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freeswitch/libs/libks/src/dht/ks_dht_bucket.c

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/*
* Copyright (c) 2016, FreeSWITCH Solutions LLC
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of the original author; nor the names of any contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma GCC optimize ("O0")
#include "ks_dht.h"
/* change for testing */
#define KS_DHT_BUCKETSIZE 20
#define KS_DHTRT_INACTIVETIME (10*60)
#define KS_DHTRT_EXPIREDTIME (15*60)
#define KS_DHTRT_MAXPING 3
#define KS_DHTRT_PROCESSTABLE_INTERVAL (5*60)
#define KS_DHTRT_PROCESSTABLE_SHORTINTERVAL (120)
#define KS_DHTRT_RECYCLE_NODE_THRESHOLD 100
/* peer flags */
#define DHTPEER_DUBIOUS 0
#define DHTPEER_EXPIRED 1
#define DHTPEER_ACTIVE 2
typedef uint8_t ks_dhtrt_nodeid_t[KS_DHT_NODEID_SIZE];
/* internal structures */
typedef struct ks_dhtrt_bucket_entry_s {
ks_time_t tyme;
uint8_t id[KS_DHT_NODEID_SIZE];
ks_dht_node_t *gptr; /* ptr to peer */
enum ks_dht_nodetype_t type;
enum ks_afflags_t family;
uint8_t inuse;
uint8_t outstanding_pings;
uint8_t flags; /* active, suspect, expired */
uint8_t touched; /* did we ever get a touch */
} ks_dhtrt_bucket_entry_t;
typedef struct ks_dhtrt_bucket_s {
ks_dhtrt_bucket_entry_t entries[KS_DHT_BUCKETSIZE];
uint8_t count;
uint8_t expired_count;
ks_rwl_t *lock; /* lock for safe traversal of the entry array */
} ks_dhtrt_bucket_t;
#define BHF_LEFT 0x80
typedef struct ks_dhtrt_bucket_header_s {
struct ks_dhtrt_bucket_header_s * parent;
struct ks_dhtrt_bucket_header_s * left;
struct ks_dhtrt_bucket_header_s * right;
ks_dhtrt_bucket_t * bucket;
ks_time_t tyme; /* last processed time */
unsigned char mask[KS_DHT_NODEID_SIZE]; /* node id mask */
unsigned char flags;
} ks_dhtrt_bucket_header_t;
typedef struct ks_dhtrt_deletednode_s {
ks_dht_node_t* node;
struct ks_dhtrt_deletednode_s *next;
} ks_dhtrt_deletednode_t;
typedef struct ks_dhtrt_internal_s {
uint8_t localid[KS_DHT_NODEID_SIZE];
ks_dhtrt_bucket_header_t *buckets; /* root bucketheader */
ks_dht_t *dht;
ks_thread_pool_t *tpool;
ks_rwl_t *lock; /* lock for safe traversal of the tree */
ks_time_t last_process_table;
ks_time_t next_process_table_delta;
ks_mutex_t *deleted_node_lock;
ks_dhtrt_deletednode_t *deleted_node;
ks_dhtrt_deletednode_t *free_node_ex;
uint32_t deleted_count;
} ks_dhtrt_internal_t;
typedef struct ks_dhtrt_xort_s {
unsigned int ix; /* index of bucket array */
unsigned char xor[KS_DHT_NODEID_SIZE]; /* corresponding xor value */
unsigned int nextix;
} ks_dhtrt_xort_t;
typedef struct ks_dhtrt_sortedxors_s {
ks_dhtrt_bucket_header_t *bheader;
ks_dhtrt_xort_t xort[KS_DHT_BUCKETSIZE];
unsigned char hixor[KS_DHT_NODEID_SIZE];
unsigned int startix;
unsigned int count;
struct ks_dhtrt_sortedxors_s* next;
} ks_dhtrt_sortedxors_t;
/* --- static functions ---- */
static
ks_dhtrt_bucket_header_t *ks_dhtrt_create_bucketheader(
ks_pool_t *pool,
ks_dhtrt_bucket_header_t *parent,
unsigned char *mask);
static
ks_dhtrt_bucket_t *ks_dhtrt_create_bucket(ks_pool_t *pool);
static
ks_dhtrt_bucket_header_t *ks_dhtrt_find_bucketheader(ks_dhtrt_routetable_t *table, ks_dhtrt_nodeid_t id);
static
ks_dhtrt_bucket_header_t *ks_dhtrt_find_relatedbucketheader(ks_dhtrt_bucket_header_t *header, ks_dhtrt_nodeid_t id);
static
ks_dhtrt_bucket_entry_t *ks_dhtrt_find_bucketentry(ks_dhtrt_bucket_header_t *header, ks_dhtrt_nodeid_t id);
static
void ks_dhtrt_split_bucket(ks_dhtrt_bucket_header_t *original, ks_dhtrt_bucket_header_t *left, ks_dhtrt_bucket_header_t *right);
static
ks_dht_node_t *ks_dhtrt_find_nodeid(ks_dhtrt_bucket_t *bucket, ks_dhtrt_nodeid_t nodeid);
static
void ks_dhtrt_shiftright(uint8_t *id);
static
void ks_dhtrt_shiftleft(uint8_t *id);
static
void ks_dhtrt_xor(const uint8_t *id1, const uint8_t *id2, uint8_t *xor);
static
int ks_dhtrt_ismasked(const uint8_t *id1, const uint8_t *mask);
static
void ks_dhtrt_queue_node_fordelete(ks_dhtrt_routetable_t *table, ks_dht_node_t* node);
static
void ks_dhtrt_process_deleted(ks_dhtrt_routetable_t *table);
static
ks_dht_node_t *ks_dhtrt_make_node(ks_dhtrt_routetable_t *table);
static
ks_status_t ks_dhtrt_insert_node(ks_dhtrt_routetable_t *table, ks_dht_node_t *node);
static
ks_status_t ks_dhtrt_insert_id(ks_dhtrt_bucket_t *bucket, ks_dht_node_t *node);
static
ks_status_t ks_dhtrt_delete_id(ks_dhtrt_bucket_t *bucket, ks_dhtrt_nodeid_t id);
static
char *ks_dhtrt_printableid(uint8_t *id, char *buffer);
static
unsigned char ks_dhtrt_isactive(ks_dhtrt_bucket_entry_t *entry);
static
uint8_t ks_dhtrt_findclosest_locked_nodes(ks_dhtrt_routetable_t *table, ks_dhtrt_querynodes_t *query);
static
uint8_t ks_dhtrt_load_query(ks_dhtrt_querynodes_t *query, ks_dhtrt_sortedxors_t *xort);
static
uint8_t ks_dhtrt_findclosest_bucketnodes(unsigned char *nodeid,
enum ks_dht_nodetype_t type,
enum ks_afflags_t family,
ks_dhtrt_bucket_header_t *header,
ks_dhtrt_sortedxors_t *xors,
unsigned char *hixor,
unsigned int max);
static
void ks_dhtrt_ping(ks_dhtrt_internal_t *table, ks_dhtrt_bucket_entry_t *entry);
/* debugging */
#define KS_DHT_DEBUGPRINTF_
/* very verbose */
/* # define KS_DHT_DEBUGPRINTFX_ */
/* debug locking */
#define KS_DHT_DEBUGLOCKPRINTF_
KS_DECLARE(ks_status_t) ks_dhtrt_initroute(ks_dhtrt_routetable_t **tableP,
ks_dht_t *dht,
ks_pool_t *pool,
ks_thread_pool_t* tpool)
{
(void)ks_dhtrt_find_relatedbucketheader;
unsigned char initmask[KS_DHT_NODEID_SIZE];
memset(initmask, 0xff, sizeof(initmask));
ks_dhtrt_routetable_t *table = ks_pool_alloc(pool, sizeof(ks_dhtrt_routetable_t));
ks_dhtrt_internal_t *internal = ks_pool_alloc(pool, sizeof(ks_dhtrt_internal_t));
ks_rwl_create(&internal->lock, pool);
internal->tpool = tpool;
internal->dht = dht;
internal->next_process_table_delta = KS_DHTRT_PROCESSTABLE_INTERVAL;
ks_mutex_create(&internal->deleted_node_lock, KS_MUTEX_FLAG_DEFAULT, pool);
table->internal = internal;
/* initialize root bucket */
ks_dhtrt_bucket_header_t *initial_header = ks_dhtrt_create_bucketheader(pool, 0, initmask);
initial_header->flags = BHF_LEFT; /* fake left to allow splitting */
internal->buckets = initial_header;
initial_header->bucket = ks_dhtrt_create_bucket(pool);
table->pool = pool;
*tableP = table;
return KS_STATUS_SUCCESS;
}
KS_DECLARE(void) ks_dhtrt_deinitroute(ks_dhtrt_routetable_t **table)
{
/* @todo*/
ks_pool_t *pool = (*table)->pool;
ks_pool_free(pool, &(*table));
return;
}
KS_DECLARE(ks_status_t) ks_dhtrt_create_node( ks_dhtrt_routetable_t *table,
ks_dht_nodeid_t nodeid,
enum ks_dht_nodetype_t type,
char *ip,
unsigned short port,
ks_dht_node_t **node)
{
ks_dht_node_t *tnode;
ks_dhtrt_internal_t* internal = table->internal;
ks_rwl_read_lock(internal->lock); /* grab write lock and insert */
ks_dhtrt_bucket_header_t *header = ks_dhtrt_find_bucketheader(table, nodeid.id);
assert(header != NULL); /* should always find a header */
ks_dhtrt_bucket_entry_t *bentry = ks_dhtrt_find_bucketentry(header, nodeid.id);
if (bentry != 0) {
bentry->tyme = ks_time_now_sec();
if (bentry->touched) {
bentry->flags = DHTPEER_ACTIVE;
}
tnode = bentry->gptr;
ks_rwl_read_lock( tnode->reflock);
ks_rwl_read_unlock(internal->lock);
(*node) = tnode;
return KS_STATUS_SUCCESS;
}
ks_rwl_read_unlock(internal->lock);
tnode = ks_dhtrt_make_node(table);
tnode->table = table;
for (int i = 0; i < 5; ++i) {
if (ip[i] == ':') {
tnode->family = AF_INET6; break;
} else if (ip[i] == '.') {
tnode->family = AF_INET; break;
}
}
memcpy(tnode->nodeid.id, nodeid.id, KS_DHT_NODEID_SIZE);
tnode->type = type;
if (( ks_addr_set(&tnode->addr, ip, port, tnode->family) != KS_STATUS_SUCCESS) ||
( ks_rwl_create(&tnode->reflock, table->pool) != KS_STATUS_SUCCESS)) {
ks_pool_free(table->pool, &tnode);
ks_rwl_read_unlock(internal->lock);
return KS_STATUS_FAIL;
}
ks_status_t s = ks_dhtrt_insert_node(table, tnode);
if (tnode && s == KS_STATUS_SUCCESS) {
ks_rwl_read_lock( tnode->reflock);
}
(*node) = tnode;
return s;
}
KS_DECLARE(ks_status_t) ks_dhtrt_delete_node(ks_dhtrt_routetable_t *table, ks_dht_node_t *node)
{
ks_status_t s = KS_STATUS_FAIL;
ks_dhtrt_internal_t* internal = table->internal;
ks_rwl_read_lock(internal->lock); /* grab read lock */
ks_dhtrt_bucket_header_t *header = ks_dhtrt_find_bucketheader(table, node->nodeid.id);
if (header != 0) {
ks_dhtrt_bucket_t *bucket = header->bucket;
if (bucket != 0) { /* we found a bucket*/
#ifdef KS_DHT_DEBUGLOCKPRINTF_
char buf[100];
ks_log(KS_LOG_DEBUG, "Delete node: LOCKING bucket %s\n", ks_dhtrt_printableid(header->mask, buf));
#endif
ks_rwl_write_lock(bucket->lock);
s = ks_dhtrt_delete_id(bucket, node->nodeid.id);
#ifdef KS_DHT_DEBUGLOCKPRINTF_
ks_log(KS_LOG_DEBUG, "Delete node: UNLOCKING bucket %s\n", ks_dhtrt_printableid(header->mask, buf));
#endif
ks_rwl_write_unlock(bucket->lock);
}
}
ks_rwl_read_unlock(internal->lock); /* release write lock */
/* at this point no subsequent find/query will return the node */
ks_dhtrt_queue_node_fordelete(table, node);
return s;
}
static
ks_status_t ks_dhtrt_insert_node(ks_dhtrt_routetable_t *table, ks_dht_node_t *node)
{
ks_dhtrt_internal_t* internal = table->internal;
ks_dhtrt_bucket_t *bucket = 0;
int insanity = 0;
ks_rwl_write_lock(internal->lock);
ks_dhtrt_bucket_header_t *header = ks_dhtrt_find_bucketheader(table, node->nodeid.id);
assert(header != NULL); /* should always find a header */
bucket = header->bucket;
if (bucket == 0) {
ks_rwl_write_unlock(internal->lock);
return KS_STATUS_FAIL; /* we were not able to find a bucket*/
}
#ifdef KS_DHT_DEBUGLOCKPRINTF_
char buf[100];
ks_log(KS_LOG_DEBUG, "Insert node: LOCKING bucket %s\n", ks_dhtrt_printableid(header->mask, buf));
//fflush(stdout);
#endif
ks_rwl_write_lock(bucket->lock);
while (bucket->count == KS_DHT_BUCKETSIZE) {
if (insanity > 3200) assert(insanity < 3200);
/* first - seek a stale entry to eject */
if (bucket->expired_count) {
ks_status_t s = ks_dhtrt_insert_id(bucket, node);
if (s == KS_STATUS_SUCCESS) {
#ifdef KS_DHT_DEBUGLOCKPRINTF_
ks_log(KS_LOG_DEBUG, "insert node: UNLOCKING bucket %s\n", ks_dhtrt_printableid(header->mask, buf));
//fflush(stdout);
#endif
ks_rwl_write_unlock(bucket->lock);
ks_rwl_write_unlock(internal->lock);
return KS_STATUS_SUCCESS;
}
}
/*
todo: attempting a ping at at this point would require us
to suspend this process ... tricky...assume right now we will go ahead and
eject. Possibly add to a list to recheck
*/
if ( !(header->flags & BHF_LEFT) ) { /* only the left handside node can be split */
#ifdef KS_DHT_DEBUGPRINTF_
char bufx[100];
ks_log(KS_LOG_DEBUG, "nodeid %s was not inserted\n", ks_dhtrt_printableid(node->nodeid.id, bufx));
#endif
#ifdef KS_DHT_DEBUGLOCKPRINTF_
ks_log(KS_LOG_DEBUG, "Insert node: UNLOCKING bucket %s\n", ks_dhtrt_printableid(header->mask, buf));
//fflush(stdout);
#endif
ks_rwl_write_unlock(bucket->lock);
ks_rwl_write_unlock(internal->lock);
return KS_STATUS_FAIL;
}
/* bucket must be split */
/* work out new mask */
unsigned char newmask[KS_DHT_NODEID_SIZE];
memcpy(newmask, header->mask, KS_DHT_NODEID_SIZE);
if (newmask[KS_DHT_NODEID_SIZE-1] == 0) { /* no more bits to shift - is this possible */
#ifdef KS_DHT_DEBUGPRINTF_
char bufx[100];
ks_log(KS_LOG_DEBUG," nodeid %s was not inserted\n", ks_dhtrt_printableid(node->nodeid.id, bufx));
#endif
#ifdef KS_DHT_DEBUGLOCKPRINTF_
ks_log(KS_LOG_DEBUG, "Insert node: UNLOCKING bucket %s\n", ks_dhtrt_printableid(header->mask, buf));
//fflush(stdout);
#endif
ks_rwl_write_unlock(bucket->lock);
ks_rwl_write_unlock(internal->lock);
return KS_STATUS_FAIL;
}
/* shift right x bits : todo 1 bit for the moment */
ks_dhtrt_shiftright(newmask);
/* create the new bucket structures */
ks_dhtrt_bucket_header_t *newleft = ks_dhtrt_create_bucketheader(table->pool, header, newmask);
newleft->bucket = ks_dhtrt_create_bucket(table->pool);
newleft->flags = BHF_LEFT; /* flag as left hand side - therefore splitable */
ks_dhtrt_bucket_header_t *newright = ks_dhtrt_create_bucketheader(table->pool, header, header->mask);
ks_dhtrt_split_bucket(header, newleft, newright);
/* ok now we need to try again to see if the bucket has capacity */
/* which bucket do care about */
if (ks_dhtrt_ismasked(node->nodeid.id, newleft->mask)) {
bucket = newleft->bucket;
#ifdef KS_DHT_DEBUGLOCKPRINTF_
ks_log(KS_LOG_DEBUG, "Insert node: UNLOCKING bucket %s\n", ks_dhtrt_printableid(header->right->mask, buf));
ks_log(KS_LOG_DEBUG, "Insert node: LOCKING bucket %s\n", ks_dhtrt_printableid(newleft->mask, buf));
//fflush(stdout);
#endif
ks_rwl_write_lock(bucket->lock); /* lock new bucket */
ks_rwl_write_unlock(header->right->bucket->lock); /* unlock old bucket */
header = newleft;
} else {
bucket = newright->bucket;
/* note: we still hold a lock on the bucket */
header = newright;
}
++insanity;
}
#ifdef KS_DHT_DEBUGPRINTF_
char buffer[100];
ks_log(KS_LOG_DEBUG, "Inserting nodeid %s\n", ks_dhtrt_printableid(node->nodeid.id, buffer));
ks_log(KS_LOG_DEBUG, " ...into bucket %s\n", ks_dhtrt_printableid(header->mask, buffer));
#endif
ks_status_t s = ks_dhtrt_insert_id(bucket, node);
ks_rwl_write_unlock(internal->lock);
#ifdef KS_DHT_DEBUGLOCKPRINTF_
ks_log(KS_LOG_DEBUG, "Insert node: UNLOCKING bucket %s\n",
ks_dhtrt_printableid(header->mask, buf));
//fflush(stdout);
#endif
ks_rwl_write_unlock(bucket->lock);
return s;
}
KS_DECLARE(ks_dht_node_t *) ks_dhtrt_find_node(ks_dhtrt_routetable_t *table, ks_dht_nodeid_t nodeid)
{
ks_dht_node_t* node = NULL;
ks_dhtrt_internal_t* internal = table->internal;
ks_rwl_read_lock(internal->lock); /* grab read lock */
ks_dhtrt_bucket_header_t *header = ks_dhtrt_find_bucketheader(table, nodeid.id);
if (header != 0) {
ks_dhtrt_bucket_t *bucket = header->bucket;
if (bucket != 0) { /* probably a logic error ?*/
#ifdef KS_DHT_DEBUGLOCKPRINTF_
char buf[100];
ks_log(KS_LOG_DEBUG, "Find node: read LOCKING bucket %s\n", ks_dhtrt_printableid(header->mask, buf));
//fflush(stdout);
#endif
ks_rwl_read_lock(bucket->lock);
node = ks_dhtrt_find_nodeid(bucket, nodeid.id);
if (node != NULL) {
ks_rwl_read_lock(node->reflock);
}
#ifdef KS_DHT_DEBUGLOCKPRINTF_
ks_log(KS_LOG_DEBUG, "Find node: read UNLOCKING bucket %s\n", ks_dhtrt_printableid(header->mask, buf));
//fflush(stdout);
#endif
ks_rwl_read_unlock(bucket->lock);
}
}
ks_rwl_read_unlock(internal->lock);
return node;
}
KS_DECLARE(ks_status_t) ks_dhtrt_touch_node(ks_dhtrt_routetable_t *table, ks_dht_nodeid_t nodeid)
{
ks_status_t s = KS_STATUS_FAIL;
ks_dhtrt_internal_t* internal = table->internal;
ks_rwl_read_lock(internal->lock); /* grab read lock */
ks_dhtrt_bucket_header_t *header = ks_dhtrt_find_bucketheader(table, nodeid.id);
if (header != 0 && header->bucket != 0) {
ks_rwl_write_lock(header->bucket->lock);
#ifdef KS_DHT_DEBUGLOCKPRINTF_
char buf[100];
ks_log(KS_LOG_DEBUG, "Touch node: write bucket %s\n", ks_dhtrt_printableid(header->mask, buf));
//fflush(stdout);
#endif
ks_dhtrt_bucket_entry_t *e = ks_dhtrt_find_bucketentry(header, nodeid.id);
if (e != 0) {
e->tyme = ks_time_now_sec();
e->outstanding_pings = 0;
e->touched = 1;
if (e->flags == DHTPEER_EXPIRED) {
--header->bucket->expired_count;
}
e->flags = DHTPEER_ACTIVE;
s = KS_STATUS_SUCCESS;
}
#ifdef KS_DHT_DEBUGLOCKPRINTF_
ks_log(KS_LOG_DEBUG, "Touch node: UNLOCKING bucket %s\n", ks_dhtrt_printableid(header->mask, buf));
//fflush(stdout);
#endif
ks_rwl_write_unlock(header->bucket->lock);
}
ks_rwl_read_unlock(internal->lock); /* release read lock */
return s;
}
KS_DECLARE(ks_status_t) ks_dhtrt_expire_node(ks_dhtrt_routetable_t *table, ks_dht_nodeid_t nodeid)
{
ks_status_t s = KS_STATUS_FAIL;
ks_dhtrt_internal_t *internal = table->internal;
ks_rwl_read_lock(internal->lock); /* grab read lock */
ks_dhtrt_bucket_header_t *header = ks_dhtrt_find_bucketheader(table, nodeid.id);
if (header != 0 && header->bucket != 0) {
ks_rwl_write_lock(header->bucket->lock);
ks_dhtrt_bucket_entry_t *e = ks_dhtrt_find_bucketentry(header, nodeid.id);
if (e != 0) {
e->flags = DHTPEER_EXPIRED;
s = KS_STATUS_SUCCESS;
}
ks_rwl_write_unlock(header->bucket->lock);
}
ks_rwl_read_unlock(internal->lock); /* release read lock */
return s;
}
KS_DECLARE(uint8_t) ks_dhtrt_findclosest_nodes(ks_dhtrt_routetable_t *table, ks_dhtrt_querynodes_t *query)
{
uint8_t count = 0;
ks_dhtrt_internal_t *internal = table->internal;
ks_rwl_read_lock(internal->lock); /* grab read lock */
count = ks_dhtrt_findclosest_locked_nodes(table, query);
ks_rwl_read_unlock(internal->lock); /* release read lock */
return count;
}
static
uint8_t ks_dhtrt_findclosest_locked_nodes(ks_dhtrt_routetable_t *table, ks_dhtrt_querynodes_t *query)
{
uint8_t max = query->max;
uint8_t total = 0;
uint8_t cnt;
if (max == 0) return 0; /* sanity checks */
if (max > KS_DHTRT_MAXQUERYSIZE) { /* enforce the maximum */
max = KS_DHTRT_MAXQUERYSIZE;
query->max = KS_DHTRT_MAXQUERYSIZE;
}
query->count = 0;
ks_dhtrt_bucket_header_t *header = ks_dhtrt_find_bucketheader(table, query->nodeid.id);
#ifdef KS_DHT_DEBUGPRINTF_
char buffer[100];
ks_log(KS_LOG_DEBUG, "Finding %d closest nodes for nodeid %s\n", max, ks_dhtrt_printableid(query->nodeid.id, buffer));
ks_log(KS_LOG_DEBUG, " ...starting at mask: %s\n", ks_dhtrt_printableid(header->mask, buffer));
#endif
ks_dhtrt_sortedxors_t xort0;
memset(&xort0, 0 , sizeof(xort0));
ks_dhtrt_nodeid_t initid;
memset(initid, 0xff, KS_DHT_NODEID_SIZE);
xort0.bheader = header;
/* step 1 - look at immediate bucket */
/* --------------------------------- */
cnt = ks_dhtrt_findclosest_bucketnodes(query->nodeid.id, query->type, query->family, header, &xort0, initid ,max);
max -= cnt;
total += cnt;
#ifdef KS_DHT_DEBUGPRINTF_
ks_log(KS_LOG_DEBUG, "Bucket %s yielded %d nodes; total=%d\n", buffer, cnt, total);
#endif
if (total >= query->max ||
!header->parent ) { /* is query answered ? */
return ks_dhtrt_load_query(query, &xort0);
}
/* step2 - look at sibling */
/* ----------------------- */
ks_dhtrt_sortedxors_t xort1;
xort0.next = &xort1;
memset(&xort1, 0 , sizeof(xort1));
memcpy(initid, &xort0.hixor, KS_DHT_NODEID_SIZE);
ks_dhtrt_bucket_header_t *parent = header->parent;
if (header == parent->left) {
xort1.bheader = header = parent->right;
} else {
if (!parent->left->bucket) { /* left hand might no have a bucket - if so choose left->right */
xort1.bheader = header = parent->left->right;
} else {
xort1.bheader = header = parent->left;
}
}
cnt = ks_dhtrt_findclosest_bucketnodes(query->nodeid.id, query->type, query->family, header, &xort1, initid ,max);
max -= cnt;
total += cnt;
#ifdef KS_DHT_DEBUGPRINTF_
ks_log(KS_LOG_DEBUG," stage2: sibling bucket header %s yielded %d nodes, total=%d\n",
ks_dhtrt_printableid(header->mask, buffer), cnt, total);
#endif
if (total >= query->max) { /* is query answered ? */
return ks_dhtrt_load_query(query, &xort0);
}
/* step3 and beyond ... work left and right until the count is satisfied */
/* ---------------------------------------------------------------------- */
memcpy(initid, &xort0.hixor, KS_DHT_NODEID_SIZE);
unsigned char leftid[KS_DHT_NODEID_SIZE];
unsigned char rightid[KS_DHT_NODEID_SIZE];
memcpy(leftid, xort0.bheader->mask, KS_DHT_NODEID_SIZE);
memcpy(rightid, xort1.bheader->mask, KS_DHT_NODEID_SIZE);
int insanity = 0;
ks_dhtrt_bucket_header_t *lheader;
ks_dhtrt_bucket_header_t *rheader;
ks_dhtrt_sortedxors_t *prev = &xort1;
ks_dhtrt_sortedxors_t *tofree = 0;
ks_dhtrt_sortedxors_t *xortn;
ks_dhtrt_sortedxors_t *xortn1;
do {
lheader = 0;
rheader = 0;
xortn = 0;
xortn1 = 0;
if (leftid[0] != 0xff) {
ks_dhtrt_shiftleft(leftid);
lheader = ks_dhtrt_find_bucketheader(table, leftid);
if (lheader) {
xortn = ks_pool_alloc(table->pool, sizeof(ks_dhtrt_sortedxors_t));
if (tofree == 0) tofree = xortn;
prev->next = xortn;
prev = xortn;
cnt += ks_dhtrt_findclosest_bucketnodes(query->nodeid.id, query->type, query->family,
lheader, xortn, leftid ,max);
max -= cnt;
#ifdef KS_DHT_DEBUGPRINTF_
ks_log(KS_LOG_DEBUG," stage3: seaching left bucket header %s yielded %d nodes, total=%d\n",
ks_dhtrt_printableid(lheader->mask, buffer), cnt, total);
#endif
}
}
if (max > 0 && rightid[KS_DHT_NODEID_SIZE-1] != 0x00) {
ks_dhtrt_shiftright(rightid);
rheader = ks_dhtrt_find_bucketheader(table, rightid);
if (rheader) {
xortn1 = ks_pool_alloc(table->pool, sizeof(ks_dhtrt_sortedxors_t));
prev->next = xortn1;
prev = xortn1;
cnt = ks_dhtrt_findclosest_bucketnodes(query->nodeid.id, query->type, query->family,
rheader, xortn1, rightid , max);
max -= cnt;
#ifdef KS_DHT_DEBUGPRINTF_
ks_log(KS_LOG_DEBUG," stage3: seaching right bucket header %s yielded %d nodes, total=%d\n",
ks_dhtrt_printableid(rheader->mask, buffer), cnt, total);
#endif
}
}
if (!lheader && !rheader) {
break;
}
++insanity;
if (insanity > 159) {
assert(insanity <= 159);
}
} while (max < query->max);
ks_dhtrt_load_query(query, &xort0);
/* free up the xort structs on heap */
while (tofree) {
ks_dhtrt_sortedxors_t *x = tofree->next;
ks_pool_free(table->pool, &tofree);
tofree = x;
}
return query->count;
}
KS_DECLARE(ks_status_t) ks_dhtrt_release_node(ks_dht_node_t* node)
{
return ks_rwl_read_unlock(node->reflock);
}
KS_DECLARE(ks_status_t) ks_dhtrt_release_querynodes(ks_dhtrt_querynodes_t *query)
{
for(int ix=0; ix<query->count; ++ix) {
ks_rwl_read_unlock(query->nodes[ix]->reflock);
}
return KS_STATUS_SUCCESS;
}
KS_DECLARE(void) ks_dhtrt_process_table(ks_dhtrt_routetable_t *table)
{
/* walk the table and update the status of all known knodes */
/* anything that is suspect automatically becomes expired */
/* inactive for 15 minutes, a node becomes quesionable */
/* it should be pinged */
/* if it has not been 'touched' since the last time */
/* give it one more try */
/* inactive again it is considered inactive */
/* */
ks_dhtrt_internal_t *internal = table->internal;
int ping_count = 0;
ks_time_t t0 = ks_time_now_sec();
/*
printf("process_table: %" PRId64 " %" PRId64 "\n", t0 - internal->last_process_table, internal->next_process_table_delta);
*/
if (t0 - internal->last_process_table < internal->next_process_table_delta) {
return;
}
internal->last_process_table = t0;
ks_log(KS_LOG_DEBUG,"process_table in progress\n");
ks_rwl_read_lock(internal->lock); /* grab read lock */
ks_dhtrt_bucket_header_t *header = internal->buckets;
ks_dhtrt_bucket_header_t *stack[KS_DHT_NODEID_SIZE * 8];
int stackix=0;
while (header) {
stack[stackix++] = header;
if (header->bucket) {
ks_dhtrt_bucket_t *b = header->bucket;
if (ks_rwl_try_write_lock(b->lock) == KS_STATUS_SUCCESS) {
#ifdef KS_DHT_DEBUGLOCKPRINTF_
char buf[100];
ks_log(KS_LOG_DEBUG,"process_table: LOCKING bucket %s\n", ks_dhtrt_printableid(header->mask, buf));
#endif
for (int ix=0; ix<KS_DHT_BUCKETSIZE; ++ix) {
ks_dhtrt_bucket_entry_t *e = &b->entries[ix];
if (e->inuse == 1) {
if (e->gptr->type != KS_DHT_LOCAL) { /* 'local' nodes do not get expired */
/* more than n pings outstanding? */
if (e->flags == DHTPEER_DUBIOUS) {
continue;
}
if ( e->flags != DHTPEER_EXPIRED &&
e->outstanding_pings >= KS_DHTRT_MAXPING ) {
#ifdef KS_DHT_DEBUGPRINTF_
ks_log(KS_LOG_DEBUG,"process_table: expiring node %s\n",
ks_dhtrt_printableid(e->id, buf));
#endif
e->flags = DHTPEER_EXPIRED;
++b->expired_count;
continue;
}
/* if there are any outstanding pings - send another */
if (e->outstanding_pings > 0) {
ks_dhtrt_ping(internal, e);
++ping_count;
continue;
}
ks_time_t tdiff = t0 - e->tyme;
if (tdiff > KS_DHTRT_EXPIREDTIME) {
e->flags = DHTPEER_DUBIOUS; /* mark as dubious */
ks_dhtrt_ping(internal, e); /* final effort to activate */
continue;
}
if (tdiff > KS_DHTRT_INACTIVETIME) { /* inactive for suspicious length */
ks_dhtrt_ping(internal, e); /* kick */
++ping_count;
continue;
}
} /* end if not local */
} /* end if e->inuse */
} /* end for each bucket_entry */
#ifdef KS_DHT_DEBUGLOCKPRINTF_
char buf1[100];
ks_log(KS_LOG_DEBUG,"process_table: UNLOCKING bucket %s\n", ks_dhtrt_printableid(header->mask, buf1));
#endif
ks_rwl_write_unlock(b->lock);
} /* end of if trywrite_lock successful */
else {
#ifdef KS_DHT_DEBUGPRINTF_
char buf2[100];
ks_log(KS_LOG_DEBUG,"process_table: unble to LOCK bucket %s\n", ks_dhtrt_printableid(header->mask, buf2));
#endif
}
}
header = header->left;
if (header == 0 && stackix > 1) {
stackix -= 2;
header = stack[stackix];
header = header->right;
}
}
ks_rwl_read_unlock(internal->lock); /* release read lock */
ks_dhtrt_process_deleted(table);
if (ping_count == 0) {
internal->next_process_table_delta = KS_DHTRT_PROCESSTABLE_INTERVAL;
}
else {
internal->next_process_table_delta = KS_DHTRT_PROCESSTABLE_SHORTINTERVAL;
}
ks_log(KS_LOG_DEBUG,"process_table complete\n");
return;
}
void ks_dhtrt_process_deleted(ks_dhtrt_routetable_t *table)
{
ks_dhtrt_internal_t* internal = table->internal;
ks_mutex_lock(internal->deleted_node_lock);
ks_dhtrt_deletednode_t *deleted = internal->deleted_node;
ks_dhtrt_deletednode_t *prev = NULL, *temp=NULL;
#ifdef KS_DHT_DEBUGPRINTF_
ks_log(KS_LOG_DEBUG, "ALLOC process_deleted entry: internal->deleted_count %d\n", internal->deleted_count);
#endif
/* reclaim excess memory */
while(internal->deleted_count > KS_DHTRT_RECYCLE_NODE_THRESHOLD && deleted) {
ks_dht_node_t* node = deleted->node;
#ifdef KS_DHT_DEBUGPRINTFX__
ks_log(KS_LOG_DEBUG, "ALLOC process_deleted entry: try write lock\n");
#endif
if (ks_rwl_try_write_lock(node->reflock) == KS_STATUS_SUCCESS) {
ks_rwl_destroy(&(node->reflock));
ks_pool_free(table->pool, &node);
temp = deleted;
deleted = deleted->next;
ks_pool_free(table->pool, &temp);
--internal->deleted_count;
#ifdef KS_DHT_DEBUGPRINTFX_
ks_log(KS_LOG_DEBUG, "ALLOC process_deleted: internal->deleted_count %d\n", internal->deleted_count);
#endif
if (prev != NULL) {
prev->next = deleted;
}
else {
internal->deleted_node = deleted;
}
}
else {
#ifdef KS_DHT_DEBUGPRINTFX__
ks_log(KS_LOG_DEBUG, "ALLOC process_deleted entry: try write lock failed\n");
#endif
prev = deleted;
deleted = prev->next;
}
}
#ifdef KS_DHT_DEBUGPRINTF_
ks_log(KS_LOG_DEBUG, "ALLOC process_deleted exit: internal->deleted_count %d\n", internal->deleted_count);
#endif
ks_mutex_unlock(internal->deleted_node_lock);
}
KS_DECLARE(void) ks_dhtrt_dump(ks_dhtrt_routetable_t *table, int level) {
/* dump buffer headers */
char buffer[100];
memset(buffer, 0, 100);
ks_dhtrt_internal_t *internal = table->internal;
ks_dhtrt_bucket_header_t *header = internal->buckets;
ks_dhtrt_bucket_header_t *stack[KS_DHT_NODEID_SIZE * 8];
int stackix = 0;
ks_rwl_read_lock(internal->lock); /* grab read lock */
while (header) {
stack[stackix++] = header;
/* walk and report left handsize */
memset(buffer, 0, 100);
ks_log(KS_LOG_DEBUG, "bucket header: [%s]\n", ks_dhtrt_printableid(header->mask, buffer) );
if (header->bucket) {
ks_dhtrt_bucket_t *b = header->bucket;
ks_log(KS_LOG_DEBUG, " bucket holds %d entries\n", b->count);
if (b->count > 0 && level == 7) {
ks_log(KS_LOG_DEBUG, " --------------------------\n");
for (int ix=0; ix<KS_DHT_BUCKETSIZE; ++ix) {
memset(buffer, 0, 100);
if (b->entries[ix].inuse == 1) ks_dhtrt_printableid(b->entries[ix].id, buffer);
else strcpy(buffer, "<free>");
ks_log(KS_LOG_DEBUG, " slot %d: %d %d %s\n", ix,
b->entries[ix].flags,
b->entries[ix].outstanding_pings,
buffer);
}
ks_log(KS_LOG_DEBUG, " --------------------------\n\n");
}
}
header = header->left;
if (header == 0 && stackix > 1) {
stackix -= 2;
header = stack[stackix];
header = header->right;
}
}
ks_rwl_read_unlock(internal->lock); /* release read lock */
return;
}
/*
internal functions
*/
static
ks_dhtrt_bucket_header_t *ks_dhtrt_create_bucketheader(ks_pool_t *pool, ks_dhtrt_bucket_header_t *parent, uint8_t *mask)
{
ks_dhtrt_bucket_header_t *header = ks_pool_alloc(pool, sizeof(ks_dhtrt_bucket_header_t));
memcpy(header->mask, mask, sizeof(header->mask));
header->parent = parent;
#ifdef KS_DHT_DEBUGPRINTF_
char buffer[100];
ks_log(KS_LOG_DEBUG, "creating bucket header for mask: %s\n", ks_dhtrt_printableid(mask, buffer));
if (parent) ks_log(KS_LOG_DEBUG, " ... from parent mask: %s\n", ks_dhtrt_printableid(parent->mask, buffer));
#endif
return header;
}
static
ks_dhtrt_bucket_t *ks_dhtrt_create_bucket(ks_pool_t *pool)
{
ks_dhtrt_bucket_t *bucket = ks_pool_alloc(pool, sizeof(ks_dhtrt_bucket_t));
ks_rwl_create(&bucket->lock, pool);
return bucket;
}
static
ks_dhtrt_bucket_header_t *ks_dhtrt_find_bucketheader(ks_dhtrt_routetable_t *table, ks_dhtrt_nodeid_t id)
{
/* find the right bucket.
if a bucket header has a bucket, it does not children
so it must be the bucket to use
*/
ks_dhtrt_internal_t *internal = table->internal;
ks_dhtrt_bucket_header_t *header = internal->buckets;
while (header) {
if ( header->bucket ) {
return header;
}
/* left hand side is more restrictive (closer) so should be tried first */
if (header->left != 0 && (ks_dhtrt_ismasked(id, header->left->mask))) {
header = header->left;
} else {
header = header->right;
}
}
return NULL;
}
static
ks_dhtrt_bucket_header_t *ks_dhtrt_find_relatedbucketheader(ks_dhtrt_bucket_header_t *header, ks_dhtrt_nodeid_t id)
{
/*
using the passed bucket header as a starting point find the right bucket.
This is a shortcut used in query to shorten the search path for queries extending beyond a single bucket.
*/
while (header) {
if ( header->bucket ) {
return header;
}
/* left hand side is more restrictive (closer) so should be tried first */
if (header->left != 0 && (ks_dhtrt_ismasked(id, header->left->mask))) {
header = header->left;
} else {
header = header->right;
}
}
return NULL;
}
static
ks_dhtrt_bucket_entry_t *ks_dhtrt_find_bucketentry(ks_dhtrt_bucket_header_t *header, ks_dhtrt_nodeid_t nodeid)
{
ks_dhtrt_bucket_t *bucket = header->bucket;
if (bucket == 0) return NULL;
for (int ix=0; ix<KS_DHT_BUCKETSIZE; ++ix) {
if ( bucket->entries[ix].inuse == 1 &&
(!memcmp(nodeid, bucket->entries[ix].id, KS_DHT_NODEID_SIZE)) ) {
return &(bucket->entries[ix]);
}
}
return NULL;
}
static
void ks_dhtrt_split_bucket(ks_dhtrt_bucket_header_t *original,
ks_dhtrt_bucket_header_t *left,
ks_dhtrt_bucket_header_t *right)
{
/* so split the bucket in two based on the masks in the new header */
/* the existing bucket - with the remaining ids will be taken by the right hand side */
ks_dhtrt_bucket_t *source = original->bucket;
ks_dhtrt_bucket_t *dest = left->bucket;
int lix = 0;
int rix = 0;
for ( ; rix<KS_DHT_BUCKETSIZE; ++rix) {
if (ks_dhtrt_ismasked(source->entries[rix].id, left->mask)) {
/* move it to the left */
memcpy(dest->entries[lix].id, source->entries[rix].id, KS_DHT_NODEID_SIZE);
dest->entries[lix].gptr = source->entries[rix].gptr;
dest->entries[lix].family = source->entries[rix].family;
dest->entries[lix].type = source->entries[rix].type;
dest->entries[lix].inuse = 1;
++lix;
++dest->count;
/* now remove it from the original bucket */
source->entries[rix].inuse = 0;
--source->count;
}
}
/* give original bucket to the new left hand side header */
right->bucket = source;
original->bucket = 0;
original->left = left;
original->right = right;
#ifdef KS_DHT_DEBUGPRINTF_
char buffer[100];
ks_log(KS_LOG_DEBUG, "\nsplitting bucket orginal: %s\n", ks_dhtrt_printableid(original->mask, buffer));
ks_log(KS_LOG_DEBUG, " into (left) mask: %s size: %d\n", ks_dhtrt_printableid(left->mask, buffer), left->bucket->count);
ks_log(KS_LOG_DEBUG, " and (right) mask: %s size: %d\n", ks_dhtrt_printableid(right->mask, buffer), right->bucket->count);
#endif
return;
}
/*
* buckets are implemented as static array
* There does not seem to be any advantage in sorting/tree structures in terms of xor math
* so at least the static array does away with the need for locking.
*/
static
ks_status_t ks_dhtrt_insert_id(ks_dhtrt_bucket_t *bucket, ks_dht_node_t *node)
{
/* sanity checks */
if (!bucket || bucket->count > KS_DHT_BUCKETSIZE) {
assert(0);
}
uint8_t free = KS_DHT_BUCKETSIZE;
uint8_t expiredix = KS_DHT_BUCKETSIZE;
/* find free .. but also check that it is not already here! */
uint8_t ix = 0;
for (; ix<KS_DHT_BUCKETSIZE; ++ix) {
if (bucket->entries[ix].inuse == 0) {
if (free == KS_DHT_BUCKETSIZE) {
free = ix; /* use this one */
}
}
else if (free == KS_DHT_BUCKETSIZE && bucket->entries[ix].flags == DHTPEER_EXPIRED) {
expiredix = ix;
}
else if (!memcmp(bucket->entries[ix].id, node->nodeid.id, KS_DHT_NODEID_SIZE)) {
#ifdef KS_DHT_DEBUGPRINTF_
char buffer[100];
ks_log(KS_LOG_DEBUG, "duplicate peer %s found at %d\n", ks_dhtrt_printableid(node->nodeid.id, buffer), ix);
#endif
bucket->entries[ix].tyme = ks_time_now_sec();
return KS_STATUS_SUCCESS; /* already exists : leave flags unchanged */
}
}
if (free == KS_DHT_BUCKETSIZE && expiredix<KS_DHT_BUCKETSIZE ) {
/* bump this one - but only if we have no other option */
free = expiredix;
--bucket->expired_count;
}
if ( free<KS_DHT_BUCKETSIZE ) {
bucket->entries[free].inuse = 1;
bucket->entries[free].gptr = node;
bucket->entries[free].type = node->type;
bucket->entries[free].family = node->family;
bucket->entries[free].tyme = ks_time_now_sec();
bucket->entries[free].flags = DHTPEER_DUBIOUS;
if (free != expiredix) { /* are we are taking a free slot rather than replacing an expired node? */
++bucket->count; /* yes: increment total count */
}
memcpy(bucket->entries[free].id, node->nodeid.id, KS_DHT_NODEID_SIZE);
#ifdef KS_DHT_DEBUGPRINTF_
char buffer[100];
ks_log(KS_LOG_DEBUG, "Inserting node %s at %d\n", ks_dhtrt_printableid(node->nodeid.id, buffer), free);
#endif
return KS_STATUS_SUCCESS;
}
return KS_STATUS_FAIL;
}
static
ks_dht_node_t *ks_dhtrt_find_nodeid(ks_dhtrt_bucket_t *bucket, ks_dhtrt_nodeid_t id)
{
#ifdef KS_DHT_DEBUGPRINTF_
char buffer[100];
ks_log(KS_LOG_DEBUG, "Find nodeid for: %s\n", ks_dhtrt_printableid(id, buffer));
#endif
for (int ix=0; ix<KS_DHT_BUCKETSIZE; ++ix) {
#ifdef KS_DHT_DEBUGPRINTFX_
char bufferx[100];
if ( bucket->entries[ix].inuse == 1 && bucket->entries[ix].flags == DHTPEER_ACTIVE ) {
ks_log(KS_LOG_DEBUG, "bucket->entries[%d].id = %s inuse=%x\n", ix,
ks_dhtrt_printableid(bucket->entries[ix].id, bufferx),
bucket->entries[ix].inuse );
}
#endif
if ( bucket->entries[ix].inuse == 1 &&
(!memcmp(id, bucket->entries[ix].id, KS_DHT_NODEID_SIZE)) ) {
return bucket->entries[ix].gptr;
}
}
return NULL;
}
static
ks_status_t ks_dhtrt_delete_id(ks_dhtrt_bucket_t *bucket, ks_dhtrt_nodeid_t id)
{
#ifdef KS_DHT_DEBUGPRINTF_
char buffer[100];
ks_log(KS_LOG_DEBUG, "deleting node for: %s\n", ks_dhtrt_printableid(id, buffer));
#endif
for (int ix=0; ix<KS_DHT_BUCKETSIZE; ++ix) {
#ifdef KS_DHT_DEBUGPRINTFX_
char bufferx[100];
ks_log(KS_LOG_DEBUG, "bucket->entries[%d].id = %s inuse=%c\n", ix,
ks_dhtrt_printableid(bucket->entries[ix].id, bufferx),
bucket->entries[ix].inuse );
#endif
if ( bucket->entries[ix].inuse == 1 &&
(!memcmp(id, bucket->entries[ix].id, KS_DHT_NODEID_SIZE)) ) {
bucket->entries[ix].inuse = 0;
bucket->entries[ix].gptr = 0;
bucket->entries[ix].flags = 0;
--bucket->count;
return KS_STATUS_SUCCESS;
}
}
return KS_STATUS_FAIL;
}
static
uint8_t ks_dhtrt_findclosest_bucketnodes(ks_dhtrt_nodeid_t id,
enum ks_dht_nodetype_t type,
enum ks_afflags_t family,
ks_dhtrt_bucket_header_t *header,
ks_dhtrt_sortedxors_t *xors,
unsigned char *hixor, /*todo: remove */
unsigned int max) {
uint8_t count = 0; /* count of nodes added this time */
xors->startix = KS_DHT_BUCKETSIZE;
xors->count = 0;
xors->bheader = header;
unsigned char xorvalue[KS_DHT_NODEID_SIZE];
/* just ugh! - there must be a better way to do this */
/* walk the entire bucket calculating the xor value on the way */
/* add valid & relevant entries to the xor values */
ks_dhtrt_bucket_t *bucket = header->bucket;
if (bucket == 0) { /* sanity */
#ifdef KS_DHT_DEBUGPRINTF_
char buf[100];
ks_log(KS_LOG_DEBUG, "closestbucketnodes: intermediate tree node found %s\n",
ks_dhtrt_printableid(header->mask, buf));
#endif
}
ks_rwl_read_lock(bucket->lock); /* get a read lock : released in load_query when the results are copied */
#ifdef KS_DHT_DEBUGLOCKPRINTF_
char buf[100];
ks_log(KS_LOG_DEBUG, "closestbucketnodes: LOCKING bucket %s\n",
ks_dhtrt_printableid(header->mask, buf));
//fflush(stdout);
#endif
for (uint8_t ix=0; ix<KS_DHT_BUCKETSIZE; ++ix) {
if ( bucket->entries[ix].inuse == 1 && /* in use */
bucket->entries[ix].flags == DHTPEER_ACTIVE && /* not dubious or expired */
(family == ifboth || bucket->entries[ix].family == family) && /* match if family */
(bucket->entries[ix].type & type) && /* match type */
ks_dhtrt_isactive( &(bucket->entries[ix])) ) {
/* calculate xor value */
ks_dhtrt_xor(bucket->entries[ix].id, id, xorvalue );
/* do we need to hold this one */
if ( count < max || /* yes: we have not filled the quota yet */
(memcmp(xorvalue, hixor, KS_DHT_NODEID_SIZE) < 0)) { /* or is closer node than one already selected */
/* now sort the new xorvalue into the results structure */
/* this now becomes worst case O(n*2) logic - is there a better way */
/* in practice the bucket size is fixed so actual behavior is proably 0(logn) */
unsigned int xorix = xors->startix; /* start of ordered list */
unsigned int prev_xorix = KS_DHT_BUCKETSIZE;
for (int ix2=0; ix2<count; ++ix2) {
if (memcmp(xorvalue, xors->xort[xorix].xor, KS_DHT_NODEID_SIZE) > 0) {
break; /* insert before xorix, after prev_xoris */
}
prev_xorix = xorix;
xorix = xors->xort[xorix].nextix;
}
/* insert point found
count -> array slot to added newly identified node
insert_point -> the array slot before which we need to insert the newly identified node
*/
memcpy(xors->xort[count].xor, xorvalue, KS_DHT_NODEID_SIZE);
xors->xort[count].ix = ix;
xors->xort[count].nextix = xorix; /* correct forward chain */
if (prev_xorix < KS_DHT_BUCKETSIZE) { /* correct backward chain */
xors->xort[prev_xorix].nextix = count;
} else {
xors->startix = count;
}
++count;
}
}
}
xors->count = count;
return count; /* return count of added nodes */
}
static
uint8_t ks_dhtrt_load_query(ks_dhtrt_querynodes_t *query, ks_dhtrt_sortedxors_t *xort)
{
ks_dhtrt_sortedxors_t *current = xort;
uint8_t loaded = 0;
while (current) {
#ifdef KS_DHT_DEBUGPRINTF_
char buf[100];
ks_log(KS_LOG_DEBUG, " loadquery from bucket %s count %d\n",
ks_dhtrt_printableid(current->bheader->mask,buf), current->count);
#endif
int xorix = current->startix;
for (uint8_t ix = 0;
ix< current->count && loaded < query->max && xorix != KS_DHT_BUCKETSIZE;
++ix ) {
unsigned int z = current->xort[xorix].ix;
query->nodes[ix] = current->bheader->bucket->entries[z].gptr;
xorix = current->xort[xorix].nextix;
++loaded;
}
#ifdef KS_DHT_DEBUGLOCKPRINTF_
char buf1[100];
ks_log(KS_LOG_DEBUG, "load_query: UNLOCKING bucket %s\n",
ks_dhtrt_printableid(current->bheader->mask, buf1));
fflush(stdout);
#endif
ks_rwl_read_unlock(current->bheader->bucket->lock); /* release the read lock from findclosest_bucketnodes */
if (loaded >= query->max) break;
current = current->next;
}
query->count = loaded;
return loaded;
}
void ks_dhtrt_queue_node_fordelete(ks_dhtrt_routetable_t* table, ks_dht_node_t* node)
{
ks_dhtrt_internal_t* internal = table->internal;
ks_mutex_lock(internal->deleted_node_lock);
ks_dhtrt_deletednode_t* deleted = internal->free_node_ex; /* grab a free stub */
if (deleted) {
internal->free_node_ex = deleted->next;
}
else {
deleted = ks_pool_alloc(table->pool, sizeof(ks_dhtrt_deletednode_t));
}
deleted->node = node;
deleted->next = internal->deleted_node;
internal->deleted_node = deleted; /* add to deleted queue */
++internal->deleted_count;
#ifdef KS_DHT_DEBUGPRINTFX_
ks_log(KS_LOG_DEBUG, "ALLOC: Queue for delete %d\n", internal->deleted_count);
#endif
ks_mutex_unlock(internal->deleted_node_lock);
}
ks_dht_node_t* ks_dhtrt_make_node(ks_dhtrt_routetable_t* table)
{
ks_dht_node_t *node = NULL;
ks_dhtrt_internal_t *internal = table->internal;
ks_mutex_lock(internal->deleted_node_lock);
/* to to reuse a deleted node */
if (internal->deleted_count) {
ks_dhtrt_deletednode_t *deleted = internal->deleted_node;
node = deleted->node; /* take the node */
memset(node, 0, sizeof(ks_dht_node_t));
deleted->node = 0; /* avoid accidents */
internal->deleted_node = deleted->next;
deleted->next = internal->free_node_ex; /* save the stub for reuse */
--internal->deleted_count;
#ifdef KS_DHT_DEBUGPRINTFX_
ks_log(KS_LOG_DEBUG, "ALLOC: Reusing a node struct %d\n", internal->deleted_count);
#endif
}
ks_mutex_unlock(internal->deleted_node_lock);
if (!node) {
node = ks_pool_alloc(table->pool, sizeof(ks_dht_node_t));
}
return node;
}
void ks_dhtrt_ping(ks_dhtrt_internal_t *internal, ks_dhtrt_bucket_entry_t *entry) {
++entry->outstanding_pings;
#ifdef KS_DHT_DEBUGPRINTF_
char buf[100];
ks_log(KS_LOG_DEBUG, "Ping queued for nodeid %s count %d\n",
ks_dhtrt_printableid(entry->id,buf), entry->outstanding_pings);
#endif
ks_dht_node_t* node = entry->gptr;
ks_dht_ping(internal->dht, &node->addr, NULL);
return;
}
/*
strictly for shifting the bucketheader mask
so format must be a right filled mask (hex: ..ffffffff)
*/
static
void ks_dhtrt_shiftright(uint8_t *id)
{
unsigned char b0 = 0;
unsigned char b1 = 0;
for (int i = KS_DHT_NODEID_SIZE-1; i >= 0; --i) {
if (id[i] == 0) break; /* beyond mask- we are done */
b1 = id[i] & 0x01;
id[i] >>= 1;
if (i != (KS_DHT_NODEID_SIZE-1)) {
id[i+1] |= (b0 << 7);
}
b0 = b1;
}
return;
}
static
void ks_dhtrt_shiftleft(uint8_t *id) {
for (int i = KS_DHT_NODEID_SIZE-1; i >= 0; --i) {
if (id[i] == 0xff) continue;
id[i] <<= 1;
id[i] |= 0x01;
break;
}
return;
}
/* create an xor value from two ids */
static void ks_dhtrt_xor(const uint8_t *id1, const uint8_t *id2, uint8_t *xor)
{
for (int i = 0; i < KS_DHT_NODEID_SIZE; ++i) {
if (id1[i] == id2[i]) {
xor[i] = 0;
}
xor[i] = id1[i] ^ id2[i];
}
return;
}
/* is id masked by mask 1 => yes, 0=> no */
static int ks_dhtrt_ismasked(const uint8_t *id, const unsigned char *mask)
{
for (int i = 0; i < KS_DHT_NODEID_SIZE; ++i) {
if (mask[i] == 0 && id[i] != 0) return 0;
else if (mask[i] == 0xff) return 1;
else if (id[i] > mask[i]) return 0;
}
return 1;
}
static char *ks_dhtrt_printableid(uint8_t *id, char *buffer)
{
char *t = buffer;
memset(buffer, 0, KS_DHT_NODEID_SIZE*2);
for (int i = 0; i < KS_DHT_NODEID_SIZE; ++i, buffer+=2) {
sprintf(buffer, "%02x", id[i]);
}
return t;
}
unsigned char ks_dhtrt_isactive(ks_dhtrt_bucket_entry_t *entry)
{
/* todo */
return 1;
}
/* For Emacs:
* Local Variables:
* mode:c
* indent-tabs-mode:t
* tab-width:4
* c-basic-offset:4
* End:
* For VIM:
* vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet:
*/
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