Hi On Mon, Mar 18, 2024 at 10:23 PM Daniel P. Berrangé <[email protected]> wrote: > > 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 1907f4d149c3589ade641423c6a33fd7598fa4d3.
Actually 462945cd22d2bcd233401ed3aa167d83a8e35b05 upstream. > > Signed-off-by: Daniel P. Berrangé <[email protected]> > --- > chardev/char-socket.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/chardev/char-socket.c b/chardev/char-socket.c > index 2c4dffc0e6..812d7aa38a 100644 > --- a/chardev/char-socket.c > +++ b/chardev/char-socket.c > @@ -496,9 +496,9 @@ static gboolean tcp_chr_read(QIOChannel *chan, > GIOCondition cond, void *opaque) > 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)) { > -- > 2.43.0 >
