Introduce a new bpf_prog_attach_xattr function that accepts an
extendable structure and supports passing a new attribute to
BPF_PROG_ATTACH command: replace_prog_fd that is fd of previously
attached cgroup-bpf program to replace if recently introduced
BPF_F_REPLACE flag is used.
The new function is named to be consistent with other xattr-functions
(bpf_prog_test_run_xattr, bpf_create_map_xattr, bpf_load_program_xattr).
NOTE: DECLARE_LIBBPF_OPTS macro is not used here because it's available
in libbpf.h, and unavailable in bpf.h. Please let me know if the macro
should be shared in a common place and used here instead of declaring
struct bpf_prog_attach_attr directly.
Signed-off-by: Andrey Ignatov <rdna@xxxxxx>
---
tools/lib/bpf/bpf.c | 22 ++++++++++++++++++----
tools/lib/bpf/bpf.h | 10 ++++++++++
tools/lib/bpf/libbpf.map | 5 +++++
3 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 98596e15390f..5a2830fac227 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -466,14 +466,28 @@ int bpf_obj_get(const char *pathname)
int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
unsigned int flags)
+{
+ struct bpf_prog_attach_attr attach_attr;
+
+ memset(&attach_attr, 0, sizeof(attach_attr));
+ attach_attr.target_fd = target_fd;
+ attach_attr.prog_fd = prog_fd;
+ attach_attr.type = type;
+ attach_attr.flags = flags;
+
+ return bpf_prog_attach_xattr(&attach_attr);
+}
+
+int bpf_prog_attach_xattr(const struct bpf_prog_attach_attr *attach_attr)
{
union bpf_attr attr;
memset(&attr, 0, sizeof(attr));
- attr.target_fd = target_fd;
- attr.attach_bpf_fd = prog_fd;
- attr.attach_type = type;
- attr.attach_flags = flags;
+ attr.target_fd = attach_attr->target_fd;
+ attr.attach_bpf_fd = attach_attr->prog_fd;
+ attr.attach_type = attach_attr->type;
+ attr.attach_flags = attach_attr->flags;
+ attr.replace_bpf_fd = attach_attr->replace_prog_fd;
return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr));
}
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 3c791fa8e68e..4b7269d3bae7 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -128,8 +128,18 @@ LIBBPF_API int bpf_map_get_next_key(int fd, const void *key, void *next_key);
LIBBPF_API int bpf_map_freeze(int fd);
LIBBPF_API int bpf_obj_pin(int fd, const char *pathname);
LIBBPF_API int bpf_obj_get(const char *pathname);
+
+struct bpf_prog_attach_attr {
+ int target_fd;
+ int prog_fd;
+ enum bpf_attach_type type;
+ unsigned int flags;
+ int replace_prog_fd;
+};
+
LIBBPF_API int bpf_prog_attach(int prog_fd, int attachable_fd,
enum bpf_attach_type type, unsigned int flags);
+LIBBPF_API int bpf_prog_attach_xattr(const struct bpf_prog_attach_attr *attr);
LIBBPF_API int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
LIBBPF_API int bpf_prog_detach2(int prog_fd, int attachable_fd,
enum bpf_attach_type type);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 8ddc2c40e482..42b065454031 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -208,3 +208,8 @@ LIBBPF_0.0.6 {
btf__find_by_name_kind;
libbpf_find_vmlinux_btf_id;
} LIBBPF_0.0.5;
+
+LIBBPF_0.0.7 {
+ global:
+ bpf_prog_attach_xattr;
+} LIBBPF_0.0.6;
--
2.17.1
