static void
phaseOne( tr_ptrArray * peerArray, tr_direction dir )
{
int i, n;
int peerCount = tr_ptrArraySize( peerArray );
struct tr_peerIo ** peers = (struct tr_peerIo**) tr_ptrArrayBase( peerArray );
/* First phase of IO. Tries to distribute bandwidth fairly to keep faster
* peers from starving the others. Loop through the peers, giving each a
* small chunk of bandwidth. Keep looping until we run out of bandwidth
* and/or peers that can use it */
n = peerCount;
dbgmsg( "%d peers to go round-robin for %s", n, (dir==TR_UP?"upload":"download") );
i = n ? tr_cryptoWeakRandInt( n ) : 0; /* pick a random starting point */
while( n > 1 )
{
const size_t increment = 1024;
const int bytesUsed = tr_peerIoFlush( peers[i], dir, increment );
dbgmsg( "peer #%d of %d used %d bytes in this pass", i, n, bytesUsed );
if( bytesUsed == (int)increment )
++i;
else {
/* peer is done writing for now; move it to the end of the list */
tr_peerIo * pio = peers[i];
peers[i] = peers[n-1];
peers[n-1] = pio;
--n;
}
if( i == n )
i = 0;
}
}
static int
test_quickFindFirst_Iteration (const size_t k, const size_t n, int * buf, int range)
{
size_t i;
int highest_low;
int lowest_high;
/* populate buf with random ints */
for (i=0; i<n; ++i)
buf[i] = tr_cryptoWeakRandInt (range);
/* find the best k */
tr_quickfindFirstK (buf, n, sizeof(int), compareInts, k);
/* confirm that the smallest K ints are in the first slots K slots in buf */
highest_low = INT_MIN;
for (i=0; i<k; ++i)
if (highest_low < buf[i])
highest_low = buf[i];
lowest_high = INT_MAX;
for (i=k; i<n; ++i)
if (lowest_high > buf[i])
lowest_high = buf[i];
check (highest_low <= lowest_high);
return 0;
}
static void
nap( int roughly_sec )
{
const int roughly_msec = roughly_sec * 1000;
const int msec = roughly_msec/2 + tr_cryptoWeakRandInt(roughly_msec);
tr_wait_msec( msec );
}
static void
phaseOne (tr_ptrArray * peerArray, tr_direction dir)
{
int n;
int peerCount = tr_ptrArraySize (peerArray);
struct tr_peerIo ** peers = (struct tr_peerIo**) tr_ptrArrayBase (peerArray);
/* First phase of IO. Tries to distribute bandwidth fairly to keep faster
* peers from starving the others. Loop through the peers, giving each a
* small chunk of bandwidth. Keep looping until we run out of bandwidth
* and/or peers that can use it */
n = peerCount;
dbgmsg ("%d peers to go round-robin for %s", n, (dir==TR_UP?"upload":"download"));
while (n > 0)
{
const int i = tr_cryptoWeakRandInt (n); /* pick a peer at random */
/* value of 3000 bytes chosen so that when using uTP we'll send a full-size
* frame right away and leave enough buffered data for the next frame to go
* out in a timely manner. */
const size_t increment = 3000;
const int bytesUsed = tr_peerIoFlush (peers[i], dir, increment);
dbgmsg ("peer #%d of %d used %d bytes in this pass", i, n, bytesUsed);
if (bytesUsed != (int)increment) {
/* peer is done writing for now; move it to the end of the list */
tr_peerIo * pio = peers[i];
peers[i] = peers[n-1];
peers[n-1] = pio;
--n;
}
}
}
static int
test_bitfield_count_range (void)
{
int i;
int n;
int begin;
int end;
int count1;
int count2;
const int bitCount = 100 + tr_cryptoWeakRandInt (1000);
tr_bitfield bf;
/* generate a random bitfield */
tr_bitfieldConstruct (&bf, bitCount);
for (i=0, n=tr_cryptoWeakRandInt (bitCount); i<n; ++i)
tr_bitfieldAdd (&bf, tr_cryptoWeakRandInt (bitCount));
begin = tr_cryptoWeakRandInt (bitCount);
do
end = tr_cryptoWeakRandInt (bitCount);
while (end == begin);
/* ensure end <= begin */
if (end < begin)
{
const int tmp = begin;
begin = end;
end = tmp;
}
/* test the bitfield */
count1 = 0;
for (i=begin; i<end; ++i)
if (tr_bitfieldHas (&bf, i))
++count1;
count2 = tr_bitfieldCountRange (&bf, begin, end);
check (count1 == count2);
/* cleanup */
tr_bitfieldDestruct (&bf);
return 0;
}
int
tr_cryptoRandInt( int upperBound )
{
int noise;
int val;
assert( upperBound > 0 );
if( RAND_pseudo_bytes ( (unsigned char *) &noise, sizeof noise ) >= 0 )
{
val = abs( noise ) % upperBound;
}
else /* fall back to a weaker implementation... */
{
val = tr_cryptoWeakRandInt( upperBound );
}
return val;
}
int
tr_dhtInit(tr_session *ss, const tr_address * tr_addr)
{
struct sockaddr_in sin;
tr_benc benc;
int rc;
tr_bool have_id = FALSE;
char * dat_file;
uint8_t * nodes = NULL, * nodes6 = NULL;
const uint8_t * raw;
size_t len, len6;
struct bootstrap_closure * cl;
if( session ) /* already initialized */
return -1;
dht_port = tr_sessionGetPeerPort(ss);
if(dht_port <= 0)
return -1;
tr_ndbg( "DHT", "Initializing DHT" );
dht_socket = socket(PF_INET, SOCK_DGRAM, 0);
if(dht_socket < 0)
goto fail;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
memcpy(&sin.sin_addr, &tr_addr->addr.addr4, sizeof (struct in_addr));
sin.sin_port = htons(dht_port);
rc = bind(dht_socket, (struct sockaddr*)&sin, sizeof(sin));
if(rc < 0)
goto fail;
if(tr_globalIPv6())
rebind_ipv6(TRUE);
if( getenv( "TR_DHT_VERBOSE" ) != NULL )
dht_debug = stderr;
dat_file = tr_buildPath( ss->configDir, "dht.dat", NULL );
rc = tr_bencLoadFile( &benc, TR_FMT_BENC, dat_file );
tr_free( dat_file );
if(rc == 0) {
have_id = tr_bencDictFindRaw(&benc, "id", &raw, &len);
if( have_id && len==20 )
memcpy( myid, raw, len );
if( dht_socket >= 0 &&
tr_bencDictFindRaw( &benc, "nodes", &raw, &len ) && !(len%6) ) {
nodes = tr_memdup( raw, len );
}
if( dht6_socket > 0 &&
tr_bencDictFindRaw( &benc, "nodes6", &raw, &len6 ) && !(len6%18) ) {
nodes6 = tr_memdup( raw, len6 );
}
tr_bencFree( &benc );
}
if(nodes == NULL)
len = 0;
if(nodes6 == NULL)
len6 = 0;
if( have_id )
tr_ninf( "DHT", "Reusing old id" );
else {
/* Note that DHT ids need to be distributed uniformly,
* so it should be something truly random. */
tr_ninf( "DHT", "Generating new id" );
tr_cryptoRandBuf( myid, 20 );
}
rc = dht_init( dht_socket, dht6_socket, myid, NULL );
if( rc < 0 )
goto fail;
session = ss;
cl = tr_new( struct bootstrap_closure, 1 );
cl->session = session;
cl->nodes = nodes;
cl->nodes6 = nodes6;
cl->len = len;
cl->len6 = len6;
tr_threadNew( dht_bootstrap, cl );
dht_event = event_new( session->event_base, dht_socket, EV_READ, event_callback, NULL );
tr_timerAdd( dht_event, 0, tr_cryptoWeakRandInt( 1000000 ) );
if( dht6_socket >= 0 )
{
dht6_event = event_new( session->event_base, dht6_socket, EV_READ, event_callback, NULL );
tr_timerAdd( dht6_event, 0, tr_cryptoWeakRandInt( 1000000 ) );
}
tr_ndbg( "DHT", "DHT initialized" );
return 1;
fail:
{
const int save = errno;
close(dht_socket);
if( dht6_socket >= 0 )
close(dht6_socket);
dht_socket = dht6_socket = -1;
session = NULL;
tr_ndbg( "DHT", "DHT initialization failed (errno = %d)", save );
errno = save;
}
return -1;
}
static tr_port
getRandomPort( tr_session * s )
{
return tr_cryptoWeakRandInt( s->randomPortHigh - s->randomPortLow + 1) + s->randomPortLow;
}
int
tr_dhtInit(tr_session *ss)
{
tr_benc benc;
int rc;
bool have_id = false;
char * dat_file;
uint8_t * nodes = NULL, * nodes6 = NULL;
const uint8_t * raw;
size_t len, len6;
struct bootstrap_closure * cl;
if( session ) /* already initialized */
return -1;
tr_ndbg( "DHT", "Initializing DHT" );
if( getenv( "TR_DHT_VERBOSE" ) != NULL )
dht_debug = stderr;
dat_file = tr_buildPath( ss->configDir, "dht.dat", NULL );
rc = tr_bencLoadFile( &benc, TR_FMT_BENC, dat_file );
tr_free( dat_file );
if(rc == 0) {
have_id = tr_bencDictFindRaw(&benc, "id", &raw, &len);
if( have_id && len==20 )
memcpy( myid, raw, len );
if( ss->udp_socket >= 0 &&
tr_bencDictFindRaw( &benc, "nodes", &raw, &len ) && !(len%6) ) {
nodes = tr_memdup( raw, len );
}
if( ss->udp6_socket > 0 &&
tr_bencDictFindRaw( &benc, "nodes6", &raw, &len6 ) && !(len6%18) ) {
nodes6 = tr_memdup( raw, len6 );
}
tr_bencFree( &benc );
}
if(nodes == NULL)
len = 0;
if(nodes6 == NULL)
len6 = 0;
if( have_id )
tr_ninf( "DHT", "Reusing old id" );
else {
/* Note that DHT ids need to be distributed uniformly,
* so it should be something truly random. */
tr_ninf( "DHT", "Generating new id" );
tr_cryptoRandBuf( myid, 20 );
}
rc = dht_init( ss->udp_socket, ss->udp6_socket, myid, NULL );
if( rc < 0 )
goto fail;
session = ss;
cl = tr_new( struct bootstrap_closure, 1 );
cl->session = session;
cl->nodes = nodes;
cl->nodes6 = nodes6;
cl->len = len;
cl->len6 = len6;
tr_threadNew( dht_bootstrap, cl );
dht_timer = evtimer_new( session->event_base, timer_callback, session );
tr_timerAdd( dht_timer, 0, tr_cryptoWeakRandInt( 1000000 ) );
tr_ndbg( "DHT", "DHT initialized" );
return 1;
fail:
tr_ndbg( "DHT", "DHT initialization failed (errno = %d)", errno );
session = NULL;
return -1;
}
void
tr_bandwidthAllocate( tr_bandwidth * b,
tr_direction dir,
int period_msec )
{
int i, n, peerCount;
tr_ptrArray * tmp;
struct tr_peerIo ** peers;
const uint64_t now = tr_date( );
const uint64_t cutoff = now + 100; /* 1/10th of a second */
/* allocateBandwidth() is a helper function with two purposes:
* 1. allocate bandwidth to b and its subtree
* 2. accumulate an array of all the peerIos from b and its subtree. */
tmp = tr_ptrArrayNew( );
allocateBandwidth( b, dir, period_msec, tmp );
peers = (struct tr_peerIo**) tr_ptrArrayPeek( tmp, &peerCount );
/* Stop all peers from listening for the socket to be ready for IO.
* See "Second phase of IO" lower in this function for more info. */
for( i=0; i<peerCount; ++i )
tr_peerIoSetEnabled( peers[i], dir, FALSE );
/* First phase of IO. Tries to distribute bandwidth fairly to keep faster
* peers from starving the others. Loop through the peers, giving each a
* small chunk of bandwidth. Keep looping until we run out of bandwidth
* or peers that can use it */
n = peerCount;
i = n ? tr_cryptoWeakRandInt( n ) : 0; /* pick a random starting point */
for( ; n>0 && tr_date()<=cutoff; )
{
const int increment = n==1 ? 4096 : 1024;
const int byteCount = tr_peerIoFlush( peers[i], dir, increment);
if( byteCount == increment )
++i;
else {
/* peer is done writing for now; move it to the end of the list */
tr_peerIo * tmp = peers[i];
peers[i] = peers[n-1];
peers[n-1] = tmp;
--n;
}
assert( i <= n );
if( i == n )
i = 0;
}
/* Second phase of IO. To help us scale in high bandwidth situations,
* enable on-demand IO for peers with bandwidth left to burn.
* This on-demand IO is enabled until (1) the peer runs out of bandwidth,
* or (2) the next tr_bandwidthAllocate() call, when we start over again. */
for( i=0; i<peerCount; ++i )
if( tr_peerIoHasBandwidthLeft( peers[i], dir ) )
tr_peerIoSetEnabled( peers[i], dir, TRUE );
/* cleanup */
tr_ptrArrayFree( tmp, NULL );
}
