bigsize: make it a proper first-class type.

It doesn't belong in bitcoin, and should not be confused with varint_t.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

bitcoin/varint.c

@@ -60,65 +60,3 @@ size_t varint_get(const u8 *p, size_t max, varint_t *val)
 		return 1;
 	}
 }
-
-size_t bigsize_put(u8 buf[VARINT_MAX_LEN], varint_t v)
-{
-	u8 *p = buf;
-
-	if (v < 0xfd) {
-		*(p++) = v;
-	} else if (v <= 0xffff) {
-		(*p++) = 0xfd;
-		(*p++) = v >> 8;
-		(*p++) = v;
-	} else if (v <= 0xffffffff) {
-		(*p++) = 0xfe;
-		(*p++) = v >> 24;
-		(*p++) = v >> 16;
-		(*p++) = v >> 8;
-		(*p++) = v;
-	} else {
-		(*p++) = 0xff;
-		(*p++) = v >> 56;
-		(*p++) = v >> 48;
-		(*p++) = v >> 40;
-		(*p++) = v >> 32;
-		(*p++) = v >> 24;
-		(*p++) = v >> 16;
-		(*p++) = v >> 8;
-		(*p++) = v;
-	}
-	return p - buf;
-}
-
-size_t bigsize_get(const u8 *p, size_t max, varint_t *val)
-{
-	if (max < 1)
-		return 0;
-
-	switch (*p) {
-	case 0xfd:
-		if (max < 3)
-			return 0;
-		*val = ((u64)p[1] << 8) + p[2];
-		return 3;
-	case 0xfe:
-		if (max < 5)
-			return 0;
-		*val = ((u64)p[1] << 24) + ((u64)p[2] << 16)
-			+ ((u64)p[3] << 8) + p[4];
-		return 5;
-	case 0xff:
-		if (max < 9)
-			return 0;
-		*val = ((u64)p[1] << 56) + ((u64)p[2] << 48)
-			+ ((u64)p[3] << 40) + ((u64)p[4] << 32)
-			+ ((u64)p[5] << 24) + ((u64)p[6] << 16)
-			+ ((u64)p[7] << 8) + p[8];
-		return 9;
-	default:
-		*val = *p;
-		return 1;
-	}
-
-}

bitcoin/varint.h

@@ -15,12 +15,4 @@ size_t varint_put(u8 buf[VARINT_MAX_LEN], varint_t v);
 /* Returns bytes used: 0 if max_len too small. */
 size_t varint_get(const u8 *p, size_t max_len, varint_t *val);
 
-
-/* Big-endian variant of varint_put, used in lightning */
-size_t bigsize_put(u8 buf[VARINT_MAX_LEN], varint_t v);
-
-/* Big-endian variant of varint_get, used in lightning */
-size_t bigsize_get(const u8 *p, size_t max, varint_t *val);
-
-
 #endif /* LIGHTNING_BITCOIN_VARINT_H */

channeld/Makefile

@@ -35,6 +35,7 @@ ALL_GEN_HEADERS += $(LIGHTNINGD_CHANNEL_HEADERS_GEN)
 CHANNELD_COMMON_OBJS :=				\
 	common/amount.o				\
 	common/base32.o				\
+	common/bigsize.o			\
 	common/bip32.o				\
 	common/channel_config.o			\
 	common/crypto_state.o			\

common/Makefile

@@ -4,6 +4,7 @@ COMMON_SRC_NOGEN :=				\
 	common/base32.c				\
 	common/bech32.c				\
 	common/bech32_util.c			\
+	common/bigsize.c			\
 	common/bip32.c				\
 	common/bolt11.c				\
 	common/channel_config.c			\

common/bigsize.c

@@ -0,0 +1,75 @@
+#include <common/bigsize.h>
+
+size_t bigsize_len(bigsize_t v)
+{
+	if (v < 0xfd) {
+		return 1;
+	} else if (v <= 0xffff) {
+		return 3;
+	} else if (v <= 0xffffffff) {
+		return 5;
+	} else {
+		return 9;
+	}
+}
+
+size_t bigsize_put(u8 buf[BIGSIZE_MAX_LEN], bigsize_t v)
+{
+	u8 *p = buf;
+
+	if (v < 0xfd) {
+		*(p++) = v;
+	} else if (v <= 0xffff) {
+		(*p++) = 0xfd;
+		(*p++) = v >> 8;
+		(*p++) = v;
+	} else if (v <= 0xffffffff) {
+		(*p++) = 0xfe;
+		(*p++) = v >> 24;
+		(*p++) = v >> 16;
+		(*p++) = v >> 8;
+		(*p++) = v;
+	} else {
+		(*p++) = 0xff;
+		(*p++) = v >> 56;
+		(*p++) = v >> 48;
+		(*p++) = v >> 40;
+		(*p++) = v >> 32;
+		(*p++) = v >> 24;
+		(*p++) = v >> 16;
+		(*p++) = v >> 8;
+		(*p++) = v;
+	}
+	return p - buf;
+}
+
+size_t bigsize_get(const u8 *p, size_t max, bigsize_t *val)
+{
+	if (max < 1)
+		return 0;
+
+	switch (*p) {
+	case 0xfd:
+		if (max < 3)
+			return 0;
+		*val = ((u64)p[1] << 8) + p[2];
+		return 3;
+	case 0xfe:
+		if (max < 5)
+			return 0;
+		*val = ((u64)p[1] << 24) + ((u64)p[2] << 16)
+			+ ((u64)p[3] << 8) + p[4];
+		return 5;
+	case 0xff:
+		if (max < 9)
+			return 0;
+		*val = ((u64)p[1] << 56) + ((u64)p[2] << 48)
+			+ ((u64)p[3] << 40) + ((u64)p[4] << 32)
+			+ ((u64)p[5] << 24) + ((u64)p[6] << 16)
+			+ ((u64)p[7] << 8) + p[8];
+		return 9;
+	default:
+		*val = *p;
+		return 1;
+	}
+}

common/bigsize.h

@@ -0,0 +1,21 @@
+#ifndef LIGHTNING_COMMON_BIGSIZE_H
+#define LIGHTNING_COMMON_BIGSIZE_H
+#include "config.h"
+#include <ccan/short_types/short_types.h>
+#include <stddef.h>
+
+/* typedef for clarity. */
+typedef u64 bigsize_t;
+
+#define BIGSIZE_MAX_LEN 9
+
+/* Returns length of buf used. */
+size_t bigsize_put(u8 buf[BIGSIZE_MAX_LEN], bigsize_t v);
+
+/* Returns 0 on failure, otherwise length (<= max) used.  */
+size_t bigsize_get(const u8 *p, size_t max, bigsize_t *val);
+
+/* How many bytes does it take to encode v? */
+size_t bigsize_len(bigsize_t v);
+
+#endif /* LIGHTNING_COMMON_BIGSIZE_H */

common/sphinx.c

@@ -1,7 +1,5 @@
 #include <assert.h>
 
-#include <bitcoin/varint.h>
-
 #include <ccan/array_size/array_size.h>
 #include <ccan/crypto/ripemd160/ripemd160.h>
 #include <ccan/crypto/sha256/sha256.h>
@@ -96,7 +94,7 @@ static size_t sphinx_hop_size(const struct sphinx_hop *hop)
 
 	/* There is no point really in trying to serialize something that is
 	 * larger than the maximum length we can fit into the payload region
-	 * anyway. 3 here is the maximum varint size that we allow. */
+	 * anyway. 3 here is the maximum bigsize size that we allow. */
 	assert(size < ROUTING_INFO_SIZE - 3 - HMAC_SIZE);
 
 	/* Backwards compatibility: realm 0 is the legacy hop_data format and
@@ -112,7 +110,7 @@ static size_t sphinx_hop_size(const struct sphinx_hop *hop)
 	else
 		vsize = 3;
 
-	/* The hop must accomodate the hop_payload, as well as the varint
+	/* The hop must accomodate the hop_payload, as well as the bigsize
 	 * describing the length and HMAC. */
 	return vsize + size + HMAC_SIZE;
 }
@@ -471,7 +469,7 @@ static bool sphinx_write_frame(u8 *dest, const struct sphinx_hop *hop)
 static void sphinx_parse_payload(struct route_step *step, const u8 *src)
 {
 	size_t hop_size, vsize;
-	varint_t raw_size;
+	bigsize_t raw_size;
 #if !EXPERIMENTAL_FEATURES
 	if (src[0] != 0x00) {
 		step->type = SPHINX_INVALID_PAYLOAD;
@@ -588,7 +586,7 @@ struct route_step *process_onionpacket(
 	u8 stream[NUM_STREAM_BYTES];
 	u8 paddedheader[2*ROUTING_INFO_SIZE];
 	size_t vsize;
-	varint_t shift_size;
+	bigsize_t shift_size;
 
 	step->next = talz(step, struct onionpacket);
 	step->next->version = msg->version;

common/test/run-sphinx.c

@@ -12,6 +12,12 @@
 #include <unistd.h>
 
 /* AUTOGENERATED MOCKS START */
+/* Generated stub for bigsize_get */
+size_t bigsize_get(const u8 *p UNNEEDED, size_t max UNNEEDED, bigsize_t *val UNNEEDED)
+{ fprintf(stderr, "bigsize_get called!\n"); abort(); }
+/* Generated stub for bigsize_put */
+size_t bigsize_put(u8 buf[BIGSIZE_MAX_LEN] UNNEEDED, bigsize_t v UNNEEDED)
+{ fprintf(stderr, "bigsize_put called!\n"); abort(); }
 /* Generated stub for fromwire */
 const u8 *fromwire(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, void *copy UNNEEDED, size_t n UNNEEDED)
 { fprintf(stderr, "fromwire called!\n"); abort(); }
@@ -21,9 +27,6 @@ struct amount_msat fromwire_amount_msat(const u8 **cursor UNNEEDED, size_t *max
 /* Generated stub for fromwire_fail */
 const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
-/* Generated stub for fromwire_pad */
-void fromwire_pad(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, size_t num UNNEEDED)
-{ fprintf(stderr, "fromwire_pad called!\n"); abort(); }
 /* Generated stub for fromwire_short_channel_id */
 void fromwire_short_channel_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
 			       struct short_channel_id *short_channel_id UNNEEDED)
@@ -40,9 +43,6 @@ u8 fromwire_u8(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 /* Generated stub for towire */
 void towire(u8 **pptr UNNEEDED, const void *data UNNEEDED, size_t len UNNEEDED)
 { fprintf(stderr, "towire called!\n"); abort(); }
-/* Generated stub for towire_amount_msat */
-void towire_amount_msat(u8 **pptr UNNEEDED, const struct amount_msat msat UNNEEDED)
-{ fprintf(stderr, "towire_amount_msat called!\n"); abort(); }
 /* Generated stub for towire_pad */
 void towire_pad(u8 **pptr UNNEEDED, size_t num UNNEEDED)
 { fprintf(stderr, "towire_pad called!\n"); abort(); }
@@ -59,9 +59,6 @@ void towire_u32(u8 **pptr UNNEEDED, u32 v UNNEEDED)
 /* Generated stub for towire_u64 */
 void towire_u64(u8 **pptr UNNEEDED, u64 v UNNEEDED)
 { fprintf(stderr, "towire_u64 called!\n"); abort(); }
-/* Generated stub for towire_u8 */
-void towire_u8(u8 **pptr UNNEEDED, u8 v UNNEEDED)
-{ fprintf(stderr, "towire_u8 called!\n"); abort(); }
 /* AUTOGENERATED MOCKS END */
 
 secp256k1_context *secp256k1_ctx;

devtools/Makefile

@@ -11,6 +11,7 @@ DEVTOOLS_COMMON_OBJS :=				\
 	common/base32.o				\
 	common/bech32.o				\
 	common/bech32_util.o			\
+	common/bigsize.o			\
 	common/bolt11.o				\
 	common/crypto_state.o			\
 	common/decode_short_channel_ids.o	\

lightningd/Makefile

@@ -19,6 +19,7 @@ LIGHTNINGD_COMMON_OBJS :=			\
 	common/base32.o				\
 	common/bech32.o				\
 	common/bech32_util.o			\
+	common/bigsize.o			\
 	common/bip32.o				\
 	common/bolt11.o				\
 	common/channel_config.o			\

wire/wire.h

@@ -12,6 +12,7 @@
 #include <ccan/short_types/short_types.h>
 #include <ccan/structeq/structeq.h>
 #include <common/amount.h>
+#include <common/bigsize.h>
 #include <secp256k1_recovery.h>
 #include <stdlib.h>
 
@@ -31,7 +32,7 @@ struct siphash_seed;
 
 /* Makes generate-wire.py work */
 typedef char wirestring;
-typedef u64 bigsize;
+typedef bigsize_t bigsize;
 
 /* FIXME: Some versions of spec using 'varint' for bigsize' */
 typedef bigsize varint;