1 /* $NetBSD: kern_module_vfs.c,v 1.18 2021/06/29 22:40:53 dholland Exp $ */
2
3 /*-
4 * Copyright (c) 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software developed for The NetBSD Foundation
8 * by Andrew Doran.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * Kernel module file system interaction.
34 */
35
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: kern_module_vfs.c,v 1.18 2021/06/29 22:40:53 dholland Exp $");
38
39 #define _MODULE_INTERNAL
40 #include <sys/param.h>
41 #include <sys/fcntl.h>
42 #include <sys/kmem.h>
43 #include <sys/kobj.h>
44 #include <sys/module.h>
45 #include <sys/namei.h>
46 #include <sys/pool.h>
47 #include <sys/stat.h>
48 #include <sys/vnode.h>
49
50 #include <prop/proplib.h>
51
52 static int module_load_plist_vfs(const char *, const bool,
53 prop_dictionary_t *);
54
55 void
module_load_vfs_init(void)56 module_load_vfs_init(void)
57 {
58 module_load_vfs_vec = module_load_vfs;
59 aprint_normal("kern.module.path=%s\n", module_base);
60 }
61
62 int
module_load_vfs(const char * name,int flags,bool autoload,module_t * mod,prop_dictionary_t * filedictp)63 module_load_vfs(const char *name, int flags, bool autoload,
64 module_t *mod, prop_dictionary_t *filedictp)
65 {
66 char *path;
67 bool nochroot;
68 int error;
69 prop_bool_t noload;
70 prop_dictionary_t moduledict;
71
72 nochroot = false;
73 error = 0;
74 path = NULL;
75 moduledict = NULL;
76 if (filedictp)
77 *filedictp = NULL;
78 path = PNBUF_GET();
79
80 if (!autoload) {
81 if (strchr(name, '/') != NULL) {
82 nochroot = false;
83 snprintf(path, MAXPATHLEN, "%s", name);
84 module_print("Loading module from %s", path);
85 error = kobj_load_vfs(&mod->mod_kobj, path, nochroot);
86 } else
87 error = ENOENT;
88 }
89 if (autoload || (error == ENOENT)) {
90 if (strchr(name, '/') == NULL) {
91 nochroot = true;
92 snprintf(path, MAXPATHLEN, "%s/%s/%s.kmod",
93 module_base, name, name);
94 module_print("Loading module from %s", path);
95 error = kobj_load_vfs(&mod->mod_kobj, path, nochroot);
96 } else
97 error = ENOENT;
98 }
99 if (error != 0) {
100 PNBUF_PUT(path);
101 module_print("Cannot %sload kernel object `%s'"
102 " error=%d", autoload ? "auto" : "", name, error);
103 return error;
104 }
105
106 /*
107 * Load and process <module>.plist if it exists.
108 */
109 if ((!ISSET(flags, MODCTL_NO_PROP) && filedictp) || autoload) {
110 error = module_load_plist_vfs(path, nochroot, &moduledict);
111 if (error != 0) {
112 module_print("plist load returned error %d for `%s'",
113 error, path);
114 if (error != ENOENT)
115 goto fail;
116 } else if (autoload) {
117 noload = prop_dictionary_get(moduledict, "noautoload");
118 if (noload != NULL && prop_bool_true(noload)) {
119 module_error("autoloading is disallowed for %s",
120 path);
121 prop_object_release(moduledict);
122 error = EPERM;
123 goto fail;
124 }
125 }
126 if (error == 0) { /* can get here if error == ENOENT */
127 if (!ISSET(flags, MODCTL_NO_PROP) && filedictp)
128 *filedictp = moduledict;
129 else
130 prop_object_release(moduledict);
131 }
132 }
133
134 PNBUF_PUT(path);
135 return 0;
136
137 fail:
138 kobj_unload(mod->mod_kobj);
139 PNBUF_PUT(path);
140 return error;
141 }
142
143 /*
144 * module_load_plist_vfs:
145 *
146 * Load a plist located in the file system into memory.
147 */
148 static int
module_load_plist_vfs(const char * modpath,const bool nochroot,prop_dictionary_t * filedictp)149 module_load_plist_vfs(const char *modpath, const bool nochroot,
150 prop_dictionary_t *filedictp)
151 {
152 struct pathbuf *pb;
153 struct vnode *vp;
154 struct stat sb;
155 void *base;
156 char *proppath;
157 const size_t plistsize = 8192;
158 size_t resid;
159 int error, pathlen;
160
161 KASSERT(filedictp != NULL);
162 base = NULL;
163
164 proppath = PNBUF_GET();
165 strlcpy(proppath, modpath, MAXPATHLEN);
166 pathlen = strlen(proppath);
167 if ((pathlen >= 6) && (strcmp(&proppath[pathlen - 5], ".kmod") == 0)) {
168 strcpy(&proppath[pathlen - 5], ".plist");
169 } else if (pathlen < MAXPATHLEN - 6) {
170 strcat(proppath, ".plist");
171 } else {
172 error = ENOENT;
173 goto out1;
174 }
175
176 /* XXX this makes an unnecessary extra copy of the path */
177 pb = pathbuf_create(proppath);
178 if (pb == NULL) {
179 error = ENOMEM;
180 goto out1;
181 }
182 module_print("Loading plist from %s", proppath);
183
184 error = vn_open(NULL, pb, (nochroot ? NOCHROOT : 0), FREAD, 0,
185 &vp, NULL, NULL);
186 if (error != 0) {
187 goto out2;
188 }
189
190 error = vn_stat(vp, &sb);
191 if (error != 0) {
192 goto out3;
193 }
194 if (sb.st_size >= (plistsize - 1)) { /* leave space for term \0 */
195 error = EFBIG;
196 goto out3;
197 }
198
199 base = kmem_alloc(plistsize, KM_SLEEP);
200 error = vn_rdwr(UIO_READ, vp, base, sb.st_size, 0,
201 UIO_SYSSPACE, IO_NODELOCKED, curlwp->l_cred, &resid, curlwp);
202 *((uint8_t *)base + sb.st_size) = '\0';
203 if (error == 0 && resid != 0) {
204 error = EFBIG;
205 }
206 if (error != 0) {
207 kmem_free(base, plistsize);
208 base = NULL;
209 goto out3;
210 }
211
212 *filedictp = prop_dictionary_internalize(base);
213 if (*filedictp == NULL) {
214 error = EINVAL;
215 }
216 kmem_free(base, plistsize);
217 base = NULL;
218 KASSERT(error == 0);
219
220 out3:
221 VOP_UNLOCK(vp);
222 vn_close(vp, FREAD, kauth_cred_get());
223
224 out2:
225 pathbuf_destroy(pb);
226
227 out1:
228 PNBUF_PUT(proppath);
229 return error;
230 }
231