[pve-devel] [RFC pve-network 9/9] dhcp : dnsmasq: add_mapping: remove old mac, ip before append

[Alexandre Derumier <aderumier@odiso.com>]

Signed-off-by: Alexandre Derumier <aderumier@odiso.com>
---
 src/PVE/Network/SDN/Dhcp/Dnsmasq.pm | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm b/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm
index 64895ef..21a6ddd 100644
--- a/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm
+++ b/src/PVE/Network/SDN/Dhcp/Dnsmasq.pm
@@ -54,12 +54,24 @@ sub del_ip_mapping {
 
 sub add_ip_mapping {
     my ($class, $dhcpid, $mac, $ip) = @_;
+
     my $ethers_file = "$DNSMASQ_CONFIG_ROOT/$dhcpid/ethers";
+    my $ethers_tmp_file = "$ethers_file.tmp";
 
     my $appendFn = sub {
-	open(my $fh, '>>', $ethers_file) or die "Could not open file '$ethers_file' $!\n";
-	print $fh "$mac,$ip\n";
-	close $fh;
+	open(my $in, '<', $ethers_file) or die "Could not open file '$ethers_file' $!\n";
+	open(my $out, '>', $ethers_tmp_file) or die "Could not open file '$ethers_tmp_file' $!\n";
+
+        while (my $line = <$in>) {
+	    next if $line =~ m/^$mac/;
+	    print $out $line;
+	}
+
+	print $out "$mac,$ip\n";
+	close $in;
+	close $out;
+	move $ethers_tmp_file, $ethers_file;
+	chmod 0644, $ethers_file;
     };
 
     PVE::Tools::lock_file($ethers_file, 10, $appendFn);
-- 
2.39.2