1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2017-2018 Netronome Systems, Inc. 4 */ 5 6 #include <linux/bpf.h> 7 #include <linux/bpf_verifier.h> 8 #include <linux/bug.h> 9 #include <linux/kdev_t.h> 10 #include <linux/list.h> 11 #include <linux/lockdep.h> 12 #include <linux/netdevice.h> 13 #include <linux/printk.h> 14 #include <linux/proc_ns.h> 15 #include <linux/rhashtable.h> 16 #include <linux/rtnetlink.h> 17 #include <linux/rwsem.h> 18 #include <net/netdev_lock.h> 19 #include <net/xdp.h> 20 21 /* Protects offdevs, members of bpf_offload_netdev and offload members 22 * of all progs. 23 * RTNL lock cannot be taken when holding this lock. 24 */ 25 static DECLARE_RWSEM(bpf_devs_lock); 26 27 struct bpf_offload_dev { 28 const struct bpf_prog_offload_ops *ops; 29 struct list_head netdevs; 30 void *priv; 31 }; 32 33 struct bpf_offload_netdev { 34 struct rhash_head l; 35 struct net_device *netdev; 36 struct bpf_offload_dev *offdev; /* NULL when bound-only */ 37 struct list_head progs; 38 struct list_head maps; 39 struct list_head offdev_netdevs; 40 }; 41 42 static const struct rhashtable_params offdevs_params = { 43 .nelem_hint = 4, 44 .key_len = sizeof(struct net_device *), 45 .key_offset = offsetof(struct bpf_offload_netdev, netdev), 46 .head_offset = offsetof(struct bpf_offload_netdev, l), 47 .automatic_shrinking = true, 48 }; 49 50 static struct rhashtable offdevs; 51 52 static int bpf_dev_offload_check(struct net_device *netdev) 53 { 54 if (!netdev) 55 return -EINVAL; 56 if (!netdev->netdev_ops->ndo_bpf) 57 return -EOPNOTSUPP; 58 return 0; 59 } 60 61 static struct bpf_offload_netdev * 62 bpf_offload_find_netdev(struct net_device *netdev) 63 { 64 lockdep_assert_held(&bpf_devs_lock); 65 66 return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params); 67 } 68 69 static int __bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev, 70 struct net_device *netdev) 71 { 72 struct bpf_offload_netdev *ondev; 73 int err; 74 75 ondev = kzalloc_obj(*ondev); 76 if (!ondev) 77 return -ENOMEM; 78 79 ondev->netdev = netdev; 80 ondev->offdev = offdev; 81 INIT_LIST_HEAD(&ondev->progs); 82 INIT_LIST_HEAD(&ondev->maps); 83 84 err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params); 85 if (err) { 86 netdev_warn(netdev, "failed to register for BPF offload\n"); 87 goto err_free; 88 } 89 90 if (offdev) 91 list_add(&ondev->offdev_netdevs, &offdev->netdevs); 92 return 0; 93 94 err_free: 95 kfree(ondev); 96 return err; 97 } 98 99 /* 100 * @prog takes the place of a copy that the caller is about to free. Nothing 101 * keeps the netdev while a program is loaded: once the lock is dropped, no 102 * unregistration is left that has got the old copy from offload->prog. 103 */ 104 void bpf_prog_dev_bound_moved(struct bpf_prog *prog) 105 { 106 if (!bpf_prog_is_dev_bound(prog->aux)) 107 return; 108 109 down_read(&bpf_devs_lock); 110 if (prog->aux->offload) 111 prog->aux->offload->prog = prog; 112 up_read(&bpf_devs_lock); 113 } 114 115 static void __bpf_prog_offload_destroy(struct bpf_prog *prog) 116 { 117 struct bpf_prog_offload *offload = prog->aux->offload; 118 119 if (offload->dev_state) 120 offload->offdev->ops->destroy(prog); 121 122 list_del_init(&offload->offloads); 123 kfree(offload); 124 prog->aux->offload = NULL; 125 } 126 127 static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap, 128 enum bpf_netdev_command cmd) 129 { 130 struct netdev_bpf data = {}; 131 struct net_device *netdev; 132 133 ASSERT_RTNL(); 134 135 data.command = cmd; 136 data.offmap = offmap; 137 /* Caller must make sure netdev is valid */ 138 netdev = offmap->netdev; 139 140 return netdev->netdev_ops->ndo_bpf(netdev, &data); 141 } 142 143 static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap) 144 { 145 WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE)); 146 /* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */ 147 bpf_map_free_id(&offmap->map); 148 list_del_init(&offmap->offloads); 149 offmap->netdev = NULL; 150 } 151 152 static void __bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev, 153 struct net_device *netdev) 154 { 155 struct bpf_offload_netdev *ondev, *altdev = NULL; 156 struct bpf_offloaded_map *offmap, *mtmp; 157 struct bpf_prog_offload *offload, *ptmp; 158 159 ASSERT_RTNL(); 160 161 ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params); 162 if (WARN_ON(!ondev)) 163 return; 164 165 WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params)); 166 167 /* Try to move the objects to another netdev of the device */ 168 if (offdev) { 169 list_del(&ondev->offdev_netdevs); 170 altdev = list_first_entry_or_null(&offdev->netdevs, 171 struct bpf_offload_netdev, 172 offdev_netdevs); 173 } 174 175 if (altdev) { 176 list_for_each_entry(offload, &ondev->progs, offloads) 177 offload->netdev = altdev->netdev; 178 list_splice_init(&ondev->progs, &altdev->progs); 179 180 list_for_each_entry(offmap, &ondev->maps, offloads) 181 offmap->netdev = altdev->netdev; 182 list_splice_init(&ondev->maps, &altdev->maps); 183 } else { 184 list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads) 185 __bpf_prog_offload_destroy(offload->prog); 186 list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads) 187 __bpf_map_offload_destroy(offmap); 188 } 189 190 WARN_ON(!list_empty(&ondev->progs)); 191 WARN_ON(!list_empty(&ondev->maps)); 192 kfree(ondev); 193 } 194 195 static int __bpf_prog_dev_bound_init(struct bpf_prog *prog, struct net_device *netdev) 196 { 197 struct bpf_offload_netdev *ondev; 198 struct bpf_prog_offload *offload; 199 int err; 200 201 offload = kzalloc_obj(*offload, GFP_USER); 202 if (!offload) 203 return -ENOMEM; 204 205 offload->prog = prog; 206 offload->netdev = netdev; 207 208 ondev = bpf_offload_find_netdev(offload->netdev); 209 /* When program is offloaded require presence of "true" 210 * bpf_offload_netdev, avoid the one created for !ondev case below. 211 */ 212 if (bpf_prog_is_offloaded(prog->aux) && (!ondev || !ondev->offdev)) { 213 err = -EINVAL; 214 goto err_free; 215 } 216 if (!ondev) { 217 /* When only binding to the device, explicitly 218 * create an entry in the hashtable. 219 */ 220 err = __bpf_offload_dev_netdev_register(NULL, offload->netdev); 221 if (err) 222 goto err_free; 223 ondev = bpf_offload_find_netdev(offload->netdev); 224 } 225 offload->offdev = ondev->offdev; 226 prog->aux->offload = offload; 227 list_add_tail(&offload->offloads, &ondev->progs); 228 229 return 0; 230 err_free: 231 kfree(offload); 232 return err; 233 } 234 235 int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) 236 { 237 struct net_device *netdev; 238 int err; 239 240 if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS && 241 attr->prog_type != BPF_PROG_TYPE_XDP) 242 return -EINVAL; 243 244 if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS)) 245 return -EINVAL; 246 247 /* Frags are allowed only if program is dev-bound-only, but not 248 * if it is requesting bpf offload. 249 */ 250 if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS && 251 !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)) 252 return -EINVAL; 253 254 if (attr->prog_type == BPF_PROG_TYPE_SCHED_CLS && 255 attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY) 256 return -EINVAL; 257 258 netdev = dev_get_by_index(current->nsproxy->net_ns, attr->prog_ifindex); 259 if (!netdev) 260 return -EINVAL; 261 262 err = bpf_dev_offload_check(netdev); 263 if (err) 264 goto out; 265 266 prog->aux->offload_requested = !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY); 267 268 down_write(&bpf_devs_lock); 269 /* 270 * Behind bpf_dev_bound_netdev_unregister() nobody would take the 271 * program off the device, which goes once the reference is dropped. 272 */ 273 if (READ_ONCE(netdev->reg_state) == NETREG_REGISTERED) 274 err = __bpf_prog_dev_bound_init(prog, netdev); 275 else 276 err = -EINVAL; 277 up_write(&bpf_devs_lock); 278 279 out: 280 dev_put(netdev); 281 return err; 282 } 283 284 int bpf_prog_dev_bound_inherit(struct bpf_prog *new_prog, struct bpf_prog *old_prog) 285 { 286 int err; 287 288 if (!bpf_prog_is_dev_bound(old_prog->aux)) 289 return 0; 290 291 if (bpf_prog_is_offloaded(old_prog->aux)) 292 return -EINVAL; 293 294 new_prog->aux->dev_bound = old_prog->aux->dev_bound; 295 new_prog->aux->offload_requested = old_prog->aux->offload_requested; 296 297 down_write(&bpf_devs_lock); 298 if (!old_prog->aux->offload) { 299 err = -EINVAL; 300 goto out; 301 } 302 303 err = __bpf_prog_dev_bound_init(new_prog, old_prog->aux->offload->netdev); 304 305 out: 306 up_write(&bpf_devs_lock); 307 return err; 308 } 309 310 int bpf_prog_offload_verifier_prep(struct bpf_prog *prog) 311 { 312 struct bpf_prog_offload *offload; 313 int ret = -ENODEV; 314 315 down_read(&bpf_devs_lock); 316 offload = prog->aux->offload; 317 if (offload) { 318 ret = offload->offdev->ops->prepare(prog); 319 offload->dev_state = !ret; 320 } 321 up_read(&bpf_devs_lock); 322 323 return ret; 324 } 325 326 int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env, 327 int insn_idx, int prev_insn_idx) 328 { 329 struct bpf_prog_offload *offload; 330 int ret = -ENODEV; 331 332 down_read(&bpf_devs_lock); 333 offload = env->prog->aux->offload; 334 if (offload) 335 ret = offload->offdev->ops->insn_hook(env, insn_idx, 336 prev_insn_idx); 337 up_read(&bpf_devs_lock); 338 339 return ret; 340 } 341 342 int bpf_prog_offload_finalize(struct bpf_verifier_env *env) 343 { 344 struct bpf_prog_offload *offload; 345 int ret = -ENODEV; 346 347 down_read(&bpf_devs_lock); 348 offload = env->prog->aux->offload; 349 if (offload) { 350 if (offload->offdev->ops->finalize) 351 ret = offload->offdev->ops->finalize(env); 352 else 353 ret = 0; 354 } 355 up_read(&bpf_devs_lock); 356 357 return ret; 358 } 359 360 void 361 bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off, 362 struct bpf_insn *insn) 363 { 364 const struct bpf_prog_offload_ops *ops; 365 struct bpf_prog_offload *offload; 366 int ret = -EOPNOTSUPP; 367 368 down_read(&bpf_devs_lock); 369 offload = env->prog->aux->offload; 370 if (offload) { 371 ops = offload->offdev->ops; 372 if (!offload->opt_failed && ops->replace_insn) 373 ret = ops->replace_insn(env, off, insn); 374 offload->opt_failed |= ret; 375 } 376 up_read(&bpf_devs_lock); 377 } 378 379 void 380 bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt) 381 { 382 struct bpf_prog_offload *offload; 383 int ret = -EOPNOTSUPP; 384 385 down_read(&bpf_devs_lock); 386 offload = env->prog->aux->offload; 387 if (offload) { 388 if (!offload->opt_failed && offload->offdev->ops->remove_insns) 389 ret = offload->offdev->ops->remove_insns(env, off, cnt); 390 offload->opt_failed |= ret; 391 } 392 up_read(&bpf_devs_lock); 393 } 394 395 void bpf_prog_dev_bound_destroy(struct bpf_prog *prog) 396 { 397 struct bpf_offload_netdev *ondev; 398 struct net_device *netdev; 399 400 rtnl_lock(); 401 down_write(&bpf_devs_lock); 402 if (prog->aux->offload) { 403 list_del_init(&prog->aux->offload->offloads); 404 405 netdev = prog->aux->offload->netdev; 406 __bpf_prog_offload_destroy(prog); 407 408 ondev = bpf_offload_find_netdev(netdev); 409 if (!ondev->offdev && list_empty(&ondev->progs)) 410 __bpf_offload_dev_netdev_unregister(NULL, netdev); 411 } 412 up_write(&bpf_devs_lock); 413 rtnl_unlock(); 414 } 415 416 static int bpf_prog_offload_translate(struct bpf_prog *prog) 417 { 418 struct bpf_prog_offload *offload; 419 int ret = -ENODEV; 420 421 down_read(&bpf_devs_lock); 422 offload = prog->aux->offload; 423 if (offload) 424 ret = offload->offdev->ops->translate(prog); 425 up_read(&bpf_devs_lock); 426 427 return ret; 428 } 429 430 static unsigned int bpf_prog_warn_on_exec(const void *ctx, 431 const struct bpf_insn *insn) 432 { 433 WARN(1, "attempt to execute device eBPF program on the host!"); 434 return 0; 435 } 436 437 int bpf_prog_offload_compile(struct bpf_prog *prog) 438 { 439 prog->bpf_func = bpf_prog_warn_on_exec; 440 441 return bpf_prog_offload_translate(prog); 442 } 443 444 struct ns_get_path_bpf_prog_args { 445 struct bpf_prog *prog; 446 struct bpf_prog_info *info; 447 }; 448 449 static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data) 450 { 451 struct ns_get_path_bpf_prog_args *args = private_data; 452 struct bpf_prog_aux *aux = args->prog->aux; 453 struct ns_common *ns; 454 struct net *net; 455 456 rtnl_lock(); 457 down_read(&bpf_devs_lock); 458 459 if (aux->offload) { 460 args->info->ifindex = aux->offload->netdev->ifindex; 461 net = maybe_get_net(dev_net(aux->offload->netdev)); 462 ns = net ? &net->ns : NULL; 463 } else { 464 args->info->ifindex = 0; 465 ns = NULL; 466 } 467 468 up_read(&bpf_devs_lock); 469 rtnl_unlock(); 470 471 return ns; 472 } 473 474 int bpf_prog_offload_info_fill(struct bpf_prog_info *info, 475 struct bpf_prog *prog) 476 { 477 struct ns_get_path_bpf_prog_args args = { 478 .prog = prog, 479 .info = info, 480 }; 481 struct bpf_prog_aux *aux = prog->aux; 482 struct inode *ns_inode; 483 struct path ns_path; 484 char __user *uinsns; 485 int res; 486 u32 ulen; 487 488 res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args); 489 if (res) { 490 if (!info->ifindex) 491 return -ENODEV; 492 return res; 493 } 494 495 down_read(&bpf_devs_lock); 496 497 if (!aux->offload) { 498 up_read(&bpf_devs_lock); 499 return -ENODEV; 500 } 501 502 ulen = info->jited_prog_len; 503 info->jited_prog_len = aux->offload->jited_len; 504 if (info->jited_prog_len && ulen) { 505 uinsns = u64_to_user_ptr(info->jited_prog_insns); 506 ulen = min_t(u32, info->jited_prog_len, ulen); 507 if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) { 508 up_read(&bpf_devs_lock); 509 return -EFAULT; 510 } 511 } 512 513 up_read(&bpf_devs_lock); 514 515 ns_inode = ns_path.dentry->d_inode; 516 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev); 517 info->netns_ino = ns_inode->i_ino; 518 path_put(&ns_path); 519 520 return 0; 521 } 522 523 const struct bpf_prog_ops bpf_offload_prog_ops = { 524 }; 525 526 struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr) 527 { 528 struct net *net = current->nsproxy->net_ns; 529 struct bpf_offload_netdev *ondev; 530 struct bpf_offloaded_map *offmap; 531 int err; 532 533 if (!capable(CAP_SYS_ADMIN)) 534 return ERR_PTR(-EPERM); 535 if (attr->map_type != BPF_MAP_TYPE_ARRAY && 536 attr->map_type != BPF_MAP_TYPE_HASH) 537 return ERR_PTR(-EINVAL); 538 539 offmap = bpf_map_area_alloc(sizeof(*offmap), NUMA_NO_NODE); 540 if (!offmap) 541 return ERR_PTR(-ENOMEM); 542 543 bpf_map_init_from_attr(&offmap->map, attr); 544 rtnl_lock(); 545 offmap->netdev = __dev_get_by_index(net, attr->map_ifindex); 546 err = bpf_dev_offload_check(offmap->netdev); 547 if (err) 548 goto err_unlock_rtnl; 549 550 netdev_lock_ops(offmap->netdev); 551 down_write(&bpf_devs_lock); 552 553 ondev = bpf_offload_find_netdev(offmap->netdev); 554 if (!ondev) { 555 err = -EINVAL; 556 goto err_unlock; 557 } 558 559 err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC); 560 if (err) 561 goto err_unlock; 562 563 list_add_tail(&offmap->offloads, &ondev->maps); 564 up_write(&bpf_devs_lock); 565 netdev_unlock_ops(offmap->netdev); 566 rtnl_unlock(); 567 568 return &offmap->map; 569 570 err_unlock: 571 up_write(&bpf_devs_lock); 572 netdev_unlock_ops(offmap->netdev); 573 err_unlock_rtnl: 574 rtnl_unlock(); 575 bpf_map_area_free(offmap); 576 return ERR_PTR(err); 577 } 578 579 void bpf_map_offload_map_free(struct bpf_map *map) 580 { 581 struct bpf_offloaded_map *offmap = map_to_offmap(map); 582 583 rtnl_lock(); 584 down_write(&bpf_devs_lock); 585 if (offmap->netdev) 586 __bpf_map_offload_destroy(offmap); 587 up_write(&bpf_devs_lock); 588 rtnl_unlock(); 589 590 bpf_map_area_free(offmap); 591 } 592 593 u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map) 594 { 595 /* The memory dynamically allocated in netdev dev_ops is not counted */ 596 return sizeof(struct bpf_offloaded_map); 597 } 598 599 int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value) 600 { 601 struct bpf_offloaded_map *offmap = map_to_offmap(map); 602 int ret = -ENODEV; 603 604 down_read(&bpf_devs_lock); 605 if (offmap->netdev) 606 ret = offmap->dev_ops->map_lookup_elem(offmap, key, value); 607 up_read(&bpf_devs_lock); 608 609 return ret; 610 } 611 612 int bpf_map_offload_update_elem(struct bpf_map *map, 613 void *key, void *value, u64 flags) 614 { 615 struct bpf_offloaded_map *offmap = map_to_offmap(map); 616 int ret = -ENODEV; 617 618 if (unlikely(flags > BPF_EXIST)) 619 return -EINVAL; 620 621 down_read(&bpf_devs_lock); 622 if (offmap->netdev) 623 ret = offmap->dev_ops->map_update_elem(offmap, key, value, 624 flags); 625 up_read(&bpf_devs_lock); 626 627 return ret; 628 } 629 630 int bpf_map_offload_delete_elem(struct bpf_map *map, void *key) 631 { 632 struct bpf_offloaded_map *offmap = map_to_offmap(map); 633 int ret = -ENODEV; 634 635 down_read(&bpf_devs_lock); 636 if (offmap->netdev) 637 ret = offmap->dev_ops->map_delete_elem(offmap, key); 638 up_read(&bpf_devs_lock); 639 640 return ret; 641 } 642 643 int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key) 644 { 645 struct bpf_offloaded_map *offmap = map_to_offmap(map); 646 int ret = -ENODEV; 647 648 down_read(&bpf_devs_lock); 649 if (offmap->netdev) 650 ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key); 651 up_read(&bpf_devs_lock); 652 653 return ret; 654 } 655 656 struct ns_get_path_bpf_map_args { 657 struct bpf_offloaded_map *offmap; 658 struct bpf_map_info *info; 659 }; 660 661 static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data) 662 { 663 struct ns_get_path_bpf_map_args *args = private_data; 664 struct ns_common *ns; 665 struct net *net; 666 667 rtnl_lock(); 668 down_read(&bpf_devs_lock); 669 670 if (args->offmap->netdev) { 671 args->info->ifindex = args->offmap->netdev->ifindex; 672 net = maybe_get_net(dev_net(args->offmap->netdev)); 673 ns = net ? &net->ns : NULL; 674 } else { 675 args->info->ifindex = 0; 676 ns = NULL; 677 } 678 679 up_read(&bpf_devs_lock); 680 rtnl_unlock(); 681 682 return ns; 683 } 684 685 int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map) 686 { 687 struct ns_get_path_bpf_map_args args = { 688 .offmap = map_to_offmap(map), 689 .info = info, 690 }; 691 struct inode *ns_inode; 692 struct path ns_path; 693 int res; 694 695 res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args); 696 if (res) { 697 if (!info->ifindex) 698 return -ENODEV; 699 return res; 700 } 701 702 ns_inode = ns_path.dentry->d_inode; 703 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev); 704 info->netns_ino = ns_inode->i_ino; 705 path_put(&ns_path); 706 707 return 0; 708 } 709 710 static bool __bpf_offload_dev_match(struct bpf_prog *prog, 711 struct net_device *netdev) 712 { 713 struct bpf_offload_netdev *ondev1, *ondev2; 714 struct bpf_prog_offload *offload; 715 716 if (!bpf_prog_is_dev_bound(prog->aux)) 717 return false; 718 719 offload = prog->aux->offload; 720 if (!offload) 721 return false; 722 if (offload->netdev == netdev) 723 return true; 724 if (!bpf_prog_is_offloaded(prog->aux)) 725 return false; 726 727 ondev1 = bpf_offload_find_netdev(offload->netdev); 728 ondev2 = bpf_offload_find_netdev(netdev); 729 730 return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev; 731 } 732 733 bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev) 734 { 735 bool ret; 736 737 down_read(&bpf_devs_lock); 738 ret = __bpf_offload_dev_match(prog, netdev); 739 up_read(&bpf_devs_lock); 740 741 return ret; 742 } 743 EXPORT_SYMBOL_GPL(bpf_offload_dev_match); 744 745 bool bpf_prog_dev_bound_match(const struct bpf_prog *lhs, const struct bpf_prog *rhs) 746 { 747 bool ret; 748 749 if (bpf_prog_is_offloaded(lhs->aux) != bpf_prog_is_offloaded(rhs->aux)) 750 return false; 751 752 down_read(&bpf_devs_lock); 753 ret = lhs->aux->offload && rhs->aux->offload && 754 lhs->aux->offload->netdev && 755 lhs->aux->offload->netdev == rhs->aux->offload->netdev; 756 up_read(&bpf_devs_lock); 757 758 return ret; 759 } 760 761 bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map) 762 { 763 struct bpf_offloaded_map *offmap; 764 bool ret; 765 766 if (!bpf_map_is_offloaded(map)) 767 return bpf_map_offload_neutral(map); 768 offmap = map_to_offmap(map); 769 770 down_read(&bpf_devs_lock); 771 ret = __bpf_offload_dev_match(prog, offmap->netdev); 772 up_read(&bpf_devs_lock); 773 774 return ret; 775 } 776 777 int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev, 778 struct net_device *netdev) 779 { 780 int err; 781 782 down_write(&bpf_devs_lock); 783 err = __bpf_offload_dev_netdev_register(offdev, netdev); 784 up_write(&bpf_devs_lock); 785 return err; 786 } 787 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register); 788 789 void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev, 790 struct net_device *netdev) 791 { 792 down_write(&bpf_devs_lock); 793 __bpf_offload_dev_netdev_unregister(offdev, netdev); 794 up_write(&bpf_devs_lock); 795 } 796 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister); 797 798 struct bpf_offload_dev * 799 bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv) 800 { 801 struct bpf_offload_dev *offdev; 802 803 offdev = kzalloc_obj(*offdev); 804 if (!offdev) 805 return ERR_PTR(-ENOMEM); 806 807 offdev->ops = ops; 808 offdev->priv = priv; 809 INIT_LIST_HEAD(&offdev->netdevs); 810 811 return offdev; 812 } 813 EXPORT_SYMBOL_GPL(bpf_offload_dev_create); 814 815 void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev) 816 { 817 WARN_ON(!list_empty(&offdev->netdevs)); 818 kfree(offdev); 819 } 820 EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy); 821 822 void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev) 823 { 824 return offdev->priv; 825 } 826 EXPORT_SYMBOL_GPL(bpf_offload_dev_priv); 827 828 void bpf_dev_bound_netdev_unregister(struct net_device *dev) 829 { 830 struct bpf_offload_netdev *ondev; 831 832 ASSERT_RTNL(); 833 834 down_write(&bpf_devs_lock); 835 ondev = bpf_offload_find_netdev(dev); 836 if (ondev && !ondev->offdev) 837 __bpf_offload_dev_netdev_unregister(NULL, ondev->netdev); 838 up_write(&bpf_devs_lock); 839 } 840 841 int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log, 842 struct bpf_prog_aux *prog_aux) 843 { 844 if (!bpf_prog_is_dev_bound(prog_aux)) { 845 bpf_log(log, "metadata kfuncs require device-bound program\n"); 846 return -EINVAL; 847 } 848 849 if (bpf_prog_is_offloaded(prog_aux)) { 850 bpf_log(log, "metadata kfuncs can't be offloaded\n"); 851 return -EINVAL; 852 } 853 854 return 0; 855 } 856 857 void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id) 858 { 859 const struct xdp_metadata_ops *ops; 860 void *p = NULL; 861 862 /* We don't hold bpf_devs_lock while resolving several 863 * kfuncs and can race with the unregister_netdevice(). 864 * We rely on bpf_dev_bound_match() check at attach 865 * to render this program unusable. 866 */ 867 down_read(&bpf_devs_lock); 868 if (!prog->aux->offload) 869 goto out; 870 871 ops = prog->aux->offload->netdev->xdp_metadata_ops; 872 if (!ops) 873 goto out; 874 875 #define XDP_METADATA_KFUNC(name, _, __, xmo) \ 876 if (func_id == bpf_xdp_metadata_kfunc_id(name)) p = ops->xmo; 877 XDP_METADATA_KFUNC_xxx 878 #undef XDP_METADATA_KFUNC 879 880 out: 881 up_read(&bpf_devs_lock); 882 883 return p; 884 } 885 886 static int __init bpf_offload_init(void) 887 { 888 return rhashtable_init(&offdevs, &offdevs_params); 889 } 890 891 core_initcall(bpf_offload_init); 892