From: Roy Marples <roy@marples.name>
Date: Sat, 26 Jan 2019 02:13:29 +0000 (+0000)
Subject: FreeBSD: avoid kernel panics when adding on-link IPv6 routes
X-Git-Tag: v7.1.1~7
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b5d6851a11522fa5f3f17cf6ecf9e3e5bf4bd625;p=thirdparty%2Fdhcpcd.git

FreeBSD: avoid kernel panics when adding on-link IPv6 routes

Also warn that OS does not support IPv6 address sharing.
---

diff --git a/src/if-bsd.c b/src/if-bsd.c
index 5ec60eb5..0f4cc008 100644
--- a/src/if-bsd.c
+++ b/src/if-bsd.c
@@ -501,7 +501,17 @@ if_route(unsigned char cmd, const struct rt *rt)
 		    !sa_is_loopback(&rt->rt_gateway))
 		{
 			rtm->rtm_index = (unsigned short)rt->rt_ifp->index;
-#ifdef __OpenBSD__
+/*
+ * OpenBSD rejects the message for on-link routes.
+ * FreeBSD-12 kernel apparently panics.
+ * I can't replicate the panic, but better safe than sorry!
+ * https://roy.marples.name/archives/dhcpcd-discuss/0002286.html
+ *
+ * Neither OS currently allows IPv6 address sharing anyway, so let's
+ * try to encourage someone to fix that by logging a waring during compile.
+ */
+#if defined(__FreeBSD__) || defined(__OpenBSD__)
+#warning OS does not allow IPv6 address sharing
 			if (!gateway_unspec || rt->rt_dest.sa_family!=AF_INET6)
 #endif
 			rtm->rtm_addrs |= RTA_IFP;