Merge branch 'af_packet-timestamp'

Daniel Borkmann says:

====================
This is a joint effort with Willem to bring optional i) tx hw/sw
timestamping into PF_PACKET, that was reported by Paul Chavent,
and ii) to expose the type of timestamp to the user, which is in
the current situation not possible to distinguish with the RX_RING
and TX_RING API (but distinguishable through the normal timestamping
API), reported by Richard Cochran. This set is based on top of
``packet: account statistics only in tpacket_stats_u''. Related
discussion can be found in: http://patchwork.ozlabs.org/patch/238125/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 71 insertions, 28 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 898cf5c566f9..af9185d0be6a 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3327,12 +3327,8 @@ void skb_tstamp_tx(struct sk_buff *orig_skb,
         if (!sk)
                 return;
 
-        skb = skb_clone(orig_skb, GFP_ATOMIC);
-        if (!skb)
-                return;
-
         if (hwtstamps) {
-                *skb_hwtstamps(skb) =
+                *skb_hwtstamps(orig_skb) =
                         *hwtstamps;
         } else {
                 /*
@@ -3340,9 +3336,13 @@ void skb_tstamp_tx(struct sk_buff *orig_skb,
                  * so keep the shared tx_flags and only
                  * store software time stamp
                  */
-                skb->tstamp = ktime_get_real();
+                orig_skb->tstamp = ktime_get_real();
         }
 
+        skb = skb_clone(orig_skb, GFP_ATOMIC);
+        if (!skb)
+                return;
+
         serr = SKB_EXT_ERR(skb);
         memset(serr, 0, sizeof(*serr));
         serr->ee.ee_errno = ENOMSG;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 7e387ff64465..ba8309a3e01b 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -339,6 +339,59 @@ static int __packet_get_status(struct packet_sock *po, void *frame)
         }
 }
 
+static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
+                                   unsigned int flags)
+{
+        struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
+
+        if (shhwtstamps) {
+                if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) &&
+                    ktime_to_timespec_cond(shhwtstamps->syststamp, ts))
+                        return TP_STATUS_TS_SYS_HARDWARE;
+                if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
+                    ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
+                        return TP_STATUS_TS_RAW_HARDWARE;
+        }
+
+        if (ktime_to_timespec_cond(skb->tstamp, ts))
+                return TP_STATUS_TS_SOFTWARE;
+
+        return 0;
+}
+
+static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
+                                    struct sk_buff *skb)
+{
+        union tpacket_uhdr h;
+        struct timespec ts;
+        __u32 ts_status;
+
+        if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
+                return 0;
+
+        h.raw = frame;
+        switch (po->tp_version) {
+        case TPACKET_V1:
+                h.h1->tp_sec = ts.tv_sec;
+                h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
+                break;
+        case TPACKET_V2:
+                h.h2->tp_sec = ts.tv_sec;
+                h.h2->tp_nsec = ts.tv_nsec;
+                break;
+        case TPACKET_V3:
+        default:
+                WARN(1, "TPACKET version not supported.\n");
+                BUG();
+        }
+
+        /* one flush is safe, as both fields always lie on the same cacheline */
+        flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
+        smp_wmb();
+
+        return ts_status;
+}
+
 static void *packet_lookup_frame(struct packet_sock *po,
                 struct packet_ring_buffer *rb,
                 unsigned int position,
@@ -1657,26 +1710,6 @@ drop:
         return 0;
 }
 
-static void tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
-                                  unsigned int flags)
-{
-        struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
-
-        if (shhwtstamps) {
-                if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) &&
-                    ktime_to_timespec_cond(shhwtstamps->syststamp, ts))
-                        return;
-                if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
-                    ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
-                        return;
-        }
-
-        if (ktime_to_timespec_cond(skb->tstamp, ts))
-                return;
-
-        getnstimeofday(ts);
-}
-
 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
                        struct packet_type *pt, struct net_device *orig_dev)
 {
@@ -1691,6 +1724,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
         unsigned short macoff, netoff, hdrlen;
         struct sk_buff *copy_skb = NULL;
         struct timespec ts;
+        __u32 ts_status;
 
         if (skb->pkt_type == PACKET_LOOPBACK)
                 goto drop;
@@ -1773,7 +1807,11 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
         spin_unlock(&sk->sk_receive_queue.lock);
 
         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
-        tpacket_get_timestamp(skb, &ts, po->tp_tstamp);
+
+        if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
+                getnstimeofday(&ts);
+
+        status |= ts_status;
 
         switch (po->tp_version) {
         case TPACKET_V1:
@@ -1874,10 +1912,14 @@ static void tpacket_destruct_skb(struct sk_buff *skb)
         void *ph;
 
         if (likely(po->tx_ring.pg_vec)) {
+                __u32 ts;
+
                 ph = skb_shinfo(skb)->destructor_arg;
                 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
                 atomic_dec(&po->tx_ring.pending);
-                __packet_set_status(po, ph, TP_STATUS_AVAILABLE);
+
+                ts = __packet_set_timestamp(po, ph, skb);
+                __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
         }
 
         sock_wfree(skb);
@@ -1900,6 +1942,7 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
         skb->dev = dev;
         skb->priority = po->sk.sk_priority;
         skb->mark = po->sk.sk_mark;
+        sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
         skb_shinfo(skb)->destructor_arg = ph.raw;
 
         switch (po->tp_version) {