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Diffstat (limited to 'src/topology/gnunet-daemon-topology.c')
| -rw-r--r-- | src/topology/gnunet-daemon-topology.c | 1328 |
1 files changed, 1328 insertions, 0 deletions
diff --git a/src/topology/gnunet-daemon-topology.c b/src/topology/gnunet-daemon-topology.c new file mode 100644 index 0000000..38a648a --- /dev/null +++ b/src/topology/gnunet-daemon-topology.c @@ -0,0 +1,1328 @@ +/* + This file is part of GNUnet. + (C) 2007, 2008, 2009, 2010 Christian Grothoff (and other contributing authors) + + GNUnet is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 3, or (at your + option) any later version. + + GNUnet is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNUnet; see the file COPYING. If not, write to the + Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. +*/ + +/** + * @file topology/gnunet-daemon-topology.c + * @brief code for maintaining the mesh topology + * @author Christian Grothoff + */ + +#include <stdlib.h> +#include "platform.h" +#include "gnunet_constants.h" +#include "gnunet_core_service.h" +#include "gnunet_protocols.h" +#include "gnunet_peerinfo_service.h" +#include "gnunet_statistics_service.h" +#include "gnunet_transport_service.h" +#include "gnunet_util_lib.h" + + +#define DEBUG_TOPOLOGY GNUNET_YES + +/** + * For how long do we blacklist a peer after a failed connection + * attempt? + */ +#define GREYLIST_AFTER_ATTEMPT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15) + +/** + * For how long do we blacklist a friend after a failed connection + * attempt? + */ +#define GREYLIST_AFTER_ATTEMPT_FRIEND GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 2) + +/** + * For how long do we blacklist anyone under any cirumstances after a failed connection + * attempt? + */ +#define GREYLIST_AFTER_ATTEMPT_MIN GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 15) + +/** + * For how long do we blacklist anyone under any cirumstances after a failed connection + * attempt? + */ +#define GREYLIST_AFTER_ATTEMPT_MAX GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 1) + +/** + * How often do we at most advertise any HELLO to a peer? + */ +#define HELLO_ADVERTISEMENT_MIN_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 4) + +/** + * How often do we at most advertise the same HELLO to the same peer? + */ +#define HELLO_ADVERTISEMENT_MIN_REPEAT_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 4) + + +/** + * Record for neighbours, friends and blacklisted peers. + */ +struct Peer +{ + /** + * Which peer is this entry about? + */ + struct GNUNET_PeerIdentity pid; + + /** + * Our handle for the request to transmit HELLOs to this peer; NULL + * if no such request is pending. + */ + struct GNUNET_CORE_TransmitHandle *hello_req; + + /** + * Pointer to the HELLO message of this peer; can be NULL. + */ + struct GNUNET_HELLO_Message *hello; + + /** + * Bloom filter used to mark which peers already got the HELLO + * from this peer. + */ + struct GNUNET_CONTAINER_BloomFilter *filter; + + /** + * Until what time should we not try to connect again + * to this peer? + */ + struct GNUNET_TIME_Absolute greylisted_until; + + /** + * Next time we are allowed to transmit a HELLO to this peer? + */ + struct GNUNET_TIME_Absolute next_hello_allowed; + + /** + * When should we reset the bloom filter of this entry? + */ + struct GNUNET_TIME_Absolute filter_expiration; + + /** + * ID of task we use to wait for the time to send the next HELLO + * to this peer. + */ + GNUNET_SCHEDULER_TaskIdentifier hello_delay_task; + + /** + * ID of task we use to clear peers from the greylist. + */ + GNUNET_SCHEDULER_TaskIdentifier greylist_clean_task; + + /** + * How often have we tried so far? + */ + unsigned int connect_attempts; + + /** + * Is this peer listed here because he is a friend? + */ + int is_friend; + + /** + * Are we connected to this peer right now? + */ + int is_connected; + +}; + + +/** + * Our peerinfo notification context. We use notification + * to instantly learn about new peers as they are discovered. + */ +static struct GNUNET_PEERINFO_NotifyContext *peerinfo_notify; + +/** + * Our configuration. + */ +static const struct GNUNET_CONFIGURATION_Handle *cfg; + +/** + * Handle to the core API. + */ +static struct GNUNET_CORE_Handle *handle; + +/** + * Handle to the transport API. + */ +static struct GNUNET_TRANSPORT_Handle *transport; + +/** + * Identity of this peer. + */ +static struct GNUNET_PeerIdentity my_identity; + +/** + * All of our friends, all of our current neighbours and all peers for + * which we have HELLOs. So pretty much everyone. Maps peer identities + * to 'struct Peer *' values. + */ +static struct GNUNET_CONTAINER_MultiHashMap *peers; + +/** + * Handle for reporting statistics. + */ +static struct GNUNET_STATISTICS_Handle *stats; + +/** + * Blacklist (NULL if we have none). + */ +static struct GNUNET_TRANSPORT_Blacklist *blacklist; + +/** + * Task scheduled to try to add peers. + */ +static GNUNET_SCHEDULER_TaskIdentifier add_task; + +/** + * Flag to disallow non-friend connections (pure F2F mode). + */ +static int friends_only; + +/** + * Minimum number of friends to have in the + * connection set before we allow non-friends. + */ +static unsigned int minimum_friend_count; + +/** + * Number of peers (friends and others) that we are currently connected to. + */ +static unsigned int connection_count; + +/** + * Target number of connections. + */ +static unsigned int target_connection_count; + +/** + * Number of friends that we are currently connected to. + */ +static unsigned int friend_count; + +/** + * Should the topology daemon try to establish connections? + */ +static int autoconnect; + + +/** + * Function that decides if a connection is acceptable or not. + * If we have a blacklist, only friends are allowed, so the check + * is rather simple. + * + * @param cls closure + * @param pid peer to approve or disapproave + * @return GNUNET_OK if the connection is allowed + */ +static int +blacklist_check (void *cls, const struct GNUNET_PeerIdentity *pid) +{ + struct Peer *pos; + + pos = GNUNET_CONTAINER_multihashmap_get (peers, &pid->hashPubKey); + if ((pos != NULL) && (pos->is_friend == GNUNET_YES)) + return GNUNET_OK; + GNUNET_STATISTICS_update (stats, gettext_noop ("# peers blacklisted"), 1, + GNUNET_NO); + return GNUNET_SYSERR; +} + + +/** + * Whitelist all peers that we blacklisted; we've passed + * the minimum number of friends. + */ +static void +whitelist_peers () +{ + if (blacklist != NULL) + { + GNUNET_TRANSPORT_blacklist_cancel (blacklist); + blacklist = NULL; + } +} + + +/** + * Check if an additional connection from the given peer is allowed. + * + * @param peer connection to check + * @return GNUNET_OK if the connection is allowed + */ +static int +is_connection_allowed (struct Peer *peer) +{ + if (0 == + memcmp (&my_identity, &peer->pid, sizeof (struct GNUNET_PeerIdentity))) + return GNUNET_SYSERR; /* disallow connections to self */ + if (peer->is_friend) + return GNUNET_OK; + if (GNUNET_YES == friends_only) + { +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Determined that `%s' is not allowed to connect (not a friend)\n", + GNUNET_i2s (&peer->pid)); +#endif + return GNUNET_SYSERR; + } + if (friend_count >= minimum_friend_count) + return GNUNET_OK; +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Determined that `%s' is not allowed to connect (not enough connected friends)\n", + GNUNET_i2s (&peer->pid)); +#endif + return GNUNET_SYSERR; +} + + +/** + * Free all resources associated with the given peer. + * + * @param cls closure (not used) + * @param pid identity of the peer + * @param value peer to free + * @return GNUNET_YES (always: continue to iterate) + */ +static int +free_peer (void *cls, const GNUNET_HashCode * pid, void *value) +{ + struct Peer *pos = value; + + GNUNET_break (GNUNET_OK == + GNUNET_CONTAINER_multihashmap_remove (peers, pid, pos)); + if (pos->hello_req != NULL) + GNUNET_CORE_notify_transmit_ready_cancel (pos->hello_req); + if (pos->hello_delay_task != GNUNET_SCHEDULER_NO_TASK) + GNUNET_SCHEDULER_cancel (pos->hello_delay_task); + if (pos->greylist_clean_task != GNUNET_SCHEDULER_NO_TASK) + GNUNET_SCHEDULER_cancel (pos->greylist_clean_task); + GNUNET_free_non_null (pos->hello); + if (pos->filter != NULL) + GNUNET_CONTAINER_bloomfilter_free (pos->filter); + GNUNET_free (pos); + return GNUNET_YES; +} + + +/** + * Discard peer entries for greylisted peers + * where the greylisting has expired. + * + * @param cls 'struct Peer' to greylist + * @param tc scheduler context + */ +static void +remove_from_greylist (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc); + + +/** + * Try to connect to the specified peer. + * + * @param pos peer to connect to + */ +static void +attempt_connect (struct Peer *pos) +{ + struct GNUNET_TIME_Relative rem; + + if ((connection_count >= target_connection_count) && + (friend_count >= minimum_friend_count)) + return; + if (GNUNET_YES == pos->is_connected) + return; + if (GNUNET_OK != is_connection_allowed (pos)) + return; + if (GNUNET_TIME_absolute_get_remaining (pos->greylisted_until).rel_value > 0) + return; + if (GNUNET_YES == pos->is_friend) + rem = GREYLIST_AFTER_ATTEMPT_FRIEND; + else + rem = GREYLIST_AFTER_ATTEMPT; + rem = GNUNET_TIME_relative_multiply (rem, connection_count); + rem = GNUNET_TIME_relative_divide (rem, target_connection_count); + if (pos->connect_attempts > 30) + pos->connect_attempts = 30; + rem = GNUNET_TIME_relative_multiply (rem, 1 << (++pos->connect_attempts)); + rem = GNUNET_TIME_relative_max (rem, GREYLIST_AFTER_ATTEMPT_MIN); + rem = GNUNET_TIME_relative_min (rem, GREYLIST_AFTER_ATTEMPT_MAX); + pos->greylisted_until = GNUNET_TIME_relative_to_absolute (rem); + if (pos->greylist_clean_task != GNUNET_SCHEDULER_NO_TASK) + GNUNET_SCHEDULER_cancel (pos->greylist_clean_task); + pos->greylist_clean_task = + GNUNET_SCHEDULER_add_delayed (rem, &remove_from_greylist, pos); +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Asking to connect to `%s'\n", + GNUNET_i2s (&pos->pid)); +#endif + GNUNET_STATISTICS_update (stats, + gettext_noop + ("# connect requests issued to transport"), 1, + GNUNET_NO); + GNUNET_TRANSPORT_try_connect (transport, &pos->pid); +} + + +/** + * Discard peer entries for greylisted peers + * where the greylisting has expired. + * + * @param cls 'struct Peer' to greylist + * @param tc scheduler context + */ +static void +remove_from_greylist (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct Peer *pos = cls; + struct GNUNET_TIME_Relative rem; + + pos->greylist_clean_task = GNUNET_SCHEDULER_NO_TASK; + rem = GNUNET_TIME_absolute_get_remaining (pos->greylisted_until); + if (rem.rel_value == 0) + { + attempt_connect (pos); + } + else + { + pos->greylist_clean_task = + GNUNET_SCHEDULER_add_delayed (rem, &remove_from_greylist, pos); + } + if ((GNUNET_NO == pos->is_friend) && (GNUNET_NO == pos->is_connected) && + (NULL == pos->hello)) + { + free_peer (NULL, &pos->pid.hashPubKey, pos); + return; + } +} + + +/** + * Create a new entry in the peer list. + * + * @param peer identity of the new entry + * @param hello hello message, can be NULL + * @param is_friend is the new entry for a friend? + * @return the new entry + */ +static struct Peer * +make_peer (const struct GNUNET_PeerIdentity *peer, + const struct GNUNET_HELLO_Message *hello, int is_friend) +{ + struct Peer *ret; + + ret = GNUNET_malloc (sizeof (struct Peer)); + ret->pid = *peer; + ret->is_friend = is_friend; + if (hello != NULL) + { + ret->hello = GNUNET_malloc (GNUNET_HELLO_size (hello)); + memcpy (ret->hello, hello, GNUNET_HELLO_size (hello)); + } + GNUNET_break (GNUNET_OK == + GNUNET_CONTAINER_multihashmap_put (peers, &peer->hashPubKey, + ret, + GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)); + return ret; +} + + +/** + * Setup bloom filter for the given peer entry. + * + * @param peer entry to initialize + */ +static void +setup_filter (struct Peer *peer) +{ + /* 2^{-5} chance of not sending a HELLO to a peer is + * acceptably small (if the filter is 50% full); + * 64 bytes of memory are small compared to the rest + * of the data structure and would only really become + * "useless" once a HELLO has been passed on to ~100 + * other peers, which is likely more than enough in + * any case; hence 64, 5 as bloomfilter parameters. */ + peer->filter = GNUNET_CONTAINER_bloomfilter_init (NULL, 64, 5); + peer->filter_expiration = + GNUNET_TIME_relative_to_absolute + (HELLO_ADVERTISEMENT_MIN_REPEAT_FREQUENCY); + /* never send a peer its own HELLO */ + GNUNET_CONTAINER_bloomfilter_add (peer->filter, &peer->pid.hashPubKey); +} + + +/** + * Function to fill send buffer with HELLO. + * + * @param cls 'struct Peer' of the target peer + * @param size number of bytes available in buf + * @param buf where the callee should write the message + * @return number of bytes written to buf + */ +static size_t +hello_advertising_ready (void *cls, size_t size, void *buf); + + +/** + * Closure for 'find_advertisable_hello'. + */ +struct FindAdvHelloContext +{ + + /** + * Peer we want to advertise to. + */ + struct Peer *peer; + + /** + * Where to store the result (peer selected for advertising). + */ + struct Peer *result; + + /** + * Maximum HELLO size we can use right now. + */ + size_t max_size; + + struct GNUNET_TIME_Relative next_adv; +}; + + +/** + * Find a peer that would be reasonable for advertising. + * + * @param cls closure + * @param pid identity of a peer + * @param value 'struct Peer*' for the peer we are considering + * @return GNUNET_YES (continue iteration) + */ +static int +find_advertisable_hello (void *cls, const GNUNET_HashCode * pid, void *value) +{ + struct FindAdvHelloContext *fah = cls; + struct Peer *pos = value; + struct GNUNET_TIME_Relative rst_time; + size_t hs; + + if (pos == fah->peer) + return GNUNET_YES; + if (pos->hello == NULL) + return GNUNET_YES; + rst_time = GNUNET_TIME_absolute_get_remaining (pos->filter_expiration); + if (0 == rst_time.rel_value) + { + /* time to discard... */ + GNUNET_CONTAINER_bloomfilter_free (pos->filter); + setup_filter (pos); + } + fah->next_adv = GNUNET_TIME_relative_min (rst_time, fah->next_adv); + hs = GNUNET_HELLO_size (pos->hello); + if (hs > fah->max_size) + return GNUNET_YES; + if (GNUNET_NO == + GNUNET_CONTAINER_bloomfilter_test (pos->filter, + &fah->peer->pid.hashPubKey)) + fah->result = pos; + return GNUNET_YES; +} + + +/** + * Calculate when we would like to send the next HELLO to this + * peer and ask for it. + * + * @param cls for which peer to schedule the HELLO + * @param tc task context + */ +static void +schedule_next_hello (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct Peer *pl = cls; + struct FindAdvHelloContext fah; + size_t next_want; + struct GNUNET_TIME_Relative delay; + + pl->hello_delay_task = GNUNET_SCHEDULER_NO_TASK; + GNUNET_assert (GNUNET_YES == pl->is_connected); + if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) + return; /* we're out of here */ + if (pl->hello_req != NULL) + return; /* did not finish sending the previous one */ + /* find applicable HELLOs */ + fah.peer = pl; + fah.result = NULL; + fah.max_size = GNUNET_SERVER_MAX_MESSAGE_SIZE - 1; + fah.next_adv = GNUNET_TIME_UNIT_FOREVER_REL; + GNUNET_CONTAINER_multihashmap_iterate (peers, &find_advertisable_hello, &fah); + pl->hello_delay_task = + GNUNET_SCHEDULER_add_delayed (fah.next_adv, &schedule_next_hello, pl); + if (fah.result == NULL) + return; + next_want = GNUNET_HELLO_size (fah.result->hello); + delay = GNUNET_TIME_absolute_get_remaining (pl->next_hello_allowed); + if (delay.rel_value == 0) + { + /* now! */ + pl->hello_req = + GNUNET_CORE_notify_transmit_ready (handle, GNUNET_YES, 0, + GNUNET_CONSTANTS_SERVICE_TIMEOUT, + &pl->pid, next_want, + &hello_advertising_ready, pl); + } +} + + +/** + * Cancel existing requests for sending HELLOs to this peer + * and recalculate when we should send HELLOs to it based + * on our current state (something changed!). + * + * @param cls closure, 'struct Peer' to skip, or NULL + * @param pid identity of a peer + * @param value 'struct Peer*' for the peer + * @return GNUNET_YES (always) + */ +static int +reschedule_hellos (void *cls, const GNUNET_HashCode * pid, void *value) +{ + struct Peer *peer = value; + struct Peer *skip = cls; + + if (skip == peer) + return GNUNET_YES; + if (!peer->is_connected) + return GNUNET_YES; + if (peer->hello_req != NULL) + { + GNUNET_CORE_notify_transmit_ready_cancel (peer->hello_req); + peer->hello_req = NULL; + } + if (peer->hello_delay_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (peer->hello_delay_task); + peer->hello_delay_task = GNUNET_SCHEDULER_NO_TASK; + } + peer->hello_delay_task = + GNUNET_SCHEDULER_add_now (&schedule_next_hello, peer); + return GNUNET_YES; +} + + +/** + * Method called whenever a peer connects. + * + * @param cls closure + * @param peer peer identity this notification is about + * @param atsi performance data + * @param atsi_count number of records in 'atsi' + */ +static void +connect_notify (void *cls, const struct GNUNET_PeerIdentity *peer, + const struct GNUNET_ATS_Information *atsi, + unsigned int atsi_count) +{ + struct Peer *pos; + +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Core told us that we are connecting to `%s'\n", + GNUNET_i2s (peer)); +#endif + if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity))) + return; + + connection_count++; + GNUNET_STATISTICS_set (stats, gettext_noop ("# peers connected"), + connection_count, GNUNET_NO); + pos = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey); + if (pos == NULL) + { + pos = make_peer (peer, NULL, GNUNET_NO); + GNUNET_break (GNUNET_OK == is_connection_allowed (pos)); + } + else + { + GNUNET_assert (GNUNET_NO == pos->is_connected); + pos->greylisted_until.abs_value = 0; /* remove greylisting */ + } + pos->is_connected = GNUNET_YES; + pos->connect_attempts = 0; /* re-set back-off factor */ + if (pos->is_friend) + { + if ((friend_count == minimum_friend_count - 1) && + (GNUNET_YES != friends_only)) + whitelist_peers (); + friend_count++; + GNUNET_STATISTICS_set (stats, gettext_noop ("# friends connected"), + friend_count, GNUNET_NO); + } + reschedule_hellos (NULL, &peer->hashPubKey, pos); +} + + +/** + * Try to add more peers to our connection set. + * + * @param cls closure, not used + * @param pid identity of a peer + * @param value 'struct Peer*' for the peer + * @return GNUNET_YES (continue to iterate) + */ +static int +try_add_peers (void *cls, const GNUNET_HashCode * pid, void *value) +{ + struct Peer *pos = value; + + attempt_connect (pos); + return GNUNET_YES; +} + + +/** + * Last task run during shutdown. Disconnects us from + * the transport and core. + * + * @param cls unused, NULL + * @param tc scheduler context + */ +static void +add_peer_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + add_task = GNUNET_SCHEDULER_NO_TASK; + + GNUNET_CONTAINER_multihashmap_iterate (peers, &try_add_peers, NULL); +} + +/** + * Method called whenever a peer disconnects. + * + * @param cls closure + * @param peer peer identity this notification is about + */ +static void +disconnect_notify (void *cls, const struct GNUNET_PeerIdentity *peer) +{ + struct Peer *pos; + + if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity))) + return; +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Core told us that we disconnected from `%s'\n", + GNUNET_i2s (peer)); +#endif + pos = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey); + if (pos == NULL) + { + GNUNET_break (0); + return; + } + if (pos->is_connected != GNUNET_YES) + { + GNUNET_break (0); + return; + } + pos->is_connected = GNUNET_NO; + connection_count--; + if (NULL != pos->hello_req) + { + GNUNET_CORE_notify_transmit_ready_cancel (pos->hello_req); + pos->hello_req = NULL; + } + if (GNUNET_SCHEDULER_NO_TASK != pos->hello_delay_task) + { + GNUNET_SCHEDULER_cancel (pos->hello_delay_task); + pos->hello_delay_task = GNUNET_SCHEDULER_NO_TASK; + } + GNUNET_STATISTICS_set (stats, gettext_noop ("# peers connected"), + connection_count, GNUNET_NO); + if (pos->is_friend) + { + friend_count--; + GNUNET_STATISTICS_set (stats, gettext_noop ("# friends connected"), + friend_count, GNUNET_NO); + } + if (((connection_count < target_connection_count) || + (friend_count < minimum_friend_count)) && + (GNUNET_SCHEDULER_NO_TASK == add_task)) + add_task = GNUNET_SCHEDULER_add_now (&add_peer_task, NULL); + if ((friend_count < minimum_friend_count) && (blacklist == NULL)) + blacklist = GNUNET_TRANSPORT_blacklist (cfg, &blacklist_check, NULL); +} + + +/** + * Iterator called on each address. + * + * @param cls flag that we will set if we see any addresses + * @param address the address of the peer + * @param expiration when will the given address expire + * @return GNUNET_SYSERR always, to terminate iteration + */ +static int +address_iterator (void *cls, const struct GNUNET_HELLO_Address *address, + struct GNUNET_TIME_Absolute expiration) +{ + int *flag = cls; + + *flag = GNUNET_YES; + return GNUNET_SYSERR; +} + + +/** + * We've gotten a HELLO from another peer. Consider it for + * advertising. + * + * @param hello the HELLO we got + */ +static void +consider_for_advertising (const struct GNUNET_HELLO_Message *hello) +{ + int have_address; + struct GNUNET_PeerIdentity pid; + struct GNUNET_TIME_Absolute dt; + struct GNUNET_HELLO_Message *nh; + struct Peer *peer; + uint16_t size; + + if (GNUNET_OK != GNUNET_HELLO_get_id (hello, &pid)) + { + GNUNET_break (0); + return; + } + if (0 == memcmp (&pid, &my_identity, sizeof (struct GNUNET_PeerIdentity))) + return; /* that's me! */ + have_address = GNUNET_NO; + GNUNET_HELLO_iterate_addresses (hello, GNUNET_NO, &address_iterator, + &have_address); + if (GNUNET_NO == have_address) + return; /* no point in advertising this one... */ + peer = GNUNET_CONTAINER_multihashmap_get (peers, &pid.hashPubKey); + if (peer == NULL) + { + peer = make_peer (&pid, hello, GNUNET_NO); + } + else if (peer->hello != NULL) + { + dt = GNUNET_HELLO_equals (peer->hello, hello, GNUNET_TIME_absolute_get ()); + if (dt.abs_value == GNUNET_TIME_UNIT_FOREVER_ABS.abs_value) + return; /* nothing new here */ + } +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Found `%s' from peer `%s' for advertising\n", "HELLO", + GNUNET_i2s (&pid)); +#endif + if (peer->hello != NULL) + { + nh = GNUNET_HELLO_merge (peer->hello, hello); + GNUNET_free (peer->hello); + peer->hello = nh; + } + else + { + size = GNUNET_HELLO_size (hello); + peer->hello = GNUNET_malloc (size); + memcpy (peer->hello, hello, size); + } + if (peer->filter != NULL) + GNUNET_CONTAINER_bloomfilter_free (peer->filter); + setup_filter (peer); + /* since we have a new HELLO to pick from, re-schedule all + * HELLO requests that are not bound by the HELLO send rate! */ + GNUNET_CONTAINER_multihashmap_iterate (peers, &reschedule_hellos, peer); +} + + +/** + * PEERINFO calls this function to let us know about a possible peer + * that we might want to connect to. + * + * @param cls closure (not used) + * @param peer potential peer to connect to + * @param hello HELLO for this peer (or NULL) + * @param err_msg NULL if successful, otherwise contains error message + */ +static void +process_peer (void *cls, const struct GNUNET_PeerIdentity *peer, + const struct GNUNET_HELLO_Message *hello, const char *err_msg) +{ + struct Peer *pos; + + if (err_msg != NULL) + { + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + _("Error in communication with PEERINFO service: %s\n"), + err_msg); + GNUNET_PEERINFO_notify_cancel (peerinfo_notify); + peerinfo_notify = GNUNET_PEERINFO_notify (cfg, &process_peer, NULL); + return; + } + GNUNET_assert (peer != NULL); + if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity))) + return; /* that's me! */ + if (hello == NULL) + { + /* free existing HELLO, if any */ + pos = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey); + if (NULL != pos) + { + GNUNET_free_non_null (pos->hello); + pos->hello = NULL; + if (pos->filter != NULL) + { + GNUNET_CONTAINER_bloomfilter_free (pos->filter); + pos->filter = NULL; + } + if ((!pos->is_connected) && (!pos->is_friend) && + (0 == + GNUNET_TIME_absolute_get_remaining (pos-> + greylisted_until).rel_value)) + free_peer (NULL, &pos->pid.hashPubKey, pos); + } + return; + } + consider_for_advertising (hello); + pos = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey); + if (pos == NULL) + pos = make_peer (peer, hello, GNUNET_NO); + GNUNET_assert (NULL != pos); + if (GNUNET_YES == pos->is_connected) + { +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Already connected to peer `%s'\n", + GNUNET_i2s (peer)); +#endif + return; + } + if (GNUNET_TIME_absolute_get_remaining (pos->greylisted_until).rel_value > 0) + { +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Already tried peer `%s' recently\n", + GNUNET_i2s (peer)); +#endif + return; /* peer still greylisted */ + } +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Considering connecting to peer `%s'\n", + GNUNET_i2s (peer)); +#endif + attempt_connect (pos); +} + + +/** + * Function called after GNUNET_CORE_connect has succeeded + * (or failed for good). + * + * @param cls closure + * @param server handle to the server, NULL if we failed + * @param my_id ID of this peer, NULL if we failed + */ +static void +core_init (void *cls, struct GNUNET_CORE_Handle *server, + const struct GNUNET_PeerIdentity *my_id) +{ + if (server == NULL) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _ + ("Failed to connect to core service, can not manage topology!\n")); + GNUNET_SCHEDULER_shutdown (); + return; + } + handle = server; + my_identity = *my_id; +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "I am peer `%s'\n", GNUNET_i2s (my_id)); +#endif + peerinfo_notify = GNUNET_PEERINFO_notify (cfg, &process_peer, NULL); +} + + +/** + * Read the friends file. + */ +static void +read_friends_file (const struct GNUNET_CONFIGURATION_Handle *cfg) +{ + char *fn; + char *data; + size_t pos; + struct GNUNET_PeerIdentity pid; + struct stat frstat; + struct GNUNET_CRYPTO_HashAsciiEncoded enc; + unsigned int entries_found; + struct Peer *fl; + + if (GNUNET_OK != + GNUNET_CONFIGURATION_get_value_filename (cfg, "TOPOLOGY", "FRIENDS", &fn)) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("Option `%s' in section `%s' not specified!\n"), "FRIENDS", + "TOPOLOGY"); + return; + } + if (GNUNET_OK != GNUNET_DISK_file_test (fn)) + GNUNET_DISK_fn_write (fn, NULL, 0, + GNUNET_DISK_PERM_USER_READ | + GNUNET_DISK_PERM_USER_WRITE); + if (0 != STAT (fn, &frstat)) + { + if ((friends_only) || (minimum_friend_count > 0)) + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Could not read friends list `%s'\n"), fn); + GNUNET_free (fn); + return; + } + if (frstat.st_size == 0) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("Friends file `%s' is empty.\n"), + fn); + GNUNET_free (fn); + return; + } + data = GNUNET_malloc_large (frstat.st_size); + if (data == NULL) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Failed to read friends list from `%s': out of memory\n"), + fn); + GNUNET_free (fn); + return; + } + if (frstat.st_size != GNUNET_DISK_fn_read (fn, data, frstat.st_size)) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Failed to read friends list from `%s'\n"), fn); + GNUNET_free (fn); + GNUNET_free (data); + return; + } + entries_found = 0; + pos = 0; + while ((pos < frstat.st_size) && isspace ((unsigned char) data[pos])) + pos++; + while ((frstat.st_size >= sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded)) && + (pos <= + frstat.st_size - sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded))) + { + memcpy (&enc, &data[pos], sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded)); + if (!isspace + ((unsigned char) + enc.encoding[sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1])) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _ + ("Syntax error in topology specification at offset %llu, skipping bytes.\n"), + (unsigned long long) pos); + pos++; + while ((pos < frstat.st_size) && (!isspace ((unsigned char) data[pos]))) + pos++; + continue; + } + enc.encoding[sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1] = '\0'; + if (GNUNET_OK != + GNUNET_CRYPTO_hash_from_string ((char *) &enc, &pid.hashPubKey)) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _ + ("Syntax error in topology specification at offset %llu, skipping bytes `%s'.\n"), + (unsigned long long) pos, &enc); + } + else + { + if (0 != memcmp (&pid, &my_identity, sizeof (struct GNUNET_PeerIdentity))) + { + entries_found++; + fl = make_peer (&pid, NULL, GNUNET_YES); + GNUNET_log (GNUNET_ERROR_TYPE_INFO, + _("Found friend `%s' in configuration\n"), + GNUNET_i2s (&fl->pid)); + } + else + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("Found myself `%s' in friend list (useless, ignored)\n"), + GNUNET_i2s (&pid)); + } + } + pos = pos + sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded); + while ((pos < frstat.st_size) && isspace ((unsigned char) data[pos])) + pos++; + } + GNUNET_free (data); + GNUNET_free (fn); + GNUNET_STATISTICS_update (stats, gettext_noop ("# friends in configuration"), + entries_found, GNUNET_NO); + if ((minimum_friend_count > entries_found) && (friends_only == GNUNET_NO)) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _ + ("Fewer friends specified than required by minimum friend count. Will only connect to friends.\n")); + } + if ((minimum_friend_count > target_connection_count) && + (friends_only == GNUNET_NO)) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _ + ("More friendly connections required than target total number of connections.\n")); + } +} + + +/** + * This function is called whenever an encrypted HELLO message is + * received. + * + * @param cls closure + * @param other the other peer involved (sender or receiver, NULL + * for loopback messages where we are both sender and receiver) + * @param message the actual HELLO message + * @param atsi performance data + * @param atsi_count number of records in 'atsi' + * @return GNUNET_OK to keep the connection open, + * GNUNET_SYSERR to close it (signal serious error) + */ +static int +handle_encrypted_hello (void *cls, const struct GNUNET_PeerIdentity *other, + const struct GNUNET_MessageHeader *message, + const struct GNUNET_ATS_Information *atsi, + unsigned int atsi_count) +{ + struct Peer *peer; + struct GNUNET_PeerIdentity pid; + +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received encrypted `%s' from peer `%s'", + "HELLO", GNUNET_i2s (other)); +#endif + if (GNUNET_OK != + GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) message, &pid)) + { + GNUNET_break_op (0); + return GNUNET_SYSERR; + } + GNUNET_STATISTICS_update (stats, gettext_noop ("# HELLO messages received"), + 1, GNUNET_NO); + peer = GNUNET_CONTAINER_multihashmap_get (peers, &pid.hashPubKey); + if (peer == NULL) + { + if ((GNUNET_YES == friends_only) || (friend_count < minimum_friend_count)) + return GNUNET_OK; + } + else + { + if ((GNUNET_YES != peer->is_friend) && (GNUNET_YES == friends_only)) + return GNUNET_OK; + if ((GNUNET_YES != peer->is_friend) && + (friend_count < minimum_friend_count)) + return GNUNET_OK; + } + if (transport != NULL) + GNUNET_TRANSPORT_offer_hello (transport, message, NULL, NULL); + return GNUNET_OK; +} + + +/** + * Function to fill send buffer with HELLO. + * + * @param cls 'struct Peer' of the target peer + * @param size number of bytes available in buf + * @param buf where the callee should write the message + * @return number of bytes written to buf + */ +static size_t +hello_advertising_ready (void *cls, size_t size, void *buf) +{ + struct Peer *pl = cls; + struct FindAdvHelloContext fah; + size_t want; + + pl->hello_req = NULL; + GNUNET_assert (GNUNET_YES == pl->is_connected); + /* find applicable HELLOs */ + fah.peer = pl; + fah.result = NULL; + fah.max_size = size; + fah.next_adv = GNUNET_TIME_UNIT_FOREVER_REL; + GNUNET_CONTAINER_multihashmap_iterate (peers, &find_advertisable_hello, &fah); + want = 0; + if (fah.result != NULL) + { + want = GNUNET_HELLO_size (fah.result->hello); + GNUNET_assert (want <= size); + memcpy (buf, fah.result->hello, want); + GNUNET_CONTAINER_bloomfilter_add (fah.result->filter, &pl->pid.hashPubKey); +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending `%s' with %u bytes", "HELLO", + (unsigned int) want); +#endif + GNUNET_STATISTICS_update (stats, + gettext_noop ("# HELLO messages gossipped"), 1, + GNUNET_NO); + } + + if (pl->hello_delay_task != GNUNET_SCHEDULER_NO_TASK) + GNUNET_SCHEDULER_cancel (pl->hello_delay_task); + pl->next_hello_allowed = + GNUNET_TIME_relative_to_absolute (HELLO_ADVERTISEMENT_MIN_FREQUENCY); + pl->hello_delay_task = GNUNET_SCHEDULER_add_now (&schedule_next_hello, pl); + return want; +} + + +/** + * Last task run during shutdown. Disconnects us from + * the transport and core. + * + * @param cls unused, NULL + * @param tc scheduler context + */ +static void +cleaning_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + if (NULL != peerinfo_notify) + { + GNUNET_PEERINFO_notify_cancel (peerinfo_notify); + peerinfo_notify = NULL; + } + if (GNUNET_SCHEDULER_NO_TASK != add_task) + { + GNUNET_SCHEDULER_cancel (add_task); + add_task = GNUNET_SCHEDULER_NO_TASK; + } + GNUNET_TRANSPORT_disconnect (transport); + transport = NULL; + GNUNET_CONTAINER_multihashmap_iterate (peers, &free_peer, NULL); + GNUNET_CONTAINER_multihashmap_destroy (peers); + if (handle != NULL) + { + GNUNET_CORE_disconnect (handle); + handle = NULL; + } + whitelist_peers (); + if (stats != NULL) + { + GNUNET_STATISTICS_destroy (stats, GNUNET_NO); + stats = NULL; + } +} + + +/** + * Main function that will be run. + * + * @param cls closure + * @param args remaining command-line arguments + * @param cfgfile name of the configuration file used (for saving, can be NULL!) + * @param c configuration + */ +static void +run (void *cls, char *const *args, const char *cfgfile, + const struct GNUNET_CONFIGURATION_Handle *c) +{ + static struct GNUNET_CORE_MessageHandler handlers[] = { + {&handle_encrypted_hello, GNUNET_MESSAGE_TYPE_HELLO, 0}, + {NULL, 0, 0} + }; + unsigned long long opt; + + cfg = c; + stats = GNUNET_STATISTICS_create ("topology", cfg); + autoconnect = + GNUNET_CONFIGURATION_get_value_yesno (cfg, "TOPOLOGY", "AUTOCONNECT"); + friends_only = + GNUNET_CONFIGURATION_get_value_yesno (cfg, "TOPOLOGY", "FRIENDS-ONLY"); + if (GNUNET_OK != + GNUNET_CONFIGURATION_get_value_number (cfg, "TOPOLOGY", "MINIMUM-FRIENDS", + &opt)) + opt = 0; + minimum_friend_count = (unsigned int) opt; + if (GNUNET_OK != + GNUNET_CONFIGURATION_get_value_number (cfg, "TOPOLOGY", + "TARGET-CONNECTION-COUNT", &opt)) + opt = 16; + target_connection_count = (unsigned int) opt; + peers = GNUNET_CONTAINER_multihashmap_create (target_connection_count * 2); + + if ((friends_only == GNUNET_YES) || (minimum_friend_count > 0)) + read_friends_file (cfg); +#if DEBUG_TOPOLOGY + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Topology would like %u connections with at least %u friends (%s)\n", + target_connection_count, minimum_friend_count, + autoconnect ? "autoconnect enabled" : "autoconnect disabled"); +#endif + if ((friend_count < minimum_friend_count) && (blacklist == NULL)) + blacklist = GNUNET_TRANSPORT_blacklist (cfg, &blacklist_check, NULL); + transport = GNUNET_TRANSPORT_connect (cfg, NULL, NULL, NULL, NULL, NULL); + handle = + GNUNET_CORE_connect (cfg, 1, NULL, &core_init, &connect_notify, + &disconnect_notify, NULL, GNUNET_NO, NULL, GNUNET_NO, + handlers); + GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleaning_task, + NULL); + if (NULL == transport) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Failed to connect to `%s' service.\n"), "transport"); + GNUNET_SCHEDULER_shutdown (); + return; + } + if (NULL == handle) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Failed to connect to `%s' service.\n"), "core"); + GNUNET_SCHEDULER_shutdown (); + return; + } +} + + +/** + * The main function for the topology daemon. + * + * @param argc number of arguments from the command line + * @param argv command line arguments + * @return 0 ok, 1 on error + */ +int +main (int argc, char *const *argv) +{ + static const struct GNUNET_GETOPT_CommandLineOption options[] = { + GNUNET_GETOPT_OPTION_END + }; + int ret; + + ret = + (GNUNET_OK == + GNUNET_PROGRAM_run (argc, argv, "gnunet-daemon-topology", + _ + ("GNUnet topology control (maintaining P2P mesh and F2F constraints)"), + options, &run, NULL)) ? 0 : 1; + return ret; +} + +/* end of gnunet-daemon-topology.c */ |