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