devices.c revision 43d537e0deeb4ba20e13db22e4fc28b87a4621c7 
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 bool perm_path_matches(const char *path, struct perms_ *dp)
174{
175    if (dp->prefix) {
176        if (strncmp(path, dp->name, strlen(dp->name)) == 0)
177            return true;
178    } else if (dp->wildcard) {
179        if (fnmatch(dp->name, path, FNM_PATHNAME) == 0)
180            return true;
181    } else {
182        if (strcmp(path, dp->name) == 0)
183            return true;
184    }
185
186    return false;
187}
188
189static mode_t get_device_perm(const char *path, const char **links,
190                unsigned *uid, unsigned *gid)
191{
192    mode_t perm;
193    struct listnode *node;
194    struct perm_node *perm_node;
195    struct perms_ *dp;
196
197    /* search the perms list in reverse so that ueventd.$hardware can
198     * override ueventd.rc
199     */
200    list_for_each_reverse(node, &dev_perms) {
201        bool match = false;
202
203        perm_node = node_to_item(node, struct perm_node, plist);
204        dp = &perm_node->dp;
205
206        if (perm_path_matches(path, dp)) {
207            match = true;
208        } else {
209            if (links) {
210                int i;
211                for (i = 0; links[i]; i++) {
212                    if (perm_path_matches(links[i], dp)) {
213                        match = true;
214                        break;
215                    }
216                }
217            }
218        }
219
220        if (match) {
221            *uid = dp->uid;
222            *gid = dp->gid;
223            return dp->perm;
224        }
225    }
226    /* Default if nothing found. */
227    *uid = 0;
228    *gid = 0;
229    return 0600;
230}
231
232static void make_device(const char *path,
233                        const char *upath UNUSED,
234                        int block, int major, int minor,
235                        const char **links)
236{
237    unsigned uid;
238    unsigned gid;
239    mode_t mode;
240    dev_t dev;
241    char *secontext = NULL;
242
243    mode = get_device_perm(path, links, &uid, &gid) | (block ? S_IFBLK : S_IFCHR);
244
245    if (sehandle) {
246        selabel_lookup_best_match(sehandle, &secontext, path, links, mode);
247        setfscreatecon(secontext);
248    }
249
250    dev = makedev(major, minor);
251    /* Temporarily change egid to avoid race condition setting the gid of the
252     * device node. Unforunately changing the euid would prevent creation of
253     * some device nodes, so the uid has to be set with chown() and is still
254     * racy. Fixing the gid race at least fixed the issue with system_server
255     * opening dynamic input devices under the AID_INPUT gid. */
256    setegid(gid);
257    mknod(path, mode, dev);
258    chown(path, uid, -1);
259    setegid(AID_ROOT);
260
261    if (secontext) {
262        freecon(secontext);
263        setfscreatecon(NULL);
264    }
265}
266
267static void add_platform_device(const char *path)
268{
269    int path_len = strlen(path);
270    struct listnode *node;
271    struct platform_node *bus;
272    const char *name = path;
273
274    if (!strncmp(path, "/devices/", 9)) {
275        name += 9;
276        if (!strncmp(name, "platform/", 9))
277            name += 9;
278    }
279
280    list_for_each_reverse(node, &platform_names) {
281        bus = node_to_item(node, struct platform_node, list);
282        if ((bus->path_len < path_len) &&
283                (path[bus->path_len] == '/') &&
284                !strncmp(path, bus->path, bus->path_len))
285            /* subdevice of an existing platform, ignore it */
286            return;
287    }
288
289    INFO("adding platform device %s (%s)\n", name, path);
290
291    bus = calloc(1, sizeof(struct platform_node));
292    bus->path = strdup(path);
293    bus->path_len = path_len;
294    bus->name = bus->path + (name - path);
295    list_add_tail(&platform_names, &bus->list);
296}
297
298/*
299 * given a path that may start with a platform device, find the length of the
300 * platform device prefix.  If it doesn't start with a platform device, return
301 * 0.
302 */
303static struct platform_node *find_platform_device(const char *path)
304{
305    int path_len = strlen(path);
306    struct listnode *node;
307    struct platform_node *bus;
308
309    list_for_each_reverse(node, &platform_names) {
310        bus = node_to_item(node, struct platform_node, list);
311        if ((bus->path_len < path_len) &&
312                (path[bus->path_len] == '/') &&
313                !strncmp(path, bus->path, bus->path_len))
314            return bus;
315    }
316
317    return NULL;
318}
319
320static void remove_platform_device(const char *path)
321{
322    struct listnode *node;
323    struct platform_node *bus;
324
325    list_for_each_reverse(node, &platform_names) {
326        bus = node_to_item(node, struct platform_node, list);
327        if (!strcmp(path, bus->path)) {
328            INFO("removing platform device %s\n", bus->name);
329            free(bus->path);
330            list_remove(node);
331            free(bus);
332            return;
333        }
334    }
335}
336
337/* Given a path that may start with a PCI device, populate the supplied buffer
338 * with the PCI domain/bus number and the peripheral ID and return 0.
339 * If it doesn't start with a PCI device, or there is some error, return -1 */
340static int find_pci_device_prefix(const char *path, char *buf, ssize_t buf_sz)
341{
342    const char *start, *end;
343
344    if (strncmp(path, "/devices/pci", 12))
345        return -1;
346
347    /* Beginning of the prefix is the initial "pci" after "/devices/" */
348    start = path + 9;
349
350    /* End of the prefix is two path '/' later, capturing the domain/bus number
351     * and the peripheral ID. Example: pci0000:00/0000:00:1f.2 */
352    end = strchr(start, '/');
353    if (!end)
354        return -1;
355    end = strchr(end + 1, '/');
356    if (!end)
357        return -1;
358
359    /* Make sure we have enough room for the string plus null terminator */
360    if (end - start + 1 > buf_sz)
361        return -1;
362
363    strncpy(buf, start, end - start);
364    buf[end - start] = '\0';
365    return 0;
366}
367
368#if LOG_UEVENTS
369
370static inline suseconds_t get_usecs(void)
371{
372    struct timeval tv;
373    gettimeofday(&tv, 0);
374    return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec;
375}
376
377#define log_event_print(x...) INFO(x)
378
379#else
380
381#define log_event_print(fmt, args...)   do { } while (0)
382#define get_usecs()                     0
383
384#endif
385
386static void parse_event(const char *msg, struct uevent *uevent)
387{
388    uevent->action = "";
389    uevent->path = "";
390    uevent->subsystem = "";
391    uevent->firmware = "";
392    uevent->major = -1;
393    uevent->minor = -1;
394    uevent->partition_name = NULL;
395    uevent->partition_num = -1;
396    uevent->device_name = NULL;
397
398        /* currently ignoring SEQNUM */
399    while(*msg) {
400        if(!strncmp(msg, "ACTION=", 7)) {
401            msg += 7;
402            uevent->action = msg;
403        } else if(!strncmp(msg, "DEVPATH=", 8)) {
404            msg += 8;
405            uevent->path = msg;
406        } else if(!strncmp(msg, "SUBSYSTEM=", 10)) {
407            msg += 10;
408            uevent->subsystem = msg;
409        } else if(!strncmp(msg, "FIRMWARE=", 9)) {
410            msg += 9;
411            uevent->firmware = msg;
412        } else if(!strncmp(msg, "MAJOR=", 6)) {
413            msg += 6;
414            uevent->major = atoi(msg);
415        } else if(!strncmp(msg, "MINOR=", 6)) {
416            msg += 6;
417            uevent->minor = atoi(msg);
418        } else if(!strncmp(msg, "PARTN=", 6)) {
419            msg += 6;
420            uevent->partition_num = atoi(msg);
421        } else if(!strncmp(msg, "PARTNAME=", 9)) {
422            msg += 9;
423            uevent->partition_name = msg;
424        } else if(!strncmp(msg, "DEVNAME=", 8)) {
425            msg += 8;
426            uevent->device_name = msg;
427        }
428
429        /* advance to after the next \0 */
430        while(*msg++)
431            ;
432    }
433
434    log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n",
435                    uevent->action, uevent->path, uevent->subsystem,
436                    uevent->firmware, uevent->major, uevent->minor);
437}
438
439static char **get_character_device_symlinks(struct uevent *uevent)
440{
441    const char *parent;
442    char *slash;
443    char **links;
444    int link_num = 0;
445    int width;
446    struct platform_node *pdev;
447
448    pdev = find_platform_device(uevent->path);
449    if (!pdev)
450        return NULL;
451
452    links = malloc(sizeof(char *) * 2);
453    if (!links)
454        return NULL;
455    memset(links, 0, sizeof(char *) * 2);
456
457    /* skip "/devices/platform/<driver>" */
458    parent = strchr(uevent->path + pdev->path_len, '/');
459    if (!*parent)
460        goto err;
461
462    if (!strncmp(parent, "/usb", 4)) {
463        /* skip root hub name and device. use device interface */
464        while (*++parent && *parent != '/');
465        if (*parent)
466            while (*++parent && *parent != '/');
467        if (!*parent)
468            goto err;
469        slash = strchr(++parent, '/');
470        if (!slash)
471            goto err;
472        width = slash - parent;
473        if (width <= 0)
474            goto err;
475
476        if (asprintf(&links[link_num], "/dev/usb/%s%.*s", uevent->subsystem, width, parent) > 0)
477            link_num++;
478        else
479            links[link_num] = NULL;
480        mkdir("/dev/usb", 0755);
481    }
482    else {
483        goto err;
484    }
485
486    return links;
487err:
488    free(links);
489    return NULL;
490}
491
492static char **get_block_device_symlinks(struct uevent *uevent)
493{
494    const char *device;
495    struct platform_node *pdev;
496    char *slash;
497    const char *type;
498    int width;
499    char buf[256];
500    char link_path[256];
501    int fd;
502    int link_num = 0;
503    int ret;
504    char *p;
505    unsigned int size;
506    struct stat info;
507
508    pdev = find_platform_device(uevent->path);
509    if (pdev) {
510        device = pdev->name;
511        type = "platform";
512    } else if (!find_pci_device_prefix(uevent->path, buf, sizeof(buf))) {
513        device = buf;
514        type = "pci";
515    } else {
516        return NULL;
517    }
518
519    char **links = malloc(sizeof(char *) * 4);
520    if (!links)
521        return NULL;
522    memset(links, 0, sizeof(char *) * 4);
523
524    INFO("found %s device %s\n", type, device);
525
526    snprintf(link_path, sizeof(link_path), "/dev/block/%s/%s", type, device);
527
528    if (uevent->partition_name) {
529        p = strdup(uevent->partition_name);
530        sanitize(p);
531        if (strcmp(uevent->partition_name, p))
532            NOTICE("Linking partition '%s' as '%s'\n", uevent->partition_name, p);
533        if (asprintf(&links[link_num], "%s/by-name/%s", link_path, p) > 0)
534            link_num++;
535        else
536            links[link_num] = NULL;
537        free(p);
538    }
539
540    if (uevent->partition_num >= 0) {
541        if (asprintf(&links[link_num], "%s/by-num/p%d", link_path, uevent->partition_num) > 0)
542            link_num++;
543        else
544            links[link_num] = NULL;
545    }
546
547    slash = strrchr(uevent->path, '/');
548    if (asprintf(&links[link_num], "%s/%s", link_path, slash + 1) > 0)
549        link_num++;
550    else
551        links[link_num] = NULL;
552
553    return links;
554}
555
556static void handle_device(const char *action, const char *devpath,
557        const char *path, int block, int major, int minor, char **links)
558{
559    int i;
560
561    if(!strcmp(action, "add")) {
562        make_device(devpath, path, block, major, minor, (const char **)links);
563        if (links) {
564            for (i = 0; links[i]; i++)
565                make_link(devpath, links[i]);
566        }
567    }
568
569    if(!strcmp(action, "remove")) {
570        if (links) {
571            for (i = 0; links[i]; i++)
572                remove_link(devpath, links[i]);
573        }
574        unlink(devpath);
575    }
576
577    if (links) {
578        for (i = 0; links[i]; i++)
579            free(links[i]);
580        free(links);
581    }
582}
583
584static void handle_platform_device_event(struct uevent *uevent)
585{
586    const char *path = uevent->path;
587
588    if (!strcmp(uevent->action, "add"))
589        add_platform_device(path);
590    else if (!strcmp(uevent->action, "remove"))
591        remove_platform_device(path);
592}
593
594static const char *parse_device_name(struct uevent *uevent, unsigned int len)
595{
596    const char *name;
597
598    /* if it's not a /dev device, nothing else to do */
599    if((uevent->major < 0) || (uevent->minor < 0))
600        return NULL;
601
602    /* do we have a name? */
603    name = strrchr(uevent->path, '/');
604    if(!name)
605        return NULL;
606    name++;
607
608    /* too-long names would overrun our buffer */
609    if(strlen(name) > len) {
610        ERROR("DEVPATH=%s exceeds %u-character limit on filename; ignoring event\n",
611                name, len);
612        return NULL;
613    }
614
615    return name;
616}
617
618static void handle_block_device_event(struct uevent *uevent)
619{
620    const char *base = "/dev/block/";
621    const char *name;
622    char devpath[96];
623    char **links = NULL;
624
625    name = parse_device_name(uevent, 64);
626    if (!name)
627        return;
628
629    snprintf(devpath, sizeof(devpath), "%s%s", base, name);
630    make_dir(base, 0755);
631
632    if (!strncmp(uevent->path, "/devices/", 9))
633        links = get_block_device_symlinks(uevent);
634
635    handle_device(uevent->action, devpath, uevent->path, 1,
636            uevent->major, uevent->minor, links);
637}
638
639#define DEVPATH_LEN 96
640
641static bool assemble_devpath(char *devpath, const char *dirname,
642        const char *devname)
643{
644    int s = snprintf(devpath, DEVPATH_LEN, "%s/%s", dirname, devname);
645    if (s < 0) {
646        ERROR("failed to assemble device path (%s); ignoring event\n",
647                strerror(errno));
648        return false;
649    } else if (s >= DEVPATH_LEN) {
650        ERROR("%s/%s exceeds %u-character limit on path; ignoring event\n",
651                dirname, devname, DEVPATH_LEN);
652        return false;
653    }
654    return true;
655}
656
657static void mkdir_recursive_for_devpath(const char *devpath)
658{
659    char dir[DEVPATH_LEN];
660    char *slash;
661
662    strcpy(dir, devpath);
663    slash = strrchr(dir, '/');
664    *slash = '\0';
665    mkdir_recursive(dir, 0755);
666}
667
668static inline void __attribute__((__deprecated__)) kernel_logger()
669{
670    INFO("kernel logger is deprecated\n");
671}
672
673static void handle_generic_device_event(struct uevent *uevent)
674{
675    char *base;
676    const char *name;
677    char devpath[DEVPATH_LEN] = {0};
678    char **links = NULL;
679
680    name = parse_device_name(uevent, 64);
681    if (!name)
682        return;
683
684    struct ueventd_subsystem *subsystem =
685            ueventd_subsystem_find_by_name(uevent->subsystem);
686
687    if (subsystem) {
688        const char *devname;
689
690        switch (subsystem->devname_src) {
691        case DEVNAME_UEVENT_DEVNAME:
692            devname = uevent->device_name;
693            break;
694
695        case DEVNAME_UEVENT_DEVPATH:
696            devname = name;
697            break;
698
699        default:
700            ERROR("%s subsystem's devpath option is not set; ignoring event\n",
701                    uevent->subsystem);
702            return;
703        }
704
705        if (!assemble_devpath(devpath, subsystem->dirname, devname))
706            return;
707        mkdir_recursive_for_devpath(devpath);
708    } else if (!strncmp(uevent->subsystem, "usb", 3)) {
709         if (!strcmp(uevent->subsystem, "usb")) {
710            if (uevent->device_name) {
711                if (!assemble_devpath(devpath, "/dev", uevent->device_name))
712                    return;
713                mkdir_recursive_for_devpath(devpath);
714             }
715             else {
716                 /* This imitates the file system that would be created
717                  * if we were using devfs instead.
718                  * Minors are broken up into groups of 128, starting at "001"
719                  */
720                 int bus_id = uevent->minor / 128 + 1;
721                 int device_id = uevent->minor % 128 + 1;
722                 /* build directories */
723                 make_dir("/dev/bus", 0755);
724                 make_dir("/dev/bus/usb", 0755);
725                 snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d", bus_id);
726                 make_dir(devpath, 0755);
727                 snprintf(devpath, sizeof(devpath), "/dev/bus/usb/%03d/%03d", bus_id, device_id);
728             }
729         } else {
730             /* ignore other USB events */
731             return;
732         }
733     } else if (!strncmp(uevent->subsystem, "graphics", 8)) {
734         base = "/dev/graphics/";
735         make_dir(base, 0755);
736     } else if (!strncmp(uevent->subsystem, "drm", 3)) {
737         base = "/dev/dri/";
738         make_dir(base, 0755);
739     } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) {
740         base = "/dev/oncrpc/";
741         make_dir(base, 0755);
742     } else if (!strncmp(uevent->subsystem, "adsp", 4)) {
743         base = "/dev/adsp/";
744         make_dir(base, 0755);
745     } else if (!strncmp(uevent->subsystem, "msm_camera", 10)) {
746         base = "/dev/msm_camera/";
747         make_dir(base, 0755);
748     } else if(!strncmp(uevent->subsystem, "input", 5)) {
749         base = "/dev/input/";
750         make_dir(base, 0755);
751     } else if(!strncmp(uevent->subsystem, "mtd", 3)) {
752         base = "/dev/mtd/";
753         make_dir(base, 0755);
754     } else if(!strncmp(uevent->subsystem, "sound", 5)) {
755         base = "/dev/snd/";
756         make_dir(base, 0755);
757     } else if(!strncmp(uevent->subsystem, "misc", 4) &&
758                 !strncmp(name, "log_", 4)) {
759         kernel_logger();
760         base = "/dev/log/";
761         make_dir(base, 0755);
762         name += 4;
763     } else
764         base = "/dev/";
765     links = get_character_device_symlinks(uevent);
766
767     if (!devpath[0])
768         snprintf(devpath, sizeof(devpath), "%s%s", base, name);
769
770     handle_device(uevent->action, devpath, uevent->path, 0,
771             uevent->major, uevent->minor, links);
772}
773
774static void handle_device_event(struct uevent *uevent)
775{
776    if (!strcmp(uevent->action,"add") || !strcmp(uevent->action, "change") || !strcmp(uevent->action, "online"))
777        fixup_sys_perms(uevent->path);
778
779    if (!strncmp(uevent->subsystem, "block", 5)) {
780        handle_block_device_event(uevent);
781    } else if (!strncmp(uevent->subsystem, "platform", 8)) {
782        handle_platform_device_event(uevent);
783    } else {
784        handle_generic_device_event(uevent);
785    }
786}
787
788static int load_firmware(int fw_fd, int loading_fd, int data_fd)
789{
790    struct stat st;
791    long len_to_copy;
792    int ret = 0;
793
794    if(fstat(fw_fd, &st) < 0)
795        return -1;
796    len_to_copy = st.st_size;
797
798    write(loading_fd, "1", 1);  /* start transfer */
799
800    while (len_to_copy > 0) {
801        char buf[PAGE_SIZE];
802        ssize_t nr;
803
804        nr = read(fw_fd, buf, sizeof(buf));
805        if(!nr)
806            break;
807        if(nr < 0) {
808            ret = -1;
809            break;
810        }
811
812        len_to_copy -= nr;
813        while (nr > 0) {
814            ssize_t nw = 0;
815
816            nw = write(data_fd, buf + nw, nr);
817            if(nw <= 0) {
818                ret = -1;
819                goto out;
820            }
821            nr -= nw;
822        }
823    }
824
825out:
826    if(!ret)
827        write(loading_fd, "0", 1);  /* successful end of transfer */
828    else
829        write(loading_fd, "-1", 2); /* abort transfer */
830
831    return ret;
832}
833
834static int is_booting(void)
835{
836    return access("/dev/.booting", F_OK) == 0;
837}
838
839static void process_firmware_event(struct uevent *uevent)
840{
841    char *root, *loading, *data, *file1 = NULL, *file2 = NULL, *file3 = NULL;
842    int l, loading_fd, data_fd, fw_fd;
843    int booting = is_booting();
844
845    INFO("firmware: loading '%s' for '%s'\n",
846         uevent->firmware, uevent->path);
847
848    l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path);
849    if (l == -1)
850        return;
851
852    l = asprintf(&loading, "%sloading", root);
853    if (l == -1)
854        goto root_free_out;
855
856    l = asprintf(&data, "%sdata", root);
857    if (l == -1)
858        goto loading_free_out;
859
860    l = asprintf(&file1, FIRMWARE_DIR1"/%s", uevent->firmware);
861    if (l == -1)
862        goto data_free_out;
863
864    l = asprintf(&file2, FIRMWARE_DIR2"/%s", uevent->firmware);
865    if (l == -1)
866        goto data_free_out;
867
868    l = asprintf(&file3, FIRMWARE_DIR3"/%s", uevent->firmware);
869    if (l == -1)
870        goto data_free_out;
871
872    loading_fd = open(loading, O_WRONLY);
873    if(loading_fd < 0)
874        goto file_free_out;
875
876    data_fd = open(data, O_WRONLY);
877    if(data_fd < 0)
878        goto loading_close_out;
879
880try_loading_again:
881    fw_fd = open(file1, O_RDONLY);
882    if(fw_fd < 0) {
883        fw_fd = open(file2, O_RDONLY);
884        if (fw_fd < 0) {
885            fw_fd = open(file3, O_RDONLY);
886            if (fw_fd < 0) {
887                if (booting) {
888                        /* If we're not fully booted, we may be missing
889                         * filesystems needed for firmware, wait and retry.
890                         */
891                    usleep(100000);
892                    booting = is_booting();
893                    goto try_loading_again;
894                }
895                INFO("firmware: could not open '%s' %d\n", uevent->firmware, errno);
896                write(loading_fd, "-1", 2);
897                goto data_close_out;
898            }
899        }
900    }
901
902    if(!load_firmware(fw_fd, loading_fd, data_fd))
903        INFO("firmware: copy success { '%s', '%s' }\n", root, uevent->firmware);
904    else
905        INFO("firmware: copy failure { '%s', '%s' }\n", root, uevent->firmware);
906
907    close(fw_fd);
908data_close_out:
909    close(data_fd);
910loading_close_out:
911    close(loading_fd);
912file_free_out:
913    free(file1);
914    free(file2);
915    free(file3);
916data_free_out:
917    free(data);
918loading_free_out:
919    free(loading);
920root_free_out:
921    free(root);
922}
923
924static void handle_firmware_event(struct uevent *uevent)
925{
926    pid_t pid;
927    int ret;
928
929    if(strcmp(uevent->subsystem, "firmware"))
930        return;
931
932    if(strcmp(uevent->action, "add"))
933        return;
934
935    /* we fork, to avoid making large memory allocations in init proper */
936    pid = fork();
937    if (!pid) {
938        process_firmware_event(uevent);
939        exit(EXIT_SUCCESS);
940    }
941}
942
943#define UEVENT_MSG_LEN  1024
944void handle_device_fd()
945{
946    char msg[UEVENT_MSG_LEN+2];
947    int n;
948    while ((n = uevent_kernel_multicast_recv(device_fd, msg, UEVENT_MSG_LEN)) > 0) {
949        if(n >= UEVENT_MSG_LEN)   /* overflow -- discard */
950            continue;
951
952        msg[n] = '\0';
953        msg[n+1] = '\0';
954
955        struct uevent uevent;
956        parse_event(msg, &uevent);
957
958        if (sehandle && selinux_status_updated() > 0) {
959            struct selabel_handle *sehandle2;
960            sehandle2 = selinux_android_file_context_handle();
961            if (sehandle2) {
962                selabel_close(sehandle);
963                sehandle = sehandle2;
964            }
965        }
966
967        handle_device_event(&uevent);
968        handle_firmware_event(&uevent);
969    }
970}
971
972/* Coldboot walks parts of the /sys tree and pokes the uevent files
973** to cause the kernel to regenerate device add events that happened
974** before init's device manager was started
975**
976** We drain any pending events from the netlink socket every time
977** we poke another uevent file to make sure we don't overrun the
978** socket's buffer.
979*/
980
981static void do_coldboot(DIR *d)
982{
983    struct dirent *de;
984    int dfd, fd;
985
986    dfd = dirfd(d);
987
988    fd = openat(dfd, "uevent", O_WRONLY);
989    if(fd >= 0) {
990        write(fd, "add\n", 4);
991        close(fd);
992        handle_device_fd();
993    }
994
995    while((de = readdir(d))) {
996        DIR *d2;
997
998        if(de->d_type != DT_DIR || de->d_name[0] == '.')
999            continue;
1000
1001        fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY);
1002        if(fd < 0)
1003            continue;
1004
1005        d2 = fdopendir(fd);
1006        if(d2 == 0)
1007            close(fd);
1008        else {
1009            do_coldboot(d2);
1010            closedir(d2);
1011        }
1012    }
1013}
1014
1015static void coldboot(const char *path)
1016{
1017    DIR *d = opendir(path);
1018    if(d) {
1019        do_coldboot(d);
1020        closedir(d);
1021    }
1022}
1023
1024void device_init(void)
1025{
1026    suseconds_t t0, t1;
1027    struct stat info;
1028    int fd;
1029
1030    sehandle = NULL;
1031    if (is_selinux_enabled() > 0) {
1032        sehandle = selinux_android_file_context_handle();
1033        selinux_status_open(true);
1034    }
1035
1036    /* is 256K enough? udev uses 16MB! */
1037    device_fd = uevent_open_socket(256*1024, true);
1038    if(device_fd < 0)
1039        return;
1040
1041    fcntl(device_fd, F_SETFD, FD_CLOEXEC);
1042    fcntl(device_fd, F_SETFL, O_NONBLOCK);
1043
1044    if (stat(coldboot_done, &info) < 0) {
1045        t0 = get_usecs();
1046        coldboot("/sys/class");
1047        coldboot("/sys/block");
1048        coldboot("/sys/devices");
1049        t1 = get_usecs();
1050        fd = open(coldboot_done, O_WRONLY|O_CREAT, 0000);
1051        close(fd);
1052        log_event_print("coldboot %ld uS\n", ((long) (t1 - t0)));
1053    } else {
1054        log_event_print("skipping coldboot, already done\n");
1055    }
1056}
1057
1058int get_device_fd()
1059{
1060    return device_fd;
1061}
1062