Re: [PATCH 2.4] SIOCSIFNAME wildcard support (resend)

[Marcelo Tosatti <marcelo.tosatti@cyclades.com>]

Hi Jean,

On Tue, Feb 08, 2005 at 10:14:36AM -0800, Jean Tourrilhes wrote:
> 	Hi Marcelo,
> 
> 	I did not receive any feedback on this e-mail, so I assume it
> was lost on the way. Would you mind pushing that in 2.4.x ?
> 	Thanks...

As an ignorant person I have no problems with it.

David, what is your opinion?

> 	Jean
> 
> ----- Forwarded message from jt -----
> 
> Subject: [PATCH 2.4] SIOCSIFNAME wildcard support
> E-mail: jt@hpl.hp.com
> 
> 	Hi Marcelo,
> 
> 	This patch adds wildcard support for the SIOCSIFNAME ioctl,
> like what was done in 2.6.1. SIOCSIFNAME allow a user space tool to
> change network interface names (such as nameif, ifrename, or ip link),
> this patch allow those tools to specify a pattern, such as "eth%d" or
> "wlan%d", and the kernel use the lowest available slot.
> 	The reason I'm sending you this patch is that I've got some
> 2.4.X users who requested the feature...
> 	This patch was initially done for 2.4.23, and I rediffed and
> retested with 2.4.29. It's somewhat different from the patch Stephen
> and me added to 2.6.1, because the netdev init code is different and
> also this patch is more conservative.
> 
> 	Have fun...
> 
> 	Jean
> 
> -------------------------------------------------------------
> 
> diff -u -p linux/net/core/dev.j1.c linux/net/core/dev.c
> --- linux/net/core/dev.j1.c	Wed Dec  3 14:29:21 2003
> +++ linux/net/core/dev.c	Wed Dec  3 18:55:27 2003
> @@ -2179,10 +2179,26 @@ static int dev_ifsioc(struct ifreq *ifr,
>  		case SIOCSIFNAME:
>  			if (dev->flags&IFF_UP)
>  				return -EBUSY;
> -			if (__dev_get_by_name(ifr->ifr_newname))
> -				return -EEXIST;
> -			memcpy(dev->name, ifr->ifr_newname, IFNAMSIZ);
> -			dev->name[IFNAMSIZ-1] = 0;
> +			/* Check if name contains a wildcard */
> +			if (strchr(ifr->ifr_newname, '%')) {
> +				char format[IFNAMSIZ + 1];
> +				int ret;
> +				memcpy(format, ifr->ifr_newname, IFNAMSIZ);
> +				format[IFNAMSIZ-1] = 0;
> +				/* Find a free name based on format.
> +				 * dev_alloc_name() replaces "%d" with at max
> +				 * 2 digits, so no name overflow. - Jean II */
> +				ret = dev_alloc_name(dev, format);
> +				if (ret < 0)
> +					return ret;
> +				/* Copy the new name back to caller. */
> +				strncpy(ifr->ifr_newname, dev->name, IFNAMSIZ);
> +			} else {
> +				if (__dev_get_by_name(ifr->ifr_newname))
> +					return -EEXIST;
> +				memcpy(dev->name, ifr->ifr_newname, IFNAMSIZ);
> +				dev->name[IFNAMSIZ-1] = 0;
> +			}
>  			notifier_call_chain(&netdev_chain, NETDEV_CHANGENAME, dev);
>  			return 0;
>  
> @@ -2315,6 +2331,7 @@ int dev_ioctl(unsigned int cmd, void *ar
>  		 *	- return a value
>  		 */
>  		 
> +		case SIOCSIFNAME:
>  		case SIOCGMIIPHY:
>  		case SIOCGMIIREG:
>  			if (!capable(CAP_NET_ADMIN))
> @@ -2350,7 +2367,6 @@ int dev_ioctl(unsigned int cmd, void *ar
>  		case SIOCDELMULTI:
>  		case SIOCSIFHWBROADCAST:
>  		case SIOCSIFTXQLEN:
> -		case SIOCSIFNAME:
>  		case SIOCSMIIREG:
>  		case SIOCBONDENSLAVE:
>  		case SIOCBONDRELEASE:
> -