[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>

4 files changed, 11 insertions, 9 deletions

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index fb39604c3d09..a963a31e5fb6 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -255,7 +255,7 @@ static int ipv6_dest_hao(struct sk_buff **skbp, int optoff)
         ipv6_addr_copy(&ipv6h->saddr, &hao->addr);
         ipv6_addr_copy(&hao->addr, &tmp_addr);
 
-        if (skb->tstamp.off_sec == 0)
+        if (skb->tstamp.tv64 == 0)
                 __net_timestamp(skb);
 
         return 1;
diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c
index fdb30a5916e5..66a2c4135251 100644
--- a/net/ipv6/netfilter/ip6_queue.c
+++ b/net/ipv6/netfilter/ip6_queue.c
@@ -195,6 +195,7 @@ ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
         struct sk_buff *skb;
         struct ipq_packet_msg *pmsg;
         struct nlmsghdr *nlh;
+        struct timeval tv;
 
         read_lock_bh(&queue_lock);
 
@@ -239,8 +240,9 @@ ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 
         pmsg->packet_id       = (unsigned long )entry;
         pmsg->data_len        = data_len;
-        pmsg->timestamp_sec   = entry->skb->tstamp.off_sec;
-        pmsg->timestamp_usec  = entry->skb->tstamp.off_usec;
+        tv = ktime_to_timeval(entry->skb->tstamp);
+        pmsg->timestamp_sec   = tv.tv_sec;
+        pmsg->timestamp_usec  = tv.tv_usec;
         pmsg->mark            = entry->skb->mark;
         pmsg->hook            = entry->info->hook;
         pmsg->hw_protocol     = entry->skb->protocol;
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 15ab1e3e8b56..c311b9a12ca6 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -82,7 +82,7 @@ struct nf_ct_frag6_queue
         struct sk_buff          *fragments;
         int                     len;
         int                     meat;
-        struct timeval          stamp;
+        ktime_t                 stamp;
         unsigned int            csum;
         __u8                    last_in;        /* has first/last segment arrived? */
 #define COMPLETE                4
@@ -542,7 +542,7 @@ static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb,
                 fq->fragments = skb;
 
         skb->dev = NULL;
-        skb_get_timestamp(skb, &fq->stamp);
+        fq->stamp = skb->tstamp;
         fq->meat += skb->len;
         atomic_add(skb->truesize, &nf_ct_frag6_mem);
 
@@ -648,7 +648,7 @@ nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
 
         head->next = NULL;
         head->dev = dev;
-        skb_set_timestamp(head, &fq->stamp);
+        head->tstamp = fq->stamp;
         head->nh.ipv6h->payload_len = htons(payload_len);
 
         /* Yes, and fold redundant checksum back. 8) */
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 7034c54e5010..1dde449379fb 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -88,7 +88,7 @@ struct frag_queue
         int                     len;
         int                     meat;
         int                     iif;
-        struct timeval          stamp;
+        ktime_t                 stamp;
         unsigned int            csum;
         __u8                    last_in;        /* has first/last segment arrived? */
 #define COMPLETE                4
@@ -562,7 +562,7 @@ static void ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
         if (skb->dev)
                 fq->iif = skb->dev->ifindex;
         skb->dev = NULL;
-        skb_get_timestamp(skb, &fq->stamp);
+        fq->stamp = skb->tstamp;
         fq->meat += skb->len;
         atomic_add(skb->truesize, &ip6_frag_mem);
 
@@ -663,7 +663,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff **skb_in,
 
         head->next = NULL;
         head->dev = dev;
-        skb_set_timestamp(head, &fq->stamp);
+        head->tstamp = fq->stamp;
         head->nh.ipv6h->payload_len = htons(payload_len);
         IP6CB(head)->nhoff = nhoff;