From: Roman Gushchin <[email protected]>
Introduce bpf_map__attach_struct_ops_opts(), an extended version of
bpf_map__attach_struct_ops(), which takes additional struct
bpf_struct_ops_opts argument.
This allows to pass a target_fd argument and the BPF_F_CGROUP_FD flag
and attach the struct ops to a cgroup as a result.
Signed-off-by: Roman Gushchin <[email protected]>
---
tools/lib/bpf/libbpf.c | 20 +++++++++++++++++---
tools/lib/bpf/libbpf.h | 14 ++++++++++++++
tools/lib/bpf/libbpf.map | 1 +
3 files changed, 32 insertions(+), 3 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 1e8688975d16..a1b54da1ded2 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -13683,11 +13683,18 @@ static int bpf_link__detach_struct_ops(struct
bpf_link *link)
return close(link->fd);
}
-struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map)
+struct bpf_link *bpf_map__attach_struct_ops_opts(const struct bpf_map *map,
+ const struct
bpf_struct_ops_opts *opts)
{
+ DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_opts);
struct bpf_link_struct_ops *link;
+ int err, fd, target_fd;
__u32 zero = 0;
- int err, fd;
+
+ if (!OPTS_VALID(opts, bpf_struct_ops_opts)) {
+ pr_warn("map '%s': invalid opts\n", map->name);
+ return libbpf_err_ptr(-EINVAL);
+ }
if (!bpf_map__is_struct_ops(map)) {
pr_warn("map '%s': can't attach non-struct_ops map\n",
map->name);
@@ -13724,7 +13731,9 @@ struct bpf_link *bpf_map__attach_struct_ops(const
struct bpf_map *map)
return &link->link;
}
- fd = bpf_link_create(map->fd, 0, BPF_STRUCT_OPS, NULL);
+ link_opts.flags = OPTS_GET(opts, flags, 0);
+ target_fd = OPTS_GET(opts, target_fd, 0);
+ fd = bpf_link_create(map->fd, target_fd, BPF_STRUCT_OPS, &link_opts);
if (fd < 0) {
free(link);
return libbpf_err_ptr(fd);
@@ -13736,6 +13745,11 @@ struct bpf_link *bpf_map__attach_struct_ops(const
struct bpf_map *map)
return &link->link;
}
+struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map)
+{
+ return bpf_map__attach_struct_ops_opts(map, NULL);
+}
+
/*
* Swap the back struct_ops of a link with a new struct_ops map.
*/
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index bba4e8464396..18af178547ad 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -945,6 +945,20 @@ bpf_program__attach_cgroup_opts(const struct bpf_program
*prog, int cgroup_fd,
struct bpf_map;
LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
+
+struct bpf_struct_ops_opts {
+ /* size of this struct, for forward/backward compatibility */
+ size_t sz;
+ __u32 flags;
+ __u32 target_fd;
+ __u64 expected_revision;
+ size_t :0;
+};
+#define bpf_struct_ops_opts__last_field expected_revision
+
+LIBBPF_API struct bpf_link *
+bpf_map__attach_struct_ops_opts(const struct bpf_map *map,
+ const struct bpf_struct_ops_opts *opts);
LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct
bpf_map *map);
struct bpf_iter_attach_opts {
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index dfed8d60af05..6105619b5ecf 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -454,6 +454,7 @@ LIBBPF_1.7.0 {
bpf_prog_assoc_struct_ops;
bpf_program__assoc_struct_ops;
btf__permute;
+ bpf_map__attach_struct_ops_opts;
