daemon/bitcoind: communication with bitcoind.

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

daemon/Makefile

@@ -14,6 +14,7 @@ DAEMON_LIB_SRC :=				\
 DAEMON_LIB_OBJS := $(DAEMON_LIB_SRC:.c=.o)
 
 DAEMON_SRC :=					\
+	daemon/bitcoind.c			\
 	daemon/cryptopkt.c			\
 	daemon/dns.c				\
 	daemon/jsonrpc.c			\
@@ -31,6 +32,7 @@ DAEMON_JSMN_OBJS := daemon/jsmn.o
 DAEMON_JSMN_HEADERS := daemon/jsmn/jsmn.h
 
 DAEMON_HEADERS :=				\
+	daemon/bitcoind.h			\
 	daemon/configdir.h			\
 	daemon/cryptopkt.h			\
 	daemon/dns.h				\

daemon/bitcoind.c

@@ -0,0 +1,231 @@
+/* Code for talking to bitcoind.  We use bitcoin-cli. */
+#include "bitcoin/base58.h"
+#include "bitcoin/shadouble.h"
+#include "bitcoin/tx.h"
+#include "bitcoind.h"
+#include "json.h"
+#include "lightningd.h"
+#include "log.h"
+#include <ccan/cast/cast.h>
+#include <ccan/io/io.h>
+#include <ccan/pipecmd/pipecmd.h>
+#include <ccan/str/hex/hex.h>
+#include <ccan/tal/str/str.h>
+#include <ccan/tal/tal.h>
+#include <errno.h>
+
+#define BITCOIN_CLI "bitcoin-cli"
+
+static char **gather_args(const tal_t *ctx, const char *cmd, va_list ap)
+{
+	size_t n = 2;
+	char **args = tal_arr(ctx, char *, n+1);
+
+	args[0] = BITCOIN_CLI;
+	args[1] = cast_const(char *, cmd);
+
+	while ((args[n] = va_arg(ap, char *)) != NULL) {
+		args[n] = tal_strdup(args, args[n]);
+		n++;
+		tal_resize(&args, n + 1);
+	}
+	return args;
+}
+
+struct bitcoin_cli {
+	struct lightningd_state *state;
+	int fd;
+	pid_t pid;
+	char **args;
+	char *output;
+	size_t output_bytes;
+	size_t new_output;
+	void (*process)(struct bitcoin_cli *);
+	void *cb;
+	void *cb_arg;
+};
+
+static struct io_plan *read_more(struct io_conn *conn, struct bitcoin_cli *bcli)
+{
+	bcli->output_bytes += bcli->new_output;
+	if (bcli->output_bytes == tal_count(bcli->output))
+		tal_resize(&bcli->output, bcli->output_bytes * 2);
+	return io_read_partial(conn, bcli->output + bcli->output_bytes,
+			       tal_count(bcli->output) - bcli->output_bytes,
+			       &bcli->new_output, read_more, bcli);
+}
+
+static struct io_plan *output_init(struct io_conn *conn, struct bitcoin_cli *bcli)
+{
+	bcli->output_bytes = bcli->new_output = 0;
+	bcli->output = tal_arr(bcli, char, 100);
+	return read_more(conn, bcli);
+}
+
+static void bcli_finished(struct io_conn *conn, struct bitcoin_cli *bcli)
+{
+	int ret, status;
+
+	/* FIXME: If we waited for SIGCHILD, this could never hang! */
+	ret = waitpid(bcli->pid, &status, 0);
+	if (ret != bcli->pid)
+		fatal("bitcoind: '%s' '%s' %s",
+		      bcli->args[0], bcli->args[1],
+		      ret == 0 ? "not exited?" : strerror(errno));
+
+	if (!WIFEXITED(status))
+		fatal("bitcoind: '%s' '%s' died with signal %i",
+		      bcli->args[0], bcli->args[1],
+		      WTERMSIG(status));
+
+	if (WEXITSTATUS(status) != 0)
+		fatal("bitcoind: '%s' '%s' failed (%i '%.*s')",
+		      bcli->args[0], bcli->args[1], WEXITSTATUS(status),
+		      (int)bcli->output_bytes, bcli->output);
+
+	assert(bcli->state->bitcoind_in_progress);
+	bcli->state->bitcoind_in_progress--;
+	bcli->process(bcli);
+}
+
+static void
+start_bitcoin_cli(struct lightningd_state *state,
+		  void (*process)(struct bitcoin_cli *),
+		  void *cb, void *cb_arg,
+		  char *cmd, ...)
+{
+	va_list ap;
+	struct bitcoin_cli *bcli = tal(state, struct bitcoin_cli);
+	struct io_conn *conn;
+
+	bcli->state = state;
+	bcli->process = process;
+	bcli->cb = cb;
+	bcli->cb_arg = cb_arg;
+	va_start(ap, cmd);
+	bcli->args = gather_args(bcli, cmd, ap);
+	va_end(ap);
+
+	bcli->pid = pipecmdarr(&bcli->fd, NULL, &bcli->fd, bcli->args);
+	if (bcli->pid < 0)
+		fatal("%s exec failed: %s", bcli->args[0], strerror(errno));
+
+	conn = io_new_conn(state, bcli->fd, output_init, bcli);
+	tal_steal(conn, bcli);
+	state->bitcoind_in_progress++;
+	io_set_finish(conn, bcli_finished, bcli);
+}
+
+static void process_importaddress(struct bitcoin_cli *bcli)
+{
+	if (bcli->output_bytes != 0)
+		fatal("bitcoind: '%s' '%s' unexpeced output '%.*s'",
+		      bcli->args[0], bcli->args[1],
+		      (int)bcli->output_bytes, bcli->output);
+}
+
+void bitcoind_watch_addr(struct lightningd_state *state,
+			 const struct ripemd160 *redeemhash)
+{
+	char *p2shaddr = p2sh_to_base58(state, state->config.testnet,
+					redeemhash);
+
+	start_bitcoin_cli(state, process_importaddress, NULL, NULL,
+			  "importaddress", p2shaddr, "", "false", NULL);
+	tal_free(p2shaddr);
+}
+
+static void process_transactions(struct bitcoin_cli *bcli)
+{
+	const jsmntok_t *tokens, *t, *end;
+	bool valid;
+	void (*cb)(struct lightningd_state *state,
+		   const struct sha256_double *txid,
+		   int confirmations) = bcli->cb;
+
+	tokens = json_parse_input(bcli->output, bcli->output_bytes, &valid);
+	if (!tokens)
+		fatal("bitcoind: '%s' '%s' %s response",
+		      bcli->args[0], bcli->args[1],
+		      valid ? "partial" : "invalid");
+
+	if (tokens[0].type != JSMN_ARRAY)
+		fatal("listtransactions: '%s' '%s' gave non-array (%.*s)?",
+		      bcli->args[0], bcli->args[1],
+		      (int)bcli->output_bytes, bcli->output);
+
+	end = json_next(tokens);
+	for (t = tokens + 1; t < end; t = json_next(t)) {
+		struct sha256_double txid;
+		const jsmntok_t *txidtok, *conftok;
+		long int conf;
+		char *end;
+
+		txidtok = json_get_member(bcli->output, t, "txid");
+		conftok = json_get_member(bcli->output, t, "confirmations");
+		if (!txidtok || !conftok)
+			fatal("listtransactions: no %s field!",
+			      txidtok ? "confirmations" : "txid");
+		if (!bitcoin_txid_from_hex(bcli->output + txidtok->start,
+					   txidtok->end - txidtok->start,
+					   &txid)) {
+			fatal("listtransactions: bad txid '%.*s'",
+			      (int)(txidtok->end - txidtok->start),
+			      bcli->output + txidtok->start);
+		}
+		conf = strtol(bcli->output + conftok->start, &end, 10);
+		if (end != bcli->output + conftok->end)
+			fatal("listtransactions: bad confirmations '%.*s'",
+			      (int)(conftok->end - conftok->start),
+			      bcli->output + conftok->start);
+
+		/* FIXME: log txid */
+		log_debug(bcli->state->base_log,
+			  "txid %02x%02x%02x%02x..., conf %li",
+			  txid.sha.u.u8[0], txid.sha.u.u8[1],
+			  txid.sha.u.u8[2], txid.sha.u.u8[3],
+			  conf);
+
+		cb(bcli->state, &txid, conf);
+	}
+}
+
+void bitcoind_poll_transactions(struct lightningd_state *state,
+				void (*cb)(struct lightningd_state *state,
+					   const struct sha256_double *txid,
+					   int confirmations))
+{
+	/* FIXME: Iterate and detect duplicates. */
+	start_bitcoin_cli(state, process_transactions, cb, NULL,
+			  "listtransactions", "*", "100000", "0", "true",
+			  NULL);
+}
+
+static void process_rawtx(struct bitcoin_cli *bcli)
+{
+	struct bitcoin_tx *tx;
+	void (*cb)(struct lightningd_state *state,
+		   const struct bitcoin_tx *tx, void *arg) = bcli->cb;
+
+	tx = bitcoin_tx_from_hex(bcli, bcli->output, bcli->output_bytes);
+	if (!tx)
+		fatal("Unknown txid (output %.*s)",
+		      (int)bcli->output_bytes, (char *)bcli->output);
+	cb(bcli->state, tx, bcli->cb_arg);
+}
+
+/* FIXME: Cache! */
+void bitcoind_txid_lookup_(struct lightningd_state *state,
+			   const struct sha256_double *txid,
+			   void (*cb)(struct lightningd_state *state,
+				      const struct bitcoin_tx *tx,
+				      void *arg),
+			   void *arg)
+{
+	char txidhex[hex_str_size(sizeof(*txid))];
+
+	if (!bitcoin_txid_to_hex(txid, txidhex, sizeof(txidhex)))
+		fatal("Incorrect txid size");
+	start_bitcoin_cli(state, process_rawtx, cb, arg,
+			  "getrawtransaction", txidhex, NULL);
+}

daemon/bitcoind.h

@@ -0,0 +1,33 @@
+#ifndef LIGHTNING_DAEMON_BITCOIND_H
+#define LIGHTNING_DAEMON_BITCOIND_H
+#include "config.h"
+#include <ccan/typesafe_cb/typesafe_cb.h>
+
+struct sha256_double;
+struct lightningd_state;
+struct ripemd160;
+struct bitcoin_tx;
+
+void bitcoind_watch_addr(struct lightningd_state *state,
+			 const struct ripemd160 *redeemhash);
+
+void bitcoind_poll_transactions(struct lightningd_state *state,
+				void (*cb)(struct lightningd_state *state,
+					   const struct sha256_double *txid,
+					   int confirmations));
+
+void bitcoind_txid_lookup_(struct lightningd_state *state,
+			  const struct sha256_double *txid,
+			  void (*cb)(struct lightningd_state *state,
+				     const struct bitcoin_tx *tx, void *),
+			   void *arg);
+
+#define bitcoind_txid_lookup(state, txid, cb, arg)			\
+	bitcoind_txid_lookup_((state), (txid),				\
+			      typesafe_cb_preargs(struct io_plan *, void *, \
+						  (cb), (arg),		\
+						  struct lightningd_state *, \
+						  const struct bitcoin_tx *), \
+			      (arg))
+
+#endif /* LIGHTNING_DAEMON_BITCOIND_H */

daemon/lightningd.c

@@ -124,6 +124,7 @@ static struct lightningd_state *lightningd_state(void)
 	state->secpctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						  | SECP256K1_CONTEXT_SIGN);
 	default_config(&state->config);
+	state->bitcoind_in_progress = 0;
 	return state;
 }
 

daemon/lightningd.h

@@ -60,5 +60,8 @@ struct lightningd_state {
 
 	/* This is us. */
 	struct pubkey id;
+
+	/* Number of bitcoind commands outstanding. */
+	unsigned int bitcoind_in_progress;
 };
 #endif /* LIGHTNING_DAEMON_LIGHTNING_H */