1 /*
2  * Copyright 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 "hardware_legacy/wifi.h"
18 
19 #include <fcntl.h>
20 #include <stdlib.h>
21 #include <unistd.h>
22 
23 #include <android-base/logging.h>
24 #include <cutils/misc.h>
25 #include <cutils/properties.h>
26 #include <sys/syscall.h>
27 
28 extern "C" int init_module(void *, unsigned long, const char *);
29 extern "C" int delete_module(const char *, unsigned int);
30 
31 #ifndef WIFI_DRIVER_FW_PATH_STA
32 #define WIFI_DRIVER_FW_PATH_STA NULL
33 #endif
34 #ifndef WIFI_DRIVER_FW_PATH_AP
35 #define WIFI_DRIVER_FW_PATH_AP NULL
36 #endif
37 #ifndef WIFI_DRIVER_FW_PATH_P2P
38 #define WIFI_DRIVER_FW_PATH_P2P NULL
39 #endif
40 
41 #ifndef WIFI_DRIVER_MODULE_ARG
42 #define WIFI_DRIVER_MODULE_ARG ""
43 #endif
44 
45 static const char DRIVER_PROP_NAME[] = "wlan.driver.status";
46 static bool is_driver_loaded = false;
47 #ifdef WIFI_DRIVER_MODULE_PATH
48 static const char DRIVER_MODULE_NAME[] = WIFI_DRIVER_MODULE_NAME;
49 static const char DRIVER_MODULE_TAG[] = WIFI_DRIVER_MODULE_NAME " ";
50 static const char DRIVER_MODULE_PATH[] = WIFI_DRIVER_MODULE_PATH;
51 static const char DRIVER_MODULE_ARG[] = WIFI_DRIVER_MODULE_ARG;
52 static const char MODULE_FILE[] = "/proc/modules";
53 #endif
54 
insmod(const char * filename,const char * args)55 static int insmod(const char *filename, const char *args) {
56   int ret;
57   int fd;
58 
59   fd = TEMP_FAILURE_RETRY(open(filename, O_RDONLY | O_CLOEXEC | O_NOFOLLOW));
60   if (fd < 0) {
61     PLOG(ERROR) << "Failed to open " << filename;
62     return -1;
63   }
64 
65   ret = syscall(__NR_finit_module, fd, args, 0);
66 
67   close(fd);
68   if (ret < 0) {
69     PLOG(ERROR) << "finit_module return: " << ret;
70   }
71 
72   return ret;
73 }
74 
rmmod(const char * modname)75 static int rmmod(const char *modname) {
76   int ret = -1;
77   int maxtry = 10;
78 
79   while (maxtry-- > 0) {
80     ret = delete_module(modname, O_NONBLOCK | O_EXCL);
81     if (ret < 0 && errno == EAGAIN)
82       usleep(500000);
83     else
84       break;
85   }
86 
87   if (ret != 0)
88     PLOG(DEBUG) << "Unable to unload driver module '" << modname << "'";
89   return ret;
90 }
91 
92 #ifdef WIFI_DRIVER_STATE_CTRL_PARAM
wifi_change_driver_state(const char * state)93 int wifi_change_driver_state(const char *state) {
94   int len;
95   int fd;
96   int ret = 0;
97 
98   if (!state) return -1;
99   fd = TEMP_FAILURE_RETRY(open(WIFI_DRIVER_STATE_CTRL_PARAM, O_WRONLY));
100   if (fd < 0) {
101     PLOG(ERROR) << "Failed to open driver state control param";
102     return -1;
103   }
104   len = strlen(state) + 1;
105   if (TEMP_FAILURE_RETRY(write(fd, state, len)) != len) {
106     PLOG(ERROR) << "Failed to write driver state control param";
107     ret = -1;
108   }
109   close(fd);
110   return ret;
111 }
112 #endif
113 
is_wifi_driver_loaded()114 int is_wifi_driver_loaded() {
115   char driver_status[PROPERTY_VALUE_MAX];
116 #ifdef WIFI_DRIVER_MODULE_PATH
117   FILE *proc;
118   char line[sizeof(DRIVER_MODULE_TAG) + 10];
119 #endif
120 
121   if (!property_get(DRIVER_PROP_NAME, driver_status, NULL)) {
122     return 0; /* driver not loaded */
123   }
124 
125   if (!is_driver_loaded) {
126     return 0;
127   } /* driver not loaded */
128 
129 #ifdef WIFI_DRIVER_MODULE_PATH
130   /*
131    * If the property says the driver is loaded, check to
132    * make sure that the property setting isn't just left
133    * over from a previous manual shutdown or a runtime
134    * crash.
135    */
136   if ((proc = fopen(MODULE_FILE, "r")) == NULL) {
137     PLOG(WARNING) << "Could not open " << MODULE_FILE;
138     is_driver_loaded = false;
139     if (strcmp(driver_status, "unloaded") != 0) {
140       property_set(DRIVER_PROP_NAME, "unloaded");
141     }
142     return 0;
143   }
144   while ((fgets(line, sizeof(line), proc)) != NULL) {
145     if (strncmp(line, DRIVER_MODULE_TAG, strlen(DRIVER_MODULE_TAG)) == 0) {
146       fclose(proc);
147       return 1;
148     }
149   }
150   fclose(proc);
151   is_driver_loaded = false;
152   if (strcmp(driver_status, "unloaded") != 0) {
153     property_set(DRIVER_PROP_NAME, "unloaded");
154   }
155   return 0;
156 #else
157   return 1;
158 #endif
159 }
160 
wifi_load_driver()161 int wifi_load_driver() {
162 #ifdef WIFI_DRIVER_MODULE_PATH
163   if (is_wifi_driver_loaded()) {
164     return 0;
165   }
166 
167   if (insmod(DRIVER_MODULE_PATH, DRIVER_MODULE_ARG) < 0) return -1;
168 #endif
169 
170 #ifdef WIFI_DRIVER_STATE_CTRL_PARAM
171   if (is_wifi_driver_loaded()) {
172     return 0;
173   }
174 
175   if (wifi_change_driver_state(WIFI_DRIVER_STATE_ON) < 0) {
176 #ifdef WIFI_DRIVER_MODULE_PATH
177     PLOG(WARNING) << "Driver unloading, err='fail to change driver state'";
178     if (rmmod(DRIVER_MODULE_NAME) == 0) {
179       PLOG(DEBUG) << "Driver unloaded";
180     } else {
181       // Set driver prop to "ok", expect HL to restart Wi-Fi.
182       PLOG(DEBUG) << "Driver unload failed! set driver prop to 'ok'.";
183       property_set(DRIVER_PROP_NAME, "ok");
184     }
185 #endif
186     return -1;
187   }
188 #endif
189   is_driver_loaded = true;
190   return 0;
191 }
192 
wifi_unload_driver()193 int wifi_unload_driver() {
194   if (!is_wifi_driver_loaded()) {
195     return 0;
196   }
197 #ifdef WIFI_DRIVER_MODULE_PATH
198   if (rmmod(DRIVER_MODULE_NAME) == 0) {
199     int count = 20; /* wait at most 10 seconds for completion */
200     while (count-- > 0) {
201       if (!is_wifi_driver_loaded()) break;
202       usleep(500000);
203     }
204     usleep(500000); /* allow card removal */
205     if (count) {
206       return 0;
207     }
208     return -1;
209   } else
210     return -1;
211 #else
212 #ifdef WIFI_DRIVER_STATE_CTRL_PARAM
213   if (is_wifi_driver_loaded()) {
214     if (wifi_change_driver_state(WIFI_DRIVER_STATE_OFF) < 0) return -1;
215   }
216 #endif
217   is_driver_loaded = false;
218   property_set(DRIVER_PROP_NAME, "unloaded");
219   return 0;
220 #endif
221 }
222 
wifi_get_fw_path(int fw_type)223 const char *wifi_get_fw_path(int fw_type) {
224   switch (fw_type) {
225     case WIFI_GET_FW_PATH_STA:
226       return WIFI_DRIVER_FW_PATH_STA;
227     case WIFI_GET_FW_PATH_AP:
228       return WIFI_DRIVER_FW_PATH_AP;
229     case WIFI_GET_FW_PATH_P2P:
230       return WIFI_DRIVER_FW_PATH_P2P;
231   }
232   return NULL;
233 }
234 
wifi_change_fw_path(const char * fwpath)235 int wifi_change_fw_path(const char *fwpath) {
236   int len;
237   int fd;
238   int ret = 0;
239 
240   if (!fwpath) return ret;
241   fd = TEMP_FAILURE_RETRY(open(WIFI_DRIVER_FW_PATH_PARAM, O_WRONLY));
242   if (fd < 0) {
243     PLOG(ERROR) << "Failed to open wlan fw path param";
244     return -1;
245   }
246   len = strlen(fwpath) + 1;
247   if (TEMP_FAILURE_RETRY(write(fd, fwpath, len)) != len) {
248     PLOG(ERROR) << "Failed to write wlan fw path param";
249     ret = -1;
250   }
251   close(fd);
252   return ret;
253 }
254