1 files changed, 129 insertions, 0 deletions
diff --git a/ctdb/common/sock_client.h b/ctdb/common/sock_client.h
new file mode 100644
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+++ b/ctdb/common/sock_client.h
@@ -0,0 +1,129 @@
+/*
+   A client based on unix domain socket
+
+   Copyright (C) Amitay Isaacs  2017
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __CTDB_SOCK_CLIENT_H__
+#define __CTDB_SOCK_CLIENT_H__
+
+#include <talloc.h>
+#include <tevent.h>
+
+/**
+ * @file sock_client.h
+ *
+ * @brief A framework for a client based on unix-domain sockets.
+ *
+ * This abstraction allows one to build clients that communicate using
+ * unix-domain sockets.  It takes care of the common boilerplate.
+ */
+
+/**
+ * @brief The abstract socket daemon context
+ */
+struct sock_client_context;
+
+/**
+ * @brief callback function
+ *
+ * This function can be registered to be called in case daemon goes away.
+ */
+typedef void (*sock_client_callback_func_t)(void *private_data);
+
+/**
+ * @brief Protocol marshalling functions
+ *
+ * The typical protocol packet will have a header and a payload.
+ * Header will contain at least 2 fields: length and reqid
+ *
+ * request_push() is called when the request packet needs to be marshalled
+ *
+ * reply_pull() is called to unmarshall data into a reply packet
+ *
+ * reply_reqid() is called to extract request id from a reply packet
+ */
+struct sock_client_proto_funcs {
+	int (*request_push)(void *request, uint32_t reqid,
+			    TALLOC_CTX *mem_ctx,
+			    uint8_t **buf, size_t *buflen,
+			    void *private_data);
+
+	int (*reply_pull)(uint8_t *buf, size_t buflen,
+			  TALLOC_CTX *mem_ctx, void **reply,
+			  void *private_data);
+
+	int (*reply_reqid)(uint8_t *buf, size_t buflen,
+			   uint32_t *reqid, void *private_data);
+};
+
+/**
+ * @brief Create a new socket client
+ *
+ * @param[in] mem_ctx Talloc memory context
+ * @param[in] ev Tevent context
+ * @param[in] sockpath Unix domain socket path
+ * @param[in] funcs Protocol marshalling functions
+ * @param[in] private_data Private data for protocol functions
+ * @param[out] result New socket client context
+ * @return 0 on success, errno on failure
+ */
+int sock_client_setup(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+		      const char *sockpath,
+		      struct sock_client_proto_funcs *funcs,
+		      void *private_data,
+		      struct sock_client_context **result);
+
+/**
+ * @brief Register a callback in case of client disconnection
+ *
+ * @param[in] sockc Socket client context
+ * @param[in] callback Callback function
+ * @param[in] private_data Private data for callback function
+ */
+void sock_client_set_disconnect_callback(struct sock_client_context *sockc,
+					 sock_client_callback_func_t callback,
+					 void *private_data);
+
+/**
+ * @brief Async computation to send data to the daemon
+ *
+ * @param[in] mem_ctx Talloc memory context
+ * @param[in] ev Tevent context
+ * @param[in] sockc The socket client context
+ * @param[in] timeout How long to wait for
+ * @param[in] request Request packet to be sent
+ * @return new tevent request, or NULL on failure
+ */
+struct tevent_req *sock_client_msg_send(TALLOC_CTX *mem_ctx,
+					struct tevent_context *ev,
+					struct sock_client_context *sockc,
+					struct timeval timeout,
+					void *request);
+
+/**
+ * @brief Async computation end to send data to the daemon
+ *
+ * @param[in] req Tevent request
+ * @param[out] perr errno in case of failure
+ * @param[in] mem_ctx Talloc memory context
+ * @param[out] reply Reply received from server
+ * @return true on success, false on failure
+ */
+bool sock_client_msg_recv(struct tevent_req *req, int *perr,
+			  TALLOC_CTX *mem_ctx, void *reply);
+
+#endif /* __CTDB_SOCK_CLIENT_H__ */