Merge helper fib* functions used for basic lookups.

Vast majority of rtalloc(9) users require only basic info from
route table (e.g. "does the rtentry interface match with the interface
  I have?". "what is the MTU?", "Give me the IPv4 source address to use",
  etc..).
Instead of hand-rolling lookups, checking if rtentry is up, valid,
  dealing with IPv6 mtu, finding "address" ifp (almost never done right),
  provide easy-to-use API hiding all the complexity and returning the
  needed info into small on-stack structure.

This change also helps hiding route subsystem internals (locking, direct
  rtentry accesses).
Additionaly, using this API improves lookup performance since rtentry is not
  locked.
(This is safe, since all the rtentry changes happens under both radix WLOCK
  and rtentry WLOCK).

Sponsored by:	Yandex LLC

1 files changed, 31 insertions, 0 deletions

diff --git a/sys/net/route.h b/sys/net/route.h
index ffbcb3c..c1d0997 100644
--- a/sys/net/route.h
+++ b/sys/net/route.h
@@ -171,6 +171,37 @@ struct rtentry {
 	 RTF_REJECT | RTF_STATIC | RTF_STICKY)
 
 /*
+ * fib_ nexthop API flags.
+ */
+
+/* Consumer-visible nexthop info flags */
+#define	NHF_REJECT		0x0010	/* RTF_REJECT */
+#define	NHF_BLACKHOLE		0x0020	/* RTF_BLACKHOLE */
+#define	NHF_REDIRECT		0x0040	/* RTF_DYNAMIC|RTF_MODIFIED */
+#define	NHF_DEFAULT		0x0080	/* Default route */
+#define	NHF_BROADCAST		0x0100	/* RTF_BROADCAST */
+#define	NHF_GATEWAY		0x0200	/* RTF_GATEWAY */
+
+/* Nexthop request flags */
+#define	NHR_IFAIF		0x01	/* Return ifa_ifp interface */
+#define	NHR_REF			0x02	/* For future use */
+
+/* rte<>nhop translation */
+static inline uint16_t
+fib_rte_to_nh_flags(int rt_flags)
+{
+	uint16_t res;
+
+	res = (rt_flags & RTF_REJECT) ? NHF_REJECT : 0;
+	res |= (rt_flags & RTF_BLACKHOLE) ? NHF_BLACKHOLE : 0;
+	res |= (rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) ? NHF_REDIRECT : 0;
+	res |= (rt_flags & RTF_BROADCAST) ? NHF_BROADCAST : 0;
+	res |= (rt_flags & RTF_GATEWAY) ? NHF_GATEWAY : 0;
+
+	return (res);
+}
+
+/*
  * Routing statistics.
  */
 struct	rtstat {