemeral_key);
873 derive_symmertic (&t->e_key, &my_full_id, GMP_get_id (t->peer), &km);
874 derive_symmertic (&t->d_key, GMP_get_id (t->peer), &my_full_id, &km);
875 if (MESH_TUNNEL3_KEY_SENT == t->state)
878 t->state = MESH_TUNNEL3_PING_SENT;
884 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
885 * Answer with by retransmitting the challenge with the "opposite" key.
887 * @param t Tunnel this message came on.
888 * @param msg Key eXchange Ping message.
891 handle_ping (struct MeshTunnel3 *t,
892 const struct GNUNET_MESH_KX_Ping *msg)
894 struct GNUNET_MESH_KX_Ping res;
896 LOG (GNUNET_ERROR_TYPE_DEBUG, " ping message\n");
897 t_decrypt (t, &res.target, &msg->target, ping_encryption_size(), msg->iv);
898 if (0 != memcmp (&my_full_id, &msg->target, sizeof (my_full_id)))
901 LOG (GNUNET_ERROR_TYPE_DEBUG, " at %s\n", GNUNET_i2s (&my_full_id));
902 LOG (GNUNET_ERROR_TYPE_DEBUG, " for %s\n", GNUNET_i2s (&msg->target));
906 send_pong (t, res.iv);
911 * Peer has answer to our challenge.
912 * If answer is successful, consider the key exchange finished and clean
913 * up all related state.
915 * @param t Tunnel this message came on.
916 * @param msg Key eXchange Pong message.
919 handle_pong (struct MeshTunnel3 *t,
920 const struct GNUNET_MESH_KX_Pong *msg)
924 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG received\n");
925 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
930 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
932 if (challenge != t->kx_ctx->challenge)
934 LOG (GNUNET_ERROR_TYPE_DEBUG,
935 "Wrong PONG challenge: %u. Expected: %u.\n",
936 challenge, t->kx_ctx->challenge);
940 GNUNET_SCHEDULER_cancel (t->rekey_task);
941 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
942 GNUNET_free (t->kx_ctx);
944 t->state = MESH_TUNNEL3_READY;
945 send_queued_data (t, GNUNET_YES);
946 send_queued_data (t, GNUNET_NO);
951 * Demultiplex by message type and call appropriate handler for a message
952 * towards a channel of a local tunnel.
954 * @param t Tunnel this message came on.
955 * @param msgh Message header.
956 * @param fwd Is this message fwd?
959 handle_decrypted (struct MeshTunnel3 *t,
960 const struct GNUNET_MessageHeader *msgh,
965 type = ntohs (msgh->type);
966 LOG (GNUNET_ERROR_TYPE_DEBUG,
967 "Got a %s message!\n",
968 GNUNET_MESH_DEBUG_M2S (type));
972 case GNUNET_MESSAGE_TYPE_MESH_DATA:
973 /* Don't send hop ACK, wait for client to ACK */
974 handle_data (t, (struct GNUNET_MESH_Data *) msgh, fwd);
977 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
978 handle_data_ack (t, (struct GNUNET_MESH_DataACK *) msgh, fwd);
981 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
983 (struct GNUNET_MESH_ChannelCreate *) msgh,
987 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
989 (struct GNUNET_MESH_ChannelManage *) msgh,
993 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
994 handle_ch_destroy (t,
995 (struct GNUNET_MESH_ChannelManage *) msgh,
1000 GNUNET_break_op (0);
1001 LOG (GNUNET_ERROR_TYPE_DEBUG,
1002 "end-to-end message not known (%u)\n",
1003 ntohs (msgh->type));
1007 /******************************************************************************/
1008 /******************************** API ***********************************/
1009 /******************************************************************************/
1012 * Decrypt and demultiplex by message type. Call appropriate handler
1013 * for every message.
1015 * @param t Tunnel this message came on.
1016 * @param msg Encrypted message.
1017 * @param fwd Is this message fwd?
1020 GMT_handle_encrypted (struct MeshTunnel3 *t,
1021 const struct GNUNET_MESH_Encrypted *msg,
1024 size_t size = ntohs (msg->header.size);
1025 size_t payload_size = size - sizeof (struct GNUNET_MESH_Encrypted);
1026 size_t decrypted_size;
1027 char cbuf [payload_size];
1028 struct GNUNET_MessageHeader *msgh;
1031 decrypted_size = t_decrypt (t, cbuf, &msg[1], payload_size, msg->iv);
1033 while (off < decrypted_size)
1035 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
1036 handle_decrypted (t, msgh, fwd);
1037 off += ntohs (msgh->size);
1043 * Demultiplex an encapsulated KX message by message type.
1045 * @param t Tunnel on which the message came.
1046 * @param message Payload of KX message.
1049 GMT_handle_kx (struct MeshTunnel3 *t,
1050 const struct GNUNET_MessageHeader *message)
1054 type = ntohs (message->type);
1055 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
1058 case GNUNET_MESSAGE_TYPE_MESH_KX:
1059 handle_ephemeral (t, (struct GNUNET_MESH_KX_Ephemeral *) message);
1062 case GNUNET_MESSAGE_TYPE_MESH_KX_PING:
1063 handle_ping (t, (struct GNUNET_MESH_KX_Ping *) message);
1066 case GNUNET_MESSAGE_TYPE_MESH_KX_PONG:
1067 handle_pong (t, (struct GNUNET_MESH_KX_Pong *) message);
1071 GNUNET_break_op (0);
1072 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
1078 * Initialize the tunnel subsystem.
1080 * @param c Configuration handle.
1081 * @param key ECC private key, to derive all other keys and do crypto.
1084 GMT_init (const struct GNUNET_CONFIGURATION_Handle *c,
1085 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
1087 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1089 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "DEFAULT_TTL",
1092 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1093 "MESH", "DEFAULT_TTL", "USING DEFAULT");
1097 GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REKEY_PERIOD",
1100 rekey_period = GNUNET_TIME_UNIT_DAYS;
1103 my_private_key = key;
1104 kx_msg.header.size = htons (sizeof (kx_msg));
1105 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX);
1106 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_MESH_KX);
1107 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
1108 kx_msg.origin_identity = my_full_id;
1109 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
1111 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
1116 * Shut down the tunnel subsystem.
1121 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
1123 GNUNET_SCHEDULER_cancel (rekey_task);
1124 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1126 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
1133 * @param destination Peer this tunnel is towards.
1135 struct MeshTunnel3 *
1136 GMT_new (struct MeshPeer *destination)
1138 struct MeshTunnel3 *t;
1140 t = GNUNET_new (struct MeshTunnel3);
1142 t->peer = destination;
1145 GNUNET_CONTAINER_multipeermap_put (tunnels, GMP_get_id (destination), t,
1146 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
1157 * Change the tunnel state.
1159 * @param t Tunnel whose state to change.
1160 * @param state New state.
1163 GMT_change_state (struct MeshTunnel3* t, enum MeshTunnel3State state)
1167 LOG (GNUNET_ERROR_TYPE_DEBUG,
1168 "Tunnel %s state was %s\n",
1170 GMT_state2s (t->state));
1171 LOG (GNUNET_ERROR_TYPE_DEBUG,
1172 "Tunnel %s state is now %s\n",
1174 GMT_state2s (state));
1175 if (myid != GMP_get_short_id(t->peer) &&
1176 MESH_TUNNEL3_WAITING == t->state && MESH_TUNNEL3_READY == state)
1178 rekey_tunnel (t, NULL);
1184 if (MESH_TUNNEL3_READY == state && 3 <= GMT_count_connections (t))
1186 GMP_stop_search (t->peer);
1192 * Add a connection to a tunnel.
1195 * @param c Connection.
1198 GMT_add_connection (struct MeshTunnel3 *t, struct MeshConnection *c)
1200 struct MeshTConnection *aux;
1202 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1206 aux = GNUNET_new (struct MeshTConnection);
1208 GNUNET_CONTAINER_DLL_insert_tail (t->connection_head, t->connection_tail, aux);
1213 * Remove a connection from a tunnel.
1216 * @param c Connection.
1219 GMT_remove_connection (struct MeshTunnel3 *t, struct MeshConnection *c)
1221 struct MeshTConnection *aux;
1223 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1226 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
1234 * Add a channel to a tunnel.
1237 * @param ch Channel.
1240 GMT_add_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1242 struct MeshTChannel *aux;
1244 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
1246 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1248 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
1253 aux = GNUNET_new (struct MeshTChannel);
1255 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
1256 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
1261 * Remove a channel from a tunnel.
1264 * @param ch Channel.
1267 GMT_remove_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1269 struct MeshTChannel *aux;
1271 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
1272 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1276 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GMCH_2s (ch));
1277 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
1286 * Search for a channel by global ID.
1288 * @param t Tunnel containing the channel.
1289 * @param chid Public channel number.
1291 * @return channel handler, NULL if doesn't exist
1293 struct MeshChannel *
1294 GMT_get_channel (struct MeshTunnel3 *t, MESH_ChannelNumber chid)
1296 struct MeshTChannel *iter;
1301 for (iter = t->channel_head; NULL != iter; iter = iter->next)
1303 if (GMCH_get_id (iter->ch) == chid)
1307 return NULL == iter ? NULL : iter->ch;
1312 * Tunnel is empty: destroy it.
1314 * Notifies all connections about the destruction.
1316 * @param t Tunnel to destroy.
1319 GMT_destroy_empty (struct MeshTunnel3 *t)
1321 struct MeshTConnection *iter;
1323 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1325 GMC_send_destroy (iter->c);
1328 t->destroy = GNUNET_YES;
1333 * Destroy tunnel if empty (no more channels).
1335 * @param t Tunnel to destroy if empty.
1338 GMT_destroy_if_empty (struct MeshTunnel3 *t)
1340 if (1 < GMT_count_channels (t))
1343 GMT_destroy_empty (t);
1348 * Destroy the tunnel.
1350 * This function does not generate any warning traffic to clients or peers.
1353 * Cancel messages belonging to this tunnel queued to neighbors.
1354 * Free any allocated resources linked to the tunnel.
1356 * @param t The tunnel to destroy.
1359 GMT_destroy (struct MeshTunnel3 *t)
1361 struct MeshTConnection *iter;
1362 struct MeshTConnection *next;
1367 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GMP_2s (t->peer));
1369 // if (GNUNET_YES != GNUNET_CONTAINER_multihashmap_remove (tunnels, &t->id, t))
1370 // GNUNET_break (0);
1372 for (iter = t->connection_head; NULL != iter; iter = next)
1375 GMC_destroy (iter->c);
1378 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
1379 GMP_set_tunnel (t->peer, NULL);
1381 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1382 GNUNET_SCHEDULER_cancel (t->rekey_task);
1389 * @brief Use the given path for the tunnel.
1390 * Update the next and prev hops (and RCs).
1391 * (Re)start the path refresh in case the tunnel is locally owned.
1393 * @param t Tunnel to update.
1394 * @param p Path to use.
1396 * @return Connection created.
1398 struct MeshConnection *
1399 GMT_use_path (struct MeshTunnel3 *t, struct MeshPeerPath *p)
1401 struct MeshConnection *c;
1402 struct GNUNET_HashCode cid;
1403 unsigned int own_pos;
1405 if (NULL == t || NULL == p)
1411 for (own_pos = 0; own_pos < p->length; own_pos++)
1413 if (p->peers[own_pos] == myid)
1416 if (own_pos > p->length - 1)
1422 GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE, &cid);
1423 c = GMC_new (&cid, t, p, own_pos);
1424 GMT_add_connection (t, c);
1430 * Count established (ready) connections of a tunnel.
1432 * @param t Tunnel on which to count.
1434 * @return Number of connections.
1437 GMT_count_connections (struct MeshTunnel3 *t)
1439 struct MeshTConnection *iter;
1442 for (count = 0, iter = t->connection_head;
1444 iter = iter->next, count++);
1450 * Count channels of a tunnel.
1452 * @param t Tunnel on which to count.
1454 * @return Number of channels.
1457 GMT_count_channels (struct MeshTunnel3 *t)
1459 struct MeshTChannel *iter;
1462 for (count = 0, iter = t->channel_head;
1464 iter = iter->next, count++) /* skip */;
1471 * Get the state of a tunnel.
1475 * @return Tunnel's state.
1477 enum MeshTunnel3State
1478 GMT_get_state (struct MeshTunnel3 *t)
1481 return (enum MeshTunnel3State) -1;
1486 * Get the total buffer space for a tunnel.
1488 * If terminal, use the biggest channel buffer (or 64) if no channel exists.
1489 * If not terminal, use the sum of all connection buffers.
1492 * @param fwd Is this for FWD traffic?
1494 * @return Buffer space offered by all entities (c/ch) in the tunnel.
1497 GMT_get_buffer (struct MeshTunnel3 *t, int fwd)
1499 struct MeshTConnection *iter;
1500 unsigned int buffer;
1502 iter = t->connection_head;
1505 /* If terminal, return biggest channel buffer */
1506 if (NULL == iter || GMC_is_terminal (iter->c, fwd))
1508 struct MeshTChannel *iter_ch;
1509 unsigned int ch_buf;
1511 if (NULL == t->channel_head)
1513 /* Probably getting buffer for a channel create/handshake. */
1517 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = iter_ch->next)
1519 ch_buf = GMCH_get_buffer (iter_ch->ch, fwd);
1520 if (ch_buf > buffer)
1526 /* If not terminal, return sum of connection buffers */
1527 while (NULL != iter)
1529 if (GMC_get_state (iter->c) != MESH_CONNECTION_READY)
1535 buffer += GMC_get_buffer (iter->c, fwd);
1544 * Get the tunnel's destination.
1548 * @return ID of the destination peer.
1550 const struct GNUNET_PeerIdentity *
1551 GMT_get_destination (struct MeshTunnel3 *t)
1553 return GMP_get_id (t->peer);
1558 * Get the tunnel's next free global channel ID.
1562 * @return GID of a channel free to use.
1565 GMT_get_next_chid (struct MeshTunnel3 *t)
1567 MESH_ChannelNumber chid;
1569 while (NULL != GMT_get_channel (t, t->next_chid))
1571 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
1572 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
1574 chid = t->next_chid;
1575 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
1582 * Send ACK on one or more channels due to buffer in connections.
1584 * @param t Channel which has some free buffer space.
1585 * @param fwd Is this for FWD traffic? (ACK goes to root)
1588 GMT_unchoke_channels (struct MeshTunnel3 *t, int fwd)
1590 struct MeshTChannel *iter;
1591 unsigned int buffer;
1592 unsigned int channels = GMT_count_channels (t);
1593 unsigned int choked_n;
1594 struct MeshChannel *choked[channels];
1596 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT_unchoke_channels on %s\n", GMT_2s (t));
1597 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
1598 if (NULL != t->channel_head)
1599 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
1607 /* Get buffer space */
1608 buffer = GMT_get_buffer (t, fwd);
1614 /* Count and remember choked channels */
1616 for (iter = t->channel_head; NULL != iter; iter = iter->next)
1618 if (GNUNET_NO == GMCH_get_allowed (iter->ch, fwd))
1620 choked[choked_n++] = iter->ch;
1624 /* Unchoke random channels */
1625 while (0 < buffer && 0 < choked_n)
1627 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1629 GMCH_allow_client (choked[r], fwd);
1632 choked[r] = choked[choked_n];
1638 * Send ACK on one or more connections due to buffer space to the client.
1640 * Iterates all connections of the tunnel and sends ACKs appropriately.
1643 * @param fwd Is this in for FWD traffic? (ACK goes dest->root)
1646 GMT_send_acks (struct MeshTunnel3 *t, int fwd)
1648 struct MeshTConnection *iter;
1651 uint32_t allow_per_connection;
1653 unsigned int buffer;
1655 LOG (GNUNET_ERROR_TYPE_DEBUG,
1656 "Tunnel send %s ACKs on %s\n",
1657 fwd ? "FWD" : "BCK", GMT_2s (t));
1664 if (NULL == t->channel_head ||
1665 GNUNET_NO == GMCH_is_origin (t->channel_head->ch, !fwd))
1671 buffer = GMT_get_buffer (t, fwd);
1673 /* Count connections, how many messages are already allowed */
1674 cs = GMT_count_connections (t);
1675 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
1677 allowed += GMC_get_allowed (iter->c, fwd);
1680 /* Make sure there is no overflow */
1681 if (allowed > buffer)
1687 /* Authorize connections to send more data */
1688 to_allow = buffer; /* - allowed; */
1690 for (iter = t->connection_head; NULL != iter && to_allow > 0; iter = iter->next)
1692 allow_per_connection = to_allow/cs;
1693 to_allow -= allow_per_connection;
1695 if (GMC_get_allowed (iter->c, fwd) > 64 / 3)
1699 GMC_allow (iter->c, buffer, fwd);
1702 GNUNET_break (to_allow == 0);
1707 * Sends an already built message on a tunnel, encrypting it and
1708 * choosing the best connection.
1710 * @param message Message to send. Function modifies it.
1711 * @param t Tunnel on which this message is transmitted.
1712 * @param ch Channel on which this message is transmitted.
1713 * @param fwd Is this a fwd message?
1716 GMT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1717 struct MeshTunnel3 *t,
1718 struct MeshChannel *ch,
1721 struct MeshConnection *c;
1722 struct GNUNET_MESH_Encrypted *msg;
1723 size_t size = ntohs (message->size);
1724 size_t encrypted_size;
1725 char *cbuf[sizeof (struct GNUNET_MESH_Encrypted) + size + 64];
1729 if (MESH_TUNNEL3_READY != t->state)
1731 queue_data (t, ch, message, fwd);
1734 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GMT_2s (t));
1736 iv = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_NONCE, UINT64_MAX);
1737 msg = (struct GNUNET_MESH_Encrypted *) cbuf;
1738 msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED);
1739 msg->iv = GNUNET_htonll (iv);
1740 encrypted_size = t_encrypt (t, &msg[1], message, size, iv);
1741 msg->header.size = htons (sizeof (struct GNUNET_MESH_Encrypted) + encrypted_size);
1742 c = tunnel_get_connection (t, fwd);
1745 GNUNET_break (GNUNET_YES == t->destroy);
1748 type = ntohs (message->type);
1751 case GNUNET_MESSAGE_TYPE_MESH_DATA:
1752 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
1753 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
1754 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
1755 msg->cid = *GMC_get_id (c);
1756 msg->ttl = htonl (default_ttl);
1759 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1760 GNUNET_MESH_DEBUG_M2S (type));
1764 GMC_send_prebuilt_message (&msg->header, c, fwd);
1768 * Is the tunnel directed towards the local peer?
1772 * @return #GNUNET_YES if it is loopback.
1775 GMT_is_loopback (const struct MeshTunnel3 *t)
1777 return (myid == GMP_get_short_id(t->peer));
1782 * Is the tunnel using this path already?
1787 * @return #GNUNET_YES a connection uses this path.
1790 GMT_is_path_used (const struct MeshTunnel3 *t, const struct MeshPeerPath *p)
1792 struct MeshTConnection *iter;
1794 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1795 if (GMC_get_path (iter->c) == p)
1803 * Get a cost of a path for a tunnel considering existing connections.
1806 * @param path Candidate path.
1808 * @return Cost of the path (path length + number of overlapping nodes)
1811 GMT_get_path_cost (const struct MeshTunnel3 *t,
1812 const struct MeshPeerPath *path)
1814 struct MeshTConnection *iter;
1815 unsigned int overlap;
1823 GNUNET_assert (NULL != t);
1825 for (i = 0; i < path->length; i++)
1827 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1829 for (j = 0; j < GMC_get_path (iter->c)->length; j++)
1831 if (path->peers[i] == GMC_get_path (iter->c)->peers[j])
1839 return (path->length + overlap) * (path->score * -1);
1844 * Get the static string for the peer this tunnel is directed.
1848 * @return Static string the destination peer's ID.
1851 GMT_2s (const struct MeshTunnel3 *t)
1853 return GMP_2s (t->peer);