transmission/libtransmission/blocklist.c

267 lines
5.4 KiB
C

/*
* This file Copyright (C) 2008 Charles Kerr <charles@rebelbase.com>
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2(b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id:$
*/
#include <stdio.h>
#include <stdlib.h> /* free */
#include <string.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "ggets.h"
#include "transmission.h"
#include "blocklist.h"
#include "net.h" /* tr_netResolve() */
#include "utils.h"
/***
**** PRIVATE
***/
struct tr_ip_range
{
uint32_t begin;
uint32_t end;
};
struct tr_blocklist
{
unsigned int isEnabled : 1;
int fd;
size_t ruleCount;
size_t byteCount;
char * filename;
struct tr_ip_range * rules;
};
static void
blocklistClose( tr_blocklist * b )
{
if( b->rules )
{
munmap( b->rules, b->byteCount );
close( b->fd );
b->rules = NULL;
b->ruleCount = 0;
b->byteCount = 0;
b->fd = -1;
}
}
static void
blocklistLoad( tr_blocklist * b )
{
int fd;
struct stat st;
const char * err_fmt = _( "Couldn't read \"%1$s\": %2$s" );
blocklistClose( b );
if( stat( b->filename, &st ) == -1 )
return;
fd = open( b->filename, O_RDONLY );
if( fd == -1 ) {
tr_err( err_fmt, b->filename, tr_strerror(errno) );
return;
}
b->rules = mmap( 0, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0 );
if( !b->rules ) {
tr_err( err_fmt, b->filename, tr_strerror(errno) );
close( fd );
return;
}
b->byteCount = st.st_size;
b->ruleCount = st.st_size / sizeof( struct tr_ip_range );
b->fd = fd;
tr_inf( _( "Blocklist contains %'d entries" ), b->ruleCount );
}
static void
blocklistEnsureLoaded( tr_blocklist * b )
{
if( !b->rules )
blocklistLoad( b );
}
static int
compareAddressToRange( const void * va, const void * vb )
{
const uint32_t * a = va;
const struct tr_ip_range * b = vb;
if( *a < b->begin ) return -1;
if( *a > b->end ) return 1;
return 0;
}
static void
blocklistDelete( tr_blocklist * b )
{
blocklistClose( b );
unlink( b->filename );
}
/***
**** PACKAGE-VISIBLE
***/
tr_blocklist *
_tr_blocklistNew( const char * filename, int isEnabled )
{
tr_blocklist * b;
b = tr_new0( tr_blocklist, 1 );
b->fd = -1;
b->filename = tr_strdup( filename );
b->isEnabled = isEnabled;
return b;
}
void
_tr_blocklistFree( tr_blocklist * b )
{
blocklistClose( b );
tr_free( b->filename );
tr_free( b );
}
int
_tr_blocklistGetRuleCount( tr_blocklist * b )
{
blocklistEnsureLoaded( b );
return b->ruleCount;
}
int
_tr_blocklistIsEnabled( tr_blocklist * b )
{
return b->isEnabled;
}
void
_tr_blocklistSetEnabled( tr_blocklist * b, int isEnabled )
{
b->isEnabled = isEnabled ? 1 : 0;
}
int
_tr_blocklistHasAddress( tr_blocklist * b, const struct in_addr * addr )
{
uint32_t needle;
const struct tr_ip_range * range;
if( !b->isEnabled )
return 0;
blocklistEnsureLoaded( b );
if( !b->rules )
return 0;
needle = ntohl( addr->s_addr );
range = bsearch( &needle,
b->rules,
b->ruleCount,
sizeof( struct tr_ip_range ),
compareAddressToRange );
return range != NULL;
}
int
_tr_blocklistExists( const tr_blocklist * b )
{
struct stat st;
return !stat( b->filename, &st );
}
int
_tr_blocklistSetContent( tr_blocklist * b,
const char * filename )
{
FILE * in;
FILE * out;
char * line;
int lineCount = 0;
const char * err_fmt = _( "Couldn't read \"%1$s\": %2$s" );
if( !filename ) {
blocklistDelete( b );
return 0;
}
in = fopen( filename, "r" );
if( !in ) {
tr_err( err_fmt, filename, tr_strerror(errno) );
return 0;
}
blocklistClose( b );
out = fopen( b->filename, "wb+" );
if( !out ) {
tr_err( err_fmt, b->filename, tr_strerror( errno ) );
fclose( in );
return 0;
}
while( !fggets( &line, in ) )
{
char * rangeBegin;
char * rangeEnd;
struct in_addr in_addr;
struct tr_ip_range range;
rangeBegin = strrchr( line, ':' );
if( !rangeBegin ) { free(line); continue; }
++rangeBegin;
rangeEnd = strchr( rangeBegin, '-' );
if( !rangeEnd ) { free(line); continue; }
*rangeEnd++ = '\0';
if( tr_netResolve( rangeBegin, &in_addr ) )
tr_err( "blocklist skipped invalid address [%s]\n", rangeBegin );
range.begin = ntohl( in_addr.s_addr );
if( tr_netResolve( rangeEnd, &in_addr ) )
tr_err( "blocklist skipped invalid address [%s]\n", rangeEnd );
range.end = ntohl( in_addr.s_addr );
free( line );
if( fwrite( &range, sizeof(struct tr_ip_range), 1, out ) != 1 ) {
tr_err( _( "Couldn't save file \"%1$s\": %2$s" ), b->filename, tr_strerror( errno ) );
break;
}
++lineCount;
}
tr_inf( _( "Blocklist updated with %'d entries" ), lineCount );
fclose( out );
fclose( in );
blocklistLoad( b );
return lineCount;
}