Merge branch 'ipv6-Use-fib6_result-for-fib_lookups'

David Ahern says:

====================
ipv6: Use fib6_result for fib_lookups

Add fib6_result as a single data structure to hold results from a fib
lookup. IPv6 currently has everything in 1 data structure - a fib6_info,
but with nexthop objects the fib6_nh can be in a nexthop or a nexthop
can be a blackhole which affects the fib6_type and flags (REJECT).

v2
- fixed 2 bugs in patch12:
  i. checking return from fib6_table_lookup in fib6_lookup
  ii. call to fib6_rule_saddr in fib6_rule_action_alt should use res->nh
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 29 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index 07687e2a2e66..1644a16afcec 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4679,12 +4679,12 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
 	struct in6_addr *src = (struct in6_addr *) params->ipv6_src;
 	struct in6_addr *dst = (struct in6_addr *) params->ipv6_dst;
 	struct neighbour *neigh;
+	struct fib6_result res;
 	struct net_device *dev;
 	struct inet6_dev *idev;
-	struct fib6_info *f6i;
 	struct flowi6 fl6;
 	int strict = 0;
-	int oif;
+	int oif, err;
 	u32 mtu;
 
 	/* link local addresses are never forwarded */
@@ -4726,54 +4726,52 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
 		if (unlikely(!tb))
 			return BPF_FIB_LKUP_RET_NOT_FWDED;
 
-		f6i = ipv6_stub->fib6_table_lookup(net, tb, oif, &fl6, strict);
+		err = ipv6_stub->fib6_table_lookup(net, tb, oif, &fl6, &res,
+						   strict);
 	} else {
 		fl6.flowi6_mark = 0;
 		fl6.flowi6_secid = 0;
 		fl6.flowi6_tun_key.tun_id = 0;
 		fl6.flowi6_uid = sock_net_uid(net, NULL);
 
-		f6i = ipv6_stub->fib6_lookup(net, oif, &fl6, strict);
+		err = ipv6_stub->fib6_lookup(net, oif, &fl6, &res, strict);
 	}
 
-	if (unlikely(IS_ERR_OR_NULL(f6i) || f6i == net->ipv6.fib6_null_entry))
+	if (unlikely(err || IS_ERR_OR_NULL(res.f6i) ||
+		     res.f6i == net->ipv6.fib6_null_entry))
 		return BPF_FIB_LKUP_RET_NOT_FWDED;
 
-	if (unlikely(f6i->fib6_flags & RTF_REJECT)) {
-		switch (f6i->fib6_type) {
-		case RTN_BLACKHOLE:
-			return BPF_FIB_LKUP_RET_BLACKHOLE;
-		case RTN_UNREACHABLE:
-			return BPF_FIB_LKUP_RET_UNREACHABLE;
-		case RTN_PROHIBIT:
-			return BPF_FIB_LKUP_RET_PROHIBIT;
-		default:
-			return BPF_FIB_LKUP_RET_NOT_FWDED;
-		}
-	}
-
-	if (f6i->fib6_type != RTN_UNICAST)
+	switch (res.fib6_type) {
+	/* only unicast is forwarded */
+	case RTN_UNICAST:
+		break;
+	case RTN_BLACKHOLE:
+		return BPF_FIB_LKUP_RET_BLACKHOLE;
+	case RTN_UNREACHABLE:
+		return BPF_FIB_LKUP_RET_UNREACHABLE;
+	case RTN_PROHIBIT:
+		return BPF_FIB_LKUP_RET_PROHIBIT;
+	default:
 		return BPF_FIB_LKUP_RET_NOT_FWDED;
+	}
 
-	if (f6i->fib6_nsiblings && fl6.flowi6_oif == 0)
-		f6i = ipv6_stub->fib6_multipath_select(net, f6i, &fl6,
-						       fl6.flowi6_oif, NULL,
-						       strict);
+	ipv6_stub->fib6_select_path(net, &res, &fl6, fl6.flowi6_oif,
+				    fl6.flowi6_oif != 0, NULL, strict);
 
 	if (check_mtu) {
-		mtu = ipv6_stub->ip6_mtu_from_fib6(f6i, dst, src);
+		mtu = ipv6_stub->ip6_mtu_from_fib6(&res, dst, src);
 		if (params->tot_len > mtu)
 			return BPF_FIB_LKUP_RET_FRAG_NEEDED;
 	}
 
-	if (f6i->fib6_nh.fib_nh_lws)
+	if (res.nh->fib_nh_lws)
 		return BPF_FIB_LKUP_RET_UNSUPP_LWT;
 
-	if (f6i->fib6_nh.fib_nh_gw_family)
-		*dst = f6i->fib6_nh.fib_nh_gw6;
+	if (res.nh->fib_nh_gw_family)
+		*dst = res.nh->fib_nh_gw6;
 
-	dev = f6i->fib6_nh.fib_nh_dev;
-	params->rt_metric = f6i->fib6_metric;
+	dev = res.nh->fib_nh_dev;
+	params->rt_metric = res.f6i->fib6_metric;
 
 	/* xdp and cls_bpf programs are run in RCU-bh so rcu_read_lock_bh is
 	 * not needed here.