Loading...
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 */
25struct 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 */
42__used noinline
43int bpf_skb_get_xfrm_info(struct __sk_buff *skb_ctx, struct bpf_xfrm_info *to)
44{
45 struct sk_buff *skb = (struct sk_buff *)skb_ctx;
46 struct xfrm_md_info *info;
47
48 info = skb_xfrm_md_info(skb);
49 if (!info)
50 return -EINVAL;
51
52 to->if_id = info->if_id;
53 to->link = info->link;
54 return 0;
55}
56
57/* bpf_skb_get_xfrm_info - Set XFRM metadata
58 *
59 * Parameters:
60 * @skb_ctx - Pointer to ctx (__sk_buff) in TC program
61 * Cannot be NULL
62 * @from - Pointer to memory from which the metadata will be copied
63 * Cannot be NULL
64 */
65__used noinline
66int bpf_skb_set_xfrm_info(struct __sk_buff *skb_ctx,
67 const struct bpf_xfrm_info *from)
68{
69 struct sk_buff *skb = (struct sk_buff *)skb_ctx;
70 struct metadata_dst *md_dst;
71 struct xfrm_md_info *info;
72
73 if (unlikely(skb_metadata_dst(skb)))
74 return -EINVAL;
75
76 if (!xfrm_bpf_md_dst) {
77 struct metadata_dst __percpu *tmp;
78
79 tmp = metadata_dst_alloc_percpu(0, METADATA_XFRM, GFP_ATOMIC);
80 if (!tmp)
81 return -ENOMEM;
82 if (cmpxchg(&xfrm_bpf_md_dst, NULL, tmp))
83 metadata_dst_free_percpu(tmp);
84 }
85 md_dst = this_cpu_ptr(xfrm_bpf_md_dst);
86
87 info = &md_dst->u.xfrm_info;
88
89 info->if_id = from->if_id;
90 info->link = from->link;
91 skb_dst_force(skb);
92 info->dst_orig = skb_dst(skb);
93
94 dst_hold((struct dst_entry *)md_dst);
95 skb_dst_set(skb, (struct dst_entry *)md_dst);
96 return 0;
97}
98
99__diag_pop()
100
101BTF_SET8_START(xfrm_ifc_kfunc_set)
102BTF_ID_FLAGS(func, bpf_skb_get_xfrm_info)
103BTF_ID_FLAGS(func, bpf_skb_set_xfrm_info)
104BTF_SET8_END(xfrm_ifc_kfunc_set)
105
106static const struct btf_kfunc_id_set xfrm_interface_kfunc_set = {
107 .owner = THIS_MODULE,
108 .set = &xfrm_ifc_kfunc_set,
109};
110
111int __init register_xfrm_interface_bpf(void)
112{
113 return register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS,
114 &xfrm_interface_kfunc_set);
115}
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 */
25struct bpf_xfrm_info {
26 u32 if_id;
27 int link;
28};
29
30__bpf_kfunc_start_defs();
31
32/* bpf_skb_get_xfrm_info - Get XFRM metadata
33 *
34 * Parameters:
35 * @skb_ctx - Pointer to ctx (__sk_buff) in TC program
36 * Cannot be NULL
37 * @to - Pointer to memory to which the metadata will be copied
38 * Cannot be NULL
39 */
40__bpf_kfunc int bpf_skb_get_xfrm_info(struct __sk_buff *skb_ctx, struct bpf_xfrm_info *to)
41{
42 struct sk_buff *skb = (struct sk_buff *)skb_ctx;
43 struct xfrm_md_info *info;
44
45 info = skb_xfrm_md_info(skb);
46 if (!info)
47 return -EINVAL;
48
49 to->if_id = info->if_id;
50 to->link = info->link;
51 return 0;
52}
53
54/* bpf_skb_get_xfrm_info - Set XFRM metadata
55 *
56 * Parameters:
57 * @skb_ctx - Pointer to ctx (__sk_buff) in TC program
58 * Cannot be NULL
59 * @from - Pointer to memory from which the metadata will be copied
60 * Cannot be NULL
61 */
62__bpf_kfunc int bpf_skb_set_xfrm_info(struct __sk_buff *skb_ctx, const struct bpf_xfrm_info *from)
63{
64 struct sk_buff *skb = (struct sk_buff *)skb_ctx;
65 struct metadata_dst *md_dst;
66 struct xfrm_md_info *info;
67
68 if (unlikely(skb_metadata_dst(skb)))
69 return -EINVAL;
70
71 if (!xfrm_bpf_md_dst) {
72 struct metadata_dst __percpu *tmp;
73
74 tmp = metadata_dst_alloc_percpu(0, METADATA_XFRM, GFP_ATOMIC);
75 if (!tmp)
76 return -ENOMEM;
77 if (cmpxchg(&xfrm_bpf_md_dst, NULL, tmp))
78 metadata_dst_free_percpu(tmp);
79 }
80 md_dst = this_cpu_ptr(xfrm_bpf_md_dst);
81
82 info = &md_dst->u.xfrm_info;
83
84 info->if_id = from->if_id;
85 info->link = from->link;
86 skb_dst_force(skb);
87 info->dst_orig = skb_dst(skb);
88
89 dst_hold((struct dst_entry *)md_dst);
90 skb_dst_set(skb, (struct dst_entry *)md_dst);
91 return 0;
92}
93
94__bpf_kfunc_end_defs();
95
96BTF_KFUNCS_START(xfrm_ifc_kfunc_set)
97BTF_ID_FLAGS(func, bpf_skb_get_xfrm_info)
98BTF_ID_FLAGS(func, bpf_skb_set_xfrm_info)
99BTF_KFUNCS_END(xfrm_ifc_kfunc_set)
100
101static const struct btf_kfunc_id_set xfrm_interface_kfunc_set = {
102 .owner = THIS_MODULE,
103 .set = &xfrm_ifc_kfunc_set,
104};
105
106int __init register_xfrm_interface_bpf(void)
107{
108 return register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS,
109 &xfrm_interface_kfunc_set);
110}