diff mbox series

[v2,bpf-next,2/5] libbpf: add bpf_link detach APIs

Message ID 20200731182830.286260-3-andriin@fb.com
State Accepted
Delegated to: BPF Maintainers
Headers show
Series BPF link force-detach support | expand

Commit Message

Andrii Nakryiko July 31, 2020, 6:28 p.m. UTC 
Add low-level bpf_link_detach() API. Also add higher-level bpf_link__detach()
one.

Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
 tools/include/uapi/linux/bpf.h |  5 +++++
 tools/lib/bpf/bpf.c            | 10 ++++++++++
 tools/lib/bpf/bpf.h            |  2 ++
 tools/lib/bpf/libbpf.c         |  5 +++++
 tools/lib/bpf/libbpf.h         |  1 +
 tools/lib/bpf/libbpf.map       |  2 ++
 6 files changed, 25 insertions(+)

Comments

John Fastabend July 31, 2020, 11:22 p.m. UTC | #1 
Andrii Nakryiko wrote:
> Add low-level bpf_link_detach() API. Also add higher-level bpf_link__detach()
> one.
> 
> Acked-by: Song Liu <songliubraving@fb.com>
> Signed-off-by: Andrii Nakryiko <andriin@fb.com>
> ---

I like it nice and straightforward.

Acked-by: John Fastabend <john.fastabend@gmail.com>
diff mbox series

Patch

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index eb5e0c38eb2c..b134e679e9db 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -117,6 +117,7 @@  enum bpf_cmd {
 	BPF_LINK_GET_NEXT_ID,
 	BPF_ENABLE_STATS,
 	BPF_ITER_CREATE,
+	BPF_LINK_DETACH,
 };
 
 enum bpf_map_type {
@@ -634,6 +635,10 @@  union bpf_attr {
 		__u32		old_prog_fd;
 	} link_update;
 
+	struct {
+		__u32		link_fd;
+	} link_detach;
+
 	struct { /* struct used by BPF_ENABLE_STATS command */
 		__u32		type;
 	} enable_stats;
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index e1bdf214f75f..eab14c97c15d 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -603,6 +603,16 @@  int bpf_link_create(int prog_fd, int target_fd,
 	return sys_bpf(BPF_LINK_CREATE, &attr, sizeof(attr));
 }
 
+int bpf_link_detach(int link_fd)
+{
+	union bpf_attr attr;
+
+	memset(&attr, 0, sizeof(attr));
+	attr.link_detach.link_fd = link_fd;
+
+	return sys_bpf(BPF_LINK_DETACH, &attr, sizeof(attr));
+}
+
 int bpf_link_update(int link_fd, int new_prog_fd,
 		    const struct bpf_link_update_opts *opts)
 {
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 6d367e01d05e..28855fd5b5f4 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -178,6 +178,8 @@  LIBBPF_API int bpf_link_create(int prog_fd, int target_fd,
 			       enum bpf_attach_type attach_type,
 			       const struct bpf_link_create_opts *opts);
 
+LIBBPF_API int bpf_link_detach(int link_fd);
+
 struct bpf_link_update_opts {
 	size_t sz; /* size of this struct for forward/backward compatibility */
 	__u32 flags;	   /* extra flags */
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index b9f11f854985..7be04e45d29c 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -7748,6 +7748,11 @@  struct bpf_link *bpf_link__open(const char *path)
 	return link;
 }
 
+int bpf_link__detach(struct bpf_link *link)
+{
+	return bpf_link_detach(link->fd) ? -errno : 0;
+}
+
 int bpf_link__pin(struct bpf_link *link, const char *path)
 {
 	int err;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 9924385462ab..3ed1399bfbbc 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -229,6 +229,7 @@  LIBBPF_API int bpf_link__unpin(struct bpf_link *link);
 LIBBPF_API int bpf_link__update_program(struct bpf_link *link,
 					struct bpf_program *prog);
 LIBBPF_API void bpf_link__disconnect(struct bpf_link *link);
+LIBBPF_API int bpf_link__detach(struct bpf_link *link);
 LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
 
 LIBBPF_API struct bpf_link *
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index ca49a6a7e5b2..099863411f7d 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -273,6 +273,8 @@  LIBBPF_0.0.9 {
 
 LIBBPF_0.1.0 {
 	global:
+		bpf_link__detach;
+		bpf_link_detach;
 		bpf_map__ifindex;
 		bpf_map__key_size;
 		bpf_map__map_flags;