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