devices.c revision c603720aed304fdd36a5815f81eb22bd4d9968b7 
1/*
2 * Copyright (C) 2007-2014 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 <fnmatch.h>
19#include <stddef.h>
20#include <stdio.h>
21#include <stdlib.h>
22#include <sys/stat.h>
23#include <sys/types.h>
24
25#include <fcntl.h>
26#include <dirent.h>
27#include <unistd.h>
28#include <string.h>
29
30#include <sys/socket.h>
31#include <sys/un.h>
32#include <linux/netlink.h>
33
34#include <selinux/selinux.h>
35#include <selinux/label.h>
36#include <selinux/android.h>
37#include <selinux/avc.h>
38
39#include <private/android_filesystem_config.h>
40#include <sys/time.h>
41#include <sys/wait.h>
42
43#include <cutils/list.h>
44#include <cutils/uevent.h>
45
46#include "devices.h"
47#include "ueventd_parser.h"
48#include "util.h"
49#include "log.h"
50
51#define UNUSED __attribute__((__unused__))
52
53#define SYSFS_PREFIX    "/sys"
54#define FIRMWARE_DIR1   "/etc/firmware"
55#define FIRMWARE_DIR2   "/vendor/firmware"
56#define FIRMWARE_DIR3   "/firmware/image"
57
58extern struct selabel_handle *sehandle;
59
60static int device_fd = -1;
61
62struct uevent {
63    const char *action;
64    const char *path;
65    const char *subsystem;
66    const char *firmware;
67    const char *partition_name;
68    const char *device_name;
69    int partition_num;
70    int major;
71    int minor;
72};
73
74struct perms_ {
75    char *name;
76    char *attr;
77    mode_t perm;
78    unsigned int uid;
79    unsigned int gid;
80    unsigned short prefix;
81    unsigned short wildcard;
82};
83
84struct perm_node {
85    struct perms_ dp;
86    struct listnode plist;
87};
88
89struct platform_node {
90    char *name;
91    char *path;
92    int path_len;
93    struct listnode list;
94};
95
96static list_declare(sys_perms);
97static list_declare(dev_perms);
98static list_declare(platform_names);
99
100int add_dev_perms(const char *name, const char *attr,
101                  mode_t perm, unsigned int uid, unsigned int gid,
102                  unsigned short prefix,
103                  unsigned short wildcard) {
104    struct perm_node *node = calloc(1, sizeof(*node));
105    if (!node)
106        return -ENOMEM;
107
108    node->dp.name = strdup(name);
109    if (!node->dp.name)
110        return -ENOMEM;
111
112    if (attr) {
113        node->dp.attr = strdup(attr);
114        if (!node->dp.attr)
115            return -ENOMEM;
116    }
117
118    node->dp.perm = perm;
119    node->dp.uid = uid;
120    node->dp.gid = gid;
121    node->dp.prefix = prefix;
122    node->dp.wildcard = wildcard;
123
124    if (attr)
125        list_add_tail(&sys_perms, &node->plist);
126    else
127        list_add_tail(&dev_perms, &node->plist);
128
129    return 0;
130}
131
132void fixup_sys_perms(const char *upath)
133{
134    char buf[512];
135    struct listnode *node;
136    struct perms_ *dp;
137    char *secontext;
138
139        /* upaths omit the "/sys" that paths in this list
140         * contain, so we add 4 when comparing...
141         */
142    list_for_each(node, &sys_perms) {
143        dp = &(node_to_item(node, struct perm_node, plist))->dp;
144        if (dp->prefix) {
145            if (strncmp(upath, dp->name + 4, strlen(dp->name + 4)))
146                continue;
147        } else if (dp->wildcard) {
148            if (fnmatch(dp->name + 4, upath, FNM_PATHNAME) != 0)
149                continue;
150        } else {
151            if (strcmp(upath, dp->name + 4))
152                continue;
153        }
154
155        if ((strlen(upath) + strlen(dp->attr) + 6) > sizeof(buf))
156            return;
157
158        sprintf(buf,"/sys%s/%s", upath, dp->attr);
159        INFO("fixup %s %d %d 0%o\n", buf, dp->uid, dp->gid, dp->perm);
160        chown(buf, dp->uid, dp->gid);
161        chmod(buf, dp->perm);
162        if (sehandle) {
163            secontext = NULL;
164            selabel_lookup(sehandle, &secontext, buf, 0);
165            if (secontext) {
166                setfilecon(buf, secontext);
167                freecon(secontext);
168           }
169        }
170    }
171}
172
173static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid)
174{
175    mode_t perm;
176    struct listnode *node;
177    struct perm_node *perm_node;
178    struct perms_ *dp;
179
180    /* search the perms list in reverse so that ueventd.$hardware can
181     * override ueventd.rc
182     */
183    list_for_each_reverse(node, &dev_perms) {
184        perm_node = node_to_item(node, struct perm_node, plist);
185        dp = &perm_node->dp;
186
187        if (dp->prefix) {
188            if (strncmp(path, dp->name, strlen(dp->name)))
189                continue;
190        } else if (dp->wildcard) {
191            if (fnmatch(dp->name, path, FNM_PATHNAME) != 0)
192                continue;
193        } else {
194            if (strcmp(path, dp->name))
195                continue;
196        }
197        *uid = dp->uid;
198        *gid = dp->gid;
199        return dp->perm;
200    }
201    /* Default if nothing found. */
202    *uid = 0;
203    *gid = 0;
204    return 0600;
205}
206
207static void make_device(const char *path,
208                        const char *upath UNUSED,
209                        int block, int major, int minor,
210                        const char **links)
211{
212    unsigned uid;
213    unsigned gid;
214    mode_t mode;
215    dev_t dev;
216    char *secontext = NULL;
217
218    mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR);
219
220    if (sehandle) {
221        selabel_lookup_best_match(sehandle, &secontext, path, links, mode);
222        setfscreatecon(secontext);
223    }
224
225    dev = makedev(major, minor);
226    /* Temporarily change egid to avoid race condition setting the gid of the
227     * device node. Unforunately changing the euid would prevent creation of
228     * some device nodes, so the uid has to be set with chown() and is still
229     * racy. Fixing the gid race at least fixed the issue with system_server
230     * opening dynamic input devices under the AID_INPUT gid. */
231    setegid(gid);
232    mknod(path, mode, dev);
233    chown(path, uid, -1);
234    setegid(AID_ROOT);
235
236    if (secontext) {
237        freecon(secontext);
238        setfscreatecon(NULL);
239    }
240}
241
242static void add_platform_device(const char *path)
243{
244    int path_len = strlen(path);
245    struct listnode *node;
246    struct platform_node *bus;
247    const char *name = path;
248
249    if (!strncmp(path, "/devices/", 9)) {
250        name += 9;
251        if (!strncmp(name, "platform/", 9))
252            name += 9;
253    }
254
255    list_for_each_reverse(node, &platform_names) {
256        bus = node_to_item(node, struct platform_node, list);
257        if ((bus->path_len < path_len) &&
258                (path[bus->path_len] == '/') &&
259                !strncmp(path, bus->path, bus->path_len))
260            /* subdevice of an existing platform, ignore it */
261            return;
262    }
263
264    INFO("adding platform device %s (%s)\n", name, path);
265
266    bus = calloc(1, sizeof(struct platform_node));
267    bus->path = strdup(path);
268    bus->path_len = path_len;
269    bus->name = bus->path + (name - path);
270    list_add_tail(&platform_names, &bus->list);
271}
272
273/*
274 * given a path that may start with a platform device, find the length of the
275 * platform device prefix.  If it doesn't start with a platform device, return
276 * 0.
277 */
278static struct platform_node *find_platform_device(const char *path)
279{
280    int path_len = strlen(path);
281    struct listnode *node;
282    struct platform_node *bus;
283
284    list_for_each_reverse(node, &platform_names) {
285        bus = node_to_item(node, struct platform_node, list);
286        if ((bus->path_len < path_len) &&
287                (path[bus->path_len] == '/') &&
288                !strncmp(path, bus->path, bus->path_len))
289            return bus;
290    }
291
292    return NULL;
293}
294
295static void remove_platform_device(const char *path)
296{
297    struct listnode *node;
298    struct platform_node *bus;
299
300    list_for_each_reverse(node, &platform_names) {
301        bus = node_to_item(node, struct platform_node, list);
302        if (!strcmp(path, bus->path)) {
303            INFO("removing platform device %s\n", bus->name);
304            free(bus->path);
305            list_remove(node);
306            free(bus);
307            return;
308        }
309    }
310}
311
312/* Given a path that may start with a PCI device, populate the supplied buffer
313 * with the PCI domain/bus number and the peripheral ID and return 0.
314 * If it doesn't start with a PCI device, or there is some error, return -1 */
315static int find_pci_device_prefix(const char *path, char *buf, ssize_t buf_sz)
316{
317    const char *start, *end;
318
319    if (strncmp(path, "/devices/pci", 12))
320        return -1;
321
322    /* Beginning of the prefix is the initial "pci" after "/devices/" */
323    start = path + 9;
324
325    /* End of the prefix is two path '/' later, capturing the domain/bus number
326     * and the peripheral ID. Example: pci0000:00/0000:00:1f.2 */
327    end = strchr(start, '/');
328    if (!end)
329        return -1;
330    end = strchr(end + 1, '/');
331    if (!end)
332        return -1;
333
334    /* Make sure we have enough room for the string plus null terminator */
335    if (end - start + 1 > buf_sz)
336        return -1;
337
338    strncpy(buf, start, end - start);
339    buf[end - start] = '\0';
340    return 0;
341}
342
343#if LOG_UEVENTS
344
345static inline suseconds_t get_usecs(void)
346{
347    struct timeval tv;
348    gettimeofday(&tv, 0);
349    return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec;
350}
351
352#define log_event_print(x...) INFO(x)
353
354#else
355
356#define log_event_print(fmt, args...)   do { } while (0)
357#define get_usecs()                     0
358
359#endif
360
361static void parse_event(const char *msg, struct uevent *uevent)
362{
363    uevent->action = "";
364    uevent->path = "";
365    uevent->subsystem = "";
366    uevent->firmware = "";
367    uevent->major = -1;
368    uevent->minor = -1;
369    uevent->partition_name = NULL;
370    uevent->partition_num = -1;
371    uevent->device_name = NULL;
372
373        /* currently ignoring SEQNUM */
374    while(*msg) {
375        if(!strncmp(msg, "ACTION=", 7)) {
376            msg += 7;
377            uevent->action = msg;
378        } else if(!strncmp(msg, "DEVPATH=", 8)) {
379            msg += 8;
380            uevent->path = msg;
381        } else if(!strncmp(msg, "SUBSYSTEM=", 10)) {
382            msg += 10;
383            uevent->subsystem = msg;
384        } else if(!strncmp(msg, "FIRMWARE=", 9)) {
385            msg += 9;
386            uevent->firmware = msg;
387        } else if(!strncmp(msg, "MAJOR=", 6)) {
388            msg += 6;
389            uevent->major = atoi(msg);
390        } else if(!strncmp(msg, "MINOR=", 6)) {
391            msg += 6;
392            uevent->minor = atoi(msg);
393        } else if(!strncmp(msg, "PARTN=", 6)) {
394            msg += 6;
395            uevent->partition_num = atoi(msg);
396        } else if(!strncmp(msg, "PARTNAME=", 9)) {
397            msg += 9;
398            uevent->partition_name = msg;
399        } else if(!strncmp(msg, "DEVNAME=", 8)) {
400            msg += 8;
401            uevent->device_name = msg;
402        }
403
404        /* advance to after the next \0 */
405        while(*msg++)
406            ;
407    }
408
409    log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n",
410                    uevent->action, uevent->path, uevent->subsystem,
411                    uevent->firmware, uevent->major, uevent->minor);
412}
413
414static char **get_character_device_symlinks(struct uevent *uevent)
415{
416    const char *parent;
417    char *slash;
418    char **links;
419    int link_num = 0;
420    int width;
421    struct platform_node *pdev;
422
423    pdev = find_platform_device(uevent->path);
424    if (!pdev)
425        return NULL;
426
427    links = malloc(sizeof(char *) * 2);
428    if (!links)
429        return NULL;
430    memset(links, 0, sizeof(char *) * 2);
431
432    /* skip "/devices/platform/<driver>" */
433    parent = strchr(uevent->path + pdev->path_len, '/');
434    if (!*parent)
435        goto err;
436
437    if (!strncmp(parent, "/usb", 4)) {
438        /* skip root hub name and device. use device interface */
439        while (*++parent && *parent != '/');
440        if (*parent)
441            while (*++parent && *parent != '/');
442        if (!*parent)
443            goto err;
444        slash = strchr(++parent, '/');
445        if (!slash)
446            goto err;
447        width = slash - parent;
448        if (width <= 0)
449            goto err;
450
451        if (asprintf(&links[link_num], "/dev/usb/%s%.*s", uevent->subsystem, width, parent) > 0)
452            link_num++;
453        else
454            links[link_num] = NULL;
455        mkdir("/dev/usb", 0755);
456    }
457    else {
458        goto err;
459    }
460
461    return links;
462err:
463    free(links);
464    return NULL;
465}
466
467static char **get_block_device_symlinks(struct uevent *uevent)
468{
469    const char *device;
470    struct platform_node *pdev;
471    char *slash;
472    const char *type;
473    int width;
474    char buf[256];
475    char link_path[256];
476    int fd;
477    int link_num = 0;
478    int ret;
479    char *p;
480    unsigned int size;
481    struct stat info;
482
483    pdev = find_platform_device(uevent->path);
484    if (pdev) {
485        device = pdev->name;
486        type = "platform";
487    } else if (!find_pci_device_prefix(uevent->path, buf, sizeof(buf))) {
488        device = buf;
489        type = "pci";
490    } else {
491        return NULL;
492    }
493
494    char **links = malloc(sizeof(char *) * 4);
495    if (!links)
496        return NULL;
497    memset(links, 0, sizeof(char *) * 4);
498
499    INFO("found %s device %s\n", type, device);
500
501    snprintf(link_path, sizeof(link_path), "/dev/block/%s/%s", type, device);
502
503    if (uevent->partition_name) {
504        p = strdup(uevent->partition_name);
505        sanitize(p);
506        if (strcmp(uevent->partition_name, p))
507            NOTICE("Linking partition '%s' as '%s'\n", uevent->partition_name, p);
508        if (asprintf(&links[link_num], "%s/by-name/%s", link_path, p) > 0)
509            link_num++;
510        else
511            links[link_num] = NULL;
512        free(p);
513    }
514
515    if (uevent->partition_num >= 0) {
516        if (asprintf(&links[link_num], "%s/by-num/p%d", link_path, uevent->partition_num) > 0)
517            link_num++;
518        else
519            links[link_num] = NULL;
520    }
521
522    slash = strrchr(uevent->path, '/');
523    if (asprintf(&links[link_num], "%s/%s", link_path, slash + 1) > 0)
524        link_num++;
525    else
526        links[link_num] = NULL;
527
528    return links;
529}
530
531static void handle_device(const char *action, const char *devpath,
532        const char *path, int block, int major, int minor, char **links)
533{
534    int i;
535
536    if(!strcmp(action, "add")) {
537        make_device(devpath, path, block, major, minor, (const char **)links);
538        if (links) {
539            for (i = 0; links[i]; i++)
540                make_link(devpath, links[i]);
541        }
542    }
543
544    if(!strcmp(action, "remove")) {
545        if (links) {
546            for (i = 0; links[i]; i++)
547                remove_link(devpath, links[i]);
548        }
549        unlink(devpath);
550    }
551
552    if (links) {
553        for (i = 0; links[i]; i++)
554            free(links[i]);
555        free(links);
556    }
557}
558
559static void handle_platform_device_event(struct uevent *uevent)
560{
561    const char *path = uevent->path;
562
563    if (!strcmp(uevent->action, "add"))
564        add_platform_device(path);
565    else if (!strcmp(uevent->action, "remove"))
566        remove_platform_device(path);
567}
568
569static const char *parse_device_name(struct uevent *uevent, unsigned int len)
570{
571    const char *name;
572
573    /* if it's not a /dev device, nothing else to do */
574    if((uevent->major < 0) || (uevent->minor < 0))
575        return NULL;
576
577    /* do we have a name? */
578    name = strrchr(uevent->path, '/');
579    if(!name)
580        return NULL;
581    name++;
582
583    /* too-long names would overrun our buffer */
584    if(strlen(name) > len) {
585        ERROR("DEVPATH=%s exceeds %u-character limit on filename; ignoring event\n",
586                name, len);
587        return NULL;
588    }
589
590    return name;
591}
592
593static void handle_block_device_event(struct uevent *uevent)
594{
595    const char *base = "/dev/block/";
596    const char *name;
597    char devpath[96];
598    char **links = NULL;
599
600    name = parse_device_name(uevent, 64);
601    if (!name)
602        return;
603
604    snprintf(devpath, sizeof(devpath), "%s%s", base, name);
605    make_dir(base, 0755);
606
607    if (!strncmp(uevent->path, "/devices/", 9))
608        links = get_block_device_symlinks(uevent);
609
610    handle_device(uevent->action, devpath, uevent->path, 1,
611            uevent->major, uevent->minor, links);
612}
613
614#define DEVPATH_LEN 96
615
616static bool assemble_devpath(char *devpath, const char *dirname,
617        const char *devname)
618{
619    int s = snprintf(devpath, DEVPATH_LEN, "%s/%s", dirname, devname);
620    if (s < 0) {
621        ERROR("failed to assemble device path (%s); ignoring event\n",
622                strerror(errno));
623        return false;
624    } else if (s >= DEVPATH_LEN) {
625        ERROR("%s/%s exceeds %u-character limit on path; ignoring event\n",
626                dirname, devname, DEVPATH_LEN);
627        return false;
628    }
629    return true;
630}
631
632static void mkdir_recursive_for_devpath(const char *devpath)
633{
634    char dir[DEVPATH_LEN];
635    char *slash;
636
637    strcpy(dir, devpath);
638    slash = strrchr(dir, '/');
639    *slash = '\0';
640    mkdir_recursive(dir, 0755);
641}
642
643static inline void __attribute__((__deprecated__)) kernel_logger()
644{
645    INFO("kernel logger is deprecated\n");
646}
647
648static void handle_generic_device_event(struct uevent *uevent)
649{
650    char *base;
651    const char *name;
652    char devpath[DEVPATH_LEN] = {0};
653    char **links = NULL;
654
655    name = parse_device_name(uevent, 64);
656    if (!name)
657        return;
658
659    struct ueventd_subsystem *subsystem =
660            ueventd_subsystem_find_by_name(uevent->subsystem);
661
662    if (subsystem) {
663        const char *devname;
664
665        switch (subsystem->devname_src) {
666        case DEVNAME_UEVENT_DEVNAME:
667            devname = uevent->device_name;
668            break;
669
670        case DEVNAME_UEVENT_DEVPATH:
671            devname = name;
672            break;
673
674        default:
675            ERROR("%s subsystem's devpath option is not set; ignoring event\n",
676                    uevent->subsystem);
677            return;
678        }
679
680        if (!assemble_devpath(devpath, subsystem->dirname, devname))
681            return;
682        mkdir_recursive_for_devpath(devpath);
683    } else if (!strncmp(uevent->subsystem, "usb", 3)) {
684         if (!strcmp(uevent->subsystem, "usb")) {
685            if (uevent->device_name) {
686                if (!assemble_devpath(devpath, "/dev", uevent->device_name))
687                    return;
688                mkdir_recursive_for_devpath(devpath);
689             }
690             else {
691                 /* This imitates the file system that would be created
692                  * if we were using devfs instead.
693                  * Minors are broken up into groups of 128, starting at "001"
694                  */
695                 int bus_id = uevent->minor / 128 + 1;
696                 int device_id = uevent->minor % 128 + 1;
697                 /* build directories */
698                 make_dir("/dev/bus", 0755);
699                 make_dir("/dev/bus/usb", 0755);
700                 snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d", bus_id);
701                 make_dir(devpath, 0755);
702                 snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d/%03d", bus_id, device_id);
703             }
704         } else {
705             /* ignore other USB events */
706             return;
707         }
708     } else if (!strncmp(uevent->subsystem, "graphics", 8)) {
709         base = "/dev/graphics/";
710         make_dir(base, 0755);
711     } else if (!strncmp(uevent->subsystem, "drm", 3)) {
712         base = "/dev/dri/";
713         make_dir(base, 0755);
714     } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) {
715         base = "/dev/oncrpc/";
716         make_dir(base, 0755);
717     } else if (!strncmp(uevent->subsystem, "adsp", 4)) {
718         base = "/dev/adsp/";
719         make_dir(base, 0755);
720     } else if (!strncmp(uevent->subsystem, "msm_camera", 10)) {
721         base = "/dev/msm_camera/";
722         make_dir(base, 0755);
723     } else if(!strncmp(uevent->subsystem, "input", 5)) {
724         base = "/dev/input/";
725         make_dir(base, 0755);
726     } else if(!strncmp(uevent->subsystem, "mtd", 3)) {
727         base = "/dev/mtd/";
728         make_dir(base, 0755);
729     } else if(!strncmp(uevent->subsystem, "sound", 5)) {
730         base = "/dev/snd/";
731         make_dir(base, 0755);
732     } else if(!strncmp(uevent->subsystem, "misc", 4) &&
733                 !strncmp(name, "log_", 4)) {
734         kernel_logger();
735         base = "/dev/log/";
736         make_dir(base, 0755);
737         name += 4;
738     } else
739         base = "/dev/";
740     links = get_character_device_symlinks(uevent);
741
742     if (!devpath[0])
743         snprintf(devpath, sizeof(devpath), "%s%s", base, name);
744
745     handle_device(uevent->action, devpath, uevent->path, 0,
746             uevent->major, uevent->minor, links);
747}
748
749static void handle_device_event(struct uevent *uevent)
750{
751    if (!strcmp(uevent->action,"add") || !strcmp(uevent->action, "change") || !strcmp(uevent->action, "online"))
752        fixup_sys_perms(uevent->path);
753
754    if (!strncmp(uevent->subsystem, "block", 5)) {
755        handle_block_device_event(uevent);
756    } else if (!strncmp(uevent->subsystem, "platform", 8)) {
757        handle_platform_device_event(uevent);
758    } else {
759        handle_generic_device_event(uevent);
760    }
761}
762
763static int load_firmware(int fw_fd, int loading_fd, int data_fd)
764{
765    struct stat st;
766    long len_to_copy;
767    int ret = 0;
768
769    if(fstat(fw_fd, &st) < 0)
770        return -1;
771    len_to_copy = st.st_size;
772
773    write(loading_fd, "1", 1);  /* start transfer */
774
775    while (len_to_copy > 0) {
776        char buf[PAGE_SIZE];
777        ssize_t nr;
778
779        nr = read(fw_fd, buf, sizeof(buf));
780        if(!nr)
781            break;
782        if(nr < 0) {
783            ret = -1;
784            break;
785        }
786
787        len_to_copy -= nr;
788        while (nr > 0) {
789            ssize_t nw = 0;
790
791            nw = write(data_fd, buf + nw, nr);
792            if(nw <= 0) {
793                ret = -1;
794                goto out;
795            }
796            nr -= nw;
797        }
798    }
799
800out:
801    if(!ret)
802        write(loading_fd, "0", 1);  /* successful end of transfer */
803    else
804        write(loading_fd, "-1", 2); /* abort transfer */
805
806    return ret;
807}
808
809static int is_booting(void)
810{
811    return access("/dev/.booting", F_OK) == 0;
812}
813
814static void process_firmware_event(struct uevent *uevent)
815{
816    char *root, *loading, *data, *file1 = NULL, *file2 = NULL, *file3 = NULL;
817    int l, loading_fd, data_fd, fw_fd;
818    int booting = is_booting();
819
820    INFO("firmware: loading '%s' for '%s'\n",
821         uevent->firmware, uevent->path);
822
823    l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path);
824    if (l == -1)
825        return;
826
827    l = asprintf(&loading, "%sloading", root);
828    if (l == -1)
829        goto root_free_out;
830
831    l = asprintf(&data, "%sdata", root);
832    if (l == -1)
833        goto loading_free_out;
834
835    l = asprintf(&file1, FIRMWARE_DIR1"/%s", uevent->firmware);
836    if (l == -1)
837        goto data_free_out;
838
839    l = asprintf(&file2, FIRMWARE_DIR2"/%s", uevent->firmware);
840    if (l == -1)
841        goto data_free_out;
842
843    l = asprintf(&file3, FIRMWARE_DIR3"/%s", uevent->firmware);
844    if (l == -1)
845        goto data_free_out;
846
847    loading_fd = open(loading, O_WRONLY);
848    if(loading_fd < 0)
849        goto file_free_out;
850
851    data_fd = open(data, O_WRONLY);
852    if(data_fd < 0)
853        goto loading_close_out;
854
855try_loading_again:
856    fw_fd = open(file1, O_RDONLY);
857    if(fw_fd < 0) {
858        fw_fd = open(file2, O_RDONLY);
859        if (fw_fd < 0) {
860            fw_fd = open(file3, O_RDONLY);
861            if (fw_fd < 0) {
862                if (booting) {
863                        /* If we're not fully booted, we may be missing
864                         * filesystems needed for firmware, wait and retry.
865                         */
866                    usleep(100000);
867                    booting = is_booting();
868                    goto try_loading_again;
869                }
870                INFO("firmware: could not open '%s' %d\n", uevent->firmware, errno);
871                write(loading_fd, "-1", 2);
872                goto data_close_out;
873            }
874        }
875    }
876
877    if(!load_firmware(fw_fd, loading_fd, data_fd))
878        INFO("firmware: copy success { '%s', '%s' }\n", root, uevent->firmware);
879    else
880        INFO("firmware: copy failure { '%s', '%s' }\n", root, uevent->firmware);
881
882    close(fw_fd);
883data_close_out:
884    close(data_fd);
885loading_close_out:
886    close(loading_fd);
887file_free_out:
888    free(file1);
889    free(file2);
890    free(file3);
891data_free_out:
892    free(data);
893loading_free_out:
894    free(loading);
895root_free_out:
896    free(root);
897}
898
899static void handle_firmware_event(struct uevent *uevent)
900{
901    pid_t pid;
902    int ret;
903
904    if(strcmp(uevent->subsystem, "firmware"))
905        return;
906
907    if(strcmp(uevent->action, "add"))
908        return;
909
910    /* we fork, to avoid making large memory allocations in init proper */
911    pid = fork();
912    if (!pid) {
913        process_firmware_event(uevent);
914        exit(EXIT_SUCCESS);
915    }
916}
917
918#define UEVENT_MSG_LEN  2048
919void handle_device_fd()
920{
921    char msg[UEVENT_MSG_LEN+2];
922    int n;
923    while ((n = uevent_kernel_multicast_recv(device_fd, msg, UEVENT_MSG_LEN)) > 0) {
924        if(n >= UEVENT_MSG_LEN)   /* overflow -- discard */
925            continue;
926
927        msg[n] = '\0';
928        msg[n+1] = '\0';
929
930        struct uevent uevent;
931        parse_event(msg, &uevent);
932
933        if (sehandle && selinux_status_updated() > 0) {
934            struct selabel_handle *sehandle2;
935            sehandle2 = selinux_android_file_context_handle();
936            if (sehandle2) {
937                selabel_close(sehandle);
938                sehandle = sehandle2;
939            }
940        }
941
942        handle_device_event(&uevent);
943        handle_firmware_event(&uevent);
944    }
945}
946
947/* Coldboot walks parts of the /sys tree and pokes the uevent files
948** to cause the kernel to regenerate device add events that happened
949** before init's device manager was started
950**
951** We drain any pending events from the netlink socket every time
952** we poke another uevent file to make sure we don't overrun the
953** socket's buffer.
954*/
955
956static void do_coldboot(DIR *d)
957{
958    struct dirent *de;
959    int dfd, fd;
960
961    dfd = dirfd(d);
962
963    fd = openat(dfd, "uevent", O_WRONLY);
964    if(fd >= 0) {
965        write(fd, "add\n", 4);
966        close(fd);
967        handle_device_fd();
968    }
969
970    while((de = readdir(d))) {
971        DIR *d2;
972
973        if(de->d_type != DT_DIR || de->d_name[0] == '.')
974            continue;
975
976        fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY);
977        if(fd < 0)
978            continue;
979
980        d2 = fdopendir(fd);
981        if(d2 == 0)
982            close(fd);
983        else {
984            do_coldboot(d2);
985            closedir(d2);
986        }
987    }
988}
989
990static void coldboot(const char *path)
991{
992    DIR *d = opendir(path);
993    if(d) {
994        do_coldboot(d);
995        closedir(d);
996    }
997}
998
999void device_init(void)
1000{
1001    suseconds_t t0, t1;
1002    struct stat info;
1003    int fd;
1004
1005    sehandle = NULL;
1006    if (is_selinux_enabled() > 0) {
1007        sehandle = selinux_android_file_context_handle();
1008        selinux_status_open(true);
1009    }
1010
1011    /* is 256K enough? udev uses 16MB! */
1012    device_fd = uevent_open_socket(256*1024, true);
1013    if(device_fd < 0)
1014        return;
1015
1016    fcntl(device_fd, F_SETFD, FD_CLOEXEC);
1017    fcntl(device_fd, F_SETFL, O_NONBLOCK);
1018
1019    if (stat(coldboot_done, &info) < 0) {
1020        t0 = get_usecs();
1021        coldboot("/sys/class");
1022        coldboot("/sys/block");
1023        coldboot("/sys/devices");
1024        t1 = get_usecs();
1025        fd = open(coldboot_done, O_WRONLY|O_CREAT, 0000);
1026        close(fd);
1027        log_event_print("coldboot %ld uS\n", ((long) (t1 - t0)));
1028    } else {
1029        log_event_print("skipping coldboot, already done\n");
1030    }
1031}
1032
1033int get_device_fd()
1034{
1035    return device_fd;
1036}
1037