zeek/src/file_analysis/analyzer/extract/Extract.h
2020-08-20 16:11:46 -07:00

86 lines
2.5 KiB
C++

// See the file "COPYING" in the main distribution directory for copyright.
#pragma once
#include <string>
#include "Val.h"
#include "File.h"
#include "Analyzer.h"
#include "analyzer/extract/events.bif.h"
namespace zeek::file_analysis::detail {
/**
* An analyzer to extract content of files to local disk.
*/
class Extract : public zeek::file_analysis::Analyzer {
public:
/**
* Destructor. Will close the file that was used for data extraction.
*/
~Extract() override;
/**
* Write a chunk of file data to the local extraction file.
* @param data pointer to a chunk of file data.
* @param len number of bytes in the data chunk.
* @return false if there was no extraction file open and the data couldn't
* be written, else true.
*/
bool DeliverStream(const u_char* data, uint64_t len) override;
/**
* Report undelivered bytes.
* @param offset distance into the file where the gap occurred.
* @param len number of bytes undelivered.
* @return true
*/
bool Undelivered(uint64_t offset, uint64_t len) override;
/**
* Create a new instance of an Extract analyzer.
* @param args the \c AnalyzerArgs value which represents the analyzer.
* @param file the file to which the analyzer will be attached.
* @return the new Extract analyzer instance or a null pointer if the
* the "extraction_file" field of \a args wasn't set.
*/
static zeek::file_analysis::Analyzer* Instantiate(zeek::RecordValPtr args,
zeek::file_analysis::File* file);
/**
* Sets the maximum allowed extracted file size. A value of zero means
* "no limit".
* @param bytes number of bytes allowed to be extracted
*/
void SetLimit(uint64_t bytes) { limit = bytes; }
protected:
/**
* Constructor.
* @param args the \c AnalyzerArgs value which represents the analyzer.
* @param file the file to which the analyzer will be attached.
* @param arg_filename a file system path which specifies the local file
* to which the contents of the file will be extracted/written.
* @param arg_limit the maximum allowed file size.
*/
Extract(zeek::RecordValPtr args, zeek::file_analysis::File* file,
const std::string& arg_filename, uint64_t arg_limit);
private:
std::string filename;
int fd;
uint64_t limit;
uint64_t depth;
};
} // namespace zeek::file_analysis::detail
namespace file_analysis {
using Extract [[deprecated("Remove in v4.1. Use zeek::file_analysis::detail::Extract.")]] = zeek::file_analysis::detail::Extract;
} // namespace file_analysis