char: Remove unwanted crlf conversion

This patch fixes a bug in serial that made it almost impossible for guest
to communicate with devices through host's serial.

OPOST flag in c_oflag enables output processing letting other flags in
c_oflag take effect. Usually in c_oflag ONLCR flag is also set, which
causes crlf to be sent in place of lf. This breaks binary transmissions.
Unsetting OPOST flag turns off any output processing which fixes the bug.

Bug reports related:
https://bugs.launchpad.net/qemu/+bug/1772086
https://bugs.launchpad.net/qemu/+bug/1407813
https://bugs.launchpad.net/qemu/+bug/1715296
also
https://lists.nongnu.org/archive/html/qemu-devel/2006-06/msg00196.html

Signed-off-by: Patryk Olszewski <[email protected]>
Message-Id: <1527105041[email protected]>
Reviewed-by: Markus Armbruster <[email protected]>
Reviewed-by: Thomas Huth <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

diff --git a/chardev/char-serial.c b/chardev/char-serial.c
index feb52e559dacbf6c72a6d7b10f55d0bc91cf037c..ae548d28da954de983502bab0a8e441ae4163851 100644 (file)
--- a/chardev/char-serial.c
+++ b/chardev/char-serial.c
@@ -139,7 +139,7 @@ static void tty_serial_init(int fd, int speed,
 
     tty.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
                      | INLCR | IGNCR | ICRNL | IXON);
-    tty.c_oflag |= OPOST;
+    tty.c_oflag &= ~OPOST;
     tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN | ISIG);
     tty.c_cflag &= ~(CSIZE | PARENB | PARODD | CRTSCTS | CSTOPB);
     switch (data_bits) {

diff --git a/chardev/char-stdio.c b/chardev/char-stdio.c
index 96375f2ab886c87500d856027a791fa15c0d002d..d83e60e787b39b9b0dcc49838aa37165e0546c6f 100644 (file)
--- a/chardev/char-stdio.c
+++ b/chardev/char-stdio.c
@@ -59,7 +59,7 @@ static void qemu_chr_set_echo_stdio(Chardev *chr, bool echo)
     if (!echo) {
         tty.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
                          | INLCR | IGNCR | ICRNL | IXON);
-        tty.c_oflag |= OPOST;
+        tty.c_oflag &= ~OPOST;
         tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
         tty.c_cflag &= ~(CSIZE | PARENB);
         tty.c_cflag |= CS8;