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/linux/skbuff.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 281deced7469..477f0f60db45 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -249,6 +249,9 @@ enum { SKBTX_SHARED_FRAG = 1 << 5, }; +#define SKBTX_ANY_SW_TSTAMP SKBTX_SW_TSTAMP +#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP) + /* * The callback notifies userspace to release buffers when skb DMA is done in * lower device, the skb last reference should be 0 when calling this. -- cgit v1.2.3 From 09c2d251b70723650ba47e83571ff49281320f7c Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Mon, 4 Aug 2014 22:11:47 -0400 Subject: net-timestamp: add key to disambiguate concurrent datagrams Datagrams timestamped on transmission can coexist in the kernel stack and be reordered in packet scheduling. When reading looped datagrams from the socket error queue it is not always possible to unique correlate looped data with original send() call (for application level retransmits). Even if possible, it may be expensive and complex, requiring packet inspection. Introduce a data-independent ID mechanism to associate timestamps with send calls. Pass an ID alongside the timestamp in field ee_data of sock_extended_err. The ID is a simple 32 bit unsigned int that is associated with the socket and incremented on each send() call for which software tx timestamp generation is enabled. The feature is enabled only if SOF_TIMESTAMPING_OPT_ID is set, to avoid changing ee_data for existing applications that expect it 0. The counter is reset each time the flag is reenabled. Reenabling does not change the ID of already submitted data. It is possible to receive out of order IDs if the timestamp stream is not quiesced first. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- include/linux/skbuff.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 477f0f60db45..0e35b3af7317 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -278,6 +278,7 @@ struct skb_shared_info { unsigned short gso_type; struct sk_buff *frag_list; struct skb_shared_hwtstamps hwtstamps; + u32 tskey; __be32 ip6_frag_id; /* -- 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/linux/skbuff.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 0e35b3af7317..50e1e9b3a5a5 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -229,7 +229,7 @@ enum { /* generate hardware time stamp */ SKBTX_HW_TSTAMP = 1 << 0, - /* generate software time stamp */ + /* generate software time stamp when queueing packet to NIC */ SKBTX_SW_TSTAMP = 1 << 1, /* device driver is going to provide hardware time stamp */ @@ -247,9 +247,12 @@ enum { * all frags to avoid possible bad checksum */ SKBTX_SHARED_FRAG = 1 << 5, + + /* generate software time stamp when entering packet scheduling */ + SKBTX_SCHED_TSTAMP = 1 << 6, }; -#define SKBTX_ANY_SW_TSTAMP SKBTX_SW_TSTAMP +#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | SKBTX_SCHED_TSTAMP) #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP) /* @@ -2695,6 +2698,10 @@ static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) void skb_complete_tx_timestamp(struct sk_buff *skb, struct skb_shared_hwtstamps *hwtstamps); +void __skb_tstamp_tx(struct sk_buff *orig_skb, + struct skb_shared_hwtstamps *hwtstamps, + struct sock *sk, int tstype); + /** * skb_tstamp_tx - queue clone of skb with send time stamps * @orig_skb: the original outgoing packet -- 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/linux/skbuff.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 50e1e9b3a5a5..11c270551d25 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -250,9 +250,14 @@ enum { /* generate software time stamp when entering packet scheduling */ SKBTX_SCHED_TSTAMP = 1 << 6, + + /* generate software timestamp on peer data acknowledgment */ + SKBTX_ACK_TSTAMP = 1 << 7, }; -#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | SKBTX_SCHED_TSTAMP) +#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ + SKBTX_SCHED_TSTAMP | \ + SKBTX_ACK_TSTAMP) #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP) /* -- cgit v1.2.3