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#include "integrity.h"
#include "locks.h"
#include "image.h"
#include "globals.h"
#include "../shared/log.h"
#include "helper.h"
#include <pthread.h>
#include <stdlib.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <string.h>
#include <assert.h>
#include <sys/resource.h>
#define CHECK_QUEUE_SIZE 100
typedef struct
{
dnbd3_image_t *image;
int block;
} queue_entry;
static pthread_t thread;
static queue_entry checkQueue[CHECK_QUEUE_SIZE];
static pthread_mutex_t integrityQueueLock;
static pthread_cond_t queueSignal;
static int queueLen = -1;
static volatile bool bRunning = false;
static void* integrity_main(void *data);
/**
* Initialize the integrity check thread
*/
void integrity_init()
{
assert( queueLen == -1 );
pthread_mutex_init( &integrityQueueLock, NULL );
pthread_cond_init( &queueSignal, NULL );
pthread_mutex_lock( &integrityQueueLock );
queueLen = 0;
pthread_mutex_unlock( &integrityQueueLock );
bRunning = true;
if ( 0 != thread_create( &thread, NULL, &integrity_main, (void *)NULL ) ) {
bRunning = false;
logadd( LOG_WARNING, "Could not start integrity check thread. Corrupted images will not be detected." );
return;
}
}
void integrity_shutdown()
{
assert( queueLen != -1 );
logadd( LOG_DEBUG1, "Shutting down integrity checker...\n" );
pthread_mutex_lock( &integrityQueueLock );
pthread_cond_signal( &queueSignal );
pthread_mutex_unlock( &integrityQueueLock );
thread_join( thread, NULL );
while ( bRunning )
usleep( 10000 );
pthread_mutex_destroy( &integrityQueueLock );
pthread_cond_destroy( &queueSignal );
logadd( LOG_DEBUG1, "Integrity checker exited normally.\n" );
}
/**
* Schedule an integrity check on the given image for the given hash block.
* It is not checked whether the block is completely cached locally, so
* make sure it is before calling, otherwise it will result in falsely
* detected corruption.
*/
void integrity_check(dnbd3_image_t *image, int block)
{
int i, freeSlot = -1;
pthread_mutex_lock( &integrityQueueLock );
for (i = 0; i < queueLen; ++i) {
if ( freeSlot == -1 && checkQueue[i].image == NULL ) {
freeSlot = i;
} else if ( checkQueue[i].image == image && checkQueue[i].block == block ) {
pthread_mutex_unlock( &integrityQueueLock );
return;
}
}
if ( freeSlot == -1 ) {
if ( queueLen >= CHECK_QUEUE_SIZE ) {
pthread_mutex_unlock( &integrityQueueLock );
logadd( LOG_DEBUG1, "Check queue full, discarding check request...\n" );
return;
}
freeSlot = queueLen++;
}
checkQueue[freeSlot].image = image;
checkQueue[freeSlot].block = block;
pthread_cond_signal( &queueSignal );
pthread_mutex_unlock( &integrityQueueLock );
}
static void* integrity_main(void * data UNUSED)
{
int i;
uint8_t *buffer = NULL;
size_t bufferSize = 0;
setThreadName( "image-check" );
blockNoncriticalSignals();
#if defined(linux) || defined(__linux)
// Setting nice of this thread - this is not POSIX conforming, so check if other platforms support this.
// POSIX says that setpriority() should set the nice value of all threads belonging to the current process,
// but on linux you can do this per thread.
pid_t tid = syscall( SYS_gettid );
setpriority( PRIO_PROCESS, tid, 10 );
#endif
pthread_mutex_lock( &integrityQueueLock );
while ( !_shutdown ) {
if ( queueLen == 0 ) {
pthread_cond_wait( &queueSignal, &integrityQueueLock );
}
for (i = queueLen - 1; i >= 0; --i) {
if ( _shutdown ) break;
dnbd3_image_t * const image = image_lock( checkQueue[i].image );
checkQueue[i].image = NULL;
if ( i + 1 == queueLen ) queueLen--;
if ( image == NULL ) continue;
// We have the image. Call image_release() some time
spin_lock( &image->lock );
if ( image->crc32 != NULL && image->realFilesize != 0 ) {
int const blocks[2] = { checkQueue[i].block, -1 };
pthread_mutex_unlock( &integrityQueueLock );
const uint64_t fileSize = image->realFilesize;
const size_t required = IMGSIZE_TO_HASHBLOCKS(fileSize) * sizeof(uint32_t);
if ( required > bufferSize ) {
bufferSize = required;
if ( buffer != NULL ) free( buffer );
buffer = malloc( bufferSize );
}
memcpy( buffer, image->crc32, required );
spin_unlock( &image->lock );
if ( !image_checkBlocksCrc32( image->readFd, (uint32_t*)buffer, blocks, fileSize ) ) {
logadd( LOG_WARNING, "Hash check for block %d of %s failed!", blocks[0], image->name );
image_updateCachemap( image, blocks[0] * HASH_BLOCK_SIZE, (blocks[0] + 1) * HASH_BLOCK_SIZE, false );
}
pthread_mutex_lock( &integrityQueueLock );
} else {
spin_unlock( &image->lock );
}
// Release :-)
image_release( image );
}
}
pthread_mutex_unlock( &integrityQueueLock );
if ( buffer != NULL ) free( buffer );
bRunning = false;
return NULL ;
}
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