[PATCH bpf-next 4/4] bpftool: use libbpf_[get|put]_bpf_permission()

[Song Liu]

This patch calls libbpf_[get|put]_bpf_permission() from bpftool. This
allows users with access to /dev/bpf to perform operations like root.

Signed-off-by: Song Liu <songliubrav...@fb.com>
---
 tools/bpf/bpftool/feature.c | 2 +-
 tools/bpf/bpftool/main.c    | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/bpf/bpftool/feature.c b/tools/bpf/bpftool/feature.c
index d672d9086fff..f7f43b91ce96 100644
--- a/tools/bpf/bpftool/feature.c
+++ b/tools/bpf/bpftool/feature.c
@@ -583,7 +583,7 @@ static int do_probe(int argc, char **argv)
        /* Detection assumes user has sufficient privileges (CAP_SYS_ADMIN).
         * Let's approximate, and restrict usage to root user only.
         */
-       if (geteuid()) {
+       if (!libbpf_get_bpf_permission()) {
                p_err("please run this command as root user");
                return -1;
        }
diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c
index 4879f6395c7e..f9146d7d8fc5 100644
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -390,6 +390,10 @@ int main(int argc, char **argv)
        if (argc < 0)
                usage();
 
+       if (!libbpf_get_bpf_permission()) {
+               p_err("cannot get permission to access bpf() syscall");
+               usage();
+       }
        ret = cmd_select(cmds, argc, argv, do_help);
 
        if (json_output)
@@ -400,5 +404,6 @@ int main(int argc, char **argv)
                delete_pinned_obj_table(&map_table);
        }
 
+       libbpf_put_bpf_permission();
        return ret;
 }
-- 
2.17.1