From fb61ccb024bbcbfa01fab4799cb22f0d59b7d472 Mon Sep 17 00:00:00 2001 From: Mirko Banchi Date: Sun, 12 Sep 2010 14:27:31 +0200 Subject: [PATCH] Add BlockAckCache class --- src/devices/wifi/block-ack-cache.cc | 134 ++++++++++++++++++++++++++++ src/devices/wifi/block-ack-cache.h | 52 +++++++++++ src/devices/wifi/wscript | 2 + 3 files changed, 188 insertions(+) create mode 100644 src/devices/wifi/block-ack-cache.cc create mode 100644 src/devices/wifi/block-ack-cache.h diff --git a/src/devices/wifi/block-ack-cache.cc b/src/devices/wifi/block-ack-cache.cc new file mode 100644 index 000000000..c77e0a5c3 --- /dev/null +++ b/src/devices/wifi/block-ack-cache.cc @@ -0,0 +1,134 @@ +/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */ +/* + * Copyright (c) 2010 MIRKO BANCHI + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation; + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Mirko Banchi + */ +#include "block-ack-cache.h" +#include "ctrl-headers.h" +#include "wifi-mac-header.h" +#include "qos-utils.h" + +#define WINSIZE_ASSERT NS_ASSERT ((m_winEnd - m_winStart + 4096) % 4096 == m_winSize - 1) + +namespace ns3 { + +void +BlockAckCache::Init (uint16_t winStart, uint16_t winSize) +{ + m_winStart = winStart; + m_winSize = winSize <= 64 ? winSize : 64; + m_winEnd = ((m_winStart + m_winSize) % 4096) - 1; + memset (m_bitmap, 0, sizeof (m_bitmap)); +} + +void +BlockAckCache::UpdateWithMpdu (const WifiMacHeader *hdr) +{ + uint16_t seqNumber = hdr->GetSequenceNumber (); + if (!QosUtilsIsOldPacket (m_winStart, seqNumber)) + { + if (!IsInWindow (seqNumber)) + { + uint16_t delta = (seqNumber - m_winEnd + 4096) % 4096; + if (delta > 1) + { + ResetPortionOfBitmap ((m_winEnd + 1) % 4096, ((seqNumber - 1) + 4096) % 4096); + } + m_winStart = (m_winStart + delta) % 4096; + m_winEnd = seqNumber; + + WINSIZE_ASSERT; + } + m_bitmap[seqNumber] |= (0x0001<GetFragmentNumber ()); + } +} + +void +BlockAckCache::UpdateWithBlockAckReq (uint16_t startingSeq) +{ + if (!QosUtilsIsOldPacket (m_winStart, startingSeq)) + { + if (IsInWindow (startingSeq)) + { + if (startingSeq != m_winStart) + { + m_winStart = startingSeq; + uint16_t newWinEnd = ((m_winStart + m_winSize) % 4096) - 1; + ResetPortionOfBitmap ((m_winEnd + 1) % 4096, newWinEnd); + m_winEnd = newWinEnd; + + WINSIZE_ASSERT; + } + } + else + { + m_winStart = startingSeq; + m_winEnd = ((m_winStart + m_winSize) % 4096) - 1; + ResetPortionOfBitmap (m_winStart, m_winEnd); + + WINSIZE_ASSERT; + } + } +} + +void +BlockAckCache::ResetPortionOfBitmap (uint16_t start, uint16_t end) +{ + uint32_t i = start; + for (; i != end; i = (i + 1) % 4096) + { + m_bitmap[i] = 0; + } + m_bitmap[i] = 0; +} + +bool +BlockAckCache::IsInWindow (uint16_t seq) +{ + return ((seq - m_winStart + 4096) % 4096) < m_winSize; +} + +void +BlockAckCache::FillBlockAckBitmap (CtrlBAckResponseHeader *blockAckHeader) +{ + if (blockAckHeader->IsBasic ()) + { + NS_FATAL_ERROR ("Basic block ack is only partially implemented."); + } + else if (blockAckHeader->IsCompressed ()) + { + uint32_t i = blockAckHeader->GetStartingSequence (); + uint32_t end = ((i + m_winSize) % 4096) - 1; + for (; i != end; i = (i + 1) % 4096) + { + if (m_bitmap[i] == 1) + { + blockAckHeader->SetReceivedPacket (i); + } + } + if (m_bitmap[i] == 1) + { + blockAckHeader->SetReceivedPacket (i); + } + } + else if (blockAckHeader->IsMultiTid ()) + { + NS_FATAL_ERROR ("Multi-tid block ack is not supported."); + } +} + +} //namespace ns3 diff --git a/src/devices/wifi/block-ack-cache.h b/src/devices/wifi/block-ack-cache.h new file mode 100644 index 000000000..9cc2108f1 --- /dev/null +++ b/src/devices/wifi/block-ack-cache.h @@ -0,0 +1,52 @@ +/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */ +/* + * Copyright (c) 2010 MIRKO BANCHI + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation; + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Mirko Banchi + */ +#ifndef BLOCK_ACK_CACHE_H +#define BLOCK_ACK_CACHE_H + +#include + +namespace ns3 { + +class WifiMacHeader; +class CtrlBAckResponseHeader; + +class BlockAckCache +{ +public: + void Init (uint16_t winStart, uint16_t winSize); + + void UpdateWithMpdu (const WifiMacHeader *hdr); + void UpdateWithBlockAckReq (uint16_t startingSeq); + + void FillBlockAckBitmap (CtrlBAckResponseHeader *blockAckHeader); +private: + void ResetPortionOfBitmap (uint16_t start, uint16_t end); + bool IsInWindow (uint16_t seq); + + uint16_t m_winStart; + uint8_t m_winSize; + uint16_t m_winEnd; + + uint16_t m_bitmap[4096]; +}; + +} //namespace ns3 + +#endif /* BLOCK_ACK_CACHE_H */ diff --git a/src/devices/wifi/wscript b/src/devices/wifi/wscript index d34a48ac4..5b5b546ca 100644 --- a/src/devices/wifi/wscript +++ b/src/devices/wifi/wscript @@ -65,6 +65,7 @@ def build(bld): 'block-ack-agreement.cc', 'block-ack-manager.cc', 'block-ack-test-suite.cc', + 'block-ack-cache.cc' ] headers = bld.new_task_gen('ns3header') headers.module = 'wifi' @@ -123,6 +124,7 @@ def build(bld): 'ctrl-headers.h', 'block-ack-agreement.h', 'block-ack-manager.h', + 'block-ack-cache.h' ] if bld.env['ENABLE_GSL']: