1 files changed, 133 insertions, 0 deletions
diff --git a/libbcachefs/checksum.h b/libbcachefs/checksum.h
new file mode 100644
index 00000000..f540e305
--- /dev/null
+++ b/libbcachefs/checksum.h
@@ -0,0 +1,133 @@
+#ifndef _BCACHE_CHECKSUM_H
+#define _BCACHE_CHECKSUM_H
+
+#include "bcachefs.h"
+#include "super-io.h"
+
+#include <crypto/chacha20.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 *);
+void bch2_encrypt_bio(struct bch_fs *, unsigned,
+		    struct nonce, struct bio *);
+
+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 unsigned bch2_data_checksum_type(struct bch_fs *c)
+{
+	if (c->sb.encryption_type)
+		return c->opts.wide_macs
+			? BCH_CSUM_CHACHA20_POLY1305_128
+			: BCH_CSUM_CHACHA20_POLY1305_80;
+
+	return c->opts.data_checksum;
+}
+
+static inline unsigned bch2_meta_checksum_type(struct bch_fs *c)
+{
+	return c->sb.encryption_type
+		? BCH_CSUM_CHACHA20_POLY1305_128
+		: c->opts.metadata_checksum;
+}
+
+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;
+}
+
+static const unsigned bch_crc_bytes[] = {
+	[BCH_CSUM_NONE]				= 0,
+	[BCH_CSUM_CRC32C]			= 4,
+	[BCH_CSUM_CRC64]			= 8,
+	[BCH_CSUM_CHACHA20_POLY1305_80]		= 10,
+	[BCH_CSUM_CHACHA20_POLY1305_128]	= 16,
+};
+
+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 & (CHACHA20_BLOCK_SIZE - 1));
+
+	le32_add_cpu(&nonce.d[0], offset / CHACHA20_BLOCK_SIZE);
+	return nonce;
+}
+
+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 /* _BCACHE_CHECKSUM_H */