/* Run a test case in an isolated namespace.

   Copyright (C) 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/>.  */

#define _FILE_OFFSET_BITS 64

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sched.h>

#include <sys/syscall.h>

#include <unistd.h>

#include <sys/types.h>

#include <dirent.h>

#include <string.h>

#include <sys/stat.h>

#include <sys/fcntl.h>

#include <sys/file.h>

#include <sys/wait.h>

#include <stdarg.h>

#include <sys/sysmacros.h>

#include <ctype.h>

#include <utime.h>

#include <errno.h>

#include <error.h>

#include <libc-pointer-arith.h>

#ifdef __linux__

#include <sys/mount.h>

#endif

#include <support/support.h>

#include <support/xunistd.h>

#include "check.h"

#include "test-driver.h"

#ifndef __linux__

#define mount(s,t,fs,f,d) no_mount()

int no_mount (void)

{

  FAIL_UNSUPPORTED("mount not supported; port needed");

}

#endif

int verbose = 0;

/* Running a test in a container is tricky.  There are two main

   categories of things to do:

   1. "Once" actions, like setting up the container and doing an

      install into it.

   2. "Per-test" actions, like copying in support files and

      configuring the container.

   "Once" actions:

   * mkdir $buildroot/testroot.pristine/

   * install into it

     * default glibc install

     * create /bin for /bin/sh

     * create $(complocaledir) so localedef tests work with default paths.

     * install /bin/sh, /bin/echo, and /bin/true.

   * rsync to $buildroot/testroot.root/

   "Per-test" actions:

   * maybe rsync to $buildroot/testroot.root/

   * copy support files and test binary

   * chroot/unshare

   * set up any mounts (like /proc)

   Magic files:

   For test $srcdir/foo/mytest.c we look for $srcdir/foo/mytest.root

   and, if found...

   * mytest.root/ is rsync'd into container

   * mytest.root/preclean.req causes fresh rsync (with delete) before

     test if present

   * mytest.root/mytest.script has a list of "commands" to run:

       syntax:

         # comment

         su

         mv FILE FILE

	 cp FILE FILE

	 rm FILE

	 cwd PATH

	 exec FILE

	 mkdirp MODE DIR

       variables:

	 $B/ build dir, equivalent to $(common-objpfx)

	 $S/ source dir, equivalent to $(srcdir)

	 $I/ install dir, equivalent to $(prefix)

	 $L/ library dir (in container), equivalent to $(libdir)

	 $complocaledir/ compiled locale dir, equivalent to $(complocaledir)

	 / container's root

	 If FILE begins with any of these variables then they will be

	 substituted for the described value.

	 The goal is to expose as many of the runtime's configured paths

	 via variables so they can be used to setup the container environment

	 before execution reaches the test.

       details:

         - '#': A comment.

         - 'su': Enables running test as root in the container.

         - 'mv': A minimal move files command.

         - 'cp': A minimal copy files command.

         - 'rm': A minimal remove files command.

	 - 'cwd': set test working directory

	 - 'exec': change test binary location (may end in /)

	 - 'mkdirp': A minimal "mkdir -p FILE" command.

   * mytest.root/postclean.req causes fresh rsync (with delete) after

     test if present

   Note that $srcdir/foo/mytest.script may be used instead of a

   $srcdir/foo/mytest.root/mytest.script in the sysroot template, if

   there is no other reason for a sysroot.

   Design goals:

   * independent of other packages which may not be installed (like

     rsync or Docker, or even "cp")

   * Simple, easy to review code (i.e. prefer simple naive code over

     complex efficient code)

   * The current implementation ist parallel-make-safe, but only in

     that it uses a lock to prevent parallel access to the testroot.  */

/* Utility Functions */

/* Like xunlink, but it's OK if the file already doesn't exist.  */

void

maybe_xunlink (const char *path)

{

  int rv = unlink (path);

  if (rv < 0 && errno != ENOENT)

    FAIL_EXIT1 ("unlink (\"%s\"): %m", path);

}

/* Like xmkdir, but it's OK if the directory already exists.  */

void

maybe_xmkdir (const char *path, mode_t mode)

{

  struct stat st;

  if (stat (path, &st) == 0

      && S_ISDIR (st.st_mode))

    return;

  xmkdir (path, mode);

}

/* Temporarily concatenate multiple strings into one.  Allows up to 10

   temporary results; use xstrdup () if you need them to be

   permanent.  */

static char *

concat (const char *str, ...)

{

  /* Assume initialized to NULL/zero.  */

  static char *bufs[10];

  static size_t buflens[10];

  static int bufn = 0;

  int n;

  size_t len;

  va_list ap, ap2;

  char *cp;

  char *next;

  va_start (ap, str);

  va_copy (ap2, ap);

  n = bufn;

  bufn = (bufn + 1) % 10;

  len = strlen (str);

  while ((next = va_arg (ap, char *)) != NULL)

    len = len + strlen (next);

  va_end (ap);

  if (bufs[n] == NULL)

    {

      bufs[n] = xmalloc (len + 1); /* NUL */

      buflens[n] = len + 1;

    }

  else if (buflens[n] < len + 1)

    {

      bufs[n] = xrealloc (bufs[n], len + 1); /* NUL */

      buflens[n] = len + 1;

    }

  strcpy (bufs[n], str);

  cp = strchr (bufs[n], '\0');

  while ((next = va_arg (ap2, char *)) != NULL)

    {

      strcpy (cp, next);

      cp = strchr (cp, '\0');

    }

  *cp = 0;

  va_end (ap2);

  return bufs[n];

}

/* Try to mount SRC onto DEST.  */

static void

trymount (const char *src, const char *dest)

{

  if (mount (src, dest, "", MS_BIND, NULL) < 0)

    FAIL_EXIT1 ("can't mount %s onto %s\n", src, dest);

}

/* Special case of above for devices like /dev/zero where we have to

   mount a device over a device, not a directory over a directory.  */

static void

devmount (const char *new_root_path, const char *which)

{

  int fd;

  fd = open (concat (new_root_path, "/dev/", which, NULL),

	     O_CREAT | O_TRUNC | O_RDWR, 0777);

  xclose (fd);

  trymount (concat ("/dev/", which, NULL),

	    concat (new_root_path, "/dev/", which, NULL));

}

/* Returns true if the string "looks like" an environement variable

   being set.  */

static int

is_env_setting (const char *a)

{

  int count_name = 0;

  while (*a)

    {

      if (isalnum (*a) || *a == '_')

	++count_name;

      else if (*a == '=' && count_name > 0)

	return 1;

      else

	return 0;

      ++a;

    }

  return 0;

}

/* Break the_line into words and store in the_words.  Max nwords,

   returns actual count.  */

static int

tokenize (char *the_line, char **the_words, int nwords)

{

  int rv = 0;

  while (nwords > 0)

    {

      /* Skip leading whitespace, if any.  */

      while (*the_line && isspace (*the_line))

	++the_line;

      /* End of line?  */

      if (*the_line == 0)

	return rv;

      /* THE_LINE points to a non-whitespace character, so we have a

	 word.  */

      *the_words = the_line;

      ++the_words;

      nwords--;

      ++rv;

      /* Skip leading whitespace, if any.  */

      while (*the_line && ! isspace (*the_line))

	++the_line;

      /* We now point at the trailing NUL *or* some whitespace.  */

      if (*the_line == 0)

	return rv;

      /* It was whitespace, skip and keep tokenizing.  */

      *the_line++ = 0;

    }

  /* We get here if we filled the words buffer.  */

  return rv;

}

/* Mini-RSYNC implementation.  Optimize later.      */

/* A few routines for an "rsync buffer" which stores the paths we're

   working on.  We continuously grow and shrink the paths in each

   buffer so there's lot of re-use.  */

/* We rely on "initialized to zero" to set these up.  */

typedef struct

{

  char *buf;

  size_t len;

  size_t size;

} path_buf;

static path_buf spath, dpath;

static void

r_setup (char *path, path_buf * pb)

{

  size_t len = strlen (path);

  if (pb->buf == NULL || pb->size < len + 1)

    {

      /* Round up.  This is an arbitrary number, just to keep from

	 reallocing too often.  */

      size_t sz = ALIGN_UP (len + 1, 512);

      if (pb->buf == NULL)

	pb->buf = (char *) xmalloc (sz);

      else

	pb->buf = (char *) xrealloc (pb->buf, sz);

      if (pb->buf == NULL)

	FAIL_EXIT1 ("Out of memory while rsyncing\n");

      pb->size = sz;

    }

  strcpy (pb->buf, path);

  pb->len = len;

}

static void

r_append (const char *path, path_buf * pb)

{

  size_t len = strlen (path) + pb->len;

  if (pb->size < len + 1)

    {

      /* Round up */

      size_t sz = ALIGN_UP (len + 1, 512);

      pb->buf = (char *) xrealloc (pb->buf, sz);

      if (pb->buf == NULL)

	FAIL_EXIT1 ("Out of memory while rsyncing\n");

      pb->size = sz;

    }

  strcpy (pb->buf + pb->len, path);

  pb->len = len;

}

static int

file_exists (char *path)

{

  struct stat st;

  if (lstat (path, &st) == 0)

    return 1;

  return 0;

}

static void

recursive_remove (char *path)

{

  pid_t child;

  int status;

  child = fork ();

  switch (child) {

  case -1:

    perror("fork");

    FAIL_EXIT1 ("Unable to fork");

  case 0:

    /* Child.  */

    execlp ("rm", "rm", "-rf", path, NULL);

    FAIL_EXIT1 ("exec rm: %m");

  default:

    /* Parent.  */

    waitpid (child, &status, 0);

    /* "rm" would have already printed a suitable error message.  */

    if (! WIFEXITED (status)

	|| WEXITSTATUS (status) != 0)

      FAIL_EXIT1 ("exec child returned status: %d", status);

    break;

  }

}

/* Used for both rsync and the mytest.script "cp" command.  */

static void

copy_one_file (const char *sname, const char *dname)

{

  int sfd, dfd;

  struct stat st;

  struct utimbuf times;

  sfd = open (sname, O_RDONLY);

  if (sfd < 0)

    FAIL_EXIT1 ("unable to open %s for reading\n", sname);

  if (fstat (sfd, &st) < 0)

    FAIL_EXIT1 ("unable to fstat %s\n", sname);

  dfd = open (dname, O_WRONLY | O_TRUNC | O_CREAT, 0600);

  if (dfd < 0)

    FAIL_EXIT1 ("unable to open %s for writing\n", dname);

  xcopy_file_range (sfd, 0, dfd, 0, st.st_size, 0);

  xclose (sfd);

  xclose (dfd);

  if (chmod (dname, st.st_mode & 0777) < 0)

    FAIL_EXIT1 ("chmod %s: %s\n", dname, strerror (errno));

  times.actime = st.st_atime;

  times.modtime = st.st_mtime;

  if (utime (dname, &times) < 0)

    FAIL_EXIT1 ("utime %s: %s\n", dname, strerror (errno));

}

/* We don't check *everything* about the two files to see if a copy is

   needed, just the minimum to make sure we get the latest copy.  */

static int

need_sync (char *ap, char *bp, struct stat *a, struct stat *b)

{

  if ((a->st_mode & S_IFMT) != (b->st_mode & S_IFMT))

    return 1;

  if (S_ISLNK (a->st_mode))

    {

      int rv;

      char *al, *bl;

      if (a->st_size != b->st_size)

	return 1;

      al = xreadlink (ap);

      bl = xreadlink (bp);

      rv = strcmp (al, bl);

      free (al);

      free (bl);

      if (rv == 0)

	return 0; /* links are same */

      return 1; /* links differ */

    }

  if (verbose)

    {

      if (a->st_size != b->st_size)

	printf ("SIZE\n");

      if ((a->st_mode & 0777) != (b->st_mode & 0777))

	printf ("MODE\n");

      if (a->st_mtime != b->st_mtime)

	printf ("TIME\n");

    }

  if (a->st_size == b->st_size

      && ((a->st_mode & 0777) == (b->st_mode & 0777))

      && a->st_mtime == b->st_mtime)

    return 0;

  return 1;

}

static void

rsync_1 (path_buf * src, path_buf * dest, int and_delete)

{

  DIR *dir;

  struct dirent *de;

  struct stat s, d;

  r_append ("/", src);

  r_append ("/", dest);

  if (verbose)

    printf ("sync %s to %s %s\n", src->buf, dest->buf,

	    and_delete ? "and delete" : "");

  size_t staillen = src->len;

  size_t dtaillen = dest->len;

  dir = opendir (src->buf);

  while ((de = readdir (dir)) != NULL)

    {

      if (strcmp (de->d_name, ".") == 0

	  || strcmp (de->d_name, "..") == 0)

	continue;

      src->len = staillen;

      r_append (de->d_name, src);

      dest->len = dtaillen;

      r_append (de->d_name, dest);

      s.st_mode = ~0;

      d.st_mode = ~0;

      if (lstat (src->buf, &s) != 0)

	FAIL_EXIT1 ("%s obtained by readdir, but stat failed.\n", src->buf);

      /* It's OK if this one fails, since we know the file might be

	 missing.  */

      lstat (dest->buf, &d);

      if (! need_sync (src->buf, dest->buf, &s, &d))

	{

	  if (S_ISDIR (s.st_mode))

	    rsync_1 (src, dest, and_delete);

	  continue;

	}

      if (d.st_mode != ~0)

	switch (d.st_mode & S_IFMT)

	  {

	  case S_IFDIR:

	    if (!S_ISDIR (s.st_mode))

	      {

		if (verbose)

		  printf ("-D %s\n", dest->buf);

		recursive_remove (dest->buf);

	      }

	    break;

	  default:

	    if (verbose)

	      printf ("-F %s\n", dest->buf);

	    maybe_xunlink (dest->buf);

	    break;

	  }

      switch (s.st_mode & S_IFMT)

	{

	case S_IFREG:

	  if (verbose)

	    printf ("+F %s\n", dest->buf);

	  copy_one_file (src->buf, dest->buf);

	  break;

	case S_IFDIR:

	  if (verbose)

	    printf ("+D %s\n", dest->buf);

	  maybe_xmkdir (dest->buf, (s.st_mode & 0777) | 0700);

	  rsync_1 (src, dest, and_delete);

	  break;

	case S_IFLNK:

	  {

	    char *lp;

	    if (verbose)

	      printf ("+L %s\n", dest->buf);

	    lp = xreadlink (src->buf);

	    xsymlink (lp, dest->buf);

	    free (lp);

	    break;

	  }

	default:

	  break;

	}

    }

  closedir (dir);

  src->len = staillen;

  src->buf[staillen] = 0;

  dest->len = dtaillen;

  dest->buf[dtaillen] = 0;

  if (!and_delete)

    return;

  /* The rest of this function removes any files/directories in DEST

     that do not exist in SRC.  This is triggered as part of a

     preclean or postsclean step.  */

  dir = opendir (dest->buf);

  while ((de = readdir (dir)) != NULL)

    {

      if (strcmp (de->d_name, ".") == 0

	  || strcmp (de->d_name, "..") == 0)

	continue;

      src->len = staillen;

      r_append (de->d_name, src);

      dest->len = dtaillen;

      r_append (de->d_name, dest);

      s.st_mode = ~0;

      d.st_mode = ~0;

      lstat (src->buf, &s);

      if (lstat (dest->buf, &d) != 0)

	FAIL_EXIT1 ("%s obtained by readdir, but stat failed.\n", dest->buf);

      if (s.st_mode == ~0)

	{

	  /* dest exists and src doesn't, clean it.  */

	  switch (d.st_mode & S_IFMT)

	    {

	    case S_IFDIR:

	      if (!S_ISDIR (s.st_mode))

		{

		  if (verbose)

		    printf ("-D %s\n", dest->buf);

		  recursive_remove (dest->buf);

		}

	      break;

	    default:

	      if (verbose)

		printf ("-F %s\n", dest->buf);

	      maybe_xunlink (dest->buf);

	      break;

	    }

	}

    }

  closedir (dir);

}

static void

rsync (char *src, char *dest, int and_delete)

{

  r_setup (src, &spath);

  r_setup (dest, &dpath);

  rsync_1 (&spath, &dpath, and_delete);

}

/* See if we can detect what the user needs to do to get unshare

   support working for us.  */

void

check_for_unshare_hints (void)

{

  FILE *f;

  int i;

  /* Default Debian Linux disables user namespaces, but allows a way

     to enable them.  */

  f = fopen ("/proc/sys/kernel/unprivileged_userns_clone", "r");

  if (f != NULL)

    {

      i = 99; /* Sentinel.  */

      fscanf (f, "%d", &i);

      if (i == 0)

	{

	  printf ("To enable test-container, please run this as root:\n");

	  printf ("  echo 1 > /proc/sys/kernel/unprivileged_userns_clone\n");

	}

      fclose (f);

      return;

    }

  /* ALT Linux has an alternate way of doing the same.  */

  f = fopen ("/proc/sys/kernel/userns_restrict", "r");

  if (f != NULL)

    {

      i = 99; /* Sentinel.  */

      fscanf (f, "%d", &i);

      if (i == 1)

	{

	  printf ("To enable test-container, please run this as root:\n");

	  printf ("  echo 0 > /proc/sys/kernel/userns_restrict\n");

	}

      fclose (f);

      return;

    }

}

int

main (int argc, char **argv)

{

  pid_t child;

  char *pristine_root_path;

  char *new_root_path;

  char *new_cwd_path;

  char *new_objdir_path;

  char *new_srcdir_path;

  char **new_child_proc;

  char *new_child_exec;

  char *command_root;

  char *command_base;

  char *command_basename;

  char *so_base;

  int do_postclean = 0;

  char *change_cwd = NULL;

  int pipes[2];

  char pid_buf[20];

  uid_t original_uid;

  gid_t original_gid;

  /* If set, the test runs as root instead of the user running the testsuite.  */

  int be_su = 0;

  int UMAP;

  int GMAP;

  /* Used for "%lld %lld 1" so need not be large.  */

  char tmp[100];

  struct stat st;

  int lock_fd;

  setbuf (stdout, NULL);

  /* The command line we're expecting looks like this:

     env <set some vars> ld.so <library path> test-binary

     We need to peel off any "env" or "ld.so" portion of the command

     line, and keep track of which env vars we should preserve and

     which we drop.  */

  if (argc < 2)

    {

      fprintf (stderr, "Usage: test-container <program to run> <args...>\n");

      exit (1);

    }

  if (strcmp (argv[1], "-v") == 0)

    {

      verbose = 1;

      ++argv;

      --argc;

    }

  if (strcmp (argv[1], "env") == 0)

    {

      ++argv;

      --argc;

      while (is_env_setting (argv[1]))

	{

	  /* If there are variables we do NOT want to propogate, this

	     is where the test for them goes.  */

	    {

	      /* Need to keep these.  Note that putenv stores a

	         pointer to our argv.  */

	      putenv (argv[1]);

	    }

	  ++argv;

	  --argc;

	}

    }

  if (strcmp (argv[1], support_objdir_elf_ldso) == 0)

    {

      ++argv;

      --argc;

      while (argv[1][0] == '-')

	{

	  if (strcmp (argv[1], "--library-path") == 0)

	    {

	      ++argv;

	      --argc;

	    }

	  ++argv;

	  --argc;

	}

    }

  pristine_root_path = xstrdup (concat (support_objdir_root,

				       "/testroot.pristine", NULL));

  new_root_path = xstrdup (concat (support_objdir_root,

				  "/testroot.root", NULL));

  new_cwd_path = get_current_dir_name ();

  new_child_proc = argv + 1;

  new_child_exec = argv[1];

  lock_fd = open (concat (pristine_root_path, "/lock.fd", NULL),

		 O_CREAT | O_TRUNC | O_RDWR, 0666);

  if (lock_fd < 0)

    FAIL_EXIT1 ("Cannot create testroot lock.\n");

  while (flock (lock_fd, LOCK_EX) != 0)

    {

      if (errno != EINTR)

	FAIL_EXIT1 ("Cannot lock testroot.\n");

    }

  xmkdirp (new_root_path, 0755);

  /* We look for extra setup info in a subdir in the same spot as the

     test, with the same name but a ".root" extension.  This is that

     directory.  We try to look in the source tree if the path we're

     given refers to the build tree, but we rely on the path to be

     absolute.  This is what the glibc makefiles do.  */

  command_root = concat (argv[1], ".root", NULL);

  if (strncmp (command_root, support_objdir_root,

	       strlen (support_objdir_root)) == 0

      && command_root[strlen (support_objdir_root)] == '/')

    command_root = concat (support_srcdir_root,

			   argv[1] + strlen (support_objdir_root),

			   ".root", NULL);

  command_root = xstrdup (command_root);

  /* This cuts off the ".root" we appended above.  */

  command_base = xstrdup (command_root);

  command_base[strlen (command_base) - 5] = 0;

  /* This is the basename of the test we're running.  */

  command_basename = strrchr (command_base, '/');

  if (command_basename == NULL)

    command_basename = command_base;

  else

    ++command_basename;

  /* Shared object base directory.  */

  so_base = xstrdup (argv[1]);

  if (strrchr (so_base, '/') != NULL)

    strrchr (so_base, '/')[1] = 0;

  if (file_exists (concat (command_root, "/postclean.req", NULL)))

    do_postclean = 1;

  rsync (pristine_root_path, new_root_path,

	 file_exists (concat (command_root, "/preclean.req", NULL)));

  if (stat (command_root, &st) >= 0

      && S_ISDIR (st.st_mode))

    rsync (command_root, new_root_path, 0);

  new_objdir_path = xstrdup (concat (new_root_path,

				    support_objdir_root, NULL));

  new_srcdir_path = xstrdup (concat (new_root_path,

				    support_srcdir_root, NULL));

  /* new_cwd_path starts with '/' so no "/" needed between the two.  */

  xmkdirp (concat (new_root_path, new_cwd_path, NULL), 0755);

  xmkdirp (new_srcdir_path, 0755);

  xmkdirp (new_objdir_path, 0755);

  original_uid = getuid ();

  original_gid = getgid ();

  /* Handle the cp/mv/rm "script" here.  */

  {

    char *the_line = NULL;

    size_t line_len = 0;

    char *fname = concat (command_root, "/",

			  command_basename, ".script", NULL);

    char *the_words[3];

    FILE *f = fopen (fname, "r");

    if (verbose && f)

      fprintf (stderr, "running %s\n", fname);

    if (f == NULL)

      {

	/* Try foo.script instead of foo.root/foo.script, as a shortcut.  */

	fname = concat (command_base, ".script", NULL);

	f = fopen (fname, "r");

	if (verbose && f)

	  fprintf (stderr, "running %s\n", fname);

      }

    /* Note that we do NOT look for a Makefile-generated foo.script in

       the build directory.  If that is ever needed, this is the place

       to add it.  */

    /* This is where we "interpret" the mini-script which is <test>.script.  */

    if (f != NULL)

      {

	while (getline (&the_line, &line_len, f) > 0)

	  {

	    int nt = tokenize (the_line, the_words, 3);

	    int i;