Re: [PATCH V2 5/6] runqemu: fixes for slirp, network device and hostfwd

[Randy Witt <randy.e.witt@linux.intel.com>]

>      def setup_slirp(self):
>          """Setup user networking"""
>
>          if self.fstype == 'nfs':
>              self.setup_nfs()
>          self.kernel_cmdline_script += ' ip=dhcp'
> -        self.set('NETWORK_CMD', self.get('QB_SLIRP_OPT'))
> +        # Port mapping
> +        hostfwd = ",hostfwd=tcp::2222-:22,hostfwd=tcp::2323-:23"
> +        qb_slirp_opt_default = "-netdev user,id=net0%s" % hostfwd
> +        qb_slirp_opt = self.get('QB_SLIRP_OPT') or qb_slirp_opt_default
> +        # Figure out the port
> +        ports = re.findall('hostfwd=[^-]*:([0-9]+)-[^,-]*', qb_slirp_opt)
> +        ports = [int(i) for i in ports]
> +        mac = 2
> +        # Find a free port to avoid conflicts
> +        for p in ports[:]:
> +            p_new = p
> +            while not check_free_port('localhost', p_new):
> +                p_new += 1
> +                mac += 1
> +                while p_new in ports:
> +                        p_new += 1
> +                        mac += 1
> +            if p != p_new:
> +                ports.append(p_new)
> +                qb_slirp_opt = re.sub(':%s-' % p, ':%s-' % p_new, qb_slirp_opt)
> +                logger.info("Port forward changed: %s -> %s" % (p, p_new))
Regardless if the port is changed or not, so that things like tests have an 
easier time of figuring out the port mappings, would it be good add a flag that 
prints out the entire list of ports used, or always do it? i.e. "Port forwarding 
2222:22 2333:23.... It's not necessary of course, you can  always look at the 
command line and then check to see if anything is remapped. But that's a bit 
more work.

> +        mac = "%s%02x" % (self.mac_slirp, mac)
> +        self.set('NETWORK_CMD', '%s %s' % (self.network_device.replace('@MAC@', mac), qb_slirp_opt))