text: // Copyright 2018 Google LLC
  //
  // 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 "test/syscalls/linux/socket_non_stream.h"
  
  #include <stdio.h>
  #include <sys/un.h>
  
  #include "gtest/gtest.h"
  #include "gtest/gtest.h"
  #include "test/syscalls/linux/ip_socket_test_util.h"
  #include "test/syscalls/linux/socket_test_util.h"
  #include "test/syscalls/linux/unix_domain_socket_test_util.h"
  #include "test/util/test_util.h"
  
  namespace gvisor {
  namespace testing {
  
  TEST_P(NonStreamSocketPairTest, SendMsgTooLarge) {
    auto sockets = ASSERT_NO_ERRNO_AND_VALUE(NewSocketPair());
  
    int sndbuf;
    socklen_t length = sizeof(sndbuf);
    ASSERT_THAT(
        getsockopt(sockets->first_fd(), SOL_SOCKET, SO_SNDBUF, &sndbuf, &length),
        SyscallSucceeds());
  
    // Make the call too large to fit in the send buffer.
    const int buffer_size = 3 * sndbuf;
  
    EXPECT_THAT(SendLargeSendMsg(sockets, buffer_size, false /* reader */),
                SyscallFailsWithErrno(EMSGSIZE));
  }
  
  // Stream sockets allow data sent with a single (e.g. write, sendmsg) syscall
  // to be read in pieces with multiple (e.g. read, recvmsg) syscalls.
  //
  // SplitRecv checks that control messages can only be read on the first (e.g.
  // read, recvmsg) syscall, even if it doesn't provide space for the control
  // message.
  TEST_P(NonStreamSocketPairTest, SplitRecv) {
    auto sockets = ASSERT_NO_ERRNO_AND_VALUE(NewSocketPair());
    char sent_data[512];
    RandomizeBuffer(sent_data, sizeof(sent_data));
    ASSERT_THAT(
        RetryEINTR(send)(sockets->first_fd(), sent_data, sizeof(sent_data), 0),
        SyscallSucceedsWithValue(sizeof(sent_data)));
    char received_data[sizeof(sent_data) / 2];
    ASSERT_THAT(RetryEINTR(recv)(sockets->second_fd(), received_data,
                                 sizeof(received_data), 0),
                SyscallSucceedsWithValue(sizeof(received_data)));
    EXPECT_EQ(0, memcmp(sent_data, received_data, sizeof(received_data)));
    ASSERT_THAT(RetryEINTR(recv)(sockets->second_fd(), received_data,
                                 sizeof(received_data), MSG_DONTWAIT),
                SyscallFailsWithErrno(EWOULDBLOCK));
  }
  
  // Stream sockets allow data sent with multiple sends to be read in a single
  // recv. Datagram sockets do not.
  //
  // SingleRecv checks that only a single message is readable in a single recv.
  TEST_P(NonStreamSocketPairTest, SingleRecv) {
    auto sockets = ASSERT_NO_ERRNO_AND_VALUE(NewSocketPair());
    char sent_data1[20];
    RandomizeBuffer(sent_data1, sizeof(sent_data1));
    ASSERT_THAT(
        RetryEINTR(send)(sockets->first_fd(), sent_data1, sizeof(sent_data1), 0),
        SyscallSucceedsWithValue(sizeof(sent_data1)));
    char sent_data2[20];
    RandomizeBuffer(sent_data2, sizeof(sent_data2));
    ASSERT_THAT(
        RetryEINTR(send)(sockets->first_fd(), sent_data2, sizeof(sent_data2), 0),
        SyscallSucceedsWithValue(sizeof(sent_data2)));
    char received_data[sizeof(sent_data1) + sizeof(sent_data2)];
    ASSERT_THAT(RetryEINTR(recv)(sockets->second_fd(), received_data,
                                 sizeof(received_data), 0),
                SyscallSucceedsWithValue(sizeof(sent_data1)));
    EXPECT_EQ(0, memcmp(sent_data1, received_data, sizeof(sent_data1)));
  }
  
  // Stream sockets allow data sent with multiple sends to be peeked at in a
  // single recv. Datagram sockets (except for unix sockets) do not.
  //
  // SinglePeek checks that only a single message is peekable in a single recv.
  TEST_P(NonStreamSocketPairTest, SinglePeek) {
    auto sockets = ASSERT_NO_ERRNO_AND_VALUE(NewSocketPair());
    char sent_data1[20];
    RandomizeBuffer(sent_data1, sizeof(sent_data1));
    ASSERT_THAT(
        RetryEINTR(send)(sockets->first_fd(), sent_data1, sizeof(sent_data1), 0),
        SyscallSucceedsWithValue(sizeof(sent_data1)));
    char sent_data2[20];
    RandomizeBuffer(sent_data2, sizeof(sent_data2));
    ASSERT_THAT(
        RetryEINTR(send)(sockets->first_fd(), sent_data2, sizeof(sent_data2), 0),
        SyscallSucceedsWithValue(sizeof(sent_data2)));
    char received_data[sizeof(sent_data1) + sizeof(sent_data2)];
    for (int i = 0; i < 3; i++) {
      memset(received_data, 0, sizeof(received_data));
      ASSERT_THAT(RetryEINTR(recv)(sockets->second_fd(), received_data,
                                   sizeof(received_data), MSG_PEEK),
                  SyscallSucceedsWithValue(sizeof(sent_data1)));
      EXPECT_EQ(0, memcmp(sent_data1, received_data, sizeof(sent_data1)));
    }
    ASSERT_THAT(RetryEINTR(recv)(sockets->second_fd(), received_data,
                                 sizeof(sent_data1), 0),
                SyscallSucceedsWithValue(sizeof(sent_data1)));
    EXPECT_EQ(0, memcmp(sent_data1, received_data, sizeof(sent_data1)));
    ASSERT_THAT(RetryEINTR(recv)(sockets->second_fd(), received_data,
                                 sizeof(sent_data2), 0),
                SyscallSucceedsWithValue(sizeof(sent_data2)));
    EXPECT_EQ(0, memcmp(sent_data2, received_data, sizeof(sent_data2)));
  }
  
  TEST_P(NonStreamSocketPairTest, MsgTruncTruncation) {
    auto sockets = ASSERT_NO_ERRNO_AND_VALUE(NewSocketPair());
    char sent_data[512];
    RandomizeBuffer(sent_data, sizeof(sent_data));
    ASSERT_THAT(
        RetryEINTR(send)(sockets->first_fd(), sent_data, sizeof(sent_data), 0),
        SyscallSucceedsWithValue(sizeof(sent_data)));
    char received_data[sizeof(sent_data)] = {};
    ASSERT_THAT(RetryEINTR(recv)(sockets->second_fd(), received_data,
                                 sizeof(received_data) / 2, MSG_TRUNC),
                SyscallSucceedsWithValue(sizeof(sent_data)));
    EXPECT_EQ(0, memcmp(sent_data, received_data, sizeof(sent_data) / 2));
  
    // Check that we didn't get any extra data.
    EXPECT_NE(0, memcmp(sent_data + sizeof(sent_data) / 2,
                        received_data + sizeof(received_data) / 2,
                        sizeof(sent_data) / 2));
  }
  
  TEST_P(NonStreamSocketPairTest, MsgTruncSameSize) {
    auto sockets = ASSERT_NO_ERRNO_AND_VALUE(NewSocketPair());
    char sent_data[512];
    RandomizeBuffer(sent_data, sizeof(sent_data));
    ASSERT_THAT(
        RetryEINTR(send)(sockets->first_fd(), sent_data, sizeof(sent_data), 0),
        SyscallSucceedsWithValue(sizeof(sent_data)));
    char received_data[sizeof(sent_data)];
    ASSERT_THAT(RetryEINTR(recv)(sockets->second_fd(), received_data,
                                 sizeof(received_data), MSG_TRUNC),
                SyscallSucceedsWithValue(sizeof(received_data)));
    EXPECT_EQ(0, memcmp(sent_data, received_data, sizeof(sent_data)));
  }
  
  TEST_P(NonStreamSocketPairTest, MsgTruncNotFull) {
    auto sockets = ASSERT_NO_ERRNO_AND_VALUE(NewSocketPair());
    char sent_data[512];
    RandomizeBuffer(sent_data, sizeof(sent_data));
    ASSERT_THAT(
        RetryEINTR(send)(sockets->first_fd(), sent_data, sizeof(sent_data), 0),
        SyscallSucceedsWithValue(sizeof(sent_data)));
    char received_data[2 * sizeof(sent_data)];
    ASSERT_THAT(RetryEINTR(recv)(sockets->second_fd(), received_data,
                                 sizeof(received_data), MSG_TRUNC),
                SyscallSucceedsWithValue(sizeof(sent_data)));
    EXPECT_EQ(0, memcmp(sent_data, received_data, sizeof(sent_data)));
  }
  
  }  // namespace testing
  }  // namespace gvisor
  