From 04b1d4e50e82536c12da00ee04a77510c459c844 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Thu, 3 Aug 2017 13:28:11 +0200 Subject: [PATCH] net: core: Make the FIB notification chain generic The FIB notification chain is currently soley used by IPv4 code. However, we're going to introduce IPv6 FIB offload support, which requires these notification as well. As explained in commit c3852ef7f2f8 ("ipv4: fib: Replay events when registering FIB notifier"), upon registration to the chain, the callee receives a full dump of the FIB tables and rules by traversing all the net namespaces. The integrity of the dump is ensured by a per-namespace sequence counter that is incremented whenever a change to the tables or rules occurs. In order to allow more address families to use the chain, each family is expected to register its fib_notifier_ops in its pernet init. These operations allow the common code to read the family's sequence counter as well as dump its tables and rules in the given net namespace. Additionally, a 'family' parameter is added to sent notifications, so that listeners could distinguish between the different families. Implement the common code that allows listeners to register to the chain and for address families to register their fib_notifier_ops. Subsequent patches will implement these operations in IPv6. In the future, ipmr and ip6mr will be extended to provide these notifications as well. Signed-off-by: Ido Schimmel Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- .../ethernet/mellanox/mlxsw/spectrum_router.c | 1 + drivers/net/ethernet/rocker/rocker_main.c | 1 + include/net/fib_notifier.h | 44 +++++ include/net/ip_fib.h | 30 +--- include/net/net_namespace.h | 1 + include/net/netns/ipv4.h | 1 + net/core/Makefile | 3 +- net/core/fib_notifier.c | 164 ++++++++++++++++++ net/ipv4/fib_frontend.c | 17 +- net/ipv4/fib_notifier.c | 94 ++++------ net/ipv4/fib_rules.c | 5 +- net/ipv4/fib_semantics.c | 9 +- net/ipv4/fib_trie.c | 5 +- 13 files changed, 282 insertions(+), 93 deletions(-) create mode 100644 include/net/fib_notifier.h create mode 100644 net/core/fib_notifier.c diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c index 2f03c7e71584..b79f9b67f285 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c @@ -53,6 +53,7 @@ #include #include #include +#include #include "spectrum.h" #include "core.h" diff --git a/drivers/net/ethernet/rocker/rocker_main.c b/drivers/net/ethernet/rocker/rocker_main.c index b1e5c07099fa..ef38c1a41bdd 100644 --- a/drivers/net/ethernet/rocker/rocker_main.c +++ b/drivers/net/ethernet/rocker/rocker_main.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include diff --git a/include/net/fib_notifier.h b/include/net/fib_notifier.h new file mode 100644 index 000000000000..241475224f74 --- /dev/null +++ b/include/net/fib_notifier.h @@ -0,0 +1,44 @@ +#ifndef __NET_FIB_NOTIFIER_H +#define __NET_FIB_NOTIFIER_H + +#include +#include +#include + +struct fib_notifier_info { + struct net *net; + int family; +}; + +enum fib_event_type { + FIB_EVENT_ENTRY_REPLACE, + FIB_EVENT_ENTRY_APPEND, + FIB_EVENT_ENTRY_ADD, + FIB_EVENT_ENTRY_DEL, + FIB_EVENT_RULE_ADD, + FIB_EVENT_RULE_DEL, + FIB_EVENT_NH_ADD, + FIB_EVENT_NH_DEL, +}; + +struct fib_notifier_ops { + int family; + struct list_head list; + unsigned int (*fib_seq_read)(struct net *net); + int (*fib_dump)(struct net *net, struct notifier_block *nb); + struct rcu_head rcu; +}; + +int call_fib_notifier(struct notifier_block *nb, struct net *net, + enum fib_event_type event_type, + struct fib_notifier_info *info); +int call_fib_notifiers(struct net *net, enum fib_event_type event_type, + struct fib_notifier_info *info); +int register_fib_notifier(struct notifier_block *nb, + void (*cb)(struct notifier_block *nb)); +int unregister_fib_notifier(struct notifier_block *nb); +struct fib_notifier_ops * +fib_notifier_ops_register(const struct fib_notifier_ops *tmpl, struct net *net); +void fib_notifier_ops_unregister(struct fib_notifier_ops *ops); + +#endif diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h index ef8992d49bc3..c0295c3ec5f3 100644 --- a/include/net/ip_fib.h +++ b/include/net/ip_fib.h @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -188,10 +189,6 @@ __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ FIB_RES_SADDR(net, res)) -struct fib_notifier_info { - struct net *net; -}; - struct fib_entry_notifier_info { struct fib_notifier_info info; /* must be first */ u32 dst; @@ -212,25 +209,14 @@ struct fib_nh_notifier_info { struct fib_nh *fib_nh; }; -enum fib_event_type { - FIB_EVENT_ENTRY_REPLACE, - FIB_EVENT_ENTRY_APPEND, - FIB_EVENT_ENTRY_ADD, - FIB_EVENT_ENTRY_DEL, - FIB_EVENT_RULE_ADD, - FIB_EVENT_RULE_DEL, - FIB_EVENT_NH_ADD, - FIB_EVENT_NH_DEL, -}; - -int register_fib_notifier(struct notifier_block *nb, - void (*cb)(struct notifier_block *nb)); -int unregister_fib_notifier(struct notifier_block *nb); -int call_fib_notifier(struct notifier_block *nb, struct net *net, - enum fib_event_type event_type, - struct fib_notifier_info *info); -int call_fib_notifiers(struct net *net, enum fib_event_type event_type, +int call_fib4_notifier(struct notifier_block *nb, struct net *net, + enum fib_event_type event_type, struct fib_notifier_info *info); +int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, + struct fib_notifier_info *info); + +int __net_init fib4_notifier_init(struct net *net); +void __net_exit fib4_notifier_exit(struct net *net); void fib_notify(struct net *net, struct notifier_block *nb); #ifdef CONFIG_IP_MULTIPLE_TABLES diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 1c401bd4c2e0..57faa375eab9 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -88,6 +88,7 @@ struct net { /* core fib_rules */ struct list_head rules_ops; + struct list_head fib_notifier_ops; /* protected by net_mutex */ struct net_device *loopback_dev; /* The loopback */ struct netns_core core; diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 9a14a0850b0e..20d061c805e3 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -159,6 +159,7 @@ struct netns_ipv4 { int sysctl_fib_multipath_hash_policy; #endif + struct fib_notifier_ops *notifier_ops; unsigned int fib_seq; /* protected by rtnl_mutex */ atomic_t rt_genid; diff --git a/net/core/Makefile b/net/core/Makefile index d501c4278015..56d771a887b6 100644 --- a/net/core/Makefile +++ b/net/core/Makefile @@ -9,7 +9,8 @@ obj-$(CONFIG_SYSCTL) += sysctl_net_core.o obj-y += dev.o ethtool.o dev_addr_lists.o dst.o netevent.o \ neighbour.o rtnetlink.o utils.o link_watch.o filter.o \ - sock_diag.o dev_ioctl.o tso.o sock_reuseport.o + sock_diag.o dev_ioctl.o tso.o sock_reuseport.o \ + fib_notifier.o obj-y += net-sysfs.o obj-$(CONFIG_PROC_FS) += net-procfs.o diff --git a/net/core/fib_notifier.c b/net/core/fib_notifier.c new file mode 100644 index 000000000000..292aab83702f --- /dev/null +++ b/net/core/fib_notifier.c @@ -0,0 +1,164 @@ +#include +#include +#include +#include +#include +#include +#include + +static ATOMIC_NOTIFIER_HEAD(fib_chain); + +int call_fib_notifier(struct notifier_block *nb, struct net *net, + enum fib_event_type event_type, + struct fib_notifier_info *info) +{ + info->net = net; + return nb->notifier_call(nb, event_type, info); +} +EXPORT_SYMBOL(call_fib_notifier); + +int call_fib_notifiers(struct net *net, enum fib_event_type event_type, + struct fib_notifier_info *info) +{ + info->net = net; + return atomic_notifier_call_chain(&fib_chain, event_type, info); +} +EXPORT_SYMBOL(call_fib_notifiers); + +static unsigned int fib_seq_sum(void) +{ + struct fib_notifier_ops *ops; + unsigned int fib_seq = 0; + struct net *net; + + rtnl_lock(); + for_each_net(net) { + list_for_each_entry(ops, &net->fib_notifier_ops, list) + fib_seq += ops->fib_seq_read(net); + } + rtnl_unlock(); + + return fib_seq; +} + +static int fib_net_dump(struct net *net, struct notifier_block *nb) +{ + struct fib_notifier_ops *ops; + + list_for_each_entry_rcu(ops, &net->fib_notifier_ops, list) { + int err = ops->fib_dump(net, nb); + + if (err) + return err; + } + + return 0; +} + +static bool fib_dump_is_consistent(struct notifier_block *nb, + void (*cb)(struct notifier_block *nb), + unsigned int fib_seq) +{ + atomic_notifier_chain_register(&fib_chain, nb); + if (fib_seq == fib_seq_sum()) + return true; + atomic_notifier_chain_unregister(&fib_chain, nb); + if (cb) + cb(nb); + return false; +} + +#define FIB_DUMP_MAX_RETRIES 5 +int register_fib_notifier(struct notifier_block *nb, + void (*cb)(struct notifier_block *nb)) +{ + int retries = 0; + int err; + + do { + unsigned int fib_seq = fib_seq_sum(); + struct net *net; + + rcu_read_lock(); + for_each_net_rcu(net) { + err = fib_net_dump(net, nb); + if (err) + goto err_fib_net_dump; + } + rcu_read_unlock(); + + if (fib_dump_is_consistent(nb, cb, fib_seq)) + return 0; + } while (++retries < FIB_DUMP_MAX_RETRIES); + + return -EBUSY; + +err_fib_net_dump: + rcu_read_unlock(); + return err; +} +EXPORT_SYMBOL(register_fib_notifier); + +int unregister_fib_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_unregister(&fib_chain, nb); +} +EXPORT_SYMBOL(unregister_fib_notifier); + +static int __fib_notifier_ops_register(struct fib_notifier_ops *ops, + struct net *net) +{ + struct fib_notifier_ops *o; + + list_for_each_entry(o, &net->fib_notifier_ops, list) + if (ops->family == o->family) + return -EEXIST; + list_add_tail_rcu(&ops->list, &net->fib_notifier_ops); + return 0; +} + +struct fib_notifier_ops * +fib_notifier_ops_register(const struct fib_notifier_ops *tmpl, struct net *net) +{ + struct fib_notifier_ops *ops; + int err; + + ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL); + if (!ops) + return ERR_PTR(-ENOMEM); + + err = __fib_notifier_ops_register(ops, net); + if (err) + goto err_register; + + return ops; + +err_register: + kfree(ops); + return ERR_PTR(err); +} +EXPORT_SYMBOL(fib_notifier_ops_register); + +void fib_notifier_ops_unregister(struct fib_notifier_ops *ops) +{ + list_del_rcu(&ops->list); + kfree_rcu(ops, rcu); +} +EXPORT_SYMBOL(fib_notifier_ops_unregister); + +static int __net_init fib_notifier_net_init(struct net *net) +{ + INIT_LIST_HEAD(&net->fib_notifier_ops); + return 0; +} + +static struct pernet_operations fib_notifier_net_ops = { + .init = fib_notifier_net_init, +}; + +static int __init fib_notifier_init(void) +{ + return register_pernet_subsys(&fib_notifier_net_ops); +} + +subsys_initcall(fib_notifier_init); diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 044d2a159a3c..2cba559f14df 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -1247,22 +1247,28 @@ static int __net_init ip_fib_net_init(struct net *net) int err; size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; - net->ipv4.fib_seq = 0; + err = fib4_notifier_init(net); + if (err) + return err; /* Avoid false sharing : Use at least a full cache line */ size = max_t(size_t, size, L1_CACHE_BYTES); net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); - if (!net->ipv4.fib_table_hash) - return -ENOMEM; + if (!net->ipv4.fib_table_hash) { + err = -ENOMEM; + goto err_table_hash_alloc; + } err = fib4_rules_init(net); if (err < 0) - goto fail; + goto err_rules_init; return 0; -fail: +err_rules_init: kfree(net->ipv4.fib_table_hash); +err_table_hash_alloc: + fib4_notifier_exit(net); return err; } @@ -1292,6 +1298,7 @@ static void ip_fib_net_exit(struct net *net) #endif rtnl_unlock(); kfree(net->ipv4.fib_table_hash); + fib4_notifier_exit(net); } static int __net_init fib_net_init(struct net *net) diff --git a/net/ipv4/fib_notifier.c b/net/ipv4/fib_notifier.c index e0714d975947..7cf1954bbadc 100644 --- a/net/ipv4/fib_notifier.c +++ b/net/ipv4/fib_notifier.c @@ -1,86 +1,66 @@ #include #include -#include +#include #include #include +#include #include #include -static ATOMIC_NOTIFIER_HEAD(fib_chain); - -int call_fib_notifier(struct notifier_block *nb, struct net *net, - enum fib_event_type event_type, - struct fib_notifier_info *info) +int call_fib4_notifier(struct notifier_block *nb, struct net *net, + enum fib_event_type event_type, + struct fib_notifier_info *info) { - info->net = net; - return nb->notifier_call(nb, event_type, info); + info->family = AF_INET; + return call_fib_notifier(nb, net, event_type, info); } -int call_fib_notifiers(struct net *net, enum fib_event_type event_type, - struct fib_notifier_info *info) +int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, + struct fib_notifier_info *info) { + ASSERT_RTNL(); + + info->family = AF_INET; net->ipv4.fib_seq++; - info->net = net; - return atomic_notifier_call_chain(&fib_chain, event_type, info); + return call_fib_notifiers(net, event_type, info); } -static unsigned int fib_seq_sum(void) +static unsigned int fib4_seq_read(struct net *net) { - unsigned int fib_seq = 0; - struct net *net; + ASSERT_RTNL(); - rtnl_lock(); - for_each_net(net) - fib_seq += net->ipv4.fib_seq; - rtnl_unlock(); - - return fib_seq; + return net->ipv4.fib_seq; } -static bool fib_dump_is_consistent(struct notifier_block *nb, - void (*cb)(struct notifier_block *nb), - unsigned int fib_seq) +static int fib4_dump(struct net *net, struct notifier_block *nb) { - atomic_notifier_chain_register(&fib_chain, nb); - if (fib_seq == fib_seq_sum()) - return true; - atomic_notifier_chain_unregister(&fib_chain, nb); - if (cb) - cb(nb); - return false; + fib_rules_notify(net, nb); + fib_notify(net, nb); + + return 0; } -#define FIB_DUMP_MAX_RETRIES 5 -int register_fib_notifier(struct notifier_block *nb, - void (*cb)(struct notifier_block *nb)) -{ - int retries = 0; +static const struct fib_notifier_ops fib4_notifier_ops_template = { + .family = AF_INET, + .fib_seq_read = fib4_seq_read, + .fib_dump = fib4_dump, +}; - do { - unsigned int fib_seq = fib_seq_sum(); - struct net *net; +int __net_init fib4_notifier_init(struct net *net) +{ + struct fib_notifier_ops *ops; - /* Mutex semantics guarantee that every change done to - * FIB tries before we read the change sequence counter - * is now visible to us. - */ - rcu_read_lock(); - for_each_net_rcu(net) { - fib_rules_notify(net, nb); - fib_notify(net, nb); - } - rcu_read_unlock(); + net->ipv4.fib_seq = 0; - if (fib_dump_is_consistent(nb, cb, fib_seq)) - return 0; - } while (++retries < FIB_DUMP_MAX_RETRIES); + ops = fib_notifier_ops_register(&fib4_notifier_ops_template, net); + if (IS_ERR(ops)) + return PTR_ERR(ops); + net->ipv4.notifier_ops = ops; - return -EBUSY; + return 0; } -EXPORT_SYMBOL(register_fib_notifier); -int unregister_fib_notifier(struct notifier_block *nb) +void __net_exit fib4_notifier_exit(struct net *net) { - return atomic_notifier_chain_unregister(&fib_chain, nb); + fib_notifier_ops_unregister(net->ipv4.notifier_ops); } -EXPORT_SYMBOL(unregister_fib_notifier); diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c index 778ecf977eb2..acdbf5a24ac9 100644 --- a/net/ipv4/fib_rules.c +++ b/net/ipv4/fib_rules.c @@ -32,6 +32,7 @@ #include #include #include +#include struct fib4_rule { struct fib_rule common; @@ -193,7 +194,7 @@ static int call_fib_rule_notifier(struct notifier_block *nb, struct net *net, .rule = rule, }; - return call_fib_notifier(nb, net, event_type, &info.info); + return call_fib4_notifier(nb, net, event_type, &info.info); } static int call_fib_rule_notifiers(struct net *net, @@ -204,7 +205,7 @@ static int call_fib_rule_notifiers(struct net *net, .rule = rule, }; - return call_fib_notifiers(net, event_type, &info.info); + return call_fib4_notifiers(net, event_type, &info.info); } /* Called with rcu_read_lock() */ diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index f62dc2463280..632b454ce77c 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -44,6 +44,7 @@ #include #include #include +#include #include "fib_lookup.h" @@ -1451,14 +1452,14 @@ static int call_fib_nh_notifiers(struct fib_nh *fib_nh, if (IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && fib_nh->nh_flags & RTNH_F_LINKDOWN) break; - return call_fib_notifiers(dev_net(fib_nh->nh_dev), event_type, - &info.info); + return call_fib4_notifiers(dev_net(fib_nh->nh_dev), event_type, + &info.info); case FIB_EVENT_NH_DEL: if ((in_dev && IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && fib_nh->nh_flags & RTNH_F_LINKDOWN) || (fib_nh->nh_flags & RTNH_F_DEAD)) - return call_fib_notifiers(dev_net(fib_nh->nh_dev), - event_type, &info.info); + return call_fib4_notifiers(dev_net(fib_nh->nh_dev), + event_type, &info.info); default: break; } diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 64668c69dda6..1a6ffb0dab9c 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -81,6 +81,7 @@ #include #include #include +#include #include #include "fib_lookup.h" @@ -97,7 +98,7 @@ static int call_fib_entry_notifier(struct notifier_block *nb, struct net *net, .type = type, .tb_id = tb_id, }; - return call_fib_notifier(nb, net, event_type, &info.info); + return call_fib4_notifier(nb, net, event_type, &info.info); } static int call_fib_entry_notifiers(struct net *net, @@ -113,7 +114,7 @@ static int call_fib_entry_notifiers(struct net *net, .type = type, .tb_id = tb_id, }; - return call_fib_notifiers(net, event_type, &info.info); + return call_fib4_notifiers(net, event_type, &info.info); } #define MAX_STAT_DEPTH 32 -- 2.20.1