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


error_t ipv4FragmentDatagram (NetInterface *interface, const 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...


typedef __packed_struct
 Hole descriptor. More...
uint16_t last
uint16_t next
systime_t ipv4FragTickCounter

Detailed Description

IPv4 fragmentation and reassembly.


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

Copyright (C) 2010-2023 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 54 of file ipv4_frag.h.


#define IPV4_FRAG_TIME_TO_LIVE   15000

Definition at line 76 of file ipv4_frag.h.


#define IPV4_INFINITY   0xFFFF

Definition at line 82 of file ipv4_frag.h.



Definition at line 69 of file ipv4_frag.h.



Definition at line 62 of file ipv4_frag.h.



Definition at line 47 of file ipv4_frag.h.

Function Documentation

◆ ipv4DumpHoleList()

void ipv4DumpHoleList ( Ipv4FragDesc frag)

Dump hole descriptor list.

[in]fragIPv4 fragment descriptor

Definition at line 694 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 682 of file ipv4_frag.c.

◆ ipv4FlushFragQueue()

void ipv4FlushFragQueue ( NetInterface interface)

Flush IPv4 reassembly queue.

[in]interfaceUnderlying network interface

Definition at line 661 of file ipv4_frag.c.

◆ ipv4FragmentDatagram()

error_t ipv4FragmentDatagram ( NetInterface interface,
const 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 488 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 557 of file ipv4_frag.c.

Variable Documentation

◆ __packed_struct

typedef __packed_struct
Initial value:
uint16_t first

Hole descriptor.

Definition at line 100 of file ipv4_frag.h.

◆ ipv4FragTickCounter

systime_t ipv4FragTickCounter

Definition at line 57 of file ipv4_frag.c.

◆ Ipv4HoleDesc


Definition at line 105 of file ipv4_frag.h.

◆ last

uint16_t last

Definition at line 103 of file ipv4_frag.h.

◆ next

uint16_t next

Definition at line 104 of file ipv4_frag.h.