Commit 138118ec authored by David Ahern's avatar David Ahern Committed by Daniel Borkmann
Browse files

net/ipv6: Add fib6_lookup 



Add IPv6 equivalent to fib_lookup. Does a fib lookup, including rules,
but returns a FIB entry, fib6_info, rather than a dst based rt6_info.
fib6_lookup is any where from 140% (MULTIPLE_TABLES config disabled)
to 60% faster than any of the dst based lookup methods (without custom
rules) and 25% faster with custom rules (e.g., l3mdev rule).

Since the lookup function has a completely different signature,
fib6_rule_action is split into 2 paths: the existing one is
renamed __fib6_rule_action and a new one for the fib6_info path
is added. fib6_rule_action decides which to call based on the
lookup_ptr. If it is fib6_table_lookup then the new path is taken.

Caller must hold rcu lock as no reference is taken on the returned
fib entry.

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent cc065a9e

include/net/ip6_fib.h

+6 −0
Original line number Diff line number Diff line
@@ -376,6 +376,12 @@ struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 
				   const struct sk_buff *skb,

				   int flags, pol_lookup_t lookup);



/* called with rcu lock held; can return error pointer

 * caller needs to select path

 */

struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,

			      int flags);



/* called with rcu lock held; caller needs to select path */

struct fib6_info *fib6_table_lookup(struct net *net, struct fib6_table *table,

				    int oif, struct flowi6 *fl6, int strict);

net/ipv6/fib6_rules.c

+84 −2
Original line number Diff line number Diff line
@@ -60,6 +60,39 @@ unsigned int fib6_rules_seq_read(struct net *net) 
	return fib_rules_seq_read(net, AF_INET6);

}



/* called with rcu lock held; no reference taken on fib6_info */

struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,

			      int flags)

{

	struct fib6_info *f6i;

	int err;



	if (net->ipv6.fib6_has_custom_rules) {

		struct fib_lookup_arg arg = {

			.lookup_ptr = fib6_table_lookup,

			.lookup_data = &oif,

			.flags = FIB_LOOKUP_NOREF,

		};



		l3mdev_update_flow(net, flowi6_to_flowi(fl6));



		err = fib_rules_lookup(net->ipv6.fib6_rules_ops,

				       flowi6_to_flowi(fl6), flags, &arg);

		if (err)

			return ERR_PTR(err);



		f6i = arg.result ? : net->ipv6.fib6_null_entry;

	} else {

		f6i = fib6_table_lookup(net, net->ipv6.fib6_local_tbl,

					oif, fl6, flags);

		if (!f6i || f6i == net->ipv6.fib6_null_entry)

			f6i = fib6_table_lookup(net, net->ipv6.fib6_main_tbl,

						oif, fl6, flags);

	}



	return f6i;

}



struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,

				   const struct sk_buff *skb,

				   int flags, pol_lookup_t lookup)
@@ -121,7 +154,47 @@ static int fib6_rule_saddr(struct net *net, struct fib_rule *rule, int flags, 
	return 0;

}



static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,

static int fib6_rule_action_alt(struct fib_rule *rule, struct flowi *flp,

				int flags, struct fib_lookup_arg *arg)

{

	struct flowi6 *flp6 = &flp->u.ip6;

	struct net *net = rule->fr_net;

	struct fib6_table *table;

	struct fib6_info *f6i;

	int err = -EAGAIN, *oif;

	u32 tb_id;



	switch (rule->action) {

	case FR_ACT_TO_TBL:

		break;

	case FR_ACT_UNREACHABLE:

		return -ENETUNREACH;

	case FR_ACT_PROHIBIT:

		return -EACCES;

	case FR_ACT_BLACKHOLE:

	default:

		return -EINVAL;

	}



	tb_id = fib_rule_get_table(rule, arg);

	table = fib6_get_table(net, tb_id);

	if (!table)

		return -EAGAIN;



	oif = (int *)arg->lookup_data;

	f6i = fib6_table_lookup(net, table, *oif, flp6, flags);

	if (f6i != net->ipv6.fib6_null_entry) {

		err = fib6_rule_saddr(net, rule, flags, flp6,

				      fib6_info_nh_dev(f6i));



		if (likely(!err))

			arg->result = f6i;

	}



	return err;

}



static int __fib6_rule_action(struct fib_rule *rule, struct flowi *flp,

			      int flags, struct fib_lookup_arg *arg)

{

	struct flowi6 *flp6 = &flp->u.ip6;
@@ -182,6 +255,15 @@ out: 
	return err;

}



static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,

			    int flags, struct fib_lookup_arg *arg)

{

	if (arg->lookup_ptr == fib6_table_lookup)

		return fib6_rule_action_alt(rule, flp, flags, arg);



	return __fib6_rule_action(rule, flp, flags, arg);

}



static bool fib6_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)

{

	struct rt6_info *rt = (struct rt6_info *) arg->result;

net/ipv6/ip6_fib.c

+7 −0
Original line number Diff line number Diff line
@@ -354,6 +354,13 @@ struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 
	return &rt->dst;

}



/* called with rcu lock held; no reference taken on fib6_info */

struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,

			      int flags)

{

	return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, flags);

}



static void __net_init fib6_tables_init(struct net *net)

{

	fib6_link_table(net, net->ipv6.fib6_main_tbl);

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