/* Basic tests for pldd program.

   Copyright (C) 2019 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 <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <unistd.h>

#include <stdint.h>

#include <stdbool.h>

#include <array_length.h>

#include <gnu/lib-names.h>

#include <support/subprocess.h>

#include <support/capture_subprocess.h>

#include <support/check.h>

#include <support/support.h>

#include <support/xptrace.h>

#include <support/xunistd.h>

#include <sys/mman.h>

#include <errno.h>

#include <signal.h>

static void

target_process (void *arg)

{

  pause ();

}

static void

pldd_process (void *arg)

{

  pid_t *target_pid_ptr = (pid_t *) arg;

  /* Create a copy of current test to check with pldd.  As the

     target_process is a child of this pldd_process, pldd is also able

     to attach to target_process if YAMA is configured to 1 =

     "restricted ptrace".  */

  struct support_subprocess target = support_subprocess (target_process, NULL);

  /* Store the pid of target-process as do_test needs it in order to

     e.g. terminate it at end of the test.  */

  *target_pid_ptr = target.pid;

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

  char pid[3 * sizeof (uint32_t) + 1];

  snprintf (pid, array_length (pid), "%d", target.pid);

  char *prog = xasprintf ("%s/pldd", support_bindir_prefix);

  /* Run pldd and use the pid of target_process as argument.  */

  execve (prog, (char *const []) { (char *) prog, pid, NULL },

	  (char *const []) { NULL });

  FAIL_EXIT1 ("Returned from execve: errno=%d=%m\n", errno);

}

/* The test runs in a container because pldd does not support tracing

   a binary started by the loader iself (as with testrun.sh).  */

static bool

in_str_list (const char *libname, const char *const strlist[])

{

  for (const char *const *str = strlist; *str != NULL; str++)

    if (strcmp (libname, *str) == 0)

      return true;

  return false;

}

static int

do_test (void)

{

  /* Check if our subprocess can be debugged with ptrace.  */

  {

    int ptrace_scope = support_ptrace_scope ();

    if (ptrace_scope >= 2)

      FAIL_UNSUPPORTED ("/proc/sys/kernel/yama/ptrace_scope >= 2");

  }

  pid_t *target_pid_ptr = (pid_t *) xmmap (NULL, sizeof (pid_t),

					   PROT_READ | PROT_WRITE,

					   MAP_SHARED | MAP_ANONYMOUS, -1);

  /* Run 'pldd' on test subprocess which will be created in pldd_process.

     The pid of the subprocess will be written to target_pid_ptr.  */

  struct support_capture_subprocess pldd;

  pldd = support_capture_subprocess (pldd_process, target_pid_ptr);

  support_capture_subprocess_check (&pldd, "pldd", 0, sc_allow_stdout);

  /* Check 'pldd' output.  The test is expected to be linked against only

     loader and libc.  */

  {

    pid_t pid;

    char buffer[512];

#define STRINPUT(size) "%" # size "s"

    FILE *out = fmemopen (pldd.out.buffer, pldd.out.length, "r");

    TEST_VERIFY (out != NULL);

    /* First line is in the form of <pid>: <full path of executable>  */

    TEST_COMPARE (fscanf (out, "%u: " STRINPUT (512), &pid, buffer), 2);

    TEST_COMPARE (pid, *target_pid_ptr);

    TEST_COMPARE (strcmp (basename (buffer), "tst-pldd"), 0);

    /* It expects only one loader and libc loaded by the program.  */

    bool interpreter_found = false, libc_found = false;

    while (fgets (buffer, array_length (buffer), out) != NULL)

      {

	/* Ignore vDSO.  */

	if (buffer[0] != '/')

	  continue;

	/* Remove newline so baseline (buffer) can compare against the

	   LD_SO and LIBC_SO macros unmodified.  */

	if (buffer[strlen(buffer)-1] == '\n')

	  buffer[strlen(buffer)-1] = '\0';

	const char *libname = basename (buffer);

	/* It checks for default names in case of build configure with

	   --enable-hardcoded-path-in-tests (BZ #24506).  */

	if (in_str_list (libname,

			 (const char *const []) { "ld.so", LD_SO, NULL }))

	  {

	    TEST_COMPARE (interpreter_found, false);

	    interpreter_found = true;

	    continue;

	  }

	if (in_str_list (libname,

			 (const char *const []) { "libc.so", LIBC_SO, NULL }))

	  {

	    TEST_COMPARE (libc_found, false);

	    libc_found = true;

	    continue;

	  }

      }

    TEST_COMPARE (interpreter_found, true);

    TEST_COMPARE (libc_found, true);

    fclose (out);

  }

  support_capture_subprocess_free (&pldd);

  if (kill (*target_pid_ptr, SIGKILL) != 0)

    FAIL_EXIT1 ("Unable to kill target_process: errno=%d=%m\n", errno);

  xmunmap (target_pid_ptr, sizeof (pid_t));

  return 0;

}

#include <support/test-driver.c>