Adding upstream version 8.32.upstream/8.32upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 431 insertions, 0 deletions

diff --git a/src/chroot.c b/src/chroot.c
new file mode 100644
index 0000000..02081e5
--- /dev/null
+++ b/src/chroot.c
@@ -0,0 +1,431 @@
+/* chroot -- run command or shell with special root directory
+   Copyright (C) 1995-2020 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Roland McGrath.  */
+
+#include <config.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <grp.h>
+
+#include "system.h"
+#include "die.h"
+#include "error.h"
+#include "ignore-value.h"
+#include "mgetgroups.h"
+#include "quote.h"
+#include "root-dev-ino.h"
+#include "userspec.h"
+#include "xstrtol.h"
+
+/* The official name of this program (e.g., no 'g' prefix).  */
+#define PROGRAM_NAME "chroot"
+
+#define AUTHORS proper_name ("Roland McGrath")
+
+#ifndef MAXGID
+# define MAXGID GID_T_MAX
+#endif
+
+static inline bool uid_unset (uid_t uid) { return uid == (uid_t) -1; }
+static inline bool gid_unset (gid_t gid) { return gid == (gid_t) -1; }
+#define uid_set(x) (!uid_unset (x))
+#define gid_set(x) (!gid_unset (x))
+
+enum
+{
+  GROUPS = UCHAR_MAX + 1,
+  USERSPEC,
+  SKIP_CHDIR
+};
+
+static struct option const long_opts[] =
+{
+  {"groups", required_argument, NULL, GROUPS},
+  {"userspec", required_argument, NULL, USERSPEC},
+  {"skip-chdir", no_argument, NULL, SKIP_CHDIR},
+  {GETOPT_HELP_OPTION_DECL},
+  {GETOPT_VERSION_OPTION_DECL},
+  {NULL, 0, NULL, 0}
+};
+
+#if ! HAVE_SETGROUPS
+/* At least Interix lacks supplemental group support.  */
+static int
+setgroups (size_t size, gid_t const *list _GL_UNUSED)
+{
+  if (size == 0)
+    {
+      /* Return success when clearing supplemental groups
+         as ! HAVE_SETGROUPS should only be the case on
+         platforms that don't support supplemental groups.  */
+      return 0;
+    }
+  else
+    {
+      errno = ENOTSUP;
+      return -1;
+    }
+}
+#endif
+
+/* Determine the group IDs for the specified supplementary GROUPS,
+   which is a comma separated list of supplementary groups (names or numbers).
+   Allocate an array for the parsed IDs and store it in PGIDS,
+   which may be allocated even on parse failure.
+   Update the number of parsed groups in PN_GIDS on success.
+   Upon any failure return nonzero, and issue diagnostic if SHOW_ERRORS is true.
+   Otherwise return zero.  */
+
+static int
+parse_additional_groups (char const *groups, GETGROUPS_T **pgids,
+                         size_t *pn_gids, bool show_errors)
+{
+  GETGROUPS_T *gids = NULL;
+  size_t n_gids_allocated = 0;
+  size_t n_gids = 0;
+  char *buffer = xstrdup (groups);
+  char const *tmp;
+  int ret = 0;
+
+  for (tmp = strtok (buffer, ","); tmp; tmp = strtok (NULL, ","))
+    {
+      struct group *g;
+      uintmax_t value;
+
+      if (xstrtoumax (tmp, NULL, 10, &value, "") == LONGINT_OK
+          && value <= MAXGID)
+        {
+          while (isspace (to_uchar (*tmp)))
+            tmp++;
+          if (*tmp != '+')
+            {
+              /* Handle the case where the name is numeric.  */
+              g = getgrnam (tmp);
+              if (g != NULL)
+                value = g->gr_gid;
+            }
+          /* Flag that we've got a group from the number.  */
+          g = (struct group *) (intptr_t) ! NULL;
+        }
+      else
+        {
+          g = getgrnam (tmp);
+          if (g != NULL)
+            value = g->gr_gid;
+        }
+
+      if (g == NULL)
+        {
+          ret = -1;
+
+          if (show_errors)
+            {
+              error (0, errno, _("invalid group %s"), quote (tmp));
+              continue;
+            }
+
+          break;
+        }
+
+      if (n_gids == n_gids_allocated)
+        gids = X2NREALLOC (gids, &n_gids_allocated);
+      gids[n_gids++] = value;
+    }
+
+  if (ret == 0 && n_gids == 0)
+    {
+      if (show_errors)
+        error (0, 0, _("invalid group list %s"), quote (groups));
+      ret = -1;
+    }
+
+  *pgids = gids;
+
+  if (ret == 0)
+    *pn_gids = n_gids;
+
+  free (buffer);
+  return ret;
+}
+
+/* Return whether the passed path is equivalent to "/".
+   Note we don't compare against get_root_dev_ino() as "/"
+   could be bind mounted to a separate location.  */
+
+static bool
+is_root (const char* dir)
+{
+  char *resolved = canonicalize_file_name (dir);
+  bool is_res_root = resolved && STREQ ("/", resolved);
+  free (resolved);
+  return is_res_root;
+}
+
+void
+usage (int status)
+{
+  if (status != EXIT_SUCCESS)
+    emit_try_help ();
+  else
+    {
+      printf (_("\
+Usage: %s [OPTION] NEWROOT [COMMAND [ARG]...]\n\
+  or:  %s OPTION\n\
+"), program_name, program_name);
+
+      fputs (_("\
+Run COMMAND with root directory set to NEWROOT.\n\
+\n\
+"), stdout);
+
+      fputs (_("\
+  --groups=G_LIST        specify supplementary groups as g1,g2,..,gN\n\
+"), stdout);
+      fputs (_("\
+  --userspec=USER:GROUP  specify user and group (ID or name) to use\n\
+"), stdout);
+      printf (_("\
+  --skip-chdir           do not change working directory to %s\n\
+"), quoteaf ("/"));
+
+      fputs (HELP_OPTION_DESCRIPTION, stdout);
+      fputs (VERSION_OPTION_DESCRIPTION, stdout);
+      fputs (_("\
+\n\
+If no command is given, run '\"$SHELL\" -i' (default: '/bin/sh -i').\n\
+"), stdout);
+      emit_ancillary_info (PROGRAM_NAME);
+    }
+  exit (status);
+}
+
+int
+main (int argc, char **argv)
+{
+  int c;
+
+  /* Input user and groups spec.  */
+  char *userspec = NULL;
+  char const *username = NULL;
+  char const *groups = NULL;
+  bool skip_chdir = false;
+
+  /* Parsed user and group IDs.  */
+  uid_t uid = -1;
+  gid_t gid = -1;
+  GETGROUPS_T *out_gids = NULL;
+  size_t n_gids = 0;
+
+  initialize_main (&argc, &argv);
+  set_program_name (argv[0]);
+  setlocale (LC_ALL, "");
+  bindtextdomain (PACKAGE, LOCALEDIR);
+  textdomain (PACKAGE);
+
+  initialize_exit_failure (EXIT_CANCELED);
+  atexit (close_stdout);
+
+  while ((c = getopt_long (argc, argv, "+", long_opts, NULL)) != -1)
+    {
+      switch (c)
+        {
+        case USERSPEC:
+          {
+            userspec = optarg;
+            /* Treat 'user:' just like 'user'
+               as we lookup the primary group by default
+               (and support doing so for UIDs as well as names.  */
+            size_t userlen = strlen (userspec);
+            if (userlen && userspec[userlen - 1] == ':')
+              userspec[userlen - 1] = '\0';
+            break;
+          }
+
+        case GROUPS:
+          groups = optarg;
+          break;
+
+        case SKIP_CHDIR:
+          skip_chdir = true;
+          break;
+
+        case_GETOPT_HELP_CHAR;
+
+        case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
+
+        default:
+          usage (EXIT_CANCELED);
+        }
+    }
+
+  if (argc <= optind)
+    {
+      error (0, 0, _("missing operand"));
+      usage (EXIT_CANCELED);
+    }
+
+  char const *newroot = argv[optind];
+  bool is_oldroot = is_root (newroot);
+
+  if (! is_oldroot && skip_chdir)
+    {
+      error (0, 0, _("option --skip-chdir only permitted if NEWROOT is old %s"),
+             quoteaf ("/"));
+      usage (EXIT_CANCELED);
+    }
+
+  if (! is_oldroot)
+    {
+      /* We have to look up users and groups twice.
+        - First, outside the chroot to load potentially necessary passwd/group
+          parsing plugins (e.g. NSS);
+        - Second, inside chroot to redo parsing in case IDs are different.
+          Within chroot lookup is the main justification for having
+          the --user option supported by the chroot command itself.  */
+      if (userspec)
+        ignore_value (parse_user_spec (userspec, &uid, &gid, NULL, NULL));
+
+      /* If no gid is supplied or looked up, do so now.
+        Also lookup the username for use with getgroups.  */
+      if (uid_set (uid) && (! groups || gid_unset (gid)))
+        {
+          const struct passwd *pwd;
+          if ((pwd = getpwuid (uid)))
+            {
+              if (gid_unset (gid))
+                gid = pwd->pw_gid;
+              username = pwd->pw_name;
+            }
+        }
+
+      if (groups && *groups)
+        ignore_value (parse_additional_groups (groups, &out_gids, &n_gids,
+                                               false));
+#if HAVE_SETGROUPS
+      else if (! groups && gid_set (gid) && username)
+        {
+          int ngroups = xgetgroups (username, gid, &out_gids);
+          if (0 < ngroups)
+            n_gids = ngroups;
+        }
+#endif
+    }
+
+  if (chroot (newroot) != 0)
+    die (EXIT_CANCELED, errno, _("cannot change root directory to %s"),
+         quoteaf (newroot));
+
+  if (! skip_chdir && chdir ("/"))
+    die (EXIT_CANCELED, errno, _("cannot chdir to root directory"));
+
+  if (argc == optind + 1)
+    {
+      /* No command.  Run an interactive shell.  */
+      char *shell = getenv ("SHELL");
+      if (shell == NULL)
+        shell = bad_cast ("/bin/sh");
+      argv[0] = shell;
+      argv[1] = bad_cast ("-i");
+      argv[2] = NULL;
+    }
+  else
+    {
+      /* The following arguments give the command.  */
+      argv += optind + 1;
+    }
+
+  /* Attempt to set all three: supplementary groups, group ID, user ID.
+     Diagnose any failures.  If any have failed, exit before execvp.  */
+  if (userspec)
+    {
+      char const *err = parse_user_spec (userspec, &uid, &gid, NULL, NULL);
+
+      if (err && uid_unset (uid) && gid_unset (gid))
+        die (EXIT_CANCELED, errno, "%s", (err));
+    }
+
+  /* If no gid is supplied or looked up, do so now.
+     Also lookup the username for use with getgroups.  */
+  if (uid_set (uid) && (! groups || gid_unset (gid)))
+    {
+      const struct passwd *pwd;
+      if ((pwd = getpwuid (uid)))
+        {
+          if (gid_unset (gid))
+            gid = pwd->pw_gid;
+          username = pwd->pw_name;
+        }
+      else if (gid_unset (gid))
+        {
+          die (EXIT_CANCELED, errno,
+               _("no group specified for unknown uid: %d"), (int) uid);
+        }
+    }
+
+  GETGROUPS_T *gids = out_gids;
+  GETGROUPS_T *in_gids = NULL;
+  if (groups && *groups)
+    {
+      if (parse_additional_groups (groups, &in_gids, &n_gids, !n_gids) != 0)
+        {
+          if (! n_gids)
+            return EXIT_CANCELED;
+          /* else look-up outside the chroot worked, then go with those.  */
+        }
+      else
+        gids = in_gids;
+    }
+#if HAVE_SETGROUPS
+  else if (! groups && gid_set (gid) && username)
+    {
+      int ngroups = xgetgroups (username, gid, &in_gids);
+      if (ngroups <= 0)
+        {
+          if (! n_gids)
+            die (EXIT_CANCELED, errno,
+                 _("failed to get supplemental groups"));
+          /* else look-up outside the chroot worked, then go with those.  */
+        }
+      else
+        {
+          n_gids = ngroups;
+          gids = in_gids;
+        }
+    }
+#endif
+
+  if ((uid_set (uid) || groups) && setgroups (n_gids, gids) != 0)
+    die (EXIT_CANCELED, errno, _("failed to set supplemental groups"));
+
+  free (in_gids);
+  free (out_gids);
+
+  if (gid_set (gid) && setgid (gid))
+    die (EXIT_CANCELED, errno, _("failed to set group-ID"));
+
+  if (uid_set (uid) && setuid (uid))
+    die (EXIT_CANCELED, errno, _("failed to set user-ID"));
+
+  /* Execute the given command.  */
+  execvp (argv[0], argv);
+
+  int exit_status = errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE;
+  error (0, errno, _("failed to run command %s"), quote (argv[0]));
+  return exit_status;
+}