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serenity/Kernel/TTY/TTY.cpp
Andreas Kling 94ca55cefd Meta: Add license header to source files
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.

For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.

Going forward, all new source files should include a license header.
2020-01-18 09:45:54 +01:00

345 lines
9.3 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "Process.h"
#include <Kernel/TTY/TTY.h>
#include <LibC/errno_numbers.h>
#include <LibC/signal_numbers.h>
#include <LibC/sys/ioctl_numbers.h>
//#define TTY_DEBUG
TTY::TTY(unsigned major, unsigned minor)
: CharacterDevice(major, minor)
{
set_default_termios();
}
TTY::~TTY()
{
}
void TTY::set_default_termios()
{
memset(&m_termios, 0, sizeof(m_termios));
m_termios.c_lflag |= ISIG | ECHO | ICANON;
static const char default_cc[32] = "\003\034\010\025\004\0\1\0\021\023\032\0\022\017\027\026\0";
memcpy(m_termios.c_cc, default_cc, sizeof(default_cc));
}
ssize_t TTY::read(FileDescription&, u8* buffer, ssize_t size)
{
if (m_input_buffer.size() < size)
size = m_input_buffer.size();
if (in_canonical_mode()) {
int i = 0;
for (; i < size; i++) {
u8 ch = m_input_buffer.dequeue();
if (ch == '\0') {
//Here we handle a ^D line, so we don't add the
//character to the output.
m_available_lines--;
break;
} else if (ch == '\n' || is_eol(ch)) {
buffer[i] = ch;
i++;
m_available_lines--;
break;
}
buffer[i] = ch;
}
return i;
}
for (int i = 0; i < size; i++)
buffer[i] = m_input_buffer.dequeue();
return size;
}
ssize_t TTY::write(FileDescription&, const u8* buffer, ssize_t size)
{
#ifdef TTY_DEBUG
dbgprintf("TTY::write {%u} ", size);
for (size_t i = 0; i < size; ++i) {
dbgprintf("%b ", buffer[i]);
}
dbgprintf("\n");
#endif
on_tty_write(buffer, size);
return size;
}
bool TTY::can_read(const FileDescription&) const
{
if (in_canonical_mode()) {
return m_available_lines > 0;
}
return !m_input_buffer.is_empty();
}
bool TTY::can_write(const FileDescription&) const
{
return true;
}
bool TTY::is_eol(u8 ch) const
{
return ch == m_termios.c_cc[VEOL];
}
bool TTY::is_eof(u8 ch) const
{
return ch == m_termios.c_cc[VEOF];
}
bool TTY::is_kill(u8 ch) const
{
return ch == m_termios.c_cc[VKILL];
}
bool TTY::is_erase(u8 ch) const
{
return ch == m_termios.c_cc[VERASE];
}
bool TTY::is_werase(u8 ch) const
{
return ch == m_termios.c_cc[VWERASE];
}
void TTY::emit(u8 ch)
{
if (should_generate_signals()) {
if (ch == m_termios.c_cc[VINTR]) {
dbg() << tty_name() << ": VINTR pressed!";
generate_signal(SIGINT);
return;
}
if (ch == m_termios.c_cc[VQUIT]) {
dbg() << tty_name() << ": VQUIT pressed!";
generate_signal(SIGQUIT);
return;
}
if (ch == m_termios.c_cc[VSUSP]) {
dbg() << tty_name() << ": VSUSP pressed!";
generate_signal(SIGTSTP);
return;
}
}
if (in_canonical_mode()) {
if (is_eof(ch)) {
m_available_lines++;
//We use '\0' to delimit the end
//of a line.
m_input_buffer.enqueue('\0');
return;
}
if (is_kill(ch)) {
kill_line();
return;
}
if (is_erase(ch)) {
do_backspace();
return;
}
if (is_werase(ch)) {
erase_word();
return;
}
if (ch == '\n' || is_eol(ch)) {
m_available_lines++;
}
}
m_input_buffer.enqueue(ch);
echo(ch);
}
bool TTY::can_do_backspace() const
{
//can't do back space if we're empty. Plus, we don't want to
//removing any lines "commited" by newlines or ^D.
if (!m_input_buffer.is_empty() && !is_eol(m_input_buffer.last()) && m_input_buffer.last() != '\0') {
return true;
}
return false;
}
void TTY::do_backspace()
{
if (can_do_backspace()) {
m_input_buffer.dequeue_end();
echo(m_termios.c_cc[VERASE]);
}
}
// TODO: Currently, both erase_word() and kill_line work by sending
// a lot of VERASE characters; this is done because Terminal.cpp
// doesn't currently support VWERASE and VKILL. When these are
// implemented we could just send a VKILL or VWERASE.
void TTY::erase_word()
{
//Note: if we have leading whitespace before the word
//we want to delete we have to also delete that.
bool first_char = false;
while (can_do_backspace()) {
u8 ch = m_input_buffer.last();
if (ch == ' ' && first_char)
break;
if (ch != ' ')
first_char = true;
m_input_buffer.dequeue_end();
echo(m_termios.c_cc[VERASE]);
}
}
void TTY::kill_line()
{
while (can_do_backspace()) {
m_input_buffer.dequeue_end();
echo(m_termios.c_cc[VERASE]);
}
}
void TTY::generate_signal(int signal)
{
if (!pgid())
return;
if (should_flush_on_signal())
flush_input();
dbg() << tty_name() << ": Send signal " << signal << " to everyone in pgrp " << pgid();
InterruptDisabler disabler; // FIXME: Iterate over a set of process handles instead?
Process::for_each_in_pgrp(pgid(), [&](auto& process) {
dbg() << tty_name() << ": Send signal " << signal << " to " << process;
process.send_signal(signal, nullptr);
return IterationDecision::Continue;
});
}
void TTY::flush_input()
{
m_available_lines = 0;
m_input_buffer.clear();
}
void TTY::set_termios(const termios& t)
{
m_termios = t;
#ifdef TTY_DEBUG
dbg() << tty_name() << " set_termios: "
<< "ECHO=" << should_echo_input()
<< ", ISIG=" << should_generate_signals()
<< ", ICANON=" << in_canonical_mode()
<< ", ECHOE=" << ((m_termios.c_lflag & ECHOE) != 0)
<< ", ECHOK=" << ((m_termios.c_lflag & ECHOK) != 0)
<< ", ECHONL=" << ((m_termios.c_lflag & ECHONL) != 0)
<< ", ISTRIP=" << ((m_termios.c_iflag & ISTRIP) != 0)
<< ", ICRNL=" << ((m_termios.c_iflag & ICRNL) != 0)
<< ", INLCR=" << ((m_termios.c_iflag & INLCR) != 0)
<< ", IGNCR=" << ((m_termios.c_iflag & IGNCR) != 0);
#endif
}
int TTY::ioctl(FileDescription&, unsigned request, unsigned arg)
{
REQUIRE_PROMISE(tty);
auto& process = current->process();
pid_t pgid;
termios* tp;
winsize* ws;
#if 0
// FIXME: When should we block things?
// How do we make this work together with MasterPTY forwarding to us?
if (process.tty() && process.tty() != this) {
return -ENOTTY;
}
#endif
switch (request) {
case TIOCGPGRP:
return m_pgid;
case TIOCSPGRP:
// FIXME: Validate pgid fully.
pgid = static_cast<pid_t>(arg);
if (pgid < 0)
return -EINVAL;
m_pgid = pgid;
return 0;
case TCGETS:
tp = reinterpret_cast<termios*>(arg);
if (!process.validate_write(tp, sizeof(termios)))
return -EFAULT;
*tp = m_termios;
return 0;
case TCSETS:
case TCSETSF:
case TCSETSW:
tp = reinterpret_cast<termios*>(arg);
if (!process.validate_read(tp, sizeof(termios)))
return -EFAULT;
set_termios(*tp);
return 0;
case TIOCGWINSZ:
ws = reinterpret_cast<winsize*>(arg);
if (!process.validate_write(ws, sizeof(winsize)))
return -EFAULT;
ws->ws_row = m_rows;
ws->ws_col = m_columns;
return 0;
case TIOCSWINSZ:
ws = reinterpret_cast<winsize*>(arg);
if (!process.validate_read(ws, sizeof(winsize)))
return -EFAULT;
if (ws->ws_col == m_columns && ws->ws_row == m_rows)
return 0;
m_rows = ws->ws_row;
m_columns = ws->ws_col;
generate_signal(SIGWINCH);
return 0;
case TIOCSCTTY:
process.set_tty(this);
return 0;
case TIOCNOTTY:
process.set_tty(nullptr);
return 0;
}
ASSERT_NOT_REACHED();
return -EINVAL;
}
void TTY::set_size(unsigned short columns, unsigned short rows)
{
m_rows = rows;
m_columns = columns;
}
void TTY::hang_up()
{
generate_signal(SIGHUP);
}