* [PATCH 6.1 2/2] netfilter: nf_tables: support for adding new devices to an existing netdev chain
[not found] ` <20261002042509.711-1-1564938642@qq.com>
@ 2026-10-02 4:25 ` Ma Xinmeng
0 siblings, 0 replies; 4+ messages in thread
From: Ma Xinmeng @ 2026-10-02 4:25 UTC (permalink / raw)
To: Pablo Neira Ayuso, Florian Westphal; +Cc: netfilter-devel, stable, linux-kernel
From: Pablo Neira Ayuso <pablo@netfilter.org>
This patch allows users to add devices to an existing netdev chain.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ma Xinmeng <1564938642@qq.com>
This is a 6.1 backport of upstream commit b9703ed44ffb, adapted to 6.1's
nft_chain_parse_hook() and nf_tables_chain_destroy() signatures.
---
include/net/netfilter/nf_tables.h | 6 +
net/netfilter/nf_tables_api.c | 213 +++++++++++++++++++-----------
2 files changed, 140 insertions(+), 79 deletions(-)
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 7e63281f2..e79d5f294 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -1625,6 +1625,8 @@ struct nft_trans_chain {
u8 policy;
bool bound;
u32 chain_id;
+ struct nft_base_chain *basechain;
+ struct list_head hook_list;
};
#define nft_trans_chain(trans) \
@@ -1641,6 +1643,10 @@ struct nft_trans_chain {
(((struct nft_trans_chain *)trans->data)->bound)
#define nft_trans_chain_id(trans) \
(((struct nft_trans_chain *)trans->data)->chain_id)
+#define nft_trans_basechain(trans) \
+ (((struct nft_trans_chain *)trans->data)->basechain)
+#define nft_trans_chain_hooks(trans) \
+ (((struct nft_trans_chain *)trans->data)->hook_list)
struct nft_trans_table {
bool update;
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 18aa388d5..df26de2eb 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1750,7 +1750,8 @@ static int nft_dump_stats(struct sk_buff *skb, struct nft_stats __percpu *stats)
}
static int nft_dump_basechain_hook(struct sk_buff *skb, int family,
- const struct nft_base_chain *basechain)
+ const struct nft_base_chain *basechain,
+ const struct list_head *hook_list)
{
const struct nf_hook_ops *ops = &basechain->ops;
struct nft_hook *hook, *first = NULL;
@@ -1767,7 +1768,11 @@ static int nft_dump_basechain_hook(struct sk_buff *skb, int family,
if (nft_base_chain_netdev(family, ops->hooknum)) {
nest_devs = nla_nest_start_noflag(skb, NFTA_HOOK_DEVS);
- list_for_each_entry(hook, &basechain->hook_list, list) {
+
+ if (!hook_list)
+ hook_list = &basechain->hook_list;
+
+ list_for_each_entry(hook, hook_list, list) {
if (!first)
first = hook;
@@ -1792,7 +1797,8 @@ static int nft_dump_basechain_hook(struct sk_buff *skb, int family,
static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net,
u32 portid, u32 seq, int event, u32 flags,
int family, const struct nft_table *table,
- const struct nft_chain *chain)
+ const struct nft_chain *chain,
+ const struct list_head *hook_list)
{
struct nlmsghdr *nlh;
@@ -1814,7 +1820,7 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net,
const struct nft_base_chain *basechain = nft_base_chain(chain);
struct nft_stats __percpu *stats;
- if (nft_dump_basechain_hook(skb, family, basechain))
+ if (nft_dump_basechain_hook(skb, family, basechain, hook_list))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_CHAIN_POLICY,
@@ -1849,7 +1855,8 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net,
return -1;
}
-static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event)
+static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event,
+ const struct list_head *hook_list)
{
struct nftables_pernet *nft_net;
struct sk_buff *skb;
@@ -1869,7 +1876,7 @@ static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event)
err = nf_tables_fill_chain_info(skb, ctx->net, ctx->portid, ctx->seq,
event, flags, ctx->family, ctx->table,
- ctx->chain);
+ ctx->chain, hook_list);
if (err < 0) {
kfree_skb(skb);
goto err;
@@ -1915,7 +1922,7 @@ static int nf_tables_dump_chains(struct sk_buff *skb,
NFT_MSG_NEWCHAIN,
NLM_F_MULTI,
table->family, table,
- chain) < 0)
+ chain, NULL) < 0)
goto done;
nl_dump_check_consistent(cb, nlmsg_hdr(skb));
@@ -1969,7 +1976,7 @@ static int nf_tables_getchain(struct sk_buff *skb, const struct nfnl_info *info,
err = nf_tables_fill_chain_info(skb2, net, NETLINK_CB(skb).portid,
info->nlh->nlmsg_seq, NFT_MSG_NEWCHAIN,
- 0, family, table, chain);
+ 0, family, table, chain, NULL);
if (err < 0)
goto err_fill_chain_info;
@@ -2207,6 +2214,7 @@ static int nft_chain_parse_netdev(struct net *net,
}
static int nft_chain_parse_hook(struct net *net,
+ struct nft_base_chain *basechain,
const struct nlattr * const nla[],
struct nft_chain_hook *hook, u8 family,
struct netlink_ext_ack *extack, bool autoload,
@@ -2226,31 +2234,46 @@ static int nft_chain_parse_hook(struct net *net,
if (err < 0)
return err;
- if (ha[NFTA_HOOK_HOOKNUM] == NULL ||
- ha[NFTA_HOOK_PRIORITY] == NULL)
- return -EINVAL;
+ if (!basechain) {
+ if (!ha[NFTA_HOOK_HOOKNUM] ||
+ !ha[NFTA_HOOK_PRIORITY])
+ return -EINVAL;
- hook->num = ntohl(nla_get_be32(ha[NFTA_HOOK_HOOKNUM]));
- hook->priority = ntohl(nla_get_be32(ha[NFTA_HOOK_PRIORITY]));
+ hook->num = ntohl(nla_get_be32(ha[NFTA_HOOK_HOOKNUM]));
+ hook->priority = ntohl(nla_get_be32(ha[NFTA_HOOK_PRIORITY]));
- type = __nft_chain_type_get(family, NFT_CHAIN_T_DEFAULT);
- if (!type)
- return -EOPNOTSUPP;
+ type = __nft_chain_type_get(family, NFT_CHAIN_T_DEFAULT);
+ if (!type)
+ return -EOPNOTSUPP;
- if (nla[NFTA_CHAIN_TYPE]) {
- type = nf_tables_chain_type_lookup(net, nla[NFTA_CHAIN_TYPE],
- family, autoload);
- if (IS_ERR(type)) {
- NL_SET_BAD_ATTR(extack, nla[NFTA_CHAIN_TYPE]);
- return PTR_ERR(type);
+ if (nla[NFTA_CHAIN_TYPE]) {
+ type = nf_tables_chain_type_lookup(net, nla[NFTA_CHAIN_TYPE],
+ family, autoload);
+ if (IS_ERR(type)) {
+ NL_SET_BAD_ATTR(extack, nla[NFTA_CHAIN_TYPE]);
+ return PTR_ERR(type);
+ }
}
- }
- if (hook->num >= NFT_MAX_HOOKS || !(type->hook_mask & (1 << hook->num)))
- return -EOPNOTSUPP;
+ if (hook->num >= NFT_MAX_HOOKS || !(type->hook_mask & (1 << hook->num)))
+ return -EOPNOTSUPP;
- if (type->type == NFT_CHAIN_T_NAT &&
- hook->priority <= NF_IP_PRI_CONNTRACK)
- return -EOPNOTSUPP;
+ if (type->type == NFT_CHAIN_T_NAT &&
+ hook->priority <= NF_IP_PRI_CONNTRACK)
+ return -EOPNOTSUPP;
+ } else {
+ if (ha[NFTA_HOOK_HOOKNUM]) {
+ hook->num = ntohl(nla_get_be32(ha[NFTA_HOOK_HOOKNUM]));
+ if (hook->num != basechain->ops.hooknum)
+ return -EOPNOTSUPP;
+ }
+ if (ha[NFTA_HOOK_PRIORITY]) {
+ hook->priority = ntohl(nla_get_be32(ha[NFTA_HOOK_PRIORITY]));
+ if (hook->priority != basechain->ops.priority)
+ return -EOPNOTSUPP;
+ }
+
+ type = basechain->type;
+ }
if (!try_module_get(type->owner)) {
if (nla[NFTA_CHAIN_TYPE])
@@ -2348,12 +2371,8 @@ static int nft_basechain_init(struct nft_base_chain *basechain, u8 family,
list_splice_init(&hook->list, &basechain->hook_list);
list_for_each_entry(h, &basechain->hook_list, list)
nft_basechain_hook_init(&h->ops, family, hook, chain);
-
- basechain->ops.hooknum = hook->num;
- basechain->ops.priority = hook->priority;
- } else {
- nft_basechain_hook_init(&basechain->ops, family, hook, chain);
}
+ nft_basechain_hook_init(&basechain->ops, family, hook, chain);
chain->flags |= NFT_CHAIN_BASE | flags;
basechain->policy = NF_ACCEPT;
@@ -2401,7 +2420,7 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
if (nla[NFTA_CHAIN_HOOK]) {
struct nft_stats __percpu *stats = NULL;
- struct nft_chain_hook hook;
+ struct nft_chain_hook hook = {};
if (table->flags & __NFT_TABLE_F_UPDATE)
return -EINVAL;
@@ -2409,7 +2428,7 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
if (flags & NFT_CHAIN_BINDING)
return -EOPNOTSUPP;
- err = nft_chain_parse_hook(net, nla, &hook, family, extack,
+ err = nft_chain_parse_hook(net, NULL, nla, &hook, family, extack,
true, flags);
if (err < 0)
return err;
@@ -2533,65 +2552,57 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
return err;
}
-static bool nft_hook_list_equal(struct list_head *hook_list1,
- struct list_head *hook_list2)
-{
- struct nft_hook *hook;
- int n = 0, m = 0;
-
- n = 0;
- list_for_each_entry(hook, hook_list2, list) {
- if (!nft_hook_list_find(hook_list1, hook))
- return false;
-
- n++;
- }
- list_for_each_entry(hook, hook_list1, list)
- m++;
-
- return n == m;
-}
-
static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
u32 flags, const struct nlattr *attr,
struct netlink_ext_ack *extack)
{
const struct nlattr * const *nla = ctx->nla;
+ struct nft_base_chain *basechain = NULL;
struct nft_table *table = ctx->table;
struct nft_chain *chain = ctx->chain;
- struct nft_base_chain *basechain;
+ struct nft_chain_hook hook = {};
struct nft_stats *stats = NULL;
- struct nft_chain_hook hook;
+ struct nft_hook *h, *next;
struct nf_hook_ops *ops;
struct nft_trans *trans;
+ bool unregister = false;
int err;
if (chain->flags ^ flags)
return -EOPNOTSUPP;
+ INIT_LIST_HEAD(&hook.list);
+
if (nla[NFTA_CHAIN_HOOK]) {
if (!nft_is_base_chain(chain)) {
NL_SET_BAD_ATTR(extack, attr);
return -EEXIST;
}
- err = nft_chain_parse_hook(ctx->net, nla, &hook, ctx->family,
- extack, false, flags);
+
+ basechain = nft_base_chain(chain);
+ err = nft_chain_parse_hook(ctx->net, basechain, nla, &hook,
+ ctx->family, extack, false, flags);
if (err < 0)
return err;
- basechain = nft_base_chain(chain);
if (basechain->type != hook.type) {
nft_chain_release_hook(&hook);
NL_SET_BAD_ATTR(extack, attr);
return -EEXIST;
}
- if (nft_base_chain_netdev(ctx->family, hook.num)) {
- if (!nft_hook_list_equal(&basechain->hook_list,
- &hook.list)) {
- nft_chain_release_hook(&hook);
- NL_SET_BAD_ATTR(extack, attr);
- return -EEXIST;
+ if (nft_base_chain_netdev(ctx->family, basechain->ops.hooknum)) {
+ list_for_each_entry_safe(h, next, &hook.list, list) {
+ h->ops.pf = basechain->ops.pf;
+ h->ops.hooknum = basechain->ops.hooknum;
+ h->ops.priority = basechain->ops.priority;
+ h->ops.priv = basechain->ops.priv;
+ h->ops.hook = basechain->ops.hook;
+
+ if (nft_hook_list_find(&basechain->hook_list, h)) {
+ list_del(&h->list);
+ kfree(h);
+ }
}
} else {
ops = &basechain->ops;
@@ -2602,7 +2613,6 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
return -EEXIST;
}
}
- nft_chain_release_hook(&hook);
}
if (nla[NFTA_CHAIN_HANDLE] &&
@@ -2613,24 +2623,43 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
nla[NFTA_CHAIN_NAME], genmask);
if (!IS_ERR(chain2)) {
NL_SET_BAD_ATTR(extack, nla[NFTA_CHAIN_NAME]);
- return -EEXIST;
+ err = -EEXIST;
+ goto err_hooks;
}
}
if (nla[NFTA_CHAIN_COUNTERS]) {
- if (!nft_is_base_chain(chain))
- return -EOPNOTSUPP;
+ if (!nft_is_base_chain(chain)) {
+ err = -EOPNOTSUPP;
+ goto err_hooks;
+ }
stats = nft_stats_alloc(nla[NFTA_CHAIN_COUNTERS]);
- if (IS_ERR(stats))
- return PTR_ERR(stats);
+ if (IS_ERR(stats)) {
+ err = PTR_ERR(stats);
+ goto err_hooks;
+ }
}
+ if (!(table->flags & NFT_TABLE_F_DORMANT) &&
+ nft_is_base_chain(chain) &&
+ !list_empty(&hook.list)) {
+ basechain = nft_base_chain(chain);
+ ops = &basechain->ops;
+
+ if (nft_base_chain_netdev(table->family, basechain->ops.hooknum)) {
+ err = nft_netdev_register_hooks(ctx->net, &hook.list);
+ if (err < 0)
+ goto err_hooks;
+ }
+ }
+
+ unregister = true;
err = -ENOMEM;
trans = nft_trans_alloc(ctx, NFT_MSG_NEWCHAIN,
sizeof(struct nft_trans_chain));
if (trans == NULL)
- goto err;
+ goto err_trans;
nft_trans_chain_stats(trans) = stats;
nft_trans_chain_update(trans) = true;
@@ -2649,7 +2678,7 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
err = -ENOMEM;
name = nla_strdup(nla[NFTA_CHAIN_NAME], GFP_KERNEL_ACCOUNT);
if (!name)
- goto err;
+ goto err_trans;
err = -EEXIST;
list_for_each_entry(tmp, &nft_net->commit_list, list) {
@@ -2660,18 +2689,35 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
strcmp(name, nft_trans_chain_name(tmp)) == 0) {
NL_SET_BAD_ATTR(extack, nla[NFTA_CHAIN_NAME]);
kfree(name);
- goto err;
+ goto err_trans;
}
}
nft_trans_chain_name(trans) = name;
}
+
+ nft_trans_basechain(trans) = basechain;
+ INIT_LIST_HEAD(&nft_trans_chain_hooks(trans));
+ list_splice(&hook.list, &nft_trans_chain_hooks(trans));
+
nft_trans_commit_list_add_tail(ctx->net, trans);
return 0;
-err:
+
+err_trans:
free_percpu(stats);
kfree(trans);
+err_hooks:
+ if (nla[NFTA_CHAIN_HOOK]) {
+ list_for_each_entry_safe(h, next, &hook.list, list) {
+ if (unregister)
+ nf_unregister_net_hook(ctx->net, &h->ops);
+ list_del(&h->list);
+ kfree_rcu(h, rcu);
+ }
+ module_put(hook.type->owner);
+ }
+
return err;
}
@@ -9876,18 +9922,21 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
case NFT_MSG_NEWCHAIN:
if (nft_trans_chain_update(trans)) {
nft_chain_commit_update(trans);
- nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN);
+ nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN,
+ &nft_trans_chain_hooks(trans));
+ list_splice(&nft_trans_chain_hooks(trans),
+ &nft_trans_basechain(trans)->hook_list);
/* trans destroyed after rcu grace period */
} else {
nft_chain_commit_drop_policy(trans);
nft_clear(net, trans->ctx.chain);
- nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN);
+ nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN, NULL);
nft_trans_destroy(trans);
}
break;
case NFT_MSG_DELCHAIN:
nft_chain_del(trans->ctx.chain);
- nf_tables_chain_notify(&trans->ctx, NFT_MSG_DELCHAIN);
+ nf_tables_chain_notify(&trans->ctx, NFT_MSG_DELCHAIN, NULL);
nf_tables_unregister_hook(trans->ctx.net,
trans->ctx.table,
trans->ctx.chain);
@@ -10066,7 +10115,10 @@ static void nf_tables_abort_release(struct nft_trans *trans)
nf_tables_table_destroy(&trans->ctx);
break;
case NFT_MSG_NEWCHAIN:
- nf_tables_chain_destroy(nft_trans_chain(trans));
+ if (nft_trans_chain_update(trans))
+ nft_hooks_destroy(&nft_trans_chain_hooks(trans));
+ else
+ nf_tables_chain_destroy(nft_trans_chain(trans));
break;
case NFT_MSG_NEWRULE:
nf_tables_rule_destroy(&trans->ctx, nft_trans_rule(trans));
@@ -10144,6 +10196,9 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
break;
case NFT_MSG_NEWCHAIN:
if (nft_trans_chain_update(trans)) {
+ nft_netdev_unregister_hooks(net,
+ &nft_trans_chain_hooks(trans),
+ true);
free_percpu(nft_trans_chain_stats(trans));
kfree(nft_trans_chain_name(trans));
nft_trans_destroy(trans);
--
2.43.0
^ permalink raw reply [flat|nested] 4+ messages in thread