1 /* 2 * Copyright (C) 2017-2018 Netronome Systems, Inc. 3 * 4 * This software is licensed under the GNU General License Version 2, 5 * June 1991 as shown in the file COPYING in the top-level directory of this 6 * source tree. 7 * 8 * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" 9 * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, 10 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 11 * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE 12 * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME 13 * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 14 */ 15 16 #include <linux/bpf.h> 17 #include <linux/bpf_verifier.h> 18 #include <linux/bug.h> 19 #include <linux/kdev_t.h> 20 #include <linux/list.h> 21 #include <linux/lockdep.h> 22 #include <linux/netdevice.h> 23 #include <linux/printk.h> 24 #include <linux/proc_ns.h> 25 #include <linux/rhashtable.h> 26 #include <linux/rtnetlink.h> 27 #include <linux/rwsem.h> 28 29 /* Protects offdevs, members of bpf_offload_netdev and offload members 30 * of all progs. 31 * RTNL lock cannot be taken when holding this lock. 32 */ 33 static DECLARE_RWSEM(bpf_devs_lock); 34 35 struct bpf_offload_dev { 36 const struct bpf_prog_offload_ops *ops; 37 struct list_head netdevs; 38 void *priv; 39 }; 40 41 struct bpf_offload_netdev { 42 struct rhash_head l; 43 struct net_device *netdev; 44 struct bpf_offload_dev *offdev; 45 struct list_head progs; 46 struct list_head maps; 47 struct list_head offdev_netdevs; 48 }; 49 50 static const struct rhashtable_params offdevs_params = { 51 .nelem_hint = 4, 52 .key_len = sizeof(struct net_device *), 53 .key_offset = offsetof(struct bpf_offload_netdev, netdev), 54 .head_offset = offsetof(struct bpf_offload_netdev, l), 55 .automatic_shrinking = true, 56 }; 57 58 static struct rhashtable offdevs; 59 60 static int bpf_dev_offload_check(struct net_device *netdev) 61 { 62 if (!netdev) 63 return -EINVAL; 64 if (!netdev->netdev_ops->ndo_bpf) 65 return -EOPNOTSUPP; 66 return 0; 67 } 68 69 static struct bpf_offload_netdev * 70 bpf_offload_find_netdev(struct net_device *netdev) 71 { 72 lockdep_assert_held(&bpf_devs_lock); 73 74 return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params); 75 } 76 77 int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr) 78 { 79 struct bpf_offload_netdev *ondev; 80 struct bpf_prog_offload *offload; 81 int err; 82 83 if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS && 84 attr->prog_type != BPF_PROG_TYPE_XDP) 85 return -EINVAL; 86 87 if (attr->prog_flags) 88 return -EINVAL; 89 90 offload = kzalloc(sizeof(*offload), GFP_USER); 91 if (!offload) 92 return -ENOMEM; 93 94 offload->prog = prog; 95 96 offload->netdev = dev_get_by_index(current->nsproxy->net_ns, 97 attr->prog_ifindex); 98 err = bpf_dev_offload_check(offload->netdev); 99 if (err) 100 goto err_maybe_put; 101 102 down_write(&bpf_devs_lock); 103 ondev = bpf_offload_find_netdev(offload->netdev); 104 if (!ondev) { 105 err = -EINVAL; 106 goto err_unlock; 107 } 108 offload->offdev = ondev->offdev; 109 prog->aux->offload = offload; 110 list_add_tail(&offload->offloads, &ondev->progs); 111 dev_put(offload->netdev); 112 up_write(&bpf_devs_lock); 113 114 return 0; 115 err_unlock: 116 up_write(&bpf_devs_lock); 117 err_maybe_put: 118 if (offload->netdev) 119 dev_put(offload->netdev); 120 kfree(offload); 121 return err; 122 } 123 124 int bpf_prog_offload_verifier_prep(struct bpf_prog *prog) 125 { 126 struct bpf_prog_offload *offload; 127 int ret = -ENODEV; 128 129 down_read(&bpf_devs_lock); 130 offload = prog->aux->offload; 131 if (offload) { 132 ret = offload->offdev->ops->prepare(prog); 133 offload->dev_state = !ret; 134 } 135 up_read(&bpf_devs_lock); 136 137 return ret; 138 } 139 140 int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env, 141 int insn_idx, int prev_insn_idx) 142 { 143 struct bpf_prog_offload *offload; 144 int ret = -ENODEV; 145 146 down_read(&bpf_devs_lock); 147 offload = env->prog->aux->offload; 148 if (offload) 149 ret = offload->offdev->ops->insn_hook(env, insn_idx, 150 prev_insn_idx); 151 up_read(&bpf_devs_lock); 152 153 return ret; 154 } 155 156 int bpf_prog_offload_finalize(struct bpf_verifier_env *env) 157 { 158 struct bpf_prog_offload *offload; 159 int ret = -ENODEV; 160 161 down_read(&bpf_devs_lock); 162 offload = env->prog->aux->offload; 163 if (offload) { 164 if (offload->offdev->ops->finalize) 165 ret = offload->offdev->ops->finalize(env); 166 else 167 ret = 0; 168 } 169 up_read(&bpf_devs_lock); 170 171 return ret; 172 } 173 174 void 175 bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off, 176 struct bpf_insn *insn) 177 { 178 const struct bpf_prog_offload_ops *ops; 179 struct bpf_prog_offload *offload; 180 int ret = -EOPNOTSUPP; 181 182 down_read(&bpf_devs_lock); 183 offload = env->prog->aux->offload; 184 if (offload) { 185 ops = offload->offdev->ops; 186 if (!offload->opt_failed && ops->replace_insn) 187 ret = ops->replace_insn(env, off, insn); 188 offload->opt_failed |= ret; 189 } 190 up_read(&bpf_devs_lock); 191 } 192 193 void 194 bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt) 195 { 196 struct bpf_prog_offload *offload; 197 int ret = -EOPNOTSUPP; 198 199 down_read(&bpf_devs_lock); 200 offload = env->prog->aux->offload; 201 if (offload) { 202 if (!offload->opt_failed && offload->offdev->ops->remove_insns) 203 ret = offload->offdev->ops->remove_insns(env, off, cnt); 204 offload->opt_failed |= ret; 205 } 206 up_read(&bpf_devs_lock); 207 } 208 209 static void __bpf_prog_offload_destroy(struct bpf_prog *prog) 210 { 211 struct bpf_prog_offload *offload = prog->aux->offload; 212 213 if (offload->dev_state) 214 offload->offdev->ops->destroy(prog); 215 216 /* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */ 217 bpf_prog_free_id(prog, true); 218 219 list_del_init(&offload->offloads); 220 kfree(offload); 221 prog->aux->offload = NULL; 222 } 223 224 void bpf_prog_offload_destroy(struct bpf_prog *prog) 225 { 226 down_write(&bpf_devs_lock); 227 if (prog->aux->offload) 228 __bpf_prog_offload_destroy(prog); 229 up_write(&bpf_devs_lock); 230 } 231 232 static int bpf_prog_offload_translate(struct bpf_prog *prog) 233 { 234 struct bpf_prog_offload *offload; 235 int ret = -ENODEV; 236 237 down_read(&bpf_devs_lock); 238 offload = prog->aux->offload; 239 if (offload) 240 ret = offload->offdev->ops->translate(prog); 241 up_read(&bpf_devs_lock); 242 243 return ret; 244 } 245 246 static unsigned int bpf_prog_warn_on_exec(const void *ctx, 247 const struct bpf_insn *insn) 248 { 249 WARN(1, "attempt to execute device eBPF program on the host!"); 250 return 0; 251 } 252 253 int bpf_prog_offload_compile(struct bpf_prog *prog) 254 { 255 prog->bpf_func = bpf_prog_warn_on_exec; 256 257 return bpf_prog_offload_translate(prog); 258 } 259 260 struct ns_get_path_bpf_prog_args { 261 struct bpf_prog *prog; 262 struct bpf_prog_info *info; 263 }; 264 265 static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data) 266 { 267 struct ns_get_path_bpf_prog_args *args = private_data; 268 struct bpf_prog_aux *aux = args->prog->aux; 269 struct ns_common *ns; 270 struct net *net; 271 272 rtnl_lock(); 273 down_read(&bpf_devs_lock); 274 275 if (aux->offload) { 276 args->info->ifindex = aux->offload->netdev->ifindex; 277 net = dev_net(aux->offload->netdev); 278 get_net(net); 279 ns = &net->ns; 280 } else { 281 args->info->ifindex = 0; 282 ns = NULL; 283 } 284 285 up_read(&bpf_devs_lock); 286 rtnl_unlock(); 287 288 return ns; 289 } 290 291 int bpf_prog_offload_info_fill(struct bpf_prog_info *info, 292 struct bpf_prog *prog) 293 { 294 struct ns_get_path_bpf_prog_args args = { 295 .prog = prog, 296 .info = info, 297 }; 298 struct bpf_prog_aux *aux = prog->aux; 299 struct inode *ns_inode; 300 struct path ns_path; 301 char __user *uinsns; 302 int res; 303 u32 ulen; 304 305 res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args); 306 if (res) { 307 if (!info->ifindex) 308 return -ENODEV; 309 return res; 310 } 311 312 down_read(&bpf_devs_lock); 313 314 if (!aux->offload) { 315 up_read(&bpf_devs_lock); 316 return -ENODEV; 317 } 318 319 ulen = info->jited_prog_len; 320 info->jited_prog_len = aux->offload->jited_len; 321 if (info->jited_prog_len && ulen) { 322 uinsns = u64_to_user_ptr(info->jited_prog_insns); 323 ulen = min_t(u32, info->jited_prog_len, ulen); 324 if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) { 325 up_read(&bpf_devs_lock); 326 return -EFAULT; 327 } 328 } 329 330 up_read(&bpf_devs_lock); 331 332 ns_inode = ns_path.dentry->d_inode; 333 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev); 334 info->netns_ino = ns_inode->i_ino; 335 path_put(&ns_path); 336 337 return 0; 338 } 339 340 const struct bpf_prog_ops bpf_offload_prog_ops = { 341 }; 342 343 static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap, 344 enum bpf_netdev_command cmd) 345 { 346 struct netdev_bpf data = {}; 347 struct net_device *netdev; 348 349 ASSERT_RTNL(); 350 351 data.command = cmd; 352 data.offmap = offmap; 353 /* Caller must make sure netdev is valid */ 354 netdev = offmap->netdev; 355 356 return netdev->netdev_ops->ndo_bpf(netdev, &data); 357 } 358 359 struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr) 360 { 361 struct net *net = current->nsproxy->net_ns; 362 struct bpf_offload_netdev *ondev; 363 struct bpf_offloaded_map *offmap; 364 int err; 365 366 if (!capable(CAP_SYS_ADMIN)) 367 return ERR_PTR(-EPERM); 368 if (attr->map_type != BPF_MAP_TYPE_ARRAY && 369 attr->map_type != BPF_MAP_TYPE_HASH) 370 return ERR_PTR(-EINVAL); 371 372 offmap = bpf_map_area_alloc(sizeof(*offmap), NUMA_NO_NODE); 373 if (!offmap) 374 return ERR_PTR(-ENOMEM); 375 376 bpf_map_init_from_attr(&offmap->map, attr); 377 378 rtnl_lock(); 379 down_write(&bpf_devs_lock); 380 offmap->netdev = __dev_get_by_index(net, attr->map_ifindex); 381 err = bpf_dev_offload_check(offmap->netdev); 382 if (err) 383 goto err_unlock; 384 385 ondev = bpf_offload_find_netdev(offmap->netdev); 386 if (!ondev) { 387 err = -EINVAL; 388 goto err_unlock; 389 } 390 391 err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC); 392 if (err) 393 goto err_unlock; 394 395 list_add_tail(&offmap->offloads, &ondev->maps); 396 up_write(&bpf_devs_lock); 397 rtnl_unlock(); 398 399 return &offmap->map; 400 401 err_unlock: 402 up_write(&bpf_devs_lock); 403 rtnl_unlock(); 404 bpf_map_area_free(offmap); 405 return ERR_PTR(err); 406 } 407 408 static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap) 409 { 410 WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE)); 411 /* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */ 412 bpf_map_free_id(&offmap->map, true); 413 list_del_init(&offmap->offloads); 414 offmap->netdev = NULL; 415 } 416 417 void bpf_map_offload_map_free(struct bpf_map *map) 418 { 419 struct bpf_offloaded_map *offmap = map_to_offmap(map); 420 421 rtnl_lock(); 422 down_write(&bpf_devs_lock); 423 if (offmap->netdev) 424 __bpf_map_offload_destroy(offmap); 425 up_write(&bpf_devs_lock); 426 rtnl_unlock(); 427 428 bpf_map_area_free(offmap); 429 } 430 431 int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value) 432 { 433 struct bpf_offloaded_map *offmap = map_to_offmap(map); 434 int ret = -ENODEV; 435 436 down_read(&bpf_devs_lock); 437 if (offmap->netdev) 438 ret = offmap->dev_ops->map_lookup_elem(offmap, key, value); 439 up_read(&bpf_devs_lock); 440 441 return ret; 442 } 443 444 int bpf_map_offload_update_elem(struct bpf_map *map, 445 void *key, void *value, u64 flags) 446 { 447 struct bpf_offloaded_map *offmap = map_to_offmap(map); 448 int ret = -ENODEV; 449 450 if (unlikely(flags > BPF_EXIST)) 451 return -EINVAL; 452 453 down_read(&bpf_devs_lock); 454 if (offmap->netdev) 455 ret = offmap->dev_ops->map_update_elem(offmap, key, value, 456 flags); 457 up_read(&bpf_devs_lock); 458 459 return ret; 460 } 461 462 int bpf_map_offload_delete_elem(struct bpf_map *map, void *key) 463 { 464 struct bpf_offloaded_map *offmap = map_to_offmap(map); 465 int ret = -ENODEV; 466 467 down_read(&bpf_devs_lock); 468 if (offmap->netdev) 469 ret = offmap->dev_ops->map_delete_elem(offmap, key); 470 up_read(&bpf_devs_lock); 471 472 return ret; 473 } 474 475 int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key) 476 { 477 struct bpf_offloaded_map *offmap = map_to_offmap(map); 478 int ret = -ENODEV; 479 480 down_read(&bpf_devs_lock); 481 if (offmap->netdev) 482 ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key); 483 up_read(&bpf_devs_lock); 484 485 return ret; 486 } 487 488 struct ns_get_path_bpf_map_args { 489 struct bpf_offloaded_map *offmap; 490 struct bpf_map_info *info; 491 }; 492 493 static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data) 494 { 495 struct ns_get_path_bpf_map_args *args = private_data; 496 struct ns_common *ns; 497 struct net *net; 498 499 rtnl_lock(); 500 down_read(&bpf_devs_lock); 501 502 if (args->offmap->netdev) { 503 args->info->ifindex = args->offmap->netdev->ifindex; 504 net = dev_net(args->offmap->netdev); 505 get_net(net); 506 ns = &net->ns; 507 } else { 508 args->info->ifindex = 0; 509 ns = NULL; 510 } 511 512 up_read(&bpf_devs_lock); 513 rtnl_unlock(); 514 515 return ns; 516 } 517 518 int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map) 519 { 520 struct ns_get_path_bpf_map_args args = { 521 .offmap = map_to_offmap(map), 522 .info = info, 523 }; 524 struct inode *ns_inode; 525 struct path ns_path; 526 int res; 527 528 res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args); 529 if (res) { 530 if (!info->ifindex) 531 return -ENODEV; 532 return res; 533 } 534 535 ns_inode = ns_path.dentry->d_inode; 536 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev); 537 info->netns_ino = ns_inode->i_ino; 538 path_put(&ns_path); 539 540 return 0; 541 } 542 543 static bool __bpf_offload_dev_match(struct bpf_prog *prog, 544 struct net_device *netdev) 545 { 546 struct bpf_offload_netdev *ondev1, *ondev2; 547 struct bpf_prog_offload *offload; 548 549 if (!bpf_prog_is_offloaded(prog->aux)) 550 return false; 551 552 offload = prog->aux->offload; 553 if (!offload) 554 return false; 555 if (offload->netdev == netdev) 556 return true; 557 558 ondev1 = bpf_offload_find_netdev(offload->netdev); 559 ondev2 = bpf_offload_find_netdev(netdev); 560 561 return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev; 562 } 563 564 bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev) 565 { 566 bool ret; 567 568 down_read(&bpf_devs_lock); 569 ret = __bpf_offload_dev_match(prog, netdev); 570 up_read(&bpf_devs_lock); 571 572 return ret; 573 } 574 EXPORT_SYMBOL_GPL(bpf_offload_dev_match); 575 576 bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map) 577 { 578 struct bpf_offloaded_map *offmap; 579 bool ret; 580 581 if (!bpf_map_is_offloaded(map)) 582 return bpf_map_offload_neutral(map); 583 offmap = map_to_offmap(map); 584 585 down_read(&bpf_devs_lock); 586 ret = __bpf_offload_dev_match(prog, offmap->netdev); 587 up_read(&bpf_devs_lock); 588 589 return ret; 590 } 591 592 int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev, 593 struct net_device *netdev) 594 { 595 struct bpf_offload_netdev *ondev; 596 int err; 597 598 ondev = kzalloc(sizeof(*ondev), GFP_KERNEL); 599 if (!ondev) 600 return -ENOMEM; 601 602 ondev->netdev = netdev; 603 ondev->offdev = offdev; 604 INIT_LIST_HEAD(&ondev->progs); 605 INIT_LIST_HEAD(&ondev->maps); 606 607 down_write(&bpf_devs_lock); 608 err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params); 609 if (err) { 610 netdev_warn(netdev, "failed to register for BPF offload\n"); 611 goto err_unlock_free; 612 } 613 614 list_add(&ondev->offdev_netdevs, &offdev->netdevs); 615 up_write(&bpf_devs_lock); 616 return 0; 617 618 err_unlock_free: 619 up_write(&bpf_devs_lock); 620 kfree(ondev); 621 return err; 622 } 623 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register); 624 625 void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev, 626 struct net_device *netdev) 627 { 628 struct bpf_offload_netdev *ondev, *altdev; 629 struct bpf_offloaded_map *offmap, *mtmp; 630 struct bpf_prog_offload *offload, *ptmp; 631 632 ASSERT_RTNL(); 633 634 down_write(&bpf_devs_lock); 635 ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params); 636 if (WARN_ON(!ondev)) 637 goto unlock; 638 639 WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params)); 640 list_del(&ondev->offdev_netdevs); 641 642 /* Try to move the objects to another netdev of the device */ 643 altdev = list_first_entry_or_null(&offdev->netdevs, 644 struct bpf_offload_netdev, 645 offdev_netdevs); 646 if (altdev) { 647 list_for_each_entry(offload, &ondev->progs, offloads) 648 offload->netdev = altdev->netdev; 649 list_splice_init(&ondev->progs, &altdev->progs); 650 651 list_for_each_entry(offmap, &ondev->maps, offloads) 652 offmap->netdev = altdev->netdev; 653 list_splice_init(&ondev->maps, &altdev->maps); 654 } else { 655 list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads) 656 __bpf_prog_offload_destroy(offload->prog); 657 list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads) 658 __bpf_map_offload_destroy(offmap); 659 } 660 661 WARN_ON(!list_empty(&ondev->progs)); 662 WARN_ON(!list_empty(&ondev->maps)); 663 kfree(ondev); 664 unlock: 665 up_write(&bpf_devs_lock); 666 } 667 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister); 668 669 struct bpf_offload_dev * 670 bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv) 671 { 672 struct bpf_offload_dev *offdev; 673 674 offdev = kzalloc(sizeof(*offdev), GFP_KERNEL); 675 if (!offdev) 676 return ERR_PTR(-ENOMEM); 677 678 offdev->ops = ops; 679 offdev->priv = priv; 680 INIT_LIST_HEAD(&offdev->netdevs); 681 682 return offdev; 683 } 684 EXPORT_SYMBOL_GPL(bpf_offload_dev_create); 685 686 void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev) 687 { 688 WARN_ON(!list_empty(&offdev->netdevs)); 689 kfree(offdev); 690 } 691 EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy); 692 693 void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev) 694 { 695 return offdev->priv; 696 } 697 EXPORT_SYMBOL_GPL(bpf_offload_dev_priv); 698 699 static int __init bpf_offload_init(void) 700 { 701 return rhashtable_init(&offdevs, &offdevs_params); 702 } 703 704 late_initcall(bpf_offload_init); 705