service_manager.c revision a553c25b33c99b345cf1c8688f8df0ed8df14e5a 
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    { AID_MEDIA, "media.audio_flinger" },
31    { AID_MEDIA, "media.player" },
32    { AID_MEDIA, "media.camera" },
33    { AID_MEDIA, "media.audio_policy" },
34    { AID_RADIO, "radio.phone" },
35    { AID_RADIO, "radio.sms" },
36    { AID_RADIO, "radio.phonesubinfo" },
37    { AID_RADIO, "radio.simphonebook" },
38/* TODO: remove after phone services are updated: */
39    { AID_RADIO, "phone" },
40    { AID_RADIO, "isms" },
41    { AID_RADIO, "iphonesubinfo" },
42    { AID_RADIO, "simphonebook" },
43};
44
45void *svcmgr_handle;
46
47const char *str8(uint16_t *x)
48{
49    static char buf[128];
50    unsigned max = 127;
51    char *p = buf;
52
53    if (x) {
54        while (*x && max--) {
55            *p++ = *x++;
56        }
57    }
58    *p++ = 0;
59    return buf;
60}
61
62int str16eq(uint16_t *a, const char *b)
63{
64    while (*a && *b)
65        if (*a++ != *b++) return 0;
66    if (*a || *b)
67        return 0;
68    return 1;
69}
70
71int svc_can_register(unsigned uid, uint16_t *name)
72{
73    unsigned n;
74
75    if ((uid == 0) || (uid == AID_SYSTEM))
76        return 1;
77
78    for (n = 0; n < sizeof(allowed) / sizeof(allowed[0]); n++)
79        if ((uid == allowed[n].uid) && str16eq(name, allowed[n].name))
80            return 1;
81
82    return 0;
83}
84
85struct svcinfo
86{
87    struct svcinfo *next;
88    void *ptr;
89    struct binder_death death;
90    unsigned len;
91    uint16_t name[0];
92};
93
94struct svcinfo *svclist = 0;
95
96struct svcinfo *find_svc(uint16_t *s16, unsigned len)
97{
98    struct svcinfo *si;
99
100    for (si = svclist; si; si = si->next) {
101        if ((len == si->len) &&
102            !memcmp(s16, si->name, len * sizeof(uint16_t))) {
103            return si;
104        }
105    }
106    return 0;
107}
108
109void svcinfo_death(struct binder_state *bs, void *ptr)
110{
111    struct svcinfo *si = ptr;
112    LOGI("service '%s' died\n", str8(si->name));
113    if (si->ptr) {
114        binder_release(bs, si->ptr);
115        si->ptr = 0;
116    }
117}
118
119uint16_t svcmgr_id[] = {
120    'a','n','d','r','o','i','d','.','o','s','.',
121    'I','S','e','r','v','i','c','e','M','a','n','a','g','e','r'
122};
123
124
125void *do_find_service(struct binder_state *bs, uint16_t *s, unsigned len)
126{
127    struct svcinfo *si;
128    si = find_svc(s, len);
129
130//    LOGI("check_service('%s') ptr = %p\n", str8(s), si ? si->ptr : 0);
131    if (si && si->ptr) {
132        return si->ptr;
133    } else {
134        return 0;
135    }
136}
137
138int do_add_service(struct binder_state *bs,
139                   uint16_t *s, unsigned len,
140                   void *ptr, unsigned uid)
141{
142    struct svcinfo *si;
143//    LOGI("add_service('%s',%p) uid=%d\n", str8(s), ptr, uid);
144
145    if (!ptr || (len == 0) || (len > 127))
146        return -1;
147
148    if (!svc_can_register(uid, s)) {
149        LOGE("add_service('%s',%p) uid=%d - PERMISSION DENIED\n",
150             str8(s), ptr, uid);
151        return -1;
152    }
153
154    si = find_svc(s, len);
155    if (si) {
156        if (si->ptr) {
157            LOGE("add_service('%s',%p) uid=%d - ALREADY REGISTERED\n",
158                 str8(s), ptr, uid);
159            return -1;
160        }
161        si->ptr = ptr;
162    } else {
163        si = malloc(sizeof(*si) + (len + 1) * sizeof(uint16_t));
164        if (!si) {
165            LOGE("add_service('%s',%p) uid=%d - OUT OF MEMORY\n",
166                 str8(s), ptr, uid);
167            return -1;
168        }
169        si->ptr = ptr;
170        si->len = len;
171        memcpy(si->name, s, (len + 1) * sizeof(uint16_t));
172        si->name[len] = '\0';
173        si->death.func = svcinfo_death;
174        si->death.ptr = si;
175        si->next = svclist;
176        svclist = si;
177    }
178
179    binder_acquire(bs, ptr);
180    binder_link_to_death(bs, ptr, &si->death);
181    return 0;
182}
183
184int svcmgr_handler(struct binder_state *bs,
185                   struct binder_txn *txn,
186                   struct binder_io *msg,
187                   struct binder_io *reply)
188{
189    struct svcinfo *si;
190    uint16_t *s;
191    unsigned len;
192    void *ptr;
193
194//    LOGI("target=%p code=%d pid=%d uid=%d\n",
195//         txn->target, txn->code, txn->sender_pid, txn->sender_euid);
196
197    if (txn->target != svcmgr_handle)
198        return -1;
199
200    s = bio_get_string16(msg, &len);
201
202    if ((len != (sizeof(svcmgr_id) / 2)) ||
203        memcmp(svcmgr_id, s, sizeof(svcmgr_id))) {
204        fprintf(stderr,"invalid id %s\n", str8(s));
205        return -1;
206    }
207
208    switch(txn->code) {
209    case SVC_MGR_GET_SERVICE:
210    case SVC_MGR_CHECK_SERVICE:
211        s = bio_get_string16(msg, &len);
212        ptr = do_find_service(bs, s, len);
213        if (!ptr)
214            break;
215        bio_put_ref(reply, ptr);
216        return 0;
217
218    case SVC_MGR_ADD_SERVICE:
219        s = bio_get_string16(msg, &len);
220        ptr = bio_get_ref(msg);
221        if (do_add_service(bs, s, len, ptr, txn->sender_euid))
222            return -1;
223        break;
224
225    case SVC_MGR_LIST_SERVICES: {
226        unsigned n = bio_get_uint32(msg);
227
228        si = svclist;
229        while ((n-- > 0) && si)
230            si = si->next;
231        if (si) {
232            bio_put_string16(reply, si->name);
233            return 0;
234        }
235        return -1;
236    }
237    default:
238        LOGE("unknown code %d\n", txn->code);
239        return -1;
240    }
241
242    bio_put_uint32(reply, 0);
243    return 0;
244}
245
246int main(int argc, char **argv)
247{
248    struct binder_state *bs;
249    void *svcmgr = BINDER_SERVICE_MANAGER;
250
251    bs = binder_open(128*1024);
252
253    if (binder_become_context_manager(bs)) {
254        LOGE("cannot become context manager (%s)\n", strerror(errno));
255        return -1;
256    }
257
258    svcmgr_handle = svcmgr;
259    binder_loop(bs, svcmgr_handler);
260    return 0;
261}
262