path: root/autoDHCP.py

#!/bin/env python

import sys
import ipaddress
import argparse
import os
from os.path import exists
import subprocess
import tempfile


def guess_wifi() -> list[str]:
    return [interface for interface in os.listdir('/sys/class/net/') if
            exists(f'/sys/class/net/{interface}/wireless')]


def guess_nowifi() -> list[str]:
    return [interface for interface in os.listdir('/sys/class/net/') if
            not exists(f'/sys/class/net/{interface}/wireless')]


def guess_interface() -> list[str]:
    return [interface for interface in os.listdir('/sys/class/net/')]


def guess_internet() -> list[str]:
    com = subprocess.Popen(['ip', 'route', 'show'], stdout=subprocess.PIPE,
                           stderr=subprocess.STDOUT)
    stdout, stderr = com.communicate()
    if stderr:
        return []
    print(str(stdout).split('\n'))

    internet_i = [line for line in
                  [stripedLine(line) for line in str(stdout).split('\n') if
                   'default' in line]
                  if line != '']

    return list(set(internet_i))


def stripedLine(line) -> str:
    words = line.split(' ')
    if 'dev' in words and words.index('dev'):
        return words[words.index('dev') + 1]
    else:
        return ''


def menu(listEntry, strInput, refresh=None) -> int:
    if listEntry == []:
        print(f"Error menu: Empty list\n({strInput})", file=sys.stderr)
        sys.exit(1)

    c = -1
    if len(listEntry) == 1:
        c = 0
    while not (0 < c <= len(listEntry)):
        for i, ii in enumerate(listEntry):
            print(f" {i + 1}) {ii}")
        r = input(f'{strInput} '
                  f'(q to quit{ ", r to refresh" if refresh else ""}) :')
        if refresh and r == 'r':
            listEntry = refresh()
        elif r.lower() in ['q', 'quit']:
            exit(0)
        else:
            try:
                c = int(r)
            except:
                pass
    return c - 1


ip = '10.5.6.11'
netRange = '24'
ssid = '🦖'
password = 'chocoball'

hostapd_conf = '''
interface={interface}
ssid={ssid}
wpa_passphrase={passphrase}
wpa=1

channel=11
hw_mode=g

# ieee80211d=1
# country_code=FR
ieee80211n=1
# ieee80211ac=1

logger_syslog=-1
logger_syslog_level=2
logger_stdout=-1
logger_stdout_level=2

ctrl_interface=/var/run/hostapd
ctrl_interface_group=0

beacon_int=100
dtim_period=2
max_num_sta=255
rts_threshold=2347
fragm_threshold=2346
macaddr_acl=0
auth_algs=3
ignore_broadcast_ssid=0

wmm_enabled=1
wmm_ac_bk_cwmin=4
wmm_ac_bk_cwmax=10
wmm_ac_bk_aifs=7
wmm_ac_bk_txop_limit=0
wmm_ac_bk_acm=0
wmm_ac_be_aifs=3
wmm_ac_be_cwmin=4
wmm_ac_be_cwmax=10
wmm_ac_be_txop_limit=0
wmm_ac_be_acm=0
wmm_ac_vi_aifs=2
wmm_ac_vi_cwmin=3
wmm_ac_vi_cwmax=4
wmm_ac_vi_txop_limit=94
wmm_ac_vi_acm=0
wmm_ac_vo_aifs=2
wmm_ac_vo_cwmin=2
wmm_ac_vo_cwmax=3
wmm_ac_vo_txop_limit=47
wmm_ac_vo_acm=0

wpa_key_mgmt=WPA-PSK
rsn_pairwise=CCMP
wpa=2

vht_oper_chwidth=3
eap_message=hello
eapol_key_index_workaround=0
eap_server=0
'''

dnsmasq_conf = '''
interface={interface}
listen-address={ip}
dhcp-range={dhcp_range}
'''

# dhcp_range=$(echo ${ip_start}{$ip_start_tmp\,,254}),12h

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Automaticaly set up a DHCP server')
    parser.add_argument('--ip', dest='ip', default=ip, help='IP on the DHCP network')
    parser.add_argument('-r', '--range', dest='range', default=netRange,
                        help='number of bit of the IP that are part of the '
                        'network address')
    parser.add_argument('-s', '--ssid', dest='ssid', default=ssid, help='Wifi\'s "name"')
    parser.add_argument('--password', dest='passwd', default=password,
                        help='the password of the Wifi network if any')
    parser.add_argument('--no-password', dest='nopass', action='store_true',
                        help='disable password')
    parser.add_argument('-t', '--tethering', dest='teth', action='store_true',
                        help='configure tethering on the DHCP network')
    parser.add_argument('-w', '--wifi', dest='wifi', action='store_true',
                        help='DHCP on a wifi interface')
    parser.add_argument('--no-wifi', dest='nowifi', action='store_true',
                        help='DHCP not on a wifi interface')
    parser.add_argument('-in', '--inet-iface', dest='internet_interface',
                        help='the internet interface to use when tethering')
    parser.add_argument('-i', '--iface', dest='interface',
                        help='DHCP network\'s interface')

    arg = parser.parse_args()

    if arg.wifi and arg.nowifi:
        print('Wifi or not Wifi, that is the question', file=sys.stderr)
        exit(1)
    ip = ipaddress.ip_address(arg.ip)

    inetInt = arg.internet_interface
    netInt = arg.interface

    if arg.teth:
        if not arg.internet_interface:
            inet_int = guess_internet()
            i = menu(inet_int, "Select the internet network interface", refresh=guess_internet)
            inetInt = inet_int[i]

    interfaces_list = []
    refresh = None

    if arg.wifi:
        refresh = guess_wifi
    elif arg.nowifi:
        refresh = guess_nowifi
    else:
        refresh = guess_interface

    interfaces_list = refresh()

    if not netInt:
        c = menu(interfaces_list, "Select the DHCP network's interface", refresh)
        netInt = interfaces_list[c]
    else:
        if netInt not in interfaces_list:
            if arg.wifi:
                print(f"{netInt} not a valid wifi interface", file=sys.stderr)
                exit(2)
            elif arg.nowifi:
                if netInt in guess_interface():
                    print(f'Warning: {netInt} is a wifi interface')
                else:
                    print(f"{netInt} not a valid interface", file=sys.stderr)
                    exit(2)
            else:
                print(f"{netInt} not a valid interface", file=sys.stderr)
                exit(2)

    os.system(f'ip link set {netInt} up')
    os.system(f'ip addr add {ip}/{netRange} dev {netInt}')

    fd, dnsConfPath = tempfile.mkstemp(dir="/tmp/")
    f_, pidPath = tempfile.mkstemp(dir="/tmp/")
    os.close(f_)

    with os.fdopen(fd, 'w') as tmp:
        network = ipaddress.ip_network(f'{ip}/{netRange}', strict=False)
        nextIp = ipaddress.ip_address(int(ip) + 1)
        lastIp = ipaddress.ip_address(int(network.broadcast_address) - 1)

        if nextIp >= lastIp:
            print('Error: Empty DHCP range', file=sys.stderr)
            exit(3)

        dhcp_range = f'{nextIp}, {lastIp}, 12h'
        tmp.write(dnsmasq_conf.format(interface=netInt, ip=ip,
                                      dhcp_range=dhcp_range))

    print("🔧 - Setting up dns server", f"Range : {dhcp_range}",
            f"Server IP: {ip}", sep='\n')
    ret = os.system(f'dnsmasq --conf-file={dnsConfPath} --pid-file={pidPath}')
    os.remove(dnsConfPath)
    pid = None
    with open(pidPath, "r") as f:
        pid = f.read().strip()
        os.remove(pidPath)

    if ret:
        print('Error: dnsmasq failed to launch', file=sys.stderr)
        exit(1)
    else:
        print(f'✅ dnsmasq launch with pid ({pid})')

    if arg.teth:
        os.system('sysctl net.ipv4.ip_forward=1')
        os.system('sysctl net.ipv6.conf.all.forwarding=1')
        os.system(f'iptables -t nat -A POSTROUTING -o {inetInt} -j MASQUERADE')
        os.system('iptables -A FORWARD -m conntrack --ctstate'
                  ' RELATED,ESTABLISHED -j ACCEPT')
        os.system(f'iptables -A FORWARD -i {netInt} -o {inetInt} -j ACCEPT')
        print("Tethering set")

    if arg.wifi:
        fd2, hostAPConfPath = tempfile.mkstemp(dir="/tmp/")

        with os.fdopen(fd2, 'w') as tmp:
            tmp.write(hostapd_conf.format(ssid=arg.ssid,
                                          interface=netInt,
                                          passphrase=arg.passwd))

        print("⚙️  - Setting up hostapd", f"SSID: {ssid}",
                f"Password: {arg.passwd}", f"Interface: {netInt}",
                sep='\n')
        ret = os.system(f'hostapd {hostAPConfPath}')
        if ret:
            print('Error: hostapd failed to launch', file=sys.stderr)
            if pid is not None:
                os.system(f'kill {pid}')
            exit(1)

        if pid is not None:
            print(" 🤖 - Terminating DHCP server")
            ret = os.system(f'kill {pid}')
            print("✅ Hasta la vista, baby")

    print("Thant you for using autoDHCP ! 💋 ")