[svn] commit: r1451 - in /trunk/src/lib/dns: message.cc message.h
BIND 10 source code commits
bind10-changes at lists.isc.org
Tue Mar 16 17:00:15 UTC 2010
Author: jinmei
Date: Tue Mar 16 17:00:15 2010
New Revision: 1451
Log:
- added minimum level documentation
- overall cleanup
Modified:
trunk/src/lib/dns/message.cc
trunk/src/lib/dns/message.h
Modified: trunk/src/lib/dns/message.cc
==============================================================================
--- trunk/src/lib/dns/message.cc (original)
+++ trunk/src/lib/dns/message.cc Tue Mar 16 17:00:15 2010
@@ -268,11 +268,19 @@
void
Message::setHeaderFlag(const MessageFlag& flag) {
+ if (impl_->mode_ != Message::RENDER) {
+ isc_throw(InvalidMessageOperation,
+ "setHeaderFlag performed in non-render mode");
+ }
impl_->flags_ |= flag.getBit();
}
void
Message::clearHeaderFlag(const MessageFlag& flag) {
+ if (impl_->mode_ != Message::RENDER) {
+ isc_throw(InvalidMessageOperation,
+ "clearHeaderFlag performed in non-render mode");
+ }
impl_->flags_ &= ~flag.getBit();
}
@@ -315,6 +323,10 @@
void
Message::setQid(qid_t qid) {
+ if (impl_->mode_ != Message::RENDER) {
+ isc_throw(InvalidMessageOperation,
+ "setQid performed in non-render mode");
+ }
impl_->qid_ = qid;
}
@@ -325,6 +337,10 @@
void
Message::setRcode(const Rcode& rcode) {
+ if (impl_->mode_ != Message::RENDER) {
+ isc_throw(InvalidMessageOperation,
+ "setRcode performed in non-render mode");
+ }
impl_->rcode_ = rcode;
}
@@ -335,6 +351,10 @@
void
Message::setOpcode(const Opcode& opcode) {
+ if (impl_->mode_ != Message::RENDER) {
+ isc_throw(InvalidMessageOperation,
+ "setOpcode performed in non-render mode");
+ }
impl_->opcode_ = &opcode;
}
@@ -345,6 +365,11 @@
void
Message::addRRset(const Section& section, RRsetPtr rrset, const bool sign) {
+ if (impl_->mode_ != Message::RENDER) {
+ isc_throw(InvalidMessageOperation,
+ "addRRset performed in non-render mode");
+ }
+
// Note: should check duplicate (TBD)
impl_->rrsets_[sectionCodeToId(section)].push_back(rrset);
impl_->counts_[section.getCode()] += rrset->getRdataCount();
@@ -358,6 +383,11 @@
void
Message::addQuestion(const QuestionPtr question) {
+ if (impl_->mode_ != Message::RENDER) {
+ isc_throw(InvalidMessageOperation,
+ "addQuestion performed in non-render mode");
+ }
+
impl_->questions_.push_back(question);
++impl_->counts_[Section::QUESTION().getCode()];
}
@@ -814,6 +844,8 @@
"makeResponse() is performed in non-parse mode");
}
+ impl_->mode_ = Message::RENDER;
+
impl_->dnssec_ok_ = false;
impl_->remote_udpsize_ = impl_->udpsize_;
impl_->local_edns_ = RRsetPtr();
@@ -821,8 +853,6 @@
impl_->flags_ &= MESSAGE_REPLYPRESERVE;
setHeaderFlag(MessageFlag::QR());
-
- impl_->mode_ = Message::RENDER;
impl_->rrsets_[sectionCodeToId(Section::ANSWER())].clear();
impl_->counts_[Section::ANSWER().getCode()] = 0;
Modified: trunk/src/lib/dns/message.h
==============================================================================
--- trunk/src/lib/dns/message.h (original)
+++ trunk/src/lib/dns/message.h Tue Mar 16 17:00:15 2010
@@ -32,7 +32,9 @@
namespace dns {
///
-/// \brief A standard DNS module exception ...[TBD]
+/// \brief A standard DNS module exception that is thrown if a wire format
+/// message parser encounters a short length of data that don't even contain
+/// the full header section.
///
class MessageTooShort : public Exception {
public:
@@ -40,26 +42,39 @@
isc::Exception(file, line, what) {}
};
+///
+/// \brief A standard DNS module exception that is thrown if a section iterator
+/// is being constructed for an incompatible section. Specifically, this
+/// happens RRset iterator is being constructed for a Question section.
+///
class InvalidMessageSection : public Exception {
public:
InvalidMessageSection(const char* file, size_t line, const char* what) :
isc::Exception(file, line, what) {}
};
+///
+/// \brief A standard DNS module exception that is thrown if a \c Message
+/// class method is called that is prohibited for the current mode of
+/// the message.
+///
class InvalidMessageOperation : public Exception {
public:
InvalidMessageOperation(const char* file, size_t line, const char* what) :
isc::Exception(file, line, what) {}
};
+///
+/// \brief A standard DNS module exception that is thrown if a UDP buffer size
+/// smaller than the standard default maximum (DEFAULT_MAX_UDPSIZE) is
+/// being specified for the message.
+///
class InvalidMessageUDPSize : public Exception {
public:
InvalidMessageUDPSize(const char* file, size_t line, const char* what) :
isc::Exception(file, line, what) {}
};
-typedef uint8_t rcode_t; // we actually only need 4 bits of it
-typedef uint8_t opcode_t; // we actually only need 4 bits of it
typedef uint16_t qid_t;
class InputBuffer;
@@ -70,6 +85,10 @@
template <typename T>
struct SectionIteratorImpl;
+/// \brief The \c MessageFlag class objects represent standard flag bits
+/// of the header section of DNS messages.
+///
+/// Constant objects are defined for standard flags.
class MessageFlag {
public:
uint16_t getBit() const { return (flagbit_); }
@@ -134,6 +153,13 @@
return (f);
}
+/// \brief The \c Opcode class objects represent standard OPCODEs
+/// of the header section of DNS messages.
+///
+/// Note: since there are only 15 possible values, it may make more sense to
+/// simply define an enum type to represent these values.
+///
+/// Constant objects are defined for standard flags.
class Opcode {
public:
uint16_t getCode() const { return (code_); }
@@ -275,6 +301,11 @@
return (c);
}
+/// \brief The \c Rcode class objects represent standard Response Codes
+/// (RCODEs) of the header section of DNS messages, and extended response
+/// codes as defined in the EDNS specification.
+///
+/// Constant objects are defined for standard flags.
class Rcode {
public:
Rcode(uint16_t code);
@@ -426,6 +457,17 @@
return (c);
}
+/// \brief The \c Section class objects represent DNS message sections such
+/// as the header, question, or answer.
+///
+/// Note: this class doesn't seem to be very useful. We should probably
+/// revisit this design.
+///
+/// Note: whether or not it's represented as a class, we'll need a way
+/// to represent more advanced sections such as those used in dynamic updates.
+/// This is a TODO item.
+///
+/// Constant objects are defined for standard flags.
class Section {
public:
/// \brief Returns the relative position of the \c Section in DNS messages.
@@ -479,6 +521,10 @@
return (s);
}
+/// \c SectionIterator is a templated class to provide standard-compatible
+/// iterators for Questions and RRsets for a given DNS message section.
+/// The template parameter is either \c QuestionPtr (for the question section)
+/// or \c RRsetPtr (for the answer, authority, or additional section).
template <typename T>
class SectionIterator : public std::iterator<std::input_iterator_tag, T> {
public:
@@ -500,67 +546,218 @@
typedef SectionIterator<QuestionPtr> QuestionIterator;
typedef SectionIterator<RRsetPtr> RRsetIterator;
+/// \brief The \c Message class encapsulates a standard DNS message.
+///
+/// Details of the design and interfaces of this class is still in flux.
+/// Here are some notes about the current design.
+///
+/// Since many realistic DNS applications deal with messages, message objects
+/// will be frequently used, and can be performance sensitive. To minimize
+/// the performance overhead of constructing and destructing the objects,
+/// this class is designed to be reusable. The \c clear() method is provided
+/// for this purpose.
+///
+/// A \c Message class object is in either the \c PARSE or the \c RENDER mode.
+/// A \c PARSE mode object is intended to be used to convert wire-format
+/// message data into a complete \c Message object.
+/// A \c RENDER mode object is intended to be used to convert a \c Message
+/// object into wire-format data.
+/// Some of the method functions of this class is limited to a specific mode.
+/// In general, "set" type operations are only allowed for \c RENDER mode
+/// objects.
+/// The initial mode must be specified on construction, and can be changed
+/// through some method functions.
+///
+/// This class uses the "pimpl" idiom, and hide detailed implementation
+/// through the \c impl_ pointer. Since a \c Message object is expected to
+/// be reused, the construction overhead of this approach should be acceptable.
+///
+/// Open issues (among other things):
+/// - We may want to provide an "iterator" for all RRsets/RRs for convenience.
+/// This will be for applications that do not care about performance much,
+/// so the implementation can only be moderately efficient.
+/// - may want to provide a "find" method for a specified type
+/// of RR in the message.
class Message {
public:
enum Mode {
PARSE = 0,
RENDER = 1
};
-public:
+
+ ///
+ /// \name Constructors and Destructor
+ ///
+ /// Note: The copy constructor and the assignment operator are intentionally
+ /// defined as private. The intended use case wouldn't require copies of
+ /// a \c Message object; once created, it would normally be expected to
+ /// be reused, changing the mode from \c PARSE to \c RENDER, and vice
+ /// versa.
+ //@{
+public:
+ /// \brief The constructor.
+ /// The mode of the message is specified by the \c mode parameter.
Message(Mode mode);
+ /// \brief The destructor.
~Message();
private:
Message(const Message& source);
Message& operator=(const Message& source);
-public:
+ //@}
+public:
+ /// \brief Return whether the specified header flag bit is set in the
+ /// header section.
bool getHeaderFlag(const MessageFlag& flag) const;
+
+ /// \brief Set the specified header flag bit is set in the header section.
+ ///
+ /// Only allowed in the \c RENDER mode.
void setHeaderFlag(const MessageFlag& flag);
+
+ /// \brief Clear the specified header flag bit is set in the header section.
+ ///
+ /// Only allowed in the \c RENDER mode.
+ /// Note: it may make more sense to integrate this method into \c
+ /// \c setHeaderFlag() with an additional argument.
void clearHeaderFlag(const MessageFlag& flag);
+
+ /// \brief Return whether the message sender indicates DNSSEC is supported.
+ /// If EDNS is included, this corresponds to the value of the DO bit.
+ /// Otherwise, DNSSEC is considered not supported.
bool isDNSSECSupported() const;
+
+ /// \brief Specify whether DNSSEC is supported in the message.
+ ///
+ /// Only allowed in the \c RENDER mode.
+ /// If EDNS is included in the message, the DO bit is set or cleared
+ /// according to the specified value of this method.
void setDNSSECSupported(bool on);
+
+ /// \brief Return the maximum buffer size of UDP messages for the sender
+ /// of the message.
+ ///
+ /// The semantics of this value is different based on the mode:
+ /// In the \c PARSE mode, it means the buffer size of the remote node;
+ /// in the \c RENDER mode, it means the buffer size of the local node.
+ ///
+ /// In either case, its value is the value of the UDP payload size field
+ /// of EDNS (when it's included) or \c DEFAULT_MAX_UDPSIZE.
+ ///
+ /// Note: this interface may be confusing and may have to be revisited.
uint16_t getUDPSize() const;
+
+ /// \brief Specify the maximum buffer size of UDP messages of the local
+ /// node.
+ ///
+ /// Only allowed in the \c RENDER mode.
+ /// If EDNS OPT RR is included in the message, its UDP payload size field
+ /// will be set to the specified value.
void setUDPSize(uint16_t size);
+
+ /// \brief Return the query ID given in the header section of the message.
qid_t getQid() const;
+
+ /// \brief Set the query ID of the header section of the message.
+ ///
+ /// Only allowed in the \c RENDER mode.
void setQid(qid_t qid);
+
+ /// \brief Return the Response Code of the message.
+ ///
+ /// This includes extended codes specified by an EDNS OPT RR (when
+ /// included). In the \c PARSE mode, if the received message contains
+ /// an EDNS OPT RR, the corresponding extended code is identified and
+ /// returned.
const Rcode& getRcode() const;
+
+ /// \brief Return the Response Code of the message.
+ ///
+ /// Only allowed in the \c RENDER mode.
+ /// If the specified code is an EDNS extended RCODE, an EDNS OPT RR will be
+ /// included in the message.
void setRcode(const Rcode& rcode);
+
+ /// \brief Return the OPCODE given in the header section of the message.
const Opcode& getOpcode() const;
+
+ /// \brief Set the OPCODE of the header section of the message.
+ ///
+ /// Only allowed in the \c RENDER mode.
void setOpcode(const Opcode& opcode);
- std::string toText() const;
+
/// \brief Returns the number of RRs contained in the given section.
unsigned int getRRCount(const Section& section) const;
- // Open issues:
- // - may want to provide an "iterator" for all RRsets/RRs
- // - may want to provide a "find" method for a specified type
- // of RR in the message
+ /// \brief Return an iterator corresponding to the beginning of the
+ /// Question section of the message.
const QuestionIterator beginQuestion() const;
+
+ /// \brief Return an iterator corresponding to the end of the
+ /// Question section of the message.
const QuestionIterator endQuestion() const;
+
+ /// \brief Return an iterator corresponding to the beginning of the
+ /// given section (other than Question) of the message.
const RRsetIterator beginSection(const Section& section) const;
+
+ /// \brief Return an iterator corresponding to the end of the
+ /// given section (other than Question) of the message.
const RRsetIterator endSection(const Section& section) const;
+ /// \brief Add a (pointer like object of) Question to the message.
+ ///
+ /// Only allowed in the \c RENDER mode.
void addQuestion(QuestionPtr question);
+
+ /// \brief Add a (pointer like object of) Question to the message.
+ ///
+ /// This version internally creates a \c QuestionPtr object from the
+ /// given \c question and calls the other version of this method.
+ /// So this is inherently less efficient, but is provided because this
+ /// form may be more intuitive and may make more sense for performance
+ /// insensitive applications.
+ ///
+ /// Only allowed in the \c RENDER mode.
void addQuestion(const Question& question);
- void removeQuestion(QuestionPtr question);
+
+ /// \brief Add a (pointer like object of) RRset to the given section
+ /// of the message.
+ ///
+ /// This interface takes into account the RRSIG possibly attached to
+ /// \c rrset. This interface design needs to be revisited later.
+ ///
+ /// Only allowed in the \c RENDER mode.
void addRRset(const Section& section, RRsetPtr rrset, bool sign = false);
- void removeRRset(const Section& section, RRsetPtr rrset);
+
+ // The following methods are not currently implemented.
+ //void removeQuestion(QuestionPtr question);
+ //void removeRRset(const Section& section, RRsetPtr rrset);
// notyet:
//void addRR(const Section& section, const RR& rr);
//void removeRR(const Section& section, const RR& rr);
+ /// \brief Clear the message content (if any) and reinitialize it in the
+ /// specified mode.
void clear(Mode mode);
- // prepare for making a response from a request. This will clear the
- // DNS header except those fields that should be kept for the response,
- // and clear answer and the following sections.
- // see also dns_message_reply() of BIND9.
+ /// \brief Prepare for making a response from a request.
+ ///
+ /// This will clear the DNS header except those fields that should be kept
+ /// for the response, and clear answer and the following sections.
+ /// See also dns_message_reply() of BIND9.
void makeResponse();
- /// \brief Render message.
+ /// \brief Convert the Message to a string.
+ std::string toText() const;
+
+ /// \brief Render the message in wire formant into a \c MessageRenderer
+ /// object.
void toWire(MessageRenderer& renderer);
- /// \brief Parse a DNS message.
+ /// \brief Parse the header section of the \c Message.
void parseHeader(InputBuffer& buffer);
+
+ /// \brief Parse the \c Message.
void fromWire(InputBuffer& buffer);
///
More information about the bind10-changes
mailing list