1 /* 2 * Copyright (C) 2017 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/debugfs.h> 19 #include <linux/kernel.h> 20 #include <linux/mutex.h> 21 #include <linux/rtnetlink.h> 22 #include <net/pkt_cls.h> 23 24 #include "netdevsim.h" 25 26 #define pr_vlog(env, fmt, ...) \ 27 bpf_verifier_log_write(env, "[netdevsim] " fmt, ##__VA_ARGS__) 28 29 struct nsim_bpf_bound_prog { 30 struct nsim_dev *nsim_dev; 31 struct bpf_prog *prog; 32 struct dentry *ddir; 33 const char *state; 34 bool is_loaded; 35 struct list_head l; 36 }; 37 38 #define NSIM_BPF_MAX_KEYS 2 39 40 struct nsim_bpf_bound_map { 41 struct netdevsim *ns; 42 struct bpf_offloaded_map *map; 43 struct mutex mutex; 44 struct nsim_map_entry { 45 void *key; 46 void *value; 47 } entry[NSIM_BPF_MAX_KEYS]; 48 struct list_head l; 49 }; 50 51 static int nsim_bpf_string_show(struct seq_file *file, void *data) 52 { 53 const char **str = file->private; 54 55 if (*str) 56 seq_printf(file, "%s\n", *str); 57 58 return 0; 59 } 60 DEFINE_SHOW_ATTRIBUTE(nsim_bpf_string); 61 62 static int 63 nsim_bpf_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn) 64 { 65 struct nsim_bpf_bound_prog *state; 66 int ret = 0; 67 68 state = env->prog->aux->offload->dev_priv; 69 if (state->nsim_dev->bpf_bind_verifier_delay && !insn_idx) 70 msleep(state->nsim_dev->bpf_bind_verifier_delay); 71 72 if (insn_idx == env->prog->len - 1) { 73 pr_vlog(env, "Hello from netdevsim!\n"); 74 75 if (!state->nsim_dev->bpf_bind_verifier_accept) 76 ret = -EOPNOTSUPP; 77 } 78 79 return ret; 80 } 81 82 static int nsim_bpf_finalize(struct bpf_verifier_env *env) 83 { 84 return 0; 85 } 86 87 static bool nsim_xdp_offload_active(struct netdevsim *ns) 88 { 89 return ns->xdp_hw.prog; 90 } 91 92 static void nsim_prog_set_loaded(struct bpf_prog *prog, bool loaded) 93 { 94 struct nsim_bpf_bound_prog *state; 95 96 if (!prog || !prog->aux->offload) 97 return; 98 99 state = prog->aux->offload->dev_priv; 100 state->is_loaded = loaded; 101 } 102 103 static int 104 nsim_bpf_offload(struct netdevsim *ns, struct bpf_prog *prog, bool oldprog) 105 { 106 nsim_prog_set_loaded(ns->bpf_offloaded, false); 107 108 WARN(!!ns->bpf_offloaded != oldprog, 109 "bad offload state, expected offload %sto be active", 110 oldprog ? "" : "not "); 111 ns->bpf_offloaded = prog; 112 ns->bpf_offloaded_id = prog ? prog->aux->id : 0; 113 nsim_prog_set_loaded(prog, true); 114 115 return 0; 116 } 117 118 int nsim_bpf_setup_tc_block_cb(enum tc_setup_type type, 119 void *type_data, void *cb_priv) 120 { 121 struct tc_cls_bpf_offload *cls_bpf = type_data; 122 struct bpf_prog *prog = cls_bpf->prog; 123 struct netdevsim *ns = cb_priv; 124 struct bpf_prog *oldprog; 125 126 if (type != TC_SETUP_CLSBPF) { 127 NSIM_EA(cls_bpf->common.extack, 128 "only offload of BPF classifiers supported"); 129 return -EOPNOTSUPP; 130 } 131 132 if (!tc_cls_can_offload_and_chain0(ns->netdev, &cls_bpf->common)) 133 return -EOPNOTSUPP; 134 135 if (cls_bpf->common.protocol != htons(ETH_P_ALL)) { 136 NSIM_EA(cls_bpf->common.extack, 137 "only ETH_P_ALL supported as filter protocol"); 138 return -EOPNOTSUPP; 139 } 140 141 if (!ns->bpf_tc_accept) { 142 NSIM_EA(cls_bpf->common.extack, 143 "netdevsim configured to reject BPF TC offload"); 144 return -EOPNOTSUPP; 145 } 146 /* Note: progs without skip_sw will probably not be dev bound */ 147 if (prog && !prog->aux->offload && !ns->bpf_tc_non_bound_accept) { 148 NSIM_EA(cls_bpf->common.extack, 149 "netdevsim configured to reject unbound programs"); 150 return -EOPNOTSUPP; 151 } 152 153 if (cls_bpf->command != TC_CLSBPF_OFFLOAD) 154 return -EOPNOTSUPP; 155 156 oldprog = cls_bpf->oldprog; 157 158 /* Don't remove if oldprog doesn't match driver's state */ 159 if (ns->bpf_offloaded != oldprog) { 160 oldprog = NULL; 161 if (!cls_bpf->prog) 162 return 0; 163 if (ns->bpf_offloaded) { 164 NSIM_EA(cls_bpf->common.extack, 165 "driver and netdev offload states mismatch"); 166 return -EBUSY; 167 } 168 } 169 170 return nsim_bpf_offload(ns, cls_bpf->prog, oldprog); 171 } 172 173 int nsim_bpf_disable_tc(struct netdevsim *ns) 174 { 175 if (ns->bpf_offloaded && !nsim_xdp_offload_active(ns)) 176 return -EBUSY; 177 return 0; 178 } 179 180 static int nsim_xdp_offload_prog(struct netdevsim *ns, struct netdev_bpf *bpf) 181 { 182 if (!nsim_xdp_offload_active(ns) && !bpf->prog) 183 return 0; 184 if (!nsim_xdp_offload_active(ns) && bpf->prog && ns->bpf_offloaded) { 185 NSIM_EA(bpf->extack, "TC program is already loaded"); 186 return -EBUSY; 187 } 188 189 return nsim_bpf_offload(ns, bpf->prog, nsim_xdp_offload_active(ns)); 190 } 191 192 static int 193 nsim_xdp_set_prog(struct netdevsim *ns, struct netdev_bpf *bpf, 194 struct xdp_attachment_info *xdp) 195 { 196 int err; 197 198 if (bpf->command == XDP_SETUP_PROG && !ns->bpf_xdpdrv_accept) { 199 NSIM_EA(bpf->extack, "driver XDP disabled in DebugFS"); 200 return -EOPNOTSUPP; 201 } 202 if (bpf->command == XDP_SETUP_PROG_HW && !ns->bpf_xdpoffload_accept) { 203 NSIM_EA(bpf->extack, "XDP offload disabled in DebugFS"); 204 return -EOPNOTSUPP; 205 } 206 207 if (bpf->command == XDP_SETUP_PROG_HW) { 208 err = nsim_xdp_offload_prog(ns, bpf); 209 if (err) 210 return err; 211 } 212 213 xdp_attachment_setup(xdp, bpf); 214 215 return 0; 216 } 217 218 static int nsim_bpf_create_prog(struct nsim_dev *nsim_dev, 219 struct bpf_prog *prog) 220 { 221 struct nsim_bpf_bound_prog *state; 222 char name[16]; 223 int ret; 224 225 state = kzalloc(sizeof(*state), GFP_KERNEL); 226 if (!state) 227 return -ENOMEM; 228 229 state->nsim_dev = nsim_dev; 230 state->prog = prog; 231 state->state = "verify"; 232 233 /* Program id is not populated yet when we create the state. */ 234 sprintf(name, "%u", nsim_dev->prog_id_gen++); 235 state->ddir = debugfs_create_dir(name, nsim_dev->ddir_bpf_bound_progs); 236 if (IS_ERR(state->ddir)) { 237 ret = PTR_ERR(state->ddir); 238 kfree(state); 239 return ret; 240 } 241 242 debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id); 243 debugfs_create_file("state", 0400, state->ddir, 244 &state->state, &nsim_bpf_string_fops); 245 debugfs_create_bool("loaded", 0400, state->ddir, &state->is_loaded); 246 247 list_add_tail(&state->l, &nsim_dev->bpf_bound_progs); 248 249 prog->aux->offload->dev_priv = state; 250 251 return 0; 252 } 253 254 static int nsim_bpf_verifier_prep(struct bpf_prog *prog) 255 { 256 struct nsim_dev *nsim_dev = 257 bpf_offload_dev_priv(prog->aux->offload->offdev); 258 259 if (!nsim_dev->bpf_bind_accept) 260 return -EOPNOTSUPP; 261 262 return nsim_bpf_create_prog(nsim_dev, prog); 263 } 264 265 static int nsim_bpf_translate(struct bpf_prog *prog) 266 { 267 struct nsim_bpf_bound_prog *state = prog->aux->offload->dev_priv; 268 269 state->state = "xlated"; 270 return 0; 271 } 272 273 static void nsim_bpf_destroy_prog(struct bpf_prog *prog) 274 { 275 struct nsim_bpf_bound_prog *state; 276 277 state = prog->aux->offload->dev_priv; 278 WARN(state->is_loaded, 279 "offload state destroyed while program still bound"); 280 debugfs_remove_recursive(state->ddir); 281 list_del(&state->l); 282 kfree(state); 283 } 284 285 static const struct bpf_prog_offload_ops nsim_bpf_dev_ops = { 286 .insn_hook = nsim_bpf_verify_insn, 287 .finalize = nsim_bpf_finalize, 288 .prepare = nsim_bpf_verifier_prep, 289 .translate = nsim_bpf_translate, 290 .destroy = nsim_bpf_destroy_prog, 291 }; 292 293 static int nsim_setup_prog_checks(struct netdevsim *ns, struct netdev_bpf *bpf) 294 { 295 if (bpf->prog && bpf->prog->aux->offload) { 296 NSIM_EA(bpf->extack, "attempt to load offloaded prog to drv"); 297 return -EINVAL; 298 } 299 if (ns->netdev->mtu > NSIM_XDP_MAX_MTU) { 300 NSIM_EA(bpf->extack, "MTU too large w/ XDP enabled"); 301 return -EINVAL; 302 } 303 return 0; 304 } 305 306 static int 307 nsim_setup_prog_hw_checks(struct netdevsim *ns, struct netdev_bpf *bpf) 308 { 309 struct nsim_bpf_bound_prog *state; 310 311 if (!bpf->prog) 312 return 0; 313 314 if (!bpf->prog->aux->offload) { 315 NSIM_EA(bpf->extack, "xdpoffload of non-bound program"); 316 return -EINVAL; 317 } 318 if (!bpf_offload_dev_match(bpf->prog, ns->netdev)) { 319 NSIM_EA(bpf->extack, "program bound to different dev"); 320 return -EINVAL; 321 } 322 323 state = bpf->prog->aux->offload->dev_priv; 324 if (WARN_ON(strcmp(state->state, "xlated"))) { 325 NSIM_EA(bpf->extack, "offloading program in bad state"); 326 return -EINVAL; 327 } 328 return 0; 329 } 330 331 static bool 332 nsim_map_key_match(struct bpf_map *map, struct nsim_map_entry *e, void *key) 333 { 334 return e->key && !memcmp(key, e->key, map->key_size); 335 } 336 337 static int nsim_map_key_find(struct bpf_offloaded_map *offmap, void *key) 338 { 339 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 340 unsigned int i; 341 342 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) 343 if (nsim_map_key_match(&offmap->map, &nmap->entry[i], key)) 344 return i; 345 346 return -ENOENT; 347 } 348 349 static int 350 nsim_map_alloc_elem(struct bpf_offloaded_map *offmap, unsigned int idx) 351 { 352 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 353 354 nmap->entry[idx].key = kmalloc(offmap->map.key_size, 355 GFP_KERNEL_ACCOUNT | __GFP_NOWARN); 356 if (!nmap->entry[idx].key) 357 return -ENOMEM; 358 nmap->entry[idx].value = kmalloc(offmap->map.value_size, 359 GFP_KERNEL_ACCOUNT | __GFP_NOWARN); 360 if (!nmap->entry[idx].value) { 361 kfree(nmap->entry[idx].key); 362 nmap->entry[idx].key = NULL; 363 return -ENOMEM; 364 } 365 366 return 0; 367 } 368 369 static int 370 nsim_map_get_next_key(struct bpf_offloaded_map *offmap, 371 void *key, void *next_key) 372 { 373 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 374 int idx = -ENOENT; 375 376 mutex_lock(&nmap->mutex); 377 378 if (key) 379 idx = nsim_map_key_find(offmap, key); 380 if (idx == -ENOENT) 381 idx = 0; 382 else 383 idx++; 384 385 for (; idx < ARRAY_SIZE(nmap->entry); idx++) { 386 if (nmap->entry[idx].key) { 387 memcpy(next_key, nmap->entry[idx].key, 388 offmap->map.key_size); 389 break; 390 } 391 } 392 393 mutex_unlock(&nmap->mutex); 394 395 if (idx == ARRAY_SIZE(nmap->entry)) 396 return -ENOENT; 397 return 0; 398 } 399 400 static int 401 nsim_map_lookup_elem(struct bpf_offloaded_map *offmap, void *key, void *value) 402 { 403 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 404 int idx; 405 406 mutex_lock(&nmap->mutex); 407 408 idx = nsim_map_key_find(offmap, key); 409 if (idx >= 0) 410 memcpy(value, nmap->entry[idx].value, offmap->map.value_size); 411 412 mutex_unlock(&nmap->mutex); 413 414 return idx < 0 ? idx : 0; 415 } 416 417 static int 418 nsim_map_update_elem(struct bpf_offloaded_map *offmap, 419 void *key, void *value, u64 flags) 420 { 421 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 422 int idx, err = 0; 423 424 mutex_lock(&nmap->mutex); 425 426 idx = nsim_map_key_find(offmap, key); 427 if (idx < 0 && flags == BPF_EXIST) { 428 err = idx; 429 goto exit_unlock; 430 } 431 if (idx >= 0 && flags == BPF_NOEXIST) { 432 err = -EEXIST; 433 goto exit_unlock; 434 } 435 436 if (idx < 0) { 437 for (idx = 0; idx < ARRAY_SIZE(nmap->entry); idx++) 438 if (!nmap->entry[idx].key) 439 break; 440 if (idx == ARRAY_SIZE(nmap->entry)) { 441 err = -E2BIG; 442 goto exit_unlock; 443 } 444 445 err = nsim_map_alloc_elem(offmap, idx); 446 if (err) 447 goto exit_unlock; 448 } 449 450 memcpy(nmap->entry[idx].key, key, offmap->map.key_size); 451 memcpy(nmap->entry[idx].value, value, offmap->map.value_size); 452 exit_unlock: 453 mutex_unlock(&nmap->mutex); 454 455 return err; 456 } 457 458 static int nsim_map_delete_elem(struct bpf_offloaded_map *offmap, void *key) 459 { 460 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 461 int idx; 462 463 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) 464 return -EINVAL; 465 466 mutex_lock(&nmap->mutex); 467 468 idx = nsim_map_key_find(offmap, key); 469 if (idx >= 0) { 470 kfree(nmap->entry[idx].key); 471 kfree(nmap->entry[idx].value); 472 memset(&nmap->entry[idx], 0, sizeof(nmap->entry[idx])); 473 } 474 475 mutex_unlock(&nmap->mutex); 476 477 return idx < 0 ? idx : 0; 478 } 479 480 static const struct bpf_map_dev_ops nsim_bpf_map_ops = { 481 .map_get_next_key = nsim_map_get_next_key, 482 .map_lookup_elem = nsim_map_lookup_elem, 483 .map_update_elem = nsim_map_update_elem, 484 .map_delete_elem = nsim_map_delete_elem, 485 }; 486 487 static int 488 nsim_bpf_map_alloc(struct netdevsim *ns, struct bpf_offloaded_map *offmap) 489 { 490 struct nsim_bpf_bound_map *nmap; 491 int i, err; 492 493 if (WARN_ON(offmap->map.map_type != BPF_MAP_TYPE_ARRAY && 494 offmap->map.map_type != BPF_MAP_TYPE_HASH)) 495 return -EINVAL; 496 if (offmap->map.max_entries > NSIM_BPF_MAX_KEYS) 497 return -ENOMEM; 498 if (offmap->map.map_flags) 499 return -EINVAL; 500 501 nmap = kzalloc(sizeof(*nmap), GFP_KERNEL_ACCOUNT); 502 if (!nmap) 503 return -ENOMEM; 504 505 offmap->dev_priv = nmap; 506 nmap->ns = ns; 507 nmap->map = offmap; 508 mutex_init(&nmap->mutex); 509 510 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) { 511 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) { 512 u32 *key; 513 514 err = nsim_map_alloc_elem(offmap, i); 515 if (err) 516 goto err_free; 517 key = nmap->entry[i].key; 518 *key = i; 519 memset(nmap->entry[i].value, 0, offmap->map.value_size); 520 } 521 } 522 523 offmap->dev_ops = &nsim_bpf_map_ops; 524 list_add_tail(&nmap->l, &ns->nsim_dev->bpf_bound_maps); 525 526 return 0; 527 528 err_free: 529 while (--i >= 0) { 530 kfree(nmap->entry[i].key); 531 kfree(nmap->entry[i].value); 532 } 533 kfree(nmap); 534 return err; 535 } 536 537 static void nsim_bpf_map_free(struct bpf_offloaded_map *offmap) 538 { 539 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 540 unsigned int i; 541 542 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) { 543 kfree(nmap->entry[i].key); 544 kfree(nmap->entry[i].value); 545 } 546 list_del_init(&nmap->l); 547 mutex_destroy(&nmap->mutex); 548 kfree(nmap); 549 } 550 551 int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf) 552 { 553 struct netdevsim *ns = netdev_priv(dev); 554 int err; 555 556 ASSERT_RTNL(); 557 558 switch (bpf->command) { 559 case XDP_SETUP_PROG: 560 err = nsim_setup_prog_checks(ns, bpf); 561 if (err) 562 return err; 563 564 return nsim_xdp_set_prog(ns, bpf, &ns->xdp); 565 case XDP_SETUP_PROG_HW: 566 err = nsim_setup_prog_hw_checks(ns, bpf); 567 if (err) 568 return err; 569 570 return nsim_xdp_set_prog(ns, bpf, &ns->xdp_hw); 571 case BPF_OFFLOAD_MAP_ALLOC: 572 if (!ns->bpf_map_accept) 573 return -EOPNOTSUPP; 574 575 return nsim_bpf_map_alloc(ns, bpf->offmap); 576 case BPF_OFFLOAD_MAP_FREE: 577 nsim_bpf_map_free(bpf->offmap); 578 return 0; 579 default: 580 return -EINVAL; 581 } 582 } 583 584 int nsim_bpf_dev_init(struct nsim_dev *nsim_dev) 585 { 586 int err; 587 588 INIT_LIST_HEAD(&nsim_dev->bpf_bound_progs); 589 INIT_LIST_HEAD(&nsim_dev->bpf_bound_maps); 590 591 nsim_dev->ddir_bpf_bound_progs = debugfs_create_dir("bpf_bound_progs", 592 nsim_dev->ddir); 593 if (IS_ERR(nsim_dev->ddir_bpf_bound_progs)) 594 return PTR_ERR(nsim_dev->ddir_bpf_bound_progs); 595 596 nsim_dev->bpf_dev = bpf_offload_dev_create(&nsim_bpf_dev_ops, nsim_dev); 597 err = PTR_ERR_OR_ZERO(nsim_dev->bpf_dev); 598 if (err) 599 return err; 600 601 nsim_dev->bpf_bind_accept = true; 602 debugfs_create_bool("bpf_bind_accept", 0600, nsim_dev->ddir, 603 &nsim_dev->bpf_bind_accept); 604 debugfs_create_u32("bpf_bind_verifier_delay", 0600, nsim_dev->ddir, 605 &nsim_dev->bpf_bind_verifier_delay); 606 nsim_dev->bpf_bind_verifier_accept = true; 607 debugfs_create_bool("bpf_bind_verifier_accept", 0600, nsim_dev->ddir, 608 &nsim_dev->bpf_bind_verifier_accept); 609 return 0; 610 } 611 612 void nsim_bpf_dev_exit(struct nsim_dev *nsim_dev) 613 { 614 WARN_ON(!list_empty(&nsim_dev->bpf_bound_progs)); 615 WARN_ON(!list_empty(&nsim_dev->bpf_bound_maps)); 616 bpf_offload_dev_destroy(nsim_dev->bpf_dev); 617 } 618 619 int nsim_bpf_init(struct netdevsim *ns) 620 { 621 struct dentry *ddir = ns->nsim_dev_port->ddir; 622 int err; 623 624 err = bpf_offload_dev_netdev_register(ns->nsim_dev->bpf_dev, 625 ns->netdev); 626 if (err) 627 return err; 628 629 debugfs_create_u32("bpf_offloaded_id", 0400, ddir, 630 &ns->bpf_offloaded_id); 631 632 ns->bpf_tc_accept = true; 633 debugfs_create_bool("bpf_tc_accept", 0600, ddir, 634 &ns->bpf_tc_accept); 635 debugfs_create_bool("bpf_tc_non_bound_accept", 0600, ddir, 636 &ns->bpf_tc_non_bound_accept); 637 ns->bpf_xdpdrv_accept = true; 638 debugfs_create_bool("bpf_xdpdrv_accept", 0600, ddir, 639 &ns->bpf_xdpdrv_accept); 640 ns->bpf_xdpoffload_accept = true; 641 debugfs_create_bool("bpf_xdpoffload_accept", 0600, ddir, 642 &ns->bpf_xdpoffload_accept); 643 644 ns->bpf_map_accept = true; 645 debugfs_create_bool("bpf_map_accept", 0600, ddir, 646 &ns->bpf_map_accept); 647 648 return 0; 649 } 650 651 void nsim_bpf_uninit(struct netdevsim *ns) 652 { 653 WARN_ON(ns->xdp.prog); 654 WARN_ON(ns->xdp_hw.prog); 655 WARN_ON(ns->bpf_offloaded); 656 bpf_offload_dev_netdev_unregister(ns->nsim_dev->bpf_dev, ns->netdev); 657 } 658