Refactor MessageFactory

While we're here, also drop struct keywords where we use Linux structures.

Bug: 162032964
Test: canhalctrl up test virtual vcan3
Change-Id: Ib629cad3d2203b998668f45534699292863cadd9
diff --git a/automotive/can/1.0/default/libnetdevice/can.cpp b/automotive/can/1.0/default/libnetdevice/can.cpp
index 5a1105c..083f4f0 100644
--- a/automotive/can/1.0/default/libnetdevice/can.cpp
+++ b/automotive/can/1.0/default/libnetdevice/can.cpp
@@ -34,7 +34,7 @@
 static constexpr can_err_mask_t kErrMask = CAN_ERR_MASK;
 
 base::unique_fd socket(const std::string& ifname) {
-    struct sockaddr_can addr = {};
+    sockaddr_can addr = {};
     addr.can_family = AF_CAN;
     addr.can_ifindex = nametoindex(ifname);
     if (addr.can_ifindex == 0) {
@@ -58,7 +58,7 @@
         return {};
     }
 
-    if (0 != bind(sock.get(), reinterpret_cast<struct sockaddr*>(&addr), sizeof(addr))) {
+    if (0 != bind(sock.get(), reinterpret_cast<sockaddr*>(&addr), sizeof(addr))) {
         LOG(ERROR) << "Can't bind to CAN interface " << ifname;
         return {};
     }
@@ -67,26 +67,25 @@
 }
 
 bool setBitrate(std::string ifname, uint32_t bitrate) {
-    struct can_bittiming bt = {};
+    can_bittiming bt = {};
     bt.bitrate = bitrate;
 
-    nl::MessageFactory<struct ifinfomsg> req(RTM_NEWLINK, NLM_F_REQUEST | NLM_F_ACK);
+    nl::MessageFactory<ifinfomsg> req(RTM_NEWLINK, NLM_F_REQUEST | NLM_F_ACK);
 
-    const auto ifidx = nametoindex(ifname);
-    if (ifidx == 0) {
+    req->ifi_index = nametoindex(ifname);
+    if (req->ifi_index == 0) {
         LOG(ERROR) << "Can't find interface " << ifname;
         return false;
     }
-    req.data().ifi_index = ifidx;
 
     {
-        auto linkinfo = req.nest(IFLA_LINKINFO);
-        req.addattr(IFLA_INFO_KIND, "can");
+        auto linkinfo = req.addNested(IFLA_LINKINFO);
+        req.add(IFLA_INFO_KIND, "can");
         {
-            auto infodata = req.nest(IFLA_INFO_DATA);
+            auto infodata = req.addNested(IFLA_INFO_DATA);
             /* For CAN FD, it would require to add IFLA_CAN_DATA_BITTIMING
              * and IFLA_CAN_CTRLMODE as well. */
-            req.addattr(IFLA_CAN_BITTIMING, bt);
+            req.add(IFLA_CAN_BITTIMING, bt);
         }
     }
 
diff --git a/automotive/can/1.0/default/libnetdevice/libnetdevice.cpp b/automotive/can/1.0/default/libnetdevice/libnetdevice.cpp
index e2ba2cb..9447c0c 100644
--- a/automotive/can/1.0/default/libnetdevice/libnetdevice.cpp
+++ b/automotive/can/1.0/default/libnetdevice/libnetdevice.cpp
@@ -62,13 +62,13 @@
 }
 
 bool add(std::string dev, std::string type) {
-    nl::MessageFactory<struct ifinfomsg> req(RTM_NEWLINK,
-                                             NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL | NLM_F_ACK);
-    req.addattr(IFLA_IFNAME, dev);
+    nl::MessageFactory<ifinfomsg> req(RTM_NEWLINK,
+                                      NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL | NLM_F_ACK);
+    req.add(IFLA_IFNAME, dev);
 
     {
-        auto linkinfo = req.nest(IFLA_LINKINFO);
-        req.addattr(IFLA_INFO_KIND, type);
+        auto linkinfo = req.addNested(IFLA_LINKINFO);
+        req.add(IFLA_INFO_KIND, type);
     }
 
     nl::Socket sock(NETLINK_ROUTE);
@@ -76,8 +76,8 @@
 }
 
 bool del(std::string dev) {
-    nl::MessageFactory<struct ifinfomsg> req(RTM_DELLINK, NLM_F_REQUEST | NLM_F_ACK);
-    req.addattr(IFLA_IFNAME, dev);
+    nl::MessageFactory<ifinfomsg> req(RTM_DELLINK, NLM_F_REQUEST | NLM_F_ACK);
+    req.add(IFLA_IFNAME, dev);
 
     nl::Socket sock(NETLINK_ROUTE);
     return sock.send(req) && sock.receiveAck(req);
diff --git a/automotive/can/1.0/default/libnetdevice/vlan.cpp b/automotive/can/1.0/default/libnetdevice/vlan.cpp
index 33dc029..ee02f7b 100644
--- a/automotive/can/1.0/default/libnetdevice/vlan.cpp
+++ b/automotive/can/1.0/default/libnetdevice/vlan.cpp
@@ -33,18 +33,18 @@
         return false;
     }
 
-    nl::MessageFactory<struct ifinfomsg> req(RTM_NEWLINK,
-                                             NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL | NLM_F_ACK);
-    req.addattr(IFLA_IFNAME, vlan);
-    req.addattr<uint32_t>(IFLA_LINK, ethidx);
+    nl::MessageFactory<ifinfomsg> req(RTM_NEWLINK,
+                                      NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL | NLM_F_ACK);
+    req.add(IFLA_IFNAME, vlan);
+    req.add<uint32_t>(IFLA_LINK, ethidx);
 
     {
-        auto linkinfo = req.nest(IFLA_LINKINFO);
-        req.addattr(IFLA_INFO_KIND, "vlan");
+        auto linkinfo = req.addNested(IFLA_LINKINFO);
+        req.add(IFLA_INFO_KIND, "vlan");
 
         {
-            auto linkinfo = req.nest(IFLA_INFO_DATA);
-            req.addattr(IFLA_VLAN_ID, id);
+            auto linkinfo = req.addNested(IFLA_INFO_DATA);
+            req.add(IFLA_VLAN_ID, id);
         }
     }
 
diff --git a/automotive/can/1.0/default/libnl++/MessageFactory.cpp b/automotive/can/1.0/default/libnl++/MessageFactory.cpp
index 0c6a331..6f35897 100644
--- a/automotive/can/1.0/default/libnl++/MessageFactory.cpp
+++ b/automotive/can/1.0/default/libnl++/MessageFactory.cpp
@@ -17,41 +17,36 @@
 #include <libnl++/MessageFactory.h>
 
 #include <android-base/logging.h>
+#include <libnl++/bits.h>
 
-// for RTA_ macros missing from NLA_ definitions
-#include <linux/rtnetlink.h>
+namespace android::nl {
 
-namespace android::nl::impl {
-
-static struct nlattr* nlmsg_tail(struct nlmsghdr* n) {
-    return reinterpret_cast<struct nlattr*>(  //
-            reinterpret_cast<uintptr_t>(n) + NLMSG_ALIGN(n->nlmsg_len));
+static nlattr* tail(nlmsghdr* msg) {
+    return reinterpret_cast<nlattr*>(uintptr_t(msg) + impl::align(msg->nlmsg_len));
 }
 
-struct nlattr* addattr_l(struct nlmsghdr* n, size_t maxLen, nlattrtype_t type, const void* data,
-                         size_t dataLen) {
-    size_t newLen = NLMSG_ALIGN(n->nlmsg_len) + RTA_SPACE(dataLen);
+nlattr* MessageFactoryBase::add(nlmsghdr* msg, size_t maxLen, nlattrtype_t type, const void* data,
+                                size_t dataLen) {
+    const auto totalAttrLen = impl::space<nlattr>(dataLen);
+    const auto newLen = impl::align(msg->nlmsg_len) + totalAttrLen;
     if (newLen > maxLen) {
-        LOG(ERROR) << "addattr_l failed - exceeded maxLen: " << newLen << " > " << maxLen;
+        LOG(ERROR) << "Can't add attribute of size " << dataLen  //
+                   << " - exceeded maxLen: " << newLen << " > " << maxLen;
         return nullptr;
     }
 
-    auto attr = nlmsg_tail(n);
-    attr->nla_len = RTA_SPACE(dataLen);
+    auto attr = tail(msg);
+    attr->nla_len = totalAttrLen;
     attr->nla_type = type;
-    if (dataLen > 0) memcpy(RTA_DATA(attr), data, dataLen);
+    if (dataLen > 0) memcpy(impl::data<nlattr, void>(attr), data, dataLen);
 
-    n->nlmsg_len = newLen;
+    msg->nlmsg_len = newLen;
     return attr;
 }
 
-struct nlattr* addattr_nest(struct nlmsghdr* n, size_t maxLen, nlattrtype_t type) {
-    return addattr_l(n, maxLen, type, nullptr, 0);
+void MessageFactoryBase::closeNested(nlmsghdr* msg, nlattr* nested) {
+    if (nested == nullptr) return;
+    nested->nla_len = uintptr_t(tail(msg)) - uintptr_t(nested);
 }
 
-void addattr_nest_end(struct nlmsghdr* n, struct nlattr* nest) {
-    size_t nestLen = reinterpret_cast<uintptr_t>(nlmsg_tail(n)) - reinterpret_cast<uintptr_t>(nest);
-    nest->nla_len = nestLen;
-}
-
-}  // namespace android::nl::impl
+}  // namespace android::nl
diff --git a/automotive/can/1.0/default/libnl++/include/libnl++/Buffer.h b/automotive/can/1.0/default/libnl++/include/libnl++/Buffer.h
index a6f8f7a..c3137c8 100644
--- a/automotive/can/1.0/default/libnl++/include/libnl++/Buffer.h
+++ b/automotive/can/1.0/default/libnl++/include/libnl++/Buffer.h
@@ -17,6 +17,7 @@
 #pragma once
 
 #include <android-base/logging.h>
+#include <libnl++/bits.h>
 
 #include <linux/netlink.h>
 
@@ -25,7 +26,7 @@
 namespace android::nl {
 
 /**
- * Buffer wrapper containing netlink structure (e.g. struct nlmsghdr, struct nlattr).
+ * Buffer wrapper containing netlink structure (e.g. nlmsghdr, nlattr).
  *
  * This is a C++-style, memory safe(r) and generic implementation of linux/netlink.h macros.
  *
@@ -43,15 +44,6 @@
  */
 template <typename T>
 class Buffer {
-    // The following definitions are C++ equivalents of NLMSG_* macros from linux/netlink.h
-
-    static constexpr size_t alignto = NLMSG_ALIGNTO;
-    static_assert(NLMSG_ALIGNTO == NLA_ALIGNTO);
-
-    static constexpr size_t align(size_t ptr) { return (ptr + alignto - 1) & ~(alignto - 1); }
-
-    static constexpr size_t hdrlen = align(sizeof(T));
-
   public:
     /**
      * Constructs empty buffer of size 0.
@@ -96,9 +88,7 @@
 
     template <typename D>
     const Buffer<D> data(size_t offset = 0) const {
-        // Equivalent to NLMSG_DATA(hdr) + NLMSG_ALIGN(offset)
-        const D* dptr = reinterpret_cast<const D*>(uintptr_t(mData) + hdrlen + align(offset));
-        return {dptr, dataEnd()};
+        return {impl::data<const T, const D>(mData, offset), dataEnd()};
     }
 
     class iterator {
@@ -111,7 +101,7 @@
         iterator operator++() {
             // mBufferEnd stays the same
             mCurrent.mData = reinterpret_cast<const T*>(  //
-                    uintptr_t(mCurrent.mData) + align(mCurrent.declaredLength()));
+                    uintptr_t(mCurrent.mData) + impl::align(mCurrent.declaredLength()));
 
             return *this;
         }
diff --git a/automotive/can/1.0/default/libnl++/include/libnl++/MessageFactory.h b/automotive/can/1.0/default/libnl++/include/libnl++/MessageFactory.h
index 5272577..c3d72c5 100644
--- a/automotive/can/1.0/default/libnl++/include/libnl++/MessageFactory.h
+++ b/automotive/can/1.0/default/libnl++/include/libnl++/MessageFactory.h
@@ -17,6 +17,7 @@
 #pragma once
 
 #include <android-base/macros.h>
+#include <libnl++/Buffer.h>
 #include <libnl++/types.h>
 
 #include <linux/netlink.h>
@@ -25,131 +26,140 @@
 
 namespace android::nl {
 
-/** Implementation details, do not use outside MessageFactory template. */
-namespace impl {
-
-struct nlattr* addattr_l(struct nlmsghdr* n, size_t maxLen, nlattrtype_t type, const void* data,
-                         size_t dataLen);
-struct nlattr* addattr_nest(struct nlmsghdr* n, size_t maxLen, nlattrtype_t type);
-void addattr_nest_end(struct nlmsghdr* n, struct nlattr* nest);
-
-}  // namespace impl
+class MessageFactoryBase {
+  protected:
+    static nlattr* add(nlmsghdr* msg, size_t maxLen, nlattrtype_t type, const void* data,
+                       size_t dataLen);
+    static void closeNested(nlmsghdr* msg, nlattr* nested);
+};
 
 /**
  * Wrapper around NETLINK_ROUTE messages, to build them in C++ style.
  *
- * \param T specific message header (such as struct ifinfomsg)
- * \param BUFSIZE how much space to reserve for payload (not counting the header size)
+ * \param T Message payload type (such as ifinfomsg).
+ * \param BUFSIZE how much space to reserve for attributes.
  */
 template <class T, unsigned int BUFSIZE = 128>
-struct MessageFactory {
-    struct RequestData {
-        struct nlmsghdr nlmsg;
+class MessageFactory : private MessageFactoryBase {
+    struct alignas(NLMSG_ALIGNTO) Message {
+        nlmsghdr header;
         T data;
-        char buf[BUFSIZE];
+        uint8_t attributesBuffer[BUFSIZE];
     };
 
-    static constexpr size_t totalLength = sizeof(RequestData);
-
+  public:
     /**
      * Create empty message.
      *
-     * \param type Message type (such as RTM_NEWLINK)
-     * \param flags Message flags (such as NLM_F_REQUEST)
+     * \param type Message type (such as RTM_NEWLINK).
+     * \param flags Message flags (such as NLM_F_REQUEST).
      */
-    MessageFactory(nlmsgtype_t type, uint16_t flags) {
-        mRequest.nlmsg.nlmsg_len = NLMSG_LENGTH(sizeof(mRequest.data));
-        mRequest.nlmsg.nlmsg_type = type;
-        mRequest.nlmsg.nlmsg_flags = flags;
+    MessageFactory(nlmsgtype_t type, uint16_t flags)
+        : header(mMessage.header), data(mMessage.data) {
+        mMessage.header.nlmsg_len = offsetof(Message, attributesBuffer);
+        mMessage.header.nlmsg_type = type;
+        mMessage.header.nlmsg_flags = flags;
     }
 
-    /** \return pointer to raw netlink message header. */
-    struct nlmsghdr* header() {
-        return &mRequest.nlmsg;
-    }
-    /** Reference to message-specific header. */
-    T& data() { return mRequest.data; }
-
     /**
-     * Adds an attribute of a simple type.
+     * Netlink message header.
      *
-     * If this method fails (i.e. due to insufficient space), the message will be marked
-     * as bad (\see isGood).
+     * This is a generic Netlink header containing information such as message flags.
+     */
+    nlmsghdr& header;
+
+    /**
+     * Netlink message data.
+     *
+     * This is a payload specific to a given message type.
+     */
+    T& data;
+
+    T* operator->() { return &mMessage.data; }
+
+    /**
+     * Build netlink message.
+     *
+     * In fact, this operation is almost a no-op, since the factory builds the message in a single
+     * buffer, using native data structures.
+     *
+     * A likely failure case is when the BUFSIZE template parameter is too small to acommodate
+     * added attributes. In such a case, please increase this parameter.
+     *
+     * \return Netlink message or std::nullopt in case of failure.
+     */
+    std::optional<Buffer<nlmsghdr>> build() const {
+        if (!mIsGood) return std::nullopt;
+        return {{&mMessage.header, mMessage.header.nlmsg_len}};
+    }
+
+    /**
+     * Adds an attribute of a trivially copyable type.
+     *
+     * Template specializations may extend this function for other types, such as std::string.
+     *
+     * If this method fails (i.e. due to insufficient space), a warning will be printed to the log
+     * and the message will be marked as bad, causing later \see build call to fail.
      *
      * \param type attribute type (such as IFLA_IFNAME)
      * \param attr attribute data
      */
     template <class A>
-    void addattr(nlattrtype_t type, const A& attr) {
-        if (!mIsGood) return;
-        auto ap = impl::addattr_l(&mRequest.nlmsg, sizeof(mRequest), type, &attr, sizeof(attr));
-        if (ap == nullptr) mIsGood = false;
+    void add(nlattrtype_t type, const A& attr) {
+        add(type, &attr, sizeof(attr));
     }
 
     template <>
-    void addattr(nlattrtype_t type, const std::string& s) {
-        if (!mIsGood) return;
-        auto ap = impl::addattr_l(&mRequest.nlmsg, sizeof(mRequest), type, s.c_str(), s.size() + 1);
-        if (ap == nullptr) mIsGood = false;
+    void add(nlattrtype_t type, const std::string& s) {
+        add(type, s.c_str(), s.size() + 1);
     }
 
-    /** Guard class to frame nested attributes. See nest(int). */
-    struct Nest {
-        Nest(MessageFactory& req, nlattrtype_t type) : mReq(req), mAttr(req.nestStart(type)) {}
-        ~Nest() { mReq.nestEnd(mAttr); }
+    /** Guard class to frame nested attributes. \see addNested(nlattrtype_t). */
+    class [[nodiscard]] NestedGuard {
+      public:
+        NestedGuard(MessageFactory & req, nlattrtype_t type) : mReq(req), mAttr(req.add(type)) {}
+        ~NestedGuard() { closeNested(&mReq.mMessage.header, mAttr); }
 
       private:
         MessageFactory& mReq;
-        struct nlattr* mAttr;
+        nlattr* mAttr;
 
-        DISALLOW_COPY_AND_ASSIGN(Nest);
+        DISALLOW_COPY_AND_ASSIGN(NestedGuard);
     };
 
     /**
      * Add nested attribute.
      *
      * The returned object is a guard for auto-nesting children inside the argument attribute.
-     * When the Nest object goes out of scope, the nesting attribute is closed.
+     * When the guard object goes out of scope, the nesting attribute is closed.
      *
      * Example usage nesting IFLA_CAN_BITTIMING inside IFLA_INFO_DATA, which is nested
      * inside IFLA_LINKINFO:
-     *    MessageFactory<struct ifinfomsg> req(RTM_NEWLINK, NLM_F_REQUEST);
+     *    MessageFactory<ifinfomsg> req(RTM_NEWLINK, NLM_F_REQUEST);
      *    {
-     *        auto linkinfo = req.nest(IFLA_LINKINFO);
-     *        req.addattr(IFLA_INFO_KIND, "can");
+     *        auto linkinfo = req.addNested(IFLA_LINKINFO);
+     *        req.add(IFLA_INFO_KIND, "can");
      *        {
-     *            auto infodata = req.nest(IFLA_INFO_DATA);
-     *            req.addattr(IFLA_CAN_BITTIMING, bitTimingStruct);
+     *            auto infodata = req.addNested(IFLA_INFO_DATA);
+     *            req.add(IFLA_CAN_BITTIMING, bitTimingStruct);
      *        }
      *    }
      *    // use req
      *
      * \param type attribute type (such as IFLA_LINKINFO)
      */
-    Nest nest(int type) { return Nest(*this, type); }
-
-    /**
-     * Indicates, whether the message is in a good state.
-     *
-     * The bad state is usually a result of payload buffer being too small.
-     * You can modify BUFSIZE template parameter to fix this.
-     */
-    bool isGood() const { return mIsGood; }
+    NestedGuard addNested(nlattrtype_t type) { return {*this, type}; }
 
   private:
+    Message mMessage = {};
     bool mIsGood = true;
-    RequestData mRequest = {};
 
-    struct nlattr* nestStart(nlattrtype_t type) {
+    nlattr* add(nlattrtype_t type, const void* data = nullptr, size_t len = 0) {
         if (!mIsGood) return nullptr;
-        auto attr = impl::addattr_nest(&mRequest.nlmsg, sizeof(mRequest), type);
+        auto attr = MessageFactoryBase::add(&mMessage.header, sizeof(mMessage), type, data, len);
         if (attr == nullptr) mIsGood = false;
         return attr;
     }
-
-    void nestEnd(struct nlattr* nest) {
-        if (mIsGood && nest != nullptr) impl::addattr_nest_end(&mRequest.nlmsg, nest);
-    }
 };
 
 }  // namespace android::nl
diff --git a/automotive/can/1.0/default/libnl++/include/libnl++/Socket.h b/automotive/can/1.0/default/libnl++/include/libnl++/Socket.h
index 16b63f5..6a4e82e 100644
--- a/automotive/can/1.0/default/libnl++/include/libnl++/Socket.h
+++ b/automotive/can/1.0/default/libnl++/include/libnl++/Socket.h
@@ -76,13 +76,12 @@
      */
     template <typename T, unsigned BUFSIZE>
     bool send(MessageFactory<T, BUFSIZE>& req, const sockaddr_nl& sa) {
-        if (!req.isGood()) return false;
+        req.header.nlmsg_seq = mSeq + 1;
 
-        const auto nlmsg = req.header();
-        nlmsg->nlmsg_seq = mSeq + 1;
+        const auto msg = req.build();
+        if (!msg.has_value()) return false;
 
-        // With MessageFactory<>, we trust nlmsg_len to be correct.
-        return send({nlmsg, nlmsg->nlmsg_len}, sa);
+        return send(*msg, sa);
     }
 
     /**
@@ -156,7 +155,7 @@
      */
     template <typename T, unsigned BUFSIZE>
     bool receiveAck(MessageFactory<T, BUFSIZE>& req) {
-        return receiveAck(req.header()->nlmsg_seq);
+        return receiveAck(req.header.nlmsg_seq);
     }
 
     /**
diff --git a/automotive/can/1.0/default/libnl++/include/libnl++/bits.h b/automotive/can/1.0/default/libnl++/include/libnl++/bits.h
new file mode 100644
index 0000000..4c8f1aa
--- /dev/null
+++ b/automotive/can/1.0/default/libnl++/include/libnl++/bits.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <linux/netlink.h>
+
+namespace android::nl::impl {
+
+// The following definitions are C++ equivalents of NLMSG_* macros from linux/netlink.h.
+
+/**
+ * Equivalent to NLMSG_ALIGNTO.
+ */
+constexpr size_t alignto = NLMSG_ALIGNTO;
+static_assert(NLMSG_ALIGNTO == NLA_ALIGNTO);
+
+/**
+ * Equivalent to NLMSG_ALIGN(len).
+ */
+constexpr size_t align(size_t len) {
+    return (len + alignto - 1) & ~(alignto - 1);
+}
+
+/**
+ * Equivalent to NLMSG_SPACE(len).
+ */
+template <typename H>
+constexpr size_t space(size_t len) {
+    return align(align(sizeof(H)) + len);
+}
+
+/**
+ * Equivalent to NLMSG_DATA(hdr) + NLMSG_ALIGN(offset).
+ */
+template <typename H, typename D>
+constexpr D* data(H* header, size_t offset = 0) {
+    return reinterpret_cast<D*>(uintptr_t(header) + space<H>(offset));
+}
+
+}  // namespace android::nl::impl
diff --git a/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.cpp b/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.cpp
index 5203368..877bb21 100644
--- a/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.cpp
+++ b/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.cpp
@@ -22,10 +22,10 @@
         nlmsgtype_t msgtype, std::string msgname,
         const std::initializer_list<GenericCommandNameMap::value_type> commandNames,
         const std::initializer_list<AttributeMap::value_type> attrTypes)
-    : MessageDefinition<struct genlmsghdr>(msgname, {{msgtype, msgname}}, attrTypes),
+    : MessageDefinition<genlmsghdr>(msgname, {{msgtype, msgname}}, attrTypes),
       mCommandNames(commandNames) {}
 
-void GenericMessageBase::toStream(std::stringstream& ss, const struct genlmsghdr& data) const {
+void GenericMessageBase::toStream(std::stringstream& ss, const genlmsghdr& data) const {
     ss << "genlmsghdr{";
     if (mCommandNames.count(data.cmd) == 0) {
         ss << "cmd=" << unsigned(data.cmd);
diff --git a/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.h b/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.h
index f3b0b31..f0ee5b0 100644
--- a/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.h
+++ b/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.h
@@ -22,7 +22,7 @@
 
 namespace android::nl::protocols::generic {
 
-class GenericMessageBase : public MessageDefinition<struct genlmsghdr> {
+class GenericMessageBase : public MessageDefinition<genlmsghdr> {
   public:
     typedef std::map<uint8_t, std::string> GenericCommandNameMap;
 
@@ -31,7 +31,7 @@
             const std::initializer_list<GenericCommandNameMap::value_type> commandNames = {},
             const std::initializer_list<AttributeMap::value_type> attrTypes = {});
 
-    void toStream(std::stringstream& ss, const struct genlmsghdr& data) const override;
+    void toStream(std::stringstream& ss, const genlmsghdr& data) const override;
 
   private:
     const GenericCommandNameMap mCommandNames;
diff --git a/automotive/can/1.0/default/libnl++/protocols/route/Link.cpp b/automotive/can/1.0/default/libnl++/protocols/route/Link.cpp
index 26d3e3e..bc44d8e 100644
--- a/automotive/can/1.0/default/libnl++/protocols/route/Link.cpp
+++ b/automotive/can/1.0/default/libnl++/protocols/route/Link.cpp
@@ -25,7 +25,7 @@
 using DataType = AttributeDefinition::DataType;
 
 // clang-format off
-Link::Link() : MessageDefinition<struct ifinfomsg>("link", {
+Link::Link() : MessageDefinition<ifinfomsg>("link", {
     {RTM_NEWLINK, "NEWLINK"},
     {RTM_DELLINK, "DELLINK"},
     {RTM_GETLINK, "GETLINK"},
@@ -107,7 +107,7 @@
 }) {}
 // clang-format off
 
-void Link::toStream(std::stringstream& ss, const struct ifinfomsg& data) const {
+void Link::toStream(std::stringstream& ss, const ifinfomsg& data) const {
     ss << "ifinfomsg{"
        << "family=" << unsigned(data.ifi_family) << ", type=" << data.ifi_type
        << ", index=" << data.ifi_index << ", flags=" << data.ifi_flags
diff --git a/automotive/can/1.0/default/libnl++/protocols/route/Link.h b/automotive/can/1.0/default/libnl++/protocols/route/Link.h
index 4ea3eba..ecfefc9 100644
--- a/automotive/can/1.0/default/libnl++/protocols/route/Link.h
+++ b/automotive/can/1.0/default/libnl++/protocols/route/Link.h
@@ -22,10 +22,10 @@
 
 namespace android::nl::protocols::route {
 
-class Link : public MessageDefinition<struct ifinfomsg> {
+class Link : public MessageDefinition<ifinfomsg> {
   public:
     Link();
-    void toStream(std::stringstream& ss, const struct ifinfomsg& data) const override;
+    void toStream(std::stringstream& ss, const ifinfomsg& data) const override;
 };
 
 }  // namespace android::nl::protocols::route