linux/net/ipv6/tcpv6_offload.c
Tom Herbert d020f8f733 tcp: move logic out of tcp_v[64]_gso_send_check
In tcp_v[46]_gso_send_check the TCP checksum is initialized to the
pseudo header checksum using __tcp_v[46]_send_check. We can move this
logic into new tcp[46]_gso_segment functions to be done when
ip_summed != CHECKSUM_PARTIAL (ip_summed == CHECKSUM_PARTIAL should be
the common case, possibly always true when taking GSO path). After this
change tcp_v[46]_gso_send_check is no-op.

Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 00:22:46 -04:00

85 lines
2.1 KiB
C

/*
* IPV6 GSO/GRO offload support
* Linux INET6 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.
*
* TCPv6 GSO/GRO support
*/
#include <linux/skbuff.h>
#include <net/protocol.h>
#include <net/tcp.h>
#include <net/ip6_checksum.h>
#include "ip6_offload.h"
static int tcp_v6_gso_send_check(struct sk_buff *skb)
{
return 0;
}
static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
struct sk_buff *skb)
{
/* Don't bother verifying checksum if we're going to flush anyway. */
if (!NAPI_GRO_CB(skb)->flush &&
skb_gro_checksum_validate(skb, IPPROTO_TCP,
ip6_gro_compute_pseudo)) {
NAPI_GRO_CB(skb)->flush = 1;
return NULL;
}
return tcp_gro_receive(head, skb);
}
static int tcp6_gro_complete(struct sk_buff *skb, int thoff)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
struct tcphdr *th = tcp_hdr(skb);
th->check = ~tcp_v6_check(skb->len - thoff, &iph->saddr,
&iph->daddr, 0);
skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
return tcp_gro_complete(skb);
}
struct sk_buff *tcp6_gso_segment(struct sk_buff *skb,
netdev_features_t features)
{
struct tcphdr *th;
if (!pskb_may_pull(skb, sizeof(*th)))
return ERR_PTR(-EINVAL);
if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
struct tcphdr *th = tcp_hdr(skb);
/* Set up pseudo header, usually expect stack to have done
* this.
*/
th->check = 0;
skb->ip_summed = CHECKSUM_PARTIAL;
__tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
}
return tcp_gso_segment(skb, features);
}
static const struct net_offload tcpv6_offload = {
.callbacks = {
.gso_send_check = tcp_v6_gso_send_check,
.gso_segment = tcp6_gso_segment,
.gro_receive = tcp6_gro_receive,
.gro_complete = tcp6_gro_complete,
},
};
int __init tcpv6_offload_init(void)
{
return inet6_add_offload(&tcpv6_offload, IPPROTO_TCP);
}