net: TX timestamps for IPv6 UDP packets

Enabling TX timestamps (SO_TIMESTAMPING) for IPv6 UDP packets, in
the same fashion as for IPv4. Necessary in order for NICs such as
Intel 82580 to timestamp IPv6 packets.

Signed-off-by: Anders Berggren <anders@halon.se>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 0 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 25a2647f9942..065b3f7614fb 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1118,6 +1118,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
         int err;
         int offset = 0;
         int csummode = CHECKSUM_NONE;
+        __u8 tx_flags = 0;
 
         if (flags&MSG_PROBE)
                 return 0;
@@ -1202,6 +1203,13 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
                 }
         }
 
+        /* For UDP, check if TX timestamp is enabled */
+        if (sk->sk_type == SOCK_DGRAM) {
+                err = sock_tx_timestamp(sk, &tx_flags);
+                if (err)
+                        goto error;
+        }
+
         /*
          * Let's try using as much space as possible.
          * Use MTU if total length of the message fits into the MTU.
@@ -1306,6 +1314,12 @@ alloc_new_skb:
                                                            sk->sk_allocation);
                                 if (unlikely(skb == NULL))
                                         err = -ENOBUFS;
+                                else {
+                                        /* Only the initial fragment
+                                         * is time stamped.
+                                         */
+                                        tx_flags = 0;
+                                }
                         }
                         if (skb == NULL)
                                 goto error;
@@ -1317,6 +1331,9 @@ alloc_new_skb:
                         /* reserve for fragmentation */
                         skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
 
+                        if (sk->sk_type == SOCK_DGRAM)
+                                skb_shinfo(skb)->tx_flags = tx_flags;
+
                         /*
                          *      Find where to start putting bytes
                          */