From: Michael Albinus Date: Wed, 21 Nov 2018 12:23:01 +0000 (+0100) Subject: Let Tramp sudo sessions expire after a timeout X-Git-Tag: emacs-27.0.90~4127 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=fb200f3e5775fa2811ba270c2a7b0295b42539a0;p=emacs.git Let Tramp sudo sessions expire after a timeout * doc/misc/tramp.texi (Inline methods) : 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) : 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. --- diff --git a/doc/misc/tramp.texi b/doc/misc/tramp.texi index 8cd0a72fc8c..79185285623 100644 --- a/doc/misc/tramp.texi +++ b/doc/misc/tramp.texi @@ -721,11 +721,17 @@ the host returned by the function @command{(system-name)}. See Similar to @option{su} method, @option{sudo} uses @command{sudo}. @command{sudo} must have sufficient rights to start a shell. +Due to security reasons, a @option{sudo} connection is disabled after +a predefined timeout (5 minutes per default). This can be changed, +see @ref{Predefined connection information}. + @item @option{doas} @cindex method @option{doas} @cindex @option{doas} method -This method is used on OpenBSD like the @command{sudo} command. +This method is used on OpenBSD like the @command{sudo} command. Like +the @option{sudo} method, a @option{sudo} connection is disabled after +a predefined timeout. @item @option{sg} @cindex method @option{sg} @@ -1826,6 +1832,24 @@ The parameters @code{tramp-remote-shell} and @code{tramp-remote-shell-login} in @code{tramp-methods} now have new values for the remote host. +A common use case is to override the session timeout of a connection, +that is the time (in seconds) after a connection is disabled, and must +be reestablished. This can be set for any connection; for the +@option{sudo} and @option{doas} methods there exist predefined values. +A value of @code{nil} disables this feature. For example: + +@lisp +@group +(add-to-list 'tramp-connection-properties + (list (regexp-quote "@trampfn{sudo,root@@system-name,}") + "session-timeout" 30)) +@end group +@end lisp + +@noindent +@samp{system-name} stands here for the host returned by the function +@command{(system-name)}. + @var{property} could also be any property found in @code{tramp-persistency-file-name}. 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 --- diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el index 4fb011b3423..4965f835b0c 100644 --- a/lisp/net/tramp-sh.el +++ b/lisp/net/tramp-sh.el @@ -271,14 +271,13 @@ The string is used in `tramp-methods'.") (tramp-remote-shell-args ("-c")) (tramp-connection-timeout 10))) ;;;###tramp-autoload -(add-to-list - 'tramp-methods - '("sg" - (tramp-login-program "sg") - (tramp-login-args (("-") ("%u"))) - (tramp-remote-shell "/bin/sh") - (tramp-remote-shell-args ("-c")) - (tramp-connection-timeout 10))) +(add-to-list 'tramp-methods + '("sg" + (tramp-login-program "sg") + (tramp-login-args (("-") ("%u"))) + (tramp-remote-shell "/bin/sh") + (tramp-remote-shell-args ("-c")) + (tramp-connection-timeout 10))) ;;;###tramp-autoload (add-to-list 'tramp-methods '("sudo" @@ -292,7 +291,8 @@ The string is used in `tramp-methods'.") (tramp-remote-shell "/bin/sh") (tramp-remote-shell-login ("-l")) (tramp-remote-shell-args ("-c")) - (tramp-connection-timeout 10))) + (tramp-connection-timeout 10) + (tramp-session-timeout 300))) ;;;###tramp-autoload (add-to-list 'tramp-methods '("doas" @@ -300,7 +300,8 @@ The string is used in `tramp-methods'.") (tramp-login-args (("-u" "%u") ("-s"))) (tramp-remote-shell "/bin/sh") (tramp-remote-shell-args ("-c")) - (tramp-connection-timeout 10))) + (tramp-connection-timeout 10) + (tramp-session-timeout 300))) ;;;###tramp-autoload (add-to-list 'tramp-methods '("ksu" @@ -4371,16 +4372,14 @@ Goes through the list `tramp-local-coding-commands' and vec 5 "Checking local encoding function `%s'" loc-enc) (tramp-message vec 5 "Checking local encoding command `%s' for sanity" loc-enc) - (unless (zerop (tramp-call-local-coding-command - loc-enc nil nil)) + (unless (zerop (tramp-call-local-coding-command loc-enc nil nil)) (throw 'wont-work-local nil))) (if (not (stringp loc-dec)) (tramp-message vec 5 "Checking local decoding function `%s'" loc-dec) (tramp-message vec 5 "Checking local decoding command `%s' for sanity" loc-dec) - (unless (zerop (tramp-call-local-coding-command - loc-dec nil nil)) + (unless (zerop (tramp-call-local-coding-command loc-dec nil nil)) (throw 'wont-work-local nil))) ;; Search for remote coding commands with the same format (while (and remote-commands (not found)) @@ -4702,6 +4701,19 @@ Goes through the list `tramp-inline-compress-commands'." " -o ControlPersist=no"))))))))) tramp-ssh-controlmaster-options))) +(defun tramp-timeout-session (vec) + "Close the connection VEC after a session timeout. +If there is just some editing, retry it after 5 seconds." + (if (and tramp-locked tramp-locker + (tramp-equal-remote vec tramp-current-connection)) + (progn + (tramp-message + vec 5 "Cannot timeout session, trying it again in %s seconds." 5) + (run-at-time 5 nil 'tramp-timeout-session vec)) + (tramp-message + vec 3 "Timeout session %s" (tramp-make-tramp-file-name vec 'localname)) + (tramp-cleanup-connection vec 'keep-debug))) + (defun tramp-maybe-open-connection (vec) "Maybe open a connection VEC. Does not do anything if a connection is already open, but re-opens the @@ -4878,6 +4890,14 @@ connection if a previous connection has died for some reason." :method l-method :user l-user :domain l-domain :host l-host :port l-port)) + ;; Set session timeout. + (when (tramp-get-method-parameter + hop 'tramp-session-timeout) + (tramp-set-connection-property + p "session-timeout" + (tramp-get-method-parameter + hop 'tramp-session-timeout))) + ;; Add login environment. (when login-env (setq @@ -4941,6 +4961,12 @@ connection if a previous connection has died for some reason." ;; Set connection-local variables. (tramp-set-connection-local-variables vec) + ;; Activate session timeout. + (when (tramp-get-connection-property p "session-timeout" nil) + (run-at-time + (tramp-get-connection-property p "session-timeout" nil) nil + 'tramp-timeout-session vec)) + ;; Make initial shell settings. (tramp-open-connection-setup-interactive-shell p vec) diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el index f16bb67efb5..8362d787525 100644 --- a/lisp/net/tramp.el +++ b/lisp/net/tramp.el @@ -248,6 +248,10 @@ pair of the form (KEY VALUE). The following KEYs are defined: In general, the global default value shall be used, but for some methods, like \"su\" or \"sudo\", a shorter timeout might be desirable. + * `tramp-session-timeout' + How long a Tramp connection keeps open before being disconnected. + This is useful for methods like \"su\" or \"sudo\", which + shouldn't run an open connection in the background forever. * `tramp-case-insensitive' Whether the remote file system handles file names case insensitive. Only a non-nil value counts, the default value nil means to @@ -4074,10 +4078,16 @@ Example: would yield t. On the other hand, the following check results in nil: - (tramp-equal-remote \"/sudo::/etc\" \"/su::/etc\")" - (and (tramp-tramp-file-p file1) - (tramp-tramp-file-p file2) - (string-equal (file-remote-p file1) (file-remote-p file2)))) + (tramp-equal-remote \"/sudo::/etc\" \"/su::/etc\") + +FILE1 and FILE2 could also be Tramp vectors." + (or (and (tramp-tramp-file-p file1) + (tramp-tramp-file-p file2) + (string-equal (file-remote-p file1) (file-remote-p file2))) + (and (tramp-file-name-p file1) + (tramp-file-name-p file2) + (string-equal (tramp-make-tramp-file-name file1 'localname) + (tramp-make-tramp-file-name file2 'localname))))) ;;;###tramp-autoload (defun tramp-mode-string-to-int (mode-string)