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1 /*	$OpenBSD: var.c,v 1.44 2015/09/10 11:37:42 jca Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
5  *		 2011, 2012, 2013, 2014, 2015, 2016
6  *	mirabilos <m@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 1.209 2016/11/11 23:31:39 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 18 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(Tf_ss, 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 #define vn vname.ro
222 /*
223  * Search for variable, if not found create globally.
224  */
225 struct tbl *
global(const char * n)226 global(const char *n)
227 {
228 	struct tbl *vp;
229 	union mksh_cchack vname;
230 	struct block *l = e->loc;
231 	int c;
232 	bool array;
233 	uint32_t h, val;
234 
235 	/*
236 	 * check to see if this is an array;
237 	 * dereference namerefs; must come first
238 	 */
239 	vn = array_index_calc(n, &array, &val);
240 	h = hash(vn);
241 	c = (unsigned char)vn[0];
242 	if (!ksh_isalphx(c)) {
243 		if (array)
244 			errorf(Tbadsubst);
245 		vp = vtemp;
246 		vp->flag = DEFINED;
247 		vp->type = 0;
248 		vp->areap = ATEMP;
249 		if (ksh_isdigit(c)) {
250 			if (getn(vn, &c)) {
251 				/* main.c:main_init() says 12 */
252 				shf_snprintf(vp->name, 12, Tf_d, c);
253 				if (c <= l->argc) {
254 					/* setstr can't fail here */
255 					setstr(vp, l->argv[c],
256 					    KSH_RETURN_ERROR);
257 				}
258 			} else
259 				vp->name[0] = '\0';
260 			vp->flag |= RDONLY;
261 			goto out;
262 		}
263 		vp->name[0] = c;
264 		vp->name[1] = '\0';
265 		vp->flag |= RDONLY;
266 		if (vn[1] != '\0')
267 			goto out;
268 		vp->flag |= ISSET|INTEGER;
269 		switch (c) {
270 		case '$':
271 			vp->val.i = kshpid;
272 			break;
273 		case '!':
274 			/* if no job, expand to nothing */
275 			if ((vp->val.i = j_async()) == 0)
276 				vp->flag &= ~(ISSET|INTEGER);
277 			break;
278 		case '?':
279 			vp->val.i = exstat & 0xFF;
280 			break;
281 		case '#':
282 			vp->val.i = l->argc;
283 			break;
284 		case '-':
285 			vp->flag &= ~INTEGER;
286 			vp->val.s = getoptions();
287 			break;
288 		default:
289 			vp->flag &= ~(ISSET|INTEGER);
290 		}
291 		goto out;
292 	}
293 	l = varsearch(e->loc, &vp, vn, h);
294 	if (vp != NULL) {
295 		if (array)
296 			vp = arraysearch(vp, val);
297 		goto out;
298 	}
299 	vp = ktenter(&l->vars, vn, h);
300 	if (array)
301 		vp = arraysearch(vp, val);
302 	vp->flag |= DEFINED;
303 	if (special(vn))
304 		vp->flag |= SPECIAL;
305  out:
306 	last_lookup_was_array = array;
307 	if (vn != n)
308 		afree(vname.rw, ATEMP);
309 	return (vp);
310 }
311 
312 /*
313  * Search for local variable, if not found create locally.
314  */
315 struct tbl *
local(const char * n,bool copy)316 local(const char *n, bool copy)
317 {
318 	struct tbl *vp;
319 	union mksh_cchack vname;
320 	struct block *l = e->loc;
321 	bool array;
322 	uint32_t h, val;
323 
324 	/*
325 	 * check to see if this is an array;
326 	 * dereference namerefs; must come first
327 	 */
328 	vn = array_index_calc(n, &array, &val);
329 	h = hash(vn);
330 	if (!ksh_isalphx(*vn)) {
331 		vp = vtemp;
332 		vp->flag = DEFINED|RDONLY;
333 		vp->type = 0;
334 		vp->areap = ATEMP;
335 		goto out;
336 	}
337 	vp = ktenter(&l->vars, vn, h);
338 	if (copy && !(vp->flag & DEFINED)) {
339 		struct tbl *vq;
340 
341 		varsearch(l->next, &vq, vn, h);
342 		if (vq != NULL) {
343 			vp->flag |= vq->flag &
344 			    (EXPORT | INTEGER | RDONLY | LJUST | RJUST |
345 			    ZEROFIL | LCASEV | UCASEV_AL | INT_U | INT_L);
346 			if (vq->flag & INTEGER)
347 				vp->type = vq->type;
348 			vp->u2.field = vq->u2.field;
349 		}
350 	}
351 	if (array)
352 		vp = arraysearch(vp, val);
353 	vp->flag |= DEFINED;
354 	if (special(vn))
355 		vp->flag |= SPECIAL;
356  out:
357 	last_lookup_was_array = array;
358 	if (vn != n)
359 		afree(vname.rw, ATEMP);
360 	return (vp);
361 }
362 #undef vn
363 
364 /* get variable string value */
365 char *
str_val(struct tbl * vp)366 str_val(struct tbl *vp)
367 {
368 	char *s;
369 
370 	if ((vp->flag&SPECIAL))
371 		getspec(vp);
372 	if (!(vp->flag&ISSET))
373 		/* special to dollar() */
374 		s = null;
375 	else if (!(vp->flag&INTEGER))
376 		/* string source */
377 		s = vp->val.s + vp->type;
378 	else {
379 		/* integer source */
380 		mksh_uari_t n;
381 		unsigned int base;
382 		/**
383 		 * worst case number length is when base == 2:
384 		 *	1 (minus) + 2 (base, up to 36) + 1 ('#') +
385 		 *	number of bits in the mksh_uari_t + 1 (NUL)
386 		 */
387 		char strbuf[1 + 2 + 1 + 8 * sizeof(mksh_uari_t) + 1];
388 		const char *digits = (vp->flag & UCASEV_AL) ?
389 		    digits_uc : digits_lc;
390 
391 		s = strbuf + sizeof(strbuf);
392 		if (vp->flag & INT_U)
393 			n = vp->val.u;
394 		else
395 			n = (vp->val.i < 0) ? -vp->val.u : vp->val.u;
396 		base = (vp->type == 0) ? 10U : (unsigned int)vp->type;
397 
398 		if (base == 1 && n == 0)
399 			base = 2;
400 		if (base == 1) {
401 			size_t sz = 1;
402 
403 			*(s = strbuf) = '1';
404 			s[1] = '#';
405 			if (!UTFMODE || ((n & 0xFF80) == 0xEF80))
406 				/* OPTU-16 -> raw octet */
407 				s[2] = n & 0xFF;
408 			else
409 				sz = utf_wctomb(s + 2, n);
410 			s[2 + sz] = '\0';
411 		} else {
412 			*--s = '\0';
413 			do {
414 				*--s = digits[n % base];
415 				n /= base;
416 			} while (n != 0);
417 			if (base != 10) {
418 				*--s = '#';
419 				*--s = digits[base % 10];
420 				if (base >= 10)
421 					*--s = digits[base / 10];
422 			}
423 			if (!(vp->flag & INT_U) && vp->val.i < 0)
424 				*--s = '-';
425 		}
426 		if (vp->flag & (RJUST|LJUST))
427 			/* case already dealt with */
428 			s = formatstr(vp, s);
429 		else
430 			strdupx(s, s, ATEMP);
431 	}
432 	return (s);
433 }
434 
435 /* set variable to string value */
436 int
setstr(struct tbl * vq,const char * s,int error_ok)437 setstr(struct tbl *vq, const char *s, int error_ok)
438 {
439 	char *salloc = NULL;
440 	bool no_ro_check = tobool(error_ok & 0x4);
441 
442 	error_ok &= ~0x4;
443 	if ((vq->flag & RDONLY) && !no_ro_check) {
444 		warningf(true, Tf_ro, vq->name);
445 		if (!error_ok)
446 			errorfxz(2);
447 		return (0);
448 	}
449 	if (!(vq->flag&INTEGER)) {
450 		/* string dest */
451 		if ((vq->flag&ALLOC)) {
452 #ifndef MKSH_SMALL
453 			/* debugging */
454 			if (s >= vq->val.s &&
455 			    s <= vq->val.s + strlen(vq->val.s)) {
456 				internal_errorf(
457 				    "setstr: %s=%s: assigning to self",
458 				    vq->name, s);
459 			}
460 #endif
461 			afree(vq->val.s, vq->areap);
462 		}
463 		vq->flag &= ~(ISSET|ALLOC);
464 		vq->type = 0;
465 		if (s && (vq->flag & (UCASEV_AL|LCASEV|LJUST|RJUST)))
466 			s = salloc = formatstr(vq, s);
467 		if ((vq->flag&EXPORT))
468 			exportprep(vq, s);
469 		else {
470 			strdupx(vq->val.s, s, vq->areap);
471 			vq->flag |= ALLOC;
472 		}
473 	} else {
474 		/* integer dest */
475 		if (!v_evaluate(vq, s, error_ok, true))
476 			return (0);
477 	}
478 	vq->flag |= ISSET;
479 	if ((vq->flag&SPECIAL))
480 		setspec(vq);
481 	afree(salloc, ATEMP);
482 	return (1);
483 }
484 
485 /* set variable to integer */
486 void
setint(struct tbl * vq,mksh_ari_t n)487 setint(struct tbl *vq, mksh_ari_t n)
488 {
489 	if (!(vq->flag&INTEGER)) {
490 		vtemp->flag = (ISSET|INTEGER);
491 		vtemp->type = 0;
492 		vtemp->areap = ATEMP;
493 		vtemp->val.i = n;
494 		/* setstr can't fail here */
495 		setstr(vq, str_val(vtemp), KSH_RETURN_ERROR);
496 	} else
497 		vq->val.i = n;
498 	vq->flag |= ISSET;
499 	if ((vq->flag&SPECIAL))
500 		setspec(vq);
501 }
502 
503 static int
getint(struct tbl * vp,mksh_ari_u * nump,bool arith)504 getint(struct tbl *vp, mksh_ari_u *nump, bool arith)
505 {
506 	mksh_uari_t c, num = 0, base = 10;
507 	const char *s;
508 	bool have_base = false, neg = false;
509 
510 	if (vp->flag & SPECIAL)
511 		getspec(vp);
512 	/* XXX is it possible for ISSET to be set and val.s to be NULL? */
513 	if (!(vp->flag & ISSET) || (!(vp->flag & INTEGER) && vp->val.s == NULL))
514 		return (-1);
515 	if (vp->flag & INTEGER) {
516 		nump->i = vp->val.i;
517 		return (vp->type);
518 	}
519 	s = vp->val.s + vp->type;
520 
521 	do {
522 		c = (unsigned char)*s++;
523 	} while (ksh_isspace(c));
524 
525 	switch (c) {
526 	case '-':
527 		neg = true;
528 		/* FALLTHROUGH */
529 	case '+':
530 		c = (unsigned char)*s++;
531 		break;
532 	}
533 
534 	if (c == '0' && arith) {
535 		if (ksh_eq(s[0], 'X', 'x')) {
536 			/* interpret as hexadecimal */
537 			base = 16;
538 			++s;
539 			goto getint_c_style_base;
540 		} else if (Flag(FPOSIX) && ksh_isdigit(s[0]) &&
541 		    !(vp->flag & ZEROFIL)) {
542 			/* interpret as octal (deprecated) */
543 			base = 8;
544  getint_c_style_base:
545 			have_base = true;
546 			c = (unsigned char)*s++;
547 		}
548 	}
549 
550 	do {
551 		if (c == '#') {
552 			/* ksh-style base determination */
553 			if (have_base || num < 1)
554 				return (-1);
555 			if ((base = num) == 1) {
556 				/* mksh-specific extension */
557 				unsigned int wc;
558 
559 				if (!UTFMODE)
560 					wc = *(const unsigned char *)s;
561 				else if (utf_mbtowc(&wc, s) == (size_t)-1)
562 					/* OPTU-8 -> OPTU-16 */
563 					/*
564 					 * (with a twist: 1#\uEF80 converts
565 					 * the same as 1#\x80 does, thus is
566 					 * not round-tripping correctly XXX)
567 					 */
568 					wc = 0xEF00 + *(const unsigned char *)s;
569 				nump->u = (mksh_uari_t)wc;
570 				return (1);
571 			} else if (base > 36)
572 				base = 10;
573 			num = 0;
574 			have_base = true;
575 			continue;
576 		}
577 		if (ksh_isdigit(c))
578 			c = ksh_numdig(c);
579 		else if (ksh_isupper(c))
580 			c = ksh_numuc(c) + 10;
581 		else if (ksh_islower(c))
582 			c = ksh_numlc(c) + 10;
583 		else
584 			return (-1);
585 		if (c >= base)
586 			return (-1);
587 		/* handle overflow as truncation */
588 		num = num * base + c;
589 	} while ((c = (unsigned char)*s++));
590 
591 	if (neg)
592 		num = -num;
593 	nump->u = num;
594 	return (base);
595 }
596 
597 /*
598  * convert variable vq to integer variable, setting its value from vp
599  * (vq and vp may be the same)
600  */
601 struct tbl *
setint_v(struct tbl * vq,struct tbl * vp,bool arith)602 setint_v(struct tbl *vq, struct tbl *vp, bool arith)
603 {
604 	int base;
605 	mksh_ari_u num;
606 
607 	if ((base = getint(vp, &num, arith)) == -1)
608 		return (NULL);
609 	setint_n(vq, num.i, 0);
610 	if (vq->type == 0)
611 		/* default base */
612 		vq->type = base;
613 	return (vq);
614 }
615 
616 /* convert variable vq to integer variable, setting its value to num */
617 void
setint_n(struct tbl * vq,mksh_ari_t num,int newbase)618 setint_n(struct tbl *vq, mksh_ari_t num, int newbase)
619 {
620 	if (!(vq->flag & INTEGER) && (vq->flag & ALLOC)) {
621 		vq->flag &= ~ALLOC;
622 		vq->type = 0;
623 		afree(vq->val.s, vq->areap);
624 	}
625 	vq->val.i = num;
626 	if (newbase != 0)
627 		vq->type = newbase;
628 	vq->flag |= ISSET|INTEGER;
629 	if (vq->flag&SPECIAL)
630 		setspec(vq);
631 }
632 
633 static char *
formatstr(struct tbl * vp,const char * s)634 formatstr(struct tbl *vp, const char *s)
635 {
636 	int olen, nlen;
637 	char *p, *q;
638 	size_t psiz;
639 
640 	olen = (int)utf_mbswidth(s);
641 
642 	if (vp->flag & (RJUST|LJUST)) {
643 		if (!vp->u2.field)
644 			/* default field width */
645 			vp->u2.field = olen;
646 		nlen = vp->u2.field;
647 	} else
648 		nlen = olen;
649 
650 	p = alloc((psiz = nlen * /* MB_LEN_MAX */ 3 + 1), ATEMP);
651 	if (vp->flag & (RJUST|LJUST)) {
652 		int slen = olen;
653 
654 		if (vp->flag & RJUST) {
655 			const char *qq;
656 			int n = 0;
657 
658 			qq = utf_skipcols(s, slen, &slen);
659 
660 			/* strip trailing spaces (AT&T uses qq[-1] == ' ') */
661 			while (qq > s && ksh_isspace(qq[-1])) {
662 				--qq;
663 				--slen;
664 			}
665 			if (vp->flag & ZEROFIL && vp->flag & INTEGER) {
666 				if (!s[0] || !s[1])
667 					goto uhm_no;
668 				if (s[1] == '#')
669 					n = 2;
670 				else if (s[2] == '#')
671 					n = 3;
672  uhm_no:
673 				if (vp->u2.field <= n)
674 					n = 0;
675 			}
676 			if (n) {
677 				memcpy(p, s, n);
678 				s += n;
679 			}
680 			while (slen > vp->u2.field)
681 				slen -= utf_widthadj(s, &s);
682 			if (vp->u2.field - slen)
683 				memset(p + n, (vp->flag & ZEROFIL) ? '0' : ' ',
684 				    vp->u2.field - slen);
685 			slen -= n;
686 			shf_snprintf(p + vp->u2.field - slen,
687 			    psiz - (vp->u2.field - slen),
688 			    "%.*s", slen, s);
689 		} else {
690 			/* strip leading spaces/zeros */
691 			while (ksh_isspace(*s))
692 				s++;
693 			if (vp->flag & ZEROFIL)
694 				while (*s == '0')
695 					s++;
696 			shf_snprintf(p, nlen + 1, "%-*.*s",
697 				vp->u2.field, vp->u2.field, s);
698 		}
699 	} else
700 		memcpy(p, s, strlen(s) + 1);
701 
702 	if (vp->flag & UCASEV_AL) {
703 		for (q = p; *q; q++)
704 			*q = ksh_toupper(*q);
705 	} else if (vp->flag & LCASEV) {
706 		for (q = p; *q; q++)
707 			*q = ksh_tolower(*q);
708 	}
709 
710 	return (p);
711 }
712 
713 /*
714  * make vp->val.s be "name=value" for quick exporting.
715  */
716 static void
exportprep(struct tbl * vp,const char * val)717 exportprep(struct tbl *vp, const char *val)
718 {
719 	char *xp;
720 	char *op = (vp->flag&ALLOC) ? vp->val.s : NULL;
721 	size_t namelen, vallen;
722 
723 	namelen = strlen(vp->name);
724 	vallen = strlen(val) + 1;
725 
726 	vp->flag |= ALLOC;
727 	/* since name+val are both in memory this can go unchecked */
728 	xp = alloc(namelen + 1 + vallen, vp->areap);
729 	memcpy(vp->val.s = xp, vp->name, namelen);
730 	xp += namelen;
731 	*xp++ = '=';
732 	/* offset to value */
733 	vp->type = xp - vp->val.s;
734 	memcpy(xp, val, vallen);
735 	afree(op, vp->areap);
736 }
737 
738 /*
739  * lookup variable (according to (set&LOCAL)), set its attributes
740  * (INTEGER, RDONLY, EXPORT, TRACE, LJUST, RJUST, ZEROFIL, LCASEV,
741  * UCASEV_AL), and optionally set its value if an assignment.
742  */
743 struct tbl *
typeset(const char * var,uint32_t set,uint32_t clr,int field,int base)744 typeset(const char *var, uint32_t set, uint32_t clr, int field, int base)
745 {
746 	struct tbl *vp;
747 	struct tbl *vpbase, *t;
748 	char *tvar;
749 	const char *val;
750 	size_t len;
751 	bool vappend = false;
752 	enum namerefflag new_refflag = SRF_NOP;
753 
754 	if ((set & (ARRAY | ASSOC)) == ASSOC) {
755 		new_refflag = SRF_ENABLE;
756 		set &= ~(ARRAY | ASSOC);
757 	}
758 	if ((clr & (ARRAY | ASSOC)) == ASSOC) {
759 		new_refflag = SRF_DISABLE;
760 		clr &= ~(ARRAY | ASSOC);
761 	}
762 
763 	/* check for valid variable name, search for value */
764 	val = skip_varname(var, false);
765 	if (val == var) {
766 		/* no variable name given */
767 		return (NULL);
768 	}
769 	if (*val == '[') {
770 		if (new_refflag != SRF_NOP)
771 			errorf(Tf_sD_s, var,
772 			    "reference variable can't be an array");
773 		len = array_ref_len(val);
774 		if (len == 0)
775 			return (NULL);
776 		/*
777 		 * IMPORT is only used when the shell starts up and is
778 		 * setting up its environment. Allow only simple array
779 		 * references at this time since parameter/command
780 		 * substitution is performed on the [expression] which
781 		 * would be a major security hole.
782 		 */
783 		if (set & IMPORT) {
784 			size_t i;
785 
786 			for (i = 1; i < len - 1; i++)
787 				if (!ksh_isdigit(val[i]))
788 					return (NULL);
789 		}
790 		val += len;
791 	}
792 	if (val[0] == '=') {
793 		strndupx(tvar, var, val - var, ATEMP);
794 		++val;
795 	} else if (set & IMPORT) {
796 		/* environment invalid variable name or no assignment */
797 		return (NULL);
798 	} else if (val[0] == '+' && val[1] == '=') {
799 		strndupx(tvar, var, val - var, ATEMP);
800 		val += 2;
801 		vappend = true;
802 	} else if (val[0] != '\0') {
803 		/* other invalid variable names (not from environment) */
804 		return (NULL);
805 	} else {
806 		/* just varname with no value part nor equals sign */
807 		strdupx(tvar, var, ATEMP);
808 		val = NULL;
809 		/* handle foo[*] => foo (whole array) mapping for R39b */
810 		len = strlen(tvar);
811 		if (len > 3 && tvar[len - 3] == '[' && tvar[len - 2] == '*' &&
812 		    tvar[len - 1] == ']')
813 			tvar[len - 3] = '\0';
814 	}
815 
816 	if (new_refflag == SRF_ENABLE) {
817 		const char *qval, *ccp;
818 
819 		/* bail out on 'nameref foo+=bar' */
820 		if (vappend)
821 			errorf("appending not allowed for nameref");
822 		/* find value if variable already exists */
823 		if ((qval = val) == NULL) {
824 			varsearch(e->loc, &vp, tvar, hash(tvar));
825 			if (vp == NULL)
826 				goto nameref_empty;
827 			qval = str_val(vp);
828 		}
829 		/* check target value for being a valid variable name */
830 		ccp = skip_varname(qval, false);
831 		if (ccp == qval) {
832 			int c;
833 
834 			if (!(c = (unsigned char)qval[0]))
835 				goto nameref_empty;
836 			else if (ksh_isdigit(c) && getn(qval, &c))
837 				goto nameref_rhs_checked;
838 			else if (qval[1] == '\0') switch (c) {
839 			case '$':
840 			case '!':
841 			case '?':
842 			case '#':
843 			case '-':
844 				goto nameref_rhs_checked;
845 			}
846  nameref_empty:
847 			errorf(Tf_sD_s, var, "empty nameref target");
848 		}
849 		len = (*ccp == '[') ? array_ref_len(ccp) : 0;
850 		if (ccp[len]) {
851 			/*
852 			 * works for cases "no array", "valid array with
853 			 * junk after it" and "invalid array"; in the
854 			 * latter case, len is also 0 and points to '['
855 			 */
856 			errorf(Tf_sD_s, qval,
857 			    "nameref target not a valid parameter name");
858 		}
859  nameref_rhs_checked:
860 		/* prevent nameref loops */
861 		while (qval) {
862 			if (!strcmp(qval, tvar))
863 				errorf(Tf_sD_s, qval,
864 				    "expression recurses on parameter");
865 			varsearch(e->loc, &vp, qval, hash(qval));
866 			qval = NULL;
867 			if (vp && ((vp->flag & (ARRAY | ASSOC)) == ASSOC))
868 				qval = str_val(vp);
869 		}
870 	}
871 
872 	/* prevent typeset from creating a local PATH/ENV/SHELL */
873 	if (Flag(FRESTRICTED) && (strcmp(tvar, TPATH) == 0 ||
874 	    strcmp(tvar, "ENV") == 0 || strcmp(tvar, TSHELL) == 0))
875 		errorf(Tf_sD_s, tvar, "restricted");
876 
877 	innermost_refflag = new_refflag;
878 	vp = (set & LOCAL) ? local(tvar, tobool(set & LOCAL_COPY)) :
879 	    global(tvar);
880 	if (new_refflag == SRF_DISABLE && (vp->flag & (ARRAY|ASSOC)) == ASSOC)
881 		vp->flag &= ~ASSOC;
882 	else if (new_refflag == SRF_ENABLE) {
883 		if (vp->flag & ARRAY) {
884 			struct tbl *a, *tmp;
885 
886 			/* free up entire array */
887 			for (a = vp->u.array; a; ) {
888 				tmp = a;
889 				a = a->u.array;
890 				if (tmp->flag & ALLOC)
891 					afree(tmp->val.s, tmp->areap);
892 				afree(tmp, tmp->areap);
893 			}
894 			vp->u.array = NULL;
895 			vp->flag &= ~ARRAY;
896 		}
897 		vp->flag |= ASSOC;
898 	}
899 
900 	set &= ~(LOCAL|LOCAL_COPY);
901 
902 	vpbase = (vp->flag & ARRAY) ? global(arrayname(tvar)) : vp;
903 
904 	/*
905 	 * only allow export flag to be set; AT&T ksh allows any
906 	 * attribute to be changed which means it can be truncated or
907 	 * modified (-L/-R/-Z/-i)
908 	 */
909 	if ((vpbase->flag & RDONLY) &&
910 	    (val || clr || (set & ~EXPORT)))
911 		/* XXX check calls - is error here ok by POSIX? */
912 		errorfx(2, Tf_ro, tvar);
913 	afree(tvar, ATEMP);
914 
915 	/* most calls are with set/clr == 0 */
916 	if (set | clr) {
917 		bool ok = true;
918 
919 		/*
920 		 * XXX if x[0] isn't set, there will be problems: need
921 		 * to have one copy of attributes for arrays...
922 		 */
923 		for (t = vpbase; t; t = t->u.array) {
924 			bool fake_assign;
925 			char *s = NULL;
926 			char *free_me = NULL;
927 
928 			fake_assign = (t->flag & ISSET) && (!val || t != vp) &&
929 			    ((set & (UCASEV_AL|LCASEV|LJUST|RJUST|ZEROFIL)) ||
930 			    ((t->flag & INTEGER) && (clr & INTEGER)) ||
931 			    (!(t->flag & INTEGER) && (set & INTEGER)));
932 			if (fake_assign) {
933 				if (t->flag & INTEGER) {
934 					s = str_val(t);
935 					free_me = NULL;
936 				} else {
937 					s = t->val.s + t->type;
938 					free_me = (t->flag & ALLOC) ? t->val.s :
939 					    NULL;
940 				}
941 				t->flag &= ~ALLOC;
942 			}
943 			if (!(t->flag & INTEGER) && (set & INTEGER)) {
944 				t->type = 0;
945 				t->flag &= ~ALLOC;
946 			}
947 			t->flag = (t->flag | set) & ~clr;
948 			/*
949 			 * Don't change base if assignment is to be
950 			 * done, in case assignment fails.
951 			 */
952 			if ((set & INTEGER) && base > 0 && (!val || t != vp))
953 				t->type = base;
954 			if (set & (LJUST|RJUST|ZEROFIL))
955 				t->u2.field = field;
956 			if (fake_assign) {
957 				if (!setstr(t, s, KSH_RETURN_ERROR)) {
958 					/*
959 					 * Somewhat arbitrary action
960 					 * here: zap contents of
961 					 * variable, but keep the flag
962 					 * settings.
963 					 */
964 					ok = false;
965 					if (t->flag & INTEGER)
966 						t->flag &= ~ISSET;
967 					else {
968 						if (t->flag & ALLOC)
969 							afree(t->val.s, t->areap);
970 						t->flag &= ~(ISSET|ALLOC);
971 						t->type = 0;
972 					}
973 				}
974 				afree(free_me, t->areap);
975 			}
976 		}
977 		if (!ok)
978 			errorfz();
979 	}
980 
981 	if (val != NULL) {
982 		char *tval;
983 
984 		if (vappend) {
985 			tval = shf_smprintf(Tf_ss, str_val(vp), val);
986 			val = tval;
987 		} else
988 			tval = NULL;
989 
990 		if (vp->flag&INTEGER) {
991 			/* do not zero base before assignment */
992 			setstr(vp, val, KSH_UNWIND_ERROR | 0x4);
993 			/* done after assignment to override default */
994 			if (base > 0)
995 				vp->type = base;
996 		} else
997 			/* setstr can't fail (readonly check already done) */
998 			setstr(vp, val, KSH_RETURN_ERROR | 0x4);
999 
1000 		afree(tval, ATEMP);
1001 	}
1002 
1003 	/* only x[0] is ever exported, so use vpbase */
1004 	if ((vpbase->flag&EXPORT) && !(vpbase->flag&INTEGER) &&
1005 	    vpbase->type == 0)
1006 		exportprep(vpbase, (vpbase->flag&ISSET) ? vpbase->val.s : null);
1007 
1008 	return (vp);
1009 }
1010 
1011 /**
1012  * Unset a variable. The flags can be:
1013  * |1	= tear down entire array
1014  * |2	= keep attributes, only unset content
1015  */
1016 void
unset(struct tbl * vp,int flags)1017 unset(struct tbl *vp, int flags)
1018 {
1019 	if (vp->flag & ALLOC)
1020 		afree(vp->val.s, vp->areap);
1021 	if ((vp->flag & ARRAY) && (flags & 1)) {
1022 		struct tbl *a, *tmp;
1023 
1024 		/* free up entire array */
1025 		for (a = vp->u.array; a; ) {
1026 			tmp = a;
1027 			a = a->u.array;
1028 			if (tmp->flag & ALLOC)
1029 				afree(tmp->val.s, tmp->areap);
1030 			afree(tmp, tmp->areap);
1031 		}
1032 		vp->u.array = NULL;
1033 	}
1034 	if (flags & 2) {
1035 		vp->flag &= ~(ALLOC|ISSET);
1036 		return;
1037 	}
1038 	/* if foo[0] is being unset, the remainder of the array is kept... */
1039 	vp->flag &= SPECIAL | ((flags & 1) ? 0 : ARRAY|DEFINED);
1040 	if (vp->flag & SPECIAL)
1041 		/* responsible for 'unspecial'ing var */
1042 		unsetspec(vp);
1043 }
1044 
1045 /*
1046  * Return a pointer to the first char past a legal variable name
1047  * (returns the argument if there is no legal name, returns a pointer to
1048  * the terminating NUL if whole string is legal).
1049  */
1050 const char *
skip_varname(const char * s,bool aok)1051 skip_varname(const char *s, bool aok)
1052 {
1053 	size_t alen;
1054 
1055 	if (s && ksh_isalphx(*s)) {
1056 		while (*++s && ksh_isalnux(*s))
1057 			;
1058 		if (aok && *s == '[' && (alen = array_ref_len(s)))
1059 			s += alen;
1060 	}
1061 	return (s);
1062 }
1063 
1064 /* Return a pointer to the first character past any legal variable name */
1065 const char *
skip_wdvarname(const char * s,bool aok)1066 skip_wdvarname(const char *s,
1067     /* skip array de-reference? */
1068     bool aok)
1069 {
1070 	if (s[0] == CHAR && ksh_isalphx(s[1])) {
1071 		do {
1072 			s += 2;
1073 		} while (s[0] == CHAR && ksh_isalnux(s[1]));
1074 		if (aok && s[0] == CHAR && s[1] == '[') {
1075 			/* skip possible array de-reference */
1076 			const char *p = s;
1077 			char c;
1078 			int depth = 0;
1079 
1080 			while (/* CONSTCOND */ 1) {
1081 				if (p[0] != CHAR)
1082 					break;
1083 				c = p[1];
1084 				p += 2;
1085 				if (c == '[')
1086 					depth++;
1087 				else if (c == ']' && --depth == 0) {
1088 					s = p;
1089 					break;
1090 				}
1091 			}
1092 		}
1093 	}
1094 	return (s);
1095 }
1096 
1097 /* Check if coded string s is a variable name */
1098 int
is_wdvarname(const char * s,bool aok)1099 is_wdvarname(const char *s, bool aok)
1100 {
1101 	const char *p = skip_wdvarname(s, aok);
1102 
1103 	return (p != s && p[0] == EOS);
1104 }
1105 
1106 /* Check if coded string s is a variable assignment */
1107 int
is_wdvarassign(const char * s)1108 is_wdvarassign(const char *s)
1109 {
1110 	const char *p = skip_wdvarname(s, true);
1111 
1112 	return (p != s && p[0] == CHAR &&
1113 	    (p[1] == '=' || (p[1] == '+' && p[2] == CHAR && p[3] == '=')));
1114 }
1115 
1116 /*
1117  * Make the exported environment from the exported names in the dictionary.
1118  */
1119 char **
makenv(void)1120 makenv(void)
1121 {
1122 	ssize_t i;
1123 	struct block *l;
1124 	XPtrV denv;
1125 	struct tbl *vp, **vpp;
1126 
1127 	XPinit(denv, 64);
1128 	for (l = e->loc; l != NULL; l = l->next) {
1129 		vpp = l->vars.tbls;
1130 		i = 1 << (l->vars.tshift);
1131 		while (--i >= 0)
1132 			if ((vp = *vpp++) != NULL &&
1133 			    (vp->flag&(ISSET|EXPORT)) == (ISSET|EXPORT)) {
1134 				struct block *l2;
1135 				struct tbl *vp2;
1136 				uint32_t h = hash(vp->name);
1137 
1138 				/* unexport any redefined instances */
1139 				for (l2 = l->next; l2 != NULL; l2 = l2->next) {
1140 					vp2 = ktsearch(&l2->vars, vp->name, h);
1141 					if (vp2 != NULL)
1142 						vp2->flag &= ~EXPORT;
1143 				}
1144 				if ((vp->flag&INTEGER)) {
1145 					/* integer to string */
1146 					char *val;
1147 					val = str_val(vp);
1148 					vp->flag &= ~(INTEGER|RDONLY|SPECIAL);
1149 					/* setstr can't fail here */
1150 					setstr(vp, val, KSH_RETURN_ERROR);
1151 				}
1152 #ifdef __OS2__
1153 				/* these special variables are not exported */
1154 				if (!strcmp(vp->name, "BEGINLIBPATH") ||
1155 				    !strcmp(vp->name, "ENDLIBPATH") ||
1156 				    !strcmp(vp->name, "LIBPATHSTRICT"))
1157 					continue;
1158 #endif
1159 				XPput(denv, vp->val.s);
1160 			}
1161 		if (l->flags & BF_STOPENV)
1162 			break;
1163 	}
1164 	XPput(denv, NULL);
1165 	return ((char **)XPclose(denv));
1166 }
1167 
1168 /*
1169  * handle special variables with side effects - PATH, SECONDS.
1170  */
1171 
1172 /* Test if name is a special parameter */
1173 static int
special(const char * name)1174 special(const char *name)
1175 {
1176 	struct tbl *tp;
1177 
1178 	tp = ktsearch(&specials, name, hash(name));
1179 	return (tp && (tp->flag & ISSET) ? tp->type : V_NONE);
1180 }
1181 
1182 /* Make a variable non-special */
1183 static void
unspecial(const char * name)1184 unspecial(const char *name)
1185 {
1186 	struct tbl *tp;
1187 
1188 	tp = ktsearch(&specials, name, hash(name));
1189 	if (tp)
1190 		ktdelete(tp);
1191 }
1192 
1193 static time_t seconds;		/* time SECONDS last set */
1194 static mksh_uari_t user_lineno;	/* what user set $LINENO to */
1195 
1196 /* minimum values from the OS we consider sane, lowered for R53 */
1197 #define MIN_COLS	4
1198 #define MIN_LINS	2
1199 
1200 static void
getspec(struct tbl * vp)1201 getspec(struct tbl *vp)
1202 {
1203 	mksh_ari_u num;
1204 	int st;
1205 	struct timeval tv;
1206 
1207 	switch ((st = special(vp->name))) {
1208 	case V_COLUMNS:
1209 	case V_LINES:
1210 		/*
1211 		 * Do NOT export COLUMNS/LINES. Many applications
1212 		 * check COLUMNS/LINES before checking ws.ws_col/row,
1213 		 * so if the app is started with C/L in the environ
1214 		 * and the window is then resized, the app won't
1215 		 * see the change cause the environ doesn't change.
1216 		 */
1217 		if (got_winch)
1218 			change_winsz();
1219 		break;
1220 	}
1221 	switch (st) {
1222 	case V_BASHPID:
1223 		num.u = (mksh_uari_t)procpid;
1224 		break;
1225 	case V_COLUMNS:
1226 		num.i = x_cols;
1227 		break;
1228 	case V_HISTSIZE:
1229 		num.i = histsize;
1230 		break;
1231 	case V_LINENO:
1232 		num.u = (mksh_uari_t)current_lineno + user_lineno;
1233 		break;
1234 	case V_LINES:
1235 		num.i = x_lins;
1236 		break;
1237 	case V_EPOCHREALTIME: {
1238 		/* 10(%u) + 1(.) + 6 + NUL */
1239 		char buf[18];
1240 
1241 		vp->flag &= ~SPECIAL;
1242 		mksh_TIME(tv);
1243 		shf_snprintf(buf, sizeof(buf), "%u.%06u",
1244 		    (unsigned)tv.tv_sec, (unsigned)tv.tv_usec);
1245 		setstr(vp, buf, KSH_RETURN_ERROR | 0x4);
1246 		vp->flag |= SPECIAL;
1247 		return;
1248 	}
1249 	case V_OPTIND:
1250 		num.i = user_opt.uoptind;
1251 		break;
1252 	case V_RANDOM:
1253 		num.i = rndget();
1254 		break;
1255 	case V_SECONDS:
1256 		/*
1257 		 * On start up the value of SECONDS is used before
1258 		 * it has been set - don't do anything in this case
1259 		 * (see initcoms[] in main.c).
1260 		 */
1261 		if (vp->flag & ISSET) {
1262 			mksh_TIME(tv);
1263 			num.i = tv.tv_sec - seconds;
1264 		} else
1265 			return;
1266 		break;
1267 	default:
1268 		/* do nothing, do not touch vp at all */
1269 		return;
1270 	}
1271 	vp->flag &= ~SPECIAL;
1272 	setint_n(vp, num.i, 0);
1273 	vp->flag |= SPECIAL;
1274 }
1275 
1276 static void
setspec(struct tbl * vp)1277 setspec(struct tbl *vp)
1278 {
1279 	mksh_ari_u num;
1280 	char *s;
1281 	int st;
1282 
1283 	switch ((st = special(vp->name))) {
1284 #ifdef __OS2__
1285 	case V_BEGINLIBPATH:
1286 	case V_ENDLIBPATH:
1287 	case V_LIBPATHSTRICT:
1288 		setextlibpath(vp->name, str_val(vp));
1289 		return;
1290 #endif
1291 #if HAVE_PERSISTENT_HISTORY
1292 	case V_HISTFILE:
1293 		sethistfile(str_val(vp));
1294 		return;
1295 #endif
1296 	case V_IFS:
1297 		setctypes(s = str_val(vp), C_IFS);
1298 		ifs0 = *s;
1299 		return;
1300 	case V_PATH:
1301 		afree(path, APERM);
1302 		s = str_val(vp);
1303 		strdupx(path, s, APERM);
1304 		/* clear tracked aliases */
1305 		flushcom(true);
1306 		return;
1307 #ifndef MKSH_NO_CMDLINE_EDITING
1308 	case V_TERM:
1309 		x_initterm(str_val(vp));
1310 		return;
1311 #endif
1312 	case V_TMPDIR:
1313 		afree(tmpdir, APERM);
1314 		tmpdir = NULL;
1315 		/*
1316 		 * Use tmpdir iff it is an absolute path, is writable
1317 		 * and searchable and is a directory...
1318 		 */
1319 		{
1320 			struct stat statb;
1321 
1322 			s = str_val(vp);
1323 			/* LINTED use of access */
1324 			if (mksh_abspath(s) && access(s, W_OK|X_OK) == 0 &&
1325 			    stat(s, &statb) == 0 && S_ISDIR(statb.st_mode))
1326 				strdupx(tmpdir, s, APERM);
1327 		}
1328 		return;
1329 	/* common sub-cases */
1330 	case V_COLUMNS:
1331 	case V_LINES:
1332 		if (vp->flag & IMPORT) {
1333 			/* do not touch */
1334 			unspecial(vp->name);
1335 			vp->flag &= ~SPECIAL;
1336 			return;
1337 		}
1338 		/* FALLTHROUGH */
1339 	case V_HISTSIZE:
1340 	case V_LINENO:
1341 	case V_OPTIND:
1342 	case V_RANDOM:
1343 	case V_SECONDS:
1344 	case V_TMOUT:
1345 		vp->flag &= ~SPECIAL;
1346 		if (getint(vp, &num, false) == -1) {
1347 			s = str_val(vp);
1348 			if (st != V_RANDOM)
1349 				errorf(Tf_sD_sD_s, vp->name, "bad number", s);
1350 			num.u = hash(s);
1351 		}
1352 		vp->flag |= SPECIAL;
1353 		break;
1354 	default:
1355 		/* do nothing, do not touch vp at all */
1356 		return;
1357 	}
1358 
1359 	/* process the singular parts of the common cases */
1360 
1361 	switch (st) {
1362 	case V_COLUMNS:
1363 		if (num.i >= MIN_COLS)
1364 			x_cols = num.i;
1365 		break;
1366 	case V_HISTSIZE:
1367 		sethistsize(num.i);
1368 		break;
1369 	case V_LINENO:
1370 		/* The -1 is because line numbering starts at 1. */
1371 		user_lineno = num.u - (mksh_uari_t)current_lineno - 1;
1372 		break;
1373 	case V_LINES:
1374 		if (num.i >= MIN_LINS)
1375 			x_lins = num.i;
1376 		break;
1377 	case V_OPTIND:
1378 		getopts_reset((int)num.i);
1379 		break;
1380 	case V_RANDOM:
1381 		/*
1382 		 * mksh R39d+ no longer has the traditional repeatability
1383 		 * of $RANDOM sequences, but always retains state
1384 		 */
1385 		rndset((unsigned long)num.u);
1386 		break;
1387 	case V_SECONDS:
1388 		{
1389 			struct timeval tv;
1390 
1391 			mksh_TIME(tv);
1392 			seconds = tv.tv_sec - num.i;
1393 		}
1394 		break;
1395 	case V_TMOUT:
1396 		ksh_tmout = num.i >= 0 ? num.i : 0;
1397 		break;
1398 	}
1399 }
1400 
1401 static void
unsetspec(struct tbl * vp)1402 unsetspec(struct tbl *vp)
1403 {
1404 	/*
1405 	 * AT&T ksh man page says OPTIND, OPTARG and _ lose special
1406 	 * meaning, but OPTARG does not (still set by getopts) and _ is
1407 	 * also still set in various places. Don't know what AT&T does
1408 	 * for HISTSIZE, HISTFILE. Unsetting these in AT&T ksh does not
1409 	 * loose the 'specialness': IFS, COLUMNS, PATH, TMPDIR
1410 	 */
1411 
1412 	switch (special(vp->name)) {
1413 #ifdef __OS2__
1414 	case V_BEGINLIBPATH:
1415 	case V_ENDLIBPATH:
1416 	case V_LIBPATHSTRICT:
1417 		setextlibpath(vp->name, "");
1418 		return;
1419 #endif
1420 #if HAVE_PERSISTENT_HISTORY
1421 	case V_HISTFILE:
1422 		sethistfile(NULL);
1423 		return;
1424 #endif
1425 	case V_IFS:
1426 		setctypes(TC_IFSWS, C_IFS);
1427 		ifs0 = ' ';
1428 		break;
1429 	case V_PATH:
1430 		afree(path, APERM);
1431 		strdupx(path, def_path, APERM);
1432 		/* clear tracked aliases */
1433 		flushcom(true);
1434 		break;
1435 #ifndef MKSH_NO_CMDLINE_EDITING
1436 	case V_TERM:
1437 		x_initterm(null);
1438 		return;
1439 #endif
1440 	case V_TMPDIR:
1441 		/* should not become unspecial */
1442 		if (tmpdir) {
1443 			afree(tmpdir, APERM);
1444 			tmpdir = NULL;
1445 		}
1446 		break;
1447 	case V_LINENO:
1448 	case V_RANDOM:
1449 	case V_SECONDS:
1450 	case V_TMOUT:
1451 		/* AT&T ksh leaves previous value in place */
1452 		unspecial(vp->name);
1453 		break;
1454 	}
1455 }
1456 
1457 /*
1458  * Search for (and possibly create) a table entry starting with
1459  * vp, indexed by val.
1460  */
1461 struct tbl *
arraysearch(struct tbl * vp,uint32_t val)1462 arraysearch(struct tbl *vp, uint32_t val)
1463 {
1464 	struct tbl *prev, *curr, *news;
1465 	size_t len;
1466 
1467 	vp->flag = (vp->flag | (ARRAY | DEFINED)) & ~ASSOC;
1468 	/* the table entry is always [0] */
1469 	if (val == 0)
1470 		return (vp);
1471 	prev = vp;
1472 	curr = vp->u.array;
1473 	while (curr && curr->ua.index < val) {
1474 		prev = curr;
1475 		curr = curr->u.array;
1476 	}
1477 	if (curr && curr->ua.index == val) {
1478 		if (curr->flag&ISSET)
1479 			return (curr);
1480 		news = curr;
1481 	} else
1482 		news = NULL;
1483 	if (!news) {
1484 		len = strlen(vp->name);
1485 		checkoktoadd(len, 1 + offsetof(struct tbl, name[0]));
1486 		news = alloc(offsetof(struct tbl, name[0]) + ++len, vp->areap);
1487 		memcpy(news->name, vp->name, len);
1488 	}
1489 	news->flag = (vp->flag & ~(ALLOC|DEFINED|ISSET|SPECIAL)) | AINDEX;
1490 	news->type = vp->type;
1491 	news->areap = vp->areap;
1492 	news->u2.field = vp->u2.field;
1493 	news->ua.index = val;
1494 
1495 	if (curr != news) {
1496 		/* not reusing old array entry */
1497 		prev->u.array = news;
1498 		news->u.array = curr;
1499 	}
1500 	return (news);
1501 }
1502 
1503 /*
1504  * Return the length of an array reference (eg, [1+2]) - cp is assumed
1505  * to point to the open bracket. Returns 0 if there is no matching
1506  * closing bracket.
1507  *
1508  * XXX this should parse the actual arithmetic syntax
1509  */
1510 size_t
array_ref_len(const char * cp)1511 array_ref_len(const char *cp)
1512 {
1513 	const char *s = cp;
1514 	char c;
1515 	int depth = 0;
1516 
1517 	while ((c = *s++) && (c != ']' || --depth))
1518 		if (c == '[')
1519 			depth++;
1520 	if (!c)
1521 		return (0);
1522 	return (s - cp);
1523 }
1524 
1525 /*
1526  * Make a copy of the base of an array name
1527  */
1528 char *
arrayname(const char * str)1529 arrayname(const char *str)
1530 {
1531 	const char *p;
1532 	char *rv;
1533 
1534 	if (!(p = cstrchr(str, '[')))
1535 		/* Shouldn't happen, but why worry? */
1536 		strdupx(rv, str, ATEMP);
1537 	else
1538 		strndupx(rv, str, p - str, ATEMP);
1539 
1540 	return (rv);
1541 }
1542 
1543 /* set (or overwrite, if reset) the array variable var to the values in vals */
1544 mksh_uari_t
set_array(const char * var,bool reset,const char ** vals)1545 set_array(const char *var, bool reset, const char **vals)
1546 {
1547 	struct tbl *vp, *vq;
1548 	mksh_uari_t i = 0, j = 0;
1549 	const char *ccp = var;
1550 	char *cp = NULL;
1551 	size_t n;
1552 
1553 	/* to get local array, use "local foo; set -A foo" */
1554 	n = strlen(var);
1555 	if (n > 0 && var[n - 1] == '+') {
1556 		/* append mode */
1557 		reset = false;
1558 		strndupx(cp, var, n - 1, ATEMP);
1559 		ccp = cp;
1560 	}
1561 	vp = global(ccp);
1562 
1563 	/* Note: AT&T ksh allows set -A but not set +A of a read-only var */
1564 	if ((vp->flag&RDONLY))
1565 		errorfx(2, Tf_ro, ccp);
1566 	/* This code is quite non-optimal */
1567 	if (reset) {
1568 		/* trash existing values and attributes */
1569 		unset(vp, 1);
1570 		/* allocate-by-access the [0] element to keep in scope */
1571 		arraysearch(vp, 0);
1572 	}
1573 	/*
1574 	 * TODO: would be nice for assignment to completely succeed or
1575 	 * completely fail. Only really effects integer arrays:
1576 	 * evaluation of some of vals[] may fail...
1577 	 */
1578 	if (cp != NULL) {
1579 		/* find out where to set when appending */
1580 		for (vq = vp; vq; vq = vq->u.array) {
1581 			if (!(vq->flag & ISSET))
1582 				continue;
1583 			if (arrayindex(vq) >= j)
1584 				j = arrayindex(vq) + 1;
1585 		}
1586 		afree(cp, ATEMP);
1587 	}
1588 	while ((ccp = vals[i])) {
1589 #if 0 /* temporarily taken out due to regression */
1590 		if (*ccp == '[') {
1591 			int level = 0;
1592 
1593 			while (*ccp) {
1594 				if (*ccp == ']' && --level == 0)
1595 					break;
1596 				if (*ccp == '[')
1597 					++level;
1598 				++ccp;
1599 			}
1600 			if (*ccp == ']' && level == 0 && ccp[1] == '=') {
1601 				strndupx(cp, vals[i] + 1, ccp - (vals[i] + 1),
1602 				    ATEMP);
1603 				evaluate(substitute(cp, 0), (mksh_ari_t *)&j,
1604 				    KSH_UNWIND_ERROR, true);
1605 				afree(cp, ATEMP);
1606 				ccp += 2;
1607 			} else
1608 				ccp = vals[i];
1609 		}
1610 #endif
1611 
1612 		vq = arraysearch(vp, j);
1613 		/* would be nice to deal with errors here... (see above) */
1614 		setstr(vq, ccp, KSH_RETURN_ERROR);
1615 		i++;
1616 		j++;
1617 	}
1618 
1619 	return (i);
1620 }
1621 
1622 void
change_winsz(void)1623 change_winsz(void)
1624 {
1625 	struct timeval tv;
1626 
1627 	mksh_TIME(tv);
1628 	BAFHUpdateMem_mem(qh_state, &tv, sizeof(tv));
1629 
1630 #ifdef TIOCGWINSZ
1631 	/* check if window size has changed */
1632 	if (tty_init_fd() < 2) {
1633 		struct winsize ws;
1634 
1635 		if (ioctl(tty_fd, TIOCGWINSZ, &ws) >= 0) {
1636 			if (ws.ws_col)
1637 				x_cols = ws.ws_col;
1638 			if (ws.ws_row)
1639 				x_lins = ws.ws_row;
1640 		}
1641 	}
1642 #endif
1643 
1644 	/* bounds check for sane values, use defaults otherwise */
1645 	if (x_cols < MIN_COLS)
1646 		x_cols = 80;
1647 	if (x_lins < MIN_LINS)
1648 		x_lins = 24;
1649 
1650 #ifdef SIGWINCH
1651 	got_winch = 0;
1652 #endif
1653 }
1654 
1655 uint32_t
hash(const void * s)1656 hash(const void *s)
1657 {
1658 	register uint32_t h;
1659 
1660 	BAFHInit(h);
1661 	BAFHUpdateStr_reg(h, s);
1662 	BAFHFinish_reg(h);
1663 	return (h);
1664 }
1665 
1666 uint32_t
chvt_rndsetup(const void * bp,size_t sz)1667 chvt_rndsetup(const void *bp, size_t sz)
1668 {
1669 	register uint32_t h;
1670 
1671 	/* use LCG as seed but try to get them to deviate immediately */
1672 	h = lcg_state;
1673 	(void)rndget();
1674 	BAFHFinish_reg(h);
1675 	/* variation through pid, ppid, and the works */
1676 	BAFHUpdateMem_reg(h, &rndsetupstate, sizeof(rndsetupstate));
1677 	/* some variation, some possibly entropy, depending on OE */
1678 	BAFHUpdateMem_reg(h, bp, sz);
1679 	/* mix them all up */
1680 	BAFHFinish_reg(h);
1681 
1682 	return (h);
1683 }
1684 
1685 mksh_ari_t
rndget(void)1686 rndget(void)
1687 {
1688 	/*
1689 	 * this is the same Linear Congruential PRNG as Borland
1690 	 * C/C++ allegedly uses in its built-in rand() function
1691 	 */
1692 	return (((lcg_state = 22695477 * lcg_state + 1) >> 16) & 0x7FFF);
1693 }
1694 
1695 void
rndset(unsigned long v)1696 rndset(unsigned long v)
1697 {
1698 	register uint32_t h;
1699 #if defined(arc4random_pushb_fast) || defined(MKSH_A4PB)
1700 	register uint32_t t;
1701 #endif
1702 	struct {
1703 		struct timeval tv;
1704 		void *sp;
1705 		uint32_t qh;
1706 		pid_t pp;
1707 		short r;
1708 	} z;
1709 
1710 	/* clear the allocated space, for valgrind and to avoid UB */
1711 	memset(&z, 0, sizeof(z));
1712 
1713 	h = lcg_state;
1714 	BAFHFinish_reg(h);
1715 	BAFHUpdateMem_reg(h, &v, sizeof(v));
1716 
1717 	mksh_TIME(z.tv);
1718 	z.sp = &lcg_state;
1719 	z.pp = procpid;
1720 	z.r = (short)rndget();
1721 
1722 #if defined(arc4random_pushb_fast) || defined(MKSH_A4PB)
1723 	t = qh_state;
1724 	BAFHFinish_reg(t);
1725 	z.qh = (t & 0xFFFF8000) | rndget();
1726 	lcg_state = (t << 15) | rndget();
1727 	/*
1728 	 * either we have very chap entropy get and push available,
1729 	 * with malloc() pulling in this code already anyway, or the
1730 	 * user requested us to use the old functions
1731 	 */
1732 	t = h;
1733 	BAFHUpdateMem_reg(t, &lcg_state, sizeof(lcg_state));
1734 	BAFHFinish_reg(t);
1735 	lcg_state = t;
1736 #if defined(arc4random_pushb_fast)
1737 	arc4random_pushb_fast(&lcg_state, sizeof(lcg_state));
1738 	lcg_state = arc4random();
1739 #else
1740 	lcg_state = arc4random_pushb(&lcg_state, sizeof(lcg_state));
1741 #endif
1742 	BAFHUpdateMem_reg(h, &lcg_state, sizeof(lcg_state));
1743 #else
1744 	z.qh = qh_state;
1745 #endif
1746 
1747 	BAFHUpdateMem_reg(h, &z, sizeof(z));
1748 	BAFHFinish_reg(h);
1749 	lcg_state = h;
1750 }
1751 
1752 void
rndpush(const void * s)1753 rndpush(const void *s)
1754 {
1755 	register uint32_t h = qh_state;
1756 
1757 	BAFHUpdateStr_reg(h, s);
1758 	BAFHUpdateOctet_reg(h, 0);
1759 	qh_state = h;
1760 }
1761 
1762 /* record last glob match */
1763 void
record_match(const char * istr)1764 record_match(const char *istr)
1765 {
1766 	struct tbl *vp;
1767 
1768 	vp = local("KSH_MATCH", false);
1769 	unset(vp, 1);
1770 	vp->flag = DEFINED | RDONLY;
1771 	setstr(vp, istr, 0x4);
1772 }
1773