KasmVNC/common/rfb/HTTPServer.cxx
2020-09-20 12:16:44 +00:00

425 lines
11 KiB
C++

/* Copyright (C) 2002-2005 RealVNC Ltd. 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/HTTPServer.h>
#include <rfb/LogWriter.h>
#include <rfb/util.h>
#include <rdr/MemOutStream.h>
using namespace rfb;
using namespace rdr;
static LogWriter vlog("HTTPServer");
const int clientWaitTimeMillis = 20000;
const int idleTimeoutSecs = 5 * 60;
//
// -=- LineReader
// Helper class which is repeatedly called until a line has been read
// (lines end in \n or \r\n).
// Returns true when line complete, and resets internal state so that
// next read() call will start reading a new line.
// Only one buffer is kept - process line before reading next line!
//
class LineReader : public CharArray {
public:
LineReader(InStream& is_, int l)
: CharArray(l), is(is_), pos(0), len(l), bufferOverrun(false) {}
// Returns true if line complete, false otherwise
bool read() {
while (is.checkNoWait(1)) {
char c = is.readU8();
if (c == '\n') {
if (pos && (buf[pos-1] == '\r'))
pos--;
bufferOverrun = false;
buf[pos++] = 0;
pos = 0;
return true;
}
if (pos == (len-1)) {
bufferOverrun = true;
buf[pos] = 0;
return true;
}
buf[pos++] = c;
}
return false;
}
bool didBufferOverrun() const {return bufferOverrun;}
protected:
InStream& is;
int pos, len;
bool bufferOverrun;
};
//
// -=- HTTPServer::Session
// Manages the internal state for an HTTP session.
// processHTTP returns true when request has completed,
// indicating that socket & session data can be deleted.
//
class rfb::HTTPServer::Session {
public:
Session(network::Socket& s, rfb::HTTPServer& srv)
: contentType(0), contentLength(-1), lastModified(-1),
line(s.inStream(), 256), sock(s),
server(srv), state(ReadRequestLine), lastActive(time(0)) {
}
~Session() {
}
void writeResponse(int result, const char* text);
bool writeResponse(int code);
bool processHTTP();
network::Socket* getSock() const {return &sock;}
int checkIdleTimeout();
protected:
CharArray uri;
const char* contentType;
int contentLength;
time_t lastModified;
LineReader line;
network::Socket& sock;
rfb::HTTPServer& server;
enum {ReadRequestLine, ReadHeaders, WriteResponse} state;
enum {GetRequest, HeadRequest} request;
time_t lastActive;
};
// - Internal helper routines
void
copyStream(InStream& is, OutStream& os) {
try {
while (1) {
os.writeU8(is.readU8());
}
} catch (rdr::EndOfStream&) {
}
}
void writeLine(OutStream& os, const char* text) {
os.writeBytes(text, strlen(text));
os.writeBytes("\r\n", 2);
}
// - Write an HTTP-compliant response to the client
void
HTTPServer::Session::writeResponse(int result, const char* text) {
char buffer[1024];
if (strlen(text) > 512)
throw new rdr::Exception("Internal error - HTTP response text too big");
sprintf(buffer, "%s %d %s", "HTTP/1.1", result, text);
OutStream& os=sock.outStream();
writeLine(os, buffer);
writeLine(os, "Server: KasmVNC/4.0");
time_t now = time(0);
struct tm* tm = gmtime(&now);
strftime(buffer, 1024, "Date: %a, %d %b %Y %H:%M:%S GMT", tm);
writeLine(os, buffer);
if (lastModified == (time_t)-1 || lastModified == 0)
lastModified = now;
tm = gmtime(&lastModified);
strftime(buffer, 1024, "Last-Modified: %a, %d %b %Y %H:%M:%S GMT", tm);
writeLine(os, buffer);
if (contentLength != -1) {
sprintf(buffer,"Content-Length: %d",contentLength);
writeLine(os, buffer);
}
writeLine(os, "Connection: close");
os.writeBytes("Content-Type: ", 14);
if (result == 200) {
if (!contentType)
contentType = guessContentType(uri.buf, "text/html");
os.writeBytes(contentType, strlen(contentType));
} else {
os.writeBytes("text/html", 9);
}
os.writeBytes("\r\n", 2);
writeLine(os, "");
if (result != 200) {
writeLine(os, "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">");
writeLine(os, "<HTML><HEAD>");
sprintf(buffer, "<TITLE>%d %s</TITLE>", result, text);
writeLine(os, buffer);
writeLine(os, "</HEAD><BODY><H1>");
writeLine(os, text);
writeLine(os, "</H1></BODY></HTML>");
sock.outStream().flush();
}
}
bool
HTTPServer::Session::writeResponse(int code) {
switch (code) {
case 200: writeResponse(code, "OK"); break;
case 400: writeResponse(code, "Bad Request"); break;
case 404: writeResponse(code, "Not Found"); break;
case 501: writeResponse(code, "Not Implemented"); break;
default: writeResponse(500, "Unknown Error"); break;
};
// This return code is passed straight out of processHTTP().
// true indicates that the request has been completely processed.
return true;
}
// - Main HTTP request processing routine
bool
HTTPServer::Session::processHTTP() {
lastActive = time(0);
while (sock.inStream().checkNoWait(1)) {
switch (state) {
// Reading the Request-Line
case ReadRequestLine:
// Either read a line, or run out of incoming data
if (!line.read())
return false;
// We have read a line! Skip it if it's blank
if (strlen(line.buf) == 0)
continue;
// The line contains a request to process.
{
char method[16], path[128], version[16];
int matched = sscanf(line.buf, "%15s%127s%15s",
method, path, version);
if (matched != 3)
return writeResponse(400);
// Store the required "method"
if (strcmp(method, "GET") == 0)
request = GetRequest;
else if (strcmp(method, "HEAD") == 0)
request = HeadRequest;
else
return writeResponse(501);
// Store the URI to the "document"
uri.buf = strDup(path);
}
// Move on to reading the request headers
state = ReadHeaders;
break;
// Reading the request headers
case ReadHeaders:
// Try to read a line
if (!line.read())
return false;
// Skip headers until we hit a blank line
if (strlen(line.buf) != 0)
continue;
// Headers ended - write the response!
{
CharArray address(sock.getPeerAddress());
vlog.info("getting %s for %s", uri.buf, address.buf);
contentLength = -1;
lastModified = -1;
InStream* data = server.getFile(uri.buf, &contentType, &contentLength,
&lastModified);
if (!data)
return writeResponse(404);
try {
writeResponse(200);
if (request == GetRequest)
copyStream(*data, sock.outStream());
sock.outStream().flush();
} catch (rdr::Exception& e) {
vlog.error("error writing HTTP document:%s", e.str());
}
delete data;
}
// The operation is complete!
return true;
default:
throw rdr::Exception("invalid HTTPSession state!");
};
}
// Indicate that we're still processing the HTTP request.
return false;
}
int HTTPServer::Session::checkIdleTimeout() {
time_t now = time(0);
int timeout = (lastActive + idleTimeoutSecs) - now;
if (timeout > 0)
return secsToMillis(timeout);
sock.shutdown();
return 0;
}
// -=- Constructor / destructor
HTTPServer::HTTPServer() {
}
HTTPServer::~HTTPServer() {
std::list<Session*>::iterator i;
for (i=sessions.begin(); i!=sessions.end(); i++)
delete *i;
}
// -=- SocketServer interface implementation
void
HTTPServer::addSocket(network::Socket* sock, bool) {
Session* s = new Session(*sock, *this);
if (!s) {
sock->shutdown();
} else {
sock->inStream().setTimeout(clientWaitTimeMillis);
sock->outStream().setTimeout(clientWaitTimeMillis);
sessions.push_front(s);
}
}
void
HTTPServer::removeSocket(network::Socket* sock) {
std::list<Session*>::iterator i;
for (i=sessions.begin(); i!=sessions.end(); i++) {
if ((*i)->getSock() == sock) {
delete *i;
sessions.erase(i);
return;
}
}
}
void
HTTPServer::processSocketReadEvent(network::Socket* sock) {
std::list<Session*>::iterator i;
for (i=sessions.begin(); i!=sessions.end(); i++) {
if ((*i)->getSock() == sock) {
try {
if ((*i)->processHTTP()) {
vlog.info("completed HTTP request");
sock->shutdown();
}
} catch (rdr::Exception& e) {
vlog.error("untrapped: %s", e.str());
sock->shutdown();
}
return;
}
}
throw rdr::Exception("invalid Socket in HTTPServer");
}
void
HTTPServer::processSocketWriteEvent(network::Socket* sock) {
std::list<Session*>::iterator i;
for (i=sessions.begin(); i!=sessions.end(); i++) {
if ((*i)->getSock() == sock) {
try {
sock->outStream().flush();
} catch (rdr::Exception& e) {
vlog.error("untrapped: %s", e.str());
sock->shutdown();
}
return;
}
}
throw rdr::Exception("invalid Socket in HTTPServer");
}
void HTTPServer::getSockets(std::list<network::Socket*>* sockets)
{
sockets->clear();
std::list<Session*>::iterator ci;
for (ci = sessions.begin(); ci != sessions.end(); ci++) {
sockets->push_back((*ci)->getSock());
}
}
int HTTPServer::checkTimeouts() {
std::list<Session*>::iterator ci;
int timeout = 0;
for (ci = sessions.begin(); ci != sessions.end(); ci++) {
soonestTimeout(&timeout, (*ci)->checkIdleTimeout());
}
return timeout;
}
// -=- Default getFile implementation
InStream*
HTTPServer::getFile(const char* name, const char** contentType,
int* contentLength, time_t* lastModified)
{
return 0;
}
const char*
HTTPServer::guessContentType(const char* name, const char* defType) {
CharArray file, ext;
if (!strSplit(name, '.', &file.buf, &ext.buf))
return defType;
if (strcasecmp(ext.buf, "html") == 0 ||
strcasecmp(ext.buf, "htm") == 0) {
return "text/html";
} else if (strcasecmp(ext.buf, "txt") == 0) {
return "text/plain";
} else if (strcasecmp(ext.buf, "gif") == 0) {
return "image/gif";
} else if (strcasecmp(ext.buf, "jpg") == 0) {
return "image/jpeg";
} else if (strcasecmp(ext.buf, "jar") == 0) {
return "application/java-archive";
} else if (strcasecmp(ext.buf, "exe") == 0) {
return "application/octet-stream";
}
return defType;
}