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1 /*	$OpenBSD: main.c,v 1.51 2012/09/10 01:25:30 tedu 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 1.260 2013/02/10 21:42:16 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", "RANDOM", "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 	"suspend=kill -STOP $$",
79 #endif
80 	"autoload=typeset -fu",
81 	"functions=typeset -f",
82 	"history=fc -l",
83 	"nameref=typeset -n",
84 	"nohup=nohup ",
85 	Tr_fc_e_dash,
86 	"source=PATH=$PATH:. command .",
87 	"login=exec login",
88 	NULL,
89 	 /* this is what AT&T ksh seems to track, with the addition of emacs */
90 	Talias, "-tU",
91 	"cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
92 	"make", "mv", "pr", "rm", "sed", "sh", "vi", "who", NULL,
93 	NULL
94 };
95 
96 static const char *restr_com[] = {
97 	Ttypeset, "-r", "PATH", "ENV", "SHELL", NULL
98 };
99 
100 static bool initio_done;
101 
102 /* top-level parsing and execution environment */
103 static struct env env;
104 struct env *e = &env;
105 
106 static mksh_uari_t
rndsetup(void)107 rndsetup(void)
108 {
109 	register uint32_t h;
110 	struct {
111 		ALLOC_ITEM alloc_INT;
112 		void *dataptr, *stkptr, *mallocptr;
113 #if defined(__GLIBC__) && (__GLIBC__ >= 2)
114 		sigjmp_buf jbuf;
115 #endif
116 		struct timeval tv;
117 	} *bufptr;
118 	char *cp;
119 
120 	cp = alloc(sizeof(*bufptr) - ALLOC_SIZE, APERM);
121 #ifdef DEBUG
122 	/* clear the allocated space, for valgrind */
123 	memset(cp, 0, sizeof(*bufptr) - ALLOC_SIZE);
124 #endif
125 	/* undo what alloc() did to the malloc result address */
126 	bufptr = (void *)(cp - ALLOC_SIZE);
127 	/* PIE or something similar provides us with deltas here */
128 	bufptr->dataptr = &rndsetupstate;
129 	/* ASLR in at least Windows, Linux, some BSDs */
130 	bufptr->stkptr = &bufptr;
131 	/* randomised malloc in BSD (and possibly others) */
132 	bufptr->mallocptr = bufptr;
133 #if defined(__GLIBC__) && (__GLIBC__ >= 2)
134 	/* glibc pointer guard */
135 	sigsetjmp(bufptr->jbuf, 1);
136 #endif
137 	/* introduce variation (and yes, second arg MBZ for portability) */
138 	mksh_TIME(bufptr->tv);
139 
140 	NZATInit(h);
141 	/* variation through pid, ppid, and the works */
142 	NZATUpdateMem(h, &rndsetupstate, sizeof(rndsetupstate));
143 	/* some variation, some possibly entropy, depending on OE */
144 	NZATUpdateMem(h, bufptr, sizeof(*bufptr));
145 	NZAATFinish(h);
146 
147 	afree(cp, APERM);
148 	return ((mksh_uari_t)h);
149 }
150 
151 void
chvt_reinit(void)152 chvt_reinit(void)
153 {
154 	kshpid = procpid = getpid();
155 	ksheuid = geteuid();
156 	kshpgrp = getpgrp();
157 	kshppid = getppid();
158 }
159 
160 static const char *empty_argv[] = {
161 	"mksh", NULL
162 };
163 
164 static uint8_t
isuc(const char * cx)165 isuc(const char *cx) {
166 	char *cp, *x;
167 	uint8_t rv = 0;
168 
169 	if (!cx || !*cx)
170 		return (0);
171 
172 	/* uppercase a string duplicate */
173 	strdupx(x, cx, ATEMP);
174 	cp = x;
175 	while ((*cp = ksh_toupper(*cp)))
176 		++cp;
177 
178 	/* check for UTF-8 */
179 	if (strstr(x, "UTF-8") || strstr(x, "UTF8"))
180 		rv = 1;
181 
182 	/* free copy and out */
183 	afree(x, ATEMP);
184 	return (rv);
185 }
186 
187 static int
main_init(int argc,const char * argv[],Source ** sp,struct block ** lp)188 main_init(int argc, const char *argv[], Source **sp, struct block **lp)
189 {
190 	int argi, i;
191 	Source *s = NULL;
192 	struct block *l;
193 	unsigned char restricted, errexit, utf_flag;
194 	char *cp;
195 	const char *ccp, **wp;
196 	struct tbl *vp;
197 	struct stat s_stdin;
198 #if !defined(_PATH_DEFPATH) && defined(_CS_PATH)
199 	ssize_t k;
200 #endif
201 
202 	/* do things like getpgrp() et al. */
203 	chvt_reinit();
204 
205 	/* make sure argv[] is sane */
206 	if (!*argv) {
207 		argv = empty_argv;
208 		argc = 1;
209 	}
210 	kshname = argv[0];
211 
212 	/* initialise permanent Area */
213 	ainit(&aperm);
214 
215 	/* set up base environment */
216 	env.type = E_NONE;
217 	ainit(&env.area);
218 	/* set up global l->vars and l->funs */
219 	newblock();
220 
221 	/* Do this first so output routines (eg, errorf, shellf) can work */
222 	initio();
223 
224 	/* determine the basename (without '-' or path) of the executable */
225 	ccp = kshname;
226 	goto begin_parse_kshname;
227 	while ((i = ccp[argi++])) {
228 		if (i == '/') {
229 			ccp += argi;
230  begin_parse_kshname:
231 			argi = 0;
232 			if (*ccp == '-')
233 				++ccp;
234 		}
235 	}
236 	if (!*ccp)
237 		ccp = empty_argv[0];
238 
239 	/* define built-in commands and see if we were called as one */
240 	ktinit(APERM, &builtins,
241 	    /* currently up to 50 builtins: 75% of 128 = 2^7 */
242 	    7);
243 	for (i = 0; mkshbuiltins[i].name != NULL; i++)
244 		if (!strcmp(ccp, builtin(mkshbuiltins[i].name,
245 		    mkshbuiltins[i].func)))
246 			Flag(FAS_BUILTIN) = 1;
247 
248 	if (!Flag(FAS_BUILTIN)) {
249 		/* check for -T option early */
250 		argi = parse_args(argv, OF_FIRSTTIME, NULL);
251 		if (argi < 0)
252 			return (1);
253 
254 #ifdef MKSH_BINSHREDUCED
255 		/* set FSH if we're called as -sh or /bin/sh or so */
256 		if (!strcmp(ccp, "sh"))
257 			change_flag(FSH, OF_FIRSTTIME, true);
258 #endif
259 	}
260 
261 	initvar();
262 
263 	initctypes();
264 
265 	inittraps();
266 
267 	coproc_init();
268 
269 	/* set up variable and command dictionaries */
270 	ktinit(APERM, &taliases, 0);
271 	ktinit(APERM, &aliases, 0);
272 #ifndef MKSH_NOPWNAM
273 	ktinit(APERM, &homedirs, 0);
274 #endif
275 
276 	/* define shell keywords */
277 	initkeywords();
278 
279 	init_histvec();
280 
281 	/* initialise tty size before importing environment */
282 	change_winsz();
283 
284 #ifdef _PATH_DEFPATH
285 	def_path = _PATH_DEFPATH;
286 #else
287 #ifdef _CS_PATH
288 	if ((k = confstr(_CS_PATH, NULL, 0)) > 0 &&
289 	    confstr(_CS_PATH, cp = alloc(k + 1, APERM), k + 1) == k + 1)
290 		def_path = cp;
291 	else
292 #endif
293 		/*
294 		 * this is uniform across all OSes unless it
295 		 * breaks somewhere; don't try to optimise,
296 		 * e.g. add stuff for Interix or remove /usr
297 		 * for HURD, because e.g. Debian GNU/HURD is
298 		 * "keeping a regular /usr"; this is supposed
299 		 * to be a sane 'basic' default PATH
300 		 */
301 		def_path = "/bin:/usr/bin:/sbin:/usr/sbin";
302 #endif
303 
304 	/*
305 	 * Set PATH to def_path (will set the path global variable).
306 	 * (import of environment below will probably change this setting).
307 	 */
308 	vp = global("PATH");
309 	/* setstr can't fail here */
310 	setstr(vp, def_path, KSH_RETURN_ERROR);
311 
312 	/*
313 	 * Turn on nohup by default for now - will change to off
314 	 * by default once people are aware of its existence
315 	 * (AT&T ksh does not have a nohup option - it always sends
316 	 * the hup).
317 	 */
318 	Flag(FNOHUP) = 1;
319 
320 	/*
321 	 * Turn on brace expansion by default. AT&T kshs that have
322 	 * alternation always have it on.
323 	 */
324 	Flag(FBRACEEXPAND) = 1;
325 
326 #ifndef MKSH_NO_CMDLINE_EDITING
327 	/*
328 	 * Set edit mode to emacs by default, may be overridden
329 	 * by the environment or the user. Also, we want tab completion
330 	 * on in vi by default.
331 	 */
332 	change_flag(FEMACS, OF_SPECIAL, true);
333 #if !MKSH_S_NOVI
334 	Flag(FVITABCOMPLETE) = 1;
335 #endif
336 #endif
337 
338 	/* import environment */
339 	if (environ != NULL)
340 		for (wp = (const char **)environ; *wp != NULL; wp++)
341 			typeset(*wp, IMPORT | EXPORT, 0, 0, 0);
342 
343 	/* for security */
344 	typeset(initifs, 0, 0, 0, 0);
345 
346 	/* assign default shell variable values */
347 	substitute(initsubs, 0);
348 
349 	/* Figure out the current working directory and set $PWD */
350 	vp = global("PWD");
351 	cp = str_val(vp);
352 	/* Try to use existing $PWD if it is valid */
353 	set_current_wd((cp[0] == '/' && test_eval(NULL, TO_FILEQ, cp, ".",
354 	    true)) ? cp : NULL);
355 	if (current_wd[0])
356 		simplify_path(current_wd);
357 	/* Only set pwd if we know where we are or if it had a bogus value */
358 	if (current_wd[0] || *cp)
359 		/* setstr can't fail here */
360 		setstr(vp, current_wd, KSH_RETURN_ERROR);
361 
362 	for (wp = initcoms; *wp != NULL; wp++) {
363 		shcomexec(wp);
364 		while (*wp != NULL)
365 			wp++;
366 	}
367 	setint_n(global("OPTIND"), 1, 10);
368 
369 	kshuid = getuid();
370 	kshgid = getgid();
371 	kshegid = getegid();
372 
373 	safe_prompt = ksheuid ? "$ " : "# ";
374 	vp = global("PS1");
375 	/* Set PS1 if unset or we are root and prompt doesn't contain a # */
376 	if (!(vp->flag & ISSET) ||
377 	    (!ksheuid && !strchr(str_val(vp), '#')))
378 		/* setstr can't fail here */
379 		setstr(vp, safe_prompt, KSH_RETURN_ERROR);
380 	setint_n((vp = global("BASHPID")), 0, 10);
381 	vp->flag |= INT_U;
382 	setint_n((vp = global("PGRP")), (mksh_uari_t)kshpgrp, 10);
383 	vp->flag |= INT_U;
384 	setint_n((vp = global("PPID")), (mksh_uari_t)kshppid, 10);
385 	vp->flag |= INT_U;
386 	setint_n((vp = global("USER_ID")), (mksh_uari_t)ksheuid, 10);
387 	vp->flag |= INT_U;
388 	setint_n((vp = global("KSHUID")), (mksh_uari_t)kshuid, 10);
389 	vp->flag |= INT_U;
390 	setint_n((vp = global("KSHEGID")), (mksh_uari_t)kshegid, 10);
391 	vp->flag |= INT_U;
392 	setint_n((vp = global("KSHGID")), (mksh_uari_t)kshgid, 10);
393 	vp->flag |= INT_U;
394 	setint_n((vp = global("RANDOM")), rndsetup(), 10);
395 	vp->flag |= INT_U;
396 	setint_n((vp_pipest = global("PIPESTATUS")), 0, 10);
397 
398 	/* Set this before parsing arguments */
399 	Flag(FPRIVILEGED) = kshuid != ksheuid || kshgid != kshegid;
400 
401 	/* this to note if monitor is set on command line (see below) */
402 #ifndef MKSH_UNEMPLOYED
403 	Flag(FMONITOR) = 127;
404 #endif
405 	/* this to note if utf-8 mode is set on command line (see below) */
406 	UTFMODE = 2;
407 
408 	if (!Flag(FAS_BUILTIN)) {
409 		argi = parse_args(argv, OF_CMDLINE, NULL);
410 		if (argi < 0)
411 			return (1);
412 	}
413 
414 #ifdef DEBUG
415 	/* test wraparound of arithmetic types */
416 	{
417 		volatile long xl;
418 		volatile unsigned long xul;
419 		volatile int xi;
420 		volatile unsigned int xui;
421 		volatile mksh_ari_t xa;
422 		volatile mksh_uari_t xua, xua2;
423 		volatile uint8_t xc;
424 
425 		xa = 2147483647;
426 		xua = 2147483647;
427 		++xa;
428 		++xua;
429 		xua2 = xa;
430 		xl = xa;
431 		xul = xua;
432 		xa = 0;
433 		xua = 0;
434 		--xa;
435 		--xua;
436 		xi = xa;
437 		xui = xua;
438 		xa = -1;
439 		xua = xa;
440 		++xa;
441 		++xua;
442 		xc = 0;
443 		--xc;
444 		if ((xua2 != 2147483648UL) ||
445 		    (xl != -2147483648L) || (xul != 2147483648UL) ||
446 		    (xi != -1) || (xui != 4294967295U) ||
447 		    (xa != 0) || (xua != 0) || (xc != 255))
448 			errorf("integer wraparound test failed");
449 	}
450 #endif
451 
452 	/* process this later only, default to off (hysterical raisins) */
453 	utf_flag = UTFMODE;
454 	UTFMODE = 0;
455 
456 	if (Flag(FAS_BUILTIN)) {
457 		/* auto-detect from environment variables, always */
458 		utf_flag = 3;
459 	} else if (Flag(FCOMMAND)) {
460 		s = pushs(SSTRINGCMDLINE, ATEMP);
461 		if (!(s->start = s->str = argv[argi++]))
462 			errorf("%s %s", "-c", "requires an argument");
463 #if !defined(MKSH_SMALL)
464 		while (*s->str) {
465 			if (*s->str != ' ' && ctype(*s->str, C_QUOTE))
466 				break;
467 			s->str++;
468 		}
469 		if (!*s->str)
470 			s->flags |= SF_MAYEXEC;
471 		s->str = s->start;
472 #endif
473 #ifdef MKSH_MIDNIGHTBSD01ASH_COMPAT
474 		/* compatibility to MidnightBSD 0.1 /bin/sh (kludge) */
475 		if (Flag(FSH) && argv[argi] && !strcmp(argv[argi], "--"))
476 			++argi;
477 #endif
478 		if (argv[argi])
479 			kshname = argv[argi++];
480 	} else if (argi < argc && !Flag(FSTDIN)) {
481 		s = pushs(SFILE, ATEMP);
482 		s->file = argv[argi++];
483 		s->u.shf = shf_open(s->file, O_RDONLY, 0,
484 		    SHF_MAPHI | SHF_CLEXEC);
485 		if (s->u.shf == NULL) {
486 			shl_stdout_ok = false;
487 			warningf(true, "%s: %s", s->file, cstrerror(errno));
488 			/* mandated by SUSv4 */
489 			exstat = 127;
490 			unwind(LERROR);
491 		}
492 		kshname = s->file;
493 	} else {
494 		Flag(FSTDIN) = 1;
495 		s = pushs(SSTDIN, ATEMP);
496 		s->file = "<stdin>";
497 		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
498 		    NULL);
499 		if (isatty(0) && isatty(2)) {
500 			Flag(FTALKING) = Flag(FTALKING_I) = 1;
501 			/* The following only if isatty(0) */
502 			s->flags |= SF_TTY;
503 			s->u.shf->flags |= SHF_INTERRUPT;
504 			s->file = NULL;
505 		}
506 	}
507 
508 	/* this bizarreness is mandated by POSIX */
509 	if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
510 	    Flag(FTALKING))
511 		reset_nonblock(0);
512 
513 	/* initialise job control */
514 	j_init();
515 	/* do this after j_init() which calls tty_init_state() */
516 	if (Flag(FTALKING)) {
517 		if (utf_flag == 2) {
518 #ifndef MKSH_ASSUME_UTF8
519 			/* auto-detect from locale or environment */
520 			utf_flag = 4;
521 #elif MKSH_ASSUME_UTF8
522 			utf_flag = 1;
523 #else
524 			/* always disable UTF-8 (for interactive) */
525 			utf_flag = 0;
526 #endif
527 		}
528 #ifndef MKSH_NO_CMDLINE_EDITING
529 		x_init();
530 #endif
531 	}
532 
533 #ifdef SIGWINCH
534 	sigtraps[SIGWINCH].flags |= TF_SHELL_USES;
535 	setsig(&sigtraps[SIGWINCH], x_sigwinch,
536 	    SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
537 #endif
538 
539 	l = e->loc;
540 	if (Flag(FAS_BUILTIN)) {
541 		l->argc = argc;
542 		l->argv = argv;
543 		l->argv[0] = ccp;
544 	} else {
545 		l->argc = argc - argi;
546 		/*
547 		 * allocate a new array because otherwise, when we modify
548 		 * it in-place, ps(1) output changes; the meaning of argc
549 		 * here is slightly different as it excludes kshname, and
550 		 * we add a trailing NULL sentinel as well
551 		 */
552 		l->argv = alloc2(l->argc + 2, sizeof(void *), APERM);
553 		l->argv[0] = kshname;
554 		memcpy(&l->argv[1], &argv[argi], l->argc * sizeof(void *));
555 		l->argv[l->argc + 1] = NULL;
556 		getopts_reset(1);
557 	}
558 
559 	/* divine the initial state of the utf8-mode Flag */
560 	ccp = null;
561 	switch (utf_flag) {
562 
563 	/* auto-detect from locale or environment */
564 	case 4:
565 #if HAVE_SETLOCALE_CTYPE
566 		ccp = setlocale(LC_CTYPE, "");
567 #if HAVE_LANGINFO_CODESET
568 		if (!isuc(ccp))
569 			ccp = nl_langinfo(CODESET);
570 #endif
571 		if (!isuc(ccp))
572 			ccp = null;
573 		/* FALLTHROUGH */
574 #endif
575 
576 	/* auto-detect from environment */
577 	case 3:
578 		/* these were imported from environ earlier */
579 		if (ccp == null)
580 			ccp = str_val(global("LC_ALL"));
581 		if (ccp == null)
582 			ccp = str_val(global("LC_CTYPE"));
583 		if (ccp == null)
584 			ccp = str_val(global("LANG"));
585 		UTFMODE = isuc(ccp);
586 		break;
587 
588 	/* not set on command line, not FTALKING */
589 	case 2:
590 	/* unknown values */
591 	default:
592 		utf_flag = 0;
593 		/* FALLTHROUGH */
594 
595 	/* known values */
596 	case 1:
597 	case 0:
598 		UTFMODE = utf_flag;
599 		break;
600 	}
601 
602 	/* Disable during .profile/ENV reading */
603 	restricted = Flag(FRESTRICTED);
604 	Flag(FRESTRICTED) = 0;
605 	errexit = Flag(FERREXIT);
606 	Flag(FERREXIT) = 0;
607 
608 	/*
609 	 * Do this before profile/$ENV so that if it causes problems in them,
610 	 * user will know why things broke.
611 	 */
612 	if (!current_wd[0] && Flag(FTALKING))
613 		warningf(false, "can't determine current directory");
614 
615 	if (Flag(FLOGIN)) {
616 		include(MKSH_SYSTEM_PROFILE, 0, NULL, true);
617 		if (!Flag(FPRIVILEGED))
618 			include(substitute("$HOME/.profile", 0), 0,
619 			    NULL, true);
620 	}
621 	if (Flag(FPRIVILEGED))
622 		include(MKSH_SUID_PROFILE, 0, NULL, true);
623 	else if (Flag(FTALKING)) {
624 		char *env_file;
625 
626 		/* include $ENV */
627 		env_file = substitute(substitute("${ENV:-" MKSHRC_PATH "}", 0),
628 		    DOTILDE);
629 		if (*env_file != '\0')
630 			include(env_file, 0, NULL, true);
631 	}
632 
633 	if (restricted) {
634 		shcomexec(restr_com);
635 		/* After typeset command... */
636 		Flag(FRESTRICTED) = 1;
637 	}
638 	Flag(FERREXIT) = errexit;
639 
640 	if (Flag(FTALKING) && s)
641 		hist_init(s);
642 	else
643 		/* set after ENV */
644 		Flag(FTRACKALL) = 1;
645 
646 	alarm_init();
647 
648 	*sp = s;
649 	*lp = l;
650 	return (0);
651 }
652 
653 /* this indirection barrier reduces stack usage during normal operation */
654 
655 int
main(int argc,const char * argv[])656 main(int argc, const char *argv[])
657 {
658 	int rv;
659 	Source *s;
660 	struct block *l;
661 
662 	if ((rv = main_init(argc, argv, &s, &l)) == 0) {
663 		if (Flag(FAS_BUILTIN)) {
664 			rv = shcomexec(l->argv);
665 		} else {
666 			shell(s, true);
667 			/* NOTREACHED */
668 		}
669 	}
670 	return (rv);
671 }
672 
673 int
include(const char * name,int argc,const char ** argv,bool intr_ok)674 include(const char *name, int argc, const char **argv, bool intr_ok)
675 {
676 	Source *volatile s = NULL;
677 	struct shf *shf;
678 	const char **volatile old_argv;
679 	volatile int old_argc;
680 	int i;
681 
682 	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI | SHF_CLEXEC);
683 	if (shf == NULL)
684 		return (-1);
685 
686 	if (argv) {
687 		old_argv = e->loc->argv;
688 		old_argc = e->loc->argc;
689 	} else {
690 		old_argv = NULL;
691 		old_argc = 0;
692 	}
693 	newenv(E_INCL);
694 	if ((i = kshsetjmp(e->jbuf))) {
695 		quitenv(s ? s->u.shf : NULL);
696 		if (old_argv) {
697 			e->loc->argv = old_argv;
698 			e->loc->argc = old_argc;
699 		}
700 		switch (i) {
701 		case LRETURN:
702 		case LERROR:
703 			/* see below */
704 			return (exstat & 0xFF);
705 		case LINTR:
706 			/*
707 			 * intr_ok is set if we are including .profile or $ENV.
708 			 * If user ^Cs out, we don't want to kill the shell...
709 			 */
710 			if (intr_ok && ((exstat & 0xFF) - 128) != SIGTERM)
711 				return (1);
712 			/* FALLTHROUGH */
713 		case LEXIT:
714 		case LLEAVE:
715 		case LSHELL:
716 			unwind(i);
717 			/* NOTREACHED */
718 		default:
719 			internal_errorf("%s %d", "include", i);
720 			/* NOTREACHED */
721 		}
722 	}
723 	if (argv) {
724 		e->loc->argv = argv;
725 		e->loc->argc = argc;
726 	}
727 	s = pushs(SFILE, ATEMP);
728 	s->u.shf = shf;
729 	strdupx(s->file, name, ATEMP);
730 	i = shell(s, false);
731 	quitenv(s->u.shf);
732 	if (old_argv) {
733 		e->loc->argv = old_argv;
734 		e->loc->argc = old_argc;
735 	}
736 	/* & 0xff to ensure value not -1 */
737 	return (i & 0xFF);
738 }
739 
740 /* spawn a command into a shell optionally keeping track of the line number */
741 int
command(const char * comm,int line)742 command(const char *comm, int line)
743 {
744 	Source *s;
745 
746 	s = pushs(SSTRING, ATEMP);
747 	s->start = s->str = comm;
748 	s->line = line;
749 	return (shell(s, false));
750 }
751 
752 /*
753  * run the commands from the input source, returning status.
754  */
755 int
shell(Source * volatile s,volatile bool toplevel)756 shell(Source * volatile s, volatile bool toplevel)
757 {
758 	struct op *t;
759 	volatile bool wastty = tobool(s->flags & SF_TTY);
760 	volatile uint8_t attempts = 13;
761 	volatile bool interactive = Flag(FTALKING) && toplevel;
762 	volatile bool sfirst = true;
763 	Source *volatile old_source = source;
764 	int i;
765 
766 	newenv(E_PARSE);
767 	if (interactive)
768 		really_exit = false;
769 	switch ((i = kshsetjmp(e->jbuf))) {
770 	case 0:
771 		break;
772 	case LINTR:
773 		/* we get here if SIGINT not caught or ignored */
774 	case LERROR:
775 	case LSHELL:
776 		if (interactive) {
777 			if (i == LINTR)
778 				shellf("\n");
779 			/*
780 			 * Reset any eof that was read as part of a
781 			 * multiline command.
782 			 */
783 			if (Flag(FIGNOREEOF) && s->type == SEOF && wastty)
784 				s->type = SSTDIN;
785 			/*
786 			 * Used by exit command to get back to
787 			 * top level shell. Kind of strange since
788 			 * interactive is set if we are reading from
789 			 * a tty, but to have stopped jobs, one only
790 			 * needs FMONITOR set (not FTALKING/SF_TTY)...
791 			 */
792 			/* toss any input we have so far */
793 			yyrecursive_pop(true);
794 			s->start = s->str = null;
795 			retrace_info = NULL;
796 			herep = heres;
797 			break;
798 		}
799 		/* FALLTHROUGH */
800 	case LEXIT:
801 	case LLEAVE:
802 	case LRETURN:
803 		source = old_source;
804 		quitenv(NULL);
805 		/* keep on going */
806 		unwind(i);
807 		/* NOTREACHED */
808 	default:
809 		source = old_source;
810 		quitenv(NULL);
811 		internal_errorf("%s %d", "shell", i);
812 		/* NOTREACHED */
813 	}
814 	while (/* CONSTCOND */ 1) {
815 		if (trap)
816 			runtraps(0);
817 
818 		if (s->next == NULL) {
819 			if (Flag(FVERBOSE))
820 				s->flags |= SF_ECHO;
821 			else
822 				s->flags &= ~SF_ECHO;
823 		}
824 		if (interactive) {
825 			j_notify();
826 			set_prompt(PS1, s);
827 		}
828 		t = compile(s, sfirst);
829 		sfirst = false;
830 		if (!t)
831 			goto source_no_tree;
832 		if (t->type == TEOF) {
833 			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
834 				shellf("Use 'exit' to leave mksh\n");
835 				s->type = SSTDIN;
836 			} else if (wastty && !really_exit &&
837 			    j_stopped_running()) {
838 				really_exit = true;
839 				s->type = SSTDIN;
840 			} else {
841 				/*
842 				 * this for POSIX which says EXIT traps
843 				 * shall be taken in the environment
844 				 * immediately after the last command
845 				 * executed.
846 				 */
847 				if (toplevel)
848 					unwind(LEXIT);
849 				break;
850 			}
851 		}
852 #if !defined(MKSH_SMALL)
853 		  else if ((s->flags & SF_MAYEXEC) && t->type == TCOM)
854 			t->u.evalflags |= DOTCOMEXEC;
855 #endif
856 		if (!Flag(FNOEXEC) || (s->flags & SF_TTY))
857 			exstat = execute(t, 0, NULL) & 0xFF;
858 
859 		if (t->type != TEOF && interactive && really_exit)
860 			really_exit = false;
861 
862  source_no_tree:
863 		reclaim();
864 	}
865 	quitenv(NULL);
866 	source = old_source;
867 	return (exstat & 0xFF);
868 }
869 
870 /* return to closest error handler or shell(), exit if none found */
871 /* note: i MUST NOT be 0 */
872 void
unwind(int i)873 unwind(int i)
874 {
875 	/*
876 	 * This is a kludge. We need to restore everything that was
877 	 * changed in the new environment, see cid 1005090337C7A669439
878 	 * and 10050903386452ACBF1, but fail to even save things most of
879 	 * the time. funcs.c:c_eval() changes FERREXIT temporarily to 0,
880 	 * which needs to be restored thus (related to Debian #696823).
881 	 * We did not save the shell flags, so we use a special or'd
882 	 * value here... this is mostly to clean up behind *other*
883 	 * callers of unwind(LERROR) here; exec.c has the regular case.
884 	 */
885 	if (Flag(FERREXIT) & 0x80) {
886 		/* GNU bash does not run this trapsig */
887 		trapsig(ksh_SIGERR);
888 		Flag(FERREXIT) &= ~0x80;
889 	}
890 
891 	/* ordering for EXIT vs ERR is a bit odd (this is what AT&T ksh does) */
892 	if (i == LEXIT ||
893 	    ((i == LERROR || i == LINTR) && sigtraps[ksh_SIGEXIT].trap)) {
894 		++trap_nested;
895 		runtrap(&sigtraps[ksh_SIGEXIT], trap_nested == 1);
896 		--trap_nested;
897 		i = LLEAVE;
898 	} else if (Flag(FERREXIT) == 1 && (i == LERROR || i == LINTR)) {
899 		++trap_nested;
900 		runtrap(&sigtraps[ksh_SIGERR], trap_nested == 1);
901 		--trap_nested;
902 		i = LLEAVE;
903 	}
904 
905 	while (/* CONSTCOND */ 1) {
906 		switch (e->type) {
907 		case E_PARSE:
908 		case E_FUNC:
909 		case E_INCL:
910 		case E_LOOP:
911 		case E_ERRH:
912 			kshlongjmp(e->jbuf, i);
913 			/* NOTREACHED */
914 		case E_NONE:
915 			if (i == LINTR)
916 				e->flags |= EF_FAKE_SIGDIE;
917 			/* FALLTHROUGH */
918 		default:
919 			quitenv(NULL);
920 		}
921 	}
922 }
923 
924 void
newenv(int type)925 newenv(int type)
926 {
927 	struct env *ep;
928 	char *cp;
929 
930 	/*
931 	 * struct env includes ALLOC_ITEM for alignment constraints
932 	 * so first get the actually used memory, then assign it
933 	 */
934 	cp = alloc(sizeof(struct env) - ALLOC_SIZE, ATEMP);
935 	/* undo what alloc() did to the malloc result address */
936 	ep = (void *)(cp - ALLOC_SIZE);
937 	/* initialise public members of struct env (not the ALLOC_ITEM) */
938 	ainit(&ep->area);
939 	ep->oenv = e;
940 	ep->loc = e->loc;
941 	ep->savefd = NULL;
942 	ep->temps = NULL;
943 	ep->yyrecursive_statep = NULL;
944 	ep->type = type;
945 	ep->flags = 0;
946 	/* jump buffer is invalid because flags == 0 */
947 	e = ep;
948 }
949 
950 void
quitenv(struct shf * shf)951 quitenv(struct shf *shf)
952 {
953 	struct env *ep = e;
954 	char *cp;
955 	int fd;
956 
957 	yyrecursive_pop(true);
958 	while (ep->oenv && ep->oenv->loc != ep->loc)
959 		popblock();
960 	if (ep->savefd != NULL) {
961 		for (fd = 0; fd < NUFILE; fd++)
962 			/* if ep->savefd[fd] < 0, means fd was closed */
963 			if (ep->savefd[fd])
964 				restfd(fd, ep->savefd[fd]);
965 		if (ep->savefd[2])
966 			/* Clear any write errors */
967 			shf_reopen(2, SHF_WR, shl_out);
968 	}
969 	/*
970 	 * Bottom of the stack.
971 	 * Either main shell is exiting or cleanup_parents_env() was called.
972 	 */
973 	if (ep->oenv == NULL) {
974 #ifdef DEBUG_LEAKS
975 		int i;
976 #endif
977 
978 		if (ep->type == E_NONE) {
979 			/* Main shell exiting? */
980 #if HAVE_PERSISTENT_HISTORY
981 			if (Flag(FTALKING))
982 				hist_finish();
983 #endif
984 			j_exit();
985 			if (ep->flags & EF_FAKE_SIGDIE) {
986 				int sig = (exstat & 0xFF) - 128;
987 
988 				/*
989 				 * ham up our death a bit (AT&T ksh
990 				 * only seems to do this for SIGTERM)
991 				 * Don't do it for SIGQUIT, since we'd
992 				 * dump a core..
993 				 */
994 				if ((sig == SIGINT || sig == SIGTERM) &&
995 				    (kshpgrp == kshpid)) {
996 					setsig(&sigtraps[sig], SIG_DFL,
997 					    SS_RESTORE_CURR | SS_FORCE);
998 					kill(0, sig);
999 				}
1000 			}
1001 		}
1002 		if (shf)
1003 			shf_close(shf);
1004 		reclaim();
1005 #ifdef DEBUG_LEAKS
1006 #ifndef MKSH_NO_CMDLINE_EDITING
1007 		x_done();
1008 #endif
1009 		afreeall(APERM);
1010 		for (fd = 3; fd < NUFILE; fd++)
1011 			if ((i = fcntl(fd, F_GETFD, 0)) != -1 &&
1012 			    (i & FD_CLOEXEC))
1013 				close(fd);
1014 		close(2);
1015 		close(1);
1016 		close(0);
1017 #endif
1018 		exit(exstat & 0xFF);
1019 	}
1020 	if (shf)
1021 		shf_close(shf);
1022 	reclaim();
1023 
1024 	e = e->oenv;
1025 
1026 	/* free the struct env - tricky due to the ALLOC_ITEM inside */
1027 	cp = (void *)ep;
1028 	afree(cp + ALLOC_SIZE, ATEMP);
1029 }
1030 
1031 /* Called after a fork to cleanup stuff left over from parents environment */
1032 void
cleanup_parents_env(void)1033 cleanup_parents_env(void)
1034 {
1035 	struct env *ep;
1036 	int fd;
1037 
1038 	mkssert(e != NULL);
1039 
1040 	/*
1041 	 * Don't clean up temporary files - parent will probably need them.
1042 	 * Also, can't easily reclaim memory since variables, etc. could be
1043 	 * anywhere.
1044 	 */
1045 
1046 	/* close all file descriptors hiding in savefd */
1047 	for (ep = e; ep; ep = ep->oenv) {
1048 		if (ep->savefd) {
1049 			for (fd = 0; fd < NUFILE; fd++)
1050 				if (ep->savefd[fd] > 0)
1051 					close(ep->savefd[fd]);
1052 			afree(ep->savefd, &ep->area);
1053 			ep->savefd = NULL;
1054 		}
1055 #ifdef DEBUG_LEAKS
1056 		if (ep->type != E_NONE)
1057 			ep->type = E_GONE;
1058 #endif
1059 	}
1060 #ifndef DEBUG_LEAKS
1061 	e->oenv = NULL;
1062 #endif
1063 }
1064 
1065 /* Called just before an execve cleanup stuff temporary files */
1066 void
cleanup_proc_env(void)1067 cleanup_proc_env(void)
1068 {
1069 	struct env *ep;
1070 
1071 	for (ep = e; ep; ep = ep->oenv)
1072 		remove_temps(ep->temps);
1073 }
1074 
1075 /* remove temp files and free ATEMP Area */
1076 static void
reclaim(void)1077 reclaim(void)
1078 {
1079 	struct block *l;
1080 
1081 	while ((l = e->loc) && (!e->oenv || e->oenv->loc != l)) {
1082 		e->loc = l->next;
1083 		afreeall(&l->area);
1084 	}
1085 
1086 	remove_temps(e->temps);
1087 	e->temps = NULL;
1088 	afreeall(&e->area);
1089 }
1090 
1091 static void
remove_temps(struct temp * tp)1092 remove_temps(struct temp *tp)
1093 {
1094 	for (; tp != NULL; tp = tp->next)
1095 		if (tp->pid == procpid)
1096 			unlink(tp->tffn);
1097 }
1098 
1099 /*
1100  * Initialise tty_fd. Used for tracking the size of the terminal,
1101  * saving/resetting tty modes upon forground job completion, and
1102  * for setting up the tty process group. Return values:
1103  *	0 = got controlling tty
1104  *	1 = got terminal but no controlling tty
1105  *	2 = cannot find a terminal
1106  *	3 = cannot dup fd
1107  *	4 = cannot make fd close-on-exec
1108  * An existing tty_fd is cached if no "better" one could be found,
1109  * i.e. if tty_devtty was already set or the new would not set it.
1110  */
1111 int
tty_init_fd(void)1112 tty_init_fd(void)
1113 {
1114 	int fd, rv, eno = 0;
1115 	bool do_close = false, is_devtty = true;
1116 
1117 	if (tty_devtty) {
1118 		/* already got a tty which is /dev/tty */
1119 		return (0);
1120 	}
1121 
1122 #ifdef _UWIN
1123 	/*XXX imake style */
1124 	if (isatty(3)) {
1125 		/* fd 3 on UWIN _is_ /dev/tty (or our controlling tty) */
1126 		fd = 3;
1127 		goto got_fd;
1128 	}
1129 #endif
1130 	if ((fd = open("/dev/tty", O_RDWR, 0)) >= 0) {
1131 		do_close = true;
1132 		goto got_fd;
1133 	}
1134 	eno = errno;
1135 
1136 	if (tty_fd >= 0) {
1137 		/* already got a non-devtty one */
1138 		rv = 1;
1139 		goto out;
1140 	}
1141 	is_devtty = false;
1142 
1143 	if (isatty((fd = 0)) || isatty((fd = 2)))
1144 		goto got_fd;
1145 	/* cannot find one */
1146 	rv = 2;
1147 	/* assert: do_close == false */
1148 	goto out;
1149 
1150  got_fd:
1151 	if ((rv = fcntl(fd, F_DUPFD, FDBASE)) < 0) {
1152 		eno = errno;
1153 		rv = 3;
1154 		goto out;
1155 	}
1156 	if (fcntl(rv, F_SETFD, FD_CLOEXEC) < 0) {
1157 		eno = errno;
1158 		close(rv);
1159 		rv = 4;
1160 		goto out;
1161 	}
1162 	tty_fd = rv;
1163 	tty_devtty = is_devtty;
1164 	rv = eno = 0;
1165  out:
1166 	if (do_close)
1167 		close(fd);
1168 	errno = eno;
1169 	return (rv);
1170 }
1171 
1172 /* A shell error occurred (eg, syntax error, etc.) */
1173 
1174 #define VWARNINGF_ERRORPREFIX	1
1175 #define VWARNINGF_FILELINE	2
1176 #define VWARNINGF_BUILTIN	4
1177 #define VWARNINGF_INTERNAL	8
1178 
1179 static void vwarningf(unsigned int, const char *, va_list)
1180     MKSH_A_FORMAT(__printf__, 2, 0);
1181 
1182 static void
vwarningf(unsigned int flags,const char * fmt,va_list ap)1183 vwarningf(unsigned int flags, const char *fmt, va_list ap)
1184 {
1185 	if (fmt) {
1186 		if (flags & VWARNINGF_INTERNAL)
1187 			shf_fprintf(shl_out, "internal error: ");
1188 		if (flags & VWARNINGF_ERRORPREFIX)
1189 			error_prefix(tobool(flags & VWARNINGF_FILELINE));
1190 		if ((flags & VWARNINGF_BUILTIN) &&
1191 		    /* not set when main() calls parse_args() */
1192 		    builtin_argv0 && builtin_argv0 != kshname)
1193 			shf_fprintf(shl_out, "%s: ", builtin_argv0);
1194 		shf_vfprintf(shl_out, fmt, ap);
1195 		shf_putchar('\n', shl_out);
1196 	}
1197 	shf_flush(shl_out);
1198 }
1199 
1200 void
errorfx(int rc,const char * fmt,...)1201 errorfx(int rc, const char *fmt, ...)
1202 {
1203 	va_list va;
1204 
1205 	exstat = rc;
1206 
1207 	/* debugging: note that stdout not valid */
1208 	shl_stdout_ok = false;
1209 
1210 	va_start(va, fmt);
1211 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1212 	va_end(va);
1213 	unwind(LERROR);
1214 }
1215 
1216 void
errorf(const char * fmt,...)1217 errorf(const char *fmt, ...)
1218 {
1219 	va_list va;
1220 
1221 	exstat = 1;
1222 
1223 	/* debugging: note that stdout not valid */
1224 	shl_stdout_ok = false;
1225 
1226 	va_start(va, fmt);
1227 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1228 	va_end(va);
1229 	unwind(LERROR);
1230 }
1231 
1232 /* like errorf(), but no unwind is done */
1233 void
warningf(bool fileline,const char * fmt,...)1234 warningf(bool fileline, const char *fmt, ...)
1235 {
1236 	va_list va;
1237 
1238 	va_start(va, fmt);
1239 	vwarningf(VWARNINGF_ERRORPREFIX | (fileline ? VWARNINGF_FILELINE : 0),
1240 	    fmt, va);
1241 	va_end(va);
1242 }
1243 
1244 /*
1245  * Used by built-in utilities to prefix shell and utility name to message
1246  * (also unwinds environments for special builtins).
1247  */
1248 void
bi_errorf(const char * fmt,...)1249 bi_errorf(const char *fmt, ...)
1250 {
1251 	va_list va;
1252 
1253 	/* debugging: note that stdout not valid */
1254 	shl_stdout_ok = false;
1255 
1256 	exstat = 1;
1257 
1258 	va_start(va, fmt);
1259 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE |
1260 	    VWARNINGF_BUILTIN, fmt, va);
1261 	va_end(va);
1262 
1263 	/*
1264 	 * POSIX special builtins and ksh special builtins cause
1265 	 * non-interactive shells to exit.
1266 	 * XXX odd use of KEEPASN; also may not want LERROR here
1267 	 */
1268 	if (builtin_flag & SPEC_BI) {
1269 		builtin_argv0 = NULL;
1270 		unwind(LERROR);
1271 	}
1272 }
1273 
1274 /* Called when something that shouldn't happen does */
1275 void
internal_errorf(const char * fmt,...)1276 internal_errorf(const char *fmt, ...)
1277 {
1278 	va_list va;
1279 
1280 	va_start(va, fmt);
1281 	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1282 	va_end(va);
1283 	unwind(LERROR);
1284 }
1285 
1286 void
internal_warningf(const char * fmt,...)1287 internal_warningf(const char *fmt, ...)
1288 {
1289 	va_list va;
1290 
1291 	va_start(va, fmt);
1292 	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1293 	va_end(va);
1294 }
1295 
1296 /* used by error reporting functions to print "ksh: .kshrc[25]: " */
1297 void
error_prefix(bool fileline)1298 error_prefix(bool fileline)
1299 {
1300 	/* Avoid foo: foo[2]: ... */
1301 	if (!fileline || !source || !source->file ||
1302 	    strcmp(source->file, kshname) != 0)
1303 		shf_fprintf(shl_out, "%s: ", kshname + (*kshname == '-'));
1304 	if (fileline && source && source->file != NULL) {
1305 		shf_fprintf(shl_out, "%s[%d]: ", source->file,
1306 		    source->errline > 0 ? source->errline : source->line);
1307 		source->errline = 0;
1308 	}
1309 }
1310 
1311 /* printf to shl_out (stderr) with flush */
1312 void
shellf(const char * fmt,...)1313 shellf(const char *fmt, ...)
1314 {
1315 	va_list va;
1316 
1317 	if (!initio_done)
1318 		/* shl_out may not be set up yet... */
1319 		return;
1320 	va_start(va, fmt);
1321 	shf_vfprintf(shl_out, fmt, va);
1322 	va_end(va);
1323 	shf_flush(shl_out);
1324 }
1325 
1326 /* printf to shl_stdout (stdout) */
1327 void
shprintf(const char * fmt,...)1328 shprintf(const char *fmt, ...)
1329 {
1330 	va_list va;
1331 
1332 	if (!shl_stdout_ok)
1333 		internal_errorf("shl_stdout not valid");
1334 	va_start(va, fmt);
1335 	shf_vfprintf(shl_stdout, fmt, va);
1336 	va_end(va);
1337 }
1338 
1339 /* test if we can seek backwards fd (returns 0 or SHF_UNBUF) */
1340 int
can_seek(int fd)1341 can_seek(int fd)
1342 {
1343 	struct stat statb;
1344 
1345 	return (fstat(fd, &statb) == 0 && !S_ISREG(statb.st_mode) ?
1346 	    SHF_UNBUF : 0);
1347 }
1348 
1349 #ifdef DF
1350 int shl_dbg_fd;
1351 #define NSHF_IOB 4
1352 #else
1353 #define NSHF_IOB 3
1354 #endif
1355 struct shf shf_iob[NSHF_IOB];
1356 
1357 void
initio(void)1358 initio(void)
1359 {
1360 #ifdef DF
1361 	const char *lfp;
1362 #endif
1363 
1364 	/* force buffer allocation */
1365 	shf_fdopen(1, SHF_WR, shl_stdout);
1366 	shf_fdopen(2, SHF_WR, shl_out);
1367 	shf_fdopen(2, SHF_WR, shl_spare);
1368 #ifdef DF
1369 	if ((lfp = getenv("SDMKSH_PATH")) == NULL) {
1370 		if ((lfp = getenv("HOME")) == NULL || *lfp != '/')
1371 			errorf("cannot get home directory");
1372 		lfp = shf_smprintf("%s/mksh-dbg.txt", lfp);
1373 	}
1374 
1375 	if ((shl_dbg_fd = open(lfp, O_WRONLY | O_APPEND | O_CREAT, 0600)) < 0)
1376 		errorf("cannot open debug output file %s", lfp);
1377 	if (shl_dbg_fd < FDBASE) {
1378 		int nfd;
1379 
1380 		nfd = fcntl(shl_dbg_fd, F_DUPFD, FDBASE);
1381 		close(shl_dbg_fd);
1382 		if ((shl_dbg_fd = nfd) == -1)
1383 			errorf("cannot dup debug output file");
1384 	}
1385 	fcntl(shl_dbg_fd, F_SETFD, FD_CLOEXEC);
1386 	shf_fdopen(shl_dbg_fd, SHF_WR, shl_dbg);
1387 	DF("=== open ===");
1388 #endif
1389 	initio_done = true;
1390 }
1391 
1392 /* A dup2() with error checking */
1393 int
ksh_dup2(int ofd,int nfd,bool errok)1394 ksh_dup2(int ofd, int nfd, bool errok)
1395 {
1396 	int rv;
1397 
1398 	if (((rv = dup2(ofd, nfd)) < 0) && !errok && (errno != EBADF))
1399 		errorf("too many files open in shell");
1400 
1401 #ifdef __ultrix
1402 	/*XXX imake style */
1403 	if (rv >= 0)
1404 		fcntl(nfd, F_SETFD, 0);
1405 #endif
1406 
1407 	return (rv);
1408 }
1409 
1410 /*
1411  * Move fd from user space (0 <= fd < 10) to shell space (fd >= 10),
1412  * set close-on-exec flag. See FDBASE in sh.h, maybe 24 not 10 here.
1413  */
1414 short
savefd(int fd)1415 savefd(int fd)
1416 {
1417 	int nfd = fd;
1418 
1419 	if (fd < FDBASE && (nfd = fcntl(fd, F_DUPFD, FDBASE)) < 0 &&
1420 	    errno == EBADF)
1421 		return (-1);
1422 	if (nfd < 0 || nfd > SHRT_MAX)
1423 		errorf("too many files open in shell");
1424 	fcntl(nfd, F_SETFD, FD_CLOEXEC);
1425 	return ((short)nfd);
1426 }
1427 
1428 void
restfd(int fd,int ofd)1429 restfd(int fd, int ofd)
1430 {
1431 	if (fd == 2)
1432 		shf_flush(&shf_iob[/* fd */ 2]);
1433 	if (ofd < 0)
1434 		/* original fd closed */
1435 		close(fd);
1436 	else if (fd != ofd) {
1437 		/*XXX: what to do if this dup fails? */
1438 		ksh_dup2(ofd, fd, true);
1439 		close(ofd);
1440 	}
1441 }
1442 
1443 void
openpipe(int * pv)1444 openpipe(int *pv)
1445 {
1446 	int lpv[2];
1447 
1448 	if (pipe(lpv) < 0)
1449 		errorf("can't create pipe - try again");
1450 	pv[0] = savefd(lpv[0]);
1451 	if (pv[0] != lpv[0])
1452 		close(lpv[0]);
1453 	pv[1] = savefd(lpv[1]);
1454 	if (pv[1] != lpv[1])
1455 		close(lpv[1]);
1456 }
1457 
1458 void
closepipe(int * pv)1459 closepipe(int *pv)
1460 {
1461 	close(pv[0]);
1462 	close(pv[1]);
1463 }
1464 
1465 /*
1466  * Called by iosetup() (deals with 2>&4, etc.), c_read, c_print to turn
1467  * a string (the X in 2>&X, read -uX, print -uX) into a file descriptor.
1468  */
1469 int
check_fd(const char * name,int mode,const char ** emsgp)1470 check_fd(const char *name, int mode, const char **emsgp)
1471 {
1472 	int fd, fl;
1473 
1474 	if (name[0] == 'p' && !name[1])
1475 		return (coproc_getfd(mode, emsgp));
1476 	for (fd = 0; ksh_isdigit(*name); ++name)
1477 		fd = (fd * 10) + *name - '0';
1478 	if (*name || fd >= FDBASE) {
1479 		if (emsgp)
1480 			*emsgp = "illegal file descriptor name";
1481 		return (-1);
1482 	}
1483 	if ((fl = fcntl(fd, F_GETFL, 0)) < 0) {
1484 		if (emsgp)
1485 			*emsgp = "bad file descriptor";
1486 		return (-1);
1487 	}
1488 	fl &= O_ACCMODE;
1489 	/*
1490 	 * X_OK is a kludge to disable this check for dups (x<&1):
1491 	 * historical shells never did this check (XXX don't know what
1492 	 * POSIX has to say).
1493 	 */
1494 	if (!(mode & X_OK) && fl != O_RDWR && (
1495 	    ((mode & R_OK) && fl != O_RDONLY) ||
1496 	    ((mode & W_OK) && fl != O_WRONLY))) {
1497 		if (emsgp)
1498 			*emsgp = (fl == O_WRONLY) ?
1499 			    "fd not open for reading" :
1500 			    "fd not open for writing";
1501 		return (-1);
1502 	}
1503 	return (fd);
1504 }
1505 
1506 /* Called once from main */
1507 void
coproc_init(void)1508 coproc_init(void)
1509 {
1510 	coproc.read = coproc.readw = coproc.write = -1;
1511 	coproc.njobs = 0;
1512 	coproc.id = 0;
1513 }
1514 
1515 /* Called by c_read() when eof is read - close fd if it is the co-process fd */
1516 void
coproc_read_close(int fd)1517 coproc_read_close(int fd)
1518 {
1519 	if (coproc.read >= 0 && fd == coproc.read) {
1520 		coproc_readw_close(fd);
1521 		close(coproc.read);
1522 		coproc.read = -1;
1523 	}
1524 }
1525 
1526 /*
1527  * Called by c_read() and by iosetup() to close the other side of the
1528  * read pipe, so reads will actually terminate.
1529  */
1530 void
coproc_readw_close(int fd)1531 coproc_readw_close(int fd)
1532 {
1533 	if (coproc.readw >= 0 && coproc.read >= 0 && fd == coproc.read) {
1534 		close(coproc.readw);
1535 		coproc.readw = -1;
1536 	}
1537 }
1538 
1539 /*
1540  * Called by c_print when a write to a fd fails with EPIPE and by iosetup
1541  * when co-process input is dup'd
1542  */
1543 void
coproc_write_close(int fd)1544 coproc_write_close(int fd)
1545 {
1546 	if (coproc.write >= 0 && fd == coproc.write) {
1547 		close(coproc.write);
1548 		coproc.write = -1;
1549 	}
1550 }
1551 
1552 /*
1553  * Called to check for existence of/value of the co-process file descriptor.
1554  * (Used by check_fd() and by c_read/c_print to deal with -p option).
1555  */
1556 int
coproc_getfd(int mode,const char ** emsgp)1557 coproc_getfd(int mode, const char **emsgp)
1558 {
1559 	int fd = (mode & R_OK) ? coproc.read : coproc.write;
1560 
1561 	if (fd >= 0)
1562 		return (fd);
1563 	if (emsgp)
1564 		*emsgp = "no coprocess";
1565 	return (-1);
1566 }
1567 
1568 /*
1569  * called to close file descriptors related to the coprocess (if any)
1570  * Should be called with SIGCHLD blocked.
1571  */
1572 void
coproc_cleanup(int reuse)1573 coproc_cleanup(int reuse)
1574 {
1575 	/* This to allow co-processes to share output pipe */
1576 	if (!reuse || coproc.readw < 0 || coproc.read < 0) {
1577 		if (coproc.read >= 0) {
1578 			close(coproc.read);
1579 			coproc.read = -1;
1580 		}
1581 		if (coproc.readw >= 0) {
1582 			close(coproc.readw);
1583 			coproc.readw = -1;
1584 		}
1585 	}
1586 	if (coproc.write >= 0) {
1587 		close(coproc.write);
1588 		coproc.write = -1;
1589 	}
1590 }
1591 
1592 struct temp *
maketemp(Area * ap,Temp_type type,struct temp ** tlist)1593 maketemp(Area *ap, Temp_type type, struct temp **tlist)
1594 {
1595 	char *cp;
1596 	size_t len;
1597 	int i;
1598 	struct temp *tp;
1599 	const char *dir;
1600 	struct stat sb;
1601 
1602 	dir = tmpdir ? tmpdir : MKSH_DEFAULT_TMPDIR;
1603 	/* add "/shXXXXXX.tmp" plus NUL */
1604 	len = strlen(dir);
1605 	checkoktoadd(len, offsetof(struct temp, tffn[0]) + 14);
1606 	tp = alloc(offsetof(struct temp, tffn[0]) + 14 + len, ap);
1607 
1608 	tp->shf = NULL;
1609 	tp->pid = procpid;
1610 	tp->type = type;
1611 
1612 	if (stat(dir, &sb) || !S_ISDIR(sb.st_mode)) {
1613 		tp->tffn[0] = '\0';
1614 		goto maketemp_out;
1615 	}
1616 
1617 	cp = (void *)tp;
1618 	cp += offsetof(struct temp, tffn[0]);
1619 	memcpy(cp, dir, len);
1620 	cp += len;
1621 	memcpy(cp, "/shXXXXXX.tmp", 14);
1622 	/* point to the first of six Xes */
1623 	cp += 3;
1624 	/* generate random part of filename */
1625 	len = -1;
1626 	do {
1627 		i = rndget() % 36;
1628 		cp[++len] = i < 26 ? 'a' + i : '0' + i - 26;
1629 	} while (len < 5);
1630 
1631 	/* cyclically attempt to open a temporary file */
1632 	while ((i = open(tp->tffn, O_CREAT | O_EXCL | O_RDWR, 0600)) < 0) {
1633 		if (errno != EEXIST)
1634 			goto maketemp_out;
1635 		/* count down from z to a then from 9 to 0 */
1636 		while (cp[len] == '0')
1637 			if (!len--)
1638 				goto maketemp_out;
1639 		if (cp[len] == 'a')
1640 			cp[len] = '9';
1641 		else
1642 			--cp[len];
1643 		/* do another cycle */
1644 	}
1645 
1646 	if (type == TT_FUNSUB) {
1647 		int nfd;
1648 
1649 		/* map us high and mark as close-on-exec */
1650 		if ((nfd = savefd(i)) != i) {
1651 			close(i);
1652 			i = nfd;
1653 		}
1654 	}
1655 
1656 	/* shf_fdopen cannot fail, so no fd leak */
1657 	tp->shf = shf_fdopen(i, SHF_WR, NULL);
1658 
1659  maketemp_out:
1660 	tp->next = *tlist;
1661 	*tlist = tp;
1662 	return (tp);
1663 }
1664 
1665 /*
1666  * We use a similar collision resolution algorithm as Python 2.5.4
1667  * but with a slightly tweaked implementation written from scratch.
1668  */
1669 
1670 #define	INIT_TBLSHIFT	3	/* initial table shift (2^3 = 8) */
1671 #define PERTURB_SHIFT	5	/* see Python 2.5.4 Objects/dictobject.c */
1672 
1673 static void tgrow(struct table *);
1674 static int tnamecmp(const void *, const void *);
1675 
1676 static void
tgrow(struct table * tp)1677 tgrow(struct table *tp)
1678 {
1679 	size_t i, j, osize, mask, perturb;
1680 	struct tbl *tblp, **pp;
1681 	struct tbl **ntblp, **otblp = tp->tbls;
1682 
1683 	if (tp->tshift > 29)
1684 		internal_errorf("hash table size limit reached");
1685 
1686 	/* calculate old size, new shift and new size */
1687 	osize = (size_t)1 << (tp->tshift++);
1688 	i = osize << 1;
1689 
1690 	ntblp = alloc2(i, sizeof(struct tbl *), tp->areap);
1691 	/* multiplication cannot overflow: alloc2 checked that */
1692 	memset(ntblp, 0, i * sizeof(struct tbl *));
1693 
1694 	/* table can get very full when reaching its size limit */
1695 	tp->nfree = (tp->tshift == 30) ? 0x3FFF0000UL :
1696 	    /* but otherwise, only 75% */
1697 	    ((i * 3) / 4);
1698 	tp->tbls = ntblp;
1699 	if (otblp == NULL)
1700 		return;
1701 
1702 	mask = i - 1;
1703 	for (i = 0; i < osize; i++)
1704 		if ((tblp = otblp[i]) != NULL) {
1705 			if ((tblp->flag & DEFINED)) {
1706 				/* search for free hash table slot */
1707 				j = perturb = tblp->ua.hval;
1708 				goto find_first_empty_slot;
1709  find_next_empty_slot:
1710 				j = (j << 2) + j + perturb + 1;
1711 				perturb >>= PERTURB_SHIFT;
1712  find_first_empty_slot:
1713 				pp = &ntblp[j & mask];
1714 				if (*pp != NULL)
1715 					goto find_next_empty_slot;
1716 				/* found an empty hash table slot */
1717 				*pp = tblp;
1718 				tp->nfree--;
1719 			} else if (!(tblp->flag & FINUSE)) {
1720 				afree(tblp, tp->areap);
1721 			}
1722 		}
1723 	afree(otblp, tp->areap);
1724 }
1725 
1726 void
ktinit(Area * ap,struct table * tp,uint8_t initshift)1727 ktinit(Area *ap, struct table *tp, uint8_t initshift)
1728 {
1729 	tp->areap = ap;
1730 	tp->tbls = NULL;
1731 	tp->tshift = ((initshift > INIT_TBLSHIFT) ?
1732 	    initshift : INIT_TBLSHIFT) - 1;
1733 	tgrow(tp);
1734 }
1735 
1736 /* table, name (key) to search for, hash(name), rv pointer to tbl ptr */
1737 struct tbl *
ktscan(struct table * tp,const char * name,uint32_t h,struct tbl *** ppp)1738 ktscan(struct table *tp, const char *name, uint32_t h, struct tbl ***ppp)
1739 {
1740 	size_t j, perturb, mask;
1741 	struct tbl **pp, *p;
1742 
1743 	mask = ((size_t)1 << (tp->tshift)) - 1;
1744 	/* search for hash table slot matching name */
1745 	j = perturb = h;
1746 	goto find_first_slot;
1747  find_next_slot:
1748 	j = (j << 2) + j + perturb + 1;
1749 	perturb >>= PERTURB_SHIFT;
1750  find_first_slot:
1751 	pp = &tp->tbls[j & mask];
1752 	if ((p = *pp) != NULL && (p->ua.hval != h || !(p->flag & DEFINED) ||
1753 	    strcmp(p->name, name)))
1754 		goto find_next_slot;
1755 	/* p == NULL if not found, correct found entry otherwise */
1756 	if (ppp)
1757 		*ppp = pp;
1758 	return (p);
1759 }
1760 
1761 /* table, name (key) to enter, hash(n) */
1762 struct tbl *
ktenter(struct table * tp,const char * n,uint32_t h)1763 ktenter(struct table *tp, const char *n, uint32_t h)
1764 {
1765 	struct tbl **pp, *p;
1766 	size_t len;
1767 
1768  Search:
1769 	if ((p = ktscan(tp, n, h, &pp)))
1770 		return (p);
1771 
1772 	if (tp->nfree == 0) {
1773 		/* too full */
1774 		tgrow(tp);
1775 		goto Search;
1776 	}
1777 
1778 	/* create new tbl entry */
1779 	len = strlen(n);
1780 	checkoktoadd(len, offsetof(struct tbl, name[0]) + 1);
1781 	p = alloc(offsetof(struct tbl, name[0]) + ++len, tp->areap);
1782 	p->flag = 0;
1783 	p->type = 0;
1784 	p->areap = tp->areap;
1785 	p->ua.hval = h;
1786 	p->u2.field = 0;
1787 	p->u.array = NULL;
1788 	memcpy(p->name, n, len);
1789 
1790 	/* enter in tp->tbls */
1791 	tp->nfree--;
1792 	*pp = p;
1793 	return (p);
1794 }
1795 
1796 void
ktwalk(struct tstate * ts,struct table * tp)1797 ktwalk(struct tstate *ts, struct table *tp)
1798 {
1799 	ts->left = (size_t)1 << (tp->tshift);
1800 	ts->next = tp->tbls;
1801 }
1802 
1803 struct tbl *
ktnext(struct tstate * ts)1804 ktnext(struct tstate *ts)
1805 {
1806 	while (--ts->left >= 0) {
1807 		struct tbl *p = *ts->next++;
1808 		if (p != NULL && (p->flag & DEFINED))
1809 			return (p);
1810 	}
1811 	return (NULL);
1812 }
1813 
1814 static int
tnamecmp(const void * p1,const void * p2)1815 tnamecmp(const void *p1, const void *p2)
1816 {
1817 	const struct tbl *a = *((const struct tbl * const *)p1);
1818 	const struct tbl *b = *((const struct tbl * const *)p2);
1819 
1820 	return (strcmp(a->name, b->name));
1821 }
1822 
1823 struct tbl **
ktsort(struct table * tp)1824 ktsort(struct table *tp)
1825 {
1826 	size_t i;
1827 	struct tbl **p, **sp, **dp;
1828 
1829 	/*
1830 	 * since the table is never entirely full, no need to reserve
1831 	 * additional space for the trailing NULL appended below
1832 	 */
1833 	i = (size_t)1 << (tp->tshift);
1834 	p = alloc2(i, sizeof(struct tbl *), ATEMP);
1835 	sp = tp->tbls;		/* source */
1836 	dp = p;			/* dest */
1837 	while (i--)
1838 		if ((*dp = *sp++) != NULL && (((*dp)->flag & DEFINED) ||
1839 		    ((*dp)->flag & ARRAY)))
1840 			dp++;
1841 	qsort(p, (i = dp - p), sizeof(struct tbl *), tnamecmp);
1842 	p[i] = NULL;
1843 	return (p);
1844 }
1845 
1846 #ifdef SIGWINCH
1847 static void
x_sigwinch(int sig MKSH_A_UNUSED)1848 x_sigwinch(int sig MKSH_A_UNUSED)
1849 {
1850 	/* this runs inside interrupt context, with errno saved */
1851 
1852 	got_winch = 1;
1853 }
1854 #endif
1855 
1856 #ifdef DF
1857 void
DF(const char * fmt,...)1858 DF(const char *fmt, ...)
1859 {
1860 	va_list args;
1861 	struct timeval tv;
1862 	mirtime_mjd mjd;
1863 
1864 	mksh_lockfd(shl_dbg_fd);
1865 	mksh_TIME(tv);
1866 	timet2mjd(&mjd, tv.tv_sec);
1867 	shf_fprintf(shl_dbg, "[%02u:%02u:%02u (%u) %u.%06u] ",
1868 	    (unsigned)mjd.sec / 3600, ((unsigned)mjd.sec / 60) % 60,
1869 	    (unsigned)mjd.sec % 60, (unsigned)getpid(),
1870 	    (unsigned)tv.tv_sec, (unsigned)tv.tv_usec);
1871 	va_start(args, fmt);
1872 	shf_vfprintf(shl_dbg, fmt, args);
1873 	va_end(args);
1874 	shf_putc('\n', shl_dbg);
1875 	shf_flush(shl_dbg);
1876 	mksh_unlkfd(shl_dbg_fd);
1877 }
1878 #endif
1879 
1880 void
x_mkraw(int fd,mksh_ttyst * ocb,bool forread)1881 x_mkraw(int fd, mksh_ttyst *ocb, bool forread)
1882 {
1883 	mksh_ttyst cb;
1884 
1885 	if (ocb)
1886 		mksh_tcget(fd, ocb);
1887 	else
1888 		ocb = &tty_state;
1889 
1890 	cb = *ocb;
1891 	if (forread) {
1892 		cb.c_lflag &= ~(ICANON) | ECHO;
1893 	} else {
1894 		cb.c_iflag &= ~(INLCR | ICRNL);
1895 		cb.c_lflag &= ~(ISIG | ICANON | ECHO);
1896 	}
1897 #if defined(VLNEXT) && defined(_POSIX_VDISABLE)
1898 	/* OSF/1 processes lnext when ~icanon */
1899 	cb.c_cc[VLNEXT] = _POSIX_VDISABLE;
1900 #endif
1901 	/* SunOS 4.1.x & OSF/1 processes discard(flush) when ~icanon */
1902 #if defined(VDISCARD) && defined(_POSIX_VDISABLE)
1903 	cb.c_cc[VDISCARD] = _POSIX_VDISABLE;
1904 #endif
1905 	cb.c_cc[VTIME] = 0;
1906 	cb.c_cc[VMIN] = 1;
1907 
1908 	mksh_tcset(fd, &cb);
1909 }
1910