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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     char *secontext;
131 
132         /* upaths omit the "/sys" that paths in this list
133          * contain, so we add 4 when comparing...
134          */
135     list_for_each(node, &sys_perms) {
136         dp = &(node_to_item(node, struct perm_node, plist))->dp;
137         if (dp->prefix) {
138             if (strncmp(upath, dp->name + 4, strlen(dp->name + 4)))
139                 continue;
140         } else {
141             if (strcmp(upath, dp->name + 4))
142                 continue;
143         }
144 
145         if ((strlen(upath) + strlen(dp->attr) + 6) > sizeof(buf))
146             return;
147 
148         sprintf(buf,"/sys%s/%s", upath, dp->attr);
149         INFO("fixup %s %d %d 0%o\n", buf, dp->uid, dp->gid, dp->perm);
150         chown(buf, dp->uid, dp->gid);
151         chmod(buf, dp->perm);
152         if (sehandle) {
153             secontext = NULL;
154             selabel_lookup(sehandle, &secontext, buf, 0);
155             if (secontext) {
156                 setfilecon(buf, secontext);
157                 freecon(secontext);
158            }
159         }
160     }
161 }
162 
get_device_perm(const char * path,unsigned * uid,unsigned * gid)163 static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid)
164 {
165     mode_t perm;
166     struct listnode *node;
167     struct perm_node *perm_node;
168     struct perms_ *dp;
169 
170     /* search the perms list in reverse so that ueventd.$hardware can
171      * override ueventd.rc
172      */
173     list_for_each_reverse(node, &dev_perms) {
174         perm_node = node_to_item(node, struct perm_node, plist);
175         dp = &perm_node->dp;
176 
177         if (dp->prefix) {
178             if (strncmp(path, dp->name, strlen(dp->name)))
179                 continue;
180         } else {
181             if (strcmp(path, dp->name))
182                 continue;
183         }
184         *uid = dp->uid;
185         *gid = dp->gid;
186         return dp->perm;
187     }
188     /* Default if nothing found. */
189     *uid = 0;
190     *gid = 0;
191     return 0600;
192 }
193 
make_device(const char * path,const char * upath,int block,int major,int minor)194 static void make_device(const char *path,
195                         const char *upath,
196                         int block, int major, int minor)
197 {
198     unsigned uid;
199     unsigned gid;
200     mode_t mode;
201     dev_t dev;
202     char *secontext = NULL;
203 
204     mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR);
205 
206     if (sehandle) {
207         selabel_lookup(sehandle, &secontext, path, mode);
208         setfscreatecon(secontext);
209     }
210 
211     dev = makedev(major, minor);
212     /* Temporarily change egid to avoid race condition setting the gid of the
213      * device node. Unforunately changing the euid would prevent creation of
214      * some device nodes, so the uid has to be set with chown() and is still
215      * racy. Fixing the gid race at least fixed the issue with system_server
216      * opening dynamic input devices under the AID_INPUT gid. */
217     setegid(gid);
218     mknod(path, mode, dev);
219     chown(path, uid, -1);
220     setegid(AID_ROOT);
221 
222     if (secontext) {
223         freecon(secontext);
224         setfscreatecon(NULL);
225     }
226 }
227 
add_platform_device(const char * path)228 static void add_platform_device(const char *path)
229 {
230     int path_len = strlen(path);
231     struct listnode *node;
232     struct platform_node *bus;
233     const char *name = path;
234 
235     if (!strncmp(path, "/devices/", 9)) {
236         name += 9;
237         if (!strncmp(name, "platform/", 9))
238             name += 9;
239     }
240 
241     list_for_each_reverse(node, &platform_names) {
242         bus = node_to_item(node, struct platform_node, list);
243         if ((bus->path_len < path_len) &&
244                 (path[bus->path_len] == '/') &&
245                 !strncmp(path, bus->path, bus->path_len))
246             /* subdevice of an existing platform, ignore it */
247             return;
248     }
249 
250     INFO("adding platform device %s (%s)\n", name, path);
251 
252     bus = calloc(1, sizeof(struct platform_node));
253     bus->path = strdup(path);
254     bus->path_len = path_len;
255     bus->name = bus->path + (name - path);
256     list_add_tail(&platform_names, &bus->list);
257 }
258 
259 /*
260  * given a path that may start with a platform device, find the length of the
261  * platform device prefix.  If it doesn't start with a platform device, return
262  * 0.
263  */
find_platform_device(const char * path)264 static struct platform_node *find_platform_device(const char *path)
265 {
266     int path_len = strlen(path);
267     struct listnode *node;
268     struct platform_node *bus;
269 
270     list_for_each_reverse(node, &platform_names) {
271         bus = node_to_item(node, struct platform_node, list);
272         if ((bus->path_len < path_len) &&
273                 (path[bus->path_len] == '/') &&
274                 !strncmp(path, bus->path, bus->path_len))
275             return bus;
276     }
277 
278     return NULL;
279 }
280 
remove_platform_device(const char * path)281 static void remove_platform_device(const char *path)
282 {
283     struct listnode *node;
284     struct platform_node *bus;
285 
286     list_for_each_reverse(node, &platform_names) {
287         bus = node_to_item(node, struct platform_node, list);
288         if (!strcmp(path, bus->path)) {
289             INFO("removing platform device %s\n", bus->name);
290             free(bus->path);
291             list_remove(node);
292             free(bus);
293             return;
294         }
295     }
296 }
297 
298 #if LOG_UEVENTS
299 
get_usecs(void)300 static inline suseconds_t get_usecs(void)
301 {
302     struct timeval tv;
303     gettimeofday(&tv, 0);
304     return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec;
305 }
306 
307 #define log_event_print(x...) INFO(x)
308 
309 #else
310 
311 #define log_event_print(fmt, args...)   do { } while (0)
312 #define get_usecs()                     0
313 
314 #endif
315 
parse_event(const char * msg,struct uevent * uevent)316 static void parse_event(const char *msg, struct uevent *uevent)
317 {
318     uevent->action = "";
319     uevent->path = "";
320     uevent->subsystem = "";
321     uevent->firmware = "";
322     uevent->major = -1;
323     uevent->minor = -1;
324     uevent->partition_name = NULL;
325     uevent->partition_num = -1;
326     uevent->device_name = NULL;
327 
328         /* currently ignoring SEQNUM */
329     while(*msg) {
330         if(!strncmp(msg, "ACTION=", 7)) {
331             msg += 7;
332             uevent->action = msg;
333         } else if(!strncmp(msg, "DEVPATH=", 8)) {
334             msg += 8;
335             uevent->path = msg;
336         } else if(!strncmp(msg, "SUBSYSTEM=", 10)) {
337             msg += 10;
338             uevent->subsystem = msg;
339         } else if(!strncmp(msg, "FIRMWARE=", 9)) {
340             msg += 9;
341             uevent->firmware = msg;
342         } else if(!strncmp(msg, "MAJOR=", 6)) {
343             msg += 6;
344             uevent->major = atoi(msg);
345         } else if(!strncmp(msg, "MINOR=", 6)) {
346             msg += 6;
347             uevent->minor = atoi(msg);
348         } else if(!strncmp(msg, "PARTN=", 6)) {
349             msg += 6;
350             uevent->partition_num = atoi(msg);
351         } else if(!strncmp(msg, "PARTNAME=", 9)) {
352             msg += 9;
353             uevent->partition_name = msg;
354         } else if(!strncmp(msg, "DEVNAME=", 8)) {
355             msg += 8;
356             uevent->device_name = msg;
357         }
358 
359         /* advance to after the next \0 */
360         while(*msg++)
361             ;
362     }
363 
364     log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n",
365                     uevent->action, uevent->path, uevent->subsystem,
366                     uevent->firmware, uevent->major, uevent->minor);
367 }
368 
get_character_device_symlinks(struct uevent * uevent)369 static char **get_character_device_symlinks(struct uevent *uevent)
370 {
371     const char *parent;
372     char *slash;
373     char **links;
374     int link_num = 0;
375     int width;
376     struct platform_node *pdev;
377 
378     pdev = find_platform_device(uevent->path);
379     if (!pdev)
380         return NULL;
381 
382     links = malloc(sizeof(char *) * 2);
383     if (!links)
384         return NULL;
385     memset(links, 0, sizeof(char *) * 2);
386 
387     /* skip "/devices/platform/<driver>" */
388     parent = strchr(uevent->path + pdev->path_len, '/');
389     if (!*parent)
390         goto err;
391 
392     if (!strncmp(parent, "/usb", 4)) {
393         /* skip root hub name and device. use device interface */
394         while (*++parent && *parent != '/');
395         if (*parent)
396             while (*++parent && *parent != '/');
397         if (!*parent)
398             goto err;
399         slash = strchr(++parent, '/');
400         if (!slash)
401             goto err;
402         width = slash - parent;
403         if (width <= 0)
404             goto err;
405 
406         if (asprintf(&links[link_num], "/dev/usb/%s%.*s", uevent->subsystem, width, parent) > 0)
407             link_num++;
408         else
409             links[link_num] = NULL;
410         mkdir("/dev/usb", 0755);
411     }
412     else {
413         goto err;
414     }
415 
416     return links;
417 err:
418     free(links);
419     return NULL;
420 }
421 
parse_platform_block_device(struct uevent * uevent)422 static char **parse_platform_block_device(struct uevent *uevent)
423 {
424     const char *device;
425     struct platform_node *pdev;
426     char *slash;
427     int width;
428     char buf[256];
429     char link_path[256];
430     int fd;
431     int link_num = 0;
432     int ret;
433     char *p;
434     unsigned int size;
435     struct stat info;
436 
437     pdev = find_platform_device(uevent->path);
438     if (!pdev)
439         return NULL;
440     device = pdev->name;
441 
442     char **links = malloc(sizeof(char *) * 4);
443     if (!links)
444         return NULL;
445     memset(links, 0, sizeof(char *) * 4);
446 
447     INFO("found platform device %s\n", device);
448 
449     snprintf(link_path, sizeof(link_path), "/dev/block/platform/%s", device);
450 
451     if (uevent->partition_name) {
452         p = strdup(uevent->partition_name);
453         sanitize(p);
454         if (strcmp(uevent->partition_name, p))
455             NOTICE("Linking partition '%s' as '%s'\n", uevent->partition_name, p);
456         if (asprintf(&links[link_num], "%s/by-name/%s", link_path, p) > 0)
457             link_num++;
458         else
459             links[link_num] = NULL;
460         free(p);
461     }
462 
463     if (uevent->partition_num >= 0) {
464         if (asprintf(&links[link_num], "%s/by-num/p%d", link_path, uevent->partition_num) > 0)
465             link_num++;
466         else
467             links[link_num] = NULL;
468     }
469 
470     slash = strrchr(uevent->path, '/');
471     if (asprintf(&links[link_num], "%s/%s", link_path, slash + 1) > 0)
472         link_num++;
473     else
474         links[link_num] = NULL;
475 
476     return links;
477 }
478 
handle_device(const char * action,const char * devpath,const char * path,int block,int major,int minor,char ** links)479 static void handle_device(const char *action, const char *devpath,
480         const char *path, int block, int major, int minor, char **links)
481 {
482     int i;
483 
484     if(!strcmp(action, "add")) {
485         make_device(devpath, path, block, major, minor);
486         if (links) {
487             for (i = 0; links[i]; i++)
488                 make_link(devpath, links[i]);
489         }
490     }
491 
492     if(!strcmp(action, "remove")) {
493         if (links) {
494             for (i = 0; links[i]; i++)
495                 remove_link(devpath, links[i]);
496         }
497         unlink(devpath);
498     }
499 
500     if (links) {
501         for (i = 0; links[i]; i++)
502             free(links[i]);
503         free(links);
504     }
505 }
506 
handle_platform_device_event(struct uevent * uevent)507 static void handle_platform_device_event(struct uevent *uevent)
508 {
509     const char *path = uevent->path;
510 
511     if (!strcmp(uevent->action, "add"))
512         add_platform_device(path);
513     else if (!strcmp(uevent->action, "remove"))
514         remove_platform_device(path);
515 }
516 
parse_device_name(struct uevent * uevent,unsigned int len)517 static const char *parse_device_name(struct uevent *uevent, unsigned int len)
518 {
519     const char *name;
520 
521     /* if it's not a /dev device, nothing else to do */
522     if((uevent->major < 0) || (uevent->minor < 0))
523         return NULL;
524 
525     /* do we have a name? */
526     name = strrchr(uevent->path, '/');
527     if(!name)
528         return NULL;
529     name++;
530 
531     /* too-long names would overrun our buffer */
532     if(strlen(name) > len)
533         return NULL;
534 
535     return name;
536 }
537 
handle_block_device_event(struct uevent * uevent)538 static void handle_block_device_event(struct uevent *uevent)
539 {
540     const char *base = "/dev/block/";
541     const char *name;
542     char devpath[96];
543     char **links = NULL;
544 
545     name = parse_device_name(uevent, 64);
546     if (!name)
547         return;
548 
549     snprintf(devpath, sizeof(devpath), "%s%s", base, name);
550     make_dir(base, 0755);
551 
552     if (!strncmp(uevent->path, "/devices/", 9))
553         links = parse_platform_block_device(uevent);
554 
555     handle_device(uevent->action, devpath, uevent->path, 1,
556             uevent->major, uevent->minor, links);
557 }
558 
handle_generic_device_event(struct uevent * uevent)559 static void handle_generic_device_event(struct uevent *uevent)
560 {
561     char *base;
562     const char *name;
563     char devpath[96] = {0};
564     char **links = NULL;
565 
566     name = parse_device_name(uevent, 64);
567     if (!name)
568         return;
569 
570     if (!strncmp(uevent->subsystem, "usb", 3)) {
571          if (!strcmp(uevent->subsystem, "usb")) {
572             if (uevent->device_name) {
573                 /*
574                  * create device node provided by kernel if present
575                  * see drivers/base/core.c
576                  */
577                 char *p = devpath;
578                 snprintf(devpath, sizeof(devpath), "/dev/%s", uevent->device_name);
579                 /* skip leading /dev/ */
580                 p += 5;
581                 /* build directories */
582                 while (*p) {
583                     if (*p == '/') {
584                         *p = 0;
585                         make_dir(devpath, 0755);
586                         *p = '/';
587                     }
588                     p++;
589                 }
590              }
591              else {
592                  /* This imitates the file system that would be created
593                   * if we were using devfs instead.
594                   * Minors are broken up into groups of 128, starting at "001"
595                   */
596                  int bus_id = uevent->minor / 128 + 1;
597                  int device_id = uevent->minor % 128 + 1;
598                  /* build directories */
599                  make_dir("/dev/bus", 0755);
600                  make_dir("/dev/bus/usb", 0755);
601                  snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d", bus_id);
602                  make_dir(devpath, 0755);
603                  snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d/%03d", bus_id, device_id);
604              }
605          } else {
606              /* ignore other USB events */
607              return;
608          }
609      } else if (!strncmp(uevent->subsystem, "graphics", 8)) {
610          base = "/dev/graphics/";
611          make_dir(base, 0755);
612      } else if (!strncmp(uevent->subsystem, "drm", 3)) {
613          base = "/dev/dri/";
614          make_dir(base, 0755);
615      } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) {
616          base = "/dev/oncrpc/";
617          make_dir(base, 0755);
618      } else if (!strncmp(uevent->subsystem, "adsp", 4)) {
619          base = "/dev/adsp/";
620          make_dir(base, 0755);
621      } else if (!strncmp(uevent->subsystem, "msm_camera", 10)) {
622          base = "/dev/msm_camera/";
623          make_dir(base, 0755);
624      } else if(!strncmp(uevent->subsystem, "input", 5)) {
625          base = "/dev/input/";
626          make_dir(base, 0755);
627      } else if(!strncmp(uevent->subsystem, "mtd", 3)) {
628          base = "/dev/mtd/";
629          make_dir(base, 0755);
630      } else if(!strncmp(uevent->subsystem, "sound", 5)) {
631          base = "/dev/snd/";
632          make_dir(base, 0755);
633      } else if(!strncmp(uevent->subsystem, "misc", 4) &&
634                  !strncmp(name, "log_", 4)) {
635          base = "/dev/log/";
636          make_dir(base, 0755);
637          name += 4;
638      } else
639          base = "/dev/";
640      links = get_character_device_symlinks(uevent);
641 
642      if (!devpath[0])
643          snprintf(devpath, sizeof(devpath), "%s%s", base, name);
644 
645      handle_device(uevent->action, devpath, uevent->path, 0,
646              uevent->major, uevent->minor, links);
647 }
648 
handle_device_event(struct uevent * uevent)649 static void handle_device_event(struct uevent *uevent)
650 {
651     if (!strcmp(uevent->action,"add") || !strcmp(uevent->action, "change"))
652         fixup_sys_perms(uevent->path);
653 
654     if (!strncmp(uevent->subsystem, "block", 5)) {
655         handle_block_device_event(uevent);
656     } else if (!strncmp(uevent->subsystem, "platform", 8)) {
657         handle_platform_device_event(uevent);
658     } else {
659         handle_generic_device_event(uevent);
660     }
661 }
662 
load_firmware(int fw_fd,int loading_fd,int data_fd)663 static int load_firmware(int fw_fd, int loading_fd, int data_fd)
664 {
665     struct stat st;
666     long len_to_copy;
667     int ret = 0;
668 
669     if(fstat(fw_fd, &st) < 0)
670         return -1;
671     len_to_copy = st.st_size;
672 
673     write(loading_fd, "1", 1);  /* start transfer */
674 
675     while (len_to_copy > 0) {
676         char buf[PAGE_SIZE];
677         ssize_t nr;
678 
679         nr = read(fw_fd, buf, sizeof(buf));
680         if(!nr)
681             break;
682         if(nr < 0) {
683             ret = -1;
684             break;
685         }
686 
687         len_to_copy -= nr;
688         while (nr > 0) {
689             ssize_t nw = 0;
690 
691             nw = write(data_fd, buf + nw, nr);
692             if(nw <= 0) {
693                 ret = -1;
694                 goto out;
695             }
696             nr -= nw;
697         }
698     }
699 
700 out:
701     if(!ret)
702         write(loading_fd, "0", 1);  /* successful end of transfer */
703     else
704         write(loading_fd, "-1", 2); /* abort transfer */
705 
706     return ret;
707 }
708 
is_booting(void)709 static int is_booting(void)
710 {
711     return access("/dev/.booting", F_OK) == 0;
712 }
713 
process_firmware_event(struct uevent * uevent)714 static void process_firmware_event(struct uevent *uevent)
715 {
716     char *root, *loading, *data, *file1 = NULL, *file2 = NULL, *file3 = NULL;
717     int l, loading_fd, data_fd, fw_fd;
718     int booting = is_booting();
719 
720     INFO("firmware: loading '%s' for '%s'\n",
721          uevent->firmware, uevent->path);
722 
723     l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path);
724     if (l == -1)
725         return;
726 
727     l = asprintf(&loading, "%sloading", root);
728     if (l == -1)
729         goto root_free_out;
730 
731     l = asprintf(&data, "%sdata", root);
732     if (l == -1)
733         goto loading_free_out;
734 
735     l = asprintf(&file1, FIRMWARE_DIR1"/%s", uevent->firmware);
736     if (l == -1)
737         goto data_free_out;
738 
739     l = asprintf(&file2, FIRMWARE_DIR2"/%s", uevent->firmware);
740     if (l == -1)
741         goto data_free_out;
742 
743     l = asprintf(&file3, FIRMWARE_DIR3"/%s", uevent->firmware);
744     if (l == -1)
745         goto data_free_out;
746 
747     loading_fd = open(loading, O_WRONLY);
748     if(loading_fd < 0)
749         goto file_free_out;
750 
751     data_fd = open(data, O_WRONLY);
752     if(data_fd < 0)
753         goto loading_close_out;
754 
755 try_loading_again:
756     fw_fd = open(file1, O_RDONLY);
757     if(fw_fd < 0) {
758         fw_fd = open(file2, O_RDONLY);
759         if (fw_fd < 0) {
760             fw_fd = open(file3, O_RDONLY);
761             if (fw_fd < 0) {
762                 if (booting) {
763                         /* If we're not fully booted, we may be missing
764                          * filesystems needed for firmware, wait and retry.
765                          */
766                     usleep(100000);
767                     booting = is_booting();
768                     goto try_loading_again;
769                 }
770                 INFO("firmware: could not open '%s' %d\n", uevent->firmware, errno);
771                 write(loading_fd, "-1", 2);
772                 goto data_close_out;
773             }
774         }
775     }
776 
777     if(!load_firmware(fw_fd, loading_fd, data_fd))
778         INFO("firmware: copy success { '%s', '%s' }\n", root, uevent->firmware);
779     else
780         INFO("firmware: copy failure { '%s', '%s' }\n", root, uevent->firmware);
781 
782     close(fw_fd);
783 data_close_out:
784     close(data_fd);
785 loading_close_out:
786     close(loading_fd);
787 file_free_out:
788     free(file1);
789     free(file2);
790     free(file3);
791 data_free_out:
792     free(data);
793 loading_free_out:
794     free(loading);
795 root_free_out:
796     free(root);
797 }
798 
handle_firmware_event(struct uevent * uevent)799 static void handle_firmware_event(struct uevent *uevent)
800 {
801     pid_t pid;
802     int ret;
803 
804     if(strcmp(uevent->subsystem, "firmware"))
805         return;
806 
807     if(strcmp(uevent->action, "add"))
808         return;
809 
810     /* we fork, to avoid making large memory allocations in init proper */
811     pid = fork();
812     if (!pid) {
813         process_firmware_event(uevent);
814         exit(EXIT_SUCCESS);
815     }
816 }
817 
818 #define UEVENT_MSG_LEN  1024
handle_device_fd()819 void handle_device_fd()
820 {
821     char msg[UEVENT_MSG_LEN+2];
822     int n;
823     while ((n = uevent_kernel_multicast_recv(device_fd, msg, UEVENT_MSG_LEN)) > 0) {
824         if(n >= UEVENT_MSG_LEN)   /* overflow -- discard */
825             continue;
826 
827         msg[n] = '\0';
828         msg[n+1] = '\0';
829 
830         struct uevent uevent;
831         parse_event(msg, &uevent);
832 
833         handle_device_event(&uevent);
834         handle_firmware_event(&uevent);
835     }
836 }
837 
838 /* Coldboot walks parts of the /sys tree and pokes the uevent files
839 ** to cause the kernel to regenerate device add events that happened
840 ** before init's device manager was started
841 **
842 ** We drain any pending events from the netlink socket every time
843 ** we poke another uevent file to make sure we don't overrun the
844 ** socket's buffer.
845 */
846 
do_coldboot(DIR * d)847 static void do_coldboot(DIR *d)
848 {
849     struct dirent *de;
850     int dfd, fd;
851 
852     dfd = dirfd(d);
853 
854     fd = openat(dfd, "uevent", O_WRONLY);
855     if(fd >= 0) {
856         write(fd, "add\n", 4);
857         close(fd);
858         handle_device_fd();
859     }
860 
861     while((de = readdir(d))) {
862         DIR *d2;
863 
864         if(de->d_type != DT_DIR || de->d_name[0] == '.')
865             continue;
866 
867         fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY);
868         if(fd < 0)
869             continue;
870 
871         d2 = fdopendir(fd);
872         if(d2 == 0)
873             close(fd);
874         else {
875             do_coldboot(d2);
876             closedir(d2);
877         }
878     }
879 }
880 
coldboot(const char * path)881 static void coldboot(const char *path)
882 {
883     DIR *d = opendir(path);
884     if(d) {
885         do_coldboot(d);
886         closedir(d);
887     }
888 }
889 
device_init(void)890 void device_init(void)
891 {
892     suseconds_t t0, t1;
893     struct stat info;
894     int fd;
895 
896     sehandle = NULL;
897     if (is_selinux_enabled() > 0) {
898         sehandle = selinux_android_file_context_handle();
899     }
900 
901     /* is 256K enough? udev uses 16MB! */
902     device_fd = uevent_open_socket(256*1024, true);
903     if(device_fd < 0)
904         return;
905 
906     fcntl(device_fd, F_SETFD, FD_CLOEXEC);
907     fcntl(device_fd, F_SETFL, O_NONBLOCK);
908 
909     if (stat(coldboot_done, &info) < 0) {
910         t0 = get_usecs();
911         coldboot("/sys/class");
912         coldboot("/sys/block");
913         coldboot("/sys/devices");
914         t1 = get_usecs();
915         fd = open(coldboot_done, O_WRONLY|O_CREAT, 0000);
916         close(fd);
917         log_event_print("coldboot %ld uS\n", ((long) (t1 - t0)));
918     } else {
919         log_event_print("skipping coldboot, already done\n");
920     }
921 }
922 
get_device_fd()923 int get_device_fd()
924 {
925     return device_fd;
926 }
927