/*
This file is part of GNUnet.
- (C) 2007, 2008, 2009 Christian Grothoff (and other contributing authors)
+ (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
/**
* @file topology/gnunet-daemon-topology.c
- * @brief code for bootstrapping via topology servers
+ * @brief code for maintaining the mesh topology
* @author Christian Grothoff
*/
#include <stdlib.h>
#include "platform.h"
-#include "gnunet_getopt_lib.h"
+#include "gnunet_core_service.h"
#include "gnunet_protocols.h"
-#include "gnunet_program_lib.h"
-#include "gnunet_statistics_service.h"
-#include "gnunet_strings_lib.h"
-#include "gnunet_time_lib.h"
+#include "gnunet_peerinfo_service.h"
+#include "gnunet_transport_service.h"
+#include "gnunet_util_lib.h"
+#define DEBUG_TOPOLOGY GNUNET_NO
+
/**
- * gnunet-daemon-topology command line options.
+ * For how long do we blacklist a peer after a failed connection
+ * attempt?
*/
-static struct GNUNET_GETOPT_CommandLineOption options[] = {
- GNUNET_GETOPT_OPTION_END
+#define BLACKLIST_AFTER_ATTEMPT GNUNET_TIME_UNIT_HOURS
+
+/**
+ * For how long do we blacklist a friend after a failed connection
+ * attempt?
+ */
+#define BLACKLIST_AFTER_ATTEMPT_FRIEND GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
+
+/**
+ * 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)
+
+
+/**
+ * List of neighbours, friends and blacklisted peers.
+ */
+struct PeerList
+{
+
+ /**
+ * This is a linked list.
+ */
+ struct PeerList *next;
+
+ /**
+ * Our handle for the request to transmit HELLOs to this peer; NULL
+ * if no such request is pending.
+ */
+ struct GNUNET_CORE_TransmitHandle *hello_req;
+
+ /**
+ * Our handle for the request to connect to this peer; NULL if no
+ * such request is pending.
+ */
+ struct GNUNET_CORE_PeerRequestHandle *connect_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;
+
+ /**
+ * Our request handle for *whitelisting* this peer (NULL if
+ * no whitelisting request is pending).
+ */
+ struct GNUNET_TRANSPORT_BlacklistRequest *wh;
+
+ /**
+ * Is this peer listed here because he is a friend?
+ */
+ int is_friend;
+
+ /**
+ * Are we connected to this peer right now?
+ */
+ int is_connected;
+
+ /**
+ * Are we currently blocking this peer (via blacklist)?
+ */
+ int is_blocked;
+
+ /**
+ * Until what time should we not try to connect again
+ * to this peer?
+ */
+ struct GNUNET_TIME_Absolute blacklisted_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 the peer.
+ */
+ struct GNUNET_PeerIdentity id;
+
+};
+
+
+/**
+ * Entry in linked list of active 'disconnect' requests that we have issued.
+ */
+struct DisconnectList
+{
+ /**
+ * This is a doubly-linked list.
+ */
+ struct DisconnectList *next;
+
+ /**
+ * This is a doubly-linked list.
+ */
+ struct DisconnectList *prev;
+
+ /**
+ * Our request handle.
+ */
+ struct GNUNET_TRANSPORT_BlacklistRequest *rh;
+
+ /**
+ * Peer we tried to disconnect.
+ */
+ struct GNUNET_PeerIdentity peer;
+
};
+/**
+ * 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 scheduler.
+ */
+static struct GNUNET_SCHEDULER_Handle *sched;
+
+/**
+ * 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;
+
+/**
+ * Linked list of all of our friends, all of our current neighbours
+ * and all peers for which we have HELLOs. So pretty much everyone.
+ */
+static struct PeerList *peers;
+
+/**
+ * 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;
+
+/**
+ * Head of doubly-linked list of active 'disconnect' requests that we have issued.
+ */
+static struct DisconnectList *disconnect_head;
+
+/**
+ * Head of doubly-linked list of active 'disconnect' requests that we have issued.
+ */
+static struct DisconnectList *disconnect_tail;
+
+
+/**
+ * Function called once our request to 'disconnect' a peer
+ * has completed.
+ *
+ * @param cls our 'struct DisconnectList'
+ * @param tc unused
+ */
+static void
+disconnect_done (void *cls,
+ const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ struct DisconnectList *dl = cls;
+
+ GNUNET_CONTAINER_DLL_remove (disconnect_head,
+ disconnect_tail,
+ dl);
+ GNUNET_free (dl);
+}
+
+
+/**
+ * Force a disconnect from the specified peer.
+ */
+static void
+force_disconnect (struct PeerList *pl)
+{
+ const struct GNUNET_PeerIdentity *peer = &pl->id;
+ struct DisconnectList *dl;
+
+ if (NULL != pl->wh)
+ {
+ GNUNET_TRANSPORT_blacklist_cancel (pl->wh);
+ pl->wh = NULL;
+ }
+ pl->is_blocked = GNUNET_YES;
+ dl = GNUNET_malloc (sizeof (struct DisconnectList));
+ dl->peer = *peer;
+ GNUNET_CONTAINER_DLL_insert (disconnect_head,
+ disconnect_tail,
+ dl);
+ dl->rh = GNUNET_TRANSPORT_blacklist (sched, cfg,
+ peer,
+ GNUNET_TIME_UNIT_FOREVER_REL,
+ GNUNET_TIME_UNIT_FOREVER_REL,
+ &disconnect_done,
+ dl);
+}
+
+
+
+/**
+ * Function called once our request to 'whitelist' a peer
+ * has completed.
+ *
+ * @param cls our 'struct PeerList'
+ * @param tc unused
+ */
+static void
+whitelist_done (void *cls,
+ const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ struct PeerList *pl = cls;
+
+ pl->wh = NULL;
+}
+
+
+/**
+ * Whitelist all peers that we blacklisted; we've passed
+ * the minimum number of friends.
+ */
+static void
+whitelist_peers ()
+{
+ struct PeerList *pl;
+ struct DisconnectList *dl;
+
+ /* first, cancel all blacklisting requests */
+ while (NULL != (dl = disconnect_head))
+ {
+ GNUNET_CONTAINER_DLL_remove (disconnect_head,
+ disconnect_tail,
+ dl);
+ GNUNET_TRANSPORT_blacklist_cancel (dl->rh);
+ GNUNET_free (dl);
+ }
+ /* then, specifically whitelist all peers that we
+ know to have blacklisted */
+ pl = peers;
+ while (pl != NULL)
+ {
+ if (pl->is_blocked)
+ {
+ pl->wh = GNUNET_TRANSPORT_blacklist (sched, cfg,
+ &pl->id,
+ GNUNET_TIME_UNIT_ZERO,
+ GNUNET_TIME_UNIT_FOREVER_REL,
+ &whitelist_done,
+ pl);
+ pl->is_blocked = GNUNET_NO;
+ }
+ pl = pl->next;
+ }
+}
+
+
+/**
+ * Function called by core when our attempt to connect succeeded.
+ */
+static void
+connect_completed_callback (void *cls,
+ const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ struct PeerList *pos = cls;
+
+ pos->connect_req = NULL;
+}
+
+
+/**
+ * Try to connect to the specified peer.
+ *
+ * @param pos peer to connect to
+ */
+static void
+attempt_connect (struct PeerList *pos)
+{
+ if (GNUNET_YES == pos->is_friend)
+ pos->blacklisted_until = GNUNET_TIME_relative_to_absolute (BLACKLIST_AFTER_ATTEMPT_FRIEND);
+ else
+ pos->blacklisted_until = GNUNET_TIME_relative_to_absolute (BLACKLIST_AFTER_ATTEMPT);
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Asking core to connect to `%s'\n",
+ GNUNET_i2s (&pos->id));
+#endif
+ pos->connect_req = GNUNET_CORE_peer_request_connect (sched, cfg,
+ GNUNET_TIME_UNIT_MINUTES,
+ &pos->id,
+ &connect_completed_callback,
+ pos);
+}
+
+
+/**
+ * Find a peer in our linked list.
+ * FIXME: should probably use a hash map instead.
+ */
+struct PeerList *
+find_peer (const struct GNUNET_PeerIdentity * peer)
+{
+ struct PeerList *pos;
+
+ pos = peers;
+ while (pos != NULL)
+ {
+ if (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity)))
+ return pos;
+ pos = pos->next;
+ }
+ return NULL;
+}
+
+
+/**
+ * Check if an additional connection from the given peer is allowed.
+ */
+static int
+is_connection_allowed (struct PeerList *peer)
+{
+ if (0 == memcmp (&my_identity, &peer->id, 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->id));
+#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->id));
+#endif
+ return GNUNET_SYSERR;
+}
+
+
+/**
+ * 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 PeerList *
+make_peer (const struct
+ GNUNET_PeerIdentity * peer,
+ const struct GNUNET_HELLO_Message *hello,
+ int is_friend)
+{
+ struct PeerList *ret;
+
+ ret = GNUNET_malloc (sizeof (struct PeerList));
+ ret->id = *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));
+ }
+ ret->next = peers;
+ peers = ret;
+ return ret;
+}
+
+
+/**
+ * Free all resources associated with the given peer.
+ *
+ * @param peer peer to free
+ */
+static void
+free_peer (struct PeerList *peer)
+{
+ struct PeerList *pos;
+ struct PeerList *prev;
+
+ prev = NULL;
+ pos = peers;
+ while (peer != pos)
+ {
+ prev = pos;
+ pos = pos->next;
+ }
+ GNUNET_assert (pos != NULL);
+ if (prev == NULL)
+ peers = pos->next;
+ else
+ prev->next = pos->next;
+ if (pos->hello_req != NULL)
+ GNUNET_CORE_notify_transmit_ready_cancel (pos->hello_req);
+ if (pos->wh != NULL)
+ GNUNET_TRANSPORT_blacklist_cancel (pos->wh);
+ if (pos->connect_req != NULL)
+ GNUNET_CORE_peer_request_connect_cancel (pos->connect_req);
+ if (pos->hello_delay_task != GNUNET_SCHEDULER_NO_TASK)
+ GNUNET_SCHEDULER_cancel (sched,
+ pos->hello_delay_task);
+ GNUNET_free_non_null (pos->hello);
+ if (pos->filter != NULL)
+ GNUNET_CONTAINER_bloomfilter_free (peer->filter);
+ GNUNET_free (pos);
+}
+
+
+/**
+ * Setup bloom filter for the given peer entry.
+ *
+ * @param peer entry to initialize
+ */
+static void
+setup_filter (struct PeerList *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_load (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->id.hashPubKey);
+}
+
+
+/**
+ * Function to fill send buffer with HELLO.
+ *
+ * @param cls 'struct PeerList' 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);
+
+
+/**
+ * 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 PeerList *pl = cls;
+ struct PeerList *pos;
+ struct PeerList *next;
+ uint16_t next_want;
+ struct GNUNET_TIME_Relative next_adv;
+ struct GNUNET_TIME_Relative rst_time;
+
+ pl->hello_delay_task = GNUNET_SCHEDULER_NO_TASK;
+ if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
+ return; /* we're out of here */
+ next_want = 0;
+ next_adv = GNUNET_TIME_UNIT_FOREVER_REL;
+ /* find applicable HELLOs */
+ next = peers;
+ while (NULL != (pos = next))
+ {
+ next = pos->next;
+ if (pos->hello == NULL)
+ continue;
+ rst_time = GNUNET_TIME_absolute_get_remaining (pos->filter_expiration);
+ if (0 == rst_time.value)
+ {
+ /* time to discard... */
+ GNUNET_CONTAINER_bloomfilter_free (pos->filter);
+ setup_filter (pos);
+ }
+ else
+ {
+ if (rst_time.value < next_adv.value)
+ next_want = GNUNET_HELLO_size (pos->hello);
+ next_adv = GNUNET_TIME_relative_min (rst_time,
+ next_adv);
+ }
+ if (GNUNET_NO ==
+ GNUNET_CONTAINER_bloomfilter_test (pos->filter,
+ &pl->id.hashPubKey))
+ break;
+ }
+ if (pos != NULL)
+ next_adv = GNUNET_TIME_absolute_get_remaining (pl->next_hello_allowed);
+ if (next_adv.value == 0)
+ {
+ /* now! */
+ pl->hello_req = GNUNET_CORE_notify_transmit_ready (handle, 0,
+ next_adv,
+ &pl->id,
+ next_want,
+ &hello_advertising_ready,
+ pl);
+ return;
+ }
+ pl->hello_delay_task
+ = GNUNET_SCHEDULER_add_delayed (sched,
+ next_adv,
+ &schedule_next_hello,
+ 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!).
+ */
+static void
+reschedule_hellos (struct PeerList *peer)
+{
+ 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 (sched,
+ peer->hello_delay_task);
+ peer->hello_delay_task = GNUNET_SCHEDULER_NO_TASK;
+ }
+ peer->hello_delay_task
+ = GNUNET_SCHEDULER_add_now (sched,
+ &schedule_next_hello,
+ peer);
+}
+
+
+/**
+ * Method called whenever a peer connects.
+ *
+ * @param cls closure
+ * @param peer peer identity this notification is about
+ * @param latency reported latency of the connection with 'other'
+ * @param distance reported distance (DV) to 'other'
+ */
+static void
+connect_notify (void *cls,
+ const struct
+ GNUNET_PeerIdentity * peer,
+ struct GNUNET_TIME_Relative latency,
+ uint32_t distance)
+{
+ struct PeerList *pos;
+
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Core told us that we are connecting to `%s'\n",
+ GNUNET_i2s (peer));
+#endif
+ connection_count++;
+ pos = find_peer (peer);
+ if (pos == NULL)
+ {
+ pos = make_peer (peer, NULL, GNUNET_NO);
+ if (GNUNET_OK != is_connection_allowed (pos))
+ {
+ GNUNET_assert (pos->is_friend == GNUNET_NO);
+ pos->is_connected = GNUNET_YES;
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Connection to `%s' is forbidden, forcing disconnect!\n",
+ GNUNET_i2s (peer));
+#endif
+ force_disconnect (pos);
+ return;
+ }
+ }
+ else
+ {
+ GNUNET_assert (GNUNET_NO == pos->is_connected);
+ pos->blacklisted_until.value = 0; /* remove blacklisting */
+ }
+ pos->is_connected = GNUNET_YES;
+ if (pos->is_friend)
+ {
+ if ( (friend_count == minimum_friend_count - 1) &&
+ (GNUNET_YES != friends_only) )
+ whitelist_peers ();
+ friend_count++;
+ }
+ reschedule_hellos (pos);
+}
+
+
+/**
+ * Disconnect from all non-friends (we're below quota).
+ */
+static void
+drop_non_friends ()
+{
+ struct PeerList *pos;
+
+ pos = peers;
+ while (pos != NULL)
+ {
+ if ( (GNUNET_NO == pos->is_friend) &&
+ (GNUNET_YES == pos->is_connected) )
+ {
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Connection to `%s' is not from a friend, forcing disconnect!\n",
+ GNUNET_i2s (&pos->id));
+#endif
+ force_disconnect (pos);
+ }
+ pos = pos->next;
+ }
+}
+
+
+/**
+ * Try to add more peers to our connection set.
+ */
+static void
+try_add_peers ()
+{
+ struct PeerList *pos;
+
+ pos = peers;
+ while (pos != NULL)
+ {
+ if ( (GNUNET_TIME_absolute_get_remaining (pos->blacklisted_until).value == 0) &&
+ ( (GNUNET_YES == pos->is_friend) ||
+ (friend_count >= minimum_friend_count) ) &&
+ (GNUNET_YES != pos->is_connected) )
+ attempt_connect (pos);
+ pos = pos->next;
+ }
+}
+
+
+/**
+ * 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 PeerList *pos;
+
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Core told us that we disconnected from `%s'\n",
+ GNUNET_i2s (peer));
+#endif
+ pos = find_peer (peer);
+ if (pos == NULL)
+ {
+ GNUNET_break (0);
+ return;
+ }
+ if (pos->is_connected != GNUNET_YES)
+ {
+ GNUNET_break (0);
+ return;
+ }
+ connection_count--;
+ if (pos->is_friend)
+ friend_count--;
+ if ( (connection_count < target_connection_count) ||
+ (friend_count < minimum_friend_count) )
+ try_add_peers ();
+ if (friend_count < minimum_friend_count)
+ {
+ /* disconnect from all non-friends */
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Not enough friendly connections, dropping all non-friend connections\n");
+#endif
+ drop_non_friends ();
+ }
+}
+
+
+/**
+ * Iterator called on each address.
+ *
+ * @param cls flag that we will set if we see any addresses
+ * @param tname name of the transport
+ * @param expiration when will the given address expire
+ * @param addr the address of the peer
+ * @param addrlen number of bytes in addr
+ * @return GNUNET_SYSERR always, to terminate iteration
+ */
+static int
+address_iterator (void *cls,
+ const char *tname,
+ struct GNUNET_TIME_Absolute expiration,
+ const void *addr, size_t addrlen)
+{
+ int *flag = cls;
+ *flag = GNUNET_YES;
+ return GNUNET_SYSERR;
+}
+
+
+/**
+ * We've gotten a HELLO from another peer. Consider it for
+ * advertising.
+ */
+static void
+consider_for_advertising (const struct GNUNET_HELLO_Message *hello)
+{
+ int have_address;
+ struct GNUNET_PeerIdentity pid;
+ struct PeerList *peer;
+ struct PeerList *pos;
+ uint16_t size;
+
+ 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... */
+ GNUNET_break (GNUNET_OK == GNUNET_HELLO_get_id (hello, &pid));
+ peer = find_peer (&pid);
+ if (peer == NULL)
+ peer = make_peer (&pid, hello, GNUNET_NO);
+ // FIXME: check if 'hello' is any different from peer->hello?
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Found `%s' from peer `%s' for advertising\n",
+ "HELLO",
+ GNUNET_i2s (&pid));
+#endif
+ size = GNUNET_HELLO_size (hello);
+ GNUNET_free_non_null (peer->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! */
+ pos = peers;
+ while (NULL != pos)
+ {
+ if (pos != peer)
+ {
+ if ( (pos->is_connected) &&
+ (GNUNET_TIME_absolute_get_remaining (pos->next_hello_allowed).value <= HELLO_ADVERTISEMENT_MIN_FREQUENCY.value) )
+ reschedule_hellos (pos);
+ }
+ pos = pos->next;
+ }
+}
+
+
+/**
+ * Peerinfo calls this function to let us know about a possible peer
+ * that we might want to connect to.
+ */
+static void
+process_peer (void *cls,
+ const struct GNUNET_PeerIdentity *peer,
+ const struct GNUNET_HELLO_Message *hello,
+ uint32_t trust)
+{
+ struct PeerList *pos;
+
+ 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 */
+ if (NULL != (pos = find_peer (peer)))
+ {
+ 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->blacklisted_until).value) )
+ free_peer (pos);
+ }
+ return;
+ }
+ consider_for_advertising (hello);
+ pos = find_peer (peer);
+ GNUNET_assert (NULL != pos);
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Considering connecting to peer `%s'\n",
+ GNUNET_i2s (peer));
+#endif
+ 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->blacklisted_until).value > 0)
+ {
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Already tried peer `%s' recently\n",
+ GNUNET_i2s (peer));
+#endif
+ return; /* peer still blacklisted */
+ }
+ if ( (GNUNET_YES == pos->is_friend) ||
+ (GNUNET_YES != friends_only) ||
+ (friend_count >= minimum_friend_count) )
+ attempt_connect (pos);
+}
+
+
+/**
+ * Discard peer entries for blacklisted peers
+ * where the blacklisting has expired.
+ */
+static void
+discard_old_blacklist_entries (void *cls,
+ const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ struct PeerList *pos;
+ struct PeerList *next;
+
+ if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
+ return;
+ next = peers;
+ while (NULL != (pos = next))
+ {
+ next = pos->next;
+ if ( (GNUNET_NO == pos->is_friend) &&
+ (GNUNET_NO == pos->is_connected) &&
+ (GNUNET_NO == pos->is_blocked) &&
+ (0 == GNUNET_TIME_absolute_get_remaining (pos->blacklisted_until).value) )
+ free_peer (pos);
+ }
+ GNUNET_SCHEDULER_add_delayed (sched,
+ BLACKLIST_AFTER_ATTEMPT,
+ &discard_old_blacklist_entries,
+ NULL);
+}
+
+
+/**
+ * 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
+ * @param publicKey public key of this peer, NULL if we failed
+ */
+static void
+core_init (void *cls,
+ struct GNUNET_CORE_Handle * server,
+ const struct GNUNET_PeerIdentity *
+ my_id,
+ const struct
+ GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *
+ publicKey)
+{
+ if (server == NULL)
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ _("Failed to connect to core service, can not manage topology!\n"));
+ GNUNET_SCHEDULER_shutdown (sched);
+ 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
+ GNUNET_SCHEDULER_add_delayed (sched,
+ BLACKLIST_AFTER_ATTEMPT,
+ &discard_old_blacklist_entries,
+ 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 PeerList *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 (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 (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 (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 (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
+ {
+ entries_found++;
+ fl = make_peer (&pid,
+ NULL,
+ GNUNET_YES);
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ _("Found friend `%s' in configuration\n"),
+ GNUNET_i2s (&fl->id));
+ }
+ pos = pos + sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded);
+ while ((pos < frstat.st_size) && isspace (data[pos]))
+ pos++;
+ }
+ GNUNET_free (data);
+ GNUNET_free (fn);
+ 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 latency reported latency of the connection with 'other'
+ * @param distance reported distance (DV) to 'other'
+ * @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 GNUNET_TIME_Relative latency,
+ uint32_t distance)
+{
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Received encrypted `%s' from peer `%s'",
+ "HELLO",
+ GNUNET_i2s (other));
+#endif
+ if (transport != NULL)
+ GNUNET_TRANSPORT_offer_hello (transport,
+ message);
+ return GNUNET_OK;
+}
+
+
+/**
+ * Function to fill send buffer with HELLO.
+ *
+ * @param cls 'struct PeerList' 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 PeerList *pl = cls;
+ struct PeerList *pos;
+ struct PeerList *next;
+ uint16_t want;
+ size_t hs;
+
+ pl->hello_req = NULL;
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Data solicited for `%s', considering sending `%s'",
+ GNUNET_i2s (&pl->id),
+ "HELLO");
+#endif
+ /* find applicable HELLOs */
+ next = peers;
+ while (NULL != (pos = next))
+ {
+ next = pos->next;
+ if (pos->hello == NULL)
+ continue;
+ if (0 == GNUNET_TIME_absolute_get_remaining (pos->filter_expiration).value)
+ {
+ /* time to discard... */
+ GNUNET_CONTAINER_bloomfilter_free (pos->filter);
+ setup_filter (pos);
+ }
+ if (GNUNET_NO ==
+ GNUNET_CONTAINER_bloomfilter_test (pos->filter,
+ &pl->id.hashPubKey))
+ break;
+ }
+ want = 0;
+ if (pos != NULL)
+ {
+ hs = GNUNET_HELLO_size (pos->hello);
+ if (hs < size)
+ {
+ want = hs;
+ memcpy (buf, pos->hello, want);
+ GNUNET_CONTAINER_bloomfilter_add (pos->filter,
+ &pl->id.hashPubKey);
+ pl->next_hello_allowed = GNUNET_TIME_relative_to_absolute (HELLO_ADVERTISEMENT_MIN_FREQUENCY);
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Sending %u bytes of `%s's",
+ (unsigned int) want,
+ "HELLO");
+#endif
+ }
+ }
+ pl->hello_delay_task
+ = GNUNET_SCHEDULER_add_now (sched,
+ &schedule_next_hello,
+ pl);
+ return want;
+}
+
+
+/**
+ * Last task run during shutdown. Disconnects us from
+ * the transport and core.
+ */
+static void
+cleaning_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ struct DisconnectList *dl;
+
+ if (NULL != peerinfo_notify)
+ {
+ GNUNET_PEERINFO_notify_cancel (peerinfo_notify);
+ peerinfo_notify = NULL;
+ }
+ GNUNET_TRANSPORT_disconnect (transport);
+ transport = NULL;
+ while (NULL != peers)
+ free_peer (peers);
+ if (handle != NULL)
+ {
+ GNUNET_CORE_disconnect (handle);
+ handle = NULL;
+ }
+ while (NULL != (dl = disconnect_head))
+ {
+ GNUNET_CONTAINER_DLL_remove (disconnect_head,
+ disconnect_tail,
+ dl);
+ GNUNET_TRANSPORT_blacklist_cancel (dl->rh);
+ GNUNET_free (dl);
+ }
+}
+
/**
* Main function that will be run.
*
* @param cls closure
- * @param sched the scheduler to use
+ * @param s the scheduler to use
* @param args remaining command-line arguments
* @param cfgfile name of the configuration file used (for saving, can be NULL!)
- * @param cfg configuration
+ * @param c configuration
*/
-static void
+static void
run (void *cls,
- struct GNUNET_SCHEDULER_Handle * sched,
+ struct GNUNET_SCHEDULER_Handle * s,
char *const *args,
const char *cfgfile,
- struct GNUNET_CONFIGURATION_Handle * cfg)
+ const struct GNUNET_CONFIGURATION_Handle * c)
{
+ struct GNUNET_CORE_MessageHandler handlers[] =
+ {
+ { &handle_encrypted_hello, GNUNET_MESSAGE_TYPE_HELLO, 0},
+ { NULL, 0, 0 }
+ };
+ unsigned long long opt;
+
+ sched = s;
+ cfg = c;
+ 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;
+
+ 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
+ transport = GNUNET_TRANSPORT_connect (sched,
+ cfg,
+ NULL,
+ NULL,
+ NULL,
+ NULL);
+ handle = GNUNET_CORE_connect (sched,
+ cfg,
+ GNUNET_TIME_UNIT_FOREVER_REL,
+ NULL,
+ &core_init,
+ NULL,
+ &connect_notify,
+ &disconnect_notify,
+ NULL, GNUNET_NO,
+ NULL, GNUNET_NO,
+ handlers);
+ GNUNET_SCHEDULER_add_delayed (sched,
+ 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 (sched);
+ return;
+ }
+ if (NULL == handle)
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ _("Failed to connect to `%s' service.\n"),
+ "core");
+ GNUNET_SCHEDULER_shutdown (sched);
+ return;
+ }
+ peerinfo_notify = GNUNET_PEERINFO_notify (cfg, sched,
+ &process_peer,
+ NULL);
}
+/**
+ * gnunet-daemon-topology command line options.
+ */
+static struct GNUNET_GETOPT_CommandLineOption options[] = {
+ GNUNET_GETOPT_OPTION_END
+};
+
+
/**
* The main function for the topology daemon.
*
ret = (GNUNET_OK ==
GNUNET_PROGRAM_run (argc,
argv,
- "topology",
+ "topology",
_("GNUnet topology control (maintaining P2P mesh and F2F constraints)"),
options,
&run, NULL)) ? 0 : 1;
projects / oweals / gnunet.git / blobdiff