devices.c revision 37b210f56036cda41b0407e841fe79fb4db310fc 
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/msm_pcm_out",   0660,   AID_SYSTEM,     AID_AUDIO,      1 },
135    { "/dev/msm_pcm_in",    0660,   AID_SYSTEM,     AID_AUDIO,      1 },
136    { "/dev/msm_pcm_ctl",   0660,   AID_SYSTEM,     AID_AUDIO,      1 },
137    { "/dev/msm_snd",       0660,   AID_SYSTEM,     AID_AUDIO,      1 },
138    { "/dev/msm_mp3",       0660,   AID_SYSTEM,     AID_AUDIO,      1 },
139    { "/dev/msm_audpre",    0660,   AID_SYSTEM,     AID_AUDIO,      0 },
140    { "/dev/htc-acoustic",  0660,   AID_SYSTEM,     AID_AUDIO,      0 },
141    { "/dev/snd/dsp",       0660,   AID_SYSTEM,     AID_AUDIO,      0 },
142    { "/dev/snd/dsp1",      0660,   AID_SYSTEM,     AID_AUDIO,      0 },
143    { "/dev/snd/mixer",     0660,   AID_SYSTEM,     AID_AUDIO,      0 },
144    { "/dev/smd0",          0640,   AID_RADIO,      AID_RADIO,      0 },
145    { "/dev/qemu_trace",    0666,   AID_SYSTEM,     AID_SYSTEM,     0 },
146    { "/dev/qmi",           0640,   AID_RADIO,      AID_RADIO,      0 },
147    { "/dev/qmi0",          0640,   AID_RADIO,      AID_RADIO,      0 },
148    { "/dev/qmi1",          0640,   AID_RADIO,      AID_RADIO,      0 },
149    { "/dev/qmi2",          0640,   AID_RADIO,      AID_RADIO,      0 },
150        /* CDMA radio interface MUX */
151    { "/dev/ts0710mux",     0640,   AID_RADIO,      AID_RADIO,      1 },
152    { "/dev/ppp",           0660,   AID_RADIO,      AID_VPN,        0 },
153    { "/dev/tun",           0640,   AID_VPN,        AID_VPN,        0 },
154    { NULL, 0, 0, 0, 0 },
155};
156
157/* devperms_partners list and perm_node are for hardware specific /dev entries */
158struct perm_node {
159    struct perms_ dp;
160    struct listnode plist;
161};
162list_declare(devperms_partners);
163
164/*
165 * Permission override when in emulator mode, must be parsed before
166 * system properties is initalized.
167 */
168static int qemu_perm_count;
169static struct perms_ qemu_perms[MAX_QEMU_PERM + 1];
170
171int add_devperms_partners(const char *name, mode_t perm, unsigned int uid,
172                        unsigned int gid, unsigned short prefix) {
173    int size;
174    struct perm_node *node = malloc(sizeof (struct perm_node));
175    if (!node)
176        return -ENOMEM;
177
178    size = strlen(name) + 1;
179    if ((node->dp.name = malloc(size)) == NULL)
180        return -ENOMEM;
181
182    memcpy(node->dp.name, name, size);
183    node->dp.perm = perm;
184    node->dp.uid = uid;
185    node->dp.gid = gid;
186    node->dp.prefix = prefix;
187
188    list_add_tail(&devperms_partners, &node->plist);
189    return 0;
190}
191
192void qemu_init(void) {
193    qemu_perm_count = 0;
194    memset(&qemu_perms, 0, sizeof(qemu_perms));
195}
196
197static int qemu_perm(const char* name, mode_t perm, unsigned int uid,
198                         unsigned int gid, unsigned short prefix)
199{
200    char *buf;
201    if (qemu_perm_count == MAX_QEMU_PERM)
202        return -ENOSPC;
203
204    buf = malloc(strlen(name) + 1);
205    if (!buf)
206        return -errno;
207
208    strlcpy(buf, name, strlen(name) + 1);
209    qemu_perms[qemu_perm_count].name = buf;
210    qemu_perms[qemu_perm_count].perm = perm;
211    qemu_perms[qemu_perm_count].uid = uid;
212    qemu_perms[qemu_perm_count].gid = gid;
213    qemu_perms[qemu_perm_count].prefix = prefix;
214
215    qemu_perm_count++;
216    return 0;
217}
218
219/* Permission overrides for emulator that are parsed from /proc/cmdline. */
220void qemu_cmdline(const char* name, const char *value)
221{
222    char *buf;
223    if (!strcmp(name, "android.ril")) {
224        /* cmd line params currently assume /dev/ prefix */
225        if (asprintf(&buf, CMDLINE_PREFIX"/%s", value) == -1) {
226            return;
227        }
228        INFO("nani- buf:: %s\n", buf);
229        qemu_perm(buf, 0660, AID_RADIO, AID_ROOT, 0);
230    }
231}
232
233static int get_device_perm_inner(struct perms_ *perms, const char *path,
234                                    unsigned *uid, unsigned *gid, mode_t *perm)
235{
236    int i;
237    for(i = 0; perms[i].name; i++) {
238
239        if(perms[i].prefix) {
240            if(strncmp(path, perms[i].name, strlen(perms[i].name)))
241                continue;
242        } else {
243            if(strcmp(path, perms[i].name))
244                continue;
245        }
246        *uid = perms[i].uid;
247        *gid = perms[i].gid;
248        *perm = perms[i].perm;
249        return 0;
250    }
251    return -1;
252}
253
254/* First checks for emulator specific permissions specified in /proc/cmdline. */
255static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid)
256{
257    mode_t perm;
258
259    if (get_device_perm_inner(qemu_perms, path, uid, gid, &perm) == 0) {
260        return perm;
261    } else if (get_device_perm_inner(devperms, path, uid, gid, &perm) == 0) {
262        return perm;
263    } else {
264        struct listnode *node;
265        struct perm_node *perm_node;
266        struct perms_ *dp;
267
268        /* Check partners list. */
269        list_for_each(node, &devperms_partners) {
270            perm_node = node_to_item(node, struct perm_node, plist);
271            dp = &perm_node->dp;
272
273            if (dp->prefix) {
274                if (strncmp(path, dp->name, strlen(dp->name)))
275                    continue;
276            } else {
277                if (strcmp(path, dp->name))
278                    continue;
279            }
280            /* Found perm in partner list. */
281            *uid = dp->uid;
282            *gid = dp->gid;
283            return dp->perm;
284        }
285        /* Default if nothing found. */
286        *uid = 0;
287        *gid = 0;
288        return 0600;
289    }
290}
291
292static void make_device(const char *path, int block, int major, int minor)
293{
294    unsigned uid;
295    unsigned gid;
296    mode_t mode;
297    dev_t dev;
298
299    if(major > 255 || minor > 255)
300        return;
301
302    mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR);
303    dev = (major << 8) | minor;
304    mknod(path, mode, dev);
305    chown(path, uid, gid);
306}
307
308#ifdef LOG_UEVENTS
309
310static inline suseconds_t get_usecs(void)
311{
312    struct timeval tv;
313    gettimeofday(&tv, 0);
314    return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec;
315}
316
317#define log_event_print(x...) INFO(x)
318
319#else
320
321#define log_event_print(fmt, args...)   do { } while (0)
322#define get_usecs()                     0
323
324#endif
325
326static void parse_event(const char *msg, struct uevent *uevent)
327{
328    uevent->action = "";
329    uevent->path = "";
330    uevent->subsystem = "";
331    uevent->firmware = "";
332    uevent->major = -1;
333    uevent->minor = -1;
334
335        /* currently ignoring SEQNUM */
336    while(*msg) {
337        if(!strncmp(msg, "ACTION=", 7)) {
338            msg += 7;
339            uevent->action = msg;
340        } else if(!strncmp(msg, "DEVPATH=", 8)) {
341            msg += 8;
342            uevent->path = msg;
343        } else if(!strncmp(msg, "SUBSYSTEM=", 10)) {
344            msg += 10;
345            uevent->subsystem = msg;
346        } else if(!strncmp(msg, "FIRMWARE=", 9)) {
347            msg += 9;
348            uevent->firmware = msg;
349        } else if(!strncmp(msg, "MAJOR=", 6)) {
350            msg += 6;
351            uevent->major = atoi(msg);
352        } else if(!strncmp(msg, "MINOR=", 6)) {
353            msg += 6;
354            uevent->minor = atoi(msg);
355        }
356
357            /* advance to after the next \0 */
358        while(*msg++)
359            ;
360    }
361
362    log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n",
363                    uevent->action, uevent->path, uevent->subsystem,
364                    uevent->firmware, uevent->major, uevent->minor);
365}
366
367static void handle_device_event(struct uevent *uevent)
368{
369    char devpath[96];
370    char *base, *name;
371    int block;
372
373        /* if it's not a /dev device, nothing to do */
374    if((uevent->major < 0) || (uevent->minor < 0))
375        return;
376
377        /* do we have a name? */
378    name = strrchr(uevent->path, '/');
379    if(!name)
380        return;
381    name++;
382
383        /* too-long names would overrun our buffer */
384    if(strlen(name) > 64)
385        return;
386
387        /* are we block or char? where should we live? */
388    if(!strncmp(uevent->subsystem, "block", 5)) {
389        block = 1;
390        base = "/dev/block/";
391        mkdir(base, 0755);
392    } else {
393        block = 0;
394            /* this should probably be configurable somehow */
395        if(!strncmp(uevent->subsystem, "graphics", 8)) {
396            base = "/dev/graphics/";
397            mkdir(base, 0755);
398        } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) {
399            base = "/dev/oncrpc/";
400            mkdir(base, 0755);
401        } else if (!strncmp(uevent->subsystem, "adsp", 4)) {
402            base = "/dev/adsp/";
403            mkdir(base, 0755);
404        } else if (!strncmp(uevent->subsystem, "msm_camera", 10)) {
405            base = "/dev/msm_camera/";
406            mkdir(base, 0755);
407        } else if(!strncmp(uevent->subsystem, "input", 5)) {
408            base = "/dev/input/";
409            mkdir(base, 0755);
410        } else if(!strncmp(uevent->subsystem, "mtd", 3)) {
411            base = "/dev/mtd/";
412            mkdir(base, 0755);
413        } else if(!strncmp(uevent->subsystem, "sound", 5)) {
414            base = "/dev/snd/";
415            mkdir(base, 0755);
416        } else if(!strncmp(uevent->subsystem, "misc", 4) &&
417                    !strncmp(name, "log_", 4)) {
418            base = "/dev/log/";
419            mkdir(base, 0755);
420            name += 4;
421        } else
422            base = "/dev/";
423    }
424
425    snprintf(devpath, sizeof(devpath), "%s%s", base, name);
426
427    if(!strcmp(uevent->action, "add")) {
428        make_device(devpath, block, uevent->major, uevent->minor);
429        return;
430    }
431
432    if(!strcmp(uevent->action, "remove")) {
433        unlink(devpath);
434        return;
435    }
436}
437
438static int load_firmware(int fw_fd, int loading_fd, int data_fd)
439{
440    struct stat st;
441    long len_to_copy;
442    int ret = 0;
443
444    if(fstat(fw_fd, &st) < 0)
445        return -1;
446    len_to_copy = st.st_size;
447
448    write(loading_fd, "1", 1);  /* start transfer */
449
450    while (len_to_copy > 0) {
451        char buf[PAGE_SIZE];
452        ssize_t nr;
453
454        nr = read(fw_fd, buf, sizeof(buf));
455        if(!nr)
456            break;
457        if(nr < 0) {
458            ret = -1;
459            break;
460        }
461
462        len_to_copy -= nr;
463        while (nr > 0) {
464            ssize_t nw = 0;
465
466            nw = write(data_fd, buf + nw, nr);
467            if(nw <= 0) {
468                ret = -1;
469                goto out;
470            }
471            nr -= nw;
472        }
473    }
474
475out:
476    if(!ret)
477        write(loading_fd, "0", 1);  /* successful end of transfer */
478    else
479        write(loading_fd, "-1", 2); /* abort transfer */
480
481    return ret;
482}
483
484static void process_firmware_event(struct uevent *uevent)
485{
486    char *root, *loading, *data, *file;
487    int l, loading_fd, data_fd, fw_fd;
488
489    log_event_print("firmware event { '%s', '%s' }\n",
490                    uevent->path, uevent->firmware);
491
492    l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path);
493    if (l == -1)
494        return;
495
496    l = asprintf(&loading, "%sloading", root);
497    if (l == -1)
498        goto root_free_out;
499
500    l = asprintf(&data, "%sdata", root);
501    if (l == -1)
502        goto loading_free_out;
503
504    l = asprintf(&file, FIRMWARE_DIR"/%s", uevent->firmware);
505    if (l == -1)
506        goto data_free_out;
507
508    loading_fd = open(loading, O_WRONLY);
509    if(loading_fd < 0)
510        goto file_free_out;
511
512    data_fd = open(data, O_WRONLY);
513    if(data_fd < 0)
514        goto loading_close_out;
515
516    fw_fd = open(file, O_RDONLY);
517    if(fw_fd < 0)
518        goto data_close_out;
519
520    if(!load_firmware(fw_fd, loading_fd, data_fd))
521        log_event_print("firmware copy success { '%s', '%s' }\n", root, file);
522    else
523        log_event_print("firmware copy failure { '%s', '%s' }\n", root, file);
524
525    close(fw_fd);
526data_close_out:
527    close(data_fd);
528loading_close_out:
529    close(loading_fd);
530file_free_out:
531    free(file);
532data_free_out:
533    free(data);
534loading_free_out:
535    free(loading);
536root_free_out:
537    free(root);
538}
539
540static void handle_firmware_event(struct uevent *uevent)
541{
542    pid_t pid;
543
544    if(strcmp(uevent->subsystem, "firmware"))
545        return;
546
547    if(strcmp(uevent->action, "add"))
548        return;
549
550    /* we fork, to avoid making large memory allocations in init proper */
551    pid = fork();
552    if (!pid) {
553        process_firmware_event(uevent);
554        exit(EXIT_SUCCESS);
555    }
556}
557
558#define UEVENT_MSG_LEN  1024
559void handle_device_fd(int fd)
560{
561    char msg[UEVENT_MSG_LEN+2];
562    int n;
563
564    while((n = recv(fd, msg, UEVENT_MSG_LEN, 0)) > 0) {
565        struct uevent uevent;
566
567        if(n == UEVENT_MSG_LEN)   /* overflow -- discard */
568            continue;
569
570        msg[n] = '\0';
571        msg[n+1] = '\0';
572
573        parse_event(msg, &uevent);
574
575        handle_device_event(&uevent);
576        handle_firmware_event(&uevent);
577    }
578}
579
580/* Coldboot walks parts of the /sys tree and pokes the uevent files
581** to cause the kernel to regenerate device add events that happened
582** before init's device manager was started
583**
584** We drain any pending events from the netlink socket every time
585** we poke another uevent file to make sure we don't overrun the
586** socket's buffer.
587*/
588
589static void do_coldboot(int event_fd, DIR *d)
590{
591    struct dirent *de;
592    int dfd, fd;
593
594    dfd = dirfd(d);
595
596    fd = openat(dfd, "uevent", O_WRONLY);
597    if(fd >= 0) {
598        write(fd, "add\n", 4);
599        close(fd);
600        handle_device_fd(event_fd);
601    }
602
603    while((de = readdir(d))) {
604        DIR *d2;
605
606        if(de->d_type != DT_DIR || de->d_name[0] == '.')
607            continue;
608
609        fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY);
610        if(fd < 0)
611            continue;
612
613        d2 = fdopendir(fd);
614        if(d2 == 0)
615            close(fd);
616        else {
617            do_coldboot(event_fd, d2);
618            closedir(d2);
619        }
620    }
621}
622
623static void coldboot(int event_fd, const char *path)
624{
625    DIR *d = opendir(path);
626    if(d) {
627        do_coldboot(event_fd, d);
628        closedir(d);
629    }
630}
631
632int device_init(void)
633{
634    suseconds_t t0, t1;
635    int fd;
636
637    fd = open_uevent_socket();
638    if(fd < 0)
639        return -1;
640
641    fcntl(fd, F_SETFD, FD_CLOEXEC);
642    fcntl(fd, F_SETFL, O_NONBLOCK);
643
644    t0 = get_usecs();
645    coldboot(fd, "/sys/class");
646    coldboot(fd, "/sys/block");
647    coldboot(fd, "/sys/devices");
648    t1 = get_usecs();
649
650    log_event_print("coldboot %ld uS\n", ((long) (t1 - t0)));
651
652    return fd;
653}
654