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 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 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 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 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 } 155 156 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