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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2019 Facebook
4 * Copyright 2020 Google LLC.
5 */
6
7#include <linux/rculist.h>
8#include <linux/list.h>
9#include <linux/hash.h>
10#include <linux/types.h>
11#include <linux/spinlock.h>
12#include <linux/bpf.h>
13#include <linux/bpf_local_storage.h>
14#include <net/sock.h>
15#include <uapi/linux/sock_diag.h>
16#include <uapi/linux/btf.h>
17#include <linux/bpf_lsm.h>
18#include <linux/btf_ids.h>
19#include <linux/fdtable.h>
20#include <linux/rcupdate_trace.h>
21
22DEFINE_BPF_STORAGE_CACHE(inode_cache);
23
24static struct bpf_local_storage __rcu **
25inode_storage_ptr(void *owner)
26{
27 struct inode *inode = owner;
28 struct bpf_storage_blob *bsb;
29
30 bsb = bpf_inode(inode);
31 if (!bsb)
32 return NULL;
33 return &bsb->storage;
34}
35
36static struct bpf_local_storage_data *inode_storage_lookup(struct inode *inode,
37 struct bpf_map *map,
38 bool cacheit_lockit)
39{
40 struct bpf_local_storage *inode_storage;
41 struct bpf_local_storage_map *smap;
42 struct bpf_storage_blob *bsb;
43
44 bsb = bpf_inode(inode);
45 if (!bsb)
46 return NULL;
47
48 inode_storage =
49 rcu_dereference_check(bsb->storage, bpf_rcu_lock_held());
50 if (!inode_storage)
51 return NULL;
52
53 smap = (struct bpf_local_storage_map *)map;
54 return bpf_local_storage_lookup(inode_storage, smap, cacheit_lockit);
55}
56
57void bpf_inode_storage_free(struct inode *inode)
58{
59 struct bpf_local_storage *local_storage;
60 struct bpf_storage_blob *bsb;
61
62 bsb = bpf_inode(inode);
63 if (!bsb)
64 return;
65
66 rcu_read_lock();
67
68 local_storage = rcu_dereference(bsb->storage);
69 if (!local_storage) {
70 rcu_read_unlock();
71 return;
72 }
73
74 bpf_local_storage_destroy(local_storage);
75 rcu_read_unlock();
76}
77
78static void *bpf_fd_inode_storage_lookup_elem(struct bpf_map *map, void *key)
79{
80 struct bpf_local_storage_data *sdata;
81 struct fd f = fdget_raw(*(int *)key);
82
83 if (!f.file)
84 return ERR_PTR(-EBADF);
85
86 sdata = inode_storage_lookup(file_inode(f.file), map, true);
87 fdput(f);
88 return sdata ? sdata->data : NULL;
89}
90
91static long bpf_fd_inode_storage_update_elem(struct bpf_map *map, void *key,
92 void *value, u64 map_flags)
93{
94 struct bpf_local_storage_data *sdata;
95 struct fd f = fdget_raw(*(int *)key);
96
97 if (!f.file)
98 return -EBADF;
99 if (!inode_storage_ptr(file_inode(f.file))) {
100 fdput(f);
101 return -EBADF;
102 }
103
104 sdata = bpf_local_storage_update(file_inode(f.file),
105 (struct bpf_local_storage_map *)map,
106 value, map_flags, GFP_ATOMIC);
107 fdput(f);
108 return PTR_ERR_OR_ZERO(sdata);
109}
110
111static int inode_storage_delete(struct inode *inode, struct bpf_map *map)
112{
113 struct bpf_local_storage_data *sdata;
114
115 sdata = inode_storage_lookup(inode, map, false);
116 if (!sdata)
117 return -ENOENT;
118
119 bpf_selem_unlink(SELEM(sdata), false);
120
121 return 0;
122}
123
124static long bpf_fd_inode_storage_delete_elem(struct bpf_map *map, void *key)
125{
126 struct fd f = fdget_raw(*(int *)key);
127 int err;
128
129 if (!f.file)
130 return -EBADF;
131
132 err = inode_storage_delete(file_inode(f.file), map);
133 fdput(f);
134 return err;
135}
136
137/* *gfp_flags* is a hidden argument provided by the verifier */
138BPF_CALL_5(bpf_inode_storage_get, struct bpf_map *, map, struct inode *, inode,
139 void *, value, u64, flags, gfp_t, gfp_flags)
140{
141 struct bpf_local_storage_data *sdata;
142
143 WARN_ON_ONCE(!bpf_rcu_lock_held());
144 if (flags & ~(BPF_LOCAL_STORAGE_GET_F_CREATE))
145 return (unsigned long)NULL;
146
147 /* explicitly check that the inode_storage_ptr is not
148 * NULL as inode_storage_lookup returns NULL in this case and
149 * bpf_local_storage_update expects the owner to have a
150 * valid storage pointer.
151 */
152 if (!inode || !inode_storage_ptr(inode))
153 return (unsigned long)NULL;
154
155 sdata = inode_storage_lookup(inode, map, true);
156 if (sdata)
157 return (unsigned long)sdata->data;
158
159 /* This helper must only called from where the inode is guaranteed
160 * to have a refcount and cannot be freed.
161 */
162 if (flags & BPF_LOCAL_STORAGE_GET_F_CREATE) {
163 sdata = bpf_local_storage_update(
164 inode, (struct bpf_local_storage_map *)map, value,
165 BPF_NOEXIST, gfp_flags);
166 return IS_ERR(sdata) ? (unsigned long)NULL :
167 (unsigned long)sdata->data;
168 }
169
170 return (unsigned long)NULL;
171}
172
173BPF_CALL_2(bpf_inode_storage_delete,
174 struct bpf_map *, map, struct inode *, inode)
175{
176 WARN_ON_ONCE(!bpf_rcu_lock_held());
177 if (!inode)
178 return -EINVAL;
179
180 /* This helper must only called from where the inode is guaranteed
181 * to have a refcount and cannot be freed.
182 */
183 return inode_storage_delete(inode, map);
184}
185
186static int notsupp_get_next_key(struct bpf_map *map, void *key,
187 void *next_key)
188{
189 return -ENOTSUPP;
190}
191
192static struct bpf_map *inode_storage_map_alloc(union bpf_attr *attr)
193{
194 return bpf_local_storage_map_alloc(attr, &inode_cache, false);
195}
196
197static void inode_storage_map_free(struct bpf_map *map)
198{
199 bpf_local_storage_map_free(map, &inode_cache, NULL);
200}
201
202const struct bpf_map_ops inode_storage_map_ops = {
203 .map_meta_equal = bpf_map_meta_equal,
204 .map_alloc_check = bpf_local_storage_map_alloc_check,
205 .map_alloc = inode_storage_map_alloc,
206 .map_free = inode_storage_map_free,
207 .map_get_next_key = notsupp_get_next_key,
208 .map_lookup_elem = bpf_fd_inode_storage_lookup_elem,
209 .map_update_elem = bpf_fd_inode_storage_update_elem,
210 .map_delete_elem = bpf_fd_inode_storage_delete_elem,
211 .map_check_btf = bpf_local_storage_map_check_btf,
212 .map_mem_usage = bpf_local_storage_map_mem_usage,
213 .map_btf_id = &bpf_local_storage_map_btf_id[0],
214 .map_owner_storage_ptr = inode_storage_ptr,
215};
216
217BTF_ID_LIST_SINGLE(bpf_inode_storage_btf_ids, struct, inode)
218
219const struct bpf_func_proto bpf_inode_storage_get_proto = {
220 .func = bpf_inode_storage_get,
221 .gpl_only = false,
222 .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
223 .arg1_type = ARG_CONST_MAP_PTR,
224 .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL,
225 .arg2_btf_id = &bpf_inode_storage_btf_ids[0],
226 .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
227 .arg4_type = ARG_ANYTHING,
228};
229
230const struct bpf_func_proto bpf_inode_storage_delete_proto = {
231 .func = bpf_inode_storage_delete,
232 .gpl_only = false,
233 .ret_type = RET_INTEGER,
234 .arg1_type = ARG_CONST_MAP_PTR,
235 .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL,
236 .arg2_btf_id = &bpf_inode_storage_btf_ids[0],
237};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2019 Facebook
4 * Copyright 2020 Google LLC.
5 */
6
7#include <linux/rculist.h>
8#include <linux/list.h>
9#include <linux/hash.h>
10#include <linux/types.h>
11#include <linux/spinlock.h>
12#include <linux/bpf.h>
13#include <linux/bpf_local_storage.h>
14#include <net/sock.h>
15#include <uapi/linux/sock_diag.h>
16#include <uapi/linux/btf.h>
17#include <linux/bpf_lsm.h>
18#include <linux/btf_ids.h>
19#include <linux/fdtable.h>
20#include <linux/rcupdate_trace.h>
21
22DEFINE_BPF_STORAGE_CACHE(inode_cache);
23
24static struct bpf_local_storage __rcu **
25inode_storage_ptr(void *owner)
26{
27 struct inode *inode = owner;
28 struct bpf_storage_blob *bsb;
29
30 bsb = bpf_inode(inode);
31 if (!bsb)
32 return NULL;
33 return &bsb->storage;
34}
35
36static struct bpf_local_storage_data *inode_storage_lookup(struct inode *inode,
37 struct bpf_map *map,
38 bool cacheit_lockit)
39{
40 struct bpf_local_storage *inode_storage;
41 struct bpf_local_storage_map *smap;
42 struct bpf_storage_blob *bsb;
43
44 bsb = bpf_inode(inode);
45 if (!bsb)
46 return NULL;
47
48 inode_storage =
49 rcu_dereference_check(bsb->storage, bpf_rcu_lock_held());
50 if (!inode_storage)
51 return NULL;
52
53 smap = (struct bpf_local_storage_map *)map;
54 return bpf_local_storage_lookup(inode_storage, smap, cacheit_lockit);
55}
56
57void bpf_inode_storage_free(struct inode *inode)
58{
59 struct bpf_local_storage *local_storage;
60 bool free_inode_storage = false;
61 struct bpf_storage_blob *bsb;
62
63 bsb = bpf_inode(inode);
64 if (!bsb)
65 return;
66
67 rcu_read_lock();
68
69 local_storage = rcu_dereference(bsb->storage);
70 if (!local_storage) {
71 rcu_read_unlock();
72 return;
73 }
74
75 raw_spin_lock_bh(&local_storage->lock);
76 free_inode_storage = bpf_local_storage_unlink_nolock(local_storage);
77 raw_spin_unlock_bh(&local_storage->lock);
78 rcu_read_unlock();
79
80 if (free_inode_storage)
81 kfree_rcu(local_storage, rcu);
82}
83
84static void *bpf_fd_inode_storage_lookup_elem(struct bpf_map *map, void *key)
85{
86 struct bpf_local_storage_data *sdata;
87 struct file *f;
88 int fd;
89
90 fd = *(int *)key;
91 f = fget_raw(fd);
92 if (!f)
93 return ERR_PTR(-EBADF);
94
95 sdata = inode_storage_lookup(f->f_inode, map, true);
96 fput(f);
97 return sdata ? sdata->data : NULL;
98}
99
100static int bpf_fd_inode_storage_update_elem(struct bpf_map *map, void *key,
101 void *value, u64 map_flags)
102{
103 struct bpf_local_storage_data *sdata;
104 struct file *f;
105 int fd;
106
107 fd = *(int *)key;
108 f = fget_raw(fd);
109 if (!f)
110 return -EBADF;
111 if (!inode_storage_ptr(f->f_inode)) {
112 fput(f);
113 return -EBADF;
114 }
115
116 sdata = bpf_local_storage_update(f->f_inode,
117 (struct bpf_local_storage_map *)map,
118 value, map_flags, GFP_ATOMIC);
119 fput(f);
120 return PTR_ERR_OR_ZERO(sdata);
121}
122
123static int inode_storage_delete(struct inode *inode, struct bpf_map *map)
124{
125 struct bpf_local_storage_data *sdata;
126
127 sdata = inode_storage_lookup(inode, map, false);
128 if (!sdata)
129 return -ENOENT;
130
131 bpf_selem_unlink(SELEM(sdata), true);
132
133 return 0;
134}
135
136static int bpf_fd_inode_storage_delete_elem(struct bpf_map *map, void *key)
137{
138 struct file *f;
139 int fd, err;
140
141 fd = *(int *)key;
142 f = fget_raw(fd);
143 if (!f)
144 return -EBADF;
145
146 err = inode_storage_delete(f->f_inode, map);
147 fput(f);
148 return err;
149}
150
151/* *gfp_flags* is a hidden argument provided by the verifier */
152BPF_CALL_5(bpf_inode_storage_get, struct bpf_map *, map, struct inode *, inode,
153 void *, value, u64, flags, gfp_t, gfp_flags)
154{
155 struct bpf_local_storage_data *sdata;
156
157 WARN_ON_ONCE(!bpf_rcu_lock_held());
158 if (flags & ~(BPF_LOCAL_STORAGE_GET_F_CREATE))
159 return (unsigned long)NULL;
160
161 /* explicitly check that the inode_storage_ptr is not
162 * NULL as inode_storage_lookup returns NULL in this case and
163 * bpf_local_storage_update expects the owner to have a
164 * valid storage pointer.
165 */
166 if (!inode || !inode_storage_ptr(inode))
167 return (unsigned long)NULL;
168
169 sdata = inode_storage_lookup(inode, map, true);
170 if (sdata)
171 return (unsigned long)sdata->data;
172
173 /* This helper must only called from where the inode is guaranteed
174 * to have a refcount and cannot be freed.
175 */
176 if (flags & BPF_LOCAL_STORAGE_GET_F_CREATE) {
177 sdata = bpf_local_storage_update(
178 inode, (struct bpf_local_storage_map *)map, value,
179 BPF_NOEXIST, gfp_flags);
180 return IS_ERR(sdata) ? (unsigned long)NULL :
181 (unsigned long)sdata->data;
182 }
183
184 return (unsigned long)NULL;
185}
186
187BPF_CALL_2(bpf_inode_storage_delete,
188 struct bpf_map *, map, struct inode *, inode)
189{
190 WARN_ON_ONCE(!bpf_rcu_lock_held());
191 if (!inode)
192 return -EINVAL;
193
194 /* This helper must only called from where the inode is guaranteed
195 * to have a refcount and cannot be freed.
196 */
197 return inode_storage_delete(inode, map);
198}
199
200static int notsupp_get_next_key(struct bpf_map *map, void *key,
201 void *next_key)
202{
203 return -ENOTSUPP;
204}
205
206static struct bpf_map *inode_storage_map_alloc(union bpf_attr *attr)
207{
208 return bpf_local_storage_map_alloc(attr, &inode_cache);
209}
210
211static void inode_storage_map_free(struct bpf_map *map)
212{
213 bpf_local_storage_map_free(map, &inode_cache, NULL);
214}
215
216const struct bpf_map_ops inode_storage_map_ops = {
217 .map_meta_equal = bpf_map_meta_equal,
218 .map_alloc_check = bpf_local_storage_map_alloc_check,
219 .map_alloc = inode_storage_map_alloc,
220 .map_free = inode_storage_map_free,
221 .map_get_next_key = notsupp_get_next_key,
222 .map_lookup_elem = bpf_fd_inode_storage_lookup_elem,
223 .map_update_elem = bpf_fd_inode_storage_update_elem,
224 .map_delete_elem = bpf_fd_inode_storage_delete_elem,
225 .map_check_btf = bpf_local_storage_map_check_btf,
226 .map_btf_id = &bpf_local_storage_map_btf_id[0],
227 .map_owner_storage_ptr = inode_storage_ptr,
228};
229
230BTF_ID_LIST_SINGLE(bpf_inode_storage_btf_ids, struct, inode)
231
232const struct bpf_func_proto bpf_inode_storage_get_proto = {
233 .func = bpf_inode_storage_get,
234 .gpl_only = false,
235 .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
236 .arg1_type = ARG_CONST_MAP_PTR,
237 .arg2_type = ARG_PTR_TO_BTF_ID,
238 .arg2_btf_id = &bpf_inode_storage_btf_ids[0],
239 .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
240 .arg4_type = ARG_ANYTHING,
241};
242
243const struct bpf_func_proto bpf_inode_storage_delete_proto = {
244 .func = bpf_inode_storage_delete,
245 .gpl_only = false,
246 .ret_type = RET_INTEGER,
247 .arg1_type = ARG_CONST_MAP_PTR,
248 .arg2_type = ARG_PTR_TO_BTF_ID,
249 .arg2_btf_id = &bpf_inode_storage_btf_ids[0],
250};