Add a new API to pin a BPF object to the filesystem. The user can
specify the path full path within a BPF filesystem to pin the object.
Programs will be pinned under a subdirectory 'progs', and maps will be
pinned under a subdirectory 'maps'.
For example, with the directory '/sys/fs/bpf/foo':
/sys/fs/bpf/foo/progs/PROG_NAME
/sys/fs/bpf/foo/maps/MAP_NAME
Signed-off-by: Joe Stringer <j...@ovn.org>
---
v2: Don't automount BPF filesystem
Split program, map, object pinning into separate APIs and separate
patches.
---
tools/lib/bpf/libbpf.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++
tools/lib/bpf/libbpf.h | 1 +
2 files changed, 74 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index c1d8b07e21d2..41645dc51fa1 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -36,6 +36,7 @@
#include <linux/magic.h>
#include <linux/list.h>
#include <linux/limits.h>
+#include <sys/stat.h>
#include <sys/vfs.h>
#include <libelf.h>
#include <gelf.h>
@@ -1335,6 +1336,78 @@ int bpf_map__pin(struct bpf_map *map, const char *path)
return 0;
}
+static int make_dir(const char *path, const char *dir)
+{
+ char buf[PATH_MAX];
+ int len, err = 0;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path, dir);
+ if (len < 0)
+ err = -EINVAL;
+ else if (len >= PATH_MAX)
+ err = -ENAMETOOLONG;
+ if (!err && mkdir(buf, 0700) && errno != EEXIST)
+ err = -errno;
+
+ if (err)
+ pr_warning("failed to make dir %s/%s: %s\n", path, dir,
+ strerror(-err));
+ return err;
+}
+
+int bpf_object__pin(struct bpf_object *obj, const char *path)
+{
+ struct bpf_program *prog;
+ struct bpf_map *map;
+ int err;
+
+ if (!obj)
+ return -ENOENT;
+
+ if (!obj->loaded) {
+ pr_warning("object not yet loaded; load it first\n");
+ return -ENOENT;
+ }
+
+ err = make_dir(path, "maps");
+ if (err)
+ return err;
+
+ bpf_map__for_each(map, obj) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/maps/%s", path,
+ bpf_map__name(map));
+ if (len < 0 || len > PATH_MAX)
+ return -EINVAL;
+
+ err = bpf_map__pin(map, buf);
+ if (err)
+ return err;
+ }
+
+ err = make_dir(path, "progs");
+ if (err)
+ return err;
+
+ bpf_object__for_each_program(prog, obj) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/progs/%s", path,
+ prog->section_name);
+ if (len < 0 || len > PATH_MAX)
+ return -EINVAL;
+
+ err = bpf_program__pin(prog, buf);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
void bpf_object__close(struct bpf_object *obj)
{
size_t i;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 524247cfd205..8363ee6db4a0 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -65,6 +65,7 @@ struct bpf_object *bpf_object__open(const char *path);
struct bpf_object *bpf_object__open_buffer(void *obj_buf,
size_t obj_buf_sz,
const char *name);
+int bpf_object__pin(struct bpf_object *object, const char *path);
void bpf_object__close(struct bpf_object *object);
/* Load/unload object into/from kernel */
--
2.11.0
