xwords/xwords4/linux/relaycon.c
Eric House a6784464ff first set of networking changes testing per-device communication with
relay on behalf of a number of games.  Works as long as all the games
are open.
2013-01-16 06:46:33 -08:00

193 lines
6.2 KiB
C

/* -*- compile-command: "make MEMDEBUG=TRUE -j3"; -*- */
/*
* Copyright 2013 by Eric House (xwords@eehouse.org). All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <netdb.h>
#include <errno.h>
#include "relaycon.h"
#include "comtypes.h"
typedef struct _RelayConStorage {
int socket;
RelayConnProcs procs;
void* procsClosure;
} RelayConStorage;
static RelayConStorage* getStorage( LaunchParams* params );
static void addressToServer( struct sockaddr_in* to, const CommsAddrRec* addr );
static XP_U32 addrForHost( const CommsAddrRec* addr );
static XP_U32 hostNameToIP( const XP_UCHAR* name );
static void relaycon_receive( void* closure, int socket );
void
relaycon_init( LaunchParams* params, const RelayConnProcs* procs,
void* procsClosure, const char* host, int port,
const XP_UCHAR* devID, DevIDType typ )
{
XP_ASSERT( !params->relayConStorage );
RelayConStorage* storage = getStorage( params );
XP_MEMCPY( &storage->procs, procs, sizeof(storage->procs) );
storage->procsClosure = procsClosure;
storage->socket = socket( AF_INET, SOCK_DGRAM, IPPROTO_UDP );
(*params->socketChanged)( params, storage->socket, -1,
relaycon_receive, params );
XP_ASSERT( !!devID );
XP_U16 idLen = XP_STRLEN( devID );
XP_U16 lenNBO = XP_HTONS( idLen );
XP_U8 tmpbuf[1 + 1 + 1 + sizeof(lenNBO) + idLen];
tmpbuf[0] = XWREG_PROTO_VERSION;
tmpbuf[1] = XWRREG_REG;
tmpbuf[2] = typ;
XP_MEMCPY( &tmpbuf[3], &lenNBO, sizeof(lenNBO) );
XP_MEMCPY( &tmpbuf[5], devID, idLen );
struct sockaddr_in to = {0};
to.sin_family = PF_INET;
to.sin_addr.s_addr = htonl( hostNameToIP(host) );
to.sin_port = htons(port);
(void)sendto( storage->socket, tmpbuf, sizeof(tmpbuf), 0, /* flags */
(struct sockaddr*)&to, sizeof(to) );
}
XP_S16
relaycon_send( LaunchParams* params, const XP_U8* buf, XP_U16 buflen,
XP_U32 gameToken, const CommsAddrRec* addrRec )
{
ssize_t nSent = -1;
RelayConStorage* storage = getStorage( params );
struct sockaddr_in to = {0};
addressToServer( &to, addrRec );
XP_U8 tmpbuf[1 + 1 + sizeof(gameToken) + buflen];
tmpbuf[0] = XWREG_PROTO_VERSION;
tmpbuf[1] = XWRREG_MSG;
XP_U32 inNBO = htonl(gameToken);
XP_MEMCPY( &tmpbuf[2], &inNBO, sizeof(inNBO) );
XP_MEMCPY( &tmpbuf[1 + 1 + sizeof(gameToken)], buf, buflen );
nSent = sendto( storage->socket, tmpbuf, sizeof(tmpbuf), 0, /* flags */
(struct sockaddr*)&to, sizeof(to) );
if ( 1 + 1 + sizeof(gameToken) < nSent ) {
nSent -= 1 + 1 + sizeof(gameToken);
}
LOG_RETURNF( "%d", nSent );
return nSent;
}
static void
relaycon_receive( void* closure, int socket )
{
LaunchParams* params = (LaunchParams*)closure;
XP_ASSERT( !!params->relayConStorage );
RelayConStorage* storage = getStorage( params );
XP_U8 buf[512];
struct sockaddr_in from;
socklen_t fromlen = sizeof(from);
XP_LOGF( "%s: calling recvfrom on socket %d", __func__, socket );
ssize_t nRead = recvfrom( socket, buf, sizeof(buf), 0, /* flags */
(struct sockaddr*)&from, &fromlen );
XP_LOGF( "%s: read %d bytes", __func__, nRead );
if ( 0 <= nRead ) {
XP_U8* ptr = buf;
const XP_U8* end = buf + nRead;
XP_ASSERT( XWREG_PROTO_VERSION == *ptr++ );
XWRelayReg cmd = *ptr++;
switch( cmd ) {
case XWRREG_REGRSP: {
XP_U16 len;
XP_MEMCPY( &len, ptr, sizeof(len) );
len = ntohs( len );
ptr += sizeof( len );
XP_UCHAR devID[len+1];
XP_MEMCPY( devID, ptr, len );
devID[len] = '\0';
(*storage->procs.devIDChanged)( storage->procsClosure, devID );
}
break;
case XWRREG_MSG:
(*storage->procs.msgReceived)( storage->procsClosure,
ptr, end - ptr );
break;
default:
XP_LOGF( "%s: Unexpected cmd %d", __func__, cmd );
XP_ASSERT( 0 );
}
} else {
XP_LOGF( "%s: error reading udp socket: %d (%s)", __func__,
errno, strerror(errno) );
}
}
void
relaycon_cleanup( LaunchParams* params )
{
XP_FREEP( params->mpool, &params->relayConStorage );
}
static RelayConStorage*
getStorage( LaunchParams* params )
{
RelayConStorage* storage = (RelayConStorage*)params->relayConStorage;
if ( NULL == storage ) {
storage = XP_CALLOC( params->mpool, sizeof(*storage) );
storage->socket = -1;
params->relayConStorage = storage;
}
return storage;
}
static void
addressToServer( struct sockaddr_in* to, const CommsAddrRec* addr )
{
to->sin_family = PF_INET;
to->sin_addr.s_addr = htonl( addrForHost(addr) );
to->sin_port = htons(addr->u.ip_relay.port);
}
static XP_U32
addrForHost( const CommsAddrRec* addr )
{
XP_U32 ip = addr->u.ip_relay.ipAddr;
if ( 0L == ip ) {
ip = hostNameToIP( addr->u.ip_relay.hostName );
}
return ip;
} /* addrForHost */
static XP_U32
hostNameToIP( const XP_UCHAR* name )
{
XP_U32 ip;
struct hostent* host;
XP_LOGF( "%s: looking up %s", __func__, name );
host = gethostbyname( name );
if ( NULL == host ) {
XP_WARNF( "gethostbyname returned NULL\n" );
} else {
XP_MEMCPY( &ip, host->h_addr_list[0], sizeof(ip) );
ip = ntohl(ip);
}
XP_LOGF( "%s found %lx for %s", __func__, ip, name );
return ip;
}