Release 4.14 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, gso_partial;
	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;
	bool need_ipsec;

	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.
         */
	if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL)
		partial = (__force __wsum)uh->len;
	else
		partial = (__force __wsum)htonl(skb->len);
	partial = csum_sub(csum_unfold(uh->check), partial);

	/* 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;

	need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb));
	/* Try to offload checksum if possible */
	offload_csum = !!(need_csum &&
			  !need_ipsec &&
			  (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) {
		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;
	}

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

	outer_hlen = skb_tnl_header_len(skb);
	udp_offset = outer_hlen - tnl_hlen;
	skb = segs;
	do {
		unsigned int 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 = skb->len - udp_offset;
		uh = udp_hdr(skb);

		/* If we are only performing partial GSO the inner header
                 * will be using a length value equal to only one MSS sized
                 * segment instead of the entire frame.
                 */
		if (gso_partial && skb_is_gso(skb)) {
			uh->len = htons(skb_shinfo(skb)->gso_size +
					SKB_GSO_CB(skb)->data_offset +
					skb->head - (unsigned char *)uh);
		} else {
			uh->len = htons(len);
		}

		if (!need_csum)
			continue;

		uh->check = ~csum_fold(csum_add(partial,
				       (__force __wsum)htonl(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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Tom Herbert
165
100.00%
2
100.00%
Total
165
100.00%
2
100.00%


EXPORT_SYMBOL(skb_udp_tunnel_segment);



static struct sk_buff *udp4_tunnel_segment(struct sk_buff *skb,
					   netdev_features_t features)
{
	struct sk_buff *segs = ERR_PTR(-EINVAL);

	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);

	return segs;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Daniel Borkmann
29
46.77%
1
20.00%
Wei-Chun Chao
24
38.71%
1
20.00%
Tom Herbert
8
12.90%
2
40.00%
David S. Miller
1
1.61%
1
20.00%
Total
62
100.00%
5
100.00%



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 = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb);

out_unlock:
	rcu_read_unlock();
out:
	NAPI_GRO_CB(skb)->flush |= flush;
	return pp;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Or Gerlitz
213
69.38%
1
12.50%
Tom Herbert
85
27.69%
4
50.00%
Hannes Frederic Sowa
3
0.98%
1
12.50%
Sabrina Dubroca
3
0.98%
1
12.50%
Jesse Gross
3
0.98%
1
12.50%
Total
307
100.00%
8
100.00%


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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Tom Herbert
128
99.22%
4
80.00%
Or Gerlitz
1
0.78%
1
20.00%
Total
129
100.00%
5
100.00%



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;

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

	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;

	return err;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Or Gerlitz
86
59.31%
1
16.67%
Tom Herbert
49
33.79%
3
50.00%
Jarno Rajahalme
7
4.83%
1
16.67%
Hannes Frederic Sowa
3
2.07%
1
16.67%
Total
145
100.00%
6
100.00%


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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Tom Herbert
105
99.06%
3
75.00%
Eric Dumazet
1
0.94%
1
25.00%
Total
106
100.00%
4
100.00%


static const struct net_offload udpv4_offload = {
	.callbacks = {
		.gso_segment = udp4_tunnel_segment,
		.gro_receive  =	udp4_gro_receive,
		.gro_complete =	udp4_gro_complete,
        },
};



int __init udpv4_offload_init(void)
{
	return inet_add_offload(&udpv4_offload, IPPROTO_UDP);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Daniel Borkmann
17
100.00%
1
100.00%
Total
17
100.00%
1
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Tom Herbert
939
56.13%
14
40.00%
Or Gerlitz
322
19.25%
1
2.86%
Alexander Duyck
263
15.72%
8
22.86%
Daniel Borkmann
59
3.53%
1
2.86%
Wei-Chun Chao
24
1.43%
1
2.86%
Ansis Atteka
21
1.26%
1
2.86%
Steffen Klassert
17
1.02%
1
2.86%
Jarno Rajahalme
7
0.42%
1
2.86%
Hannes Frederic Sowa
6
0.36%
1
2.86%
Alexey Kodanev
5
0.30%
1
2.86%
Jesse Gross
3
0.18%
1
2.86%
Sabrina Dubroca
3
0.18%
1
2.86%
David S. Miller
2
0.12%
1
2.86%
Himangi Saraogi
1
0.06%
1
2.86%
Eric Dumazet
1
0.06%
1
2.86%
Total
1673
100.00%
35
100.00%
Directory: net/ipv4

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.