1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include "cgroup_helpers.h"
4 #include "network_helpers.h"
5 #include "tcp_rtt.skel.h"
6
7 struct tcp_rtt_storage {
8 __u32 invoked;
9 __u32 dsack_dups;
10 __u32 delivered;
11 __u32 delivered_ce;
12 __u32 icsk_retransmits;
13 };
14
send_byte(int fd)15 static void send_byte(int fd)
16 {
17 char b = 0x55;
18
19 ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "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 (!ASSERT_GE(bpf_map_lookup_elem(map_fd, &client_fd, &val), 0, "read socket storage"))
54 return -1;
55
56 if (val.invoked != invoked) {
57 log_err("%s: unexpected bpf_tcp_sock.invoked %d != %d",
58 msg, val.invoked, invoked);
59 err++;
60 }
61
62 if (val.dsack_dups != dsack_dups) {
63 log_err("%s: unexpected bpf_tcp_sock.dsack_dups %d != %d",
64 msg, val.dsack_dups, dsack_dups);
65 err++;
66 }
67
68 if (val.delivered != delivered) {
69 log_err("%s: unexpected bpf_tcp_sock.delivered %d != %d",
70 msg, val.delivered, delivered);
71 err++;
72 }
73
74 if (val.delivered_ce != delivered_ce) {
75 log_err("%s: unexpected bpf_tcp_sock.delivered_ce %d != %d",
76 msg, val.delivered_ce, delivered_ce);
77 err++;
78 }
79
80 if (val.icsk_retransmits != icsk_retransmits) {
81 log_err("%s: unexpected bpf_tcp_sock.icsk_retransmits %d != %d",
82 msg, val.icsk_retransmits, icsk_retransmits);
83 err++;
84 }
85
86 return err;
87 }
88
89
run_test(int cgroup_fd,int server_fd)90 static int run_test(int cgroup_fd, int server_fd)
91 {
92 struct tcp_rtt *skel;
93 int client_fd;
94 int prog_fd;
95 int map_fd;
96 int err;
97
98 skel = tcp_rtt__open_and_load();
99 if (!ASSERT_OK_PTR(skel, "skel_open_load"))
100 return -1;
101
102 map_fd = bpf_map__fd(skel->maps.socket_storage_map);
103 prog_fd = bpf_program__fd(skel->progs._sockops);
104
105 err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_SOCK_OPS, 0);
106 if (err) {
107 log_err("Failed to attach BPF program");
108 goto close_bpf_object;
109 }
110
111 client_fd = connect_to_fd(server_fd, 0);
112 if (client_fd < 0) {
113 err = -1;
114 goto close_bpf_object;
115 }
116
117 err += verify_sk(map_fd, client_fd, "syn-ack",
118 /*invoked=*/1,
119 /*dsack_dups=*/0,
120 /*delivered=*/1,
121 /*delivered_ce=*/0,
122 /*icsk_retransmits=*/0);
123
124 send_byte(client_fd);
125 if (wait_for_ack(client_fd, 100) < 0) {
126 err = -1;
127 goto close_client_fd;
128 }
129
130
131 err += verify_sk(map_fd, client_fd, "first payload byte",
132 /*invoked=*/2,
133 /*dsack_dups=*/0,
134 /*delivered=*/2,
135 /*delivered_ce=*/0,
136 /*icsk_retransmits=*/0);
137
138 close_client_fd:
139 close(client_fd);
140
141 close_bpf_object:
142 tcp_rtt__destroy(skel);
143 return err;
144 }
145
test_tcp_rtt(void)146 void test_tcp_rtt(void)
147 {
148 int server_fd, cgroup_fd;
149
150 cgroup_fd = test__join_cgroup("/tcp_rtt");
151 if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup /tcp_rtt"))
152 return;
153
154 server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
155 if (!ASSERT_GE(server_fd, 0, "start_server"))
156 goto close_cgroup_fd;
157
158 ASSERT_OK(run_test(cgroup_fd, server_fd), "run_test");
159
160 close(server_fd);
161
162 close_cgroup_fd:
163 close(cgroup_fd);
164 }
165