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Diffstat (limited to 'net/netfilter/nf_tables_api.c')
-rw-r--r--net/netfilter/nf_tables_api.c202
1 files changed, 184 insertions, 18 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 0f140663ec71..79e1418a6043 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -978,6 +978,7 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb,
INIT_LIST_HEAD(&chain->rules);
chain->handle = nf_tables_alloc_handle(table);
+ chain->net = net;
nla_strlcpy(chain->name, name, NFT_CHAIN_MAXNAMELEN);
if (!(table->flags & NFT_TABLE_F_DORMANT) &&
@@ -1371,6 +1372,41 @@ err:
return err;
}
+static inline bool
+nft_rule_is_active(struct net *net, const struct nft_rule *rule)
+{
+ return (rule->genmask & (1 << net->nft.gencursor)) == 0;
+}
+
+static inline int gencursor_next(struct net *net)
+{
+ return net->nft.gencursor+1 == 1 ? 1 : 0;
+}
+
+static inline int
+nft_rule_is_active_next(struct net *net, const struct nft_rule *rule)
+{
+ return (rule->genmask & (1 << gencursor_next(net))) == 0;
+}
+
+static inline void
+nft_rule_activate_next(struct net *net, struct nft_rule *rule)
+{
+ /* Now inactive, will be active in the future */
+ rule->genmask = (1 << net->nft.gencursor);
+}
+
+static inline void
+nft_rule_disactivate_next(struct net *net, struct nft_rule *rule)
+{
+ rule->genmask = (1 << gencursor_next(net));
+}
+
+static inline void nft_rule_clear(struct net *net, struct nft_rule *rule)
+{
+ rule->genmask = 0;
+}
+
static int nf_tables_dump_rules(struct sk_buff *skb,
struct netlink_callback *cb)
{
@@ -1382,6 +1418,8 @@ static int nf_tables_dump_rules(struct sk_buff *skb,
unsigned int idx = 0, s_idx = cb->args[0];
struct net *net = sock_net(skb->sk);
int family = nfmsg->nfgen_family;
+ u8 genctr = ACCESS_ONCE(net->nft.genctr);
+ u8 gencursor = ACCESS_ONCE(net->nft.gencursor);
list_for_each_entry(afi, &net->nft.af_info, list) {
if (family != NFPROTO_UNSPEC && family != afi->family)
@@ -1390,6 +1428,8 @@ static int nf_tables_dump_rules(struct sk_buff *skb,
list_for_each_entry(table, &afi->tables, list) {
list_for_each_entry(chain, &table->chains, list) {
list_for_each_entry(rule, &chain->rules, list) {
+ if (!nft_rule_is_active(net, rule))
+ goto cont;
if (idx < s_idx)
goto cont;
if (idx > s_idx)
@@ -1408,6 +1448,10 @@ cont:
}
}
done:
+ /* Invalidate this dump, a transition to the new generation happened */
+ if (gencursor != net->nft.gencursor || genctr != net->nft.genctr)
+ return -EBUSY;
+
cb->args[0] = idx;
return skb->len;
}
@@ -1492,6 +1536,25 @@ static void nf_tables_rule_destroy(struct nft_rule *rule)
static struct nft_expr_info *info;
+static struct nft_rule_trans *
+nf_tables_trans_add(struct nft_rule *rule, const struct nft_ctx *ctx)
+{
+ struct nft_rule_trans *rupd;
+
+ rupd = kmalloc(sizeof(struct nft_rule_trans), GFP_KERNEL);
+ if (rupd == NULL)
+ return NULL;
+
+ rupd->chain = ctx->chain;
+ rupd->table = ctx->table;
+ rupd->rule = rule;
+ rupd->family = ctx->afi->family;
+ rupd->nlh = ctx->nlh;
+ list_add_tail(&rupd->list, &ctx->net->nft.commit_list);
+
+ return rupd;
+}
+
static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
const struct nlmsghdr *nlh,
const struct nlattr * const nla[])
@@ -1502,6 +1565,7 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
struct nft_table *table;
struct nft_chain *chain;
struct nft_rule *rule, *old_rule = NULL;
+ struct nft_rule_trans *repl = NULL;
struct nft_expr *expr;
struct nft_ctx ctx;
struct nlattr *tmp;
@@ -1576,6 +1640,8 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
if (rule == NULL)
goto err1;
+ nft_rule_activate_next(net, rule);
+
rule->handle = handle;
rule->dlen = size;
@@ -1589,8 +1655,18 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
}
if (nlh->nlmsg_flags & NLM_F_REPLACE) {
- list_replace_rcu(&old_rule->list, &rule->list);
- nf_tables_rule_destroy(old_rule);
+ if (nft_rule_is_active_next(net, old_rule)) {
+ repl = nf_tables_trans_add(old_rule, &ctx);
+ if (repl == NULL) {
+ err = -ENOMEM;
+ goto err2;
+ }
+ nft_rule_disactivate_next(net, old_rule);
+ list_add_tail(&rule->list, &old_rule->list);
+ } else {
+ err = -ENOENT;
+ goto err2;
+ }
} else if (nlh->nlmsg_flags & NLM_F_APPEND)
if (old_rule)
list_add_rcu(&rule->list, &old_rule->list);
@@ -1603,11 +1679,20 @@ static int nf_tables_newrule(struct sock *nlsk, struct sk_buff *skb,
list_add_rcu(&rule->list, &chain->rules);
}
- nf_tables_rule_notify(skb, nlh, table, chain, rule, NFT_MSG_NEWRULE,
- nlh->nlmsg_flags & (NLM_F_APPEND | NLM_F_REPLACE),
- nfmsg->nfgen_family);
+ if (nf_tables_trans_add(rule, &ctx) == NULL) {
+ err = -ENOMEM;
+ goto err3;
+ }
return 0;
+err3:
+ list_del_rcu(&rule->list);
+ if (repl) {
+ list_del_rcu(&repl->rule->list);
+ list_del(&repl->list);
+ nft_rule_clear(net, repl->rule);
+ kfree(repl);
+ }
err2:
nf_tables_rule_destroy(rule);
err1:
@@ -1618,6 +1703,19 @@ err1:
return err;
}
+static int
+nf_tables_delrule_one(struct nft_ctx *ctx, struct nft_rule *rule)
+{
+ /* You cannot delete the same rule twice */
+ if (nft_rule_is_active_next(ctx->net, rule)) {
+ if (nf_tables_trans_add(rule, ctx) == NULL)
+ return -ENOMEM;
+ nft_rule_disactivate_next(ctx->net, rule);
+ return 0;
+ }
+ return -ENOENT;
+}
+
static int nf_tables_delrule(struct sock *nlsk, struct sk_buff *skb,
const struct nlmsghdr *nlh,
const struct nlattr * const nla[])
@@ -1628,7 +1726,8 @@ static int nf_tables_delrule(struct sock *nlsk, struct sk_buff *skb,
const struct nft_table *table;
struct nft_chain *chain;
struct nft_rule *rule, *tmp;
- int family = nfmsg->nfgen_family;
+ int family = nfmsg->nfgen_family, err = 0;
+ struct nft_ctx ctx;
afi = nf_tables_afinfo_lookup(net, family, false);
if (IS_ERR(afi))
@@ -1642,31 +1741,95 @@ static int nf_tables_delrule(struct sock *nlsk, struct sk_buff *skb,
if (IS_ERR(chain))
return PTR_ERR(chain);
+ nft_ctx_init(&ctx, skb, nlh, afi, table, chain, nla);
+
if (nla[NFTA_RULE_HANDLE]) {
rule = nf_tables_rule_lookup(chain, nla[NFTA_RULE_HANDLE]);
if (IS_ERR(rule))
return PTR_ERR(rule);
- /* List removal must be visible before destroying expressions */
- list_del_rcu(&rule->list);
-
- nf_tables_rule_notify(skb, nlh, table, chain, rule,
- NFT_MSG_DELRULE, 0, family);
- nf_tables_rule_destroy(rule);
+ err = nf_tables_delrule_one(&ctx, rule);
} else {
/* Remove all rules in this chain */
list_for_each_entry_safe(rule, tmp, &chain->rules, list) {
- list_del_rcu(&rule->list);
+ err = nf_tables_delrule_one(&ctx, rule);
+ if (err < 0)
+ break;
+ }
+ }
+
+ return err;
+}
+
+static int nf_tables_commit(struct sk_buff *skb)
+{
+ struct net *net = sock_net(skb->sk);
+ struct nft_rule_trans *rupd, *tmp;
- nf_tables_rule_notify(skb, nlh, table, chain, rule,
- NFT_MSG_DELRULE, 0, family);
- nf_tables_rule_destroy(rule);
+ /* Bump generation counter, invalidate any dump in progress */
+ net->nft.genctr++;
+
+ /* A new generation has just started */
+ net->nft.gencursor = gencursor_next(net);
+
+ /* Make sure all packets have left the previous generation before
+ * purging old rules.
+ */
+ synchronize_rcu();
+
+ list_for_each_entry_safe(rupd, tmp, &net->nft.commit_list, list) {
+ /* Delete this rule from the dirty list */
+ list_del(&rupd->list);
+
+ /* This rule was inactive in the past and just became active.
+ * Clear the next bit of the genmask since its meaning has
+ * changed, now it is the future.
+ */
+ if (nft_rule_is_active(net, rupd->rule)) {
+ nft_rule_clear(net, rupd->rule);
+ nf_tables_rule_notify(skb, rupd->nlh, rupd->table,
+ rupd->chain, rupd->rule,
+ NFT_MSG_NEWRULE, 0,
+ rupd->family);
+ kfree(rupd);
+ continue;
}
+
+ /* This rule is in the past, get rid of it */
+ list_del_rcu(&rupd->rule->list);
+ nf_tables_rule_notify(skb, rupd->nlh, rupd->table, rupd->chain,
+ rupd->rule, NFT_MSG_DELRULE, 0,
+ rupd->family);
+ nf_tables_rule_destroy(rupd->rule);
+ kfree(rupd);
}
return 0;
}
+static int nf_tables_abort(struct sk_buff *skb)
+{
+ struct net *net = sock_net(skb->sk);
+ struct nft_rule_trans *rupd, *tmp;
+
+ list_for_each_entry_safe(rupd, tmp, &net->nft.commit_list, list) {
+ /* Delete all rules from the dirty list */
+ list_del(&rupd->list);
+
+ if (!nft_rule_is_active_next(net, rupd->rule)) {
+ nft_rule_clear(net, rupd->rule);
+ kfree(rupd);
+ continue;
+ }
+
+ /* This rule is inactive, get rid of it */
+ list_del_rcu(&rupd->rule->list);
+ nf_tables_rule_destroy(rupd->rule);
+ kfree(rupd);
+ }
+ return 0;
+}
+
/*
* Sets
*/
@@ -2634,7 +2797,7 @@ static const struct nfnl_callback nf_tables_cb[NFT_MSG_MAX] = {
.policy = nft_chain_policy,
},
[NFT_MSG_NEWRULE] = {
- .call = nf_tables_newrule,
+ .call_batch = nf_tables_newrule,
.attr_count = NFTA_RULE_MAX,
.policy = nft_rule_policy,
},
@@ -2644,7 +2807,7 @@ static const struct nfnl_callback nf_tables_cb[NFT_MSG_MAX] = {
.policy = nft_rule_policy,
},
[NFT_MSG_DELRULE] = {
- .call = nf_tables_delrule,
+ .call_batch = nf_tables_delrule,
.attr_count = NFTA_RULE_MAX,
.policy = nft_rule_policy,
},
@@ -2685,6 +2848,8 @@ static const struct nfnetlink_subsystem nf_tables_subsys = {
.subsys_id = NFNL_SUBSYS_NFTABLES,
.cb_count = NFT_MSG_MAX,
.cb = nf_tables_cb,
+ .commit = nf_tables_commit,
+ .abort = nf_tables_abort,
};
/*
@@ -3056,6 +3221,7 @@ EXPORT_SYMBOL_GPL(nft_data_dump);
static int nf_tables_init_net(struct net *net)
{
INIT_LIST_HEAD(&net->nft.af_info);
+ INIT_LIST_HEAD(&net->nft.commit_list);
return 0;
}