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; /* NULL when bound-only */ 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 static int __bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev, 78 struct net_device *netdev) 79 { 80 struct bpf_offload_netdev *ondev; 81 int err; 82 83 ondev = kzalloc(sizeof(*ondev), GFP_KERNEL); 84 if (!ondev) 85 return -ENOMEM; 86 87 ondev->netdev = netdev; 88 ondev->offdev = offdev; 89 INIT_LIST_HEAD(&ondev->progs); 90 INIT_LIST_HEAD(&ondev->maps); 91 92 err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params); 93 if (err) { 94 netdev_warn(netdev, "failed to register for BPF offload\n"); 95 goto err_free; 96 } 97 98 if (offdev) 99 list_add(&ondev->offdev_netdevs, &offdev->netdevs); 100 return 0; 101 102 err_free: 103 kfree(ondev); 104 return err; 105 } 106 107 static void __bpf_prog_offload_destroy(struct bpf_prog *prog) 108 { 109 struct bpf_prog_offload *offload = prog->aux->offload; 110 111 if (offload->dev_state) 112 offload->offdev->ops->destroy(prog); 113 114 list_del_init(&offload->offloads); 115 kfree(offload); 116 prog->aux->offload = NULL; 117 } 118 119 static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap, 120 enum bpf_netdev_command cmd) 121 { 122 struct netdev_bpf data = {}; 123 struct net_device *netdev; 124 125 ASSERT_RTNL(); 126 127 data.command = cmd; 128 data.offmap = offmap; 129 /* Caller must make sure netdev is valid */ 130 netdev = offmap->netdev; 131 132 return netdev->netdev_ops->ndo_bpf(netdev, &data); 133 } 134 135 static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap) 136 { 137 WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE)); 138 /* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */ 139 bpf_map_free_id(&offmap->map); 140 list_del_init(&offmap->offloads); 141 offmap->netdev = NULL; 142 } 143 144 static void __bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev, 145 struct net_device *netdev) 146 { 147 struct bpf_offload_netdev *ondev, *altdev = NULL; 148 struct bpf_offloaded_map *offmap, *mtmp; 149 struct bpf_prog_offload *offload, *ptmp; 150 151 ASSERT_RTNL(); 152 153 ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params); 154 if (WARN_ON(!ondev)) 155 return; 156 157 WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params)); 158 159 /* Try to move the objects to another netdev of the device */ 160 if (offdev) { 161 list_del(&ondev->offdev_netdevs); 162 altdev = list_first_entry_or_null(&offdev->netdevs, 163 struct bpf_offload_netdev, 164 offdev_netdevs); 165 } 166 167 if (altdev) { 168 list_for_each_entry(offload, &ondev->progs, offloads) 169 offload->netdev = altdev->netdev; 170 list_splice_init(&ondev->progs, &altdev->progs); 171 172 list_for_each_entry(offmap, &ondev->maps, offloads) 173 offmap->netdev = altdev->netdev; 174 list_splice_init(&ondev->maps, &altdev->maps); 175 } else { 176 list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads) 177 __bpf_prog_offload_destroy(offload->prog); 178 list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads) 179 __bpf_map_offload_destroy(offmap); 180 } 181 182 WARN_ON(!list_empty(&ondev->progs)); 183 WARN_ON(!list_empty(&ondev->maps)); 184 kfree(ondev); 185 } 186 187 static int __bpf_prog_dev_bound_init(struct bpf_prog *prog, struct net_device *netdev) 188 { 189 struct bpf_offload_netdev *ondev; 190 struct bpf_prog_offload *offload; 191 int err; 192 193 offload = kzalloc(sizeof(*offload), GFP_USER); 194 if (!offload) 195 return -ENOMEM; 196 197 offload->prog = prog; 198 offload->netdev = netdev; 199 200 ondev = bpf_offload_find_netdev(offload->netdev); 201 if (!ondev) { 202 if (bpf_prog_is_offloaded(prog->aux)) { 203 err = -EINVAL; 204 goto err_free; 205 } 206 207 /* When only binding to the device, explicitly 208 * create an entry in the hashtable. 209 */ 210 err = __bpf_offload_dev_netdev_register(NULL, offload->netdev); 211 if (err) 212 goto err_free; 213 ondev = bpf_offload_find_netdev(offload->netdev); 214 } 215 offload->offdev = ondev->offdev; 216 prog->aux->offload = offload; 217 list_add_tail(&offload->offloads, &ondev->progs); 218 219 return 0; 220 err_free: 221 kfree(offload); 222 return err; 223 } 224 225 int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) 226 { 227 struct net_device *netdev; 228 int err; 229 230 if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS && 231 attr->prog_type != BPF_PROG_TYPE_XDP) 232 return -EINVAL; 233 234 if (attr->prog_flags & ~BPF_F_XDP_DEV_BOUND_ONLY) 235 return -EINVAL; 236 237 if (attr->prog_type == BPF_PROG_TYPE_SCHED_CLS && 238 attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY) 239 return -EINVAL; 240 241 netdev = dev_get_by_index(current->nsproxy->net_ns, attr->prog_ifindex); 242 if (!netdev) 243 return -EINVAL; 244 245 err = bpf_dev_offload_check(netdev); 246 if (err) 247 goto out; 248 249 prog->aux->offload_requested = !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY); 250 251 down_write(&bpf_devs_lock); 252 err = __bpf_prog_dev_bound_init(prog, netdev); 253 up_write(&bpf_devs_lock); 254 255 out: 256 dev_put(netdev); 257 return err; 258 } 259 260 int bpf_prog_dev_bound_inherit(struct bpf_prog *new_prog, struct bpf_prog *old_prog) 261 { 262 int err; 263 264 if (!bpf_prog_is_dev_bound(old_prog->aux)) 265 return 0; 266 267 if (bpf_prog_is_offloaded(old_prog->aux)) 268 return -EINVAL; 269 270 new_prog->aux->dev_bound = old_prog->aux->dev_bound; 271 new_prog->aux->offload_requested = old_prog->aux->offload_requested; 272 273 down_write(&bpf_devs_lock); 274 if (!old_prog->aux->offload) { 275 err = -EINVAL; 276 goto out; 277 } 278 279 err = __bpf_prog_dev_bound_init(new_prog, old_prog->aux->offload->netdev); 280 281 out: 282 up_write(&bpf_devs_lock); 283 return err; 284 } 285 286 int bpf_prog_offload_verifier_prep(struct bpf_prog *prog) 287 { 288 struct bpf_prog_offload *offload; 289 int ret = -ENODEV; 290 291 down_read(&bpf_devs_lock); 292 offload = prog->aux->offload; 293 if (offload) { 294 ret = offload->offdev->ops->prepare(prog); 295 offload->dev_state = !ret; 296 } 297 up_read(&bpf_devs_lock); 298 299 return ret; 300 } 301 302 int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env, 303 int insn_idx, int prev_insn_idx) 304 { 305 struct bpf_prog_offload *offload; 306 int ret = -ENODEV; 307 308 down_read(&bpf_devs_lock); 309 offload = env->prog->aux->offload; 310 if (offload) 311 ret = offload->offdev->ops->insn_hook(env, insn_idx, 312 prev_insn_idx); 313 up_read(&bpf_devs_lock); 314 315 return ret; 316 } 317 318 int bpf_prog_offload_finalize(struct bpf_verifier_env *env) 319 { 320 struct bpf_prog_offload *offload; 321 int ret = -ENODEV; 322 323 down_read(&bpf_devs_lock); 324 offload = env->prog->aux->offload; 325 if (offload) { 326 if (offload->offdev->ops->finalize) 327 ret = offload->offdev->ops->finalize(env); 328 else 329 ret = 0; 330 } 331 up_read(&bpf_devs_lock); 332 333 return ret; 334 } 335 336 void 337 bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off, 338 struct bpf_insn *insn) 339 { 340 const struct bpf_prog_offload_ops *ops; 341 struct bpf_prog_offload *offload; 342 int ret = -EOPNOTSUPP; 343 344 down_read(&bpf_devs_lock); 345 offload = env->prog->aux->offload; 346 if (offload) { 347 ops = offload->offdev->ops; 348 if (!offload->opt_failed && ops->replace_insn) 349 ret = ops->replace_insn(env, off, insn); 350 offload->opt_failed |= ret; 351 } 352 up_read(&bpf_devs_lock); 353 } 354 355 void 356 bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt) 357 { 358 struct bpf_prog_offload *offload; 359 int ret = -EOPNOTSUPP; 360 361 down_read(&bpf_devs_lock); 362 offload = env->prog->aux->offload; 363 if (offload) { 364 if (!offload->opt_failed && offload->offdev->ops->remove_insns) 365 ret = offload->offdev->ops->remove_insns(env, off, cnt); 366 offload->opt_failed |= ret; 367 } 368 up_read(&bpf_devs_lock); 369 } 370 371 void bpf_prog_dev_bound_destroy(struct bpf_prog *prog) 372 { 373 struct bpf_offload_netdev *ondev; 374 struct net_device *netdev; 375 376 rtnl_lock(); 377 down_write(&bpf_devs_lock); 378 if (prog->aux->offload) { 379 list_del_init(&prog->aux->offload->offloads); 380 381 netdev = prog->aux->offload->netdev; 382 __bpf_prog_offload_destroy(prog); 383 384 ondev = bpf_offload_find_netdev(netdev); 385 if (!ondev->offdev && list_empty(&ondev->progs)) 386 __bpf_offload_dev_netdev_unregister(NULL, netdev); 387 } 388 up_write(&bpf_devs_lock); 389 rtnl_unlock(); 390 } 391 392 static int bpf_prog_offload_translate(struct bpf_prog *prog) 393 { 394 struct bpf_prog_offload *offload; 395 int ret = -ENODEV; 396 397 down_read(&bpf_devs_lock); 398 offload = prog->aux->offload; 399 if (offload) 400 ret = offload->offdev->ops->translate(prog); 401 up_read(&bpf_devs_lock); 402 403 return ret; 404 } 405 406 static unsigned int bpf_prog_warn_on_exec(const void *ctx, 407 const struct bpf_insn *insn) 408 { 409 WARN(1, "attempt to execute device eBPF program on the host!"); 410 return 0; 411 } 412 413 int bpf_prog_offload_compile(struct bpf_prog *prog) 414 { 415 prog->bpf_func = bpf_prog_warn_on_exec; 416 417 return bpf_prog_offload_translate(prog); 418 } 419 420 struct ns_get_path_bpf_prog_args { 421 struct bpf_prog *prog; 422 struct bpf_prog_info *info; 423 }; 424 425 static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data) 426 { 427 struct ns_get_path_bpf_prog_args *args = private_data; 428 struct bpf_prog_aux *aux = args->prog->aux; 429 struct ns_common *ns; 430 struct net *net; 431 432 rtnl_lock(); 433 down_read(&bpf_devs_lock); 434 435 if (aux->offload) { 436 args->info->ifindex = aux->offload->netdev->ifindex; 437 net = dev_net(aux->offload->netdev); 438 get_net(net); 439 ns = &net->ns; 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); 521 522 rtnl_lock(); 523 down_write(&bpf_devs_lock); 524 offmap->netdev = __dev_get_by_index(net, attr->map_ifindex); 525 err = bpf_dev_offload_check(offmap->netdev); 526 if (err) 527 goto err_unlock; 528 529 ondev = bpf_offload_find_netdev(offmap->netdev); 530 if (!ondev) { 531 err = -EINVAL; 532 goto err_unlock; 533 } 534 535 err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC); 536 if (err) 537 goto err_unlock; 538 539 list_add_tail(&offmap->offloads, &ondev->maps); 540 up_write(&bpf_devs_lock); 541 rtnl_unlock(); 542 543 return &offmap->map; 544 545 err_unlock: 546 up_write(&bpf_devs_lock); 547 rtnl_unlock(); 548 bpf_map_area_free(offmap); 549 return ERR_PTR(err); 550 } 551 552 void bpf_map_offload_map_free(struct bpf_map *map) 553 { 554 struct bpf_offloaded_map *offmap = map_to_offmap(map); 555 556 rtnl_lock(); 557 down_write(&bpf_devs_lock); 558 if (offmap->netdev) 559 __bpf_map_offload_destroy(offmap); 560 up_write(&bpf_devs_lock); 561 rtnl_unlock(); 562 563 bpf_map_area_free(offmap); 564 } 565 566 u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map) 567 { 568 /* The memory dynamically allocated in netdev dev_ops is not counted */ 569 return sizeof(struct bpf_offloaded_map); 570 } 571 572 int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value) 573 { 574 struct bpf_offloaded_map *offmap = map_to_offmap(map); 575 int ret = -ENODEV; 576 577 down_read(&bpf_devs_lock); 578 if (offmap->netdev) 579 ret = offmap->dev_ops->map_lookup_elem(offmap, key, value); 580 up_read(&bpf_devs_lock); 581 582 return ret; 583 } 584 585 int bpf_map_offload_update_elem(struct bpf_map *map, 586 void *key, void *value, u64 flags) 587 { 588 struct bpf_offloaded_map *offmap = map_to_offmap(map); 589 int ret = -ENODEV; 590 591 if (unlikely(flags > BPF_EXIST)) 592 return -EINVAL; 593 594 down_read(&bpf_devs_lock); 595 if (offmap->netdev) 596 ret = offmap->dev_ops->map_update_elem(offmap, key, value, 597 flags); 598 up_read(&bpf_devs_lock); 599 600 return ret; 601 } 602 603 int bpf_map_offload_delete_elem(struct bpf_map *map, void *key) 604 { 605 struct bpf_offloaded_map *offmap = map_to_offmap(map); 606 int ret = -ENODEV; 607 608 down_read(&bpf_devs_lock); 609 if (offmap->netdev) 610 ret = offmap->dev_ops->map_delete_elem(offmap, key); 611 up_read(&bpf_devs_lock); 612 613 return ret; 614 } 615 616 int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key) 617 { 618 struct bpf_offloaded_map *offmap = map_to_offmap(map); 619 int ret = -ENODEV; 620 621 down_read(&bpf_devs_lock); 622 if (offmap->netdev) 623 ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key); 624 up_read(&bpf_devs_lock); 625 626 return ret; 627 } 628 629 struct ns_get_path_bpf_map_args { 630 struct bpf_offloaded_map *offmap; 631 struct bpf_map_info *info; 632 }; 633 634 static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data) 635 { 636 struct ns_get_path_bpf_map_args *args = private_data; 637 struct ns_common *ns; 638 struct net *net; 639 640 rtnl_lock(); 641 down_read(&bpf_devs_lock); 642 643 if (args->offmap->netdev) { 644 args->info->ifindex = args->offmap->netdev->ifindex; 645 net = dev_net(args->offmap->netdev); 646 get_net(net); 647 ns = &net->ns; 648 } else { 649 args->info->ifindex = 0; 650 ns = NULL; 651 } 652 653 up_read(&bpf_devs_lock); 654 rtnl_unlock(); 655 656 return ns; 657 } 658 659 int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map) 660 { 661 struct ns_get_path_bpf_map_args args = { 662 .offmap = map_to_offmap(map), 663 .info = info, 664 }; 665 struct inode *ns_inode; 666 struct path ns_path; 667 int res; 668 669 res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args); 670 if (res) { 671 if (!info->ifindex) 672 return -ENODEV; 673 return res; 674 } 675 676 ns_inode = ns_path.dentry->d_inode; 677 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev); 678 info->netns_ino = ns_inode->i_ino; 679 path_put(&ns_path); 680 681 return 0; 682 } 683 684 static bool __bpf_offload_dev_match(struct bpf_prog *prog, 685 struct net_device *netdev) 686 { 687 struct bpf_offload_netdev *ondev1, *ondev2; 688 struct bpf_prog_offload *offload; 689 690 if (!bpf_prog_is_dev_bound(prog->aux)) 691 return false; 692 693 offload = prog->aux->offload; 694 if (!offload) 695 return false; 696 if (offload->netdev == netdev) 697 return true; 698 699 ondev1 = bpf_offload_find_netdev(offload->netdev); 700 ondev2 = bpf_offload_find_netdev(netdev); 701 702 return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev; 703 } 704 705 bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev) 706 { 707 bool ret; 708 709 down_read(&bpf_devs_lock); 710 ret = __bpf_offload_dev_match(prog, netdev); 711 up_read(&bpf_devs_lock); 712 713 return ret; 714 } 715 EXPORT_SYMBOL_GPL(bpf_offload_dev_match); 716 717 bool bpf_prog_dev_bound_match(const struct bpf_prog *lhs, const struct bpf_prog *rhs) 718 { 719 bool ret; 720 721 if (bpf_prog_is_offloaded(lhs->aux) != bpf_prog_is_offloaded(rhs->aux)) 722 return false; 723 724 down_read(&bpf_devs_lock); 725 ret = lhs->aux->offload && rhs->aux->offload && 726 lhs->aux->offload->netdev && 727 lhs->aux->offload->netdev == rhs->aux->offload->netdev; 728 up_read(&bpf_devs_lock); 729 730 return ret; 731 } 732 733 bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map) 734 { 735 struct bpf_offloaded_map *offmap; 736 bool ret; 737 738 if (!bpf_map_is_offloaded(map)) 739 return bpf_map_offload_neutral(map); 740 offmap = map_to_offmap(map); 741 742 down_read(&bpf_devs_lock); 743 ret = __bpf_offload_dev_match(prog, offmap->netdev); 744 up_read(&bpf_devs_lock); 745 746 return ret; 747 } 748 749 int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev, 750 struct net_device *netdev) 751 { 752 int err; 753 754 down_write(&bpf_devs_lock); 755 err = __bpf_offload_dev_netdev_register(offdev, netdev); 756 up_write(&bpf_devs_lock); 757 return err; 758 } 759 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register); 760 761 void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev, 762 struct net_device *netdev) 763 { 764 down_write(&bpf_devs_lock); 765 __bpf_offload_dev_netdev_unregister(offdev, netdev); 766 up_write(&bpf_devs_lock); 767 } 768 EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister); 769 770 struct bpf_offload_dev * 771 bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv) 772 { 773 struct bpf_offload_dev *offdev; 774 775 offdev = kzalloc(sizeof(*offdev), GFP_KERNEL); 776 if (!offdev) 777 return ERR_PTR(-ENOMEM); 778 779 offdev->ops = ops; 780 offdev->priv = priv; 781 INIT_LIST_HEAD(&offdev->netdevs); 782 783 return offdev; 784 } 785 EXPORT_SYMBOL_GPL(bpf_offload_dev_create); 786 787 void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev) 788 { 789 WARN_ON(!list_empty(&offdev->netdevs)); 790 kfree(offdev); 791 } 792 EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy); 793 794 void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev) 795 { 796 return offdev->priv; 797 } 798 EXPORT_SYMBOL_GPL(bpf_offload_dev_priv); 799 800 void bpf_dev_bound_netdev_unregister(struct net_device *dev) 801 { 802 struct bpf_offload_netdev *ondev; 803 804 ASSERT_RTNL(); 805 806 down_write(&bpf_devs_lock); 807 ondev = bpf_offload_find_netdev(dev); 808 if (ondev && !ondev->offdev) 809 __bpf_offload_dev_netdev_unregister(NULL, ondev->netdev); 810 up_write(&bpf_devs_lock); 811 } 812 813 int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log, 814 struct bpf_prog_aux *prog_aux) 815 { 816 if (!bpf_prog_is_dev_bound(prog_aux)) { 817 bpf_log(log, "metadata kfuncs require device-bound program\n"); 818 return -EINVAL; 819 } 820 821 if (bpf_prog_is_offloaded(prog_aux)) { 822 bpf_log(log, "metadata kfuncs can't be offloaded\n"); 823 return -EINVAL; 824 } 825 826 return 0; 827 } 828 829 void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id) 830 { 831 const struct xdp_metadata_ops *ops; 832 void *p = NULL; 833 834 /* We don't hold bpf_devs_lock while resolving several 835 * kfuncs and can race with the unregister_netdevice(). 836 * We rely on bpf_dev_bound_match() check at attach 837 * to render this program unusable. 838 */ 839 down_read(&bpf_devs_lock); 840 if (!prog->aux->offload) 841 goto out; 842 843 ops = prog->aux->offload->netdev->xdp_metadata_ops; 844 if (!ops) 845 goto out; 846 847 if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_TIMESTAMP)) 848 p = ops->xmo_rx_timestamp; 849 else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_HASH)) 850 p = ops->xmo_rx_hash; 851 out: 852 up_read(&bpf_devs_lock); 853 854 return p; 855 } 856 857 static int __init bpf_offload_init(void) 858 { 859 return rhashtable_init(&offdevs, &offdevs_params); 860 } 861 862 core_initcall(bpf_offload_init); 863