d4708/opentracker
1
0
Fork 0
mirror of git://erdgeist.org/opentracker synced 2025-02-04 19:16:23 +00:00
Code Issues Projects Releases Wiki Activity

Turn random() to nrand48 in inner loop where it is not cryptographically relevant to avoid futex storm. Thanks and credits to Bart Smienk

Browse Source
This commit is contained in:
Dirk Engling 2021-04-20 03:48:50 +02:00
parent 0695b48870
commit 616119ee22
3 changed files with 16 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
opentracker.c
View File

@ -258,6 +258,9 @@ static void * server_mainloop( void * args ) {
#endif
if( !ws.inbuf || !ws.outbuf )
panic( "Initializing worker failed" );
ws.rand48_state[0] = (uint16_t)random();
ws.rand48_state[1] = (uint16_t)random();
ws.rand48_state[2] = (uint16_t)random();
for( ; ; ) {
int64 sock;

14
trackerlogic.c
View File

@ -29,7 +29,7 @@
#include "ot_livesync.h"
/* Forward declaration */
size_t return_peers_for_torrent( ot_torrent *torrent, size_t amount, char *reply, PROTO_FLAG proto );
size_t return_peers_for_torrent( struct ot_workstruct * ws, ot_torrent *torrent, size_t amount, char *reply, PROTO_FLAG proto );
void free_peerlist( ot_peerlist *peer_list ) {
if( peer_list->peers.data ) {
@ -178,7 +178,7 @@ size_t add_peer_to_torrent_and_return_peers( PROTO_FLAG proto, struct ot_workstr
}
#endif
ws->reply_size = return_peers_for_torrent( torrent, amount, ws->reply, proto );
ws->reply_size = return_peers_for_torrent( ws, torrent, amount, ws->reply, proto );
mutex_bucket_unlock_by_hash( *ws->hash, delta_torrentcount );
return ws->reply_size;
}
@ -210,7 +210,7 @@ static size_t return_peers_all( ot_peerlist *peer_list, char *reply ) {
return result;
}
static size_t return_peers_selection( ot_peerlist *peer_list, size_t amount, char *reply ) {
static size_t return_peers_selection( struct ot_workstruct *ws, ot_peerlist *peer_list, size_t amount, char *reply ) {
unsigned int bucket_offset, bucket_index = 0, num_buckets = 1;
ot_vector * bucket_list = &peer_list->peers;
unsigned int shifted_pc = peer_list->peer_count;
@ -232,7 +232,7 @@ static size_t return_peers_selection( ot_peerlist *peer_list, size_t amount, cha
/* Initialize somewhere in the middle of peers so that
fixpoint's aliasing doesn't alway miss the same peers */
bucket_offset = random() % peer_list->peer_count;
bucket_offset = nrand48(ws->rand48_state) % peer_list->peer_count;
while( amount-- ) {
ot_peer * peer;
@ -240,7 +240,7 @@ static size_t return_peers_selection( ot_peerlist *peer_list, size_t amount, cha
/* This is the aliased, non shifted range, next value may fall into */
unsigned int diff = ( ( ( amount + 1 ) * shifted_step ) >> shift ) -
( ( amount * shifted_step ) >> shift );
bucket_offset += 1 + random() % diff;
bucket_offset += 1 + nrand48(ws->rand48_state) % diff;
while( bucket_offset >= bucket_list[bucket_index].size ) {
bucket_offset -= bucket_list[bucket_index].size;
@ -262,7 +262,7 @@ static size_t return_peers_selection( ot_peerlist *peer_list, size_t amount, cha
* reply must have enough space to hold 92+6*amount bytes
* does not yet check not to return self
*/
size_t return_peers_for_torrent( ot_torrent *torrent, size_t amount, char *reply, PROTO_FLAG proto ) {
size_t return_peers_for_torrent( struct ot_workstruct * ws, ot_torrent *torrent, size_t amount, char *reply, PROTO_FLAG proto ) {
ot_peerlist *peer_list = torrent->peer_list;
char *r = reply;
@ -283,7 +283,7 @@ size_t return_peers_for_torrent( ot_torrent *torrent, size_t amount, char *reply
if( amount == peer_list->peer_count )
r += return_peers_all( peer_list, r );
else
r += return_peers_selection( peer_list, amount, r );
r += return_peers_selection( ws, peer_list, amount, r );
}
if( proto == FLAG_TCP )

7
trackerlogic.h
View File

@ -10,6 +10,7 @@
#include <sys/time.h>
#include <time.h>
#include <stdint.h>
#include <stdlib.h>
typedef uint8_t ot_hash[20];
typedef time_t ot_time;
@ -34,7 +35,7 @@ typedef struct { ot_ip6 address; int bits; }
#define OT_TORRENT_TIMEOUT_HOURS 24
#define OT_TORRENT_TIMEOUT (60*OT_TORRENT_TIMEOUT_HOURS)
#define OT_CLIENT_REQUEST_INTERVAL_RANDOM ( OT_CLIENT_REQUEST_INTERVAL - OT_CLIENT_REQUEST_VARIATION/2 + (int)( random( ) % OT_CLIENT_REQUEST_VARIATION ) )
#define OT_CLIENT_REQUEST_INTERVAL_RANDOM ( OT_CLIENT_REQUEST_INTERVAL - OT_CLIENT_REQUEST_VARIATION/2 + (int)( nrand48(ws->rand48_state) % OT_CLIENT_REQUEST_VARIATION ) )
/* If WANT_MODEST_FULLSCRAPES is on, ip addresses may not
fullscrape more frequently than this amount in seconds */
@ -131,6 +132,10 @@ struct ot_workstruct {
ssize_t header_size;
char *reply;
ssize_t reply_size;
/* Entropy state for rand48 function so that threads don't need to acquire mutexes for
global random() or arc4random() state, which causes heavy load on linuxes */
uint16_t rand48_state[3];
};
/*