common: move gossip_store read routine where subdaemons can access it.

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

common/Makefile

@@ -18,6 +18,7 @@ COMMON_SRC_NOGEN :=				\
 	common/dev_disconnect.c			\
 	common/features.c			\
 	common/funding_tx.c			\
+	common/gossip_store.c			\
 	common/hash_u5.c			\
 	common/htlc_state.c			\
 	common/htlc_tx.c			\

common/gossip_store.c

@@ -0,0 +1,41 @@
+#include <ccan/crc/crc.h>
+#include <ccan/endian/endian.h>
+#include <common/gossip_store.h>
+#include <common/status.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <unistd.h>
+
+u8 *gossip_store_read(const tal_t *ctx, int gossip_store_fd, u64 offset)
+{
+	beint32_t hdr[2];
+	u32 msglen, checksum;
+	u8 *msg;
+
+	if (offset == 0)
+		status_failed(STATUS_FAIL_INTERNAL_ERROR,
+			      "gossip_store: can't access offset %"PRIu64,
+			      offset);
+	if (pread(gossip_store_fd, hdr, sizeof(hdr), offset) != sizeof(hdr)) {
+		status_failed(STATUS_FAIL_INTERNAL_ERROR,
+			      "gossip_store: can't read hdr offset %"PRIu64
+			      ": %s",
+			      offset, strerror(errno));
+	}
+
+	msglen = be32_to_cpu(hdr[0]);
+	checksum = be32_to_cpu(hdr[1]);
+	msg = tal_arr(ctx, u8, msglen);
+	if (pread(gossip_store_fd, msg, msglen, offset + sizeof(hdr)) != msglen)
+		status_failed(STATUS_FAIL_INTERNAL_ERROR,
+			      "gossip_store: can't read len %u offset %"PRIu64,
+			      msglen, offset);
+
+	if (checksum != crc32c(0, msg, msglen))
+		status_failed(STATUS_FAIL_INTERNAL_ERROR,
+			      "gossip_store: bad checksum offset %"PRIu64,
+			      offset);
+
+	return msg;
+}
+

common/gossip_store.h

@@ -0,0 +1,19 @@
+#ifndef LIGHTNING_COMMON_GOSSIP_STORE_H
+#define LIGHTNING_COMMON_GOSSIP_STORE_H
+#include "config.h"
+#include <ccan/short_types/short_types.h>
+#include <ccan/tal/tal.h>
+
+/**
+ * gossip_store -- On-disk storage related information
+ */
+#define GOSSIP_STORE_VERSION 4
+
+/**
+ * Direct store accessor: loads gossip msg from store.
+ *
+ * Doesn't return; status_failed() on error.
+ */
+u8 *gossip_store_read(const tal_t *ctx, int gossip_store_fd, u64 offset);
+
+#endif /* LIGHTNING_COMMON_GOSSIP_STORE_H */

devtools/create-gossipstore.c

@@ -4,11 +4,12 @@
 #include <ccan/opt/opt.h>
 #include <ccan/read_write_all/read_write_all.h>
 #include <common/amount.h>
+#include <common/gossip_store.h>
+#include <common/node_id.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 <stdlib.h>

devtools/dump-gossipstore.c

@@ -3,9 +3,9 @@
 #include <common/type_to_string.h>
 #include <common/utils.h>
 #include <fcntl.h>
+#include <common/gossip_store.h>
 #include <gossipd/gen_gossip_peerd_wire.h>
 #include <gossipd/gen_gossip_store.h>
-#include <gossipd/gossip_store.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <sys/stat.h>

gossipd/Makefile

@@ -50,6 +50,7 @@ GOSSIPD_COMMON_OBJS :=				\
 	common/dev_disconnect.o			\
 	common/features.o			\
 	common/gen_status_wire.o		\
+	common/gossip_store.o			\
 	common/key_derive.o			\
 	common/memleak.o			\
 	common/msg_queue.o			\

gossipd/gossip_store.c

@@ -3,6 +3,7 @@
 #include <ccan/crc/crc.h>
 #include <ccan/endian/endian.h>
 #include <ccan/read_write_all/read_write_all.h>
+#include <common/gossip_store.h>
 #include <common/status.h>
 #include <common/utils.h>
 #include <errno.h>
@@ -531,38 +532,7 @@ const u8 *gossip_store_get(const tal_t *ctx,
 			   struct gossip_store *gs,
 			   u64 offset)
 {
-	beint32_t hdr[2];
+	return gossip_store_read(ctx, gs->fd, offset);
-	u32 msglen, checksum;
-	u8 *msg;
-
-	if (offset == 0 || offset > gs->len)
-		status_failed(STATUS_FAIL_INTERNAL_ERROR,
-			      "gossip_store: can't access offset %"PRIu64
-			      ", store len %"PRIu64,
-			      offset, gs->len);
-	if (pread(gs->fd, hdr, sizeof(hdr), offset) != sizeof(hdr)) {
-		status_failed(STATUS_FAIL_INTERNAL_ERROR,
-			      "gossip_store: can't read hdr offset %"PRIu64
-			      ", store len %"PRIu64": %s",
-			      offset, gs->len, strerror(errno));
-	}
-
-	msglen = be32_to_cpu(hdr[0]);
-	checksum = be32_to_cpu(hdr[1]);
-	msg = tal_arr(ctx, u8, msglen);
-	if (pread(gs->fd, msg, msglen, offset + sizeof(hdr)) != msglen)
-		status_failed(STATUS_FAIL_INTERNAL_ERROR,
-			      "gossip_store: can't read len %u offset %"PRIu64
-			      ", store len %"PRIu64,
-			      msglen, offset, gs->len);
-
-	if (checksum != crc32c(0, msg, msglen))
-		status_failed(STATUS_FAIL_INTERNAL_ERROR,
-			      "gossip_store: bad checksum offset %"PRIu64
-			      ", store len %"PRIu64,
-			      offset, gs->len);
-
-	return msg;
 }
 
 int gossip_store_readonly_fd(struct gossip_store *gs)

gossipd/gossip_store.h

@@ -11,7 +11,6 @@
 /**
  * gossip_store -- On-disk storage related information
  */
-#define GOSSIP_STORE_VERSION 4
 
 struct broadcast_state;
 struct gossip_store;

gossipd/test/run-bench-find_route.c

@@ -69,6 +69,9 @@ u16 fromwire_u16(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 /* Generated stub for fromwire_wireaddr */
 bool fromwire_wireaddr(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct wireaddr *addr UNNEEDED)
 { fprintf(stderr, "fromwire_wireaddr called!\n"); abort(); }
+/* Generated stub for gossip_store_read */
+u8 *gossip_store_read(const tal_t *ctx UNNEEDED, int gossip_store_fd UNNEEDED, u64 offset UNNEEDED)
+{ fprintf(stderr, "gossip_store_read called!\n"); abort(); }
 /* Generated stub for onion_type_name */
 const char *onion_type_name(int e UNNEEDED)
 { fprintf(stderr, "onion_type_name called!\n"); abort(); }

gossipd/test/run-find_route-specific.c

@@ -58,6 +58,9 @@ u16 fromwire_u16(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 /* Generated stub for fromwire_wireaddr */
 bool fromwire_wireaddr(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct wireaddr *addr UNNEEDED)
 { fprintf(stderr, "fromwire_wireaddr called!\n"); abort(); }
+/* Generated stub for gossip_store_read */
+u8 *gossip_store_read(const tal_t *ctx UNNEEDED, int gossip_store_fd UNNEEDED, u64 offset UNNEEDED)
+{ fprintf(stderr, "gossip_store_read called!\n"); abort(); }
 /* Generated stub for onion_type_name */
 const char *onion_type_name(int e UNNEEDED)
 { fprintf(stderr, "onion_type_name called!\n"); abort(); }

gossipd/test/run-find_route.c

@@ -56,6 +56,9 @@ u16 fromwire_u16(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 /* Generated stub for fromwire_wireaddr */
 bool fromwire_wireaddr(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct wireaddr *addr UNNEEDED)
 { fprintf(stderr, "fromwire_wireaddr called!\n"); abort(); }
+/* Generated stub for gossip_store_read */
+u8 *gossip_store_read(const tal_t *ctx UNNEEDED, int gossip_store_fd UNNEEDED, u64 offset UNNEEDED)
+{ fprintf(stderr, "gossip_store_read called!\n"); abort(); }
 /* Generated stub for onion_type_name */
 const char *onion_type_name(int e UNNEEDED)
 { fprintf(stderr, "onion_type_name called!\n"); abort(); }

gossipd/test/run-overlong.c

@@ -56,6 +56,9 @@ u16 fromwire_u16(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 /* Generated stub for fromwire_wireaddr */
 bool fromwire_wireaddr(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct wireaddr *addr UNNEEDED)
 { fprintf(stderr, "fromwire_wireaddr called!\n"); abort(); }
+/* Generated stub for gossip_store_read */
+u8 *gossip_store_read(const tal_t *ctx UNNEEDED, int gossip_store_fd UNNEEDED, u64 offset UNNEEDED)
+{ fprintf(stderr, "gossip_store_read called!\n"); abort(); }
 /* Generated stub for onion_type_name */
 const char *onion_type_name(int e UNNEEDED)
 { fprintf(stderr, "onion_type_name called!\n"); abort(); }