1 // Copyright 2018 Espressif Systems (Shanghai) PTE LTD 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 /** 16 * \file ctrl_sock.h 17 * \brief Control Socket for select() wakeup 18 * 19 * LWIP doesn't allow an easy mechanism to on-demand wakeup a thread 20 * sleeping on select. This is a common requirement for sending 21 * control commands to a network server. This control socket API 22 * facilitates the same. 23 */ 24 #ifndef _CTRL_SOCK_H_ 25 #define _CTRL_SOCK_H_ 26 27 #ifdef __cplusplus 28 extern "C" { 29 #endif 30 31 /** 32 * @brief Create a control socket 33 * 34 * LWIP doesn't allow an easy mechanism to on-demand wakeup a thread 35 * sleeping on select. This is a common requirement for sending 36 * control commands to a network server. This control socket API 37 * facilitates the same. 38 * 39 * This API will create a UDP control socket on the specified port. It 40 * will return a socket descriptor that can then be added to your 41 * fd_set in select() 42 * 43 * @param[in] port the local port on which the control socket will listen 44 * 45 * @return - the socket descriptor that can be added to the fd_set in select. 46 * - an error code if less than zero 47 */ 48 int cs_create_ctrl_sock(int port); 49 50 /** 51 * @brief Free the control socket 52 * 53 * This frees up the control socket that was earlier created using 54 * cs_create_ctrl_sock() 55 * 56 * @param[in] fd the socket descriptor associated with this control socket 57 */ 58 void cs_free_ctrl_sock(int fd); 59 60 /** 61 * @brief Send data to control socket 62 * 63 * This API sends data to the control socket. If a server is blocked 64 * on select() with the control socket, this call will wake up that 65 * server. 66 * 67 * @param[in] send_fd the socket for sending ctrl messages 68 * @param[in] port the port on which the control socket was created 69 * @param[in] data pointer to a buffer that contains data to send on the socket 70 * @param[in] data_len the length of the data contained in the buffer pointed to be data 71 * 72 * @return - the number of bytes sent to the control socket 73 * - an error code if less than zero 74 */ 75 int cs_send_to_ctrl_sock(int send_fd, int port, void *data, unsigned int data_len); 76 77 /** 78 * @brief Receive data from control socket 79 * 80 * This API receives any data that was sent to the control 81 * socket. This will be typically called from the server thread to 82 * process any commands on this socket. 83 * 84 * @param[in] fd the socket descriptor of the control socket 85 * @param[in] data pointer to a buffer that will be used to store 86 * received from the control socket 87 * @param[in] data_len the maximum length of the data that can be 88 * stored in the buffer pointed by data 89 * 90 * @return - the number of bytes received from the control socket 91 * - an error code if less than zero 92 */ 93 int cs_recv_from_ctrl_sock(int fd, void *data, unsigned int data_len); 94 95 #ifdef __cplusplus 96 } 97 #endif 98 99 #endif /* ! _CTRL_SOCK_H_ */ 100
