1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "wifi_system/supplicant_manager.h"
18
19 #include <android-base/logging.h>
20 #include <cutils/properties.h>
21 #include <fcntl.h>
22 #include <string.h>
23 #include <sys/stat.h>
24 #include <sys/system_properties.h>
25 #include <unistd.h>
26
27 namespace android {
28 namespace wifi_system {
29 namespace {
30
31 const char kSupplicantInitProperty[] = "init.svc.wpa_supplicant";
32 const char kSupplicantServiceName[] = "wpa_supplicant";
33
34 } // namespace
35
StartSupplicant()36 bool SupplicantManager::StartSupplicant() {
37 char supp_status[PROPERTY_VALUE_MAX] = {'\0'};
38 int count = 200; /* wait at most 20 seconds for completion */
39 const prop_info* pi;
40 unsigned serial = 0;
41
42 /* Check whether already running */
43 if (property_get(kSupplicantInitProperty, supp_status, NULL) &&
44 strcmp(supp_status, "running") == 0) {
45 return true;
46 }
47
48 /*
49 * Get a reference to the status property, so we can distinguish
50 * the case where it goes stopped => running => stopped (i.e.,
51 * it start up, but fails right away) from the case in which
52 * it starts in the stopped state and never manages to start
53 * running at all.
54 */
55 pi = __system_property_find(kSupplicantInitProperty);
56 if (pi != NULL) {
57 serial = __system_property_serial(pi);
58 }
59
60 property_set("ctl.start", kSupplicantServiceName);
61 sched_yield();
62
63 while (count-- > 0) {
64 if (pi == NULL) {
65 pi = __system_property_find(kSupplicantInitProperty);
66 }
67 if (pi != NULL) {
68 /*
69 * property serial updated means that init process is scheduled
70 * after we sched_yield, further property status checking is based on this
71 */
72 if (__system_property_serial(pi) != serial) {
73 __system_property_read(pi, NULL, supp_status);
74 if (strcmp(supp_status, "running") == 0) {
75 return true;
76 } else if (strcmp(supp_status, "stopped") == 0) {
77 return false;
78 }
79 }
80 }
81 usleep(100000);
82 }
83 return false;
84 }
85
StopSupplicant()86 bool SupplicantManager::StopSupplicant() {
87 char supp_status[PROPERTY_VALUE_MAX] = {'\0'};
88 int count = 200; /* wait at most 20 seconds for completion */
89
90 /* Check whether supplicant already stopped */
91 if (property_get(kSupplicantInitProperty, supp_status, NULL) &&
92 strcmp(supp_status, "stopped") == 0) {
93 return true;
94 }
95
96 property_set("ctl.stop", kSupplicantServiceName);
97 sched_yield();
98
99 while (count-- > 0) {
100 if (property_get(kSupplicantInitProperty, supp_status, NULL)) {
101 if (strcmp(supp_status, "stopped") == 0) return true;
102 }
103 usleep(100000);
104 }
105 LOG(ERROR) << "Failed to stop supplicant";
106 return false;
107 }
108
IsSupplicantRunning()109 bool SupplicantManager::IsSupplicantRunning() {
110 char supp_status[PROPERTY_VALUE_MAX] = {'\0'};
111 if (property_get(kSupplicantInitProperty, supp_status, NULL)) {
112 return strcmp(supp_status, "running") == 0;
113 }
114 return false; // Failed to read service status from init.
115 }
116
117 } // namespace wifi_system
118 } // namespace android
119