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