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 53struct firmware_handle { 54 struct vnode *fh_vp; 55 off_t fh_size; 56}; 57 58static firmware_handle_t 59firmware_handle_alloc(void) 60{ 61 62 return (kmem_alloc(sizeof(struct firmware_handle), KM_SLEEP)); 63} 64 65static void 66firmware_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 77static char firmware_paths[PATH_MAX+1] = FIRMWARE_PATHS; 78 79static int 80sysctl_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 118SYSCTL_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 137static char * 138firmware_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 189static char * 190firmware_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 */ 203int 204firmware_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 */ 282int 283firmware_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 */ 297off_t 298firmware_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 */ 310int 311firmware_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 */ 325void * 326firmware_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*/ 338void 339firmware_free(void *v, size_t size) 340{ 341 342 kmem_free(v, size); 343} 344