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KasmVNC/common/rfb/VNCSConnectionST.cxx

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/* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
* Copyright 2009-2018 Pierre Ossman for Cendio AB
*
* 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 <network/TcpSocket.h>
#include <rfb/ComparingUpdateTracker.h>
#include <rfb/Encoder.h>
#include <rfb/KeyRemapper.h>
#include <rfb/LogWriter.h>
#include <rfb/Security.h>
#include <rfb/ServerCore.h>
#include <rfb/SMsgWriter.h>
#include <rfb/VNCServerST.h>
#include <rfb/VNCSConnectionST.h>
#include <rfb/screenTypes.h>
#include <rfb/fenceTypes.h>
#include <rfb/ledStates.h>
#define XK_LATIN1
#define XK_MISCELLANY
#define XK_XKB_KEYS
#include <rfb/keysymdef.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdint.h>
#include <wordexp.h>
#include "kasmpasswd.h"
using namespace rfb;
static LogWriter vlog("VNCSConnST");
static Cursor emptyCursor(0, 0, Point(0, 0), NULL);
extern rfb::BoolParameter disablebasicauth;
VNCSConnectionST::VNCSConnectionST(VNCServerST* server_, network::Socket *s,
bool reverse)
: sock(s), reverseConnection(reverse),
inProcessMessages(false),
pendingSyncFence(false), syncFence(false), fenceFlags(0),
fenceDataLen(0), fenceData(NULL), congestionTimer(this),
losslessTimer(this), kbdLogTimer(this), server(server_), updates(false),
updateRenderedCursor(false), removeRenderedCursor(false),
continuousUpdates(false), encodeManager(this, &server_->encCache),
needsPermCheck(false), pointerEventTime(0),
clientHasCursor(false),
accessRights(AccessDefault), startTime(time(0))
{
setStreams(&sock->inStream(), &sock->outStream());
peerEndpoint.buf = sock->getPeerEndpoint();
VNCServerST::connectionsLog.write(1,"accepted: %s", peerEndpoint.buf);
memset(bstats_total, 0, sizeof(bstats_total));
gettimeofday(&connStart, NULL);
// Check their permissions, if applicable
kasmpasswdpath[0] = '\0';
wordexp_t wexp;
if (!wordexp(rfb::Server::kasmPasswordFile, &wexp, WRDE_NOCMD))
strncpy(kasmpasswdpath, wexp.we_wordv[0], 4096);
kasmpasswdpath[4095] = '\0';
wordfree(&wexp);
user[0] = '\0';
const char *at = strchr(peerEndpoint.buf, '@');
if (at && at - peerEndpoint.buf > 1 && at - peerEndpoint.buf < 32) {
memcpy(user, peerEndpoint.buf, at - peerEndpoint.buf);
user[at - peerEndpoint.buf] = '\0';
}
bool write, owner;
if (!getPerms(write, owner) || !write) {
accessRights &= ~WRITER_PERMS;
}
// Configure the socket
setSocketTimeouts();
lastEventTime = time(0);
gettimeofday(&lastRealUpdate, NULL);
gettimeofday(&lastClipboardOp, NULL);
gettimeofday(&lastKeyEvent, NULL);
server->clients.push_front(this);
}
VNCSConnectionST::~VNCSConnectionST()
{
// If we reach here then VNCServerST is deleting us!
VNCServerST::connectionsLog.write(1,"closed: %s (%s)",
peerEndpoint.buf,
(closeReason.buf) ? closeReason.buf : "");
// Release any keys the client still had pressed
while (!pressedKeys.empty()) {
rdr::U32 keysym, keycode;
keysym = pressedKeys.begin()->second;
keycode = pressedKeys.begin()->first;
pressedKeys.erase(pressedKeys.begin());
vlog.debug("Releasing key 0x%x / 0x%x on client disconnect",
keysym, keycode);
server->desktop->keyEvent(keysym, keycode, false);
}
if (server->pointerClient == this)
server->pointerClient = 0;
// Remove this client from the server
server->clients.remove(this);
delete [] fenceData;
}
// Methods called from VNCServerST
bool VNCSConnectionST::init()
{
try {
initialiseProtocol();
} catch (rdr::Exception& e) {
close(e.str());
return false;
}
return true;
}
void VNCSConnectionST::close(const char* reason)
{
// Log the reason for the close
if (!closeReason.buf)
closeReason.buf = strDup(reason);
else
vlog.debug("second close: %s (%s)", peerEndpoint.buf, reason);
if (authenticated()) {
server->lastDisconnectTime = time(0);
}
try {
if (sock->outStream().bufferUsage() > 0) {
sock->cork(false);
sock->outStream().flush();
if (sock->outStream().bufferUsage() > 0)
vlog.error("Failed to flush remaining socket data on close");
}
} catch (rdr::Exception& e) {
vlog.error("Failed to flush remaining socket data on close: %s", e.str());
}
// Just shutdown the socket and mark our state as closing. Eventually the
// calling code will call VNCServerST's removeSocket() method causing us to
// be deleted.
sock->shutdown();
setState(RFBSTATE_CLOSING);
}
void VNCSConnectionST::processMessages()
{
if (state() == RFBSTATE_CLOSING) return;
try {
// - Now set appropriate socket timeouts and process data
setSocketTimeouts();
inProcessMessages = true;
// Get the underlying TCP layer to build large packets if we send
// multiple small responses.
sock->cork(true);
while (getInStream()->checkNoWait(1)) {
if (pendingSyncFence) {
syncFence = true;
pendingSyncFence = false;
}
processMsg();
if (syncFence) {
writer()->writeFence(fenceFlags, fenceDataLen, fenceData);
syncFence = false;
}
}
// Flush out everything in case we go idle after this.
sock->cork(false);
inProcessMessages = false;
// If there were anything requiring an update, try to send it here.
// We wait until now with this to aggregate responses and to give
// higher priority to user actions such as keyboard and pointer events.
writeFramebufferUpdate();
} catch (rdr::EndOfStream&) {
close("Clean disconnection");
} catch (rdr::Exception &e) {
close(e.str());
}
}
void VNCSConnectionST::flushSocket()
{
if (state() == RFBSTATE_CLOSING) return;
try {
setSocketTimeouts();
sock->outStream().flush();
// Flushing the socket might release an update that was previously
// delayed because of congestion.
if (sock->outStream().bufferUsage() == 0)
writeFramebufferUpdate();
} catch (rdr::Exception &e) {
close(e.str());
}
}
void VNCSConnectionST::pixelBufferChange()
{
try {
if (!authenticated()) return;
if (cp.width && cp.height && (server->pb->width() != cp.width ||
server->pb->height() != cp.height))
{
// We need to clip the next update to the new size, but also add any
// extra bits if it's bigger. If we wanted to do this exactly, something
// like the code below would do it, but at the moment we just update the
// entire new size. However, we do need to clip the damagedCursorRegion
// because that might be added to updates in writeFramebufferUpdate().
//updates.intersect(server->pb->getRect());
//
//if (server->pb->width() > cp.width)
// updates.add_changed(Rect(cp.width, 0, server->pb->width(),
// server->pb->height()));
//if (server->pb->height() > cp.height)
// updates.add_changed(Rect(0, cp.height, cp.width,
// server->pb->height()));
damagedCursorRegion.assign_intersect(server->pb->getRect());
cp.width = server->pb->width();
cp.height = server->pb->height();
cp.screenLayout = server->screenLayout;
if (state() == RFBSTATE_NORMAL) {
// We should only send EDS to client asking for both
if (!writer()->writeExtendedDesktopSize()) {
if (!writer()->writeSetDesktopSize()) {
close("Client does not support desktop resize");
return;
}
}
}
// Drop any lossy tracking that is now outside the framebuffer
encodeManager.pruneLosslessRefresh(Region(server->pb->getRect()));
}
// Just update the whole screen at the moment because we're too lazy to
// work out what's actually changed.
updates.clear();
updates.add_changed(server->pb->getRect());
writeFramebufferUpdate();
} catch(rdr::Exception &e) {
close(e.str());
}
}
void VNCSConnectionST::writeFramebufferUpdateOrClose()
{
try {
writeFramebufferUpdate();
} catch(rdr::Exception &e) {
close(e.str());
}
}
void VNCSConnectionST::screenLayoutChangeOrClose(rdr::U16 reason)
{
try {
screenLayoutChange(reason);
writeFramebufferUpdate();
} catch(rdr::Exception &e) {
close(e.str());
}
}
void VNCSConnectionST::bellOrClose()
{
try {
if (state() == RFBSTATE_NORMAL) writer()->writeBell();
} catch(rdr::Exception& e) {
close(e.str());
}
}
char *percentEncode(const char *str, const unsigned len) {
char *enc = (char *) calloc(len * 3 + 1, 1);
char *out = enc;
unsigned i;
for (i = 0; i < len; i++) {
if (isalnum(str[i]) || str[i] == ' ' || str[i] == '.' || str[i] == ',' ||
str[i] == '?' || str[i] == '!' || str[i] == '"' || str[i] == '\'') {
*out++ = str[i];
} else {
*out++ = '%';
sprintf(out, "%02X", str[i]);
out += 2;
}
}
return enc;
}
char *percentEncode4(const uint16_t *str, const unsigned len) {
char *enc = (char *) calloc(len * 5 + 1, 1);
char *out = enc;
unsigned i;
for (i = 0; i < len; i++) {
if ((str[i] < 128 && isalnum(str[i])) || str[i] == ' ' || str[i] == '.' ||
str[i] == ',' ||
str[i] == '?' || str[i] == '!' || str[i] == '"' || str[i] == '\'') {
*out++ = str[i];
} else {
*out++ = '%';
sprintf(out, "%04hX", str[i]);
out += 4;
}
}
return enc;
}
static void cliplog(const char *str, const int len, const int origlen,
const char *dir, const char *client) {
if (Server::DLP_ClipLog[0] == 'o')
return;
if (Server::DLP_ClipLog[0] == 'i') {
vlog.info("DLP: client %s: %s %u (%u requested) clipboard bytes", client, dir, len, origlen);
} else {
// URL-encode it
char *enc = percentEncode(str, len);
vlog.info("DLP: client %s: %s %u (%u requested) clipboard bytes: '%s'",
client, dir, len, origlen, enc);
free(enc);
}
}
#define KEYBUF_MAX 100
static uint16_t keybuf[KEYBUF_MAX];
static unsigned keybuf_cur;
static void flushKeylog(const char *client) {
if (Server::DLP_ClipLog[0] != 'v' || !keybuf_cur)
return;
char *enc = percentEncode4(keybuf, keybuf_cur);
vlog.info("DLP: client %s: keyboard bytes: '%s'",
client, enc);
free(enc);
keybuf_cur = 0;
}
static void keylog(unsigned keysym, const char *client) {
if (Server::DLP_ClipLog[0] != 'v')
return;
bool flush = false;
if (keysym == XK_Return)
flush = true;
// Map over-16bit keys to 0xffff - most eastern is under that
if (keysym > 0xffff)
keysym = 0xffff;
keybuf[keybuf_cur] = keysym;
keybuf_cur++;
if (keybuf_cur >= KEYBUF_MAX || keysym == '\n' || flush)
flushKeylog(client);
}
void VNCSConnectionST::requestClipboardOrClose()
{
try {
if (!(accessRights & AccessCutText)) return;
if (!rfb::Server::acceptCutText) return;
if (state() != RFBSTATE_NORMAL) return;
requestClipboard();
} catch(rdr::Exception& e) {
close(e.str());
}
}
void VNCSConnectionST::announceClipboardOrClose(bool available)
{
try {
if (!(accessRights & AccessCutText)) return;
if (!rfb::Server::sendCutText) return;
if (state() != RFBSTATE_NORMAL) return;
announceClipboard(available);
} catch(rdr::Exception& e) {
close(e.str());
}
}
void VNCSConnectionST::sendClipboardDataOrClose(const char* data)
{
try {
if (!(accessRights & AccessCutText)) return;
if (!rfb::Server::sendCutText) return;
if (msSince(&lastClipboardOp) < (unsigned) rfb::Server::DLP_ClipDelay) {
vlog.info("DLP: client %s: refused to send clipboard, too soon",
sock->getPeerAddress());
return;
}
int len = strlen(data);
const int origlen = len;
if (rfb::Server::DLP_ClipSendMax && len > rfb::Server::DLP_ClipSendMax)
len = rfb::Server::DLP_ClipSendMax;
cliplog(data, len, origlen, "sent", sock->getPeerAddress());
if (state() != RFBSTATE_NORMAL) return;
sendClipboardData(data, len);
gettimeofday(&lastClipboardOp, NULL);
} catch(rdr::Exception& e) {
close(e.str());
}
}
void VNCSConnectionST::setDesktopNameOrClose(const char *name)
{
try {
setDesktopName(name);
writeFramebufferUpdate();
} catch(rdr::Exception& e) {
close(e.str());
}
}
void VNCSConnectionST::setCursorOrClose()
{
try {
setCursor();
writeFramebufferUpdate();
} catch(rdr::Exception& e) {
close(e.str());
}
}
void VNCSConnectionST::setLEDStateOrClose(unsigned int state)
{
try {
setLEDState(state);
writeFramebufferUpdate();
} catch(rdr::Exception& e) {
close(e.str());
}
}
int VNCSConnectionST::checkIdleTimeout()
{
int idleTimeout = rfb::Server::idleTimeout;
if (idleTimeout == 0) return 0;
if (state() != RFBSTATE_NORMAL && idleTimeout < 15)
idleTimeout = 15; // minimum of 15 seconds while authenticating
time_t now = time(0);
if (now < lastEventTime) {
// Someone must have set the time backwards. Set lastEventTime so that the
// idleTimeout will count from now.
vlog.info("Time has gone backwards - resetting idle timeout");
lastEventTime = now;
}
int timeLeft = lastEventTime + idleTimeout - now;
if (timeLeft < -60) {
// Our callback is over a minute late - someone must have set the time
// forwards. Set lastEventTime so that the idleTimeout will count from
// now.
vlog.info("Time has gone forwards - resetting idle timeout");
lastEventTime = now;
return secsToMillis(idleTimeout);
}
if (timeLeft <= 0) {
close("Idle timeout");
return 0;
}
return secsToMillis(timeLeft);
}
bool VNCSConnectionST::getComparerState()
{
// We interpret a low compression level as an indication that the client
// wants to prioritise CPU usage over bandwidth, and hence disable the
// comparing update tracker.
return (cp.compressLevel == -1) || (cp.compressLevel > 1);
}
// renderedCursorChange() is called whenever the server-side rendered cursor
// changes shape or position. It ensures that the next update will clean up
// the old rendered cursor and if necessary draw the new rendered cursor.
void VNCSConnectionST::renderedCursorChange()
{
if (state() != RFBSTATE_NORMAL) return;
// Are we switching between client-side and server-side cursor?
if (clientHasCursor == needRenderedCursor())
setCursorOrClose();
bool hasRenderedCursor = !damagedCursorRegion.is_empty();
if (hasRenderedCursor)
removeRenderedCursor = true;
if (needRenderedCursor()) {
updateRenderedCursor = true;
writeFramebufferUpdateOrClose();
}
}
// cursorPositionChange() is called whenever the cursor has changed position by
// the server. If the client supports being informed about these changes then
// it will arrange for the new cursor position to be sent to the client.
void VNCSConnectionST::cursorPositionChange()
{
setCursorPos();
}
// needRenderedCursor() returns true if this client needs the server-side
// rendered cursor. This may be because it does not support local cursor or
// because the current cursor position has not been set by this client.
// Unfortunately we can't know for sure when the current cursor position has
// been set by this client. We guess that this is the case when the current
// cursor position is the same as the last pointer event from this client, or
// if it is a very short time since this client's last pointer event (up to a
// second). [ Ideally we should do finer-grained timing here and make the time
// configurable, but I don't think it's that important. ]
bool VNCSConnectionST::needRenderedCursor()
{
if (state() != RFBSTATE_NORMAL)
return false;
if (!cp.supportsLocalCursorWithAlpha &&
!cp.supportsLocalCursor && !cp.supportsLocalXCursor)
return true;
if (!server->cursorPos.equals(pointerEventPos) &&
(time(0) - pointerEventTime) > 0)
return true;
return false;
}
void VNCSConnectionST::approveConnectionOrClose(bool accept,
const char* reason)
{
try {
approveConnection(accept, reason);
} catch (rdr::Exception& e) {
close(e.str());
}
}
// -=- Callbacks from SConnection
void VNCSConnectionST::authSuccess()
{
lastEventTime = time(0);
server->startDesktop();
// - Set the connection parameters appropriately
cp.width = server->pb->width();
cp.height = server->pb->height();
cp.screenLayout = server->screenLayout;
cp.setName(server->getName());
cp.setLEDState(server->ledState);
// - Set the default pixel format
cp.setPF(server->pb->getPF());
char buffer[256];
cp.pf().print(buffer, 256);
vlog.info("Server default pixel format %s", buffer);
// - Mark the entire display as "dirty"
updates.add_changed(server->pb->getRect());
startTime = time(0);
}
void VNCSConnectionST::queryConnection(const char* userName)
{
// - Authentication succeeded - clear from blacklist
CharArray name; name.buf = sock->getPeerAddress();
server->blHosts->clearBlackmark(name.buf);
// - Special case to provide a more useful error message
if (rfb::Server::neverShared && !rfb::Server::disconnectClients &&
server->authClientCount() > 0) {
approveConnection(false, "The server is already in use");
return;
}
// - Does the client have the right to bypass the query?
if (reverseConnection ||
!(rfb::Server::queryConnect || sock->requiresQuery()) ||
(accessRights & AccessNoQuery))
{
approveConnection(true);
return;
}
// - Get the server to display an Accept/Reject dialog, if required
// If a dialog is displayed, the result will be PENDING, and the
// server will call approveConnection at a later time
CharArray reason;
VNCServerST::queryResult qr = server->queryConnection(sock, userName,
&reason.buf);
if (qr == VNCServerST::PENDING)
return;
// - If server returns ACCEPT/REJECT then pass result to SConnection
approveConnection(qr == VNCServerST::ACCEPT, reason.buf);
}
void VNCSConnectionST::clientInit(bool shared)
{
lastEventTime = time(0);
if (rfb::Server::alwaysShared || reverseConnection) shared = true;
if (!(accessRights & AccessNonShared)) shared = true;
if (rfb::Server::neverShared) shared = false;
if (!shared) {
if (rfb::Server::disconnectClients && (accessRights & AccessNonShared)) {
// - Close all the other connected clients
vlog.debug("non-shared connection - closing clients");
server->closeClients("Non-shared connection requested", getSock());
} else {
// - Refuse this connection if there are existing clients, in addition to
// this one
if (server->authClientCount() > 1) {
close("Server is already in use");
return;
}
}
}
SConnection::clientInit(shared);
}
void VNCSConnectionST::setPixelFormat(const PixelFormat& pf)
{
SConnection::setPixelFormat(pf);
char buffer[256];
pf.print(buffer, 256);
vlog.info("Client pixel format %s", buffer);
setCursor();
}
void VNCSConnectionST::pointerEvent(const Point& pos, int buttonMask, const bool skipClick, const bool skipRelease)
{
pointerEventTime = lastEventTime = time(0);
server->lastUserInputTime = lastEventTime;
if (!(accessRights & AccessPtrEvents)) return;
if (!rfb::Server::acceptPointerEvents) return;
if (!server->pointerClient || server->pointerClient == this) {
pointerEventPos = pos;
if (buttonMask)
server->pointerClient = this;
else
server->pointerClient = 0;
bool skipclick = false, skiprelease = false;
if (server->DLPRegion.enabled) {
rdr::U16 x1, y1, x2, y2;
server->translateDLPRegion(x1, y1, x2, y2);
if (pos.x < x1 || pos.x >= x2 ||
pos.y < y1 || pos.y >= y2) {
if (!Server::DLP_RegionAllowClick)
skipclick = true;
if (!Server::DLP_RegionAllowRelease)
skiprelease = true;
}
}
server->desktop->pointerEvent(pointerEventPos, buttonMask, skipclick, skiprelease);
}
}
class VNCSConnectionSTShiftPresser {
public:
VNCSConnectionSTShiftPresser(SDesktop* desktop_)
: desktop(desktop_), pressed(false) {}
~VNCSConnectionSTShiftPresser() {
if (pressed) {
vlog.debug("Releasing fake Shift_L");
desktop->keyEvent(XK_Shift_L, 0, false);
}
}
void press() {
vlog.debug("Pressing fake Shift_L");
desktop->keyEvent(XK_Shift_L, 0, true);
pressed = true;
}
SDesktop* desktop;
bool pressed;
};
// keyEvent() - record in the pressedKeys which keys were pressed. Allow
// multiple down events (for autorepeat), but only allow a single up event.
void VNCSConnectionST::keyEvent(rdr::U32 keysym, rdr::U32 keycode, bool down) {
rdr::U32 lookup;
lastEventTime = time(0);
server->lastUserInputTime = lastEventTime;
if (!(accessRights & AccessKeyEvents)) return;
if (!rfb::Server::acceptKeyEvents) return;
if (Server::DLP_KeyRateLimit > 0 && down &&
msSince(&lastKeyEvent) < (1000 / (unsigned) Server::DLP_KeyRateLimit)) {
vlog.info("DLP: client %s: refused keyboard event, too soon (%u ms vs %u)",
sock->getPeerAddress(), msSince(&lastKeyEvent),
(1000 / (unsigned) Server::DLP_KeyRateLimit));
return;
}
gettimeofday(&lastKeyEvent, NULL);
if (down) {
keylog(keysym, sock->getPeerAddress());
kbdLogTimer.start(60 * 1000);
vlog.debug("Key pressed: 0x%x / 0x%x", keysym, keycode);
} else {
vlog.debug("Key released: 0x%x / 0x%x", keysym, keycode);
}
// Remap the key if required
if (server->keyRemapper) {
rdr::U32 newkey;
newkey = server->keyRemapper->remapKey(keysym);
if (newkey != keysym) {
vlog.debug("Key remapped to 0x%x", newkey);
keysym = newkey;
}
}
// Avoid lock keys if we don't know the server state
if ((server->ledState == ledUnknown) &&
((keysym == XK_Caps_Lock) ||
(keysym == XK_Num_Lock) ||
(keysym == XK_Scroll_Lock))) {
vlog.debug("Ignoring lock key (e.g. caps lock)");
return;
}
// Lock key heuristics
// (only for clients that do not support the LED state extension)
if (!cp.supportsLEDState) {
// Always ignore ScrollLock as we don't have a heuristic
// for that
if (keysym == XK_Scroll_Lock) {
vlog.debug("Ignoring lock key (e.g. caps lock)");
return;
}
if (down && (server->ledState != ledUnknown)) {
// CapsLock synchronisation heuristic
// (this assumes standard interaction between CapsLock the Shift
// keys and normal characters)
if (((keysym >= XK_A) && (keysym <= XK_Z)) ||
((keysym >= XK_a) && (keysym <= XK_z))) {
bool uppercase, shift, lock;
uppercase = (keysym >= XK_A) && (keysym <= XK_Z);
shift = isShiftPressed();
lock = server->ledState & ledCapsLock;
if (lock == (uppercase == shift)) {
vlog.debug("Inserting fake CapsLock to get in sync with client");
server->desktop->keyEvent(XK_Caps_Lock, 0, true);
server->desktop->keyEvent(XK_Caps_Lock, 0, false);
}
}
// NumLock synchronisation heuristic
// (this is more cautious because of the differences between Unix,
// Windows and macOS)
if (((keysym >= XK_KP_Home) && (keysym <= XK_KP_Delete)) ||
((keysym >= XK_KP_0) && (keysym <= XK_KP_9)) ||
(keysym == XK_KP_Separator) || (keysym == XK_KP_Decimal)) {
bool number, shift, lock;
number = ((keysym >= XK_KP_0) && (keysym <= XK_KP_9)) ||
(keysym == XK_KP_Separator) || (keysym == XK_KP_Decimal);
shift = isShiftPressed();
lock = server->ledState & ledNumLock;
if (shift) {
// We don't know the appropriate NumLock state for when Shift
// is pressed as it could be one of:
//
// a) A Unix client where Shift negates NumLock
//
// b) A Windows client where Shift only cancels NumLock
//
// c) A macOS client where Shift doesn't have any effect
//
} else if (lock == (number == shift)) {
vlog.debug("Inserting fake NumLock to get in sync with client");
server->desktop->keyEvent(XK_Num_Lock, 0, true);
server->desktop->keyEvent(XK_Num_Lock, 0, false);
}
}
}
}
// Turn ISO_Left_Tab into shifted Tab.
VNCSConnectionSTShiftPresser shiftPresser(server->desktop);
if (keysym == XK_ISO_Left_Tab) {
if (!isShiftPressed())
shiftPresser.press();
keysym = XK_Tab;
}
// We need to be able to track keys, so generate a fake index when we
// aren't given a keycode
if (keycode == 0)
lookup = 0x80000000 | keysym;
else
lookup = keycode;
// We force the same keysym for an already down key for the
// sake of sanity
if (pressedKeys.find(lookup) != pressedKeys.end())
keysym = pressedKeys[lookup];
if (down) {
pressedKeys[lookup] = keysym;
} else {
if (!pressedKeys.erase(lookup))
return;
}
server->desktop->keyEvent(keysym, keycode, down);
}
void VNCSConnectionST::framebufferUpdateRequest(const Rect& r,bool incremental)
{
Rect safeRect;
if (!(accessRights & AccessView)) return;
SConnection::framebufferUpdateRequest(r, incremental);
// Check that the client isn't sending crappy requests
if (!r.enclosed_by(Rect(0, 0, cp.width, cp.height))) {
vlog.error("FramebufferUpdateRequest %dx%d at %d,%d exceeds framebuffer %dx%d",
r.width(), r.height(), r.tl.x, r.tl.y, cp.width, cp.height);
safeRect = r.intersect(Rect(0, 0, cp.width, cp.height));
} else {
safeRect = r;
}
// Just update the requested region.
// Framebuffer update will be sent a bit later, see processMessages().
Region reqRgn(safeRect);
if (!incremental || !continuousUpdates)
requested.assign_union(reqRgn);
if (!incremental) {
// Non-incremental update - treat as if area requested has changed
updates.add_changed(reqRgn);
// And send the screen layout to the client (which, unlike the
// framebuffer dimensions, the client doesn't get during init)
writer()->writeExtendedDesktopSize();
// We do not send a DesktopSize since it only contains the
// framebuffer size (which the client already should know) and
// because some clients don't handle extra DesktopSize events
// very well.
}
}
void VNCSConnectionST::setDesktopSize(int fb_width, int fb_height,
const ScreenSet& layout)
{
unsigned int result;
if (!(accessRights & AccessSetDesktopSize)) return;
if (!rfb::Server::acceptSetDesktopSize) return;
// Don't bother the desktop with an invalid configuration
if (!layout.validate(fb_width, fb_height)) {
writer()->writeExtendedDesktopSize(reasonClient, resultInvalid,
fb_width, fb_height, layout);
return;
}
// FIXME: the desktop will call back to VNCServerST and an extra set
// of ExtendedDesktopSize messages will be sent. This is okay
// protocol-wise, but unnecessary.
result = server->desktop->setScreenLayout(fb_width, fb_height, layout);
writer()->writeExtendedDesktopSize(reasonClient, result,
fb_width, fb_height, layout);
// Only notify other clients on success
if (result == resultSuccess) {
if (server->screenLayout != layout)
throw Exception("Desktop configured a different screen layout than requested");
server->notifyScreenLayoutChange(this);
}
}
void VNCSConnectionST::fence(rdr::U32 flags, unsigned len, const char data[])
{
rdr::U8 type;
if (flags & fenceFlagRequest) {
if (flags & fenceFlagSyncNext) {
pendingSyncFence = true;
fenceFlags = flags & (fenceFlagBlockBefore | fenceFlagBlockAfter | fenceFlagSyncNext);
fenceDataLen = len;
delete [] fenceData;
fenceData = NULL;
if (len > 0) {
fenceData = new char[len];
memcpy(fenceData, data, len);
}
return;
}
// We handle everything synchronously so we trivially honor these modes
flags = flags & (fenceFlagBlockBefore | fenceFlagBlockAfter);
writer()->writeFence(flags, len, data);
return;
}
if (len < 1)
vlog.error("Fence response of unexpected size received");
type = data[0];
switch (type) {
case 0:
// Initial dummy fence;
break;
case 1:
congestion.gotPong();
break;
default:
vlog.error("Fence response of unexpected type received");
}
}
void VNCSConnectionST::enableContinuousUpdates(bool enable,
int x, int y, int w, int h)
{
Rect rect;
if (!cp.supportsFence || !cp.supportsContinuousUpdates)
throw Exception("Client tried to enable continuous updates when not allowed");
continuousUpdates = enable;
rect.setXYWH(x, y, w, h);
cuRegion.reset(rect);
if (enable) {
requested.clear();
} else {
writer()->writeEndOfContinuousUpdates();
}
}
void VNCSConnectionST::handleClipboardRequest()
{
if (!(accessRights & AccessCutText)) return;
server->handleClipboardRequest(this);
}
void VNCSConnectionST::handleClipboardAnnounce(bool available)
{
if (!(accessRights & AccessCutText)) return;
if (!rfb::Server::acceptCutText) return;
server->handleClipboardAnnounce(this, available);
}
void VNCSConnectionST::handleClipboardData(const char* data, int len)
{
if (!(accessRights & AccessCutText)) return;
if (!rfb::Server::acceptCutText) return;
if (msSince(&lastClipboardOp) < (unsigned) rfb::Server::DLP_ClipDelay) {
vlog.info("DLP: client %s: refused to receive clipboard, too soon",
sock->getPeerAddress());
return;
}
const int origlen = len;
if (rfb::Server::DLP_ClipAcceptMax && len > rfb::Server::DLP_ClipAcceptMax)
len = rfb::Server::DLP_ClipAcceptMax;
cliplog(data, len, origlen, "received", sock->getPeerAddress());
gettimeofday(&lastClipboardOp, NULL);
server->handleClipboardData(this, data, len);
}
// supportsLocalCursor() is called whenever the status of
// cp.supportsLocalCursor has changed. If the client does now support local
// cursor, we make sure that the old server-side rendered cursor is cleaned up
// and the cursor is sent to the client.
void VNCSConnectionST::supportsLocalCursor()
{
bool hasRenderedCursor = !damagedCursorRegion.is_empty();
if (hasRenderedCursor && !needRenderedCursor())
removeRenderedCursor = true;
setCursor();
}
void VNCSConnectionST::supportsFence()
{
char type = 0;
writer()->writeFence(fenceFlagRequest, sizeof(type), &type);
}
void VNCSConnectionST::supportsContinuousUpdates()
{
// We refuse to use continuous updates if we cannot monitor the buffer
// usage using fences.
if (!cp.supportsFence)
return;
writer()->writeEndOfContinuousUpdates();
}
void VNCSConnectionST::supportsLEDState()
{
writer()->writeLEDState();
}
bool VNCSConnectionST::handleTimeout(Timer* t)
{
try {
if ((t == &congestionTimer) ||
(t == &losslessTimer))
writeFramebufferUpdate();
else if (t == &kbdLogTimer)
flushKeylog(sock->getPeerAddress());
} catch (rdr::Exception& e) {
close(e.str());
}
return false;
}
bool VNCSConnectionST::isShiftPressed()
{
std::map<rdr::U32, rdr::U32>::const_iterator iter;
for (iter = pressedKeys.begin(); iter != pressedKeys.end(); ++iter) {
if (iter->second == XK_Shift_L)
return true;
if (iter->second == XK_Shift_R)
return true;
}
return false;
}
bool VNCSConnectionST::getPerms(bool &write, bool &owner) const
{
bool found = false;
if (disablebasicauth) {
// We're running without basicauth
write = true;
return true;
}
if (user[0]) {
struct kasmpasswd_t *set = readkasmpasswd(kasmpasswdpath);
unsigned i;
for (i = 0; i < set->num; i++) {
if (!strcmp(set->entries[i].user, user)) {
write = set->entries[i].write;
owner = set->entries[i].owner;
found = true;
break;
}
}
free(set->entries);
free(set);
}
return found;
}
void VNCSConnectionST::writeRTTPing()
{
char type;
if (!cp.supportsFence)
return;
congestion.updatePosition(sock->outStream().length());
// We need to make sure any old update are already processed by the
// time we get the response back. This allows us to reliably throttle
// back on client overload, as well as network overload.
type = 1;
writer()->writeFence(fenceFlagRequest | fenceFlagBlockBefore,
sizeof(type), &type);
congestion.sentPing();
}
bool VNCSConnectionST::isCongested()
{
int eta;
congestionTimer.stop();
// Stuff still waiting in the send buffer?
sock->outStream().flush();
congestion.debugTrace("congestion-trace.csv", sock->getFd());
if (sock->outStream().bufferUsage() > 0)
return true;
if (!cp.supportsFence)
return false;
congestion.updatePosition(sock->outStream().length());
if (!congestion.isCongested())
return false;
eta = congestion.getUncongestedETA();
if (eta >= 0)
congestionTimer.start(eta);
if (eta > 1000 / rfb::Server::frameRate) {
struct timeval now;
gettimeofday(&now, NULL);
bstats[BS_NET_SLOW].push_back(now);
bstats_total[BS_NET_SLOW]++;
}
return true;
}
void VNCSConnectionST::writeFramebufferUpdate()
{
congestion.updatePosition(sock->outStream().length());
// We're in the middle of processing a command that's supposed to be
// synchronised. Allowing an update to slip out right now might violate
// that synchronisation.
if (syncFence)
return;
// We try to aggregate responses, so don't send out anything whilst we
// still have incoming messages. processMessages() will give us another
// chance to run once things are idle.
if (inProcessMessages)
return;
if (state() != RFBSTATE_NORMAL)
return;
if (requested.is_empty() && !continuousUpdates)
return;
// Check that we actually have some space on the link and retry in a
// bit if things are congested.
if (isCongested())
return;
// Check for permission changes?
if (needsPermCheck) {
needsPermCheck = false;
bool write, owner, ret;
ret = getPerms(write, owner);
if (!ret) {
close("User was deleted");
return;
} else if (!write) {
accessRights &= ~WRITER_PERMS;
} else {
accessRights |= WRITER_PERMS;
}
}
// Updates often consists of many small writes, and in continuous
// mode, we will also have small fence messages around the update. We
// need to aggregate these in order to not clog up TCP's congestion
// window.
sock->cork(true);
// First take care of any updates that cannot contain framebuffer data
// changes.
writeNoDataUpdate();
// Then real data (if possible)
writeDataUpdate();
sock->cork(false);
congestion.updatePosition(sock->outStream().length());
struct timeval now;
gettimeofday(&now, NULL);
bstats[BS_FRAME].push_back(now);
bstats_total[BS_FRAME]++;
}
void VNCSConnectionST::writeNoDataUpdate()
{
if (!writer()->needNoDataUpdate())
return;
writer()->writeNoDataUpdate();
// Make sure no data update is sent until next request
requested.clear();
}
void VNCSConnectionST::writeDataUpdate()
{
Region req, pending;
UpdateInfo ui;
bool needNewUpdateInfo;
const RenderedCursor *cursor;
size_t maxUpdateSize;
updates.enable_copyrect(cp.useCopyRect);
// See what the client has requested (if anything)
if (continuousUpdates)
req = cuRegion.union_(requested);
else
req = requested;
if (req.is_empty())
return;
// Get any framebuffer changes we haven't yet been informed of
pending = server->getPendingRegion();
// Get the lists of updates. Prior to exporting the data to the `ui' object,
// getUpdateInfo() will normalize the `updates' object such way that its
// `changed' and `copied' regions would not intersect.
updates.getUpdateInfo(&ui, req);
needNewUpdateInfo = false;
// If the previous position of the rendered cursor overlaps the source of the
// copy, then when the copy happens the corresponding rectangle in the
// destination will be wrong, so add it to the changed region.
if (!ui.copied.is_empty() && !damagedCursorRegion.is_empty()) {
Region bogusCopiedCursor;
bogusCopiedCursor = damagedCursorRegion;
bogusCopiedCursor.translate(ui.copy_delta);
bogusCopiedCursor.assign_intersect(server->pb->getRect());
if (!ui.copied.intersect(bogusCopiedCursor).is_empty()) {
updates.add_changed(bogusCopiedCursor);
needNewUpdateInfo = true;
}
}
// If we need to remove the old rendered cursor, just add the region to
// the changed region.
if (removeRenderedCursor) {
updates.add_changed(damagedCursorRegion);
needNewUpdateInfo = true;
damagedCursorRegion.clear();
removeRenderedCursor = false;
}
// If we need a full cursor update then make sure its entire region
// is marked as changed.
if (updateRenderedCursor) {
updates.add_changed(server->getRenderedCursor()->getEffectiveRect());
needNewUpdateInfo = true;
updateRenderedCursor = false;
}
// The `updates' object could change, make sure we have valid update info.
if (needNewUpdateInfo)
updates.getUpdateInfo(&ui, req);
// If there are queued updates then we cannot safely send an update
// without risking a partially updated screen
if (!pending.is_empty()) {
// However we might still be able to send a lossless refresh
req.assign_subtract(pending);
req.assign_subtract(ui.changed);
req.assign_subtract(ui.copied);
if (copypassed.size()) {
Region everything;
for (std::vector<CopyPassRect>::const_iterator it = copypassed.begin();
it != copypassed.end(); it++) {
everything.assign_union(it->rect);
}
req.assign_subtract(everything);
}
ui.changed.clear();
ui.copied.clear();
}
// Does the client need a server-side rendered cursor?
cursor = NULL;
if (needRenderedCursor()) {
Rect renderedCursorRect;
cursor = server->getRenderedCursor();
renderedCursorRect = cursor->getEffectiveRect();
// Check that we don't try to copy over the cursor area, and
// if that happens we need to treat it as changed so that we can
// re-render it
if (!ui.copied.intersect(renderedCursorRect).is_empty()) {
ui.changed.assign_union(ui.copied.intersect(renderedCursorRect));
ui.copied.assign_subtract(renderedCursorRect);
}
// Track where we've rendered the cursor
damagedCursorRegion.assign_union(ui.changed.intersect(renderedCursorRect));
}
ui.copypassed = copypassed;
if (!pending.is_empty())
ui.copypassed.clear();
// Return if there is nothing to send the client.
const unsigned losslessThreshold = 80 + 2 * 1000 / Server::frameRate;
if (ui.is_empty() && !writer()->needFakeUpdate() &&
(!encodeManager.needsLosslessRefresh(req) ||
msSince(&lastRealUpdate) < losslessThreshold))
return;
writeRTTPing();
// FIXME: If continuous updates aren't used then the client might
// be slower than frameRate in its requests and we could
// afford a larger update size
// FIXME: Bandwidth estimation without congestion control
maxUpdateSize = congestion.getBandwidth() *
server->msToNextUpdate() / 1000;
if (!ui.is_empty()) {
encodeManager.writeUpdate(ui, server->getPixelBuffer(), cursor, maxUpdateSize);
copypassed.clear();
gettimeofday(&lastRealUpdate, NULL);
losslessTimer.start(losslessThreshold);
const unsigned ms = encodeManager.getEncodingTime();
const unsigned limit = 1000 / rfb::Server::frameRate;
if (ms >= limit) {
bstats[BS_CPU_SLOW].push_back(lastRealUpdate);
bstats_total[BS_CPU_SLOW]++;
// If it was several frames' worth, add several so as to react faster
int i = ms / limit;
i--;
for (; i > 0; i--) {
bstats[BS_CPU_SLOW].push_back(lastRealUpdate);
bstats_total[BS_CPU_SLOW]++;
bstats[BS_FRAME].push_back(lastRealUpdate);
bstats_total[BS_FRAME]++;
}
} else if (ms >= limit * 0.8f) {
bstats[BS_CPU_CLOSE].push_back(lastRealUpdate);
bstats_total[BS_CPU_CLOSE]++;
}
} else {
encodeManager.writeLosslessRefresh(req, server->getPixelBuffer(),
cursor, maxUpdateSize);
}
writeRTTPing();
// The request might be for just part of the screen, so we cannot
// just clear the entire update tracker.
updates.subtract(req);
requested.clear();
}
void VNCSConnectionST::screenLayoutChange(rdr::U16 reason)
{
if (!authenticated())
return;
cp.screenLayout = server->screenLayout;
if (state() != RFBSTATE_NORMAL)
return;
writer()->writeExtendedDesktopSize(reason, 0, cp.width, cp.height,
cp.screenLayout);
}
static const unsigned recentSecs = 10;
static void pruneStatList(std::list<struct timeval> &list, const struct timeval &now) {
std::list<struct timeval>::iterator it;
for (it = list.begin(); it != list.end(); ) {
if ((*it).tv_sec + recentSecs < now.tv_sec)
it = list.erase(it);
else
it++;
}
}
void VNCSConnectionST::sendStats() {
char buf[1024];
struct timeval now;
// Prune too old stats from the recent lists
gettimeofday(&now, NULL);
pruneStatList(bstats[BS_CPU_CLOSE], now);
pruneStatList(bstats[BS_CPU_SLOW], now);
pruneStatList(bstats[BS_NET_SLOW], now);
pruneStatList(bstats[BS_FRAME], now);
const unsigned minuteframes = bstats[BS_FRAME].size();
// Calculate stats
float cpu_recent = bstats[BS_CPU_SLOW].size() + bstats[BS_CPU_CLOSE].size() * 0.2f;
cpu_recent /= minuteframes;
float cpu_total = bstats_total[BS_CPU_SLOW] + bstats_total[BS_CPU_CLOSE] * 0.2f;
cpu_total /= bstats_total[BS_FRAME];
float net_recent = bstats[BS_NET_SLOW].size();
net_recent /= minuteframes;
if (net_recent > 1)
net_recent = 1;
float net_total = bstats_total[BS_NET_SLOW];
net_total /= bstats_total[BS_FRAME];
if (net_total > 1)
net_total = 1;
#define ten(x) (10 - x * 10.0f)
sprintf(buf, "[ %.1f, %.1f, %.1f, %.1f ]",
ten(cpu_recent), ten(cpu_total),
ten(net_recent), ten(net_total));
#undef ten
vlog.info("Sending client stats:\n%s\n", buf);
writer()->writeStats(buf, strlen(buf));
}
// setCursor() is called whenever the cursor has changed shape or pixel format.
// If the client supports local cursor then it will arrange for the cursor to
// be sent to the client.
void VNCSConnectionST::setCursor()
{
if (state() != RFBSTATE_NORMAL)
return;
// We need to blank out the client's cursor or there will be two
if (needRenderedCursor()) {
cp.setCursor(emptyCursor);
clientHasCursor = false;
} else {
cp.setCursor(*server->cursor);
clientHasCursor = true;
}
if (!writer()->writeSetCursorWithAlpha()) {
if (!writer()->writeSetCursor()) {
if (!writer()->writeSetXCursor()) {
// No client support
return;
}
}
}
}
// setCursorPos() is called whenever the cursor has changed position by the
// server. If the client supports being informed about these changes then it
// will arrange for the new cursor position to be sent to the client.
void VNCSConnectionST::setCursorPos()
{
if (state() != RFBSTATE_NORMAL)
return;
if (cp.supportsCursorPosition) {
cp.setCursorPos(server->cursorPos);
writer()->writeCursorPos();
}
}
void VNCSConnectionST::setDesktopName(const char *name)
{
cp.setName(name);
if (state() != RFBSTATE_NORMAL)
return;
if (!writer()->writeSetDesktopName()) {
fprintf(stderr, "Client does not support desktop rename\n");
return;
}
}
void VNCSConnectionST::setLEDState(unsigned int ledstate)
{
if (state() != RFBSTATE_NORMAL)
return;
cp.setLEDState(ledstate);
writer()->writeLEDState();
}
void VNCSConnectionST::setSocketTimeouts()
{
int timeoutms = rfb::Server::clientWaitTimeMillis;
soonestTimeout(&timeoutms, secsToMillis(rfb::Server::idleTimeout));
if (timeoutms == 0)
timeoutms = -1;
sock->inStream().setTimeout(timeoutms);
sock->outStream().setTimeout(timeoutms);
}
char* VNCSConnectionST::getStartTime()
{
char* result = ctime(&startTime);
result[24] = '\0';
return result;
}
void VNCSConnectionST::setStatus(int status)
{
switch (status) {
case 0:
accessRights = accessRights | AccessPtrEvents | AccessKeyEvents | AccessView;
break;
case 1:
accessRights = (accessRights & ~(AccessPtrEvents | AccessKeyEvents)) | AccessView;
break;
case 2:
accessRights = accessRights & ~(AccessPtrEvents | AccessKeyEvents | AccessView);
break;
}
framebufferUpdateRequest(server->pb->getRect(), false);
}
int VNCSConnectionST::getStatus()
{
if ((accessRights & (AccessPtrEvents | AccessKeyEvents | AccessView)) == 0x0007)
return 0;
if ((accessRights & (AccessPtrEvents | AccessKeyEvents | AccessView)) == 0x0001)
return 1;
if ((accessRights & (AccessPtrEvents | AccessKeyEvents | AccessView)) == 0x0000)
return 2;
return 4;
}
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