1 files changed, 870 insertions, 0 deletions

diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c
new file mode 100644
index 000000000000..c589a9ba506a
--- /dev/null
+++ b/net/sched/act_ife.c
@@ -0,0 +1,870 @@
+/*
+ * net/sched/ife.c	Inter-FE action based on ForCES WG InterFE LFB
+ *
+ *		Refer to:
+ *		draft-ietf-forces-interfelfb-03
+ *		and
+ *		netdev01 paper:
+ *		"Distributing Linux Traffic Control Classifier-Action
+ *		Subsystem"
+ *		Authors: Jamal Hadi Salim and Damascene M. Joachimpillai
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ * copyright Jamal Hadi Salim (2015)
+ *
+*/
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <net/net_namespace.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <uapi/linux/tc_act/tc_ife.h>
+#include <net/tc_act/tc_ife.h>
+#include <linux/etherdevice.h>
+
+#define IFE_TAB_MASK 15
+
+static int ife_net_id;
+static int max_metacnt = IFE_META_MAX + 1;
+
+static const struct nla_policy ife_policy[TCA_IFE_MAX + 1] = {
+	[TCA_IFE_PARMS] = { .len = sizeof(struct tc_ife)},
+	[TCA_IFE_DMAC] = { .len = ETH_ALEN},
+	[TCA_IFE_SMAC] = { .len = ETH_ALEN},
+	[TCA_IFE_TYPE] = { .type = NLA_U16},
+};
+
+/* Caller takes care of presenting data in network order
+*/
+int ife_tlv_meta_encode(void *skbdata, u16 attrtype, u16 dlen, const void *dval)
+{
+	u32 *tlv = (u32 *)(skbdata);
+	u16 totlen = nla_total_size(dlen);	/*alignment + hdr */
+	char *dptr = (char *)tlv + NLA_HDRLEN;
+	u32 htlv = attrtype << 16 | totlen;
+
+	*tlv = htonl(htlv);
+	memset(dptr, 0, totlen - NLA_HDRLEN);
+	memcpy(dptr, dval, dlen);
+
+	return totlen;
+}
+EXPORT_SYMBOL_GPL(ife_tlv_meta_encode);
+
+int ife_get_meta_u32(struct sk_buff *skb, struct tcf_meta_info *mi)
+{
+	if (mi->metaval)
+		return nla_put_u32(skb, mi->metaid, *(u32 *)mi->metaval);
+	else
+		return nla_put(skb, mi->metaid, 0, NULL);
+}
+EXPORT_SYMBOL_GPL(ife_get_meta_u32);
+
+int ife_check_meta_u32(u32 metaval, struct tcf_meta_info *mi)
+{
+	if (metaval || mi->metaval)
+		return 8; /* T+L+V == 2+2+4 */
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ife_check_meta_u32);
+
+int ife_encode_meta_u32(u32 metaval, void *skbdata, struct tcf_meta_info *mi)
+{
+	u32 edata = metaval;
+
+	if (mi->metaval)
+		edata = *(u32 *)mi->metaval;
+	else if (metaval)
+		edata = metaval;
+
+	if (!edata) /* will not encode */
+		return 0;
+
+	edata = htonl(edata);
+	return ife_tlv_meta_encode(skbdata, mi->metaid, 4, &edata);
+}
+EXPORT_SYMBOL_GPL(ife_encode_meta_u32);
+
+int ife_get_meta_u16(struct sk_buff *skb, struct tcf_meta_info *mi)
+{
+	if (mi->metaval)
+		return nla_put_u16(skb, mi->metaid, *(u16 *)mi->metaval);
+	else
+		return nla_put(skb, mi->metaid, 0, NULL);
+}
+EXPORT_SYMBOL_GPL(ife_get_meta_u16);
+
+int ife_alloc_meta_u32(struct tcf_meta_info *mi, void *metaval)
+{
+	mi->metaval = kmemdup(metaval, sizeof(u32), GFP_KERNEL);
+	if (!mi->metaval)
+		return -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ife_alloc_meta_u32);
+
+int ife_alloc_meta_u16(struct tcf_meta_info *mi, void *metaval)
+{
+	mi->metaval = kmemdup(metaval, sizeof(u16), GFP_KERNEL);
+	if (!mi->metaval)
+		return -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ife_alloc_meta_u16);
+
+void ife_release_meta_gen(struct tcf_meta_info *mi)
+{
+	kfree(mi->metaval);
+}
+EXPORT_SYMBOL_GPL(ife_release_meta_gen);
+
+int ife_validate_meta_u32(void *val, int len)
+{
+	if (len == 4)
+		return 0;
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(ife_validate_meta_u32);
+
+int ife_validate_meta_u16(void *val, int len)
+{
+	/* length will include padding */
+	if (len == NLA_ALIGN(2))
+		return 0;
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(ife_validate_meta_u16);
+
+static LIST_HEAD(ifeoplist);
+static DEFINE_RWLOCK(ife_mod_lock);
+
+static struct tcf_meta_ops *find_ife_oplist(u16 metaid)
+{
+	struct tcf_meta_ops *o;
+
+	read_lock(&ife_mod_lock);
+	list_for_each_entry(o, &ifeoplist, list) {
+		if (o->metaid == metaid) {
+			if (!try_module_get(o->owner))
+				o = NULL;
+			read_unlock(&ife_mod_lock);
+			return o;
+		}
+	}
+	read_unlock(&ife_mod_lock);
+
+	return NULL;
+}
+
+int register_ife_op(struct tcf_meta_ops *mops)
+{
+	struct tcf_meta_ops *m;
+
+	if (!mops->metaid || !mops->metatype || !mops->name ||
+	    !mops->check_presence || !mops->encode || !mops->decode ||
+	    !mops->get || !mops->alloc)
+		return -EINVAL;
+
+	write_lock(&ife_mod_lock);
+
+	list_for_each_entry(m, &ifeoplist, list) {
+		if (m->metaid == mops->metaid ||
+		    (strcmp(mops->name, m->name) == 0)) {
+			write_unlock(&ife_mod_lock);
+			return -EEXIST;
+		}
+	}
+
+	if (!mops->release)
+		mops->release = ife_release_meta_gen;
+
+	list_add_tail(&mops->list, &ifeoplist);
+	write_unlock(&ife_mod_lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(unregister_ife_op);
+
+int unregister_ife_op(struct tcf_meta_ops *mops)
+{
+	struct tcf_meta_ops *m;
+	int err = -ENOENT;
+
+	write_lock(&ife_mod_lock);
+	list_for_each_entry(m, &ifeoplist, list) {
+		if (m->metaid == mops->metaid) {
+			list_del(&mops->list);
+			err = 0;
+			break;
+		}
+	}
+	write_unlock(&ife_mod_lock);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(register_ife_op);
+
+static int ife_validate_metatype(struct tcf_meta_ops *ops, void *val, int len)
+{
+	int ret = 0;
+	/* XXX: unfortunately cant use nla_policy at this point
+	* because a length of 0 is valid in the case of
+	* "allow". "use" semantics do enforce for proper
+	* length and i couldve use nla_policy but it makes it hard
+	* to use it just for that..
+	*/
+	if (ops->validate)
+		return ops->validate(val, len);
+
+	if (ops->metatype == NLA_U32)
+		ret = ife_validate_meta_u32(val, len);
+	else if (ops->metatype == NLA_U16)
+		ret = ife_validate_meta_u16(val, len);
+
+	return ret;
+}
+
+/* called when adding new meta information
+ * under ife->tcf_lock
+*/
+static int load_metaops_and_vet(struct tcf_ife_info *ife, u32 metaid,
+				void *val, int len)
+{
+	struct tcf_meta_ops *ops = find_ife_oplist(metaid);
+	int ret = 0;
+
+	if (!ops) {
+		ret = -ENOENT;
+#ifdef CONFIG_MODULES
+		spin_unlock_bh(&ife->tcf_lock);
+		rtnl_unlock();
+		request_module("ifemeta%u", metaid);
+		rtnl_lock();
+		spin_lock_bh(&ife->tcf_lock);
+		ops = find_ife_oplist(metaid);
+#endif
+	}
+
+	if (ops) {
+		ret = 0;
+		if (len)
+			ret = ife_validate_metatype(ops, val, len);
+
+		module_put(ops->owner);
+	}
+
+	return ret;
+}
+
+/* called when adding new meta information
+ * under ife->tcf_lock
+*/
+static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
+			int len)
+{
+	struct tcf_meta_info *mi = NULL;
+	struct tcf_meta_ops *ops = find_ife_oplist(metaid);
+	int ret = 0;
+
+	if (!ops)
+		return -ENOENT;
+
+	mi = kzalloc(sizeof(*mi), GFP_KERNEL);
+	if (!mi) {
+		/*put back what find_ife_oplist took */
+		module_put(ops->owner);
+		return -ENOMEM;
+	}
+
+	mi->metaid = metaid;
+	mi->ops = ops;
+	if (len > 0) {
+		ret = ops->alloc(mi, metaval);
+		if (ret != 0) {
+			kfree(mi);
+			module_put(ops->owner);
+			return ret;
+		}
+	}
+
+	list_add_tail(&mi->metalist, &ife->metalist);
+
+	return ret;
+}
+
+static int use_all_metadata(struct tcf_ife_info *ife)
+{
+	struct tcf_meta_ops *o;
+	int rc = 0;
+	int installed = 0;
+
+	list_for_each_entry(o, &ifeoplist, list) {
+		rc = add_metainfo(ife, o->metaid, NULL, 0);
+		if (rc == 0)
+			installed += 1;
+	}
+
+	if (installed)
+		return 0;
+	else
+		return -EINVAL;
+}
+
+static int dump_metalist(struct sk_buff *skb, struct tcf_ife_info *ife)
+{
+	struct tcf_meta_info *e;
+	struct nlattr *nest;
+	unsigned char *b = skb_tail_pointer(skb);
+	int total_encoded = 0;
+
+	/*can only happen on decode */
+	if (list_empty(&ife->metalist))
+		return 0;
+
+	nest = nla_nest_start(skb, TCA_IFE_METALST);
+	if (!nest)
+		goto out_nlmsg_trim;
+
+	list_for_each_entry(e, &ife->metalist, metalist) {
+		if (!e->ops->get(skb, e))
+			total_encoded += 1;
+	}
+
+	if (!total_encoded)
+		goto out_nlmsg_trim;
+
+	nla_nest_end(skb, nest);
+
+	return 0;
+
+out_nlmsg_trim:
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+/* under ife->tcf_lock */
+static void _tcf_ife_cleanup(struct tc_action *a, int bind)
+{
+	struct tcf_ife_info *ife = a->priv;
+	struct tcf_meta_info *e, *n;
+
+	list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
+		module_put(e->ops->owner);
+		list_del(&e->metalist);
+		if (e->metaval) {
+			if (e->ops->release)
+				e->ops->release(e);
+			else
+				kfree(e->metaval);
+		}
+		kfree(e);
+	}
+}
+
+static void tcf_ife_cleanup(struct tc_action *a, int bind)
+{
+	struct tcf_ife_info *ife = a->priv;
+
+	spin_lock_bh(&ife->tcf_lock);
+	_tcf_ife_cleanup(a, bind);
+	spin_unlock_bh(&ife->tcf_lock);
+}
+
+/* under ife->tcf_lock */
+static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb)
+{
+	int len = 0;
+	int rc = 0;
+	int i = 0;
+	void *val;
+
+	for (i = 1; i < max_metacnt; i++) {
+		if (tb[i]) {
+			val = nla_data(tb[i]);
+			len = nla_len(tb[i]);
+
+			rc = load_metaops_and_vet(ife, i, val, len);
+			if (rc != 0)
+				return rc;
+
+			rc = add_metainfo(ife, i, val, len);
+			if (rc)
+				return rc;
+		}
+	}
+
+	return rc;
+}
+
+static int tcf_ife_init(struct net *net, struct nlattr *nla,
+			struct nlattr *est, struct tc_action *a,
+			int ovr, int bind)
+{
+	struct tc_action_net *tn = net_generic(net, ife_net_id);
+	struct nlattr *tb[TCA_IFE_MAX + 1];
+	struct nlattr *tb2[IFE_META_MAX + 1];
+	struct tcf_ife_info *ife;
+	struct tc_ife *parm;
+	u16 ife_type = 0;
+	u8 *daddr = NULL;
+	u8 *saddr = NULL;
+	int ret = 0;
+	int err;
+
+	err = nla_parse_nested(tb, TCA_IFE_MAX, nla, ife_policy);
+	if (err < 0)
+		return err;
+
+	if (!tb[TCA_IFE_PARMS])
+		return -EINVAL;
+
+	parm = nla_data(tb[TCA_IFE_PARMS]);
+
+	if (parm->flags & IFE_ENCODE) {
+		/* Until we get issued the ethertype, we cant have
+		 * a default..
+		**/
+		if (!tb[TCA_IFE_TYPE]) {
+			pr_info("You MUST pass etherype for encoding\n");
+			return -EINVAL;
+		}
+	}
+
+	if (!tcf_hash_check(tn, parm->index, a, bind)) {
+		ret = tcf_hash_create(tn, parm->index, est, a, sizeof(*ife),
+				      bind, false);
+		if (ret)
+			return ret;
+		ret = ACT_P_CREATED;
+	} else {
+		if (bind)	/* dont override defaults */
+			return 0;
+		tcf_hash_release(a, bind);
+		if (!ovr)
+			return -EEXIST;
+	}
+
+	ife = to_ife(a);
+	ife->flags = parm->flags;
+
+	if (parm->flags & IFE_ENCODE) {
+		ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
+		if (tb[TCA_IFE_DMAC])
+			daddr = nla_data(tb[TCA_IFE_DMAC]);
+		if (tb[TCA_IFE_SMAC])
+			saddr = nla_data(tb[TCA_IFE_SMAC]);
+	}
+
+	spin_lock_bh(&ife->tcf_lock);
+	ife->tcf_action = parm->action;
+
+	if (parm->flags & IFE_ENCODE) {
+		if (daddr)
+			ether_addr_copy(ife->eth_dst, daddr);
+		else
+			eth_zero_addr(ife->eth_dst);
+
+		if (saddr)
+			ether_addr_copy(ife->eth_src, saddr);
+		else
+			eth_zero_addr(ife->eth_src);
+
+		ife->eth_type = ife_type;
+	}
+
+	if (ret == ACT_P_CREATED)
+		INIT_LIST_HEAD(&ife->metalist);
+
+	if (tb[TCA_IFE_METALST]) {
+		err = nla_parse_nested(tb2, IFE_META_MAX, tb[TCA_IFE_METALST],
+				       NULL);
+		if (err) {
+metadata_parse_err:
+			if (ret == ACT_P_CREATED)
+				_tcf_ife_cleanup(a, bind);
+
+			spin_unlock_bh(&ife->tcf_lock);
+			return err;
+		}
+
+		err = populate_metalist(ife, tb2);
+		if (err)
+			goto metadata_parse_err;
+
+	} else {
+		/* if no passed metadata allow list or passed allow-all
+		 * then here we process by adding as many supported metadatum
+		 * as we can. You better have at least one else we are
+		 * going to bail out
+		 */
+		err = use_all_metadata(ife);
+		if (err) {
+			if (ret == ACT_P_CREATED)
+				_tcf_ife_cleanup(a, bind);
+
+			spin_unlock_bh(&ife->tcf_lock);
+			return err;
+		}
+	}
+
+	spin_unlock_bh(&ife->tcf_lock);
+
+	if (ret == ACT_P_CREATED)
+		tcf_hash_insert(tn, a);
+
+	return ret;
+}
+
+static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
+			int ref)
+{
+	unsigned char *b = skb_tail_pointer(skb);
+	struct tcf_ife_info *ife = a->priv;
+	struct tc_ife opt = {
+		.index = ife->tcf_index,
+		.refcnt = ife->tcf_refcnt - ref,
+		.bindcnt = ife->tcf_bindcnt - bind,
+		.action = ife->tcf_action,
+		.flags = ife->flags,
+	};
+	struct tcf_t t;
+
+	if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
+		goto nla_put_failure;
+
+	t.install = jiffies_to_clock_t(jiffies - ife->tcf_tm.install);
+	t.lastuse = jiffies_to_clock_t(jiffies - ife->tcf_tm.lastuse);
+	t.expires = jiffies_to_clock_t(ife->tcf_tm.expires);
+	if (nla_put(skb, TCA_IFE_TM, sizeof(t), &t))
+		goto nla_put_failure;
+
+	if (!is_zero_ether_addr(ife->eth_dst)) {
+		if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, ife->eth_dst))
+			goto nla_put_failure;
+	}
+
+	if (!is_zero_ether_addr(ife->eth_src)) {
+		if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, ife->eth_src))
+			goto nla_put_failure;
+	}
+
+	if (nla_put(skb, TCA_IFE_TYPE, 2, &ife->eth_type))
+		goto nla_put_failure;
+
+	if (dump_metalist(skb, ife)) {
+		/*ignore failure to dump metalist */
+		pr_info("Failed to dump metalist\n");
+	}
+
+	return skb->len;
+
+nla_put_failure:
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
+		       u16 metaid, u16 mlen, void *mdata)
+{
+	struct tcf_meta_info *e;
+
+	/* XXX: use hash to speed up */
+	list_for_each_entry(e, &ife->metalist, metalist) {
+		if (metaid == e->metaid) {
+			if (e->ops) {
+				/* We check for decode presence already */
+				return e->ops->decode(skb, mdata, mlen);
+			}
+		}
+	}
+
+	return 0;
+}
+
+struct ifeheadr {
+	__be16 metalen;
+	u8 tlv_data[];
+};
+
+struct meta_tlvhdr {
+	__be16 type;
+	__be16 len;
+};
+
+static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
+			  struct tcf_result *res)
+{
+	struct tcf_ife_info *ife = a->priv;
+	int action = ife->tcf_action;
+	struct ifeheadr *ifehdr = (struct ifeheadr *)skb->data;
+	u16 ifehdrln = ifehdr->metalen;
+	struct meta_tlvhdr *tlv = (struct meta_tlvhdr *)(ifehdr->tlv_data);
+
+	spin_lock(&ife->tcf_lock);
+	bstats_update(&ife->tcf_bstats, skb);
+	ife->tcf_tm.lastuse = jiffies;
+	spin_unlock(&ife->tcf_lock);
+
+	ifehdrln = ntohs(ifehdrln);
+	if (unlikely(!pskb_may_pull(skb, ifehdrln))) {
+		spin_lock(&ife->tcf_lock);
+		ife->tcf_qstats.drops++;
+		spin_unlock(&ife->tcf_lock);
+		return TC_ACT_SHOT;
+	}
+
+	skb_set_mac_header(skb, ifehdrln);
+	__skb_pull(skb, ifehdrln);
+	skb->protocol = eth_type_trans(skb, skb->dev);
+	ifehdrln -= IFE_METAHDRLEN;
+
+	while (ifehdrln > 0) {
+		u8 *tlvdata = (u8 *)tlv;
+		u16 mtype = tlv->type;
+		u16 mlen = tlv->len;
+
+		mtype = ntohs(mtype);
+		mlen = ntohs(mlen);
+
+		if (find_decode_metaid(skb, ife, mtype, (mlen - 4),
+				       (void *)(tlvdata + 4))) {
+			/* abuse overlimits to count when we receive metadata
+			 * but dont have an ops for it
+			 */
+			pr_info_ratelimited("Unknown metaid %d alnlen %d\n",
+					    mtype, mlen);
+			ife->tcf_qstats.overlimits++;
+		}
+
+		tlvdata += mlen;
+		ifehdrln -= mlen;
+		tlv = (struct meta_tlvhdr *)tlvdata;
+	}
+
+	skb_reset_network_header(skb);
+	return action;
+}
+
+/*XXX: check if we can do this at install time instead of current
+ * send data path
+**/
+static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
+{
+	struct tcf_meta_info *e, *n;
+	int tot_run_sz = 0, run_sz = 0;
+
+	list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
+		if (e->ops->check_presence) {
+			run_sz = e->ops->check_presence(skb, e);
+			tot_run_sz += run_sz;
+		}
+	}
+
+	return tot_run_sz;
+}
+
+static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
+			  struct tcf_result *res)
+{
+	struct tcf_ife_info *ife = a->priv;
+	int action = ife->tcf_action;
+	struct ethhdr *oethh;	/* outer ether header */
+	struct ethhdr *iethh;	/* inner eth header */
+	struct tcf_meta_info *e;
+	/*
+	   OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
+	   where ORIGDATA = original ethernet header ...
+	 */
+	u16 metalen = ife_get_sz(skb, ife);
+	int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
+	unsigned int skboff = skb->dev->hard_header_len;
+	u32 at = G_TC_AT(skb->tc_verd);
+	int new_len = skb->len + hdrm;
+	bool exceed_mtu = false;
+	int err;
+
+	if (at & AT_EGRESS) {
+		if (new_len > skb->dev->mtu)
+			exceed_mtu = true;
+	}
+
+	spin_lock(&ife->tcf_lock);
+	bstats_update(&ife->tcf_bstats, skb);
+	ife->tcf_tm.lastuse = jiffies;
+
+	if (!metalen) {		/* no metadata to send */
+		/* abuse overlimits to count when we allow packet
+		 * with no metadata
+		 */
+		ife->tcf_qstats.overlimits++;
+		spin_unlock(&ife->tcf_lock);
+		return action;
+	}
+	/* could be stupid policy setup or mtu config
+	 * so lets be conservative.. */
+	if ((action == TC_ACT_SHOT) || exceed_mtu) {
+		ife->tcf_qstats.drops++;
+		spin_unlock(&ife->tcf_lock);
+		return TC_ACT_SHOT;
+	}
+
+	iethh = eth_hdr(skb);
+
+	err = skb_cow_head(skb, hdrm);
+	if (unlikely(err)) {
+		ife->tcf_qstats.drops++;
+		spin_unlock(&ife->tcf_lock);
+		return TC_ACT_SHOT;
+	}
+
+	if (!(at & AT_EGRESS))
+		skb_push(skb, skb->dev->hard_header_len);
+
+	__skb_push(skb, hdrm);
+	memcpy(skb->data, iethh, skb->mac_len);
+	skb_reset_mac_header(skb);
+	oethh = eth_hdr(skb);
+
+	/*total metadata length */
+	metalen += IFE_METAHDRLEN;
+	metalen = htons(metalen);
+	memcpy((skb->data + skboff), &metalen, IFE_METAHDRLEN);
+	skboff += IFE_METAHDRLEN;
+
+	/* XXX: we dont have a clever way of telling encode to
+	 * not repeat some of the computations that are done by
+	 * ops->presence_check...
+	 */
+	list_for_each_entry(e, &ife->metalist, metalist) {
+		if (e->ops->encode) {
+			err = e->ops->encode(skb, (void *)(skb->data + skboff),
+					     e);
+		}
+		if (err < 0) {
+			/* too corrupt to keep around if overwritten */
+			ife->tcf_qstats.drops++;
+			spin_unlock(&ife->tcf_lock);
+			return TC_ACT_SHOT;
+		}
+		skboff += err;
+	}
+
+	if (!is_zero_ether_addr(ife->eth_src))
+		ether_addr_copy(oethh->h_source, ife->eth_src);
+	else
+		ether_addr_copy(oethh->h_source, iethh->h_source);
+	if (!is_zero_ether_addr(ife->eth_dst))
+		ether_addr_copy(oethh->h_dest, ife->eth_dst);
+	else
+		ether_addr_copy(oethh->h_dest, iethh->h_dest);
+	oethh->h_proto = htons(ife->eth_type);
+
+	if (!(at & AT_EGRESS))
+		skb_pull(skb, skb->dev->hard_header_len);
+
+	spin_unlock(&ife->tcf_lock);
+
+	return action;
+}
+
+static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
+		       struct tcf_result *res)
+{
+	struct tcf_ife_info *ife = a->priv;
+
+	if (ife->flags & IFE_ENCODE)
+		return tcf_ife_encode(skb, a, res);
+
+	if (!(ife->flags & IFE_ENCODE))
+		return tcf_ife_decode(skb, a, res);
+
+	pr_info_ratelimited("unknown failure(policy neither de/encode\n");
+	spin_lock(&ife->tcf_lock);
+	bstats_update(&ife->tcf_bstats, skb);
+	ife->tcf_tm.lastuse = jiffies;
+	ife->tcf_qstats.drops++;
+	spin_unlock(&ife->tcf_lock);
+
+	return TC_ACT_SHOT;
+}
+
+static int tcf_ife_walker(struct net *net, struct sk_buff *skb,
+			  struct netlink_callback *cb, int type,
+			  struct tc_action *a)
+{
+	struct tc_action_net *tn = net_generic(net, ife_net_id);
+
+	return tcf_generic_walker(tn, skb, cb, type, a);
+}
+
+static int tcf_ife_search(struct net *net, struct tc_action *a, u32 index)
+{
+	struct tc_action_net *tn = net_generic(net, ife_net_id);
+
+	return tcf_hash_search(tn, a, index);
+}
+
+static struct tc_action_ops act_ife_ops = {
+	.kind = "ife",
+	.type = TCA_ACT_IFE,
+	.owner = THIS_MODULE,
+	.act = tcf_ife_act,
+	.dump = tcf_ife_dump,
+	.cleanup = tcf_ife_cleanup,
+	.init = tcf_ife_init,
+	.walk = tcf_ife_walker,
+	.lookup = tcf_ife_search,
+};
+
+static __net_init int ife_init_net(struct net *net)
+{
+	struct tc_action_net *tn = net_generic(net, ife_net_id);
+
+	return tc_action_net_init(tn, &act_ife_ops, IFE_TAB_MASK);
+}
+
+static void __net_exit ife_exit_net(struct net *net)
+{
+	struct tc_action_net *tn = net_generic(net, ife_net_id);
+
+	tc_action_net_exit(tn);
+}
+
+static struct pernet_operations ife_net_ops = {
+	.init = ife_init_net,
+	.exit = ife_exit_net,
+	.id   = &ife_net_id,
+	.size = sizeof(struct tc_action_net),
+};
+
+static int __init ife_init_module(void)
+{
+	return tcf_register_action(&act_ife_ops, &ife_net_ops);
+}
+
+static void __exit ife_cleanup_module(void)
+{
+	tcf_unregister_action(&act_ife_ops, &ife_net_ops);
+}
+
+module_init(ife_init_module);
+module_exit(ife_cleanup_module);
+
+MODULE_AUTHOR("Jamal Hadi Salim(2015)");
+MODULE_DESCRIPTION("Inter-FE LFB action");
+MODULE_LICENSE("GPL");