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