1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * mdp - make dummy policy
5 *
6 * When pointed at a kernel tree, builds a dummy policy for that kernel
7 * with exactly one type with full rights to itself.
8 *
9 * Copyright (C) IBM Corporation, 2006
10 *
11 * Authors: Serge E. Hallyn <serue@us.ibm.com>
12 */
13
14
15/* NOTE: we really do want to use the kernel headers here */
16#define __EXPORTED_HEADERS__
17
18#include <stdio.h>
19#include <stdlib.h>
20#include <unistd.h>
21#include <string.h>
22#include <linux/kconfig.h>
23
24static void usage(char *name)
25{
26 printf(format: "usage: %s [-m] policy_file context_file\n", name);
27 exit(status: 1);
28}
29
30/* Class/perm mapping support */
31struct security_class_mapping {
32 const char *name;
33 const char *perms[sizeof(unsigned) * 8 + 1];
34};
35
36#include "classmap.h"
37#include "initial_sid_to_string.h"
38#include "policycap_names.h"
39
40#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
41
42int main(int argc, char *argv[])
43{
44 int i, j, mls = 0;
45 int initial_sid_to_string_len;
46 char **arg, *polout, *ctxout;
47
48 FILE *fout;
49
50 if (argc < 3)
51 usage(name: argv[0]);
52 arg = argv+1;
53 if (argc==4 && strcmp(s1: argv[1], s2: "-m") == 0) {
54 mls = 1;
55 arg++;
56 }
57 polout = *arg++;
58 ctxout = *arg;
59
60 fout = fopen(filename: polout, modes: "w");
61 if (!fout) {
62 printf(format: "Could not open %s for writing\n", polout);
63 usage(name: argv[0]);
64 }
65
66 /* print out the classes */
67 for (i = 0; secclass_map[i].name; i++)
68 fprintf(stream: fout, format: "class %s\n", secclass_map[i].name);
69 fprintf(stream: fout, format: "\n");
70
71 initial_sid_to_string_len = sizeof(initial_sid_to_string) / sizeof (char *);
72 /* print out the sids */
73 for (i = 1; i < initial_sid_to_string_len; i++) {
74 const char *name = initial_sid_to_string[i];
75
76 if (name)
77 fprintf(stream: fout, format: "sid %s\n", name);
78 else
79 fprintf(stream: fout, format: "sid unused%d\n", i);
80 }
81 fprintf(stream: fout, format: "\n");
82
83 /* print out the class permissions */
84 for (i = 0; secclass_map[i].name; i++) {
85 const struct security_class_mapping *map = &secclass_map[i];
86 fprintf(stream: fout, format: "class %s\n", map->name);
87 fprintf(stream: fout, format: "{\n");
88 for (j = 0; map->perms[j]; j++)
89 fprintf(stream: fout, format: "\t%s\n", map->perms[j]);
90 fprintf(stream: fout, format: "}\n\n");
91 }
92 fprintf(stream: fout, format: "\n");
93
94 /* print out mls declarations and constraints */
95 if (mls) {
96 fprintf(stream: fout, format: "sensitivity s0;\n");
97 fprintf(stream: fout, format: "sensitivity s1;\n");
98 fprintf(stream: fout, format: "dominance { s0 s1 }\n");
99 fprintf(stream: fout, format: "category c0;\n");
100 fprintf(stream: fout, format: "category c1;\n");
101 fprintf(stream: fout, format: "level s0:c0.c1;\n");
102 fprintf(stream: fout, format: "level s1:c0.c1;\n");
103#define SYSTEMLOW "s0"
104#define SYSTEMHIGH "s1:c0.c1"
105 for (i = 0; secclass_map[i].name; i++) {
106 const struct security_class_mapping *map = &secclass_map[i];
107
108 fprintf(stream: fout, format: "mlsconstrain %s {\n", map->name);
109 for (j = 0; map->perms[j]; j++)
110 fprintf(stream: fout, format: "\t%s\n", map->perms[j]);
111 /*
112 * This requires all subjects and objects to be
113 * single-level (l2 eq h2), and that the subject
114 * level dominate the object level (h1 dom h2)
115 * in order to have any permissions to it.
116 */
117 fprintf(stream: fout, format: "} (l2 eq h2 and h1 dom h2);\n\n");
118 }
119 }
120
121 /* enable all policy capabilities */
122 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
123 fprintf(stream: fout, format: "policycap %s;\n", selinux_policycap_names[i]);
124
125 /* types, roles, and allows */
126 fprintf(stream: fout, format: "type base_t;\n");
127 fprintf(stream: fout, format: "role base_r;\n");
128 fprintf(stream: fout, format: "role base_r types { base_t };\n");
129 for (i = 0; secclass_map[i].name; i++)
130 fprintf(stream: fout, format: "allow base_t base_t:%s *;\n",
131 secclass_map[i].name);
132 fprintf(stream: fout, format: "user user_u roles { base_r }");
133 if (mls)
134 fprintf(stream: fout, format: " level %s range %s - %s", SYSTEMLOW,
135 SYSTEMLOW, SYSTEMHIGH);
136 fprintf(stream: fout, format: ";\n");
137
138#define SUBJUSERROLETYPE "user_u:base_r:base_t"
139#define OBJUSERROLETYPE "user_u:object_r:base_t"
140
141 /* default sids */
142 for (i = 1; i < initial_sid_to_string_len; i++) {
143 const char *name = initial_sid_to_string[i];
144
145 if (name)
146 fprintf(stream: fout, format: "sid %s ", name);
147 else
148 fprintf(stream: fout, format: "sid unused%d\n", i);
149 fprintf(stream: fout, SUBJUSERROLETYPE "%s\n",
150 mls ? ":" SYSTEMLOW : "");
151 }
152 fprintf(stream: fout, format: "\n");
153
154#define FS_USE(behavior, fstype) \
155 fprintf(fout, "fs_use_%s %s " OBJUSERROLETYPE "%s;\n", \
156 behavior, fstype, mls ? ":" SYSTEMLOW : "")
157
158 /*
159 * Filesystems whose inode labels can be fetched via getxattr.
160 */
161#ifdef CONFIG_EXT2_FS_SECURITY
162 FS_USE("xattr", "ext2");
163#endif
164#ifdef CONFIG_EXT4_FS_SECURITY
165#ifdef CONFIG_EXT4_USE_FOR_EXT2
166 FS_USE("xattr", "ext2");
167#endif
168 FS_USE("xattr", "ext3");
169 FS_USE("xattr", "ext4");
170#endif
171#ifdef CONFIG_JFS_SECURITY
172 FS_USE("xattr", "jfs");
173#endif
174#ifdef CONFIG_REISERFS_FS_SECURITY
175 FS_USE("xattr", "reiserfs");
176#endif
177#ifdef CONFIG_JFFS2_FS_SECURITY
178 FS_USE("xattr", "jffs2");
179#endif
180#ifdef CONFIG_XFS_FS
181 FS_USE("xattr", "xfs");
182#endif
183#ifdef CONFIG_GFS2_FS
184 FS_USE("xattr", "gfs2");
185#endif
186#ifdef CONFIG_BTRFS_FS
187 FS_USE("xattr", "btrfs");
188#endif
189#ifdef CONFIG_F2FS_FS_SECURITY
190 FS_USE("xattr", "f2fs");
191#endif
192#ifdef CONFIG_OCFS2_FS
193 FS_USE("xattr", "ocsfs2");
194#endif
195#ifdef CONFIG_OVERLAY_FS
196 FS_USE("xattr", "overlay");
197#endif
198#ifdef CONFIG_SQUASHFS_XATTR
199 FS_USE("xattr", "squashfs");
200#endif
201
202 /*
203 * Filesystems whose inodes are labeled from allocating task.
204 */
205 FS_USE("task", "pipefs");
206 FS_USE("task", "sockfs");
207
208 /*
209 * Filesystems whose inode labels are computed from both
210 * the allocating task and the superblock label.
211 */
212#ifdef CONFIG_UNIX98_PTYS
213 FS_USE("trans", "devpts");
214#endif
215#ifdef CONFIG_HUGETLBFS
216 FS_USE("trans", "hugetlbfs");
217#endif
218#ifdef CONFIG_TMPFS
219 FS_USE("trans", "tmpfs");
220#endif
221#ifdef CONFIG_DEVTMPFS
222 FS_USE("trans", "devtmpfs");
223#endif
224#ifdef CONFIG_POSIX_MQUEUE
225 FS_USE("trans", "mqueue");
226#endif
227
228#define GENFSCON(fstype, prefix) \
229 fprintf(fout, "genfscon %s %s " OBJUSERROLETYPE "%s\n", \
230 fstype, prefix, mls ? ":" SYSTEMLOW : "")
231
232 /*
233 * Filesystems whose inodes are labeled from path prefix match
234 * relative to the filesystem root. Depending on the filesystem,
235 * only a single label for all inodes may be supported. Here
236 * we list the filesystem types for which per-file labeling is
237 * supported using genfscon; any other filesystem type can also
238 * be added by only with a single entry for all of its inodes.
239 */
240#ifdef CONFIG_PROC_FS
241 GENFSCON("proc", "/");
242#endif
243#ifdef CONFIG_SECURITY_SELINUX
244 GENFSCON("selinuxfs", "/");
245#endif
246#ifdef CONFIG_SYSFS
247 GENFSCON("sysfs", "/");
248#endif
249#ifdef CONFIG_DEBUG_FS
250 GENFSCON("debugfs", "/");
251#endif
252#ifdef CONFIG_TRACING
253 GENFSCON("tracefs", "/");
254#endif
255#ifdef CONFIG_PSTORE
256 GENFSCON("pstore", "/");
257#endif
258 GENFSCON("cgroup", "/");
259 GENFSCON("cgroup2", "/");
260
261 fclose(stream: fout);
262
263 fout = fopen(filename: ctxout, modes: "w");
264 if (!fout) {
265 printf(format: "Wrote policy, but cannot open %s for writing\n", ctxout);
266 usage(name: argv[0]);
267 }
268 fprintf(stream: fout, format: "/ " OBJUSERROLETYPE "%s\n", mls ? ":" SYSTEMLOW : "");
269 fprintf(stream: fout, format: "/.* " OBJUSERROLETYPE "%s\n", mls ? ":" SYSTEMLOW : "");
270 fclose(stream: fout);
271
272 return 0;
273}
274

source code of linux/scripts/selinux/mdp/mdp.c