[linux-2.6-block.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 DEFINE_SPINLOCK(udp_offload_lock);
static struct udp_offload_priv __rcu *udp_offload_base __read_mostly;

#define udp_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&udp_offload_lock))

struct udp_offload_priv {
	struct udp_offload	*offload;
	possible_net_t	net;
	struct rcu_head		rcu;
	struct udp_offload_priv __rcu *next;
};

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;
}

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;
}

int udp_add_offload(struct net *net, struct udp_offload *uo)
{
	struct udp_offload_priv *new_offload = kzalloc(sizeof(*new_offload), GFP_ATOMIC);

	if (!new_offload)
		return -ENOMEM;

	write_pnet(&new_offload->net, net);
	new_offload->offload = uo;

	spin_lock(&udp_offload_lock);
	new_offload->next = udp_offload_base;
	rcu_assign_pointer(udp_offload_base, new_offload);
	spin_unlock(&udp_offload_lock);

	return 0;
}
EXPORT_SYMBOL(udp_add_offload);

static void udp_offload_free_routine(struct rcu_head *head)
{
	struct udp_offload_priv *ou_priv = container_of(head, struct udp_offload_priv, rcu);
	kfree(ou_priv);
}

void udp_del_offload(struct udp_offload *uo)
{
	struct udp_offload_priv __rcu **head = &udp_offload_base;
	struct udp_offload_priv *uo_priv;

	spin_lock(&udp_offload_lock);

	uo_priv = udp_deref_protected(*head);
	for (; uo_priv != NULL;
	     uo_priv = udp_deref_protected(*head)) {
		if (uo_priv->offload == uo) {
			rcu_assign_pointer(*head,
					   udp_deref_protected(uo_priv->next));
			goto unlock;
		}
		head = &uo_priv->next;
	}
	pr_warn("udp_del_offload: didn't find offload for port %d\n", ntohs(uo->port));
unlock:
	spin_unlock(&udp_offload_lock);
	if (uo_priv)
		call_rcu(&uo_priv->rcu, udp_offload_free_routine);
}
EXPORT_SYMBOL(udp_del_offload);

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

	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();
	uo_priv = rcu_dereference(udp_offload_base);
	for (; uo_priv != NULL; uo_priv = rcu_dereference(uo_priv->next)) {
		if (net_eq(read_pnet(&uo_priv->net), dev_net(skb->dev)) &&
		    uo_priv->offload->port == uh->dest &&
		    uo_priv->offload->callbacks.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));
	NAPI_GRO_CB(skb)->proto = uo_priv->offload->ipproto;
	pp = uo_priv->offload->callbacks.gro_receive(head, skb,
						     uo_priv->offload);

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

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);

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

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

	uh->len = newlen;

	/* Set encapsulation before calling into inner gro_complete() functions
	 * to make them set up the inner offsets.
	 */
	skb->encapsulation = 1;

	rcu_read_lock();

	uo_priv = rcu_dereference(udp_offload_base);
	for (; uo_priv != NULL; uo_priv = rcu_dereference(uo_priv->next)) {
		if (net_eq(read_pnet(&uo_priv->net), dev_net(skb->dev)) &&
		    uo_priv->offload->port == uh->dest &&
		    uo_priv->offload->callbacks.gro_complete)
			break;
	}

	if (uo_priv) {
		NAPI_GRO_CB(skb)->proto = uo_priv->offload->ipproto;
		err = uo_priv->offload->callbacks.gro_complete(skb,
				nhoff + sizeof(struct udphdr),
				uo_priv->offload);
	}

	rcu_read_unlock();

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

	return err;
}

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);
}

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
b582ef09	17	static DEFINE_SPINLOCK(udp_offload_lock);
a1d0cd8e	18	static struct udp_offload_priv __rcu *udp_offload_base __read_mostly;
b582ef09	19
a664a4f7 SP	20	#define udp_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&udp_offload_lock))
a664a4f7 SP	21
b582ef09 OG	22	struct udp_offload_priv {
b582ef09 OG	23	struct udp_offload *offload;
787d7ac3	24	possible_net_t net;
b582ef09 OG	25	struct rcu_head rcu;
	26	struct udp_offload_priv __rcu *next;
	27	};
	28
8bce6d7d TH	29	static struct sk_buff __skb_udp_tunnel_segment(struct sk_buff skb,
	30	netdev_features_t features,
	31	struct sk_buff (gso_inner_segment)(struct sk_buff *skb,
	32	netdev_features_t features),
4bcb877d	33	__be16 new_protocol, bool is_ipv6)
155e010e	34	{
dbef491e	35	int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
22463876	36	bool remcsum, need_csum, offload_csum, ufo;
155e010e	37	struct sk_buff *segs = ERR_PTR(-EINVAL);
dbef491e	38	struct udphdr *uh = udp_hdr(skb);
155e010e	39	u16 mac_offset = skb->mac_header;
155e010e	40	__be16 protocol = skb->protocol;
dbef491e	41	u16 mac_len = skb->mac_len;
155e010e	42	int udp_offset, outer_hlen;
08334824	43	__wsum partial;
155e010e TH	44
	45	if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
	46	goto out;
	47
08334824 AD	48	/* Adjust partial header checksum to negate old length.
	49	* We cannot rely on the value contained in uh->len as it is
	50	* possible that the actual value exceeds the boundaries of the
	51	* 16 bit length field due to the header being added outside of an
	52	* IP or IPv6 frame that was already limited to 64K - 1.
	53	*/
	54	partial = csum_sub(csum_unfold(uh->check),
	55	(__force __wsum)htonl(skb->len));
dbef491e AD	56
dbef491e AD	57	/* setup inner skb. */
155e010e	58	skb->encapsulation = 0;
5197f349	59	SKB_GSO_CB(skb)->encap_level = 0;
155e010e TH	60	__skb_pull(skb, tnl_hlen);
	61	skb_reset_mac_header(skb);
	62	skb_set_network_header(skb, skb_inner_network_offset(skb));
	63	skb->mac_len = skb_inner_network_offset(skb);
8bce6d7d	64	skb->protocol = new_protocol;
fdaefd62 AD	65
fdaefd62 AD	66	need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
4bcb877d	67	skb->encap_hdr_csum = need_csum;
fdaefd62 AD	68
fdaefd62 AD	69	remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
e585f236	70	skb->remcsum_offload = remcsum;
155e010e	71
22463876 AD	72	ufo = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
22463876 AD	73
4bcb877d TH	74	/* Try to offload checksum if possible */
4bcb877d TH	75	offload_csum = !!(need_csum &&
fdaefd62 AD	76	(skb->dev->features &
	77	(is_ipv6 ? (NETIF_F_HW_CSUM \| NETIF_F_IPV6_CSUM) :
	78	(NETIF_F_HW_CSUM \| NETIF_F_IP_CSUM))));
155e010e	79
bef3c6c9 AD	80	features &= skb->dev->hw_enc_features;
bef3c6c9 AD	81
7fbeffed AD	82	/* The only checksum offload we care about from here on out is the
	83	* outer one so strip the existing checksum feature flags and
	84	* instead set the flag based on our outer checksum offload value.
	85	*/
22463876	86	if (remcsum \|\| ufo) {
7fbeffed	87	features &= ~NETIF_F_CSUM_MASK;
22463876	88	if (!need_csum \|\| offload_csum)
7fbeffed AD	89	features \|= NETIF_F_HW_CSUM;
	90	}
	91
155e010e	92	/* segment inner packet. */
bef3c6c9	93	segs = gso_inner_segment(skb, features);
27446442	94	if (IS_ERR_OR_NULL(segs)) {
155e010e TH	95	skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
	96	mac_len);
	97	goto out;
	98	}
	99
	100	outer_hlen = skb_tnl_header_len(skb);
	101	udp_offset = outer_hlen - tnl_hlen;
	102	skb = segs;
	103	do {
dbef491e	104	__be16 len;
4bcb877d	105
fdaefd62	106	if (remcsum)
4bcb877d	107	skb->ip_summed = CHECKSUM_NONE;
fdaefd62 AD	108
	109	/* Set up inner headers if we are offloading inner checksum */
	110	if (skb->ip_summed == CHECKSUM_PARTIAL) {
4bcb877d TH	111	skb_reset_inner_headers(skb);
	112	skb->encapsulation = 1;
	113	}
155e010e TH	114
155e010e TH	115	skb->mac_len = mac_len;
4bcb877d	116	skb->protocol = protocol;
155e010e	117
dbef491e	118	__skb_push(skb, outer_hlen);
155e010e TH	119	skb_reset_mac_header(skb);
	120	skb_set_network_header(skb, mac_len);
	121	skb_set_transport_header(skb, udp_offset);
dbef491e	122	len = htons(skb->len - udp_offset);
155e010e	123	uh = udp_hdr(skb);
dbef491e	124	uh->len = len;
155e010e	125
4bcb877d TH	126	if (!need_csum)
	127	continue;
	128
08334824	129	uh->check = ~csum_fold(csum_add(partial, (__force __wsum)len));
155e010e	130
fdaefd62 AD	131	if (skb->encapsulation \|\| !offload_csum) {
fdaefd62 AD	132	uh->check = gso_make_checksum(skb, ~uh->check);
155e010e TH	133	if (uh->check == 0)
155e010e TH	134	uh->check = CSUM_MANGLED_0;
fdaefd62 AD	135	} else {
	136	skb->ip_summed = CHECKSUM_PARTIAL;
	137	skb->csum_start = skb_transport_header(skb) - skb->head;
	138	skb->csum_offset = offsetof(struct udphdr, check);
155e010e	139	}
155e010e TH	140	} while ((skb = skb->next));
	141	out:
	142	return segs;
	143	}
	144
8bce6d7d TH	145	struct sk_buff skb_udp_tunnel_segment(struct sk_buff skb,
	146	netdev_features_t features,
	147	bool is_ipv6)
	148	{
	149	__be16 protocol = skb->protocol;
	150	const struct net_offload **offloads;
	151	const struct net_offload *ops;
	152	struct sk_buff *segs = ERR_PTR(-EINVAL);
	153	struct sk_buff (gso_inner_segment)(struct sk_buff *skb,
	154	netdev_features_t features);
	155
	156	rcu_read_lock();
	157
	158	switch (skb->inner_protocol_type) {
	159	case ENCAP_TYPE_ETHER:
	160	protocol = skb->inner_protocol;
	161	gso_inner_segment = skb_mac_gso_segment;
	162	break;
	163	case ENCAP_TYPE_IPPROTO:
	164	offloads = is_ipv6 ? inet6_offloads : inet_offloads;
	165	ops = rcu_dereference(offloads[skb->inner_ipproto]);
	166	if (!ops \|\| !ops->callbacks.gso_segment)
	167	goto out_unlock;
	168	gso_inner_segment = ops->callbacks.gso_segment;
	169	break;
	170	default:
	171	goto out_unlock;
	172	}
	173
	174	segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment,
4bcb877d	175	protocol, is_ipv6);
8bce6d7d TH	176
	177	out_unlock:
	178	rcu_read_unlock();
	179
	180	return segs;
	181	}
	182
da5bab07 DB	183	static struct sk_buff udp4_ufo_fragment(struct sk_buff skb,
	184	netdev_features_t features)
	185	{
	186	struct sk_buff *segs = ERR_PTR(-EINVAL);
	187	unsigned int mss;
7a7ffbab	188	__wsum csum;
f71470b3 TH	189	struct udphdr *uh;
f71470b3 TH	190	struct iphdr *iph;
7a7ffbab WCC	191
7a7ffbab WCC	192	if (skb->encapsulation &&
0f4f4ffa TH	193	(skb_shinfo(skb)->gso_type &
0f4f4ffa TH	194	(SKB_GSO_UDP_TUNNEL\|SKB_GSO_UDP_TUNNEL_CSUM))) {
8bce6d7d	195	segs = skb_udp_tunnel_segment(skb, features, false);
7a7ffbab WCC	196	goto out;
7a7ffbab WCC	197	}
da5bab07	198
f71470b3 TH	199	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
	200	goto out;
	201
da5bab07 DB	202	mss = skb_shinfo(skb)->gso_size;
	203	if (unlikely(skb->len <= mss))
	204	goto out;
	205
	206	if (skb_gso_ok(skb, features \| NETIF_F_GSO_ROBUST)) {
	207	/* Packet is from an untrusted source, reset gso_segs. */
	208	int type = skb_shinfo(skb)->gso_type;
	209
	210	if (unlikely(type & ~(SKB_GSO_UDP \| SKB_GSO_DODGY \|
	211	SKB_GSO_UDP_TUNNEL \|
0f4f4ffa	212	SKB_GSO_UDP_TUNNEL_CSUM \|
e585f236	213	SKB_GSO_TUNNEL_REMCSUM \|
cb32f511	214	SKB_GSO_IPIP \|
59b93b41	215	SKB_GSO_GRE \| SKB_GSO_GRE_CSUM) \|\|
da5bab07 DB	216	!(type & (SKB_GSO_UDP))))
	217	goto out;
	218
	219	skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
	220
	221	segs = NULL;
	222	goto out;
	223	}
	224
7a7ffbab WCC	225	/* Do software UFO. Complete and fill in the UDP checksum as
	226	* HW cannot do checksum of UDP packets sent as multiple
	227	* IP fragments.
	228	*/
f71470b3 TH	229
	230	uh = udp_hdr(skb);
	231	iph = ip_hdr(skb);
	232
	233	uh->check = 0;
	234	csum = skb_checksum(skb, 0, skb->len, 0);
	235	uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum);
	236	if (uh->check == 0)
	237	uh->check = CSUM_MANGLED_0;
	238
7a7ffbab WCC	239	skb->ip_summed = CHECKSUM_NONE;
7a7ffbab WCC	240
22463876 AD	241	/* If there is no outer header we can fake a checksum offload
	242	* due to the fact that we have already done the checksum in
	243	* software prior to segmenting the frame.
	244	*/
	245	if (!skb->encap_hdr_csum)
	246	features \|= NETIF_F_HW_CSUM;
	247
da5bab07 DB	248	/* Fragment the skb. IP headers of the fragments are updated in
	249	* inet_gso_segment()
	250	*/
7a7ffbab	251	segs = skb_segment(skb, features);
da5bab07 DB	252	out:
	253	return segs;
	254	}
	255
787d7ac3	256	int udp_add_offload(struct net net, struct udp_offload uo)
b582ef09	257	{
b5aaab12	258	struct udp_offload_priv new_offload = kzalloc(sizeof(new_offload), GFP_ATOMIC);
b582ef09 OG	259
	260	if (!new_offload)
	261	return -ENOMEM;
	262
787d7ac3	263	write_pnet(&new_offload->net, net);
b582ef09 OG	264	new_offload->offload = uo;
	265
	266	spin_lock(&udp_offload_lock);
a664a4f7 SP	267	new_offload->next = udp_offload_base;
a664a4f7 SP	268	rcu_assign_pointer(udp_offload_base, new_offload);
b582ef09 OG	269	spin_unlock(&udp_offload_lock);
	270
	271	return 0;
	272	}
	273	EXPORT_SYMBOL(udp_add_offload);
	274
	275	static void udp_offload_free_routine(struct rcu_head *head)
	276	{
	277	struct udp_offload_priv *ou_priv = container_of(head, struct udp_offload_priv, rcu);
	278	kfree(ou_priv);
	279	}
	280
	281	void udp_del_offload(struct udp_offload *uo)
	282	{
	283	struct udp_offload_priv __rcu **head = &udp_offload_base;
	284	struct udp_offload_priv *uo_priv;
	285
	286	spin_lock(&udp_offload_lock);
	287
a664a4f7	288	uo_priv = udp_deref_protected(*head);
b582ef09	289	for (; uo_priv != NULL;
a664a4f7	290	uo_priv = udp_deref_protected(*head)) {
b582ef09	291	if (uo_priv->offload == uo) {
a664a4f7 SP	292	rcu_assign_pointer(*head,
a664a4f7 SP	293	udp_deref_protected(uo_priv->next));
b582ef09 OG	294	goto unlock;
	295	}
	296	head = &uo_priv->next;
	297	}
a1d0cd8e	298	pr_warn("udp_del_offload: didn't find offload for port %d\n", ntohs(uo->port));
b582ef09 OG	299	unlock:
b582ef09 OG	300	spin_unlock(&udp_offload_lock);
00db4124	301	if (uo_priv)
b582ef09 OG	302	call_rcu(&uo_priv->rcu, udp_offload_free_routine);
	303	}
	304	EXPORT_SYMBOL(udp_del_offload);
	305
57c67ff4 TH	306	struct sk_buff udp_gro_receive(struct sk_buff head, struct sk_buff *skb,
57c67ff4 TH	307	struct udphdr *uh)
b582ef09 OG	308	{
	309	struct udp_offload_priv *uo_priv;
	310	struct sk_buff p, *pp = NULL;
57c67ff4 TH	311	struct udphdr *uh2;
57c67ff4 TH	312	unsigned int off = skb_gro_offset(skb);
b582ef09 OG	313	int flush = 1;
b582ef09 OG	314
fac8e0f5	315	if (NAPI_GRO_CB(skb)->encap_mark \|\|
662880f4 TH	316	(skb->ip_summed != CHECKSUM_PARTIAL &&
	317	NAPI_GRO_CB(skb)->csum_cnt == 0 &&
	318	!NAPI_GRO_CB(skb)->csum_valid))
b582ef09 OG	319	goto out;
b582ef09 OG	320
fac8e0f5 JG	321	/* mark that this skb passed once through the tunnel gro layer */
fac8e0f5 JG	322	NAPI_GRO_CB(skb)->encap_mark = 1;
b582ef09 OG	323
	324	rcu_read_lock();
	325	uo_priv = rcu_dereference(udp_offload_base);
	326	for (; uo_priv != NULL; uo_priv = rcu_dereference(uo_priv->next)) {
787d7ac3 HFS	327	if (net_eq(read_pnet(&uo_priv->net), dev_net(skb->dev)) &&
787d7ac3 HFS	328	uo_priv->offload->port == uh->dest &&
b582ef09 OG	329	uo_priv->offload->callbacks.gro_receive)
	330	goto unflush;
	331	}
	332	goto out_unlock;
	333
	334	unflush:
	335	flush = 0;
	336
	337	for (p = *head; p; p = p->next) {
	338	if (!NAPI_GRO_CB(p)->same_flow)
	339	continue;
	340
	341	uh2 = (struct udphdr *)(p->data + off);
57c67ff4 TH	342
	343	/* Match ports and either checksums are either both zero
	344	* or nonzero.
	345	*/
	346	if (((u32 )&uh->source != (u32 )&uh2->source) \|\|
	347	(!uh->check ^ !uh2->check)) {
b582ef09 OG	348	NAPI_GRO_CB(p)->same_flow = 0;
	349	continue;
	350	}
	351	}
	352
	353	skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
6bae1d4c	354	skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr));
afe93325	355	NAPI_GRO_CB(skb)->proto = uo_priv->offload->ipproto;
a2b12f3c TH	356	pp = uo_priv->offload->callbacks.gro_receive(head, skb,
a2b12f3c TH	357	uo_priv->offload);
b582ef09 OG	358
	359	out_unlock:
	360	rcu_read_unlock();
	361	out:
	362	NAPI_GRO_CB(skb)->flush \|= flush;
	363	return pp;
	364	}
	365
57c67ff4 TH	366	static struct sk_buff udp4_gro_receive(struct sk_buff head,
	367	struct sk_buff *skb)
	368	{
	369	struct udphdr *uh = udp_gro_udphdr(skb);
	370
2abb7cdc TH	371	if (unlikely(!uh))
2abb7cdc TH	372	goto flush;
57c67ff4	373
2abb7cdc	374	/* Don't bother verifying checksum if we're going to flush anyway. */
2d8f7e2c	375	if (NAPI_GRO_CB(skb)->flush)
2abb7cdc TH	376	goto skip;
	377
	378	if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
	379	inet_gro_compute_pseudo))
	380	goto flush;
	381	else if (uh->check)
	382	skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
	383	inet_gro_compute_pseudo);
	384	skip:
efc98d08	385	NAPI_GRO_CB(skb)->is_ipv6 = 0;
57c67ff4	386	return udp_gro_receive(head, skb, uh);
2abb7cdc TH	387
	388	flush:
	389	NAPI_GRO_CB(skb)->flush = 1;
	390	return NULL;
57c67ff4 TH	391	}
	392
	393	int udp_gro_complete(struct sk_buff *skb, int nhoff)
b582ef09 OG	394	{
	395	struct udp_offload_priv *uo_priv;
	396	__be16 newlen = htons(skb->len - nhoff);
	397	struct udphdr uh = (struct udphdr )(skb->data + nhoff);
	398	int err = -ENOSYS;
	399
	400	uh->len = newlen;
	401
229740c6 JR	402	/* Set encapsulation before calling into inner gro_complete() functions
	403	* to make them set up the inner offsets.
	404	*/
	405	skb->encapsulation = 1;
	406
b582ef09 OG	407	rcu_read_lock();
	408
	409	uo_priv = rcu_dereference(udp_offload_base);
	410	for (; uo_priv != NULL; uo_priv = rcu_dereference(uo_priv->next)) {
787d7ac3 HFS	411	if (net_eq(read_pnet(&uo_priv->net), dev_net(skb->dev)) &&
787d7ac3 HFS	412	uo_priv->offload->port == uh->dest &&
b582ef09 OG	413	uo_priv->offload->callbacks.gro_complete)
	414	break;
	415	}
	416
00db4124	417	if (uo_priv) {
afe93325	418	NAPI_GRO_CB(skb)->proto = uo_priv->offload->ipproto;
a2b12f3c TH	419	err = uo_priv->offload->callbacks.gro_complete(skb,
	420	nhoff + sizeof(struct udphdr),
	421	uo_priv->offload);
afe93325	422	}
b582ef09 OG	423
b582ef09 OG	424	rcu_read_unlock();
6db93ea1 TH	425
	426	if (skb->remcsum_offload)
	427	skb_shinfo(skb)->gso_type \|= SKB_GSO_TUNNEL_REMCSUM;
	428
b582ef09 OG	429	return err;
	430	}
	431
72bb17b3	432	static int udp4_gro_complete(struct sk_buff *skb, int nhoff)
57c67ff4 TH	433	{
	434	const struct iphdr *iph = ip_hdr(skb);
	435	struct udphdr uh = (struct udphdr )(skb->data + nhoff);
	436
6db93ea1 TH	437	if (uh->check) {
6db93ea1 TH	438	skb_shinfo(skb)->gso_type \|= SKB_GSO_UDP_TUNNEL_CSUM;
57c67ff4 TH	439	uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr,
57c67ff4 TH	440	iph->daddr, 0);
6db93ea1 TH	441	} else {
	442	skb_shinfo(skb)->gso_type \|= SKB_GSO_UDP_TUNNEL;
	443	}
57c67ff4 TH	444
	445	return udp_gro_complete(skb, nhoff);
	446	}
	447
da5bab07 DB	448	static const struct net_offload udpv4_offload = {
da5bab07 DB	449	.callbacks = {
da5bab07	450	.gso_segment = udp4_ufo_fragment,
57c67ff4 TH	451	.gro_receive = udp4_gro_receive,
57c67ff4 TH	452	.gro_complete = udp4_gro_complete,
da5bab07 DB	453	},
	454	};
	455
	456	int __init udpv4_offload_init(void)
	457	{
	458	return inet_add_offload(&udpv4_offload, IPPROTO_UDP);
	459	}