Re: [PATCH net-next v2 02/12] net-timestamp: open gate for bpf_setsockopt

Jason Xing wrote:

On Wed, Oct 16, 2024 at 5:56 AM Willem de Bruijn
[off-list ref] wrote:

quoted

Martin KaFai Lau wrote:

quoted

On 10/11/24 9:06 PM, Jason Xing wrote:

quoted

  static int sol_socket_sockopt(struct sock *sk, int optname,
                          char *optval, int *optlen,
                          bool getopt)
  {
+   struct so_timestamping ts;
+   int ret = 0;
+
    switch (optname) {
    case SO_REUSEADDR:
    case SO_SNDBUF:

@@ -5225,6 +5245,13 @@ static int sol_socket_sockopt(struct sock *sk, int optname,
            break;
    case SO_BINDTODEVICE:
            break;
+   case SO_TIMESTAMPING_NEW:
+   case SO_TIMESTAMPING_OLD:

How about remove the "_OLD" support ?

+1 I forgot to mention that yesterday.

Hello Willem, Martin,

I did a test on this and found that if we only use
SO_TIMESTAMPING_NEW, we will never enter the real set sk_tsflags_bpf
logic, unless there is "case SO_TIMESTAMPING_OLD".

And I checked SO_TIMESTAMPING in include/uapi/asm-generic/socket.h:
#if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__))
/* on 64-bit and x32, avoid the ?: operator */
...
#define SO_TIMESTAMPING         SO_TIMESTAMPING_OLD
...
#else
...
#define SO_TIMESTAMPING (sizeof(time_t) == sizeof(__kernel_long_t) ?
SO_TIMESTAMPING_OLD : SO_TIMESTAMPING_NEW)
...
#endif

The SO_TIMESTAMPING is defined as SO_TIMESTAMPING_OLD. I wonder if I
missed something? Thanks in advance.

The _NEW vs _OLD aim to deal with y2038 issues on 32-bit platforms.

For new APIs, like BPF timestamping, we should always use the safe
structs, such as timespec64.

Then we can just use SO_TIMESTAMPING without the NEW or OLD suffix.