Commit 6edb3c96 authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

net/ipv6: Defer initialization of dst to data path 



Defer setting dst input, output and error until fib entry is copied.

The reject path from ip6_route_info_create is moved to a new function
ip6_rt_init_dst_reject with a helper doing the conversion from fib6_type
to dst error.

The remainder of the new ip6_rt_init_dst is an amalgamtion of dst code
from addrconf_dst_alloc and the non-reject path of ip6_route_info_create.
The dst output function is always ip6_output and the input function is
either ip6_input (local routes), ip6_mc_input (multicast routes) or
ip6_forward (anything else).

A couple of places using dst.error are updated to look at rt6i_flags.

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5e670d84

net/ipv6/route.c

+74 −41
Original line number Diff line number Diff line
@@ -920,6 +920,75 @@ static struct net_device *ip6_rt_get_dev_rcu(struct rt6_info *rt) 
	return dev;

}



static const int fib6_prop[RTN_MAX + 1] = {

	[RTN_UNSPEC]	= 0,

	[RTN_UNICAST]	= 0,

	[RTN_LOCAL]	= 0,

	[RTN_BROADCAST]	= 0,

	[RTN_ANYCAST]	= 0,

	[RTN_MULTICAST]	= 0,

	[RTN_BLACKHOLE]	= -EINVAL,

	[RTN_UNREACHABLE] = -EHOSTUNREACH,

	[RTN_PROHIBIT]	= -EACCES,

	[RTN_THROW]	= -EAGAIN,

	[RTN_NAT]	= -EINVAL,

	[RTN_XRESOLVE]	= -EINVAL,

};



static int ip6_rt_type_to_error(u8 fib6_type)

{

	return fib6_prop[fib6_type];

}



static void ip6_rt_init_dst_reject(struct rt6_info *rt, struct rt6_info *ort)

{

	rt->dst.error = ip6_rt_type_to_error(ort->fib6_type);



	switch (ort->fib6_type) {

	case RTN_BLACKHOLE:

		rt->dst.output = dst_discard_out;

		rt->dst.input = dst_discard;

		break;

	case RTN_PROHIBIT:

		rt->dst.output = ip6_pkt_prohibit_out;

		rt->dst.input = ip6_pkt_prohibit;

		break;

	case RTN_THROW:

	case RTN_UNREACHABLE:

	default:

		rt->dst.output = ip6_pkt_discard_out;

		rt->dst.input = ip6_pkt_discard;

		break;

	}

}



static void ip6_rt_init_dst(struct rt6_info *rt, struct rt6_info *ort)

{

	if (ort->rt6i_flags & RTF_REJECT) {

		ip6_rt_init_dst_reject(rt, ort);

		return;

	}



	rt->dst.error = 0;

	rt->dst.output = ip6_output;



	if (ort->fib6_type == RTN_LOCAL) {

		rt->dst.flags |= DST_HOST;

		rt->dst.input = ip6_input;

	} else if (ipv6_addr_type(&ort->rt6i_dst.addr) & IPV6_ADDR_MULTICAST) {

		rt->dst.input = ip6_mc_input;

	} else {

		rt->dst.input = ip6_forward;

	}



	if (ort->fib6_nh.nh_lwtstate) {

		rt->dst.lwtstate = lwtstate_get(ort->fib6_nh.nh_lwtstate);

		lwtunnel_set_redirect(&rt->dst);

	}



	rt->dst.lastuse = jiffies;

}



static void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)

{

	BUG_ON(from->from);
@@ -932,14 +1001,12 @@ static void rt6_set_from(struct rt6_info *rt, struct rt6_info *from) 


static void ip6_rt_copy_init(struct rt6_info *rt, struct rt6_info *ort)

{

	rt->dst.input = ort->dst.input;

	rt->dst.output = ort->dst.output;

	ip6_rt_init_dst(rt, ort);



	rt->rt6i_dst = ort->rt6i_dst;

	rt->dst.error = ort->dst.error;

	rt->rt6i_idev = ort->rt6i_idev;

	if (rt->rt6i_idev)

		in6_dev_hold(rt->rt6i_idev);

	rt->dst.lastuse = jiffies;

	rt->rt6i_gateway = ort->fib6_nh.nh_gw;

	rt->rt6i_flags = ort->rt6i_flags;

	rt6_set_from(rt, ort);
@@ -2329,7 +2396,7 @@ restart: 
			continue;

		if (rt6_check_expired(rt))

			continue;

		if (rt->dst.error)

		if (rt->rt6i_flags & RTF_REJECT)

			break;

		if (!(rt->rt6i_flags & RTF_GATEWAY))

			continue;
@@ -2357,7 +2424,7 @@ restart: 


	if (!rt)

		rt = net->ipv6.ip6_null_entry;

	else if (rt->dst.error) {

	else if (rt->rt6i_flags & RTF_REJECT) {

		rt = net->ipv6.ip6_null_entry;

		goto out;

	}
@@ -2900,15 +2967,6 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg, 


	addr_type = ipv6_addr_type(&cfg->fc_dst);



	if (addr_type & IPV6_ADDR_MULTICAST)

		rt->dst.input = ip6_mc_input;

	else if (cfg->fc_flags & RTF_LOCAL)

		rt->dst.input = ip6_input;

	else

		rt->dst.input = ip6_forward;



	rt->dst.output = ip6_output;



	if (cfg->fc_encap) {

		struct lwtunnel_state *lwtstate;
@@ -2918,7 +2976,6 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg, 
		if (err)

			goto out;

		rt->fib6_nh.nh_lwtstate = lwtstate_get(lwtstate);

		lwtunnel_set_redirect(&rt->dst);

	}



	ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
@@ -2958,27 +3015,6 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg, 
			}

		}

		rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP;

		switch (cfg->fc_type) {

		case RTN_BLACKHOLE:

			rt->dst.error = -EINVAL;

			rt->dst.output = dst_discard_out;

			rt->dst.input = dst_discard;

			break;

		case RTN_PROHIBIT:

			rt->dst.error = -EACCES;

			rt->dst.output = ip6_pkt_prohibit_out;

			rt->dst.input = ip6_pkt_prohibit;

			break;

		case RTN_THROW:

		case RTN_UNREACHABLE:

		default:

			rt->dst.error = (cfg->fc_type == RTN_THROW) ? -EAGAIN

					: (cfg->fc_type == RTN_UNREACHABLE)

					? -EHOSTUNREACH : -ENETUNREACH;

			rt->dst.output = ip6_pkt_discard_out;

			rt->dst.input = ip6_pkt_discard;

			break;

		}

		goto install_route;

	}
@@ -3623,12 +3659,9 @@ struct rt6_info *addrconf_dst_alloc(struct net *net, 
		return ERR_PTR(-ENOMEM);



	in6_dev_hold(idev);



	rt->dst.flags |= DST_HOST;

	rt->dst.input = ip6_input;

	rt->dst.output = ip6_output;

	rt->rt6i_idev = idev;



	rt->dst.flags |= DST_HOST;

	rt->rt6i_protocol = RTPROT_KERNEL;

	rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP;

	if (anycast) {

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