tcp: add RTAX_FEATURE_TCP_USEC_TS

This new dst feature flag will be used to allow TCP to use usec
based timestamps instead of msec ones.

ip route .... feature tcp_usec_ts

Also document that RTAX_FEATURE_SACK and RTAX_FEATURE_TIMESTAMP
are unused.

RTAX_FEATURE_ALLFRAG is also going away soon.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index e15452df9804f6d5badddaed3445c5586b1fcea3..04a0e647ef747e5c83520cd1b1c2156d3a315ba5 100644 (file)
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -576,4 +576,9 @@ void tcp_sock_set_quickack(struct sock *sk, int val);
 int tcp_sock_set_syncnt(struct sock *sk, int val);
 int tcp_sock_set_user_timeout(struct sock *sk, int val);
 
+static inline bool dst_tcp_usec_ts(const struct dst_entry *dst)
+{
+       return dst_feature(dst, RTAX_FEATURE_TCP_USEC_TS);
+}
+
 #endif /* _LINUX_TCP_H */

diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 51c13cf9c5aee4a2d1ab33c1a89043383d67b9cf..aa2482a0614aa685590fcc73819cbe1baac63d66 100644 (file)
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -502,13 +502,17 @@ enum {
 
 #define RTAX_MAX (__RTAX_MAX - 1)
 
-#define RTAX_FEATURE_ECN       (1 << 0)
-#define RTAX_FEATURE_SACK      (1 << 1)
-#define RTAX_FEATURE_TIMESTAMP (1 << 2)
-#define RTAX_FEATURE_ALLFRAG   (1 << 3)
-
-#define RTAX_FEATURE_MASK      (RTAX_FEATURE_ECN | RTAX_FEATURE_SACK | \
-                                RTAX_FEATURE_TIMESTAMP | RTAX_FEATURE_ALLFRAG)
+#define RTAX_FEATURE_ECN               (1 << 0)
+#define RTAX_FEATURE_SACK              (1 << 1) /* unused */
+#define RTAX_FEATURE_TIMESTAMP         (1 << 2) /* unused */
+#define RTAX_FEATURE_ALLFRAG           (1 << 3)
+#define RTAX_FEATURE_TCP_USEC_TS       (1 << 4)
+
+#define RTAX_FEATURE_MASK      (RTAX_FEATURE_ECN |             \
+                                RTAX_FEATURE_SACK |            \
+                                RTAX_FEATURE_TIMESTAMP |       \
+                                RTAX_FEATURE_ALLFRAG |         \
+                                RTAX_FEATURE_TCP_USEC_TS)
 
 struct rta_session {
        __u8    proto;