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libtdevnc/libvncclient/sockets.c

425 lines
8.2 KiB

/*
* 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.
*/
#include <unistd.h>
#include <sys/socket.h>
#include <errno.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <fcntl.h>
#include <assert.h>
#include <rfb/rfbclient.h>
void PrintInHex(char *buf, int len);
rfbBool errorMessageOnReadFailure = TRUE;
#define BUF_SIZE 8192
static char buf[BUF_SIZE];
static char *bufoutptr = buf;
static int buffered = 0;
/*
* 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)
{
if (n <= buffered) {
memcpy(out, bufoutptr, n);
bufoutptr += n;
buffered -= n;
return TRUE;
}
memcpy(out, bufoutptr, buffered);
out += buffered;
n -= buffered;
bufoutptr = buf;
buffered = 0;
if (n <= BUF_SIZE) {
while (buffered < n) {
int i = read(client->sock, buf + buffered, BUF_SIZE - buffered);
if (i <= 0) {
if (i < 0) {
if (errno == EWOULDBLOCK || errno == EAGAIN) {
/* TODO:
ProcessXtEvents();
*/
i = 0;
} else {
perror("read");
return FALSE;
}
} else {
if (errorMessageOnReadFailure) {
rfbClientLog("VNC server closed connection\n");
}
return FALSE;
}
}
buffered += i;
}
memcpy(out, bufoutptr, n);
bufoutptr += n;
buffered -= n;
return TRUE;
} else {
while (n > 0) {
int i = read(client->sock, out, n);
if (i <= 0) {
if (i < 0) {
if (errno == EWOULDBLOCK || errno == EAGAIN) {
/* TODO:
ProcessXtEvents();
*/
i = 0;
} else {
perror("read");
return FALSE;
}
} else {
if (errorMessageOnReadFailure) {
rfbClientLog("VNC server closed connection\n");
}
return FALSE;
}
}
out += i;
n -= i;
}
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;
while (i < n) {
j = write(client->sock, buf + i, (n - i));
if (j <= 0) {
if (j < 0) {
if (errno == EWOULDBLOCK || errno == EAGAIN) {
FD_ZERO(&fds);
FD_SET(client->sock,&fds);
if (select(client->sock+1, NULL, &fds, NULL, NULL) <= 0) {
perror("select");
return FALSE;
}
j = 0;
} else {
perror("write");
return FALSE;
}
} else {
rfbClientLog("write failed\n");
return FALSE;
}
}
i += j;
}
return TRUE;
}
/*
* ConnectToTcpAddr connects to the given TCP port.
*/
int
ConnectClientToTcpAddr(unsigned int host, int port)
{
int sock;
struct sockaddr_in addr;
int one = 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) {
perror("ConnectToTcpAddr: socket");
return -1;
}
if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
perror("ConnectToTcpAddr: connect");
close(sock);
return -1;
}
if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
(char *)&one, sizeof(one)) < 0) {
perror("ConnectToTcpAddr: setsockopt");
close(sock);
return -1;
}
return sock;
}
/*
* 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 = INADDR_ANY;
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock < 0) {
perror(": FindFreeTcpPort: socket");
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)
{
int sock;
struct sockaddr_in addr;
int one = 1;
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = INADDR_ANY;
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock < 0) {
perror("ListenAtTcpPort: socket");
return -1;
}
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
(const char *)&one, sizeof(one)) < 0) {
perror("ListenAtTcpPort: setsockopt");
close(sock);
return -1;
}
if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
perror("ListenAtTcpPort: bind");
close(sock);
return -1;
}
if (listen(sock, 5) < 0) {
perror("ListenAtTcpPort: listen");
close(sock);
return -1;
}
return sock;
}
/*
* AcceptTcpConnection accepts a TCP connection.
*/
int
AcceptTcpConnection(int listenSock)
{
int sock;
struct sockaddr_in addr;
int addrlen = sizeof(addr);
int one = 1;
sock = accept(listenSock, (struct sockaddr *) &addr, &addrlen);
if (sock < 0) {
perror("AcceptTcpConnection: accept");
return -1;
}
if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
(char *)&one, sizeof(one)) < 0) {
perror("AcceptTcpConnection: setsockopt");
close(sock);
return -1;
}
return sock;
}
/*
* SetNonBlocking sets a socket into non-blocking mode.
*/
rfbBool
SetNonBlocking(int sock)
{
if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
perror("AcceptTcpConnection: fcntl");
return FALSE;
}
return TRUE;
}
/*
* 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 = 0; /* local */
return TRUE;
}
*addr = inet_addr(str);
if (*addr != -1)
return TRUE;
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;
int 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);
}