linux/net/ipv6/udp_offload.c
Vlad Yasevich c6b641a4c6 ipv6: Pull IPv6 GSO registration out of the module
Sing GSO support is now separate, pull it out of the module
and make it its own init call.
Remove the cleanup functions as they are no longer called.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-15 17:39:24 -05:00

117 lines
3.2 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.
*
* UDPv6 GSO support
*/
#include <linux/skbuff.h>
#include <net/protocol.h>
#include <net/ipv6.h>
#include <net/udp.h>
#include "ip6_offload.h"
static int udp6_ufo_send_check(struct sk_buff *skb)
{
const struct ipv6hdr *ipv6h;
struct udphdr *uh;
if (!pskb_may_pull(skb, sizeof(*uh)))
return -EINVAL;
ipv6h = ipv6_hdr(skb);
uh = udp_hdr(skb);
uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
IPPROTO_UDP, 0);
skb->csum_start = skb_transport_header(skb) - skb->head;
skb->csum_offset = offsetof(struct udphdr, check);
skb->ip_summed = CHECKSUM_PARTIAL;
return 0;
}
static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
netdev_features_t features)
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
unsigned int mss;
unsigned int unfrag_ip6hlen, unfrag_len;
struct frag_hdr *fptr;
u8 *mac_start, *prevhdr;
u8 nexthdr;
u8 frag_hdr_sz = sizeof(struct frag_hdr);
int offset;
__wsum csum;
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) ||
!(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.
*/
offset = skb_checksum_start_offset(skb);
csum = skb_checksum(skb, offset, skb->len - offset, 0);
offset += skb->csum_offset;
*(__sum16 *)(skb->data + offset) = csum_fold(csum);
skb->ip_summed = CHECKSUM_NONE;
/* Check if there is enough headroom to insert fragment header. */
if ((skb_mac_header(skb) < skb->head + frag_hdr_sz) &&
pskb_expand_head(skb, frag_hdr_sz, 0, GFP_ATOMIC))
goto out;
/* Find the unfragmentable header and shift it left by frag_hdr_sz
* bytes to insert fragment header.
*/
unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
nexthdr = *prevhdr;
*prevhdr = NEXTHDR_FRAGMENT;
unfrag_len = skb_network_header(skb) - skb_mac_header(skb) +
unfrag_ip6hlen;
mac_start = skb_mac_header(skb);
memmove(mac_start-frag_hdr_sz, mac_start, unfrag_len);
skb->mac_header -= frag_hdr_sz;
skb->network_header -= frag_hdr_sz;
fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
fptr->nexthdr = nexthdr;
fptr->reserved = 0;
ipv6_select_ident(fptr, (struct rt6_info *)skb_dst(skb));
/* Fragment the skb. ipv6 header and the remaining fields of the
* fragment header are updated in ipv6_gso_segment()
*/
segs = skb_segment(skb, features);
out:
return segs;
}
static const struct net_offload udpv6_offload = {
.gso_send_check = udp6_ufo_send_check,
.gso_segment = udp6_ufo_fragment,
};
int __init udp_offload_init(void)
{
return inet6_add_offload(&udpv6_offload, IPPROTO_UDP);
}