1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include "cgroup_helpers.h"
5 struct tcp_rtt_storage {
10 __u32 icsk_retransmits;
13 static void send_byte(int fd)
17 if (CHECK_FAIL(write(fd, &b, sizeof(b)) != 1))
18 perror("Failed to send single byte");
21 static int wait_for_ack(int fd, int retries)
27 for (i = 0; i < retries; i++) {
28 optlen = sizeof(info);
29 err = getsockopt(fd, SOL_TCP, TCP_INFO, &info, &optlen);
31 log_err("Failed to lookup TCP stats");
35 if (info.tcpi_unacked == 0)
41 log_err("Did not receive ACK");
45 static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 invoked,
46 __u32 dsack_dups, __u32 delivered, __u32 delivered_ce,
47 __u32 icsk_retransmits)
50 struct tcp_rtt_storage val;
52 if (CHECK_FAIL(bpf_map_lookup_elem(map_fd, &client_fd, &val) < 0)) {
53 perror("Failed to read socket storage");
57 if (val.invoked != invoked) {
58 log_err("%s: unexpected bpf_tcp_sock.invoked %d != %d",
59 msg, val.invoked, invoked);
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);
69 if (val.delivered != delivered) {
70 log_err("%s: unexpected bpf_tcp_sock.delivered %d != %d",
71 msg, val.delivered, delivered);
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);
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);
90 static int connect_to_server(int server_fd)
92 struct sockaddr_storage addr;
93 socklen_t len = sizeof(addr);
96 fd = socket(AF_INET, SOCK_STREAM, 0);
98 log_err("Failed to create client socket");
102 if (getsockname(server_fd, (struct sockaddr *)&addr, &len)) {
103 log_err("Failed to get server addr");
107 if (connect(fd, (const struct sockaddr *)&addr, len) < 0) {
108 log_err("Fail to connect to server");
119 static int run_test(int cgroup_fd, int server_fd)
121 struct bpf_prog_load_attr attr = {
122 .prog_type = BPF_PROG_TYPE_SOCK_OPS,
123 .file = "./tcp_rtt.o",
124 .expected_attach_type = BPF_CGROUP_SOCK_OPS,
126 struct bpf_object *obj;
133 err = bpf_prog_load_xattr(&attr, &obj, &prog_fd);
135 log_err("Failed to load BPF object");
139 map = bpf_map__next(NULL, obj);
140 map_fd = bpf_map__fd(map);
142 err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_SOCK_OPS, 0);
144 log_err("Failed to attach BPF program");
145 goto close_bpf_object;
148 client_fd = connect_to_server(server_fd);
151 goto close_bpf_object;
154 err += verify_sk(map_fd, client_fd, "syn-ack",
159 /*icsk_retransmits=*/0);
161 send_byte(client_fd);
162 if (wait_for_ack(client_fd, 100) < 0) {
164 goto close_client_fd;
168 err += verify_sk(map_fd, client_fd, "first payload byte",
173 /*icsk_retransmits=*/0);
179 bpf_object__close(obj);
183 static int start_server(void)
185 struct sockaddr_in addr = {
186 .sin_family = AF_INET,
187 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
191 fd = socket(AF_INET, SOCK_STREAM, 0);
193 log_err("Failed to create server socket");
197 if (bind(fd, (const struct sockaddr *)&addr, sizeof(addr)) < 0) {
198 log_err("Failed to bind socket");
206 static void *server_thread(void *arg)
208 struct sockaddr_storage addr;
209 socklen_t len = sizeof(addr);
210 int fd = *(int *)arg;
213 if (CHECK_FAIL(listen(fd, 1)) < 0) {
214 perror("Failed to listed on socket");
218 client_fd = accept(fd, (struct sockaddr *)&addr, &len);
219 if (CHECK_FAIL(client_fd < 0)) {
220 perror("Failed to accept client");
224 /* Wait for the next connection (that never arrives)
225 * to keep this thread alive to prevent calling
226 * close() on client_fd.
228 if (CHECK_FAIL(accept(fd, (struct sockaddr *)&addr, &len) >= 0)) {
229 perror("Unexpected success in second accept");
238 void test_tcp_rtt(void)
240 int server_fd, cgroup_fd;
243 cgroup_fd = test__join_cgroup("/tcp_rtt");
244 if (CHECK_FAIL(cgroup_fd < 0))
247 server_fd = start_server();
248 if (CHECK_FAIL(server_fd < 0))
249 goto close_cgroup_fd;
251 pthread_create(&tid, NULL, server_thread, (void *)&server_fd);
252 CHECK_FAIL(run_test(cgroup_fd, server_fd));