service_manager.c revision 7e54ef71db3320a751571bba5259fba816399421 
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_RADIO, "radio.phone" },
38    { AID_RADIO, "radio.sms" },
39    { AID_RADIO, "radio.phonesubinfo" },
40    { AID_RADIO, "radio.simphonebook" },
41/* TODO: remove after phone services are updated: */
42    { AID_RADIO, "phone" },
43    { AID_RADIO, "sip" },
44    { AID_RADIO, "isms" },
45    { AID_RADIO, "iphonesubinfo" },
46    { AID_RADIO, "simphonebook" },
47};
48
49void *svcmgr_handle;
50
51const char *str8(uint16_t *x)
52{
53    static char buf[128];
54    unsigned max = 127;
55    char *p = buf;
56
57    if (x) {
58        while (*x && max--) {
59            *p++ = *x++;
60        }
61    }
62    *p++ = 0;
63    return buf;
64}
65
66int str16eq(uint16_t *a, const char *b)
67{
68    while (*a && *b)
69        if (*a++ != *b++) return 0;
70    if (*a || *b)
71        return 0;
72    return 1;
73}
74
75int svc_can_register(unsigned uid, uint16_t *name)
76{
77    unsigned n;
78
79    if ((uid == 0) || (uid == AID_SYSTEM))
80        return 1;
81
82    for (n = 0; n < sizeof(allowed) / sizeof(allowed[0]); n++)
83        if ((uid == allowed[n].uid) && str16eq(name, allowed[n].name))
84            return 1;
85
86    return 0;
87}
88
89struct svcinfo
90{
91    struct svcinfo *next;
92    void *ptr;
93    struct binder_death death;
94    unsigned len;
95    uint16_t name[0];
96};
97
98struct svcinfo *svclist = 0;
99
100struct svcinfo *find_svc(uint16_t *s16, unsigned len)
101{
102    struct svcinfo *si;
103
104    for (si = svclist; si; si = si->next) {
105        if ((len == si->len) &&
106            !memcmp(s16, si->name, len * sizeof(uint16_t))) {
107            return si;
108        }
109    }
110    return 0;
111}
112
113void svcinfo_death(struct binder_state *bs, void *ptr)
114{
115    struct svcinfo *si = ptr;
116    LOGI("service '%s' died\n", str8(si->name));
117    if (si->ptr) {
118        binder_release(bs, si->ptr);
119        si->ptr = 0;
120    }
121}
122
123uint16_t svcmgr_id[] = {
124    'a','n','d','r','o','i','d','.','o','s','.',
125    'I','S','e','r','v','i','c','e','M','a','n','a','g','e','r'
126};
127
128
129void *do_find_service(struct binder_state *bs, uint16_t *s, unsigned len)
130{
131    struct svcinfo *si;
132    si = find_svc(s, len);
133
134//    LOGI("check_service('%s') ptr = %p\n", str8(s), si ? si->ptr : 0);
135    if (si && si->ptr) {
136        return si->ptr;
137    } else {
138        return 0;
139    }
140}
141
142int do_add_service(struct binder_state *bs,
143                   uint16_t *s, unsigned len,
144                   void *ptr, unsigned uid)
145{
146    struct svcinfo *si;
147//    LOGI("add_service('%s',%p) uid=%d\n", str8(s), ptr, uid);
148
149    if (!ptr || (len == 0) || (len > 127))
150        return -1;
151
152    if (!svc_can_register(uid, s)) {
153        LOGE("add_service('%s',%p) uid=%d - PERMISSION DENIED\n",
154             str8(s), ptr, uid);
155        return -1;
156    }
157
158    si = find_svc(s, len);
159    if (si) {
160        if (si->ptr) {
161            LOGE("add_service('%s',%p) uid=%d - ALREADY REGISTERED\n",
162                 str8(s), ptr, uid);
163            return -1;
164        }
165        si->ptr = ptr;
166    } else {
167        si = malloc(sizeof(*si) + (len + 1) * sizeof(uint16_t));
168        if (!si) {
169            LOGE("add_service('%s',%p) uid=%d - OUT OF MEMORY\n",
170                 str8(s), ptr, uid);
171            return -1;
172        }
173        si->ptr = ptr;
174        si->len = len;
175        memcpy(si->name, s, (len + 1) * sizeof(uint16_t));
176        si->name[len] = '\0';
177        si->death.func = svcinfo_death;
178        si->death.ptr = si;
179        si->next = svclist;
180        svclist = si;
181    }
182
183    binder_acquire(bs, ptr);
184    binder_link_to_death(bs, ptr, &si->death);
185    return 0;
186}
187
188int svcmgr_handler(struct binder_state *bs,
189                   struct binder_txn *txn,
190                   struct binder_io *msg,
191                   struct binder_io *reply)
192{
193    struct svcinfo *si;
194    uint16_t *s;
195    unsigned len;
196    void *ptr;
197    uint32_t strict_policy;
198
199//    LOGI("target=%p code=%d pid=%d uid=%d\n",
200//         txn->target, txn->code, txn->sender_pid, txn->sender_euid);
201
202    if (txn->target != svcmgr_handle)
203        return -1;
204
205    // Equivalent to Parcel::enforceInterface(), reading the RPC
206    // header with the strict mode policy mask and the interface name.
207    // Note that we ignore the strict_policy and don't propagate it
208    // further (since we do no outbound RPCs anyway).
209    strict_policy = bio_get_uint32(msg);
210    s = bio_get_string16(msg, &len);
211    if ((len != (sizeof(svcmgr_id) / 2)) ||
212        memcmp(svcmgr_id, s, sizeof(svcmgr_id))) {
213        fprintf(stderr,"invalid id %s\n", str8(s));
214        return -1;
215    }
216
217    switch(txn->code) {
218    case SVC_MGR_GET_SERVICE:
219    case SVC_MGR_CHECK_SERVICE:
220        s = bio_get_string16(msg, &len);
221        ptr = do_find_service(bs, s, len);
222        if (!ptr)
223            break;
224        bio_put_ref(reply, ptr);
225        return 0;
226
227    case SVC_MGR_ADD_SERVICE:
228        s = bio_get_string16(msg, &len);
229        ptr = bio_get_ref(msg);
230        if (do_add_service(bs, s, len, ptr, txn->sender_euid))
231            return -1;
232        break;
233
234    case SVC_MGR_LIST_SERVICES: {
235        unsigned n = bio_get_uint32(msg);
236
237        si = svclist;
238        while ((n-- > 0) && si)
239            si = si->next;
240        if (si) {
241            bio_put_string16(reply, si->name);
242            return 0;
243        }
244        return -1;
245    }
246    default:
247        LOGE("unknown code %d\n", txn->code);
248        return -1;
249    }
250
251    bio_put_uint32(reply, 0);
252    return 0;
253}
254
255int main(int argc, char **argv)
256{
257    struct binder_state *bs;
258    void *svcmgr = BINDER_SERVICE_MANAGER;
259
260    bs = binder_open(128*1024);
261
262    if (binder_become_context_manager(bs)) {
263        LOGE("cannot become context manager (%s)\n", strerror(errno));
264        return -1;
265    }
266
267    svcmgr_handle = svcmgr;
268    binder_loop(bs, svcmgr_handler);
269    return 0;
270}
271