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 __diag_push();
>> 26 __diag_ignore_all("-Wmissing-prototypes",
>> 27 "Global functions as their definitions will be in BTF");
26 28
27 /* bpf_skb_set_fou_encap - Set FOU encap param 29 /* bpf_skb_set_fou_encap - Set FOU encap parameters
28 * 30 *
29 * This function allows for using GUE or FOU e 31 * This function allows for using GUE or FOU encapsulation together with an
30 * ipip device in collect-metadata mode. 32 * ipip device in collect-metadata mode.
31 * 33 *
32 * It is meant to be used in BPF tc-hooks and 34 * It is meant to be used in BPF tc-hooks and after a call to the
33 * bpf_skb_set_tunnel_key helper, responsible 35 * bpf_skb_set_tunnel_key helper, responsible for setting IP addresses.
34 * 36 *
35 * Parameters: 37 * Parameters:
36 * @skb_ctx Pointer to ctx (__sk_buff) in 38 * @skb_ctx Pointer to ctx (__sk_buff) in TC program. Cannot be NULL
37 * @encap Pointer to a `struct bpf_fou_e 39 * @encap Pointer to a `struct bpf_fou_encap` storing UDP src and
38 * dst ports. If sport is set to 40 * dst ports. If sport is set to 0 the kernel will auto-assign a
39 * port. This is similar to using 41 * port. This is similar to using `encap-sport auto`.
40 * Cannot be NULL 42 * Cannot be NULL
41 * @type Encapsulation type for the pac 43 * @type Encapsulation type for the packet. Their definitions are
42 * specified in `enum bpf_fou_enc 44 * specified in `enum bpf_fou_encap_type`
43 */ 45 */
44 __bpf_kfunc int bpf_skb_set_fou_encap(struct _ 46 __bpf_kfunc int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
45 struct b 47 struct bpf_fou_encap *encap, int type)
46 { 48 {
47 struct sk_buff *skb = (struct sk_buff 49 struct sk_buff *skb = (struct sk_buff *)skb_ctx;
48 struct ip_tunnel_info *info = skb_tunn 50 struct ip_tunnel_info *info = skb_tunnel_info(skb);
49 51
50 if (unlikely(!encap)) 52 if (unlikely(!encap))
51 return -EINVAL; 53 return -EINVAL;
52 54
53 if (unlikely(!info || !(info->mode & I 55 if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX)))
54 return -EINVAL; 56 return -EINVAL;
55 57
56 switch (type) { 58 switch (type) {
57 case FOU_BPF_ENCAP_FOU: 59 case FOU_BPF_ENCAP_FOU:
58 info->encap.type = TUNNEL_ENCA 60 info->encap.type = TUNNEL_ENCAP_FOU;
59 break; 61 break;
60 case FOU_BPF_ENCAP_GUE: 62 case FOU_BPF_ENCAP_GUE:
61 info->encap.type = TUNNEL_ENCA 63 info->encap.type = TUNNEL_ENCAP_GUE;
62 break; 64 break;
63 default: 65 default:
64 info->encap.type = TUNNEL_ENCA 66 info->encap.type = TUNNEL_ENCAP_NONE;
65 } 67 }
66 68
67 if (test_bit(IP_TUNNEL_CSUM_BIT, info- !! 69 if (info->key.tun_flags & TUNNEL_CSUM)
68 info->encap.flags |= TUNNEL_EN 70 info->encap.flags |= TUNNEL_ENCAP_FLAG_CSUM;
69 71
70 info->encap.sport = encap->sport; 72 info->encap.sport = encap->sport;
71 info->encap.dport = encap->dport; 73 info->encap.dport = encap->dport;
72 74
73 return 0; 75 return 0;
74 } 76 }
75 77
76 /* bpf_skb_get_fou_encap - Get FOU encap param 78 /* bpf_skb_get_fou_encap - Get FOU encap parameters
77 * 79 *
78 * This function allows for reading encap meta 80 * This function allows for reading encap metadata from a packet received
79 * on an ipip device in collect-metadata mode. 81 * on an ipip device in collect-metadata mode.
80 * 82 *
81 * Parameters: 83 * Parameters:
82 * @skb_ctx Pointer to ctx (__sk_buff) in 84 * @skb_ctx Pointer to ctx (__sk_buff) in TC program. Cannot be NULL
83 * @encap Pointer to a struct bpf_fou_en 85 * @encap Pointer to a struct bpf_fou_encap storing UDP source and
84 * destination port. Cannot be NU 86 * destination port. Cannot be NULL
85 */ 87 */
86 __bpf_kfunc int bpf_skb_get_fou_encap(struct _ 88 __bpf_kfunc int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
87 struct b 89 struct bpf_fou_encap *encap)
88 { 90 {
89 struct sk_buff *skb = (struct sk_buff 91 struct sk_buff *skb = (struct sk_buff *)skb_ctx;
90 struct ip_tunnel_info *info = skb_tunn 92 struct ip_tunnel_info *info = skb_tunnel_info(skb);
91 93
92 if (unlikely(!info)) 94 if (unlikely(!info))
93 return -EINVAL; 95 return -EINVAL;
94 96
95 encap->sport = info->encap.sport; 97 encap->sport = info->encap.sport;
96 encap->dport = info->encap.dport; 98 encap->dport = info->encap.dport;
97 99
98 return 0; 100 return 0;
99 } 101 }
100 102
101 __bpf_kfunc_end_defs(); !! 103 __diag_pop()
102 104
103 BTF_KFUNCS_START(fou_kfunc_set) !! 105 BTF_SET8_START(fou_kfunc_set)
104 BTF_ID_FLAGS(func, bpf_skb_set_fou_encap) 106 BTF_ID_FLAGS(func, bpf_skb_set_fou_encap)
105 BTF_ID_FLAGS(func, bpf_skb_get_fou_encap) 107 BTF_ID_FLAGS(func, bpf_skb_get_fou_encap)
106 BTF_KFUNCS_END(fou_kfunc_set) !! 108 BTF_SET8_END(fou_kfunc_set)
107 109
108 static const struct btf_kfunc_id_set fou_bpf_k 110 static const struct btf_kfunc_id_set fou_bpf_kfunc_set = {
109 .owner = THIS_MODULE, 111 .owner = THIS_MODULE,
110 .set = &fou_kfunc_set, 112 .set = &fou_kfunc_set,
111 }; 113 };
112 114
113 int register_fou_bpf(void) 115 int register_fou_bpf(void)
114 { 116 {
115 return register_btf_kfunc_id_set(BPF_P 117 return register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS,
116 &fou_ 118 &fou_bpf_kfunc_set);
117 } 119 }
118 120
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