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-rw-r--r--kernel/bpf/cgroup.c1713
1 files changed, 1346 insertions, 367 deletions
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 9a500fadbef5..bf2fdb33fb31 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -14,20 +14,259 @@
#include <linux/string.h>
#include <linux/bpf.h>
#include <linux/bpf-cgroup.h>
+#include <linux/bpf_lsm.h>
+#include <linux/bpf_verifier.h>
#include <net/sock.h>
#include <net/bpf_sk_storage.h>
#include "../cgroup/cgroup-internal.h"
-DEFINE_STATIC_KEY_FALSE(cgroup_bpf_enabled_key);
+DEFINE_STATIC_KEY_ARRAY_FALSE(cgroup_bpf_enabled_key, MAX_CGROUP_BPF_ATTACH_TYPE);
EXPORT_SYMBOL(cgroup_bpf_enabled_key);
+/* __always_inline is necessary to prevent indirect call through run_prog
+ * function pointer.
+ */
+static __always_inline int
+bpf_prog_run_array_cg(const struct cgroup_bpf *cgrp,
+ enum cgroup_bpf_attach_type atype,
+ const void *ctx, bpf_prog_run_fn run_prog,
+ int retval, u32 *ret_flags)
+{
+ const struct bpf_prog_array_item *item;
+ const struct bpf_prog *prog;
+ const struct bpf_prog_array *array;
+ struct bpf_run_ctx *old_run_ctx;
+ struct bpf_cg_run_ctx run_ctx;
+ u32 func_ret;
+
+ run_ctx.retval = retval;
+ migrate_disable();
+ rcu_read_lock();
+ array = rcu_dereference(cgrp->effective[atype]);
+ item = &array->items[0];
+ old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
+ while ((prog = READ_ONCE(item->prog))) {
+ run_ctx.prog_item = item;
+ func_ret = run_prog(prog, ctx);
+ if (ret_flags) {
+ *(ret_flags) |= (func_ret >> 1);
+ func_ret &= 1;
+ }
+ if (!func_ret && !IS_ERR_VALUE((long)run_ctx.retval))
+ run_ctx.retval = -EPERM;
+ item++;
+ }
+ bpf_reset_run_ctx(old_run_ctx);
+ rcu_read_unlock();
+ migrate_enable();
+ return run_ctx.retval;
+}
+
+unsigned int __cgroup_bpf_run_lsm_sock(const void *ctx,
+ const struct bpf_insn *insn)
+{
+ const struct bpf_prog *shim_prog;
+ struct sock *sk;
+ struct cgroup *cgrp;
+ int ret = 0;
+ u64 *args;
+
+ args = (u64 *)ctx;
+ sk = (void *)(unsigned long)args[0];
+ /*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/
+ shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi));
+
+ cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+ if (likely(cgrp))
+ ret = bpf_prog_run_array_cg(&cgrp->bpf,
+ shim_prog->aux->cgroup_atype,
+ ctx, bpf_prog_run, 0, NULL);
+ return ret;
+}
+
+unsigned int __cgroup_bpf_run_lsm_socket(const void *ctx,
+ const struct bpf_insn *insn)
+{
+ const struct bpf_prog *shim_prog;
+ struct socket *sock;
+ struct cgroup *cgrp;
+ int ret = 0;
+ u64 *args;
+
+ args = (u64 *)ctx;
+ sock = (void *)(unsigned long)args[0];
+ /*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/
+ shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi));
+
+ cgrp = sock_cgroup_ptr(&sock->sk->sk_cgrp_data);
+ if (likely(cgrp))
+ ret = bpf_prog_run_array_cg(&cgrp->bpf,
+ shim_prog->aux->cgroup_atype,
+ ctx, bpf_prog_run, 0, NULL);
+ return ret;
+}
+
+unsigned int __cgroup_bpf_run_lsm_current(const void *ctx,
+ const struct bpf_insn *insn)
+{
+ const struct bpf_prog *shim_prog;
+ struct cgroup *cgrp;
+ int ret = 0;
+
+ /*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/
+ shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi));
+
+ /* We rely on trampoline's __bpf_prog_enter_lsm_cgroup to grab RCU read lock. */
+ cgrp = task_dfl_cgroup(current);
+ if (likely(cgrp))
+ ret = bpf_prog_run_array_cg(&cgrp->bpf,
+ shim_prog->aux->cgroup_atype,
+ ctx, bpf_prog_run, 0, NULL);
+ return ret;
+}
+
+#ifdef CONFIG_BPF_LSM
+struct cgroup_lsm_atype {
+ u32 attach_btf_id;
+ int refcnt;
+};
+
+static struct cgroup_lsm_atype cgroup_lsm_atype[CGROUP_LSM_NUM];
+
+static enum cgroup_bpf_attach_type
+bpf_cgroup_atype_find(enum bpf_attach_type attach_type, u32 attach_btf_id)
+{
+ int i;
+
+ lockdep_assert_held(&cgroup_mutex);
+
+ if (attach_type != BPF_LSM_CGROUP)
+ return to_cgroup_bpf_attach_type(attach_type);
+
+ for (i = 0; i < ARRAY_SIZE(cgroup_lsm_atype); i++)
+ if (cgroup_lsm_atype[i].attach_btf_id == attach_btf_id)
+ return CGROUP_LSM_START + i;
+
+ for (i = 0; i < ARRAY_SIZE(cgroup_lsm_atype); i++)
+ if (cgroup_lsm_atype[i].attach_btf_id == 0)
+ return CGROUP_LSM_START + i;
+
+ return -E2BIG;
+
+}
+
+void bpf_cgroup_atype_get(u32 attach_btf_id, int cgroup_atype)
+{
+ int i = cgroup_atype - CGROUP_LSM_START;
+
+ lockdep_assert_held(&cgroup_mutex);
+
+ WARN_ON_ONCE(cgroup_lsm_atype[i].attach_btf_id &&
+ cgroup_lsm_atype[i].attach_btf_id != attach_btf_id);
+
+ cgroup_lsm_atype[i].attach_btf_id = attach_btf_id;
+ cgroup_lsm_atype[i].refcnt++;
+}
+
+void bpf_cgroup_atype_put(int cgroup_atype)
+{
+ int i = cgroup_atype - CGROUP_LSM_START;
+
+ mutex_lock(&cgroup_mutex);
+ if (--cgroup_lsm_atype[i].refcnt <= 0)
+ cgroup_lsm_atype[i].attach_btf_id = 0;
+ WARN_ON_ONCE(cgroup_lsm_atype[i].refcnt < 0);
+ mutex_unlock(&cgroup_mutex);
+}
+#else
+static enum cgroup_bpf_attach_type
+bpf_cgroup_atype_find(enum bpf_attach_type attach_type, u32 attach_btf_id)
+{
+ if (attach_type != BPF_LSM_CGROUP)
+ return to_cgroup_bpf_attach_type(attach_type);
+ return -EOPNOTSUPP;
+}
+#endif /* CONFIG_BPF_LSM */
+
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
@@ -37,32 +276,45 @@ static void cgroup_bpf_release(struct work_struct *work)
{
struct cgroup *p, *cgrp = container_of(work, struct cgroup,
bpf.release_work);
- enum bpf_cgroup_storage_type stype;
struct bpf_prog_array *old_array;
- unsigned int type;
+ struct list_head *storages = &cgrp->bpf.storages;
+ struct bpf_cgroup_storage *storage, *stmp;
- mutex_lock(&cgroup_mutex);
+ unsigned int atype;
- for (type = 0; type < ARRAY_SIZE(cgrp->bpf.progs); type++) {
- struct list_head *progs = &cgrp->bpf.progs[type];
- struct bpf_prog_list *pl, *tmp;
+ mutex_lock(&cgroup_mutex);
- list_for_each_entry_safe(pl, tmp, progs, node) {
- list_del(&pl->node);
- bpf_prog_put(pl->prog);
- for_each_cgroup_storage_type(stype) {
- bpf_cgroup_storage_unlink(pl->storage[stype]);
- bpf_cgroup_storage_free(pl->storage[stype]);
+ for (atype = 0; atype < ARRAY_SIZE(cgrp->bpf.progs); atype++) {
+ struct hlist_head *progs = &cgrp->bpf.progs[atype];
+ struct bpf_prog_list *pl;
+ struct hlist_node *pltmp;
+
+ hlist_for_each_entry_safe(pl, pltmp, progs, node) {
+ hlist_del(&pl->node);
+ if (pl->prog) {
+ if (pl->prog->expected_attach_type == BPF_LSM_CGROUP)
+ bpf_trampoline_unlink_cgroup_shim(pl->prog);
+ bpf_prog_put(pl->prog);
+ }
+ if (pl->link) {
+ if (pl->link->link.prog->expected_attach_type == BPF_LSM_CGROUP)
+ bpf_trampoline_unlink_cgroup_shim(pl->link->link.prog);
+ bpf_cgroup_link_auto_detach(pl->link);
}
kfree(pl);
- static_branch_dec(&cgroup_bpf_enabled_key);
+ static_branch_dec(&cgroup_bpf_enabled_key[atype]);
}
old_array = rcu_dereference_protected(
- cgrp->bpf.effective[type],
+ cgrp->bpf.effective[atype],
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))
@@ -85,16 +337,28 @@ static void cgroup_bpf_release_fn(struct percpu_ref *ref)
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.
* it's slow but the list cannot be long
*/
-static u32 prog_list_length(struct list_head *head)
+static u32 prog_list_length(struct hlist_head *head)
{
struct bpf_prog_list *pl;
u32 cnt = 0;
- list_for_each_entry(pl, head, node) {
- if (!pl->prog)
+ hlist_for_each_entry(pl, head, node) {
+ if (!prog_list_prog(pl))
continue;
cnt++;
}
@@ -106,7 +370,7 @@ static u32 prog_list_length(struct list_head *head)
* if parent has overridable or multi-prog, allow attaching
*/
static bool hierarchy_allows_attach(struct cgroup *cgrp,
- enum bpf_attach_type type)
+ enum cgroup_bpf_attach_type atype)
{
struct cgroup *p;
@@ -114,12 +378,12 @@ static bool hierarchy_allows_attach(struct cgroup *cgrp,
if (!p)
return true;
do {
- u32 flags = p->bpf.flags[type];
+ u32 flags = p->bpf.flags[atype];
u32 cnt;
if (flags & BPF_F_ALLOW_MULTI)
return true;
- cnt = prog_list_length(&p->bpf.progs[type]);
+ cnt = prog_list_length(&p->bpf.progs[atype]);
WARN_ON_ONCE(cnt > 1);
if (cnt == 1)
return !!(flags & BPF_F_ALLOW_OVERRIDE);
@@ -135,10 +399,10 @@ static bool hierarchy_allows_attach(struct cgroup *cgrp,
* to programs in this cgroup
*/
static int compute_effective_progs(struct cgroup *cgrp,
- enum bpf_attach_type type,
+ enum cgroup_bpf_attach_type atype,
struct bpf_prog_array **array)
{
- enum bpf_cgroup_storage_type stype;
+ struct bpf_prog_array_item *item;
struct bpf_prog_array *progs;
struct bpf_prog_list *pl;
struct cgroup *p = cgrp;
@@ -146,8 +410,8 @@ static int compute_effective_progs(struct cgroup *cgrp,
/* count number of effective programs by walking parents */
do {
- if (cnt == 0 || (p->bpf.flags[type] & BPF_F_ALLOW_MULTI))
- cnt += prog_list_length(&p->bpf.progs[type]);
+ if (cnt == 0 || (p->bpf.flags[atype] & BPF_F_ALLOW_MULTI))
+ cnt += prog_list_length(&p->bpf.progs[atype]);
p = cgroup_parent(p);
} while (p);
@@ -159,17 +423,17 @@ static int compute_effective_progs(struct cgroup *cgrp,
cnt = 0;
p = cgrp;
do {
- if (cnt > 0 && !(p->bpf.flags[type] & BPF_F_ALLOW_MULTI))
+ if (cnt > 0 && !(p->bpf.flags[atype] & BPF_F_ALLOW_MULTI))
continue;
- list_for_each_entry(pl, &p->bpf.progs[type], node) {
- if (!pl->prog)
+ hlist_for_each_entry(pl, &p->bpf.progs[atype], node) {
+ if (!prog_list_prog(pl))
continue;
- progs->items[cnt].prog = pl->prog;
- for_each_cgroup_storage_type(stype)
- progs->items[cnt].cgroup_storage[stype] =
- pl->storage[stype];
+ 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)));
@@ -179,10 +443,10 @@ static int compute_effective_progs(struct cgroup *cgrp,
}
static void activate_effective_progs(struct cgroup *cgrp,
- enum bpf_attach_type type,
+ enum cgroup_bpf_attach_type atype,
struct bpf_prog_array *old_array)
{
- old_array = rcu_replace_pointer(cgrp->bpf.effective[type], old_array,
+ old_array = rcu_replace_pointer(cgrp->bpf.effective[atype], old_array,
lockdep_is_held(&cgroup_mutex));
/* free prog array after grace period, since __cgroup_bpf_run_*()
* might be still walking the array
@@ -213,7 +477,9 @@ int cgroup_bpf_inherit(struct cgroup *cgrp)
cgroup_bpf_get(p);
for (i = 0; i < NR; i++)
- INIT_LIST_HEAD(&cgrp->bpf.progs[i]);
+ INIT_HLIST_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]))
@@ -227,13 +493,16 @@ 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;
}
static int update_effective_progs(struct cgroup *cgrp,
- enum bpf_attach_type type)
+ enum cgroup_bpf_attach_type atype)
{
struct cgroup_subsys_state *css;
int err;
@@ -245,7 +514,7 @@ static int update_effective_progs(struct cgroup *cgrp,
if (percpu_ref_is_zero(&desc->bpf.refcnt))
continue;
- err = compute_effective_progs(desc, type, &desc->bpf.inactive);
+ err = compute_effective_progs(desc, atype, &desc->bpf.inactive);
if (err)
goto cleanup;
}
@@ -262,7 +531,7 @@ static int update_effective_progs(struct cgroup *cgrp,
continue;
}
- activate_effective_progs(desc, type, desc->bpf.inactive);
+ activate_effective_progs(desc, atype, desc->bpf.inactive);
desc->bpf.inactive = NULL;
}
@@ -284,39 +553,93 @@ cleanup:
#define BPF_CGROUP_MAX_PROGS 64
+static struct bpf_prog_list *find_attach_entry(struct hlist_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 (hlist_empty(progs))
+ return NULL;
+ return hlist_entry(progs->first, typeof(*pl), node);
+ }
+
+ hlist_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) {
+ hlist_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,
- struct bpf_prog *replace_prog,
- enum bpf_attach_type type, u32 flags)
+static 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[MAX_BPF_CGROUP_STORAGE_TYPE],
- *old_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {NULL};
- struct bpf_prog_list *pl, *replace_pl = NULL;
- enum bpf_cgroup_storage_type stype;
+ struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
+ struct bpf_cgroup_storage *new_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
+ struct bpf_prog *new_prog = prog ? : link->link.prog;
+ enum cgroup_bpf_attach_type atype;
+ struct bpf_prog_list *pl;
+ struct hlist_head *progs;
int err;
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))
+ atype = bpf_cgroup_atype_find(type, new_prog->aux->attach_btf_id);
+ if (atype < 0)
+ return -EINVAL;
+
+ progs = &cgrp->bpf.progs[atype];
+
+ if (!hierarchy_allows_attach(cgrp, atype))
return -EPERM;
- if (!list_empty(progs) && cgrp->bpf.flags[type] != saved_flags)
+ if (!hlist_empty(progs) && cgrp->bpf.flags[atype] != saved_flags)
/* Disallow attaching non-overridable on top
* of existing overridable in this cgroup.
* Disallow attaching multi-prog if overridable or none
@@ -326,215 +649,483 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
if (prog_list_length(progs) >= BPF_CGROUP_MAX_PROGS)
return -E2BIG;
- if (flags & BPF_F_ALLOW_MULTI) {
- list_for_each_entry(pl, progs, node) {
- if (pl->prog == prog)
- /* disallow attaching the same prog twice */
- return -EINVAL;
- if (pl->prog == replace_prog)
- replace_pl = pl;
- }
- if ((flags & BPF_F_REPLACE) && !replace_pl)
- /* prog to replace not found for cgroup */
- return -ENOENT;
- } else if (!list_empty(progs)) {
- replace_pl = list_first_entry(progs, typeof(*pl), node);
- }
+ pl = find_attach_entry(progs, prog, link, replace_prog,
+ flags & BPF_F_ALLOW_MULTI);
+ if (IS_ERR(pl))
+ return PTR_ERR(pl);
- for_each_cgroup_storage_type(stype) {
- storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
- if (IS_ERR(storage[stype])) {
- storage[stype] = NULL;
- for_each_cgroup_storage_type(stype)
- bpf_cgroup_storage_free(storage[stype]);
- return -ENOMEM;
- }
- }
+ if (bpf_cgroup_storages_alloc(storage, new_storage, type,
+ prog ? : link->link.prog, cgrp))
+ return -ENOMEM;
- if (replace_pl) {
- pl = replace_pl;
+ if (pl) {
old_prog = pl->prog;
- for_each_cgroup_storage_type(stype) {
- old_storage[stype] = pl->storage[stype];
- bpf_cgroup_storage_unlink(old_storage[stype]);
- }
} else {
+ struct hlist_node *last = NULL;
+
pl = kmalloc(sizeof(*pl), GFP_KERNEL);
if (!pl) {
- for_each_cgroup_storage_type(stype)
- bpf_cgroup_storage_free(storage[stype]);
+ bpf_cgroup_storages_free(new_storage);
return -ENOMEM;
}
- list_add_tail(&pl->node, progs);
+ if (hlist_empty(progs))
+ hlist_add_head(&pl->node, progs);
+ else
+ hlist_for_each(last, progs) {
+ if (last->next)
+ continue;
+ hlist_add_behind(&pl->node, last);
+ break;
+ }
}
pl->prog = prog;
- for_each_cgroup_storage_type(stype)
- pl->storage[stype] = storage[stype];
+ pl->link = link;
+ bpf_cgroup_storages_assign(pl->storage, storage);
+ cgrp->bpf.flags[atype] = saved_flags;
- cgrp->bpf.flags[type] = saved_flags;
+ if (type == BPF_LSM_CGROUP) {
+ err = bpf_trampoline_link_cgroup_shim(new_prog, atype);
+ if (err)
+ goto cleanup;
+ }
- err = update_effective_progs(cgrp, type);
+ err = update_effective_progs(cgrp, atype);
if (err)
- goto cleanup;
+ goto cleanup_trampoline;
- static_branch_inc(&cgroup_bpf_enabled_key);
- for_each_cgroup_storage_type(stype) {
- if (!old_storage[stype])
- continue;
- bpf_cgroup_storage_free(old_storage[stype]);
- }
if (old_prog) {
+ if (type == BPF_LSM_CGROUP)
+ bpf_trampoline_unlink_cgroup_shim(old_prog);
bpf_prog_put(old_prog);
- static_branch_dec(&cgroup_bpf_enabled_key);
+ } else {
+ static_branch_inc(&cgroup_bpf_enabled_key[atype]);
}
- for_each_cgroup_storage_type(stype)
- bpf_cgroup_storage_link(storage[stype], cgrp, type);
+ bpf_cgroup_storages_link(new_storage, cgrp, type);
return 0;
+cleanup_trampoline:
+ if (type == BPF_LSM_CGROUP)
+ bpf_trampoline_unlink_cgroup_shim(new_prog);
+
cleanup:
- /* and cleanup the prog list */
- pl->prog = old_prog;
- for_each_cgroup_storage_type(stype) {
- bpf_cgroup_storage_free(pl->storage[stype]);
- pl->storage[stype] = old_storage[stype];
- bpf_cgroup_storage_link(old_storage[stype], cgrp, type);
+ if (old_prog) {
+ pl->prog = old_prog;
+ pl->link = NULL;
}
- if (!replace_pl) {
- list_del(&pl->node);
+ bpf_cgroup_storages_free(new_storage);
+ if (!old_prog) {
+ hlist_del(&pl->node);
kfree(pl);
}
return err;
}
+static 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)
+{
+ int ret;
+
+ mutex_lock(&cgroup_mutex);
+ ret = __cgroup_bpf_attach(cgrp, prog, replace_prog, link, type, flags);
+ mutex_unlock(&cgroup_mutex);
+ return ret;
+}
+
+/* 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 cgroup_bpf_attach_type atype,
+ 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 hlist_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[atype] & BPF_F_ALLOW_MULTI))
+ continue;
+
+ head = &cg->bpf.progs[atype];
+ hlist_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[atype],
+ 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.
*/
-int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
- enum bpf_attach_type type)
+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[type];
- enum bpf_cgroup_storage_type stype;
- u32 flags = cgrp->bpf.flags[type];
- struct bpf_prog *old_prog = NULL;
+ enum cgroup_bpf_attach_type atype;
+ struct bpf_prog *old_prog;
struct bpf_prog_list *pl;
- int err;
+ struct hlist_head *progs;
+ bool found = false;
- 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;
- }
+ atype = bpf_cgroup_atype_find(link->type, new_prog->aux->attach_btf_id);
+ if (atype < 0)
+ return -EINVAL;
- 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;
+ progs = &cgrp->bpf.progs[atype];
+
+ if (link->link.prog->type != new_prog->type)
+ return -EINVAL;
+
+ hlist_for_each_entry(pl, progs, node) {
+ if (pl->link == link) {
+ found = true;
break;
}
- if (!old_prog)
- return -ENOENT;
- } else {
+ }
+ if (!found)
+ return -ENOENT;
+
+ old_prog = xchg(&link->link.prog, new_prog);
+ replace_effective_prog(cgrp, atype, 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 hlist_head *progs,
+ struct bpf_prog *prog,
+ struct bpf_cgroup_link *link,
+ bool allow_multi)
+{
+ struct bpf_prog_list *pl;
+
+ if (!allow_multi) {
+ if (hlist_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)
+ * allow detaching with invalid FD (prog==NULL) in legacy mode
*/
- pl = list_first_entry(progs, typeof(*pl), node);
- old_prog = pl->prog;
- pl->prog = NULL;
+ return hlist_entry(progs->first, typeof(*pl), node);
}
- err = update_effective_progs(cgrp, type);
- if (err)
- goto cleanup;
+ 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);
- /* now can actually delete it from this cgroup list */
- list_del(&pl->node);
- for_each_cgroup_storage_type(stype) {
- bpf_cgroup_storage_unlink(pl->storage[stype]);
- bpf_cgroup_storage_free(pl->storage[stype]);
+ /* find the prog or link and detach it */
+ hlist_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
+ * @atype: Type of detach operation
+ */
+static void purge_effective_progs(struct cgroup *cgrp, struct bpf_prog *prog,
+ struct bpf_cgroup_link *link,
+ enum cgroup_bpf_attach_type atype)
+{
+ struct cgroup_subsys_state *css;
+ struct bpf_prog_array *progs;
+ struct bpf_prog_list *pl;
+ struct hlist_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[atype] & BPF_F_ALLOW_MULTI))
+ continue;
+
+ head = &cg->bpf.progs[atype];
+ hlist_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[atype],
+ 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
+ * @link: 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.
+ */
+static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
+ struct bpf_cgroup_link *link, enum bpf_attach_type type)
+{
+ enum cgroup_bpf_attach_type atype;
+ struct bpf_prog *old_prog;
+ struct bpf_prog_list *pl;
+ struct hlist_head *progs;
+ u32 attach_btf_id = 0;
+ u32 flags;
+
+ if (prog)
+ attach_btf_id = prog->aux->attach_btf_id;
+ if (link)
+ attach_btf_id = link->link.prog->aux->attach_btf_id;
+
+ atype = bpf_cgroup_atype_find(type, attach_btf_id);
+ if (atype < 0)
+ return -EINVAL;
+
+ progs = &cgrp->bpf.progs[atype];
+ flags = cgrp->bpf.flags[atype];
+
+ 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, atype)) {
+ /* 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, atype);
+ }
+
+ /* now can actually delete it from this cgroup list */
+ hlist_del(&pl->node);
+
kfree(pl);
- if (list_empty(progs))
+ if (hlist_empty(progs))
/* last program was detached, reset flags to zero */
- cgrp->bpf.flags[type] = 0;
-
- bpf_prog_put(old_prog);
- static_branch_dec(&cgroup_bpf_enabled_key);
+ cgrp->bpf.flags[atype] = 0;
+ if (old_prog) {
+ if (type == BPF_LSM_CGROUP)
+ bpf_trampoline_unlink_cgroup_shim(old_prog);
+ bpf_prog_put(old_prog);
+ }
+ static_branch_dec(&cgroup_bpf_enabled_key[atype]);
return 0;
+}
-cleanup:
- /* and restore back old_prog */
- pl->prog = old_prog;
- return err;
+static int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
+ enum bpf_attach_type type)
+{
+ int ret;
+
+ mutex_lock(&cgroup_mutex);
+ ret = __cgroup_bpf_detach(cgrp, prog, NULL, type);
+ mutex_unlock(&cgroup_mutex);
+ return ret;
}
/* Must be called with cgroup_mutex held to avoid races. */
-int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
- union bpf_attr __user *uattr)
+static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
+ union bpf_attr __user *uattr)
{
+ __u32 __user *prog_attach_flags = u64_to_user_ptr(attr->query.prog_attach_flags);
+ bool effective_query = attr->query.query_flags & BPF_F_QUERY_EFFECTIVE;
__u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
enum bpf_attach_type type = attr->query.attach_type;
- struct list_head *progs = &cgrp->bpf.progs[type];
- u32 flags = cgrp->bpf.flags[type];
+ enum cgroup_bpf_attach_type from_atype, to_atype;
+ enum cgroup_bpf_attach_type atype;
struct bpf_prog_array *effective;
int cnt, ret = 0, i;
+ int total_cnt = 0;
+ u32 flags;
- effective = rcu_dereference_protected(cgrp->bpf.effective[type],
- lockdep_is_held(&cgroup_mutex));
+ if (effective_query && prog_attach_flags)
+ return -EINVAL;
- if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE)
- cnt = bpf_prog_array_length(effective);
- else
- cnt = prog_list_length(progs);
+ if (type == BPF_LSM_CGROUP) {
+ if (!effective_query && attr->query.prog_cnt &&
+ prog_ids && !prog_attach_flags)
+ return -EINVAL;
+
+ from_atype = CGROUP_LSM_START;
+ to_atype = CGROUP_LSM_END;
+ flags = 0;
+ } else {
+ from_atype = to_cgroup_bpf_attach_type(type);
+ if (from_atype < 0)
+ return -EINVAL;
+ to_atype = from_atype;
+ flags = cgrp->bpf.flags[from_atype];
+ }
+ for (atype = from_atype; atype <= to_atype; atype++) {
+ if (effective_query) {
+ effective = rcu_dereference_protected(cgrp->bpf.effective[atype],
+ lockdep_is_held(&cgroup_mutex));
+ total_cnt += bpf_prog_array_length(effective);
+ } else {
+ total_cnt += prog_list_length(&cgrp->bpf.progs[atype]);
+ }
+ }
+
+ /* always output uattr->query.attach_flags as 0 during effective query */
+ flags = effective_query ? 0 : flags;
if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
return -EFAULT;
- if (copy_to_user(&uattr->query.prog_cnt, &cnt, sizeof(cnt)))
+ if (copy_to_user(&uattr->query.prog_cnt, &total_cnt, sizeof(total_cnt)))
return -EFAULT;
- if (attr->query.prog_cnt == 0 || !prog_ids || !cnt)
+ if (attr->query.prog_cnt == 0 || !prog_ids || !total_cnt)
/* return early if user requested only program count + flags */
return 0;
- if (attr->query.prog_cnt < cnt) {
- cnt = attr->query.prog_cnt;
+
+ if (attr->query.prog_cnt < total_cnt) {
+ total_cnt = attr->query.prog_cnt;
ret = -ENOSPC;
}
- if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) {
- 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;
- if (copy_to_user(prog_ids + i, &id, sizeof(id)))
- return -EFAULT;
- if (++i == cnt)
- break;
+ for (atype = from_atype; atype <= to_atype && total_cnt; atype++) {
+ if (effective_query) {
+ effective = rcu_dereference_protected(cgrp->bpf.effective[atype],
+ lockdep_is_held(&cgroup_mutex));
+ cnt = min_t(int, bpf_prog_array_length(effective), total_cnt);
+ ret = bpf_prog_array_copy_to_user(effective, prog_ids, cnt);
+ } else {
+ struct hlist_head *progs;
+ struct bpf_prog_list *pl;
+ struct bpf_prog *prog;
+ u32 id;
+
+ progs = &cgrp->bpf.progs[atype];
+ cnt = min_t(int, prog_list_length(progs), total_cnt);
+ i = 0;
+ hlist_for_each_entry(pl, progs, node) {
+ prog = prog_list_prog(pl);
+ id = prog->aux->id;
+ if (copy_to_user(prog_ids + i, &id, sizeof(id)))
+ return -EFAULT;
+ if (++i == cnt)
+ break;
+ }
+
+ if (prog_attach_flags) {
+ flags = cgrp->bpf.flags[atype];
+
+ for (i = 0; i < cnt; i++)
+ if (copy_to_user(prog_attach_flags + i,
+ &flags, sizeof(flags)))
+ return -EFAULT;
+ prog_attach_flags += cnt;
+ }
}
+
+ prog_ids += cnt;
+ total_cnt -= cnt;
}
return ret;
}
+static int cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
+ union bpf_attr __user *uattr)
+{
+ int ret;
+
+ mutex_lock(&cgroup_mutex);
+ ret = __cgroup_bpf_query(cgrp, attr, uattr);
+ mutex_unlock(&cgroup_mutex);
+ return ret;
+}
+
int cgroup_bpf_prog_attach(const union bpf_attr *attr,
enum bpf_prog_type ptype, struct bpf_prog *prog)
{
@@ -555,8 +1146,8 @@ int cgroup_bpf_prog_attach(const union bpf_attr *attr,
}
}
- ret = cgroup_bpf_attach(cgrp, prog, replace_prog, attr->attach_type,
- attr->attach_flags);
+ ret = cgroup_bpf_attach(cgrp, prog, replace_prog, NULL,
+ attr->attach_type, attr->attach_flags);
if (replace_prog)
bpf_prog_put(replace_prog);
@@ -578,7 +1169,7 @@ int cgroup_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
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);
@@ -586,6 +1177,143 @@ int cgroup_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
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));
+ if (cg_link->type == BPF_LSM_CGROUP)
+ bpf_trampoline_unlink_cgroup_shim(cg_link->link.prog);
+
+ 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,
union bpf_attr __user *uattr)
{
@@ -606,7 +1334,7 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr,
* __cgroup_bpf_run_filter_skb() - Run a program for packet filtering
* @sk: The socket sending or receiving traffic
* @skb: The skb that is being sent or received
- * @type: The type of program to be exectuted
+ * @type: The type of program to be executed
*
* If no socket is passed, or the socket is not of type INET or INET6,
* this function does nothing and returns 0.
@@ -619,7 +1347,7 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr,
* 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
+ * -err - drop packet
*
* For ingress packets, this function will return -EPERM if any
* attached program was found and if it returned != 1 during execution.
@@ -627,7 +1355,7 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr,
*/
int __cgroup_bpf_run_filter_skb(struct sock *sk,
struct sk_buff *skb,
- enum bpf_attach_type type)
+ enum cgroup_bpf_attach_type atype)
{
unsigned int offset = skb->data - skb_network_header(skb);
struct sock *save_sk;
@@ -649,13 +1377,41 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk,
/* 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);
+ if (atype == CGROUP_INET_EGRESS) {
+ u32 flags = 0;
+ bool cn;
+
+ ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, skb,
+ __bpf_prog_run_save_cb, 0, &flags);
+
+ /* Return values of CGROUP EGRESS BPF programs are:
+ * 0: drop packet
+ * 1: keep packet
+ * 2: drop packet and cn
+ * 3: keep packet and cn
+ *
+ * The returned value is then converted to one of the NET_XMIT
+ * or an error code that is then interpreted as drop packet
+ * (and no cn):
+ * 0: NET_XMIT_SUCCESS skb should be transmitted
+ * 1: NET_XMIT_DROP skb should be dropped and cn
+ * 2: NET_XMIT_CN skb should be transmitted and cn
+ * 3: -err skb should be dropped
+ */
+
+ cn = flags & BPF_RET_SET_CN;
+ if (ret && !IS_ERR_VALUE((long)ret))
+ ret = -EFAULT;
+ if (!ret)
+ ret = (cn ? NET_XMIT_CN : NET_XMIT_SUCCESS);
+ else
+ ret = (cn ? NET_XMIT_DROP : ret);
} else {
- ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb,
- __bpf_prog_run_save_cb);
- ret = (ret == 1 ? 0 : -EPERM);
+ ret = bpf_prog_run_array_cg(&cgrp->bpf, atype,
+ skb, __bpf_prog_run_save_cb, 0,
+ NULL);
+ if (ret && !IS_ERR_VALUE((long)ret))
+ ret = -EFAULT;
}
bpf_restore_data_end(skb, saved_data_end);
__skb_pull(skb, offset);
@@ -668,7 +1424,7 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb);
/**
* __cgroup_bpf_run_filter_sk() - Run a program on a sock
* @sk: sock structure to manipulate
- * @type: The type of program to be exectuted
+ * @type: The type of program to be executed
*
* socket is passed is expected to be of type INET or INET6.
*
@@ -679,13 +1435,12 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb);
* and if it returned != 1 during execution. In all other cases, 0 is returned.
*/
int __cgroup_bpf_run_filter_sk(struct sock *sk,
- enum bpf_attach_type type)
+ enum cgroup_bpf_attach_type atype)
{
struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
- int ret;
- ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sk, BPF_PROG_RUN);
- return ret == 1 ? 0 : -EPERM;
+ return bpf_prog_run_array_cg(&cgrp->bpf, atype, sk, bpf_prog_run, 0,
+ NULL);
}
EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk);
@@ -694,8 +1449,10 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk);
* provided by user sockaddr
* @sk: sock struct that will use sockaddr
* @uaddr: sockaddr struct provided by user
- * @type: The type of program to be exectuted
+ * @type: The type of program to be executed
* @t_ctx: Pointer to attach type specific context
+ * @flags: Pointer to u32 which contains higher bits of BPF program
+ * return value (OR'ed together).
*
* socket is expected to be of type INET or INET6.
*
@@ -704,8 +1461,9 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk);
*/
int __cgroup_bpf_run_filter_sock_addr(struct sock *sk,
struct sockaddr *uaddr,
- enum bpf_attach_type type,
- void *t_ctx)
+ enum cgroup_bpf_attach_type atype,
+ void *t_ctx,
+ u32 *flags)
{
struct bpf_sock_addr_kern ctx = {
.sk = sk,
@@ -714,7 +1472,6 @@ int __cgroup_bpf_run_filter_sock_addr(struct sock *sk,
};
struct sockaddr_storage unspec;
struct cgroup *cgrp;
- int ret;
/* Check socket family since not all sockets represent network
* endpoint (e.g. AF_UNIX).
@@ -728,9 +1485,8 @@ int __cgroup_bpf_run_filter_sock_addr(struct sock *sk,
}
cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
- ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN);
-
- return ret == 1 ? 0 : -EPERM;
+ return bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run,
+ 0, flags);
}
EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_addr);
@@ -740,7 +1496,7 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_addr);
* @sock_ops: bpf_sock_ops_kern struct to pass to program. Contains
* sk with connection information (IP addresses, etc.) May not contain
* cgroup info if it is a req sock.
- * @type: The type of program to be exectuted
+ * @type: The type of program to be executed
*
* socket passed is expected to be of type INET or INET6.
*
@@ -752,19 +1508,17 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_addr);
*/
int __cgroup_bpf_run_filter_sock_ops(struct sock *sk,
struct bpf_sock_ops_kern *sock_ops,
- enum bpf_attach_type type)
+ enum cgroup_bpf_attach_type atype)
{
struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
- int ret;
- ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sock_ops,
- BPF_PROG_RUN);
- return ret == 1 ? 0 : -EPERM;
+ return bpf_prog_run_array_cg(&cgrp->bpf, atype, sock_ops, bpf_prog_run,
+ 0, NULL);
}
EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_ops);
int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
- short access, enum bpf_attach_type type)
+ short access, enum cgroup_bpf_attach_type atype)
{
struct cgroup *cgrp;
struct bpf_cgroup_dev_ctx ctx = {
@@ -772,53 +1526,97 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
.major = major,
.minor = minor,
};
- int allow = 1;
+ int ret;
rcu_read_lock();
cgrp = task_dfl_cgroup(current);
- allow = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx,
- BPF_PROG_RUN);
+ ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run, 0,
+ NULL);
rcu_read_unlock();
- return !allow;
+ return ret;
}
-EXPORT_SYMBOL(__cgroup_bpf_check_dev_permission);
-static const struct bpf_func_proto *
-cgroup_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags)
{
- 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_map_push_elem:
- return &bpf_map_push_elem_proto;
- case BPF_FUNC_map_pop_elem:
- return &bpf_map_pop_elem_proto;
- case BPF_FUNC_map_peek_elem:
- return &bpf_map_peek_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_get_current_cgroup_id:
- return &bpf_get_current_cgroup_id_proto;
- case BPF_FUNC_trace_printk:
- if (capable(CAP_SYS_ADMIN))
- return bpf_get_trace_printk_proto();
- /* fall through */
- default:
- return NULL;
- }
+ /* flags argument is not used now,
+ * but provides an ability to extend the API.
+ * verifier checks that its value is correct.
+ */
+ enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
+ struct bpf_cgroup_storage *storage;
+ struct bpf_cg_run_ctx *ctx;
+ void *ptr;
+
+ /* get current cgroup storage from BPF run context */
+ ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
+ storage = ctx->prog_item->cgroup_storage[stype];
+
+ if (stype == BPF_CGROUP_STORAGE_SHARED)
+ ptr = &READ_ONCE(storage->buf)->data[0];
+ else
+ ptr = this_cpu_ptr(storage->percpu_buf);
+
+ return (unsigned long)ptr;
}
+const struct bpf_func_proto bpf_get_local_storage_proto = {
+ .func = bpf_get_local_storage,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_MAP_VALUE,
+ .arg1_type = ARG_CONST_MAP_PTR,
+ .arg2_type = ARG_ANYTHING,
+};
+
+BPF_CALL_0(bpf_get_retval)
+{
+ struct bpf_cg_run_ctx *ctx =
+ container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
+
+ return ctx->retval;
+}
+
+const struct bpf_func_proto bpf_get_retval_proto = {
+ .func = bpf_get_retval,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+};
+
+BPF_CALL_1(bpf_set_retval, int, retval)
+{
+ struct bpf_cg_run_ctx *ctx =
+ container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
+
+ ctx->retval = retval;
+ return 0;
+}
+
+const struct bpf_func_proto bpf_set_retval_proto = {
+ .func = bpf_set_retval,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_ANYTHING,
+};
+
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);
+ const struct bpf_func_proto *func_proto;
+
+ func_proto = cgroup_common_func_proto(func_id, prog);
+ if (func_proto)
+ return func_proto;
+
+ func_proto = cgroup_current_func_proto(func_id, prog);
+ if (func_proto)
+ return func_proto;
+
+ switch (func_id) {
+ case BPF_FUNC_perf_event_output:
+ return &bpf_event_output_data_proto;
+ default:
+ return bpf_base_func_proto(func_id);
+ }
}
static bool cgroup_dev_is_valid_access(int off, int size,
@@ -865,16 +1663,13 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
* @head: sysctl table header
* @table: sysctl table
* @write: sysctl is being read (= 0) or written (= 1)
- * @buf: pointer to buffer passed by user space
+ * @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
- * @new_buf: pointer to pointer to new buffer that will be allocated if program
- * overrides new value provided by user space on sysctl write
- * NOTE: it's caller responsibility to free *new_buf if it was set
* @type: type of program to be executed
*
* Program is run when sysctl is being accessed, either read or written, and
@@ -885,9 +1680,8 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
*/
int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
struct ctl_table *table, int write,
- void __user *buf, size_t *pcount,
- loff_t *ppos, void **new_buf,
- enum bpf_attach_type type)
+ char **buf, size_t *pcount, loff_t *ppos,
+ enum cgroup_bpf_attach_type atype)
{
struct bpf_sysctl_kern ctx = {
.head = head,
@@ -901,75 +1695,71 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
.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) {
- mm_segment_t old_fs;
- loff_t pos = 0;
-
- old_fs = get_fs();
- set_fs(KERNEL_DS);
- if (table->proc_handler(table, 0, (void __user *)ctx.cur_val,
- &ctx.cur_len, &pos)) {
- /* Let BPF program decide how to proceed. */
- ctx.cur_len = 0;
- }
- set_fs(old_fs);
- } else {
+ 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) {
+ 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 ||
- copy_from_user(ctx.new_val, buf, ctx.new_len))
+ 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);
+ ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run, 0,
+ NULL);
rcu_read_unlock();
kfree(ctx.cur_val);
if (ret == 1 && ctx.new_updated) {
- *new_buf = ctx.new_val;
+ kfree(*buf);
+ *buf = ctx.new_val;
*pcount = ctx.new_len;
} else {
kfree(ctx.new_val);
}
- return ret == 1 ? 0 : -EPERM;
+ return ret;
}
-EXPORT_SYMBOL(__cgroup_bpf_run_filter_sysctl);
#ifdef CONFIG_NET
-static bool __cgroup_bpf_prog_array_is_empty(struct cgroup *cgrp,
- enum bpf_attach_type attach_type)
+static int sockopt_alloc_buf(struct bpf_sockopt_kern *ctx, int max_optlen,
+ struct bpf_sockopt_buf *buf)
{
- 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();
+ if (unlikely(max_optlen < 0))
+ return -EINVAL;
- return empty;
-}
+ 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;
+ }
-static int sockopt_alloc_buf(struct bpf_sockopt_kern *ctx, int max_optlen)
-{
- if (unlikely(max_optlen > PAGE_SIZE) || max_optlen < 0)
- return -EINVAL;
+ if (max_optlen <= sizeof(buf->data)) {
+ /* When the optval fits into BPF_SOCKOPT_KERN_BUF_SIZE
+ * bytes avoid the cost of kzalloc.
+ */
+ ctx->optval = buf->data;
+ ctx->optval_end = ctx->optval + max_optlen;
+ return max_optlen;
+ }
ctx->optval = kzalloc(max_optlen, GFP_USER);
if (!ctx->optval)
@@ -977,19 +1767,29 @@ static int sockopt_alloc_buf(struct bpf_sockopt_kern *ctx, int max_optlen)
ctx->optval_end = ctx->optval + max_optlen;
- return 0;
+ return max_optlen;
}
-static void sockopt_free_buf(struct bpf_sockopt_kern *ctx)
+static void sockopt_free_buf(struct bpf_sockopt_kern *ctx,
+ struct bpf_sockopt_buf *buf)
{
+ if (ctx->optval == buf->data)
+ return;
kfree(ctx->optval);
}
+static bool sockopt_buf_allocated(struct bpf_sockopt_kern *ctx,
+ struct bpf_sockopt_buf *buf)
+{
+ return ctx->optval != buf->data;
+}
+
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_buf buf = {};
struct bpf_sockopt_kern ctx = {
.sk = sk,
.level = *level,
@@ -997,40 +1797,29 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
};
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);
-
- ret = sockopt_alloc_buf(&ctx, max_optlen);
- if (ret)
- return ret;
+ max_optlen = sockopt_alloc_buf(&ctx, max_optlen, &buf);
+ if (max_optlen < 0)
+ return max_optlen;
ctx.optlen = *optlen;
- if (copy_from_user(ctx.optval, optval, *optlen) != 0) {
+ 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);
+ ret = bpf_prog_run_array_cg(&cgrp->bpf, CGROUP_SETSOCKOPT,
+ &ctx, bpf_prog_run, 0, NULL);
release_sock(sk);
- if (!ret) {
- ret = -EPERM;
+ if (ret)
goto out;
- }
if (ctx.optlen == -1) {
/* optlen set to -1, bypass kernel */
@@ -1045,16 +1834,39 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
/* export any potential modifications */
*level = ctx.level;
*optname = ctx.optname;
- *optlen = ctx.optlen;
- *kernel_optval = ctx.optval;
+
+ /* optlen == 0 from BPF indicates that we should
+ * use original userspace data.
+ */
+ if (ctx.optlen != 0) {
+ *optlen = ctx.optlen;
+ /* We've used bpf_sockopt_kern->buf as an intermediary
+ * storage, but the BPF program indicates that we need
+ * to pass this data to the kernel setsockopt handler.
+ * No way to export on-stack buf, have to allocate a
+ * new buffer.
+ */
+ if (!sockopt_buf_allocated(&ctx, &buf)) {
+ void *p = kmalloc(ctx.optlen, GFP_USER);
+
+ if (!p) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ memcpy(p, ctx.optval, ctx.optlen);
+ *kernel_optval = p;
+ } else {
+ *kernel_optval = ctx.optval;
+ }
+ /* export and don't free sockopt buf */
+ return 0;
+ }
}
out:
- if (ret)
- sockopt_free_buf(&ctx);
+ sockopt_free_buf(&ctx, &buf);
return ret;
}
-EXPORT_SYMBOL(__cgroup_bpf_run_filter_setsockopt);
int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
int optname, char __user *optval,
@@ -1062,27 +1874,19 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
int retval)
{
struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+ struct bpf_sockopt_buf buf = {};
struct bpf_sockopt_kern ctx = {
.sk = sk,
.level = level,
.optname = optname,
- .retval = retval,
+ .current_task = current,
};
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;
-
- ret = sockopt_alloc_buf(&ctx, max_optlen);
- if (ret)
- return ret;
-
ctx.optlen = max_optlen;
+ max_optlen = sockopt_alloc_buf(&ctx, max_optlen, &buf);
+ if (max_optlen < 0)
+ return max_optlen;
if (!retval) {
/* If kernel getsockopt finished successfully,
@@ -1097,51 +1901,83 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
goto out;
}
- if (ctx.optlen > max_optlen)
- ctx.optlen = max_optlen;
+ if (ctx.optlen < 0) {
+ ret = -EFAULT;
+ goto out;
+ }
- if (copy_from_user(ctx.optval, optval, ctx.optlen) != 0) {
+ 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);
+ ret = bpf_prog_run_array_cg(&cgrp->bpf, CGROUP_GETSOCKOPT,
+ &ctx, bpf_prog_run, retval, NULL);
release_sock(sk);
- if (!ret) {
- ret = -EPERM;
+ if (ret < 0)
goto out;
- }
- if (ctx.optlen > max_optlen) {
+ if (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 (copy_to_user(optval, ctx.optval, ctx.optlen) ||
+ put_user(ctx.optlen, optlen)) {
+ ret = -EFAULT;
+ goto out;
+ }
}
- if (copy_to_user(optval, ctx.optval, ctx.optlen) ||
- put_user(ctx.optlen, optlen)) {
- ret = -EFAULT;
- goto out;
- }
+out:
+ sockopt_free_buf(&ctx, &buf);
+ return ret;
+}
- ret = ctx.retval;
+int __cgroup_bpf_run_filter_getsockopt_kern(struct sock *sk, int level,
+ int optname, void *optval,
+ int *optlen, int retval)
+{
+ struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+ struct bpf_sockopt_kern ctx = {
+ .sk = sk,
+ .level = level,
+ .optname = optname,
+ .optlen = *optlen,
+ .optval = optval,
+ .optval_end = optval + *optlen,
+ .current_task = current,
+ };
+ int ret;
+
+ /* Note that __cgroup_bpf_run_filter_getsockopt doesn't copy
+ * user data back into BPF buffer when reval != 0. This is
+ * done as an optimization to avoid extra copy, assuming
+ * kernel won't populate the data in case of an error.
+ * Here we always pass the data and memset() should
+ * be called if that data shouldn't be "exported".
+ */
+
+ ret = bpf_prog_run_array_cg(&cgrp->bpf, CGROUP_GETSOCKOPT,
+ &ctx, bpf_prog_run, retval, NULL);
+ if (ret < 0)
+ return ret;
+
+ if (ctx.optlen > *optlen)
+ return -EFAULT;
+
+ /* BPF programs can shrink the buffer, export the modifications.
+ */
+ if (ctx.optlen != 0)
+ *optlen = ctx.optlen;
-out:
- sockopt_free_buf(&ctx);
return ret;
}
-EXPORT_SYMBOL(__cgroup_bpf_run_filter_getsockopt);
#endif
static ssize_t sysctl_cpy_dir(const struct ctl_dir *dir, char **bufp,
@@ -1288,18 +2124,24 @@ static const struct bpf_func_proto bpf_sysctl_set_new_value_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.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)
{
+ const struct bpf_func_proto *func_proto;
+
+ func_proto = cgroup_common_func_proto(func_id, prog);
+ if (func_proto)
+ return func_proto;
+
+ func_proto = cgroup_current_func_proto(func_id, prog);
+ if (func_proto)
+ return func_proto;
+
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:
@@ -1308,8 +2150,12 @@ sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_sysctl_get_new_value_proto;
case BPF_FUNC_sysctl_set_new_value:
return &bpf_sysctl_set_new_value_proto;
+ case BPF_FUNC_ktime_get_coarse_ns:
+ return &bpf_ktime_get_coarse_ns_proto;
+ case BPF_FUNC_perf_event_output:
+ return &bpf_event_output_data_proto;
default:
- return cgroup_base_func_proto(func_id, prog);
+ return bpf_base_func_proto(func_id);
}
}
@@ -1411,22 +2257,60 @@ const struct bpf_verifier_ops cg_sysctl_verifier_ops = {
const struct bpf_prog_ops cg_sysctl_prog_ops = {
};
+#ifdef CONFIG_NET
+BPF_CALL_1(bpf_get_netns_cookie_sockopt, struct bpf_sockopt_kern *, ctx)
+{
+ const struct net *net = ctx ? sock_net(ctx->sk) : &init_net;
+
+ return net->net_cookie;
+}
+
+static const struct bpf_func_proto bpf_get_netns_cookie_sockopt_proto = {
+ .func = bpf_get_netns_cookie_sockopt,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX_OR_NULL,
+};
+#endif
+
static const struct bpf_func_proto *
cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
+ const struct bpf_func_proto *func_proto;
+
+ func_proto = cgroup_common_func_proto(func_id, prog);
+ if (func_proto)
+ return func_proto;
+
+ func_proto = cgroup_current_func_proto(func_id, prog);
+ if (func_proto)
+ return func_proto;
+
switch (func_id) {
#ifdef CONFIG_NET
+ case BPF_FUNC_get_netns_cookie:
+ return &bpf_get_netns_cookie_sockopt_proto;
case BPF_FUNC_sk_storage_get:
return &bpf_sk_storage_get_proto;
case BPF_FUNC_sk_storage_delete:
return &bpf_sk_storage_delete_proto;
+ case BPF_FUNC_setsockopt:
+ if (prog->expected_attach_type == BPF_CGROUP_SETSOCKOPT)
+ return &bpf_sk_setsockopt_proto;
+ return NULL;
+ case BPF_FUNC_getsockopt:
+ if (prog->expected_attach_type == BPF_CGROUP_SETSOCKOPT)
+ return &bpf_sk_getsockopt_proto;
+ return NULL;
#endif
#ifdef CONFIG_INET
case BPF_FUNC_tcp_sock:
return &bpf_tcp_sock_proto;
#endif
+ case BPF_FUNC_perf_event_output:
+ return &bpf_event_output_data_proto;
default:
- return cgroup_base_func_proto(func_id, prog);
+ return bpf_base_func_proto(func_id);
}
}
@@ -1451,7 +2335,7 @@ static bool cg_sockopt_is_valid_access(int off, int size,
return prog->expected_attach_type ==
BPF_CGROUP_GETSOCKOPT;
case offsetof(struct bpf_sockopt, optname):
- /* fallthrough */
+ fallthrough;
case offsetof(struct bpf_sockopt, level):
if (size != size_default)
return false;
@@ -1528,10 +2412,39 @@ static u32 cg_sockopt_convert_ctx_access(enum bpf_access_type type,
*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);
+ BUILD_BUG_ON(offsetof(struct bpf_cg_run_ctx, run_ctx) != 0);
+
+ 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_sockopt_kern, tmp_reg));
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, current_task),
+ treg, si->dst_reg,
+ offsetof(struct bpf_sockopt_kern, current_task));
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct task_struct, bpf_ctx),
+ treg, treg,
+ offsetof(struct task_struct, bpf_ctx));
+ *insn++ = BPF_STX_MEM(BPF_FIELD_SIZEOF(struct bpf_cg_run_ctx, retval),
+ treg, si->src_reg,
+ offsetof(struct bpf_cg_run_ctx, retval));
+ *insn++ = BPF_LDX_MEM(BPF_DW, treg, si->dst_reg,
+ offsetof(struct bpf_sockopt_kern, tmp_reg));
+ } else {
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, current_task),
+ si->dst_reg, si->src_reg,
+ offsetof(struct bpf_sockopt_kern, current_task));
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct task_struct, bpf_ctx),
+ si->dst_reg, si->dst_reg,
+ offsetof(struct task_struct, bpf_ctx));
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_cg_run_ctx, retval),
+ si->dst_reg, si->dst_reg,
+ offsetof(struct bpf_cg_run_ctx, retval));
+ }
break;
case offsetof(struct bpf_sockopt, optval):
*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optval);
@@ -1562,3 +2475,69 @@ const struct bpf_verifier_ops cg_sockopt_verifier_ops = {
const struct bpf_prog_ops cg_sockopt_prog_ops = {
};
+
+/* Common helpers for cgroup hooks. */
+const struct bpf_func_proto *
+cgroup_common_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+ switch (func_id) {
+ case BPF_FUNC_get_local_storage:
+ return &bpf_get_local_storage_proto;
+ case BPF_FUNC_get_retval:
+ switch (prog->expected_attach_type) {
+ case BPF_CGROUP_INET_INGRESS:
+ case BPF_CGROUP_INET_EGRESS:
+ case BPF_CGROUP_SOCK_OPS:
+ case BPF_CGROUP_UDP4_RECVMSG:
+ case BPF_CGROUP_UDP6_RECVMSG:
+ case BPF_CGROUP_INET4_GETPEERNAME:
+ case BPF_CGROUP_INET6_GETPEERNAME:
+ case BPF_CGROUP_INET4_GETSOCKNAME:
+ case BPF_CGROUP_INET6_GETSOCKNAME:
+ return NULL;
+ default:
+ return &bpf_get_retval_proto;
+ }
+ case BPF_FUNC_set_retval:
+ switch (prog->expected_attach_type) {
+ case BPF_CGROUP_INET_INGRESS:
+ case BPF_CGROUP_INET_EGRESS:
+ case BPF_CGROUP_SOCK_OPS:
+ case BPF_CGROUP_UDP4_RECVMSG:
+ case BPF_CGROUP_UDP6_RECVMSG:
+ case BPF_CGROUP_INET4_GETPEERNAME:
+ case BPF_CGROUP_INET6_GETPEERNAME:
+ case BPF_CGROUP_INET4_GETSOCKNAME:
+ case BPF_CGROUP_INET6_GETSOCKNAME:
+ return NULL;
+ default:
+ return &bpf_set_retval_proto;
+ }
+ default:
+ return NULL;
+ }
+}
+
+/* Common helpers for cgroup hooks with valid process context. */
+const struct bpf_func_proto *
+cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+ switch (func_id) {
+ case BPF_FUNC_get_current_uid_gid:
+ return &bpf_get_current_uid_gid_proto;
+ case BPF_FUNC_get_current_pid_tgid:
+ return &bpf_get_current_pid_tgid_proto;
+ case BPF_FUNC_get_current_comm:
+ return &bpf_get_current_comm_proto;
+ case BPF_FUNC_get_current_cgroup_id:
+ return &bpf_get_current_cgroup_id_proto;
+ case BPF_FUNC_get_current_ancestor_cgroup_id:
+ return &bpf_get_current_ancestor_cgroup_id_proto;
+#ifdef CONFIG_CGROUP_NET_CLASSID
+ case BPF_FUNC_get_cgroup_classid:
+ return &bpf_get_cgroup_classid_curr_proto;
+#endif
+ default:
+ return NULL;
+ }
+}