ripe_available_prefixes/get_prefixes.awk
2022-02-02 06:00:53 +01:00

79 lines
1.8 KiB
Awk
Executable file

function print_prefix(prefix, count, status) {
printf "%-20s%-10s%s\n", prefix, count, status
}
function d2b(d, b) {
while(d) {
b=d%2b
d=int(d/2)
}
return b
}
function ip2dec(prefix) {
split(prefix, splitted_prefix, ".")
b1 = splitted_prefix[1] * 256^3
b2 = splitted_prefix[2] * 256^2
b3 = splitted_prefix[3] * 256
b4 = splitted_prefix[4]
return b1 + b2 + b3 + b4
}
function dec2ip(dec_prefix) {
b1 = int(dec_prefix/256^3) % 256
b2 = int(dec_prefix/256^2) % 256
b3 = int(dec_prefix/256) % 256
b4 = int(dec_prefix) % 256
return b1 "." b2 "." b3 "." b4
}
function compute_prefix(prefix, count, status) {
split(prefix, bytes, ".")
# Everything in 151.216.0.0/13 is reserved for temporary assignments
if(bytes[1] == 151 && bytes[2] >= 216 && bytes[2] <= 223) {
return
}
# Everything in 185.0.0.0/15 is reserved for IXP assignments
if(bytes[1] == 185 && bytes[2] <= 1) {
return
}
for(i = 4; i >= 0; i--) {
if(bytes[i] != 0) {
bin = d2b(bytes[i])
idx = match(bin, /0*$/)
host_bytes = 1 substr(bin, idx, 9 - idx)
split(host_bytes, msb, "")
max_count = 2^(length(msb) - 1) * 256 ^ (4 - i)
if(max_count > count) {
max_count = count
}
cidr = 32 - log(max_count)/log(2)
remainder = count - max_count
if(cidr <= 24) {
print_prefix(prefix "/" cidr, max_count, status)
count_alloc = count_alloc + 2^(24-cidr)
}
if(remainder > 0) {
new_prefix = dec2ip(ip2dec(prefix) + max_count)
compute_prefix(new_prefix, remainder, status)
}
return
}
}
}
BEGIN {
FS = "|"
print_prefix("Prefix", "Addresses", "Status")
count_alloc = 0
}
$3 == "ipv4" && $7 ~ /(reserved|available)/ && $5 >= 256 {
compute_prefix($4, $5, $7)
}
END {
print "Number of /24 available for future allocation: " count_alloc
}