141 lines
3.9 KiB
C
141 lines
3.9 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 <net/ip6_checksum.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;
|
|
|
|
if (likely(!skb->encapsulation)) {
|
|
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 *packet_start, *prevhdr;
|
|
u8 nexthdr;
|
|
u8 frag_hdr_sz = sizeof(struct frag_hdr);
|
|
int offset;
|
|
__wsum csum;
|
|
int tnl_hlen;
|
|
|
|
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 |
|
|
SKB_GSO_UDP_TUNNEL |
|
|
SKB_GSO_UDP_TUNNEL_CSUM |
|
|
SKB_GSO_GRE |
|
|
SKB_GSO_GRE_CSUM |
|
|
SKB_GSO_IPIP |
|
|
SKB_GSO_SIT |
|
|
SKB_GSO_MPLS) ||
|
|
!(type & (SKB_GSO_UDP))))
|
|
goto out;
|
|
|
|
skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
|
|
|
|
segs = NULL;
|
|
goto out;
|
|
}
|
|
|
|
if (skb->encapsulation && skb_shinfo(skb)->gso_type &
|
|
(SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
|
|
segs = skb_udp_tunnel_segment(skb, features);
|
|
else {
|
|
/* 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. */
|
|
tnl_hlen = skb_tnl_header_len(skb);
|
|
if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
|
|
if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
|
|
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 + tnl_hlen;
|
|
packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
|
|
memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
|
|
|
|
SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
|
|
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;
|
|
fptr->identification = skb_shinfo(skb)->ip6_frag_id;
|
|
|
|
/* 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 = {
|
|
.callbacks = {
|
|
.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);
|
|
}
|