Revert "chardev/char-socket: Fix TLS io channels sending too much data to the backend"
This commit results in unexpected termination of the TLS connection.
When 'fd_can_read' returns 0, the code goes on to pass a zero length
buffer to qio_channel_read. The TLS impl calls into gnutls_recv()
with this zero length buffer, at which point GNUTLS returns an error
GNUTLS_E_INVALID_REQUEST. This is treated as fatal by QEMU's TLS code
resulting in the connection being torn down by the chardev.
Simply skipping the qio_channel_read when the buffer length is zero
is also not satisfactory, as it results in a high CPU burn busy loop
massively slowing QEMU's functionality.
The proper solution is to avoid tcp_chr_read being called at all
unless the frontend is able to accept more data. This will be done
in a followup commit.
This reverts commit 462945cd22d2bcd233401ed3aa167d83a8e35b05
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
diff --git a/chardev/char-socket.c b/chardev/char-socket.c
index 2c4dffc..812d7aa 100644
--- a/chardev/char-socket.c
+++ b/chardev/char-socket.c
@@ -496,9 +496,9 @@
s->max_size <= 0) {
return TRUE;
}
- len = tcp_chr_read_poll(opaque);
- if (len > sizeof(buf)) {
- len = sizeof(buf);
+ len = sizeof(buf);
+ if (len > s->max_size) {
+ len = s->max_size;
}
size = tcp_chr_recv(chr, (void *)buf, len);
if (size == 0 || (size == -1 && errno != EAGAIN)) {
