OpenHarmony角落里的知识：WPA

WPA_Supplicant连接方式简析

#创作者激励# #跟着小白一起学鸿蒙# WPA_Supplicant连接方式简析-鸿蒙开发者社区

/third_party/wpa_supplicant
|-- CONTRIBUTIONS            # 贡献说明
|-- COPYING               # 版权说明
|-- wpa_supplicant-2.9          # 轻量级系统的wpa_supplicant
|  |-- hostapd             # Wi-Fi热点相关功能（Access Point）
|  |-- hs20               # 热点2.0（Hotspot2.0）相关功能
|  |-- src               # Wi-Fi热点与Wi-Fi接入点共用的代码
|  |-- wpa_supplicant          # Wi-Fi接入相关功能（Station）
|  `-- wpa_supplicant_lib        # OpenHarmony对Wi-Fi新开发的业务代码
`-- wpa_supplicant-2.9_standard     # 标准系统的wpa_supplicant
|  |-- hostapd             # Wi-Fi热点相关功能（Access Point）
|  |-- hs20               # 热点2.0（Hotspot2.0）相关功能
|  |-- src               # Wi-Fi热点与Wi-Fi接入点共用的代码
|  |-- wpa_supplicant          # Wi-Fi接入相关功能（Station）
|  `-- wpa_supplicant_lib        # OpenHarmony对Wi-Fi新开发的业务代码

WPA_Supplicant支持的连接方式
```
struct wpa_ctrl {
#ifdef CONFIG_CTRL_IFACE_UDPint s;
#ifdef CONFIG_CTRL_IFACE_UDP_IPV6struct sockaddr_in6 local;struct sockaddr_in6 dest;
#else /* CONFIG_CTRL_IFACE_UDP_IPV6 */struct sockaddr_in local;struct sockaddr_in dest;
#endif /* CONFIG_CTRL_IFACE_UDP_IPV6 */char *cookie;char *remote_ifname;char *remote_ip;
#endif /* CONFIG_CTRL_IFACE_UDP */
#ifdef CONFIG_CTRL_IFACE_UNIXint s;struct sockaddr_un local;struct sockaddr_un dest;
#endif /* CONFIG_CTRL_IFACE_UNIX */
#ifdef CONFIG_CTRL_IFACE_NAMED_PIPEHANDLE pipe;
#endif /* CONFIG_CTRL_IFACE_NAMED_PIPE */
};
```
在以上的结构体定义里我们可以看到一共定义了4个宏定义标明4中wpa_supplicant
- CONFIG_CTRL_IFACE_UDP
  
  使用ipv4 socket接口与client进行连接和通讯，默认使用localhost（127.0.0.1）
- CONFIG_CTRL_IFACE_UDP_IPV6
  
  使用ipv6 socket接口与client进行连接和通讯，默认使用localhost（::1）
- CONFIG_CTRL_IFACE_UNIX
  
  使用unix socket接口与client进行连接和通讯，是Linux和*BSD的默认配置，默认在linux系统使用/var/run/wpa_supplicant，在android系统使用/data/misc/wifi/sockets
- CONFIG_CTRL_IFACE_NAMED_PIPE
  
  使用Windows Named Pipe模式与client进行连接和通讯，是windows的默认配置
TCP/IP Socket 和 Unix Socket最大的区别就是unix-socket没有port，使用文件handle作为传输对象，但是只能在同物理主机内运行，相对ip-socket速度也更快，有人验证过unix-socket要比ip-socket快31%

WPA_Supplicant的控制接口

关wifi时：

# ps -A | grep wifi497 ?        00:00:04 wifi_hal_servic543 ?        00:00:00 wifi_host629 ?        00:01:58 wifi_manager_se# netstat -axp | grep wifi
unix  2      [ ACC ]     STREAM     LISTENING      2951369 25629/ohos.sample.w@25629ohos.sample.wifitest
unix  2      [ ACC ]     STREAM     LISTENING        18673 497/wifi_hal_servic/data/service/el1/public/wifi/unix_sock.sock
unix  2      [ ]         DGRAM                       18851 543/wifi_host
unix  2      [ ]         DGRAM                       18672 497/wifi_hal_servic
unix  2      [ ]         DGRAM                       19185 629/wifi_manager_se

开wifi时：

# ps -A | grep wifi497 ?        00:00:04 wifi_hal_servic543 ?        00:00:00 wifi_host629 ?        00:01:58 wifi_manager_se779 ?        00:00:01 wifi_hal_servic# netstat -axp | grep wifi
unix  2      [ ACC ]     STREAM     LISTENING      2951369 25629/ohos.sample.w@25629ohos.sample.wifitest
unix  2      [ ACC ]     STREAM     LISTENING        18673 497/wifi_hal_servic/data/service/el1/public/wifi/unix_sock.sock
unix  3      [ ]         STREAM     CONNECTED      3165678 497/wifi_hal_servic/data/service/el1/public/wifi/unix_sock.sock
unix  3      [ ]         STREAM     CONNECTED      3167635 629/wifi_manager_se
unix  2      [ ]         DGRAM                       18851 543/wifi_host
unix  2      [ ]         DGRAM                       18672 497/wifi_hal_servic
unix  3      [ ]         STREAM     CONNECTED      3167636 629/wifi_manager_se
unix  2      [ ]         DGRAM                       19185 629/wifi_manager_se
unix  3      [ ]         STREAM     CONNECTED      3167634 629/wifi_manager_se
unix  3      [ ]         STREAM     CONNECTED      3165679 497/wifi_hal_servic/data/service/el1/public/wifi/unix_sock.sock
unix  3      [ ]         STREAM     CONNECTED      3165020 629/wifi_manager_se
unix  3      [ ]         STREAM     CONNECTED      3167645 497/wifi_hal_servic/data/service/el1/public/wifi/unix_sock.sock
unix  3      [ ]         STREAM     CONNECTED      3165700 497/wifi_hal_servic/data/service/el1/public/wifi/unix_sock.sock

《简析OpenHarmony的WiFi能力》大概介绍过OpenHarmony里的WiFi架构，对应上面的命令行可以看出，wifi在后台启动了3个服务

wifi_manager_service：wifi服务层，为wifi框架层服务，对下通过wpa_hal与wpa_hal_service通信；
wifi_host：wlan启动的设备服务，对应vendor/hihope/rk3568/hdf_config/uhdf/device_info.hcs，
wifi_hal_service：wifi 硬件抽象服务，对应加载wpa_supplicant，与hdf进行交互，对上提供wpa_client.so

客户端

wpa_supplicant提供两种客户端：

wpa_cli：用于和wpa_supplicant交互；使用wpa_cli可以实现wifi的具体功能

# wpa_cli -i wlan0 scan
wpa_ctrl_request cmd: GET_COOKIE
wpa_ctrl_request cmd: IFNAME
wpa_ctrl_request cmd: SCAN
OK# wpa_cli -i wlan0 scan_result
wpa_ctrl_request cmd: GET_COOKIE
wpa_ctrl_request cmd: IFNAME
wpa_ctrl_request cmd: SCAN_RESULTS
bssid / frequency / signal level / flags / ssid / informationElements
6e:b1:58:65:63:67       5805    -39     [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS]              [7 434e2024042395052300][61 a1070000000000000000000000000000000000000000][192 019b00faff]
6c:b1:58:75:63:67       5805    -39     [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS]      TP-LINK_6365    [7 434e2024042395052300][61 a1070000000000000000000000000000000000000000][192 019b00faff]
f4:84:8d:01:69:ac       5785    -51     [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS]      Graphic [7 434e2024042395052300][61 9d050400000000000000000000000000000000000000][192 019b00faff]
f6:84:8d:21:69:ac       5785    -52     [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS]              [7 434e2024042395052300][61 9d050400000000000000000000000000000000000000][192 019b00faff]
f2:45:21:15:5e:75       5745    -60     [WPA2-PSK+SAE-CCMP][SAE-H2E][ESS]       iPhone 13 Pro Max       [7 434e202401172801172c01173001173401173801173c011740011795011b99011b9d011ba1011ba5011b][61 95050400000000000000000000000000000000000000][192 019b000000]
f8:af:05:87:7a:40       5180    -74     [WPA2-PSK-CCMP][WPS][ESS]       dist    [61 240d0400000000000000000000000000000000000000][192 012a00faff]
f8:af:05:f7:7a:40       5180    -74     [WPA2-PSK-CCMP][WPS][ESS]               [61 240d0000000000000000000000000000000000000000][192 012a00faff]
f8:af:05:87:7a:42       5180    -71     [WPA2-PSK-CCMP][WPS][ESS]               [61 240d0000000000000000000000000000000000000000][192 012a00faff]
6c:b1:58:75:63:65       2462    -40     [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS]      TP-LINK_6365    [7 434e20010d1b][61 0b070000000000000000000000000000000000000000]
6e:b1:58:65:63:65       2462    -40     [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS]              [7 434e20010d1b][61 0b070000000000000000000000000000000000000000]
f4:84:8d:01:69:aa       2437    -47     [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS]      Graphic [7 434e20010d14][61 06070000000000000000000000000000000000000000]
f6:84:8d:01:69:aa       2437    -46     [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS]              [7 434e20010d14][61 06070000000000000000000000000000000000000000]

对应的主要功能：

wpa_ctrl_open() ：连接WPAS的控制接口, 可以是WPAS的全局控制接口，也可以是为每一个无线网络接口指定的控制接口
wpa_ctrl_close() : 关闭wpa_ctrl_open()打开的连接
wpa_ctrl_request() : 通过建立的连接向WPAS发送消息
wpa_ctrl_attach() : 使用wpa_ctrl_open()建立的连接， WPAS默认不会向这些连接的client端发送event，必须显示调用wpa_ctrl_attach()，才能接收到消息
wpa_ctrl_detach() : 取消wpa_ctrl_attach()
wpa_ctrl_recv() : 接收WPAS端发来的event，必须要先在打开的连接上调用wpa_ctrl_attach()才能接收到event，当无event可读时，此调用会被block住
wpa_ctrl_pending() : 检查是否有pending的event，若有则可以调用wpa_ctrl_recv()来接收
wpa_ctrl_get_fd() : 获取同WPAS的连接中， client端的fd，获取的fd可以用于select， epoll等，但是不能直接用于收发消息，必须使用wpa_ctrl_request()和wpa_ctrl_recv（）
wpa_ctrl_cleanup() : 当使用unix socekt 进行连接时，会建立socket文件，若其carsh，则会遗留这些文件， wpa_ctrl_cleanup()用于清理这些文件

hostapd_cli：用于和hostapd交互；（当设置wlan为ap模式时候可以使用此功能）

服务端

wpa_supplicant提供两种服务端：
1. wpa_supplicant：Wi-Fi接入相关功能，对应wifi_hal_sta_interface.c启动或停止，此文件在wifi的services层，对应之前的wifi_hal_service；这也解释了为啥开wifi后会多出一个wifi_hal_service
2. hostapd：Wi-Fi热点相关功能，对应wifi_hal_ap_interface.c启动或停止，此文件在wifi的services层，对应之前的wifi_hal_service；

对应配置文件：

# ls ./system/etc/wifi/
hostapd.conf  p2p_supplicant.conf  wpa_supplicant.conf//热点配置
# cat ./system/etc/wifi/hostapd.conf
# Copyright (C) 2022 Huawei Device Co., Ltd.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.interface=wlan0
ctrl_interface=udp
ssid=testap
hw_mode=g
channel=1//点对点传输模式
# cat ./system/etc/wifi/p2p_supplicant.conf
# Copyright (C) 2022 Huawei Device Co., Ltd.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.ctrl_interface=udp
device_name=p2p_ohos
manufacturer=ohos
device_type=10-0050F204-5
config_methods=virtual_push_button physical_display keypad
p2p_listen_reg_class=81
p2p_listen_channel=1
p2p_oper_reg_class=81
p2p_oper_channel=1
p2p_go_intent=0
persistent_reconnect=1
serial_number=0123456789ABCDEF
p2p_ssid_postfix=-ohos
p2p_go_ht40=1
p2p_go_vht=1
update_config=1//默认的接入点模式
# cat ./system/etc/wifi/wpa_supplicant.conf
# Copyright (C) 2021 Huawei Device Co., Ltd.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.country=GB
ctrl_interface=udp
network={
}

此处多了个p2p的配置，其实就是wpa_supplicat启动时候使用的不同配置，也就是说wpa_supplicant可以作为接入点模式启动也可以作为p2p模式启动。