1 /*
2 * Copyright (C) 2006 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef __CUTILS_SOCKETS_H
18 #define __CUTILS_SOCKETS_H
19
20 #include <errno.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <stdbool.h>
24
25 #ifdef HAVE_WINSOCK
26 #include <winsock2.h>
27 typedef int socklen_t;
28 #elif HAVE_SYS_SOCKET_H
29 #include <sys/socket.h>
30 #endif
31
32 #define ANDROID_SOCKET_ENV_PREFIX "ANDROID_SOCKET_"
33 #define ANDROID_SOCKET_DIR "/dev/socket"
34
35 #ifdef __cplusplus
36 extern "C" {
37 #endif
38
39 /*
40 * android_get_control_socket - simple helper function to get the file
41 * descriptor of our init-managed Unix domain socket. `name' is the name of the
42 * socket, as given in init.rc. Returns -1 on error.
43 *
44 * This is inline and not in libcutils proper because we want to use this in
45 * third-party daemons with minimal modification.
46 */
android_get_control_socket(const char * name)47 static inline int android_get_control_socket(const char *name)
48 {
49 char key[64] = ANDROID_SOCKET_ENV_PREFIX;
50 const char *val;
51 int fd;
52
53 /* build our environment variable, counting cycles like a wolf ... */
54 #if HAVE_STRLCPY
55 strlcpy(key + sizeof(ANDROID_SOCKET_ENV_PREFIX) - 1,
56 name,
57 sizeof(key) - sizeof(ANDROID_SOCKET_ENV_PREFIX));
58 #else /* for the host, which may lack the almightly strncpy ... */
59 strncpy(key + sizeof(ANDROID_SOCKET_ENV_PREFIX) - 1,
60 name,
61 sizeof(key) - sizeof(ANDROID_SOCKET_ENV_PREFIX));
62 key[sizeof(key)-1] = '\0';
63 #endif
64
65 val = getenv(key);
66 if (!val)
67 return -1;
68
69 errno = 0;
70 fd = strtol(val, NULL, 10);
71 if (errno)
72 return -1;
73
74 return fd;
75 }
76
77 /*
78 * See also android.os.LocalSocketAddress.Namespace
79 */
80 // Linux "abstract" (non-filesystem) namespace
81 #define ANDROID_SOCKET_NAMESPACE_ABSTRACT 0
82 // Android "reserved" (/dev/socket) namespace
83 #define ANDROID_SOCKET_NAMESPACE_RESERVED 1
84 // Normal filesystem namespace
85 #define ANDROID_SOCKET_NAMESPACE_FILESYSTEM 2
86
87 extern int socket_loopback_client(int port, int type);
88 extern int socket_network_client(const char *host, int port, int type);
89 extern int socket_loopback_server(int port, int type);
90 extern int socket_local_server(const char *name, int namespaceId, int type);
91 extern int socket_local_server_bind(int s, const char *name, int namespaceId);
92 extern int socket_local_client_connect(int fd,
93 const char *name, int namespaceId, int type);
94 extern int socket_local_client(const char *name, int namespaceId, int type);
95 extern int socket_inaddr_any_server(int port, int type);
96
97 /*
98 * socket_peer_is_trusted - Takes a socket which is presumed to be a
99 * connected local socket (e.g. AF_LOCAL) and returns whether the peer
100 * (the userid that owns the process on the other end of that socket)
101 * is one of the two trusted userids, root or shell.
102 *
103 * Note: This only works as advertised on the Android OS and always
104 * just returns true when called on other operating systems.
105 */
106 extern bool socket_peer_is_trusted(int fd);
107
108 #ifdef __cplusplus
109 }
110 #endif
111
112 #endif /* __CUTILS_SOCKETS_H */
113