/****************************************************************************** * * $Id$ * * Copyright (c) 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 #include #include #include #ifdef WIN32 #define _WIN32_WINNT 0x0501 #include #else #include /* TCP_CONGESTION */ #endif #include #include #include "transmission.h" #include "fdlimit.h" /* tr_fdSocketClose() */ #include "net.h" #include "peer-io.h" /* tr_peerIoAddrStr() FIXME this should be moved to net.h */ #include "session.h" /* tr_sessionGetPublicAddress() */ #include "tr-utp.h" /* tr_utpSendTo() */ #include "utils.h" /* tr_time(), tr_dbg() */ #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 } } } } }; 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_address_to_string_with_buf( const tr_address * addr, char * buf, size_t buflen ) { assert( tr_address_is_valid( addr ) ); if( addr->type == TR_AF_INET ) return evutil_inet_ntop( AF_INET, &addr->addr, buf, buflen ); else return evutil_inet_ntop( AF_INET6, &addr->addr, buf, buflen ); } /* * Non-threadsafe version of tr_address_to_string_with_buf() * and 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_address_to_string( const tr_address * addr ) { static char buf[INET6_ADDRSTRLEN]; return tr_address_to_string_with_buf( addr, buf, sizeof( buf ) ); } bool tr_address_from_string( tr_address * dst, const char * src ) { bool ok; if(( ok = evutil_inet_pton( AF_INET, src, &dst->addr ) == 1 )) dst->type = TR_AF_INET; if( !ok ) /* try IPv6 */ if(( ok = evutil_inet_pton( AF_INET6, src, &dst->addr ) == 1 )) dst->type = TR_AF_INET6; return ok; } /* * Compare two tr_address structures. * Returns: * <0 if a < b * >0 if a > b * 0 if a == b */ int tr_address_compare( 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 UNUSED, const char *algorithm UNUSED ) { #ifdef TCP_CONGESTION return setsockopt( s, IPPROTO_TCP, TCP_CONGESTION, algorithm, strlen(algorithm) + 1 ); #else errno = ENOSYS; return -1; #endif } bool tr_address_from_sockaddr_storage( tr_address * setme_addr, tr_port * setme_port, const struct sockaddr_storage * from ) { if( from->ss_family == AF_INET ) { struct sockaddr_in * sin = (struct sockaddr_in *)from; setme_addr->type = TR_AF_INET; setme_addr->addr.addr4.s_addr = sin->sin_addr.s_addr; *setme_port = sin->sin_port; return true; } if( from->ss_family == AF_INET6 ) { struct sockaddr_in6 *sin6 = (struct sockaddr_in6*) from; setme_addr->type = TR_AF_INET6; setme_addr->addr.addr6 = sin6->sin6_addr; *setme_port = sin6->sin6_port; return true; } return false; } static socklen_t setup_sockaddr( const tr_address * addr, tr_port port, struct sockaddr_storage * sockaddr) { assert( tr_address_is_valid( 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, 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_address_is_valid( addr ) ); if( !tr_address_is_valid_for_peers( 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, NULL ); 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_address_to_string( 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_address_to_string( addr ), (int)ntohs( 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; } struct UTPSocket * tr_netOpenPeerUTPSocket( tr_session * session, const tr_address * addr, tr_port port, bool clientIsSeed UNUSED ) { struct sockaddr_storage ss; socklen_t sslen; sslen = setup_sockaddr( addr, port, &ss ); return UTP_Create( tr_utpSendTo, (void*)session, (struct sockaddr*)&ss, sslen ); } static int tr_netBindTCPImpl( const tr_address * addr, tr_port port, 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_address_is_valid( 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_address_to_string( 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_address_to_string( 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, bool suppressMsgs ) { int unused; return tr_netBindTCPImpl( addr, port, suppressMsgs, &unused ); } bool tr_net_hasIPv6( tr_port port ) { static bool result = false; static 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; evutil_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. */ evutil_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 bool isIPv4MappedAddress( const tr_address * addr ) { return ( addr->type == TR_AF_INET6 ) && IN6_IS_ADDR_V4MAPPED( &addr->addr.addr6 ); } static 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 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_address_is_valid( 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; } } bool tr_address_is_valid_for_peers( const tr_address * addr, tr_port port ) { return ( port != 0 ) && ( tr_address_is_valid( addr ) ) && ( !isIPv6LinkLocalAddress( addr ) ) && ( !isIPv4MappedAddress( addr ) ) && ( !isMartianAddr( addr ) ); }