[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv6 / ip6_offload.c

/*
 *	IPV6 GSO/GRO offload support
 *	Linux INET6 implementation
 *
 *	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/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 "ip6_offload.h"

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;

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

	return proto;
}

static int ipv6_gso_send_check(struct sk_buff *skb)
{
	const struct ipv6hdr *ipv6h;
	const struct net_offload *ops;
	int err = -EINVAL;

	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
		goto out;

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

	rcu_read_lock();
	ops = rcu_dereference(inet6_offloads[
		ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr)]);

	if (likely(ops && ops->callbacks.gso_send_check)) {
		skb_reset_transport_header(skb);
		err = ops->callbacks.gso_send_check(skb);
	}
	rcu_read_unlock();

out:
	return err;
}

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 unfrag_ip6hlen;
	u8 *prevhdr;
	int offset = 0;

	if (!(features & NETIF_F_V6_CSUM))
		features &= ~NETIF_F_SG;

	if (unlikely(skb_shinfo(skb)->gso_type &
		     ~(SKB_GSO_UDP |
		       SKB_GSO_DODGY |
		       SKB_GSO_TCP_ECN |
		       SKB_GSO_GRE |
		       SKB_GSO_TCPV6 |
		       0)))
		goto out;

	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
		goto out;

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

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

	if (IS_ERR(segs))
		goto out;

	for (skb = segs; skb; skb = skb->next) {
		ipv6h = ipv6_hdr(skb);
		ipv6h->payload_len = htons(skb->len - skb->mac_len -
					   sizeof(*ipv6h));
		if (proto == IPPROTO_UDP) {
			unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
			fptr = (struct frag_hdr *)(skb_network_header(skb) +
				unfrag_ip6hlen);
			fptr->frag_off = htons(offset);
			if (skb->next != NULL)
				fptr->frag_off |= htons(IP6_MF);
			offset += (ntohs(ipv6h->payload_len) -
				   sizeof(struct frag_hdr));
		}
	}

out:
	return segs;
}

static struct sk_buff **ipv6_gro_receive(struct sk_buff **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;
	int flush = 1;
	int proto;
	__wsum csum;

	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_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));
		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);

	for (p = *head; p; p = p->next) {
		const struct ipv6hdr *iph2;
		__be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */

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

		iph2 = ipv6_hdr(p);
		first_word = *(__be32 *)iph ^ *(__be32 *)iph2 ;

		/* All fields must match except length and Traffic Class. */
		if (nlen != skb_network_header_len(p) ||
		    (first_word & htonl(0xF00FFFFF)) ||
		    memcmp(&iph->nexthdr, &iph2->nexthdr,
			   nlen - offsetof(struct ipv6hdr, nexthdr))) {
			NAPI_GRO_CB(p)->same_flow = 0;
			continue;
		}
		/* flush if Traffic Class fields are different */
		NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000));
		NAPI_GRO_CB(p)->flush |= flush;
	}

	NAPI_GRO_CB(skb)->flush |= flush;

	csum = skb->csum;
	skb_postpull_rcsum(skb, iph, skb_network_header_len(skb));

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

	skb->csum = csum;

out_unlock:
	rcu_read_unlock();

out:
	NAPI_GRO_CB(skb)->flush |= flush;

	return pp;
}

static int ipv6_gro_complete(struct sk_buff *skb)
{
	const struct net_offload *ops;
	struct ipv6hdr *iph = ipv6_hdr(skb);
	int err = -ENOSYS;

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

	rcu_read_lock();
	ops = rcu_dereference(inet6_offloads[NAPI_GRO_CB(skb)->proto]);
	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
		goto out_unlock;

	err = ops->callbacks.gro_complete(skb);

out_unlock:
	rcu_read_unlock();

	return err;
}

static struct packet_offload ipv6_packet_offload __read_mostly = {
	.type = cpu_to_be16(ETH_P_IPV6),
	.callbacks = {
		.gso_send_check = ipv6_gso_send_check,
		.gso_segment = ipv6_gso_segment,
		.gro_receive = ipv6_gro_receive,
		.gro_complete = ipv6_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 (udp_offload_init() < 0)
		pr_crit("%s: Cannot add UDP 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);
	return 0;
}

fs_initcall(ipv6_offload_init);
Commit	Line	Data
d1da932e VY	1	/*
	2	* IPV6 GSO/GRO offload support
	3	* Linux INET6 implementation
	4	*
	5	* This program is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU General Public License
	7	* as published by the Free Software Foundation; either version
	8	* 2 of the License, or (at your option) any later version.
	9	*/
	10
	11	#include <linux/kernel.h>
	12	#include <linux/socket.h>
	13	#include <linux/netdevice.h>
	14	#include <linux/skbuff.h>
c6b641a4	15	#include <linux/printk.h>
d1da932e VY	16
	17	#include <net/protocol.h>
	18	#include <net/ipv6.h>
	19
	20	#include "ip6_offload.h"
	21
	22	static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
	23	{
	24	const struct net_offload *ops = NULL;
	25
	26	for (;;) {
	27	struct ipv6_opt_hdr *opth;
	28	int len;
	29
	30	if (proto != NEXTHDR_HOP) {
	31	ops = rcu_dereference(inet6_offloads[proto]);
	32
	33	if (unlikely(!ops))
	34	break;
	35
	36	if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
	37	break;
	38	}
	39
	40	if (unlikely(!pskb_may_pull(skb, 8)))
	41	break;
	42
	43	opth = (void *)skb->data;
	44	len = ipv6_optlen(opth);
	45
	46	if (unlikely(!pskb_may_pull(skb, len)))
	47	break;
	48
	49	proto = opth->nexthdr;
	50	__skb_pull(skb, len);
	51	}
	52
	53	return proto;
	54	}
	55
	56	static int ipv6_gso_send_check(struct sk_buff *skb)
	57	{
	58	const struct ipv6hdr *ipv6h;
	59	const struct net_offload *ops;
	60	int err = -EINVAL;
	61
	62	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
	63	goto out;
	64
	65	ipv6h = ipv6_hdr(skb);
	66	__skb_pull(skb, sizeof(*ipv6h));
	67	err = -EPROTONOSUPPORT;
	68
	69	rcu_read_lock();
	70	ops = rcu_dereference(inet6_offloads[
	71	ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr)]);
	72
f191a1d1	73	if (likely(ops && ops->callbacks.gso_send_check)) {
d1da932e	74	skb_reset_transport_header(skb);
f191a1d1	75	err = ops->callbacks.gso_send_check(skb);
d1da932e VY	76	}
	77	rcu_read_unlock();
	78
	79	out:
	80	return err;
	81	}
	82
	83	static struct sk_buff ipv6_gso_segment(struct sk_buff skb,
	84	netdev_features_t features)
	85	{
	86	struct sk_buff *segs = ERR_PTR(-EINVAL);
	87	struct ipv6hdr *ipv6h;
	88	const struct net_offload *ops;
	89	int proto;
	90	struct frag_hdr *fptr;
	91	unsigned int unfrag_ip6hlen;
	92	u8 *prevhdr;
	93	int offset = 0;
	94
	95	if (!(features & NETIF_F_V6_CSUM))
	96	features &= ~NETIF_F_SG;
	97
	98	if (unlikely(skb_shinfo(skb)->gso_type &
	99	~(SKB_GSO_UDP \|
	100	SKB_GSO_DODGY \|
	101	SKB_GSO_TCP_ECN \|
68c33163	102	SKB_GSO_GRE \|
d1da932e VY	103	SKB_GSO_TCPV6 \|
	104	0)))
	105	goto out;
	106
	107	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
	108	goto out;
	109
	110	ipv6h = ipv6_hdr(skb);
	111	__skb_pull(skb, sizeof(*ipv6h));
	112	segs = ERR_PTR(-EPROTONOSUPPORT);
	113
	114	proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
	115	rcu_read_lock();
	116	ops = rcu_dereference(inet6_offloads[proto]);
f191a1d1	117	if (likely(ops && ops->callbacks.gso_segment)) {
d1da932e	118	skb_reset_transport_header(skb);
f191a1d1	119	segs = ops->callbacks.gso_segment(skb, features);
d1da932e VY	120	}
	121	rcu_read_unlock();
	122
	123	if (IS_ERR(segs))
	124	goto out;
	125
	126	for (skb = segs; skb; skb = skb->next) {
	127	ipv6h = ipv6_hdr(skb);
	128	ipv6h->payload_len = htons(skb->len - skb->mac_len -
	129	sizeof(*ipv6h));
	130	if (proto == IPPROTO_UDP) {
	131	unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
	132	fptr = (struct frag_hdr *)(skb_network_header(skb) +
	133	unfrag_ip6hlen);
	134	fptr->frag_off = htons(offset);
	135	if (skb->next != NULL)
	136	fptr->frag_off \|= htons(IP6_MF);
	137	offset += (ntohs(ipv6h->payload_len) -
	138	sizeof(struct frag_hdr));
	139	}
	140	}
	141
	142	out:
	143	return segs;
	144	}
	145
	146	static struct sk_buff ipv6_gro_receive(struct sk_buff head,
	147	struct sk_buff *skb)
	148	{
	149	const struct net_offload *ops;
	150	struct sk_buff **pp = NULL;
	151	struct sk_buff *p;
	152	struct ipv6hdr *iph;
	153	unsigned int nlen;
	154	unsigned int hlen;
	155	unsigned int off;
	156	int flush = 1;
	157	int proto;
	158	__wsum csum;
	159
	160	off = skb_gro_offset(skb);
	161	hlen = off + sizeof(*iph);
	162	iph = skb_gro_header_fast(skb, off);
	163	if (skb_gro_header_hard(skb, hlen)) {
	164	iph = skb_gro_header_slow(skb, hlen, off);
	165	if (unlikely(!iph))
	166	goto out;
	167	}
	168
	169	skb_gro_pull(skb, sizeof(*iph));
	170	skb_set_transport_header(skb, skb_gro_offset(skb));
	171
	172	flush += ntohs(iph->payload_len) != skb_gro_len(skb);
	173
	174	rcu_read_lock();
	175	proto = iph->nexthdr;
	176	ops = rcu_dereference(inet6_offloads[proto]);
f191a1d1	177	if (!ops \|\| !ops->callbacks.gro_receive) {
d1da932e VY	178	__pskb_pull(skb, skb_gro_offset(skb));
	179	proto = ipv6_gso_pull_exthdrs(skb, proto);
	180	skb_gro_pull(skb, -skb_transport_offset(skb));
	181	skb_reset_transport_header(skb);
	182	__skb_push(skb, skb_gro_offset(skb));
	183
	184	ops = rcu_dereference(inet6_offloads[proto]);
f191a1d1	185	if (!ops \|\| !ops->callbacks.gro_receive)
d1da932e VY	186	goto out_unlock;
	187
	188	iph = ipv6_hdr(skb);
	189	}
	190
	191	NAPI_GRO_CB(skb)->proto = proto;
	192
	193	flush--;
	194	nlen = skb_network_header_len(skb);
	195
	196	for (p = *head; p; p = p->next) {
	197	const struct ipv6hdr *iph2;
	198	__be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
	199
	200	if (!NAPI_GRO_CB(p)->same_flow)
	201	continue;
	202
	203	iph2 = ipv6_hdr(p);
	204	first_word = (__be32 )iph ^ (__be32 )iph2 ;
	205
	206	/* All fields must match except length and Traffic Class. */
	207	if (nlen != skb_network_header_len(p) \|\|
	208	(first_word & htonl(0xF00FFFFF)) \|\|
	209	memcmp(&iph->nexthdr, &iph2->nexthdr,
	210	nlen - offsetof(struct ipv6hdr, nexthdr))) {
	211	NAPI_GRO_CB(p)->same_flow = 0;
	212	continue;
	213	}
	214	/* flush if Traffic Class fields are different */
	215	NAPI_GRO_CB(p)->flush \|= !!(first_word & htonl(0x0FF00000));
	216	NAPI_GRO_CB(p)->flush \|= flush;
	217	}
	218
	219	NAPI_GRO_CB(skb)->flush \|= flush;
	220
	221	csum = skb->csum;
	222	skb_postpull_rcsum(skb, iph, skb_network_header_len(skb));
	223
f191a1d1	224	pp = ops->callbacks.gro_receive(head, skb);
d1da932e VY	225
	226	skb->csum = csum;
	227
	228	out_unlock:
	229	rcu_read_unlock();
	230
	231	out:
	232	NAPI_GRO_CB(skb)->flush \|= flush;
	233
	234	return pp;
	235	}
	236
	237	static int ipv6_gro_complete(struct sk_buff *skb)
	238	{
	239	const struct net_offload *ops;
	240	struct ipv6hdr *iph = ipv6_hdr(skb);
	241	int err = -ENOSYS;
	242
	243	iph->payload_len = htons(skb->len - skb_network_offset(skb) -
	244	sizeof(*iph));
	245
	246	rcu_read_lock();
	247	ops = rcu_dereference(inet6_offloads[NAPI_GRO_CB(skb)->proto]);
f191a1d1	248	if (WARN_ON(!ops \|\| !ops->callbacks.gro_complete))
d1da932e VY	249	goto out_unlock;
d1da932e VY	250
f191a1d1	251	err = ops->callbacks.gro_complete(skb);
d1da932e VY	252
	253	out_unlock:
	254	rcu_read_unlock();
	255
	256	return err;
	257	}
	258
	259	static struct packet_offload ipv6_packet_offload __read_mostly = {
	260	.type = cpu_to_be16(ETH_P_IPV6),
f191a1d1 VY	261	.callbacks = {
	262	.gso_send_check = ipv6_gso_send_check,
	263	.gso_segment = ipv6_gso_segment,
	264	.gro_receive = ipv6_gro_receive,
	265	.gro_complete = ipv6_gro_complete,
	266	},
d1da932e VY	267	};
d1da932e VY	268
c6b641a4	269	static int __init ipv6_offload_init(void)
d1da932e	270	{
c6b641a4 VY	271
	272	if (tcpv6_offload_init() < 0)
	273	pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
	274	if (udp_offload_init() < 0)
	275	pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
	276	if (ipv6_exthdrs_offload_init() < 0)
	277	pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
	278
d1da932e	279	dev_add_offload(&ipv6_packet_offload);
c6b641a4	280	return 0;
d1da932e VY	281	}
d1da932e VY	282
c6b641a4	283	fs_initcall(ipv6_offload_init);