Ziele Untersuchung
mit Columbo Integrität von
Datenbanken Interaktion und
Portierbarkeit Ergonomie der
Schnittstellen

Angebot Produkte Projekt Beratung

Mittel Analytik Modellierung Sprachen Algebra Logik Hardware Denken Kreativität

Zusammenhänge Gesellschaft Wirtschaft Branche Firma


products/sources/formale Sprachen/C/Linux/fs/ (Open Source Betriebssystem Version 6.17.9^©) Datei vom 24.10.2025 mit Größe 4 kB

Quelle binfmt_script.c Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
*  linux/fs/binfmt_script.c
*
*  Copyright (C) 1996  Martin von Löwis
*  original #!-checking implemented by tytso.
*/

#include <linux/module.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/binfmts.h>
#include <linux/init.h>
#include <linux/file.h>
#include <linux/err.h>
#include <linux/fs.h>

static inline bool spacetab(char c) { return c == ' ' || c == '\t'; }
static inline const char *next_non_spacetab(const char *first, const char *last)
{
for (; first <= last; first++)
  if (!spacetab(*first))
   return first;
return NULL;
}
static inline const char *next_terminator(const char *first, const char *last)
{
for (; first <= last; first++)
  if (spacetab(*first) || !*first)
   return first;
return NULL;
}

static int load_script(struct linux_binprm *bprm)
{
const char *i_name, *i_sep, *i_arg, *i_end, *buf_end;
struct file *file;
int retval;

/* Not ours to exec if we don't start with "#!". */
if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!'))
  return -ENOEXEC;

/*
* This section handles parsing the #! line into separate
* interpreter path and argument strings. We must be careful
* because bprm->buf is not yet guaranteed to be NUL-terminated
* (though the buffer will have trailing NUL padding when the
* file size was smaller than the buffer size).
*
* We do not want to exec a truncated interpreter path, so either
* we find a newline (which indicates nothing is truncated), or
* we find a space/tab/NUL after the interpreter path (which
* itself may be preceded by spaces/tabs). Truncating the
* arguments is fine: the interpreter can re-read the script to
* parse them on its own.
*/
buf_end = bprm->buf + sizeof(bprm->buf) - 1;
i_end = strnchr(bprm->buf, sizeof(bprm->buf), '\n');
if (!i_end) {
  i_end = next_non_spacetab(bprm->buf + 2, buf_end);
  if (!i_end)
   return -ENOEXEC; /* Entire buf is spaces/tabs */
  /*
* If there is no later space/tab/NUL we must assume the
* interpreter path is truncated.
*/
  if (!next_terminator(i_end, buf_end))
   return -ENOEXEC;
  i_end = buf_end;
}
/* Trim any trailing spaces/tabs from i_end */
while (spacetab(i_end[-1]))
  i_end--;

/* Skip over leading spaces/tabs */
i_name = next_non_spacetab(bprm->buf+2, i_end);
if (!i_name || (i_name == i_end))
  return -ENOEXEC; /* No interpreter name found */

/* Is there an optional argument? */
i_arg = NULL;
i_sep = next_terminator(i_name, i_end);
if (i_sep && (*i_sep != '\0'))
  i_arg = next_non_spacetab(i_sep, i_end);

/*
* If the script filename will be inaccessible after exec, typically
* because it is a "/dev/fd/<fd>/.." path against an O_CLOEXEC fd, give
* up now (on the assumption that the interpreter will want to load
* this file).
*/
if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE)
  return -ENOENT;

/*
* OK, we've parsed out the interpreter name and
* (optional) argument.
* Splice in (1) the interpreter's name for argv[0]
*           (2) (optional) argument to interpreter
*           (3) filename of shell script (replace argv[0])
*
* This is done in reverse order, because of how the
* user environment and arguments are stored.
*/
retval = remove_arg_zero(bprm);
if (retval)
  return retval;
retval = copy_string_kernel(bprm->interp, bprm);
if (retval < 0)
  return retval;
bprm->argc++;
*((char *)i_end) = '\0';
if (i_arg) {
  *((char *)i_sep) = '\0';
  retval = copy_string_kernel(i_arg, bprm);
  if (retval < 0)
   return retval;
  bprm->argc++;
}
retval = copy_string_kernel(i_name, bprm);
if (retval)
  return retval;
bprm->argc++;
retval = bprm_change_interp(i_name, bprm);
if (retval < 0)
  return retval;

/*
* OK, now restart the process with the interpreter's dentry.
*/
file = open_exec(i_name);
if (IS_ERR(file))
  return PTR_ERR(file);

bprm->interpreter = file;
return 0;
}

static struct linux_binfmt script_format = {
.module  = THIS_MODULE,
.load_binary = load_script,
};

static int __init init_script_binfmt(void)
{
register_binfmt(&script_format);
return 0;
}

static void __exit exit_script_binfmt(void)
{
unregister_binfmt(&script_format);
}

core_initcall(init_script_binfmt);
module_exit(exit_script_binfmt);
MODULE_DESCRIPTION("Kernel support for scripts starting with #!");
MODULE_LICENSE("GPL");

quality93%

¤ Dauer der Verarbeitung: 0.17 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.