xref: /netbsd-src/sys/kern/kern_module_vfs.c (revision aad9773e38ed2370a628a6416e098f9008fc10a7)
1 /*	$NetBSD: kern_module_vfs.c,v 1.13 2014/12/02 13:00:38 pooka 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 1.13 2014/12/02 13:00:38 pooka 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
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
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 			error = kobj_load_vfs(&mod->mod_kobj, path, nochroot);
85 		} else
86 			error = ENOENT;
87 	}
88 	if (autoload || (error == ENOENT)) {
89 		if (strchr(name, '/') == NULL) {
90 			nochroot = true;
91 			snprintf(path, MAXPATHLEN, "%s/%s/%s.kmod",
92 			    module_base, name, name);
93 			error = kobj_load_vfs(&mod->mod_kobj, path, nochroot);
94 		} else
95 			error = ENOENT;
96 	}
97 	if (error != 0) {
98 		PNBUF_PUT(path);
99 		module_print("Cannot %sload kernel object `%s'"
100 		    " error=%d", autoload ? "auto" : "", name, error);
101 		return error;
102 	}
103 
104 	/*
105 	 * Load and process <module>.plist if it exists.
106 	 */
107 	if (((flags & MODCTL_NO_PROP) == 0 && filedictp) || autoload) {
108 		error = module_load_plist_vfs(path, nochroot, &moduledict);
109 		if (error != 0) {
110 			module_print("plist load returned error %d for `%s'",
111 			    error, path);
112 			if (error != ENOENT)
113 				goto fail;
114 		} else if (autoload) {
115 			noload = prop_dictionary_get(moduledict, "noautoload");
116 			if (noload != NULL && prop_bool_true(noload)) {
117 				module_error("autoloading is disallowed for %s",
118 				    path);
119 				prop_object_release(moduledict);
120 				error = EPERM;
121 				goto fail;
122 			}
123 		}
124 		if (error == 0) {	/* can get here if error == ENOENT */
125 			if ((flags & MODCTL_NO_PROP) == 0 && filedictp)
126 				*filedictp = moduledict;
127 			else
128 				prop_object_release(moduledict);
129 		}
130 	}
131 
132 	PNBUF_PUT(path);
133 	return 0;
134 
135  fail:
136 	kobj_unload(mod->mod_kobj);
137 	PNBUF_PUT(path);
138 	return error;
139 }
140 
141 /*
142  * module_load_plist_vfs:
143  *
144  *	Load a plist located in the file system into memory.
145  */
146 static int
147 module_load_plist_vfs(const char *modpath, const bool nochroot,
148     prop_dictionary_t *filedictp)
149 {
150 	struct pathbuf *pb;
151 	struct nameidata nd;
152 	struct stat sb;
153 	void *base;
154 	char *proppath;
155 	const size_t plistsize = 8192;
156 	size_t resid;
157 	int error, pathlen;
158 
159 	KASSERT(filedictp != NULL);
160 	base = NULL;
161 
162 	proppath = PNBUF_GET();
163 	strcpy(proppath, modpath);
164 	pathlen = strlen(proppath);
165 	if ((pathlen >= 6) && (strcmp(&proppath[pathlen - 5], ".kmod") == 0)) {
166 		strcpy(&proppath[pathlen - 5], ".plist");
167 	} else if (pathlen < MAXPATHLEN - 6) {
168 			strcat(proppath, ".plist");
169 	} else {
170 		error = ENOENT;
171 		goto out1;
172 	}
173 
174 	/* XXX this makes an unnecessary extra copy of the path */
175 	pb = pathbuf_create(proppath);
176 	if (pb == NULL) {
177 		error = ENOMEM;
178 		goto out1;
179 	}
180 
181 	NDINIT(&nd, LOOKUP, FOLLOW | (nochroot ? NOCHROOT : 0), pb);
182 
183 	error = vn_open(&nd, FREAD, 0);
184  	if (error != 0) {
185 	 	goto out2;
186 	}
187 
188 	error = vn_stat(nd.ni_vp, &sb);
189 	if (error != 0) {
190 		goto out3;
191 	}
192 	if (sb.st_size >= (plistsize - 1)) {	/* leave space for term \0 */
193 		error = EFBIG;
194 		goto out3;
195 	}
196 
197 	base = kmem_alloc(plistsize, KM_SLEEP);
198 	if (base == NULL) {
199 		error = ENOMEM;
200 		goto out3;
201 	}
202 
203 	error = vn_rdwr(UIO_READ, nd.ni_vp, base, sb.st_size, 0,
204 	    UIO_SYSSPACE, IO_NODELOCKED, curlwp->l_cred, &resid, curlwp);
205 	*((uint8_t *)base + sb.st_size) = '\0';
206 	if (error == 0 && resid != 0) {
207 		error = EFBIG;
208 	}
209 	if (error != 0) {
210 		kmem_free(base, plistsize);
211 		base = NULL;
212 		goto out3;
213 	}
214 
215 	*filedictp = prop_dictionary_internalize(base);
216 	if (*filedictp == NULL) {
217 		error = EINVAL;
218 	}
219 	kmem_free(base, plistsize);
220 	base = NULL;
221 	KASSERT(error == 0);
222 
223 out3:
224 	VOP_UNLOCK(nd.ni_vp);
225 	vn_close(nd.ni_vp, FREAD, kauth_cred_get());
226 
227 out2:
228 	pathbuf_destroy(pb);
229 
230 out1:
231 	PNBUF_PUT(proppath);
232 	return error;
233 }
234