From: Christian Tomahogh <ctomahogh@insys-tec.de>
Date: Thu, 28 Sep 2023 23:04:37 +0000 (+0200)
Subject: Send correct amount of used buffer for prefix exclude option (#250)
X-Git-Tag: v10.0.3~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f2bc729e555e753625e98a705ea2aac5f8dc3cb3;p=thirdparty%2Fdhcpcd.git

Send correct amount of used buffer for prefix exclude option (#250)

The payload of the prefix exclude option was correctly created
but the amount of bytes to send in the DHCPv6 request was
always set to 0 which resulted in an invalid prefix exclude option

This patch fixes this behavior by calculating the correct amount
of bytes to send.
---

diff --git a/src/dhcp6.c b/src/dhcp6.c
index e7767ca7..c7fc3859 100644
--- a/src/dhcp6.c
+++ b/src/dhcp6.c
@@ -1022,9 +1022,11 @@ dhcp6_makemessage(struct interface *ifp)
 						n--;
 					while (n-- > 0)
 						*ep++ = *pp--;
-					if (u8)
+					n = ep - exb;
+					if (u8) {
 						*ep = (uint8_t)(*pp << u8);
-					n++;
+						n++;
+					}
 					COPYIN(D6_OPTION_PD_EXCLUDE, exb,
 					    (uint16_t)n);
 					ia_na_len = (uint16_t)