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1 /*	$OpenBSD: main.c,v 1.57 2015/09/10 22:48:58 nicm Exp $	*/
2 /*	$OpenBSD: tty.c,v 1.10 2014/08/10 02:44:26 guenther Exp $	*/
3 /*	$OpenBSD: io.c,v 1.26 2015/09/11 08:00:27 guenther Exp $	*/
4 /*	$OpenBSD: table.c,v 1.16 2015/09/01 13:12:31 tedu Exp $	*/
5 
6 /*-
7  * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
8  *		 2011, 2012, 2013, 2014, 2015
9  *	mirabilos <m@mirbsd.org>
10  *
11  * Provided that these terms and disclaimer and all copyright notices
12  * are retained or reproduced in an accompanying document, permission
13  * is granted to deal in this work without restriction, including un-
14  * limited rights to use, publicly perform, distribute, sell, modify,
15  * merge, give away, or sublicence.
16  *
17  * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
18  * the utmost extent permitted by applicable law, neither express nor
19  * implied; without malicious intent or gross negligence. In no event
20  * may a licensor, author or contributor be held liable for indirect,
21  * direct, other damage, loss, or other issues arising in any way out
22  * of dealing in the work, even if advised of the possibility of such
23  * damage or existence of a defect, except proven that it results out
24  * of said person's immediate fault when using the work as intended.
25  */
26 
27 #define EXTERN
28 #include "sh.h"
29 
30 #if HAVE_LANGINFO_CODESET
31 #include <langinfo.h>
32 #endif
33 #if HAVE_SETLOCALE_CTYPE
34 #include <locale.h>
35 #endif
36 
37 __RCSID("$MirOS: src/bin/mksh/main.c,v 1.306 2015/10/09 21:36:57 tg Exp $");
38 
39 extern char **environ;
40 
41 #ifndef MKSHRC_PATH
42 #define MKSHRC_PATH	"~/.mkshrc"
43 #endif
44 
45 #ifndef MKSH_DEFAULT_TMPDIR
46 #define MKSH_DEFAULT_TMPDIR	MKSH_UNIXROOT "/tmp"
47 #endif
48 
49 static uint8_t isuc(const char *);
50 static int main_init(int, const char *[], Source **, struct block **);
51 void chvt_reinit(void);
52 static void reclaim(void);
53 static void remove_temps(struct temp *);
54 static mksh_uari_t rndsetup(void);
55 #ifdef SIGWINCH
56 static void x_sigwinch(int);
57 #endif
58 
59 static const char initifs[] = "IFS= \t\n";
60 
61 static const char initsubs[] =
62     "${PS2=> } ${PS3=#? } ${PS4=+ } ${SECONDS=0} ${TMOUT=0} ${EPOCHREALTIME=}";
63 
64 static const char *initcoms[] = {
65 	Ttypeset, "-r", initvsn, NULL,
66 	Ttypeset, "-x", "HOME", "PATH", "SHELL", NULL,
67 	Ttypeset, "-i10", "COLUMNS", "LINES", "SECONDS", "TMOUT", NULL,
68 	Talias,
69 	"integer=\\typeset -i",
70 	"local=\\typeset",
71 	/* not "alias -t --": hash -r needs to work */
72 	"hash=\\builtin alias -t",
73 	"type=\\builtin whence -v",
74 	"autoload=\\typeset -fu",
75 	"functions=\\typeset -f",
76 	"history=\\builtin fc -l",
77 	"nameref=\\typeset -n",
78 	"nohup=nohup ",
79 	"r=\\builtin fc -e -",
80 	"login=\\exec login",
81 	NULL,
82 	 /* this is what AT&T ksh seems to track, with the addition of emacs */
83 	Talias, "-tU",
84 	Tcat, "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
85 	"make", "mv", "pr", "rm", "sed", "sh", "vi", "who", NULL,
86 	NULL
87 };
88 
89 static const char *restr_com[] = {
90 	Ttypeset, "-r", "PATH", "ENV", "SHELL", NULL
91 };
92 
93 static bool initio_done;
94 
95 /* top-level parsing and execution environment */
96 static struct env env;
97 struct env *e = &env;
98 
99 static mksh_uari_t
rndsetup(void)100 rndsetup(void)
101 {
102 	register uint32_t h;
103 	struct {
104 		ALLOC_ITEM alloc_INT;
105 		void *dataptr, *stkptr, *mallocptr;
106 #if defined(__GLIBC__) && (__GLIBC__ >= 2)
107 		sigjmp_buf jbuf;
108 #endif
109 		struct timeval tv;
110 	} *bufptr;
111 	char *cp;
112 
113 	cp = alloc(sizeof(*bufptr) - ALLOC_SIZE, APERM);
114 #ifdef DEBUG
115 	/* clear the allocated space, for valgrind */
116 	memset(cp, 0, sizeof(*bufptr) - ALLOC_SIZE);
117 #endif
118 	/* undo what alloc() did to the malloc result address */
119 	bufptr = (void *)(cp - ALLOC_SIZE);
120 	/* PIE or something similar provides us with deltas here */
121 	bufptr->dataptr = &rndsetupstate;
122 	/* ASLR in at least Windows, Linux, some BSDs */
123 	bufptr->stkptr = &bufptr;
124 	/* randomised malloc in BSD (and possibly others) */
125 	bufptr->mallocptr = bufptr;
126 #if defined(__GLIBC__) && (__GLIBC__ >= 2)
127 	/* glibc pointer guard */
128 	sigsetjmp(bufptr->jbuf, 1);
129 #endif
130 	/* introduce variation (and yes, second arg MBZ for portability) */
131 	mksh_TIME(bufptr->tv);
132 
133 	h = chvt_rndsetup(bufptr, sizeof(*bufptr));
134 
135 	afree(cp, APERM);
136 	return ((mksh_uari_t)h);
137 }
138 
139 void
chvt_reinit(void)140 chvt_reinit(void)
141 {
142 	kshpid = procpid = getpid();
143 	ksheuid = geteuid();
144 	kshpgrp = getpgrp();
145 	kshppid = getppid();
146 }
147 
148 static const char *empty_argv[] = {
149 	"mksh", NULL
150 };
151 
152 static uint8_t
isuc(const char * cx)153 isuc(const char *cx) {
154 	char *cp, *x;
155 	uint8_t rv = 0;
156 
157 	if (!cx || !*cx)
158 		return (0);
159 
160 	/* uppercase a string duplicate */
161 	strdupx(x, cx, ATEMP);
162 	cp = x;
163 	while ((*cp = ksh_toupper(*cp)))
164 		++cp;
165 
166 	/* check for UTF-8 */
167 	if (strstr(x, "UTF-8") || strstr(x, "UTF8"))
168 		rv = 1;
169 
170 	/* free copy and out */
171 	afree(x, ATEMP);
172 	return (rv);
173 }
174 
175 static int
main_init(int argc,const char * argv[],Source ** sp,struct block ** lp)176 main_init(int argc, const char *argv[], Source **sp, struct block **lp)
177 {
178 	int argi, i;
179 	Source *s = NULL;
180 	struct block *l;
181 	unsigned char restricted_shell, errexit, utf_flag;
182 	char *cp;
183 	const char *ccp, **wp;
184 	struct tbl *vp;
185 	struct stat s_stdin;
186 #if !defined(_PATH_DEFPATH) && defined(_CS_PATH)
187 	ssize_t k;
188 #endif
189 
190 #ifdef __OS2__
191 	for (i = 0; i < 3; ++i)
192 		if (!isatty(i))
193 			setmode(i, O_BINARY);
194 #endif
195 
196 	/* do things like getpgrp() et al. */
197 	chvt_reinit();
198 
199 	/* make sure argv[] is sane, for weird OSes */
200 	if (!*argv) {
201 		argv = empty_argv;
202 		argc = 1;
203 	}
204 	kshname = argv[0];
205 
206 	/* initialise permanent Area */
207 	ainit(&aperm);
208 
209 	/* set up base environment */
210 	env.type = E_NONE;
211 	ainit(&env.area);
212 	/* set up global l->vars and l->funs */
213 	newblock();
214 
215 	/* Do this first so output routines (eg, errorf, shellf) can work */
216 	initio();
217 
218 	/* determine the basename (without '-' or path) of the executable */
219 	ccp = kshname;
220 	goto begin_parse_kshname;
221 	while ((i = ccp[argi++])) {
222 		if (i == '/') {
223 			ccp += argi;
224  begin_parse_kshname:
225 			argi = 0;
226 			if (*ccp == '-')
227 				++ccp;
228 		}
229 	}
230 	if (!*ccp)
231 		ccp = empty_argv[0];
232 
233 	/*
234 	 * Turn on nohup by default. (AT&T ksh does not have a nohup
235 	 * option - it always sends the hup).
236 	 */
237 	Flag(FNOHUP) = 1;
238 
239 	/*
240 	 * Turn on brace expansion by default. AT&T kshs that have
241 	 * alternation always have it on.
242 	 */
243 	Flag(FBRACEEXPAND) = 1;
244 
245 	/*
246 	 * Turn on "set -x" inheritance by default.
247 	 */
248 	Flag(FXTRACEREC) = 1;
249 
250 	/* define built-in commands and see if we were called as one */
251 	ktinit(APERM, &builtins,
252 	    /* currently up to 54 builtins: 75% of 128 = 2^7 */
253 	    7);
254 	for (i = 0; mkshbuiltins[i].name != NULL; i++)
255 		if (!strcmp(ccp, builtin(mkshbuiltins[i].name,
256 		    mkshbuiltins[i].func)))
257 			Flag(FAS_BUILTIN) = 1;
258 
259 	if (!Flag(FAS_BUILTIN)) {
260 		/* check for -T option early */
261 		argi = parse_args(argv, OF_FIRSTTIME, NULL);
262 		if (argi < 0)
263 			return (1);
264 
265 #if defined(MKSH_BINSHPOSIX) || defined(MKSH_BINSHREDUCED)
266 		/* are we called as -sh or /bin/sh or so? */
267 		if (!strcmp(ccp, "sh" MKSH_EXE_EXT)) {
268 			/* either also turns off braceexpand */
269 #ifdef MKSH_BINSHPOSIX
270 			/* enable better POSIX conformance */
271 			change_flag(FPOSIX, OF_FIRSTTIME, true);
272 #endif
273 #ifdef MKSH_BINSHREDUCED
274 			/* enable kludge/compat mode */
275 			change_flag(FSH, OF_FIRSTTIME, true);
276 #endif
277 		}
278 #endif
279 	}
280 
281 	initvar();
282 
283 	initctypes();
284 
285 	inittraps();
286 
287 	coproc_init();
288 
289 	/* set up variable and command dictionaries */
290 	ktinit(APERM, &taliases, 0);
291 	ktinit(APERM, &aliases, 0);
292 #ifndef MKSH_NOPWNAM
293 	ktinit(APERM, &homedirs, 0);
294 #endif
295 
296 	/* define shell keywords */
297 	initkeywords();
298 
299 	init_histvec();
300 
301 	/* initialise tty size before importing environment */
302 	change_winsz();
303 
304 #ifdef _PATH_DEFPATH
305 	def_path = _PATH_DEFPATH;
306 #else
307 #ifdef _CS_PATH
308 	if ((k = confstr(_CS_PATH, NULL, 0)) > 0 &&
309 	    confstr(_CS_PATH, cp = alloc(k + 1, APERM), k + 1) == k + 1)
310 		def_path = cp;
311 	else
312 #endif
313 		/*
314 		 * this is uniform across all OSes unless it
315 		 * breaks somewhere; don't try to optimise,
316 		 * e.g. add stuff for Interix or remove /usr
317 		 * for HURD, because e.g. Debian GNU/HURD is
318 		 * "keeping a regular /usr"; this is supposed
319 		 * to be a sane 'basic' default PATH
320 		 */
321 		def_path = MKSH_UNIXROOT "/bin" MKSH_PATHSEPS
322 		    MKSH_UNIXROOT "/usr/bin" MKSH_PATHSEPS
323 		    MKSH_UNIXROOT "/sbin" MKSH_PATHSEPS
324 		    MKSH_UNIXROOT "/usr/sbin";
325 #endif
326 
327 	/*
328 	 * Set PATH to def_path (will set the path global variable).
329 	 * (import of environment below will probably change this setting).
330 	 */
331 	vp = global("PATH");
332 	/* setstr can't fail here */
333 	setstr(vp, def_path, KSH_RETURN_ERROR);
334 
335 #ifndef MKSH_NO_CMDLINE_EDITING
336 	/*
337 	 * Set edit mode to emacs by default, may be overridden
338 	 * by the environment or the user. Also, we want tab completion
339 	 * on in vi by default.
340 	 */
341 	change_flag(FEMACS, OF_SPECIAL, true);
342 #if !MKSH_S_NOVI
343 	Flag(FVITABCOMPLETE) = 1;
344 #endif
345 #endif
346 
347 	/* import environment */
348 	if (environ != NULL) {
349 		wp = (const char **)environ;
350 		while (*wp != NULL) {
351 			rndpush(*wp);
352 			typeset(*wp, IMPORT | EXPORT, 0, 0, 0);
353 			++wp;
354 		}
355 	}
356 
357 	/* for security */
358 	typeset(initifs, 0, 0, 0, 0);
359 
360 	/* assign default shell variable values */
361 	substitute(initsubs, 0);
362 
363 	/* Figure out the current working directory and set $PWD */
364 	vp = global("PWD");
365 	cp = str_val(vp);
366 	/* Try to use existing $PWD if it is valid */
367 	set_current_wd((mksh_abspath(cp) && test_eval(NULL, TO_FILEQ, cp, ".",
368 	    true)) ? cp : NULL);
369 	if (current_wd[0])
370 		simplify_path(current_wd);
371 	/* Only set pwd if we know where we are or if it had a bogus value */
372 	if (current_wd[0] || *cp)
373 		/* setstr can't fail here */
374 		setstr(vp, current_wd, KSH_RETURN_ERROR);
375 
376 	for (wp = initcoms; *wp != NULL; wp++) {
377 		shcomexec(wp);
378 		while (*wp != NULL)
379 			wp++;
380 	}
381 	setint_n(global("OPTIND"), 1, 10);
382 
383 	kshuid = getuid();
384 	kshgid = getgid();
385 	kshegid = getegid();
386 
387 	safe_prompt = ksheuid ? "$ " : "# ";
388 	vp = global("PS1");
389 	/* Set PS1 if unset or we are root and prompt doesn't contain a # */
390 	if (!(vp->flag & ISSET) ||
391 	    (!ksheuid && !strchr(str_val(vp), '#')))
392 		/* setstr can't fail here */
393 		setstr(vp, safe_prompt, KSH_RETURN_ERROR);
394 	setint_n((vp = global("BASHPID")), 0, 10);
395 	vp->flag |= INT_U;
396 	setint_n((vp = global("PGRP")), (mksh_uari_t)kshpgrp, 10);
397 	vp->flag |= INT_U;
398 	setint_n((vp = global("PPID")), (mksh_uari_t)kshppid, 10);
399 	vp->flag |= INT_U;
400 	setint_n((vp = global("USER_ID")), (mksh_uari_t)ksheuid, 10);
401 	vp->flag |= INT_U;
402 	setint_n((vp = global("KSHUID")), (mksh_uari_t)kshuid, 10);
403 	vp->flag |= INT_U;
404 	setint_n((vp = global("KSHEGID")), (mksh_uari_t)kshegid, 10);
405 	vp->flag |= INT_U;
406 	setint_n((vp = global("KSHGID")), (mksh_uari_t)kshgid, 10);
407 	vp->flag |= INT_U;
408 	setint_n((vp = global("RANDOM")), rndsetup(), 10);
409 	vp->flag |= INT_U;
410 	setint_n((vp_pipest = global("PIPESTATUS")), 0, 10);
411 
412 	/* Set this before parsing arguments */
413 	Flag(FPRIVILEGED) = (kshuid != ksheuid || kshgid != kshegid) ? 2 : 0;
414 
415 	/* this to note if monitor is set on command line (see below) */
416 #ifndef MKSH_UNEMPLOYED
417 	Flag(FMONITOR) = 127;
418 #endif
419 	/* this to note if utf-8 mode is set on command line (see below) */
420 	UTFMODE = 2;
421 
422 	if (!Flag(FAS_BUILTIN)) {
423 		argi = parse_args(argv, OF_CMDLINE, NULL);
424 		if (argi < 0)
425 			return (1);
426 	}
427 
428 	/* process this later only, default to off (hysterical raisins) */
429 	utf_flag = UTFMODE;
430 	UTFMODE = 0;
431 
432 	if (Flag(FAS_BUILTIN)) {
433 		/* auto-detect from environment variables, always */
434 		utf_flag = 3;
435 	} else if (Flag(FCOMMAND)) {
436 		s = pushs(SSTRINGCMDLINE, ATEMP);
437 		if (!(s->start = s->str = argv[argi++]))
438 			errorf("%s %s", "-c", "requires an argument");
439 		while (*s->str) {
440 			if (*s->str != ' ' && ctype(*s->str, C_QUOTE))
441 				break;
442 			s->str++;
443 		}
444 		if (!*s->str)
445 			s->flags |= SF_MAYEXEC;
446 		s->str = s->start;
447 #ifdef MKSH_MIDNIGHTBSD01ASH_COMPAT
448 		/* compatibility to MidnightBSD 0.1 /bin/sh (kludge) */
449 		if (Flag(FSH) && argv[argi] && !strcmp(argv[argi], "--"))
450 			++argi;
451 #endif
452 		if (argv[argi])
453 			kshname = argv[argi++];
454 	} else if (argi < argc && !Flag(FSTDIN)) {
455 		s = pushs(SFILE, ATEMP);
456 #ifdef __OS2__
457 		/*
458 		 * A bug in OS/2 extproc (like shebang) handling makes
459 		 * it not pass the full pathname of a script, so we need
460 		 * to search for it. This changes the behaviour of a
461 		 * simple "mksh foo", but can't be helped.
462 		 */
463 		s->file = search_path(argv[argi++], path, X_OK, NULL);
464 		if (!s->file || !*s->file)
465 			s->file = argv[argi - 1];
466 #else
467 		s->file = argv[argi++];
468 #endif
469 		s->u.shf = shf_open(s->file, O_RDONLY, 0,
470 		    SHF_MAPHI | SHF_CLEXEC);
471 		if (s->u.shf == NULL) {
472 			shl_stdout_ok = false;
473 			warningf(true, "%s: %s", s->file, cstrerror(errno));
474 			/* mandated by SUSv4 */
475 			exstat = 127;
476 			unwind(LERROR);
477 		}
478 		kshname = s->file;
479 	} else {
480 		Flag(FSTDIN) = 1;
481 		s = pushs(SSTDIN, ATEMP);
482 		s->file = "<stdin>";
483 		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
484 		    NULL);
485 		if (isatty(0) && isatty(2)) {
486 			Flag(FTALKING) = Flag(FTALKING_I) = 1;
487 			/* The following only if isatty(0) */
488 			s->flags |= SF_TTY;
489 			s->u.shf->flags |= SHF_INTERRUPT;
490 			s->file = NULL;
491 		}
492 	}
493 
494 	/* this bizarreness is mandated by POSIX */
495 	if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
496 	    Flag(FTALKING))
497 		reset_nonblock(0);
498 
499 	/* initialise job control */
500 	j_init();
501 	/* do this after j_init() which calls tty_init_state() */
502 	if (Flag(FTALKING)) {
503 		if (utf_flag == 2) {
504 #ifndef MKSH_ASSUME_UTF8
505 			/* auto-detect from locale or environment */
506 			utf_flag = 4;
507 #else /* this may not be an #elif */
508 #if MKSH_ASSUME_UTF8
509 			utf_flag = 1;
510 #else
511 			/* always disable UTF-8 (for interactive) */
512 			utf_flag = 0;
513 #endif
514 #endif
515 		}
516 #ifndef MKSH_NO_CMDLINE_EDITING
517 		x_init();
518 #endif
519 	}
520 
521 #ifdef SIGWINCH
522 	sigtraps[SIGWINCH].flags |= TF_SHELL_USES;
523 	setsig(&sigtraps[SIGWINCH], x_sigwinch,
524 	    SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
525 #endif
526 
527 	l = e->loc;
528 	if (Flag(FAS_BUILTIN)) {
529 		l->argc = argc;
530 		l->argv = argv;
531 		l->argv[0] = ccp;
532 	} else {
533 		l->argc = argc - argi;
534 		/*
535 		 * allocate a new array because otherwise, when we modify
536 		 * it in-place, ps(1) output changes; the meaning of argc
537 		 * here is slightly different as it excludes kshname, and
538 		 * we add a trailing NULL sentinel as well
539 		 */
540 		l->argv = alloc2(l->argc + 2, sizeof(void *), APERM);
541 		l->argv[0] = kshname;
542 		memcpy(&l->argv[1], &argv[argi], l->argc * sizeof(void *));
543 		l->argv[l->argc + 1] = NULL;
544 		getopts_reset(1);
545 	}
546 
547 	/* divine the initial state of the utf8-mode Flag */
548 	ccp = null;
549 	switch (utf_flag) {
550 
551 	/* auto-detect from locale or environment */
552 	case 4:
553 #if HAVE_SETLOCALE_CTYPE
554 		ccp = setlocale(LC_CTYPE, "");
555 #if HAVE_LANGINFO_CODESET
556 		if (!isuc(ccp))
557 			ccp = nl_langinfo(CODESET);
558 #endif
559 		if (!isuc(ccp))
560 			ccp = null;
561 		/* FALLTHROUGH */
562 #endif
563 
564 	/* auto-detect from environment */
565 	case 3:
566 		/* these were imported from environ earlier */
567 		if (ccp == null)
568 			ccp = str_val(global("LC_ALL"));
569 		if (ccp == null)
570 			ccp = str_val(global("LC_CTYPE"));
571 		if (ccp == null)
572 			ccp = str_val(global("LANG"));
573 		UTFMODE = isuc(ccp);
574 		break;
575 
576 	/* not set on command line, not FTALKING */
577 	case 2:
578 	/* unknown values */
579 	default:
580 		utf_flag = 0;
581 		/* FALLTHROUGH */
582 
583 	/* known values */
584 	case 1:
585 	case 0:
586 		UTFMODE = utf_flag;
587 		break;
588 	}
589 
590 	/* Disable during .profile/ENV reading */
591 	restricted_shell = Flag(FRESTRICTED);
592 	Flag(FRESTRICTED) = 0;
593 	errexit = Flag(FERREXIT);
594 	Flag(FERREXIT) = 0;
595 
596 	/*
597 	 * Do this before profile/$ENV so that if it causes problems in them,
598 	 * user will know why things broke.
599 	 */
600 	if (!current_wd[0] && Flag(FTALKING))
601 		warningf(false, "can't determine current directory");
602 
603 	if (Flag(FLOGIN))
604 		include(MKSH_SYSTEM_PROFILE, 0, NULL, true);
605 	if (!Flag(FPRIVILEGED)) {
606 		if (Flag(FLOGIN))
607 			include(substitute("$HOME/.profile", 0), 0, NULL, true);
608 		if (Flag(FTALKING)) {
609 			cp = substitute(substitute("${ENV:-" MKSHRC_PATH "}",
610 			    0), DOTILDE);
611 			if (cp[0] != '\0')
612 				include(cp, 0, NULL, true);
613 		}
614 	} else {
615 		include(MKSH_SUID_PROFILE, 0, NULL, true);
616 		/* turn off -p if not set explicitly */
617 		if (Flag(FPRIVILEGED) != 1)
618 			change_flag(FPRIVILEGED, OF_INTERNAL, false);
619 	}
620 
621 	if (restricted_shell) {
622 		shcomexec(restr_com);
623 		/* After typeset command... */
624 		Flag(FRESTRICTED) = 1;
625 	}
626 	Flag(FERREXIT) = errexit;
627 
628 	if (Flag(FTALKING) && s)
629 		hist_init(s);
630 	else
631 		/* set after ENV */
632 		Flag(FTRACKALL) = 1;
633 
634 	alarm_init();
635 
636 	*sp = s;
637 	*lp = l;
638 	return (0);
639 }
640 
641 /* this indirection barrier reduces stack usage during normal operation */
642 
643 int
main(int argc,const char * argv[])644 main(int argc, const char *argv[])
645 {
646 	int rv;
647 	Source *s;
648 	struct block *l;
649 
650 	if ((rv = main_init(argc, argv, &s, &l)) == 0) {
651 		if (Flag(FAS_BUILTIN)) {
652 			rv = shcomexec(l->argv);
653 		} else {
654 			shell(s, true);
655 			/* NOTREACHED */
656 		}
657 	}
658 	return (rv);
659 }
660 
661 int
include(const char * name,int argc,const char ** argv,bool intr_ok)662 include(const char *name, int argc, const char **argv, bool intr_ok)
663 {
664 	Source *volatile s = NULL;
665 	struct shf *shf;
666 	const char **volatile old_argv;
667 	volatile int old_argc;
668 	int i;
669 
670 	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI | SHF_CLEXEC);
671 	if (shf == NULL)
672 		return (-1);
673 
674 	if (argv) {
675 		old_argv = e->loc->argv;
676 		old_argc = e->loc->argc;
677 	} else {
678 		old_argv = NULL;
679 		old_argc = 0;
680 	}
681 	newenv(E_INCL);
682 	if ((i = kshsetjmp(e->jbuf))) {
683 		quitenv(s ? s->u.shf : NULL);
684 		if (old_argv) {
685 			e->loc->argv = old_argv;
686 			e->loc->argc = old_argc;
687 		}
688 		switch (i) {
689 		case LRETURN:
690 		case LERROR:
691 			/* see below */
692 			return (exstat & 0xFF);
693 		case LINTR:
694 			/*
695 			 * intr_ok is set if we are including .profile or $ENV.
696 			 * If user ^Cs out, we don't want to kill the shell...
697 			 */
698 			if (intr_ok && ((exstat & 0xFF) - 128) != SIGTERM)
699 				return (1);
700 			/* FALLTHROUGH */
701 		case LEXIT:
702 		case LLEAVE:
703 		case LSHELL:
704 			unwind(i);
705 			/* NOTREACHED */
706 		default:
707 			internal_errorf("%s %d", "include", i);
708 			/* NOTREACHED */
709 		}
710 	}
711 	if (argv) {
712 		e->loc->argv = argv;
713 		e->loc->argc = argc;
714 	}
715 	s = pushs(SFILE, ATEMP);
716 	s->u.shf = shf;
717 	strdupx(s->file, name, ATEMP);
718 	i = shell(s, false);
719 	quitenv(s->u.shf);
720 	if (old_argv) {
721 		e->loc->argv = old_argv;
722 		e->loc->argc = old_argc;
723 	}
724 	/* & 0xff to ensure value not -1 */
725 	return (i & 0xFF);
726 }
727 
728 /* spawn a command into a shell optionally keeping track of the line number */
729 int
command(const char * comm,int line)730 command(const char *comm, int line)
731 {
732 	Source *s;
733 
734 	s = pushs(SSTRING, ATEMP);
735 	s->start = s->str = comm;
736 	s->line = line;
737 	return (shell(s, false));
738 }
739 
740 /*
741  * run the commands from the input source, returning status.
742  */
743 int
shell(Source * volatile s,volatile bool toplevel)744 shell(Source * volatile s, volatile bool toplevel)
745 {
746 	struct op *t;
747 	volatile bool wastty = tobool(s->flags & SF_TTY);
748 	volatile uint8_t attempts = 13;
749 	volatile bool interactive = Flag(FTALKING) && toplevel;
750 	volatile bool sfirst = true;
751 	Source *volatile old_source = source;
752 	int i;
753 
754 	newenv(E_PARSE);
755 	if (interactive)
756 		really_exit = false;
757 	switch ((i = kshsetjmp(e->jbuf))) {
758 	case 0:
759 		break;
760 	case LINTR:
761 		/* we get here if SIGINT not caught or ignored */
762 	case LERROR:
763 	case LSHELL:
764 		if (interactive) {
765 			if (i == LINTR)
766 				shellf("\n");
767 			/*
768 			 * Reset any eof that was read as part of a
769 			 * multiline command.
770 			 */
771 			if (Flag(FIGNOREEOF) && s->type == SEOF && wastty)
772 				s->type = SSTDIN;
773 			/*
774 			 * Used by exit command to get back to
775 			 * top level shell. Kind of strange since
776 			 * interactive is set if we are reading from
777 			 * a tty, but to have stopped jobs, one only
778 			 * needs FMONITOR set (not FTALKING/SF_TTY)...
779 			 */
780 			/* toss any input we have so far */
781 			yyrecursive_pop(true);
782 			s->start = s->str = null;
783 			retrace_info = NULL;
784 			herep = heres;
785 			break;
786 		}
787 		/* FALLTHROUGH */
788 	case LEXIT:
789 	case LLEAVE:
790 	case LRETURN:
791 		source = old_source;
792 		quitenv(NULL);
793 		/* keep on going */
794 		unwind(i);
795 		/* NOTREACHED */
796 	default:
797 		source = old_source;
798 		quitenv(NULL);
799 		internal_errorf("%s %d", "shell", i);
800 		/* NOTREACHED */
801 	}
802 	while (/* CONSTCOND */ 1) {
803 		if (trap)
804 			runtraps(0);
805 
806 		if (s->next == NULL) {
807 			if (Flag(FVERBOSE))
808 				s->flags |= SF_ECHO;
809 			else
810 				s->flags &= ~SF_ECHO;
811 		}
812 		if (interactive) {
813 			j_notify();
814 			set_prompt(PS1, s);
815 		}
816 		t = compile(s, sfirst);
817 		if (interactive)
818 			histsave(&s->line, NULL, HIST_FLUSH, true);
819 		sfirst = false;
820 		if (!t)
821 			goto source_no_tree;
822 		if (t->type == TEOF) {
823 			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
824 				shellf("Use 'exit' to leave mksh\n");
825 				s->type = SSTDIN;
826 			} else if (wastty && !really_exit &&
827 			    j_stopped_running()) {
828 				really_exit = true;
829 				s->type = SSTDIN;
830 			} else {
831 				/*
832 				 * this for POSIX which says EXIT traps
833 				 * shall be taken in the environment
834 				 * immediately after the last command
835 				 * executed.
836 				 */
837 				if (toplevel)
838 					unwind(LEXIT);
839 				break;
840 			}
841 		} else if ((s->flags & SF_MAYEXEC) && t->type == TCOM)
842 			t->u.evalflags |= DOTCOMEXEC;
843 		if (!Flag(FNOEXEC) || (s->flags & SF_TTY))
844 			exstat = execute(t, 0, NULL) & 0xFF;
845 
846 		if (t->type != TEOF && interactive && really_exit)
847 			really_exit = false;
848 
849  source_no_tree:
850 		reclaim();
851 	}
852 	quitenv(NULL);
853 	source = old_source;
854 	return (exstat & 0xFF);
855 }
856 
857 /* return to closest error handler or shell(), exit if none found */
858 /* note: i MUST NOT be 0 */
859 void
unwind(int i)860 unwind(int i)
861 {
862 	/*
863 	 * This is a kludge. We need to restore everything that was
864 	 * changed in the new environment, see cid 1005090337C7A669439
865 	 * and 10050903386452ACBF1, but fail to even save things most of
866 	 * the time. funcs.c:c_eval() changes FERREXIT temporarily to 0,
867 	 * which needs to be restored thus (related to Debian #696823).
868 	 * We did not save the shell flags, so we use a special or'd
869 	 * value here... this is mostly to clean up behind *other*
870 	 * callers of unwind(LERROR) here; exec.c has the regular case.
871 	 */
872 	if (Flag(FERREXIT) & 0x80) {
873 		/* GNU bash does not run this trapsig */
874 		trapsig(ksh_SIGERR);
875 		Flag(FERREXIT) &= ~0x80;
876 	}
877 
878 	/* ordering for EXIT vs ERR is a bit odd (this is what AT&T ksh does) */
879 	if (i == LEXIT || ((i == LERROR || i == LINTR) &&
880 	    sigtraps[ksh_SIGEXIT].trap &&
881 	    (!Flag(FTALKING) || Flag(FERREXIT)))) {
882 		++trap_nested;
883 		runtrap(&sigtraps[ksh_SIGEXIT], trap_nested == 1);
884 		--trap_nested;
885 		i = LLEAVE;
886 	} else if (Flag(FERREXIT) == 1 && (i == LERROR || i == LINTR)) {
887 		++trap_nested;
888 		runtrap(&sigtraps[ksh_SIGERR], trap_nested == 1);
889 		--trap_nested;
890 		i = LLEAVE;
891 	}
892 
893 	while (/* CONSTCOND */ 1) {
894 		switch (e->type) {
895 		case E_PARSE:
896 		case E_FUNC:
897 		case E_INCL:
898 		case E_LOOP:
899 		case E_ERRH:
900 			kshlongjmp(e->jbuf, i);
901 			/* NOTREACHED */
902 		case E_NONE:
903 			if (i == LINTR)
904 				e->flags |= EF_FAKE_SIGDIE;
905 			/* FALLTHROUGH */
906 		default:
907 			quitenv(NULL);
908 			/*
909 			 * quitenv() may have reclaimed the memory
910 			 * used by source which will end badly when
911 			 * we jump to a function that expects it to
912 			 * be valid
913 			 */
914 			source = NULL;
915 		}
916 	}
917 }
918 
919 void
newenv(int type)920 newenv(int type)
921 {
922 	struct env *ep;
923 	char *cp;
924 
925 	/*
926 	 * struct env includes ALLOC_ITEM for alignment constraints
927 	 * so first get the actually used memory, then assign it
928 	 */
929 	cp = alloc(sizeof(struct env) - ALLOC_SIZE, ATEMP);
930 	/* undo what alloc() did to the malloc result address */
931 	ep = (void *)(cp - ALLOC_SIZE);
932 	/* initialise public members of struct env (not the ALLOC_ITEM) */
933 	ainit(&ep->area);
934 	ep->oenv = e;
935 	ep->loc = e->loc;
936 	ep->savefd = NULL;
937 	ep->temps = NULL;
938 	ep->yyrecursive_statep = NULL;
939 	ep->type = type;
940 	ep->flags = 0;
941 	/* jump buffer is invalid because flags == 0 */
942 	e = ep;
943 }
944 
945 void
quitenv(struct shf * shf)946 quitenv(struct shf *shf)
947 {
948 	struct env *ep = e;
949 	char *cp;
950 	int fd;
951 
952 	yyrecursive_pop(true);
953 	while (ep->oenv && ep->oenv->loc != ep->loc)
954 		popblock();
955 	if (ep->savefd != NULL) {
956 		for (fd = 0; fd < NUFILE; fd++)
957 			/* if ep->savefd[fd] < 0, means fd was closed */
958 			if (ep->savefd[fd])
959 				restfd(fd, ep->savefd[fd]);
960 		if (ep->savefd[2])
961 			/* Clear any write errors */
962 			shf_reopen(2, SHF_WR, shl_out);
963 	}
964 	/*
965 	 * Bottom of the stack.
966 	 * Either main shell is exiting or cleanup_parents_env() was called.
967 	 */
968 	if (ep->oenv == NULL) {
969 #ifdef DEBUG_LEAKS
970 		int i;
971 #endif
972 
973 		if (ep->type == E_NONE) {
974 			/* Main shell exiting? */
975 #if HAVE_PERSISTENT_HISTORY
976 			if (Flag(FTALKING))
977 				hist_finish();
978 #endif
979 			j_exit();
980 			if (ep->flags & EF_FAKE_SIGDIE) {
981 				int sig = (exstat & 0xFF) - 128;
982 
983 				/*
984 				 * ham up our death a bit (AT&T ksh
985 				 * only seems to do this for SIGTERM)
986 				 * Don't do it for SIGQUIT, since we'd
987 				 * dump a core..
988 				 */
989 				if ((sig == SIGINT || sig == SIGTERM) &&
990 				    (kshpgrp == kshpid)) {
991 					setsig(&sigtraps[sig], SIG_DFL,
992 					    SS_RESTORE_CURR | SS_FORCE);
993 					kill(0, sig);
994 				}
995 			}
996 		}
997 		if (shf)
998 			shf_close(shf);
999 		reclaim();
1000 #ifdef DEBUG_LEAKS
1001 #ifndef MKSH_NO_CMDLINE_EDITING
1002 		x_done();
1003 #endif
1004 #ifndef MKSH_NOPROSPECTOFWORK
1005 		/* block at least SIGCHLD during/after afreeall */
1006 		sigprocmask(SIG_BLOCK, &sm_sigchld, NULL);
1007 #endif
1008 		afreeall(APERM);
1009 		for (fd = 3; fd < NUFILE; fd++)
1010 			if ((i = fcntl(fd, F_GETFD, 0)) != -1 &&
1011 			    (i & FD_CLOEXEC))
1012 				close(fd);
1013 		close(2);
1014 		close(1);
1015 		close(0);
1016 #endif
1017 		exit(exstat & 0xFF);
1018 	}
1019 	if (shf)
1020 		shf_close(shf);
1021 	reclaim();
1022 
1023 	e = e->oenv;
1024 
1025 	/* free the struct env - tricky due to the ALLOC_ITEM inside */
1026 	cp = (void *)ep;
1027 	afree(cp + ALLOC_SIZE, ATEMP);
1028 }
1029 
1030 /* Called after a fork to cleanup stuff left over from parents environment */
1031 void
cleanup_parents_env(void)1032 cleanup_parents_env(void)
1033 {
1034 	struct env *ep;
1035 	int fd;
1036 
1037 	/*
1038 	 * Don't clean up temporary files - parent will probably need them.
1039 	 * Also, can't easily reclaim memory since variables, etc. could be
1040 	 * anywhere.
1041 	 */
1042 
1043 	/* close all file descriptors hiding in savefd */
1044 	for (ep = e; ep; ep = ep->oenv) {
1045 		if (ep->savefd) {
1046 			for (fd = 0; fd < NUFILE; fd++)
1047 				if (ep->savefd[fd] > 0)
1048 					close(ep->savefd[fd]);
1049 			afree(ep->savefd, &ep->area);
1050 			ep->savefd = NULL;
1051 		}
1052 #ifdef DEBUG_LEAKS
1053 		if (ep->type != E_NONE)
1054 			ep->type = E_GONE;
1055 #endif
1056 	}
1057 #ifndef DEBUG_LEAKS
1058 	e->oenv = NULL;
1059 #endif
1060 }
1061 
1062 /* Called just before an execve cleanup stuff temporary files */
1063 void
cleanup_proc_env(void)1064 cleanup_proc_env(void)
1065 {
1066 	struct env *ep;
1067 
1068 	for (ep = e; ep; ep = ep->oenv)
1069 		remove_temps(ep->temps);
1070 }
1071 
1072 /* remove temp files and free ATEMP Area */
1073 static void
reclaim(void)1074 reclaim(void)
1075 {
1076 	struct block *l;
1077 
1078 	while ((l = e->loc) && (!e->oenv || e->oenv->loc != l)) {
1079 		e->loc = l->next;
1080 		afreeall(&l->area);
1081 	}
1082 
1083 	remove_temps(e->temps);
1084 	e->temps = NULL;
1085 	afreeall(&e->area);
1086 }
1087 
1088 static void
remove_temps(struct temp * tp)1089 remove_temps(struct temp *tp)
1090 {
1091 	for (; tp != NULL; tp = tp->next)
1092 		if (tp->pid == procpid)
1093 			unlink(tp->tffn);
1094 }
1095 
1096 /*
1097  * Initialise tty_fd. Used for tracking the size of the terminal,
1098  * saving/resetting tty modes upon forground job completion, and
1099  * for setting up the tty process group. Return values:
1100  *	0 = got controlling tty
1101  *	1 = got terminal but no controlling tty
1102  *	2 = cannot find a terminal
1103  *	3 = cannot dup fd
1104  *	4 = cannot make fd close-on-exec
1105  * An existing tty_fd is cached if no "better" one could be found,
1106  * i.e. if tty_devtty was already set or the new would not set it.
1107  */
1108 int
tty_init_fd(void)1109 tty_init_fd(void)
1110 {
1111 	int fd, rv, eno = 0;
1112 	bool do_close = false, is_devtty = true;
1113 
1114 	if (tty_devtty) {
1115 		/* already got a tty which is /dev/tty */
1116 		return (0);
1117 	}
1118 
1119 #ifdef _UWIN
1120 	/*XXX imake style */
1121 	if (isatty(3)) {
1122 		/* fd 3 on UWIN _is_ /dev/tty (or our controlling tty) */
1123 		fd = 3;
1124 		goto got_fd;
1125 	}
1126 #endif
1127 	if ((fd = open("/dev/tty", O_RDWR, 0)) >= 0) {
1128 		do_close = true;
1129 		goto got_fd;
1130 	}
1131 	eno = errno;
1132 
1133 	if (tty_fd >= 0) {
1134 		/* already got a non-devtty one */
1135 		rv = 1;
1136 		goto out;
1137 	}
1138 	is_devtty = false;
1139 
1140 	if (isatty((fd = 0)) || isatty((fd = 2)))
1141 		goto got_fd;
1142 	/* cannot find one */
1143 	rv = 2;
1144 	/* assert: do_close == false */
1145 	goto out;
1146 
1147  got_fd:
1148 	if ((rv = fcntl(fd, F_DUPFD, FDBASE)) < 0) {
1149 		eno = errno;
1150 		rv = 3;
1151 		goto out;
1152 	}
1153 	if (fcntl(rv, F_SETFD, FD_CLOEXEC) < 0) {
1154 		eno = errno;
1155 		close(rv);
1156 		rv = 4;
1157 		goto out;
1158 	}
1159 	tty_fd = rv;
1160 	tty_devtty = is_devtty;
1161 	rv = eno = 0;
1162  out:
1163 	if (do_close)
1164 		close(fd);
1165 	errno = eno;
1166 	return (rv);
1167 }
1168 
1169 /* A shell error occurred (eg, syntax error, etc.) */
1170 
1171 #define VWARNINGF_ERRORPREFIX	1
1172 #define VWARNINGF_FILELINE	2
1173 #define VWARNINGF_BUILTIN	4
1174 #define VWARNINGF_INTERNAL	8
1175 
1176 static void vwarningf(unsigned int, const char *, va_list)
1177     MKSH_A_FORMAT(__printf__, 2, 0);
1178 
1179 static void
vwarningf(unsigned int flags,const char * fmt,va_list ap)1180 vwarningf(unsigned int flags, const char *fmt, va_list ap)
1181 {
1182 	if (fmt) {
1183 		if (flags & VWARNINGF_INTERNAL)
1184 			shf_fprintf(shl_out, "internal error: ");
1185 		if (flags & VWARNINGF_ERRORPREFIX)
1186 			error_prefix(tobool(flags & VWARNINGF_FILELINE));
1187 		if ((flags & VWARNINGF_BUILTIN) &&
1188 		    /* not set when main() calls parse_args() */
1189 		    builtin_argv0 && builtin_argv0 != kshname)
1190 			shf_fprintf(shl_out, "%s: ", builtin_argv0);
1191 		shf_vfprintf(shl_out, fmt, ap);
1192 		shf_putchar('\n', shl_out);
1193 	}
1194 	shf_flush(shl_out);
1195 }
1196 
1197 void
errorfx(int rc,const char * fmt,...)1198 errorfx(int rc, const char *fmt, ...)
1199 {
1200 	va_list va;
1201 
1202 	exstat = rc;
1203 
1204 	/* debugging: note that stdout not valid */
1205 	shl_stdout_ok = false;
1206 
1207 	va_start(va, fmt);
1208 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1209 	va_end(va);
1210 	unwind(LERROR);
1211 }
1212 
1213 void
errorf(const char * fmt,...)1214 errorf(const char *fmt, ...)
1215 {
1216 	va_list va;
1217 
1218 	exstat = 1;
1219 
1220 	/* debugging: note that stdout not valid */
1221 	shl_stdout_ok = false;
1222 
1223 	va_start(va, fmt);
1224 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1225 	va_end(va);
1226 	unwind(LERROR);
1227 }
1228 
1229 /* like errorf(), but no unwind is done */
1230 void
warningf(bool fileline,const char * fmt,...)1231 warningf(bool fileline, const char *fmt, ...)
1232 {
1233 	va_list va;
1234 
1235 	va_start(va, fmt);
1236 	vwarningf(VWARNINGF_ERRORPREFIX | (fileline ? VWARNINGF_FILELINE : 0),
1237 	    fmt, va);
1238 	va_end(va);
1239 }
1240 
1241 /*
1242  * Used by built-in utilities to prefix shell and utility name to message
1243  * (also unwinds environments for special builtins).
1244  */
1245 void
bi_errorf(const char * fmt,...)1246 bi_errorf(const char *fmt, ...)
1247 {
1248 	va_list va;
1249 
1250 	/* debugging: note that stdout not valid */
1251 	shl_stdout_ok = false;
1252 
1253 	exstat = 1;
1254 
1255 	va_start(va, fmt);
1256 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE |
1257 	    VWARNINGF_BUILTIN, fmt, va);
1258 	va_end(va);
1259 
1260 	/*
1261 	 * POSIX special builtins and ksh special builtins cause
1262 	 * non-interactive shells to exit. XXX may not want LERROR here
1263 	 */
1264 	if (builtin_spec) {
1265 		builtin_argv0 = NULL;
1266 		unwind(LERROR);
1267 	}
1268 }
1269 
1270 /* Called when something that shouldn't happen does */
1271 void
internal_errorf(const char * fmt,...)1272 internal_errorf(const char *fmt, ...)
1273 {
1274 	va_list va;
1275 
1276 	va_start(va, fmt);
1277 	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1278 	va_end(va);
1279 	unwind(LERROR);
1280 }
1281 
1282 void
internal_warningf(const char * fmt,...)1283 internal_warningf(const char *fmt, ...)
1284 {
1285 	va_list va;
1286 
1287 	va_start(va, fmt);
1288 	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1289 	va_end(va);
1290 }
1291 
1292 /* used by error reporting functions to print "ksh: .kshrc[25]: " */
1293 void
error_prefix(bool fileline)1294 error_prefix(bool fileline)
1295 {
1296 	/* Avoid foo: foo[2]: ... */
1297 	if (!fileline || !source || !source->file ||
1298 	    strcmp(source->file, kshname) != 0)
1299 		shf_fprintf(shl_out, "%s: ", kshname + (*kshname == '-'));
1300 	if (fileline && source && source->file != NULL) {
1301 		shf_fprintf(shl_out, "%s[%lu]: ", source->file,
1302 		    (unsigned long)(source->errline ?
1303 		    source->errline : source->line));
1304 		source->errline = 0;
1305 	}
1306 }
1307 
1308 /* printf to shl_out (stderr) with flush */
1309 void
shellf(const char * fmt,...)1310 shellf(const char *fmt, ...)
1311 {
1312 	va_list va;
1313 
1314 	if (!initio_done)
1315 		/* shl_out may not be set up yet... */
1316 		return;
1317 	va_start(va, fmt);
1318 	shf_vfprintf(shl_out, fmt, va);
1319 	va_end(va);
1320 	shf_flush(shl_out);
1321 }
1322 
1323 /* printf to shl_stdout (stdout) */
1324 void
shprintf(const char * fmt,...)1325 shprintf(const char *fmt, ...)
1326 {
1327 	va_list va;
1328 
1329 	if (!shl_stdout_ok)
1330 		internal_errorf("shl_stdout not valid");
1331 	va_start(va, fmt);
1332 	shf_vfprintf(shl_stdout, fmt, va);
1333 	va_end(va);
1334 }
1335 
1336 /* test if we can seek backwards fd (returns 0 or SHF_UNBUF) */
1337 int
can_seek(int fd)1338 can_seek(int fd)
1339 {
1340 	struct stat statb;
1341 
1342 	return (fstat(fd, &statb) == 0 && !S_ISREG(statb.st_mode) ?
1343 	    SHF_UNBUF : 0);
1344 }
1345 
1346 #ifdef DF
1347 int shl_dbg_fd;
1348 #define NSHF_IOB 4
1349 #else
1350 #define NSHF_IOB 3
1351 #endif
1352 struct shf shf_iob[NSHF_IOB];
1353 
1354 void
initio(void)1355 initio(void)
1356 {
1357 #ifdef DF
1358 	const char *lfp;
1359 #endif
1360 
1361 	/* force buffer allocation */
1362 	shf_fdopen(1, SHF_WR, shl_stdout);
1363 	shf_fdopen(2, SHF_WR, shl_out);
1364 	shf_fdopen(2, SHF_WR, shl_xtrace);
1365 #ifdef DF
1366 	if ((lfp = getenv("SDMKSH_PATH")) == NULL) {
1367 		if ((lfp = getenv("HOME")) == NULL || !mksh_abspath(lfp))
1368 			errorf("cannot get home directory");
1369 		lfp = shf_smprintf("%s/mksh-dbg.txt", lfp);
1370 	}
1371 
1372 	if ((shl_dbg_fd = open(lfp, O_WRONLY | O_APPEND | O_CREAT, 0600)) < 0)
1373 		errorf("cannot open debug output file %s", lfp);
1374 	if (shl_dbg_fd < FDBASE) {
1375 		int nfd;
1376 
1377 		nfd = fcntl(shl_dbg_fd, F_DUPFD, FDBASE);
1378 		close(shl_dbg_fd);
1379 		if ((shl_dbg_fd = nfd) == -1)
1380 			errorf("cannot dup debug output file");
1381 	}
1382 	fcntl(shl_dbg_fd, F_SETFD, FD_CLOEXEC);
1383 	shf_fdopen(shl_dbg_fd, SHF_WR, shl_dbg);
1384 	DF("=== open ===");
1385 #endif
1386 	initio_done = true;
1387 }
1388 
1389 /* A dup2() with error checking */
1390 int
ksh_dup2(int ofd,int nfd,bool errok)1391 ksh_dup2(int ofd, int nfd, bool errok)
1392 {
1393 	int rv;
1394 
1395 	if (((rv = dup2(ofd, nfd)) < 0) && !errok && (errno != EBADF))
1396 		errorf("too many files open in shell");
1397 
1398 #ifdef __ultrix
1399 	/*XXX imake style */
1400 	if (rv >= 0)
1401 		fcntl(nfd, F_SETFD, 0);
1402 #endif
1403 
1404 	return (rv);
1405 }
1406 
1407 /*
1408  * Move fd from user space (0 <= fd < 10) to shell space (fd >= 10),
1409  * set close-on-exec flag. See FDBASE in sh.h, maybe 24 not 10 here.
1410  */
1411 short
savefd(int fd)1412 savefd(int fd)
1413 {
1414 	int nfd = fd;
1415 
1416 	if (fd < FDBASE && (nfd = fcntl(fd, F_DUPFD, FDBASE)) < 0 &&
1417 	    (errno == EBADF || errno == EPERM))
1418 		return (-1);
1419 	if (nfd < 0 || nfd > SHRT_MAX)
1420 		errorf("too many files open in shell");
1421 	fcntl(nfd, F_SETFD, FD_CLOEXEC);
1422 	return ((short)nfd);
1423 }
1424 
1425 void
restfd(int fd,int ofd)1426 restfd(int fd, int ofd)
1427 {
1428 	if (fd == 2)
1429 		shf_flush(&shf_iob[/* fd */ 2]);
1430 	if (ofd < 0)
1431 		/* original fd closed */
1432 		close(fd);
1433 	else if (fd != ofd) {
1434 		/*XXX: what to do if this dup fails? */
1435 		ksh_dup2(ofd, fd, true);
1436 		close(ofd);
1437 	}
1438 }
1439 
1440 void
openpipe(int * pv)1441 openpipe(int *pv)
1442 {
1443 	int lpv[2];
1444 
1445 	if (pipe(lpv) < 0)
1446 		errorf("can't create pipe - try again");
1447 	pv[0] = savefd(lpv[0]);
1448 	if (pv[0] != lpv[0])
1449 		close(lpv[0]);
1450 	pv[1] = savefd(lpv[1]);
1451 	if (pv[1] != lpv[1])
1452 		close(lpv[1]);
1453 }
1454 
1455 void
closepipe(int * pv)1456 closepipe(int *pv)
1457 {
1458 	close(pv[0]);
1459 	close(pv[1]);
1460 }
1461 
1462 /*
1463  * Called by iosetup() (deals with 2>&4, etc.), c_read, c_print to turn
1464  * a string (the X in 2>&X, read -uX, print -uX) into a file descriptor.
1465  */
1466 int
check_fd(const char * name,int mode,const char ** emsgp)1467 check_fd(const char *name, int mode, const char **emsgp)
1468 {
1469 	int fd = 0, fl;
1470 
1471 	if (name[0] == 'p' && !name[1])
1472 		return (coproc_getfd(mode, emsgp));
1473 	while (ksh_isdigit(*name)) {
1474 		fd = fd * 10 + ksh_numdig(*name);
1475 		if (fd >= FDBASE) {
1476 			if (emsgp)
1477 				*emsgp = "file descriptor too large";
1478 			return (-1);
1479 		}
1480 		++name;
1481 	}
1482 	if (*name) {
1483 		if (emsgp)
1484 			*emsgp = "illegal file descriptor name";
1485 		return (-1);
1486 	}
1487 	if ((fl = fcntl(fd, F_GETFL, 0)) < 0) {
1488 		if (emsgp)
1489 			*emsgp = "bad file descriptor";
1490 		return (-1);
1491 	}
1492 	fl &= O_ACCMODE;
1493 	/*
1494 	 * X_OK is a kludge to disable this check for dups (x<&1):
1495 	 * historical shells never did this check (XXX don't know what
1496 	 * POSIX has to say).
1497 	 */
1498 	if (!(mode & X_OK) && fl != O_RDWR && (
1499 	    ((mode & R_OK) && fl != O_RDONLY) ||
1500 	    ((mode & W_OK) && fl != O_WRONLY))) {
1501 		if (emsgp)
1502 			*emsgp = (fl == O_WRONLY) ?
1503 			    "fd not open for reading" :
1504 			    "fd not open for writing";
1505 		return (-1);
1506 	}
1507 	return (fd);
1508 }
1509 
1510 /* Called once from main */
1511 void
coproc_init(void)1512 coproc_init(void)
1513 {
1514 	coproc.read = coproc.readw = coproc.write = -1;
1515 	coproc.njobs = 0;
1516 	coproc.id = 0;
1517 }
1518 
1519 /* Called by c_read() when eof is read - close fd if it is the co-process fd */
1520 void
coproc_read_close(int fd)1521 coproc_read_close(int fd)
1522 {
1523 	if (coproc.read >= 0 && fd == coproc.read) {
1524 		coproc_readw_close(fd);
1525 		close(coproc.read);
1526 		coproc.read = -1;
1527 	}
1528 }
1529 
1530 /*
1531  * Called by c_read() and by iosetup() to close the other side of the
1532  * read pipe, so reads will actually terminate.
1533  */
1534 void
coproc_readw_close(int fd)1535 coproc_readw_close(int fd)
1536 {
1537 	if (coproc.readw >= 0 && coproc.read >= 0 && fd == coproc.read) {
1538 		close(coproc.readw);
1539 		coproc.readw = -1;
1540 	}
1541 }
1542 
1543 /*
1544  * Called by c_print when a write to a fd fails with EPIPE and by iosetup
1545  * when co-process input is dup'd
1546  */
1547 void
coproc_write_close(int fd)1548 coproc_write_close(int fd)
1549 {
1550 	if (coproc.write >= 0 && fd == coproc.write) {
1551 		close(coproc.write);
1552 		coproc.write = -1;
1553 	}
1554 }
1555 
1556 /*
1557  * Called to check for existence of/value of the co-process file descriptor.
1558  * (Used by check_fd() and by c_read/c_print to deal with -p option).
1559  */
1560 int
coproc_getfd(int mode,const char ** emsgp)1561 coproc_getfd(int mode, const char **emsgp)
1562 {
1563 	int fd = (mode & R_OK) ? coproc.read : coproc.write;
1564 
1565 	if (fd >= 0)
1566 		return (fd);
1567 	if (emsgp)
1568 		*emsgp = "no coprocess";
1569 	return (-1);
1570 }
1571 
1572 /*
1573  * called to close file descriptors related to the coprocess (if any)
1574  * Should be called with SIGCHLD blocked.
1575  */
1576 void
coproc_cleanup(int reuse)1577 coproc_cleanup(int reuse)
1578 {
1579 	/* This to allow co-processes to share output pipe */
1580 	if (!reuse || coproc.readw < 0 || coproc.read < 0) {
1581 		if (coproc.read >= 0) {
1582 			close(coproc.read);
1583 			coproc.read = -1;
1584 		}
1585 		if (coproc.readw >= 0) {
1586 			close(coproc.readw);
1587 			coproc.readw = -1;
1588 		}
1589 	}
1590 	if (coproc.write >= 0) {
1591 		close(coproc.write);
1592 		coproc.write = -1;
1593 	}
1594 }
1595 
1596 struct temp *
maketemp(Area * ap,Temp_type type,struct temp ** tlist)1597 maketemp(Area *ap, Temp_type type, struct temp **tlist)
1598 {
1599 	char *cp;
1600 	size_t len;
1601 	int i, j;
1602 	struct temp *tp;
1603 	const char *dir;
1604 	struct stat sb;
1605 
1606 	dir = tmpdir ? tmpdir : MKSH_DEFAULT_TMPDIR;
1607 	/* add "/shXXXXXX.tmp" plus NUL */
1608 	len = strlen(dir);
1609 	checkoktoadd(len, offsetof(struct temp, tffn[0]) + 14);
1610 	tp = alloc(offsetof(struct temp, tffn[0]) + 14 + len, ap);
1611 
1612 	tp->shf = NULL;
1613 	tp->pid = procpid;
1614 	tp->type = type;
1615 
1616 	if (stat(dir, &sb) || !S_ISDIR(sb.st_mode)) {
1617 		tp->tffn[0] = '\0';
1618 		goto maketemp_out;
1619 	}
1620 
1621 	cp = (void *)tp;
1622 	cp += offsetof(struct temp, tffn[0]);
1623 	memcpy(cp, dir, len);
1624 	cp += len;
1625 	memcpy(cp, "/shXXXXXX.tmp", 14);
1626 	/* point to the first of six Xes */
1627 	cp += 3;
1628 
1629 	/* cyclically attempt to open a temporary file */
1630 	do {
1631 		/* generate random part of filename */
1632 		len = 0;
1633 		do {
1634 			cp[len++] = digits_lc[rndget() % 36];
1635 		} while (len < 6);
1636 
1637 		/* check if this one works */
1638 		if ((i = binopen3(tp->tffn, O_CREAT | O_EXCL | O_RDWR,
1639 		    0600)) < 0 && errno != EEXIST)
1640 			goto maketemp_out;
1641 	} while (i < 0);
1642 
1643 	if (type == TT_FUNSUB) {
1644 		/* map us high and mark as close-on-exec */
1645 		if ((j = savefd(i)) != i) {
1646 			close(i);
1647 			i = j;
1648 		}
1649 
1650 		/* operation mode for the shf */
1651 		j = SHF_RD;
1652 	} else
1653 		j = SHF_WR;
1654 
1655 	/* shf_fdopen cannot fail, so no fd leak */
1656 	tp->shf = shf_fdopen(i, j, NULL);
1657 
1658  maketemp_out:
1659 	tp->next = *tlist;
1660 	*tlist = tp;
1661 	return (tp);
1662 }
1663 
1664 /*
1665  * We use a similar collision resolution algorithm as Python 2.5.4
1666  * but with a slightly tweaked implementation written from scratch.
1667  */
1668 
1669 #define	INIT_TBLSHIFT	3	/* initial table shift (2^3 = 8) */
1670 #define PERTURB_SHIFT	5	/* see Python 2.5.4 Objects/dictobject.c */
1671 
1672 static void tgrow(struct table *);
1673 static int tnamecmp(const void *, const void *);
1674 
1675 static void
tgrow(struct table * tp)1676 tgrow(struct table *tp)
1677 {
1678 	size_t i, j, osize, mask, perturb;
1679 	struct tbl *tblp, **pp;
1680 	struct tbl **ntblp, **otblp = tp->tbls;
1681 
1682 	if (tp->tshift > 29)
1683 		internal_errorf("hash table size limit reached");
1684 
1685 	/* calculate old size, new shift and new size */
1686 	osize = (size_t)1 << (tp->tshift++);
1687 	i = osize << 1;
1688 
1689 	ntblp = alloc2(i, sizeof(struct tbl *), tp->areap);
1690 	/* multiplication cannot overflow: alloc2 checked that */
1691 	memset(ntblp, 0, i * sizeof(struct tbl *));
1692 
1693 	/* table can get very full when reaching its size limit */
1694 	tp->nfree = (tp->tshift == 30) ? 0x3FFF0000UL :
1695 	    /* but otherwise, only 75% */
1696 	    ((i * 3) / 4);
1697 	tp->tbls = ntblp;
1698 	if (otblp == NULL)
1699 		return;
1700 
1701 	mask = i - 1;
1702 	for (i = 0; i < osize; i++)
1703 		if ((tblp = otblp[i]) != NULL) {
1704 			if ((tblp->flag & DEFINED)) {
1705 				/* search for free hash table slot */
1706 				j = perturb = tblp->ua.hval;
1707 				goto find_first_empty_slot;
1708  find_next_empty_slot:
1709 				j = (j << 2) + j + perturb + 1;
1710 				perturb >>= PERTURB_SHIFT;
1711  find_first_empty_slot:
1712 				pp = &ntblp[j & mask];
1713 				if (*pp != NULL)
1714 					goto find_next_empty_slot;
1715 				/* found an empty hash table slot */
1716 				*pp = tblp;
1717 				tp->nfree--;
1718 			} else if (!(tblp->flag & FINUSE)) {
1719 				afree(tblp, tp->areap);
1720 			}
1721 		}
1722 	afree(otblp, tp->areap);
1723 }
1724 
1725 void
ktinit(Area * ap,struct table * tp,uint8_t initshift)1726 ktinit(Area *ap, struct table *tp, uint8_t initshift)
1727 {
1728 	tp->areap = ap;
1729 	tp->tbls = NULL;
1730 	tp->tshift = ((initshift > INIT_TBLSHIFT) ?
1731 	    initshift : INIT_TBLSHIFT) - 1;
1732 	tgrow(tp);
1733 }
1734 
1735 /* table, name (key) to search for, hash(name), rv pointer to tbl ptr */
1736 struct tbl *
ktscan(struct table * tp,const char * name,uint32_t h,struct tbl *** ppp)1737 ktscan(struct table *tp, const char *name, uint32_t h, struct tbl ***ppp)
1738 {
1739 	size_t j, perturb, mask;
1740 	struct tbl **pp, *p;
1741 
1742 	mask = ((size_t)1 << (tp->tshift)) - 1;
1743 	/* search for hash table slot matching name */
1744 	j = perturb = h;
1745 	goto find_first_slot;
1746  find_next_slot:
1747 	j = (j << 2) + j + perturb + 1;
1748 	perturb >>= PERTURB_SHIFT;
1749  find_first_slot:
1750 	pp = &tp->tbls[j & mask];
1751 	if ((p = *pp) != NULL && (p->ua.hval != h || !(p->flag & DEFINED) ||
1752 	    strcmp(p->name, name)))
1753 		goto find_next_slot;
1754 	/* p == NULL if not found, correct found entry otherwise */
1755 	if (ppp)
1756 		*ppp = pp;
1757 	return (p);
1758 }
1759 
1760 /* table, name (key) to enter, hash(n) */
1761 struct tbl *
ktenter(struct table * tp,const char * n,uint32_t h)1762 ktenter(struct table *tp, const char *n, uint32_t h)
1763 {
1764 	struct tbl **pp, *p;
1765 	size_t len;
1766 
1767  Search:
1768 	if ((p = ktscan(tp, n, h, &pp)))
1769 		return (p);
1770 
1771 	if (tp->nfree == 0) {
1772 		/* too full */
1773 		tgrow(tp);
1774 		goto Search;
1775 	}
1776 
1777 	/* create new tbl entry */
1778 	len = strlen(n);
1779 	checkoktoadd(len, offsetof(struct tbl, name[0]) + 1);
1780 	p = alloc(offsetof(struct tbl, name[0]) + ++len, tp->areap);
1781 	p->flag = 0;
1782 	p->type = 0;
1783 	p->areap = tp->areap;
1784 	p->ua.hval = h;
1785 	p->u2.field = 0;
1786 	p->u.array = NULL;
1787 	memcpy(p->name, n, len);
1788 
1789 	/* enter in tp->tbls */
1790 	tp->nfree--;
1791 	*pp = p;
1792 	return (p);
1793 }
1794 
1795 void
ktwalk(struct tstate * ts,struct table * tp)1796 ktwalk(struct tstate *ts, struct table *tp)
1797 {
1798 	ts->left = (size_t)1 << (tp->tshift);
1799 	ts->next = tp->tbls;
1800 }
1801 
1802 struct tbl *
ktnext(struct tstate * ts)1803 ktnext(struct tstate *ts)
1804 {
1805 	while (--ts->left >= 0) {
1806 		struct tbl *p = *ts->next++;
1807 		if (p != NULL && (p->flag & DEFINED))
1808 			return (p);
1809 	}
1810 	return (NULL);
1811 }
1812 
1813 static int
tnamecmp(const void * p1,const void * p2)1814 tnamecmp(const void *p1, const void *p2)
1815 {
1816 	const struct tbl *a = *((const struct tbl * const *)p1);
1817 	const struct tbl *b = *((const struct tbl * const *)p2);
1818 
1819 	return (strcmp(a->name, b->name));
1820 }
1821 
1822 struct tbl **
ktsort(struct table * tp)1823 ktsort(struct table *tp)
1824 {
1825 	size_t i;
1826 	struct tbl **p, **sp, **dp;
1827 
1828 	/*
1829 	 * since the table is never entirely full, no need to reserve
1830 	 * additional space for the trailing NULL appended below
1831 	 */
1832 	i = (size_t)1 << (tp->tshift);
1833 	p = alloc2(i, sizeof(struct tbl *), ATEMP);
1834 	sp = tp->tbls;		/* source */
1835 	dp = p;			/* dest */
1836 	while (i--)
1837 		if ((*dp = *sp++) != NULL && (((*dp)->flag & DEFINED) ||
1838 		    ((*dp)->flag & ARRAY)))
1839 			dp++;
1840 	qsort(p, (i = dp - p), sizeof(struct tbl *), tnamecmp);
1841 	p[i] = NULL;
1842 	return (p);
1843 }
1844 
1845 #ifdef SIGWINCH
1846 static void
x_sigwinch(int sig MKSH_A_UNUSED)1847 x_sigwinch(int sig MKSH_A_UNUSED)
1848 {
1849 	/* this runs inside interrupt context, with errno saved */
1850 
1851 	got_winch = 1;
1852 }
1853 #endif
1854 
1855 #ifdef DF
1856 void
DF(const char * fmt,...)1857 DF(const char *fmt, ...)
1858 {
1859 	va_list args;
1860 	struct timeval tv;
1861 	mirtime_mjd mjd;
1862 
1863 	mksh_lockfd(shl_dbg_fd);
1864 	mksh_TIME(tv);
1865 	timet2mjd(&mjd, tv.tv_sec);
1866 	shf_fprintf(shl_dbg, "[%02u:%02u:%02u (%u) %u.%06u] ",
1867 	    (unsigned)mjd.sec / 3600, ((unsigned)mjd.sec / 60) % 60,
1868 	    (unsigned)mjd.sec % 60, (unsigned)getpid(),
1869 	    (unsigned)tv.tv_sec, (unsigned)tv.tv_usec);
1870 	va_start(args, fmt);
1871 	shf_vfprintf(shl_dbg, fmt, args);
1872 	va_end(args);
1873 	shf_putc('\n', shl_dbg);
1874 	shf_flush(shl_dbg);
1875 	mksh_unlkfd(shl_dbg_fd);
1876 }
1877 #endif
1878 
1879 void
x_mkraw(int fd,mksh_ttyst * ocb,bool forread)1880 x_mkraw(int fd, mksh_ttyst *ocb, bool forread)
1881 {
1882 	mksh_ttyst cb;
1883 
1884 	if (ocb)
1885 		mksh_tcget(fd, ocb);
1886 	else
1887 		ocb = &tty_state;
1888 
1889 	cb = *ocb;
1890 	if (forread) {
1891 		cb.c_iflag &= ~(ISTRIP);
1892 		cb.c_lflag &= ~(ICANON) | ECHO;
1893 	} else {
1894 		cb.c_iflag &= ~(INLCR | ICRNL | ISTRIP);
1895 		cb.c_lflag &= ~(ISIG | ICANON | ECHO);
1896 	}
1897 #if defined(VLNEXT) && defined(_POSIX_VDISABLE)
1898 	/* OSF/1 processes lnext when ~icanon */
1899 	cb.c_cc[VLNEXT] = _POSIX_VDISABLE;
1900 #endif
1901 	/* SunOS 4.1.x & OSF/1 processes discard(flush) when ~icanon */
1902 #if defined(VDISCARD) && defined(_POSIX_VDISABLE)
1903 	cb.c_cc[VDISCARD] = _POSIX_VDISABLE;
1904 #endif
1905 	cb.c_cc[VTIME] = 0;
1906 	cb.c_cc[VMIN] = 1;
1907 
1908 	mksh_tcset(fd, &cb);
1909 }
1910