xwords/xwords4/linux/relaycon.c
Eric House d8a4b5ce29 include udp maxInterval, the number of seconds the relay's configured
to assume an address is still good when it hasn't heard from it, in
reg response reply, send that reply always, and read and log the new
field on clients.  It will eventually be used to implement a
keepalive.
2013-07-29 07:27:30 -07:00

392 lines
12 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 <stdbool.h>
#include "relaycon.h"
#include "comtypes.h"
typedef struct _RelayConStorage {
int socket;
RelayConnProcs procs;
void* procsClosure;
struct sockaddr_in saddr;
uint32_t nextID;
} RelayConStorage;
typedef struct _MsgHeader {
XWRelayReg cmd;
uint32_t packetID;
} MsgHeader;
static RelayConStorage* getStorage( LaunchParams* params );
static XP_U32 hostNameToIP( const XP_UCHAR* name );
static void relaycon_receive( void* closure, int socket );
static ssize_t sendIt( RelayConStorage* storage, const XP_U8* msgbuf, XP_U16 len );
static size_t addStrWithLength( XP_U8* buf, XP_U8* end, const XP_UCHAR* str );
static void getNetString( const XP_U8** ptr, XP_U16 len, XP_UCHAR* buf );
static XP_U16 getNetShort( const XP_U8** ptr );
static XP_U32 getNetLong( const XP_U8** ptr );
static int writeHeader( RelayConStorage* storage, XP_U8* dest, XWRelayReg cmd );
static bool readHeader( const XP_U8** buf, MsgHeader* header );
static size_t writeDevID( XP_U8* buf, size_t len, const XP_UCHAR* str );
void
relaycon_init( LaunchParams* params, const RelayConnProcs* procs,
void* procsClosure, const char* host, int port )
{
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 );
(*procs->socketChanged)( procsClosure, storage->socket, -1,
relaycon_receive, params );
XP_MEMSET( &storage->saddr, 0, sizeof(storage->saddr) );
storage->saddr.sin_family = PF_INET;
storage->saddr.sin_addr.s_addr = htonl( hostNameToIP(host) );
storage->saddr.sin_port = htons(port);
}
void
relaycon_reg( LaunchParams* params, const XP_UCHAR* devID, DevIDType typ )
{
LOG_FUNC();
XP_U8 tmpbuf[32];
int indx = 0;
RelayConStorage* storage = getStorage( params );
XP_ASSERT( !!devID || typ == ID_TYPE_ANON );
indx += writeHeader( storage, tmpbuf, XWPDEV_REG );
tmpbuf[indx++] = typ;
indx += writeDevID( &tmpbuf[indx], sizeof(tmpbuf) - indx, devID );
sendIt( storage, tmpbuf, indx );
}
XP_S16
relaycon_send( LaunchParams* params, const XP_U8* buf, XP_U16 buflen,
XP_U32 gameToken, const CommsAddrRec* XP_UNUSED(addrRec) )
{
XP_ASSERT( 0 != gameToken );
ssize_t nSent = -1;
RelayConStorage* storage = getStorage( params );
XP_U8 tmpbuf[1 + 4 + 1 + sizeof(gameToken) + buflen];
int indx = 0;
indx += writeHeader( storage, tmpbuf, XWPDEV_MSG );
XP_U32 inNBO = htonl(gameToken);
XP_MEMCPY( &tmpbuf[indx], &inNBO, sizeof(inNBO) );
indx += sizeof(inNBO);
XP_MEMCPY( &tmpbuf[indx], buf, buflen );
indx += buflen;
nSent = sendIt( storage, tmpbuf, indx );
if ( nSent > buflen ) {
nSent = buflen;
}
LOG_RETURNF( "%d", nSent );
return nSent;
}
XP_S16
relaycon_sendnoconn( LaunchParams* params, const XP_U8* buf, XP_U16 buflen,
const XP_UCHAR* relayID, XP_U32 gameToken )
{
XP_LOGF( "%s(relayID=%s)", __func__, relayID );
XP_ASSERT( 0 != gameToken );
XP_U16 indx = 0;
ssize_t nSent = -1;
RelayConStorage* storage = getStorage( params );
XP_U16 idLen = XP_STRLEN( relayID );
XP_U8 tmpbuf[1 + 4 + 1 +
1 + idLen +
sizeof(gameToken) + buflen];
indx += writeHeader( storage, tmpbuf, XWPDEV_MSGNOCONN );
gameToken = htonl( gameToken );
XP_MEMCPY( &tmpbuf[indx], &gameToken, sizeof(gameToken) );
indx += sizeof(gameToken);
XP_MEMCPY( &tmpbuf[indx], relayID, idLen );
indx += idLen;
tmpbuf[indx++] = '\n';
XP_MEMCPY( &tmpbuf[indx], buf, buflen );
nSent = sendIt( storage, tmpbuf, sizeof(tmpbuf) );
if ( nSent > buflen ) {
nSent = buflen;
}
LOG_RETURNF( "%d", nSent );
return nSent;
}
void
relaycon_requestMsgs( LaunchParams* params, const XP_UCHAR* devID )
{
XP_LOGF( "%s(devID=%s)", __func__, devID );
RelayConStorage* storage = getStorage( params );
XP_U8 tmpbuf[128];
int indx = 0;
indx += writeHeader( storage, tmpbuf, XWPDEV_RQSTMSGS );
indx += addStrWithLength( &tmpbuf[indx], tmpbuf + sizeof(tmpbuf), devID );
sendIt( storage, tmpbuf, indx );
}
void
relaycon_deleted( LaunchParams* params, const XP_UCHAR* devID,
XP_U32 gameToken )
{
LOG_FUNC();
RelayConStorage* storage = getStorage( params );
XP_U8 tmpbuf[128];
int indx = 0;
indx += writeHeader( storage, tmpbuf, XWPDEV_DELGAME );
indx += writeDevID( &tmpbuf[indx], sizeof(tmpbuf) - indx, devID );
gameToken = htonl( gameToken );
memcpy( &tmpbuf[indx], &gameToken, sizeof(gameToken) );
indx += sizeof( gameToken );
sendIt( storage, tmpbuf, indx );
}
static void
sendAckIf( RelayConStorage* storage, const MsgHeader* header )
{
if ( header->cmd != XWPDEV_ACK ) {
XP_U8 tmpbuf[16];
int indx = writeHeader( storage, tmpbuf, XWPDEV_ACK );
uint32_t msgID = htonl( header->packetID );
memcpy( &tmpbuf[indx], &msgID, sizeof(msgID) );
indx += sizeof(msgID);
sendIt( storage, tmpbuf, indx );
}
}
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 );
gchar* b64 = g_base64_encode( (const guchar*)buf,
((0 <= nRead)? nRead : 0) );
XP_LOGF( "%s: read %d bytes ('%s')", __func__, nRead, b64 );
g_free( b64 );
if ( 0 <= nRead ) {
const XP_U8* ptr = buf;
const XP_U8* end = buf + nRead;
MsgHeader header;
if ( readHeader( &ptr, &header ) ) {
sendAckIf( storage, &header );
switch( header.cmd ) {
case XWPDEV_REGRSP: {
XP_U16 len = getNetShort( &ptr );
XP_UCHAR devID[len+1];
getNetString( &ptr, len, devID );
XP_U16 maxInterval = getNetShort( &ptr );
XP_LOGF( "%s: maxInterval=%d", __func__, maxInterval );
(*storage->procs.devIDChanged)( storage->procsClosure, devID );
}
break;
case XWPDEV_MSG:
(*storage->procs.msgReceived)( storage->procsClosure,
ptr, end - ptr );
break;
case XWPDEV_BADREG:
(*storage->procs.devIDChanged)( storage->procsClosure, NULL );
break;
case XWPDEV_HAVEMSGS: {
(*storage->procs.msgNoticeReceived)( storage->procsClosure );
break;
}
case XWPDEV_ALERT: {
XP_U16 len = getNetShort( &ptr );
XP_UCHAR buf[len+1];
getNetString( &ptr, len, buf );
(*storage->procs.msgErrorMsg)( storage->procsClosure, buf );
break;
}
case XWPDEV_ACK: {
XP_U32 packetID = getNetLong( &ptr );
XP_USE( packetID );
XP_LOGF( "got ack for packetID %ld", packetID );
break;
}
default:
XP_LOGF( "%s: Unexpected cmd %d", __func__, header.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 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;
}
static ssize_t
sendIt( RelayConStorage* storage, const XP_U8* msgbuf, XP_U16 len )
{
ssize_t nSent = sendto( storage->socket, msgbuf, len, 0, /* flags */
(struct sockaddr*)&storage->saddr,
sizeof(storage->saddr) );
XP_LOGF( "%s()=>%d", __func__, nSent );
return nSent;
}
static size_t
addStrWithLength( XP_U8* buf, XP_U8* end, const XP_UCHAR* str )
{
XP_U16 len = !!str? XP_STRLEN( str ) : 0;
if ( buf + len + sizeof(len) <= end ) {
XP_U16 lenNBO = htons( len );
XP_MEMCPY( buf, &lenNBO, sizeof(lenNBO) );
buf += sizeof(lenNBO);
XP_MEMCPY( buf, str, len );
}
return len + sizeof(len);
}
static size_t
writeDevID( XP_U8* buf, size_t len, const XP_UCHAR* str )
{
return addStrWithLength( buf, buf + len, str );
}
static XP_U16
getNetShort( const XP_U8** ptr )
{
XP_U16 result;
memcpy( &result, *ptr, sizeof(result) );
*ptr += sizeof(result);
return ntohs( result );
}
static XP_U32
getNetLong( const XP_U8** ptr )
{
XP_U32 result;
memcpy( &result, *ptr, sizeof(result) );
*ptr += sizeof(result);
return ntohl( result );
}
static void
getNetString( const XP_U8** ptr, XP_U16 len, XP_UCHAR* buf )
{
memcpy( buf, *ptr, len );
*ptr += len;
buf[len] = '\0';
}
static int
writeHeader( RelayConStorage* storage, XP_U8* dest, XWRelayReg cmd )
{
int indx = 0;
dest[indx++] = XWPDEV_PROTO_VERSION;
uint32_t packetNum = storage->nextID++;
packetNum = htonl(packetNum);
memcpy( &dest[indx], &packetNum, sizeof(packetNum) );
indx += sizeof(packetNum);
dest[indx++] = cmd;
return indx;
}
static bool
readHeader( const XP_U8** buf, MsgHeader* header )
{
const XP_U8* ptr = *buf;
bool ok = XWPDEV_PROTO_VERSION == *ptr++;
assert( ok );
uint32_t packetID;
memcpy( &packetID, ptr, sizeof(packetID) );
ptr += sizeof(packetID);
header->packetID = ntohl( packetID );
XP_LOGF( "%s: got packet %d", __func__, header->packetID );
header->cmd = *ptr++;
*buf = ptr;
return ok;
}
/* Utilities */
#define TOKEN_MULT 1000000
XP_U32
makeClientToken( sqlite3_int64 rowid, XP_U16 seed )
{
XP_ASSERT( rowid < 0x0000FFFF );
XP_U32 result = rowid;
result *= TOKEN_MULT; /* so visible when displayed as base-10 */
result += seed;
return result;
}
void
rowidFromToken( XP_U32 clientToken, sqlite3_int64* rowid, XP_U16* seed )
{
*rowid = clientToken / TOKEN_MULT;
*seed = clientToken % TOKEN_MULT;
}