Re: [Qemu-devel] [PATCH v4 4/4] Add support for net bridge

[Mark Wu <wudxw@linux.vnet.ibm.com>]

On 11/02/2011 01:13 AM, Corey Bryant wrote:
>   static int net_tap_init(QemuOpts *opts, int *vnet_hdr)
>   {
>       int fd, vnet_hdr_required;
> @@ -433,8 +570,11 @@ int net_init_tap(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan
>           if (qemu_opt_get(opts, "ifname") ||
>               qemu_opt_get(opts, "script") ||
>               qemu_opt_get(opts, "downscript") ||
> -            qemu_opt_get(opts, "vnet_hdr")) {
> -            error_report("ifname=, script=, downscript= and vnet_hdr= is invalid with fd=");
> +            qemu_opt_get(opts, "vnet_hdr") ||
> +            qemu_opt_get(opts, "br") ||
> +            qemu_opt_get(opts, "helper")) {
> +            error_report("ifname=, script=, downscript=, vnet_hdr=,"
> +                         "br= and helper= are invalid with fd=");
>               return -1;
>           }
If
> @@ -446,7 +586,40 @@ int net_init_tap(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan
>           fcntl(fd, F_SETFL, O_NONBLOCK);
>
>           vnet_hdr = tap_probe_vnet_hdr(fd);
> +    } else if (qemu_opt_get(opts, "helper")) {
> +        if (qemu_opt_get(opts, "ifname") ||
> +            qemu_opt_get(opts, "script") ||
> +            qemu_opt_get(opts, "downscript")) {
> +            error_report("ifname=, script= and downscript="
> +                         "are invalid with helper=");
> +            return -1;
> +        }
> +
> +        if (!qemu_opt_get(opts, "br")) {
> +            qemu_opt_set(opts, "br", DEFAULT_BRIDGE_INTERFACE);
> +        }
> +
> +        fd = net_bridge_run_helper(qemu_opt_get(opts, "helper"),
> +                                   qemu_opt_get(opts, "br"));
> +        if (fd == -1) {
> +            return -1;
> +        }
> +
> +        fcntl(fd, F_SETFL, O_NONBLOCK);
> +
> +        vnet_hdr = tap_probe_vnet_hdr(fd);
> +
> +        s = net_tap_fd_init(vlan, "bridge", name, fd, vnet_hdr);
>
The helper run with "--use-vnet"  by default, so the option "vnet_hdr" 
will not be honored. We can make "vnet_hdr" invalid with "br" or check 
the option "vnet_hdr" in function net_bridge_run_helper.