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