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 * 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 18 static struct sk_buff **tcp6_gro_receive(struct sk_buff **head, 19 struct sk_buff *skb) 20 { 21 /* Don't bother verifying checksum if we're going to flush anyway. */ 22 if (!NAPI_GRO_CB(skb)->flush && 23 skb_gro_checksum_validate(skb, IPPROTO_TCP, 24 ip6_gro_compute_pseudo)) { 25 NAPI_GRO_CB(skb)->flush = 1; 26 return NULL; 27 } 28 29 return tcp_gro_receive(head, skb); 30 } 31 32 static int tcp6_gro_complete(struct sk_buff *skb, int thoff) 33 { 34 const struct ipv6hdr *iph = ipv6_hdr(skb); 35 struct tcphdr *th = tcp_hdr(skb); 36 37 th->check = ~tcp_v6_check(skb->len - thoff, &iph->saddr, 38 &iph->daddr, 0); 39 skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6; 40 41 return tcp_gro_complete(skb); 42 } 43 44 static struct sk_buff *tcp6_gso_segment(struct sk_buff *skb, 45 netdev_features_t features) 46 { 47 struct tcphdr *th; 48 49 if (!pskb_may_pull(skb, sizeof(*th))) 50 return ERR_PTR(-EINVAL); 51 52 if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) { 53 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 54 struct tcphdr *th = tcp_hdr(skb); 55 56 /* Set up pseudo header, usually expect stack to have done 57 * this. 58 */ 59 60 th->check = 0; 61 skb->ip_summed = CHECKSUM_PARTIAL; 62 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr); 63 } 64 65 return tcp_gso_segment(skb, features); 66 } 67 static const struct net_offload tcpv6_offload = { 68 .callbacks = { 69 .gso_segment = tcp6_gso_segment, 70 .gro_receive = tcp6_gro_receive, 71 .gro_complete = tcp6_gro_complete, 72 }, 73 }; 74 75 int __init tcpv6_offload_init(void) 76 { 77 return inet6_add_offload(&tcpv6_offload, IPPROTO_TCP); 78 } 79