Compared to all the other work we're already doing to deliver
an skb to userspace this is very cheap - at worse an extra
call to ktime_get_real() - and very useful.
(and indeed it may even be cheaper if we're running from other hooks)
(background: Android occasionally logs packets which
caused wake from sleep/suspend and we'd like to have
timestamps reliably associated with these events)
Cc: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Cc: Martin KaFai Lau <kafai@xxxxxx>
Cc: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Maciej Żenczykowski <maze@xxxxxxxxxx>
---
net/netfilter/nfnetlink_log.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index e57eb168ee13..53c9e76473ba 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -470,7 +470,6 @@ __build_packet_message(struct nfnl_log_net *log,
sk_buff_data_t old_tail = inst->skb->tail;
struct sock *sk;
const unsigned char *hwhdrp;
- ktime_t tstamp;
nlh = nfnl_msg_put(inst->skb, 0, 0,
nfnl_msg_type(NFNL_SUBSYS_ULOG, NFULNL_MSG_PACKET),
@@ -599,10 +598,9 @@ __build_packet_message(struct nfnl_log_net *log,
goto nla_put_failure;
}
- tstamp = skb_tstamp_cond(skb, false);
- if (hooknum <= NF_INET_FORWARD && tstamp) {
+ if (hooknum <= NF_INET_FORWARD) {
+ struct timespec64 kts = ktime_to_timespec64(skb_tstamp_cond(skb, true));
struct nfulnl_msg_packet_timestamp ts;
- struct timespec64 kts = ktime_to_timespec64(tstamp);
ts.sec = cpu_to_be64(kts.tv_sec);
ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
--
2.41.0.487.g6d72f3e995-goog
