#!/bin/bash

source ./kernel_config_utils.sh
source ./net_utils.sh

iptables_tcpmss_check() {
    local is_error

    is_error=false
    if ! kernel_config_check CONFIG_NETFILTER_XT_TARGET_TCPMSS xt_TCPMSS; then
        is_error=true
    fi
    if ! kernel_config_check CONFIG_NETFILTER_XT_MATCH_TCPMSS xt_tcpmss; then
        is_error=true
    fi
    if [ "$is_error" == "true" ]; then
        return 1
    fi

    if ! iptables_rule_check mangle PREROUTING -p tcp -m tcpmss --mss 666; then
        return 1
    fi
    if ! iptables_rule_check filter FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 666; then
        return 1
    fi

    return 0
}

