To export useful TCP statistics along with timestamps, such as
rwnd-limited time and min RTT, we enqueue a TLV list in error queue
immediately when a timestamp is generated.
Specifically, if user space requests SOF_TIMESTAMPING_TX_* timestamps
and sets SOF_TIMESTAMPING_OPT_STATS, the kernel will create a list of
TLVs (struct nlattr) containing all the statistics and store the list
in payload of the skb that is going to be enqueued into error queue.
Notice that SOF_TIMESTAMPING_OPT_STATS can only be set together with
SOF_TIMESTAMPING_OPT_TSONLY.
In addition, if the application in user space also enables receiving
timestamp (e.g. by SOF_TIMESTAMPING_SOFTWARE), calling recvfrom() on
error queue will return one more control message with a cmsg_type of
SCM_OPT_STATS containing the list of TLVs in its cmsg_data.
Signed-off-by: Francis Y. Yan <francisy...@gmail.com>
Signed-off-by: Yuchung Cheng <ych...@google.com>
---
arch/alpha/include/uapi/asm/socket.h | 2 ++
arch/avr32/include/uapi/asm/socket.h | 2 ++
arch/frv/include/uapi/asm/socket.h | 2 ++
arch/ia64/include/uapi/asm/socket.h | 2 ++
arch/m32r/include/uapi/asm/socket.h | 2 ++
arch/mips/include/uapi/asm/socket.h | 2 ++
arch/mn10300/include/uapi/asm/socket.h | 2 ++
arch/parisc/include/uapi/asm/socket.h | 2 ++
arch/powerpc/include/uapi/asm/socket.h | 2 ++
arch/s390/include/uapi/asm/socket.h | 2 ++
arch/sparc/include/uapi/asm/socket.h | 2 ++
arch/xtensa/include/uapi/asm/socket.h | 2 ++
include/linux/tcp.h | 3 +++
include/uapi/asm-generic/socket.h | 2 ++
include/uapi/linux/net_tstamp.h | 3 ++-
include/uapi/linux/tcp.h | 7 +++++++
net/core/skbuff.c | 10 ++++++++--
net/core/sock.c | 7 +++++++
net/ipv4/tcp.c | 23 +++++++++++++++++++++++
net/socket.c | 7 ++++++-
20 files changed, 82 insertions(+), 4 deletions(-)
diff --git a/arch/alpha/include/uapi/asm/socket.h
b/arch/alpha/include/uapi/asm/socket.h
index 9e46d6e..c9f30508b 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -97,4 +97,6 @@
#define SO_CNX_ADVICE 53
+#define SCM_OPT_STATS 54
+
#endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/avr32/include/uapi/asm/socket.h
b/arch/avr32/include/uapi/asm/socket.h
index 1fd147f..e937d3f 100644
--- a/arch/avr32/include/uapi/asm/socket.h
+++ b/arch/avr32/include/uapi/asm/socket.h
@@ -90,4 +90,6 @@
#define SO_CNX_ADVICE 53
+#define SCM_OPT_STATS 54
+
#endif /* _UAPI__ASM_AVR32_SOCKET_H */
diff --git a/arch/frv/include/uapi/asm/socket.h
b/arch/frv/include/uapi/asm/socket.h
index afbc98f0..f17c124 100644
--- a/arch/frv/include/uapi/asm/socket.h
+++ b/arch/frv/include/uapi/asm/socket.h
@@ -90,5 +90,7 @@
#define SO_CNX_ADVICE 53
+#define SCM_OPT_STATS 54
+
#endif /* _ASM_SOCKET_H */
diff --git a/arch/ia64/include/uapi/asm/socket.h
b/arch/ia64/include/uapi/asm/socket.h
index 0018fad..bdd72e2 100644
--- a/arch/ia64/include/uapi/asm/socket.h
+++ b/arch/ia64/include/uapi/asm/socket.h
@@ -99,4 +99,6 @@
#define SO_CNX_ADVICE 53
+#define SCM_OPT_STATS 54
+
#endif /* _ASM_IA64_SOCKET_H */
diff --git a/arch/m32r/include/uapi/asm/socket.h
b/arch/m32r/include/uapi/asm/socket.h
index 5fe42fc..217e311 100644
--- a/arch/m32r/include/uapi/asm/socket.h
+++ b/arch/m32r/include/uapi/asm/socket.h
@@ -90,4 +90,6 @@
#define SO_CNX_ADVICE 53
+#define SCM_OPT_STATS 54
+
#endif /* _ASM_M32R_SOCKET_H */
diff --git a/arch/mips/include/uapi/asm/socket.h
b/arch/mips/include/uapi/asm/socket.h
index 2027240a..76ea723 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -108,4 +108,6 @@
#define SO_CNX_ADVICE 53
+#define SCM_OPT_STATS 54
+
#endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/mn10300/include/uapi/asm/socket.h
b/arch/mn10300/include/uapi/asm/socket.h
index 5129f23..a4c0295 100644
--- a/arch/mn10300/include/uapi/asm/socket.h
+++ b/arch/mn10300/include/uapi/asm/socket.h
@@ -90,4 +90,6 @@
#define SO_CNX_ADVICE 53
+#define SCM_OPT_STATS 54
+
#endif /* _ASM_SOCKET_H */
diff --git a/arch/parisc/include/uapi/asm/socket.h
b/arch/parisc/include/uapi/asm/socket.h
index 9c935d7..05ef7c0 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -89,4 +89,6 @@
#define SO_CNX_ADVICE 0x402E
+#define SCM_OPT_STATS 0x402F
+
#endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/powerpc/include/uapi/asm/socket.h
b/arch/powerpc/include/uapi/asm/socket.h
index 1672e33..fe2dea1 100644
--- a/arch/powerpc/include/uapi/asm/socket.h
+++ b/arch/powerpc/include/uapi/asm/socket.h
@@ -97,4 +97,6 @@
#define SO_CNX_ADVICE 53
+#define SCM_OPT_STATS 54
+
#endif /* _ASM_POWERPC_SOCKET_H */
diff --git a/arch/s390/include/uapi/asm/socket.h
b/arch/s390/include/uapi/asm/socket.h
index 41b51c2..1bd8c67 100644
--- a/arch/s390/include/uapi/asm/socket.h
+++ b/arch/s390/include/uapi/asm/socket.h
@@ -96,4 +96,6 @@
#define SO_CNX_ADVICE 53
+#define SCM_OPT_STATS 54
+
#endif /* _ASM_SOCKET_H */
diff --git a/arch/sparc/include/uapi/asm/socket.h
b/arch/sparc/include/uapi/asm/socket.h
index 31aede3..e1b2237 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -86,6 +86,8 @@
#define SO_CNX_ADVICE 0x0037
+#define SCM_OPT_STATS 0x0038
+
/* Security levels - as per NRL IPv6 - don't actually do anything */
#define SO_SECURITY_AUTHENTICATION 0x5001
#define SO_SECURITY_ENCRYPTION_TRANSPORT 0x5002
diff --git a/arch/xtensa/include/uapi/asm/socket.h
b/arch/xtensa/include/uapi/asm/socket.h
index 81435d9..8aba6bd 100644
--- a/arch/xtensa/include/uapi/asm/socket.h
+++ b/arch/xtensa/include/uapi/asm/socket.h
@@ -101,4 +101,6 @@
#define SO_CNX_ADVICE 53
+#define SCM_OPT_STATS 54
+
#endif /* _XTENSA_SOCKET_H */
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index f5b588e..187af3a 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -427,4 +427,7 @@ static inline void tcp_saved_syn_free(struct tcp_sock *tp)
u32 tcp_rwnd_limited_delta(const struct tcp_sock *tp);
+#define OPT_STATS_DEFAULT_SIZE 256
+void tcp_put_opt_stats(struct sock *sk, struct sk_buff *skb);
+
#endif /* _LINUX_TCP_H */
diff --git a/include/uapi/asm-generic/socket.h
b/include/uapi/asm-generic/socket.h
index 67d632f..5a4735f 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -92,4 +92,6 @@
#define SO_CNX_ADVICE 53
+#define SCM_OPT_STATS 54
+
#endif /* __ASM_GENERIC_SOCKET_H */
diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h
index 264e515..464dcca 100644
--- a/include/uapi/linux/net_tstamp.h
+++ b/include/uapi/linux/net_tstamp.h
@@ -25,8 +25,9 @@ enum {
SOF_TIMESTAMPING_TX_ACK = (1<<9),
SOF_TIMESTAMPING_OPT_CMSG = (1<<10),
SOF_TIMESTAMPING_OPT_TSONLY = (1<<11),
+ SOF_TIMESTAMPING_OPT_STATS = (1<<12),
- SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_TSONLY,
+ SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_STATS,
SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) |
SOF_TIMESTAMPING_LAST
};
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index f1e2de4..9bee101 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -214,6 +214,13 @@ struct tcp_info {
__u64 tcpi_rwnd_limited; /* total time (us) limited by rwnd */
};
+/* netlink attributes type for SCM_OPT_STATS */
+enum {
+ TCP_NLA_UNSPEC,
+ TCP_NLA_RWND_LIMITED, /* total time (us) limited by rwnd */
+ TCP_NLA_MIN_RTT, /* min RTT in us */
+};
+
/* for TCP_MD5SIG socket option */
#define TCP_MD5SIG_MAXKEYLEN 80
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 3864b4b6..f924b76 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3805,7 +3805,7 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb,
struct sock *sk, int tstype)
{
struct sk_buff *skb;
- bool tsonly;
+ bool tsonly, opt_stats;
if (!sk)
return;
@@ -3814,7 +3814,10 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb,
if (!skb_may_tx_timestamp(sk, tsonly))
return;
- if (tsonly)
+ opt_stats = sk->sk_tsflags & SOF_TIMESTAMPING_OPT_STATS;
+ if (opt_stats)
+ skb = alloc_skb(OPT_STATS_DEFAULT_SIZE, GFP_ATOMIC);
+ else if (tsonly)
skb = alloc_skb(0, GFP_ATOMIC);
else
skb = skb_clone(orig_skb, GFP_ATOMIC);
@@ -3824,6 +3827,9 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb,
if (tsonly) {
skb_shinfo(skb)->tx_flags = skb_shinfo(orig_skb)->tx_flags;
skb_shinfo(skb)->tskey = skb_shinfo(orig_skb)->tskey;
+
+ if (opt_stats)
+ tcp_put_opt_stats(sk, skb);
}
if (hwtstamps)
diff --git a/net/core/sock.c b/net/core/sock.c
index 51a7304..d5650fa 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -853,6 +853,13 @@ set_rcvbuf:
sk->sk_tskey = 0;
}
}
+
+ if (val & SOF_TIMESTAMPING_OPT_STATS &&
+ !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
+ ret = -EINVAL;
+ break;
+ }
+
sk->sk_tsflags = val;
if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
sock_enable_timestamp(sk,
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index ed77f2c..d3ded20 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2787,6 +2787,29 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
}
EXPORT_SYMBOL_GPL(tcp_get_info);
+void tcp_put_opt_stats(struct sock *sk, struct sk_buff *skb)
+{
+ const struct tcp_sock *tp = tcp_sk(sk);
+ unsigned int start;
+ u64 rwnd_limited;
+
+ do {
+ start = read_seqcount_begin(&tp->seqcnt);
+ rwnd_limited = tp->rwnd_limited + tcp_rwnd_limited_delta(tp);
+ } while (read_seqcount_retry(&tp->seqcnt, start));
+
+ if (nla_put(skb, TCP_NLA_RWND_LIMITED, sizeof(u64), &rwnd_limited))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCP_NLA_MIN_RTT, tcp_min_rtt(tp)))
+ goto nla_put_failure;
+
+ return;
+
+nla_put_failure:
+ WARN_ONCE(1, "Not enough space for TCP stats\n");
+}
+
static int do_tcp_getsockopt(struct sock *sk, int level,
int optname, char __user *optval, int __user *optlen)
{
diff --git a/net/socket.c b/net/socket.c
index a1bd161..f1950d51 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -667,9 +667,14 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock
*sk,
(sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
ktime_to_timespec_cond(shhwtstamps->hwtstamp, tss.ts + 2))
empty = 0;
- if (!empty)
+ if (!empty) {
put_cmsg(msg, SOL_SOCKET,
SCM_TIMESTAMPING, sizeof(tss), &tss);
+
+ if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_STATS)
+ put_cmsg(msg, SOL_SOCKET, SCM_OPT_STATS,
+ skb->len, skb->data);
+ }
}
EXPORT_SYMBOL_GPL(__sock_recv_timestamp);
--
2.8.0.rc3.226.g39d4020
