Add the trunk(4) driver for providing link aggregation, failover and fault

tolerance.  This driver allows aggregation of multiple network interfaces as
one virtual interface using a number of different protocols/algorithms.

failover    - Sends traffic through the secondary port if the master becomes
              inactive.
fec         - Supports Cisco Fast EtherChannel.
lacp        - Supports the IEEE 802.3ad Link Aggregation Control Protocol
              (LACP) and the Marker Protocol.
loadbalance - Static loadbalancing using an outgoing hash.
roundrobin  - Distributes outgoing traffic using a round-robin scheduler
              through all active ports.

This code was obtained from OpenBSD and this also includes 802.3ad LACP support
from agr(4) in NetBSD.

1 files changed, 14 insertions, 0 deletions

diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 3c9cc8e769af..0ebdc569bc4f 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -113,6 +113,9 @@ int	(*bridge_output_p)(struct ifnet *, struct mbuf *,
 		struct sockaddr *, struct rtentry *);
 void	(*bridge_dn_p)(struct mbuf *, struct ifnet *);
 
+/* if_trunk(4) support */
+struct mbuf *(*trunk_input_p)(struct ifnet *, struct mbuf *); 
+
 static const u_char etherbroadcastaddr[ETHER_ADDR_LEN] =
 			{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 
@@ -602,6 +605,17 @@ ether_input(struct ifnet *ifp, struct mbuf *m)
 		return;
 	}
 
+	/* Handle input from a trunk(4) port */
+	if (ifp->if_type == IFT_IEEE8023ADLAG) {
+		KASSERT(trunk_input_p != NULL,
+		    ("%s: if_trunk not loaded!", __func__));
+		m = (*trunk_input_p)(ifp, m);
+		if (m != NULL)
+			ifp = m->m_pkthdr.rcvif;
+		else 
+			return;
+	}
+
 	/*
 	 * If the hardware did not process an 802.1Q tag, do this now,
 	 * to allow 802.1P priority frames to be passed to the main input