net: Add a new socket option for a future transmit time.

This patch introduces SO_TXTIME. User space enables this option in
order to pass a desired future transmit time in a CMSG when calling
sendmsg(2). The argument to this socket option is a 8-bytes long struct
provided by the uapi header net_tstamp.h defined as:

struct sock_txtime {
	clockid_t 	clockid;
	u32		flags;
};

Note that new fields were added to struct sock by filling a 2-bytes
hole found in the struct. For that reason, neither the struct size or
number of cachelines were altered.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Richard Cochran
2018-07-03 15:42:48 -07:00
committed by David S. Miller
parent c47d8c2f38
commit 80b14dee2b
11 changed files with 84 additions and 0 deletions

View File

@@ -101,6 +101,9 @@
#define SO_ZEROCOPY 0x003e
#define SO_TXTIME 0x003f
#define SCM_TXTIME SO_TXTIME
/* Security levels - as per NRL IPv6 - don't actually do anything */
#define SO_SECURITY_AUTHENTICATION 0x5001
#define SO_SECURITY_ENCRYPTION_TRANSPORT 0x5002