devices.c revision 93ca79b44535ee24ece08001e1948070db6ab6ed
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 <stddef.h> 19#include <stdio.h> 20#include <stdlib.h> 21#include <sys/stat.h> 22#include <sys/types.h> 23 24#include <fcntl.h> 25#include <dirent.h> 26#include <unistd.h> 27#include <string.h> 28 29#include <sys/socket.h> 30#include <sys/un.h> 31#include <linux/netlink.h> 32 33#include <selinux/selinux.h> 34#include <selinux/label.h> 35#include <selinux/android.h> 36 37#include <private/android_filesystem_config.h> 38#include <sys/time.h> 39#include <asm/page.h> 40#include <sys/wait.h> 41 42#include <cutils/list.h> 43#include <cutils/uevent.h> 44 45#include "devices.h" 46#include "util.h" 47#include "log.h" 48 49#define SYSFS_PREFIX "/sys" 50#define FIRMWARE_DIR1 "/etc/firmware" 51#define FIRMWARE_DIR2 "/vendor/firmware" 52#define FIRMWARE_DIR3 "/firmware/image" 53 54extern struct selabel_handle *sehandle; 55 56static int device_fd = -1; 57 58struct uevent { 59 const char *action; 60 const char *path; 61 const char *subsystem; 62 const char *firmware; 63 const char *partition_name; 64 const char *device_name; 65 int partition_num; 66 int major; 67 int minor; 68}; 69 70struct perms_ { 71 char *name; 72 char *attr; 73 mode_t perm; 74 unsigned int uid; 75 unsigned int gid; 76 unsigned short prefix; 77}; 78 79struct perm_node { 80 struct perms_ dp; 81 struct listnode plist; 82}; 83 84struct platform_node { 85 char *name; 86 char *path; 87 int path_len; 88 struct listnode list; 89}; 90 91static list_declare(sys_perms); 92static list_declare(dev_perms); 93static list_declare(platform_names); 94 95int add_dev_perms(const char *name, const char *attr, 96 mode_t perm, unsigned int uid, unsigned int gid, 97 unsigned short prefix) { 98 struct perm_node *node = calloc(1, sizeof(*node)); 99 if (!node) 100 return -ENOMEM; 101 102 node->dp.name = strdup(name); 103 if (!node->dp.name) 104 return -ENOMEM; 105 106 if (attr) { 107 node->dp.attr = strdup(attr); 108 if (!node->dp.attr) 109 return -ENOMEM; 110 } 111 112 node->dp.perm = perm; 113 node->dp.uid = uid; 114 node->dp.gid = gid; 115 node->dp.prefix = prefix; 116 117 if (attr) 118 list_add_tail(&sys_perms, &node->plist); 119 else 120 list_add_tail(&dev_perms, &node->plist); 121 122 return 0; 123} 124 125void fixup_sys_perms(const char *upath) 126{ 127 char buf[512]; 128 struct listnode *node; 129 struct perms_ *dp; 130 char *secontext; 131 132 /* upaths omit the "/sys" that paths in this list 133 * contain, so we add 4 when comparing... 134 */ 135 list_for_each(node, &sys_perms) { 136 dp = &(node_to_item(node, struct perm_node, plist))->dp; 137 if (dp->prefix) { 138 if (strncmp(upath, dp->name + 4, strlen(dp->name + 4))) 139 continue; 140 } else { 141 if (strcmp(upath, dp->name + 4)) 142 continue; 143 } 144 145 if ((strlen(upath) + strlen(dp->attr) + 6) > sizeof(buf)) 146 return; 147 148 sprintf(buf,"/sys%s/%s", upath, dp->attr); 149 INFO("fixup %s %d %d 0%o\n", buf, dp->uid, dp->gid, dp->perm); 150 chown(buf, dp->uid, dp->gid); 151 chmod(buf, dp->perm); 152 if (sehandle) { 153 secontext = NULL; 154 selabel_lookup(sehandle, &secontext, buf, 0); 155 if (secontext) { 156 setfilecon(buf, secontext); 157 freecon(secontext); 158 } 159 } 160 } 161} 162 163static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid) 164{ 165 mode_t perm; 166 struct listnode *node; 167 struct perm_node *perm_node; 168 struct perms_ *dp; 169 170 /* search the perms list in reverse so that ueventd.$hardware can 171 * override ueventd.rc 172 */ 173 list_for_each_reverse(node, &dev_perms) { 174 perm_node = node_to_item(node, struct perm_node, plist); 175 dp = &perm_node->dp; 176 177 if (dp->prefix) { 178 if (strncmp(path, dp->name, strlen(dp->name))) 179 continue; 180 } else { 181 if (strcmp(path, dp->name)) 182 continue; 183 } 184 *uid = dp->uid; 185 *gid = dp->gid; 186 return dp->perm; 187 } 188 /* Default if nothing found. */ 189 *uid = 0; 190 *gid = 0; 191 return 0600; 192} 193 194static void make_device(const char *path, 195 const char *upath, 196 int block, int major, int minor) 197{ 198 unsigned uid; 199 unsigned gid; 200 mode_t mode; 201 dev_t dev; 202 char *secontext = NULL; 203 204 mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR); 205 206 if (sehandle) { 207 selabel_lookup(sehandle, &secontext, path, mode); 208 setfscreatecon(secontext); 209 } 210 211 dev = makedev(major, minor); 212 /* Temporarily change egid to avoid race condition setting the gid of the 213 * device node. Unforunately changing the euid would prevent creation of 214 * some device nodes, so the uid has to be set with chown() and is still 215 * racy. Fixing the gid race at least fixed the issue with system_server 216 * opening dynamic input devices under the AID_INPUT gid. */ 217 setegid(gid); 218 mknod(path, mode, dev); 219 chown(path, uid, -1); 220 setegid(AID_ROOT); 221 222 if (secontext) { 223 freecon(secontext); 224 setfscreatecon(NULL); 225 } 226} 227 228static void add_platform_device(const char *path) 229{ 230 int path_len = strlen(path); 231 struct listnode *node; 232 struct platform_node *bus; 233 const char *name = path; 234 235 if (!strncmp(path, "/devices/", 9)) { 236 name += 9; 237 if (!strncmp(name, "platform/", 9)) 238 name += 9; 239 } 240 241 list_for_each_reverse(node, &platform_names) { 242 bus = node_to_item(node, struct platform_node, list); 243 if ((bus->path_len < path_len) && 244 (path[bus->path_len] == '/') && 245 !strncmp(path, bus->path, bus->path_len)) 246 /* subdevice of an existing platform, ignore it */ 247 return; 248 } 249 250 INFO("adding platform device %s (%s)\n", name, path); 251 252 bus = calloc(1, sizeof(struct platform_node)); 253 bus->path = strdup(path); 254 bus->path_len = path_len; 255 bus->name = bus->path + (name - path); 256 list_add_tail(&platform_names, &bus->list); 257} 258 259/* 260 * given a path that may start with a platform device, find the length of the 261 * platform device prefix. If it doesn't start with a platform device, return 262 * 0. 263 */ 264static struct platform_node *find_platform_device(const char *path) 265{ 266 int path_len = strlen(path); 267 struct listnode *node; 268 struct platform_node *bus; 269 270 list_for_each_reverse(node, &platform_names) { 271 bus = node_to_item(node, struct platform_node, list); 272 if ((bus->path_len < path_len) && 273 (path[bus->path_len] == '/') && 274 !strncmp(path, bus->path, bus->path_len)) 275 return bus; 276 } 277 278 return NULL; 279} 280 281static void remove_platform_device(const char *path) 282{ 283 struct listnode *node; 284 struct platform_node *bus; 285 286 list_for_each_reverse(node, &platform_names) { 287 bus = node_to_item(node, struct platform_node, list); 288 if (!strcmp(path, bus->path)) { 289 INFO("removing platform device %s\n", bus->name); 290 free(bus->path); 291 list_remove(node); 292 free(bus); 293 return; 294 } 295 } 296} 297 298#if LOG_UEVENTS 299 300static inline suseconds_t get_usecs(void) 301{ 302 struct timeval tv; 303 gettimeofday(&tv, 0); 304 return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec; 305} 306 307#define log_event_print(x...) INFO(x) 308 309#else 310 311#define log_event_print(fmt, args...) do { } while (0) 312#define get_usecs() 0 313 314#endif 315 316static void parse_event(const char *msg, struct uevent *uevent) 317{ 318 uevent->action = ""; 319 uevent->path = ""; 320 uevent->subsystem = ""; 321 uevent->firmware = ""; 322 uevent->major = -1; 323 uevent->minor = -1; 324 uevent->partition_name = NULL; 325 uevent->partition_num = -1; 326 uevent->device_name = NULL; 327 328 /* currently ignoring SEQNUM */ 329 while(*msg) { 330 if(!strncmp(msg, "ACTION=", 7)) { 331 msg += 7; 332 uevent->action = msg; 333 } else if(!strncmp(msg, "DEVPATH=", 8)) { 334 msg += 8; 335 uevent->path = msg; 336 } else if(!strncmp(msg, "SUBSYSTEM=", 10)) { 337 msg += 10; 338 uevent->subsystem = msg; 339 } else if(!strncmp(msg, "FIRMWARE=", 9)) { 340 msg += 9; 341 uevent->firmware = msg; 342 } else if(!strncmp(msg, "MAJOR=", 6)) { 343 msg += 6; 344 uevent->major = atoi(msg); 345 } else if(!strncmp(msg, "MINOR=", 6)) { 346 msg += 6; 347 uevent->minor = atoi(msg); 348 } else if(!strncmp(msg, "PARTN=", 6)) { 349 msg += 6; 350 uevent->partition_num = atoi(msg); 351 } else if(!strncmp(msg, "PARTNAME=", 9)) { 352 msg += 9; 353 uevent->partition_name = msg; 354 } else if(!strncmp(msg, "DEVNAME=", 8)) { 355 msg += 8; 356 uevent->device_name = msg; 357 } 358 359 /* advance to after the next \0 */ 360 while(*msg++) 361 ; 362 } 363 364 log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n", 365 uevent->action, uevent->path, uevent->subsystem, 366 uevent->firmware, uevent->major, uevent->minor); 367} 368 369static char **get_character_device_symlinks(struct uevent *uevent) 370{ 371 const char *parent; 372 char *slash; 373 char **links; 374 int link_num = 0; 375 int width; 376 struct platform_node *pdev; 377 378 pdev = find_platform_device(uevent->path); 379 if (!pdev) 380 return NULL; 381 382 links = malloc(sizeof(char *) * 2); 383 if (!links) 384 return NULL; 385 memset(links, 0, sizeof(char *) * 2); 386 387 /* skip "/devices/platform/<driver>" */ 388 parent = strchr(uevent->path + pdev->path_len, '/'); 389 if (!*parent) 390 goto err; 391 392 if (!strncmp(parent, "/usb", 4)) { 393 /* skip root hub name and device. use device interface */ 394 while (*++parent && *parent != '/'); 395 if (*parent) 396 while (*++parent && *parent != '/'); 397 if (!*parent) 398 goto err; 399 slash = strchr(++parent, '/'); 400 if (!slash) 401 goto err; 402 width = slash - parent; 403 if (width <= 0) 404 goto err; 405 406 if (asprintf(&links[link_num], "/dev/usb/%s%.*s", uevent->subsystem, width, parent) > 0) 407 link_num++; 408 else 409 links[link_num] = NULL; 410 mkdir("/dev/usb", 0755); 411 } 412 else { 413 goto err; 414 } 415 416 return links; 417err: 418 free(links); 419 return NULL; 420} 421 422static char **parse_platform_block_device(struct uevent *uevent) 423{ 424 const char *device; 425 struct platform_node *pdev; 426 char *slash; 427 int width; 428 char buf[256]; 429 char link_path[256]; 430 int fd; 431 int link_num = 0; 432 int ret; 433 char *p; 434 unsigned int size; 435 struct stat info; 436 437 pdev = find_platform_device(uevent->path); 438 if (!pdev) 439 return NULL; 440 device = pdev->name; 441 442 char **links = malloc(sizeof(char *) * 4); 443 if (!links) 444 return NULL; 445 memset(links, 0, sizeof(char *) * 4); 446 447 INFO("found platform device %s\n", device); 448 449 snprintf(link_path, sizeof(link_path), "/dev/block/platform/%s", device); 450 451 if (uevent->partition_name) { 452 p = strdup(uevent->partition_name); 453 sanitize(p); 454 if (strcmp(uevent->partition_name, p)) 455 NOTICE("Linking partition '%s' as '%s'\n", uevent->partition_name, p); 456 if (asprintf(&links[link_num], "%s/by-name/%s", link_path, p) > 0) 457 link_num++; 458 else 459 links[link_num] = NULL; 460 free(p); 461 } 462 463 if (uevent->partition_num >= 0) { 464 if (asprintf(&links[link_num], "%s/by-num/p%d", link_path, uevent->partition_num) > 0) 465 link_num++; 466 else 467 links[link_num] = NULL; 468 } 469 470 slash = strrchr(uevent->path, '/'); 471 if (asprintf(&links[link_num], "%s/%s", link_path, slash + 1) > 0) 472 link_num++; 473 else 474 links[link_num] = NULL; 475 476 return links; 477} 478 479static void handle_device(const char *action, const char *devpath, 480 const char *path, int block, int major, int minor, char **links) 481{ 482 int i; 483 484 if(!strcmp(action, "add")) { 485 make_device(devpath, path, block, major, minor); 486 if (links) { 487 for (i = 0; links[i]; i++) 488 make_link(devpath, links[i]); 489 } 490 } 491 492 if(!strcmp(action, "remove")) { 493 if (links) { 494 for (i = 0; links[i]; i++) 495 remove_link(devpath, links[i]); 496 } 497 unlink(devpath); 498 } 499 500 if (links) { 501 for (i = 0; links[i]; i++) 502 free(links[i]); 503 free(links); 504 } 505} 506 507static void handle_platform_device_event(struct uevent *uevent) 508{ 509 const char *path = uevent->path; 510 511 if (!strcmp(uevent->action, "add")) 512 add_platform_device(path); 513 else if (!strcmp(uevent->action, "remove")) 514 remove_platform_device(path); 515} 516 517static const char *parse_device_name(struct uevent *uevent, unsigned int len) 518{ 519 const char *name; 520 521 /* if it's not a /dev device, nothing else to do */ 522 if((uevent->major < 0) || (uevent->minor < 0)) 523 return NULL; 524 525 /* do we have a name? */ 526 name = strrchr(uevent->path, '/'); 527 if(!name) 528 return NULL; 529 name++; 530 531 /* too-long names would overrun our buffer */ 532 if(strlen(name) > len) 533 return NULL; 534 535 return name; 536} 537 538static void handle_block_device_event(struct uevent *uevent) 539{ 540 const char *base = "/dev/block/"; 541 const char *name; 542 char devpath[96]; 543 char **links = NULL; 544 545 name = parse_device_name(uevent, 64); 546 if (!name) 547 return; 548 549 snprintf(devpath, sizeof(devpath), "%s%s", base, name); 550 make_dir(base, 0755); 551 552 if (!strncmp(uevent->path, "/devices/", 9)) 553 links = parse_platform_block_device(uevent); 554 555 handle_device(uevent->action, devpath, uevent->path, 1, 556 uevent->major, uevent->minor, links); 557} 558 559static void handle_generic_device_event(struct uevent *uevent) 560{ 561 char *base; 562 const char *name; 563 char devpath[96] = {0}; 564 char **links = NULL; 565 566 name = parse_device_name(uevent, 64); 567 if (!name) 568 return; 569 570 if (!strncmp(uevent->subsystem, "usb", 3)) { 571 if (!strcmp(uevent->subsystem, "usb")) { 572 if (uevent->device_name) { 573 /* 574 * create device node provided by kernel if present 575 * see drivers/base/core.c 576 */ 577 char *p = devpath; 578 snprintf(devpath, sizeof(devpath), "/dev/%s", uevent->device_name); 579 /* skip leading /dev/ */ 580 p += 5; 581 /* build directories */ 582 while (*p) { 583 if (*p == '/') { 584 *p = 0; 585 make_dir(devpath, 0755); 586 *p = '/'; 587 } 588 p++; 589 } 590 } 591 else { 592 /* This imitates the file system that would be created 593 * if we were using devfs instead. 594 * Minors are broken up into groups of 128, starting at "001" 595 */ 596 int bus_id = uevent->minor / 128 + 1; 597 int device_id = uevent->minor % 128 + 1; 598 /* build directories */ 599 make_dir("/dev/bus", 0755); 600 make_dir("/dev/bus/usb", 0755); 601 snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d", bus_id); 602 make_dir(devpath, 0755); 603 snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d/%03d", bus_id, device_id); 604 } 605 } else { 606 /* ignore other USB events */ 607 return; 608 } 609 } else if (!strncmp(uevent->subsystem, "graphics", 8)) { 610 base = "/dev/graphics/"; 611 make_dir(base, 0755); 612 } else if (!strncmp(uevent->subsystem, "drm", 3)) { 613 base = "/dev/dri/"; 614 make_dir(base, 0755); 615 } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) { 616 base = "/dev/oncrpc/"; 617 make_dir(base, 0755); 618 } else if (!strncmp(uevent->subsystem, "adsp", 4)) { 619 base = "/dev/adsp/"; 620 make_dir(base, 0755); 621 } else if (!strncmp(uevent->subsystem, "msm_camera", 10)) { 622 base = "/dev/msm_camera/"; 623 make_dir(base, 0755); 624 } else if(!strncmp(uevent->subsystem, "input", 5)) { 625 base = "/dev/input/"; 626 make_dir(base, 0755); 627 } else if(!strncmp(uevent->subsystem, "mtd", 3)) { 628 base = "/dev/mtd/"; 629 make_dir(base, 0755); 630 } else if(!strncmp(uevent->subsystem, "sound", 5)) { 631 base = "/dev/snd/"; 632 make_dir(base, 0755); 633 } else if(!strncmp(uevent->subsystem, "misc", 4) && 634 !strncmp(name, "log_", 4)) { 635 base = "/dev/log/"; 636 make_dir(base, 0755); 637 name += 4; 638 } else 639 base = "/dev/"; 640 links = get_character_device_symlinks(uevent); 641 642 if (!devpath[0]) 643 snprintf(devpath, sizeof(devpath), "%s%s", base, name); 644 645 handle_device(uevent->action, devpath, uevent->path, 0, 646 uevent->major, uevent->minor, links); 647} 648 649static void handle_device_event(struct uevent *uevent) 650{ 651 if (!strcmp(uevent->action,"add") || !strcmp(uevent->action, "change")) 652 fixup_sys_perms(uevent->path); 653 654 if (!strncmp(uevent->subsystem, "block", 5)) { 655 handle_block_device_event(uevent); 656 } else if (!strncmp(uevent->subsystem, "platform", 8)) { 657 handle_platform_device_event(uevent); 658 } else { 659 handle_generic_device_event(uevent); 660 } 661} 662 663static int load_firmware(int fw_fd, int loading_fd, int data_fd) 664{ 665 struct stat st; 666 long len_to_copy; 667 int ret = 0; 668 669 if(fstat(fw_fd, &st) < 0) 670 return -1; 671 len_to_copy = st.st_size; 672 673 write(loading_fd, "1", 1); /* start transfer */ 674 675 while (len_to_copy > 0) { 676 char buf[PAGE_SIZE]; 677 ssize_t nr; 678 679 nr = read(fw_fd, buf, sizeof(buf)); 680 if(!nr) 681 break; 682 if(nr < 0) { 683 ret = -1; 684 break; 685 } 686 687 len_to_copy -= nr; 688 while (nr > 0) { 689 ssize_t nw = 0; 690 691 nw = write(data_fd, buf + nw, nr); 692 if(nw <= 0) { 693 ret = -1; 694 goto out; 695 } 696 nr -= nw; 697 } 698 } 699 700out: 701 if(!ret) 702 write(loading_fd, "0", 1); /* successful end of transfer */ 703 else 704 write(loading_fd, "-1", 2); /* abort transfer */ 705 706 return ret; 707} 708 709static int is_booting(void) 710{ 711 return access("/dev/.booting", F_OK) == 0; 712} 713 714static void process_firmware_event(struct uevent *uevent) 715{ 716 char *root, *loading, *data, *file1 = NULL, *file2 = NULL, *file3 = NULL; 717 int l, loading_fd, data_fd, fw_fd; 718 int booting = is_booting(); 719 720 INFO("firmware: loading '%s' for '%s'\n", 721 uevent->firmware, uevent->path); 722 723 l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path); 724 if (l == -1) 725 return; 726 727 l = asprintf(&loading, "%sloading", root); 728 if (l == -1) 729 goto root_free_out; 730 731 l = asprintf(&data, "%sdata", root); 732 if (l == -1) 733 goto loading_free_out; 734 735 l = asprintf(&file1, FIRMWARE_DIR1"/%s", uevent->firmware); 736 if (l == -1) 737 goto data_free_out; 738 739 l = asprintf(&file2, FIRMWARE_DIR2"/%s", uevent->firmware); 740 if (l == -1) 741 goto data_free_out; 742 743 l = asprintf(&file3, FIRMWARE_DIR3"/%s", uevent->firmware); 744 if (l == -1) 745 goto data_free_out; 746 747 loading_fd = open(loading, O_WRONLY); 748 if(loading_fd < 0) 749 goto file_free_out; 750 751 data_fd = open(data, O_WRONLY); 752 if(data_fd < 0) 753 goto loading_close_out; 754 755try_loading_again: 756 fw_fd = open(file1, O_RDONLY); 757 if(fw_fd < 0) { 758 fw_fd = open(file2, O_RDONLY); 759 if (fw_fd < 0) { 760 fw_fd = open(file3, O_RDONLY); 761 if (fw_fd < 0) { 762 if (booting) { 763 /* If we're not fully booted, we may be missing 764 * filesystems needed for firmware, wait and retry. 765 */ 766 usleep(100000); 767 booting = is_booting(); 768 goto try_loading_again; 769 } 770 INFO("firmware: could not open '%s' %d\n", uevent->firmware, errno); 771 write(loading_fd, "-1", 2); 772 goto data_close_out; 773 } 774 } 775 } 776 777 if(!load_firmware(fw_fd, loading_fd, data_fd)) 778 INFO("firmware: copy success { '%s', '%s' }\n", root, uevent->firmware); 779 else 780 INFO("firmware: copy failure { '%s', '%s' }\n", root, uevent->firmware); 781 782 close(fw_fd); 783data_close_out: 784 close(data_fd); 785loading_close_out: 786 close(loading_fd); 787file_free_out: 788 free(file1); 789 free(file2); 790data_free_out: 791 free(data); 792loading_free_out: 793 free(loading); 794root_free_out: 795 free(root); 796} 797 798static void handle_firmware_event(struct uevent *uevent) 799{ 800 pid_t pid; 801 int ret; 802 803 if(strcmp(uevent->subsystem, "firmware")) 804 return; 805 806 if(strcmp(uevent->action, "add")) 807 return; 808 809 /* we fork, to avoid making large memory allocations in init proper */ 810 pid = fork(); 811 if (!pid) { 812 process_firmware_event(uevent); 813 exit(EXIT_SUCCESS); 814 } 815} 816 817#define UEVENT_MSG_LEN 1024 818void handle_device_fd() 819{ 820 char msg[UEVENT_MSG_LEN+2]; 821 int n; 822 while ((n = uevent_kernel_multicast_recv(device_fd, msg, UEVENT_MSG_LEN)) > 0) { 823 if(n >= UEVENT_MSG_LEN) /* overflow -- discard */ 824 continue; 825 826 msg[n] = '\0'; 827 msg[n+1] = '\0'; 828 829 struct uevent uevent; 830 parse_event(msg, &uevent); 831 832 handle_device_event(&uevent); 833 handle_firmware_event(&uevent); 834 } 835} 836 837/* Coldboot walks parts of the /sys tree and pokes the uevent files 838** to cause the kernel to regenerate device add events that happened 839** before init's device manager was started 840** 841** We drain any pending events from the netlink socket every time 842** we poke another uevent file to make sure we don't overrun the 843** socket's buffer. 844*/ 845 846static void do_coldboot(DIR *d) 847{ 848 struct dirent *de; 849 int dfd, fd; 850 851 dfd = dirfd(d); 852 853 fd = openat(dfd, "uevent", O_WRONLY); 854 if(fd >= 0) { 855 write(fd, "add\n", 4); 856 close(fd); 857 handle_device_fd(); 858 } 859 860 while((de = readdir(d))) { 861 DIR *d2; 862 863 if(de->d_type != DT_DIR || de->d_name[0] == '.') 864 continue; 865 866 fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY); 867 if(fd < 0) 868 continue; 869 870 d2 = fdopendir(fd); 871 if(d2 == 0) 872 close(fd); 873 else { 874 do_coldboot(d2); 875 closedir(d2); 876 } 877 } 878} 879 880static void coldboot(const char *path) 881{ 882 DIR *d = opendir(path); 883 if(d) { 884 do_coldboot(d); 885 closedir(d); 886 } 887} 888 889void device_init(void) 890{ 891 suseconds_t t0, t1; 892 struct stat info; 893 int fd; 894 895 sehandle = NULL; 896 if (is_selinux_enabled() > 0) { 897 sehandle = selinux_android_file_context_handle(); 898 } 899 900 /* is 256K enough? udev uses 16MB! */ 901 device_fd = uevent_open_socket(256*1024, true); 902 if(device_fd < 0) 903 return; 904 905 fcntl(device_fd, F_SETFD, FD_CLOEXEC); 906 fcntl(device_fd, F_SETFL, O_NONBLOCK); 907 908 if (stat(coldboot_done, &info) < 0) { 909 t0 = get_usecs(); 910 coldboot("/sys/class"); 911 coldboot("/sys/block"); 912 coldboot("/sys/devices"); 913 t1 = get_usecs(); 914 fd = open(coldboot_done, O_WRONLY|O_CREAT, 0000); 915 close(fd); 916 log_event_print("coldboot %ld uS\n", ((long) (t1 - t0))); 917 } else { 918 log_event_print("skipping coldboot, already done\n"); 919 } 920} 921 922int get_device_fd() 923{ 924 return device_fd; 925} 926