| /* |
| * Copyright (c) 2016, The OpenThread Authors. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of the copyright holder nor the |
| * names of its contributors may be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** |
| * @file |
| * This file implements the Thread IPv6 global addresses configuration utilities. |
| */ |
| |
| #include "slaac_address.hpp" |
| |
| #if OPENTHREAD_CONFIG_IP6_SLAAC_ENABLE |
| |
| #include "common/array.hpp" |
| #include "common/code_utils.hpp" |
| #include "common/locator_getters.hpp" |
| #include "common/log.hpp" |
| #include "common/numeric_limits.hpp" |
| #include "common/random.hpp" |
| #include "common/settings.hpp" |
| #include "crypto/sha256.hpp" |
| #include "instance/instance.hpp" |
| #include "net/ip6_address.hpp" |
| |
| namespace ot { |
| namespace Utils { |
| |
| RegisterLogModule("Slaac"); |
| |
| Slaac::Slaac(Instance &aInstance) |
| : InstanceLocator(aInstance) |
| , mEnabled(true) |
| , mFilter(nullptr) |
| , mTimer(aInstance) |
| { |
| ClearAllBytes(mSlaacAddresses); |
| } |
| |
| void Slaac::Enable(void) |
| { |
| VerifyOrExit(!mEnabled); |
| |
| mEnabled = true; |
| LogInfo("Enabled"); |
| |
| AddAddresses(); |
| |
| exit: |
| return; |
| } |
| |
| void Slaac::Disable(void) |
| { |
| VerifyOrExit(mEnabled); |
| |
| RemoveAllAddresses(); |
| mTimer.Stop(); |
| |
| LogInfo("Disabled"); |
| mEnabled = false; |
| |
| exit: |
| return; |
| } |
| |
| void Slaac::SetFilter(PrefixFilter aFilter) |
| { |
| VerifyOrExit(aFilter != mFilter); |
| |
| mFilter = aFilter; |
| LogInfo("Filter %s", (mFilter != nullptr) ? "updated" : "disabled"); |
| |
| VerifyOrExit(mEnabled); |
| RemoveOrDeprecateAddresses(); |
| AddAddresses(); |
| |
| exit: |
| return; |
| } |
| |
| Error Slaac::FindDomainIdFor(const Ip6::Address &aAddress, uint8_t &aDomainId) const |
| { |
| Error error = kErrorNotFound; |
| |
| for (const SlaacAddress &slaacAddr : mSlaacAddresses) |
| { |
| if (!slaacAddr.IsInUse() || !slaacAddr.IsDeprecating()) |
| { |
| continue; |
| } |
| |
| if (aAddress.PrefixMatch(slaacAddr.GetAddress()) >= Ip6::NetworkPrefix::kLength) |
| { |
| aDomainId = slaacAddr.GetDomainId(); |
| error = kErrorNone; |
| break; |
| } |
| } |
| |
| return error; |
| } |
| |
| bool Slaac::IsSlaac(const NetworkData::OnMeshPrefixConfig &aConfig) const |
| { |
| return aConfig.mSlaac && !aConfig.mDp && (aConfig.GetPrefix().GetLength() == Ip6::NetworkPrefix::kLength); |
| } |
| |
| bool Slaac::IsFiltered(const NetworkData::OnMeshPrefixConfig &aConfig) const |
| { |
| return (mFilter != nullptr) ? mFilter(&GetInstance(), &aConfig.GetPrefix()) : false; |
| } |
| |
| void Slaac::HandleNotifierEvents(Events aEvents) |
| { |
| VerifyOrExit(mEnabled); |
| |
| if (aEvents.Contains(kEventThreadNetdataChanged)) |
| { |
| RemoveOrDeprecateAddresses(); |
| AddAddresses(); |
| ExitNow(); |
| } |
| |
| if (aEvents.Contains(kEventIp6AddressRemoved)) |
| { |
| // When an IPv6 address is removed, we ensure to check if a SLAAC address |
| // needs to be added (replacing the removed address). |
| // |
| // Note that if an address matching a newly added on-mesh prefix (with |
| // SLAAC flag) is already present (e.g., user previously added an address |
| // with same prefix), the SLAAC module will not add a SLAAC address with same |
| // prefix. So on IPv6 address removal event, we check if SLAAC module need |
| // to add any addresses. |
| |
| AddAddresses(); |
| } |
| |
| exit: |
| return; |
| } |
| |
| bool Slaac::DoesConfigMatchNetifAddr(const NetworkData::OnMeshPrefixConfig &aConfig, |
| const Ip6::Netif::UnicastAddress &aAddr) |
| { |
| return (((aConfig.mOnMesh && (aAddr.mPrefixLength == aConfig.mPrefix.mLength)) || |
| (!aConfig.mOnMesh && (aAddr.mPrefixLength == 128))) && |
| (aAddr.GetAddress().MatchesPrefix(aConfig.GetPrefix()))); |
| } |
| |
| void Slaac::RemoveOrDeprecateAddresses(void) |
| { |
| // Remove or deprecate any SLAAC addresses with no matching on-mesh |
| // prefix in Network Data. |
| |
| for (SlaacAddress &slaacAddr : mSlaacAddresses) |
| { |
| NetworkData::Iterator iterator; |
| NetworkData::OnMeshPrefixConfig config; |
| bool found = false; |
| |
| if (!slaacAddr.IsInUse()) |
| { |
| continue; |
| } |
| |
| iterator = NetworkData::kIteratorInit; |
| |
| while (Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, config) == kErrorNone) |
| { |
| if (IsSlaac(config) && DoesConfigMatchNetifAddr(config, slaacAddr)) |
| { |
| found = true; |
| break; |
| } |
| } |
| |
| if (found) |
| { |
| if (IsFiltered(config)) |
| { |
| RemoveAddress(slaacAddr); |
| } |
| } |
| else if (!slaacAddr.IsDeprecating()) |
| { |
| if (slaacAddr.mPreferred) |
| { |
| DeprecateAddress(slaacAddr); |
| } |
| else |
| { |
| RemoveAddress(slaacAddr); |
| } |
| } |
| } |
| } |
| |
| void Slaac::DeprecateAddress(SlaacAddress &aAddress) |
| { |
| LogAddress(kDeprecating, aAddress); |
| |
| aAddress.SetExpirationTime(TimerMilli::GetNow() + kDeprecationInterval); |
| mTimer.FireAtIfEarlier(aAddress.GetExpirationTime()); |
| |
| Get<ThreadNetif>().UpdatePreferredFlagOn(aAddress, false); |
| } |
| |
| void Slaac::RemoveAllAddresses(void) |
| { |
| for (SlaacAddress &slaacAddr : mSlaacAddresses) |
| { |
| if (slaacAddr.IsInUse()) |
| { |
| RemoveAddress(slaacAddr); |
| } |
| } |
| } |
| |
| void Slaac::RemoveAddress(SlaacAddress &aAddress) |
| { |
| LogAddress(kRemoving, aAddress); |
| |
| Get<ThreadNetif>().RemoveUnicastAddress(aAddress); |
| aAddress.MarkAsNotInUse(); |
| } |
| |
| void Slaac::AddAddresses(void) |
| { |
| NetworkData::Iterator iterator; |
| NetworkData::OnMeshPrefixConfig config; |
| |
| // Generate and add SLAAC addresses for any newly added on-mesh prefixes. |
| |
| iterator = NetworkData::kIteratorInit; |
| |
| while (Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, config) == kErrorNone) |
| { |
| bool found = false; |
| |
| if (!IsSlaac(config) || IsFiltered(config)) |
| { |
| continue; |
| } |
| |
| for (SlaacAddress &slaacAddr : mSlaacAddresses) |
| { |
| if (slaacAddr.IsInUse() && DoesConfigMatchNetifAddr(config, slaacAddr)) |
| { |
| if (slaacAddr.IsDeprecating() && config.mPreferred) |
| { |
| slaacAddr.MarkAsNotDeprecating(); |
| Get<ThreadNetif>().UpdatePreferredFlagOn(slaacAddr, true); |
| } |
| |
| found = true; |
| break; |
| } |
| } |
| |
| if (found) |
| { |
| continue; |
| } |
| |
| for (const Ip6::Netif::UnicastAddress &netifAddr : Get<ThreadNetif>().GetUnicastAddresses()) |
| { |
| if (DoesConfigMatchNetifAddr(config, netifAddr)) |
| { |
| found = true; |
| break; |
| } |
| } |
| |
| if (!found) |
| { |
| AddAddressFor(config); |
| } |
| } |
| } |
| |
| void Slaac::AddAddressFor(const NetworkData::OnMeshPrefixConfig &aConfig) |
| { |
| SlaacAddress *newAddress = nullptr; |
| uint8_t dadCounter = 0; |
| uint8_t domainId = 0; |
| |
| for (SlaacAddress &slaacAddr : mSlaacAddresses) |
| { |
| // If all address entries are in-use, and we have any |
| // deprecating addresses, we select one with earliest |
| // expiration time. |
| |
| if (!slaacAddr.IsInUse()) |
| { |
| newAddress = &slaacAddr; |
| break; |
| } |
| |
| if (slaacAddr.IsDeprecating()) |
| { |
| if ((newAddress == nullptr) || slaacAddr.GetExpirationTime() < newAddress->GetExpirationTime()) |
| { |
| newAddress = &slaacAddr; |
| } |
| } |
| } |
| |
| if (newAddress == nullptr) |
| { |
| LogWarn("Failed to add - already have max %u addresses", kNumSlaacAddresses); |
| ExitNow(); |
| } |
| |
| if (newAddress->IsInUse()) |
| { |
| RemoveAddress(*newAddress); |
| } |
| |
| newAddress->MarkAsNotDeprecating(); |
| newAddress->InitAsSlaacOrigin(aConfig.mOnMesh ? aConfig.GetPrefix().mLength : 128, aConfig.mPreferred); |
| newAddress->GetAddress().SetPrefix(aConfig.GetPrefix()); |
| |
| IgnoreError(Get<NetworkData::Leader>().FindDomainIdFor(aConfig.GetPrefix(), domainId)); |
| newAddress->SetDomainId(domainId); |
| |
| IgnoreError(GenerateIid(*newAddress, dadCounter)); |
| |
| LogAddress(kAdding, *newAddress); |
| |
| Get<ThreadNetif>().AddUnicastAddress(*newAddress); |
| |
| exit: |
| return; |
| } |
| |
| void Slaac::HandleTimer(void) |
| { |
| TimeMilli now = TimerMilli::GetNow(); |
| TimeMilli nextTime = now.GetDistantFuture(); |
| |
| for (SlaacAddress &slaacAddr : mSlaacAddresses) |
| { |
| if (!slaacAddr.IsInUse() || !slaacAddr.IsDeprecating()) |
| { |
| continue; |
| } |
| |
| if (slaacAddr.GetExpirationTime() <= now) |
| { |
| RemoveAddress(slaacAddr); |
| } |
| else |
| { |
| nextTime = Min(nextTime, slaacAddr.GetExpirationTime()); |
| } |
| } |
| |
| if (nextTime != now.GetDistantFuture()) |
| { |
| mTimer.FireAtIfEarlier(nextTime); |
| } |
| } |
| |
| Error Slaac::GenerateIid(Ip6::Netif::UnicastAddress &aAddress, uint8_t &aDadCounter) const |
| { |
| /* |
| * This method generates a semantically opaque IID per RFC 7217. |
| * |
| * RID = F(Prefix, Net_Iface, Network_ID, DAD_Counter, secret_key) |
| * |
| * - RID is random (but stable) Identifier. |
| * - For pseudo-random function `F()` SHA-256 is used in this method. |
| * - `Net_Iface` is set to constant string "wpan". |
| * - `Network_ID` is not used (optional per RFC 7217). |
| * - The `secret_key` is randomly generated on first use (using true |
| * random number generator) and saved in non-volatile settings for |
| * future use. |
| * |
| */ |
| |
| Error error = kErrorFailed; |
| const uint8_t netIface[] = {'w', 'p', 'a', 'n'}; |
| IidSecretKey secretKey; |
| Crypto::Sha256 sha256; |
| Crypto::Sha256::Hash hash; |
| |
| static_assert(sizeof(hash) >= Ip6::InterfaceIdentifier::kSize, |
| "SHA-256 hash size is too small to use as IPv6 address IID"); |
| |
| GetIidSecretKey(secretKey); |
| |
| for (uint16_t count = 0; count < kMaxIidCreationAttempts; count++, aDadCounter++) |
| { |
| sha256.Start(); |
| sha256.Update(aAddress.mAddress.mFields.m8, BytesForBitSize(aAddress.mPrefixLength)); |
| |
| sha256.Update(netIface); |
| sha256.Update(aDadCounter); |
| sha256.Update(secretKey); |
| sha256.Finish(hash); |
| |
| aAddress.GetAddress().GetIid().SetBytes(hash.GetBytes()); |
| |
| // If the IID is reserved, try again with a new dadCounter |
| if (aAddress.GetAddress().GetIid().IsReserved()) |
| { |
| continue; |
| } |
| |
| // Exit and return the address if the IID is not reserved, |
| ExitNow(error = kErrorNone); |
| } |
| |
| LogWarn("Failed to generate a non-reserved IID after %d attempts", kMaxIidCreationAttempts); |
| |
| exit: |
| return error; |
| } |
| |
| #if OT_SHOULD_LOG_AT(OT_LOG_LEVEL_INFO) |
| void Slaac::LogAddress(Action aAction, const SlaacAddress &aAddress) |
| { |
| static const char *const kActionStrings[] = { |
| "Adding", // (0) kAdding |
| "Removing", // (1) kRemoving |
| "Deprecating", // (2) kDeprecating |
| }; |
| |
| static_assert(kAdding == 0, "kAdding value is incorrect"); |
| static_assert(kRemoving == 1, "kRemoving value is incorrect"); |
| static_assert(kDeprecating == 2, "kDeprecating value is incorrect"); |
| |
| LogInfo("%s %s", kActionStrings[aAction], aAddress.GetAddress().ToString().AsCString()); |
| } |
| #else |
| void Slaac::LogAddress(Action, const SlaacAddress &) {} |
| #endif |
| |
| void Slaac::GetIidSecretKey(IidSecretKey &aKey) const |
| { |
| Error error; |
| |
| error = Get<Settings>().Read<Settings::SlaacIidSecretKey>(aKey); |
| VerifyOrExit(error != kErrorNone); |
| |
| // If there is no previously saved secret key, generate |
| // a random one and save it. |
| |
| error = Random::Crypto::Fill(aKey); |
| |
| if (error != kErrorNone) |
| { |
| IgnoreError(Random::Crypto::Fill(aKey)); |
| } |
| |
| IgnoreError(Get<Settings>().Save<Settings::SlaacIidSecretKey>(aKey)); |
| |
| LogInfo("Generated and saved secret key"); |
| |
| exit: |
| return; |
| } |
| |
| } // namespace Utils |
| } // namespace ot |
| |
| #endif // OPENTHREAD_CONFIG_IP6_SLAAC_ENABLE |
