devices.c revision e6f8d45da8c61d67dc9fdc1cec53f40594043817 
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#ifdef HAVE_SELINUX
34#include <selinux/selinux.h>
35#include <selinux/label.h>
36#endif
37
38#include <private/android_filesystem_config.h>
39#include <sys/time.h>
40#include <asm/page.h>
41#include <sys/wait.h>
42
43#include <cutils/list.h>
44#include <cutils/uevent.h>
45
46#include "devices.h"
47#include "util.h"
48#include "log.h"
49
50#define SYSFS_PREFIX    "/sys"
51#define FIRMWARE_DIR1   "/etc/firmware"
52#define FIRMWARE_DIR2   "/vendor/firmware"
53
54#ifdef HAVE_SELINUX
55static struct selabel_handle *sehandle;
56#endif
57
58static int device_fd = -1;
59
60struct uevent {
61    const char *action;
62    const char *path;
63    const char *subsystem;
64    const char *firmware;
65    const char *partition_name;
66    const char *device_name;
67    int partition_num;
68    int major;
69    int minor;
70};
71
72struct perms_ {
73    char *name;
74    char *attr;
75    mode_t perm;
76    unsigned int uid;
77    unsigned int gid;
78    unsigned short prefix;
79};
80
81struct perm_node {
82    struct perms_ dp;
83    struct listnode plist;
84};
85
86struct platform_node {
87    char *name;
88    int name_len;
89    struct listnode list;
90};
91
92static list_declare(sys_perms);
93static list_declare(dev_perms);
94static list_declare(platform_names);
95
96int add_dev_perms(const char *name, const char *attr,
97                  mode_t perm, unsigned int uid, unsigned int gid,
98                  unsigned short prefix) {
99    struct perm_node *node = calloc(1, sizeof(*node));
100    if (!node)
101        return -ENOMEM;
102
103    node->dp.name = strdup(name);
104    if (!node->dp.name)
105        return -ENOMEM;
106
107    if (attr) {
108        node->dp.attr = strdup(attr);
109        if (!node->dp.attr)
110            return -ENOMEM;
111    }
112
113    node->dp.perm = perm;
114    node->dp.uid = uid;
115    node->dp.gid = gid;
116    node->dp.prefix = prefix;
117
118    if (attr)
119        list_add_tail(&sys_perms, &node->plist);
120    else
121        list_add_tail(&dev_perms, &node->plist);
122
123    return 0;
124}
125
126void fixup_sys_perms(const char *upath)
127{
128    char buf[512];
129    struct listnode *node;
130    struct perms_ *dp;
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    }
153}
154
155static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid)
156{
157    mode_t perm;
158    struct listnode *node;
159    struct perm_node *perm_node;
160    struct perms_ *dp;
161
162    /* search the perms list in reverse so that ueventd.$hardware can
163     * override ueventd.rc
164     */
165    list_for_each_reverse(node, &dev_perms) {
166        perm_node = node_to_item(node, struct perm_node, plist);
167        dp = &perm_node->dp;
168
169        if (dp->prefix) {
170            if (strncmp(path, dp->name, strlen(dp->name)))
171                continue;
172        } else {
173            if (strcmp(path, dp->name))
174                continue;
175        }
176        *uid = dp->uid;
177        *gid = dp->gid;
178        return dp->perm;
179    }
180    /* Default if nothing found. */
181    *uid = 0;
182    *gid = 0;
183    return 0600;
184}
185
186static void make_device(const char *path,
187                        const char *upath,
188                        int block, int major, int minor)
189{
190    unsigned uid;
191    unsigned gid;
192    mode_t mode;
193    dev_t dev;
194#ifdef HAVE_SELINUX
195    char *secontext = NULL;
196#endif
197
198    mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR);
199#ifdef HAVE_SELINUX
200    if (sehandle) {
201        selabel_lookup(sehandle, &secontext, path, mode);
202        setfscreatecon(secontext);
203    }
204#endif
205    dev = makedev(major, minor);
206    /* Temporarily change egid to avoid race condition setting the gid of the
207     * device node. Unforunately changing the euid would prevent creation of
208     * some device nodes, so the uid has to be set with chown() and is still
209     * racy. Fixing the gid race at least fixed the issue with system_server
210     * opening dynamic input devices under the AID_INPUT gid. */
211    setegid(gid);
212    mknod(path, mode, dev);
213    chown(path, uid, -1);
214    setegid(AID_ROOT);
215#ifdef HAVE_SELINUX
216    if (secontext) {
217        freecon(secontext);
218        setfscreatecon(NULL);
219    }
220#endif
221}
222
223
224static int make_dir(const char *path, mode_t mode)
225{
226    int rc;
227
228#ifdef HAVE_SELINUX
229    char *secontext = NULL;
230
231    if (sehandle) {
232        selabel_lookup(sehandle, &secontext, path, mode);
233        setfscreatecon(secontext);
234    }
235#endif
236
237    rc = mkdir(path, mode);
238
239#ifdef HAVE_SELINUX
240    if (secontext) {
241        freecon(secontext);
242        setfscreatecon(NULL);
243    }
244#endif
245    return rc;
246}
247
248
249static void add_platform_device(const char *name)
250{
251    int name_len = strlen(name);
252    struct listnode *node;
253    struct platform_node *bus;
254
255    list_for_each_reverse(node, &platform_names) {
256        bus = node_to_item(node, struct platform_node, list);
257        if ((bus->name_len < name_len) &&
258                (name[bus->name_len] == '/') &&
259                !strncmp(name, bus->name, bus->name_len))
260            /* subdevice of an existing platform, ignore it */
261            return;
262    }
263
264    INFO("adding platform device %s\n", name);
265
266    bus = calloc(1, sizeof(struct platform_node));
267    bus->name = strdup(name);
268    bus->name_len = name_len;
269    list_add_tail(&platform_names, &bus->list);
270}
271
272/*
273 * given a name that may start with a platform device, find the length of the
274 * platform device prefix.  If it doesn't start with a platform device, return
275 * 0.
276 */
277static const char *find_platform_device(const char *name)
278{
279    int name_len = strlen(name);
280    struct listnode *node;
281    struct platform_node *bus;
282
283    list_for_each_reverse(node, &platform_names) {
284        bus = node_to_item(node, struct platform_node, list);
285        if ((bus->name_len < name_len) &&
286                (name[bus->name_len] == '/') &&
287                !strncmp(name, bus->name, bus->name_len))
288            return bus->name;
289    }
290
291    return NULL;
292}
293
294static void remove_platform_device(const char *name)
295{
296    struct listnode *node;
297    struct platform_node *bus;
298
299    list_for_each_reverse(node, &platform_names) {
300        bus = node_to_item(node, struct platform_node, list);
301        if (!strcmp(name, bus->name)) {
302            INFO("removing platform device %s\n", name);
303            free(bus->name);
304            list_remove(node);
305            free(bus);
306            return;
307        }
308    }
309}
310
311#if LOG_UEVENTS
312
313static inline suseconds_t get_usecs(void)
314{
315    struct timeval tv;
316    gettimeofday(&tv, 0);
317    return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec;
318}
319
320#define log_event_print(x...) INFO(x)
321
322#else
323
324#define log_event_print(fmt, args...)   do { } while (0)
325#define get_usecs()                     0
326
327#endif
328
329static void parse_event(const char *msg, struct uevent *uevent)
330{
331    uevent->action = "";
332    uevent->path = "";
333    uevent->subsystem = "";
334    uevent->firmware = "";
335    uevent->major = -1;
336    uevent->minor = -1;
337    uevent->partition_name = NULL;
338    uevent->partition_num = -1;
339    uevent->device_name = NULL;
340
341        /* currently ignoring SEQNUM */
342    while(*msg) {
343        if(!strncmp(msg, "ACTION=", 7)) {
344            msg += 7;
345            uevent->action = msg;
346        } else if(!strncmp(msg, "DEVPATH=", 8)) {
347            msg += 8;
348            uevent->path = msg;
349        } else if(!strncmp(msg, "SUBSYSTEM=", 10)) {
350            msg += 10;
351            uevent->subsystem = msg;
352        } else if(!strncmp(msg, "FIRMWARE=", 9)) {
353            msg += 9;
354            uevent->firmware = msg;
355        } else if(!strncmp(msg, "MAJOR=", 6)) {
356            msg += 6;
357            uevent->major = atoi(msg);
358        } else if(!strncmp(msg, "MINOR=", 6)) {
359            msg += 6;
360            uevent->minor = atoi(msg);
361        } else if(!strncmp(msg, "PARTN=", 6)) {
362            msg += 6;
363            uevent->partition_num = atoi(msg);
364        } else if(!strncmp(msg, "PARTNAME=", 9)) {
365            msg += 9;
366            uevent->partition_name = msg;
367        } else if(!strncmp(msg, "DEVNAME=", 8)) {
368            msg += 8;
369            uevent->device_name = msg;
370        }
371
372        /* advance to after the next \0 */
373        while(*msg++)
374            ;
375    }
376
377    log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n",
378                    uevent->action, uevent->path, uevent->subsystem,
379                    uevent->firmware, uevent->major, uevent->minor);
380}
381
382static char **get_character_device_symlinks(struct uevent *uevent)
383{
384    const char *parent;
385    char *slash;
386    char **links;
387    int link_num = 0;
388    int width;
389
390    if (strncmp(uevent->path, "/devices/platform/", 18))
391        return NULL;
392
393    links = malloc(sizeof(char *) * 2);
394    if (!links)
395        return NULL;
396    memset(links, 0, sizeof(char *) * 2);
397
398    /* skip "/devices/platform/<driver>" */
399    parent = strchr(uevent->path + 18, '/');
400    if (!*parent)
401        goto err;
402
403    if (!strncmp(parent, "/usb", 4)) {
404        /* skip root hub name and device. use device interface */
405        while (*++parent && *parent != '/');
406        if (*parent)
407            while (*++parent && *parent != '/');
408        if (!*parent)
409            goto err;
410        slash = strchr(++parent, '/');
411        if (!slash)
412            goto err;
413        width = slash - parent;
414        if (width <= 0)
415            goto err;
416
417        if (asprintf(&links[link_num], "/dev/usb/%s%.*s", uevent->subsystem, width, parent) > 0)
418            link_num++;
419        else
420            links[link_num] = NULL;
421        mkdir("/dev/usb", 0755);
422    }
423    else {
424        goto err;
425    }
426
427    return links;
428err:
429    free(links);
430    return NULL;
431}
432
433static char **parse_platform_block_device(struct uevent *uevent)
434{
435    const char *device;
436    const char *path;
437    char *slash;
438    int width;
439    char buf[256];
440    char link_path[256];
441    int fd;
442    int link_num = 0;
443    int ret;
444    char *p;
445    unsigned int size;
446    struct stat info;
447
448    char **links = malloc(sizeof(char *) * 4);
449    if (!links)
450        return NULL;
451    memset(links, 0, sizeof(char *) * 4);
452
453    /* Drop "/devices/platform/" */
454    path = uevent->path;
455    device = path + 18;
456    device = find_platform_device(device);
457    if (!device)
458        goto err;
459
460    INFO("found platform device %s\n", device);
461
462    snprintf(link_path, sizeof(link_path), "/dev/block/platform/%s", device);
463
464    if (uevent->partition_name) {
465        p = strdup(uevent->partition_name);
466        sanitize(p);
467        if (asprintf(&links[link_num], "%s/by-name/%s", link_path, p) > 0)
468            link_num++;
469        else
470            links[link_num] = NULL;
471        free(p);
472    }
473
474    if (uevent->partition_num >= 0) {
475        if (asprintf(&links[link_num], "%s/by-num/p%d", link_path, uevent->partition_num) > 0)
476            link_num++;
477        else
478            links[link_num] = NULL;
479    }
480
481    slash = strrchr(path, '/');
482    if (asprintf(&links[link_num], "%s/%s", link_path, slash + 1) > 0)
483        link_num++;
484    else
485        links[link_num] = NULL;
486
487    return links;
488
489err:
490    free(links);
491    return NULL;
492}
493
494static void handle_device(const char *action, const char *devpath,
495        const char *path, int block, int major, int minor, char **links)
496{
497    int i;
498
499    if(!strcmp(action, "add")) {
500        make_device(devpath, path, block, major, minor);
501        if (links) {
502            for (i = 0; links[i]; i++)
503                make_link(devpath, links[i]);
504        }
505    }
506
507    if(!strcmp(action, "remove")) {
508        if (links) {
509            for (i = 0; links[i]; i++)
510                remove_link(devpath, links[i]);
511        }
512        unlink(devpath);
513    }
514
515    if (links) {
516        for (i = 0; links[i]; i++)
517            free(links[i]);
518        free(links);
519    }
520}
521
522static void handle_platform_device_event(struct uevent *uevent)
523{
524    const char *name = uevent->path + 18; /* length of /devices/platform/ */
525
526    if (!strcmp(uevent->action, "add"))
527        add_platform_device(name);
528    else if (!strcmp(uevent->action, "remove"))
529        remove_platform_device(name);
530}
531
532static const char *parse_device_name(struct uevent *uevent, unsigned int len)
533{
534    const char *name;
535
536    /* if it's not a /dev device, nothing else to do */
537    if((uevent->major < 0) || (uevent->minor < 0))
538        return NULL;
539
540    /* do we have a name? */
541    name = strrchr(uevent->path, '/');
542    if(!name)
543        return NULL;
544    name++;
545
546    /* too-long names would overrun our buffer */
547    if(strlen(name) > len)
548        return NULL;
549
550    return name;
551}
552
553static void handle_block_device_event(struct uevent *uevent)
554{
555    const char *base = "/dev/block/";
556    const char *name;
557    char devpath[96];
558    char **links = NULL;
559
560    name = parse_device_name(uevent, 64);
561    if (!name)
562        return;
563
564    snprintf(devpath, sizeof(devpath), "%s%s", base, name);
565    make_dir(base, 0755);
566
567    if (!strncmp(uevent->path, "/devices/platform/", 18))
568        links = parse_platform_block_device(uevent);
569
570    handle_device(uevent->action, devpath, uevent->path, 1,
571            uevent->major, uevent->minor, links);
572}
573
574static void handle_generic_device_event(struct uevent *uevent)
575{
576    char *base;
577    const char *name;
578    char devpath[96] = {0};
579    char **links = NULL;
580
581    name = parse_device_name(uevent, 64);
582    if (!name)
583        return;
584
585    if (!strncmp(uevent->subsystem, "usb", 3)) {
586         if (!strcmp(uevent->subsystem, "usb")) {
587            if (uevent->device_name) {
588                /*
589                 * create device node provided by kernel if present
590                 * see drivers/base/core.c
591                 */
592                char *p = devpath;
593                snprintf(devpath, sizeof(devpath), "/dev/%s", uevent->device_name);
594                /* skip leading /dev/ */
595                p += 5;
596                /* build directories */
597                while (*p) {
598                    if (*p == '/') {
599                        *p = 0;
600                        make_dir(devpath, 0755);
601                        *p = '/';
602                    }
603                    p++;
604                }
605             }
606             else {
607                 /* This imitates the file system that would be created
608                  * if we were using devfs instead.
609                  * Minors are broken up into groups of 128, starting at "001"
610                  */
611                 int bus_id = uevent->minor / 128 + 1;
612                 int device_id = uevent->minor % 128 + 1;
613                 /* build directories */
614                 make_dir("/dev/bus", 0755);
615                 make_dir("/dev/bus/usb", 0755);
616                 snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d", bus_id);
617                 make_dir(devpath, 0755);
618                 snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d/%03d", bus_id, device_id);
619             }
620         } else {
621             /* ignore other USB events */
622             return;
623         }
624     } else if (!strncmp(uevent->subsystem, "graphics", 8)) {
625         base = "/dev/graphics/";
626         make_dir(base, 0755);
627     } else if (!strncmp(uevent->subsystem, "drm", 3)) {
628         base = "/dev/dri/";
629         make_dir(base, 0755);
630     } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) {
631         base = "/dev/oncrpc/";
632         make_dir(base, 0755);
633     } else if (!strncmp(uevent->subsystem, "adsp", 4)) {
634         base = "/dev/adsp/";
635         make_dir(base, 0755);
636     } else if (!strncmp(uevent->subsystem, "msm_camera", 10)) {
637         base = "/dev/msm_camera/";
638         make_dir(base, 0755);
639     } else if(!strncmp(uevent->subsystem, "input", 5)) {
640         base = "/dev/input/";
641         make_dir(base, 0755);
642     } else if(!strncmp(uevent->subsystem, "mtd", 3)) {
643         base = "/dev/mtd/";
644         make_dir(base, 0755);
645     } else if(!strncmp(uevent->subsystem, "sound", 5)) {
646         base = "/dev/snd/";
647         make_dir(base, 0755);
648     } else if(!strncmp(uevent->subsystem, "misc", 4) &&
649                 !strncmp(name, "log_", 4)) {
650         base = "/dev/log/";
651         make_dir(base, 0755);
652         name += 4;
653     } else
654         base = "/dev/";
655     links = get_character_device_symlinks(uevent);
656
657     if (!devpath[0])
658         snprintf(devpath, sizeof(devpath), "%s%s", base, name);
659
660     handle_device(uevent->action, devpath, uevent->path, 0,
661             uevent->major, uevent->minor, links);
662}
663
664static void handle_device_event(struct uevent *uevent)
665{
666    if (!strcmp(uevent->action,"add"))
667        fixup_sys_perms(uevent->path);
668
669    if (!strncmp(uevent->subsystem, "block", 5)) {
670        handle_block_device_event(uevent);
671    } else if (!strncmp(uevent->subsystem, "platform", 8)) {
672        handle_platform_device_event(uevent);
673    } else {
674        handle_generic_device_event(uevent);
675    }
676}
677
678static int load_firmware(int fw_fd, int loading_fd, int data_fd)
679{
680    struct stat st;
681    long len_to_copy;
682    int ret = 0;
683
684    if(fstat(fw_fd, &st) < 0)
685        return -1;
686    len_to_copy = st.st_size;
687
688    write(loading_fd, "1", 1);  /* start transfer */
689
690    while (len_to_copy > 0) {
691        char buf[PAGE_SIZE];
692        ssize_t nr;
693
694        nr = read(fw_fd, buf, sizeof(buf));
695        if(!nr)
696            break;
697        if(nr < 0) {
698            ret = -1;
699            break;
700        }
701
702        len_to_copy -= nr;
703        while (nr > 0) {
704            ssize_t nw = 0;
705
706            nw = write(data_fd, buf + nw, nr);
707            if(nw <= 0) {
708                ret = -1;
709                goto out;
710            }
711            nr -= nw;
712        }
713    }
714
715out:
716    if(!ret)
717        write(loading_fd, "0", 1);  /* successful end of transfer */
718    else
719        write(loading_fd, "-1", 2); /* abort transfer */
720
721    return ret;
722}
723
724static int is_booting(void)
725{
726    return access("/dev/.booting", F_OK) == 0;
727}
728
729static void process_firmware_event(struct uevent *uevent)
730{
731    char *root, *loading, *data, *file1 = NULL, *file2 = NULL;
732    int l, loading_fd, data_fd, fw_fd;
733    int booting = is_booting();
734
735    INFO("firmware: loading '%s' for '%s'\n",
736         uevent->firmware, uevent->path);
737
738    l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path);
739    if (l == -1)
740        return;
741
742    l = asprintf(&loading, "%sloading", root);
743    if (l == -1)
744        goto root_free_out;
745
746    l = asprintf(&data, "%sdata", root);
747    if (l == -1)
748        goto loading_free_out;
749
750    l = asprintf(&file1, FIRMWARE_DIR1"/%s", uevent->firmware);
751    if (l == -1)
752        goto data_free_out;
753
754    l = asprintf(&file2, FIRMWARE_DIR2"/%s", uevent->firmware);
755    if (l == -1)
756        goto data_free_out;
757
758    loading_fd = open(loading, O_WRONLY);
759    if(loading_fd < 0)
760        goto file_free_out;
761
762    data_fd = open(data, O_WRONLY);
763    if(data_fd < 0)
764        goto loading_close_out;
765
766try_loading_again:
767    fw_fd = open(file1, O_RDONLY);
768    if(fw_fd < 0) {
769        fw_fd = open(file2, O_RDONLY);
770        if (fw_fd < 0) {
771            if (booting) {
772                    /* If we're not fully booted, we may be missing
773                     * filesystems needed for firmware, wait and retry.
774                     */
775                usleep(100000);
776                booting = is_booting();
777                goto try_loading_again;
778            }
779            INFO("firmware: could not open '%s' %d\n", uevent->firmware, errno);
780            write(loading_fd, "-1", 2);
781            goto data_close_out;
782        }
783    }
784
785    if(!load_firmware(fw_fd, loading_fd, data_fd))
786        INFO("firmware: copy success { '%s', '%s' }\n", root, uevent->firmware);
787    else
788        INFO("firmware: copy failure { '%s', '%s' }\n", root, uevent->firmware);
789
790    close(fw_fd);
791data_close_out:
792    close(data_fd);
793loading_close_out:
794    close(loading_fd);
795file_free_out:
796    free(file1);
797    free(file2);
798data_free_out:
799    free(data);
800loading_free_out:
801    free(loading);
802root_free_out:
803    free(root);
804}
805
806static void handle_firmware_event(struct uevent *uevent)
807{
808    pid_t pid;
809    int ret;
810
811    if(strcmp(uevent->subsystem, "firmware"))
812        return;
813
814    if(strcmp(uevent->action, "add"))
815        return;
816
817    /* we fork, to avoid making large memory allocations in init proper */
818    pid = fork();
819    if (!pid) {
820        process_firmware_event(uevent);
821        exit(EXIT_SUCCESS);
822    }
823}
824
825#define UEVENT_MSG_LEN  1024
826void handle_device_fd()
827{
828    char msg[UEVENT_MSG_LEN+2];
829    int n;
830    while ((n = uevent_kernel_multicast_recv(device_fd, msg, UEVENT_MSG_LEN)) > 0) {
831        if(n >= UEVENT_MSG_LEN)   /* overflow -- discard */
832            continue;
833
834        msg[n] = '\0';
835        msg[n+1] = '\0';
836
837        struct uevent uevent;
838        parse_event(msg, &uevent);
839
840        handle_device_event(&uevent);
841        handle_firmware_event(&uevent);
842    }
843}
844
845/* Coldboot walks parts of the /sys tree and pokes the uevent files
846** to cause the kernel to regenerate device add events that happened
847** before init's device manager was started
848**
849** We drain any pending events from the netlink socket every time
850** we poke another uevent file to make sure we don't overrun the
851** socket's buffer.
852*/
853
854static void do_coldboot(DIR *d)
855{
856    struct dirent *de;
857    int dfd, fd;
858
859    dfd = dirfd(d);
860
861    fd = openat(dfd, "uevent", O_WRONLY);
862    if(fd >= 0) {
863        write(fd, "add\n", 4);
864        close(fd);
865        handle_device_fd();
866    }
867
868    while((de = readdir(d))) {
869        DIR *d2;
870
871        if(de->d_type != DT_DIR || de->d_name[0] == '.')
872            continue;
873
874        fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY);
875        if(fd < 0)
876            continue;
877
878        d2 = fdopendir(fd);
879        if(d2 == 0)
880            close(fd);
881        else {
882            do_coldboot(d2);
883            closedir(d2);
884        }
885    }
886}
887
888static void coldboot(const char *path)
889{
890    DIR *d = opendir(path);
891    if(d) {
892        do_coldboot(d);
893        closedir(d);
894    }
895}
896
897void device_init(void)
898{
899    suseconds_t t0, t1;
900    struct stat info;
901    int fd;
902#ifdef HAVE_SELINUX
903    struct selinux_opt seopts[] = {
904        { SELABEL_OPT_PATH, "/file_contexts" }
905    };
906
907    if (is_selinux_enabled() > 0)
908        sehandle = selabel_open(SELABEL_CTX_FILE, seopts, 1);
909#endif
910    /* is 64K enough? udev uses 16MB! */
911    device_fd = uevent_open_socket(64*1024, true);
912    if(device_fd < 0)
913        return;
914
915    fcntl(device_fd, F_SETFD, FD_CLOEXEC);
916    fcntl(device_fd, F_SETFL, O_NONBLOCK);
917
918    if (stat(coldboot_done, &info) < 0) {
919        t0 = get_usecs();
920        coldboot("/sys/class");
921        coldboot("/sys/block");
922        coldboot("/sys/devices");
923        t1 = get_usecs();
924        fd = open(coldboot_done, O_WRONLY|O_CREAT, 0000);
925        close(fd);
926        log_event_print("coldboot %ld uS\n", ((long) (t1 - t0)));
927    } else {
928        log_event_print("skipping coldboot, already done\n");
929    }
930}
931
932int get_device_fd()
933{
934    return device_fd;
935}
936