1 /*
2  *  Copyright (c) 2018, The OpenThread Authors.
3  *  All rights reserved.
4  *
5  *  Redistribution and use in source and binary forms, with or without
6  *  modification, are permitted provided that the following conditions are met:
7  *  1. Redistributions of source code must retain the above copyright
8  *     notice, this list of conditions and the following disclaimer.
9  *  2. Redistributions in binary form must reproduce the above copyright
10  *     notice, this list of conditions and the following disclaimer in the
11  *     documentation and/or other materials provided with the distribution.
12  *  3. Neither the name of the copyright holder nor the
13  *     names of its contributors may be used to endorse or promote products
14  *     derived from this software without specific prior written permission.
15  *
16  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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25  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  *  POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #ifndef ROUTER_TABLE_HPP_
30 #define ROUTER_TABLE_HPP_
31 
32 #include "openthread-core-config.h"
33 
34 #if OPENTHREAD_FTD
35 
36 #include "common/encoding.hpp"
37 #include "common/iterator_utils.hpp"
38 #include "common/locator.hpp"
39 #include "common/non_copyable.hpp"
40 #include "mac/mac_types.hpp"
41 #include "thread/mle_types.hpp"
42 #include "thread/thread_tlvs.hpp"
43 #include "thread/topology.hpp"
44 
45 namespace ot {
46 
47 class RouterTable : public InstanceLocator, private NonCopyable
48 {
49     friend class NeighborTable;
50     class IteratorBuilder;
51 
52 public:
53     /**
54      * This class represents an iterator for iterating through entries in the router table.
55      *
56      */
57     class Iterator : public InstanceLocator, public ItemPtrIterator<Router, Iterator>
58     {
59         friend class ItemPtrIterator<Router, Iterator>;
60         friend class IteratorBuilder;
61 
62     public:
63         /**
64          * This constructor initializes an `Iterator` instance to start from beginning of the router table.
65          *
66          * @param[in] aInstance  A reference to the OpenThread instance.
67          *
68          */
69         explicit Iterator(Instance &aInstance);
70 
71     private:
72         enum IteratorType : uint8_t
73         {
74             kEndIterator,
75         };
76 
Iterator(Instance & aInstance,IteratorType)77         Iterator(Instance &aInstance, IteratorType)
78             : InstanceLocator(aInstance)
79         {
80         }
81 
82         void Advance(void);
83     };
84 
85     /**
86      * Constructor.
87      *
88      * @param[in]  aInstance  A reference to the OpenThread instance.
89      *
90      */
91     explicit RouterTable(Instance &aInstance);
92 
93     /**
94      * This method clears the router table.
95      *
96      */
97     void Clear(void);
98 
99     /**
100      * This method removes all neighbor links to routers.
101      *
102      */
103     void ClearNeighbors(void);
104 
105     /**
106      * This method allocates a router with a random router id.
107      *
108      * @returns A pointer to the allocated router or nullptr if a router ID is not available.
109      *
110      */
111     Router *Allocate(void);
112 
113     /**
114      * This method allocates a router with a specified router id.
115      *
116      * @returns A pointer to the allocated router or nullptr if the router id could not be allocated.
117      *
118      */
119     Router *Allocate(uint8_t aRouterId);
120 
121     /**
122      * This method releases a router id.
123      *
124      * @param[in]  aRouterId  The router id.
125      *
126      * @retval kErrorNone          Successfully released the router id.
127      * @retval kErrorInvalidState  The device is not currently operating as a leader.
128      * @retval kErrorNotFound      The router id is not currently allocated.
129      *
130      */
131     Error Release(uint8_t aRouterId);
132 
133     /**
134      * This method removes a router link.
135      *
136      * @param[in]  aRouter  A reference to the router.
137      *
138      */
139     void RemoveRouterLink(Router &aRouter);
140 
141     /**
142      * This method returns the number of active routers in the Thread network.
143      *
144      * @returns The number of active routers in the Thread network.
145      *
146      */
GetActiveRouterCount(void) const147     uint8_t GetActiveRouterCount(void) const { return mActiveRouterCount; }
148 
149     /**
150      * This method returns the number of active links with neighboring routers.
151      *
152      * @returns The number of active links with neighboring routers.
153      *
154      */
155     uint8_t GetActiveLinkCount(void) const;
156 
157     /**
158      * This method returns the leader in the Thread network.
159      *
160      * @returns A pointer to the Leader in the Thread network.
161      *
162      */
163     Router *GetLeader(void);
164 
165     /**
166      * This method returns the time in seconds since the last Router ID Sequence update.
167      *
168      * @returns The time in seconds since the last Router ID Sequence update.
169      *
170      */
171     uint32_t GetLeaderAge(void) const;
172 
173     /**
174      * This method returns the link cost for a neighboring router.
175      *
176      * @param[in]  aRouter  A reference to the router.
177      *
178      * @returns The link cost.
179      *
180      */
181     uint8_t GetLinkCost(Router &aRouter);
182 
183     /**
184      * This method returns the neighbor for a given RLOC16.
185      *
186      * @param[in]  aRloc16  The RLOC16 value.
187      *
188      * @returns A pointer to the router or nullptr if the router could not be found.
189      *
190      */
191     Router *GetNeighbor(uint16_t aRloc16);
192 
193     /**
194      * This method returns the neighbor for a given IEEE Extended Address.
195      *
196      * @param[in]  aExtAddress  A reference to the IEEE Extended Address.
197      *
198      * @returns A pointer to the router or nullptr if the router could not be found.
199      *
200      */
201     Router *GetNeighbor(const Mac::ExtAddress &aExtAddress);
202 
203     /**
204      * This method returns the neighbor for a given MAC address.
205      *
206      * @param[in]  aMacAddress  A MAC address
207      *
208      * @returns A pointer to the router or nullptr if the router could not be found.
209      *
210      */
211     Router *GetNeighbor(const Mac::Address &aMacAddress);
212 
213     /**
214      * This method returns the router for a given router id.
215      *
216      * @param[in]  aRouterId  The router id.
217      *
218      * @returns A pointer to the router or nullptr if the router could not be found.
219      *
220      */
GetRouter(uint8_t aRouterId)221     Router *GetRouter(uint8_t aRouterId)
222     {
223         return const_cast<Router *>(const_cast<const RouterTable *>(this)->GetRouter(aRouterId));
224     }
225 
226     /**
227      * This method returns the router for a given router id.
228      *
229      * @param[in]  aRouterId  The router id.
230      *
231      * @returns A pointer to the router or nullptr if the router could not be found.
232      *
233      */
234     const Router *GetRouter(uint8_t aRouterId) const;
235 
236     /**
237      * This method returns the router for a given IEEE Extended Address.
238      *
239      * @param[in]  aExtAddress  A reference to the IEEE Extended Address.
240      *
241      * @returns A pointer to the router or nullptr if the router could not be found.
242      *
243      */
244     Router *GetRouter(const Mac::ExtAddress &aExtAddress);
245 
246     /**
247      * This method returns if the router table contains a given `Neighbor` instance.
248      *
249      * @param[in]  aNeighbor  A reference to a `Neighbor`.
250      *
251      * @retval TRUE  if @p aNeighbor is a `Router` in the router table.
252      * @retval FALSE if @p aNeighbor is not a `Router` in the router table
253      *               (i.e. mParent, mParentCandidate, a `Child` of the child table).
254      *
255      */
Contains(const Neighbor & aNeighbor) const256     bool Contains(const Neighbor &aNeighbor) const
257     {
258         return mRouters <= &static_cast<const Router &>(aNeighbor) &&
259                &static_cast<const Router &>(aNeighbor) < mRouters + Mle::kMaxRouters;
260     }
261 
262     /**
263      * This method retains diagnostic information for a given router.
264      *
265      * @param[in]   aRouterId    The router ID or RLOC16 for a given router.
266      * @param[out]  aRouterInfo  The router information.
267      *
268      * @retval kErrorNone          Successfully retrieved the router info for given id.
269      * @retval kErrorInvalidArgs   @p aRouterId is not a valid value for a router.
270      * @retval kErrorNotFound      No router entry with the given id.
271      *
272      */
273     Error GetRouterInfo(uint16_t aRouterId, Router::Info &aRouterInfo);
274 
275     /**
276      * This method returns the Router ID Sequence.
277      *
278      * @returns The Router ID Sequence.
279      *
280      */
GetRouterIdSequence(void) const281     uint8_t GetRouterIdSequence(void) const { return mRouterIdSequence; }
282 
283     /**
284      * This method returns the local time when the Router ID Sequence was last updated.
285      *
286      * @returns The local time when the Router ID Sequence was last updated.
287      *
288      */
GetRouterIdSequenceLastUpdated(void) const289     TimeMilli GetRouterIdSequenceLastUpdated(void) const { return mRouterIdSequenceLastUpdated; }
290 
291     /**
292      * This method returns the number of neighbor links.
293      *
294      * @returns The number of neighbor links.
295      *
296      */
297     uint8_t GetNeighborCount(void) const;
298 
299     /**
300      * This method indicates whether or not @p aRouterId is allocated.
301      *
302      * @retval TRUE if @p aRouterId is allocated.
303      * @retval FALSE if @p aRouterId is not allocated.
304      *
305      */
306     bool IsAllocated(uint8_t aRouterId) const;
307 
308     /**
309      * This method updates the Router ID allocation.
310      *
311      * @param[in]  aRouterIdSequence  The Router Id Sequence.
312      * @param[in]  aRouterIdSet       A reference to the Router Id Set.
313      *
314      */
315     void UpdateRouterIdSet(uint8_t aRouterIdSequence, const Mle::RouterIdSet &aRouterIdSet);
316 
317     /**
318      * This method gets the allocated Router ID set.
319      *
320      * @returns The allocated Router ID set.
321      *
322      */
GetRouterIdSet(void) const323     const Mle::RouterIdSet &GetRouterIdSet(void) const { return mAllocatedRouterIds; }
324 
325     /**
326      * This method updates the router table and must be called with a one second period.
327      *
328      */
329     void HandleTimeTick(void);
330 
331     /**
332      * This method enables range-based `for` loop iteration over all Router entries in the Router table.
333      *
334      * This method should be used as follows:
335      *
336      *     for (Router &router : Get<RouterTable>().Iterate()) { ... }
337      *
338      * @returns An `IteratorBuilder` instance.
339      *
340      */
Iterate(void)341     IteratorBuilder Iterate(void) { return IteratorBuilder(GetInstance()); }
342 
343 private:
344     class IteratorBuilder : public InstanceLocator
345     {
346     public:
IteratorBuilder(Instance & aInstance)347         explicit IteratorBuilder(Instance &aInstance)
348             : InstanceLocator(aInstance)
349         {
350         }
351 
begin(void)352         Iterator begin(void) { return Iterator(GetInstance()); }
end(void)353         Iterator end(void) { return Iterator(GetInstance(), Iterator::kEndIterator); }
354     };
355 
356     void          UpdateAllocation(void);
357     const Router *GetFirstEntry(void) const;
358     const Router *GetNextEntry(const Router *aRouter) const;
GetFirstEntry(void)359     Router *GetFirstEntry(void) { return const_cast<Router *>(const_cast<const RouterTable *>(this)->GetFirstEntry()); }
GetNextEntry(Router * aRouter)360     Router *GetNextEntry(Router *aRouter)
361     {
362         return const_cast<Router *>(const_cast<const RouterTable *>(this)->GetNextEntry(aRouter));
363     }
364 
365     const Router *FindRouter(const Router::AddressMatcher &aMatcher) const;
FindRouter(const Router::AddressMatcher & aMatcher)366     Router *      FindRouter(const Router::AddressMatcher &aMatcher)
367     {
368         return const_cast<Router *>(const_cast<const RouterTable *>(this)->FindRouter(aMatcher));
369     }
370 
371     Router           mRouters[Mle::kMaxRouters];
372     Mle::RouterIdSet mAllocatedRouterIds;
373     uint8_t          mRouterIdReuseDelay[Mle::kMaxRouterId + 1];
374     TimeMilli        mRouterIdSequenceLastUpdated;
375     uint8_t          mRouterIdSequence;
376     uint8_t          mActiveRouterCount;
377 };
378 
379 } // namespace ot
380 
381 #endif // OPENTHREAD_FTD
382 
383 #endif // ROUTER_TABLE_HPP_
384