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| #/bin/sh | |
| set -eu | |
| ip2dec () { | |
| local ip="$1" | |
| if test -z "$ip"; then | |
| printf "Argument required" 1>&2 | |
| return 1 | |
| fi | |
| if test "$(printf '%s' "$ip" | tr -dc "." | wc -c)" -gt 3; then | |
| printf "Invalid IPv4 address syntax: %s" "$ip" 1>&2 | |
| return 1 | |
| fi | |
| local chunk i=3 dec=0 | |
| for chunk in $(printf '%s' "$ip" | sed 's/\./ /g'); do | |
| if ! test "$chunk" -eq "$chunk" 2>/dev/null; then | |
| printf "Each chunks of IPv4 address must be integer: %s" "$ip" 1>&2 | |
| return 1 | |
| fi | |
| if test "$((chunk >> 8))" -ne 0; then | |
| printf "Each chunks of IPv4 address must be in range (0 .. 255): %s" "$ip" 1>&2 | |
| return 1 | |
| fi | |
| dec=$(( dec + (chunk << 8 * i) )) | |
| i=$((i - 1)) | |
| done | |
| printf '%d\n' "$dec" | |
| } | |
| dec2ip () { | |
| local dec="$1" | |
| if ! test "$dec" -eq "$dec" 2>/dev/null; then | |
| printf "dec2ip requires decimal: %s" "$dec" 1>&2 | |
| return 1 | |
| fi | |
| if test "$((dec >> 32))" -ne 0; then | |
| printf "dec2ip requires 32 bit integer: %s" "$dec" 1>&2 | |
| return 1 | |
| fi | |
| local i ip sep | |
| for i in $(seq 4); do | |
| ip=$(printf "%s%s%s" "$((dec & 0xff))" "${sep:-}" "${ip:-}") | |
| dec=$((dec >> 8)) | |
| sep=. | |
| done | |
| printf '%s\n' "$ip" | |
| } | |
| cidr_match () { | |
| local ip_dec cidr | |
| ip_dec=$(ip2dec "$1") | |
| cidr="$2" | |
| local cidraddr cidrmask | |
| IFS=/ read -r cidraddr cidrmask <<__CIDR | |
| $cidr | |
| __CIDR | |
| local cidraddr_dec cidrmask_dec | |
| cidraddr_dec=$(ip2dec "$cidraddr") | |
| cidrmask_dec=$(mask2dec "$cidrmask") | |
| if test "$(( cidraddr_dec & cidrmask_dec ))" -ne "$cidraddr_dec"; then | |
| printf "Invalid CIDR address: %s" "$cidr" 1>&2 | |
| return 1 | |
| fi | |
| local masked_ip_dec=$((ip_dec & cidrmask_dec)) | |
| test "$masked_ip_dec" -eq "$cidraddr_dec" | |
| } | |
| mask2dec () { | |
| local mask="$1" | |
| if ! test "$mask" -eq "$mask" 2>/dev/null; then | |
| printf "Integer required for mask: %s" "$mask" 1>&2 | |
| return 1 | |
| fi | |
| if test "$mask" -lt 0 -o 32 -lt "$mask"; then | |
| printf "Mask must be in range (0 .. 32): %s" "$mask" 1>&2 | |
| return 1 | |
| fi | |
| local dec=$(( -1 << (32 - mask) )) | |
| printf '%d\n' "$dec" | |
| } |
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