Merge branch 'bpf: Small nf_conn cleanups'

Daniel Xu says:

====================

This patchset cleans up a few small things:

* Delete unused stub
* Rename variable to be more descriptive
* Fix some `extern` declaration warnings

Past discussion:
- v2: https://lore.kernel.org/bpf/cover.1663616584.git.dxu@dxuuu.xyz/

Changes since v2:
- Remove unused #include's
- Move #include <linux/filter.h> to .c
====================
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

include/linux/filter.h

@@ -567,6 +567,12 @@ struct sk_filter {
 
 DECLARE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
 
+extern struct mutex nf_conn_btf_access_lock;
+extern int (*nfct_btf_struct_access)(struct bpf_verifier_log *log, const struct btf *btf,
+				     const struct btf_type *t, int off, int size,
+				     enum bpf_access_type atype, u32 *next_btf_id,
+				     enum bpf_type_flag *flag);
+
 typedef unsigned int (*bpf_dispatcher_fn)(const void *ctx,
 					  const struct bpf_insn *insnsi,
 					  unsigned int (*bpf_func)(const void *,

include/net/netfilter/nf_conntrack_bpf.h

@@ -3,10 +3,7 @@
 #ifndef _NF_CONNTRACK_BPF_H
 #define _NF_CONNTRACK_BPF_H
 
-#include <linux/bpf.h>
-#include <linux/btf.h>
 #include <linux/kconfig.h>
-#include <linux/mutex.h>
 
 #if (IS_BUILTIN(CONFIG_NF_CONNTRACK) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) || \
     (IS_MODULE(CONFIG_NF_CONNTRACK) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES))
@@ -14,12 +11,6 @@
 extern int register_nf_conntrack_bpf(void);
 extern void cleanup_nf_conntrack_bpf(void);
 
-extern struct mutex nf_conn_btf_access_lock;
-extern int (*nfct_bsa)(struct bpf_verifier_log *log, const struct btf *btf,
-		       const struct btf_type *t, int off, int size,
-		       enum bpf_access_type atype, u32 *next_btf_id,
-		       enum bpf_type_flag *flag);
-
 #else
 
 static inline int register_nf_conntrack_bpf(void)
@@ -31,16 +22,6 @@ static inline void cleanup_nf_conntrack_bpf(void)
 {
 }
 
-static inline int nf_conntrack_btf_struct_access(struct bpf_verifier_log *log,
-						 const struct btf *btf,
-						 const struct btf_type *t, int off,
-						 int size, enum bpf_access_type atype,
-						 u32 *next_btf_id,
-						 enum bpf_type_flag *flag)
-{
-	return -EACCES;
-}
-
 #endif
 
 #endif /* _NF_CONNTRACK_BPF_H */

net/core/filter.c

@@ -8608,11 +8608,11 @@ static bool tc_cls_act_is_valid_access(int off, int size,
 DEFINE_MUTEX(nf_conn_btf_access_lock);
 EXPORT_SYMBOL_GPL(nf_conn_btf_access_lock);
 
-int (*nfct_bsa)(struct bpf_verifier_log *log, const struct btf *btf,
+int (*nfct_btf_struct_access)(struct bpf_verifier_log *log, const struct btf *btf,
 			      const struct btf_type *t, int off, int size,
 			      enum bpf_access_type atype, u32 *next_btf_id,
 			      enum bpf_type_flag *flag);
-EXPORT_SYMBOL_GPL(nfct_bsa);
+EXPORT_SYMBOL_GPL(nfct_btf_struct_access);
 
 static int tc_cls_act_btf_struct_access(struct bpf_verifier_log *log,
 					const struct btf *btf,
@@ -8628,8 +8628,8 @@ static int tc_cls_act_btf_struct_access(struct bpf_verifier_log *log,
 					 flag);
 
 	mutex_lock(&nf_conn_btf_access_lock);
-	if (nfct_bsa)
-		ret = nfct_bsa(log, btf, t, off, size, atype, next_btf_id, flag);
+	if (nfct_btf_struct_access)
+		ret = nfct_btf_struct_access(log, btf, t, off, size, atype, next_btf_id, flag);
 	mutex_unlock(&nf_conn_btf_access_lock);
 
 	return ret;
@@ -8708,8 +8708,8 @@ static int xdp_btf_struct_access(struct bpf_verifier_log *log,
 					 flag);
 
 	mutex_lock(&nf_conn_btf_access_lock);
-	if (nfct_bsa)
-		ret = nfct_bsa(log, btf, t, off, size, atype, next_btf_id, flag);
+	if (nfct_btf_struct_access)
+		ret = nfct_btf_struct_access(log, btf, t, off, size, atype, next_btf_id, flag);
 	mutex_unlock(&nf_conn_btf_access_lock);
 
 	return ret;

net/netfilter/nf_conntrack_bpf.c

@@ -9,6 +9,7 @@
 #include <linux/bpf_verifier.h>
 #include <linux/bpf.h>
 #include <linux/btf.h>
+#include <linux/filter.h>
 #include <linux/mutex.h>
 #include <linux/types.h>
 #include <linux/btf_ids.h>
@@ -502,7 +503,7 @@ int register_nf_conntrack_bpf(void)
 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &nf_conntrack_kfunc_set);
 	if (!ret) {
 		mutex_lock(&nf_conn_btf_access_lock);
-		nfct_bsa = _nf_conntrack_btf_struct_access;
+		nfct_btf_struct_access = _nf_conntrack_btf_struct_access;
 		mutex_unlock(&nf_conn_btf_access_lock);
 	}
 
@@ -512,6 +513,6 @@ int register_nf_conntrack_bpf(void)
 void cleanup_nf_conntrack_bpf(void)
 {
 	mutex_lock(&nf_conn_btf_access_lock);
-	nfct_bsa = NULL;
+	nfct_btf_struct_access = NULL;
 	mutex_unlock(&nf_conn_btf_access_lock);
 }