zebra: NetBSD: support setting IPSRCSEL preference

add 'ip address X preference Y' vty command and appropriate
infrastructure for setting it through ioctl(SIOCSIFADDRPREF).

IPSRCSEL is a NetBSD kernel option(4), documented in in_getifa(9) and
is available since NetBSD 4.0 but not enabled in default GENERIC.

1 files changed, 17 insertions, 0 deletions

diff --git a/zebra/ioctl.c b/zebra/ioctl.c
index 8eb2d93c..6cb428a7 100644
--- a/zebra/ioctl.c
+++ b/zebra/ioctl.c
@@ -238,6 +238,23 @@ if_set_prefix (struct interface *ifp, struct connected *ifc)
   ret = if_ioctl (SIOCAIFADDR, (caddr_t) &addreq);
   if (ret < 0)
     return ret;
+
+#ifdef SIOCSIFADDRPREF
+  if (ifc->preference != 0)
+    {
+      struct if_addrprefreq ifapr;
+
+      memset (&ifapr, 0, sizeof ifapr);
+      strncpy ((char *)&ifapr.ifap_name, ifp->name, sizeof ifapr.ifap_name);
+      ifapr.ifap_preference = ifc->preference;
+      memcpy (&ifapr.ifap_addr, &addr, sizeof (struct sockaddr_in));
+
+      ret = if_ioctl (SIOCSIFADDRPREF, (caddr_t) &ifapr);
+      if (ret < 0)
+        zlog_err("if_ioctl(SIOCSIFADDRPREF) failed: %s",
+		 safe_strerror(errno));
+    }
+#endif
   return 0;
 }