xref: /netbsd-src/sys/dev/firmload.c (revision 27527e67bbdf8d9ec84fd58803048ed6d181ece2)
1 /*	$NetBSD: firmload.c,v 1.1 2006/01/17 06:08:49 thorpej 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 1.1 2006/01/17 06:08:49 thorpej 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 
55 #include <dev/firmload.h>
56 
57 static MALLOC_DEFINE(M_DEVFIRM, "devfirm", "device firmware buffers");
58 
59 struct firmware_handle {
60 	struct vnode	*fh_vp;
61 	off_t		 fh_size;
62 };
63 
64 static firmware_handle_t
65 firmware_handle_alloc(void)
66 {
67 
68 	return (malloc(sizeof(struct firmware_handle), M_DEVFIRM, M_WAITOK));
69 }
70 
71 static void
72 firmware_handle_free(firmware_handle_t fh)
73 {
74 
75 	free(fh, M_DEVFIRM);
76 }
77 
78 #if !defined(FIRMWARE_PATHS)
79 #define	FIRMWARE_PATHS		\
80 	"/libdata/firmware:/usr/libdata/firmware:/usr/pkg/libdata/firmware"
81 #endif
82 
83 static char firmware_paths[PATH_MAX+1] = FIRMWARE_PATHS;
84 
85 static int
86 sysctl_hw_firmware_path(SYSCTLFN_ARGS)
87 {
88 	int error, i;
89 	char newpath[PATH_MAX+1];
90 	struct sysctlnode node;
91 	char expected_char;
92 
93 	node = *rnode;
94 	node.sysctl_data = &newpath[0];
95 	memcpy(node.sysctl_data, rnode->sysctl_data, PATH_MAX+1);
96 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
97 	if (error || newp == NULL)
98 		return (error);
99 
100 	/*
101 	 * Make sure that all of the paths in the new path list are
102 	 * absolute.
103 	 *
104 	 * When sysctl_lookup() deals with a string, it's guaranteed
105 	 * to come back nul-terminated.
106 	 */
107 	expected_char = '/';
108 	for (i = 0; i < PATH_MAX+1; i++) {
109 		if (expected_char != 0 && newpath[i] != expected_char)
110 		    	return (EINVAL);
111 		if (newpath[i] == '\0')
112 			break;
113 		else if (newpath[i] == ':')
114 			expected_char = '/';
115 		else
116 			expected_char = 0;
117 	}
118 
119 	memcpy(rnode->sysctl_data, node.sysctl_data, PATH_MAX+1);
120 
121 	return (0);
122 }
123 
124 SYSCTL_SETUP_PROTO(sysctl_hw_firmware_setup);
125 
126 SYSCTL_SETUP(sysctl_hw_firmware_setup, "sysctl hw.firmware subtree setup")
127 {
128 	const struct sysctlnode *firmware_node;
129 
130 	if (sysctl_createv(clog, 0, NULL, NULL,
131 	    CTLFLAG_PERMANENT,
132 	    CTLTYPE_NODE, "hw", NULL,
133 	    NULL, 0, NULL, 0,
134 	    CTL_HW, CTL_EOL) != 0)
135 	    	return;
136 
137 	if (sysctl_createv(clog, 0, NULL, &firmware_node,
138 	    CTLFLAG_PERMANENT,
139 	    CTLTYPE_NODE, "firmware", NULL,
140 	    NULL, 0, NULL, 0,
141 	    CTL_HW, CTL_CREATE, CTL_EOL) != 0)
142 	    	return;
143 
144 	sysctl_createv(clog, 0, NULL, NULL,
145 	    CTLFLAG_READWRITE,
146 	    CTLTYPE_STRING, "path",
147 	    SYSCTL_DESCR("Device firmware loading path list"),
148 	    sysctl_hw_firmware_path, 0, firmware_paths, PATH_MAX+1,
149 	    CTL_HW, firmware_node->sysctl_num, CTL_CREATE, CTL_EOL);
150 }
151 
152 static char *
153 firmware_path_next(const char *drvname, const char *imgname, char *pnbuf,
154     char **prefixp)
155 {
156 	char *prefix = *prefixp;
157 	size_t maxprefix, i;
158 
159 	if (prefix == NULL		/* terminated early */
160 	    || *prefix == '\0'		/* no more left */
161 	    || *prefix != '/') {	/* not absolute */
162 		*prefixp = NULL;
163 	    	return (NULL);
164 	}
165 
166 	/*
167 	 * Compute the max path prefix based on the length of the provided
168 	 * names.
169 	 */
170 	maxprefix = MAXPATHLEN -
171 		(1 /* / */
172 		 + strlen(drvname)
173 		 + 1 /* / */
174 		 + strlen(imgname)
175 		 + 1 /* terminating NUL */);
176 
177 	/* Check for underflow (size_t is unsigned). */
178 	if (maxprefix > MAXPATHLEN) {
179 		*prefixp = NULL;
180 		return (NULL);
181 	}
182 
183 	for (i = 0; i < maxprefix; i++) {
184 		if (*prefix == ':' || *prefix == '\0')
185 			break;
186 		pnbuf[i] = *prefix++;
187 	}
188 
189 	if (*prefix != ':' && *prefix != '\0') {
190 		/* Path prefix was too long. */
191 		*prefixp = NULL;
192 		return (NULL);
193 	}
194 
195 	if (*prefix != '\0')
196 		prefix++;
197 	*prefixp = prefix;
198 
199 	/*
200 	 * This sprintf() is safe because of the maxprefix calculation
201 	 * performed above.
202 	 */
203 	sprintf(&pnbuf[i], "/%s/%s", drvname, imgname);
204 
205 	return (pnbuf);
206 }
207 
208 static char *
209 firmware_path_first(const char *drvname, const char *imgname, char *pnbuf,
210     char **prefixp)
211 {
212 
213 	*prefixp = firmware_paths;
214 	return (firmware_path_next(drvname, imgname, pnbuf, prefixp));
215 }
216 
217 /*
218  * firmware_open:
219  *
220  *	Open a firmware image and return its handle.
221  */
222 int
223 firmware_open(const char *drvname, const char *imgname, firmware_handle_t *fhp)
224 {
225 	struct nameidata nd;
226 	struct vattr va;
227 	char *pnbuf, *path, *prefix;
228 	firmware_handle_t fh;
229 	struct vnode *vp;
230 	int error;
231 
232 	if (drvname == NULL || imgname == NULL)
233 		return (EINVAL);
234 
235 	pnbuf = PNBUF_GET();
236 	KASSERT(pnbuf != NULL);
237 
238 	fh = firmware_handle_alloc();
239 	KASSERT(fh != NULL);
240 
241 	error = 0;
242 	for (path = firmware_path_first(drvname, imgname, pnbuf, &prefix);
243 	     path != NULL;
244 	     path = firmware_path_next(drvname, imgname, pnbuf, &prefix)) {
245 		NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, path, curlwp);
246 		error = vn_open(&nd, FREAD, 0);
247 		if (error == ENOENT)
248 			continue;
249 		break;
250 	}
251 
252 	PNBUF_PUT(pnbuf);
253 	if (error) {
254 		firmware_handle_free(fh);
255 		return (error);
256 	}
257 
258 	vp = nd.ni_vp;
259 
260 	error = VOP_GETATTR(vp, &va, FSCRED, curlwp);
261 	if (error) {
262 		VOP_UNLOCK(vp, 0);
263 		(void)vn_close(vp, FREAD, FSCRED, curlwp);
264 		firmware_handle_free(fh);
265 		return (error);
266 	}
267 
268 	if (va.va_type != VREG) {
269 		VOP_UNLOCK(vp, 0);
270 		(void)vn_close(vp, FREAD, FSCRED, curlwp);
271 		firmware_handle_free(fh);
272 		return (EINVAL);
273 	}
274 
275 	/* XXX Mark as busy text file. */
276 
277 	fh->fh_vp = vp;
278 	fh->fh_size = va.va_size;
279 
280 	VOP_UNLOCK(vp, 0);
281 
282 	*fhp = fh;
283 	return (0);
284 }
285 
286 /*
287  * firmware_close:
288  *
289  *	Close a firmware image.
290  */
291 int
292 firmware_close(firmware_handle_t fh)
293 {
294 	int error;
295 
296 	error = vn_close(fh->fh_vp, FREAD, FSCRED, curlwp);
297 	firmware_handle_free(fh);
298 	return (error);
299 }
300 
301 /*
302  * firmware_get_size:
303  *
304  *	Return the total size of a firmware image.
305  */
306 off_t
307 firmware_get_size(firmware_handle_t fh)
308 {
309 
310 	return (fh->fh_size);
311 }
312 
313 /*
314  * firmware_read:
315  *
316  *	Read data from a firmware image at the specified offset into
317  *	the provided buffer.
318  */
319 int
320 firmware_read(firmware_handle_t fh, off_t offset, void *buf, size_t len)
321 {
322 
323 	return (vn_rdwr(UIO_READ, fh->fh_vp, buf, len, offset,
324 			UIO_SYSSPACE, 0, FSCRED, NULL, curlwp));
325 }
326 
327 /*
328  * firmware_malloc:
329  *
330  *	Allocate a firmware buffer of the specified size.
331  *
332  *	NOTE: This routine may block.
333  */
334 void *
335 firmware_malloc(size_t size)
336 {
337 
338 	return (malloc(size, M_DEVFIRM, M_WAITOK));
339 }
340 
341 /*
342  * firmware_free:
343  *
344  *	Free a previously allocated firmware buffer.
345  */
346 /*ARGSUSED*/
347 void
348 firmware_free(void *v, size_t size)
349 {
350 
351 	free(v, M_DEVFIRM);
352 }
353