iankelling.org Git - distro-setup/blob - trusted-network

   1 #!/bin/bash
   2
   3 # Usage: run to trust or untrust dns. public wifi sometimes needs to
   4 # trust dns initially to log in.
   5
   6
   7 [[ $EUID == 0 ]] || exec sudo -E "${BASH_SOURCE[0]}" "$@"
   8
   9 source /a/bin/errhandle/err
  10
  11 readonly this_file=$(readlink -f -- "${BASH_SOURCE[0]}")
  12 readonly this_dir="${this_file%/*}"
  13 script_name="${BASH_SOURCE[0]}"
  14 script_name="${script_name##*/}"
  15
  16 # removes malware and adult content
  17 servers=(1.1.1.3 1.0.0.3 2606:4700:4700::1113 2606:4700:4700::1003)
  18
  19 servers=(1.1.1.1 1.0.0.1 2606:4700:4700::1111 2606:4700:4700::1001)
  20
  21 ## trying out google
  22 servers=(8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844)
  23
  24
  25
  26 m() { printf "%s\n" "$*";  "$@"; }
  27 e() { printf "%s\n" "$@"; }
  28 i() { # install file
  29   local tmp tmpdir dest="$1"
  30   local base="${dest##*/}"
  31   mkdir -p ${dest%/*}
  32   ir=false # i result
  33   tmpdir=$(mktemp -d)
  34   cat >$tmpdir/"$base"
  35   tmp=$(rsync -ic $tmpdir/"$base" "$dest")
  36   if [[ $tmp ]]; then
  37     printf "%s\n" "$tmp"
  38     ir=true
  39   fi
  40   rm -rf $tmpdir
  41 }
  42
  43 e $script_name
  44 exit 0
  45
  46 # i symlinked the script to another name to make it work different
  47 trust=true
  48 case $script_name in
  49   untrusted-network)
  50     trust=false
  51     ;;
  52 esac
  53
  54
  55 if $trust; then
  56   if [[ -e /etc/NetworkManager/conf.d/dns.conf ]]; then
  57     rm -fv /etc/NetworkManager/conf.d/dns.conf
  58     if [[ $(systemctl is-active NetworkManager) == active ]]; then
  59       m systemctl restart NetworkManager
  60     fi
  61   fi
  62
  63   rm -fv /etc/systemd/resolved.conf.d/untrusted-network.conf
  64 else  #untrusted
  65   # https://wiki.archlinux.org/index.php/Systemd-resolved#Manually
  66   cat >/etc/systemd/resolved.conf.d/untrusted-network.conf <<EOF
  67 [Resolve]
  68 DNS=${servers[@]}
  69 Domains=b8.nz
  70 DNSOverTLS=yes
  71 EOF
  72
  73   i /etc/NetworkManager/conf.d/dns.conf <<'EOF'
  74 [main]
  75 dns=none
  76 systemd-resolved=false
  77 EOF
  78
  79   if $ir && [[ $(systemctl is-active NetworkManager) == active ]]; then
  80     m systemctl restart NetworkManager
  81   fi
  82 fi
  83
  84 dhclient_restart=false
  85 # man dhclient.conf
  86 if ! grep -qP '\bdomain-name-servers\b' /etc/dhcp/dhclient.conf; then
  87   sed -i 's/^ *request/request domain-name-servers,/' /etc/dhcp/dhclient.conf
  88   dhclient_restart=true
  89   e $0: dhclient_restart=true
  90 fi
  91
  92
  93 # wait for networkmanager to come back
  94 for f in {1..20}; do
  95   if read -r _ _ _ _  gateway_if _ < <(ip route get 8.8.8.8); then
  96     break
  97   fi
  98   m sleep 2
  99 done
 100
 101
 102 if [[ $gateway_if ]]; then
 103   # we could do this, but dhclient is still running and will use its old settings
 104   # from dependencies of ifupdown,
 105   # from man dhclient-script
 106   # from /etc/dhcp/dhclient-enter-hooks.d/resolved
 107   # rm -f /run/systemd/resolved.conf.d/*$gateway_if*
 108
 109
 110   if $dhclient_restart && grep -Pq "^ *auto ($gateway_if|.* $gateway_if( |$))" /etc/network/interfaces; then
 111     m ifdown $gateway_if
 112     m ifup $gateway_if
 113   fi
 114
 115   # at least on systemd 237 ifupdown it sets a global and this is not needed
 116   systemd-resolve --interface=$gateway_if --revert
 117 else
 118   e $0: no gateway_if found
 119 fi
 120
 121 m systemctl restart systemd-resolved
 122
 123
 124
 125 # just for curiosity i did a
 126 # wrapper around dhclient, then ifdown eth0; ifup eth0:
 127
 128 # Tue Mar  9 18:29:05 EST 2021
 129 # args -4 -v -r -pf /run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases -I -df /var/lib/dhcp/dhclient6.eth0.leases eth0
 130 # env
 131 # ADDRFAM=inet
 132 # PHASE=pre-down
 133 # VERBOSITY=0
 134 # PWD=/sbin
 135 # IFACE=eth0
 136 # METHOD=dhcp
 137 # SHLVL=1
 138 # LOGICAL=eth0
 139 # MODE=stop
 140 # PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
 141 # IFUPDOWN_eth0=pre-down
 142 # _=/usr/bin/env
 143 # Tue Mar  9 18:29:07 EST 2021
 144 # args -1 -4 -v -pf /run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases -I -df /var/lib/dhcp/dhclient6.eth0.leases eth0
 145 # env
 146 # ADDRFAM=inet
 147 # PHASE=post-up
 148 # VERBOSITY=0
 149 # PWD=/sbin
 150 # IFACE=eth0
 151 # METHOD=dhcp
 152 # SHLVL=1
 153 # LOGICAL=eth0
 154 # MODE=start
 155 # PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
 156 # IFUPDOWN_eth0=post-up
 157 # _=/usr/bin/env