// SPDX-License-Identifier: GPL-2.0/* * Copyright (c) 2019 Facebook * Copyright 2020 Google LLC. */ #include <linux/rculist.h>#include <linux/list.h>#include <linux/hash.h>#include <linux/types.h>#include <linux/spinlock.h>#include <linux/bpf.h>#include <linux/bpf_local_storage.h>#include <net/sock.h>#include <uapi/linux/sock_diag.h>#include <uapi/linux/btf.h>#include <linux/bpf_lsm.h>#include <linux/btf_ids.h>#include <linux/rcupdate_trace.h> DEFINE_BPF_STORAGE_CACHE(inode_cache); static struct bpf_local_storage __rcu **inode_storage_ptr(void *owner){	struct inode *inode = owner;	struct bpf_storage_blob *bsb; 	bsb = bpf_inode(inode);	if (!bsb)		return NULL;	return &bsb->storage;} static struct bpf_local_storage_data *inode_storage_lookup(struct inode *inode,							   struct bpf_map *map,							   bool cacheit_lockit){	struct bpf_local_storage *inode_storage;	struct bpf_local_storage_map *smap;	struct bpf_storage_blob *bsb; 	bsb = bpf_inode(inode);	if (!bsb)		return NULL; 	inode_storage =		rcu_dereference_check(bsb->storage, bpf_rcu_lock_held());	if (!inode_storage)		return NULL; 	smap = (struct bpf_local_storage_map *)map;	return bpf_local_storage_lookup(inode_storage, smap, cacheit_lockit);} void bpf_inode_storage_free(struct inode *inode){	struct bpf_local_storage *local_storage;	struct bpf_storage_blob *bsb; 	bsb = bpf_inode(inode);	if (!bsb)		return; 	rcu_read_lock_dont_migrate(); 	local_storage = rcu_dereference(bsb->storage);	if (!local_storage)		goto out; 	bpf_local_storage_destroy(local_storage);out:	rcu_read_unlock_migrate();} static void *bpf_fd_inode_storage_lookup_elem(struct bpf_map *map, void *key){	struct bpf_local_storage_data *sdata;	CLASS(fd_raw, f)(*(int *)key); 	if (fd_empty(f))		return ERR_PTR(-EBADF); 	sdata = inode_storage_lookup(file_inode(fd_file(f)), map, true);	return sdata ? sdata->data : NULL;} static long bpf_fd_inode_storage_update_elem(struct bpf_map *map, void *key,					     void *value, u64 map_flags){	struct bpf_local_storage_data *sdata;	CLASS(fd_raw, f)(*(int *)key); 	if (fd_empty(f))		return -EBADF;	if (!inode_storage_ptr(file_inode(fd_file(f))))		return -EBADF; 	sdata = bpf_local_storage_update(file_inode(fd_file(f)),					 (struct bpf_local_storage_map *)map,					 value, map_flags, false);	return PTR_ERR_OR_ZERO(sdata);} static int inode_storage_delete(struct inode *inode, struct bpf_map *map){	struct bpf_local_storage_data *sdata; 	sdata = inode_storage_lookup(inode, map, false);	if (!sdata)		return -ENOENT; 	return bpf_selem_unlink(SELEM(sdata));} static long bpf_fd_inode_storage_delete_elem(struct bpf_map *map, void *key){	CLASS(fd_raw, f)(*(int *)key); 	if (fd_empty(f))		return -EBADF;	return inode_storage_delete(file_inode(fd_file(f)), map);} BPF_CALL_4(bpf_inode_storage_get, struct bpf_map *, map, struct inode *, inode,	   void *, value, u64, flags){	struct bpf_local_storage_data *sdata; 	WARN_ON_ONCE(!bpf_rcu_lock_held());	if (flags & ~(BPF_LOCAL_STORAGE_GET_F_CREATE))		return (unsigned long)NULL; 	/* explicitly check that the inode_storage_ptr is not	 * NULL as inode_storage_lookup returns NULL in this case and	 * bpf_local_storage_update expects the owner to have a	 * valid storage pointer.	 */	if (!inode || !inode_storage_ptr(inode))		return (unsigned long)NULL; 	sdata = inode_storage_lookup(inode, map, true);	if (sdata)		return (unsigned long)sdata->data; 	/* This helper must only called from where the inode is guaranteed	 * to have a refcount and cannot be freed.	 */	if (flags & BPF_LOCAL_STORAGE_GET_F_CREATE) {		sdata = bpf_local_storage_update(			inode, (struct bpf_local_storage_map *)map, value,			BPF_NOEXIST, false);		return IS_ERR(sdata) ? (unsigned long)NULL :					     (unsigned long)sdata->data;	} 	return (unsigned long)NULL;} BPF_CALL_2(bpf_inode_storage_delete,	   struct bpf_map *, map, struct inode *, inode){	WARN_ON_ONCE(!bpf_rcu_lock_held());	if (!inode)		return -EINVAL; 	/* This helper must only called from where the inode is guaranteed	 * to have a refcount and cannot be freed.	 */	return inode_storage_delete(inode, map);} static int notsupp_get_next_key(struct bpf_map *map, void *key,				void *next_key){	return -ENOTSUPP;} static struct bpf_map *inode_storage_map_alloc(union bpf_attr *attr){	/*	 * Do not allow allocation of BPF_MAP_TYPE_INODE_STORAGE if the BPF LSM	 * was not initialized by the LSM framework at boot. Without proper	 * initialization, the BPF inode security blob offset remains unprepared,	 * causing bpf_inode() to calculate an invalid memory offset and corrupt	 * inode->i_security.	 */	if (!bpf_lsm_initialized)		return ERR_PTR(-EOPNOTSUPP);	return bpf_local_storage_map_alloc(attr, &inode_cache);} static void inode_storage_map_free(struct bpf_map *map){	bpf_local_storage_map_free(map, &inode_cache);} const struct bpf_map_ops inode_storage_map_ops = {	.map_meta_equal = bpf_map_meta_equal,	.map_alloc_check = bpf_local_storage_map_alloc_check,	.map_alloc = inode_storage_map_alloc,	.map_free = inode_storage_map_free,	.map_get_next_key = notsupp_get_next_key,	.map_lookup_elem = bpf_fd_inode_storage_lookup_elem,	.map_update_elem = bpf_fd_inode_storage_update_elem,	.map_delete_elem = bpf_fd_inode_storage_delete_elem,	.map_check_btf = bpf_local_storage_map_check_btf,	.map_mem_usage = bpf_local_storage_map_mem_usage,	.map_btf_id = &bpf_local_storage_map_btf_id[0],	.map_owner_storage_ptr = inode_storage_ptr,}; BTF_ID_LIST_SINGLE(bpf_inode_storage_btf_ids, struct, inode) const struct bpf_func_proto bpf_inode_storage_get_proto = {	.func		= bpf_inode_storage_get,	.gpl_only	= false,	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,	.arg1_type	= ARG_CONST_MAP_PTR,	.arg2_type	= ARG_PTR_TO_BTF_ID_OR_NULL,	.arg2_btf_id	= &bpf_inode_storage_btf_ids[0],	.arg3_type	= ARG_PTR_TO_MAP_VALUE_OR_NULL,	.arg4_type	= ARG_ANYTHING,}; const struct bpf_func_proto bpf_inode_storage_delete_proto = {	.func		= bpf_inode_storage_delete,	.gpl_only	= false,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_CONST_MAP_PTR,	.arg2_type	= ARG_PTR_TO_BTF_ID_OR_NULL,	.arg2_btf_id	= &bpf_inode_storage_btf_ids[0],};