A Discrete-Event Network Simulator
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wifi-assoc-manager.cc
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1/*
2 * Copyright (c) 2022 Universita' degli Studi di Napoli Federico II
3
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation;
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Author: Stefano Avallone <stavallo@unina.it>
19 */
20
21#include "wifi-assoc-manager.h"
22
23#include "sta-wifi-mac.h"
24
25#include "ns3/log.h"
26
27#include <algorithm>
28
29namespace ns3
30{
31
32NS_LOG_COMPONENT_DEFINE("WifiAssocManager");
33
34NS_OBJECT_ENSURE_REGISTERED(WifiAssocManager);
35
37 : m_manager(manager)
38{
39}
40
41bool
43 const StaWifiMac::ApInfo& rhs) const
44{
45 NS_ASSERT_MSG(lhs.m_bssid != rhs.m_bssid,
46 "Comparing two ApInfo objects with the same BSSID: " << lhs.m_bssid);
47
48 bool lhsBefore = m_manager.Compare(lhs, rhs);
49 if (lhsBefore)
50 {
51 return true;
52 }
53
54 bool rhsBefore = m_manager.Compare(rhs, lhs);
55 if (rhsBefore)
56 {
57 return false;
58 }
59
60 // the Compare method implemented by subclass may be such that the two ApInfo objects
61 // compare equal; in such a case, use the BSSID as tie breaker
62 return lhs.m_bssid < rhs.m_bssid;
63}
64
67{
68 static TypeId tid = TypeId("ns3::WifiAssocManager").SetParent<Object>().SetGroupName("Wifi");
69 return tid;
70}
71
73 : m_scanParams(), // zero-initialization
75{
76}
77
79{
80 NS_LOG_FUNCTION(this);
81}
82
83void
85{
86 NS_LOG_FUNCTION(this);
87 m_mac = nullptr;
88}
89
90void
92{
93 NS_LOG_FUNCTION(this << mac);
94 m_mac = mac;
95}
96
99{
100 return m_apList;
101}
102
103const WifiScanParams&
105{
106 return m_scanParams;
107}
108
109bool
111{
112 NS_LOG_FUNCTION(this << apInfo);
113
115 {
116 // we need to check if AP's advertised SSID matches the requested SSID
117 Ssid apSsid;
118 if (auto beacon = std::get_if<MgtBeaconHeader>(&apInfo.m_frame); beacon)
119 {
120 apSsid = beacon->Get<Ssid>().value();
121 }
122 else
123 {
124 auto probeResp = std::get_if<MgtProbeResponseHeader>(&apInfo.m_frame);
125 NS_ASSERT(probeResp);
126 apSsid = probeResp->Get<Ssid>().value();
127 }
128 if (!apSsid.IsEqual(m_scanParams.ssid))
129 {
130 NS_LOG_DEBUG("AP " << apInfo.m_bssid << " does not advertise our SSID " << apSsid
131 << " " << m_scanParams.ssid);
132 return false;
133 }
134 }
135
136 // we need to check if the AP is operating on a requested channel
137 auto channelMatch = [&apInfo](auto&& channel) {
138 if (channel.number != 0 && channel.number != apInfo.m_channel.number)
139 {
140 return false;
141 }
142 if (channel.band != WIFI_PHY_BAND_UNSPECIFIED && channel.band != apInfo.m_channel.band)
143 {
144 return false;
145 }
146 return true;
147 };
148
150 if (std::find_if(m_scanParams.channelList[apInfo.m_linkId].cbegin(),
151 m_scanParams.channelList[apInfo.m_linkId].cend(),
152 channelMatch) == m_scanParams.channelList[apInfo.m_linkId].cend())
153 {
154 NS_LOG_DEBUG("AP " << apInfo.m_bssid << " is not operating on a requested channel");
155 return false;
156 }
157
158 return true;
159}
160
161void
163{
164 NS_LOG_FUNCTION(this);
165 m_scanParams = std::move(scanParams);
166
167 // remove stored AP information not matching the scanning parameters
168 for (auto ap = m_apList.begin(); ap != m_apList.end();)
169 {
170 if (!MatchScanParams(*ap))
171 {
172 // remove AP info from list
173 m_apListIt.erase(ap->m_bssid);
174 ap = m_apList.erase(ap);
175 }
176 else
177 {
178 ++ap;
179 }
180 }
181
183}
184
185void
187{
188 NS_LOG_FUNCTION(this << apInfo);
189
190 if (!CanBeInserted(apInfo) || !MatchScanParams(apInfo))
191 {
192 return;
193 }
194
195 // check if an ApInfo object with the same BSSID is already present in the
196 // sorted list of ApInfo objects. This is done by trying to insert the BSSID
197 // in the hash table (insertion fails if the BSSID is already present)
198 auto [hashIt, hashInserted] = m_apListIt.insert({apInfo.m_bssid, {}});
199 if (!hashInserted)
200 {
201 // an element with the searched BSSID is already present in the hash table.
202 // Remove the corresponding ApInfo object from the sorted list.
203 m_apList.erase(hashIt->second);
204 }
205 // insert the ApInfo object
206 auto [listIt, listInserted] = m_apList.insert(std::move(apInfo));
207 // update the hash table entry
208 NS_ASSERT_MSG(listInserted,
209 "An entry (" << listIt->m_apAddr << ", " << listIt->m_bssid << ", "
210 << +listIt->m_linkId
211 << ") prevented insertion of given ApInfo object");
212 hashIt->second = listIt;
213}
214
215void
217{
218 NS_LOG_FUNCTION(this);
219
220 StaWifiMac::ApInfo bestAp;
221
222 do
223 {
224 if (m_apList.empty())
225 {
226 m_mac->ScanningTimeout(std::nullopt);
227 return;
228 }
229
230 bestAp = std::move(m_apList.extract(m_apList.begin()).value());
231 m_apListIt.erase(bestAp.m_bssid);
232 } while (!CanBeReturned(bestAp));
233
234 m_mac->ScanningTimeout(std::move(bestAp));
235}
236
237std::list<std::pair<uint8_t, uint8_t>>&
239{
240 return const_cast<std::list<std::pair<uint8_t, uint8_t>>&>(apInfo.m_setupLinks);
241}
242
243bool
245{
246 NS_LOG_FUNCTION(this);
247
248 if (m_mac->GetNLinks() == 1 || GetSortedList().empty())
249 {
250 return false;
251 }
252
253 // Get the Multi-Link Element and the RNR element, if present,
254 // from Beacon or Probe Response
255 if (auto beacon = std::get_if<MgtBeaconHeader>(&m_apList.begin()->m_frame); beacon)
256 {
257 mle = beacon->Get<MultiLinkElement>();
258 rnr = beacon->Get<ReducedNeighborReport>();
259 }
260 else
261 {
262 auto probeResp = std::get_if<MgtProbeResponseHeader>(&m_apList.begin()->m_frame);
263 NS_ASSERT(probeResp);
264 mle = probeResp->Get<MultiLinkElement>();
265 rnr = probeResp->Get<ReducedNeighborReport>();
266 }
267
268 if (!mle.has_value())
269 {
270 NS_LOG_DEBUG("No Multi-Link Element in Beacon/Probe Response");
271 return false;
272 }
273
274 if (!rnr.has_value() || rnr->get().GetNNbrApInfoFields() == 0)
275 {
276 NS_LOG_DEBUG("No Reduced Neighbor Report Element in Beacon/Probe Response");
277 return false;
278 }
279
280 // The Multi-Link Element must contain the MLD MAC Address subfield and the
281 // Link ID Info subfield
282 if (!mle->get().HasLinkIdInfo())
283 {
284 NS_LOG_DEBUG("No Link ID Info subfield in the Multi-Link Element");
285 return false;
286 }
287
288 return true;
289}
290
291std::optional<WifiAssocManager::RnrLinkInfo>
293{
294 NS_LOG_FUNCTION(nbrApInfoId);
295
296 while (nbrApInfoId < rnr.GetNNbrApInfoFields())
297 {
298 if (!rnr.HasMldParameters(nbrApInfoId))
299 {
300 // this Neighbor AP Info field is not suitable to setup a link
301 nbrApInfoId++;
302 continue;
303 }
304
305 std::size_t tbttInfoFieldIndex = 0;
306 while (tbttInfoFieldIndex < rnr.GetNTbttInformationFields(nbrApInfoId) &&
307 rnr.GetMldId(nbrApInfoId, tbttInfoFieldIndex) != 0)
308 {
309 tbttInfoFieldIndex++;
310 }
311
312 if (tbttInfoFieldIndex < rnr.GetNTbttInformationFields(nbrApInfoId))
313 {
314 // this Neighbor AP Info field contains an AP affiliated to the
315 // same AP MLD as the reporting AP
316 return RnrLinkInfo{nbrApInfoId, tbttInfoFieldIndex};
317 }
318 nbrApInfoId++;
319 }
320
321 return std::nullopt;
322}
323
324std::list<WifiAssocManager::RnrLinkInfo>
326{
327 std::list<WifiAssocManager::RnrLinkInfo> apList;
328 std::size_t nbrApInfoId = 0;
329 std::optional<WifiAssocManager::RnrLinkInfo> next;
330
331 while ((next = GetNextAffiliatedAp(rnr, nbrApInfoId)).has_value())
332 {
333 apList.push_back({*next});
334 nbrApInfoId = next->m_nbrApInfoId + 1;
335 }
336
337 return apList;
338}
339
340} // namespace ns3
A base class which provides memory management and object aggregation.
Definition: object.h:89
Smart pointer class similar to boost::intrusive_ptr.
Definition: ptr.h:78
The Reduced Neighbor Report element.
std::size_t GetNNbrApInfoFields() const
Get the number of Neighbor AP Information fields.
std::size_t GetNTbttInformationFields(std::size_t nbrApInfoId) const
Get the number of TBTT Information fields included in the TBTT Information Set field of the given Nei...
uint8_t GetMldId(std::size_t nbrApInfoId, std::size_t index) const
Get the MLD ID value in the MLD Parameters subfield (must be present) in the i-th TBTT Information fi...
bool HasMldParameters(std::size_t nbrApInfoId) const
Return true if the MLD Parameters subfield is present in all the TBTT Information fields of the given...
The IEEE 802.11 SSID Information Element.
Definition: ssid.h:36
bool IsEqual(const Ssid &o) const
Check if the two SSIDs are equal.
Definition: ssid.cc:61
bool IsBroadcast() const
Check if the SSID is broadcast.
Definition: ssid.cc:72
void ScanningTimeout(const std::optional< ApInfo > &bestAp)
This method is called after wait beacon timeout or wait probe request timeout has occurred.
a unique identifier for an interface.
Definition: type-id.h:59
TypeId SetParent(TypeId tid)
Set the parent TypeId.
Definition: type-id.cc:936
Abstract base class for the Association Manager, which manages scanning and association for single li...
const SortedList & GetSortedList() const
std::optional< std::reference_wrapper< const MultiLinkElement > > OptMleConstRef
typedef for an optional const reference to a MultiLinkElement object
virtual void NotifyApInfo(const StaWifiMac::ApInfo &&apInfo)
STA wifi MAC received a Beacon frame or Probe Response frame while scanning and notifies us the AP in...
Ptr< StaWifiMac > m_mac
pointer to the STA wifi MAC
virtual void DoStartScanning()=0
Start a scanning procedure.
void SetStaWifiMac(Ptr< StaWifiMac > mac)
Set the pointer to the STA wifi MAC.
std::list< std::pair< uint8_t, uint8_t > > & GetSetupLinks(const StaWifiMac::ApInfo &apInfo)
Get a reference to the list of the links to setup with the given AP.
void ScanningTimeout()
Extract the best AP to associate with from the sorted list and return it, if any, to the STA wifi MAC...
virtual bool CanBeInserted(const StaWifiMac::ApInfo &apInfo) const =0
Allow subclasses to choose whether the given ApInfo shall be considered and hence inserted in the sor...
std::optional< std::reference_wrapper< const ReducedNeighborReport > > OptRnrConstRef
typedef for an optional const reference to a ReducedNeighborReport object
SortedList m_apList
sorted list of candidate APs
static std::optional< WifiAssocManager::RnrLinkInfo > GetNextAffiliatedAp(const ReducedNeighborReport &rnr, std::size_t nbrApInfoId)
Search the given RNR element for APs affiliated to the same AP MLD as the reporting AP.
WifiScanParams m_scanParams
scanning parameters
virtual bool CanBeReturned(const StaWifiMac::ApInfo &apInfo) const =0
Allow subclasses to choose whether the given ApInfo shall be returned or discarded when the STA wifi ...
void StartScanning(WifiScanParams &&scanParams)
Request the Association Manager to start a scanning procedure according to the given scanning paramet...
std::set< StaWifiMac::ApInfo, ApInfoCompare > SortedList
typedef for the sorted list of ApInfo objects
static std::list< WifiAssocManager::RnrLinkInfo > GetAllAffiliatedAps(const ReducedNeighborReport &rnr)
Find all the APs affiliated to the same AP MLD as the reporting AP that sent the given RNR element.
static TypeId GetTypeId()
Get the type ID.
const WifiScanParams & GetScanParams() const
void DoDispose() override
Destructor implementation.
std::unordered_map< Mac48Address, SortedList::const_iterator, WifiAddressHash > m_apListIt
hash table to help locate ApInfo objects in the sorted list based on the BSSID
bool CanSetupMultiLink(OptMleConstRef &mle, OptRnrConstRef &rnr)
Check whether 11be Multi-Link setup can be established with the current best AP.
WifiAssocManager()
Constructor (protected as this is an abstract base class)
bool MatchScanParams(const StaWifiMac::ApInfo &apInfo) const
Check whether the given AP information match the current scanning parameters.
uint8_t GetNLinks() const
Get the number of links (can be greater than 1 for 11be devices only).
Definition: wifi-mac.cc:930
#define NS_ASSERT(condition)
At runtime, in debugging builds, if this condition is not true, the program prints the source file,...
Definition: assert.h:66
#define NS_ASSERT_MSG(condition, message)
At runtime, in debugging builds, if this condition is not true, the program prints the message to out...
Definition: assert.h:86
#define NS_LOG_COMPONENT_DEFINE(name)
Define a Log component with a specific name.
Definition: log.h:202
#define NS_LOG_DEBUG(msg)
Use NS_LOG to output a message of level LOG_DEBUG.
Definition: log.h:268
#define NS_LOG_FUNCTION(parameters)
If log level LOG_FUNCTION is enabled, this macro will output all input parameters separated by ",...
#define NS_OBJECT_ENSURE_REGISTERED(type)
Register an Object subclass with the TypeId system.
Definition: object-base.h:46
@ WIFI_PHY_BAND_UNSPECIFIED
Unspecified.
Definition: wifi-phy-band.h:43
Every class exported by the ns3 library is enclosed in the ns3 namespace.
Struct to hold information regarding observed AP through active/passive scanning.
Definition: sta-wifi-mac.h:164
MgtFrameType m_frame
The body of the management frame used to update AP info.
Definition: sta-wifi-mac.h:168
std::list< std::pair< uint8_t, uint8_t > > m_setupLinks
list of (local link ID, AP link ID) pairs identifying the links to setup between MLDs
Definition: sta-wifi-mac.h:172
WifiScanParams::Channel m_channel
The channel the management frame was received on.
Definition: sta-wifi-mac.h:169
uint8_t m_linkId
ID of the link used to communicate with the AP.
Definition: sta-wifi-mac.h:170
Mac48Address m_bssid
BSSID.
Definition: sta-wifi-mac.h:165
Struct providing a function call operator to compare two ApInfo objects.
ApInfoCompare(const WifiAssocManager &manager)
Constructor.
bool operator()(const StaWifiMac::ApInfo &lhs, const StaWifiMac::ApInfo &rhs) const
Function call operator.
WifiPhyBand band
PHY band.
Definition: sta-wifi-mac.h:72
uint16_t number
channel number
Definition: sta-wifi-mac.h:71
Structure holding scan parameters.
Definition: sta-wifi-mac.h:62
std::vector< ChannelList > channelList
list of channels to scan, for each link
Definition: sta-wifi-mac.h:80
Ssid ssid
desired SSID or wildcard SSID
Definition: sta-wifi-mac.h:79