xref: /netbsd-src/sys/dev/firmload.c (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
1 /*	$NetBSD: firmload.c,v 1.3 2006/05/14 21:42:26 elad 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 1.3 2006/05/14 21:42:26 elad 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, FSCRED, curlwp);
262 	if (error) {
263 		VOP_UNLOCK(vp, 0);
264 		(void)vn_close(vp, FREAD, FSCRED, 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, FSCRED, 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, FSCRED, 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, FSCRED, 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