PERFORCE change 128041 for review

[Julian Elischer]

Marko Zec wrote:
> http://perforce.freebsd.org/chv.cgi?CH=128041
> 
> Change 128041 by zec at zec_tpx32 on 2007/10/25 00:15:01
> 
> 	A hack to allow for bpf taps to be open directly on ifnets
> 	attached to foreign vnets.
> 	
> 	ifname at vimage_name is the form that should be used for
> 	tcpdump or ethereal to attach directly to an ifnet in
> 	a foerign vnet.
> 

by definition it would have to be a child vnet right?

> Affected files ...
> 
> .. //depot/projects/vimage/src/sys/net/bpf.c#15 edit
> 
> Differences ...
> 
> ==== //depot/projects/vimage/src/sys/net/bpf.c#15 (text+ko) ====
> 
> @@ -1156,9 +1156,32 @@
>  	struct bpf_if *bp;
>  	struct ifnet *theywant;
>  
> +#define IMUNES_BPF_HACK
> +#if defined(VIMAGE) && defined(IMUNES_BPF_HACK)
> +	struct vnet *target_vnet = curvnet;
> +	char *c;
> +
> +	/* Hack to support tapping in foreign vnets */
> +	c = rindex(ifr->ifr_name, '@');
> +	if ( c != NULL ) {
> +		struct vimage *target_vimage;
> +
> +		*c++ = 0;
> +		target_vimage = vimage_by_name(TD_TO_VIMAGE(curthread), c);
> +		if (target_vimage == NULL)
> +			return ENXIO;
> +		target_vnet = target_vimage->v_net;
> +        }
> +	CURVNET_SET_QUIET(target_vnet);
> +#endif
> +
>  	theywant = ifunit(ifr->ifr_name);
> -	if (theywant == NULL || theywant->if_bpf == NULL)
> +	if (theywant == NULL || theywant->if_bpf == NULL) {
> +#if defined(VIMAGE) && defined(IMUNES_BPF_HACK)
> +		CURVNET_RESTORE();
> +#endif
>  		return (ENXIO);
> +	}
>  
>  	bp = theywant->if_bpf;
>  	/*
> @@ -1180,6 +1203,9 @@
>  	BPFD_LOCK(d);
>  	reset_d(d);
>  	BPFD_UNLOCK(d);
> +#if defined(VIMAGE) && defined(IMUNES_BPF_HACK)
> +	CURVNET_RESTORE();
> +#endif
>  	return (0);
>  }
>