/* Tests for copy_file_range.

   Copyright (C) 2017-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <array_length.h>

#include <errno.h>

#include <fcntl.h>

#include <inttypes.h>

#include <stdbool.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <support/check.h>

#include <support/support.h>

#include <support/temp_file.h>

#include <support/test-driver.h>

#include <support/xunistd.h>

/* Boolean flags which indicate whether to use pointers with explicit

   output flags.  */

static int do_inoff;

static int do_outoff;

/* Name and descriptors of the input files.  Files are truncated and

   reopened (with O_RDWR) between tests.  */

static char *infile;

static int infd;

static char *outfile;

static int outfd;

/* Input and output offsets.  Set according to do_inoff and do_outoff

   before the test.  The offsets themselves are always set to

   zero.  */

static off64_t inoff;

static off64_t *pinoff;

static off64_t outoff;

static off64_t *poutoff;

/* These are a collection of copy sizes used in tests.    */

enum { maximum_size = 99999 };

static const int typical_sizes[] =

  { 0, 1, 2, 3, 1024, 2048, 4096, 8191, 8192, 8193, maximum_size };

/* The random contents of this array can be used as a pattern to check

   for correct write operations.  */

static unsigned char random_data[maximum_size];

/* The size chosen by the test harness.  */

static int current_size;

/* Perform a copy of a file.  */

static void

simple_file_copy (void)

{

  xwrite (infd, random_data, current_size);

  int length;

  int in_skipped; /* Expected skipped bytes in input.  */

  if (do_inoff)

    {

      xlseek (infd, 1, SEEK_SET);

      inoff = 2;

      length = current_size - 3;

      in_skipped = 2;

    }

  else

    {

      xlseek (infd, 3, SEEK_SET);

      length = current_size - 5;

      in_skipped = 3;

    }

  int out_skipped; /* Expected skipped bytes before the written data.  */

  if (do_outoff)

    {

      xlseek (outfd, 4, SEEK_SET);

      outoff = 5;

      out_skipped = 5;

    }

  else

    {

      xlseek (outfd, 6, SEEK_SET);

      length = current_size - 6;

      out_skipped = 6;

    }

  if (length < 0)

    length = 0;

  TEST_COMPARE (copy_file_range (infd, pinoff, outfd, poutoff,

                                 length, 0), length);

  if (do_inoff)

    {

      TEST_COMPARE (inoff, 2 + length);

      TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 1);

    }

  else

    TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 3 + length);

  if (do_outoff)

    {

      TEST_COMPARE (outoff, 5 + length);

      TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), 4);

    }

  else

    TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), 6 + length);

  struct stat64 st;

  xfstat (outfd, &st);

  if (length > 0)

    TEST_COMPARE (st.st_size, out_skipped + length);

  else

    {

      /* If we did not write anything, we also did not add any

         padding.  */

      TEST_COMPARE (st.st_size, 0);

      return;

    }

  xlseek (outfd, 0, SEEK_SET);

  char *bytes = xmalloc (st.st_size);

  TEST_COMPARE (read (outfd, bytes, st.st_size), st.st_size);

  for (int i = 0; i < out_skipped; ++i)

    TEST_COMPARE (bytes[i], 0);

  TEST_VERIFY (memcmp (bytes + out_skipped, random_data + in_skipped,

                       length) == 0);

  free (bytes);

}

/* Test that a short input file results in a shortened copy.  */

static void

short_copy (void)

{

  if (current_size == 0)

    /* Nothing to shorten.  */

    return;

  /* Two subtests, one with offset 0 and current_size - 1 bytes, and

     another one with current_size bytes, but offset 1.  */

  for (int shift = 0; shift < 2; ++shift)

    {

      if (test_verbose > 0)

        printf ("info:   shift=%d\n", shift);

      xftruncate (infd, 0);

      xlseek (infd, 0, SEEK_SET);

      xwrite (infd, random_data, current_size - !shift);

      if (do_inoff)

        {

          inoff = shift;

          xlseek (infd, 2, SEEK_SET);

        }

      else

        {

          inoff = 3;

          xlseek (infd, shift, SEEK_SET);

        }

      ftruncate (outfd, 0);

      xlseek (outfd, 0, SEEK_SET);

      outoff = 0;

      /* First call copies current_size - 1 bytes.  */

      TEST_COMPARE (copy_file_range (infd, pinoff, outfd, poutoff,

                                     current_size, 0), current_size - 1);

      char *buffer = xmalloc (current_size);

      TEST_COMPARE (pread64 (outfd, buffer, current_size, 0),

                    current_size - 1);

      TEST_VERIFY (memcmp (buffer, random_data + shift, current_size - 1)

                   == 0);

      free (buffer);

      if (do_inoff)

        {

          TEST_COMPARE (inoff, current_size - 1 + shift);

          TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 2);

        }

      else

        TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), current_size - 1 + shift);

      if (do_outoff)

        {

          TEST_COMPARE (outoff, current_size - 1);

          TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), 0);

        }

      else

        TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), current_size - 1);

      /* First call copies zero bytes.  */

      TEST_COMPARE (copy_file_range (infd, pinoff, outfd, poutoff,

                                     current_size, 0), 0);

      /* And the offsets are unchanged.  */

      if (do_inoff)

        {

          TEST_COMPARE (inoff, current_size - 1 + shift);

          TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 2);

        }

      else

        TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), current_size - 1 + shift);

      if (do_outoff)

        {

          TEST_COMPARE (outoff, current_size - 1);

          TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), 0);

        }

      else

        TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), current_size - 1);

    }

}

/* A named test function.  */

struct test_case

{

  const char *name;

  void (*func) (void);

  bool sizes; /* If true, call the test with different current_size values.  */

};

/* The available test cases.  */

static struct test_case tests[] =

  {

    { "simple_file_copy", simple_file_copy, .sizes = true },

    { "short_copy", short_copy, .sizes = true },

  };

static int

do_test (void)

{

  for (unsigned char *p = random_data; p < array_end (random_data); ++p)

    *p = rand () >> 24;

  infd = create_temp_file ("tst-copy_file_range-in-", &infile);

  outfd = create_temp_file ("tst-copy_file_range-out-", &outfile);

  {

    ssize_t ret = copy_file_range (infd, NULL, outfd, NULL, 0, 0);

    if (ret != 0)

      {

        if (errno == ENOSYS)

          FAIL_UNSUPPORTED ("copy_file_range is not support on this system");

        FAIL_EXIT1 ("copy_file_range probing call: %m");

      }

  }

  xclose (infd);

  xclose (outfd);

  for (do_inoff = 0; do_inoff < 2; ++do_inoff)

    for (do_outoff = 0; do_outoff < 2; ++do_outoff)

      for (struct test_case *test = tests; test < array_end (tests); ++test)

        for (const int *size = typical_sizes;

             size < array_end (typical_sizes); ++size)

          {

            current_size = *size;

            if (test_verbose > 0)

              printf ("info: %s do_inoff=%d do_outoff=%d current_size=%d\n",

                      test->name, do_inoff, do_outoff, current_size);

            inoff = 0;

            if (do_inoff)

              pinoff = &inof;;

            else

              pinoff = NULL;

            outoff = 0;

            if (do_outoff)

              poutoff = &outoff;

            else

              poutoff = NULL;

            infd = xopen (infile, O_RDWR | O_LARGEFILE, 0);

            xftruncate (infd, 0);

            outfd = xopen (outfile, O_RDWR | O_LARGEFILE, 0);

            xftruncate (outfd, 0);

            test->func ();

            xclose (infd);

            xclose (outfd);

            if (!test->sizes)

              /* Skip the other sizes unless they have been

                 requested.  */

              break;

          }

  free (infile);

  free (outfile);

  return 0;

}

#include <support/test-driver.c>