service_manager.c revision 1d8843897e1e108586a6a51e05392ff509b3dd7e 
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_DRMIO, "drm.drmIOService" },
38    { AID_DRM,   "drm.drmManager" },
39    { AID_NFC,   "nfc" },
40    { AID_RADIO, "radio.phone" },
41    { AID_RADIO, "radio.sms" },
42    { AID_RADIO, "radio.phonesubinfo" },
43    { AID_RADIO, "radio.simphonebook" },
44/* TODO: remove after phone services are updated: */
45    { AID_RADIO, "phone" },
46    { AID_RADIO, "sip" },
47    { AID_RADIO, "isms" },
48    { AID_RADIO, "iphonesubinfo" },
49    { AID_RADIO, "simphonebook" },
50};
51
52void *svcmgr_handle;
53
54const char *str8(uint16_t *x)
55{
56    static char buf[128];
57    unsigned max = 127;
58    char *p = buf;
59
60    if (x) {
61        while (*x && max--) {
62            *p++ = *x++;
63        }
64    }
65    *p++ = 0;
66    return buf;
67}
68
69int str16eq(uint16_t *a, const char *b)
70{
71    while (*a && *b)
72        if (*a++ != *b++) return 0;
73    if (*a || *b)
74        return 0;
75    return 1;
76}
77
78int svc_can_register(unsigned uid, uint16_t *name)
79{
80    unsigned n;
81
82    if ((uid == 0) || (uid == AID_SYSTEM))
83        return 1;
84
85    for (n = 0; n < sizeof(allowed) / sizeof(allowed[0]); n++)
86        if ((uid == allowed[n].uid) && str16eq(name, allowed[n].name))
87            return 1;
88
89    return 0;
90}
91
92struct svcinfo
93{
94    struct svcinfo *next;
95    void *ptr;
96    struct binder_death death;
97    unsigned len;
98    uint16_t name[0];
99};
100
101struct svcinfo *svclist = 0;
102
103struct svcinfo *find_svc(uint16_t *s16, unsigned len)
104{
105    struct svcinfo *si;
106
107    for (si = svclist; si; si = si->next) {
108        if ((len == si->len) &&
109            !memcmp(s16, si->name, len * sizeof(uint16_t))) {
110            return si;
111        }
112    }
113    return 0;
114}
115
116void svcinfo_death(struct binder_state *bs, void *ptr)
117{
118    struct svcinfo *si = ptr;
119    LOGI("service '%s' died\n", str8(si->name));
120    if (si->ptr) {
121        binder_release(bs, si->ptr);
122        si->ptr = 0;
123    }
124}
125
126uint16_t svcmgr_id[] = {
127    'a','n','d','r','o','i','d','.','o','s','.',
128    'I','S','e','r','v','i','c','e','M','a','n','a','g','e','r'
129};
130
131
132void *do_find_service(struct binder_state *bs, uint16_t *s, unsigned len)
133{
134    struct svcinfo *si;
135    si = find_svc(s, len);
136
137//    LOGI("check_service('%s') ptr = %p\n", str8(s), si ? si->ptr : 0);
138    if (si && si->ptr) {
139        return si->ptr;
140    } else {
141        return 0;
142    }
143}
144
145int do_add_service(struct binder_state *bs,
146                   uint16_t *s, unsigned len,
147                   void *ptr, unsigned uid)
148{
149    struct svcinfo *si;
150//    LOGI("add_service('%s',%p) uid=%d\n", str8(s), ptr, uid);
151
152    if (!ptr || (len == 0) || (len > 127))
153        return -1;
154
155    if (!svc_can_register(uid, s)) {
156        LOGE("add_service('%s',%p) uid=%d - PERMISSION DENIED\n",
157             str8(s), ptr, uid);
158        return -1;
159    }
160
161    si = find_svc(s, len);
162    if (si) {
163        if (si->ptr) {
164            LOGE("add_service('%s',%p) uid=%d - ALREADY REGISTERED, OVERRIDE\n",
165                 str8(s), ptr, uid);
166            svcinfo_death(bs, si);
167        }
168        si->ptr = ptr;
169    } else {
170        si = malloc(sizeof(*si) + (len + 1) * sizeof(uint16_t));
171        if (!si) {
172            LOGE("add_service('%s',%p) uid=%d - OUT OF MEMORY\n",
173                 str8(s), ptr, uid);
174            return -1;
175        }
176        si->ptr = ptr;
177        si->len = len;
178        memcpy(si->name, s, (len + 1) * sizeof(uint16_t));
179        si->name[len] = '\0';
180        si->death.func = svcinfo_death;
181        si->death.ptr = si;
182        si->next = svclist;
183        svclist = si;
184    }
185
186    binder_acquire(bs, ptr);
187    binder_link_to_death(bs, ptr, &si->death);
188    return 0;
189}
190
191int svcmgr_handler(struct binder_state *bs,
192                   struct binder_txn *txn,
193                   struct binder_io *msg,
194                   struct binder_io *reply)
195{
196    struct svcinfo *si;
197    uint16_t *s;
198    unsigned len;
199    void *ptr;
200    uint32_t strict_policy;
201
202//    LOGI("target=%p code=%d pid=%d uid=%d\n",
203//         txn->target, txn->code, txn->sender_pid, txn->sender_euid);
204
205    if (txn->target != svcmgr_handle)
206        return -1;
207
208    // Equivalent to Parcel::enforceInterface(), reading the RPC
209    // header with the strict mode policy mask and the interface name.
210    // Note that we ignore the strict_policy and don't propagate it
211    // further (since we do no outbound RPCs anyway).
212    strict_policy = bio_get_uint32(msg);
213    s = bio_get_string16(msg, &len);
214    if ((len != (sizeof(svcmgr_id) / 2)) ||
215        memcmp(svcmgr_id, s, sizeof(svcmgr_id))) {
216        fprintf(stderr,"invalid id %s\n", str8(s));
217        return -1;
218    }
219
220    switch(txn->code) {
221    case SVC_MGR_GET_SERVICE:
222    case SVC_MGR_CHECK_SERVICE:
223        s = bio_get_string16(msg, &len);
224        ptr = do_find_service(bs, s, len);
225        if (!ptr)
226            break;
227        bio_put_ref(reply, ptr);
228        return 0;
229
230    case SVC_MGR_ADD_SERVICE:
231        s = bio_get_string16(msg, &len);
232        ptr = bio_get_ref(msg);
233        if (do_add_service(bs, s, len, ptr, txn->sender_euid))
234            return -1;
235        break;
236
237    case SVC_MGR_LIST_SERVICES: {
238        unsigned n = bio_get_uint32(msg);
239
240        si = svclist;
241        while ((n-- > 0) && si)
242            si = si->next;
243        if (si) {
244            bio_put_string16(reply, si->name);
245            return 0;
246        }
247        return -1;
248    }
249    default:
250        LOGE("unknown code %d\n", txn->code);
251        return -1;
252    }
253
254    bio_put_uint32(reply, 0);
255    return 0;
256}
257
258int main(int argc, char **argv)
259{
260    struct binder_state *bs;
261    void *svcmgr = BINDER_SERVICE_MANAGER;
262
263    bs = binder_open(128*1024);
264
265    if (binder_become_context_manager(bs)) {
266        LOGE("cannot become context manager (%s)\n", strerror(errno));
267        return -1;
268    }
269
270    svcmgr_handle = svcmgr;
271    binder_loop(bs, svcmgr_handler);
272    return 0;
273}
274