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
12static 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
25struct 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
34struct 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
48static 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
59static 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
72int bch2_chacha_encrypt_key(struct bch_key *, struct nonce, void *, size_t);
73int bch2_request_key(struct bch_sb *, struct bch_key *);
74#ifndef __KERNEL__
75int bch2_revoke_key(struct bch_sb *);
76#endif
77
78int bch2_encrypt(struct bch_fs *, unsigned, struct nonce,
79		 void *data, size_t);
80
81struct bch_csum bch2_checksum_bio(struct bch_fs *, unsigned,
82				  struct nonce, struct bio *);
83
84int 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
90int __bch2_encrypt_bio(struct bch_fs *, unsigned,
91		       struct nonce, struct bio *);
92
93static 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
101extern const struct bch_sb_field_ops bch_sb_field_ops_crypt;
102
103int bch2_decrypt_sb_key(struct bch_fs *, struct bch_sb_field_crypt *,
104			struct bch_key *);
105
106int bch2_disable_encryption(struct bch_fs *);
107int bch2_enable_encryption(struct bch_fs *, bool);
108
109void bch2_fs_encryption_exit(struct bch_fs *);
110int bch2_fs_encryption_init(struct bch_fs *);
111
112static 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
129static 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
143static 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
151static 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 */
164static 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: */
174static 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
182static inline struct nonce null_nonce(void)
183{
184	struct nonce ret;
185
186	memset(&ret, 0, sizeof(ret));
187	return ret;
188}
189
190static 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
208static inline bool bch2_key_is_encrypted(struct bch_encrypted_key *key)
209{
210	return le64_to_cpu(key->magic) != BCH_KEY_MAGIC;
211}
212
213static 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
225static 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