net: Changes to ip_tunnel to support foo-over-udp encapsulation

This patch changes IP tunnel to support (secondary) encapsulation,
Foo-over-UDP. Changes include:

1) Adding tun_hlen as the tunnel header length, encap_hlen as the
   encapsulation header length, and hlen becomes the grand total
   of these.
2) Added common netlink define to support FOU encapsulation.
3) Routines to perform FOU encapsulation.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tom Herbert 2014-09-17 12:25:58 -07:00 committed by David S. Miller
parent afe93325bc
commit 5632848653
3 changed files with 120 additions and 2 deletions

View File

@ -10,6 +10,7 @@
#include <net/gro_cells.h>
#include <net/inet_ecn.h>
#include <net/ip.h>
#include <net/netns/generic.h>
#include <net/rtnetlink.h>
#if IS_ENABLED(CONFIG_IPV6)
@ -31,6 +32,13 @@ struct ip_tunnel_6rd_parm {
};
#endif
struct ip_tunnel_encap {
__u16 type;
__u16 flags;
__be16 sport;
__be16 dport;
};
struct ip_tunnel_prl_entry {
struct ip_tunnel_prl_entry __rcu *next;
__be32 addr;
@ -56,13 +64,18 @@ struct ip_tunnel {
/* These four fields used only by GRE */
__u32 i_seqno; /* The last seen seqno */
__u32 o_seqno; /* The last output seqno */
int hlen; /* Precalculated header length */
int tun_hlen; /* Precalculated header length */
int mlink;
struct ip_tunnel_dst __percpu *dst_cache;
struct ip_tunnel_parm parms;
int encap_hlen; /* Encap header length (FOU,GUE) */
struct ip_tunnel_encap encap;
int hlen; /* tun_hlen + encap_hlen */
/* for SIT */
#ifdef CONFIG_IPV6_SIT_6RD
struct ip_tunnel_6rd_parm ip6rd;
@ -114,6 +127,8 @@ void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops);
void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
const struct iphdr *tnl_params, const u8 protocol);
int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd);
int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
u8 *protocol, struct flowi4 *fl4);
int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu);
struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev,
@ -131,6 +146,8 @@ int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
struct ip_tunnel_parm *p);
void ip_tunnel_setup(struct net_device *dev, int net_id);
void ip_tunnel_dst_reset_all(struct ip_tunnel *t);
int ip_tunnel_encap_setup(struct ip_tunnel *t,
struct ip_tunnel_encap *ipencap);
/* Extract dsfield from inner protocol */
static inline u8 ip_tunnel_get_dsfield(const struct iphdr *iph,

View File

@ -53,10 +53,22 @@ enum {
IFLA_IPTUN_6RD_RELAY_PREFIX,
IFLA_IPTUN_6RD_PREFIXLEN,
IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
IFLA_IPTUN_ENCAP_TYPE,
IFLA_IPTUN_ENCAP_FLAGS,
IFLA_IPTUN_ENCAP_SPORT,
IFLA_IPTUN_ENCAP_DPORT,
__IFLA_IPTUN_MAX,
};
#define IFLA_IPTUN_MAX (__IFLA_IPTUN_MAX - 1)
enum tunnel_encap_types {
TUNNEL_ENCAP_NONE,
TUNNEL_ENCAP_FOU,
};
#define TUNNEL_ENCAP_FLAG_CSUM (1<<0)
#define TUNNEL_ENCAP_FLAG_CSUM6 (1<<1)
/* SIT-mode i_flags */
#define SIT_ISATAP 0x0001

View File

@ -55,6 +55,7 @@
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/rtnetlink.h>
#include <net/udp.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
@ -487,6 +488,91 @@ drop:
}
EXPORT_SYMBOL_GPL(ip_tunnel_rcv);
static int ip_encap_hlen(struct ip_tunnel_encap *e)
{
switch (e->type) {
case TUNNEL_ENCAP_NONE:
return 0;
case TUNNEL_ENCAP_FOU:
return sizeof(struct udphdr);
default:
return -EINVAL;
}
}
int ip_tunnel_encap_setup(struct ip_tunnel *t,
struct ip_tunnel_encap *ipencap)
{
int hlen;
memset(&t->encap, 0, sizeof(t->encap));
hlen = ip_encap_hlen(ipencap);
if (hlen < 0)
return hlen;
t->encap.type = ipencap->type;
t->encap.sport = ipencap->sport;
t->encap.dport = ipencap->dport;
t->encap.flags = ipencap->flags;
t->encap_hlen = hlen;
t->hlen = t->encap_hlen + t->tun_hlen;
return 0;
}
EXPORT_SYMBOL_GPL(ip_tunnel_encap_setup);
static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
size_t hdr_len, u8 *protocol, struct flowi4 *fl4)
{
struct udphdr *uh;
__be16 sport;
bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM);
int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
skb = iptunnel_handle_offloads(skb, csum, type);
if (IS_ERR(skb))
return PTR_ERR(skb);
/* Get length and hash before making space in skb */
sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
skb, 0, 0, false);
skb_push(skb, hdr_len);
skb_reset_transport_header(skb);
uh = udp_hdr(skb);
uh->dest = e->dport;
uh->source = sport;
uh->len = htons(skb->len);
uh->check = 0;
udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb,
fl4->saddr, fl4->daddr, skb->len);
*protocol = IPPROTO_UDP;
return 0;
}
int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
u8 *protocol, struct flowi4 *fl4)
{
switch (t->encap.type) {
case TUNNEL_ENCAP_NONE:
return 0;
case TUNNEL_ENCAP_FOU:
return fou_build_header(skb, &t->encap, t->encap_hlen,
protocol, fl4);
default:
return -EINVAL;
}
}
EXPORT_SYMBOL(ip_tunnel_encap);
static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb,
struct rtable *rt, __be16 df)
{
@ -536,7 +622,7 @@ static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb,
}
void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
const struct iphdr *tnl_params, const u8 protocol)
const struct iphdr *tnl_params, u8 protocol)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
const struct iphdr *inner_iph;
@ -617,6 +703,9 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
init_tunnel_flow(&fl4, protocol, dst, tnl_params->saddr,
tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link);
if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0)
goto tx_error;
rt = connected ? tunnel_rtable_get(tunnel, 0, &fl4.saddr) : NULL;
if (!rt) {