socket_local_client.c revision dd7bc3319deb2b77c5d07a51b7d6cd7e11b5beb0 
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 <stdlib.h>
20#include <string.h>
21#include <unistd.h>
22#include <errno.h>
23#include <stddef.h>
24
25#ifdef HAVE_WINSOCK
26
27int socket_local_client(const char *name, int namespaceId, int type)
28{
29    errno = ENOSYS;
30    return -1;
31}
32
33#else /* !HAVE_WINSOCK */
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.h"
41
42#define LISTEN_BACKLOG 4
43
44/* Documented in header file. */
45int 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#ifdef HAVE_LINUX_LOCAL_SOCKET_NAMESPACE
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 /*HAVE_LINUX_LOCAL_SOCKET_NAMESPACE*/
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 /*HAVE_LINUX_LOCAL_SOCKET_NAMESPACE*/
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;
113error:
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 */
124int socket_local_client_connect(int fd, const char *name, int namespaceId,
125        int type)
126{
127    struct sockaddr_un addr;
128    socklen_t alen;
129    size_t namelen;
130    int err;
131
132    err = socket_make_sockaddr_un(name, namespaceId, &addr, &alen);
133
134    if (err < 0) {
135        goto error;
136    }
137
138    if(connect(fd, (struct sockaddr *) &addr, alen) < 0) {
139        goto error;
140    }
141
142    return fd;
143
144error:
145    return -1;
146}
147
148/**
149 * connect to peer named "name"
150 * returns fd or -1 on error
151 */
152int socket_local_client(const char *name, int namespaceId, int type)
153{
154    int s;
155
156    s = socket(AF_LOCAL, type, 0);
157    if(s < 0) return -1;
158
159    if ( 0 > socket_local_client_connect(s, name, namespaceId, type)) {
160        close(s);
161        return -1;
162    }
163
164    return s;
165}
166
167#endif /* !HAVE_WINSOCK */
168