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authorSerge E. Hallyn <serue@us.ibm.com>2008-08-26 15:47:57 -0400
committerJames Morris <jmorris@namei.org>2008-08-26 18:54:08 -0400
commit93c06cbbf9fea5d5be1778febb7fa9ab1a74e5f5 (patch)
treede0ba51a2901097b7ab28483a040dc6ee5c9bc7d
parent3f23d815c5049c9d7022226cec2242e384dd0b43 (diff)
selinux: add support for installing a dummy policy (v2)
In August 2006 I posted a patch generating a minimal SELinux policy. This week, David P. Quigley posted an updated version of that as a patch against the kernel. It also had nice logic for auto-installing the policy. Following is David's original patch intro (preserved especially bc it has stats on the generated policies): se interested in the changes there were only two significant changes. The first is that the iteration through the list of classes used NULL as a sentinel value. The problem with this is that the class_to_string array actually has NULL entries in its table as place holders for the user space object classes. The second change was that it would seem at some point the initial sids table was NULL terminated. This is no longer the case so that iteration has to be done on array length instead of looking for NULL. Some statistics on the policy that it generates: The policy consists of 523 lines which contain no blank lines. Of those 523 lines 453 of them are class, permission, and initial sid definitions. These lines are usually little to no concern to the policy developer since they will not be adding object classes or permissions. Of the remaining 70 lines there is one type, one role, and one user statement. The remaining lines are broken into three portions. The first group are TE allow rules which make up 29 of the remaining lines, the second is assignment of labels to the initial sids which consist of 27 lines, and file system labeling statements which are the remaining 11. In addition to the policy.conf generated there is a single file_contexts file containing two lines which labels the entire system with base_t. This policy generates a policy.23 binary that is 7920 bytes. (then a few versions later...): The new policy is 587 lines (stripped of blank lines) with 476 of those lines being the boilerplate that I mentioned last time. The remaining 111 lines have the 3 lines for type, user, and role, 70 lines for the allow rules (one for each object class including user space object classes), 27 lines to assign types to the initial sids, and 11 lines for file system labeling. The policy binary is 9194 bytes. Changelog: Aug 26: Added Documentation/SELinux.txt Aug 26: Incorporated a set of comments by Stephen Smalley: 1. auto-setup SELINUXTYPE=dummy 2. don't auto-install if selinux is enabled with non-dummy policy 3. don't re-compute policy version 4. /sbin/setfiles not /usr/sbin/setfiles Aug 22: As per JMorris comments, made sure make distclean cleans up the mdp directory. Removed a check for file_contexts which is now created in the same file as the check, making it superfluous. Signed-off-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: David Quigley <dpquigl@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
-rw-r--r--Documentation/SELinux.txt27
-rw-r--r--scripts/Makefile3
-rw-r--r--scripts/selinux/Makefile2
-rw-r--r--scripts/selinux/README2
-rw-r--r--scripts/selinux/install_policy.sh69
-rw-r--r--scripts/selinux/mdp/Makefile5
-rw-r--r--scripts/selinux/mdp/dbus_contexts6
-rw-r--r--scripts/selinux/mdp/mdp.c242
8 files changed, 355 insertions, 1 deletions
diff --git a/Documentation/SELinux.txt b/Documentation/SELinux.txt
new file mode 100644
index 000000000000..07eae00f3314
--- /dev/null
+++ b/Documentation/SELinux.txt
@@ -0,0 +1,27 @@
1If you want to use SELinux, chances are you will want
2to use the distro-provided policies, or install the
3latest reference policy release from
4 http://oss.tresys.com/projects/refpolicy
5
6However, if you want to install a dummy policy for
7testing, you can do using 'mdp' provided under
8scripts/selinux. Note that this requires the selinux
9userspace to be installed - in particular you will
10need checkpolicy to compile a kernel, and setfiles and
11fixfiles to label the filesystem.
12
13 1. Compile the kernel with selinux enabled.
14 2. Type 'make' to compile mdp.
15 3. Make sure that you are not running with
16 SELinux enabled and a real policy. If
17 you are, reboot with selinux disabled
18 before continuing.
19 4. Run install_policy.sh:
20 cd scripts/selinux
21 sh install_policy.sh
22
23Step 4 will create a new dummy policy valid for your
24kernel, with a single selinux user, role, and type.
25It will compile the policy, will set your SELINUXTYPE to
26dummy in /etc/selinux/config, install the compiled policy
27as 'dummy', and relabel your filesystem.
diff --git a/scripts/Makefile b/scripts/Makefile
index 1c73c5aea66b..aafdf064feef 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -20,6 +20,7 @@ hostprogs-y += unifdef
20 20
21subdir-$(CONFIG_MODVERSIONS) += genksyms 21subdir-$(CONFIG_MODVERSIONS) += genksyms
22subdir-y += mod 22subdir-y += mod
23subdir-$(CONFIG_SECURITY_SELINUX) += selinux
23 24
24# Let clean descend into subdirs 25# Let clean descend into subdirs
25subdir- += basic kconfig package 26subdir- += basic kconfig package selinux
diff --git a/scripts/selinux/Makefile b/scripts/selinux/Makefile
new file mode 100644
index 000000000000..ca4b1ec01822
--- /dev/null
+++ b/scripts/selinux/Makefile
@@ -0,0 +1,2 @@
1subdir-y := mdp
2subdir- += mdp
diff --git a/scripts/selinux/README b/scripts/selinux/README
new file mode 100644
index 000000000000..a936315ba2c8
--- /dev/null
+++ b/scripts/selinux/README
@@ -0,0 +1,2 @@
1Please see Documentation/SELinux.txt for information on
2installing a dummy SELinux policy.
diff --git a/scripts/selinux/install_policy.sh b/scripts/selinux/install_policy.sh
new file mode 100644
index 000000000000..7b9ccf61f8f9
--- /dev/null
+++ b/scripts/selinux/install_policy.sh
@@ -0,0 +1,69 @@
1#!/bin/sh
2if [ `id -u` -ne 0 ]; then
3 echo "$0: must be root to install the selinux policy"
4 exit 1
5fi
6SF=`which setfiles`
7if [ $? -eq 1 ]; then
8 if [ -f /sbin/setfiles ]; then
9 SF="/usr/setfiles"
10 else
11 echo "no selinux tools installed: setfiles"
12 exit 1
13 fi
14fi
15
16cd mdp
17
18CP=`which checkpolicy`
19VERS=`$CP -V | awk '{print $1}'`
20
21./mdp policy.conf file_contexts
22$CP -o policy.$VERS policy.conf
23
24mkdir -p /etc/selinux/dummy/policy
25mkdir -p /etc/selinux/dummy/contexts/files
26
27cp file_contexts /etc/selinux/dummy/contexts/files
28cp dbus_contexts /etc/selinux/dummy/contexts
29cp policy.$VERS /etc/selinux/dummy/policy
30FC_FILE=/etc/selinux/dummy/contexts/files/file_contexts
31
32if [ ! -d /etc/selinux ]; then
33 mkdir -p /etc/selinux
34fi
35if [ ! -f /etc/selinux/config ]; then
36 cat > /etc/selinux/config << EOF
37SELINUX=enforcing
38SELINUXTYPE=dummy
39EOF
40else
41 TYPE=`cat /etc/selinux/config | grep "^SELINUXTYPE" | tail -1 | awk -F= '{ print $2 '}`
42 if [ "eq$TYPE" != "eqdummy" ]; then
43 selinuxenabled
44 if [ $? -eq 0 ]; then
45 echo "SELinux already enabled with a non-dummy policy."
46 echo "Exiting. Please install policy by hand if that"
47 echo "is what you REALLY want."
48 exit 1
49 fi
50 mv /etc/selinux/config /etc/selinux/config.mdpbak
51 grep -v "^SELINUXTYPE" /etc/selinux/config.mdpbak >> /etc/selinux/config
52 echo "SELINUXTYPE=dummy" >> /etc/selinux/config
53 fi
54fi
55
56cd /etc/selinux/dummy/contexts/files
57$SF file_contexts /
58
59mounts=`cat /proc/$$/mounts | egrep "ext2|ext3|xfs|jfs|ext4|ext4dev|gfs2" | awk '{ print $2 '}`
60$SF file_contexts $mounts
61
62
63dodev=`cat /proc/$$/mounts | grep "/dev "`
64if [ "eq$dodev" != "eq" ]; then
65 mount --move /dev /mnt
66 $SF file_contexts /dev
67 mount --move /mnt /dev
68fi
69
diff --git a/scripts/selinux/mdp/Makefile b/scripts/selinux/mdp/Makefile
new file mode 100644
index 000000000000..eb365b333441
--- /dev/null
+++ b/scripts/selinux/mdp/Makefile
@@ -0,0 +1,5 @@
1hostprogs-y := mdp
2HOST_EXTRACFLAGS += -Isecurity/selinux/include
3
4always := $(hostprogs-y)
5clean-files := $(hostprogs-y) policy.* file_contexts
diff --git a/scripts/selinux/mdp/dbus_contexts b/scripts/selinux/mdp/dbus_contexts
new file mode 100644
index 000000000000..116e684f9fc1
--- /dev/null
+++ b/scripts/selinux/mdp/dbus_contexts
@@ -0,0 +1,6 @@
1<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
2 "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
3<busconfig>
4 <selinux>
5 </selinux>
6</busconfig>
diff --git a/scripts/selinux/mdp/mdp.c b/scripts/selinux/mdp/mdp.c
new file mode 100644
index 000000000000..ca757d486187
--- /dev/null
+++ b/scripts/selinux/mdp/mdp.c
@@ -0,0 +1,242 @@
1/*
2 *
3 * mdp - make dummy policy
4 *
5 * When pointed at a kernel tree, builds a dummy policy for that kernel
6 * with exactly one type with full rights to itself.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 *
22 * Copyright (C) IBM Corporation, 2006
23 *
24 * Authors: Serge E. Hallyn <serue@us.ibm.com>
25 */
26
27#include <stdio.h>
28#include <stdlib.h>
29#include <unistd.h>
30#include <string.h>
31
32#include "flask.h"
33
34void usage(char *name)
35{
36 printf("usage: %s [-m] policy_file context_file\n", name);
37 exit(1);
38}
39
40void find_common_name(char *cname, char *dest, int len)
41{
42 char *start, *end;
43
44 start = strchr(cname, '_')+1;
45 end = strchr(start, '_');
46 if (!start || !end || start-cname > len || end-start > len) {
47 printf("Error with commons defines\n");
48 exit(1);
49 }
50 strncpy(dest, start, end-start);
51 dest[end-start] = '\0';
52}
53
54#define S_(x) x,
55static char *classlist[] = {
56#include "class_to_string.h"
57 NULL
58};
59#undef S_
60
61#include "initial_sid_to_string.h"
62
63#define TB_(x) char *x[] = {
64#define TE_(x) NULL };
65#define S_(x) x,
66#include "common_perm_to_string.h"
67#undef TB_
68#undef TE_
69#undef S_
70
71struct common {
72 char *cname;
73 char **perms;
74};
75struct common common[] = {
76#define TB_(x) { #x, x },
77#define S_(x)
78#define TE_(x)
79#include "common_perm_to_string.h"
80#undef TB_
81#undef TE_
82#undef S_
83};
84
85#define S_(x, y, z) {x, #y},
86struct av_inherit {
87 int class;
88 char *common;
89};
90struct av_inherit av_inherit[] = {
91#include "av_inherit.h"
92};
93#undef S_
94
95#include "av_permissions.h"
96#define S_(x, y, z) {x, y, z},
97struct av_perms {
98 int class;
99 int perm_i;
100 char *perm_s;
101};
102struct av_perms av_perms[] = {
103#include "av_perm_to_string.h"
104};
105#undef S_
106
107int main(int argc, char *argv[])
108{
109 int i, j, mls = 0;
110 char **arg, *polout, *ctxout;
111 int classlist_len, initial_sid_to_string_len;
112 FILE *fout;
113
114 if (argc < 3)
115 usage(argv[0]);
116 arg = argv+1;
117 if (argc==4 && strcmp(argv[1], "-m") == 0) {
118 mls = 1;
119 arg++;
120 }
121 polout = *arg++;
122 ctxout = *arg;
123
124 fout = fopen(polout, "w");
125 if (!fout) {
126 printf("Could not open %s for writing\n", polout);
127 usage(argv[0]);
128 }
129
130 classlist_len = sizeof(classlist) / sizeof(char *);
131 /* print out the classes */
132 for (i=1; i < classlist_len; i++) {
133 if(classlist[i])
134 fprintf(fout, "class %s\n", classlist[i]);
135 else
136 fprintf(fout, "class user%d\n", i);
137 }
138 fprintf(fout, "\n");
139
140 initial_sid_to_string_len = sizeof(initial_sid_to_string) / sizeof (char *);
141 /* print out the sids */
142 for (i=1; i < initial_sid_to_string_len; i++)
143 fprintf(fout, "sid %s\n", initial_sid_to_string[i]);
144 fprintf(fout, "\n");
145
146 /* print out the commons */
147 for (i=0; i< sizeof(common)/sizeof(struct common); i++) {
148 char cname[101];
149 find_common_name(common[i].cname, cname, 100);
150 cname[100] = '\0';
151 fprintf(fout, "common %s\n{\n", cname);
152 for (j=0; common[i].perms[j]; j++)
153 fprintf(fout, "\t%s\n", common[i].perms[j]);
154 fprintf(fout, "}\n\n");
155 }
156 fprintf(fout, "\n");
157
158 /* print out the class permissions */
159 for (i=1; i < classlist_len; i++) {
160 if (classlist[i]) {
161 int firstperm = -1, numperms = 0;
162
163 fprintf(fout, "class %s\n", classlist[i]);
164 /* does it inherit from a common? */
165 for (j=0; j < sizeof(av_inherit)/sizeof(struct av_inherit); j++)
166 if (av_inherit[j].class == i)
167 fprintf(fout, "inherits %s\n", av_inherit[j].common);
168
169 for (j=0; j < sizeof(av_perms)/sizeof(struct av_perms); j++) {
170 if (av_perms[j].class == i) {
171 if (firstperm == -1)
172 firstperm = j;
173 numperms++;
174 }
175 }
176 if (!numperms) {
177 fprintf(fout, "\n");
178 continue;
179 }
180
181 fprintf(fout, "{\n");
182 /* print out the av_perms */
183 for (j=0; j < numperms; j++) {
184 fprintf(fout, "\t%s\n", av_perms[firstperm+j].perm_s);
185 }
186 fprintf(fout, "}\n\n");
187 }
188 }
189 fprintf(fout, "\n");
190
191 /* NOW PRINT OUT MLS STUFF */
192 if (mls) {
193 printf("MLS not yet implemented\n");
194 exit(1);
195 }
196
197 /* types, roles, and allows */
198 fprintf(fout, "type base_t;\n");
199 fprintf(fout, "role base_r types { base_t };\n");
200 for (i=1; i < classlist_len; i++) {
201 if (classlist[i])
202 fprintf(fout, "allow base_t base_t:%s *;\n", classlist[i]);
203 else
204 fprintf(fout, "allow base_t base_t:user%d *;\n", i);
205 }
206 fprintf(fout, "user user_u roles { base_r };\n");
207 fprintf(fout, "\n");
208
209 /* default sids */
210 for (i=1; i < initial_sid_to_string_len; i++)
211 fprintf(fout, "sid %s user_u:base_r:base_t\n", initial_sid_to_string[i]);
212 fprintf(fout, "\n");
213
214
215 fprintf(fout, "fs_use_xattr ext2 user_u:base_r:base_t;\n");
216 fprintf(fout, "fs_use_xattr ext3 user_u:base_r:base_t;\n");
217 fprintf(fout, "fs_use_xattr jfs user_u:base_r:base_t;\n");
218 fprintf(fout, "fs_use_xattr xfs user_u:base_r:base_t;\n");
219 fprintf(fout, "fs_use_xattr reiserfs user_u:base_r:base_t;\n");
220
221 fprintf(fout, "fs_use_task pipefs user_u:base_r:base_t;\n");
222 fprintf(fout, "fs_use_task sockfs user_u:base_r:base_t;\n");
223
224 fprintf(fout, "fs_use_trans devpts user_u:base_r:base_t;\n");
225 fprintf(fout, "fs_use_trans tmpfs user_u:base_r:base_t;\n");
226 fprintf(fout, "fs_use_trans shm user_u:base_r:base_t;\n");
227
228 fprintf(fout, "genfscon proc / user_u:base_r:base_t\n");
229
230 fclose(fout);
231
232 fout = fopen(ctxout, "w");
233 if (!fout) {
234 printf("Wrote policy, but cannot open %s for writing\n", ctxout);
235 usage(argv[0]);
236 }
237 fprintf(fout, "/ user_u:base_r:base_t\n");
238 fprintf(fout, "/.* user_u:base_r:base_t\n");
239 fclose(fout);
240
241 return 0;
242}