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firmload.c revision 1.6 
      1 /*	$NetBSD: firmload.c,v 1.6 2006/11/16 01:32:45 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe.
      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  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the NetBSD
     21  *	Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 __KERNEL_RCSID(0, "$NetBSD: firmload.c,v 1.6 2006/11/16 01:32:45 christos Exp $");
     41 
     42 /*
     43  * The firmload API provides an interface for device drivers to access
     44  * firmware images that must be loaded onto their devices.
     45  */
     46 
     47 #include <sys/param.h>
     48 #include <sys/fcntl.h>
     49 #include <sys/malloc.h>
     50 #include <sys/namei.h>
     51 #include <sys/systm.h>
     52 #include <sys/sysctl.h>
     53 #include <sys/vnode.h>
     54 #include <sys/kauth.h>
     55 
     56 #include <dev/firmload.h>
     57 
     58 static MALLOC_DEFINE(M_DEVFIRM, "devfirm", "device firmware buffers");
     59 
     60 struct firmware_handle {
     61 	struct vnode	*fh_vp;
     62 	off_t		 fh_size;
     63 };
     64 
     65 static firmware_handle_t
     66 firmware_handle_alloc(void)
     67 {
     68 
     69 	return (malloc(sizeof(struct firmware_handle), M_DEVFIRM, M_WAITOK));
     70 }
     71 
     72 static void
     73 firmware_handle_free(firmware_handle_t fh)
     74 {
     75 
     76 	free(fh, M_DEVFIRM);
     77 }
     78 
     79 #if !defined(FIRMWARE_PATHS)
     80 #define	FIRMWARE_PATHS		\
     81 	"/libdata/firmware:/usr/libdata/firmware:/usr/pkg/libdata/firmware:/usr/pkg/libdata"
     82 #endif
     83 
     84 static char firmware_paths[PATH_MAX+1] = FIRMWARE_PATHS;
     85 
     86 static int
     87 sysctl_hw_firmware_path(SYSCTLFN_ARGS)
     88 {
     89 	int error, i;
     90 	char newpath[PATH_MAX+1];
     91 	struct sysctlnode node;
     92 	char expected_char;
     93 
     94 	node = *rnode;
     95 	node.sysctl_data = &newpath[0];
     96 	memcpy(node.sysctl_data, rnode->sysctl_data, PATH_MAX+1);
     97 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
     98 	if (error || newp == NULL)
     99 		return (error);
    100 
    101 	/*
    102 	 * Make sure that all of the paths in the new path list are
    103 	 * absolute.
    104 	 *
    105 	 * When sysctl_lookup() deals with a string, it's guaranteed
    106 	 * to come back nul-terminated.
    107 	 */
    108 	expected_char = '/';
    109 	for (i = 0; i < PATH_MAX+1; i++) {
    110 		if (expected_char != 0 && newpath[i] != expected_char)
    111 		    	return (EINVAL);
    112 		if (newpath[i] == '\0')
    113 			break;
    114 		else if (newpath[i] == ':')
    115 			expected_char = '/';
    116 		else
    117 			expected_char = 0;
    118 	}
    119 
    120 	memcpy(rnode->sysctl_data, node.sysctl_data, PATH_MAX+1);
    121 
    122 	return (0);
    123 }
    124 
    125 SYSCTL_SETUP_PROTO(sysctl_hw_firmware_setup);
    126 
    127 SYSCTL_SETUP(sysctl_hw_firmware_setup, "sysctl hw.firmware subtree setup")
    128 {
    129 	const struct sysctlnode *firmware_node;
    130 
    131 	if (sysctl_createv(clog, 0, NULL, NULL,
    132 	    CTLFLAG_PERMANENT,
    133 	    CTLTYPE_NODE, "hw", NULL,
    134 	    NULL, 0, NULL, 0,
    135 	    CTL_HW, CTL_EOL) != 0)
    136 	    	return;
    137 
    138 	if (sysctl_createv(clog, 0, NULL, &firmware_node,
    139 	    CTLFLAG_PERMANENT,
    140 	    CTLTYPE_NODE, "firmware", NULL,
    141 	    NULL, 0, NULL, 0,
    142 	    CTL_HW, CTL_CREATE, CTL_EOL) != 0)
    143 	    	return;
    144 
    145 	sysctl_createv(clog, 0, NULL, NULL,
    146 	    CTLFLAG_READWRITE,
    147 	    CTLTYPE_STRING, "path",
    148 	    SYSCTL_DESCR("Device firmware loading path list"),
    149 	    sysctl_hw_firmware_path, 0, firmware_paths, PATH_MAX+1,
    150 	    CTL_HW, firmware_node->sysctl_num, CTL_CREATE, CTL_EOL);
    151 }
    152 
    153 static char *
    154 firmware_path_next(const char *drvname, const char *imgname, char *pnbuf,
    155     char **prefixp)
    156 {
    157 	char *prefix = *prefixp;
    158 	size_t maxprefix, i;
    159 
    160 	if (prefix == NULL		/* terminated early */
    161 	    || *prefix == '\0'		/* no more left */
    162 	    || *prefix != '/') {	/* not absolute */
    163 		*prefixp = NULL;
    164 	    	return (NULL);
    165 	}
    166 
    167 	/*
    168 	 * Compute the max path prefix based on the length of the provided
    169 	 * names.
    170 	 */
    171 	maxprefix = MAXPATHLEN -
    172 		(1 /* / */
    173 		 + strlen(drvname)
    174 		 + 1 /* / */
    175 		 + strlen(imgname)
    176 		 + 1 /* terminating NUL */);
    177 
    178 	/* Check for underflow (size_t is unsigned). */
    179 	if (maxprefix > MAXPATHLEN) {
    180 		*prefixp = NULL;
    181 		return (NULL);
    182 	}
    183 
    184 	for (i = 0; i < maxprefix; i++) {
    185 		if (*prefix == ':' || *prefix == '\0')
    186 			break;
    187 		pnbuf[i] = *prefix++;
    188 	}
    189 
    190 	if (*prefix != ':' && *prefix != '\0') {
    191 		/* Path prefix was too long. */
    192 		*prefixp = NULL;
    193 		return (NULL);
    194 	}
    195 
    196 	if (*prefix != '\0')
    197 		prefix++;
    198 	*prefixp = prefix;
    199 
    200 	/*
    201 	 * This sprintf() is safe because of the maxprefix calculation
    202 	 * performed above.
    203 	 */
    204 	sprintf(&pnbuf[i], "/%s/%s", drvname, imgname);
    205 
    206 	return (pnbuf);
    207 }
    208 
    209 static char *
    210 firmware_path_first(const char *drvname, const char *imgname, char *pnbuf,
    211     char **prefixp)
    212 {
    213 
    214 	*prefixp = firmware_paths;
    215 	return (firmware_path_next(drvname, imgname, pnbuf, prefixp));
    216 }
    217 
    218 /*
    219  * firmware_open:
    220  *
    221  *	Open a firmware image and return its handle.
    222  */
    223 int
    224 firmware_open(const char *drvname, const char *imgname, firmware_handle_t *fhp)
    225 {
    226 	struct nameidata nd;
    227 	struct vattr va;
    228 	char *pnbuf, *path, *prefix;
    229 	firmware_handle_t fh;
    230 	struct vnode *vp;
    231 	int error;
    232 
    233 	if (drvname == NULL || imgname == NULL)
    234 		return (EINVAL);
    235 
    236 	pnbuf = PNBUF_GET();
    237 	KASSERT(pnbuf != NULL);
    238 
    239 	fh = firmware_handle_alloc();
    240 	KASSERT(fh != NULL);
    241 
    242 	error = 0;
    243 	for (path = firmware_path_first(drvname, imgname, pnbuf, &prefix);
    244 	     path != NULL;
    245 	     path = firmware_path_next(drvname, imgname, pnbuf, &prefix)) {
    246 		NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, path, curlwp);
    247 		error = vn_open(&nd, FREAD, 0);
    248 		if (error == ENOENT)
    249 			continue;
    250 		break;
    251 	}
    252 
    253 	PNBUF_PUT(pnbuf);
    254 	if (error) {
    255 		firmware_handle_free(fh);
    256 		return (error);
    257 	}
    258 
    259 	vp = nd.ni_vp;
    260 
    261 	error = VOP_GETATTR(vp, &va, kauth_cred_get(), curlwp);
    262 	if (error) {
    263 		VOP_UNLOCK(vp, 0);
    264 		(void)vn_close(vp, FREAD, kauth_cred_get(), curlwp);
    265 		firmware_handle_free(fh);
    266 		return (error);
    267 	}
    268 
    269 	if (va.va_type != VREG) {
    270 		VOP_UNLOCK(vp, 0);
    271 		(void)vn_close(vp, FREAD, kauth_cred_get(), curlwp);
    272 		firmware_handle_free(fh);
    273 		return (EINVAL);
    274 	}
    275 
    276 	/* XXX Mark as busy text file. */
    277 
    278 	fh->fh_vp = vp;
    279 	fh->fh_size = va.va_size;
    280 
    281 	VOP_UNLOCK(vp, 0);
    282 
    283 	*fhp = fh;
    284 	return (0);
    285 }
    286 
    287 /*
    288  * firmware_close:
    289  *
    290  *	Close a firmware image.
    291  */
    292 int
    293 firmware_close(firmware_handle_t fh)
    294 {
    295 	int error;
    296 
    297 	error = vn_close(fh->fh_vp, FREAD, kauth_cred_get(), curlwp);
    298 	firmware_handle_free(fh);
    299 	return (error);
    300 }
    301 
    302 /*
    303  * firmware_get_size:
    304  *
    305  *	Return the total size of a firmware image.
    306  */
    307 off_t
    308 firmware_get_size(firmware_handle_t fh)
    309 {
    310 
    311 	return (fh->fh_size);
    312 }
    313 
    314 /*
    315  * firmware_read:
    316  *
    317  *	Read data from a firmware image at the specified offset into
    318  *	the provided buffer.
    319  */
    320 int
    321 firmware_read(firmware_handle_t fh, off_t offset, void *buf, size_t len)
    322 {
    323 
    324 	return (vn_rdwr(UIO_READ, fh->fh_vp, buf, len, offset,
    325 			UIO_SYSSPACE, 0, kauth_cred_get(), NULL, curlwp));
    326 }
    327 
    328 /*
    329  * firmware_malloc:
    330  *
    331  *	Allocate a firmware buffer of the specified size.
    332  *
    333  *	NOTE: This routine may block.
    334  */
    335 void *
    336 firmware_malloc(size_t size)
    337 {
    338 
    339 	return (malloc(size, M_DEVFIRM, M_WAITOK));
    340 }
    341 
    342 /*
    343  * firmware_free:
    344  *
    345  *	Free a previously allocated firmware buffer.
    346  */
    347 /*ARGSUSED*/
    348 void
    349 firmware_free(void *v, size_t size)
    350 {
    351 
    352 	free(v, M_DEVFIRM);
    353 }
    354