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1 /*	$OpenBSD: main.c,v 1.52 2013/06/15 17:25:19 millert Exp $	*/
2 /*	$OpenBSD: tty.c,v 1.9 2006/03/14 22:08:01 deraadt Exp $	*/
3 /*	$OpenBSD: io.c,v 1.22 2006/03/17 16:30:13 millert 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
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 1.269 2013/07/25 18:07:46 tg Exp $");
38 
39 extern char **environ;
40 
41 #ifndef MKSHRC_PATH
42 #define MKSHRC_PATH	"~/.mkshrc"
43 #endif
44 
45 #ifndef MKSH_DEFAULT_TMPDIR
46 #define MKSH_DEFAULT_TMPDIR	"/tmp"
47 #endif
48 
49 static uint8_t isuc(const char *);
50 static int main_init(int, const char *[], Source **, struct block **);
51 uint32_t chvt_rndsetup(const void *, size_t);
52 void chvt_reinit(void);
53 static void reclaim(void);
54 static void remove_temps(struct temp *);
55 static mksh_uari_t rndsetup(void);
56 #ifdef SIGWINCH
57 static void x_sigwinch(int);
58 #endif
59 
60 static const char initifs[] = "IFS= \t\n";
61 
62 static const char initsubs[] =
63     "${PS2=> } ${PS3=#? } ${PS4=+ } ${SECONDS=0} ${TMOUT=0} ${EPOCHREALTIME=}";
64 
65 static const char *initcoms[] = {
66 	Ttypeset, "-r", initvsn, NULL,
67 	Ttypeset, "-x", "HOME", "PATH", "RANDOM", "SHELL", NULL,
68 	Ttypeset, "-i10", "COLUMNS", "LINES", "SECONDS", "TMOUT", NULL,
69 	Talias,
70 	"integer=typeset -i",
71 	Tlocal_typeset,
72 	/* not "alias -t --": hash -r needs to work */
73 	"hash=alias -t",
74 	"type=whence -v",
75 #if !defined(ANDROID) && !defined(MKSH_UNEMPLOYED)
76 	/* not in Android for political reasons */
77 	/* not in ARGE mksh due to no job control */
78 	"stop=kill -STOP",
79 	"suspend=kill -STOP $$",
80 #endif
81 	"autoload=typeset -fu",
82 	"functions=typeset -f",
83 	"history=fc -l",
84 	"nameref=typeset -n",
85 	"nohup=nohup ",
86 	Tr_fc_e_dash,
87 	"source=PATH=$PATH:. command .",
88 	"login=exec login",
89 	NULL,
90 	 /* this is what AT&T ksh seems to track, with the addition of emacs */
91 	Talias, "-tU",
92 	"cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
93 	"make", "mv", "pr", "rm", "sed", "sh", "vi", "who", NULL,
94 	NULL
95 };
96 
97 static const char *restr_com[] = {
98 	Ttypeset, "-r", "PATH", "ENV", "SHELL", NULL
99 };
100 
101 static bool initio_done;
102 
103 /* top-level parsing and execution environment */
104 static struct env env;
105 struct env *e = &env;
106 
107 static mksh_uari_t
rndsetup(void)108 rndsetup(void)
109 {
110 	register uint32_t h;
111 	struct {
112 		ALLOC_ITEM alloc_INT;
113 		void *dataptr, *stkptr, *mallocptr;
114 #if defined(__GLIBC__) && (__GLIBC__ >= 2)
115 		sigjmp_buf jbuf;
116 #endif
117 		struct timeval tv;
118 	} *bufptr;
119 	char *cp;
120 
121 	cp = alloc(sizeof(*bufptr) - ALLOC_SIZE, APERM);
122 #ifdef DEBUG
123 	/* clear the allocated space, for valgrind */
124 	memset(cp, 0, sizeof(*bufptr) - ALLOC_SIZE);
125 #endif
126 	/* undo what alloc() did to the malloc result address */
127 	bufptr = (void *)(cp - ALLOC_SIZE);
128 	/* PIE or something similar provides us with deltas here */
129 	bufptr->dataptr = &rndsetupstate;
130 	/* ASLR in at least Windows, Linux, some BSDs */
131 	bufptr->stkptr = &bufptr;
132 	/* randomised malloc in BSD (and possibly others) */
133 	bufptr->mallocptr = bufptr;
134 #if defined(__GLIBC__) && (__GLIBC__ >= 2)
135 	/* glibc pointer guard */
136 	sigsetjmp(bufptr->jbuf, 1);
137 #endif
138 	/* introduce variation (and yes, second arg MBZ for portability) */
139 	mksh_TIME(bufptr->tv);
140 
141 	h = chvt_rndsetup(bufptr, sizeof(*bufptr));
142 
143 	afree(cp, APERM);
144 	return ((mksh_uari_t)h);
145 }
146 
147 uint32_t
chvt_rndsetup(const void * bp,size_t sz)148 chvt_rndsetup(const void *bp, size_t sz)
149 {
150 	register uint32_t h;
151 
152 	NZATInit(h);
153 	/* variation through pid, ppid, and the works */
154 	NZATUpdateMem(h, &rndsetupstate, sizeof(rndsetupstate));
155 	/* some variation, some possibly entropy, depending on OE */
156 	NZATUpdateMem(h, bp, sz);
157 	NZAATFinish(h);
158 
159 	return (h);
160 }
161 
162 void
chvt_reinit(void)163 chvt_reinit(void)
164 {
165 	kshpid = procpid = getpid();
166 	ksheuid = geteuid();
167 	kshpgrp = getpgrp();
168 	kshppid = getppid();
169 }
170 
171 static const char *empty_argv[] = {
172 	"mksh", NULL
173 };
174 
175 static uint8_t
isuc(const char * cx)176 isuc(const char *cx) {
177 	char *cp, *x;
178 	uint8_t rv = 0;
179 
180 	if (!cx || !*cx)
181 		return (0);
182 
183 	/* uppercase a string duplicate */
184 	strdupx(x, cx, ATEMP);
185 	cp = x;
186 	while ((*cp = ksh_toupper(*cp)))
187 		++cp;
188 
189 	/* check for UTF-8 */
190 	if (strstr(x, "UTF-8") || strstr(x, "UTF8"))
191 		rv = 1;
192 
193 	/* free copy and out */
194 	afree(x, ATEMP);
195 	return (rv);
196 }
197 
198 static int
main_init(int argc,const char * argv[],Source ** sp,struct block ** lp)199 main_init(int argc, const char *argv[], Source **sp, struct block **lp)
200 {
201 	int argi, i;
202 	Source *s = NULL;
203 	struct block *l;
204 	unsigned char restricted, errexit, utf_flag;
205 	char *cp;
206 	const char *ccp, **wp;
207 	struct tbl *vp;
208 	struct stat s_stdin;
209 #if !defined(_PATH_DEFPATH) && defined(_CS_PATH)
210 	ssize_t k;
211 #endif
212 
213 	/* do things like getpgrp() et al. */
214 	chvt_reinit();
215 
216 	/* make sure argv[] is sane */
217 	if (!*argv) {
218 		argv = empty_argv;
219 		argc = 1;
220 	}
221 	kshname = argv[0];
222 
223 	/* initialise permanent Area */
224 	ainit(&aperm);
225 
226 	/* set up base environment */
227 	env.type = E_NONE;
228 	ainit(&env.area);
229 	/* set up global l->vars and l->funs */
230 	newblock();
231 
232 	/* Do this first so output routines (eg, errorf, shellf) can work */
233 	initio();
234 
235 	/* determine the basename (without '-' or path) of the executable */
236 	ccp = kshname;
237 	goto begin_parse_kshname;
238 	while ((i = ccp[argi++])) {
239 		if (i == '/') {
240 			ccp += argi;
241  begin_parse_kshname:
242 			argi = 0;
243 			if (*ccp == '-')
244 				++ccp;
245 		}
246 	}
247 	if (!*ccp)
248 		ccp = empty_argv[0];
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 	/*
333 	 * Turn on nohup by default for now - will change to off
334 	 * by default once people are aware of its existence
335 	 * (AT&T ksh does not have a nohup option - it always sends
336 	 * the hup).
337 	 */
338 	Flag(FNOHUP) = 1;
339 
340 	/*
341 	 * Turn on brace expansion by default. AT&T kshs that have
342 	 * alternation always have it on.
343 	 */
344 	Flag(FBRACEEXPAND) = 1;
345 
346 	/*
347 	 * Turn on "set -x" inheritance by default.
348 	 */
349 	Flag(FXTRACEREC) = 1;
350 
351 #ifndef MKSH_NO_CMDLINE_EDITING
352 	/*
353 	 * Set edit mode to emacs by default, may be overridden
354 	 * by the environment or the user. Also, we want tab completion
355 	 * on in vi by default.
356 	 */
357 	change_flag(FEMACS, OF_SPECIAL, true);
358 #if !MKSH_S_NOVI
359 	Flag(FVITABCOMPLETE) = 1;
360 #endif
361 #endif
362 
363 	/* import environment */
364 	if (environ != NULL)
365 		for (wp = (const char **)environ; *wp != NULL; wp++)
366 			typeset(*wp, IMPORT | EXPORT, 0, 0, 0);
367 
368 	/* for security */
369 	typeset(initifs, 0, 0, 0, 0);
370 
371 	/* assign default shell variable values */
372 	substitute(initsubs, 0);
373 
374 	/* Figure out the current working directory and set $PWD */
375 	vp = global("PWD");
376 	cp = str_val(vp);
377 	/* Try to use existing $PWD if it is valid */
378 	set_current_wd((cp[0] == '/' && test_eval(NULL, TO_FILEQ, cp, ".",
379 	    true)) ? cp : NULL);
380 	if (current_wd[0])
381 		simplify_path(current_wd);
382 	/* Only set pwd if we know where we are or if it had a bogus value */
383 	if (current_wd[0] || *cp)
384 		/* setstr can't fail here */
385 		setstr(vp, current_wd, KSH_RETURN_ERROR);
386 
387 	for (wp = initcoms; *wp != NULL; wp++) {
388 		shcomexec(wp);
389 		while (*wp != NULL)
390 			wp++;
391 	}
392 	setint_n(global("OPTIND"), 1, 10);
393 
394 	kshuid = getuid();
395 	kshgid = getgid();
396 	kshegid = getegid();
397 
398 	safe_prompt = ksheuid ? "$ " : "# ";
399 	vp = global("PS1");
400 	/* Set PS1 if unset or we are root and prompt doesn't contain a # */
401 	if (!(vp->flag & ISSET) ||
402 	    (!ksheuid && !strchr(str_val(vp), '#')))
403 		/* setstr can't fail here */
404 		setstr(vp, safe_prompt, KSH_RETURN_ERROR);
405 	setint_n((vp = global("BASHPID")), 0, 10);
406 	vp->flag |= INT_U;
407 	setint_n((vp = global("PGRP")), (mksh_uari_t)kshpgrp, 10);
408 	vp->flag |= INT_U;
409 	setint_n((vp = global("PPID")), (mksh_uari_t)kshppid, 10);
410 	vp->flag |= INT_U;
411 	setint_n((vp = global("USER_ID")), (mksh_uari_t)ksheuid, 10);
412 	vp->flag |= INT_U;
413 	setint_n((vp = global("KSHUID")), (mksh_uari_t)kshuid, 10);
414 	vp->flag |= INT_U;
415 	setint_n((vp = global("KSHEGID")), (mksh_uari_t)kshegid, 10);
416 	vp->flag |= INT_U;
417 	setint_n((vp = global("KSHGID")), (mksh_uari_t)kshgid, 10);
418 	vp->flag |= INT_U;
419 	setint_n((vp = global("RANDOM")), rndsetup(), 10);
420 	vp->flag |= INT_U;
421 	setint_n((vp_pipest = global("PIPESTATUS")), 0, 10);
422 
423 	/* Set this before parsing arguments */
424 	Flag(FPRIVILEGED) = kshuid != ksheuid || kshgid != kshegid;
425 
426 	/* this to note if monitor is set on command line (see below) */
427 #ifndef MKSH_UNEMPLOYED
428 	Flag(FMONITOR) = 127;
429 #endif
430 	/* this to note if utf-8 mode is set on command line (see below) */
431 	UTFMODE = 2;
432 
433 	if (!Flag(FAS_BUILTIN)) {
434 		argi = parse_args(argv, OF_CMDLINE, NULL);
435 		if (argi < 0)
436 			return (1);
437 	}
438 
439 #if defined(DEBUG) && !defined(MKSH_LEGACY_MODE)
440 	/* test wraparound of arithmetic types */
441 	{
442 		volatile long xl;
443 		volatile unsigned long xul;
444 		volatile int xi;
445 		volatile unsigned int xui;
446 		volatile mksh_ari_t xa;
447 		volatile mksh_uari_t xua, xua2;
448 		volatile uint8_t xc;
449 
450 		xa = 2147483647;
451 		xua = 2147483647;
452 		++xa;
453 		++xua;
454 		xua2 = xa;
455 		xl = xa;
456 		xul = xua;
457 		xa = 0;
458 		xua = 0;
459 		--xa;
460 		--xua;
461 		xi = xa;
462 		xui = xua;
463 		xa = -1;
464 		xua = xa;
465 		++xa;
466 		++xua;
467 		xc = 0;
468 		--xc;
469 		if ((xua2 != 2147483648UL) ||
470 		    (xl != (-2147483647L-1)) || (xul != 2147483648UL) ||
471 		    (xi != -1) || (xui != 4294967295U) ||
472 		    (xa != 0) || (xua != 0) || (xc != 255))
473 			errorf("integer wraparound test failed");
474 	}
475 #endif
476 
477 	/* process this later only, default to off (hysterical raisins) */
478 	utf_flag = UTFMODE;
479 	UTFMODE = 0;
480 
481 	if (Flag(FAS_BUILTIN)) {
482 		/* auto-detect from environment variables, always */
483 		utf_flag = 3;
484 	} else if (Flag(FCOMMAND)) {
485 		s = pushs(SSTRINGCMDLINE, ATEMP);
486 		if (!(s->start = s->str = argv[argi++]))
487 			errorf("%s %s", "-c", "requires an argument");
488 #if !defined(MKSH_SMALL)
489 		while (*s->str) {
490 			if (*s->str != ' ' && ctype(*s->str, C_QUOTE))
491 				break;
492 			s->str++;
493 		}
494 		if (!*s->str)
495 			s->flags |= SF_MAYEXEC;
496 		s->str = s->start;
497 #endif
498 #ifdef MKSH_MIDNIGHTBSD01ASH_COMPAT
499 		/* compatibility to MidnightBSD 0.1 /bin/sh (kludge) */
500 		if (Flag(FSH) && argv[argi] && !strcmp(argv[argi], "--"))
501 			++argi;
502 #endif
503 		if (argv[argi])
504 			kshname = argv[argi++];
505 	} else if (argi < argc && !Flag(FSTDIN)) {
506 		s = pushs(SFILE, ATEMP);
507 		s->file = argv[argi++];
508 		s->u.shf = shf_open(s->file, O_RDONLY, 0,
509 		    SHF_MAPHI | SHF_CLEXEC);
510 		if (s->u.shf == NULL) {
511 			shl_stdout_ok = false;
512 			warningf(true, "%s: %s", s->file, cstrerror(errno));
513 			/* mandated by SUSv4 */
514 			exstat = 127;
515 			unwind(LERROR);
516 		}
517 		kshname = s->file;
518 	} else {
519 		Flag(FSTDIN) = 1;
520 		s = pushs(SSTDIN, ATEMP);
521 		s->file = "<stdin>";
522 		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
523 		    NULL);
524 		if (isatty(0) && isatty(2)) {
525 			Flag(FTALKING) = Flag(FTALKING_I) = 1;
526 			/* The following only if isatty(0) */
527 			s->flags |= SF_TTY;
528 			s->u.shf->flags |= SHF_INTERRUPT;
529 			s->file = NULL;
530 		}
531 	}
532 
533 	/* this bizarreness is mandated by POSIX */
534 	if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
535 	    Flag(FTALKING))
536 		reset_nonblock(0);
537 
538 	/* initialise job control */
539 	j_init();
540 	/* do this after j_init() which calls tty_init_state() */
541 	if (Flag(FTALKING)) {
542 		if (utf_flag == 2) {
543 #ifndef MKSH_ASSUME_UTF8
544 			/* auto-detect from locale or environment */
545 			utf_flag = 4;
546 #elif MKSH_ASSUME_UTF8
547 			utf_flag = 1;
548 #else
549 			/* always disable UTF-8 (for interactive) */
550 			utf_flag = 0;
551 #endif
552 		}
553 #ifndef MKSH_NO_CMDLINE_EDITING
554 		x_init();
555 #endif
556 	}
557 
558 #ifdef SIGWINCH
559 	sigtraps[SIGWINCH].flags |= TF_SHELL_USES;
560 	setsig(&sigtraps[SIGWINCH], x_sigwinch,
561 	    SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
562 #endif
563 
564 	l = e->loc;
565 	if (Flag(FAS_BUILTIN)) {
566 		l->argc = argc;
567 		l->argv = argv;
568 		l->argv[0] = ccp;
569 	} else {
570 		l->argc = argc - argi;
571 		/*
572 		 * allocate a new array because otherwise, when we modify
573 		 * it in-place, ps(1) output changes; the meaning of argc
574 		 * here is slightly different as it excludes kshname, and
575 		 * we add a trailing NULL sentinel as well
576 		 */
577 		l->argv = alloc2(l->argc + 2, sizeof(void *), APERM);
578 		l->argv[0] = kshname;
579 		memcpy(&l->argv[1], &argv[argi], l->argc * sizeof(void *));
580 		l->argv[l->argc + 1] = NULL;
581 		getopts_reset(1);
582 	}
583 
584 	/* divine the initial state of the utf8-mode Flag */
585 	ccp = null;
586 	switch (utf_flag) {
587 
588 	/* auto-detect from locale or environment */
589 	case 4:
590 #if HAVE_SETLOCALE_CTYPE
591 		ccp = setlocale(LC_CTYPE, "");
592 #if HAVE_LANGINFO_CODESET
593 		if (!isuc(ccp))
594 			ccp = nl_langinfo(CODESET);
595 #endif
596 		if (!isuc(ccp))
597 			ccp = null;
598 		/* FALLTHROUGH */
599 #endif
600 
601 	/* auto-detect from environment */
602 	case 3:
603 		/* these were imported from environ earlier */
604 		if (ccp == null)
605 			ccp = str_val(global("LC_ALL"));
606 		if (ccp == null)
607 			ccp = str_val(global("LC_CTYPE"));
608 		if (ccp == null)
609 			ccp = str_val(global("LANG"));
610 		UTFMODE = isuc(ccp);
611 		break;
612 
613 	/* not set on command line, not FTALKING */
614 	case 2:
615 	/* unknown values */
616 	default:
617 		utf_flag = 0;
618 		/* FALLTHROUGH */
619 
620 	/* known values */
621 	case 1:
622 	case 0:
623 		UTFMODE = utf_flag;
624 		break;
625 	}
626 
627 	/* Disable during .profile/ENV reading */
628 	restricted = Flag(FRESTRICTED);
629 	Flag(FRESTRICTED) = 0;
630 	errexit = Flag(FERREXIT);
631 	Flag(FERREXIT) = 0;
632 
633 	/*
634 	 * Do this before profile/$ENV so that if it causes problems in them,
635 	 * user will know why things broke.
636 	 */
637 	if (!current_wd[0] && Flag(FTALKING))
638 		warningf(false, "can't determine current directory");
639 
640 	if (Flag(FLOGIN)) {
641 		include(MKSH_SYSTEM_PROFILE, 0, NULL, true);
642 		if (!Flag(FPRIVILEGED))
643 			include(substitute("$HOME/.profile", 0), 0,
644 			    NULL, true);
645 	}
646 	if (Flag(FPRIVILEGED))
647 		include(MKSH_SUID_PROFILE, 0, NULL, true);
648 	else if (Flag(FTALKING)) {
649 		char *env_file;
650 
651 		/* include $ENV */
652 		env_file = substitute(substitute("${ENV:-" MKSHRC_PATH "}", 0),
653 		    DOTILDE);
654 		if (*env_file != '\0')
655 			include(env_file, 0, NULL, true);
656 	}
657 
658 	if (restricted) {
659 		shcomexec(restr_com);
660 		/* After typeset command... */
661 		Flag(FRESTRICTED) = 1;
662 	}
663 	Flag(FERREXIT) = errexit;
664 
665 	if (Flag(FTALKING) && s)
666 		hist_init(s);
667 	else
668 		/* set after ENV */
669 		Flag(FTRACKALL) = 1;
670 
671 	alarm_init();
672 
673 	*sp = s;
674 	*lp = l;
675 	return (0);
676 }
677 
678 /* this indirection barrier reduces stack usage during normal operation */
679 
680 int
main(int argc,const char * argv[])681 main(int argc, const char *argv[])
682 {
683 	int rv;
684 	Source *s;
685 	struct block *l;
686 
687 	if ((rv = main_init(argc, argv, &s, &l)) == 0) {
688 		if (Flag(FAS_BUILTIN)) {
689 			rv = shcomexec(l->argv);
690 		} else {
691 			shell(s, true);
692 			/* NOTREACHED */
693 		}
694 	}
695 	return (rv);
696 }
697 
698 int
include(const char * name,int argc,const char ** argv,bool intr_ok)699 include(const char *name, int argc, const char **argv, bool intr_ok)
700 {
701 	Source *volatile s = NULL;
702 	struct shf *shf;
703 	const char **volatile old_argv;
704 	volatile int old_argc;
705 	int i;
706 
707 	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI | SHF_CLEXEC);
708 	if (shf == NULL)
709 		return (-1);
710 
711 	if (argv) {
712 		old_argv = e->loc->argv;
713 		old_argc = e->loc->argc;
714 	} else {
715 		old_argv = NULL;
716 		old_argc = 0;
717 	}
718 	newenv(E_INCL);
719 	if ((i = kshsetjmp(e->jbuf))) {
720 		quitenv(s ? s->u.shf : NULL);
721 		if (old_argv) {
722 			e->loc->argv = old_argv;
723 			e->loc->argc = old_argc;
724 		}
725 		switch (i) {
726 		case LRETURN:
727 		case LERROR:
728 			/* see below */
729 			return (exstat & 0xFF);
730 		case LINTR:
731 			/*
732 			 * intr_ok is set if we are including .profile or $ENV.
733 			 * If user ^Cs out, we don't want to kill the shell...
734 			 */
735 			if (intr_ok && ((exstat & 0xFF) - 128) != SIGTERM)
736 				return (1);
737 			/* FALLTHROUGH */
738 		case LEXIT:
739 		case LLEAVE:
740 		case LSHELL:
741 			unwind(i);
742 			/* NOTREACHED */
743 		default:
744 			internal_errorf("%s %d", "include", i);
745 			/* NOTREACHED */
746 		}
747 	}
748 	if (argv) {
749 		e->loc->argv = argv;
750 		e->loc->argc = argc;
751 	}
752 	s = pushs(SFILE, ATEMP);
753 	s->u.shf = shf;
754 	strdupx(s->file, name, ATEMP);
755 	i = shell(s, false);
756 	quitenv(s->u.shf);
757 	if (old_argv) {
758 		e->loc->argv = old_argv;
759 		e->loc->argc = old_argc;
760 	}
761 	/* & 0xff to ensure value not -1 */
762 	return (i & 0xFF);
763 }
764 
765 /* spawn a command into a shell optionally keeping track of the line number */
766 int
command(const char * comm,int line)767 command(const char *comm, int line)
768 {
769 	Source *s;
770 
771 	s = pushs(SSTRING, ATEMP);
772 	s->start = s->str = comm;
773 	s->line = line;
774 	return (shell(s, false));
775 }
776 
777 /*
778  * run the commands from the input source, returning status.
779  */
780 int
shell(Source * volatile s,volatile bool toplevel)781 shell(Source * volatile s, volatile bool toplevel)
782 {
783 	struct op *t;
784 	volatile bool wastty = tobool(s->flags & SF_TTY);
785 	volatile uint8_t attempts = 13;
786 	volatile bool interactive = Flag(FTALKING) && toplevel;
787 	volatile bool sfirst = true;
788 	Source *volatile old_source = source;
789 	int i;
790 
791 	newenv(E_PARSE);
792 	if (interactive)
793 		really_exit = false;
794 	switch ((i = kshsetjmp(e->jbuf))) {
795 	case 0:
796 		break;
797 	case LINTR:
798 		/* we get here if SIGINT not caught or ignored */
799 	case LERROR:
800 	case LSHELL:
801 		if (interactive) {
802 			if (i == LINTR)
803 				shellf("\n");
804 			/*
805 			 * Reset any eof that was read as part of a
806 			 * multiline command.
807 			 */
808 			if (Flag(FIGNOREEOF) && s->type == SEOF && wastty)
809 				s->type = SSTDIN;
810 			/*
811 			 * Used by exit command to get back to
812 			 * top level shell. Kind of strange since
813 			 * interactive is set if we are reading from
814 			 * a tty, but to have stopped jobs, one only
815 			 * needs FMONITOR set (not FTALKING/SF_TTY)...
816 			 */
817 			/* toss any input we have so far */
818 			yyrecursive_pop(true);
819 			s->start = s->str = null;
820 			retrace_info = NULL;
821 			herep = heres;
822 			break;
823 		}
824 		/* FALLTHROUGH */
825 	case LEXIT:
826 	case LLEAVE:
827 	case LRETURN:
828 		source = old_source;
829 		quitenv(NULL);
830 		/* keep on going */
831 		unwind(i);
832 		/* NOTREACHED */
833 	default:
834 		source = old_source;
835 		quitenv(NULL);
836 		internal_errorf("%s %d", "shell", i);
837 		/* NOTREACHED */
838 	}
839 	while (/* CONSTCOND */ 1) {
840 		if (trap)
841 			runtraps(0);
842 
843 		if (s->next == NULL) {
844 			if (Flag(FVERBOSE))
845 				s->flags |= SF_ECHO;
846 			else
847 				s->flags &= ~SF_ECHO;
848 		}
849 		if (interactive) {
850 			j_notify();
851 			set_prompt(PS1, s);
852 		}
853 		t = compile(s, sfirst);
854 		sfirst = false;
855 		if (!t)
856 			goto source_no_tree;
857 		if (t->type == TEOF) {
858 			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
859 				shellf("Use 'exit' to leave mksh\n");
860 				s->type = SSTDIN;
861 			} else if (wastty && !really_exit &&
862 			    j_stopped_running()) {
863 				really_exit = true;
864 				s->type = SSTDIN;
865 			} else {
866 				/*
867 				 * this for POSIX which says EXIT traps
868 				 * shall be taken in the environment
869 				 * immediately after the last command
870 				 * executed.
871 				 */
872 				if (toplevel)
873 					unwind(LEXIT);
874 				break;
875 			}
876 		}
877 #if !defined(MKSH_SMALL)
878 		  else if ((s->flags & SF_MAYEXEC) && t->type == TCOM)
879 			t->u.evalflags |= DOTCOMEXEC;
880 #endif
881 		if (!Flag(FNOEXEC) || (s->flags & SF_TTY))
882 			exstat = execute(t, 0, NULL) & 0xFF;
883 
884 		if (t->type != TEOF && interactive && really_exit)
885 			really_exit = false;
886 
887  source_no_tree:
888 		reclaim();
889 	}
890 	quitenv(NULL);
891 	source = old_source;
892 	return (exstat & 0xFF);
893 }
894 
895 /* return to closest error handler or shell(), exit if none found */
896 /* note: i MUST NOT be 0 */
897 void
unwind(int i)898 unwind(int i)
899 {
900 	/*
901 	 * This is a kludge. We need to restore everything that was
902 	 * changed in the new environment, see cid 1005090337C7A669439
903 	 * and 10050903386452ACBF1, but fail to even save things most of
904 	 * the time. funcs.c:c_eval() changes FERREXIT temporarily to 0,
905 	 * which needs to be restored thus (related to Debian #696823).
906 	 * We did not save the shell flags, so we use a special or'd
907 	 * value here... this is mostly to clean up behind *other*
908 	 * callers of unwind(LERROR) here; exec.c has the regular case.
909 	 */
910 	if (Flag(FERREXIT) & 0x80) {
911 		/* GNU bash does not run this trapsig */
912 		trapsig(ksh_SIGERR);
913 		Flag(FERREXIT) &= ~0x80;
914 	}
915 
916 	/* ordering for EXIT vs ERR is a bit odd (this is what AT&T ksh does) */
917 	if (i == LEXIT || ((i == LERROR || i == LINTR) &&
918 	    sigtraps[ksh_SIGEXIT].trap &&
919 	    (!Flag(FTALKING) || Flag(FERREXIT)))) {
920 		++trap_nested;
921 		runtrap(&sigtraps[ksh_SIGEXIT], trap_nested == 1);
922 		--trap_nested;
923 		i = LLEAVE;
924 	} else if (Flag(FERREXIT) == 1 && (i == LERROR || i == LINTR)) {
925 		++trap_nested;
926 		runtrap(&sigtraps[ksh_SIGERR], trap_nested == 1);
927 		--trap_nested;
928 		i = LLEAVE;
929 	}
930 
931 	while (/* CONSTCOND */ 1) {
932 		switch (e->type) {
933 		case E_PARSE:
934 		case E_FUNC:
935 		case E_INCL:
936 		case E_LOOP:
937 		case E_ERRH:
938 			kshlongjmp(e->jbuf, i);
939 			/* NOTREACHED */
940 		case E_NONE:
941 			if (i == LINTR)
942 				e->flags |= EF_FAKE_SIGDIE;
943 			/* FALLTHROUGH */
944 		default:
945 			quitenv(NULL);
946 		}
947 	}
948 }
949 
950 void
newenv(int type)951 newenv(int type)
952 {
953 	struct env *ep;
954 	char *cp;
955 
956 	/*
957 	 * struct env includes ALLOC_ITEM for alignment constraints
958 	 * so first get the actually used memory, then assign it
959 	 */
960 	cp = alloc(sizeof(struct env) - ALLOC_SIZE, ATEMP);
961 	/* undo what alloc() did to the malloc result address */
962 	ep = (void *)(cp - ALLOC_SIZE);
963 	/* initialise public members of struct env (not the ALLOC_ITEM) */
964 	ainit(&ep->area);
965 	ep->oenv = e;
966 	ep->loc = e->loc;
967 	ep->savefd = NULL;
968 	ep->temps = NULL;
969 	ep->yyrecursive_statep = NULL;
970 	ep->type = type;
971 	ep->flags = 0;
972 	/* jump buffer is invalid because flags == 0 */
973 	e = ep;
974 }
975 
976 void
quitenv(struct shf * shf)977 quitenv(struct shf *shf)
978 {
979 	struct env *ep = e;
980 	char *cp;
981 	int fd;
982 
983 	yyrecursive_pop(true);
984 	while (ep->oenv && ep->oenv->loc != ep->loc)
985 		popblock();
986 	if (ep->savefd != NULL) {
987 		for (fd = 0; fd < NUFILE; fd++)
988 			/* if ep->savefd[fd] < 0, means fd was closed */
989 			if (ep->savefd[fd])
990 				restfd(fd, ep->savefd[fd]);
991 		if (ep->savefd[2])
992 			/* Clear any write errors */
993 			shf_reopen(2, SHF_WR, shl_out);
994 	}
995 	/*
996 	 * Bottom of the stack.
997 	 * Either main shell is exiting or cleanup_parents_env() was called.
998 	 */
999 	if (ep->oenv == NULL) {
1000 #ifdef DEBUG_LEAKS
1001 		int i;
1002 #endif
1003 
1004 		if (ep->type == E_NONE) {
1005 			/* Main shell exiting? */
1006 #if HAVE_PERSISTENT_HISTORY
1007 			if (Flag(FTALKING))
1008 				hist_finish();
1009 #endif
1010 			j_exit();
1011 			if (ep->flags & EF_FAKE_SIGDIE) {
1012 				int sig = (exstat & 0xFF) - 128;
1013 
1014 				/*
1015 				 * ham up our death a bit (AT&T ksh
1016 				 * only seems to do this for SIGTERM)
1017 				 * Don't do it for SIGQUIT, since we'd
1018 				 * dump a core..
1019 				 */
1020 				if ((sig == SIGINT || sig == SIGTERM) &&
1021 				    (kshpgrp == kshpid)) {
1022 					setsig(&sigtraps[sig], SIG_DFL,
1023 					    SS_RESTORE_CURR | SS_FORCE);
1024 					kill(0, sig);
1025 				}
1026 			}
1027 		}
1028 		if (shf)
1029 			shf_close(shf);
1030 		reclaim();
1031 #ifdef DEBUG_LEAKS
1032 #ifndef MKSH_NO_CMDLINE_EDITING
1033 		x_done();
1034 #endif
1035 #ifndef MKSH_NOPROSPECTOFWORK
1036 		/* block at least SIGCHLD during/after afreeall */
1037 		sigprocmask(SIG_BLOCK, &sm_sigchld, NULL);
1038 #endif
1039 		afreeall(APERM);
1040 		for (fd = 3; fd < NUFILE; fd++)
1041 			if ((i = fcntl(fd, F_GETFD, 0)) != -1 &&
1042 			    (i & FD_CLOEXEC))
1043 				close(fd);
1044 		close(2);
1045 		close(1);
1046 		close(0);
1047 #endif
1048 		exit(exstat & 0xFF);
1049 	}
1050 	if (shf)
1051 		shf_close(shf);
1052 	reclaim();
1053 
1054 	e = e->oenv;
1055 
1056 	/* free the struct env - tricky due to the ALLOC_ITEM inside */
1057 	cp = (void *)ep;
1058 	afree(cp + ALLOC_SIZE, ATEMP);
1059 }
1060 
1061 /* Called after a fork to cleanup stuff left over from parents environment */
1062 void
cleanup_parents_env(void)1063 cleanup_parents_env(void)
1064 {
1065 	struct env *ep;
1066 	int fd;
1067 
1068 	mkssert(e != NULL);
1069 
1070 	/*
1071 	 * Don't clean up temporary files - parent will probably need them.
1072 	 * Also, can't easily reclaim memory since variables, etc. could be
1073 	 * anywhere.
1074 	 */
1075 
1076 	/* close all file descriptors hiding in savefd */
1077 	for (ep = e; ep; ep = ep->oenv) {
1078 		if (ep->savefd) {
1079 			for (fd = 0; fd < NUFILE; fd++)
1080 				if (ep->savefd[fd] > 0)
1081 					close(ep->savefd[fd]);
1082 			afree(ep->savefd, &ep->area);
1083 			ep->savefd = NULL;
1084 		}
1085 #ifdef DEBUG_LEAKS
1086 		if (ep->type != E_NONE)
1087 			ep->type = E_GONE;
1088 #endif
1089 	}
1090 #ifndef DEBUG_LEAKS
1091 	e->oenv = NULL;
1092 #endif
1093 }
1094 
1095 /* Called just before an execve cleanup stuff temporary files */
1096 void
cleanup_proc_env(void)1097 cleanup_proc_env(void)
1098 {
1099 	struct env *ep;
1100 
1101 	for (ep = e; ep; ep = ep->oenv)
1102 		remove_temps(ep->temps);
1103 }
1104 
1105 /* remove temp files and free ATEMP Area */
1106 static void
reclaim(void)1107 reclaim(void)
1108 {
1109 	struct block *l;
1110 
1111 	while ((l = e->loc) && (!e->oenv || e->oenv->loc != l)) {
1112 		e->loc = l->next;
1113 		afreeall(&l->area);
1114 	}
1115 
1116 	remove_temps(e->temps);
1117 	e->temps = NULL;
1118 	afreeall(&e->area);
1119 }
1120 
1121 static void
remove_temps(struct temp * tp)1122 remove_temps(struct temp *tp)
1123 {
1124 	for (; tp != NULL; tp = tp->next)
1125 		if (tp->pid == procpid)
1126 			unlink(tp->tffn);
1127 }
1128 
1129 /*
1130  * Initialise tty_fd. Used for tracking the size of the terminal,
1131  * saving/resetting tty modes upon forground job completion, and
1132  * for setting up the tty process group. Return values:
1133  *	0 = got controlling tty
1134  *	1 = got terminal but no controlling tty
1135  *	2 = cannot find a terminal
1136  *	3 = cannot dup fd
1137  *	4 = cannot make fd close-on-exec
1138  * An existing tty_fd is cached if no "better" one could be found,
1139  * i.e. if tty_devtty was already set or the new would not set it.
1140  */
1141 int
tty_init_fd(void)1142 tty_init_fd(void)
1143 {
1144 	int fd, rv, eno = 0;
1145 	bool do_close = false, is_devtty = true;
1146 
1147 	if (tty_devtty) {
1148 		/* already got a tty which is /dev/tty */
1149 		return (0);
1150 	}
1151 
1152 #ifdef _UWIN
1153 	/*XXX imake style */
1154 	if (isatty(3)) {
1155 		/* fd 3 on UWIN _is_ /dev/tty (or our controlling tty) */
1156 		fd = 3;
1157 		goto got_fd;
1158 	}
1159 #endif
1160 	if ((fd = open("/dev/tty", O_RDWR, 0)) >= 0) {
1161 		do_close = true;
1162 		goto got_fd;
1163 	}
1164 	eno = errno;
1165 
1166 	if (tty_fd >= 0) {
1167 		/* already got a non-devtty one */
1168 		rv = 1;
1169 		goto out;
1170 	}
1171 	is_devtty = false;
1172 
1173 	if (isatty((fd = 0)) || isatty((fd = 2)))
1174 		goto got_fd;
1175 	/* cannot find one */
1176 	rv = 2;
1177 	/* assert: do_close == false */
1178 	goto out;
1179 
1180  got_fd:
1181 	if ((rv = fcntl(fd, F_DUPFD, FDBASE)) < 0) {
1182 		eno = errno;
1183 		rv = 3;
1184 		goto out;
1185 	}
1186 	if (fcntl(rv, F_SETFD, FD_CLOEXEC) < 0) {
1187 		eno = errno;
1188 		close(rv);
1189 		rv = 4;
1190 		goto out;
1191 	}
1192 	tty_fd = rv;
1193 	tty_devtty = is_devtty;
1194 	rv = eno = 0;
1195  out:
1196 	if (do_close)
1197 		close(fd);
1198 	errno = eno;
1199 	return (rv);
1200 }
1201 
1202 /* A shell error occurred (eg, syntax error, etc.) */
1203 
1204 #define VWARNINGF_ERRORPREFIX	1
1205 #define VWARNINGF_FILELINE	2
1206 #define VWARNINGF_BUILTIN	4
1207 #define VWARNINGF_INTERNAL	8
1208 
1209 static void vwarningf(unsigned int, const char *, va_list)
1210     MKSH_A_FORMAT(__printf__, 2, 0);
1211 
1212 static void
vwarningf(unsigned int flags,const char * fmt,va_list ap)1213 vwarningf(unsigned int flags, const char *fmt, va_list ap)
1214 {
1215 	if (fmt) {
1216 		if (flags & VWARNINGF_INTERNAL)
1217 			shf_fprintf(shl_out, "internal error: ");
1218 		if (flags & VWARNINGF_ERRORPREFIX)
1219 			error_prefix(tobool(flags & VWARNINGF_FILELINE));
1220 		if ((flags & VWARNINGF_BUILTIN) &&
1221 		    /* not set when main() calls parse_args() */
1222 		    builtin_argv0 && builtin_argv0 != kshname)
1223 			shf_fprintf(shl_out, "%s: ", builtin_argv0);
1224 		shf_vfprintf(shl_out, fmt, ap);
1225 		shf_putchar('\n', shl_out);
1226 	}
1227 	shf_flush(shl_out);
1228 }
1229 
1230 void
errorfx(int rc,const char * fmt,...)1231 errorfx(int rc, const char *fmt, ...)
1232 {
1233 	va_list va;
1234 
1235 	exstat = rc;
1236 
1237 	/* debugging: note that stdout not valid */
1238 	shl_stdout_ok = false;
1239 
1240 	va_start(va, fmt);
1241 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1242 	va_end(va);
1243 	unwind(LERROR);
1244 }
1245 
1246 void
errorf(const char * fmt,...)1247 errorf(const char *fmt, ...)
1248 {
1249 	va_list va;
1250 
1251 	exstat = 1;
1252 
1253 	/* debugging: note that stdout not valid */
1254 	shl_stdout_ok = false;
1255 
1256 	va_start(va, fmt);
1257 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1258 	va_end(va);
1259 	unwind(LERROR);
1260 }
1261 
1262 /* like errorf(), but no unwind is done */
1263 void
warningf(bool fileline,const char * fmt,...)1264 warningf(bool fileline, const char *fmt, ...)
1265 {
1266 	va_list va;
1267 
1268 	va_start(va, fmt);
1269 	vwarningf(VWARNINGF_ERRORPREFIX | (fileline ? VWARNINGF_FILELINE : 0),
1270 	    fmt, va);
1271 	va_end(va);
1272 }
1273 
1274 /*
1275  * Used by built-in utilities to prefix shell and utility name to message
1276  * (also unwinds environments for special builtins).
1277  */
1278 void
bi_errorf(const char * fmt,...)1279 bi_errorf(const char *fmt, ...)
1280 {
1281 	va_list va;
1282 
1283 	/* debugging: note that stdout not valid */
1284 	shl_stdout_ok = false;
1285 
1286 	exstat = 1;
1287 
1288 	va_start(va, fmt);
1289 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE |
1290 	    VWARNINGF_BUILTIN, fmt, va);
1291 	va_end(va);
1292 
1293 	/*
1294 	 * POSIX special builtins and ksh special builtins cause
1295 	 * non-interactive shells to exit.
1296 	 * XXX odd use of KEEPASN; also may not want LERROR here
1297 	 */
1298 	if (builtin_flag & SPEC_BI) {
1299 		builtin_argv0 = NULL;
1300 		unwind(LERROR);
1301 	}
1302 }
1303 
1304 /* Called when something that shouldn't happen does */
1305 void
internal_errorf(const char * fmt,...)1306 internal_errorf(const char *fmt, ...)
1307 {
1308 	va_list va;
1309 
1310 	va_start(va, fmt);
1311 	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1312 	va_end(va);
1313 	unwind(LERROR);
1314 }
1315 
1316 void
internal_warningf(const char * fmt,...)1317 internal_warningf(const char *fmt, ...)
1318 {
1319 	va_list va;
1320 
1321 	va_start(va, fmt);
1322 	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1323 	va_end(va);
1324 }
1325 
1326 /* used by error reporting functions to print "ksh: .kshrc[25]: " */
1327 void
error_prefix(bool fileline)1328 error_prefix(bool fileline)
1329 {
1330 	/* Avoid foo: foo[2]: ... */
1331 	if (!fileline || !source || !source->file ||
1332 	    strcmp(source->file, kshname) != 0)
1333 		shf_fprintf(shl_out, "%s: ", kshname + (*kshname == '-'));
1334 	if (fileline && source && source->file != NULL) {
1335 		shf_fprintf(shl_out, "%s[%d]: ", source->file,
1336 		    source->errline > 0 ? source->errline : source->line);
1337 		source->errline = 0;
1338 	}
1339 }
1340 
1341 /* printf to shl_out (stderr) with flush */
1342 void
shellf(const char * fmt,...)1343 shellf(const char *fmt, ...)
1344 {
1345 	va_list va;
1346 
1347 	if (!initio_done)
1348 		/* shl_out may not be set up yet... */
1349 		return;
1350 	va_start(va, fmt);
1351 	shf_vfprintf(shl_out, fmt, va);
1352 	va_end(va);
1353 	shf_flush(shl_out);
1354 }
1355 
1356 /* printf to shl_stdout (stdout) */
1357 void
shprintf(const char * fmt,...)1358 shprintf(const char *fmt, ...)
1359 {
1360 	va_list va;
1361 
1362 	if (!shl_stdout_ok)
1363 		internal_errorf("shl_stdout not valid");
1364 	va_start(va, fmt);
1365 	shf_vfprintf(shl_stdout, fmt, va);
1366 	va_end(va);
1367 }
1368 
1369 /* test if we can seek backwards fd (returns 0 or SHF_UNBUF) */
1370 int
can_seek(int fd)1371 can_seek(int fd)
1372 {
1373 	struct stat statb;
1374 
1375 	return (fstat(fd, &statb) == 0 && !S_ISREG(statb.st_mode) ?
1376 	    SHF_UNBUF : 0);
1377 }
1378 
1379 #ifdef DF
1380 int shl_dbg_fd;
1381 #define NSHF_IOB 4
1382 #else
1383 #define NSHF_IOB 3
1384 #endif
1385 struct shf shf_iob[NSHF_IOB];
1386 
1387 void
initio(void)1388 initio(void)
1389 {
1390 #ifdef DF
1391 	const char *lfp;
1392 #endif
1393 
1394 	/* force buffer allocation */
1395 	shf_fdopen(1, SHF_WR, shl_stdout);
1396 	shf_fdopen(2, SHF_WR, shl_out);
1397 	shf_fdopen(2, SHF_WR, shl_xtrace);
1398 #ifdef DF
1399 	if ((lfp = getenv("SDMKSH_PATH")) == NULL) {
1400 		if ((lfp = getenv("HOME")) == NULL || *lfp != '/')
1401 			errorf("cannot get home directory");
1402 		lfp = shf_smprintf("%s/mksh-dbg.txt", lfp);
1403 	}
1404 
1405 	if ((shl_dbg_fd = open(lfp, O_WRONLY | O_APPEND | O_CREAT, 0600)) < 0)
1406 		errorf("cannot open debug output file %s", lfp);
1407 	if (shl_dbg_fd < FDBASE) {
1408 		int nfd;
1409 
1410 		nfd = fcntl(shl_dbg_fd, F_DUPFD, FDBASE);
1411 		close(shl_dbg_fd);
1412 		if ((shl_dbg_fd = nfd) == -1)
1413 			errorf("cannot dup debug output file");
1414 	}
1415 	fcntl(shl_dbg_fd, F_SETFD, FD_CLOEXEC);
1416 	shf_fdopen(shl_dbg_fd, SHF_WR, shl_dbg);
1417 	DF("=== open ===");
1418 #endif
1419 	initio_done = true;
1420 }
1421 
1422 /* A dup2() with error checking */
1423 int
ksh_dup2(int ofd,int nfd,bool errok)1424 ksh_dup2(int ofd, int nfd, bool errok)
1425 {
1426 	int rv;
1427 
1428 	if (((rv = dup2(ofd, nfd)) < 0) && !errok && (errno != EBADF))
1429 		errorf("too many files open in shell");
1430 
1431 #ifdef __ultrix
1432 	/*XXX imake style */
1433 	if (rv >= 0)
1434 		fcntl(nfd, F_SETFD, 0);
1435 #endif
1436 
1437 	return (rv);
1438 }
1439 
1440 /*
1441  * Move fd from user space (0 <= fd < 10) to shell space (fd >= 10),
1442  * set close-on-exec flag. See FDBASE in sh.h, maybe 24 not 10 here.
1443  */
1444 short
savefd(int fd)1445 savefd(int fd)
1446 {
1447 	int nfd = fd;
1448 
1449 	if (fd < FDBASE && (nfd = fcntl(fd, F_DUPFD, FDBASE)) < 0 &&
1450 	    errno == EBADF)
1451 		return (-1);
1452 	if (nfd < 0 || nfd > SHRT_MAX)
1453 		errorf("too many files open in shell");
1454 	fcntl(nfd, F_SETFD, FD_CLOEXEC);
1455 	return ((short)nfd);
1456 }
1457 
1458 void
restfd(int fd,int ofd)1459 restfd(int fd, int ofd)
1460 {
1461 	if (fd == 2)
1462 		shf_flush(&shf_iob[/* fd */ 2]);
1463 	if (ofd < 0)
1464 		/* original fd closed */
1465 		close(fd);
1466 	else if (fd != ofd) {
1467 		/*XXX: what to do if this dup fails? */
1468 		ksh_dup2(ofd, fd, true);
1469 		close(ofd);
1470 	}
1471 }
1472 
1473 void
openpipe(int * pv)1474 openpipe(int *pv)
1475 {
1476 	int lpv[2];
1477 
1478 	if (pipe(lpv) < 0)
1479 		errorf("can't create pipe - try again");
1480 	pv[0] = savefd(lpv[0]);
1481 	if (pv[0] != lpv[0])
1482 		close(lpv[0]);
1483 	pv[1] = savefd(lpv[1]);
1484 	if (pv[1] != lpv[1])
1485 		close(lpv[1]);
1486 }
1487 
1488 void
closepipe(int * pv)1489 closepipe(int *pv)
1490 {
1491 	close(pv[0]);
1492 	close(pv[1]);
1493 }
1494 
1495 /*
1496  * Called by iosetup() (deals with 2>&4, etc.), c_read, c_print to turn
1497  * a string (the X in 2>&X, read -uX, print -uX) into a file descriptor.
1498  */
1499 int
check_fd(const char * name,int mode,const char ** emsgp)1500 check_fd(const char *name, int mode, const char **emsgp)
1501 {
1502 	int fd, fl;
1503 
1504 	if (name[0] == 'p' && !name[1])
1505 		return (coproc_getfd(mode, emsgp));
1506 	for (fd = 0; ksh_isdigit(*name); ++name)
1507 		fd = (fd * 10) + *name - '0';
1508 	if (*name || fd >= FDBASE) {
1509 		if (emsgp)
1510 			*emsgp = "illegal file descriptor name";
1511 		return (-1);
1512 	}
1513 	if ((fl = fcntl(fd, F_GETFL, 0)) < 0) {
1514 		if (emsgp)
1515 			*emsgp = "bad file descriptor";
1516 		return (-1);
1517 	}
1518 	fl &= O_ACCMODE;
1519 	/*
1520 	 * X_OK is a kludge to disable this check for dups (x<&1):
1521 	 * historical shells never did this check (XXX don't know what
1522 	 * POSIX has to say).
1523 	 */
1524 	if (!(mode & X_OK) && fl != O_RDWR && (
1525 	    ((mode & R_OK) && fl != O_RDONLY) ||
1526 	    ((mode & W_OK) && fl != O_WRONLY))) {
1527 		if (emsgp)
1528 			*emsgp = (fl == O_WRONLY) ?
1529 			    "fd not open for reading" :
1530 			    "fd not open for writing";
1531 		return (-1);
1532 	}
1533 	return (fd);
1534 }
1535 
1536 /* Called once from main */
1537 void
coproc_init(void)1538 coproc_init(void)
1539 {
1540 	coproc.read = coproc.readw = coproc.write = -1;
1541 	coproc.njobs = 0;
1542 	coproc.id = 0;
1543 }
1544 
1545 /* Called by c_read() when eof is read - close fd if it is the co-process fd */
1546 void
coproc_read_close(int fd)1547 coproc_read_close(int fd)
1548 {
1549 	if (coproc.read >= 0 && fd == coproc.read) {
1550 		coproc_readw_close(fd);
1551 		close(coproc.read);
1552 		coproc.read = -1;
1553 	}
1554 }
1555 
1556 /*
1557  * Called by c_read() and by iosetup() to close the other side of the
1558  * read pipe, so reads will actually terminate.
1559  */
1560 void
coproc_readw_close(int fd)1561 coproc_readw_close(int fd)
1562 {
1563 	if (coproc.readw >= 0 && coproc.read >= 0 && fd == coproc.read) {
1564 		close(coproc.readw);
1565 		coproc.readw = -1;
1566 	}
1567 }
1568 
1569 /*
1570  * Called by c_print when a write to a fd fails with EPIPE and by iosetup
1571  * when co-process input is dup'd
1572  */
1573 void
coproc_write_close(int fd)1574 coproc_write_close(int fd)
1575 {
1576 	if (coproc.write >= 0 && fd == coproc.write) {
1577 		close(coproc.write);
1578 		coproc.write = -1;
1579 	}
1580 }
1581 
1582 /*
1583  * Called to check for existence of/value of the co-process file descriptor.
1584  * (Used by check_fd() and by c_read/c_print to deal with -p option).
1585  */
1586 int
coproc_getfd(int mode,const char ** emsgp)1587 coproc_getfd(int mode, const char **emsgp)
1588 {
1589 	int fd = (mode & R_OK) ? coproc.read : coproc.write;
1590 
1591 	if (fd >= 0)
1592 		return (fd);
1593 	if (emsgp)
1594 		*emsgp = "no coprocess";
1595 	return (-1);
1596 }
1597 
1598 /*
1599  * called to close file descriptors related to the coprocess (if any)
1600  * Should be called with SIGCHLD blocked.
1601  */
1602 void
coproc_cleanup(int reuse)1603 coproc_cleanup(int reuse)
1604 {
1605 	/* This to allow co-processes to share output pipe */
1606 	if (!reuse || coproc.readw < 0 || coproc.read < 0) {
1607 		if (coproc.read >= 0) {
1608 			close(coproc.read);
1609 			coproc.read = -1;
1610 		}
1611 		if (coproc.readw >= 0) {
1612 			close(coproc.readw);
1613 			coproc.readw = -1;
1614 		}
1615 	}
1616 	if (coproc.write >= 0) {
1617 		close(coproc.write);
1618 		coproc.write = -1;
1619 	}
1620 }
1621 
1622 struct temp *
maketemp(Area * ap,Temp_type type,struct temp ** tlist)1623 maketemp(Area *ap, Temp_type type, struct temp **tlist)
1624 {
1625 	char *cp;
1626 	size_t len;
1627 	int i, j;
1628 	struct temp *tp;
1629 	const char *dir;
1630 	struct stat sb;
1631 
1632 	dir = tmpdir ? tmpdir : MKSH_DEFAULT_TMPDIR;
1633 	/* add "/shXXXXXX.tmp" plus NUL */
1634 	len = strlen(dir);
1635 	checkoktoadd(len, offsetof(struct temp, tffn[0]) + 14);
1636 	tp = alloc(offsetof(struct temp, tffn[0]) + 14 + len, ap);
1637 
1638 	tp->shf = NULL;
1639 	tp->pid = procpid;
1640 	tp->type = type;
1641 
1642 	if (stat(dir, &sb) || !S_ISDIR(sb.st_mode)) {
1643 		tp->tffn[0] = '\0';
1644 		goto maketemp_out;
1645 	}
1646 
1647 	cp = (void *)tp;
1648 	cp += offsetof(struct temp, tffn[0]);
1649 	memcpy(cp, dir, len);
1650 	cp += len;
1651 	memcpy(cp, "/shXXXXXX.tmp", 14);
1652 	/* point to the first of six Xes */
1653 	cp += 3;
1654 	/* generate random part of filename */
1655 	len = -1;
1656 	do {
1657 		i = rndget() % 36;
1658 		cp[++len] = i < 26 ? 'a' + i : '0' + i - 26;
1659 	} while (len < 5);
1660 
1661 	/* cyclically attempt to open a temporary file */
1662 	while ((i = open(tp->tffn, O_CREAT | O_EXCL | O_RDWR, 0600)) < 0) {
1663 		if (errno != EEXIST)
1664 			goto maketemp_out;
1665 		/* count down from z to a then from 9 to 0 */
1666 		while (cp[len] == '0')
1667 			if (!len--)
1668 				goto maketemp_out;
1669 		if (cp[len] == 'a')
1670 			cp[len] = '9';
1671 		else
1672 			--cp[len];
1673 		/* do another cycle */
1674 	}
1675 
1676 	if (type == TT_FUNSUB) {
1677 		/* map us high and mark as close-on-exec */
1678 		if ((j = savefd(i)) != i) {
1679 			close(i);
1680 			i = j;
1681 		}
1682 
1683 		/* operation mode for the shf */
1684 		j = SHF_RD;
1685 	} else
1686 		j = SHF_WR;
1687 
1688 	/* shf_fdopen cannot fail, so no fd leak */
1689 	tp->shf = shf_fdopen(i, j, NULL);
1690 
1691  maketemp_out:
1692 	tp->next = *tlist;
1693 	*tlist = tp;
1694 	return (tp);
1695 }
1696 
1697 /*
1698  * We use a similar collision resolution algorithm as Python 2.5.4
1699  * but with a slightly tweaked implementation written from scratch.
1700  */
1701 
1702 #define	INIT_TBLSHIFT	3	/* initial table shift (2^3 = 8) */
1703 #define PERTURB_SHIFT	5	/* see Python 2.5.4 Objects/dictobject.c */
1704 
1705 static void tgrow(struct table *);
1706 static int tnamecmp(const void *, const void *);
1707 
1708 static void
tgrow(struct table * tp)1709 tgrow(struct table *tp)
1710 {
1711 	size_t i, j, osize, mask, perturb;
1712 	struct tbl *tblp, **pp;
1713 	struct tbl **ntblp, **otblp = tp->tbls;
1714 
1715 	if (tp->tshift > 29)
1716 		internal_errorf("hash table size limit reached");
1717 
1718 	/* calculate old size, new shift and new size */
1719 	osize = (size_t)1 << (tp->tshift++);
1720 	i = osize << 1;
1721 
1722 	ntblp = alloc2(i, sizeof(struct tbl *), tp->areap);
1723 	/* multiplication cannot overflow: alloc2 checked that */
1724 	memset(ntblp, 0, i * sizeof(struct tbl *));
1725 
1726 	/* table can get very full when reaching its size limit */
1727 	tp->nfree = (tp->tshift == 30) ? 0x3FFF0000UL :
1728 	    /* but otherwise, only 75% */
1729 	    ((i * 3) / 4);
1730 	tp->tbls = ntblp;
1731 	if (otblp == NULL)
1732 		return;
1733 
1734 	mask = i - 1;
1735 	for (i = 0; i < osize; i++)
1736 		if ((tblp = otblp[i]) != NULL) {
1737 			if ((tblp->flag & DEFINED)) {
1738 				/* search for free hash table slot */
1739 				j = perturb = tblp->ua.hval;
1740 				goto find_first_empty_slot;
1741  find_next_empty_slot:
1742 				j = (j << 2) + j + perturb + 1;
1743 				perturb >>= PERTURB_SHIFT;
1744  find_first_empty_slot:
1745 				pp = &ntblp[j & mask];
1746 				if (*pp != NULL)
1747 					goto find_next_empty_slot;
1748 				/* found an empty hash table slot */
1749 				*pp = tblp;
1750 				tp->nfree--;
1751 			} else if (!(tblp->flag & FINUSE)) {
1752 				afree(tblp, tp->areap);
1753 			}
1754 		}
1755 	afree(otblp, tp->areap);
1756 }
1757 
1758 void
ktinit(Area * ap,struct table * tp,uint8_t initshift)1759 ktinit(Area *ap, struct table *tp, uint8_t initshift)
1760 {
1761 	tp->areap = ap;
1762 	tp->tbls = NULL;
1763 	tp->tshift = ((initshift > INIT_TBLSHIFT) ?
1764 	    initshift : INIT_TBLSHIFT) - 1;
1765 	tgrow(tp);
1766 }
1767 
1768 /* table, name (key) to search for, hash(name), rv pointer to tbl ptr */
1769 struct tbl *
ktscan(struct table * tp,const char * name,uint32_t h,struct tbl *** ppp)1770 ktscan(struct table *tp, const char *name, uint32_t h, struct tbl ***ppp)
1771 {
1772 	size_t j, perturb, mask;
1773 	struct tbl **pp, *p;
1774 
1775 	mask = ((size_t)1 << (tp->tshift)) - 1;
1776 	/* search for hash table slot matching name */
1777 	j = perturb = h;
1778 	goto find_first_slot;
1779  find_next_slot:
1780 	j = (j << 2) + j + perturb + 1;
1781 	perturb >>= PERTURB_SHIFT;
1782  find_first_slot:
1783 	pp = &tp->tbls[j & mask];
1784 	if ((p = *pp) != NULL && (p->ua.hval != h || !(p->flag & DEFINED) ||
1785 	    strcmp(p->name, name)))
1786 		goto find_next_slot;
1787 	/* p == NULL if not found, correct found entry otherwise */
1788 	if (ppp)
1789 		*ppp = pp;
1790 	return (p);
1791 }
1792 
1793 /* table, name (key) to enter, hash(n) */
1794 struct tbl *
ktenter(struct table * tp,const char * n,uint32_t h)1795 ktenter(struct table *tp, const char *n, uint32_t h)
1796 {
1797 	struct tbl **pp, *p;
1798 	size_t len;
1799 
1800  Search:
1801 	if ((p = ktscan(tp, n, h, &pp)))
1802 		return (p);
1803 
1804 	if (tp->nfree == 0) {
1805 		/* too full */
1806 		tgrow(tp);
1807 		goto Search;
1808 	}
1809 
1810 	/* create new tbl entry */
1811 	len = strlen(n);
1812 	checkoktoadd(len, offsetof(struct tbl, name[0]) + 1);
1813 	p = alloc(offsetof(struct tbl, name[0]) + ++len, tp->areap);
1814 	p->flag = 0;
1815 	p->type = 0;
1816 	p->areap = tp->areap;
1817 	p->ua.hval = h;
1818 	p->u2.field = 0;
1819 	p->u.array = NULL;
1820 	memcpy(p->name, n, len);
1821 
1822 	/* enter in tp->tbls */
1823 	tp->nfree--;
1824 	*pp = p;
1825 	return (p);
1826 }
1827 
1828 void
ktwalk(struct tstate * ts,struct table * tp)1829 ktwalk(struct tstate *ts, struct table *tp)
1830 {
1831 	ts->left = (size_t)1 << (tp->tshift);
1832 	ts->next = tp->tbls;
1833 }
1834 
1835 struct tbl *
ktnext(struct tstate * ts)1836 ktnext(struct tstate *ts)
1837 {
1838 	while (--ts->left >= 0) {
1839 		struct tbl *p = *ts->next++;
1840 		if (p != NULL && (p->flag & DEFINED))
1841 			return (p);
1842 	}
1843 	return (NULL);
1844 }
1845 
1846 static int
tnamecmp(const void * p1,const void * p2)1847 tnamecmp(const void *p1, const void *p2)
1848 {
1849 	const struct tbl *a = *((const struct tbl * const *)p1);
1850 	const struct tbl *b = *((const struct tbl * const *)p2);
1851 
1852 	return (strcmp(a->name, b->name));
1853 }
1854 
1855 struct tbl **
ktsort(struct table * tp)1856 ktsort(struct table *tp)
1857 {
1858 	size_t i;
1859 	struct tbl **p, **sp, **dp;
1860 
1861 	/*
1862 	 * since the table is never entirely full, no need to reserve
1863 	 * additional space for the trailing NULL appended below
1864 	 */
1865 	i = (size_t)1 << (tp->tshift);
1866 	p = alloc2(i, sizeof(struct tbl *), ATEMP);
1867 	sp = tp->tbls;		/* source */
1868 	dp = p;			/* dest */
1869 	while (i--)
1870 		if ((*dp = *sp++) != NULL && (((*dp)->flag & DEFINED) ||
1871 		    ((*dp)->flag & ARRAY)))
1872 			dp++;
1873 	qsort(p, (i = dp - p), sizeof(struct tbl *), tnamecmp);
1874 	p[i] = NULL;
1875 	return (p);
1876 }
1877 
1878 #ifdef SIGWINCH
1879 static void
x_sigwinch(int sig MKSH_A_UNUSED)1880 x_sigwinch(int sig MKSH_A_UNUSED)
1881 {
1882 	/* this runs inside interrupt context, with errno saved */
1883 
1884 	got_winch = 1;
1885 }
1886 #endif
1887 
1888 #ifdef DF
1889 void
DF(const char * fmt,...)1890 DF(const char *fmt, ...)
1891 {
1892 	va_list args;
1893 	struct timeval tv;
1894 	mirtime_mjd mjd;
1895 
1896 	mksh_lockfd(shl_dbg_fd);
1897 	mksh_TIME(tv);
1898 	timet2mjd(&mjd, tv.tv_sec);
1899 	shf_fprintf(shl_dbg, "[%02u:%02u:%02u (%u) %u.%06u] ",
1900 	    (unsigned)mjd.sec / 3600, ((unsigned)mjd.sec / 60) % 60,
1901 	    (unsigned)mjd.sec % 60, (unsigned)getpid(),
1902 	    (unsigned)tv.tv_sec, (unsigned)tv.tv_usec);
1903 	va_start(args, fmt);
1904 	shf_vfprintf(shl_dbg, fmt, args);
1905 	va_end(args);
1906 	shf_putc('\n', shl_dbg);
1907 	shf_flush(shl_dbg);
1908 	mksh_unlkfd(shl_dbg_fd);
1909 }
1910 #endif
1911 
1912 void
x_mkraw(int fd,mksh_ttyst * ocb,bool forread)1913 x_mkraw(int fd, mksh_ttyst *ocb, bool forread)
1914 {
1915 	mksh_ttyst cb;
1916 
1917 	if (ocb)
1918 		mksh_tcget(fd, ocb);
1919 	else
1920 		ocb = &tty_state;
1921 
1922 	cb = *ocb;
1923 	if (forread) {
1924 		cb.c_lflag &= ~(ICANON) | ECHO;
1925 	} else {
1926 		cb.c_iflag &= ~(INLCR | ICRNL);
1927 		cb.c_lflag &= ~(ISIG | ICANON | ECHO);
1928 	}
1929 #if defined(VLNEXT) && defined(_POSIX_VDISABLE)
1930 	/* OSF/1 processes lnext when ~icanon */
1931 	cb.c_cc[VLNEXT] = _POSIX_VDISABLE;
1932 #endif
1933 	/* SunOS 4.1.x & OSF/1 processes discard(flush) when ~icanon */
1934 #if defined(VDISCARD) && defined(_POSIX_VDISABLE)
1935 	cb.c_cc[VDISCARD] = _POSIX_VDISABLE;
1936 #endif
1937 	cb.c_cc[VTIME] = 0;
1938 	cb.c_cc[VMIN] = 1;
1939 
1940 	mksh_tcset(fd, &cb);
1941 }
1942