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transmission/libtransmission/net.c

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/******************************************************************************
*
* $Id$
*
* Copyright (c) 2005-2008 Transmission authors and contributors
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*****************************************************************************/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <sys/types.h>
#ifdef WIN32
#define _WIN32_WINNT 0x0501
#include <ws2tcpip.h>
#else
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h> /* inet_addr */
#include <netdb.h>
#include <fcntl.h>
#endif
#include <unistd.h>
#include <stdarg.h> /* some 1.4.x versions of evutil.h need this */
#include <evutil.h>
#include "transmission.h"
#include "fdlimit.h"
#include "natpmp.h"
#include "net.h"
#include "peer-io.h"
#include "platform.h"
#include "session.h"
#include "utils.h"
#ifndef IN_MULTICAST
#define IN_MULTICAST( a ) ( ( ( a ) & 0xf0000000 ) == 0xe0000000 )
#endif
const tr_address tr_in6addr_any = { TR_AF_INET6, { IN6ADDR_ANY_INIT } };
const tr_address tr_inaddr_any = { TR_AF_INET, { { { { INADDR_ANY, 0x00, 0x00, 0x00 } } } } };
#ifdef WIN32
const char *
inet_ntop( int af, const void * src, char * dst, socklen_t cnt )
{
if (af == AF_INET)
{
struct sockaddr_in in;
memset( &in, 0, sizeof( in ) );
in.sin_family = AF_INET;
memcpy( &in.sin_addr, src, sizeof( struct in_addr ) );
getnameinfo((struct sockaddr *)&in, sizeof(struct sockaddr_in),
dst, cnt, NULL, 0, NI_NUMERICHOST);
return dst;
}
else if (af == AF_INET6)
{
struct sockaddr_in6 in;
memset( &in, 0, sizeof( in ) );
in.sin6_family = AF_INET6;
memcpy( &in.sin6_addr, src, sizeof( struct in_addr6 ) );
getnameinfo((struct sockaddr *)&in, sizeof(struct sockaddr_in6),
dst, cnt, NULL, 0, NI_NUMERICHOST);
return dst;
}
return NULL;
}
int
inet_pton( int af, const char * src, void * dst )
{
struct addrinfo hints, *res, *ressave;
struct sockaddr_in * s4;
struct sockaddr_in6 * s6;
memset( &hints, 0, sizeof( struct addrinfo ));
hints.ai_family = af;
hints.ai_flags = AI_NUMERICHOST;
if( getaddrinfo( src, NULL, &hints, &res ) ) {
if( WSAGetLastError() == WSAHOST_NOT_FOUND )
return 0;
else {
errno = EAFNOSUPPORT;
return -1;
}
}
ressave = res;
while( res ) {
switch (res->ai_family) {
case AF_INET:
s4 = (struct sockaddr_in *) res->ai_addr;
memcpy( dst, &s4->sin_addr, sizeof( struct in_addr ) );
break;
case AF_INET6:
s6 = (struct sockaddr_in6 *) res->ai_addr;
memcpy( dst, &s6->sin6_addr, sizeof( struct in6_addr ) );
break;
default: /* AF_UNSPEC, AF_NETBIOS */
break;
}
res = res->ai_next;
}
freeaddrinfo(ressave);
return 1;
}
#endif
void
tr_netInit( void )
{
static int initialized = FALSE;
if( !initialized )
{
#ifdef WIN32
WSADATA wsaData;
WSAStartup( MAKEWORD( 2, 2 ), &wsaData );
#endif
initialized = TRUE;
}
}
char *
tr_net_strerror( char * buf, size_t buflen, int err )
{
*buf = '\0';
#ifdef WIN32
FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM, NULL, err, 0, buf, buflen, NULL );
#else
tr_strlcpy( buf, tr_strerror( err ), buflen );
#endif
return buf;
}
const char *
tr_ntop( const tr_address * src, char * dst, int size )
{
assert( tr_isAddress( src ) );
if( src->type == TR_AF_INET )
return inet_ntop( AF_INET, &src->addr, dst, size );
else
return inet_ntop( AF_INET6, &src->addr, dst, size );
}
/*
* Non-threadsafe version of tr_ntop, which uses a static memory area for a buffer.
* This function is suitable to be called from libTransmission's networking code,
* which is single-threaded.
*/
const char *
tr_ntop_non_ts( const tr_address * src )
{
static char buf[INET6_ADDRSTRLEN];
return tr_ntop( src, buf, sizeof( buf ) );
}
tr_address *
tr_pton( const char * src, tr_address * dst )
{
int retval = inet_pton( AF_INET, src, &dst->addr );
assert( dst );
if( retval < 0 )
return NULL;
else if( retval == 0 )
retval = inet_pton( AF_INET6, src, &dst->addr );
else
{
dst->type = TR_AF_INET;
return dst;
}
if( retval < 1 )
return NULL;
dst->type = TR_AF_INET6;
return dst;
}
/*
* Compare two tr_address structures.
* Returns:
* <0 if a < b
* >0 if a > b
* 0 if a == b
*/
int
tr_compareAddresses( const tr_address * a, const tr_address * b)
{
static const int sizes[2] = { sizeof(struct in_addr), sizeof(struct in6_addr) };
/* IPv6 addresses are always "greater than" IPv4 */
if( a->type != b->type )
return a->type == TR_AF_INET ? 1 : -1;
return memcmp( &a->addr, &b->addr, sizes[a->type] );
}
/***********************************************************************
* TCP sockets
**********************************************************************/
int
tr_netSetTOS( int s, int tos )
{
#ifdef IP_TOS
return setsockopt( s, IPPROTO_IP, IP_TOS, (char*)&tos, sizeof( tos ) );
#else
return 0;
#endif
}
int
tr_netSetCongestionControl( int s, const char *algorithm )
{
#ifdef TCP_CONGESTION
return setsockopt( s, IPPROTO_TCP, TCP_CONGESTION,
algorithm, strlen(algorithm) + 1 );
#else
errno = ENOSYS;
return -1;
#endif
}
static socklen_t
setup_sockaddr( const tr_address * addr,
tr_port port,
struct sockaddr_storage * sockaddr)
{
assert( tr_isAddress( addr ) );
if( addr->type == TR_AF_INET )
{
struct sockaddr_in sock4;
memset( &sock4, 0, sizeof( sock4 ) );
sock4.sin_family = AF_INET;
sock4.sin_addr.s_addr = addr->addr.addr4.s_addr;
sock4.sin_port = port;
memcpy( sockaddr, &sock4, sizeof( sock4 ) );
return sizeof( struct sockaddr_in );
}
else
{
struct sockaddr_in6 sock6;
memset( &sock6, 0, sizeof( sock6 ) );
sock6.sin6_family = AF_INET6;
sock6.sin6_port = port;
sock6.sin6_flowinfo = 0;
sock6.sin6_addr = addr->addr.addr6;
memcpy( sockaddr, &sock6, sizeof( sock6 ) );
return sizeof( struct sockaddr_in6 );
}
}
int
tr_netOpenPeerSocket( tr_session * session,
const tr_address * addr,
tr_port port,
tr_bool clientIsSeed )
{
static const int domains[NUM_TR_AF_INET_TYPES] = { AF_INET, AF_INET6 };
int s;
struct sockaddr_storage sock;
socklen_t addrlen;
const tr_address * source_addr;
socklen_t sourcelen;
struct sockaddr_storage source_sock;
assert( tr_isAddress( addr ) );
if( !tr_isValidPeerAddress( addr, port ) )
return -EINVAL;
s = tr_fdSocketCreate( session, domains[addr->type], SOCK_STREAM );
if( s < 0 )
return -1;
/* seeds don't need much of a read buffer... */
if( clientIsSeed ) {
int n = 8192;
if( setsockopt( s, SOL_SOCKET, SO_RCVBUF, &n, sizeof(n) ) )
tr_inf( "Unable to set SO_RCVBUF on socket %d: %s", s, tr_strerror( sockerrno ) );
}
if( evutil_make_socket_nonblocking( s ) < 0 ) {
tr_netClose( session, s );
return -1;
}
addrlen = setup_sockaddr( addr, port, &sock );
/* set source address */
source_addr = tr_sessionGetPublicAddress( session, addr->type );
assert( source_addr );
sourcelen = setup_sockaddr( source_addr, 0, &source_sock );
if( bind( s, ( struct sockaddr * ) &source_sock, sourcelen ) )
{
tr_err( _( "Couldn't set source address %s on %d: %s" ),
tr_ntop_non_ts( source_addr ), s, tr_strerror( errno ) );
return -errno;
}
if( ( connect( s, (struct sockaddr *) &sock,
addrlen ) < 0 )
#ifdef WIN32
&& ( sockerrno != WSAEWOULDBLOCK )
#endif
&& ( sockerrno != EINPROGRESS ) )
{
int tmperrno;
tmperrno = sockerrno;
if( ( tmperrno != ENETUNREACH && tmperrno != EHOSTUNREACH )
|| addr->type == TR_AF_INET )
tr_err( _( "Couldn't connect socket %d to %s, port %d (errno %d - %s)" ),
s, tr_ntop_non_ts( addr ), (int)port, tmperrno,
tr_strerror( tmperrno ) );
tr_netClose( session, s );
s = -tmperrno;
}
tr_deepLog( __FILE__, __LINE__, NULL, "New OUTGOING connection %d (%s)",
s, tr_peerIoAddrStr( addr, port ) );
return s;
}
static int
tr_netBindTCPImpl( const tr_address * addr, tr_port port, tr_bool suppressMsgs, int * errOut )
{
static const int domains[NUM_TR_AF_INET_TYPES] = { AF_INET, AF_INET6 };
struct sockaddr_storage sock;
int fd;
int addrlen;
int optval;
assert( tr_isAddress( addr ) );
fd = socket( domains[addr->type], SOCK_STREAM, 0 );
if( fd < 0 ) {
*errOut = sockerrno;
return -1;
}
if( evutil_make_socket_nonblocking( fd ) < 0 ) {
*errOut = sockerrno;
tr_netCloseSocket( fd );
return -1;
}
optval = 1;
setsockopt( fd, SOL_SOCKET, SO_KEEPALIVE, &optval, sizeof(optval) );
setsockopt( fd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval) );
#ifdef IPV6_V6ONLY
if( addr->type == TR_AF_INET6 )
if( setsockopt( fd, IPPROTO_IPV6, IPV6_V6ONLY, &optval, sizeof( optval ) ) == -1 )
if( sockerrno != ENOPROTOOPT ) { /* if the kernel doesn't support it, ignore it */
*errOut = sockerrno;
return -1;
}
#endif
addrlen = setup_sockaddr( addr, htons( port ), &sock );
if( bind( fd, (struct sockaddr *) &sock, addrlen ) ) {
const int err = sockerrno;
if( !suppressMsgs )
{
const char * fmt;
const char * hint;
if( err == EADDRINUSE )
hint = _( "Is another copy of Transmission already running?" );
else
hint = NULL;
if( hint == NULL )
fmt = _( "Couldn't bind port %d on %s: %s" );
else
fmt = _( "Couldn't bind port %d on %s: %s (%s)" );
tr_err( fmt, port, tr_ntop_non_ts( addr ), tr_strerror( err ), hint );
}
tr_netCloseSocket( fd );
*errOut = err;
return -1;
}
if( !suppressMsgs )
tr_dbg( "Bound socket %d to port %d on %s", fd, port, tr_ntop_non_ts( addr ) );
if( listen( fd, 128 ) == -1 ) {
*errOut = sockerrno;
tr_netCloseSocket( fd );
return -1;
}
return fd;
}
int
tr_netBindTCP( const tr_address * addr, tr_port port, tr_bool suppressMsgs )
{
int unused;
return tr_netBindTCPImpl( addr, port, suppressMsgs, &unused );
}
tr_bool
tr_net_hasIPv6( tr_port port )
{
static tr_bool result = FALSE;
static tr_bool alreadyDone = FALSE;
if( !alreadyDone )
{
int err;
int fd = tr_netBindTCPImpl( &tr_in6addr_any, port, TRUE, &err );
if( fd >= 0 || err != EAFNOSUPPORT ) /* we support ipv6 */
result = TRUE;
if( fd >= 0 )
tr_netCloseSocket( fd );
alreadyDone = TRUE;
}
return result;
}
int
tr_netAccept( tr_session * session,
int b,
tr_address * addr,
tr_port * port )
{
int fd = tr_fdSocketAccept( session, b, addr, port );
if( fd>=0 && evutil_make_socket_nonblocking(fd)<0 ) {
tr_netClose( session, fd );
fd = -1;
}
return fd;
}
void
tr_netCloseSocket( int fd )
{
EVUTIL_CLOSESOCKET( fd );
}
void
tr_netClose( tr_session * session, int s )
{
tr_fdSocketClose( session, s );
}
/*
get_source_address() and global_unicast_address() were written by
Juliusz Chroboczek, and are covered under the same license as dht.c.
Please feel free to copy them into your software if it can help
unbreaking the double-stack Internet. */
/* Get the source address used for a given destination address. Since
there is no official interface to get this information, we create
a connected UDP socket (connected UDP... hmm...) and check its source
address. */
static int
get_source_address( const struct sockaddr * dst,
socklen_t dst_len,
struct sockaddr * src,
socklen_t * src_len )
{
int s, rc, save;
s = socket(dst->sa_family, SOCK_DGRAM, 0);
if(s < 0)
goto fail;
/* Since it's a UDP socket, this doesn't actually send any packets. */
rc = connect(s, dst, dst_len);
if(rc < 0)
goto fail;
rc = getsockname(s, src, src_len);
if(rc < 0)
goto fail;
EVUTIL_CLOSESOCKET( s );
return rc;
fail:
save = errno;
EVUTIL_CLOSESOCKET( s );
errno = save;
return -1;
}
/* We all hate NATs. */
static int
global_unicast_address(struct sockaddr *sa)
{
if(sa->sa_family == AF_INET) {
const unsigned char *a =
(unsigned char*)&((struct sockaddr_in*)sa)->sin_addr;
if(a[0] == 0 || a[0] == 127 || a[0] >= 224 ||
a[0] == 10 || (a[0] == 172 && a[1] >= 16 && a[1] <= 31) ||
(a[0] == 192 && a[1] == 168))
return 0;
return 1;
} else if(sa->sa_family == AF_INET6) {
const unsigned char *a =
(unsigned char*)&((struct sockaddr_in6*)sa)->sin6_addr;
/* 2000::/3 */
return (a[0] & 0xE0) == 0x20;
} else {
errno = EAFNOSUPPORT;
return -1;
}
}
static int
tr_globalAddress( int af, void *addr, int *addr_len )
{
struct sockaddr_storage ss;
socklen_t sslen = sizeof(ss);
struct sockaddr_in sin;
struct sockaddr_in6 sin6;
struct sockaddr *sa;
socklen_t salen;
int rc;
switch(af) {
case AF_INET:
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
inet_pton(AF_INET, "91.121.74.28", &sin.sin_addr);
sin.sin_port = htons(6969);
sa = (struct sockaddr*)&sin;
salen = sizeof(sin);
break;
case AF_INET6:
memset(&sin6, 0, sizeof(sin6));
sin6.sin6_family = AF_INET6;
/* In order for address selection to work right, this should be
a native IPv6 address, not Teredo or 6to4. */
inet_pton(AF_INET6, "2001:1890:1112:1::20", &sin6.sin6_addr);
sin6.sin6_port = htons(6969);
sa = (struct sockaddr*)&sin6;
salen = sizeof(sin6);
break;
default:
return -1;
}
rc = get_source_address( sa, salen, (struct sockaddr*)&ss, &sslen );
if( rc < 0 )
return -1;
if( !global_unicast_address( (struct sockaddr*)&ss) )
return -1;
switch(af) {
case AF_INET:
if(*addr_len < 4)
return -1;
memcpy(addr, &((struct sockaddr_in*)&ss)->sin_addr, 4);
*addr_len = 4;
return 1;
case AF_INET6:
if(*addr_len < 16)
return -1;
memcpy(addr, &((struct sockaddr_in6*)&ss)->sin6_addr, 16);
*addr_len = 16;
return 1;
default:
return -1;
}
}
/* Return our global IPv6 address, with caching. */
const unsigned char *
tr_globalIPv6( void )
{
static unsigned char ipv6[16];
static time_t last_time = 0;
static int have_ipv6 = 0;
const time_t now = tr_time( );
/* Re-check every half hour */
if( last_time < now - 1800 )
{
int addrlen = 16;
const int rc = tr_globalAddress( AF_INET6, ipv6, &addrlen );
have_ipv6 = ( rc >= 0 ) && ( addrlen == 16 );
last_time = now;
}
return have_ipv6 ? ipv6 : NULL;
}
/***
****
****
***/
static tr_bool
isIPv4MappedAddress( const tr_address * addr )
{
return ( addr->type == TR_AF_INET6 ) && IN6_IS_ADDR_V4MAPPED( &addr->addr.addr6 );
}
static tr_bool
isIPv6LinkLocalAddress( const tr_address * addr )
{
return ( ( addr->type == TR_AF_INET6 )
&& IN6_IS_ADDR_LINKLOCAL( &addr->addr.addr6 ) );
}
/* isMartianAddr was written by Juliusz Chroboczek,
and is covered under the same license as third-party/dht/dht.c. */
static tr_bool
isMartianAddr( const struct tr_address * a )
{
static const unsigned char zeroes[16] =
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
assert( tr_isAddress( a ) );
switch( a->type )
{
case TR_AF_INET: {
const unsigned char * address = (const unsigned char*)&a->addr.addr4;
return (address[0] == 0) ||
(address[0] == 127) ||
((address[0] & 0xE0) == 0xE0);
break;
}
case TR_AF_INET6: {
const unsigned char * address = (const unsigned char*)&a->addr.addr6;
return (address[0] == 0xFF) ||
(memcmp(address, zeroes, 15) == 0 &&
(address[15] == 0 || address[15] == 1)) ||
/* Addresses outside of 2000::/3 are currently reserved,
but might be allocated at some future time. Since
there are a lot of buggy peers pushing around such
addresses over PEX, we reject them until the end of
the 13th Baktun. */
(tr_time() < 1356130800 && (address[0] & 0xE0) != 0x20);
break;
}
default:
return TRUE;
}
}
tr_bool
tr_isValidPeerAddress( const tr_address * addr, tr_port port )
{
return ( port != 0 )
&& ( tr_isAddress( addr ) )
&& ( !isIPv6LinkLocalAddress( addr ) )
&& ( !isIPv4MappedAddress( addr ) )
&& ( !isMartianAddr( addr ) );
}
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