linux/net/ipv6/fou6.c
Arnd Bergmann fabb13db44 fou: add Kconfig options for IPv6 support
A previous patch added the fou6.ko module, but that failed to link
in a couple of configurations:

net/built-in.o: In function `ip6_tnl_encap_add_fou_ops':
net/ipv6/fou6.c:88: undefined reference to `ip6_tnl_encap_add_ops'
net/ipv6/fou6.c:94: undefined reference to `ip6_tnl_encap_add_ops'
net/ipv6/fou6.c:97: undefined reference to `ip6_tnl_encap_del_ops'
net/built-in.o: In function `ip6_tnl_encap_del_fou_ops':
net/ipv6/fou6.c:106: undefined reference to `ip6_tnl_encap_del_ops'
net/ipv6/fou6.c:107: undefined reference to `ip6_tnl_encap_del_ops'

If CONFIG_IPV6=m, ip6_tnl_encap_add_ops/ip6_tnl_encap_del_ops
are in a module, but fou6.c can still be built-in, and that
obviously fails to link.

Also, if CONFIG_IPV6=y, but CONFIG_IPV6_TUNNEL=m or
CONFIG_IPV6_TUNNEL=n, the same problem happens for a different
reason.

This adds two new silent Kconfig symbols to work around both
problems:

- CONFIG_IPV6_FOU is now always set to 'm' if either CONFIG_NET_FOU=m
  or CONFIG_IPV6=m
- CONFIG_IPV6_FOU_TUNNEL is set implicitly when IPV6_FOU is enabled
  and NET_FOU_IP_TUNNELS is also turned out, and it will ensure
  that CONFIG_IPV6_TUNNEL is also available.

The options could be made user-visible as well, to give additional
room for configuration, but it seems easier not to bother users
with more choice here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: aa3463d65e ("fou: Add encap ops for IPv6 tunnels")
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-29 22:24:21 -07:00

141 lines
2.9 KiB
C

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/udp.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <net/fou.h>
#include <net/ip.h>
#include <net/ip6_tunnel.h>
#include <net/ip6_checksum.h>
#include <net/protocol.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
static void fou6_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
struct flowi6 *fl6, u8 *protocol, __be16 sport)
{
struct udphdr *uh;
skb_push(skb, sizeof(struct udphdr));
skb_reset_transport_header(skb);
uh = udp_hdr(skb);
uh->dest = e->dport;
uh->source = sport;
uh->len = htons(skb->len);
udp6_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM6), skb,
&fl6->saddr, &fl6->daddr, skb->len);
*protocol = IPPROTO_UDP;
}
int fou6_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
u8 *protocol, struct flowi6 *fl6)
{
__be16 sport;
int err;
int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM6 ?
SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
err = __fou_build_header(skb, e, protocol, &sport, type);
if (err)
return err;
fou6_build_udp(skb, e, fl6, protocol, sport);
return 0;
}
EXPORT_SYMBOL(fou6_build_header);
int gue6_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
u8 *protocol, struct flowi6 *fl6)
{
__be16 sport;
int err;
int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM6 ?
SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
err = __gue_build_header(skb, e, protocol, &sport, type);
if (err)
return err;
fou6_build_udp(skb, e, fl6, protocol, sport);
return 0;
}
EXPORT_SYMBOL(gue6_build_header);
#if IS_ENABLED(CONFIG_IPV6_FOU_TUNNEL)
static const struct ip6_tnl_encap_ops fou_ip6tun_ops = {
.encap_hlen = fou_encap_hlen,
.build_header = fou6_build_header,
};
static const struct ip6_tnl_encap_ops gue_ip6tun_ops = {
.encap_hlen = gue_encap_hlen,
.build_header = gue6_build_header,
};
static int ip6_tnl_encap_add_fou_ops(void)
{
int ret;
ret = ip6_tnl_encap_add_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU);
if (ret < 0) {
pr_err("can't add fou6 ops\n");
return ret;
}
ret = ip6_tnl_encap_add_ops(&gue_ip6tun_ops, TUNNEL_ENCAP_GUE);
if (ret < 0) {
pr_err("can't add gue6 ops\n");
ip6_tnl_encap_del_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU);
return ret;
}
return 0;
}
static void ip6_tnl_encap_del_fou_ops(void)
{
ip6_tnl_encap_del_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU);
ip6_tnl_encap_del_ops(&gue_ip6tun_ops, TUNNEL_ENCAP_GUE);
}
#else
static int ip6_tnl_encap_add_fou_ops(void)
{
return 0;
}
static void ip6_tnl_encap_del_fou_ops(void)
{
}
#endif
static int __init fou6_init(void)
{
int ret;
ret = ip6_tnl_encap_add_fou_ops();
return ret;
}
static void __exit fou6_fini(void)
{
ip6_tnl_encap_del_fou_ops();
}
module_init(fou6_init);
module_exit(fou6_fini);
MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
MODULE_LICENSE("GPL");