Loop.cpp - SHIFTPHONES/android_system_vold - Gitiles

 /*
  * 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 <stdio.h>
 #include <stdlib.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
 #include <string.h>

 #include <sys/mount.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>

 #include <linux/kdev_t.h>

 #define LOG_TAG "Vold"

 #include <cutils/log.h>

 #include <sysutils/SocketClient.h>
 #include "Loop.h"
 #include "Asec.h"
 #include "sehandle.h"

 int Loop::dumpState(SocketClient *c) {
     int i;
     int fd;
     char filename[256];

     for (i = 0; i < LOOP_MAX; i++) {
         struct loop_info64 li;
         int rc;

         sprintf(filename, "/dev/block/loop%d", i);

         if ((fd = open(filename, O_RDWR)) < 0) {
             if (errno != ENOENT) {
                 SLOGE("Unable to open %s (%s)", filename, strerror(errno));
             } else {
                 continue;
             }
             return -1;
         }

         rc = ioctl(fd, LOOP_GET_STATUS64, &li);
         close(fd);
         if (rc < 0 && errno == ENXIO) {
             continue;
         }

         if (rc < 0) {
             SLOGE("Unable to get loop status for %s (%s)", filename,
                  strerror(errno));
             return -1;
         }
         char *tmp = NULL;
         asprintf(&tmp, "%s %d %lld:%lld %llu %lld:%lld %lld 0x%x {%s} {%s}", filename, li.lo_number,
                 MAJOR(li.lo_device), MINOR(li.lo_device), li.lo_inode, MAJOR(li.lo_rdevice),
                         MINOR(li.lo_rdevice), li.lo_offset, li.lo_flags, li.lo_crypt_name,
                         li.lo_file_name);
         c->sendMsg(0, tmp, false);
         free(tmp);
     }
     return 0;
 }

 int Loop::lookupActive(const char *id, char *buffer, size_t len) {
     int i;
     int fd;
     char filename[256];

     memset(buffer, 0, len);

     for (i = 0; i < LOOP_MAX; i++) {
         struct loop_info64 li;
         int rc;

         sprintf(filename, "/dev/block/loop%d", i);

         if ((fd = open(filename, O_RDWR)) < 0) {
             if (errno != ENOENT) {
                 SLOGE("Unable to open %s (%s)", filename, strerror(errno));
             } else {
                 continue;
             }
             return -1;
         }

         rc = ioctl(fd, LOOP_GET_STATUS64, &li);
         close(fd);
         if (rc < 0 && errno == ENXIO) {
             continue;
         }

         if (rc < 0) {
             SLOGE("Unable to get loop status for %s (%s)", filename,
                  strerror(errno));
             return -1;
         }
         if (!strncmp((const char*) li.lo_crypt_name, id, LO_NAME_SIZE)) {
             break;
         }
     }

     if (i == LOOP_MAX) {
         errno = ENOENT;
         return -1;
     }
     strlcpy(buffer, filename, len);
     return 0;
 }

 int Loop::create(const char *id, const char *loopFile, char *loopDeviceBuffer, size_t len) {
     int i;
     int fd;
     char filename[256];

     for (i = 0; i < LOOP_MAX; i++) {
         struct loop_info64 li;
         int rc;
         char *secontext = NULL;

         sprintf(filename, "/dev/block/loop%d", i);

         /*
          * The kernel starts us off with 8 loop nodes, but more
          * are created on-demand if needed.
          */
         mode_t mode = 0660 | S_IFBLK;
         unsigned int dev = (0xff & i) | ((i << 12) & 0xfff00000) | (7 << 8);

         if (sehandle) {
             rc = selabel_lookup(sehandle, &secontext, filename, S_IFBLK);
             if (rc == 0)
                 setfscreatecon(secontext);
         }

         if (mknod(filename, mode, dev) < 0) {
             if (errno != EEXIST) {
                 int sverrno = errno;
                 SLOGE("Error creating loop device node (%s)", strerror(errno));
                 if (secontext) {
                     freecon(secontext);
                     setfscreatecon(NULL);
                 }
                 errno = sverrno;
                 return -1;
             }
         }
         if (secontext) {
             freecon(secontext);
             setfscreatecon(NULL);
         }

         if ((fd = open(filename, O_RDWR)) < 0) {
             SLOGE("Unable to open %s (%s)", filename, strerror(errno));
             return -1;
         }

         rc = ioctl(fd, LOOP_GET_STATUS64, &li);
         if (rc < 0 && errno == ENXIO)
             break;

         close(fd);

         if (rc < 0) {
             SLOGE("Unable to get loop status for %s (%s)", filename,
                  strerror(errno));
             return -1;
         }
     }

     if (i == LOOP_MAX) {
         SLOGE("Exhausted all loop devices");
         errno = ENOSPC;
         return -1;
     }

     strlcpy(loopDeviceBuffer, filename, len);

     int file_fd;

     if ((file_fd = open(loopFile, O_RDWR)) < 0) {
         SLOGE("Unable to open %s (%s)", loopFile, strerror(errno));
         close(fd);
         return -1;
     }

     if (ioctl(fd, LOOP_SET_FD, file_fd) < 0) {
         SLOGE("Error setting up loopback interface (%s)", strerror(errno));
         close(file_fd);
         close(fd);
         return -1;
     }

     struct loop_info64 li;

     memset(&li, 0, sizeof(li));
     strlcpy((char*) li.lo_crypt_name, id, LO_NAME_SIZE);
     strlcpy((char*) li.lo_file_name, loopFile, LO_NAME_SIZE);

     if (ioctl(fd, LOOP_SET_STATUS64, &li) < 0) {
         SLOGE("Error setting loopback status (%s)", strerror(errno));
         close(file_fd);
         close(fd);
         return -1;
     }

     close(fd);
     close(file_fd);

     return 0;
 }

 int Loop::destroyByDevice(const char *loopDevice) {
     int device_fd;

     device_fd = open(loopDevice, O_RDONLY);
     if (device_fd < 0) {
         SLOGE("Failed to open loop (%d)", errno);
         return -1;
     }

     if (ioctl(device_fd, LOOP_CLR_FD, 0) < 0) {
         SLOGE("Failed to destroy loop (%d)", errno);
         close(device_fd);
         return -1;
     }

     close(device_fd);
     return 0;
 }

 int Loop::destroyByFile(const char * /*loopFile*/) {
     errno = ENOSYS;
     return -1;
 }

 int Loop::createImageFile(const char *file, unsigned int numSectors) {
     int fd;

     if ((fd = creat(file, 0600)) < 0) {
         SLOGE("Error creating imagefile (%s)", strerror(errno));
         return -1;
     }

     if (ftruncate(fd, numSectors * 512) < 0) {
         SLOGE("Error truncating imagefile (%s)", strerror(errno));
         close(fd);
         return -1;
     }
     close(fd);
     return 0;
 }

 int Loop::resizeImageFile(const char *file, unsigned int numSectors) {
     int fd;

     if ((fd = open(file, O_RDWR)) < 0) {
         SLOGE("Error opening imagefile (%s)", strerror(errno));
         return -1;
     }

     SLOGD("Attempting to increase size of %s to %d sectors.", file, numSectors);

     if (fallocate(fd, 0, 0, numSectors * 512)) {
         if (errno == ENOSYS || errno == ENOTSUP) {
             SLOGW("fallocate not found. Falling back to ftruncate.");
             if (ftruncate(fd, numSectors * 512) < 0) {
                 SLOGE("Error truncating imagefile (%s)", strerror(errno));
                 close(fd);
                 return -1;
             }
         } else {
             SLOGE("Error allocating space (%s)", strerror(errno));
             close(fd);
             return -1;
         }
     }
     close(fd);
     return 0;
 }

 int Loop::lookupInfo(const char *loopDevice, struct asec_superblock *sb, unsigned int *nr_sec) {
     int fd;
     struct asec_superblock buffer;

     if ((fd = open(loopDevice, O_RDONLY)) < 0) {
         SLOGE("Failed to open loopdevice (%s)", strerror(errno));
         destroyByDevice(loopDevice);
         return -1;
     }

     if (ioctl(fd, BLKGETSIZE, nr_sec)) {
         SLOGE("Failed to get loop size (%s)", strerror(errno));
         destroyByDevice(loopDevice);
         close(fd);
         return -1;
     }

     /*
      * Try to read superblock.
      */
     memset(&buffer, 0, sizeof(struct asec_superblock));
     if (lseek(fd, ((*nr_sec - 1) * 512), SEEK_SET) < 0) {
         SLOGE("lseek failed (%s)", strerror(errno));
         close(fd);
         destroyByDevice(loopDevice);
         return -1;
     }
     if (read(fd, &buffer, sizeof(struct asec_superblock)) != sizeof(struct asec_superblock)) {
         SLOGE("superblock read failed (%s)", strerror(errno));
         close(fd);
         destroyByDevice(loopDevice);
         return -1;
     }
     close(fd);

     /*
      * Superblock successfully read. Copy to caller's struct.
      */
     memcpy(sb, &buffer, sizeof(struct asec_superblock));
     return 0;
 }
	/*
	* 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 <stdio.h>
	#include <stdlib.h>
	#include <fcntl.h>
	#include <unistd.h>
	#include <errno.h>
	#include <string.h>

	#include <sys/mount.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/ioctl.h>

	#include <linux/kdev_t.h>

	#define LOG_TAG "Vold"

	#include <cutils/log.h>

	#include <sysutils/SocketClient.h>
	#include "Loop.h"
	#include "Asec.h"
	#include "sehandle.h"

	int Loop::dumpState(SocketClient *c) {
	int i;
	int fd;
	char filename[256];

	for (i = 0; i < LOOP_MAX; i++) {
	struct loop_info64 li;
	int rc;

	sprintf(filename, "/dev/block/loop%d", i);

	if ((fd = open(filename, O_RDWR)) < 0) {
	if (errno != ENOENT) {
	SLOGE("Unable to open %s (%s)", filename, strerror(errno));
	} else {
	continue;
	}
	return -1;
	}

	rc = ioctl(fd, LOOP_GET_STATUS64, &li);
	close(fd);
	if (rc < 0 && errno == ENXIO) {
	continue;
	}

	if (rc < 0) {
	SLOGE("Unable to get loop status for %s (%s)", filename,
	strerror(errno));
	return -1;
	}
	char *tmp = NULL;
	asprintf(&tmp, "%s %d %lld:%lld %llu %lld:%lld %lld 0x%x {%s} {%s}", filename, li.lo_number,
	MAJOR(li.lo_device), MINOR(li.lo_device), li.lo_inode, MAJOR(li.lo_rdevice),
	MINOR(li.lo_rdevice), li.lo_offset, li.lo_flags, li.lo_crypt_name,
	li.lo_file_name);
	c->sendMsg(0, tmp, false);
	free(tmp);
	}
	return 0;
	}

	int Loop::lookupActive(const char id, char buffer, size_t len) {
	int i;
	int fd;
	char filename[256];

	memset(buffer, 0, len);

	for (i = 0; i < LOOP_MAX; i++) {
	struct loop_info64 li;
	int rc;

	sprintf(filename, "/dev/block/loop%d", i);

	if ((fd = open(filename, O_RDWR)) < 0) {
	if (errno != ENOENT) {
	SLOGE("Unable to open %s (%s)", filename, strerror(errno));
	} else {
	continue;
	}
	return -1;
	}

	rc = ioctl(fd, LOOP_GET_STATUS64, &li);
	close(fd);
	if (rc < 0 && errno == ENXIO) {
	continue;
	}

	if (rc < 0) {
	SLOGE("Unable to get loop status for %s (%s)", filename,
	strerror(errno));
	return -1;
	}
	if (!strncmp((const char*) li.lo_crypt_name, id, LO_NAME_SIZE)) {
	break;
	}
	}

	if (i == LOOP_MAX) {
	errno = ENOENT;
	return -1;
	}
	strlcpy(buffer, filename, len);
	return 0;
	}

	int Loop::create(const char id, const char loopFile, char *loopDeviceBuffer, size_t len) {
	int i;
	int fd;
	char filename[256];

	for (i = 0; i < LOOP_MAX; i++) {
	struct loop_info64 li;
	int rc;
	char *secontext = NULL;

	sprintf(filename, "/dev/block/loop%d", i);

	/*
	* The kernel starts us off with 8 loop nodes, but more
	* are created on-demand if needed.
	*/
	mode_t mode = 0660 \| S_IFBLK;
	unsigned int dev = (0xff & i) \| ((i << 12) & 0xfff00000) \| (7 << 8);

	if (sehandle) {
	rc = selabel_lookup(sehandle, &secontext, filename, S_IFBLK);
	if (rc == 0)
	setfscreatecon(secontext);
	}

	if (mknod(filename, mode, dev) < 0) {
	if (errno != EEXIST) {
	int sverrno = errno;
	SLOGE("Error creating loop device node (%s)", strerror(errno));
	if (secontext) {
	freecon(secontext);
	setfscreatecon(NULL);
	}
	errno = sverrno;
	return -1;
	}
	}
	if (secontext) {
	freecon(secontext);
	setfscreatecon(NULL);
	}

	if ((fd = open(filename, O_RDWR)) < 0) {
	SLOGE("Unable to open %s (%s)", filename, strerror(errno));
	return -1;
	}

	rc = ioctl(fd, LOOP_GET_STATUS64, &li);
	if (rc < 0 && errno == ENXIO)
	break;

	close(fd);

	if (rc < 0) {
	SLOGE("Unable to get loop status for %s (%s)", filename,
	strerror(errno));
	return -1;
	}
	}

	if (i == LOOP_MAX) {
	SLOGE("Exhausted all loop devices");
	errno = ENOSPC;
	return -1;
	}

	strlcpy(loopDeviceBuffer, filename, len);

	int file_fd;

	if ((file_fd = open(loopFile, O_RDWR)) < 0) {
	SLOGE("Unable to open %s (%s)", loopFile, strerror(errno));
	close(fd);
	return -1;
	}

	if (ioctl(fd, LOOP_SET_FD, file_fd) < 0) {
	SLOGE("Error setting up loopback interface (%s)", strerror(errno));
	close(file_fd);
	close(fd);
	return -1;
	}

	struct loop_info64 li;

	memset(&li, 0, sizeof(li));
	strlcpy((char*) li.lo_crypt_name, id, LO_NAME_SIZE);
	strlcpy((char*) li.lo_file_name, loopFile, LO_NAME_SIZE);

	if (ioctl(fd, LOOP_SET_STATUS64, &li) < 0) {
	SLOGE("Error setting loopback status (%s)", strerror(errno));
	close(file_fd);
	close(fd);
	return -1;
	}

	close(fd);
	close(file_fd);

	return 0;
	}

	int Loop::destroyByDevice(const char *loopDevice) {
	int device_fd;

	device_fd = open(loopDevice, O_RDONLY);
	if (device_fd < 0) {
	SLOGE("Failed to open loop (%d)", errno);
	return -1;
	}

	if (ioctl(device_fd, LOOP_CLR_FD, 0) < 0) {
	SLOGE("Failed to destroy loop (%d)", errno);
	close(device_fd);
	return -1;
	}

	close(device_fd);
	return 0;
	}

	int Loop::destroyByFile(const char * /loopFile/) {
	errno = ENOSYS;
	return -1;
	}

	int Loop::createImageFile(const char *file, unsigned int numSectors) {
	int fd;

	if ((fd = creat(file, 0600)) < 0) {
	SLOGE("Error creating imagefile (%s)", strerror(errno));
	return -1;
	}

	if (ftruncate(fd, numSectors * 512) < 0) {
	SLOGE("Error truncating imagefile (%s)", strerror(errno));
	close(fd);
	return -1;
	}
	close(fd);
	return 0;
	}

	int Loop::resizeImageFile(const char *file, unsigned int numSectors) {
	int fd;

	if ((fd = open(file, O_RDWR)) < 0) {
	SLOGE("Error opening imagefile (%s)", strerror(errno));
	return -1;
	}

	SLOGD("Attempting to increase size of %s to %d sectors.", file, numSectors);

	if (fallocate(fd, 0, 0, numSectors * 512)) {
	if (errno == ENOSYS \|\| errno == ENOTSUP) {
	SLOGW("fallocate not found. Falling back to ftruncate.");
	if (ftruncate(fd, numSectors * 512) < 0) {
	SLOGE("Error truncating imagefile (%s)", strerror(errno));
	close(fd);
	return -1;
	}
	} else {
	SLOGE("Error allocating space (%s)", strerror(errno));
	close(fd);
	return -1;
	}
	}
	close(fd);
	return 0;
	}

	int Loop::lookupInfo(const char loopDevice, struct asec_superblock sb, unsigned int *nr_sec) {
	int fd;
	struct asec_superblock buffer;

	if ((fd = open(loopDevice, O_RDONLY)) < 0) {
	SLOGE("Failed to open loopdevice (%s)", strerror(errno));
	destroyByDevice(loopDevice);
	return -1;
	}

	if (ioctl(fd, BLKGETSIZE, nr_sec)) {
	SLOGE("Failed to get loop size (%s)", strerror(errno));
	destroyByDevice(loopDevice);
	close(fd);
	return -1;
	}

	/*
	* Try to read superblock.
	*/
	memset(&buffer, 0, sizeof(struct asec_superblock));
	if (lseek(fd, ((nr_sec - 1) 512), SEEK_SET) < 0) {
	SLOGE("lseek failed (%s)", strerror(errno));
	close(fd);
	destroyByDevice(loopDevice);
	return -1;
	}
	if (read(fd, &buffer, sizeof(struct asec_superblock)) != sizeof(struct asec_superblock)) {
	SLOGE("superblock read failed (%s)", strerror(errno));
	close(fd);
	destroyByDevice(loopDevice);
	return -1;
	}
	close(fd);

	/*
	* Superblock successfully read. Copy to caller's struct.
	*/
	memcpy(sb, &buffer, sizeof(struct asec_superblock));
	return 0;
	}