ipv6: Add fib6_type and fib6_flags to fib6_result

Add the fib6_flags and fib6_type to fib6_result. Update the lookup helpers
to set them and update post fib lookup users to use the version from the
result.

This allows nexthop objects to have blackhole nexthop.

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

2 files changed, 49 insertions, 38 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index d17347cbeb1e..1644a16afcec 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4741,21 +4741,19 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
                      res.f6i == net->ipv6.fib6_null_entry))
                 return BPF_FIB_LKUP_RET_NOT_FWDED;
 
-        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:
-                        return BPF_FIB_LKUP_RET_UNREACHABLE;
-                case RTN_PROHIBIT:
-                        return BPF_FIB_LKUP_RET_PROHIBIT;
-                default:
-                        return BPF_FIB_LKUP_RET_NOT_FWDED;
-                }
-        }
-
-        if (res.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;
+        }
 
         ipv6_stub->fib6_select_path(net, &res, &fl6, fl6.flowi6_oif,
                                     fl6.flowi6_oif != 0, NULL, strict);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 5a1e1176c33c..e8c73b7782cd 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -500,31 +500,33 @@ static void rt6_device_match(struct net *net, struct fib6_result *res,
 
         if (!oif && ipv6_addr_any(saddr)) {
                 nh = &f6i->fib6_nh;
-                if (!(nh->fib_nh_flags & RTNH_F_DEAD)) {
-                        res->nh = nh;
-                        return;
-                }
+                if (!(nh->fib_nh_flags & RTNH_F_DEAD))
+                        goto out;
         }
 
         for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
                 nh = &spf6i->fib6_nh;
                 if (__rt6_device_match(net, nh, saddr, oif, flags)) {
                         res->f6i = spf6i;
-                        res->nh = nh;
+                        goto out;
                 }
         }
 
         if (oif && flags & RT6_LOOKUP_F_IFACE) {
                 res->f6i = net->ipv6.fib6_null_entry;
-                res->nh = &res->f6i->fib6_nh;
-                return;
+                nh = &res->f6i->fib6_nh;
+                goto out;
         }
 
-        res->nh = &f6i->fib6_nh;
-        if (res->nh->fib_nh_flags & RTNH_F_DEAD) {
+        nh = &f6i->fib6_nh;
+        if (nh->fib_nh_flags & RTNH_F_DEAD) {
                 res->f6i = net->ipv6.fib6_null_entry;
-                res->nh = &res->f6i->fib6_nh;
+                nh = &res->f6i->fib6_nh;
         }
+out:
+        res->nh = nh;
+        res->fib6_type = res->f6i->fib6_type;
+        res->fib6_flags = res->f6i->fib6_flags;
 }
 
 #ifdef CONFIG_IPV6_ROUTER_PREF
@@ -719,6 +721,8 @@ static void __find_rr_leaf(struct fib6_info *f6i_start,
                 if (find_match(nh, f6i->fib6_flags, oif, strict, mpri, do_rr)) {
                         res->f6i = f6i;
                         res->nh = nh;
+                        res->fib6_flags = f6i->fib6_flags;
+                        res->fib6_type = f6i->fib6_type;
                 }
         }
 }
@@ -796,6 +800,8 @@ out:
         if (!res->f6i) {
                 res->f6i = net->ipv6.fib6_null_entry;
                 res->nh = &res->f6i->fib6_nh;
+                res->fib6_flags = res->f6i->fib6_flags;
+                res->fib6_type = res->f6i->fib6_type;
         }
 }
 
@@ -889,15 +895,14 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
 {
         struct net_device *dev = res->nh->fib_nh_dev;
-        const struct fib6_info *f6i = res->f6i;
 
-        if (f6i->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
+        if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
                 /* for copies of local routes, dst->dev needs to be the
                  * device if it is a master device, the master device if
                  * device is enslaved, and the loopback as the default
                  */
                 if (netif_is_l3_slave(dev) &&
-                    !rt6_need_strict(&f6i->fib6_dst.addr))
+                    !rt6_need_strict(&res->f6i->fib6_dst.addr))
                         dev = l3mdev_master_dev_rcu(dev);
                 else if (!netif_is_l3_master(dev))
                         dev = dev_net(dev)->loopback_dev;
@@ -943,11 +948,11 @@ static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
         return flags;
 }
 
-static void ip6_rt_init_dst_reject(struct rt6_info *rt, struct fib6_info *ort)
+static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
 {
-        rt->dst.error = ip6_rt_type_to_error(ort->fib6_type);
+        rt->dst.error = ip6_rt_type_to_error(fib6_type);
 
-        switch (ort->fib6_type) {
+        switch (fib6_type) {
         case RTN_BLACKHOLE:
                 rt->dst.output = dst_discard_out;
                 rt->dst.input = dst_discard;
@@ -967,19 +972,19 @@ static void ip6_rt_init_dst_reject(struct rt6_info *rt, struct fib6_info *ort)
 
 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
 {
-        struct fib6_info *ort = res->f6i;
+        struct fib6_info *f6i = res->f6i;
 
-        if (ort->fib6_flags & RTF_REJECT) {
-                ip6_rt_init_dst_reject(rt, ort);
+        if (res->fib6_flags & RTF_REJECT) {
+                ip6_rt_init_dst_reject(rt, res->fib6_type);
                 return;
         }
 
         rt->dst.error = 0;
         rt->dst.output = ip6_output;
 
-        if (ort->fib6_type == RTN_LOCAL || ort->fib6_type == RTN_ANYCAST) {
+        if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
                 rt->dst.input = ip6_input;
-        } else if (ipv6_addr_type(&ort->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
+        } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
                 rt->dst.input = ip6_mc_input;
         } else {
                 rt->dst.input = ip6_forward;
@@ -1012,7 +1017,7 @@ static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
 
         rt->rt6i_dst = f6i->fib6_dst;
         rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
-        rt->rt6i_flags = f6i->fib6_flags;
+        rt->rt6i_flags = res->fib6_flags;
         if (nh->fib_nh_gw_family) {
                 rt->rt6i_gateway = nh->fib_nh_gw6;
                 rt->rt6i_flags |= RTF_GATEWAY;
@@ -2365,6 +2370,9 @@ static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
                         return;
                 }
                 res.nh = &res.f6i->fib6_nh;
+                res.fib6_flags = res.f6i->fib6_flags;
+                res.fib6_type = res.f6i->fib6_type;
+
                 nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
                 if (nrt6) {
                         rt6_do_update_pmtu(nrt6, mtu);
@@ -2530,10 +2538,13 @@ restart:
         res.f6i = rt;
         res.nh = &rt->fib6_nh;
 out:
-        if (ret)
+        if (ret) {
                 ip6_hold_safe(net, &ret);
-        else
+        } else {
+                res.fib6_flags = res.f6i->fib6_flags;
+                res.fib6_type = res.f6i->fib6_type;
                 ret = ip6_create_rt_rcu(&res);
+        }
 
         rcu_read_unlock();
 
@@ -3491,6 +3502,8 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu
         rcu_read_unlock();
 
         res.nh = &res.f6i->fib6_nh;
+        res.fib6_flags = res.f6i->fib6_flags;
+        res.fib6_type = res.f6i->fib6_type;
         nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
         if (!nrt)
                 goto out;