An open and free bittorrent tracker https://erdgeist.org/gitweb/opentracker
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/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
It is considered beerware. Prost. Skol. Cheers or whatever.
Some of the stuff below is stolen from Fefes example libowfat httpd.
$Id: opentracker.c,v 1.239 2014/10/06 22:32:28 git Exp $ */
/* System */
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <pwd.h>
#include <ctype.h>
#include <pthread.h>
#ifdef WANT_SYSLOGS
#include <syslog.h>
#endif
/* Libowfat */
#include "socket.h"
#include "io.h"
#include "iob.h"
#include "byte.h"
#include "scan.h"
#include "ip6.h"
/* Opentracker */
#include "trackerlogic.h"
#include "ot_mutex.h"
#include "ot_http.h"
#include "ot_udp.h"
#include "ot_accesslist.h"
#include "ot_stats.h"
#include "ot_livesync.h"
/* Globals */
time_t g_now_seconds;
char * g_redirecturl;
uint32_t g_tracker_id;
volatile int g_opentracker_running = 1;
int g_self_pipe[2];
static char * g_serverdir;
static char * g_serveruser;
static unsigned int g_udp_workers;
static void panic( const char *routine ) {
fprintf( stderr, "%s: %s\n", routine, strerror(errno) );
exit( 111 );
}
static void signal_handler( int s ) {
if( s == SIGINT ) {
/* Any new interrupt signal quits the application */
signal( SIGINT, SIG_DFL);
/* Tell all other threads to not acquire any new lock on a bucket
but cancel their operations and return */
g_opentracker_running = 0;
trackerlogic_deinit();
#ifdef WANT_SYSLOGS
closelog();
#endif
exit( 0 );
} else if( s == SIGALRM ) {
/* Maintain our copy of the clock. time() on BSDs is very expensive. */
g_now_seconds = time(NULL);
alarm(5);
}
}
static void defaul_signal_handlers( void ) {
sigset_t signal_mask;
sigemptyset(&signal_mask);
sigaddset (&signal_mask, SIGPIPE);
sigaddset (&signal_mask, SIGHUP);
sigaddset (&signal_mask, SIGINT);
sigaddset (&signal_mask, SIGALRM);
pthread_sigmask (SIG_BLOCK, &signal_mask, NULL);
}
static void install_signal_handlers( void ) {
struct sigaction sa;
sigset_t signal_mask;
sigemptyset(&signal_mask);
sa.sa_handler = signal_handler;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
if ((sigaction(SIGINT, &sa, NULL) == -1) || (sigaction(SIGALRM, &sa, NULL) == -1) )
panic( "install_signal_handlers" );
sigaddset (&signal_mask, SIGINT);
sigaddset (&signal_mask, SIGALRM);
pthread_sigmask (SIG_UNBLOCK, &signal_mask, NULL);
}
static void usage( char *name ) {
fprintf( stderr, "Usage: %s [-i ip] [-p port] [-P port] [-r redirect] [-d dir] [-u user] [-A ip] [-f config] [-s livesyncport]"
#ifdef WANT_ACCESSLIST_BLACK
" [-b blacklistfile]"
#elif defined ( WANT_ACCESSLIST_WHITE )
" [-w whitelistfile]"
#endif
"\n", name );
}
#define HELPLINE(opt,desc) fprintf(stderr, "\t%-10s%s\n",opt,desc)
static void help( char *name ) {
usage( name );
HELPLINE("-f config","include and execute the config file");
HELPLINE("-i ip","specify ip to bind to (default: *, you may specify more than one)");
HELPLINE("-p port","specify tcp port to bind to (default: 6969, you may specify more than one)");
HELPLINE("-P port","specify udp port to bind to (default: 6969, you may specify more than one)");
HELPLINE("-r redirecturl","specify url where / should be redirected to (default none)");
HELPLINE("-d dir","specify directory to try to chroot to (default: \".\")");
HELPLINE("-u user","specify user under whose priviliges opentracker should run (default: \"nobody\")");
HELPLINE("-A ip","bless an ip address as admin address (e.g. to allow syncs from this address)");
#ifdef WANT_ACCESSLIST_BLACK
HELPLINE("-b file","specify blacklist file.");
#elif defined( WANT_ACCESSLIST_WHITE )
HELPLINE("-w file","specify whitelist file.");
#endif
fprintf( stderr, "\nExample: ./opentracker -i 127.0.0.1 -p 6969 -P 6969 -f ./opentracker.conf -i 10.1.1.23 -p 2710 -p 80\n" );
}
#undef HELPLINE
static size_t header_complete( char * request, ssize_t byte_count ) {
int i = 0, state = 0;
for( i=1; i < byte_count; i+=2 )
if( request[i] <= 13 ) {
i--;
for( state = 0 ; i < byte_count; ++i ) {
char c = request[i];
if( c == '\r' || c == '\n' )
state = ( state >> 2 ) | ( ( c << 6 ) & 0xc0 );
else
break;
if( state >= 0xa0 || state == 0x99 ) return i + 1;
}
}
return 0;
}
static void handle_dead( const int64 sock ) {
struct http_data* cookie=io_getcookie( sock );
if( cookie ) {
iob_reset( &cookie->batch );
array_reset( &cookie->request );
if( cookie->flag & STRUCT_HTTP_FLAG_WAITINGFORTASK )
mutex_workqueue_canceltask( sock );
free( cookie );
}
io_close( sock );
}
static void handle_read( const int64 sock, struct ot_workstruct *ws ) {
struct http_data* cookie = io_getcookie( sock );
ssize_t byte_count;
if( ( byte_count = io_tryread( sock, ws->inbuf, G_INBUF_SIZE ) ) <= 0 ) {
handle_dead( sock );
return;
}
/* If we get the whole request in one packet, handle it without copying */
if( !array_start( &cookie->request ) ) {
if( ( ws->header_size = header_complete( ws->inbuf, byte_count ) ) ) {
ws->request = ws->inbuf;
ws->request_size = byte_count;
http_handle_request( sock, ws );
} else
array_catb( &cookie->request, ws->inbuf, byte_count );
return;
}
array_catb( &cookie->request, ws->inbuf, byte_count );
if( array_failed( &cookie->request ) || array_bytes( &cookie->request ) > 8192 ) {
http_issue_error( sock, ws, CODE_HTTPERROR_500 );
return;
}
while( ( ws->header_size = header_complete( array_start( &cookie->request ), array_bytes( &cookie->request ) ) ) ) {
ws->request = array_start( &cookie->request );
ws->request_size = array_bytes( &cookie->request );
http_handle_request( sock, ws );
#ifdef WANT_KEEPALIVE
if( !ws->keep_alive )
#endif
return;
}
}
static void handle_write( const int64 sock ) {
struct http_data* cookie=io_getcookie( sock );
if( !cookie || ( iob_send( sock, &cookie->batch ) <= 0 ) )
handle_dead( sock );
}
static void handle_accept( const int64 serversocket ) {
struct http_data *cookie;
int64 sock;
ot_ip6 ip;
uint16 port;
tai6464 t;
while( ( sock = socket_accept6( serversocket, ip, &port, NULL ) ) != -1 ) {
/* Put fd into a non-blocking mode */
io_nonblock( sock );
if( !io_fd( sock ) ||
!( cookie = (struct http_data*)malloc( sizeof(struct http_data) ) ) ) {
io_close( sock );
continue;
}
memset(cookie, 0, sizeof( struct http_data ) );
memcpy(cookie->ip,ip,sizeof(ot_ip6));
io_setcookie( sock, cookie );
io_wantread( sock );
stats_issue_event( EVENT_ACCEPT, FLAG_TCP, (uintptr_t)ip);
/* That breaks taia encapsulation. But there is no way to take system
time this often in FreeBSD and libowfat does not allow to set unix time */
taia_uint( &t, 0 ); /* Clear t */
tai_unix( &(t.sec), (g_now_seconds + OT_CLIENT_TIMEOUT) );
io_timeout( sock, t );
}
}
static void * server_mainloop( void * args ) {
struct ot_workstruct ws;
time_t next_timeout_check = g_now_seconds + OT_CLIENT_TIMEOUT_CHECKINTERVAL;
struct iovec *iovector;
int iovec_entries;
(void)args;
/* Initialize our "thread local storage" */
ws.inbuf = malloc( G_INBUF_SIZE );
ws.outbuf = malloc( G_OUTBUF_SIZE );
#ifdef _DEBUG_HTTPERROR
ws.debugbuf= malloc( G_DEBUGBUF_SIZE );
#endif
if( !ws.inbuf || !ws.outbuf )
panic( "Initializing worker failed" );
for( ; ; ) {
int64 sock;
io_wait();
while( ( sock = io_canread( ) ) != -1 ) {
const void *cookie = io_getcookie( sock );
if( (intptr_t)cookie == FLAG_TCP )
handle_accept( sock );
else if( (intptr_t)cookie == FLAG_UDP )
handle_udp6( sock, &ws );
else if( (intptr_t)cookie == FLAG_SELFPIPE )
io_tryread( sock, ws.inbuf, G_INBUF_SIZE );
else
handle_read( sock, &ws );
}
while( ( sock = mutex_workqueue_popresult( &iovec_entries, &iovector ) ) != -1 )
http_sendiovecdata( sock, &ws, iovec_entries, iovector );
while( ( sock = io_canwrite( ) ) != -1 )
handle_write( sock );
if( g_now_seconds > next_timeout_check ) {
while( ( sock = io_timeouted() ) != -1 )
handle_dead( sock );
next_timeout_check = g_now_seconds + OT_CLIENT_TIMEOUT_CHECKINTERVAL;
}
livesync_ticker();
/* Enforce setting the clock */
signal_handler( SIGALRM );
}
return 0;
}
static int64_t ot_try_bind( ot_ip6 ip, uint16_t port, PROTO_FLAG proto ) {
int64 sock = proto == FLAG_TCP ? socket_tcp6( ) : socket_udp6( );
#ifndef WANT_V6
if( !ip6_isv4mapped(ip) ) {
exerr( "V4 Tracker is V4 only!" );
}
#else
if( ip6_isv4mapped(ip) ) {
exerr( "V6 Tracker is V6 only!" );
}
#endif
#ifdef _DEBUG
{
char *protos[] = {"TCP","UDP","UDP mcast"};
char _debug[512];
int off = snprintf( _debug, sizeof(_debug), "Binding socket type %s to address [", protos[proto] );
off += fmt_ip6c( _debug+off, ip);
snprintf( _debug + off, sizeof(_debug)-off, "]:%d...", port);
fputs( _debug, stderr );
}
#endif
if( socket_bind6_reuse( sock, ip, port, 0 ) == -1 )
panic( "socket_bind6_reuse" );
if( ( proto == FLAG_TCP ) && ( socket_listen( sock, SOMAXCONN) == -1 ) )
panic( "socket_listen" );
if( !io_fd( sock ) )
panic( "io_fd" );
io_setcookie( sock, (void*)proto );
if( (proto == FLAG_UDP) && g_udp_workers ) {
io_block( sock );
udp_init( sock, g_udp_workers );
} else
io_wantread( sock );
#ifdef _DEBUG
fputs( " success.\n", stderr);
#endif
return sock;
}
char * set_config_option( char **option, char *value ) {
#ifdef _DEBUG
fprintf( stderr, "Setting config option: %s\n", value );
#endif
while( isspace(*value) ) ++value;
free( *option );
return *option = strdup( value );
}
static int scan_ip6_port( const char *src, ot_ip6 ip, uint16 *port ) {
const char *s = src;
int off, bracket = 0;
while( isspace(*s) ) ++s;
if( *s == '[' ) ++s, ++bracket; /* for v6 style notation */
if( !(off = scan_ip6( s, ip ) ) )
return 0;
s += off;
if( bracket && *s == ']' ) ++s;
if( *s == 0 || isspace(*s)) return s-src;
if( !ip6_isv4mapped(ip)){
if( *s != ':' && *s != '.' ) return 0;
if( !bracket && *(s) == ':' ) return 0;
s++;
} else {
if( *(s++) != ':' ) return 0;
}
if( !(off = scan_ushort (s, port ) ) )
return 0;
return off+s-src;
}
int parse_configfile( char * config_filename ) {
FILE * accesslist_filehandle;
char inbuf[512];
ot_ip6 tmpip;
int bound = 0;
accesslist_filehandle = fopen( config_filename, "r" );
if( accesslist_filehandle == NULL ) {
fprintf( stderr, "Warning: Can't open config file: %s.", config_filename );
return 0;
}
while( fgets( inbuf, sizeof(inbuf), accesslist_filehandle ) ) {
char *p = inbuf;
size_t strl;
/* Skip white spaces */
while(isspace(*p)) ++p;
/* Ignore comments and empty lines */
if((*p=='#')||(*p=='\n')||(*p==0)) continue;
/* consume trailing new lines and spaces */
strl = strlen(p);
while( strl && isspace(p[strl-1]))
p[--strl] = 0;
/* Scan for commands */
if(!byte_diff(p,15,"tracker.rootdir" ) && isspace(p[15])) {
set_config_option( &g_serverdir, p+16 );
} else if(!byte_diff(p,12,"tracker.user" ) && isspace(p[12])) {
set_config_option( &g_serveruser, p+13 );
} else if(!byte_diff(p,14,"listen.tcp_udp" ) && isspace(p[14])) {
uint16_t tmpport = 6969;
if( !scan_ip6_port( p+15, tmpip, &tmpport )) goto parse_error;
ot_try_bind( tmpip, tmpport, FLAG_TCP ); ++bound;
ot_try_bind( tmpip, tmpport, FLAG_UDP ); ++bound;
} else if(!byte_diff(p,10,"listen.tcp" ) && isspace(p[10])) {
uint16_t tmpport = 6969;
if( !scan_ip6_port( p+11, tmpip, &tmpport )) goto parse_error;
ot_try_bind( tmpip, tmpport, FLAG_TCP );
++bound;
} else if(!byte_diff(p, 10, "listen.udp" ) && isspace(p[10])) {
uint16_t tmpport = 6969;
if( !scan_ip6_port( p+11, tmpip, &tmpport )) goto parse_error;
ot_try_bind( tmpip, tmpport, FLAG_UDP );
++bound;
} else if(!byte_diff(p,18,"listen.udp.workers" ) && isspace(p[18])) {
char *value = p + 18;
while( isspace(*value) ) ++value;
scan_uint( value, &g_udp_workers );
#ifdef WANT_ACCESSLIST_WHITE
} else if(!byte_diff(p, 16, "access.whitelist" ) && isspace(p[16])) {
set_config_option( &g_accesslist_filename, p+17 );
#elif defined( WANT_ACCESSLIST_BLACK )
} else if(!byte_diff(p, 16, "access.blacklist" ) && isspace(p[16])) {
set_config_option( &g_accesslist_filename, p+17 );
#endif
#ifdef WANT_RESTRICT_STATS
} else if(!byte_diff(p, 12, "access.stats" ) && isspace(p[12])) {
if( !scan_ip6( p+13, tmpip )) goto parse_error;
accesslist_blessip( tmpip, OT_PERMISSION_MAY_STAT );
#endif
} else if(!byte_diff(p, 17, "access.stats_path" ) && isspace(p[17])) {
set_config_option( &g_stats_path, p+18 );
#ifdef WANT_IP_FROM_PROXY
} else if(!byte_diff(p, 12, "access.proxy" ) && isspace(p[12])) {
if( !scan_ip6( p+13, tmpip )) goto parse_error;
accesslist_blessip( tmpip, OT_PERMISSION_MAY_PROXY );
#endif
} else if(!byte_diff(p, 20, "tracker.redirect_url" ) && isspace(p[20])) {
set_config_option( &g_redirecturl, p+21 );
#ifdef WANT_SYNC_LIVE
} else if(!byte_diff(p, 24, "livesync.cluster.node_ip" ) && isspace(p[24])) {
if( !scan_ip6( p+25, tmpip )) goto parse_error;
accesslist_blessip( tmpip, OT_PERMISSION_MAY_LIVESYNC );
} else if(!byte_diff(p, 23, "livesync.cluster.listen" ) && isspace(p[23])) {
uint16_t tmpport = LIVESYNC_PORT;
if( !scan_ip6_port( p+24, tmpip, &tmpport )) goto parse_error;
livesync_bind_mcast( tmpip, tmpport );
#endif
} else
fprintf( stderr, "Unhandled line in config file: %s\n", inbuf );
continue;
parse_error:
fprintf( stderr, "Parse error in config file: %s\n", inbuf);
}
fclose( accesslist_filehandle );
return bound;
}
void load_state(const char * const state_filename ) {
FILE * state_filehandle;
char inbuf[512];
ot_hash infohash;
unsigned long long base, downcount;
int consumed;
state_filehandle = fopen( state_filename, "r" );
if( state_filehandle == NULL ) {
fprintf( stderr, "Warning: Can't open config file: %s.", state_filename );
return;
}
/* We do ignore anything that is not of the form "^[:xdigit:]:\d+:\d+" */
while( fgets( inbuf, sizeof(inbuf), state_filehandle ) ) {
int i;
for( i=0; i<(int)sizeof(ot_hash); ++i ) {
int eger = 16 * scan_fromhex( inbuf[ 2*i ] ) + scan_fromhex( inbuf[ 1 + 2*i ] );
if( eger < 0 )
continue;
infohash[i] = eger;
}
if( i != (int)sizeof(ot_hash) ) continue;
i *= 2;
if( inbuf[ i++ ] != ':' || !( consumed = scan_ulonglong( inbuf+i, &base ) ) ) continue;
i += consumed;
if( inbuf[ i++ ] != ':' || !( consumed = scan_ulonglong( inbuf+i, &downcount ) ) ) continue;
add_torrent_from_saved_state( infohash, base, downcount );
}
fclose( state_filehandle );
}
int drop_privileges ( const char * const serveruser, const char * const serverdir ) {
struct passwd *pws = NULL;
#ifdef _DEBUG
if( !geteuid() )
fprintf( stderr, "Dropping to user %s.\n", serveruser );
if( serverdir )
fprintf( stderr, "ch%s'ing to directory %s.\n", geteuid() ? "dir" : "root", serverdir );
#endif
/* Grab pws entry before chrooting */
pws = getpwnam( serveruser );
endpwent();
if( geteuid() == 0 ) {
/* Running as root: chroot and drop privileges */
if( serverdir && chroot( serverdir ) ) {
fprintf( stderr, "Could not chroot to %s, because: %s\n", serverdir, strerror(errno) );
return -1;
}
if(chdir("/"))
panic("chdir() failed after chrooting: ");
/* If we can't find server user, revert to nobody's default uid */
if( !pws ) {
fprintf( stderr, "Warning: Could not get password entry for %s. Reverting to uid -2.\n", serveruser );
setegid( (gid_t)-2 ); setgid( (gid_t)-2 );
setuid( (uid_t)-2 ); seteuid( (uid_t)-2 );
}
else {
setegid( pws->pw_gid ); setgid( pws->pw_gid );
setuid( pws->pw_uid ); seteuid( pws->pw_uid );
}
if( geteuid() == 0 || getegid() == 0 )
panic("Still running with root privileges?!");
}
else {
/* Normal user, just chdir() */
if( serverdir && chdir( serverdir ) ) {
fprintf( stderr, "Could not chroot to %s, because: %s\n", serverdir, strerror(errno) );
return -1;
}
}
return 0;
}
int main( int argc, char **argv ) {
ot_ip6 serverip, tmpip;
int bound = 0, scanon = 1;
uint16_t tmpport;
char * statefile = 0;
memset( serverip, 0, sizeof(ot_ip6) );
#ifndef WANT_V6
serverip[10]=serverip[11]=-1;
noipv6=1;
#endif
#ifdef WANT_DEV_RANDOM
srandomdev();
#else
srandom( time(NULL) );
#endif
while( scanon ) {
switch( getopt( argc, argv, ":i:p:A:P:d:u:r:s:f:l:v"
#ifdef WANT_ACCESSLIST_BLACK
"b:"
#elif defined( WANT_ACCESSLIST_WHITE )
"w:"
#endif
"h" ) ) {
case -1 : scanon = 0; break;
case 'i':
if( !scan_ip6( optarg, serverip )) { usage( argv[0] ); exit( 1 ); }
break;
#ifdef WANT_ACCESSLIST_BLACK
case 'b': set_config_option( &g_accesslist_filename, optarg); break;
#elif defined( WANT_ACCESSLIST_WHITE )
case 'w': set_config_option( &g_accesslist_filename, optarg); break;
#endif
case 'p':
if( !scan_ushort( optarg, &tmpport)) { usage( argv[0] ); exit( 1 ); }
ot_try_bind( serverip, tmpport, FLAG_TCP ); bound++; break;
case 'P':
if( !scan_ushort( optarg, &tmpport)) { usage( argv[0] ); exit( 1 ); }
ot_try_bind( serverip, tmpport, FLAG_UDP ); bound++; break;
#ifdef WANT_SYNC_LIVE
case 's':
if( !scan_ushort( optarg, &tmpport)) { usage( argv[0] ); exit( 1 ); }
livesync_bind_mcast( serverip, tmpport); break;
#endif
case 'd': set_config_option( &g_serverdir, optarg ); break;
case 'u': set_config_option( &g_serveruser, optarg ); break;
case 'r': set_config_option( &g_redirecturl, optarg ); break;
case 'l': statefile = optarg; break;
case 'A':
if( !scan_ip6( optarg, tmpip )) { usage( argv[0] ); exit( 1 ); }
accesslist_blessip( tmpip, 0xffff ); /* Allow everything for now */
break;
case 'f': bound += parse_configfile( optarg ); break;
case 'h': help( argv[0] ); exit( 0 );
case 'v': {
char buffer[8192];
stats_return_tracker_version( buffer );
fputs( buffer, stderr );
exit( 0 );
}
default:
case '?': usage( argv[0] ); exit( 1 );
}
}
/* Bind to our default tcp/udp ports */
if( !bound) {
ot_try_bind( serverip, 6969, FLAG_TCP );
ot_try_bind( serverip, 6969, FLAG_UDP );
}
#ifdef WANT_SYSLOGS
openlog( "opentracker", 0, LOG_USER );
setlogmask(LOG_UPTO(LOG_INFO));
#endif
if( drop_privileges( g_serveruser ? g_serveruser : "nobody", g_serverdir ) == -1 )
panic( "drop_privileges failed, exiting. Last error");
g_now_seconds = time( NULL );
/* Create our self pipe which allows us to interrupt mainloops
io_wait in case some data is available to send out */
if( pipe( g_self_pipe ) == -1 )
panic( "selfpipe failed: " );
if( !io_fd( g_self_pipe[0] ) )
panic( "selfpipe io_fd failed: " );
io_setcookie( g_self_pipe[0], (void*)FLAG_SELFPIPE );
io_wantread( g_self_pipe[0] );
defaul_signal_handlers( );
/* Init all sub systems. This call may fail with an exit() */
trackerlogic_init( );
if( statefile )
load_state( statefile );
install_signal_handlers( );
if( !g_udp_workers )
udp_init( -1, 0 );
/* Kick off our initial clock setting alarm */
alarm(5);
server_mainloop( 0 );
return 0;
}
const char *g_version_opentracker_c = "$Source: /home/cvsroot/opentracker/opentracker.c,v $: $Revision: 1.239 $\n";