| /* |
| * 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/instance.hpp" |
| #include "common/locator_getters.hpp" |
| #include "common/log.hpp" |
| #include "common/random.hpp" |
| #include "common/settings.hpp" |
| #include "crypto/sha256.hpp" |
| #include "net/ip6_address.hpp" |
| |
| namespace ot { |
| namespace Utils { |
| |
| RegisterLogModule("Slaac"); |
| |
| Slaac::Slaac(Instance &aInstance) |
| : InstanceLocator(aInstance) |
| , mEnabled(true) |
| , mFilter(nullptr) |
| { |
| memset(mAddresses, 0, sizeof(mAddresses)); |
| } |
| |
| void Slaac::Enable(void) |
| { |
| VerifyOrExit(!mEnabled); |
| |
| LogInfo("Enabling"); |
| mEnabled = true; |
| Update(kModeAdd); |
| |
| exit: |
| return; |
| } |
| |
| void Slaac::Disable(void) |
| { |
| VerifyOrExit(mEnabled); |
| |
| LogInfo("Disabling"); |
| mEnabled = false; |
| Update(kModeRemove); |
| |
| exit: |
| return; |
| } |
| |
| void Slaac::SetFilter(otIp6SlaacPrefixFilter aFilter) |
| { |
| VerifyOrExit(aFilter != mFilter); |
| |
| mFilter = aFilter; |
| LogInfo("Filter %s", (mFilter != nullptr) ? "updated" : "disabled"); |
| |
| VerifyOrExit(mEnabled); |
| Update(kModeAdd | kModeRemove); |
| |
| exit: |
| return; |
| } |
| |
| bool Slaac::ShouldFilter(const Ip6::Prefix &aPrefix) const |
| { |
| return (mFilter != nullptr) && mFilter(&GetInstance(), &aPrefix); |
| } |
| |
| void Slaac::HandleNotifierEvents(Events aEvents) |
| { |
| UpdateMode mode = kModeNone; |
| |
| VerifyOrExit(mEnabled); |
| |
| if (aEvents.Contains(kEventThreadNetdataChanged)) |
| { |
| mode |= kModeAdd | kModeRemove; |
| } |
| |
| 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. |
| |
| mode |= kModeAdd; |
| } |
| |
| if (mode != kModeNone) |
| { |
| Update(mode); |
| } |
| |
| 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::Update(UpdateMode aMode) |
| { |
| NetworkData::Iterator iterator; |
| NetworkData::OnMeshPrefixConfig config; |
| bool found; |
| |
| if (aMode & kModeRemove) |
| { |
| // If enabled, remove any SLAAC addresses with no matching on-mesh prefix, |
| // otherwise (when disabled) remove all previously added SLAAC addresses. |
| |
| for (Ip6::Netif::UnicastAddress &slaacAddr : mAddresses) |
| { |
| if (!slaacAddr.mValid) |
| { |
| continue; |
| } |
| |
| found = false; |
| |
| if (mEnabled) |
| { |
| iterator = NetworkData::kIteratorInit; |
| |
| while (Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, config) == kErrorNone) |
| { |
| if (config.mDp) |
| { |
| // Skip domain prefix which is processed in MLE. |
| continue; |
| } |
| |
| if (config.mSlaac && !ShouldFilter(config.GetPrefix()) && |
| DoesConfigMatchNetifAddr(config, slaacAddr)) |
| { |
| found = true; |
| break; |
| } |
| } |
| } |
| |
| if (!found) |
| { |
| LogInfo("Removing address %s", slaacAddr.GetAddress().ToString().AsCString()); |
| |
| Get<ThreadNetif>().RemoveUnicastAddress(slaacAddr); |
| slaacAddr.mValid = false; |
| } |
| } |
| } |
| |
| if ((aMode & kModeAdd) && mEnabled) |
| { |
| // Generate and add SLAAC addresses for any newly added on-mesh prefixes. |
| |
| iterator = NetworkData::kIteratorInit; |
| |
| while (Get<NetworkData::Leader>().GetNextOnMeshPrefix(iterator, config) == kErrorNone) |
| { |
| Ip6::Prefix &prefix = config.GetPrefix(); |
| |
| if (config.mDp || !config.mSlaac || ShouldFilter(prefix)) |
| { |
| continue; |
| } |
| |
| found = false; |
| |
| for (const Ip6::Netif::UnicastAddress &netifAddr : Get<ThreadNetif>().GetUnicastAddresses()) |
| { |
| if (DoesConfigMatchNetifAddr(config, netifAddr)) |
| { |
| found = true; |
| break; |
| } |
| } |
| |
| if (!found) |
| { |
| bool added = false; |
| |
| for (Ip6::Netif::UnicastAddress &slaacAddr : mAddresses) |
| { |
| if (slaacAddr.mValid) |
| { |
| continue; |
| } |
| |
| slaacAddr.InitAsSlaacOrigin(config.mOnMesh ? prefix.mLength : 128, config.mPreferred); |
| slaacAddr.GetAddress().SetPrefix(prefix); |
| |
| IgnoreError(GenerateIid(slaacAddr)); |
| |
| LogInfo("Adding address %s", slaacAddr.GetAddress().ToString().AsCString()); |
| |
| Get<ThreadNetif>().AddUnicastAddress(slaacAddr); |
| |
| added = true; |
| break; |
| } |
| |
| if (!added) |
| { |
| LogWarn("Failed to add - max %d addresses supported and already in use", |
| GetArrayLength(mAddresses)); |
| } |
| } |
| } |
| } |
| } |
| |
| Error Slaac::GenerateIid(Ip6::Netif::UnicastAddress &aAddress, |
| uint8_t * aNetworkId, |
| uint8_t aNetworkIdLength, |
| 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 if `aNetworkId` is `nullptr` (optional per RF-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'}; |
| uint8_t dadCounter = aDadCounter ? *aDadCounter : 0; |
| 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++, dadCounter++) |
| { |
| sha256.Start(); |
| sha256.Update(aAddress.mAddress.mFields.m8, BitVectorBytes(aAddress.mPrefixLength)); |
| |
| if (aNetworkId) |
| { |
| sha256.Update(aNetworkId, aNetworkIdLength); |
| } |
| |
| sha256.Update(netIface); |
| sha256.Update(dadCounter); |
| 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; |
| } |
| |
| if (aDadCounter) |
| { |
| *aDadCounter = dadCounter; |
| } |
| |
| // 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; |
| } |
| |
| 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::FillBuffer(aKey.m8, sizeof(IidSecretKey)); |
| |
| if (error != kErrorNone) |
| { |
| IgnoreError(Random::Crypto::FillBuffer(aKey.m8, sizeof(IidSecretKey))); |
| } |
| |
| 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 |