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Diffstat (limited to 'lisp/net/tramp-androidsu.el')
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diff --git a/lisp/net/tramp-androidsu.el b/lisp/net/tramp-androidsu.el new file mode 100644 index 00000000000..09bee323f5e --- /dev/null +++ b/lisp/net/tramp-androidsu.el @@ -0,0 +1,561 @@ +;;; tramp-androidsu.el --- Tramp method for Android superuser shells -*- lexical-binding:t -*- + +;; Copyright (C) 2024 Free Software Foundation, Inc. + +;; Author: Po Lu +;; Keywords: comm, processes +;; Package: tramp + +;; This file is part of GNU Emacs. + +;; GNU Emacs is free software: you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation, either version 3 of the License, or +;; (at your option) any later version. + +;; GNU Emacs is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;; GNU General Public License for more details. + +;; You should have received a copy of the GNU General Public License +;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. + +;;; Commentary: + +;; `su' method implementation for Android. +;; +;; The `su' method struggles (as do other shell-based methods) with the +;; crippled versions of many Unix utilities installed on Android, +;; workarounds for which are implemented in the `adb' method. This +;; method defines a shell-based method that is identical in function to +;; and replaces if connecting to a local Android machine `su', but +;; reuses such code from the `adb' method where applicable and also +;; provides for certain mannerisms of popular Android `su' +;; implementations. + +;;; Code: + +(require 'tramp) +(require 'tramp-adb) +(require 'tramp-sh) + +;;;###tramp-autoload +(defconst tramp-androidsu-method "androidsu" + "When this method name is used, forward all calls to su.") + +;;;###tramp-autoload +(defcustom tramp-androidsu-mount-global-namespace t + "When non-nil, browse files from within the global mount namespace. +On systems that assign each application a unique view of the +filesystem by executing them within individual mount namespaces +and thus conceal each application's data directories from +others, invoke `su' with the option `-mm' in order for the shell +launched to run within the global mount namespace, so that Tramp +may edit files belonging to any and all applications." + :group 'tramp + :version "30.1" + :type 'boolean) + +;;;###tramp-autoload +(defcustom tramp-androidsu-remote-path '("/system/bin" + "/system/xbin") + "Directories in which to search for transfer programs and the like." + :group 'tramp + :version "30.1" + :type '(list string)) + +(defvar tramp-androidsu-su-mm-supported 'unknown + "Whether `su -mm' is supported on this system.") + +;;;###tramp-autoload +(defconst tramp-androidsu-local-shell-name "/system/bin/sh" + "Name of the local shell on Android.") + +;;;###tramp-autoload +(defconst tramp-androidsu-local-tmp-directory "/data/local/tmp" + "Name of the local temporary directory on Android.") + +;;;###tramp-autoload +(tramp--with-startup + (add-to-list 'tramp-methods + `(,tramp-androidsu-method + (tramp-login-program "su") + (tramp-login-args (("-") ("%u"))) + (tramp-remote-shell ,tramp-androidsu-local-shell-name) + (tramp-remote-shell-login ("-l")) + (tramp-remote-shell-args ("-c")) + (tramp-tmpdir ,tramp-androidsu-local-tmp-directory) + (tramp-connection-timeout 10) + (tramp-shell-name ,tramp-androidsu-local-shell-name))) + (add-to-list 'tramp-default-user-alist + `(,tramp-androidsu-method nil ,tramp-root-id-string))) + +(defvar android-use-exec-loader) ; androidfns.c. + +(defun tramp-androidsu-maybe-open-connection (vec) + "Open a connection VEC if not already open. +Mostly identical to `tramp-adb-maybe-open-connection', but also disables +multibyte mode and waits for the shell prompt to appear." + ;; During completion, don't reopen a new connection. + (unless (tramp-connectable-p vec) + (throw 'non-essential 'non-essential)) + + (with-tramp-debug-message vec "Opening connection" + (let ((p (tramp-get-connection-process vec)) + (process-name (tramp-get-connection-property vec "process-name")) + (process-environment (copy-sequence process-environment))) + ;; Open a new connection. + (condition-case err + (unless (process-live-p p) + (with-tramp-progress-reporter + vec 3 + (if (tramp-string-empty-or-nil-p (tramp-file-name-user vec)) + (format "Opening connection %s for %s using %s" + process-name + (tramp-file-name-host vec) + (tramp-file-name-method vec)) + (format "Opening connection %s for %s@%s using %s" + process-name + (tramp-file-name-user vec) + (tramp-file-name-host vec) + (tramp-file-name-method vec))) + (let* ((coding-system-for-read 'utf-8-unix) + (process-connection-type tramp-process-connection-type) + ;; The executable loader cannot execute setuid + ;; binaries, such as su. + (android-use-exec-loader nil) + (p (start-process (tramp-get-connection-name vec) + (tramp-get-connection-buffer vec) + ;; Disregard + ;; `tramp-encoding-shell', as + ;; there's no guarantee that it's + ;; possible to execute it with + ;; `android-use-exec-loader' off. + tramp-androidsu-local-shell-name "-i")) + (user (tramp-file-name-user vec)) + command) + ;; Set sentinel. Initialize variables. + (set-process-sentinel p #'tramp-process-sentinel) + (tramp-post-process-creation p vec) + ;; Replace `login-args' place holders. + (setq command (format "exec su - %s || exit" user)) + ;; Attempt to execute the shell inside the global mount + ;; namespace if requested. + (when tramp-androidsu-mount-global-namespace + (progn + (when (eq tramp-androidsu-su-mm-supported 'unknown) + ;; Change the prompt in advance so that + ;; `tramp-adb-send-command-and-check' can call + ;; `tramp-search-regexp'. + (tramp-adb-send-command + vec (format "PS1=%s PS2=''" + (tramp-shell-quote-argument + tramp-end-of-output))) + (setq tramp-androidsu-su-mm-supported + ;; Detect support for `su -mm'. + (tramp-adb-send-command-and-check + vec "su -mm -c 'exit 24'" 24))) + (when tramp-androidsu-su-mm-supported + (tramp-set-connection-property + vec "remote-namespace" t) + (setq command (format "exec su -mm - %s || exit" + user))))) + ;; Send the command. + (tramp-message vec 3 "Sending command `%s'" command) + (tramp-adb-send-command vec command t t) + ;; Android su binaries contact a background service to + ;; obtain authentication; during this process, input + ;; received is discarded, so input cannot be + ;; guaranteed to reach the root shell until its prompt + ;; is displayed. + (with-current-buffer (process-buffer p) + (tramp-wait-for-regexp p tramp-connection-timeout + "#[[:space:]]*$")) + ;; Set connection-local variables. + (tramp-set-connection-local-variables vec) + ;; Change prompt. + (tramp-adb-send-command + vec (format "PS1=%s PS2=''" + (tramp-shell-quote-argument tramp-end-of-output))) + ;; Disable line editing. + (tramp-adb-send-command + vec "set +o vi +o vi-esccomplete +o vi-tabcomplete +o emacs") + ;; Disable Unicode, for otherwise Unicode filenames will + ;; not be decoded correctly. + (tramp-adb-send-command vec "set +U") + ;; Dump option settings in the traces. + (when (>= tramp-verbose 9) + (tramp-adb-send-command vec "set -o")) + ;; Disable echo expansion. + (tramp-adb-send-command + vec "stty -inlcr -onlcr -echo kill '^U' erase '^H'" t) + ;; Check whether the echo has really been disabled. + ;; Some implementations, like busybox, don't support + ;; disabling. + (tramp-adb-send-command vec "echo foo" t) + (with-current-buffer (process-buffer p) + (goto-char (point-min)) + (when (looking-at-p "echo foo") + (tramp-set-connection-property p "remote-echo" t) + (tramp-message vec 5 "Remote echo still on. Ok.") + ;; Make sure backspaces and their echo are enabled + ;; and no line width magic interferes with them. + (tramp-adb-send-command + vec "stty icanon erase ^H cols 32767" t))) + ;; Mark it as connected. + (tramp-set-connection-property p "connected" t)))) + ;; Cleanup, and propagate the signal. + ((error quit) + (tramp-cleanup-connection vec t) + (signal (car err) (cdr err))))))) + +(defun tramp-androidsu-generate-wrapper (function) + "Return connection wrapper function for FUNCTION. +Return a function which temporarily substitutes local replacements for +the `adb' method's connection management functions around a call to +FUNCTION." + (lambda (&rest args) + (let ((tramp-adb-wait-for-output + (symbol-function #'tramp-adb-wait-for-output)) + (tramp-adb-maybe-open-connection + (symbol-function #'tramp-adb-maybe-open-connection))) + (unwind-protect + (progn + ;; `tramp-adb-wait-for-output' addresses problems introduced + ;; by the adb utility itself, not Android utilities, so + ;; replace it with the regular Tramp function. + (fset 'tramp-adb-wait-for-output #'tramp-wait-for-output) + ;; Likewise, except some special treatment is necessary on + ;; account of flaws in Android's su implementation. + (fset 'tramp-adb-maybe-open-connection + #'tramp-androidsu-maybe-open-connection) + (apply function args)) + ;; Restore the original definitions of the functions overridden + ;; above. + (fset 'tramp-adb-wait-for-output tramp-adb-wait-for-output) + (fset 'tramp-adb-maybe-open-connection + tramp-adb-maybe-open-connection))))) + +(defalias 'tramp-androidsu-handle-copy-file #'tramp-sh-handle-copy-file) + +(defalias 'tramp-androidsu-handle-delete-directory + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-delete-directory)) + +(defalias 'tramp-androidsu-handle-delete-file + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-delete-file)) + +(defalias 'tramp-androidsu-handle-directory-files-and-attributes + (tramp-androidsu-generate-wrapper + #'tramp-adb-handle-directory-files-and-attributes)) + +(defalias 'tramp-androidsu-handle-exec-path + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-exec-path)) + +(defalias 'tramp-androidsu-handle-file-attributes + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-file-attributes)) + +(defalias 'tramp-androidsu-handle-file-executable-p + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-file-executable-p)) + +(defalias 'tramp-androidsu-handle-file-exists-p + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-file-exists-p)) + +(defalias 'tramp-androidsu-handle-file-local-copy + #'tramp-sh-handle-file-local-copy) + +(defalias 'tramp-androidsu-handle-file-name-all-completions + (tramp-androidsu-generate-wrapper + #'tramp-adb-handle-file-name-all-completions)) + +(defalias 'tramp-androidsu-handle-file-readable-p + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-file-readable-p)) + +(defalias 'tramp-androidsu-handle-file-system-info + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-file-system-info)) + +(defalias 'tramp-androidsu-handle-file-writable-p + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-file-writable-p)) + +(defalias 'tramp-androidsu-handle-make-directory + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-make-directory)) + +(defun tramp-androidsu-handle-make-process (&rest args) + "Like `tramp-handle-make-process', but modified for Android." + (when args + (with-parsed-tramp-file-name (expand-file-name default-directory) nil + (let ((default-directory tramp-compat-temporary-file-directory) + (name (plist-get args :name)) + (buffer (plist-get args :buffer)) + (command (plist-get args :command)) + (coding (plist-get args :coding)) + (noquery (plist-get args :noquery)) + (connection-type + (or (plist-get args :connection-type) process-connection-type)) + (filter (plist-get args :filter)) + (sentinel (plist-get args :sentinel)) + (stderr (plist-get args :stderr))) + (unless (stringp name) + (signal 'wrong-type-argument (list #'stringp name))) + (unless (or (bufferp buffer) (string-or-null-p buffer)) + (signal 'wrong-type-argument (list #'bufferp buffer))) + (unless (consp command) + (signal 'wrong-type-argument (list #'consp command))) + (unless (or (null coding) + (and (symbolp coding) (memq coding coding-system-list)) + (and (consp coding) + (memq (car coding) coding-system-list) + (memq (cdr coding) coding-system-list))) + (signal 'wrong-type-argument (list #'symbolp coding))) + (when (eq connection-type t) + (setq connection-type 'pty)) + (unless (or (and (consp connection-type) + (memq (car connection-type) '(nil pipe pty)) + (memq (cdr connection-type) '(nil pipe pty))) + (memq connection-type '(nil pipe pty))) + (signal 'wrong-type-argument (list #'symbolp connection-type))) + (unless (or (null filter) (eq filter t) (functionp filter)) + (signal 'wrong-type-argument (list #'functionp filter))) + (unless (or (null sentinel) (functionp sentinel)) + (signal 'wrong-type-argument (list #'functionp sentinel))) + (unless (or (null stderr) (bufferp stderr)) + (signal 'wrong-type-argument (list #'bufferp stderr))) + (let* ((buffer + (if buffer + (get-buffer-create buffer) + ;; BUFFER can be nil. We use a temporary buffer. + (generate-new-buffer tramp-temp-buffer-name))) + (orig-command command) + (env (mapcar + (lambda (elt) + (when (tramp-compat-string-search "=" elt) elt)) + tramp-remote-process-environment)) + ;; We use as environment the difference to toplevel + ;; `process-environment'. + (env (dolist (elt process-environment env) + (when + (and + (tramp-compat-string-search "=" elt) + (not + (member + elt (default-toplevel-value 'process-environment)))) + (setq env (cons elt env))))) + ;; Add remote path if exists. + (env (let ((remote-path + (string-join (tramp-get-remote-path v) ":"))) + (setenv-internal env "PATH" remote-path 'keep))) + (env (setenv-internal + env "INSIDE_EMACS" (tramp-inside-emacs) 'keep)) + (env (mapcar #'tramp-shell-quote-argument (delq nil env))) + ;; Quote command. + (command (mapconcat #'tramp-shell-quote-argument command " ")) + ;; Set cwd and environment variables. + (command + (append + `("cd" ,(tramp-shell-quote-argument localname) "&&" "(" "env") + env `(,command ")"))) + ;; Add remote shell if needed. + (command + (if (consp (tramp-get-method-parameter v 'tramp-direct-async)) + (append + (tramp-get-method-parameter v 'tramp-direct-async) + `(,(string-join command " "))) + command)) + p) + ;; Generate a command to start the process using `su' with + ;; suitable options for specifying the mount namespace and + ;; suchlike. + (setq + p (make-process + :name name :buffer buffer + :command (if (tramp-get-connection-property v "remote-namespace") + (append (list "su" "-mm" "-" user "-c") command) + (append (list "su" "-" user "-c") command)) + :coding coding :noquery noquery :connection-type connection-type + :sentinel sentinel :stderr stderr)) + ;; Set filter. Prior Emacs 29.1, it doesn't work reliably + ;; to provide it as `make-process' argument when filter is + ;; t. See Bug#51177. + (when filter + (set-process-filter p filter)) + (tramp-post-process-creation p v) + ;; Query flag is overwritten in `tramp-post-process-creation', + ;; so we reset it. + (set-process-query-on-exit-flag p (null noquery)) + ;; This is needed for ssh or PuTTY based processes, and + ;; only if the respective options are set. Perhaps, the + ;; setting could be more fine-grained. + ;; (process-put p 'tramp-shared-socket t) + (process-put p 'remote-command orig-command) + (tramp-set-connection-property p "remote-command" orig-command) + (when (bufferp stderr) + (tramp-taint-remote-process-buffer stderr)) + p))))) + +(defalias 'tramp-androidsu-handle-make-symbolic-link + #'tramp-sh-handle-make-symbolic-link) + +(defalias 'tramp-androidsu-handle-process-file + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-process-file)) + +(defalias 'tramp-androidsu-handle-rename-file #'tramp-sh-handle-rename-file) + +(defalias 'tramp-androidsu-handle-set-file-modes + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-set-file-modes)) + +(defalias 'tramp-androidsu-handle-set-file-times + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-set-file-times)) + +(defalias 'tramp-androidsu-handle-get-remote-gid + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-get-remote-gid)) + +(defalias 'tramp-androidsu-handle-get-remote-groups + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-get-remote-groups)) + +(defalias 'tramp-androidsu-handle-get-remote-uid + (tramp-androidsu-generate-wrapper #'tramp-adb-handle-get-remote-uid)) + +(defalias 'tramp-androidsu-handle-write-region #'tramp-sh-handle-write-region) + +;;;###tramp-autoload +(defconst tramp-androidsu-file-name-handler-alist + '(;; `abbreviate-file-name' performed by default handler. + (access-file . tramp-handle-access-file) + (add-name-to-file . tramp-handle-add-name-to-file) + ;; `byte-compiler-base-file-name' performed by default handler. + (copy-directory . tramp-handle-copy-directory) + (copy-file . tramp-androidsu-handle-copy-file) + (delete-directory . tramp-androidsu-handle-delete-directory) + (delete-file . tramp-androidsu-handle-delete-file) + ;; `diff-latest-backup-file' performed by default handler. + (directory-file-name . tramp-handle-directory-file-name) + (directory-files . tramp-handle-directory-files) + (directory-files-and-attributes + . tramp-androidsu-handle-directory-files-and-attributes) + (dired-compress-file . ignore) + (dired-uncache . tramp-handle-dired-uncache) + (exec-path . tramp-androidsu-handle-exec-path) + (expand-file-name . tramp-handle-expand-file-name) + (file-accessible-directory-p . tramp-handle-file-accessible-directory-p) + (file-acl . ignore) + (file-attributes . tramp-androidsu-handle-file-attributes) + (file-directory-p . tramp-handle-file-directory-p) + (file-equal-p . tramp-handle-file-equal-p) + (file-executable-p . tramp-androidsu-handle-file-executable-p) + (file-exists-p . tramp-androidsu-handle-file-exists-p) + (file-group-gid . tramp-handle-file-group-gid) + (file-in-directory-p . tramp-handle-file-in-directory-p) + (file-local-copy . tramp-androidsu-handle-file-local-copy) + (file-locked-p . tramp-handle-file-locked-p) + (file-modes . tramp-handle-file-modes) + (file-name-all-completions + . tramp-androidsu-handle-file-name-all-completions) + (file-name-as-directory . tramp-handle-file-name-as-directory) + (file-name-case-insensitive-p . tramp-handle-file-name-case-insensitive-p) + (file-name-completion . tramp-handle-file-name-completion) + (file-name-directory . tramp-handle-file-name-directory) + (file-name-nondirectory . tramp-handle-file-name-nondirectory) + ;; `file-name-sans-versions' performed by default handler. + (file-newer-than-file-p . tramp-handle-file-newer-than-file-p) + (file-notify-add-watch . tramp-handle-file-notify-add-watch) + (file-notify-rm-watch . tramp-handle-file-notify-rm-watch) + (file-notify-valid-p . tramp-handle-file-notify-valid-p) + (file-ownership-preserved-p . ignore) + (file-readable-p . tramp-androidsu-handle-file-readable-p) + (file-regular-p . tramp-handle-file-regular-p) + (file-remote-p . tramp-handle-file-remote-p) + (file-selinux-context . tramp-handle-file-selinux-context) + (file-symlink-p . tramp-handle-file-symlink-p) + (file-system-info . tramp-androidsu-handle-file-system-info) + (file-truename . tramp-handle-file-truename) + (file-user-uid . tramp-handle-file-user-uid) + (file-writable-p . tramp-androidsu-handle-file-writable-p) + (find-backup-file-name . tramp-handle-find-backup-file-name) + ;; `get-file-buffer' performed by default handler. + (insert-directory . tramp-handle-insert-directory) + (insert-file-contents . tramp-handle-insert-file-contents) + (list-system-processes . tramp-handle-list-system-processes) + (load . tramp-handle-load) + (lock-file . tramp-handle-lock-file) + (make-auto-save-file-name . tramp-handle-make-auto-save-file-name) + (make-directory . tramp-androidsu-handle-make-directory) + (make-directory-internal . ignore) + (make-lock-file-name . tramp-handle-make-lock-file-name) + (make-nearby-temp-file . tramp-handle-make-nearby-temp-file) + (make-process . tramp-androidsu-handle-make-process) + (make-symbolic-link . tramp-androidsu-handle-make-symbolic-link) + (memory-info . tramp-handle-memory-info) + (process-attributes . tramp-handle-process-attributes) + (process-file . tramp-androidsu-handle-process-file) + (rename-file . tramp-androidsu-handle-rename-file) + (set-file-acl . ignore) + (set-file-modes . tramp-androidsu-handle-set-file-modes) + (set-file-selinux-context . ignore) + (set-file-times . tramp-androidsu-handle-set-file-times) + (set-visited-file-modtime . tramp-handle-set-visited-file-modtime) + (shell-command . tramp-handle-shell-command) + (start-file-process . tramp-handle-start-file-process) + (substitute-in-file-name . tramp-handle-substitute-in-file-name) + (temporary-file-directory . tramp-handle-temporary-file-directory) + (tramp-get-home-directory . ignore) + (tramp-get-remote-gid . tramp-androidsu-handle-get-remote-gid) + (tramp-get-remote-groups . tramp-androidsu-handle-get-remote-groups) + (tramp-get-remote-uid . tramp-androidsu-handle-get-remote-uid) + (tramp-set-file-uid-gid . ignore) + (unhandled-file-name-directory . ignore) + (unlock-file . tramp-handle-unlock-file) + (vc-registered . ignore) + (verify-visited-file-modtime . tramp-handle-verify-visited-file-modtime) + (write-region . tramp-androidsu-handle-write-region)) + "Alist of Tramp handler functions for superuser sessions on Android.") + +;; It must be a `defsubst' in order to push the whole code into +;; tramp-loaddefs.el. Otherwise, there would be recursive autoloading. +;;;###tramp-autoload +(defsubst tramp-androidsu-file-name-p (vec-or-filename) + "Check whether VEC-OR-FILENAME is for the `androidsu' method." + (when-let* ((vec (tramp-ensure-dissected-file-name vec-or-filename))) + (equal (tramp-file-name-method vec) tramp-androidsu-method))) + +;;;###tramp-autoload +(defun tramp-androidsu-file-name-handler (operation &rest args) + "Invoke the `androidsu' handler for OPERATION. +First arg specifies the OPERATION, second arg is a list of +arguments to pass to the OPERATION." + (if-let ((fn (assoc operation tramp-androidsu-file-name-handler-alist))) + (prog1 (save-match-data (apply (cdr fn) args)) + (setq tramp-debug-message-fnh-function (cdr fn))) + (prog1 (tramp-run-real-handler operation args) + (setq tramp-debug-message-fnh-function operation)))) + +;;;###tramp-autoload +(tramp--with-startup + (tramp-register-foreign-file-name-handler + #'tramp-androidsu-file-name-p #'tramp-androidsu-file-name-handler)) + +;;; Default connection-local variables for Tramp. + +(defconst tramp-androidsu-connection-local-default-variables + `((tramp-remote-path . ,tramp-androidsu-remote-path)) + "Default connection-local variables for remote androidsu connections.") + +(connection-local-set-profile-variables + 'tramp-androidsu-connection-local-default-profile + tramp-androidsu-connection-local-default-variables) + +(connection-local-set-profiles + `(:application tramp :protocol ,tramp-androidsu-method) + 'tramp-androidsu-connection-local-default-profile) + +(with-eval-after-load 'shell + (connection-local-set-profiles + `(:application tramp :protocol ,tramp-androidsu-method) + 'tramp-adb-connection-local-default-shell-profile + 'tramp-adb-connection-local-default-ps-profile)) + +(add-hook 'tramp-unload-hook + (lambda () + (unload-feature 'tramp-androidsu 'force))) + +(provide 'tramp-androidsu) +;;; tramp-androidsu.el ends here |