[linux-block.git] / net / xfrm / xfrm_interface_bpf.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);
}
Commit	Line	Data
94151f5a EB	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/* Unstable XFRM Helpers for TC-BPF hook
	3	*
	4	* These are called from SCHED_CLS BPF programs. Note that it is
	5	* allowed to break compatibility for these functions since the interface they
	6	* are exposed through to BPF programs is explicitly unstable.
	7	*/
	8
	9	#include <linux/bpf.h>
	10	#include <linux/btf_ids.h>
	11
	12	#include <net/dst_metadata.h>
	13	#include <net/xfrm.h>
	14
	15	/* bpf_xfrm_info - XFRM metadata information
	16	*
	17	* Members:
	18	* @if_id - XFRM if_id:
	19	* Transmit: if_id to be used in policy and state lookups
	20	* Receive: if_id of the state matched for the incoming packet
	21	* @link - Underlying device ifindex:
	22	* Transmit: used as the underlying device in VRF routing
	23	* Receive: the device on which the packet had been received
	24	*/
	25	struct bpf_xfrm_info {
	26	u32 if_id;
	27	int link;
	28	};
	29
	30	__diag_push();
	31	__diag_ignore_all("-Wmissing-prototypes",
	32	"Global functions as their definitions will be in xfrm_interface BTF");
	33
	34	/* bpf_skb_get_xfrm_info - Get XFRM metadata
	35	*
	36	* Parameters:
	37	* @skb_ctx - Pointer to ctx (__sk_buff) in TC program
	38	* Cannot be NULL
	39	* @to - Pointer to memory to which the metadata will be copied
	40	* Cannot be NULL
	41	*/
400031e0	42	__bpf_kfunc int bpf_skb_get_xfrm_info(struct __sk_buff skb_ctx, struct bpf_xfrm_info to)
94151f5a EB	43	{
	44	struct sk_buff skb = (struct sk_buff )skb_ctx;
	45	struct xfrm_md_info *info;
	46
	47	info = skb_xfrm_md_info(skb);
	48	if (!info)
	49	return -EINVAL;
	50
	51	to->if_id = info->if_id;
	52	to->link = info->link;
	53	return 0;
	54	}
	55
	56	/* bpf_skb_get_xfrm_info - Set XFRM metadata
	57	*
	58	* Parameters:
	59	* @skb_ctx - Pointer to ctx (__sk_buff) in TC program
	60	* Cannot be NULL
	61	* @from - Pointer to memory from which the metadata will be copied
	62	* Cannot be NULL
	63	*/
400031e0	64	__bpf_kfunc int bpf_skb_set_xfrm_info(struct __sk_buff skb_ctx, const struct bpf_xfrm_info from)
94151f5a EB	65	{
	66	struct sk_buff skb = (struct sk_buff )skb_ctx;
	67	struct metadata_dst *md_dst;
	68	struct xfrm_md_info *info;
	69
	70	if (unlikely(skb_metadata_dst(skb)))
	71	return -EINVAL;
	72
	73	if (!xfrm_bpf_md_dst) {
	74	struct metadata_dst __percpu *tmp;
	75
	76	tmp = metadata_dst_alloc_percpu(0, METADATA_XFRM, GFP_ATOMIC);
	77	if (!tmp)
	78	return -ENOMEM;
	79	if (cmpxchg(&xfrm_bpf_md_dst, NULL, tmp))
	80	metadata_dst_free_percpu(tmp);
	81	}
	82	md_dst = this_cpu_ptr(xfrm_bpf_md_dst);
	83
	84	info = &md_dst->u.xfrm_info;
	85
	86	info->if_id = from->if_id;
	87	info->link = from->link;
	88	skb_dst_force(skb);
	89	info->dst_orig = skb_dst(skb);
	90
	91	dst_hold((struct dst_entry *)md_dst);
	92	skb_dst_set(skb, (struct dst_entry *)md_dst);
	93	return 0;
	94	}
	95
	96	__diag_pop()
	97
	98	BTF_SET8_START(xfrm_ifc_kfunc_set)
	99	BTF_ID_FLAGS(func, bpf_skb_get_xfrm_info)
	100	BTF_ID_FLAGS(func, bpf_skb_set_xfrm_info)
	101	BTF_SET8_END(xfrm_ifc_kfunc_set)
	102
	103	static const struct btf_kfunc_id_set xfrm_interface_kfunc_set = {
	104	.owner = THIS_MODULE,
	105	.set = &xfrm_ifc_kfunc_set,
	106	};
	107
	108	int __init register_xfrm_interface_bpf(void)
	109	{
	110	return register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS,
	111	&xfrm_interface_kfunc_set);
	112	}