1 files changed, 316 insertions, 0 deletions
diff --git a/lib/tsocket/tsocket_writev.c b/lib/tsocket/tsocket_writev.c
new file mode 100644
index 0000000000..8c5cd40385
--- /dev/null
+++ b/lib/tsocket/tsocket_writev.c
@@ -0,0 +1,316 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   Copyright (C) Stefan Metzmacher 2009
+
+     ** NOTE! The following LGPL license applies to the tevent
+     ** library. This does NOT imply that all of Samba is released
+     ** under the LGPL
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "replace.h"
+#include "system/network.h"
+#include "tsocket.h"
+#include "tsocket_internal.h"
+
+struct tsocket_writev_state {
+	/* this structs are owned by the caller */
+	struct {
+		struct tsocket_context *sock;
+		const struct iovec *vector;
+		size_t count;
+	} caller;
+
+	struct iovec *iov;
+	size_t count;
+	int total_written;
+};
+
+static int tsocket_writev_state_destructor(struct tsocket_writev_state *state)
+{
+	if (state->caller.sock) {
+		tsocket_set_writeable_handler(state->caller.sock, NULL, NULL);
+	}
+	ZERO_STRUCT(state->caller);
+
+	return 0;
+}
+
+static void tsocket_writev_handler(struct tsocket_context *sock,
+				   void *private_data);
+
+struct tevent_req *tsocket_writev_send(struct tsocket_context *sock,
+				       TALLOC_CTX *mem_ctx,
+				       const struct iovec *vector,
+				       size_t count)
+{
+	struct tevent_req *req;
+	struct tsocket_writev_state *state;
+	int ret;
+	int err;
+	bool dummy;
+	int to_write = 0;
+	size_t i;
+
+	req = tevent_req_create(mem_ctx, &state,
+				struct tsocket_writev_state);
+	if (!req) {
+		return NULL;
+	}
+
+	state->caller.sock	= sock;
+	state->caller.vector	= vector;
+	state->caller.count	= count;
+
+	state->iov		= NULL;
+	state->count		= count;
+	state->total_written	= 0;
+
+	state->iov = talloc_array(state, struct iovec, count);
+	if (tevent_req_nomem(state->iov, req)) {
+		goto post;
+	}
+	memcpy(state->iov, vector, sizeof(struct iovec) * count);
+
+	for (i=0; i < count; i++) {
+		int tmp = to_write;
+
+		tmp += state->iov[i].iov_len;
+
+		if (tmp < to_write) {
+			tevent_req_error(req, EMSGSIZE);
+			goto post;
+		}
+
+		to_write = tmp;
+	}
+
+	if (to_write == 0) {
+		tevent_req_done(req);
+		goto post;
+	}
+
+	/*
+	 * this is a fast path, not waiting for the
+	 * socket to become explicit writeable gains
+	 * about 10%-20% performance in benchmark tests.
+	 */
+	tsocket_writev_handler(sock, req);
+	if (!tevent_req_is_in_progress(req)) {
+		goto post;
+	}
+
+	talloc_set_destructor(state, tsocket_writev_state_destructor);
+
+	ret = tsocket_set_writeable_handler(sock,
+					    tsocket_writev_handler,
+					    req);
+	err = tsocket_error_from_errno(ret, errno, &dummy);
+	if (tevent_req_error(req, err)) {
+		goto post;
+	}
+
+	return req;
+
+ post:
+	return tevent_req_post(req, sock->event.ctx);
+}
+
+static void tsocket_writev_handler(struct tsocket_context *sock,
+				   void *private_data)
+{
+	struct tevent_req *req = talloc_get_type(private_data,
+				 struct tevent_req);
+	struct tsocket_writev_state *state = tevent_req_data(req,
+					     struct tsocket_writev_state);
+	int ret;
+	int err;
+	bool retry;
+
+	ret = tsocket_writev(state->caller.sock,
+			     state->iov,
+			     state->count);
+	err = tsocket_error_from_errno(ret, errno, &retry);
+	if (retry) {
+		/* retry later */
+		return;
+	}
+	if (tevent_req_error(req, err)) {
+		return;
+	}
+
+	state->total_written += ret;
+
+	/*
+	 * we have not written everything yet, so we need to truncate
+	 * the already written bytes from our iov copy
+	 */
+	while (ret > 0) {
+		if (ret < state->iov[0].iov_len) {
+			uint8_t *base;
+			base = (uint8_t *)state->iov[0].iov_base;
+			base += ret;
+			state->iov[0].iov_base = base;
+			state->iov[0].iov_len -= ret;
+			break;
+		}
+		ret -= state->iov[0].iov_len;
+		state->iov += 1;
+		state->count -= 1;
+	}
+
+	if (state->count > 0) {
+		/* more to write */
+		return;
+	}
+
+	tevent_req_done(req);
+}
+
+int tsocket_writev_recv(struct tevent_req *req, int *perrno)
+{
+	struct tsocket_writev_state *state = tevent_req_data(req,
+					     struct tsocket_writev_state);
+	int ret;
+
+	ret = tsocket_simple_int_recv(req, perrno);
+	if (ret == 0) {
+		ret = state->total_written;
+	}
+
+	tevent_req_received(req);
+	return ret;
+}
+
+struct tsocket_writev_queue_state {
+	/* this structs are owned by the caller */
+	struct {
+		struct tsocket_context *sock;
+		const struct iovec *vector;
+		size_t count;
+	} caller;
+	int ret;
+};
+
+static void tsocket_writev_queue_trigger(struct tevent_req *req,
+					 void *private_data);
+static void tsocket_writev_queue_done(struct tevent_req *subreq);
+
+/**
+ * @brief Queue a dgram blob for sending through the socket
+ * @param[in] mem_ctx	The memory context for the result
+ * @param[in] sock	The socket to send data through
+ * @param[in] queue	The existing send queue
+ * @param[in] vector	The iovec vector so write
+ * @param[in] count	The size of the vector
+ * @retval		The async request handle
+ *
+ * This function queues a blob for sending to destination through an existing
+ * dgram socket. The async callback is triggered when the whole blob is
+ * delivered to the underlying system socket.
+ *
+ * The caller needs to make sure that all non-scalar input parameters hang
+ * arround for the whole lifetime of the request.
+ */
+struct tevent_req *tsocket_writev_queue_send(TALLOC_CTX *mem_ctx,
+					     struct tsocket_context *sock,
+					     struct tevent_queue *queue,
+					     const struct iovec *vector,
+					     size_t count)
+{
+	struct tevent_req *req;
+	struct tsocket_writev_queue_state *state;
+	bool ok;
+
+	req = tevent_req_create(mem_ctx, &state,
+				struct tsocket_writev_queue_state);
+	if (!req) {
+		return NULL;
+	}
+
+	state->caller.sock	= sock;
+	state->caller.vector	= vector;
+	state->caller.count	= count;
+	state->ret		= -1;
+
+	ok = tevent_queue_add(queue,
+			      sock->event.ctx,
+			      req,
+			      tsocket_writev_queue_trigger,
+			      NULL);
+	if (!ok) {
+		tevent_req_nomem(NULL, req);
+		goto post;
+	}
+
+	return req;
+
+ post:
+	return tevent_req_post(req, sock->event.ctx);
+}
+
+static void tsocket_writev_queue_trigger(struct tevent_req *req,
+					 void *private_data)
+{
+	struct tsocket_writev_queue_state *state = tevent_req_data(req,
+					struct tsocket_writev_queue_state);
+	struct tevent_req *subreq;
+
+	subreq = tsocket_writev_send(state->caller.sock,
+				     state,
+				     state->caller.vector,
+				     state->caller.count);
+	if (tevent_req_nomem(subreq, req)) {
+		return;
+	}
+	tevent_req_set_callback(subreq, tsocket_writev_queue_done ,req);
+}
+
+static void tsocket_writev_queue_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(subreq,
+				 struct tevent_req);
+	struct tsocket_writev_queue_state *state = tevent_req_data(req,
+					struct tsocket_writev_queue_state);
+	int ret;
+	int sys_errno;
+
+	ret = tsocket_writev_recv(subreq, &sys_errno);
+	talloc_free(subreq);
+	if (ret == -1) {
+		tevent_req_error(req, sys_errno);
+		return;
+	}
+	state->ret = ret;
+
+	tevent_req_done(req);
+}
+
+int tsocket_writev_queue_recv(struct tevent_req *req, int *perrno)
+{
+	struct tsocket_writev_queue_state *state = tevent_req_data(req,
+					struct tsocket_writev_queue_state);
+	int ret;
+
+	ret = tsocket_simple_int_recv(req, perrno);
+	if (ret == 0) {
+		ret = state->ret;
+	}
+
+	tevent_req_received(req);
+	return ret;
+}
+