Provided by: systemtap-doc_2.3-1ubuntu1.4_all 

NAME
probe::socket.sendmsg - Message is currently being sent on a socket.
SYNOPSIS
socket.sendmsg
VALUES
state
Socket state value
size
Message size in bytes
name
Name of this probe
type
Socket type value
protocol
Protocol value
family
Protocol family value
flags
Socket flags value
CONTEXT
The message sender
DESCRIPTION
Fires at the beginning of sending a message on a socket via the sock_sendmsg function
SystemTap Tapset Reference March 2016 PROBE::SOCKET.SEND(3stap)