Devmapper.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 <stdlib.h>

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

 #include <linux/kdev_t.h>

 #define LOG_TAG "Vold"

 #include <cutils/log.h>

 #include <android-base/logging.h>
 #include <android-base/stringprintf.h>

 #include "Devmapper.h"

 #define DEVMAPPER_BUFFER_SIZE 4096

 using android::base::StringPrintf;

 static const char* kVoldPrefix = "vold:";

 void Devmapper::ioctlInit(struct dm_ioctl *io, size_t dataSize,
                           const char *name, unsigned flags) {
     memset(io, 0, dataSize);
     io->data_size = dataSize;
     io->data_start = sizeof(struct dm_ioctl);
     io->version[0] = 4;
     io->version[1] = 0;
     io->version[2] = 0;
     io->flags = flags;
     if (name) {
         size_t ret = strlcpy(io->name, name, sizeof(io->name));
         if (ret >= sizeof(io->name))
             abort();
     }
 }

 int Devmapper::lookupActive(const char *name_raw, char *ubuffer, size_t len) {
     auto name_string = StringPrintf("%s%s", kVoldPrefix, name_raw);
     const char* name = name_string.c_str();

     char *buffer = (char *) malloc(DEVMAPPER_BUFFER_SIZE);
     if (!buffer) {
         SLOGE("Error allocating memory (%s)", strerror(errno));
         return -1;
     }

     int fd;
     if ((fd = open("/dev/device-mapper", O_RDWR | O_CLOEXEC)) < 0) {
         SLOGE("Error opening devmapper (%s)", strerror(errno));
         free(buffer);
         return -1;
     }

     struct dm_ioctl *io = (struct dm_ioctl *) buffer;

     ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);
     if (ioctl(fd, DM_DEV_STATUS, io)) {
         if (errno != ENXIO) {
             SLOGE("DM_DEV_STATUS ioctl failed for lookup (%s)", strerror(errno));
         }
         free(buffer);
         close(fd);
         return -1;
     }
     close(fd);

     unsigned minor = (io->dev & 0xff) | ((io->dev >> 12) & 0xfff00);
     free(buffer);
     snprintf(ubuffer, len, "/dev/block/dm-%u", minor);
     return 0;
 }

 int Devmapper::create(const char *name_raw, const char *loopFile, const char *key,
                       unsigned long numSectors, char *ubuffer, size_t len) {
     auto name_string = StringPrintf("%s%s", kVoldPrefix, name_raw);
     const char* name = name_string.c_str();

     char *buffer = (char *) malloc(DEVMAPPER_BUFFER_SIZE);
     if (!buffer) {
         SLOGE("Error allocating memory (%s)", strerror(errno));
         return -1;
     }

     int fd;
     if ((fd = open("/dev/device-mapper", O_RDWR | O_CLOEXEC)) < 0) {
         SLOGE("Error opening devmapper (%s)", strerror(errno));
         free(buffer);
         return -1;
     }

     struct dm_ioctl *io = (struct dm_ioctl *) buffer;

     // Create the DM device
     ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);

     if (ioctl(fd, DM_DEV_CREATE, io)) {
         SLOGE("Error creating device mapping (%s)", strerror(errno));
         free(buffer);
         close(fd);
         return -1;
     }

     // Set the legacy geometry
     ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);

     char *geoParams = buffer + sizeof(struct dm_ioctl);
     // bps=512 spc=8 res=32 nft=2 sec=8190 mid=0xf0 spt=63 hds=64 hid=0 bspf=8 rdcl=2 infs=1 bkbs=2
     strlcpy(geoParams, "0 64 63 0", DEVMAPPER_BUFFER_SIZE - sizeof(struct dm_ioctl));
     geoParams += strlen(geoParams) + 1;
     geoParams = (char *) _align(geoParams, 8);
     if (ioctl(fd, DM_DEV_SET_GEOMETRY, io)) {
         SLOGE("Error setting device geometry (%s)", strerror(errno));
         free(buffer);
         close(fd);
         return -1;
     }

     // Retrieve the device number we were allocated
     ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);
     if (ioctl(fd, DM_DEV_STATUS, io)) {
         SLOGE("Error retrieving devmapper status (%s)", strerror(errno));
         free(buffer);
         close(fd);
         return -1;
     }

     unsigned minor = (io->dev & 0xff) | ((io->dev >> 12) & 0xfff00);
     snprintf(ubuffer, len, "/dev/block/dm-%u", minor);

     // Load the table
     struct dm_target_spec *tgt;
     tgt = (struct dm_target_spec *) &buffer[sizeof(struct dm_ioctl)];

     ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, DM_STATUS_TABLE_FLAG);
     io->target_count = 1;
     tgt->status = 0;

     tgt->sector_start = 0;
     tgt->length = numSectors;

     strlcpy(tgt->target_type, "crypt", sizeof(tgt->target_type));

     char *cryptParams = buffer + sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec);
     snprintf(cryptParams,
             DEVMAPPER_BUFFER_SIZE - (sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec)),
             "twofish %s 0 %s 0", key, loopFile);
     cryptParams += strlen(cryptParams) + 1;
     cryptParams = (char *) _align(cryptParams, 8);
     tgt->next = cryptParams - buffer;

     if (ioctl(fd, DM_TABLE_LOAD, io)) {
         SLOGE("Error loading mapping table (%s)", strerror(errno));
         free(buffer);
         close(fd);
         return -1;
     }

     // Resume the new table
     ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);

     if (ioctl(fd, DM_DEV_SUSPEND, io)) {
         SLOGE("Error Resuming (%s)", strerror(errno));
         free(buffer);
         close(fd);
         return -1;
     }

     free(buffer);

     close(fd);
     return 0;
 }

 int Devmapper::destroy(const char *name_raw) {
     auto name_string = StringPrintf("%s%s", kVoldPrefix, name_raw);
     const char* name = name_string.c_str();

     char *buffer = (char *) malloc(DEVMAPPER_BUFFER_SIZE);
     if (!buffer) {
         SLOGE("Error allocating memory (%s)", strerror(errno));
         return -1;
     }

     int fd;
     if ((fd = open("/dev/device-mapper", O_RDWR | O_CLOEXEC)) < 0) {
         SLOGE("Error opening devmapper (%s)", strerror(errno));
         free(buffer);
         return -1;
     }

     struct dm_ioctl *io = (struct dm_ioctl *) buffer;

     // Create the DM device
     ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);

     if (ioctl(fd, DM_DEV_REMOVE, io)) {
         if (errno != ENXIO) {
             SLOGE("Error destroying device mapping (%s)", strerror(errno));
         }
         free(buffer);
         close(fd);
         return -1;
     }

     free(buffer);
     close(fd);
     return 0;
 }

 int Devmapper::destroyAll() {
     char *buffer = (char *) malloc(1024 * 64);
     if (!buffer) {
         SLOGE("Error allocating memory (%s)", strerror(errno));
         return -1;
     }
     memset(buffer, 0, (1024 * 64));

     char *buffer2 = (char *) malloc(DEVMAPPER_BUFFER_SIZE);
     if (!buffer2) {
         SLOGE("Error allocating memory (%s)", strerror(errno));
         free(buffer);
         return -1;
     }

     int fd;
     if ((fd = open("/dev/device-mapper", O_RDWR | O_CLOEXEC)) < 0) {
         SLOGE("Error opening devmapper (%s)", strerror(errno));
         free(buffer);
         free(buffer2);
         return -1;
     }

     struct dm_ioctl *io = (struct dm_ioctl *) buffer;
     ioctlInit(io, (1024 * 64), NULL, 0);

     if (ioctl(fd, DM_LIST_DEVICES, io)) {
         SLOGE("DM_LIST_DEVICES ioctl failed (%s)", strerror(errno));
         free(buffer);
         free(buffer2);
         close(fd);
         return -1;
     }

     struct dm_name_list *n = (struct dm_name_list *) (((char *) buffer) + io->data_start);
     if (!n->dev) {
         free(buffer);
         free(buffer2);
         close(fd);
         return 0;
     }

     unsigned nxt = 0;
     do {
         n = (struct dm_name_list *) (((char *) n) + nxt);
         if (strncmp(n->name, kVoldPrefix, strlen(kVoldPrefix)) == 0) {
             LOG(DEBUG) << "Tearing down stale dm device named " << n->name;

             memset(buffer2, 0, DEVMAPPER_BUFFER_SIZE);
             struct dm_ioctl *io2 = (struct dm_ioctl *) buffer2;
             ioctlInit(io2, DEVMAPPER_BUFFER_SIZE, n->name, 0);
             if (ioctl(fd, DM_DEV_REMOVE, io2)) {
                 if (errno != ENXIO) {
                     PLOG(WARNING) << "Failed to destroy dm device named " << n->name;
                 }
             }
         } else {
             LOG(VERBOSE) << "Found unmanaged dm device named " << n->name;
         }
         nxt = n->next;
     } while (nxt);

     free(buffer);
     free(buffer2);
     close(fd);
     return 0;
 }

 void *Devmapper::_align(void *ptr, unsigned int a)
 {
         unsigned long agn = --a;

         return (void *) (((unsigned long) ptr + agn) & ~agn);
 }
	/*
	* 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 <stdlib.h>

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

	#include <linux/kdev_t.h>

	#define LOG_TAG "Vold"

	#include <cutils/log.h>

	#include <android-base/logging.h>
	#include <android-base/stringprintf.h>

	#include "Devmapper.h"

	#define DEVMAPPER_BUFFER_SIZE 4096

	using android::base::StringPrintf;

	static const char* kVoldPrefix = "vold:";

	void Devmapper::ioctlInit(struct dm_ioctl *io, size_t dataSize,
	const char *name, unsigned flags) {
	memset(io, 0, dataSize);
	io->data_size = dataSize;
	io->data_start = sizeof(struct dm_ioctl);
	io->version[0] = 4;
	io->version[1] = 0;
	io->version[2] = 0;
	io->flags = flags;
	if (name) {
	size_t ret = strlcpy(io->name, name, sizeof(io->name));
	if (ret >= sizeof(io->name))
	abort();
	}
	}

	int Devmapper::lookupActive(const char name_raw, char ubuffer, size_t len) {
	auto name_string = StringPrintf("%s%s", kVoldPrefix, name_raw);
	const char* name = name_string.c_str();

	char buffer = (char ) malloc(DEVMAPPER_BUFFER_SIZE);
	if (!buffer) {
	SLOGE("Error allocating memory (%s)", strerror(errno));
	return -1;
	}

	int fd;
	if ((fd = open("/dev/device-mapper", O_RDWR \| O_CLOEXEC)) < 0) {
	SLOGE("Error opening devmapper (%s)", strerror(errno));
	free(buffer);
	return -1;
	}

	struct dm_ioctl io = (struct dm_ioctl ) buffer;

	ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);
	if (ioctl(fd, DM_DEV_STATUS, io)) {
	if (errno != ENXIO) {
	SLOGE("DM_DEV_STATUS ioctl failed for lookup (%s)", strerror(errno));
	}
	free(buffer);
	close(fd);
	return -1;
	}
	close(fd);

	unsigned minor = (io->dev & 0xff) \| ((io->dev >> 12) & 0xfff00);
	free(buffer);
	snprintf(ubuffer, len, "/dev/block/dm-%u", minor);
	return 0;
	}

	int Devmapper::create(const char name_raw, const char loopFile, const char *key,
	unsigned long numSectors, char *ubuffer, size_t len) {
	auto name_string = StringPrintf("%s%s", kVoldPrefix, name_raw);
	const char* name = name_string.c_str();

	char buffer = (char ) malloc(DEVMAPPER_BUFFER_SIZE);
	if (!buffer) {
	SLOGE("Error allocating memory (%s)", strerror(errno));
	return -1;
	}

	int fd;
	if ((fd = open("/dev/device-mapper", O_RDWR \| O_CLOEXEC)) < 0) {
	SLOGE("Error opening devmapper (%s)", strerror(errno));
	free(buffer);
	return -1;
	}

	struct dm_ioctl io = (struct dm_ioctl ) buffer;

	// Create the DM device
	ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);

	if (ioctl(fd, DM_DEV_CREATE, io)) {
	SLOGE("Error creating device mapping (%s)", strerror(errno));
	free(buffer);
	close(fd);
	return -1;
	}

	// Set the legacy geometry
	ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);

	char *geoParams = buffer + sizeof(struct dm_ioctl);
	// bps=512 spc=8 res=32 nft=2 sec=8190 mid=0xf0 spt=63 hds=64 hid=0 bspf=8 rdcl=2 infs=1 bkbs=2
	strlcpy(geoParams, "0 64 63 0", DEVMAPPER_BUFFER_SIZE - sizeof(struct dm_ioctl));
	geoParams += strlen(geoParams) + 1;
	geoParams = (char *) _align(geoParams, 8);
	if (ioctl(fd, DM_DEV_SET_GEOMETRY, io)) {
	SLOGE("Error setting device geometry (%s)", strerror(errno));
	free(buffer);
	close(fd);
	return -1;
	}

	// Retrieve the device number we were allocated
	ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);
	if (ioctl(fd, DM_DEV_STATUS, io)) {
	SLOGE("Error retrieving devmapper status (%s)", strerror(errno));
	free(buffer);
	close(fd);
	return -1;
	}

	unsigned minor = (io->dev & 0xff) \| ((io->dev >> 12) & 0xfff00);
	snprintf(ubuffer, len, "/dev/block/dm-%u", minor);

	// Load the table
	struct dm_target_spec *tgt;
	tgt = (struct dm_target_spec *) &buffer[sizeof(struct dm_ioctl)];

	ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, DM_STATUS_TABLE_FLAG);
	io->target_count = 1;
	tgt->status = 0;

	tgt->sector_start = 0;
	tgt->length = numSectors;

	strlcpy(tgt->target_type, "crypt", sizeof(tgt->target_type));

	char *cryptParams = buffer + sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec);
	snprintf(cryptParams,
	DEVMAPPER_BUFFER_SIZE - (sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec)),
	"twofish %s 0 %s 0", key, loopFile);
	cryptParams += strlen(cryptParams) + 1;
	cryptParams = (char *) _align(cryptParams, 8);
	tgt->next = cryptParams - buffer;

	if (ioctl(fd, DM_TABLE_LOAD, io)) {
	SLOGE("Error loading mapping table (%s)", strerror(errno));
	free(buffer);
	close(fd);
	return -1;
	}

	// Resume the new table
	ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);

	if (ioctl(fd, DM_DEV_SUSPEND, io)) {
	SLOGE("Error Resuming (%s)", strerror(errno));
	free(buffer);
	close(fd);
	return -1;
	}

	free(buffer);

	close(fd);
	return 0;
	}

	int Devmapper::destroy(const char *name_raw) {
	auto name_string = StringPrintf("%s%s", kVoldPrefix, name_raw);
	const char* name = name_string.c_str();

	char buffer = (char ) malloc(DEVMAPPER_BUFFER_SIZE);
	if (!buffer) {
	SLOGE("Error allocating memory (%s)", strerror(errno));
	return -1;
	}

	int fd;
	if ((fd = open("/dev/device-mapper", O_RDWR \| O_CLOEXEC)) < 0) {
	SLOGE("Error opening devmapper (%s)", strerror(errno));
	free(buffer);
	return -1;
	}

	struct dm_ioctl io = (struct dm_ioctl ) buffer;

	// Create the DM device
	ioctlInit(io, DEVMAPPER_BUFFER_SIZE, name, 0);

	if (ioctl(fd, DM_DEV_REMOVE, io)) {
	if (errno != ENXIO) {
	SLOGE("Error destroying device mapping (%s)", strerror(errno));
	}
	free(buffer);
	close(fd);
	return -1;
	}

	free(buffer);
	close(fd);
	return 0;
	}

	int Devmapper::destroyAll() {
	char buffer = (char ) malloc(1024 * 64);
	if (!buffer) {
	SLOGE("Error allocating memory (%s)", strerror(errno));
	return -1;
	}
	memset(buffer, 0, (1024 * 64));

	char buffer2 = (char ) malloc(DEVMAPPER_BUFFER_SIZE);
	if (!buffer2) {
	SLOGE("Error allocating memory (%s)", strerror(errno));
	free(buffer);
	return -1;
	}

	int fd;
	if ((fd = open("/dev/device-mapper", O_RDWR \| O_CLOEXEC)) < 0) {
	SLOGE("Error opening devmapper (%s)", strerror(errno));
	free(buffer);
	free(buffer2);
	return -1;
	}

	struct dm_ioctl io = (struct dm_ioctl ) buffer;
	ioctlInit(io, (1024 * 64), NULL, 0);

	if (ioctl(fd, DM_LIST_DEVICES, io)) {
	SLOGE("DM_LIST_DEVICES ioctl failed (%s)", strerror(errno));
	free(buffer);
	free(buffer2);
	close(fd);
	return -1;
	}

	struct dm_name_list n = (struct dm_name_list ) (((char *) buffer) + io->data_start);
	if (!n->dev) {
	free(buffer);
	free(buffer2);
	close(fd);
	return 0;
	}

	unsigned nxt = 0;
	do {
	n = (struct dm_name_list ) (((char ) n) + nxt);
	if (strncmp(n->name, kVoldPrefix, strlen(kVoldPrefix)) == 0) {
	LOG(DEBUG) << "Tearing down stale dm device named " << n->name;

	memset(buffer2, 0, DEVMAPPER_BUFFER_SIZE);
	struct dm_ioctl io2 = (struct dm_ioctl ) buffer2;
	ioctlInit(io2, DEVMAPPER_BUFFER_SIZE, n->name, 0);
	if (ioctl(fd, DM_DEV_REMOVE, io2)) {
	if (errno != ENXIO) {
	PLOG(WARNING) << "Failed to destroy dm device named " << n->name;
	}
	}
	} else {
	LOG(VERBOSE) << "Found unmanaged dm device named " << n->name;
	}
	nxt = n->next;
	} while (nxt);

	free(buffer);
	free(buffer2);
	close(fd);
	return 0;
	}

	void Devmapper::_align(void ptr, unsigned int a)
	{
	unsigned long agn = --a;

	return (void *) (((unsigned long) ptr + agn) & ~agn);
	}