[NET]: convert network timestamps to ktime_t

We currently use a special structure (struct skb_timeval) and plain
'struct timeval' to store packet timestamps in sk_buffs and struct
sock.

This has some drawbacks :
- Fixed resolution of micro second.
- Waste of space on 64bit platforms where sizeof(struct timeval)=16

I suggest using ktime_t that is a nice abstraction of high resolution
time services, currently capable of nanosecond resolution.

As sizeof(ktime_t) is 8 bytes, using ktime_t in 'struct sock' permits
a 8 byte shrink of this structure on 64bit architectures. Some other
structures also benefit from this size reduction (struct ipq in
ipv4/ip_fragment.c, struct frag_queue in ipv6/reassembly.c, ...)

Once this ktime infrastructure adopted, we can more easily provide
nanosecond resolution on top of it. (ioctl SIOCGSTAMPNS and/or
SO_TIMESTAMPNS/SCM_TIMESTAMPNS)

Note : this patch includes a bug correction in
compat_sock_get_timestamp() where a "err = 0;" was missing (so this
syscall returned -ENOENT instead of 0)

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

1 files changed, 4 insertions, 4 deletions

diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 5cb30ebba0f4..5eeebd2efa7a 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -509,11 +509,11 @@ __build_packet_message(struct nfulnl_instance *inst,
 		NFA_PUT(inst->skb, NFULA_HWADDR, sizeof(phw), &phw);
 	}
 
-	if (skb->tstamp.off_sec) {
+	if (skb->tstamp.tv64) {
 		struct nfulnl_msg_packet_timestamp ts;
-
-		ts.sec = cpu_to_be64(skb->tstamp.off_sec);
-		ts.usec = cpu_to_be64(skb->tstamp.off_usec);
+		struct timeval tv = ktime_to_timeval(skb->tstamp);
+		ts.sec = cpu_to_be64(tv.tv_sec);
+		ts.usec = cpu_to_be64(tv.tv_usec);
 
 		NFA_PUT(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts);
 	}