Test platform: mt2712, Android 9 0，Linux4. nine
Usage scenario:
Android car machine connects T-box, mobile phone and PC through USB cable, and then uses their network to surf the Internet.
In fact, the Android system already supports USB shared network, but the USB shared network has not been turned on in the corresponding product system. At this time, some configurations of USB network sharing need to be added to make the product support this function.
1, Code modification:
1. Add RNDIS support to the kernel
CONFIG_USB_USBNET=y CONFIG_USB_NET_DM9601=y CONFIG_USB_NET_SR9700=y CONFIG_USB_NET_SMSC75XX=y CONFIG_USB_NET_SMSC95XX=y +CONFIG_USB_NET_RNDIS_HOST=y
Specific network card name:
Path: kernel-4.9/drivers/net/usb/usbnet.c om c
usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
{
.........................................
dev->net = net;
strcpy (net->name, "usb%d");
printk("usbnet_probe usb");
memcpy (net->dev_addr, node_id, sizeof node_id);
........................................
// allow device-specific bind/init procedures
// NOTE net->name still not usable ...
if (info->bind) {
// heuristic: "usb%d" for links we know are two-host,
// else "eth%d" when there's reasonable doubt. userspace
// can rename the link if it knows better.
if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
(net->dev_addr [0] & 0x02) == 0))
strcpy (net->name, "eth%d");
/* WLAN devices should always be named "wlan%d" */
if ((dev->driver_info->flags & FLAG_WLAN) != 0)
strcpy(net->name, "wlan%d");
/* WWAN devices should always be named "wwan%d" */
if ((dev->driver_info->flags & FLAG_WWAN) != 0)
strcpy(net->name, "wwan%d");
}
}
The network card name is usbx by default. If it is Ethernet, the name is ethx. If it is WLAN, the name is WLAN X.
2.init. Two configuration services for usb0 are added in RC
Add two configuration services for usb0 to enable the framework to configure the usb0 network card (service is the core of USB network sharing)
On the MT2712 platform, the modified file is init MT2712. ab.emmc. rc
#Start dhcp for usb network allocation
service dhcpcd_usb0 /system/bin/dhcpcd -ABDKL -f/system/etc/dhcpcd/dhcpcd.conf
class main
disabled
oneshot
seclabel u:r:dhcp:s0
#Start usb network allocation ip
service iprenew_usb0 /system/bin/dhcpcd -n
class main
disabled
oneshot
seclabel u:r:dhcp:s0
3. Modify configuration in frameworks
Corresponding to the Android source code, add configuration in the frameworks (this is mainly about how to start the network and select the network)
frameworks/base/core/res/res/values/config.xml
The original is:
<string translatable="false" name="config_ethernet_iface_regex">eth\\d</string>
That is, Ethernet is supported
Amend to read:
<string translatable="false" name="config_ethernet_iface_regex">usb\\d</string>
USB shared network is supported.
It can also be modified to support Ethernet and USB shared networks at the same time, and then APP decides which network to use according to the actual situation.
<string translatable="false" name="config_ethernet_iface_regex">eth\\d|usb\\d</string>
config_ ethernet_ iface_ The calling process of regex is as follows:
Path: Frameworks / opt / net / Ethernet / Java / COM / Android / server / Ethernet / Ethernet tracker java
EthernetTracker(Context context, Handler handler) {
mHandler = handler;
// The services we use.
IBinder b = ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE);
mNMService = INetworkManagementService.Stub.asInterface(b);
Get the above settings here config_ethernet_iface_regex Value of
// Interface match regex.
mIfaceMatch = context.getResources().getString(
com.android.internal.R.string.config_ethernet_iface_regex);
// Read default Ethernet interface configuration from resources
final String[] interfaceConfigs = context.getResources().getStringArray(
com.android.internal.R.array.config_ethernet_interfaces);
for (String strConfig : interfaceConfigs) {
parseEthernetConfig(strConfig);
}
mConfigStore = new EthernetConfigStore();
NetworkCapabilities nc = createNetworkCapabilities(true /* clear default capabilities */);
mFactory = new EthernetNetworkFactory(handler, context, nc);
mFactory.register();
}
private void maybeTrackInterface(String iface) {
if (DBG) Log.i(TAG, "maybeTrackInterface " + iface);
// If we don't already track this interface, and if this interface matches
// our regex, start tracking it.
if (!iface.matches(mIfaceMatch) || mFactory.hasInterface(iface)) {
return;
}
if (mIpConfigForDefaultInterface != null) {
updateIpConfiguration(iface, mIpConfigForDefaultInterface);
mIpConfigForDefaultInterface = null;
}
addInterface(iface);
}
For Ethernet and USB shared networks, please refer to: https://blog.csdn.net/xcyansmile/article/details/109361979
2, Debug
The Android car is connected with the T-box through USB. The Android car is the Host and the T-box is the Device.
1. After USB connection, input lsusb in Android car to confirm that a new USB device is inserted.
Bus 003 Device 001: ID 1d6b:0002 Bus 001 Device 001: ID 1d6b:0002 Bus 001 Device 002: ID 2c7c:0125 Bus 004 Device 001: ID 1d6b:0003 Bus 002 Device 001: ID 1d6b:0003
Before insertion:
Bus 003 Device 001: ID 1d6b:0002 Bus 001 Device 001: ID 1d6b:0002 Bus 004 Device 001: ID 1d6b:0003 Bus 002 Device 001: ID 1d6b:0003
2. Check whether the network card generates ifconfig -a
console:/ # ifconfig -a
ip6tnl0 Link encap:UNSPEC
NOARP MTU:1452 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 TX bytes:0
p2p0 Link encap:Ethernet HWaddr 02:76:1c:60:1a:16
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 TX bytes:0
wlan0 Link encap:Ethernet HWaddr 00:76:1c:60:1a:16 Driver mtk_sdio_client
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 TX bytes:0
sit0 Link encap:IPv6-in-IPv4
NOARP MTU:1480 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 TX bytes:0
ip_vti0 Link encap:UNSPEC
NOARP MTU:1480 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 TX bytes:0
tunl0 Link encap:UNSPEC
NOARP MTU:1480 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 TX bytes:0
ip6_vti0 Link encap:UNSPEC
NOARP MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 TX bytes:0
usb0 Link encap:Ethernet HWaddr 36:28:7d:39:88:1b Driver rndis_host
inet addr:192.168.225.24 Bcast:192.168.225.255 Mask:255.255.255.0
inet6 addr: fe80::c888:d5a1:7f11:5ea0/64 Scope: Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:250 errors:0 dropped:0 overruns:0 frame:0
TX packets:333 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:72265 TX bytes:70616
eth0 Link encap:Ethernet HWaddr 00:55:7b:b5:7d:f7 Driver dwmac-mediatek
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 TX bytes:0
Interrupt:13 Base address:0x4000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope: Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:43 errors:0 dropped:0 overruns:0 frame:0
TX packets:43 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:3860 TX bytes:3860
The network card usb0 is generated here.
3. Confirm whether the networking is successful: ifconfig
console:/ # ifconfig
wlan0 Link encap:Ethernet HWaddr 00:76:1c:60:1a:16 Driver mtk_sdio_client
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 TX bytes:0
usb0 Link encap:Ethernet HWaddr 36:28:7d:39:88:1b Driver rndis_host
inet addr:192.168.225.24 Bcast:192.168.225.255 Mask:255.255.255.0
inet6 addr: fe80::c888:d5a1:7f11:5ea0/64 Scope: Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:279 errors:0 dropped:0 overruns:0 frame:0
TX packets:361 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:73769 TX bytes:74424
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope: Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:43 errors:0 dropped:0 overruns:0 frame:0
TX packets:43 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:3860 TX bytes:3860
Seeing usb0 indicates that the networking is successful, * * RX bytes:73769 TX bytes:74424 "* * indicates the amount of data received and sent.
Note: ensure that the network card name generated in the Linux kernel is consistent with the network card name used in the frameworks.
reference resources: https://blog.csdn.net/xcyansmile/article/details/109361979