1 // SPDX-License-Identifier: GPL-2.0-only 1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Unstable Fou Helpers for TC-BPF hook 2 /* Unstable Fou Helpers for TC-BPF hook
3 * 3 *
4 * These are called from SCHED_CLS BPF program 4 * These are called from SCHED_CLS BPF programs. Note that it is
5 * allowed to break compatibility for these fu 5 * allowed to break compatibility for these functions since the interface they
6 * are exposed through to BPF programs is expl 6 * are exposed through to BPF programs is explicitly unstable.
7 */ 7 */
8 8
9 #include <linux/bpf.h> 9 #include <linux/bpf.h>
10 #include <linux/btf_ids.h> 10 #include <linux/btf_ids.h>
11 11
12 #include <net/dst_metadata.h> 12 #include <net/dst_metadata.h>
13 #include <net/fou.h> 13 #include <net/fou.h>
14 14
15 struct bpf_fou_encap { 15 struct bpf_fou_encap {
16 __be16 sport; 16 __be16 sport;
17 __be16 dport; 17 __be16 dport;
18 }; 18 };
19 19
20 enum bpf_fou_encap_type { 20 enum bpf_fou_encap_type {
21 FOU_BPF_ENCAP_FOU, 21 FOU_BPF_ENCAP_FOU,
22 FOU_BPF_ENCAP_GUE, 22 FOU_BPF_ENCAP_GUE,
23 }; 23 };
24 24
25 __bpf_kfunc_start_defs(); 25 __bpf_kfunc_start_defs();
26 26
27 /* bpf_skb_set_fou_encap - Set FOU encap param 27 /* bpf_skb_set_fou_encap - Set FOU encap parameters
28 * 28 *
29 * This function allows for using GUE or FOU e 29 * This function allows for using GUE or FOU encapsulation together with an
30 * ipip device in collect-metadata mode. 30 * ipip device in collect-metadata mode.
31 * 31 *
32 * It is meant to be used in BPF tc-hooks and 32 * It is meant to be used in BPF tc-hooks and after a call to the
33 * bpf_skb_set_tunnel_key helper, responsible 33 * bpf_skb_set_tunnel_key helper, responsible for setting IP addresses.
34 * 34 *
35 * Parameters: 35 * Parameters:
36 * @skb_ctx Pointer to ctx (__sk_buff) in 36 * @skb_ctx Pointer to ctx (__sk_buff) in TC program. Cannot be NULL
37 * @encap Pointer to a `struct bpf_fou_e 37 * @encap Pointer to a `struct bpf_fou_encap` storing UDP src and
38 * dst ports. If sport is set to 38 * dst ports. If sport is set to 0 the kernel will auto-assign a
39 * port. This is similar to using 39 * port. This is similar to using `encap-sport auto`.
40 * Cannot be NULL 40 * Cannot be NULL
41 * @type Encapsulation type for the pac 41 * @type Encapsulation type for the packet. Their definitions are
42 * specified in `enum bpf_fou_enc 42 * specified in `enum bpf_fou_encap_type`
43 */ 43 */
44 __bpf_kfunc int bpf_skb_set_fou_encap(struct _ 44 __bpf_kfunc int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
45 struct b 45 struct bpf_fou_encap *encap, int type)
46 { 46 {
47 struct sk_buff *skb = (struct sk_buff 47 struct sk_buff *skb = (struct sk_buff *)skb_ctx;
48 struct ip_tunnel_info *info = skb_tunn 48 struct ip_tunnel_info *info = skb_tunnel_info(skb);
49 49
50 if (unlikely(!encap)) 50 if (unlikely(!encap))
51 return -EINVAL; 51 return -EINVAL;
52 52
53 if (unlikely(!info || !(info->mode & I 53 if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX)))
54 return -EINVAL; 54 return -EINVAL;
55 55
56 switch (type) { 56 switch (type) {
57 case FOU_BPF_ENCAP_FOU: 57 case FOU_BPF_ENCAP_FOU:
58 info->encap.type = TUNNEL_ENCA 58 info->encap.type = TUNNEL_ENCAP_FOU;
59 break; 59 break;
60 case FOU_BPF_ENCAP_GUE: 60 case FOU_BPF_ENCAP_GUE:
61 info->encap.type = TUNNEL_ENCA 61 info->encap.type = TUNNEL_ENCAP_GUE;
62 break; 62 break;
63 default: 63 default:
64 info->encap.type = TUNNEL_ENCA 64 info->encap.type = TUNNEL_ENCAP_NONE;
65 } 65 }
66 66
67 if (test_bit(IP_TUNNEL_CSUM_BIT, info- !! 67 if (info->key.tun_flags & TUNNEL_CSUM)
68 info->encap.flags |= TUNNEL_EN 68 info->encap.flags |= TUNNEL_ENCAP_FLAG_CSUM;
69 69
70 info->encap.sport = encap->sport; 70 info->encap.sport = encap->sport;
71 info->encap.dport = encap->dport; 71 info->encap.dport = encap->dport;
72 72
73 return 0; 73 return 0;
74 } 74 }
75 75
76 /* bpf_skb_get_fou_encap - Get FOU encap param 76 /* bpf_skb_get_fou_encap - Get FOU encap parameters
77 * 77 *
78 * This function allows for reading encap meta 78 * This function allows for reading encap metadata from a packet received
79 * on an ipip device in collect-metadata mode. 79 * on an ipip device in collect-metadata mode.
80 * 80 *
81 * Parameters: 81 * Parameters:
82 * @skb_ctx Pointer to ctx (__sk_buff) in 82 * @skb_ctx Pointer to ctx (__sk_buff) in TC program. Cannot be NULL
83 * @encap Pointer to a struct bpf_fou_en 83 * @encap Pointer to a struct bpf_fou_encap storing UDP source and
84 * destination port. Cannot be NU 84 * destination port. Cannot be NULL
85 */ 85 */
86 __bpf_kfunc int bpf_skb_get_fou_encap(struct _ 86 __bpf_kfunc int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
87 struct b 87 struct bpf_fou_encap *encap)
88 { 88 {
89 struct sk_buff *skb = (struct sk_buff 89 struct sk_buff *skb = (struct sk_buff *)skb_ctx;
90 struct ip_tunnel_info *info = skb_tunn 90 struct ip_tunnel_info *info = skb_tunnel_info(skb);
91 91
92 if (unlikely(!info)) 92 if (unlikely(!info))
93 return -EINVAL; 93 return -EINVAL;
94 94
95 encap->sport = info->encap.sport; 95 encap->sport = info->encap.sport;
96 encap->dport = info->encap.dport; 96 encap->dport = info->encap.dport;
97 97
98 return 0; 98 return 0;
99 } 99 }
100 100
101 __bpf_kfunc_end_defs(); 101 __bpf_kfunc_end_defs();
102 102
103 BTF_KFUNCS_START(fou_kfunc_set) !! 103 BTF_SET8_START(fou_kfunc_set)
104 BTF_ID_FLAGS(func, bpf_skb_set_fou_encap) 104 BTF_ID_FLAGS(func, bpf_skb_set_fou_encap)
105 BTF_ID_FLAGS(func, bpf_skb_get_fou_encap) 105 BTF_ID_FLAGS(func, bpf_skb_get_fou_encap)
106 BTF_KFUNCS_END(fou_kfunc_set) !! 106 BTF_SET8_END(fou_kfunc_set)
107 107
108 static const struct btf_kfunc_id_set fou_bpf_k 108 static const struct btf_kfunc_id_set fou_bpf_kfunc_set = {
109 .owner = THIS_MODULE, 109 .owner = THIS_MODULE,
110 .set = &fou_kfunc_set, 110 .set = &fou_kfunc_set,
111 }; 111 };
112 112
113 int register_fou_bpf(void) 113 int register_fou_bpf(void)
114 { 114 {
115 return register_btf_kfunc_id_set(BPF_P 115 return register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS,
116 &fou_ 116 &fou_bpf_kfunc_set);
117 } 117 }
118 118
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