Add validation that all APIs contain ACL checks

Add a script which parses the driver API code and validates
that every API registered in a virNNNDriverPtr table contains
an ACL check matching the API name.

NB this currently whitelists a few xen driver functions
which are temporarily lacking in access control checks.
The xen driver is considered insecure until these are
fixed.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

src/Makefile.am

@@ -478,16 +478,34 @@ DRIVER_SOURCE_FILES = \
 	$(XENAPI_DRIVER_SOURCES) \
 	$(NULL)
 
+STATEFUL_DRIVER_SOURCE_FILES = \
+	$(INTERFACE_DRIVER_SOURCES) \
+	$(LIBXL_DRIVER_SOURCES) \
+	$(LXC_DRIVER_SOURCES) \
+	$(NETWORK_DRIVER_SOURCES) \
+	$(NODE_DEVICE_DRIVER_SOURCES) \
+	$(NWFILTER_DRIVER_SOURCES) \
+	$(QEMU_DRIVER_SOURCES) \
+	$(SECRET_DRIVER_SOURCES) \
+	$(STORAGE_DRIVER_SOURCES) \
+	$(UML_DRIVER_SOURCES) \
+	$(XEN_DRIVER_SOURCES) \
+	$(NULL)
+
 
 check-driverimpls:
 	$(AM_V_GEN)$(PERL) $(srcdir)/check-driverimpls.pl \
 		$(filter /%,$(DRIVER_SOURCE_FILES)) \
 		$(addprefix $(srcdir)/,$(filter-out /%,$(DRIVER_SOURCE_FILES)))
 
-EXTRA_DIST += check-driverimpls.pl
+check-aclrules:
+	$(AM_V_GEN)$(PERL) $(srcdir)/check-aclrules.pl \
+		$(STATEFUL_DRIVER_SOURCE_FILES)
+
+EXTRA_DIST += check-driverimpls.pl check-aclrules.pl
 
 check-local: check-protocol check-symfile check-symsorting \
-	check-drivername check-driverimpls
+	check-drivername check-driverimpls check-aclrules
 .PHONY: check-protocol $(PROTOCOL_STRUCTS:structs=struct)
 
 # Mock driver, covering domains, storage, networks, etc

src/check-aclrules.pl

+#!/usr/bin/perl
+#
+# Copyright (C) 2013 Red Hat, Inc.
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library.  If not, see
+# <http://www.gnu.org/licenses/>.
+#
+# This script validates that the driver implementation of any
+# public APIs contain ACL checks.
+#
+# As the script reads each source file, it attempts to identify
+# top level function names.
+#
+# When reading the body of the functions, it looks for anything
+# that looks like an API called named  XXXEnsureACL. It will
+# validate that the XXX prefix matches the name of the function
+# it occurs in.
+#
+# When it later finds the virDriverPtr table, for each entry
+# point listed, it will validate if there was a previously
+# detected EnsureACL call recorded.
+#
+use strict;
+use warnings;
+
+my $status = 0;
+
+my $brace = 0;
+my $maybefunc;
+my $intable = 0;
+my $table;
+
+my %acls;
+
+my %whitelist = (
+    "connectClose" => 1,
+    "connectIsEncrypted" => 1,
+    "connectIsSecure" => 1,
+    "connectIsAlive" => 1,
+    "networkOpen" => 1,
+    "networkClose" => 1,
+    "nwfilterOpen" => 1,
+    "nwfilterClose" => 1,
+    "secretOpen" => 1,
+    "secretClose" => 1,
+    "storageOpen" => 1,
+    "storageClose" => 1,
+    "interfaceOpen" => 1,
+    "interfaceClose" => 1,
+    );
+
+# Temp hack - remove it once xen driver is fixed
+my %implwhitelist = (
+    "xenUnifiedDomainRestore" => 1,
+    "xenUnifiedDomainRestoreFlags" => 1,
+    "xenUnifiedDomainMigratePrepare" => 1,
+    "xenUnifiedNodeDeviceDettach" => 1,
+    "xenUnifiedNodeDeviceDetachFlags" => 1,
+    "xenUnifiedNodeDeviceReset" => 1,
+    "xenUnifiedDomainIsActive" => 1,
+    "xenUnifiedDomainIsPersistent" => 1,
+    "xenUnifiedDomainIsUpdated" => 1,
+    "xenUnifiedDomainOpenConsole" => 1,
+    );
+
+my $lastfile;
+
+while (<>) {
+    if (!defined $lastfile ||
+        $lastfile ne $ARGV) {
+        %acls = ();
+        $brace = 0;
+        $maybefunc = undef;
+        $lastfile = $ARGV;
+    }
+    if ($brace == 0) {
+        # Looks for anything which appears to be a function
+        # body name. Doesn't matter if we pick up bogus stuff
+        # here, as long as we don't miss valid stuff
+        if (m,\b(\w+)\(,) {
+            $maybefunc = $1;
+        }
+    } elsif ($brace > 0) {
+        if (m,(\w+)EnsureACL,) {
+            # Record the fact that maybefunc contains an
+            # ACL call, and make sure it is the right call!
+            my $func = $1;
+            $func =~ s/^vir//;
+            if (!defined $maybefunc) {
+                print "$ARGV:$. Unexpected check '$func' outside function\n";
+                $status = 1;
+            } else {
+                unless ($maybefunc =~ /$func$/i) {
+                    print "$ARGV:$. Mismatch check 'vir${func}EnsureACL' for function '$maybefunc'\n";
+                    $status = 1;
+                }
+            }
+            $acls{$maybefunc} = 1;
+        } elsif (m,\b(\w+)\(,) {
+            # Handles case where we replaced an API with a new
+            # one which  adds new parameters, and we're left with
+            # a simple stub calling the new API.
+            my $callfunc = $1;
+            if (exists $acls{$callfunc}) {
+                $acls{$maybefunc} = 1;
+            }
+        }
+    }
+
+    # Pass the vir*DriverPtr tables and make sure that
+    # every func listed there, has an impl which calls
+    # an ACL function
+    if ($intable) {
+        if (/\}/) {
+            $intable = 0;
+            $table = undef;
+        } elsif (/\.(\w+)\s*=\s*(\w+),?/) {
+            my $api = $1;
+            my $impl = $2;
+
+            if ($api ne "no" &&
+                $api ne "name" &&
+                $table ne "virStateDriver" &&
+                !exists $acls{$impl} &&
+                !exists $whitelist{$api} &&
+                !exists $implwhitelist{$impl}) {
+                print "$ARGV:$. Missing ACL check in function '$impl' for '$api'\n";
+                $status = 1;
+            }
+        }
+    } elsif (/^(?:static\s+)?(vir(?:\w+)?Driver)\s+/) {
+        if ($1 ne "virNWFilterCallbackDriver" &&
+            $1 ne "virNWFilterTechDriver" &&
+            $1 ne "virDomainConfNWFilterDriver") {
+            $intable = 1;
+            $table = $1;
+        }
+    }
+
+
+    my $count;
+    $count = s/{//g;
+    $brace += $count;
+    $count = s/}//g;
+    $brace -= $count;
+}
+
+exit $status;