diff options
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/tcp_rtt.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/tcp_rtt.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/tcp_rtt.c b/tools/testing/selftests/bpf/prog_tests/tcp_rtt.c new file mode 100644 index 000000000000..fdc0b3614a9e --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/tcp_rtt.c @@ -0,0 +1,256 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include "cgroup_helpers.h" + +struct tcp_rtt_storage { + __u32 invoked; + __u32 dsack_dups; + __u32 delivered; + __u32 delivered_ce; + __u32 icsk_retransmits; +}; + +static void send_byte(int fd) +{ + char b = 0x55; + + if (CHECK_FAIL(write(fd, &b, sizeof(b)) != 1)) + perror("Failed to send single byte"); +} + +static int wait_for_ack(int fd, int retries) +{ + struct tcp_info info; + socklen_t optlen; + int i, err; + + for (i = 0; i < retries; i++) { + optlen = sizeof(info); + err = getsockopt(fd, SOL_TCP, TCP_INFO, &info, &optlen); + if (err < 0) { + log_err("Failed to lookup TCP stats"); + return err; + } + + if (info.tcpi_unacked == 0) + return 0; + + usleep(10); + } + + log_err("Did not receive ACK"); + return -1; +} + +static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 invoked, + __u32 dsack_dups, __u32 delivered, __u32 delivered_ce, + __u32 icsk_retransmits) +{ + int err = 0; + struct tcp_rtt_storage val; + + if (CHECK_FAIL(bpf_map_lookup_elem(map_fd, &client_fd, &val) < 0)) { + perror("Failed to read socket storage"); + return -1; + } + + if (val.invoked != invoked) { + log_err("%s: unexpected bpf_tcp_sock.invoked %d != %d", + msg, val.invoked, invoked); + err++; + } + + if (val.dsack_dups != dsack_dups) { + log_err("%s: unexpected bpf_tcp_sock.dsack_dups %d != %d", + msg, val.dsack_dups, dsack_dups); + err++; + } + + if (val.delivered != delivered) { + log_err("%s: unexpected bpf_tcp_sock.delivered %d != %d", + msg, val.delivered, delivered); + err++; + } + + if (val.delivered_ce != delivered_ce) { + log_err("%s: unexpected bpf_tcp_sock.delivered_ce %d != %d", + msg, val.delivered_ce, delivered_ce); + err++; + } + + if (val.icsk_retransmits != icsk_retransmits) { + log_err("%s: unexpected bpf_tcp_sock.icsk_retransmits %d != %d", + msg, val.icsk_retransmits, icsk_retransmits); + err++; + } + + return err; +} + +static int connect_to_server(int server_fd) +{ + struct sockaddr_storage addr; + socklen_t len = sizeof(addr); + int fd; + + fd = socket(AF_INET, SOCK_STREAM, 0); + if (fd < 0) { + log_err("Failed to create client socket"); + return -1; + } + + if (getsockname(server_fd, (struct sockaddr *)&addr, &len)) { + log_err("Failed to get server addr"); + goto out; + } + + if (connect(fd, (const struct sockaddr *)&addr, len) < 0) { + log_err("Fail to connect to server"); + goto out; + } + + return fd; + +out: + close(fd); + return -1; +} + +static int run_test(int cgroup_fd, int server_fd) +{ + struct bpf_prog_load_attr attr = { + .prog_type = BPF_PROG_TYPE_SOCK_OPS, + .file = "./tcp_rtt.o", + .expected_attach_type = BPF_CGROUP_SOCK_OPS, + }; + struct bpf_object *obj; + struct bpf_map *map; + int client_fd; + int prog_fd; + int map_fd; + int err; + + err = bpf_prog_load_xattr(&attr, &obj, &prog_fd); + if (err) { + log_err("Failed to load BPF object"); + return -1; + } + + map = bpf_map__next(NULL, obj); + map_fd = bpf_map__fd(map); + + err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_SOCK_OPS, 0); + if (err) { + log_err("Failed to attach BPF program"); + goto close_bpf_object; + } + + client_fd = connect_to_server(server_fd); + if (client_fd < 0) { + err = -1; + goto close_bpf_object; + } + + err += verify_sk(map_fd, client_fd, "syn-ack", + /*invoked=*/1, + /*dsack_dups=*/0, + /*delivered=*/1, + /*delivered_ce=*/0, + /*icsk_retransmits=*/0); + + send_byte(client_fd); + if (wait_for_ack(client_fd, 100) < 0) { + err = -1; + goto close_client_fd; + } + + + err += verify_sk(map_fd, client_fd, "first payload byte", + /*invoked=*/2, + /*dsack_dups=*/0, + /*delivered=*/2, + /*delivered_ce=*/0, + /*icsk_retransmits=*/0); + +close_client_fd: + close(client_fd); + +close_bpf_object: + bpf_object__close(obj); + return err; +} + +static int start_server(void) +{ + struct sockaddr_in addr = { + .sin_family = AF_INET, + .sin_addr.s_addr = htonl(INADDR_LOOPBACK), + }; + int fd; + + fd = socket(AF_INET, SOCK_STREAM, 0); + if (fd < 0) { + log_err("Failed to create server socket"); + return -1; + } + + if (bind(fd, (const struct sockaddr *)&addr, sizeof(addr)) < 0) { + log_err("Failed to bind socket"); + close(fd); + return -1; + } + + return fd; +} + +static void *server_thread(void *arg) +{ + struct sockaddr_storage addr; + socklen_t len = sizeof(addr); + int fd = *(int *)arg; + int client_fd; + + if (CHECK_FAIL(listen(fd, 1)) < 0) { + perror("Failed to listed on socket"); + return NULL; + } + + client_fd = accept(fd, (struct sockaddr *)&addr, &len); + if (CHECK_FAIL(client_fd < 0)) { + perror("Failed to accept client"); + return NULL; + } + + /* Wait for the next connection (that never arrives) + * to keep this thread alive to prevent calling + * close() on client_fd. + */ + if (CHECK_FAIL(accept(fd, (struct sockaddr *)&addr, &len) >= 0)) { + perror("Unexpected success in second accept"); + return NULL; + } + + close(client_fd); + + return NULL; +} + +void test_tcp_rtt(void) +{ + int server_fd, cgroup_fd; + pthread_t tid; + + cgroup_fd = test__join_cgroup("/tcp_rtt"); + if (CHECK_FAIL(cgroup_fd < 0)) + return; + + server_fd = start_server(); + if (CHECK_FAIL(server_fd < 0)) + goto close_cgroup_fd; + + pthread_create(&tid, NULL, server_thread, (void *)&server_fd); + CHECK_FAIL(run_test(cgroup_fd, server_fd)); + close(server_fd); +close_cgroup_fd: + close(cgroup_fd); +} |