static int copy_from_read_buf(struct tty_struct *tty,
unsigned char __user **b,
size_t *nr)
{
int retval;
size_t n;
unsigned long flags;
retval = 0;
spin_lock_irqsave(&tty->read_lock, flags);
n = min(tty->read_cnt, N_TTY_BUF_SIZE - tty->read_tail);
n = min(*nr, n);
spin_unlock_irqrestore(&tty->read_lock, flags);
if (n) {
retval = copy_to_user(*b, &tty->read_buf[tty->read_tail], n);
n -= retval;
tty_audit_add_data(tty, &tty->read_buf[tty->read_tail], n);
spin_lock_irqsave(&tty->read_lock, flags);
tty->read_tail = (tty->read_tail + n) & (N_TTY_BUF_SIZE-1);
tty->read_cnt -= n;
if (L_EXTPROC(tty) && tty->icanon && n == 1) {
if (!tty->read_cnt && (*b)[n-1] == EOF_CHAR(tty))
n--;
}
spin_unlock_irqrestore(&tty->read_lock, flags);
*b += n;
*nr -= n;
}
return retval;
}
static void pty_set_termios(struct tty_struct *tty,
struct ktermios *old_termios)
{
/* See if packet mode change of state. */
if (tty->link && tty->link->packet) {
int extproc = (old_termios->c_lflag & EXTPROC) | L_EXTPROC(tty);
int old_flow = ((old_termios->c_iflag & IXON) &&
(old_termios->c_cc[VSTOP] == '\023') &&
(old_termios->c_cc[VSTART] == '\021'));
int new_flow = (I_IXON(tty) &&
STOP_CHAR(tty) == '\023' &&
START_CHAR(tty) == '\021');
if ((old_flow != new_flow) || extproc) {
spin_lock_irq(&tty->ctrl_lock);
if (old_flow != new_flow) {
tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
if (new_flow)
tty->ctrl_status |= TIOCPKT_DOSTOP;
else
tty->ctrl_status |= TIOCPKT_NOSTOP;
}
if (extproc)
tty->ctrl_status |= TIOCPKT_IOCTL;
spin_unlock_irq(&tty->ctrl_lock);
wake_up_interruptible(&tty->link->read_wait);
}
}
tty->termios.c_cflag &= ~(CSIZE | PARENB);
tty->termios.c_cflag |= (CS8 | CREAD);
}
static inline int input_available_p(struct tty_struct *tty, int amt)
{
tty_flush_to_ldisc(tty);
if (tty->icanon && !L_EXTPROC(tty)) {
if (tty->canon_data)
return 1;
} else if (tty->read_cnt >= (amt ? amt : 1))
return 1;
return 0;
}
static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
char *fp, int count)
{
const unsigned char *p;
char *f, flags = TTY_NORMAL;
int i;
char buf[64];
unsigned long cpuflags;
if (!tty->read_buf)
return;
if (tty->real_raw) {
spin_lock_irqsave(&tty->read_lock, cpuflags);
i = min(N_TTY_BUF_SIZE - tty->read_cnt,
N_TTY_BUF_SIZE - tty->read_head);
i = min(count, i);
memcpy(tty->read_buf + tty->read_head, cp, i);
tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
tty->read_cnt += i;
cp += i;
count -= i;
i = min(N_TTY_BUF_SIZE - tty->read_cnt,
N_TTY_BUF_SIZE - tty->read_head);
i = min(count, i);
memcpy(tty->read_buf + tty->read_head, cp, i);
tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
tty->read_cnt += i;
spin_unlock_irqrestore(&tty->read_lock, cpuflags);
} else {
for (i = count, p = cp, f = fp; i; i--, p++) {
if (f)
flags = *f++;
switch (flags) {
case TTY_NORMAL:
n_tty_receive_char(tty, *p);
break;
case TTY_BREAK:
n_tty_receive_break(tty);
break;
case TTY_PARITY:
case TTY_FRAME:
n_tty_receive_parity_error(tty, *p);
break;
case TTY_OVERRUN:
n_tty_receive_overrun(tty);
break;
default:
printk(KERN_ERR "%s: unknown flag %d\n",
tty_name(tty, buf), flags);
break;
}
}
if (tty->ops->flush_chars)
tty->ops->flush_chars(tty);
}
n_tty_set_room(tty);
if ((!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) ||
L_EXTPROC(tty)) {
kill_fasync(&tty->fasync, SIGIO, POLL_IN);
if (waitqueue_active(&tty->read_wait))
wake_up_interruptible(&tty->read_wait);
}
if (tty->receive_room < TTY_THRESHOLD_THROTTLE)
tty_throttle(tty);
}
static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
{
unsigned long flags;
int parmrk;
if (tty->raw) {
put_tty_queue(c, tty);
return;
}
if (I_ISTRIP(tty))
c &= 0x7f;
if (I_IUCLC(tty) && L_IEXTEN(tty))
c = tolower(c);
if (L_EXTPROC(tty)) {
put_tty_queue(c, tty);
return;
}
if (tty->stopped && !tty->flow_stopped && I_IXON(tty) &&
I_IXANY(tty) && c != START_CHAR(tty) && c != STOP_CHAR(tty) &&
c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) && c != SUSP_CHAR(tty)) {
start_tty(tty);
process_echoes(tty);
}
if (tty->closing) {
if (I_IXON(tty)) {
if (c == START_CHAR(tty)) {
start_tty(tty);
process_echoes(tty);
} else if (c == STOP_CHAR(tty))
stop_tty(tty);
}
return;
}
if (!test_bit(c, tty->process_char_map) || tty->lnext) {
tty->lnext = 0;
parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
if (L_ECHO(tty))
process_output('\a', tty);
return;
}
if (L_ECHO(tty)) {
finish_erasing(tty);
if (tty->canon_head == tty->read_head)
echo_set_canon_col(tty);
echo_char(c, tty);
process_echoes(tty);
}
if (parmrk)
put_tty_queue(c, tty);
put_tty_queue(c, tty);
return;
}
if (I_IXON(tty)) {
if (c == START_CHAR(tty)) {
start_tty(tty);
process_echoes(tty);
return;
}
if (c == STOP_CHAR(tty)) {
stop_tty(tty);
return;
}
}
if (L_ISIG(tty)) {
int signal;
signal = SIGINT;
if (c == INTR_CHAR(tty))
goto send_signal;
signal = SIGQUIT;
if (c == QUIT_CHAR(tty))
goto send_signal;
signal = SIGTSTP;
if (c == SUSP_CHAR(tty)) {
send_signal:
if (!L_NOFLSH(tty)) {
n_tty_flush_buffer(tty);
tty_driver_flush_buffer(tty);
}
if (I_IXON(tty))
start_tty(tty);
if (L_ECHO(tty)) {
echo_char(c, tty);
process_echoes(tty);
}
if (tty->pgrp)
kill_pgrp(tty->pgrp, signal, 1);
return;
}
}
if (c == '\r') {
if (I_IGNCR(tty))
return;
if (I_ICRNL(tty))
c = '\n';
} else if (c == '\n' && I_INLCR(tty))
c = '\r';
if (tty->icanon) {
if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
(c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
eraser(c, tty);
process_echoes(tty);
return;
}
if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) {
tty->lnext = 1;
if (L_ECHO(tty)) {
finish_erasing(tty);
if (L_ECHOCTL(tty)) {
echo_char_raw('^', tty);
echo_char_raw('\b', tty);
process_echoes(tty);
}
}
return;
}
if (c == REPRINT_CHAR(tty) && L_ECHO(tty) &&
L_IEXTEN(tty)) {
unsigned long tail = tty->canon_head;
finish_erasing(tty);
echo_char(c, tty);
echo_char_raw('\n', tty);
while (tail != tty->read_head) {
echo_char(tty->read_buf[tail], tty);
tail = (tail+1) & (N_TTY_BUF_SIZE-1);
}
process_echoes(tty);
return;
}
if (c == '\n') {
if (tty->read_cnt >= N_TTY_BUF_SIZE) {
if (L_ECHO(tty))
process_output('\a', tty);
return;
}
if (L_ECHO(tty) || L_ECHONL(tty)) {
echo_char_raw('\n', tty);
process_echoes(tty);
}
goto handle_newline;
}
if (c == EOF_CHAR(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE)
return;
if (tty->canon_head != tty->read_head)
set_bit(TTY_PUSH, &tty->flags);
c = __DISABLED_CHAR;
goto handle_newline;
}
if ((c == EOL_CHAR(tty)) ||
(c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty))
? 1 : 0;
if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk)) {
if (L_ECHO(tty))
process_output('\a', tty);
return;
}
if (L_ECHO(tty)) {
if (tty->canon_head == tty->read_head)
echo_set_canon_col(tty);
echo_char(c, tty);
process_echoes(tty);
}
if (parmrk)
put_tty_queue(c, tty);
handle_newline:
spin_lock_irqsave(&tty->read_lock, flags);
set_bit(tty->read_head, tty->read_flags);
put_tty_queue_nolock(c, tty);
tty->canon_head = tty->read_head;
tty->canon_data++;
spin_unlock_irqrestore(&tty->read_lock, flags);
kill_fasync(&tty->fasync, SIGIO, POLL_IN);
if (waitqueue_active(&tty->read_wait))
wake_up_interruptible(&tty->read_wait);
return;
}
}
parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
if (L_ECHO(tty))
process_output('\a', tty);
return;
}
if (L_ECHO(tty)) {
finish_erasing(tty);
if (c == '\n')
echo_char_raw('\n', tty);
else {
if (tty->canon_head == tty->read_head)
echo_set_canon_col(tty);
echo_char(c, tty);
}
process_echoes(tty);
}
if (parmrk)
put_tty_queue(c, tty);
put_tty_queue(c, tty);
}
static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
unsigned char __user *buf, size_t nr)
{
unsigned char __user *b = buf;
DECLARE_WAITQUEUE(wait, current);
int c;
int minimum, time;
ssize_t retval = 0;
ssize_t size;
long timeout;
unsigned long flags;
int packet;
do_it_again:
BUG_ON(!tty->read_buf);
c = job_control(tty, file);
if (c < 0)
return c;
minimum = time = 0;
timeout = MAX_SCHEDULE_TIMEOUT;
if (!tty->icanon) {
time = (HZ / 10) * TIME_CHAR(tty);
minimum = MIN_CHAR(tty);
if (minimum) {
if (time)
tty->minimum_to_wake = 1;
else if (!waitqueue_active(&tty->read_wait) ||
(tty->minimum_to_wake > minimum))
tty->minimum_to_wake = minimum;
} else {
timeout = 0;
if (time) {
timeout = time;
time = 0;
}
tty->minimum_to_wake = minimum = 1;
}
}
if (file->f_flags & O_NONBLOCK) {
if (!mutex_trylock(&tty->atomic_read_lock))
return -EAGAIN;
} else {
if (mutex_lock_interruptible(&tty->atomic_read_lock))
return -ERESTARTSYS;
}
packet = tty->packet;
add_wait_queue(&tty->read_wait, &wait);
while (nr) {
if (packet && tty->link->ctrl_status) {
unsigned char cs;
if (b != buf)
break;
spin_lock_irqsave(&tty->link->ctrl_lock, flags);
cs = tty->link->ctrl_status;
tty->link->ctrl_status = 0;
spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
if (tty_put_user(tty, cs, b++)) {
retval = -EFAULT;
b--;
break;
}
nr--;
break;
}
set_current_state(TASK_INTERRUPTIBLE);
if (((minimum - (b - buf)) < tty->minimum_to_wake) &&
((minimum - (b - buf)) >= 1))
tty->minimum_to_wake = (minimum - (b - buf));
if (!input_available_p(tty, 0)) {
if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
retval = -EIO;
break;
}
if (tty_hung_up_p(file))
break;
if (!timeout)
break;
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
n_tty_set_room(tty);
timeout = schedule_timeout(timeout);
BUG_ON(!tty->read_buf);
continue;
}
__set_current_state(TASK_RUNNING);
if (packet && b == buf) {
if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
retval = -EFAULT;
b--;
break;
}
nr--;
}
if (tty->icanon && !L_EXTPROC(tty)) {
while (nr && tty->read_cnt) {
int eol;
eol = test_and_clear_bit(tty->read_tail,
tty->read_flags);
c = tty->read_buf[tty->read_tail];
spin_lock_irqsave(&tty->read_lock, flags);
tty->read_tail = ((tty->read_tail+1) &
(N_TTY_BUF_SIZE-1));
tty->read_cnt--;
if (eol) {
if (--tty->canon_data < 0)
tty->canon_data = 0;
}
spin_unlock_irqrestore(&tty->read_lock, flags);
if (!eol || (c != __DISABLED_CHAR)) {
if (tty_put_user(tty, c, b++)) {
retval = -EFAULT;
b--;
break;
}
nr--;
}
if (eol) {
tty_audit_push(tty);
break;
}
}
if (retval)
break;
} else {
int uncopied;
uncopied = copy_from_read_buf(tty, &b, &nr);
uncopied += copy_from_read_buf(tty, &b, &nr);
if (uncopied) {
retval = -EFAULT;
break;
}
}
if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) {
n_tty_set_room(tty);
check_unthrottle(tty);
}
if (b - buf >= minimum)
break;
if (time)
timeout = time;
}
mutex_unlock(&tty->atomic_read_lock);
remove_wait_queue(&tty->read_wait, &wait);
if (!waitqueue_active(&tty->read_wait))
tty->minimum_to_wake = minimum;
__set_current_state(TASK_RUNNING);
size = b - buf;
if (size) {
retval = size;
if (nr)
clear_bit(TTY_PUSH, &tty->flags);
} else if (test_and_clear_bit(TTY_PUSH, &tty->flags))
goto do_it_again;
n_tty_set_room(tty);
return retval;
}