Add support for sendmmsg GSO option

Summary: Add support for sendmmsg GSO option

Reviewed By: yfeldblum

Differential Revision: D19521628

fbshipit-source-id: 5611074a5cfb626ce42ffe99d1de78b8e57238c2

folly/io/async/AsyncUDPSocket.cpp

@@ -358,18 +358,47 @@ int AsyncUDPSocket::writem(
     const folly::SocketAddress& address,
     const std::unique_ptr<folly::IOBuf>* bufs,
     size_t count) {
+  return writemGSO(address, bufs, count, nullptr);
+}
+
+int AsyncUDPSocket::writemGSO(
+    const folly::SocketAddress& address,
+    const std::unique_ptr<folly::IOBuf>* bufs,
+    size_t count,
+    const int* gso) {
   int ret;
   constexpr size_t kSmallSizeMax = 8;
+  char* gsoControl = nullptr;
+#ifndef FOLLY_HAVE_MSG_ERRQUEUE
+  CHECK(!gso) << "GSO not supported";
+#endif
   if (count <= kSmallSizeMax) {
     // suppress "warning: variable length array 'vec' is used [-Wvla]"
     FOLLY_PUSH_WARNING
     FOLLY_GNU_DISABLE_WARNING("-Wvla")
     mmsghdr vec[BOOST_PP_IF(FOLLY_HAVE_VLA_01, count, kSmallSizeMax)];
+#ifdef FOLLY_HAVE_MSG_ERRQUEUE
+    // we will allocate this on the stack anyway even if we do not use it
+    char control
+        [(BOOST_PP_IF(FOLLY_HAVE_VLA_01, count, kSmallSizeMax)) *
+         (CMSG_SPACE(sizeof(uint16_t)))];
+
+    if (gso) {
+      gsoControl = control;
+    }
+#endif
     FOLLY_POP_WARNING
-    ret = writeImpl(address, bufs, count, vec);
+    ret = writeImpl(address, bufs, count, vec, gso, gsoControl);
   } else {
     std::unique_ptr<mmsghdr[]> vec(new mmsghdr[count]);
-    ret = writeImpl(address, bufs, count, vec.get());
+#ifdef FOLLY_HAVE_MSG_ERRQUEUE
+    std::unique_ptr<char[]> control(
+        gso ? (new char[count * (CMSG_SPACE(sizeof(uint16_t)))]) : nullptr);
+    if (gso) {
+      gsoControl = control.get();
+    }
+#endif
+    ret = writeImpl(address, bufs, count, vec.get(), gso, gsoControl);
   }
 
   return ret;
@@ -382,21 +411,41 @@ void AsyncUDPSocket::fillMsgVec(
     size_t count,
     struct mmsghdr* msgvec,
     struct iovec* iov,
-    size_t iov_count) {
+    size_t iov_count,
+    const int* gso,
+    char* gsoControl) {
   size_t remaining = iov_count;
 
   size_t iov_pos = 0;
   for (size_t i = 0; i < count; i++) {
     // we can use remaining here to avoid calling countChainElements() again
-    size_t iovec_len = bufs[i]->fillIov(&iov[iov_pos], remaining).numIovecs;
+    auto ret = bufs[i]->fillIov(&iov[iov_pos], remaining);
+    size_t iovec_len = ret.numIovecs;
     remaining -= iovec_len;
     auto& msg = msgvec[i].msg_hdr;
     msg.msg_name = reinterpret_cast<void*>(addr);
     msg.msg_namelen = addr_len;
     msg.msg_iov = &iov[iov_pos];
     msg.msg_iovlen = iovec_len;
+#ifdef FOLLY_HAVE_MSG_ERRQUEUE
+    if (gso && gso[i] > 0) {
+      msg.msg_control = &gsoControl[i * CMSG_SPACE(sizeof(uint16_t))];
+      msg.msg_controllen = CMSG_SPACE(sizeof(uint16_t));
+
+      struct cmsghdr* cm = CMSG_FIRSTHDR(&msg);
+      cm->cmsg_level = SOL_UDP;
+      cm->cmsg_type = UDP_SEGMENT;
+      cm->cmsg_len = CMSG_LEN(sizeof(uint16_t));
+      auto gso_len = static_cast<uint16_t>(gso[i]);
+      memcpy(CMSG_DATA(cm), &gso_len, sizeof(gso_len));
+    } else {
       msg.msg_control = nullptr;
       msg.msg_controllen = 0;
+    }
+#else
+    msg.msg_control = nullptr;
+    msg.msg_controllen = 0;
+#endif
     msg.msg_flags = 0;
 
     msgvec[i].msg_len = 0;
@@ -409,7 +458,9 @@ int AsyncUDPSocket::writeImpl(
     const folly::SocketAddress& address,
     const std::unique_ptr<folly::IOBuf>* bufs,
     size_t count,
-    struct mmsghdr* msgvec) {
+    struct mmsghdr* msgvec,
+    const int* gso,
+    char* gsoControl) {
   sockaddr_storage addrStorage;
   address.getAddress(&addrStorage);
 
@@ -433,7 +484,9 @@ int AsyncUDPSocket::writeImpl(
         count,
         msgvec,
         iov,
-        iov_count);
+        iov_count,
+        gso,
+        gsoControl);
     ret = sendmmsg(fd_, msgvec, count, 0);
   } else {
     std::unique_ptr<iovec[]> iov(new iovec[iov_count]);
@@ -444,7 +497,9 @@ int AsyncUDPSocket::writeImpl(
         count,
         msgvec,
         iov.get(),
-        iov_count);
+        iov_count,
+        gso,
+        gsoControl);
     ret = sendmmsg(fd_, msgvec, count, 0);
   }
 

folly/io/async/AsyncUDPSocket.h

@@ -181,6 +181,21 @@ class AsyncUDPSocket : public EventHandler {
       const std::unique_ptr<folly::IOBuf>& buf,
       int gso);
 
+  /**
+   * Send the data in buffers to destination. Returns the return code from
+   * ::sendmmsg.
+   * bufs is an array of std::unique_ptr<folly::IOBuf>
+   * of size num
+   * gso is an array with the generic segmentation offload values or nullptr
+   *  Before calling writeGSO with a positive value
+   *  verify GSO is supported on this platform by calling getGSO
+   */
+  virtual int writemGSO(
+      const folly::SocketAddress& address,
+      const std::unique_ptr<folly::IOBuf>* bufs,
+      size_t count,
+      const int* gso);
+
   /**
    * Send data in iovec to destination. Returns the return code from sendmsg.
    */
@@ -354,13 +369,17 @@ class AsyncUDPSocket : public EventHandler {
       size_t count,
       struct mmsghdr* msgvec,
       struct iovec* iov,
-      size_t iov_count);
+      size_t iov_count,
+      const int* gso,
+      char* gsoControl);
 
   virtual int writeImpl(
       const folly::SocketAddress& address,
       const std::unique_ptr<folly::IOBuf>* bufs,
       size_t count,
-      struct mmsghdr* msgvec);
+      struct mmsghdr* msgvec,
+      const int* gso,
+      char* gsoControl);
 
   size_t handleErrMessages() noexcept;
 

folly/io/async/test/AsyncUDPSocketGSOTest.cpp

@@ -41,21 +41,48 @@ struct TestData {
       bool useSocketGSO,
       int* in,
       size_t inLen,
-      int* expected,
+      const int* expected,
       size_t expectedLen)
       : gso_(gso), useSocketGSO_(useSocketGSO) {
-    in_.assign(in, in + inLen);
+    std::vector<int> inVec;
+    inVec.assign(in, in + inLen);
+    in_.emplace_back(std::move(inVec));
+    expected_.assign(expected, expected + expectedLen);
+
+    expectedSize_ = std::accumulate(expected_.begin(), expected_.end(), 0);
+  }
+
+  TestData(
+      const std::vector<int>& gsoVec,
+      bool useSocketGSO,
+      const std::vector<std::vector<int>>& in,
+      const int* expected,
+      size_t expectedLen)
+      : gsoVec_(gsoVec), useSocketGSO_(useSocketGSO), in_(in) {
     expected_.assign(expected, expected + expectedLen);
 
     expectedSize_ = std::accumulate(expected_.begin(), expected_.end(), 0);
   }
 
   bool checkIn() const {
-    return (expectedSize_ == std::accumulate(in_.begin(), in_.end(), 0));
+    int expected = 0;
+    for (const auto& in : in_) {
+      expected += std::accumulate(in.begin(), in.end(), 0);
+    }
+    return (expectedSize_ == expected);
   }
 
   bool checkOut() const {
-    return (expectedSize_ == std::accumulate(out_.begin(), out_.end(), 0));
+    auto size = std::accumulate(out_.begin(), out_.end(), 0);
+    auto ret = (expectedSize_ == size);
+    if (!ret) {
+      LOG(ERROR) << "expected = " << expectedSize_ << " actual = " << size;
+      for (const auto& out : out_) {
+        LOG(ERROR) << out;
+      }
+    }
+
+    return ret;
   }
 
   bool appendOut(int num) {
@@ -65,26 +92,61 @@ struct TestData {
     return (outSize_ >= expectedSize_);
   }
 
+  bool isMulti() const {
+    return (in_.size() > 1);
+  }
+
+  const int* getGSOVec() const {
+    return (!gsoVec_.empty()) ? gsoVec_.data() : nullptr;
+  }
+
   std::unique_ptr<folly::IOBuf> getInBuf() {
     if (!in_.size()) {
       return nullptr;
     }
 
-    std::string str(in_[0], 'A');
+    auto& in = in_[0];
+
+    std::string str(in[0], 'A');
     std::unique_ptr<folly::IOBuf> ret =
         folly::IOBuf::copyBuffer(str.data(), str.size());
 
-    for (size_t i = 1; i < in_.size(); i++) {
-      str = std::string(in_[i], 'A');
+    for (size_t i = 1; i < in.size(); i++) {
+      str = std::string(in[i], 'A');
       ret->prependChain(folly::IOBuf::copyBuffer(str.data(), str.size()));
     }
 
     return ret;
   }
 
+  std::vector<std::unique_ptr<folly::IOBuf>> getInBufs() {
+    if (!in_.size()) {
+      return std::vector<std::unique_ptr<folly::IOBuf>>();
+    }
+
+    std::vector<std::unique_ptr<folly::IOBuf>> ret;
+    ret.reserve(in_.size());
+
+    for (const auto& in : in_) {
+      std::string str(in[0], 'A');
+      std::unique_ptr<folly::IOBuf> buf =
+          folly::IOBuf::copyBuffer(str.data(), str.size());
+
+      for (size_t i = 1; i < in.size(); i++) {
+        str = std::string(in[i], 'A');
+        buf->prependChain(folly::IOBuf::copyBuffer(str.data(), str.size()));
+      }
+
+      ret.emplace_back(std::move(buf));
+    }
+
+    return ret;
+  }
+
   int gso_{0};
+  std::vector<int> gsoVec_;
   bool useSocketGSO_{false};
-  std::vector<int> in_;
+  std::vector<std::vector<int>> in_;
   std::vector<int> expected_; // expected
   int expectedSize_;
   std::vector<int> out_;
@@ -244,14 +306,24 @@ class UDPClient : private AsyncUDPSocket::ReadCallback, private AsyncTimeout {
 
   void sendPing() {
     scheduleTimeout(5);
+    if (testData_.isMulti()) {
+      writePing(testData_.getInBufs(), testData_.getGSOVec());
+    } else {
       writePing(
           testData_.getInBuf(), testData_.useSocketGSO_ ? -1 : testData_.gso_);
     }
+  }
 
   virtual void writePing(std::unique_ptr<folly::IOBuf> buf, int gso) {
     socket_->writeGSO(server_, std::move(buf), gso);
   }
 
+  virtual void writePing(
+      const std::vector<std::unique_ptr<folly::IOBuf>>& vec,
+      const int* gso) {
+    socket_->writemGSO(server_, vec.data(), vec.size(), gso);
+  }
+
   void getReadBuffer(void** buf, size_t* len) noexcept override {
     *buf = buf_;
     *len = sizeof(buf_);
@@ -404,6 +476,67 @@ TEST_F(AsyncSocketGSOIntegrationTest, PingPongRequestGSO) {
   ASSERT_TRUE(testData.checkOut());
 }
 
+TEST_F(AsyncSocketGSOIntegrationTest, MultiPingPongGlobalGSO) {
+  std::vector<int> gsoVec = {1000, 800, 1100, 1200};
+  std::vector<std::vector<int>> inVec;
+  inVec.reserve(gsoVec.size());
+  std::vector<int> in = {100, 1200, 3000, 200, 100, 300};
+  int total = std::accumulate(in.begin(), in.end(), 0);
+  std::vector<int> expected;
+  for (size_t i = 0; i < gsoVec.size(); i++) {
+    inVec.push_back(in);
+
+    auto remaining = total;
+    while (remaining) {
+      if (remaining > gsoVec[i]) {
+        expected.push_back(gsoVec[i]);
+        remaining -= gsoVec[i];
+      } else {
+        expected.push_back(remaining);
+        remaining = 0;
+      }
+    }
+  }
+
+  TestData testData(
+      gsoVec, true /*useSocketGSO*/, inVec, expected.data(), expected.size());
+  ASSERT_TRUE(testData.checkIn());
+  startServer();
+  auto pingClient = performPingPongTest(testData, folly::none);
+  ASSERT_TRUE(testData.checkOut());
+}
+
+TEST_F(AsyncSocketGSOIntegrationTest, MultiPingPongRequestGSO) {
+  std::vector<int> gsoVec = {421, 300, 528, 680};
+  std::vector<std::vector<int>> inVec;
+  inVec.reserve(gsoVec.size());
+
+  std::vector<int> in = {100, 1200, 3000, 200, 100, 300};
+  int total = std::accumulate(in.begin(), in.end(), 0);
+  std::vector<int> expected;
+  for (size_t i = 0; i < gsoVec.size(); i++) {
+    inVec.push_back(in);
+
+    auto remaining = total;
+    while (remaining) {
+      if (remaining > gsoVec[i]) {
+        expected.push_back(gsoVec[i]);
+        remaining -= gsoVec[i];
+      } else {
+        expected.push_back(remaining);
+        remaining = 0;
+      }
+    }
+  }
+
+  TestData testData(
+      gsoVec, false /*useSocketGSO*/, inVec, expected.data(), expected.size());
+  ASSERT_TRUE(testData.checkIn());
+  startServer();
+  auto pingClient = performPingPongTest(testData, folly::none);
+  ASSERT_TRUE(testData.checkOut());
+}
+
 // buffer sizes
 constexpr auto kGSO1 = 100;
 constexpr auto kGSO2 = 200;