From: Roy Marples <roy@marples.name>
Date: Tue, 20 May 2025 21:10:41 +0000 (+0100)
Subject: IPv6: Clear previous address RA flags on receipt of a RA.
X-Git-Tag: v10.2.4~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a35afcd891ba34802a837ec920ece0a63de65186;p=thirdparty%2Fdhcpcd.git

IPv6: Clear previous address RA flags on receipt of a RA.

This allows a prefix gateway to transition from onlink to
not on link.

Fixes #506.
---

diff --git a/src/ipv6nd.c b/src/ipv6nd.c
index 39fe4731..cad5ce5b 100644
--- a/src/ipv6nd.c
+++ b/src/ipv6nd.c
@@ -189,6 +189,11 @@ static void routeinfohead_free(struct routeinfohead *);
 #define ipv6nd_free_ra(ra) ipv6nd_freedrop_ra((ra),  0)
 #define ipv6nd_drop_ra(ra) ipv6nd_freedrop_ra((ra),  1)
 
+/* Clear these addrflags on receipt of a new RA before adding the new flags
+ * dervived from the RA. */
+#define RA_STALE_FLAGS \
+	(IPV6_AF_ONLINK | IPV6_AF_AUTOCONF | IPV6_AF_ROUTER | IPV6_AF_STALE)
+
 void
 ipv6nd_printoptions(const struct dhcpcd_ctx *ctx,
     const struct dhcp_opt *opts, size_t opts_len)
@@ -1294,8 +1299,8 @@ ipv6nd_handlera(struct dhcpcd_ctx *ctx,
 				else
 					ia->prefix_pltime = ia->prefix_vltime;
 
+				ia->flags &= ~RA_STALE_FLAGS;
 				ia->flags |= flags;
-				ia->flags &= ~IPV6_AF_STALE;
 				ia->acquired = rap->acquired;
 
 #ifdef IPV6_MANAGETEMPADDR