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      1 /*	$NetBSD: kern_module_vfs.c,v 1.20 2026/01/04 01:36:11 riastradh 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 1.20 2026/01/04 01:36:11 riastradh Exp $");
     38 
     39 #define _MODULE_INTERNAL
     40 
     41 #include <sys/param.h>
     42 
     43 #include <sys/fcntl.h>
     44 #include <sys/kmem.h>
     45 #include <sys/kobj.h>
     46 #include <sys/module.h>
     47 #include <sys/namei.h>
     48 #include <sys/pool.h>
     49 #include <sys/stat.h>
     50 #include <sys/sdt.h>
     51 #include <sys/vnode.h>
     52 
     53 #include <prop/proplib.h>
     54 
     55 static int	module_load_plist_vfs(const char *, const bool,
     56 				      prop_dictionary_t *);
     57 
     58 void
     59 module_load_vfs_init(void)
     60 {
     61 	module_load_vfs_vec = module_load_vfs;
     62 	aprint_normal("kern.module.path=%s\n", module_base);
     63 }
     64 
     65 int
     66 module_load_vfs(const char *name, int flags, bool autoload,
     67 	module_t *mod, prop_dictionary_t *filedictp)
     68 {
     69 	char *path;
     70 	bool nochroot;
     71 	int error;
     72 	prop_bool_t noload;
     73 	prop_dictionary_t moduledict;
     74 
     75 	nochroot = false;
     76 	error = 0;
     77 	path = NULL;
     78 	moduledict = NULL;
     79 	if (filedictp)
     80 		*filedictp = NULL;
     81 	path = PNBUF_GET();
     82 
     83 	if (!autoload) {
     84 		if (strchr(name,  '/') != NULL) {
     85 			nochroot = false;
     86 			snprintf(path, MAXPATHLEN, "%s", name);
     87 			module_print("Loading module from %s", path);
     88 			error = kobj_load_vfs(&mod->mod_kobj, path, nochroot);
     89 		} else
     90 			error = SET_ERROR(ENOENT);
     91 	}
     92 	if (autoload || (error == ENOENT)) {
     93 		if (strchr(name, '/') == NULL) {
     94 			nochroot = true;
     95 			snprintf(path, MAXPATHLEN, "%s/%s/%s.kmod",
     96 			    module_base, name, name);
     97 			module_print("Loading module from %s", path);
     98 			error = kobj_load_vfs(&mod->mod_kobj, path, nochroot);
     99 		} else
    100 			error = SET_ERROR(ENOENT);
    101 	}
    102 	if (error != 0) {
    103 		PNBUF_PUT(path);
    104 		module_print("Cannot %sload kernel object `%s'"
    105 		    " error=%d", autoload ? "auto" : "", name, error);
    106 		return error;
    107 	}
    108 
    109 	/*
    110 	 * Load and process <module>.plist if it exists.
    111 	 */
    112 	if ((!ISSET(flags, MODCTL_NO_PROP) && filedictp) || autoload) {
    113 		error = module_load_plist_vfs(path, nochroot, &moduledict);
    114 		if (error != 0) {
    115 			module_print("plist load returned error %d for `%s'",
    116 			    error, path);
    117 			if (error != ENOENT)
    118 				goto fail;
    119 		} else if (autoload) {
    120 			noload = prop_dictionary_get(moduledict, "noautoload");
    121 			if (noload != NULL && prop_bool_true(noload)) {
    122 				module_error("autoloading is disallowed for "
    123 				    "`%s'", path);
    124 				prop_object_release(moduledict);
    125 				error = SET_ERROR(EPERM);
    126 				goto fail;
    127 			}
    128 		}
    129 		if (error == 0) {	/* can get here if error == ENOENT */
    130 			if (!ISSET(flags, MODCTL_NO_PROP) && filedictp)
    131 				*filedictp = moduledict;
    132 			else
    133 				prop_object_release(moduledict);
    134 		}
    135 	}
    136 
    137 	PNBUF_PUT(path);
    138 	return 0;
    139 
    140  fail:
    141 	kobj_unload(mod->mod_kobj);
    142 	PNBUF_PUT(path);
    143 	return error;
    144 }
    145 
    146 /*
    147  * module_load_plist_vfs:
    148  *
    149  *	Load a plist located in the file system into memory.
    150  */
    151 static int
    152 module_load_plist_vfs(const char *modpath, const bool nochroot,
    153     prop_dictionary_t *filedictp)
    154 {
    155 	struct pathbuf *pb;
    156 	struct vnode *vp;
    157 	struct stat sb;
    158 	void *base;
    159 	char *proppath;
    160 	const size_t plistsize = 8192;
    161 	size_t resid;
    162 	int error, pathlen;
    163 
    164 	KASSERT(filedictp != NULL);
    165 	base = NULL;
    166 
    167 	proppath = PNBUF_GET();
    168 	strlcpy(proppath, modpath, MAXPATHLEN);
    169 	pathlen = strlen(proppath);
    170 	if ((pathlen >= 6) && (strcmp(&proppath[pathlen - 5], ".kmod") == 0)) {
    171 		strcpy(&proppath[pathlen - 5], ".plist");
    172 	} else if (pathlen < MAXPATHLEN - 6) {
    173 			strcat(proppath, ".plist");
    174 	} else {
    175 		error = SET_ERROR(ENOENT);
    176 		goto out1;
    177 	}
    178 
    179 	/* XXX this makes an unnecessary extra copy of the path */
    180 	pb = pathbuf_create(proppath);
    181 	if (pb == NULL) {
    182 		error = SET_ERROR(ENOMEM);
    183 		goto out1;
    184 	}
    185 	module_print("Loading plist from %s", proppath);
    186 
    187 	error = vn_open(NULL, pb, (nochroot ? NOCHROOT : 0), FREAD, 0,
    188 	    &vp, NULL, NULL);
    189  	if (error != 0) {
    190 	 	goto out2;
    191 	}
    192 
    193 	error = vn_stat(vp, &sb);
    194 	if (error != 0) {
    195 		goto out3;
    196 	}
    197 	if (sb.st_size >= (plistsize - 1)) {	/* leave space for term \0 */
    198 		error = SET_ERROR(EFBIG);
    199 		goto out3;
    200 	}
    201 
    202 	base = kmem_alloc(plistsize, KM_SLEEP);
    203 	error = vn_rdwr(UIO_READ, 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 = SET_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 = SET_ERROR(EINVAL);
    218 	}
    219 	kmem_free(base, plistsize);
    220 	base = NULL;
    221 	KASSERT(error == 0);
    222 
    223 out3:
    224 	VOP_UNLOCK(vp);
    225 	vn_close(vp, FREAD, kauth_cred_get());
    226 
    227 out2:
    228 	pathbuf_destroy(pb);
    229 
    230 out1:
    231 	PNBUF_PUT(proppath);
    232 	return error;
    233 }
    234