add cidr matching

1 files changed, 30 insertions, 0 deletions

diff --git a/upload.php b/upload.php
index 180f508..dcdccb1 100644
--- a/upload.php
+++ b/upload.php
@@ -155,5 +155,35 @@ function remap_files() {
 }
 
 function get_addr() {
+	foreach (KNOWN_CIDRS as $cidr => $name) {
+		if (cidr_matches($cidr, $_SERVER['REMOTE_ADDR'])) {
+			return sprintf('%s (%s)', $_SERVER['REMOTE_ADDR'], $name);
+		}
+	}
 	return $_SERVER['REMOTE_ADDR'];
 }
+
+function ip_to_bits($ip) {
+	$splitted = str_split(inet_pton($ip));
+	$binaryip = '';
+	foreach ($splitted as $char) {
+		$binaryip .= str_pad(decbin(ord($char)), 8, '0', STR_PAD_LEFT);
+	}
+	return $binaryip;
+}
+function cidr_matches($cidr, $ip) {
+	$binaryip = ip_to_bits($ip);
+
+	$pieces = explode('/', $cidr);
+	$binarynet = ip_to_bits($pieces[0]);
+	if (count($pieces) > 1) {
+		$mask = $pieces[1];
+	} else {
+		$mask = strlen($binarynet);
+	}
+
+	$ip_net_bits = substr($binaryip, 0, $mask);
+	$net_bits = substr($binarynet, 0, $mask);
+
+	return ($ip_net_bits === $net_bits);
+}