devtools: dump-gossipstore.

Not very useful by itself, but when combined with decodemsg it can tell
us quite a bit.

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

devtools/.gitignore

@@ -1,3 +1,4 @@
 bolt11-cli
 decodemsg
 onion
+dump-gossipstore

devtools/Makefile

@@ -1,6 +1,6 @@
 DEVTOOLS_SRC := devtools/gen_print_wire.c devtools/gen_print_onion_wire.c devtools/print_wire.c
 DEVTOOLS_OBJS := $(DEVTOOLS_SRC:.c=.o)
-DEVTOOLS_TOOL_SRC := devtools/bolt11-cli.c devtools/decodemsg.c devtools/onion.c
+DEVTOOLS_TOOL_SRC := devtools/bolt11-cli.c devtools/decodemsg.c devtools/onion.c devtools/dump-gossipstore.c
 DEVTOOLS_TOOL_OBJS := $(DEVTOOLS_TOOL_SRC:.c=.o)
 
 DEVTOOLS_COMMON_OBJS :=				\
@@ -15,7 +15,7 @@ DEVTOOLS_COMMON_OBJS :=				\
 	common/version.o			\
 	common/wireaddr.o
 
-devtools-all: devtools/bolt11-cli devtools/decodemsg devtools/onion
+devtools-all: devtools/bolt11-cli devtools/decodemsg devtools/onion devtools/dump-gossipstore
 
 devtools/gen_print_wire.h: $(WIRE_GEN) wire/gen_peer_wire_csv
 	$(WIRE_GEN) --bolt --printwire --header $@ wire_type < wire/gen_peer_wire_csv > $@
@@ -33,6 +33,9 @@ devtools/bolt11-cli: $(DEVTOOLS_OBJS) $(DEVTOOLS_COMMON_OBJS) $(JSMN_OBJS) $(CCA
 
 devtools/decodemsg: $(DEVTOOLS_OBJS) $(DEVTOOLS_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS) $(BITCOIN_OBJS) wire/fromwire.o wire/towire.o devtools/decodemsg.o
 
+devtools/dump-gossipstore: $(DEVTOOLS_OBJS) $(DEVTOOLS_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS) $(BITCOIN_OBJS) wire/fromwire.o wire/towire.o devtools/dump-gossipstore.o gossipd/gen_gossip_store.o
+
+devtools/dump-gossipstore.o: gossipd/gen_gossip_store.h
 devtools/onion.c: ccan/config.h
 
 devtools/onion: $(DEVTOOLS_OBJS) $(DEVTOOLS_COMMON_OBJS) $(JSMN_OBJS) $(CCAN_OBJS) $(BITCOIN_OBJS) wire/fromwire.o wire/towire.o devtools/onion.o common/sphinx.o
@@ -42,7 +45,7 @@ devtools/gen_print_wire.o: devtools/gen_print_wire.h wire/gen_peer_wire.h devtoo
 devtools/gen_print_onion_wire.o: devtools/gen_print_onion_wire.h devtools/print_wire.h
 
 # Make sure these depend on everything.
-ALL_PROGRAMS += devtools/bolt11-cli devtools/decodemsg devtools/onion
+ALL_PROGRAMS += devtools/bolt11-cli devtools/decodemsg devtools/onion devtools/dump-gossipstore
 ALL_OBJS += $(DEVTOOLS_OBJS) $(DEVTOOLS_TOOL_OBJS)
 
 check-source: $(DEVTOOLS_SRC:%=check-src-include-order/%) $(DEVTOOLS_TOOLS_SRC:%=check-src-include-order/%)

devtools/dump-gossipstore.c

@@ -0,0 +1,82 @@
+#include <ccan/crc/crc.h>
+#include <ccan/err/err.h>
+#include <common/type_to_string.h>
+#include <common/utils.h>
+#include <fcntl.h>
+#include <gossipd/gen_gossip_store.h>
+#include <gossipd/gossip_store.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[])
+{
+	int fd;
+	u8 version;
+	beint32_t belen, becsum;
+
+	setup_locale();
+
+	if (argc > 2)
+		errx(1, "Need the filename of a gossip store, or stdin");
+
+	if (argc == 2) {
+		fd = open(argv[1], O_RDONLY);
+		if (fd < 0)
+			err(1, "Opening %s", argv[1]);
+	} else
+		fd = STDIN_FILENO;
+
+	if (read(fd, &version, sizeof(version)) != sizeof(version))
+		errx(1, "Empty file");
+
+	if (version != GOSSIP_STORE_VERSION)
+		warnx("UNSUPPORTED GOSSIP VERSION %u (expected %u)",
+		      version, GOSSIP_STORE_VERSION);
+
+	printf("GOSSIP VERSION %u\n", version);
+
+	while (read(fd, &belen, sizeof(belen)) == sizeof(belen) &&
+	       read(fd, &becsum, sizeof(becsum)) == sizeof(becsum)) {
+		u64 satoshis;
+		struct short_channel_id scid;
+		u8 *gossip_msg;
+		u32 msglen = be32_to_cpu(belen);
+		u8 *msg = tal_arr(NULL, u8, msglen);
+
+		if (read(fd, msg, msglen) != msglen)
+			errx(1, "Truncated file?");
+
+		if (be32_to_cpu(becsum) != crc32c(0, msg, msglen))
+			warnx("Checksum verification failed");
+
+		if (fromwire_gossip_store_channel_announcement(msg, msg,
+							       &gossip_msg,
+							       &satoshis)) {
+			printf("channel_announce for %"PRIu64" satoshis: %s\n",
+			       satoshis, tal_hex(msg, gossip_msg));
+		} else if (fromwire_gossip_store_channel_update(msg, msg,
+								&gossip_msg)) {
+			printf("channel_update: %s\n",
+			       tal_hex(msg, gossip_msg));
+		} else if (fromwire_gossip_store_node_announcement(msg, msg,
+								   &gossip_msg)) {
+			printf("node_announcement: %s\n",
+			       tal_hex(msg, gossip_msg));
+		} else if (fromwire_gossip_store_channel_delete(msg, &scid)) {
+			printf("channel_delete: %s\n",
+			       type_to_string(msg, struct short_channel_id,
+					      &scid));
+		} else if (fromwire_gossip_store_local_add_channel(
+			       msg, msg, &gossip_msg)) {
+			printf("local_add_channel: %s\n",
+			       tal_hex(msg, gossip_msg));
+		} else {
+			warnx("Unknown message %u", fromwire_peektype(msg));
+		}
+		tal_free(msg);
+	}
+	return 0;
+}

gossipd/gossip_store.c

@@ -16,7 +16,6 @@
 
 #define GOSSIP_STORE_FILENAME "gossip_store"
 #define GOSSIP_STORE_TEMP_FILENAME "gossip_store.tmp"
-static u8 gossip_store_version = 0x02;
 
 struct gossip_store {
 	int fd;
@@ -62,17 +61,17 @@ struct gossip_store *gossip_store_new(const tal_t *ctx,
 	if (read(gs->fd, &gs->version, sizeof(gs->version))
 	    == sizeof(gs->version)) {
 		/* Version match?  All good */
-		if (gs->version == gossip_store_version)
+		if (gs->version == GOSSIP_STORE_VERSION)
 			return gs;
 
 		status_unusual("Gossip store version %u not %u: removing",
-			       gs->version, gossip_store_version);
+			       gs->version, GOSSIP_STORE_VERSION);
 		if (ftruncate(gs->fd, 0) != 0)
 			status_failed(STATUS_FAIL_INTERNAL_ERROR,
 				      "Truncating store: %s", strerror(errno));
 	}
 	/* Empty file, write version byte */
-	gs->version = gossip_store_version;
+	gs->version = GOSSIP_STORE_VERSION;
 	if (write(gs->fd, &gs->version, sizeof(gs->version))
 	    != sizeof(gs->version))
 		status_failed(STATUS_FAIL_INTERNAL_ERROR,
@@ -177,8 +176,8 @@ static void gossip_store_compact(struct gossip_store *gs)
 		goto disable;
 	}
 
-	if (write(fd, &gossip_store_version, sizeof(gossip_store_version))
-	    != sizeof(gossip_store_version)) {
+	if (write(fd, &gs->version, sizeof(gs->version))
+	    != sizeof(gs->version)) {
 		status_broken("Writing version to store: %s", strerror(errno));
 		goto unlink_disable;
 	}

gossipd/gossip_store.h

@@ -11,6 +11,8 @@
 /**
  * gossip_store -- On-disk storage related information
  */
+#define GOSSIP_STORE_VERSION 2
+
 struct gossip_store;
 struct routing_state;