tty: n_tty: move canon handling to a separate function

n_tty_receive_char_special() is already complicated enough. Split the
canon handling to a separate function: n_tty_receive_char_canon().

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230827074147.2287-8-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 07b6a01..0149dc9 100644 (file)
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1262,6 +1262,91 @@ static bool n_tty_receive_char_flow_ctrl(struct tty_struct *tty, unsigned char c
        return true;
 }
 
+static bool n_tty_receive_char_canon(struct tty_struct *tty, u8 c)
+{
+       struct n_tty_data *ldata = tty->disc_data;
+
+       if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
+           (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
+               eraser(c, tty);
+               commit_echoes(tty);
+
+               return true;
+       }
+
+       if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) {
+               ldata->lnext = 1;
+               if (L_ECHO(tty)) {
+                       finish_erasing(ldata);
+                       if (L_ECHOCTL(tty)) {
+                               echo_char_raw('^', ldata);
+                               echo_char_raw('\b', ldata);
+                               commit_echoes(tty);
+                       }
+               }
+
+               return true;
+       }
+
+       if (c == REPRINT_CHAR(tty) && L_ECHO(tty) && L_IEXTEN(tty)) {
+               size_t tail = ldata->canon_head;
+
+               finish_erasing(ldata);
+               echo_char(c, tty);
+               echo_char_raw('\n', ldata);
+               while (MASK(tail) != MASK(ldata->read_head)) {
+                       echo_char(read_buf(ldata, tail), tty);
+                       tail++;
+               }
+               commit_echoes(tty);
+
+               return true;
+       }
+
+       if (c == '\n') {
+               if (L_ECHO(tty) || L_ECHONL(tty)) {
+                       echo_char_raw('\n', ldata);
+                       commit_echoes(tty);
+               }
+               goto handle_newline;
+       }
+
+       if (c == EOF_CHAR(tty)) {
+               c = __DISABLED_CHAR;
+               goto handle_newline;
+       }
+
+       if ((c == EOL_CHAR(tty)) ||
+           (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
+               /*
+                * XXX are EOL_CHAR and EOL2_CHAR echoed?!?
+                */
+               if (L_ECHO(tty)) {
+                       /* Record the column of first canon char. */
+                       if (ldata->canon_head == ldata->read_head)
+                               echo_set_canon_col(ldata);
+                       echo_char(c, tty);
+                       commit_echoes(tty);
+               }
+               /*
+                * XXX does PARMRK doubling happen for
+                * EOL_CHAR and EOL2_CHAR?
+                */
+               if (c == (unsigned char) '\377' && I_PARMRK(tty))
+                       put_tty_queue(c, ldata);
+
+handle_newline:
+               set_bit(MASK(ldata->read_head), ldata->read_flags);
+               put_tty_queue(c, ldata);
+               smp_store_release(&ldata->canon_head, ldata->read_head);
+               kill_fasync(&tty->fasync, SIGIO, POLL_IN);
+               wake_up_interruptible_poll(&tty->read_wait, EPOLLIN | EPOLLRDNORM);
+               return true;
+       }
+
+       return false;
+}
+
 static void n_tty_receive_char_special(struct tty_struct *tty, unsigned char c,
                                       bool lookahead_done)
 {
@@ -1296,77 +1381,8 @@ static void n_tty_receive_char_special(struct tty_struct *tty, unsigned char c,
        } else if (c == '\n' && I_INLCR(tty))
                c = '\r';
 
-       if (ldata->icanon) {
-               if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
-                   (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
-                       eraser(c, tty);
-                       commit_echoes(tty);
-                       return;
-               }
-               if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) {
-                       ldata->lnext = 1;
-                       if (L_ECHO(tty)) {
-                               finish_erasing(ldata);
-                               if (L_ECHOCTL(tty)) {
-                                       echo_char_raw('^', ldata);
-                                       echo_char_raw('\b', ldata);
-                                       commit_echoes(tty);
-                               }
-                       }
-                       return;
-               }
-               if (c == REPRINT_CHAR(tty) && L_ECHO(tty) && L_IEXTEN(tty)) {
-                       size_t tail = ldata->canon_head;
-
-                       finish_erasing(ldata);
-                       echo_char(c, tty);
-                       echo_char_raw('\n', ldata);
-                       while (MASK(tail) != MASK(ldata->read_head)) {
-                               echo_char(read_buf(ldata, tail), tty);
-                               tail++;
-                       }
-                       commit_echoes(tty);
-                       return;
-               }
-               if (c == '\n') {
-                       if (L_ECHO(tty) || L_ECHONL(tty)) {
-                               echo_char_raw('\n', ldata);
-                               commit_echoes(tty);
-                       }
-                       goto handle_newline;
-               }
-               if (c == EOF_CHAR(tty)) {
-                       c = __DISABLED_CHAR;
-                       goto handle_newline;
-               }
-               if ((c == EOL_CHAR(tty)) ||
-                   (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
-                       /*
-                        * XXX are EOL_CHAR and EOL2_CHAR echoed?!?
-                        */
-                       if (L_ECHO(tty)) {
-                               /* Record the column of first canon char. */
-                               if (ldata->canon_head == ldata->read_head)
-                                       echo_set_canon_col(ldata);
-                               echo_char(c, tty);
-                               commit_echoes(tty);
-                       }
-                       /*
-                        * XXX does PARMRK doubling happen for
-                        * EOL_CHAR and EOL2_CHAR?
-                        */
-                       if (c == (unsigned char) '\377' && I_PARMRK(tty))
-                               put_tty_queue(c, ldata);
-
-handle_newline:
-                       set_bit(MASK(ldata->read_head), ldata->read_flags);
-                       put_tty_queue(c, ldata);
-                       smp_store_release(&ldata->canon_head, ldata->read_head);
-                       kill_fasync(&tty->fasync, SIGIO, POLL_IN);
-                       wake_up_interruptible_poll(&tty->read_wait, EPOLLIN | EPOLLRDNORM);
-                       return;
-               }
-       }
+       if (ldata->icanon && n_tty_receive_char_canon(tty, c))
+               return;
 
        if (L_ECHO(tty)) {
                finish_erasing(ldata);