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1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (c) 2020 Facebook */
3 
4 #ifndef _TEST_TCP_HDR_OPTIONS_H
5 #define _TEST_TCP_HDR_OPTIONS_H
6 
7 struct bpf_test_option {
8 	__u8 flags;
9 	__u8 max_delack_ms;
10 	__u8 rand;
11 } __attribute__((packed));
12 
13 enum {
14 	OPTION_RESEND,
15 	OPTION_MAX_DELACK_MS,
16 	OPTION_RAND,
17 	__NR_OPTION_FLAGS,
18 };
19 
20 #define OPTION_F_RESEND		(1 << OPTION_RESEND)
21 #define OPTION_F_MAX_DELACK_MS	(1 << OPTION_MAX_DELACK_MS)
22 #define OPTION_F_RAND		(1 << OPTION_RAND)
23 #define OPTION_MASK		((1 << __NR_OPTION_FLAGS) - 1)
24 
25 #define TEST_OPTION_FLAGS(flags, option) (1 & ((flags) >> (option)))
26 #define SET_OPTION_FLAGS(flags, option)	((flags) |= (1 << (option)))
27 
28 /* Store in bpf_sk_storage */
29 struct hdr_stg {
30 	bool active;
31 	bool resend_syn; /* active side only */
32 	bool syncookie;  /* passive side only */
33 	bool fastopen;	/* passive side only */
34 };
35 
36 struct linum_err {
37 	unsigned int linum;
38 	int err;
39 };
40 
41 #define TCPHDR_FIN 0x01
42 #define TCPHDR_SYN 0x02
43 #define TCPHDR_RST 0x04
44 #define TCPHDR_PSH 0x08
45 #define TCPHDR_ACK 0x10
46 #define TCPHDR_URG 0x20
47 #define TCPHDR_ECE 0x40
48 #define TCPHDR_CWR 0x80
49 #define TCPHDR_SYNACK (TCPHDR_SYN | TCPHDR_ACK)
50 
51 #define TCPOPT_EOL		0
52 #define TCPOPT_NOP		1
53 #define TCPOPT_WINDOW		3
54 #define TCPOPT_EXP		254
55 
56 #define TCP_BPF_EXPOPT_BASE_LEN 4
57 #define MAX_TCP_HDR_LEN		60
58 #define MAX_TCP_OPTION_SPACE	40
59 
60 #ifdef BPF_PROG_TEST_TCP_HDR_OPTIONS
61 
62 #define CG_OK	1
63 #define CG_ERR	0
64 
65 #ifndef SOL_TCP
66 #define SOL_TCP 6
67 #endif
68 
69 struct tcp_exprm_opt {
70 	__u8 kind;
71 	__u8 len;
72 	__u16 magic;
73 	union {
74 		__u8 data[4];
75 		__u32 data32;
76 	};
77 } __attribute__((packed));
78 
79 struct tcp_opt {
80 	__u8 kind;
81 	__u8 len;
82 	union {
83 		__u8 data[4];
84 		__u32 data32;
85 	};
86 } __attribute__((packed));
87 
88 struct {
89 	__uint(type, BPF_MAP_TYPE_HASH);
90 	__uint(max_entries, 2);
91 	__type(key, int);
92 	__type(value, struct linum_err);
93 } lport_linum_map SEC(".maps");
94 
tcp_hdrlen(const struct tcphdr * th)95 static inline unsigned int tcp_hdrlen(const struct tcphdr *th)
96 {
97 	return th->doff << 2;
98 }
99 
skops_tcp_flags(const struct bpf_sock_ops * skops)100 static inline __u8 skops_tcp_flags(const struct bpf_sock_ops *skops)
101 {
102 	return skops->skb_tcp_flags;
103 }
104 
clear_hdr_cb_flags(struct bpf_sock_ops * skops)105 static inline void clear_hdr_cb_flags(struct bpf_sock_ops *skops)
106 {
107 	bpf_sock_ops_cb_flags_set(skops,
108 				  skops->bpf_sock_ops_cb_flags &
109 				  ~(BPF_SOCK_OPS_PARSE_UNKNOWN_HDR_OPT_CB_FLAG |
110 				    BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG));
111 }
112 
set_hdr_cb_flags(struct bpf_sock_ops * skops,__u32 extra)113 static inline void set_hdr_cb_flags(struct bpf_sock_ops *skops, __u32 extra)
114 {
115 	bpf_sock_ops_cb_flags_set(skops,
116 				  skops->bpf_sock_ops_cb_flags |
117 				  BPF_SOCK_OPS_PARSE_UNKNOWN_HDR_OPT_CB_FLAG |
118 				  BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG |
119 				  extra);
120 }
121 static inline void
clear_parse_all_hdr_cb_flags(struct bpf_sock_ops * skops)122 clear_parse_all_hdr_cb_flags(struct bpf_sock_ops *skops)
123 {
124 	bpf_sock_ops_cb_flags_set(skops,
125 				  skops->bpf_sock_ops_cb_flags &
126 				  ~BPF_SOCK_OPS_PARSE_ALL_HDR_OPT_CB_FLAG);
127 }
128 
129 static inline void
set_parse_all_hdr_cb_flags(struct bpf_sock_ops * skops)130 set_parse_all_hdr_cb_flags(struct bpf_sock_ops *skops)
131 {
132 	bpf_sock_ops_cb_flags_set(skops,
133 				  skops->bpf_sock_ops_cb_flags |
134 				  BPF_SOCK_OPS_PARSE_ALL_HDR_OPT_CB_FLAG);
135 }
136 
137 #define RET_CG_ERR(__err) ({			\
138 	struct linum_err __linum_err;		\
139 	int __lport;				\
140 						\
141 	__linum_err.linum = __LINE__;		\
142 	__linum_err.err = __err;		\
143 	__lport = skops->local_port;		\
144 	bpf_map_update_elem(&lport_linum_map, &__lport, &__linum_err, BPF_NOEXIST); \
145 	clear_hdr_cb_flags(skops);					\
146 	clear_parse_all_hdr_cb_flags(skops);				\
147 	return CG_ERR;							\
148 })
149 
150 #endif /* BPF_PROG_TEST_TCP_HDR_OPTIONS */
151 
152 #endif /* _TEST_TCP_HDR_OPTIONS_H */
153