From df056e5973887181d83b1ca568dde7308a7f1355 Mon Sep 17 00:00:00 2001
From: Christian Decker <decker.christian@gmail.com>
Date: Tue, 4 Jul 2017 18:51:39 +0200
Subject: [PATCH] bitcoin: Added chainparams grouping blockchain specific
 parameters

---
 Makefile              |  4 ++-
 bitcoin/chainparams.c | 73 +++++++++++++++++++++++++++++++++++++++++++
 bitcoin/chainparams.h | 34 ++++++++++++++++++++
 3 files changed, 110 insertions(+), 1 deletion(-)
 create mode 100644 bitcoin/chainparams.c
 create mode 100644 bitcoin/chainparams.h

diff --git a/Makefile b/Makefile
index 34f75ae87..a66553d87 100644
--- a/Makefile
+++ b/Makefile
@@ -32,7 +32,8 @@ TEST_PROGRAMS :=				\
 
 BITCOIN_SRC :=					\
 	bitcoin/base58.c			\
-	bitcoin/block.c			\
+	bitcoin/block.c				\
+	bitcoin/chainparams.c			\
 	bitcoin/locktime.c			\
 	bitcoin/pubkey.c			\
 	bitcoin/pullpush.c			\
@@ -168,6 +169,7 @@ CCAN_HEADERS :=						\
 BITCOIN_HEADERS := bitcoin/address.h		\
 	bitcoin/base58.h			\
 	bitcoin/block.h				\
+	bitcoin/chainparams.h			\
 	bitcoin/locktime.h			\
 	bitcoin/preimage.h			\
 	bitcoin/privkey.h			\
diff --git a/bitcoin/chainparams.c b/bitcoin/chainparams.c
new file mode 100644
index 000000000..c0b58c07b
--- /dev/null
+++ b/bitcoin/chainparams.c
@@ -0,0 +1,73 @@
+#include "chainparams.h"
+#include <string.h>
+
+#define CHAINPARAMS_NETWORK_COUNT 4
+
+const struct chainparams networks[CHAINPARAMS_NETWORK_COUNT] = {
+    {.index = 0,
+     .network_name = "bitcoin",
+     .genesis_blockhash = {{.u.u8 = {0x00, 0x00, 0x00, 0x00, 0x00, 0x19, 0xd6,
+				     0x68, 0x9c, 0x08, 0x5a, 0xe1, 0x65, 0x83,
+				     0x1e, 0x93, 0x4f, 0xf7, 0x63, 0xae, 0x46,
+				     0xa2, 0xa6, 0xc1, 0x72, 0xb3, 0xf1, 0xb6,
+				     0x0a, 0x8c, 0xe2, 0x6f}}},
+     .rpc_port = 8332,
+     .cli = "bitcoin-cli",
+     .cli_args = "",
+     .dust_limit = 546,
+     .testnet = false},
+    {.index = 1,
+     .network_name = "regtest",
+     .genesis_blockhash = {{.u.u8 = {0x0f, 0x91, 0x88, 0xf1, 0x3c, 0xb7, 0xb2,
+				     0xc7, 0x1f, 0x2a, 0x33, 0x5e, 0x3a, 0x4f,
+				     0xc3, 0x28, 0xbf, 0x5b, 0xeb, 0x43, 0x60,
+				     0x12, 0xaf, 0xca, 0x59, 0x0b, 0x1a, 0x11,
+				     0x46, 0x6e, 0x22, 0x06}}},
+     .rpc_port = 18332,
+     .cli = "bitcoin-cli",
+     .cli_args = "-regtest",
+     .dust_limit = 546,
+     .testnet = true},
+    {.index = 2,
+     .network_name = "testnet",
+     .genesis_blockhash = {{.u.u8 = {0x00, 0x00, 0x00, 0x00, 0x09, 0x33, 0xea,
+				     0x01, 0xad, 0x0e, 0xe9, 0x84, 0x20, 0x97,
+				     0x79, 0xba, 0xae, 0xc3, 0xce, 0xd9, 0x0f,
+				     0xa3, 0xf4, 0x08, 0x71, 0x95, 0x26, 0xf8,
+				     0xd7, 0x7f, 0x49, 0x43}}},
+     .rpc_port = 18332,
+     .cli = "bitcoin-cli",
+     .cli_args = "-testnet",
+     .dust_limit = 546,
+     .testnet = true},
+    {.index = 3,
+     .network_name = "litecoin",
+     .genesis_blockhash = {{.u.u8 = {0x12, 0xa7, 0x65, 0xe3, 0x1f, 0xfd, 0x40,
+				     0x59, 0xba, 0xda, 0x1e, 0x25, 0x19, 0x0f,
+				     0x6e, 0x98, 0xc9, 0x9d, 0x97, 0x14, 0xd3,
+				     0x34, 0xef, 0xa4, 0x1a, 0x19, 0x5a, 0x7e,
+				     0x7e, 0x04, 0xbf, 0xe2}}},
+     .rpc_port = 18332,
+     .cli = "litecoin-cli",
+     .cli_args = "",
+     .dust_limit = 100000,
+     .testnet = false}};
+
+const struct chainparams *chainparams_for_network(const char *network_name)
+{
+	for (int i = 0; i < CHAINPARAMS_NETWORK_COUNT; i++) {
+		if (strcmp(network_name, networks[i].network_name) == 0) {
+			return &networks[i];
+		}
+	}
+	return NULL;
+}
+
+const struct chainparams *chainparams_by_index(const int index)
+{
+	if (index >= CHAINPARAMS_NETWORK_COUNT || index < 0) {
+		return NULL;
+	} else {
+		return &networks[index];
+	}
+}
diff --git a/bitcoin/chainparams.h b/bitcoin/chainparams.h
new file mode 100644
index 000000000..5709cc1e2
--- /dev/null
+++ b/bitcoin/chainparams.h
@@ -0,0 +1,34 @@
+#ifndef LIGHTNING_BITCOIN_CHAINPARAMS_H
+#define LIGHTNING_BITCOIN_CHAINPARAMS_H
+
+#include "config.h"
+#include <bitcoin/shadouble.h>
+#include <ccan/short_types/short_types.h>
+#include <stdbool.h>
+
+struct chainparams {
+	const int index;
+	const char *network_name;
+	const struct sha256_double genesis_blockhash;
+	const int rpc_port;
+	char *cli;
+	char *cli_args;
+	const u64 dust_limit;
+
+	/* Whether this is a test network or not */
+	const bool testnet;
+};
+
+/**
+ * chainparams_for_network - Look up blockchain parameters by its name
+ */
+const struct chainparams *chainparams_for_network(const char *network_name);
+
+/**
+ * chainparams_by_index - Helper to get a network by its numeric index
+ *
+ * We may not want to pass the network name through to subdaemons, so
+ * we allows lookup by index.
+ */
+const struct chainparams *chainparams_by_index(const int index);
+#endif /* LIGHTNING_BITCOIN_CHAINPARAMS_H */