Re: [PATCH 13/13] [RFC] [IPV6] Fix source prefix routing problems when source address undefined.

[Thomas Graf <tgraf@suug.ch>]

* Ville Nuorvala <vnuorval@tcs.hut.fi> 2006-10-17 03:27
> @@ -123,7 +111,7 @@ static int fib6_rule_match(struct fib_ru
>  		return 0;
> 
>  	if (r->src.plen) {
> -		if (!(flags & RT6_LOOKUP_F_HAS_SADDR) ||
> +		if (flags & RT6_LOOKUP_F_HAS_SADDR &&
>  		    !ipv6_prefix_equal(&fl->fl6_src, &r->src.addr, r->src.plen))
>  			return 0;
>  	}

This is wrong, rules matching on a source prefix must fail if no
source address is available.

>  static struct rt6_info *ip6_pol_route_output(struct fib6_table *table,
> -					     struct flowi *fl, int flags)
> +					     struct flowi *fl, int flags,
> +					     struct fib6_rule *rule)
>  {
>  	struct fib6_node *fn;
>  	struct rt6_info *rt, *nrt;
> @@ -730,6 +733,16 @@ static struct rt6_info *ip6_pol_route_ou
>  	struct in6_addr saddr;
> 
>  	ipv6_addr_copy(&saddr, &fl->fl6_src);
> +#ifdef CONFIG_IPV6_SUBTREES
> +	if (!has_saddr && rule->src.plen > 0) {
> +		/* a source prefix specific policy rule has to override the
> +		   normal source address selection process */
> +		if (ipv6_get_saddr(fl->oif, &fl->fl6_dst, &rule->src, &saddr))
> +			goto no_saddr;
> +		has_saddr = RT6_LOOKUP_F_HAS_SADDR;
> +		ipv6_addr_copy(&fl->fl6_src, &saddr);
> +	}
> +#endif
>  relookup:
>  	read_lock_bh(&table->tb6_lock);

I can see why you want the above change but we have to find another way.