messaging3: Move messaging_hdr handling to messages.c.

This makes messages_dgm a simple byte-transport across processes that
knows almost nothing about server_id etc.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

1 files changed, 39 insertions, 10 deletions

diff --git a/source3/lib/messages.c b/source3/lib/messages.c
index 12419f89e2..7aa660aa36 100644
--- a/source3/lib/messages.c
+++ b/source3/lib/messages.c
@@ -77,6 +77,12 @@ struct messaging_context {
 	struct messaging_backend *remote;
 };
 
+struct messaging_hdr {
+	int msg_type;
+	struct server_id dst;
+	struct server_id src;
+};
+
 /****************************************************************************
  A useful function for testing the message system.
 ****************************************************************************/
@@ -198,22 +204,36 @@ bool message_send_all(struct messaging_context *msg_ctx,
 	return true;
 }
 
-static void messaging_recv_cb(int msg_type,
-			      struct server_id src, struct server_id dst,
-			      const uint8_t *msg, size_t msg_len,
+static void messaging_recv_cb(const uint8_t *msg, size_t msg_len,
 			      void *private_data)
 {
 	struct messaging_context *msg_ctx = talloc_get_type_abort(
 		private_data, struct messaging_context);
+	const struct messaging_hdr *hdr;
+	struct server_id_buf idbuf;
 	struct messaging_rec rec;
 
+	if (msg_len < sizeof(*hdr)) {
+		DEBUG(1, ("message too short: %u\n", (unsigned)msg_len));
+		return;
+	}
+
+	/*
+	 * messages_dgm guarantees alignment, so we can cast here
+	 */
+	hdr = (const struct messaging_hdr *)msg;
+
+	DEBUG(10, ("%s: Received message 0x%x len %u from %s\n", __func__,
+		   (unsigned)hdr->msg_type, (unsigned)(msg_len - sizeof(*hdr)),
+		   server_id_str_buf(hdr->src, &idbuf)));
+
 	rec = (struct messaging_rec) {
 		.msg_version = MESSAGE_VERSION,
-		.msg_type = msg_type,
-		.src = src,
-		.dest = dst,
-		.buf.data = discard_const_p(uint8, msg),
-		.buf.length = msg_len
+		.msg_type = hdr->msg_type,
+		.src = hdr->src,
+		.dest = hdr->dst,
+		.buf.data = discard_const_p(uint8, msg) + sizeof(*hdr),
+		.buf.length = msg_len - sizeof(*hdr)
 	};
 
 	messaging_dispatch_rec(msg_ctx, &rec);
@@ -417,6 +437,8 @@ NTSTATUS messaging_send_iov(struct messaging_context *msg_ctx,
 			    const struct iovec *iov, int iovlen)
 {
 	int ret;
+	struct messaging_hdr hdr;
+	struct iovec iov2[iovlen+1];
 
 	if (server_id_is_disconnected(&server)) {
 		return NT_STATUS_INVALID_PARAMETER_MIX;
@@ -451,9 +473,16 @@ NTSTATUS messaging_send_iov(struct messaging_context *msg_ctx,
 		return NT_STATUS_OK;
 	}
 
+	hdr = (struct messaging_hdr) {
+		.msg_type = msg_type,
+		.dst = server,
+		.src = msg_ctx->id
+	};
+	iov2[0] = (struct iovec){ .iov_base = &hdr, .iov_len = sizeof(hdr) };
+	memcpy(&iov2[1], iov, iovlen * sizeof(*iov));
+
 	become_root();
-	ret = messaging_dgm_send(msg_ctx->local, msg_ctx->id, server, msg_type,
-				 iov, iovlen);
+	ret = messaging_dgm_send(msg_ctx->local, server.pid, iov2, iovlen+1);
 	unbecome_root();
 
 	if (ret != 0) {