path: root/net/sched/act_ife.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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
 *
 * 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 <net/pkt_cls.h>
#include <uapi/linux/tc_act/tc_ife.h>
#include <net/tc_act/tc_ife.h>
#include <linux/etherdevice.h>
#include <net/ife.h>

static unsigned int ife_net_id;
static int max_metacnt = IFE_META_MAX + 1;
static struct tc_action_ops act_ife_ops;

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},
};

int ife_encode_meta_u16(u16 metaval, void *skbdata, struct tcf_meta_info *mi)
{
	u16 edata = 0;

	if (mi->metaval)
		edata = *(u16 *)mi->metaval;
	else if (metaval)
		edata = metaval;

	if (!edata) /* will not encode */
		return 0;

	edata = htons(edata);
	return ife_tlv_meta_encode(skbdata, mi->metaid, 2, &edata);
}
EXPORT_SYMBOL_GPL(ife_encode_meta_u16);

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_check_meta_u16(u16 metaval, struct tcf_meta_info *mi)
{
	if (metaval || mi->metaval)
		return 8; /* T+L+(V) == 2+2+(2+2bytepad) */

	return 0;
}
EXPORT_SYMBOL_GPL(ife_check_meta_u16);

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, gfp_t gfp)
{
	mi->metaval = kmemdup(metaval, sizeof(u32), gfp);
	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, gfp_t gfp)
{
	mi->metaval = kmemdup(metaval, sizeof(u16), gfp);
	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 == sizeof(u32))
		return 0;

	return -EINVAL;
}
EXPORT_SYMBOL_GPL(ife_validate_meta_u32);

int ife_validate_meta_u16(void *val, int len)
{
	/* length will not include padding */
	if (len == sizeof(u16))
		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;