Commit 4bf1cb03 authored by Nils Carlson's avatar Nils Carlson Committed by Paolo Bonzini
Browse files

qemu-char: Fix missed data on unix socket 



Commit 812c1057 introduced HUP detection on unix and tcp sockets prior
to a read in tcp_chr_read. This unfortunately broke CloudStack 4.2
which relied on the old behaviour where data on a socket was readable
even if a HUP was present.

A working solution is to properly check the return values from recv,
handling a closed socket once there is no more data to read.

Also enable polling for G_IO_NVAL to ensure the callback is called
for all possible events as these should now be possible to handle
with the improved error detection.

Signed-off-by: default avatarNils Carlson <pyssling@ludd.ltu.se>
Message-Id: <1437338396-22336-1-git-send-email-pyssling@ludd.ltu.se>
[Do not handle EINTR; use socket_error(). - Paolo]
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 9172f428

qemu-char.c

+5 −8
Original line number Diff line number Diff line
@@ -807,7 +807,8 @@ static gboolean io_watch_poll_prepare(GSource *source, gint *timeout_) 
    }



    if (now_active) {

        iwp->src = g_io_create_watch(iwp->channel, G_IO_IN | G_IO_ERR | G_IO_HUP);

        iwp->src = g_io_create_watch(iwp->channel,

                                     G_IO_IN | G_IO_ERR | G_IO_HUP | G_IO_NVAL);

        g_source_set_callback(iwp->src, iwp->fd_read, iwp->opaque, NULL);

        g_source_attach(iwp->src, NULL);

    } else {
@@ -2856,12 +2857,6 @@ 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) {

        /* connection closed */

        tcp_chr_disconnect(chr);

        return TRUE;

    }



    if (!s->connected || s->max_size <= 0) {

        return TRUE;

    }
@@ -2869,7 +2864,9 @@ static gboolean tcp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque) 
    if (len > s->max_size)

        len = s->max_size;

    size = tcp_chr_recv(chr, (void *)buf, len);

    if (size == 0) {

    if (size == 0 ||

        (size < 0 &&

         socket_error() != EAGAIN && socket_error() != EWOULDBLOCK)) {

        /* connection closed */

        tcp_chr_disconnect(chr);

    } else if (size > 0) {