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author | Pablo Neira Ayuso <pablo@netfilter.org> | 2015-06-15 12:12:01 +0200 |
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committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2015-06-15 23:02:35 +0200 |
commit | 835b803377f5f11f9ccf234f70ed667a82605c45 (patch) | |
tree | c37020898a8d31211877daef0fc7609bc118c878 /net/netfilter | |
parent | d8ee8f7c56b267751f95a1f0b4a75618909c07ac (diff) | |
download | linux-stable-835b803377f5f11f9ccf234f70ed667a82605c45.tar.gz linux-stable-835b803377f5f11f9ccf234f70ed667a82605c45.tar.bz2 linux-stable-835b803377f5f11f9ccf234f70ed667a82605c45.zip |
netfilter: nf_tables_netdev: unregister hooks on net_device removal
In case the net_device is gone, we have to unregister the hooks and put back
the reference on the net_device object. Once it comes back, register them
again. This also covers the device rename case.
This patch also adds a new flag to indicate that the basechain is disabled, so
their hooks are not registered. This flag is used by the netdev family to
handle the case where the net_device object is gone. Currently this flag is not
exposed to userspace.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter')
-rw-r--r-- | net/netfilter/nf_tables_api.c | 16 | ||||
-rw-r--r-- | net/netfilter/nf_tables_netdev.c | 75 |
2 files changed, 87 insertions, 4 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index c66dc62afb46..cfe636808541 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -127,17 +127,25 @@ static void nft_trans_destroy(struct nft_trans *trans) kfree(trans); } -static int nft_register_basechain(struct nft_base_chain *basechain, - unsigned int hook_nops) +int nft_register_basechain(struct nft_base_chain *basechain, + unsigned int hook_nops) { + if (basechain->flags & NFT_BASECHAIN_DISABLED) + return 0; + return nf_register_hooks(basechain->ops, hook_nops); } +EXPORT_SYMBOL_GPL(nft_register_basechain); -static void nft_unregister_basechain(struct nft_base_chain *basechain, - unsigned int hook_nops) +void nft_unregister_basechain(struct nft_base_chain *basechain, + unsigned int hook_nops) { + if (basechain->flags & NFT_BASECHAIN_DISABLED) + return; + nf_unregister_hooks(basechain->ops, hook_nops); } +EXPORT_SYMBOL_GPL(nft_unregister_basechain); static int nf_tables_register_hooks(const struct nft_table *table, struct nft_chain *chain, diff --git a/net/netfilter/nf_tables_netdev.c b/net/netfilter/nf_tables_netdev.c index 04cb17057f46..2cae4d4a03b7 100644 --- a/net/netfilter/nf_tables_netdev.c +++ b/net/netfilter/nf_tables_netdev.c @@ -8,6 +8,7 @@ #include <linux/init.h> #include <linux/module.h> +#include <linux/netdevice.h> #include <net/netfilter/nf_tables.h> #include <linux/ip.h> #include <linux/ipv6.h> @@ -157,6 +158,77 @@ static const struct nf_chain_type nft_filter_chain_netdev = { .hook_mask = (1 << NF_NETDEV_INGRESS), }; +static void nft_netdev_event(unsigned long event, struct nft_af_info *afi, + struct net_device *dev, struct nft_table *table, + struct nft_base_chain *basechain) +{ + switch (event) { + case NETDEV_REGISTER: + if (strcmp(basechain->dev_name, dev->name) != 0) + return; + + BUG_ON(!(basechain->flags & NFT_BASECHAIN_DISABLED)); + + dev_hold(dev); + basechain->ops[0].dev = dev; + basechain->flags &= ~NFT_BASECHAIN_DISABLED; + if (!(table->flags & NFT_TABLE_F_DORMANT)) + nft_register_basechain(basechain, afi->nops); + break; + case NETDEV_UNREGISTER: + if (strcmp(basechain->dev_name, dev->name) != 0) + return; + + BUG_ON(basechain->flags & NFT_BASECHAIN_DISABLED); + + if (!(table->flags & NFT_TABLE_F_DORMANT)) + nft_unregister_basechain(basechain, afi->nops); + + dev_put(basechain->ops[0].dev); + basechain->ops[0].dev = NULL; + basechain->flags |= NFT_BASECHAIN_DISABLED; + break; + case NETDEV_CHANGENAME: + if (dev->ifindex != basechain->ops[0].dev->ifindex) + return; + + strncpy(basechain->dev_name, dev->name, IFNAMSIZ); + break; + } +} + +static int nf_tables_netdev_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct nft_af_info *afi; + struct nft_table *table; + struct nft_chain *chain; + + nfnl_lock(NFNL_SUBSYS_NFTABLES); + list_for_each_entry(afi, &dev_net(dev)->nft.af_info, list) { + if (afi->family != NFPROTO_NETDEV) + continue; + + list_for_each_entry(table, &afi->tables, list) { + list_for_each_entry(chain, &table->chains, list) { + if (!(chain->flags & NFT_BASE_CHAIN)) + continue; + + nft_netdev_event(event, afi, dev, table, + nft_base_chain(chain)); + } + } + } + nfnl_unlock(NFNL_SUBSYS_NFTABLES); + + return NOTIFY_DONE; +} + +static struct notifier_block nf_tables_netdev_notifier = { + .notifier_call = nf_tables_netdev_event, +}; + static int __init nf_tables_netdev_init(void) { int ret; @@ -166,11 +238,14 @@ static int __init nf_tables_netdev_init(void) if (ret < 0) nft_unregister_chain_type(&nft_filter_chain_netdev); + register_netdevice_notifier(&nf_tables_netdev_notifier); + return ret; } static void __exit nf_tables_netdev_exit(void) { + unregister_netdevice_notifier(&nf_tables_netdev_notifier); unregister_pernet_subsys(&nf_tables_netdev_net_ops); nft_unregister_chain_type(&nft_filter_chain_netdev); } |