split code into forwarding engine and connection manager

Change-Id: I3a3485e00e885c1f587907fd17e7b2e95e55c21d
diff --git a/shortcut-fe/sfe_cm.c b/shortcut-fe/sfe_cm.c
new file mode 100644
index 0000000..0600d99
--- /dev/null
+++ b/shortcut-fe/sfe_cm.c
@@ -0,0 +1,795 @@
+/*
+ * sfe-cm.c
+ *	Shortcut forwarding engine connection manager.
+ *
+ * XXX - fill in the appropriate GPL notice.
+ */
+#include <linux/module.h>
+#include <linux/sysfs.h>
+#include <linux/skbuff.h>
+#include <net/route.h>
+#include <linux/inetdevice.h>
+#include <linux/netfilter_bridge.h>
+#include <net/netfilter/nf_conntrack_acct.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_zones.h>
+#include <net/netfilter/nf_conntrack_core.h>
+
+#include "sfe.h"
+#include "sfe_ipv4.h"
+
+/*
+ * Per-module structure.
+ */
+struct sfe_cm {
+	spinlock_t lock;		/* Lock for SMP correctness */
+
+	/*
+	 * Control state.
+	 */
+	struct kobject *sys_sfe_cm;	/* sysfs linkage */
+
+	/*
+	 * Callback notifiers.
+	 */
+	struct notifier_block dev_notifier;
+					/* Device notifier */
+	struct notifier_block inet_notifier;
+					/* IP notifier */
+};
+
+struct sfe_cm __sc;
+
+/*
+ * Expose the hook for the receive processing.
+ */
+extern int (*athrs_fast_nat_recv)(struct sk_buff *skb);
+
+/*
+ * Expose what should be a static flag in the TCP connection tracker.
+ */
+extern int nf_ct_tcp_no_window_check;
+
+/*
+ * sfe_cm_recv()
+ *	Handle packet receives.
+ *
+ * Returns 1 if the packet is forwarded or 0 if it isn't.
+ */
+int sfe_cm_recv(struct sk_buff *skb)
+{
+	struct net_device *dev;
+#if (SFE_HOOK_ABOVE_BRIDGE)
+	struct in_device *in_dev;
+#endif
+
+	/*
+	 * We know that for the vast majority of packets we need the transport
+	 * layer header so we may as well start to fetch it now!
+	 */
+	prefetch(skb->data + 32);
+	barrier();
+
+	dev = skb->dev;
+
+#if (SFE_HOOK_ABOVE_BRIDGE)
+	/*
+	 * Does our input device support IP processing?
+	 */
+	in_dev = (struct in_device *)dev->ip_ptr;
+	if (unlikely(!in_dev)) {
+		DEBUG_TRACE("no IP processing for device: %s\n", dev->name);
+		return 0;
+	}
+
+	/*
+	 * Does it have an IP address?  If it doesn't then we can't do anything
+	 * interesting here!
+	 */
+	if (unlikely(!in_dev->ifa_list)) {
+		DEBUG_TRACE("no IP address for device: %s\n", dev->name);
+		return 0;
+	}
+#endif
+
+	/*
+	 * We're only interested in IP packets.
+	 */	
+	if (likely(htons(ETH_P_IP) == skb->protocol)) {
+		return sfe_ipv4_recv(dev, skb);
+	}
+
+	DEBUG_TRACE("not IP packet\n");
+	return 0;
+}
+
+/*
+ * sfe_cm_find_mac_addr()
+ *	Find the MAC address for a given IPv4 address.
+ *
+ * Returns true if we find the MAC address, otherwise false.
+ *
+ * We look up the rtable entry for the address and, from its neighbour
+ * structure, obtain the hardware address.  This means this function also
+ * works if the neighbours are routers too.
+ */
+static bool sfe_cm_find_mac_addr(uint32_t addr, uint8_t *mac_addr)
+{
+	struct neighbour *neigh;
+	struct rtable *rt;
+	struct dst_entry *dst;
+	struct net_device *dev;
+
+	/*
+	 * Look up the rtable entry for the IP address then get the hardware
+	 * address from its neighbour structure.  This means this work when the
+	 * neighbours are routers too.
+	 */
+	rt = ip_route_output(&init_net, addr, 0, 0, 0);
+	if (unlikely(IS_ERR(rt))) {
+		return false;
+	}
+
+	dst = (struct dst_entry *)rt;
+
+	rcu_read_lock();
+	neigh = dst_get_neighbour_noref(dst);
+	if (unlikely(!neigh)) {
+		rcu_read_unlock();
+		dst_release(dst);
+		return false; 
+	}
+
+	if (unlikely(!(neigh->nud_state & NUD_VALID))) {
+		rcu_read_unlock();
+		dst_release(dst);
+		return false;
+	}
+
+	dev = neigh->dev;
+	if (!dev) {
+		rcu_read_unlock();
+		dst_release(dst);
+		return false;
+	}
+
+	memcpy(mac_addr, neigh->ha, (size_t)dev->addr_len);
+	rcu_read_unlock();
+
+	dst_release(dst);
+
+	/*
+	 * We're only interested in unicast MAC addresses - if it's not a unicast
+	 * address then our IP address mustn't be unicast either.
+	 */
+	if (is_multicast_ether_addr(mac_addr)) {
+		DEBUG_TRACE("MAC is non-unicast - ignoring\n");
+		return false;
+	}
+
+	return true;
+}
+
+/*
+ * sfe_cm_ipv4_post_routing_hook()
+ *	Called for packets about to leave the box - either locally generated or forwarded from another interface
+ */
+static unsigned int sfe_cm_ipv4_post_routing_hook(unsigned int hooknum,
+						  struct sk_buff *skb,
+						  const struct net_device *in_unused,
+						  const struct net_device *out,
+						  int (*okfn)(struct sk_buff *))
+{
+	struct sfe_ipv4_create sic;
+	struct net_device *in;
+	struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	struct net_device *src_dev;
+	struct net_device *dest_dev;
+	struct net_device *src_br_dev = NULL;
+	struct net_device *dest_br_dev = NULL;
+	struct nf_conntrack_tuple orig_tuple;
+	struct nf_conntrack_tuple reply_tuple;
+
+	/*
+	 * Don't process broadcast or multicast packets.
+	 */
+	if (unlikely(skb->pkt_type == PACKET_BROADCAST)) {
+		DEBUG_TRACE("broadcast, ignoring\n");
+		return NF_ACCEPT;
+	}
+	if (unlikely(skb->pkt_type == PACKET_MULTICAST)) {
+		DEBUG_TRACE("multicast, ignoring\n");
+		return NF_ACCEPT;
+	}
+
+	/*
+	 * Don't process packets that are not being forwarded.
+	 */
+	in = dev_get_by_index(&init_net, skb->skb_iif);
+	if  (!in) {
+		DEBUG_TRACE("packet not forwarding\n");
+		return NF_ACCEPT;
+	}
+
+	/*
+	 * Don't process packets with non-standard 802.3 MAC address sizes.
+	 */
+	if (unlikely(in->addr_len != ETH_ALEN)) {
+		DEBUG_TRACE("in device: %s not 802.3 hw addr len: %u, ignoring\n",
+				in->name, (unsigned)in->addr_len);
+		goto done1;
+	}
+	if (unlikely(out->addr_len != ETH_ALEN)) {
+		DEBUG_TRACE("out device: %s not 802.3 hw addr len: %u, ignoring\n",
+				out->name, (unsigned)out->addr_len);
+		goto done1;
+	}
+
+	/*
+	 * Don't process packets that aren't being tracked by conntrack.
+	 */
+	ct = nf_ct_get(skb, &ctinfo);
+	if (unlikely(!ct)) {
+		DEBUG_TRACE("no conntrack connection, ignoring\n");
+		goto done1;
+	}
+
+	/*
+	 * Don't process untracked connections.
+	 */
+	if (unlikely(ct == &nf_conntrack_untracked)) {
+		DEBUG_TRACE("untracked connection\n");
+		goto done1;
+	}
+
+	/*
+	 * Don't process connections that require support from a 'helper' (typically a NAT ALG).
+	 */
+	if (unlikely(nfct_help(ct))) {
+		DEBUG_TRACE("connection has helper\n");
+		goto done1;
+	}
+
+	/*
+	 * Look up the details of our connection in conntrack.
+	 *
+	 * Note that the data we get from conntrack is for the "ORIGINAL" direction
+	 * but our packet may actually be in the "REPLY" direction.
+	 */
+	orig_tuple = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
+	reply_tuple = ct->tuplehash[IP_CT_DIR_REPLY].tuple;
+	sic.protocol = (int32_t)orig_tuple.dst.protonum;
+
+	/*
+	 * Get addressing information, non-NAT first
+	 */
+	sic.src_ip = (__be32)orig_tuple.src.u3.ip;
+	sic.dest_ip = (__be32)orig_tuple.dst.u3.ip;
+
+	/*
+	 * NAT'ed addresses - note these are as seen from the 'reply' direction
+	 * When NAT does not apply to this connection these will be identical to the above.
+	 */
+	sic.src_ip_xlate = (__be32)reply_tuple.dst.u3.ip;
+	sic.dest_ip_xlate = (__be32)reply_tuple.src.u3.ip;
+
+	sic.flags = 0;
+
+	switch (sic.protocol) {
+	case IPPROTO_TCP:
+		sic.src_port = orig_tuple.src.u.tcp.port;
+		sic.dest_port = orig_tuple.dst.u.tcp.port;
+		sic.src_port_xlate = reply_tuple.dst.u.tcp.port;
+		sic.dest_port_xlate = reply_tuple.src.u.tcp.port;
+		sic.src_td_window_scale = ct->proto.tcp.seen[0].td_scale;
+		sic.src_td_max_window = ct->proto.tcp.seen[0].td_maxwin;
+		sic.src_td_end = ct->proto.tcp.seen[0].td_end;
+		sic.src_td_max_end = ct->proto.tcp.seen[0].td_maxend;
+		sic.dest_td_window_scale = ct->proto.tcp.seen[1].td_scale;
+		sic.dest_td_max_window = ct->proto.tcp.seen[1].td_maxwin;
+		sic.dest_td_end = ct->proto.tcp.seen[1].td_end;
+		sic.dest_td_max_end = ct->proto.tcp.seen[1].td_maxend;
+		if (nf_ct_tcp_no_window_check
+		    || (ct->proto.tcp.seen[0].flags & IP_CT_TCP_FLAG_BE_LIBERAL)
+		    || (ct->proto.tcp.seen[1].flags & IP_CT_TCP_FLAG_BE_LIBERAL)) {
+			sic.flags |= SFE_IPV4_CREATE_FLAG_NO_SEQ_CHECK;
+		}
+
+		/*
+		 * Don't try to manage a non-established connection.
+		 */
+		if (!test_bit(IPS_ASSURED_BIT, &ct->status)) {
+			DEBUG_TRACE("non-established connection\n");
+			goto done1;
+		}
+
+		/*
+		 * If the connection is shutting down do not manage it.
+		 * state can not be SYN_SENT, SYN_RECV because connection is assured
+		 * Not managed states: FIN_WAIT, CLOSE_WAIT, LAST_ACK, TIME_WAIT, CLOSE.
+		 */
+		spin_lock_bh(&ct->lock);
+		if (ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED) {
+			spin_unlock_bh(&ct->lock);
+			DEBUG_TRACE("connection in termination state: %#x, s: %pI4:%u, d: %pI4:%u\n",
+				    ct->proto.tcp.state, &sic.src_ip, ntohs(sic.src_port),
+				    &sic.dest_ip, ntohs(sic.dest_port));
+			goto done1;
+		}
+		spin_unlock_bh(&ct->lock);
+		break;
+
+	case IPPROTO_UDP:
+		sic.src_port = orig_tuple.src.u.udp.port;
+		sic.dest_port = orig_tuple.dst.u.udp.port;
+		sic.src_port_xlate = reply_tuple.dst.u.udp.port;
+		sic.dest_port_xlate = reply_tuple.src.u.udp.port;
+		break;
+
+	default:
+		DEBUG_TRACE("unhandled protocol %d\n", sic.protocol);
+		goto done1;
+	}
+
+	/*
+	 * Get the MAC addresses that correspond to source and destination host addresses.
+	 */
+	if (!sfe_cm_find_mac_addr(sic.src_ip, sic.src_mac)) {
+		DEBUG_TRACE("failed to find MAC address for src IP: %pI4\n", &sic.src_ip);
+		goto done1;
+	}
+
+	if (!sfe_cm_find_mac_addr(sic.src_ip_xlate, sic.src_mac_xlate)) {
+		DEBUG_TRACE("failed to find MAC address for xlate src IP: %pI4\n", &sic.src_ip_xlate);
+		goto done1;
+	}
+
+	/*
+	 * Do dest now
+	 */
+	if (!sfe_cm_find_mac_addr(sic.dest_ip, sic.dest_mac)) {
+		DEBUG_TRACE("failed to find MAC address for dest IP: %pI4\n", &sic.dest_ip);
+		goto done1;
+	}
+
+	if (!sfe_cm_find_mac_addr(sic.dest_ip_xlate, sic.dest_mac_xlate)) {
+		DEBUG_TRACE("failed to find MAC address for xlate dest IP: %pI4\n", &sic.dest_ip_xlate);
+		goto done1;
+	}
+
+	/*
+	 * Get our device info.  If we're dealing with the "reply" direction here then
+	 * we'll need things swapped around.
+	 */
+	if (ctinfo < IP_CT_IS_REPLY) {
+		src_dev = in;
+		dest_dev = (struct net_device *)out;
+	} else {
+		src_dev = (struct net_device *)out;
+		dest_dev = in;
+	}
+
+#if (!SFE_HOOK_ABOVE_BRIDGE)
+	/*
+	 * Now our devices may actually be a bridge interface.  If that's
+	 * the case then we need to hunt down the underlying interface.
+	 */
+	if (src_dev->priv_flags & IFF_EBRIDGE) {
+		src_br_dev = br_port_dev_get(src_dev, sic.src_mac);
+		if (!src_br_dev) {
+			DEBUG_TRACE("no port found on bridge\n");
+			goto done1;
+		}
+
+		src_dev = src_br_dev;
+	}
+
+	if (dest_dev->priv_flags & IFF_EBRIDGE) {
+		dest_br_dev = br_port_dev_get(dest_dev, sic.dest_mac_xlate);
+		if (!dest_br_dev) {
+			DEBUG_TRACE("no port found on bridge\n");
+			goto done2;
+		}
+
+		dest_dev = dest_br_dev;
+	}
+#else
+	/*
+	 * Our devices may actually be part of a bridge interface.  If that's
+	 * the case then find the bridge interface instead.
+	 */
+	if (src_dev->priv_flags & IFF_BRIDGE_PORT) {
+		src_br_dev = src_dev->master;
+		if (!src_br_dev) {
+			DEBUG_TRACE("no bridge found for: %s\n", src_dev->name);
+			goto done1;
+		}
+
+		dev_hold(src_br_dev);
+		src_dev = src_br_dev;
+	}
+
+	if (dest_dev->priv_flags & IFF_BRIDGE_PORT) {
+		dest_br_dev = dest_dev->master;
+		if (!dest_br_dev) {
+			DEBUG_TRACE("no bridge found for: %s\n", dest_dev->name);
+			goto done2;
+		}
+
+		dev_hold(dest_br_dev);
+		dest_dev = dest_br_dev;
+	}
+#endif
+
+	sic.src_dev = src_dev;
+	sic.dest_dev = dest_dev;
+
+// XXX - these MTUs need handling correctly!
+	sic.src_mtu = 1500;
+	sic.dest_mtu = 1500;
+
+	sfe_ipv4_create_rule(&sic);
+
+	/*
+	 * If we had bridge ports then release them too.
+	 */
+	if (dest_br_dev) {
+		dev_put(dest_br_dev);
+	}
+
+done2:
+	if (src_br_dev) {
+		dev_put(src_br_dev);
+	}
+
+done1:
+	/*
+	 * Release the interface on which this skb arrived
+	 */
+	dev_put(in);
+
+	return NF_ACCEPT;
+}
+
+#ifdef CONFIG_NF_CONNTRACK_EVENTS
+/*
+ * sfe_cm_conntrack_event()
+ *	Callback event invoked when a conntrack connection's state changes.
+ */
+static int sfe_cm_conntrack_event(unsigned int events, struct nf_ct_event *item)
+{
+	struct sfe_ipv4_destroy sid;
+	struct nf_conn *ct = item->ct;
+	struct nf_conntrack_tuple orig_tuple;
+
+	/*
+	 * If we don't have a conntrack entry then we're done.
+	 */
+	if (unlikely(!ct)) {
+		DEBUG_WARN("no ct in conntrack event callback\n");
+		return NOTIFY_DONE;
+	}
+
+	/*
+	 * If this is an untracked connection then we can't have any state either.
+	 */
+	if (unlikely(ct == &nf_conntrack_untracked)) {
+		DEBUG_TRACE("ignoring untracked conn\n");
+		return NOTIFY_DONE;
+	}
+
+	/*
+	 * Ignore anything other than IPv4 connections.
+	 */
+	if (unlikely(nf_ct_l3num(ct) != AF_INET)) {
+		DEBUG_TRACE("ignoring non-IPv4 conn\n");
+		return NOTIFY_DONE;
+	}
+
+	/*
+	 * We're only interested in destroy events.
+	 */
+	if (unlikely(!(events & (1 << IPCT_DESTROY)))) {
+		DEBUG_TRACE("ignoring non-destroy event\n");
+		return NOTIFY_DONE;
+	}
+
+	orig_tuple = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
+	sid.protocol = (int32_t)orig_tuple.dst.protonum;
+
+	/*
+	 * Extract information from the conntrack connection.  We're only interested
+	 * in nominal connection information (i.e. we're ignoring any NAT information).
+	 */
+	sid.src_ip = (__be32)orig_tuple.src.u3.ip;
+	sid.dest_ip = (__be32)orig_tuple.dst.u3.ip;
+
+	switch (sid.protocol) {
+	case IPPROTO_TCP:
+		sid.src_port = orig_tuple.src.u.tcp.port;
+		sid.dest_port = orig_tuple.dst.u.tcp.port;
+		break;
+
+	case IPPROTO_UDP:
+		sid.src_port = orig_tuple.src.u.udp.port;
+		sid.dest_port = orig_tuple.dst.u.udp.port;
+		break;
+
+	default:
+		DEBUG_TRACE("unhandled protocol: %d\n", sid.protocol);
+		return NOTIFY_DONE;
+	}
+
+
+	sfe_ipv4_destroy_rule(&sid);
+	return NOTIFY_DONE;
+}
+
+/*
+ * Netfilter conntrack event system to monitor connection tracking changes
+ */
+static struct nf_ct_event_notifier sfe_cm_conntrack_notifier = {
+	.fcn = sfe_cm_conntrack_event,
+};
+#endif
+
+/*
+ * Structure to establish a hook into the post routing netfilter point - this
+ * will pick up local outbound and packets going from one interface to another.
+ *
+ * Note: see include/linux/netfilter_ipv4.h for info related to priority levels.
+ * We want to examine packets after NAT translation and any ALG processing.
+ */
+static struct nf_hook_ops sfe_cm_ipv4_ops_post_routing[] __read_mostly = {
+	{
+		.hook = sfe_cm_ipv4_post_routing_hook,
+		.owner = THIS_MODULE,
+		.pf = PF_INET,
+		.hooknum = NF_INET_POST_ROUTING,
+		.priority = NF_IP_PRI_NAT_SRC + 1,
+	},
+};
+
+/*
+ * sfe_cm_sync_rule()
+ *	Synchronize a connection's state.
+ */
+static void sfe_cm_sync_rule(struct sfe_ipv4_sync *sis)
+{
+	struct nf_conntrack_tuple_hash *h;
+	struct nf_conntrack_tuple tuple;
+	struct nf_conn *ct;
+	struct nf_conn_counter *acct;
+
+	/*
+	 * Create a tuple so as to be able to look up a connection
+	 */
+	memset(&tuple, 0, sizeof(tuple));
+	tuple.src.u3.ip = sis->src_ip;
+	tuple.src.u.all = (__be16)sis->src_port;
+	tuple.src.l3num = AF_INET;
+
+	tuple.dst.u3.ip = sis->dest_ip;
+	tuple.dst.dir = IP_CT_DIR_ORIGINAL;
+	tuple.dst.protonum = (uint8_t)sis->protocol;
+	tuple.dst.u.all = (__be16)sis->dest_port;
+
+	DEBUG_TRACE("update connection - p: %d, s: %pI4:%u, d: %pI4:%u\n",
+		    (int)tuple.dst.protonum,
+		    &tuple.src.u3.ip, (unsigned int)ntohs(tuple.src.u.all),
+		    &tuple.dst.u3.ip, (unsigned int)ntohs(tuple.dst.u.all));
+
+	/*
+	 * Look up conntrack connection
+	 */
+	h = nf_conntrack_find_get(&init_net, NF_CT_DEFAULT_ZONE, &tuple);
+	if (unlikely(!h)) {
+		DEBUG_TRACE("no connection found\n");
+		return;
+	}
+
+	ct = nf_ct_tuplehash_to_ctrack(h);
+	NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
+
+	/*
+	 * Only update if this is not a fixed timeout
+	 */
+	if (!test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) {
+		ct->timeout.expires += sis->delta_jiffies;
+	}
+
+	acct = nf_conn_acct_find(ct);
+	if (acct) {
+		spin_lock_bh(&ct->lock);
+		atomic64_add(sis->src_packet_count, &acct[IP_CT_DIR_ORIGINAL].packets);
+		atomic64_add(sis->src_byte_count, &acct[IP_CT_DIR_ORIGINAL].bytes);
+		atomic64_add(sis->dest_packet_count, &acct[IP_CT_DIR_REPLY].packets);
+		atomic64_add(sis->dest_byte_count, &acct[IP_CT_DIR_REPLY].bytes);
+		spin_unlock_bh(&ct->lock);
+	}
+
+	switch (sis->protocol) {
+	case IPPROTO_TCP:
+		spin_lock_bh(&ct->lock);
+		if (ct->proto.tcp.seen[0].td_maxwin < sis->src_td_max_window) {
+			ct->proto.tcp.seen[0].td_maxwin = sis->src_td_max_window;
+		}
+		if ((int32_t)(ct->proto.tcp.seen[0].td_end - sis->src_td_end) < 0) {
+			ct->proto.tcp.seen[0].td_end = sis->src_td_end;
+		}
+		if ((int32_t)(ct->proto.tcp.seen[0].td_maxend - sis->src_td_max_end) < 0) {
+			ct->proto.tcp.seen[0].td_maxend = sis->src_td_max_end;
+		}
+		if (ct->proto.tcp.seen[1].td_maxwin < sis->dest_td_max_window) {
+			ct->proto.tcp.seen[1].td_maxwin = sis->dest_td_max_window;
+		}
+		if ((int32_t)(ct->proto.tcp.seen[1].td_end - sis->dest_td_end) < 0) {
+			ct->proto.tcp.seen[1].td_end = sis->dest_td_end;
+		}
+		if ((int32_t)(ct->proto.tcp.seen[1].td_maxend - sis->dest_td_max_end) < 0) {
+			ct->proto.tcp.seen[1].td_maxend = sis->dest_td_max_end;
+		}
+		spin_unlock_bh(&ct->lock);
+		break;
+	}
+
+	/*
+	 * Release connection
+	 */
+	nf_ct_put(ct);
+}
+
+/*
+ * sfe_cm_device_event()
+ */
+static int sfe_cm_device_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct net_device *dev = (struct net_device *)ptr;
+
+	switch (event) {
+	case NETDEV_DOWN:
+		if (dev) {
+			sfe_ipv4_destroy_all_rules_for_dev(dev);
+		}
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+/*
+ * sfe_cm_inet_event()
+ */
+static int sfe_cm_inet_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct net_device *dev = ((struct in_ifaddr *)ptr)->ifa_dev->dev;
+	return sfe_cm_device_event(this, event, dev);
+}
+
+/*
+ * sfe_cm_init()
+ */
+static int __init sfe_cm_init(void)
+{
+	struct sfe_cm *sc = &__sc;
+	int result = -1;
+
+	DEBUG_INFO("SFE CM init\n");
+
+	/*
+	 * Create sys/sfe_cm
+	 */
+	sc->sys_sfe_cm = kobject_create_and_add("sfe_cm", NULL);
+	if (!sc->sys_sfe_cm) {
+		DEBUG_ERROR("failed to register sfe_cm\n");
+		goto exit1;
+	}
+
+	sc->dev_notifier.notifier_call = sfe_cm_device_event;
+	sc->dev_notifier.priority = 1;
+	register_netdevice_notifier(&sc->dev_notifier);
+
+	sc->inet_notifier.notifier_call = sfe_cm_inet_event;
+	sc->inet_notifier.priority = 1;
+	register_inetaddr_notifier(&sc->inet_notifier);
+
+	/*
+	 * Register our netfilter hooks.
+	 */
+	result = nf_register_hooks(sfe_cm_ipv4_ops_post_routing, ARRAY_SIZE(sfe_cm_ipv4_ops_post_routing));
+	if (result < 0) {
+		DEBUG_ERROR("can't register nf post routing hook: %d\n", result);
+		goto exit6;
+	}
+
+#ifdef CONFIG_NF_CONNTRACK_EVENTS
+	/*
+	 * Register a notifier hook to get fast notifications of expired connections.
+	 */
+	result = nf_conntrack_register_notifier(&init_net, &sfe_cm_conntrack_notifier);
+	if (result < 0) {
+		DEBUG_ERROR("can't register nf notifier hook: %d\n", result);
+		goto exit7;
+	}
+#endif
+
+	spin_lock_init(&sc->lock);
+
+	/*
+	 * Hook the receive path in the network stack.
+	 */
+	BUG_ON(athrs_fast_nat_recv != NULL);
+	RCU_INIT_POINTER(athrs_fast_nat_recv, sfe_cm_recv);
+
+	/*
+	 * Hook the shortcut sync callback.
+	 */
+	sfe_ipv4_register_sync_rule_callback(sfe_cm_sync_rule);
+	return 0;
+
+#ifdef CONFIG_NF_CONNTRACK_EVENTS
+exit7:
+#endif
+	nf_unregister_hooks(sfe_cm_ipv4_ops_post_routing, ARRAY_SIZE(sfe_cm_ipv4_ops_post_routing));
+
+exit6:
+	unregister_inetaddr_notifier(&sc->inet_notifier);
+	unregister_netdevice_notifier(&sc->dev_notifier);
+	kobject_put(sc->sys_sfe_cm);
+
+exit1:
+	return result;
+}
+
+/*
+ * sfe_cm_exit()
+ */
+static void __exit sfe_cm_exit(void)
+{
+	struct sfe_cm *sc = &__sc;
+
+	DEBUG_INFO("SFE CM exit\n");
+
+	/*
+	 * Unregister our sync callback.
+	 */
+	sfe_ipv4_register_sync_rule_callback(NULL);
+
+	/*
+	 * Unregister our receive callback.
+	 */
+	RCU_INIT_POINTER(athrs_fast_nat_recv, NULL);
+
+	/*
+	 * Wait for all callbacks to complete.
+	 */
+	rcu_barrier();
+
+	/*
+	 * Destroy all connections.
+	 */
+	sfe_ipv4_destroy_all_rules_for_dev(NULL);
+
+// XXX - this is where we need to unregister with any lower level offload services.
+
+#ifdef CONFIG_NF_CONNTRACK_EVENTS
+	nf_conntrack_unregister_notifier(&init_net, &sfe_cm_conntrack_notifier);
+
+#endif
+	nf_unregister_hooks(sfe_cm_ipv4_ops_post_routing, ARRAY_SIZE(sfe_cm_ipv4_ops_post_routing));
+
+	unregister_inetaddr_notifier(&sc->inet_notifier);
+	unregister_netdevice_notifier(&sc->dev_notifier);
+
+	kobject_put(sc->sys_sfe_cm);
+
+}
+
+module_init(sfe_cm_init)
+module_exit(sfe_cm_exit)
+
+MODULE_AUTHOR("Qualcomm Atheros Inc.");
+MODULE_DESCRIPTION("Shortcut Forwarding Engine - Connection Manager");
+MODULE_LICENSE("GPL");
+