* @file topology/gnunet-daemon-topology.c
* @brief code for maintaining the mesh topology
* @author Christian Grothoff
+ *
+ * TODO:
+ * - make sure that PEERINFO *also* notifies us when a HELLO expires
+ * (otherwise the 'soft state' of this module does not work nicely)
+ * - CORE API's connect/disconnect API is not nice (we think we are
+ * connected when we are not; disconnect using bandwidth-limiting
+ * does not really work and is not nice)
+ * OPTIMIZATIONS:
+ * - move code to use hash table instead of linked list
+ * - instead of periodically discarding blacklisted entries,
+ * simply add task that is triggered at the right time (earlier free,
+ * more balanced load)
+ * - check if new HELLO learned is different from old HELLO
+ * before resetting entire state!
*/
#include <stdlib.h>
#define DEBUG_TOPOLOGY GNUNET_NO
/**
- * For how long do we blacklist a peer after a failed
- * connection attempt?
+ * For how long do we blacklist a peer after a failed connection
+ * attempt?
*/
#define BLACKLIST_AFTER_ATTEMPT GNUNET_TIME_UNIT_HOURS
/**
- * For how long do we blacklist a friend after a failed
- * connection attempt?
+ * 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 frequently are we allowed to ask PEERINFO for more
- * HELLO's to advertise (at most)?
+ * How often do we at most advertise any HELLO to a peer?
*/
-#define MIN_HELLO_GATHER_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 27)
+#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?
- * Also used to remove HELLOs of peers that PEERINFO no longer lists
- * from our cache.
*/
-#define HELLO_ADVERTISEMENT_MIN_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 12)
+#define HELLO_ADVERTISEMENT_MIN_REPEAT_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 4)
/**
struct PeerList *next;
/**
- * Is this peer listed here because he is a friend?
+ * Our handle for the request to transmit HELLOs to this peer; NULL
+ * if no such request is pending.
*/
- int is_friend;
+ struct GNUNET_CORE_TransmitHandle *hello_req;
/**
- * Are we connected to this peer right now?
+ * Our handle for the request to connect to this peer; NULL if no
+ * such request is pending.
*/
- int is_connected;
+ struct GNUNET_CORE_TransmitHandle *connect_req;
/**
- * Until what time should we not try to connect again
- * to this peer?
+ * Pointer to the HELLO message of this peer; can be NULL.
*/
- struct GNUNET_TIME_Absolute blacklisted_until;
+ struct GNUNET_HELLO_Message *hello;
/**
- * Last time we transmitted a HELLO to this peer?
+ * Bloom filter used to mark which peers already got the HELLO
+ * from this peer.
*/
- struct GNUNET_TIME_Absolute last_hello_sent;
+ struct GNUNET_CONTAINER_BloomFilter *filter;
/**
- * ID of the peer.
+ * Is this peer listed here because he is a friend?
*/
- struct GNUNET_PeerIdentity id;
-
-};
+ int is_friend;
+ /**
+ * Are we connected to this peer right now?
+ */
+ int is_connected;
-/**
- * List of HELLOs we may consider for advertising.
- */
-struct HelloList
-{
/**
- * This is a linked list.
+ * Until what time should we not try to connect again
+ * to this peer?
*/
- struct HelloList *next;
+ struct GNUNET_TIME_Absolute blacklisted_until;
/**
- * Pointer to the HELLO message. Memory allocated as part
- * of the "struct HelloList" --- do not free!
+ * Next time we are allowed to transmit a HELLO to this peer?
*/
- struct GNUNET_HELLO_Message *msg;
+ struct GNUNET_TIME_Absolute next_hello_allowed;
/**
- * Bloom filter used to mark which peers already got
- * this HELLO.
+ * When should we reset the bloom filter of this entry?
*/
- struct GNUNET_CONTAINER_BloomFilter *filter;
+ struct GNUNET_TIME_Absolute filter_expiration;
/**
- * What peer is this HELLO for?
+ * ID of task we use to wait for the time to send the next HELLO
+ * to this peer.
*/
- struct GNUNET_PeerIdentity id;
+ GNUNET_SCHEDULER_TaskIdentifier hello_delay_task;
/**
- * When should we remove this entry from the linked list (either
- * resetting the filter or possibly eliminating it for good because
- * we no longer consider the peer to be participating in the
- * network)?
+ * ID of the peer.
*/
- struct GNUNET_TIME_Absolute expiration;
+ struct GNUNET_PeerIdentity id;
+
};
};
-
/**
* Our peerinfo notification context. We use notification
- * to instantly learn about new peers as they are discovered
- * as well as periodic iteration to try peers again after
- * a while.
+ * to instantly learn about new peers as they are discovered.
*/
static struct GNUNET_PEERINFO_NotifyContext *peerinfo_notify;
-/**
- * Linked list of HELLOs for advertising.
- */
-static struct HelloList *hellos;
-
/**
* Our scheduler.
*/
-static struct GNUNET_SCHEDULER_Handle * sched;
+static struct GNUNET_SCHEDULER_Handle *sched;
/**
* Our configuration.
*/
-static const struct GNUNET_CONFIGURATION_Handle * cfg;
+static const struct GNUNET_CONFIGURATION_Handle *cfg;
/**
* Handle to the core API.
static struct GNUNET_PeerIdentity my_identity;
/**
- * Linked list of all of our friends and all of our current
- * neighbours.
- */
-static struct PeerList *friends;
-
-/**
- * Timestamp from the last time we tried to gather HELLOs.
+ * 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 GNUNET_TIME_Absolute last_hello_gather_time;
+static struct PeerList *peers;
/**
* Flag to disallow non-friend connections (pure F2F mode).
*/
static int autoconnect;
-/**
- * Non-NULL if we are currently having a request pending with
- * PEERINFO asking for HELLOs for advertising?
- */
-static struct GNUNET_PEERINFO_IteratorContext *pitr;
-
-/**
- * Non-NULL if we are currently having a request pending with
- * PEERINFO looking for more peers to connect to.
- */
-static struct GNUNET_PEERINFO_IteratorContext *pitr_more;
-
/**
* Head of doubly-linked list of active 'disconnect' requests that we have issued.
*/
/**
- * Force a disconnect from the specified peer.
+ * Force a disconnect from the specified peer. This is currently done by
+ * changing the bandwidth policy to 0 bytes per second.
+ * FIXME: maybe we want a nicer CORE API for both connect and disconnect...
+ * FIXME: this policy change is never undone; how do we reconnect ever?
*/
static void
force_disconnect (const struct GNUNET_PeerIdentity *peer)
/**
- * Function called by core when our attempt to connect
- * succeeded. Does nothing.
+ * Function called by core when our attempt to connect succeeded.
+ * Transmits a 'DUMMY' message to trigger the session key exchange.
+ * FIXME: this is an issue with the current CORE API.
*/
static size_t
ready_callback (void *cls,
size_t size, void *buf)
{
+ struct PeerList *pos = cls;
struct GNUNET_MessageHeader hdr;
+
+ pos->connect_req = NULL;
if (buf == NULL)
{
#if DEBUG_TOPOLOGY
* @param pos entry in our friend list; NULL if not in friend list yet
*/
static void
-attempt_connect (const struct GNUNET_PeerIdentity *peer,
- struct PeerList *pos)
+attempt_connect (struct PeerList *pos)
{
- if (pos == NULL)
- {
- pos = friends;
- while (pos != NULL)
- {
- if (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity)))
- break;
- pos = pos->next;
- }
- }
- if (pos == NULL)
- {
- pos = GNUNET_malloc (sizeof(struct PeerList));
- pos->id = *peer;
- pos->next = friends;
- friends = pos;
- }
if (GNUNET_YES == pos->is_friend)
pos->blacklisted_until = GNUNET_TIME_relative_to_absolute (BLACKLIST_AFTER_ATTEMPT_FRIEND);
else
#if DEBUG_TOPOLOGY
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Asking core to connect to `%s'\n",
- GNUNET_i2s (peer));
+ GNUNET_i2s (&pos->id));
#endif
- GNUNET_CORE_notify_transmit_ready (handle,
- 0 /* priority */,
- GNUNET_TIME_UNIT_MINUTES,
- peer,
- sizeof(struct GNUNET_MessageHeader),
- &ready_callback,
- NULL);
+ pos->connect_req = GNUNET_CORE_notify_transmit_ready (handle,
+ 0 /* priority */,
+ GNUNET_TIME_UNIT_MINUTES,
+ &pos->id,
+ sizeof(struct GNUNET_MessageHeader),
+ &ready_callback,
+ pos);
}
/**
- * Is this peer one of our friends?
+ * Find a peer in our linked list.
+ * FIXME: should probably use a hash map instead.
*/
-static int
-is_friend (const struct GNUNET_PeerIdentity * peer)
+struct PeerList *
+find_peer (const struct GNUNET_PeerIdentity * peer)
{
struct PeerList *pos;
- pos = friends;
+ pos = peers;
while (pos != NULL)
{
- if ( (GNUNET_YES == pos->is_friend) &&
- (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity))) )
- {
-#if DEBUG_TOPOLOGY
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Determined that `%s' is a friend\n",
- GNUNET_i2s (peer));
-#endif
- return GNUNET_YES;
- }
+ if (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity)))
+ return pos;
pos = pos->next;
}
- return GNUNET_NO;
+ return NULL;
}
* Check if an additional connection from the given peer is allowed.
*/
static int
-is_connection_allowed (const struct GNUNET_PeerIdentity * peer)
+is_connection_allowed (struct PeerList *peer)
{
- if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
+ if (0 == memcmp (&my_identity, &peer->id, sizeof (struct GNUNET_PeerIdentity)))
return GNUNET_SYSERR; /* disallow connections to self */
- if (is_friend (peer))
+ 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));
+ GNUNET_i2s (&peer->id));
#endif
return GNUNET_SYSERR;
}
#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));
+ 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;
+ struct PeerList *next;
+
+ prev = NULL;
+ next = peers;
+ while (peer != (pos = next))
+ {
+ next = pos->next;
+ prev = pos;
+ }
+ GNUNET_assert (pos != NULL);
+ if (prev == NULL)
+ peers = next;
+ else
+ prev->next = next;
+ if (pos->hello_req != NULL)
+ GNUNET_CORE_notify_transmit_ready_cancel (pos->hello_req);
+ if (pos->connect_req != NULL)
+ GNUNET_CORE_notify_transmit_ready_cancel (pos->connect_req);
+ if (pos->hello_delay_task != GNUNET_SCHEDULER_NO_TASK)
+ GNUNET_SCHEDULER_cancel (sched,
+ pos->hello_delay_task);
+ 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
*/
-static void connect_notify (void *cls,
- const struct
- GNUNET_PeerIdentity * peer)
+static void
+connect_notify (void *cls,
+ const struct
+ GNUNET_PeerIdentity * peer)
{
struct PeerList *pos;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Core told us that we are connecting to `%s'\n",
GNUNET_i2s (peer));
-#endif
+#endif
connection_count++;
- pos = friends;
- while (pos != NULL)
+ pos = find_peer (peer);
+ if (pos == NULL)
{
- if ( (GNUNET_YES == pos->is_friend) &&
- (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity))) )
+ pos = make_peer (peer, NULL, GNUNET_NO);
+ if (GNUNET_OK != is_connection_allowed (pos))
{
- GNUNET_assert (GNUNET_NO == pos->is_connected);
+ GNUNET_assert (pos->is_friend == GNUNET_NO);
pos->is_connected = GNUNET_YES;
- pos->blacklisted_until.value = 0; /* remove blacklisting */
- friend_count++;
+#if DEBUG_TOPOLOGY
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Connection to `%s' is forbidden, forcing disconnect!\n",
+ GNUNET_i2s (peer));
+#endif
+ force_disconnect (&pos->id);
return;
}
- pos = pos->next;
}
- pos = GNUNET_malloc (sizeof(struct PeerList));
- pos->id = *peer;
- pos->is_connected = GNUNET_YES;
- pos->next = friends;
- friends = pos;
- if (GNUNET_OK != is_connection_allowed (peer))
+ else
{
-#if DEBUG_TOPOLOGY
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Connection to `%s' is forbidden, forcing disconnect!\n",
- GNUNET_i2s (peer));
-#endif
- force_disconnect (peer);
+ GNUNET_assert (GNUNET_NO == pos->is_connected);
+ pos->blacklisted_until.value = 0; /* remove blacklisting */
}
+ pos->is_connected = GNUNET_YES;
+ if (pos->is_friend)
+ friend_count++;
+ reschedule_hellos (pos);
}
{
struct PeerList *pos;
- pos = friends;
+ pos = peers;
while (pos != NULL)
{
- if (GNUNET_NO == pos->is_friend)
+ if ( (GNUNET_NO == pos->is_friend) &&
+ (GNUNET_YES == pos->is_connected) )
{
- GNUNET_assert (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",
}
+/**
+ * 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)
+static void
+disconnect_notify (void *cls,
+ const struct
+ GNUNET_PeerIdentity * peer)
{
struct PeerList *pos;
- struct PeerList *prev;
#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--;
- pos = friends;
- prev = NULL;
- while (pos != NULL)
+ 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)
{
- if (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity)))
- {
- GNUNET_assert (GNUNET_YES == pos->is_connected);
- pos->is_connected = GNUNET_NO;
- if (GNUNET_YES == pos->is_friend)
- {
- friend_count--;
- if (friend_count < minimum_friend_count)
- {
- /* disconnect from all non-friends */
+ /* disconnect from all non-friends */
#if DEBUG_TOPOLOGY
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Not enough friendly connections, dropping all non-friend connections\n");
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Not enough friendly connections, dropping all non-friend connections\n");
#endif
- drop_non_friends ();
- attempt_connect (peer, pos);
- }
- }
- else
- {
- /* free entry */
- if (prev == NULL)
- friends = pos->next;
- else
- prev->next = pos->next;
- GNUNET_free (pos);
- }
- return;
- }
- prev = pos;
- pos = pos->next;
+ drop_non_friends ();
}
- GNUNET_break (0);
-}
-
-
-/**
- * Find more peers that we should connect to and ask the
- * core to establish connections.
- */
-static void
-find_more_peers (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc);
-
-
-/**
- * Determine when we should try again to find more peers and
- * schedule the task.
- */
-static void
-schedule_peer_search ()
-{
- struct GNUNET_TIME_Relative delay;
-
- /* Typically, we try again every 15 minutes; the minimum period is
- 15s; if we are above the connection target, we reduce re-trying
- by the square of how much we are above; so for example, with 200%
- of the connection target we would only look for more peers once
- every hour (after all, we're quite busy processing twice as many
- connections as we intended to have); similarly, if we are at only
- 25% of our connectivity goal, we will try 16x as hard to connect
- (so roughly once a minute, plus the 15s minimum delay */
- delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
- 15 + 15 * 60 * connection_count * connection_count / target_connection_count / target_connection_count);
-#if DEBUG_TOPOLOGY
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Will try to find more peers in %llums\n",
- (unsigned long long) delay.value);
-#endif
- GNUNET_SCHEDULER_add_delayed (sched,
- delay,
- &find_more_peers,
- NULL);
}
-
-
/**
* Iterator called on each address.
*
/**
- * We've gotten a HELLO from another peer.
- * Consider it for advertising.
+ * 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 HelloList *pos;
+ struct PeerList *peer;
+ struct PeerList *pos;
uint16_t size;
have_address = GNUNET_NO;
if (GNUNET_NO == have_address)
return; /* no point in advertising this one... */
GNUNET_break (GNUNET_OK == GNUNET_HELLO_get_id (hello, &pid));
- pos = hellos;
- while (pos != NULL)
- {
- if (0 == memcmp (&pos->id,
- &pid,
- sizeof(struct GNUNET_PeerIdentity)))
- return; /* duplicate, at least "mostly" */
- pos = pos->next;
- }
+ peer = find_peer (&pid);
+ if (peer == NULL)
+ peer = make_peer (&pid, hello, GNUNET_NO);
+ // FIXME: check if 'hello' is any different from peer->hello?
+ GNUNET_free_non_null (peer->hello);
#if DEBUG_TOPOLOGY
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Found `%s' from peer `%s' for advertising\n",
GNUNET_i2s (&pid));
#endif
size = GNUNET_HELLO_size (hello);
- pos = GNUNET_malloc (sizeof(struct HelloList) + size);
- pos->msg = (struct GNUNET_HELLO_Message*) &pos[1];
- memcpy (&pos->msg, hello, size);
- pos->id = pid;
- pos->expiration = GNUNET_TIME_relative_to_absolute (HELLO_ADVERTISEMENT_MIN_FREQUENCY);
- /* 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. */
- pos->filter = GNUNET_CONTAINER_bloomfilter_load (NULL, 64, 5);
- /* never send a peer its own HELLO */
- GNUNET_CONTAINER_bloomfilter_add (pos->filter, &pos->id.hashPubKey);
- pos->next = hellos;
- hellos = pos;
+ 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.
+ * 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,
{
struct PeerList *pos;
- if (peer == NULL)
+ GNUNET_assert (peer != NULL);
+ if (0 == memcmp (&my_identity,
+ peer, sizeof (struct GNUNET_PeerIdentity)))
+ return; /* that's me! */
+ if (hello == NULL)
{
- pitr_more = NULL;
- /* last call, schedule 'find_more_peers' again... */
- if (0 != (GNUNET_SCHEDULER_get_reason (sched) & GNUNET_SCHEDULER_REASON_SHUTDOWN))
+ /* free existing HELLO, if any */
+ pos = find_peer (peer);
+ if (NULL != (pos = find_peer (peer)))
{
-#if DEBUG_TOPOLOGY
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Received shutdown request, stopping search for peers to connect to.\n");
-#endif
- return;
+ 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);
}
- schedule_peer_search ();
- return;
- }
- if (hello == NULL)
- {
- /* no HELLO known; can not connect, ignore! */
return;
}
- if (0 == memcmp (&my_identity,
- peer, sizeof (struct GNUNET_PeerIdentity)))
- return; /* that's me! */
-
consider_for_advertising (hello);
+ pos = find_peer (peer);
#if DEBUG_TOPOLOGY
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Considering connecting to peer `%s'\n",
GNUNET_i2s (peer));
#endif
- pos = friends;
- while (pos != NULL)
- {
- if (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity)))
- {
- 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)
- {
- attempt_connect (peer, pos);
- return;
- }
- }
- pos = pos->next;
- }
- if ( (GNUNET_YES == friends_only) ||
- (friend_count < minimum_friend_count) )
+ if (GNUNET_YES == pos->is_connected)
{
#if DEBUG_TOPOLOGY
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Peer `%s' is not a friend, and we currently only connect to friends\n",
+ "Already connected to peer `%s'\n",
GNUNET_i2s (peer));
#endif
return;
}
- attempt_connect (peer, NULL);
-}
-
-
-/**
- * Try to add more friends to our connection set.
- */
-static void
-try_add_friends ()
-{
- struct PeerList *pos;
-
+ if (GNUNET_TIME_absolute_get_remaining (pos->blacklisted_until).value > 0)
+ {
#if DEBUG_TOPOLOGY
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Considering all of our friends for new connections\n");
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Already tried peer `%s' recently\n",
+ GNUNET_i2s (peer));
#endif
- pos = friends;
- while (pos != NULL)
- {
- if ( (GNUNET_TIME_absolute_get_remaining (pos->blacklisted_until).value == 0) &&
- (GNUNET_YES == pos->is_friend) &&
- (GNUNET_YES != pos->is_connected) )
- attempt_connect (&pos->id, pos);
- pos = pos->next;
+ return; /* peer still blacklisted */
}
+ if ( (GNUNET_YES == pos->is_friend) ||
+ (GNUNET_YES != friends_only) ||
+ (friend_count >= minimum_friend_count) )
+ attempt_connect (pos);
}
* where the blacklisting has expired.
*/
static void
-discard_old_blacklist_entries ()
+discard_old_blacklist_entries (void *cls,
+ const struct GNUNET_SCHEDULER_TaskContext *tc)
{
struct PeerList *pos;
struct PeerList *next;
- struct PeerList *prev;
- next = friends;
- prev = NULL;
+ 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) &&
(0 == GNUNET_TIME_absolute_get_remaining (pos->blacklisted_until).value) )
- {
- /* delete 'pos' from list */
-#if DEBUG_TOPOLOGY
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Deleting peer `%s' from our list (not connected, not a friend and blacklist expired)\n",
- GNUNET_i2s (&pos->id));
-#endif
- if (prev == NULL)
- friends = next;
- else
- prev->next = next;
- GNUNET_free (pos);
- }
- else
- {
- prev = pos;
- }
- }
-}
-
-
-/**
- * Find more peers that we should connect to and ask the
- * core to establish connections.
- */
-static void
-find_more_peers (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
- if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
- {
-#if DEBUG_TOPOLOGY
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Received shutdown request, stopping search for peers to connect to.\n");
-#endif
- return;
- }
- discard_old_blacklist_entries ();
- if (connection_count <= target_connection_count)
- {
- schedule_peer_search ();
- return;
+ free_peer (pos);
}
- if ( (GNUNET_YES == friends_only) ||
- (friend_count < minimum_friend_count) )
- {
- try_add_friends ();
- schedule_peer_search ();
- return;
- }
-#if DEBUG_TOPOLOGY
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Got sufficient (%u/%u, %u friends) number of connections, won't try to create more.\n",
- connection_count,
- target_connection_count,
- friend_count);
-#endif
- pitr_more = GNUNET_PEERINFO_iterate (cfg,
- sched,
- NULL,
- 0, GNUNET_TIME_UNIT_FOREVER_REL,
- &process_peer, NULL);
+ GNUNET_SCHEDULER_add_delayed (sched,
+ BLACKLIST_AFTER_ATTEMPT,
+ &discard_old_blacklist_entries,
+ NULL);
}
"I am peer `%s'\n",
GNUNET_i2s (my_id));
#endif
- if (autoconnect)
- GNUNET_SCHEDULER_add_delayed (sched,
- GNUNET_TIME_UNIT_SECONDS /* give core time to tell us about existing connections */,
- &find_more_peers,
- NULL);
+ GNUNET_SCHEDULER_add_delayed (sched,
+ BLACKLIST_AFTER_ATTEMPT,
+ &discard_old_blacklist_entries,
+ NULL);
}
-/**
- * gnunet-daemon-topology command line options.
- */
-static struct GNUNET_GETOPT_CommandLineOption options[] = {
- GNUNET_GETOPT_OPTION_END
-};
-
-
/**
* Read the friends file.
*/
char *fn;
char *data;
size_t pos;
- GNUNET_HashCode hc;
+ struct GNUNET_PeerIdentity pid;
struct stat frstat;
struct GNUNET_CRYPTO_HashAsciiEncoded enc;
unsigned int entries_found;
continue;
}
enc.encoding[sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1] = '\0';
- if (GNUNET_OK != GNUNET_CRYPTO_hash_from_string ((char *) &enc, &hc))
+ 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"),
else
{
entries_found++;
- fl = GNUNET_malloc (sizeof(struct PeerList));
- fl->is_friend = GNUNET_YES;
- fl->id.hashPubKey = hc;
- fl->next = friends;
- friends = fl;
+ fl = make_peer (&pid,
+ NULL,
+ GNUNET_YES);
#if DEBUG_TOPOLOGY
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Found friend `%s' in configuration\n",
}
-/**
- * Peerinfo calls this function to let us know about a
- * possible peer that we might want to connect to.
- *
- * @param cls unused
- * @param peer NULL for the end of the list, otherwise a peer identity
- * @param hello a HELLO for a peer, or NULL
- * @param trust how much do we trust the given peer?
- */
-static void
-gather_hello_callback (void *cls,
- const struct GNUNET_PeerIdentity *peer,
- const struct GNUNET_HELLO_Message *hello,
- uint32_t trust)
-{
- if (peer == NULL)
- {
- pitr = NULL;
- return;
- }
-#if DEBUG_TOPOLOGY
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Received `%s' for peer `%s'",
- "HELLO",
- GNUNET_i2s (peer));
-#endif
- if (hello != NULL)
- consider_for_advertising (hello);
-}
-
-
-// FIXME: this no longer works (no solicitation!)
/**
* Function to fill send buffer with HELLO.
*
- * @param cls unused
- * @param receiver the receiver of the message
- * @param position is the reference to the
- * first unused position in the buffer where GNUnet is building
- * the message
- * @param padding is the number of bytes left in that buffer.
- * @return the number of bytes written to
- * that buffer (must be a positive number).
+ * @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 */ unsigned int
-hello_advertising (void *cls,
- const struct GNUNET_PeerIdentity *
- receiver,
- void *position,
- size_t padding)
+static size_t
+hello_advertising_ready (void *cls,
+ size_t size,
+ void *buf)
{
- struct PeerList *pl;
- struct HelloList *pos;
- struct HelloList *prev;
- struct HelloList *next;
- uint16_t size;
+ 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's",
- GNUNET_i2s (receiver),
+ "Data solicited for `%s', considering sending `%s'",
+ GNUNET_i2s (&pl->id),
"HELLO");
#endif
- pl = friends;
- while (pl != NULL)
- {
- if (0 == memcmp (&pl->id, receiver, sizeof (struct GNUNET_PeerIdentity)))
- break;
- pl = pl->next;
- }
- if (pl == NULL)
- {
- GNUNET_break (0);
- return 0;
- }
/* find applicable HELLOs */
- prev = NULL;
- next = hellos;
+ next = peers;
while (NULL != (pos = next))
{
next = pos->next;
- if (GNUNET_NO ==
- GNUNET_CONTAINER_bloomfilter_test (pos->filter,
- &receiver->hashPubKey))
- break;
- if (0 == GNUNET_TIME_absolute_get_remaining (pos->expiration).value)
+ if (pos->hello == NULL)
+ continue;
+ if (0 == GNUNET_TIME_absolute_get_remaining (pos->filter_expiration).value)
{
/* time to discard... */
- if (prev != NULL)
- prev->next = next;
- else
- hellos = next;
GNUNET_CONTAINER_bloomfilter_free (pos->filter);
- GNUNET_free (pos);
- }
- else
- {
- prev = pos;
+ setup_filter (pos);
}
+ if (GNUNET_NO ==
+ GNUNET_CONTAINER_bloomfilter_test (pos->filter,
+ &pl->id.hashPubKey))
+ break;
}
+ want = 0;
if (pos != NULL)
{
- size = GNUNET_HELLO_size (pos->msg);
- if (size < padding)
+ hs = GNUNET_HELLO_size (pos->hello);
+ if (hs < size)
{
- memcpy (position, pos->msg, size);
+ want = hs;
+ memcpy (buf, pos->hello, want);
GNUNET_CONTAINER_bloomfilter_add (pos->filter,
- &receiver->hashPubKey);
- }
- else
- {
- size = 0;
- }
+ &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) size,
- "HELLO");
-#endif
- return size;
- }
- if ( (NULL == pitr) &&
- (GNUNET_TIME_absolute_get_duration (last_hello_gather_time).value >
- MIN_HELLO_GATHER_DELAY.value) )
- {
-#if DEBUG_TOPOLOGY
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Have no `%s's, trying to get some from `%s' for next time",
- "HELLO",
- "PEERINFO");
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Sending %u bytes of `%s's",
+ (unsigned int) want,
+ "HELLO");
#endif
- last_hello_gather_time = GNUNET_TIME_absolute_get();
- pitr = GNUNET_PEERINFO_iterate (cfg,
- sched,
- NULL,
- 0, GNUNET_TIME_UNIT_FOREVER_REL,
- &gather_hello_callback, NULL);
+ }
}
- return 0;
+ pl->hello_delay_task
+ = GNUNET_SCHEDULER_add_now (sched,
+ &schedule_next_hello,
+ pl);
+ return want;
}
static void
cleaning_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
- struct PeerList *pl;
struct DisconnectList *dl;
if (NULL != peerinfo_notify)
GNUNET_PEERINFO_notify_cancel (peerinfo_notify);
peerinfo_notify = NULL;
}
- if (NULL != pitr)
- {
- GNUNET_PEERINFO_iterate_cancel (pitr);
- pitr = NULL;
- }
- if (NULL != pitr_more)
- {
- GNUNET_PEERINFO_iterate_cancel (pitr_more);
- pitr_more = NULL;
- }
GNUNET_TRANSPORT_disconnect (transport);
transport = NULL;
+ while (NULL != peers)
+ free_peer (peers);
if (handle != NULL)
{
GNUNET_CORE_disconnect (handle);
handle = NULL;
}
- while (NULL != (pl = friends))
- {
- friends = pl->next;
- GNUNET_free (pl);
- }
while (NULL != (dl = disconnect_head))
{
GNUNET_CONTAINER_DLL_remove (disconnect_head,
}
+/**
+ * gnunet-daemon-topology command line options.
+ */
+static struct GNUNET_GETOPT_CommandLineOption options[] = {
+ GNUNET_GETOPT_OPTION_END
+};
+
+
/**
* The main function for the topology daemon.
*
projects / oweals / gnunet.git / commitdiff