1 // SPDX-License-Identifier: GPL-2.0
2 #define _GNU_SOURCE
3 #include <test_progs.h>
4 #include "cgroup_helpers.h"
5 #include "network_helpers.h"
6 #include "tcp_rtt.skel.h"
7
8 struct tcp_rtt_storage {
9 __u32 invoked;
10 __u32 dsack_dups;
11 __u32 delivered;
12 __u32 delivered_ce;
13 __u32 icsk_retransmits;
14
15 __u32 mrtt_us; /* args[0] */
16 __u32 srtt; /* args[1] */
17 };
18
send_byte(int fd)19 static void send_byte(int fd)
20 {
21 char b = 0x55;
22
23 ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");
24 }
25
wait_for_ack(int fd,int retries)26 static int wait_for_ack(int fd, int retries)
27 {
28 struct tcp_info info;
29 socklen_t optlen;
30 int i, err;
31
32 for (i = 0; i < retries; i++) {
33 optlen = sizeof(info);
34 err = getsockopt(fd, SOL_TCP, TCP_INFO, &info, &optlen);
35 if (err < 0) {
36 log_err("Failed to lookup TCP stats");
37 return err;
38 }
39
40 if (info.tcpi_unacked == 0)
41 return 0;
42
43 usleep(10);
44 }
45
46 log_err("Did not receive ACK");
47 return -1;
48 }
49
verify_sk(int map_fd,int client_fd,const char * msg,__u32 invoked,__u32 dsack_dups,__u32 delivered,__u32 delivered_ce,__u32 icsk_retransmits)50 static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 invoked,
51 __u32 dsack_dups, __u32 delivered, __u32 delivered_ce,
52 __u32 icsk_retransmits)
53 {
54 int err = 0;
55 struct tcp_rtt_storage val;
56
57 if (!ASSERT_GE(bpf_map_lookup_elem(map_fd, &client_fd, &val), 0, "read socket storage"))
58 return -1;
59
60 if (val.invoked != invoked) {
61 log_err("%s: unexpected bpf_tcp_sock.invoked %d != %d",
62 msg, val.invoked, invoked);
63 err++;
64 }
65
66 if (val.dsack_dups != dsack_dups) {
67 log_err("%s: unexpected bpf_tcp_sock.dsack_dups %d != %d",
68 msg, val.dsack_dups, dsack_dups);
69 err++;
70 }
71
72 if (val.delivered != delivered) {
73 log_err("%s: unexpected bpf_tcp_sock.delivered %d != %d",
74 msg, val.delivered, delivered);
75 err++;
76 }
77
78 if (val.delivered_ce != delivered_ce) {
79 log_err("%s: unexpected bpf_tcp_sock.delivered_ce %d != %d",
80 msg, val.delivered_ce, delivered_ce);
81 err++;
82 }
83
84 if (val.icsk_retransmits != icsk_retransmits) {
85 log_err("%s: unexpected bpf_tcp_sock.icsk_retransmits %d != %d",
86 msg, val.icsk_retransmits, icsk_retransmits);
87 err++;
88 }
89
90 /* Precise values of mrtt and srtt are unavailable, just make sure they are nonzero */
91 if (val.mrtt_us == 0) {
92 log_err("%s: unexpected bpf_tcp_sock.args[0] (mrtt_us) %u == 0", msg, val.mrtt_us);
93 err++;
94 }
95
96 if (val.srtt == 0) {
97 log_err("%s: unexpected bpf_tcp_sock.args[1] (srtt) %u == 0", msg, val.srtt);
98 err++;
99 }
100
101 return err;
102 }
103
104
run_test(int cgroup_fd,int server_fd)105 static int run_test(int cgroup_fd, int server_fd)
106 {
107 struct tcp_rtt *skel;
108 int client_fd;
109 int prog_fd;
110 int map_fd;
111 int err;
112
113 skel = tcp_rtt__open_and_load();
114 if (!ASSERT_OK_PTR(skel, "skel_open_load"))
115 return -1;
116
117 map_fd = bpf_map__fd(skel->maps.socket_storage_map);
118 prog_fd = bpf_program__fd(skel->progs._sockops);
119
120 err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_SOCK_OPS, 0);
121 if (err) {
122 log_err("Failed to attach BPF program");
123 goto close_bpf_object;
124 }
125
126 client_fd = connect_to_fd(server_fd, 0);
127 if (client_fd < 0) {
128 err = -1;
129 goto close_bpf_object;
130 }
131
132 err += verify_sk(map_fd, client_fd, "syn-ack",
133 /*invoked=*/1,
134 /*dsack_dups=*/0,
135 /*delivered=*/1,
136 /*delivered_ce=*/0,
137 /*icsk_retransmits=*/0);
138
139 send_byte(client_fd);
140 if (wait_for_ack(client_fd, 100) < 0) {
141 err = -1;
142 goto close_client_fd;
143 }
144
145
146 err += verify_sk(map_fd, client_fd, "first payload byte",
147 /*invoked=*/2,
148 /*dsack_dups=*/0,
149 /*delivered=*/2,
150 /*delivered_ce=*/0,
151 /*icsk_retransmits=*/0);
152
153 close_client_fd:
154 close(client_fd);
155
156 close_bpf_object:
157 tcp_rtt__destroy(skel);
158 return err;
159 }
160
test_tcp_rtt(void)161 void test_tcp_rtt(void)
162 {
163 int server_fd, cgroup_fd;
164
165 cgroup_fd = test__join_cgroup("/tcp_rtt");
166 if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup /tcp_rtt"))
167 return;
168
169 server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
170 if (!ASSERT_GE(server_fd, 0, "start_server"))
171 goto close_cgroup_fd;
172
173 ASSERT_OK(run_test(cgroup_fd, server_fd), "run_test");
174
175 close(server_fd);
176
177 close_cgroup_fd:
178 close(cgroup_fd);
179 }
180