/*
This file is part of GNUnet.
Copyright (C) 2007-2016 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
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
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @file topology/gnunet-daemon-topology.c
* @brief code for maintaining the overlay topology
* @author Christian Grothoff
*
* This daemon combines three functions:
* - suggesting to ATS which peers we might want to connect to
* - enforcing the F2F restrictions (by blacklisting)
* - gossping HELLOs
*
* All three require similar information (who are our friends
* impacts connectivity suggestions; connectivity suggestions
* should consider blacklisting; connectivity suggestions
* should consider available/known HELLOs; gossip requires
* connectivity data; connectivity suggestions require
* connectivity data), which is why they are combined in this
* program.
*/
#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"
#include "gnunet_ats_service.h"
/**
* 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 transmitting to this peer; NULL
* if peer is not connected.
*/
struct GNUNET_MQ_Handle *mq;
/**
* 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;
/**
* 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.
*/
struct GNUNET_SCHEDULER_Task *hello_delay_task;
/**
* Handle for our connectivity suggestion for this peer.
*/
struct GNUNET_ATS_ConnectivitySuggestHandle *sh;
/**
* How much would we like to connect to this peer?
*/
uint32_t strength;
/**
* Is this peer listed here because it is a friend?
*/
int is_friend;
};
/**
* 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 service.
*/
static struct GNUNET_CORE_Handle *handle;
/**
* Handle to the PEERINFO service.
*/
static struct GNUNET_PEERINFO_Handle *pi;
/**
* Handle to the ATS service.
*/
static struct GNUNET_ATS_ConnectivityHandle *ats;
/**
* 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;
/**
* Task scheduled to asynchronously reconsider adding/removing
* peer connectivity suggestions.
*/
static struct GNUNET_SCHEDULER_Task *add_task;
/**
* Active HELLO offering to transport service.
*/
static struct GNUNET_TRANSPORT_OfferHelloHandle *oh;
/**
* 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 ((NULL != pos) && (GNUNET_YES == pos->is_friend))
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 (NULL != blacklist)
{
GNUNET_TRANSPORT_blacklist_cancel (blacklist);
blacklist = NULL;
}
}
/**
* 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 (NULL == pos->mq);
GNUNET_break (GNUNET_OK ==
GNUNET_CONTAINER_multipeermap_remove (peers, pid, pos));
if (NULL != pos->hello_delay_task)
{
GNUNET_SCHEDULER_cancel (pos->hello_delay_task);
pos->hello_delay_task = NULL;
}
if (NULL != pos->sh)
{
GNUNET_ATS_connectivity_suggest_cancel (pos->sh);
pos->sh = NULL;
}
if (NULL != pos->hello)
{
GNUNET_free_non_null (pos->hello);
pos->hello = NULL;
}
if (NULL != pos->filter)
{
GNUNET_CONTAINER_bloomfilter_free (pos->filter);
pos->filter = NULL;
}
GNUNET_free (pos);
return GNUNET_YES;
}
/**
* Recalculate how much we want to be connected to the specified peer
* and let ATS know about the result.
*
* @param pos peer to consider connecting to
*/
static void
attempt_connect (struct Peer *pos)
{
uint32_t strength;
if (0 == GNUNET_memcmp (&my_identity, &pos->pid))
return; /* This is myself, nothing to do. */
if (connection_count < target_connection_count)
strength = 1;
else
strength = 0;
if ((friend_count < minimum_friend_count) || (GNUNET_YES == friends_only))
{
if (pos->is_friend)
strength += 10; /* urgently needed */
else
strength = 0; /* disallowed */
}
if (pos->is_friend)
strength *= 2; /* friends always count more */
if (NULL != pos->mq)
strength *= 2; /* existing connections preferred */
if (strength == pos->strength)
return; /* nothing to do */
if (NULL != pos->sh)
{
GNUNET_ATS_connectivity_suggest_cancel (pos->sh);
pos->sh = NULL;
}
pos->strength = strength;
if (0 != strength)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Asking to connect to `%s' with strength %u\n",
GNUNET_i2s (&pos->pid),
(unsigned int) strength);
GNUNET_STATISTICS_update (stats,
gettext_noop ("# connect requests issued to ATS"),
1,
GNUNET_NO);
pos->sh = GNUNET_ATS_connectivity_suggest (ats, &pos->pid, strength);
}
}
/**
* 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;
if (NULL != hello)
{
ret->hello = GNUNET_malloc (GNUNET_HELLO_size (hello));
GNUNET_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);
}
/**
* 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
*/
static void
schedule_next_hello (void *cls)
{
struct Peer *pl = cls;
struct FindAdvHelloContext fah;
struct GNUNET_MQ_Envelope *env;
size_t want;
struct GNUNET_TIME_Relative delay;
struct GNUNET_HashCode hc;
pl->hello_delay_task = NULL;
GNUNET_assert (NULL != pl->mq);
/* find applicable HELLOs */
fah.peer = pl;
fah.result = NULL;
fah.max_size = GNUNET_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 (NULL == fah.result)
return;
delay = GNUNET_TIME_absolute_get_remaining (pl->next_hello_allowed);
if (0 != delay.rel_value_us)
return;
want = GNUNET_HELLO_size (fah.result->hello);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Sending HELLO with %u bytes",
(unsigned int) want);
env = GNUNET_MQ_msg_copy (&fah.result->hello->header);
GNUNET_MQ_send (pl->mq, env);
/* avoid sending this one again soon */
GNUNET_CRYPTO_hash (&pl->pid, sizeof(struct GNUNET_PeerIdentity), &hc);
GNUNET_CONTAINER_bloomfilter_add (fah.result->filter, &hc);
GNUNET_STATISTICS_update (stats,
gettext_noop ("# HELLO messages gossipped"),
1,
GNUNET_NO);
/* prepare to send the next one */
pl->next_hello_allowed =
GNUNET_TIME_relative_to_absolute (HELLO_ADVERTISEMENT_MIN_FREQUENCY);
if (NULL != pl->hello_delay_task)
GNUNET_SCHEDULER_cancel (pl->hello_delay_task);
pl->hello_delay_task = GNUNET_SCHEDULER_add_now (&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!).
*
* @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 (NULL == peer->mq)
return GNUNET_YES;
if (NULL != peer->hello_delay_task)
{
GNUNET_SCHEDULER_cancel (peer->hello_delay_task);
peer->hello_delay_task = NULL;
}
peer->hello_delay_task =
GNUNET_SCHEDULER_add_now (&schedule_next_hello, peer);
return GNUNET_YES;
}
/**
* Method called whenever a peer connects.
*
* @param cls closure
* @param peer peer identity this notification is about
* @param mq message queue for communicating with @a peer
* @return our `struct Peer` for @a peer
*/
static void *
connect_notify (void *cls,
const struct GNUNET_PeerIdentity *peer,
struct GNUNET_MQ_Handle *mq)
{
struct Peer *pos;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Core told us that we are connecting to `%s'\n",
GNUNET_i2s (peer));
if (0 == GNUNET_memcmp (&my_identity, peer))
return NULL;
GNUNET_MQ_set_options (mq, GNUNET_MQ_PRIO_BEST_EFFORT);
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);
}
else
{
GNUNET_assert (NULL == pos->mq);
}
pos->mq = mq;
if (pos->is_friend)
{
friend_count++;
if ((friend_count == minimum_friend_count) && (GNUNET_YES != friends_only))
whitelist_peers ();
GNUNET_STATISTICS_set (stats,
gettext_noop ("# friends connected"),
friend_count,
GNUNET_NO);
}
reschedule_hellos (NULL, peer, pos);
return 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;
attempt_connect (pos);
return GNUNET_YES;
}
/**
* Add peers and schedule connection attempt
*
* @param cls unused, NULL
*/
static void
add_peer_task (void *cls)
{
add_task = NULL;
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
* @param internal_cls the `struct Peer` for this peer
*/
static void
disconnect_notify (void *cls,
const struct GNUNET_PeerIdentity *peer,
void *internal_cls)
{
struct Peer *pos = internal_cls;
if (NULL == pos)
return; /* myself, we're shutting down */
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Core told us that we disconnected from `%s'\n",
GNUNET_i2s (peer));
if (NULL == pos->mq)
{
GNUNET_break (0);
return;
}
pos->mq = NULL;
connection_count--;
if (NULL != pos->hello_delay_task)
{
GNUNET_SCHEDULER_cancel (pos->hello_delay_task);
pos->hello_delay_task = NULL;
}
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)) &&
(NULL == add_task))
add_task = GNUNET_SCHEDULER_add_now (&add_peer_task, NULL);
if ((friend_count < minimum_friend_count) && (NULL == blacklist))
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 == GNUNET_memcmp (&pid, &my_identity))
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 (NULL != peer->hello)
{
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 HELLO from peer `%s' for advertising\n",
GNUNET_i2s (&pid));
if (NULL != peer->hello)
{
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);
GNUNET_memcpy (peer->hello, hello, size);
}
if (NULL != peer->filter)
{
GNUNET_CONTAINER_bloomfilter_free (peer->filter);
peer->filter = NULL;
}
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 (NULL != err_msg)
{
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 (NULL != peer);
if (0 == GNUNET_memcmp (&my_identity, peer))
return; /* that's me! */
if (NULL == hello)
{
/* 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 (NULL != pos->filter)
{
GNUNET_CONTAINER_bloomfilter_free (pos->filter);
pos->filter = NULL;
}
if ((NULL == pos->mq) && (GNUNET_NO == pos->is_friend))
free_peer (NULL, &pos->pid, pos);
}
return;
}
consider_for_advertising (hello);
pos = GNUNET_CONTAINER_multipeermap_get (peers, peer);
if (NULL == pos)
pos = make_peer (peer, hello, GNUNET_NO);
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 == GNUNET_memcmp (pid, &my_identity))
{
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 ((GNUNET_YES == 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) && (GNUNET_NO == friends_only))
{
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) &&
(GNUNET_NO == friends_only))
{
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 with the peer identity of the sender
* @param message the actual HELLO message
* @return #GNUNET_OK if @a message is well-formed
* #GNUNET_SYSERR if @a message is invalid
*/
static int
check_hello (void *cls, const struct GNUNET_HELLO_Message *message)
{
struct GNUNET_PeerIdentity pid;
if (GNUNET_OK != GNUNET_HELLO_get_id (message, &pid))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* This function is called whenever an encrypted HELLO message is
* received.
*
* @param cls closure with the peer identity of the sender
* @param message the actual HELLO message
*/
static void
handle_hello (void *cls, const struct GNUNET_HELLO_Message *message)
{
const struct GNUNET_PeerIdentity *other = cls;
struct Peer *peer;
struct GNUNET_PeerIdentity pid;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Received encrypted HELLO from peer `%s'",
GNUNET_i2s (other));
GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_id (message, &pid));
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;
}
else
{
if ((GNUNET_YES != peer->is_friend) && (GNUNET_YES == friends_only))
return;
if ((GNUNET_YES != peer->is_friend) &&
(friend_count < minimum_friend_count))
return;
}
(void) GNUNET_PEERINFO_add_peer (pi, message, NULL, NULL);
}
/**
* Last task run during shutdown. Disconnects us from
* the transport and core.
*
* @param cls unused, NULL
*/
static void
cleaning_task (void *cls)
{
if (NULL != peerinfo_notify)
{
GNUNET_PEERINFO_notify_cancel (peerinfo_notify);
peerinfo_notify = NULL;
}
if (NULL != handle)
{
GNUNET_CORE_disconnect (handle);
handle = NULL;
}
whitelist_peers ();
if (NULL != add_task)
{
GNUNET_SCHEDULER_cancel (add_task);
add_task = NULL;
}
if (NULL != oh)
{
GNUNET_TRANSPORT_offer_hello_cancel (oh);
oh = NULL;
}
GNUNET_CONTAINER_multipeermap_iterate (peers, &free_peer, NULL);
GNUNET_CONTAINER_multipeermap_destroy (peers);
peers = NULL;
if (NULL != ats)
{
GNUNET_ATS_connectivity_done (ats);
ats = NULL;
}
if (NULL != pi)
{
GNUNET_PEERINFO_disconnect (pi);
pi = NULL;
}
if (NULL != stats)
{
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)
{
struct GNUNET_MQ_MessageHandler handlers[] =
{ GNUNET_MQ_hd_var_size (hello,
GNUNET_MESSAGE_TYPE_HELLO,
struct GNUNET_HELLO_Message,
NULL),
GNUNET_MQ_handler_end () };
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);
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 ((GNUNET_YES == friends_only) || (minimum_friend_count > 0))
blacklist = GNUNET_TRANSPORT_blacklist (cfg, &blacklist_check, NULL);
ats = GNUNET_ATS_connectivity_init (cfg);
pi = GNUNET_PEERINFO_connect (cfg);
handle = GNUNET_CORE_connect (cfg,
NULL,
&core_init,
&connect_notify,
&disconnect_notify,
handlers);
GNUNET_SCHEDULER_add_shutdown (&cleaning_task, NULL);
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"),
options,
&run,
NULL))
? 0
: 1;
GNUNET_free_nz ((void *) argv);
return ret;
}
#if defined(__linux__) && defined(__GLIBC__)
#include
/**
* 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 */