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 <errno.h>
19 #include <fcntl.h>
20 #include <string.h>
21 
22 #include <sys/socket.h>
23 #include <sys/stat.h>
24 #include <sys/ioctl.h>
25 #include <sys/types.h>
26 #include <sys/wait.h>
27 
28 #include <netinet/in.h>
29 #include <arpa/inet.h>
30 
31 #include <linux/wireless.h>
32 
33 #include <openssl/evp.h>
34 #include <openssl/sha.h>
35 
36 #define LOG_TAG "SoftapController"
37 #include <android-base/file.h>
38 #include <android-base/stringprintf.h>
39 #include <cutils/log.h>
40 #include <netutils/ifc.h>
41 #include <private/android_filesystem_config.h>
42 #include "wifi.h"
43 #include "ResponseCode.h"
44 
45 #include "SoftapController.h"
46 
47 using android::base::StringPrintf;
48 using android::base::WriteStringToFile;
49 
50 static const char HOSTAPD_CONF_FILE[]    = "/data/misc/wifi/hostapd.conf";
51 static const char HOSTAPD_BIN_FILE[]    = "/system/bin/hostapd";
52 
SoftapController()53 SoftapController::SoftapController()
54     : mPid(0) {}
55 
~SoftapController()56 SoftapController::~SoftapController() {
57 }
58 
startSoftap()59 int SoftapController::startSoftap() {
60     pid_t pid = 1;
61 
62     if (mPid) {
63         ALOGE("SoftAP is already running");
64         return ResponseCode::SoftapStatusResult;
65     }
66 
67     if (ensure_entropy_file_exists() < 0) {
68         ALOGE("Wi-Fi entropy file was not created");
69     }
70 
71     if ((pid = fork()) < 0) {
72         ALOGE("fork failed (%s)", strerror(errno));
73         return ResponseCode::ServiceStartFailed;
74     }
75 
76     if (!pid) {
77         ensure_entropy_file_exists();
78         if (execl(HOSTAPD_BIN_FILE, HOSTAPD_BIN_FILE,
79                   "-e", WIFI_ENTROPY_FILE,
80                   HOSTAPD_CONF_FILE, (char *) NULL)) {
81             ALOGE("execl failed (%s)", strerror(errno));
82         }
83         ALOGE("SoftAP failed to start");
84         return ResponseCode::ServiceStartFailed;
85     } else {
86         mPid = pid;
87         ALOGD("SoftAP started successfully");
88         usleep(AP_BSS_START_DELAY);
89     }
90     return ResponseCode::SoftapStatusResult;
91 }
92 
stopSoftap()93 int SoftapController::stopSoftap() {
94 
95     if (mPid == 0) {
96         ALOGE("SoftAP is not running");
97         return ResponseCode::SoftapStatusResult;
98     }
99 
100     ALOGD("Stopping the SoftAP service...");
101     kill(mPid, SIGTERM);
102     waitpid(mPid, NULL, 0);
103 
104     mPid = 0;
105     ALOGD("SoftAP stopped successfully");
106     usleep(AP_BSS_STOP_DELAY);
107     return ResponseCode::SoftapStatusResult;
108 }
109 
isSoftapStarted()110 bool SoftapController::isSoftapStarted() {
111     return (mPid != 0);
112 }
113 
114 /*
115  * Arguments:
116  *  argv[2] - wlan interface
117  *  argv[3] - SSID
118  *  argv[4] - Broadcast/Hidden
119  *  argv[5] - Channel
120  *  argv[6] - Security
121  *  argv[7] - Key
122  */
setSoftap(int argc,char * argv[])123 int SoftapController::setSoftap(int argc, char *argv[]) {
124     int hidden = 0;
125     int channel = AP_CHANNEL_DEFAULT;
126 
127     if (argc < 5) {
128         ALOGE("Softap set is missing arguments. Please use:");
129         ALOGE("softap <wlan iface> <SSID> <hidden/broadcast> <channel> <wpa2?-psk|open> <passphrase>");
130         return ResponseCode::CommandSyntaxError;
131     }
132 
133     if (!strcasecmp(argv[4], "hidden"))
134         hidden = 1;
135 
136     if (argc >= 5) {
137         channel = atoi(argv[5]);
138         if (channel <= 0)
139             channel = AP_CHANNEL_DEFAULT;
140     }
141 
142     std::string wbuf(StringPrintf("interface=%s\n"
143             "driver=nl80211\n"
144             "ctrl_interface=/data/misc/wifi/hostapd\n"
145             "ssid=%s\n"
146             "channel=%d\n"
147             "ieee80211n=1\n"
148             "hw_mode=%c\n"
149             "ignore_broadcast_ssid=%d\n"
150             "wowlan_triggers=any\n",
151             argv[2], argv[3], channel, (channel <= 14) ? 'g' : 'a', hidden));
152 
153     std::string fbuf;
154     if (argc > 7) {
155         char psk_str[2*SHA256_DIGEST_LENGTH+1];
156         if (!strcmp(argv[6], "wpa-psk")) {
157             if (!generatePsk(argv[3], argv[7], psk_str)) {
158                 return ResponseCode::OperationFailed;
159             }
160             fbuf = StringPrintf("%swpa=3\nwpa_pairwise=TKIP CCMP\nwpa_psk=%s\n", wbuf.c_str(), psk_str);
161         } else if (!strcmp(argv[6], "wpa2-psk")) {
162             if (!generatePsk(argv[3], argv[7], psk_str)) {
163                 return ResponseCode::OperationFailed;
164             }
165             fbuf = StringPrintf("%swpa=2\nrsn_pairwise=CCMP\nwpa_psk=%s\n", wbuf.c_str(), psk_str);
166         } else if (!strcmp(argv[6], "open")) {
167             fbuf = wbuf;
168         }
169     } else if (argc > 6) {
170         if (!strcmp(argv[6], "open")) {
171             fbuf = wbuf;
172         }
173     } else {
174         fbuf = wbuf;
175     }
176 
177     if (!WriteStringToFile(fbuf, HOSTAPD_CONF_FILE, 0660, AID_SYSTEM, AID_WIFI)) {
178         ALOGE("Cannot write to \"%s\": %s", HOSTAPD_CONF_FILE, strerror(errno));
179         return ResponseCode::OperationFailed;
180     }
181     return ResponseCode::SoftapStatusResult;
182 }
183 
184 /*
185  * Arguments:
186  *	argv[2] - interface name
187  *	argv[3] - AP or P2P or STA
188  */
fwReloadSoftap(int argc,char * argv[])189 int SoftapController::fwReloadSoftap(int argc, char *argv[])
190 {
191     char *fwpath = NULL;
192 
193     if (argc < 4) {
194         ALOGE("SoftAP fwreload is missing arguments. Please use: softap <wlan iface> <AP|P2P|STA>");
195         return ResponseCode::CommandSyntaxError;
196     }
197 
198     if (strcmp(argv[3], "AP") == 0) {
199         fwpath = (char *)wifi_get_fw_path(WIFI_GET_FW_PATH_AP);
200     } else if (strcmp(argv[3], "P2P") == 0) {
201         fwpath = (char *)wifi_get_fw_path(WIFI_GET_FW_PATH_P2P);
202     } else if (strcmp(argv[3], "STA") == 0) {
203         fwpath = (char *)wifi_get_fw_path(WIFI_GET_FW_PATH_STA);
204     } else {
205         return ResponseCode::CommandParameterError;
206     }
207     if (!fwpath) {
208         ALOGE("Softap fwReload - NULL path for %s", argv[3]);
209         return ResponseCode::SoftapStatusResult;
210     }
211     if (wifi_change_fw_path((const char *)fwpath)) {
212         ALOGE("Softap fwReload failed");
213         return ResponseCode::OperationFailed;
214     }
215     else {
216         ALOGD("Softap fwReload - Ok");
217     }
218     return ResponseCode::SoftapStatusResult;
219 }
220 
generatePsk(char * ssid,char * passphrase,char * psk_str)221 bool SoftapController::generatePsk(char *ssid, char *passphrase, char *psk_str) {
222     unsigned char psk[SHA256_DIGEST_LENGTH];
223 
224     // Use the PKCS#5 PBKDF2 with 4096 iterations
225     if (PKCS5_PBKDF2_HMAC_SHA1(passphrase, strlen(passphrase),
226                                reinterpret_cast<const unsigned char *>(ssid),
227                                strlen(ssid), 4096, SHA256_DIGEST_LENGTH,
228                                psk) != 1) {
229         ALOGE("Cannot generate PSK using PKCS#5 PBKDF2");
230         return false;
231     }
232 
233     for (int j=0; j < SHA256_DIGEST_LENGTH; j++) {
234         sprintf(&psk_str[j*2], "%02x", psk[j]);
235     }
236 
237     return true;
238 }
239