platform_linux.py

import hillstone

import os
import fcntl
import struct
import subprocess

try:
    from subprocess import DEVNULL
except ImportError:
    DEVNULL = open(os.devnull, 'wb')

route_table_bak = b''
nameserver_bak = b''
tun = None

def set_network(c):
    global tun, route_table_bak, nameserver_bak
    TUNSETIFF = 0x800454ca # 0x400454ca
    TUNSETIFF_ROUTER = 0x400454ca
    IFF_TUN = 0x0001
    IFF_NO_PI = 0x1000

    tun = open('/dev/net/tun', 'r+b', buffering=0)
    ifr = struct.pack('16sH', b'', IFF_TUN | IFF_NO_PI)
    try:
        ifr = fcntl.ioctl(tun, TUNSETIFF, ifr)
    except IOError:
        ifr = fcntl.ioctl(tun, TUNSETIFF_ROUTER, ifr)
    ifr = ifr[:ifr.index(b'\0')].decode('ascii')

    subprocess.check_call('ip address add dev '+ifr+' '+str(c.ip_ipv4.ip), shell=True)
    subprocess.check_call('ip link set dev '+ifr+' up', shell=True)
    route_table_bak = subprocess.check_output('ip route save table main', shell=True)
    #server_gateway = subprocess.check_output('ip route get fibmatch '+c.server_host, shell=True)
    server_gateway = subprocess.check_output('ip route get '+c.server_host, shell=True).split(b'\n')[0]
    try:
        server_gateway = server_gateway[server_gateway.index(b' via'):]
    except ValueError:
        server_gateway = server_gateway[server_gateway.index(b' dev'):]
    subprocess.call('ip route add '+c.server_host+server_gateway.decode('ascii'), shell=True)
    subprocess.check_call('ip route add '+str(c.gateway_ipv4)+' dev '+ifr, shell=True)
    subprocess.check_call('ip route add '+str(c.ip_ipv4.network)+' via '+str(c.gateway_ipv4), shell=True)
    subprocess.check_call('ip route add 10.129.0.0/16 via '+str(c.gateway_ipv4), shell=True)
    subprocess.check_call('ip route add 172.31.0.0/16 via '+str(c.gateway_ipv4), shell=True)
    subprocess.check_call('ip route add 172.32.0.0/16 via '+str(c.gateway_ipv4), shell=True)
    # subprocess.check_call('ip route replace default metric 0 via '+str(c.gateway_ipv4), shell=True)

    with open('/etc/resolv.conf', 'rb') as f:
        nameserver_bak = f.read()
    
    # with open('/etc/resolv.conf', 'wb') as f:
    #     buf = 'nameserver ' + str(c.dns_ipv4) + '\n'
    #     f.write(buf.encode('ascii'))
    
def restore_network(c):
    from tempfile import NamedTemporaryFile
    with NamedTemporaryFile() as f:
        f.write(route_table_bak)
        f.flush()
        subprocess.check_call('ip route flush table main', shell=True)
        subprocess.check_call('ip route restore < '+f.name, shell=True, stderr=DEVNULL)
    # with open('/etc/resolv.conf', 'wb') as f:
    #     f.write(nameserver_bak)

def write(datagram):
    os.write(tun.fileno(), datagram)

def read():
    return os.read(tun.fileno(), 8192)