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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 this6 * 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 FITNESS11 * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE12 * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME13 * 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 29struct 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 239 40struct 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 51static 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}60DEFINE_SHOW_ATTRIBUTE(nsim_bpf_string);61 62static int63nsim_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 82static int nsim_bpf_finalize(struct bpf_verifier_env *env)83{84 return 0;85}86 87static bool nsim_xdp_offload_active(struct netdevsim *ns)88{89 return ns->xdp_hw.prog;90}91 92static void nsim_prog_set_loaded(struct bpf_prog *prog, bool loaded)93{94 struct nsim_bpf_bound_prog *state;95 96 if (!prog || !bpf_prog_is_offloaded(prog->aux))97 return;98 99 state = prog->aux->offload->dev_priv;100 state->is_loaded = loaded;101}102 103static int104nsim_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 118int 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 173int 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 180static 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 192static int193nsim_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 218static 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 254static 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 265static 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 273static 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 285static 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 293static 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 306static int307nsim_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_is_offloaded(bpf->prog->aux)) {315 NSIM_EA(bpf->extack, "xdpoffload of non-bound program");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 327static bool328nsim_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 333static 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 345static int346nsim_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,351 GFP_KERNEL_ACCOUNT | __GFP_NOWARN);352 if (!nmap->entry[idx].key)353 return -ENOMEM;354 nmap->entry[idx].value = kmalloc(offmap->map.value_size,355 GFP_KERNEL_ACCOUNT | __GFP_NOWARN);356 if (!nmap->entry[idx].value) {357 kfree(nmap->entry[idx].key);358 nmap->entry[idx].key = NULL;359 return -ENOMEM;360 }361 362 return 0;363}364 365static int366nsim_map_get_next_key(struct bpf_offloaded_map *offmap,367 void *key, void *next_key)368{369 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;370 int idx = -ENOENT;371 372 mutex_lock(&nmap->mutex);373 374 if (key)375 idx = nsim_map_key_find(offmap, key);376 if (idx == -ENOENT)377 idx = 0;378 else379 idx++;380 381 for (; idx < ARRAY_SIZE(nmap->entry); idx++) {382 if (nmap->entry[idx].key) {383 memcpy(next_key, nmap->entry[idx].key,384 offmap->map.key_size);385 break;386 }387 }388 389 mutex_unlock(&nmap->mutex);390 391 if (idx == ARRAY_SIZE(nmap->entry))392 return -ENOENT;393 return 0;394}395 396static int397nsim_map_lookup_elem(struct bpf_offloaded_map *offmap, void *key, void *value)398{399 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;400 int idx;401 402 mutex_lock(&nmap->mutex);403 404 idx = nsim_map_key_find(offmap, key);405 if (idx >= 0)406 memcpy(value, nmap->entry[idx].value, offmap->map.value_size);407 408 mutex_unlock(&nmap->mutex);409 410 return idx < 0 ? idx : 0;411}412 413static int414nsim_map_update_elem(struct bpf_offloaded_map *offmap,415 void *key, void *value, u64 flags)416{417 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;418 int idx, err = 0;419 420 mutex_lock(&nmap->mutex);421 422 idx = nsim_map_key_find(offmap, key);423 if (idx < 0 && flags == BPF_EXIST) {424 err = idx;425 goto exit_unlock;426 }427 if (idx >= 0 && flags == BPF_NOEXIST) {428 err = -EEXIST;429 goto exit_unlock;430 }431 432 if (idx < 0) {433 for (idx = 0; idx < ARRAY_SIZE(nmap->entry); idx++)434 if (!nmap->entry[idx].key)435 break;436 if (idx == ARRAY_SIZE(nmap->entry)) {437 err = -E2BIG;438 goto exit_unlock;439 }440 441 err = nsim_map_alloc_elem(offmap, idx);442 if (err)443 goto exit_unlock;444 }445 446 memcpy(nmap->entry[idx].key, key, offmap->map.key_size);447 memcpy(nmap->entry[idx].value, value, offmap->map.value_size);448exit_unlock:449 mutex_unlock(&nmap->mutex);450 451 return err;452}453 454static int nsim_map_delete_elem(struct bpf_offloaded_map *offmap, void *key)455{456 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;457 int idx;458 459 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY)460 return -EINVAL;461 462 mutex_lock(&nmap->mutex);463 464 idx = nsim_map_key_find(offmap, key);465 if (idx >= 0) {466 kfree(nmap->entry[idx].key);467 kfree(nmap->entry[idx].value);468 memset(&nmap->entry[idx], 0, sizeof(nmap->entry[idx]));469 }470 471 mutex_unlock(&nmap->mutex);472 473 return idx < 0 ? idx : 0;474}475 476static const struct bpf_map_dev_ops nsim_bpf_map_ops = {477 .map_get_next_key = nsim_map_get_next_key,478 .map_lookup_elem = nsim_map_lookup_elem,479 .map_update_elem = nsim_map_update_elem,480 .map_delete_elem = nsim_map_delete_elem,481};482 483static int484nsim_bpf_map_alloc(struct netdevsim *ns, struct bpf_offloaded_map *offmap)485{486 struct nsim_bpf_bound_map *nmap;487 int i, err;488 489 if (WARN_ON(offmap->map.map_type != BPF_MAP_TYPE_ARRAY &&490 offmap->map.map_type != BPF_MAP_TYPE_HASH))491 return -EINVAL;492 if (offmap->map.max_entries > NSIM_BPF_MAX_KEYS)493 return -ENOMEM;494 if (offmap->map.map_flags)495 return -EINVAL;496 497 nmap = kzalloc(sizeof(*nmap), GFP_KERNEL_ACCOUNT);498 if (!nmap)499 return -ENOMEM;500 501 offmap->dev_priv = nmap;502 nmap->ns = ns;503 nmap->map = offmap;504 mutex_init(&nmap->mutex);505 506 if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) {507 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) {508 u32 *key;509 510 err = nsim_map_alloc_elem(offmap, i);511 if (err)512 goto err_free;513 key = nmap->entry[i].key;514 *key = i;515 memset(nmap->entry[i].value, 0, offmap->map.value_size);516 }517 }518 519 offmap->dev_ops = &nsim_bpf_map_ops;520 list_add_tail(&nmap->l, &ns->nsim_dev->bpf_bound_maps);521 522 return 0;523 524err_free:525 while (--i >= 0) {526 kfree(nmap->entry[i].key);527 kfree(nmap->entry[i].value);528 }529 kfree(nmap);530 return err;531}532 533static void nsim_bpf_map_free(struct bpf_offloaded_map *offmap)534{535 struct nsim_bpf_bound_map *nmap = offmap->dev_priv;536 unsigned int i;537 538 for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) {539 kfree(nmap->entry[i].key);540 kfree(nmap->entry[i].value);541 }542 list_del_init(&nmap->l);543 mutex_destroy(&nmap->mutex);544 kfree(nmap);545}546 547int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf)548{549 struct netdevsim *ns = netdev_priv(dev);550 int err;551 552 ASSERT_RTNL();553 554 switch (bpf->command) {555 case XDP_SETUP_PROG:556 err = nsim_setup_prog_checks(ns, bpf);557 if (err)558 return err;559 560 return nsim_xdp_set_prog(ns, bpf, &ns->xdp);561 case XDP_SETUP_PROG_HW:562 err = nsim_setup_prog_hw_checks(ns, bpf);563 if (err)564 return err;565 566 return nsim_xdp_set_prog(ns, bpf, &ns->xdp_hw);567 case BPF_OFFLOAD_MAP_ALLOC:568 if (!ns->bpf_map_accept)569 return -EOPNOTSUPP;570 571 return nsim_bpf_map_alloc(ns, bpf->offmap);572 case BPF_OFFLOAD_MAP_FREE:573 nsim_bpf_map_free(bpf->offmap);574 return 0;575 default:576 return -EINVAL;577 }578}579 580int nsim_bpf_dev_init(struct nsim_dev *nsim_dev)581{582 int err;583 584 INIT_LIST_HEAD(&nsim_dev->bpf_bound_progs);585 INIT_LIST_HEAD(&nsim_dev->bpf_bound_maps);586 587 nsim_dev->ddir_bpf_bound_progs = debugfs_create_dir("bpf_bound_progs",588 nsim_dev->ddir);589 if (IS_ERR(nsim_dev->ddir_bpf_bound_progs))590 return PTR_ERR(nsim_dev->ddir_bpf_bound_progs);591 592 nsim_dev->bpf_dev = bpf_offload_dev_create(&nsim_bpf_dev_ops, nsim_dev);593 err = PTR_ERR_OR_ZERO(nsim_dev->bpf_dev);594 if (err)595 return err;596 597 nsim_dev->bpf_bind_accept = true;598 debugfs_create_bool("bpf_bind_accept", 0600, nsim_dev->ddir,599 &nsim_dev->bpf_bind_accept);600 debugfs_create_u32("bpf_bind_verifier_delay", 0600, nsim_dev->ddir,601 &nsim_dev->bpf_bind_verifier_delay);602 nsim_dev->bpf_bind_verifier_accept = true;603 debugfs_create_bool("bpf_bind_verifier_accept", 0600, nsim_dev->ddir,604 &nsim_dev->bpf_bind_verifier_accept);605 return 0;606}607 608void nsim_bpf_dev_exit(struct nsim_dev *nsim_dev)609{610 WARN_ON(!list_empty(&nsim_dev->bpf_bound_progs));611 WARN_ON(!list_empty(&nsim_dev->bpf_bound_maps));612 bpf_offload_dev_destroy(nsim_dev->bpf_dev);613}614 615int nsim_bpf_init(struct netdevsim *ns)616{617 struct dentry *ddir = ns->nsim_dev_port->ddir;618 int err;619 620 err = bpf_offload_dev_netdev_register(ns->nsim_dev->bpf_dev,621 ns->netdev);622 if (err)623 return err;624 625 debugfs_create_u32("bpf_offloaded_id", 0400, ddir,626 &ns->bpf_offloaded_id);627 628 ns->bpf_tc_accept = true;629 debugfs_create_bool("bpf_tc_accept", 0600, ddir,630 &ns->bpf_tc_accept);631 debugfs_create_bool("bpf_tc_non_bound_accept", 0600, ddir,632 &ns->bpf_tc_non_bound_accept);633 ns->bpf_xdpdrv_accept = true;634 debugfs_create_bool("bpf_xdpdrv_accept", 0600, ddir,635 &ns->bpf_xdpdrv_accept);636 ns->bpf_xdpoffload_accept = true;637 debugfs_create_bool("bpf_xdpoffload_accept", 0600, ddir,638 &ns->bpf_xdpoffload_accept);639 640 ns->bpf_map_accept = true;641 debugfs_create_bool("bpf_map_accept", 0600, ddir,642 &ns->bpf_map_accept);643 644 return 0;645}646 647void 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->nsim_dev->bpf_dev, ns->netdev);653}654