Merge "Merge sc-dev-plus-aosp-without-vendor@7634622" into stage-aosp-master

1 files changed, 203 insertions, 0 deletions

diff --git a/automotive/can/1.0/default/libnl++/Socket.cpp b/automotive/can/1.0/default/libnl++/Socket.cpp
new file mode 100644
index 0000000000..514d9bb1b9
--- /dev/null
+++ b/automotive/can/1.0/default/libnl++/Socket.cpp
@@ -0,0 +1,203 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#include <libnl++/Socket.h>
+
+#include <libnl++/printer.h>
+
+#include <android-base/logging.h>
+
+namespace android::nl {
+
+/**
+ * Print all outbound/inbound Netlink messages.
+ */
+static constexpr bool kSuperVerbose = false;
+
+Socket::Socket(int protocol, unsigned pid, uint32_t groups) : mProtocol(protocol) {
+    mFd.reset(socket(AF_NETLINK, SOCK_RAW, protocol));
+    if (!mFd.ok()) {
+        PLOG(ERROR) << "Can't open Netlink socket";
+        mFailed = true;
+        return;
+    }
+
+    sockaddr_nl sa = {};
+    sa.nl_family = AF_NETLINK;
+    sa.nl_pid = pid;
+    sa.nl_groups = groups;
+
+    if (bind(mFd.get(), reinterpret_cast<sockaddr*>(&sa), sizeof(sa)) < 0) {
+        PLOG(ERROR) << "Can't bind Netlink socket";
+        mFd.reset();
+        mFailed = true;
+    }
+}
+
+bool Socket::send(const Buffer<nlmsghdr>& msg, const sockaddr_nl& sa) {
+    if constexpr (kSuperVerbose) {
+        LOG(VERBOSE) << (mFailed ? "(not) " : "") << "sending to " << sa.nl_pid << ": "
+                     << toString(msg, mProtocol);
+    }
+    if (mFailed) return false;
+
+    mSeq = msg->nlmsg_seq;
+    const auto rawMsg = msg.getRaw();
+    const auto bytesSent = sendto(mFd.get(), rawMsg.ptr(), rawMsg.len(), 0,
+                                  reinterpret_cast<const sockaddr*>(&sa), sizeof(sa));
+    if (bytesSent < 0) {
+        PLOG(ERROR) << "Can't send Netlink message";
+        return false;
+    } else if (size_t(bytesSent) != rawMsg.len()) {
+        LOG(ERROR) << "Can't send Netlink message: truncated message";
+        return false;
+    }
+    return true;
+}
+
+bool Socket::increaseReceiveBuffer(size_t maxSize) {
+    if (maxSize == 0) {
+        LOG(ERROR) << "Maximum receive size should not be zero";
+        return false;
+    }
+
+    if (mReceiveBuffer.size() < maxSize) mReceiveBuffer.resize(maxSize);
+    return true;
+}
+
+std::optional<Buffer<nlmsghdr>> Socket::receive(size_t maxSize) {
+    return receiveFrom(maxSize).first;
+}
+
+std::pair<std::optional<Buffer<nlmsghdr>>, sockaddr_nl> Socket::receiveFrom(size_t maxSize) {
+    if (mFailed) return {std::nullopt, {}};
+
+    if (!increaseReceiveBuffer(maxSize)) return {std::nullopt, {}};
+
+    sockaddr_nl sa = {};
+    socklen_t saLen = sizeof(sa);
+    const auto bytesReceived = recvfrom(mFd.get(), mReceiveBuffer.data(), maxSize, MSG_TRUNC,
+                                        reinterpret_cast<sockaddr*>(&sa), &saLen);
+
+    if (bytesReceived <= 0) {
+        PLOG(ERROR) << "Failed to receive Netlink message";
+        return {std::nullopt, {}};
+    } else if (size_t(bytesReceived) > maxSize) {
+        PLOG(ERROR) << "Received data larger than maximum receive size: "  //
+                    << bytesReceived << " > " << maxSize;
+        return {std::nullopt, {}};
+    }
+
+    Buffer<nlmsghdr> msg(reinterpret_cast<nlmsghdr*>(mReceiveBuffer.data()), bytesReceived);
+    if constexpr (kSuperVerbose) {
+        LOG(VERBOSE) << "received from " << sa.nl_pid << ": " << toString(msg, mProtocol);
+    }
+    return {msg, sa};
+}
+
+bool Socket::receiveAck(uint32_t seq) {
+    const auto nlerr = receive<nlmsgerr>({NLMSG_ERROR});
+    if (!nlerr.has_value()) return false;
+
+    if (nlerr->data.msg.nlmsg_seq != seq) {
+        LOG(ERROR) << "Received ACK for a different message (" << nlerr->data.msg.nlmsg_seq
+                   << ", expected " << seq << "). Multi-message tracking is not implemented.";
+        return false;
+    }
+
+    if (nlerr->data.error == 0) return true;
+
+    LOG(WARNING) << "Received Netlink error message: " << strerror(-nlerr->data.error);
+    return false;
+}
+
+std::optional<Buffer<nlmsghdr>> Socket::receive(const std::set<nlmsgtype_t>& msgtypes,
+                                                size_t maxSize) {
+    if (mFailed || !increaseReceiveBuffer(maxSize)) return std::nullopt;
+
+    for (const auto rawMsg : *this) {
+        if (msgtypes.count(rawMsg->nlmsg_type) == 0) {
+            LOG(WARNING) << "Received (and ignored) unexpected Netlink message of type "
+                         << rawMsg->nlmsg_type;
+            continue;
+        }
+
+        return rawMsg;
+    }
+
+    return std::nullopt;
+}
+
+std::optional<unsigned> Socket::getPid() {
+    if (mFailed) return std::nullopt;
+
+    sockaddr_nl sa = {};
+    socklen_t sasize = sizeof(sa);
+    if (getsockname(mFd.get(), reinterpret_cast<sockaddr*>(&sa), &sasize) < 0) {
+        PLOG(ERROR) << "Failed to get PID of Netlink socket";
+        return std::nullopt;
+    }
+    return sa.nl_pid;
+}
+
+pollfd Socket::preparePoll(short events) {
+    return {mFd.get(), events, 0};
+}
+
+Socket::receive_iterator::receive_iterator(Socket& socket, bool end)
+    : mSocket(socket), mIsEnd(end) {
+    if (!end) receive();
+}
+
+Socket::receive_iterator Socket::receive_iterator::operator++() {
+    CHECK(!mIsEnd) << "Trying to increment end iterator";
+    ++mCurrent;
+    if (mCurrent.isEnd()) receive();
+    return *this;
+}
+
+bool Socket::receive_iterator::operator==(const receive_iterator& other) const {
+    if (mIsEnd != other.mIsEnd) return false;
+    if (mIsEnd && other.mIsEnd) return true;
+    return mCurrent == other.mCurrent;
+}
+
+const Buffer<nlmsghdr>& Socket::receive_iterator::operator*() const {
+    CHECK(!mIsEnd) << "Trying to dereference end iterator";
+    return *mCurrent;
+}
+
+void Socket::receive_iterator::receive() {
+    CHECK(!mIsEnd) << "Trying to receive on end iterator";
+    CHECK(mCurrent.isEnd()) << "Trying to receive without draining previous read";
+
+    const auto buf = mSocket.receive();
+    if (buf.has_value()) {
+        mCurrent = buf->begin();
+    } else {
+        mIsEnd = true;
+    }
+}
+
+Socket::receive_iterator Socket::begin() {
+    return {*this, false};
+}
+
+Socket::receive_iterator Socket::end() {
+    return {*this, true};
+}
+
+}  // namespace android::nl