1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Functions to manage eBPF programs attached to cgroups
   4 *
   5 * Copyright (c) 2016 Daniel Mack
   6 */
   7
   8#include <linux/kernel.h>
   9#include <linux/atomic.h>
  10#include <linux/cgroup.h>
  11#include <linux/filter.h>
  12#include <linux/slab.h>
  13#include <linux/sysctl.h>
  14#include <linux/string.h>
  15#include <linux/bpf.h>
  16#include <linux/bpf-cgroup.h>
  17#include <linux/bpf_lsm.h>
  18#include <linux/bpf_verifier.h>
  19#include <net/sock.h>
  20#include <net/bpf_sk_storage.h>
  21
  22#include "../cgroup/cgroup-internal.h"
  23
  24DEFINE_STATIC_KEY_ARRAY_FALSE(cgroup_bpf_enabled_key, MAX_CGROUP_BPF_ATTACH_TYPE);
  25EXPORT_SYMBOL(cgroup_bpf_enabled_key);
  26
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  27/* __always_inline is necessary to prevent indirect call through run_prog
  28 * function pointer.
  29 */
  30static __always_inline int
  31bpf_prog_run_array_cg(const struct cgroup_bpf *cgrp,
  32		      enum cgroup_bpf_attach_type atype,
  33		      const void *ctx, bpf_prog_run_fn run_prog,
  34		      int retval, u32 *ret_flags)
  35{
  36	const struct bpf_prog_array_item *item;
  37	const struct bpf_prog *prog;
  38	const struct bpf_prog_array *array;
  39	struct bpf_run_ctx *old_run_ctx;
  40	struct bpf_cg_run_ctx run_ctx;
  41	u32 func_ret;
  42
  43	run_ctx.retval = retval;
  44	migrate_disable();
  45	rcu_read_lock();
  46	array = rcu_dereference(cgrp->effective[atype]);
  47	item = &array->items[0];
  48	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
  49	while ((prog = READ_ONCE(item->prog))) {
  50		run_ctx.prog_item = item;
  51		func_ret = run_prog(prog, ctx);
  52		if (ret_flags) {
  53			*(ret_flags) |= (func_ret >> 1);
  54			func_ret &= 1;
  55		}
  56		if (!func_ret && !IS_ERR_VALUE((long)run_ctx.retval))
  57			run_ctx.retval = -EPERM;
  58		item++;
  59	}
  60	bpf_reset_run_ctx(old_run_ctx);
  61	rcu_read_unlock();
  62	migrate_enable();
  63	return run_ctx.retval;
  64}
  65
  66unsigned int __cgroup_bpf_run_lsm_sock(const void *ctx,
  67				       const struct bpf_insn *insn)
  68{
  69	const struct bpf_prog *shim_prog;
  70	struct sock *sk;
  71	struct cgroup *cgrp;
  72	int ret = 0;
  73	u64 *args;
  74
  75	args = (u64 *)ctx;
  76	sk = (void *)(unsigned long)args[0];
  77	/*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/
  78	shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi));
  79
  80	cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
  81	if (likely(cgrp))
  82		ret = bpf_prog_run_array_cg(&cgrp->bpf,
  83					    shim_prog->aux->cgroup_atype,
  84					    ctx, bpf_prog_run, 0, NULL);
  85	return ret;
  86}
  87
  88unsigned int __cgroup_bpf_run_lsm_socket(const void *ctx,
  89					 const struct bpf_insn *insn)
  90{
  91	const struct bpf_prog *shim_prog;
  92	struct socket *sock;
  93	struct cgroup *cgrp;
  94	int ret = 0;
  95	u64 *args;
  96
  97	args = (u64 *)ctx;
  98	sock = (void *)(unsigned long)args[0];
  99	/*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/
 100	shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi));
 101
 102	cgrp = sock_cgroup_ptr(&sock->sk->sk_cgrp_data);
 103	if (likely(cgrp))
 104		ret = bpf_prog_run_array_cg(&cgrp->bpf,
 105					    shim_prog->aux->cgroup_atype,
 106					    ctx, bpf_prog_run, 0, NULL);
 107	return ret;
 108}
 109
 110unsigned int __cgroup_bpf_run_lsm_current(const void *ctx,
 111					  const struct bpf_insn *insn)
 112{
 113	const struct bpf_prog *shim_prog;
 114	struct cgroup *cgrp;
 115	int ret = 0;
 116
 117	/*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/
 118	shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi));
 119
 120	/* We rely on trampoline's __bpf_prog_enter_lsm_cgroup to grab RCU read lock. */
 121	cgrp = task_dfl_cgroup(current);
 122	if (likely(cgrp))
 123		ret = bpf_prog_run_array_cg(&cgrp->bpf,
 124					    shim_prog->aux->cgroup_atype,
 125					    ctx, bpf_prog_run, 0, NULL);
 126	return ret;
 127}
 128
 129#ifdef CONFIG_BPF_LSM
 130struct cgroup_lsm_atype {
 131	u32 attach_btf_id;
 132	int refcnt;
 133};
 134
 135static struct cgroup_lsm_atype cgroup_lsm_atype[CGROUP_LSM_NUM];
 136
 137static enum cgroup_bpf_attach_type
 138bpf_cgroup_atype_find(enum bpf_attach_type attach_type, u32 attach_btf_id)
 139{
 140	int i;
 141
 142	lockdep_assert_held(&cgroup_mutex);
 143
 144	if (attach_type != BPF_LSM_CGROUP)
 145		return to_cgroup_bpf_attach_type(attach_type);
 146
 147	for (i = 0; i < ARRAY_SIZE(cgroup_lsm_atype); i++)
 148		if (cgroup_lsm_atype[i].attach_btf_id == attach_btf_id)
 149			return CGROUP_LSM_START + i;
 150
 151	for (i = 0; i < ARRAY_SIZE(cgroup_lsm_atype); i++)
 152		if (cgroup_lsm_atype[i].attach_btf_id == 0)
 153			return CGROUP_LSM_START + i;
 154
 155	return -E2BIG;
 156
 157}
 158
 159void bpf_cgroup_atype_get(u32 attach_btf_id, int cgroup_atype)
 160{
 161	int i = cgroup_atype - CGROUP_LSM_START;
 162
 163	lockdep_assert_held(&cgroup_mutex);
 164
 165	WARN_ON_ONCE(cgroup_lsm_atype[i].attach_btf_id &&
 166		     cgroup_lsm_atype[i].attach_btf_id != attach_btf_id);
 167
 168	cgroup_lsm_atype[i].attach_btf_id = attach_btf_id;
 169	cgroup_lsm_atype[i].refcnt++;
 170}
 171
 172void bpf_cgroup_atype_put(int cgroup_atype)
 173{
 174	int i = cgroup_atype - CGROUP_LSM_START;
 175
 176	cgroup_lock();
 177	if (--cgroup_lsm_atype[i].refcnt <= 0)
 178		cgroup_lsm_atype[i].attach_btf_id = 0;
 179	WARN_ON_ONCE(cgroup_lsm_atype[i].refcnt < 0);
 180	cgroup_unlock();
 181}
 182#else
 183static enum cgroup_bpf_attach_type
 184bpf_cgroup_atype_find(enum bpf_attach_type attach_type, u32 attach_btf_id)
 185{
 186	if (attach_type != BPF_LSM_CGROUP)
 187		return to_cgroup_bpf_attach_type(attach_type);
 188	return -EOPNOTSUPP;
 189}
 190#endif /* CONFIG_BPF_LSM */
 191
 192void cgroup_bpf_offline(struct cgroup *cgrp)
 193{
 194	cgroup_get(cgrp);
 195	percpu_ref_kill(&cgrp->bpf.refcnt);
 196}
 197
 198static void bpf_cgroup_storages_free(struct bpf_cgroup_storage *storages[])
 199{
 200	enum bpf_cgroup_storage_type stype;
 201
 202	for_each_cgroup_storage_type(stype)
 203		bpf_cgroup_storage_free(storages[stype]);
 204}
 205
 206static int bpf_cgroup_storages_alloc(struct bpf_cgroup_storage *storages[],
 207				     struct bpf_cgroup_storage *new_storages[],
 208				     enum bpf_attach_type type,
 209				     struct bpf_prog *prog,
 210				     struct cgroup *cgrp)
 211{
 212	enum bpf_cgroup_storage_type stype;
 213	struct bpf_cgroup_storage_key key;
 214	struct bpf_map *map;
 215
 216	key.cgroup_inode_id = cgroup_id(cgrp);
 217	key.attach_type = type;
 218
 219	for_each_cgroup_storage_type(stype) {
 220		map = prog->aux->cgroup_storage[stype];
 221		if (!map)
 222			continue;
 223
 224		storages[stype] = cgroup_storage_lookup((void *)map, &key, false);
 225		if (storages[stype])
 226			continue;
 227
 228		storages[stype] = bpf_cgroup_storage_alloc(prog, stype);
 229		if (IS_ERR(storages[stype])) {
 230			bpf_cgroup_storages_free(new_storages);
 231			return -ENOMEM;
 232		}
 233
 234		new_storages[stype] = storages[stype];
 235	}
 236
 237	return 0;
 238}
 239
 240static void bpf_cgroup_storages_assign(struct bpf_cgroup_storage *dst[],
 241				       struct bpf_cgroup_storage *src[])
 242{
 243	enum bpf_cgroup_storage_type stype;
 244
 245	for_each_cgroup_storage_type(stype)
 246		dst[stype] = src[stype];
 247}
 248
 249static void bpf_cgroup_storages_link(struct bpf_cgroup_storage *storages[],
 250				     struct cgroup *cgrp,
 251				     enum bpf_attach_type attach_type)
 252{
 253	enum bpf_cgroup_storage_type stype;
 254
 255	for_each_cgroup_storage_type(stype)
 256		bpf_cgroup_storage_link(storages[stype], cgrp, attach_type);
 257}
 258
 259/* Called when bpf_cgroup_link is auto-detached from dying cgroup.
 260 * It drops cgroup and bpf_prog refcounts, and marks bpf_link as defunct. It
 261 * doesn't free link memory, which will eventually be done by bpf_link's
 262 * release() callback, when its last FD is closed.
 263 */
 264static void bpf_cgroup_link_auto_detach(struct bpf_cgroup_link *link)
 265{
 266	cgroup_put(link->cgroup);
 267	link->cgroup = NULL;
 268}
 269
 270/**
 271 * cgroup_bpf_release() - put references of all bpf programs and
 272 *                        release all cgroup bpf data
 273 * @work: work structure embedded into the cgroup to modify
 274 */
 275static void cgroup_bpf_release(struct work_struct *work)
 276{
 277	struct cgroup *p, *cgrp = container_of(work, struct cgroup,
 278					       bpf.release_work);
 279	struct bpf_prog_array *old_array;
 280	struct list_head *storages = &cgrp->bpf.storages;
 281	struct bpf_cgroup_storage *storage, *stmp;
 282
 283	unsigned int atype;
 284
 285	cgroup_lock();
 286
 287	for (atype = 0; atype < ARRAY_SIZE(cgrp->bpf.progs); atype++) {
 288		struct hlist_head *progs = &cgrp->bpf.progs[atype];
 289		struct bpf_prog_list *pl;
 290		struct hlist_node *pltmp;
 291
 292		hlist_for_each_entry_safe(pl, pltmp, progs, node) {
 293			hlist_del(&pl->node);
 294			if (pl->prog) {
 295				if (pl->prog->expected_attach_type == BPF_LSM_CGROUP)
 296					bpf_trampoline_unlink_cgroup_shim(pl->prog);
 297				bpf_prog_put(pl->prog);
 298			}
 299			if (pl->link) {
 300				if (pl->link->link.prog->expected_attach_type == BPF_LSM_CGROUP)
 301					bpf_trampoline_unlink_cgroup_shim(pl->link->link.prog);
 302				bpf_cgroup_link_auto_detach(pl->link);
 303			}
 304			kfree(pl);
 305			static_branch_dec(&cgroup_bpf_enabled_key[atype]);
 306		}
 307		old_array = rcu_dereference_protected(
 308				cgrp->bpf.effective[atype],
 309				lockdep_is_held(&cgroup_mutex));
 310		bpf_prog_array_free(old_array);
 311	}
 312
 313	list_for_each_entry_safe(storage, stmp, storages, list_cg) {
 314		bpf_cgroup_storage_unlink(storage);
 315		bpf_cgroup_storage_free(storage);
 316	}
 317
 318	cgroup_unlock();
 319
 320	for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
 321		cgroup_bpf_put(p);
 322
 323	percpu_ref_exit(&cgrp->bpf.refcnt);
 324	cgroup_put(cgrp);
 325}
 326
 327/**
 328 * cgroup_bpf_release_fn() - callback used to schedule releasing
 329 *                           of bpf cgroup data
 330 * @ref: percpu ref counter structure
 331 */
 332static void cgroup_bpf_release_fn(struct percpu_ref *ref)
 333{
 334	struct cgroup *cgrp = container_of(ref, struct cgroup, bpf.refcnt);
 335
 336	INIT_WORK(&cgrp->bpf.release_work, cgroup_bpf_release);
 337	queue_work(system_wq, &cgrp->bpf.release_work);
 338}
 339
 340/* Get underlying bpf_prog of bpf_prog_list entry, regardless if it's through
 341 * link or direct prog.
 342 */
 343static struct bpf_prog *prog_list_prog(struct bpf_prog_list *pl)
 344{
 345	if (pl->prog)
 346		return pl->prog;
 347	if (pl->link)
 348		return pl->link->link.prog;
 349	return NULL;
 350}
 351
 352/* count number of elements in the list.
 353 * it's slow but the list cannot be long
 354 */
 355static u32 prog_list_length(struct hlist_head *head)
 356{
 357	struct bpf_prog_list *pl;
 358	u32 cnt = 0;
 359
 360	hlist_for_each_entry(pl, head, node) {
 361		if (!prog_list_prog(pl))
 362			continue;
 363		cnt++;
 364	}
 365	return cnt;
 366}
 367
 368/* if parent has non-overridable prog attached,
 369 * disallow attaching new programs to the descendent cgroup.
 370 * if parent has overridable or multi-prog, allow attaching
 371 */
 372static bool hierarchy_allows_attach(struct cgroup *cgrp,
 373				    enum cgroup_bpf_attach_type atype)
 374{
 375	struct cgroup *p;
 376
 377	p = cgroup_parent(cgrp);
 378	if (!p)
 379		return true;
 380	do {
 381		u32 flags = p->bpf.flags[atype];
 382		u32 cnt;
 383
 384		if (flags & BPF_F_ALLOW_MULTI)
 385			return true;
 386		cnt = prog_list_length(&p->bpf.progs[atype]);
 387		WARN_ON_ONCE(cnt > 1);
 388		if (cnt == 1)
 389			return !!(flags & BPF_F_ALLOW_OVERRIDE);
 390		p = cgroup_parent(p);
 391	} while (p);
 392	return true;
 393}
 394
 395/* compute a chain of effective programs for a given cgroup:
 396 * start from the list of programs in this cgroup and add
 397 * all parent programs.
 398 * Note that parent's F_ALLOW_OVERRIDE-type program is yielding
 399 * to programs in this cgroup
 400 */
 401static int compute_effective_progs(struct cgroup *cgrp,
 402				   enum cgroup_bpf_attach_type atype,
 403				   struct bpf_prog_array **array)
 404{
 405	struct bpf_prog_array_item *item;
 406	struct bpf_prog_array *progs;
 407	struct bpf_prog_list *pl;
 408	struct cgroup *p = cgrp;
 409	int cnt = 0;
 410
 411	/* count number of effective programs by walking parents */
 412	do {
 413		if (cnt == 0 || (p->bpf.flags[atype] & BPF_F_ALLOW_MULTI))
 414			cnt += prog_list_length(&p->bpf.progs[atype]);
 415		p = cgroup_parent(p);
 416	} while (p);
 417
 418	progs = bpf_prog_array_alloc(cnt, GFP_KERNEL);
 419	if (!progs)
 420		return -ENOMEM;
 421
 422	/* populate the array with effective progs */
 423	cnt = 0;
 424	p = cgrp;
 425	do {
 426		if (cnt > 0 && !(p->bpf.flags[atype] & BPF_F_ALLOW_MULTI))
 427			continue;
 428
 429		hlist_for_each_entry(pl, &p->bpf.progs[atype], node) {
 430			if (!prog_list_prog(pl))
 431				continue;
 432
 433			item = &progs->items[cnt];
 434			item->prog = prog_list_prog(pl);
 435			bpf_cgroup_storages_assign(item->cgroup_storage,
 436						   pl->storage);
 437			cnt++;
 438		}
 439	} while ((p = cgroup_parent(p)));
 440
 441	*array = progs;
 442	return 0;
 443}
 444
 445static void activate_effective_progs(struct cgroup *cgrp,
 446				     enum cgroup_bpf_attach_type atype,
 447				     struct bpf_prog_array *old_array)
 448{
 449	old_array = rcu_replace_pointer(cgrp->bpf.effective[atype], old_array,
 450					lockdep_is_held(&cgroup_mutex));
 451	/* free prog array after grace period, since __cgroup_bpf_run_*()
 452	 * might be still walking the array
 453	 */
 454	bpf_prog_array_free(old_array);
 455}
 456
 457/**
 458 * cgroup_bpf_inherit() - inherit effective programs from parent
 459 * @cgrp: the cgroup to modify
 460 */
 461int cgroup_bpf_inherit(struct cgroup *cgrp)
 462{
 463/* has to use marco instead of const int, since compiler thinks
 464 * that array below is variable length
 465 */
 466#define	NR ARRAY_SIZE(cgrp->bpf.effective)
 467	struct bpf_prog_array *arrays[NR] = {};
 468	struct cgroup *p;
 469	int ret, i;
 470
 471	ret = percpu_ref_init(&cgrp->bpf.refcnt, cgroup_bpf_release_fn, 0,
 472			      GFP_KERNEL);
 473	if (ret)
 474		return ret;
 475
 476	for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
 477		cgroup_bpf_get(p);
 478
 479	for (i = 0; i < NR; i++)
 480		INIT_HLIST_HEAD(&cgrp->bpf.progs[i]);
 481
 482	INIT_LIST_HEAD(&cgrp->bpf.storages);
 483
 484	for (i = 0; i < NR; i++)
 485		if (compute_effective_progs(cgrp, i, &arrays[i]))
 486			goto cleanup;
 487
 488	for (i = 0; i < NR; i++)
 489		activate_effective_progs(cgrp, i, arrays[i]);
 490
 491	return 0;
 492cleanup:
 493	for (i = 0; i < NR; i++)
 494		bpf_prog_array_free(arrays[i]);
 495
 496	for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
 497		cgroup_bpf_put(p);
 498
 499	percpu_ref_exit(&cgrp->bpf.refcnt);
 500
 501	return -ENOMEM;
 502}
 503
 504static int update_effective_progs(struct cgroup *cgrp,
 505				  enum cgroup_bpf_attach_type atype)
 506{
 507	struct cgroup_subsys_state *css;
 508	int err;
 509
 510	/* allocate and recompute effective prog arrays */
 511	css_for_each_descendant_pre(css, &cgrp->self) {
 512		struct cgroup *desc = container_of(css, struct cgroup, self);
 513
 514		if (percpu_ref_is_zero(&desc->bpf.refcnt))
 515			continue;
 516
 517		err = compute_effective_progs(desc, atype, &desc->bpf.inactive);
 518		if (err)
 519			goto cleanup;
 520	}
 521
 522	/* all allocations were successful. Activate all prog arrays */
 523	css_for_each_descendant_pre(css, &cgrp->self) {
 524		struct cgroup *desc = container_of(css, struct cgroup, self);
 525
 526		if (percpu_ref_is_zero(&desc->bpf.refcnt)) {
 527			if (unlikely(desc->bpf.inactive)) {
 528				bpf_prog_array_free(desc->bpf.inactive);
 529				desc->bpf.inactive = NULL;
 530			}
 531			continue;
 532		}
 533
 534		activate_effective_progs(desc, atype, desc->bpf.inactive);
 535		desc->bpf.inactive = NULL;
 536	}
 537
 538	return 0;
 539
 540cleanup:
 541	/* oom while computing effective. Free all computed effective arrays
 542	 * since they were not activated
 543	 */
 544	css_for_each_descendant_pre(css, &cgrp->self) {
 545		struct cgroup *desc = container_of(css, struct cgroup, self);
 546
 547		bpf_prog_array_free(desc->bpf.inactive);
 548		desc->bpf.inactive = NULL;
 549	}
 550
 551	return err;
 552}
 553
 554#define BPF_CGROUP_MAX_PROGS 64
 555
 556static struct bpf_prog_list *find_attach_entry(struct hlist_head *progs,
 557					       struct bpf_prog *prog,
 558					       struct bpf_cgroup_link *link,
 559					       struct bpf_prog *replace_prog,
 560					       bool allow_multi)
 561{
 562	struct bpf_prog_list *pl;
 563
 564	/* single-attach case */
 565	if (!allow_multi) {
 566		if (hlist_empty(progs))
 567			return NULL;
 568		return hlist_entry(progs->first, typeof(*pl), node);
 569	}
 570
 571	hlist_for_each_entry(pl, progs, node) {
 572		if (prog && pl->prog == prog && prog != replace_prog)
 573			/* disallow attaching the same prog twice */
 574			return ERR_PTR(-EINVAL);
 575		if (link && pl->link == link)
 576			/* disallow attaching the same link twice */
 577			return ERR_PTR(-EINVAL);
 578	}
 579
 580	/* direct prog multi-attach w/ replacement case */
 581	if (replace_prog) {
 582		hlist_for_each_entry(pl, progs, node) {
 583			if (pl->prog == replace_prog)
 584				/* a match found */
 585				return pl;
 586		}
 587		/* prog to replace not found for cgroup */
 588		return ERR_PTR(-ENOENT);
 589	}
 590
 591	return NULL;
 592}
 593
 594/**
 595 * __cgroup_bpf_attach() - Attach the program or the link to a cgroup, and
 596 *                         propagate the change to descendants
 597 * @cgrp: The cgroup which descendants to traverse
 598 * @prog: A program to attach
 599 * @link: A link to attach
 600 * @replace_prog: Previously attached program to replace if BPF_F_REPLACE is set
 601 * @type: Type of attach operation
 602 * @flags: Option flags
 603 *
 604 * Exactly one of @prog or @link can be non-null.
 605 * Must be called with cgroup_mutex held.
 606 */
 607static int __cgroup_bpf_attach(struct cgroup *cgrp,
 608			       struct bpf_prog *prog, struct bpf_prog *replace_prog,
 609			       struct bpf_cgroup_link *link,
 610			       enum bpf_attach_type type, u32 flags)
 611{
 612	u32 saved_flags = (flags & (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI));
 613	struct bpf_prog *old_prog = NULL;
 614	struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
 615	struct bpf_cgroup_storage *new_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
 616	struct bpf_prog *new_prog = prog ? : link->link.prog;
 617	enum cgroup_bpf_attach_type atype;
 618	struct bpf_prog_list *pl;
 619	struct hlist_head *progs;
 620	int err;
 621
 622	if (((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI)) ||
 623	    ((flags & BPF_F_REPLACE) && !(flags & BPF_F_ALLOW_MULTI)))
 624		/* invalid combination */
 625		return -EINVAL;
 626	if (link && (prog || replace_prog))
 627		/* only either link or prog/replace_prog can be specified */
 628		return -EINVAL;
 629	if (!!replace_prog != !!(flags & BPF_F_REPLACE))
 630		/* replace_prog implies BPF_F_REPLACE, and vice versa */
 631		return -EINVAL;
 632
 633	atype = bpf_cgroup_atype_find(type, new_prog->aux->attach_btf_id);
 634	if (atype < 0)
 635		return -EINVAL;
 636
 637	progs = &cgrp->bpf.progs[atype];
 638
 639	if (!hierarchy_allows_attach(cgrp, atype))
 640		return -EPERM;
 641
 642	if (!hlist_empty(progs) && cgrp->bpf.flags[atype] != saved_flags)
 643		/* Disallow attaching non-overridable on top
 644		 * of existing overridable in this cgroup.
 645		 * Disallow attaching multi-prog if overridable or none
 646		 */
 647		return -EPERM;
 648
 649	if (prog_list_length(progs) >= BPF_CGROUP_MAX_PROGS)
 650		return -E2BIG;
 651
 652	pl = find_attach_entry(progs, prog, link, replace_prog,
 653			       flags & BPF_F_ALLOW_MULTI);
 654	if (IS_ERR(pl))
 655		return PTR_ERR(pl);
 656
 657	if (bpf_cgroup_storages_alloc(storage, new_storage, type,
 658				      prog ? : link->link.prog, cgrp))
 659		return -ENOMEM;
 660
 661	if (pl) {
 662		old_prog = pl->prog;
 663	} else {
 664		struct hlist_node *last = NULL;
 665
 666		pl = kmalloc(sizeof(*pl), GFP_KERNEL);
 667		if (!pl) {
 668			bpf_cgroup_storages_free(new_storage);
 669			return -ENOMEM;
 670		}
 671		if (hlist_empty(progs))
 672			hlist_add_head(&pl->node, progs);
 673		else
 674			hlist_for_each(last, progs) {
 675				if (last->next)
 676					continue;
 677				hlist_add_behind(&pl->node, last);
 678				break;
 679			}
 680	}
 681
 682	pl->prog = prog;
 683	pl->link = link;
 684	bpf_cgroup_storages_assign(pl->storage, storage);
 685	cgrp->bpf.flags[atype] = saved_flags;
 686
 687	if (type == BPF_LSM_CGROUP) {
 688		err = bpf_trampoline_link_cgroup_shim(new_prog, atype);
 689		if (err)
 690			goto cleanup;
 691	}
 692
 693	err = update_effective_progs(cgrp, atype);
 694	if (err)
 695		goto cleanup_trampoline;
 696
 697	if (old_prog) {
 698		if (type == BPF_LSM_CGROUP)
 699			bpf_trampoline_unlink_cgroup_shim(old_prog);
 700		bpf_prog_put(old_prog);
 701	} else {
 702		static_branch_inc(&cgroup_bpf_enabled_key[atype]);
 703	}
 704	bpf_cgroup_storages_link(new_storage, cgrp, type);
 705	return 0;
 706
 707cleanup_trampoline:
 708	if (type == BPF_LSM_CGROUP)
 709		bpf_trampoline_unlink_cgroup_shim(new_prog);
 710
 711cleanup:
 712	if (old_prog) {
 713		pl->prog = old_prog;
 714		pl->link = NULL;
 715	}
 716	bpf_cgroup_storages_free(new_storage);
 717	if (!old_prog) {
 718		hlist_del(&pl->node);
 719		kfree(pl);
 720	}
 721	return err;
 722}
 723
 724static int cgroup_bpf_attach(struct cgroup *cgrp,
 725			     struct bpf_prog *prog, struct bpf_prog *replace_prog,
 726			     struct bpf_cgroup_link *link,
 727			     enum bpf_attach_type type,
 728			     u32 flags)
 729{
 730	int ret;
 731
 732	cgroup_lock();
 733	ret = __cgroup_bpf_attach(cgrp, prog, replace_prog, link, type, flags);
 734	cgroup_unlock();
 735	return ret;
 736}
 737
 738/* Swap updated BPF program for given link in effective program arrays across
 739 * all descendant cgroups. This function is guaranteed to succeed.
 740 */
 741static void replace_effective_prog(struct cgroup *cgrp,
 742				   enum cgroup_bpf_attach_type atype,
 743				   struct bpf_cgroup_link *link)
 744{
 745	struct bpf_prog_array_item *item;
 746	struct cgroup_subsys_state *css;
 747	struct bpf_prog_array *progs;
 748	struct bpf_prog_list *pl;
 749	struct hlist_head *head;
 750	struct cgroup *cg;
 751	int pos;
 752
 753	css_for_each_descendant_pre(css, &cgrp->self) {
 754		struct cgroup *desc = container_of(css, struct cgroup, self);
 755
 756		if (percpu_ref_is_zero(&desc->bpf.refcnt))
 757			continue;
 758
 759		/* find position of link in effective progs array */
 760		for (pos = 0, cg = desc; cg; cg = cgroup_parent(cg)) {
 761			if (pos && !(cg->bpf.flags[atype] & BPF_F_ALLOW_MULTI))
 762				continue;
 763
 764			head = &cg->bpf.progs[atype];
 765			hlist_for_each_entry(pl, head, node) {
 766				if (!prog_list_prog(pl))
 767					continue;
 768				if (pl->link == link)
 769					goto found;
 770				pos++;
 771			}
 772		}
 773found:
 774		BUG_ON(!cg);
 775		progs = rcu_dereference_protected(
 776				desc->bpf.effective[atype],
 777				lockdep_is_held(&cgroup_mutex));
 778		item = &progs->items[pos];
 779		WRITE_ONCE(item->prog, link->link.prog);
 780	}
 781}
 782
 783/**
 784 * __cgroup_bpf_replace() - Replace link's program and propagate the change
 785 *                          to descendants
 786 * @cgrp: The cgroup which descendants to traverse
 787 * @link: A link for which to replace BPF program
 788 * @new_prog: &struct bpf_prog for the target BPF program with its refcnt
 789 *            incremented
 790 *
 791 * Must be called with cgroup_mutex held.
 792 */
 793static int __cgroup_bpf_replace(struct cgroup *cgrp,
 794				struct bpf_cgroup_link *link,
 795				struct bpf_prog *new_prog)
 796{
 797	enum cgroup_bpf_attach_type atype;
 798	struct bpf_prog *old_prog;
 799	struct bpf_prog_list *pl;
 800	struct hlist_head *progs;
 801	bool found = false;
 802
 803	atype = bpf_cgroup_atype_find(link->type, new_prog->aux->attach_btf_id);
 804	if (atype < 0)
 805		return -EINVAL;
 806
 807	progs = &cgrp->bpf.progs[atype];
 808
 809	if (link->link.prog->type != new_prog->type)
 810		return -EINVAL;
 811
 812	hlist_for_each_entry(pl, progs, node) {
 813		if (pl->link == link) {
 814			found = true;
 815			break;
 816		}
 817	}
 818	if (!found)
 819		return -ENOENT;
 820
 821	old_prog = xchg(&link->link.prog, new_prog);
 822	replace_effective_prog(cgrp, atype, link);
 823	bpf_prog_put(old_prog);
 824	return 0;
 825}
 826
 827static int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *new_prog,
 828			      struct bpf_prog *old_prog)
 829{
 830	struct bpf_cgroup_link *cg_link;
 831	int ret;
 832
 833	cg_link = container_of(link, struct bpf_cgroup_link, link);
 834
 835	cgroup_lock();
 836	/* link might have been auto-released by dying cgroup, so fail */
 837	if (!cg_link->cgroup) {
 838		ret = -ENOLINK;
 839		goto out_unlock;
 840	}
 841	if (old_prog && link->prog != old_prog) {
 842		ret = -EPERM;
 843		goto out_unlock;
 844	}
 845	ret = __cgroup_bpf_replace(cg_link->cgroup, cg_link, new_prog);
 846out_unlock:
 847	cgroup_unlock();
 848	return ret;
 849}
 850
 851static struct bpf_prog_list *find_detach_entry(struct hlist_head *progs,
 852					       struct bpf_prog *prog,
 853					       struct bpf_cgroup_link *link,
 854					       bool allow_multi)
 855{
 856	struct bpf_prog_list *pl;
 857
 858	if (!allow_multi) {
 859		if (hlist_empty(progs))
 860			/* report error when trying to detach and nothing is attached */
 861			return ERR_PTR(-ENOENT);
 862
 863		/* to maintain backward compatibility NONE and OVERRIDE cgroups
 864		 * allow detaching with invalid FD (prog==NULL) in legacy mode
 865		 */
 866		return hlist_entry(progs->first, typeof(*pl), node);
 867	}
 868
 869	if (!prog && !link)
 870		/* to detach MULTI prog the user has to specify valid FD
 871		 * of the program or link to be detached
 872		 */
 873		return ERR_PTR(-EINVAL);
 874
 875	/* find the prog or link and detach it */
 876	hlist_for_each_entry(pl, progs, node) {
 877		if (pl->prog == prog && pl->link == link)
 878			return pl;
 879	}
 880	return ERR_PTR(-ENOENT);
 881}
 882
 883/**
 884 * purge_effective_progs() - After compute_effective_progs fails to alloc new
 885 *                           cgrp->bpf.inactive table we can recover by
 886 *                           recomputing the array in place.
 887 *
 888 * @cgrp: The cgroup which descendants to travers
 889 * @prog: A program to detach or NULL
 890 * @link: A link to detach or NULL
 891 * @atype: Type of detach operation
 892 */
 893static void purge_effective_progs(struct cgroup *cgrp, struct bpf_prog *prog,
 894				  struct bpf_cgroup_link *link,
 895				  enum cgroup_bpf_attach_type atype)
 896{
 897	struct cgroup_subsys_state *css;
 898	struct bpf_prog_array *progs;
 899	struct bpf_prog_list *pl;
 900	struct hlist_head *head;
 901	struct cgroup *cg;
 902	int pos;
 903
 904	/* recompute effective prog array in place */
 905	css_for_each_descendant_pre(css, &cgrp->self) {
 906		struct cgroup *desc = container_of(css, struct cgroup, self);
 907
 908		if (percpu_ref_is_zero(&desc->bpf.refcnt))
 909			continue;
 910
 911		/* find position of link or prog in effective progs array */
 912		for (pos = 0, cg = desc; cg; cg = cgroup_parent(cg)) {
 913			if (pos && !(cg->bpf.flags[atype] & BPF_F_ALLOW_MULTI))
 914				continue;
 915
 916			head = &cg->bpf.progs[atype];
 917			hlist_for_each_entry(pl, head, node) {
 918				if (!prog_list_prog(pl))
 919					continue;
 920				if (pl->prog == prog && pl->link == link)
 921					goto found;
 922				pos++;
 923			}
 924		}
 925
 926		/* no link or prog match, skip the cgroup of this layer */
 927		continue;
 928found:
 929		progs = rcu_dereference_protected(
 930				desc->bpf.effective[atype],
 931				lockdep_is_held(&cgroup_mutex));
 932
 933		/* Remove the program from the array */
 934		WARN_ONCE(bpf_prog_array_delete_safe_at(progs, pos),
 935			  "Failed to purge a prog from array at index %d", pos);
 936	}
 937}
 938
 939/**
 940 * __cgroup_bpf_detach() - Detach the program or link from a cgroup, and
 941 *                         propagate the change to descendants
 942 * @cgrp: The cgroup which descendants to traverse
 943 * @prog: A program to detach or NULL
 944 * @link: A link to detach or NULL
 945 * @type: Type of detach operation
 946 *
 947 * At most one of @prog or @link can be non-NULL.
 948 * Must be called with cgroup_mutex held.
 949 */
 950static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
 951			       struct bpf_cgroup_link *link, enum bpf_attach_type type)
 952{
 953	enum cgroup_bpf_attach_type atype;
 954	struct bpf_prog *old_prog;
 955	struct bpf_prog_list *pl;
 956	struct hlist_head *progs;
 957	u32 attach_btf_id = 0;
 958	u32 flags;
 959
 960	if (prog)
 961		attach_btf_id = prog->aux->attach_btf_id;
 962	if (link)
 963		attach_btf_id = link->link.prog->aux->attach_btf_id;
 964
 965	atype = bpf_cgroup_atype_find(type, attach_btf_id);
 966	if (atype < 0)
 967		return -EINVAL;
 968
 969	progs = &cgrp->bpf.progs[atype];
 970	flags = cgrp->bpf.flags[atype];
 971
 972	if (prog && link)
 973		/* only one of prog or link can be specified */
 974		return -EINVAL;
 975
 976	pl = find_detach_entry(progs, prog, link, flags & BPF_F_ALLOW_MULTI);
 977	if (IS_ERR(pl))
 978		return PTR_ERR(pl);
 979
 980	/* mark it deleted, so it's ignored while recomputing effective */
 981	old_prog = pl->prog;
 982	pl->prog = NULL;
 983	pl->link = NULL;
 984
 985	if (update_effective_progs(cgrp, atype)) {
 986		/* if update effective array failed replace the prog with a dummy prog*/
 987		pl->prog = old_prog;
 988		pl->link = link;
 989		purge_effective_progs(cgrp, old_prog, link, atype);
 990	}
 991
 992	/* now can actually delete it from this cgroup list */
 993	hlist_del(&pl->node);
 994
 995	kfree(pl);
 996	if (hlist_empty(progs))
 997		/* last program was detached, reset flags to zero */
 998		cgrp->bpf.flags[atype] = 0;
 999	if (old_prog) {
1000		if (type == BPF_LSM_CGROUP)
1001			bpf_trampoline_unlink_cgroup_shim(old_prog);
1002		bpf_prog_put(old_prog);
1003	}
1004	static_branch_dec(&cgroup_bpf_enabled_key[atype]);
1005	return 0;
1006}
1007
1008static int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
1009			     enum bpf_attach_type type)
1010{
1011	int ret;
1012
1013	cgroup_lock();
1014	ret = __cgroup_bpf_detach(cgrp, prog, NULL, type);
1015	cgroup_unlock();
1016	return ret;
1017}
1018
1019/* Must be called with cgroup_mutex held to avoid races. */
1020static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
1021			      union bpf_attr __user *uattr)
1022{
1023	__u32 __user *prog_attach_flags = u64_to_user_ptr(attr->query.prog_attach_flags);
1024	bool effective_query = attr->query.query_flags & BPF_F_QUERY_EFFECTIVE;
1025	__u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
1026	enum bpf_attach_type type = attr->query.attach_type;
1027	enum cgroup_bpf_attach_type from_atype, to_atype;
1028	enum cgroup_bpf_attach_type atype;
1029	struct bpf_prog_array *effective;
1030	int cnt, ret = 0, i;
1031	int total_cnt = 0;
1032	u32 flags;
1033
1034	if (effective_query && prog_attach_flags)
1035		return -EINVAL;
1036
1037	if (type == BPF_LSM_CGROUP) {
1038		if (!effective_query && attr->query.prog_cnt &&
1039		    prog_ids && !prog_attach_flags)
1040			return -EINVAL;
1041
1042		from_atype = CGROUP_LSM_START;
1043		to_atype = CGROUP_LSM_END;
1044		flags = 0;
1045	} else {
1046		from_atype = to_cgroup_bpf_attach_type(type);
1047		if (from_atype < 0)
1048			return -EINVAL;
1049		to_atype = from_atype;
1050		flags = cgrp->bpf.flags[from_atype];
1051	}
1052
1053	for (atype = from_atype; atype <= to_atype; atype++) {
1054		if (effective_query) {
1055			effective = rcu_dereference_protected(cgrp->bpf.effective[atype],
1056							      lockdep_is_held(&cgroup_mutex));
1057			total_cnt += bpf_prog_array_length(effective);
1058		} else {
1059			total_cnt += prog_list_length(&cgrp->bpf.progs[atype]);
1060		}
1061	}
1062
1063	/* always output uattr->query.attach_flags as 0 during effective query */
1064	flags = effective_query ? 0 : flags;
1065	if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
1066		return -EFAULT;
1067	if (copy_to_user(&uattr->query.prog_cnt, &total_cnt, sizeof(total_cnt)))
1068		return -EFAULT;
1069	if (attr->query.prog_cnt == 0 || !prog_ids || !total_cnt)
1070		/* return early if user requested only program count + flags */
1071		return 0;
1072
1073	if (attr->query.prog_cnt < total_cnt) {
1074		total_cnt = attr->query.prog_cnt;
1075		ret = -ENOSPC;
1076	}
1077
1078	for (atype = from_atype; atype <= to_atype && total_cnt; atype++) {
1079		if (effective_query) {
1080			effective = rcu_dereference_protected(cgrp->bpf.effective[atype],
1081							      lockdep_is_held(&cgroup_mutex));
1082			cnt = min_t(int, bpf_prog_array_length(effective), total_cnt);
1083			ret = bpf_prog_array_copy_to_user(effective, prog_ids, cnt);
1084		} else {
1085			struct hlist_head *progs;
1086			struct bpf_prog_list *pl;
1087			struct bpf_prog *prog;
1088			u32 id;
1089
1090			progs = &cgrp->bpf.progs[atype];
1091			cnt = min_t(int, prog_list_length(progs), total_cnt);
1092			i = 0;
1093			hlist_for_each_entry(pl, progs, node) {
1094				prog = prog_list_prog(pl);
1095				id = prog->aux->id;
1096				if (copy_to_user(prog_ids + i, &id, sizeof(id)))
1097					return -EFAULT;
1098				if (++i == cnt)
1099					break;
1100			}
1101
1102			if (prog_attach_flags) {
1103				flags = cgrp->bpf.flags[atype];
1104
1105				for (i = 0; i < cnt; i++)
1106					if (copy_to_user(prog_attach_flags + i,
1107							 &flags, sizeof(flags)))
1108						return -EFAULT;
1109				prog_attach_flags += cnt;
1110			}
1111		}
1112
1113		prog_ids += cnt;
1114		total_cnt -= cnt;
1115	}
1116	return ret;
1117}
1118
1119static int cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
1120			    union bpf_attr __user *uattr)
1121{
1122	int ret;
1123
1124	cgroup_lock();
1125	ret = __cgroup_bpf_query(cgrp, attr, uattr);
1126	cgroup_unlock();
1127	return ret;
1128}
1129
1130int cgroup_bpf_prog_attach(const union bpf_attr *attr,
1131			   enum bpf_prog_type ptype, struct bpf_prog *prog)
1132{
1133	struct bpf_prog *replace_prog = NULL;
1134	struct cgroup *cgrp;
1135	int ret;
1136
1137	cgrp = cgroup_get_from_fd(attr->target_fd);
1138	if (IS_ERR(cgrp))
1139		return PTR_ERR(cgrp);
1140
1141	if ((attr->attach_flags & BPF_F_ALLOW_MULTI) &&
1142	    (attr->attach_flags & BPF_F_REPLACE)) {
1143		replace_prog = bpf_prog_get_type(attr->replace_bpf_fd, ptype);
1144		if (IS_ERR(replace_prog)) {
1145			cgroup_put(cgrp);
1146			return PTR_ERR(replace_prog);
1147		}
1148	}
1149
1150	ret = cgroup_bpf_attach(cgrp, prog, replace_prog, NULL,
1151				attr->attach_type, attr->attach_flags);
1152
1153	if (replace_prog)
1154		bpf_prog_put(replace_prog);
1155	cgroup_put(cgrp);
1156	return ret;
1157}
1158
1159int cgroup_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
1160{
1161	struct bpf_prog *prog;
1162	struct cgroup *cgrp;
1163	int ret;
1164
1165	cgrp = cgroup_get_from_fd(attr->target_fd);
1166	if (IS_ERR(cgrp))
1167		return PTR_ERR(cgrp);
1168
1169	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
1170	if (IS_ERR(prog))
1171		prog = NULL;
1172
1173	ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type);
1174	if (prog)
1175		bpf_prog_put(prog);
1176
1177	cgroup_put(cgrp);
1178	return ret;
1179}
1180
1181static void bpf_cgroup_link_release(struct bpf_link *link)
1182{
1183	struct bpf_cgroup_link *cg_link =
1184		container_of(link, struct bpf_cgroup_link, link);
1185	struct cgroup *cg;
1186
1187	/* link might have been auto-detached by dying cgroup already,
1188	 * in that case our work is done here
1189	 */
1190	if (!cg_link->cgroup)
1191		return;
1192
1193	cgroup_lock();
1194
1195	/* re-check cgroup under lock again */
1196	if (!cg_link->cgroup) {
1197		cgroup_unlock();
1198		return;
1199	}
1200
1201	WARN_ON(__cgroup_bpf_detach(cg_link->cgroup, NULL, cg_link,
1202				    cg_link->type));
1203	if (cg_link->type == BPF_LSM_CGROUP)
1204		bpf_trampoline_unlink_cgroup_shim(cg_link->link.prog);
1205
1206	cg = cg_link->cgroup;
1207	cg_link->cgroup = NULL;
1208
1209	cgroup_unlock();
1210
1211	cgroup_put(cg);
1212}
1213
1214static void bpf_cgroup_link_dealloc(struct bpf_link *link)
1215{
1216	struct bpf_cgroup_link *cg_link =
1217		container_of(link, struct bpf_cgroup_link, link);
1218
1219	kfree(cg_link);
1220}
1221
1222static int bpf_cgroup_link_detach(struct bpf_link *link)
1223{
1224	bpf_cgroup_link_release(link);
1225
1226	return 0;
1227}
1228
1229static void bpf_cgroup_link_show_fdinfo(const struct bpf_link *link,
1230					struct seq_file *seq)
1231{
1232	struct bpf_cgroup_link *cg_link =
1233		container_of(link, struct bpf_cgroup_link, link);
1234	u64 cg_id = 0;
1235
1236	cgroup_lock();
1237	if (cg_link->cgroup)
1238		cg_id = cgroup_id(cg_link->cgroup);
1239	cgroup_unlock();
1240
1241	seq_printf(seq,
1242		   "cgroup_id:\t%llu\n"
1243		   "attach_type:\t%d\n",
1244		   cg_id,
1245		   cg_link->type);
1246}
1247
1248static int bpf_cgroup_link_fill_link_info(const struct bpf_link *link,
1249					  struct bpf_link_info *info)
1250{
1251	struct bpf_cgroup_link *cg_link =
1252		container_of(link, struct bpf_cgroup_link, link);
1253	u64 cg_id = 0;
1254
1255	cgroup_lock();
1256	if (cg_link->cgroup)
1257		cg_id = cgroup_id(cg_link->cgroup);
1258	cgroup_unlock();
1259
1260	info->cgroup.cgroup_id = cg_id;
1261	info->cgroup.attach_type = cg_link->type;
1262	return 0;
1263}
1264
1265static const struct bpf_link_ops bpf_cgroup_link_lops = {
1266	.release = bpf_cgroup_link_release,
1267	.dealloc = bpf_cgroup_link_dealloc,
1268	.detach = bpf_cgroup_link_detach,
1269	.update_prog = cgroup_bpf_replace,
1270	.show_fdinfo = bpf_cgroup_link_show_fdinfo,
1271	.fill_link_info = bpf_cgroup_link_fill_link_info,
1272};
1273
1274int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
1275{
1276	struct bpf_link_primer link_primer;
1277	struct bpf_cgroup_link *link;
1278	struct cgroup *cgrp;
1279	int err;
1280
1281	if (attr->link_create.flags)
1282		return -EINVAL;
1283
1284	cgrp = cgroup_get_from_fd(attr->link_create.target_fd);
1285	if (IS_ERR(cgrp))
1286		return PTR_ERR(cgrp);
1287
1288	link = kzalloc(sizeof(*link), GFP_USER);
1289	if (!link) {
1290		err = -ENOMEM;
1291		goto out_put_cgroup;
1292	}
1293	bpf_link_init(&link->link, BPF_LINK_TYPE_CGROUP, &bpf_cgroup_link_lops,
1294		      prog);
1295	link->cgroup = cgrp;
1296	link->type = attr->link_create.attach_type;
1297
1298	err = bpf_link_prime(&link->link, &link_primer);
1299	if (err) {
1300		kfree(link);
1301		goto out_put_cgroup;
1302	}
1303
1304	err = cgroup_bpf_attach(cgrp, NULL, NULL, link,
1305				link->type, BPF_F_ALLOW_MULTI);
1306	if (err) {
1307		bpf_link_cleanup(&link_primer);
1308		goto out_put_cgroup;
1309	}
1310
1311	return bpf_link_settle(&link_primer);
1312
1313out_put_cgroup:
1314	cgroup_put(cgrp);
1315	return err;
1316}
1317
1318int cgroup_bpf_prog_query(const union bpf_attr *attr,
1319			  union bpf_attr __user *uattr)
1320{
1321	struct cgroup *cgrp;
1322	int ret;
1323
1324	cgrp = cgroup_get_from_fd(attr->query.target_fd);
1325	if (IS_ERR(cgrp))
1326		return PTR_ERR(cgrp);
1327
1328	ret = cgroup_bpf_query(cgrp, attr, uattr);
1329
1330	cgroup_put(cgrp);
1331	return ret;
1332}
1333
1334/**
1335 * __cgroup_bpf_run_filter_skb() - Run a program for packet filtering
1336 * @sk: The socket sending or receiving traffic
1337 * @skb: The skb that is being sent or received
1338 * @atype: The type of program to be executed
1339 *
1340 * If no socket is passed, or the socket is not of type INET or INET6,
1341 * this function does nothing and returns 0.
1342 *
1343 * The program type passed in via @type must be suitable for network
1344 * filtering. No further check is performed to assert that.
1345 *
1346 * For egress packets, this function can return:
1347 *   NET_XMIT_SUCCESS    (0)	- continue with packet output
1348 *   NET_XMIT_DROP       (1)	- drop packet and notify TCP to call cwr
1349 *   NET_XMIT_CN         (2)	- continue with packet output and notify TCP
1350 *				  to call cwr
1351 *   -err			- drop packet
1352 *
1353 * For ingress packets, this function will return -EPERM if any
1354 * attached program was found and if it returned != 1 during execution.
1355 * Otherwise 0 is returned.
1356 */
1357int __cgroup_bpf_run_filter_skb(struct sock *sk,
1358				struct sk_buff *skb,
1359				enum cgroup_bpf_attach_type atype)
1360{
1361	unsigned int offset = skb->data - skb_network_header(skb);
1362	struct sock *save_sk;
1363	void *saved_data_end;
1364	struct cgroup *cgrp;
1365	int ret;
1366
1367	if (!sk || !sk_fullsock(sk))
1368		return 0;
1369
1370	if (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)
1371		return 0;
1372
1373	cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
1374	save_sk = skb->sk;
1375	skb->sk = sk;
1376	__skb_push(skb, offset);
1377
1378	/* compute pointers for the bpf prog */
1379	bpf_compute_and_save_data_end(skb, &saved_data_end);
1380
1381	if (atype == CGROUP_INET_EGRESS) {
1382		u32 flags = 0;
1383		bool cn;
1384
1385		ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, skb,
1386					    __bpf_prog_run_save_cb, 0, &flags);
1387
1388		/* Return values of CGROUP EGRESS BPF programs are:
1389		 *   0: drop packet
1390		 *   1: keep packet
1391		 *   2: drop packet and cn
1392		 *   3: keep packet and cn
1393		 *
1394		 * The returned value is then converted to one of the NET_XMIT
1395		 * or an error code that is then interpreted as drop packet
1396		 * (and no cn):
1397		 *   0: NET_XMIT_SUCCESS  skb should be transmitted
1398		 *   1: NET_XMIT_DROP     skb should be dropped and cn
1399		 *   2: NET_XMIT_CN       skb should be transmitted and cn
1400		 *   3: -err              skb should be dropped
1401		 */
1402
1403		cn = flags & BPF_RET_SET_CN;
1404		if (ret && !IS_ERR_VALUE((long)ret))
1405			ret = -EFAULT;
1406		if (!ret)
1407			ret = (cn ? NET_XMIT_CN : NET_XMIT_SUCCESS);
1408		else
1409			ret = (cn ? NET_XMIT_DROP : ret);
1410	} else {
1411		ret = bpf_prog_run_array_cg(&cgrp->bpf, atype,
1412					    skb, __bpf_prog_run_save_cb, 0,
1413					    NULL);
1414		if (ret && !IS_ERR_VALUE((long)ret))
1415			ret = -EFAULT;
1416	}
1417	bpf_restore_data_end(skb, saved_data_end);
1418	__skb_pull(skb, offset);
1419	skb->sk = save_sk;
1420
1421	return ret;
1422}
1423EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb);
1424
1425/**
1426 * __cgroup_bpf_run_filter_sk() - Run a program on a sock
1427 * @sk: sock structure to manipulate
1428 * @atype: The type of program to be executed
1429 *
1430 * socket is passed is expected to be of type INET or INET6.
1431 *
1432 * The program type passed in via @type must be suitable for sock
1433 * filtering. No further check is performed to assert that.
1434 *
1435 * This function will return %-EPERM if any if an attached program was found
1436 * and if it returned != 1 during execution. In all other cases, 0 is returned.
1437 */
1438int __cgroup_bpf_run_filter_sk(struct sock *sk,
1439			       enum cgroup_bpf_attach_type atype)
1440{
1441	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
1442
1443	return bpf_prog_run_array_cg(&cgrp->bpf, atype, sk, bpf_prog_run, 0,
1444				     NULL);
1445}
1446EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk);
1447
1448/**
1449 * __cgroup_bpf_run_filter_sock_addr() - Run a program on a sock and
1450 *                                       provided by user sockaddr
1451 * @sk: sock struct that will use sockaddr
1452 * @uaddr: sockaddr struct provided by user
1453 * @uaddrlen: Pointer to the size of the sockaddr struct provided by user. It is
1454 *            read-only for AF_INET[6] uaddr but can be modified for AF_UNIX
1455 *            uaddr.
1456 * @atype: The type of program to be executed
1457 * @t_ctx: Pointer to attach type specific context
1458 * @flags: Pointer to u32 which contains higher bits of BPF program
1459 *         return value (OR'ed together).
1460 *
1461 * socket is expected to be of type INET, INET6 or UNIX.
1462 *
1463 * This function will return %-EPERM if an attached program is found and
1464 * returned value != 1 during execution. In all other cases, 0 is returned.
1465 */
1466int __cgroup_bpf_run_filter_sock_addr(struct sock *sk,
1467				      struct sockaddr *uaddr,
1468				      int *uaddrlen,
1469				      enum cgroup_bpf_attach_type atype,
1470				      void *t_ctx,
1471				      u32 *flags)
1472{
1473	struct bpf_sock_addr_kern ctx = {
1474		.sk = sk,
1475		.uaddr = uaddr,
1476		.t_ctx = t_ctx,
1477	};
1478	struct sockaddr_storage unspec;
1479	struct cgroup *cgrp;
1480	int ret;
1481
1482	/* Check socket family since not all sockets represent network
1483	 * endpoint (e.g. AF_UNIX).
1484	 */
1485	if (sk->sk_family != AF_INET && sk->sk_family != AF_INET6 &&
1486	    sk->sk_family != AF_UNIX)
1487		return 0;
1488
1489	if (!ctx.uaddr) {
1490		memset(&unspec, 0, sizeof(unspec));
1491		ctx.uaddr = (struct sockaddr *)&unspec;
1492		ctx.uaddrlen = 0;
1493	} else {
1494		ctx.uaddrlen = *uaddrlen;
1495	}
1496
1497	cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
1498	ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run,
1499				    0, flags);
1500
1501	if (!ret && uaddr)
1502		*uaddrlen = ctx.uaddrlen;
1503
1504	return ret;
1505}
1506EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_addr);
1507
1508/**
1509 * __cgroup_bpf_run_filter_sock_ops() - Run a program on a sock
1510 * @sk: socket to get cgroup from
1511 * @sock_ops: bpf_sock_ops_kern struct to pass to program. Contains
1512 * sk with connection information (IP addresses, etc.) May not contain
1513 * cgroup info if it is a req sock.
1514 * @atype: The type of program to be executed
1515 *
1516 * socket passed is expected to be of type INET or INET6.
1517 *
1518 * The program type passed in via @type must be suitable for sock_ops
1519 * filtering. No further check is performed to assert that.
1520 *
1521 * This function will return %-EPERM if any if an attached program was found
1522 * and if it returned != 1 during execution. In all other cases, 0 is returned.
1523 */
1524int __cgroup_bpf_run_filter_sock_ops(struct sock *sk,
1525				     struct bpf_sock_ops_kern *sock_ops,
1526				     enum cgroup_bpf_attach_type atype)
1527{
1528	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
1529
1530	return bpf_prog_run_array_cg(&cgrp->bpf, atype, sock_ops, bpf_prog_run,
1531				     0, NULL);
1532}
1533EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_ops);
1534
1535int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
1536				      short access, enum cgroup_bpf_attach_type atype)
1537{
1538	struct cgroup *cgrp;
1539	struct bpf_cgroup_dev_ctx ctx = {
1540		.access_type = (access << 16) | dev_type,
1541		.major = major,
1542		.minor = minor,
1543	};
1544	int ret;
1545
1546	rcu_read_lock();
1547	cgrp = task_dfl_cgroup(current);
1548	ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run, 0,
1549				    NULL);
1550	rcu_read_unlock();
1551
1552	return ret;
1553}
1554
1555BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags)
1556{
1557	/* flags argument is not used now,
1558	 * but provides an ability to extend the API.
1559	 * verifier checks that its value is correct.
1560	 */
1561	enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
1562	struct bpf_cgroup_storage *storage;
1563	struct bpf_cg_run_ctx *ctx;
1564	void *ptr;
1565
1566	/* get current cgroup storage from BPF run context */
1567	ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
1568	storage = ctx->prog_item->cgroup_storage[stype];
1569
1570	if (stype == BPF_CGROUP_STORAGE_SHARED)
1571		ptr = &READ_ONCE(storage->buf)->data[0];
1572	else
1573		ptr = this_cpu_ptr(storage->percpu_buf);
1574
1575	return (unsigned long)ptr;
1576}
1577
1578const struct bpf_func_proto bpf_get_local_storage_proto = {
1579	.func		= bpf_get_local_storage,
1580	.gpl_only	= false,
1581	.ret_type	= RET_PTR_TO_MAP_VALUE,
1582	.arg1_type	= ARG_CONST_MAP_PTR,
1583	.arg2_type	= ARG_ANYTHING,
1584};
1585
1586BPF_CALL_0(bpf_get_retval)
1587{
1588	struct bpf_cg_run_ctx *ctx =
1589		container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
1590
1591	return ctx->retval;
1592}
1593
1594const struct bpf_func_proto bpf_get_retval_proto = {
1595	.func		= bpf_get_retval,
1596	.gpl_only	= false,
1597	.ret_type	= RET_INTEGER,
1598};
1599
1600BPF_CALL_1(bpf_set_retval, int, retval)
1601{
1602	struct bpf_cg_run_ctx *ctx =
1603		container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
1604
1605	ctx->retval = retval;
1606	return 0;
1607}
1608
1609const struct bpf_func_proto bpf_set_retval_proto = {
1610	.func		= bpf_set_retval,
1611	.gpl_only	= false,
1612	.ret_type	= RET_INTEGER,
1613	.arg1_type	= ARG_ANYTHING,
1614};
1615
1616static const struct bpf_func_proto *
1617cgroup_dev_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
1618{
1619	const struct bpf_func_proto *func_proto;
1620
1621	func_proto = cgroup_common_func_proto(func_id, prog);
1622	if (func_proto)
1623		return func_proto;
1624
1625	func_proto = cgroup_current_func_proto(func_id, prog);
1626	if (func_proto)
1627		return func_proto;
1628
1629	switch (func_id) {
1630	case BPF_FUNC_perf_event_output:
1631		return &bpf_event_output_data_proto;
1632	default:
1633		return bpf_base_func_proto(func_id);
1634	}
1635}
1636
1637static bool cgroup_dev_is_valid_access(int off, int size,
1638				       enum bpf_access_type type,
1639				       const struct bpf_prog *prog,
1640				       struct bpf_insn_access_aux *info)
1641{
1642	const int size_default = sizeof(__u32);
1643
1644	if (type == BPF_WRITE)
1645		return false;
1646
1647	if (off < 0 || off + size > sizeof(struct bpf_cgroup_dev_ctx))
1648		return false;
1649	/* The verifier guarantees that size > 0. */
1650	if (off % size != 0)
1651		return false;
1652
1653	switch (off) {
1654	case bpf_ctx_range(struct bpf_cgroup_dev_ctx, access_type):
1655		bpf_ctx_record_field_size(info, size_default);
1656		if (!bpf_ctx_narrow_access_ok(off, size, size_default))
1657			return false;
1658		break;
1659	default:
1660		if (size != size_default)
1661			return false;
1662	}
1663
1664	return true;
1665}
1666
1667const struct bpf_prog_ops cg_dev_prog_ops = {
1668};
1669
1670const struct bpf_verifier_ops cg_dev_verifier_ops = {
1671	.get_func_proto		= cgroup_dev_func_proto,
1672	.is_valid_access	= cgroup_dev_is_valid_access,
1673};
1674
1675/**
1676 * __cgroup_bpf_run_filter_sysctl - Run a program on sysctl
1677 *
1678 * @head: sysctl table header
1679 * @table: sysctl table
1680 * @write: sysctl is being read (= 0) or written (= 1)
1681 * @buf: pointer to buffer (in and out)
1682 * @pcount: value-result argument: value is size of buffer pointed to by @buf,
1683 *	result is size of @new_buf if program set new value, initial value
1684 *	otherwise
1685 * @ppos: value-result argument: value is position at which read from or write
1686 *	to sysctl is happening, result is new position if program overrode it,
1687 *	initial value otherwise
1688 * @atype: type of program to be executed
1689 *
1690 * Program is run when sysctl is being accessed, either read or written, and
1691 * can allow or deny such access.
1692 *
1693 * This function will return %-EPERM if an attached program is found and
1694 * returned value != 1 during execution. In all other cases 0 is returned.
1695 */
1696int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
1697				   struct ctl_table *table, int write,
1698				   char **buf, size_t *pcount, loff_t *ppos,
1699				   enum cgroup_bpf_attach_type atype)
1700{
1701	struct bpf_sysctl_kern ctx = {
1702		.head = head,
1703		.table = table,
1704		.write = write,
1705		.ppos = ppos,
1706		.cur_val = NULL,
1707		.cur_len = PAGE_SIZE,
1708		.new_val = NULL,
1709		.new_len = 0,
1710		.new_updated = 0,
1711	};
1712	struct cgroup *cgrp;
1713	loff_t pos = 0;
1714	int ret;
1715
1716	ctx.cur_val = kmalloc_track_caller(ctx.cur_len, GFP_KERNEL);
1717	if (!ctx.cur_val ||
1718	    table->proc_handler(table, 0, ctx.cur_val, &ctx.cur_len, &pos)) {
1719		/* Let BPF program decide how to proceed. */
1720		ctx.cur_len = 0;
1721	}
1722
1723	if (write && *buf && *pcount) {
1724		/* BPF program should be able to override new value with a
1725		 * buffer bigger than provided by user.
1726		 */
1727		ctx.new_val = kmalloc_track_caller(PAGE_SIZE, GFP_KERNEL);
1728		ctx.new_len = min_t(size_t, PAGE_SIZE, *pcount);
1729		if (ctx.new_val) {
1730			memcpy(ctx.new_val, *buf, ctx.new_len);
1731		} else {
1732			/* Let BPF program decide how to proceed. */
1733			ctx.new_len = 0;
1734		}
1735	}
1736
1737	rcu_read_lock();
1738	cgrp = task_dfl_cgroup(current);
1739	ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run, 0,
1740				    NULL);
1741	rcu_read_unlock();
1742
1743	kfree(ctx.cur_val);
1744
1745	if (ret == 1 && ctx.new_updated) {
1746		kfree(*buf);
1747		*buf = ctx.new_val;
1748		*pcount = ctx.new_len;
1749	} else {
1750		kfree(ctx.new_val);
1751	}
1752
1753	return ret;
1754}
1755
1756#ifdef CONFIG_NET
1757static int sockopt_alloc_buf(struct bpf_sockopt_kern *ctx, int max_optlen,
1758			     struct bpf_sockopt_buf *buf)
1759{
1760	if (unlikely(max_optlen < 0))
1761		return -EINVAL;
1762
1763	if (unlikely(max_optlen > PAGE_SIZE)) {
1764		/* We don't expose optvals that are greater than PAGE_SIZE
1765		 * to the BPF program.
1766		 */
1767		max_optlen = PAGE_SIZE;
1768	}
1769
1770	if (max_optlen <= sizeof(buf->data)) {
1771		/* When the optval fits into BPF_SOCKOPT_KERN_BUF_SIZE
1772		 * bytes avoid the cost of kzalloc.
1773		 */
1774		ctx->optval = buf->data;
1775		ctx->optval_end = ctx->optval + max_optlen;
1776		return max_optlen;
1777	}
1778
1779	ctx->optval = kzalloc(max_optlen, GFP_USER);
1780	if (!ctx->optval)
1781		return -ENOMEM;
1782
1783	ctx->optval_end = ctx->optval + max_optlen;
1784
1785	return max_optlen;
1786}
1787
1788static void sockopt_free_buf(struct bpf_sockopt_kern *ctx,
1789			     struct bpf_sockopt_buf *buf)
1790{
1791	if (ctx->optval == buf->data)
1792		return;
1793	kfree(ctx->optval);
1794}
1795
1796static bool sockopt_buf_allocated(struct bpf_sockopt_kern *ctx,
1797				  struct bpf_sockopt_buf *buf)
1798{
1799	return ctx->optval != buf->data;
1800}
1801
1802int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
1803				       int *optname, sockptr_t optval,
1804				       int *optlen, char **kernel_optval)
1805{
1806	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
1807	struct bpf_sockopt_buf buf = {};
1808	struct bpf_sockopt_kern ctx = {
1809		.sk = sk,
1810		.level = *level,
1811		.optname = *optname,
1812	};
1813	int ret, max_optlen;
1814
1815	/* Allocate a bit more than the initial user buffer for
1816	 * BPF program. The canonical use case is overriding
1817	 * TCP_CONGESTION(nv) to TCP_CONGESTION(cubic).
1818	 */
1819	max_optlen = max_t(int, 16, *optlen);
1820	max_optlen = sockopt_alloc_buf(&ctx, max_optlen, &buf);
1821	if (max_optlen < 0)
1822		return max_optlen;
1823
1824	ctx.optlen = *optlen;
1825
1826	if (copy_from_sockptr(ctx.optval, optval,
1827			      min(*optlen, max_optlen))) {
1828		ret = -EFAULT;
1829		goto out;
1830	}
1831
1832	lock_sock(sk);
1833	ret = bpf_prog_run_array_cg(&cgrp->bpf, CGROUP_SETSOCKOPT,
1834				    &ctx, bpf_prog_run, 0, NULL);
1835	release_sock(sk);
1836
1837	if (ret)
1838		goto out;
1839
1840	if (ctx.optlen == -1) {
1841		/* optlen set to -1, bypass kernel */
1842		ret = 1;
1843	} else if (ctx.optlen > max_optlen || ctx.optlen < -1) {
1844		/* optlen is out of bounds */
1845		if (*optlen > PAGE_SIZE && ctx.optlen >= 0) {
1846			pr_info_once("bpf setsockopt: ignoring program buffer with optlen=%d (max_optlen=%d)\n",
1847				     ctx.optlen, max_optlen);
1848			ret = 0;
1849			goto out;
1850		}
1851		ret = -EFAULT;
1852	} else {
1853		/* optlen within bounds, run kernel handler */
1854		ret = 0;
1855
1856		/* export any potential modifications */
1857		*level = ctx.level;
1858		*optname = ctx.optname;
1859
1860		/* optlen == 0 from BPF indicates that we should
1861		 * use original userspace data.
1862		 */
1863		if (ctx.optlen != 0) {
1864			*optlen = ctx.optlen;
1865			/* We've used bpf_sockopt_kern->buf as an intermediary
1866			 * storage, but the BPF program indicates that we need
1867			 * to pass this data to the kernel setsockopt handler.
1868			 * No way to export on-stack buf, have to allocate a
1869			 * new buffer.
1870			 */
1871			if (!sockopt_buf_allocated(&ctx, &buf)) {
1872				void *p = kmalloc(ctx.optlen, GFP_USER);
1873
1874				if (!p) {
1875					ret = -ENOMEM;
1876					goto out;
1877				}
1878				memcpy(p, ctx.optval, ctx.optlen);
1879				*kernel_optval = p;
1880			} else {
1881				*kernel_optval = ctx.optval;
1882			}
1883			/* export and don't free sockopt buf */
1884			return 0;
1885		}
1886	}
1887
1888out:
1889	sockopt_free_buf(&ctx, &buf);
1890	return ret;
1891}
1892
1893int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
1894				       int optname, sockptr_t optval,
1895				       sockptr_t optlen, int max_optlen,
1896				       int retval)
1897{
1898	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
1899	struct bpf_sockopt_buf buf = {};
1900	struct bpf_sockopt_kern ctx = {
1901		.sk = sk,
1902		.level = level,
1903		.optname = optname,
1904		.current_task = current,
1905	};
1906	int orig_optlen;
1907	int ret;
1908
1909	orig_optlen = max_optlen;
1910	ctx.optlen = max_optlen;
1911	max_optlen = sockopt_alloc_buf(&ctx, max_optlen, &buf);
1912	if (max_optlen < 0)
1913		return max_optlen;
1914
1915	if (!retval) {
1916		/* If kernel getsockopt finished successfully,
1917		 * copy whatever was returned to the user back
1918		 * into our temporary buffer. Set optlen to the
1919		 * one that kernel returned as well to let
1920		 * BPF programs inspect the value.
1921		 */
1922		if (copy_from_sockptr(&ctx.optlen, optlen,
1923				      sizeof(ctx.optlen))) {
1924			ret = -EFAULT;
1925			goto out;
1926		}
1927
1928		if (ctx.optlen < 0) {
1929			ret = -EFAULT;
1930			goto out;
1931		}
1932		orig_optlen = ctx.optlen;
1933
1934		if (copy_from_sockptr(ctx.optval, optval,
1935				      min(ctx.optlen, max_optlen))) {
1936			ret = -EFAULT;
1937			goto out;
1938		}
1939	}
1940
1941	lock_sock(sk);
1942	ret = bpf_prog_run_array_cg(&cgrp->bpf, CGROUP_GETSOCKOPT,
1943				    &ctx, bpf_prog_run, retval, NULL);
1944	release_sock(sk);
1945
1946	if (ret < 0)
1947		goto out;
1948
1949	if (!sockptr_is_null(optval) &&
1950	    (ctx.optlen > max_optlen || ctx.optlen < 0)) {
1951		if (orig_optlen > PAGE_SIZE && ctx.optlen >= 0) {
1952			pr_info_once("bpf getsockopt: ignoring program buffer with optlen=%d (max_optlen=%d)\n",
1953				     ctx.optlen, max_optlen);
1954			ret = retval;
1955			goto out;
1956		}
1957		ret = -EFAULT;
1958		goto out;
1959	}
1960
1961	if (ctx.optlen != 0) {
1962		if (!sockptr_is_null(optval) &&
1963		    copy_to_sockptr(optval, ctx.optval, ctx.optlen)) {
1964			ret = -EFAULT;
1965			goto out;
1966		}
1967		if (copy_to_sockptr(optlen, &ctx.optlen, sizeof(ctx.optlen))) {
1968			ret = -EFAULT;
1969			goto out;
1970		}
1971	}
1972
1973out:
1974	sockopt_free_buf(&ctx, &buf);
1975	return ret;
1976}
1977
1978int __cgroup_bpf_run_filter_getsockopt_kern(struct sock *sk, int level,
1979					    int optname, void *optval,
1980					    int *optlen, int retval)
1981{
1982	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
1983	struct bpf_sockopt_kern ctx = {
1984		.sk = sk,
1985		.level = level,
1986		.optname = optname,
1987		.optlen = *optlen,
1988		.optval = optval,
1989		.optval_end = optval + *optlen,
1990		.current_task = current,
1991	};
1992	int ret;
1993
1994	/* Note that __cgroup_bpf_run_filter_getsockopt doesn't copy
1995	 * user data back into BPF buffer when reval != 0. This is
1996	 * done as an optimization to avoid extra copy, assuming
1997	 * kernel won't populate the data in case of an error.
1998	 * Here we always pass the data and memset() should
1999	 * be called if that data shouldn't be "exported".
2000	 */
2001
2002	ret = bpf_prog_run_array_cg(&cgrp->bpf, CGROUP_GETSOCKOPT,
2003				    &ctx, bpf_prog_run, retval, NULL);
2004	if (ret < 0)
2005		return ret;
2006
2007	if (ctx.optlen > *optlen)
2008		return -EFAULT;
2009
2010	/* BPF programs can shrink the buffer, export the modifications.
2011	 */
2012	if (ctx.optlen != 0)
2013		*optlen = ctx.optlen;
2014
2015	return ret;
2016}
2017#endif
2018
2019static ssize_t sysctl_cpy_dir(const struct ctl_dir *dir, char **bufp,
2020			      size_t *lenp)
2021{
2022	ssize_t tmp_ret = 0, ret;
2023
2024	if (dir->header.parent) {
2025		tmp_ret = sysctl_cpy_dir(dir->header.parent, bufp, lenp);
2026		if (tmp_ret < 0)
2027			return tmp_ret;
2028	}
2029
2030	ret = strscpy(*bufp, dir->header.ctl_table[0].procname, *lenp);
2031	if (ret < 0)
2032		return ret;
2033	*bufp += ret;
2034	*lenp -= ret;
2035	ret += tmp_ret;
2036
2037	/* Avoid leading slash. */
2038	if (!ret)
2039		return ret;
2040
2041	tmp_ret = strscpy(*bufp, "/", *lenp);
2042	if (tmp_ret < 0)
2043		return tmp_ret;
2044	*bufp += tmp_ret;
2045	*lenp -= tmp_ret;
2046
2047	return ret + tmp_ret;
2048}
2049
2050BPF_CALL_4(bpf_sysctl_get_name, struct bpf_sysctl_kern *, ctx, char *, buf,
2051	   size_t, buf_len, u64, flags)
2052{
2053	ssize_t tmp_ret = 0, ret;
2054
2055	if (!buf)
2056		return -EINVAL;
2057
2058	if (!(flags & BPF_F_SYSCTL_BASE_NAME)) {
2059		if (!ctx->head)
2060			return -EINVAL;
2061		tmp_ret = sysctl_cpy_dir(ctx->head->parent, &buf, &buf_len);
2062		if (tmp_ret < 0)
2063			return tmp_ret;
2064	}
2065
2066	ret = strscpy(buf, ctx->table->procname, buf_len);
2067
2068	return ret < 0 ? ret : tmp_ret + ret;
2069}
2070
2071static const struct bpf_func_proto bpf_sysctl_get_name_proto = {
2072	.func		= bpf_sysctl_get_name,
2073	.gpl_only	= false,
2074	.ret_type	= RET_INTEGER,
2075	.arg1_type	= ARG_PTR_TO_CTX,
2076	.arg2_type	= ARG_PTR_TO_MEM,
2077	.arg3_type	= ARG_CONST_SIZE,
2078	.arg4_type	= ARG_ANYTHING,
2079};
2080
2081static int copy_sysctl_value(char *dst, size_t dst_len, char *src,
2082			     size_t src_len)
2083{
2084	if (!dst)
2085		return -EINVAL;
2086
2087	if (!dst_len)
2088		return -E2BIG;
2089
2090	if (!src || !src_len) {
2091		memset(dst, 0, dst_len);
2092		return -EINVAL;
2093	}
2094
2095	memcpy(dst, src, min(dst_len, src_len));
2096
2097	if (dst_len > src_len) {
2098		memset(dst + src_len, '\0', dst_len - src_len);
2099		return src_len;
2100	}
2101
2102	dst[dst_len - 1] = '\0';
2103
2104	return -E2BIG;
2105}
2106
2107BPF_CALL_3(bpf_sysctl_get_current_value, struct bpf_sysctl_kern *, ctx,
2108	   char *, buf, size_t, buf_len)
2109{
2110	return copy_sysctl_value(buf, buf_len, ctx->cur_val, ctx->cur_len);
2111}
2112
2113static const struct bpf_func_proto bpf_sysctl_get_current_value_proto = {
2114	.func		= bpf_sysctl_get_current_value,
2115	.gpl_only	= false,
2116	.ret_type	= RET_INTEGER,
2117	.arg1_type	= ARG_PTR_TO_CTX,
2118	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
2119	.arg3_type	= ARG_CONST_SIZE,
2120};
2121
2122BPF_CALL_3(bpf_sysctl_get_new_value, struct bpf_sysctl_kern *, ctx, char *, buf,
2123	   size_t, buf_len)
2124{
2125	if (!ctx->write) {
2126		if (buf && buf_len)
2127			memset(buf, '\0', buf_len);
2128		return -EINVAL;
2129	}
2130	return copy_sysctl_value(buf, buf_len, ctx->new_val, ctx->new_len);
2131}
2132
2133static const struct bpf_func_proto bpf_sysctl_get_new_value_proto = {
2134	.func		= bpf_sysctl_get_new_value,
2135	.gpl_only	= false,
2136	.ret_type	= RET_INTEGER,
2137	.arg1_type	= ARG_PTR_TO_CTX,
2138	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,
2139	.arg3_type	= ARG_CONST_SIZE,
2140};
2141
2142BPF_CALL_3(bpf_sysctl_set_new_value, struct bpf_sysctl_kern *, ctx,
2143	   const char *, buf, size_t, buf_len)
2144{
2145	if (!ctx->write || !ctx->new_val || !ctx->new_len || !buf || !buf_len)
2146		return -EINVAL;
2147
2148	if (buf_len > PAGE_SIZE - 1)
2149		return -E2BIG;
2150
2151	memcpy(ctx->new_val, buf, buf_len);
2152	ctx->new_len = buf_len;
2153	ctx->new_updated = 1;
2154
2155	return 0;
2156}
2157
2158static const struct bpf_func_proto bpf_sysctl_set_new_value_proto = {
2159	.func		= bpf_sysctl_set_new_value,
2160	.gpl_only	= false,
2161	.ret_type	= RET_INTEGER,
2162	.arg1_type	= ARG_PTR_TO_CTX,
2163	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
2164	.arg3_type	= ARG_CONST_SIZE,
2165};
2166
2167static const struct bpf_func_proto *
2168sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
2169{
2170	const struct bpf_func_proto *func_proto;
2171
2172	func_proto = cgroup_common_func_proto(func_id, prog);
2173	if (func_proto)
2174		return func_proto;
2175
2176	func_proto = cgroup_current_func_proto(func_id, prog);
2177	if (func_proto)
2178		return func_proto;
2179
2180	switch (func_id) {
2181	case BPF_FUNC_sysctl_get_name:
2182		return &bpf_sysctl_get_name_proto;
2183	case BPF_FUNC_sysctl_get_current_value:
2184		return &bpf_sysctl_get_current_value_proto;
2185	case BPF_FUNC_sysctl_get_new_value:
2186		return &bpf_sysctl_get_new_value_proto;
2187	case BPF_FUNC_sysctl_set_new_value:
2188		return &bpf_sysctl_set_new_value_proto;
2189	case BPF_FUNC_ktime_get_coarse_ns:
2190		return &bpf_ktime_get_coarse_ns_proto;
2191	case BPF_FUNC_perf_event_output:
2192		return &bpf_event_output_data_proto;
2193	default:
2194		return bpf_base_func_proto(func_id);
2195	}
2196}
2197
2198static bool sysctl_is_valid_access(int off, int size, enum bpf_access_type type,
2199				   const struct bpf_prog *prog,
2200				   struct bpf_insn_access_aux *info)
2201{
2202	const int size_default = sizeof(__u32);
2203
2204	if (off < 0 || off + size > sizeof(struct bpf_sysctl) || off % size)
2205		return false;
2206
2207	switch (off) {
2208	case bpf_ctx_range(struct bpf_sysctl, write):
2209		if (type != BPF_READ)
2210			return false;
2211		bpf_ctx_record_field_size(info, size_default);
2212		return bpf_ctx_narrow_access_ok(off, size, size_default);
2213	case bpf_ctx_range(struct bpf_sysctl, file_pos):
2214		if (type == BPF_READ) {
2215			bpf_ctx_record_field_size(info, size_default);
2216			return bpf_ctx_narrow_access_ok(off, size, size_default);
2217		} else {
2218			return size == size_default;
2219		}
2220	default:
2221		return false;
2222	}
2223}
2224
2225static u32 sysctl_convert_ctx_access(enum bpf_access_type type,
2226				     const struct bpf_insn *si,
2227				     struct bpf_insn *insn_buf,
2228				     struct bpf_prog *prog, u32 *target_size)
2229{
2230	struct bpf_insn *insn = insn_buf;
2231	u32 read_size;
2232
2233	switch (si->off) {
2234	case offsetof(struct bpf_sysctl, write):
2235		*insn++ = BPF_LDX_MEM(
2236			BPF_SIZE(si->code), si->dst_reg, si->src_reg,
2237			bpf_target_off(struct bpf_sysctl_kern, write,
2238				       sizeof_field(struct bpf_sysctl_kern,
2239						    write),
2240				       target_size));
2241		break;
2242	case offsetof(struct bpf_sysctl, file_pos):
2243		/* ppos is a pointer so it should be accessed via indirect
2244		 * loads and stores. Also for stores additional temporary
2245		 * register is used since neither src_reg nor dst_reg can be
2246		 * overridden.
2247		 */
2248		if (type == BPF_WRITE) {
2249			int treg = BPF_REG_9;
2250
2251			if (si->src_reg == treg || si->dst_reg == treg)
2252				--treg;
2253			if (si->src_reg == treg || si->dst_reg == treg)
2254				--treg;
2255			*insn++ = BPF_STX_MEM(
2256				BPF_DW, si->dst_reg, treg,
2257				offsetof(struct bpf_sysctl_kern, tmp_reg));
2258			*insn++ = BPF_LDX_MEM(
2259				BPF_FIELD_SIZEOF(struct bpf_sysctl_kern, ppos),
2260				treg, si->dst_reg,
2261				offsetof(struct bpf_sysctl_kern, ppos));
2262			*insn++ = BPF_RAW_INSN(
2263				BPF_CLASS(si->code) | BPF_MEM | BPF_SIZEOF(u32),
2264				treg, si->src_reg,
2265				bpf_ctx_narrow_access_offset(
2266					0, sizeof(u32), sizeof(loff_t)),
2267				si->imm);
2268			*insn++ = BPF_LDX_MEM(
2269				BPF_DW, treg, si->dst_reg,
2270				offsetof(struct bpf_sysctl_kern, tmp_reg));
2271		} else {
2272			*insn++ = BPF_LDX_MEM(
2273				BPF_FIELD_SIZEOF(struct bpf_sysctl_kern, ppos),
2274				si->dst_reg, si->src_reg,
2275				offsetof(struct bpf_sysctl_kern, ppos));
2276			read_size = bpf_size_to_bytes(BPF_SIZE(si->code));
2277			*insn++ = BPF_LDX_MEM(
2278				BPF_SIZE(si->code), si->dst_reg, si->dst_reg,
2279				bpf_ctx_narrow_access_offset(
2280					0, read_size, sizeof(loff_t)));
2281		}
2282		*target_size = sizeof(u32);
2283		break;
2284	}
2285
2286	return insn - insn_buf;
2287}
2288
2289const struct bpf_verifier_ops cg_sysctl_verifier_ops = {
2290	.get_func_proto		= sysctl_func_proto,
2291	.is_valid_access	= sysctl_is_valid_access,
2292	.convert_ctx_access	= sysctl_convert_ctx_access,
2293};
2294
2295const struct bpf_prog_ops cg_sysctl_prog_ops = {
2296};
2297
2298#ifdef CONFIG_NET
2299BPF_CALL_1(bpf_get_netns_cookie_sockopt, struct bpf_sockopt_kern *, ctx)
2300{
2301	const struct net *net = ctx ? sock_net(ctx->sk) : &init_net;
2302
2303	return net->net_cookie;
2304}
2305
2306static const struct bpf_func_proto bpf_get_netns_cookie_sockopt_proto = {
2307	.func		= bpf_get_netns_cookie_sockopt,
2308	.gpl_only	= false,
2309	.ret_type	= RET_INTEGER,
2310	.arg1_type	= ARG_PTR_TO_CTX_OR_NULL,
2311};
2312#endif
2313
2314static const struct bpf_func_proto *
2315cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
2316{
2317	const struct bpf_func_proto *func_proto;
2318
2319	func_proto = cgroup_common_func_proto(func_id, prog);
2320	if (func_proto)
2321		return func_proto;
2322
2323	func_proto = cgroup_current_func_proto(func_id, prog);
2324	if (func_proto)
2325		return func_proto;
2326
2327	switch (func_id) {
2328#ifdef CONFIG_NET
2329	case BPF_FUNC_get_netns_cookie:
2330		return &bpf_get_netns_cookie_sockopt_proto;
2331	case BPF_FUNC_sk_storage_get:
2332		return &bpf_sk_storage_get_proto;
2333	case BPF_FUNC_sk_storage_delete:
2334		return &bpf_sk_storage_delete_proto;
2335	case BPF_FUNC_setsockopt:
2336		if (prog->expected_attach_type == BPF_CGROUP_SETSOCKOPT)
2337			return &bpf_sk_setsockopt_proto;
2338		return NULL;
2339	case BPF_FUNC_getsockopt:
2340		if (prog->expected_attach_type == BPF_CGROUP_SETSOCKOPT)
2341			return &bpf_sk_getsockopt_proto;
2342		return NULL;
2343#endif
2344#ifdef CONFIG_INET
2345	case BPF_FUNC_tcp_sock:
2346		return &bpf_tcp_sock_proto;
2347#endif
2348	case BPF_FUNC_perf_event_output:
2349		return &bpf_event_output_data_proto;
2350	default:
2351		return bpf_base_func_proto(func_id);
2352	}
2353}
2354
2355static bool cg_sockopt_is_valid_access(int off, int size,
2356				       enum bpf_access_type type,
2357				       const struct bpf_prog *prog,
2358				       struct bpf_insn_access_aux *info)
2359{
2360	const int size_default = sizeof(__u32);
2361
2362	if (off < 0 || off >= sizeof(struct bpf_sockopt))
2363		return false;
2364
2365	if (off % size != 0)
2366		return false;
2367
2368	if (type == BPF_WRITE) {
2369		switch (off) {
2370		case offsetof(struct bpf_sockopt, retval):
2371			if (size != size_default)
2372				return false;
2373			return prog->expected_attach_type ==
2374				BPF_CGROUP_GETSOCKOPT;
2375		case offsetof(struct bpf_sockopt, optname):
2376			fallthrough;
2377		case offsetof(struct bpf_sockopt, level):
2378			if (size != size_default)
2379				return false;
2380			return prog->expected_attach_type ==
2381				BPF_CGROUP_SETSOCKOPT;
2382		case offsetof(struct bpf_sockopt, optlen):
2383			return size == size_default;
2384		default:
2385			return false;
2386		}
2387	}
2388
2389	switch (off) {
2390	case offsetof(struct bpf_sockopt, sk):
2391		if (size != sizeof(__u64))
2392			return false;
2393		info->reg_type = PTR_TO_SOCKET;
2394		break;
2395	case offsetof(struct bpf_sockopt, optval):
2396		if (size != sizeof(__u64))
2397			return false;
2398		info->reg_type = PTR_TO_PACKET;
2399		break;
2400	case offsetof(struct bpf_sockopt, optval_end):
2401		if (size != sizeof(__u64))
2402			return false;
2403		info->reg_type = PTR_TO_PACKET_END;
2404		break;
2405	case offsetof(struct bpf_sockopt, retval):
2406		if (size != size_default)
2407			return false;
2408		return prog->expected_attach_type == BPF_CGROUP_GETSOCKOPT;
2409	default:
2410		if (size != size_default)
2411			return false;
2412		break;
2413	}
2414	return true;
2415}
2416
2417#define CG_SOCKOPT_READ_FIELD(F)					\
2418	BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, F),	\
2419		    si->dst_reg, si->src_reg,				\
2420		    offsetof(struct bpf_sockopt_kern, F))
2421
2422#define CG_SOCKOPT_WRITE_FIELD(F)					\
2423	BPF_RAW_INSN((BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, F) |	\
2424		      BPF_MEM | BPF_CLASS(si->code)),			\
2425		     si->dst_reg, si->src_reg,				\
2426		     offsetof(struct bpf_sockopt_kern, F),		\
2427		     si->imm)
2428
2429static u32 cg_sockopt_convert_ctx_access(enum bpf_access_type type,
2430					 const struct bpf_insn *si,
2431					 struct bpf_insn *insn_buf,
2432					 struct bpf_prog *prog,
2433					 u32 *target_size)
2434{
2435	struct bpf_insn *insn = insn_buf;
2436
2437	switch (si->off) {
2438	case offsetof(struct bpf_sockopt, sk):
2439		*insn++ = CG_SOCKOPT_READ_FIELD(sk);
2440		break;
2441	case offsetof(struct bpf_sockopt, level):
2442		if (type == BPF_WRITE)
2443			*insn++ = CG_SOCKOPT_WRITE_FIELD(level);
2444		else
2445			*insn++ = CG_SOCKOPT_READ_FIELD(level);
2446		break;
2447	case offsetof(struct bpf_sockopt, optname):
2448		if (type == BPF_WRITE)
2449			*insn++ = CG_SOCKOPT_WRITE_FIELD(optname);
2450		else
2451			*insn++ = CG_SOCKOPT_READ_FIELD(optname);
2452		break;
2453	case offsetof(struct bpf_sockopt, optlen):
2454		if (type == BPF_WRITE)
2455			*insn++ = CG_SOCKOPT_WRITE_FIELD(optlen);
2456		else
2457			*insn++ = CG_SOCKOPT_READ_FIELD(optlen);
2458		break;
2459	case offsetof(struct bpf_sockopt, retval):
2460		BUILD_BUG_ON(offsetof(struct bpf_cg_run_ctx, run_ctx) != 0);
2461
2462		if (type == BPF_WRITE) {
2463			int treg = BPF_REG_9;
2464
2465			if (si->src_reg == treg || si->dst_reg == treg)
2466				--treg;
2467			if (si->src_reg == treg || si->dst_reg == treg)
2468				--treg;
2469			*insn++ = BPF_STX_MEM(BPF_DW, si->dst_reg, treg,
2470					      offsetof(struct bpf_sockopt_kern, tmp_reg));
2471			*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, current_task),
2472					      treg, si->dst_reg,
2473					      offsetof(struct bpf_sockopt_kern, current_task));
2474			*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct task_struct, bpf_ctx),
2475					      treg, treg,
2476					      offsetof(struct task_struct, bpf_ctx));
2477			*insn++ = BPF_RAW_INSN(BPF_CLASS(si->code) | BPF_MEM |
2478					       BPF_FIELD_SIZEOF(struct bpf_cg_run_ctx, retval),
2479					       treg, si->src_reg,
2480					       offsetof(struct bpf_cg_run_ctx, retval),
2481					       si->imm);
2482			*insn++ = BPF_LDX_MEM(BPF_DW, treg, si->dst_reg,
2483					      offsetof(struct bpf_sockopt_kern, tmp_reg));
2484		} else {
2485			*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, current_task),
2486					      si->dst_reg, si->src_reg,
2487					      offsetof(struct bpf_sockopt_kern, current_task));
2488			*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct task_struct, bpf_ctx),
2489					      si->dst_reg, si->dst_reg,
2490					      offsetof(struct task_struct, bpf_ctx));
2491			*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_cg_run_ctx, retval),
2492					      si->dst_reg, si->dst_reg,
2493					      offsetof(struct bpf_cg_run_ctx, retval));
2494		}
2495		break;
2496	case offsetof(struct bpf_sockopt, optval):
2497		*insn++ = CG_SOCKOPT_READ_FIELD(optval);
2498		break;
2499	case offsetof(struct bpf_sockopt, optval_end):
2500		*insn++ = CG_SOCKOPT_READ_FIELD(optval_end);
2501		break;
2502	}
2503
2504	return insn - insn_buf;
2505}
2506
2507static int cg_sockopt_get_prologue(struct bpf_insn *insn_buf,
2508				   bool direct_write,
2509				   const struct bpf_prog *prog)
2510{
2511	/* Nothing to do for sockopt argument. The data is kzalloc'ated.
2512	 */
2513	return 0;
2514}
2515
2516const struct bpf_verifier_ops cg_sockopt_verifier_ops = {
2517	.get_func_proto		= cg_sockopt_func_proto,
2518	.is_valid_access	= cg_sockopt_is_valid_access,
2519	.convert_ctx_access	= cg_sockopt_convert_ctx_access,
2520	.gen_prologue		= cg_sockopt_get_prologue,
2521};
2522
2523const struct bpf_prog_ops cg_sockopt_prog_ops = {
2524};
2525
2526/* Common helpers for cgroup hooks. */
2527const struct bpf_func_proto *
2528cgroup_common_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
2529{
2530	switch (func_id) {
2531	case BPF_FUNC_get_local_storage:
2532		return &bpf_get_local_storage_proto;
2533	case BPF_FUNC_get_retval:
2534		switch (prog->expected_attach_type) {
2535		case BPF_CGROUP_INET_INGRESS:
2536		case BPF_CGROUP_INET_EGRESS:
2537		case BPF_CGROUP_SOCK_OPS:
2538		case BPF_CGROUP_UDP4_RECVMSG:
2539		case BPF_CGROUP_UDP6_RECVMSG:
2540		case BPF_CGROUP_UNIX_RECVMSG:
2541		case BPF_CGROUP_INET4_GETPEERNAME:
2542		case BPF_CGROUP_INET6_GETPEERNAME:
2543		case BPF_CGROUP_UNIX_GETPEERNAME:
2544		case BPF_CGROUP_INET4_GETSOCKNAME:
2545		case BPF_CGROUP_INET6_GETSOCKNAME:
2546		case BPF_CGROUP_UNIX_GETSOCKNAME:
2547			return NULL;
2548		default:
2549			return &bpf_get_retval_proto;
2550		}
2551	case BPF_FUNC_set_retval:
2552		switch (prog->expected_attach_type) {
2553		case BPF_CGROUP_INET_INGRESS:
2554		case BPF_CGROUP_INET_EGRESS:
2555		case BPF_CGROUP_SOCK_OPS:
2556		case BPF_CGROUP_UDP4_RECVMSG:
2557		case BPF_CGROUP_UDP6_RECVMSG:
2558		case BPF_CGROUP_UNIX_RECVMSG:
2559		case BPF_CGROUP_INET4_GETPEERNAME:
2560		case BPF_CGROUP_INET6_GETPEERNAME:
2561		case BPF_CGROUP_UNIX_GETPEERNAME:
2562		case BPF_CGROUP_INET4_GETSOCKNAME:
2563		case BPF_CGROUP_INET6_GETSOCKNAME:
2564		case BPF_CGROUP_UNIX_GETSOCKNAME:
2565			return NULL;
2566		default:
2567			return &bpf_set_retval_proto;
2568		}
2569	default:
2570		return NULL;
2571	}
2572}
2573
2574/* Common helpers for cgroup hooks with valid process context. */
2575const struct bpf_func_proto *
2576cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
2577{
2578	switch (func_id) {
2579	case BPF_FUNC_get_current_uid_gid:
2580		return &bpf_get_current_uid_gid_proto;
2581	case BPF_FUNC_get_current_pid_tgid:
2582		return &bpf_get_current_pid_tgid_proto;
2583	case BPF_FUNC_get_current_comm:
2584		return &bpf_get_current_comm_proto;
2585#ifdef CONFIG_CGROUP_NET_CLASSID
2586	case BPF_FUNC_get_cgroup_classid:
2587		return &bpf_get_cgroup_classid_curr_proto;
2588#endif
 
 
2589	default:
2590		return NULL;
2591	}
2592}