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 bool nsim_xdp_offload_active(struct netdevsim *ns) 95 { 96 return ns->xdp_hw.prog; 97 } 98 99 static void nsim_prog_set_loaded(struct bpf_prog *prog, bool loaded) 100 { 101 struct nsim_bpf_bound_prog *state; 102 103 if (!prog || !prog->aux->offload) 104 return; 105 106 state = prog->aux->offload->dev_priv; 107 state->is_loaded = loaded; 108 } 109 110 static int 111 nsim_bpf_offload(struct netdevsim *ns, struct bpf_prog *prog, bool oldprog) 112 { 113 nsim_prog_set_loaded(ns->bpf_offloaded, false); 114 115 WARN(!!ns->bpf_offloaded != oldprog, 116 "bad offload state, expected offload %sto be active", 117 oldprog ? "" : "not "); 118 ns->bpf_offloaded = prog; 119 ns->bpf_offloaded_id = prog ? prog->aux->id : 0; 120 nsim_prog_set_loaded(prog, true); 121 122 return 0; 123 } 124 125 int nsim_bpf_setup_tc_block_cb(enum tc_setup_type type, 126 void *type_data, void *cb_priv) 127 { 128 struct tc_cls_bpf_offload *cls_bpf = type_data; 129 struct bpf_prog *prog = cls_bpf->prog; 130 struct netdevsim *ns = cb_priv; 131 struct bpf_prog *oldprog; 132 133 if (type != TC_SETUP_CLSBPF) { 134 NSIM_EA(cls_bpf->common.extack, 135 "only offload of BPF classifiers supported"); 136 return -EOPNOTSUPP; 137 } 138 139 if (!tc_cls_can_offload_and_chain0(ns->netdev, &cls_bpf->common)) 140 return -EOPNOTSUPP; 141 142 if (cls_bpf->common.protocol != htons(ETH_P_ALL)) { 143 NSIM_EA(cls_bpf->common.extack, 144 "only ETH_P_ALL supported as filter protocol"); 145 return -EOPNOTSUPP; 146 } 147 148 if (!ns->bpf_tc_accept) { 149 NSIM_EA(cls_bpf->common.extack, 150 "netdevsim configured to reject BPF TC offload"); 151 return -EOPNOTSUPP; 152 } 153 /* Note: progs without skip_sw will probably not be dev bound */ 154 if (prog && !prog->aux->offload && !ns->bpf_tc_non_bound_accept) { 155 NSIM_EA(cls_bpf->common.extack, 156 "netdevsim configured to reject unbound programs"); 157 return -EOPNOTSUPP; 158 } 159 160 if (cls_bpf->command != TC_CLSBPF_OFFLOAD) 161 return -EOPNOTSUPP; 162 163 oldprog = cls_bpf->oldprog; 164 165 /* Don't remove if oldprog doesn't match driver's state */ 166 if (ns->bpf_offloaded != oldprog) { 167 oldprog = NULL; 168 if (!cls_bpf->prog) 169 return 0; 170 if (ns->bpf_offloaded) { 171 NSIM_EA(cls_bpf->common.extack, 172 "driver and netdev offload states mismatch"); 173 return -EBUSY; 174 } 175 } 176 177 return nsim_bpf_offload(ns, cls_bpf->prog, oldprog); 178 } 179 180 int nsim_bpf_disable_tc(struct netdevsim *ns) 181 { 182 if (ns->bpf_offloaded && !nsim_xdp_offload_active(ns)) 183 return -EBUSY; 184 return 0; 185 } 186 187 static int nsim_xdp_offload_prog(struct netdevsim *ns, struct netdev_bpf *bpf) 188 { 189 if (!nsim_xdp_offload_active(ns) && !bpf->prog) 190 return 0; 191 if (!nsim_xdp_offload_active(ns) && bpf->prog && ns->bpf_offloaded) { 192 NSIM_EA(bpf->extack, "TC program is already loaded"); 193 return -EBUSY; 194 } 195 196 return nsim_bpf_offload(ns, bpf->prog, nsim_xdp_offload_active(ns)); 197 } 198 199 static int 200 nsim_xdp_set_prog(struct netdevsim *ns, struct netdev_bpf *bpf, 201 struct xdp_attachment_info *xdp) 202 { 203 int err; 204 205 if (!xdp_attachment_flags_ok(xdp, bpf)) 206 return -EBUSY; 207 208 if (bpf->command == XDP_SETUP_PROG && !ns->bpf_xdpdrv_accept) { 209 NSIM_EA(bpf->extack, "driver XDP disabled in DebugFS"); 210 return -EOPNOTSUPP; 211 } 212 if (bpf->command == XDP_SETUP_PROG_HW && !ns->bpf_xdpoffload_accept) { 213 NSIM_EA(bpf->extack, "XDP offload disabled in DebugFS"); 214 return -EOPNOTSUPP; 215 } 216 217 if (bpf->command == XDP_SETUP_PROG_HW) { 218 err = nsim_xdp_offload_prog(ns, bpf); 219 if (err) 220 return err; 221 } 222 223 xdp_attachment_setup(xdp, bpf); 224 225 return 0; 226 } 227 228 static int nsim_bpf_create_prog(struct netdevsim *ns, struct bpf_prog *prog) 229 { 230 struct nsim_bpf_bound_prog *state; 231 char name[16]; 232 233 state = kzalloc(sizeof(*state), GFP_KERNEL); 234 if (!state) 235 return -ENOMEM; 236 237 state->ns = ns; 238 state->prog = prog; 239 state->state = "verify"; 240 241 /* Program id is not populated yet when we create the state. */ 242 sprintf(name, "%u", ns->sdev->prog_id_gen++); 243 state->ddir = debugfs_create_dir(name, ns->sdev->ddir_bpf_bound_progs); 244 if (IS_ERR_OR_NULL(state->ddir)) { 245 kfree(state); 246 return -ENOMEM; 247 } 248 249 debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id); 250 debugfs_create_file("state", 0400, state->ddir, 251 &state->state, &nsim_bpf_string_fops); 252 debugfs_create_bool("loaded", 0400, state->ddir, &state->is_loaded); 253 254 list_add_tail(&state->l, &ns->sdev->bpf_bound_progs); 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 netdevsim *ns = netdev_priv(prog->aux->offload->netdev); 264 265 if (!ns->bpf_bind_accept) 266 return -EOPNOTSUPP; 267 268 return nsim_bpf_create_prog(ns, prog); 269 } 270 271 static int nsim_bpf_translate(struct bpf_prog *prog) 272 { 273 struct nsim_bpf_bound_prog *state = prog->aux->offload->dev_priv; 274 275 state->state = "xlated"; 276 return 0; 277 } 278 279 static void nsim_bpf_destroy_prog(struct bpf_prog *prog) 280 { 281 struct nsim_bpf_bound_prog *state; 282 283 state = prog->aux->offload->dev_priv; 284 WARN(state->is_loaded, 285 "offload state destroyed while program still bound"); 286 debugfs_remove_recursive(state->ddir); 287 list_del(&state->l); 288 kfree(state); 289 } 290 291 static const struct bpf_prog_offload_ops nsim_bpf_dev_ops = { 292 .insn_hook = nsim_bpf_verify_insn, 293 .finalize = nsim_bpf_finalize, 294 .prepare = nsim_bpf_verifier_prep, 295 .translate = nsim_bpf_translate, 296 .destroy = nsim_bpf_destroy_prog, 297 }; 298 299 static int nsim_setup_prog_checks(struct netdevsim *ns, struct netdev_bpf *bpf) 300 { 301 if (bpf->prog && bpf->prog->aux->offload) { 302 NSIM_EA(bpf->extack, "attempt to load offloaded prog to drv"); 303 return -EINVAL; 304 } 305 if (ns->netdev->mtu > NSIM_XDP_MAX_MTU) { 306 NSIM_EA(bpf->extack, "MTU too large w/ XDP enabled"); 307 return -EINVAL; 308 } 309 return 0; 310 } 311 312 static int 313 nsim_setup_prog_hw_checks(struct netdevsim *ns, struct netdev_bpf *bpf) 314 { 315 struct nsim_bpf_bound_prog *state; 316 317 if (!bpf->prog) 318 return 0; 319 320 if (!bpf->prog->aux->offload) { 321 NSIM_EA(bpf->extack, "xdpoffload of non-bound program"); 322 return -EINVAL; 323 } 324 if (!bpf_offload_dev_match(bpf->prog, ns->netdev)) { 325 NSIM_EA(bpf->extack, "program bound to different dev"); 326 return -EINVAL; 327 } 328 329 state = bpf->prog->aux->offload->dev_priv; 330 if (WARN_ON(strcmp(state->state, "xlated"))) { 331 NSIM_EA(bpf->extack, "offloading program in bad state"); 332 return -EINVAL; 333 } 334 return 0; 335 } 336 337 static bool 338 nsim_map_key_match(struct bpf_map *map, struct nsim_map_entry *e, void *key) 339 { 340 return e->key && !memcmp(key, e->key, map->key_size); 341 } 342 343 static int nsim_map_key_find(struct bpf_offloaded_map *offmap, void *key) 344 { 345 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 346 unsigned int i; 347 348 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) 349 if (nsim_map_key_match(&offmap->map, &nmap->entry[i], key)) 350 return i; 351 352 return -ENOENT; 353 } 354 355 static int 356 nsim_map_alloc_elem(struct bpf_offloaded_map *offmap, unsigned int idx) 357 { 358 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 359 360 nmap->entry[idx].key = kmalloc(offmap->map.key_size, GFP_USER); 361 if (!nmap->entry[idx].key) 362 return -ENOMEM; 363 nmap->entry[idx].value = kmalloc(offmap->map.value_size, GFP_USER); 364 if (!nmap->entry[idx].value) { 365 kfree(nmap->entry[idx].key); 366 nmap->entry[idx].key = NULL; 367 return -ENOMEM; 368 } 369 370 return 0; 371 } 372 373 static int 374 nsim_map_get_next_key(struct bpf_offloaded_map *offmap, 375 void *key, void *next_key) 376 { 377 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 378 int idx = -ENOENT; 379 380 mutex_lock(&nmap->mutex); 381 382 if (key) 383 idx = nsim_map_key_find(offmap, key); 384 if (idx == -ENOENT) 385 idx = 0; 386 else 387 idx++; 388 389 for (; idx < ARRAY_SIZE(nmap->entry); idx++) { 390 if (nmap->entry[idx].key) { 391 memcpy(next_key, nmap->entry[idx].key, 392 offmap->map.key_size); 393 break; 394 } 395 } 396 397 mutex_unlock(&nmap->mutex); 398 399 if (idx == ARRAY_SIZE(nmap->entry)) 400 return -ENOENT; 401 return 0; 402 } 403 404 static int 405 nsim_map_lookup_elem(struct bpf_offloaded_map *offmap, void *key, void *value) 406 { 407 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 408 int idx; 409 410 mutex_lock(&nmap->mutex); 411 412 idx = nsim_map_key_find(offmap, key); 413 if (idx >= 0) 414 memcpy(value, nmap->entry[idx].value, offmap->map.value_size); 415 416 mutex_unlock(&nmap->mutex); 417 418 return idx < 0 ? idx : 0; 419 } 420 421 static int 422 nsim_map_update_elem(struct bpf_offloaded_map *offmap, 423 void *key, void *value, u64 flags) 424 { 425 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 426 int idx, err = 0; 427 428 mutex_lock(&nmap->mutex); 429 430 idx = nsim_map_key_find(offmap, key); 431 if (idx < 0 && flags == BPF_EXIST) { 432 err = idx; 433 goto exit_unlock; 434 } 435 if (idx >= 0 && flags == BPF_NOEXIST) { 436 err = -EEXIST; 437 goto exit_unlock; 438 } 439 440 if (idx < 0) { 441 for (idx = 0; idx < ARRAY_SIZE(nmap->entry); idx++) 442 if (!nmap->entry[idx].key) 443 break; 444 if (idx == ARRAY_SIZE(nmap->entry)) { 445 err = -E2BIG; 446 goto exit_unlock; 447 } 448 449 err = nsim_map_alloc_elem(offmap, idx); 450 if (err) 451 goto exit_unlock; 452 } 453 454 memcpy(nmap->entry[idx].key, key, offmap->map.key_size); 455 memcpy(nmap->entry[idx].value, value, offmap->map.value_size); 456 exit_unlock: 457 mutex_unlock(&nmap->mutex); 458 459 return err; 460 } 461 462 static int nsim_map_delete_elem(struct bpf_offloaded_map *offmap, void *key) 463 { 464 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 465 int idx; 466 467 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) 468 return -EINVAL; 469 470 mutex_lock(&nmap->mutex); 471 472 idx = nsim_map_key_find(offmap, key); 473 if (idx >= 0) { 474 kfree(nmap->entry[idx].key); 475 kfree(nmap->entry[idx].value); 476 memset(&nmap->entry[idx], 0, sizeof(nmap->entry[idx])); 477 } 478 479 mutex_unlock(&nmap->mutex); 480 481 return idx < 0 ? idx : 0; 482 } 483 484 static const struct bpf_map_dev_ops nsim_bpf_map_ops = { 485 .map_get_next_key = nsim_map_get_next_key, 486 .map_lookup_elem = nsim_map_lookup_elem, 487 .map_update_elem = nsim_map_update_elem, 488 .map_delete_elem = nsim_map_delete_elem, 489 }; 490 491 static int 492 nsim_bpf_map_alloc(struct netdevsim *ns, struct bpf_offloaded_map *offmap) 493 { 494 struct nsim_bpf_bound_map *nmap; 495 int i, err; 496 497 if (WARN_ON(offmap->map.map_type != BPF_MAP_TYPE_ARRAY && 498 offmap->map.map_type != BPF_MAP_TYPE_HASH)) 499 return -EINVAL; 500 if (offmap->map.max_entries > NSIM_BPF_MAX_KEYS) 501 return -ENOMEM; 502 if (offmap->map.map_flags) 503 return -EINVAL; 504 505 nmap = kzalloc(sizeof(*nmap), GFP_USER); 506 if (!nmap) 507 return -ENOMEM; 508 509 offmap->dev_priv = nmap; 510 nmap->ns = ns; 511 nmap->map = offmap; 512 mutex_init(&nmap->mutex); 513 514 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) { 515 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) { 516 u32 *key; 517 518 err = nsim_map_alloc_elem(offmap, i); 519 if (err) 520 goto err_free; 521 key = nmap->entry[i].key; 522 *key = i; 523 } 524 } 525 526 offmap->dev_ops = &nsim_bpf_map_ops; 527 list_add_tail(&nmap->l, &ns->sdev->bpf_bound_maps); 528 529 return 0; 530 531 err_free: 532 while (--i >= 0) { 533 kfree(nmap->entry[i].key); 534 kfree(nmap->entry[i].value); 535 } 536 kfree(nmap); 537 return err; 538 } 539 540 static void nsim_bpf_map_free(struct bpf_offloaded_map *offmap) 541 { 542 struct nsim_bpf_bound_map *nmap = offmap->dev_priv; 543 unsigned int i; 544 545 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) { 546 kfree(nmap->entry[i].key); 547 kfree(nmap->entry[i].value); 548 } 549 list_del_init(&nmap->l); 550 mutex_destroy(&nmap->mutex); 551 kfree(nmap); 552 } 553 554 int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf) 555 { 556 struct netdevsim *ns = netdev_priv(dev); 557 int err; 558 559 ASSERT_RTNL(); 560 561 switch (bpf->command) { 562 case XDP_QUERY_PROG: 563 return xdp_attachment_query(&ns->xdp, bpf); 564 case XDP_QUERY_PROG_HW: 565 return xdp_attachment_query(&ns->xdp_hw, bpf); 566 case XDP_SETUP_PROG: 567 err = nsim_setup_prog_checks(ns, bpf); 568 if (err) 569 return err; 570 571 return nsim_xdp_set_prog(ns, bpf, &ns->xdp); 572 case XDP_SETUP_PROG_HW: 573 err = nsim_setup_prog_hw_checks(ns, bpf); 574 if (err) 575 return err; 576 577 return nsim_xdp_set_prog(ns, bpf, &ns->xdp_hw); 578 case BPF_OFFLOAD_MAP_ALLOC: 579 if (!ns->bpf_map_accept) 580 return -EOPNOTSUPP; 581 582 return nsim_bpf_map_alloc(ns, bpf->offmap); 583 case BPF_OFFLOAD_MAP_FREE: 584 nsim_bpf_map_free(bpf->offmap); 585 return 0; 586 default: 587 return -EINVAL; 588 } 589 } 590 591 int nsim_bpf_init(struct netdevsim *ns) 592 { 593 int err; 594 595 if (ns->sdev->refcnt == 1) { 596 INIT_LIST_HEAD(&ns->sdev->bpf_bound_progs); 597 INIT_LIST_HEAD(&ns->sdev->bpf_bound_maps); 598 599 ns->sdev->ddir_bpf_bound_progs = 600 debugfs_create_dir("bpf_bound_progs", ns->sdev->ddir); 601 if (IS_ERR_OR_NULL(ns->sdev->ddir_bpf_bound_progs)) 602 return -ENOMEM; 603 604 ns->sdev->bpf_dev = bpf_offload_dev_create(&nsim_bpf_dev_ops); 605 err = PTR_ERR_OR_ZERO(ns->sdev->bpf_dev); 606 if (err) 607 return err; 608 } 609 610 err = bpf_offload_dev_netdev_register(ns->sdev->bpf_dev, ns->netdev); 611 if (err) 612 goto err_destroy_bdev; 613 614 debugfs_create_u32("bpf_offloaded_id", 0400, ns->ddir, 615 &ns->bpf_offloaded_id); 616 617 ns->bpf_bind_accept = true; 618 debugfs_create_bool("bpf_bind_accept", 0600, ns->ddir, 619 &ns->bpf_bind_accept); 620 debugfs_create_u32("bpf_bind_verifier_delay", 0600, ns->ddir, 621 &ns->bpf_bind_verifier_delay); 622 623 ns->bpf_tc_accept = true; 624 debugfs_create_bool("bpf_tc_accept", 0600, ns->ddir, 625 &ns->bpf_tc_accept); 626 debugfs_create_bool("bpf_tc_non_bound_accept", 0600, ns->ddir, 627 &ns->bpf_tc_non_bound_accept); 628 ns->bpf_xdpdrv_accept = true; 629 debugfs_create_bool("bpf_xdpdrv_accept", 0600, ns->ddir, 630 &ns->bpf_xdpdrv_accept); 631 ns->bpf_xdpoffload_accept = true; 632 debugfs_create_bool("bpf_xdpoffload_accept", 0600, ns->ddir, 633 &ns->bpf_xdpoffload_accept); 634 635 ns->bpf_map_accept = true; 636 debugfs_create_bool("bpf_map_accept", 0600, ns->ddir, 637 &ns->bpf_map_accept); 638 639 return 0; 640 641 err_destroy_bdev: 642 if (ns->sdev->refcnt == 1) 643 bpf_offload_dev_destroy(ns->sdev->bpf_dev); 644 return err; 645 } 646 647 void nsim_bpf_uninit(struct netdevsim *ns) 648 { 649 WARN_ON(ns->xdp.prog); 650 WARN_ON(ns->xdp_hw.prog); 651 WARN_ON(ns->bpf_offloaded); 652 bpf_offload_dev_netdev_unregister(ns->sdev->bpf_dev, ns->netdev); 653 654 if (ns->sdev->refcnt == 1) { 655 WARN_ON(!list_empty(&ns->sdev->bpf_bound_progs)); 656 WARN_ON(!list_empty(&ns->sdev->bpf_bound_maps)); 657 bpf_offload_dev_destroy(ns->sdev->bpf_dev); 658 } 659 } 660