/*
* Copyright (C) 2011-2012 Christian Beier <dontmind@freeshell.org>
* 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.
*/
/*
* sockets.c - functions to deal with sockets.
*/
#ifdef __STRICT_ANSI__
#define _BSD_SOURCE
#ifdef __linux__
/* Setting this on other systems hides definitions such as INADDR_LOOPBACK.
* The check should be for __GLIBC__ in fact. */
# define _POSIX_SOURCE
#endif
#endif
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <assert.h>
#include <rfb/rfbclient.h>
#ifdef WIN32
#undef SOCKET
#include <winsock2.h>
#define EWOULDBLOCK WSAEWOULDBLOCK
#define close closesocket
#define read(sock,buf,len) recv(sock,buf,len,0)
#define write(sock,buf,len) send(sock,buf,len,0)
#define socklen_t int
#ifdef LIBVNCSERVER_HAVE_WS2TCPIP_H
#undef socklen_t
#include <ws2tcpip.h>
#endif
#else
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/un.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#endif
#include "tls.h"
#ifdef _MSC_VER
# define snprintf _snprintf
#endif
void PrintInHex(char *buf, int len);
rfbBool errorMessageOnReadFailure = TRUE;
/*
* ReadFromRFBServer is called whenever we want to read some data from the RFB
* server. It is non-trivial for two reasons:
*
* 1. For efficiency it performs some intelligent buffering, avoiding invoking
* the read() system call too often. For small chunks of data, it simply
* copies the data out of an internal buffer. For large amounts of data it
* reads directly into the buffer provided by the caller.
*
* 2. Whenever read() would block, it invokes the Xt event dispatching
* mechanism to process X events. In fact, this is the only place these
* events are processed, as there is no XtAppMainLoop in the program.
*/
rfbBool
ReadFromRFBServer(rfbClient* client, char *out, unsigned int n)
{
#undef DEBUG_READ_EXACT
#ifdef DEBUG_READ_EXACT
char* oout=out;
int nn=n;
rfbClientLog("ReadFromRFBServer %d bytes\n",n);
#endif
/* Handle attempts to write to NULL out buffer that might occur
when an outside malloc() fails. For instance, memcpy() to NULL
results in undefined behaviour and probably memory corruption.*/
if(!out)
return FALSE;
if (client->serverPort==-1) {
/* vncrec playing */
rfbVNCRec* rec = client->vncRec;
struct timeval tv;
if (rec->readTimestamp) {
rec->readTimestamp = FALSE;
if (!fread(&tv,sizeof(struct timeval),1,rec->file))
return FALSE;
tv.tv_sec = rfbClientSwap32IfLE (tv.tv_sec);
tv.tv_usec = rfbClientSwap32IfLE (tv.tv_usec);
if (rec->tv.tv_sec!=0 && !rec->doNotSleep) {
struct timeval diff;
diff.tv_sec = tv.tv_sec - rec->tv.tv_sec;
diff.tv_usec = tv.tv_usec - rec->tv.tv_usec;
if(diff.tv_usec<0) {
diff.tv_sec--;
diff.tv_usec+=1000000;
}
#ifndef WIN32
sleep (diff.tv_sec);
usleep (diff.tv_usec);
#else
Sleep (diff.tv_sec * 1000 + diff.tv_usec/1000);
#endif
}
rec->tv=tv;
}
return (fread(out,1,n,rec->file) != n ? FALSE : TRUE);
}
if (n <= client->buffered) {
memcpy(out, client->bufoutptr, n);
client->bufoutptr += n;
client->buffered -= n;
#ifdef DEBUG_READ_EXACT
goto hexdump;
#endif
return TRUE;
}
memcpy(out, client->bufoutptr, client->buffered);
out += client->buffered;
n -= client->buffered;
client->bufoutptr = client->buf;
client->buffered = 0;
if (n <= RFB_BUF_SIZE) {
while (client->buffered < n) {
int i;
if (client->tlsSession) {
i = ReadFromTLS(client, client->buf + client->buffered, RFB_BUF_SIZE - client->buffered);
} else {
i = read(client->sock, client->buf + client->buffered, RFB_BUF_SIZE - client->buffered);
}
if (i <= 0) {
if (i < 0) {
#ifdef WIN32
errno=WSAGetLastError();
#endif
if (errno == EWOULDBLOCK || errno == EAGAIN) {
/* TODO:
ProcessXtEvents();
*/
WaitForMessage(client, 100000);
i = 0;
} else {
rfbClientErr("read (%d: %s)\n",errno,strerror(errno));
return FALSE;
}
} else {
if (errorMessageOnReadFailure) {
rfbClientLog("VNC server closed connection\n");
}
return FALSE;
}
}
client->buffered += i;
}
memcpy(out, client->bufoutptr, n);
client->bufoutptr += n;
client->buffered -= n;
} else {
while (n > 0) {
int i;
if (client->tlsSession) {
i = ReadFromTLS(client, out, n);
} else {
i = read(client->sock, out, n);
}
if (i <= 0) {
if (i < 0) {
#ifdef WIN32
errno=WSAGetLastError();
#endif
if (errno == EWOULDBLOCK || errno == EAGAIN) {
/* TODO:
ProcessXtEvents();
*/
WaitForMessage(client, 100000);
i = 0;
} else {
rfbClientErr("read (%s)\n",strerror(errno));
return FALSE;
}
} else {
if (errorMessageOnReadFailure) {
rfbClientLog("VNC server closed connection\n");
}
return FALSE;
}
}
out += i;
n -= i;
}
}
#ifdef DEBUG_READ_EXACT
hexdump:
{ int ii;
for(ii=0;ii<nn;ii++)
fprintf(stderr,"%02x ",(unsigned char)oout[ii]);
fprintf(stderr,"\n");
}
#endif
return TRUE;
}
/*
* Write an exact number of bytes, and don't return until you've sent them.
*/
rfbBool
WriteToRFBServer(rfbClient* client, char *buf, int n)
{
fd_set fds;
int i = 0;
int j;
if (client->serverPort==-1)
return TRUE; /* vncrec playing */
if (client->tlsSession) {
/* WriteToTLS() will guarantee either everything is written, or error/eof returns */
i = WriteToTLS(client, buf, n);
if (i <= 0) return FALSE;
return TRUE;
}
while (i < n) {
j = write(client->sock, buf + i, (n - i));
if (j <= 0) {
if (j < 0) {
#ifdef WIN32
errno=WSAGetLastError();
#endif
if (errno == EWOULDBLOCK ||
#ifdef LIBVNCSERVER_ENOENT_WORKAROUND
errno == ENOENT ||
#endif
errno == EAGAIN) {
FD_ZERO(&fds);
FD_SET(client->sock,&fds);
if (select(client->sock+1, NULL, &fds, NULL, NULL) <= 0) {
rfbClientErr("select\n");
return FALSE;
}
j = 0;
} else {
rfbClientErr("write\n");
return FALSE;
}
} else {
rfbClientLog("write failed\n");
return FALSE;
}
}
i += j;
}
return TRUE;
}
static int initSockets() {
#ifdef WIN32
WSADATA trash;
static rfbBool WSAinitted=FALSE;
if(!WSAinitted) {
int i=WSAStartup(MAKEWORD(2,0),&trash);
if(i!=0) {
rfbClientErr("Couldn't init Windows Sockets\n");
return 0;
}
WSAinitted=TRUE;
}
#endif
return 1;
}
/*
* ConnectToTcpAddr connects to the given TCP port.
*/
int
ConnectClientToTcpAddr(unsigned int host, int port)
{
int sock;
struct sockaddr_in addr;
int one = 1;
if (!initSockets())
return -1;
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = host;
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock < 0) {
#ifdef WIN32
errno=WSAGetLastError();
#endif
rfbClientErr("ConnectToTcpAddr: socket (%s)\n",strerror(errno));
return -1;
}
if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
rfbClientErr("ConnectToTcpAddr: connect\n");
close(sock);
return -1;
}
if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
(char *)&one, sizeof(one)) < 0) {
rfbClientErr("ConnectToTcpAddr: setsockopt\n");
close(sock);
return -1;
}
return sock;
}
int
ConnectClientToTcpAddr6(const char *hostname, int port)
{
#ifdef LIBVNCSERVER_IPv6
int sock;
int n;
struct addrinfo hints, *res, *ressave;
char port_s[10];
int one = 1;
if (!initSockets())
return -1;
snprintf(port_s, 10, "%d", port);
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
if ((n = getaddrinfo(hostname, port_s, &hints, &res)))
{
rfbClientErr("ConnectClientToTcpAddr6: getaddrinfo (%s)\n", gai_strerror(n));
return -1;
}
ressave = res;
sock = -1;
while (res)
{
sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
if (sock >= 0)
{
if (connect(sock, res->ai_addr, res->ai_addrlen) == 0)
break;
close(sock);
sock = -1;
}
res = res->ai_next;
}
freeaddrinfo(ressave);
if (sock == -1)
{
rfbClientErr("ConnectClientToTcpAddr6: connect\n");
return -1;
}
if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
(char *)&one, sizeof(one)) < 0) {
rfbClientErr("ConnectToTcpAddr: setsockopt\n");
close(sock);
return -1;
}
return sock;
#else
rfbClientErr("ConnectClientToTcpAddr6: IPv6 disabled\n");
return -1;
#endif
}
int
ConnectClientToUnixSock(const char *sockFile)
{
#ifdef WIN32
rfbClientErr("Windows doesn't support UNIX sockets\n");
return -1;
#else
int sock;
struct sockaddr_un addr;
addr.sun_family = AF_UNIX;
if(strlen(sockFile) + 1 > sizeof(addr.sun_path)) {
rfbClientErr("ConnectToUnixSock: socket file name too long\n");
return -1;
}
strcpy(addr.sun_path, sockFile);
sock = socket(AF_UNIX, SOCK_STREAM, 0);
if (sock < 0) {
rfbClientErr("ConnectToUnixSock: socket (%s)\n",strerror(errno));
return -1;
}
if (connect(sock, (struct sockaddr *)&addr, sizeof(addr.sun_family) + strlen(addr.sun_path)) < 0) {
rfbClientErr("ConnectToUnixSock: connect\n");
close(sock);
return -1;
}
return sock;
#endif
}
/*
* FindFreeTcpPort tries to find unused TCP port in the range
* (TUNNEL_PORT_OFFSET, TUNNEL_PORT_OFFSET + 99]. Returns 0 on failure.
*/
int
FindFreeTcpPort(void)
{
int sock, port;
struct sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_ANY);
if (!initSockets())
return -1;
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock < 0) {
rfbClientErr(": FindFreeTcpPort: socket\n");
return 0;
}
for (port = TUNNEL_PORT_OFFSET + 99; port > TUNNEL_PORT_OFFSET; port--) {
addr.sin_port = htons((unsigned short)port);
if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0) {
close(sock);
return port;
}
}
close(sock);
return 0;
}
/*
* ListenAtTcpPort starts listening at the given TCP port.
*/
int
ListenAtTcpPort(int port)
{
return ListenAtTcpPortAndAddress(port, NULL);
}
/*
* ListenAtTcpPortAndAddress starts listening at the given TCP port on
* the given IP address
*/
int
ListenAtTcpPortAndAddress(int port, const char *address)
{
int sock;
int one = 1;
#ifndef LIBVNCSERVER_IPv6
struct sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
if (address) {
addr.sin_addr.s_addr = inet_addr(address);
} else {
addr.sin_addr.s_addr = htonl(INADDR_ANY);
}
if (!initSockets())
return -1;
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock < 0) {
rfbClientErr("ListenAtTcpPort: socket\n");
return -1;
}
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
(const char *)&one, sizeof(one)) < 0) {
rfbClientErr("ListenAtTcpPort: setsockopt\n");
close(sock);
return -1;
}
if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
rfbClientErr("ListenAtTcpPort: bind\n");
close(sock);
return -1;
}
#else
int rv;
struct addrinfo hints, *servinfo, *p;
char port_str[8];
snprintf(port_str, 8, "%d", port);
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_PASSIVE; /* fill in wildcard address if address == NULL */
if (!initSockets())
return -1;
if ((rv = getaddrinfo(address, port_str, &hints, &servinfo)) != 0) {
rfbClientErr("ListenAtTcpPortAndAddress: error in getaddrinfo: %s\n", gai_strerror(rv));
return -1;
}
/* loop through all the results and bind to the first we can */
for(p = servinfo; p != NULL; p = p->ai_next) {
if ((sock = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) < 0) {
continue;
}
#ifdef IPV6_V6ONLY
/* we have separate IPv4 and IPv6 sockets since some OS's do not support dual binding */
if (p->ai_family == AF_INET6 && setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&one, sizeof(one)) < 0) {
rfbClientErr("ListenAtTcpPortAndAddress: error in setsockopt IPV6_V6ONLY: %s\n", strerror(errno));
close(sock);
freeaddrinfo(servinfo);
return -1;
}
#endif
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&one, sizeof(one)) < 0) {
rfbClientErr("ListenAtTcpPortAndAddress: error in setsockopt SO_REUSEADDR: %s\n", strerror(errno));
close(sock);
freeaddrinfo(servinfo);
return -1;
}
if (bind(sock, p->ai_addr, p->ai_addrlen) < 0) {
close(sock);
continue;
}
break;
}
if (p == NULL) {
rfbClientErr("ListenAtTcpPortAndAddress: error in bind: %s\n", strerror(errno));
return -1;
}
/* all done with this structure now */
freeaddrinfo(servinfo);
#endif
if (listen(sock, 5) < 0) {
rfbClientErr("ListenAtTcpPort: listen\n");
close(sock);
return -1;
}
return sock;
}
/*
* AcceptTcpConnection accepts a TCP connection.
*/
int
AcceptTcpConnection(int listenSock)
{
int sock;
struct sockaddr_in addr;
socklen_t addrlen = sizeof(addr);
int one = 1;
sock = accept(listenSock, (struct sockaddr *) &addr, &addrlen);
if (sock < 0) {
rfbClientErr("AcceptTcpConnection: accept\n");
return -1;
}
if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
(char *)&one, sizeof(one)) < 0) {
rfbClientErr("AcceptTcpConnection: setsockopt\n");
close(sock);
return -1;
}
return sock;
}
/*
* SetNonBlocking sets a socket into non-blocking mode.
*/
rfbBool
SetNonBlocking(int sock)
{
#ifdef WIN32
unsigned long block=1;
if(ioctlsocket(sock, FIONBIO, &block) == SOCKET_ERROR) {
errno=WSAGetLastError();
#else
int flags = fcntl(sock, F_GETFL);
if(flags < 0 || fcntl(sock, F_SETFL, flags | O_NONBLOCK) < 0) {
#endif
rfbClientErr("Setting socket to non-blocking failed: %s\n",strerror(errno));
return FALSE;
}
return TRUE;
}
/*
* SetDSCP sets a socket's IP QoS parameters aka Differentiated Services Code Point field
*/
rfbBool
SetDSCP(int sock, int dscp)
{
#ifdef WIN32
rfbClientErr("Setting of QoS IP DSCP not implemented for Windows\n");
return TRUE;
#else
int level, cmd;
struct sockaddr addr;
socklen_t addrlen = sizeof(addr);
if(getsockname(sock, &addr, &addrlen) != 0) {
rfbClientErr("Setting socket QoS failed while getting socket address: %s\n",strerror(errno));
return FALSE;
}
switch(addr.sa_family)
{
#if defined LIBVNCSERVER_IPv6 && defined IPV6_TCLASS
case AF_INET6:
level = IPPROTO_IPV6;
cmd = IPV6_TCLASS;
break;
#endif
case AF_INET:
level = IPPROTO_IP;
cmd = IP_TOS;
break;
default:
rfbClientErr("Setting socket QoS failed: Not bound to IP address");
return FALSE;
}
if(setsockopt(sock, level, cmd, (void*)&dscp, sizeof(dscp)) != 0) {
rfbClientErr("Setting socket QoS failed: %s\n", strerror(errno));
return FALSE;
}
return TRUE;
#endif
}
/*
* StringToIPAddr - convert a host string to an IP address.
*/
rfbBool
StringToIPAddr(const char *str, unsigned int *addr)
{
struct hostent *hp;
if (strcmp(str,"") == 0) {
*addr = htonl(INADDR_LOOPBACK); /* local */
return TRUE;
}
*addr = inet_addr(str);
if (*addr != -1)
return TRUE;
if (!initSockets())
return -1;
hp = gethostbyname(str);
if (hp) {
*addr = *(unsigned int *)hp->h_addr;
return TRUE;
}
return FALSE;
}
/*
* Test if the other end of a socket is on the same machine.
*/
rfbBool
SameMachine(int sock)
{
struct sockaddr_in peeraddr, myaddr;
socklen_t addrlen = sizeof(struct sockaddr_in);
getpeername(sock, (struct sockaddr *)&peeraddr, &addrlen);
getsockname(sock, (struct sockaddr *)&myaddr, &addrlen);
return (peeraddr.sin_addr.s_addr == myaddr.sin_addr.s_addr);
}
/*
* Print out the contents of a packet for debugging.
*/
void
PrintInHex(char *buf, int len)
{
int i, j;
char c, str[17];
str[16] = 0;
rfbClientLog("ReadExact: ");
for (i = 0; i < len; i++)
{
if ((i % 16 == 0) && (i != 0)) {
rfbClientLog(" ");
}
c = buf[i];
str[i % 16] = (((c > 31) && (c < 127)) ? c : '.');
rfbClientLog("%02x ",(unsigned char)c);
if ((i % 4) == 3)
rfbClientLog(" ");
if ((i % 16) == 15)
{
rfbClientLog("%s\n",str);
}
}
if ((i % 16) != 0)
{
for (j = i % 16; j < 16; j++)
{
rfbClientLog(" ");
if ((j % 4) == 3) rfbClientLog(" ");
}
str[i % 16] = 0;
rfbClientLog("%s\n",str);
}
fflush(stderr);
}
int WaitForMessage(rfbClient* client,unsigned int usecs)
{
fd_set fds;
struct timeval timeout;
int num;
if (client->serverPort==-1)
/* playing back vncrec file */
return 1;
timeout.tv_sec=(usecs/1000000);
timeout.tv_usec=(usecs%1000000);
FD_ZERO(&fds);
FD_SET(client->sock,&fds);
num=select(client->sock+1, &fds, NULL, NULL, &timeout);
if(num<0) {
#ifdef WIN32
errno=WSAGetLastError();
#endif
rfbClientLog("Waiting for message failed: %d (%s)\n",errno,strerror(errno));
}
return num;
}