devices.c revision 3bc1e9cd7b2832d51c442c0342054e0235a383f6 
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 <stdio.h>
19#include <stdlib.h>
20#include <sys/stat.h>
21#include <sys/types.h>
22
23#include <fcntl.h>
24#include <dirent.h>
25#include <unistd.h>
26#include <string.h>
27
28#include <sys/socket.h>
29#include <sys/un.h>
30#include <linux/netlink.h>
31#include <private/android_filesystem_config.h>
32#include <sys/time.h>
33#include <asm/page.h>
34
35#include "init.h"
36#include "devices.h"
37
38#define CMDLINE_PREFIX  "/dev"
39#define SYSFS_PREFIX    "/sys"
40#define FIRMWARE_DIR    "/etc/firmware"
41#define MAX_QEMU_PERM 6
42
43struct uevent {
44    const char *action;
45    const char *path;
46    const char *subsystem;
47    const char *firmware;
48    int major;
49    int minor;
50};
51
52static int open_uevent_socket(void)
53{
54    struct sockaddr_nl addr;
55    int sz = 64*1024; // XXX larger? udev uses 16MB!
56    int s;
57
58    memset(&addr, 0, sizeof(addr));
59    addr.nl_family = AF_NETLINK;
60    addr.nl_pid = getpid();
61    addr.nl_groups = 0xffffffff;
62
63    s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
64    if(s < 0)
65        return -1;
66
67    setsockopt(s, SOL_SOCKET, SO_RCVBUFFORCE, &sz, sizeof(sz));
68
69    if(bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
70        close(s);
71        return -1;
72    }
73
74    return s;
75}
76
77struct perms_ {
78    char *name;
79    mode_t perm;
80    unsigned int uid;
81    unsigned int gid;
82    unsigned short prefix;
83};
84static struct perms_ devperms[] = {
85    { "/dev/null",          0666,   AID_ROOT,       AID_ROOT,       0 },
86    { "/dev/zero",          0666,   AID_ROOT,       AID_ROOT,       0 },
87    { "/dev/full",          0666,   AID_ROOT,       AID_ROOT,       0 },
88    { "/dev/ptmx",          0666,   AID_ROOT,       AID_ROOT,       0 },
89    { "/dev/tty",           0666,   AID_ROOT,       AID_ROOT,       0 },
90    { "/dev/random",        0666,   AID_ROOT,       AID_ROOT,       0 },
91    { "/dev/urandom",       0666,   AID_ROOT,       AID_ROOT,       0 },
92    { "/dev/ashmem",        0666,   AID_ROOT,       AID_ROOT,       0 },
93    { "/dev/binder",        0666,   AID_ROOT,       AID_ROOT,       0 },
94
95	    /* logger should be world writable (for logging) but not readable */
96    { "/dev/log/",          0662,   AID_ROOT,       AID_LOG,        1 },
97
98    /* the msm hw3d client device node is world writable/readable. */
99    { "/dev/msm_hw3dc",     0666,   AID_ROOT,       AID_ROOT,       0 },
100
101    /* gpu driver for adreno200 is globally accessible */
102    { "/dev/kgsl",          0666,   AID_ROOT,       AID_ROOT,       0 },
103
104        /* these should not be world writable */
105    { "/dev/diag",          0660,   AID_RADIO,      AID_RADIO,        0 },
106    { "/dev/diag_arm9",     0660,   AID_RADIO,      AID_RADIO,        0 },
107    { "/dev/android_adb",   0660,   AID_ADB,        AID_ADB,        0 },
108    { "/dev/android_adb_enable",   0660,   AID_ADB,        AID_ADB,        0 },
109    { "/dev/ttyMSM0",       0600,   AID_BLUETOOTH,  AID_BLUETOOTH,  0 },
110    { "/dev/ttyHS0",        0600,   AID_BLUETOOTH,  AID_BLUETOOTH,  0 },
111    { "/dev/uinput",        0660,   AID_SYSTEM,     AID_BLUETOOTH,  0 },
112    { "/dev/alarm",         0664,   AID_SYSTEM,     AID_RADIO,      0 },
113    { "/dev/tty0",          0660,   AID_ROOT,       AID_SYSTEM,     0 },
114    { "/dev/graphics/",     0660,   AID_ROOT,       AID_GRAPHICS,   1 },
115    { "/dev/msm_hw3dm",     0660,   AID_SYSTEM,     AID_GRAPHICS,   0 },
116    { "/dev/input/",        0660,   AID_ROOT,       AID_INPUT,      1 },
117    { "/dev/eac",           0660,   AID_ROOT,       AID_AUDIO,      0 },
118    { "/dev/cam",           0660,   AID_ROOT,       AID_CAMERA,     0 },
119    { "/dev/pmem",          0660,   AID_SYSTEM,     AID_GRAPHICS,   0 },
120    { "/dev/pmem_gpu",      0660,   AID_SYSTEM,     AID_GRAPHICS,   1 },
121    { "/dev/pmem_adsp",     0660,   AID_SYSTEM,     AID_AUDIO,      1 },
122    { "/dev/pmem_camera",   0660,   AID_SYSTEM,     AID_CAMERA,     1 },
123    { "/dev/oncrpc/",       0660,   AID_ROOT,       AID_SYSTEM,     1 },
124    { "/dev/adsp/",         0660,   AID_SYSTEM,     AID_AUDIO,      1 },
125    { "/dev/mt9t013",       0660,   AID_SYSTEM,     AID_SYSTEM,     0 },
126    { "/dev/msm_camera/",   0660,   AID_SYSTEM,     AID_SYSTEM,     1 },
127    { "/dev/akm8976_daemon",0640,   AID_COMPASS,    AID_SYSTEM,     0 },
128    { "/dev/akm8976_aot",   0640,   AID_COMPASS,    AID_SYSTEM,     0 },
129    { "/dev/akm8973_daemon",0640,   AID_COMPASS,    AID_SYSTEM,     0 },
130    { "/dev/akm8973_aot",   0640,   AID_COMPASS,    AID_SYSTEM,     0 },
131    { "/dev/bma150",        0640,   AID_COMPASS,    AID_SYSTEM,     0 },
132    { "/dev/cm3602",        0640,   AID_COMPASS,    AID_SYSTEM,     0 },
133    { "/dev/akm8976_pffd",  0640,   AID_COMPASS,    AID_SYSTEM,     0 },
134    { "/dev/lightsensor",   0640,   AID_SYSTEM,     AID_SYSTEM,     0 },
135    { "/dev/msm_pcm_out",   0660,   AID_SYSTEM,     AID_AUDIO,      1 },
136    { "/dev/msm_pcm_in",    0660,   AID_SYSTEM,     AID_AUDIO,      1 },
137    { "/dev/msm_pcm_ctl",   0660,   AID_SYSTEM,     AID_AUDIO,      1 },
138    { "/dev/msm_snd",       0660,   AID_SYSTEM,     AID_AUDIO,      1 },
139    { "/dev/msm_mp3",       0660,   AID_SYSTEM,     AID_AUDIO,      1 },
140    { "/dev/msm_audpre",    0660,   AID_SYSTEM,     AID_AUDIO,      0 },
141    { "/dev/htc-acoustic",  0660,   AID_SYSTEM,     AID_AUDIO,      0 },
142    { "/dev/snd/dsp",       0660,   AID_SYSTEM,     AID_AUDIO,      0 },
143    { "/dev/snd/dsp1",      0660,   AID_SYSTEM,     AID_AUDIO,      0 },
144    { "/dev/snd/mixer",     0660,   AID_SYSTEM,     AID_AUDIO,      0 },
145    { "/dev/smd0",          0640,   AID_RADIO,      AID_RADIO,      0 },
146    { "/dev/qemu_trace",    0666,   AID_SYSTEM,     AID_SYSTEM,     0 },
147    { "/dev/qmi",           0640,   AID_RADIO,      AID_RADIO,      0 },
148    { "/dev/qmi0",          0640,   AID_RADIO,      AID_RADIO,      0 },
149    { "/dev/qmi1",          0640,   AID_RADIO,      AID_RADIO,      0 },
150    { "/dev/qmi2",          0640,   AID_RADIO,      AID_RADIO,      0 },
151        /* CDMA radio interface MUX */
152    { "/dev/ts0710mux",     0640,   AID_RADIO,      AID_RADIO,      1 },
153    { "/dev/ppp",           0660,   AID_RADIO,      AID_VPN,        0 },
154    { "/dev/tun",           0640,   AID_VPN,        AID_VPN,        0 },
155    { NULL, 0, 0, 0, 0 },
156};
157
158/* devperms_partners list and perm_node are for hardware specific /dev entries */
159struct perm_node {
160    struct perms_ dp;
161    struct listnode plist;
162};
163list_declare(devperms_partners);
164
165/*
166 * Permission override when in emulator mode, must be parsed before
167 * system properties is initalized.
168 */
169static int qemu_perm_count;
170static struct perms_ qemu_perms[MAX_QEMU_PERM + 1];
171
172int add_devperms_partners(const char *name, mode_t perm, unsigned int uid,
173                        unsigned int gid, unsigned short prefix) {
174    int size;
175    struct perm_node *node = malloc(sizeof (struct perm_node));
176    if (!node)
177        return -ENOMEM;
178
179    size = strlen(name) + 1;
180    if ((node->dp.name = malloc(size)) == NULL)
181        return -ENOMEM;
182
183    memcpy(node->dp.name, name, size);
184    node->dp.perm = perm;
185    node->dp.uid = uid;
186    node->dp.gid = gid;
187    node->dp.prefix = prefix;
188
189    list_add_tail(&devperms_partners, &node->plist);
190    return 0;
191}
192
193void qemu_init(void) {
194    qemu_perm_count = 0;
195    memset(&qemu_perms, 0, sizeof(qemu_perms));
196}
197
198static int qemu_perm(const char* name, mode_t perm, unsigned int uid,
199                         unsigned int gid, unsigned short prefix)
200{
201    char *buf;
202    if (qemu_perm_count == MAX_QEMU_PERM)
203        return -ENOSPC;
204
205    buf = malloc(strlen(name) + 1);
206    if (!buf)
207        return -errno;
208
209    strlcpy(buf, name, strlen(name) + 1);
210    qemu_perms[qemu_perm_count].name = buf;
211    qemu_perms[qemu_perm_count].perm = perm;
212    qemu_perms[qemu_perm_count].uid = uid;
213    qemu_perms[qemu_perm_count].gid = gid;
214    qemu_perms[qemu_perm_count].prefix = prefix;
215
216    qemu_perm_count++;
217    return 0;
218}
219
220/* Permission overrides for emulator that are parsed from /proc/cmdline. */
221void qemu_cmdline(const char* name, const char *value)
222{
223    char *buf;
224    if (!strcmp(name, "android.ril")) {
225        /* cmd line params currently assume /dev/ prefix */
226        if (asprintf(&buf, CMDLINE_PREFIX"/%s", value) == -1) {
227            return;
228        }
229        INFO("nani- buf:: %s\n", buf);
230        qemu_perm(buf, 0660, AID_RADIO, AID_ROOT, 0);
231    }
232}
233
234static int get_device_perm_inner(struct perms_ *perms, const char *path,
235                                    unsigned *uid, unsigned *gid, mode_t *perm)
236{
237    int i;
238    for(i = 0; perms[i].name; i++) {
239
240        if(perms[i].prefix) {
241            if(strncmp(path, perms[i].name, strlen(perms[i].name)))
242                continue;
243        } else {
244            if(strcmp(path, perms[i].name))
245                continue;
246        }
247        *uid = perms[i].uid;
248        *gid = perms[i].gid;
249        *perm = perms[i].perm;
250        return 0;
251    }
252    return -1;
253}
254
255/* First checks for emulator specific permissions specified in /proc/cmdline. */
256static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid)
257{
258    mode_t perm;
259
260    if (get_device_perm_inner(qemu_perms, path, uid, gid, &perm) == 0) {
261        return perm;
262    } else if (get_device_perm_inner(devperms, path, uid, gid, &perm) == 0) {
263        return perm;
264    } else {
265        struct listnode *node;
266        struct perm_node *perm_node;
267        struct perms_ *dp;
268
269        /* Check partners list. */
270        list_for_each(node, &devperms_partners) {
271            perm_node = node_to_item(node, struct perm_node, plist);
272            dp = &perm_node->dp;
273
274            if (dp->prefix) {
275                if (strncmp(path, dp->name, strlen(dp->name)))
276                    continue;
277            } else {
278                if (strcmp(path, dp->name))
279                    continue;
280            }
281            /* Found perm in partner list. */
282            *uid = dp->uid;
283            *gid = dp->gid;
284            return dp->perm;
285        }
286        /* Default if nothing found. */
287        *uid = 0;
288        *gid = 0;
289        return 0600;
290    }
291}
292
293static void make_device(const char *path, int block, int major, int minor)
294{
295    unsigned uid;
296    unsigned gid;
297    mode_t mode;
298    dev_t dev;
299
300    if(major > 255 || minor > 255)
301        return;
302
303    mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR);
304    dev = (major << 8) | minor;
305    mknod(path, mode, dev);
306    chown(path, uid, gid);
307}
308
309#ifdef LOG_UEVENTS
310
311static inline suseconds_t get_usecs(void)
312{
313    struct timeval tv;
314    gettimeofday(&tv, 0);
315    return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec;
316}
317
318#define log_event_print(x...) INFO(x)
319
320#else
321
322#define log_event_print(fmt, args...)   do { } while (0)
323#define get_usecs()                     0
324
325#endif
326
327static void parse_event(const char *msg, struct uevent *uevent)
328{
329    uevent->action = "";
330    uevent->path = "";
331    uevent->subsystem = "";
332    uevent->firmware = "";
333    uevent->major = -1;
334    uevent->minor = -1;
335
336        /* currently ignoring SEQNUM */
337    while(*msg) {
338        if(!strncmp(msg, "ACTION=", 7)) {
339            msg += 7;
340            uevent->action = msg;
341        } else if(!strncmp(msg, "DEVPATH=", 8)) {
342            msg += 8;
343            uevent->path = msg;
344        } else if(!strncmp(msg, "SUBSYSTEM=", 10)) {
345            msg += 10;
346            uevent->subsystem = msg;
347        } else if(!strncmp(msg, "FIRMWARE=", 9)) {
348            msg += 9;
349            uevent->firmware = msg;
350        } else if(!strncmp(msg, "MAJOR=", 6)) {
351            msg += 6;
352            uevent->major = atoi(msg);
353        } else if(!strncmp(msg, "MINOR=", 6)) {
354            msg += 6;
355            uevent->minor = atoi(msg);
356        }
357
358            /* advance to after the next \0 */
359        while(*msg++)
360            ;
361    }
362
363    log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n",
364                    uevent->action, uevent->path, uevent->subsystem,
365                    uevent->firmware, uevent->major, uevent->minor);
366}
367
368static void handle_device_event(struct uevent *uevent)
369{
370    char devpath[96];
371    char *base, *name;
372    int block;
373
374        /* if it's not a /dev device, nothing to do */
375    if((uevent->major < 0) || (uevent->minor < 0))
376        return;
377
378        /* do we have a name? */
379    name = strrchr(uevent->path, '/');
380    if(!name)
381        return;
382    name++;
383
384        /* too-long names would overrun our buffer */
385    if(strlen(name) > 64)
386        return;
387
388        /* are we block or char? where should we live? */
389    if(!strncmp(uevent->subsystem, "block", 5)) {
390        block = 1;
391        base = "/dev/block/";
392        mkdir(base, 0755);
393    } else {
394        block = 0;
395            /* this should probably be configurable somehow */
396        if(!strncmp(uevent->subsystem, "graphics", 8)) {
397            base = "/dev/graphics/";
398            mkdir(base, 0755);
399        } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) {
400            base = "/dev/oncrpc/";
401            mkdir(base, 0755);
402        } else if (!strncmp(uevent->subsystem, "adsp", 4)) {
403            base = "/dev/adsp/";
404            mkdir(base, 0755);
405        } else if (!strncmp(uevent->subsystem, "msm_camera", 10)) {
406            base = "/dev/msm_camera/";
407            mkdir(base, 0755);
408        } else if(!strncmp(uevent->subsystem, "input", 5)) {
409            base = "/dev/input/";
410            mkdir(base, 0755);
411        } else if(!strncmp(uevent->subsystem, "mtd", 3)) {
412            base = "/dev/mtd/";
413            mkdir(base, 0755);
414        } else if(!strncmp(uevent->subsystem, "sound", 5)) {
415            base = "/dev/snd/";
416            mkdir(base, 0755);
417        } else if(!strncmp(uevent->subsystem, "misc", 4) &&
418                    !strncmp(name, "log_", 4)) {
419            base = "/dev/log/";
420            mkdir(base, 0755);
421            name += 4;
422        } else
423            base = "/dev/";
424    }
425
426    snprintf(devpath, sizeof(devpath), "%s%s", base, name);
427
428    if(!strcmp(uevent->action, "add")) {
429        make_device(devpath, block, uevent->major, uevent->minor);
430        return;
431    }
432
433    if(!strcmp(uevent->action, "remove")) {
434        unlink(devpath);
435        return;
436    }
437}
438
439static int load_firmware(int fw_fd, int loading_fd, int data_fd)
440{
441    struct stat st;
442    long len_to_copy;
443    int ret = 0;
444
445    if(fstat(fw_fd, &st) < 0)
446        return -1;
447    len_to_copy = st.st_size;
448
449    write(loading_fd, "1", 1);  /* start transfer */
450
451    while (len_to_copy > 0) {
452        char buf[PAGE_SIZE];
453        ssize_t nr;
454
455        nr = read(fw_fd, buf, sizeof(buf));
456        if(!nr)
457            break;
458        if(nr < 0) {
459            ret = -1;
460            break;
461        }
462
463        len_to_copy -= nr;
464        while (nr > 0) {
465            ssize_t nw = 0;
466
467            nw = write(data_fd, buf + nw, nr);
468            if(nw <= 0) {
469                ret = -1;
470                goto out;
471            }
472            nr -= nw;
473        }
474    }
475
476out:
477    if(!ret)
478        write(loading_fd, "0", 1);  /* successful end of transfer */
479    else
480        write(loading_fd, "-1", 2); /* abort transfer */
481
482    return ret;
483}
484
485static void process_firmware_event(struct uevent *uevent)
486{
487    char *root, *loading, *data, *file;
488    int l, loading_fd, data_fd, fw_fd;
489
490    log_event_print("firmware event { '%s', '%s' }\n",
491                    uevent->path, uevent->firmware);
492
493    l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path);
494    if (l == -1)
495        return;
496
497    l = asprintf(&loading, "%sloading", root);
498    if (l == -1)
499        goto root_free_out;
500
501    l = asprintf(&data, "%sdata", root);
502    if (l == -1)
503        goto loading_free_out;
504
505    l = asprintf(&file, FIRMWARE_DIR"/%s", uevent->firmware);
506    if (l == -1)
507        goto data_free_out;
508
509    loading_fd = open(loading, O_WRONLY);
510    if(loading_fd < 0)
511        goto file_free_out;
512
513    data_fd = open(data, O_WRONLY);
514    if(data_fd < 0)
515        goto loading_close_out;
516
517    fw_fd = open(file, O_RDONLY);
518    if(fw_fd < 0)
519        goto data_close_out;
520
521    if(!load_firmware(fw_fd, loading_fd, data_fd))
522        log_event_print("firmware copy success { '%s', '%s' }\n", root, file);
523    else
524        log_event_print("firmware copy failure { '%s', '%s' }\n", root, file);
525
526    close(fw_fd);
527data_close_out:
528    close(data_fd);
529loading_close_out:
530    close(loading_fd);
531file_free_out:
532    free(file);
533data_free_out:
534    free(data);
535loading_free_out:
536    free(loading);
537root_free_out:
538    free(root);
539}
540
541static void handle_firmware_event(struct uevent *uevent)
542{
543    pid_t pid;
544
545    if(strcmp(uevent->subsystem, "firmware"))
546        return;
547
548    if(strcmp(uevent->action, "add"))
549        return;
550
551    /* we fork, to avoid making large memory allocations in init proper */
552    pid = fork();
553    if (!pid) {
554        process_firmware_event(uevent);
555        exit(EXIT_SUCCESS);
556    }
557}
558
559#define UEVENT_MSG_LEN  1024
560void handle_device_fd(int fd)
561{
562    char msg[UEVENT_MSG_LEN+2];
563    int n;
564
565    while((n = recv(fd, msg, UEVENT_MSG_LEN, 0)) > 0) {
566        struct uevent uevent;
567
568        if(n == UEVENT_MSG_LEN)   /* overflow -- discard */
569            continue;
570
571        msg[n] = '\0';
572        msg[n+1] = '\0';
573
574        parse_event(msg, &uevent);
575
576        handle_device_event(&uevent);
577        handle_firmware_event(&uevent);
578    }
579}
580
581/* Coldboot walks parts of the /sys tree and pokes the uevent files
582** to cause the kernel to regenerate device add events that happened
583** before init's device manager was started
584**
585** We drain any pending events from the netlink socket every time
586** we poke another uevent file to make sure we don't overrun the
587** socket's buffer.
588*/
589
590static void do_coldboot(int event_fd, DIR *d)
591{
592    struct dirent *de;
593    int dfd, fd;
594
595    dfd = dirfd(d);
596
597    fd = openat(dfd, "uevent", O_WRONLY);
598    if(fd >= 0) {
599        write(fd, "add\n", 4);
600        close(fd);
601        handle_device_fd(event_fd);
602    }
603
604    while((de = readdir(d))) {
605        DIR *d2;
606
607        if(de->d_type != DT_DIR || de->d_name[0] == '.')
608            continue;
609
610        fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY);
611        if(fd < 0)
612            continue;
613
614        d2 = fdopendir(fd);
615        if(d2 == 0)
616            close(fd);
617        else {
618            do_coldboot(event_fd, d2);
619            closedir(d2);
620        }
621    }
622}
623
624static void coldboot(int event_fd, const char *path)
625{
626    DIR *d = opendir(path);
627    if(d) {
628        do_coldboot(event_fd, d);
629        closedir(d);
630    }
631}
632
633int device_init(void)
634{
635    suseconds_t t0, t1;
636    int fd;
637
638    fd = open_uevent_socket();
639    if(fd < 0)
640        return -1;
641
642    fcntl(fd, F_SETFD, FD_CLOEXEC);
643    fcntl(fd, F_SETFL, O_NONBLOCK);
644
645    t0 = get_usecs();
646    coldboot(fd, "/sys/class");
647    coldboot(fd, "/sys/block");
648    coldboot(fd, "/sys/devices");
649    t1 = get_usecs();
650
651    log_event_print("coldboot %ld uS\n", ((long) (t1 - t0)));
652
653    return fd;
654}
655