SoftapController.cpp revision 7e9eb7b48345af69283afa7ca58d3be0a329931b 
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 <cutils/log.h>
38#include <netutils/ifc.h>
39#include <private/android_filesystem_config.h>
40#include "wifi.h"
41
42#include "SoftapController.h"
43
44static const char HOSTAPD_CONF_FILE[]    = "/data/misc/wifi/hostapd.conf";
45
46SoftapController::SoftapController() {
47    mPid = 0;
48    mSock = socket(AF_INET, SOCK_DGRAM, 0);
49    if (mSock < 0)
50        ALOGE("Failed to open socket");
51}
52
53SoftapController::~SoftapController() {
54    if (mSock >= 0)
55        close(mSock);
56}
57
58int SoftapController::startSoftap() {
59    pid_t pid = 1;
60    int ret = 0;
61
62    if (mPid) {
63        ALOGE("Softap already started");
64        return 0;
65    }
66    if (mSock < 0) {
67        ALOGE("Softap startap - failed to open socket");
68        return -1;
69    }
70
71    if ((pid = fork()) < 0) {
72        ALOGE("fork failed (%s)", strerror(errno));
73        return -1;
74    }
75
76    if (!pid) {
77        ensure_entropy_file_exists();
78        if (execl("/system/bin/hostapd", "/system/bin/hostapd",
79                  "-e", WIFI_ENTROPY_FILE,
80                  HOSTAPD_CONF_FILE, (char *) NULL)) {
81            ALOGE("execl failed (%s)", strerror(errno));
82        }
83        ALOGE("Should never get here!");
84        return -1;
85    } else {
86        mPid = pid;
87        ALOGD("Softap startap - Ok");
88        usleep(AP_BSS_START_DELAY);
89    }
90    return ret;
91
92}
93
94int SoftapController::stopSoftap() {
95
96    if (mPid == 0) {
97        ALOGE("Softap already stopped");
98        return 0;
99    }
100
101    ALOGD("Stopping Softap service");
102    kill(mPid, SIGTERM);
103    waitpid(mPid, NULL, 0);
104
105    if (mSock < 0) {
106        ALOGE("Softap stopap - failed to open socket");
107        return -1;
108    }
109    mPid = 0;
110    ALOGD("Softap service stopped");
111    usleep(AP_BSS_STOP_DELAY);
112    return 0;
113}
114
115bool SoftapController::isSoftapStarted() {
116    return (mPid != 0 ? true : false);
117}
118
119/*
120 * Arguments:
121 *      argv[2] - wlan interface
122 *      argv[3] - SSID
123 *	argv[4] - Security
124 *	argv[5] - Key
125 *	argv[6] - Channel
126 *	argv[7] - Preamble
127 *	argv[8] - Max SCB
128 */
129int SoftapController::setSoftap(int argc, char *argv[]) {
130    char psk_str[2*SHA256_DIGEST_LENGTH+1];
131    int ret = 0, i = 0, fd;
132    char *ssid, *iface;
133
134    if (mSock < 0) {
135        ALOGE("Softap set - failed to open socket");
136        return -1;
137    }
138    if (argc < 4) {
139        ALOGE("Softap set - missing arguments");
140        return -1;
141    }
142
143    iface = argv[2];
144
145    char *wbuf = NULL;
146    char *fbuf = NULL;
147
148    if (argc > 3) {
149        ssid = argv[3];
150    } else {
151        ssid = (char *)"AndroidAP";
152    }
153
154    asprintf(&wbuf, "interface=%s\ndriver=nl80211\nctrl_interface="
155            "/data/misc/wifi/hostapd\nssid=%s\nchannel=6\nieee80211n=1\n",
156            iface, ssid);
157
158    if (argc > 4) {
159        if (!strcmp(argv[4], "wpa-psk")) {
160            generatePsk(ssid, argv[5], psk_str);
161            asprintf(&fbuf, "%swpa=1\nwpa_pairwise=TKIP CCMP\nwpa_psk=%s\n", wbuf, psk_str);
162        } else if (!strcmp(argv[4], "wpa2-psk")) {
163            generatePsk(ssid, argv[5], psk_str);
164            asprintf(&fbuf, "%swpa=2\nrsn_pairwise=CCMP\nwpa_psk=%s\n", wbuf, psk_str);
165        } else if (!strcmp(argv[4], "open")) {
166            asprintf(&fbuf, "%s", wbuf);
167        }
168    } else {
169        asprintf(&fbuf, "%s", wbuf);
170    }
171
172    fd = open(HOSTAPD_CONF_FILE, O_CREAT | O_TRUNC | O_WRONLY, 0660);
173    if (fd < 0) {
174        ALOGE("Cannot update \"%s\": %s", HOSTAPD_CONF_FILE, strerror(errno));
175        free(wbuf);
176        free(fbuf);
177        return -1;
178    }
179    if (write(fd, fbuf, strlen(fbuf)) < 0) {
180        ALOGE("Cannot write to \"%s\": %s", HOSTAPD_CONF_FILE, strerror(errno));
181        ret = -1;
182    }
183    close(fd);
184    free(wbuf);
185    free(fbuf);
186
187    /* Note: apparently open can fail to set permissions correctly at times */
188    if (chmod(HOSTAPD_CONF_FILE, 0660) < 0) {
189        ALOGE("Error changing permissions of %s to 0660: %s",
190                HOSTAPD_CONF_FILE, strerror(errno));
191        unlink(HOSTAPD_CONF_FILE);
192        return -1;
193    }
194
195    if (chown(HOSTAPD_CONF_FILE, AID_SYSTEM, AID_WIFI) < 0) {
196        ALOGE("Error changing group ownership of %s to %d: %s",
197                HOSTAPD_CONF_FILE, AID_WIFI, strerror(errno));
198        unlink(HOSTAPD_CONF_FILE);
199        return -1;
200    }
201
202    return ret;
203}
204
205void SoftapController::generatePsk(char *ssid, char *passphrase, char *psk_str) {
206    unsigned char psk[SHA256_DIGEST_LENGTH];
207    int j;
208    // Use the PKCS#5 PBKDF2 with 4096 iterations
209    PKCS5_PBKDF2_HMAC_SHA1(passphrase, strlen(passphrase),
210            reinterpret_cast<const unsigned char *>(ssid), strlen(ssid),
211            4096, SHA256_DIGEST_LENGTH, psk);
212    for (j=0; j < SHA256_DIGEST_LENGTH; j++) {
213        sprintf(&psk_str[j<<1], "%02x", psk[j]);
214    }
215    psk_str[j<<1] = '\0';
216}
217
218
219/*
220 * Arguments:
221 *	argv[2] - interface name
222 *	argv[3] - AP or STA
223 */
224int SoftapController::fwReloadSoftap(int argc, char *argv[])
225{
226    int ret, i = 0;
227    char *iface;
228    char *fwpath;
229
230    if (mSock < 0) {
231        ALOGE("Softap fwrealod - failed to open socket");
232        return -1;
233    }
234    if (argc < 4) {
235        ALOGE("Softap fwreload - missing arguments");
236        return -1;
237    }
238
239    iface = argv[2];
240
241    if (strcmp(argv[3], "AP") == 0) {
242        fwpath = (char *)wifi_get_fw_path(WIFI_GET_FW_PATH_AP);
243    } else if (strcmp(argv[3], "P2P") == 0) {
244        fwpath = (char *)wifi_get_fw_path(WIFI_GET_FW_PATH_P2P);
245    } else {
246        fwpath = (char *)wifi_get_fw_path(WIFI_GET_FW_PATH_STA);
247    }
248    if (!fwpath)
249        return -1;
250    ret = wifi_change_fw_path((const char *)fwpath);
251    if (ret) {
252        ALOGE("Softap fwReload - failed: %d", ret);
253    }
254    else {
255        ALOGD("Softap fwReload - Ok");
256    }
257    return ret;
258}
259
260int SoftapController::clientsSoftap(char **retbuf)
261{
262    /* TODO: implement over hostapd */
263    return 0;
264}
265