1 /* $NetBSD: veriexec.c,v 1.3 2022/02/12 02:40:48 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2005, 2006 Elad Efrat <elad@NetBSD.org>
5 * Copyright (c) 2005, 2006 Brett Lymn <blymn@NetBSD.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. The name of the authors may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: veriexec.c,v 1.3 2022/02/12 02:40:48 riastradh Exp $");
33
34 #include <sys/param.h>
35 #include <sys/errno.h>
36 #include <sys/conf.h>
37 #include <sys/vnode.h>
38 #include <sys/fcntl.h>
39 #include <sys/namei.h>
40 #include <sys/verified_exec.h>
41 #include <sys/kauth.h>
42 #include <sys/syslog.h>
43 #include <sys/proc.h>
44
45 #include <sys/ioctl.h>
46 #include <sys/device_if.h>
47
48 #include <prop/proplib.h>
49
50 void veriexecattach(device_t, device_t, void *);
51 static dev_type_open(veriexecopen);
52 static dev_type_close(veriexecclose);
53 static dev_type_ioctl(veriexecioctl);
54
55 const struct cdevsw veriexec_cdevsw = {
56 .d_open = veriexecopen,
57 .d_close = veriexecclose,
58 .d_read = noread,
59 .d_write = nowrite,
60 .d_ioctl = veriexecioctl,
61 .d_stop = nostop,
62 .d_tty = notty,
63 .d_poll = nopoll,
64 .d_mmap = nommap,
65 .d_discard = nodiscard,
66 .d_kqfilter = nokqfilter,
67 .d_flag = D_OTHER,
68 };
69
70 /* count of number of times device is open (we really only allow one open) */
71 static unsigned int veriexec_dev_usage = 0;
72
73 void
veriexecattach(device_t parent,device_t self,void * aux)74 veriexecattach(device_t parent, device_t self, void *aux)
75 {
76 veriexec_dev_usage = 0;
77 }
78
79 static int
veriexecopen(dev_t dev,int flags,int fmt,struct lwp * l)80 veriexecopen(dev_t dev, int flags, int fmt, struct lwp *l)
81 {
82 if (kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_VERIEXEC,
83 KAUTH_REQ_SYSTEM_VERIEXEC_ACCESS, NULL, NULL, NULL))
84 return (EPERM);
85
86 if (veriexec_dev_usage > 0)
87 return(EBUSY);
88
89 veriexec_dev_usage++;
90 return (0);
91 }
92
93 static int
veriexecclose(dev_t dev,int flags,int fmt,struct lwp * l)94 veriexecclose(dev_t dev, int flags, int fmt, struct lwp *l)
95 {
96 if (veriexec_dev_usage > 0)
97 veriexec_dev_usage--;
98 return (0);
99 }
100
101 static int
veriexec_delete(prop_dictionary_t dict,struct lwp * l)102 veriexec_delete(prop_dictionary_t dict, struct lwp *l)
103 {
104 struct vnode *vp;
105 const char *file;
106 int error;
107
108 if (!prop_dictionary_get_string(dict, "file", &file))
109 return (EINVAL);
110
111 error = namei_simple_kernel(file, NSM_FOLLOW_NOEMULROOT, &vp);
112 if (error)
113 return (error);
114
115 /* XXX this should be done differently... */
116 if (vp->v_type == VREG)
117 error = veriexec_file_delete(l, vp);
118 else if (vp->v_type == VDIR)
119 error = veriexec_table_delete(l, vp->v_mount);
120
121 vrele(vp);
122
123 return (error);
124 }
125
126 static int
veriexec_query(prop_dictionary_t dict,prop_dictionary_t rdict,struct lwp * l)127 veriexec_query(prop_dictionary_t dict, prop_dictionary_t rdict, struct lwp *l)
128 {
129 struct vnode *vp;
130 const char *file;
131 int error;
132
133 if (!prop_dictionary_get_string(dict, "file", &file))
134 return (EINVAL);
135
136 error = namei_simple_kernel(file, NSM_FOLLOW_NOEMULROOT, &vp);
137 if (error)
138 return (error);
139
140 error = veriexec_convert(vp, rdict);
141
142 vrele(vp);
143
144 return (error);
145 }
146
147 int
veriexecioctl(dev_t dev,u_long cmd,void * data,int flags,struct lwp * l)148 veriexecioctl(dev_t dev, u_long cmd, void *data, int flags, struct lwp *l)
149 {
150 struct plistref *plistref;
151 prop_dictionary_t dict;
152 int error = 0;
153
154 switch (cmd) {
155 case VERIEXEC_TABLESIZE:
156 case VERIEXEC_LOAD:
157 case VERIEXEC_DELETE:
158 case VERIEXEC_FLUSH:
159 if (!(flags & FWRITE))
160 return (EPERM);
161
162 error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_VERIEXEC,
163 KAUTH_REQ_SYSTEM_VERIEXEC_MODIFY, KAUTH_ARG(cmd), NULL,
164 NULL);
165 if (error)
166 return error;
167
168 break;
169
170 case VERIEXEC_QUERY:
171 case VERIEXEC_DUMP:
172 if (!(flags & FREAD))
173 return (EPERM);
174
175 break;
176
177 default:
178 /* Invalid operation. */
179 return (ENODEV);
180 }
181
182 plistref = (struct plistref *)data;
183
184 switch (cmd) {
185 case VERIEXEC_TABLESIZE:
186 /* Do nothing. Kept for binary compatibility. */
187 break;
188
189 case VERIEXEC_LOAD:
190 error = prop_dictionary_copyin_ioctl(plistref, cmd, &dict);
191 if (error)
192 break;
193
194 error = veriexec_file_add(l, dict);
195 prop_object_release(dict);
196 break;
197
198 case VERIEXEC_DELETE:
199 error = prop_dictionary_copyin_ioctl(plistref, cmd, &dict);
200 if (error)
201 break;
202
203 error = veriexec_delete(dict, l);
204 prop_object_release(dict);
205 break;
206
207 case VERIEXEC_QUERY: {
208 prop_dictionary_t rdict;
209
210 error = prop_dictionary_copyin_ioctl(plistref, cmd, &dict);
211 if (error)
212 return (error);
213
214 rdict = prop_dictionary_create();
215 if (rdict == NULL) {
216 prop_object_release(dict);
217 error = ENOMEM;
218 break;
219 }
220
221 error = veriexec_query(dict, rdict, l);
222 if (error == 0) {
223 error = prop_dictionary_copyout_ioctl(plistref, cmd,
224 rdict);
225 }
226
227 prop_object_release(rdict);
228 prop_object_release(dict);
229
230 break;
231 }
232
233 case VERIEXEC_DUMP: {
234 prop_array_t rarray;
235
236 rarray = prop_array_create();
237 if (rarray == NULL) {
238 error = ENOMEM;
239 break;
240 }
241
242 error = veriexec_dump(l, rarray);
243 if (error == 0) {
244 error = prop_array_copyout_ioctl(plistref, cmd,
245 rarray);
246 }
247
248 prop_object_release(rarray);
249
250 break;
251 }
252
253 case VERIEXEC_FLUSH:
254 error = veriexec_flush(l);
255 break;
256
257 default:
258 /* Invalid operation. */
259 error = ENODEV;
260 break;
261 }
262
263 return (error);
264 }
265
266