[GitHub/exynos8895/android_kernel_samsung_universal8895.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/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 int tcf_csum_init(struct net *n, struct nlattr *nla, struct nlattr *est,
			 struct tc_action *a, int ovr, int bind)
{
	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);
	if (err < 0)
		return err;

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

	if (!tcf_hash_check(parm->index, a, bind)) {
		ret = tcf_hash_create(parm->index, est, a, sizeof(*p),
				      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(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;

	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;

	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;

	/*
	 * 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;

	/*
	 * 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_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;
	}

	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;
		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 = a->priv;
	int action;
	u32 update_flags;

	spin_lock(&p->tcf_lock);
	p->tcf_tm.lastuse = jiffies;
	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 = a->priv;
	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;
	t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
	t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
	t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
	if (nla_put(skb, TCA_CSUM_TM, sizeof(t), &t))
		goto nla_put_failure;

	return skb->len;

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

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,
};

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

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

static void __exit csum_cleanup_module(void)
{
	tcf_unregister_action(&act_csum_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>
eb4d4065 GB	33
	34	#include <net/act_api.h>
	35
	36	#include <linux/tc_act/tc_csum.h>
	37	#include <net/tc_act/tc_csum.h>
	38
	39	#define CSUM_TAB_MASK 15
eb4d4065 GB	40
	41	static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
	42	[TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
	43	};
	44
c1b52739	45	static int tcf_csum_init(struct net n, struct nlattr nla, struct nlattr *est,
eb4d4065 GB	46	struct tc_action *a, int ovr, int bind)
	47	{
	48	struct nlattr *tb[TCA_CSUM_MAX + 1];
	49	struct tc_csum *parm;
eb4d4065 GB	50	struct tcf_csum *p;
	51	int ret = 0, err;
	52
	53	if (nla == NULL)
	54	return -EINVAL;
	55
cc7ec456	56	err = nla_parse_nested(tb, TCA_CSUM_MAX, nla, csum_policy);
eb4d4065 GB	57	if (err < 0)
	58	return err;
	59
	60	if (tb[TCA_CSUM_PARMS] == NULL)
	61	return -EINVAL;
	62	parm = nla_data(tb[TCA_CSUM_PARMS]);
	63
86062033	64	if (!tcf_hash_check(parm->index, a, bind)) {
519c818e ED	65	ret = tcf_hash_create(parm->index, est, a, sizeof(*p),
519c818e ED	66	bind, false);
86062033 WC	67	if (ret)
86062033 WC	68	return ret;
eb4d4065 GB	69	ret = ACT_P_CREATED;
eb4d4065 GB	70	} else {
1a29321e JHS	71	if (bind)/* dont override defaults */
1a29321e JHS	72	return 0;
86062033	73	tcf_hash_release(a, bind);
1a29321e	74	if (!ovr)
eb4d4065	75	return -EEXIST;
eb4d4065 GB	76	}
eb4d4065 GB	77
86062033	78	p = to_tcf_csum(a);
eb4d4065 GB	79	spin_lock_bh(&p->tcf_lock);
	80	p->tcf_action = parm->action;
	81	p->update_flags = parm->update_flags;
	82	spin_unlock_bh(&p->tcf_lock);
	83
	84	if (ret == ACT_P_CREATED)
86062033	85	tcf_hash_insert(a);
eb4d4065 GB	86
	87	return ret;
	88	}
	89
eb4d4065 GB	90	/**
	91	* tcf_csum_skb_nextlayer - Get next layer pointer
	92	* @skb: sk_buff to use
	93	* @ihl: previous summed headers length
	94	* @ipl: complete packet length
	95	* @jhl: next header length
	96	*
	97	* Check the expected next layer availability in the specified sk_buff.
	98	* Return the next layer pointer if pass, NULL otherwise.
	99	*/
	100	static void tcf_csum_skb_nextlayer(struct sk_buff skb,
	101	unsigned int ihl, unsigned int ipl,
	102	unsigned int jhl)
	103	{
	104	int ntkoff = skb_network_offset(skb);
	105	int hl = ihl + jhl;
	106
	107	if (!pskb_may_pull(skb, ipl + ntkoff) \|\| (ipl < hl) \|\|
b30cc5b1	108	skb_try_make_writable(skb, hl + ntkoff))
eb4d4065 GB	109	return NULL;
	110	else
	111	return (void *)(skb_network_header(skb) + ihl);
	112	}
	113
	114	static int tcf_csum_ipv4_icmp(struct sk_buff *skb,
	115	unsigned int ihl, unsigned int ipl)
	116	{
	117	struct icmphdr *icmph;
	118
	119	icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
	120	if (icmph == NULL)
	121	return 0;
	122
	123	icmph->checksum = 0;
	124	skb->csum = csum_partial(icmph, ipl - ihl, 0);
	125	icmph->checksum = csum_fold(skb->csum);
	126
	127	skb->ip_summed = CHECKSUM_NONE;
	128
	129	return 1;
	130	}
	131
	132	static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
	133	unsigned int ihl, unsigned int ipl)
	134	{
	135	struct igmphdr *igmph;
	136
	137	igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
	138	if (igmph == NULL)
	139	return 0;
	140
	141	igmph->csum = 0;
	142	skb->csum = csum_partial(igmph, ipl - ihl, 0);
	143	igmph->csum = csum_fold(skb->csum);
	144
	145	skb->ip_summed = CHECKSUM_NONE;
	146
	147	return 1;
	148	}
	149
d14a489a	150	static int tcf_csum_ipv6_icmp(struct sk_buff *skb,
eb4d4065 GB	151	unsigned int ihl, unsigned int ipl)
	152	{
	153	struct icmp6hdr *icmp6h;
d14a489a	154	const struct ipv6hdr *ip6h;
eb4d4065 GB	155
	156	icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
	157	if (icmp6h == NULL)
	158	return 0;
	159
d14a489a	160	ip6h = ipv6_hdr(skb);
eb4d4065 GB	161	icmp6h->icmp6_cksum = 0;
	162	skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
	163	icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
	164	ipl - ihl, IPPROTO_ICMPV6,
	165	skb->csum);
	166
	167	skb->ip_summed = CHECKSUM_NONE;
	168
	169	return 1;
	170	}
	171
d14a489a	172	static int tcf_csum_ipv4_tcp(struct sk_buff *skb,
eb4d4065 GB	173	unsigned int ihl, unsigned int ipl)
	174	{
	175	struct tcphdr *tcph;
d14a489a	176	const struct iphdr *iph;
eb4d4065 GB	177
	178	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
	179	if (tcph == NULL)
	180	return 0;
	181
d14a489a	182	iph = ip_hdr(skb);
eb4d4065 GB	183	tcph->check = 0;
	184	skb->csum = csum_partial(tcph, ipl - ihl, 0);
	185	tcph->check = tcp_v4_check(ipl - ihl,
	186	iph->saddr, iph->daddr, skb->csum);
	187
	188	skb->ip_summed = CHECKSUM_NONE;
	189
	190	return 1;
	191	}
	192
d14a489a	193	static int tcf_csum_ipv6_tcp(struct sk_buff *skb,
eb4d4065 GB	194	unsigned int ihl, unsigned int ipl)
	195	{
	196	struct tcphdr *tcph;
d14a489a	197	const struct ipv6hdr *ip6h;
eb4d4065 GB	198
	199	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
	200	if (tcph == NULL)
	201	return 0;
	202
d14a489a	203	ip6h = ipv6_hdr(skb);
eb4d4065 GB	204	tcph->check = 0;
	205	skb->csum = csum_partial(tcph, ipl - ihl, 0);
	206	tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
	207	ipl - ihl, IPPROTO_TCP,
	208	skb->csum);
	209
	210	skb->ip_summed = CHECKSUM_NONE;
	211
	212	return 1;
	213	}
	214
d14a489a	215	static int tcf_csum_ipv4_udp(struct sk_buff *skb,
eb4d4065 GB	216	unsigned int ihl, unsigned int ipl, int udplite)
	217	{
	218	struct udphdr *udph;
d14a489a	219	const struct iphdr *iph;
eb4d4065 GB	220	u16 ul;
eb4d4065 GB	221
0eec32ff CG	222	/*
	223	* Support both UDP and UDPLITE checksum algorithms, Don't use
	224	* udph->len to get the real length without any protocol check,
eb4d4065 GB	225	* UDPLITE uses udph->len for another thing,
	226	* Use iph->tot_len, or just ipl.
	227	*/
	228
	229	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
	230	if (udph == NULL)
	231	return 0;
	232
d14a489a	233	iph = ip_hdr(skb);
eb4d4065 GB	234	ul = ntohs(udph->len);
	235
	236	if (udplite \|\| udph->check) {
	237
	238	udph->check = 0;
	239
	240	if (udplite) {
	241	if (ul == 0)
	242	skb->csum = csum_partial(udph, ipl - ihl, 0);
eb4d4065 GB	243	else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
eb4d4065 GB	244	skb->csum = csum_partial(udph, ul, 0);
eb4d4065 GB	245	else
	246	goto ignore_obscure_skb;
	247	} else {
	248	if (ul != ipl - ihl)
	249	goto ignore_obscure_skb;
	250
	251	skb->csum = csum_partial(udph, ul, 0);
	252	}
	253
	254	udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
	255	ul, iph->protocol,
	256	skb->csum);
	257
	258	if (!udph->check)
	259	udph->check = CSUM_MANGLED_0;
	260	}
	261
	262	skb->ip_summed = CHECKSUM_NONE;
	263
	264	ignore_obscure_skb:
	265	return 1;
	266	}
	267
d14a489a	268	static int tcf_csum_ipv6_udp(struct sk_buff *skb,
eb4d4065 GB	269	unsigned int ihl, unsigned int ipl, int udplite)
	270	{
	271	struct udphdr *udph;
d14a489a	272	const struct ipv6hdr *ip6h;
eb4d4065 GB	273	u16 ul;
eb4d4065 GB	274
0eec32ff CG	275	/*
	276	* Support both UDP and UDPLITE checksum algorithms, Don't use
	277	* udph->len to get the real length without any protocol check,
eb4d4065 GB	278	* UDPLITE uses udph->len for another thing,
	279	* Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
	280	*/
	281
	282	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
	283	if (udph == NULL)
	284	return 0;
	285
d14a489a	286	ip6h = ipv6_hdr(skb);
eb4d4065 GB	287	ul = ntohs(udph->len);
	288
	289	udph->check = 0;
	290
	291	if (udplite) {
	292	if (ul == 0)
	293	skb->csum = csum_partial(udph, ipl - ihl, 0);
	294
	295	else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
	296	skb->csum = csum_partial(udph, ul, 0);
	297
	298	else
	299	goto ignore_obscure_skb;
	300	} else {
	301	if (ul != ipl - ihl)
	302	goto ignore_obscure_skb;
	303
	304	skb->csum = csum_partial(udph, ul, 0);
	305	}
	306
	307	udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
	308	udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
	309	skb->csum);
	310
	311	if (!udph->check)
	312	udph->check = CSUM_MANGLED_0;
	313
	314	skb->ip_summed = CHECKSUM_NONE;
	315
	316	ignore_obscure_skb:
	317	return 1;
	318	}
	319
	320	static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
	321	{
d14a489a	322	const struct iphdr *iph;
eb4d4065 GB	323	int ntkoff;
	324
	325	ntkoff = skb_network_offset(skb);
	326
	327	if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
	328	goto fail;
	329
	330	iph = ip_hdr(skb);
	331
	332	switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
	333	case IPPROTO_ICMP:
	334	if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
0eec32ff CG	335	if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
0eec32ff CG	336	ntohs(iph->tot_len)))
eb4d4065 GB	337	goto fail;
	338	break;
	339	case IPPROTO_IGMP:
	340	if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
0eec32ff CG	341	if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
0eec32ff CG	342	ntohs(iph->tot_len)))
eb4d4065 GB	343	goto fail;
	344	break;
	345	case IPPROTO_TCP:
	346	if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
d14a489a	347	if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
0eec32ff	348	ntohs(iph->tot_len)))
eb4d4065 GB	349	goto fail;
	350	break;
	351	case IPPROTO_UDP:
	352	if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
d14a489a	353	if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
0eec32ff	354	ntohs(iph->tot_len), 0))
eb4d4065 GB	355	goto fail;
	356	break;
	357	case IPPROTO_UDPLITE:
	358	if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
d14a489a	359	if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
0eec32ff	360	ntohs(iph->tot_len), 1))
eb4d4065 GB	361	goto fail;
	362	break;
	363	}
	364
	365	if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
b30cc5b1	366	if (skb_try_make_writable(skb, sizeof(*iph) + ntkoff))
eb4d4065 GB	367	goto fail;
eb4d4065 GB	368
d14a489a	369	ip_send_check(ip_hdr(skb));
eb4d4065 GB	370	}
	371
	372	return 1;
	373
	374	fail:
	375	return 0;
	376	}
	377
	378	static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh,
0eec32ff	379	unsigned int ixhl, unsigned int *pl)
eb4d4065 GB	380	{
	381	int off, len, optlen;
	382	unsigned char xh = (void )ip6xh;
	383
	384	off = sizeof(*ip6xh);
	385	len = ixhl - off;
	386
	387	while (len > 1) {
0eec32ff	388	switch (xh[off]) {
1de5a71c	389	case IPV6_TLV_PAD1:
eb4d4065 GB	390	optlen = 1;
	391	break;
	392	case IPV6_TLV_JUMBO:
	393	optlen = xh[off + 1] + 2;
	394	if (optlen != 6 \|\| len < 6 \|\| (off & 3) != 2)
	395	/* wrong jumbo option length/alignment */
	396	return 0;
	397	pl = ntohl((__be32 *)(xh + off + 2));
	398	goto done;
	399	default:
	400	optlen = xh[off + 1] + 2;
	401	if (optlen > len)
	402	/* ignore obscure options */
	403	goto done;
	404	break;
	405	}
	406	off += optlen;
	407	len -= optlen;
	408	}
	409
	410	done:
	411	return 1;
	412	}
	413
	414	static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
	415	{
	416	struct ipv6hdr *ip6h;
	417	struct ipv6_opt_hdr *ip6xh;
	418	unsigned int hl, ixhl;
	419	unsigned int pl;
	420	int ntkoff;
	421	u8 nexthdr;
	422
	423	ntkoff = skb_network_offset(skb);
	424
	425	hl = sizeof(*ip6h);
	426
	427	if (!pskb_may_pull(skb, hl + ntkoff))
	428	goto fail;
	429
	430	ip6h = ipv6_hdr(skb);
	431
	432	pl = ntohs(ip6h->payload_len);
	433	nexthdr = ip6h->nexthdr;
	434
	435	do {
	436	switch (nexthdr) {
	437	case NEXTHDR_FRAGMENT:
	438	goto ignore_skb;
	439	case NEXTHDR_ROUTING:
	440	case NEXTHDR_HOP:
	441	case NEXTHDR_DEST:
	442	if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
	443	goto fail;
	444	ip6xh = (void *)(skb_network_header(skb) + hl);
	445	ixhl = ipv6_optlen(ip6xh);
	446	if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
	447	goto fail;
d14a489a	448	ip6xh = (void *)(skb_network_header(skb) + hl);
eb4d4065 GB	449	if ((nexthdr == NEXTHDR_HOP) &&
	450	!(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
	451	goto fail;
	452	nexthdr = ip6xh->nexthdr;
	453	hl += ixhl;
	454	break;
	455	case IPPROTO_ICMPV6:
	456	if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
d14a489a	457	if (!tcf_csum_ipv6_icmp(skb,
eb4d4065 GB	458	hl, pl + sizeof(*ip6h)))
	459	goto fail;
	460	goto done;
	461	case IPPROTO_TCP:
	462	if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
d14a489a	463	if (!tcf_csum_ipv6_tcp(skb,
eb4d4065 GB	464	hl, pl + sizeof(*ip6h)))
	465	goto fail;
	466	goto done;
	467	case IPPROTO_UDP:
	468	if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
d14a489a	469	if (!tcf_csum_ipv6_udp(skb, hl,
0eec32ff	470	pl + sizeof(*ip6h), 0))
eb4d4065 GB	471	goto fail;
	472	goto done;
	473	case IPPROTO_UDPLITE:
	474	if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
d14a489a	475	if (!tcf_csum_ipv6_udp(skb, hl,
0eec32ff	476	pl + sizeof(*ip6h), 1))
eb4d4065 GB	477	goto fail;
	478	goto done;
	479	default:
	480	goto ignore_skb;
	481	}
	482	} while (pskb_may_pull(skb, hl + 1 + ntkoff));
	483
	484	done:
	485	ignore_skb:
	486	return 1;
	487
	488	fail:
	489	return 0;
	490	}
	491
	492	static int tcf_csum(struct sk_buff *skb,
dc7f9f6e	493	const struct tc_action a, struct tcf_result res)
eb4d4065 GB	494	{
	495	struct tcf_csum *p = a->priv;
	496	int action;
	497	u32 update_flags;
	498
	499	spin_lock(&p->tcf_lock);
	500	p->tcf_tm.lastuse = jiffies;
bfe0d029	501	bstats_update(&p->tcf_bstats, skb);
eb4d4065 GB	502	action = p->tcf_action;
	503	update_flags = p->update_flags;
	504	spin_unlock(&p->tcf_lock);
	505
	506	if (unlikely(action == TC_ACT_SHOT))
	507	goto drop;
	508
d8b9605d	509	switch (tc_skb_protocol(skb)) {
eb4d4065 GB	510	case cpu_to_be16(ETH_P_IP):
	511	if (!tcf_csum_ipv4(skb, update_flags))
	512	goto drop;
	513	break;
	514	case cpu_to_be16(ETH_P_IPV6):
	515	if (!tcf_csum_ipv6(skb, update_flags))
	516	goto drop;
	517	break;
	518	}
	519
	520	return action;
	521
	522	drop:
	523	spin_lock(&p->tcf_lock);
	524	p->tcf_qstats.drops++;
	525	spin_unlock(&p->tcf_lock);
	526	return TC_ACT_SHOT;
	527	}
	528
	529	static int tcf_csum_dump(struct sk_buff *skb,
	530	struct tc_action *a, int bind, int ref)
	531	{
	532	unsigned char *b = skb_tail_pointer(skb);
	533	struct tcf_csum *p = a->priv;
	534	struct tc_csum opt = {
	535	.update_flags = p->update_flags,
eb4d4065 GB	536	.index = p->tcf_index,
	537	.action = p->tcf_action,
	538	.refcnt = p->tcf_refcnt - ref,
	539	.bindcnt = p->tcf_bindcnt - bind,
	540	};
	541	struct tcf_t t;
	542
1b34ec43 DM	543	if (nla_put(skb, TCA_CSUM_PARMS, sizeof(opt), &opt))
1b34ec43 DM	544	goto nla_put_failure;
eb4d4065 GB	545	t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
	546	t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
	547	t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
1b34ec43 DM	548	if (nla_put(skb, TCA_CSUM_TM, sizeof(t), &t))
1b34ec43 DM	549	goto nla_put_failure;
eb4d4065 GB	550
	551	return skb->len;
	552
	553	nla_put_failure:
	554	nlmsg_trim(skb, b);
	555	return -1;
	556	}
	557
	558	static struct tc_action_ops act_csum_ops = {
0eec32ff	559	.kind = "csum",
0eec32ff	560	.type = TCA_ACT_CSUM,
0eec32ff CG	561	.owner = THIS_MODULE,
	562	.act = tcf_csum,
	563	.dump = tcf_csum_dump,
0eec32ff	564	.init = tcf_csum_init,
eb4d4065 GB	565	};
	566
	567	MODULE_DESCRIPTION("Checksum updating actions");
	568	MODULE_LICENSE("GPL");
	569
	570	static int __init csum_init_module(void)
	571	{
4f1e9d89	572	return tcf_register_action(&act_csum_ops, CSUM_TAB_MASK);
eb4d4065 GB	573	}
	574
	575	static void __exit csum_cleanup_module(void)
	576	{
	577	tcf_unregister_action(&act_csum_ops);
	578	}
	579
	580	module_init(csum_init_module);
	581	module_exit(csum_cleanup_module);