BinaryTokenizer.h

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/*
 * Copyright (C) 1996-2023 The Squid Software Foundation and contributors
 *
 * Squid software is distributed under GPLv2+ license and includes
 * contributions from numerous individuals and organizations.
 * Please see the COPYING and CONTRIBUTORS files for details.
 */
 
#ifndef SQUID_SRC_PARSER_BINARYTOKENIZER_H
#define SQUID_SRC_PARSER_BINARYTOKENIZER_H
 
#include "ip/forward.h"
#include "parser/forward.h"
#include "sbuf/SBuf.h"
 
namespace Parser
{
 
class BinaryTokenizer;
 
class BinaryTokenizerContext
{
public:
    explicit BinaryTokenizerContext(BinaryTokenizer &tk, const char *aName);
    ~BinaryTokenizerContext() { close(); }
 
    inline void close();
 
    inline void success();
 
    BinaryTokenizer &tokenizer; 
    const BinaryTokenizerContext * const parent; 
    const char *const name; 
    uint64_t start; 
};
 
class BinaryTokenizer
{
public:
    typedef ::Parser::InsufficientInput InsufficientInput;
    typedef uint64_t size_type; // enough for the largest supported offset
 
    BinaryTokenizer();
    explicit BinaryTokenizer(const SBuf &data, const bool expectMore = false);
 
    void reset(const SBuf &data, const bool expectMore);
 
    void reinput(const SBuf &data, const bool expectMore) { data_ = data; expectMore_ = expectMore; }
 
    void commit();
 
    void rollback();
 
    bool atEnd() const;
 
    uint8_t uint8(const char *description);
 
    uint16_t uint16(const char *description);
 
    uint32_t uint24(const char *description);
 
    uint32_t uint32(const char *description);
 
    SBuf area(uint64_t size, const char *description);
 
    Ip::Address inet4(const char *description);
 
    Ip::Address inet6(const char *description);
 
    /*
     * Variable-length arrays (a.k.a. Pascal or prefix strings).
     * pstringN() extracts and returns N-bit length followed by length bytes
     */
    SBuf pstring8(const char *description); 
    SBuf pstring16(const char *description); 
    SBuf pstring24(const char *description); 
 
    void skip(uint64_t size, const char *description);
 
    uint64_t parsed() const { return parsed_; }
 
    SBuf leftovers() const { return data_.substr(parsed_); }
 
    void got(uint64_t size, const char *description) const;
 
    const BinaryTokenizerContext *context; 
 
protected:
    uint32_t octet();
    void want(uint64_t size, const char *description) const;
    void got(uint32_t value, uint64_t size, const char *description) const;
    void got(const SBuf &value, uint64_t size, const char *description) const;
    void got(const Ip::Address &value, uint64_t size, const char *description) const;
    void skipped(uint64_t size, const char *description) const;
 
private:
    template <class InAddr>
    Ip::Address inetAny(const char *description);
 
    SBuf data_;
    uint64_t parsed_; 
    uint64_t syncPoint_; 
    bool expectMore_; 
};
 
/* BinaryTokenizerContext */
 
inline
BinaryTokenizerContext::BinaryTokenizerContext(BinaryTokenizer &tk, const char *aName):
    tokenizer(tk),
    parent(tk.context),
    name(aName),
    start(tk.parsed())
{
    tk.context = this;
}
 
inline
void
BinaryTokenizerContext::close() {
    tokenizer.context = parent;
}
 
inline
void
BinaryTokenizerContext::success() {
    tokenizer.got(tokenizer.parsed() - start, "");
    close();
}
 
} /* namespace Parser */
 
#endif // SQUID_SRC_PARSER_BINARYTOKENIZER_H