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      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 <stddef.h>
     19 #include <stdlib.h>
     20 #include <string.h>
     21 #include <unistd.h>
     22 
     23 #include <cutils/sockets.h>
     24 
     25 #if defined(_WIN32)
     26 
     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 UNUSED __attribute__((unused))
     43 
     44 #define LISTEN_BACKLOG 4
     45 
     46 /* Documented in header file. */
     47 int socket_make_sockaddr_un(const char *name, int namespaceId,
     48         struct sockaddr_un *p_addr, socklen_t *alen)
     49 {
     50     memset (p_addr, 0, sizeof (*p_addr));
     51     size_t namelen;
     52 
     53     switch (namespaceId) {
     54         case ANDROID_SOCKET_NAMESPACE_ABSTRACT:
     55 #if defined(__linux__)
     56             namelen  = strlen(name);
     57 
     58             // Test with length +1 for the *initial* '\0'.
     59             if ((namelen + 1) > sizeof(p_addr->sun_path)) {
     60                 goto error;
     61             }
     62 
     63             /*
     64              * Note: The path in this case is *not* supposed to be
     65              * '\0'-terminated. ("man 7 unix" for the gory details.)
     66              */
     67 
     68             p_addr->sun_path[0] = 0;
     69             memcpy(p_addr->sun_path + 1, name, namelen);
     70 #else
     71             /* this OS doesn't have the Linux abstract namespace */
     72 
     73             namelen = strlen(name) + strlen(FILESYSTEM_SOCKET_PREFIX);
     74             /* unix_path_max appears to be missing on linux */
     75             if (namelen > sizeof(*p_addr)
     76                     - offsetof(struct sockaddr_un, sun_path) - 1) {
     77                 goto error;
     78             }
     79 
     80             strcpy(p_addr->sun_path, FILESYSTEM_SOCKET_PREFIX);
     81             strcat(p_addr->sun_path, name);
     82 #endif
     83         break;
     84 
     85         case ANDROID_SOCKET_NAMESPACE_RESERVED:
     86             namelen = strlen(name) + strlen(ANDROID_RESERVED_SOCKET_PREFIX);
     87             /* unix_path_max appears to be missing on linux */
     88             if (namelen > sizeof(*p_addr)
     89                     - offsetof(struct sockaddr_un, sun_path) - 1) {
     90                 goto error;
     91             }
     92 
     93             strcpy(p_addr->sun_path, ANDROID_RESERVED_SOCKET_PREFIX);
     94             strcat(p_addr->sun_path, name);
     95         break;
     96 
     97         case ANDROID_SOCKET_NAMESPACE_FILESYSTEM:
     98             namelen = strlen(name);
     99             /* unix_path_max appears to be missing on linux */
    100             if (namelen > sizeof(*p_addr)
    101                     - offsetof(struct sockaddr_un, sun_path) - 1) {
    102                 goto error;
    103             }
    104 
    105             strcpy(p_addr->sun_path, name);
    106         break;
    107         default:
    108             // invalid namespace id
    109             return -1;
    110     }
    111 
    112     p_addr->sun_family = AF_LOCAL;
    113     *alen = namelen + offsetof(struct sockaddr_un, sun_path) + 1;
    114     return 0;
    115 error:
    116     return -1;
    117 }
    118 
    119 /**
    120  * connect to peer named "name" on fd
    121  * returns same fd or -1 on error.
    122  * fd is not closed on error. that's your job.
    123  *
    124  * Used by AndroidSocketImpl
    125  */
    126 int socket_local_client_connect(int fd, const char *name, int namespaceId,
    127         int type UNUSED)
    128 {
    129     struct sockaddr_un addr;
    130     socklen_t alen;
    131     int err;
    132 
    133     err = socket_make_sockaddr_un(name, namespaceId, &addr, &alen);
    134 
    135     if (err < 0) {
    136         goto error;
    137     }
    138 
    139     if(connect(fd, (struct sockaddr *) &addr, alen) < 0) {
    140         goto error;
    141     }
    142 
    143     return fd;
    144 
    145 error:
    146     return -1;
    147 }
    148 
    149 /**
    150  * connect to peer named "name"
    151  * returns fd or -1 on error
    152  */
    153 int socket_local_client(const char *name, int namespaceId, int type)
    154 {
    155     int s;
    156 
    157     s = socket(AF_LOCAL, type, 0);
    158     if(s < 0) return -1;
    159 
    160     if ( 0 > socket_local_client_connect(s, name, namespaceId, type)) {
    161         close(s);
    162         return -1;
    163     }
    164 
    165     return s;
    166 }
    167 
    168 #endif /* !_WIN32 */
    169