/*
This file is part of GNUnet.
Copyright (C) 2009-2017 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 .
*/
/**
* @file dht/gnunet-service-dht_neighbours.c
* @brief GNUnet DHT service's bucket and neighbour management code
* @author Christian Grothoff
* @author Nathan Evans
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_block_lib.h"
#include "gnunet_hello_lib.h"
#include "gnunet_constants.h"
#include "gnunet_protocols.h"
#include "gnunet_nse_service.h"
#include "gnunet_ats_service.h"
#include "gnunet_core_service.h"
#include "gnunet_datacache_lib.h"
#include "gnunet_transport_service.h"
#include "gnunet_hello_lib.h"
#include "gnunet_dht_service.h"
#include "gnunet_statistics_service.h"
#include "gnunet-service-dht.h"
#include "gnunet-service-dht_datacache.h"
#include "gnunet-service-dht_hello.h"
#include "gnunet-service-dht_neighbours.h"
#include "gnunet-service-dht_nse.h"
#include "gnunet-service-dht_routing.h"
#include "dht.h"
#define LOG_TRAFFIC(kind,...) GNUNET_log_from (kind, "dht-traffic",__VA_ARGS__)
/**
* Enable slow sanity checks to debug issues.
*/
#define SANITY_CHECKS 1
/**
* How many buckets will we allow total.
*/
#define MAX_BUCKETS sizeof (struct GNUNET_HashCode) * 8
/**
* What is the maximum number of peers in a given bucket.
*/
#define DEFAULT_BUCKET_SIZE 8
/**
* Desired replication level for FIND PEER requests
*/
#define FIND_PEER_REPLICATION_LEVEL 4
/**
* Maximum allowed replication level for all requests.
*/
#define MAXIMUM_REPLICATION_LEVEL 16
/**
* Maximum allowed number of pending messages per peer.
*/
#define MAXIMUM_PENDING_PER_PEER 64
/**
* How long at least to wait before sending another find peer request.
*/
#define DHT_MINIMUM_FIND_PEER_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 30)
/**
* How long at most to wait before sending another find peer request.
*/
#define DHT_MAXIMUM_FIND_PEER_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 10)
/**
* How long at most to wait for transmission of a GET request to another peer?
*/
#define GET_TIMEOUT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 2)
/**
* Hello address expiration
*/
extern struct GNUNET_TIME_Relative hello_expiration;
GNUNET_NETWORK_STRUCT_BEGIN
/**
* P2P PUT message
*/
struct PeerPutMessage
{
/**
* Type: #GNUNET_MESSAGE_TYPE_DHT_P2P_PUT
*/
struct GNUNET_MessageHeader header;
/**
* Processing options
*/
uint32_t options GNUNET_PACKED;
/**
* Content type.
*/
uint32_t type GNUNET_PACKED;
/**
* Hop count
*/
uint32_t hop_count GNUNET_PACKED;
/**
* Replication level for this message
*/
uint32_t desired_replication_level GNUNET_PACKED;
/**
* Length of the PUT path that follows (if tracked).
*/
uint32_t put_path_length GNUNET_PACKED;
/**
* When does the content expire?
*/
struct GNUNET_TIME_AbsoluteNBO expiration_time;
/**
* Bloomfilter (for peer identities) to stop circular routes
*/
char bloomfilter[DHT_BLOOM_SIZE];
/**
* The key we are storing under.
*/
struct GNUNET_HashCode key;
/* put path (if tracked) */
/* Payload */
};
/**
* P2P Result message
*/
struct PeerResultMessage
{
/**
* Type: #GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT
*/
struct GNUNET_MessageHeader header;
/**
* Content type.
*/
uint32_t type GNUNET_PACKED;
/**
* Length of the PUT path that follows (if tracked).
*/
uint32_t put_path_length GNUNET_PACKED;
/**
* Length of the GET path that follows (if tracked).
*/
uint32_t get_path_length GNUNET_PACKED;
/**
* When does the content expire?
*/
struct GNUNET_TIME_AbsoluteNBO expiration_time;
/**
* The key of the corresponding GET request.
*/
struct GNUNET_HashCode key;
/* put path (if tracked) */
/* get path (if tracked) */
/* Payload */
};
/**
* P2P GET message
*/
struct PeerGetMessage
{
/**
* Type: #GNUNET_MESSAGE_TYPE_DHT_P2P_GET
*/
struct GNUNET_MessageHeader header;
/**
* Processing options
*/
uint32_t options GNUNET_PACKED;
/**
* Desired content type.
*/
uint32_t type GNUNET_PACKED;
/**
* Hop count
*/
uint32_t hop_count GNUNET_PACKED;
/**
* Desired replication level for this request.
*/
uint32_t desired_replication_level GNUNET_PACKED;
/**
* Size of the extended query.
*/
uint32_t xquery_size;
/**
* Bloomfilter mutator.
*/
uint32_t bf_mutator;
/**
* Bloomfilter (for peer identities) to stop circular routes
*/
char bloomfilter[DHT_BLOOM_SIZE];
/**
* The key we are looking for.
*/
struct GNUNET_HashCode key;
/* xquery */
/* result bloomfilter */
};
GNUNET_NETWORK_STRUCT_END
/**
* Entry for a peer in a bucket.
*/
struct PeerInfo
{
/**
* Next peer entry (DLL)
*/
struct PeerInfo *next;
/**
* Prev peer entry (DLL)
*/
struct PeerInfo *prev;
/**
* Handle for sending messages to this peer.
*/
struct GNUNET_MQ_Handle *mq;
/**
* What is the identity of the peer?
*/
const struct GNUNET_PeerIdentity *id;
/**
* Hash of @e id.
*/
struct GNUNET_HashCode phash;
/**
* Which bucket is this peer in?
*/
int peer_bucket;
};
/**
* Peers are grouped into buckets.
*/
struct PeerBucket
{
/**
* Head of DLL
*/
struct PeerInfo *head;
/**
* Tail of DLL
*/
struct PeerInfo *tail;
/**
* Number of peers in the bucket.
*/
unsigned int peers_size;
};
/**
* Information about a peer that we would like to connect to.
*/
struct ConnectInfo
{
/**
* Handle to active HELLO offer operation, or NULL.
*/
struct GNUNET_TRANSPORT_OfferHelloHandle *oh;
/**
* Handle to active connectivity suggestion operation, or NULL.
*/
struct GNUNET_ATS_ConnectivitySuggestHandle *sh;
/**
* How much would we like to connect to this peer?
*/
uint32_t strength;
};
/**
* Do we cache all results that we are routing in the local datacache?
*/
static int cache_results;
/**
* Should routing details be logged to stderr (for debugging)?
*/
static int log_route_details_stderr;
/**
* The lowest currently used bucket, initially 0 (for 0-bits matching bucket).
*/
static unsigned int closest_bucket;
/**
* How many peers have we added since we sent out our last
* find peer request?
*/
static unsigned int newly_found_peers;
/**
* Option for testing that disables the 'connect' function of the DHT.
*/
static int disable_try_connect;
/**
* The buckets. Array of size #MAX_BUCKETS. Offset 0 means 0 bits matching.
*/
static struct PeerBucket k_buckets[MAX_BUCKETS];
/**
* Hash map of all CORE-connected peers, for easy removal from
* #k_buckets on disconnect. Values are of type `struct PeerInfo`.
*/
static struct GNUNET_CONTAINER_MultiPeerMap *all_connected_peers;
/**
* Hash map of all peers we would like to be connected to.
* Values are of type `struct ConnectInfo`.
*/
static struct GNUNET_CONTAINER_MultiPeerMap *all_desired_peers;
/**
* Maximum size for each bucket.
*/
static unsigned int bucket_size = DEFAULT_BUCKET_SIZE;
/**
* Task that sends FIND PEER requests.
*/
static struct GNUNET_SCHEDULER_Task *find_peer_task;
/**
* Identity of this peer.
*/
static struct GNUNET_PeerIdentity my_identity;
/**
* Hash of the identity of this peer.
*/
struct GNUNET_HashCode my_identity_hash;
/**
* Handle to CORE.
*/
static struct GNUNET_CORE_Handle *core_api;
/**
* Handle to ATS connectivity.
*/
static struct GNUNET_ATS_ConnectivityHandle *ats_ch;
/**
* Find the optimal bucket for this key.
*
* @param hc the hashcode to compare our identity to
* @return the proper bucket index, or #GNUNET_SYSERR
* on error (same hashcode)
*/
static int
find_bucket (const struct GNUNET_HashCode *hc)
{
unsigned int bits;
bits = GNUNET_CRYPTO_hash_matching_bits (&my_identity_hash, hc);
if (bits == MAX_BUCKETS)
{
/* How can all bits match? Got my own ID? */
GNUNET_break (0);
return GNUNET_SYSERR;
}
return MAX_BUCKETS - bits - 1;
}
/**
* Function called when #GNUNET_TRANSPORT_offer_hello() is done.
* Clean up the "oh" field in the @a cls
*
* @param cls a `struct ConnectInfo`
*/
static void
offer_hello_done (void *cls)
{
struct ConnectInfo *ci = cls;
ci->oh = NULL;
}
/**
* Function called for all entries in #all_desired_peers to clean up.
*
* @param cls NULL
* @param peer peer the entry is for
* @param value the value to remove
* @return #GNUNET_YES
*/
static int
free_connect_info (void *cls,
const struct GNUNET_PeerIdentity *peer,
void *value)
{
struct ConnectInfo *ci = value;
GNUNET_assert (GNUNET_YES ==
GNUNET_CONTAINER_multipeermap_remove (all_desired_peers,
peer,
ci));
if (NULL != ci->sh)
{
GNUNET_ATS_connectivity_suggest_cancel (ci->sh);
ci->sh = NULL;
}
if (NULL != ci->oh)
{
GNUNET_TRANSPORT_offer_hello_cancel (ci->oh);
ci->oh = NULL;
}
GNUNET_free (ci);
return GNUNET_YES;
}
/**
* Consider if we want to connect to a given peer, and if so
* let ATS know. If applicable, the HELLO is offered to the
* TRANSPORT service.
*
* @param pid peer to consider connectivity requirements for
* @param h a HELLO message, or NULL
*/
static void
try_connect (const struct GNUNET_PeerIdentity *pid,
const struct GNUNET_MessageHeader *h)
{
int bucket;
struct GNUNET_HashCode pid_hash;
struct ConnectInfo *ci;
uint32_t strength;
GNUNET_CRYPTO_hash (pid,
sizeof (struct GNUNET_PeerIdentity),
&pid_hash);
bucket = find_bucket (&pid_hash);
if (bucket < 0)
return; /* self? */
ci = GNUNET_CONTAINER_multipeermap_get (all_desired_peers,
pid);
if (k_buckets[bucket].peers_size < bucket_size)
strength = (bucket_size - k_buckets[bucket].peers_size) * bucket;
else
strength = bucket; /* minimum value of connectivity */
if (GNUNET_YES ==
GNUNET_CONTAINER_multipeermap_contains (all_connected_peers,
pid))
strength *= 2; /* double for connected peers */
else if (k_buckets[bucket].peers_size > bucket_size)
strength = 0; /* bucket full, we really do not care about more */
if ( (0 == strength) &&
(NULL != ci) )
{
/* release request */
GNUNET_assert (GNUNET_YES ==
free_connect_info (NULL,
pid,
ci));
return;
}
if (NULL == ci)
{
ci = GNUNET_new (struct ConnectInfo);
GNUNET_assert (GNUNET_OK ==
GNUNET_CONTAINER_multipeermap_put (all_desired_peers,
pid,
ci,
GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
}
if ( (NULL != ci->oh) &&
(NULL != h) )
GNUNET_TRANSPORT_offer_hello_cancel (ci->oh);
if (NULL != h)
ci->oh = GNUNET_TRANSPORT_offer_hello (GDS_cfg,
h,
&offer_hello_done,
ci);
if ( (NULL != ci->sh) &&
(ci->strength != strength) )
GNUNET_ATS_connectivity_suggest_cancel (ci->sh);
if (ci->strength != strength)
ci->sh = GNUNET_ATS_connectivity_suggest (ats_ch,
pid,
strength);
ci->strength = strength;
}
/**
* Function called for each peer in #all_desired_peers during
* #update_connect_preferences() if we have reason to adjust
* the strength of our desire to keep connections to certain
* peers. Calls #try_connect() to update the calculations for
* the given @a pid.
*
* @param cls NULL
* @param pid peer to update
* @param value unused
* @return #GNUNET_YES (continue to iterate)
*/
static int
update_desire_strength (void *cls,
const struct GNUNET_PeerIdentity *pid,
void *value)
{
try_connect (pid, NULL);
return GNUNET_YES;
}
/**
* Update our preferences for connectivity as given to ATS.
*
* @param cls the `struct PeerInfo` of the peer
* @param tc scheduler context.
*/
static void
update_connect_preferences ()
{
GNUNET_CONTAINER_multipeermap_iterate (all_desired_peers,
&update_desire_strength,
NULL);
}
/**
* Add each of the peers we already know to the bloom filter of
* the request so that we don't get duplicate HELLOs.
*
* @param cls the `struct GNUNET_BLOCK_Group`
* @param key peer identity to add to the bloom filter
* @param value value the peer information (unused)
* @return #GNUNET_YES (we should continue to iterate)
*/
static int
add_known_to_bloom (void *cls,
const struct GNUNET_PeerIdentity *key,
void *value)
{
struct GNUNET_BLOCK_Group *bg = cls;
struct GNUNET_HashCode key_hash;
GNUNET_CRYPTO_hash (key,
sizeof (struct GNUNET_PeerIdentity),
&key_hash);
GNUNET_BLOCK_group_set_seen (bg,
&key_hash,
1);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Adding known peer (%s) to bloomfilter for FIND PEER\n",
GNUNET_i2s (key));
return GNUNET_YES;
}
/**
* Task to send a find peer message for our own peer identifier
* so that we can find the closest peers in the network to ourselves
* and attempt to connect to them.
*
* @param cls closure for this task
*/
static void
send_find_peer_message (void *cls)
{
struct GNUNET_TIME_Relative next_send_time;
struct GNUNET_BLOCK_Group *bg;
struct GNUNET_CONTAINER_BloomFilter *peer_bf;
find_peer_task = NULL;
if (newly_found_peers > bucket_size)
{
/* If we are finding many peers already, no need to send out our request right now! */
find_peer_task =
GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
&send_find_peer_message,
NULL);
newly_found_peers = 0;
return;
}
bg = GNUNET_BLOCK_group_create (GDS_block_context,
GNUNET_BLOCK_TYPE_DHT_HELLO,
GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
UINT32_MAX),
NULL,
0,
"filter-size",
DHT_BLOOM_SIZE,
NULL);
GNUNET_CONTAINER_multipeermap_iterate (all_connected_peers,
&add_known_to_bloom,
bg);
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# FIND PEER messages initiated"),
1,
GNUNET_NO);
peer_bf
= GNUNET_CONTAINER_bloomfilter_init (NULL,
DHT_BLOOM_SIZE,
GNUNET_CONSTANTS_BLOOMFILTER_K);
// FIXME: pass priority!?
GDS_NEIGHBOURS_handle_get (GNUNET_BLOCK_TYPE_DHT_HELLO,
GNUNET_DHT_RO_FIND_PEER | GNUNET_DHT_RO_RECORD_ROUTE,
FIND_PEER_REPLICATION_LEVEL,
0,
&my_identity_hash,
NULL,
0,
bg,
peer_bf);
GNUNET_CONTAINER_bloomfilter_free (peer_bf);
GNUNET_BLOCK_group_destroy (bg);
/* schedule next round */
next_send_time.rel_value_us =
DHT_MINIMUM_FIND_PEER_INTERVAL.rel_value_us +
GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK,
DHT_MAXIMUM_FIND_PEER_INTERVAL.rel_value_us /
(newly_found_peers + 1));
newly_found_peers = 0;
GNUNET_assert (NULL == find_peer_task);
find_peer_task =
GNUNET_SCHEDULER_add_delayed (next_send_time,
&send_find_peer_message,
NULL);
}
/**
* Method called whenever a peer connects.
*
* @param cls closure
* @param peer peer identity this notification is about
* @param mq message queue for sending messages to @a peer
* @return our `struct PeerInfo` for @a peer
*/
static void *
handle_core_connect (void *cls,
const struct GNUNET_PeerIdentity *peer,
struct GNUNET_MQ_Handle *mq)
{
struct PeerInfo *pi;
/* Check for connect to self message */
if (0 == memcmp (&my_identity,
peer,
sizeof (struct GNUNET_PeerIdentity)))
return NULL;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Connected to %s\n",
GNUNET_i2s (peer));
GNUNET_assert (GNUNET_NO ==
GNUNET_CONTAINER_multipeermap_get (all_connected_peers,
peer));
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# peers connected"),
1,
GNUNET_NO);
pi = GNUNET_new (struct PeerInfo);
pi->id = peer;
pi->mq = mq;
GNUNET_CRYPTO_hash (peer,
sizeof (struct GNUNET_PeerIdentity),
&pi->phash);
pi->peer_bucket = find_bucket (&pi->phash);
GNUNET_assert ( (pi->peer_bucket >= 0) &&
(pi->peer_bucket < MAX_BUCKETS) );
GNUNET_CONTAINER_DLL_insert_tail (k_buckets[pi->peer_bucket].head,
k_buckets[pi->peer_bucket].tail,
pi);
k_buckets[pi->peer_bucket].peers_size++;
closest_bucket = GNUNET_MAX (closest_bucket,
pi->peer_bucket);
GNUNET_assert (GNUNET_OK ==
GNUNET_CONTAINER_multipeermap_put (all_connected_peers,
pi->id,
pi,
GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
if ( (pi->peer_bucket > 0) &&
(k_buckets[pi->peer_bucket].peers_size <= bucket_size))
{
update_connect_preferences ();
newly_found_peers++;
}
if ( (1 == GNUNET_CONTAINER_multipeermap_size (all_connected_peers)) &&
(GNUNET_YES != disable_try_connect))
{
/* got a first connection, good time to start with FIND PEER requests... */
GNUNET_assert (NULL == find_peer_task);
find_peer_task = GNUNET_SCHEDULER_add_now (&send_find_peer_message,
NULL);
}
return pi;
}
/**
* Method called whenever a peer disconnects.
*
* @param cls closure
* @param peer peer identity this notification is about
* @param internal_cls our `struct PeerInfo` for @a peer
*/
static void
handle_core_disconnect (void *cls,
const struct GNUNET_PeerIdentity *peer,
void *internal_cls)
{
struct PeerInfo *to_remove = internal_cls;
/* Check for disconnect from self message */
if (NULL == to_remove)
return;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Disconnected %s\n",
GNUNET_i2s (peer));
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# peers connected"),
-1,
GNUNET_NO);
GNUNET_assert (GNUNET_YES ==
GNUNET_CONTAINER_multipeermap_remove (all_connected_peers,
peer,
to_remove));
if ( (0 == GNUNET_CONTAINER_multipeermap_size (all_connected_peers)) &&
(GNUNET_YES != disable_try_connect) )
{
GNUNET_SCHEDULER_cancel (find_peer_task);
find_peer_task = NULL;
}
GNUNET_assert (to_remove->peer_bucket >= 0);
GNUNET_CONTAINER_DLL_remove (k_buckets[to_remove->peer_bucket].head,
k_buckets[to_remove->peer_bucket].tail,
to_remove);
GNUNET_assert (k_buckets[to_remove->peer_bucket].peers_size > 0);
k_buckets[to_remove->peer_bucket].peers_size--;
while ( (closest_bucket > 0) &&
(0 == k_buckets[to_remove->peer_bucket].peers_size) )
closest_bucket--;
if (k_buckets[to_remove->peer_bucket].peers_size < bucket_size)
update_connect_preferences ();
GNUNET_free (to_remove);
}
/**
* To how many peers should we (on average) forward the request to
* obtain the desired target_replication count (on average).
*
* @param hop_count number of hops the message has traversed
* @param target_replication the number of total paths desired
* @return Some number of peers to forward the message to
*/
static unsigned int
get_forward_count (uint32_t hop_count,
uint32_t target_replication)
{
uint32_t random_value;
uint32_t forward_count;
float target_value;
if (hop_count > GDS_NSE_get () * 4.0)
{
/* forcefully terminate */
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# requests TTL-dropped"),
1, GNUNET_NO);
return 0;
}
if (hop_count > GDS_NSE_get () * 2.0)
{
/* Once we have reached our ideal number of hops, only forward to 1 peer */
return 1;
}
/* bound by system-wide maximum */
target_replication =
GNUNET_MIN (MAXIMUM_REPLICATION_LEVEL, target_replication);
target_value =
1 + (target_replication - 1.0) / (GDS_NSE_get () +
((float) (target_replication - 1.0) *
hop_count));
/* Set forward count to floor of target_value */
forward_count = (uint32_t) target_value;
/* Subtract forward_count (floor) from target_value (yields value between 0 and 1) */
target_value = target_value - forward_count;
random_value =
GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
if (random_value < (target_value * UINT32_MAX))
forward_count++;
return forward_count;
}
/**
* Compute the distance between have and target as a 32-bit value.
* Differences in the lower bits must count stronger than differences
* in the higher bits.
*
* @param target
* @param have
* @return 0 if have==target, otherwise a number
* that is larger as the distance between
* the two hash codes increases
*/
static unsigned int
get_distance (const struct GNUNET_HashCode *target,
const struct GNUNET_HashCode *have)
{
unsigned int bucket;
unsigned int msb;
unsigned int lsb;
unsigned int i;
/* We have to represent the distance between two 2^9 (=512)-bit
* numbers as a 2^5 (=32)-bit number with "0" being used for the
* two numbers being identical; furthermore, we need to
* guarantee that a difference in the number of matching
* bits is always represented in the result.
*
* We use 2^32/2^9 numerical values to distinguish between
* hash codes that have the same LSB bit distance and
* use the highest 2^9 bits of the result to signify the
* number of (mis)matching LSB bits; if we have 0 matching
* and hence 512 mismatching LSB bits we return -1 (since
* 512 itself cannot be represented with 9 bits) */
/* first, calculate the most significant 9 bits of our
* result, aka the number of LSBs */
bucket = GNUNET_CRYPTO_hash_matching_bits (target,
have);
/* bucket is now a value between 0 and 512 */
if (bucket == 512)
return 0; /* perfect match */
if (bucket == 0)
return (unsigned int) -1; /* LSB differs; use max (if we did the bit-shifting
* below, we'd end up with max+1 (overflow)) */
/* calculate the most significant bits of the final result */
msb = (512 - bucket) << (32 - 9);
/* calculate the 32-9 least significant bits of the final result by
* looking at the differences in the 32-9 bits following the
* mismatching bit at 'bucket' */
lsb = 0;
for (i = bucket + 1;
(i < sizeof (struct GNUNET_HashCode) * 8) && (i < bucket + 1 + 32 - 9); i++)
{
if (GNUNET_CRYPTO_hash_get_bit (target, i) !=
GNUNET_CRYPTO_hash_get_bit (have, i))
lsb |= (1 << (bucket + 32 - 9 - i)); /* first bit set will be 10,
* last bit set will be 31 -- if
* i does not reach 512 first... */
}
return msb | lsb;
}
/**
* Check whether my identity is closer than any known peers. If a
* non-null bloomfilter is given, check if this is the closest peer
* that hasn't already been routed to.
*
* @param key hash code to check closeness to
* @param bloom bloomfilter, exclude these entries from the decision
* @return #GNUNET_YES if node location is closest,
* #GNUNET_NO otherwise.
*/
int
GDS_am_closest_peer (const struct GNUNET_HashCode *key,
const struct GNUNET_CONTAINER_BloomFilter *bloom)
{
int bits;
int other_bits;
int bucket_num;
int count;
struct PeerInfo *pos;
if (0 == memcmp (&my_identity_hash, key, sizeof (struct GNUNET_HashCode)))
return GNUNET_YES;
bucket_num = find_bucket (key);
GNUNET_assert (bucket_num >= 0);
bits = GNUNET_CRYPTO_hash_matching_bits (&my_identity_hash,
key);
pos = k_buckets[bucket_num].head;
count = 0;
while ((NULL != pos) && (count < bucket_size))
{
if ((NULL != bloom) &&
(GNUNET_YES ==
GNUNET_CONTAINER_bloomfilter_test (bloom,
&pos->phash)))
{
pos = pos->next;
continue; /* Skip already checked entries */
}
other_bits = GNUNET_CRYPTO_hash_matching_bits (&pos->phash,
key);
if (other_bits > bits)
return GNUNET_NO;
if (other_bits == bits) /* We match the same number of bits */
return GNUNET_YES;
pos = pos->next;
}
/* No peers closer, we are the closest! */
return GNUNET_YES;
}
/**
* Select a peer from the routing table that would be a good routing
* destination for sending a message for "key". The resulting peer
* must not be in the set of blocked peers.
*
* Note that we should not ALWAYS select the closest peer to the
* target, peers further away from the target should be chosen with
* exponentially declining probability.
*
* FIXME: double-check that this is fine
*
*
* @param key the key we are selecting a peer to route to
* @param bloom a bloomfilter containing entries this request has seen already
* @param hops how many hops has this message traversed thus far
* @return Peer to route to, or NULL on error
*/
static struct PeerInfo *
select_peer (const struct GNUNET_HashCode *key,
const struct GNUNET_CONTAINER_BloomFilter *bloom,
uint32_t hops)
{
unsigned int bc;
unsigned int count;
unsigned int selected;
struct PeerInfo *pos;
unsigned int dist;
unsigned int smallest_distance;
struct PeerInfo *chosen;
if (hops >= GDS_NSE_get ())
{
/* greedy selection (closest peer that is not in bloomfilter) */
smallest_distance = UINT_MAX;
chosen = NULL;
for (bc = 0; bc <= closest_bucket; bc++)
{
pos = k_buckets[bc].head;
count = 0;
while ((pos != NULL) && (count < bucket_size))
{
if ( (NULL == bloom) ||
(GNUNET_NO ==
GNUNET_CONTAINER_bloomfilter_test (bloom,
&pos->phash)))
{
dist = get_distance (key,
&pos->phash);
if (dist < smallest_distance)
{
chosen = pos;
smallest_distance = dist;
}
}
else
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Excluded peer `%s' due to BF match in greedy routing for %s\n",
GNUNET_i2s (pos->id),
GNUNET_h2s (key));
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# Peers excluded from routing due to Bloomfilter"),
1,
GNUNET_NO);
dist = get_distance (key,
&pos->phash);
if (dist < smallest_distance)
{
chosen = NULL;
smallest_distance = dist;
}
}
count++;
pos = pos->next;
}
}
if (NULL == chosen)
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# Peer selection failed"),
1,
GNUNET_NO);
else
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Selected peer `%s' in greedy routing for %s\n",
GNUNET_i2s (chosen->id),
GNUNET_h2s (key));
return chosen;
}
/* select "random" peer */
/* count number of peers that are available and not filtered */
count = 0;
for (bc = 0; bc <= closest_bucket; bc++)
{
pos = k_buckets[bc].head;
while ( (NULL != pos) && (count < bucket_size) )
{
if ( (NULL != bloom) &&
(GNUNET_YES ==
GNUNET_CONTAINER_bloomfilter_test (bloom,
&pos->phash)) )
{
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop
("# Peers excluded from routing due to Bloomfilter"),
1, GNUNET_NO);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Excluded peer `%s' due to BF match in random routing for %s\n",
GNUNET_i2s (pos->id),
GNUNET_h2s (key));
pos = pos->next;
continue; /* Ignore bloomfiltered peers */
}
count++;
pos = pos->next;
}
}
if (0 == count) /* No peers to select from! */
{
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# Peer selection failed"), 1,
GNUNET_NO);
return NULL;
}
/* Now actually choose a peer */
selected = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
count);
count = 0;
for (bc = 0; bc <= closest_bucket; bc++)
{
for (pos = k_buckets[bc].head; ((pos != NULL) && (count < bucket_size)); pos = pos->next)
{
if ((bloom != NULL) &&
(GNUNET_YES ==
GNUNET_CONTAINER_bloomfilter_test (bloom,
&pos->phash)))
{
continue; /* Ignore bloomfiltered peers */
}
if (0 == selected--)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Selected peer `%s' in random routing for %s\n",
GNUNET_i2s (pos->id),
GNUNET_h2s (key));
return pos;
}
}
}
GNUNET_break (0);
return NULL;
}
/**
* Compute the set of peers that the given request should be
* forwarded to.
*
* @param key routing key
* @param bloom bloom filter excluding peers as targets, all selected
* peers will be added to the bloom filter
* @param hop_count number of hops the request has traversed so far
* @param target_replication desired number of replicas
* @param targets where to store an array of target peers (to be
* free'd by the caller)
* @return number of peers returned in 'targets'.
*/
static unsigned int
get_target_peers (const struct GNUNET_HashCode *key,
struct GNUNET_CONTAINER_BloomFilter *bloom,
uint32_t hop_count,
uint32_t target_replication,
struct PeerInfo ***targets)
{
unsigned int ret;
unsigned int off;
struct PeerInfo **rtargets;
struct PeerInfo *nxt;
GNUNET_assert (NULL != bloom);
ret = get_forward_count (hop_count,
target_replication);
if (0 == ret)
{
*targets = NULL;
return 0;
}
rtargets = GNUNET_new_array (ret,
struct PeerInfo *);
for (off = 0; off < ret; off++)
{
nxt = select_peer (key,
bloom,
hop_count);
if (NULL == nxt)
break;
rtargets[off] = nxt;
GNUNET_break (GNUNET_NO ==
GNUNET_CONTAINER_bloomfilter_test (bloom,
&nxt->phash));
GNUNET_CONTAINER_bloomfilter_add (bloom,
&nxt->phash);
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Selected %u/%u peers at hop %u for %s (target was %u)\n",
off,
GNUNET_CONTAINER_multipeermap_size (all_connected_peers),
(unsigned int) hop_count,
GNUNET_h2s (key),
ret);
if (0 == off)
{
GNUNET_free (rtargets);
*targets = NULL;
return 0;
}
*targets = rtargets;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Forwarding query `%s' to %u peers (goal was %u peers)\n",
GNUNET_h2s (key),
off,
ret);
return off;
}
/**
* Perform a PUT operation. Forwards the given request to other
* peers. Does not store the data locally. Does not give the
* data to local clients. May do nothing if this is the only
* peer in the network (or if we are the closest peer in the
* network).
*
* @param type type of the block
* @param options routing options
* @param desired_replication_level desired replication count
* @param expiration_time when does the content expire
* @param hop_count how many hops has this message traversed so far
* @param bf Bloom filter of peers this PUT has already traversed
* @param key key for the content
* @param put_path_length number of entries in @a put_path
* @param put_path peers this request has traversed so far (if tracked)
* @param data payload to store
* @param data_size number of bytes in @a data
* @return #GNUNET_OK if the request was forwarded, #GNUNET_NO if not
*/
int
GDS_NEIGHBOURS_handle_put (enum GNUNET_BLOCK_Type type,
enum GNUNET_DHT_RouteOption options,
uint32_t desired_replication_level,
struct GNUNET_TIME_Absolute expiration_time,
uint32_t hop_count,
struct GNUNET_CONTAINER_BloomFilter *bf,
const struct GNUNET_HashCode *key,
unsigned int put_path_length,
struct GNUNET_PeerIdentity *put_path,
const void *data,
size_t data_size)
{
unsigned int target_count;
unsigned int i;
struct PeerInfo **targets;
struct PeerInfo *target;
size_t msize;
struct GNUNET_MQ_Envelope *env;
struct PeerPutMessage *ppm;
struct GNUNET_PeerIdentity *pp;
unsigned int skip_count;
GNUNET_assert (NULL != bf);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Adding myself (%s) to PUT bloomfilter for %s\n",
GNUNET_i2s (&my_identity),
GNUNET_h2s (key));
GNUNET_CONTAINER_bloomfilter_add (bf,
&my_identity_hash);
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# PUT requests routed"),
1,
GNUNET_NO);
target_count
= get_target_peers (key,
bf,
hop_count,
desired_replication_level,
&targets);
if (0 == target_count)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Routing PUT for %s terminates after %u hops at %s\n",
GNUNET_h2s (key),
(unsigned int) hop_count,
GNUNET_i2s (&my_identity));
return GNUNET_NO;
}
msize = put_path_length * sizeof (struct GNUNET_PeerIdentity) + data_size;
if (msize + sizeof (struct PeerPutMessage)
>= GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE)
{
put_path_length = 0;
msize = data_size;
}
if (msize + sizeof (struct PeerPutMessage)
>= GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE)
{
GNUNET_break (0);
GNUNET_free (targets);
return GNUNET_NO;
}
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# PUT messages queued for transmission"),
target_count,
GNUNET_NO);
skip_count = 0;
for (i = 0; i < target_count; i++)
{
target = targets[i];
if (GNUNET_MQ_get_length (target->mq) >= MAXIMUM_PENDING_PER_PEER)
{
/* skip */
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# P2P messages dropped due to full queue"),
1,
GNUNET_NO);
skip_count++;
continue;
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Routing PUT for %s after %u hops to %s\n",
GNUNET_h2s (key),
(unsigned int) hop_count,
GNUNET_i2s (target->id));
env = GNUNET_MQ_msg_extra (ppm,
msize,
GNUNET_MESSAGE_TYPE_DHT_P2P_PUT);
ppm->options = htonl (options);
ppm->type = htonl (type);
ppm->hop_count = htonl (hop_count + 1);
ppm->desired_replication_level = htonl (desired_replication_level);
ppm->put_path_length = htonl (put_path_length);
ppm->expiration_time = GNUNET_TIME_absolute_hton (expiration_time);
GNUNET_break (GNUNET_YES ==
GNUNET_CONTAINER_bloomfilter_test (bf,
&target->phash));
GNUNET_assert (GNUNET_OK ==
GNUNET_CONTAINER_bloomfilter_get_raw_data (bf,
ppm->bloomfilter,
DHT_BLOOM_SIZE));
ppm->key = *key;
pp = (struct GNUNET_PeerIdentity *) &ppm[1];
GNUNET_memcpy (pp,
put_path,
sizeof (struct GNUNET_PeerIdentity) * put_path_length);
GNUNET_memcpy (&pp[put_path_length],
data,
data_size);
GNUNET_MQ_send (target->mq,
env);
}
GNUNET_free (targets);
return (skip_count < target_count) ? GNUNET_OK : GNUNET_NO;
}
/**
* Perform a GET operation. Forwards the given request to other
* peers. Does not lookup the key locally. May do nothing if this is
* the only peer in the network (or if we are the closest peer in the
* network).
*
* @param type type of the block
* @param options routing options
* @param desired_replication_level desired replication count
* @param hop_count how many hops did this request traverse so far?
* @param key key for the content
* @param xquery extended query
* @param xquery_size number of bytes in @a xquery
* @param bg group to use for filtering replies
* @param peer_bf filter for peers not to select (again)
* @return #GNUNET_OK if the request was forwarded, #GNUNET_NO if not
*/
int
GDS_NEIGHBOURS_handle_get (enum GNUNET_BLOCK_Type type,
enum GNUNET_DHT_RouteOption options,
uint32_t desired_replication_level,
uint32_t hop_count,
const struct GNUNET_HashCode *key,
const void *xquery,
size_t xquery_size,
struct GNUNET_BLOCK_Group *bg,
struct GNUNET_CONTAINER_BloomFilter *peer_bf)
{
unsigned int target_count;
struct PeerInfo **targets;
struct PeerInfo *target;
struct GNUNET_MQ_Envelope *env;
size_t msize;
struct PeerGetMessage *pgm;
char *xq;
size_t reply_bf_size;
void *reply_bf;
unsigned int skip_count;
uint32_t bf_nonce;
GNUNET_assert (NULL != peer_bf);
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# GET requests routed"),
1,
GNUNET_NO);
target_count = get_target_peers (key,
peer_bf,
hop_count,
desired_replication_level,
&targets);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Adding myself (%s) to GET bloomfilter for %s\n",
GNUNET_i2s (&my_identity),
GNUNET_h2s (key));
GNUNET_CONTAINER_bloomfilter_add (peer_bf,
&my_identity_hash);
if (0 == target_count)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Routing GET for %s terminates after %u hops at %s\n",
GNUNET_h2s (key),
(unsigned int) hop_count,
GNUNET_i2s (&my_identity));
return GNUNET_NO;
}
if (GNUNET_OK !=
GNUNET_BLOCK_group_serialize (bg,
&bf_nonce,
&reply_bf,
&reply_bf_size))
{
reply_bf = NULL;
reply_bf_size = 0;
bf_nonce = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
UINT32_MAX);
}
msize = xquery_size + reply_bf_size;
if (msize + sizeof (struct PeerGetMessage) >= GNUNET_MAX_MESSAGE_SIZE)
{
GNUNET_break (0);
GNUNET_free_non_null (reply_bf);
GNUNET_free (targets);
return GNUNET_NO;
}
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# GET messages queued for transmission"),
target_count,
GNUNET_NO);
/* forward request */
skip_count = 0;
for (unsigned int i = 0; i < target_count; i++)
{
target = targets[i];
if (GNUNET_MQ_get_length (target->mq) >= MAXIMUM_PENDING_PER_PEER)
{
/* skip */
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# P2P messages dropped due to full queue"),
1, GNUNET_NO);
skip_count++;
continue;
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Routing GET for %s after %u hops to %s\n",
GNUNET_h2s (key),
(unsigned int) hop_count,
GNUNET_i2s (target->id));
env = GNUNET_MQ_msg_extra (pgm,
msize,
GNUNET_MESSAGE_TYPE_DHT_P2P_GET);
pgm->options = htonl (options);
pgm->type = htonl (type);
pgm->hop_count = htonl (hop_count + 1);
pgm->desired_replication_level = htonl (desired_replication_level);
pgm->xquery_size = htonl (xquery_size);
pgm->bf_mutator = bf_nonce;
GNUNET_break (GNUNET_YES ==
GNUNET_CONTAINER_bloomfilter_test (peer_bf,
&target->phash));
GNUNET_assert (GNUNET_OK ==
GNUNET_CONTAINER_bloomfilter_get_raw_data (peer_bf,
pgm->bloomfilter,
DHT_BLOOM_SIZE));
pgm->key = *key;
xq = (char *) &pgm[1];
GNUNET_memcpy (xq,
xquery,
xquery_size);
GNUNET_memcpy (&xq[xquery_size],
reply_bf,
reply_bf_size);
GNUNET_MQ_send (target->mq,
env);
}
GNUNET_free (targets);
GNUNET_free_non_null (reply_bf);
return (skip_count < target_count) ? GNUNET_OK : GNUNET_NO;
}
/**
* Handle a reply (route to origin). Only forwards the reply back to
* the given peer. Does not do local caching or forwarding to local
* clients.
*
* @param target neighbour that should receive the block (if still connected)
* @param type type of the block
* @param expiration_time when does the content expire
* @param key key for the content
* @param put_path_length number of entries in @a put_path
* @param put_path peers the original PUT traversed (if tracked)
* @param get_path_length number of entries in @a get_path
* @param get_path peers this reply has traversed so far (if tracked)
* @param data payload of the reply
* @param data_size number of bytes in @a data
*/
void
GDS_NEIGHBOURS_handle_reply (const struct GNUNET_PeerIdentity *target,
enum GNUNET_BLOCK_Type type,
struct GNUNET_TIME_Absolute expiration_time,
const struct GNUNET_HashCode *key,
unsigned int put_path_length,
const struct GNUNET_PeerIdentity *put_path,
unsigned int get_path_length,
const struct GNUNET_PeerIdentity *get_path,
const void *data,
size_t data_size)
{
struct PeerInfo *pi;
struct GNUNET_MQ_Envelope *env;
size_t msize;
struct PeerResultMessage *prm;
struct GNUNET_PeerIdentity *paths;
msize = data_size + (get_path_length + put_path_length) *
sizeof (struct GNUNET_PeerIdentity);
if ((msize + sizeof (struct PeerResultMessage) >= GNUNET_MAX_MESSAGE_SIZE) ||
(get_path_length >
GNUNET_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
(put_path_length >
GNUNET_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
(data_size > GNUNET_MAX_MESSAGE_SIZE))
{
GNUNET_break (0);
return;
}
pi = GNUNET_CONTAINER_multipeermap_get (all_connected_peers,
target);
if (NULL == pi)
{
/* peer disconnected in the meantime, drop reply */
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"No matching peer for reply for key %s\n",
GNUNET_h2s (key));
return;
}
if (GNUNET_MQ_get_length (pi->mq) >= MAXIMUM_PENDING_PER_PEER)
{
/* skip */
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# P2P messages dropped due to full queue"),
1,
GNUNET_NO);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Peer queue full, ignoring reply for key %s\n",
GNUNET_h2s (key));
return;
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Forwarding reply for key %s to peer %s\n",
GNUNET_h2s (key),
GNUNET_i2s (target));
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop
("# RESULT messages queued for transmission"), 1,
GNUNET_NO);
env = GNUNET_MQ_msg_extra (prm,
msize,
GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT);
prm->type = htonl (type);
prm->put_path_length = htonl (put_path_length);
prm->get_path_length = htonl (get_path_length);
prm->expiration_time = GNUNET_TIME_absolute_hton (expiration_time);
prm->key = *key;
paths = (struct GNUNET_PeerIdentity *) &prm[1];
GNUNET_memcpy (paths,
put_path,
put_path_length * sizeof (struct GNUNET_PeerIdentity));
GNUNET_memcpy (&paths[put_path_length],
get_path,
get_path_length * sizeof (struct GNUNET_PeerIdentity));
GNUNET_memcpy (&paths[put_path_length + get_path_length],
data,
data_size);
GNUNET_MQ_send (pi->mq,
env);
}
/**
* To be called on core init/fail.
*
* @param cls service closure
* @param identity the public identity of this peer
*/
static void
core_init (void *cls,
const struct GNUNET_PeerIdentity *identity)
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"CORE called, I am %s\n",
GNUNET_i2s (identity));
my_identity = *identity;
GNUNET_CRYPTO_hash (identity,
sizeof (struct GNUNET_PeerIdentity),
&my_identity_hash);
GNUNET_SERVICE_resume (GDS_service);
}
/**
* Check validity of a p2p put request.
*
* @param cls closure with the `struct PeerInfo` of the sender
* @param message message
* @return #GNUNET_OK if the message is valid
*/
static int
check_dht_p2p_put (void *cls,
const struct PeerPutMessage *put)
{
uint32_t putlen;
uint16_t msize;
msize = ntohs (put->header.size);
putlen = ntohl (put->put_path_length);
if ((msize <
sizeof (struct PeerPutMessage) +
putlen * sizeof (struct GNUNET_PeerIdentity)) ||
(putlen >
GNUNET_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Core handler for p2p put requests.
*
* @param cls closure with the `struct PeerInfo` of the sender
* @param message message
*/
static void
handle_dht_p2p_put (void *cls,
const struct PeerPutMessage *put)
{
struct PeerInfo *peer = cls;
const struct GNUNET_PeerIdentity *put_path;
const void *payload;
uint32_t putlen;
uint16_t msize;
size_t payload_size;
enum GNUNET_DHT_RouteOption options;
struct GNUNET_CONTAINER_BloomFilter *bf;
struct GNUNET_HashCode test_key;
int forwarded;
msize = ntohs (put->header.size);
putlen = ntohl (put->put_path_length);
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# P2P PUT requests received"),
1,
GNUNET_NO);
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# P2P PUT bytes received"),
msize,
GNUNET_NO);
put_path = (const struct GNUNET_PeerIdentity *) &put[1];
payload = &put_path[putlen];
options = ntohl (put->options);
payload_size = msize - (sizeof (struct PeerPutMessage) +
putlen * sizeof (struct GNUNET_PeerIdentity));
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"PUT for `%s' from %s\n",
GNUNET_h2s (&put->key),
GNUNET_i2s (peer->id));
if (GNUNET_YES == log_route_details_stderr)
{
char *tmp;
char *pp;
pp = GNUNET_STRINGS_pp2s (put_path,
putlen);
tmp = GNUNET_strdup (GNUNET_i2s (&my_identity));
LOG_TRAFFIC (GNUNET_ERROR_TYPE_DEBUG,
"R5N PUT %s: %s->%s (%u, %u=>%u, PP: %s)\n",
GNUNET_h2s (&put->key),
GNUNET_i2s (peer->id),
tmp,
ntohl(put->hop_count),
GNUNET_CRYPTO_hash_matching_bits (&peer->phash,
&put->key),
GNUNET_CRYPTO_hash_matching_bits (&my_identity_hash,
&put->key),
pp);
GNUNET_free (pp);
GNUNET_free (tmp);
}
switch (GNUNET_BLOCK_get_key
(GDS_block_context,
ntohl (put->type),
payload,
payload_size,
&test_key))
{
case GNUNET_YES:
if (0 != memcmp (&test_key,
&put->key,
sizeof (struct GNUNET_HashCode)))
{
char *put_s = GNUNET_strdup (GNUNET_h2s_full (&put->key));
GNUNET_break_op (0);
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"PUT with key `%s' for block with key %s\n",
put_s,
GNUNET_h2s_full (&test_key));
GNUNET_free (put_s);
return;
}
break;
case GNUNET_NO:
GNUNET_break_op (0);
return;
case GNUNET_SYSERR:
/* cannot verify, good luck */
break;
}
if (ntohl (put->type) == GNUNET_BLOCK_TYPE_REGEX) /* FIXME: do for all tpyes */
{
switch (GNUNET_BLOCK_evaluate (GDS_block_context,
ntohl (put->type),
NULL, /* query group */
GNUNET_BLOCK_EO_NONE,
NULL, /* query */
NULL, 0, /* xquery */
payload,
payload_size))
{
case GNUNET_BLOCK_EVALUATION_OK_MORE:
case GNUNET_BLOCK_EVALUATION_OK_LAST:
break;
case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
case GNUNET_BLOCK_EVALUATION_RESULT_INVALID:
case GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT:
case GNUNET_BLOCK_EVALUATION_REQUEST_VALID:
case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID:
case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED:
default:
GNUNET_break_op (0);
return;
}
}
bf = GNUNET_CONTAINER_bloomfilter_init (put->bloomfilter,
DHT_BLOOM_SIZE,
GNUNET_CONSTANTS_BLOOMFILTER_K);
GNUNET_break_op (GNUNET_YES ==
GNUNET_CONTAINER_bloomfilter_test (bf,
&peer->phash));
{
struct GNUNET_PeerIdentity pp[putlen + 1];
/* extend 'put path' by sender */
if (0 != (options & GNUNET_DHT_RO_RECORD_ROUTE))
{
#if SANITY_CHECKS
for (unsigned int i=0;i<=putlen;i++)
{
for (unsigned int j=0;jid,
sizeof (struct GNUNET_PeerIdentity)));
}
#endif
GNUNET_memcpy (pp,
put_path,
putlen * sizeof (struct GNUNET_PeerIdentity));
pp[putlen] = *peer->id;
putlen++;
}
else
putlen = 0;
/* give to local clients */
GDS_CLIENTS_handle_reply (GNUNET_TIME_absolute_ntoh (put->expiration_time),
&put->key,
0,
NULL,
putlen,
pp,
ntohl (put->type),
payload_size,
payload);
/* store locally */
if ((0 != (options & GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE)) ||
(GDS_am_closest_peer (&put->key, bf)))
GDS_DATACACHE_handle_put (GNUNET_TIME_absolute_ntoh (put->expiration_time),
&put->key,
putlen,
pp,
ntohl (put->type),
payload_size,
payload);
/* route to other peers */
forwarded = GDS_NEIGHBOURS_handle_put (ntohl (put->type),
options,
ntohl (put->desired_replication_level),
GNUNET_TIME_absolute_ntoh (put->expiration_time),
ntohl (put->hop_count),
bf,
&put->key,
putlen,
pp,
payload,
payload_size);
/* notify monitoring clients */
GDS_CLIENTS_process_put (options
| ( (GNUNET_OK == forwarded)
? GNUNET_DHT_RO_LAST_HOP
: 0 ),
ntohl (put->type),
ntohl (put->hop_count),
ntohl (put->desired_replication_level),
putlen, pp,
GNUNET_TIME_absolute_ntoh (put->expiration_time),
&put->key,
payload,
payload_size);
}
GNUNET_CONTAINER_bloomfilter_free (bf);
}
/**
* We have received a FIND PEER request. Send matching
* HELLOs back.
*
* @param sender sender of the FIND PEER request
* @param key peers close to this key are desired
* @param bg group for filtering peers
*/
static void
handle_find_peer (const struct GNUNET_PeerIdentity *sender,
const struct GNUNET_HashCode *key,
struct GNUNET_BLOCK_Group *bg)
{
int bucket_idx;
struct PeerBucket *bucket;
struct PeerInfo *peer;
unsigned int choice;
const struct GNUNET_HELLO_Message *hello;
size_t hello_size;
/* first, check about our own HELLO */
if (NULL != GDS_my_hello)
{
hello_size = GNUNET_HELLO_size ((const struct GNUNET_HELLO_Message *) GDS_my_hello);
GNUNET_break (hello_size >= sizeof (struct GNUNET_MessageHeader));
if (GNUNET_BLOCK_EVALUATION_OK_MORE ==
GNUNET_BLOCK_evaluate (GDS_block_context,
GNUNET_BLOCK_TYPE_DHT_HELLO,
bg,
GNUNET_BLOCK_EO_LOCAL_SKIP_CRYPTO,
&my_identity_hash,
NULL, 0,
GDS_my_hello,
hello_size))
{
GDS_NEIGHBOURS_handle_reply (sender,
GNUNET_BLOCK_TYPE_DHT_HELLO,
GNUNET_TIME_relative_to_absolute (hello_expiration),
key,
0,
NULL,
0,
NULL,
GDS_my_hello,
hello_size);
}
else
{
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# FIND PEER requests ignored due to Bloomfilter"),
1,
GNUNET_NO);
}
}
else
{
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# FIND PEER requests ignored due to lack of HELLO"),
1,
GNUNET_NO);
}
/* then, also consider sending a random HELLO from the closest bucket */
if (0 == memcmp (&my_identity_hash,
key,
sizeof (struct GNUNET_HashCode)))
bucket_idx = closest_bucket;
else
bucket_idx = GNUNET_MIN (closest_bucket,
find_bucket (key));
if (bucket_idx == GNUNET_SYSERR)
return;
bucket = &k_buckets[bucket_idx];
if (bucket->peers_size == 0)
return;
choice = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
bucket->peers_size);
peer = bucket->head;
while (choice > 0)
{
GNUNET_assert (NULL != peer);
peer = peer->next;
choice--;
}
choice = bucket->peers_size;
do
{
peer = peer->next;
if (0 == choice--)
return; /* no non-masked peer available */
if (NULL == peer)
peer = bucket->head;
hello = GDS_HELLO_get (peer->id);
} while ( (NULL == hello) ||
(GNUNET_BLOCK_EVALUATION_OK_MORE !=
GNUNET_BLOCK_evaluate (GDS_block_context,
GNUNET_BLOCK_TYPE_DHT_HELLO,
bg,
GNUNET_BLOCK_EO_LOCAL_SKIP_CRYPTO,
&peer->phash,
NULL, 0,
hello,
(hello_size = GNUNET_HELLO_size (hello)))) );
GDS_NEIGHBOURS_handle_reply (sender,
GNUNET_BLOCK_TYPE_DHT_HELLO,
GNUNET_TIME_relative_to_absolute
(GNUNET_CONSTANTS_HELLO_ADDRESS_EXPIRATION),
key,
0,
NULL,
0,
NULL,
hello,
hello_size);
}
/**
* Handle a result from local datacache for a GET operation.
*
* @param cls the `struct PeerInfo` for which this is a reply
* @param type type of the block
* @param expiration_time when does the content expire
* @param key key for the content
* @param put_path_length number of entries in @a put_path
* @param put_path peers the original PUT traversed (if tracked)
* @param get_path_length number of entries in @a get_path
* @param get_path peers this reply has traversed so far (if tracked)
* @param data payload of the reply
* @param data_size number of bytes in @a data
*/
static void
handle_local_result (void *cls,
enum GNUNET_BLOCK_Type type,
struct GNUNET_TIME_Absolute expiration_time,
const struct GNUNET_HashCode *key,
unsigned int put_path_length,
const struct GNUNET_PeerIdentity *put_path,
unsigned int get_path_length,
const struct GNUNET_PeerIdentity *get_path,
const void *data,
size_t data_size)
{
struct PeerInfo *peer = cls;
char *pp;
pp = GNUNET_STRINGS_pp2s (put_path,
put_path_length);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Found local result for %s (PP: %s)\n",
GNUNET_h2s (key),
pp);
GNUNET_free (pp);
GDS_NEIGHBOURS_handle_reply (peer->id,
type,
expiration_time,
key,
put_path_length, put_path,
get_path_length, get_path,
data, data_size);
}
/**
* Check validity of p2p get request.
*
* @param cls closure with the `struct PeerInfo` of the sender
* @param get the message
* @return #GNUNET_OK if the message is well-formed
*/
static int
check_dht_p2p_get (void *cls,
const struct PeerGetMessage *get)
{
uint32_t xquery_size;
uint16_t msize;
msize = ntohs (get->header.size);
xquery_size = ntohl (get->xquery_size);
if (msize < sizeof (struct PeerGetMessage) + xquery_size)
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Core handler for p2p get requests.
*
* @param cls closure with the `struct PeerInfo` of the sender
* @param get the message
*/
static void
handle_dht_p2p_get (void *cls,
const struct PeerGetMessage *get)
{
struct PeerInfo *peer = cls;
uint32_t xquery_size;
size_t reply_bf_size;
uint16_t msize;
enum GNUNET_BLOCK_Type type;
enum GNUNET_DHT_RouteOption options;
enum GNUNET_BLOCK_EvaluationResult eval;
struct GNUNET_BLOCK_Group *bg;
struct GNUNET_CONTAINER_BloomFilter *peer_bf;
const char *xquery;
int forwarded;
/* parse and validate message */
msize = ntohs (get->header.size);
xquery_size = ntohl (get->xquery_size);
reply_bf_size = msize - (sizeof (struct PeerGetMessage) + xquery_size);
type = ntohl (get->type);
options = ntohl (get->options);
xquery = (const char *) &get[1];
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# P2P GET requests received"),
1,
GNUNET_NO);
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# P2P GET bytes received"),
msize,
GNUNET_NO);
if (GNUNET_YES == log_route_details_stderr)
{
char *tmp;
tmp = GNUNET_strdup (GNUNET_i2s (&my_identity));
LOG_TRAFFIC (GNUNET_ERROR_TYPE_DEBUG,
"R5N GET %s: %s->%s (%u, %u=>%u) xq: %.*s\n",
GNUNET_h2s (&get->key),
GNUNET_i2s (peer->id),
tmp,
ntohl(get->hop_count),
GNUNET_CRYPTO_hash_matching_bits (&peer->phash,
&get->key),
GNUNET_CRYPTO_hash_matching_bits (&my_identity_hash,
&get->key),
ntohl(get->xquery_size),
xquery);
GNUNET_free (tmp);
}
eval
= GNUNET_BLOCK_evaluate (GDS_block_context,
type,
NULL,
GNUNET_BLOCK_EO_NONE,
&get->key,
xquery,
xquery_size,
NULL,
0);
if (eval != GNUNET_BLOCK_EVALUATION_REQUEST_VALID)
{
/* request invalid or block type not supported */
GNUNET_break_op (eval == GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED);
return;
}
peer_bf = GNUNET_CONTAINER_bloomfilter_init (get->bloomfilter,
DHT_BLOOM_SIZE,
GNUNET_CONSTANTS_BLOOMFILTER_K);
GNUNET_break_op (GNUNET_YES ==
GNUNET_CONTAINER_bloomfilter_test (peer_bf,
&peer->phash));
bg = GNUNET_BLOCK_group_create (GDS_block_context,
type,
get->bf_mutator,
&xquery[xquery_size],
reply_bf_size,
"filter-size",
reply_bf_size,
NULL);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"GET for %s at %s after %u hops\n",
GNUNET_h2s (&get->key),
GNUNET_i2s (&my_identity),
(unsigned int) ntohl (get->hop_count));
/* local lookup (this may update the reply_bf) */
if ((0 != (options & GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE)) ||
(GDS_am_closest_peer (&get->key,
peer_bf)))
{
if ((0 != (options & GNUNET_DHT_RO_FIND_PEER)))
{
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# P2P FIND PEER requests processed"),
1,
GNUNET_NO);
handle_find_peer (peer->id,
&get->key,
bg);
}
else
{
eval = GDS_DATACACHE_handle_get (&get->key,
type,
xquery,
xquery_size,
bg,
&handle_local_result,
peer);
}
}
else
{
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# P2P GET requests ONLY routed"),
1,
GNUNET_NO);
}
/* remember request for routing replies */
GDS_ROUTING_add (peer->id,
type,
bg, /* bg now owned by routing, but valid at least until end of this function! */
options,
&get->key,
xquery,
xquery_size);
/* P2P forwarding */
forwarded = GNUNET_NO;
if (eval != GNUNET_BLOCK_EVALUATION_OK_LAST)
forwarded = GDS_NEIGHBOURS_handle_get (type,
options,
ntohl (get->desired_replication_level),
ntohl (get->hop_count),
&get->key,
xquery,
xquery_size,
bg,
peer_bf);
GDS_CLIENTS_process_get (options
| (GNUNET_OK == forwarded)
? GNUNET_DHT_RO_LAST_HOP : 0,
type,
ntohl (get->hop_count),
ntohl (get->desired_replication_level),
0,
NULL,
&get->key);
/* clean up; note that 'bg' is owned by routing now! */
GNUNET_CONTAINER_bloomfilter_free (peer_bf);
}
/**
* Check validity of p2p result message.
*
* @param cls closure
* @param message message
* @return #GNUNET_YES if the message is well-formed
*/
static int
check_dht_p2p_result (void *cls,
const struct PeerResultMessage *prm)
{
uint32_t get_path_length;
uint32_t put_path_length;
uint16_t msize;
msize = ntohs (prm->header.size);
put_path_length = ntohl (prm->put_path_length);
get_path_length = ntohl (prm->get_path_length);
if ((msize <
sizeof (struct PeerResultMessage) + (get_path_length +
put_path_length) *
sizeof (struct GNUNET_PeerIdentity)) ||
(get_path_length >
GNUNET_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
(put_path_length >
GNUNET_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Process a reply, after the @a get_path has been updated.
*
* @param expiration_time when does the reply expire
* @param key key matching the query
* @param get_path_length number of entries in @a get_path
* @param get_path path the reply has taken
* @param put_path_length number of entries in @a put_path
* @param put_path path the PUT has taken
* @param type type of the block
* @param data_size number of bytes in @a data
* @param data payload of the reply
*/
static void
process_reply_with_path (struct GNUNET_TIME_Absolute expiration_time,
const struct GNUNET_HashCode *key,
unsigned int get_path_length,
const struct GNUNET_PeerIdentity *get_path,
unsigned int put_path_length,
const struct GNUNET_PeerIdentity *put_path,
enum GNUNET_BLOCK_Type type,
size_t data_size,
const void *data)
{
/* forward to local clients */
GDS_CLIENTS_handle_reply (expiration_time,
key,
get_path_length,
get_path,
put_path_length,
put_path,
type,
data_size,
data);
GDS_CLIENTS_process_get_resp (type,
get_path,
get_path_length,
put_path,
put_path_length,
expiration_time,
key,
data,
data_size);
if (GNUNET_YES == cache_results)
{
struct GNUNET_PeerIdentity xput_path[get_path_length + 1 + put_path_length];
GNUNET_memcpy (xput_path,
put_path,
put_path_length * sizeof (struct GNUNET_PeerIdentity));
GNUNET_memcpy (&xput_path[put_path_length],
get_path,
get_path_length * sizeof (struct GNUNET_PeerIdentity));
GDS_DATACACHE_handle_put (expiration_time,
key,
get_path_length + put_path_length,
xput_path,
type,
data_size,
data);
}
/* forward to other peers */
GDS_ROUTING_process (type,
expiration_time,
key,
put_path_length,
put_path,
get_path_length,
get_path,
data,
data_size);
}
/**
* Core handler for p2p result messages.
*
* @param cls closure
* @param message message
*/
static void
handle_dht_p2p_result (void *cls,
const struct PeerResultMessage *prm)
{
struct PeerInfo *peer = cls;
const struct GNUNET_PeerIdentity *put_path;
const struct GNUNET_PeerIdentity *get_path;
const void *data;
uint32_t get_path_length;
uint32_t put_path_length;
uint16_t msize;
size_t data_size;
enum GNUNET_BLOCK_Type type;
/* parse and validate message */
msize = ntohs (prm->header.size);
put_path_length = ntohl (prm->put_path_length);
get_path_length = ntohl (prm->get_path_length);
put_path = (const struct GNUNET_PeerIdentity *) &prm[1];
get_path = &put_path[put_path_length];
type = ntohl (prm->type);
data = (const void *) &get_path[get_path_length];
data_size = msize - (sizeof (struct PeerResultMessage) +
(get_path_length +
put_path_length) * sizeof (struct GNUNET_PeerIdentity));
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# P2P RESULTS received"),
1,
GNUNET_NO);
GNUNET_STATISTICS_update (GDS_stats,
gettext_noop ("# P2P RESULT bytes received"),
msize,
GNUNET_NO);
if (GNUNET_YES == log_route_details_stderr)
{
char *tmp;
char *pp;
char *gp;
gp = GNUNET_STRINGS_pp2s (get_path,
get_path_length);
pp = GNUNET_STRINGS_pp2s (put_path,
put_path_length);
tmp = GNUNET_strdup (GNUNET_i2s (&my_identity));
LOG_TRAFFIC (GNUNET_ERROR_TYPE_DEBUG,
"R5N RESULT %s: %s->%s (GP: %s, PP: %s)\n",
GNUNET_h2s (&prm->key),
GNUNET_i2s (peer->id),
tmp,
gp,
pp);
GNUNET_free (gp);
GNUNET_free (pp);
GNUNET_free (tmp);
}
/* if we got a HELLO, consider it for our own routing table */
if (GNUNET_BLOCK_TYPE_DHT_HELLO == type)
{
const struct GNUNET_MessageHeader *h;
struct GNUNET_PeerIdentity pid;
/* Should be a HELLO, validate and consider using it! */
if (data_size < sizeof (struct GNUNET_HELLO_Message))
{
GNUNET_break_op (0);
return;
}
h = data;
if (data_size != ntohs (h->size))
{
GNUNET_break_op (0);
return;
}
if (GNUNET_OK !=
GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) h,
&pid))
{
GNUNET_break_op (0);
return;
}
if ( (GNUNET_YES != disable_try_connect) &&
(0 != memcmp (&my_identity,
&pid,
sizeof (struct GNUNET_PeerIdentity))) )
try_connect (&pid,
h);
}
/* First, check if 'peer' is already on the path, and if
so, truncate it instead of expanding. */
for (unsigned int i=0;i<=get_path_length;i++)
if (0 == memcmp (&get_path[i],
peer->id,
sizeof (struct GNUNET_PeerIdentity)))
{
process_reply_with_path (GNUNET_TIME_absolute_ntoh (prm->expiration_time),
&prm->key,
i,
get_path,
put_path_length,
put_path,
type,
data_size,
data);
return;
}
/* Need to append 'peer' to 'get_path' (normal case) */
{
struct GNUNET_PeerIdentity xget_path[get_path_length + 1];
GNUNET_memcpy (xget_path,
get_path,
get_path_length * sizeof (struct GNUNET_PeerIdentity));
xget_path[get_path_length] = *peer->id;
process_reply_with_path (GNUNET_TIME_absolute_ntoh (prm->expiration_time),
&prm->key,
get_path_length + 1,
xget_path,
put_path_length,
put_path,
type,
data_size,
data);
}
}
/**
* Initialize neighbours subsystem.
*
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
int
GDS_NEIGHBOURS_init ()
{
struct GNUNET_MQ_MessageHandler core_handlers[] = {
GNUNET_MQ_hd_var_size (dht_p2p_get,
GNUNET_MESSAGE_TYPE_DHT_P2P_GET,
struct PeerGetMessage,
NULL),
GNUNET_MQ_hd_var_size (dht_p2p_put,
GNUNET_MESSAGE_TYPE_DHT_P2P_PUT,
struct PeerPutMessage,
NULL),
GNUNET_MQ_hd_var_size (dht_p2p_result,
GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT,
struct PeerResultMessage,
NULL),
GNUNET_MQ_handler_end ()
};
unsigned long long temp_config_num;
disable_try_connect
= GNUNET_CONFIGURATION_get_value_yesno (GDS_cfg,
"DHT",
"DISABLE_TRY_CONNECT");
if (GNUNET_OK ==
GNUNET_CONFIGURATION_get_value_number (GDS_cfg,
"DHT",
"bucket_size",
&temp_config_num))
bucket_size = (unsigned int) temp_config_num;
cache_results
= GNUNET_CONFIGURATION_get_value_yesno (GDS_cfg,
"DHT",
"CACHE_RESULTS");
log_route_details_stderr =
(NULL != getenv("GNUNET_DHT_ROUTE_DEBUG")) ? GNUNET_YES : GNUNET_NO;
ats_ch = GNUNET_ATS_connectivity_init (GDS_cfg);
core_api = GNUNET_CORE_connect (GDS_cfg,
NULL,
&core_init,
&handle_core_connect,
&handle_core_disconnect,
core_handlers);
if (NULL == core_api)
return GNUNET_SYSERR;
all_connected_peers = GNUNET_CONTAINER_multipeermap_create (256,
GNUNET_YES);
all_desired_peers = GNUNET_CONTAINER_multipeermap_create (256,
GNUNET_NO);
return GNUNET_OK;
}
/**
* Shutdown neighbours subsystem.
*/
void
GDS_NEIGHBOURS_done ()
{
if (NULL == core_api)
return;
GNUNET_CORE_disconnect (core_api);
core_api = NULL;
GNUNET_assert (0 ==
GNUNET_CONTAINER_multipeermap_size (all_connected_peers));
GNUNET_CONTAINER_multipeermap_destroy (all_connected_peers);
all_connected_peers = NULL;
GNUNET_CONTAINER_multipeermap_iterate (all_desired_peers,
&free_connect_info,
NULL);
GNUNET_CONTAINER_multipeermap_destroy (all_desired_peers);
all_desired_peers = NULL;
GNUNET_ATS_connectivity_done (ats_ch);
ats_ch = NULL;
GNUNET_assert (NULL == find_peer_task);
}
/**
* Get the ID of the local node.
*
* @return identity of the local node
*/
struct GNUNET_PeerIdentity *
GDS_NEIGHBOURS_get_id ()
{
return &my_identity;
}
/* end of gnunet-service-dht_neighbours.c */