1/* Copyright (c) 2017 Facebook
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
6 */
7
8/* This program shows clang/llvm is able to generate code pattern
9 * like:
10 * _tcp_send_active_reset:
11 * 0: bf 16 00 00 00 00 00 00 r6 = r1
12 * ......
13 * 335: b7 01 00 00 0f 00 00 00 r1 = 15
14 * 336: 05 00 48 00 00 00 00 00 goto 72
15 *
16 * LBB0_3:
17 * 337: b7 01 00 00 01 00 00 00 r1 = 1
18 * 338: 63 1a d0 ff 00 00 00 00 *(u32 *)(r10 - 48) = r1
19 * 408: b7 01 00 00 03 00 00 00 r1 = 3
20 *
21 * LBB0_4:
22 * 409: 71 a2 fe ff 00 00 00 00 r2 = *(u8 *)(r10 - 2)
23 * 410: bf a7 00 00 00 00 00 00 r7 = r10
24 * 411: 07 07 00 00 b8 ff ff ff r7 += -72
25 * 412: bf 73 00 00 00 00 00 00 r3 = r7
26 * 413: 0f 13 00 00 00 00 00 00 r3 += r1
27 * 414: 73 23 2d 00 00 00 00 00 *(u8 *)(r3 + 45) = r2
28 *
29 * From the above code snippet, the code generated by the compiler
30 * is reasonable. The "r1" is assigned to different values in basic
31 * blocks "_tcp_send_active_reset" and "LBB0_3", and used in "LBB0_4".
32 * The verifier should be able to handle such code patterns.
33 */
34#include <string.h>
35#include <linux/bpf.h>
36#include <linux/ipv6.h>
37#include <linux/version.h>
38#include <sys/socket.h>
39#include <bpf/bpf_helpers.h>
40
41#define _(P) ({typeof(P) val = 0; bpf_probe_read_kernel(&val, sizeof(val), &P); val;})
42#define TCP_ESTATS_MAGIC 0xBAADBEEF
43
44/* This test case needs "sock" and "pt_regs" data structure.
45 * Recursively, "sock" needs "sock_common" and "inet_sock".
46 * However, this is a unit test case only for
47 * verifier purpose without bpf program execution.
48 * We can safely mock much simpler data structures, basically
49 * only taking the necessary fields from kernel headers.
50 */
51typedef __u32 __bitwise __portpair;
52typedef __u64 __bitwise __addrpair;
53
54struct sock_common {
55 unsigned short skc_family;
56 union {
57 __addrpair skc_addrpair;
58 struct {
59 __be32 skc_daddr;
60 __be32 skc_rcv_saddr;
61 };
62 };
63 union {
64 __portpair skc_portpair;
65 struct {
66 __be16 skc_dport;
67 __u16 skc_num;
68 };
69 };
70 struct in6_addr skc_v6_daddr;
71 struct in6_addr skc_v6_rcv_saddr;
72};
73
74struct sock {
75 struct sock_common __sk_common;
76#define sk_family __sk_common.skc_family
77#define sk_v6_daddr __sk_common.skc_v6_daddr
78#define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
79};
80
81struct inet_sock {
82 struct sock sk;
83#define inet_daddr sk.__sk_common.skc_daddr
84#define inet_dport sk.__sk_common.skc_dport
85 __be32 inet_saddr;
86 __be16 inet_sport;
87};
88
89struct pt_regs {
90 long di;
91};
92
93static inline struct inet_sock *inet_sk(const struct sock *sk)
94{
95 return (struct inet_sock *)sk;
96}
97
98/* Define various data structures for state recording.
99 * Some fields are not used due to test simplification.
100 */
101enum tcp_estats_addrtype {
102 TCP_ESTATS_ADDRTYPE_IPV4 = 1,
103 TCP_ESTATS_ADDRTYPE_IPV6 = 2
104};
105
106enum tcp_estats_event_type {
107 TCP_ESTATS_ESTABLISH,
108 TCP_ESTATS_PERIODIC,
109 TCP_ESTATS_TIMEOUT,
110 TCP_ESTATS_RETRANSMIT_TIMEOUT,
111 TCP_ESTATS_RETRANSMIT_OTHER,
112 TCP_ESTATS_SYN_RETRANSMIT,
113 TCP_ESTATS_SYNACK_RETRANSMIT,
114 TCP_ESTATS_TERM,
115 TCP_ESTATS_TX_RESET,
116 TCP_ESTATS_RX_RESET,
117 TCP_ESTATS_WRITE_TIMEOUT,
118 TCP_ESTATS_CONN_TIMEOUT,
119 TCP_ESTATS_ACK_LATENCY,
120 TCP_ESTATS_NEVENTS,
121};
122
123struct tcp_estats_event {
124 int pid;
125 int cpu;
126 unsigned long ts;
127 unsigned int magic;
128 enum tcp_estats_event_type event_type;
129};
130
131/* The below data structure is packed in order for
132 * llvm compiler to generate expected code.
133 */
134struct tcp_estats_conn_id {
135 unsigned int localaddressType;
136 struct {
137 unsigned char data[16];
138 } localaddress;
139 struct {
140 unsigned char data[16];
141 } remaddress;
142 unsigned short localport;
143 unsigned short remport;
144} __attribute__((__packed__));
145
146struct tcp_estats_basic_event {
147 struct tcp_estats_event event;
148 struct tcp_estats_conn_id conn_id;
149};
150
151struct {
152 __uint(type, BPF_MAP_TYPE_HASH);
153 __uint(max_entries, 1024);
154 __type(key, __u32);
155 __type(value, struct tcp_estats_basic_event);
156} ev_record_map SEC(".maps");
157
158struct dummy_tracepoint_args {
159 unsigned long long pad;
160 struct sock *sock;
161};
162
163static __always_inline void tcp_estats_ev_init(struct tcp_estats_event *event,
164 enum tcp_estats_event_type type)
165{
166 event->magic = TCP_ESTATS_MAGIC;
167 event->ts = bpf_ktime_get_ns();
168 event->event_type = type;
169}
170
171static __always_inline void unaligned_u32_set(unsigned char *to, __u8 *from)
172{
173 to[0] = _(from[0]);
174 to[1] = _(from[1]);
175 to[2] = _(from[2]);
176 to[3] = _(from[3]);
177}
178
179static __always_inline void conn_id_ipv4_init(struct tcp_estats_conn_id *conn_id,
180 __be32 *saddr, __be32 *daddr)
181{
182 conn_id->localaddressType = TCP_ESTATS_ADDRTYPE_IPV4;
183
184 unaligned_u32_set(to: conn_id->localaddress.data, from: (__u8 *)saddr);
185 unaligned_u32_set(to: conn_id->remaddress.data, from: (__u8 *)daddr);
186}
187
188static __always_inline void conn_id_ipv6_init(struct tcp_estats_conn_id *conn_id,
189 __be32 *saddr, __be32 *daddr)
190{
191 conn_id->localaddressType = TCP_ESTATS_ADDRTYPE_IPV6;
192
193 unaligned_u32_set(to: conn_id->localaddress.data, from: (__u8 *)saddr);
194 unaligned_u32_set(to: conn_id->localaddress.data + sizeof(__u32),
195 from: (__u8 *)(saddr + 1));
196 unaligned_u32_set(to: conn_id->localaddress.data + sizeof(__u32) * 2,
197 from: (__u8 *)(saddr + 2));
198 unaligned_u32_set(to: conn_id->localaddress.data + sizeof(__u32) * 3,
199 from: (__u8 *)(saddr + 3));
200
201 unaligned_u32_set(to: conn_id->remaddress.data,
202 from: (__u8 *)(daddr));
203 unaligned_u32_set(to: conn_id->remaddress.data + sizeof(__u32),
204 from: (__u8 *)(daddr + 1));
205 unaligned_u32_set(to: conn_id->remaddress.data + sizeof(__u32) * 2,
206 from: (__u8 *)(daddr + 2));
207 unaligned_u32_set(to: conn_id->remaddress.data + sizeof(__u32) * 3,
208 from: (__u8 *)(daddr + 3));
209}
210
211static __always_inline void tcp_estats_conn_id_init(struct tcp_estats_conn_id *conn_id,
212 struct sock *sk)
213{
214 conn_id->localport = _(inet_sk(sk)->inet_sport);
215 conn_id->remport = _(inet_sk(sk)->inet_dport);
216
217 if (_(sk->sk_family) == AF_INET6)
218 conn_id_ipv6_init(conn_id,
219 saddr: sk->sk_v6_rcv_saddr.s6_addr32,
220 daddr: sk->sk_v6_daddr.s6_addr32);
221 else
222 conn_id_ipv4_init(conn_id,
223 saddr: &inet_sk(sk)->inet_saddr,
224 daddr: &inet_sk(sk)->inet_daddr);
225}
226
227static __always_inline void tcp_estats_init(struct sock *sk,
228 struct tcp_estats_event *event,
229 struct tcp_estats_conn_id *conn_id,
230 enum tcp_estats_event_type type)
231{
232 tcp_estats_ev_init(event, type);
233 tcp_estats_conn_id_init(conn_id, sk);
234}
235
236static __always_inline void send_basic_event(struct sock *sk,
237 enum tcp_estats_event_type type)
238{
239 struct tcp_estats_basic_event ev;
240 __u32 key = bpf_get_prandom_u32();
241
242 memset(&ev, 0, sizeof(ev));
243 tcp_estats_init(sk, event: &ev.event, conn_id: &ev.conn_id, type);
244 bpf_map_update_elem(&ev_record_map, &key, &ev, BPF_ANY);
245}
246
247SEC("tp/dummy/tracepoint")
248int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
249{
250 if (!arg->sock)
251 return 0;
252
253 send_basic_event(sk: arg->sock, type: TCP_ESTATS_TX_RESET);
254 return 0;
255}
256
257char _license[] SEC("license") = "GPL";
258

source code of linux/tools/testing/selftests/bpf/progs/test_tcp_estats.c