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/*
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 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 Requeset 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__ */
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