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Commit 2cbce139 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: nf_tables: attach net_device to basechain 



The device is part of the hook configuration, so instead of a global
configuration per table, set it to each of the basechain that we create.

This patch reworks ebddf1a8 ("netfilter: nf_tables: allow to bind table to
net_device").

Note that this adds a dev_name field in the nft_base_chain structure which is
required the netdev notification subscription that follows up in a patch to
handle gone net_devices.

Suggested-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 711bdde6

include/net/netfilter/nf_tables.h

+2 −2
Original line number Diff line number Diff line
@@ -791,6 +791,7 @@ struct nft_stats { 
 *	@policy: default policy

 *	@stats: per-cpu chain stats

 *	@chain: the chain

 *	@dev_name: device name that this base chain is attached to (if any)

 */

struct nft_base_chain {

	struct nf_hook_ops		ops[NFT_HOOK_OPS_MAX];
@@ -799,6 +800,7 @@ struct nft_base_chain { 
	u8				policy;

	struct nft_stats __percpu	*stats;

	struct nft_chain		chain;

	char 				dev_name[IFNAMSIZ];

};



static inline struct nft_base_chain *nft_base_chain(const struct nft_chain *chain)
@@ -819,7 +821,6 @@ unsigned int nft_do_chain(struct nft_pktinfo *pkt, 
 *	@use: number of chain references to this table

 *	@flags: table flag (see enum nft_table_flags)

 *	@name: name of the table

 *	@dev: this table is bound to this device (if any)

 */

struct nft_table {

	struct list_head		list;
@@ -829,7 +830,6 @@ struct nft_table { 
	u32				use;

	u16				flags;

	char				name[NFT_TABLE_MAXNAMELEN];

	struct net_device		*dev;

};



enum nft_af_flags {

include/uapi/linux/netfilter/nf_tables.h

+2 −2
Original line number Diff line number Diff line
@@ -122,11 +122,13 @@ enum nft_list_attributes { 
 *

 * @NFTA_HOOK_HOOKNUM: netfilter hook number (NLA_U32)

 * @NFTA_HOOK_PRIORITY: netfilter hook priority (NLA_U32)

 * @NFTA_HOOK_DEV: netdevice name (NLA_STRING)

 */

enum nft_hook_attributes {

	NFTA_HOOK_UNSPEC,

	NFTA_HOOK_HOOKNUM,

	NFTA_HOOK_PRIORITY,

	NFTA_HOOK_DEV,

	__NFTA_HOOK_MAX

};

#define NFTA_HOOK_MAX		(__NFTA_HOOK_MAX - 1)
@@ -146,14 +148,12 @@ enum nft_table_flags { 
 * @NFTA_TABLE_NAME: name of the table (NLA_STRING)

 * @NFTA_TABLE_FLAGS: bitmask of enum nft_table_flags (NLA_U32)

 * @NFTA_TABLE_USE: number of chains in this table (NLA_U32)

 * @NFTA_TABLE_DEV: net device name (NLA_STRING)

 */

enum nft_table_attributes {

	NFTA_TABLE_UNSPEC,

	NFTA_TABLE_NAME,

	NFTA_TABLE_FLAGS,

	NFTA_TABLE_USE,

	NFTA_TABLE_DEV,

	__NFTA_TABLE_MAX

};

#define NFTA_TABLE_MAX		(__NFTA_TABLE_MAX - 1)

net/netfilter/nf_tables_api.c

+42 −37
Original line number Diff line number Diff line
@@ -399,8 +399,6 @@ static const struct nla_policy nft_table_policy[NFTA_TABLE_MAX + 1] = { 
	[NFTA_TABLE_NAME]	= { .type = NLA_STRING,

				    .len = NFT_TABLE_MAXNAMELEN - 1 },

	[NFTA_TABLE_FLAGS]	= { .type = NLA_U32 },

	[NFTA_TABLE_DEV]	= { .type = NLA_STRING,

				    .len = IFNAMSIZ - 1 },

};



static int nf_tables_fill_table_info(struct sk_buff *skb, struct net *net,
@@ -425,10 +423,6 @@ static int nf_tables_fill_table_info(struct sk_buff *skb, struct net *net, 
	    nla_put_be32(skb, NFTA_TABLE_USE, htonl(table->use)))

		goto nla_put_failure;



	if (table->dev &&

	    nla_put_string(skb, NFTA_TABLE_DEV, table->dev->name))

		goto nla_put_failure;



	nlmsg_end(skb, nlh);

	return 0;
@@ -614,11 +608,6 @@ static int nf_tables_updtable(struct nft_ctx *ctx) 
	if (flags == ctx->table->flags)

		return 0;



	if ((ctx->afi->flags & NFT_AF_NEEDS_DEV) &&

	    ctx->nla[NFTA_TABLE_DEV] &&

	    nla_strcmp(ctx->nla[NFTA_TABLE_DEV], ctx->table->dev->name))

		return -EOPNOTSUPP;



	trans = nft_trans_alloc(ctx, NFT_MSG_NEWTABLE,

				sizeof(struct nft_trans_table));

	if (trans == NULL)
@@ -656,7 +645,6 @@ static int nf_tables_newtable(struct sock *nlsk, struct sk_buff *skb, 
	struct nft_table *table;

	struct net *net = sock_net(skb->sk);

	int family = nfmsg->nfgen_family;

	struct net_device *dev = NULL;

	u32 flags = 0;

	struct nft_ctx ctx;

	int err;
@@ -691,20 +679,6 @@ static int nf_tables_newtable(struct sock *nlsk, struct sk_buff *skb, 
			return -EINVAL;

	}



	if (afi->flags & NFT_AF_NEEDS_DEV) {

		char ifname[IFNAMSIZ];



		if (!nla[NFTA_TABLE_DEV])

			return -EOPNOTSUPP;



		nla_strlcpy(ifname, nla[NFTA_TABLE_DEV], IFNAMSIZ);

		dev = dev_get_by_name(net, ifname);

		if (!dev)

			return -ENOENT;

	} else if (nla[NFTA_TABLE_DEV]) {

		return -EOPNOTSUPP;

	}



	err = -EAFNOSUPPORT;

	if (!try_module_get(afi->owner))

		goto err1;
@@ -718,7 +692,6 @@ static int nf_tables_newtable(struct sock *nlsk, struct sk_buff *skb, 
	INIT_LIST_HEAD(&table->chains);

	INIT_LIST_HEAD(&table->sets);

	table->flags = flags;

	table->dev   = dev;



	nft_ctx_init(&ctx, skb, nlh, afi, table, NULL, nla);

	err = nft_trans_table_add(&ctx, NFT_MSG_NEWTABLE);
@@ -732,9 +705,6 @@ static int nf_tables_newtable(struct sock *nlsk, struct sk_buff *skb, 
err2:

	module_put(afi->owner);

err1:

	if (dev != NULL)

		dev_put(dev);



	return err;

}
@@ -838,9 +808,6 @@ static void nf_tables_table_destroy(struct nft_ctx *ctx) 
{

	BUG_ON(ctx->table->use > 0);



	if (ctx->table->dev)

		dev_put(ctx->table->dev);



	kfree(ctx->table);

	module_put(ctx->afi->owner);

}
@@ -916,6 +883,8 @@ static const struct nla_policy nft_chain_policy[NFTA_CHAIN_MAX + 1] = { 
static const struct nla_policy nft_hook_policy[NFTA_HOOK_MAX + 1] = {

	[NFTA_HOOK_HOOKNUM]	= { .type = NLA_U32 },

	[NFTA_HOOK_PRIORITY]	= { .type = NLA_U32 },

	[NFTA_HOOK_DEV]		= { .type = NLA_STRING,

				    .len = IFNAMSIZ - 1 },

};



static int nft_dump_stats(struct sk_buff *skb, struct nft_stats __percpu *stats)
@@ -989,6 +958,9 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net, 
			goto nla_put_failure;

		if (nla_put_be32(skb, NFTA_HOOK_PRIORITY, htonl(ops->priority)))

			goto nla_put_failure;

		if (basechain->dev_name[0] &&

		    nla_put_string(skb, NFTA_HOOK_DEV, basechain->dev_name))

			goto nla_put_failure;

		nla_nest_end(skb, nest);



		if (nla_put_be32(skb, NFTA_CHAIN_POLICY,
@@ -1200,9 +1172,13 @@ static void nf_tables_chain_destroy(struct nft_chain *chain) 
	BUG_ON(chain->use > 0);



	if (chain->flags & NFT_BASE_CHAIN) {

		module_put(nft_base_chain(chain)->type->owner);

		free_percpu(nft_base_chain(chain)->stats);

		kfree(nft_base_chain(chain));

		struct nft_base_chain *basechain = nft_base_chain(chain);



		module_put(basechain->type->owner);

		free_percpu(basechain->stats);

		if (basechain->ops[0].dev != NULL)

			dev_put(basechain->ops[0].dev);

		kfree(basechain);

	} else {

		kfree(chain);

	}
@@ -1221,6 +1197,7 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb, 
	struct nlattr *ha[NFTA_HOOK_MAX + 1];

	struct net *net = sock_net(skb->sk);

	int family = nfmsg->nfgen_family;

	struct net_device *dev = NULL;

	u8 policy = NF_ACCEPT;

	u64 handle = 0;

	unsigned int i;
@@ -1360,17 +1337,43 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb, 
			return -ENOENT;

		hookfn = type->hooks[hooknum];



		if (afi->flags & NFT_AF_NEEDS_DEV) {

			char ifname[IFNAMSIZ];



			if (!ha[NFTA_HOOK_DEV]) {

				module_put(type->owner);

				return -EOPNOTSUPP;

			}



			nla_strlcpy(ifname, ha[NFTA_HOOK_DEV], IFNAMSIZ);

			dev = dev_get_by_name(net, ifname);

			if (!dev) {

				module_put(type->owner);

				return -ENOENT;

			}

		} else if (ha[NFTA_HOOK_DEV]) {

			module_put(type->owner);

			return -EOPNOTSUPP;

		}



		basechain = kzalloc(sizeof(*basechain), GFP_KERNEL);

		if (basechain == NULL) {

			module_put(type->owner);

			if (dev != NULL)

				dev_put(dev);

			return -ENOMEM;

		}



		if (dev != NULL)

			strncpy(basechain->dev_name, dev->name, IFNAMSIZ);



		if (nla[NFTA_CHAIN_COUNTERS]) {

			stats = nft_stats_alloc(nla[NFTA_CHAIN_COUNTERS]);

			if (IS_ERR(stats)) {

				module_put(type->owner);

				kfree(basechain);

				if (dev != NULL)

					dev_put(dev);

				return PTR_ERR(stats);

			}

			basechain->stats = stats;
@@ -1379,6 +1382,8 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb, 
			if (stats == NULL) {

				module_put(type->owner);

				kfree(basechain);

				if (dev != NULL)

					dev_put(dev);

				return -ENOMEM;

			}

			rcu_assign_pointer(basechain->stats, stats);
@@ -1396,7 +1401,7 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb, 
			ops->priority	= priority;

			ops->priv	= chain;

			ops->hook	= afi->hooks[ops->hooknum];

			ops->dev	= table->dev;

			ops->dev	= dev;

			if (hookfn)

				ops->hook = hookfn;

			if (afi->hook_ops_init)