status: new message for subdaemons to tell us their versions.

For this patch we simply abort if it's wrong.

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

common/status_wire.csv

@@ -23,4 +23,7 @@ msgtype,status_peer_connection_lost,0xFFF3
 msgtype,status_peer_billboard,0xFFF5
 msgdata,status_peer_billboard,perm,bool,
 msgdata,status_peer_billboard,happenings,wirestring,
+
+msgtype,status_version,0xFFF6
+msgdata,status_version,version,wirestring,
 # Note: 0xFFFF is reserved for MSG_PASS_FD!

common/status_wiregen.c

@@ -25,6 +25,7 @@ const char *status_wire_name(int e)
 	case WIRE_STATUS_FAIL: return "WIRE_STATUS_FAIL";
 	case WIRE_STATUS_PEER_CONNECTION_LOST: return "WIRE_STATUS_PEER_CONNECTION_LOST";
 	case WIRE_STATUS_PEER_BILLBOARD: return "WIRE_STATUS_PEER_BILLBOARD";
+	case WIRE_STATUS_VERSION: return "WIRE_STATUS_VERSION";
 	}
 
 	snprintf(invalidbuf, sizeof(invalidbuf), "INVALID %i", e);
@@ -39,6 +40,7 @@ bool status_wire_is_defined(u16 type)
 	case WIRE_STATUS_FAIL:;
 	case WIRE_STATUS_PEER_CONNECTION_LOST:;
 	case WIRE_STATUS_PEER_BILLBOARD:;
+	case WIRE_STATUS_VERSION:;
 	      return true;
 	}
 	return false;
@@ -191,4 +193,25 @@ bool fromwire_status_peer_billboard(const tal_t *ctx, const void *p, bool *perm,
  	*happenings = fromwire_wirestring(ctx, &cursor, &plen);
 	return cursor != NULL;
 }
-// SHA256STAMP:67770c6a9a4205f10a455ea925afc2be4f853642b1e7ed70e3867221c64b7abc
+
+/* WIRE: STATUS_VERSION */
+u8 *towire_status_version(const tal_t *ctx, const wirestring *version)
+{
+	u8 *p = tal_arr(ctx, u8, 0);
+
+	towire_u16(&p, WIRE_STATUS_VERSION);
+	towire_wirestring(&p, version);
+
+	return memcheck(p, tal_count(p));
+}
+bool fromwire_status_version(const tal_t *ctx, const void *p, wirestring **version)
+{
+	const u8 *cursor = p;
+	size_t plen = tal_count(p);
+
+	if (fromwire_u16(&cursor, &plen) != WIRE_STATUS_VERSION)
+		return false;
+ 	*version = fromwire_wirestring(ctx, &cursor, &plen);
+	return cursor != NULL;
+}
+// SHA256STAMP:8e1ba9cbc812c8aad76c5049fcecefea2d706a100423c93d3c3be0afcbee851e

common/status_wiregen.h

@@ -17,6 +17,7 @@ enum status_wire {
         WIRE_STATUS_FAIL = 0xFFF2,
         WIRE_STATUS_PEER_CONNECTION_LOST = 0xFFF3,
         WIRE_STATUS_PEER_BILLBOARD = 0xFFF5,
+        WIRE_STATUS_VERSION = 0xFFF6,
 };
 
 const char *status_wire_name(int e);
@@ -51,6 +52,10 @@ bool fromwire_status_peer_connection_lost(const void *p);
 u8 *towire_status_peer_billboard(const tal_t *ctx, bool perm, const wirestring *happenings);
 bool fromwire_status_peer_billboard(const tal_t *ctx, const void *p, bool *perm, wirestring **happenings);
 
+/* WIRE: STATUS_VERSION */
+u8 *towire_status_version(const tal_t *ctx, const wirestring *version);
+bool fromwire_status_version(const tal_t *ctx, const void *p, wirestring **version);
+
 
 #endif /* LIGHTNING_COMMON_STATUS_WIREGEN_H */
-// SHA256STAMP:67770c6a9a4205f10a455ea925afc2be4f853642b1e7ed70e3867221c64b7abc
+// SHA256STAMP:8e1ba9cbc812c8aad76c5049fcecefea2d706a100423c93d3c3be0afcbee851e

lightningd/subd.c

@@ -1,3 +1,4 @@
+#include <ccan/array_size/array_size.h>
 #include <ccan/err/err.h>
 #include <ccan/io/fdpass/fdpass.h>
 #include <ccan/io/io.h>
@@ -12,6 +13,7 @@
 #include <common/peer_status_wiregen.h>
 #include <common/per_peer_state.h>
 #include <common/status_wiregen.h>
+#include <common/version.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <lightningd/lightningd.h>
@@ -402,6 +404,20 @@ static bool handle_set_billboard(struct subd *sd, const u8 *msg)
 	return true;
 }
 
+static bool handle_version(struct subd *sd, const u8 *msg)
+{
+	char *ver;
+
+	if (!fromwire_status_version(msg, msg, &ver))
+		return false;
+
+	if (!streq(ver, version())) {
+		fatal("subdaemon %s version '%s' not '%s'",
+		      sd->name, ver, version());
+	}
+	return true;
+}
+
 static struct io_plan *sd_msg_read(struct io_conn *conn, struct subd *sd)
 {
 	int type = fromwire_peektype(sd->msg_in);
@@ -455,6 +471,10 @@ static struct io_plan *sd_msg_read(struct io_conn *conn, struct subd *sd)
 		if (!handle_set_billboard(sd, sd->msg_in))
 			goto malformed;
 		goto next;
+	case WIRE_STATUS_VERSION:
+		if (!handle_version(sd, sd->msg_in))
+			goto malformed;
+		goto next;
 	}
 
 	if (sd->channel) {

lightningd/test/run-find_my_abspath.c

@@ -90,6 +90,9 @@ bool fromwire_status_peer_billboard(const tal_t *ctx UNNEEDED, const void *p UNN
 /* Generated stub for fromwire_status_peer_error */
 bool fromwire_status_peer_error(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, struct channel_id *channel UNNEEDED, wirestring **desc UNNEEDED, bool *warning UNNEEDED, struct per_peer_state **pps UNNEEDED, u8 **error_for_them UNNEEDED)
 { fprintf(stderr, "fromwire_status_peer_error called!\n"); abort(); }
+/* Generated stub for fromwire_status_version */
+bool fromwire_status_version(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, wirestring **version UNNEEDED)
+{ fprintf(stderr, "fromwire_status_version called!\n"); abort(); }
 /* Generated stub for gossip_init */
 void gossip_init(struct lightningd *ld UNNEEDED, int connectd_fd UNNEEDED)
 { fprintf(stderr, "gossip_init called!\n"); abort(); }