我正在为Ubuntu Linux创建一个需要连接到WiFi AP的软件。 WiFi网络不是预定义的，并且可以在软件的单次运行期间多次改变（用户是订购改变的用户）。这个想法是这样的：给定一组SSID及其WPA或WEP密码短语，软件应该可以随心所欲地在网络之间切换，而无需在系统中的任何位置更改任何配置文件。
看起来，一个巨大的问题是将密码短语传递给连接。以下是我到目前为止所使用的内容：
起初我认为可以通过d-bus将密码传递给connman，但这个版本的connman和1.11似乎都没有公开任何方法。然后我发现可以将service_<SSID>.conf文件转储到/var/lib/connman/目录。该文件的内容非常简单，如下所示：
[service_SSID]
Type=wifi
Name=Network-SSID
Passphrase=here-goes-the-passphrase
创建此文件后，连接到网络需要在适当的服务中简单调用net.connman.Service.Connect（）方法。问题是connman不会解析配置文件，除非它重新启动。这需要sudo特权，额外的时间，并且会增加所有“现在可能出错的事情”发生的风险。然后我认为密码可以以某种方式传递给wpa_supplicant d-bus API，但我找不到任何东西。
Google搜索也让我失望了。就好像以前没有人试图这样做过。
命令sudo iwconfig wlan0 essid <SSID> key s:<PASSPHRASE>会导致SET failed on device wlan0 ; Invalid argument.错误。此外，它需要sudo，我想避免。
我试图找出wpa_gui程序如何发挥其魔力。首先，我发现它还需要sudo，并且它会将一堆命令直接发送到/var/run/wpa_supplicant/wlan0。如果我没有弄清楚任何简单的事情，复制这种行为对我来说将是最后的手段。
所以，最大的问题是：如何使用Python连接到受WEP / WPA保护的WiFi网络？
我也想知道在这里使用connman是否是一个好方法，如果我不应该恢复到网络管理器，这是Ubuntu的默认设置。
答案 0 :(得分：5)
这显示了如何为WPA执行此操作。
首先，沟渠connman并使用NetworkManager。下面的示例脚本显示了如何启用无线支持，检查具有给定SSID的网络是否可用，使用WPA密码连接到该SSID，然后断开与网络的连接并禁用无线。我很确定这个脚本可以改进，但是当前版本足以作为一个例子：
#!/usr/bin/python
# This script shows how to connect to a WPA protected WiFi network
# by communicating through D-Bus to NetworkManager 0.9.
#
# Reference URLs:
# http://projects.gnome.org/NetworkManager/developers/
# http://projects.gnome.org/NetworkManager/developers/settings-spec-08.html
import dbus
import time
SEEKED_SSID = "skynet"
SEEKED_PASSPHRASE = "qwertyuiop"
if __name__ == "__main__":
bus = dbus.SystemBus()
# Obtain handles to manager objects.
manager_bus_object = bus.get_object("org.freedesktop.NetworkManager",
"/org/freedesktop/NetworkManager")
manager = dbus.Interface(manager_bus_object,
"org.freedesktop.NetworkManager")
manager_props = dbus.Interface(manager_bus_object,
"org.freedesktop.DBus.Properties")
# Enable Wireless. If Wireless is already enabled, this does nothing.
was_wifi_enabled = manager_props.Get("org.freedesktop.NetworkManager",
"WirelessEnabled")
if not was_wifi_enabled:
print "Enabling WiFi and sleeping for 10 seconds ..."
manager_props.Set("org.freedesktop.NetworkManager", "WirelessEnabled",
True)
# Give the WiFi adapter some time to scan for APs. This is absolutely
# the wrong way to do it, and the program should listen for
# AccessPointAdded() signals, but it will do.
time.sleep(10)
# Get path to the 'wlan0' device. If you're uncertain whether your WiFi
# device is wlan0 or something else, you may utilize manager.GetDevices()
# method to obtain a list of all devices, and then iterate over these
# devices to check if DeviceType property equals NM_DEVICE_TYPE_WIFI (2).
device_path = manager.GetDeviceByIpIface("wlan0")
print "wlan0 path: ", device_path
# Connect to the device's Wireless interface and obtain list of access
# points.
device = dbus.Interface(bus.get_object("org.freedesktop.NetworkManager",
device_path),
"org.freedesktop.NetworkManager.Device.Wireless")
accesspoints_paths_list = device.GetAccessPoints()
# Identify our access point. We do this by comparing our desired SSID
# to the SSID reported by the AP.
our_ap_path = None
for ap_path in accesspoints_paths_list:
ap_props = dbus.Interface(
bus.get_object("org.freedesktop.NetworkManager", ap_path),
"org.freedesktop.DBus.Properties")
ap_ssid = ap_props.Get("org.freedesktop.NetworkManager.AccessPoint",
"Ssid")
# Returned SSID is a list of ASCII values. Let's convert it to a proper
# string.
str_ap_ssid = "".join(chr(i) for i in ap_ssid)
print ap_path, ": SSID =", str_ap_ssid
if str_ap_ssid == SEEKED_SSID:
our_ap_path = ap_path
break
if not our_ap_path:
print "AP not found :("
exit(2)
print "Our AP: ", our_ap_path
# At this point we have all the data we need. Let's prepare our connection
# parameters so that we can tell the NetworkManager what is the passphrase.
connection_params = {
"802-11-wireless": {
"security": "802-11-wireless-security",
},
"802-11-wireless-security": {
"key-mgmt": "wpa-psk",
"psk": SEEKED_PASSPHRASE
},
}
# Establish the connection.
settings_path, connection_path = manager.AddAndActivateConnection(
connection_params, device_path, our_ap_path)
print "settings_path =", settings_path
print "connection_path =", connection_path
# Wait until connection is established. This may take a few seconds.
NM_ACTIVE_CONNECTION_STATE_ACTIVATED = 2
print """Waiting for connection to reach """ \
"""NM_ACTIVE_CONNECTION_STATE_ACTIVATED state ..."""
connection_props = dbus.Interface(
bus.get_object("org.freedesktop.NetworkManager", connection_path),
"org.freedesktop.DBus.Properties")
state = 0
while True:
# Loop forever until desired state is detected.
#
# A timeout should be implemented here, otherwise the program will
# get stuck if connection fails.
#
# IF PASSWORD IS BAD, NETWORK MANAGER WILL DISPLAY A QUERY DIALOG!
# This is something that should be avoided, but I don't know how, yet.
#
# Also, if connection is disconnected at this point, the Get()
# method will raise an org.freedesktop.DBus.Error.UnknownMethod
# exception. This should also be anticipated.
state = connection_props.Get(
"org.freedesktop.NetworkManager.Connection.Active", "State")
if state == NM_ACTIVE_CONNECTION_STATE_ACTIVATED:
break
time.sleep(0.001)
print "Connection established!"
#
# Connection is established. Do whatever is necessary.
# ...
#
print "Sleeping for 5 seconds ..."
time.sleep(5)
print "Disconnecting ..."
# Clean up: disconnect and delete connection settings. If program crashes
# before this point is reached then connection settings will be stored
# forever.
# Some pre-init cleanup feature should be devised to deal with this problem,
# but this is an issue for another topic.
manager.DeactivateConnection(connection_path)
settings = dbus.Interface(
bus.get_object("org.freedesktop.NetworkManager", settings_path),
"org.freedesktop.NetworkManager.Settings.Connection")
settings.Delete()
# Disable Wireless (optional step)
if not was_wifi_enabled:
manager_props.Set("org.freedesktop.NetworkManager", "WirelessEnabled",
False)
print "DONE!"
exit(0)