From f24b9be5957b38bb420b838115040dc2031b7d0c Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Mon, 4 Aug 2014 22:11:45 -0400 Subject: 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 Signed-off-by: David S. Miller --- include/uapi/linux/errqueue.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/uapi/linux/errqueue.h') 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 */ -- cgit v1.2.3 From e7fd2885385157d46c85f282fc6d7d297db43e1f Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Mon, 4 Aug 2014 22:11:48 -0400 Subject: net-timestamp: SCHED timestamp on entering packet scheduler Kernel transmit latency is often incurred in the packet scheduler. Introduce a new timestamp on transmission just before entering the scheduler. When data travels through multiple devices (bonding, tunneling, ...) each device will export an individual timestamp. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- include/uapi/linux/errqueue.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux/errqueue.h') diff --git a/include/uapi/linux/errqueue.h b/include/uapi/linux/errqueue.h index accee72cae7c..17437cf297b7 100644 --- a/include/uapi/linux/errqueue.h +++ b/include/uapi/linux/errqueue.h @@ -39,6 +39,7 @@ struct scm_timestamping { */ enum { SCM_TSTAMP_SND, /* driver passed skb to NIC, or HW */ + SCM_TSTAMP_SCHED, /* data entered the packet scheduler */ }; #endif /* _UAPI_LINUX_ERRQUEUE_H */ -- cgit v1.2.3 From e1c8a607b28190cd09a271508aa3025d3c2f312e Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Mon, 4 Aug 2014 22:11:50 -0400 Subject: net-timestamp: ACK timestamp for bytestreams Add SOF_TIMESTAMPING_TX_ACK, a request for a tstamp when the last byte in the send() call is acknowledged. It implements the feature for TCP. The timestamp is generated when the TCP socket cumulative ACK is moved beyond the tracked seqno for the first time. The feature ignores SACK and FACK, because those acknowledge the specific byte, but not necessarily the entire contents of the buffer up to that byte. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- include/uapi/linux/errqueue.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux/errqueue.h') diff --git a/include/uapi/linux/errqueue.h b/include/uapi/linux/errqueue.h index 17437cf297b7..07bdce1f444a 100644 --- a/include/uapi/linux/errqueue.h +++ b/include/uapi/linux/errqueue.h @@ -40,6 +40,7 @@ struct scm_timestamping { enum { SCM_TSTAMP_SND, /* driver passed skb to NIC, or HW */ SCM_TSTAMP_SCHED, /* data entered the packet scheduler */ + SCM_TSTAMP_ACK, /* data acknowledged by peer */ }; #endif /* _UAPI_LINUX_ERRQUEUE_H */ -- cgit v1.2.3