From: Erfan Abdi <erfangplus@gmail.com>
Date: Sun, 13 Jun 2021 08:34:30 +0000 (+0430)
Subject: anbox: Import lxc-net script
X-Git-Url: https://glassweightruler.freedombox.rocks/gitweb/waydroid.git/commitdiff_plain/f46d9f8a8f1c2857c9802f3c2bef6354243dc6ea?ds=sidebyside

anbox: Import lxc-net script

* From: https://github.com/lxc/lxc/blob/7f4386f096a998bc96d29687f1b5303ffc1380b4/config/init/common/lxc-net.in
---

diff --git a/scripts/anbox-net.sh b/scripts/anbox-net.sh
new file mode 100644
index 0000000..b2226f3
--- /dev/null
+++ b/scripts/anbox-net.sh
@@ -0,0 +1,266 @@
+#!/bin/sh -
+
+distrosysconfdir="@LXC_DISTRO_SYSCONF@"
+varrun="@RUNTIME_PATH@/lxc"
+varlib="@LOCALSTATEDIR@/lib"
+
+# These can be overridden in @LXC_DISTRO_SYSCONF@/lxc
+#   or in @LXC_DISTRO_SYSCONF@/lxc-net
+
+USE_LXC_BRIDGE="true"
+LXC_BRIDGE="lxcbr0"
+LXC_BRIDGE_MAC="00:16:3e:00:00:00"
+LXC_ADDR="10.0.3.1"
+LXC_NETMASK="255.255.255.0"
+LXC_NETWORK="10.0.3.0/24"
+LXC_DHCP_RANGE="10.0.3.2,10.0.3.254"
+LXC_DHCP_MAX="253"
+LXC_DHCP_CONFILE=""
+LXC_DHCP_PING="true"
+LXC_DOMAIN=""
+LXC_USE_NFT="true"
+
+LXC_IPV6_ADDR=""
+LXC_IPV6_MASK=""
+LXC_IPV6_NETWORK=""
+LXC_IPV6_NAT="false"
+
+[ ! -f $distrosysconfdir/lxc ] || . $distrosysconfdir/lxc
+
+use_nft() {
+    [ -n "$NFT" ] && nft list ruleset > /dev/null 2>&1 && [ "$LXC_USE_NFT" = "true" ]
+}
+
+NFT="$(which nft)"
+if ! use_nft; then
+    use_iptables_lock="-w"
+    iptables -w -L -n > /dev/null 2>&1 || use_iptables_lock=""
+fi
+
+_netmask2cidr ()
+{
+    # Assumes there's no "255." after a non-255 byte in the mask
+    local x=${1##*255.}
+    set -- 0^^^128^192^224^240^248^252^254^ $(( (${#1} - ${#x})*2 )) ${x%%.*}
+    x=${1%%$3*}
+    echo $(( $2 + (${#x}/4) ))
+}
+
+_ifdown() {
+    ip addr flush dev ${LXC_BRIDGE}
+    ip link set dev ${LXC_BRIDGE} down
+}
+
+_ifup() {
+    MASK=`_netmask2cidr ${LXC_NETMASK}`
+    CIDR_ADDR="${LXC_ADDR}/${MASK}"
+    ip addr add ${CIDR_ADDR} broadcast + dev ${LXC_BRIDGE}
+    ip link set dev ${LXC_BRIDGE} address $LXC_BRIDGE_MAC
+    ip link set dev ${LXC_BRIDGE} up
+}
+
+start_ipv6() {
+    LXC_IPV6_ARG=""
+    if [ -n "$LXC_IPV6_ADDR" ] && [ -n "$LXC_IPV6_MASK" ] && [ -n "$LXC_IPV6_NETWORK" ]; then
+        echo 1 > /proc/sys/net/ipv6/conf/all/forwarding
+        echo 0 > /proc/sys/net/ipv6/conf/${LXC_BRIDGE}/autoconf
+        ip -6 addr add dev ${LXC_BRIDGE} ${LXC_IPV6_ADDR}/${LXC_IPV6_MASK}
+        LXC_IPV6_ARG="--dhcp-range=${LXC_IPV6_ADDR},ra-only --listen-address ${LXC_IPV6_ADDR}"
+    fi
+}
+
+start_iptables() {
+    start_ipv6
+    if [ -n "$LXC_IPV6_ARG" ] && [ "$LXC_IPV6_NAT" = "true" ]; then
+        ip6tables $use_iptables_lock -t nat -A POSTROUTING -s ${LXC_IPV6_NETWORK} ! -d ${LXC_IPV6_NETWORK} -j MASQUERADE
+    fi
+    iptables $use_iptables_lock -I INPUT -i ${LXC_BRIDGE} -p udp --dport 67 -j ACCEPT
+    iptables $use_iptables_lock -I INPUT -i ${LXC_BRIDGE} -p tcp --dport 67 -j ACCEPT
+    iptables $use_iptables_lock -I INPUT -i ${LXC_BRIDGE} -p udp --dport 53 -j ACCEPT
+    iptables $use_iptables_lock -I INPUT -i ${LXC_BRIDGE} -p tcp --dport 53 -j ACCEPT
+    iptables $use_iptables_lock -I FORWARD -i ${LXC_BRIDGE} -j ACCEPT
+    iptables $use_iptables_lock -I FORWARD -o ${LXC_BRIDGE} -j ACCEPT
+    iptables $use_iptables_lock -t nat -A POSTROUTING -s ${LXC_NETWORK} ! -d ${LXC_NETWORK} -j MASQUERADE
+    iptables $use_iptables_lock -t mangle -A POSTROUTING -o ${LXC_BRIDGE} -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill
+}
+
+start_nftables() {
+    start_ipv6
+    NFT_RULESET=""
+    if [ -n "$LXC_IPV6_ARG" ] && [ "$LXC_IPV6_NAT" = "true" ]; then
+        NFT_RULESET="${NFT_RULESET}
+add table ip6 lxc;
+flush table ip6 lxc;
+add chain ip6 lxc postrouting { type nat hook postrouting priority 100; };
+add rule ip6 lxc postrouting ip saddr ${LXC_IPV6_NETWORK} ip daddr != ${LXC_IPV6_NETWORK} counter masquerade;
+"
+    fi
+    NFT_RULESET="${NFT_RULESET};
+add table inet lxc;
+flush table inet lxc;
+add chain inet lxc input { type filter hook input priority 0; };
+add rule inet lxc input iifname ${LXC_BRIDGE} udp dport { 53, 67 } accept;
+add rule inet lxc input iifname ${LXC_BRIDGE} tcp dport { 53, 67 } accept;
+add chain inet lxc forward { type filter hook forward priority 0; };
+add rule inet lxc forward iifname ${LXC_BRIDGE} accept;
+add rule inet lxc forward oifname ${LXC_BRIDGE} accept;
+add table ip lxc;
+flush table ip lxc;
+add chain ip lxc postrouting { type nat hook postrouting priority 100; };
+add rule ip lxc postrouting ip saddr ${LXC_NETWORK} ip daddr != ${LXC_NETWORK} counter masquerade"
+    nft "${NFT_RULESET}"
+}
+
+start() {
+    [ "x$USE_LXC_BRIDGE" = "xtrue" ] || { exit 0; }
+
+    [ ! -f "${varrun}/network_up" ] || { echo "lxc-net is already running"; exit 1; }
+
+    if [ -d /sys/class/net/${LXC_BRIDGE} ]; then
+        stop force || true
+    fi
+
+    FAILED=1
+
+    cleanup() {
+        set +e
+        if [ "$FAILED" = "1" ]; then
+            echo "Failed to setup lxc-net." >&2
+            stop force
+            exit 1
+        fi
+    }
+
+    trap cleanup EXIT HUP INT TERM
+    set -e
+
+    # set up the lxc network
+    [ ! -d /sys/class/net/${LXC_BRIDGE} ] && ip link add dev ${LXC_BRIDGE} type bridge
+    echo 1 > /proc/sys/net/ipv4/ip_forward
+    echo 0 > /proc/sys/net/ipv6/conf/${LXC_BRIDGE}/accept_dad || true
+
+    # if we are run from systemd on a system with selinux enabled,
+    # the mkdir will create /run/lxc as init_var_run_t which dnsmasq
+    # can't write its pid into, so we restorecon it (to var_run_t)
+    if [ ! -d "${varrun}" ]; then
+        mkdir -p "${varrun}"
+        if which restorecon >/dev/null 2>&1; then
+            restorecon "${varrun}"
+        fi
+    fi
+
+    _ifup
+
+    if use_nft; then
+        start_nftables
+    else
+        start_iptables
+    fi
+
+    LXC_DOMAIN_ARG=""
+    if [ -n "$LXC_DOMAIN" ]; then
+        LXC_DOMAIN_ARG="-s $LXC_DOMAIN -S /$LXC_DOMAIN/"
+    fi
+
+    # lxc's dnsmasq should be hermetic and not read `/etc/dnsmasq.conf` (which
+    # it does by default if `--conf-file` is not present
+    LXC_DHCP_CONFILE_ARG="--conf-file=${LXC_DHCP_CONFILE:-/dev/null}"
+
+    # https://lists.linuxcontainers.org/pipermail/lxc-devel/2014-October/010561.html
+    for DNSMASQ_USER in lxc-dnsmasq dnsmasq nobody
+    do
+        if getent passwd ${DNSMASQ_USER} >/dev/null; then
+            break
+        fi
+    done
+
+    LXC_DHCP_PING_ARG=""
+    if [ "x$LXC_DHCP_PING" = "xfalse" ]; then
+        LXC_DHCP_PING_ARG="--no-ping"
+    fi
+
+    dnsmasq $LXC_DHCP_CONFILE_ARG $LXC_DOMAIN_ARG $LXC_DHCP_PING_ARG -u ${DNSMASQ_USER} \
+            --strict-order --bind-interfaces --pid-file="${varrun}"/dnsmasq.pid \
+            --listen-address ${LXC_ADDR} --dhcp-range ${LXC_DHCP_RANGE} \
+            --dhcp-lease-max=${LXC_DHCP_MAX} --dhcp-no-override \
+            --except-interface=lo --interface=${LXC_BRIDGE} \
+            --dhcp-leasefile="${varlib}"/misc/dnsmasq.${LXC_BRIDGE}.leases \
+            --dhcp-authoritative $LXC_IPV6_ARG || cleanup
+
+    touch "${varrun}"/network_up
+    FAILED=0
+}
+
+stop_iptables() {
+    iptables $use_iptables_lock -D INPUT -i ${LXC_BRIDGE} -p udp --dport 67 -j ACCEPT
+    iptables $use_iptables_lock -D INPUT -i ${LXC_BRIDGE} -p tcp --dport 67 -j ACCEPT
+    iptables $use_iptables_lock -D INPUT -i ${LXC_BRIDGE} -p udp --dport 53 -j ACCEPT
+    iptables $use_iptables_lock -D INPUT -i ${LXC_BRIDGE} -p tcp --dport 53 -j ACCEPT
+    iptables $use_iptables_lock -D FORWARD -i ${LXC_BRIDGE} -j ACCEPT
+    iptables $use_iptables_lock -D FORWARD -o ${LXC_BRIDGE} -j ACCEPT
+    iptables $use_iptables_lock -t nat -D POSTROUTING -s ${LXC_NETWORK} ! -d ${LXC_NETWORK} -j MASQUERADE
+    iptables $use_iptables_lock -t mangle -D POSTROUTING -o ${LXC_BRIDGE} -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill
+    if [ "$LXC_IPV6_NAT" = "true" ]; then
+        ip6tables $use_iptables_lock -t nat -D POSTROUTING -s ${LXC_IPV6_NETWORK} ! -d ${LXC_IPV6_NETWORK} -j MASQUERADE
+    fi
+}
+
+stop_nftables() {
+    # Adding table before removing them is just to avoid
+    # delete error for non-existent table
+    NFT_RULESET="add table inet lxc;
+delete table inet lxc;
+add table ip lxc;
+delete table ip lxc;
+"
+    if [ "$LXC_IPV6_NAT" = "true" ]; then
+        NFT_RULESET="${NFT_RULESET};
+add table ip6 lxc;
+delete table ip6 lxc;"
+    fi
+    nft "${NFT_RULESET}"
+}
+
+stop() {
+    [ "x$USE_LXC_BRIDGE" = "xtrue" ] || { exit 0; }
+
+    [ -f "${varrun}/network_up" ] || [ "$1" = "force" ] || { echo "lxc-net isn't running"; exit 1; }
+
+    if [ -d /sys/class/net/${LXC_BRIDGE} ]; then
+        _ifdown
+        if use_nft; then
+            stop_nftables
+        else
+            stop_iptables
+        fi
+
+        pid=`cat "${varrun}"/dnsmasq.pid 2>/dev/null` && kill -9 $pid
+        rm -f "${varrun}"/dnsmasq.pid
+        # if $LXC_BRIDGE has attached interfaces, don't destroy the bridge
+        ls /sys/class/net/${LXC_BRIDGE}/brif/* > /dev/null 2>&1 || ip link delete ${LXC_BRIDGE}
+    fi
+
+    rm -f "${varrun}"/network_up
+}
+
+# See how we were called.
+case "$1" in
+    start)
+        start
+    ;;
+
+    stop)
+        stop
+    ;;
+
+    restart|reload|force-reload)
+        $0 stop
+        $0 start
+    ;;
+
+    *)
+        echo "Usage: $0 {start|stop|restart|reload|force-reload}"
+        exit 2
+esac
+
+exit $?