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
24	DEFINE_STATIC_KEY_ARRAY_FALSE(cgroup_bpf_enabled_key, MAX_CGROUP_BPF_ATTACH_TYPE);
25	EXPORT_SYMBOL(cgroup_bpf_enabled_key);
26
27	/* __always_inline is necessary to prevent indirect call through run_prog
28	* function pointer.
29	*/
30	static __always_inline int
31	bpf_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(new_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_ctx: old_run_ctx);
61	rcu_read_unlock();
62	migrate_enable();
63	return run_ctx.retval;
64	}
65
66	unsigned 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(skcd: &sk->sk_cgrp_data);
81	if (likely(cgrp))
82	ret = bpf_prog_run_array_cg(cgrp: &cgrp->bpf,
83	atype: shim_prog->aux->cgroup_atype,
84	ctx, run_prog: bpf_prog_run, retval: 0, NULL);
85	return ret;
86	}
87
88	unsigned 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(skcd: &sock->sk->sk_cgrp_data);
103	if (likely(cgrp))
104	ret = bpf_prog_run_array_cg(cgrp: &cgrp->bpf,
105	atype: shim_prog->aux->cgroup_atype,
106	ctx, run_prog: bpf_prog_run, retval: 0, NULL);
107	return ret;
108	}
109
110	unsigned 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: &cgrp->bpf,
124	atype: shim_prog->aux->cgroup_atype,
125	ctx, run_prog: bpf_prog_run, retval: 0, NULL);
126	return ret;
127	}
128
129	#ifdef CONFIG_BPF_LSM
130	struct cgroup_lsm_atype {
131	u32 attach_btf_id;
132	int refcnt;
133	};
134
135	static struct cgroup_lsm_atype cgroup_lsm_atype[CGROUP_LSM_NUM];
136
137	static enum cgroup_bpf_attach_type
138	bpf_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
159	void 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
172	void 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
183	static enum cgroup_bpf_attach_type
184	bpf_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
192	void cgroup_bpf_offline(struct cgroup *cgrp)
193	{
194	cgroup_get(cgrp);
195	percpu_ref_kill(ref: &cgrp->bpf.refcnt);
196	}
197
198	static 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(storage: storages[stype]);
204	}
205
206	static 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(map: (void *)map, key: &key, locked: false);
225	if (storages[stype])
226	continue;
227
228	storages[stype] = bpf_cgroup_storage_alloc(prog, stype);
229	if (IS_ERR(ptr: storages[stype])) {
230	bpf_cgroup_storages_free(storages: new_storages);
231	return -ENOMEM;
232	}
233
234	new_storages[stype] = storages[stype];
235	}
236
237	return 0;
238	}
239
240	static 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
249	static 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(storage: storages[stype], cgroup: cgrp, type: 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	*/
264	static void bpf_cgroup_link_auto_detach(struct bpf_cgroup_link *link)
265	{
266	cgroup_put(cgrp: 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	*/
275	static 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(n: &pl->node);
294	if (pl->prog) {
295	if (pl->prog->expected_attach_type == BPF_LSM_CGROUP)
296	bpf_trampoline_unlink_cgroup_shim(prog: pl->prog);
297	bpf_prog_put(prog: 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(prog: pl->link->link.prog);
302	bpf_cgroup_link_auto_detach(link: pl->link);
303	}
304	kfree(objp: 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(progs: 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(cgrp: p))
321	cgroup_bpf_put(cgrp: p);
322
323	percpu_ref_exit(ref: &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	*/
332	static 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(wq: system_wq, work: &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	*/
343	static 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	*/
355	static 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	*/
372	static 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(head: &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(cgrp: 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	*/
401	static 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(head: &p->bpf.progs[atype]);
415	p = cgroup_parent(cgrp: p);
416	} while (p);
417
418	progs = bpf_prog_array_alloc(prog_cnt: 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(dst: item->cgroup_storage,
436	src: pl->storage);
437	cnt++;
438	}
439	} while ((p = cgroup_parent(cgrp: p)));
440
441	*array = progs;
442	return 0;
443	}
444
445	static 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(progs: old_array);
455	}
456
457	/**
458	* cgroup_bpf_inherit() - inherit effective programs from parent
459	* @cgrp: the cgroup to modify
460	*/
461	int 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(ref: &cgrp->bpf.refcnt, release: cgroup_bpf_release_fn, flags: 0,
472	GFP_KERNEL);
473	if (ret)
474	return ret;
475
476	for (p = cgroup_parent(cgrp); p; p = cgroup_parent(cgrp: p))
477	cgroup_bpf_get(cgrp: p);
478
479	for (i = 0; i < NR; i++)
480	INIT_HLIST_HEAD(&cgrp->bpf.progs[i]);
481
482	INIT_LIST_HEAD(list: &cgrp->bpf.storages);
483
484	for (i = 0; i < NR; i++)
485	if (compute_effective_progs(cgrp, atype: i, array: &arrays[i]))
486	goto cleanup;
487
488	for (i = 0; i < NR; i++)
489	activate_effective_progs(cgrp, atype: i, old_array: arrays[i]);
490
491	return 0;
492	cleanup:
493	for (i = 0; i < NR; i++)
494	bpf_prog_array_free(progs: arrays[i]);
495
496	for (p = cgroup_parent(cgrp); p; p = cgroup_parent(cgrp: p))
497	cgroup_bpf_put(cgrp: p);
498
499	percpu_ref_exit(ref: &cgrp->bpf.refcnt);
500
501	return -ENOMEM;
502	}
503
504	static 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(ref: &desc->bpf.refcnt))
515	continue;
516
517	err = compute_effective_progs(cgrp: desc, atype, array: &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(ref: &desc->bpf.refcnt)) {
527	if (unlikely(desc->bpf.inactive)) {
528	bpf_prog_array_free(progs: desc->bpf.inactive);
529	desc->bpf.inactive = NULL;
530	}
531	continue;
532	}
533
534	activate_effective_progs(cgrp: desc, atype, old_array: desc->bpf.inactive);
535	desc->bpf.inactive = NULL;
536	}
537
538	return 0;
539
540	cleanup:
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(progs: desc->bpf.inactive);
548	desc->bpf.inactive = NULL;
549	}
550
551	return err;
552	}
553
554	#define BPF_CGROUP_MAX_PROGS 64
555
556	static 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(h: 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(error: -EINVAL);
575	if (link && pl->link == link)
576	/* disallow attaching the same link twice */
577	return ERR_PTR(error: -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(error: -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	*/
607	static 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(attach_type: type, attach_btf_id: 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(h: 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(head: progs) >= BPF_CGROUP_MAX_PROGS)
650	return -E2BIG;
651
652	pl = find_attach_entry(progs, prog, link, replace_prog,
653	allow_multi: flags & BPF_F_ALLOW_MULTI);
654	if (IS_ERR(ptr: pl))
655	return PTR_ERR(ptr: pl);
656
657	if (bpf_cgroup_storages_alloc(storages: storage, new_storages: new_storage, type,
658	prog: 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(size: sizeof(*pl), GFP_KERNEL);
667	if (!pl) {
668	bpf_cgroup_storages_free(storages: new_storage);
669	return -ENOMEM;
670	}
671	if (hlist_empty(h: progs))
672	hlist_add_head(n: &pl->node, h: progs);
673	else
674	hlist_for_each(last, progs) {
675	if (last->next)
676	continue;
677	hlist_add_behind(n: &pl->node, prev: last);
678	break;
679	}
680	}
681
682	pl->prog = prog;
683	pl->link = link;
684	bpf_cgroup_storages_assign(dst: pl->storage, src: storage);
685	cgrp->bpf.flags[atype] = saved_flags;
686
687	if (type == BPF_LSM_CGROUP) {
688	err = bpf_trampoline_link_cgroup_shim(prog: new_prog, cgroup_atype: 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(prog: old_prog);
700	bpf_prog_put(prog: old_prog);
701	} else {
702	static_branch_inc(&cgroup_bpf_enabled_key[atype]);
703	}
704	bpf_cgroup_storages_link(storages: new_storage, cgrp, attach_type: type);
705	return 0;
706
707	cleanup_trampoline:
708	if (type == BPF_LSM_CGROUP)
709	bpf_trampoline_unlink_cgroup_shim(prog: new_prog);
710
711	cleanup:
712	if (old_prog) {
713	pl->prog = old_prog;
714	pl->link = NULL;
715	}
716	bpf_cgroup_storages_free(storages: new_storage);
717	if (!old_prog) {
718	hlist_del(n: &pl->node);
719	kfree(objp: pl);
720	}
721	return err;
722	}
723
724	static 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	*/
741	static 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(ref: &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(cgrp: 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	}
773	found:
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	*/
793	static 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(attach_type: link->type, attach_btf_id: 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(prog: old_prog);
824	return 0;
825	}
826
827	static 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(cgrp: cg_link->cgroup, link: cg_link, new_prog);
846	out_unlock:
847	cgroup_unlock();
848	return ret;
849	}
850
851	static 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(h: progs))
860	/* report error when trying to detach and nothing is attached */
861	return ERR_PTR(error: -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(error: -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(error: -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	*/
893	static 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(ref: &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(cgrp: 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;
928	found:
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	*/
950	static 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(attach_type: 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, allow_multi: flags & BPF_F_ALLOW_MULTI);
977	if (IS_ERR(ptr: pl))
978	return PTR_ERR(ptr: 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, prog: old_prog, link, atype);
990	}
991
992	/* now can actually delete it from this cgroup list */
993	hlist_del(n: &pl->node);
994
995	kfree(objp: pl);
996	if (hlist_empty(h: 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(prog: old_prog);
1002	bpf_prog_put(prog: old_prog);
1003	}
1004	static_branch_dec(&cgroup_bpf_enabled_key[atype]);
1005	return 0;
1006	}
1007
1008	static 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. */
1020	static 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(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(progs: effective);
1058	} else {
1059	total_cnt += prog_list_length(head: &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(to: &uattr->query.attach_flags, from: &flags, n: sizeof(flags)))
1066	return -EFAULT;
1067	if (copy_to_user(to: &uattr->query.prog_cnt, from: &total_cnt, n: 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(progs: 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(to: prog_ids + i, from: &id, n: 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(to: prog_attach_flags + i,
1107	from: &flags, n: 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
1119	static 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
1130	int 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(fd: attr->target_fd);
1138	if (IS_ERR(ptr: cgrp))
1139	return PTR_ERR(ptr: 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(ufd: attr->replace_bpf_fd, type: ptype);
1144	if (IS_ERR(ptr: replace_prog)) {
1145	cgroup_put(cgrp);
1146	return PTR_ERR(ptr: replace_prog);
1147	}
1148	}
1149
1150	ret = cgroup_bpf_attach(cgrp, prog, replace_prog, NULL,
1151	type: attr->attach_type, flags: attr->attach_flags);
1152
1153	if (replace_prog)
1154	bpf_prog_put(prog: replace_prog);
1155	cgroup_put(cgrp);
1156	return ret;
1157	}
1158
1159	int 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(fd: attr->target_fd);
1166	if (IS_ERR(ptr: cgrp))
1167	return PTR_ERR(ptr: cgrp);
1168
1169	prog = bpf_prog_get_type(ufd: attr->attach_bpf_fd, type: ptype);
1170	if (IS_ERR(ptr: prog))
1171	prog = NULL;
1172
1173	ret = cgroup_bpf_detach(cgrp, prog, type: attr->attach_type);
1174	if (prog)
1175	bpf_prog_put(prog);
1176
1177	cgroup_put(cgrp);
1178	return ret;
1179	}
1180
1181	static 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(prog: cg_link->link.prog);
1205
1206	cg = cg_link->cgroup;
1207	cg_link->cgroup = NULL;
1208
1209	cgroup_unlock();
1210
1211	cgroup_put(cgrp: cg);
1212	}
1213
1214	static 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(objp: cg_link);
1220	}
1221
1222	static int bpf_cgroup_link_detach(struct bpf_link *link)
1223	{
1224	bpf_cgroup_link_release(link);
1225
1226	return 0;
1227	}
1228
1229	static 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(cgrp: cg_link->cgroup);
1239	cgroup_unlock();
1240
1241	seq_printf(m: seq,
1242	fmt: "cgroup_id:\t%llu\n"
1243	"attach_type:\t%d\n",
1244	cg_id,
1245	cg_link->type);
1246	}
1247
1248	static 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(cgrp: 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
1265	static 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
1274	int 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(fd: attr->link_create.target_fd);
1285	if (IS_ERR(ptr: cgrp))
1286	return PTR_ERR(ptr: cgrp);
1287
1288	link = kzalloc(size: sizeof(*link), GFP_USER);
1289	if (!link) {
1290	err = -ENOMEM;
1291	goto out_put_cgroup;
1292	}
1293	bpf_link_init(link: &link->link, type: BPF_LINK_TYPE_CGROUP, ops: &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: &link_primer);
1299	if (err) {
1300	kfree(objp: link);
1301	goto out_put_cgroup;
1302	}
1303
1304	err = cgroup_bpf_attach(cgrp, NULL, NULL, link,
1305	type: link->type, BPF_F_ALLOW_MULTI);
1306	if (err) {
1307	bpf_link_cleanup(primer: &link_primer);
1308	goto out_put_cgroup;
1309	}
1310
1311	return bpf_link_settle(primer: &link_primer);
1312
1313	out_put_cgroup:
1314	cgroup_put(cgrp);
1315	return err;
1316	}
1317
1318	int 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(fd: attr->query.target_fd);
1325	if (IS_ERR(ptr: cgrp))
1326	return PTR_ERR(ptr: 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	*/
1357	int __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(skcd: &sk->sk_cgrp_data);
1374	save_sk = skb->sk;
1375	skb->sk = sk;
1376	__skb_push(skb, len: offset);
1377
1378	/* compute pointers for the bpf prog */
1379	bpf_compute_and_save_data_end(skb, saved_data_end: &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: &cgrp->bpf, atype, ctx: skb,
1386	run_prog: __bpf_prog_run_save_cb, retval: 0, ret_flags: &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: &cgrp->bpf, atype,
1412	ctx: skb, run_prog: __bpf_prog_run_save_cb, retval: 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, len: offset);
1419	skb->sk = save_sk;
1420
1421	return ret;
1422	}
1423	EXPORT_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	*/
1438	int __cgroup_bpf_run_filter_sk(struct sock *sk,
1439	enum cgroup_bpf_attach_type atype)
1440	{
1441	struct cgroup *cgrp = sock_cgroup_ptr(skcd: &sk->sk_cgrp_data);
1442
1443	return bpf_prog_run_array_cg(cgrp: &cgrp->bpf, atype, ctx: sk, run_prog: bpf_prog_run, retval: 0,
1444	NULL);
1445	}
1446	EXPORT_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	*/
1466	int __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(skcd: &sk->sk_cgrp_data);
1498	ret = bpf_prog_run_array_cg(cgrp: &cgrp->bpf, atype, ctx: &ctx, run_prog: bpf_prog_run,
1499	retval: 0, ret_flags: flags);
1500
1501	if (!ret && uaddr)
1502	*uaddrlen = ctx.uaddrlen;
1503
1504	return ret;
1505	}
1506	EXPORT_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	*/
1524	int __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(skcd: &sk->sk_cgrp_data);
1529
1530	return bpf_prog_run_array_cg(cgrp: &cgrp->bpf, atype, ctx: sock_ops, run_prog: bpf_prog_run,
1531	retval: 0, NULL);
1532	}
1533	EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_ops);
1534
1535	int __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: &cgrp->bpf, atype, ctx: &ctx, run_prog: bpf_prog_run, retval: 0,
1549	NULL);
1550	rcu_read_unlock();
1551
1552	return ret;
1553	}
1554
1555	BPF_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
1578	const 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
1586	BPF_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
1594	const struct bpf_func_proto bpf_get_retval_proto = {
1595	.func = bpf_get_retval,
1596	.gpl_only = false,
1597	.ret_type = RET_INTEGER,
1598	};
1599
1600	BPF_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
1609	const 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
1616	static const struct bpf_func_proto *
1617	cgroup_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
1637	static 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(aux: info, size: 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
1667	const struct bpf_prog_ops cg_dev_prog_ops = {
1668	};
1669
1670	const 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	*/
1696	int __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: &cgrp->bpf, atype, ctx: &ctx, run_prog: bpf_prog_run, retval: 0,
1740	NULL);
1741	rcu_read_unlock();
1742
1743	kfree(objp: ctx.cur_val);
1744
1745	if (ret == 1 && ctx.new_updated) {
1746	kfree(objp: *buf);
1747	*buf = ctx.new_val;
1748	*pcount = ctx.new_len;
1749	} else {
1750	kfree(objp: ctx.new_val);
1751	}
1752
1753	return ret;
1754	}
1755
1756	#ifdef CONFIG_NET
1757	static 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(size: 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
1788	static 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(objp: ctx->optval);
1794	}
1795
1796	static bool sockopt_buf_allocated(struct bpf_sockopt_kern *ctx,
1797	struct bpf_sockopt_buf *buf)
1798	{
1799	return ctx->optval != buf->data;
1800	}
1801
1802	int __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(skcd: &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: &ctx, max_optlen, buf: &buf);
1821	if (max_optlen < 0)
1822	return max_optlen;
1823
1824	ctx.optlen = *optlen;
1825
1826	if (copy_from_sockptr(dst: ctx.optval, src: 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: &cgrp->bpf, atype: CGROUP_SETSOCKOPT,
1834	ctx: &ctx, run_prog: bpf_prog_run, retval: 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: &ctx, buf: &buf)) {
1872	void *p = kmalloc(size: 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
1888	out:
1889	sockopt_free_buf(ctx: &ctx, buf: &buf);
1890	return ret;
1891	}
1892
1893	int __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(skcd: &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: &ctx, max_optlen, buf: &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(dst: &ctx.optlen, src: optlen,
1923	size: 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(dst: ctx.optval, src: 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: &cgrp->bpf, atype: CGROUP_GETSOCKOPT,
1943	ctx: &ctx, run_prog: bpf_prog_run, retval, NULL);
1944	release_sock(sk);
1945
1946	if (ret < 0)
1947	goto out;
1948
1949	if (!sockptr_is_null(sockptr: 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(sockptr: optval) &&
1963	copy_to_sockptr(dst: optval, src: ctx.optval, size: ctx.optlen)) {
1964	ret = -EFAULT;
1965	goto out;
1966	}
1967	if (copy_to_sockptr(dst: optlen, src: &ctx.optlen, size: sizeof(ctx.optlen))) {
1968	ret = -EFAULT;
1969	goto out;
1970	}
1971	}
1972
1973	out:
1974	sockopt_free_buf(ctx: &ctx, buf: &buf);
1975	return ret;
1976	}
1977
1978	int __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(skcd: &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: &cgrp->bpf, atype: CGROUP_GETSOCKOPT,
2003	ctx: &ctx, run_prog: 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
2019	static 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: dir->header.parent, bufp, lenp);
2026	if (tmp_ret < 0)
2027	return tmp_ret;
2028	}
2029
2030	ret = strscpy(p: *bufp, q: dir->header.ctl_table[0].procname, size: *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(p: *bufp, q: "/", size: *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
2050	BPF_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(dir: ctx->head->parent, bufp: &buf, lenp: &buf_len);
2062	if (tmp_ret < 0)
2063	return tmp_ret;
2064	}
2065
2066	ret = strscpy(p: buf, q: ctx->table->procname, size: buf_len);
2067
2068	return ret < 0 ? ret : tmp_ret + ret;
2069	}
2070
2071	static 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
2081	static 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
2107	BPF_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(dst: buf, dst_len: buf_len, src: ctx->cur_val, src_len: ctx->cur_len);
2111	}
2112
2113	static 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
2122	BPF_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(dst: buf, dst_len: buf_len, src: ctx->new_val, src_len: ctx->new_len);
2131	}
2132
2133	static 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
2142	BPF_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
2158	static 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
2167	static const struct bpf_func_proto *
2168	sysctl_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
2198	static 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(aux: info, size: 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(aux: info, size: 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
2225	static 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
2289	const 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
2295	const struct bpf_prog_ops cg_sysctl_prog_ops = {
2296	};
2297
2298	#ifdef CONFIG_NET
2299	BPF_CALL_1(bpf_get_netns_cookie_sockopt, struct bpf_sockopt_kern *, ctx)
2300	{
2301	const struct net *net = ctx ? sock_net(sk: ctx->sk) : &init_net;
2302
2303	return net->net_cookie;
2304	}
2305
2306	static 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
2314	static const struct bpf_func_proto *
2315	cg_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
2355	static 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
2429	static 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
2507	static 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
2516	const 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
2523	const struct bpf_prog_ops cg_sockopt_prog_ops = {
2524	};
2525
2526	/* Common helpers for cgroup hooks. */
2527	const struct bpf_func_proto *
2528	cgroup_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. */
2575	const struct bpf_func_proto *
2576	cgroup_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	}
2593