111 lines
2.8 KiB
C
111 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/* Unstable XFRM Helpers for TC-BPF hook
|
|
*
|
|
* These are called from SCHED_CLS BPF programs. Note that it is
|
|
* allowed to break compatibility for these functions since the interface they
|
|
* are exposed through to BPF programs is explicitly unstable.
|
|
*/
|
|
|
|
#include <linux/bpf.h>
|
|
#include <linux/btf_ids.h>
|
|
|
|
#include <net/dst_metadata.h>
|
|
#include <net/xfrm.h>
|
|
|
|
/* bpf_xfrm_info - XFRM metadata information
|
|
*
|
|
* Members:
|
|
* @if_id - XFRM if_id:
|
|
* Transmit: if_id to be used in policy and state lookups
|
|
* Receive: if_id of the state matched for the incoming packet
|
|
* @link - Underlying device ifindex:
|
|
* Transmit: used as the underlying device in VRF routing
|
|
* Receive: the device on which the packet had been received
|
|
*/
|
|
struct bpf_xfrm_info {
|
|
u32 if_id;
|
|
int link;
|
|
};
|
|
|
|
__bpf_kfunc_start_defs();
|
|
|
|
/* bpf_skb_get_xfrm_info - Get XFRM metadata
|
|
*
|
|
* Parameters:
|
|
* @skb_ctx - Pointer to ctx (__sk_buff) in TC program
|
|
* Cannot be NULL
|
|
* @to - Pointer to memory to which the metadata will be copied
|
|
* Cannot be NULL
|
|
*/
|
|
__bpf_kfunc int bpf_skb_get_xfrm_info(struct __sk_buff *skb_ctx, struct bpf_xfrm_info *to)
|
|
{
|
|
struct sk_buff *skb = (struct sk_buff *)skb_ctx;
|
|
struct xfrm_md_info *info;
|
|
|
|
info = skb_xfrm_md_info(skb);
|
|
if (!info)
|
|
return -EINVAL;
|
|
|
|
to->if_id = info->if_id;
|
|
to->link = info->link;
|
|
return 0;
|
|
}
|
|
|
|
/* bpf_skb_get_xfrm_info - Set XFRM metadata
|
|
*
|
|
* Parameters:
|
|
* @skb_ctx - Pointer to ctx (__sk_buff) in TC program
|
|
* Cannot be NULL
|
|
* @from - Pointer to memory from which the metadata will be copied
|
|
* Cannot be NULL
|
|
*/
|
|
__bpf_kfunc int bpf_skb_set_xfrm_info(struct __sk_buff *skb_ctx, const struct bpf_xfrm_info *from)
|
|
{
|
|
struct sk_buff *skb = (struct sk_buff *)skb_ctx;
|
|
struct metadata_dst *md_dst;
|
|
struct xfrm_md_info *info;
|
|
|
|
if (unlikely(skb_metadata_dst(skb)))
|
|
return -EINVAL;
|
|
|
|
if (!xfrm_bpf_md_dst) {
|
|
struct metadata_dst __percpu *tmp;
|
|
|
|
tmp = metadata_dst_alloc_percpu(0, METADATA_XFRM, GFP_ATOMIC);
|
|
if (!tmp)
|
|
return -ENOMEM;
|
|
if (cmpxchg(&xfrm_bpf_md_dst, NULL, tmp))
|
|
metadata_dst_free_percpu(tmp);
|
|
}
|
|
md_dst = this_cpu_ptr(xfrm_bpf_md_dst);
|
|
|
|
info = &md_dst->u.xfrm_info;
|
|
|
|
info->if_id = from->if_id;
|
|
info->link = from->link;
|
|
skb_dst_force(skb);
|
|
info->dst_orig = skb_dst(skb);
|
|
|
|
dst_hold((struct dst_entry *)md_dst);
|
|
skb_dst_set(skb, (struct dst_entry *)md_dst);
|
|
return 0;
|
|
}
|
|
|
|
__bpf_kfunc_end_defs();
|
|
|
|
BTF_KFUNCS_START(xfrm_ifc_kfunc_set)
|
|
BTF_ID_FLAGS(func, bpf_skb_get_xfrm_info)
|
|
BTF_ID_FLAGS(func, bpf_skb_set_xfrm_info)
|
|
BTF_KFUNCS_END(xfrm_ifc_kfunc_set)
|
|
|
|
static const struct btf_kfunc_id_set xfrm_interface_kfunc_set = {
|
|
.owner = THIS_MODULE,
|
|
.set = &xfrm_ifc_kfunc_set,
|
|
};
|
|
|
|
int __init register_xfrm_interface_bpf(void)
|
|
{
|
|
return register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS,
|
|
&xfrm_interface_kfunc_set);
|
|
}
|