kevin/linux
1
Fork 0
Code

netfilter: ctnetlink: compile ctnetlink_label_size with CONFIG_NF_CONNTRACK_EVENTS

Browse Source 
Only provide ctnetlink_label_size when it is used,
which is when CONFIG_NF_CONNTRACK_EVENTS is configured.

Flagged by clang-18 W=1 builds as:

.../nf_conntrack_netlink.c:385:19: warning: unused function 'ctnetlink_label_size' [-Wunused-function]
  385 | static inline int ctnetlink_label_size(const struct nf_conn *ct)
      |                   ^~~~~~~~~~~~~~~~~~~~

The condition on CONFIG_NF_CONNTRACK_LABELS being removed by
this patch guards compilation of non-trivial implementations
of ctnetlink_dump_labels() and ctnetlink_label_size().

However, this is not necessary as each of these functions
will always return 0 if CONFIG_NF_CONNTRACK_LABELS is not defined
as each function starts with the equivalent of:

	struct nf_conn_labels *labels = nf_ct_labels_find(ct);

	if (!labels)
		return 0;

And nf_ct_labels_find always returns NULL if CONFIG_NF_CONNTRACK_LABELS
is not enabled.  So I believe that the compiler optimises the code away
in such cases anyway.

Found by inspection.
Compile tested only.

Originally splitted in two patches, Pablo Neira Ayuso collapsed them and
added Fixes: tag.

Fixes: 0ceabd8387 ("netfilter: ctnetlink: deliver labels to userspace")
Link: https://lore.kernel.org/netfilter-devel/20240909151712.GZ2097826@kernel.org/
Signed-off-by: Simon Horman <horms@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Simon Horman 2024-09-16 16:14:41 +01:00 committed by Pablo Neira Ayuso
parent fc56878ca1
commit e1f1ee0e9a
1 changed files with 2 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
net/netfilter/nf_conntrack_netlink.c
View File

@ -382,7 +382,7 @@ nla_put_failure:
#define ctnetlink_dump_secctx(a, b) (0)
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
#ifdef CONFIG_NF_CONNTRACK_EVENTS
static inline int ctnetlink_label_size(const struct nf_conn *ct)
{
struct nf_conn_labels *labels = nf_ct_labels_find(ct);
@ -391,6 +391,7 @@ static inline int ctnetlink_label_size(const struct nf_conn *ct)
return 0;
return nla_total_size(sizeof(labels->bits));
}
#endif
static int
ctnetlink_dump_labels(struct sk_buff *skb, const struct nf_conn *ct)
@ -411,10 +412,6 @@ ctnetlink_dump_labels(struct sk_buff *skb, const struct nf_conn *ct)
return 0;
}
#else
#define ctnetlink_dump_labels(a, b) (0)
#define ctnetlink_label_size(a) (0)
#endif
#define master_tuple(ct) &(ct->master->tuplehash[IP_CT_DIR_ORIGINAL].tuple)