gue: Receive side for Generic UDP Encapsulation

This patch adds support receiving for GUE packets in the fou module. The
fou module now supports direct foo-over-udp (no encapsulation header)
and GUE. To support this a type parameter is added to the fou netlink
parameters.

For a GUE socket we define gue_udp_recv, gue_gro_receive, and
gue_gro_complete to handle the specifics of the GUE protocol. Most
of the code to manage and configure sockets is common with the fou.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tom Herbert 2014-10-03 15:48:09 -07:00 committed by David S. Miller
parent efc98d08e1
commit 37dd024779
3 changed files with 217 additions and 9 deletions

23
include/net/gue.h Normal file
View file

@ -0,0 +1,23 @@
#ifndef __NET_GUE_H
#define __NET_GUE_H
struct guehdr {
union {
struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u8 hlen:4,
version:4;
#elif defined (__BIG_ENDIAN_BITFIELD)
__u8 version:4,
hlen:4;
#else
#error "Please fix <asm/byteorder.h>"
#endif
__u8 next_hdr;
__u16 flags;
};
__u32 word;
};
};
#endif

View file

@ -13,6 +13,7 @@ enum {
FOU_ATTR_PORT, /* u16 */
FOU_ATTR_AF, /* u8 */
FOU_ATTR_IPPROTO, /* u8 */
FOU_ATTR_TYPE, /* u8 */
__FOU_ATTR_MAX,
};
@ -27,6 +28,12 @@ enum {
__FOU_CMD_MAX,
};
enum {
FOU_ENCAP_UNSPEC,
FOU_ENCAP_DIRECT,
FOU_ENCAP_GUE,
};
#define FOU_CMD_MAX (__FOU_CMD_MAX - 1)
#endif /* _UAPI_LINUX_FOU_H */

View file

@ -7,6 +7,7 @@
#include <linux/types.h>
#include <linux/kernel.h>
#include <net/genetlink.h>
#include <net/gue.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/udp.h>
@ -27,6 +28,7 @@ struct fou {
};
struct fou_cfg {
u16 type;
u8 protocol;
struct udp_port_cfg udp_config;
};
@ -64,6 +66,41 @@ static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
sizeof(struct udphdr));
}
static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
{
struct fou *fou = fou_from_sock(sk);
size_t len;
struct guehdr *guehdr;
struct udphdr *uh;
if (!fou)
return 1;
len = sizeof(struct udphdr) + sizeof(struct guehdr);
if (!pskb_may_pull(skb, len))
goto drop;
uh = udp_hdr(skb);
guehdr = (struct guehdr *)&uh[1];
len += guehdr->hlen << 2;
if (!pskb_may_pull(skb, len))
goto drop;
if (guehdr->version != 0)
goto drop;
if (guehdr->flags) {
/* No support yet */
goto drop;
}
return fou_udp_encap_recv_deliver(skb, guehdr->next_hdr, len);
drop:
kfree_skb(skb);
return 0;
}
static struct sk_buff **fou_gro_receive(struct sk_buff **head,
struct sk_buff *skb)
{
@ -107,6 +144,112 @@ static int fou_gro_complete(struct sk_buff *skb, int nhoff)
return err;
}
static struct sk_buff **gue_gro_receive(struct sk_buff **head,
struct sk_buff *skb)
{
const struct net_offload **offloads;
const struct net_offload *ops;
struct sk_buff **pp = NULL;
struct sk_buff *p;
u8 proto;
struct guehdr *guehdr;
unsigned int hlen, guehlen;
unsigned int off;
int flush = 1;
off = skb_gro_offset(skb);
hlen = off + sizeof(*guehdr);
guehdr = skb_gro_header_fast(skb, off);
if (skb_gro_header_hard(skb, hlen)) {
guehdr = skb_gro_header_slow(skb, hlen, off);
if (unlikely(!guehdr))
goto out;
}
proto = guehdr->next_hdr;
rcu_read_lock();
offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
ops = rcu_dereference(offloads[proto]);
if (WARN_ON(!ops || !ops->callbacks.gro_receive))
goto out_unlock;
guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);
hlen = off + guehlen;
if (skb_gro_header_hard(skb, hlen)) {
guehdr = skb_gro_header_slow(skb, hlen, off);
if (unlikely(!guehdr))
goto out_unlock;
}
flush = 0;
for (p = *head; p; p = p->next) {
const struct guehdr *guehdr2;
if (!NAPI_GRO_CB(p)->same_flow)
continue;
guehdr2 = (struct guehdr *)(p->data + off);
/* Compare base GUE header to be equal (covers
* hlen, version, next_hdr, and flags.
*/
if (guehdr->word != guehdr2->word) {
NAPI_GRO_CB(p)->same_flow = 0;
continue;
}
/* Compare optional fields are the same. */
if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1],
guehdr->hlen << 2)) {
NAPI_GRO_CB(p)->same_flow = 0;
continue;
}
}
skb_gro_pull(skb, guehlen);
/* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
skb_gro_postpull_rcsum(skb, guehdr, guehlen);
pp = ops->callbacks.gro_receive(head, skb);
out_unlock:
rcu_read_unlock();
out:
NAPI_GRO_CB(skb)->flush |= flush;
return pp;
}
static int gue_gro_complete(struct sk_buff *skb, int nhoff)
{
const struct net_offload **offloads;
struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff);
const struct net_offload *ops;
unsigned int guehlen;
u8 proto;
int err = -ENOENT;
proto = guehdr->next_hdr;
guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);
rcu_read_lock();
offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
ops = rcu_dereference(offloads[proto]);
if (WARN_ON(!ops || !ops->callbacks.gro_complete))
goto out_unlock;
err = ops->callbacks.gro_complete(skb, nhoff + guehlen);
out_unlock:
rcu_read_unlock();
return err;
}
static int fou_add_to_port_list(struct fou *fou)
{
struct fou *fout;
@ -142,6 +285,28 @@ static void fou_release(struct fou *fou)
kfree(fou);
}
static int fou_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg)
{
udp_sk(sk)->encap_rcv = fou_udp_recv;
fou->protocol = cfg->protocol;
fou->udp_offloads.callbacks.gro_receive = fou_gro_receive;
fou->udp_offloads.callbacks.gro_complete = fou_gro_complete;
fou->udp_offloads.port = cfg->udp_config.local_udp_port;
fou->udp_offloads.ipproto = cfg->protocol;
return 0;
}
static int gue_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg)
{
udp_sk(sk)->encap_rcv = gue_udp_recv;
fou->udp_offloads.callbacks.gro_receive = gue_gro_receive;
fou->udp_offloads.callbacks.gro_complete = gue_gro_complete;
fou->udp_offloads.port = cfg->udp_config.local_udp_port;
return 0;
}
static int fou_create(struct net *net, struct fou_cfg *cfg,
struct socket **sockp)
{
@ -164,10 +329,24 @@ static int fou_create(struct net *net, struct fou_cfg *cfg,
sk = sock->sk;
/* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
fou->protocol = cfg->protocol;
fou->port = cfg->udp_config.local_udp_port;
udp_sk(sk)->encap_rcv = fou_udp_recv;
fou->port = cfg->udp_config.local_udp_port;
/* Initial for fou type */
switch (cfg->type) {
case FOU_ENCAP_DIRECT:
err = fou_encap_init(sk, fou, cfg);
if (err)
goto error;
break;
case FOU_ENCAP_GUE:
err = gue_encap_init(sk, fou, cfg);
if (err)
goto error;
break;
default:
err = -EINVAL;
goto error;
}
udp_sk(sk)->encap_type = 1;
udp_encap_enable();
@ -179,11 +358,6 @@ static int fou_create(struct net *net, struct fou_cfg *cfg,
sk->sk_allocation = GFP_ATOMIC;
fou->udp_offloads.callbacks.gro_receive = fou_gro_receive;
fou->udp_offloads.callbacks.gro_complete = fou_gro_complete;
fou->udp_offloads.port = cfg->udp_config.local_udp_port;
fou->udp_offloads.ipproto = cfg->protocol;
if (cfg->udp_config.family == AF_INET) {
err = udp_add_offload(&fou->udp_offloads);
if (err)
@ -240,6 +414,7 @@ static struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = {
[FOU_ATTR_PORT] = { .type = NLA_U16, },
[FOU_ATTR_AF] = { .type = NLA_U8, },
[FOU_ATTR_IPPROTO] = { .type = NLA_U8, },
[FOU_ATTR_TYPE] = { .type = NLA_U8, },
};
static int parse_nl_config(struct genl_info *info,
@ -267,6 +442,9 @@ static int parse_nl_config(struct genl_info *info,
if (info->attrs[FOU_ATTR_IPPROTO])
cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]);
if (info->attrs[FOU_ATTR_TYPE])
cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]);
return 0;
}