Files
esp-idf/components/esp_http_server/src/util/ctrl_sock.h

92 lines
2.9 KiB
C

/*
* SPDX-FileCopyrightText: 2018-2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* \file ctrl_sock.h
* \brief Control Socket for select() wakeup
*
* LWIP doesn't allow an easy mechanism to on-demand wakeup a thread
* sleeping on select. This is a common requirement for sending
* control commands to a network server. This control socket API
* facilitates the same.
*/
#ifndef _CTRL_SOCK_H_
#define _CTRL_SOCK_H_
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Create a control socket
*
* LWIP doesn't allow an easy mechanism to on-demand wakeup a thread
* sleeping on select. This is a common requirement for sending
* control commands to a network server. This control socket API
* facilitates the same.
*
* This API will create a UDP control socket on the specified port. It
* will return a socket descriptor that can then be added to your
* fd_set in select()
*
* @param[in] port the local port on which the control socket will listen
*
* @return - the socket descriptor that can be added to the fd_set in select.
* - an error code if less than zero
*/
int cs_create_ctrl_sock(int port);
/**
* @brief Free the control socket
*
* This frees up the control socket that was earlier created using
* cs_create_ctrl_sock()
*
* @param[in] fd the socket descriptor associated with this control socket
*/
void cs_free_ctrl_sock(int fd);
/**
* @brief Send data to control socket
*
* This API sends data to the control socket. If a server is blocked
* on select() with the control socket, this call will wake up that
* server.
*
* @param[in] send_fd the socket for sending ctrl messages
* @param[in] port the port on which the control socket was created
* @param[in] data pointer to a buffer that contains data to send on the socket
* @param[in] data_len the length of the data contained in the buffer pointed to be data
*
* @return - the number of bytes sent to the control socket
* - an error code if less than zero
*/
int cs_send_to_ctrl_sock(int send_fd, int port, void *data, unsigned int data_len);
/**
* @brief Receive data from control socket
*
* This API receives any data that was sent to the control
* socket. This will be typically called from the server thread to
* process any commands on this socket.
*
* @param[in] fd the socket descriptor of the control socket
* @param[in] data pointer to a buffer that will be used to store
* received from the control socket
* @param[in] data_len the maximum length of the data that can be
* stored in the buffer pointed by data
*
* @return - the number of bytes received from the control socket
* - an error code if less than zero
*/
int cs_recv_from_ctrl_sock(int fd, void *data, unsigned int data_len);
#ifdef __cplusplus
}
#endif
#endif /* ! _CTRL_SOCK_H_ */