Re: [PATCH 1/2 V2] kvm tools: Set up tun interface using ioctls

[Asias He <asias.hejun@gmail.com>]

On 04/14/2011 01:24 PM, Sasha Levin wrote:
> Use ioctls to assign IP address and bring interface up instead of using ifconfig.
> Not breaking aliasing rules this time.
> 
> Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
> ---
>  tools/kvm/virtio-net.c |   29 ++++++++++++++++++++++++++---
>  1 files changed, 26 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/kvm/virtio-net.c b/tools/kvm/virtio-net.c
> index ec70d5c..622cfc6 100644
> --- a/tools/kvm/virtio-net.c
> +++ b/tools/kvm/virtio-net.c
> @@ -14,6 +14,9 @@
>  #include <sys/ioctl.h>
>  #include <assert.h>
>  #include <fcntl.h>
> +#include <arpa/inet.h>
> +#include <sys/types.h>
> +#include <sys/socket.h>
>  
>  #define VIRTIO_NET_IRQ		14
>  #define VIRTIO_NET_QUEUE_SIZE	128
> @@ -276,7 +279,9 @@ static struct pci_device_header virtio_net_pci_device = {
>  static void virtio_net__tap_init(void)
>  {
>  	struct ifreq ifr;
> -
> +	int sock = socket(AF_INET, SOCK_STREAM, 0);
> +	struct sockaddr_in sin = {0};
> +
>  	net_device.tap_fd = open("/dev/net/tun", O_RDWR);
>  	if (net_device.tap_fd < 0)
>  		die("Unable to open /dev/net/tun\n");
> @@ -291,9 +296,27 @@ static void virtio_net__tap_init(void)
>  
>  	ioctl(net_device.tap_fd, TUNSETNOCSUM, 1);
>  
> +
> +	memset(&ifr, 0, sizeof(ifr));
> +
> +	strncpy(ifr.ifr_name, net_device.tap_name, sizeof(net_device.tap_name));
> +
>  	/*FIXME: Remove this after user can specify ip address and netmask*/
> -	if (system("ifconfig tap0 192.168.33.2") < 0)
> -		warning("Can not set ip address on tap0");
> +	sin.sin_addr.s_addr = inet_addr("192.168.33.2");
> +	memcpy(&(ifr.ifr_addr), &sin, sizeof(ifr.ifr_addr));
> +	ifr.ifr_addr.sa_family = AF_INET;
> +
> +	if (ioctl(sock, SIOCSIFADDR, &ifr) < 0)
> +		warning("Can not set ip address on tap device");
> +
> +	memset(&ifr, 0, sizeof(ifr));
> +	strncpy(ifr.ifr_name, net_device.tap_name, sizeof(net_device.tap_name));
> +	ioctl(sock, SIOCGIFFLAGS, &ifr);
> +	ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
> +	if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0)
> +		warning("Could not bring tap device up");
> +
> +	close(sock);
>  }
>  
>  static void virtio_net__io_thread_init(struct kvm *self)

Looks good to me.

Reviewed-by: Asias He <asias.hejun@gmail.com>

-- 
Best Regards,
Asias He