#!/bin/sh

PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin

# Data sources
src_asnames="https://ftp.ripe.net/ripe/asnames/asn.txt"
src_route4="https://ftp.ripe.net/ripe/dbase/split/ripe.db.route.gz"
src_route6="https://ftp.ripe.net/ripe/dbase/split/ripe.db.route6.gz"

# Local storage for downloads and results
dir="/var/db/ripe"
dest_asnames="$dir/asn.txt"
dest_route4="$dir/ripe.db.route.gz"
dest_route6="$dir/ripe.db.route6.gz"
route4="${dest_route4%.gz}"
route6="${dest_route6%.gz}"

# Results
prefix4="$dir/prefix4"
prefix4_full="$prefix4.full"
prefix6="$dir/prefix6"
prefix6_full="$prefix6.full"

updated="unknown"
fetch_timeout="5"	# seconds
temp="$dir/tmp.$$"

set -e
LANG=C LC_ALL=C
install -d "$dir"

force=no
[ "$1" = "-f" ] && force=yes
trap 'rm -f "$temp" "$temp.2"' EXIT

# args: url localfile
update_file() {
  local check src dst
  src="$1" dst="$2"

  # Download it with time modification check unless forced mode.
  [ -e "$dst" ] || echo -n > "$dst" || return 1
  [ "$force" = no ] && check='-i "$dst"'
  eval fetch --no-verify-peer -4aqT "$fetch_timeout" $check -o \"$temp\" \"$src\" || return 1
  ! [ -s "$temp" ] && updated=no && return 0 # no updates

  [ $force = no ] && cmp -sz "$temp" "$dst" && updated=no && return 0
  mv "$temp" "$dst" || return 1
  updated=yes
  return 0
}

# no args
update_asnames() {
  update_file "$src_asnames" "$dest_asnames"
  [ "$updated" = no ] && exit 0
  return 0
}

# no args
update_routes() {
  update_file "$src_route4" "$dest_route4" && \
    gunzip < "$dest_route4" > "$temp" && mv "$temp" "$route4"
# update_file "$src_route6" "$dest_route6" && \
#   gunzip < "$dest_route6" > "$temp" && mv "$temp" "$route6"
}

# args: asnfile countryname routefile result_aggregated result_full
#
# 1. Filter asnfile by countryname.
# 2. Filter routefile by filtered asnfile from above removing duplicates.

filter_prefixes() {
  local aggregated full
  aggregated="$4" full="$5"

  awk -vlist="$1" -vcountry="$2" '
    BEGIN {
      cmd = "cat " list
      while((cmd | getline) == 1) { if ($NF == country) { asn["AS" $1] = 1 } }
    }
    $1 == "route:" || $1 == "route6:"	{ prefix = $2 }
    $1 == "origin:" { if (asn[$2] == 1) { result[prefix] = 1 } }
    END { for(prefix in result) { print prefix } }
   ' "$3" > "$temp"
  [ -s "$temp" ]
  mv "$temp" "$full"
  iprange "$full" > "$temp"
  [ -s "$temp" ]
  mv "$temp" "$aggregated"
}

update_asnames
update_routes
filter_prefixes "$dest_asnames" RU "$route4" "$prefix4" "$prefix4_full"