text: // Copyright 2018 The gVisor Authors.
  //
  // 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 <sys/socket.h>
  #include <sys/stat.h>
  #include <sys/statfs.h>
  #include <sys/types.h>
  #include <sys/wait.h>
  #include <unistd.h>
  
  #include "gtest/gtest.h"
  #include "test/util/file_descriptor.h"
  #include "test/util/socket_util.h"
  #include "test/util/temp_umask.h"
  #include "test/util/test_util.h"
  
  namespace gvisor {
  namespace testing {
  
  // From linux/magic.h, but we can't depend on linux headers here.
  #define SOCKFS_MAGIC 0x534F434B
  
  TEST(SocketTest, UnixSocketPairProtocol) {
    int socks[2];
    ASSERT_THAT(socketpair(AF_UNIX, SOCK_STREAM, PF_UNIX, socks),
                SyscallSucceeds());
    close(socks[0]);
    close(socks[1]);
  }
  
  TEST(SocketTest, ProtocolUnix) {
    struct {
      int domain, type, protocol;
    } tests[] = {
        {AF_UNIX, SOCK_STREAM, PF_UNIX},
        {AF_UNIX, SOCK_SEQPACKET, PF_UNIX},
        {AF_UNIX, SOCK_DGRAM, PF_UNIX},
    };
    for (size_t i = 0; i < ABSL_ARRAYSIZE(tests); i++) {
      ASSERT_NO_ERRNO_AND_VALUE(
          Socket(tests[i].domain, tests[i].type, tests[i].protocol));
    }
  }
  
  TEST(SocketTest, ProtocolInet) {
    struct {
      int domain, type, protocol;
    } tests[] = {
        {AF_INET, SOCK_DGRAM, IPPROTO_UDP},
        {AF_INET, SOCK_STREAM, IPPROTO_TCP},
    };
    for (size_t i = 0; i < ABSL_ARRAYSIZE(tests); i++) {
      ASSERT_NO_ERRNO_AND_VALUE(
          Socket(tests[i].domain, tests[i].type, tests[i].protocol));
    }
  }
  
  TEST(SocketTest, UnixSocketStat) {
    SKIP_IF(IsRunningWithVFS1());
  
    FileDescriptor bound =
        ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_UNIX, SOCK_STREAM, PF_UNIX));
  
    // The permissions of the file created with bind(2) should be defined by the
    // permissions of the bound socket and the umask.
    mode_t sock_perm = 0765, mask = 0123;
    ASSERT_THAT(fchmod(bound.get(), sock_perm), SyscallSucceeds());
    TempUmask m(mask);
  
    struct sockaddr_un addr =
        ASSERT_NO_ERRNO_AND_VALUE(UniqueUnixAddr(/*abstract=*/false, AF_UNIX));
    ASSERT_THAT(bind(bound.get(), reinterpret_cast<struct sockaddr*>(&addr),
                     sizeof(addr)),
                SyscallSucceeds());
  
    struct stat statbuf = {};
    ASSERT_THAT(stat(addr.sun_path, &statbuf), SyscallSucceeds());
  
    // Mode should be S_IFSOCK.
    EXPECT_EQ(statbuf.st_mode, S_IFSOCK | (sock_perm & ~mask));
  
    // Timestamps should be equal and non-zero.
    if (!IsRunningWithVFS1()) {
      EXPECT_NE(statbuf.st_atime, 0);
      EXPECT_EQ(statbuf.st_atime, statbuf.st_mtime);
      EXPECT_EQ(statbuf.st_atime, statbuf.st_ctime);
    }
  }
  
  TEST(SocketTest, UnixSocketStatFS) {
    SKIP_IF(IsRunningWithVFS1());
  
    FileDescriptor bound =
        ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_UNIX, SOCK_STREAM, PF_UNIX));
  
    struct statfs st;
    EXPECT_THAT(fstatfs(bound.get(), &st), SyscallSucceeds());
    EXPECT_EQ(st.f_type, SOCKFS_MAGIC);
    EXPECT_EQ(st.f_bsize, getpagesize());
    EXPECT_EQ(st.f_namelen, NAME_MAX);
  }
  
  TEST(SocketTest, UnixSCMRightsOnlyPassedOnce) {
    const DisableSave ds;
  
    int sockets[2];
    ASSERT_THAT(socketpair(AF_UNIX, SOCK_STREAM, 0, sockets), SyscallSucceeds());
    // Send more than what will fit inside the send/receive buffers, so that it is
    // split into multiple messages.
    constexpr int kBufSize = 0x100000;
    // Heap allocation is async-signal-unsafe and thus cannot occur between fork()
    // and execve().
    std::vector<char> buf(kBufSize);
  
    pid_t pid = fork();
    if (pid == 0) {
      TEST_PCHECK(close(sockets[0]) == 0);
  
      // Construct a message with some control message.
      struct msghdr msg = {};
      char control[CMSG_SPACE(sizeof(int))] = {};
      struct iovec iov = {};
      msg.msg_control = control;
      msg.msg_controllen = sizeof(control);
  
      struct cmsghdr* cmsg = CMSG_FIRSTHDR(&msg);
      cmsg->cmsg_len = CMSG_LEN(sizeof(int));
      cmsg->cmsg_level = SOL_SOCKET;
      cmsg->cmsg_type = SCM_RIGHTS;
      ((int*)CMSG_DATA(cmsg))[0] = sockets[1];
  
      iov.iov_base = buf.data();
      iov.iov_len = kBufSize;
      msg.msg_iov = &iov;
      msg.msg_iovlen = 1;
  
      int n = sendmsg(sockets[1], &msg, 0);
      TEST_PCHECK(n == kBufSize);
      TEST_PCHECK(shutdown(sockets[1], SHUT_RDWR) == 0);
      TEST_PCHECK(close(sockets[1]) == 0);
      _exit(0);
    }
  
    close(sockets[1]);
  
    struct msghdr msg = {};
    char control[CMSG_SPACE(sizeof(int))] = {};
    struct iovec iov = {};
    msg.msg_control = &control;
    msg.msg_controllen = sizeof(control);
  
    iov.iov_base = buf.data();
    iov.iov_len = kBufSize;
    msg.msg_iov = &iov;
    msg.msg_iovlen = 1;
  
    // The control message should only be present in the first message received.
    int n;
    ASSERT_THAT(n = recvmsg(sockets[0], &msg, 0), SyscallSucceeds());
    ASSERT_GT(n, 0);
    ASSERT_EQ(msg.msg_controllen, CMSG_SPACE(sizeof(int)));
  
    while (n > 0) {
      ASSERT_THAT(n = recvmsg(sockets[0], &msg, 0), SyscallSucceeds());
      ASSERT_EQ(msg.msg_controllen, 0);
    }
  
    close(sockets[0]);
  
    int status;
    ASSERT_THAT(waitpid(pid, &status, 0), SyscallSucceedsWithValue(pid));
    ASSERT_TRUE(WIFEXITED(status) && WEXITSTATUS(status) == 0);
  }
  
  using SocketOpenTest = ::testing::TestWithParam<int>;
  
  // UDS cannot be opened.
  TEST_P(SocketOpenTest, Unix) {
    // FIXME(b/142001530): Open incorrectly succeeds on gVisor.
    SKIP_IF(IsRunningWithVFS1());
  
    FileDescriptor bound =
        ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_UNIX, SOCK_STREAM, PF_UNIX));
  
    struct sockaddr_un addr =
        ASSERT_NO_ERRNO_AND_VALUE(UniqueUnixAddr(/*abstract=*/false, AF_UNIX));
  
    ASSERT_THAT(bind(bound.get(), reinterpret_cast<struct sockaddr*>(&addr),
                     sizeof(addr)),
                SyscallSucceeds());
  
    EXPECT_THAT(open(addr.sun_path, GetParam()), SyscallFailsWithErrno(ENXIO));
  }
  
  INSTANTIATE_TEST_SUITE_P(OpenModes, SocketOpenTest,
                           ::testing::Values(O_RDONLY, O_RDWR));
  
  }  // namespace testing
  }  // namespace gvisor
  