1 /****************************************************************************** 2 * 3 * Copyright (C) 2014 Google, Inc. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at: 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 ******************************************************************************/ 18 19 #pragma once 20 21 #include <stdbool.h> 22 #include <stddef.h> 23 #include <stdint.h> 24 #include <sys/types.h> 25 26 typedef struct reactor_t reactor_t; 27 typedef struct socket_t socket_t; 28 typedef uint16_t port_t; 29 30 typedef void (*socket_cb)(socket_t *socket, void *context); 31 32 // Returns a new socket object. The socket is in an idle, disconnected state when 33 // it is returned by this function. The returned object must be freed by calling 34 // |socket_free|. Returns NULL on failure. 35 socket_t *socket_new(void); 36 37 // Returns a new socket object backed by |fd|. The socket object is in whichever 38 // state |fd| is in when it was passed to this function. The returned object must 39 // be freed by calling |socket_free|. Returns NULL on failure. If this function 40 // is successful, ownership of |fd| is transferred and the caller must not close it. 41 socket_t *socket_new_from_fd(int fd); 42 43 // Frees a socket object created by |socket_new| or |socket_accept|. |socket| may 44 // be NULL. If the socket was connected, it will be disconnected. 45 void socket_free(socket_t *socket); 46 47 // Puts |socket| in listening mode for incoming TCP connections on the specified 48 // |port| and the loopback IPv4 address. Returns true on success, false on 49 // failure (e.g. |port| is bound by another socket). |socket| may not be NULL. 50 bool socket_listen(const socket_t *socket, port_t port); 51 52 // Blocks on a listening socket, |socket|, until a client connects to it. Returns 53 // a connected socket on success, NULL on failure. The returned object must be 54 // freed by calling |socket_free|. |socket| may not be NULL. 55 socket_t *socket_accept(const socket_t *socket); 56 57 // Reads up to |count| bytes from |socket| into |buf|. This function will not 58 // block. This function returns a positive integer representing the number 59 // of bytes copied into |buf| on success, 0 if the socket has disconnected, 60 // and -1 on error. This function may return a value less than |count| if not 61 // enough data is currently available. If this function returns -1, errno will 62 // also be set (see recv(2) for possible errno values). However, if the reading 63 // system call was interrupted with errno of EINTR, the read operation is 64 // restarted internally without propagating EINTR back to the caller. If there 65 // were no bytes available to be read, this function returns -1 and sets errno 66 // to EWOULDBLOCK. Neither |socket| nor |buf| may be NULL. 67 ssize_t socket_read(const socket_t *socket, void *buf, size_t count); 68 69 // Writes up to |count| bytes from |buf| into |socket|. This function will not 70 // block. Returns a positive integer representing the number of bytes written 71 // to |socket| on success, 0 if the socket has disconnected, and -1 on error. 72 // This function may return a value less than |count| if writing more bytes 73 // would result in blocking. If this function returns -1, errno will also be 74 // set (see send(2) for possible errno values). However, if the writing system 75 // call was interrupted with errno of EINTR, the write operation is restarted 76 // internally without propagating EINTR back to the caller. If no bytes could 77 // be written without blocking, this function will return -1 and set errno to 78 // EWOULDBLOCK. Neither |socket| nor |buf| may be NULL. 79 ssize_t socket_write(const socket_t *socket, const void *buf, size_t count); 80 81 // This function performs the same write operation as |socket_write| and also 82 // sends the file descriptor |fd| over the socket to a remote process. Ownership 83 // of |fd| transfers to this function and the descriptor must not be used any longer. 84 // If |fd| is INVALID_FD, this function behaves the same as |socket_write|. 85 ssize_t socket_write_and_transfer_fd(const socket_t *socket, const void *buf, size_t count, int fd); 86 87 // Returns the number of bytes that can be read from |socket| without blocking. On error, 88 // this function returns -1. |socket| may not be NULL. 89 // 90 // Note: this function should not be part of the socket interface. It is only provided as 91 // a stop-gap until we can refactor away code that depends on a priori knowledge of 92 // the byte count. Do not use this function unless you need it while refactoring 93 // legacy bluedroid code. 94 ssize_t socket_bytes_available(const socket_t *socket); 95 96 // Registers |socket| with the |reactor|. When the socket becomes readable, |read_cb| 97 // will be called. When the socket becomes writeable, |write_cb| will be called. The 98 // |context| parameter is passed, untouched, to each of the callback routines. Neither 99 // |socket| nor |reactor| may be NULL. |read_cb|, |write_cb|, and |context| may be NULL. 100 void socket_register(socket_t *socket, reactor_t *reactor, void *context, socket_cb read_cb, socket_cb write_cb); 101 102 // Unregisters |socket| from whichever reactor it is registered with, if any. This 103 // function is idempotent. 104 void socket_unregister(socket_t *socket); 105