Global rate limit for client

src/freedombone-client

 # refresh gpg keys every few hours
 REFRESH_GPG_KEYS_HOURS=2
 
+function global_rate_limit {
+    sudo cp /etc/sysctl.conf ~/sysctl.conf
+    if ! grep -q "tcp_challenge_ack_limit" ~/sysctl.conf; then
+        echo 'net.ipv4.tcp_challenge_ack_limit = 999999999' >> ~/sysctl.conf
+    else
+        sed -i 's|net.ipv4.tcp_challenge_ack_limit.*|net.ipv4.tcp_challenge_ack_limit = 999999999|g' ~/sysctl.conf
+    fi
+    sudo cp ~/sysctl.conf /etc/sysctl.conf
+    sudo rm ~/sysctl.conf
+    sudo sysctl -p
+}
+
 function refresh_gpg_keys {
     if [ ! -f /usr/bin/gpg ]; then
         sudo apt-get -y install gnupg
 echo $'Configuring client'
 refresh_gpg_keys
 configure_ssh_client
+global_rate_limit
 configure_monkeysphere
 if [[ $MESH_CLIENT_INSTALL == $'yes' || $MESH_CLIENT_INSTALL == $'y' || $MESH_CLIENT_INSTALL == $'on' ]]; then
     echo $'Installing mesh packages'