[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>

17 files changed, 70 insertions, 68 deletions

diff --git a/net/bridge/netfilter/ebt_ulog.c b/net/bridge/netfilter/ebt_ulog.c
index 8e15cc47f6c0..259f5c370f3c 100644
--- a/net/bridge/netfilter/ebt_ulog.c
+++ b/net/bridge/netfilter/ebt_ulog.c
@@ -130,6 +130,7 @@ static void ebt_ulog_packet(unsigned int hooknr, const struct sk_buff *skb,
         unsigned int group = uloginfo->nlgroup;
         ebt_ulog_buff_t *ub = &ulog_buffers[group];
         spinlock_t *lock = &ub->lock;
+        ktime_t kt;
 
         if ((uloginfo->cprange == 0) ||
             (uloginfo->cprange > skb->len + ETH_HLEN))
@@ -164,9 +165,10 @@ static void ebt_ulog_packet(unsigned int hooknr, const struct sk_buff *skb,
 
         /* Fill in the ulog data */
         pm->version = EBT_ULOG_VERSION;
-        do_gettimeofday(&pm->stamp);
+        kt = ktime_get_real();
+        pm->stamp = ktime_to_timeval(kt);
         if (ub->qlen == 1)
-                skb_set_timestamp(ub->skb, &pm->stamp);
+                ub->skb->tstamp = kt;
         pm->data_len = copy_len;
         pm->mark = skb->mark;
         pm->hook = hooknr;
diff --git a/net/compat.c b/net/compat.c
index 1f32866d09b7..17c2710b2b93 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -545,15 +545,20 @@ int compat_sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
         struct compat_timeval __user *ctv =
                         (struct compat_timeval __user*) userstamp;
         int err = -ENOENT;
+        struct timeval tv;
 
         if (!sock_flag(sk, SOCK_TIMESTAMP))
                 sock_enable_timestamp(sk);
-        if (sk->sk_stamp.tv_sec == -1)
+        tv = ktime_to_timeval(sk->sk_stamp);
+        if (tv.tv_sec == -1)
                 return err;
-        if (sk->sk_stamp.tv_sec == 0)
-                do_gettimeofday(&sk->sk_stamp);
-        if (put_user(sk->sk_stamp.tv_sec, &ctv->tv_sec) ||
-                        put_user(sk->sk_stamp.tv_usec, &ctv->tv_usec))
+        if (tv.tv_sec == 0) {
+                sk->sk_stamp = ktime_get_real();
+                tv = ktime_to_timeval(sk->sk_stamp);
+        }
+        err = 0;
+        if (put_user(tv.tv_sec, &ctv->tv_sec) ||
+                        put_user(tv.tv_usec, &ctv->tv_usec))
                 err = -EFAULT;
         return err;
 }
diff --git a/net/core/dev.c b/net/core/dev.c
index 4dc93cc4d5b7..582db646cc54 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1031,23 +1031,12 @@ void net_disable_timestamp(void)
         atomic_dec(&netstamp_needed);
 }
 
-void __net_timestamp(struct sk_buff *skb)
-{
-        struct timeval tv;
-
-        do_gettimeofday(&tv);
-        skb_set_timestamp(skb, &tv);
-}
-EXPORT_SYMBOL(__net_timestamp);
-
 static inline void net_timestamp(struct sk_buff *skb)
 {
         if (atomic_read(&netstamp_needed))
                 __net_timestamp(skb);
-        else {
-                skb->tstamp.off_sec = 0;
-                skb->tstamp.off_usec = 0;
-        }
+        else
+                skb->tstamp.tv64 = 0;
 }
 
 /*
@@ -1577,7 +1566,7 @@ int netif_rx(struct sk_buff *skb)
         if (netpoll_rx(skb))
                 return NET_RX_DROP;
 
-        if (!skb->tstamp.off_sec)
+        if (!skb->tstamp.tv64)
                 net_timestamp(skb);
 
         /*
@@ -1769,7 +1758,7 @@ int netif_receive_skb(struct sk_buff *skb)
         if (skb->dev->poll && netpoll_rx(skb))
                 return NET_RX_DROP;
 
-        if (!skb->tstamp.off_sec)
+        if (!skb->tstamp.tv64)
                 net_timestamp(skb);
 
         if (!skb->iif)
diff --git a/net/core/sock.c b/net/core/sock.c
index 6d35d5775ba8..6ddb3664b993 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1512,8 +1512,7 @@ void sock_init_data(struct socket *sock, struct sock *sk)
         sk->sk_rcvtimeo         =       MAX_SCHEDULE_TIMEOUT;
         sk->sk_sndtimeo         =       MAX_SCHEDULE_TIMEOUT;
 
-        sk->sk_stamp.tv_sec     = -1L;
-        sk->sk_stamp.tv_usec    = -1L;
+        sk->sk_stamp = ktime_set(-1L, -1L);
 
         atomic_set(&sk->sk_refcnt, 1);
 }
@@ -1554,14 +1553,17 @@ EXPORT_SYMBOL(release_sock);
 
 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
 {
+        struct timeval tv;
         if (!sock_flag(sk, SOCK_TIMESTAMP))
                 sock_enable_timestamp(sk);
-        if (sk->sk_stamp.tv_sec == -1)
+        tv = ktime_to_timeval(sk->sk_stamp);
+        if (tv.tv_sec == -1)
                 return -ENOENT;
-        if (sk->sk_stamp.tv_sec == 0)
-                do_gettimeofday(&sk->sk_stamp);
-        return copy_to_user(userstamp, &sk->sk_stamp, sizeof(struct timeval)) ?
-                -EFAULT : 0;
+        if (tv.tv_sec == 0) {
+                sk->sk_stamp = ktime_get_real();
+                tv = ktime_to_timeval(sk->sk_stamp);
+        }
+        return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
 }
 EXPORT_SYMBOL(sock_get_timestamp);
 
diff --git a/net/econet/af_econet.c b/net/econet/af_econet.c
index bc12e36263f0..f573eddc6034 100644
--- a/net/econet/af_econet.c
+++ b/net/econet/af_econet.c
@@ -162,7 +162,7 @@ static int econet_recvmsg(struct kiocb *iocb, struct socket *sock,
         err = memcpy_toiovec(msg->msg_iov, skb->data, copied);
         if (err)
                 goto out_free;
-        skb_get_timestamp(skb, &sk->sk_stamp);
+        sk->sk_stamp = skb->tstamp;
 
         if (msg->msg_name)
                 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index b6f055380373..e10be7d7752d 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -92,7 +92,7 @@ struct ipq {
         spinlock_t      lock;
         atomic_t        refcnt;
         struct timer_list timer;        /* when will this queue expire?         */
-        struct timeval  stamp;
+        ktime_t         stamp;
         int             iif;
         unsigned int    rid;
         struct inet_peer *peer;
@@ -592,7 +592,7 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
         if (skb->dev)
                 qp->iif = skb->dev->ifindex;
         skb->dev = NULL;
-        skb_get_timestamp(skb, &qp->stamp);
+        qp->stamp = skb->tstamp;
         qp->meat += skb->len;
         atomic_add(skb->truesize, &ip_frag_mem);
         if (offset == 0)
@@ -674,7 +674,7 @@ static struct sk_buff *ip_frag_reasm(struct ipq *qp, struct net_device *dev)
 
         head->next = NULL;
         head->dev = dev;
-        skb_set_timestamp(head, &qp->stamp);
+        head->tstamp = qp->stamp;
 
         iph = head->nh.iph;
         iph->frag_off = 0;
@@ -734,7 +734,7 @@ struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user)
         return NULL;
 }
 
-void ipfrag_init(void)
+void __init ipfrag_init(void)
 {
         ipfrag_hash_rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^
                                  (jiffies ^ (jiffies >> 6)));
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index a14798a850d7..5842f1aa973a 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -197,6 +197,7 @@ 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);
 
@@ -241,8 +242,9 @@ 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/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
index 9acc018766f2..9718b666a380 100644
--- a/net/ipv4/netfilter/ipt_ULOG.c
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -187,6 +187,7 @@ static void ipt_ulog_packet(unsigned int hooknum,
         ulog_packet_msg_t *pm;
         size_t size, copy_len;
         struct nlmsghdr *nlh;
+        struct timeval tv;
 
         /* ffs == find first bit set, necessary because userspace
          * is already shifting groupnumber, but we need unshifted.
@@ -232,13 +233,14 @@ static void ipt_ulog_packet(unsigned int hooknum,
         pm = NLMSG_DATA(nlh);
 
         /* We might not have a timestamp, get one */
-        if (skb->tstamp.off_sec == 0)
+        if (skb->tstamp.tv64 == 0)
                 __net_timestamp((struct sk_buff *)skb);
 
         /* copy hook, prefix, timestamp, payload, etc. */
         pm->data_len = copy_len;
-        put_unaligned(skb->tstamp.off_sec, &pm->timestamp_sec);
-        put_unaligned(skb->tstamp.off_usec, &pm->timestamp_usec);
+        tv = ktime_to_timeval(skb->tstamp);
+        put_unaligned(tv.tv_sec, &pm->timestamp_sec);
+        put_unaligned(tv.tv_usec, &pm->timestamp_usec);
         put_unaligned(skb->mark, &pm->mark);
         pm->hook = hooknum;
         if (prefix != NULL)
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;
 
diff --git a/net/ipx/af_ipx.c b/net/ipx/af_ipx.c
index cac35a77f069..6c6c0a3a0ab5 100644
--- a/net/ipx/af_ipx.c
+++ b/net/ipx/af_ipx.c
@@ -1807,8 +1807,8 @@ static int ipx_recvmsg(struct kiocb *iocb, struct socket *sock,
                                      copied);
         if (rc)
                 goto out_free;
-        if (skb->tstamp.off_sec)
-                skb_get_timestamp(skb, &sk->sk_stamp);
+        if (skb->tstamp.tv64)
+                sk->sk_stamp = skb->tstamp;
 
         msg->msg_namelen = sizeof(*sipx);
 
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);
         }
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index d9ce4a71d0f3..cfbee39f61d6 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -495,11 +495,11 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
                 NFA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw);
         }
 
-        if (entskb->tstamp.off_sec) {
+        if (entskb->tstamp.tv64) {
                 struct nfqnl_msg_packet_timestamp ts;
-
-                ts.sec = cpu_to_be64(entskb->tstamp.off_sec);
-                ts.usec = cpu_to_be64(entskb->tstamp.off_usec);
+                struct timeval tv = ktime_to_timeval(entskb->tstamp);
+                ts.sec = cpu_to_be64(tv.tv_sec);
+                ts.usec = cpu_to_be64(tv.tv_usec);
 
                 NFA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts);
         }
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;
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 2772fee93881..22f61aee4824 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -798,16 +798,12 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
                 dprintk("svc: recvfrom returned error %d\n", -err);
         }
         rqstp->rq_addrlen = sizeof(rqstp->rq_addr);
-        if (skb->tstamp.off_sec == 0) {
-                struct timeval tv;
-
-                tv.tv_sec = xtime.tv_sec;
-                tv.tv_usec = xtime.tv_nsec / NSEC_PER_USEC;
-                skb_set_timestamp(skb, &tv);
+        if (skb->tstamp.tv64 == 0) {
+                skb->tstamp = ktime_get_real();
                 /* Don't enable netstamp, sunrpc doesn't
                    need that much accuracy */
         }
-        skb_get_timestamp(skb, &svsk->sk_sk->sk_stamp);
+        svsk->sk_sk->sk_stamp = skb->tstamp;
         set_bit(SK_DATA, &svsk->sk_flags); /* there may be more data... */
 
         /*