4 // Fraunhofer Institute for Open Communication Systems (FOKUS)
5 // Competence Center NETwork research (NET), St. Augustin, GERMANY
6 // Stefan Bund <g0dil@berlios.de>
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 2 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the
20 // Free Software Foundation, Inc.,
21 // 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24 \brief Packet public header */
30 #include <boost/operators.hpp>
31 #include <boost/utility.hpp>
32 #include <boost/type_traits/is_integral.hpp>
33 #include "../Utils/Exception.hh"
34 #include "../Utils/Tags.hh"
35 #include "../Utils/safe_bool.hh"
36 #include "PacketInterpreter.hh"
38 //#include "Packet.mpp"
39 ///////////////////////////////hh.p////////////////////////////////////////
43 /** \defgroup packet_module Packet Handling
45 The basic groundwork of the %Packet library is the packet handling:
47 \li The packet classes provide access to a chain of packet headers (more generically called
49 \li They automatically manage the required memory resources and the shared packet data.
51 \section packet_module_chain The Interpreter Chain
53 The central data structure for a packet is the interpreter chain
55 \image html structure.png The Interpreter Chain
57 This image depicts a packet with several headers. Each interpreter is responsible for a
58 specific sub-range of the complete packet. This range always \e includes the packets payload
59 (This is, why we call the data structure interpreter and not header: The interpreter is
60 responsible for interpreting a range of the packet according to a specific protocol), the
61 packet interpreters are nested inside each other.
63 For each interpreter, this structure automatically divides the packet into three areas (each
64 of which are optional): The header, the payload and the trailer. Every packet will have
65 either a header or a payload section while most don't have a trailer.
67 As user of the library you always interact with the chain through one (or more) of the
68 interpreters. The interpreter provides methods to traverse to the following or preceding
69 header (interpreter) and provides two levels of access to the packet data: Generic low-level
70 access in the form of an STL compatible sequence and access to the parsed fields which are
71 provided by the parser associated with the concrete packet type.
73 \section packet_module_management Resource Management
75 The interface to the packet library is provided using a handle class (\ref Packet for
76 generic, protocol agnostic access and \ref ConcretePacket derived from \ref Packet to access
77 a specific protocol). This handle automatically manages the resources associated with the
78 packet (the interpreter chain and the data storage holding the packet data). The resources
79 are automatically released when the last packet handle referencing a specific packet is
82 \implementation The packet chain is provided on two levels: The internal representation \ref
83 PacketInterpreterBase and \ref PacketInterpreter which are referenced by the Handle
84 classes \ref Packet and \ref ConcretePacket. \n
85 The internal representation classes are pertinent in the sense, that they exist
86 regardless of the existence of a handle referencing them (as long as the packet
87 exists). Still the interpreter chain is lazy and packet interpreters beside the first
88 are only created dynamically when accessed (this is implemented in the handle not in the
89 internal representation). \n
90 The packet interpreters make use of a pool allocator. This provides extremely efficient
91 creation and destruction of packet interpreter's and removes the dynamic memory
92 management overhead from the packet interpreter management. The packet implementation
93 class (\ref PacketImpl which holds the packet data itself) however is still dynamically
94 managed (however there is only a single instance for each packet).
97 template <class PackeType> class ConcretePacket;
99 ///\addtogroup packet_module
102 /** \brief Main %Packet class
104 %Packet is the main externally visible class of the packet library. %Packet is a handle into
105 the internal packet representation. From %Packet you may access the data of that specific
106 sub-packet/header/interpreter and navigate to the neighboring
107 sub-packets/headers/interpreters.
109 %Packet is protocol agnostic. This class only provides non-protocol dependent members. To
110 access the protocol specific features of a packet (like header fields) the ConcretePacket
111 class extending %Packet is provided.
113 \section packet_semantics Semantics
115 All operations accessing the data of \c this packet in some way will ignore any preceding
116 packets/headers/interpreters in the chain. It does not matter, whether a given packet is
117 taken from the middle or the beginning of the chain, all operations (except those explicitly
118 accessing the chain of course) should work the same.
120 This especially includes members like clone() or append(): clone() will clone \e only from
121 \c this packet until the end of the chain, append() will append the given packet \e ignoring
122 any possibly preceding packets/headers/interpreters.
124 In the same way, the data() member provides an STL-sequence compatible view of the packet
125 data. This only includes the data which is part of \c this packet including header, trailer
126 \e and payload but \e not the headers or trailers of packets \e before \c this packet in the
127 packet/header/interpreter chain (nonetheless, this data overlaps with the data of other
130 Several members are member templates taking an \a OtherPacket template parameter. This
131 parameter must be the ConcretePacket instantiation associated with some concrete packet type
132 (protocol). For each implemented protocol, typedefs should be provided for these
133 instantiations (Example: \ref EthernetPacket is a typedef for
134 \ref ConcretePacket < \ref EthernetPacketType >).
137 \ref ConcretePacket for the %type specific interface\n
138 \ref PacketData for the sequence interface\n
139 \ref packetparser for a specification of the parser interface
142 : public safe_bool<Packet>,
143 public boost::equality_comparable<Packet>
146 ///////////////////////////////////////////////////////////////////////////
149 typedef void type; ///< Type of the packet.
150 typedef senf::detail::packet::size_type size_type;
151 ///< Unsigned type to represent packet size
152 typedef PacketInterpreterBase::factory_t factory_t; ///< Packet factory type (see below)
154 ///////////////////////////////////////////////////////////////////////////
155 ///\name Structors and default members
158 // default copy constructor
159 // default copy assignment
160 // default destructor
162 Packet(); ///< Create uninitialized packet handle
163 /**< An uninitialized handle is in - valid(). It does not
164 allow any operation except assignment and checking for
166 Packet clone() const; ///< Create copy packet
167 /**< clone() will create a complete copy of \c this
168 packet. The returned packet will have the same data and
169 packet chain. It does however not share any data with
170 the original packet. */
172 // conversion constructors
174 template <class PacketType>
175 Packet(ConcretePacket<PacketType> packet); ///< Copy-construct Packet from ConcretePacket
176 /**< This constructor allows to convert an arbitrary
177 ConcretePacket into a general Packet, loosing the
178 protocol specific interface. */
181 ///////////////////////////////////////////////////////////////////////////
183 ///\name Interpreter chain access
187 ///< Get next packet in chain
188 /**< \throws InvalidPacketChainException if no next packet
190 Packet next(NoThrow_t) const;
191 ///< Get next packet in chain
192 /**< \returns in - valid() packet if no next packet
194 template <class OtherPacket> OtherPacket next() const;
195 ///< Get next packet in chain and cast to \a OtherPacket
196 /**< \throws std::bad_cast if the next() packet is not of
198 \throws InvalidPacketChainException if no next packet
200 template <class OtherPacket> OtherPacket next(NoThrow_t) const;
201 ///< Get next packet in chain and cast to \a OtherPacket
202 /**< \throws std::bad_cast if the next() packet is not of
204 \returns in - valid() packet if no next packet
206 template <class OtherPacket> OtherPacket find() const;
207 ///< Search chain forward for packet of type \a OtherPacket
208 /**< The search will start with the current packet.
209 \throws InvalidPacketChainException if no packet of
210 type \a OtherPacket can be found. */
211 template <class OtherPacket> OtherPacket find(NoThrow_t) const;
212 ///< Search chain forward for packet of type \a OtherPacket
213 /**< The search will start with the current packet.
214 \returns in - valid() packet if no packet of type \a
215 OtherPacket can be found. */
218 ///< Get previous packet in chain
219 /**< \throws InvalidPacketChainException if no previous
221 Packet prev(NoThrow_t) const;
222 ///< Get previous packet in chain
223 /**< \returns in - valid() packet if no previous packet
225 template <class OtherPacket> OtherPacket prev() const;
226 ///< Get previous packet in chain and cast to \a OtherPacket
227 /**< \throws std::bad_cast, if the previous packet is not of
229 \throws InvalidPacketChainException if no previous
231 template <class OtherPacket> OtherPacket prev(NoThrow_t) const;
232 ///< Get previous packet in chain and cast to \a OtherPacket
233 /**< \throws std::bad_cast, if the previous packet is not of
235 \returns in - valid() packet if no previous packet
237 template <class OtherPacket> OtherPacket rfind() const;
238 ///< Search chain backwards for packet of type \a OtherPacket
239 /**< The search will start with the current packet.
240 \throws InvalidPacketChainException if no packet of
241 type \a OtherPacket can be found. */
242 template <class OtherPacket> OtherPacket rfind(NoThrow_t) const;
243 ///< Search chain backwards for packet of type \a OtherPacket
244 /**< The search will start with the current packet.
245 \returns in - valid() packet if no packet of type \a
246 OtherPacket can be found. */
249 Packet first() const;
250 ///< Return first packet in chain
251 template <class OtherPacket> OtherPacket first() const;
252 ///< Return first packet in chain and cast
253 /**< \throws std::bad_cast if the first() packet is not of
254 type \a OtherPacket */
257 ///< Return last packet in chain
258 template <class OtherPacket> OtherPacket last() const;
259 ///< Return last packet in chain and cast
260 /**< \throws std::bad_cast if the last() packet is not of
261 type \a OtherPacket */
264 template <class OtherPacket> OtherPacket parseNextAs() const;
265 ///< Interpret payload of \c this as \a OtherPacket
266 /**< parseNextAs() will throw away the packet chain after
267 the current packet if necessary. It will then parse the
268 payload section of \c this packet as given by \a
269 OtherPacket. The new packet is added to the chain after
271 \returns new packet instance sharing the same data and
272 placed after \c this packet in the chain. */
273 Packet parseNextAs(factory_t factory) const;
274 ///< Interpret payload of \c this as \a factory type packet
275 /**< parseNextAs() will throw away the packet chain after
276 the current packet if necessary. It will then parse the
277 payload section of \c this packet as given by \a
278 factory. The new packet is added to the chain after
280 \returns new packet instance sharing the same data and
281 placed after \c this packet in the chain. */
283 template <class OtherPacket> bool is() const;
284 ///< Check, whether \c this packet is of the given type
285 template <class OtherPacket> OtherPacket as() const;
286 ///< Cast current packet to the given type
287 /**< This operations returns a handle to the same packet
288 header/interpreter however cast to the given
290 \throws std::bad_cast if the current packet is not of
291 type \a OtherPacket */
293 Packet append(Packet packet) const; ///< Append the given packet to \c this packet
294 /**< This operation will replace the payload section of \c
295 this packet with \a packet. This operation will replace
296 the packet chain after \c this packet with a clone of
297 \a packet and will replace the raw data of the payload
298 of \c this with the raw data of \a packet. \c this
299 packet will not share any date with \a packet.
300 \returns Packet handle to the cloned \a packet, placed
301 after \c this in the packet/header/interpreter
309 PacketData & data() const; ///< Access the packets raw data container
310 size_type size() const; ///< Return size of packet in bytes
311 /**< This size does \e not include the size of any preceding
312 headers/packets/interpreters. It does however include
313 \c this packets payload. */
320 template <class Annotation>
321 Annotation & annotation();
325 ///\name Other methods
328 bool operator==(Packet other) const; ///< Check for packet identity
329 /**< Two packet handles compare equal if they really are the
330 same packet header in the same packet chain. */
331 bool boolean_test() const; ///< Check, whether the packet is valid()
333 bool valid() const; ///< Check, whether the packet is valid()
334 /**< An in - valid() packet does not allow any operation
335 except checking for validity and assignment. in -
336 valid() packets serve the same role as 0-pointers.
338 This is an alias for boolean_test() which is called
339 when using a packet in a boolean context. */
341 void finalizeThis(); ///< Update calculated fields
342 /**< The finalize() fammily of members will update
343 calculated packet fields: checksums, size fields and so
344 on. This includes any field, which can be set from
345 other information in the packet. Each concrete packet
346 type should document, which fields are set by
349 finalizeThis() will \e only process the current
350 header. Even if only changing fields in this protocol,
351 depending on the protocol it may not be enough to
352 finalize this header only. See the packet type
355 template <class Other>
356 void finalizeTo(); ///< Update calculated fields
357 /**< The finalize() fammily of members will update
358 calculated packet fields: checksums, size fields and so
359 on. This includes any field, which can be set from
360 other information in the packet. Each concrete packet
361 type should document, which fields are set by
364 finalizeTo() will automatically process all
365 packets/headers/interpreters from the \e first
366 occurrence of packet type \a Other (beginning at \c
367 this packet searching forward towards deeper nested
368 packets) backwards up to \c this.
370 This call is equivalent to
372 p.finalizeTo(p.next<Other>())
375 void finalizeTo(Packet other); ///< Update calculated fields
376 /**< The finalize() fammily of members will update
377 calculated packet fields: checksums, size fields and so
378 on. This includes any field, which can be set from
379 other information in the packet. Each concrete packet
380 type should document, which fields are set by
383 finalizeTo(other) will automatically process all
384 packets/headers/interpreters beginning at \a other
385 backwards towards outer packets up to \c this. */
387 void finalizeAll(); ///< Update calculated fields
388 /**< The finalize() fammily of members will update
389 calculated packet fields: checksums, size fields and so
390 on. This includes any field, which can be set from
391 other information in the packet. Each concrete packet
392 type should document, which fields are set by
395 finalizeAll() will automatically process all
396 packets/headers/interpreters from the end of the chain
397 (the most inner packet) backwards up to \c this.
399 This call is equivalent to
401 p.finalizeTo(p.last())
404 Beware, that finalizeAll() will \e not finalize any
405 headers before \c this, it will \e only process inner
408 void dump(std::ostream & os) const; ///< Write out a printable packet representation
409 /**< This method is provided mostly to help debugging packet
410 problems. Each concrete packet should implement a dump
411 method writing out all fields of the packet in a
412 readable representation. dump() will call this member
413 for each packet/header/interpreter in the chain from \c
414 this packet up to the end of the chain. */
416 TypeIdValue typeId() const; ///< Get id of \c this packet
417 /**< This value is used e.g. in the packet registry to
418 associate packet types with other information.
419 \returns A type holding the same information as a
420 type_info object, albeit assignable */
421 factory_t factory() const; ///< Return factory instance of \c this packet
422 /**< The returned factory instance can be used to create new
423 packets of the given type without knowing the concrete
424 type of the packet. The value may be stored away for
425 later use if needed. */
430 explicit Packet(PacketInterpreterBase::ptr packet);
432 PacketInterpreterBase::ptr ptr() const;
435 Packet checkNext() const;
436 Packet checkLast() const;
438 PacketInterpreterBase::ptr packet_;
440 template <class PacketType>
441 friend class ConcretePacket;
442 friend class PacketParserBase;
445 /** \brief Protocol specific packet handle
447 The ConcretePacket template class extends Packet to provide protocol/packet type specific
448 aspects. These are packet constructors and access to the parsed packet fields.
450 The \c PacketType template argument to ConcretePacket is a protocol specific and internal
451 policy class which defines the protocol specific behavior. To access a specific type of
452 packet, the library provides corresponding typedefs of ConcretePacket < \a SomePacketType >
453 (e.g. \ref EthernetPacket as typedef for \ref ConcretePacket < \ref EthernetPacketType >).
455 The new members provided by ConcretePacket over packet are mostly comprised of the packet
456 constructors. These come in three major flavors:
458 \li The create() family of constructors will create completely new packets.
459 \li The createAfter() family of constructors will create new packets (with new data for the
460 packet) \e after a given existing packet.
461 \li The createBefore() family of constructors will create new packets (again with new data)
462 \e before a given existing packet.
464 Whereas create() will create a completely new packet with it's own chain and data storage,
465 createAfter() and createBefore() extend a packet with additional
466 headers/interpreters. createAfter() will set the payload of the given packet to the new
467 packet whereas createBefore() will create a new packet with the existing packet as it's
470 createAfter() differs from Packet::parseNextAs() in that the former creates a new packet \e
471 replacing any possibly existing data whereas the latter will interpret the already \e
472 existing data as given by the type argument.
474 \see \ref PacketTypeBase for a specification of the interface to be provided by the \a
475 PacketType policy class.
477 template <class PacketType>
482 ///////////////////////////////////////////////////////////////////////////
485 typedef PacketType type;
486 typedef typename PacketType::parser Parser;
488 ///////////////////////////////////////////////////////////////////////////
489 ///\name Structors and default members
492 // default copy constructor
493 // default copy assignment
494 // default destructor
495 // no conversion constructors
497 ConcretePacket(); ///< Create uninitialized packet handle
498 /**< An uninitialized handle is not valid(). It does not
499 allow any operation except assignment and checking for
502 static factory_t factory(); ///< Return factory for packets of specific type
503 /**< This \e static member is like Packet::factory() for a
504 specific packet of type \a PacketType */
506 // Create completely new packet
508 static ConcretePacket create(); ///< Create default initialized packet
509 /**< The packet will be initialized to it's default empty
511 static ConcretePacket create(senf::NoInit_t); ///< Create uninitialized empty packet
512 /**< This will create a completely empty and uninitialized
513 packet with <tt>size() == 0</tt>.
514 \param[in] senf::noinit This parameter must always have the
515 value \c senf::noinit. */
516 static ConcretePacket create(size_type size); ///< Create default initialized packet
517 /**< This member will create a default initialized packet
518 with the given size. If the size parameter is smaller
519 than the minimum allowed packet size an exception will
521 \param[in] size Size of the packet to create in bytes.
522 \throws TruncatedPacketException if \a size is smaller
523 than the smallest permissible size for this type of
525 static ConcretePacket create(size_type size, senf::NoInit_t);
526 ///< Create uninitialized packet
527 /**< Creates an uninitialized (all-zero) packet of the exact
529 \param[in] size Size of the packet to create in bytes
530 \param[in] senf::noinit This parameter must always have the
531 value \c senf::noinit. */
533 template <class ForwardReadableRange>
534 static ConcretePacket create(
535 ForwardReadableRange const & range,
536 typename boost::disable_if< boost::is_integral<ForwardReadableRange> >::type * = 0);
538 template <class ForwardReadableRange>
539 static ConcretePacket create(ForwardReadableRange const & range);
540 ///< Create packet from given data
541 /**< The packet will be created from a copy of the given
542 data. The data from the range will be copied directly
543 into the packet representation. The data will \e not be
544 validated in any way.
546 href="http://www.boost.org/libs/range/index.html">Boost.Range</a>
547 of data to construct packet from. */
550 // Create packet as new packet after a given packet
552 static ConcretePacket createAfter(Packet packet);
553 ///< Create default initialized packet after \a packet
554 /**< The packet will be initialized to it's default empty
555 state. It will be appended as next header/interpreter
556 after \a packet in that packets interpreter chain.
557 \param[in] packet Packet to append new packet to. */
558 static ConcretePacket createAfter(Packet packet, senf::NoInit_t);
559 ///< Create uninitialized empty packet after\a packet
560 /**< This will create a completely empty and uninitialized
561 packet with <tt>size() == 0</tt>. It will be appended
562 as next header/interpreter after \a packet in that
563 packets interpreter chain.
564 \param[in] packet Packet to append new packet to.
565 \param[in] senf::noinit This parameter must always have the
566 value \c senf::noinit. */
567 static ConcretePacket createAfter(Packet packet, size_type size);
568 ///< Create default initialized packet after \a packet
569 /**< This member will create a default initialized packet
570 with the given size. If the size parameter is smaller
571 than the minimum allowed packet size an exception will
572 be thrown. It will be appended as next
573 header/interpreter after \a packet in that packets
575 \param[in] packet Packet to append new packet to.
576 \param[in] size Size of the packet to create in bytes.
577 \throws TruncatedPacketException if \a size is smaller
578 than the smallest permissible size for this type of
580 static ConcretePacket createAfter(Packet packet, size_type size, senf::NoInit_t);
581 ///< Create uninitialized packet after \a packet
582 /**< Creates an uninitialized (all-zero) packet of the exact
583 given size. It will be appended as next
584 header/interpreter after \a packet in that packets
586 \param[in] packet Packet to append new packet to.
587 \param[in] size Size of the packet to create in bytes
588 \param[in] senf::noinit This parameter must always have the
589 value \c senf::noinit. */
591 template <class ForwardReadableRange>
592 static ConcretePacket createAfter(
594 ForwardReadableRange const & range,
595 typename boost::disable_if< boost::is_integral<ForwardReadableRange> >::type * = 0);
597 template <class ForwardReadableRange>
598 static ConcretePacket createAfter(Packet packet,
599 ForwardReadableRange const & range);
600 ///< Create packet from given data after \a packet
601 /**< The packet will be created from a copy of the given
602 data. The data from the range will be copied directly
603 into the packet representation. The data will \e not be
604 validated in any way. It will be appended as next
605 header/interpreter after \a packet in that packets
607 \param[in] packet Packet to append new packet to.
609 href="http://www.boost.org/libs/range/index.html">Boost.Range</a>
610 of data to construct packet from. */
613 // Create packet as new packet (header) before a given packet
615 static ConcretePacket createBefore(Packet packet);
616 ///< Create default initialized packet before \a packet
617 /**< The packet will be initialized to it's default empty
618 state. It will be prepended as previous
619 header/interpreter before \a packet in that packets
621 \param[in] packet Packet to prepend new packet to. */
622 static ConcretePacket createBefore(Packet packet, senf::NoInit_t);
623 ///< Create uninitialized empty packet before \a packet
624 /**< Creates a completely empty and uninitialized packet. It
625 will be prepended as previous header/interpreter before
626 \a packet in that packets interpreter chain.
627 \param[in] packet Packet to prepend new packet to. */
629 // Create a clone of the current packet
631 ConcretePacket clone() const;
634 ///////////////////////////////////////////////////////////////////////////
638 Parser * operator->() const; ///< Access packet fields
639 /**< This operator allows to access the parsed fields of the
640 packet using the notation <tt>packet->field()</tt>. The
641 fields of the packet are specified by the PacketType's
644 The members are not strictly restricted to simple field
645 access. The parser class may have any member which is
646 needed for full packet access (e.g. checksum validation
648 \see \ref packetparser for the parser interface. */
650 Parser parser() const; ///< Access packet field parser directly
651 /**< Access the parser of the packet. This is the same
652 object returned by the operator->() operator. The
653 operator however does not allow to access this object
654 itself, only it's members.
655 \see \ref packetparser for the parser interface */
660 typedef PacketInterpreter<PacketType> interpreter;
662 ConcretePacket(typename interpreter::ptr packet_);
664 typename interpreter::ptr ptr() const;
667 friend class PacketInterpreter<PacketType>;
674 ///////////////////////////////hh.e////////////////////////////////////////
676 #if !defined(HH_Packets__decls_) && !defined(HH_Packet_i_)
678 #include "Packet.cci"
680 #include "Packet.cti"
687 // c-file-style: "senf"
688 // indent-tabs-mode: nil
689 // ispell-local-dictionary: "american"
690 // compile-command: "scons -u test"
691 // comment-column: 40