* [PATCH nf-next 5/5] netfilter: nf_tables: support for multiple devices per netdev hook
2019-10-16 12:40 [PATCH nf-next 0/5] Hook multiple netdevices to basechain Pablo Neira Ayuso
` (3 preceding siblings ...)
2019-10-16 12:40 ` [PATCH nf-next 4/5] netfilter: nf_tables_offload: remove rules on unregistered device only Pablo Neira Ayuso
@ 2019-10-16 12:40 ` Pablo Neira Ayuso
4 siblings, 0 replies; 6+ messages in thread
From: Pablo Neira Ayuso @ 2019-10-16 12:40 UTC (permalink / raw)
To: netfilter-devel
This patch allows you to register one netdev basechain to multiple
devices. This adds a new NFTA_HOOK_DEVS netlink attribute to specify
the list of netdevices. Basechains store a list of hooks.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/net/netfilter/nf_tables.h | 4 +-
include/uapi/linux/netfilter/nf_tables.h | 2 +
net/netfilter/nf_tables_api.c | 296 ++++++++++++++++++++++++-------
net/netfilter/nf_tables_offload.c | 11 +-
net/netfilter/nft_chain_filter.c | 45 +++--
5 files changed, 272 insertions(+), 86 deletions(-)
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 3d71070e747a..5bf569e1173b 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -973,21 +973,21 @@ struct nft_hook {
* struct nft_base_chain - nf_tables base chain
*
* @ops: netfilter hook ops
+ * @hook_list: list of netfilter hooks (for NFPROTO_NETDEV family)
* @type: chain type
* @policy: default policy
* @stats: per-cpu chain stats
* @chain: the chain
- * @dev_name: device name that this base chain is attached to (if any)
* @flow_block: flow block (for hardware offload)
*/
struct nft_base_chain {
struct nf_hook_ops ops;
+ struct list_head hook_list;
const struct nft_chain_type *type;
u8 policy;
u8 flags;
struct nft_stats __percpu *stats;
struct nft_chain chain;
- char dev_name[IFNAMSIZ];
struct flow_block flow_block;
};
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index ed8881ad18ed..81fed16fe2b2 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -144,12 +144,14 @@ 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)
+ * @NFTA_HOOK_DEVS: list of netdevices (NLA_NESTED)
*/
enum nft_hook_attributes {
NFTA_HOOK_UNSPEC,
NFTA_HOOK_HOOKNUM,
NFTA_HOOK_PRIORITY,
NFTA_HOOK_DEV,
+ NFTA_HOOK_DEVS,
__NFTA_HOOK_MAX
};
#define NFTA_HOOK_MAX (__NFTA_HOOK_MAX - 1)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index d736a0cd056c..ffedcb081ab8 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -151,11 +151,64 @@ static void nft_set_trans_bind(const struct nft_ctx *ctx, struct nft_set *set)
}
}
+static int nft_netdev_register_hooks(struct net *net,
+ struct list_head *hook_list)
+{
+ struct nft_hook *hook;
+ int err, j;
+
+ j = 0;
+ list_for_each_entry(hook, hook_list, list) {
+ err = nf_register_net_hook(net, &hook->ops);
+ if (err < 0)
+ goto err_register;
+
+ j++;
+ }
+ return 0;
+
+err_register:
+ list_for_each_entry(hook, hook_list, list) {
+ if (j-- <= 0)
+ break;
+
+ nf_unregister_net_hook(net, &hook->ops);
+ }
+ return err;
+}
+
+static void nft_netdev_unregister_hooks(struct net *net,
+ struct list_head *hook_list)
+{
+ struct nft_hook *hook;
+
+ list_for_each_entry(hook, hook_list, list)
+ nf_unregister_net_hook(net, &hook->ops);
+}
+
+static int nft_register_basechain_hooks(struct net *net, int family,
+ struct nft_base_chain *basechain)
+{
+ if (family == NFPROTO_NETDEV)
+ return nft_netdev_register_hooks(net, &basechain->hook_list);
+
+ return nf_register_net_hook(net, &basechain->ops);
+}
+
+static void nft_unregister_basechain_hooks(struct net *net, int family,
+ struct nft_base_chain *basechain)
+{
+ if (family == NFPROTO_NETDEV)
+ nft_netdev_unregister_hooks(net, &basechain->hook_list);
+ else
+ nf_unregister_net_hook(net, &basechain->ops);
+}
+
static int nf_tables_register_hook(struct net *net,
const struct nft_table *table,
struct nft_chain *chain)
{
- const struct nft_base_chain *basechain;
+ struct nft_base_chain *basechain;
const struct nf_hook_ops *ops;
if (table->flags & NFT_TABLE_F_DORMANT ||
@@ -168,14 +221,14 @@ static int nf_tables_register_hook(struct net *net,
if (basechain->type->ops_register)
return basechain->type->ops_register(net, ops);
- return nf_register_net_hook(net, ops);
+ return nft_register_basechain_hooks(net, table->family, basechain);
}
static void nf_tables_unregister_hook(struct net *net,
const struct nft_table *table,
struct nft_chain *chain)
{
- const struct nft_base_chain *basechain;
+ struct nft_base_chain *basechain;
const struct nf_hook_ops *ops;
if (table->flags & NFT_TABLE_F_DORMANT ||
@@ -187,7 +240,7 @@ static void nf_tables_unregister_hook(struct net *net,
if (basechain->type->ops_unregister)
return basechain->type->ops_unregister(net, ops);
- nf_unregister_net_hook(net, ops);
+ nft_unregister_basechain_hooks(net, table->family, basechain);
}
static int nft_trans_table_add(struct nft_ctx *ctx, int msg_type)
@@ -742,7 +795,8 @@ static void nft_table_disable(struct net *net, struct nft_table *table, u32 cnt)
if (cnt && i++ == cnt)
break;
- nf_unregister_net_hook(net, &nft_base_chain(chain)->ops);
+ nft_unregister_basechain_hooks(net, table->family,
+ nft_base_chain(chain));
}
}
@@ -757,14 +811,16 @@ static int nf_tables_table_enable(struct net *net, struct nft_table *table)
if (!nft_is_base_chain(chain))
continue;
- err = nf_register_net_hook(net, &nft_base_chain(chain)->ops);
+ err = nft_register_basechain_hooks(net, table->family,
+ nft_base_chain(chain));
if (err < 0)
- goto err;
+ goto err_register_hooks;
i++;
}
return 0;
-err:
+
+err_register_hooks:
if (i)
nft_table_disable(net, table, i);
return err;
@@ -1225,6 +1281,46 @@ static int nft_dump_stats(struct sk_buff *skb, struct nft_stats __percpu *stats)
return -ENOSPC;
}
+static int nft_dump_basechain_hook(struct sk_buff *skb, int family,
+ const struct nft_base_chain *basechain)
+{
+ const struct nf_hook_ops *ops = &basechain->ops;
+ struct nft_hook *hook, *first = NULL;
+ struct nlattr *nest, *nest_devs;
+ int n = 0;
+
+ nest = nla_nest_start_noflag(skb, NFTA_CHAIN_HOOK);
+ if (nest == NULL)
+ goto nla_put_failure;
+ if (nla_put_be32(skb, NFTA_HOOK_HOOKNUM, htonl(ops->hooknum)))
+ goto nla_put_failure;
+ if (nla_put_be32(skb, NFTA_HOOK_PRIORITY, htonl(ops->priority)))
+ goto nla_put_failure;
+
+ if (family == NFPROTO_NETDEV) {
+ nest_devs = nla_nest_start_noflag(skb, NFTA_HOOK_DEVS);
+ list_for_each_entry(hook, &basechain->hook_list, list) {
+ if (!first)
+ first = hook;
+
+ if (nla_put_string(skb, NFTA_DEVICE_NAME,
+ hook->ops.dev->name))
+ goto nla_put_failure;
+ n++;
+ }
+ nla_nest_end(skb, nest_devs);
+
+ if (n == 1 &&
+ nla_put_string(skb, NFTA_HOOK_DEV, first->ops.dev->name))
+ goto nla_put_failure;
+ }
+ nla_nest_end(skb, nest);
+
+ return 0;
+nla_put_failure:
+ return -1;
+}
+
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,
@@ -1253,21 +1349,10 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net,
if (nft_is_base_chain(chain)) {
const struct nft_base_chain *basechain = nft_base_chain(chain);
- const struct nf_hook_ops *ops = &basechain->ops;
struct nft_stats __percpu *stats;
- struct nlattr *nest;
- nest = nla_nest_start_noflag(skb, NFTA_CHAIN_HOOK);
- if (nest == NULL)
+ if (nft_dump_basechain_hook(skb, family, basechain))
goto nla_put_failure;
- if (nla_put_be32(skb, NFTA_HOOK_HOOKNUM, htonl(ops->hooknum)))
- 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,
htonl(basechain->policy)))
@@ -1485,6 +1570,7 @@ static void nf_tables_chain_free_chain_rules(struct nft_chain *chain)
static void nf_tables_chain_destroy(struct nft_ctx *ctx)
{
struct nft_chain *chain = ctx->chain;
+ struct nft_hook *hook, *next;
if (WARN_ON(chain->use > 0))
return;
@@ -1495,6 +1581,13 @@ static void nf_tables_chain_destroy(struct nft_ctx *ctx)
if (nft_is_base_chain(chain)) {
struct nft_base_chain *basechain = nft_base_chain(chain);
+ if (ctx->family == NFPROTO_NETDEV) {
+ list_for_each_entry_safe(hook, next,
+ &basechain->hook_list, list) {
+ list_del_rcu(&hook->list);
+ kfree_rcu(hook, rcu);
+ }
+ }
module_put(basechain->type->owner);
if (rcu_access_pointer(basechain->stats)) {
static_branch_dec(&nft_counters_enabled);
@@ -1599,9 +1692,34 @@ struct nft_chain_hook {
u32 num;
s32 priority;
const struct nft_chain_type *type;
- struct net_device *dev;
+ struct list_head list;
};
+static int nft_chain_parse_netdev(struct net *net,
+ struct nlattr *tb[],
+ struct list_head *hook_list)
+{
+ struct nft_hook *hook;
+ int err;
+
+ if (tb[NFTA_HOOK_DEV]) {
+ hook = nft_netdev_hook_alloc(net, tb[NFTA_HOOK_DEV]);
+ if (IS_ERR(hook))
+ return PTR_ERR(hook);
+
+ list_add_tail(&hook->list, hook_list);
+ } else if (tb[NFTA_HOOK_DEVS]) {
+ err = nf_tables_parse_netdev_hooks(net, tb[NFTA_HOOK_DEVS],
+ hook_list);
+ if (err < 0)
+ return err;
+ } else {
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int nft_chain_parse_hook(struct net *net,
const struct nlattr * const nla[],
struct nft_chain_hook *hook, u8 family,
@@ -1609,7 +1727,6 @@ static int nft_chain_parse_hook(struct net *net,
{
struct nlattr *ha[NFTA_HOOK_MAX + 1];
const struct nft_chain_type *type;
- struct net_device *dev;
int err;
lockdep_assert_held(&net->nft.commit_mutex);
@@ -1647,23 +1764,14 @@ static int nft_chain_parse_hook(struct net *net,
hook->type = type;
- hook->dev = NULL;
+ INIT_LIST_HEAD(&hook->list);
if (family == NFPROTO_NETDEV) {
- 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) {
+ err = nft_chain_parse_netdev(net, ha, &hook->list);
+ if (err < 0) {
module_put(type->owner);
- return -ENOENT;
+ return err;
}
- hook->dev = dev;
- } else if (ha[NFTA_HOOK_DEV]) {
+ } else if (ha[NFTA_HOOK_DEV] || ha[NFTA_HOOK_DEVS]) {
module_put(type->owner);
return -EOPNOTSUPP;
}
@@ -1673,6 +1781,12 @@ static int nft_chain_parse_hook(struct net *net,
static void nft_chain_release_hook(struct nft_chain_hook *hook)
{
+ struct nft_hook *h, *next;
+
+ list_for_each_entry_safe(h, next, &hook->list, list) {
+ list_del(&h->list);
+ kfree(h);
+ }
module_put(hook->type->owner);
}
@@ -1697,6 +1811,49 @@ static struct nft_rule **nf_tables_chain_alloc_rules(const struct nft_chain *cha
return kvmalloc(alloc, GFP_KERNEL);
}
+static void nft_basechain_hook_init(struct nf_hook_ops *ops, u8 family,
+ const struct nft_chain_hook *hook,
+ struct nft_chain *chain)
+{
+ ops->pf = family;
+ ops->hooknum = hook->num;
+ ops->priority = hook->priority;
+ ops->priv = chain;
+ ops->hook = hook->type->hooks[ops->hooknum];
+}
+
+static int nft_basechain_init(struct nft_base_chain *basechain, u8 family,
+ struct nft_chain_hook *hook, u32 flags)
+{
+ struct nft_chain *chain;
+ struct nft_hook *h;
+
+ basechain->type = hook->type;
+ INIT_LIST_HEAD(&basechain->hook_list);
+ chain = &basechain->chain;
+
+ if (family == NFPROTO_NETDEV) {
+ 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);
+ }
+
+ chain->flags |= NFT_BASE_CHAIN | flags;
+ basechain->policy = NF_ACCEPT;
+ if (chain->flags & NFT_CHAIN_HW_OFFLOAD &&
+ nft_chain_offload_priority(basechain) < 0)
+ return -EOPNOTSUPP;
+
+ flow_block_init(&basechain->flow_block);
+
+ return 0;
+}
+
static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
u8 policy, u32 flags)
{
@@ -1715,7 +1872,6 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
if (nla[NFTA_CHAIN_HOOK]) {
struct nft_chain_hook hook;
- struct nf_hook_ops *ops;
err = nft_chain_parse_hook(net, nla, &hook, family, true);
if (err < 0)
@@ -1726,9 +1882,7 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
nft_chain_release_hook(&hook);
return -ENOMEM;
}
-
- if (hook.dev != NULL)
- strncpy(basechain->dev_name, hook.dev->name, IFNAMSIZ);
+ chain = &basechain->chain;
if (nla[NFTA_CHAIN_COUNTERS]) {
stats = nft_stats_alloc(nla[NFTA_CHAIN_COUNTERS]);
@@ -1741,24 +1895,12 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
static_branch_inc(&nft_counters_enabled);
}
- basechain->type = hook.type;
- chain = &basechain->chain;
-
- ops = &basechain->ops;
- ops->pf = family;
- ops->hooknum = hook.num;
- ops->priority = hook.priority;
- ops->priv = chain;
- ops->hook = hook.type->hooks[ops->hooknum];
- ops->dev = hook.dev;
-
- chain->flags |= NFT_BASE_CHAIN | flags;
- basechain->policy = NF_ACCEPT;
- if (chain->flags & NFT_CHAIN_HW_OFFLOAD &&
- nft_chain_offload_priority(basechain) < 0)
- return -EOPNOTSUPP;
-
- flow_block_init(&basechain->flow_block);
+ err = nft_basechain_init(basechain, family, &hook, flags);
+ if (err < 0) {
+ nft_chain_release_hook(&hook);
+ kfree(basechain);
+ return err;
+ }
} else {
chain = kzalloc(sizeof(*chain), GFP_KERNEL);
if (chain == NULL)
@@ -1818,6 +1960,25 @@ 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)
{
@@ -1849,12 +2010,19 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
return -EBUSY;
}
- ops = &basechain->ops;
- if (ops->hooknum != hook.num ||
- ops->priority != hook.priority ||
- ops->dev != hook.dev) {
- nft_chain_release_hook(&hook);
- return -EBUSY;
+ if (ctx->family == NFPROTO_NETDEV) {
+ if (!nft_hook_list_equal(&basechain->hook_list,
+ &hook.list)) {
+ nft_chain_release_hook(&hook);
+ return -EBUSY;
+ }
+ } else {
+ ops = &basechain->ops;
+ if (ops->hooknum != hook.num ||
+ ops->priority != hook.priority) {
+ nft_chain_release_hook(&hook);
+ return -EBUSY;
+ }
}
nft_chain_release_hook(&hook);
}
diff --git a/net/netfilter/nf_tables_offload.c b/net/netfilter/nf_tables_offload.c
index e7f32a9dad63..e4f42427244b 100644
--- a/net/netfilter/nf_tables_offload.c
+++ b/net/netfilter/nf_tables_offload.c
@@ -414,6 +414,7 @@ static struct nft_chain *__nft_offload_get_chain(struct net_device *dev)
{
struct nft_base_chain *basechain;
struct net *net = dev_net(dev);
+ struct nft_hook *hook, *found;
const struct nft_table *table;
struct nft_chain *chain;
@@ -426,8 +427,16 @@ static struct nft_chain *__nft_offload_get_chain(struct net_device *dev)
!(chain->flags & NFT_CHAIN_HW_OFFLOAD))
continue;
+ found = NULL;
basechain = nft_base_chain(chain);
- if (strncmp(basechain->dev_name, dev->name, IFNAMSIZ))
+ list_for_each_entry(hook, &basechain->hook_list, list) {
+ if (hook->ops.dev != dev)
+ continue;
+
+ found = hook;
+ break;
+ }
+ if (!found)
continue;
return chain;
diff --git a/net/netfilter/nft_chain_filter.c b/net/netfilter/nft_chain_filter.c
index b5d5d071d765..c78d01bc02e9 100644
--- a/net/netfilter/nft_chain_filter.c
+++ b/net/netfilter/nft_chain_filter.c
@@ -287,28 +287,35 @@ static void nft_netdev_event(unsigned long event, struct net_device *dev,
struct nft_ctx *ctx)
{
struct nft_base_chain *basechain = nft_base_chain(ctx->chain);
+ struct nft_hook *hook, *found = NULL;
+ int n = 0;
- switch (event) {
- case NETDEV_UNREGISTER:
- if (strcmp(basechain->dev_name, dev->name) != 0)
- return;
-
- /* UNREGISTER events are also happpening on netns exit.
- *
- * Altough nf_tables core releases all tables/chains, only
- * this event handler provides guarantee that
- * basechain.ops->dev is still accessible, so we cannot
- * skip exiting net namespaces.
- */
- __nft_release_basechain(ctx);
- break;
- case NETDEV_CHANGENAME:
- if (dev->ifindex != basechain->ops.dev->ifindex)
- return;
+ if (event != NETDEV_UNREGISTER)
+ return;
- strncpy(basechain->dev_name, dev->name, IFNAMSIZ);
- break;
+ list_for_each_entry(hook, &basechain->hook_list, list) {
+ if (hook->ops.dev == dev)
+ found = hook;
+
+ n++;
}
+ if (!found)
+ return;
+
+ if (n > 1) {
+ nf_unregister_net_hook(ctx->net, &found->ops);
+ list_del_rcu(&found->list);
+ kfree_rcu(found, rcu);
+ return;
+ }
+
+ /* UNREGISTER events are also happening on netns exit.
+ *
+ * Although nf_tables core releases all tables/chains, only this event
+ * handler provides guarantee that hook->ops.dev is still accessible,
+ * so we cannot skip exiting net namespaces.
+ */
+ __nft_release_basechain(ctx);
}
static int nf_tables_netdev_event(struct notifier_block *this,
--
2.11.0
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