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