/* * 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/malloc.h> #include <linux/binfmts.h> #include <linux/init.h> #include <linux/file.h> #include <linux/smp_lock.h> 17 static int load_script(struct linux_binprm *bprm,struct pt_regs *regs) { char *cp, *i_name, *i_arg; struct file *file; char interp[BINPRM_BUF_SIZE]; int retval; 24 if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!') || (bprm->sh_bang)) 25 return -ENOEXEC; /* * This section does the #! interpretation. * Sorta complicated, but hopefully it will work. -TYT */ bprm->sh_bang++; allow_write_access(bprm->file); fput(bprm->file); bprm->file = NULL; bprm->buf[BINPRM_BUF_SIZE - 1] = '\0'; 37 if ((cp = strchr(bprm->buf, '\n')) == NULL) cp = bprm->buf+BINPRM_BUF_SIZE-1; *cp = '\0'; 40 while (cp > bprm->buf) { cp--; 42 if ((*cp == ' ') || (*cp == '\t')) *cp = '\0'; 44 else 45 break; } 47 for (cp = bprm->buf+2; (*cp == ' ') || (*cp == '\t'); cp++); 48 if (*cp == '\0') 49 return -ENOEXEC; /* No interpreter name found */ i_name = cp; i_arg = 0; 52 for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++) /* nothing */ ; 54 while ((*cp == ' ') || (*cp == '\t')) *cp++ = '\0'; 56 if (*cp) i_arg = cp; strcpy (interp, i_name); /* * 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. */ remove_arg_zero(bprm); retval = copy_strings_kernel(1, &bprm->filename, bprm); 71 if (retval < 0) return retval; bprm->argc++; 73 if (i_arg) { retval = copy_strings_kernel(1, &i_arg, bprm); 75 if (retval < 0) return retval; bprm->argc++; } retval = copy_strings_kernel(1, &i_name, bprm); 79 if (retval) return retval; bprm->argc++; /* * OK, now restart the process with the interpreter's dentry. */ file = open_exec(interp); 85 if (IS_ERR(file)) 86 return PTR_ERR(file); bprm->file = file; retval = prepare_binprm(bprm); 90 if (retval < 0) 91 return retval; 92 return search_binary_handler(bprm,regs); } struct linux_binfmt script_format = { NULL, THIS_MODULE, load_script, NULL, NULL, 0 }; 99 static int __init init_script_binfmt(void) { 101 return register_binfmt(&script_format); } 104 static void __exit exit_script_binfmt(void) { unregister_binfmt(&script_format); } module_init(init_script_binfmt) module_exit(exit_script_binfmt)