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: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 222af19..3b301aa 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -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 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
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 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
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) {