roots.cpp - android_bootable_recovery - Gitiles

 /*
  * Copyright (C) 2007 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 <errno.h>
 #include <stdlib.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <ctype.h>

 extern "C" {
 #include "mtdutils/mtdutils.h"
 #include "mtdutils/mounts.h"
 }
 #include "roots.h"
 #include "common.h"
 #include "make_ext4fs.h"

 static int num_volumes = 0;
 static Volume* device_volumes = NULL;

 extern struct selabel_handle *sehandle;

 static int parse_options(char* options, Volume* volume) {
     char* option;
     while ((option = strtok(options, ","))) {
         options = NULL;

         if (strncmp(option, "length=", 7) == 0) {
             volume->length = strtoll(option+7, NULL, 10);
         } else {
             LOGE("bad option \"%s\"\n", option);
             return -1;
         }
     }
     return 0;
 }

 void load_volume_table() {
     int alloc = 2;
     device_volumes = (Volume*)malloc(alloc * sizeof(Volume));

     // Insert an entry for /tmp, which is the ramdisk and is always mounted.
     device_volumes[0].mount_point = "/tmp";
     device_volumes[0].fs_type = "ramdisk";
     device_volumes[0].device = NULL;
     device_volumes[0].device2 = NULL;
     device_volumes[0].length = 0;
     num_volumes = 1;

     FILE* fstab = fopen("/etc/recovery.fstab", "r");
     if (fstab == NULL) {
         LOGE("failed to open /etc/recovery.fstab (%s)\n", strerror(errno));
         return;
     }

     char buffer[1024];
     int i;
     while (fgets(buffer, sizeof(buffer)-1, fstab)) {
         for (i = 0; buffer[i] && isspace(buffer[i]); ++i);
         if (buffer[i] == '\0' || buffer[i] == '#') continue;

         char* original = strdup(buffer);

         char* mount_point = strtok(buffer+i, " \t\n");
         char* fs_type = strtok(NULL, " \t\n");
         char* device = strtok(NULL, " \t\n");
         // lines may optionally have a second device, to use if
         // mounting the first one fails.
         char* options = NULL;
         char* device2 = strtok(NULL, " \t\n");
         if (device2) {
             if (device2[0] == '/') {
                 options = strtok(NULL, " \t\n");
             } else {
                 options = device2;
                 device2 = NULL;
             }
         }

         if (mount_point && fs_type && device) {
             while (num_volumes >= alloc) {
                 alloc *= 2;
                 device_volumes = (Volume*)realloc(device_volumes, alloc*sizeof(Volume));
             }
             device_volumes[num_volumes].mount_point = strdup(mount_point);
             device_volumes[num_volumes].fs_type = strdup(fs_type);
             device_volumes[num_volumes].device = strdup(device);
             device_volumes[num_volumes].device2 =
                 device2 ? strdup(device2) : NULL;

             device_volumes[num_volumes].length = 0;
             if (parse_options(options, device_volumes + num_volumes) != 0) {
                 LOGE("skipping malformed recovery.fstab line: %s\n", original);
             } else {
                 ++num_volumes;
             }
         } else {
             LOGE("skipping malformed recovery.fstab line: %s\n", original);
         }
         free(original);
     }

     fclose(fstab);

     printf("recovery filesystem table\n");
     printf("=========================\n");
     for (i = 0; i < num_volumes; ++i) {
         Volume* v = &device_volumes[i];
         printf("  %d %s %s %s %s %lld\n", i, v->mount_point, v->fs_type,
                v->device, v->device2, v->length);
     }
     printf("\n");
 }

 Volume* volume_for_path(const char* path) {
     int i;
     for (i = 0; i < num_volumes; ++i) {
         Volume* v = device_volumes+i;
         int len = strlen(v->mount_point);
         if (strncmp(path, v->mount_point, len) == 0 &&
             (path[len] == '\0' || path[len] == '/')) {
             return v;
         }
     }
     return NULL;
 }

 int ensure_path_mounted(const char* path) {
     Volume* v = volume_for_path(path);
     if (v == NULL) {
         LOGE("unknown volume for path [%s]\n", path);
         return -1;
     }
     if (strcmp(v->fs_type, "ramdisk") == 0) {
         // the ramdisk is always mounted.
         return 0;
     }

     int result;
     result = scan_mounted_volumes();
     if (result < 0) {
         LOGE("failed to scan mounted volumes\n");
         return -1;
     }

     const MountedVolume* mv =
         find_mounted_volume_by_mount_point(v->mount_point);
     if (mv) {
         // volume is already mounted
         return 0;
     }

     mkdir(v->mount_point, 0755);  // in case it doesn't already exist

     if (strcmp(v->fs_type, "yaffs2") == 0) {
         // mount an MTD partition as a YAFFS2 filesystem.
         mtd_scan_partitions();
         const MtdPartition* partition;
         partition = mtd_find_partition_by_name(v->device);
         if (partition == NULL) {
             LOGE("failed to find \"%s\" partition to mount at \"%s\"\n",
                  v->device, v->mount_point);
             return -1;
         }
         return mtd_mount_partition(partition, v->mount_point, v->fs_type, 0);
     } else if (strcmp(v->fs_type, "ext4") == 0 ||
                strcmp(v->fs_type, "vfat") == 0) {
         result = mount(v->device, v->mount_point, v->fs_type,
                        MS_NOATIME | MS_NODEV | MS_NODIRATIME, "");
         if (result == 0) return 0;

         if (v->device2) {
             LOGW("failed to mount %s (%s); trying %s\n",
                  v->device, strerror(errno), v->device2);
             result = mount(v->device2, v->mount_point, v->fs_type,
                            MS_NOATIME | MS_NODEV | MS_NODIRATIME, "");
             if (result == 0) return 0;
         }

         LOGE("failed to mount %s (%s)\n", v->mount_point, strerror(errno));
         return -1;
     }

     LOGE("unknown fs_type \"%s\" for %s\n", v->fs_type, v->mount_point);
     return -1;
 }

 int ensure_path_unmounted(const char* path) {
     Volume* v = volume_for_path(path);
     if (v == NULL) {
         LOGE("unknown volume for path [%s]\n", path);
         return -1;
     }
     if (strcmp(v->fs_type, "ramdisk") == 0) {
         // the ramdisk is always mounted; you can't unmount it.
         return -1;
     }

     int result;
     result = scan_mounted_volumes();
     if (result < 0) {
         LOGE("failed to scan mounted volumes\n");
         return -1;
     }

     const MountedVolume* mv =
         find_mounted_volume_by_mount_point(v->mount_point);
     if (mv == NULL) {
         // volume is already unmounted
         return 0;
     }

     return unmount_mounted_volume(mv);
 }

 int format_volume(const char* volume) {
     Volume* v = volume_for_path(volume);
     if (v == NULL) {
         LOGE("unknown volume \"%s\"\n", volume);
         return -1;
     }
     if (strcmp(v->fs_type, "ramdisk") == 0) {
         // you can't format the ramdisk.
         LOGE("can't format_volume \"%s\"", volume);
         return -1;
     }
     if (strcmp(v->mount_point, volume) != 0) {
         LOGE("can't give path \"%s\" to format_volume\n", volume);
         return -1;
     }

     if (ensure_path_unmounted(volume) != 0) {
         LOGE("format_volume failed to unmount \"%s\"\n", v->mount_point);
         return -1;
     }

     if (strcmp(v->fs_type, "yaffs2") == 0 || strcmp(v->fs_type, "mtd") == 0) {
         mtd_scan_partitions();
         const MtdPartition* partition = mtd_find_partition_by_name(v->device);
         if (partition == NULL) {
             LOGE("format_volume: no MTD partition \"%s\"\n", v->device);
             return -1;
         }

         MtdWriteContext *write = mtd_write_partition(partition);
         if (write == NULL) {
             LOGW("format_volume: can't open MTD \"%s\"\n", v->device);
             return -1;
         } else if (mtd_erase_blocks(write, -1) == (off_t) -1) {
             LOGW("format_volume: can't erase MTD \"%s\"\n", v->device);
             mtd_write_close(write);
             return -1;
         } else if (mtd_write_close(write)) {
             LOGW("format_volume: can't close MTD \"%s\"\n", v->device);
             return -1;
         }
         return 0;
     }

     if (strcmp(v->fs_type, "ext4") == 0) {
         int result = make_ext4fs(v->device, v->length, volume, sehandle);
         if (result != 0) {
             LOGE("format_volume: make_extf4fs failed on %s\n", v->device);
             return -1;
         }
         return 0;
     }

     LOGE("format_volume: fs_type \"%s\" unsupported\n", v->fs_type);
     return -1;
 }
	/*
	* Copyright (C) 2007 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 <errno.h>
	#include <stdlib.h>
	#include <sys/mount.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <unistd.h>
	#include <ctype.h>

	extern "C" {
	#include "mtdutils/mtdutils.h"
	#include "mtdutils/mounts.h"
	}
	#include "roots.h"
	#include "common.h"
	#include "make_ext4fs.h"

	static int num_volumes = 0;
	static Volume* device_volumes = NULL;

	extern struct selabel_handle *sehandle;

	static int parse_options(char* options, Volume* volume) {
	char* option;
	while ((option = strtok(options, ","))) {
	options = NULL;

	if (strncmp(option, "length=", 7) == 0) {
	volume->length = strtoll(option+7, NULL, 10);
	} else {
	LOGE("bad option \"%s\"\n", option);
	return -1;
	}
	}
	return 0;
	}

	void load_volume_table() {
	int alloc = 2;
	device_volumes = (Volume)malloc(alloc sizeof(Volume));

	// Insert an entry for /tmp, which is the ramdisk and is always mounted.
	device_volumes[0].mount_point = "/tmp";
	device_volumes[0].fs_type = "ramdisk";
	device_volumes[0].device = NULL;
	device_volumes[0].device2 = NULL;
	device_volumes[0].length = 0;
	num_volumes = 1;

	FILE* fstab = fopen("/etc/recovery.fstab", "r");
	if (fstab == NULL) {
	LOGE("failed to open /etc/recovery.fstab (%s)\n", strerror(errno));
	return;
	}

	char buffer[1024];
	int i;
	while (fgets(buffer, sizeof(buffer)-1, fstab)) {
	for (i = 0; buffer[i] && isspace(buffer[i]); ++i);
	if (buffer[i] == '\0' \|\| buffer[i] == '#') continue;

	char* original = strdup(buffer);

	char* mount_point = strtok(buffer+i, " \t\n");
	char* fs_type = strtok(NULL, " \t\n");
	char* device = strtok(NULL, " \t\n");
	// lines may optionally have a second device, to use if
	// mounting the first one fails.
	char* options = NULL;
	char* device2 = strtok(NULL, " \t\n");
	if (device2) {
	if (device2[0] == '/') {
	options = strtok(NULL, " \t\n");
	} else {
	options = device2;
	device2 = NULL;
	}
	}

	if (mount_point && fs_type && device) {
	while (num_volumes >= alloc) {
	alloc *= 2;
	device_volumes = (Volume)realloc(device_volumes, allocsizeof(Volume));
	}
	device_volumes[num_volumes].mount_point = strdup(mount_point);
	device_volumes[num_volumes].fs_type = strdup(fs_type);
	device_volumes[num_volumes].device = strdup(device);
	device_volumes[num_volumes].device2 =
	device2 ? strdup(device2) : NULL;

	device_volumes[num_volumes].length = 0;
	if (parse_options(options, device_volumes + num_volumes) != 0) {
	LOGE("skipping malformed recovery.fstab line: %s\n", original);
	} else {
	++num_volumes;
	}
	} else {
	LOGE("skipping malformed recovery.fstab line: %s\n", original);
	}
	free(original);
	}

	fclose(fstab);

	printf("recovery filesystem table\n");
	printf("=========================\n");
	for (i = 0; i < num_volumes; ++i) {
	Volume* v = &device_volumes[i];
	printf(" %d %s %s %s %s %lld\n", i, v->mount_point, v->fs_type,
	v->device, v->device2, v->length);
	}
	printf("\n");
	}

	Volume* volume_for_path(const char* path) {
	int i;
	for (i = 0; i < num_volumes; ++i) {
	Volume* v = device_volumes+i;
	int len = strlen(v->mount_point);
	if (strncmp(path, v->mount_point, len) == 0 &&
	(path[len] == '\0' \|\| path[len] == '/')) {
	return v;
	}
	}
	return NULL;
	}

	int ensure_path_mounted(const char* path) {
	Volume* v = volume_for_path(path);
	if (v == NULL) {
	LOGE("unknown volume for path [%s]\n", path);
	return -1;
	}
	if (strcmp(v->fs_type, "ramdisk") == 0) {
	// the ramdisk is always mounted.
	return 0;
	}

	int result;
	result = scan_mounted_volumes();
	if (result < 0) {
	LOGE("failed to scan mounted volumes\n");
	return -1;
	}

	const MountedVolume* mv =
	find_mounted_volume_by_mount_point(v->mount_point);
	if (mv) {
	// volume is already mounted
	return 0;
	}

	mkdir(v->mount_point, 0755); // in case it doesn't already exist

	if (strcmp(v->fs_type, "yaffs2") == 0) {
	// mount an MTD partition as a YAFFS2 filesystem.
	mtd_scan_partitions();
	const MtdPartition* partition;
	partition = mtd_find_partition_by_name(v->device);
	if (partition == NULL) {
	LOGE("failed to find \"%s\" partition to mount at \"%s\"\n",
	v->device, v->mount_point);
	return -1;
	}
	return mtd_mount_partition(partition, v->mount_point, v->fs_type, 0);
	} else if (strcmp(v->fs_type, "ext4") == 0 \|\|
	strcmp(v->fs_type, "vfat") == 0) {
	result = mount(v->device, v->mount_point, v->fs_type,
	MS_NOATIME \| MS_NODEV \| MS_NODIRATIME, "");
	if (result == 0) return 0;

	if (v->device2) {
	LOGW("failed to mount %s (%s); trying %s\n",
	v->device, strerror(errno), v->device2);
	result = mount(v->device2, v->mount_point, v->fs_type,
	MS_NOATIME \| MS_NODEV \| MS_NODIRATIME, "");
	if (result == 0) return 0;
	}

	LOGE("failed to mount %s (%s)\n", v->mount_point, strerror(errno));
	return -1;
	}

	LOGE("unknown fs_type \"%s\" for %s\n", v->fs_type, v->mount_point);
	return -1;
	}

	int ensure_path_unmounted(const char* path) {
	Volume* v = volume_for_path(path);
	if (v == NULL) {
	LOGE("unknown volume for path [%s]\n", path);
	return -1;
	}
	if (strcmp(v->fs_type, "ramdisk") == 0) {
	// the ramdisk is always mounted; you can't unmount it.
	return -1;
	}

	int result;
	result = scan_mounted_volumes();
	if (result < 0) {
	LOGE("failed to scan mounted volumes\n");
	return -1;
	}

	const MountedVolume* mv =
	find_mounted_volume_by_mount_point(v->mount_point);
	if (mv == NULL) {
	// volume is already unmounted
	return 0;
	}

	return unmount_mounted_volume(mv);
	}

	int format_volume(const char* volume) {
	Volume* v = volume_for_path(volume);
	if (v == NULL) {
	LOGE("unknown volume \"%s\"\n", volume);
	return -1;
	}
	if (strcmp(v->fs_type, "ramdisk") == 0) {
	// you can't format the ramdisk.
	LOGE("can't format_volume \"%s\"", volume);
	return -1;
	}
	if (strcmp(v->mount_point, volume) != 0) {
	LOGE("can't give path \"%s\" to format_volume\n", volume);
	return -1;
	}

	if (ensure_path_unmounted(volume) != 0) {
	LOGE("format_volume failed to unmount \"%s\"\n", v->mount_point);
	return -1;
	}

	if (strcmp(v->fs_type, "yaffs2") == 0 \|\| strcmp(v->fs_type, "mtd") == 0) {
	mtd_scan_partitions();
	const MtdPartition* partition = mtd_find_partition_by_name(v->device);
	if (partition == NULL) {
	LOGE("format_volume: no MTD partition \"%s\"\n", v->device);
	return -1;
	}

	MtdWriteContext *write = mtd_write_partition(partition);
	if (write == NULL) {
	LOGW("format_volume: can't open MTD \"%s\"\n", v->device);
	return -1;
	} else if (mtd_erase_blocks(write, -1) == (off_t) -1) {
	LOGW("format_volume: can't erase MTD \"%s\"\n", v->device);
	mtd_write_close(write);
	return -1;
	} else if (mtd_write_close(write)) {
	LOGW("format_volume: can't close MTD \"%s\"\n", v->device);
	return -1;
	}
	return 0;
	}

	if (strcmp(v->fs_type, "ext4") == 0) {
	int result = make_ext4fs(v->device, v->length, volume, sehandle);
	if (result != 0) {
	LOGE("format_volume: make_extf4fs failed on %s\n", v->device);
	return -1;
	}
	return 0;
	}

	LOGE("format_volume: fs_type \"%s\" unsupported\n", v->fs_type);
	return -1;
	}