aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/clocksource/timer-sp.h
blob: b2037eb94a41485b6b08bd16ee10e62cabe3bddd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * ARM timer implementation, found in Integrator, Versatile and Realview
 * platforms.  Not all platforms support all registers and bits in these
 * registers, so we mark them with A for Integrator AP, C for Integrator
 * CP, V for Versatile and R for Realview.
 *
 * Integrator AP has 16-bit timers, Integrator CP, Versatile and Realview
 * can have 16-bit or 32-bit selectable via a bit in the control register.
 *
 * Every SP804 contains two identical timers.
 */
#define TIMER_1_BASE	0x00
#define TIMER_2_BASE	0x20

#define TIMER_LOAD	0x00			/* ACVR rw */
#define TIMER_VALUE	0x04			/* ACVR ro */
#define TIMER_CTRL	0x08			/* ACVR rw */
#define TIMER_CTRL_ONESHOT	(1 << 0)	/*  CVR */
#define TIMER_CTRL_32BIT	(1 << 1)	/*  CVR */
#define TIMER_CTRL_DIV1		(0 << 2)	/* ACVR */
#define TIMER_CTRL_DIV16	(1 << 2)	/* ACVR */
#define TIMER_CTRL_DIV256	(2 << 2)	/* ACVR */
#define TIMER_CTRL_IE		(1 << 5)	/*   VR */
#define TIMER_CTRL_PERIODIC	(1 << 6)	/* ACVR */
#define TIMER_CTRL_ENABLE	(1 << 7)	/* ACVR */

#define TIMER_INTCLR	0x0c			/* ACVR wo */
#define TIMER_RIS	0x10			/*  CVR ro */
#define TIMER_MIS	0x14			/*  CVR ro */
#define TIMER_BGLOAD	0x18			/*  CVR rw */
n60' href='#n60'>60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/rhashtable.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/netdevice.h>
#include <linux/if_ether.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/neighbour.h>
#include <net/netfilter/nf_flow_table.h>
#include <net/netfilter/nf_conntrack_acct.h>
/* For layer 4 checksum field offset. */
#include <linux/tcp.h>
#include <linux/udp.h>

static int nf_flow_state_check(struct flow_offload *flow, int proto,
			       struct sk_buff *skb, unsigned int thoff)
{
	struct tcphdr *tcph;

	if (proto != IPPROTO_TCP)
		return 0;

	tcph = (void *)(skb_network_header(skb) + thoff);
	if (unlikely(tcph->fin || tcph->rst)) {
		flow_offload_teardown(flow);
		return -1;
	}

	return 0;
}

static void nf_flow_nat_ip_tcp(struct sk_buff *skb, unsigned int thoff,
			       __be32 addr, __be32 new_addr)
{
	struct tcphdr *tcph;

	tcph = (void *)(skb_network_header(skb) + thoff);
	inet_proto_csum_replace4(&tcph->check, skb, addr, new_addr, true);
}

static void nf_flow_nat_ip_udp(struct sk_buff *skb, unsigned int thoff,
			       __be32 addr, __be32 new_addr)
{
	struct udphdr *udph;

	udph = (void *)(skb_network_header(skb) + thoff);
	if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
		inet_proto_csum_replace4(&udph->check, skb, addr,
					 new_addr, true);
		if (!udph->check)
			udph->check = CSUM_MANGLED_0;
	}
}

static void nf_flow_nat_ip_l4proto(struct sk_buff *skb, struct iphdr *iph,
				   unsigned int thoff, __be32 addr,
				   __be32 new_addr)
{
	switch (iph->protocol) {
	case IPPROTO_TCP:
		nf_flow_nat_ip_tcp(skb, thoff, addr, new_addr);
		break;
	case IPPROTO_UDP:
		nf_flow_nat_ip_udp(skb, thoff, addr, new_addr);
		break;
	}
}

static void nf_flow_snat_ip(const struct flow_offload *flow,
			    struct sk_buff *skb, struct iphdr *iph,
			    unsigned int thoff, enum flow_offload_tuple_dir dir)
{
	__be32 addr, new_addr;

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		addr = iph->saddr;
		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v4.s_addr;
		iph->saddr = new_addr;
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		addr = iph->daddr;
		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v4.s_addr;
		iph->daddr = new_addr;
		break;
	}
	csum_replace4(&iph->check, addr, new_addr);

	nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr);
}

static void nf_flow_dnat_ip(const struct flow_offload *flow,
			    struct sk_buff *skb, struct iphdr *iph,
			    unsigned int thoff, enum flow_offload_tuple_dir dir)
{
	__be32 addr, new_addr;

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		addr = iph->daddr;
		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v4.s_addr;
		iph->daddr = new_addr;
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		addr = iph->saddr;
		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v4.s_addr;
		iph->saddr = new_addr;
		break;
	}
	csum_replace4(&iph->check, addr, new_addr);

	nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr);
}

static void nf_flow_nat_ip(const struct flow_offload *flow, struct sk_buff *skb,
			  unsigned int thoff, enum flow_offload_tuple_dir dir,
			  struct iphdr *iph)
{
	if (test_bit(NF_FLOW_SNAT, &flow->flags)) {
		nf_flow_snat_port(flow, skb, thoff, iph->protocol, dir);
		nf_flow_snat_ip(flow, skb, iph, thoff, dir);
	}
	if (test_bit(NF_FLOW_DNAT, &flow->flags)) {
		nf_flow_dnat_port(flow, skb, thoff, iph->protocol, dir);
		nf_flow_dnat_ip(flow, skb, iph, thoff, dir);
	}
}

static bool ip_has_options(unsigned int thoff)
{
	return thoff != sizeof(struct iphdr);
}

static void nf_flow_tuple_encap(struct sk_buff *skb,
				struct flow_offload_tuple *tuple)
{
	struct vlan_ethhdr *veth;
	struct pppoe_hdr *phdr;
	int i = 0;

	if (skb_vlan_tag_present(skb)) {
		tuple->encap[i].id = skb_vlan_tag_get(skb);
		tuple->encap[i].proto = skb->vlan_proto;
		i++;
	}
	switch (skb->protocol) {
	case htons(ETH_P_8021Q):
		veth = (struct vlan_ethhdr *)skb_mac_header(skb);
		tuple->encap[i].id = ntohs(veth->h_vlan_TCI);
		tuple->encap[i].proto = skb->protocol;
		break;
	case htons(ETH_P_PPP_SES):
		phdr = (struct pppoe_hdr *)skb_mac_header(skb);
		tuple->encap[i].id = ntohs(phdr->sid);
		tuple->encap[i].proto = skb->protocol;
		break;
	}
}

static int nf_flow_tuple_ip(struct sk_buff *skb, const struct net_device *dev,
			    struct flow_offload_tuple *tuple, u32 *hdrsize,
			    u32 offset)
{
	struct flow_ports *ports;
	unsigned int thoff;
	struct iphdr *iph;
	u8 ipproto;

	if (!pskb_may_pull(skb, sizeof(*iph) + offset))
		return -1;

	iph = (struct iphdr *)(skb_network_header(skb) + offset);
	thoff = (iph->ihl * 4);

	if (ip_is_fragment(iph) ||
	    unlikely(ip_has_options(thoff)))
		return -1;

	thoff += offset;

	ipproto = iph->protocol;
	switch (ipproto) {
	case IPPROTO_TCP:
		*hdrsize = sizeof(struct tcphdr);
		break;
	case IPPROTO_UDP:
		*hdrsize = sizeof(struct udphdr);
		break;
#ifdef CONFIG_NF_CT_PROTO_GRE
	case IPPROTO_GRE:
		*hdrsize = sizeof(struct gre_base_hdr);
		break;
#endif
	default:
		return -1;
	}

	if (iph->ttl <= 1)
		return -1;

	if (!pskb_may_pull(skb, thoff + *hdrsize))
		return -1;

	switch (ipproto) {
	case IPPROTO_TCP:
	case IPPROTO_UDP:
		ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
		tuple->src_port		= ports->source;
		tuple->dst_port		= ports->dest;
		break;
	case IPPROTO_GRE: {
		struct gre_base_hdr *greh;

		greh = (struct gre_base_hdr *)(skb_network_header(skb) + thoff);
		if ((greh->flags & GRE_VERSION) != GRE_VERSION_0)
			return -1;
		break;
	}
	}

	iph = (struct iphdr *)(skb_network_header(skb) + offset);

	tuple->src_v4.s_addr	= iph->saddr;
	tuple->dst_v4.s_addr	= iph->daddr;
	tuple->l3proto		= AF_INET;
	tuple->l4proto		= ipproto;
	tuple->iifidx		= dev->ifindex;
	nf_flow_tuple_encap(skb, tuple);

	return 0;
}

/* Based on ip_exceeds_mtu(). */
static bool nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
{
	if (skb->len <= mtu)
		return false;

	if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
		return false;

	return true;
}

static inline bool nf_flow_dst_check(struct flow_offload_tuple *tuple)
{
	if (tuple->xmit_type != FLOW_OFFLOAD_XMIT_NEIGH &&
	    tuple->xmit_type != FLOW_OFFLOAD_XMIT_XFRM)
		return true;

	return dst_check(tuple->dst_cache, tuple->dst_cookie);
}

static unsigned int nf_flow_xmit_xfrm(struct sk_buff *skb,
				      const struct nf_hook_state *state,
				      struct dst_entry *dst)
{
	skb_orphan(skb);
	skb_dst_set_noref(skb, dst);
	dst_output(state->net, state->sk, skb);
	return NF_STOLEN;
}

static bool nf_flow_skb_encap_protocol(const struct sk_buff *skb, __be16 proto,
				       u32 *offset)
{
	struct vlan_ethhdr *veth;

	switch (skb->protocol) {
	case htons(ETH_P_8021Q):
		veth = (struct vlan_ethhdr *)skb_mac_header(skb);
		if (veth->h_vlan_encapsulated_proto == proto) {
			*offset += VLAN_HLEN;
			return true;
		}
		break;
	case htons(ETH_P_PPP_SES):
		if (nf_flow_pppoe_proto(skb) == proto) {
			*offset += PPPOE_SES_HLEN;
			return true;
		}
		break;
	}

	return false;
}

static void nf_flow_encap_pop(struct sk_buff *skb,
			      struct flow_offload_tuple_rhash *tuplehash)
{
	struct vlan_hdr *vlan_hdr;
	int i;

	for (i = 0; i < tuplehash->tuple.encap_num; i++) {
		if (skb_vlan_tag_present(skb)) {
			__vlan_hwaccel_clear_tag(skb);
			continue;
		}
		switch (skb->protocol) {
		case htons(ETH_P_8021Q):
			vlan_hdr = (struct vlan_hdr *)skb->data;
			__skb_pull(skb, VLAN_HLEN);
			vlan_set_encap_proto(skb, vlan_hdr);
			skb_reset_network_header(skb);
			break;
		case htons(ETH_P_PPP_SES):
			skb->protocol = nf_flow_pppoe_proto(skb);
			skb_pull(skb, PPPOE_SES_HLEN);
			skb_reset_network_header(skb);
			break;
		}
	}
}

static unsigned int nf_flow_queue_xmit(struct net *net, struct sk_buff *skb,
				       const struct flow_offload_tuple_rhash *tuplehash,
				       unsigned short type)
{
	struct net_device *outdev;

	outdev = dev_get_by_index_rcu(net, tuplehash->tuple.out.ifidx);
	if (!outdev)
		return NF_DROP;

	skb->dev = outdev;
	dev_hard_header(skb, skb->dev, type, tuplehash->tuple.out.h_dest,
			tuplehash->tuple.out.h_source, skb->len);
	dev_queue_xmit(skb);

	return NF_STOLEN;
}

unsigned int
nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
			const struct nf_hook_state *state)
{
	struct flow_offload_tuple_rhash *tuplehash;
	struct nf_flowtable *flow_table = priv;
	struct flow_offload_tuple tuple = {};
	enum flow_offload_tuple_dir dir;
	struct flow_offload *flow;
	struct net_device *outdev;
	u32 hdrsize, offset = 0;
	unsigned int thoff, mtu;
	struct rtable *rt;
	struct iphdr *iph;
	__be32 nexthop;
	int ret;

	if (skb->protocol != htons(ETH_P_IP) &&
	    !nf_flow_skb_encap_protocol(skb, htons(ETH_P_IP), &offset))
		return NF_ACCEPT;

	if (nf_flow_tuple_ip(skb, state->in, &tuple, &hdrsize, offset) < 0)
		return NF_ACCEPT;

	tuplehash = flow_offload_lookup(flow_table, &tuple);
	if (tuplehash == NULL)
		return NF_ACCEPT;

	dir = tuplehash->tuple.dir;
	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);

	mtu = flow->tuplehash[dir].tuple.mtu + offset;
	if (unlikely(nf_flow_exceeds_mtu(skb, mtu)))
		return NF_ACCEPT;

	iph = (struct iphdr *)(skb_network_header(skb) + offset);
	thoff = (iph->ihl * 4) + offset;
	if (nf_flow_state_check(flow, iph->protocol, skb, thoff))
		return NF_ACCEPT;

	if (!nf_flow_dst_check(&tuplehash->tuple)) {
		flow_offload_teardown(flow);
		return NF_ACCEPT;
	}

	if (skb_try_make_writable(skb, thoff + hdrsize))
		return NF_DROP;

	flow_offload_refresh(flow_table, flow);

	nf_flow_encap_pop(skb, tuplehash);
	thoff -= offset;

	iph = ip_hdr(skb);
	nf_flow_nat_ip(flow, skb, thoff, dir, iph);

	ip_decrease_ttl(iph);
	skb_clear_tstamp(skb);

	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);

	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
		rt = (struct rtable *)tuplehash->tuple.dst_cache;
		memset(skb->cb, 0, sizeof(struct inet_skb_parm));
		IPCB(skb)->iif = skb->dev->ifindex;
		IPCB(skb)->flags = IPSKB_FORWARDED;
		return nf_flow_xmit_xfrm(skb, state, &rt->dst);
	}

	switch (tuplehash->tuple.xmit_type) {
	case FLOW_OFFLOAD_XMIT_NEIGH:
		rt = (struct rtable *)tuplehash->tuple.dst_cache;
		outdev = rt->dst.dev;
		skb->dev = outdev;
		nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
		skb_dst_set_noref(skb, &rt->dst);
		neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb);
		ret = NF_STOLEN;
		break;
	case FLOW_OFFLOAD_XMIT_DIRECT:
		ret = nf_flow_queue_xmit(state->net, skb, tuplehash, ETH_P_IP);
		if (ret == NF_DROP)
			flow_offload_teardown(flow);
		break;
	}

	return ret;
}
EXPORT_SYMBOL_GPL(nf_flow_offload_ip_hook);

static void nf_flow_nat_ipv6_tcp(struct sk_buff *skb, unsigned int thoff,
				 struct in6_addr *addr,
				 struct in6_addr *new_addr,
				 struct ipv6hdr *ip6h)
{
	struct tcphdr *tcph;

	tcph = (void *)(skb_network_header(skb) + thoff);
	inet_proto_csum_replace16(&tcph->check, skb, addr->s6_addr32,
				  new_addr->s6_addr32, true);
}

static void nf_flow_nat_ipv6_udp(struct sk_buff *skb, unsigned int thoff,
				 struct in6_addr *addr,
				 struct in6_addr *new_addr)
{
	struct udphdr *udph;

	udph = (void *)(skb_network_header(skb) + thoff);
	if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
		inet_proto_csum_replace16(&udph->check, skb, addr->s6_addr32,
					  new_addr->s6_addr32, true);
		if (!udph->check)
			udph->check = CSUM_MANGLED_0;
	}
}

static void nf_flow_nat_ipv6_l4proto(struct sk_buff *skb, struct ipv6hdr *ip6h,
				     unsigned int thoff, struct in6_addr *addr,
				     struct in6_addr *new_addr)
{
	switch (ip6h->nexthdr) {
	case IPPROTO_TCP:
		nf_flow_nat_ipv6_tcp(skb, thoff, addr, new_addr, ip6h);
		break;
	case IPPROTO_UDP:
		nf_flow_nat_ipv6_udp(skb, thoff, addr, new_addr);
		break;
	}
}

static void nf_flow_snat_ipv6(const struct flow_offload *flow,
			      struct sk_buff *skb, struct ipv6hdr *ip6h,
			      unsigned int thoff,
			      enum flow_offload_tuple_dir dir)
{
	struct in6_addr addr, new_addr;

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		addr = ip6h->saddr;
		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v6;
		ip6h->saddr = new_addr;
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		addr = ip6h->daddr;
		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v6;
		ip6h->daddr = new_addr;
		break;
	}

	nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr);
}

static void nf_flow_dnat_ipv6(const struct flow_offload *flow,
			      struct sk_buff *skb, struct ipv6hdr *ip6h,
			      unsigned int thoff,
			      enum flow_offload_tuple_dir dir)
{
	struct in6_addr addr, new_addr;

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		addr = ip6h->daddr;
		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v6;
		ip6h->daddr = new_addr;
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		addr = ip6h->saddr;
		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v6;
		ip6h->saddr = new_addr;
		break;
	}

	nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr);
}

static void nf_flow_nat_ipv6(const struct flow_offload *flow,
			     struct sk_buff *skb,
			     enum flow_offload_tuple_dir dir,
			     struct ipv6hdr *ip6h)
{
	unsigned int thoff = sizeof(*ip6h);

	if (test_bit(NF_FLOW_SNAT, &flow->flags)) {
		nf_flow_snat_port(flow, skb, thoff, ip6h->nexthdr, dir);
		nf_flow_snat_ipv6(flow, skb, ip6h, thoff, dir);
	}
	if (test_bit(NF_FLOW_DNAT, &flow->flags)) {
		nf_flow_dnat_port(flow, skb, thoff, ip6h->nexthdr, dir);
		nf_flow_dnat_ipv6(flow, skb, ip6h, thoff, dir);
	}
}

static int nf_flow_tuple_ipv6(struct sk_buff *skb, const struct net_device *dev,
			      struct flow_offload_tuple *tuple, u32 *hdrsize,
			      u32 offset)
{
	struct flow_ports *ports;
	struct ipv6hdr *ip6h;
	unsigned int thoff;
	u8 nexthdr;

	thoff = sizeof(*ip6h) + offset;
	if (!pskb_may_pull(skb, thoff))
		return -1;

	ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset);

	nexthdr = ip6h->nexthdr;
	switch (nexthdr) {
	case IPPROTO_TCP:
		*hdrsize = sizeof(struct tcphdr);
		break;
	case IPPROTO_UDP:
		*hdrsize = sizeof(struct udphdr);
		break;
#ifdef CONFIG_NF_CT_PROTO_GRE
	case IPPROTO_GRE:
		*hdrsize = sizeof(struct gre_base_hdr);
		break;
#endif
	default:
		return -1;
	}

	if (ip6h->hop_limit <= 1)
		return -1;

	if (!pskb_may_pull(skb, thoff + *hdrsize))
		return -1;

	switch (nexthdr) {
	case IPPROTO_TCP:
	case IPPROTO_UDP:
		ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
		tuple->src_port		= ports->source;
		tuple->dst_port		= ports->dest;
		break;
	case IPPROTO_GRE: {
		struct gre_base_hdr *greh;

		greh = (struct gre_base_hdr *)(skb_network_header(skb) + thoff);
		if ((greh->flags & GRE_VERSION) != GRE_VERSION_0)
			return -1;
		break;
	}
	}

	ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset);

	tuple->src_v6		= ip6h->saddr;
	tuple->dst_v6		= ip6h->daddr;
	tuple->l3proto		= AF_INET6;
	tuple->l4proto		= nexthdr;
	tuple->iifidx		= dev->ifindex;
	nf_flow_tuple_encap(skb, tuple);

	return 0;
}

unsigned int
nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
			  const struct nf_hook_state *state)
{
	struct flow_offload_tuple_rhash *tuplehash;
	struct nf_flowtable *flow_table = priv;
	struct flow_offload_tuple tuple = {};
	enum flow_offload_tuple_dir dir;
	const struct in6_addr *nexthop;
	struct flow_offload *flow;
	struct net_device *outdev;
	unsigned int thoff, mtu;
	u32 hdrsize, offset = 0;
	struct ipv6hdr *ip6h;
	struct rt6_info *rt;
	int ret;

	if (skb->protocol != htons(ETH_P_IPV6) &&
	    !nf_flow_skb_encap_protocol(skb, htons(ETH_P_IPV6), &offset))
		return NF_ACCEPT;

	if (nf_flow_tuple_ipv6(skb, state->in, &tuple, &hdrsize, offset) < 0)
		return NF_ACCEPT;

	tuplehash = flow_offload_lookup(flow_table, &tuple);
	if (tuplehash == NULL)
		return NF_ACCEPT;

	dir = tuplehash->tuple.dir;
	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);

	mtu = flow->tuplehash[dir].tuple.mtu + offset;
	if (unlikely(nf_flow_exceeds_mtu(skb, mtu)))
		return NF_ACCEPT;

	ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset);
	thoff = sizeof(*ip6h) + offset;
	if (nf_flow_state_check(flow, ip6h->nexthdr, skb, thoff))
		return NF_ACCEPT;

	if (!nf_flow_dst_check(&tuplehash->tuple)) {
		flow_offload_teardown(flow);
		return NF_ACCEPT;
	}

	if (skb_try_make_writable(skb, thoff + hdrsize))
		return NF_DROP;

	flow_offload_refresh(flow_table, flow);

	nf_flow_encap_pop(skb, tuplehash);

	ip6h = ipv6_hdr(skb);
	nf_flow_nat_ipv6(flow, skb, dir, ip6h);

	ip6h->hop_limit--;
	skb_clear_tstamp(skb);

	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);

	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
		rt = (struct rt6_info *)tuplehash->tuple.dst_cache;
		memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
		IP6CB(skb)->iif = skb->dev->ifindex;
		IP6CB(skb)->flags = IP6SKB_FORWARDED;
		return nf_flow_xmit_xfrm(skb, state, &rt->dst);
	}

	switch (tuplehash->tuple.xmit_type) {
	case FLOW_OFFLOAD_XMIT_NEIGH:
		rt = (struct rt6_info *)tuplehash->tuple.dst_cache;
		outdev = rt->dst.dev;
		skb->dev = outdev;
		nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6);
		skb_dst_set_noref(skb, &rt->dst);
		neigh_xmit(NEIGH_ND_TABLE, outdev, nexthop, skb);
		ret = NF_STOLEN;
		break;
	case FLOW_OFFLOAD_XMIT_DIRECT:
		ret = nf_flow_queue_xmit(state->net, skb, tuplehash, ETH_P_IPV6);
		if (ret == NF_DROP)
			flow_offload_teardown(flow);
		break;
	}

	return ret;
}
EXPORT_SYMBOL_GPL(nf_flow_offload_ipv6_hook);