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authorWillem de Bruijn <willemb@google.com>2014-08-04 22:11:45 -0400
committerDavid S. Miller <davem@davemloft.net>2014-08-05 16:35:53 -0700
commitf24b9be5957b38bb420b838115040dc2031b7d0c (patch)
tree9fdb50bbe86f08ff9c012137fa854d45e156b8f9 /include/uapi
parenta2b81b35f9e5ade210e4df2001f7a30ac390114d (diff)
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net-timestamp: extend SCM_TIMESTAMPING ancillary data struct
Applications that request kernel tx timestamps with SO_TIMESTAMPING read timestamps as recvmsg() ancillary data. The response is defined implicitly as timespec[3]. 1) define struct scm_timestamping explicitly and 2) add support for new tstamp types. On tx, scm_timestamping always accompanies a sock_extended_err. Define previously unused field ee_info to signal the type of ts[0]. Introduce SCM_TSTAMP_SND to define the existing behavior. The reception path is not modified. On rx, no struct similar to sock_extended_err is passed along with SCM_TIMESTAMPING. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/uapi')
-rw-r--r--include/uapi/linux/errqueue.h18
1 files changed, 18 insertions, 0 deletions
diff --git a/include/uapi/linux/errqueue.h b/include/uapi/linux/errqueue.h
index aacd4fb7102a..accee72cae7c 100644
--- a/include/uapi/linux/errqueue.h
+++ b/include/uapi/linux/errqueue.h
@@ -22,5 +22,23 @@ struct sock_extended_err {
#define SO_EE_OFFENDER(ee) ((struct sockaddr*)((ee)+1))
+/**
+ * struct scm_timestamping - timestamps exposed through cmsg
+ *
+ * The timestamping interfaces SO_TIMESTAMPING, MSG_TSTAMP_*
+ * communicate network timestamps by passing this struct in a cmsg with
+ * recvmsg(). See Documentation/networking/timestamping.txt for details.
+ */
+struct scm_timestamping {
+ struct timespec ts[3];
+};
+
+/* The type of scm_timestamping, passed in sock_extended_err ee_info.
+ * This defines the type of ts[0]. For SCM_TSTAMP_SND only, if ts[0]
+ * is zero, then this is a hardware timestamp and recorded in ts[2].
+ */
+enum {
+ SCM_TSTAMP_SND, /* driver passed skb to NIC, or HW */
+};
#endif /* _UAPI_LINUX_ERRQUEUE_H */