1 /*
2 * Copyright (C) 2008 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 <stdlib.h>
18 #include <sys/socket.h>
19 #include <sys/select.h>
20 #include <sys/time.h>
21 #include <sys/types.h>
22 #include <errno.h>
23 #include <pthread.h>
24
25 #define LOG_TAG "WifiScanner"
26 #include <cutils/log.h>
27
28 #include "WifiScanner.h"
29 #include "Supplicant.h"
30
31 extern "C" int pthread_cancel(pthread_t thread);
32
WifiScanner(Supplicant * suppl,int period)33 WifiScanner::WifiScanner(Supplicant *suppl, int period) {
34 mSuppl = suppl;
35 mPeriod = period;
36 mActive = false;
37 }
38
start(bool active)39 int WifiScanner::start(bool active) {
40 mActive = active;
41
42 if(pipe(mCtrlPipe))
43 return -1;
44
45 if (pthread_create(&mThread, NULL, WifiScanner::threadStart, this))
46 return -1;
47 return 0;
48 }
49
threadStart(void * obj)50 void *WifiScanner::threadStart(void *obj) {
51 WifiScanner *me = reinterpret_cast<WifiScanner *>(obj);
52 me->run();
53 pthread_exit(NULL);
54 return NULL;
55 }
56
stop()57 int WifiScanner::stop() {
58 char c = 0;
59
60 if (write(mCtrlPipe[1], &c, 1) != 1) {
61 LOGE("Error writing to control pipe (%s)", strerror(errno));
62 return -1;
63 }
64
65 void *ret;
66 if (pthread_join(mThread, &ret)) {
67 LOGE("Error joining to scanner thread (%s)", strerror(errno));
68 return -1;
69 }
70
71 close(mCtrlPipe[0]);
72 close(mCtrlPipe[1]);
73 return 0;
74 }
75
run()76 void WifiScanner::run() {
77 LOGD("Starting wifi scanner (active = %d)", mActive);
78
79 while(1) {
80 fd_set read_fds;
81 struct timeval to;
82 int rc = 0;
83
84 to.tv_usec = 0;
85 to.tv_sec = mPeriod;
86
87 FD_ZERO(&read_fds);
88 FD_SET(mCtrlPipe[0], &read_fds);
89
90 if (mSuppl->triggerScan(mActive)) {
91 LOGW("Error triggering scan (%s)", strerror(errno));
92 }
93
94 if ((rc = select(mCtrlPipe[0] + 1, &read_fds, NULL, NULL, &to)) < 0) {
95 LOGE("select failed (%s) - sleeping for one scanner period", strerror(errno));
96 sleep(mPeriod);
97 continue;
98 } else if (!rc) {
99 } else if (FD_ISSET(mCtrlPipe[0], &read_fds))
100 break;
101 } // while
102 LOGD("Stopping wifi scanner");
103 }
104