1 /* libs/cutils/socket_local_server.c
2 **
3 ** Copyright 2006, The Android Open Source Project
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 #include <cutils/sockets.h>
19 
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23 #include <errno.h>
24 #include <stddef.h>
25 
26 #if defined(_WIN32)
27 
socket_local_server(const char * name,int namespaceId,int type)28 int socket_local_server(const char *name, int namespaceId, int type)
29 {
30     errno = ENOSYS;
31     return -1;
32 }
33 
34 #else /* !_WIN32 */
35 
36 #include <sys/socket.h>
37 #include <sys/un.h>
38 #include <sys/select.h>
39 #include <sys/types.h>
40 #include <netinet/in.h>
41 
42 #include "socket_local_unix.h"
43 
44 #define LISTEN_BACKLOG 4
45 
46 /* Only the bottom bits are really the socket type; there are flags too. */
47 #define SOCK_TYPE_MASK 0xf
48 
49 /**
50  * Binds a pre-created socket(AF_LOCAL) 's' to 'name'
51  * returns 's' on success, -1 on fail
52  *
53  * Does not call listen()
54  */
socket_local_server_bind(int s,const char * name,int namespaceId)55 int socket_local_server_bind(int s, const char *name, int namespaceId)
56 {
57     struct sockaddr_un addr;
58     socklen_t alen;
59     int n;
60     int err;
61 
62     err = socket_make_sockaddr_un(name, namespaceId, &addr, &alen);
63 
64     if (err < 0) {
65         return -1;
66     }
67 
68     /* basically: if this is a filesystem path, unlink first */
69 #if !defined(__linux__)
70     if (1) {
71 #else
72     if (namespaceId == ANDROID_SOCKET_NAMESPACE_RESERVED
73         || namespaceId == ANDROID_SOCKET_NAMESPACE_FILESYSTEM) {
74 #endif
75         /*ignore ENOENT*/
76         unlink(addr.sun_path);
77     }
78 
79     n = 1;
80     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &n, sizeof(n));
81 
82     if(bind(s, (struct sockaddr *) &addr, alen) < 0) {
83         return -1;
84     }
85 
86     return s;
87 
88 }
89 
90 
91 /** Open a server-side UNIX domain datagram socket in the Linux non-filesystem
92  *  namespace
93  *
94  *  Returns fd on success, -1 on fail
95  */
96 
97 int socket_local_server(const char *name, int namespace, int type)
98 {
99     int err;
100     int s;
101 
102     s = socket(AF_LOCAL, type, 0);
103     if (s < 0) return -1;
104 
105     err = socket_local_server_bind(s, name, namespace);
106 
107     if (err < 0) {
108         close(s);
109         return -1;
110     }
111 
112     if ((type & SOCK_TYPE_MASK) == SOCK_STREAM) {
113         int ret;
114 
115         ret = listen(s, LISTEN_BACKLOG);
116 
117         if (ret < 0) {
118             close(s);
119             return -1;
120         }
121     }
122 
123     return s;
124 }
125 
126 #endif /* !_WIN32 */
127