/*
* sockets.c - deal with TCP & UDP sockets.
*
* This code should be independent of any changes in the RFB protocol. It just
* deals with the X server scheduling stuff, calling rfbNewClientConnection and
* rfbProcessClientMessage to actually deal with the protocol. If a socket
* needs to be closed for any reason then rfbCloseClient should be called, and
* this in turn will call rfbClientConnectionGone. To make an active
* connection out, call rfbConnect - note that this does _not_ call
* rfbNewClientConnection.
*
* This file is divided into two types of function. Those beginning with
* "rfb" are specific to sockets using the RFB protocol. Those without the
* "rfb" prefix are more general socket routines (which are used by the http
* code).
*
* Thanks to Karl Hakimian for pointing out that some platforms return EAGAIN
* not EWOULDBLOCK.
*/
/*
* Copyright (C) 2005 Rohit Kumar, Johannes E. Schindelin
* OSXvnc Copyright (C) 2001 Dan McGuirk <mcguirk@incompleteness.net>.
* Original Xvnc code Copyright (C) 1999 AT&T Laboratories Cambridge.
* All Rights Reserved.
*
* This 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 software 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 software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
#include <rfb/rfb.h>
#ifdef LIBVNCSERVER_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef LIBVNCSERVER_HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef LIBVNCSERVER_HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef LIBVNCSERVER_HAVE_NETINET_IN_H
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netdb.h>
#include <arpa/inet.h>
#endif
#ifdef LIBVNCSERVER_HAVE_UNISTD_H
#include <unistd.h>
#endif
#if defined(__linux__) && defined(NEED_TIMEVAL)
struct timeval
{
long int tv_sec,tv_usec;
}
;
#endif
#ifdef LIBVNCSERVER_HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <errno.h>
#ifdef USE_LIBWRAP
#include <syslog.h>
#include <tcpd.h>
int allow_severity=LOG_INFO;
int deny_severity=LOG_WARNING;
#endif
#if defined(WIN32)
#ifndef __MINGW32__
#pragma warning (disable: 4018 4761)
#endif
#define read(sock,buf,len) recv(sock,buf,len,0)
#define EWOULDBLOCK WSAEWOULDBLOCK
#define ETIMEDOUT WSAETIMEDOUT
#define write(sock,buf,len) send(sock,buf,len,0)
#else
#define closesocket close
#endif
int rfbMaxClientWait = 20000; /* time (ms) after which we decide client has
gone away - needed to stop us hanging */
/*
* rfbInitSockets sets up the TCP and UDP sockets to listen for RFB
* connections. It does nothing if called again.
*/
void
rfbInitSockets(rfbScreenInfoPtr rfbScreen)
{
in_addr_t iface = rfbScreen->listenInterface;
if (rfbScreen->socketState!=RFB_SOCKET_INIT)
return;
rfbScreen->socketState = RFB_SOCKET_READY;
if (rfbScreen->inetdSock != -1) {
const int one = 1;
#ifndef WIN32
if (fcntl(rfbScreen->inetdSock, F_SETFL, O_NONBLOCK) < 0) {
rfbLogPerror("fcntl");
return;
}
#endif
if (setsockopt(rfbScreen->inetdSock, IPPROTO_TCP, TCP_NODELAY,
(char *)&one, sizeof(one)) < 0) {
rfbLogPerror("setsockopt");
return;
}
FD_ZERO(&(rfbScreen->allFds));
FD_SET(rfbScreen->inetdSock, &(rfbScreen->allFds));
rfbScreen->maxFd = rfbScreen->inetdSock;
return;
}
if(rfbScreen->autoPort) {
int i;
rfbLog("Autoprobing TCP port \n");
for (i = 5900; i < 6000; i++) {
if ((rfbScreen->listenSock = rfbListenOnTCPPort(i, iface)) >= 0) {
rfbScreen->port = i;
break;
}
}
if (i >= 6000) {
rfbLogPerror("Failure autoprobing");
return;
}
rfbLog("Autoprobing selected port %d\n", rfbScreen->port);
FD_ZERO(&(rfbScreen->allFds));
FD_SET(rfbScreen->listenSock, &(rfbScreen->allFds));
rfbScreen->maxFd = rfbScreen->listenSock;
}
else if(rfbScreen->port>0) {
rfbLog("Listening for VNC connections on TCP port %d\n", rfbScreen->port);
if ((rfbScreen->listenSock = rfbListenOnTCPPort(rfbScreen->port, iface)) < 0) {
rfbLogPerror("ListenOnTCPPort");
return;
}
FD_ZERO(&(rfbScreen->allFds));
FD_SET(rfbScreen->listenSock, &(rfbScreen->allFds));
rfbScreen->maxFd = rfbScreen->listenSock;
}
if (rfbScreen->udpPort != 0) {
rfbLog("rfbInitSockets: listening for input on UDP port %d\n",rfbScreen->udpPort);
if ((rfbScreen->udpSock = rfbListenOnUDPPort(rfbScreen->udpPort, iface)) < 0) {
rfbLogPerror("ListenOnUDPPort");
return;
}
FD_SET(rfbScreen->udpSock, &(rfbScreen->allFds));
rfbScreen->maxFd = max((int)rfbScreen->udpSock,rfbScreen->maxFd);
}
}
void rfbShutdownSockets(rfbScreenInfoPtr rfbScreen)
{
if (rfbScreen->socketState!=RFB_SOCKET_READY)
return;
rfbScreen->socketState = RFB_SOCKET_SHUTDOWN;
if(rfbScreen->inetdSock>-1) {
closesocket(rfbScreen->inetdSock);
FD_CLR(rfbScreen->inetdSock,&rfbScreen->allFds);
rfbScreen->inetdSock=-1;
}
if(rfbScreen->listenSock>-1) {
closesocket(rfbScreen->listenSock);
FD_CLR(rfbScreen->listenSock,&rfbScreen->allFds);
rfbScreen->listenSock=-1;
}
if(rfbScreen->udpSock>-1) {
closesocket(rfbScreen->udpSock);
FD_CLR(rfbScreen->udpSock,&rfbScreen->allFds);
rfbScreen->udpSock=-1;
}
}
/*
* rfbCheckFds is called from ProcessInputEvents to check for input on the RFB
* socket(s). If there is input to process, the appropriate function in the
* RFB server code will be called (rfbNewClientConnection,
* rfbProcessClientMessage, etc).
*/
int
rfbCheckFds(rfbScreenInfoPtr rfbScreen,long usec)
{
int nfds;
fd_set fds;
struct timeval tv;
struct sockaddr_in addr;
socklen_t addrlen = sizeof(addr);
char buf[6];
const int one = 1;
int sock;
rfbClientIteratorPtr i;
rfbClientPtr cl;
int result = 0;
if (!rfbScreen->inetdInitDone && rfbScreen->inetdSock != -1) {
rfbNewClientConnection(rfbScreen,rfbScreen->inetdSock);
rfbScreen->inetdInitDone = TRUE;
}
do {
memcpy((char *)&fds, (char *)&(rfbScreen->allFds), sizeof(fd_set));
tv.tv_sec = 0;
tv.tv_usec = usec;
nfds = select(rfbScreen->maxFd + 1, &fds, NULL, NULL /* &fds */, &tv);
if (nfds == 0) {
/* timed out, check for async events */
i = rfbGetClientIterator(rfbScreen);
while((cl = rfbClientIteratorNext(i))) {
if (cl->onHold)
continue;
if (FD_ISSET(cl->sock, &(rfbScreen->allFds)))
rfbSendFileTransferChunk(cl);
}
rfbReleaseClientIterator(i);
return result;
}
if (nfds < 0) {
#ifdef WIN32
errno = WSAGetLastError();
#endif
if (errno != EINTR)
rfbLogPerror("rfbCheckFds: select");
return -1;
}
result += nfds;
if (rfbScreen->listenSock != -1 && FD_ISSET(rfbScreen->listenSock, &fds)) {
if ((sock = accept(rfbScreen->listenSock,
(struct sockaddr *)&addr, &addrlen)) < 0) {
rfbLogPerror("rfbCheckFds: accept");
return -1;
}
#ifndef WIN32
if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
rfbLogPerror("rfbCheckFds: fcntl");
closesocket(sock);
return -1;
}
#endif
if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
(char *)&one, sizeof(one)) < 0) {
rfbLogPerror("rfbCheckFds: setsockopt");
closesocket(sock);
return -1;
}
#ifdef USE_LIBWRAP
if(!hosts_ctl("vnc",STRING_UNKNOWN,inet_ntoa(addr.sin_addr),
STRING_UNKNOWN)) {
rfbLog("Rejected connection from client %s\n",
inet_ntoa(addr.sin_addr));
closesocket(sock);
return -1;
}
#endif
rfbLog("Got connection from client %s\n", inet_ntoa(addr.sin_addr));
rfbNewClient(rfbScreen,sock);
FD_CLR(rfbScreen->listenSock, &fds);
if (--nfds == 0)
return result;
}
if ((rfbScreen->udpSock != -1) && FD_ISSET(rfbScreen->udpSock, &fds)) {
if(!rfbScreen->udpClient)
rfbNewUDPClient(rfbScreen);
if (recvfrom(rfbScreen->udpSock, buf, 1, MSG_PEEK,
(struct sockaddr *)&addr, &addrlen) < 0) {
rfbLogPerror("rfbCheckFds: UDP: recvfrom");
rfbDisconnectUDPSock(rfbScreen);
rfbScreen->udpSockConnected = FALSE;
} else {
if (!rfbScreen->udpSockConnected ||
(memcmp(&addr, &rfbScreen->udpRemoteAddr, addrlen) != 0))
{
/* new remote end */
rfbLog("rfbCheckFds: UDP: got connection\n");
memcpy(&rfbScreen->udpRemoteAddr, &addr, addrlen);
rfbScreen->udpSockConnected = TRUE;
if (connect(rfbScreen->udpSock,
(struct sockaddr *)&addr, addrlen) < 0) {
rfbLogPerror("rfbCheckFds: UDP: connect");
rfbDisconnectUDPSock(rfbScreen);
return -1;
}
rfbNewUDPConnection(rfbScreen,rfbScreen->udpSock);
}
rfbProcessUDPInput(rfbScreen);
}
FD_CLR(rfbScreen->udpSock, &fds);
if (--nfds == 0)
return result;
}
i = rfbGetClientIterator(rfbScreen);
while((cl = rfbClientIteratorNext(i))) {
if (cl->onHold)
continue;
if (FD_ISSET(cl->sock, &(rfbScreen->allFds)))
{
if (FD_ISSET(cl->sock, &fds))
rfbProcessClientMessage(cl);
else
rfbSendFileTransferChunk(cl);
}
}
rfbReleaseClientIterator(i);
} while(rfbScreen->handleEventsEagerly);
return result;
}
void
rfbDisconnectUDPSock(rfbScreenInfoPtr rfbScreen)
{
rfbScreen->udpSockConnected = FALSE;
}
void
rfbCloseClient(rfbClientPtr cl)
{
rfbExtensionData* extension;
for(extension=cl->extensions; extension; extension=extension->next)
if(extension->extension->close)
extension->extension->close(cl, extension->data);
LOCK(cl->updateMutex);
#ifdef LIBVNCSERVER_HAVE_LIBPTHREAD
if (cl->sock != -1)
#endif
{
FD_CLR(cl->sock,&(cl->screen->allFds));
if(cl->sock==cl->screen->maxFd)
while(cl->screen->maxFd>0
&& !FD_ISSET(cl->screen->maxFd,&(cl->screen->allFds)))
cl->screen->maxFd--;
#ifndef __MINGW32__
shutdown(cl->sock,SHUT_RDWR);
#endif
closesocket(cl->sock);
cl->sock = -1;
}
TSIGNAL(cl->updateCond);
UNLOCK(cl->updateMutex);
}
/*
* rfbConnect is called to make a connection out to a given TCP address.
*/
int
rfbConnect(rfbScreenInfoPtr rfbScreen,
char *host,
int port)
{
int sock;
int one = 1;
rfbLog("Making connection to client on host %s port %d\n",
host,port);
if ((sock = rfbConnectToTcpAddr(host, port)) < 0) {
rfbLogPerror("connection failed");
return -1;
}
#ifndef WIN32
if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
rfbLogPerror("fcntl failed");
closesocket(sock);
return -1;
}
#endif
if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
(char *)&one, sizeof(one)) < 0) {
rfbLogPerror("setsockopt failed");
closesocket(sock);
return -1;
}
/* AddEnabledDevice(sock); */
FD_SET(sock, &rfbScreen->allFds);
rfbScreen->maxFd = max(sock,rfbScreen->maxFd);
return sock;
}
/*
* ReadExact reads an exact number of bytes from a client. Returns 1 if
* those bytes have been read, 0 if the other end has closed, or -1 if an error
* occurred (errno is set to ETIMEDOUT if it timed out).
*/
int
rfbReadExactTimeout(rfbClientPtr cl, char* buf, int len, int timeout)
{
int sock = cl->sock;
int n;
fd_set fds;
struct timeval tv;
while (len > 0) {
n = read(sock, buf, len);
if (n > 0) {
buf += n;
len -= n;
} else if (n == 0) {
return 0;
} else {
#ifdef WIN32
errno = WSAGetLastError();
#endif
if (errno == EINTR)
continue;
#ifdef LIBVNCSERVER_ENOENT_WORKAROUND
if (errno != ENOENT)
#endif
if (errno != EWOULDBLOCK && errno != EAGAIN) {
return n;
}
FD_ZERO(&fds);
FD_SET(sock, &fds);
tv.tv_sec = timeout / 1000;
tv.tv_usec = (timeout % 1000) * 1000;
n = select(sock+1, &fds, NULL, &fds, &tv);
if (n < 0) {
rfbLogPerror("ReadExact: select");
return n;
}
if (n == 0) {
errno = ETIMEDOUT;
return -1;
}
}
}
#undef DEBUG_READ_EXACT
#ifdef DEBUG_READ_EXACT
rfbLog("ReadExact %d bytes\n",len);
for(n=0;n<len;n++)
fprintf(stderr,"%02x ",(unsigned char)buf[n]);
fprintf(stderr,"\n");
#endif
return 1;
}
int rfbReadExact(rfbClientPtr cl,char* buf,int len)
{
return(rfbReadExactTimeout(cl,buf,len,rfbMaxClientWait));
}
/*
* WriteExact writes an exact number of bytes to a client. Returns 1 if
* those bytes have been written, or -1 if an error occurred (errno is set to
* ETIMEDOUT if it timed out).
*/
int
rfbWriteExact(rfbClientPtr cl,
const char *buf,
int len)
{
int sock = cl->sock;
int n;
fd_set fds;
struct timeval tv;
int totalTimeWaited = 0;
#undef DEBUG_WRITE_EXACT
#ifdef DEBUG_WRITE_EXACT
rfbLog("WriteExact %d bytes\n",len);
for(n=0;n<len;n++)
fprintf(stderr,"%02x ",(unsigned char)buf[n]);
fprintf(stderr,"\n");
#endif
LOCK(cl->outputMutex);
while (len > 0) {
n = write(sock, buf, len);
if (n > 0) {
buf += n;
len -= n;
} else if (n == 0) {
rfbErr("WriteExact: write returned 0?\n");
return 0;
} else {
#ifdef WIN32
errno = WSAGetLastError();
#endif
if (errno == EINTR)
continue;
if (errno != EWOULDBLOCK && errno != EAGAIN) {
UNLOCK(cl->outputMutex);
return n;
}
/* Retry every 5 seconds until we exceed rfbMaxClientWait. We
need to do this because select doesn't necessarily return
immediately when the other end has gone away */
FD_ZERO(&fds);
FD_SET(sock, &fds);
tv.tv_sec = 5;
tv.tv_usec = 0;
n = select(sock+1, NULL, &fds, NULL /* &fds */, &tv);
if (n < 0) {
if(errno==EINTR)
continue;
rfbLogPerror("WriteExact: select");
UNLOCK(cl->outputMutex);
return n;
}
if (n == 0) {
totalTimeWaited += 5000;
if (totalTimeWaited >= rfbMaxClientWait) {
errno = ETIMEDOUT;
UNLOCK(cl->outputMutex);
return -1;
}
} else {
totalTimeWaited = 0;
}
}
}
UNLOCK(cl->outputMutex);
return 1;
}
/* currently private, called by rfbProcessArguments() */
int
rfbStringToAddr(char *str, in_addr_t *addr) {
if (str == NULL || *str == '\0' || strcmp(str, "any") == 0) {
*addr = htonl(INADDR_ANY);
} else if (strcmp(str, "localhost") == 0) {
*addr = htonl(INADDR_LOOPBACK);
} else {
struct hostent *hp;
if ((*addr = inet_addr(str)) == htonl(INADDR_NONE)) {
if (!(hp = gethostbyname(str))) {
return 0;
}
*addr = *(unsigned long *)hp->h_addr;
}
}
return 1;
}
int
rfbListenOnTCPPort(int port,
in_addr_t iface)
{
struct sockaddr_in addr;
int sock;
int one = 1;
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = iface;
if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
return -1;
}
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
(char *)&one, sizeof(one)) < 0) {
closesocket(sock);
return -1;
}
if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
closesocket(sock);
return -1;
}
if (listen(sock, 5) < 0) {
closesocket(sock);
return -1;
}
return sock;
}
int
rfbConnectToTcpAddr(char *host,
int port)
{
struct hostent *hp;
int sock;
struct sockaddr_in addr;
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
if ((addr.sin_addr.s_addr = inet_addr(host)) == htonl(INADDR_NONE))
{
if (!(hp = gethostbyname(host))) {
errno = EINVAL;
return -1;
}
addr.sin_addr.s_addr = *(unsigned long *)hp->h_addr;
}
if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
return -1;
}
if (connect(sock, (struct sockaddr *)&addr, (sizeof(addr))) < 0) {
closesocket(sock);
return -1;
}
return sock;
}
int
rfbListenOnUDPPort(int port,
in_addr_t iface)
{
struct sockaddr_in addr;
int sock;
int one = 1;
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = iface;
if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
return -1;
}
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
(char *)&one, sizeof(one)) < 0) {
return -1;
}
if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
return -1;
}
return sock;
}
syntax highlighted by Code2HTML, v. 0.9.1