From b7aa0bf70c4afb9e38be25f5c0922498d0f8684c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 19 Apr 2007 16:16:32 -0700 Subject: [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 CC: Stephen Hemminger CC: John find Signed-off-by: David S. Miller --- net/packet/af_packet.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'net/packet/af_packet.c') diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 28d47e8f2873..f9866a8456a1 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -582,6 +582,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe unsigned long status = TP_STATUS_LOSING|TP_STATUS_USER; unsigned short macoff, netoff; struct sk_buff *copy_skb = NULL; + struct timeval tv; if (skb->pkt_type == PACKET_LOOPBACK) goto drop; @@ -656,12 +657,13 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe h->tp_snaplen = snaplen; h->tp_mac = macoff; h->tp_net = netoff; - if (skb->tstamp.off_sec == 0) { + if (skb->tstamp.tv64 == 0) { __net_timestamp(skb); sock_enable_timestamp(sk); } - h->tp_sec = skb->tstamp.off_sec; - h->tp_usec = skb->tstamp.off_usec; + tv = ktime_to_timeval(skb->tstamp); + h->tp_sec = tv.tv_sec; + h->tp_usec = tv.tv_usec; sll = (struct sockaddr_ll*)((u8*)h + TPACKET_ALIGN(sizeof(*h))); sll->sll_halen = 0; -- cgit v1.2.3