/*
* Perform OPOST processing. Returns -1 when the output device is
* full and the character must be retried.
*/
static int opost(unsigned char c, struct tty_struct *tty)
{
int space, spaces;
space = tty->driver.write_room(tty);
if (!space)
return -1;
if (O_OPOST(tty)) {
switch (c) {
case '\n':
if (O_ONLRET(tty))
tty->column = 0;
if (O_ONLCR(tty)) {
if (space < 2)
return -1;
tty->driver.put_char(tty, '\r');
tty->column = 0;
}
tty->canon_column = tty->column;
break;
case '\r':
if (O_ONOCR(tty) && tty->column == 0)
return 0;
if (O_OCRNL(tty)) {
c = '\n';
if (O_ONLRET(tty))
tty->canon_column = tty->column = 0;
break;
}
tty->canon_column = tty->column = 0;
break;
case '\t':
spaces = 8 - (tty->column & 7);
if (O_TABDLY(tty) == XTABS) {
if (space < spaces)
return -1;
tty->column += spaces;
tty->driver.write(tty, 0, " ", spaces);
return 0;
}
tty->column += spaces;
break;
case '\b':
if (tty->column > 0)
tty->column--;
break;
default:
if (O_OLCUC(tty))
c = toupper(c);
if (!iscntrl(c))
tty->column++;
break;
}
}
tty->driver.put_char(tty, c);
return 0;
}
static int opost(unsigned char c, struct tty_struct *tty)
{
if (FULL(&tty->write_q))
return -1;
if (O_OPOST(tty)) {
switch (c) {
case '\n':
if (O_ONLRET(tty))
tty->column = 0;
if (O_ONLCR(tty)) {
if (LEFT(&tty->write_q) < 2)
return -1;
put_tty_queue('\r', &tty->write_q);
tty->column = 0;
}
tty->canon_column = tty->column;
break;
case '\r':
if (O_ONOCR(tty) && tty->column == 0)
return 0;
if (O_OCRNL(tty)) {
c = '\n';
if (O_ONLRET(tty))
tty->canon_column = tty->column = 0;
break;
}
tty->canon_column = tty->column = 0;
break;
case '\t':
if (O_TABDLY(tty) == XTABS) {
if (LEFT(&tty->write_q) < 8)
return -1;
do
put_tty_queue(' ', &tty->write_q);
while (++tty->column % 8);
return 0;
}
tty->column = (tty->column | 7) + 1;
break;
case '\b':
if (tty->column > 0)
tty->column--;
break;
default:
if (O_OLCUC(tty))
c = toupper(c);
if (!iscntrl(c))
tty->column++;
break;
}
}
put_tty_queue(c, &tty->write_q);
return 0;
}
static int write_chan(struct tty_struct * tty, struct file * file,
const unsigned char * buf, unsigned int nr)
{
struct wait_queue wait = { current, NULL };
int c;
const unsigned char *b = buf;
int retval = 0;
/* Job control check -- must be done at start (POSIX.1 7.1.1.4). */
if (L_TOSTOP(tty) && file->f_inode->i_rdev != CONSOLE_DEV) {
retval = tty_check_change(tty);
if (retval)
return retval;
}
add_wait_queue(&tty->write_wait, &wait);
while (1) {
current->state = TASK_INTERRUPTIBLE;
if (current->signal & ~current->blocked) {
retval = -ERESTARTSYS;
break;
}
if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) {
retval = -EIO;
break;
}
if (O_OPOST(tty)) {
while (nr > 0) {
c = get_user(b);
if (opost(c, tty) < 0)
break;
b++; nr--;
}
if (tty->driver.flush_chars)
tty->driver.flush_chars(tty);
} else {
c = tty->driver.write(tty, 1, b, nr);
b += c;
nr -= c;
}
if (!nr)
break;
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
schedule();
}
current->state = TASK_RUNNING;
remove_wait_queue(&tty->write_wait, &wait);
return (b - buf) ? b - buf : retval;
}
static void process_echoes(struct tty_struct *tty)
{
int space, nr;
unsigned char c;
unsigned char *cp, *buf_end;
if (!tty->echo_cnt)
return;
mutex_lock(&tty->output_lock);
mutex_lock(&tty->echo_lock);
space = tty_write_room(tty);
buf_end = tty->echo_buf + N_TTY_BUF_SIZE;
cp = tty->echo_buf + tty->echo_pos;
nr = tty->echo_cnt;
while (nr > 0) {
c = *cp;
if (c == ECHO_OP_START) {
unsigned char op;
unsigned char *opp;
int no_space_left = 0;
opp = cp + 1;
if (opp == buf_end)
opp -= N_TTY_BUF_SIZE;
op = *opp;
switch (op) {
unsigned int num_chars, num_bs;
case ECHO_OP_ERASE_TAB:
if (++opp == buf_end)
opp -= N_TTY_BUF_SIZE;
num_chars = *opp;
if (!(num_chars & 0x80))
num_chars += tty->canon_column;
num_bs = 8 - (num_chars & 7);
if (num_bs > space) {
no_space_left = 1;
break;
}
space -= num_bs;
while (num_bs--) {
tty_put_char(tty, '\b');
if (tty->column > 0)
tty->column--;
}
cp += 3;
nr -= 3;
break;
case ECHO_OP_SET_CANON_COL:
tty->canon_column = tty->column;
cp += 2;
nr -= 2;
break;
case ECHO_OP_MOVE_BACK_COL:
if (tty->column > 0)
tty->column--;
cp += 2;
nr -= 2;
break;
case ECHO_OP_START:
if (!space) {
no_space_left = 1;
break;
}
tty_put_char(tty, ECHO_OP_START);
tty->column++;
space--;
cp += 2;
nr -= 2;
break;
default:
if (space < 2) {
no_space_left = 1;
break;
}
tty_put_char(tty, '^');
tty_put_char(tty, op ^ 0100);
tty->column += 2;
space -= 2;
cp += 2;
nr -= 2;
}
if (no_space_left)
break;
} else {
if (O_OPOST(tty) &&
!(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
int retval = do_output_char(c, tty, space);
if (retval < 0)
break;
space -= retval;
} else {
if (!space)
break;
tty_put_char(tty, c);
space -= 1;
}
cp += 1;
nr -= 1;
}
if (cp >= buf_end)
cp -= N_TTY_BUF_SIZE;
}
if (nr == 0) {
tty->echo_pos = 0;
tty->echo_cnt = 0;
tty->echo_overrun = 0;
} else {
int num_processed = tty->echo_cnt - nr;
tty->echo_pos += num_processed;
tty->echo_pos &= N_TTY_BUF_SIZE - 1;
tty->echo_cnt = nr;
if (num_processed > 0)
tty->echo_overrun = 0;
}
mutex_unlock(&tty->echo_lock);
mutex_unlock(&tty->output_lock);
if (tty->ops->flush_chars)
tty->ops->flush_chars(tty);
}
static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
const unsigned char *buf, size_t nr)
{
const unsigned char *b = buf;
DECLARE_WAITQUEUE(wait, current);
int c;
ssize_t retval = 0;
if (L_TOSTOP(tty) && file->f_op->write != redirected_tty_write) {
retval = tty_check_change(tty);
if (retval)
return retval;
}
process_echoes(tty);
add_wait_queue(&tty->write_wait, &wait);
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) {
retval = -EIO;
break;
}
if (O_OPOST(tty) && !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
while (nr > 0) {
ssize_t num = process_output_block(tty, b, nr);
if (num < 0) {
if (num == -EAGAIN)
break;
retval = num;
goto break_out;
}
b += num;
nr -= num;
if (nr == 0)
break;
c = *b;
if (process_output(c, tty) < 0)
break;
b++; nr--;
}
if (tty->ops->flush_chars)
tty->ops->flush_chars(tty);
} else {
while (nr > 0) {
c = tty->ops->write(tty, b, nr);
if (c < 0) {
retval = c;
goto break_out;
}
if (!c)
break;
b += c;
nr -= c;
}
}
if (!nr)
break;
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
schedule();
}
break_out:
__set_current_state(TASK_RUNNING);
remove_wait_queue(&tty->write_wait, &wait);
if (b - buf != nr && tty->fasync)
set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
return (b - buf) ? b - buf : retval;
}
static ssize_t write_chan(struct tty_struct * tty, struct file * file,
const unsigned char * buf, size_t nr)
{
const unsigned char *b = buf;
struct wait_queue wait = { current, NULL };
int c;
ssize_t retval = 0;
/* Job control check -- must be done at start (POSIX.1 7.1.1.4). */
if (L_TOSTOP(tty) &&
file->f_dentry->d_inode->i_rdev != CONSOLE_DEV &&
file->f_dentry->d_inode->i_rdev != SYSCONS_DEV) {
retval = tty_check_change(tty);
if (retval)
return retval;
}
add_wait_queue(&tty->write_wait, &wait);
while (1) {
current->state = TASK_INTERRUPTIBLE;
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) {
retval = -EIO;
break;
}
if (O_OPOST(tty) && !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
while (nr > 0) {
ssize_t num = opost_block(tty, b, nr);
if (num < 0) {
retval = num;
goto break_out;
}
b += num;
nr -= num;
if (nr == 0)
break;
current->state = TASK_RUNNING;
get_user(c, b);
current->state = TASK_INTERRUPTIBLE;
if (opost(c, tty) < 0)
break;
b++; nr--;
}
if (tty->driver.flush_chars)
tty->driver.flush_chars(tty);
} else {
current->state = TASK_RUNNING;
c = tty->driver.write(tty, 1, b, nr);
current->state = TASK_INTERRUPTIBLE;
if (c < 0) {
retval = c;
goto break_out;
}
b += c;
nr -= c;
}
if (!nr)
break;
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
schedule();
}
break_out:
current->state = TASK_RUNNING;
remove_wait_queue(&tty->write_wait, &wait);
return (b - buf) ? b - buf : retval;
}
static ssize_t write_chan(struct tty_struct * tty, struct file * file,
const unsigned char * buf, size_t nr)
{
const unsigned char *b = buf;
DECLARE_WAITQUEUE(wait, current);
int c;
ssize_t retval = 0;
int transaction_commit = committing_transaction();
/* Job control check -- must be done at start (POSIX.1 7.1.1.4). */
if ((!transaction_commit) &&
L_TOSTOP(tty) && file->f_op->write != redirected_tty_write) {
retval = tty_check_change(tty);
if (retval)
return retval;
}
add_wait_queue(&tty->write_wait, &wait);
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
if ((!transaction_commit) &&
(tty_hung_up_p(file) || (tty->link && !tty->link->count))) {
retval = -EIO;
break;
}
if (O_OPOST(tty) && !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
while (nr > 0) {
ssize_t num = opost_block(tty, b, nr);
if (num < 0) {
if (num == -EAGAIN)
break;
retval = num;
goto break_out;
}
b += num;
nr -= num;
if (nr == 0)
break;
c = *b;
if (opost(c, tty) < 0)
break;
b++; nr--;
}
if (tty->driver->flush_chars)
tty->driver->flush_chars(tty);
} else {
while (nr > 0) {
c = tty->driver->write(tty, b, nr);
if (c < 0) {
retval = c;
goto break_out;
}
if (!c)
break;
b += c;
nr -= c;
}
}
if (!nr)
break;
if ((!transaction_commit) &&
(tx_cache_get_file_ro(file)->f_flags & O_NONBLOCK)) {
retval = -EAGAIN;
break;
}
schedule();
}
break_out:
__set_current_state(TASK_RUNNING);
remove_wait_queue(&tty->write_wait, &wait);
return (b - buf) ? b - buf : retval;
}
