kwin/virtual_terminal.cpp
2020-08-07 19:57:56 +00:00

215 lines
4.8 KiB
C++

/*
KWin - the KDE window manager
This file is part of the KDE project.
SPDX-FileCopyrightText: 2015 Martin Gräßlin <mgraesslin@kde.org>
SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "virtual_terminal.h"
// kwin
#include "logind.h"
#include "main.h"
#include "utils.h"
// Qt
#include <QDebug>
#include <QSocketNotifier>
// linux
#ifdef Q_OS_LINUX
#include <linux/major.h>
#include <linux/kd.h>
#include <linux/vt.h>
#include <sys/sysmacros.h>
#endif
#ifdef Q_OS_FREEBSD
#include <sys/consio.h>
#endif
// system
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/signalfd.h>
#include <sys/stat.h>
// c++
#include <csignal>
#define RELEASE_SIGNAL SIGUSR1
#define ACQUISITION_SIGNAL SIGUSR2
namespace KWin
{
KWIN_SINGLETON_FACTORY(VirtualTerminal)
VirtualTerminal::VirtualTerminal(QObject *parent)
: QObject(parent)
{
}
void VirtualTerminal::init()
{
auto logind = LogindIntegration::self();
if (logind->vt() != -1) {
setup(logind->vt());
}
connect(logind, &LogindIntegration::virtualTerminalChanged, this, &VirtualTerminal::setup);
if (logind->isConnected()) {
logind->takeControl();
} else {
connect(logind, &LogindIntegration::connectedChanged, logind, &LogindIntegration::takeControl);
}
}
VirtualTerminal::~VirtualTerminal()
{
s_self = nullptr;
closeFd();
}
static bool isTty(int fd)
{
if (fd < 0) {
return false;
}
struct stat st;
if (fstat(fd, &st) == -1) {
return false;
}
#ifdef Q_OS_LINUX
// Not a TTY device or weird vt number, skip it
if (major(st.st_rdev) != TTY_MAJOR || minor (st.st_rdev) <= 0 || minor(st.st_rdev) >= 64) {
return false;
}
#endif
// FreeBSD doesn't have a notion of major device number, so nothing
// to check. isatty() might not do the trick.
return true;
}
void VirtualTerminal::setup(int vtNr)
{
if (m_vt != -1) {
return;
}
if (vtNr == -1) {
// error condition
return;
}
QString ttyName = QStringLiteral(KWIN_TTY_PREFIX "%1").arg(vtNr);
m_vt = open(ttyName.toUtf8().constData(), O_RDWR|O_CLOEXEC|O_NONBLOCK);
if (m_vt < 0) {
qCWarning(KWIN_CORE) << "Failed to open tty" << vtNr;
return;
}
if (!isTty(m_vt)) {
qCWarning(KWIN_CORE) << vtNr << " is no tty";
closeFd();
return;
}
if (ioctl(m_vt, KDSETMODE, KD_GRAPHICS) < 0) {
qCWarning(KWIN_CORE()) << "Failed to set tty " << vtNr << " in graphics mode";
closeFd();
return;
}
if (!createSignalHandler()) {
qCWarning(KWIN_CORE) << "Failed to create signalfd";
closeFd();
return;
}
vt_mode mode = {
VT_PROCESS,
0,
RELEASE_SIGNAL,
ACQUISITION_SIGNAL,
0
};
if (ioctl(m_vt, VT_SETMODE, &mode) < 0) {
qCWarning(KWIN_CORE) << "Failed to take over virtual terminal";
closeFd();
return;
}
m_vtNumber = vtNr;
setActive(true);
emit kwinApp()->virtualTerminalCreated();
}
void VirtualTerminal::closeFd()
{
if (m_vt < 0) {
return;
}
if (m_notifier) {
const int sfd = m_notifier->socket();
delete m_notifier;
m_notifier = nullptr;
close(sfd);
}
close(m_vt);
m_vt = -1;
}
bool VirtualTerminal::createSignalHandler()
{
if (m_notifier) {
return false;
}
sigset_t mask;
sigemptyset(&mask);
sigaddset(&mask, RELEASE_SIGNAL);
sigaddset(&mask, ACQUISITION_SIGNAL);
pthread_sigmask(SIG_BLOCK, &mask, nullptr);
const int fd = signalfd(-1, &mask, SFD_NONBLOCK | SFD_CLOEXEC);
if (fd < 0) {
return false;
}
m_notifier = new QSocketNotifier(fd, QSocketNotifier::Read, this);
connect(m_notifier, &QSocketNotifier::activated, this,
[this] {
if (m_vt < 0) {
return;
}
while (true) {
signalfd_siginfo sigInfo;
if (read(m_notifier->socket(), &sigInfo, sizeof(sigInfo)) != sizeof(sigInfo)) {
break;
}
switch (sigInfo.ssi_signo) {
case RELEASE_SIGNAL:
setActive(false);
ioctl(m_vt, VT_RELDISP, 1);
break;
case ACQUISITION_SIGNAL:
ioctl(m_vt, VT_RELDISP, VT_ACKACQ);
setActive(true);
break;
}
}
}
);
return true;
}
void VirtualTerminal::activate(int vt)
{
if (m_vt < 0) {
return;
}
if (vt == m_vtNumber) {
return;
}
ioctl(m_vt, VT_ACTIVATE, vt);
setActive(false);
}
void VirtualTerminal::setActive(bool active)
{
if (m_active == active) {
return;
}
m_active = active;
emit activeChanged(m_active);
}
}