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/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __CUTILS_SOCKETS_H
#define __CUTILS_SOCKETS_H
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#if defined(_WIN32)
#include <winsock2.h>
#include <ws2tcpip.h>
typedef int socklen_t;
typedef SOCKET cutils_socket_t;
#else
#include <sys/socket.h>
typedef int cutils_socket_t;
#define INVALID_SOCKET (-1)
#endif
#define ANDROID_SOCKET_ENV_PREFIX "ANDROID_SOCKET_"
#define ANDROID_SOCKET_DIR "/dev/socket"
#ifdef __cplusplus
extern "C" {
#endif
/*
* android_get_control_socket - simple helper function to get the file
* descriptor of our init-managed Unix domain socket. `name' is the name of the
* socket, as given in init.rc. Returns -1 on error.
*
* This is inline and not in libcutils proper because we want to use this in
* third-party daemons with minimal modification.
*/
static inline int android_get_control_socket(const char* name)
{
char key[64];
snprintf(key, sizeof(key), ANDROID_SOCKET_ENV_PREFIX "%s", name);
const char* val = getenv(key);
if (!val) {
return -1;
}
errno = 0;
int fd = strtol(val, NULL, 10);
if (errno) {
return -1;
}
return fd;
}
/*
* See also android.os.LocalSocketAddress.Namespace
*/
// Linux "abstract" (non-filesystem) namespace
#define ANDROID_SOCKET_NAMESPACE_ABSTRACT 0
// Android "reserved" (/dev/socket) namespace
#define ANDROID_SOCKET_NAMESPACE_RESERVED 1
// Normal filesystem namespace
#define ANDROID_SOCKET_NAMESPACE_FILESYSTEM 2
/*
* Functions to create sockets for some common usages.
*
* All these functions are implemented for Unix, but only a few are implemented
* for Windows. Those which are can be identified by the cutils_socket_t
* return type. The idea is to be able to use this return value with the
* standard Unix socket functions on any platform.
*
* On Unix the returned cutils_socket_t is a standard int file descriptor and
* can always be used as normal with all file descriptor functions.
*
* On Windows utils_socket_t is an unsigned int pointer, and is only valid
* with functions that specifically take a socket, e.g. send(), sendto(),
* recv(), and recvfrom(). General file descriptor functions such as read(),
* write(), and close() will not work with utils_socket_t and will require
* special handling.
*
* These functions return INVALID_SOCKET (-1) on failure for all platforms.
*/
int socket_loopback_client(int port, int type);
cutils_socket_t socket_network_client(const char* host, int port, int type);
int socket_network_client_timeout(const char* host, int port, int type,
int timeout, int* getaddrinfo_error);
int socket_loopback_server(int port, int type);
int socket_local_server(const char* name, int namespaceId, int type);
int socket_local_server_bind(int s, const char* name, int namespaceId);
int socket_local_client_connect(int fd, const char *name, int namespaceId,
int type);
int socket_local_client(const char* name, int namespaceId, int type);
cutils_socket_t socket_inaddr_any_server(int port, int type);
/*
* Closes a cutils_socket_t. Windows doesn't allow calling close() on a socket
* so this is a cross-platform way to close a cutils_socket_t.
*
* Returns 0 on success.
*/
int socket_close(cutils_socket_t sock);
/*
* Sets socket receive timeout using SO_RCVTIMEO. Setting |timeout_ms| to 0
* disables receive timeouts.
*
* Return 0 on success.
*/
int socket_set_receive_timeout(cutils_socket_t sock, int timeout_ms);
/*
* Returns the local port the socket is bound to or -1 on error.
*/
int socket_get_local_port(cutils_socket_t sock);
/*
* Sends to a socket from multiple buffers; wraps writev() on Unix or WSASend()
* on Windows. This can give significant speedup compared to calling send()
* multiple times.
*
* Example usage:
* cutils_socket_buffer_t buffers[2] = { {data0, len0}, {data1, len1} };
* socket_send_buffers(sock, buffers, 2);
*
* If you try to pass more than SOCKET_SEND_BUFFERS_MAX_BUFFERS buffers into
* this function it will return -1 without sending anything.
*
* Returns the number of bytes written or -1 on error.
*/
typedef struct {
const void* data;
size_t length;
} cutils_socket_buffer_t;
#define SOCKET_SEND_BUFFERS_MAX_BUFFERS 16
ssize_t socket_send_buffers(cutils_socket_t sock,
const cutils_socket_buffer_t* buffers,
size_t num_buffers);
/*
* socket_peer_is_trusted - Takes a socket which is presumed to be a
* connected local socket (e.g. AF_LOCAL) and returns whether the peer
* (the userid that owns the process on the other end of that socket)
* is one of the two trusted userids, root or shell.
*
* Note: This only works as advertised on the Android OS and always
* just returns true when called on other operating systems.
*/
extern bool socket_peer_is_trusted(int fd);
#ifdef __cplusplus
}
#endif
#endif /* __CUTILS_SOCKETS_H */