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, GFP_USER); 355 if (!nmap->entry[idx].key) 356 return -ENOMEM; 357 nmap->entry[idx].value = kmalloc(offmap->map.value_size, GFP_USER); 358 if (!nmap->entry[idx].value) { 359 kfree(nmap->entry[idx].key); 360 nmap->entry[idx].key = NULL; 361 return -ENOMEM; 362 } 363 364 return 0; 365 } 366 367 static int 368 nsim_map_get_next_key(struct bpf_offloaded_map *offmap, 369 void *key, void *next_key) 370 { 371 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 372 int idx = -ENOENT; 373 374 mutex_lock(&nmap->mutex); 375 376 if (key) 377 idx = nsim_map_key_find(offmap, key); 378 if (idx == -ENOENT) 379 idx = 0; 380 else 381 idx++; 382 383 for (; idx < ARRAY_SIZE(nmap->entry); idx++) { 384 if (nmap->entry[idx].key) { 385 memcpy(next_key, nmap->entry[idx].key, 386 offmap->map.key_size); 387 break; 388 } 389 } 390 391 mutex_unlock(&nmap->mutex); 392 393 if (idx == ARRAY_SIZE(nmap->entry)) 394 return -ENOENT; 395 return 0; 396 } 397 398 static int 399 nsim_map_lookup_elem(struct bpf_offloaded_map *offmap, void *key, void *value) 400 { 401 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 402 int idx; 403 404 mutex_lock(&nmap->mutex); 405 406 idx = nsim_map_key_find(offmap, key); 407 if (idx >= 0) 408 memcpy(value, nmap->entry[idx].value, offmap->map.value_size); 409 410 mutex_unlock(&nmap->mutex); 411 412 return idx < 0 ? idx : 0; 413 } 414 415 static int 416 nsim_map_update_elem(struct bpf_offloaded_map *offmap, 417 void *key, void *value, u64 flags) 418 { 419 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 420 int idx, err = 0; 421 422 mutex_lock(&nmap->mutex); 423 424 idx = nsim_map_key_find(offmap, key); 425 if (idx < 0 && flags == BPF_EXIST) { 426 err = idx; 427 goto exit_unlock; 428 } 429 if (idx >= 0 && flags == BPF_NOEXIST) { 430 err = -EEXIST; 431 goto exit_unlock; 432 } 433 434 if (idx < 0) { 435 for (idx = 0; idx < ARRAY_SIZE(nmap->entry); idx++) 436 if (!nmap->entry[idx].key) 437 break; 438 if (idx == ARRAY_SIZE(nmap->entry)) { 439 err = -E2BIG; 440 goto exit_unlock; 441 } 442 443 err = nsim_map_alloc_elem(offmap, idx); 444 if (err) 445 goto exit_unlock; 446 } 447 448 memcpy(nmap->entry[idx].key, key, offmap->map.key_size); 449 memcpy(nmap->entry[idx].value, value, offmap->map.value_size); 450 exit_unlock: 451 mutex_unlock(&nmap->mutex); 452 453 return err; 454 } 455 456 static int nsim_map_delete_elem(struct bpf_offloaded_map *offmap, void *key) 457 { 458 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 459 int idx; 460 461 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) 462 return -EINVAL; 463 464 mutex_lock(&nmap->mutex); 465 466 idx = nsim_map_key_find(offmap, key); 467 if (idx >= 0) { 468 kfree(nmap->entry[idx].key); 469 kfree(nmap->entry[idx].value); 470 memset(&nmap->entry[idx], 0, sizeof(nmap->entry[idx])); 471 } 472 473 mutex_unlock(&nmap->mutex); 474 475 return idx < 0 ? idx : 0; 476 } 477 478 static const struct bpf_map_dev_ops nsim_bpf_map_ops = { 479 .map_get_next_key = nsim_map_get_next_key, 480 .map_lookup_elem = nsim_map_lookup_elem, 481 .map_update_elem = nsim_map_update_elem, 482 .map_delete_elem = nsim_map_delete_elem, 483 }; 484 485 static int 486 nsim_bpf_map_alloc(struct netdevsim *ns, struct bpf_offloaded_map *offmap) 487 { 488 struct nsim_bpf_bound_map *nmap; 489 int i, err; 490 491 if (WARN_ON(offmap->map.map_type != BPF_MAP_TYPE_ARRAY && 492 offmap->map.map_type != BPF_MAP_TYPE_HASH)) 493 return -EINVAL; 494 if (offmap->map.max_entries > NSIM_BPF_MAX_KEYS) 495 return -ENOMEM; 496 if (offmap->map.map_flags) 497 return -EINVAL; 498 499 nmap = kzalloc(sizeof(*nmap), GFP_USER); 500 if (!nmap) 501 return -ENOMEM; 502 503 offmap->dev_priv = nmap; 504 nmap->ns = ns; 505 nmap->map = offmap; 506 mutex_init(&nmap->mutex); 507 508 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) { 509 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) { 510 u32 *key; 511 512 err = nsim_map_alloc_elem(offmap, i); 513 if (err) 514 goto err_free; 515 key = nmap->entry[i].key; 516 *key = i; 517 } 518 } 519 520 offmap->dev_ops = &nsim_bpf_map_ops; 521 list_add_tail(&nmap->l, &ns->nsim_dev->bpf_bound_maps); 522 523 return 0; 524 525 err_free: 526 while (--i >= 0) { 527 kfree(nmap->entry[i].key); 528 kfree(nmap->entry[i].value); 529 } 530 kfree(nmap); 531 return err; 532 } 533 534 static void nsim_bpf_map_free(struct bpf_offloaded_map *offmap) 535 { 536 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 537 unsigned int i; 538 539 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) { 540 kfree(nmap->entry[i].key); 541 kfree(nmap->entry[i].value); 542 } 543 list_del_init(&nmap->l); 544 mutex_destroy(&nmap->mutex); 545 kfree(nmap); 546 } 547 548 int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf) 549 { 550 struct netdevsim *ns = netdev_priv(dev); 551 int err; 552 553 ASSERT_RTNL(); 554 555 switch (bpf->command) { 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(nsim_dev->ddir_bpf_bound_progs)) 591 return PTR_ERR(nsim_dev->ddir_bpf_bound_progs); 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 nsim_dev->bpf_bind_verifier_accept = true; 604 debugfs_create_bool("bpf_bind_verifier_accept", 0600, nsim_dev->ddir, 605 &nsim_dev->bpf_bind_verifier_accept); 606 return 0; 607 } 608 609 void nsim_bpf_dev_exit(struct nsim_dev *nsim_dev) 610 { 611 WARN_ON(!list_empty(&nsim_dev->bpf_bound_progs)); 612 WARN_ON(!list_empty(&nsim_dev->bpf_bound_maps)); 613 bpf_offload_dev_destroy(nsim_dev->bpf_dev); 614 } 615 616 int nsim_bpf_init(struct netdevsim *ns) 617 { 618 struct dentry *ddir = ns->nsim_dev_port->ddir; 619 int err; 620 621 err = bpf_offload_dev_netdev_register(ns->nsim_dev->bpf_dev, 622 ns->netdev); 623 if (err) 624 return err; 625 626 debugfs_create_u32("bpf_offloaded_id", 0400, ddir, 627 &ns->bpf_offloaded_id); 628 629 ns->bpf_tc_accept = true; 630 debugfs_create_bool("bpf_tc_accept", 0600, ddir, 631 &ns->bpf_tc_accept); 632 debugfs_create_bool("bpf_tc_non_bound_accept", 0600, ddir, 633 &ns->bpf_tc_non_bound_accept); 634 ns->bpf_xdpdrv_accept = true; 635 debugfs_create_bool("bpf_xdpdrv_accept", 0600, ddir, 636 &ns->bpf_xdpdrv_accept); 637 ns->bpf_xdpoffload_accept = true; 638 debugfs_create_bool("bpf_xdpoffload_accept", 0600, ddir, 639 &ns->bpf_xdpoffload_accept); 640 641 ns->bpf_map_accept = true; 642 debugfs_create_bool("bpf_map_accept", 0600, ddir, 643 &ns->bpf_map_accept); 644 645 return 0; 646 } 647 648 void nsim_bpf_uninit(struct netdevsim *ns) 649 { 650 WARN_ON(ns->xdp.prog); 651 WARN_ON(ns->xdp_hw.prog); 652 WARN_ON(ns->bpf_offloaded); 653 bpf_offload_dev_netdev_unregister(ns->nsim_dev->bpf_dev, ns->netdev); 654 } 655