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
bch2_checksum_mergeable(unsigned type)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
bch2_csum_to_text(struct printbuf * out,enum bch_csum_type type,struct bch_csum csum)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
bch2_csum_err_msg(struct printbuf * out,enum bch_csum_type type,struct bch_csum expected,struct bch_csum got)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 void bch2_chacha20(const struct bch_key *, struct nonce, void *, size_t);
73
74 int bch2_request_key(struct bch_sb *, struct bch_key *);
75 #ifndef __KERNEL__
76 int bch2_revoke_key(struct bch_sb *);
77 #endif
78
79 int bch2_encrypt(struct bch_fs *, unsigned, struct nonce,
80 void *data, size_t);
81
82 struct bch_csum bch2_checksum_bio(struct bch_fs *, unsigned,
83 struct nonce, struct bio *);
84
85 int bch2_rechecksum_bio(struct bch_fs *, struct bio *, struct bversion,
86 struct bch_extent_crc_unpacked,
87 struct bch_extent_crc_unpacked *,
88 struct bch_extent_crc_unpacked *,
89 unsigned, unsigned, unsigned);
90
91 int __bch2_encrypt_bio(struct bch_fs *, unsigned,
92 struct nonce, struct bio *);
93
bch2_encrypt_bio(struct bch_fs * c,unsigned type,struct nonce nonce,struct bio * bio)94 static inline int bch2_encrypt_bio(struct bch_fs *c, unsigned type,
95 struct nonce nonce, struct bio *bio)
96 {
97 return bch2_csum_type_is_encryption(type)
98 ? __bch2_encrypt_bio(c, type, nonce, bio)
99 : 0;
100 }
101
102 extern const struct bch_sb_field_ops bch_sb_field_ops_crypt;
103
104 int bch2_decrypt_sb_key(struct bch_fs *, struct bch_sb_field_crypt *,
105 struct bch_key *);
106
107 #if 0
108 int bch2_disable_encryption(struct bch_fs *);
109 int bch2_enable_encryption(struct bch_fs *, bool);
110 #endif
111
112 void bch2_fs_encryption_exit(struct bch_fs *);
113 int bch2_fs_encryption_init(struct bch_fs *);
114
bch2_csum_opt_to_type(enum bch_csum_opt type,bool data)115 static inline enum bch_csum_type bch2_csum_opt_to_type(enum bch_csum_opt type,
116 bool data)
117 {
118 switch (type) {
119 case BCH_CSUM_OPT_none:
120 return BCH_CSUM_none;
121 case BCH_CSUM_OPT_crc32c:
122 return data ? BCH_CSUM_crc32c : BCH_CSUM_crc32c_nonzero;
123 case BCH_CSUM_OPT_crc64:
124 return data ? BCH_CSUM_crc64 : BCH_CSUM_crc64_nonzero;
125 case BCH_CSUM_OPT_xxhash:
126 return BCH_CSUM_xxhash;
127 default:
128 BUG();
129 }
130 }
131
bch2_data_checksum_type(struct bch_fs * c,struct bch_io_opts opts)132 static inline enum bch_csum_type bch2_data_checksum_type(struct bch_fs *c,
133 struct bch_io_opts opts)
134 {
135 if (opts.nocow)
136 return 0;
137
138 if (c->sb.encryption_type)
139 return c->opts.wide_macs
140 ? BCH_CSUM_chacha20_poly1305_128
141 : BCH_CSUM_chacha20_poly1305_80;
142
143 return bch2_csum_opt_to_type(opts.data_checksum, true);
144 }
145
bch2_meta_checksum_type(struct bch_fs * c)146 static inline enum bch_csum_type bch2_meta_checksum_type(struct bch_fs *c)
147 {
148 if (c->sb.encryption_type)
149 return BCH_CSUM_chacha20_poly1305_128;
150
151 return bch2_csum_opt_to_type(c->opts.metadata_checksum, false);
152 }
153
bch2_checksum_type_valid(const struct bch_fs * c,unsigned type)154 static inline bool bch2_checksum_type_valid(const struct bch_fs *c,
155 unsigned type)
156 {
157 if (type >= BCH_CSUM_NR)
158 return false;
159
160 if (bch2_csum_type_is_encryption(type) && !c->chacha20_key_set)
161 return false;
162
163 return true;
164 }
165
166 /* returns true if not equal */
bch2_crc_cmp(struct bch_csum l,struct bch_csum r)167 static inline bool bch2_crc_cmp(struct bch_csum l, struct bch_csum r)
168 {
169 /*
170 * XXX: need some way of preventing the compiler from optimizing this
171 * into a form that isn't constant time..
172 */
173 return ((l.lo ^ r.lo) | (l.hi ^ r.hi)) != 0;
174 }
175
176 /* for skipping ahead and encrypting/decrypting at an offset: */
nonce_add(struct nonce nonce,unsigned offset)177 static inline struct nonce nonce_add(struct nonce nonce, unsigned offset)
178 {
179 EBUG_ON(offset & (CHACHA_BLOCK_SIZE - 1));
180
181 le32_add_cpu(&nonce.d[0], offset / CHACHA_BLOCK_SIZE);
182 return nonce;
183 }
184
null_nonce(void)185 static inline struct nonce null_nonce(void)
186 {
187 struct nonce ret;
188
189 memset(&ret, 0, sizeof(ret));
190 return ret;
191 }
192
extent_nonce(struct bversion version,struct bch_extent_crc_unpacked crc)193 static inline struct nonce extent_nonce(struct bversion version,
194 struct bch_extent_crc_unpacked crc)
195 {
196 unsigned compression_type = crc_is_compressed(crc)
197 ? crc.compression_type
198 : 0;
199 unsigned size = compression_type ? crc.uncompressed_size : 0;
200 struct nonce nonce = (struct nonce) {{
201 [0] = cpu_to_le32(size << 22),
202 [1] = cpu_to_le32(version.lo),
203 [2] = cpu_to_le32(version.lo >> 32),
204 [3] = cpu_to_le32(version.hi|
205 (compression_type << 24))^BCH_NONCE_EXTENT,
206 }};
207
208 return nonce_add(nonce, crc.nonce << 9);
209 }
210
bch2_key_is_encrypted(struct bch_encrypted_key * key)211 static inline bool bch2_key_is_encrypted(struct bch_encrypted_key *key)
212 {
213 return le64_to_cpu(key->magic) != BCH_KEY_MAGIC;
214 }
215
__bch2_sb_key_nonce(struct bch_sb * sb)216 static inline struct nonce __bch2_sb_key_nonce(struct bch_sb *sb)
217 {
218 __le64 magic = __bch2_sb_magic(sb);
219
220 return (struct nonce) {{
221 [0] = 0,
222 [1] = 0,
223 [2] = ((__le32 *) &magic)[0],
224 [3] = ((__le32 *) &magic)[1],
225 }};
226 }
227
bch2_sb_key_nonce(struct bch_fs * c)228 static inline struct nonce bch2_sb_key_nonce(struct bch_fs *c)
229 {
230 __le64 magic = bch2_sb_magic(c);
231
232 return (struct nonce) {{
233 [0] = 0,
234 [1] = 0,
235 [2] = ((__le32 *) &magic)[0],
236 [3] = ((__le32 *) &magic)[1],
237 }};
238 }
239
240 #endif /* _BCACHEFS_CHECKSUM_H */
241