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netfilter: nf_tables: use new transaction infrastructure to handle chain
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This patch speeds up rule-set updates and it also introduces a way to
revert chain updates if the batch is aborted. The idea is to store the
changes in the transaction to apply that in the commit step.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Pablo Neira Ayuso committed May 19, 2014
1 parent ff3cd7b commit 91c7b38
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Showing 2 changed files with 175 additions and 45 deletions.
17 changes: 17 additions & 0 deletions include/net/netfilter/nf_tables.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -420,6 +420,22 @@ struct nft_trans_set {
#define nft_trans_set_id(trans) \
(((struct nft_trans_set *)trans->data)->set_id)

struct nft_trans_chain {
bool update;
char name[NFT_CHAIN_MAXNAMELEN];
struct nft_stats __percpu *stats;
u8 policy;
};

#define nft_trans_chain_update(trans) \
(((struct nft_trans_chain *)trans->data)->update)
#define nft_trans_chain_name(trans) \
(((struct nft_trans_chain *)trans->data)->name)
#define nft_trans_chain_stats(trans) \
(((struct nft_trans_chain *)trans->data)->stats)
#define nft_trans_chain_policy(trans) \
(((struct nft_trans_chain *)trans->data)->policy)

static inline struct nft_expr *nft_expr_first(const struct nft_rule *rule)
{
return (struct nft_expr *)&rule->data[0];
Expand Down Expand Up @@ -452,6 +468,7 @@ static inline void *nft_userdata(const struct nft_rule *rule)

enum nft_chain_flags {
NFT_BASE_CHAIN = 0x1,
NFT_CHAIN_INACTIVE = 0x2,
};

/**
Expand Down
203 changes: 158 additions & 45 deletions net/netfilter/nf_tables_api.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -782,6 +782,8 @@ static int nf_tables_getchain(struct sock *nlsk, struct sk_buff *skb,
chain = nf_tables_chain_lookup(table, nla[NFTA_CHAIN_NAME]);
if (IS_ERR(chain))
return PTR_ERR(chain);
if (chain->flags & NFT_CHAIN_INACTIVE)
return -ENOENT;

skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb2)
Expand Down Expand Up @@ -847,6 +849,34 @@ static void nft_chain_stats_replace(struct nft_base_chain *chain,
rcu_assign_pointer(chain->stats, newstats);
}

static int nft_trans_chain_add(struct nft_ctx *ctx, int msg_type)
{
struct nft_trans *trans;

trans = nft_trans_alloc(ctx, msg_type, sizeof(struct nft_trans_chain));
if (trans == NULL)
return -ENOMEM;

if (msg_type == NFT_MSG_NEWCHAIN)
ctx->chain->flags |= NFT_CHAIN_INACTIVE;

list_add_tail(&trans->list, &ctx->net->nft.commit_list);
return 0;
}

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));
} else {
kfree(chain);
}
}

static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
const struct nlmsghdr *nlh,
const struct nlattr * const nla[])
Expand All @@ -866,6 +896,7 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
struct nft_stats __percpu *stats;
int err;
bool create;
struct nft_ctx ctx;

create = nlh->nlmsg_flags & NLM_F_CREATE ? true : false;

Expand Down Expand Up @@ -911,6 +942,11 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
}

if (chain != NULL) {
struct nft_stats *stats = NULL;
struct nft_trans *trans;

if (chain->flags & NFT_CHAIN_INACTIVE)
return -ENOENT;
if (nlh->nlmsg_flags & NLM_F_EXCL)
return -EEXIST;
if (nlh->nlmsg_flags & NLM_F_REPLACE)
Expand All @@ -927,17 +963,28 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
stats = nft_stats_alloc(nla[NFTA_CHAIN_COUNTERS]);
if (IS_ERR(stats))
return PTR_ERR(stats);

nft_chain_stats_replace(nft_base_chain(chain), stats);
}

if (nla[NFTA_CHAIN_POLICY])
nft_base_chain(chain)->policy = policy;
nft_ctx_init(&ctx, skb, nlh, afi, table, chain, nla);
trans = nft_trans_alloc(&ctx, NFT_MSG_NEWCHAIN,
sizeof(struct nft_trans_chain));
if (trans == NULL)
return -ENOMEM;

if (nla[NFTA_CHAIN_HANDLE] && name)
nla_strlcpy(chain->name, name, NFT_CHAIN_MAXNAMELEN);
nft_trans_chain_stats(trans) = stats;
nft_trans_chain_update(trans) = true;

goto notify;
if (nla[NFTA_CHAIN_POLICY])
nft_trans_chain_policy(trans) = policy;
else
nft_trans_chain_policy(trans) = -1;

if (nla[NFTA_CHAIN_HANDLE] && name) {
nla_strlcpy(nft_trans_chain_name(trans), name,
NFT_CHAIN_MAXNAMELEN);
}
list_add_tail(&trans->list, &net->nft.commit_list);
return 0;
}

if (table->use == UINT_MAX)
Expand Down Expand Up @@ -1033,31 +1080,26 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
if (!(table->flags & NFT_TABLE_F_DORMANT) &&
chain->flags & NFT_BASE_CHAIN) {
err = nf_register_hooks(nft_base_chain(chain)->ops, afi->nops);
if (err < 0) {
module_put(basechain->type->owner);
free_percpu(basechain->stats);
kfree(basechain);
return err;
}
if (err < 0)
goto err1;
}
list_add_tail(&chain->list, &table->chains);
table->use++;
notify:
nf_tables_chain_notify(skb, nlh, table, chain, NFT_MSG_NEWCHAIN,
family);
return 0;
}

static void nf_tables_chain_destroy(struct nft_chain *chain)
{
BUG_ON(chain->use > 0);
nft_ctx_init(&ctx, skb, nlh, afi, table, chain, nla);
err = nft_trans_chain_add(&ctx, NFT_MSG_NEWCHAIN);
if (err < 0)
goto err2;

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));
} else
kfree(chain);
list_add_tail(&chain->list, &table->chains);
return 0;
err2:
if (!(table->flags & NFT_TABLE_F_DORMANT) &&
chain->flags & NFT_BASE_CHAIN) {
nf_unregister_hooks(nft_base_chain(chain)->ops,
afi->nops);
}
err1:
nf_tables_chain_destroy(chain);
return err;
}

static int nf_tables_delchain(struct sock *nlsk, struct sk_buff *skb,
Expand All @@ -1070,6 +1112,8 @@ static int nf_tables_delchain(struct sock *nlsk, struct sk_buff *skb,
struct nft_chain *chain;
struct net *net = sock_net(skb->sk);
int family = nfmsg->nfgen_family;
struct nft_ctx ctx;
int err;

afi = nf_tables_afinfo_lookup(net, family, false);
if (IS_ERR(afi))
Expand All @@ -1082,24 +1126,17 @@ static int nf_tables_delchain(struct sock *nlsk, struct sk_buff *skb,
chain = nf_tables_chain_lookup(table, nla[NFTA_CHAIN_NAME]);
if (IS_ERR(chain))
return PTR_ERR(chain);

if (chain->flags & NFT_CHAIN_INACTIVE)
return -ENOENT;
if (!list_empty(&chain->rules) || chain->use > 0)
return -EBUSY;

list_del(&chain->list);
table->use--;

if (!(table->flags & NFT_TABLE_F_DORMANT) &&
chain->flags & NFT_BASE_CHAIN)
nf_unregister_hooks(nft_base_chain(chain)->ops, afi->nops);

nf_tables_chain_notify(skb, nlh, table, chain, NFT_MSG_DELCHAIN,
family);

/* Make sure all rule references are gone before this is released */
synchronize_rcu();
nft_ctx_init(&ctx, skb, nlh, afi, table, chain, nla);
err = nft_trans_chain_add(&ctx, NFT_MSG_DELCHAIN);
if (err < 0)
return err;

nf_tables_chain_destroy(chain);
list_del(&chain->list);
return 0;
}

Expand Down Expand Up @@ -1542,6 +1579,8 @@ static int nf_tables_getrule(struct sock *nlsk, struct sk_buff *skb,
chain = nf_tables_chain_lookup(table, nla[NFTA_RULE_CHAIN]);
if (IS_ERR(chain))
return PTR_ERR(chain);
if (chain->flags & NFT_CHAIN_INACTIVE)
return -ENOENT;

rule = nf_tables_rule_lookup(chain, nla[NFTA_RULE_HANDLE]);
if (IS_ERR(rule))
Expand Down Expand Up @@ -3109,7 +3148,7 @@ static const struct nfnl_callback nf_tables_cb[NFT_MSG_MAX] = {
.policy = nft_table_policy,
},
[NFT_MSG_NEWCHAIN] = {
.call = nf_tables_newchain,
.call_batch = nf_tables_newchain,
.attr_count = NFTA_CHAIN_MAX,
.policy = nft_chain_policy,
},
Expand All @@ -3119,7 +3158,7 @@ static const struct nfnl_callback nf_tables_cb[NFT_MSG_MAX] = {
.policy = nft_chain_policy,
},
[NFT_MSG_DELCHAIN] = {
.call = nf_tables_delchain,
.call_batch = nf_tables_delchain,
.attr_count = NFTA_CHAIN_MAX,
.policy = nft_chain_policy,
},
Expand Down Expand Up @@ -3170,6 +3209,27 @@ static const struct nfnl_callback nf_tables_cb[NFT_MSG_MAX] = {
},
};

static void nft_chain_commit_update(struct nft_trans *trans)
{
struct nft_base_chain *basechain;

if (nft_trans_chain_name(trans)[0])
strcpy(trans->ctx.chain->name, nft_trans_chain_name(trans));

if (!(trans->ctx.chain->flags & NFT_BASE_CHAIN))
return;

basechain = nft_base_chain(trans->ctx.chain);
nft_chain_stats_replace(basechain, nft_trans_chain_stats(trans));

switch (nft_trans_chain_policy(trans)) {
case NF_DROP:
case NF_ACCEPT:
basechain->policy = nft_trans_chain_policy(trans);
break;
}
}

static int nf_tables_commit(struct sk_buff *skb)
{
struct net *net = sock_net(skb->sk);
Expand All @@ -3188,6 +3248,33 @@ static int nf_tables_commit(struct sk_buff *skb)

list_for_each_entry_safe(trans, next, &net->nft.commit_list, list) {
switch (trans->msg_type) {
case NFT_MSG_NEWCHAIN:
if (nft_trans_chain_update(trans))
nft_chain_commit_update(trans);
else {
trans->ctx.chain->flags &= ~NFT_CHAIN_INACTIVE;
trans->ctx.table->use++;
}
nf_tables_chain_notify(trans->ctx.skb, trans->ctx.nlh,
trans->ctx.table,
trans->ctx.chain,
NFT_MSG_NEWCHAIN,
trans->ctx.afi->family);
nft_trans_destroy(trans);
break;
case NFT_MSG_DELCHAIN:
trans->ctx.table->use--;
nf_tables_chain_notify(trans->ctx.skb, trans->ctx.nlh,
trans->ctx.table,
trans->ctx.chain,
NFT_MSG_DELCHAIN,
trans->ctx.afi->family);
if (!(trans->ctx.table->flags & NFT_TABLE_F_DORMANT) &&
trans->ctx.chain->flags & NFT_BASE_CHAIN) {
nf_unregister_hooks(nft_base_chain(trans->ctx.chain)->ops,
trans->ctx.afi->nops);
}
break;
case NFT_MSG_NEWRULE:
nft_rule_clear(trans->ctx.net, nft_trans_rule(trans));
nf_tables_rule_notify(trans->ctx.skb, trans->ctx.nlh,
Expand Down Expand Up @@ -3225,6 +3312,9 @@ static int nf_tables_commit(struct sk_buff *skb)
/* Now we can safely release unused old rules */
list_for_each_entry_safe(trans, next, &net->nft.commit_list, list) {
switch (trans->msg_type) {
case NFT_MSG_DELCHAIN:
nf_tables_chain_destroy(trans->ctx.chain);
break;
case NFT_MSG_DELRULE:
nf_tables_rule_destroy(&trans->ctx,
nft_trans_rule(trans));
Expand All @@ -3246,6 +3336,26 @@ static int nf_tables_abort(struct sk_buff *skb)

list_for_each_entry_safe(trans, next, &net->nft.commit_list, list) {
switch (trans->msg_type) {
case NFT_MSG_NEWCHAIN:
if (nft_trans_chain_update(trans)) {
if (nft_trans_chain_stats(trans))
free_percpu(nft_trans_chain_stats(trans));

nft_trans_destroy(trans);
} else {
list_del(&trans->ctx.chain->list);
if (!(trans->ctx.table->flags & NFT_TABLE_F_DORMANT) &&
trans->ctx.chain->flags & NFT_BASE_CHAIN) {
nf_unregister_hooks(nft_base_chain(trans->ctx.chain)->ops,
trans->ctx.afi->nops);
}
}
break;
case NFT_MSG_DELCHAIN:
list_add_tail(&trans->ctx.chain->list,
&trans->ctx.table->chains);
nft_trans_destroy(trans);
break;
case NFT_MSG_NEWRULE:
list_del_rcu(&nft_trans_rule(trans)->list);
break;
Expand All @@ -3269,6 +3379,9 @@ static int nf_tables_abort(struct sk_buff *skb)

list_for_each_entry_safe(trans, next, &net->nft.commit_list, list) {
switch (trans->msg_type) {
case NFT_MSG_NEWCHAIN:
nf_tables_chain_destroy(trans->ctx.chain);
break;
case NFT_MSG_NEWRULE:
nf_tables_rule_destroy(&trans->ctx,
nft_trans_rule(trans));
Expand Down

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