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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 | /* * 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/slab.h> #include <linux/binfmts.h> #include <linux/init.h> #include <linux/file.h> #include <linux/smp_lock.h> 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; if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!') || (bprm->sh_bang)) 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'; 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 = 0; for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++) /* nothing */ ; while ((*cp == ' ') || (*cp == '\t')) *cp++ = '\0'; 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); 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++; /* * OK, now restart the process with the interpreter's dentry. */ file = open_exec(interp); 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,regs); } struct linux_binfmt script_format = { NULL, THIS_MODULE, load_script, NULL, NULL, 0 }; static int __init init_script_binfmt(void) { return register_binfmt(&script_format); } static void __exit exit_script_binfmt(void) { unregister_binfmt(&script_format); } module_init(init_script_binfmt) module_exit(exit_script_binfmt) |