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(sizeof(*ondev), GFP_KERNEL); 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(sizeof(*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 = dev_net(aux->offload->netdev); 439 get_net(net); 440 ns = &net->ns; 441 } else { 442 args->info->ifindex = 0; 443 ns = NULL; 444 } 445 446 up_read(&bpf_devs_lock); 447 rtnl_unlock(); 448 449 return ns; 450 } 451 452 int bpf_prog_offload_info_fill(struct bpf_prog_info *info, 453 struct bpf_prog *prog) 454 { 455 struct ns_get_path_bpf_prog_args args = { 456 .prog = prog, 457 .info = info, 458 }; 459 struct bpf_prog_aux *aux = prog->aux; 460 struct inode *ns_inode; 461 struct path ns_path; 462 char __user *uinsns; 463 int res; 464 u32 ulen; 465 466 res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args); 467 if (res) { 468 if (!info->ifindex) 469 return -ENODEV; 470 return res; 471 } 472 473 down_read(&bpf_devs_lock); 474 475 if (!aux->offload) { 476 up_read(&bpf_devs_lock); 477 return -ENODEV; 478 } 479 480 ulen = info->jited_prog_len; 481 info->jited_prog_len = aux->offload->jited_len; 482 if (info->jited_prog_len && ulen) { 483 uinsns = u64_to_user_ptr(info->jited_prog_insns); 484 ulen = min_t(u32, info->jited_prog_len, ulen); 485 if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) { 486 up_read(&bpf_devs_lock); 487 return -EFAULT; 488 } 489 } 490 491 up_read(&bpf_devs_lock); 492 493 ns_inode = ns_path.dentry->d_inode; 494 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev); 495 info->netns_ino = ns_inode->i_ino; 496 path_put(&ns_path); 497 498 return 0; 499 } 500 501 const struct bpf_prog_ops bpf_offload_prog_ops = { 502 }; 503 504 struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr) 505 { 506 struct net *net = current->nsproxy->net_ns; 507 struct bpf_offload_netdev *ondev; 508 struct bpf_offloaded_map *offmap; 509 int err; 510 511 if (!capable(CAP_SYS_ADMIN)) 512 return ERR_PTR(-EPERM); 513 if (attr->map_type != BPF_MAP_TYPE_ARRAY && 514 attr->map_type != BPF_MAP_TYPE_HASH) 515 return ERR_PTR(-EINVAL); 516 517 offmap = bpf_map_area_alloc(sizeof(*offmap), NUMA_NO_NODE); 518 if (!offmap) 519 return ERR_PTR(-ENOMEM); 520 521 bpf_map_init_from_attr(&offmap->map, attr); 522 rtnl_lock(); 523 offmap->netdev = __dev_get_by_index(net, attr->map_ifindex); 524 err = bpf_dev_offload_check(offmap->netdev); 525 if (err) 526 goto err_unlock_rtnl; 527 528 netdev_lock_ops(offmap->netdev); 529 down_write(&bpf_devs_lock); 530 531 ondev = bpf_offload_find_netdev(offmap->netdev); 532 if (!ondev) { 533 err = -EINVAL; 534 goto err_unlock; 535 } 536 537 err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC); 538 if (err) 539 goto err_unlock; 540 541 list_add_tail(&offmap->offloads, &ondev->maps); 542 up_write(&bpf_devs_lock); 543 netdev_unlock_ops(offmap->netdev); 544 rtnl_unlock(); 545 546 return &offmap->map; 547 548 err_unlock: 549 up_write(&bpf_devs_lock); 550 netdev_unlock_ops(offmap->netdev); 551 err_unlock_rtnl: 552 rtnl_unlock(); 553 bpf_map_area_free(offmap); 554 return ERR_PTR(err); 555 } 556 557 void bpf_map_offload_map_free(struct bpf_map *map) 558 { 559 struct bpf_offloaded_map *offmap = map_to_offmap(map); 560 561 rtnl_lock(); 562 down_write(&bpf_devs_lock); 563 if (offmap->netdev) 564 __bpf_map_offload_destroy(offmap); 565 up_write(&bpf_devs_lock); 566 rtnl_unlock(); 567 568 bpf_map_area_free(offmap); 569 } 570 571 u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map) 572 { 573 /* The memory dynamically allocated in netdev dev_ops is not counted */ 574 return sizeof(struct bpf_offloaded_map); 575 } 576 577 int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value) 578 { 579 struct bpf_offloaded_map *offmap = map_to_offmap(map); 580 int ret = -ENODEV; 581 582 down_read(&bpf_devs_lock); 583 if (offmap->netdev) 584 ret = offmap->dev_ops->map_lookup_elem(offmap, key, value); 585 up_read(&bpf_devs_lock); 586 587 return ret; 588 } 589 590 int bpf_map_offload_update_elem(struct bpf_map *map, 591 void *key, void *value, u64 flags) 592 { 593 struct bpf_offloaded_map *offmap = map_to_offmap(map); 594 int ret = -ENODEV; 595 596 if (unlikely(flags > BPF_EXIST)) 597 return -EINVAL; 598 599 down_read(&bpf_devs_lock); 600 if (offmap->netdev) 601 ret = offmap->dev_ops->map_update_elem(offmap, key, value, 602 flags); 603 up_read(&bpf_devs_lock); 604 605 return ret; 606 } 607 608 int bpf_map_offload_delete_elem(struct bpf_map *map, void *key) 609 { 610 struct bpf_offloaded_map *offmap = map_to_offmap(map); 611 int ret = -ENODEV; 612 613 down_read(&bpf_devs_lock); 614 if (offmap->netdev) 615 ret = offmap->dev_ops->map_delete_elem(offmap, key); 616 up_read(&bpf_devs_lock); 617 618 return ret; 619 } 620 621 int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key) 622 { 623 struct bpf_offloaded_map *offmap = map_to_offmap(map); 624 int ret = -ENODEV; 625 626 down_read(&bpf_devs_lock); 627 if (offmap->netdev) 628 ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key); 629 up_read(&bpf_devs_lock); 630 631 return ret; 632 } 633 634 struct ns_get_path_bpf_map_args { 635 struct bpf_offloaded_map *offmap; 636 struct bpf_map_info *info; 637 }; 638 639 static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data) 640 { 641 struct ns_get_path_bpf_map_args *args = private_data; 642 struct ns_common *ns; 643 struct net *net; 644 645 rtnl_lock(); 646 down_read(&bpf_devs_lock); 647 648 if (args->offmap->netdev) { 649 args->info->ifindex = args->offmap->netdev->ifindex; 650 net = dev_net(args->offmap->netdev); 651 get_net(net); 652 ns = &net->ns; 653 } else { 654 args->info->ifindex = 0; 655 ns = NULL; 656 } 657 658 up_read(&bpf_devs_lock); 659 rtnl_unlock(); 660 661 return ns; 662 } 663 664 int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map) 665 { 666 struct ns_get_path_bpf_map_args args = { 667 .offmap = map_to_offmap(map), 668 .info = info, 669 }; 670 struct inode *ns_inode; 671 struct path ns_path; 672 int res; 673 674 res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args); 675 if (res) { 676 if (!info->ifindex) 677 return -ENODEV; 678 return res; 679 } 680 681 ns_inode = ns_path.dentry->d_inode; 682 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev); 683 info->netns_ino = ns_inode->i_ino; 684 path_put(&ns_path); 685 686 return 0; 687 } 688 689 static bool __bpf_offload_dev_match(struct bpf_prog *prog, 690 struct net_device *netdev) 691 { 692 struct bpf_offload_netdev *ondev1, *ondev2; 693 struct bpf_prog_offload *offload; 694 695 if (!bpf_prog_is_dev_bound(prog->aux)) 696 return false; 697 698 offload = prog->aux->offload; 699 if (!offload) 700 return false; 701 if (offload->netdev == netdev) 702 return true; 703 704 ondev1 = bpf_offload_find_netdev(offload->netdev); 705 ondev2 = bpf_offload_find_netdev(netdev); 706 707 return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev; 708 } 709 710 bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev) 711 { 712 bool ret; 713 714 down_read(&bpf_devs_lock); 715 ret = __bpf_offload_dev_match(prog, netdev); 716 up_read(&bpf_devs_lock); 717 718 return ret; 719 } 720 EXPORT_SYMBOL_GPL(bpf_offload_dev_match); 721 722 bool bpf_prog_dev_bound_match(const struct bpf_prog *lhs, const struct bpf_prog *rhs) 723 { 724 bool ret; 725 726 if (bpf_prog_is_offloaded(lhs->aux) != bpf_prog_is_offloaded(rhs->aux)) 727 return false; 728 729 down_read(&bpf_devs_lock); 730 ret = lhs->aux->offload && rhs->aux->offload && 731 lhs->aux->offload->netdev && 732 lhs->aux->offload->netdev == rhs->aux->offload->netdev; 733 up_read(&bpf_devs_lock); 734 735 return ret; 736 } 737 738 bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map) 739 { 740 struct bpf_offloaded_map *offmap; 741 bool ret; 742 743 if (!bpf_map_is_offloaded(map)) 744 return bpf_map_offload_neutral(map); 745 offmap = map_to_offmap(map); 746 747 down_read(&bpf_devs_lock); 748 ret = __bpf_offload_dev_match(prog, offmap->netdev); 749 up_read(&bpf_devs_lock); 750 751 return ret; 752 } 753 754 int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev, 755 struct net_device *netdev) 756 { 757 int err; 758 759 down_write(&bpf_devs_lock); 760 err = __bpf_offload_dev_netdev_register(offdev, netdev); 761 up_write(&bpf_devs_lock); 762 return err; 763 } 764 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register); 765 766 void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev, 767 struct net_device *netdev) 768 { 769 down_write(&bpf_devs_lock); 770 __bpf_offload_dev_netdev_unregister(offdev, netdev); 771 up_write(&bpf_devs_lock); 772 } 773 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister); 774 775 struct bpf_offload_dev * 776 bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv) 777 { 778 struct bpf_offload_dev *offdev; 779 780 offdev = kzalloc(sizeof(*offdev), GFP_KERNEL); 781 if (!offdev) 782 return ERR_PTR(-ENOMEM); 783 784 offdev->ops = ops; 785 offdev->priv = priv; 786 INIT_LIST_HEAD(&offdev->netdevs); 787 788 return offdev; 789 } 790 EXPORT_SYMBOL_GPL(bpf_offload_dev_create); 791 792 void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev) 793 { 794 WARN_ON(!list_empty(&offdev->netdevs)); 795 kfree(offdev); 796 } 797 EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy); 798 799 void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev) 800 { 801 return offdev->priv; 802 } 803 EXPORT_SYMBOL_GPL(bpf_offload_dev_priv); 804 805 void bpf_dev_bound_netdev_unregister(struct net_device *dev) 806 { 807 struct bpf_offload_netdev *ondev; 808 809 ASSERT_RTNL(); 810 811 down_write(&bpf_devs_lock); 812 ondev = bpf_offload_find_netdev(dev); 813 if (ondev && !ondev->offdev) 814 __bpf_offload_dev_netdev_unregister(NULL, ondev->netdev); 815 up_write(&bpf_devs_lock); 816 } 817 818 int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log, 819 struct bpf_prog_aux *prog_aux) 820 { 821 if (!bpf_prog_is_dev_bound(prog_aux)) { 822 bpf_log(log, "metadata kfuncs require device-bound program\n"); 823 return -EINVAL; 824 } 825 826 if (bpf_prog_is_offloaded(prog_aux)) { 827 bpf_log(log, "metadata kfuncs can't be offloaded\n"); 828 return -EINVAL; 829 } 830 831 return 0; 832 } 833 834 void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id) 835 { 836 const struct xdp_metadata_ops *ops; 837 void *p = NULL; 838 839 /* We don't hold bpf_devs_lock while resolving several 840 * kfuncs and can race with the unregister_netdevice(). 841 * We rely on bpf_dev_bound_match() check at attach 842 * to render this program unusable. 843 */ 844 down_read(&bpf_devs_lock); 845 if (!prog->aux->offload) 846 goto out; 847 848 ops = prog->aux->offload->netdev->xdp_metadata_ops; 849 if (!ops) 850 goto out; 851 852 #define XDP_METADATA_KFUNC(name, _, __, xmo) \ 853 if (func_id == bpf_xdp_metadata_kfunc_id(name)) p = ops->xmo; 854 XDP_METADATA_KFUNC_xxx 855 #undef XDP_METADATA_KFUNC 856 857 out: 858 up_read(&bpf_devs_lock); 859 860 return p; 861 } 862 863 static int __init bpf_offload_init(void) 864 { 865 return rhashtable_init(&offdevs, &offdevs_params); 866 } 867 868 core_initcall(bpf_offload_init); 869