From: Nick Porter <nick@portercomputing.co.uk>
Date: Tue, 17 Jun 2025 09:22:02 +0000 (+0100)
Subject: Walk over DHCPv4 padding option rather than returning NULL
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b3f996f;p=thirdparty%2Ffreeradius-server.git

Walk over DHCPv4 padding option rather than returning NULL

Some clients put padding in the middle of packets - so the option we're
looking for may be after the padding.
---

diff --git a/src/protocols/dhcpv4/packet.c b/src/protocols/dhcpv4/packet.c
index c17c3ec21b..6d0d0d6390 100644
--- a/src/protocols/dhcpv4/packet.c
+++ b/src/protocols/dhcpv4/packet.c
@@ -48,7 +48,11 @@ uint8_t const *fr_dhcpv4_packet_get_option(dhcp_packet_t const *packet, size_t p
 	data = &packet->options[where];
 
 	while (where < size) {
-		if (data[0] == 0) return NULL; /* padding */
+		if (data[0] == 0) { /* padding */
+			where++;
+			data++;
+			continue;
+		}
 
 		if (data[0] == 255) { /* end of options */
 			if ((field == DHCP_OPTION_FIELD) && (overload & DHCP_FILE_FIELD)) {