devices.c revision be65da47e69c427d6326603e7eccd84957cc34d2
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", 0660, AID_SYSTEM, 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/msm_camera/", 0660, AID_SYSTEM, AID_SYSTEM, 1 }, 119 { "/dev/akm8976_daemon",0640, AID_COMPASS, AID_SYSTEM, 0 }, 120 { "/dev/akm8976_aot", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 121 { "/dev/akm8973_daemon",0640, AID_COMPASS, AID_SYSTEM, 0 }, 122 { "/dev/akm8973_aot", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 123 { "/dev/bma150", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 124 { "/dev/cm3602", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 125 { "/dev/akm8976_pffd", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 126 { "/dev/msm_pcm_out", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 127 { "/dev/msm_pcm_in", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 128 { "/dev/msm_pcm_ctl", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 129 { "/dev/msm_snd", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 130 { "/dev/msm_mp3", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 131 { "/dev/msm_audpre", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 132 { "/dev/htc-acoustic", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 133 { "/dev/snd/dsp", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 134 { "/dev/snd/dsp1", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 135 { "/dev/snd/mixer", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 136 { "/dev/smd0", 0640, AID_RADIO, AID_RADIO, 0 }, 137 { "/dev/qemu_trace", 0666, AID_SYSTEM, AID_SYSTEM, 0 }, 138 { "/dev/qmi", 0640, AID_RADIO, AID_RADIO, 0 }, 139 { "/dev/qmi0", 0640, AID_RADIO, AID_RADIO, 0 }, 140 { "/dev/qmi1", 0640, AID_RADIO, AID_RADIO, 0 }, 141 { "/dev/qmi2", 0640, AID_RADIO, AID_RADIO, 0 }, 142 /* CDMA radio interface MUX */ 143 { "/dev/ts0710mux", 0640, AID_RADIO, AID_RADIO, 1 }, 144 { "/dev/ppp", 0660, AID_RADIO, AID_VPN, 0 }, 145 { "/dev/tun", 0640, AID_VPN, AID_VPN, 0 }, 146 { NULL, 0, 0, 0, 0 }, 147}; 148 149/* devperms_partners list and perm_node are for hardware specific /dev entries */ 150struct perm_node { 151 struct perms_ dp; 152 struct listnode plist; 153}; 154list_declare(devperms_partners); 155 156/* 157 * Permission override when in emulator mode, must be parsed before 158 * system properties is initalized. 159 */ 160static int qemu_perm_count; 161static struct perms_ qemu_perms[MAX_QEMU_PERM + 1]; 162 163int add_devperms_partners(const char *name, mode_t perm, unsigned int uid, 164 unsigned int gid, unsigned short prefix) { 165 int size; 166 struct perm_node *node = malloc(sizeof (struct perm_node)); 167 if (!node) 168 return -ENOMEM; 169 170 size = strlen(name) + 1; 171 if ((node->dp.name = malloc(size)) == NULL) 172 return -ENOMEM; 173 174 memcpy(node->dp.name, name, size); 175 node->dp.perm = perm; 176 node->dp.uid = uid; 177 node->dp.gid = gid; 178 node->dp.prefix = prefix; 179 180 list_add_tail(&devperms_partners, &node->plist); 181 return 0; 182} 183 184void qemu_init(void) { 185 qemu_perm_count = 0; 186 memset(&qemu_perms, 0, sizeof(qemu_perms)); 187} 188 189static int qemu_perm(const char* name, mode_t perm, unsigned int uid, 190 unsigned int gid, unsigned short prefix) 191{ 192 char *buf; 193 if (qemu_perm_count == MAX_QEMU_PERM) 194 return -ENOSPC; 195 196 buf = malloc(strlen(name) + 1); 197 if (!buf) 198 return -errno; 199 200 strlcpy(buf, name, strlen(name) + 1); 201 qemu_perms[qemu_perm_count].name = buf; 202 qemu_perms[qemu_perm_count].perm = perm; 203 qemu_perms[qemu_perm_count].uid = uid; 204 qemu_perms[qemu_perm_count].gid = gid; 205 qemu_perms[qemu_perm_count].prefix = prefix; 206 207 qemu_perm_count++; 208 return 0; 209} 210 211/* Permission overrides for emulator that are parsed from /proc/cmdline. */ 212void qemu_cmdline(const char* name, const char *value) 213{ 214 char *buf; 215 if (!strcmp(name, "android.ril")) { 216 /* cmd line params currently assume /dev/ prefix */ 217 if (asprintf(&buf, CMDLINE_PREFIX"/%s", value) == -1) { 218 return; 219 } 220 INFO("nani- buf:: %s\n", buf); 221 qemu_perm(buf, 0660, AID_RADIO, AID_ROOT, 0); 222 } 223} 224 225static int get_device_perm_inner(struct perms_ *perms, const char *path, 226 unsigned *uid, unsigned *gid, mode_t *perm) 227{ 228 int i; 229 for(i = 0; perms[i].name; i++) { 230 231 if(perms[i].prefix) { 232 if(strncmp(path, perms[i].name, strlen(perms[i].name))) 233 continue; 234 } else { 235 if(strcmp(path, perms[i].name)) 236 continue; 237 } 238 *uid = perms[i].uid; 239 *gid = perms[i].gid; 240 *perm = perms[i].perm; 241 return 0; 242 } 243 return -1; 244} 245 246/* First checks for emulator specific permissions specified in /proc/cmdline. */ 247static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid) 248{ 249 mode_t perm; 250 251 if (get_device_perm_inner(qemu_perms, path, uid, gid, &perm) == 0) { 252 return perm; 253 } else if (get_device_perm_inner(devperms, path, uid, gid, &perm) == 0) { 254 return perm; 255 } else { 256 struct listnode *node; 257 struct perm_node *perm_node; 258 struct perms_ *dp; 259 260 /* Check partners list. */ 261 list_for_each(node, &devperms_partners) { 262 perm_node = node_to_item(node, struct perm_node, plist); 263 dp = &perm_node->dp; 264 265 if (dp->prefix) { 266 if (strncmp(path, dp->name, strlen(dp->name))) 267 continue; 268 } else { 269 if (strcmp(path, dp->name)) 270 continue; 271 } 272 /* Found perm in partner list. */ 273 *uid = dp->uid; 274 *gid = dp->gid; 275 return dp->perm; 276 } 277 /* Default if nothing found. */ 278 *uid = 0; 279 *gid = 0; 280 return 0600; 281 } 282} 283 284static void make_device(const char *path, int block, int major, int minor) 285{ 286 unsigned uid; 287 unsigned gid; 288 mode_t mode; 289 dev_t dev; 290 291 if(major > 255 || minor > 255) 292 return; 293 294 mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR); 295 dev = (major << 8) | minor; 296 mknod(path, mode, dev); 297 chown(path, uid, gid); 298} 299 300#ifdef LOG_UEVENTS 301 302static inline suseconds_t get_usecs(void) 303{ 304 struct timeval tv; 305 gettimeofday(&tv, 0); 306 return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec; 307} 308 309#define log_event_print(x...) INFO(x) 310 311#else 312 313#define log_event_print(fmt, args...) do { } while (0) 314#define get_usecs() 0 315 316#endif 317 318static void parse_event(const char *msg, struct uevent *uevent) 319{ 320 uevent->action = ""; 321 uevent->path = ""; 322 uevent->subsystem = ""; 323 uevent->firmware = ""; 324 uevent->major = -1; 325 uevent->minor = -1; 326 327 /* currently ignoring SEQNUM */ 328 while(*msg) { 329 if(!strncmp(msg, "ACTION=", 7)) { 330 msg += 7; 331 uevent->action = msg; 332 } else if(!strncmp(msg, "DEVPATH=", 8)) { 333 msg += 8; 334 uevent->path = msg; 335 } else if(!strncmp(msg, "SUBSYSTEM=", 10)) { 336 msg += 10; 337 uevent->subsystem = msg; 338 } else if(!strncmp(msg, "FIRMWARE=", 9)) { 339 msg += 9; 340 uevent->firmware = msg; 341 } else if(!strncmp(msg, "MAJOR=", 6)) { 342 msg += 6; 343 uevent->major = atoi(msg); 344 } else if(!strncmp(msg, "MINOR=", 6)) { 345 msg += 6; 346 uevent->minor = atoi(msg); 347 } 348 349 /* advance to after the next \0 */ 350 while(*msg++) 351 ; 352 } 353 354 log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n", 355 uevent->action, uevent->path, uevent->subsystem, 356 uevent->firmware, uevent->major, uevent->minor); 357} 358 359static void handle_device_event(struct uevent *uevent) 360{ 361 char devpath[96]; 362 char *base, *name; 363 int block; 364 365 /* if it's not a /dev device, nothing to do */ 366 if((uevent->major < 0) || (uevent->minor < 0)) 367 return; 368 369 /* do we have a name? */ 370 name = strrchr(uevent->path, '/'); 371 if(!name) 372 return; 373 name++; 374 375 /* too-long names would overrun our buffer */ 376 if(strlen(name) > 64) 377 return; 378 379 /* are we block or char? where should we live? */ 380 if(!strncmp(uevent->subsystem, "block", 5)) { 381 block = 1; 382 base = "/dev/block/"; 383 mkdir(base, 0755); 384 } else { 385 block = 0; 386 /* this should probably be configurable somehow */ 387 if(!strncmp(uevent->subsystem, "graphics", 8)) { 388 base = "/dev/graphics/"; 389 mkdir(base, 0755); 390 } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) { 391 base = "/dev/oncrpc/"; 392 mkdir(base, 0755); 393 } else if (!strncmp(uevent->subsystem, "adsp", 4)) { 394 base = "/dev/adsp/"; 395 mkdir(base, 0755); 396 } else if (!strncmp(uevent->subsystem, "msm_camera", 10)) { 397 base = "/dev/msm_camera/"; 398 mkdir(base, 0755); 399 } else if(!strncmp(uevent->subsystem, "input", 5)) { 400 base = "/dev/input/"; 401 mkdir(base, 0755); 402 } else if(!strncmp(uevent->subsystem, "mtd", 3)) { 403 base = "/dev/mtd/"; 404 mkdir(base, 0755); 405 } else if(!strncmp(uevent->subsystem, "sound", 5)) { 406 base = "/dev/snd/"; 407 mkdir(base, 0755); 408 } else if(!strncmp(uevent->subsystem, "misc", 4) && 409 !strncmp(name, "log_", 4)) { 410 base = "/dev/log/"; 411 mkdir(base, 0755); 412 name += 4; 413 } else 414 base = "/dev/"; 415 } 416 417 snprintf(devpath, sizeof(devpath), "%s%s", base, name); 418 419 if(!strcmp(uevent->action, "add")) { 420 make_device(devpath, block, uevent->major, uevent->minor); 421 return; 422 } 423 424 if(!strcmp(uevent->action, "remove")) { 425 unlink(devpath); 426 return; 427 } 428} 429 430static int load_firmware(int fw_fd, int loading_fd, int data_fd) 431{ 432 struct stat st; 433 long len_to_copy; 434 int ret = 0; 435 436 if(fstat(fw_fd, &st) < 0) 437 return -1; 438 len_to_copy = st.st_size; 439 440 write(loading_fd, "1", 1); /* start transfer */ 441 442 while (len_to_copy > 0) { 443 char buf[PAGE_SIZE]; 444 ssize_t nr; 445 446 nr = read(fw_fd, buf, sizeof(buf)); 447 if(!nr) 448 break; 449 if(nr < 0) { 450 ret = -1; 451 break; 452 } 453 454 len_to_copy -= nr; 455 while (nr > 0) { 456 ssize_t nw = 0; 457 458 nw = write(data_fd, buf + nw, nr); 459 if(nw <= 0) { 460 ret = -1; 461 goto out; 462 } 463 nr -= nw; 464 } 465 } 466 467out: 468 if(!ret) 469 write(loading_fd, "0", 1); /* successful end of transfer */ 470 else 471 write(loading_fd, "-1", 2); /* abort transfer */ 472 473 return ret; 474} 475 476static void process_firmware_event(struct uevent *uevent) 477{ 478 char *root, *loading, *data, *file; 479 int l, loading_fd, data_fd, fw_fd; 480 481 log_event_print("firmware event { '%s', '%s' }\n", 482 uevent->path, uevent->firmware); 483 484 l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path); 485 if (l == -1) 486 return; 487 488 l = asprintf(&loading, "%sloading", root); 489 if (l == -1) 490 goto root_free_out; 491 492 l = asprintf(&data, "%sdata", root); 493 if (l == -1) 494 goto loading_free_out; 495 496 l = asprintf(&file, FIRMWARE_DIR"/%s", uevent->firmware); 497 if (l == -1) 498 goto data_free_out; 499 500 loading_fd = open(loading, O_WRONLY); 501 if(loading_fd < 0) 502 goto file_free_out; 503 504 data_fd = open(data, O_WRONLY); 505 if(data_fd < 0) 506 goto loading_close_out; 507 508 fw_fd = open(file, O_RDONLY); 509 if(fw_fd < 0) 510 goto data_close_out; 511 512 if(!load_firmware(fw_fd, loading_fd, data_fd)) 513 log_event_print("firmware copy success { '%s', '%s' }\n", root, file); 514 else 515 log_event_print("firmware copy failure { '%s', '%s' }\n", root, file); 516 517 close(fw_fd); 518data_close_out: 519 close(data_fd); 520loading_close_out: 521 close(loading_fd); 522file_free_out: 523 free(file); 524data_free_out: 525 free(data); 526loading_free_out: 527 free(loading); 528root_free_out: 529 free(root); 530} 531 532static void handle_firmware_event(struct uevent *uevent) 533{ 534 pid_t pid; 535 536 if(strcmp(uevent->subsystem, "firmware")) 537 return; 538 539 if(strcmp(uevent->action, "add")) 540 return; 541 542 /* we fork, to avoid making large memory allocations in init proper */ 543 pid = fork(); 544 if (!pid) { 545 process_firmware_event(uevent); 546 exit(EXIT_SUCCESS); 547 } 548} 549 550#define UEVENT_MSG_LEN 1024 551void handle_device_fd(int fd) 552{ 553 char msg[UEVENT_MSG_LEN+2]; 554 int n; 555 556 while((n = recv(fd, msg, UEVENT_MSG_LEN, 0)) > 0) { 557 struct uevent uevent; 558 559 if(n == UEVENT_MSG_LEN) /* overflow -- discard */ 560 continue; 561 562 msg[n] = '\0'; 563 msg[n+1] = '\0'; 564 565 parse_event(msg, &uevent); 566 567 handle_device_event(&uevent); 568 handle_firmware_event(&uevent); 569 } 570} 571 572/* Coldboot walks parts of the /sys tree and pokes the uevent files 573** to cause the kernel to regenerate device add events that happened 574** before init's device manager was started 575** 576** We drain any pending events from the netlink socket every time 577** we poke another uevent file to make sure we don't overrun the 578** socket's buffer. 579*/ 580 581static void do_coldboot(int event_fd, DIR *d) 582{ 583 struct dirent *de; 584 int dfd, fd; 585 586 dfd = dirfd(d); 587 588 fd = openat(dfd, "uevent", O_WRONLY); 589 if(fd >= 0) { 590 write(fd, "add\n", 4); 591 close(fd); 592 handle_device_fd(event_fd); 593 } 594 595 while((de = readdir(d))) { 596 DIR *d2; 597 598 if(de->d_type != DT_DIR || de->d_name[0] == '.') 599 continue; 600 601 fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY); 602 if(fd < 0) 603 continue; 604 605 d2 = fdopendir(fd); 606 if(d2 == 0) 607 close(fd); 608 else { 609 do_coldboot(event_fd, d2); 610 closedir(d2); 611 } 612 } 613} 614 615static void coldboot(int event_fd, const char *path) 616{ 617 DIR *d = opendir(path); 618 if(d) { 619 do_coldboot(event_fd, d); 620 closedir(d); 621 } 622} 623 624int device_init(void) 625{ 626 suseconds_t t0, t1; 627 int fd; 628 629 fd = open_uevent_socket(); 630 if(fd < 0) 631 return -1; 632 633 fcntl(fd, F_SETFD, FD_CLOEXEC); 634 fcntl(fd, F_SETFL, O_NONBLOCK); 635 636 t0 = get_usecs(); 637 coldboot(fd, "/sys/class"); 638 coldboot(fd, "/sys/block"); 639 coldboot(fd, "/sys/devices"); 640 t1 = get_usecs(); 641 642 log_event_print("coldboot %ld uS\n", ((long) (t1 - t0))); 643 644 return fd; 645} 646