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/*
* httpd.c - a simple HTTP server
*/
/*
* Copyright (C) 2002 RealVNC Ltd.
* 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>
#include <ctype.h>
#ifdef LIBVNCSERVER_HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef LIBVNCSERVER_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef LIBVNCSERVER_HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <errno.h>
#ifdef WIN32
#include <winsock.h>
#define close closesocket
#else
#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
#include <pwd.h>
#endif
#ifdef USE_LIBWRAP
#include <tcpd.h>
#endif
#define NOT_FOUND_STR "HTTP/1.0 404 Not found\r\n\r\n" \
"<HEAD><TITLE>File Not Found</TITLE></HEAD>\n" \
"<BODY><H1>File Not Found</H1></BODY>\n"
#define INVALID_REQUEST_STR "HTTP/1.0 400 Invalid Request\r\n\r\n" \
"<HEAD><TITLE>Invalid Request</TITLE></HEAD>\n" \
"<BODY><H1>Invalid request</H1></BODY>\n"
#define OK_STR "HTTP/1.0 200 OK\nContent-Type: text/html\r\n\r\n"
static void httpProcessInput();
static rfbBool compareAndSkip(char **ptr, const char *str);
static rfbBool parseParams(const char *request, char *result, int max_bytes);
static rfbBool validateString(char *str);
#define BUF_SIZE 32768
static char buf[BUF_SIZE];
static size_t buf_filled=0;
/*
* httpInitSockets sets up the TCP socket to listen for HTTP connections.
*/
void
httpInitSockets(rfbScreenInfoPtr rfbScreen)
{
if (rfbScreen->httpInitDone)
return;
rfbScreen->httpInitDone = TRUE;
if (!rfbScreen->httpDir)
return;
if (rfbScreen->httpPort == 0) {
rfbScreen->httpPort = rfbScreen->rfbPort-100;
}
rfbLog("Listening for HTTP connections on TCP port %d\n", rfbScreen->httpPort);
rfbLog(" URL http://%s:%d\n",rfbScreen->rfbThisHost,rfbScreen->httpPort);
if ((rfbScreen->httpListenSock = ListenOnTCPPort(rfbScreen->httpPort)) < 0) {
rfbLogPerror("ListenOnTCPPort");
return;
}
/*AddEnabledDevice(httpListenSock);*/
}
/*
* httpCheckFds is called from ProcessInputEvents to check for input on the
* HTTP socket(s). If there is input to process, httpProcessInput is called.
*/
void
httpCheckFds(rfbScreenInfoPtr rfbScreen)
{
int nfds;
fd_set fds;
struct timeval tv;
struct sockaddr_in addr;
size_t addrlen = sizeof(addr);
if (!rfbScreen->httpDir)
return;
FD_ZERO(&fds);
FD_SET(rfbScreen->httpListenSock, &fds);
if (rfbScreen->httpSock >= 0) {
FD_SET(rfbScreen->httpSock, &fds);
}
tv.tv_sec = 0;
tv.tv_usec = 0;
nfds = select(max(rfbScreen->httpSock,rfbScreen->httpListenSock) + 1, &fds, NULL, NULL, &tv);
if (nfds == 0) {
return;
}
if (nfds < 0) {
#ifdef WIN32
errno = WSAGetLastError();
#endif
if (errno != EINTR)
rfbLogPerror("httpCheckFds: select");
return;
}
if ((rfbScreen->httpSock >= 0) && FD_ISSET(rfbScreen->httpSock, &fds)) {
httpProcessInput(rfbScreen);
}
if (FD_ISSET(rfbScreen->httpListenSock, &fds)) {
int flags;
if (rfbScreen->httpSock >= 0) close(rfbScreen->httpSock);
if ((rfbScreen->httpSock = accept(rfbScreen->httpListenSock,
(struct sockaddr *)&addr, &addrlen)) < 0) {
rfbLogPerror("httpCheckFds: accept");
return;
}
#ifdef USE_LIBWRAP
if(!hosts_ctl("vnc",STRING_UNKNOWN,inet_ntoa(addr.sin_addr),
STRING_UNKNOWN)) {
rfbLog("Rejected HTTP connection from client %s\n",
inet_ntoa(addr.sin_addr));
#else
flags = fcntl(rfbScreen->httpSock, F_GETFL);
if (flags < 0 || fcntl(rfbScreen->httpSock, F_SETFL, flags | O_NONBLOCK) == -1) {
rfbLogPerror("httpCheckFds: fcntl");
#endif
close(rfbScreen->httpSock);
rfbScreen->httpSock = -1;
return;
}
flags=fcntl(rfbScreen->httpSock,F_GETFL);
if(flags==-1 ||
fcntl(rfbScreen->httpSock,F_SETFL,flags|O_NONBLOCK)==-1) {
rfbLogPerror("httpCheckFds: fcntl");
close(rfbScreen->httpSock);
rfbScreen->httpSock=-1;
return;
}
/*AddEnabledDevice(httpSock);*/
}
}
static void
httpCloseSock(rfbScreenInfoPtr rfbScreen)
{
close(rfbScreen->httpSock);
rfbScreen->httpSock = -1;
buf_filled = 0;
}
static rfbClientRec cl;
/*
* httpProcessInput is called when input is received on the HTTP socket.
*/
static void
httpProcessInput(rfbScreenInfoPtr rfbScreen)
{
struct sockaddr_in addr;
size_t addrlen = sizeof(addr);
char fullFname[512];
char params[1024];
char *ptr;
char *fname;
unsigned int maxFnameLen;
FILE* fd;
rfbBool performSubstitutions = FALSE;
char str[256+32];
#ifndef WIN32
char* user=getenv("USER");
#endif
cl.sock=rfbScreen->httpSock;
if (strlen(rfbScreen->httpDir) > 255) {
rfbErr("-httpd directory too long\n");
httpCloseSock(rfbScreen);
return;
}
strcpy(fullFname, rfbScreen->httpDir);
fname = &fullFname[strlen(fullFname)];
maxFnameLen = 511 - strlen(fullFname);
buf_filled=0;
/* Read data from the HTTP client until we get a complete request. */
while (1) {
ssize_t got;
if (buf_filled > sizeof (buf)) {
rfbErr("httpProcessInput: HTTP request is too long\n");
httpCloseSock(rfbScreen);
return;
}
got = read (rfbScreen->httpSock, buf + buf_filled,
sizeof (buf) - buf_filled - 1);
if (got <= 0) {
if (got == 0) {
rfbErr("httpd: premature connection close\n");
} else {
if (errno == EAGAIN) {
return;
}
rfbLogPerror("httpProcessInput: read");
}
httpCloseSock(rfbScreen);
return;
}
buf_filled += got;
buf[buf_filled] = '\0';
/* Is it complete yet (is there a blank line)? */
if (strstr (buf, "\r\r") || strstr (buf, "\n\n") ||
strstr (buf, "\r\n\r\n") || strstr (buf, "\n\r\n\r"))
break;
}
/* Process the request. */
if(rfbScreen->httpEnableProxyConnect) {
const static char* PROXY_OK_STR = "HTTP/1.0 200 OK\r\nContent-Type: octet-stream\r\nPragma: no-cache\r\n\r\n";
if(!strncmp(buf, "CONNECT ", 8)) {
if(atoi(strchr(buf, ':')+1)!=rfbScreen->rfbPort) {
rfbErr("httpd: CONNECT format invalid.\n");
WriteExact(&cl,INVALID_REQUEST_STR, strlen(INVALID_REQUEST_STR));
httpCloseSock(rfbScreen);
return;
}
/* proxy connection */
rfbLog("httpd: client asked for CONNECT\n");
WriteExact(&cl,PROXY_OK_STR,strlen(PROXY_OK_STR));
rfbNewClientConnection(rfbScreen,rfbScreen->httpSock);
rfbScreen->httpSock = -1;
return;
}
if (!strncmp(buf, "GET ",4) && !strncmp(strchr(buf,'/'),"/proxied.connection HTTP/1.", 27)) {
/* proxy connection */
rfbLog("httpd: client asked for /proxied.connection\n");
WriteExact(&cl,PROXY_OK_STR,strlen(PROXY_OK_STR));
rfbNewClientConnection(rfbScreen,rfbScreen->httpSock);
rfbScreen->httpSock = -1;
return;
}
}
if (strncmp(buf, "GET ", 4)) {
rfbErr("httpd: no GET line\n");
httpCloseSock(rfbScreen);
return;
} else {
/* Only use the first line. */
buf[strcspn(buf, "\n\r")] = '\0';
}
if (strlen(buf) > maxFnameLen) {
rfbErr("httpd: GET line too long\n");
httpCloseSock(rfbScreen);
return;
}
if (sscanf(buf, "GET %s HTTP/1.0", fname) != 1) {
rfbErr("httpd: couldn't parse GET line\n");
httpCloseSock(rfbScreen);
return;
}
if (fname[0] != '/') {
rfbErr("httpd: filename didn't begin with '/'\n");
WriteExact(&cl, NOT_FOUND_STR, strlen(NOT_FOUND_STR));
httpCloseSock(rfbScreen);
return;
}
if (strchr(fname+1, '/') != NULL) {
rfbErr("httpd: asking for file in other directory\n");
WriteExact(&cl, NOT_FOUND_STR, strlen(NOT_FOUND_STR));
httpCloseSock(rfbScreen);
return;
}
getpeername(rfbScreen->httpSock, (struct sockaddr *)&addr, &addrlen);
rfbLog("httpd: get '%s' for %s\n", fname+1,
inet_ntoa(addr.sin_addr));
/* Extract parameters from the URL string if necessary */
params[0] = '\0';
ptr = strchr(fname, '?');
if (ptr != NULL) {
*ptr = '\0';
if (!parseParams(&ptr[1], params, 1024)) {
params[0] = '\0';
rfbErr("httpd: bad parameters in the URL\n");
}
}
/* If we were asked for '/', actually read the file index.vnc */
if (strcmp(fname, "/") == 0) {
strcpy(fname, "/index.vnc");
rfbLog("httpd: defaulting to '%s'\n", fname+1);
}
/* Substitutions are performed on files ending .vnc */
if (strlen(fname) >= 4 && strcmp(&fname[strlen(fname)-4], ".vnc") == 0) {
performSubstitutions = TRUE;
}
/* Open the file */
if ((fd = fopen(fullFname, "r")) == 0) {
rfbLogPerror("httpProcessInput: open");
WriteExact(&cl, NOT_FOUND_STR, strlen(NOT_FOUND_STR));
httpCloseSock(rfbScreen);
return;
}
WriteExact(&cl, OK_STR, strlen(OK_STR));
while (1) {
int n = fread(buf, 1, BUF_SIZE-1, fd);
if (n < 0) {
rfbLogPerror("httpProcessInput: read");
fclose(fd);
httpCloseSock(rfbScreen);
return;
}
if (n == 0)
break;
if (performSubstitutions) {
/* Substitute $WIDTH, $HEIGHT, etc with the appropriate values.
This won't quite work properly if the .vnc file is longer than
BUF_SIZE, but it's reasonable to assume that .vnc files will
always be short. */
char *ptr = buf;
char *dollar;
buf[n] = 0; /* make sure it's null-terminated */
while ((dollar = strchr(ptr, '$'))!=NULL) {
WriteExact(&cl, ptr, (dollar - ptr));
ptr = dollar;
if (compareAndSkip(&ptr, "$WIDTH")) {
sprintf(str, "%d", rfbScreen->width);
WriteExact(&cl, str, strlen(str));
} else if (compareAndSkip(&ptr, "$HEIGHT")) {
sprintf(str, "%d", rfbScreen->height);
WriteExact(&cl, str, strlen(str));
} else if (compareAndSkip(&ptr, "$APPLETWIDTH")) {
sprintf(str, "%d", rfbScreen->width);
WriteExact(&cl, str, strlen(str));
} else if (compareAndSkip(&ptr, "$APPLETHEIGHT")) {
sprintf(str, "%d", rfbScreen->height + 32);
WriteExact(&cl, str, strlen(str));
} else if (compareAndSkip(&ptr, "$PORT")) {
sprintf(str, "%d", rfbScreen->rfbPort);
WriteExact(&cl, str, strlen(str));
} else if (compareAndSkip(&ptr, "$DESKTOP")) {
WriteExact(&cl, rfbScreen->desktopName, strlen(rfbScreen->desktopName));
} else if (compareAndSkip(&ptr, "$DISPLAY")) {
sprintf(str, "%s:%d", rfbScreen->rfbThisHost, rfbScreen->rfbPort-5900);
WriteExact(&cl, str, strlen(str));
} else if (compareAndSkip(&ptr, "$USER")) {
#ifndef WIN32
if (user) {
WriteExact(&cl, user,
strlen(user));
} else
#endif
WriteExact(&cl, "?", 1);
} else if (compareAndSkip(&ptr, "$PARAMS")) {
if (params[0] != '\0')
WriteExact(&cl, params, strlen(params));
} else {
if (!compareAndSkip(&ptr, "$$"))
ptr++;
if (WriteExact(&cl, "$", 1) < 0) {
fclose(fd);
httpCloseSock(rfbScreen);
return;
}
}
}
if (WriteExact(&cl, ptr, (&buf[n] - ptr)) < 0)
break;
} else {
/* For files not ending .vnc, just write out the buffer */
if (WriteExact(&cl, buf, n) < 0)
break;
}
}
fclose(fd);
httpCloseSock(rfbScreen);
}
static rfbBool
compareAndSkip(char **ptr, const char *str)
{
if (strncmp(*ptr, str, strlen(str)) == 0) {
*ptr += strlen(str);
return TRUE;
}
return FALSE;
}
/*
* Parse the request tail after the '?' character, and format a sequence
* of <param> tags for inclusion into an HTML page with embedded applet.
*/
static rfbBool
parseParams(const char *request, char *result, int max_bytes)
{
char param_request[128];
char param_formatted[196];
const char *tail;
char *delim_ptr;
char *value_str;
int cur_bytes, len;
result[0] = '\0';
cur_bytes = 0;
tail = request;
for (;;) {
/* Copy individual "name=value" string into a buffer */
delim_ptr = strchr((char *)tail, '&');
if (delim_ptr == NULL) {
if (strlen(tail) >= sizeof(param_request)) {
return FALSE;
}
strcpy(param_request, tail);
} else {
len = delim_ptr - tail;
if (len >= sizeof(param_request)) {
return FALSE;
}
memcpy(param_request, tail, len);
param_request[len] = '\0';
}
/* Split the request into parameter name and value */
value_str = strchr(¶m_request[1], '=');
if (value_str == NULL) {
return FALSE;
}
*value_str++ = '\0';
if (strlen(value_str) == 0) {
return FALSE;
}
/* Validate both parameter name and value */
if (!validateString(param_request) || !validateString(value_str)) {
return FALSE;
}
/* Prepare HTML-formatted representation of the name=value pair */
len = sprintf(param_formatted,
"<PARAM NAME=\"%s\" VALUE=\"%s\">\n",
param_request, value_str);
if (cur_bytes + len + 1 > max_bytes) {
return FALSE;
}
strcat(result, param_formatted);
cur_bytes += len;
/* Go to the next parameter */
if (delim_ptr == NULL) {
break;
}
tail = delim_ptr + 1;
}
return TRUE;
}
/*
* Check if the string consists only of alphanumeric characters, '+'
* signs, underscores, and dots. Replace all '+' signs with spaces.
*/
static rfbBool
validateString(char *str)
{
char *ptr;
for (ptr = str; *ptr != '\0'; ptr++) {
if (!isalnum(*ptr) && *ptr != '_' && *ptr != '.') {
if (*ptr == '+') {
*ptr = ' ';
} else {
return FALSE;
}
}
}
return TRUE;
}
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