[mirror_ubuntu-artful-kernel.git] / net / ipv4 / udp_offload.c

/*
 *	IPV4 GSO/GRO offload support
 *	Linux INET 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.
 *
 *	UDPv4 GSO support
 */

#include <linux/skbuff.h>
#include <net/udp.h>
#include <net/protocol.h>

static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
	netdev_features_t features,
	struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb,
					     netdev_features_t features),
	__be16 new_protocol, bool is_ipv6)
{
	int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
	bool remcsum, need_csum, offload_csum, ufo;
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	struct udphdr *uh = udp_hdr(skb);
	u16 mac_offset = skb->mac_header;
	__be16 protocol = skb->protocol;
	u16 mac_len = skb->mac_len;
	int udp_offset, outer_hlen;
	__wsum partial;

	if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
		goto out;

	/* Adjust partial header checksum to negate old length.
	 * We cannot rely on the value contained in uh->len as it is
	 * possible that the actual value exceeds the boundaries of the
	 * 16 bit length field due to the header being added outside of an
	 * IP or IPv6 frame that was already limited to 64K - 1.
	 */
	partial = csum_sub(csum_unfold(uh->check),
			   (__force __wsum)htonl(skb->len));

	/* setup inner skb. */
	skb->encapsulation = 0;
	SKB_GSO_CB(skb)->encap_level = 0;
	__skb_pull(skb, tnl_hlen);
	skb_reset_mac_header(skb);
	skb_set_network_header(skb, skb_inner_network_offset(skb));
	skb->mac_len = skb_inner_network_offset(skb);
	skb->protocol = new_protocol;

	need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
	skb->encap_hdr_csum = need_csum;

	remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
	skb->remcsum_offload = remcsum;

	ufo = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);

	/* Try to offload checksum if possible */
	offload_csum = !!(need_csum &&
			  (skb->dev->features &
			   (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) :
				      (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM))));

	features &= skb->dev->hw_enc_features;

	/* The only checksum offload we care about from here on out is the
	 * outer one so strip the existing checksum feature flags and
	 * instead set the flag based on our outer checksum offload value.
	 */
	if (remcsum || ufo) {
		features &= ~NETIF_F_CSUM_MASK;
		if (!need_csum || offload_csum)
			features |= NETIF_F_HW_CSUM;
	}

	/* segment inner packet. */
	segs = gso_inner_segment(skb, features);
	if (IS_ERR_OR_NULL(segs)) {
		skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
				     mac_len);
		goto out;
	}

	outer_hlen = skb_tnl_header_len(skb);
	udp_offset = outer_hlen - tnl_hlen;
	skb = segs;
	do {
		__be16 len;

		if (remcsum)
			skb->ip_summed = CHECKSUM_NONE;

		/* Set up inner headers if we are offloading inner checksum */
		if (skb->ip_summed == CHECKSUM_PARTIAL) {
			skb_reset_inner_headers(skb);
			skb->encapsulation = 1;
		}

		skb->mac_len = mac_len;
		skb->protocol = protocol;

		__skb_push(skb, outer_hlen);
		skb_reset_mac_header(skb);
		skb_set_network_header(skb, mac_len);
		skb_set_transport_header(skb, udp_offset);
		len = htons(skb->len - udp_offset);
		uh = udp_hdr(skb);
		uh->len = len;

		if (!need_csum)
			continue;

		uh->check = ~csum_fold(csum_add(partial, (__force __wsum)len));

		if (skb->encapsulation || !offload_csum) {
			uh->check = gso_make_checksum(skb, ~uh->check);
			if (uh->check == 0)
				uh->check = CSUM_MANGLED_0;
		} else {
			skb->ip_summed = CHECKSUM_PARTIAL;
			skb->csum_start = skb_transport_header(skb) - skb->head;
			skb->csum_offset = offsetof(struct udphdr, check);
		}
	} while ((skb = skb->next));
out:
	return segs;
}

struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
				       netdev_features_t features,
				       bool is_ipv6)
{
	__be16 protocol = skb->protocol;
	const struct net_offload **offloads;
	const struct net_offload *ops;
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb,
					     netdev_features_t features);

	rcu_read_lock();

	switch (skb->inner_protocol_type) {
	case ENCAP_TYPE_ETHER:
		protocol = skb->inner_protocol;
		gso_inner_segment = skb_mac_gso_segment;
		break;
	case ENCAP_TYPE_IPPROTO:
		offloads = is_ipv6 ? inet6_offloads : inet_offloads;
		ops = rcu_dereference(offloads[skb->inner_ipproto]);
		if (!ops || !ops->callbacks.gso_segment)
			goto out_unlock;
		gso_inner_segment = ops->callbacks.gso_segment;
		break;
	default:
		goto out_unlock;
	}

	segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment,
					protocol, is_ipv6);

out_unlock:
	rcu_read_unlock();

	return segs;
}
EXPORT_SYMBOL(skb_udp_tunnel_segment);

static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
					 netdev_features_t features)
{
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	unsigned int mss;
	__wsum csum;
	struct udphdr *uh;
	struct iphdr *iph;

	if (skb->encapsulation &&
	    (skb_shinfo(skb)->gso_type &
	     (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) {
		segs = skb_udp_tunnel_segment(skb, features, false);
		goto out;
	}

	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
		goto out;

	mss = skb_shinfo(skb)->gso_size;
	if (unlikely(skb->len <= mss))
		goto out;

	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
		/* Packet is from an untrusted source, reset gso_segs. */
		int type = skb_shinfo(skb)->gso_type;

		if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY |
				      SKB_GSO_UDP_TUNNEL |
				      SKB_GSO_UDP_TUNNEL_CSUM |
				      SKB_GSO_TUNNEL_REMCSUM |
				      SKB_GSO_IPIP |
				      SKB_GSO_GRE | SKB_GSO_GRE_CSUM) ||
			     !(type & (SKB_GSO_UDP))))
			goto out;

		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);

		segs = NULL;
		goto out;
	}

	/* Do software UFO. Complete and fill in the UDP checksum as
	 * HW cannot do checksum of UDP packets sent as multiple
	 * IP fragments.
	 */

	uh = udp_hdr(skb);
	iph = ip_hdr(skb);

	uh->check = 0;
	csum = skb_checksum(skb, 0, skb->len, 0);
	uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum);
	if (uh->check == 0)
		uh->check = CSUM_MANGLED_0;

	skb->ip_summed = CHECKSUM_NONE;

	/* If there is no outer header we can fake a checksum offload
	 * due to the fact that we have already done the checksum in
	 * software prior to segmenting the frame.
	 */
	if (!skb->encap_hdr_csum)
		features |= NETIF_F_HW_CSUM;

	/* Fragment the skb. IP headers of the fragments are updated in
	 * inet_gso_segment()
	 */
	segs = skb_segment(skb, features);
out:
	return segs;
}

struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb,
				 struct udphdr *uh, udp_lookup_t lookup)
{
	struct sk_buff *p, **pp = NULL;
	struct udphdr *uh2;
	unsigned int off = skb_gro_offset(skb);
	int flush = 1;
	struct sock *sk;

	if (NAPI_GRO_CB(skb)->encap_mark ||
	    (skb->ip_summed != CHECKSUM_PARTIAL &&
	     NAPI_GRO_CB(skb)->csum_cnt == 0 &&
	     !NAPI_GRO_CB(skb)->csum_valid))
		goto out;

	/* mark that this skb passed once through the tunnel gro layer */
	NAPI_GRO_CB(skb)->encap_mark = 1;

	rcu_read_lock();
	sk = (*lookup)(skb, uh->source, uh->dest);

	if (sk && udp_sk(sk)->gro_receive)
		goto unflush;
	goto out_unlock;

unflush:
	flush = 0;

	for (p = *head; p; p = p->next) {
		if (!NAPI_GRO_CB(p)->same_flow)
			continue;

		uh2 = (struct udphdr   *)(p->data + off);

		/* Match ports and either checksums are either both zero
		 * or nonzero.
		 */
		if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) ||
		    (!uh->check ^ !uh2->check)) {
			NAPI_GRO_CB(p)->same_flow = 0;
			continue;
		}
	}

	skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
	skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr));
	pp = udp_sk(sk)->gro_receive(sk, head, skb);

out_unlock:
	rcu_read_unlock();
out:
	NAPI_GRO_CB(skb)->flush |= flush;
	return pp;
}
EXPORT_SYMBOL(udp_gro_receive);

static struct sk_buff **udp4_gro_receive(struct sk_buff **head,
					 struct sk_buff *skb)
{
	struct udphdr *uh = udp_gro_udphdr(skb);

	if (unlikely(!uh))
		goto flush;

	/* Don't bother verifying checksum if we're going to flush anyway. */
	if (NAPI_GRO_CB(skb)->flush)
		goto skip;

	if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
						 inet_gro_compute_pseudo))
		goto flush;
	else if (uh->check)
		skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
					     inet_gro_compute_pseudo);
skip:
	NAPI_GRO_CB(skb)->is_ipv6 = 0;
	return udp_gro_receive(head, skb, uh, udp4_lib_lookup_skb);

flush:
	NAPI_GRO_CB(skb)->flush = 1;
	return NULL;
}

int udp_gro_complete(struct sk_buff *skb, int nhoff,
		     udp_lookup_t lookup)
{
	__be16 newlen = htons(skb->len - nhoff);
	struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
	int err = -ENOSYS;
	struct sock *sk;

	uh->len = newlen;

	rcu_read_lock();
	sk = (*lookup)(skb, uh->source, uh->dest);
	if (sk && udp_sk(sk)->gro_complete)
		err = udp_sk(sk)->gro_complete(sk, skb,
				nhoff + sizeof(struct udphdr));
	rcu_read_unlock();

	if (skb->remcsum_offload)
		skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM;

	skb->encapsulation = 1;
	skb_set_inner_mac_header(skb, nhoff + sizeof(struct udphdr));

	return err;
}
EXPORT_SYMBOL(udp_gro_complete);

static int udp4_gro_complete(struct sk_buff *skb, int nhoff)
{
	const struct iphdr *iph = ip_hdr(skb);
	struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);

	if (uh->check) {
		skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
		uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr,
					  iph->daddr, 0);
	} else {
		skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL;
	}

	return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb);
}

static const struct net_offload udpv4_offload = {
	.callbacks = {
		.gso_segment = udp4_ufo_fragment,
		.gro_receive  =	udp4_gro_receive,
		.gro_complete =	udp4_gro_complete,
	},
};

int __init udpv4_offload_init(void)
{
	return inet_add_offload(&udpv4_offload, IPPROTO_UDP);
}
Commit	Line	Data
da5bab07 DB	1	/*
	2	* IPV4 GSO/GRO offload support
	3	* Linux INET 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	* UDPv4 GSO support
	11	*/
	12
	13	#include <linux/skbuff.h>
	14	#include <net/udp.h>
	15	#include <net/protocol.h>
	16
8bce6d7d TH	17	static struct sk_buff __skb_udp_tunnel_segment(struct sk_buff skb,
	18	netdev_features_t features,
	19	struct sk_buff (gso_inner_segment)(struct sk_buff *skb,
	20	netdev_features_t features),
4bcb877d	21	__be16 new_protocol, bool is_ipv6)
155e010e	22	{
dbef491e	23	int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
22463876	24	bool remcsum, need_csum, offload_csum, ufo;
155e010e	25	struct sk_buff *segs = ERR_PTR(-EINVAL);
dbef491e	26	struct udphdr *uh = udp_hdr(skb);
155e010e	27	u16 mac_offset = skb->mac_header;
155e010e	28	__be16 protocol = skb->protocol;
dbef491e	29	u16 mac_len = skb->mac_len;
155e010e	30	int udp_offset, outer_hlen;
08334824	31	__wsum partial;
155e010e TH	32
	33	if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
	34	goto out;
	35
08334824 AD	36	/* Adjust partial header checksum to negate old length.
	37	* We cannot rely on the value contained in uh->len as it is
	38	* possible that the actual value exceeds the boundaries of the
	39	* 16 bit length field due to the header being added outside of an
	40	* IP or IPv6 frame that was already limited to 64K - 1.
	41	*/
	42	partial = csum_sub(csum_unfold(uh->check),
	43	(__force __wsum)htonl(skb->len));
dbef491e AD	44
dbef491e AD	45	/* setup inner skb. */
155e010e	46	skb->encapsulation = 0;
5197f349	47	SKB_GSO_CB(skb)->encap_level = 0;
155e010e TH	48	__skb_pull(skb, tnl_hlen);
	49	skb_reset_mac_header(skb);
	50	skb_set_network_header(skb, skb_inner_network_offset(skb));
	51	skb->mac_len = skb_inner_network_offset(skb);
8bce6d7d	52	skb->protocol = new_protocol;
fdaefd62 AD	53
fdaefd62 AD	54	need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
4bcb877d	55	skb->encap_hdr_csum = need_csum;
fdaefd62 AD	56
fdaefd62 AD	57	remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
e585f236	58	skb->remcsum_offload = remcsum;
155e010e	59
22463876 AD	60	ufo = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
22463876 AD	61
4bcb877d TH	62	/* Try to offload checksum if possible */
4bcb877d TH	63	offload_csum = !!(need_csum &&
fdaefd62 AD	64	(skb->dev->features &
	65	(is_ipv6 ? (NETIF_F_HW_CSUM \| NETIF_F_IPV6_CSUM) :
	66	(NETIF_F_HW_CSUM \| NETIF_F_IP_CSUM))));
155e010e	67
bef3c6c9 AD	68	features &= skb->dev->hw_enc_features;
bef3c6c9 AD	69
7fbeffed AD	70	/* The only checksum offload we care about from here on out is the
	71	* outer one so strip the existing checksum feature flags and
	72	* instead set the flag based on our outer checksum offload value.
	73	*/
22463876	74	if (remcsum \|\| ufo) {
7fbeffed	75	features &= ~NETIF_F_CSUM_MASK;
22463876	76	if (!need_csum \|\| offload_csum)
7fbeffed AD	77	features \|= NETIF_F_HW_CSUM;
	78	}
	79
155e010e	80	/* segment inner packet. */
bef3c6c9	81	segs = gso_inner_segment(skb, features);
27446442	82	if (IS_ERR_OR_NULL(segs)) {
155e010e TH	83	skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
	84	mac_len);
	85	goto out;
	86	}
	87
	88	outer_hlen = skb_tnl_header_len(skb);
	89	udp_offset = outer_hlen - tnl_hlen;
	90	skb = segs;
	91	do {
dbef491e	92	__be16 len;
4bcb877d	93
fdaefd62	94	if (remcsum)
4bcb877d	95	skb->ip_summed = CHECKSUM_NONE;
fdaefd62 AD	96
	97	/* Set up inner headers if we are offloading inner checksum */
	98	if (skb->ip_summed == CHECKSUM_PARTIAL) {
4bcb877d TH	99	skb_reset_inner_headers(skb);
	100	skb->encapsulation = 1;
	101	}
155e010e TH	102
155e010e TH	103	skb->mac_len = mac_len;
4bcb877d	104	skb->protocol = protocol;
155e010e	105
dbef491e	106	__skb_push(skb, outer_hlen);
155e010e TH	107	skb_reset_mac_header(skb);
	108	skb_set_network_header(skb, mac_len);
	109	skb_set_transport_header(skb, udp_offset);
dbef491e	110	len = htons(skb->len - udp_offset);
155e010e	111	uh = udp_hdr(skb);
dbef491e	112	uh->len = len;
155e010e	113
4bcb877d TH	114	if (!need_csum)
	115	continue;
	116
08334824	117	uh->check = ~csum_fold(csum_add(partial, (__force __wsum)len));
155e010e	118
fdaefd62 AD	119	if (skb->encapsulation \|\| !offload_csum) {
fdaefd62 AD	120	uh->check = gso_make_checksum(skb, ~uh->check);
155e010e TH	121	if (uh->check == 0)
155e010e TH	122	uh->check = CSUM_MANGLED_0;
fdaefd62 AD	123	} else {
	124	skb->ip_summed = CHECKSUM_PARTIAL;
	125	skb->csum_start = skb_transport_header(skb) - skb->head;
	126	skb->csum_offset = offsetof(struct udphdr, check);
155e010e	127	}
155e010e TH	128	} while ((skb = skb->next));
	129	out:
	130	return segs;
	131	}
	132
8bce6d7d TH	133	struct sk_buff skb_udp_tunnel_segment(struct sk_buff skb,
	134	netdev_features_t features,
	135	bool is_ipv6)
	136	{
	137	__be16 protocol = skb->protocol;
	138	const struct net_offload **offloads;
	139	const struct net_offload *ops;
	140	struct sk_buff *segs = ERR_PTR(-EINVAL);
	141	struct sk_buff (gso_inner_segment)(struct sk_buff *skb,
	142	netdev_features_t features);
	143
	144	rcu_read_lock();
	145
	146	switch (skb->inner_protocol_type) {
	147	case ENCAP_TYPE_ETHER:
	148	protocol = skb->inner_protocol;
	149	gso_inner_segment = skb_mac_gso_segment;
	150	break;
	151	case ENCAP_TYPE_IPPROTO:
	152	offloads = is_ipv6 ? inet6_offloads : inet_offloads;
	153	ops = rcu_dereference(offloads[skb->inner_ipproto]);
	154	if (!ops \|\| !ops->callbacks.gso_segment)
	155	goto out_unlock;
	156	gso_inner_segment = ops->callbacks.gso_segment;
	157	break;
	158	default:
	159	goto out_unlock;
	160	}
	161
	162	segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment,
4bcb877d	163	protocol, is_ipv6);
8bce6d7d TH	164
	165	out_unlock:
	166	rcu_read_unlock();
	167
	168	return segs;
	169	}
a6024562	170	EXPORT_SYMBOL(skb_udp_tunnel_segment);
8bce6d7d	171
da5bab07 DB	172	static struct sk_buff udp4_ufo_fragment(struct sk_buff skb,
	173	netdev_features_t features)
	174	{
	175	struct sk_buff *segs = ERR_PTR(-EINVAL);
	176	unsigned int mss;
7a7ffbab	177	__wsum csum;
f71470b3 TH	178	struct udphdr *uh;
f71470b3 TH	179	struct iphdr *iph;
7a7ffbab WCC	180
7a7ffbab WCC	181	if (skb->encapsulation &&
0f4f4ffa TH	182	(skb_shinfo(skb)->gso_type &
0f4f4ffa TH	183	(SKB_GSO_UDP_TUNNEL\|SKB_GSO_UDP_TUNNEL_CSUM))) {
8bce6d7d	184	segs = skb_udp_tunnel_segment(skb, features, false);
7a7ffbab WCC	185	goto out;
7a7ffbab WCC	186	}
da5bab07	187
f71470b3 TH	188	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
	189	goto out;
	190
da5bab07 DB	191	mss = skb_shinfo(skb)->gso_size;
	192	if (unlikely(skb->len <= mss))
	193	goto out;
	194
	195	if (skb_gso_ok(skb, features \| NETIF_F_GSO_ROBUST)) {
	196	/* Packet is from an untrusted source, reset gso_segs. */
	197	int type = skb_shinfo(skb)->gso_type;
	198
	199	if (unlikely(type & ~(SKB_GSO_UDP \| SKB_GSO_DODGY \|
	200	SKB_GSO_UDP_TUNNEL \|
0f4f4ffa	201	SKB_GSO_UDP_TUNNEL_CSUM \|
e585f236	202	SKB_GSO_TUNNEL_REMCSUM \|
cb32f511	203	SKB_GSO_IPIP \|
59b93b41	204	SKB_GSO_GRE \| SKB_GSO_GRE_CSUM) \|\|
da5bab07 DB	205	!(type & (SKB_GSO_UDP))))
	206	goto out;
	207
	208	skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
	209
	210	segs = NULL;
	211	goto out;
	212	}
	213
7a7ffbab WCC	214	/* Do software UFO. Complete and fill in the UDP checksum as
	215	* HW cannot do checksum of UDP packets sent as multiple
	216	* IP fragments.
	217	*/
f71470b3 TH	218
	219	uh = udp_hdr(skb);
	220	iph = ip_hdr(skb);
	221
	222	uh->check = 0;
	223	csum = skb_checksum(skb, 0, skb->len, 0);
	224	uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum);
	225	if (uh->check == 0)
	226	uh->check = CSUM_MANGLED_0;
	227
7a7ffbab WCC	228	skb->ip_summed = CHECKSUM_NONE;
7a7ffbab WCC	229
22463876 AD	230	/* If there is no outer header we can fake a checksum offload
	231	* due to the fact that we have already done the checksum in
	232	* software prior to segmenting the frame.
	233	*/
	234	if (!skb->encap_hdr_csum)
	235	features \|= NETIF_F_HW_CSUM;
	236
da5bab07 DB	237	/* Fragment the skb. IP headers of the fragments are updated in
	238	* inet_gso_segment()
	239	*/
7a7ffbab	240	segs = skb_segment(skb, features);
da5bab07 DB	241	out:
	242	return segs;
	243	}
	244
57c67ff4	245	struct sk_buff udp_gro_receive(struct sk_buff head, struct sk_buff *skb,
a6024562	246	struct udphdr *uh, udp_lookup_t lookup)
b582ef09	247	{
b582ef09	248	struct sk_buff p, *pp = NULL;
57c67ff4 TH	249	struct udphdr *uh2;
57c67ff4 TH	250	unsigned int off = skb_gro_offset(skb);
b582ef09	251	int flush = 1;
a6024562	252	struct sock *sk;
b582ef09	253
fac8e0f5	254	if (NAPI_GRO_CB(skb)->encap_mark \|\|
662880f4 TH	255	(skb->ip_summed != CHECKSUM_PARTIAL &&
	256	NAPI_GRO_CB(skb)->csum_cnt == 0 &&
	257	!NAPI_GRO_CB(skb)->csum_valid))
b582ef09 OG	258	goto out;
b582ef09 OG	259
fac8e0f5 JG	260	/* mark that this skb passed once through the tunnel gro layer */
fac8e0f5 JG	261	NAPI_GRO_CB(skb)->encap_mark = 1;
b582ef09 OG	262
b582ef09 OG	263	rcu_read_lock();
a6024562 TH	264	sk = (*lookup)(skb, uh->source, uh->dest);
	265
	266	if (sk && udp_sk(sk)->gro_receive)
	267	goto unflush;
b582ef09 OG	268	goto out_unlock;
	269
	270	unflush:
	271	flush = 0;
	272
	273	for (p = *head; p; p = p->next) {
	274	if (!NAPI_GRO_CB(p)->same_flow)
	275	continue;
	276
	277	uh2 = (struct udphdr *)(p->data + off);
57c67ff4 TH	278
	279	/* Match ports and either checksums are either both zero
	280	* or nonzero.
	281	*/
	282	if (((u32 )&uh->source != (u32 )&uh2->source) \|\|
	283	(!uh->check ^ !uh2->check)) {
b582ef09 OG	284	NAPI_GRO_CB(p)->same_flow = 0;
	285	continue;
	286	}
	287	}
	288
	289	skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
6bae1d4c	290	skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr));
a6024562	291	pp = udp_sk(sk)->gro_receive(sk, head, skb);
b582ef09 OG	292
	293	out_unlock:
	294	rcu_read_unlock();
	295	out:
	296	NAPI_GRO_CB(skb)->flush \|= flush;
	297	return pp;
	298	}
a6024562	299	EXPORT_SYMBOL(udp_gro_receive);
b582ef09	300
57c67ff4 TH	301	static struct sk_buff udp4_gro_receive(struct sk_buff head,
	302	struct sk_buff *skb)
	303	{
	304	struct udphdr *uh = udp_gro_udphdr(skb);
	305
2abb7cdc TH	306	if (unlikely(!uh))
2abb7cdc TH	307	goto flush;
57c67ff4	308
2abb7cdc	309	/* Don't bother verifying checksum if we're going to flush anyway. */
2d8f7e2c	310	if (NAPI_GRO_CB(skb)->flush)
2abb7cdc TH	311	goto skip;
	312
	313	if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
	314	inet_gro_compute_pseudo))
	315	goto flush;
	316	else if (uh->check)
	317	skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
	318	inet_gro_compute_pseudo);
	319	skip:
efc98d08	320	NAPI_GRO_CB(skb)->is_ipv6 = 0;
a6024562	321	return udp_gro_receive(head, skb, uh, udp4_lib_lookup_skb);
2abb7cdc TH	322
	323	flush:
	324	NAPI_GRO_CB(skb)->flush = 1;
	325	return NULL;
57c67ff4 TH	326	}
57c67ff4 TH	327
a6024562 TH	328	int udp_gro_complete(struct sk_buff *skb, int nhoff,
a6024562 TH	329	udp_lookup_t lookup)
b582ef09	330	{
b582ef09 OG	331	__be16 newlen = htons(skb->len - nhoff);
	332	struct udphdr uh = (struct udphdr )(skb->data + nhoff);
	333	int err = -ENOSYS;
a6024562	334	struct sock *sk;
b582ef09 OG	335
	336	uh->len = newlen;
	337
	338	rcu_read_lock();
a6024562 TH	339	sk = (*lookup)(skb, uh->source, uh->dest);
	340	if (sk && udp_sk(sk)->gro_complete)
	341	err = udp_sk(sk)->gro_complete(sk, skb,
	342	nhoff + sizeof(struct udphdr));
b582ef09	343	rcu_read_unlock();
6db93ea1 TH	344
	345	if (skb->remcsum_offload)
	346	skb_shinfo(skb)->gso_type \|= SKB_GSO_TUNNEL_REMCSUM;
	347
	348	skb->encapsulation = 1;
	349	skb_set_inner_mac_header(skb, nhoff + sizeof(struct udphdr));
	350
b582ef09 OG	351	return err;
b582ef09 OG	352	}
a6024562	353	EXPORT_SYMBOL(udp_gro_complete);
b582ef09	354
72bb17b3	355	static int udp4_gro_complete(struct sk_buff *skb, int nhoff)
57c67ff4 TH	356	{
	357	const struct iphdr *iph = ip_hdr(skb);
	358	struct udphdr uh = (struct udphdr )(skb->data + nhoff);
	359
6db93ea1 TH	360	if (uh->check) {
6db93ea1 TH	361	skb_shinfo(skb)->gso_type \|= SKB_GSO_UDP_TUNNEL_CSUM;
57c67ff4 TH	362	uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr,
57c67ff4 TH	363	iph->daddr, 0);
6db93ea1 TH	364	} else {
	365	skb_shinfo(skb)->gso_type \|= SKB_GSO_UDP_TUNNEL;
	366	}
57c67ff4	367
a6024562	368	return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb);
57c67ff4 TH	369	}
57c67ff4 TH	370
da5bab07 DB	371	static const struct net_offload udpv4_offload = {
da5bab07 DB	372	.callbacks = {
da5bab07	373	.gso_segment = udp4_ufo_fragment,
57c67ff4 TH	374	.gro_receive = udp4_gro_receive,
57c67ff4 TH	375	.gro_complete = udp4_gro_complete,
da5bab07 DB	376	},
	377	};
	378
	379	int __init udpv4_offload_init(void)
	380	{
	381	return inet_add_offload(&udpv4_offload, IPPROTO_UDP);
	382	}