diff options
Diffstat (limited to 'fs/bcachefs/checksum.h')
| -rw-r--r-- | fs/bcachefs/checksum.h | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/fs/bcachefs/checksum.h b/fs/bcachefs/checksum.h new file mode 100644 index 000000000000..42c86466293e --- /dev/null +++ b/fs/bcachefs/checksum.h @@ -0,0 +1,184 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _BCACHEFS_CHECKSUM_H +#define _BCACHEFS_CHECKSUM_H + +#include "bcachefs.h" +#include "extents_types.h" +#include "super-io.h" + +#include <crypto/chacha.h> + +u64 bch2_crc64_update(u64, const void *, size_t); + +#define BCH_NONCE_EXTENT cpu_to_le32(1 << 28) +#define BCH_NONCE_BTREE cpu_to_le32(2 << 28) +#define BCH_NONCE_JOURNAL cpu_to_le32(3 << 28) +#define BCH_NONCE_PRIO cpu_to_le32(4 << 28) +#define BCH_NONCE_POLY cpu_to_le32(1 << 31) + +struct bch_csum bch2_checksum(struct bch_fs *, unsigned, struct nonce, + const void *, size_t); + +/* + * This is used for various on disk data structures - bch_sb, prio_set, bset, + * jset: The checksum is _always_ the first field of these structs + */ +#define csum_vstruct(_c, _type, _nonce, _i) \ +({ \ + const void *start = ((const void *) (_i)) + sizeof((_i)->csum); \ + const void *end = vstruct_end(_i); \ + \ + bch2_checksum(_c, _type, _nonce, start, end - start); \ +}) + +int bch2_chacha_encrypt_key(struct bch_key *, struct nonce, void *, size_t); +int bch2_request_key(struct bch_sb *, struct bch_key *); + +void bch2_encrypt(struct bch_fs *, unsigned, struct nonce, + void *data, size_t); + +struct bch_csum bch2_checksum_bio(struct bch_fs *, unsigned, + struct nonce, struct bio *); + +int bch2_rechecksum_bio(struct bch_fs *, struct bio *, struct bversion, + struct bch_extent_crc_unpacked, + struct bch_extent_crc_unpacked *, + struct bch_extent_crc_unpacked *, + unsigned, unsigned, unsigned); + +void bch2_encrypt_bio(struct bch_fs *, unsigned, + struct nonce, struct bio *); + +int bch2_decrypt_sb_key(struct bch_fs *, struct bch_sb_field_crypt *, + struct bch_key *); + +int bch2_disable_encryption(struct bch_fs *); +int bch2_enable_encryption(struct bch_fs *, bool); + +void bch2_fs_encryption_exit(struct bch_fs *); +int bch2_fs_encryption_init(struct bch_fs *); + +static inline enum bch_csum_type bch2_csum_opt_to_type(enum bch_csum_opts type, + bool data) +{ + switch (type) { + case BCH_CSUM_OPT_NONE: + return BCH_CSUM_NONE; + case BCH_CSUM_OPT_CRC32C: + return data ? BCH_CSUM_CRC32C : BCH_CSUM_CRC32C_NONZERO; + case BCH_CSUM_OPT_CRC64: + return data ? BCH_CSUM_CRC64 : BCH_CSUM_CRC64_NONZERO; + default: + BUG(); + } +} + +static inline enum bch_csum_type bch2_data_checksum_type(struct bch_fs *c, + unsigned opt) +{ + if (c->sb.encryption_type) + return c->opts.wide_macs + ? BCH_CSUM_CHACHA20_POLY1305_128 + : BCH_CSUM_CHACHA20_POLY1305_80; + + return bch2_csum_opt_to_type(opt, true); +} + +static inline enum bch_csum_type bch2_meta_checksum_type(struct bch_fs *c) +{ + if (c->sb.encryption_type) + return BCH_CSUM_CHACHA20_POLY1305_128; + + return bch2_csum_opt_to_type(c->opts.metadata_checksum, false); +} + +static const unsigned bch2_compression_opt_to_type[] = { +#define x(t) [BCH_COMPRESSION_OPT_##t] = BCH_COMPRESSION_##t, + BCH_COMPRESSION_TYPES() +#undef x +}; + +static inline bool bch2_checksum_type_valid(const struct bch_fs *c, + unsigned type) +{ + if (type >= BCH_CSUM_NR) + return false; + + if (bch2_csum_type_is_encryption(type) && !c->chacha20) + return false; + + return true; +} + +/* returns true if not equal */ +static inline bool bch2_crc_cmp(struct bch_csum l, struct bch_csum r) +{ + /* + * XXX: need some way of preventing the compiler from optimizing this + * into a form that isn't constant time.. + */ + return ((l.lo ^ r.lo) | (l.hi ^ r.hi)) != 0; +} + +/* for skipping ahead and encrypting/decrypting at an offset: */ +static inline struct nonce nonce_add(struct nonce nonce, unsigned offset) +{ + EBUG_ON(offset & (CHACHA_BLOCK_SIZE - 1)); + + le32_add_cpu(&nonce.d[0], offset / CHACHA_BLOCK_SIZE); + return nonce; +} + +static inline struct nonce null_nonce(void) +{ + struct nonce ret; + + memset(&ret, 0, sizeof(ret)); + return ret; +} + +static inline struct nonce extent_nonce(struct bversion version, + struct bch_extent_crc_unpacked crc) +{ + unsigned size = crc.compression_type ? crc.uncompressed_size : 0; + struct nonce nonce = (struct nonce) {{ + [0] = cpu_to_le32(size << 22), + [1] = cpu_to_le32(version.lo), + [2] = cpu_to_le32(version.lo >> 32), + [3] = cpu_to_le32(version.hi| + (crc.compression_type << 24))^BCH_NONCE_EXTENT, + }}; + + return nonce_add(nonce, crc.nonce << 9); +} + +static inline bool bch2_key_is_encrypted(struct bch_encrypted_key *key) +{ + return le64_to_cpu(key->magic) != BCH_KEY_MAGIC; +} + +static inline struct nonce __bch2_sb_key_nonce(struct bch_sb *sb) +{ + __le64 magic = __bch2_sb_magic(sb); + + return (struct nonce) {{ + [0] = 0, + [1] = 0, + [2] = ((__le32 *) &magic)[0], + [3] = ((__le32 *) &magic)[1], + }}; +} + +static inline struct nonce bch2_sb_key_nonce(struct bch_fs *c) +{ + __le64 magic = bch2_sb_magic(c); + + return (struct nonce) {{ + [0] = 0, + [1] = 0, + [2] = ((__le32 *) &magic)[0], + [3] = ((__le32 *) &magic)[1], + }}; +} + +#endif /* _BCACHEFS_CHECKSUM_H */ |