mirror of
				https://github.com/torvalds/linux.git
				synced 2025-11-04 10:40:15 +02:00 
			
		
		
		
	Now that we have the __bpf_kfunc tag, we should use add it to all existing kfuncs to ensure that they'll never be elided in LTO builds. Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20230201173016.342758-4-void@manifault.com
		
			
				
	
	
		
			112 lines
		
	
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			112 lines
		
	
	
	
		
			2.9 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;
 | 
						|
};
 | 
						|
 | 
						|
__diag_push();
 | 
						|
__diag_ignore_all("-Wmissing-prototypes",
 | 
						|
		  "Global functions as their definitions will be in xfrm_interface BTF");
 | 
						|
 | 
						|
/* 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;
 | 
						|
}
 | 
						|
 | 
						|
__diag_pop()
 | 
						|
 | 
						|
BTF_SET8_START(xfrm_ifc_kfunc_set)
 | 
						|
BTF_ID_FLAGS(func, bpf_skb_get_xfrm_info)
 | 
						|
BTF_ID_FLAGS(func, bpf_skb_set_xfrm_info)
 | 
						|
BTF_SET8_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);
 | 
						|
}
 |