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authorWillem de Bruijn <willemb@google.com>2014-08-05 06:11:50 +0400
committerDavid S. Miller <davem@davemloft.net>2014-08-06 03:35:54 +0400
commite1c8a607b28190cd09a271508aa3025d3c2f312e (patch)
tree83f4b5e777a13535434be99bee2e764a6677e647
parent4ed2d765dfaccff5ebdac68e2064b59125033a3b (diff)
downloadlinux-e1c8a607b28190cd09a271508aa3025d3c2f312e.tar.xz
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 <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/skbuff.h7
-rw-r--r--include/uapi/linux/errqueue.h1
-rw-r--r--include/uapi/linux/net_tstamp.h3
-rw-r--r--net/ipv4/tcp_input.c6
-rw-r--r--net/socket.c2
5 files changed, 17 insertions, 2 deletions
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)
/*
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 */
diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h
index 60733845fcdd..ff354021bb69 100644
--- a/include/uapi/linux/net_tstamp.h
+++ b/include/uapi/linux/net_tstamp.h
@@ -22,8 +22,9 @@ enum {
SOF_TIMESTAMPING_RAW_HARDWARE = (1<<6),
SOF_TIMESTAMPING_OPT_ID = (1<<7),
SOF_TIMESTAMPING_TX_SCHED = (1<<8),
+ SOF_TIMESTAMPING_TX_ACK = (1<<9),
- SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_TX_SCHED,
+ SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_TX_ACK,
SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) |
SOF_TIMESTAMPING_LAST
};
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 6a2984507755..a3d47af01906 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -74,6 +74,7 @@
#include <linux/ipsec.h>
#include <asm/unaligned.h>
#include <net/netdma.h>
+#include <linux/errqueue.h>
int sysctl_tcp_timestamps __read_mostly = 1;
int sysctl_tcp_window_scaling __read_mostly = 1;
@@ -3106,6 +3107,11 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
tp->retrans_stamp = 0;
}
+ if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_ACK_TSTAMP) &&
+ between(skb_shinfo(skb)->tskey, prior_snd_una,
+ tp->snd_una + 1))
+ __skb_tstamp_tx(skb, NULL, sk, SCM_TSTAMP_ACK);
+
if (!fully_acked)
break;
diff --git a/net/socket.c b/net/socket.c
index 3a2778d71631..ae89569a2db5 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -619,6 +619,8 @@ void sock_tx_timestamp(struct sock *sk, __u8 *tx_flags)
*tx_flags |= SKBTX_SW_TSTAMP;
if (sk->sk_tsflags & SOF_TIMESTAMPING_TX_SCHED)
*tx_flags |= SKBTX_SCHED_TSTAMP;
+ if (sk->sk_tsflags & SOF_TIMESTAMPING_TX_ACK)
+ *tx_flags |= SKBTX_ACK_TSTAMP;
if (sock_flag(sk, SOCK_WIFI_STATUS))
*tx_flags |= SKBTX_WIFI_STATUS;