Re: [PATCH v3 6/8] socket: Add SO_TIMESTAMP[NS]_NEW

[Willem de Bruijn]

On Mon, Jan 7, 2019 at 10:29 PM Deepa Dinamani <deepa.kernel@xxxxxxxxx> wrote:
>
> Add SO_TIMESTAMP_NEW and SO_TIMESTAMPNS_NEW variants of
> socket timestamp options.
> These are the y2038 safe versions of the SO_TIMESTAMP_OLD
> and SO_TIMESTAMPNS_OLD for all architectures.
>
> Note that the format of scm_timestamping.ts[0] is not changed
> in this patch.
>
> Signed-off-by: Deepa Dinamani <deepa.kernel@xxxxxxxxx>
> Cc: jejb@xxxxxxxxxxxxxxxx
> Cc: ralf@xxxxxxxxxxxxxx
> Cc: rth@xxxxxxxxxxx
> Cc: linux-alpha@xxxxxxxxxxxxxxx
> Cc: linux-mips@xxxxxxxxxxxxxx
> Cc: linux-parisc@xxxxxxxxxxxxxxx
> Cc: linux-rdma@xxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: sparclinux@xxxxxxxxxxxxxxx

> diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
> index 00e45c80e574..352e3dc0b3d9 100644
> --- a/arch/alpha/include/uapi/asm/socket.h
> +++ b/arch/alpha/include/uapi/asm/socket.h
> @@ -3,6 +3,7 @@
>  #define _UAPI_ASM_SOCKET_H
>
>  #include <asm/sockios.h>
> +#include <asm/bitsperlong.h>
>
>  /* For setsockopt(2) */
>  /*
> @@ -110,12 +111,22 @@
>
>  #define SO_TIMESTAMP_OLD         29
>  #define SO_TIMESTAMPNS_OLD       35
> +

nit: unnecessary whitespace line

> @@ -1864,20 +1864,39 @@ static void tcp_update_recv_tstamps(struct sk_buff *skb,
>  static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
>                                struct scm_timestamping *tss)
>  {
> -       struct __kernel_old_timeval tv;
>         bool has_timestamping = false;
> +       int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
>
>         if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) {
>                 if (sock_flag(sk, SOCK_RCVTSTAMP)) {
>                         if (sock_flag(sk, SOCK_RCVTSTAMPNS)) {
> -                               put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
> -                                        sizeof(tss->ts[0]), &tss->ts[0]);
> -                       } else {
> -                               tv.tv_sec = tss->ts[0].tv_sec;
> -                               tv.tv_usec = tss->ts[0].tv_nsec / 1000;
> +                               if (new_tstamp) {
> +                                       struct __kernel_timespec kts = {tss->ts[0].tv_sec, tss->ts[0].tv_nsec};
> +
> +                                       put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
> +                                                sizeof(kts), &kts);
> +                               } else {
> +                                       struct timespec ts_old = tss->ts[0];

nit: intermediate variable not needed as tss->ts[0] is also of type
struct timespec.