devices.c revision 065694b32e481a50e57a793d61181494fbf6ef04
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 /* the msm hw3d client device node is world writable/readable. */ 99 { "/dev/msm_hw3dc", 0666, AID_ROOT, AID_ROOT, 0 }, 100 101 /* gpu driver for adreno200 is globally accessible */ 102 { "/dev/kgsl", 0666, AID_ROOT, AID_ROOT, 0 }, 103 104 /* these should not be world writable */ 105 { "/dev/diag", 0660, AID_RADIO, AID_RADIO, 0 }, 106 { "/dev/diag_arm9", 0660, AID_RADIO, AID_RADIO, 0 }, 107 { "/dev/android_adb", 0660, AID_ADB, AID_ADB, 0 }, 108 { "/dev/android_adb_enable", 0660, AID_ADB, AID_ADB, 0 }, 109 { "/dev/ttyMSM0", 0600, AID_BLUETOOTH, AID_BLUETOOTH, 0 }, 110 { "/dev/ttyHS0", 0600, AID_BLUETOOTH, AID_BLUETOOTH, 0 }, 111 { "/dev/uinput", 0660, AID_SYSTEM, AID_BLUETOOTH, 0 }, 112 { "/dev/alarm", 0664, AID_SYSTEM, AID_RADIO, 0 }, 113 { "/dev/tty0", 0660, AID_ROOT, AID_SYSTEM, 0 }, 114 { "/dev/graphics/", 0660, AID_ROOT, AID_GRAPHICS, 1 }, 115 { "/dev/msm_hw3dm", 0660, AID_SYSTEM, AID_GRAPHICS, 0 }, 116 { "/dev/input/", 0660, AID_ROOT, AID_INPUT, 1 }, 117 { "/dev/eac", 0660, AID_ROOT, AID_AUDIO, 0 }, 118 { "/dev/cam", 0660, AID_ROOT, AID_CAMERA, 0 }, 119 { "/dev/pmem", 0660, AID_SYSTEM, AID_GRAPHICS, 0 }, 120 { "/dev/pmem_adsp", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 121 { "/dev/pmem_camera", 0660, AID_SYSTEM, AID_CAMERA, 1 }, 122 { "/dev/oncrpc/", 0660, AID_ROOT, AID_SYSTEM, 1 }, 123 { "/dev/adsp/", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 124 { "/dev/mt9t013", 0660, AID_SYSTEM, AID_SYSTEM, 0 }, 125 { "/dev/msm_camera/", 0660, AID_SYSTEM, AID_SYSTEM, 1 }, 126 { "/dev/akm8976_daemon",0640, AID_COMPASS, AID_SYSTEM, 0 }, 127 { "/dev/akm8976_aot", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 128 { "/dev/akm8973_daemon",0640, AID_COMPASS, AID_SYSTEM, 0 }, 129 { "/dev/akm8973_aot", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 130 { "/dev/bma150", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 131 { "/dev/cm3602", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 132 { "/dev/akm8976_pffd", 0640, AID_COMPASS, AID_SYSTEM, 0 }, 133 { "/dev/lightsensor", 0640, AID_SYSTEM, AID_SYSTEM, 0 }, 134 { "/dev/msm_pcm_out", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 135 { "/dev/msm_pcm_in", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 136 { "/dev/msm_pcm_ctl", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 137 { "/dev/msm_snd", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 138 { "/dev/msm_mp3", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 139 { "/dev/audience_a1026", 0660, AID_SYSTEM, AID_AUDIO, 1 }, 140 { "/dev/msm_audpre", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 141 { "/dev/msm_audio_ctl", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 142 { "/dev/htc-acoustic", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 143 { "/dev/vdec", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 144 { "/dev/q6venc", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 145 { "/dev/snd/dsp", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 146 { "/dev/snd/dsp1", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 147 { "/dev/snd/mixer", 0660, AID_SYSTEM, AID_AUDIO, 0 }, 148 { "/dev/smd0", 0640, AID_RADIO, AID_RADIO, 0 }, 149 { "/dev/qemu_trace", 0666, AID_SYSTEM, AID_SYSTEM, 0 }, 150 { "/dev/qmi", 0640, AID_RADIO, AID_RADIO, 0 }, 151 { "/dev/qmi0", 0640, AID_RADIO, AID_RADIO, 0 }, 152 { "/dev/qmi1", 0640, AID_RADIO, AID_RADIO, 0 }, 153 { "/dev/qmi2", 0640, AID_RADIO, AID_RADIO, 0 }, 154 /* CDMA radio interface MUX */ 155 { "/dev/ts0710mux", 0640, AID_RADIO, AID_RADIO, 1 }, 156 { "/dev/ppp", 0660, AID_RADIO, AID_VPN, 0 }, 157 { "/dev/tun", 0640, AID_VPN, AID_VPN, 0 }, 158 { NULL, 0, 0, 0, 0 }, 159}; 160 161/* devperms_partners list and perm_node are for hardware specific /dev entries */ 162struct perm_node { 163 struct perms_ dp; 164 struct listnode plist; 165}; 166list_declare(devperms_partners); 167 168/* 169 * Permission override when in emulator mode, must be parsed before 170 * system properties is initalized. 171 */ 172static int qemu_perm_count; 173static struct perms_ qemu_perms[MAX_QEMU_PERM + 1]; 174 175int add_devperms_partners(const char *name, mode_t perm, unsigned int uid, 176 unsigned int gid, unsigned short prefix) { 177 int size; 178 struct perm_node *node = malloc(sizeof (struct perm_node)); 179 if (!node) 180 return -ENOMEM; 181 182 size = strlen(name) + 1; 183 if ((node->dp.name = malloc(size)) == NULL) 184 return -ENOMEM; 185 186 memcpy(node->dp.name, name, size); 187 node->dp.perm = perm; 188 node->dp.uid = uid; 189 node->dp.gid = gid; 190 node->dp.prefix = prefix; 191 192 list_add_tail(&devperms_partners, &node->plist); 193 return 0; 194} 195 196void qemu_init(void) { 197 qemu_perm_count = 0; 198 memset(&qemu_perms, 0, sizeof(qemu_perms)); 199} 200 201static int qemu_perm(const char* name, mode_t perm, unsigned int uid, 202 unsigned int gid, unsigned short prefix) 203{ 204 char *buf; 205 if (qemu_perm_count == MAX_QEMU_PERM) 206 return -ENOSPC; 207 208 buf = malloc(strlen(name) + 1); 209 if (!buf) 210 return -errno; 211 212 strlcpy(buf, name, strlen(name) + 1); 213 qemu_perms[qemu_perm_count].name = buf; 214 qemu_perms[qemu_perm_count].perm = perm; 215 qemu_perms[qemu_perm_count].uid = uid; 216 qemu_perms[qemu_perm_count].gid = gid; 217 qemu_perms[qemu_perm_count].prefix = prefix; 218 219 qemu_perm_count++; 220 return 0; 221} 222 223/* Permission overrides for emulator that are parsed from /proc/cmdline. */ 224void qemu_cmdline(const char* name, const char *value) 225{ 226 char *buf; 227 if (!strcmp(name, "android.ril")) { 228 /* cmd line params currently assume /dev/ prefix */ 229 if (asprintf(&buf, CMDLINE_PREFIX"/%s", value) == -1) { 230 return; 231 } 232 INFO("nani- buf:: %s\n", buf); 233 qemu_perm(buf, 0660, AID_RADIO, AID_ROOT, 0); 234 } 235} 236 237static int get_device_perm_inner(struct perms_ *perms, const char *path, 238 unsigned *uid, unsigned *gid, mode_t *perm) 239{ 240 int i; 241 for(i = 0; perms[i].name; i++) { 242 243 if(perms[i].prefix) { 244 if(strncmp(path, perms[i].name, strlen(perms[i].name))) 245 continue; 246 } else { 247 if(strcmp(path, perms[i].name)) 248 continue; 249 } 250 *uid = perms[i].uid; 251 *gid = perms[i].gid; 252 *perm = perms[i].perm; 253 return 0; 254 } 255 return -1; 256} 257 258/* First checks for emulator specific permissions specified in /proc/cmdline. */ 259static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid) 260{ 261 mode_t perm; 262 263 if (get_device_perm_inner(qemu_perms, path, uid, gid, &perm) == 0) { 264 return perm; 265 } else if (get_device_perm_inner(devperms, path, uid, gid, &perm) == 0) { 266 return perm; 267 } else { 268 struct listnode *node; 269 struct perm_node *perm_node; 270 struct perms_ *dp; 271 272 /* Check partners list. */ 273 list_for_each(node, &devperms_partners) { 274 perm_node = node_to_item(node, struct perm_node, plist); 275 dp = &perm_node->dp; 276 277 if (dp->prefix) { 278 if (strncmp(path, dp->name, strlen(dp->name))) 279 continue; 280 } else { 281 if (strcmp(path, dp->name)) 282 continue; 283 } 284 /* Found perm in partner list. */ 285 *uid = dp->uid; 286 *gid = dp->gid; 287 return dp->perm; 288 } 289 /* Default if nothing found. */ 290 *uid = 0; 291 *gid = 0; 292 return 0600; 293 } 294} 295 296static void make_device(const char *path, int block, int major, int minor) 297{ 298 unsigned uid; 299 unsigned gid; 300 mode_t mode; 301 dev_t dev; 302 303 if(major > 255 || minor > 255) 304 return; 305 306 mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR); 307 dev = (major << 8) | minor; 308 mknod(path, mode, dev); 309 chown(path, uid, gid); 310} 311 312#ifdef LOG_UEVENTS 313 314static inline suseconds_t get_usecs(void) 315{ 316 struct timeval tv; 317 gettimeofday(&tv, 0); 318 return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec; 319} 320 321#define log_event_print(x...) INFO(x) 322 323#else 324 325#define log_event_print(fmt, args...) do { } while (0) 326#define get_usecs() 0 327 328#endif 329 330static void parse_event(const char *msg, struct uevent *uevent) 331{ 332 uevent->action = ""; 333 uevent->path = ""; 334 uevent->subsystem = ""; 335 uevent->firmware = ""; 336 uevent->major = -1; 337 uevent->minor = -1; 338 339 /* currently ignoring SEQNUM */ 340 while(*msg) { 341 if(!strncmp(msg, "ACTION=", 7)) { 342 msg += 7; 343 uevent->action = msg; 344 } else if(!strncmp(msg, "DEVPATH=", 8)) { 345 msg += 8; 346 uevent->path = msg; 347 } else if(!strncmp(msg, "SUBSYSTEM=", 10)) { 348 msg += 10; 349 uevent->subsystem = msg; 350 } else if(!strncmp(msg, "FIRMWARE=", 9)) { 351 msg += 9; 352 uevent->firmware = msg; 353 } else if(!strncmp(msg, "MAJOR=", 6)) { 354 msg += 6; 355 uevent->major = atoi(msg); 356 } else if(!strncmp(msg, "MINOR=", 6)) { 357 msg += 6; 358 uevent->minor = atoi(msg); 359 } 360 361 /* advance to after the next \0 */ 362 while(*msg++) 363 ; 364 } 365 366 log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n", 367 uevent->action, uevent->path, uevent->subsystem, 368 uevent->firmware, uevent->major, uevent->minor); 369} 370 371static void handle_device_event(struct uevent *uevent) 372{ 373 char devpath[96]; 374 char *base, *name; 375 int block; 376 377 /* if it's not a /dev device, nothing to do */ 378 if((uevent->major < 0) || (uevent->minor < 0)) 379 return; 380 381 /* do we have a name? */ 382 name = strrchr(uevent->path, '/'); 383 if(!name) 384 return; 385 name++; 386 387 /* too-long names would overrun our buffer */ 388 if(strlen(name) > 64) 389 return; 390 391 /* are we block or char? where should we live? */ 392 if(!strncmp(uevent->subsystem, "block", 5)) { 393 block = 1; 394 base = "/dev/block/"; 395 mkdir(base, 0755); 396 } else { 397 block = 0; 398 /* this should probably be configurable somehow */ 399 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 snprintf(devpath, sizeof(devpath), "%s%s", base, name); 430 431 if(!strcmp(uevent->action, "add")) { 432 make_device(devpath, block, uevent->major, uevent->minor); 433 return; 434 } 435 436 if(!strcmp(uevent->action, "remove")) { 437 unlink(devpath); 438 return; 439 } 440} 441 442static int load_firmware(int fw_fd, int loading_fd, int data_fd) 443{ 444 struct stat st; 445 long len_to_copy; 446 int ret = 0; 447 448 if(fstat(fw_fd, &st) < 0) 449 return -1; 450 len_to_copy = st.st_size; 451 452 write(loading_fd, "1", 1); /* start transfer */ 453 454 while (len_to_copy > 0) { 455 char buf[PAGE_SIZE]; 456 ssize_t nr; 457 458 nr = read(fw_fd, buf, sizeof(buf)); 459 if(!nr) 460 break; 461 if(nr < 0) { 462 ret = -1; 463 break; 464 } 465 466 len_to_copy -= nr; 467 while (nr > 0) { 468 ssize_t nw = 0; 469 470 nw = write(data_fd, buf + nw, nr); 471 if(nw <= 0) { 472 ret = -1; 473 goto out; 474 } 475 nr -= nw; 476 } 477 } 478 479out: 480 if(!ret) 481 write(loading_fd, "0", 1); /* successful end of transfer */ 482 else 483 write(loading_fd, "-1", 2); /* abort transfer */ 484 485 return ret; 486} 487 488static void process_firmware_event(struct uevent *uevent) 489{ 490 char *root, *loading, *data, *file; 491 int l, loading_fd, data_fd, fw_fd; 492 493 log_event_print("firmware event { '%s', '%s' }\n", 494 uevent->path, uevent->firmware); 495 496 l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path); 497 if (l == -1) 498 return; 499 500 l = asprintf(&loading, "%sloading", root); 501 if (l == -1) 502 goto root_free_out; 503 504 l = asprintf(&data, "%sdata", root); 505 if (l == -1) 506 goto loading_free_out; 507 508 l = asprintf(&file, FIRMWARE_DIR"/%s", uevent->firmware); 509 if (l == -1) 510 goto data_free_out; 511 512 loading_fd = open(loading, O_WRONLY); 513 if(loading_fd < 0) 514 goto file_free_out; 515 516 data_fd = open(data, O_WRONLY); 517 if(data_fd < 0) 518 goto loading_close_out; 519 520 fw_fd = open(file, O_RDONLY); 521 if(fw_fd < 0) 522 goto data_close_out; 523 524 if(!load_firmware(fw_fd, loading_fd, data_fd)) 525 log_event_print("firmware copy success { '%s', '%s' }\n", root, file); 526 else 527 log_event_print("firmware copy failure { '%s', '%s' }\n", root, file); 528 529 close(fw_fd); 530data_close_out: 531 close(data_fd); 532loading_close_out: 533 close(loading_fd); 534file_free_out: 535 free(file); 536data_free_out: 537 free(data); 538loading_free_out: 539 free(loading); 540root_free_out: 541 free(root); 542} 543 544static void handle_firmware_event(struct uevent *uevent) 545{ 546 pid_t pid; 547 548 if(strcmp(uevent->subsystem, "firmware")) 549 return; 550 551 if(strcmp(uevent->action, "add")) 552 return; 553 554 /* we fork, to avoid making large memory allocations in init proper */ 555 pid = fork(); 556 if (!pid) { 557 process_firmware_event(uevent); 558 exit(EXIT_SUCCESS); 559 } 560} 561 562#define UEVENT_MSG_LEN 1024 563void handle_device_fd(int fd) 564{ 565 char msg[UEVENT_MSG_LEN+2]; 566 int n; 567 568 while((n = recv(fd, msg, UEVENT_MSG_LEN, 0)) > 0) { 569 struct uevent uevent; 570 571 if(n == UEVENT_MSG_LEN) /* overflow -- discard */ 572 continue; 573 574 msg[n] = '\0'; 575 msg[n+1] = '\0'; 576 577 parse_event(msg, &uevent); 578 579 handle_device_event(&uevent); 580 handle_firmware_event(&uevent); 581 } 582} 583 584/* Coldboot walks parts of the /sys tree and pokes the uevent files 585** to cause the kernel to regenerate device add events that happened 586** before init's device manager was started 587** 588** We drain any pending events from the netlink socket every time 589** we poke another uevent file to make sure we don't overrun the 590** socket's buffer. 591*/ 592 593static void do_coldboot(int event_fd, DIR *d) 594{ 595 struct dirent *de; 596 int dfd, fd; 597 598 dfd = dirfd(d); 599 600 fd = openat(dfd, "uevent", O_WRONLY); 601 if(fd >= 0) { 602 write(fd, "add\n", 4); 603 close(fd); 604 handle_device_fd(event_fd); 605 } 606 607 while((de = readdir(d))) { 608 DIR *d2; 609 610 if(de->d_type != DT_DIR || de->d_name[0] == '.') 611 continue; 612 613 fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY); 614 if(fd < 0) 615 continue; 616 617 d2 = fdopendir(fd); 618 if(d2 == 0) 619 close(fd); 620 else { 621 do_coldboot(event_fd, d2); 622 closedir(d2); 623 } 624 } 625} 626 627static void coldboot(int event_fd, const char *path) 628{ 629 DIR *d = opendir(path); 630 if(d) { 631 do_coldboot(event_fd, d); 632 closedir(d); 633 } 634} 635 636int device_init(void) 637{ 638 suseconds_t t0, t1; 639 int fd; 640 641 fd = open_uevent_socket(); 642 if(fd < 0) 643 return -1; 644 645 fcntl(fd, F_SETFD, FD_CLOEXEC); 646 fcntl(fd, F_SETFL, O_NONBLOCK); 647 648 t0 = get_usecs(); 649 coldboot(fd, "/sys/class"); 650 coldboot(fd, "/sys/block"); 651 coldboot(fd, "/sys/devices"); 652 t1 = get_usecs(); 653 654 log_event_print("coldboot %ld uS\n", ((long) (t1 - t0))); 655 656 return fd; 657} 658