devices.c revision 4a762357d05fe2152dbe5d4b7085d01a5d4ccbf2
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/qemu_trace", 0666, AID_SYSTEM, AID_SYSTEM, 0 }, 130 { "/dev/qmi", 0640, AID_RADIO, AID_RADIO, 0 }, 131 { "/dev/qmi0", 0640, AID_RADIO, AID_RADIO, 0 }, 132 { "/dev/qmi1", 0640, AID_RADIO, AID_RADIO, 0 }, 133 { "/dev/qmi2", 0640, AID_RADIO, AID_RADIO, 0 }, 134 { NULL, 0, 0, 0, 0 }, 135}; 136 137/* devperms_partners list and perm_node are for hardware specific /dev entries */ 138struct perm_node { 139 struct perms_ dp; 140 struct listnode plist; 141}; 142list_declare(devperms_partners); 143 144/* 145 * Permission override when in emulator mode, must be parsed before 146 * system properties is initalized. 147 */ 148static int qemu_perm_count; 149static struct perms_ qemu_perms[MAX_QEMU_PERM + 1]; 150 151int add_devperms_partners(const char *name, mode_t perm, unsigned int uid, 152 unsigned int gid, unsigned short prefix) { 153 int size; 154 struct perm_node *node = malloc(sizeof (struct perm_node)); 155 if (!node) 156 return -ENOMEM; 157 158 size = strlen(name) + 1; 159 if ((node->dp.name = malloc(size)) == NULL) 160 return -ENOMEM; 161 162 memcpy(node->dp.name, name, size); 163 node->dp.perm = perm; 164 node->dp.uid = uid; 165 node->dp.gid = gid; 166 node->dp.prefix = prefix; 167 168 list_add_tail(&devperms_partners, &node->plist); 169 return 0; 170} 171 172void qemu_init(void) { 173 qemu_perm_count = 0; 174 memset(&qemu_perms, 0, sizeof(qemu_perms)); 175} 176 177static int qemu_perm(const char* name, mode_t perm, unsigned int uid, 178 unsigned int gid, unsigned short prefix) 179{ 180 char *buf; 181 if (qemu_perm_count == MAX_QEMU_PERM) 182 return -ENOSPC; 183 184 buf = malloc(strlen(name) + 1); 185 if (!buf) 186 return -errno; 187 188 strlcpy(buf, name, strlen(name) + 1); 189 qemu_perms[qemu_perm_count].name = buf; 190 qemu_perms[qemu_perm_count].perm = perm; 191 qemu_perms[qemu_perm_count].uid = uid; 192 qemu_perms[qemu_perm_count].gid = gid; 193 qemu_perms[qemu_perm_count].prefix = prefix; 194 195 qemu_perm_count++; 196 return 0; 197} 198 199/* Permission overrides for emulator that are parsed from /proc/cmdline. */ 200void qemu_cmdline(const char* name, const char *value) 201{ 202 char *buf; 203 if (!strcmp(name, "android.ril")) { 204 /* cmd line params currently assume /dev/ prefix */ 205 if (asprintf(&buf, CMDLINE_PREFIX"/%s", value) == -1) { 206 return; 207 } 208 INFO("nani- buf:: %s\n", buf); 209 qemu_perm(buf, 0660, AID_RADIO, AID_ROOT, 0); 210 } 211} 212 213static int get_device_perm_inner(struct perms_ *perms, const char *path, 214 unsigned *uid, unsigned *gid, mode_t *perm) 215{ 216 int i; 217 for(i = 0; perms[i].name; i++) { 218 219 if(perms[i].prefix) { 220 if(strncmp(path, perms[i].name, strlen(perms[i].name))) 221 continue; 222 } else { 223 if(strcmp(path, perms[i].name)) 224 continue; 225 } 226 *uid = perms[i].uid; 227 *gid = perms[i].gid; 228 *perm = perms[i].perm; 229 return 0; 230 } 231 return -1; 232} 233 234/* First checks for emulator specific permissions specified in /proc/cmdline. */ 235static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid) 236{ 237 mode_t perm; 238 239 if (get_device_perm_inner(qemu_perms, path, uid, gid, &perm) == 0) { 240 return perm; 241 } else if (get_device_perm_inner(devperms, path, uid, gid, &perm) == 0) { 242 return perm; 243 } else { 244 struct listnode *node; 245 struct perm_node *perm_node; 246 struct perms_ *dp; 247 248 /* Check partners list. */ 249 list_for_each(node, &devperms_partners) { 250 perm_node = node_to_item(node, struct perm_node, plist); 251 dp = &perm_node->dp; 252 253 if (dp->prefix) { 254 if (strncmp(path, dp->name, strlen(dp->name))) 255 continue; 256 } else { 257 if (strcmp(path, dp->name)) 258 continue; 259 } 260 /* Found perm in partner list. */ 261 *uid = dp->uid; 262 *gid = dp->gid; 263 return dp->perm; 264 } 265 /* Default if nothing found. */ 266 *uid = 0; 267 *gid = 0; 268 return 0600; 269 } 270} 271 272static void make_device(const char *path, int block, int major, int minor) 273{ 274 unsigned uid; 275 unsigned gid; 276 mode_t mode; 277 dev_t dev; 278 279 if(major > 255 || minor > 255) 280 return; 281 282 mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR); 283 dev = (major << 8) | minor; 284 mknod(path, mode, dev); 285 chown(path, uid, gid); 286} 287 288#ifdef LOG_UEVENTS 289 290static inline suseconds_t get_usecs(void) 291{ 292 struct timeval tv; 293 gettimeofday(&tv, 0); 294 return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec; 295} 296 297#define log_event_print(x...) INFO(x) 298 299#else 300 301#define log_event_print(fmt, args...) do { } while (0) 302#define get_usecs() 0 303 304#endif 305 306static void parse_event(const char *msg, struct uevent *uevent) 307{ 308 uevent->action = ""; 309 uevent->path = ""; 310 uevent->subsystem = ""; 311 uevent->firmware = ""; 312 uevent->major = -1; 313 uevent->minor = -1; 314 315 /* currently ignoring SEQNUM */ 316 while(*msg) { 317 if(!strncmp(msg, "ACTION=", 7)) { 318 msg += 7; 319 uevent->action = msg; 320 } else if(!strncmp(msg, "DEVPATH=", 8)) { 321 msg += 8; 322 uevent->path = msg; 323 } else if(!strncmp(msg, "SUBSYSTEM=", 10)) { 324 msg += 10; 325 uevent->subsystem = msg; 326 } else if(!strncmp(msg, "FIRMWARE=", 9)) { 327 msg += 9; 328 uevent->firmware = msg; 329 } else if(!strncmp(msg, "MAJOR=", 6)) { 330 msg += 6; 331 uevent->major = atoi(msg); 332 } else if(!strncmp(msg, "MINOR=", 6)) { 333 msg += 6; 334 uevent->minor = atoi(msg); 335 } 336 337 /* advance to after the next \0 */ 338 while(*msg++) 339 ; 340 } 341 342 log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n", 343 uevent->action, uevent->path, uevent->subsystem, 344 uevent->firmware, uevent->major, uevent->minor); 345} 346 347static void handle_device_event(struct uevent *uevent) 348{ 349 char devpath[96]; 350 char *base, *name; 351 int block; 352 353 /* if it's not a /dev device, nothing to do */ 354 if((uevent->major < 0) || (uevent->minor < 0)) 355 return; 356 357 /* do we have a name? */ 358 name = strrchr(uevent->path, '/'); 359 if(!name) 360 return; 361 name++; 362 363 /* too-long names would overrun our buffer */ 364 if(strlen(name) > 64) 365 return; 366 367 /* are we block or char? where should we live? */ 368 if(!strncmp(uevent->subsystem, "block", 5)) { 369 block = 1; 370 base = "/dev/block/"; 371 mkdir(base, 0755); 372 } else { 373 block = 0; 374 /* this should probably be configurable somehow */ 375 if(!strncmp(uevent->subsystem, "graphics", 8)) { 376 base = "/dev/graphics/"; 377 mkdir(base, 0755); 378 } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) { 379 base = "/dev/oncrpc/"; 380 mkdir(base, 0755); 381 } else if (!strncmp(uevent->subsystem, "adsp", 4)) { 382 base = "/dev/adsp/"; 383 mkdir(base, 0755); 384 } else if(!strncmp(uevent->subsystem, "input", 5)) { 385 base = "/dev/input/"; 386 mkdir(base, 0755); 387 } else if(!strncmp(uevent->subsystem, "mtd", 3)) { 388 base = "/dev/mtd/"; 389 mkdir(base, 0755); 390 } else if(!strncmp(uevent->subsystem, "misc", 4) && 391 !strncmp(name, "log_", 4)) { 392 base = "/dev/log/"; 393 mkdir(base, 0755); 394 name += 4; 395 } else 396 base = "/dev/"; 397 } 398 399 snprintf(devpath, sizeof(devpath), "%s%s", base, name); 400 401 if(!strcmp(uevent->action, "add")) { 402 make_device(devpath, block, uevent->major, uevent->minor); 403 return; 404 } 405 406 if(!strcmp(uevent->action, "remove")) { 407 unlink(devpath); 408 return; 409 } 410} 411 412static int load_firmware(int fw_fd, int loading_fd, int data_fd) 413{ 414 struct stat st; 415 long len_to_copy; 416 int ret = 0; 417 418 if(fstat(fw_fd, &st) < 0) 419 return -1; 420 len_to_copy = st.st_size; 421 422 write(loading_fd, "1", 1); /* start transfer */ 423 424 while (len_to_copy > 0) { 425 char buf[PAGE_SIZE]; 426 ssize_t nr; 427 428 nr = read(fw_fd, buf, sizeof(buf)); 429 if(!nr) 430 break; 431 if(nr < 0) { 432 ret = -1; 433 break; 434 } 435 436 len_to_copy -= nr; 437 while (nr > 0) { 438 ssize_t nw = 0; 439 440 nw = write(data_fd, buf + nw, nr); 441 if(nw <= 0) { 442 ret = -1; 443 goto out; 444 } 445 nr -= nw; 446 } 447 } 448 449out: 450 if(!ret) 451 write(loading_fd, "0", 1); /* successful end of transfer */ 452 else 453 write(loading_fd, "-1", 2); /* abort transfer */ 454 455 return ret; 456} 457 458static void process_firmware_event(struct uevent *uevent) 459{ 460 char *root, *loading, *data, *file; 461 int l, loading_fd, data_fd, fw_fd; 462 463 log_event_print("firmware event { '%s', '%s' }\n", 464 uevent->path, uevent->firmware); 465 466 l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path); 467 if (l == -1) 468 return; 469 470 l = asprintf(&loading, "%sloading", root); 471 if (l == -1) 472 goto root_free_out; 473 474 l = asprintf(&data, "%sdata", root); 475 if (l == -1) 476 goto loading_free_out; 477 478 l = asprintf(&file, FIRMWARE_DIR"/%s", uevent->firmware); 479 if (l == -1) 480 goto data_free_out; 481 482 loading_fd = open(loading, O_WRONLY); 483 if(loading_fd < 0) 484 goto file_free_out; 485 486 data_fd = open(data, O_WRONLY); 487 if(data_fd < 0) 488 goto loading_close_out; 489 490 fw_fd = open(file, O_RDONLY); 491 if(fw_fd < 0) 492 goto data_close_out; 493 494 if(!load_firmware(fw_fd, loading_fd, data_fd)) 495 log_event_print("firmware copy success { '%s', '%s' }\n", root, file); 496 else 497 log_event_print("firmware copy failure { '%s', '%s' }\n", root, file); 498 499 close(fw_fd); 500data_close_out: 501 close(data_fd); 502loading_close_out: 503 close(loading_fd); 504file_free_out: 505 free(file); 506data_free_out: 507 free(data); 508loading_free_out: 509 free(loading); 510root_free_out: 511 free(root); 512} 513 514static void handle_firmware_event(struct uevent *uevent) 515{ 516 pid_t pid; 517 518 if(strcmp(uevent->subsystem, "firmware")) 519 return; 520 521 if(strcmp(uevent->action, "add")) 522 return; 523 524 /* we fork, to avoid making large memory allocations in init proper */ 525 pid = fork(); 526 if (!pid) { 527 process_firmware_event(uevent); 528 exit(EXIT_SUCCESS); 529 } 530} 531 532#define UEVENT_MSG_LEN 1024 533void handle_device_fd(int fd) 534{ 535 char msg[UEVENT_MSG_LEN+2]; 536 int n; 537 538 while((n = recv(fd, msg, UEVENT_MSG_LEN, 0)) > 0) { 539 struct uevent uevent; 540 541 if(n == UEVENT_MSG_LEN) /* overflow -- discard */ 542 continue; 543 544 msg[n] = '\0'; 545 msg[n+1] = '\0'; 546 547 parse_event(msg, &uevent); 548 549 handle_device_event(&uevent); 550 handle_firmware_event(&uevent); 551 } 552} 553 554/* Coldboot walks parts of the /sys tree and pokes the uevent files 555** to cause the kernel to regenerate device add events that happened 556** before init's device manager was started 557** 558** We drain any pending events from the netlink socket every time 559** we poke another uevent file to make sure we don't overrun the 560** socket's buffer. 561*/ 562 563static void do_coldboot(int event_fd, DIR *d) 564{ 565 struct dirent *de; 566 int dfd, fd; 567 568 dfd = dirfd(d); 569 570 fd = openat(dfd, "uevent", O_WRONLY); 571 if(fd >= 0) { 572 write(fd, "add\n", 4); 573 close(fd); 574 handle_device_fd(event_fd); 575 } 576 577 while((de = readdir(d))) { 578 DIR *d2; 579 580 if(de->d_type != DT_DIR || de->d_name[0] == '.') 581 continue; 582 583 fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY); 584 if(fd < 0) 585 continue; 586 587 d2 = fdopendir(fd); 588 if(d2 == 0) 589 close(fd); 590 else { 591 do_coldboot(event_fd, d2); 592 closedir(d2); 593 } 594 } 595} 596 597static void coldboot(int event_fd, const char *path) 598{ 599 DIR *d = opendir(path); 600 if(d) { 601 do_coldboot(event_fd, d); 602 closedir(d); 603 } 604} 605 606int device_init(void) 607{ 608 suseconds_t t0, t1; 609 int fd; 610 611 fd = open_uevent_socket(); 612 if(fd < 0) 613 return -1; 614 615 fcntl(fd, F_SETFD, FD_CLOEXEC); 616 fcntl(fd, F_SETFL, O_NONBLOCK); 617 618 t0 = get_usecs(); 619 coldboot(fd, "/sys/class"); 620 coldboot(fd, "/sys/block"); 621 coldboot(fd, "/sys/devices"); 622 t1 = get_usecs(); 623 624 log_event_print("coldboot %ld uS\n", ((long) (t1 - t0))); 625 626 return fd; 627} 628