/*
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* linux/fs/binfmt_script.c
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*
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* Copyright (C) 1996 Martin von Löwis
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* original #!-checking implemented by tytso.
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*/
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/stat.h>
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#include <linux/binfmts.h>
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#include <linux/init.h>
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#include <linux/file.h>
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#include <linux/err.h>
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#include <linux/fs.h>
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static int load_script(struct linux_binprm *bprm)
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{
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const char *i_arg, *i_name;
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char *cp;
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struct file *file;
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char interp[BINPRM_BUF_SIZE];
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int retval;
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if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!'))
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return -ENOEXEC;
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/*
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* If the script filename will be inaccessible after exec, typically
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* because it is a "/dev/fd/<fd>/.." path against an O_CLOEXEC fd, give
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* up now (on the assumption that the interpreter will want to load
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* this file).
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*/
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if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE)
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return -ENOENT;
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/*
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* This section does the #! interpretation.
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* Sorta complicated, but hopefully it will work. -TYT
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*/
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allow_write_access(bprm->file);
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fput(bprm->file);
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bprm->file = NULL;
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bprm->buf[BINPRM_BUF_SIZE - 1] = '\0';
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if ((cp = strchr(bprm->buf, '\n')) == NULL)
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cp = bprm->buf+BINPRM_BUF_SIZE-1;
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*cp = '\0';
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while (cp > bprm->buf) {
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cp--;
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if ((*cp == ' ') || (*cp == '\t'))
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*cp = '\0';
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else
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break;
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}
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for (cp = bprm->buf+2; (*cp == ' ') || (*cp == '\t'); cp++);
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if (*cp == '\0')
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return -ENOEXEC; /* No interpreter name found */
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i_name = cp;
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i_arg = NULL;
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for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++)
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/* nothing */ ;
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while ((*cp == ' ') || (*cp == '\t'))
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*cp++ = '\0';
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if (*cp)
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i_arg = cp;
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strcpy (interp, i_name);
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/*
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* OK, we've parsed out the interpreter name and
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* (optional) argument.
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* Splice in (1) the interpreter's name for argv[0]
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* (2) (optional) argument to interpreter
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* (3) filename of shell script (replace argv[0])
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*
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* This is done in reverse order, because of how the
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* user environment and arguments are stored.
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*/
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retval = remove_arg_zero(bprm);
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if (retval)
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return retval;
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retval = copy_strings_kernel(1, &bprm->interp, bprm);
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if (retval < 0) return retval;
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bprm->argc++;
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if (i_arg) {
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retval = copy_strings_kernel(1, &i_arg, bprm);
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if (retval < 0) return retval;
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bprm->argc++;
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}
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retval = copy_strings_kernel(1, &i_name, bprm);
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if (retval) return retval;
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bprm->argc++;
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retval = bprm_change_interp(interp, bprm);
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if (retval < 0)
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return retval;
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/*
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* OK, now restart the process with the interpreter's dentry.
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*/
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file = open_exec(interp);
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if (IS_ERR(file))
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return PTR_ERR(file);
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bprm->file = file;
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retval = prepare_binprm(bprm);
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if (retval < 0)
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return retval;
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return search_binary_handler(bprm);
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}
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static struct linux_binfmt script_format = {
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.module = THIS_MODULE,
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.load_binary = load_script,
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};
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static int __init init_script_binfmt(void)
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{
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register_binfmt(&script_format);
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return 0;
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}
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static void __exit exit_script_binfmt(void)
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{
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unregister_binfmt(&script_format);
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}
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core_initcall(init_script_binfmt);
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module_exit(exit_script_binfmt);
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MODULE_LICENSE("GPL");
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