ipv4_frag.h File Reference

IPv4 fragmentation and reassembly. More...

#include "core/net.h"
#include "ipv4/ipv4.h"

Go to the source code of this file.

Data Structures

struct  Ipv4ReassemblyBuffer
 Reassembly buffer. More...
struct  Ipv4FragDesc
 Fragmented packet descriptor. More...


#define IPV4_FRAG_TICK_INTERVAL   1000
#define IPV4_FRAG_TIME_TO_LIVE   15000
#define IPV4_INFINITY   0xFFFF


struct {
   char_t   type
   uint32_t   dataStart
   uint32_t   dataLength
   uint8_t   nameLength
   char_t   name []
   uint8_t   tokenLen: 4
   uint8_t   type: 2
   uint8_t   version: 2
   uint8_t   code
   uint16_t   mid
   uint8_t   token []
   union {
      uint8_t   b [6]
      uint16_t   w [3]
   uint16_t   srcPort
   uint16_t   destPort
   uint32_t   seqNum
   uint32_t   ackNum
   uint8_t   reserved1: 4
   uint8_t   dataOffset: 4
   uint8_t   flags: 6
   uint8_t   reserved2: 2
   uint16_t   window
   uint16_t   checksum
   uint16_t   urgentPointer
   uint8_t   options []
   uint16_t   length
   uint8_t   data []
   uint8_t   op
   uint8_t   htype
   uint8_t   hlen
   uint8_t   hops
   uint32_t   xid
   uint16_t   secs
   uint16_t   flags
   Ipv4Addr   ciaddr
   Ipv4Addr   yiaddr
   Ipv4Addr   siaddr
   Ipv4Addr   giaddr
   MacAddr   chaddr
   uint8_t   unused [10]
   uint8_t   sname [64]
   uint8_t   file [128]
   uint32_t   magicCookie
   uint16_t   type
   uint16_t   hardwareType
   uint32_t   time
   MacAddr   linkLayerAddr
   uint16_t   id
   uint8_t   rd: 1
   uint8_t   tc: 1
   uint8_t   aa: 1
   uint8_t   opcode: 4
   uint8_t   qr: 1
   uint8_t   rcode: 4
   uint8_t   z: 3
   uint8_t   ra: 1
   uint16_t   qdcount
   uint16_t   ancount
   uint16_t   nscount
   uint16_t   arcount
   uint8_t   questions []
   uint16_t   controlWord
   uint16_t   byteCount
   uint8_t   bLength
   uint8_t   bDescriptorType
   uint16_t   bcdUsb
   uint8_t   bDeviceClass
   uint8_t   bDeviceSubClass
   uint8_t   bDeviceProtocol
   uint8_t   bMaxPacketSize0
   uint16_t   idVendor
   uint16_t   idProduct
   uint16_t   bcdDevice
   uint8_t   iManufacturer
   uint8_t   iProduct
   uint8_t   iSerialNumber
   uint8_t   bNumConfigurations
   uint16_t   hrd
   uint16_t   pro
   uint8_t   hln
   uint8_t   pln
   uint16_t   op
   MacAddr   sha
   Ipv4Addr   spa
   MacAddr   tha
   Ipv4Addr   tpa
   uint8_t   maxRespTime
   Ipv4Addr   groupAddr
   uint8_t   length
   uint8_t   value []
   uint16_t   first
   uint16_t   last
   uint16_t   next
   union {
      uint8_t   b [16]
      uint16_t   w [8]
      uint32_t   dw [4]
   uint16_t   maxRespDelay
   uint16_t   reserved
   Ipv6Addr   multicastAddr
   uint32_t   reserved
   uint8_t   t: 1
   uint8_t   c: 1
   union {
      int32_t   integer
      uint8_t   octetString [1]
      uint8_t   oid [1]
      uint8_t   ipAddr [4]
      uint32_t   counter32
      uint32_t   gauge32
      uint32_t   unsigned32
      uint32_t   timeTicks
      uint64_t   counter64
   uint16_t   transactionId
   uint16_t   protocolId
   uint8_t   unitId
   uint8_t   pdu []
   uint8_t   retain: 1
   uint8_t   qos: 2
   uint8_t   dup: 1
   union {
      uint8_t   all
      struct {
         uint8_t   topicIdType: 2
         uint8_t   cleanSession: 1
         uint8_t   will: 1
         uint8_t   retain: 1
         uint8_t   qos: 2
         uint8_t   dup: 1
   uint8_t   b: 1
   uint8_t   identifier
   uint8_t   valueSize
   Ipv4Addr   srcIpAddr
   Ipv4Addr   destIpAddr
   Eui64   interfaceId
   uint16_t   mru
   uint8_t   peerIdLength
   uint8_t   peerId []
   uint32_t   seconds
   uint32_t   fraction
   uint16_t   opcode
   char_t   filename []
   uint8_t   reserved: 3
   uint8_t   fin: 1
   uint8_t   payloadLen: 7
   uint8_t   mask: 1
   uint8_t   extPayloadLen []
   uint32_t   length
   uint8_t   payload []
   uint32_t   packetLen
   uint8_t   paddingLen
   uint8_t   protocolVersionId
   uint8_t   bpduType
   StpBridgeId   rootId
   uint32_t   rootPathCost
   StpBridgeId   bridgeId
   uint16_t   portId
   uint16_t   messageAge
   uint16_t   maxAge
   uint16_t   helloTime
   uint16_t   forwardDelay
   uint8_t   version1Length
   uint16_t   priority
   MacAddr   addr
 Hole descriptor. More...


error_t ipv4FragmentDatagram (NetInterface *interface, Ipv4PseudoHeader *pseudoHeader, uint16_t id, const NetBuffer *payload, size_t payloadOffset, NetTxAncillary *ancillary)
 Fragment an IPv4 datagram into smaller packets. More...
void ipv4ReassembleDatagram (NetInterface *interface, const Ipv4Header *packet, size_t length, NetRxAncillary *ancillary)
 IPv4 datagram reassembly algorithm. More...
void ipv4FragTick (NetInterface *interface)
 Fragment reassembly timeout handler. More...
Ipv4FragDescipv4SearchFragQueue (NetInterface *interface, const Ipv4Header *packet)
 Search for a matching datagram in the reassembly queue. More...
void ipv4FlushFragQueue (NetInterface *interface)
 Flush IPv4 reassembly queue. More...
Ipv4HoleDescipv4FindHole (Ipv4FragDesc *frag, uint16_t offset)
 Retrieve hole descriptor. More...
void ipv4DumpHoleList (Ipv4FragDesc *frag)
 Dump hole descriptor list. More...


systime_t ipv4FragTickCounter

Detailed Description

IPv4 fragmentation and reassembly.


SPDX-License-Identifier: GPL-2.0-or-later

Copyright (C) 2010-2021 Oryx Embedded SARL. All rights reserved.

This file is part of CycloneTCP Open.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 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 General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

Oryx Embedded SARL (www.oryx-embedded.com)

Definition in file ipv4_frag.h.

Macro Definition Documentation



Definition at line 40 of file ipv4_frag.h.


#define IPV4_FRAG_TICK_INTERVAL   1000

Definition at line 47 of file ipv4_frag.h.


#define IPV4_FRAG_TIME_TO_LIVE   15000

Definition at line 69 of file ipv4_frag.h.


#define IPV4_INFINITY   0xFFFF

Definition at line 75 of file ipv4_frag.h.



Definition at line 62 of file ipv4_frag.h.



Definition at line 55 of file ipv4_frag.h.

Typedef Documentation

◆ Ipv4HoleDesc

typedef { ... } Ipv4HoleDesc

Hole descriptor.

Function Documentation

◆ ipv4DumpHoleList()

void ipv4DumpHoleList ( Ipv4FragDesc frag)

Dump hole descriptor list.

[in]fragIPv4 fragment descriptor

Definition at line 660 of file ipv4_frag.c.

◆ ipv4FindHole()

Ipv4HoleDesc* ipv4FindHole ( Ipv4FragDesc frag,
uint16_t  offset 

Retrieve hole descriptor.

[in]fragIPv4 fragment descriptor
[in]offsetOffset of the hole
A pointer to the hole descriptor is returned if the specified offset is valid. Otherwise NULL is returned

Definition at line 648 of file ipv4_frag.c.

◆ ipv4FlushFragQueue()

void ipv4FlushFragQueue ( NetInterface interface)

Flush IPv4 reassembly queue.

[in]interfaceUnderlying network interface

Definition at line 627 of file ipv4_frag.c.

◆ ipv4FragmentDatagram()

error_t ipv4FragmentDatagram ( NetInterface interface,
Ipv4PseudoHeader pseudoHeader,
uint16_t  id,
const NetBuffer payload,
size_t  payloadOffset,
NetTxAncillary ancillary 

Fragment an IPv4 datagram into smaller packets.

[in]interfaceUnderlying network interface
[in]pseudoHeaderIPv4 pseudo header
[in]idFragment identification
[in]payloadMulti-part buffer containing the payload
[in]payloadOffsetOffset to the first payload byte
[in]ancillaryAdditional options passed to the stack along with the packet
Error code

Definition at line 72 of file ipv4_frag.c.

◆ ipv4FragTick()

void ipv4FragTick ( NetInterface interface)

Fragment reassembly timeout handler.

This routine must be periodically called by the TCP/IP stack to handle IPv4 fragment reassembly timeout

[in]interfaceUnderlying network interface

Definition at line 456 of file ipv4_frag.c.

◆ ipv4ReassembleDatagram()

void ipv4ReassembleDatagram ( NetInterface interface,
const Ipv4Header packet,
size_t  length,
NetRxAncillary ancillary 

IPv4 datagram reassembly algorithm.

[in]interfaceUnderlying network interface
[in]packetPointer to the IPv4 fragmented packet
[in]lengthPacket length including header and payload
[in]ancillaryAdditional options passed to the stack along with the packet

Definition at line 184 of file ipv4_frag.c.

◆ ipv4SearchFragQueue()

Ipv4FragDesc* ipv4SearchFragQueue ( NetInterface interface,
const Ipv4Header packet 

Search for a matching datagram in the reassembly queue.

[in]interfaceUnderlying network interface
[in]packetIncoming IPv4 packet
Matching fragment descriptor

Definition at line 524 of file ipv4_frag.c.

Variable Documentation

◆ first

uint16_t first

Definition at line 95 of file ipv4_frag.h.

◆ ipv4FragTickCounter

systime_t ipv4FragTickCounter

Definition at line 57 of file ipv4_frag.c.

◆ last

uint16_t last

Definition at line 96 of file ipv4_frag.h.

◆ next

uint16_t next

Definition at line 97 of file ipv4_frag.h.