From 421842edeaf62c4e180b687f5a4efca8c19c49ad Mon Sep 17 00:00:00 2001 From: David Ahern Date: Tue, 17 Apr 2018 17:33:18 -0700 Subject: [PATCH] net/ipv6: Add fib6_null_entry ip6_null_entry will stay a dst based return for lookups that fail to match an entry. Add a new fib6_null_entry which constitutes the root node and leafs for fibs. Replace existing references to ip6_null_entry with the new fib6_null_entry when dealing with FIBs. Signed-off-by: David Ahern Signed-off-by: David S. Miller --- include/net/netns/ipv6.h | 3 +- net/ipv6/ip6_fib.c | 26 ++++++++--------- net/ipv6/route.c | 62 ++++++++++++++++++++++++++++------------ 3 files changed, 58 insertions(+), 33 deletions(-) diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h index c29f09cfc9d734..74e4e1e449d5f5 100644 --- a/include/net/netns/ipv6.h +++ b/include/net/netns/ipv6.h @@ -60,7 +60,8 @@ struct netns_ipv6 { #endif struct xt_table *ip6table_nat; #endif - struct rt6_info *ip6_null_entry; + struct rt6_info *fib6_null_entry; + struct rt6_info *ip6_null_entry; struct rt6_statistics *rt6_stats; struct timer_list ip6_fib_timer; struct hlist_head *fib_table_hash; diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index f25f4d9831e89d..280b69497ad016 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -231,7 +231,7 @@ static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) if (table) { table->tb6_id = id; rcu_assign_pointer(table->tb6_root.leaf, - net->ipv6.ip6_null_entry); + net->ipv6.fib6_null_entry); table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; inet_peer_base_init(&table->tb6_peers); } @@ -369,7 +369,7 @@ struct fib6_dump_arg { static void fib6_rt_dump(struct rt6_info *rt, struct fib6_dump_arg *arg) { - if (rt == arg->net->ipv6.ip6_null_entry) + if (rt == arg->net->ipv6.fib6_null_entry) return; call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); } @@ -658,7 +658,7 @@ static struct fib6_node *fib6_add_1(struct net *net, /* remove null_entry in the root node */ } else if (fn->fn_flags & RTN_TL_ROOT && rcu_access_pointer(fn->leaf) == - net->ipv6.ip6_null_entry) { + net->ipv6.fib6_null_entry) { RCU_INIT_POINTER(fn->leaf, NULL); } @@ -1171,9 +1171,9 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt, if (!sfn) goto failure; - atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); + atomic_inc(&info->nl_net->ipv6.fib6_null_entry->rt6i_ref); rcu_assign_pointer(sfn->leaf, - info->nl_net->ipv6.ip6_null_entry); + info->nl_net->ipv6.fib6_null_entry); sfn->fn_flags = RTN_ROOT; /* Now add the first leaf node to new subtree */ @@ -1212,7 +1212,7 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt, if (fn->fn_flags & RTN_TL_ROOT) { /* put back null_entry for root node */ rcu_assign_pointer(fn->leaf, - info->nl_net->ipv6.ip6_null_entry); + info->nl_net->ipv6.fib6_null_entry); } else { atomic_inc(&rt->rt6i_ref); rcu_assign_pointer(fn->leaf, rt); @@ -1251,7 +1251,7 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt, if (!pn_leaf) { WARN_ON(!pn_leaf); pn_leaf = - info->nl_net->ipv6.ip6_null_entry; + info->nl_net->ipv6.fib6_null_entry; } #endif atomic_inc(&pn_leaf->rt6i_ref); @@ -1494,7 +1494,7 @@ static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *child_left, *child_right; if (fn->fn_flags & RTN_ROOT) - return net->ipv6.ip6_null_entry; + return net->ipv6.fib6_null_entry; while (fn) { child_left = rcu_dereference_protected(fn->left, @@ -1531,7 +1531,7 @@ static struct fib6_node *fib6_repair_tree(struct net *net, /* Set fn->leaf to null_entry for root node. */ if (fn->fn_flags & RTN_TL_ROOT) { - rcu_assign_pointer(fn->leaf, net->ipv6.ip6_null_entry); + rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); return fn; } @@ -1576,7 +1576,7 @@ static struct fib6_node *fib6_repair_tree(struct net *net, #if RT6_DEBUG >= 2 if (!new_fn_leaf) { WARN_ON(!new_fn_leaf); - new_fn_leaf = net->ipv6.ip6_null_entry; + new_fn_leaf = net->ipv6.fib6_null_entry; } #endif atomic_inc(&new_fn_leaf->rt6i_ref); @@ -1726,7 +1726,7 @@ int fib6_del(struct rt6_info *rt, struct nl_info *info) return -ENOENT; } #endif - if (!fn || rt == net->ipv6.ip6_null_entry) + if (!fn || rt == net->ipv6.fib6_null_entry) return -ENOENT; WARN_ON(!(fn->fn_flags & RTN_RTINFO)); @@ -2087,7 +2087,7 @@ static int __net_init fib6_net_init(struct net *net) net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, - net->ipv6.ip6_null_entry); + net->ipv6.fib6_null_entry); net->ipv6.fib6_main_tbl->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); @@ -2099,7 +2099,7 @@ static int __net_init fib6_net_init(struct net *net) goto out_fib6_main_tbl; net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, - net->ipv6.ip6_null_entry); + net->ipv6.fib6_null_entry); net->ipv6.fib6_local_tbl->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); diff --git a/net/ipv6/route.c b/net/ipv6/route.c index f6ca55d21fac35..7c141394d4f10d 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -276,6 +276,15 @@ static const u32 ip6_template_metrics[RTAX_MAX] = { [RTAX_HOPLIMIT - 1] = 0, }; +static const struct rt6_info fib6_null_entry_template = { + .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), + .rt6i_protocol = RTPROT_KERNEL, + .rt6i_metric = ~(u32)0, + .rt6i_ref = ATOMIC_INIT(1), + .fib6_type = RTN_UNREACHABLE, + .fib6_metrics = (struct dst_metrics *)&dst_default_metrics, +}; + static const struct rt6_info ip6_null_entry_template = { .dst = { .__refcnt = ATOMIC_INIT(1), @@ -522,10 +531,10 @@ static inline struct rt6_info *rt6_device_match(struct net *net, return local; if (flags & RT6_LOOKUP_F_IFACE) - return net->ipv6.ip6_null_entry; + return net->ipv6.fib6_null_entry; } - return rt->fib6_nh.nh_flags & RTNH_F_DEAD ? net->ipv6.ip6_null_entry : rt; + return rt->fib6_nh.nh_flags & RTNH_F_DEAD ? net->ipv6.fib6_null_entry : rt; } #ifdef CONFIG_IPV6_ROUTER_PREF @@ -758,8 +767,8 @@ static struct rt6_info *rt6_select(struct net *net, struct fib6_node *fn, bool do_rr = false; int key_plen; - if (!leaf || leaf == net->ipv6.ip6_null_entry) - return net->ipv6.ip6_null_entry; + if (!leaf || leaf == net->ipv6.fib6_null_entry) + return net->ipv6.fib6_null_entry; rt0 = rcu_dereference(fn->rr_ptr); if (!rt0) @@ -776,7 +785,7 @@ static struct rt6_info *rt6_select(struct net *net, struct fib6_node *fn, key_plen = rt0->rt6i_src.plen; #endif if (fn->fn_bit != key_plen) - return net->ipv6.ip6_null_entry; + return net->ipv6.fib6_null_entry; match = find_rr_leaf(fn, leaf, rt0, rt0->rt6i_metric, oif, strict, &do_rr); @@ -797,7 +806,7 @@ static struct rt6_info *rt6_select(struct net *net, struct fib6_node *fn, } } - return match ? match : net->ipv6.ip6_null_entry; + return match ? match : net->ipv6.fib6_null_entry; } static bool rt6_is_gw_or_nonexthop(const struct rt6_info *rt) @@ -1063,7 +1072,7 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net, restart: rt = rcu_dereference(fn->leaf); if (!rt) { - rt = net->ipv6.ip6_null_entry; + rt = net->ipv6.fib6_null_entry; } else { rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif, flags); @@ -1071,7 +1080,7 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net, rt = rt6_multipath_select(net, rt, fl6, fl6->flowi6_oif, skb, flags); } - if (rt == net->ipv6.ip6_null_entry) { + if (rt == net->ipv6.fib6_null_entry) { fn = fib6_backtrack(fn, &fl6->saddr); if (fn) goto restart; @@ -1820,7 +1829,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, rt = rt6_select(net, fn, oif, strict); if (rt->rt6i_nsiblings) rt = rt6_multipath_select(net, rt, fl6, oif, skb, strict); - if (rt == net->ipv6.ip6_null_entry) { + if (rt == net->ipv6.fib6_null_entry) { fn = fib6_backtrack(fn, &fl6->saddr); if (fn) goto redo_rt6_select; @@ -1837,7 +1846,8 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, if (rt_cache) rt = rt_cache; - if (rt == net->ipv6.ip6_null_entry) { + if (rt == net->ipv6.fib6_null_entry) { + rt = net->ipv6.ip6_null_entry; rcu_read_unlock(); dst_hold(&rt->dst); trace_fib6_table_lookup(net, rt, table, fl6); @@ -2412,13 +2422,13 @@ static struct rt6_info *__ip6_route_redirect(struct net *net, } if (!rt) - rt = net->ipv6.ip6_null_entry; + rt = net->ipv6.fib6_null_entry; else if (rt->rt6i_flags & RTF_REJECT) { rt = net->ipv6.ip6_null_entry; goto out; } - if (rt == net->ipv6.ip6_null_entry) { + if (rt == net->ipv6.fib6_null_entry) { fn = fib6_backtrack(fn, &fl6->saddr); if (fn) goto restart; @@ -3051,7 +3061,7 @@ static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info) struct fib6_table *table; int err; - if (rt == net->ipv6.ip6_null_entry) { + if (rt == net->ipv6.fib6_null_entry) { err = -ENOENT; goto out; } @@ -3081,7 +3091,7 @@ static int __ip6_del_rt_siblings(struct rt6_info *rt, struct fib6_config *cfg) struct fib6_table *table; int err = -ENOENT; - if (rt == net->ipv6.ip6_null_entry) + if (rt == net->ipv6.fib6_null_entry) goto out_put; table = rt->rt6i_table; spin_lock_bh(&table->tb6_lock); @@ -3634,7 +3644,7 @@ static int fib6_remove_prefsrc(struct rt6_info *rt, void *arg) struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr; if (((void *)rt->fib6_nh.nh_dev == dev || !dev) && - rt != net->ipv6.ip6_null_entry && + rt != net->ipv6.fib6_null_entry && ipv6_addr_equal(addr, &rt->rt6i_prefsrc.addr)) { spin_lock_bh(&rt6_exception_lock); /* remove prefsrc entry */ @@ -3789,7 +3799,7 @@ static int fib6_ifup(struct rt6_info *rt, void *p_arg) const struct arg_netdev_event *arg = p_arg; struct net *net = dev_net(arg->dev); - if (rt != net->ipv6.ip6_null_entry && rt->fib6_nh.nh_dev == arg->dev) { + if (rt != net->ipv6.fib6_null_entry && rt->fib6_nh.nh_dev == arg->dev) { rt->fib6_nh.nh_flags &= ~arg->nh_flags; fib6_update_sernum_upto_root(net, rt); rt6_multipath_rebalance(rt); @@ -3873,7 +3883,7 @@ static int fib6_ifdown(struct rt6_info *rt, void *p_arg) const struct net_device *dev = arg->dev; struct net *net = dev_net(dev); - if (rt == net->ipv6.ip6_null_entry) + if (rt == net->ipv6.fib6_null_entry) return 0; switch (arg->event) { @@ -4624,7 +4634,7 @@ int rt6_dump_route(struct rt6_info *rt, void *p_arg) struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg; struct net *net = arg->net; - if (rt == net->ipv6.ip6_null_entry) + if (rt == net->ipv6.fib6_null_entry) return 0; if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) { @@ -4813,6 +4823,8 @@ static int ip6_route_dev_notify(struct notifier_block *this, return NOTIFY_OK; if (event == NETDEV_REGISTER) { + net->ipv6.fib6_null_entry->fib6_nh.nh_dev = dev; + net->ipv6.fib6_null_entry->rt6i_idev = in6_dev_get(dev); net->ipv6.ip6_null_entry->dst.dev = dev; net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev); #ifdef CONFIG_IPV6_MULTIPLE_TABLES @@ -4826,6 +4838,7 @@ static int ip6_route_dev_notify(struct notifier_block *this, /* NETDEV_UNREGISTER could be fired for multiple times by * netdev_wait_allrefs(). Make sure we only call this once. */ + in6_dev_put_clear(&net->ipv6.fib6_null_entry->rt6i_idev); in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev); #ifdef CONFIG_IPV6_MULTIPLE_TABLES in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev); @@ -5009,11 +5022,17 @@ static int __net_init ip6_route_net_init(struct net *net) if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0) goto out_ip6_dst_ops; + net->ipv6.fib6_null_entry = kmemdup(&fib6_null_entry_template, + sizeof(*net->ipv6.fib6_null_entry), + GFP_KERNEL); + if (!net->ipv6.fib6_null_entry) + goto out_ip6_dst_entries; + net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template, sizeof(*net->ipv6.ip6_null_entry), GFP_KERNEL); if (!net->ipv6.ip6_null_entry) - goto out_ip6_dst_entries; + goto out_fib6_null_entry; net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops; dst_init_metrics(&net->ipv6.ip6_null_entry->dst, ip6_template_metrics, true); @@ -5060,6 +5079,8 @@ static int __net_init ip6_route_net_init(struct net *net) out_ip6_null_entry: kfree(net->ipv6.ip6_null_entry); #endif +out_fib6_null_entry: + kfree(net->ipv6.fib6_null_entry); out_ip6_dst_entries: dst_entries_destroy(&net->ipv6.ip6_dst_ops); out_ip6_dst_ops: @@ -5068,6 +5089,7 @@ static int __net_init ip6_route_net_init(struct net *net) static void __net_exit ip6_route_net_exit(struct net *net) { + kfree(net->ipv6.fib6_null_entry); kfree(net->ipv6.ip6_null_entry); #ifdef CONFIG_IPV6_MULTIPLE_TABLES kfree(net->ipv6.ip6_prohibit_entry); @@ -5138,6 +5160,8 @@ void __init ip6_route_init_special_entries(void) /* Registering of the loopback is done before this portion of code, * the loopback reference in rt6_info will not be taken, do it * manually for init_net */ + init_net.ipv6.fib6_null_entry->fib6_nh.nh_dev = init_net.loopback_dev; + init_net.ipv6.fib6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev; init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); #ifdef CONFIG_IPV6_MULTIPLE_TABLES