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