dedup

commit 9155c685452c0b123472016b01acda1d2fedd1eb
parent 51368350b7b7c7a23fdc51cc86906c81572f9179
Author: sin <sin@2f30.org>
Date:   Tue, 21 May 2019 14:40:58 +0300

Remove some magic numbers

Diffstat:
M
bencrypt.c
 | 
17
+++++++++++------
M
bstorage.c
 | 
8
++++++--
M
snap.c
 | 
23
++++++++++++++---------
M
state.c
 | 
15
++++++++++-----

4 files changed, 41 insertions(+), 22 deletions(-)
diff --git a/bencrypt.c b/bencrypt.c
@@ -22,7 +22,8 @@ extern struct param param;
 
 #define EDNONETYPE	0x300
 #define EDCHACHATYPE	0x301
-#define EDSIZE		(8 + 8 + 24)
+#define NONCESIZE	crypto_aead_xchacha20poly1305_ietf_NPUBBYTES
+#define EDSIZE		(8 + 8 + NONCESIZE)
 
 extern int pack(unsigned char *, char *, ...);
 extern int unpack(unsigned char *, char *, ...);
@@ -54,19 +55,21 @@ struct ectx {
 
 /* Encryption descriptor */
 struct ed {
-	uint16_t type;		/* encryption algorithm type */
+	uint16_t type;			/* encryption algorithm type */
 	unsigned char reserved[6];	/* should be set to 0 when writing */
-	uint64_t size;		/* size of encrypted block */
-	unsigned char nonce[crypto_aead_xchacha20poly1305_ietf_NPUBBYTES];
+	uint64_t size;			/* size of encrypted block */
+	unsigned char nonce[NONCESIZE];	/* unpredictable nonce used when encrypting */
 };
 
 /* Unpack encryption descriptor */
 static int
 unpacked(unsigned char *buf, struct ed *ed)
 {
+	char fmt[BUFSIZ];
 	int n;
 
-	n = unpack(buf, "s'6q'24",
+	snprintf(fmt, sizeof(fmt), "s'6q'%d", NONCESIZE);
+	n = unpack(buf, fmt,
 	           &ed->type,
 	           ed->reserved,
 	           &ed->size,
@@ -80,9 +83,11 @@ unpacked(unsigned char *buf, struct ed *ed)
 static int
 packed(unsigned char *buf, struct ed *ed)
 {
+	char fmt[BUFSIZ];
 	int n;
 
-	n = pack(buf, "s'6q'24",
+	snprintf(fmt, sizeof(fmt), "s'6q'%d", NONCESIZE);
+	n = pack(buf, fmt,
 	         ed->type,
 	         ed->reserved,
 	         ed->size,
diff --git a/bstorage.c b/bstorage.c
@@ -117,9 +117,11 @@ static RB_GENERATE(bdcache, bd, rbe, bd_cmp)
 static int
 unpackbhdr(unsigned char *buf, struct bhdr *bhdr)
 {
+	char fmt[BUFSIZ];
 	int n;
 
-	n = unpack(buf, "'16qq",
+	snprintf(fmt, sizeof(fmt), "'%dqq", NBHDRMAGIC);
+	n = unpack(buf, fmt,
 	           bhdr->magic,
 	           &bhdr->flags,
 	           &bhdr->nbd);
@@ -132,9 +134,11 @@ unpackbhdr(unsigned char *buf, struct bhdr *bhdr)
 static int
 packbhdr(unsigned char *buf, struct bhdr *bhdr)
 {
+	char fmt[BUFSIZ];
 	int n;
 
-	n = pack(buf, "'16qq",
+	snprintf(fmt, sizeof(fmt), "'%dqq", NBHDRMAGIC);
+	n = pack(buf, fmt,
 	         bhdr->magic,
 	         bhdr->flags,
 	         bhdr->nbd);
diff --git a/snap.c b/snap.c
@@ -35,7 +35,8 @@
 #define VMAJSHIFT	8
 #define VMAJMASK	0xff
 
-#define SHDRSIZE	(NSHDRMAGIC + 24 + 8 + 8)
+#define CRYPTOHDRSIZE	crypto_secretstream_xchacha20poly1305_HEADERBYTES	
+#define SHDRSIZE	(NSHDRMAGIC + CRYPTOHDRSIZE + 8 + 8)
 
 extern struct param param;
 
@@ -45,15 +46,15 @@ extern int unpack(unsigned char *, char *, ...);
 
 /* Snapshot header structure */
 struct shdr {
-	char magic[NSHDRMAGIC];		/* magic number for file(1) */
-	unsigned char header[crypto_secretstream_xchacha20poly1305_HEADERBYTES];
-	uint64_t flags;			/* version number */
-	uint64_t nbd;			/* number of block hashes */
+	char magic[NSHDRMAGIC];			/* magic number for file(1) */
+	unsigned char header[CRYPTOHDRSIZE];	/* xchacha20-poly1305 crypto header size */
+	uint64_t flags;				/* version number */
+	uint64_t nbd;				/* number of block hashes */
 };
 
 struct mdnode {
-	unsigned char md[MDSIZE];	/* hash of block */
-	TAILQ_ENTRY(mdnode) e;		/* mdhead link node */
+	unsigned char md[MDSIZE];		/* hash of block */
+	TAILQ_ENTRY(mdnode) e;			/* mdhead link node */
 };
 
 struct sctx {
@@ -69,9 +70,11 @@ struct sctx {
 static int
 unpackshdr(unsigned char *buf, struct shdr *shdr)
 {
+	char fmt[BUFSIZ];
 	int n;
 
-	n = unpack(buf, "'16'24qq",
+	snprintf(fmt, sizeof(fmt), "'%d'%dqq", NSHDRMAGIC, CRYPTOHDRSIZE);
+	n = unpack(buf, fmt,
 	           shdr->magic,
 	           shdr->header,
 	           &shdr->flags,
@@ -85,9 +88,11 @@ unpackshdr(unsigned char *buf, struct shdr *shdr)
 static int
 packshdr(unsigned char *buf, struct shdr *shdr)
 {
+	char fmt[BUFSIZ];
 	int n;
 
-	n = pack(buf, "'16'24qq",
+	snprintf(fmt, sizeof(fmt), "'%d'%dqq", NSHDRMAGIC, CRYPTOHDRSIZE);
+	n = pack(buf, fmt,
 	         shdr->magic,
 	         shdr->header,
 	         shdr->flags,
diff --git a/state.c b/state.c
@@ -29,9 +29,10 @@
 #define ENONETYPE       0
 #define ECHACHATYPE     1
 
+#define NONCESIZE	crypto_aead_xchacha20poly1305_ietf_NPUBBYTES
 #define MSEEDSIZE	4
-#define CSEEDSIZE	(MSEEDSIZE + 16)
-#define SHDRSIZE	(8 + 24 + CSEEDSIZE)
+#define CSEEDSIZE	(MSEEDSIZE + crypto_aead_xchacha20poly1305_ietf_ABYTES)
+#define SHDRSIZE	(8 + NONCESIZE + CSEEDSIZE)
 
 /* misc helpers */
 extern int pack(unsigned char *, char *, ...);
@@ -39,7 +40,7 @@ extern int unpack(unsigned char *, char *, ...);
 
 struct shdr {
 	uint64_t flags;
-	unsigned char nonce[crypto_aead_xchacha20poly1305_ietf_NPUBBYTES];
+	unsigned char nonce[NONCESIZE];
 	unsigned char seed[CSEEDSIZE];
 };
 
@@ -47,9 +48,11 @@ struct shdr {
 static int
 unpackshdr(unsigned char *buf, struct shdr *shdr)
 {
+	char fmt[BUFSIZ];
 	int n;
 
-	n = unpack(buf, "q'24'20",
+	snprintf(fmt, sizeof(fmt), "q'%d'%d", NONCESIZE, CSEEDSIZE);
+	n = unpack(buf, fmt,
 	           &shdr->flags,
 	           shdr->nonce,
 	           shdr->seed);
@@ -61,9 +64,11 @@ unpackshdr(unsigned char *buf, struct shdr *shdr)
 static int
 packshdr(unsigned char *buf, struct shdr *shdr)
 {
+	char fmt[BUFSIZ];
 	int n;
 
-	n = pack(buf, "q'24'20",
+	snprintf(fmt, sizeof(fmt), "q'%d'%d", NONCESIZE, CSEEDSIZE);
+	n = pack(buf, fmt,
 	         shdr->flags,
 	         shdr->nonce,
 	         shdr->seed);