1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _BCACHEFS_CHECKSUM_H
3 #define _BCACHEFS_CHECKSUM_H
4
5 #include "bcachefs.h"
6 #include "extents_types.h"
7 #include "super-io.h"
8
9 #include <linux/crc64.h>
10 #include <crypto/chacha.h>
11
12 static inline bool bch2_checksum_mergeable(unsigned type)
13 {
14
15 switch (type) {
16 case BCH_CSUM_none:
17 case BCH_CSUM_crc32c:
18 case BCH_CSUM_crc64:
19 return true;
20 default:
21 return false;
22 }
23 }
24
25 struct bch_csum bch2_checksum_merge(unsigned, struct bch_csum,
26 struct bch_csum, size_t);
27
28 #define BCH_NONCE_EXTENT cpu_to_le32(1 << 28)
29 #define BCH_NONCE_BTREE cpu_to_le32(2 << 28)
30 #define BCH_NONCE_JOURNAL cpu_to_le32(3 << 28)
31 #define BCH_NONCE_PRIO cpu_to_le32(4 << 28)
32 #define BCH_NONCE_POLY cpu_to_le32(1 << 31)
33
34 struct bch_csum bch2_checksum(struct bch_fs *, unsigned, struct nonce,
35 const void *, size_t);
36
37 /*
38 * This is used for various on disk data structures - bch_sb, prio_set, bset,
39 * jset: The checksum is _always_ the first field of these structs
40 */
41 #define csum_vstruct(_c, _type, _nonce, _i) \
42 ({ \
43 const void *_start = ((const void *) (_i)) + sizeof((_i)->csum);\
44 \
45 bch2_checksum(_c, _type, _nonce, _start, vstruct_end(_i) - _start);\
46 })
47
48 static inline void bch2_csum_to_text(struct printbuf *out,
49 enum bch_csum_type type,
50 struct bch_csum csum)
51 {
52 const u8 *p = (u8 *) &csum;
53 unsigned bytes = type < BCH_CSUM_NR ? bch_crc_bytes[type] : 16;
54
55 for (unsigned i = 0; i < bytes; i++)
56 prt_hex_byte(out, p[i]);
57 }
58
59 static inline void bch2_csum_err_msg(struct printbuf *out,
60 enum bch_csum_type type,
61 struct bch_csum expected,
62 struct bch_csum got)
63 {
64 prt_str(out, "checksum error, type ");
65 bch2_prt_csum_type(out, type);
66 prt_str(out, ": got ");
67 bch2_csum_to_text(out, type, got);
68 prt_str(out, " should be ");
69 bch2_csum_to_text(out, type, expected);
70 }
71
72 int bch2_chacha_encrypt_key(struct bch_key *, struct nonce, void *, size_t);
73 int bch2_request_key(struct bch_sb *, struct bch_key *);
74 #ifndef __KERNEL__
75 int bch2_revoke_key(struct bch_sb *);
76 #endif
77
78 int bch2_encrypt(struct bch_fs *, unsigned, struct nonce,
79 void *data, size_t);
80
81 struct bch_csum bch2_checksum_bio(struct bch_fs *, unsigned,
82 struct nonce, struct bio *);
83
84 int bch2_rechecksum_bio(struct bch_fs *, struct bio *, struct bversion,
85 struct bch_extent_crc_unpacked,
86 struct bch_extent_crc_unpacked *,
87 struct bch_extent_crc_unpacked *,
88 unsigned, unsigned, unsigned);
89
90 int __bch2_encrypt_bio(struct bch_fs *, unsigned,
91 struct nonce, struct bio *);
92
93 static inline int bch2_encrypt_bio(struct bch_fs *c, unsigned type,
94 struct nonce nonce, struct bio *bio)
95 {
96 return bch2_csum_type_is_encryption(type)
97 ? __bch2_encrypt_bio(c, type, nonce, bio)
98 : 0;
99 }
100
101 extern const struct bch_sb_field_ops bch_sb_field_ops_crypt;
102
103 int bch2_decrypt_sb_key(struct bch_fs *, struct bch_sb_field_crypt *,
104 struct bch_key *);
105
106 int bch2_disable_encryption(struct bch_fs *);
107 int bch2_enable_encryption(struct bch_fs *, bool);
108
109 void bch2_fs_encryption_exit(struct bch_fs *);
110 int bch2_fs_encryption_init(struct bch_fs *);
111
112 static inline enum bch_csum_type bch2_csum_opt_to_type(enum bch_csum_opts type,
113 bool data)
114 {
115 switch (type) {
116 case BCH_CSUM_OPT_none:
117 return BCH_CSUM_none;
118 case BCH_CSUM_OPT_crc32c:
119 return data ? BCH_CSUM_crc32c : BCH_CSUM_crc32c_nonzero;
120 case BCH_CSUM_OPT_crc64:
121 return data ? BCH_CSUM_crc64 : BCH_CSUM_crc64_nonzero;
122 case BCH_CSUM_OPT_xxhash:
123 return BCH_CSUM_xxhash;
124 default:
125 BUG();
126 }
127 }
128
129 static inline enum bch_csum_type bch2_data_checksum_type(struct bch_fs *c,
130 struct bch_io_opts opts)
131 {
132 if (opts.nocow)
133 return 0;
134
135 if (c->sb.encryption_type)
136 return c->opts.wide_macs
137 ? BCH_CSUM_chacha20_poly1305_128
138 : BCH_CSUM_chacha20_poly1305_80;
139
140 return bch2_csum_opt_to_type(opts.data_checksum, true);
141 }
142
143 static inline enum bch_csum_type bch2_meta_checksum_type(struct bch_fs *c)
144 {
145 if (c->sb.encryption_type)
146 return BCH_CSUM_chacha20_poly1305_128;
147
148 return bch2_csum_opt_to_type(c->opts.metadata_checksum, false);
149 }
150
151 static inline bool bch2_checksum_type_valid(const struct bch_fs *c,
152 unsigned type)
153 {
154 if (type >= BCH_CSUM_NR)
155 return false;
156
157 if (bch2_csum_type_is_encryption(type) && !c->chacha20)
158 return false;
159
160 return true;
161 }
162
163 /* returns true if not equal */
164 static inline bool bch2_crc_cmp(struct bch_csum l, struct bch_csum r)
165 {
166 /*
167 * XXX: need some way of preventing the compiler from optimizing this
168 * into a form that isn't constant time..
169 */
170 return ((l.lo ^ r.lo) | (l.hi ^ r.hi)) != 0;
171 }
172
173 /* for skipping ahead and encrypting/decrypting at an offset: */
174 static inline struct nonce nonce_add(struct nonce nonce, unsigned offset)
175 {
176 EBUG_ON(offset & (CHACHA_BLOCK_SIZE - 1));
177
178 le32_add_cpu(&nonce.d[0], offset / CHACHA_BLOCK_SIZE);
179 return nonce;
180 }
181
182 static inline struct nonce null_nonce(void)
183 {
184 struct nonce ret;
185
186 memset(&ret, 0, sizeof(ret));
187 return ret;
188 }
189
190 static inline struct nonce extent_nonce(struct bversion version,
191 struct bch_extent_crc_unpacked crc)
192 {
193 unsigned compression_type = crc_is_compressed(crc)
194 ? crc.compression_type
195 : 0;
196 unsigned size = compression_type ? crc.uncompressed_size : 0;
197 struct nonce nonce = (struct nonce) {{
198 [0] = cpu_to_le32(size << 22),
199 [1] = cpu_to_le32(version.lo),
200 [2] = cpu_to_le32(version.lo >> 32),
201 [3] = cpu_to_le32(version.hi|
202 (compression_type << 24))^BCH_NONCE_EXTENT,
203 }};
204
205 return nonce_add(nonce, crc.nonce << 9);
206 }
207
208 static inline bool bch2_key_is_encrypted(struct bch_encrypted_key *key)
209 {
210 return le64_to_cpu(key->magic) != BCH_KEY_MAGIC;
211 }
212
213 static inline struct nonce __bch2_sb_key_nonce(struct bch_sb *sb)
214 {
215 __le64 magic = __bch2_sb_magic(sb);
216
217 return (struct nonce) {{
218 [0] = 0,
219 [1] = 0,
220 [2] = ((__le32 *) &magic)[0],
221 [3] = ((__le32 *) &magic)[1],
222 }};
223 }
224
225 static inline struct nonce bch2_sb_key_nonce(struct bch_fs *c)
226 {
227 __le64 magic = bch2_sb_magic(c);
228
229 return (struct nonce) {{
230 [0] = 0,
231 [1] = 0,
232 [2] = ((__le32 *) &magic)[0],
233 [3] = ((__le32 *) &magic)[1],
234 }};
235 }
236
237 #endif /* _BCACHEFS_CHECKSUM_H */
238
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