tools/testing/selftests/bpf/test_sockopt_multi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include <error.h>
   4 #include <errno.h>
   5 #include <stdio.h>
   6 #include <unistd.h>
   7 #include <sys/types.h>
   8 #include <sys/socket.h>
   9 #include <netinet/in.h>
  10
  11 #include <linux/filter.h>
  12 #include <bpf/bpf.h>
  13 #include <bpf/libbpf.h>
  14
  15 #include "bpf_rlimit.h"
  16 #include "bpf_util.h"
  17 #include "cgroup_helpers.h"
  18
  19 static int prog_attach(struct bpf_object *obj, int cgroup_fd, const char *title)
  20 {
  21         enum bpf_attach_type attach_type;
  22         enum bpf_prog_type prog_type;
  23         struct bpf_program *prog;
  24         int err;
  25
  26         err = libbpf_prog_type_by_name(title, &prog_type, &attach_type);
  27         if (err) {
  28                 log_err("Failed to deduct types for %s BPF program", title);
  29                 return -1;
  30         }
  31
  32         prog = bpf_object__find_program_by_title(obj, title);
  33         if (!prog) {
  34                 log_err("Failed to find %s BPF program", title);
  35                 return -1;
  36         }
  37
  38         err = bpf_prog_attach(bpf_program__fd(prog), cgroup_fd,
  39                               attach_type, BPF_F_ALLOW_MULTI);
  40         if (err) {
  41                 log_err("Failed to attach %s BPF program", title);
  42                 return -1;
  43         }
  44
  45         return 0;
  46 }
  47
  48 static int prog_detach(struct bpf_object *obj, int cgroup_fd, const char *title)
  49 {
  50         enum bpf_attach_type attach_type;
  51         enum bpf_prog_type prog_type;
  52         struct bpf_program *prog;
  53         int err;
  54
  55         err = libbpf_prog_type_by_name(title, &prog_type, &attach_type);
  56         if (err)
  57                 return -1;
  58
  59         prog = bpf_object__find_program_by_title(obj, title);
  60         if (!prog)
  61                 return -1;
  62
  63         err = bpf_prog_detach2(bpf_program__fd(prog), cgroup_fd,
  64                                attach_type);
  65         if (err)
  66                 return -1;
  67
  68         return 0;
  69 }
  70
  71 static int run_getsockopt_test(struct bpf_object *obj, int cg_parent,
  72                                int cg_child, int sock_fd)
  73 {
  74         socklen_t optlen;
  75         __u8 buf;
  76         int err;
  77
  78         /* Set IP_TOS to the expected value (0x80). */
  79
  80         buf = 0x80;
  81         err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
  82         if (err < 0) {
  83                 log_err("Failed to call setsockopt(IP_TOS)");
  84                 goto detach;
  85         }
  86
  87         buf = 0x00;
  88         optlen = 1;
  89         err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
  90         if (err) {
  91                 log_err("Failed to call getsockopt(IP_TOS)");
  92                 goto detach;
  93         }
  94
  95         if (buf != 0x80) {
  96                 log_err("Unexpected getsockopt 0x%x != 0x80 without BPF", buf);
  97                 err = -1;
  98                 goto detach;
  99         }
 100
 101         /* Attach child program and make sure it returns new value:
 102          * - kernel:      -> 0x80
 103          * - child:  0x80 -> 0x90
 104          */
 105
 106         err = prog_attach(obj, cg_child, "cgroup/getsockopt/child");
 107         if (err)
 108                 goto detach;
 109
 110         buf = 0x00;
 111         optlen = 1;
 112         err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
 113         if (err) {
 114                 log_err("Failed to call getsockopt(IP_TOS)");
 115                 goto detach;
 116         }
 117
 118         if (buf != 0x90) {
 119                 log_err("Unexpected getsockopt 0x%x != 0x90", buf);
 120                 err = -1;
 121                 goto detach;
 122         }
 123
 124         /* Attach parent program and make sure it returns new value:
 125          * - kernel:      -> 0x80
 126          * - child:  0x80 -> 0x90
 127          * - parent: 0x90 -> 0xA0
 128          */
 129
 130         err = prog_attach(obj, cg_parent, "cgroup/getsockopt/parent");
 131         if (err)
 132                 goto detach;
 133
 134         buf = 0x00;
 135         optlen = 1;
 136         err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
 137         if (err) {
 138                 log_err("Failed to call getsockopt(IP_TOS)");
 139                 goto detach;
 140         }
 141
 142         if (buf != 0xA0) {
 143                 log_err("Unexpected getsockopt 0x%x != 0xA0", buf);
 144                 err = -1;
 145                 goto detach;
 146         }
 147
 148         /* Setting unexpected initial sockopt should return EPERM:
 149          * - kernel: -> 0x40
 150          * - child:  unexpected 0x40, EPERM
 151          * - parent: unexpected 0x40, EPERM
 152          */
 153
 154         buf = 0x40;
 155         if (setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1) < 0) {
 156                 log_err("Failed to call setsockopt(IP_TOS)");
 157                 goto detach;
 158         }
 159
 160         buf = 0x00;
 161         optlen = 1;
 162         err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
 163         if (!err) {
 164                 log_err("Unexpected success from getsockopt(IP_TOS)");
 165                 goto detach;
 166         }
 167
 168         /* Detach child program and make sure we still get EPERM:
 169          * - kernel: -> 0x40
 170          * - parent: unexpected 0x40, EPERM
 171          */
 172
 173         err = prog_detach(obj, cg_child, "cgroup/getsockopt/child");
 174         if (err) {
 175                 log_err("Failed to detach child program");
 176                 goto detach;
 177         }
 178
 179         buf = 0x00;
 180         optlen = 1;
 181         err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
 182         if (!err) {
 183                 log_err("Unexpected success from getsockopt(IP_TOS)");
 184                 goto detach;
 185         }
 186
 187         /* Set initial value to the one the parent program expects:
 188          * - kernel:      -> 0x90
 189          * - parent: 0x90 -> 0xA0
 190          */
 191
 192         buf = 0x90;
 193         err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
 194         if (err < 0) {
 195                 log_err("Failed to call setsockopt(IP_TOS)");
 196                 goto detach;
 197         }
 198
 199         buf = 0x00;
 200         optlen = 1;
 201         err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
 202         if (err) {
 203                 log_err("Failed to call getsockopt(IP_TOS)");
 204                 goto detach;
 205         }
 206
 207         if (buf != 0xA0) {
 208                 log_err("Unexpected getsockopt 0x%x != 0xA0", buf);
 209                 err = -1;
 210                 goto detach;
 211         }
 212
 213 detach:
 214         prog_detach(obj, cg_child, "cgroup/getsockopt/child");
 215         prog_detach(obj, cg_parent, "cgroup/getsockopt/parent");
 216
 217         return err;
 218 }
 219
 220 static int run_setsockopt_test(struct bpf_object *obj, int cg_parent,
 221                                int cg_child, int sock_fd)
 222 {
 223         socklen_t optlen;
 224         __u8 buf;
 225         int err;
 226
 227         /* Set IP_TOS to the expected value (0x80). */
 228
 229         buf = 0x80;
 230         err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
 231         if (err < 0) {
 232                 log_err("Failed to call setsockopt(IP_TOS)");
 233                 goto detach;
 234         }
 235
 236         buf = 0x00;
 237         optlen = 1;
 238         err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
 239         if (err) {
 240                 log_err("Failed to call getsockopt(IP_TOS)");
 241                 goto detach;
 242         }
 243
 244         if (buf != 0x80) {
 245                 log_err("Unexpected getsockopt 0x%x != 0x80 without BPF", buf);
 246                 err = -1;
 247                 goto detach;
 248         }
 249
 250         /* Attach child program and make sure it adds 0x10. */
 251
 252         err = prog_attach(obj, cg_child, "cgroup/setsockopt");
 253         if (err)
 254                 goto detach;
 255
 256         buf = 0x80;
 257         err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
 258         if (err < 0) {
 259                 log_err("Failed to call setsockopt(IP_TOS)");
 260                 goto detach;
 261         }
 262
 263         buf = 0x00;
 264         optlen = 1;
 265         err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
 266         if (err) {
 267                 log_err("Failed to call getsockopt(IP_TOS)");
 268                 goto detach;
 269         }
 270
 271         if (buf != 0x80 + 0x10) {
 272                 log_err("Unexpected getsockopt 0x%x != 0x80 + 0x10", buf);
 273                 err = -1;
 274                 goto detach;
 275         }
 276
 277         /* Attach parent program and make sure it adds another 0x10. */
 278
 279         err = prog_attach(obj, cg_parent, "cgroup/setsockopt");
 280         if (err)
 281                 goto detach;
 282
 283         buf = 0x80;
 284         err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
 285         if (err < 0) {
 286                 log_err("Failed to call setsockopt(IP_TOS)");
 287                 goto detach;
 288         }
 289
 290         buf = 0x00;
 291         optlen = 1;
 292         err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
 293         if (err) {
 294                 log_err("Failed to call getsockopt(IP_TOS)");
 295                 goto detach;
 296         }
 297
 298         if (buf != 0x80 + 2 * 0x10) {
 299                 log_err("Unexpected getsockopt 0x%x != 0x80 + 2 * 0x10", buf);
 300                 err = -1;
 301                 goto detach;
 302         }
 303
 304 detach:
 305         prog_detach(obj, cg_child, "cgroup/setsockopt");
 306         prog_detach(obj, cg_parent, "cgroup/setsockopt");
 307
 308         return err;
 309 }
 310
 311 int main(int argc, char **argv)
 312 {
 313         struct bpf_prog_load_attr attr = {
 314                 .file = "./sockopt_multi.o",
 315         };
 316         int cg_parent = -1, cg_child = -1;
 317         struct bpf_object *obj = NULL;
 318         int sock_fd = -1;
 319         int err = -1;
 320         int ignored;
 321
 322         if (setup_cgroup_environment()) {
 323                 log_err("Failed to setup cgroup environment\n");
 324                 goto out;
 325         }
 326
 327         cg_parent = create_and_get_cgroup("/parent");
 328         if (cg_parent < 0) {
 329                 log_err("Failed to create cgroup /parent\n");
 330                 goto out;
 331         }
 332
 333         cg_child = create_and_get_cgroup("/parent/child");
 334         if (cg_child < 0) {
 335                 log_err("Failed to create cgroup /parent/child\n");
 336                 goto out;
 337         }
 338
 339         if (join_cgroup("/parent/child")) {
 340                 log_err("Failed to join cgroup /parent/child\n");
 341                 goto out;
 342         }
 343
 344         err = bpf_prog_load_xattr(&attr, &obj, &ignored);
 345         if (err) {
 346                 log_err("Failed to load BPF object");
 347                 goto out;
 348         }
 349
 350         sock_fd = socket(AF_INET, SOCK_STREAM, 0);
 351         if (sock_fd < 0) {
 352                 log_err("Failed to create socket");
 353                 goto out;
 354         }
 355
 356         if (run_getsockopt_test(obj, cg_parent, cg_child, sock_fd))
 357                 err = -1;
 358         printf("test_sockopt_multi: getsockopt %s\n",
 359                err ? "FAILED" : "PASSED");
 360
 361         if (run_setsockopt_test(obj, cg_parent, cg_child, sock_fd))
 362                 err = -1;
 363         printf("test_sockopt_multi: setsockopt %s\n",
 364                err ? "FAILED" : "PASSED");
 365
 366 out:
 367         close(sock_fd);
 368         bpf_object__close(obj);
 369         close(cg_child);
 370         close(cg_parent);
 371
 372         printf("test_sockopt_multi: %s\n", err ? "FAILED" : "PASSED");
 373         return err ? EXIT_FAILURE : EXIT_SUCCESS;
 374 }