1 /* $NetBSD: firmload.c,v 1.24 2022/10/26 23:39:10 riastradh 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 1.24 2022/10/26 23:39:10 riastradh 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/kmem.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 #include <sys/lwp.h>
50
51 #include <dev/firmload.h>
52
53 struct firmware_handle {
54 struct vnode *fh_vp;
55 off_t fh_size;
56 };
57
58 static firmware_handle_t
firmware_handle_alloc(void)59 firmware_handle_alloc(void)
60 {
61
62 return (kmem_alloc(sizeof(struct firmware_handle), KM_SLEEP));
63 }
64
65 static void
firmware_handle_free(firmware_handle_t fh)66 firmware_handle_free(firmware_handle_t fh)
67 {
68
69 kmem_free(fh, sizeof(*fh));
70 }
71
72 #if !defined(FIRMWARE_PATHS)
73 #define FIRMWARE_PATHS \
74 "/libdata/firmware:/usr/libdata/firmware:/usr/pkg/libdata/firmware:/usr/pkg/libdata"
75 #endif
76
77 static char firmware_paths[PATH_MAX+1] = FIRMWARE_PATHS;
78
79 static int
sysctl_hw_firmware_path(SYSCTLFN_ARGS)80 sysctl_hw_firmware_path(SYSCTLFN_ARGS)
81 {
82 int error, i;
83 char newpath[PATH_MAX+1];
84 struct sysctlnode node;
85 char expected_char;
86
87 node = *rnode;
88 node.sysctl_data = &newpath[0];
89 memcpy(node.sysctl_data, rnode->sysctl_data, PATH_MAX+1);
90 error = sysctl_lookup(SYSCTLFN_CALL(&node));
91 if (error || newp == NULL)
92 return (error);
93
94 /*
95 * Make sure that all of the paths in the new path list are
96 * absolute.
97 *
98 * When sysctl_lookup() deals with a string, it's guaranteed
99 * to come back nul-terminated.
100 */
101 expected_char = '/';
102 for (i = 0; i < PATH_MAX+1; i++) {
103 if (expected_char != 0 && newpath[i] != expected_char)
104 return (EINVAL);
105 if (newpath[i] == '\0')
106 break;
107 else if (newpath[i] == ':')
108 expected_char = '/';
109 else
110 expected_char = 0;
111 }
112
113 memcpy(rnode->sysctl_data, node.sysctl_data, PATH_MAX+1);
114
115 return (0);
116 }
117
118 SYSCTL_SETUP(sysctl_hw_firmware_setup, "sysctl hw.firmware subtree setup")
119 {
120 const struct sysctlnode *firmware_node;
121
122 if (sysctl_createv(clog, 0, NULL, &firmware_node,
123 CTLFLAG_PERMANENT,
124 CTLTYPE_NODE, "firmware", NULL,
125 NULL, 0, NULL, 0,
126 CTL_HW, CTL_CREATE, CTL_EOL) != 0)
127 return;
128
129 sysctl_createv(clog, 0, NULL, NULL,
130 CTLFLAG_READWRITE,
131 CTLTYPE_STRING, "path",
132 SYSCTL_DESCR("Device firmware loading path list"),
133 sysctl_hw_firmware_path, 0, firmware_paths, PATH_MAX+1,
134 CTL_HW, firmware_node->sysctl_num, CTL_CREATE, CTL_EOL);
135 }
136
137 static char *
firmware_path_next(const char * drvname,const char * imgname,char * pnbuf,char ** prefixp)138 firmware_path_next(const char *drvname, const char *imgname, char *pnbuf,
139 char **prefixp)
140 {
141 char *prefix = *prefixp;
142 size_t maxprefix, i;
143
144 if (prefix == NULL /* terminated early */
145 || *prefix != '/') { /* empty or not absolute */
146 *prefixp = NULL;
147 return (NULL);
148 }
149
150 /*
151 * Compute the max path prefix based on the length of the provided
152 * names.
153 */
154 maxprefix = MAXPATHLEN -
155 (1 /* / */
156 + strlen(drvname)
157 + 1 /* / */
158 + strlen(imgname)
159 + 1 /* terminating NUL */);
160
161 /* Check for underflow (size_t is unsigned). */
162 if (maxprefix > MAXPATHLEN) {
163 *prefixp = NULL;
164 return (NULL);
165 }
166
167 for (i = 0; i < maxprefix; i++) {
168 if (*prefix == ':' || *prefix == '\0')
169 break;
170 pnbuf[i] = *prefix++;
171 }
172
173 if (*prefix != ':' && *prefix != '\0') {
174 /* Path prefix was too long. */
175 *prefixp = NULL;
176 return (NULL);
177 }
178
179 if (*prefix != '\0')
180 prefix++;
181 *prefixp = prefix;
182
183 KASSERT(MAXPATHLEN >= i);
184 snprintf(pnbuf + i, MAXPATHLEN - i, "/%s/%s", drvname, imgname);
185
186 return (pnbuf);
187 }
188
189 static char *
firmware_path_first(const char * drvname,const char * imgname,char * pnbuf,char ** prefixp)190 firmware_path_first(const char *drvname, const char *imgname, char *pnbuf,
191 char **prefixp)
192 {
193
194 *prefixp = firmware_paths;
195 return (firmware_path_next(drvname, imgname, pnbuf, prefixp));
196 }
197
198 /*
199 * firmware_open:
200 *
201 * Open a firmware image and return its handle.
202 */
203 int
firmware_open(const char * drvname,const char * imgname,firmware_handle_t * fhp)204 firmware_open(const char *drvname, const char *imgname, firmware_handle_t *fhp)
205 {
206 struct pathbuf *pb;
207 struct vattr va;
208 char *pnbuf, *path, *prefix;
209 firmware_handle_t fh;
210 struct vnode *vp;
211 int error;
212
213 if (drvname == NULL || imgname == NULL)
214 return (EINVAL);
215
216 if (cwdi0.cwdi_cdir == NULL) {
217 printf("firmware_open(%s/%s) called too early.\n",
218 drvname, imgname);
219 return ENOENT;
220 }
221
222 pnbuf = PNBUF_GET();
223 KASSERT(pnbuf != NULL);
224
225 fh = firmware_handle_alloc();
226 KASSERT(fh != NULL);
227
228 error = 0;
229 for (path = firmware_path_first(drvname, imgname, pnbuf, &prefix);
230 path != NULL;
231 path = firmware_path_next(drvname, imgname, pnbuf, &prefix)) {
232 pb = pathbuf_create(path);
233 if (pb == NULL) {
234 error = ENOMEM;
235 break;
236 }
237 error = vn_open(NULL, pb, NOCHROOT, FREAD, 0, &vp, NULL, NULL);
238 pathbuf_destroy(pb);
239 if (error == ENOENT) {
240 continue;
241 }
242 break;
243 }
244
245 PNBUF_PUT(pnbuf);
246 if (error) {
247 firmware_handle_free(fh);
248 return (error);
249 }
250
251 error = VOP_GETATTR(vp, &va, kauth_cred_get());
252 if (error) {
253 VOP_UNLOCK(vp);
254 (void)vn_close(vp, FREAD, kauth_cred_get());
255 firmware_handle_free(fh);
256 return (error);
257 }
258
259 if (va.va_type != VREG) {
260 VOP_UNLOCK(vp);
261 (void)vn_close(vp, FREAD, kauth_cred_get());
262 firmware_handle_free(fh);
263 return (EINVAL);
264 }
265
266 /* XXX Mark as busy text file. */
267
268 fh->fh_vp = vp;
269 fh->fh_size = va.va_size;
270
271 VOP_UNLOCK(vp);
272
273 *fhp = fh;
274 return (0);
275 }
276
277 /*
278 * firmware_close:
279 *
280 * Close a firmware image.
281 */
282 int
firmware_close(firmware_handle_t fh)283 firmware_close(firmware_handle_t fh)
284 {
285 int error;
286
287 error = vn_close(fh->fh_vp, FREAD, kauth_cred_get());
288 firmware_handle_free(fh);
289 return (error);
290 }
291
292 /*
293 * firmware_get_size:
294 *
295 * Return the total size of a firmware image.
296 */
297 off_t
firmware_get_size(firmware_handle_t fh)298 firmware_get_size(firmware_handle_t fh)
299 {
300
301 return (fh->fh_size);
302 }
303
304 /*
305 * firmware_read:
306 *
307 * Read data from a firmware image at the specified offset into
308 * the provided buffer.
309 */
310 int
firmware_read(firmware_handle_t fh,off_t offset,void * buf,size_t len)311 firmware_read(firmware_handle_t fh, off_t offset, void *buf, size_t len)
312 {
313
314 return (vn_rdwr(UIO_READ, fh->fh_vp, buf, len, offset,
315 UIO_SYSSPACE, 0, kauth_cred_get(), NULL, curlwp));
316 }
317
318 /*
319 * firmware_malloc:
320 *
321 * Allocate a firmware buffer of the specified size.
322 *
323 * NOTE: This routine may block.
324 */
325 void *
firmware_malloc(size_t size)326 firmware_malloc(size_t size)
327 {
328
329 return (kmem_alloc(size, KM_SLEEP));
330 }
331
332 /*
333 * firmware_free:
334 *
335 * Free a previously allocated firmware buffer.
336 */
337 /*ARGSUSED*/
338 void
firmware_free(void * v,size_t size)339 firmware_free(void *v, size_t size)
340 {
341
342 kmem_free(v, size);
343 }
344