Re: [PATCH bpf-next 2/2] bpf: extend bind v4/v6 selftests for mark/prio/bindtoifindex

[Daniel Borkmann]

On 1/11/21 9:15 PM, Yonghong Song wrote:

On 1/11/21 8:17 AM, Daniel Borkmann wrote:

Extend existing cgroup bind4/bind6 tests to add coverage for setting and
retrieving SO_MARK, SO_PRIORITY and SO_BINDTOIFINDEX at the bind hook.

Signed-off-by: Daniel Borkmann <dan...@iogearbox.net>

Ack with a minor comments below.

Acked-by: Yonghong Song <y...@fb.com>

---
  .../testing/selftests/bpf/progs/bind4_prog.c  | 41 +++++++++++++++++--
  .../testing/selftests/bpf/progs/bind6_prog.c  | 41 +++++++++++++++++--
  2 files changed, 74 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/bind4_prog.c 
b/tools/testing/selftests/bpf/progs/bind4_prog.c
index c6520f21f5f5..4479ac27b1d3 100644
--- a/tools/testing/selftests/bpf/progs/bind4_prog.c
+++ b/tools/testing/selftests/bpf/progs/bind4_prog.c
@@ -29,18 +29,47 @@ static __inline int bind_to_device(struct bpf_sock_addr 
*ctx)
      char veth2[IFNAMSIZ] = "test_sock_addr2";
      char missing[IFNAMSIZ] = "nonexistent_dev";
      char del_bind[IFNAMSIZ] = "";
+    int veth1_idx, veth2_idx;
      if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-                &veth1, sizeof(veth1)))
+               &veth1, sizeof(veth1)))
+        return 1;
+    if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+               &veth1_idx, sizeof(veth1_idx)) || !veth1_idx)
          return 1;
      if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-                &veth2, sizeof(veth2)))
+               &veth2, sizeof(veth2)))
+        return 1;
+    if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+               &veth2_idx, sizeof(veth2_idx)) || !veth2_idx ||
+        veth1_idx == veth2_idx)
          return 1;
      if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-                &missing, sizeof(missing)) != -ENODEV)
+               &missing, sizeof(missing)) != -ENODEV)
+        return 1;
+    if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+               &veth1_idx, sizeof(veth1_idx)))
          return 1;
      if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-                &del_bind, sizeof(del_bind)))
+               &del_bind, sizeof(del_bind)))
+        return 1;
+
+    return 0;
+}
+
+static __inline int misc_opts(struct bpf_sock_addr *ctx, int opt)
+{
+    int old, tmp, new = 0xeb9f;
+
+    if (bpf_getsockopt(ctx, SOL_SOCKET, opt, &old, sizeof(old)) ||
+        old == new)
+        return 1;

Here, we assume old never equals to new. it would be good to add
a comment to explicitly state this is true. Maybe in the future
somebody will try to add more misc_opts which might have conflict
here.

I thought it's obvious, but yes I can add a comment.

Alternatively, you could pass in "new" values
from user space with global variables for each option,
but that may be an overkill.

Agree, that's overkill.

Thanks,
Daniel