[mirror_ubuntu-hirsute-kernel.git] / net / sched / act_csum.c

/*
 * Checksum updating actions
 *
 * Copyright (c) 2010 Gregoire Baron <baronchon@n7mm.org>
 *
 * 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.
 *
 */

#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spinlock.h>

#include <linux/netlink.h>
#include <net/netlink.h>
#include <linux/rtnetlink.h>

#include <linux/skbuff.h>

#include <net/ip.h>
#include <net/ipv6.h>
#include <net/icmp.h>
#include <linux/icmpv6.h>
#include <linux/igmp.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/ip6_checksum.h>
#include <net/sctp/checksum.h>

#include <net/act_api.h>

#include <linux/tc_act/tc_csum.h>
#include <net/tc_act/tc_csum.h>

#define CSUM_TAB_MASK 15

static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
	[TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
};

static unsigned int csum_net_id;
static struct tc_action_ops act_csum_ops;

static int tcf_csum_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, csum_net_id);
	struct nlattr *tb[TCA_CSUM_MAX + 1];
	struct tc_csum *parm;
	struct tcf_csum *p;
	int ret = 0, err;

	if (nla == NULL)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_CSUM_MAX, nla, csum_policy, NULL);
	if (err < 0)
		return err;

	if (tb[TCA_CSUM_PARMS] == NULL)
		return -EINVAL;
	parm = nla_data(tb[TCA_CSUM_PARMS]);

	if (!tcf_hash_check(tn, parm->index, a, bind)) {
		ret = tcf_hash_create(tn, parm->index, est, a,
				      &act_csum_ops, 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;
	}

	p = to_tcf_csum(*a);
	spin_lock_bh(&p->tcf_lock);
	p->tcf_action = parm->action;
	p->update_flags = parm->update_flags;
	spin_unlock_bh(&p->tcf_lock);

	if (ret == ACT_P_CREATED)
		tcf_hash_insert(tn, *a);

	return ret;
}

/**
 * tcf_csum_skb_nextlayer - Get next layer pointer
 * @skb: sk_buff to use
 * @ihl: previous summed headers length
 * @ipl: complete packet length
 * @jhl: next header length
 *
 * Check the expected next layer availability in the specified sk_buff.
 * Return the next layer pointer if pass, NULL otherwise.
 */
static void *tcf_csum_skb_nextlayer(struct sk_buff *skb,
				    unsigned int ihl, unsigned int ipl,
				    unsigned int jhl)
{
	int ntkoff = skb_network_offset(skb);
	int hl = ihl + jhl;

	if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) ||
	    skb_try_make_writable(skb, hl + ntkoff))
		return NULL;
	else
		return (void *)(skb_network_header(skb) + ihl);
}

static int tcf_csum_ipv4_icmp(struct sk_buff *skb, unsigned int ihl,
			      unsigned int ipl)
{
	struct icmphdr *icmph;

	icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
	if (icmph == NULL)
		return 0;

	icmph->checksum = 0;
	skb->csum = csum_partial(icmph, ipl - ihl, 0);
	icmph->checksum = csum_fold(skb->csum);

	skb->ip_summed = CHECKSUM_NONE;

	return 1;
}

static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
			      unsigned int ihl, unsigned int ipl)
{
	struct igmphdr *igmph;

	igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
	if (igmph == NULL)
		return 0;

	igmph->csum = 0;
	skb->csum = csum_partial(igmph, ipl - ihl, 0);
	igmph->csum = csum_fold(skb->csum);

	skb->ip_summed = CHECKSUM_NONE;

	return 1;
}

static int tcf_csum_ipv6_icmp(struct sk_buff *skb, unsigned int ihl,
			      unsigned int ipl)
{
	struct icmp6hdr *icmp6h;
	const struct ipv6hdr *ip6h;

	icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
	if (icmp6h == NULL)
		return 0;

	ip6h = ipv6_hdr(skb);
	icmp6h->icmp6_cksum = 0;
	skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
	icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
					      ipl - ihl, IPPROTO_ICMPV6,
					      skb->csum);

	skb->ip_summed = CHECKSUM_NONE;

	return 1;
}

static int tcf_csum_ipv4_tcp(struct sk_buff *skb, unsigned int ihl,
			     unsigned int ipl)
{
	struct tcphdr *tcph;
	const struct iphdr *iph;

	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
		return 1;

	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
	if (tcph == NULL)
		return 0;

	iph = ip_hdr(skb);
	tcph->check = 0;
	skb->csum = csum_partial(tcph, ipl - ihl, 0);
	tcph->check = tcp_v4_check(ipl - ihl,
				   iph->saddr, iph->daddr, skb->csum);

	skb->ip_summed = CHECKSUM_NONE;

	return 1;
}

static int tcf_csum_ipv6_tcp(struct sk_buff *skb, unsigned int ihl,
			     unsigned int ipl)
{
	struct tcphdr *tcph;
	const struct ipv6hdr *ip6h;

	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
		return 1;

	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
	if (tcph == NULL)
		return 0;

	ip6h = ipv6_hdr(skb);
	tcph->check = 0;
	skb->csum = csum_partial(tcph, ipl - ihl, 0);
	tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
				      ipl - ihl, IPPROTO_TCP,
				      skb->csum);

	skb->ip_summed = CHECKSUM_NONE;

	return 1;
}

static int tcf_csum_ipv4_udp(struct sk_buff *skb, unsigned int ihl,
			     unsigned int ipl, int udplite)
{
	struct udphdr *udph;
	const struct iphdr *iph;
	u16 ul;

	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
		return 1;

	/*
	 * Support both UDP and UDPLITE checksum algorithms, Don't use
	 * udph->len to get the real length without any protocol check,
	 * UDPLITE uses udph->len for another thing,
	 * Use iph->tot_len, or just ipl.
	 */

	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
	if (udph == NULL)
		return 0;

	iph = ip_hdr(skb);
	ul = ntohs(udph->len);

	if (udplite || udph->check) {

		udph->check = 0;

		if (udplite) {
			if (ul == 0)
				skb->csum = csum_partial(udph, ipl - ihl, 0);
			else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
				skb->csum = csum_partial(udph, ul, 0);
			else
				goto ignore_obscure_skb;
		} else {
			if (ul != ipl - ihl)
				goto ignore_obscure_skb;

			skb->csum = csum_partial(udph, ul, 0);
		}

		udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
						ul, iph->protocol,
						skb->csum);

		if (!udph->check)
			udph->check = CSUM_MANGLED_0;
	}

	skb->ip_summed = CHECKSUM_NONE;

ignore_obscure_skb:
	return 1;
}

static int tcf_csum_ipv6_udp(struct sk_buff *skb, unsigned int ihl,
			     unsigned int ipl, int udplite)
{
	struct udphdr *udph;
	const struct ipv6hdr *ip6h;
	u16 ul;

	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
		return 1;

	/*
	 * Support both UDP and UDPLITE checksum algorithms, Don't use
	 * udph->len to get the real length without any protocol check,
	 * UDPLITE uses udph->len for another thing,
	 * Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
	 */

	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
	if (udph == NULL)
		return 0;

	ip6h = ipv6_hdr(skb);
	ul = ntohs(udph->len);

	udph->check = 0;

	if (udplite) {
		if (ul == 0)
			skb->csum = csum_partial(udph, ipl - ihl, 0);

		else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
			skb->csum = csum_partial(udph, ul, 0);

		else
			goto ignore_obscure_skb;
	} else {
		if (ul != ipl - ihl)
			goto ignore_obscure_skb;

		skb->csum = csum_partial(udph, ul, 0);
	}

	udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
				      udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
				      skb->csum);

	if (!udph->check)
		udph->check = CSUM_MANGLED_0;

	skb->ip_summed = CHECKSUM_NONE;

ignore_obscure_skb:
	return 1;
}

static int tcf_csum_sctp(struct sk_buff *skb, unsigned int ihl,
			 unsigned int ipl)
{
	struct sctphdr *sctph;

	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_SCTP)
		return 1;

	sctph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*sctph));
	if (!sctph)
		return 0;

	sctph->checksum = sctp_compute_cksum(skb,
					     skb_network_offset(skb) + ihl);
	skb->ip_summed = CHECKSUM_NONE;

	return 1;
}

static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
{
	const struct iphdr *iph;
	int ntkoff;

	ntkoff = skb_network_offset(skb);

	if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
		goto fail;

	iph = ip_hdr(skb);

	switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
	case IPPROTO_ICMP:
		if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
			if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
						ntohs(iph->tot_len)))
				goto fail;
		break;
	case IPPROTO_IGMP:
		if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
			if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
						ntohs(iph->tot_len)))
				goto fail;
		break;
	case IPPROTO_TCP:
		if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
			if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
					       ntohs(iph->tot_len)))
				goto fail;
		break;
	case IPPROTO_UDP:
		if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
			if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
					       ntohs(iph->tot_len), 0))
				goto fail;
		break;
	case IPPROTO_UDPLITE:
		if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
			if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
					       ntohs(iph->tot_len), 1))
				goto fail;
		break;
	case IPPROTO_SCTP:
		if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
		    !tcf_csum_sctp(skb, iph->ihl * 4, ntohs(iph->tot_len)))
			goto fail;
		break;
	}

	if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
		if (skb_try_make_writable(skb, sizeof(*iph) + ntkoff))
			goto fail;

		ip_send_check(ip_hdr(skb));
	}

	return 1;

fail:
	return 0;
}

static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh, unsigned int ixhl,
				 unsigned int *pl)
{
	int off, len, optlen;
	unsigned char *xh = (void *)ip6xh;

	off = sizeof(*ip6xh);
	len = ixhl - off;

	while (len > 1) {
		switch (xh[off]) {
		case IPV6_TLV_PAD1:
			optlen = 1;
			break;
		case IPV6_TLV_JUMBO:
			optlen = xh[off + 1] + 2;
			if (optlen != 6 || len < 6 || (off & 3) != 2)
				/* wrong jumbo option length/alignment */
				return 0;
			*pl = ntohl(*(__be32 *)(xh + off + 2));
			goto done;
		default:
			optlen = xh[off + 1] + 2;
			if (optlen > len)
				/* ignore obscure options */
				goto done;
			break;
		}
		off += optlen;
		len -= optlen;
	}

done:
	return 1;
}

static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
{
	struct ipv6hdr *ip6h;
	struct ipv6_opt_hdr *ip6xh;
	unsigned int hl, ixhl;
	unsigned int pl;
	int ntkoff;
	u8 nexthdr;

	ntkoff = skb_network_offset(skb);

	hl = sizeof(*ip6h);

	if (!pskb_may_pull(skb, hl + ntkoff))
		goto fail;

	ip6h = ipv6_hdr(skb);

	pl = ntohs(ip6h->payload_len);
	nexthdr = ip6h->nexthdr;

	do {
		switch (nexthdr) {
		case NEXTHDR_FRAGMENT:
			goto ignore_skb;
		case NEXTHDR_ROUTING:
		case NEXTHDR_HOP:
		case NEXTHDR_DEST:
			if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
				goto fail;
			ip6xh = (void *)(skb_network_header(skb) + hl);
			ixhl = ipv6_optlen(ip6xh);
			if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
				goto fail;
			ip6xh = (void *)(skb_network_header(skb) + hl);
			if ((nexthdr == NEXTHDR_HOP) &&
			    !(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
				goto fail;
			nexthdr = ip6xh->nexthdr;
			hl += ixhl;
			break;
		case IPPROTO_ICMPV6:
			if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
				if (!tcf_csum_ipv6_icmp(skb,
							hl, pl + sizeof(*ip6h)))
					goto fail;
			goto done;
		case IPPROTO_TCP:
			if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
				if (!tcf_csum_ipv6_tcp(skb,
						       hl, pl + sizeof(*ip6h)))
					goto fail;
			goto done;
		case IPPROTO_UDP:
			if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
				if (!tcf_csum_ipv6_udp(skb, hl,
						       pl + sizeof(*ip6h), 0))
					goto fail;
			goto done;
		case IPPROTO_UDPLITE:
			if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
				if (!tcf_csum_ipv6_udp(skb, hl,
						       pl + sizeof(*ip6h), 1))
					goto fail;
			goto done;
		case IPPROTO_SCTP:
			if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
			    !tcf_csum_sctp(skb, hl, pl + sizeof(*ip6h)))
				goto fail;
			goto done;
		default:
			goto ignore_skb;
		}
	} while (pskb_may_pull(skb, hl + 1 + ntkoff));

done:
ignore_skb:
	return 1;

fail:
	return 0;
}

static int tcf_csum(struct sk_buff *skb, const struct tc_action *a,
		    struct tcf_result *res)
{
	struct tcf_csum *p = to_tcf_csum(a);
	int action;
	u32 update_flags;

	spin_lock(&p->tcf_lock);
	tcf_lastuse_update(&p->tcf_tm);
	bstats_update(&p->tcf_bstats, skb);
	action = p->tcf_action;
	update_flags = p->update_flags;
	spin_unlock(&p->tcf_lock);

	if (unlikely(action == TC_ACT_SHOT))
		goto drop;

	switch (tc_skb_protocol(skb)) {
	case cpu_to_be16(ETH_P_IP):
		if (!tcf_csum_ipv4(skb, update_flags))
			goto drop;
		break;
	case cpu_to_be16(ETH_P_IPV6):
		if (!tcf_csum_ipv6(skb, update_flags))
			goto drop;
		break;
	}

	return action;

drop:
	spin_lock(&p->tcf_lock);
	p->tcf_qstats.drops++;
	spin_unlock(&p->tcf_lock);
	return TC_ACT_SHOT;
}

static int tcf_csum_dump(struct sk_buff *skb, struct tc_action *a, int bind,
			 int ref)
{
	unsigned char *b = skb_tail_pointer(skb);
	struct tcf_csum *p = to_tcf_csum(a);
	struct tc_csum opt = {
		.update_flags = p->update_flags,
		.index   = p->tcf_index,
		.action  = p->tcf_action,
		.refcnt  = p->tcf_refcnt - ref,
		.bindcnt = p->tcf_bindcnt - bind,
	};
	struct tcf_t t;

	if (nla_put(skb, TCA_CSUM_PARMS, sizeof(opt), &opt))
		goto nla_put_failure;

	tcf_tm_dump(&t, &p->tcf_tm);
	if (nla_put_64bit(skb, TCA_CSUM_TM, sizeof(t), &t, TCA_CSUM_PAD))
		goto nla_put_failure;

	return skb->len;

nla_put_failure:
	nlmsg_trim(skb, b);
	return -1;
}

static int tcf_csum_walker(struct net *net, struct sk_buff *skb,
			   struct netlink_callback *cb, int type,
			   const struct tc_action_ops *ops)
{
	struct tc_action_net *tn = net_generic(net, csum_net_id);

	return tcf_generic_walker(tn, skb, cb, type, ops);
}

static int tcf_csum_search(struct net *net, struct tc_action **a, u32 index)
{
	struct tc_action_net *tn = net_generic(net, csum_net_id);

	return tcf_hash_search(tn, a, index);
}

static struct tc_action_ops act_csum_ops = {
	.kind		= "csum",
	.type		= TCA_ACT_CSUM,
	.owner		= THIS_MODULE,
	.act		= tcf_csum,
	.dump		= tcf_csum_dump,
	.init		= tcf_csum_init,
	.walk		= tcf_csum_walker,
	.lookup		= tcf_csum_search,
	.size		= sizeof(struct tcf_csum),
};

static __net_init int csum_init_net(struct net *net)
{
	struct tc_action_net *tn = net_generic(net, csum_net_id);

	return tc_action_net_init(tn, &act_csum_ops, CSUM_TAB_MASK);
}

static void __net_exit csum_exit_net(struct net *net)
{
	struct tc_action_net *tn = net_generic(net, csum_net_id);

	tc_action_net_exit(tn);
}

static struct pernet_operations csum_net_ops = {
	.init = csum_init_net,
	.exit = csum_exit_net,
	.id   = &csum_net_id,
	.size = sizeof(struct tc_action_net),
};

MODULE_DESCRIPTION("Checksum updating actions");
MODULE_LICENSE("GPL");

static int __init csum_init_module(void)
{
	return tcf_register_action(&act_csum_ops, &csum_net_ops);
}

static void __exit csum_cleanup_module(void)
{
	tcf_unregister_action(&act_csum_ops, &csum_net_ops);
}

module_init(csum_init_module);
module_exit(csum_cleanup_module);
Commit	Line	Data
eb4d4065 GB	1	/*
	2	* Checksum updating actions
	3	*
	4	* Copyright (c) 2010 Gregoire Baron <baronchon@n7mm.org>
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the Free
	8	* Software Foundation; either version 2 of the License, or (at your option)
	9	* any later version.
	10	*
	11	*/
	12
	13	#include <linux/types.h>
	14	#include <linux/init.h>
	15	#include <linux/kernel.h>
	16	#include <linux/module.h>
	17	#include <linux/spinlock.h>
	18
	19	#include <linux/netlink.h>
	20	#include <net/netlink.h>
	21	#include <linux/rtnetlink.h>
	22
	23	#include <linux/skbuff.h>
	24
	25	#include <net/ip.h>
	26	#include <net/ipv6.h>
	27	#include <net/icmp.h>
	28	#include <linux/icmpv6.h>
	29	#include <linux/igmp.h>
	30	#include <net/tcp.h>
	31	#include <net/udp.h>
2436243a	32	#include <net/ip6_checksum.h>
c008b33f	33	#include <net/sctp/checksum.h>
eb4d4065 GB	34
	35	#include <net/act_api.h>
	36
	37	#include <linux/tc_act/tc_csum.h>
	38	#include <net/tc_act/tc_csum.h>
	39
	40	#define CSUM_TAB_MASK 15
eb4d4065 GB	41
	42	static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
	43	[TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
	44	};
	45
c7d03a00	46	static unsigned int csum_net_id;
a85a970a	47	static struct tc_action_ops act_csum_ops;
ddf97ccd WC	48
ddf97ccd WC	49	static int tcf_csum_init(struct net net, struct nlattr nla,
a85a970a	50	struct nlattr est, struct tc_action *a, int ovr,
ddf97ccd	51	int bind)
eb4d4065	52	{
ddf97ccd	53	struct tc_action_net *tn = net_generic(net, csum_net_id);
eb4d4065 GB	54	struct nlattr *tb[TCA_CSUM_MAX + 1];
eb4d4065 GB	55	struct tc_csum *parm;
eb4d4065 GB	56	struct tcf_csum *p;
	57	int ret = 0, err;
	58
	59	if (nla == NULL)
	60	return -EINVAL;
	61
fceb6435	62	err = nla_parse_nested(tb, TCA_CSUM_MAX, nla, csum_policy, NULL);
eb4d4065 GB	63	if (err < 0)
	64	return err;
	65
	66	if (tb[TCA_CSUM_PARMS] == NULL)
	67	return -EINVAL;
	68	parm = nla_data(tb[TCA_CSUM_PARMS]);
	69
ddf97ccd WC	70	if (!tcf_hash_check(tn, parm->index, a, bind)) {
ddf97ccd WC	71	ret = tcf_hash_create(tn, parm->index, est, a,
a85a970a	72	&act_csum_ops, bind, false);
86062033 WC	73	if (ret)
86062033 WC	74	return ret;
eb4d4065 GB	75	ret = ACT_P_CREATED;
eb4d4065 GB	76	} else {
1a29321e JHS	77	if (bind)/* dont override defaults */
1a29321e JHS	78	return 0;
a85a970a	79	tcf_hash_release(*a, bind);
1a29321e	80	if (!ovr)
eb4d4065	81	return -EEXIST;
eb4d4065 GB	82	}
eb4d4065 GB	83
a85a970a	84	p = to_tcf_csum(*a);
eb4d4065 GB	85	spin_lock_bh(&p->tcf_lock);
	86	p->tcf_action = parm->action;
	87	p->update_flags = parm->update_flags;
	88	spin_unlock_bh(&p->tcf_lock);
	89
	90	if (ret == ACT_P_CREATED)
a85a970a	91	tcf_hash_insert(tn, *a);
eb4d4065 GB	92
	93	return ret;
	94	}
	95
eb4d4065 GB	96	/**
	97	* tcf_csum_skb_nextlayer - Get next layer pointer
	98	* @skb: sk_buff to use
	99	* @ihl: previous summed headers length
	100	* @ipl: complete packet length
	101	* @jhl: next header length
	102	*
	103	* Check the expected next layer availability in the specified sk_buff.
	104	* Return the next layer pointer if pass, NULL otherwise.
	105	*/
	106	static void tcf_csum_skb_nextlayer(struct sk_buff skb,
	107	unsigned int ihl, unsigned int ipl,
	108	unsigned int jhl)
	109	{
	110	int ntkoff = skb_network_offset(skb);
	111	int hl = ihl + jhl;
	112
	113	if (!pskb_may_pull(skb, ipl + ntkoff) \|\| (ipl < hl) \|\|
3697649f	114	skb_try_make_writable(skb, hl + ntkoff))
eb4d4065 GB	115	return NULL;
	116	else
	117	return (void *)(skb_network_header(skb) + ihl);
	118	}
	119
5a7a5555 JHS	120	static int tcf_csum_ipv4_icmp(struct sk_buff *skb, unsigned int ihl,
5a7a5555 JHS	121	unsigned int ipl)
eb4d4065 GB	122	{
	123	struct icmphdr *icmph;
	124
	125	icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
	126	if (icmph == NULL)
	127	return 0;
	128
	129	icmph->checksum = 0;
	130	skb->csum = csum_partial(icmph, ipl - ihl, 0);
	131	icmph->checksum = csum_fold(skb->csum);
	132
	133	skb->ip_summed = CHECKSUM_NONE;
	134
	135	return 1;
	136	}
	137
	138	static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
	139	unsigned int ihl, unsigned int ipl)
	140	{
	141	struct igmphdr *igmph;
	142
	143	igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
	144	if (igmph == NULL)
	145	return 0;
	146
	147	igmph->csum = 0;
	148	skb->csum = csum_partial(igmph, ipl - ihl, 0);
	149	igmph->csum = csum_fold(skb->csum);
	150
	151	skb->ip_summed = CHECKSUM_NONE;
	152
	153	return 1;
	154	}
	155
5a7a5555 JHS	156	static int tcf_csum_ipv6_icmp(struct sk_buff *skb, unsigned int ihl,
5a7a5555 JHS	157	unsigned int ipl)
eb4d4065 GB	158	{
eb4d4065 GB	159	struct icmp6hdr *icmp6h;
d14a489a	160	const struct ipv6hdr *ip6h;
eb4d4065 GB	161
	162	icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
	163	if (icmp6h == NULL)
	164	return 0;
	165
d14a489a	166	ip6h = ipv6_hdr(skb);
eb4d4065 GB	167	icmp6h->icmp6_cksum = 0;
	168	skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
	169	icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
	170	ipl - ihl, IPPROTO_ICMPV6,
	171	skb->csum);
	172
	173	skb->ip_summed = CHECKSUM_NONE;
	174
	175	return 1;
	176	}
	177
5a7a5555 JHS	178	static int tcf_csum_ipv4_tcp(struct sk_buff *skb, unsigned int ihl,
5a7a5555 JHS	179	unsigned int ipl)
eb4d4065 GB	180	{
eb4d4065 GB	181	struct tcphdr *tcph;
d14a489a	182	const struct iphdr *iph;
eb4d4065	183
add641e7 DC	184	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
	185	return 1;
	186
eb4d4065 GB	187	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
	188	if (tcph == NULL)
	189	return 0;
	190
d14a489a	191	iph = ip_hdr(skb);
eb4d4065 GB	192	tcph->check = 0;
	193	skb->csum = csum_partial(tcph, ipl - ihl, 0);
	194	tcph->check = tcp_v4_check(ipl - ihl,
	195	iph->saddr, iph->daddr, skb->csum);
	196
	197	skb->ip_summed = CHECKSUM_NONE;
	198
	199	return 1;
	200	}
	201
5a7a5555 JHS	202	static int tcf_csum_ipv6_tcp(struct sk_buff *skb, unsigned int ihl,
5a7a5555 JHS	203	unsigned int ipl)
eb4d4065 GB	204	{
eb4d4065 GB	205	struct tcphdr *tcph;
d14a489a	206	const struct ipv6hdr *ip6h;
eb4d4065	207
add641e7 DC	208	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
	209	return 1;
	210
eb4d4065 GB	211	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
	212	if (tcph == NULL)
	213	return 0;
	214
d14a489a	215	ip6h = ipv6_hdr(skb);
eb4d4065 GB	216	tcph->check = 0;
	217	skb->csum = csum_partial(tcph, ipl - ihl, 0);
	218	tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
	219	ipl - ihl, IPPROTO_TCP,
	220	skb->csum);
	221
	222	skb->ip_summed = CHECKSUM_NONE;
	223
	224	return 1;
	225	}
	226
5a7a5555 JHS	227	static int tcf_csum_ipv4_udp(struct sk_buff *skb, unsigned int ihl,
5a7a5555 JHS	228	unsigned int ipl, int udplite)
eb4d4065 GB	229	{
eb4d4065 GB	230	struct udphdr *udph;
d14a489a	231	const struct iphdr *iph;
eb4d4065 GB	232	u16 ul;
eb4d4065 GB	233
add641e7 DC	234	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
	235	return 1;
	236
0eec32ff CG	237	/*
	238	* Support both UDP and UDPLITE checksum algorithms, Don't use
	239	* udph->len to get the real length without any protocol check,
eb4d4065 GB	240	* UDPLITE uses udph->len for another thing,
	241	* Use iph->tot_len, or just ipl.
	242	*/
	243
	244	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
	245	if (udph == NULL)
	246	return 0;
	247
d14a489a	248	iph = ip_hdr(skb);
eb4d4065 GB	249	ul = ntohs(udph->len);
	250
	251	if (udplite \|\| udph->check) {
	252
	253	udph->check = 0;
	254
	255	if (udplite) {
	256	if (ul == 0)
	257	skb->csum = csum_partial(udph, ipl - ihl, 0);
eb4d4065 GB	258	else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
eb4d4065 GB	259	skb->csum = csum_partial(udph, ul, 0);
eb4d4065 GB	260	else
	261	goto ignore_obscure_skb;
	262	} else {
	263	if (ul != ipl - ihl)
	264	goto ignore_obscure_skb;
	265
	266	skb->csum = csum_partial(udph, ul, 0);
	267	}
	268
	269	udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
	270	ul, iph->protocol,
	271	skb->csum);
	272
	273	if (!udph->check)
	274	udph->check = CSUM_MANGLED_0;
	275	}
	276
	277	skb->ip_summed = CHECKSUM_NONE;
	278
	279	ignore_obscure_skb:
	280	return 1;
	281	}
	282
5a7a5555 JHS	283	static int tcf_csum_ipv6_udp(struct sk_buff *skb, unsigned int ihl,
5a7a5555 JHS	284	unsigned int ipl, int udplite)
eb4d4065 GB	285	{
eb4d4065 GB	286	struct udphdr *udph;
d14a489a	287	const struct ipv6hdr *ip6h;
eb4d4065 GB	288	u16 ul;
eb4d4065 GB	289
add641e7 DC	290	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
	291	return 1;
	292
0eec32ff CG	293	/*
	294	* Support both UDP and UDPLITE checksum algorithms, Don't use
	295	* udph->len to get the real length without any protocol check,
eb4d4065 GB	296	* UDPLITE uses udph->len for another thing,
	297	* Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
	298	*/
	299
	300	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
	301	if (udph == NULL)
	302	return 0;
	303
d14a489a	304	ip6h = ipv6_hdr(skb);
eb4d4065 GB	305	ul = ntohs(udph->len);
	306
	307	udph->check = 0;
	308
	309	if (udplite) {
	310	if (ul == 0)
	311	skb->csum = csum_partial(udph, ipl - ihl, 0);
	312
	313	else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
	314	skb->csum = csum_partial(udph, ul, 0);
	315
	316	else
	317	goto ignore_obscure_skb;
	318	} else {
	319	if (ul != ipl - ihl)
	320	goto ignore_obscure_skb;
	321
	322	skb->csum = csum_partial(udph, ul, 0);
	323	}
	324
	325	udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
	326	udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
	327	skb->csum);
	328
	329	if (!udph->check)
	330	udph->check = CSUM_MANGLED_0;
	331
	332	skb->ip_summed = CHECKSUM_NONE;
	333
	334	ignore_obscure_skb:
	335	return 1;
	336	}
	337
c008b33f DC	338	static int tcf_csum_sctp(struct sk_buff *skb, unsigned int ihl,
	339	unsigned int ipl)
	340	{
	341	struct sctphdr *sctph;
	342
	343	if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_SCTP)
	344	return 1;
	345
	346	sctph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*sctph));
	347	if (!sctph)
	348	return 0;
	349
	350	sctph->checksum = sctp_compute_cksum(skb,
	351	skb_network_offset(skb) + ihl);
	352	skb->ip_summed = CHECKSUM_NONE;
	353
	354	return 1;
	355	}
	356
eb4d4065 GB	357	static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
eb4d4065 GB	358	{
d14a489a	359	const struct iphdr *iph;
eb4d4065 GB	360	int ntkoff;
	361
	362	ntkoff = skb_network_offset(skb);
	363
	364	if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
	365	goto fail;
	366
	367	iph = ip_hdr(skb);
	368
	369	switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
	370	case IPPROTO_ICMP:
	371	if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
0eec32ff CG	372	if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
0eec32ff CG	373	ntohs(iph->tot_len)))
eb4d4065 GB	374	goto fail;
	375	break;
	376	case IPPROTO_IGMP:
	377	if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
0eec32ff CG	378	if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
0eec32ff CG	379	ntohs(iph->tot_len)))
eb4d4065 GB	380	goto fail;
	381	break;
	382	case IPPROTO_TCP:
	383	if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
d14a489a	384	if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
0eec32ff	385	ntohs(iph->tot_len)))
eb4d4065 GB	386	goto fail;
	387	break;
	388	case IPPROTO_UDP:
	389	if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
d14a489a	390	if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
0eec32ff	391	ntohs(iph->tot_len), 0))
eb4d4065 GB	392	goto fail;
	393	break;
	394	case IPPROTO_UDPLITE:
	395	if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
d14a489a	396	if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
0eec32ff	397	ntohs(iph->tot_len), 1))
eb4d4065 GB	398	goto fail;
eb4d4065 GB	399	break;
c008b33f DC	400	case IPPROTO_SCTP:
	401	if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
	402	!tcf_csum_sctp(skb, iph->ihl * 4, ntohs(iph->tot_len)))
	403	goto fail;
	404	break;
eb4d4065 GB	405	}
	406
	407	if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
3697649f	408	if (skb_try_make_writable(skb, sizeof(*iph) + ntkoff))
eb4d4065 GB	409	goto fail;
eb4d4065 GB	410
d14a489a	411	ip_send_check(ip_hdr(skb));
eb4d4065 GB	412	}
	413
	414	return 1;
	415
	416	fail:
	417	return 0;
	418	}
	419
5a7a5555 JHS	420	static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh, unsigned int ixhl,
5a7a5555 JHS	421	unsigned int *pl)
eb4d4065 GB	422	{
	423	int off, len, optlen;
	424	unsigned char xh = (void )ip6xh;
	425
	426	off = sizeof(*ip6xh);
	427	len = ixhl - off;
	428
	429	while (len > 1) {
0eec32ff	430	switch (xh[off]) {
1de5a71c	431	case IPV6_TLV_PAD1:
eb4d4065 GB	432	optlen = 1;
	433	break;
	434	case IPV6_TLV_JUMBO:
	435	optlen = xh[off + 1] + 2;
	436	if (optlen != 6 \|\| len < 6 \|\| (off & 3) != 2)
	437	/* wrong jumbo option length/alignment */
	438	return 0;
	439	pl = ntohl((__be32 *)(xh + off + 2));
	440	goto done;
	441	default:
	442	optlen = xh[off + 1] + 2;
	443	if (optlen > len)
	444	/* ignore obscure options */
	445	goto done;
	446	break;
	447	}
	448	off += optlen;
	449	len -= optlen;
	450	}
	451
	452	done:
	453	return 1;
	454	}
	455
	456	static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
	457	{
	458	struct ipv6hdr *ip6h;
	459	struct ipv6_opt_hdr *ip6xh;
	460	unsigned int hl, ixhl;
	461	unsigned int pl;
	462	int ntkoff;
	463	u8 nexthdr;
	464
	465	ntkoff = skb_network_offset(skb);
	466
	467	hl = sizeof(*ip6h);
	468
	469	if (!pskb_may_pull(skb, hl + ntkoff))
	470	goto fail;
	471
	472	ip6h = ipv6_hdr(skb);
	473
	474	pl = ntohs(ip6h->payload_len);
	475	nexthdr = ip6h->nexthdr;
	476
	477	do {
	478	switch (nexthdr) {
	479	case NEXTHDR_FRAGMENT:
	480	goto ignore_skb;
	481	case NEXTHDR_ROUTING:
	482	case NEXTHDR_HOP:
	483	case NEXTHDR_DEST:
	484	if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
	485	goto fail;
	486	ip6xh = (void *)(skb_network_header(skb) + hl);
	487	ixhl = ipv6_optlen(ip6xh);
	488	if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
	489	goto fail;
d14a489a	490	ip6xh = (void *)(skb_network_header(skb) + hl);
eb4d4065 GB	491	if ((nexthdr == NEXTHDR_HOP) &&
	492	!(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
	493	goto fail;
	494	nexthdr = ip6xh->nexthdr;
	495	hl += ixhl;
	496	break;
	497	case IPPROTO_ICMPV6:
	498	if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
d14a489a	499	if (!tcf_csum_ipv6_icmp(skb,
eb4d4065 GB	500	hl, pl + sizeof(*ip6h)))
	501	goto fail;
	502	goto done;
	503	case IPPROTO_TCP:
	504	if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
d14a489a	505	if (!tcf_csum_ipv6_tcp(skb,
eb4d4065 GB	506	hl, pl + sizeof(*ip6h)))
	507	goto fail;
	508	goto done;
	509	case IPPROTO_UDP:
	510	if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
d14a489a	511	if (!tcf_csum_ipv6_udp(skb, hl,
0eec32ff	512	pl + sizeof(*ip6h), 0))
eb4d4065 GB	513	goto fail;
	514	goto done;
	515	case IPPROTO_UDPLITE:
	516	if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
d14a489a	517	if (!tcf_csum_ipv6_udp(skb, hl,
0eec32ff	518	pl + sizeof(*ip6h), 1))
eb4d4065 GB	519	goto fail;
eb4d4065 GB	520	goto done;
c008b33f DC	521	case IPPROTO_SCTP:
	522	if ((update_flags & TCA_CSUM_UPDATE_FLAG_SCTP) &&
	523	!tcf_csum_sctp(skb, hl, pl + sizeof(*ip6h)))
	524	goto fail;
	525	goto done;
eb4d4065 GB	526	default:
	527	goto ignore_skb;
	528	}
	529	} while (pskb_may_pull(skb, hl + 1 + ntkoff));
	530
	531	done:
	532	ignore_skb:
	533	return 1;
	534
	535	fail:
	536	return 0;
	537	}
	538
5a7a5555 JHS	539	static int tcf_csum(struct sk_buff skb, const struct tc_action a,
5a7a5555 JHS	540	struct tcf_result *res)
eb4d4065	541	{
a85a970a	542	struct tcf_csum *p = to_tcf_csum(a);
eb4d4065 GB	543	int action;
	544	u32 update_flags;
	545
	546	spin_lock(&p->tcf_lock);
9c4a4e48	547	tcf_lastuse_update(&p->tcf_tm);
bfe0d029	548	bstats_update(&p->tcf_bstats, skb);
eb4d4065 GB	549	action = p->tcf_action;
	550	update_flags = p->update_flags;
	551	spin_unlock(&p->tcf_lock);
	552
	553	if (unlikely(action == TC_ACT_SHOT))
	554	goto drop;
	555
d8b9605d	556	switch (tc_skb_protocol(skb)) {
eb4d4065 GB	557	case cpu_to_be16(ETH_P_IP):
	558	if (!tcf_csum_ipv4(skb, update_flags))
	559	goto drop;
	560	break;
	561	case cpu_to_be16(ETH_P_IPV6):
	562	if (!tcf_csum_ipv6(skb, update_flags))
	563	goto drop;
	564	break;
	565	}
	566
	567	return action;
	568
	569	drop:
	570	spin_lock(&p->tcf_lock);
	571	p->tcf_qstats.drops++;
	572	spin_unlock(&p->tcf_lock);
	573	return TC_ACT_SHOT;
	574	}
	575
5a7a5555 JHS	576	static int tcf_csum_dump(struct sk_buff skb, struct tc_action a, int bind,
5a7a5555 JHS	577	int ref)
eb4d4065 GB	578	{
eb4d4065 GB	579	unsigned char *b = skb_tail_pointer(skb);
a85a970a	580	struct tcf_csum *p = to_tcf_csum(a);
eb4d4065 GB	581	struct tc_csum opt = {
eb4d4065 GB	582	.update_flags = p->update_flags,
eb4d4065 GB	583	.index = p->tcf_index,
	584	.action = p->tcf_action,
	585	.refcnt = p->tcf_refcnt - ref,
	586	.bindcnt = p->tcf_bindcnt - bind,
	587	};
	588	struct tcf_t t;
	589
1b34ec43 DM	590	if (nla_put(skb, TCA_CSUM_PARMS, sizeof(opt), &opt))
1b34ec43 DM	591	goto nla_put_failure;
48d8ee16 JHS	592
48d8ee16 JHS	593	tcf_tm_dump(&t, &p->tcf_tm);
9854518e	594	if (nla_put_64bit(skb, TCA_CSUM_TM, sizeof(t), &t, TCA_CSUM_PAD))
1b34ec43	595	goto nla_put_failure;
eb4d4065 GB	596
	597	return skb->len;
	598
	599	nla_put_failure:
	600	nlmsg_trim(skb, b);
	601	return -1;
	602	}
	603
ddf97ccd WC	604	static int tcf_csum_walker(struct net net, struct sk_buff skb,
ddf97ccd WC	605	struct netlink_callback *cb, int type,
a85a970a	606	const struct tc_action_ops *ops)
ddf97ccd WC	607	{
	608	struct tc_action_net *tn = net_generic(net, csum_net_id);
	609
a85a970a	610	return tcf_generic_walker(tn, skb, cb, type, ops);
ddf97ccd WC	611	}
ddf97ccd WC	612
a85a970a	613	static int tcf_csum_search(struct net net, struct tc_action *a, u32 index)
ddf97ccd WC	614	{
	615	struct tc_action_net *tn = net_generic(net, csum_net_id);
	616
	617	return tcf_hash_search(tn, a, index);
	618	}
	619
eb4d4065	620	static struct tc_action_ops act_csum_ops = {
0eec32ff	621	.kind = "csum",
0eec32ff	622	.type = TCA_ACT_CSUM,
0eec32ff CG	623	.owner = THIS_MODULE,
	624	.act = tcf_csum,
	625	.dump = tcf_csum_dump,
0eec32ff	626	.init = tcf_csum_init,
ddf97ccd WC	627	.walk = tcf_csum_walker,
ddf97ccd WC	628	.lookup = tcf_csum_search,
a85a970a	629	.size = sizeof(struct tcf_csum),
ddf97ccd WC	630	};
	631
	632	static __net_init int csum_init_net(struct net *net)
	633	{
	634	struct tc_action_net *tn = net_generic(net, csum_net_id);
	635
	636	return tc_action_net_init(tn, &act_csum_ops, CSUM_TAB_MASK);
	637	}
	638
	639	static void __net_exit csum_exit_net(struct net *net)
	640	{
	641	struct tc_action_net *tn = net_generic(net, csum_net_id);
	642
	643	tc_action_net_exit(tn);
	644	}
	645
	646	static struct pernet_operations csum_net_ops = {
	647	.init = csum_init_net,
	648	.exit = csum_exit_net,
	649	.id = &csum_net_id,
	650	.size = sizeof(struct tc_action_net),
eb4d4065 GB	651	};
	652
	653	MODULE_DESCRIPTION("Checksum updating actions");
	654	MODULE_LICENSE("GPL");
	655
	656	static int __init csum_init_module(void)
	657	{
ddf97ccd	658	return tcf_register_action(&act_csum_ops, &csum_net_ops);
eb4d4065 GB	659	}
	660
	661	static void __exit csum_cleanup_module(void)
	662	{
ddf97ccd	663	tcf_unregister_action(&act_csum_ops, &csum_net_ops);
eb4d4065 GB	664	}
	665
	666	module_init(csum_init_module);
	667	module_exit(csum_cleanup_module);