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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 | /* * 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 int load_script(struct linux_binprm *bprm) { const char *i_arg, *i_name; char *cp; struct file *file; int retval; if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!')) return -ENOEXEC; /* * 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; /* * This section does the #! interpretation. * Sorta complicated, but hopefully it will work. -TYT */ allow_write_access(bprm->file); fput(bprm->file); bprm->file = NULL; bprm->buf[BINPRM_BUF_SIZE - 1] = '\0'; if ((cp = strchr(bprm->buf, '\n')) == NULL) cp = bprm->buf+BINPRM_BUF_SIZE-1; *cp = '\0'; while (cp > bprm->buf) { cp--; if ((*cp == ' ') || (*cp == '\t')) *cp = '\0'; else break; } for (cp = bprm->buf+2; (*cp == ' ') || (*cp == '\t'); cp++); if (*cp == '\0') return -ENOEXEC; /* No interpreter name found */ i_name = cp; i_arg = NULL; for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++) /* nothing */ ; while ((*cp == ' ') || (*cp == '\t')) *cp++ = '\0'; if (*cp) i_arg = cp; /* * 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_strings_kernel(1, &bprm->interp, bprm); if (retval < 0) return retval; bprm->argc++; if (i_arg) { retval = copy_strings_kernel(1, &i_arg, bprm); if (retval < 0) return retval; bprm->argc++; } retval = copy_strings_kernel(1, &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->file = file; retval = prepare_binprm(bprm); if (retval < 0) return retval; return search_binary_handler(bprm); } 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_LICENSE("GPL"); |