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