From 9d77db3c730780c8ef5ccd4b66403ff5675cfe4e Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 13 May 2024 10:30:14 +0000
Subject: [PATCH] modify sin led gpio
---
kernel/kernel/bpf/cgroup.c | 1566 ++++++++++++++++++++++++++++++++++++++++++++++++++++-----
1 files changed, 1,405 insertions(+), 161 deletions(-)
diff --git a/kernel/kernel/bpf/cgroup.c b/kernel/kernel/bpf/cgroup.c
index 6a7d931..d3593a5 100644
--- a/kernel/kernel/bpf/cgroup.c
+++ b/kernel/kernel/bpf/cgroup.c
@@ -1,46 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Functions to manage eBPF programs attached to cgroups
*
* Copyright (c) 2016 Daniel Mack
- *
- * This file is subject to the terms and conditions of version 2 of the GNU
- * General Public License. See the file COPYING in the main directory of the
- * Linux distribution for more details.
*/
#include <linux/kernel.h>
#include <linux/atomic.h>
#include <linux/cgroup.h>
+#include <linux/filter.h>
#include <linux/slab.h>
+#include <linux/sysctl.h>
+#include <linux/string.h>
#include <linux/bpf.h>
#include <linux/bpf-cgroup.h>
#include <net/sock.h>
+#include <net/bpf_sk_storage.h>
+
+#include "../cgroup/cgroup-internal.h"
DEFINE_STATIC_KEY_FALSE(cgroup_bpf_enabled_key);
EXPORT_SYMBOL(cgroup_bpf_enabled_key);
-/**
- * cgroup_bpf_put() - put references of all bpf programs
- * @cgrp: the cgroup to modify
- */
-void cgroup_bpf_put(struct cgroup *cgrp)
+void cgroup_bpf_offline(struct cgroup *cgrp)
{
+ cgroup_get(cgrp);
+ percpu_ref_kill(&cgrp->bpf.refcnt);
+}
+
+static void bpf_cgroup_storages_free(struct bpf_cgroup_storage *storages[])
+{
+ enum bpf_cgroup_storage_type stype;
+
+ for_each_cgroup_storage_type(stype)
+ bpf_cgroup_storage_free(storages[stype]);
+}
+
+static int bpf_cgroup_storages_alloc(struct bpf_cgroup_storage *storages[],
+ struct bpf_cgroup_storage *new_storages[],
+ enum bpf_attach_type type,
+ struct bpf_prog *prog,
+ struct cgroup *cgrp)
+{
+ enum bpf_cgroup_storage_type stype;
+ struct bpf_cgroup_storage_key key;
+ struct bpf_map *map;
+
+ key.cgroup_inode_id = cgroup_id(cgrp);
+ key.attach_type = type;
+
+ for_each_cgroup_storage_type(stype) {
+ map = prog->aux->cgroup_storage[stype];
+ if (!map)
+ continue;
+
+ storages[stype] = cgroup_storage_lookup((void *)map, &key, false);
+ if (storages[stype])
+ continue;
+
+ storages[stype] = bpf_cgroup_storage_alloc(prog, stype);
+ if (IS_ERR(storages[stype])) {
+ bpf_cgroup_storages_free(new_storages);
+ return -ENOMEM;
+ }
+
+ new_storages[stype] = storages[stype];
+ }
+
+ return 0;
+}
+
+static void bpf_cgroup_storages_assign(struct bpf_cgroup_storage *dst[],
+ struct bpf_cgroup_storage *src[])
+{
+ enum bpf_cgroup_storage_type stype;
+
+ for_each_cgroup_storage_type(stype)
+ dst[stype] = src[stype];
+}
+
+static void bpf_cgroup_storages_link(struct bpf_cgroup_storage *storages[],
+ struct cgroup *cgrp,
+ enum bpf_attach_type attach_type)
+{
+ enum bpf_cgroup_storage_type stype;
+
+ for_each_cgroup_storage_type(stype)
+ bpf_cgroup_storage_link(storages[stype], cgrp, attach_type);
+}
+
+/* Called when bpf_cgroup_link is auto-detached from dying cgroup.
+ * It drops cgroup and bpf_prog refcounts, and marks bpf_link as defunct. It
+ * doesn't free link memory, which will eventually be done by bpf_link's
+ * release() callback, when its last FD is closed.
+ */
+static void bpf_cgroup_link_auto_detach(struct bpf_cgroup_link *link)
+{
+ cgroup_put(link->cgroup);
+ link->cgroup = NULL;
+}
+
+/**
+ * cgroup_bpf_release() - put references of all bpf programs and
+ * release all cgroup bpf data
+ * @work: work structure embedded into the cgroup to modify
+ */
+static void cgroup_bpf_release(struct work_struct *work)
+{
+ struct cgroup *p, *cgrp = container_of(work, struct cgroup,
+ bpf.release_work);
+ struct bpf_prog_array *old_array;
+ struct list_head *storages = &cgrp->bpf.storages;
+ struct bpf_cgroup_storage *storage, *stmp;
+
unsigned int type;
+
+ mutex_lock(&cgroup_mutex);
for (type = 0; type < ARRAY_SIZE(cgrp->bpf.progs); type++) {
struct list_head *progs = &cgrp->bpf.progs[type];
- struct bpf_prog_list *pl, *tmp;
+ struct bpf_prog_list *pl, *pltmp;
- list_for_each_entry_safe(pl, tmp, progs, node) {
+ list_for_each_entry_safe(pl, pltmp, progs, node) {
list_del(&pl->node);
- bpf_prog_put(pl->prog);
- bpf_cgroup_storage_unlink(pl->storage);
- bpf_cgroup_storage_free(pl->storage);
+ if (pl->prog)
+ bpf_prog_put(pl->prog);
+ if (pl->link)
+ bpf_cgroup_link_auto_detach(pl->link);
kfree(pl);
static_branch_dec(&cgroup_bpf_enabled_key);
}
- bpf_prog_array_free(cgrp->bpf.effective[type]);
+ old_array = rcu_dereference_protected(
+ cgrp->bpf.effective[type],
+ lockdep_is_held(&cgroup_mutex));
+ bpf_prog_array_free(old_array);
}
+
+ list_for_each_entry_safe(storage, stmp, storages, list_cg) {
+ bpf_cgroup_storage_unlink(storage);
+ bpf_cgroup_storage_free(storage);
+ }
+
+ mutex_unlock(&cgroup_mutex);
+
+ for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
+ cgroup_bpf_put(p);
+
+ percpu_ref_exit(&cgrp->bpf.refcnt);
+ cgroup_put(cgrp);
+}
+
+/**
+ * cgroup_bpf_release_fn() - callback used to schedule releasing
+ * of bpf cgroup data
+ * @ref: percpu ref counter structure
+ */
+static void cgroup_bpf_release_fn(struct percpu_ref *ref)
+{
+ struct cgroup *cgrp = container_of(ref, struct cgroup, bpf.refcnt);
+
+ INIT_WORK(&cgrp->bpf.release_work, cgroup_bpf_release);
+ queue_work(system_wq, &cgrp->bpf.release_work);
+}
+
+/* Get underlying bpf_prog of bpf_prog_list entry, regardless if it's through
+ * link or direct prog.
+ */
+static struct bpf_prog *prog_list_prog(struct bpf_prog_list *pl)
+{
+ if (pl->prog)
+ return pl->prog;
+ if (pl->link)
+ return pl->link->link.prog;
+ return NULL;
}
/* count number of elements in the list.
@@ -52,7 +184,7 @@
u32 cnt = 0;
list_for_each_entry(pl, head, node) {
- if (!pl->prog)
+ if (!prog_list_prog(pl))
continue;
cnt++;
}
@@ -64,8 +196,7 @@
* if parent has overridable or multi-prog, allow attaching
*/
static bool hierarchy_allows_attach(struct cgroup *cgrp,
- enum bpf_attach_type type,
- u32 new_flags)
+ enum bpf_attach_type type)
{
struct cgroup *p;
@@ -95,8 +226,9 @@
*/
static int compute_effective_progs(struct cgroup *cgrp,
enum bpf_attach_type type,
- struct bpf_prog_array __rcu **array)
+ struct bpf_prog_array **array)
{
+ struct bpf_prog_array_item *item;
struct bpf_prog_array *progs;
struct bpf_prog_list *pl;
struct cgroup *p = cgrp;
@@ -121,26 +253,27 @@
continue;
list_for_each_entry(pl, &p->bpf.progs[type], node) {
- if (!pl->prog)
+ if (!prog_list_prog(pl))
continue;
- progs->items[cnt].prog = pl->prog;
- progs->items[cnt].cgroup_storage = pl->storage;
+ item = &progs->items[cnt];
+ item->prog = prog_list_prog(pl);
+ bpf_cgroup_storages_assign(item->cgroup_storage,
+ pl->storage);
cnt++;
}
} while ((p = cgroup_parent(p)));
- rcu_assign_pointer(*array, progs);
+ *array = progs;
return 0;
}
static void activate_effective_progs(struct cgroup *cgrp,
enum bpf_attach_type type,
- struct bpf_prog_array __rcu *array)
+ struct bpf_prog_array *old_array)
{
- struct bpf_prog_array __rcu *old_array;
-
- old_array = xchg(&cgrp->bpf.effective[type], array);
+ old_array = rcu_replace_pointer(cgrp->bpf.effective[type], old_array,
+ lockdep_is_held(&cgroup_mutex));
/* free prog array after grace period, since __cgroup_bpf_run_*()
* might be still walking the array
*/
@@ -157,11 +290,22 @@
* that array below is variable length
*/
#define NR ARRAY_SIZE(cgrp->bpf.effective)
- struct bpf_prog_array __rcu *arrays[NR] = {};
- int i;
+ struct bpf_prog_array *arrays[NR] = {};
+ struct cgroup *p;
+ int ret, i;
+
+ ret = percpu_ref_init(&cgrp->bpf.refcnt, cgroup_bpf_release_fn, 0,
+ GFP_KERNEL);
+ if (ret)
+ return ret;
+
+ for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
+ cgroup_bpf_get(p);
for (i = 0; i < NR; i++)
INIT_LIST_HEAD(&cgrp->bpf.progs[i]);
+
+ INIT_LIST_HEAD(&cgrp->bpf.storages);
for (i = 0; i < NR; i++)
if (compute_effective_progs(cgrp, i, &arrays[i]))
@@ -174,6 +318,12 @@
cleanup:
for (i = 0; i < NR; i++)
bpf_prog_array_free(arrays[i]);
+
+ for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
+ cgroup_bpf_put(p);
+
+ percpu_ref_exit(&cgrp->bpf.refcnt);
+
return -ENOMEM;
}
@@ -187,6 +337,9 @@
css_for_each_descendant_pre(css, &cgrp->self) {
struct cgroup *desc = container_of(css, struct cgroup, self);
+ if (percpu_ref_is_zero(&desc->bpf.refcnt))
+ continue;
+
err = compute_effective_progs(desc, type, &desc->bpf.inactive);
if (err)
goto cleanup;
@@ -195,6 +348,14 @@
/* all allocations were successful. Activate all prog arrays */
css_for_each_descendant_pre(css, &cgrp->self) {
struct cgroup *desc = container_of(css, struct cgroup, self);
+
+ if (percpu_ref_is_zero(&desc->bpf.refcnt)) {
+ if (unlikely(desc->bpf.inactive)) {
+ bpf_prog_array_free(desc->bpf.inactive);
+ desc->bpf.inactive = NULL;
+ }
+ continue;
+ }
activate_effective_progs(desc, type, desc->bpf.inactive);
desc->bpf.inactive = NULL;
@@ -218,33 +379,85 @@
#define BPF_CGROUP_MAX_PROGS 64
+static struct bpf_prog_list *find_attach_entry(struct list_head *progs,
+ struct bpf_prog *prog,
+ struct bpf_cgroup_link *link,
+ struct bpf_prog *replace_prog,
+ bool allow_multi)
+{
+ struct bpf_prog_list *pl;
+
+ /* single-attach case */
+ if (!allow_multi) {
+ if (list_empty(progs))
+ return NULL;
+ return list_first_entry(progs, typeof(*pl), node);
+ }
+
+ list_for_each_entry(pl, progs, node) {
+ if (prog && pl->prog == prog && prog != replace_prog)
+ /* disallow attaching the same prog twice */
+ return ERR_PTR(-EINVAL);
+ if (link && pl->link == link)
+ /* disallow attaching the same link twice */
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* direct prog multi-attach w/ replacement case */
+ if (replace_prog) {
+ list_for_each_entry(pl, progs, node) {
+ if (pl->prog == replace_prog)
+ /* a match found */
+ return pl;
+ }
+ /* prog to replace not found for cgroup */
+ return ERR_PTR(-ENOENT);
+ }
+
+ return NULL;
+}
+
/**
- * __cgroup_bpf_attach() - Attach the program to a cgroup, and
+ * __cgroup_bpf_attach() - Attach the program or the link to a cgroup, and
* propagate the change to descendants
* @cgrp: The cgroup which descendants to traverse
* @prog: A program to attach
+ * @link: A link to attach
+ * @replace_prog: Previously attached program to replace if BPF_F_REPLACE is set
* @type: Type of attach operation
+ * @flags: Option flags
*
+ * Exactly one of @prog or @link can be non-null.
* Must be called with cgroup_mutex held.
*/
-int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
+int __cgroup_bpf_attach(struct cgroup *cgrp,
+ struct bpf_prog *prog, struct bpf_prog *replace_prog,
+ struct bpf_cgroup_link *link,
enum bpf_attach_type type, u32 flags)
{
+ u32 saved_flags = (flags & (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI));
struct list_head *progs = &cgrp->bpf.progs[type];
struct bpf_prog *old_prog = NULL;
- struct bpf_cgroup_storage *storage, *old_storage = NULL;
+ struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
+ struct bpf_cgroup_storage *new_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
struct bpf_prog_list *pl;
- bool pl_was_allocated;
int err;
- if ((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI))
+ if (((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI)) ||
+ ((flags & BPF_F_REPLACE) && !(flags & BPF_F_ALLOW_MULTI)))
/* invalid combination */
return -EINVAL;
+ if (link && (prog || replace_prog))
+ /* only either link or prog/replace_prog can be specified */
+ return -EINVAL;
+ if (!!replace_prog != !!(flags & BPF_F_REPLACE))
+ /* replace_prog implies BPF_F_REPLACE, and vice versa */
+ return -EINVAL;
- if (!hierarchy_allows_attach(cgrp, type, flags))
+ if (!hierarchy_allows_attach(cgrp, type))
return -EPERM;
- if (!list_empty(progs) && cgrp->bpf.flags[type] != flags)
+ if (!list_empty(progs) && cgrp->bpf.flags[type] != saved_flags)
/* Disallow attaching non-overridable on top
* of existing overridable in this cgroup.
* Disallow attaching multi-prog if overridable or none
@@ -254,152 +467,297 @@
if (prog_list_length(progs) >= BPF_CGROUP_MAX_PROGS)
return -E2BIG;
- storage = bpf_cgroup_storage_alloc(prog);
- if (IS_ERR(storage))
+ pl = find_attach_entry(progs, prog, link, replace_prog,
+ flags & BPF_F_ALLOW_MULTI);
+ if (IS_ERR(pl))
+ return PTR_ERR(pl);
+
+ if (bpf_cgroup_storages_alloc(storage, new_storage, type,
+ prog ? : link->link.prog, cgrp))
return -ENOMEM;
- if (flags & BPF_F_ALLOW_MULTI) {
- list_for_each_entry(pl, progs, node) {
- if (pl->prog == prog) {
- /* disallow attaching the same prog twice */
- bpf_cgroup_storage_free(storage);
- return -EINVAL;
- }
- }
-
+ if (pl) {
+ old_prog = pl->prog;
+ } else {
pl = kmalloc(sizeof(*pl), GFP_KERNEL);
if (!pl) {
- bpf_cgroup_storage_free(storage);
+ bpf_cgroup_storages_free(new_storage);
return -ENOMEM;
}
-
- pl_was_allocated = true;
- pl->prog = prog;
- pl->storage = storage;
list_add_tail(&pl->node, progs);
- } else {
- if (list_empty(progs)) {
- pl = kmalloc(sizeof(*pl), GFP_KERNEL);
- if (!pl) {
- bpf_cgroup_storage_free(storage);
- return -ENOMEM;
- }
- pl_was_allocated = true;
- list_add_tail(&pl->node, progs);
- } else {
- pl = list_first_entry(progs, typeof(*pl), node);
- old_prog = pl->prog;
- old_storage = pl->storage;
- bpf_cgroup_storage_unlink(old_storage);
- pl_was_allocated = false;
- }
- pl->prog = prog;
- pl->storage = storage;
}
- cgrp->bpf.flags[type] = flags;
+ pl->prog = prog;
+ pl->link = link;
+ bpf_cgroup_storages_assign(pl->storage, storage);
+ cgrp->bpf.flags[type] = saved_flags;
err = update_effective_progs(cgrp, type);
if (err)
goto cleanup;
- static_branch_inc(&cgroup_bpf_enabled_key);
- if (old_storage)
- bpf_cgroup_storage_free(old_storage);
- if (old_prog) {
+ if (old_prog)
bpf_prog_put(old_prog);
- static_branch_dec(&cgroup_bpf_enabled_key);
- }
- bpf_cgroup_storage_link(storage, cgrp, type);
+ else
+ static_branch_inc(&cgroup_bpf_enabled_key);
+ bpf_cgroup_storages_link(new_storage, cgrp, type);
return 0;
cleanup:
- /* and cleanup the prog list */
- pl->prog = old_prog;
- bpf_cgroup_storage_free(pl->storage);
- pl->storage = old_storage;
- bpf_cgroup_storage_link(old_storage, cgrp, type);
- if (pl_was_allocated) {
+ if (old_prog) {
+ pl->prog = old_prog;
+ pl->link = NULL;
+ }
+ bpf_cgroup_storages_free(new_storage);
+ if (!old_prog) {
list_del(&pl->node);
kfree(pl);
}
return err;
}
+/* Swap updated BPF program for given link in effective program arrays across
+ * all descendant cgroups. This function is guaranteed to succeed.
+ */
+static void replace_effective_prog(struct cgroup *cgrp,
+ enum bpf_attach_type type,
+ struct bpf_cgroup_link *link)
+{
+ struct bpf_prog_array_item *item;
+ struct cgroup_subsys_state *css;
+ struct bpf_prog_array *progs;
+ struct bpf_prog_list *pl;
+ struct list_head *head;
+ struct cgroup *cg;
+ int pos;
+
+ css_for_each_descendant_pre(css, &cgrp->self) {
+ struct cgroup *desc = container_of(css, struct cgroup, self);
+
+ if (percpu_ref_is_zero(&desc->bpf.refcnt))
+ continue;
+
+ /* find position of link in effective progs array */
+ for (pos = 0, cg = desc; cg; cg = cgroup_parent(cg)) {
+ if (pos && !(cg->bpf.flags[type] & BPF_F_ALLOW_MULTI))
+ continue;
+
+ head = &cg->bpf.progs[type];
+ list_for_each_entry(pl, head, node) {
+ if (!prog_list_prog(pl))
+ continue;
+ if (pl->link == link)
+ goto found;
+ pos++;
+ }
+ }
+found:
+ BUG_ON(!cg);
+ progs = rcu_dereference_protected(
+ desc->bpf.effective[type],
+ lockdep_is_held(&cgroup_mutex));
+ item = &progs->items[pos];
+ WRITE_ONCE(item->prog, link->link.prog);
+ }
+}
+
/**
- * __cgroup_bpf_detach() - Detach the program from a cgroup, and
- * propagate the change to descendants
+ * __cgroup_bpf_replace() - Replace link's program and propagate the change
+ * to descendants
* @cgrp: The cgroup which descendants to traverse
- * @prog: A program to detach or NULL
- * @type: Type of detach operation
+ * @link: A link for which to replace BPF program
+ * @type: Type of attach operation
*
* Must be called with cgroup_mutex held.
*/
+static int __cgroup_bpf_replace(struct cgroup *cgrp,
+ struct bpf_cgroup_link *link,
+ struct bpf_prog *new_prog)
+{
+ struct list_head *progs = &cgrp->bpf.progs[link->type];
+ struct bpf_prog *old_prog;
+ struct bpf_prog_list *pl;
+ bool found = false;
+
+ if (link->link.prog->type != new_prog->type)
+ return -EINVAL;
+
+ list_for_each_entry(pl, progs, node) {
+ if (pl->link == link) {
+ found = true;
+ break;
+ }
+ }
+ if (!found)
+ return -ENOENT;
+
+ old_prog = xchg(&link->link.prog, new_prog);
+ replace_effective_prog(cgrp, link->type, link);
+ bpf_prog_put(old_prog);
+ return 0;
+}
+
+static int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *new_prog,
+ struct bpf_prog *old_prog)
+{
+ struct bpf_cgroup_link *cg_link;
+ int ret;
+
+ cg_link = container_of(link, struct bpf_cgroup_link, link);
+
+ mutex_lock(&cgroup_mutex);
+ /* link might have been auto-released by dying cgroup, so fail */
+ if (!cg_link->cgroup) {
+ ret = -ENOLINK;
+ goto out_unlock;
+ }
+ if (old_prog && link->prog != old_prog) {
+ ret = -EPERM;
+ goto out_unlock;
+ }
+ ret = __cgroup_bpf_replace(cg_link->cgroup, cg_link, new_prog);
+out_unlock:
+ mutex_unlock(&cgroup_mutex);
+ return ret;
+}
+
+static struct bpf_prog_list *find_detach_entry(struct list_head *progs,
+ struct bpf_prog *prog,
+ struct bpf_cgroup_link *link,
+ bool allow_multi)
+{
+ struct bpf_prog_list *pl;
+
+ if (!allow_multi) {
+ if (list_empty(progs))
+ /* report error when trying to detach and nothing is attached */
+ return ERR_PTR(-ENOENT);
+
+ /* to maintain backward compatibility NONE and OVERRIDE cgroups
+ * allow detaching with invalid FD (prog==NULL) in legacy mode
+ */
+ return list_first_entry(progs, typeof(*pl), node);
+ }
+
+ if (!prog && !link)
+ /* to detach MULTI prog the user has to specify valid FD
+ * of the program or link to be detached
+ */
+ return ERR_PTR(-EINVAL);
+
+ /* find the prog or link and detach it */
+ list_for_each_entry(pl, progs, node) {
+ if (pl->prog == prog && pl->link == link)
+ return pl;
+ }
+ return ERR_PTR(-ENOENT);
+}
+
+/**
+ * purge_effective_progs() - After compute_effective_progs fails to alloc new
+ * cgrp->bpf.inactive table we can recover by
+ * recomputing the array in place.
+ *
+ * @cgrp: The cgroup which descendants to travers
+ * @prog: A program to detach or NULL
+ * @link: A link to detach or NULL
+ * @type: Type of detach operation
+ */
+static void purge_effective_progs(struct cgroup *cgrp, struct bpf_prog *prog,
+ struct bpf_cgroup_link *link,
+ enum bpf_attach_type type)
+{
+ struct cgroup_subsys_state *css;
+ struct bpf_prog_array *progs;
+ struct bpf_prog_list *pl;
+ struct list_head *head;
+ struct cgroup *cg;
+ int pos;
+
+ /* recompute effective prog array in place */
+ css_for_each_descendant_pre(css, &cgrp->self) {
+ struct cgroup *desc = container_of(css, struct cgroup, self);
+
+ if (percpu_ref_is_zero(&desc->bpf.refcnt))
+ continue;
+
+ /* find position of link or prog in effective progs array */
+ for (pos = 0, cg = desc; cg; cg = cgroup_parent(cg)) {
+ if (pos && !(cg->bpf.flags[type] & BPF_F_ALLOW_MULTI))
+ continue;
+
+ head = &cg->bpf.progs[type];
+ list_for_each_entry(pl, head, node) {
+ if (!prog_list_prog(pl))
+ continue;
+ if (pl->prog == prog && pl->link == link)
+ goto found;
+ pos++;
+ }
+ }
+
+ /* no link or prog match, skip the cgroup of this layer */
+ continue;
+found:
+ progs = rcu_dereference_protected(
+ desc->bpf.effective[type],
+ lockdep_is_held(&cgroup_mutex));
+
+ /* Remove the program from the array */
+ WARN_ONCE(bpf_prog_array_delete_safe_at(progs, pos),
+ "Failed to purge a prog from array at index %d", pos);
+ }
+}
+
+/**
+ * __cgroup_bpf_detach() - Detach the program or link from a cgroup, and
+ * propagate the change to descendants
+ * @cgrp: The cgroup which descendants to traverse
+ * @prog: A program to detach or NULL
+ * @prog: A link to detach or NULL
+ * @type: Type of detach operation
+ *
+ * At most one of @prog or @link can be non-NULL.
+ * Must be called with cgroup_mutex held.
+ */
int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
- enum bpf_attach_type type, u32 unused_flags)
+ struct bpf_cgroup_link *link, enum bpf_attach_type type)
{
struct list_head *progs = &cgrp->bpf.progs[type];
u32 flags = cgrp->bpf.flags[type];
- struct bpf_prog *old_prog = NULL;
struct bpf_prog_list *pl;
- int err;
+ struct bpf_prog *old_prog;
- if (flags & BPF_F_ALLOW_MULTI) {
- if (!prog)
- /* to detach MULTI prog the user has to specify valid FD
- * of the program to be detached
- */
- return -EINVAL;
- } else {
- if (list_empty(progs))
- /* report error when trying to detach and nothing is attached */
- return -ENOENT;
+ if (prog && link)
+ /* only one of prog or link can be specified */
+ return -EINVAL;
+
+ pl = find_detach_entry(progs, prog, link, flags & BPF_F_ALLOW_MULTI);
+ if (IS_ERR(pl))
+ return PTR_ERR(pl);
+
+ /* mark it deleted, so it's ignored while recomputing effective */
+ old_prog = pl->prog;
+ pl->prog = NULL;
+ pl->link = NULL;
+
+ if (update_effective_progs(cgrp, type)) {
+ /* if update effective array failed replace the prog with a dummy prog*/
+ pl->prog = old_prog;
+ pl->link = link;
+ purge_effective_progs(cgrp, old_prog, link, type);
}
-
- if (flags & BPF_F_ALLOW_MULTI) {
- /* find the prog and detach it */
- list_for_each_entry(pl, progs, node) {
- if (pl->prog != prog)
- continue;
- old_prog = prog;
- /* mark it deleted, so it's ignored while
- * recomputing effective
- */
- pl->prog = NULL;
- break;
- }
- if (!old_prog)
- return -ENOENT;
- } else {
- /* to maintain backward compatibility NONE and OVERRIDE cgroups
- * allow detaching with invalid FD (prog==NULL)
- */
- pl = list_first_entry(progs, typeof(*pl), node);
- old_prog = pl->prog;
- pl->prog = NULL;
- }
-
- err = update_effective_progs(cgrp, type);
- if (err)
- goto cleanup;
/* now can actually delete it from this cgroup list */
list_del(&pl->node);
- bpf_cgroup_storage_unlink(pl->storage);
- bpf_cgroup_storage_free(pl->storage);
kfree(pl);
if (list_empty(progs))
/* last program was detached, reset flags to zero */
cgrp->bpf.flags[type] = 0;
-
- bpf_prog_put(old_prog);
+ if (old_prog)
+ bpf_prog_put(old_prog);
static_branch_dec(&cgroup_bpf_enabled_key);
return 0;
-
-cleanup:
- /* and restore back old_prog */
- pl->prog = old_prog;
- return err;
}
/* Must be called with cgroup_mutex held to avoid races. */
@@ -410,10 +768,15 @@
enum bpf_attach_type type = attr->query.attach_type;
struct list_head *progs = &cgrp->bpf.progs[type];
u32 flags = cgrp->bpf.flags[type];
+ struct bpf_prog_array *effective;
+ struct bpf_prog *prog;
int cnt, ret = 0, i;
+ effective = rcu_dereference_protected(cgrp->bpf.effective[type],
+ lockdep_is_held(&cgroup_mutex));
+
if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE)
- cnt = bpf_prog_array_length(cgrp->bpf.effective[type]);
+ cnt = bpf_prog_array_length(effective);
else
cnt = prog_list_length(progs);
@@ -430,15 +793,15 @@
}
if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) {
- return bpf_prog_array_copy_to_user(cgrp->bpf.effective[type],
- prog_ids, cnt);
+ return bpf_prog_array_copy_to_user(effective, prog_ids, cnt);
} else {
struct bpf_prog_list *pl;
u32 id;
i = 0;
list_for_each_entry(pl, progs, node) {
- id = pl->prog->aux->id;
+ prog = prog_list_prog(pl);
+ id = prog->aux->id;
if (copy_to_user(prog_ids + i, &id, sizeof(id)))
return -EFAULT;
if (++i == cnt)
@@ -451,6 +814,7 @@
int cgroup_bpf_prog_attach(const union bpf_attr *attr,
enum bpf_prog_type ptype, struct bpf_prog *prog)
{
+ struct bpf_prog *replace_prog = NULL;
struct cgroup *cgrp;
int ret;
@@ -458,8 +822,20 @@
if (IS_ERR(cgrp))
return PTR_ERR(cgrp);
- ret = cgroup_bpf_attach(cgrp, prog, attr->attach_type,
- attr->attach_flags);
+ if ((attr->attach_flags & BPF_F_ALLOW_MULTI) &&
+ (attr->attach_flags & BPF_F_REPLACE)) {
+ replace_prog = bpf_prog_get_type(attr->replace_bpf_fd, ptype);
+ if (IS_ERR(replace_prog)) {
+ cgroup_put(cgrp);
+ return PTR_ERR(replace_prog);
+ }
+ }
+
+ ret = cgroup_bpf_attach(cgrp, prog, replace_prog, NULL,
+ attr->attach_type, attr->attach_flags);
+
+ if (replace_prog)
+ bpf_prog_put(replace_prog);
cgroup_put(cgrp);
return ret;
}
@@ -478,12 +854,147 @@
if (IS_ERR(prog))
prog = NULL;
- ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type, 0);
+ ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type);
if (prog)
bpf_prog_put(prog);
cgroup_put(cgrp);
return ret;
+}
+
+static void bpf_cgroup_link_release(struct bpf_link *link)
+{
+ struct bpf_cgroup_link *cg_link =
+ container_of(link, struct bpf_cgroup_link, link);
+ struct cgroup *cg;
+
+ /* link might have been auto-detached by dying cgroup already,
+ * in that case our work is done here
+ */
+ if (!cg_link->cgroup)
+ return;
+
+ mutex_lock(&cgroup_mutex);
+
+ /* re-check cgroup under lock again */
+ if (!cg_link->cgroup) {
+ mutex_unlock(&cgroup_mutex);
+ return;
+ }
+
+ WARN_ON(__cgroup_bpf_detach(cg_link->cgroup, NULL, cg_link,
+ cg_link->type));
+
+ cg = cg_link->cgroup;
+ cg_link->cgroup = NULL;
+
+ mutex_unlock(&cgroup_mutex);
+
+ cgroup_put(cg);
+}
+
+static void bpf_cgroup_link_dealloc(struct bpf_link *link)
+{
+ struct bpf_cgroup_link *cg_link =
+ container_of(link, struct bpf_cgroup_link, link);
+
+ kfree(cg_link);
+}
+
+static int bpf_cgroup_link_detach(struct bpf_link *link)
+{
+ bpf_cgroup_link_release(link);
+
+ return 0;
+}
+
+static void bpf_cgroup_link_show_fdinfo(const struct bpf_link *link,
+ struct seq_file *seq)
+{
+ struct bpf_cgroup_link *cg_link =
+ container_of(link, struct bpf_cgroup_link, link);
+ u64 cg_id = 0;
+
+ mutex_lock(&cgroup_mutex);
+ if (cg_link->cgroup)
+ cg_id = cgroup_id(cg_link->cgroup);
+ mutex_unlock(&cgroup_mutex);
+
+ seq_printf(seq,
+ "cgroup_id:\t%llu\n"
+ "attach_type:\t%d\n",
+ cg_id,
+ cg_link->type);
+}
+
+static int bpf_cgroup_link_fill_link_info(const struct bpf_link *link,
+ struct bpf_link_info *info)
+{
+ struct bpf_cgroup_link *cg_link =
+ container_of(link, struct bpf_cgroup_link, link);
+ u64 cg_id = 0;
+
+ mutex_lock(&cgroup_mutex);
+ if (cg_link->cgroup)
+ cg_id = cgroup_id(cg_link->cgroup);
+ mutex_unlock(&cgroup_mutex);
+
+ info->cgroup.cgroup_id = cg_id;
+ info->cgroup.attach_type = cg_link->type;
+ return 0;
+}
+
+static const struct bpf_link_ops bpf_cgroup_link_lops = {
+ .release = bpf_cgroup_link_release,
+ .dealloc = bpf_cgroup_link_dealloc,
+ .detach = bpf_cgroup_link_detach,
+ .update_prog = cgroup_bpf_replace,
+ .show_fdinfo = bpf_cgroup_link_show_fdinfo,
+ .fill_link_info = bpf_cgroup_link_fill_link_info,
+};
+
+int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+ struct bpf_link_primer link_primer;
+ struct bpf_cgroup_link *link;
+ struct cgroup *cgrp;
+ int err;
+
+ if (attr->link_create.flags)
+ return -EINVAL;
+
+ cgrp = cgroup_get_from_fd(attr->link_create.target_fd);
+ if (IS_ERR(cgrp))
+ return PTR_ERR(cgrp);
+
+ link = kzalloc(sizeof(*link), GFP_USER);
+ if (!link) {
+ err = -ENOMEM;
+ goto out_put_cgroup;
+ }
+ bpf_link_init(&link->link, BPF_LINK_TYPE_CGROUP, &bpf_cgroup_link_lops,
+ prog);
+ link->cgroup = cgrp;
+ link->type = attr->link_create.attach_type;
+
+ err = bpf_link_prime(&link->link, &link_primer);
+ if (err) {
+ kfree(link);
+ goto out_put_cgroup;
+ }
+
+ err = cgroup_bpf_attach(cgrp, NULL, NULL, link, link->type,
+ BPF_F_ALLOW_MULTI);
+ if (err) {
+ bpf_link_cleanup(&link_primer);
+ goto out_put_cgroup;
+ }
+
+ return bpf_link_settle(&link_primer);
+
+out_put_cgroup:
+ cgroup_put(cgrp);
+ return err;
}
int cgroup_bpf_prog_query(const union bpf_attr *attr,
@@ -514,8 +1025,16 @@
* The program type passed in via @type must be suitable for network
* filtering. No further check is performed to assert that.
*
- * This function will return %-EPERM if any if an attached program was found
- * and if it returned != 1 during execution. In all other cases, 0 is returned.
+ * For egress packets, this function can return:
+ * NET_XMIT_SUCCESS (0) - continue with packet output
+ * NET_XMIT_DROP (1) - drop packet and notify TCP to call cwr
+ * NET_XMIT_CN (2) - continue with packet output and notify TCP
+ * to call cwr
+ * -EPERM - drop packet
+ *
+ * For ingress packets, this function will return -EPERM if any
+ * attached program was found and if it returned != 1 during execution.
+ * Otherwise 0 is returned.
*/
int __cgroup_bpf_run_filter_skb(struct sock *sk,
struct sk_buff *skb,
@@ -523,6 +1042,7 @@
{
unsigned int offset = skb->data - skb_network_header(skb);
struct sock *save_sk;
+ void *saved_data_end;
struct cgroup *cgrp;
int ret;
@@ -536,11 +1056,23 @@
save_sk = skb->sk;
skb->sk = sk;
__skb_push(skb, offset);
- ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb,
- bpf_prog_run_save_cb);
+
+ /* compute pointers for the bpf prog */
+ bpf_compute_and_save_data_end(skb, &saved_data_end);
+
+ if (type == BPF_CGROUP_INET_EGRESS) {
+ ret = BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY(
+ cgrp->bpf.effective[type], skb, __bpf_prog_run_save_cb);
+ } else {
+ ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb,
+ __bpf_prog_run_save_cb);
+ ret = (ret == 1 ? 0 : -EPERM);
+ }
+ bpf_restore_data_end(skb, saved_data_end);
__skb_pull(skb, offset);
skb->sk = save_sk;
- return ret == 1 ? 0 : -EPERM;
+
+ return ret;
}
EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb);
@@ -661,28 +1193,28 @@
return !allow;
}
-EXPORT_SYMBOL(__cgroup_bpf_check_dev_permission);
static const struct bpf_func_proto *
-cgroup_dev_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+cgroup_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
- case BPF_FUNC_map_lookup_elem:
- return &bpf_map_lookup_elem_proto;
- case BPF_FUNC_map_update_elem:
- return &bpf_map_update_elem_proto;
- case BPF_FUNC_map_delete_elem:
- return &bpf_map_delete_elem_proto;
case BPF_FUNC_get_current_uid_gid:
return &bpf_get_current_uid_gid_proto;
case BPF_FUNC_get_local_storage:
return &bpf_get_local_storage_proto;
- case BPF_FUNC_trace_printk:
- if (capable(CAP_SYS_ADMIN))
- return bpf_get_trace_printk_proto();
+ case BPF_FUNC_get_current_cgroup_id:
+ return &bpf_get_current_cgroup_id_proto;
+ case BPF_FUNC_perf_event_output:
+ return &bpf_event_output_data_proto;
default:
- return NULL;
+ return bpf_base_func_proto(func_id);
}
+}
+
+static const struct bpf_func_proto *
+cgroup_dev_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+ return cgroup_base_func_proto(func_id, prog);
}
static bool cgroup_dev_is_valid_access(int off, int size,
@@ -722,3 +1254,715 @@
.get_func_proto = cgroup_dev_func_proto,
.is_valid_access = cgroup_dev_is_valid_access,
};
+
+/**
+ * __cgroup_bpf_run_filter_sysctl - Run a program on sysctl
+ *
+ * @head: sysctl table header
+ * @table: sysctl table
+ * @write: sysctl is being read (= 0) or written (= 1)
+ * @buf: pointer to buffer (in and out)
+ * @pcount: value-result argument: value is size of buffer pointed to by @buf,
+ * result is size of @new_buf if program set new value, initial value
+ * otherwise
+ * @ppos: value-result argument: value is position at which read from or write
+ * to sysctl is happening, result is new position if program overrode it,
+ * initial value otherwise
+ * @type: type of program to be executed
+ *
+ * Program is run when sysctl is being accessed, either read or written, and
+ * can allow or deny such access.
+ *
+ * This function will return %-EPERM if an attached program is found and
+ * returned value != 1 during execution. In all other cases 0 is returned.
+ */
+int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
+ struct ctl_table *table, int write,
+ char **buf, size_t *pcount, loff_t *ppos,
+ enum bpf_attach_type type)
+{
+ struct bpf_sysctl_kern ctx = {
+ .head = head,
+ .table = table,
+ .write = write,
+ .ppos = ppos,
+ .cur_val = NULL,
+ .cur_len = PAGE_SIZE,
+ .new_val = NULL,
+ .new_len = 0,
+ .new_updated = 0,
+ };
+ struct cgroup *cgrp;
+ loff_t pos = 0;
+ int ret;
+
+ ctx.cur_val = kmalloc_track_caller(ctx.cur_len, GFP_KERNEL);
+ if (!ctx.cur_val ||
+ table->proc_handler(table, 0, ctx.cur_val, &ctx.cur_len, &pos)) {
+ /* Let BPF program decide how to proceed. */
+ ctx.cur_len = 0;
+ }
+
+ if (write && *buf && *pcount) {
+ /* BPF program should be able to override new value with a
+ * buffer bigger than provided by user.
+ */
+ ctx.new_val = kmalloc_track_caller(PAGE_SIZE, GFP_KERNEL);
+ ctx.new_len = min_t(size_t, PAGE_SIZE, *pcount);
+ if (ctx.new_val) {
+ memcpy(ctx.new_val, *buf, ctx.new_len);
+ } else {
+ /* Let BPF program decide how to proceed. */
+ ctx.new_len = 0;
+ }
+ }
+
+ rcu_read_lock();
+ cgrp = task_dfl_cgroup(current);
+ ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN);
+ rcu_read_unlock();
+
+ kfree(ctx.cur_val);
+
+ if (ret == 1 && ctx.new_updated) {
+ kfree(*buf);
+ *buf = ctx.new_val;
+ *pcount = ctx.new_len;
+ } else {
+ kfree(ctx.new_val);
+ }
+
+ return ret == 1 ? 0 : -EPERM;
+}
+
+#ifdef CONFIG_NET
+static bool __cgroup_bpf_prog_array_is_empty(struct cgroup *cgrp,
+ enum bpf_attach_type attach_type)
+{
+ struct bpf_prog_array *prog_array;
+ bool empty;
+
+ rcu_read_lock();
+ prog_array = rcu_dereference(cgrp->bpf.effective[attach_type]);
+ empty = bpf_prog_array_is_empty(prog_array);
+ rcu_read_unlock();
+
+ return empty;
+}
+
+static int sockopt_alloc_buf(struct bpf_sockopt_kern *ctx, int max_optlen)
+{
+ if (unlikely(max_optlen < 0))
+ return -EINVAL;
+
+ if (unlikely(max_optlen > PAGE_SIZE)) {
+ /* We don't expose optvals that are greater than PAGE_SIZE
+ * to the BPF program.
+ */
+ max_optlen = PAGE_SIZE;
+ }
+
+ ctx->optval = kzalloc(max_optlen, GFP_USER);
+ if (!ctx->optval)
+ return -ENOMEM;
+
+ ctx->optval_end = ctx->optval + max_optlen;
+
+ return max_optlen;
+}
+
+static void sockopt_free_buf(struct bpf_sockopt_kern *ctx)
+{
+ kfree(ctx->optval);
+}
+
+int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
+ int *optname, char __user *optval,
+ int *optlen, char **kernel_optval)
+{
+ struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+ struct bpf_sockopt_kern ctx = {
+ .sk = sk,
+ .level = *level,
+ .optname = *optname,
+ };
+ int ret, max_optlen;
+
+ /* Opportunistic check to see whether we have any BPF program
+ * attached to the hook so we don't waste time allocating
+ * memory and locking the socket.
+ */
+ if (!cgroup_bpf_enabled ||
+ __cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_SETSOCKOPT))
+ return 0;
+
+ /* Allocate a bit more than the initial user buffer for
+ * BPF program. The canonical use case is overriding
+ * TCP_CONGESTION(nv) to TCP_CONGESTION(cubic).
+ */
+ max_optlen = max_t(int, 16, *optlen);
+
+ max_optlen = sockopt_alloc_buf(&ctx, max_optlen);
+ if (max_optlen < 0)
+ return max_optlen;
+
+ ctx.optlen = *optlen;
+
+ if (copy_from_user(ctx.optval, optval, min(*optlen, max_optlen)) != 0) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ lock_sock(sk);
+ ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_SETSOCKOPT],
+ &ctx, BPF_PROG_RUN);
+ release_sock(sk);
+
+ if (!ret) {
+ ret = -EPERM;
+ goto out;
+ }
+
+ if (ctx.optlen == -1) {
+ /* optlen set to -1, bypass kernel */
+ ret = 1;
+ } else if (ctx.optlen > max_optlen || ctx.optlen < -1) {
+ /* optlen is out of bounds */
+ ret = -EFAULT;
+ } else {
+ /* optlen within bounds, run kernel handler */
+ ret = 0;
+
+ /* export any potential modifications */
+ *level = ctx.level;
+ *optname = ctx.optname;
+
+ /* optlen == 0 from BPF indicates that we should
+ * use original userspace data.
+ */
+ if (ctx.optlen != 0) {
+ *optlen = ctx.optlen;
+ *kernel_optval = ctx.optval;
+ /* export and don't free sockopt buf */
+ return 0;
+ }
+ }
+
+out:
+ sockopt_free_buf(&ctx);
+ return ret;
+}
+
+int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
+ int optname, char __user *optval,
+ int __user *optlen, int max_optlen,
+ int retval)
+{
+ struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+ struct bpf_sockopt_kern ctx = {
+ .sk = sk,
+ .level = level,
+ .optname = optname,
+ .retval = retval,
+ };
+ int ret;
+
+ /* Opportunistic check to see whether we have any BPF program
+ * attached to the hook so we don't waste time allocating
+ * memory and locking the socket.
+ */
+ if (!cgroup_bpf_enabled ||
+ __cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_GETSOCKOPT))
+ return retval;
+
+ ctx.optlen = max_optlen;
+
+ max_optlen = sockopt_alloc_buf(&ctx, max_optlen);
+ if (max_optlen < 0)
+ return max_optlen;
+
+ if (!retval) {
+ /* If kernel getsockopt finished successfully,
+ * copy whatever was returned to the user back
+ * into our temporary buffer. Set optlen to the
+ * one that kernel returned as well to let
+ * BPF programs inspect the value.
+ */
+
+ if (get_user(ctx.optlen, optlen)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ if (ctx.optlen < 0) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ if (copy_from_user(ctx.optval, optval,
+ min(ctx.optlen, max_optlen)) != 0) {
+ ret = -EFAULT;
+ goto out;
+ }
+ }
+
+ lock_sock(sk);
+ ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT],
+ &ctx, BPF_PROG_RUN);
+ release_sock(sk);
+
+ if (!ret) {
+ ret = -EPERM;
+ goto out;
+ }
+
+ if (optval && (ctx.optlen > max_optlen || ctx.optlen < 0)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ /* BPF programs only allowed to set retval to 0, not some
+ * arbitrary value.
+ */
+ if (ctx.retval != 0 && ctx.retval != retval) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ if (ctx.optlen != 0) {
+ if (optval && copy_to_user(optval, ctx.optval, ctx.optlen)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ if (put_user(ctx.optlen, optlen)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ }
+
+ ret = ctx.retval;
+
+out:
+ sockopt_free_buf(&ctx);
+ return ret;
+}
+#endif
+
+static ssize_t sysctl_cpy_dir(const struct ctl_dir *dir, char **bufp,
+ size_t *lenp)
+{
+ ssize_t tmp_ret = 0, ret;
+
+ if (dir->header.parent) {
+ tmp_ret = sysctl_cpy_dir(dir->header.parent, bufp, lenp);
+ if (tmp_ret < 0)
+ return tmp_ret;
+ }
+
+ ret = strscpy(*bufp, dir->header.ctl_table[0].procname, *lenp);
+ if (ret < 0)
+ return ret;
+ *bufp += ret;
+ *lenp -= ret;
+ ret += tmp_ret;
+
+ /* Avoid leading slash. */
+ if (!ret)
+ return ret;
+
+ tmp_ret = strscpy(*bufp, "/", *lenp);
+ if (tmp_ret < 0)
+ return tmp_ret;
+ *bufp += tmp_ret;
+ *lenp -= tmp_ret;
+
+ return ret + tmp_ret;
+}
+
+BPF_CALL_4(bpf_sysctl_get_name, struct bpf_sysctl_kern *, ctx, char *, buf,
+ size_t, buf_len, u64, flags)
+{
+ ssize_t tmp_ret = 0, ret;
+
+ if (!buf)
+ return -EINVAL;
+
+ if (!(flags & BPF_F_SYSCTL_BASE_NAME)) {
+ if (!ctx->head)
+ return -EINVAL;
+ tmp_ret = sysctl_cpy_dir(ctx->head->parent, &buf, &buf_len);
+ if (tmp_ret < 0)
+ return tmp_ret;
+ }
+
+ ret = strscpy(buf, ctx->table->procname, buf_len);
+
+ return ret < 0 ? ret : tmp_ret + ret;
+}
+
+static const struct bpf_func_proto bpf_sysctl_get_name_proto = {
+ .func = bpf_sysctl_get_name,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+ .arg4_type = ARG_ANYTHING,
+};
+
+static int copy_sysctl_value(char *dst, size_t dst_len, char *src,
+ size_t src_len)
+{
+ if (!dst)
+ return -EINVAL;
+
+ if (!dst_len)
+ return -E2BIG;
+
+ if (!src || !src_len) {
+ memset(dst, 0, dst_len);
+ return -EINVAL;
+ }
+
+ memcpy(dst, src, min(dst_len, src_len));
+
+ if (dst_len > src_len) {
+ memset(dst + src_len, '\0', dst_len - src_len);
+ return src_len;
+ }
+
+ dst[dst_len - 1] = '\0';
+
+ return -E2BIG;
+}
+
+BPF_CALL_3(bpf_sysctl_get_current_value, struct bpf_sysctl_kern *, ctx,
+ char *, buf, size_t, buf_len)
+{
+ return copy_sysctl_value(buf, buf_len, ctx->cur_val, ctx->cur_len);
+}
+
+static const struct bpf_func_proto bpf_sysctl_get_current_value_proto = {
+ .func = bpf_sysctl_get_current_value,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_PTR_TO_UNINIT_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+};
+
+BPF_CALL_3(bpf_sysctl_get_new_value, struct bpf_sysctl_kern *, ctx, char *, buf,
+ size_t, buf_len)
+{
+ if (!ctx->write) {
+ if (buf && buf_len)
+ memset(buf, '\0', buf_len);
+ return -EINVAL;
+ }
+ return copy_sysctl_value(buf, buf_len, ctx->new_val, ctx->new_len);
+}
+
+static const struct bpf_func_proto bpf_sysctl_get_new_value_proto = {
+ .func = bpf_sysctl_get_new_value,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_PTR_TO_UNINIT_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+};
+
+BPF_CALL_3(bpf_sysctl_set_new_value, struct bpf_sysctl_kern *, ctx,
+ const char *, buf, size_t, buf_len)
+{
+ if (!ctx->write || !ctx->new_val || !ctx->new_len || !buf || !buf_len)
+ return -EINVAL;
+
+ if (buf_len > PAGE_SIZE - 1)
+ return -E2BIG;
+
+ memcpy(ctx->new_val, buf, buf_len);
+ ctx->new_len = buf_len;
+ ctx->new_updated = 1;
+
+ return 0;
+}
+
+static const struct bpf_func_proto bpf_sysctl_set_new_value_proto = {
+ .func = bpf_sysctl_set_new_value,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+};
+
+static const struct bpf_func_proto *
+sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+ switch (func_id) {
+ case BPF_FUNC_strtol:
+ return &bpf_strtol_proto;
+ case BPF_FUNC_strtoul:
+ return &bpf_strtoul_proto;
+ case BPF_FUNC_sysctl_get_name:
+ return &bpf_sysctl_get_name_proto;
+ case BPF_FUNC_sysctl_get_current_value:
+ return &bpf_sysctl_get_current_value_proto;
+ case BPF_FUNC_sysctl_get_new_value:
+ return &bpf_sysctl_get_new_value_proto;
+ case BPF_FUNC_sysctl_set_new_value:
+ return &bpf_sysctl_set_new_value_proto;
+ default:
+ return cgroup_base_func_proto(func_id, prog);
+ }
+}
+
+static bool sysctl_is_valid_access(int off, int size, enum bpf_access_type type,
+ const struct bpf_prog *prog,
+ struct bpf_insn_access_aux *info)
+{
+ const int size_default = sizeof(__u32);
+
+ if (off < 0 || off + size > sizeof(struct bpf_sysctl) || off % size)
+ return false;
+
+ switch (off) {
+ case bpf_ctx_range(struct bpf_sysctl, write):
+ if (type != BPF_READ)
+ return false;
+ bpf_ctx_record_field_size(info, size_default);
+ return bpf_ctx_narrow_access_ok(off, size, size_default);
+ case bpf_ctx_range(struct bpf_sysctl, file_pos):
+ if (type == BPF_READ) {
+ bpf_ctx_record_field_size(info, size_default);
+ return bpf_ctx_narrow_access_ok(off, size, size_default);
+ } else {
+ return size == size_default;
+ }
+ default:
+ return false;
+ }
+}
+
+static u32 sysctl_convert_ctx_access(enum bpf_access_type type,
+ const struct bpf_insn *si,
+ struct bpf_insn *insn_buf,
+ struct bpf_prog *prog, u32 *target_size)
+{
+ struct bpf_insn *insn = insn_buf;
+ u32 read_size;
+
+ switch (si->off) {
+ case offsetof(struct bpf_sysctl, write):
+ *insn++ = BPF_LDX_MEM(
+ BPF_SIZE(si->code), si->dst_reg, si->src_reg,
+ bpf_target_off(struct bpf_sysctl_kern, write,
+ sizeof_field(struct bpf_sysctl_kern,
+ write),
+ target_size));
+ break;
+ case offsetof(struct bpf_sysctl, file_pos):
+ /* ppos is a pointer so it should be accessed via indirect
+ * loads and stores. Also for stores additional temporary
+ * register is used since neither src_reg nor dst_reg can be
+ * overridden.
+ */
+ if (type == BPF_WRITE) {
+ int treg = BPF_REG_9;
+
+ if (si->src_reg == treg || si->dst_reg == treg)
+ --treg;
+ if (si->src_reg == treg || si->dst_reg == treg)
+ --treg;
+ *insn++ = BPF_STX_MEM(
+ BPF_DW, si->dst_reg, treg,
+ offsetof(struct bpf_sysctl_kern, tmp_reg));
+ *insn++ = BPF_LDX_MEM(
+ BPF_FIELD_SIZEOF(struct bpf_sysctl_kern, ppos),
+ treg, si->dst_reg,
+ offsetof(struct bpf_sysctl_kern, ppos));
+ *insn++ = BPF_STX_MEM(
+ BPF_SIZEOF(u32), treg, si->src_reg,
+ bpf_ctx_narrow_access_offset(
+ 0, sizeof(u32), sizeof(loff_t)));
+ *insn++ = BPF_LDX_MEM(
+ BPF_DW, treg, si->dst_reg,
+ offsetof(struct bpf_sysctl_kern, tmp_reg));
+ } else {
+ *insn++ = BPF_LDX_MEM(
+ BPF_FIELD_SIZEOF(struct bpf_sysctl_kern, ppos),
+ si->dst_reg, si->src_reg,
+ offsetof(struct bpf_sysctl_kern, ppos));
+ read_size = bpf_size_to_bytes(BPF_SIZE(si->code));
+ *insn++ = BPF_LDX_MEM(
+ BPF_SIZE(si->code), si->dst_reg, si->dst_reg,
+ bpf_ctx_narrow_access_offset(
+ 0, read_size, sizeof(loff_t)));
+ }
+ *target_size = sizeof(u32);
+ break;
+ }
+
+ return insn - insn_buf;
+}
+
+const struct bpf_verifier_ops cg_sysctl_verifier_ops = {
+ .get_func_proto = sysctl_func_proto,
+ .is_valid_access = sysctl_is_valid_access,
+ .convert_ctx_access = sysctl_convert_ctx_access,
+};
+
+const struct bpf_prog_ops cg_sysctl_prog_ops = {
+};
+
+static const struct bpf_func_proto *
+cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+ switch (func_id) {
+#ifdef CONFIG_NET
+ case BPF_FUNC_sk_storage_get:
+ return &bpf_sk_storage_get_proto;
+ case BPF_FUNC_sk_storage_delete:
+ return &bpf_sk_storage_delete_proto;
+#endif
+#ifdef CONFIG_INET
+ case BPF_FUNC_tcp_sock:
+ return &bpf_tcp_sock_proto;
+#endif
+ default:
+ return cgroup_base_func_proto(func_id, prog);
+ }
+}
+
+static bool cg_sockopt_is_valid_access(int off, int size,
+ enum bpf_access_type type,
+ const struct bpf_prog *prog,
+ struct bpf_insn_access_aux *info)
+{
+ const int size_default = sizeof(__u32);
+
+ if (off < 0 || off >= sizeof(struct bpf_sockopt))
+ return false;
+
+ if (off % size != 0)
+ return false;
+
+ if (type == BPF_WRITE) {
+ switch (off) {
+ case offsetof(struct bpf_sockopt, retval):
+ if (size != size_default)
+ return false;
+ return prog->expected_attach_type ==
+ BPF_CGROUP_GETSOCKOPT;
+ case offsetof(struct bpf_sockopt, optname):
+ fallthrough;
+ case offsetof(struct bpf_sockopt, level):
+ if (size != size_default)
+ return false;
+ return prog->expected_attach_type ==
+ BPF_CGROUP_SETSOCKOPT;
+ case offsetof(struct bpf_sockopt, optlen):
+ return size == size_default;
+ default:
+ return false;
+ }
+ }
+
+ switch (off) {
+ case offsetof(struct bpf_sockopt, sk):
+ if (size != sizeof(__u64))
+ return false;
+ info->reg_type = PTR_TO_SOCKET;
+ break;
+ case offsetof(struct bpf_sockopt, optval):
+ if (size != sizeof(__u64))
+ return false;
+ info->reg_type = PTR_TO_PACKET;
+ break;
+ case offsetof(struct bpf_sockopt, optval_end):
+ if (size != sizeof(__u64))
+ return false;
+ info->reg_type = PTR_TO_PACKET_END;
+ break;
+ case offsetof(struct bpf_sockopt, retval):
+ if (size != size_default)
+ return false;
+ return prog->expected_attach_type == BPF_CGROUP_GETSOCKOPT;
+ default:
+ if (size != size_default)
+ return false;
+ break;
+ }
+ return true;
+}
+
+#define CG_SOCKOPT_ACCESS_FIELD(T, F) \
+ T(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, F), \
+ si->dst_reg, si->src_reg, \
+ offsetof(struct bpf_sockopt_kern, F))
+
+static u32 cg_sockopt_convert_ctx_access(enum bpf_access_type type,
+ const struct bpf_insn *si,
+ struct bpf_insn *insn_buf,
+ struct bpf_prog *prog,
+ u32 *target_size)
+{
+ struct bpf_insn *insn = insn_buf;
+
+ switch (si->off) {
+ case offsetof(struct bpf_sockopt, sk):
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, sk);
+ break;
+ case offsetof(struct bpf_sockopt, level):
+ if (type == BPF_WRITE)
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, level);
+ else
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, level);
+ break;
+ case offsetof(struct bpf_sockopt, optname):
+ if (type == BPF_WRITE)
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, optname);
+ else
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optname);
+ break;
+ case offsetof(struct bpf_sockopt, optlen):
+ if (type == BPF_WRITE)
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, optlen);
+ else
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optlen);
+ break;
+ case offsetof(struct bpf_sockopt, retval):
+ if (type == BPF_WRITE)
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, retval);
+ else
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, retval);
+ break;
+ case offsetof(struct bpf_sockopt, optval):
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optval);
+ break;
+ case offsetof(struct bpf_sockopt, optval_end):
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optval_end);
+ break;
+ }
+
+ return insn - insn_buf;
+}
+
+static int cg_sockopt_get_prologue(struct bpf_insn *insn_buf,
+ bool direct_write,
+ const struct bpf_prog *prog)
+{
+ /* Nothing to do for sockopt argument. The data is kzalloc'ated.
+ */
+ return 0;
+}
+
+const struct bpf_verifier_ops cg_sockopt_verifier_ops = {
+ .get_func_proto = cg_sockopt_func_proto,
+ .is_valid_access = cg_sockopt_is_valid_access,
+ .convert_ctx_access = cg_sockopt_convert_ctx_access,
+ .gen_prologue = cg_sockopt_get_prologue,
+};
+
+const struct bpf_prog_ops cg_sockopt_prog_ops = {
+};
--
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