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 <cutils/sockets.h>
18 
19 #include <errno.h>
20 #include <stddef.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24 
25 #if defined(_WIN32)
26 
socket_local_client(const char * name,int namespaceId,int type)27 int socket_local_client(const char *name, int namespaceId, int type)
28 {
29     errno = ENOSYS;
30     return -1;
31 }
32 
33 #else /* !_WIN32 */
34 
35 #include <sys/socket.h>
36 #include <sys/un.h>
37 #include <sys/select.h>
38 #include <sys/types.h>
39 
40 #include "socket_local_unix.h"
41 
42 #define LISTEN_BACKLOG 4
43 
44 /* Documented in header file. */
socket_make_sockaddr_un(const char * name,int namespaceId,struct sockaddr_un * p_addr,socklen_t * alen)45 int socket_make_sockaddr_un(const char *name, int namespaceId,
46         struct sockaddr_un *p_addr, socklen_t *alen)
47 {
48     memset (p_addr, 0, sizeof (*p_addr));
49     size_t namelen;
50 
51     switch (namespaceId) {
52         case ANDROID_SOCKET_NAMESPACE_ABSTRACT:
53 #if defined(__linux__)
54             namelen  = strlen(name);
55 
56             // Test with length +1 for the *initial* '\0'.
57             if ((namelen + 1) > sizeof(p_addr->sun_path)) {
58                 goto error;
59             }
60 
61             /*
62              * Note: The path in this case is *not* supposed to be
63              * '\0'-terminated. ("man 7 unix" for the gory details.)
64              */
65 
66             p_addr->sun_path[0] = 0;
67             memcpy(p_addr->sun_path + 1, name, namelen);
68 #else
69             /* this OS doesn't have the Linux abstract namespace */
70 
71             namelen = strlen(name) + strlen(FILESYSTEM_SOCKET_PREFIX);
72             /* unix_path_max appears to be missing on linux */
73             if (namelen > sizeof(*p_addr)
74                     - offsetof(struct sockaddr_un, sun_path) - 1) {
75                 goto error;
76             }
77 
78             strcpy(p_addr->sun_path, FILESYSTEM_SOCKET_PREFIX);
79             strcat(p_addr->sun_path, name);
80 #endif
81         break;
82 
83         case ANDROID_SOCKET_NAMESPACE_RESERVED:
84             namelen = strlen(name) + strlen(ANDROID_RESERVED_SOCKET_PREFIX);
85             /* unix_path_max appears to be missing on linux */
86             if (namelen > sizeof(*p_addr)
87                     - offsetof(struct sockaddr_un, sun_path) - 1) {
88                 goto error;
89             }
90 
91             strcpy(p_addr->sun_path, ANDROID_RESERVED_SOCKET_PREFIX);
92             strcat(p_addr->sun_path, name);
93         break;
94 
95         case ANDROID_SOCKET_NAMESPACE_FILESYSTEM:
96             namelen = strlen(name);
97             /* unix_path_max appears to be missing on linux */
98             if (namelen > sizeof(*p_addr)
99                     - offsetof(struct sockaddr_un, sun_path) - 1) {
100                 goto error;
101             }
102 
103             strcpy(p_addr->sun_path, name);
104         break;
105         default:
106             // invalid namespace id
107             return -1;
108     }
109 
110     p_addr->sun_family = AF_LOCAL;
111     *alen = namelen + offsetof(struct sockaddr_un, sun_path) + 1;
112     return 0;
113 error:
114     return -1;
115 }
116 
117 /**
118  * connect to peer named "name" on fd
119  * returns same fd or -1 on error.
120  * fd is not closed on error. that's your job.
121  *
122  * Used by AndroidSocketImpl
123  */
socket_local_client_connect(int fd,const char * name,int namespaceId,int)124 int socket_local_client_connect(int fd, const char* name, int namespaceId, int /*type*/) {
125     struct sockaddr_un addr;
126     socklen_t alen;
127     int err;
128 
129     err = socket_make_sockaddr_un(name, namespaceId, &addr, &alen);
130 
131     if (err < 0) {
132         goto error;
133     }
134 
135     if(connect(fd, (struct sockaddr *) &addr, alen) < 0) {
136         goto error;
137     }
138 
139     return fd;
140 
141 error:
142     return -1;
143 }
144 
145 /**
146  * connect to peer named "name"
147  * returns fd or -1 on error
148  */
socket_local_client(const char * name,int namespaceId,int type)149 int socket_local_client(const char *name, int namespaceId, int type)
150 {
151     int s;
152 
153     s = socket(AF_LOCAL, type, 0);
154     if(s < 0) return -1;
155 
156     if ( 0 > socket_local_client_connect(s, name, namespaceId, type)) {
157         close(s);
158         return -1;
159     }
160 
161     return s;
162 }
163 
164 #endif /* !_WIN32 */
165