From 138118ec96cbfc303c1d7cc05fbb2caf8382c95b Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 9 May 2018 20:34:23 -0700 Subject: [PATCH] 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: David Ahern Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- include/net/ip6_fib.h | 6 +++ net/ipv6/fib6_rules.c | 86 ++++++++++++++++++++++++++++++++++++++++++- net/ipv6/ip6_fib.c | 7 ++++ 3 files changed, 97 insertions(+), 2 deletions(-) diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index c70705f2647a..cc70f6da8462 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -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); diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c index d040c4bff3a0..f590446595d8 100644 --- a/net/ipv6/fib6_rules.c +++ b/net/ipv6/fib6_rules.c @@ -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) @@ -121,8 +154,48 @@ 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, - int flags, struct fib_lookup_arg *arg) +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; struct rt6_info *rt = NULL; @@ -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; diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index 487faffeae28..d1dc6017f5a6 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -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); -- 2.30.2