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, srv_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 srv_fd = accept(listen_fd, NULL, NULL); 116 if (CHECK_FAIL(srv_fd == -1)) 117 goto done; 118 119 if (CHECK(skel->bss->listen_tp_sport != srv_port || 120 skel->bss->req_sk_sport != srv_port, 121 "Unexpected sk src port", 122 "listen_tp_sport:%u req_sk_sport:%u expected:%u\n", 123 skel->bss->listen_tp_sport, skel->bss->req_sk_sport, 124 srv_port)) 125 goto done; 126 127 if (CHECK(skel->bss->gen_cookie || skel->bss->recv_cookie, 128 "Unexpected syncookie states", 129 "gen_cookie:%u recv_cookie:%u\n", 130 skel->bss->gen_cookie, skel->bss->recv_cookie)) 131 goto done; 132 133 CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n", 134 skel->bss->linum); 135 136 done: 137 if (listen_fd != -1) 138 close(listen_fd); 139 if (cli_fd != -1) 140 close(cli_fd); 141 if (srv_fd != -1) 142 close(srv_fd); 143 } 144 145 static void test_syncookie(void) 146 { 147 int listen_fd = -1, cli_fd = -1, srv_fd = -1, err; 148 socklen_t addrlen = sizeof(srv_sa6); 149 int srv_port; 150 151 /* Enforce syncookie mode */ 152 if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "2")) 153 return; 154 155 listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0); 156 if (CHECK_FAIL(listen_fd == -1)) 157 return; 158 159 err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen); 160 if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err, 161 errno)) 162 goto done; 163 memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6)); 164 srv_port = ntohs(srv_sa6.sin6_port); 165 166 cli_fd = connect_to_fd(listen_fd, 0); 167 if (CHECK_FAIL(cli_fd == -1)) 168 goto done; 169 170 srv_fd = accept(listen_fd, NULL, NULL); 171 if (CHECK_FAIL(srv_fd == -1)) 172 goto done; 173 174 if (CHECK(skel->bss->listen_tp_sport != srv_port, 175 "Unexpected tp src port", 176 "listen_tp_sport:%u expected:%u\n", 177 skel->bss->listen_tp_sport, srv_port)) 178 goto done; 179 180 if (CHECK(skel->bss->req_sk_sport, 181 "Unexpected req_sk src port", 182 "req_sk_sport:%u expected:0\n", 183 skel->bss->req_sk_sport)) 184 goto done; 185 186 if (CHECK(!skel->bss->gen_cookie || 187 skel->bss->gen_cookie != skel->bss->recv_cookie, 188 "Unexpected syncookie states", 189 "gen_cookie:%u recv_cookie:%u\n", 190 skel->bss->gen_cookie, skel->bss->recv_cookie)) 191 goto done; 192 193 CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n", 194 skel->bss->linum); 195 196 done: 197 if (listen_fd != -1) 198 close(listen_fd); 199 if (cli_fd != -1) 200 close(cli_fd); 201 if (srv_fd != -1) 202 close(srv_fd); 203 } 204 205 struct test { 206 const char *desc; 207 void (*run)(void); 208 }; 209 210 #define DEF_TEST(name) { #name, test_##name } 211 static struct test tests[] = { 212 DEF_TEST(conn), 213 DEF_TEST(syncookie), 214 }; 215 216 void test_btf_skc_cls_ingress(void) 217 { 218 int i, err; 219 220 skel = test_btf_skc_cls_ingress__open_and_load(); 221 if (CHECK(!skel, "test_btf_skc_cls_ingress__open_and_load", "failed\n")) 222 return; 223 224 err = bpf_program__pin(skel->progs.cls_ingress, PROG_PIN_FILE); 225 if (CHECK(err, "bpf_program__pin", 226 "cannot pin bpf prog to %s. err:%d\n", PROG_PIN_FILE, err)) { 227 test_btf_skc_cls_ingress__destroy(skel); 228 return; 229 } 230 231 for (i = 0; i < ARRAY_SIZE(tests); i++) { 232 if (!test__start_subtest(tests[i].desc)) 233 continue; 234 235 if (prepare_netns()) 236 break; 237 238 tests[i].run(); 239 240 print_err_line(); 241 reset_test(); 242 } 243 244 bpf_program__unpin(skel->progs.cls_ingress, PROG_PIN_FILE); 245 test_btf_skc_cls_ingress__destroy(skel); 246 } 247