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      1 /*
      2  * Copyright (C) 2009 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 /* this program is used to read a set of system properties and their values
     18  * from the emulator program and set them in the currently-running emulated
     19  * system. It does so by connecting to the 'boot-properties' qemud service.
     20  *
     21  * This program should be run as root and called from
     22  * /system/etc/init.goldfish.rc exclusively.
     23  */
     24 
     25 #define LOG_TAG  "qemu-props"
     26 
     27 #define DEBUG  1
     28 
     29 #if DEBUG
     30 #  include <cutils/log.h>
     31 #  define  DD(...)    LOGI(__VA_ARGS__)
     32 #else
     33 #  define  DD(...)    ((void)0)
     34 #endif
     35 
     36 #include <cutils/properties.h>
     37 #include <unistd.h>
     38 #include <hardware/qemud.h>
     39 
     40 /* Name of the qemud service we want to connect to.
     41  */
     42 #define  QEMUD_SERVICE  "boot-properties"
     43 
     44 #define  MAX_TRIES      5
     45 
     46 int  main(void)
     47 {
     48     int  qemud_fd, count = 0;
     49 
     50     /* try to connect to the qemud service */
     51     {
     52         int  tries = MAX_TRIES;
     53 
     54         while (1) {
     55             qemud_fd = qemud_channel_open( "boot-properties" );
     56             if (qemud_fd >= 0)
     57                 break;
     58 
     59             if (--tries <= 0) {
     60                 DD("Could not connect after too many tries. Aborting");
     61                 return 1;
     62             }
     63 
     64             DD("waiting 1s to wait for qemud.");
     65             sleep(1);
     66         }
     67     }
     68 
     69     DD("connected to '%s' qemud service.", QEMUD_SERVICE);
     70 
     71     /* send the 'list' command to the service */
     72     if (qemud_channel_send(qemud_fd, "list", -1) < 0) {
     73         DD("could not send command to '%s' service", QEMUD_SERVICE);
     74         return 1;
     75     }
     76 
     77     /* read each system property as a single line from the service,
     78      * until exhaustion.
     79      */
     80     for (;;)
     81     {
     82 #define  BUFF_SIZE   (PROPERTY_KEY_MAX + PROPERTY_VALUE_MAX + 2)
     83         DD("receiving..");
     84         char* q;
     85         char  temp[BUFF_SIZE];
     86         int   len = qemud_channel_recv(qemud_fd, temp, sizeof temp - 1);
     87 
     88         /* lone NUL-byte signals end of properties */
     89         if (len < 0 || len > BUFF_SIZE-1 || temp[0] == '\0')
     90             break;
     91 
     92         temp[len] = '\0';  /* zero-terminate string */
     93 
     94         DD("received: %.*s", len, temp);
     95 
     96         /* separate propery name from value */
     97         q = strchr(temp, '=');
     98         if (q == NULL) {
     99             DD("invalid format, ignored.");
    100             continue;
    101         }
    102         *q++ = '\0';
    103 
    104         if (property_set(temp, q) < 0) {
    105             DD("could not set property '%s' to '%s'", temp, q);
    106         } else {
    107             count += 1;
    108         }
    109     }
    110 
    111 
    112     /* finally, close the channel and exit */
    113     close(qemud_fd);
    114     DD("exiting (%d properties set).", count);
    115     return 0;
    116 }
    117