diff mbox series

[nf-next,5/6] netfilter: nf_tables: nft_obj_filter fits into cb->ctx

Message ID 20231020173433.4611-6-phil@nwl.cc
State Accepted, archived
Headers show
Series Refactor nft_obj_filter into nft_obj_dump_ctx | expand

Commit Message

Phil Sutter Oct. 20, 2023, 5:34 p.m. UTC 
No need to allocate it if one may just use struct netlink_callback's
scratch area for it.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 net/netfilter/nf_tables_api.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)
diff mbox series

Patch

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index a6877544f936..9523f1f3a598 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -7698,7 +7698,7 @@  struct nft_obj_dump_ctx {
 static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	const struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
-	struct nft_obj_dump_ctx *ctx = cb->data;
+	struct nft_obj_dump_ctx *ctx = (void *)cb->ctx;
 	struct net *net = sock_net(skb->sk);
 	int family = nfmsg->nfgen_family;
 	struct nftables_pernet *nft_net;
@@ -7760,34 +7760,28 @@  static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb)
 
 static int nf_tables_dump_obj_start(struct netlink_callback *cb)
 {
+	struct nft_obj_dump_ctx *ctx = (void *)cb->ctx;
 	const struct nlattr * const *nla = cb->data;
-	struct nft_obj_dump_ctx *ctx = NULL;
 
-	ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);
-	if (!ctx)
-		return -ENOMEM;
+	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
 
 	if (nla[NFTA_OBJ_TABLE]) {
 		ctx->table = nla_strdup(nla[NFTA_OBJ_TABLE], GFP_ATOMIC);
-		if (!ctx->table) {
-			kfree(ctx);
+		if (!ctx->table)
 			return -ENOMEM;
-		}
 	}
 
 	if (nla[NFTA_OBJ_TYPE])
 		ctx->type = ntohl(nla_get_be32(nla[NFTA_OBJ_TYPE]));
 
-	cb->data = ctx;
 	return 0;
 }
 
 static int nf_tables_dump_obj_done(struct netlink_callback *cb)
 {
-	struct nft_obj_dump_ctx *ctx = cb->data;
+	struct nft_obj_dump_ctx *ctx = (void *)cb->ctx;
 
 	kfree(ctx->table);
-	kfree(ctx);
 
 	return 0;
 }