blob: 2ec6bf6a0aa002d6c21468d090767736161a5d1b [file] [log] [blame]
Vlad Yasevich8663e022012-11-15 08:49:17 +00001/*
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 * TCPv6 GSO/GRO support
11 */
12#include <linux/skbuff.h>
13#include <net/protocol.h>
14#include <net/tcp.h>
15#include <net/ip6_checksum.h>
16#include "ip6_offload.h"
17
18static int tcp_v6_gso_send_check(struct sk_buff *skb)
19{
20 const struct ipv6hdr *ipv6h;
21 struct tcphdr *th;
22
23 if (!pskb_may_pull(skb, sizeof(*th)))
24 return -EINVAL;
25
26 ipv6h = ipv6_hdr(skb);
27 th = tcp_hdr(skb);
28
29 th->check = 0;
30 skb->ip_summed = CHECKSUM_PARTIAL;
31 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
32 return 0;
33}
34
35static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
36 struct sk_buff *skb)
37{
38 const struct ipv6hdr *iph = skb_gro_network_header(skb);
39 __wsum wsum;
40 __sum16 sum;
41
42 switch (skb->ip_summed) {
43 case CHECKSUM_COMPLETE:
44 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
45 skb->csum)) {
46 skb->ip_summed = CHECKSUM_UNNECESSARY;
47 break;
48 }
49flush:
50 NAPI_GRO_CB(skb)->flush = 1;
51 return NULL;
52
53 case CHECKSUM_NONE:
54 wsum = ~csum_unfold(csum_ipv6_magic(&iph->saddr, &iph->daddr,
55 skb_gro_len(skb),
56 IPPROTO_TCP, 0));
57 sum = csum_fold(skb_checksum(skb,
58 skb_gro_offset(skb),
59 skb_gro_len(skb),
60 wsum));
61 if (sum)
62 goto flush;
63
64 skb->ip_summed = CHECKSUM_UNNECESSARY;
65 break;
66 }
67
68 return tcp_gro_receive(head, skb);
69}
70
71static int tcp6_gro_complete(struct sk_buff *skb)
72{
73 const struct ipv6hdr *iph = ipv6_hdr(skb);
74 struct tcphdr *th = tcp_hdr(skb);
75
76 th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
77 &iph->saddr, &iph->daddr, 0);
78 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
79
80 return tcp_gro_complete(skb);
81}
82
83static const struct net_offload tcpv6_offload = {
Vlad Yasevichf191a1d2012-11-15 08:49:23 +000084 .callbacks = {
85 .gso_send_check = tcp_v6_gso_send_check,
86 .gso_segment = tcp_tso_segment,
87 .gro_receive = tcp6_gro_receive,
88 .gro_complete = tcp6_gro_complete,
89 },
Vlad Yasevich8663e022012-11-15 08:49:17 +000090};
91
92int __init tcpv6_offload_init(void)
93{
94 return inet6_add_offload(&tcpv6_offload, IPPROTO_TCP);
95}