From: Roy Marples <roy@marples.name>
Date: Sat, 13 Sep 2025 11:45:50 +0000 (+0100)
Subject: ND Route Information Option prefix is optional
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6dcb1569fc782a8f8a5e8855faee5aadcc769554;p=thirdparty%2Fdhcpcd.git

ND Route Information Option prefix is optional

As the length could be zero and is RFC compliant.
Fixes #527.
---

diff --git a/src/dhcpcd-definitions-small.conf b/src/dhcpcd-definitions-small.conf
index 2f231286..0c874ae1 100644
--- a/src/dhcpcd-definitions-small.conf
+++ b/src/dhcpcd-definitions-small.conf
@@ -74,7 +74,7 @@ embed		byte			length
 # bits 4 and 5 are route preference
 embed		bitflags=00011		prf
 embed		uint32			lifetime
-embed		truncated ip6address	prefix
+embed		optional truncated ip6address	prefix
 
 # ND6 options, RFC6101
 definend 25	index embed		rdnss
diff --git a/src/dhcpcd-definitions.conf b/src/dhcpcd-definitions.conf
index 5c9230de..e350aa9f 100644
--- a/src/dhcpcd-definitions.conf
+++ b/src/dhcpcd-definitions.conf
@@ -417,7 +417,7 @@ embed		byte			length
 # bits 4 and 5 are route preference
 embed		bitflags=00011		prf
 embed		uint32			lifetime
-embed		truncated ip6address	prefix
+embed		optional truncated ip6address	prefix
 
 # ND6 options, RFC6101
 definend 25	index embed		rdnss
diff --git a/src/if-options.c b/src/if-options.c
index 3cb89f35..2819113d 100644
--- a/src/if-options.c
+++ b/src/if-options.c
@@ -2093,7 +2093,7 @@ err_sla:
 				t |= OT_RESERVED;
 			}
 		}
-		if (t & OT_TRUNCATED && t != (OT_ADDRIPV6 | OT_TRUNCATED)) {
+		if (t & OT_TRUNCATED && !(t & OT_ADDRIPV6)) {
 			logerrx("truncated only works for ip6address");
 			return -1;
 		}