From: Michael Tremer <michael.tremer@ipfire.org>
Date: Tue, 25 Apr 2017 11:52:29 +0000 (+0100)
Subject: captive: Get MAC address of a device without calling arp
X-Git-Tag: v2.19-core115~60^2~47
X-Git-Url: http://git.ipfire.org/?p=people%2Fpmueller%2Fipfire-2.x.git;a=commitdiff_plain;h=dbfd2622f58727f4b0f9bed8934a770a2050491f

captive: Get MAC address of a device without calling arp

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/config/cfgroot/network-functions.pl b/config/cfgroot/network-functions.pl
index 66f1ed554a..93b8190305 100644
--- a/config/cfgroot/network-functions.pl
+++ b/config/cfgroot/network-functions.pl
@@ -374,6 +374,26 @@ sub wifi_get_signal_level($) {
 
 	return $signal_level;
 }
+
+sub get_hardware_address($) {
+	my $ip_address = shift;
+	my $ret;
+
+	open(FILE, "/proc/net/arp") or die("Could not read ARP table");
+
+	while (<FILE>) {
+		my ($ip_addr, $hwtype, $flags, $hwaddr, $mask, $device) = split(/\s+/, $_);
+		if ($ip_addr eq $ip_address) {
+			$ret = $hwaddr;
+			last;
+		}
+	}
+
+	close(FILE);
+
+	return $ret;
+}
+
 1;
 
 # Remove the next line to enable the testsuite
diff --git a/html/cgi-bin/captive/index.cgi b/html/cgi-bin/captive/index.cgi
index 05619b47c3..bcaf8561af 100755
--- a/html/cgi-bin/captive/index.cgi
+++ b/html/cgi-bin/captive/index.cgi
@@ -58,9 +58,8 @@ if ($cgiparams{'ACTION'} eq "SUBMIT") {
 	#Get Clients IP-Address
 	my $ip_address = $ENV{X_FORWARDED_FOR} || $ENV{REMOTE_ADDR} ||"";
 
-	#Ask arp to give the corresponding MAC-Address
-	my $mac_address = qx(arp -a|grep $ip_address|cut -d ' ' -f 4);
-	$mac_address =~ s/\n+\z//;
+	# Retrieve the MAC address from the ARP table
+	my $mac_address = &Network::get_hardware_address($ip_address);
 
 	&General::readhasharray("$clients", \%clientshash);
 	my $key = &General::findhasharraykey(\%clientshash);
@@ -84,15 +83,13 @@ if ($cgiparams{'ACTION'} eq "SUBMIT") {
 
 if ($cgiparams{'ACTION'} eq "SUBMIT") {
 	my $ip_address;
-	my $mac_address;
 	my $granted=0;
 	#Convert voucherinput to uppercase
 	$cgiparams{'VOUCHER'} = uc $cgiparams{'VOUCHER'};
 	#Get Clients IP-Address
 	$ip_address = $ENV{X_FORWARDED_FOR} || $ENV{REMOTE_ADDR} ||"";
 	#Ask arp to give the corresponding MAC-Address
-	$mac_address = qx(arp -a|grep $ip_address|cut -d ' ' -f 4);
-	$mac_address =~ s/\n+\z//;
+	my $mac_address = &Network::get_hardware_address($ip_address);
 	#Check if voucher is valid and write client to clients file, delete voucher from voucherout
 	&General::readhasharray("$voucherout", \%voucherhash);
 	&General::readhasharray("$clients", \%clientshash);