tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c

   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 }