1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include "cgroup_helpers.h"
4 #include "network_helpers.h"
5
6 struct tcp_rtt_storage {
7 __u32 invoked;
8 __u32 dsack_dups;
9 __u32 delivered;
10 __u32 delivered_ce;
11 __u32 icsk_retransmits;
12 };
13
send_byte(int fd)14 static void send_byte(int fd)
15 {
16 char b = 0x55;
17
18 if (CHECK_FAIL(write(fd, &b, sizeof(b)) != 1))
19 perror("Failed to send single byte");
20 }
21
wait_for_ack(int fd,int retries)22 static int wait_for_ack(int fd, int retries)
23 {
24 struct tcp_info info;
25 socklen_t optlen;
26 int i, err;
27
28 for (i = 0; i < retries; i++) {
29 optlen = sizeof(info);
30 err = getsockopt(fd, SOL_TCP, TCP_INFO, &info, &optlen);
31 if (err < 0) {
32 log_err("Failed to lookup TCP stats");
33 return err;
34 }
35
36 if (info.tcpi_unacked == 0)
37 return 0;
38
39 usleep(10);
40 }
41
42 log_err("Did not receive ACK");
43 return -1;
44 }
45
verify_sk(int map_fd,int client_fd,const char * msg,__u32 invoked,__u32 dsack_dups,__u32 delivered,__u32 delivered_ce,__u32 icsk_retransmits)46 static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 invoked,
47 __u32 dsack_dups, __u32 delivered, __u32 delivered_ce,
48 __u32 icsk_retransmits)
49 {
50 int err = 0;
51 struct tcp_rtt_storage val;
52
53 if (CHECK_FAIL(bpf_map_lookup_elem(map_fd, &client_fd, &val) < 0)) {
54 perror("Failed to read socket storage");
55 return -1;
56 }
57
58 if (val.invoked != invoked) {
59 log_err("%s: unexpected bpf_tcp_sock.invoked %d != %d",
60 msg, val.invoked, invoked);
61 err++;
62 }
63
64 if (val.dsack_dups != dsack_dups) {
65 log_err("%s: unexpected bpf_tcp_sock.dsack_dups %d != %d",
66 msg, val.dsack_dups, dsack_dups);
67 err++;
68 }
69
70 if (val.delivered != delivered) {
71 log_err("%s: unexpected bpf_tcp_sock.delivered %d != %d",
72 msg, val.delivered, delivered);
73 err++;
74 }
75
76 if (val.delivered_ce != delivered_ce) {
77 log_err("%s: unexpected bpf_tcp_sock.delivered_ce %d != %d",
78 msg, val.delivered_ce, delivered_ce);
79 err++;
80 }
81
82 if (val.icsk_retransmits != icsk_retransmits) {
83 log_err("%s: unexpected bpf_tcp_sock.icsk_retransmits %d != %d",
84 msg, val.icsk_retransmits, icsk_retransmits);
85 err++;
86 }
87
88 return err;
89 }
90
91
run_test(int cgroup_fd,int server_fd)92 static int run_test(int cgroup_fd, int server_fd)
93 {
94 struct bpf_prog_load_attr attr = {
95 .prog_type = BPF_PROG_TYPE_SOCK_OPS,
96 .file = "./tcp_rtt.o",
97 .expected_attach_type = BPF_CGROUP_SOCK_OPS,
98 };
99 struct bpf_object *obj;
100 struct bpf_map *map;
101 int client_fd;
102 int prog_fd;
103 int map_fd;
104 int err;
105
106 err = bpf_prog_load_xattr(&attr, &obj, &prog_fd);
107 if (err) {
108 log_err("Failed to load BPF object");
109 return -1;
110 }
111
112 map = bpf_map__next(NULL, obj);
113 map_fd = bpf_map__fd(map);
114
115 err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_SOCK_OPS, 0);
116 if (err) {
117 log_err("Failed to attach BPF program");
118 goto close_bpf_object;
119 }
120
121 client_fd = connect_to_fd(server_fd, 0);
122 if (client_fd < 0) {
123 err = -1;
124 goto close_bpf_object;
125 }
126
127 err += verify_sk(map_fd, client_fd, "syn-ack",
128 /*invoked=*/1,
129 /*dsack_dups=*/0,
130 /*delivered=*/1,
131 /*delivered_ce=*/0,
132 /*icsk_retransmits=*/0);
133
134 send_byte(client_fd);
135 if (wait_for_ack(client_fd, 100) < 0) {
136 err = -1;
137 goto close_client_fd;
138 }
139
140
141 err += verify_sk(map_fd, client_fd, "first payload byte",
142 /*invoked=*/2,
143 /*dsack_dups=*/0,
144 /*delivered=*/2,
145 /*delivered_ce=*/0,
146 /*icsk_retransmits=*/0);
147
148 close_client_fd:
149 close(client_fd);
150
151 close_bpf_object:
152 bpf_object__close(obj);
153 return err;
154 }
155
test_tcp_rtt(void)156 void test_tcp_rtt(void)
157 {
158 int server_fd, cgroup_fd;
159
160 cgroup_fd = test__join_cgroup("/tcp_rtt");
161 if (CHECK_FAIL(cgroup_fd < 0))
162 return;
163
164 server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
165 if (CHECK_FAIL(server_fd < 0))
166 goto close_cgroup_fd;
167
168 CHECK_FAIL(run_test(cgroup_fd, server_fd));
169
170 close(server_fd);
171
172 close_cgroup_fd:
173 close(cgroup_fd);
174 }
175