dcerpc server output now copes with the client blocking part way

through a read. This happens to also avoid a memcpy on output for
dcerpc over tcp.
(This used to be commit e7c53ad1856e299d82d84b5837189ae3191c32de)

1 files changed, 44 insertions, 9 deletions

diff --git a/source4/rpc_server/dcerpc_server.c b/source4/rpc_server/dcerpc_server.c
index a4f5fb9768..0553537cb5 100644
--- a/source4/rpc_server/dcerpc_server.c
+++ b/source4/rpc_server/dcerpc_server.c
@@ -885,14 +885,23 @@ NTSTATUS dcesrv_input(struct dcesrv_connection *dce_conn, const DATA_BLOB *data)
 }
 
 /*
-  retrieve some output from a dcerpc server. The amount of data that
-  is wanted is in data->length and data->data is already allocated
-  to hold that much data.
+  retrieve some output from a dcerpc server
+  The caller supplies a function that will be called to do the
+  actual output. 
+
+  The first argument to write_fn() will be 'private', the second will
+  be a pointer to a buffer containing the data to be sent and the 3rd
+  will be the number of bytes to be sent.
+
+  write_fn() should return the number of bytes successfully written.
 */
-NTSTATUS dcesrv_output(struct dcesrv_connection *dce_conn, DATA_BLOB *data)
+NTSTATUS dcesrv_output(struct dcesrv_connection *dce_conn, 
+		       void *private,
+		       ssize_t (*write_fn)(void *, const void *, size_t))
 {
 	struct dcesrv_call_state *call;
 	struct dcesrv_call_reply *rep;
+	ssize_t nwritten;
 
 	call = dce_conn->call_list;
 	if (!call || !call->replies) {
@@ -900,13 +909,15 @@ NTSTATUS dcesrv_output(struct dcesrv_connection *dce_conn, DATA_BLOB *data)
 	}
 	rep = call->replies;
 
-	if (data->length >= rep->data.length) {
-		data->length = rep->data.length;
+	nwritten = write_fn(private, rep->data.data, rep->data.length);
+	if (nwritten == -1) {
+		/* TODO: hmm, how do we cope with this? destroy the
+		   connection perhaps? */
+		return NT_STATUS_UNSUCCESSFUL;
 	}
 
-	memcpy(data->data, rep->data.data, data->length);
-	rep->data.length -= data->length;
-	rep->data.data += data->length;
+	rep->data.length -= nwritten;
+	rep->data.data += nwritten;
 
 	if (rep->data.length == 0) {
 		/* we're done with this section of the call */
@@ -922,6 +933,30 @@ NTSTATUS dcesrv_output(struct dcesrv_connection *dce_conn, DATA_BLOB *data)
 	return NT_STATUS_OK;
 }
 
+
+/*
+  write_fn() for dcesrv_output_blob()
+*/
+static ssize_t dcesrv_output_blob_write_fn(void *private, const void *buf, size_t count)
+{
+	DATA_BLOB *blob = private;
+	if (count < blob->length) {
+		blob->length = count;
+	}
+	memcpy(blob->data, buf, blob->length);
+	return blob->length;
+}
+
+/*
+  a simple wrapper for dcesrv_output() for when we want to output
+  into a data blob
+*/
+NTSTATUS dcesrv_output_blob(struct dcesrv_connection *dce_conn, 
+			    DATA_BLOB *blob)
+{
+	return dcesrv_output(dce_conn, blob, dcesrv_output_blob_write_fn);
+}
+
 /*
   initialise the dcerpc server context
 */