[RFC PATCH bpf-next 6/8] selftests/bpf: Add a new cgroup helper get_classid_cgroup_id()

Yafang Shao
2023-10-07T14:03:28Z

Introduce a new helper function to retrieve the cgroup ID from a net_cls
cgroup directory.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
tools/testing/selftests/bpf/cgroup_helpers.c | 28 +++++++++++++++-----
tools/testing/selftests/bpf/cgroup_helpers.h | 1 +
2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
index e378fa057757..7cb2c9597b8f 100644
--- a/tools/testing/selftests/bpf/cgroup_helpers.c
+++ b/tools/testing/selftests/bpf/cgroup_helpers.c
@@ -417,26 +417,23 @@ int create_and_get_cgroup(const char *relative_path)
}

/**
- * get_cgroup_id() - Get cgroup id for a particular cgroup path
- * @relative_path: The cgroup path, relative to the workdir, to join
+ * get_cgroup_id_from_path - Get cgroup id for a particular cgroup path
+ * @cgroup_workdir: The absolute cgroup path
*
* On success, it returns the cgroup id. On failure it returns 0,
* which is an invalid cgroup id.
* If there is a failure, it prints the error to stderr.
*/
-unsigned long long get_cgroup_id(const char *relative_path)
+unsigned long long get_cgroup_id_from_path(const char *cgroup_workdir)
{
int dirfd, err, flags, mount_id, fhsize;
union {
unsigned long long cgid;
unsigned char raw_bytes[8];
} id;
- char cgroup_workdir[PATH_MAX + 1];
struct file_handle *fhp, *fhp2;
unsigned long long ret = 0;

- format_cgroup_path(cgroup_workdir, relative_path);
-
dirfd = AT_FDCWD;
flags = 0;
fhsize = sizeof(*fhp);
@@ -472,6 +469,14 @@ unsigned long long get_cgroup_id(const char *relative_path)
return ret;
}

+unsigned long long get_cgroup_id(const char *relative_path)
+{
+ char cgroup_workdir[PATH_MAX + 1];
+
+ format_cgroup_path(cgroup_workdir, relative_path);
+ return get_cgroup_id_from_path(cgroup_workdir);
+}
+
int cgroup_setup_and_join(const char *path) {
int cg_fd;

@@ -617,3 +622,14 @@ void cleanup_classid_environment(void)
join_cgroup_from_top(NETCLS_MOUNT_PATH);
nftw(cgroup_workdir, nftwfunc, WALK_FD_LIMIT, FTW_DEPTH | FTW_MOUNT);
}
+
+/**
+ * get_classid_cgroup_id - Get the cgroup id of a net_cls cgroup
+ */
+unsigned long long get_classid_cgroup_id(void)
+{
+ char cgroup_workdir[PATH_MAX + 1];
+
+ format_classid_path(cgroup_workdir);
+ return get_cgroup_id_from_path(cgroup_workdir);
+}
diff --git a/tools/testing/selftests/bpf/cgroup_helpers.h b/tools/testing/selftests/bpf/cgroup_helpers.h
index 92fc41daf4a4..e71da4ef031b 100644
--- a/tools/testing/selftests/bpf/cgroup_helpers.h
+++ b/tools/testing/selftests/bpf/cgroup_helpers.h
@@ -31,6 +31,7 @@ void cleanup_cgroup_environment(void);
/* cgroupv1 related */
int set_classid(void);
int join_classid(void);
+unsigned long long get_classid_cgroup_id(void);

int setup_classid_environment(void);
void cleanup_classid_environment(void);
--
2.30.1 (Apple Git-130)