Home | History | Annotate | Download | only in servicemanager 
      1 /* Copyright 2008 The Android Open Source Project
      2  */
      3 
      4 #include <stdio.h>
      5 #include <stdlib.h>
      6 #include <errno.h>
      7 #include <fcntl.h>
      8 
      9 #include <private/android_filesystem_config.h>
     10 
     11 #include "binder.h"
     12 
     13 #if 0
     14 #define ALOGI(x...) fprintf(stderr, "svcmgr: " x)
     15 #define ALOGE(x...) fprintf(stderr, "svcmgr: " x)
     16 #else
     17 #define LOG_TAG "ServiceManager"
     18 #include <cutils/log.h>
     19 #endif
     20 
     21 /* TODO:
     22  * These should come from a config file or perhaps be
     23  * based on some namespace rules of some sort (media
     24  * uid can register media.*, etc)
     25  */
     26 static struct {
     27     unsigned uid;
     28     const char *name;
     29 } allowed[] = {
     30     { AID_MEDIA, "media.audio_flinger" },
     31     { AID_MEDIA, "media.log" },
     32     { AID_MEDIA, "media.player" },
     33     { AID_MEDIA, "media.camera" },
     34     { AID_MEDIA, "media.audio_policy" },
     35     { AID_DRM,   "drm.drmManager" },
     36     { AID_NFC,   "nfc" },
     37     { AID_BLUETOOTH, "bluetooth" },
     38     { AID_RADIO, "radio.phone" },
     39     { AID_RADIO, "radio.sms" },
     40     { AID_RADIO, "radio.phonesubinfo" },
     41     { AID_RADIO, "radio.simphonebook" },
     42 /* TODO: remove after phone services are updated: */
     43     { AID_RADIO, "phone" },
     44     { AID_RADIO, "sip" },
     45     { AID_RADIO, "isms" },
     46     { AID_RADIO, "iphonesubinfo" },
     47     { AID_RADIO, "simphonebook" },
     48     { AID_MEDIA, "common_time.clock" },
     49     { AID_MEDIA, "common_time.config" },
     50     { AID_KEYSTORE, "android.security.keystore" },
     51 };
     52 
     53 void *svcmgr_handle;
     54 
     55 const char *str8(uint16_t *x)
     56 {
     57     static char buf[128];
     58     unsigned max = 127;
     59     char *p = buf;
     60 
     61     if (x) {
     62         while (*x && max--) {
     63             *p++ = *x++;
     64         }
     65     }
     66     *p++ = 0;
     67     return buf;
     68 }
     69 
     70 int str16eq(uint16_t *a, const char *b)
     71 {
     72     while (*a && *b)
     73         if (*a++ != *b++) return 0;
     74     if (*a || *b)
     75         return 0;
     76     return 1;
     77 }
     78 
     79 int svc_can_register(unsigned uid, uint16_t *name)
     80 {
     81     unsigned n;
     82 
     83     if ((uid == 0) || (uid == AID_SYSTEM))
     84         return 1;
     85 
     86     for (n = 0; n < sizeof(allowed) / sizeof(allowed[0]); n++)
     87         if ((uid == allowed[n].uid) && str16eq(name, allowed[n].name))
     88             return 1;
     89 
     90     return 0;
     91 }
     92 
     93 struct svcinfo
     94 {
     95     struct svcinfo *next;
     96     void *ptr;
     97     struct binder_death death;
     98     int allow_isolated;
     99     unsigned len;
    100     uint16_t name[0];
    101 };
    102 
    103 struct svcinfo *svclist = 0;
    104 
    105 struct svcinfo *find_svc(uint16_t *s16, unsigned len)
    106 {
    107     struct svcinfo *si;
    108 
    109     for (si = svclist; si; si = si->next) {
    110         if ((len == si->len) &&
    111             !memcmp(s16, si->name, len * sizeof(uint16_t))) {
    112             return si;
    113         }
    114     }
    115     return 0;
    116 }
    117 
    118 void svcinfo_death(struct binder_state *bs, void *ptr)
    119 {
    120     struct svcinfo *si = ptr;
    121     ALOGI("service '%s' died\n", str8(si->name));
    122     if (si->ptr) {
    123         binder_release(bs, si->ptr);
    124         si->ptr = 0;
    125     }
    126 }
    127 
    128 uint16_t svcmgr_id[] = {
    129     'a','n','d','r','o','i','d','.','o','s','.',
    130     'I','S','e','r','v','i','c','e','M','a','n','a','g','e','r'
    131 };
    132 
    133 
    134 void *do_find_service(struct binder_state *bs, uint16_t *s, unsigned len, unsigned uid)
    135 {
    136     struct svcinfo *si;
    137     si = find_svc(s, len);
    138 
    139 //    ALOGI("check_service('%s') ptr = %p\n", str8(s), si ? si->ptr : 0);
    140     if (si && si->ptr) {
    141         if (!si->allow_isolated) {
    142             // If this service doesn't allow access from isolated processes,
    143             // then check the uid to see if it is isolated.
    144             unsigned appid = uid % AID_USER;
    145             if (appid >= AID_ISOLATED_START && appid <= AID_ISOLATED_END) {
    146                 return 0;
    147             }
    148         }
    149         return si->ptr;
    150     } else {
    151         return 0;
    152     }
    153 }
    154 
    155 int do_add_service(struct binder_state *bs,
    156                    uint16_t *s, unsigned len,
    157                    void *ptr, unsigned uid, int allow_isolated)
    158 {
    159     struct svcinfo *si;
    160     //ALOGI("add_service('%s',%p,%s) uid=%d\n", str8(s), ptr,
    161     //        allow_isolated ? "allow_isolated" : "!allow_isolated", uid);
    162 
    163     if (!ptr || (len == 0) || (len > 127))
    164         return -1;
    165 
    166     if (!svc_can_register(uid, s)) {
    167         ALOGE("add_service('%s',%p) uid=%d - PERMISSION DENIED\n",
    168              str8(s), ptr, uid);
    169         return -1;
    170     }
    171 
    172     si = find_svc(s, len);
    173     if (si) {
    174         if (si->ptr) {
    175             ALOGE("add_service('%s',%p) uid=%d - ALREADY REGISTERED, OVERRIDE\n",
    176                  str8(s), ptr, uid);
    177             svcinfo_death(bs, si);
    178         }
    179         si->ptr = ptr;
    180     } else {
    181         si = malloc(sizeof(*si) + (len + 1) * sizeof(uint16_t));
    182         if (!si) {
    183             ALOGE("add_service('%s',%p) uid=%d - OUT OF MEMORY\n",
    184                  str8(s), ptr, uid);
    185             return -1;
    186         }
    187         si->ptr = ptr;
    188         si->len = len;
    189         memcpy(si->name, s, (len + 1) * sizeof(uint16_t));
    190         si->name[len] = '\0';
    191         si->death.func = svcinfo_death;
    192         si->death.ptr = si;
    193         si->allow_isolated = allow_isolated;
    194         si->next = svclist;
    195         svclist = si;
    196     }
    197 
    198     binder_acquire(bs, ptr);
    199     binder_link_to_death(bs, ptr, &si->death);
    200     return 0;
    201 }
    202 
    203 int svcmgr_handler(struct binder_state *bs,
    204                    struct binder_txn *txn,
    205                    struct binder_io *msg,
    206                    struct binder_io *reply)
    207 {
    208     struct svcinfo *si;
    209     uint16_t *s;
    210     unsigned len;
    211     void *ptr;
    212     uint32_t strict_policy;
    213     int allow_isolated;
    214 
    215 //    ALOGI("target=%p code=%d pid=%d uid=%d\n",
    216 //         txn->target, txn->code, txn->sender_pid, txn->sender_euid);
    217 
    218     if (txn->target != svcmgr_handle)
    219         return -1;
    220 
    221     // Equivalent to Parcel::enforceInterface(), reading the RPC
    222     // header with the strict mode policy mask and the interface name.
    223     // Note that we ignore the strict_policy and don't propagate it
    224     // further (since we do no outbound RPCs anyway).
    225     strict_policy = bio_get_uint32(msg);
    226     s = bio_get_string16(msg, &len);
    227     if ((len != (sizeof(svcmgr_id) / 2)) ||
    228         memcmp(svcmgr_id, s, sizeof(svcmgr_id))) {
    229         fprintf(stderr,"invalid id %s\n", str8(s));
    230         return -1;
    231     }
    232 
    233     switch(txn->code) {
    234     case SVC_MGR_GET_SERVICE:
    235     case SVC_MGR_CHECK_SERVICE:
    236         s = bio_get_string16(msg, &len);
    237         ptr = do_find_service(bs, s, len, txn->sender_euid);
    238         if (!ptr)
    239             break;
    240         bio_put_ref(reply, ptr);
    241         return 0;
    242 
    243     case SVC_MGR_ADD_SERVICE:
    244         s = bio_get_string16(msg, &len);
    245         ptr = bio_get_ref(msg);
    246         allow_isolated = bio_get_uint32(msg) ? 1 : 0;
    247         if (do_add_service(bs, s, len, ptr, txn->sender_euid, allow_isolated))
    248             return -1;
    249         break;
    250 
    251     case SVC_MGR_LIST_SERVICES: {
    252         unsigned n = bio_get_uint32(msg);
    253 
    254         si = svclist;
    255         while ((n-- > 0) && si)
    256             si = si->next;
    257         if (si) {
    258             bio_put_string16(reply, si->name);
    259             return 0;
    260         }
    261         return -1;
    262     }
    263     default:
    264         ALOGE("unknown code %d\n", txn->code);
    265         return -1;
    266     }
    267 
    268     bio_put_uint32(reply, 0);
    269     return 0;
    270 }
    271 
    272 int main(int argc, char **argv)
    273 {
    274     struct binder_state *bs;
    275     void *svcmgr = BINDER_SERVICE_MANAGER;
    276 
    277     bs = binder_open(128*1024);
    278 
    279     if (binder_become_context_manager(bs)) {
    280         ALOGE("cannot become context manager (%s)\n", strerror(errno));
    281         return -1;
    282     }
    283 
    284     svcmgr_handle = svcmgr;
    285     binder_loop(bs, svcmgr_handler);
    286     return 0;
    287 }
    288