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>

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 2e9235a..c4d8180 100644 (file)
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -190,6 +190,11 @@ struct rt6_info {
        unsigned short                  rt6i_nfheader_len;
 };
 
+struct fib6_result {
+       struct fib6_nh          *nh;
+       struct fib6_info        *f6i;
+};
+
 #define for_each_fib6_node_rt_rcu(fn)                                  \
        for (rt = rcu_dereference((fn)->leaf); rt;                      \
             rt = rcu_dereference(rt->fib6_next))
@@ -391,11 +396,9 @@ struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
 struct fib6_info *fib6_table_lookup(struct net *net, struct fib6_table *table,
                                    int oif, struct flowi6 *fl6, int strict);
 
-struct fib6_info *fib6_multipath_select(const struct net *net,
-                                       struct fib6_info *match,
-                                       struct flowi6 *fl6, int oif,
-                                       const struct sk_buff *skb, int strict);
-
+void fib6_select_path(const struct net *net, struct fib6_result *res,
+                     struct flowi6 *fl6, int oif, bool have_oif_match,
+                     const struct sk_buff *skb, int strict);
 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
                                   const struct in6_addr *daddr,
                                   const struct in6_addr *saddr);

diff --git a/include/net/ipv6_stubs.h b/include/net/ipv6_stubs.h
index 453b55b..5df36d6 100644 (file)
--- a/include/net/ipv6_stubs.h
+++ b/include/net/ipv6_stubs.h
@@ -14,6 +14,7 @@
 struct fib6_info;
 struct fib6_nh;
 struct fib6_config;
+struct fib6_result;
 
 /* This is ugly, ideally these symbols should be built
  * into the core kernel.
@@ -34,11 +35,9 @@ struct ipv6_stub {
                                              struct fib6_table *table,
                                              int oif, struct flowi6 *fl6,
                                              int flags);
-       struct fib6_info *(*fib6_multipath_select)(const struct net *net,
-                                                  struct fib6_info *f6i,
-                                                  struct flowi6 *fl6, int oif,
-                                                  const struct sk_buff *skb,
-                                                  int strict);
+       void (*fib6_select_path)(const struct net *net, struct fib6_result *res,
+                                struct flowi6 *fl6, int oif, bool oif_match,
+                                const struct sk_buff *skb, int strict);
        u32 (*ip6_mtu_from_fib6)(struct fib6_info *f6i, struct in6_addr *daddr,
                                 struct in6_addr *saddr);
 

diff --git a/net/core/filter.c b/net/core/filter.c
index 07687e2..c8dcce2 100644 (file)
--- 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.

diff --git a/net/ipv6/addrconf_core.c b/net/ipv6/addrconf_core.c
index e37e4c5..b11fa0a 100644 (file)
--- a/net/ipv6/addrconf_core.c
+++ b/net/ipv6/addrconf_core.c
@@ -158,12 +158,11 @@ eafnosupport_fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
        return NULL;
 }
 
-static struct fib6_info *
-eafnosupport_fib6_multipath_select(const struct net *net, struct fib6_info *f6i,
-                                  struct flowi6 *fl6, int oif,
-                                  const struct sk_buff *skb, int strict)
+static void
+eafnosupport_fib6_select_path(const struct net *net, struct fib6_result *res,
+                             struct flowi6 *fl6, int oif, bool have_oif_match,
+                             const struct sk_buff *skb, int strict)
 {
-       return f6i;
 }
 
 static u32
@@ -187,7 +186,7 @@ const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
        .fib6_get_table    = eafnosupport_fib6_get_table,
        .fib6_table_lookup = eafnosupport_fib6_table_lookup,
        .fib6_lookup       = eafnosupport_fib6_lookup,
-       .fib6_multipath_select = eafnosupport_fib6_multipath_select,
+       .fib6_select_path  = eafnosupport_fib6_select_path,
        .ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
        .fib6_nh_init      = eafnosupport_fib6_nh_init,
 };

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 1dac6ea..d8587ca 100644 (file)
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -917,7 +917,7 @@ static const struct ipv6_stub ipv6_stub_impl = {
        .fib6_get_table    = fib6_get_table,
        .fib6_table_lookup = fib6_table_lookup,
        .fib6_lookup       = fib6_lookup,
-       .fib6_multipath_select = fib6_multipath_select,
+       .fib6_select_path  = fib6_select_path,
        .ip6_mtu_from_fib6 = ip6_mtu_from_fib6,
        .fib6_nh_init      = fib6_nh_init,
        .fib6_nh_release   = fib6_nh_release,

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 9ece806..0ad77b6 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -428,13 +428,15 @@ static bool rt6_check_expired(const struct rt6_info *rt)
        return false;
 }
 
-struct fib6_info *fib6_multipath_select(const struct net *net,
-                                       struct fib6_info *match,
-                                       struct flowi6 *fl6, int oif,
-                                       const struct sk_buff *skb,
-                                       int strict)
+void fib6_select_path(const struct net *net, struct fib6_result *res,
+                     struct flowi6 *fl6, int oif, bool have_oif_match,
+                     const struct sk_buff *skb, int strict)
 {
        struct fib6_info *sibling, *next_sibling;
+       struct fib6_info *match = res->f6i;
+
+       if (!match->fib6_nsiblings || have_oif_match)
+               goto out;
 
        /* We might have already computed the hash for ICMPv6 errors. In such
         * case it will always be non-zero. Otherwise now is the time to do it.
@@ -443,7 +445,7 @@ struct fib6_info *fib6_multipath_select(const struct net *net,
                fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
 
        if (fl6->mp_hash <= atomic_read(&match->fib6_nh.fib_nh_upper_bound))
-               return match;
+               goto out;
 
        list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
                                 fib6_siblings) {
@@ -459,7 +461,9 @@ struct fib6_info *fib6_multipath_select(const struct net *net,
                break;
        }
 
-       return match;
+out:
+       res->f6i = match;
+       res->nh = &match->fib6_nh;
 }
 
 /*
@@ -1063,7 +1067,7 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net,
                                             const struct sk_buff *skb,
                                             int flags)
 {
-       struct fib6_info *f6i;
+       struct fib6_result res = {};
        struct fib6_node *fn;
        struct rt6_info *rt;
 
@@ -1073,14 +1077,14 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net,
        rcu_read_lock();
        fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
 restart:
-       f6i = rcu_dereference(fn->leaf);
-       if (!f6i)
-               f6i = net->ipv6.fib6_null_entry;
+       res.f6i = rcu_dereference(fn->leaf);
+       if (!res.f6i)
+               res.f6i = net->ipv6.fib6_null_entry;
        else
-               f6i = rt6_device_match(net, f6i, &fl6->saddr,
-                                     fl6->flowi6_oif, flags);
+               res.f6i = rt6_device_match(net, res.f6i, &fl6->saddr,
+                                          fl6->flowi6_oif, flags);
 
-       if (f6i == net->ipv6.fib6_null_entry) {
+       if (res.f6i == net->ipv6.fib6_null_entry) {
                fn = fib6_backtrack(fn, &fl6->saddr);
                if (fn)
                        goto restart;
@@ -1090,20 +1094,20 @@ restart:
                goto out;
        }
 
-       if (f6i->fib6_nsiblings && fl6->flowi6_oif == 0)
-               f6i = fib6_multipath_select(net, f6i, fl6, fl6->flowi6_oif, skb,
-                                           flags);
+       fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
+                        fl6->flowi6_oif != 0, skb, flags);
+
        /* Search through exception table */
-       rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr);
+       rt = rt6_find_cached_rt(res.f6i, &fl6->daddr, &fl6->saddr);
        if (rt) {
                if (ip6_hold_safe(net, &rt))
                        dst_use_noref(&rt->dst, jiffies);
        } else {
-               rt = ip6_create_rt_rcu(f6i);
+               rt = ip6_create_rt_rcu(res.f6i);
        }
 
 out:
-       trace_fib6_table_lookup(net, f6i, table, fl6);
+       trace_fib6_table_lookup(net, res.f6i, table, fl6);
 
        rcu_read_unlock();
 
@@ -1843,7 +1847,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
                               int oif, struct flowi6 *fl6,
                               const struct sk_buff *skb, int flags)
 {
-       struct fib6_info *f6i;
+       struct fib6_result res = {};
        struct rt6_info *rt;
        int strict = 0;
 
@@ -1854,19 +1858,18 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
 
        rcu_read_lock();
 
-       f6i = fib6_table_lookup(net, table, oif, fl6, strict);
-       if (f6i == net->ipv6.fib6_null_entry) {
+       res.f6i = fib6_table_lookup(net, table, oif, fl6, strict);
+       if (res.f6i == net->ipv6.fib6_null_entry) {
                rt = net->ipv6.ip6_null_entry;
                rcu_read_unlock();
                dst_hold(&rt->dst);
                return rt;
        }
 
-       if (f6i->fib6_nsiblings)
-               f6i = fib6_multipath_select(net, f6i, fl6, oif, skb, strict);
+       fib6_select_path(net, &res, fl6, oif, false, skb, strict);
 
        /*Search through exception table */
-       rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr);
+       rt = rt6_find_cached_rt(res.f6i, &fl6->daddr, &fl6->saddr);
        if (rt) {
                if (ip6_hold_safe(net, &rt))
                        dst_use_noref(&rt->dst, jiffies);
@@ -1874,7 +1877,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
                rcu_read_unlock();
                return rt;
        } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
-                           !f6i->fib6_nh.fib_nh_gw_family)) {
+                           !res.nh->fib_nh_gw_family)) {
                /* Create a RTF_CACHE clone which will not be
                 * owned by the fib6 tree.  It is for the special case where
                 * the daddr in the skb during the neighbor look-up is different
@@ -1882,7 +1885,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
                 */
                struct rt6_info *uncached_rt;
 
-               uncached_rt = ip6_rt_cache_alloc(f6i, &fl6->daddr, NULL);
+               uncached_rt = ip6_rt_cache_alloc(res.f6i, &fl6->daddr, NULL);
 
                rcu_read_unlock();
 
@@ -1904,10 +1907,10 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
                struct rt6_info *pcpu_rt;
 
                local_bh_disable();
-               pcpu_rt = rt6_get_pcpu_route(f6i);
+               pcpu_rt = rt6_get_pcpu_route(res.f6i);
 
                if (!pcpu_rt)
-                       pcpu_rt = rt6_make_pcpu_route(net, f6i);
+                       pcpu_rt = rt6_make_pcpu_route(net, res.f6i);
 
                local_bh_enable();
                rcu_read_unlock();