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 || !bpf_prog_is_offloaded(prog->aux)) 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 (!tc_cls_can_offload_and_chain0(ns->netdev, &cls_bpf->common)) 127 return -EOPNOTSUPP; 128 129 if (cls_bpf->common.protocol != htons(ETH_P_ALL)) { 130 NSIM_EA(cls_bpf->common.extack, 131 "only ETH_P_ALL supported as filter protocol"); 132 return -EOPNOTSUPP; 133 } 134 135 if (!ns->bpf_tc_accept) { 136 NSIM_EA(cls_bpf->common.extack, 137 "netdevsim configured to reject BPF TC offload"); 138 return -EOPNOTSUPP; 139 } 140 /* Note: progs without skip_sw will probably not be dev bound */ 141 if (prog && !prog->aux->offload && !ns->bpf_tc_non_bound_accept) { 142 NSIM_EA(cls_bpf->common.extack, 143 "netdevsim configured to reject unbound programs"); 144 return -EOPNOTSUPP; 145 } 146 147 /* A dev-bound program can be replayed here when a netdev joins 148 * a shared block, after the core attach-time check has run; 149 * enforce the device match as nfp does. 150 */ 151 if (prog && bpf_prog_is_dev_bound(prog->aux) && 152 !bpf_offload_dev_match(prog, ns->netdev)) { 153 NSIM_EA(cls_bpf->common.extack, 154 "program bound to a different device"); 155 return -EINVAL; 156 } 157 158 if (cls_bpf->command != TC_CLSBPF_OFFLOAD) 159 return -EOPNOTSUPP; 160 161 oldprog = cls_bpf->oldprog; 162 163 /* Don't remove if oldprog doesn't match driver's state */ 164 if (ns->bpf_offloaded != oldprog) { 165 oldprog = NULL; 166 if (!cls_bpf->prog) 167 return 0; 168 if (ns->bpf_offloaded) { 169 NSIM_EA(cls_bpf->common.extack, 170 "driver and netdev offload states mismatch"); 171 return -EBUSY; 172 } 173 } 174 175 return nsim_bpf_offload(ns, cls_bpf->prog, oldprog); 176 } 177 178 int nsim_bpf_disable_tc(struct netdevsim *ns) 179 { 180 if (ns->bpf_offloaded && !nsim_xdp_offload_active(ns)) 181 return -EBUSY; 182 return 0; 183 } 184 185 static int nsim_xdp_offload_prog(struct netdevsim *ns, struct netdev_bpf *bpf) 186 { 187 if (!nsim_xdp_offload_active(ns) && !bpf->prog) 188 return 0; 189 if (!nsim_xdp_offload_active(ns) && bpf->prog && ns->bpf_offloaded) { 190 NSIM_EA(bpf->extack, "TC program is already loaded"); 191 return -EBUSY; 192 } 193 194 return nsim_bpf_offload(ns, bpf->prog, nsim_xdp_offload_active(ns)); 195 } 196 197 static int 198 nsim_xdp_set_prog(struct netdevsim *ns, struct netdev_bpf *bpf, 199 struct xdp_attachment_info *xdp) 200 { 201 int err; 202 203 if (bpf->command == XDP_SETUP_PROG && !ns->bpf_xdpdrv_accept) { 204 NSIM_EA(bpf->extack, "driver XDP disabled in DebugFS"); 205 return -EOPNOTSUPP; 206 } 207 if (bpf->command == XDP_SETUP_PROG_HW && !ns->bpf_xdpoffload_accept) { 208 NSIM_EA(bpf->extack, "XDP offload disabled in DebugFS"); 209 return -EOPNOTSUPP; 210 } 211 212 if (bpf->command == XDP_SETUP_PROG_HW) { 213 err = nsim_xdp_offload_prog(ns, bpf); 214 if (err) 215 return err; 216 } 217 218 xdp_attachment_setup(xdp, bpf); 219 220 return 0; 221 } 222 223 static int nsim_bpf_create_prog(struct nsim_dev *nsim_dev, 224 struct bpf_prog *prog) 225 { 226 struct nsim_bpf_bound_prog *state; 227 char name[16]; 228 int ret; 229 230 state = kzalloc_obj(*state); 231 if (!state) 232 return -ENOMEM; 233 234 state->nsim_dev = nsim_dev; 235 state->prog = prog; 236 state->state = "verify"; 237 238 /* Program id is not populated yet when we create the state. */ 239 sprintf(name, "%u", nsim_dev->prog_id_gen++); 240 state->ddir = debugfs_create_dir(name, nsim_dev->ddir_bpf_bound_progs); 241 if (IS_ERR(state->ddir)) { 242 ret = PTR_ERR(state->ddir); 243 kfree(state); 244 return ret; 245 } 246 247 debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id); 248 debugfs_create_file("state", 0400, state->ddir, 249 &state->state, &nsim_bpf_string_fops); 250 debugfs_create_bool("loaded", 0400, state->ddir, &state->is_loaded); 251 252 mutex_lock(&nsim_dev->progs_list_lock); 253 list_add_tail(&state->l, &nsim_dev->bpf_bound_progs); 254 mutex_unlock(&nsim_dev->progs_list_lock); 255 256 prog->aux->offload->dev_priv = state; 257 258 return 0; 259 } 260 261 static int nsim_bpf_verifier_prep(struct bpf_prog *prog) 262 { 263 struct nsim_dev *nsim_dev = 264 bpf_offload_dev_priv(prog->aux->offload->offdev); 265 266 if (!nsim_dev->bpf_bind_accept) 267 return -EOPNOTSUPP; 268 269 return nsim_bpf_create_prog(nsim_dev, prog); 270 } 271 272 static int nsim_bpf_translate(struct bpf_prog *prog) 273 { 274 struct nsim_bpf_bound_prog *state = prog->aux->offload->dev_priv; 275 276 state->state = "xlated"; 277 return 0; 278 } 279 280 static void nsim_bpf_destroy_prog(struct bpf_prog *prog) 281 { 282 struct nsim_bpf_bound_prog *state; 283 struct nsim_dev *nsim_dev; 284 285 state = prog->aux->offload->dev_priv; 286 nsim_dev = state->nsim_dev; 287 WARN(state->is_loaded, 288 "offload state destroyed while program still bound"); 289 debugfs_remove_recursive(state->ddir); 290 mutex_lock(&nsim_dev->progs_list_lock); 291 list_del(&state->l); 292 mutex_unlock(&nsim_dev->progs_list_lock); 293 kfree(state); 294 } 295 296 static const struct bpf_prog_offload_ops nsim_bpf_dev_ops = { 297 .insn_hook = nsim_bpf_verify_insn, 298 .finalize = nsim_bpf_finalize, 299 .prepare = nsim_bpf_verifier_prep, 300 .translate = nsim_bpf_translate, 301 .destroy = nsim_bpf_destroy_prog, 302 }; 303 304 static int nsim_setup_prog_checks(struct netdevsim *ns, struct netdev_bpf *bpf) 305 { 306 if (bpf->prog && bpf->prog->aux->offload) { 307 NSIM_EA(bpf->extack, "attempt to load offloaded prog to drv"); 308 return -EINVAL; 309 } 310 if (bpf->prog && !bpf->prog->aux->xdp_has_frags && 311 ns->netdev->mtu > NSIM_XDP_MAX_MTU) { 312 NSIM_EA(bpf->extack, "MTU too large w/ XDP enabled"); 313 return -EINVAL; 314 } 315 return 0; 316 } 317 318 static int 319 nsim_setup_prog_hw_checks(struct netdevsim *ns, struct netdev_bpf *bpf) 320 { 321 struct nsim_bpf_bound_prog *state; 322 323 if (!bpf->prog) 324 return 0; 325 326 if (!bpf_prog_is_offloaded(bpf->prog->aux)) { 327 NSIM_EA(bpf->extack, "xdpoffload of non-bound program"); 328 return -EINVAL; 329 } 330 331 state = bpf->prog->aux->offload->dev_priv; 332 if (WARN_ON(strcmp(state->state, "xlated"))) { 333 NSIM_EA(bpf->extack, "offloading program in bad state"); 334 return -EINVAL; 335 } 336 return 0; 337 } 338 339 static bool 340 nsim_map_key_match(struct bpf_map *map, struct nsim_map_entry *e, void *key) 341 { 342 return e->key && !memcmp(key, e->key, map->key_size); 343 } 344 345 static int nsim_map_key_find(struct bpf_offloaded_map *offmap, void *key) 346 { 347 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 348 unsigned int i; 349 350 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) 351 if (nsim_map_key_match(&offmap->map, &nmap->entry[i], key)) 352 return i; 353 354 return -ENOENT; 355 } 356 357 static int 358 nsim_map_alloc_elem(struct bpf_offloaded_map *offmap, unsigned int idx) 359 { 360 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 361 362 nmap->entry[idx].key = kmalloc(offmap->map.key_size, 363 GFP_KERNEL_ACCOUNT | __GFP_NOWARN); 364 if (!nmap->entry[idx].key) 365 return -ENOMEM; 366 nmap->entry[idx].value = kmalloc(offmap->map.value_size, 367 GFP_KERNEL_ACCOUNT | __GFP_NOWARN); 368 if (!nmap->entry[idx].value) { 369 kfree(nmap->entry[idx].key); 370 nmap->entry[idx].key = NULL; 371 return -ENOMEM; 372 } 373 374 return 0; 375 } 376 377 static int 378 nsim_map_get_next_key(struct bpf_offloaded_map *offmap, 379 void *key, void *next_key) 380 { 381 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 382 int idx = -ENOENT; 383 384 mutex_lock(&nmap->mutex); 385 386 if (key) 387 idx = nsim_map_key_find(offmap, key); 388 if (idx == -ENOENT) 389 idx = 0; 390 else 391 idx++; 392 393 for (; idx < ARRAY_SIZE(nmap->entry); idx++) { 394 if (nmap->entry[idx].key) { 395 memcpy(next_key, nmap->entry[idx].key, 396 offmap->map.key_size); 397 break; 398 } 399 } 400 401 mutex_unlock(&nmap->mutex); 402 403 if (idx == ARRAY_SIZE(nmap->entry)) 404 return -ENOENT; 405 return 0; 406 } 407 408 static int 409 nsim_map_lookup_elem(struct bpf_offloaded_map *offmap, void *key, void *value) 410 { 411 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 412 int idx; 413 414 mutex_lock(&nmap->mutex); 415 416 idx = nsim_map_key_find(offmap, key); 417 if (idx >= 0) 418 memcpy(value, nmap->entry[idx].value, offmap->map.value_size); 419 420 mutex_unlock(&nmap->mutex); 421 422 return idx < 0 ? idx : 0; 423 } 424 425 static int 426 nsim_map_update_elem(struct bpf_offloaded_map *offmap, 427 void *key, void *value, u64 flags) 428 { 429 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 430 int idx, err = 0; 431 432 mutex_lock(&nmap->mutex); 433 434 idx = nsim_map_key_find(offmap, key); 435 if (idx < 0 && flags == BPF_EXIST) { 436 err = idx; 437 goto exit_unlock; 438 } 439 if (idx >= 0 && flags == BPF_NOEXIST) { 440 err = -EEXIST; 441 goto exit_unlock; 442 } 443 444 if (idx < 0) { 445 for (idx = 0; idx < ARRAY_SIZE(nmap->entry); idx++) 446 if (!nmap->entry[idx].key) 447 break; 448 if (idx == ARRAY_SIZE(nmap->entry)) { 449 err = -E2BIG; 450 goto exit_unlock; 451 } 452 453 err = nsim_map_alloc_elem(offmap, idx); 454 if (err) 455 goto exit_unlock; 456 } 457 458 memcpy(nmap->entry[idx].key, key, offmap->map.key_size); 459 memcpy(nmap->entry[idx].value, value, offmap->map.value_size); 460 exit_unlock: 461 mutex_unlock(&nmap->mutex); 462 463 return err; 464 } 465 466 static int nsim_map_delete_elem(struct bpf_offloaded_map *offmap, void *key) 467 { 468 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 469 int idx; 470 471 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) 472 return -EINVAL; 473 474 mutex_lock(&nmap->mutex); 475 476 idx = nsim_map_key_find(offmap, key); 477 if (idx >= 0) { 478 kfree(nmap->entry[idx].key); 479 kfree(nmap->entry[idx].value); 480 memset(&nmap->entry[idx], 0, sizeof(nmap->entry[idx])); 481 } 482 483 mutex_unlock(&nmap->mutex); 484 485 return idx < 0 ? idx : 0; 486 } 487 488 static const struct bpf_map_dev_ops nsim_bpf_map_ops = { 489 .map_get_next_key = nsim_map_get_next_key, 490 .map_lookup_elem = nsim_map_lookup_elem, 491 .map_update_elem = nsim_map_update_elem, 492 .map_delete_elem = nsim_map_delete_elem, 493 }; 494 495 static int 496 nsim_bpf_map_alloc(struct netdevsim *ns, struct bpf_offloaded_map *offmap) 497 { 498 struct nsim_bpf_bound_map *nmap; 499 int i, err; 500 501 if (WARN_ON(offmap->map.map_type != BPF_MAP_TYPE_ARRAY && 502 offmap->map.map_type != BPF_MAP_TYPE_HASH)) 503 return -EINVAL; 504 if (offmap->map.max_entries > NSIM_BPF_MAX_KEYS) 505 return -ENOMEM; 506 if (offmap->map.map_flags) 507 return -EINVAL; 508 509 nmap = kzalloc_obj(*nmap, GFP_KERNEL_ACCOUNT); 510 if (!nmap) 511 return -ENOMEM; 512 513 offmap->dev_priv = nmap; 514 nmap->ns = ns; 515 nmap->map = offmap; 516 mutex_init(&nmap->mutex); 517 518 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) { 519 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) { 520 u32 *key; 521 522 err = nsim_map_alloc_elem(offmap, i); 523 if (err) 524 goto err_free; 525 key = nmap->entry[i].key; 526 *key = i; 527 memset(nmap->entry[i].value, 0, offmap->map.value_size); 528 } 529 } 530 531 offmap->dev_ops = &nsim_bpf_map_ops; 532 list_add_tail(&nmap->l, &ns->nsim_dev->bpf_bound_maps); 533 534 return 0; 535 536 err_free: 537 while (--i >= 0) { 538 kfree(nmap->entry[i].key); 539 kfree(nmap->entry[i].value); 540 } 541 kfree(nmap); 542 return err; 543 } 544 545 static void nsim_bpf_map_free(struct bpf_offloaded_map *offmap) 546 { 547 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 548 unsigned int i; 549 550 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) { 551 kfree(nmap->entry[i].key); 552 kfree(nmap->entry[i].value); 553 } 554 list_del_init(&nmap->l); 555 mutex_destroy(&nmap->mutex); 556 kfree(nmap); 557 } 558 559 int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf) 560 { 561 struct netdevsim *ns = netdev_priv(dev); 562 int err; 563 564 ASSERT_RTNL(); 565 566 switch (bpf->command) { 567 case XDP_SETUP_PROG: 568 err = nsim_setup_prog_checks(ns, bpf); 569 if (err) 570 return err; 571 572 return nsim_xdp_set_prog(ns, bpf, &ns->xdp); 573 case XDP_SETUP_PROG_HW: 574 err = nsim_setup_prog_hw_checks(ns, bpf); 575 if (err) 576 return err; 577 578 return nsim_xdp_set_prog(ns, bpf, &ns->xdp_hw); 579 case BPF_OFFLOAD_MAP_ALLOC: 580 if (!ns->bpf_map_accept) 581 return -EOPNOTSUPP; 582 583 return nsim_bpf_map_alloc(ns, bpf->offmap); 584 case BPF_OFFLOAD_MAP_FREE: 585 nsim_bpf_map_free(bpf->offmap); 586 return 0; 587 default: 588 return -EINVAL; 589 } 590 } 591 592 int nsim_bpf_dev_init(struct nsim_dev *nsim_dev) 593 { 594 int err; 595 596 INIT_LIST_HEAD(&nsim_dev->bpf_bound_progs); 597 INIT_LIST_HEAD(&nsim_dev->bpf_bound_maps); 598 599 nsim_dev->ddir_bpf_bound_progs = debugfs_create_dir("bpf_bound_progs", 600 nsim_dev->ddir); 601 if (IS_ERR(nsim_dev->ddir_bpf_bound_progs)) 602 return PTR_ERR(nsim_dev->ddir_bpf_bound_progs); 603 604 nsim_dev->bpf_dev = bpf_offload_dev_create(&nsim_bpf_dev_ops, nsim_dev); 605 err = PTR_ERR_OR_ZERO(nsim_dev->bpf_dev); 606 if (err) 607 return err; 608 609 nsim_dev->bpf_bind_accept = true; 610 debugfs_create_bool("bpf_bind_accept", 0600, nsim_dev->ddir, 611 &nsim_dev->bpf_bind_accept); 612 debugfs_create_u32("bpf_bind_verifier_delay", 0600, nsim_dev->ddir, 613 &nsim_dev->bpf_bind_verifier_delay); 614 nsim_dev->bpf_bind_verifier_accept = true; 615 debugfs_create_bool("bpf_bind_verifier_accept", 0600, nsim_dev->ddir, 616 &nsim_dev->bpf_bind_verifier_accept); 617 return 0; 618 } 619 620 void nsim_bpf_dev_exit(struct nsim_dev *nsim_dev) 621 { 622 WARN_ON(!list_empty(&nsim_dev->bpf_bound_progs)); 623 WARN_ON(!list_empty(&nsim_dev->bpf_bound_maps)); 624 bpf_offload_dev_destroy(nsim_dev->bpf_dev); 625 } 626 627 int nsim_bpf_init(struct netdevsim *ns) 628 { 629 struct dentry *ddir = ns->nsim_dev_port->ddir; 630 int err; 631 632 err = bpf_offload_dev_netdev_register(ns->nsim_dev->bpf_dev, 633 ns->netdev); 634 if (err) 635 return err; 636 637 debugfs_create_u32("bpf_offloaded_id", 0400, ddir, 638 &ns->bpf_offloaded_id); 639 640 ns->bpf_tc_accept = true; 641 debugfs_create_bool("bpf_tc_accept", 0600, ddir, 642 &ns->bpf_tc_accept); 643 debugfs_create_bool("bpf_tc_non_bound_accept", 0600, ddir, 644 &ns->bpf_tc_non_bound_accept); 645 ns->bpf_xdpdrv_accept = true; 646 debugfs_create_bool("bpf_xdpdrv_accept", 0600, ddir, 647 &ns->bpf_xdpdrv_accept); 648 ns->bpf_xdpoffload_accept = true; 649 debugfs_create_bool("bpf_xdpoffload_accept", 0600, ddir, 650 &ns->bpf_xdpoffload_accept); 651 652 ns->bpf_map_accept = true; 653 debugfs_create_bool("bpf_map_accept", 0600, ddir, 654 &ns->bpf_map_accept); 655 656 return 0; 657 } 658 659 void nsim_bpf_uninit(struct netdevsim *ns) 660 { 661 WARN_ON(ns->xdp.prog); 662 WARN_ON(ns->xdp_hw.prog); 663 WARN_ON(ns->bpf_offloaded); 664 bpf_offload_dev_netdev_unregister(ns->nsim_dev->bpf_dev, ns->netdev); 665 } 666