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- /*
- This file is part of GNUnet.
- (C) 2007-2013 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 cadet topology
- * @author Christian Grothoff
- */
- #include "platform.h"
- #include "gnunet_util_lib.h"
- #include "gnunet_friends_lib.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"
- /**
- * Minimum required delay between calls to GNUNET_TRANSPORT_try_connect.
- */
- #define MAX_CONNECT_FREQUENCY_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 250)
- /**
- * Maximum delay allowed delay between calls to GNUNET_TRANSPORT_try_connect.
- */
- #define MIN_CONNECT_FREQUENCY_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 2500)
- /**
- * For how long do we blacklist a peer after a failed connection
- * attempt? This is the baseline factor which is then multiplied by
- * two to the power of the number of failed attempts.
- */
- #define GREYLIST_AFTER_ATTEMPT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 1)
- /**
- * For how long do we blacklist a friend after a failed connection
- * attempt? This is the baseline factor which is then multiplied by
- * two to the power of the number of failed attempts.
- */
- #define GREYLIST_AFTER_ATTEMPT_FRIEND GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 2)
- /**
- * For how long do we blacklist anyone under any cirumstances at least after a failed connection
- * attempt? This is the absolute minimum, regardless of what the calculation based on
- * exponential backoff returns.
- */
- #define GREYLIST_AFTER_ATTEMPT_MIN GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
- /**
- * For how long do we blacklist anyone under any cirumstances at most after a failed connection
- * attempt? This is the absolute maximum, regardless of what the calculation based on
- * exponential back-off returns.
- */
- #define GREYLIST_AFTER_ATTEMPT_MAX GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 1)
- /**
- * At what frequency do we sent HELLOs to a peer?
- */
- #define HELLO_ADVERTISEMENT_MIN_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5)
- /**
- * After what time period do we expire the HELLO Bloom filter?
- */
- #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;
- /**
- * When should try next connection attempt?
- */
- struct GNUNET_TIME_Absolute next_connect_attempt;
- /**
- * ID of task we use to wait for the time to send the next HELLO
- * to this peer.
- */
- GNUNET_SCHEDULER_TaskIdentifier hello_delay_task;
- /**
- * Task for issuing GNUNET_TRANSPORT_try_connect for this peer.
- */
- GNUNET_SCHEDULER_TaskIdentifier attempt_connect_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_MultiPeerMap *peers;
- /**
- * Handle for reporting statistics.
- */
- static struct GNUNET_STATISTICS_Handle *stats;
- /**
- * Blacklist (NULL if we have none).
- */
- static struct GNUNET_TRANSPORT_Blacklist *blacklist;
- /**
- * When can we next ask transport to create a connection?
- */
- static struct GNUNET_TIME_Absolute next_connect_attempt;
- /**
- * 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;
- /**
- * 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 disapprove
- * @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_multipeermap_get (peers, pid);
- 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)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Determined that `%s' is not allowed to connect (not a friend)\n",
- GNUNET_i2s (&peer->pid));
- return GNUNET_SYSERR;
- }
- if (friend_count >= minimum_friend_count)
- return GNUNET_OK;
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Determined that `%s' is not allowed to connect (not enough connected friends)\n",
- GNUNET_i2s (&peer->pid));
- 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 struct GNUNET_PeerIdentity * pid, void *value)
- {
- struct Peer *pos = value;
- GNUNET_break (GNUNET_NO == pos->is_connected);
- GNUNET_break (GNUNET_OK ==
- GNUNET_CONTAINER_multipeermap_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->attempt_connect_task != GNUNET_SCHEDULER_NO_TASK)
- GNUNET_SCHEDULER_cancel (pos->attempt_connect_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_us > 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;
- else
- pos->connect_attempts ++;
- 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);
- pos->next_connect_attempt = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(),
- GNUNET_TIME_relative_multiply (MAX_CONNECT_FREQUENCY_DELAY, pos->connect_attempts));
- pos->next_connect_attempt = GNUNET_TIME_absolute_min (pos->next_connect_attempt,
- GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), MIN_CONNECT_FREQUENCY_DELAY));
- 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);
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Asking to connect to `%s'\n",
- GNUNET_i2s (&pos->pid));
- GNUNET_STATISTICS_update (stats,
- gettext_noop
- ("# connect requests issued to transport"), 1,
- GNUNET_NO);
- GNUNET_TRANSPORT_try_connect (transport, &pos->pid, NULL, NULL);
- }
- /**
- * Try to connect to the specified peer.
- *
- * @param cls peer to connect to
- * @param tc scheduler context
- */
- static void
- do_attempt_connect (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc)
- {
- struct Peer *pos = cls;
- struct GNUNET_TIME_Relative delay;
- pos->attempt_connect_task = GNUNET_SCHEDULER_NO_TASK;
- if (GNUNET_YES == pos->is_connected)
- return;
- /* Try next connection attempt, when:
- * - topology allows the next transport connection attempt
- * and
- * - the next connection event for this peer is allowed
- */
- delay = GNUNET_TIME_relative_max (GNUNET_TIME_absolute_get_remaining (next_connect_attempt),
- GNUNET_TIME_absolute_get_remaining (pos->next_connect_attempt));
- if (delay.rel_value_us > 0)
- {
- pos->attempt_connect_task = GNUNET_SCHEDULER_add_delayed (delay,
- &do_attempt_connect,
- pos);
- return;
- }
- next_connect_attempt = GNUNET_TIME_relative_to_absolute (MAX_CONNECT_FREQUENCY_DELAY);
- attempt_connect (pos);
- }
- /**
- * Schedule a task to try to connect to the specified peer.
- *
- * @param pos peer to connect to
- */
- static void
- schedule_attempt_connect (struct Peer *pos)
- {
- if (GNUNET_SCHEDULER_NO_TASK != pos->attempt_connect_task)
- return;
- pos->attempt_connect_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining (next_connect_attempt),
- &do_attempt_connect,
- pos);
- }
- /**
- * 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 (0 == rem.rel_value_us)
- {
- schedule_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, 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_new (struct Peer);
- ret->pid = *peer;
- ret->is_friend = is_friend;
- ret->next_connect_attempt = GNUNET_TIME_absolute_get();
- 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_multipeermap_put (peers, peer,
- 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)
- {
- struct GNUNET_HashCode hc;
- /* 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_CRYPTO_hash (&peer->pid, sizeof (struct GNUNET_PeerIdentity), &hc);
- GNUNET_CONTAINER_bloomfilter_add (peer->filter, &hc);
- }
- /**
- * Function to fill send buffer with HELLO.
- *
- * @param cls 'struct Peer' of the target peer
- * @param size number of bytes available in @a buf
- * @param buf where the callee should write the message
- * @return number of bytes written to @a 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 struct GNUNET_PeerIdentity * pid, void *value)
- {
- struct FindAdvHelloContext *fah = cls;
- struct Peer *pos = value;
- struct GNUNET_TIME_Relative rst_time;
- struct GNUNET_HashCode hc;
- 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_us)
- {
- /* 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;
- GNUNET_CRYPTO_hash (&fah->peer->pid, sizeof (struct GNUNET_PeerIdentity), &hc);
- if (GNUNET_NO ==
- GNUNET_CONTAINER_bloomfilter_test (pos->filter,
- &hc))
- 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_multipeermap_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 (0 == delay.rel_value_us)
- {
- /* now! */
- pl->hello_req =
- GNUNET_CORE_notify_transmit_ready (handle, GNUNET_YES,
- GNUNET_CORE_PRIO_BEST_EFFORT,
- 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 struct GNUNET_PeerIdentity * 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
- */
- static void
- connect_notify (void *cls, const struct GNUNET_PeerIdentity *peer)
- {
- struct Peer *pos;
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Core told us that we are connecting to `%s'\n",
- GNUNET_i2s (peer));
- 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_multipeermap_get (peers, peer);
- if (NULL == pos)
- {
- 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_us = 0; /* remove greylisting */
- }
- pos->is_connected = GNUNET_YES;
- pos->connect_attempts = 0; /* re-set back-off factor */
- pos->next_connect_attempt = GNUNET_TIME_absolute_get(); /* 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, 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 struct GNUNET_PeerIdentity * pid, void *value)
- {
- struct Peer *pos = value;
- schedule_attempt_connect (pos);
- return GNUNET_YES;
- }
- /**
- * Add peers and schedule connection attempt
- *
- * @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_multipeermap_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;
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Core told us that we disconnected from `%s'\n",
- GNUNET_i2s (peer));
- pos = GNUNET_CONTAINER_multipeermap_get (peers, peer);
- if (NULL == pos)
- {
- 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_multipeermap_get (peers, &pid);
- if (NULL == peer)
- {
- 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_us == GNUNET_TIME_UNIT_FOREVER_ABS.abs_value_us)
- return; /* nothing new here */
- }
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Found `%s' from peer `%s' for advertising\n", "HELLO",
- GNUNET_i2s (&pid));
- 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_multipeermap_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, GNUNET_NO, &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_multipeermap_get (peers, peer);
- 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 ((GNUNET_NO == pos->is_connected) && (GNUNET_NO == pos->is_friend) &&
- (0 ==
- GNUNET_TIME_absolute_get_remaining (pos->
- greylisted_until).rel_value_us))
- free_peer (NULL, &pos->pid, pos);
- }
- return;
- }
- consider_for_advertising (hello);
- pos = GNUNET_CONTAINER_multipeermap_get (peers, peer);
- if (pos == NULL)
- pos = make_peer (peer, hello, GNUNET_NO);
- GNUNET_assert (NULL != pos);
- if (GNUNET_YES == pos->is_connected)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Already connected to peer `%s'\n",
- GNUNET_i2s (peer));
- return;
- }
- if (GNUNET_TIME_absolute_get_remaining (pos->greylisted_until).rel_value_us > 0)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Already tried peer `%s' recently\n",
- GNUNET_i2s (peer));
- return; /* peer still greylisted */
- }
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Considering connecting to peer `%s'\n",
- GNUNET_i2s (peer));
- schedule_attempt_connect (pos);
- }
- /**
- * Function called after #GNUNET_CORE_connect has succeeded
- * (or failed for good).
- *
- * @param cls closure
- * @param my_id ID of this peer, NULL if we failed
- */
- static void
- core_init (void *cls,
- const struct GNUNET_PeerIdentity *my_id)
- {
- if (NULL == my_id)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _
- ("Failed to connect to core service, can not manage topology!\n"));
- GNUNET_SCHEDULER_shutdown ();
- return;
- }
- my_identity = *my_id;
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "I am peer `%s'\n",
- GNUNET_i2s (my_id));
- peerinfo_notify = GNUNET_PEERINFO_notify (cfg, GNUNET_NO,
- &process_peer, NULL);
- }
- /**
- * Process friend found in FRIENDS file.
- *
- * @param cls pointer to an `unsigned int` to be incremented per friend found
- * @param pid identity of the friend
- */
- static void
- handle_friend (void *cls,
- const struct GNUNET_PeerIdentity *pid)
- {
- unsigned int *entries_found = cls;
- struct Peer *fl;
- if (0 == memcmp (pid, &my_identity, sizeof (struct GNUNET_PeerIdentity)))
- {
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Found myself `%s' in friend list (useless, ignored)\n"),
- GNUNET_i2s (pid));
- return;
- }
- (*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));
- }
- /**
- * Read the friends file.
- */
- static void
- read_friends_file (const struct GNUNET_CONFIGURATION_Handle *cfg)
- {
- unsigned int entries_found;
- entries_found = 0;
- if (GNUNET_OK !=
- GNUNET_FRIENDS_parse (cfg,
- &handle_friend,
- &entries_found))
- {
- if ((friends_only) || (minimum_friend_count > 0))
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Encountered errors parsing friends list!\n"));
- }
- 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
- * @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)
- {
- struct Peer *peer;
- struct GNUNET_PeerIdentity pid;
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received encrypted `%s' from peer `%s'",
- "HELLO", GNUNET_i2s (other));
- 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_multipeermap_get (peers, &pid);
- if (NULL == peer)
- {
- 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;
- struct GNUNET_HashCode hc;
- 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_multipeermap_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_CRYPTO_hash (&pl->pid, sizeof (struct GNUNET_PeerIdentity), &hc);
- GNUNET_CONTAINER_bloomfilter_add (fah.result->filter, &hc);
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending `%s' with %u bytes", "HELLO",
- (unsigned int) want);
- 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;
- }
- GNUNET_TRANSPORT_disconnect (transport);
- transport = NULL;
- if (handle != NULL)
- {
- GNUNET_CORE_disconnect (handle);
- handle = NULL;
- }
- whitelist_peers ();
- if (GNUNET_SCHEDULER_NO_TASK != add_task)
- {
- GNUNET_SCHEDULER_cancel (add_task);
- add_task = GNUNET_SCHEDULER_NO_TASK;
- }
- GNUNET_CONTAINER_multipeermap_iterate (peers, &free_peer, NULL);
- GNUNET_CONTAINER_multipeermap_destroy (peers);
- peers = NULL;
- 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);
- 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_multipeermap_create (target_connection_count * 2, GNUNET_NO);
- if ((friends_only == GNUNET_YES) || (minimum_friend_count > 0))
- read_friends_file (cfg);
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Topology would like %u connections with at least %u friends\n",
- target_connection_count, minimum_friend_count);
- 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, 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;
- if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
- return 2;
- ret =
- (GNUNET_OK ==
- GNUNET_PROGRAM_run (argc, argv, "gnunet-daemon-topology",
- _
- ("GNUnet topology control (maintaining P2P cadet and F2F constraints)"),
- options, &run, NULL)) ? 0 : 1;
- GNUNET_free ((void*) argv);
- return ret;
- }
- #ifdef LINUX
- #include <malloc.h>
- /**
- * MINIMIZE heap size (way below 128k) since this process doesn't need much.
- */
- void __attribute__ ((constructor)) GNUNET_ARM_memory_init ()
- {
- mallopt (M_TRIM_THRESHOLD, 4 * 1024);
- mallopt (M_TOP_PAD, 1 * 1024);
- malloc_trim (0);
- }
- #endif
- /* end of gnunet-daemon-topology.c */
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