#!/bin/sh

# SPDX-License-Identifier: GPL-3.0-or-later
#
# Legacy Isolario bgpscanner compatible wrapper for ubgpsuite tools.
# Emulates most of the classic bgpscanner CLI.
#
# Copyright The DoubleFourteen Code Forge (C) All Rights Reserved
# Author:   Lorenzo Cogotti

NAME=$(basename "$0")
TGT=bgpgrep
OPTS=""

PEERAS=""
PEERASF=""
PEERADDR=""
PEERADDRF=""
ATTRS=""
COMMS=""
NCOMMS=""
EXACT=""
EXACTF=""
SUBNETS=""
SUBNETSF=""
SUPNETS=""
SUPNETSF=""
RELATED=""
RELATEDF=""
LOOPS="unspec"
REXPS=""
NREXPS=""
DUMPBYTEC="no"
OUTREDIR=""

die() {
    echo "$NAME: $*" >&2
    exit 1
}

usage() {
    echo "$NAME: Legacy bgpscanner-compatible wrapper for ubgpsuite tools" >&2
    echo "Usage:" >&2
    echo "  $NAME [-cdlL] [-mM COMMSTRING] [-pP PATHEXPR] [-i ADDR] [-I FILE] [-a AS] [-A FILE] [-e PREFIX] [-E FILE] [-t ATTR_CODE] [-T FILE] [-o FILE] [FILE...]" >&2
    echo "  $NAME [-cdlL] [-mM COMMSTRING] [-pP PATHEXPR] [-i ADDR] [-I FILE] [-a AS] [-A FILE] [-s PREFIX] [-S FILE] [-t ATTR_CODE] [-T FILE] [-o FILE] [FILE...]" >&2
    echo "  $NAME [-cdlL] [-mM COMMSTRING] [-pP PATHEXPR] [-i ADDR] [-I FILE] [-a AS] [-A FILE] [-u PREFIX] [-U FILE] [-t ATTR_CODE] [-T FILE] [-o FILE] [FILE...]" >&2
    echo "  $NAME [-cdlL] [-mM COMMSTRING] [-pP PATHEXPR] [-i ADDR] [-I FILE] [-a AS] [-A FILE] [-r PREFIX] [-R FILE] [-t ATTR_CODE] [-T FILE] [-o FILE] [FILE...]" >&2
    echo >&2
    echo "Available options:" >&2
    echo "  -a <peer AS>" >&2
    echo "    Print only entries coming from the given peer AS" >&2
    echo "  -A <file>" >&2
    echo "    Print only entries coming from any peer AS listed in file" >&2
#    echo "  -c" >&2
#    echo "    Dump BGP messages in hexadecimal C array format" >&2
    echo "  -d" >&2
    echo "    Dump BGP filter bytecode to stderr (debug option)" >&2
    echo "  -e <prefix>" >&2
    echo "    Print only entries containing the exact prefix of interest" >&2
    echo "  -E <file>" >&2
    echo "    Print only entries containing exactly any prefix of interest listed in file" >&2
    echo "  -f" >&2
    echo "    Print every peer IP address in the RIB provided" >&2
    echo "  -i <peer IP>"
    echo "    Print only entries coming from a given peer IP address" >&2
    echo "  -I <file>" >&2
    echo "    Print only entries coming from any peer IP address listed in file" >&2
    echo "  -l" >&2
    echo "    Print only entries with loops in their AS PATH" >&2
    echo "  -L" >&2
    echo "    Print only entries without loops in their AS PATH" >&2
    echo "  -o <file>" >&2
    echo "    Redirect output to file (defaults to stdout)" >&2
    echo "  -m <communities string>" >&2
    echo "    Print only entries whose COMMUNITY attribute contains the given communities (in any order)" >&2
    echo "  -M <communities string>" >&2
    echo "    Print only entries whose COMMUNITY attribute does not contain the given communities (in any order)" >&2
    echo "  -p <path expression>" >&2
    echo "    Print only entries whose AS PATH matches the given expression" >&2
    echo "  -P <path expression>" >&2
    echo "    Print only entries whose AS PATH does not match the given expression" >&2
    echo "  -r <prefix>" >&2
    echo "    Print only entries containing subnets or supernets of the given prefix (including the prefix itself)" >&2
    echo "  -R <file>" >&2
    echo "    Print only entries containing subnets or supernets of any prefix listed in file (including the prefix itself)" >&2
    echo "  -s <subnet>" >&2
    echo "    Print only entries containing subnets of the given prefix" >&2
    echo "  -S <file>" >&2
    echo "    Print only entries containing subnets of any prefix listed in file" >&2
    echo "  -t <attribute code>" >&2
    echo "    Print only entries containing the given interesting attribute" >&2
#    echo "  -T <file>" >&2
#    echo "    Print only entries containing any of the interesting attributes listed in file" >&2
    echo "  -u <prefix>"
    echo "    Print only entries containing supernets of the given prefix (including the prefix itself)" >&2
    echo "  -U <file>" >&2
    echo "    Print only entries containing supernets of any prefix listed in file (including the prefix itself)" >&2
    exit 1
}

chkint() {
    case "$1" in
    ''|*[!0-9]*) die "'$1': Non negative integer expected";;
    *) ;;
    esac
}
isip4() {
    for i in 1 2 3 4; do
        case $(printf %s\\n "$1" | cut -d. -f"$i") in
        [0-9]|[0-9][0-9]|[0-1][0-9][0-9]|2[0-4][0-9]|25[0-5]) return 0;;
        *) return 1;;
        esac
    done
}
isip6() {
    test "$( \
        printf %s\\n "$1" | \
        grep -Ec '^(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]).){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]).){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))$' \
    )" -eq 1
}
chkip() { isip4 "$1" || isip6 "$1" || die "'$1': Invalid IP address"; }
chkprefix() {
    case "$1" in
    */*) chkint "${1#*/}" && chkip "${1%/*}";;
    *) chkip "$1";;
    esac
}
chknospc() {
    case "$1" in
    ''|*[[:space:]]*) die "'$1': Invalid argument";;
    *) ;;
    esac
}
chkcomm() {
    case "$1" in
    ''|*[![:space:][:alnum:]\:]*) die "'$1': Invalid COMMUNITY expression";;
    *) ;;
    esac
}
chkrexp() {
    case "$1" in
    ''|*[![:digit:][:space:]^$\?\*]*) die "'$1': Invalid AS_PATH expression";;
    *) ;;
    esac
}

templatef() {
    TPL=$(mktemp)
    [ $? -eq 0 ] || exit 1

    sed -e 's/#.*$//g' "$1" | awk 'BEGIN {
        FPAT = "([^ ]*)|(\"[^\"]*\")"
    } {
        for (i=1; i<=NF; i++) { print $i }
    }' | while read -r TOK; do
        [ -z "$TOK" ] && continue

        UNQL="${TOK%\"}"
        UNQR="${TOK#\"}"
        UNQ="${UNQL#\"}"
        [ "$UNQL" != "$UNQR" ] && die "'$TOK': Illegal misquoted or multiline token"

        [ -n "$2" ] && "$2" "$UNQ"
        [ $? -ne 0 ] && exit 1

        printf %s\\n "$UNQ"
    done > "$TPL" || die "'$1': File conversion failed"

    printf %s\\n "$TPL"
}

quote() { printf %s\\n "$1" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/'/"; }

append() { printf %s\\n "${1:+${1}${3:+ ${3}} }${2}"; }

TERM=""
EXPR=""

appendtermargs() {
    _T=$1; shift
    TERM="$_T \( $* \)"
}

appendtermfiles() {
    _T=$1; shift

    for i in "$@"; do _L=$(append "$_L" "$_T $i" "-or"); done

    [ -n "$TERM" ] && TERM="\( $TERM -or $_L \)" || TERM="$_L"
}

pushterm() {
    if [ -n "$TERM" ]; then EXPR=$(append "$EXPR" "$TERM"); TERM=""; fi
}

exprcompile() {
    [ -n "$PEERAS" ] || [ -n "$PEERADDR" ] && appendtermargs -peer $PEERAS $PEERADDR
    [ -n "$PEERASF" ] || [ -n "$PEERADDRF" ] && appendtermfiles -peer $PEERASF $PEERADDRF
    pushterm

    for i in $ATTRS; do TERM=$(append "$TERM" "-attr $i" "-or"); done
    [ "$(printf %s\\n "$ATTRS" | wc -w)" -gt 1 ] && TERM="\( $TERM \)"
    pushterm

    [ -n "$NCOMMS" ] && TERM="-not -communities \( $NCOMMS \)"
    [ -n "$COMMS" ] && TERM=$(append "$TERM" "-all-communities \( $COMMS \)" "-or")
    [ -n "$NCOMMS" ] && [ -n "$COMMS" ] && TERM="\( $TERM \)"
    pushterm

    [ -n "$EXACT" ] && appendtermargs -exact $EXACT
    [ -n "$EXACTF" ] && appendtermfiles -exact $EXACTF
    pushterm
    [ -n "$SUBNETS" ] && appendtermargs -subnet $SUBNETS
    [ -n "$SUBNETSF" ] && appendtermfiles -subnet $SUBNETSF
    pushterm
    [ -n "$SUPNETS" ] && appendtermargs -supernet $SUPNETS
    [ -n "$SUPNETSF" ] && appendtermfiles -supernet $SUPNETSF
    pushterm
    [ -n "$RELATED" ] && appendtermargs -related $RELATED
    [ -n "$RELATEDF" ] && appendtermfiles -related $RELATEDF
    pushterm

    if [ "$LOOPS" != unspec ]; then
        [ "$LOOPS" = yes ] && TERM="-loops" || TERM="-not -loops"
        pushterm
    fi

    [ -n "$REXPS" ] && TERM="-aspath \"$REXPS\""
    [ -n "$NREXPS" ] && TERM=$(append "$TERM" "-not -aspath \"$NREXPS\"" "-or")
    [ -n "$REXPS" ] && [ -n "$NREXPS" ] && TERM="\( $TERM \)"
    pushterm
}

execute() {
    eval "set -- $OPTS -- "$@" $EXPR"
    "$CMD" "$TGT" "$@"
}

GOTEXACT=""; GOTRELATED=""; GOTSUBNETS=""; GOTSUPNETS=""
while getopts "a:A:cde:E:fi:I:lLo:m:M:p:P:r:R:s:S:t:T:u:U:" o; do
    case $o in
    a) chkint "$OPTARG"
       PEERAS=$(append "$PEERAS" "$OPTARG")
       ;;
    A) TPL=$(templatef "$OPTARG" chkint) || exit 1
       PEERASF=$(append "$PEERASF" "$TPL")
       ;;
    c) die "Sorry, option -c is not supported yet!"
       ;;
    d) DUMPBYTEC=yes
       ;;
    e) chkprefix "$OPTARG"
       GOTEXACT=y; EXACT=$(append "$EXACT" "$OPTARG")
       ;;
    E) TPL=$(templatef "$OPTARG" chkprefix) || exit 1
       GOTEXACT=y; EXACTF=$(append "$EXACTF" "$TPL")
       ;;
    f) TGT=peerindex
       ;;
    i) chkip "$OPTARG"
       PEERADDR=$(append "$PEERADDR" "$OPTARG")
       ;;
    I) TPL=$(templatef "$OPTARG" chkip) || exit 1
       PEERADDRF=$(append "$PEERADDRF" "$TPL")
       ;;
    l) LOOPS=yes
       ;;
    L) LOOPS=no
       ;;
    m) chkcomm "$OPTARG"
       COMMS=$(append "$COMMS" "$OPTARG")
       ;;
    M) chkcomm "$OPTARG"
       NCOMMS=$(append "$NCOMMS" "$OPTARG")
       ;;
    o) OUTREDIR="$OPTARG"
       ;;
    p) chkrexp "$OPTARG"
       REXPS=$(append "$REXPS" "$(printf %s\\n "$OPTARG" | tr "?" ".")" "|")
       ;;
    P) chkrexp "$OPTARG"
       NREXPS=$(append "$NREXPS" "$(printf %s\\n "$OPTARG" | tr "?" "." )" "|")
       ;;
    r) chkprefix "$OPTARG"
       GOTRELATED=y; RELATED=$(append "$RELATED" "$OPTARG")
       ;;
    R) TPL=$(templatef "$OPTARG" chkprefix) || exit 1
       GOTRELATED=y; RELATEDF=$(append "$RELATEDF" "$TPL")
       ;;
    s) chkprefix "$OPTARG"
       GOTSUBNETS=y; SUBNETS=$(append "$SUBNETS" "$OPTARG")
       ;;
    S) TPL=$(templatef "$OPTARG" chkprefix) || exit 1
       GOTSUBNETS=y; SUBNETSF=$(append "$SUBNETSF" "$TPL")
       ;;
    t) chknospc "$OPTARG"
       ATTRS=$(append "$ATTRS" "$OPTARG")
       ;;
    T) die "Sorry, option -T is not supported yet!"
       ;;
    u) chkprefix "$OPTARG"
       GOTSUPNETS=y; SUPNETS=$(append "$SUPNETS" "$OPTARG")
       ;;
    U) TPL=$(templatef "$OPTARG" chkprefix) || exit 1
       GOTSUPNETS=y; SUPNETSF=$(append "$SUPNETSF" "$TPL")
       ;;
    ?) usage
       ;;
    esac
done

GOTNETS="${GOTSUBNETS}${GOTSUPNETS}${GOTEXACT}${GOTRELATED}"

shift $(( OPTIND-1 ))

exprcompile

[ -n "$EXPR" ] && [ "$TGT" != bgpgrep ] && die "Conflicting options"
[ -n "$GOTNETS" ] && [ "$GOTNETS" != "y" ] && die "Conflicting options"

[ "$TGT"  = bgpgrep ] && [ "$DUMPBYTEC" = yes ] && OPTS=$(append "$OPTS" --dump-bytecode)
[ "$TGT" != bgpgrep ] && OPTS=-r

[ -n "$OUTREDIR" ] && OPTS=$(append "$OPTS" "-o \"$OUTREDIR\"")

CMD="exec"
if [ -n "$PRETEND" ] && [ "$PRETEND" = 1 ] || [ "$PRETEND" = y ] || [ "$PRETEND" = yes ]; then
    CMD="echo"
    OPTS=$(quote "$OPTS")
    EXPR=$(quote "$EXPR")
fi

execute "$@"