[PATCH] netfilter: bpf: add missing declaration for bpf_ct_set_nat_info

[Sun Jian <sun.jian.kdev@gmail.com>]

When building with Sparse (C=2), the following warning is reported:

net/netfilter/nf_nat_bpf.c:31:17: warning: symbol 'bpf_ct_set_nat_info'
 was not declared. Should it be static?

This function is a BPF kfunc and must remain non-static to be visible
to the BPF verifier via BTF. However, it lacks a proper declaration
in the header file, which triggers the sparse warning.

Fix this by adding the missing declaration in
include/net/netfilter/nf_conntrack_bpf.h inside the CONFIG_NF_NAT
conditional block.

Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
---
 include/net/netfilter/nf_conntrack_bpf.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/net/netfilter/nf_conntrack_bpf.h b/include/net/netfilter/nf_conntrack_bpf.h
index 2d0da478c8e0..25b51fa783c8 100644
--- a/include/net/netfilter/nf_conntrack_bpf.h
+++ b/include/net/netfilter/nf_conntrack_bpf.h
@@ -33,6 +33,9 @@ static inline void cleanup_nf_conntrack_bpf(void)
     (IS_MODULE(CONFIG_NF_NAT) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES))
 
 extern int register_nf_nat_bpf(void);
+int bpf_ct_set_nat_info(struct nf_conn___init *nfct,
+			union nf_inet_addr *addr, int port,
+			enum nf_nat_manip_type manip);
 
 #else
 
-- 
2.43.0