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1 /*	$OpenBSD: main.c,v 1.54 2013/11/28 10:33:37 sobrado Exp $	*/
2 /*	$OpenBSD: tty.c,v 1.10 2014/08/10 02:44:26 guenther Exp $	*/
3 /*	$OpenBSD: io.c,v 1.25 2014/08/11 20:28:47 guenther Exp $	*/
4 /*	$OpenBSD: table.c,v 1.15 2012/02/19 07:52:30 otto Exp $	*/
5 
6 /*-
7  * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
8  *		 2011, 2012, 2013, 2014
9  *	Thorsten Glaser <tg@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 1.284 2014/10/03 17:19:27 tg Exp $");
38 
39 extern char **environ;
40 
41 #ifndef MKSHRC_PATH
42 #define MKSHRC_PATH	"~/.mkshrc"
43 #endif
44 
45 #ifndef MKSH_DEFAULT_TMPDIR
46 #define MKSH_DEFAULT_TMPDIR	"/tmp"
47 #endif
48 
49 static uint8_t isuc(const char *);
50 static int main_init(int, const char *[], Source **, struct block **);
51 void chvt_reinit(void);
52 static void reclaim(void);
53 static void remove_temps(struct temp *);
54 static mksh_uari_t rndsetup(void);
55 #ifdef SIGWINCH
56 static void x_sigwinch(int);
57 #endif
58 
59 static const char initifs[] = "IFS= \t\n";
60 
61 static const char initsubs[] =
62     "${PS2=> } ${PS3=#? } ${PS4=+ } ${SECONDS=0} ${TMOUT=0} ${EPOCHREALTIME=}";
63 
64 static const char *initcoms[] = {
65 	Ttypeset, "-r", initvsn, NULL,
66 	Ttypeset, "-x", "HOME", "PATH", "SHELL", NULL,
67 	Ttypeset, "-i10", "COLUMNS", "LINES", "SECONDS", "TMOUT", NULL,
68 	Talias,
69 	"integer=typeset -i",
70 	Tlocal_typeset,
71 	/* not "alias -t --": hash -r needs to work */
72 	"hash=alias -t",
73 	"type=whence -v",
74 #if !defined(ANDROID) && !defined(MKSH_UNEMPLOYED)
75 	/* not in Android for political reasons */
76 	/* not in ARGE mksh due to no job control */
77 	"stop=kill -STOP",
78 #endif
79 	"autoload=typeset -fu",
80 	"functions=typeset -f",
81 	"history=fc -l",
82 	"nameref=typeset -n",
83 	"nohup=nohup ",
84 	Tr_fc_e_dash,
85 	"source=PATH=$PATH:. command .",
86 	"login=exec login",
87 	NULL,
88 	 /* this is what AT&T ksh seems to track, with the addition of emacs */
89 	Talias, "-tU",
90 	"cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
91 	"make", "mv", "pr", "rm", "sed", "sh", "vi", "who", NULL,
92 	NULL
93 };
94 
95 static const char *restr_com[] = {
96 	Ttypeset, "-r", "PATH", "ENV", "SHELL", NULL
97 };
98 
99 static bool initio_done;
100 
101 /* top-level parsing and execution environment */
102 static struct env env;
103 struct env *e = &env;
104 
105 static mksh_uari_t
rndsetup(void)106 rndsetup(void)
107 {
108 	register uint32_t h;
109 	struct {
110 		ALLOC_ITEM alloc_INT;
111 		void *dataptr, *stkptr, *mallocptr;
112 #if defined(__GLIBC__) && (__GLIBC__ >= 2)
113 		sigjmp_buf jbuf;
114 #endif
115 		struct timeval tv;
116 	} *bufptr;
117 	char *cp;
118 
119 	cp = alloc(sizeof(*bufptr) - ALLOC_SIZE, APERM);
120 #ifdef DEBUG
121 	/* clear the allocated space, for valgrind */
122 	memset(cp, 0, sizeof(*bufptr) - ALLOC_SIZE);
123 #endif
124 	/* undo what alloc() did to the malloc result address */
125 	bufptr = (void *)(cp - ALLOC_SIZE);
126 	/* PIE or something similar provides us with deltas here */
127 	bufptr->dataptr = &rndsetupstate;
128 	/* ASLR in at least Windows, Linux, some BSDs */
129 	bufptr->stkptr = &bufptr;
130 	/* randomised malloc in BSD (and possibly others) */
131 	bufptr->mallocptr = bufptr;
132 #if defined(__GLIBC__) && (__GLIBC__ >= 2)
133 	/* glibc pointer guard */
134 	sigsetjmp(bufptr->jbuf, 1);
135 #endif
136 	/* introduce variation (and yes, second arg MBZ for portability) */
137 	mksh_TIME(bufptr->tv);
138 
139 	h = chvt_rndsetup(bufptr, sizeof(*bufptr));
140 
141 	afree(cp, APERM);
142 	return ((mksh_uari_t)h);
143 }
144 
145 void
chvt_reinit(void)146 chvt_reinit(void)
147 {
148 	kshpid = procpid = getpid();
149 	ksheuid = geteuid();
150 	kshpgrp = getpgrp();
151 	kshppid = getppid();
152 }
153 
154 static const char *empty_argv[] = {
155 	"mksh", NULL
156 };
157 
158 static uint8_t
isuc(const char * cx)159 isuc(const char *cx) {
160 	char *cp, *x;
161 	uint8_t rv = 0;
162 
163 	if (!cx || !*cx)
164 		return (0);
165 
166 	/* uppercase a string duplicate */
167 	strdupx(x, cx, ATEMP);
168 	cp = x;
169 	while ((*cp = ksh_toupper(*cp)))
170 		++cp;
171 
172 	/* check for UTF-8 */
173 	if (strstr(x, "UTF-8") || strstr(x, "UTF8"))
174 		rv = 1;
175 
176 	/* free copy and out */
177 	afree(x, ATEMP);
178 	return (rv);
179 }
180 
181 static int
main_init(int argc,const char * argv[],Source ** sp,struct block ** lp)182 main_init(int argc, const char *argv[], Source **sp, struct block **lp)
183 {
184 	int argi, i;
185 	Source *s = NULL;
186 	struct block *l;
187 	unsigned char restricted_shell, errexit, utf_flag;
188 	char *cp;
189 	const char *ccp, **wp;
190 	struct tbl *vp;
191 	struct stat s_stdin;
192 #if !defined(_PATH_DEFPATH) && defined(_CS_PATH)
193 	ssize_t k;
194 #endif
195 
196 	/* do things like getpgrp() et al. */
197 	chvt_reinit();
198 
199 	/* make sure argv[] is sane */
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 51 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")) {
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 = "/bin:/usr/bin:/sbin:/usr/sbin";
322 #endif
323 
324 	/*
325 	 * Set PATH to def_path (will set the path global variable).
326 	 * (import of environment below will probably change this setting).
327 	 */
328 	vp = global("PATH");
329 	/* setstr can't fail here */
330 	setstr(vp, def_path, KSH_RETURN_ERROR);
331 
332 #ifndef MKSH_NO_CMDLINE_EDITING
333 	/*
334 	 * Set edit mode to emacs by default, may be overridden
335 	 * by the environment or the user. Also, we want tab completion
336 	 * on in vi by default.
337 	 */
338 	change_flag(FEMACS, OF_SPECIAL, true);
339 #if !MKSH_S_NOVI
340 	Flag(FVITABCOMPLETE) = 1;
341 #endif
342 #endif
343 
344 	/* import environment */
345 	if (environ != NULL) {
346 		wp = (const char **)environ;
347 		while (*wp != NULL) {
348 			rndpush(*wp);
349 			typeset(*wp, IMPORT | EXPORT, 0, 0, 0);
350 			++wp;
351 		}
352 	}
353 
354 	/* for security */
355 	typeset(initifs, 0, 0, 0, 0);
356 
357 	/* assign default shell variable values */
358 	substitute(initsubs, 0);
359 
360 	/* Figure out the current working directory and set $PWD */
361 	vp = global("PWD");
362 	cp = str_val(vp);
363 	/* Try to use existing $PWD if it is valid */
364 	set_current_wd((cp[0] == '/' && test_eval(NULL, TO_FILEQ, cp, ".",
365 	    true)) ? cp : NULL);
366 	if (current_wd[0])
367 		simplify_path(current_wd);
368 	/* Only set pwd if we know where we are or if it had a bogus value */
369 	if (current_wd[0] || *cp)
370 		/* setstr can't fail here */
371 		setstr(vp, current_wd, KSH_RETURN_ERROR);
372 
373 	for (wp = initcoms; *wp != NULL; wp++) {
374 		shcomexec(wp);
375 		while (*wp != NULL)
376 			wp++;
377 	}
378 	setint_n(global("OPTIND"), 1, 10);
379 
380 	kshuid = getuid();
381 	kshgid = getgid();
382 	kshegid = getegid();
383 
384 	safe_prompt = ksheuid ? "$ " : "# ";
385 	vp = global("PS1");
386 	/* Set PS1 if unset or we are root and prompt doesn't contain a # */
387 	if (!(vp->flag & ISSET) ||
388 	    (!ksheuid && !strchr(str_val(vp), '#')))
389 		/* setstr can't fail here */
390 		setstr(vp, safe_prompt, KSH_RETURN_ERROR);
391 	setint_n((vp = global("BASHPID")), 0, 10);
392 	vp->flag |= INT_U;
393 	setint_n((vp = global("PGRP")), (mksh_uari_t)kshpgrp, 10);
394 	vp->flag |= INT_U;
395 	setint_n((vp = global("PPID")), (mksh_uari_t)kshppid, 10);
396 	vp->flag |= INT_U;
397 	setint_n((vp = global("USER_ID")), (mksh_uari_t)ksheuid, 10);
398 	vp->flag |= INT_U;
399 	setint_n((vp = global("KSHUID")), (mksh_uari_t)kshuid, 10);
400 	vp->flag |= INT_U;
401 	setint_n((vp = global("KSHEGID")), (mksh_uari_t)kshegid, 10);
402 	vp->flag |= INT_U;
403 	setint_n((vp = global("KSHGID")), (mksh_uari_t)kshgid, 10);
404 	vp->flag |= INT_U;
405 	setint_n((vp = global("RANDOM")), rndsetup(), 10);
406 	vp->flag |= INT_U;
407 	setint_n((vp_pipest = global("PIPESTATUS")), 0, 10);
408 
409 	/* Set this before parsing arguments */
410 	Flag(FPRIVILEGED) = (
411 #if HAVE_ISSETUGID
412 	    issetugid() ||
413 #endif
414 	    kshuid != ksheuid || kshgid != kshegid) ? 2 : 0;
415 
416 	/* this to note if monitor is set on command line (see below) */
417 #ifndef MKSH_UNEMPLOYED
418 	Flag(FMONITOR) = 127;
419 #endif
420 	/* this to note if utf-8 mode is set on command line (see below) */
421 	UTFMODE = 2;
422 
423 	if (!Flag(FAS_BUILTIN)) {
424 		argi = parse_args(argv, OF_CMDLINE, NULL);
425 		if (argi < 0)
426 			return (1);
427 	}
428 
429 	/* process this later only, default to off (hysterical raisins) */
430 	utf_flag = UTFMODE;
431 	UTFMODE = 0;
432 
433 	if (Flag(FAS_BUILTIN)) {
434 		/* auto-detect from environment variables, always */
435 		utf_flag = 3;
436 	} else if (Flag(FCOMMAND)) {
437 		s = pushs(SSTRINGCMDLINE, ATEMP);
438 		if (!(s->start = s->str = argv[argi++]))
439 			errorf("%s %s", "-c", "requires an argument");
440 		while (*s->str) {
441 			if (*s->str != ' ' && ctype(*s->str, C_QUOTE))
442 				break;
443 			s->str++;
444 		}
445 		if (!*s->str)
446 			s->flags |= SF_MAYEXEC;
447 		s->str = s->start;
448 #ifdef MKSH_MIDNIGHTBSD01ASH_COMPAT
449 		/* compatibility to MidnightBSD 0.1 /bin/sh (kludge) */
450 		if (Flag(FSH) && argv[argi] && !strcmp(argv[argi], "--"))
451 			++argi;
452 #endif
453 		if (argv[argi])
454 			kshname = argv[argi++];
455 	} else if (argi < argc && !Flag(FSTDIN)) {
456 		s = pushs(SFILE, ATEMP);
457 		s->file = argv[argi++];
458 		s->u.shf = shf_open(s->file, O_RDONLY, 0,
459 		    SHF_MAPHI | SHF_CLEXEC);
460 		if (s->u.shf == NULL) {
461 			shl_stdout_ok = false;
462 			warningf(true, "%s: %s", s->file, cstrerror(errno));
463 			/* mandated by SUSv4 */
464 			exstat = 127;
465 			unwind(LERROR);
466 		}
467 		kshname = s->file;
468 	} else {
469 		Flag(FSTDIN) = 1;
470 		s = pushs(SSTDIN, ATEMP);
471 		s->file = "<stdin>";
472 		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
473 		    NULL);
474 		if (isatty(0) && isatty(2)) {
475 			Flag(FTALKING) = Flag(FTALKING_I) = 1;
476 			/* The following only if isatty(0) */
477 			s->flags |= SF_TTY;
478 			s->u.shf->flags |= SHF_INTERRUPT;
479 			s->file = NULL;
480 		}
481 	}
482 
483 	/* this bizarreness is mandated by POSIX */
484 	if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
485 	    Flag(FTALKING))
486 		reset_nonblock(0);
487 
488 	/* initialise job control */
489 	j_init();
490 	/* do this after j_init() which calls tty_init_state() */
491 	if (Flag(FTALKING)) {
492 		if (utf_flag == 2) {
493 #ifndef MKSH_ASSUME_UTF8
494 			/* auto-detect from locale or environment */
495 			utf_flag = 4;
496 #else /* this may not be an #elif */
497 #if MKSH_ASSUME_UTF8
498 			utf_flag = 1;
499 #else
500 			/* always disable UTF-8 (for interactive) */
501 			utf_flag = 0;
502 #endif
503 #endif
504 		}
505 #ifndef MKSH_NO_CMDLINE_EDITING
506 		x_init();
507 #endif
508 	}
509 
510 #ifdef SIGWINCH
511 	sigtraps[SIGWINCH].flags |= TF_SHELL_USES;
512 	setsig(&sigtraps[SIGWINCH], x_sigwinch,
513 	    SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
514 #endif
515 
516 	l = e->loc;
517 	if (Flag(FAS_BUILTIN)) {
518 		l->argc = argc;
519 		l->argv = argv;
520 		l->argv[0] = ccp;
521 	} else {
522 		l->argc = argc - argi;
523 		/*
524 		 * allocate a new array because otherwise, when we modify
525 		 * it in-place, ps(1) output changes; the meaning of argc
526 		 * here is slightly different as it excludes kshname, and
527 		 * we add a trailing NULL sentinel as well
528 		 */
529 		l->argv = alloc2(l->argc + 2, sizeof(void *), APERM);
530 		l->argv[0] = kshname;
531 		memcpy(&l->argv[1], &argv[argi], l->argc * sizeof(void *));
532 		l->argv[l->argc + 1] = NULL;
533 		getopts_reset(1);
534 	}
535 
536 	/* divine the initial state of the utf8-mode Flag */
537 	ccp = null;
538 	switch (utf_flag) {
539 
540 	/* auto-detect from locale or environment */
541 	case 4:
542 #if HAVE_SETLOCALE_CTYPE
543 		ccp = setlocale(LC_CTYPE, "");
544 #if HAVE_LANGINFO_CODESET
545 		if (!isuc(ccp))
546 			ccp = nl_langinfo(CODESET);
547 #endif
548 		if (!isuc(ccp))
549 			ccp = null;
550 		/* FALLTHROUGH */
551 #endif
552 
553 	/* auto-detect from environment */
554 	case 3:
555 		/* these were imported from environ earlier */
556 		if (ccp == null)
557 			ccp = str_val(global("LC_ALL"));
558 		if (ccp == null)
559 			ccp = str_val(global("LC_CTYPE"));
560 		if (ccp == null)
561 			ccp = str_val(global("LANG"));
562 		UTFMODE = isuc(ccp);
563 		break;
564 
565 	/* not set on command line, not FTALKING */
566 	case 2:
567 	/* unknown values */
568 	default:
569 		utf_flag = 0;
570 		/* FALLTHROUGH */
571 
572 	/* known values */
573 	case 1:
574 	case 0:
575 		UTFMODE = utf_flag;
576 		break;
577 	}
578 
579 	/* Disable during .profile/ENV reading */
580 	restricted_shell = Flag(FRESTRICTED);
581 	Flag(FRESTRICTED) = 0;
582 	errexit = Flag(FERREXIT);
583 	Flag(FERREXIT) = 0;
584 
585 	/*
586 	 * Do this before profile/$ENV so that if it causes problems in them,
587 	 * user will know why things broke.
588 	 */
589 	if (!current_wd[0] && Flag(FTALKING))
590 		warningf(false, "can't determine current directory");
591 
592 	if (Flag(FLOGIN))
593 		include(MKSH_SYSTEM_PROFILE, 0, NULL, true);
594 	if (!Flag(FPRIVILEGED)) {
595 		if (Flag(FLOGIN))
596 			include(substitute("$HOME/.profile", 0), 0, NULL, true);
597 		if (Flag(FTALKING)) {
598 			cp = substitute(substitute("${ENV:-" MKSHRC_PATH "}",
599 			    0), DOTILDE);
600 			if (cp[0] != '\0')
601 				include(cp, 0, NULL, true);
602 		}
603 	} else {
604 		include(MKSH_SUID_PROFILE, 0, NULL, true);
605 		/* turn off -p if not set explicitly */
606 		if (Flag(FPRIVILEGED) != 1)
607 			change_flag(FPRIVILEGED, OF_INTERNAL, false);
608 	}
609 
610 	if (restricted_shell) {
611 		shcomexec(restr_com);
612 		/* After typeset command... */
613 		Flag(FRESTRICTED) = 1;
614 	}
615 	Flag(FERREXIT) = errexit;
616 
617 	if (Flag(FTALKING) && s)
618 		hist_init(s);
619 	else
620 		/* set after ENV */
621 		Flag(FTRACKALL) = 1;
622 
623 	alarm_init();
624 
625 	*sp = s;
626 	*lp = l;
627 	return (0);
628 }
629 
630 /* this indirection barrier reduces stack usage during normal operation */
631 
632 int
main(int argc,const char * argv[])633 main(int argc, const char *argv[])
634 {
635 	int rv;
636 	Source *s;
637 	struct block *l;
638 
639 	if ((rv = main_init(argc, argv, &s, &l)) == 0) {
640 		if (Flag(FAS_BUILTIN)) {
641 			rv = shcomexec(l->argv);
642 		} else {
643 			shell(s, true);
644 			/* NOTREACHED */
645 		}
646 	}
647 	return (rv);
648 }
649 
650 int
include(const char * name,int argc,const char ** argv,bool intr_ok)651 include(const char *name, int argc, const char **argv, bool intr_ok)
652 {
653 	Source *volatile s = NULL;
654 	struct shf *shf;
655 	const char **volatile old_argv;
656 	volatile int old_argc;
657 	int i;
658 
659 	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI | SHF_CLEXEC);
660 	if (shf == NULL)
661 		return (-1);
662 
663 	if (argv) {
664 		old_argv = e->loc->argv;
665 		old_argc = e->loc->argc;
666 	} else {
667 		old_argv = NULL;
668 		old_argc = 0;
669 	}
670 	newenv(E_INCL);
671 	if ((i = kshsetjmp(e->jbuf))) {
672 		quitenv(s ? s->u.shf : NULL);
673 		if (old_argv) {
674 			e->loc->argv = old_argv;
675 			e->loc->argc = old_argc;
676 		}
677 		switch (i) {
678 		case LRETURN:
679 		case LERROR:
680 			/* see below */
681 			return (exstat & 0xFF);
682 		case LINTR:
683 			/*
684 			 * intr_ok is set if we are including .profile or $ENV.
685 			 * If user ^Cs out, we don't want to kill the shell...
686 			 */
687 			if (intr_ok && ((exstat & 0xFF) - 128) != SIGTERM)
688 				return (1);
689 			/* FALLTHROUGH */
690 		case LEXIT:
691 		case LLEAVE:
692 		case LSHELL:
693 			unwind(i);
694 			/* NOTREACHED */
695 		default:
696 			internal_errorf("%s %d", "include", i);
697 			/* NOTREACHED */
698 		}
699 	}
700 	if (argv) {
701 		e->loc->argv = argv;
702 		e->loc->argc = argc;
703 	}
704 	s = pushs(SFILE, ATEMP);
705 	s->u.shf = shf;
706 	strdupx(s->file, name, ATEMP);
707 	i = shell(s, false);
708 	quitenv(s->u.shf);
709 	if (old_argv) {
710 		e->loc->argv = old_argv;
711 		e->loc->argc = old_argc;
712 	}
713 	/* & 0xff to ensure value not -1 */
714 	return (i & 0xFF);
715 }
716 
717 /* spawn a command into a shell optionally keeping track of the line number */
718 int
command(const char * comm,int line)719 command(const char *comm, int line)
720 {
721 	Source *s;
722 
723 	s = pushs(SSTRING, ATEMP);
724 	s->start = s->str = comm;
725 	s->line = line;
726 	return (shell(s, false));
727 }
728 
729 /*
730  * run the commands from the input source, returning status.
731  */
732 int
shell(Source * volatile s,volatile bool toplevel)733 shell(Source * volatile s, volatile bool toplevel)
734 {
735 	struct op *t;
736 	volatile bool wastty = tobool(s->flags & SF_TTY);
737 	volatile uint8_t attempts = 13;
738 	volatile bool interactive = Flag(FTALKING) && toplevel;
739 	volatile bool sfirst = true;
740 	Source *volatile old_source = source;
741 	int i;
742 
743 	newenv(E_PARSE);
744 	if (interactive)
745 		really_exit = false;
746 	switch ((i = kshsetjmp(e->jbuf))) {
747 	case 0:
748 		break;
749 	case LINTR:
750 		/* we get here if SIGINT not caught or ignored */
751 	case LERROR:
752 	case LSHELL:
753 		if (interactive) {
754 			if (i == LINTR)
755 				shellf("\n");
756 			/*
757 			 * Reset any eof that was read as part of a
758 			 * multiline command.
759 			 */
760 			if (Flag(FIGNOREEOF) && s->type == SEOF && wastty)
761 				s->type = SSTDIN;
762 			/*
763 			 * Used by exit command to get back to
764 			 * top level shell. Kind of strange since
765 			 * interactive is set if we are reading from
766 			 * a tty, but to have stopped jobs, one only
767 			 * needs FMONITOR set (not FTALKING/SF_TTY)...
768 			 */
769 			/* toss any input we have so far */
770 			yyrecursive_pop(true);
771 			s->start = s->str = null;
772 			retrace_info = NULL;
773 			herep = heres;
774 			break;
775 		}
776 		/* FALLTHROUGH */
777 	case LEXIT:
778 	case LLEAVE:
779 	case LRETURN:
780 		source = old_source;
781 		quitenv(NULL);
782 		/* keep on going */
783 		unwind(i);
784 		/* NOTREACHED */
785 	default:
786 		source = old_source;
787 		quitenv(NULL);
788 		internal_errorf("%s %d", "shell", i);
789 		/* NOTREACHED */
790 	}
791 	while (/* CONSTCOND */ 1) {
792 		if (trap)
793 			runtraps(0);
794 
795 		if (s->next == NULL) {
796 			if (Flag(FVERBOSE))
797 				s->flags |= SF_ECHO;
798 			else
799 				s->flags &= ~SF_ECHO;
800 		}
801 		if (interactive) {
802 			j_notify();
803 			set_prompt(PS1, s);
804 		}
805 		t = compile(s, sfirst);
806 		sfirst = false;
807 		if (!t)
808 			goto source_no_tree;
809 		if (t->type == TEOF) {
810 			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
811 				shellf("Use 'exit' to leave mksh\n");
812 				s->type = SSTDIN;
813 			} else if (wastty && !really_exit &&
814 			    j_stopped_running()) {
815 				really_exit = true;
816 				s->type = SSTDIN;
817 			} else {
818 				/*
819 				 * this for POSIX which says EXIT traps
820 				 * shall be taken in the environment
821 				 * immediately after the last command
822 				 * executed.
823 				 */
824 				if (toplevel)
825 					unwind(LEXIT);
826 				break;
827 			}
828 		} else if ((s->flags & SF_MAYEXEC) && t->type == TCOM)
829 			t->u.evalflags |= DOTCOMEXEC;
830 		if (!Flag(FNOEXEC) || (s->flags & SF_TTY))
831 			exstat = execute(t, 0, NULL) & 0xFF;
832 
833 		if (t->type != TEOF && interactive && really_exit)
834 			really_exit = false;
835 
836  source_no_tree:
837 		reclaim();
838 	}
839 	quitenv(NULL);
840 	source = old_source;
841 	return (exstat & 0xFF);
842 }
843 
844 /* return to closest error handler or shell(), exit if none found */
845 /* note: i MUST NOT be 0 */
846 void
unwind(int i)847 unwind(int i)
848 {
849 	/*
850 	 * This is a kludge. We need to restore everything that was
851 	 * changed in the new environment, see cid 1005090337C7A669439
852 	 * and 10050903386452ACBF1, but fail to even save things most of
853 	 * the time. funcs.c:c_eval() changes FERREXIT temporarily to 0,
854 	 * which needs to be restored thus (related to Debian #696823).
855 	 * We did not save the shell flags, so we use a special or'd
856 	 * value here... this is mostly to clean up behind *other*
857 	 * callers of unwind(LERROR) here; exec.c has the regular case.
858 	 */
859 	if (Flag(FERREXIT) & 0x80) {
860 		/* GNU bash does not run this trapsig */
861 		trapsig(ksh_SIGERR);
862 		Flag(FERREXIT) &= ~0x80;
863 	}
864 
865 	/* ordering for EXIT vs ERR is a bit odd (this is what AT&T ksh does) */
866 	if (i == LEXIT || ((i == LERROR || i == LINTR) &&
867 	    sigtraps[ksh_SIGEXIT].trap &&
868 	    (!Flag(FTALKING) || Flag(FERREXIT)))) {
869 		++trap_nested;
870 		runtrap(&sigtraps[ksh_SIGEXIT], trap_nested == 1);
871 		--trap_nested;
872 		i = LLEAVE;
873 	} else if (Flag(FERREXIT) == 1 && (i == LERROR || i == LINTR)) {
874 		++trap_nested;
875 		runtrap(&sigtraps[ksh_SIGERR], trap_nested == 1);
876 		--trap_nested;
877 		i = LLEAVE;
878 	}
879 
880 	while (/* CONSTCOND */ 1) {
881 		switch (e->type) {
882 		case E_PARSE:
883 		case E_FUNC:
884 		case E_INCL:
885 		case E_LOOP:
886 		case E_ERRH:
887 			kshlongjmp(e->jbuf, i);
888 			/* NOTREACHED */
889 		case E_NONE:
890 			if (i == LINTR)
891 				e->flags |= EF_FAKE_SIGDIE;
892 			/* FALLTHROUGH */
893 		default:
894 			quitenv(NULL);
895 		}
896 	}
897 }
898 
899 void
newenv(int type)900 newenv(int type)
901 {
902 	struct env *ep;
903 	char *cp;
904 
905 	/*
906 	 * struct env includes ALLOC_ITEM for alignment constraints
907 	 * so first get the actually used memory, then assign it
908 	 */
909 	cp = alloc(sizeof(struct env) - ALLOC_SIZE, ATEMP);
910 	/* undo what alloc() did to the malloc result address */
911 	ep = (void *)(cp - ALLOC_SIZE);
912 	/* initialise public members of struct env (not the ALLOC_ITEM) */
913 	ainit(&ep->area);
914 	ep->oenv = e;
915 	ep->loc = e->loc;
916 	ep->savefd = NULL;
917 	ep->temps = NULL;
918 	ep->yyrecursive_statep = NULL;
919 	ep->type = type;
920 	ep->flags = 0;
921 	/* jump buffer is invalid because flags == 0 */
922 	e = ep;
923 }
924 
925 void
quitenv(struct shf * shf)926 quitenv(struct shf *shf)
927 {
928 	struct env *ep = e;
929 	char *cp;
930 	int fd;
931 
932 	yyrecursive_pop(true);
933 	while (ep->oenv && ep->oenv->loc != ep->loc)
934 		popblock();
935 	if (ep->savefd != NULL) {
936 		for (fd = 0; fd < NUFILE; fd++)
937 			/* if ep->savefd[fd] < 0, means fd was closed */
938 			if (ep->savefd[fd])
939 				restfd(fd, ep->savefd[fd]);
940 		if (ep->savefd[2])
941 			/* Clear any write errors */
942 			shf_reopen(2, SHF_WR, shl_out);
943 	}
944 	/*
945 	 * Bottom of the stack.
946 	 * Either main shell is exiting or cleanup_parents_env() was called.
947 	 */
948 	if (ep->oenv == NULL) {
949 #ifdef DEBUG_LEAKS
950 		int i;
951 #endif
952 
953 		if (ep->type == E_NONE) {
954 			/* Main shell exiting? */
955 #if HAVE_PERSISTENT_HISTORY
956 			if (Flag(FTALKING))
957 				hist_finish();
958 #endif
959 			j_exit();
960 			if (ep->flags & EF_FAKE_SIGDIE) {
961 				int sig = (exstat & 0xFF) - 128;
962 
963 				/*
964 				 * ham up our death a bit (AT&T ksh
965 				 * only seems to do this for SIGTERM)
966 				 * Don't do it for SIGQUIT, since we'd
967 				 * dump a core..
968 				 */
969 				if ((sig == SIGINT || sig == SIGTERM) &&
970 				    (kshpgrp == kshpid)) {
971 					setsig(&sigtraps[sig], SIG_DFL,
972 					    SS_RESTORE_CURR | SS_FORCE);
973 					kill(0, sig);
974 				}
975 			}
976 		}
977 		if (shf)
978 			shf_close(shf);
979 		reclaim();
980 #ifdef DEBUG_LEAKS
981 #ifndef MKSH_NO_CMDLINE_EDITING
982 		x_done();
983 #endif
984 #ifndef MKSH_NOPROSPECTOFWORK
985 		/* block at least SIGCHLD during/after afreeall */
986 		sigprocmask(SIG_BLOCK, &sm_sigchld, NULL);
987 #endif
988 		afreeall(APERM);
989 		for (fd = 3; fd < NUFILE; fd++)
990 			if ((i = fcntl(fd, F_GETFD, 0)) != -1 &&
991 			    (i & FD_CLOEXEC))
992 				close(fd);
993 		close(2);
994 		close(1);
995 		close(0);
996 #endif
997 		exit(exstat & 0xFF);
998 	}
999 	if (shf)
1000 		shf_close(shf);
1001 	reclaim();
1002 
1003 	e = e->oenv;
1004 
1005 	/* free the struct env - tricky due to the ALLOC_ITEM inside */
1006 	cp = (void *)ep;
1007 	afree(cp + ALLOC_SIZE, ATEMP);
1008 }
1009 
1010 /* Called after a fork to cleanup stuff left over from parents environment */
1011 void
cleanup_parents_env(void)1012 cleanup_parents_env(void)
1013 {
1014 	struct env *ep;
1015 	int fd;
1016 
1017 	mkssert(e != NULL);
1018 
1019 	/*
1020 	 * Don't clean up temporary files - parent will probably need them.
1021 	 * Also, can't easily reclaim memory since variables, etc. could be
1022 	 * anywhere.
1023 	 */
1024 
1025 	/* close all file descriptors hiding in savefd */
1026 	for (ep = e; ep; ep = ep->oenv) {
1027 		if (ep->savefd) {
1028 			for (fd = 0; fd < NUFILE; fd++)
1029 				if (ep->savefd[fd] > 0)
1030 					close(ep->savefd[fd]);
1031 			afree(ep->savefd, &ep->area);
1032 			ep->savefd = NULL;
1033 		}
1034 #ifdef DEBUG_LEAKS
1035 		if (ep->type != E_NONE)
1036 			ep->type = E_GONE;
1037 #endif
1038 	}
1039 #ifndef DEBUG_LEAKS
1040 	e->oenv = NULL;
1041 #endif
1042 }
1043 
1044 /* Called just before an execve cleanup stuff temporary files */
1045 void
cleanup_proc_env(void)1046 cleanup_proc_env(void)
1047 {
1048 	struct env *ep;
1049 
1050 	for (ep = e; ep; ep = ep->oenv)
1051 		remove_temps(ep->temps);
1052 }
1053 
1054 /* remove temp files and free ATEMP Area */
1055 static void
reclaim(void)1056 reclaim(void)
1057 {
1058 	struct block *l;
1059 
1060 	while ((l = e->loc) && (!e->oenv || e->oenv->loc != l)) {
1061 		e->loc = l->next;
1062 		afreeall(&l->area);
1063 	}
1064 
1065 	remove_temps(e->temps);
1066 	e->temps = NULL;
1067 	afreeall(&e->area);
1068 }
1069 
1070 static void
remove_temps(struct temp * tp)1071 remove_temps(struct temp *tp)
1072 {
1073 	for (; tp != NULL; tp = tp->next)
1074 		if (tp->pid == procpid)
1075 			unlink(tp->tffn);
1076 }
1077 
1078 /*
1079  * Initialise tty_fd. Used for tracking the size of the terminal,
1080  * saving/resetting tty modes upon forground job completion, and
1081  * for setting up the tty process group. Return values:
1082  *	0 = got controlling tty
1083  *	1 = got terminal but no controlling tty
1084  *	2 = cannot find a terminal
1085  *	3 = cannot dup fd
1086  *	4 = cannot make fd close-on-exec
1087  * An existing tty_fd is cached if no "better" one could be found,
1088  * i.e. if tty_devtty was already set or the new would not set it.
1089  */
1090 int
tty_init_fd(void)1091 tty_init_fd(void)
1092 {
1093 	int fd, rv, eno = 0;
1094 	bool do_close = false, is_devtty = true;
1095 
1096 	if (tty_devtty) {
1097 		/* already got a tty which is /dev/tty */
1098 		return (0);
1099 	}
1100 
1101 #ifdef _UWIN
1102 	/*XXX imake style */
1103 	if (isatty(3)) {
1104 		/* fd 3 on UWIN _is_ /dev/tty (or our controlling tty) */
1105 		fd = 3;
1106 		goto got_fd;
1107 	}
1108 #endif
1109 	if ((fd = open("/dev/tty", O_RDWR, 0)) >= 0) {
1110 		do_close = true;
1111 		goto got_fd;
1112 	}
1113 	eno = errno;
1114 
1115 	if (tty_fd >= 0) {
1116 		/* already got a non-devtty one */
1117 		rv = 1;
1118 		goto out;
1119 	}
1120 	is_devtty = false;
1121 
1122 	if (isatty((fd = 0)) || isatty((fd = 2)))
1123 		goto got_fd;
1124 	/* cannot find one */
1125 	rv = 2;
1126 	/* assert: do_close == false */
1127 	goto out;
1128 
1129  got_fd:
1130 	if ((rv = fcntl(fd, F_DUPFD, FDBASE)) < 0) {
1131 		eno = errno;
1132 		rv = 3;
1133 		goto out;
1134 	}
1135 	if (fcntl(rv, F_SETFD, FD_CLOEXEC) < 0) {
1136 		eno = errno;
1137 		close(rv);
1138 		rv = 4;
1139 		goto out;
1140 	}
1141 	tty_fd = rv;
1142 	tty_devtty = is_devtty;
1143 	rv = eno = 0;
1144  out:
1145 	if (do_close)
1146 		close(fd);
1147 	errno = eno;
1148 	return (rv);
1149 }
1150 
1151 /* A shell error occurred (eg, syntax error, etc.) */
1152 
1153 #define VWARNINGF_ERRORPREFIX	1
1154 #define VWARNINGF_FILELINE	2
1155 #define VWARNINGF_BUILTIN	4
1156 #define VWARNINGF_INTERNAL	8
1157 
1158 static void vwarningf(unsigned int, const char *, va_list)
1159     MKSH_A_FORMAT(__printf__, 2, 0);
1160 
1161 static void
vwarningf(unsigned int flags,const char * fmt,va_list ap)1162 vwarningf(unsigned int flags, const char *fmt, va_list ap)
1163 {
1164 	if (fmt) {
1165 		if (flags & VWARNINGF_INTERNAL)
1166 			shf_fprintf(shl_out, "internal error: ");
1167 		if (flags & VWARNINGF_ERRORPREFIX)
1168 			error_prefix(tobool(flags & VWARNINGF_FILELINE));
1169 		if ((flags & VWARNINGF_BUILTIN) &&
1170 		    /* not set when main() calls parse_args() */
1171 		    builtin_argv0 && builtin_argv0 != kshname)
1172 			shf_fprintf(shl_out, "%s: ", builtin_argv0);
1173 		shf_vfprintf(shl_out, fmt, ap);
1174 		shf_putchar('\n', shl_out);
1175 	}
1176 	shf_flush(shl_out);
1177 }
1178 
1179 void
errorfx(int rc,const char * fmt,...)1180 errorfx(int rc, const char *fmt, ...)
1181 {
1182 	va_list va;
1183 
1184 	exstat = rc;
1185 
1186 	/* debugging: note that stdout not valid */
1187 	shl_stdout_ok = false;
1188 
1189 	va_start(va, fmt);
1190 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1191 	va_end(va);
1192 	unwind(LERROR);
1193 }
1194 
1195 void
errorf(const char * fmt,...)1196 errorf(const char *fmt, ...)
1197 {
1198 	va_list va;
1199 
1200 	exstat = 1;
1201 
1202 	/* debugging: note that stdout not valid */
1203 	shl_stdout_ok = false;
1204 
1205 	va_start(va, fmt);
1206 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1207 	va_end(va);
1208 	unwind(LERROR);
1209 }
1210 
1211 /* like errorf(), but no unwind is done */
1212 void
warningf(bool fileline,const char * fmt,...)1213 warningf(bool fileline, const char *fmt, ...)
1214 {
1215 	va_list va;
1216 
1217 	va_start(va, fmt);
1218 	vwarningf(VWARNINGF_ERRORPREFIX | (fileline ? VWARNINGF_FILELINE : 0),
1219 	    fmt, va);
1220 	va_end(va);
1221 }
1222 
1223 /*
1224  * Used by built-in utilities to prefix shell and utility name to message
1225  * (also unwinds environments for special builtins).
1226  */
1227 void
bi_errorf(const char * fmt,...)1228 bi_errorf(const char *fmt, ...)
1229 {
1230 	va_list va;
1231 
1232 	/* debugging: note that stdout not valid */
1233 	shl_stdout_ok = false;
1234 
1235 	exstat = 1;
1236 
1237 	va_start(va, fmt);
1238 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE |
1239 	    VWARNINGF_BUILTIN, fmt, va);
1240 	va_end(va);
1241 
1242 	/*
1243 	 * POSIX special builtins and ksh special builtins cause
1244 	 * non-interactive shells to exit.
1245 	 * XXX odd use of KEEPASN; also may not want LERROR here
1246 	 */
1247 	if (builtin_flag & SPEC_BI) {
1248 		builtin_argv0 = NULL;
1249 		unwind(LERROR);
1250 	}
1251 }
1252 
1253 /* Called when something that shouldn't happen does */
1254 void
internal_errorf(const char * fmt,...)1255 internal_errorf(const char *fmt, ...)
1256 {
1257 	va_list va;
1258 
1259 	va_start(va, fmt);
1260 	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1261 	va_end(va);
1262 	unwind(LERROR);
1263 }
1264 
1265 void
internal_warningf(const char * fmt,...)1266 internal_warningf(const char *fmt, ...)
1267 {
1268 	va_list va;
1269 
1270 	va_start(va, fmt);
1271 	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1272 	va_end(va);
1273 }
1274 
1275 /* used by error reporting functions to print "ksh: .kshrc[25]: " */
1276 void
error_prefix(bool fileline)1277 error_prefix(bool fileline)
1278 {
1279 	/* Avoid foo: foo[2]: ... */
1280 	if (!fileline || !source || !source->file ||
1281 	    strcmp(source->file, kshname) != 0)
1282 		shf_fprintf(shl_out, "%s: ", kshname + (*kshname == '-'));
1283 	if (fileline && source && source->file != NULL) {
1284 		shf_fprintf(shl_out, "%s[%d]: ", source->file,
1285 		    source->errline > 0 ? source->errline : source->line);
1286 		source->errline = 0;
1287 	}
1288 }
1289 
1290 /* printf to shl_out (stderr) with flush */
1291 void
shellf(const char * fmt,...)1292 shellf(const char *fmt, ...)
1293 {
1294 	va_list va;
1295 
1296 	if (!initio_done)
1297 		/* shl_out may not be set up yet... */
1298 		return;
1299 	va_start(va, fmt);
1300 	shf_vfprintf(shl_out, fmt, va);
1301 	va_end(va);
1302 	shf_flush(shl_out);
1303 }
1304 
1305 /* printf to shl_stdout (stdout) */
1306 void
shprintf(const char * fmt,...)1307 shprintf(const char *fmt, ...)
1308 {
1309 	va_list va;
1310 
1311 	if (!shl_stdout_ok)
1312 		internal_errorf("shl_stdout not valid");
1313 	va_start(va, fmt);
1314 	shf_vfprintf(shl_stdout, fmt, va);
1315 	va_end(va);
1316 }
1317 
1318 /* test if we can seek backwards fd (returns 0 or SHF_UNBUF) */
1319 int
can_seek(int fd)1320 can_seek(int fd)
1321 {
1322 	struct stat statb;
1323 
1324 	return (fstat(fd, &statb) == 0 && !S_ISREG(statb.st_mode) ?
1325 	    SHF_UNBUF : 0);
1326 }
1327 
1328 #ifdef DF
1329 int shl_dbg_fd;
1330 #define NSHF_IOB 4
1331 #else
1332 #define NSHF_IOB 3
1333 #endif
1334 struct shf shf_iob[NSHF_IOB];
1335 
1336 void
initio(void)1337 initio(void)
1338 {
1339 #ifdef DF
1340 	const char *lfp;
1341 #endif
1342 
1343 	/* force buffer allocation */
1344 	shf_fdopen(1, SHF_WR, shl_stdout);
1345 	shf_fdopen(2, SHF_WR, shl_out);
1346 	shf_fdopen(2, SHF_WR, shl_xtrace);
1347 #ifdef DF
1348 	if ((lfp = getenv("SDMKSH_PATH")) == NULL) {
1349 		if ((lfp = getenv("HOME")) == NULL || *lfp != '/')
1350 			errorf("cannot get home directory");
1351 		lfp = shf_smprintf("%s/mksh-dbg.txt", lfp);
1352 	}
1353 
1354 	if ((shl_dbg_fd = open(lfp, O_WRONLY | O_APPEND | O_CREAT, 0600)) < 0)
1355 		errorf("cannot open debug output file %s", lfp);
1356 	if (shl_dbg_fd < FDBASE) {
1357 		int nfd;
1358 
1359 		nfd = fcntl(shl_dbg_fd, F_DUPFD, FDBASE);
1360 		close(shl_dbg_fd);
1361 		if ((shl_dbg_fd = nfd) == -1)
1362 			errorf("cannot dup debug output file");
1363 	}
1364 	fcntl(shl_dbg_fd, F_SETFD, FD_CLOEXEC);
1365 	shf_fdopen(shl_dbg_fd, SHF_WR, shl_dbg);
1366 	DF("=== open ===");
1367 #endif
1368 	initio_done = true;
1369 }
1370 
1371 /* A dup2() with error checking */
1372 int
ksh_dup2(int ofd,int nfd,bool errok)1373 ksh_dup2(int ofd, int nfd, bool errok)
1374 {
1375 	int rv;
1376 
1377 	if (((rv = dup2(ofd, nfd)) < 0) && !errok && (errno != EBADF))
1378 		errorf("too many files open in shell");
1379 
1380 #ifdef __ultrix
1381 	/*XXX imake style */
1382 	if (rv >= 0)
1383 		fcntl(nfd, F_SETFD, 0);
1384 #endif
1385 
1386 	return (rv);
1387 }
1388 
1389 /*
1390  * Move fd from user space (0 <= fd < 10) to shell space (fd >= 10),
1391  * set close-on-exec flag. See FDBASE in sh.h, maybe 24 not 10 here.
1392  */
1393 short
savefd(int fd)1394 savefd(int fd)
1395 {
1396 	int nfd = fd;
1397 
1398 	if (fd < FDBASE && (nfd = fcntl(fd, F_DUPFD, FDBASE)) < 0 &&
1399 	    errno == EBADF)
1400 		return (-1);
1401 	if (nfd < 0 || nfd > SHRT_MAX)
1402 		errorf("too many files open in shell");
1403 	fcntl(nfd, F_SETFD, FD_CLOEXEC);
1404 	return ((short)nfd);
1405 }
1406 
1407 void
restfd(int fd,int ofd)1408 restfd(int fd, int ofd)
1409 {
1410 	if (fd == 2)
1411 		shf_flush(&shf_iob[/* fd */ 2]);
1412 	if (ofd < 0)
1413 		/* original fd closed */
1414 		close(fd);
1415 	else if (fd != ofd) {
1416 		/*XXX: what to do if this dup fails? */
1417 		ksh_dup2(ofd, fd, true);
1418 		close(ofd);
1419 	}
1420 }
1421 
1422 void
openpipe(int * pv)1423 openpipe(int *pv)
1424 {
1425 	int lpv[2];
1426 
1427 	if (pipe(lpv) < 0)
1428 		errorf("can't create pipe - try again");
1429 	pv[0] = savefd(lpv[0]);
1430 	if (pv[0] != lpv[0])
1431 		close(lpv[0]);
1432 	pv[1] = savefd(lpv[1]);
1433 	if (pv[1] != lpv[1])
1434 		close(lpv[1]);
1435 }
1436 
1437 void
closepipe(int * pv)1438 closepipe(int *pv)
1439 {
1440 	close(pv[0]);
1441 	close(pv[1]);
1442 }
1443 
1444 /*
1445  * Called by iosetup() (deals with 2>&4, etc.), c_read, c_print to turn
1446  * a string (the X in 2>&X, read -uX, print -uX) into a file descriptor.
1447  */
1448 int
check_fd(const char * name,int mode,const char ** emsgp)1449 check_fd(const char *name, int mode, const char **emsgp)
1450 {
1451 	int fd, fl;
1452 
1453 	if (name[0] == 'p' && !name[1])
1454 		return (coproc_getfd(mode, emsgp));
1455 	for (fd = 0; ksh_isdigit(*name); ++name)
1456 		fd = (fd * 10) + *name - '0';
1457 	if (*name || fd >= FDBASE) {
1458 		if (emsgp)
1459 			*emsgp = "illegal file descriptor name";
1460 		return (-1);
1461 	}
1462 	if ((fl = fcntl(fd, F_GETFL, 0)) < 0) {
1463 		if (emsgp)
1464 			*emsgp = "bad file descriptor";
1465 		return (-1);
1466 	}
1467 	fl &= O_ACCMODE;
1468 	/*
1469 	 * X_OK is a kludge to disable this check for dups (x<&1):
1470 	 * historical shells never did this check (XXX don't know what
1471 	 * POSIX has to say).
1472 	 */
1473 	if (!(mode & X_OK) && fl != O_RDWR && (
1474 	    ((mode & R_OK) && fl != O_RDONLY) ||
1475 	    ((mode & W_OK) && fl != O_WRONLY))) {
1476 		if (emsgp)
1477 			*emsgp = (fl == O_WRONLY) ?
1478 			    "fd not open for reading" :
1479 			    "fd not open for writing";
1480 		return (-1);
1481 	}
1482 	return (fd);
1483 }
1484 
1485 /* Called once from main */
1486 void
coproc_init(void)1487 coproc_init(void)
1488 {
1489 	coproc.read = coproc.readw = coproc.write = -1;
1490 	coproc.njobs = 0;
1491 	coproc.id = 0;
1492 }
1493 
1494 /* Called by c_read() when eof is read - close fd if it is the co-process fd */
1495 void
coproc_read_close(int fd)1496 coproc_read_close(int fd)
1497 {
1498 	if (coproc.read >= 0 && fd == coproc.read) {
1499 		coproc_readw_close(fd);
1500 		close(coproc.read);
1501 		coproc.read = -1;
1502 	}
1503 }
1504 
1505 /*
1506  * Called by c_read() and by iosetup() to close the other side of the
1507  * read pipe, so reads will actually terminate.
1508  */
1509 void
coproc_readw_close(int fd)1510 coproc_readw_close(int fd)
1511 {
1512 	if (coproc.readw >= 0 && coproc.read >= 0 && fd == coproc.read) {
1513 		close(coproc.readw);
1514 		coproc.readw = -1;
1515 	}
1516 }
1517 
1518 /*
1519  * Called by c_print when a write to a fd fails with EPIPE and by iosetup
1520  * when co-process input is dup'd
1521  */
1522 void
coproc_write_close(int fd)1523 coproc_write_close(int fd)
1524 {
1525 	if (coproc.write >= 0 && fd == coproc.write) {
1526 		close(coproc.write);
1527 		coproc.write = -1;
1528 	}
1529 }
1530 
1531 /*
1532  * Called to check for existence of/value of the co-process file descriptor.
1533  * (Used by check_fd() and by c_read/c_print to deal with -p option).
1534  */
1535 int
coproc_getfd(int mode,const char ** emsgp)1536 coproc_getfd(int mode, const char **emsgp)
1537 {
1538 	int fd = (mode & R_OK) ? coproc.read : coproc.write;
1539 
1540 	if (fd >= 0)
1541 		return (fd);
1542 	if (emsgp)
1543 		*emsgp = "no coprocess";
1544 	return (-1);
1545 }
1546 
1547 /*
1548  * called to close file descriptors related to the coprocess (if any)
1549  * Should be called with SIGCHLD blocked.
1550  */
1551 void
coproc_cleanup(int reuse)1552 coproc_cleanup(int reuse)
1553 {
1554 	/* This to allow co-processes to share output pipe */
1555 	if (!reuse || coproc.readw < 0 || coproc.read < 0) {
1556 		if (coproc.read >= 0) {
1557 			close(coproc.read);
1558 			coproc.read = -1;
1559 		}
1560 		if (coproc.readw >= 0) {
1561 			close(coproc.readw);
1562 			coproc.readw = -1;
1563 		}
1564 	}
1565 	if (coproc.write >= 0) {
1566 		close(coproc.write);
1567 		coproc.write = -1;
1568 	}
1569 }
1570 
1571 struct temp *
maketemp(Area * ap,Temp_type type,struct temp ** tlist)1572 maketemp(Area *ap, Temp_type type, struct temp **tlist)
1573 {
1574 	char *cp;
1575 	size_t len;
1576 	int i, j;
1577 	struct temp *tp;
1578 	const char *dir;
1579 	struct stat sb;
1580 
1581 	dir = tmpdir ? tmpdir : MKSH_DEFAULT_TMPDIR;
1582 	/* add "/shXXXXXX.tmp" plus NUL */
1583 	len = strlen(dir);
1584 	checkoktoadd(len, offsetof(struct temp, tffn[0]) + 14);
1585 	tp = alloc(offsetof(struct temp, tffn[0]) + 14 + len, ap);
1586 
1587 	tp->shf = NULL;
1588 	tp->pid = procpid;
1589 	tp->type = type;
1590 
1591 	if (stat(dir, &sb) || !S_ISDIR(sb.st_mode)) {
1592 		tp->tffn[0] = '\0';
1593 		goto maketemp_out;
1594 	}
1595 
1596 	cp = (void *)tp;
1597 	cp += offsetof(struct temp, tffn[0]);
1598 	memcpy(cp, dir, len);
1599 	cp += len;
1600 	memcpy(cp, "/shXXXXXX.tmp", 14);
1601 	/* point to the first of six Xes */
1602 	cp += 3;
1603 	/* generate random part of filename */
1604 	len = -1;
1605 	do {
1606 		i = rndget() % 36;
1607 		cp[++len] = i < 26 ? 'a' + i : '0' + i - 26;
1608 	} while (len < 5);
1609 
1610 	/* cyclically attempt to open a temporary file */
1611 	while ((i = open(tp->tffn, O_CREAT | O_EXCL | O_RDWR | O_BINARY,
1612 	    0600)) < 0) {
1613 		if (errno != EEXIST)
1614 			goto maketemp_out;
1615 		/* count down from z to a then from 9 to 0 */
1616 		while (cp[len] == '0')
1617 			if (!len--)
1618 				goto maketemp_out;
1619 		if (cp[len] == 'a')
1620 			cp[len] = '9';
1621 		else
1622 			--cp[len];
1623 		/* do another cycle */
1624 	}
1625 
1626 	if (type == TT_FUNSUB) {
1627 		/* map us high and mark as close-on-exec */
1628 		if ((j = savefd(i)) != i) {
1629 			close(i);
1630 			i = j;
1631 		}
1632 
1633 		/* operation mode for the shf */
1634 		j = SHF_RD;
1635 	} else
1636 		j = SHF_WR;
1637 
1638 	/* shf_fdopen cannot fail, so no fd leak */
1639 	tp->shf = shf_fdopen(i, j, NULL);
1640 
1641  maketemp_out:
1642 	tp->next = *tlist;
1643 	*tlist = tp;
1644 	return (tp);
1645 }
1646 
1647 /*
1648  * We use a similar collision resolution algorithm as Python 2.5.4
1649  * but with a slightly tweaked implementation written from scratch.
1650  */
1651 
1652 #define	INIT_TBLSHIFT	3	/* initial table shift (2^3 = 8) */
1653 #define PERTURB_SHIFT	5	/* see Python 2.5.4 Objects/dictobject.c */
1654 
1655 static void tgrow(struct table *);
1656 static int tnamecmp(const void *, const void *);
1657 
1658 static void
tgrow(struct table * tp)1659 tgrow(struct table *tp)
1660 {
1661 	size_t i, j, osize, mask, perturb;
1662 	struct tbl *tblp, **pp;
1663 	struct tbl **ntblp, **otblp = tp->tbls;
1664 
1665 	if (tp->tshift > 29)
1666 		internal_errorf("hash table size limit reached");
1667 
1668 	/* calculate old size, new shift and new size */
1669 	osize = (size_t)1 << (tp->tshift++);
1670 	i = osize << 1;
1671 
1672 	ntblp = alloc2(i, sizeof(struct tbl *), tp->areap);
1673 	/* multiplication cannot overflow: alloc2 checked that */
1674 	memset(ntblp, 0, i * sizeof(struct tbl *));
1675 
1676 	/* table can get very full when reaching its size limit */
1677 	tp->nfree = (tp->tshift == 30) ? 0x3FFF0000UL :
1678 	    /* but otherwise, only 75% */
1679 	    ((i * 3) / 4);
1680 	tp->tbls = ntblp;
1681 	if (otblp == NULL)
1682 		return;
1683 
1684 	mask = i - 1;
1685 	for (i = 0; i < osize; i++)
1686 		if ((tblp = otblp[i]) != NULL) {
1687 			if ((tblp->flag & DEFINED)) {
1688 				/* search for free hash table slot */
1689 				j = perturb = tblp->ua.hval;
1690 				goto find_first_empty_slot;
1691  find_next_empty_slot:
1692 				j = (j << 2) + j + perturb + 1;
1693 				perturb >>= PERTURB_SHIFT;
1694  find_first_empty_slot:
1695 				pp = &ntblp[j & mask];
1696 				if (*pp != NULL)
1697 					goto find_next_empty_slot;
1698 				/* found an empty hash table slot */
1699 				*pp = tblp;
1700 				tp->nfree--;
1701 			} else if (!(tblp->flag & FINUSE)) {
1702 				afree(tblp, tp->areap);
1703 			}
1704 		}
1705 	afree(otblp, tp->areap);
1706 }
1707 
1708 void
ktinit(Area * ap,struct table * tp,uint8_t initshift)1709 ktinit(Area *ap, struct table *tp, uint8_t initshift)
1710 {
1711 	tp->areap = ap;
1712 	tp->tbls = NULL;
1713 	tp->tshift = ((initshift > INIT_TBLSHIFT) ?
1714 	    initshift : INIT_TBLSHIFT) - 1;
1715 	tgrow(tp);
1716 }
1717 
1718 /* table, name (key) to search for, hash(name), rv pointer to tbl ptr */
1719 struct tbl *
ktscan(struct table * tp,const char * name,uint32_t h,struct tbl *** ppp)1720 ktscan(struct table *tp, const char *name, uint32_t h, struct tbl ***ppp)
1721 {
1722 	size_t j, perturb, mask;
1723 	struct tbl **pp, *p;
1724 
1725 	mask = ((size_t)1 << (tp->tshift)) - 1;
1726 	/* search for hash table slot matching name */
1727 	j = perturb = h;
1728 	goto find_first_slot;
1729  find_next_slot:
1730 	j = (j << 2) + j + perturb + 1;
1731 	perturb >>= PERTURB_SHIFT;
1732  find_first_slot:
1733 	pp = &tp->tbls[j & mask];
1734 	if ((p = *pp) != NULL && (p->ua.hval != h || !(p->flag & DEFINED) ||
1735 	    strcmp(p->name, name)))
1736 		goto find_next_slot;
1737 	/* p == NULL if not found, correct found entry otherwise */
1738 	if (ppp)
1739 		*ppp = pp;
1740 	return (p);
1741 }
1742 
1743 /* table, name (key) to enter, hash(n) */
1744 struct tbl *
ktenter(struct table * tp,const char * n,uint32_t h)1745 ktenter(struct table *tp, const char *n, uint32_t h)
1746 {
1747 	struct tbl **pp, *p;
1748 	size_t len;
1749 
1750  Search:
1751 	if ((p = ktscan(tp, n, h, &pp)))
1752 		return (p);
1753 
1754 	if (tp->nfree == 0) {
1755 		/* too full */
1756 		tgrow(tp);
1757 		goto Search;
1758 	}
1759 
1760 	/* create new tbl entry */
1761 	len = strlen(n);
1762 	checkoktoadd(len, offsetof(struct tbl, name[0]) + 1);
1763 	p = alloc(offsetof(struct tbl, name[0]) + ++len, tp->areap);
1764 	p->flag = 0;
1765 	p->type = 0;
1766 	p->areap = tp->areap;
1767 	p->ua.hval = h;
1768 	p->u2.field = 0;
1769 	p->u.array = NULL;
1770 	memcpy(p->name, n, len);
1771 
1772 	/* enter in tp->tbls */
1773 	tp->nfree--;
1774 	*pp = p;
1775 	return (p);
1776 }
1777 
1778 void
ktwalk(struct tstate * ts,struct table * tp)1779 ktwalk(struct tstate *ts, struct table *tp)
1780 {
1781 	ts->left = (size_t)1 << (tp->tshift);
1782 	ts->next = tp->tbls;
1783 }
1784 
1785 struct tbl *
ktnext(struct tstate * ts)1786 ktnext(struct tstate *ts)
1787 {
1788 	while (--ts->left >= 0) {
1789 		struct tbl *p = *ts->next++;
1790 		if (p != NULL && (p->flag & DEFINED))
1791 			return (p);
1792 	}
1793 	return (NULL);
1794 }
1795 
1796 static int
tnamecmp(const void * p1,const void * p2)1797 tnamecmp(const void *p1, const void *p2)
1798 {
1799 	const struct tbl *a = *((const struct tbl * const *)p1);
1800 	const struct tbl *b = *((const struct tbl * const *)p2);
1801 
1802 	return (strcmp(a->name, b->name));
1803 }
1804 
1805 struct tbl **
ktsort(struct table * tp)1806 ktsort(struct table *tp)
1807 {
1808 	size_t i;
1809 	struct tbl **p, **sp, **dp;
1810 
1811 	/*
1812 	 * since the table is never entirely full, no need to reserve
1813 	 * additional space for the trailing NULL appended below
1814 	 */
1815 	i = (size_t)1 << (tp->tshift);
1816 	p = alloc2(i, sizeof(struct tbl *), ATEMP);
1817 	sp = tp->tbls;		/* source */
1818 	dp = p;			/* dest */
1819 	while (i--)
1820 		if ((*dp = *sp++) != NULL && (((*dp)->flag & DEFINED) ||
1821 		    ((*dp)->flag & ARRAY)))
1822 			dp++;
1823 	qsort(p, (i = dp - p), sizeof(struct tbl *), tnamecmp);
1824 	p[i] = NULL;
1825 	return (p);
1826 }
1827 
1828 #ifdef SIGWINCH
1829 static void
x_sigwinch(int sig MKSH_A_UNUSED)1830 x_sigwinch(int sig MKSH_A_UNUSED)
1831 {
1832 	/* this runs inside interrupt context, with errno saved */
1833 
1834 	got_winch = 1;
1835 }
1836 #endif
1837 
1838 #ifdef DF
1839 void
DF(const char * fmt,...)1840 DF(const char *fmt, ...)
1841 {
1842 	va_list args;
1843 	struct timeval tv;
1844 	mirtime_mjd mjd;
1845 
1846 	mksh_lockfd(shl_dbg_fd);
1847 	mksh_TIME(tv);
1848 	timet2mjd(&mjd, tv.tv_sec);
1849 	shf_fprintf(shl_dbg, "[%02u:%02u:%02u (%u) %u.%06u] ",
1850 	    (unsigned)mjd.sec / 3600, ((unsigned)mjd.sec / 60) % 60,
1851 	    (unsigned)mjd.sec % 60, (unsigned)getpid(),
1852 	    (unsigned)tv.tv_sec, (unsigned)tv.tv_usec);
1853 	va_start(args, fmt);
1854 	shf_vfprintf(shl_dbg, fmt, args);
1855 	va_end(args);
1856 	shf_putc('\n', shl_dbg);
1857 	shf_flush(shl_dbg);
1858 	mksh_unlkfd(shl_dbg_fd);
1859 }
1860 #endif
1861 
1862 void
x_mkraw(int fd,mksh_ttyst * ocb,bool forread)1863 x_mkraw(int fd, mksh_ttyst *ocb, bool forread)
1864 {
1865 	mksh_ttyst cb;
1866 
1867 	if (ocb)
1868 		mksh_tcget(fd, ocb);
1869 	else
1870 		ocb = &tty_state;
1871 
1872 	cb = *ocb;
1873 	if (forread) {
1874 		cb.c_iflag &= ~(ISTRIP);
1875 		cb.c_lflag &= ~(ICANON) | ECHO;
1876 	} else {
1877 		cb.c_iflag &= ~(INLCR | ICRNL | ISTRIP);
1878 		cb.c_lflag &= ~(ISIG | ICANON | ECHO);
1879 	}
1880 #if defined(VLNEXT) && defined(_POSIX_VDISABLE)
1881 	/* OSF/1 processes lnext when ~icanon */
1882 	cb.c_cc[VLNEXT] = _POSIX_VDISABLE;
1883 #endif
1884 	/* SunOS 4.1.x & OSF/1 processes discard(flush) when ~icanon */
1885 #if defined(VDISCARD) && defined(_POSIX_VDISABLE)
1886 	cb.c_cc[VDISCARD] = _POSIX_VDISABLE;
1887 #endif
1888 	cb.c_cc[VTIME] = 0;
1889 	cb.c_cc[VMIN] = 1;
1890 
1891 	mksh_tcset(fd, &cb);
1892 }
1893