1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2020 Facebook */ 3 4 #define _GNU_SOURCE 5 #include <netinet/in.h> 6 #include <arpa/inet.h> 7 #include <unistd.h> 8 #include <stdlib.h> 9 #include <string.h> 10 #include <errno.h> 11 #include <sched.h> 12 #include <linux/compiler.h> 13 #include <bpf/libbpf.h> 14 15 #include "network_helpers.h" 16 #include "test_progs.h" 17 #include "test_btf_skc_cls_ingress.skel.h" 18 19 static struct test_btf_skc_cls_ingress *skel; 20 static struct sockaddr_in6 srv_sa6; 21 static __u32 duration; 22 23 #define PROG_PIN_FILE "/sys/fs/bpf/btf_skc_cls_ingress" 24 25 static int write_sysctl(const char *sysctl, const char *value) 26 { 27 int fd, err, len; 28 29 fd = open(sysctl, O_WRONLY); 30 if (CHECK(fd == -1, "open sysctl", "open(%s): %s (%d)\n", 31 sysctl, strerror(errno), errno)) 32 return -1; 33 34 len = strlen(value); 35 err = write(fd, value, len); 36 close(fd); 37 if (CHECK(err != len, "write sysctl", 38 "write(%s, %s, %d): err:%d %s (%d)\n", 39 sysctl, value, len, err, strerror(errno), errno)) 40 return -1; 41 42 return 0; 43 } 44 45 static int prepare_netns(void) 46 { 47 if (CHECK(unshare(CLONE_NEWNET), "create netns", 48 "unshare(CLONE_NEWNET): %s (%d)", 49 strerror(errno), errno)) 50 return -1; 51 52 if (CHECK(system("ip link set dev lo up"), 53 "ip link set dev lo up", "failed\n")) 54 return -1; 55 56 if (CHECK(system("tc qdisc add dev lo clsact"), 57 "tc qdisc add dev lo clsact", "failed\n")) 58 return -1; 59 60 if (CHECK(system("tc filter add dev lo ingress bpf direct-action object-pinned " PROG_PIN_FILE), 61 "install tc cls-prog at ingress", "failed\n")) 62 return -1; 63 64 /* Ensure 20 bytes options (i.e. in total 40 bytes tcp header) for the 65 * bpf_tcp_gen_syncookie() helper. 66 */ 67 if (write_sysctl("/proc/sys/net/ipv4/tcp_window_scaling", "1") || 68 write_sysctl("/proc/sys/net/ipv4/tcp_timestamps", "1") || 69 write_sysctl("/proc/sys/net/ipv4/tcp_sack", "1")) 70 return -1; 71 72 return 0; 73 } 74 75 static void reset_test(void) 76 { 77 memset(&skel->bss->srv_sa6, 0, sizeof(skel->bss->srv_sa6)); 78 skel->bss->listen_tp_sport = 0; 79 skel->bss->req_sk_sport = 0; 80 skel->bss->recv_cookie = 0; 81 skel->bss->gen_cookie = 0; 82 skel->bss->linum = 0; 83 } 84 85 static void print_err_line(void) 86 { 87 if (skel->bss->linum) 88 printf("bpf prog error at line %u\n", skel->bss->linum); 89 } 90 91 static void test_conn(void) 92 { 93 int listen_fd = -1, cli_fd = -1, err; 94 socklen_t addrlen = sizeof(srv_sa6); 95 int srv_port; 96 97 if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "1")) 98 return; 99 100 listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0); 101 if (CHECK_FAIL(listen_fd == -1)) 102 return; 103 104 err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen); 105 if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err, 106 errno)) 107 goto done; 108 memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6)); 109 srv_port = ntohs(srv_sa6.sin6_port); 110 111 cli_fd = connect_to_fd(listen_fd, 0); 112 if (CHECK_FAIL(cli_fd == -1)) 113 goto done; 114 115 if (CHECK(skel->bss->listen_tp_sport != srv_port || 116 skel->bss->req_sk_sport != srv_port, 117 "Unexpected sk src port", 118 "listen_tp_sport:%u req_sk_sport:%u expected:%u\n", 119 skel->bss->listen_tp_sport, skel->bss->req_sk_sport, 120 srv_port)) 121 goto done; 122 123 if (CHECK(skel->bss->gen_cookie || skel->bss->recv_cookie, 124 "Unexpected syncookie states", 125 "gen_cookie:%u recv_cookie:%u\n", 126 skel->bss->gen_cookie, skel->bss->recv_cookie)) 127 goto done; 128 129 CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n", 130 skel->bss->linum); 131 132 done: 133 if (listen_fd != -1) 134 close(listen_fd); 135 if (cli_fd != -1) 136 close(cli_fd); 137 } 138 139 static void test_syncookie(void) 140 { 141 int listen_fd = -1, cli_fd = -1, err; 142 socklen_t addrlen = sizeof(srv_sa6); 143 int srv_port; 144 145 /* Enforce syncookie mode */ 146 if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "2")) 147 return; 148 149 listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0); 150 if (CHECK_FAIL(listen_fd == -1)) 151 return; 152 153 err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen); 154 if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err, 155 errno)) 156 goto done; 157 memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6)); 158 srv_port = ntohs(srv_sa6.sin6_port); 159 160 cli_fd = connect_to_fd(listen_fd, 0); 161 if (CHECK_FAIL(cli_fd == -1)) 162 goto done; 163 164 if (CHECK(skel->bss->listen_tp_sport != srv_port, 165 "Unexpected tp src port", 166 "listen_tp_sport:%u expected:%u\n", 167 skel->bss->listen_tp_sport, srv_port)) 168 goto done; 169 170 if (CHECK(skel->bss->req_sk_sport, 171 "Unexpected req_sk src port", 172 "req_sk_sport:%u expected:0\n", 173 skel->bss->req_sk_sport)) 174 goto done; 175 176 if (CHECK(!skel->bss->gen_cookie || 177 skel->bss->gen_cookie != skel->bss->recv_cookie, 178 "Unexpected syncookie states", 179 "gen_cookie:%u recv_cookie:%u\n", 180 skel->bss->gen_cookie, skel->bss->recv_cookie)) 181 goto done; 182 183 CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n", 184 skel->bss->linum); 185 186 done: 187 if (listen_fd != -1) 188 close(listen_fd); 189 if (cli_fd != -1) 190 close(cli_fd); 191 } 192 193 struct test { 194 const char *desc; 195 void (*run)(void); 196 }; 197 198 #define DEF_TEST(name) { #name, test_##name } 199 static struct test tests[] = { 200 DEF_TEST(conn), 201 DEF_TEST(syncookie), 202 }; 203 204 void test_btf_skc_cls_ingress(void) 205 { 206 int i, err; 207 208 skel = test_btf_skc_cls_ingress__open_and_load(); 209 if (CHECK(!skel, "test_btf_skc_cls_ingress__open_and_load", "failed\n")) 210 return; 211 212 err = bpf_program__pin(skel->progs.cls_ingress, PROG_PIN_FILE); 213 if (CHECK(err, "bpf_program__pin", 214 "cannot pin bpf prog to %s. err:%d\n", PROG_PIN_FILE, err)) { 215 test_btf_skc_cls_ingress__destroy(skel); 216 return; 217 } 218 219 for (i = 0; i < ARRAY_SIZE(tests); i++) { 220 if (!test__start_subtest(tests[i].desc)) 221 continue; 222 223 if (prepare_netns()) 224 break; 225 226 tests[i].run(); 227 228 print_err_line(); 229 reset_test(); 230 } 231 232 bpf_program__unpin(skel->progs.cls_ingress, PROG_PIN_FILE); 233 test_btf_skc_cls_ingress__destroy(skel); 234 } 235