service_manager.c revision 9387f4f80081128601da936fe5e6006809ff479c 
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 LOGI(x...) fprintf(stderr, "svcmgr: " x)
15#define LOGE(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 */
26static struct {
27    unsigned uid;
28    const char *name;
29} allowed[] = {
30#ifdef LVMX
31    { AID_MEDIA, "com.lifevibes.mx.ipc" },
32#endif
33    { AID_MEDIA, "media.audio_flinger" },
34    { AID_MEDIA, "media.player" },
35    { AID_MEDIA, "media.camera" },
36    { AID_MEDIA, "media.audio_policy" },
37    { AID_DRM,   "drm.drmManager" },
38    { AID_NFC,   "nfc" },
39    { AID_RADIO, "radio.phone" },
40    { AID_RADIO, "radio.sms" },
41    { AID_RADIO, "radio.phonesubinfo" },
42    { AID_RADIO, "radio.simphonebook" },
43/* TODO: remove after phone services are updated: */
44    { AID_RADIO, "phone" },
45    { AID_RADIO, "sip" },
46    { AID_RADIO, "isms" },
47    { AID_RADIO, "iphonesubinfo" },
48    { AID_RADIO, "simphonebook" },
49    { AID_MEDIA, "common_time.clock" },
50    { AID_MEDIA, "common_time.config" },
51};
52
53void *svcmgr_handle;
54
55const 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
70int 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
79int 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
93struct svcinfo
94{
95    struct svcinfo *next;
96    void *ptr;
97    struct binder_death death;
98    unsigned len;
99    uint16_t name[0];
100};
101
102struct svcinfo *svclist = 0;
103
104struct svcinfo *find_svc(uint16_t *s16, unsigned len)
105{
106    struct svcinfo *si;
107
108    for (si = svclist; si; si = si->next) {
109        if ((len == si->len) &&
110            !memcmp(s16, si->name, len * sizeof(uint16_t))) {
111            return si;
112        }
113    }
114    return 0;
115}
116
117void svcinfo_death(struct binder_state *bs, void *ptr)
118{
119    struct svcinfo *si = ptr;
120    LOGI("service '%s' died\n", str8(si->name));
121    if (si->ptr) {
122        binder_release(bs, si->ptr);
123        si->ptr = 0;
124    }
125}
126
127uint16_t svcmgr_id[] = {
128    'a','n','d','r','o','i','d','.','o','s','.',
129    'I','S','e','r','v','i','c','e','M','a','n','a','g','e','r'
130};
131
132
133void *do_find_service(struct binder_state *bs, uint16_t *s, unsigned len)
134{
135    struct svcinfo *si;
136    si = find_svc(s, len);
137
138//    LOGI("check_service('%s') ptr = %p\n", str8(s), si ? si->ptr : 0);
139    if (si && si->ptr) {
140        return si->ptr;
141    } else {
142        return 0;
143    }
144}
145
146int do_add_service(struct binder_state *bs,
147                   uint16_t *s, unsigned len,
148                   void *ptr, unsigned uid)
149{
150    struct svcinfo *si;
151//    LOGI("add_service('%s',%p) uid=%d\n", str8(s), ptr, uid);
152
153    if (!ptr || (len == 0) || (len > 127))
154        return -1;
155
156    if (!svc_can_register(uid, s)) {
157        LOGE("add_service('%s',%p) uid=%d - PERMISSION DENIED\n",
158             str8(s), ptr, uid);
159        return -1;
160    }
161
162    si = find_svc(s, len);
163    if (si) {
164        if (si->ptr) {
165            LOGE("add_service('%s',%p) uid=%d - ALREADY REGISTERED, OVERRIDE\n",
166                 str8(s), ptr, uid);
167            svcinfo_death(bs, si);
168        }
169        si->ptr = ptr;
170    } else {
171        si = malloc(sizeof(*si) + (len + 1) * sizeof(uint16_t));
172        if (!si) {
173            LOGE("add_service('%s',%p) uid=%d - OUT OF MEMORY\n",
174                 str8(s), ptr, uid);
175            return -1;
176        }
177        si->ptr = ptr;
178        si->len = len;
179        memcpy(si->name, s, (len + 1) * sizeof(uint16_t));
180        si->name[len] = '\0';
181        si->death.func = svcinfo_death;
182        si->death.ptr = si;
183        si->next = svclist;
184        svclist = si;
185    }
186
187    binder_acquire(bs, ptr);
188    binder_link_to_death(bs, ptr, &si->death);
189    return 0;
190}
191
192int svcmgr_handler(struct binder_state *bs,
193                   struct binder_txn *txn,
194                   struct binder_io *msg,
195                   struct binder_io *reply)
196{
197    struct svcinfo *si;
198    uint16_t *s;
199    unsigned len;
200    void *ptr;
201    uint32_t strict_policy;
202
203//    LOGI("target=%p code=%d pid=%d uid=%d\n",
204//         txn->target, txn->code, txn->sender_pid, txn->sender_euid);
205
206    if (txn->target != svcmgr_handle)
207        return -1;
208
209    // Equivalent to Parcel::enforceInterface(), reading the RPC
210    // header with the strict mode policy mask and the interface name.
211    // Note that we ignore the strict_policy and don't propagate it
212    // further (since we do no outbound RPCs anyway).
213    strict_policy = bio_get_uint32(msg);
214    s = bio_get_string16(msg, &len);
215    if ((len != (sizeof(svcmgr_id) / 2)) ||
216        memcmp(svcmgr_id, s, sizeof(svcmgr_id))) {
217        fprintf(stderr,"invalid id %s\n", str8(s));
218        return -1;
219    }
220
221    switch(txn->code) {
222    case SVC_MGR_GET_SERVICE:
223    case SVC_MGR_CHECK_SERVICE:
224        s = bio_get_string16(msg, &len);
225        ptr = do_find_service(bs, s, len);
226        if (!ptr)
227            break;
228        bio_put_ref(reply, ptr);
229        return 0;
230
231    case SVC_MGR_ADD_SERVICE:
232        s = bio_get_string16(msg, &len);
233        ptr = bio_get_ref(msg);
234        if (do_add_service(bs, s, len, ptr, txn->sender_euid))
235            return -1;
236        break;
237
238    case SVC_MGR_LIST_SERVICES: {
239        unsigned n = bio_get_uint32(msg);
240
241        si = svclist;
242        while ((n-- > 0) && si)
243            si = si->next;
244        if (si) {
245            bio_put_string16(reply, si->name);
246            return 0;
247        }
248        return -1;
249    }
250    default:
251        LOGE("unknown code %d\n", txn->code);
252        return -1;
253    }
254
255    bio_put_uint32(reply, 0);
256    return 0;
257}
258
259int main(int argc, char **argv)
260{
261    struct binder_state *bs;
262    void *svcmgr = BINDER_SERVICE_MANAGER;
263
264    bs = binder_open(128*1024);
265
266    if (binder_become_context_manager(bs)) {
267        LOGE("cannot become context manager (%s)\n", strerror(errno));
268        return -1;
269    }
270
271    svcmgr_handle = svcmgr;
272    binder_loop(bs, svcmgr_handler);
273    return 0;
274}
275