[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, 18 insertions, 0 deletions

diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index 8b1c5d8bf4ef..c68b055fa26e 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -266,6 +266,23 @@ static int do_siocgstamp(unsigned int fd, unsigned int cmd, unsigned long arg)
         return err;
 }
 
+static int do_siocgstampns(unsigned int fd, unsigned int cmd, unsigned long arg)
+{
+        struct compat_timespec __user *up = compat_ptr(arg);
+        struct timespec kts;
+        mm_segment_t old_fs = get_fs();
+        int err;
+
+        set_fs(KERNEL_DS);
+        err = sys_ioctl(fd, cmd, (unsigned long)&kts);
+        set_fs(old_fs);
+        if (!err) {
+                err = put_user(kts.tv_sec, &up->tv_sec);
+                err |= __put_user(kts.tv_nsec, &up->tv_nsec);
+        }
+        return err;
+}
+
 struct ifmap32 {
         compat_ulong_t mem_start;
         compat_ulong_t mem_end;
@@ -2437,6 +2454,7 @@ HANDLE_IOCTL(SIOCBRDELIF, dev_ifsioc)
 /* Note SIOCRTMSG is no longer, so this is safe and * the user would have seen just an -EINVAL anyways. */
 HANDLE_IOCTL(SIOCRTMSG, ret_einval)
 HANDLE_IOCTL(SIOCGSTAMP, do_siocgstamp)
+HANDLE_IOCTL(SIOCGSTAMPNS, do_siocgstampns)
 #endif
 #ifdef CONFIG_BLOCK
 HANDLE_IOCTL(HDIO_GETGEO, hdio_getgeo)