[linux-2.6-block.git] / net / ipv6 / ip6_offload.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	IPV6 GSO/GRO offload support
 *	Linux INET6 implementation
 */

#include <linux/kernel.h>
#include <linux/socket.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/printk.h>

#include <net/protocol.h>
#include <net/ipv6.h>
#include <net/inet_common.h>
#include <net/tcp.h>
#include <net/udp.h>

#include "ip6_offload.h"

/* All GRO functions are always builtin, except UDP over ipv6, which lays in
 * ipv6 module, as it depends on UDPv6 lookup function, so we need special care
 * when ipv6 is built as a module
 */
#if IS_BUILTIN(CONFIG_IPV6)
#define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__)
#else
#define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
#endif

#define indirect_call_gro_receive_l4(f2, f1, cb, head, skb)	\
({								\
	unlikely(gro_recursion_inc_test(skb)) ?			\
		NAPI_GRO_CB(skb)->flush |= 1, NULL :		\
		INDIRECT_CALL_L4(cb, f2, f1, head, skb);	\
})

static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
{
	const struct net_offload *ops = NULL;

	for (;;) {
		struct ipv6_opt_hdr *opth;
		int len;

		if (proto != NEXTHDR_HOP) {
			ops = rcu_dereference(inet6_offloads[proto]);

			if (unlikely(!ops))
				break;

			if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
				break;
		}

		if (unlikely(!pskb_may_pull(skb, 8)))
			break;

		opth = (void *)skb->data;
		len = ipv6_optlen(opth);

		if (unlikely(!pskb_may_pull(skb, len)))
			break;

		opth = (void *)skb->data;
		proto = opth->nexthdr;
		__skb_pull(skb, len);
	}

	return proto;
}

static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
	netdev_features_t features)
{
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	struct ipv6hdr *ipv6h;
	const struct net_offload *ops;
	int proto;
	struct frag_hdr *fptr;
	unsigned int payload_len;
	u8 *prevhdr;
	int offset = 0;
	bool encap, udpfrag;
	int nhoff;
	bool gso_partial;

	skb_reset_network_header(skb);
	nhoff = skb_network_header(skb) - skb_mac_header(skb);
	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
		goto out;

	encap = SKB_GSO_CB(skb)->encap_level > 0;
	if (encap)
		features &= skb->dev->hw_enc_features;
	SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);

	ipv6h = ipv6_hdr(skb);
	__skb_pull(skb, sizeof(*ipv6h));
	segs = ERR_PTR(-EPROTONOSUPPORT);

	proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);

	if (skb->encapsulation &&
	    skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6))
		udpfrag = proto == IPPROTO_UDP && encap &&
			  (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
	else
		udpfrag = proto == IPPROTO_UDP && !skb->encapsulation &&
			  (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);

	ops = rcu_dereference(inet6_offloads[proto]);
	if (likely(ops && ops->callbacks.gso_segment)) {
		skb_reset_transport_header(skb);
		segs = ops->callbacks.gso_segment(skb, features);
	}

	if (IS_ERR_OR_NULL(segs))
		goto out;

	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);

	for (skb = segs; skb; skb = skb->next) {
		ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
		if (gso_partial && skb_is_gso(skb))
			payload_len = skb_shinfo(skb)->gso_size +
				      SKB_GSO_CB(skb)->data_offset +
				      skb->head - (unsigned char *)(ipv6h + 1);
		else
			payload_len = skb->len - nhoff - sizeof(*ipv6h);
		ipv6h->payload_len = htons(payload_len);
		skb->network_header = (u8 *)ipv6h - skb->head;
		skb_reset_mac_len(skb);

		if (udpfrag) {
			int err = ip6_find_1stfragopt(skb, &prevhdr);
			if (err < 0) {
				kfree_skb_list(segs);
				return ERR_PTR(err);
			}
			fptr = (struct frag_hdr *)((u8 *)ipv6h + err);
			fptr->frag_off = htons(offset);
			if (skb->next)
				fptr->frag_off |= htons(IP6_MF);
			offset += (ntohs(ipv6h->payload_len) -
				   sizeof(struct frag_hdr));
		}
		if (encap)
			skb_reset_inner_headers(skb);
	}

out:
	return segs;
}

/* Return the total length of all the extension hdrs, following the same
 * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.
 */
static int ipv6_exthdrs_len(struct ipv6hdr *iph,
			    const struct net_offload **opps)
{
	struct ipv6_opt_hdr *opth = (void *)iph;
	int len = 0, proto, optlen = sizeof(*iph);

	proto = iph->nexthdr;
	for (;;) {
		if (proto != NEXTHDR_HOP) {
			*opps = rcu_dereference(inet6_offloads[proto]);
			if (unlikely(!(*opps)))
				break;
			if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
				break;
		}
		opth = (void *)opth + optlen;
		optlen = ipv6_optlen(opth);
		len += optlen;
		proto = opth->nexthdr;
	}
	return len;
}

INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
							 struct sk_buff *skb)
{
	const struct net_offload *ops;
	struct sk_buff *pp = NULL;
	struct sk_buff *p;
	struct ipv6hdr *iph;
	unsigned int nlen;
	unsigned int hlen;
	unsigned int off;
	u16 flush = 1;
	int proto;

	off = skb_gro_offset(skb);
	hlen = off + sizeof(*iph);
	iph = skb_gro_header_fast(skb, off);
	if (skb_gro_header_hard(skb, hlen)) {
		iph = skb_gro_header_slow(skb, hlen, off);
		if (unlikely(!iph))
			goto out;
	}

	skb_set_network_header(skb, off);
	skb_gro_pull(skb, sizeof(*iph));
	skb_set_transport_header(skb, skb_gro_offset(skb));

	flush += ntohs(iph->payload_len) != skb_gro_len(skb);

	rcu_read_lock();
	proto = iph->nexthdr;
	ops = rcu_dereference(inet6_offloads[proto]);
	if (!ops || !ops->callbacks.gro_receive) {
		__pskb_pull(skb, skb_gro_offset(skb));
		skb_gro_frag0_invalidate(skb);
		proto = ipv6_gso_pull_exthdrs(skb, proto);
		skb_gro_pull(skb, -skb_transport_offset(skb));
		skb_reset_transport_header(skb);
		__skb_push(skb, skb_gro_offset(skb));

		ops = rcu_dereference(inet6_offloads[proto]);
		if (!ops || !ops->callbacks.gro_receive)
			goto out_unlock;

		iph = ipv6_hdr(skb);
	}

	NAPI_GRO_CB(skb)->proto = proto;

	flush--;
	nlen = skb_network_header_len(skb);

	list_for_each_entry(p, head, list) {
		const struct ipv6hdr *iph2;
		__be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */

		if (!NAPI_GRO_CB(p)->same_flow)
			continue;

		iph2 = (struct ipv6hdr *)(p->data + off);
		first_word = *(__be32 *)iph ^ *(__be32 *)iph2;

		/* All fields must match except length and Traffic Class.
		 * XXX skbs on the gro_list have all been parsed and pulled
		 * already so we don't need to compare nlen
		 * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))
		 * memcmp() alone below is sufficient, right?
		 */
		 if ((first_word & htonl(0xF00FFFFF)) ||
		    !ipv6_addr_equal(&iph->saddr, &iph2->saddr) ||
		    !ipv6_addr_equal(&iph->daddr, &iph2->daddr) ||
		    *(u16 *)&iph->nexthdr != *(u16 *)&iph2->nexthdr) {
not_same_flow:
			NAPI_GRO_CB(p)->same_flow = 0;
			continue;
		}
		if (unlikely(nlen > sizeof(struct ipv6hdr))) {
			if (memcmp(iph + 1, iph2 + 1,
				   nlen - sizeof(struct ipv6hdr)))
				goto not_same_flow;
		}
		/* flush if Traffic Class fields are different */
		NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000));
		NAPI_GRO_CB(p)->flush |= flush;

		/* If the previous IP ID value was based on an atomic
		 * datagram we can overwrite the value and ignore it.
		 */
		if (NAPI_GRO_CB(skb)->is_atomic)
			NAPI_GRO_CB(p)->flush_id = 0;
	}

	NAPI_GRO_CB(skb)->is_atomic = true;
	NAPI_GRO_CB(skb)->flush |= flush;

	skb_gro_postpull_rcsum(skb, iph, nlen);

	pp = indirect_call_gro_receive_l4(tcp6_gro_receive, udp6_gro_receive,
					 ops->callbacks.gro_receive, head, skb);

out_unlock:
	rcu_read_unlock();

out:
	skb_gro_flush_final(skb, pp, flush);

	return pp;
}

static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
					      struct sk_buff *skb)
{
	/* Common GRO receive for SIT and IP6IP6 */

	if (NAPI_GRO_CB(skb)->encap_mark) {
		NAPI_GRO_CB(skb)->flush = 1;
		return NULL;
	}

	NAPI_GRO_CB(skb)->encap_mark = 1;

	return ipv6_gro_receive(head, skb);
}

static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
					  struct sk_buff *skb)
{
	/* Common GRO receive for SIT and IP6IP6 */

	if (NAPI_GRO_CB(skb)->encap_mark) {
		NAPI_GRO_CB(skb)->flush = 1;
		return NULL;
	}

	NAPI_GRO_CB(skb)->encap_mark = 1;

	return inet_gro_receive(head, skb);
}

INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
{
	const struct net_offload *ops;
	struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + nhoff);
	int err = -ENOSYS;

	if (skb->encapsulation) {
		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
		skb_set_inner_network_header(skb, nhoff);
	}

	iph->payload_len = htons(skb->len - nhoff - sizeof(*iph));

	rcu_read_lock();

	nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
		goto out_unlock;

	err = INDIRECT_CALL_L4(ops->callbacks.gro_complete, tcp6_gro_complete,
			       udp6_gro_complete, skb, nhoff);

out_unlock:
	rcu_read_unlock();

	return err;
}

static int sit_gro_complete(struct sk_buff *skb, int nhoff)
{
	skb->encapsulation = 1;
	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
	return ipv6_gro_complete(skb, nhoff);
}

static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff)
{
	skb->encapsulation = 1;
	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
	return ipv6_gro_complete(skb, nhoff);
}

static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff)
{
	skb->encapsulation = 1;
	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
	return inet_gro_complete(skb, nhoff);
}

static struct packet_offload ipv6_packet_offload __read_mostly = {
	.type = cpu_to_be16(ETH_P_IPV6),
	.callbacks = {
		.gso_segment = ipv6_gso_segment,
		.gro_receive = ipv6_gro_receive,
		.gro_complete = ipv6_gro_complete,
	},
};

static struct sk_buff *sit_gso_segment(struct sk_buff *skb,
				       netdev_features_t features)
{
	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
		return ERR_PTR(-EINVAL);

	return ipv6_gso_segment(skb, features);
}

static struct sk_buff *ip4ip6_gso_segment(struct sk_buff *skb,
					  netdev_features_t features)
{
	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
		return ERR_PTR(-EINVAL);

	return inet_gso_segment(skb, features);
}

static struct sk_buff *ip6ip6_gso_segment(struct sk_buff *skb,
					  netdev_features_t features)
{
	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
		return ERR_PTR(-EINVAL);

	return ipv6_gso_segment(skb, features);
}

static const struct net_offload sit_offload = {
	.callbacks = {
		.gso_segment	= sit_gso_segment,
		.gro_receive    = sit_ip6ip6_gro_receive,
		.gro_complete   = sit_gro_complete,
	},
};

static const struct net_offload ip4ip6_offload = {
	.callbacks = {
		.gso_segment	= ip4ip6_gso_segment,
		.gro_receive    = ip4ip6_gro_receive,
		.gro_complete   = ip4ip6_gro_complete,
	},
};

static const struct net_offload ip6ip6_offload = {
	.callbacks = {
		.gso_segment	= ip6ip6_gso_segment,
		.gro_receive    = sit_ip6ip6_gro_receive,
		.gro_complete   = ip6ip6_gro_complete,
	},
};
static int __init ipv6_offload_init(void)
{

	if (tcpv6_offload_init() < 0)
		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
	if (ipv6_exthdrs_offload_init() < 0)
		pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);

	dev_add_offload(&ipv6_packet_offload);

	inet_add_offload(&sit_offload, IPPROTO_IPV6);
	inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);
	inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP);

	return 0;
}

fs_initcall(ipv6_offload_init);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
d1da932e VY	2	/*
	3	* IPV6 GSO/GRO offload support
	4	* Linux INET6 implementation
d1da932e VY	5	*/
	6
	7	#include <linux/kernel.h>
	8	#include <linux/socket.h>
	9	#include <linux/netdevice.h>
	10	#include <linux/skbuff.h>
c6b641a4	11	#include <linux/printk.h>
d1da932e VY	12
	13	#include <net/protocol.h>
	14	#include <net/ipv6.h>
b8921ca8	15	#include <net/inet_common.h>
5521d95e	16	#include <net/tcp.h>
6db69328	17	#include <net/udp.h>
d1da932e VY	18
	19	#include "ip6_offload.h"
	20
028e0a47 PA	21	/* All GRO functions are always builtin, except UDP over ipv6, which lays in
	22	* ipv6 module, as it depends on UDPv6 lookup function, so we need special care
	23	* when ipv6 is built as a module
	24	*/
	25	#if IS_BUILTIN(CONFIG_IPV6)
	26	#define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__)
	27	#else
	28	#define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
	29	#endif
	30
	31	#define indirect_call_gro_receive_l4(f2, f1, cb, head, skb) \
	32	({ \
	33	unlikely(gro_recursion_inc_test(skb)) ? \
	34	NAPI_GRO_CB(skb)->flush \|= 1, NULL : \
	35	INDIRECT_CALL_L4(cb, f2, f1, head, skb); \
	36	})
	37
d1da932e VY	38	static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
	39	{
	40	const struct net_offload *ops = NULL;
	41
	42	for (;;) {
	43	struct ipv6_opt_hdr *opth;
	44	int len;
	45
	46	if (proto != NEXTHDR_HOP) {
	47	ops = rcu_dereference(inet6_offloads[proto]);
	48
	49	if (unlikely(!ops))
	50	break;
	51
	52	if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
	53	break;
	54	}
	55
	56	if (unlikely(!pskb_may_pull(skb, 8)))
	57	break;
	58
	59	opth = (void *)skb->data;
	60	len = ipv6_optlen(opth);
	61
	62	if (unlikely(!pskb_may_pull(skb, len)))
	63	break;
	64
fc6fb41c	65	opth = (void *)skb->data;
d1da932e VY	66	proto = opth->nexthdr;
	67	__skb_pull(skb, len);
	68	}
	69
	70	return proto;
	71	}
	72
d1da932e VY	73	static struct sk_buff ipv6_gso_segment(struct sk_buff skb,
	74	netdev_features_t features)
	75	{
	76	struct sk_buff *segs = ERR_PTR(-EINVAL);
	77	struct ipv6hdr *ipv6h;
	78	const struct net_offload *ops;
	79	int proto;
	80	struct frag_hdr *fptr;
802ab55a	81	unsigned int payload_len;
d1da932e VY	82	u8 *prevhdr;
d1da932e VY	83	int offset = 0;
91a48a2e	84	bool encap, udpfrag;
d3e5e006	85	int nhoff;
07b26c94	86	bool gso_partial;
d1da932e	87
d3e5e006 ED	88	skb_reset_network_header(skb);
d3e5e006 ED	89	nhoff = skb_network_header(skb) - skb_mac_header(skb);
d1da932e VY	90	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
	91	goto out;
	92
91a48a2e HFS	93	encap = SKB_GSO_CB(skb)->encap_level > 0;
91a48a2e HFS	94	if (encap)
1e16aa3d	95	features &= skb->dev->hw_enc_features;
d3e5e006 ED	96	SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
d3e5e006 ED	97
d1da932e VY	98	ipv6h = ipv6_hdr(skb);
	99	__skb_pull(skb, sizeof(*ipv6h));
	100	segs = ERR_PTR(-EPROTONOSUPPORT);
	101
	102	proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
b917eb15	103
91a48a2e	104	if (skb->encapsulation &&
7e13318d	105	skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 \| SKB_GSO_IPXIP6))
ee80d1eb WB	106	udpfrag = proto == IPPROTO_UDP && encap &&
ee80d1eb WB	107	(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
91a48a2e	108	else
ee80d1eb WB	109	udpfrag = proto == IPPROTO_UDP && !skb->encapsulation &&
ee80d1eb WB	110	(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
91a48a2e	111
d1da932e	112	ops = rcu_dereference(inet6_offloads[proto]);
f191a1d1	113	if (likely(ops && ops->callbacks.gso_segment)) {
d1da932e	114	skb_reset_transport_header(skb);
f191a1d1	115	segs = ops->callbacks.gso_segment(skb, features);
d1da932e	116	}
d1da932e	117
6b6ebb6b	118	if (IS_ERR_OR_NULL(segs))
d1da932e VY	119	goto out;
d1da932e VY	120
07b26c94 SK	121	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
07b26c94 SK	122
d1da932e	123	for (skb = segs; skb; skb = skb->next) {
d3e5e006	124	ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
3d0241d5	125	if (gso_partial && skb_is_gso(skb))
802ab55a AD	126	payload_len = skb_shinfo(skb)->gso_size +
	127	SKB_GSO_CB(skb)->data_offset +
	128	skb->head - (unsigned char *)(ipv6h + 1);
	129	else
	130	payload_len = skb->len - nhoff - sizeof(*ipv6h);
	131	ipv6h->payload_len = htons(payload_len);
d3e5e006	132	skb->network_header = (u8 *)ipv6h - skb->head;
c56cae23	133	skb_reset_mac_len(skb);
d3e5e006	134
91a48a2e	135	if (udpfrag) {
7dd7eb95	136	int err = ip6_find_1stfragopt(skb, &prevhdr);
e3e86b51 DM	137	if (err < 0) {
e3e86b51 DM	138	kfree_skb_list(segs);
7dd7eb95	139	return ERR_PTR(err);
e3e86b51	140	}
7dd7eb95	141	fptr = (struct frag_hdr )((u8 )ipv6h + err);
d1da932e	142	fptr->frag_off = htons(offset);
53b24b8f	143	if (skb->next)
d1da932e VY	144	fptr->frag_off \|= htons(IP6_MF);
	145	offset += (ntohs(ipv6h->payload_len) -
	146	sizeof(struct frag_hdr));
	147	}
91a48a2e HFS	148	if (encap)
91a48a2e HFS	149	skb_reset_inner_headers(skb);
d1da932e VY	150	}
	151
	152	out:
	153	return segs;
	154	}
	155
299603e8 JC	156	/* Return the total length of all the extension hdrs, following the same
	157	* logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.
	158	*/
	159	static int ipv6_exthdrs_len(struct ipv6hdr *iph,
	160	const struct net_offload **opps)
	161	{
810c23a3 JC	162	struct ipv6_opt_hdr opth = (void )iph;
810c23a3 JC	163	int len = 0, proto, optlen = sizeof(*iph);
299603e8 JC	164
	165	proto = iph->nexthdr;
	166	for (;;) {
	167	if (proto != NEXTHDR_HOP) {
	168	*opps = rcu_dereference(inet6_offloads[proto]);
	169	if (unlikely(!(*opps)))
	170	break;
	171	if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
	172	break;
	173	}
810c23a3 JC	174	opth = (void *)opth + optlen;
810c23a3 JC	175	optlen = ipv6_optlen(opth);
299603e8 JC	176	len += optlen;
	177	proto = opth->nexthdr;
	178	}
	179	return len;
	180	}
	181
aaa5d90b PA	182	INDIRECT_CALLABLE_SCOPE struct sk_buff ipv6_gro_receive(struct list_head head,
aaa5d90b PA	183	struct sk_buff *skb)
d1da932e VY	184	{
d1da932e VY	185	const struct net_offload *ops;
d4546c25	186	struct sk_buff *pp = NULL;
d1da932e VY	187	struct sk_buff *p;
	188	struct ipv6hdr *iph;
	189	unsigned int nlen;
	190	unsigned int hlen;
	191	unsigned int off;
bf5a755f	192	u16 flush = 1;
d1da932e	193	int proto;
d1da932e VY	194
	195	off = skb_gro_offset(skb);
	196	hlen = off + sizeof(*iph);
	197	iph = skb_gro_header_fast(skb, off);
	198	if (skb_gro_header_hard(skb, hlen)) {
	199	iph = skb_gro_header_slow(skb, hlen, off);
	200	if (unlikely(!iph))
	201	goto out;
	202	}
	203
299603e8	204	skb_set_network_header(skb, off);
d1da932e VY	205	skb_gro_pull(skb, sizeof(*iph));
	206	skb_set_transport_header(skb, skb_gro_offset(skb));
	207
	208	flush += ntohs(iph->payload_len) != skb_gro_len(skb);
	209
	210	rcu_read_lock();
	211	proto = iph->nexthdr;
	212	ops = rcu_dereference(inet6_offloads[proto]);
f191a1d1	213	if (!ops \|\| !ops->callbacks.gro_receive) {
d1da932e	214	__pskb_pull(skb, skb_gro_offset(skb));
57ea52a8	215	skb_gro_frag0_invalidate(skb);
d1da932e VY	216	proto = ipv6_gso_pull_exthdrs(skb, proto);
	217	skb_gro_pull(skb, -skb_transport_offset(skb));
	218	skb_reset_transport_header(skb);
	219	__skb_push(skb, skb_gro_offset(skb));
	220
	221	ops = rcu_dereference(inet6_offloads[proto]);
f191a1d1	222	if (!ops \|\| !ops->callbacks.gro_receive)
d1da932e VY	223	goto out_unlock;
	224
	225	iph = ipv6_hdr(skb);
	226	}
	227
	228	NAPI_GRO_CB(skb)->proto = proto;
	229
	230	flush--;
	231	nlen = skb_network_header_len(skb);
	232
d4546c25	233	list_for_each_entry(p, head, list) {
d1da932e VY	234	const struct ipv6hdr *iph2;
	235	__be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
	236
	237	if (!NAPI_GRO_CB(p)->same_flow)
	238	continue;
	239
299603e8	240	iph2 = (struct ipv6hdr *)(p->data + off);
67ba4152	241	first_word = (__be32 )iph ^ (__be32 )iph2;
d1da932e	242
299603e8 JC	243	/* All fields must match except length and Traffic Class.
	244	* XXX skbs on the gro_list have all been parsed and pulled
	245	* already so we don't need to compare nlen
	246	* (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))
0b215b97	247	* memcmp() alone below is sufficient, right?
299603e8 JC	248	*/
299603e8 JC	249	if ((first_word & htonl(0xF00FFFFF)) \|\|
0b215b97 ED	250	!ipv6_addr_equal(&iph->saddr, &iph2->saddr) \|\|
	251	!ipv6_addr_equal(&iph->daddr, &iph2->daddr) \|\|
	252	(u16 )&iph->nexthdr != (u16 )&iph2->nexthdr) {
	253	not_same_flow:
d1da932e VY	254	NAPI_GRO_CB(p)->same_flow = 0;
	255	continue;
	256	}
0b215b97 ED	257	if (unlikely(nlen > sizeof(struct ipv6hdr))) {
	258	if (memcmp(iph + 1, iph2 + 1,
	259	nlen - sizeof(struct ipv6hdr)))
	260	goto not_same_flow;
	261	}
d1da932e VY	262	/* flush if Traffic Class fields are different */
	263	NAPI_GRO_CB(p)->flush \|= !!(first_word & htonl(0x0FF00000));
	264	NAPI_GRO_CB(p)->flush \|= flush;
03d56daa	265
1530545e AD	266	/* If the previous IP ID value was based on an atomic
	267	* datagram we can overwrite the value and ignore it.
	268	*/
	269	if (NAPI_GRO_CB(skb)->is_atomic)
	270	NAPI_GRO_CB(p)->flush_id = 0;
d1da932e VY	271	}
d1da932e VY	272
1530545e	273	NAPI_GRO_CB(skb)->is_atomic = true;
d1da932e VY	274	NAPI_GRO_CB(skb)->flush \|= flush;
d1da932e VY	275
4de462ab	276	skb_gro_postpull_rcsum(skb, iph, nlen);
d1da932e	277
028e0a47 PA	278	pp = indirect_call_gro_receive_l4(tcp6_gro_receive, udp6_gro_receive,
028e0a47 PA	279	ops->callbacks.gro_receive, head, skb);
d1da932e	280
d1da932e VY	281	out_unlock:
	282	rcu_read_unlock();
	283
	284	out:
5f114163	285	skb_gro_flush_final(skb, pp, flush);
d1da932e VY	286
	287	return pp;
	288	}
	289
d4546c25 DM	290	static struct sk_buff sit_ip6ip6_gro_receive(struct list_head head,
d4546c25 DM	291	struct sk_buff *skb)
fac8e0f5	292	{
815d22e5 TH	293	/* Common GRO receive for SIT and IP6IP6 */
815d22e5 TH	294
fac8e0f5 JG	295	if (NAPI_GRO_CB(skb)->encap_mark) {
	296	NAPI_GRO_CB(skb)->flush = 1;
	297	return NULL;
	298	}
	299
	300	NAPI_GRO_CB(skb)->encap_mark = 1;
	301
	302	return ipv6_gro_receive(head, skb);
	303	}
	304
d4546c25 DM	305	static struct sk_buff ip4ip6_gro_receive(struct list_head head,
d4546c25 DM	306	struct sk_buff *skb)
b8921ca8 TH	307	{
	308	/* Common GRO receive for SIT and IP6IP6 */
	309
	310	if (NAPI_GRO_CB(skb)->encap_mark) {
	311	NAPI_GRO_CB(skb)->flush = 1;
	312	return NULL;
	313	}
	314
	315	NAPI_GRO_CB(skb)->encap_mark = 1;
	316
	317	return inet_gro_receive(head, skb);
	318	}
	319
aaa5d90b	320	INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
d1da932e VY	321	{
d1da932e VY	322	const struct net_offload *ops;
299603e8	323	struct ipv6hdr iph = (struct ipv6hdr )(skb->data + nhoff);
d1da932e VY	324	int err = -ENOSYS;
d1da932e VY	325
294acf1c PA	326	if (skb->encapsulation) {
294acf1c PA	327	skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
feec0cb3	328	skb_set_inner_network_header(skb, nhoff);
294acf1c	329	}
feec0cb3	330
299603e8	331	iph->payload_len = htons(skb->len - nhoff - sizeof(*iph));
d1da932e VY	332
d1da932e VY	333	rcu_read_lock();
299603e8 JC	334
299603e8 JC	335	nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
f191a1d1	336	if (WARN_ON(!ops \|\| !ops->callbacks.gro_complete))
d1da932e VY	337	goto out_unlock;
d1da932e VY	338
028e0a47 PA	339	err = INDIRECT_CALL_L4(ops->callbacks.gro_complete, tcp6_gro_complete,
028e0a47 PA	340	udp6_gro_complete, skb, nhoff);
d1da932e VY	341
	342	out_unlock:
	343	rcu_read_unlock();
	344
	345	return err;
	346	}
	347
feec0cb3 ED	348	static int sit_gro_complete(struct sk_buff *skb, int nhoff)
	349	{
	350	skb->encapsulation = 1;
7e13318d	351	skb_shinfo(skb)->gso_type \|= SKB_GSO_IPXIP4;
feec0cb3 ED	352	return ipv6_gro_complete(skb, nhoff);
	353	}
	354
815d22e5 TH	355	static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff)
	356	{
	357	skb->encapsulation = 1;
	358	skb_shinfo(skb)->gso_type \|= SKB_GSO_IPXIP6;
	359	return ipv6_gro_complete(skb, nhoff);
	360	}
	361
b8921ca8 TH	362	static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff)
	363	{
	364	skb->encapsulation = 1;
	365	skb_shinfo(skb)->gso_type \|= SKB_GSO_IPXIP6;
	366	return inet_gro_complete(skb, nhoff);
	367	}
	368
d1da932e VY	369	static struct packet_offload ipv6_packet_offload __read_mostly = {
d1da932e VY	370	.type = cpu_to_be16(ETH_P_IPV6),
f191a1d1	371	.callbacks = {
f191a1d1 VY	372	.gso_segment = ipv6_gso_segment,
	373	.gro_receive = ipv6_gro_receive,
	374	.gro_complete = ipv6_gro_complete,
	375	},
d1da932e VY	376	};
d1da932e VY	377
418e897e WB	378	static struct sk_buff sit_gso_segment(struct sk_buff skb,
	379	netdev_features_t features)
	380	{
	381	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
	382	return ERR_PTR(-EINVAL);
	383
	384	return ipv6_gso_segment(skb, features);
	385	}
	386
	387	static struct sk_buff ip4ip6_gso_segment(struct sk_buff skb,
	388	netdev_features_t features)
	389	{
	390	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
	391	return ERR_PTR(-EINVAL);
	392
	393	return inet_gso_segment(skb, features);
	394	}
	395
	396	static struct sk_buff ip6ip6_gso_segment(struct sk_buff skb,
	397	netdev_features_t features)
	398	{
	399	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
	400	return ERR_PTR(-EINVAL);
	401
	402	return ipv6_gso_segment(skb, features);
	403	}
	404
61c1db7f ED	405	static const struct net_offload sit_offload = {
61c1db7f ED	406	.callbacks = {
418e897e	407	.gso_segment = sit_gso_segment,
815d22e5	408	.gro_receive = sit_ip6ip6_gro_receive,
feec0cb3	409	.gro_complete = sit_gro_complete,
61c1db7f ED	410	},
	411	};
	412
b8921ca8 TH	413	static const struct net_offload ip4ip6_offload = {
b8921ca8 TH	414	.callbacks = {
418e897e	415	.gso_segment = ip4ip6_gso_segment,
b8921ca8 TH	416	.gro_receive = ip4ip6_gro_receive,
	417	.gro_complete = ip4ip6_gro_complete,
	418	},
	419	};
	420
815d22e5 TH	421	static const struct net_offload ip6ip6_offload = {
815d22e5 TH	422	.callbacks = {
418e897e	423	.gso_segment = ip6ip6_gso_segment,
815d22e5 TH	424	.gro_receive = sit_ip6ip6_gro_receive,
	425	.gro_complete = ip6ip6_gro_complete,
	426	},
	427	};
c6b641a4	428	static int __init ipv6_offload_init(void)
d1da932e	429	{
c6b641a4 VY	430
	431	if (tcpv6_offload_init() < 0)
	432	pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
c6b641a4 VY	433	if (ipv6_exthdrs_offload_init() < 0)
	434	pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
	435
d1da932e	436	dev_add_offload(&ipv6_packet_offload);
61c1db7f ED	437
61c1db7f ED	438	inet_add_offload(&sit_offload, IPPROTO_IPV6);
815d22e5	439	inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);
b8921ca8	440	inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP);
61c1db7f	441
c6b641a4	442	return 0;
d1da932e VY	443	}
d1da932e VY	444
c6b641a4	445	fs_initcall(ipv6_offload_init);