Commit f1674dc7 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Daniel Borkmann
Browse files

libbpf: Add opts-based bpf_obj_pin() API and add support for path_fd 



Add path_fd support for bpf_obj_pin() and bpf_obj_get() operations
(through their opts-based variants). This allows to take advantage of
new kernel-side support for O_PATH-based pin/get location specification.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230523170013.728457-4-andrii@kernel.org
parent cb8edce2

tools/lib/bpf/bpf.c

+14 −3
Original line number Diff line number Diff line
@@ -572,20 +572,30 @@ int bpf_map_update_batch(int fd, const void *keys, const void *values, __u32 *co 
				    (void *)keys, (void *)values, count, opts);

}



int bpf_obj_pin(int fd, const char *pathname)

int bpf_obj_pin_opts(int fd, const char *pathname, const struct bpf_obj_pin_opts *opts)

{

	const size_t attr_sz = offsetofend(union bpf_attr, file_flags);

	const size_t attr_sz = offsetofend(union bpf_attr, path_fd);

	union bpf_attr attr;

	int ret;



	if (!OPTS_VALID(opts, bpf_obj_pin_opts))

		return libbpf_err(-EINVAL);



	memset(&attr, 0, attr_sz);

	attr.path_fd = OPTS_GET(opts, path_fd, 0);

	attr.pathname = ptr_to_u64((void *)pathname);

	attr.file_flags = OPTS_GET(opts, file_flags, 0);

	attr.bpf_fd = fd;



	ret = sys_bpf(BPF_OBJ_PIN, &attr, attr_sz);

	return libbpf_err_errno(ret);

}



int bpf_obj_pin(int fd, const char *pathname)

{

	return bpf_obj_pin_opts(fd, pathname, NULL);

}



int bpf_obj_get(const char *pathname)

{

	return bpf_obj_get_opts(pathname, NULL);
@@ -593,7 +603,7 @@ int bpf_obj_get(const char *pathname) 


int bpf_obj_get_opts(const char *pathname, const struct bpf_obj_get_opts *opts)

{

	const size_t attr_sz = offsetofend(union bpf_attr, file_flags);

	const size_t attr_sz = offsetofend(union bpf_attr, path_fd);

	union bpf_attr attr;

	int fd;
@@ -601,6 +611,7 @@ int bpf_obj_get_opts(const char *pathname, const struct bpf_obj_get_opts *opts) 
		return libbpf_err(-EINVAL);



	memset(&attr, 0, attr_sz);

	attr.path_fd = OPTS_GET(opts, path_fd, 0);

	attr.pathname = ptr_to_u64((void *)pathname);

	attr.file_flags = OPTS_GET(opts, file_flags, 0);

tools/lib/bpf/bpf.h

+16 −2
Original line number Diff line number Diff line
@@ -284,16 +284,30 @@ LIBBPF_API int bpf_map_update_batch(int fd, const void *keys, const void *values 
				    __u32 *count,

				    const struct bpf_map_batch_opts *opts);



struct bpf_obj_get_opts {

struct bpf_obj_pin_opts {

	size_t sz; /* size of this struct for forward/backward compatibility */



	__u32 file_flags;

	int path_fd;



	size_t :0;

};

#define bpf_obj_get_opts__last_field file_flags

#define bpf_obj_pin_opts__last_field path_fd



LIBBPF_API int bpf_obj_pin(int fd, const char *pathname);

LIBBPF_API int bpf_obj_pin_opts(int fd, const char *pathname,

				const struct bpf_obj_pin_opts *opts);



struct bpf_obj_get_opts {

	size_t sz; /* size of this struct for forward/backward compatibility */



	__u32 file_flags;

	int path_fd;



	size_t :0;

};

#define bpf_obj_get_opts__last_field path_fd



LIBBPF_API int bpf_obj_get(const char *pathname);

LIBBPF_API int bpf_obj_get_opts(const char *pathname,

				const struct bpf_obj_get_opts *opts);

tools/lib/bpf/libbpf.map

+2 −0
Original line number Diff line number Diff line
@@ -393,4 +393,6 @@ LIBBPF_1.2.0 { 
} LIBBPF_1.1.0;



LIBBPF_1.3.0 {

	global:

		bpf_obj_pin_opts;

} LIBBPF_1.2.0;