Re: [Qemu-devel] [PATCH v6 3/4] net/net: Convert parse_host_port() to Error

["Daniel P. Berrange" <berrange@redhat.com>]

On Wed, Jun 28, 2017 at 09:24:58AM -0500, Eric Blake wrote:
> On 06/28/2017 08:23 AM, Daniel P. Berrange wrote:
> > On Wed, Jun 28, 2017 at 09:08:49PM +0800, Mao Zhongyi wrote:
> >> diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h
> >> index 5c326db..78e2b30 100644
> >> --- a/include/qemu/sockets.h
> >> +++ b/include/qemu/sockets.h
> > 
> >>          if (qemu_isdigit(buf[0])) {
> >> -            if (!inet_aton(buf, &saddr->sin_addr))
> >> +            if (!inet_aton(buf, &saddr->sin_addr)) {
> >> +                error_setg(errp, "host address '%s' is not a valid "
> >> +                           "IPv4 address", buf);
> >>                  return -1;
> >> +            }
> >>          } else {
> >> -            if ((he = gethostbyname(buf)) == NULL)
> >> +            he = gethostbyname(buf);
> >> +            if (he == NULL) {
> >> +                error_setg(errp, "can't resolve host address '%s': "
> >> +                           "unknown host", buf);
> >>                  return - 1;
> >> +            }
> > 
> > gethostbyname sets  'h_errno' on failure, so you should pass that
> > into error_setg_errno, instead of hardcoding 'unknown host' as a
> > message
> 
> 'man gethostbyname' says it is deprecated, and that applications should
> use getaddrinfo/getnameinfo instead.  What's our story here?

The real story is to get net/socket.c converted to QIOChannelSocket
and kill this parse_host_port() method in sockets.c It is already
broken by design since it takes a 'struct sockdddr_in' and thus
can't do IPv6.

This patch doesn't make the existing situation worse, so I think
its fine to add this error reporting cleanup now, and not force
immediate conversion to QIOChannelSocket today.  The net/sockets.c
code needs a further refactor before that conversion can be done
in the right way - we've already reverted the wrong way twice ;-)

Regards,
Daniel
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