- djm@cvs.openbsd.org 2014/07/03 06:39:19

     [ssh.c ssh_config.5]
     Add a %C escape sequence for LocalCommand and ControlPath that expands
     to a unique identifer based on a has of the tuple of (local host,
     remote user, hostname, port).

     Helps avoid exceeding sockaddr_un's miserly pathname limits for mux
     control paths.

     bz#2220, based on patch from mancha1 AT zoho.com; ok markus@

1 files changed, 9 insertions, 5 deletions

diff --git a/ssh_config.5 b/ssh_config.5
index 5c6bd29e..756762e4 100644
--- a/ssh_config.5
+++ b/ssh_config.5
@@ -33,7 +33,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $OpenBSD: ssh_config.5,v 1.187 2014/07/03 05:32:36 djm Exp $
+.\" $OpenBSD: ssh_config.5,v 1.188 2014/07/03 06:39:19 djm Exp $
 .Dd $Mdocdate: July 3 2014 $
 .Dt SSH_CONFIG 5
 .Os
@@ -499,14 +499,16 @@ specified on the command line,
 .Ql %p
 the destination port,
 .Ql %r
-by the remote login username, and
+by the remote login username,
 .Ql %u
 by the username of the user running
-.Xr ssh 1 .
+.Xr ssh 1 , and
+.Ql %C
+by a hash of the concatenation: %l%h%p%r.
 It is recommended that any
 .Cm ControlPath
 used for opportunistic connection sharing include
-at least %h, %p, and %r.
+at least %h, %p, and %r (or alternatively %C).
 This ensures that shared connections are uniquely identified.
 .It Cm ControlPersist
 When used in conjunction with
@@ -939,7 +941,9 @@ The following escape character substitutions will be performed:
 .Ql %r
 (remote user name) or
 .Ql %u
-(local user name).
+(local user name) or
+.Ql %C
+by a hash of the concatenation: %l%h%p%r.
 .Pp
 The command is run synchronously and does not have access to the
 session of the