[Qemu-devel] [PATCH] qemu-char: Do not disconnect when there's data for reading

[Zifei Tong <zifeitong@gmail.com>]

After commit 812c1057f6175ac9a9829fa2920a2b5783814193 (Handle G_IO_HUP
in tcp_chr_read for tcp chardev), the connection is disconnected when in
G_IO_HUP condition.

However, it's possible that the channel is in G_IO_IN condition at the
same time, meaning there is data for reading. In that case, the
remaining data is not handled.

I saw a related bug when running socat in write-only mode, with

  $ echo "quit" | socat -u - UNIX-CONNECT:qemu-monitor

the monitor won't not run the 'quit' command.

CC: Kirill Batuzov <batuzovk@ispras.ru>
CC: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
CC: Anthony Liguori <aliguori@amazon.com>
Signed-off-by: Zifei Tong <zifeitong@gmail.com>
---
 qemu-char.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/qemu-char.c b/qemu-char.c
index 1a8d9aa..5018c3a 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2706,7 +2706,7 @@ static gboolean tcp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque)
     uint8_t buf[READ_BUF_LEN];
     int len, size;
 
-    if (cond & G_IO_HUP) {
+    if (!(cond & G_IO_IN) && (cond & G_IO_HUP)) {
         /* connection closed */
         tcp_chr_disconnect(chr);
         return TRUE;
-- 
2.1.0