Example #1
0
static void
chvt(const char *fn)
{
	char dv[20];
	struct stat sb;
	int fd;

	/* for entropy */
	kshstate_f.h = evilhash(fn);

	if (*fn == '-') {
		memcpy(dv, "-/dev/null", sizeof("-/dev/null"));
		fn = dv + 1;
	} else {
		if (stat(fn, &sb)) {
			memcpy(dv, "/dev/ttyC", 9);
			strlcpy(dv + 9, fn, sizeof(dv) - 9);
			if (stat(dv, &sb)) {
				strlcpy(dv + 8, fn, sizeof(dv) - 8);
				if (stat(dv, &sb))
					errorf("chvt: can't find tty %s", fn);
			}
			fn = dv;
		}
		if (!(sb.st_mode & S_IFCHR))
			errorf("chvt: not a char device: %s", fn);
		if ((sb.st_uid != 0) && chown(fn, 0, 0))
			warningf(false, "chvt: cannot chown root %s", fn);
		if (((sb.st_mode & 07777) != 0600) && chmod(fn, (mode_t)0600))
			warningf(false, "chvt: cannot chmod 0600 %s", fn);
#if HAVE_REVOKE
		if (revoke(fn))
#endif
			warningf(false, "chvt: cannot revoke %s, new shell is"
			    " potentially insecure", fn);
	}
	if ((fd = open(fn, O_RDWR)) == -1) {
		sleep(1);
		if ((fd = open(fn, O_RDWR)) == -1)
			errorf("chvt: cannot open %s", fn);
	}
	switch (fork()) {
	case -1:
		errorf("chvt: %s failed", "fork");
	case 0:
		break;
	default:
		exit(0);
	}
	if (setsid() == -1)
		errorf("chvt: %s failed", "setsid");
	if (fn != dv + 1) {
		if (ioctl(fd, TIOCSCTTY, NULL) == -1)
			errorf("chvt: %s failed", "TIOCSCTTY");
		if (tcflush(fd, TCIOFLUSH))
			errorf("chvt: %s failed", "TCIOFLUSH");
	}
	ksh_dup2(fd, 0, false);
	ksh_dup2(fd, 1, false);
	ksh_dup2(fd, 2, false);
	if (fd > 2)
		close(fd);
	chvt_reinit();
}
Example #2
0
static int
main_init(int argc, const char *argv[], Source **sp, struct block **lp)
{
	int argi, i;
	Source *s = NULL;
	struct block *l;
	unsigned char restricted_shell, errexit, utf_flag;
	char *cp;
	const char *ccp, **wp;
	struct tbl *vp;
	struct stat s_stdin;
#if !defined(_PATH_DEFPATH) && defined(_CS_PATH)
	ssize_t k;
#endif

#if defined(MKSH_EBCDIC) || defined(MKSH_FAUX_EBCDIC)
	ebcdic_init();
#endif
	set_ifs(TC_IFSWS);

#ifdef __OS2__
	os2_init(&argc, &argv);
#endif

	/* do things like getpgrp() et al. */
	chvt_reinit();

	/* make sure argv[] is sane, for weird OSes */
	if (!*argv) {
		argv = empty_argv;
		argc = 1;
	}
	kshname = argv[0];

	/* initialise permanent Area */
	ainit(&aperm);
	/* max. name length: -2147483648 = 11 (+ NUL) */
	vtemp = alloc(offsetof(struct tbl, name[0]) + 12, APERM);

	/* set up base environment */
	env.type = E_NONE;
	ainit(&env.area);
	/* set up global l->vars and l->funs */
	newblock();

	/* Do this first so output routines (eg, errorf, shellf) can work */
	initio();

	/* determine the basename (without '-' or path) of the executable */
	ccp = kshname;
	goto begin_parsing_kshname;
	while ((i = ccp[argi++])) {
		if (mksh_cdirsep(i)) {
			ccp += argi;
 begin_parsing_kshname:
			argi = 0;
			if (*ccp == '-')
				++ccp;
		}
	}
	if (!*ccp)
		ccp = empty_argv[0];

	/*
	 * Turn on nohup by default. (AT&T ksh does not have a nohup
	 * option - it always sends the hup).
	 */
	Flag(FNOHUP) = 1;

	/*
	 * Turn on brace expansion by default. AT&T kshs that have
	 * alternation always have it on.
	 */
	Flag(FBRACEEXPAND) = 1;

	/*
	 * Turn on "set -x" inheritance by default.
	 */
	Flag(FXTRACEREC) = 1;

	/* define built-in commands and see if we were called as one */
	ktinit(APERM, &builtins,
	    /* currently up to 54 builtins: 75% of 128 = 2^7 */
	    7);
	for (i = 0; mkshbuiltins[i].name != NULL; i++)
		if (!strcmp(ccp, builtin(mkshbuiltins[i].name,
		    mkshbuiltins[i].func)))
			Flag(FAS_BUILTIN) = 1;

	if (!Flag(FAS_BUILTIN)) {
		/* check for -T option early */
		argi = parse_args(argv, OF_FIRSTTIME, NULL);
		if (argi < 0)
			return (1);

#if defined(MKSH_BINSHPOSIX) || defined(MKSH_BINSHREDUCED)
		/* are we called as -sh or /bin/sh or so? */
		if (!strcmp(ccp, "sh" MKSH_EXE_EXT)) {
			/* either also turns off braceexpand */
#ifdef MKSH_BINSHPOSIX
			/* enable better POSIX conformance */
			change_flag(FPOSIX, OF_FIRSTTIME, true);
#endif
#ifdef MKSH_BINSHREDUCED
			/* enable kludge/compat mode */
			change_flag(FSH, OF_FIRSTTIME, true);
#endif
		}
#endif
	}

	initvar();

	inittraps();

	coproc_init();

	/* set up variable and command dictionaries */
	ktinit(APERM, &taliases, 0);
	ktinit(APERM, &aliases, 0);
#ifndef MKSH_NOPWNAM
	ktinit(APERM, &homedirs, 0);
#endif

	/* define shell keywords */
	initkeywords();

	init_histvec();

	/* initialise tty size before importing environment */
	change_winsz();

#ifdef _PATH_DEFPATH
	def_path = _PATH_DEFPATH;
#else
#ifdef _CS_PATH
	if ((k = confstr(_CS_PATH, NULL, 0)) > 0 &&
	    confstr(_CS_PATH, cp = alloc(k + 1, APERM), k + 1) == k + 1)
		def_path = cp;
	else
#endif
		/*
		 * this is uniform across all OSes unless it
		 * breaks somewhere hard; don't try to optimise,
		 * e.g. add stuff for Interix or remove /usr
		 * for HURD, because e.g. Debian GNU/HURD is
		 * "keeping a regular /usr"; this is supposed
		 * to be a sane 'basic' default PATH
		 */
		def_path = MKSH_UNIXROOT "/bin" MKSH_PATHSEPS
		    MKSH_UNIXROOT "/usr/bin" MKSH_PATHSEPS
		    MKSH_UNIXROOT "/sbin" MKSH_PATHSEPS
		    MKSH_UNIXROOT "/usr/sbin";
#endif

	/*
	 * Set PATH to def_path (will set the path global variable).
	 * (import of environment below will probably change this setting).
	 */
	vp = global(TPATH);
	/* setstr can't fail here */
	setstr(vp, def_path, KSH_RETURN_ERROR);

#ifndef MKSH_NO_CMDLINE_EDITING
	/*
	 * Set edit mode to emacs by default, may be overridden
	 * by the environment or the user. Also, we want tab completion
	 * on in vi by default.
	 */
	change_flag(FEMACS, OF_SPECIAL, true);
#if !MKSH_S_NOVI
	Flag(FVITABCOMPLETE) = 1;
#endif
#endif

	/* import environment */
	init_environ();

	/* override default PATH regardless of environment */
#ifdef MKSH_DEFPATH_OVERRIDE
	vp = global(TPATH);
	setstr(vp, MKSH_DEFPATH_OVERRIDE, KSH_RETURN_ERROR);
#endif

	/* for security */
	typeset(TinitIFS, 0, 0, 0, 0);

	/* assign default shell variable values */
	typeset("PATHSEP=" MKSH_PATHSEPS, 0, 0, 0, 0);
	substitute(initsubs, 0);

	/* Figure out the current working directory and set $PWD */
	vp = global(TPWD);
	cp = str_val(vp);
	/* Try to use existing $PWD if it is valid */
	set_current_wd((mksh_abspath(cp) && test_eval(NULL, TO_FILEQ, cp,
	    Tdot, true)) ? cp : NULL);
	if (current_wd[0])
		simplify_path(current_wd);
	/* Only set pwd if we know where we are or if it had a bogus value */
	if (current_wd[0] || *cp)
		/* setstr can't fail here */
		setstr(vp, current_wd, KSH_RETURN_ERROR);

	for (wp = initcoms; *wp != NULL; wp++) {
		c_builtin(wp);
		while (*wp != NULL)
			wp++;
	}
	setint_n(global("OPTIND"), 1, 10);

	kshuid = getuid();
	kshgid = getgid();
	kshegid = getegid();

	safe_prompt = ksheuid ? "$ " : "# ";
	vp = global("PS1");
	/* Set PS1 if unset or we are root and prompt doesn't contain a # */
	if (!(vp->flag & ISSET) ||
	    (!ksheuid && !strchr(str_val(vp), '#')))
		/* setstr can't fail here */
		setstr(vp, safe_prompt, KSH_RETURN_ERROR);
	setint_n((vp = global("BASHPID")), 0, 10);
	vp->flag |= INT_U;
	setint_n((vp = global("PGRP")), (mksh_uari_t)kshpgrp, 10);
	vp->flag |= INT_U;
	setint_n((vp = global("PPID")), (mksh_uari_t)kshppid, 10);
	vp->flag |= INT_U;
	setint_n((vp = global("USER_ID")), (mksh_uari_t)ksheuid, 10);
	vp->flag |= INT_U;
	setint_n((vp = global("KSHUID")), (mksh_uari_t)kshuid, 10);
	vp->flag |= INT_U;
	setint_n((vp = global("KSHEGID")), (mksh_uari_t)kshegid, 10);
	vp->flag |= INT_U;
	setint_n((vp = global("KSHGID")), (mksh_uari_t)kshgid, 10);
	vp->flag |= INT_U;
	setint_n((vp = global("RANDOM")), rndsetup(), 10);
	vp->flag |= INT_U;
	setint_n((vp_pipest = global("PIPESTATUS")), 0, 10);

	/* Set this before parsing arguments */
	Flag(FPRIVILEGED) = (kshuid != ksheuid || kshgid != kshegid) ? 2 : 0;

	/* this to note if monitor is set on command line (see below) */
#ifndef MKSH_UNEMPLOYED
	Flag(FMONITOR) = 127;
#endif
	/* this to note if utf-8 mode is set on command line (see below) */
	UTFMODE = 2;

	if (!Flag(FAS_BUILTIN)) {
		argi = parse_args(argv, OF_CMDLINE, NULL);
		if (argi < 0)
			return (1);
	}

	/* process this later only, default to off (hysterical raisins) */
	utf_flag = UTFMODE;
	UTFMODE = 0;

	if (Flag(FAS_BUILTIN)) {
		/* auto-detect from environment variables, always */
		utf_flag = 3;
	} else if (Flag(FCOMMAND)) {
		s = pushs(SSTRINGCMDLINE, ATEMP);
		if (!(s->start = s->str = argv[argi++]))
			errorf(Tf_optfoo, "", "", 'c', Treq_arg);
		while (*s->str) {
			if (ctype(*s->str, C_QUOTE))
				break;
			s->str++;
		}
		if (!*s->str)
			s->flags |= SF_MAYEXEC;
		s->str = s->start;
#ifdef MKSH_MIDNIGHTBSD01ASH_COMPAT
		/* compatibility to MidnightBSD 0.1 /bin/sh (kludge) */
		if (Flag(FSH) && argv[argi] && !strcmp(argv[argi], "--"))
			++argi;
#endif
		if (argv[argi])
			kshname = argv[argi++];
	} else if (argi < argc && !Flag(FSTDIN)) {
		s = pushs(SFILE, ATEMP);
#ifdef __OS2__
		/*
		 * A bug in OS/2 extproc (like shebang) handling makes
		 * it not pass the full pathname of a script, so we need
		 * to search for it. This changes the behaviour of a
		 * simple "mksh foo", but can't be helped.
		 */
		s->file = argv[argi++];
		if (search_access(s->file, X_OK) != 0)
			s->file = search_path(s->file, path, X_OK, NULL);
		if (!s->file || !*s->file)
			s->file = argv[argi - 1];
#else
		s->file = argv[argi++];
#endif
		s->u.shf = shf_open(s->file, O_RDONLY, 0,
		    SHF_MAPHI | SHF_CLEXEC);
		if (s->u.shf == NULL) {
			shl_stdout_ok = false;
			warningf(true, Tf_sD_s, s->file, cstrerror(errno));
			/* mandated by SUSv4 */
			exstat = 127;
			unwind(LERROR);
		}
		kshname = s->file;
	} else {
		Flag(FSTDIN) = 1;
		s = pushs(SSTDIN, ATEMP);
		s->file = "<stdin>";
		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
		    NULL);
		if (isatty(0) && isatty(2)) {
			Flag(FTALKING) = Flag(FTALKING_I) = 1;
			/* The following only if isatty(0) */
			s->flags |= SF_TTY;
			s->u.shf->flags |= SHF_INTERRUPT;
			s->file = NULL;
		}
	}

	/* this bizarreness is mandated by POSIX */
	if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
	    Flag(FTALKING))
		reset_nonblock(0);

	/* initialise job control */
	j_init();
	/* do this after j_init() which calls tty_init_state() */
	if (Flag(FTALKING)) {
		if (utf_flag == 2) {
#ifndef MKSH_ASSUME_UTF8
			/* auto-detect from locale or environment */
			utf_flag = 4;
#else /* this may not be an #elif */
#if MKSH_ASSUME_UTF8
			utf_flag = 1;
#else
			/* always disable UTF-8 (for interactive) */
			utf_flag = 0;
#endif
#endif
		}
#ifndef MKSH_NO_CMDLINE_EDITING
		x_init();
#endif
	}

#ifdef SIGWINCH
	sigtraps[SIGWINCH].flags |= TF_SHELL_USES;
	setsig(&sigtraps[SIGWINCH], x_sigwinch,
	    SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
#endif

	l = e->loc;
	if (Flag(FAS_BUILTIN)) {
		l->argc = argc;
		l->argv = argv;
		l->argv[0] = ccp;
	} else {
		l->argc = argc - argi;
		/*
		 * allocate a new array because otherwise, when we modify
		 * it in-place, ps(1) output changes; the meaning of argc
		 * here is slightly different as it excludes kshname, and
		 * we add a trailing NULL sentinel as well
		 */
		l->argv = alloc2(l->argc + 2, sizeof(void *), APERM);
		l->argv[0] = kshname;
		memcpy(&l->argv[1], &argv[argi], l->argc * sizeof(void *));
		l->argv[l->argc + 1] = NULL;
		getopts_reset(1);
	}

	/* divine the initial state of the utf8-mode Flag */
	ccp = null;
	switch (utf_flag) {

	/* auto-detect from locale or environment */
	case 4:
#if HAVE_SETLOCALE_CTYPE
		ccp = setlocale(LC_CTYPE, "");
#if HAVE_LANGINFO_CODESET
		if (!isuc(ccp))
			ccp = nl_langinfo(CODESET);
#endif
		if (!isuc(ccp))
			ccp = null;
#endif
		/* FALLTHROUGH */

	/* auto-detect from environment */
	case 3:
		/* these were imported from environ earlier */
		if (ccp == null)
			ccp = str_val(global("LC_ALL"));
		if (ccp == null)
			ccp = str_val(global("LC_CTYPE"));
		if (ccp == null)
			ccp = str_val(global("LANG"));
		UTFMODE = isuc(ccp);
		break;

	/* not set on command line, not FTALKING */
	case 2:
	/* unknown values */
	default:
		utf_flag = 0;
		/* FALLTHROUGH */

	/* known values */
	case 1:
	case 0:
		UTFMODE = utf_flag;
		break;
	}

	/* Disable during .profile/ENV reading */
	restricted_shell = Flag(FRESTRICTED);
	Flag(FRESTRICTED) = 0;
	errexit = Flag(FERREXIT);
	Flag(FERREXIT) = 0;

	/*
	 * Do this before profile/$ENV so that if it causes problems in them,
	 * user will know why things broke.
	 */
	if (!current_wd[0] && Flag(FTALKING))
		warningf(false, "can't determine current directory");

	if (Flag(FLOGIN))
		include(MKSH_SYSTEM_PROFILE, 0, NULL, true);
	if (!Flag(FPRIVILEGED)) {
		if (Flag(FLOGIN))
			include(substitute("$HOME/.profile", 0), 0, NULL, true);
		if (Flag(FTALKING)) {
			cp = substitute("${ENV:-" MKSHRC_PATH "}", DOTILDE);
			if (cp[0] != '\0')
				include(cp, 0, NULL, true);
		}
	} else {
		include(MKSH_SUID_PROFILE, 0, NULL, true);
		/* turn off -p if not set explicitly */
		if (Flag(FPRIVILEGED) != 1)
			change_flag(FPRIVILEGED, OF_INTERNAL, false);
	}

	if (restricted_shell) {
		c_builtin(restr_com);
		/* After typeset command... */
		Flag(FRESTRICTED) = 1;
	}
	Flag(FERREXIT) = errexit;

	if (Flag(FTALKING) && s)
		hist_init(s);
	else
		/* set after ENV */
		Flag(FTRACKALL) = 1;

	alarm_init();

	*sp = s;
	*lp = l;
	return (0);
}
Example #3
0
static void
chvt(const Getopt *go)
{
	const char *dv = go->optarg;
	char *cp = NULL;
	int fd;

	switch (*dv) {
	case '-':
		dv = "/dev/null";
		break;
	case '!':
		++dv;
		/* FALLTHROUGH */
	default: {
		struct stat sb;

		if (stat(dv, &sb)) {
			cp = shf_smprintf("/dev/ttyC%s", dv);
			dv = cp;
			if (stat(dv, &sb)) {
				memmove(cp + 1, cp, /* /dev/tty */ 8);
				dv = cp + 1;
				if (stat(dv, &sb)) {
					errorf("%s: %s: %s", "chvt",
					    "can't find tty", go->optarg);
				}
			}
		}
		if (!(sb.st_mode & S_IFCHR))
			errorf("%s: %s: %s", "chvt", "not a char device", dv);
#ifndef MKSH_DISABLE_REVOKE_WARNING
#if HAVE_REVOKE
		if (revoke(dv))
#endif
			warningf(false, "%s: %s %s", "chvt",
			    "new shell is potentially insecure, can't revoke",
			    dv);
#endif
	    }
	}
	if ((fd = binopen2(dv, O_RDWR)) < 0) {
		sleep(1);
		if ((fd = binopen2(dv, O_RDWR)) < 0) {
			errorf("%s: %s %s", "chvt", "can't open", dv);
		}
	}
	if (go->optarg[0] != '!') {
		switch (fork()) {
		case -1:
			errorf("%s: %s %s", "chvt", "fork", "failed");
		case 0:
			break;
		default:
			exit(0);
		}
	}
	if (setsid() == -1)
		errorf("%s: %s %s", "chvt", "setsid", "failed");
	if (go->optarg[0] != '-') {
		if (ioctl(fd, TIOCSCTTY, NULL) == -1)
			errorf("%s: %s %s", "chvt", "TIOCSCTTY", "failed");
		if (tcflush(fd, TCIOFLUSH))
			errorf("%s: %s %s", "chvt", "TCIOFLUSH", "failed");
	}
	ksh_dup2(fd, 0, false);
	ksh_dup2(fd, 1, false);
	ksh_dup2(fd, 2, false);
	if (fd > 2)
		close(fd);
	rndset((unsigned long)chvt_rndsetup(go, sizeof(Getopt)));
	chvt_reinit();
}