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 #include <sys/wait.h> 35 36 #include "devices.h" 37 #include "util.h" 38 #include "log.h" 39 #include "list.h" 40 41 #define SYSFS_PREFIX "/sys" 42 #define FIRMWARE_DIR1 "/etc/firmware" 43 #define FIRMWARE_DIR2 "/vendor/firmware" 44 45 static int device_fd = -1; 46 47 struct uevent { 48 const char *action; 49 const char *path; 50 const char *subsystem; 51 const char *firmware; 52 const char *partition_name; 53 int partition_num; 54 int major; 55 int minor; 56 }; 57 58 static int open_uevent_socket(void) 59 { 60 struct sockaddr_nl addr; 61 int sz = 64*1024; // XXX larger? udev uses 16MB! 62 int on = 1; 63 int s; 64 65 memset(&addr, 0, sizeof(addr)); 66 addr.nl_family = AF_NETLINK; 67 addr.nl_pid = getpid(); 68 addr.nl_groups = 0xffffffff; 69 70 s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT); 71 if(s < 0) 72 return -1; 73 74 setsockopt(s, SOL_SOCKET, SO_RCVBUFFORCE, &sz, sizeof(sz)); 75 setsockopt(s, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); 76 77 if(bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 78 close(s); 79 return -1; 80 } 81 82 return s; 83 } 84 85 struct perms_ { 86 char *name; 87 char *attr; 88 mode_t perm; 89 unsigned int uid; 90 unsigned int gid; 91 unsigned short prefix; 92 }; 93 94 struct perm_node { 95 struct perms_ dp; 96 struct listnode plist; 97 }; 98 99 static list_declare(sys_perms); 100 static list_declare(dev_perms); 101 102 int add_dev_perms(const char *name, const char *attr, 103 mode_t perm, unsigned int uid, unsigned int gid, 104 unsigned short prefix) { 105 struct perm_node *node = calloc(1, sizeof(*node)); 106 if (!node) 107 return -ENOMEM; 108 109 node->dp.name = strdup(name); 110 if (!node->dp.name) 111 return -ENOMEM; 112 113 if (attr) { 114 node->dp.attr = strdup(attr); 115 if (!node->dp.attr) 116 return -ENOMEM; 117 } 118 119 node->dp.perm = perm; 120 node->dp.uid = uid; 121 node->dp.gid = gid; 122 node->dp.prefix = prefix; 123 124 if (attr) 125 list_add_tail(&sys_perms, &node->plist); 126 else 127 list_add_tail(&dev_perms, &node->plist); 128 129 return 0; 130 } 131 132 void fixup_sys_perms(const char *upath) 133 { 134 char buf[512]; 135 struct listnode *node; 136 struct perms_ *dp; 137 138 /* upaths omit the "/sys" that paths in this list 139 * contain, so we add 4 when comparing... 140 */ 141 list_for_each(node, &sys_perms) { 142 dp = &(node_to_item(node, struct perm_node, plist))->dp; 143 if (dp->prefix) { 144 if (strncmp(upath, dp->name + 4, strlen(dp->name + 4))) 145 continue; 146 } else { 147 if (strcmp(upath, dp->name + 4)) 148 continue; 149 } 150 151 if ((strlen(upath) + strlen(dp->attr) + 6) > sizeof(buf)) 152 return; 153 154 sprintf(buf,"/sys%s/%s", upath, dp->attr); 155 INFO("fixup %s %d %d 0%o\n", buf, dp->uid, dp->gid, dp->perm); 156 chown(buf, dp->uid, dp->gid); 157 chmod(buf, dp->perm); 158 } 159 } 160 161 static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid) 162 { 163 mode_t perm; 164 struct listnode *node; 165 struct perm_node *perm_node; 166 struct perms_ *dp; 167 168 /* search the perms list in reverse so that ueventd.$hardware can 169 * override ueventd.rc 170 */ 171 list_for_each_reverse(node, &dev_perms) { 172 perm_node = node_to_item(node, struct perm_node, plist); 173 dp = &perm_node->dp; 174 175 if (dp->prefix) { 176 if (strncmp(path, dp->name, strlen(dp->name))) 177 continue; 178 } else { 179 if (strcmp(path, dp->name)) 180 continue; 181 } 182 *uid = dp->uid; 183 *gid = dp->gid; 184 return dp->perm; 185 } 186 /* Default if nothing found. */ 187 *uid = 0; 188 *gid = 0; 189 return 0600; 190 } 191 192 static void make_device(const char *path, 193 const char *upath, 194 int block, int major, int minor) 195 { 196 unsigned uid; 197 unsigned gid; 198 mode_t mode; 199 dev_t dev; 200 201 mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR); 202 dev = makedev(major, minor); 203 /* Temporarily change egid to avoid race condition setting the gid of the 204 * device node. Unforunately changing the euid would prevent creation of 205 * some device nodes, so the uid has to be set with chown() and is still 206 * racy. Fixing the gid race at least fixed the issue with system_server 207 * opening dynamic input devices under the AID_INPUT gid. */ 208 setegid(gid); 209 mknod(path, mode, dev); 210 chown(path, uid, -1); 211 setegid(AID_ROOT); 212 } 213 214 #if LOG_UEVENTS 215 216 static inline suseconds_t get_usecs(void) 217 { 218 struct timeval tv; 219 gettimeofday(&tv, 0); 220 return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec; 221 } 222 223 #define log_event_print(x...) INFO(x) 224 225 #else 226 227 #define log_event_print(fmt, args...) do { } while (0) 228 #define get_usecs() 0 229 230 #endif 231 232 static void parse_event(const char *msg, struct uevent *uevent) 233 { 234 uevent->action = ""; 235 uevent->path = ""; 236 uevent->subsystem = ""; 237 uevent->firmware = ""; 238 uevent->major = -1; 239 uevent->minor = -1; 240 uevent->partition_name = NULL; 241 uevent->partition_num = -1; 242 243 /* currently ignoring SEQNUM */ 244 while(*msg) { 245 if(!strncmp(msg, "ACTION=", 7)) { 246 msg += 7; 247 uevent->action = msg; 248 } else if(!strncmp(msg, "DEVPATH=", 8)) { 249 msg += 8; 250 uevent->path = msg; 251 } else if(!strncmp(msg, "SUBSYSTEM=", 10)) { 252 msg += 10; 253 uevent->subsystem = msg; 254 } else if(!strncmp(msg, "FIRMWARE=", 9)) { 255 msg += 9; 256 uevent->firmware = msg; 257 } else if(!strncmp(msg, "MAJOR=", 6)) { 258 msg += 6; 259 uevent->major = atoi(msg); 260 } else if(!strncmp(msg, "MINOR=", 6)) { 261 msg += 6; 262 uevent->minor = atoi(msg); 263 } else if(!strncmp(msg, "PARTN=", 6)) { 264 msg += 6; 265 uevent->partition_num = atoi(msg); 266 } else if(!strncmp(msg, "PARTNAME=", 9)) { 267 msg += 9; 268 uevent->partition_name = msg; 269 } 270 271 /* advance to after the next \0 */ 272 while(*msg++) 273 ; 274 } 275 276 log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n", 277 uevent->action, uevent->path, uevent->subsystem, 278 uevent->firmware, uevent->major, uevent->minor); 279 } 280 281 static char **parse_platform_block_device(struct uevent *uevent) 282 { 283 const char *driver; 284 const char *path; 285 char *slash; 286 int width; 287 char buf[256]; 288 char link_path[256]; 289 int fd; 290 int link_num = 0; 291 int ret; 292 char *p; 293 unsigned int size; 294 struct stat info; 295 296 char **links = malloc(sizeof(char *) * 4); 297 if (!links) 298 return NULL; 299 memset(links, 0, sizeof(char *) * 4); 300 301 /* Drop "/devices/platform/" */ 302 path = uevent->path; 303 driver = path + 18; 304 slash = strchr(driver, '/'); 305 if (!slash) 306 goto err; 307 width = slash - driver; 308 if (width <= 0) 309 goto err; 310 311 snprintf(link_path, sizeof(link_path), "/dev/block/platform/%.*s", 312 width, driver); 313 314 if (uevent->partition_name) { 315 p = strdup(uevent->partition_name); 316 sanitize(p); 317 if (asprintf(&links[link_num], "%s/by-name/%s", link_path, p) > 0) 318 link_num++; 319 else 320 links[link_num] = NULL; 321 free(p); 322 } 323 324 if (uevent->partition_num >= 0) { 325 if (asprintf(&links[link_num], "%s/by-num/p%d", link_path, uevent->partition_num) > 0) 326 link_num++; 327 else 328 links[link_num] = NULL; 329 } 330 331 slash = strrchr(path, '/'); 332 if (asprintf(&links[link_num], "%s/%s", link_path, slash + 1) > 0) 333 link_num++; 334 else 335 links[link_num] = NULL; 336 337 return links; 338 339 err: 340 free(links); 341 return NULL; 342 } 343 344 static void handle_device_event(struct uevent *uevent) 345 { 346 char devpath[96]; 347 int devpath_ready = 0; 348 char *base, *name; 349 char **links = NULL; 350 int block; 351 int i; 352 353 if (!strcmp(uevent->action,"add")) 354 fixup_sys_perms(uevent->path); 355 356 /* if it's not a /dev device, nothing else to do */ 357 if((uevent->major < 0) || (uevent->minor < 0)) 358 return; 359 360 /* do we have a name? */ 361 name = strrchr(uevent->path, '/'); 362 if(!name) 363 return; 364 name++; 365 366 /* too-long names would overrun our buffer */ 367 if(strlen(name) > 64) 368 return; 369 370 /* are we block or char? where should we live? */ 371 if(!strncmp(uevent->subsystem, "block", 5)) { 372 block = 1; 373 base = "/dev/block/"; 374 mkdir(base, 0755); 375 if (!strncmp(uevent->path, "/devices/platform/", 18)) 376 links = parse_platform_block_device(uevent); 377 } else { 378 block = 0; 379 /* this should probably be configurable somehow */ 380 if (!strncmp(uevent->subsystem, "usb", 3)) { 381 if (!strcmp(uevent->subsystem, "usb")) { 382 /* This imitates the file system that would be created 383 * if we were using devfs instead. 384 * Minors are broken up into groups of 128, starting at "001" 385 */ 386 int bus_id = uevent->minor / 128 + 1; 387 int device_id = uevent->minor % 128 + 1; 388 /* build directories */ 389 mkdir("/dev/bus", 0755); 390 mkdir("/dev/bus/usb", 0755); 391 snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d", bus_id); 392 mkdir(devpath, 0755); 393 snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d/%03d", bus_id, device_id); 394 devpath_ready = 1; 395 } else { 396 /* ignore other USB events */ 397 return; 398 } 399 } else if (!strncmp(uevent->subsystem, "graphics", 8)) { 400 base = "/dev/graphics/"; 401 mkdir(base, 0755); 402 } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) { 403 base = "/dev/oncrpc/"; 404 mkdir(base, 0755); 405 } else if (!strncmp(uevent->subsystem, "adsp", 4)) { 406 base = "/dev/adsp/"; 407 mkdir(base, 0755); 408 } else if (!strncmp(uevent->subsystem, "msm_camera", 10)) { 409 base = "/dev/msm_camera/"; 410 mkdir(base, 0755); 411 } else if(!strncmp(uevent->subsystem, "input", 5)) { 412 base = "/dev/input/"; 413 mkdir(base, 0755); 414 } else if(!strncmp(uevent->subsystem, "mtd", 3)) { 415 base = "/dev/mtd/"; 416 mkdir(base, 0755); 417 } else if(!strncmp(uevent->subsystem, "sound", 5)) { 418 base = "/dev/snd/"; 419 mkdir(base, 0755); 420 } else if(!strncmp(uevent->subsystem, "misc", 4) && 421 !strncmp(name, "log_", 4)) { 422 base = "/dev/log/"; 423 mkdir(base, 0755); 424 name += 4; 425 } else 426 base = "/dev/"; 427 } 428 429 if (!devpath_ready) 430 snprintf(devpath, sizeof(devpath), "%s%s", base, name); 431 432 if(!strcmp(uevent->action, "add")) { 433 make_device(devpath, uevent->path, block, uevent->major, uevent->minor); 434 if (links) { 435 for (i = 0; links[i]; i++) 436 make_link(devpath, links[i]); 437 } 438 } 439 440 if(!strcmp(uevent->action, "remove")) { 441 if (links) { 442 for (i = 0; links[i]; i++) 443 remove_link(devpath, links[i]); 444 } 445 unlink(devpath); 446 } 447 448 if (links) { 449 for (i = 0; links[i]; i++) 450 free(links[i]); 451 free(links); 452 } 453 } 454 455 static int load_firmware(int fw_fd, int loading_fd, int data_fd) 456 { 457 struct stat st; 458 long len_to_copy; 459 int ret = 0; 460 461 if(fstat(fw_fd, &st) < 0) 462 return -1; 463 len_to_copy = st.st_size; 464 465 write(loading_fd, "1", 1); /* start transfer */ 466 467 while (len_to_copy > 0) { 468 char buf[PAGE_SIZE]; 469 ssize_t nr; 470 471 nr = read(fw_fd, buf, sizeof(buf)); 472 if(!nr) 473 break; 474 if(nr < 0) { 475 ret = -1; 476 break; 477 } 478 479 len_to_copy -= nr; 480 while (nr > 0) { 481 ssize_t nw = 0; 482 483 nw = write(data_fd, buf + nw, nr); 484 if(nw <= 0) { 485 ret = -1; 486 goto out; 487 } 488 nr -= nw; 489 } 490 } 491 492 out: 493 if(!ret) 494 write(loading_fd, "0", 1); /* successful end of transfer */ 495 else 496 write(loading_fd, "-1", 2); /* abort transfer */ 497 498 return ret; 499 } 500 501 static void process_firmware_event(struct uevent *uevent) 502 { 503 char *root, *loading, *data, *file1 = NULL, *file2 = NULL; 504 int l, loading_fd, data_fd, fw_fd; 505 506 log_event_print("firmware event { '%s', '%s' }\n", 507 uevent->path, uevent->firmware); 508 509 l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path); 510 if (l == -1) 511 return; 512 513 l = asprintf(&loading, "%sloading", root); 514 if (l == -1) 515 goto root_free_out; 516 517 l = asprintf(&data, "%sdata", root); 518 if (l == -1) 519 goto loading_free_out; 520 521 l = asprintf(&file1, FIRMWARE_DIR1"/%s", uevent->firmware); 522 if (l == -1) 523 goto data_free_out; 524 525 l = asprintf(&file2, FIRMWARE_DIR2"/%s", uevent->firmware); 526 if (l == -1) 527 goto data_free_out; 528 529 loading_fd = open(loading, O_WRONLY); 530 if(loading_fd < 0) 531 goto file_free_out; 532 533 data_fd = open(data, O_WRONLY); 534 if(data_fd < 0) 535 goto loading_close_out; 536 537 fw_fd = open(file1, O_RDONLY); 538 if(fw_fd < 0) { 539 fw_fd = open(file2, O_RDONLY); 540 if(fw_fd < 0) 541 goto data_close_out; 542 } 543 544 if(!load_firmware(fw_fd, loading_fd, data_fd)) 545 log_event_print("firmware copy success { '%s', '%s' }\n", root, uevent->firmware); 546 else 547 log_event_print("firmware copy failure { '%s', '%s' }\n", root, uevent->firmware); 548 549 close(fw_fd); 550 data_close_out: 551 close(data_fd); 552 loading_close_out: 553 close(loading_fd); 554 file_free_out: 555 free(file1); 556 free(file2); 557 data_free_out: 558 free(data); 559 loading_free_out: 560 free(loading); 561 root_free_out: 562 free(root); 563 } 564 565 static void handle_firmware_event(struct uevent *uevent) 566 { 567 pid_t pid; 568 int status; 569 int ret; 570 571 if(strcmp(uevent->subsystem, "firmware")) 572 return; 573 574 if(strcmp(uevent->action, "add")) 575 return; 576 577 /* we fork, to avoid making large memory allocations in init proper */ 578 pid = fork(); 579 if (!pid) { 580 process_firmware_event(uevent); 581 exit(EXIT_SUCCESS); 582 } else { 583 do { 584 ret = waitpid(pid, &status, 0); 585 } while (ret == -1 && errno == EINTR); 586 } 587 } 588 589 #define UEVENT_MSG_LEN 1024 590 void handle_device_fd() 591 { 592 for(;;) { 593 char msg[UEVENT_MSG_LEN+2]; 594 char cred_msg[CMSG_SPACE(sizeof(struct ucred))]; 595 struct iovec iov = {msg, sizeof(msg)}; 596 struct sockaddr_nl snl; 597 struct msghdr hdr = {&snl, sizeof(snl), &iov, 1, cred_msg, sizeof(cred_msg), 0}; 598 599 ssize_t n = recvmsg(device_fd, &hdr, 0); 600 if (n <= 0) { 601 break; 602 } 603 604 if ((snl.nl_groups != 1) || (snl.nl_pid != 0)) { 605 /* ignoring non-kernel netlink multicast message */ 606 continue; 607 } 608 609 struct cmsghdr * cmsg = CMSG_FIRSTHDR(&hdr); 610 if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) { 611 /* no sender credentials received, ignore message */ 612 continue; 613 } 614 615 struct ucred * cred = (struct ucred *)CMSG_DATA(cmsg); 616 if (cred->uid != 0) { 617 /* message from non-root user, ignore */ 618 continue; 619 } 620 621 if(n >= UEVENT_MSG_LEN) /* overflow -- discard */ 622 continue; 623 624 msg[n] = '\0'; 625 msg[n+1] = '\0'; 626 627 struct uevent uevent; 628 parse_event(msg, &uevent); 629 630 handle_device_event(&uevent); 631 handle_firmware_event(&uevent); 632 } 633 } 634 635 /* Coldboot walks parts of the /sys tree and pokes the uevent files 636 ** to cause the kernel to regenerate device add events that happened 637 ** before init's device manager was started 638 ** 639 ** We drain any pending events from the netlink socket every time 640 ** we poke another uevent file to make sure we don't overrun the 641 ** socket's buffer. 642 */ 643 644 static void do_coldboot(DIR *d) 645 { 646 struct dirent *de; 647 int dfd, fd; 648 649 dfd = dirfd(d); 650 651 fd = openat(dfd, "uevent", O_WRONLY); 652 if(fd >= 0) { 653 write(fd, "add\n", 4); 654 close(fd); 655 handle_device_fd(); 656 } 657 658 while((de = readdir(d))) { 659 DIR *d2; 660 661 if(de->d_type != DT_DIR || de->d_name[0] == '.') 662 continue; 663 664 fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY); 665 if(fd < 0) 666 continue; 667 668 d2 = fdopendir(fd); 669 if(d2 == 0) 670 close(fd); 671 else { 672 do_coldboot(d2); 673 closedir(d2); 674 } 675 } 676 } 677 678 static void coldboot(const char *path) 679 { 680 DIR *d = opendir(path); 681 if(d) { 682 do_coldboot(d); 683 closedir(d); 684 } 685 } 686 687 void device_init(void) 688 { 689 suseconds_t t0, t1; 690 struct stat info; 691 int fd; 692 693 device_fd = open_uevent_socket(); 694 if(device_fd < 0) 695 return; 696 697 fcntl(device_fd, F_SETFD, FD_CLOEXEC); 698 fcntl(device_fd, F_SETFL, O_NONBLOCK); 699 700 if (stat(coldboot_done, &info) < 0) { 701 t0 = get_usecs(); 702 coldboot("/sys/class"); 703 coldboot("/sys/block"); 704 coldboot("/sys/devices"); 705 t1 = get_usecs(); 706 fd = open(coldboot_done, O_WRONLY|O_CREAT, 0000); 707 close(fd); 708 log_event_print("coldboot %ld uS\n", ((long) (t1 - t0))); 709 } else { 710 log_event_print("skipping coldboot, already done\n"); 711 } 712 } 713 714 int get_device_fd() 715 { 716 return device_fd; 717 } 718
