1 /*	$OpenBSD: var.c,v 1.38 2013/12/20 17:53:09 zhuk Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
5  *		 2011, 2012, 2013, 2014, 2015
6  *	Thorsten Glaser <tg@mirbsd.org>
7  *
8  * Provided that these terms and disclaimer and all copyright notices
9  * are retained or reproduced in an accompanying document, permission
10  * is granted to deal in this work without restriction, including un-
11  * limited rights to use, publicly perform, distribute, sell, modify,
12  * merge, give away, or sublicence.
13  *
14  * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
15  * the utmost extent permitted by applicable law, neither express nor
16  * implied; without malicious intent or gross negligence. In no event
17  * may a licensor, author or contributor be held liable for indirect,
18  * direct, other damage, loss, or other issues arising in any way out
19  * of dealing in the work, even if advised of the possibility of such
20  * damage or existence of a defect, except proven that it results out
21  * of said person's immediate fault when using the work as intended.
22  */
23 
24 #include "sh.h"
25 #include "mirhash.h"
26 
27 #if defined(__OpenBSD__)
28 #include <sys/sysctl.h>
29 #endif
30 
31 __RCSID("$MirOS: src/bin/mksh/var.c,v 1.183.2.4 2015/04/19 19:18:23 tg Exp $");
32 
33 /*-
34  * Variables
35  *
36  * WARNING: unreadable code, needs a rewrite
37  *
38  * if (flag&INTEGER), val.i contains integer value, and type contains base.
39  * otherwise, (val.s + type) contains string value.
40  * if (flag&EXPORT), val.s contains "name=value" for E-Z exporting.
41  */
42 
43 static struct table specials;
44 static uint32_t lcg_state = 5381, qh_state = 4711;
45 /* may only be set by typeset() just before call to array_index_calc() */
46 static enum namerefflag innermost_refflag = SRF_NOP;
47 
48 static char *formatstr(struct tbl *, const char *);
49 static void exportprep(struct tbl *, const char *);
50 static int special(const char *);
51 static void unspecial(const char *);
52 static void getspec(struct tbl *);
53 static void setspec(struct tbl *);
54 static void unsetspec(struct tbl *);
55 static int getint(struct tbl *, mksh_ari_u *, bool);
56 static const char *array_index_calc(const char *, bool *, uint32_t *);
57 
58 /*
59  * create a new block for function calls and simple commands
60  * assume caller has allocated and set up e->loc
61  */
62 void
newblock(void)63 newblock(void)
64 {
65 	struct block *l;
66 	static const char *empty[] = { null };
67 
68 	l = alloc(sizeof(struct block), ATEMP);
69 	l->flags = 0;
70 	/* TODO: could use e->area (l->area => l->areap) */
71 	ainit(&l->area);
72 	if (!e->loc) {
73 		l->argc = 0;
74 		l->argv = empty;
75 	} else {
76 		l->argc = e->loc->argc;
77 		l->argv = e->loc->argv;
78 	}
79 	l->exit = l->error = NULL;
80 	ktinit(&l->area, &l->vars, 0);
81 	ktinit(&l->area, &l->funs, 0);
82 	l->next = e->loc;
83 	e->loc = l;
84 }
85 
86 /*
87  * pop a block handling special variables
88  */
89 void
popblock(void)90 popblock(void)
91 {
92 	ssize_t i;
93 	struct block *l = e->loc;
94 	struct tbl *vp, **vpp = l->vars.tbls, *vq;
95 
96 	/* pop block */
97 	e->loc = l->next;
98 
99 	i = 1 << (l->vars.tshift);
100 	while (--i >= 0)
101 		if ((vp = *vpp++) != NULL && (vp->flag&SPECIAL)) {
102 			if ((vq = global(vp->name))->flag & ISSET)
103 				setspec(vq);
104 			else
105 				unsetspec(vq);
106 		}
107 	if (l->flags & BF_DOGETOPTS)
108 		user_opt = l->getopts_state;
109 	afreeall(&l->area);
110 	afree(l, ATEMP);
111 }
112 
113 /* called by main() to initialise variable data structures */
114 #define VARSPEC_DEFNS
115 #include "var_spec.h"
116 
117 enum var_specs {
118 #define VARSPEC_ENUMS
119 #include "var_spec.h"
120 	V_MAX
121 };
122 
123 /* this is biased with -1 relative to VARSPEC_ENUMS */
124 static const char * const initvar_names[] = {
125 #define VARSPEC_ITEMS
126 #include "var_spec.h"
127 };
128 
129 void
initvar(void)130 initvar(void)
131 {
132 	int i = 0;
133 	struct tbl *tp;
134 
135 	ktinit(APERM, &specials,
136 	    /* currently 14 specials: 75% of 32 = 2^5 */
137 	    5);
138 	while (i < V_MAX - 1) {
139 		tp = ktenter(&specials, initvar_names[i],
140 		    hash(initvar_names[i]));
141 		tp->flag = DEFINED|ISSET;
142 		tp->type = ++i;
143 	}
144 }
145 
146 /* common code for several functions below and c_typeset() */
147 struct block *
varsearch(struct block * l,struct tbl ** vpp,const char * vn,uint32_t h)148 varsearch(struct block *l, struct tbl **vpp, const char *vn, uint32_t h)
149 {
150 	register struct tbl *vp;
151 
152 	if (l) {
153  varsearch_loop:
154 		if ((vp = ktsearch(&l->vars, vn, h)) != NULL)
155 			goto varsearch_out;
156 		if (l->next != NULL) {
157 			l = l->next;
158 			goto varsearch_loop;
159 		}
160 	}
161 	vp = NULL;
162  varsearch_out:
163 	*vpp = vp;
164 	return (l);
165 }
166 
167 /*
168  * Used to calculate an array index for global()/local(). Sets *arrayp
169  * to true if this is an array, sets *valp to the array index, returns
170  * the basename of the array. May only be called from global()/local()
171  * and must be their first callee.
172  */
173 static const char *
array_index_calc(const char * n,bool * arrayp,uint32_t * valp)174 array_index_calc(const char *n, bool *arrayp, uint32_t *valp)
175 {
176 	const char *p;
177 	size_t len;
178 	char *ap = NULL;
179 
180 	*arrayp = false;
181  redo_from_ref:
182 	p = skip_varname(n, false);
183 	if (innermost_refflag == SRF_NOP && (p != n) && ksh_isalphx(n[0])) {
184 		struct tbl *vp;
185 		char *vn;
186 
187 		strndupx(vn, n, p - n, ATEMP);
188 		/* check if this is a reference */
189 		varsearch(e->loc, &vp, vn, hash(vn));
190 		afree(vn, ATEMP);
191 		if (vp && (vp->flag & (DEFINED | ASSOC | ARRAY)) ==
192 		    (DEFINED | ASSOC)) {
193 			char *cp;
194 
195 			/* gotcha! */
196 			cp = shf_smprintf("%s%s", str_val(vp), p);
197 			afree(ap, ATEMP);
198 			n = ap = cp;
199 			goto redo_from_ref;
200 		}
201 	}
202 	innermost_refflag = SRF_NOP;
203 
204 	if (p != n && *p == '[' && (len = array_ref_len(p))) {
205 		char *sub, *tmp;
206 		mksh_ari_t rval;
207 
208 		/* calculate the value of the subscript */
209 		*arrayp = true;
210 		strndupx(tmp, p + 1, len - 2, ATEMP);
211 		sub = substitute(tmp, 0);
212 		afree(tmp, ATEMP);
213 		strndupx(n, n, p - n, ATEMP);
214 		evaluate(sub, &rval, KSH_UNWIND_ERROR, true);
215 		*valp = (uint32_t)rval;
216 		afree(sub, ATEMP);
217 	}
218 	return (n);
219 }
220 
221 /*
222  * Search for variable, if not found create globally.
223  */
224 struct tbl *
global(const char * n)225 global(const char *n)
226 {
227 	struct block *l = e->loc;
228 	struct tbl *vp;
229 	int c;
230 	bool array;
231 	uint32_t h, val;
232 
233 	/*
234 	 * check to see if this is an array;
235 	 * dereference namerefs; must come first
236 	 */
237 	n = array_index_calc(n, &array, &val);
238 	h = hash(n);
239 	c = (unsigned char)n[0];
240 	if (!ksh_isalphx(c)) {
241 		if (array)
242 			errorf("bad substitution");
243 		vp = &vtemp;
244 		vp->flag = DEFINED;
245 		vp->type = 0;
246 		vp->areap = ATEMP;
247 		*vp->name = c;
248 		if (ksh_isdigit(c)) {
249 			if (getn(n, &c) && (c <= l->argc))
250 				/* setstr can't fail here */
251 				setstr(vp, l->argv[c], KSH_RETURN_ERROR);
252 			vp->flag |= RDONLY;
253 			return (vp);
254 		}
255 		vp->flag |= RDONLY;
256 		if (n[1] != '\0')
257 			return (vp);
258 		vp->flag |= ISSET|INTEGER;
259 		switch (c) {
260 		case '$':
261 			vp->val.i = kshpid;
262 			break;
263 		case '!':
264 			/* if no job, expand to nothing */
265 			if ((vp->val.i = j_async()) == 0)
266 				vp->flag &= ~(ISSET|INTEGER);
267 			break;
268 		case '?':
269 			vp->val.i = exstat & 0xFF;
270 			break;
271 		case '#':
272 			vp->val.i = l->argc;
273 			break;
274 		case '-':
275 			vp->flag &= ~INTEGER;
276 			vp->val.s = getoptions();
277 			break;
278 		default:
279 			vp->flag &= ~(ISSET|INTEGER);
280 		}
281 		return (vp);
282 	}
283 	l = varsearch(e->loc, &vp, n, h);
284 	if (vp != NULL)
285 		return (array ? arraysearch(vp, val) : vp);
286 	vp = ktenter(&l->vars, n, h);
287 	if (array)
288 		vp = arraysearch(vp, val);
289 	vp->flag |= DEFINED;
290 	if (special(n))
291 		vp->flag |= SPECIAL;
292 	return (vp);
293 }
294 
295 /*
296  * Search for local variable, if not found create locally.
297  */
298 struct tbl *
local(const char * n,bool copy)299 local(const char *n, bool copy)
300 {
301 	struct block *l = e->loc;
302 	struct tbl *vp;
303 	bool array;
304 	uint32_t h, val;
305 
306 	/*
307 	 * check to see if this is an array;
308 	 * dereference namerefs; must come first
309 	 */
310 	n = array_index_calc(n, &array, &val);
311 	h = hash(n);
312 	if (!ksh_isalphx(*n)) {
313 		vp = &vtemp;
314 		vp->flag = DEFINED|RDONLY;
315 		vp->type = 0;
316 		vp->areap = ATEMP;
317 		return (vp);
318 	}
319 	vp = ktenter(&l->vars, n, h);
320 	if (copy && !(vp->flag & DEFINED)) {
321 		struct tbl *vq;
322 
323 		varsearch(l->next, &vq, n, h);
324 		if (vq != NULL) {
325 			vp->flag |= vq->flag &
326 			    (EXPORT | INTEGER | RDONLY | LJUST | RJUST |
327 			    ZEROFIL | LCASEV | UCASEV_AL | INT_U | INT_L);
328 			if (vq->flag & INTEGER)
329 				vp->type = vq->type;
330 			vp->u2.field = vq->u2.field;
331 		}
332 	}
333 	if (array)
334 		vp = arraysearch(vp, val);
335 	vp->flag |= DEFINED;
336 	if (special(n))
337 		vp->flag |= SPECIAL;
338 	return (vp);
339 }
340 
341 /* get variable string value */
342 char *
str_val(struct tbl * vp)343 str_val(struct tbl *vp)
344 {
345 	char *s;
346 
347 	if ((vp->flag&SPECIAL))
348 		getspec(vp);
349 	if (!(vp->flag&ISSET))
350 		/* special to dollar() */
351 		s = null;
352 	else if (!(vp->flag&INTEGER))
353 		/* string source */
354 		s = vp->val.s + vp->type;
355 	else {
356 		/* integer source */
357 		mksh_uari_t n;
358 		unsigned int base;
359 		/**
360 		 * worst case number length is when base == 2:
361 		 *	1 (minus) + 2 (base, up to 36) + 1 ('#') +
362 		 *	number of bits in the mksh_uari_t + 1 (NUL)
363 		 */
364 		char strbuf[1 + 2 + 1 + 8 * sizeof(mksh_uari_t) + 1];
365 		const char *digits = (vp->flag & UCASEV_AL) ?
366 		    digits_uc : digits_lc;
367 
368 		s = strbuf + sizeof(strbuf);
369 		if (vp->flag & INT_U)
370 			n = vp->val.u;
371 		else
372 			n = (vp->val.i < 0) ? -vp->val.u : vp->val.u;
373 		base = (vp->type == 0) ? 10U : (unsigned int)vp->type;
374 
375 		if (base == 1 && n == 0)
376 			base = 2;
377 		if (base == 1) {
378 			size_t sz = 1;
379 
380 			*(s = strbuf) = '1';
381 			s[1] = '#';
382 			if (!UTFMODE || ((n & 0xFF80) == 0xEF80))
383 				/* OPTU-16 -> raw octet */
384 				s[2] = n & 0xFF;
385 			else
386 				sz = utf_wctomb(s + 2, n);
387 			s[2 + sz] = '\0';
388 		} else {
389 			*--s = '\0';
390 			do {
391 				*--s = digits[n % base];
392 				n /= base;
393 			} while (n != 0);
394 			if (base != 10) {
395 				*--s = '#';
396 				*--s = digits[base % 10];
397 				if (base >= 10)
398 					*--s = digits[base / 10];
399 			}
400 			if (!(vp->flag & INT_U) && vp->val.i < 0)
401 				*--s = '-';
402 		}
403 		if (vp->flag & (RJUST|LJUST))
404 			/* case already dealt with */
405 			s = formatstr(vp, s);
406 		else
407 			strdupx(s, s, ATEMP);
408 	}
409 	return (s);
410 }
411 
412 /* set variable to string value */
413 int
setstr(struct tbl * vq,const char * s,int error_ok)414 setstr(struct tbl *vq, const char *s, int error_ok)
415 {
416 	char *salloc = NULL;
417 	bool no_ro_check = tobool(error_ok & 0x4);
418 
419 	error_ok &= ~0x4;
420 	if ((vq->flag & RDONLY) && !no_ro_check) {
421 		warningf(true, "read-only: %s", vq->name);
422 		if (!error_ok)
423 			errorfxz(2);
424 		return (0);
425 	}
426 	if (!(vq->flag&INTEGER)) {
427 		/* string dest */
428 		if ((vq->flag&ALLOC)) {
429 #ifndef MKSH_SMALL
430 			/* debugging */
431 			if (s >= vq->val.s &&
432 			    s <= vq->val.s + strlen(vq->val.s)) {
433 				internal_errorf(
434 				    "setstr: %s=%s: assigning to self",
435 				    vq->name, s);
436 			}
437 #endif
438 			afree(vq->val.s, vq->areap);
439 		}
440 		vq->flag &= ~(ISSET|ALLOC);
441 		vq->type = 0;
442 		if (s && (vq->flag & (UCASEV_AL|LCASEV|LJUST|RJUST)))
443 			s = salloc = formatstr(vq, s);
444 		if ((vq->flag&EXPORT))
445 			exportprep(vq, s);
446 		else {
447 			strdupx(vq->val.s, s, vq->areap);
448 			vq->flag |= ALLOC;
449 		}
450 	} else {
451 		/* integer dest */
452 		if (!v_evaluate(vq, s, error_ok, true))
453 			return (0);
454 	}
455 	vq->flag |= ISSET;
456 	if ((vq->flag&SPECIAL))
457 		setspec(vq);
458 	afree(salloc, ATEMP);
459 	return (1);
460 }
461 
462 /* set variable to integer */
463 void
setint(struct tbl * vq,mksh_ari_t n)464 setint(struct tbl *vq, mksh_ari_t n)
465 {
466 	if (!(vq->flag&INTEGER)) {
467 		struct tbl *vp = &vtemp;
468 		vp->flag = (ISSET|INTEGER);
469 		vp->type = 0;
470 		vp->areap = ATEMP;
471 		vp->val.i = n;
472 		/* setstr can't fail here */
473 		setstr(vq, str_val(vp), KSH_RETURN_ERROR);
474 	} else
475 		vq->val.i = n;
476 	vq->flag |= ISSET;
477 	if ((vq->flag&SPECIAL))
478 		setspec(vq);
479 }
480 
481 static int
getint(struct tbl * vp,mksh_ari_u * nump,bool arith)482 getint(struct tbl *vp, mksh_ari_u *nump, bool arith)
483 {
484 	mksh_uari_t c, num = 0, base = 10;
485 	const char *s;
486 	bool have_base = false, neg = false;
487 
488 	if (vp->flag & SPECIAL)
489 		getspec(vp);
490 	/* XXX is it possible for ISSET to be set and val.s to be NULL? */
491 	if (!(vp->flag & ISSET) || (!(vp->flag & INTEGER) && vp->val.s == NULL))
492 		return (-1);
493 	if (vp->flag & INTEGER) {
494 		nump->i = vp->val.i;
495 		return (vp->type);
496 	}
497 	s = vp->val.s + vp->type;
498 
499 	do {
500 		c = (unsigned char)*s++;
501 	} while (ksh_isspace(c));
502 
503 	switch (c) {
504 	case '-':
505 		neg = true;
506 		/* FALLTHROUGH */
507 	case '+':
508 		c = (unsigned char)*s++;
509 		break;
510 	}
511 
512 	if (c == '0' && arith) {
513 		if ((s[0] | 0x20) == 'x') {
514 			/* interpret as hexadecimal */
515 			base = 16;
516 			++s;
517 			goto getint_c_style_base;
518 		} else if (Flag(FPOSIX) && ksh_isdigit(s[0]) &&
519 		    !(vp->flag & ZEROFIL)) {
520 			/* interpret as octal (deprecated) */
521 			base = 8;
522  getint_c_style_base:
523 			have_base = true;
524 			c = (unsigned char)*s++;
525 		}
526 	}
527 
528 	do {
529 		if (c == '#') {
530 			/* ksh-style base determination */
531 			if (have_base || num < 1)
532 				return (-1);
533 			if ((base = num) == 1) {
534 				/* mksh-specific extension */
535 				unsigned int wc;
536 
537 				if (!UTFMODE)
538 					wc = *(const unsigned char *)s;
539 				else if (utf_mbtowc(&wc, s) == (size_t)-1)
540 					/* OPTU-8 -> OPTU-16 */
541 					/*
542 					 * (with a twist: 1#\uEF80 converts
543 					 * the same as 1#\x80 does, thus is
544 					 * not round-tripping correctly XXX)
545 					 */
546 					wc = 0xEF00 + *(const unsigned char *)s;
547 				nump->u = (mksh_uari_t)wc;
548 				return (1);
549 			} else if (base > 36)
550 				return (-1);
551 			num = 0;
552 			have_base = true;
553 			continue;
554 		}
555 		if (ksh_isdigit(c))
556 			c -= '0';
557 		else {
558 			c |= 0x20;
559 			if (!ksh_islower(c))
560 				return (-1);
561 			c -= 'a' - 10;
562 		}
563 		if (c >= base)
564 			return (-1);
565 		/* handle overflow as truncation */
566 		num = num * base + c;
567 	} while ((c = (unsigned char)*s++));
568 
569 	if (neg)
570 		num = -num;
571 	nump->u = num;
572 	return (base);
573 }
574 
575 /*
576  * convert variable vq to integer variable, setting its value from vp
577  * (vq and vp may be the same)
578  */
579 struct tbl *
setint_v(struct tbl * vq,struct tbl * vp,bool arith)580 setint_v(struct tbl *vq, struct tbl *vp, bool arith)
581 {
582 	int base;
583 	mksh_ari_u num;
584 
585 	if ((base = getint(vp, &num, arith)) == -1)
586 		return (NULL);
587 	setint_n(vq, num.i, 0);
588 	if (vq->type == 0)
589 		/* default base */
590 		vq->type = base;
591 	return (vq);
592 }
593 
594 /* convert variable vq to integer variable, setting its value to num */
595 void
setint_n(struct tbl * vq,mksh_ari_t num,int newbase)596 setint_n(struct tbl *vq, mksh_ari_t num, int newbase)
597 {
598 	if (!(vq->flag & INTEGER) && (vq->flag & ALLOC)) {
599 		vq->flag &= ~ALLOC;
600 		vq->type = 0;
601 		afree(vq->val.s, vq->areap);
602 	}
603 	vq->val.i = num;
604 	if (newbase != 0)
605 		vq->type = newbase;
606 	vq->flag |= ISSET|INTEGER;
607 	if (vq->flag&SPECIAL)
608 		setspec(vq);
609 }
610 
611 static char *
formatstr(struct tbl * vp,const char * s)612 formatstr(struct tbl *vp, const char *s)
613 {
614 	int olen, nlen;
615 	char *p, *q;
616 	size_t psiz;
617 
618 	olen = (int)utf_mbswidth(s);
619 
620 	if (vp->flag & (RJUST|LJUST)) {
621 		if (!vp->u2.field)
622 			/* default field width */
623 			vp->u2.field = olen;
624 		nlen = vp->u2.field;
625 	} else
626 		nlen = olen;
627 
628 	p = alloc((psiz = nlen * /* MB_LEN_MAX */ 3 + 1), ATEMP);
629 	if (vp->flag & (RJUST|LJUST)) {
630 		int slen = olen, i = 0;
631 
632 		if (vp->flag & RJUST) {
633 			const char *qq = s;
634 			int n = 0;
635 
636 			while (i < slen)
637 				i += utf_widthadj(qq, &qq);
638 			/* strip trailing spaces (AT&T uses qq[-1] == ' ') */
639 			while (qq > s && ksh_isspace(qq[-1])) {
640 				--qq;
641 				--slen;
642 			}
643 			if (vp->flag & ZEROFIL && vp->flag & INTEGER) {
644 				if (!s[0] || !s[1])
645 					goto uhm_no;
646 				if (s[1] == '#')
647 					n = 2;
648 				else if (s[2] == '#')
649 					n = 3;
650  uhm_no:
651 				if (vp->u2.field <= n)
652 					n = 0;
653 			}
654 			if (n) {
655 				memcpy(p, s, n);
656 				s += n;
657 			}
658 			while (slen > vp->u2.field)
659 				slen -= utf_widthadj(s, &s);
660 			if (vp->u2.field - slen)
661 				memset(p + n, (vp->flag & ZEROFIL) ? '0' : ' ',
662 				    vp->u2.field - slen);
663 			slen -= n;
664 			shf_snprintf(p + vp->u2.field - slen,
665 			    psiz - (vp->u2.field - slen),
666 			    "%.*s", slen, s);
667 		} else {
668 			/* strip leading spaces/zeros */
669 			while (ksh_isspace(*s))
670 				s++;
671 			if (vp->flag & ZEROFIL)
672 				while (*s == '0')
673 					s++;
674 			shf_snprintf(p, nlen + 1, "%-*.*s",
675 				vp->u2.field, vp->u2.field, s);
676 		}
677 	} else
678 		memcpy(p, s, strlen(s) + 1);
679 
680 	if (vp->flag & UCASEV_AL) {
681 		for (q = p; *q; q++)
682 			*q = ksh_toupper(*q);
683 	} else if (vp->flag & LCASEV) {
684 		for (q = p; *q; q++)
685 			*q = ksh_tolower(*q);
686 	}
687 
688 	return (p);
689 }
690 
691 /*
692  * make vp->val.s be "name=value" for quick exporting.
693  */
694 static void
exportprep(struct tbl * vp,const char * val)695 exportprep(struct tbl *vp, const char *val)
696 {
697 	char *xp;
698 	char *op = (vp->flag&ALLOC) ? vp->val.s : NULL;
699 	size_t namelen, vallen;
700 
701 	namelen = strlen(vp->name);
702 	vallen = strlen(val) + 1;
703 
704 	vp->flag |= ALLOC;
705 	/* since name+val are both in memory this can go unchecked */
706 	xp = alloc(namelen + 1 + vallen, vp->areap);
707 	memcpy(vp->val.s = xp, vp->name, namelen);
708 	xp += namelen;
709 	*xp++ = '=';
710 	/* offset to value */
711 	vp->type = xp - vp->val.s;
712 	memcpy(xp, val, vallen);
713 	if (op != NULL)
714 		afree(op, vp->areap);
715 }
716 
717 /*
718  * lookup variable (according to (set&LOCAL)), set its attributes
719  * (INTEGER, RDONLY, EXPORT, TRACE, LJUST, RJUST, ZEROFIL, LCASEV,
720  * UCASEV_AL), and optionally set its value if an assignment.
721  */
722 struct tbl *
typeset(const char * var,uint32_t set,uint32_t clr,int field,int base)723 typeset(const char *var, uint32_t set, uint32_t clr, int field, int base)
724 {
725 	struct tbl *vp;
726 	struct tbl *vpbase, *t;
727 	char *tvar;
728 	const char *val;
729 	size_t len;
730 	bool vappend = false;
731 	enum namerefflag new_refflag = SRF_NOP;
732 
733 	if ((set & (ARRAY | ASSOC)) == ASSOC) {
734 		new_refflag = SRF_ENABLE;
735 		set &= ~(ARRAY | ASSOC);
736 	}
737 	if ((clr & (ARRAY | ASSOC)) == ASSOC) {
738 		new_refflag = SRF_DISABLE;
739 		clr &= ~(ARRAY | ASSOC);
740 	}
741 
742 	/* check for valid variable name, search for value */
743 	val = skip_varname(var, false);
744 	if (val == var) {
745 		/* no variable name given */
746 		return (NULL);
747 	}
748 	if (*val == '[') {
749 		if (new_refflag != SRF_NOP)
750 			errorf("%s: %s", var,
751 			    "reference variable can't be an array");
752 		len = array_ref_len(val);
753 		if (len == 0)
754 			return (NULL);
755 		/*
756 		 * IMPORT is only used when the shell starts up and is
757 		 * setting up its environment. Allow only simple array
758 		 * references at this time since parameter/command
759 		 * substitution is performed on the [expression] which
760 		 * would be a major security hole.
761 		 */
762 		if (set & IMPORT) {
763 			size_t i;
764 
765 			for (i = 1; i < len - 1; i++)
766 				if (!ksh_isdigit(val[i]))
767 					return (NULL);
768 		}
769 		val += len;
770 	}
771 	if (val[0] == '=') {
772 		strndupx(tvar, var, val - var, ATEMP);
773 		++val;
774 	} else if (set & IMPORT) {
775 		/* environment invalid variable name or no assignment */
776 		return (NULL);
777 	} else if (val[0] == '+' && val[1] == '=') {
778 		strndupx(tvar, var, val - var, ATEMP);
779 		val += 2;
780 		vappend = true;
781 	} else if (val[0] != '\0') {
782 		/* other invalid variable names (not from environment) */
783 		return (NULL);
784 	} else {
785 		/* just varname with no value part nor equals sign */
786 		strdupx(tvar, var, ATEMP);
787 		val = NULL;
788 		/* handle foo[*] => foo (whole array) mapping for R39b */
789 		len = strlen(tvar);
790 		if (len > 3 && tvar[len - 3] == '[' && tvar[len - 2] == '*' &&
791 		    tvar[len - 1] == ']')
792 			tvar[len - 3] = '\0';
793 	}
794 
795 	if (new_refflag == SRF_ENABLE) {
796 		const char *qval, *ccp;
797 
798 		/* bail out on 'nameref foo+=bar' */
799 		if (vappend)
800 			errorf("appending not allowed for nameref");
801 		/* find value if variable already exists */
802 		if ((qval = val) == NULL) {
803 			varsearch(e->loc, &vp, tvar, hash(tvar));
804 			if (vp == NULL)
805 				goto nameref_empty;
806 			qval = str_val(vp);
807 		}
808 		/* check target value for being a valid variable name */
809 		ccp = skip_varname(qval, false);
810 		if (ccp == qval) {
811 			if (ksh_isdigit(qval[0])) {
812 				int c;
813 
814 				if (getn(qval, &c))
815 					goto nameref_rhs_checked;
816 			} else if (qval[1] == '\0') switch (qval[0]) {
817 			case '$':
818 			case '!':
819 			case '?':
820 			case '#':
821 			case '-':
822 				goto nameref_rhs_checked;
823 			}
824  nameref_empty:
825 			errorf("%s: %s", var, "empty nameref target");
826 		}
827 		len = (*ccp == '[') ? array_ref_len(ccp) : 0;
828 		if (ccp[len]) {
829 			/*
830 			 * works for cases "no array", "valid array with
831 			 * junk after it" and "invalid array"; in the
832 			 * latter case, len is also 0 and points to '['
833 			 */
834 			errorf("%s: %s", qval,
835 			    "nameref target not a valid parameter name");
836 		}
837  nameref_rhs_checked:
838 		/* prevent nameref loops */
839 		while (qval) {
840 			if (!strcmp(qval, tvar))
841 				errorf("%s: %s", qval,
842 				    "expression recurses on parameter");
843 			varsearch(e->loc, &vp, qval, hash(qval));
844 			qval = NULL;
845 			if (vp && ((vp->flag & (ARRAY | ASSOC)) == ASSOC))
846 				qval = str_val(vp);
847 		}
848 	}
849 
850 	/* prevent typeset from creating a local PATH/ENV/SHELL */
851 	if (Flag(FRESTRICTED) && (strcmp(tvar, "PATH") == 0 ||
852 	    strcmp(tvar, "ENV") == 0 || strcmp(tvar, "SHELL") == 0))
853 		errorf("%s: %s", tvar, "restricted");
854 
855 	innermost_refflag = new_refflag;
856 	vp = (set & LOCAL) ? local(tvar, tobool(set & LOCAL_COPY)) :
857 	    global(tvar);
858 	if (new_refflag == SRF_DISABLE && (vp->flag & (ARRAY|ASSOC)) == ASSOC)
859 		vp->flag &= ~ASSOC;
860 	else if (new_refflag == SRF_ENABLE) {
861 		if (vp->flag & ARRAY) {
862 			struct tbl *a, *tmp;
863 
864 			/* free up entire array */
865 			for (a = vp->u.array; a; ) {
866 				tmp = a;
867 				a = a->u.array;
868 				if (tmp->flag & ALLOC)
869 					afree(tmp->val.s, tmp->areap);
870 				afree(tmp, tmp->areap);
871 			}
872 			vp->u.array = NULL;
873 			vp->flag &= ~ARRAY;
874 		}
875 		vp->flag |= ASSOC;
876 	}
877 
878 	set &= ~(LOCAL|LOCAL_COPY);
879 
880 	vpbase = (vp->flag & ARRAY) ? global(arrayname(tvar)) : vp;
881 
882 	/*
883 	 * only allow export flag to be set; AT&T ksh allows any
884 	 * attribute to be changed which means it can be truncated or
885 	 * modified (-L/-R/-Z/-i)
886 	 */
887 	if ((vpbase->flag & RDONLY) &&
888 	    (val || clr || (set & ~EXPORT)))
889 		/* XXX check calls - is error here ok by POSIX? */
890 		errorfx(2, "read-only: %s", tvar);
891 	afree(tvar, ATEMP);
892 
893 	/* most calls are with set/clr == 0 */
894 	if (set | clr) {
895 		bool ok = true;
896 
897 		/*
898 		 * XXX if x[0] isn't set, there will be problems: need
899 		 * to have one copy of attributes for arrays...
900 		 */
901 		for (t = vpbase; t; t = t->u.array) {
902 			bool fake_assign;
903 			char *s = NULL;
904 			char *free_me = NULL;
905 
906 			fake_assign = (t->flag & ISSET) && (!val || t != vp) &&
907 			    ((set & (UCASEV_AL|LCASEV|LJUST|RJUST|ZEROFIL)) ||
908 			    ((t->flag & INTEGER) && (clr & INTEGER)) ||
909 			    (!(t->flag & INTEGER) && (set & INTEGER)));
910 			if (fake_assign) {
911 				if (t->flag & INTEGER) {
912 					s = str_val(t);
913 					free_me = NULL;
914 				} else {
915 					s = t->val.s + t->type;
916 					free_me = (t->flag & ALLOC) ? t->val.s :
917 					    NULL;
918 				}
919 				t->flag &= ~ALLOC;
920 			}
921 			if (!(t->flag & INTEGER) && (set & INTEGER)) {
922 				t->type = 0;
923 				t->flag &= ~ALLOC;
924 			}
925 			t->flag = (t->flag | set) & ~clr;
926 			/*
927 			 * Don't change base if assignment is to be
928 			 * done, in case assignment fails.
929 			 */
930 			if ((set & INTEGER) && base > 0 && (!val || t != vp))
931 				t->type = base;
932 			if (set & (LJUST|RJUST|ZEROFIL))
933 				t->u2.field = field;
934 			if (fake_assign) {
935 				if (!setstr(t, s, KSH_RETURN_ERROR)) {
936 					/*
937 					 * Somewhat arbitrary action
938 					 * here: zap contents of
939 					 * variable, but keep the flag
940 					 * settings.
941 					 */
942 					ok = false;
943 					if (t->flag & INTEGER)
944 						t->flag &= ~ISSET;
945 					else {
946 						if (t->flag & ALLOC)
947 							afree(t->val.s, t->areap);
948 						t->flag &= ~(ISSET|ALLOC);
949 						t->type = 0;
950 					}
951 				}
952 				if (free_me)
953 					afree(free_me, t->areap);
954 			}
955 		}
956 		if (!ok)
957 			errorfz();
958 	}
959 
960 	if (val != NULL) {
961 		char *tval;
962 
963 		if (vappend) {
964 			tval = shf_smprintf("%s%s", str_val(vp), val);
965 			val = tval;
966 		} else
967 			tval = NULL;
968 
969 		if (vp->flag&INTEGER) {
970 			/* do not zero base before assignment */
971 			setstr(vp, val, KSH_UNWIND_ERROR | 0x4);
972 			/* done after assignment to override default */
973 			if (base > 0)
974 				vp->type = base;
975 		} else
976 			/* setstr can't fail (readonly check already done) */
977 			setstr(vp, val, KSH_RETURN_ERROR | 0x4);
978 
979 		if (tval != NULL)
980 			afree(tval, ATEMP);
981 	}
982 
983 	/* only x[0] is ever exported, so use vpbase */
984 	if ((vpbase->flag&EXPORT) && !(vpbase->flag&INTEGER) &&
985 	    vpbase->type == 0)
986 		exportprep(vpbase, (vpbase->flag&ISSET) ? vpbase->val.s : null);
987 
988 	return (vp);
989 }
990 
991 /**
992  * Unset a variable. The flags can be:
993  * |1	= tear down entire array
994  * |2	= keep attributes, only unset content
995  */
996 void
unset(struct tbl * vp,int flags)997 unset(struct tbl *vp, int flags)
998 {
999 	if (vp->flag & ALLOC)
1000 		afree(vp->val.s, vp->areap);
1001 	if ((vp->flag & ARRAY) && (flags & 1)) {
1002 		struct tbl *a, *tmp;
1003 
1004 		/* free up entire array */
1005 		for (a = vp->u.array; a; ) {
1006 			tmp = a;
1007 			a = a->u.array;
1008 			if (tmp->flag & ALLOC)
1009 				afree(tmp->val.s, tmp->areap);
1010 			afree(tmp, tmp->areap);
1011 		}
1012 		vp->u.array = NULL;
1013 	}
1014 	if (flags & 2) {
1015 		vp->flag &= ~(ALLOC|ISSET);
1016 		return;
1017 	}
1018 	/* if foo[0] is being unset, the remainder of the array is kept... */
1019 	vp->flag &= SPECIAL | ((flags & 1) ? 0 : ARRAY|DEFINED);
1020 	if (vp->flag & SPECIAL)
1021 		/* responsible for 'unspecial'ing var */
1022 		unsetspec(vp);
1023 }
1024 
1025 /*
1026  * Return a pointer to the first char past a legal variable name
1027  * (returns the argument if there is no legal name, returns a pointer to
1028  * the terminating NUL if whole string is legal).
1029  */
1030 const char *
skip_varname(const char * s,bool aok)1031 skip_varname(const char *s, bool aok)
1032 {
1033 	size_t alen;
1034 
1035 	if (s && ksh_isalphx(*s)) {
1036 		while (*++s && ksh_isalnux(*s))
1037 			;
1038 		if (aok && *s == '[' && (alen = array_ref_len(s)))
1039 			s += alen;
1040 	}
1041 	return (s);
1042 }
1043 
1044 /* Return a pointer to the first character past any legal variable name */
1045 const char *
skip_wdvarname(const char * s,bool aok)1046 skip_wdvarname(const char *s,
1047     /* skip array de-reference? */
1048     bool aok)
1049 {
1050 	if (s[0] == CHAR && ksh_isalphx(s[1])) {
1051 		do {
1052 			s += 2;
1053 		} while (s[0] == CHAR && ksh_isalnux(s[1]));
1054 		if (aok && s[0] == CHAR && s[1] == '[') {
1055 			/* skip possible array de-reference */
1056 			const char *p = s;
1057 			char c;
1058 			int depth = 0;
1059 
1060 			while (/* CONSTCOND */ 1) {
1061 				if (p[0] != CHAR)
1062 					break;
1063 				c = p[1];
1064 				p += 2;
1065 				if (c == '[')
1066 					depth++;
1067 				else if (c == ']' && --depth == 0) {
1068 					s = p;
1069 					break;
1070 				}
1071 			}
1072 		}
1073 	}
1074 	return (s);
1075 }
1076 
1077 /* Check if coded string s is a variable name */
1078 int
is_wdvarname(const char * s,bool aok)1079 is_wdvarname(const char *s, bool aok)
1080 {
1081 	const char *p = skip_wdvarname(s, aok);
1082 
1083 	return (p != s && p[0] == EOS);
1084 }
1085 
1086 /* Check if coded string s is a variable assignment */
1087 int
is_wdvarassign(const char * s)1088 is_wdvarassign(const char *s)
1089 {
1090 	const char *p = skip_wdvarname(s, true);
1091 
1092 	return (p != s && p[0] == CHAR &&
1093 	    (p[1] == '=' || (p[1] == '+' && p[2] == CHAR && p[3] == '=')));
1094 }
1095 
1096 /*
1097  * Make the exported environment from the exported names in the dictionary.
1098  */
1099 char **
makenv(void)1100 makenv(void)
1101 {
1102 	ssize_t i;
1103 	struct block *l;
1104 	XPtrV denv;
1105 	struct tbl *vp, **vpp;
1106 
1107 	XPinit(denv, 64);
1108 	for (l = e->loc; l != NULL; l = l->next) {
1109 		vpp = l->vars.tbls;
1110 		i = 1 << (l->vars.tshift);
1111 		while (--i >= 0)
1112 			if ((vp = *vpp++) != NULL &&
1113 			    (vp->flag&(ISSET|EXPORT)) == (ISSET|EXPORT)) {
1114 				struct block *l2;
1115 				struct tbl *vp2;
1116 				uint32_t h = hash(vp->name);
1117 
1118 				/* unexport any redefined instances */
1119 				for (l2 = l->next; l2 != NULL; l2 = l2->next) {
1120 					vp2 = ktsearch(&l2->vars, vp->name, h);
1121 					if (vp2 != NULL)
1122 						vp2->flag &= ~EXPORT;
1123 				}
1124 				if ((vp->flag&INTEGER)) {
1125 					/* integer to string */
1126 					char *val;
1127 					val = str_val(vp);
1128 					vp->flag &= ~(INTEGER|RDONLY|SPECIAL);
1129 					/* setstr can't fail here */
1130 					setstr(vp, val, KSH_RETURN_ERROR);
1131 				}
1132 				XPput(denv, vp->val.s);
1133 			}
1134 		if (l->flags & BF_STOPENV)
1135 			break;
1136 	}
1137 	XPput(denv, NULL);
1138 	return ((char **)XPclose(denv));
1139 }
1140 
1141 /*
1142  * handle special variables with side effects - PATH, SECONDS.
1143  */
1144 
1145 /* Test if name is a special parameter */
1146 static int
special(const char * name)1147 special(const char *name)
1148 {
1149 	struct tbl *tp;
1150 
1151 	tp = ktsearch(&specials, name, hash(name));
1152 	return (tp && (tp->flag & ISSET) ? tp->type : V_NONE);
1153 }
1154 
1155 /* Make a variable non-special */
1156 static void
unspecial(const char * name)1157 unspecial(const char *name)
1158 {
1159 	struct tbl *tp;
1160 
1161 	tp = ktsearch(&specials, name, hash(name));
1162 	if (tp)
1163 		ktdelete(tp);
1164 }
1165 
1166 static time_t seconds;		/* time SECONDS last set */
1167 static mksh_uari_t user_lineno;	/* what user set $LINENO to */
1168 
1169 static void
getspec(struct tbl * vp)1170 getspec(struct tbl *vp)
1171 {
1172 	mksh_ari_u num;
1173 	int st;
1174 	struct timeval tv;
1175 
1176 	switch ((st = special(vp->name))) {
1177 	case V_COLUMNS:
1178 	case V_LINES:
1179 		/*
1180 		 * Do NOT export COLUMNS/LINES. Many applications
1181 		 * check COLUMNS/LINES before checking ws.ws_col/row,
1182 		 * so if the app is started with C/L in the environ
1183 		 * and the window is then resized, the app won't
1184 		 * see the change cause the environ doesn't change.
1185 		 */
1186 		if (got_winch)
1187 			change_winsz();
1188 		break;
1189 	}
1190 	switch (st) {
1191 	case V_BASHPID:
1192 		num.u = (mksh_uari_t)procpid;
1193 		break;
1194 	case V_COLUMNS:
1195 		num.i = x_cols;
1196 		break;
1197 	case V_HISTSIZE:
1198 		num.i = histsize;
1199 		break;
1200 	case V_LINENO:
1201 		num.u = (mksh_uari_t)current_lineno + user_lineno;
1202 		break;
1203 	case V_LINES:
1204 		num.i = x_lins;
1205 		break;
1206 	case V_EPOCHREALTIME: {
1207 		/* 10(%u) + 1(.) + 6 + NUL */
1208 		char buf[18];
1209 
1210 		vp->flag &= ~SPECIAL;
1211 		mksh_TIME(tv);
1212 		shf_snprintf(buf, sizeof(buf), "%u.%06u",
1213 		    (unsigned)tv.tv_sec, (unsigned)tv.tv_usec);
1214 		setstr(vp, buf, KSH_RETURN_ERROR | 0x4);
1215 		vp->flag |= SPECIAL;
1216 		return;
1217 	}
1218 	case V_OPTIND:
1219 		num.i = user_opt.uoptind;
1220 		break;
1221 	case V_RANDOM:
1222 		num.i = rndget();
1223 		break;
1224 	case V_SECONDS:
1225 		/*
1226 		 * On start up the value of SECONDS is used before
1227 		 * it has been set - don't do anything in this case
1228 		 * (see initcoms[] in main.c).
1229 		 */
1230 		if (vp->flag & ISSET) {
1231 			mksh_TIME(tv);
1232 			num.i = tv.tv_sec - seconds;
1233 		} else
1234 			return;
1235 		break;
1236 	default:
1237 		/* do nothing, do not touch vp at all */
1238 		return;
1239 	}
1240 	vp->flag &= ~SPECIAL;
1241 	setint_n(vp, num.i, 0);
1242 	vp->flag |= SPECIAL;
1243 }
1244 
1245 static void
setspec(struct tbl * vp)1246 setspec(struct tbl *vp)
1247 {
1248 	mksh_ari_u num;
1249 	char *s;
1250 	int st;
1251 
1252 	switch ((st = special(vp->name))) {
1253 #if HAVE_PERSISTENT_HISTORY
1254 	case V_HISTFILE:
1255 		sethistfile(str_val(vp));
1256 		return;
1257 #endif
1258 	case V_IFS:
1259 		setctypes(s = str_val(vp), C_IFS);
1260 		ifs0 = *s;
1261 		return;
1262 	case V_PATH:
1263 		if (path)
1264 			afree(path, APERM);
1265 		s = str_val(vp);
1266 		strdupx(path, s, APERM);
1267 		/* clear tracked aliases */
1268 		flushcom(true);
1269 		return;
1270 	case V_TMPDIR:
1271 		if (tmpdir) {
1272 			afree(tmpdir, APERM);
1273 			tmpdir = NULL;
1274 		}
1275 		/*
1276 		 * Use tmpdir iff it is an absolute path, is writable
1277 		 * and searchable and is a directory...
1278 		 */
1279 		{
1280 			struct stat statb;
1281 
1282 			s = str_val(vp);
1283 			/* LINTED use of access */
1284 			if (s[0] == '/' && access(s, W_OK|X_OK) == 0 &&
1285 			    stat(s, &statb) == 0 && S_ISDIR(statb.st_mode))
1286 				strdupx(tmpdir, s, APERM);
1287 		}
1288 		return;
1289 	/* common sub-cases */
1290 	case V_COLUMNS:
1291 	case V_LINES:
1292 		if (vp->flag & IMPORT) {
1293 			/* do not touch */
1294 			unspecial(vp->name);
1295 			vp->flag &= ~SPECIAL;
1296 			return;
1297 		}
1298 		/* FALLTHROUGH */
1299 	case V_HISTSIZE:
1300 	case V_LINENO:
1301 	case V_OPTIND:
1302 	case V_RANDOM:
1303 	case V_SECONDS:
1304 	case V_TMOUT:
1305 		vp->flag &= ~SPECIAL;
1306 		if (getint(vp, &num, false) == -1) {
1307 			s = str_val(vp);
1308 			if (st != V_RANDOM)
1309 				errorf("%s: %s: %s", vp->name, "bad number", s);
1310 			num.u = hash(s);
1311 		}
1312 		vp->flag |= SPECIAL;
1313 		break;
1314 	default:
1315 		/* do nothing, do not touch vp at all */
1316 		return;
1317 	}
1318 
1319 	/* process the singular parts of the common cases */
1320 
1321 	switch (st) {
1322 	case V_COLUMNS:
1323 		if (num.i >= MIN_COLS)
1324 			x_cols = num.i;
1325 		break;
1326 	case V_HISTSIZE:
1327 		sethistsize(num.i);
1328 		break;
1329 	case V_LINENO:
1330 		/* The -1 is because line numbering starts at 1. */
1331 		user_lineno = num.u - (mksh_uari_t)current_lineno - 1;
1332 		break;
1333 	case V_LINES:
1334 		if (num.i >= MIN_LINS)
1335 			x_lins = num.i;
1336 		break;
1337 	case V_OPTIND:
1338 		getopts_reset((int)num.i);
1339 		break;
1340 	case V_RANDOM:
1341 		/*
1342 		 * mksh R39d+ no longer has the traditional repeatability
1343 		 * of $RANDOM sequences, but always retains state
1344 		 */
1345 		rndset((unsigned long)num.u);
1346 		break;
1347 	case V_SECONDS:
1348 		{
1349 			struct timeval tv;
1350 
1351 			mksh_TIME(tv);
1352 			seconds = tv.tv_sec - num.i;
1353 		}
1354 		break;
1355 	case V_TMOUT:
1356 		ksh_tmout = num.i >= 0 ? num.i : 0;
1357 		break;
1358 	}
1359 }
1360 
1361 static void
unsetspec(struct tbl * vp)1362 unsetspec(struct tbl *vp)
1363 {
1364 	/*
1365 	 * AT&T ksh man page says OPTIND, OPTARG and _ lose special
1366 	 * meaning, but OPTARG does not (still set by getopts) and _ is
1367 	 * also still set in various places. Don't know what AT&T does
1368 	 * for HISTSIZE, HISTFILE. Unsetting these in AT&T ksh does not
1369 	 * loose the 'specialness': IFS, COLUMNS, PATH, TMPDIR
1370 	 */
1371 
1372 	switch (special(vp->name)) {
1373 #if HAVE_PERSISTENT_HISTORY
1374 	case V_HISTFILE:
1375 		sethistfile(NULL);
1376 		return;
1377 #endif
1378 	case V_IFS:
1379 		setctypes(TC_IFSWS, C_IFS);
1380 		ifs0 = ' ';
1381 		break;
1382 	case V_PATH:
1383 		if (path)
1384 			afree(path, APERM);
1385 		strdupx(path, def_path, APERM);
1386 		/* clear tracked aliases */
1387 		flushcom(true);
1388 		break;
1389 	case V_TMPDIR:
1390 		/* should not become unspecial */
1391 		if (tmpdir) {
1392 			afree(tmpdir, APERM);
1393 			tmpdir = NULL;
1394 		}
1395 		break;
1396 	case V_LINENO:
1397 	case V_RANDOM:
1398 	case V_SECONDS:
1399 	case V_TMOUT:
1400 		/* AT&T ksh leaves previous value in place */
1401 		unspecial(vp->name);
1402 		break;
1403 	}
1404 }
1405 
1406 /*
1407  * Search for (and possibly create) a table entry starting with
1408  * vp, indexed by val.
1409  */
1410 struct tbl *
arraysearch(struct tbl * vp,uint32_t val)1411 arraysearch(struct tbl *vp, uint32_t val)
1412 {
1413 	struct tbl *prev, *curr, *news;
1414 	size_t len;
1415 
1416 	vp->flag = (vp->flag | (ARRAY | DEFINED)) & ~ASSOC;
1417 	/* the table entry is always [0] */
1418 	if (val == 0)
1419 		return (vp);
1420 	prev = vp;
1421 	curr = vp->u.array;
1422 	while (curr && curr->ua.index < val) {
1423 		prev = curr;
1424 		curr = curr->u.array;
1425 	}
1426 	if (curr && curr->ua.index == val) {
1427 		if (curr->flag&ISSET)
1428 			return (curr);
1429 		news = curr;
1430 	} else
1431 		news = NULL;
1432 	if (!news) {
1433 		len = strlen(vp->name);
1434 		checkoktoadd(len, 1 + offsetof(struct tbl, name[0]));
1435 		news = alloc(offsetof(struct tbl, name[0]) + ++len, vp->areap);
1436 		memcpy(news->name, vp->name, len);
1437 	}
1438 	news->flag = (vp->flag & ~(ALLOC|DEFINED|ISSET|SPECIAL)) | AINDEX;
1439 	news->type = vp->type;
1440 	news->areap = vp->areap;
1441 	news->u2.field = vp->u2.field;
1442 	news->ua.index = val;
1443 
1444 	if (curr != news) {
1445 		/* not reusing old array entry */
1446 		prev->u.array = news;
1447 		news->u.array = curr;
1448 	}
1449 	return (news);
1450 }
1451 
1452 /*
1453  * Return the length of an array reference (eg, [1+2]) - cp is assumed
1454  * to point to the open bracket. Returns 0 if there is no matching
1455  * closing bracket.
1456  *
1457  * XXX this should parse the actual arithmetic syntax
1458  */
1459 size_t
array_ref_len(const char * cp)1460 array_ref_len(const char *cp)
1461 {
1462 	const char *s = cp;
1463 	char c;
1464 	int depth = 0;
1465 
1466 	while ((c = *s++) && (c != ']' || --depth))
1467 		if (c == '[')
1468 			depth++;
1469 	if (!c)
1470 		return (0);
1471 	return (s - cp);
1472 }
1473 
1474 /*
1475  * Make a copy of the base of an array name
1476  */
1477 char *
arrayname(const char * str)1478 arrayname(const char *str)
1479 {
1480 	const char *p;
1481 	char *rv;
1482 
1483 	if ((p = cstrchr(str, '[')) == 0)
1484 		/* Shouldn't happen, but why worry? */
1485 		strdupx(rv, str, ATEMP);
1486 	else
1487 		strndupx(rv, str, p - str, ATEMP);
1488 
1489 	return (rv);
1490 }
1491 
1492 /* set (or overwrite, if reset) the array variable var to the values in vals */
1493 mksh_uari_t
set_array(const char * var,bool reset,const char ** vals)1494 set_array(const char *var, bool reset, const char **vals)
1495 {
1496 	struct tbl *vp, *vq;
1497 	mksh_uari_t i = 0, j = 0;
1498 	const char *ccp = var;
1499 	char *cp = NULL;
1500 	size_t n;
1501 
1502 	/* to get local array, use "local foo; set -A foo" */
1503 	n = strlen(var);
1504 	if (n > 0 && var[n - 1] == '+') {
1505 		/* append mode */
1506 		reset = false;
1507 		strndupx(cp, var, n - 1, ATEMP);
1508 		ccp = cp;
1509 	}
1510 	vp = global(ccp);
1511 
1512 	/* Note: AT&T ksh allows set -A but not set +A of a read-only var */
1513 	if ((vp->flag&RDONLY))
1514 		errorfx(2, "read-only: %s", ccp);
1515 	/* This code is quite non-optimal */
1516 	if (reset) {
1517 		/* trash existing values and attributes */
1518 		unset(vp, 1);
1519 		/* allocate-by-access the [0] element to keep in scope */
1520 		arraysearch(vp, 0);
1521 	}
1522 	/*
1523 	 * TODO: would be nice for assignment to completely succeed or
1524 	 * completely fail. Only really effects integer arrays:
1525 	 * evaluation of some of vals[] may fail...
1526 	 */
1527 	if (cp != NULL) {
1528 		/* find out where to set when appending */
1529 		for (vq = vp; vq; vq = vq->u.array) {
1530 			if (!(vq->flag & ISSET))
1531 				continue;
1532 			if (arrayindex(vq) >= j)
1533 				j = arrayindex(vq) + 1;
1534 		}
1535 		afree(cp, ATEMP);
1536 	}
1537 	while ((ccp = vals[i])) {
1538 #if 0 /* temporarily taken out due to regression */
1539 		if (*ccp == '[') {
1540 			int level = 0;
1541 
1542 			while (*ccp) {
1543 				if (*ccp == ']' && --level == 0)
1544 					break;
1545 				if (*ccp == '[')
1546 					++level;
1547 				++ccp;
1548 			}
1549 			if (*ccp == ']' && level == 0 && ccp[1] == '=') {
1550 				strndupx(cp, vals[i] + 1, ccp - (vals[i] + 1),
1551 				    ATEMP);
1552 				evaluate(substitute(cp, 0), (mksh_ari_t *)&j,
1553 				    KSH_UNWIND_ERROR, true);
1554 				afree(cp, ATEMP);
1555 				ccp += 2;
1556 			} else
1557 				ccp = vals[i];
1558 		}
1559 #endif
1560 
1561 		vq = arraysearch(vp, j);
1562 		/* would be nice to deal with errors here... (see above) */
1563 		setstr(vq, ccp, KSH_RETURN_ERROR);
1564 		i++;
1565 		j++;
1566 	}
1567 
1568 	return (i);
1569 }
1570 
1571 void
change_winsz(void)1572 change_winsz(void)
1573 {
1574 	struct timeval tv;
1575 
1576 	mksh_TIME(tv);
1577 	BAFHUpdateMem_mem(qh_state, &tv, sizeof(tv));
1578 
1579 #ifdef TIOCGWINSZ
1580 	/* check if window size has changed */
1581 	if (tty_init_fd() < 2) {
1582 		struct winsize ws;
1583 
1584 		if (ioctl(tty_fd, TIOCGWINSZ, &ws) >= 0) {
1585 			if (ws.ws_col)
1586 				x_cols = ws.ws_col;
1587 			if (ws.ws_row)
1588 				x_lins = ws.ws_row;
1589 		}
1590 	}
1591 #endif
1592 
1593 	/* bounds check for sane values, use defaults otherwise */
1594 	if (x_cols < MIN_COLS)
1595 		x_cols = 80;
1596 	if (x_lins < MIN_LINS)
1597 		x_lins = 24;
1598 
1599 #ifdef SIGWINCH
1600 	got_winch = 0;
1601 #endif
1602 }
1603 
1604 uint32_t
hash(const void * s)1605 hash(const void *s)
1606 {
1607 	register uint32_t h;
1608 
1609 	BAFHInit(h);
1610 	BAFHUpdateStr_reg(h, s);
1611 	BAFHFinish_reg(h);
1612 	return (h);
1613 }
1614 
1615 uint32_t
chvt_rndsetup(const void * bp,size_t sz)1616 chvt_rndsetup(const void *bp, size_t sz)
1617 {
1618 	register uint32_t h;
1619 
1620 	/* use LCG as seed but try to get them to deviate immediately */
1621 	h = lcg_state;
1622 	(void)rndget();
1623 	BAFHFinish_reg(h);
1624 	/* variation through pid, ppid, and the works */
1625 	BAFHUpdateMem_reg(h, &rndsetupstate, sizeof(rndsetupstate));
1626 	/* some variation, some possibly entropy, depending on OE */
1627 	BAFHUpdateMem_reg(h, bp, sz);
1628 	/* mix them all up */
1629 	BAFHFinish_reg(h);
1630 
1631 	return (h);
1632 }
1633 
1634 mksh_ari_t
rndget(void)1635 rndget(void)
1636 {
1637 	/*
1638 	 * this is the same Linear Congruential PRNG as Borland
1639 	 * C/C++ allegedly uses in its built-in rand() function
1640 	 */
1641 	return (((lcg_state = 22695477 * lcg_state + 1) >> 16) & 0x7FFF);
1642 }
1643 
1644 void
rndset(unsigned long v)1645 rndset(unsigned long v)
1646 {
1647 	register uint32_t h;
1648 #if defined(arc4random_pushb_fast) || defined(MKSH_A4PB)
1649 	register uint32_t t;
1650 #endif
1651 	struct {
1652 		struct timeval tv;
1653 		void *sp;
1654 		uint32_t qh;
1655 		pid_t pp;
1656 		short r;
1657 	} z;
1658 
1659 #ifdef DEBUG
1660 	/* clear the allocated space, for valgrind */
1661 	memset(&z, 0, sizeof(z));
1662 #endif
1663 
1664 	h = lcg_state;
1665 	BAFHFinish_reg(h);
1666 	BAFHUpdateMem_reg(h, &v, sizeof(v));
1667 
1668 	mksh_TIME(z.tv);
1669 	z.sp = &lcg_state;
1670 	z.pp = procpid;
1671 	z.r = (short)rndget();
1672 
1673 #if defined(arc4random_pushb_fast) || defined(MKSH_A4PB)
1674 	t = qh_state;
1675 	BAFHFinish_reg(t);
1676 	z.qh = (t & 0xFFFF8000) | rndget();
1677 	lcg_state = (t << 15) | rndget();
1678 	/*
1679 	 * either we have very chap entropy get and push available,
1680 	 * with malloc() pulling in this code already anyway, or the
1681 	 * user requested us to use the old functions
1682 	 */
1683 	t = h;
1684 	BAFHUpdateMem_reg(t, &lcg_state, sizeof(lcg_state));
1685 	BAFHFinish_reg(t);
1686 	lcg_state = t;
1687 #if defined(arc4random_pushb_fast)
1688 	arc4random_pushb_fast(&lcg_state, sizeof(lcg_state));
1689 	lcg_state = arc4random();
1690 #else
1691 	lcg_state = arc4random_pushb(&lcg_state, sizeof(lcg_state));
1692 #endif
1693 	BAFHUpdateMem_reg(h, &lcg_state, sizeof(lcg_state));
1694 #else
1695 	z.qh = qh_state;
1696 #endif
1697 
1698 	BAFHUpdateMem_reg(h, &z, sizeof(z));
1699 	BAFHFinish_reg(h);
1700 	lcg_state = h;
1701 }
1702 
1703 void
rndpush(const void * s)1704 rndpush(const void *s)
1705 {
1706 	register uint32_t h = qh_state;
1707 
1708 	BAFHUpdateStr_reg(h, s);
1709 	BAFHUpdateOctet_reg(h, 0);
1710 	qh_state = h;
1711 }
1712