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

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