Re: [PATCH 4/8] tools lib bpf: export function to set type

[Wangnan (F)]

On 2016/10/17 5:18, Eric Leblond wrote:

Current API was not allowing the user to set a type like socket
filter. To avoid a setter function for each type, the patch simply
exports a set function that takes the type in parameter.

Signed-off-by: Eric Leblond <e...@regit.org>
---
  tools/lib/bpf/libbpf.c | 19 +++++++++----------
  tools/lib/bpf/libbpf.h |  3 +++
  2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 90932f1..7cd341e 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1336,26 +1336,25 @@ int bpf_program__nth_fd(struct bpf_program *prog, int n)
        return fd;
  }

-static void bpf_program__set_type(struct bpf_program *prog,

-                                 enum bpf_prog_type type)
+int bpf_program__set_type(struct bpf_program *prog, unsigned int type)
  {
+       if (!prog)
+               return -EINVAL;
+       if (type >= __MAX_BPF_PROG_TYPE)
+               return -EINVAL;
+
        prog->type = type;
+       return 0;
  }

int bpf_program__set_tracepoint(struct bpf_program *prog)

  {
-       if (!prog)
-               return -EINVAL;
-       bpf_program__set_type(prog, BPF_PROG_TYPE_TRACEPOINT);
-       return 0;
+       return bpf_program__set_type(prog, BPF_PROG_TYPE_TRACEPOINT);
  }

int bpf_program__set_kprobe(struct bpf_program *prog)

  {
-       if (!prog)
-               return -EINVAL;
-       bpf_program__set_type(prog, BPF_PROG_TYPE_KPROBE);
-       return 0;
+       return bpf_program__set_type(prog, BPF_PROG_TYPE_KPROBE);
  }

static bool bpf_program__is_type(struct bpf_program *prog,

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index e40c8d3..a18783b 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -173,6 +173,9 @@ int bpf_program__set_kprobe(struct bpf_program *prog);
  bool bpf_program__is_tracepoint(struct bpf_program *prog);
  bool bpf_program__is_kprobe(struct bpf_program *prog);

+int bpf_program__set_type(struct bpf_program *prog,

+                                 unsigned int type);
+

Although you don't include uapi/linux/bpf.h in this patch, logically
you add this dependency.

Please continously add bpf_program__set_socket_filter() and
bpf_program__is_socket_filter() like what we do for tracepoint.
This way libbpf.h is indenpendent from kernel header.

We can use macro in both .h and .c.

Thank you.