/*
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* Copyright (C) 2008 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <string.h>
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#include <fcntl.h>
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#include <sys/mount.h>
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#include <errno.h>
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#include "sysdeps.h"
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#define TRACE_TAG TRACE_ADB
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#include "adb.h"
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static int system_ro = 1;
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/* Returns the device used to mount a directory in /proc/mounts */
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static char *find_mount(const char *dir)
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{
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int fd;
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int res;
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int size;
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char *token = NULL;
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const char delims[] = "\n";
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char buf[4096];
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fd = unix_open("/proc/mounts", O_RDONLY);
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if (fd < 0)
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return NULL;
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buf[sizeof(buf) - 1] = '\0';
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size = adb_read(fd, buf, sizeof(buf) - 1);
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adb_close(fd);
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token = strtok(buf, delims);
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while (token) {
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char mount_dev[256];
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char mount_dir[256];
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int mount_freq;
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int mount_passno;
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res = sscanf(token, "%255s %255s %*s %*s %d %d\n",
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mount_dev, mount_dir, &mount_freq, &mount_passno);
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mount_dev[255] = 0;
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mount_dir[255] = 0;
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if (res == 4 && (strcmp(dir, mount_dir) == 0))
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return strdup(mount_dev);
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token = strtok(NULL, delims);
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}
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return NULL;
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}
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/* Init mounts /system as read only, remount to enable writes. */
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static int remount_system()
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{
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char *dev;
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if (system_ro == 0) {
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return 0;
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}
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dev = find_mount("/system");
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if (!dev)
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return -1;
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system_ro = mount(dev, "/system", "none", MS_REMOUNT, NULL);
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free(dev);
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return system_ro;
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}
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static void write_string(int fd, const char* str)
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{
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writex(fd, str, strlen(str));
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}
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void remount_service(int fd, void *cookie)
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{
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int ret = remount_system();
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if (!ret)
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write_string(fd, "remount succeeded\n");
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else {
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char buffer[200];
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snprintf(buffer, sizeof(buffer), "remount failed: %s\n", strerror(errno));
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write_string(fd, buffer);
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}
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adb_close(fd);
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}
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