WiP adding Android tethering with generic instructions at https://wik…

…i.gentoo.org/wiki/Android_USB_tethering

First attempt with gadget failed https://forums.gentoo.org/viewtopic-t-1095940.html

Works with latest GrapheneOS (and expected all supported devices)

TODO:
- network-init-recovery:
  - time sync is failing against DNS address (phone doesn't provide) and talking to ntp.pool.org either
  - Prompts to for user to connect phone and instructions on how to setup phone should be given
modules/linux + board config:
- maybe ANDROID_TETHER is too generic and should be called GRAPHENEOS_TETHER instead
general:
- network-init-recovery is one size fits all.
  - Maybe put calls into functions and permit passing validating existing interfaces as arguments

Otherwise we have network when network-init-recovery is called and phone is plugged in USB tether mode

Goal of all this is to be able to download and boot TinyCore + custom package
(wyng: never forget)

boards/x230-maximized/x230-maximized.config

@@ -16,6 +16,7 @@ CONFIG_LINUX_CONFIG=config/linux-x230-maximized.config
 #Additional hardware support
 CONFIG_LINUX_USB=y
 CONFIG_LINUX_E1000E=y
+CONFIG_ANDROID_TETHERING=y
 
 CONFIG_CRYPTSETUP2=y
 CONFIG_FLASHROM=y

config/linux-x230-maximized.config

@@ -959,6 +959,7 @@ CONFIG_BLK_DEV_RAM_SIZE=65536
 #
 # CONFIG_BLK_DEV_NVME is not set
 # CONFIG_NVME_FC is not set
+# CONFIG_NVME_TARGET is not set
 # end of NVME Support
 
 #
@@ -1244,7 +1245,48 @@ CONFIG_E1000E_HWTS=y
 
 # CONFIG_PPP is not set
 # CONFIG_SLIP is not set
-# CONFIG_USB_NET_DRIVERS is not set
+CONFIG_USB_NET_DRIVERS=m
+# CONFIG_USB_CATC is not set
+# CONFIG_USB_KAWETH is not set
+# CONFIG_USB_PEGASUS is not set
+# CONFIG_USB_RTL8150 is not set
+# CONFIG_USB_RTL8152 is not set
+# CONFIG_USB_LAN78XX is not set
+CONFIG_USB_USBNET=m
+# CONFIG_USB_NET_AX8817X is not set
+# CONFIG_USB_NET_AX88179_178A is not set
+CONFIG_USB_NET_CDCETHER=m
+CONFIG_USB_NET_CDC_EEM=m
+# CONFIG_USB_NET_CDC_NCM is not set
+# CONFIG_USB_NET_HUAWEI_CDC_NCM is not set
+# CONFIG_USB_NET_CDC_MBIM is not set
+# CONFIG_USB_NET_DM9601 is not set
+# CONFIG_USB_NET_SR9700 is not set
+# CONFIG_USB_NET_SR9800 is not set
+# CONFIG_USB_NET_SMSC75XX is not set
+# CONFIG_USB_NET_SMSC95XX is not set
+# CONFIG_USB_NET_GL620A is not set
+# CONFIG_USB_NET_NET1080 is not set
+# CONFIG_USB_NET_PLUSB is not set
+# CONFIG_USB_NET_MCS7830 is not set
+CONFIG_USB_NET_RNDIS_HOST=m
+CONFIG_USB_NET_CDC_SUBSET=m
+# CONFIG_USB_ALI_M5632 is not set
+# CONFIG_USB_AN2720 is not set
+# CONFIG_USB_BELKIN is not set
+# CONFIG_USB_ARMLINUX is not set
+# CONFIG_USB_EPSON2888 is not set
+# CONFIG_USB_KC2190 is not set
+# CONFIG_USB_NET_ZAURUS is not set
+# CONFIG_USB_NET_CX82310_ETH is not set
+# CONFIG_USB_NET_KALMIA is not set
+# CONFIG_USB_NET_QMI_WWAN is not set
+# CONFIG_USB_NET_INT51X1 is not set
+# CONFIG_USB_IPHETH is not set
+# CONFIG_USB_SIERRA_NET is not set
+# CONFIG_USB_VL600 is not set
+# CONFIG_USB_NET_CH9200 is not set
+# CONFIG_USB_NET_AQC111 is not set
 # CONFIG_WLAN is not set
 
 #
@@ -2479,6 +2521,7 @@ CONFIG_NVMEM=y
 # CONFIG_SLIMBUS is not set
 # CONFIG_INTERCONNECT is not set
 # CONFIG_COUNTER is not set
+# CONFIG_MOST is not set
 # end of Device Drivers
 
 #
@@ -2501,6 +2544,7 @@ CONFIG_FS_MBCACHE=y
 # CONFIG_JFS_FS is not set
 # CONFIG_XFS_FS is not set
 # CONFIG_GFS2_FS is not set
+# CONFIG_OCFS2_FS is not set
 # CONFIG_BTRFS_FS is not set
 # CONFIG_NILFS2_FS is not set
 # CONFIG_F2FS_FS is not set
@@ -2627,6 +2671,7 @@ CONFIG_NLS_ISO8859_1=y
 # CONFIG_NLS_MAC_ROMANIAN is not set
 # CONFIG_NLS_MAC_TURKISH is not set
 CONFIG_NLS_UTF8=y
+# CONFIG_DLM is not set
 CONFIG_UNICODE=y
 # CONFIG_UNICODE_NORMALIZATION_SELFTEST is not set
 # end of File systems

initrd/bin/network-init-recovery

@@ -14,7 +14,24 @@ for module in `echo $network_modules`; do
 	fi
 done
 
-if [ -e /sys/class/net/eth0 ]; then
+#Tethering over Android 11+ PoC
+if [ -e /lib/modules/rndis_host.ko ]; then
+	#first enable USB controllers
+	enable_usb
+	network_modules="mii usbnet cdc_eem cdc_ether rndis_host"
+
+	for module in `echo $network_modules`; do
+        	if [ -f /lib/modules/$module.ko ]; then
+                	insmod /lib/modules/$module.ko
+        	fi
+	done
+	#other prep needed
+fi
+
+if [ -e /sys/class/net/usb0 ]; then
+	echo "Tethering on..."
+	dev=usb0
+elif [ -e /sys/class/net/eth0 ]; then
 	#Randomize eth0 MAC address of maximized boards
 	if echo "$CONFIG_BOARD" | grep -q maximized; then
 		ifconfig eth0 down
@@ -28,34 +45,36 @@ if [ -e /sys/class/net/eth0 ]; then
 	# Set up static IP
 	if [ ! -z "$CONFIG_BOOT_STATIC_IP" ]; then
 		ifconfig eth0 $CONFIG_BOOT_STATIC_IP
-	#Get ip from DHCP
-	elif [ -e /sbin/udhcpc ];then
-		if udhcpc -T 1 -q; then
-			if [ -e /sbin/ntpd ]; then
-				DNS_SERVER=$(grep nameserver /etc/resolv.conf|awk -F " " {'print $2'})
-				killall ntpd 2&>1 > /dev/null
-		 		if ! ntpd -d -N -n -q -p $DNS_SERVER > /dev/ttyprintk; then
-					if ! ntpd -d -d -N -n -q -p ntp.pool.org> /dev/ttyprintk; then
-						echo "NTP sync unsuccessful." > /dev/tty0
-					fi
+	fi
+	dev=eth0
+fi
+
+#Get ip from DHCP
+if [ -e /sbin/udhcpc ];then
+	if udhcpc -T 1 -i $dev -q; then
+		if [ -e /sbin/ntpd ]; then
+			DNS_SERVER=$(grep nameserver /etc/resolv.conf|awk -F " " {'print $2'})
+			killall ntpd 2&>1 > /dev/null
+		 	if ! ntpd -d -N -n -q -p $DNS_SERVER > /dev/ttyprintk; then
+				if ! ntpd -d -d -N -n -q -p ntp.pool.org> /dev/ttyprintk; then
+					echo "NTP sync unsuccessful." > /dev/tty0
+					#TODO: clean time sync. Not always successful
 				fi
-				hwclock -w
-				echo "" > /dev/tty0
-				date=`date "+%Y-%m-%d %H:%M:%S %Z"`
-				echo "Time: $date" > /dev/tty0
 			fi
-		fi		 
-	fi
-
-	ifconfig eth0 > /dev/ttyprintk
-
-	if [ -e /bin/dropbear ]; then
-		# Set up the ssh server, allow root logins and log to stderr
-		if [ ! -d /etc/dropbear ]; then
-			mkdir /etc/dropbear
+			hwclock -w
+			echo "" > /dev/tty0
+			date=`date "+%Y-%m-%d %H:%M:%S %Z"`
+			echo "Time: $date" > /dev/tty0
 		fi
-		dropbear -B -R 2>/dev/ttyprintk
+	fi		 
+fi
+
+if [ -e /bin/dropbear ]; then
+	# Set up the ssh server, allow root logins and log to stderr
+	if [ ! -d /etc/dropbear ]; then
+		mkdir /etc/dropbear
 	fi
-	echo  "" > /dev/tty0
-	ifconfig eth0 | head -2 > /dev/tty0
+	dropbear -B -R 2>/dev/ttyprintk
 fi
+echo  "" > /dev/tty0
+ifconfig > /dev/tty0

modules/linux

@@ -121,6 +121,24 @@ linux_modules-$(CONFIG_LINUX_USB)	+= drivers/usb/storage/usb-storage.ko
 #USB modules when a USB keyboard is defined in board config
 linux_modules-$(CONFIG_USB_KEYBOARD)	+= drivers/hid/usbhid/usbhid.ko
 
+#USB modules for Android USB Internet Tethering
+#Non working https://forums.gentoo.org/viewtopic-t-1095940.html
+#linux_modules-$(CONFIG_ANDROID_TETHERING)	+= drivers/usb/gadget/udc/udc-core.ko
+#linux_modules-$(CONFIG_ANDROID_TETHERING)       += drivers/usb/gadget/function/usb_f_ecm.ko
+#linux_modules-$(CONFIG_ANDROID_TETHERING)       += drivers/usb/gadget/function/u_ether.ko 
+#linux_modules-$(CONFIG_ANDROID_TETHERING)       += drivers/usb/gadget/function/usb_f_ecm_subset.ko 
+#linux_modules-$(CONFIG_ANDROID_TETHERING)       += drivers/usb/gadget/function/usb_f_eem.ko
+#linux_modules-$(CONFIG_ANDROID_TETHERING)       += drivers/usb/gadget/function/usb_f_rndis.ko
+#linux_modules-$(CONFIG_ANDROID_TETHERING)       += drivers/usb/gadget/legacy/g_ether.ko
+#linux_modules-$(CONFIG_ANDROID_TETHERING)       += drivers/usb/gadget/libcomposite.ko
+#linux_modules-$(CONFIG_ANDROID_TETHERING)       += fs/configfs/configfs.ko
+#Testing https://wiki.gentoo.org/wiki/Android_USB_tethering general instructions:
+linux_modules-$(CONFIG_ANDROID_TETHERING)	+= drivers/net/usb/cdc_eem.ko
+linux_modules-$(CONFIG_ANDROID_TETHERING)       += drivers/net/usb/rndis_host.ko
+linux_modules-$(CONFIG_ANDROID_TETHERING)       += drivers/net/usb/cdc_ether.ko
+linux_modules-$(CONFIG_ANDROID_TETHERING)       += drivers/net/usb/usbnet.ko
+linux_modules-$(CONFIG_ANDROID_TETHERING)       += drivers/net/mii.ko
+
 # NVMe driver for winterfell and other servers
 linux_modules-$(CONFIG_LINUX_NVME)	+= drivers/nvme/host/nvme.ko
 linux_modules-$(CONFIG_LINUX_NVME)	+= drivers/nvme/host/nvme-core.ko