ipv6: Rename fib6_multipath_select and pass fib6_result

Add 'struct fib6_result' to hold the fib entry and fib6_nh from a fib
lookup as separate entries, similar to what IPv4 now has with fib_result.

Rename fib6_multipath_select to fib6_select_path, pass fib6_result to
it, and set f6i and nh in the result once a path selection is done.
Call fib6_select_path unconditionally for path selection which means
moving the sibling and oif check to fib6_select_path. To handle the two
different call paths (2 only call multipath_select if flowi6_oif == 0 and
the other always calls it), add a new have_oif_match that controls the
sibling walk if relevant.

Update callers of fib6_multipath_select accordingly and have them use the
fib6_info and fib6_nh from the result.

This is needed for multipath nexthop objects where a single f6i can
point to multiple fib6_nh (similar to IPv4).

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 17 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index 07687e2a2e66..c8dcce205872 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4679,9 +4679,9 @@ 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;
@@ -4726,21 +4726,23 @@ 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);
+		res.f6i = ipv6_stub->fib6_table_lookup(net, tb, oif, &fl6,
+						       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);
+		res.f6i = ipv6_stub->fib6_lookup(net, oif, &fl6, strict);
 	}
 
-	if (unlikely(IS_ERR_OR_NULL(f6i) || f6i == net->ipv6.fib6_null_entry))
+	if (unlikely(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) {
+	if (unlikely(res.f6i->fib6_flags & RTF_REJECT)) {
+		switch (res.f6i->fib6_type) {
 		case RTN_BLACKHOLE:
 			return BPF_FIB_LKUP_RET_BLACKHOLE;
 		case RTN_UNREACHABLE:
@@ -4752,28 +4754,26 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
 		}
 	}
 
-	if (f6i->fib6_type != RTN_UNICAST)
+	if (res.f6i->fib6_type != RTN_UNICAST)
 		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.f6i, 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.