net/ipv6: Move gateway validation into helper
Move existing code to validate nexthop into a helper. Follow on patch
adds support for nexthops marked with onlink, and this helper keeps
the complexity of ip6_route_info_create in check.
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 aa4411c..bfd1a06 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2469,6 +2469,54 @@ static struct rt6_info *ip6_nh_lookup_table(struct net *net,
return rt;
}
+static int ip6_route_check_nh(struct net *net,
+ struct fib6_config *cfg,
+ struct net_device **_dev,
+ struct inet6_dev **idev)
+{
+ const struct in6_addr *gw_addr = &cfg->fc_gateway;
+ struct net_device *dev = _dev ? *_dev : NULL;
+ struct rt6_info *grt = NULL;
+ int err = -EHOSTUNREACH;
+
+ if (cfg->fc_table) {
+ grt = ip6_nh_lookup_table(net, cfg, gw_addr);
+ if (grt) {
+ if (grt->rt6i_flags & RTF_GATEWAY ||
+ (dev && dev != grt->dst.dev)) {
+ ip6_rt_put(grt);
+ grt = NULL;
+ }
+ }
+ }
+
+ if (!grt)
+ grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1);
+
+ if (!grt)
+ goto out;
+
+ if (dev) {
+ if (dev != grt->dst.dev) {
+ ip6_rt_put(grt);
+ goto out;
+ }
+ } else {
+ *_dev = dev = grt->dst.dev;
+ *idev = grt->rt6i_idev;
+ dev_hold(dev);
+ in6_dev_hold(grt->rt6i_idev);
+ }
+
+ if (!(grt->rt6i_flags & RTF_GATEWAY))
+ err = 0;
+
+ ip6_rt_put(grt);
+
+out:
+ return err;
+}
+
static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,
struct netlink_ext_ack *extack)
{
@@ -2664,8 +2712,6 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,
rt->rt6i_gateway = *gw_addr;
if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
- struct rt6_info *grt = NULL;
-
/* IPv6 strictly inhibits using not link-local
addresses as nexthop address.
Otherwise, router will not able to send redirects.
@@ -2682,40 +2728,7 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,
goto out;
}
- if (cfg->fc_table) {
- grt = ip6_nh_lookup_table(net, cfg, gw_addr);
-
- if (grt) {
- if (grt->rt6i_flags & RTF_GATEWAY ||
- (dev && dev != grt->dst.dev)) {
- ip6_rt_put(grt);
- grt = NULL;
- }
- }
- }
-
- if (!grt)
- grt = rt6_lookup(net, gw_addr, NULL,
- cfg->fc_ifindex, 1);
-
- err = -EHOSTUNREACH;
- if (!grt)
- goto out;
- if (dev) {
- if (dev != grt->dst.dev) {
- ip6_rt_put(grt);
- goto out;
- }
- } else {
- dev = grt->dst.dev;
- idev = grt->rt6i_idev;
- dev_hold(dev);
- in6_dev_hold(grt->rt6i_idev);
- }
- if (!(grt->rt6i_flags & RTF_GATEWAY))
- err = 0;
- ip6_rt_put(grt);
-
+ err = ip6_route_check_nh(net, cfg, &dev, &idev);
if (err)
goto out;
}