/* Test capturing output from a subprocess.

   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 <stdbool.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <support/capture_subprocess.h>

#include <support/check.h>

#include <support/support.h>

#include <support/temp_file.h>

#include <sys/wait.h>

#include <unistd.h>

#include <paths.h>

#include <getopt.h>

#include <limits.h>

#include <errno.h>

#include <array_length.h>

/* Nonzero if the program gets called via 'exec'.  */

static int restart;

/* Hold the four initial argument used to respawn the process.  */

static char *initial_argv[5];

/* Write one byte at *P to FD and advance *P.  Do nothing if *P is

   '\0'.  */

static void

transfer (const unsigned char **p, int fd)

{

  if (**p != '\0')

    {

      TEST_VERIFY (write (fd, *p, 1) == 1);

      ++*p;

    }

}

/* Determine the order in which stdout and stderr are written.  */

enum write_mode { out_first, err_first, interleave,

                  write_mode_last =  interleave };

static const char *

write_mode_to_str (enum write_mode mode)

{

  switch (mode)

    {

    case out_first:  return "out_first";

    case err_first:  return "err_first";

    case interleave: return "interleave";

    default:         return "write_mode_last";

    }

}

static enum write_mode

str_to_write_mode (const char *mode)

{

  if (strcmp (mode, "out_first") == 0)

    return out_first;

  else if (strcmp (mode, "err_first") == 0)

    return err_first;

  else if (strcmp (mode, "interleave") == 0)

    return interleave;

  return write_mode_last;

}

/* Describe what to write in the subprocess.  */

struct test

{

  char *out;

  char *err;

  enum write_mode write_mode;

  int signal;

  int status;

};

_Noreturn static void

test_common (const struct test *test)

{

  bool mode_ok = false;

  switch (test->write_mode)

    {

    case out_first:

      TEST_VERIFY (fputs (test->out, stdout) >= 0);

      TEST_VERIFY (fflush (stdout) == 0);

      TEST_VERIFY (fputs (test->err, stderr) >= 0);

      TEST_VERIFY (fflush (stderr) == 0);

      mode_ok = true;

      break;

    case err_first:

      TEST_VERIFY (fputs (test->err, stderr) >= 0);

      TEST_VERIFY (fflush (stderr) == 0);

      TEST_VERIFY (fputs (test->out, stdout) >= 0);

      TEST_VERIFY (fflush (stdout) == 0);

      mode_ok = true;

      break;

    case interleave:

      {

        const unsigned char *pout = (const unsigned char *) test->out;

        const unsigned char *perr = (const unsigned char *) test->err;

        do

          {

            transfer (&pout, STDOUT_FILENO);

            transfer (&perr, STDERR_FILENO);

          }

        while (*pout != '\0' || *perr != '\0');

      }

      mode_ok = true;

      break;

    }

  TEST_VERIFY (mode_ok);

  if (test->signal != 0)

    raise (test->signal);

  exit (test->status);

}

static int

parse_int (const char *str)

{

  char *endptr;

  long int ret = strtol (str, &endptr, 10);

  TEST_COMPARE (errno, 0);

  TEST_VERIFY (ret >= 0 && ret <= INT_MAX);

  return ret;

}

/* For use with support_capture_subprogram.  */

_Noreturn static void

handle_restart (char *out, char *err, const char *write_mode,

               const char *signal, const char *status)

{

  struct test test =

    {

      out,

      err,

      str_to_write_mode (write_mode),

      parse_int (signal),

      parse_int (status)

    };

  test_common (&test);

}

/* For use with support_capture_subprocess.  */

_Noreturn static void

callback (void *closure)

{

  const struct test *test = closure;

  test_common (test);

}

/* Create a heap-allocated random string of letters.  */

static char *

random_string (size_t length)

{

  char *result = xmalloc (length + 1);

  for (size_t i = 0; i < length; ++i)

    result[i] = 'a' + (rand () % 26);

  result[length] = '\0';

  return result;

}

/* Check that the specific stream from the captured subprocess matches

   expectations.  */

static void

check_stream (const char *what, const struct xmemstream *stream,

              const char *expected)

{

  if (strcmp (stream->buffer, expected) != 0)

    {

      support_record_failure ();

      printf ("error: captured %s data incorrect\n"

              "  expected: %s\n"

              "  actual:   %s\n",

              what, expected, stream->buffer);

    }

  if (stream->length != strlen (expected))

    {

      support_record_failure ();

      printf ("error: captured %s data length incorrect\n"

              "  expected: %zu\n"

              "  actual:   %zu\n",

              what, strlen (expected), stream->length);

    }

}

static struct support_capture_subprocess

do_subprocess (struct test *test)

{

  return support_capture_subprocess (callback, test);

}

static struct support_capture_subprocess

do_subprogram (const struct test *test)

{

  /* Three digits per byte plus null terminator.  */

  char signalstr[3 * sizeof(int) + 1];

  snprintf (signalstr, sizeof (signalstr), "%d", test->signal);

  char statusstr[3 * sizeof(int) + 1];

  snprintf (statusstr, sizeof (statusstr), "%d", test->status);

  int argc = 0;

  enum {

    /* 4 elements from initial_argv (path to ld.so, '--library-path', the

       path', and application name'), 2 for restart argument ('--direct',

       '--restart'), 5 arguments plus NULL.  */

    argv_size = 12

  };

  char *args[argv_size];

  for (char **arg = initial_argv; *arg != NULL; arg++)

    args[argc++] = *arg;

  args[argc++] = (char*) "--direct";

  args[argc++] = (char*) "--restart";

  args[argc++] = test->out;

  args[argc++] = test->err;

  args[argc++] = (char*) write_mode_to_str (test->write_mode);

  args[argc++] = signalstr;

  args[argc++] = statusstr;

  args[argc]   = NULL;

  TEST_VERIFY (argc < argv_size);

  return support_capture_subprogram (args[0], args);

}

enum test_type

{

  subprocess,

  subprogram,

};

static int

do_multiple_tests (enum test_type type)

{

  const int lengths[] = {0, 1, 17, 512, 20000, -1};

  /* Test multiple combinations of support_capture_sub{process,program}.

     length_idx_stdout: Index into the lengths array above,

       controls how many bytes are written by the subprocess to

       standard output.

     length_idx_stderr: Same for standard error.

     write_mode: How standard output and standard error writes are

       ordered.

     signal: Exit with no signal if zero, with SIGTERM if one.

     status: Process exit status: 0 if zero, 3 if one.  */

  for (int length_idx_stdout = 0; lengths[length_idx_stdout] >= 0;

       ++length_idx_stdout)

    for (int length_idx_stderr = 0; lengths[length_idx_stderr] >= 0;

         ++length_idx_stderr)

      for (int write_mode = 0; write_mode < write_mode_last; ++write_mode)

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

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

            {

              struct test test =

                {

                  .out = random_string (lengths[length_idx_stdout]),

                  .err = random_string (lengths[length_idx_stderr]),

                  .write_mode = write_mode,

                  .signal = signal * SIGTERM, /* 0 or SIGTERM.  */

                  .status = status * 3,       /* 0 or 3.  */

                };

              TEST_VERIFY (strlen (test.out) == lengths[length_idx_stdout]);

              TEST_VERIFY (strlen (test.err) == lengths[length_idx_stderr]);

             struct support_capture_subprocess result

               = type == subprocess ? do_subprocess (&test)

                                    : do_subprogram (&test);

              check_stream ("stdout", &result.out, test.out);

              check_stream ("stderr", &result.err, test.err);

              /* Allowed output for support_capture_subprocess_check.  */

              int check_allow = 0;

              if (lengths[length_idx_stdout] > 0)

                check_allow |= sc_allow_stdout;

              if (lengths[length_idx_stderr] > 0)

                check_allow |= sc_allow_stderr;

              if (check_allow == 0)

                check_allow = sc_allow_none;

              if (test.signal != 0)

                {

                  TEST_VERIFY (WIFSIGNALED (result.status));

                  TEST_VERIFY (WTERMSIG (result.status) == test.signal);

                  support_capture_subprocess_check (&result, "signal",

                                                    -SIGTERM, check_allow);

                }

              else

                {

                  TEST_VERIFY (WIFEXITED (result.status));

                  TEST_VERIFY (WEXITSTATUS (result.status) == test.status);

                  support_capture_subprocess_check (&result, "exit",

                                                    test.status, check_allow);

                }

              support_capture_subprocess_free (&result);

              free (test.out);

              free (test.err);

            }

  return 0;

}

static int

do_test (int argc, char *argv[])

{

  /* We must have either:

     - one or four parameters if called initially:

       + argv[1]: path for ld.so        optional

       + argv[2]: "--library-path"      optional

       + argv[3]: the library path      optional

       + argv[4]: the application name

     - six parameters left if called through re-execution:

       + argv[1]: the application name

       + argv[2]: the stdout to print

       + argv[3]: the stderr to print

       + argv[4]: the write mode to use

       + argv[5]: the signal to issue

       + argv[6]: the exit status code to use

     * When built with --enable-hardcoded-path-in-tests or issued without

       using the loader directly.

  */

  if (argc != (restart ? 6 : 5) && argc != (restart ? 6 : 2))

    FAIL_EXIT1 ("wrong number of arguments (%d)", argc);

  if (restart)

    {

      handle_restart (argv[1],  /* stdout  */

                     argv[2],  /* stderr  */

                     argv[3],  /* write_mode  */

                     argv[4],  /* signal  */

                     argv[5]); /* status  */

    }

  initial_argv[0] = argv[1]; /* path for ld.so  */

  initial_argv[1] = argv[2]; /* "--library-path"  */

  initial_argv[2] = argv[3]; /* the library path  */

  initial_argv[3] = argv[4]; /* the application name  */

  initial_argv[4] = NULL;

  do_multiple_tests (subprocess);

  do_multiple_tests (subprogram);

  return 0;

}

#define CMDLINE_OPTIONS \

  { "restart", no_argument, &restart, 1 },

#define TEST_FUNCTION_ARGV do_test

#include <support/test-driver.c>