linuxdebug/net/ipv4/xfrm4_tunnel.c

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2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/* xfrm4_tunnel.c: Generic IP tunnel transformer.
*
* Copyright (C) 2003 David S. Miller (davem@redhat.com)
*/
#define pr_fmt(fmt) "IPsec: " fmt
#include <linux/skbuff.h>
#include <linux/module.h>
#include <net/xfrm.h>
#include <net/protocol.h>
static int ipip_output(struct xfrm_state *x, struct sk_buff *skb)
{
skb_push(skb, -skb_network_offset(skb));
return 0;
}
static int ipip_xfrm_rcv(struct xfrm_state *x, struct sk_buff *skb)
{
return ip_hdr(skb)->protocol;
}
static int ipip_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
{
if (x->props.mode != XFRM_MODE_TUNNEL) {
NL_SET_ERR_MSG(extack, "IPv4 tunnel can only be used with tunnel mode");
return -EINVAL;
}
if (x->encap) {
NL_SET_ERR_MSG(extack, "IPv4 tunnel is not compatible with encapsulation");
return -EINVAL;
}
x->props.header_len = sizeof(struct iphdr);
return 0;
}
static void ipip_destroy(struct xfrm_state *x)
{
}
static const struct xfrm_type ipip_type = {
.owner = THIS_MODULE,
.proto = IPPROTO_IPIP,
.init_state = ipip_init_state,
.destructor = ipip_destroy,
.input = ipip_xfrm_rcv,
.output = ipip_output
};
static int xfrm_tunnel_rcv(struct sk_buff *skb)
{
return xfrm4_rcv_spi(skb, IPPROTO_IPIP, ip_hdr(skb)->saddr);
}
static int xfrm_tunnel_err(struct sk_buff *skb, u32 info)
{
return -ENOENT;
}
static struct xfrm_tunnel xfrm_tunnel_handler __read_mostly = {
.handler = xfrm_tunnel_rcv,
.err_handler = xfrm_tunnel_err,
.priority = 4,
};
#if IS_ENABLED(CONFIG_IPV6)
static struct xfrm_tunnel xfrm64_tunnel_handler __read_mostly = {
.handler = xfrm_tunnel_rcv,
.err_handler = xfrm_tunnel_err,
.priority = 3,
};
#endif
static int __init ipip_init(void)
{
if (xfrm_register_type(&ipip_type, AF_INET) < 0) {
pr_info("%s: can't add xfrm type\n", __func__);
return -EAGAIN;
}
if (xfrm4_tunnel_register(&xfrm_tunnel_handler, AF_INET)) {
pr_info("%s: can't add xfrm handler for AF_INET\n", __func__);
xfrm_unregister_type(&ipip_type, AF_INET);
return -EAGAIN;
}
#if IS_ENABLED(CONFIG_IPV6)
if (xfrm4_tunnel_register(&xfrm64_tunnel_handler, AF_INET6)) {
pr_info("%s: can't add xfrm handler for AF_INET6\n", __func__);
xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET);
xfrm_unregister_type(&ipip_type, AF_INET);
return -EAGAIN;
}
#endif
return 0;
}
static void __exit ipip_fini(void)
{
#if IS_ENABLED(CONFIG_IPV6)
if (xfrm4_tunnel_deregister(&xfrm64_tunnel_handler, AF_INET6))
pr_info("%s: can't remove xfrm handler for AF_INET6\n",
__func__);
#endif
if (xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET))
pr_info("%s: can't remove xfrm handler for AF_INET\n",
__func__);
xfrm_unregister_type(&ipip_type, AF_INET);
}
module_init(ipip_init);
module_exit(ipip_fini);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_IPIP);