Let Tramp sudo sessions expire after a timeout

* doc/misc/tramp.texi (Inline methods) <sudo, doas>: Both methods expire
the underlying session per default.
(Predefined connection information): Explain "session-timeout".

* etc/NEWS: Mention Tramp session expiration.

* lisp/net/tramp-sh.el (tramp-methods) <sudo, doas>:
Add `tramp-session-timeout'.
(tramp-timeout-session): New defun.
(tramp-maybe-open-connection): Handle session timeout.

* lisp/net/tramp.el (tramp-methods): Adapt docstring.
(tramp-equal-remote): Extend.

1 files changed, 5 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 4ed312c7216..13d660812d6 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -832,6 +832,11 @@ Tramp for some look-alike remote file names.
 *** For some connection methods, like "su" or "sudo", the host name in
 ad-hoc multi-hop file names must match the previous hop.
 
++++
+*** For the connection methods "sudo" and "doas" there exists a
+timeout, after which the underlying session is disabled.  This is for
+security reasons.
+
 ** Rcirc
 
 ---