269 lines
6.2 KiB
C
269 lines
6.2 KiB
C
|
/*
|
||
|
|
* IPV4 GSO/GRO offload support
|
||
|
|
* Linux INET 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.
|
||
|
|
*
|
||
|
|
* GRE GSO support
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/skbuff.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
#include <net/protocol.h>
|
||
|
|
#include <net/gre.h>
|
||
|
|
|
||
|
|
static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
|
||
|
|
netdev_features_t features)
|
||
|
|
{
|
||
|
|
struct sk_buff *segs = ERR_PTR(-EINVAL);
|
||
|
|
netdev_features_t enc_features;
|
||
|
|
int ghl;
|
||
|
|
struct gre_base_hdr *greh;
|
||
|
|
u16 mac_offset = skb->mac_header;
|
||
|
|
int mac_len = skb->mac_len;
|
||
|
|
__be16 protocol = skb->protocol;
|
||
|
|
int tnl_hlen;
|
||
|
|
bool csum;
|
||
|
|
|
||
|
|
if (unlikely(skb_shinfo(skb)->gso_type &
|
||
|
|
~(SKB_GSO_TCPV4 |
|
||
|
|
SKB_GSO_TCPV6 |
|
||
|
|
SKB_GSO_UDP |
|
||
|
|
SKB_GSO_DODGY |
|
||
|
|
SKB_GSO_TCP_ECN |
|
||
|
|
SKB_GSO_GRE |
|
||
|
|
SKB_GSO_GRE_CSUM |
|
||
|
|
SKB_GSO_IPIP)))
|
||
|
|
goto out;
|
||
|
|
|
||
|
|
if (!skb->encapsulation)
|
||
|
|
goto out;
|
||
|
|
|
||
|
|
if (unlikely(!pskb_may_pull(skb, sizeof(*greh))))
|
||
|
|
goto out;
|
||
|
|
|
||
|
|
greh = (struct gre_base_hdr *)skb_transport_header(skb);
|
||
|
|
|
||
|
|
ghl = skb_inner_mac_header(skb) - skb_transport_header(skb);
|
||
|
|
if (unlikely(ghl < sizeof(*greh)))
|
||
|
|
goto out;
|
||
|
|
|
||
|
|
csum = !!(greh->flags & GRE_CSUM);
|
||
|
|
if (csum)
|
||
|
|
skb->encap_hdr_csum = 1;
|
||
|
|
|
||
|
|
/* setup inner skb. */
|
||
|
|
skb->protocol = greh->protocol;
|
||
|
|
skb->encapsulation = 0;
|
||
|
|
|
||
|
|
if (unlikely(!pskb_may_pull(skb, ghl)))
|
||
|
|
goto out;
|
||
|
|
|
||
|
|
__skb_pull(skb, ghl);
|
||
|
|
skb_reset_mac_header(skb);
|
||
|
|
skb_set_network_header(skb, skb_inner_network_offset(skb));
|
||
|
|
skb->mac_len = skb_inner_network_offset(skb);
|
||
|
|
|
||
|
|
/* segment inner packet. */
|
||
|
|
enc_features = skb->dev->hw_enc_features & features;
|
||
|
|
segs = skb_mac_gso_segment(skb, enc_features);
|
||
|
|
if (IS_ERR_OR_NULL(segs)) {
|
||
|
|
skb_gso_error_unwind(skb, protocol, ghl, mac_offset, mac_len);
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
|
||
|
|
skb = segs;
|
||
|
|
tnl_hlen = skb_tnl_header_len(skb);
|
||
|
|
do {
|
||
|
|
__skb_push(skb, ghl);
|
||
|
|
if (csum) {
|
||
|
|
__be32 *pcsum;
|
||
|
|
|
||
|
|
if (skb_has_shared_frag(skb)) {
|
||
|
|
int err;
|
||
|
|
|
||
|
|
err = __skb_linearize(skb);
|
||
|
|
if (err) {
|
||
|
|
kfree_skb_list(segs);
|
||
|
|
segs = ERR_PTR(err);
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
skb_reset_transport_header(skb);
|
||
|
|
|
||
|
|
greh = (struct gre_base_hdr *)
|
||
|
|
skb_transport_header(skb);
|
||
|
|
pcsum = (__be32 *)(greh + 1);
|
||
|
|
*pcsum = 0;
|
||
|
|
*(__sum16 *)pcsum = gso_make_checksum(skb, 0);
|
||
|
|
}
|
||
|
|
__skb_push(skb, tnl_hlen - ghl);
|
||
|
|
|
||
|
|
skb_reset_inner_headers(skb);
|
||
|
|
skb->encapsulation = 1;
|
||
|
|
|
||
|
|
skb_reset_mac_header(skb);
|
||
|
|
skb_set_network_header(skb, mac_len);
|
||
|
|
skb->mac_len = mac_len;
|
||
|
|
skb->protocol = protocol;
|
||
|
|
} while ((skb = skb->next));
|
||
|
|
out:
|
||
|
|
return segs;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct sk_buff **gre_gro_receive(struct sk_buff **head,
|
||
|
|
struct sk_buff *skb)
|
||
|
|
{
|
||
|
|
struct sk_buff **pp = NULL;
|
||
|
|
struct sk_buff *p;
|
||
|
|
const struct gre_base_hdr *greh;
|
||
|
|
unsigned int hlen, grehlen;
|
||
|
|
unsigned int off;
|
||
|
|
int flush = 1;
|
||
|
|
struct packet_offload *ptype;
|
||
|
|
__be16 type;
|
||
|
|
|
||
|
|
off = skb_gro_offset(skb);
|
||
|
|
hlen = off + sizeof(*greh);
|
||
|
|
greh = skb_gro_header_fast(skb, off);
|
||
|
|
if (skb_gro_header_hard(skb, hlen)) {
|
||
|
|
greh = skb_gro_header_slow(skb, hlen, off);
|
||
|
|
if (unlikely(!greh))
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Only support version 0 and K (key), C (csum) flags. Note that
|
||
|
|
* although the support for the S (seq#) flag can be added easily
|
||
|
|
* for GRO, this is problematic for GSO hence can not be enabled
|
||
|
|
* here because a GRO pkt may end up in the forwarding path, thus
|
||
|
|
* requiring GSO support to break it up correctly.
|
||
|
|
*/
|
||
|
|
if ((greh->flags & ~(GRE_KEY|GRE_CSUM)) != 0)
|
||
|
|
goto out;
|
||
|
|
|
||
|
|
type = greh->protocol;
|
||
|
|
|
||
|
|
rcu_read_lock();
|
||
|
|
ptype = gro_find_receive_by_type(type);
|
||
|
|
if (ptype == NULL)
|
||
|
|
goto out_unlock;
|
||
|
|
|
||
|
|
grehlen = GRE_HEADER_SECTION;
|
||
|
|
|
||
|
|
if (greh->flags & GRE_KEY)
|
||
|
|
grehlen += GRE_HEADER_SECTION;
|
||
|
|
|
||
|
|
if (greh->flags & GRE_CSUM)
|
||
|
|
grehlen += GRE_HEADER_SECTION;
|
||
|
|
|
||
|
|
hlen = off + grehlen;
|
||
|
|
if (skb_gro_header_hard(skb, hlen)) {
|
||
|
|
greh = skb_gro_header_slow(skb, hlen, off);
|
||
|
|
if (unlikely(!greh))
|
||
|
|
goto out_unlock;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Don't bother verifying checksum if we're going to flush anyway. */
|
||
|
|
if ((greh->flags & GRE_CSUM) && !NAPI_GRO_CB(skb)->flush) {
|
||
|
|
if (skb_gro_checksum_simple_validate(skb))
|
||
|
|
goto out_unlock;
|
||
|
|
|
||
|
|
skb_gro_checksum_try_convert(skb, IPPROTO_GRE, 0,
|
||
|
|
null_compute_pseudo);
|
||
|
|
}
|
||
|
|
|
||
|
|
flush = 0;
|
||
|
|
|
||
|
|
for (p = *head; p; p = p->next) {
|
||
|
|
const struct gre_base_hdr *greh2;
|
||
|
|
|
||
|
|
if (!NAPI_GRO_CB(p)->same_flow)
|
||
|
|
continue;
|
||
|
|
|
||
|
|
/* The following checks are needed to ensure only pkts
|
||
|
|
* from the same tunnel are considered for aggregation.
|
||
|
|
* The criteria for "the same tunnel" includes:
|
||
|
|
* 1) same version (we only support version 0 here)
|
||
|
|
* 2) same protocol (we only support ETH_P_IP for now)
|
||
|
|
* 3) same set of flags
|
||
|
|
* 4) same key if the key field is present.
|
||
|
|
*/
|
||
|
|
greh2 = (struct gre_base_hdr *)(p->data + off);
|
||
|
|
|
||
|
|
if (greh2->flags != greh->flags ||
|
||
|
|
greh2->protocol != greh->protocol) {
|
||
|
|
NAPI_GRO_CB(p)->same_flow = 0;
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
if (greh->flags & GRE_KEY) {
|
||
|
|
/* compare keys */
|
||
|
|
if (*(__be32 *)(greh2+1) != *(__be32 *)(greh+1)) {
|
||
|
|
NAPI_GRO_CB(p)->same_flow = 0;
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
skb_gro_pull(skb, grehlen);
|
||
|
|
|
||
|
|
/* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
|
||
|
|
skb_gro_postpull_rcsum(skb, greh, grehlen);
|
||
|
|
|
||
|
|
pp = ptype->callbacks.gro_receive(head, skb);
|
||
|
|
|
||
|
|
out_unlock:
|
||
|
|
rcu_read_unlock();
|
||
|
|
out:
|
||
|
|
NAPI_GRO_CB(skb)->flush |= flush;
|
||
|
|
|
||
|
|
return pp;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int gre_gro_complete(struct sk_buff *skb, int nhoff)
|
||
|
|
{
|
||
|
|
struct gre_base_hdr *greh = (struct gre_base_hdr *)(skb->data + nhoff);
|
||
|
|
struct packet_offload *ptype;
|
||
|
|
unsigned int grehlen = sizeof(*greh);
|
||
|
|
int err = -ENOENT;
|
||
|
|
__be16 type;
|
||
|
|
|
||
|
|
skb->encapsulation = 1;
|
||
|
|
skb_shinfo(skb)->gso_type = SKB_GSO_GRE;
|
||
|
|
|
||
|
|
type = greh->protocol;
|
||
|
|
if (greh->flags & GRE_KEY)
|
||
|
|
grehlen += GRE_HEADER_SECTION;
|
||
|
|
|
||
|
|
if (greh->flags & GRE_CSUM)
|
||
|
|
grehlen += GRE_HEADER_SECTION;
|
||
|
|
|
||
|
|
rcu_read_lock();
|
||
|
|
ptype = gro_find_complete_by_type(type);
|
||
|
|
if (ptype != NULL)
|
||
|
|
err = ptype->callbacks.gro_complete(skb, nhoff + grehlen);
|
||
|
|
|
||
|
|
rcu_read_unlock();
|
||
|
|
|
||
|
|
skb_set_inner_mac_header(skb, nhoff + grehlen);
|
||
|
|
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const struct net_offload gre_offload = {
|
||
|
|
.callbacks = {
|
||
|
|
.gso_segment = gre_gso_segment,
|
||
|
|
.gro_receive = gre_gro_receive,
|
||
|
|
.gro_complete = gre_gro_complete,
|
||
|
|
},
|
||
|
|
};
|
||
|
|
|
||
|
|
static int __init gre_offload_init(void)
|
||
|
|
{
|
||
|
|
return inet_add_offload(&gre_offload, IPPROTO_GRE);
|
||
|
|
}
|
||
|
|
device_initcall(gre_offload_init);
|