From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Subject: [PATCH nf-next,v5 2/7] netfilter: nf_tables: do not send complete notification of deletions
Date: Thu, 20 Apr 2023 18:55:58 +0200 [thread overview]
Message-ID: <20230420165603.43876-2-pablo@netfilter.org> (raw)
In-Reply-To: <20230420165603.43876-1-pablo@netfilter.org>
In most cases, table, name and handle is sufficient for userspace to
identify an object that has been deleted. Skipping unneeded fields in
the netlink attributes in the message saves bandwidth (ie. less chances
of hitting ENOBUFS).
Rules are an exception: the existing userspace monitor code relies on
the rule definition. This exception can be removed by implementing a
rule cache in userspace, this is already supported by the tracing
infrastructure.
Regarding flowtables, incremental deletion of devices is possible.
Skipping a full notification allows userspace to differentiate between
flowtable removal and incremental removal of devices.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v5: no changes
net/netfilter/nf_tables_api.c | 70 +++++++++++++++++++++++++----------
1 file changed, 51 insertions(+), 19 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 900abed9f534..a47f94e377ac 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -821,12 +821,20 @@ static int nf_tables_fill_table_info(struct sk_buff *skb, struct net *net,
goto nla_put_failure;
if (nla_put_string(skb, NFTA_TABLE_NAME, table->name) ||
- nla_put_be32(skb, NFTA_TABLE_FLAGS,
- htonl(table->flags & NFT_TABLE_F_MASK)) ||
nla_put_be32(skb, NFTA_TABLE_USE, htonl(table->use)) ||
nla_put_be64(skb, NFTA_TABLE_HANDLE, cpu_to_be64(table->handle),
NFTA_TABLE_PAD))
goto nla_put_failure;
+
+ if (event == NFT_MSG_DELTABLE) {
+ nlmsg_end(skb, nlh);
+ return 0;
+ }
+
+ if (nla_put_be32(skb, NFTA_TABLE_FLAGS,
+ htonl(table->flags & NFT_TABLE_F_MASK)))
+ goto nla_put_failure;
+
if (nft_table_has_owner(table) &&
nla_put_be32(skb, NFTA_TABLE_OWNER, htonl(table->nlpid)))
goto nla_put_failure;
@@ -1627,13 +1635,16 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net,
if (!nlh)
goto nla_put_failure;
- if (nla_put_string(skb, NFTA_CHAIN_TABLE, table->name))
- goto nla_put_failure;
- if (nla_put_be64(skb, NFTA_CHAIN_HANDLE, cpu_to_be64(chain->handle),
+ if (nla_put_string(skb, NFTA_CHAIN_TABLE, table->name) ||
+ nla_put_string(skb, NFTA_CHAIN_NAME, chain->name) ||
+ nla_put_be64(skb, NFTA_CHAIN_HANDLE, cpu_to_be64(chain->handle),
NFTA_CHAIN_PAD))
goto nla_put_failure;
- if (nla_put_string(skb, NFTA_CHAIN_NAME, chain->name))
- goto nla_put_failure;
+
+ if (event == NFT_MSG_DELCHAIN) {
+ nlmsg_end(skb, nlh);
+ return 0;
+ }
if (nft_is_base_chain(chain)) {
const struct nft_base_chain *basechain = nft_base_chain(chain);
@@ -4157,6 +4168,12 @@ static int nf_tables_fill_set(struct sk_buff *skb, const struct nft_ctx *ctx,
if (nla_put_be64(skb, NFTA_SET_HANDLE, cpu_to_be64(set->handle),
NFTA_SET_PAD))
goto nla_put_failure;
+
+ if (event == NFT_MSG_DELSET) {
+ nlmsg_end(skb, nlh);
+ return 0;
+ }
+
if (set->flags != 0)
if (nla_put_be32(skb, NFTA_SET_FLAGS, htonl(set->flags)))
goto nla_put_failure;
@@ -7162,13 +7179,20 @@ static int nf_tables_fill_obj_info(struct sk_buff *skb, struct net *net,
if (nla_put_string(skb, NFTA_OBJ_TABLE, table->name) ||
nla_put_string(skb, NFTA_OBJ_NAME, obj->key.name) ||
- nla_put_be32(skb, NFTA_OBJ_TYPE, htonl(obj->ops->type->type)) ||
- nla_put_be32(skb, NFTA_OBJ_USE, htonl(obj->use)) ||
- nft_object_dump(skb, NFTA_OBJ_DATA, obj, reset) ||
nla_put_be64(skb, NFTA_OBJ_HANDLE, cpu_to_be64(obj->handle),
NFTA_OBJ_PAD))
goto nla_put_failure;
+ if (event == NFT_MSG_DELOBJ) {
+ nlmsg_end(skb, nlh);
+ return 0;
+ }
+
+ if (nla_put_be32(skb, NFTA_OBJ_TYPE, htonl(obj->ops->type->type)) ||
+ nla_put_be32(skb, NFTA_OBJ_USE, htonl(obj->use)) ||
+ nft_object_dump(skb, NFTA_OBJ_DATA, obj, reset))
+ goto nla_put_failure;
+
if (obj->udata &&
nla_put(skb, NFTA_OBJ_USERDATA, obj->udlen, obj->udata))
goto nla_put_failure;
@@ -8097,9 +8121,16 @@ static int nf_tables_fill_flowtable_info(struct sk_buff *skb, struct net *net,
if (nla_put_string(skb, NFTA_FLOWTABLE_TABLE, flowtable->table->name) ||
nla_put_string(skb, NFTA_FLOWTABLE_NAME, flowtable->name) ||
- nla_put_be32(skb, NFTA_FLOWTABLE_USE, htonl(flowtable->use)) ||
nla_put_be64(skb, NFTA_FLOWTABLE_HANDLE, cpu_to_be64(flowtable->handle),
- NFTA_FLOWTABLE_PAD) ||
+ NFTA_FLOWTABLE_PAD))
+ goto nla_put_failure;
+
+ if (event == NFT_MSG_DELFLOWTABLE && !hook_list) {
+ nlmsg_end(skb, nlh);
+ return 0;
+ }
+
+ if (nla_put_be32(skb, NFTA_FLOWTABLE_USE, htonl(flowtable->use)) ||
nla_put_be32(skb, NFTA_FLOWTABLE_FLAGS, htonl(flowtable->data.flags)))
goto nla_put_failure;
@@ -8114,6 +8145,9 @@ static int nf_tables_fill_flowtable_info(struct sk_buff *skb, struct net *net,
if (!nest_devs)
goto nla_put_failure;
+ if (!hook_list)
+ hook_list = &flowtable->hook_list;
+
list_for_each_entry_rcu(hook, hook_list, list) {
if (nla_put_string(skb, NFTA_DEVICE_NAME, hook->ops.dev->name))
goto nla_put_failure;
@@ -8170,8 +8204,7 @@ static int nf_tables_dump_flowtable(struct sk_buff *skb,
NFT_MSG_NEWFLOWTABLE,
NLM_F_MULTI | NLM_F_APPEND,
table->family,
- flowtable,
- &flowtable->hook_list) < 0)
+ flowtable, NULL) < 0)
goto done;
nl_dump_check_consistent(cb, nlmsg_hdr(skb));
@@ -8266,7 +8299,7 @@ static int nf_tables_getflowtable(struct sk_buff *skb,
err = nf_tables_fill_flowtable_info(skb2, net, NETLINK_CB(skb).portid,
info->nlh->nlmsg_seq,
NFT_MSG_NEWFLOWTABLE, 0, family,
- flowtable, &flowtable->hook_list);
+ flowtable, NULL);
if (err < 0)
goto err_fill_flowtable_info;
@@ -8279,8 +8312,7 @@ static int nf_tables_getflowtable(struct sk_buff *skb,
static void nf_tables_flowtable_notify(struct nft_ctx *ctx,
struct nft_flowtable *flowtable,
- struct list_head *hook_list,
- int event)
+ struct list_head *hook_list, int event)
{
struct nftables_pernet *nft_net = nft_pernet(ctx->net);
struct sk_buff *skb;
@@ -9340,7 +9372,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
nft_clear(net, nft_trans_flowtable(trans));
nf_tables_flowtable_notify(&trans->ctx,
nft_trans_flowtable(trans),
- &nft_trans_flowtable(trans)->hook_list,
+ NULL,
NFT_MSG_NEWFLOWTABLE);
}
nft_trans_destroy(trans);
@@ -9358,7 +9390,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
list_del_rcu(&nft_trans_flowtable(trans)->list);
nf_tables_flowtable_notify(&trans->ctx,
nft_trans_flowtable(trans),
- &nft_trans_flowtable(trans)->hook_list,
+ NULL,
trans->msg_type);
nft_unregister_flowtable_net_hooks(net,
&nft_trans_flowtable(trans)->hook_list);
--
2.30.2
next prev parent reply other threads:[~2023-04-20 17:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-20 16:55 [PATCH nf-next,v5 1/7] netfilter: nf_tables: extended netlink error reporting for netdevice Pablo Neira Ayuso
2023-04-20 16:55 ` Pablo Neira Ayuso [this message]
2023-04-20 16:55 ` [PATCH nf-next,v5 3/7] netfilter: nf_tables: rename function to destroy hook list Pablo Neira Ayuso
2023-04-20 16:56 ` [PATCH nf-next,v5 4/7] netfilter: nf_tables: support for adding new devices to an existing netdev chain Pablo Neira Ayuso
2023-04-20 16:56 ` [PATCH nf-next,v5 5/7] netfilter: nf_tables: support for deleting devices in " Pablo Neira Ayuso
2023-04-20 16:56 ` [PATCH nf-next,v5 6/7] netfilter: nf_tables: allow to create netdev chain without device Pablo Neira Ayuso
2023-04-20 16:56 ` [PATCH nf-next,v5 7/7] netfilter: nf_tables: remove artificial cap on maximum number of netdevices Pablo Neira Ayuso
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