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