devices.c revision 6ed11ebecd3eaffd84d79706a4a3a74d39f19715 
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        /* these should not be world writable */
102    { "/dev/diag",          0660,   AID_RADIO,      AID_RADIO,        0 },
103    { "/dev/diag_arm9",     0660,   AID_RADIO,      AID_RADIO,        0 },
104    { "/dev/android_adb",   0660,   AID_ADB,        AID_ADB,        0 },
105    { "/dev/android_adb_enable",   0660,   AID_ADB,        AID_ADB,        0 },
106    { "/dev/ttyMSM0",       0600,   AID_BLUETOOTH,  AID_BLUETOOTH,  0 },
107    { "/dev/ttyHS0",        0600,   AID_BLUETOOTH,  AID_BLUETOOTH,  0 },
108    { "/dev/uinput",        0660,   AID_SYSTEM,     AID_BLUETOOTH,  0 },
109    { "/dev/alarm",         0664,   AID_SYSTEM,     AID_RADIO,      0 },
110    { "/dev/tty0",          0660,   AID_ROOT,       AID_SYSTEM,     0 },
111    { "/dev/graphics/",     0660,   AID_ROOT,       AID_GRAPHICS,   1 },
112    { "/dev/msm_hw3dm",     0660,   AID_SYSTEM,     AID_GRAPHICS,   0 },
113    { "/dev/input/",        0660,   AID_ROOT,       AID_INPUT,      1 },
114    { "/dev/eac",           0660,   AID_ROOT,       AID_AUDIO,      0 },
115    { "/dev/cam",           0660,   AID_ROOT,       AID_CAMERA,     0 },
116    { "/dev/pmem",          0660,   AID_SYSTEM,     AID_GRAPHICS,   0 },
117    { "/dev/pmem_gpu",      0660,   AID_SYSTEM,     AID_GRAPHICS,   1 },
118    { "/dev/pmem_adsp",     0660,   AID_SYSTEM,     AID_AUDIO,      1 },
119    { "/dev/pmem_camera",   0660,   AID_SYSTEM,     AID_CAMERA,     1 },
120    { "/dev/oncrpc/",       0660,   AID_ROOT,       AID_SYSTEM,     1 },
121    { "/dev/adsp/",         0660,   AID_SYSTEM,     AID_AUDIO,      1 },
122    { "/dev/mt9t013",       0660,   AID_SYSTEM,     AID_SYSTEM,     0 },
123    { "/dev/msm_camera/",   0660,   AID_SYSTEM,     AID_SYSTEM,     1 },
124    { "/dev/akm8976_daemon",0640,   AID_COMPASS,    AID_SYSTEM,     0 },
125    { "/dev/akm8976_aot",   0640,   AID_COMPASS,    AID_SYSTEM,     0 },
126    { "/dev/akm8973_daemon",0640,   AID_COMPASS,    AID_SYSTEM,     0 },
127    { "/dev/akm8973_aot",   0640,   AID_COMPASS,    AID_SYSTEM,     0 },
128    { "/dev/bma150",        0640,   AID_COMPASS,    AID_SYSTEM,     0 },
129    { "/dev/cm3602",        0640,   AID_COMPASS,    AID_SYSTEM,     0 },
130    { "/dev/akm8976_pffd",  0640,   AID_COMPASS,    AID_SYSTEM,     0 },
131    { "/dev/msm_pcm_out",   0660,   AID_SYSTEM,     AID_AUDIO,      1 },
132    { "/dev/msm_pcm_in",    0660,   AID_SYSTEM,     AID_AUDIO,      1 },
133    { "/dev/msm_pcm_ctl",   0660,   AID_SYSTEM,     AID_AUDIO,      1 },
134    { "/dev/msm_snd",       0660,   AID_SYSTEM,     AID_AUDIO,      1 },
135    { "/dev/msm_mp3",       0660,   AID_SYSTEM,     AID_AUDIO,      1 },
136    { "/dev/msm_audpre",    0660,   AID_SYSTEM,     AID_AUDIO,      0 },
137    { "/dev/htc-acoustic",  0660,   AID_SYSTEM,     AID_AUDIO,      0 },
138    { "/dev/snd/dsp",       0660,   AID_SYSTEM,     AID_AUDIO,      0 },
139    { "/dev/snd/dsp1",      0660,   AID_SYSTEM,     AID_AUDIO,      0 },
140    { "/dev/snd/mixer",     0660,   AID_SYSTEM,     AID_AUDIO,      0 },
141    { "/dev/smd0",          0640,   AID_RADIO,      AID_RADIO,      0 },
142    { "/dev/qemu_trace",    0666,   AID_SYSTEM,     AID_SYSTEM,     0 },
143    { "/dev/qmi",           0640,   AID_RADIO,      AID_RADIO,      0 },
144    { "/dev/qmi0",          0640,   AID_RADIO,      AID_RADIO,      0 },
145    { "/dev/qmi1",          0640,   AID_RADIO,      AID_RADIO,      0 },
146    { "/dev/qmi2",          0640,   AID_RADIO,      AID_RADIO,      0 },
147        /* CDMA radio interface MUX */
148    { "/dev/ts0710mux",     0640,   AID_RADIO,      AID_RADIO,      1 },
149    { "/dev/ppp",           0660,   AID_RADIO,      AID_VPN,        0 },
150    { "/dev/tun",           0640,   AID_VPN,        AID_VPN,        0 },
151    { NULL, 0, 0, 0, 0 },
152};
153
154/* devperms_partners list and perm_node are for hardware specific /dev entries */
155struct perm_node {
156    struct perms_ dp;
157    struct listnode plist;
158};
159list_declare(devperms_partners);
160
161/*
162 * Permission override when in emulator mode, must be parsed before
163 * system properties is initalized.
164 */
165static int qemu_perm_count;
166static struct perms_ qemu_perms[MAX_QEMU_PERM + 1];
167
168int add_devperms_partners(const char *name, mode_t perm, unsigned int uid,
169                        unsigned int gid, unsigned short prefix) {
170    int size;
171    struct perm_node *node = malloc(sizeof (struct perm_node));
172    if (!node)
173        return -ENOMEM;
174
175    size = strlen(name) + 1;
176    if ((node->dp.name = malloc(size)) == NULL)
177        return -ENOMEM;
178
179    memcpy(node->dp.name, name, size);
180    node->dp.perm = perm;
181    node->dp.uid = uid;
182    node->dp.gid = gid;
183    node->dp.prefix = prefix;
184
185    list_add_tail(&devperms_partners, &node->plist);
186    return 0;
187}
188
189void qemu_init(void) {
190    qemu_perm_count = 0;
191    memset(&qemu_perms, 0, sizeof(qemu_perms));
192}
193
194static int qemu_perm(const char* name, mode_t perm, unsigned int uid,
195                         unsigned int gid, unsigned short prefix)
196{
197    char *buf;
198    if (qemu_perm_count == MAX_QEMU_PERM)
199        return -ENOSPC;
200
201    buf = malloc(strlen(name) + 1);
202    if (!buf)
203        return -errno;
204
205    strlcpy(buf, name, strlen(name) + 1);
206    qemu_perms[qemu_perm_count].name = buf;
207    qemu_perms[qemu_perm_count].perm = perm;
208    qemu_perms[qemu_perm_count].uid = uid;
209    qemu_perms[qemu_perm_count].gid = gid;
210    qemu_perms[qemu_perm_count].prefix = prefix;
211
212    qemu_perm_count++;
213    return 0;
214}
215
216/* Permission overrides for emulator that are parsed from /proc/cmdline. */
217void qemu_cmdline(const char* name, const char *value)
218{
219    char *buf;
220    if (!strcmp(name, "android.ril")) {
221        /* cmd line params currently assume /dev/ prefix */
222        if (asprintf(&buf, CMDLINE_PREFIX"/%s", value) == -1) {
223            return;
224        }
225        INFO("nani- buf:: %s\n", buf);
226        qemu_perm(buf, 0660, AID_RADIO, AID_ROOT, 0);
227    }
228}
229
230static int get_device_perm_inner(struct perms_ *perms, const char *path,
231                                    unsigned *uid, unsigned *gid, mode_t *perm)
232{
233    int i;
234    for(i = 0; perms[i].name; i++) {
235
236        if(perms[i].prefix) {
237            if(strncmp(path, perms[i].name, strlen(perms[i].name)))
238                continue;
239        } else {
240            if(strcmp(path, perms[i].name))
241                continue;
242        }
243        *uid = perms[i].uid;
244        *gid = perms[i].gid;
245        *perm = perms[i].perm;
246        return 0;
247    }
248    return -1;
249}
250
251/* First checks for emulator specific permissions specified in /proc/cmdline. */
252static mode_t get_device_perm(const char *path, unsigned *uid, unsigned *gid)
253{
254    mode_t perm;
255
256    if (get_device_perm_inner(qemu_perms, path, uid, gid, &perm) == 0) {
257        return perm;
258    } else if (get_device_perm_inner(devperms, path, uid, gid, &perm) == 0) {
259        return perm;
260    } else {
261        struct listnode *node;
262        struct perm_node *perm_node;
263        struct perms_ *dp;
264
265        /* Check partners list. */
266        list_for_each(node, &devperms_partners) {
267            perm_node = node_to_item(node, struct perm_node, plist);
268            dp = &perm_node->dp;
269
270            if (dp->prefix) {
271                if (strncmp(path, dp->name, strlen(dp->name)))
272                    continue;
273            } else {
274                if (strcmp(path, dp->name))
275                    continue;
276            }
277            /* Found perm in partner list. */
278            *uid = dp->uid;
279            *gid = dp->gid;
280            return dp->perm;
281        }
282        /* Default if nothing found. */
283        *uid = 0;
284        *gid = 0;
285        return 0600;
286    }
287}
288
289static void make_device(const char *path, int block, int major, int minor)
290{
291    unsigned uid;
292    unsigned gid;
293    mode_t mode;
294    dev_t dev;
295
296    if(major > 255 || minor > 255)
297        return;
298
299    mode = get_device_perm(path, &uid, &gid) | (block ? S_IFBLK : S_IFCHR);
300    dev = (major << 8) | minor;
301    mknod(path, mode, dev);
302    chown(path, uid, gid);
303}
304
305#ifdef LOG_UEVENTS
306
307static inline suseconds_t get_usecs(void)
308{
309    struct timeval tv;
310    gettimeofday(&tv, 0);
311    return tv.tv_sec * (suseconds_t) 1000000 + tv.tv_usec;
312}
313
314#define log_event_print(x...) INFO(x)
315
316#else
317
318#define log_event_print(fmt, args...)   do { } while (0)
319#define get_usecs()                     0
320
321#endif
322
323static void parse_event(const char *msg, struct uevent *uevent)
324{
325    uevent->action = "";
326    uevent->path = "";
327    uevent->subsystem = "";
328    uevent->firmware = "";
329    uevent->major = -1;
330    uevent->minor = -1;
331
332        /* currently ignoring SEQNUM */
333    while(*msg) {
334        if(!strncmp(msg, "ACTION=", 7)) {
335            msg += 7;
336            uevent->action = msg;
337        } else if(!strncmp(msg, "DEVPATH=", 8)) {
338            msg += 8;
339            uevent->path = msg;
340        } else if(!strncmp(msg, "SUBSYSTEM=", 10)) {
341            msg += 10;
342            uevent->subsystem = msg;
343        } else if(!strncmp(msg, "FIRMWARE=", 9)) {
344            msg += 9;
345            uevent->firmware = msg;
346        } else if(!strncmp(msg, "MAJOR=", 6)) {
347            msg += 6;
348            uevent->major = atoi(msg);
349        } else if(!strncmp(msg, "MINOR=", 6)) {
350            msg += 6;
351            uevent->minor = atoi(msg);
352        }
353
354            /* advance to after the next \0 */
355        while(*msg++)
356            ;
357    }
358
359    log_event_print("event { '%s', '%s', '%s', '%s', %d, %d }\n",
360                    uevent->action, uevent->path, uevent->subsystem,
361                    uevent->firmware, uevent->major, uevent->minor);
362}
363
364static void handle_device_event(struct uevent *uevent)
365{
366    char devpath[96];
367    char *base, *name;
368    int block;
369
370        /* if it's not a /dev device, nothing to do */
371    if((uevent->major < 0) || (uevent->minor < 0))
372        return;
373
374        /* do we have a name? */
375    name = strrchr(uevent->path, '/');
376    if(!name)
377        return;
378    name++;
379
380        /* too-long names would overrun our buffer */
381    if(strlen(name) > 64)
382        return;
383
384        /* are we block or char? where should we live? */
385    if(!strncmp(uevent->subsystem, "block", 5)) {
386        block = 1;
387        base = "/dev/block/";
388        mkdir(base, 0755);
389    } else {
390        block = 0;
391            /* this should probably be configurable somehow */
392        if(!strncmp(uevent->subsystem, "graphics", 8)) {
393            base = "/dev/graphics/";
394            mkdir(base, 0755);
395        } else if (!strncmp(uevent->subsystem, "oncrpc", 6)) {
396            base = "/dev/oncrpc/";
397            mkdir(base, 0755);
398        } else if (!strncmp(uevent->subsystem, "adsp", 4)) {
399            base = "/dev/adsp/";
400            mkdir(base, 0755);
401        } else if (!strncmp(uevent->subsystem, "msm_camera", 10)) {
402            base = "/dev/msm_camera/";
403            mkdir(base, 0755);
404        } else if(!strncmp(uevent->subsystem, "input", 5)) {
405            base = "/dev/input/";
406            mkdir(base, 0755);
407        } else if(!strncmp(uevent->subsystem, "mtd", 3)) {
408            base = "/dev/mtd/";
409            mkdir(base, 0755);
410        } else if(!strncmp(uevent->subsystem, "sound", 5)) {
411            base = "/dev/snd/";
412            mkdir(base, 0755);
413        } else if(!strncmp(uevent->subsystem, "misc", 4) &&
414                    !strncmp(name, "log_", 4)) {
415            base = "/dev/log/";
416            mkdir(base, 0755);
417            name += 4;
418        } else
419            base = "/dev/";
420    }
421
422    snprintf(devpath, sizeof(devpath), "%s%s", base, name);
423
424    if(!strcmp(uevent->action, "add")) {
425        make_device(devpath, block, uevent->major, uevent->minor);
426        return;
427    }
428
429    if(!strcmp(uevent->action, "remove")) {
430        unlink(devpath);
431        return;
432    }
433}
434
435static int load_firmware(int fw_fd, int loading_fd, int data_fd)
436{
437    struct stat st;
438    long len_to_copy;
439    int ret = 0;
440
441    if(fstat(fw_fd, &st) < 0)
442        return -1;
443    len_to_copy = st.st_size;
444
445    write(loading_fd, "1", 1);  /* start transfer */
446
447    while (len_to_copy > 0) {
448        char buf[PAGE_SIZE];
449        ssize_t nr;
450
451        nr = read(fw_fd, buf, sizeof(buf));
452        if(!nr)
453            break;
454        if(nr < 0) {
455            ret = -1;
456            break;
457        }
458
459        len_to_copy -= nr;
460        while (nr > 0) {
461            ssize_t nw = 0;
462
463            nw = write(data_fd, buf + nw, nr);
464            if(nw <= 0) {
465                ret = -1;
466                goto out;
467            }
468            nr -= nw;
469        }
470    }
471
472out:
473    if(!ret)
474        write(loading_fd, "0", 1);  /* successful end of transfer */
475    else
476        write(loading_fd, "-1", 2); /* abort transfer */
477
478    return ret;
479}
480
481static void process_firmware_event(struct uevent *uevent)
482{
483    char *root, *loading, *data, *file;
484    int l, loading_fd, data_fd, fw_fd;
485
486    log_event_print("firmware event { '%s', '%s' }\n",
487                    uevent->path, uevent->firmware);
488
489    l = asprintf(&root, SYSFS_PREFIX"%s/", uevent->path);
490    if (l == -1)
491        return;
492
493    l = asprintf(&loading, "%sloading", root);
494    if (l == -1)
495        goto root_free_out;
496
497    l = asprintf(&data, "%sdata", root);
498    if (l == -1)
499        goto loading_free_out;
500
501    l = asprintf(&file, FIRMWARE_DIR"/%s", uevent->firmware);
502    if (l == -1)
503        goto data_free_out;
504
505    loading_fd = open(loading, O_WRONLY);
506    if(loading_fd < 0)
507        goto file_free_out;
508
509    data_fd = open(data, O_WRONLY);
510    if(data_fd < 0)
511        goto loading_close_out;
512
513    fw_fd = open(file, O_RDONLY);
514    if(fw_fd < 0)
515        goto data_close_out;
516
517    if(!load_firmware(fw_fd, loading_fd, data_fd))
518        log_event_print("firmware copy success { '%s', '%s' }\n", root, file);
519    else
520        log_event_print("firmware copy failure { '%s', '%s' }\n", root, file);
521
522    close(fw_fd);
523data_close_out:
524    close(data_fd);
525loading_close_out:
526    close(loading_fd);
527file_free_out:
528    free(file);
529data_free_out:
530    free(data);
531loading_free_out:
532    free(loading);
533root_free_out:
534    free(root);
535}
536
537static void handle_firmware_event(struct uevent *uevent)
538{
539    pid_t pid;
540
541    if(strcmp(uevent->subsystem, "firmware"))
542        return;
543
544    if(strcmp(uevent->action, "add"))
545        return;
546
547    /* we fork, to avoid making large memory allocations in init proper */
548    pid = fork();
549    if (!pid) {
550        process_firmware_event(uevent);
551        exit(EXIT_SUCCESS);
552    }
553}
554
555#define UEVENT_MSG_LEN  1024
556void handle_device_fd(int fd)
557{
558    char msg[UEVENT_MSG_LEN+2];
559    int n;
560
561    while((n = recv(fd, msg, UEVENT_MSG_LEN, 0)) > 0) {
562        struct uevent uevent;
563
564        if(n == UEVENT_MSG_LEN)   /* overflow -- discard */
565            continue;
566
567        msg[n] = '\0';
568        msg[n+1] = '\0';
569
570        parse_event(msg, &uevent);
571
572        handle_device_event(&uevent);
573        handle_firmware_event(&uevent);
574    }
575}
576
577/* Coldboot walks parts of the /sys tree and pokes the uevent files
578** to cause the kernel to regenerate device add events that happened
579** before init's device manager was started
580**
581** We drain any pending events from the netlink socket every time
582** we poke another uevent file to make sure we don't overrun the
583** socket's buffer.
584*/
585
586static void do_coldboot(int event_fd, DIR *d)
587{
588    struct dirent *de;
589    int dfd, fd;
590
591    dfd = dirfd(d);
592
593    fd = openat(dfd, "uevent", O_WRONLY);
594    if(fd >= 0) {
595        write(fd, "add\n", 4);
596        close(fd);
597        handle_device_fd(event_fd);
598    }
599
600    while((de = readdir(d))) {
601        DIR *d2;
602
603        if(de->d_type != DT_DIR || de->d_name[0] == '.')
604            continue;
605
606        fd = openat(dfd, de->d_name, O_RDONLY | O_DIRECTORY);
607        if(fd < 0)
608            continue;
609
610        d2 = fdopendir(fd);
611        if(d2 == 0)
612            close(fd);
613        else {
614            do_coldboot(event_fd, d2);
615            closedir(d2);
616        }
617    }
618}
619
620static void coldboot(int event_fd, const char *path)
621{
622    DIR *d = opendir(path);
623    if(d) {
624        do_coldboot(event_fd, d);
625        closedir(d);
626    }
627}
628
629int device_init(void)
630{
631    suseconds_t t0, t1;
632    int fd;
633
634    fd = open_uevent_socket();
635    if(fd < 0)
636        return -1;
637
638    fcntl(fd, F_SETFD, FD_CLOEXEC);
639    fcntl(fd, F_SETFL, O_NONBLOCK);
640
641    t0 = get_usecs();
642    coldboot(fd, "/sys/class");
643    coldboot(fd, "/sys/block");
644    coldboot(fd, "/sys/devices");
645    t1 = get_usecs();
646
647    log_event_print("coldboot %ld uS\n", ((long) (t1 - t0)));
648
649    return fd;
650}
651