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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 | /* * 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> static int do_load_script(struct linux_binprm *bprm,struct pt_regs *regs) { char *cp, *i_name, *i_name_start, *i_arg; struct dentry * dentry; char interp[128]; 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++; dput(bprm->dentry); bprm->dentry = NULL; bprm->buf[127] = '\0'; if ((cp = strchr(bprm->buf, '\n')) == NULL) cp = bprm->buf+127; *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_start = i_name = cp; i_arg = 0; for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++) { if (*cp == '/') i_name = cp+1; } while ((*cp == ' ') || (*cp == '\t')) *cp++ = '\0'; if (*cp) i_arg = cp; strcpy (interp, i_name_start); /* * 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); bprm->p = copy_strings(1, &bprm->filename, bprm->page, bprm->p, 2); bprm->argc++; if (i_arg) { bprm->p = copy_strings(1, &i_arg, bprm->page, bprm->p, 2); bprm->argc++; } bprm->p = copy_strings(1, &i_name, bprm->page, bprm->p, 2); bprm->argc++; if (!bprm->p) return -E2BIG; /* * OK, now restart the process with the interpreter's dentry. */ dentry = open_namei(interp, 0, 0); if (IS_ERR(dentry)) return PTR_ERR(dentry); bprm->dentry = dentry; retval = prepare_binprm(bprm); if (retval < 0) return retval; return search_binary_handler(bprm,regs); } static int load_script(struct linux_binprm *bprm,struct pt_regs *regs) { int retval; MOD_INC_USE_COUNT; retval = do_load_script(bprm,regs); MOD_DEC_USE_COUNT; return retval; } struct linux_binfmt script_format = { #ifndef MODULE NULL, 0, load_script, NULL, NULL #else NULL, &__this_module, load_script, NULL, NULL #endif }; __initfunc(int init_script_binfmt(void)) { return register_binfmt(&script_format); } #ifdef MODULE int init_module(void) { return init_script_binfmt(); } void cleanup_module( void) { unregister_binfmt(&script_format); } #endif |