#!/bin/sh
#
# Copyright (c) 2018-2024, Christer Edwards <christer.edwards@gmail.com>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright notice,
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
#
# * Neither the name of the copyright holder nor the names of its
#   contributors may be used to endorse or promote products derived from
#   this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

. /usr/local/share/bastille/common.sh
. /usr/local/etc/bastille/bastille.conf

usage() {
    error_notify "Usage: bastille rdr TARGET [options(s)] [clear|reset|list|(tcp|udp)] host_port jail_port [log ['(' logopts ')'] ] )]"

    cat << EOF
    Options:

    -i | --interface   [interface]      | -- Set the interface to create the rdr rule on. Useful if you have multiple interfaces.
    -s | --source      [source ip]      | -- Limit rdr to a source IP. Useful to only allow access from a certian IP or subnet.
    -d | --destination [destination ip] | -- Limit rdr to a destination IP. Useful if you have multiple IPs on one interface.
    -t | --type        [ipv4|ipv6]      | -- Specify IP type. Must be used if -s or -d are used. Defaults to both.

EOF
    exit 1
}

# Handle special-case commands first.
case "$1" in
help|-h|--help)
    usage
    ;;
esac

if [ $# -lt 2 ]; then
    usage
fi

bastille_root_check

TARGET="${1}"
JAIL_NAME=""
JAIL_IP=""
JAIL_IP6=""
shift

check_jail_validity() {
    # Can only redirect to single jail
    if [ "${TARGET}" = 'ALL' ]; then
        error_exit "Can only redirect to a single jail."
    fi

    # Check if jail name is valid
    JAIL_NAME=$(/usr/sbin/jls -j "${TARGET}" name 2>/dev/null)
    if [ -z "${JAIL_NAME}" ]; then
        error_exit "Jail not found: ${TARGET}"
    fi

    # Check if jail ip4 address (ip4.addr) is valid (non-VNET only)
    if [ "$(bastille config $TARGET get vnet)" != 'enabled' ]; then
        JAIL_IP=$(/usr/sbin/jls -j "${TARGET}" ip4.addr 2>/dev/null)
        if [ -z "${JAIL_IP}" -o "${JAIL_IP}" = "-" ]; then
            error_exit "Jail IP not found: ${TARGET}"
        fi
    fi
    # Check if jail ip6 address (ip6.addr) is valid (non-VNET only)
    if [ "$(bastille config $TARGET get vnet)" != 'enabled' ]; then
        if [ "$(bastille config $TARGET get ip6)" != 'disable' ] && [ "$(bastille config $TARGET get ip6)" != 'not set' ]; then
            JAIL_IP6=$(/usr/sbin/jls -j "${TARGET}" ip6.addr 2>/dev/null)
        fi
    fi

    # Check if rdr-anchor is defined in pf.conf
    if ! (pfctl -sn | grep rdr-anchor | grep 'rdr/\*' >/dev/null); then
        error_exit "rdr-anchor not found in pf.conf"
    fi
}

check_rdr_ip_validity() {
    local ip="$1"
    local ip6=$(echo "${ip}" | grep -E '^(([a-fA-F0-9:]+$)|([a-fA-F0-9:]+\/[0-9]{1,3}$)|SLAAC)')
    if [ -n "${ip6}" ]; then
        info "Valid: (${ip6})."
    else
        local IFS
        if echo "${ip}" | grep -Eq '^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/([0-9]|[1-2][0-9]|3[0-2]))?$'; then
            TEST_IP=$(echo "${ip}" | cut -d / -f1)
            IFS=.
            set ${TEST_IP}
            for quad in 1 2 3 4; do
                if eval [ \$$quad -gt 255 ]; then
                    error_exit "Invalid: (${TEST_IP})"
                fi
            done
            info "Valid: (${ip})."
        else
            error_exit "Invalid: (${ip})."
        fi
    fi
}

# function: write rule to rdr.conf
persist_rdr_rule() {
    local inet="${1}"
    local if="${2}"
    local src="${3}"
    local dst="${4}"
    local proto="${5}"
    local host_port="${6}"
    local jail_port="${7}"
    if ! grep -qs "$inet $if $src $dst $proto $host_port $jail_port" "${bastille_jailsdir}/${JAIL_NAME}/rdr.conf"; then
        echo "$inet $if $src $dst $proto $host_port $jail_port" >> "${bastille_jailsdir}/${JAIL_NAME}/rdr.conf"
    fi
}

persist_rdr_log_rule() {
    local inet="${1}"
    local if="${2}"
    local src="${3}"
    local dst="${4}"
    local proto="${5}"
    local host_port="${6}"
    local jail_port="${7}"
    shift 7;
    log=$@;
    if ! grep -qs "$inet $if $src $dst $proto $host_port $jail_port $log" "${bastille_jailsdir}/${JAIL_NAME}/rdr.conf"; then
        echo "$inet $if $src $dst $proto $host_port $jail_port $log" >> "${bastille_jailsdir}/${JAIL_NAME}/rdr.conf"
    fi
}

# function: load rdr rule via pfctl
load_rdr_rule() {
    local inet="${1}"
    local if_name="${2}"
    local if=ext_if=\"${2}\"
    local src="${3}"
    local dst="${4}"
    local proto="${5}"
    local host_port="${6}"
    local jail_port="${7}"
    # Create IPv4 rdr rule
    if [ "${inet}" = "ipv4" ] || [ "${inet}" = "dual" ]; then
        if ! ( pfctl -a "rdr/${JAIL_NAME}" -Psn 2>/dev/null;
            printf '%s\nrdr pass on $%s inet proto %s from %s to %s port %s -> %s port %s\n' "$if" "${bastille_network_pf_ext_if}" "$proto" "$src" "$dst" "$host_port" "$JAIL_IP" "$jail_port" ) \
            | pfctl -a "rdr/${JAIL_NAME}" -f-; then
            error_exit "Failed to create IPv4 rdr rule \"${if_name} ${src} ${dst} ${proto} ${host_port} ${jail_port}\""
        else
            info "[${JAIL_NAME}]:"
            echo "IPv4 ${proto}/${src}:${host_port} -> ${dst}:${jail_port} on ${if_name}" 
        fi
    fi
    # Create IPv6 rdr rule (if ip6.addr is enabled)
    if [ -n "$JAIL_IP6" ] && [ "${inet}" = "ipv6" ] || [ "${inet}" = "dual" ]; then
        if ! ( pfctl -a "rdr/${JAIL_NAME}" -Psn;
            printf '%s\nrdr pass on $%s inet6 proto %s from %s to %s port %s -> %s port %s\n' "$if" "${bastille_network_pf_ext_if}" "$proto" "$src" "$dst" "$host_port" "$JAIL_IP6" "$jail_port" ) \
            | pfctl -a "rdr/${JAIL_NAME}" -f-; then
            error_exit "Failed to create IPv6 rdr rule \"${if_name} ${src} ${dst} ${proto} ${host_port} ${jail_port}\""
        else
            info "[${JAIL_NAME}]:"
            echo "IPv6 ${proto}/${src}:${host_port} -> ${dst}:${jail_port} on ${if_name}"
        fi
    fi
}

# function: load rdr rule with log via pfctl
load_rdr_log_rule() {
    local inet="${1}"
    local if_name="${2}"
    local if=ext_if=\"${2}\"
    local src="${3}"
    local dst="${4}"
    local proto="${5}"
    local host_port="${6}"
    local jail_port="${7}"
    shift 7;
    log=$@
    # Create IPv4 rule with log
    if [ "${inet} = "ipv4" ] || [ "${inet} = "dual" ]; then
        if ! ( pfctl -a "rdr/${JAIL_NAME}" -Psn;
            printf '%s\nrdr pass %s on $%s inet proto %s from %s to %s port %s -> %s port %s\n' "$if" "$log" "${bastille_network_pf_ext_if}" "$proto" "$src" "$dst" "$host_port" "$JAIL_IP" "$jail_port" ) \
            | pfctl -a "rdr/${JAIL_NAME}" -f-; then
            error_exit "Failed to create logged IPv4 rdr rule \"${if_name} ${src} ${dst} ${proto} ${host_port} ${jail_port}\""
        else
            info "[${JAIL_NAME}]:"
            echo "IPv4 ${proto}/${src}:${host_port} -> ${dst}:${jail_port} on ${if_name}"
        fi
    fi
    # Create IPv6 rdr rule with log (if ip6.addr is enabled)
    if [ -n "$JAIL_IP6" ] && [ "${inet} = "ipv6" ] || [ "${inet} = "dual" ]; then 
        if ! ( pfctl -a "rdr/${JAIL_NAME}" -Psn;
            printf '%s\nrdr pass %s on $%s inet6 proto %s from %s to %s port %s -> %s port %s\n' "$if" "$log" "${bastille_network_pf_ext_if}" "$proto" "$src" "$dst" "$host_port" "$JAIL_IP6" "$jail_port" ) \
            | pfctl -a "rdr/${JAIL_NAME}" -f-; then
            error_exit "Failed to create logged IPv6 rdr rule \"${if_name} ${src} ${dst} ${proto} ${host_port} ${jail_port}\""
        else
            info "[${JAIL_NAME}]:"
            echo "IPv6 ${proto}/${src}:${host_port} -> ${dst}:${jail_port} on ${if_name}"
        fi
    fi
}

# Set defaults
RDR_IF="$(grep "^[[:space:]]*${bastille_network_pf_ext_if}[[:space:]]*=" ${bastille_pf_conf} | awk -F'"' '{print $2}')"
RDR_SRC="any"
RDR_DST="any"
OPTION="0"
RDR_INET="dual"
OPTION_IF=0
OPTION_SRC=0
OPTION_DST=0
OPTION_TYPE=0

# Check for options
while [ "$#" -gt 0 ]; do
    case "$1" in
        -i|--interface)
            if [ -z "${2}" ] || [ -z "${3}" ]; then
                usage
            elif ifconfig | grep -owq "${2}:"; then
                OPTION_IF=1
                RDR_IF="${2}"
                shift 2
            else
                error_exit "${2} is not a valid interface."
            fi
            ;;
        -s|--source)
            if [ -z "${2}" ] || [ -z "${3}" ]; then
                usage
            else
                check_rdr_ip_validity "${2}"
                OPTION_SRC=1
                RDR_SRC="${2}"
                shift 2
            fi
            ;;
        -d|--destination)
            if [ -z "${2}" ] || [ -z "${3}" ]; then
                usage
            elif ifconfig | grep -owq "inet ${2}"; then
                RDR_DST="${2}"
                OPTION_DST=1
                shift 2
            else
                error_exit "${2} is not an IP on this system."
            fi
            ;;
        -t|--type)
            if [ -z "${2}" ] || [ -z "${3}" ]; then
                usage
            elif [ "${2}" != "ipv4" ] && [ "${2}" != "ipv6" ]; then
                usage
            else
                OPTION_TYPE=1
                RDR_INET="${2}"
                shift 2
            fi
            ;;
        list)
            if [ "${OPTION_IF}" -eq 1 ] || [ "${OPTION_SRC}" -eq 1 ] || [ "${OPTION_DST}" -eq 1 ] || [ "${OPTION_TYPE}" -eq 1 ];then
                error_exit "Command \"${1}\" cannot be used with options."
	        elif [ -n "${2}" ]; then
                usage
            elif [ "${TARGET}" = 'ALL' ]; then
                for JAIL_NAME in $(ls "${bastille_jailsdir}" | sed "s/\n//g"); do
                    echo "${JAIL_NAME} redirects:"
                    pfctl -a "rdr/${JAIL_NAME}" -Psn 2>/dev/null
                done
            else
                check_jail_validity
                pfctl -a "rdr/${JAIL_NAME}" -Psn 2>/dev/null
            fi
            shift
            ;;
        clear)
            if [ "${OPTION_IF}" -eq 1 ] || [ "${OPTION_SRC}" -eq 1 ] || [ "${OPTION_DST}" -eq 1 ] || [ "${OPTION_TYPE}" -eq 1 ];then
                error_exit "Command \"${1}\" cannot be used with options."
	        elif [ -n "${2}" ]; then
                usage
            elif [ "${TARGET}" = 'ALL' ]; then
                for JAIL_NAME in $(ls "${bastille_jailsdir}" | sed "s/\n//g"); do
                    echo "${JAIL_NAME} redirects:"
                    pfctl -a "rdr/${JAIL_NAME}" -Fn
                done
            else
                check_jail_validity
                pfctl -a "rdr/${JAIL_NAME}" -Fn
            fi
            shift
            ;;
        reset)
            if [ "${OPTION_IF}" -eq 1 ] || [ "${OPTION_SRC}" -eq 1 ] || [ "${OPTION_DST}" -eq 1 ] || [ "${OPTION_TYPE}" -eq 1 ];then
                error_exit "Command \"${1}\" cannot be used with options."
	        elif [ -n "${2}" ]; then
                usage
            elif [ "${TARGET}" = 'ALL' ]; then
                for JAIL_NAME in $(ls "${bastille_jailsdir}" | sed "s/\n//g"); do
                    echo "${JAIL_NAME} redirects:"
                    pfctl -a "rdr/${JAIL_NAME}" -Fn
		    if rm -f "${bastille_jailsdir}"/"${JAIL_NAME}"/rdr.conf; then
                        info "[${JAIL_NAME}]: rdr.conf removed"
	            fi
                done
            else
                check_jail_validity
                pfctl -a "rdr/${JAIL_NAME}" -Fn
                if rm -f "${bastille_jailsdir}"/"${JAIL_NAME}"/rdr.conf; then
                    info "[${JAIL_NAME}]: rdr.conf removed"
	        fi
            fi
            shift
            ;;	    
        tcp|udp)
            if [ $# -lt 3 ]; then
                usage
            elif [ "${OPTION_SRC}" -eq 1 ] || [ "${OPTION_DST}" -eq 1 ] && [ "${OPTION_TYPE}" -ne 1 ];then
                error_exit "[-t|--type] must be set when using [-s|--source] or [-d|--destination]"
            elif [ $# -eq 3 ]; then
                check_jail_validity
                persist_rdr_rule $RDR_INET $RDR_IF $RDR_SRC $RDR_DST $1 $2 $3
                load_rdr_rule $RDR_INET $RDR_IF $RDR_SRC $RDR_DST $1 $2 $3
                shift "$#"
            else
                case "$4" in
                    log)
                        proto=$1
                        host_port=$2
                        jail_port=$3
                        shift 3
                        if [ $# -gt 3 ]; then
                            for last in "$@"; do
                                true
                            done
                            if [ $2 == "(" ] && [ $last == ")" ] ; then
                                check_jail_validity
                                persist_rdr_log_rule $RDR_INET $RDR_IF $RDR_SRC $RDR_DST $proto $host_port $jail_port "$@"
                                load_rdr_log_rule $RDR_INET $RDR_IF $RDR_SRC $RDR_DST $proto $host_port $jail_port "$@"                                
                                shift $#
                            else
                                usage
                            fi
                        elif [ $# -eq 1 ]; then
                            check_jail_validity
                            persist_rdr_log_rule $RDR_INET $RDR_IF $RDR_SRC $RDR_DST $proto $host_port $jail_port "$@"
                            load_rdr_log_rule $RDR_INET $RDR_IF $RDR_SRC $RDR_DST $proto $host_port $jail_port "$@"
                            shift 1
                        else
                            usage
                        fi
                        ;;
                    *)
                        usage
                        ;;
                esac
            fi
            ;;
        *)
            if [ "${OPTION}" -eq 1 ];then
                usage
            fi
            if [ "${1}" = "dual" ] || [ "${1}" = "ipv4" ] || [ "${1}" = "ipv6" ]; then
                RDR_INET="${1}"
            else 
                usage
            fi
            if [ $# -eq 7 ] && [ "${5}" = "tcp" ] || [ "${5}" = "udp" ]; then
                check_jail_validity
                persist_rdr_rule "$@"
                load_rdr_rule "$@"
                shift $#
            elif [ $# -ge 8 ] && [ "${8}" = "log" ]; then
                check_jail_validity
                persist_rdr_log_rule "$@"
                load_rdr_log_rule "$@"
                shift $#
            else
                usage
            fi
            ;;
    esac
done