attempt to implement :AS connection type and AS combinator

Signed-off-by: Sean Whitton <spwhitton@spwhitton.name>

1 files changed, 36 insertions, 0 deletions

diff --git a/src/connection/as.lisp b/src/connection/as.lisp
new file mode 100644
index 0000000..b5a9f69
--- /dev/null
+++ b/src/connection/as.lisp
@@ -0,0 +1,36 @@
+;;; Consfigurator -- Lisp declarative configuration management system
+
+;;; Copyright (C) 2021  Sean Whitton <spwhitton@spwhitton.name>
+
+;;; This file 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, or (at your option)
+;;; any later version.
+
+;;; This file 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+(in-package :consfigurator.connection.as)
+(named-readtables:in-readtable :consfigurator)
+
+;; currently we only check whether we're root, but, for example, on Linux, we
+;; might have a CAP_* which lets us setuid as non-root
+(defun can-setuid ()
+  (zerop (foreign-funcall "geteuid" :int)))
+
+(defmethod establish-connection ((type (eql :as)) remaining &key to)
+  "Establish a :SETUID or :SUDO connection to another user account, depending
+on whether it is possible to establish a :SETUID connection.
+
+This connection type does not support sudo with a password -- it is designed
+to be used as root."
+  (if (and (lisp-connection-p)
+           (can-setuid)
+           (can-probably-fork))
+      (establish-connection :setuid remaining :to to)
+      (establish-connection :sudo remaining :user to)))