Generate policy for Admin API calls based on annotations on actual methods

This ease Admin API administration, and also adds checking if qrexec
policy + scripts matches actual Admin API methods implementation.
The idea is to classify every Admin API method as either local
read-only, local read-write, global read-only or global read-write.
Where local/global means affecting a single VM, or the whole system.

See QubesOS/qubes-issues#2871 for details.

Fixes QubesOS/qubes-issues#2871

Makefile

@@ -8,7 +8,6 @@ OS ?= Linux
 PYTHON ?= python3
 
 ADMIN_API_METHODS_SIMPLE = \
-	admin.vm.List \
 	admin.vmclass.List \
 	admin.Events \
 	admin.backup.Execute \
@@ -17,6 +16,7 @@ ADMIN_API_METHODS_SIMPLE = \
 	admin.label.Create \
 	admin.label.Get \
 	admin.label.List \
+	admin.label.Index \
 	admin.label.Remove \
 	admin.pool.Add \
 	admin.pool.Info \
@@ -84,6 +84,7 @@ ADMIN_API_METHODS_SIMPLE = \
 	admin.vm.tag.List \
 	admin.vm.tag.Remove \
 	admin.vm.tag.Set \
+	admin.vm.volume.Clone \
 	admin.vm.volume.Info \
 	admin.vm.volume.List \
 	admin.vm.volume.ListSnapshots \
@@ -91,10 +92,6 @@ ADMIN_API_METHODS_SIMPLE = \
 	admin.vm.volume.Revert \
 	$(null)
 
-ADMIN_API_METHODS := $(ADMIN_API_METHODS_SIMPLE) \
-	 admin.vm.volume.Import \
-	 $(null)
-
 ifeq ($(OS),Linux)
 DATADIR ?= /var/lib/qubes
 STATEDIR ?= /var/run/qubes
@@ -173,15 +170,26 @@ endif
 	install qubes-rpc/qubesd-query-fast $(DESTDIR)/usr/libexec/qubes/
 	for method in $(ADMIN_API_METHODS_SIMPLE); do \
 		ln -s ../../usr/libexec/qubes/qubesd-query-fast \
-			$(DESTDIR)/etc/qubes-rpc/$$method; \
+			$(DESTDIR)/etc/qubes-rpc/$$method || exit 1; \
 	done
 	install qubes-rpc/admin.vm.volume.Import $(DESTDIR)/etc/qubes-rpc/
-	for method in $(ADMIN_API_METHODS); do \
-		install -m 0644 qubes-rpc-policy/admin-default \
-			$(DESTDIR)/etc/qubes-rpc/policy/$$method; \
+	PYTHONPATH=.:test-packages qubes-rpc-policy/generate-admin-policy \
+		--destdir=$(DESTDIR)/etc/qubes-rpc/policy \
+		--exclude admin.vm.Create.AdminVM \
+				  admin.vm.CreateInPool.AdminVM \
+		          admin.vm.device.testclass.Attach \
+				  admin.vm.device.testclass.Detach \
+				  admin.vm.device.testclass.List \
+				  admin.vm.device.testclass.Available
+	# sanity check
+	for method in $(DESTDIR)/etc/qubes-rpc/policy/admin.*; do \
+		ls $(DESTDIR)/etc/qubes-rpc/$$(basename $$method) >/dev/null || exit 1; \
 	done
 	install -d $(DESTDIR)/etc/qubes-rpc/policy/include
-	install -m 0644 qubes-rpc-policy/admin-all \
+	install -m 0644 qubes-rpc-policy/admin-local-ro \
+		qubes-rpc-policy/admin-local-rwx \
+		qubes-rpc-policy/admin-global-ro \
+		qubes-rpc-policy/admin-global-rwx \
 		$(DESTDIR)/etc/qubes-rpc/policy/include/
 
 	mkdir -p "$(DESTDIR)$(FILESDIR)"

qubes-rpc-policy/admin-default

@@ -1,13 +0,0 @@
-## Note that policy parsing stops at the first match,
-## so adding anything below "$anyvm $anyvm action" line will have no effect
-
-## Please use a single # to start your custom comments
-
-## Add your entries here, make sure to append ",target=dom0" to all allow/ask actions
-
-## Include a single file for all admin.* methods to ease setting up Management VM.
-## To allow only specific actions, edit specific policy file, like this one. To
-## allow all of them, edit /etc/qubes-rpc/include/admin-all.
-$include:/etc/qubes-rpc/policy/include/admin-all
-
-$anyvm $anyvm deny

qubes-rpc-policy/admin-global-ro

@@ -0,0 +1,13 @@
+## This file is included from all global read-only admin.* policy files
+## _in default configuration_. To allow only specific action,
+## edit specific policy file.
+
+## Note that policy parsing stops at the first match,
+
+## Please use a single # to start your custom comments
+
+## Include all already having write access
+$include:include/admin-global-rwx
+
+## Add your entries here, make sure to append ",target=dom0" to all allow/ask actions
+

qubes-rpc-policy/admin-global-rwx

@@ -0,0 +1,11 @@
+## This file is included from all global read-write admin.* policy files
+## _in default configuration_. To allow only specific action,
+## edit specific policy file.
+
+## Note that policy parsing stops at the first match,
+## so adding anything below "$anyvm $anyvm action" line will have no effect
+
+## Please use a single # to start your custom comments
+
+## Add your entries here, make sure to append ",target=dom0" to all allow/ask actions
+

qubes-rpc-policy/admin-local-ro

@@ -0,0 +1,14 @@
+## This file is included from all local read-only admin.* policy files
+## _in default configuration_. To allow only specific action,
+## edit specific policy file.
+
+## Note that policy parsing stops at the first match,
+## so adding anything below "$anyvm $anyvm action" line will have no effect
+
+## Please use a single # to start your custom comments
+
+## Include all already having write access
+$include:include/admin-local-rwx
+
+## Add your entries here, make sure to append ",target=dom0" to all allow/ask actions
+

qubes-rpc-policy/admin-local-rwx

@@ -1,5 +1,6 @@
-## This file is included from all admin.* policy files _in default
-## configuration_. To allow only specific action, edit specific policy file.
+## This file is included from all local read-write admin.* policy files
+## _in default configuration_. To allow only specific action,
+## edit specific policy file.
 
 ## Note that policy parsing stops at the first match,
 ## so adding anything below "$anyvm $anyvm action" line will have no effect
@@ -8,4 +9,3 @@
 
 ## Add your entries here, make sure to append ",target=dom0" to all allow/ask actions
 
-$anyvm $anyvm deny

qubes-rpc-policy/generate-admin-policy

@@ -0,0 +1,95 @@
+#!/usr/bin/python3
+# coding=utf-8
+# The Qubes OS Project, https://www.qubes-os.org/
+#
+# Copyright (C) 2017  Marek Marczykowski-Górecki
+#                                   <marmarek@invisiblethingslab.com>
+#
+# This program 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 2 of the License, or
+# (at your option) any later version.
+#
+# This program 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, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+import argparse
+import os
+
+import sys
+
+import qubes.api.admin
+
+parser = argparse.ArgumentParser(
+    description='Generate default Admin API policy')
+parser.add_argument('--include-base', action='store',
+    default='/etc/qubes-rpc/policy/include',
+    help='Base path for included paths (default: %(default)s)')
+parser.add_argument('--destdir', action='store',
+    default='/etc/qubes-rpc/policy',
+    help='Directory where write output files to (default: %(default)s)')
+parser.add_argument('--verbose', action='store_true', default=False,
+    help='Be verbose')
+parser.add_argument('--exclude', action='store', nargs='*',
+    help='Exclude service')
+parser.add_argument('service', nargs='*', action='store',
+    help='Generate policy for those services (default: all)')
+
+default_policy_header = '''\
+## Note that policy parsing stops at the first match.
+
+## Please use a single # to start your custom comments
+
+## Add your entries here, make sure to append ",target=dom0" to all allow/ask actions
+
+## Include a common file for all admin.* methods to ease setting up
+## Management VM.
+## To allow only specific actions, edit specific policy file, like this one. To
+## allow all of them, edit appropriate /etc/qubes-rpc/include/admin-*.
+
+'''
+
+def write_default_policy(args, apiname, clasifiers):
+    ''' Write single default policy for given API call '''
+    assert 'scope' in clasifiers, \
+        'Method {} lack scope classifier'.format(apiname)
+    assert any(attr in clasifiers for attr in ('read', 'write', 'execute')), \
+        'Method {} lack read/write/execute classifier'.format(apiname)
+    assert clasifiers['scope'] in ('local', 'global'), \
+        'Method {} have invalid scope: {}'.format(apiname, clasifiers['scope'])
+
+    file_to_include = 'admin-{scope}-{rwx}'.format(
+        scope=clasifiers['scope'],
+        rwx=('rwx' if clasifiers.get('write', False) or
+                      clasifiers.get('execute', False)
+        else 'ro'))
+
+    if args.verbose:
+        print('Service {}: include {}'.format(apiname, file_to_include),
+            file=sys.stderr)
+    with open(os.path.join(args.destdir, apiname), 'w') as f:
+        f.write(default_policy_header)
+        f.write('$include:{}\n'.format(
+            os.path.join(args.include_base, file_to_include)))
+
+
+def main(args=None):
+    ''' Main function of default-admin-policy tool'''
+    args = parser.parse_args(args)
+
+    for func, apiname, _ in qubes.api.admin.QubesAdminAPI.list_methods():
+        if args.service and apiname not in args.service:
+            continue
+        if args.exclude and apiname in args.exclude:
+            continue
+        write_default_policy(args, apiname, func.classifiers)
+
+
+if __name__ == '__main__':
+    sys.exit(main())

rpm_spec/core-dom0.spec

@@ -410,7 +410,10 @@ fi
 /etc/xen/scripts/block-origin
 /etc/xen/scripts/vif-route-qubes
 %attr(0664,root,qubes) %config(noreplace) /etc/qubes-rpc/policy/admin.*
-%attr(0664,root,qubes) %config(noreplace) /etc/qubes-rpc/policy/include/admin-all
+%attr(0664,root,qubes) %config(noreplace) /etc/qubes-rpc/policy/include/admin-local-ro
+%attr(0664,root,qubes) %config(noreplace) /etc/qubes-rpc/policy/include/admin-local-rwx
+%attr(0664,root,qubes) %config(noreplace) /etc/qubes-rpc/policy/include/admin-global-ro
+%attr(0664,root,qubes) %config(noreplace) /etc/qubes-rpc/policy/include/admin-global-rwx
 %attr(0664,root,qubes) %config(noreplace) /etc/qubes-rpc/policy/qubes.FeaturesRequest
 %attr(0664,root,qubes) %config(noreplace) /etc/qubes-rpc/policy/qubes.Filecopy
 %attr(0664,root,qubes) %config(noreplace) /etc/qubes-rpc/policy/qubes.GetImageRGBA