urbackup_backend/urbackupserver/server_prepare_hash.cpp
2017-05-16 22:34:09 +02:00

513 lines
13 KiB
C++

/*************************************************************************
* UrBackup - Client/Server backup system
* Copyright (C) 2011-2016 Martin Raiber
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
**************************************************************************/
#ifndef CLIENT_ONLY
#include "server_prepare_hash.h"
#include "server_hash.h"
#include "../common/data.h"
#include "../Interface/Server.h"
#include "../stringtools.h"
#include "server_log.h"
#include "../urbackupcommon/os_functions.h"
#include "../fileservplugin/chunk_settings.h"
#include "../md5.h"
#include <memory.h>
#include "../common/adler32.h"
#include "../urbackupcommon/file_metadata.h"
namespace
{
bool buf_is_zero(const char* buf, size_t bsize)
{
for (size_t i = 0; i < bsize; ++i)
{
if (buf[i] != 0)
{
return false;
}
}
return true;
}
const size_t hash_bsize = 512*1024;
}
BackupServerPrepareHash::BackupServerPrepareHash(IPipe *pPipe, IPipe *pOutput, int pClientid,
logid_t logid, bool ignore_hash_mismatch)
: logid(logid), ignore_hash_mismatch(ignore_hash_mismatch)
{
pipe=pPipe;
output=pOutput;
clientid=pClientid;
working=false;
chunk_patcher.setCallback(this);
chunk_patcher.setWithSparse(true);
has_error=false;
}
BackupServerPrepareHash::~BackupServerPrepareHash(void)
{
Server->destroy(pipe);
}
void BackupServerPrepareHash::operator()(void)
{
while(true)
{
working=false;
std::string data;
size_t rc=pipe->Read(&data);
if(data=="exit")
{
output->Write("exit");
Server->Log("server_prepare_hash Thread finished (exit)");
delete this;
return;
}
else if(data=="flush")
{
continue;
}
if(rc>0)
{
working=true;
CRData rd(&data);
int64 fileid;
rd.getVarInt(&fileid);
std::string temp_fn;
rd.getStr(&temp_fn);
int backupid;
rd.getInt(&backupid);
int incremental;
rd.getInt(&incremental);
char with_hashes;
rd.getChar(&with_hashes);
std::string tfn;
rd.getStr(&tfn);
std::string hashpath;
rd.getStr(&hashpath);
std::string hashoutput_fn;
rd.getStr(&hashoutput_fn);
bool diff_file=!hashoutput_fn.empty();
std::string old_file_fn;
rd.getStr(&old_file_fn);
int64 t_filesize;
rd.getInt64(&t_filesize);
std::string client_sha_dig;
rd.getStr(&client_sha_dig);
std::string sparse_extents_fn;
rd.getStr(&sparse_extents_fn);
char c_hash_func;
rd.getChar(&c_hash_func);
char c_has_snapshot;
rd.getChar(&c_has_snapshot);
bool has_snapshot = c_has_snapshot == 1;
FileMetadata metadata;
metadata.read(rd);
IFile *tf=Server->openFile(os_file_prefix((temp_fn)), MODE_READ);
IFile *old_file=NULL;
if(diff_file)
{
old_file=Server->openFile(os_file_prefix((old_file_fn)), MODE_READ);
if(old_file==NULL)
{
ServerLogger::Log(logid, "Error opening file \""+old_file_fn+"\" for reading. File: old_file. "+os_last_error_str()+" Target path: \""+tfn+"\"", LL_ERROR);
has_error=true;
if(tf!=NULL) Server->destroy(tf);
continue;
}
}
if(tf==NULL)
{
ServerLogger::Log(logid, "Error opening file \""+temp_fn+"\" for reading file. File: temp_fn. "+os_last_error_str()+" Target path: \""+tfn+"\"", LL_ERROR);
has_error=true;
if(old_file!=NULL)
{
Server->destroy(old_file);
}
}
else
{
std::auto_ptr<ExtentIterator> extent_iterator;
if (!sparse_extents_fn.empty())
{
IFile* sparse_extents_f = Server->openFile(sparse_extents_fn, MODE_READ);
if (sparse_extents_f != NULL)
{
extent_iterator.reset(new ExtentIterator(sparse_extents_f, true, hash_bsize));
}
}
ServerLogger::Log(logid, "PT: Hashing file \""+ExtractFileName(tfn)+"\"", LL_DEBUG);
std::string h;
if(!diff_file)
{
if (c_hash_func == HASH_FUNC_SHA512_NO_SPARSE
|| c_hash_func == HASH_FUNC_SHA512)
{
HashSha512 hashsha;
if (hash_sha(tf, extent_iterator.get(), c_hash_func != HASH_FUNC_SHA512_NO_SPARSE, hashsha))
{
h = hashsha.finalize();
}
}
else
{
TreeHash treehash(NULL);
if (hash_sha(tf, extent_iterator.get(), true, treehash))
{
h = treehash.finalize();
}
}
}
else
{
if (c_hash_func == HASH_FUNC_SHA512_NO_SPARSE
|| c_hash_func == HASH_FUNC_SHA512)
{
hashoutput_f = NULL;
HashSha512 hashsha;
hashf = &hashsha;
if (hash_with_patch(old_file, tf, extent_iterator.get(), c_hash_func != HASH_FUNC_SHA512_NO_SPARSE))
{
h = hashsha.finalize();
}
}
else
{
std::auto_ptr<IFile> l_hashoutput_f(Server->openFile(os_file_prefix(hashoutput_fn), MODE_READ));
hashoutput_f = l_hashoutput_f.get();
TreeHash treehash(NULL);
hashf = &treehash;
if (hash_with_patch(old_file, tf, extent_iterator.get(), true))
{
h = treehash.finalize();
}
hashoutput_f = NULL;
}
}
if (h.empty())
{
ServerLogger::Log(logid, "Error while hashing file \"" + tf->getFilename() + "\" (destination: \""+ tfn+"\"). Failing backup.", LL_ERROR);
has_error = true;
}
else if(!client_sha_dig.empty() && h!=client_sha_dig)
{
if (has_snapshot)
{
ServerLogger::Log(logid, "Client calculated hash of \"" + tfn + "\" differs from server calculated hash. "
"This may be caused by a bug or by random bit flips on the client or server hard disk. "
+(ignore_hash_mismatch?"":"Failing backup. ")+
"(Hash: "+ print_hash_func(c_hash_func)+
", client hash: "+base64_encode(reinterpret_cast<const unsigned char*>(client_sha_dig.data()), static_cast<unsigned int>(client_sha_dig.size()))+
", server hash: "+ base64_encode(reinterpret_cast<const unsigned char*>(h.data()), static_cast<unsigned int>(h.size()))+")", LL_ERROR);
if (!ignore_hash_mismatch)
{
has_error = true;
}
}
else
{
ServerLogger::Log(logid, "Client calculated hash of \"" + tfn + "\" differs from server calculated hash. "
"The file is being backed up without a snapshot so this is most likely caused by the file changing during the backup. "
"The backed up file may be corrupt and not a valid, consistent backup. "
"(Hash: "+print_hash_func(c_hash_func) + ")", LL_WARNING);
}
}
Server->destroy(tf);
if(old_file!=NULL)
{
Server->destroy(old_file);
}
CWData data;
data.addInt(BackupServerHash::EAction_LinkOrCopy);
data.addVarInt(fileid);
data.addString(temp_fn);
data.addInt(backupid);
data.addInt(incremental);
data.addChar(with_hashes);
data.addString(tfn);
data.addString(hashpath);
data.addString(h);
data.addString(hashoutput_fn);
data.addString(old_file_fn);
data.addInt64(t_filesize);
data.addString(sparse_extents_fn);
metadata.serialize(data);
output->Write(data.getDataPtr(), data.getDataSize() );
}
}
}
}
std::string BackupServerPrepareHash::calc_hash(IFsFile * f, std::string method)
{
FsExtentIterator extent_iterator(f, hash_bsize);
if (method=="sha512-nosparse"
|| method=="sha512-sparse")
{
HashSha512 hashsha;
if (hash_sha(f, &extent_iterator, method == "sha512-sparse", hashsha))
{
return hashsha.finalize();
}
}
else
{
TreeHash treehash(NULL);
if (hash_sha(f, &extent_iterator, true, treehash))
{
return treehash.finalize();
}
}
return std::string();
}
bool BackupServerPrepareHash::hash_sha(IFile *f, IExtentIterator* extent_iterator, bool hash_with_sparse, IHashFunc& hashf, IHashProgressCallback* progress_callback)
{
f->Seek(0);
std::vector<char> buf;
buf.resize(hash_bsize);
_u32 rc;
int64 fpos = 0;
IFsFile::SSparseExtent curr_extent;
if (extent_iterator != NULL)
{
extent_iterator->reset();
curr_extent = extent_iterator->nextExtent();
}
int64 skip_start = -1;
int64 skip_count = 0;
do
{
while (curr_extent.offset != -1
&& curr_extent.offset + curr_extent.size<fpos)
{
curr_extent = extent_iterator->nextExtent();
}
if (curr_extent.offset != -1
&& curr_extent.offset <= fpos
&& curr_extent.offset + curr_extent.size>=fpos + static_cast<int64>(hash_bsize))
{
if (skip_start == -1)
{
skip_start = fpos;
}
fpos += hash_bsize;
rc = hash_bsize;
continue;
}
if (skip_start != -1)
{
f->Seek(fpos);
}
bool has_read_error = false;
rc=f->Read(buf.data(), hash_bsize, &has_read_error);
if (has_read_error)
{
Server->Log("Error reading from file \"" + f->getFilename() + "\" while hashing", LL_ERROR);
return false;
}
if (hash_with_sparse
&& rc == hash_bsize
&& buf_is_zero(buf.data(), hash_bsize))
{
if (skip_start == -1)
{
skip_start = fpos;
}
fpos += hash_bsize;
rc = hash_bsize;
if (progress_callback != NULL)
{
progress_callback->hash_progress(fpos);
}
continue;
}
if (skip_start != -1)
{
++skip_count;
int64 skip[2];
skip[0] = skip_start;
skip[1] = fpos - skip_start;
hashf.sparse_hash(reinterpret_cast<char*>(&skip), sizeof(int64) * 2);
skip_start = -1;
}
if (rc > 0)
{
hashf.hash(buf.data(), rc);
fpos += rc;
if (progress_callback != NULL)
{
progress_callback->hash_progress(fpos);
}
}
}
while(rc>0);
if (progress_callback != NULL)
{
progress_callback->hash_progress(fpos);
}
return true;
}
bool BackupServerPrepareHash::hash_with_patch(IFile *f, IFile *patch, ExtentIterator* extent_iterator, bool hash_with_sparse)
{
has_sparse_extents = false;
if (hashoutput_f == NULL)
{
chunk_patcher.setRequireUnchanged(true);
chunk_patcher.setUnchangedAlign(0);
}
else
{
chunk_patcher.setRequireUnchanged(false);
chunk_patcher.setUnchangedAlign(hash_bsize);
}
file_pos = 0;
chunk_patcher.setWithSparse(hash_with_sparse);
bool b = chunk_patcher.ApplyPatch(f, patch, extent_iterator);
return b;
}
void BackupServerPrepareHash::addUnchangedHashes(int64 start, size_t size, bool* is_sparse)
{
assert(start%hash_bsize == 0);
assert(size==hash_bsize || start+size==chunk_patcher.getFilesize());
if (!hashoutput_f->Seek(sizeof(_i64) + (start / hash_bsize)*chunkhash_single_size))
{
Server->Log("Error seeking in hashoutput file " + hashoutput_f->getFilename(), LL_ERROR);
has_error = true;
}
bool has_read_error = false;
char chunkhashes[chunkhash_single_size];
_u32 r = hashoutput_f->Read(chunkhashes, chunkhash_single_size, &has_read_error);
if (has_read_error)
{
Server->Log("Error reading from " + hashoutput_f->getFilename(), LL_ERROR);
has_error = true;
}
assert(r == chunkhash_single_size || start + size == chunk_patcher.getFilesize());
size_t chunkhash_size = big_hash_size + small_hash_size*(size / c_small_hash_dist + (size%c_small_hash_dist == 0 ? 0 : 1));
assert(chunkhash_size==chunkhash_single_size || start + size == chunk_patcher.getFilesize());
std::string sparse_hashes = get_sparse_extent_content();
if (is_sparse!=NULL && memcmp(sparse_hashes.data(), chunkhashes, (std::min)(chunkhash_size, static_cast<size_t>(r))) == 0)
{
*is_sparse = true;
return;
}
reinterpret_cast<TreeHash*>(hashf)->addHashAllAdler(chunkhashes, r, size);
}
void BackupServerPrepareHash::next_sparse_extent_bytes(const char * buf, size_t bsize)
{
hashf->sparse_hash(buf, (unsigned int)bsize);
}
int64 BackupServerPrepareHash::chunk_patcher_pos()
{
return file_pos;
}
void BackupServerPrepareHash::next_chunk_patcher_bytes(const char *buf, size_t bsize, bool changed, bool* is_sparse)
{
if (buf != NULL)
{
hashf->hash(buf, (unsigned int)bsize);
}
else if(hashoutput_f!=NULL
&& (is_sparse==NULL || *is_sparse==false) )
{
addUnchangedHashes(file_pos, bsize, is_sparse);
}
file_pos += bsize;
}
bool BackupServerPrepareHash::isWorking(void)
{
return working;
}
bool BackupServerPrepareHash::hasError(void)
{
return has_error;
}
#endif //CLIENT_ONLY