text: /*
   * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include <AK/Assertions.h>
  #include <AK/LogStream.h>
  #include <AK/Types.h>
  #include <fcntl.h>
  #include <stdio.h>
  #include <string.h>
  #include <sys/mman.h>
  #include <sys/stat.h>
  #include <sys/uio.h>
  #include <unistd.h>
  
  #define EXPECT_ERROR_2(err, syscall, arg1, arg2)                                                                                                                          \
      do {                                                                                                                                                                  \
          rc = syscall(arg1, arg2);                                                                                                                                         \
          if (rc >= 0 || errno != err) {                                                                                                                                    \
              fprintf(stderr, __FILE__ ":%d: Expected " #err ": " #syscall "(%p, %p), got rc=%d, errno=%d\n", __LINE__, (const void*)(arg1), (const void*)arg2, rc, errno); \
          }                                                                                                                                                                 \
      } while (0)
  
  #define EXPECT_ERROR_3(err, syscall, arg1, arg2, arg3)                                                                                                                                               \
      do {                                                                                                                                                                                             \
          rc = syscall(arg1, arg2, arg3);                                                                                                                                                              \
          if (rc >= 0 || errno != err) {                                                                                                                                                               \
              fprintf(stderr, __FILE__ ":%d: Expected " #err ": " #syscall "(%p, %p, %p), got rc=%d, errno=%d\n", __LINE__, (const void*)(arg1), (const void*)(arg2), (const void*)(arg3), rc, errno); \
          }                                                                                                                                                                                            \
      } while (0)
  
  void test_read_from_directory()
  {
      char buffer[BUFSIZ];
      int fd = open("/", O_DIRECTORY | O_RDONLY);
      ASSERT(fd >= 0);
      int rc;
      EXPECT_ERROR_3(EISDIR, read, fd, buffer, sizeof(buffer));
      rc = close(fd);
      ASSERT(rc == 0);
  }
  
  void test_write_to_directory()
  {
      char str[] = "oh frick";
      int fd = open("/", O_DIRECTORY | O_RDONLY);
      if (fd < 0)
          perror("open");
      ASSERT(fd >= 0);
      int rc;
      EXPECT_ERROR_3(EBADF, write, fd, str, sizeof(str));
      rc = close(fd);
      ASSERT(rc == 0);
  }
  
  void test_read_from_writeonly()
  {
      char buffer[BUFSIZ];
      int fd = open("/tmp/xxxx123", O_CREAT | O_WRONLY);
      ASSERT(fd >= 0);
      int rc;
      EXPECT_ERROR_3(EBADF, read, fd, buffer, sizeof(buffer));
      rc = close(fd);
      ASSERT(rc == 0);
  }
  
  void test_write_to_readonly()
  {
      char str[] = "hello";
      int fd = open("/tmp/abcd123", O_CREAT | O_RDONLY);
      ASSERT(fd >= 0);
      int rc;
      EXPECT_ERROR_3(EBADF, write, fd, str, sizeof(str));
      rc = close(fd);
      ASSERT(rc == 0);
  }
  
  void test_read_past_eof()
  {
      char buffer[BUFSIZ];
      int fd = open("/home/anon/myfile.txt", O_RDONLY);
      if (fd < 0)
          perror("open");
      ASSERT(fd >= 0);
      int rc;
      rc = lseek(fd, 9999, SEEK_SET);
      if (rc < 0)
          perror("lseek");
      rc = read(fd, buffer, sizeof(buffer));
      if (rc < 0)
          perror("read");
      if (rc > 0)
          fprintf(stderr, "read %d bytes past EOF\n", rc);
      rc = close(fd);
      ASSERT(rc == 0);
  }
  
  void test_ftruncate_readonly()
  {
      int fd = open("/tmp/trunctest", O_RDONLY | O_CREAT, 0666);
      ASSERT(fd >= 0);
      int rc;
      EXPECT_ERROR_2(EBADF, ftruncate, fd, 0);
      close(fd);
  }
  
  void test_ftruncate_negative()
  {
      int fd = open("/tmp/trunctest", O_RDWR | O_CREAT, 0666);
      ASSERT(fd >= 0);
      int rc;
      EXPECT_ERROR_2(EINVAL, ftruncate, fd, -1);
      close(fd);
  }
  
  void test_mmap_directory()
  {
      int fd = open("/tmp", O_RDONLY | O_DIRECTORY);
      ASSERT(fd >= 0);
      auto* ptr = mmap(nullptr, 4096, PROT_READ, MAP_FILE | MAP_SHARED, fd, 0);
      if (ptr != MAP_FAILED) {
          fprintf(stderr, "Boo! mmap() of a directory succeeded!\n");
          return;
      }
      if (errno != ENODEV) {
          fprintf(stderr, "Boo! mmap() of a directory gave errno=%d instead of ENODEV!\n", errno);
          return;
      }
      close(fd);
  }
  
  void test_tmpfs_read_past_end()
  {
      int fd = open("/tmp/x", O_RDWR | O_CREAT | O_TRUNC, 0600);
      ASSERT(fd >= 0);
  
      int rc = ftruncate(fd, 1);
      ASSERT(rc == 0);
  
      rc = lseek(fd, 4096, SEEK_SET);
      ASSERT(rc == 4096);
  
      char buffer[16];
      int nread = read(fd, buffer, sizeof(buffer));
      if (nread != 0) {
          fprintf(stderr, "Expected 0-length read past end of file in /tmp\n");
      }
      close(fd);
  }
  
  void test_procfs_read_past_end()
  {
      int fd = open("/proc/uptime", O_RDONLY);
      ASSERT(fd >= 0);
  
      int rc = lseek(fd, 4096, SEEK_SET);
      ASSERT(rc == 4096);
  
      char buffer[16];
      int nread = read(fd, buffer, sizeof(buffer));
      if (nread != 0) {
          fprintf(stderr, "Expected 0-length read past end of file in /proc\n");
      }
      close(fd);
  }
  
  void test_open_create_device()
  {
      int fd = open("/tmp/fakedevice", (O_RDWR | O_CREAT), (S_IFCHR | 0600));
      ASSERT(fd >= 0);
  
      struct stat st;
      if (fstat(fd, &st) < 0) {
          perror("stat");
          ASSERT_NOT_REACHED();
      }
  
      if (st.st_mode != 0100600) {
          fprintf(stderr, "Expected mode 0100600 after attempt to create a device node with open(O_CREAT), mode=%o\n", st.st_mode);
      }
      unlink("/tmp/fakedevice");
      close(fd);
  }
  
  void test_unlink_symlink()
  {
      int rc = symlink("/proc/2/foo", "/tmp/linky");
      if (rc < 0) {
          perror("symlink");
          ASSERT_NOT_REACHED();
      }
  
      char buffer[PATH_MAX];
      rc = readlink("/tmp/linky", buffer, sizeof(buffer));
      ASSERT(rc == strlen("/proc/2/foo"));
  
      rc = unlink("/tmp/linky");
      if (rc < 0) {
          perror("unlink");
          fprintf(stderr, "Expected unlink() of a symlink into an unreadable directory to succeed!\n");
      }
  }
  
  void test_eoverflow()
  {
      int fd = open("/tmp/x", O_RDWR);
      ASSERT(fd >= 0);
  
      int rc = lseek(fd, INT32_MAX, SEEK_SET);
      ASSERT(rc == INT32_MAX);
  
      char buffer[16];
      rc = read(fd, buffer, sizeof(buffer));
      if (rc >= 0 || errno != EOVERFLOW) {
          fprintf(stderr, "Expected EOVERFLOW when trying to read past INT32_MAX\n");
      }
      rc = write(fd, buffer, sizeof(buffer));
      if (rc >= 0 || errno != EOVERFLOW) {
          fprintf(stderr, "Expected EOVERFLOW when trying to write past INT32_MAX\n");
      }
      close(fd);
  }
  
  void test_rmdir_while_inside_dir()
  {
      int rc = mkdir("/home/anon/testdir", 0700);
      ASSERT(rc == 0);
  
      rc = chdir("/home/anon/testdir");
      ASSERT(rc == 0);
  
      rc = rmdir("/home/anon/testdir");
      ASSERT(rc == 0);
  
      int fd = open("x", O_CREAT | O_RDWR, 0600);
      if (fd >= 0 || errno != ENOENT) {
          fprintf(stderr, "Expected ENOENT when trying to create a file inside a deleted directory. Got %d with errno=%d\n", fd, errno);
      }
  
      rc = chdir("/home/anon");
      ASSERT(rc == 0);
  }
  
  void test_writev()
  {
      int pipefds[2];
      pipe(pipefds);
  
      iovec iov[2];
      iov[0].iov_base = const_cast<void*>((const void*)"Hello");
      iov[0].iov_len = 5;
      iov[1].iov_base = const_cast<void*>((const void*)"Friends");
      iov[1].iov_len = 7;
      int nwritten = writev(pipefds[1], iov, 2);
      if (nwritten < 0) {
          perror("writev");
          ASSERT_NOT_REACHED();
      }
      if (nwritten != 12) {
          fprintf(stderr, "Didn't write 12 bytes to pipe with writev\n");
          ASSERT_NOT_REACHED();
      }
  
      char buffer[32];
      int nread = read(pipefds[0], buffer, sizeof(buffer));
      if (nread != 12 || memcmp(buffer, "HelloFriends", 12)) {
          fprintf(stderr, "Didn't read the expected data from pipe after writev\n");
          ASSERT_NOT_REACHED();
      }
  
      close(pipefds[0]);
      close(pipefds[1]);
  }
  
  void test_rmdir_root()
  {
      int rc = rmdir("/");
      if (rc != -1 || errno != EBUSY) {
          warn() << "rmdir(/) didn't fail with EBUSY";
          ASSERT_NOT_REACHED();
      }
  }
  
  int main(int, char**)
  {
      int rc;
      EXPECT_ERROR_2(ENOTDIR, open, "/dev/zero", (O_DIRECTORY | O_RDONLY));
      EXPECT_ERROR_2(EINVAL, open, "/dev/zero", (O_DIRECTORY | O_CREAT | O_RDWR));
      EXPECT_ERROR_2(EEXIST, open, "/dev/zero", (O_CREAT | O_EXCL | O_RDWR));
      EXPECT_ERROR_2(EINVAL, open, "/tmp/abcdef", (O_DIRECTORY | O_CREAT | O_RDWR));
      EXPECT_ERROR_2(EACCES, open, "/proc/all", (O_RDWR));
      EXPECT_ERROR_2(ENOENT, open, "/boof/baaf/nonexistent", (O_CREAT | O_RDWR));
      EXPECT_ERROR_2(EISDIR, open, "/tmp", (O_DIRECTORY | O_RDWR));
  
      test_read_from_directory();
      test_write_to_directory();
      test_read_from_writeonly();
      test_write_to_readonly();
      test_read_past_eof();
      test_ftruncate_readonly();
      test_ftruncate_negative();
      test_mmap_directory();
      test_tmpfs_read_past_end();
      test_procfs_read_past_end();
      test_open_create_device();
      test_unlink_symlink();
      test_eoverflow();
      test_rmdir_while_inside_dir();
      test_writev();
      test_rmdir_root();
  
      EXPECT_ERROR_2(EPERM, link, "/", "/home/anon/lolroot");
  
      return 0;
  }
  