[NET]: Introduce SIOCGSTAMPNS ioctl to get timestamps with nanosec resolution

Now network timestamps use ktime_t infrastructure, we can add a new
ioctl() SIOCGSTAMPNS command to get timestamps in 'struct timespec'.
User programs can thus access to nanosecond resolution.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
CC: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 24 insertions, 0 deletions

diff --git a/net/compat.c b/net/compat.c
index 17c2710b2b93..2fc6d9bb622b 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -564,6 +564,30 @@ int compat_sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
 }
 EXPORT_SYMBOL(compat_sock_get_timestamp);
 
+int compat_sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
+{
+        struct compat_timespec __user *ctv =
+                        (struct compat_timespec __user*) userstamp;
+        int err = -ENOENT;
+        struct timespec ts;
+
+        if (!sock_flag(sk, SOCK_TIMESTAMP))
+                sock_enable_timestamp(sk);
+        ts = ktime_to_timespec(sk->sk_stamp);
+        if (ts.tv_sec == -1)
+                return err;
+        if (ts.tv_sec == 0) {
+                sk->sk_stamp = ktime_get_real();
+                ts = ktime_to_timespec(sk->sk_stamp);
+        }
+        err = 0;
+        if (put_user(ts.tv_sec, &ctv->tv_sec) ||
+                        put_user(ts.tv_nsec, &ctv->tv_nsec))
+                err = -EFAULT;
+        return err;
+}
+EXPORT_SYMBOL(compat_sock_get_timestampns);
+
 asmlinkage long compat_sys_getsockopt(int fd, int level, int optname,
                                 char __user *optval, int __user *optlen)
 {