xref: /netbsd-src/sys/dev/firmload.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: firmload.c,v 1.12 2010/06/24 13:03:08 hannken 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  *
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 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: firmload.c,v 1.12 2010/06/24 13:03:08 hannken Exp $");
34 
35 /*
36  * The firmload API provides an interface for device drivers to access
37  * firmware images that must be loaded onto their devices.
38  */
39 
40 #include <sys/param.h>
41 #include <sys/fcntl.h>
42 #include <sys/filedesc.h>
43 #include <sys/malloc.h>
44 #include <sys/namei.h>
45 #include <sys/systm.h>
46 #include <sys/sysctl.h>
47 #include <sys/vnode.h>
48 #include <sys/kauth.h>
49 
50 #include <dev/firmload.h>
51 
52 static MALLOC_DEFINE(M_DEVFIRM, "devfirm", "device firmware buffers");
53 
54 struct firmware_handle {
55 	struct vnode	*fh_vp;
56 	off_t		 fh_size;
57 };
58 
59 static firmware_handle_t
60 firmware_handle_alloc(void)
61 {
62 
63 	return (malloc(sizeof(struct firmware_handle), M_DEVFIRM, M_WAITOK));
64 }
65 
66 static void
67 firmware_handle_free(firmware_handle_t fh)
68 {
69 
70 	free(fh, M_DEVFIRM);
71 }
72 
73 #if !defined(FIRMWARE_PATHS)
74 #define	FIRMWARE_PATHS		\
75 	"/libdata/firmware:/usr/libdata/firmware:/usr/pkg/libdata/firmware:/usr/pkg/libdata"
76 #endif
77 
78 static char firmware_paths[PATH_MAX+1] = FIRMWARE_PATHS;
79 
80 static int
81 sysctl_hw_firmware_path(SYSCTLFN_ARGS)
82 {
83 	int error, i;
84 	char newpath[PATH_MAX+1];
85 	struct sysctlnode node;
86 	char expected_char;
87 
88 	node = *rnode;
89 	node.sysctl_data = &newpath[0];
90 	memcpy(node.sysctl_data, rnode->sysctl_data, PATH_MAX+1);
91 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
92 	if (error || newp == NULL)
93 		return (error);
94 
95 	/*
96 	 * Make sure that all of the paths in the new path list are
97 	 * absolute.
98 	 *
99 	 * When sysctl_lookup() deals with a string, it's guaranteed
100 	 * to come back nul-terminated.
101 	 */
102 	expected_char = '/';
103 	for (i = 0; i < PATH_MAX+1; i++) {
104 		if (expected_char != 0 && newpath[i] != expected_char)
105 		    	return (EINVAL);
106 		if (newpath[i] == '\0')
107 			break;
108 		else if (newpath[i] == ':')
109 			expected_char = '/';
110 		else
111 			expected_char = 0;
112 	}
113 
114 	memcpy(rnode->sysctl_data, node.sysctl_data, PATH_MAX+1);
115 
116 	return (0);
117 }
118 
119 SYSCTL_SETUP_PROTO(sysctl_hw_firmware_setup);
120 
121 SYSCTL_SETUP(sysctl_hw_firmware_setup, "sysctl hw.firmware subtree setup")
122 {
123 	const struct sysctlnode *firmware_node;
124 
125 	if (sysctl_createv(clog, 0, NULL, NULL,
126 	    CTLFLAG_PERMANENT,
127 	    CTLTYPE_NODE, "hw", NULL,
128 	    NULL, 0, NULL, 0,
129 	    CTL_HW, CTL_EOL) != 0)
130 	    	return;
131 
132 	if (sysctl_createv(clog, 0, NULL, &firmware_node,
133 	    CTLFLAG_PERMANENT,
134 	    CTLTYPE_NODE, "firmware", NULL,
135 	    NULL, 0, NULL, 0,
136 	    CTL_HW, CTL_CREATE, CTL_EOL) != 0)
137 	    	return;
138 
139 	sysctl_createv(clog, 0, NULL, NULL,
140 	    CTLFLAG_READWRITE,
141 	    CTLTYPE_STRING, "path",
142 	    SYSCTL_DESCR("Device firmware loading path list"),
143 	    sysctl_hw_firmware_path, 0, firmware_paths, PATH_MAX+1,
144 	    CTL_HW, firmware_node->sysctl_num, CTL_CREATE, CTL_EOL);
145 }
146 
147 static char *
148 firmware_path_next(const char *drvname, const char *imgname, char *pnbuf,
149     char **prefixp)
150 {
151 	char *prefix = *prefixp;
152 	size_t maxprefix, i;
153 
154 	if (prefix == NULL		/* terminated early */
155 	    || *prefix == '\0'		/* no more left */
156 	    || *prefix != '/') {	/* not absolute */
157 		*prefixp = NULL;
158 	    	return (NULL);
159 	}
160 
161 	/*
162 	 * Compute the max path prefix based on the length of the provided
163 	 * names.
164 	 */
165 	maxprefix = MAXPATHLEN -
166 		(1 /* / */
167 		 + strlen(drvname)
168 		 + 1 /* / */
169 		 + strlen(imgname)
170 		 + 1 /* terminating NUL */);
171 
172 	/* Check for underflow (size_t is unsigned). */
173 	if (maxprefix > MAXPATHLEN) {
174 		*prefixp = NULL;
175 		return (NULL);
176 	}
177 
178 	for (i = 0; i < maxprefix; i++) {
179 		if (*prefix == ':' || *prefix == '\0')
180 			break;
181 		pnbuf[i] = *prefix++;
182 	}
183 
184 	if (*prefix != ':' && *prefix != '\0') {
185 		/* Path prefix was too long. */
186 		*prefixp = NULL;
187 		return (NULL);
188 	}
189 
190 	if (*prefix != '\0')
191 		prefix++;
192 	*prefixp = prefix;
193 
194 	/*
195 	 * This sprintf() is safe because of the maxprefix calculation
196 	 * performed above.
197 	 */
198 	sprintf(&pnbuf[i], "/%s/%s", drvname, imgname);
199 
200 	return (pnbuf);
201 }
202 
203 static char *
204 firmware_path_first(const char *drvname, const char *imgname, char *pnbuf,
205     char **prefixp)
206 {
207 
208 	*prefixp = firmware_paths;
209 	return (firmware_path_next(drvname, imgname, pnbuf, prefixp));
210 }
211 
212 /*
213  * firmware_open:
214  *
215  *	Open a firmware image and return its handle.
216  */
217 int
218 firmware_open(const char *drvname, const char *imgname, firmware_handle_t *fhp)
219 {
220 	struct nameidata nd;
221 	struct vattr va;
222 	char *pnbuf, *path, *prefix;
223 	firmware_handle_t fh;
224 	struct vnode *vp;
225 	int error;
226 	extern struct cwdinfo cwdi0;
227 
228 	if (drvname == NULL || imgname == NULL)
229 		return (EINVAL);
230 
231 	if (cwdi0.cwdi_cdir == NULL) {
232 		printf("firmware_open(%s/%s) called too early.\n",
233 			drvname, imgname);
234 		return ENOENT;
235 	}
236 
237 	pnbuf = PNBUF_GET();
238 	KASSERT(pnbuf != NULL);
239 
240 	fh = firmware_handle_alloc();
241 	KASSERT(fh != NULL);
242 
243 	error = 0;
244 	for (path = firmware_path_first(drvname, imgname, pnbuf, &prefix);
245 	     path != NULL;
246 	     path = firmware_path_next(drvname, imgname, pnbuf, &prefix)) {
247 		NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, path);
248 		error = vn_open(&nd, FREAD, 0);
249 		if (error == ENOENT)
250 			continue;
251 		break;
252 	}
253 
254 	PNBUF_PUT(pnbuf);
255 	if (error) {
256 		firmware_handle_free(fh);
257 		return (error);
258 	}
259 
260 	vp = nd.ni_vp;
261 
262 	error = VOP_GETATTR(vp, &va, kauth_cred_get());
263 	if (error) {
264 		VOP_UNLOCK(vp);
265 		(void)vn_close(vp, FREAD, kauth_cred_get());
266 		firmware_handle_free(fh);
267 		return (error);
268 	}
269 
270 	if (va.va_type != VREG) {
271 		VOP_UNLOCK(vp);
272 		(void)vn_close(vp, FREAD, kauth_cred_get());
273 		firmware_handle_free(fh);
274 		return (EINVAL);
275 	}
276 
277 	/* XXX Mark as busy text file. */
278 
279 	fh->fh_vp = vp;
280 	fh->fh_size = va.va_size;
281 
282 	VOP_UNLOCK(vp);
283 
284 	*fhp = fh;
285 	return (0);
286 }
287 
288 /*
289  * firmware_close:
290  *
291  *	Close a firmware image.
292  */
293 int
294 firmware_close(firmware_handle_t fh)
295 {
296 	int error;
297 
298 	error = vn_close(fh->fh_vp, FREAD, kauth_cred_get());
299 	firmware_handle_free(fh);
300 	return (error);
301 }
302 
303 /*
304  * firmware_get_size:
305  *
306  *	Return the total size of a firmware image.
307  */
308 off_t
309 firmware_get_size(firmware_handle_t fh)
310 {
311 
312 	return (fh->fh_size);
313 }
314 
315 /*
316  * firmware_read:
317  *
318  *	Read data from a firmware image at the specified offset into
319  *	the provided buffer.
320  */
321 int
322 firmware_read(firmware_handle_t fh, off_t offset, void *buf, size_t len)
323 {
324 
325 	return (vn_rdwr(UIO_READ, fh->fh_vp, buf, len, offset,
326 			UIO_SYSSPACE, 0, kauth_cred_get(), NULL, curlwp));
327 }
328 
329 /*
330  * firmware_malloc:
331  *
332  *	Allocate a firmware buffer of the specified size.
333  *
334  *	NOTE: This routine may block.
335  */
336 void *
337 firmware_malloc(size_t size)
338 {
339 
340 	return (malloc(size, M_DEVFIRM, M_WAITOK));
341 }
342 
343 /*
344  * firmware_free:
345  *
346  *	Free a previously allocated firmware buffer.
347  */
348 /*ARGSUSED*/
349 void
350 firmware_free(void *v, size_t size)
351 {
352 
353 	free(v, M_DEVFIRM);
354 }
355