devices.c revision dd7bc3319deb2b77c5d07a51b7d6cd7e11b5beb0
1/* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include <errno.h> 18#include <stdio.h> 19#include <stdlib.h> 20#include <sys/stat.h> 21#include <sys/types.h> 22 23#include <fcntl.h> 24#include <dirent.h> 25#include <unistd.h> 26#include <string.h> 27 28#include <sys/socket.h> 29#include <sys/un.h> 30#include <linux/netlink.h> 31#include <private/android_filesystem_config.h> 32#include <sys/time.h> 33#include <asm/page.h> 34 35#include "init.h" 36#include "devices.h" 37 38#define CMDLINE_PREFIX "/dev" 39#define SYSFS_PREFIX "/sys" 40#define FIRMWARE_DIR "/etc/firmware" 41#define MAX_QEMU_PERM 6 42 43struct uevent { 44 const char *action; 45 const char *path; 46 const char *subsystem; 47 const char *firmware; 48 int major; 49 int minor; 50}; 51 52static int open_uevent_socket(void) 53{ 54 struct sockaddr_nl addr; 55 int sz = 64*1024; // XXX larger? udev uses 16MB! 56 int s; 57 58 memset(&addr, 0, sizeof(addr)); 59 addr.nl_family = AF_NETLINK; 60 addr.nl_pid = getpid(); 61 addr.nl_groups = 0xffffffff; 62 63 s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT); 64 if(s < 0) 65 return -1; 66 67 setsockopt(s, SOL_SOCKET, SO_RCVBUFFORCE, &sz, sizeof(sz)); 68 69 if(bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 70 close(s); 71 return -1; 72 } 73 74 return s; 75} 76 77struct perms_ { 78 char *name; 79 mode_t perm; 80 unsigned int uid; 81 unsigned int gid; 82 unsigned short prefix; 83}; 84static struct perms_ devperms[] = { 85 { "/dev/null", 0666, AID_ROOT, AID_ROOT, 0 }, 86 { "/dev/zero", 0666, AID_ROOT, AID_ROOT, 0 }, 87 { "/dev/full", 0666, AID_ROOT, AID_ROOT, 0 }, 88 { "/dev/ptmx", 0666, AID_ROOT, AID_ROOT, 0 }, 89 { "/dev/tty", 0666, AID_ROOT, AID_ROOT, 0 }, 90 { "/dev/random", 0666, AID_ROOT, AID_ROOT, 0 }, 91 { "/dev/urandom", 0666, AID_ROOT, AID_ROOT, 0 }, 92 { "/dev/ashmem", 0666, AID_ROOT, AID_ROOT, 0 }, 93 { "/dev/binder", 0666, AID_ROOT, AID_ROOT, 0 }, 94 95 /* logger should be world writable (for logging) but not readable */ 96 { "/dev/log/", 0662, AID_ROOT, AID_LOG, 1 }, 97 98 /* these should not be world writable */ 99 { "/dev/android_adb", 0660, AID_ADB, AID_ADB, 0 }, 100 { "/dev/android_adb_enable", 0660, AID_ADB, AID_ADB, 0 }, 101 { "/dev/ttyMSM0", 0600, AID_BLUETOOTH, AID_BLUETOOTH, 0 }, 102 { "/dev/ttyHS0", 0600, AID_BLUETOOTH, AID_BLUETOOTH, 0 }, 103 { "/dev/uinput", 0600, AID_BLUETOOTH, AID_BLUETOOTH, 0 }, 104 { "/dev/alarm", 0664, AID_SYSTEM, AID_RADIO, 0 }, 105 { "/dev/tty0", 0660, AID_ROOT, AID_SYSTEM, 0 }, 106 { "/dev/graphics/", 0660, AID_ROOT, AID_GRAPHICS, 1 }, 107 { "/dev/hw3d", 0660, AID_SYSTEM, AID_GRAPHICS, 0 }, 108 { "/dev/input/", 0660, AID_ROOT, AID_INPUT, 1 }, 109 { "/dev/eac", 0660, AID_ROOT, AID_AUDIO, 0 }, 110 { "/dev/cam", 0660, AID_ROOT, AID_CAMERA, 0 }, 111 { "/dev/pmem", 0660, AID_SYSTEM, AID_GRAPHICS, 0 }, 112 { "/dev/pmem_gpu", 0660, AID_SYSTEM, AID_GRAPHICS, 1 }, 113 { "/dev/pmem_adsp", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 114 { "/dev/pmem_camera", 0660, AID_SYSTEM, AID_CAMERA, 1 }, 115 { "/dev/oncrpc/", 0660, AID_ROOT, AID_SYSTEM, 1 }, 116 { "/dev/adsp/", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 117 { "/dev/mt9t013", 0660, AID_SYSTEM, AID_SYSTEM, 0 }, 118 { "/dev/akm8976_daemon",0640, AID_COMPASS, AID_SYSTEM, 0 }, 119 { "/dev/akm8976_aot", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 120 { "/dev/akm8976_pffd", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 121 { "/dev/msm_pcm_out", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 122 { "/dev/msm_pcm_in", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 123 { "/dev/msm_pcm_ctl", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 124 { "/dev/msm_snd", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 125 { "/dev/msm_mp3", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 126 { "/dev/msm_audpre", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 127 { "/dev/htc-acoustic", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 128 { "/dev/smd0", 0640, AID_RADIO, AID_RADIO, 0 }, 129 { "/dev/qmi", 0640, AID_RADIO, AID_RADIO, 0 }, 130 { "/dev/qmi0", 0640, AID_RADIO, AID_RADIO, 0 }, 131 { "/dev/qmi1", 0640, AID_RADIO, AID_RADIO, 0 }, 132 { "/dev/qmi2", 0640, AID_RADIO, AID_RADIO, 0 }, 133 { NULL, 0, 0, 0, 0 }, 134}; 135 136/* devperms_partners list and perm_node are for hardware specific /dev entries */ 137struct perm_node { 138 struct perms_ dp; 139 struct listnode plist; 140}; 141list_declare(devperms_partners); 142 143/* 144 * Permission override when in emulator mode, must be parsed before 145 * system properties is initalized. 146 */ 147static int qemu_perm_count; 148static struct perms_ qemu_perms[MAX_QEMU_PERM + 1]; 149 150int add_devperms_partners(const char *name, mode_t perm, unsigned int uid, 151 unsigned int gid, unsigned short prefix) { 152 int size; 153 struct perm_node *node = malloc(sizeof (struct perm_node)); 154 if (!node) 155 return -ENOMEM; 156 157 size = strlen(name) + 1; 158 if ((node->dp.name = malloc(size)) == NULL) 159 return -ENOMEM; 160 161 memcpy(node->dp.name, name, size); 162 node->dp.perm = perm; 163 node->dp.uid = uid; 164 node->dp.gid = gid; 165 node->dp.prefix = prefix; 166 167 list_add_tail(&devperms_partners, &node->plist); 168 return 0; 169} 170 171void qemu_init(void) { 172 qemu_perm_count = 0; 173 memset(&qemu_perms, 0, sizeof(qemu_perms)); 174} 175 176static int qemu_perm(const char* name, mode_t perm, unsigned int uid, 177 unsigned int gid, unsigned short prefix) 178{ 179 char *buf; 180 if (qemu_perm_count == MAX_QEMU_PERM) 181 return -ENOSPC; 182 183 buf = malloc(strlen(name) + 1); 184 if (!buf) 185 return -errno; 186 187 strlcpy(buf, name, strlen(name) + 1); 188 qemu_perms[qemu_perm_count].name = buf; 189 qemu_perms[qemu_perm_count].perm = perm; 190 qemu_perms[qemu_perm_count].uid = uid; 191 qemu_perms[qemu_perm_count].gid = gid; 192 qemu_perms[qemu_perm_count].prefix = prefix; 193 194 qemu_perm_count++; 195 return 0; 196} 197 198/* Permission overrides for emulator that are parsed from /proc/cmdline. */ 199void qemu_cmdline(const char* name, const char *value) 200{ 201 char *buf; 202 if (!strcmp(name, "android.ril")) { 203 /* cmd line params currently assume /dev/ prefix */ 204 if (asprintf(&buf, CMDLINE_PREFIX"/%s", value) == -1) { 205 return; 206 } 207 INFO("nani- buf:: %s\n", buf); 208 qemu_perm(buf, 0660, AID_RADIO, AID_ROOT, 0); 209 } 210} 211 212static int get_device_perm_inner(struct perms_ *perms, const char *path, 213 unsigned *uid, unsigned *gid, mode_t *perm) 214{ 215 int i; 216 for(i = 0; perms[i].name; i++) { 217 218 if(perms[i].prefix) { 219 if(strncmp(path, perms[i].name, strlen(perms[i].name))) 220 continue; 221 } else { 222 if(strcmp(path, perms[i].name)) 223 continue; 224 } 225 *uid = perms[i].uid; 226 *gid = perms[i].gid; 227 *perm = perms[i].perm; 228 return 0; 229 } 230 return -1; 231} 232 233/* First checks for emulator specific permissions specified in /proc/cmdline. */ 234static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid) 235{ 236 mode_t perm; 237 238 if (get_device_perm_inner(qemu_perms, path, uid, gid, &perm) == 0) { 239 return perm; 240 } else if (get_device_perm_inner(devperms, path, uid, gid, &perm) == 0) { 241 return perm; 242 } else { 243 struct listnode *node; 244 struct perm_node *perm_node; 245 struct perms_ *dp; 246 247 /* Check partners list. */ 248 list_for_each(node, &devperms_partners) { 249 perm_node = node_to_item(node, struct perm_node, plist); 250 dp = &perm_node->dp; 251 252 if (dp->prefix) { 253 if (strncmp(path, dp->name, strlen(dp->name))) 254 continue; 255 } else { 256 if (strcmp(path, dp->name)) 257 continue; 258 } 259 /* Found perm in partner list. */ 260 *uid = dp->uid; 261 *gid = dp->gid; 262 return dp->perm; 263 } 264 /* Default if nothing found. */ 265 *uid = 0; 266 *gid = 0; 267 return 0600; 268 } 269} 270 271static void make_device(const char *path, int block, int major, int minor) 272{ 273 unsigned uid; 274 unsigned gid; 275 mode_t mode; 276 dev_t dev; 277 278 if(major > 255 || minor > 255) 279 return; 280 281 mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR); 282 dev = (major << 8) | minor; 283 mknod(path, mode, dev); 284 chown(path, uid, gid); 285} 286 287#ifdef LOG_UEVENTS 288 289static inline suseconds_t get_usecs(void) 290{ 291 struct timeval tv; 292 gettimeofday(&tv, 0); 293 return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec; 294} 295 296#define log_event_print(x...) INFO(x) 297 298#else 299 300#define log_event_print(fmt, args...) do { } while (0) 301#define get_usecs() 0 302 303#endif 304 305static void parse_event(const char *msg, struct uevent *uevent) 306{ 307 uevent->action = ""; 308 uevent->path = ""; 309 uevent->subsystem = ""; 310 uevent->firmware = ""; 311 uevent->major = -1; 312 uevent->minor = -1; 313 314 /* currently ignoring SEQNUM */ 315 while(*msg) { 316 if(!strncmp(msg, "ACTION=", 7)) { 317 msg += 7; 318 uevent->action = msg; 319 } else if(!strncmp(msg, "DEVPATH=", 8)) { 320 msg += 8; 321 uevent->path = msg; 322 } else if(!strncmp(msg, "SUBSYSTEM=", 10)) { 323 msg += 10; 324 uevent->subsystem = msg; 325 } else if(!strncmp(msg, "FIRMWARE=", 9)) { 326 msg += 9; 327 uevent->firmware = msg; 328 } else if(!strncmp(msg, "MAJOR=", 6)) { 329 msg += 6; 330 uevent->major = atoi(msg); 331 } else if(!strncmp(msg, "MINOR=", 6)) { 332 msg += 6; 333 uevent->minor = atoi(msg); 334 } 335 336 /* advance to after the next \0 */ 337 while(*msg++) 338 ; 339 } 340 341 log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n", 342 uevent->action, uevent->path, uevent->subsystem, 343 uevent->firmware, uevent->major, uevent->minor); 344} 345 346static void handle_device_event(struct uevent *uevent) 347{ 348 char devpath[96]; 349 char *base, *name; 350 int block; 351 352 /* if it's not a /dev device, nothing to do */ 353 if((uevent->major < 0) || (uevent->minor < 0)) 354 return; 355 356 /* do we have a name? */ 357 name = strrchr(uevent->path, '/'); 358 if(!name) 359 return; 360 name++; 361 362 /* too-long names would overrun our buffer */ 363 if(strlen(name) > 64) 364 return; 365 366 /* are we block or char? where should we live? */ 367 if(!strncmp(uevent->subsystem, "block", 5)) { 368 block = 1; 369 base = "/dev/block/"; 370 mkdir(base, 0755); 371 } else { 372 block = 0; 373 /* this should probably be configurable somehow */ 374 if(!strncmp(uevent->subsystem, "graphics", 8)) { 375 base = "/dev/graphics/"; 376 mkdir(base, 0755); 377 } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) { 378 base = "/dev/oncrpc/"; 379 mkdir(base, 0755); 380 } else if (!strncmp(uevent->subsystem, "adsp", 4)) { 381 base = "/dev/adsp/"; 382 mkdir(base, 0755); 383 } else if(!strncmp(uevent->subsystem, "input", 5)) { 384 base = "/dev/input/"; 385 mkdir(base, 0755); 386 } else if(!strncmp(uevent->subsystem, "mtd", 3)) { 387 base = "/dev/mtd/"; 388 mkdir(base, 0755); 389 } else if(!strncmp(uevent->subsystem, "misc", 4) && 390 !strncmp(name, "log_", 4)) { 391 base = "/dev/log/"; 392 mkdir(base, 0755); 393 name += 4; 394 } else 395 base = "/dev/"; 396 } 397 398 snprintf(devpath, sizeof(devpath), "%s%s", base, name); 399 400 if(!strcmp(uevent->action, "add")) { 401 make_device(devpath, block, uevent->major, uevent->minor); 402 return; 403 } 404 405 if(!strcmp(uevent->action, "remove")) { 406 unlink(devpath); 407 return; 408 } 409} 410 411static int load_firmware(int fw_fd, int loading_fd, int data_fd) 412{ 413 struct stat st; 414 long len_to_copy; 415 int ret = 0; 416 417 if(fstat(fw_fd, &st) < 0) 418 return -1; 419 len_to_copy = st.st_size; 420 421 write(loading_fd, "1", 1); /* start transfer */ 422 423 while (len_to_copy > 0) { 424 char buf[PAGE_SIZE]; 425 ssize_t nr; 426 427 nr = read(fw_fd, buf, sizeof(buf)); 428 if(!nr) 429 break; 430 if(nr < 0) { 431 ret = -1; 432 break; 433 } 434 435 len_to_copy -= nr; 436 while (nr > 0) { 437 ssize_t nw = 0; 438 439 nw = write(data_fd, buf + nw, nr); 440 if(nw <= 0) { 441 ret = -1; 442 goto out; 443 } 444 nr -= nw; 445 } 446 } 447 448out: 449 if(!ret) 450 write(loading_fd, "0", 1); /* successful end of transfer */ 451 else 452 write(loading_fd, "-1", 2); /* abort transfer */ 453 454 return ret; 455} 456 457static void process_firmware_event(struct uevent *uevent) 458{ 459 char *root, *loading, *data, *file; 460 int l, loading_fd, data_fd, fw_fd; 461 462 log_event_print("firmware event { '%s', '%s' }\n", 463 uevent->path, uevent->firmware); 464 465 l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path); 466 if (l == -1) 467 return; 468 469 l = asprintf(&loading, "%sloading", root); 470 if (l == -1) 471 goto root_free_out; 472 473 l = asprintf(&data, "%sdata", root); 474 if (l == -1) 475 goto loading_free_out; 476 477 l = asprintf(&file, FIRMWARE_DIR"/%s", uevent->firmware); 478 if (l == -1) 479 goto data_free_out; 480 481 loading_fd = open(loading, O_WRONLY); 482 if(loading_fd < 0) 483 goto file_free_out; 484 485 data_fd = open(data, O_WRONLY); 486 if(data_fd < 0) 487 goto loading_close_out; 488 489 fw_fd = open(file, O_RDONLY); 490 if(fw_fd < 0) 491 goto data_close_out; 492 493 if(!load_firmware(fw_fd, loading_fd, data_fd)) 494 log_event_print("firmware copy success { '%s', '%s' }\n", root, file); 495 else 496 log_event_print("firmware copy failure { '%s', '%s' }\n", root, file); 497 498 close(fw_fd); 499data_close_out: 500 close(data_fd); 501loading_close_out: 502 close(loading_fd); 503file_free_out: 504 free(file); 505data_free_out: 506 free(data); 507loading_free_out: 508 free(loading); 509root_free_out: 510 free(root); 511} 512 513static void handle_firmware_event(struct uevent *uevent) 514{ 515 pid_t pid; 516 517 if(strcmp(uevent->subsystem, "firmware")) 518 return; 519 520 if(strcmp(uevent->action, "add")) 521 return; 522 523 /* we fork, to avoid making large memory allocations in init proper */ 524 pid = fork(); 525 if (!pid) { 526 process_firmware_event(uevent); 527 exit(EXIT_SUCCESS); 528 } 529} 530 531#define UEVENT_MSG_LEN 1024 532void handle_device_fd(int fd) 533{ 534 char msg[UEVENT_MSG_LEN+2]; 535 int n; 536 537 while((n = recv(fd, msg, UEVENT_MSG_LEN, 0)) > 0) { 538 struct uevent uevent; 539 540 if(n == UEVENT_MSG_LEN) /* overflow -- discard */ 541 continue; 542 543 msg[n] = '\0'; 544 msg[n+1] = '\0'; 545 546 parse_event(msg, &uevent); 547 548 handle_device_event(&uevent); 549 handle_firmware_event(&uevent); 550 } 551} 552 553/* Coldboot walks parts of the /sys tree and pokes the uevent files 554** to cause the kernel to regenerate device add events that happened 555** before init's device manager was started 556** 557** We drain any pending events from the netlink socket every time 558** we poke another uevent file to make sure we don't overrun the 559** socket's buffer. 560*/ 561 562static void do_coldboot(int event_fd, DIR *d) 563{ 564 struct dirent *de; 565 int dfd, fd; 566 567 dfd = dirfd(d); 568 569 fd = openat(dfd, "uevent", O_WRONLY); 570 if(fd >= 0) { 571 write(fd, "add\n", 4); 572 close(fd); 573 handle_device_fd(event_fd); 574 } 575 576 while((de = readdir(d))) { 577 DIR *d2; 578 579 if(de->d_type != DT_DIR || de->d_name[0] == '.') 580 continue; 581 582 fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY); 583 if(fd < 0) 584 continue; 585 586 d2 = fdopendir(fd); 587 if(d2 == 0) 588 close(fd); 589 else { 590 do_coldboot(event_fd, d2); 591 closedir(d2); 592 } 593 } 594} 595 596static void coldboot(int event_fd, const char *path) 597{ 598 DIR *d = opendir(path); 599 if(d) { 600 do_coldboot(event_fd, d); 601 closedir(d); 602 } 603} 604 605int device_init(void) 606{ 607 suseconds_t t0, t1; 608 int fd; 609 610 fd = open_uevent_socket(); 611 if(fd < 0) 612 return -1; 613 614 fcntl(fd, F_SETFD, FD_CLOEXEC); 615 fcntl(fd, F_SETFL, O_NONBLOCK); 616 617 t0 = get_usecs(); 618 coldboot(fd, "/sys/class"); 619 coldboot(fd, "/sys/block"); 620 coldboot(fd, "/sys/devices"); 621 t1 = get_usecs(); 622 623 log_event_print("coldboot %ld uS\n", ((long) (t1 - t0))); 624 625 return fd; 626} 627