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mksh/var.c
tg be147e3426 SECURITY: make “unset HISTFILE” really work 
additionally, make “HISTFILE=” the same, document the truncation and
re-reading process’ further and already-known bugs; this needs work
2015-03-07 20:46:31 +00:00

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/* $OpenBSD: var.c,v 1.40 2014/12/12 05:00:55 jsg Exp $ */
/*-
* Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
* 2011, 2012, 2013, 2014, 2015
* Thorsten Glaser <tg@mirbsd.org>
*
* Provided that these terms and disclaimer and all copyright notices
* are retained or reproduced in an accompanying document, permission
* is granted to deal in this work without restriction, including un-
* limited rights to use, publicly perform, distribute, sell, modify,
* merge, give away, or sublicence.
*
* This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
* the utmost extent permitted by applicable law, neither express nor
* implied; without malicious intent or gross negligence. In no event
* may a licensor, author or contributor be held liable for indirect,
* direct, other damage, loss, or other issues arising in any way out
* of dealing in the work, even if advised of the possibility of such
* damage or existence of a defect, except proven that it results out
* of said person's immediate fault when using the work as intended.
*/
#include "sh.h"
#include "mirhash.h"
#if defined(__OpenBSD__)
#include <sys/sysctl.h>
#endif
__RCSID("$MirOS: src/bin/mksh/var.c,v 1.187 2015/03/07 20:46:31 tg Exp $");
/*-
* Variables
*
* WARNING: unreadable code, needs a rewrite
*
* if (flag&INTEGER), val.i contains integer value, and type contains base.
* otherwise, (val.s + type) contains string value.
* if (flag&EXPORT), val.s contains "name=value" for E-Z exporting.
*/
static struct table specials;
static uint32_t lcg_state = 5381, qh_state = 4711;
/* may only be set by typeset() just before call to array_index_calc() */
static enum namerefflag innermost_refflag = SRF_NOP;
static char *formatstr(struct tbl *, const char *);
static void exportprep(struct tbl *, const char *);
static int special(const char *);
static void unspecial(const char *);
static void getspec(struct tbl *);
static void setspec(struct tbl *);
static void unsetspec(struct tbl *);
static int getint(struct tbl *, mksh_ari_u *, bool);
static const char *array_index_calc(const char *, bool *, uint32_t *);
/*
* create a new block for function calls and simple commands
* assume caller has allocated and set up e->loc
*/
void
newblock(void)
{
struct block *l;
static const char *empty[] = { null };
l = alloc(sizeof(struct block), ATEMP);
l->flags = 0;
/* TODO: could use e->area (l->area => l->areap) */
ainit(&l->area);
if (!e->loc) {
l->argc = 0;
l->argv = empty;
} else {
l->argc = e->loc->argc;
l->argv = e->loc->argv;
}
l->exit = l->error = NULL;
ktinit(&l->area, &l->vars, 0);
ktinit(&l->area, &l->funs, 0);
l->next = e->loc;
e->loc = l;
}
/*
* pop a block handling special variables
*/
void
popblock(void)
{
ssize_t i;
struct block *l = e->loc;
struct tbl *vp, **vpp = l->vars.tbls, *vq;
/* pop block */
e->loc = l->next;
i = 1 << (l->vars.tshift);
while (--i >= 0)
if ((vp = *vpp++) != NULL && (vp->flag&SPECIAL)) {
if ((vq = global(vp->name))->flag & ISSET)
setspec(vq);
else
unsetspec(vq);
}
if (l->flags & BF_DOGETOPTS)
user_opt = l->getopts_state;
afreeall(&l->area);
afree(l, ATEMP);
}
/* called by main() to initialise variable data structures */
#define VARSPEC_DEFNS
#include "var_spec.h"
enum var_specs {
#define VARSPEC_ENUMS
#include "var_spec.h"
V_MAX
};
/* this is biased with -1 relative to VARSPEC_ENUMS */
static const char * const initvar_names[] = {
#define VARSPEC_ITEMS
#include "var_spec.h"
};
void
initvar(void)
{
int i = 0;
struct tbl *tp;
ktinit(APERM, &specials,
/* currently 14 specials: 75% of 32 = 2^5 */
5);
while (i < V_MAX - 1) {
tp = ktenter(&specials, initvar_names[i],
hash(initvar_names[i]));
tp->flag = DEFINED|ISSET;
tp->type = ++i;
}
}
/* common code for several functions below and c_typeset() */
struct block *
varsearch(struct block *l, struct tbl **vpp, const char *vn, uint32_t h)
{
register struct tbl *vp;
if (l) {
varsearch_loop:
if ((vp = ktsearch(&l->vars, vn, h)) != NULL)
goto varsearch_out;
if (l->next != NULL) {
l = l->next;
goto varsearch_loop;
}
}
vp = NULL;
varsearch_out:
*vpp = vp;
return (l);
}
/*
* Used to calculate an array index for global()/local(). Sets *arrayp
* to true if this is an array, sets *valp to the array index, returns
* the basename of the array. May only be called from global()/local()
* and must be their first callee.
*/
static const char *
array_index_calc(const char *n, bool *arrayp, uint32_t *valp)
{
const char *p;
size_t len;
char *ap = NULL;
*arrayp = false;
redo_from_ref:
p = skip_varname(n, false);
if (innermost_refflag == SRF_NOP && (p != n) && ksh_isalphx(n[0])) {
struct tbl *vp;
char *vn;
strndupx(vn, n, p - n, ATEMP);
/* check if this is a reference */
varsearch(e->loc, &vp, vn, hash(vn));
afree(vn, ATEMP);
if (vp && (vp->flag & (DEFINED | ASSOC | ARRAY)) ==
(DEFINED | ASSOC)) {
char *cp;
/* gotcha! */
cp = shf_smprintf("%s%s", str_val(vp), p);
afree(ap, ATEMP);
n = ap = cp;
goto redo_from_ref;
}
}
innermost_refflag = SRF_NOP;
if (p != n && *p == '[' && (len = array_ref_len(p))) {
char *sub, *tmp;
mksh_ari_t rval;
/* calculate the value of the subscript */
*arrayp = true;
strndupx(tmp, p + 1, len - 2, ATEMP);
sub = substitute(tmp, 0);
afree(tmp, ATEMP);
strndupx(n, n, p - n, ATEMP);
evaluate(sub, &rval, KSH_UNWIND_ERROR, true);
*valp = (uint32_t)rval;
afree(sub, ATEMP);
}
return (n);
}
/*
* Search for variable, if not found create globally.
*/
struct tbl *
global(const char *n)
{
struct block *l = e->loc;
struct tbl *vp;
int c;
bool array;
uint32_t h, val;
/*
* check to see if this is an array;
* dereference namerefs; must come first
*/
n = array_index_calc(n, &array, &val);
h = hash(n);
c = (unsigned char)n[0];
if (!ksh_isalphx(c)) {
if (array)
errorf("bad substitution");
vp = &vtemp;
vp->flag = DEFINED;
vp->type = 0;
vp->areap = ATEMP;
*vp->name = c;
if (ksh_isdigit(c)) {
if (getn(n, &c) && (c <= l->argc))
/* setstr can't fail here */
setstr(vp, l->argv[c], KSH_RETURN_ERROR);
vp->flag |= RDONLY;
return (vp);
}
vp->flag |= RDONLY;
if (n[1] != '\0')
return (vp);
vp->flag |= ISSET|INTEGER;
switch (c) {
case '$':
vp->val.i = kshpid;
break;
case '!':
/* if no job, expand to nothing */
if ((vp->val.i = j_async()) == 0)
vp->flag &= ~(ISSET|INTEGER);
break;
case '?':
vp->val.i = exstat & 0xFF;
break;
case '#':
vp->val.i = l->argc;
break;
case '-':
vp->flag &= ~INTEGER;
vp->val.s = getoptions();
break;
default:
vp->flag &= ~(ISSET|INTEGER);
}
return (vp);
}
l = varsearch(e->loc, &vp, n, h);
if (vp != NULL)
return (array ? arraysearch(vp, val) : vp);
vp = ktenter(&l->vars, n, h);
if (array)
vp = arraysearch(vp, val);
vp->flag |= DEFINED;
if (special(n))
vp->flag |= SPECIAL;
return (vp);
}
/*
* Search for local variable, if not found create locally.
*/
struct tbl *
local(const char *n, bool copy)
{
struct block *l = e->loc;
struct tbl *vp;
bool array;
uint32_t h, val;
/*
* check to see if this is an array;
* dereference namerefs; must come first
*/
n = array_index_calc(n, &array, &val);
h = hash(n);
if (!ksh_isalphx(*n)) {
vp = &vtemp;
vp->flag = DEFINED|RDONLY;
vp->type = 0;
vp->areap = ATEMP;
return (vp);
}
vp = ktenter(&l->vars, n, h);
if (copy && !(vp->flag & DEFINED)) {
struct tbl *vq;
varsearch(l->next, &vq, n, h);
if (vq != NULL) {
vp->flag |= vq->flag &
(EXPORT | INTEGER | RDONLY | LJUST | RJUST |
ZEROFIL | LCASEV | UCASEV_AL | INT_U | INT_L);
if (vq->flag & INTEGER)
vp->type = vq->type;
vp->u2.field = vq->u2.field;
}
}
if (array)
vp = arraysearch(vp, val);
vp->flag |= DEFINED;
if (special(n))
vp->flag |= SPECIAL;
return (vp);
}
/* get variable string value */
char *
str_val(struct tbl *vp)
{
char *s;
if ((vp->flag&SPECIAL))
getspec(vp);
if (!(vp->flag&ISSET))
/* special to dollar() */
s = null;
else if (!(vp->flag&INTEGER))
/* string source */
s = vp->val.s + vp->type;
else {
/* integer source */
mksh_uari_t n;
unsigned int base;
/**
* worst case number length is when base == 2:
* 1 (minus) + 2 (base, up to 36) + 1 ('#') +
* number of bits in the mksh_uari_t + 1 (NUL)
*/
char strbuf[1 + 2 + 1 + 8 * sizeof(mksh_uari_t) + 1];
const char *digits = (vp->flag & UCASEV_AL) ?
digits_uc : digits_lc;
s = strbuf + sizeof(strbuf);
if (vp->flag & INT_U)
n = vp->val.u;
else
n = (vp->val.i < 0) ? -vp->val.u : vp->val.u;
base = (vp->type == 0) ? 10U : (unsigned int)vp->type;
if (base == 1 && n == 0)
base = 2;
if (base == 1) {
size_t sz = 1;
*(s = strbuf) = '1';
s[1] = '#';
if (!UTFMODE || ((n & 0xFF80) == 0xEF80))
/* OPTU-16 -> raw octet */
s[2] = n & 0xFF;
else
sz = utf_wctomb(s + 2, n);
s[2 + sz] = '\0';
} else {
*--s = '\0';
do {
*--s = digits[n % base];
n /= base;
} while (n != 0);
if (base != 10) {
*--s = '#';
*--s = digits[base % 10];
if (base >= 10)
*--s = digits[base / 10];
}
if (!(vp->flag & INT_U) && vp->val.i < 0)
*--s = '-';
}
if (vp->flag & (RJUST|LJUST))
/* case already dealt with */
s = formatstr(vp, s);
else
strdupx(s, s, ATEMP);
}
return (s);
}
/* set variable to string value */
int
setstr(struct tbl *vq, const char *s, int error_ok)
{
char *salloc = NULL;
bool no_ro_check = tobool(error_ok & 0x4);
error_ok &= ~0x4;
if ((vq->flag & RDONLY) && !no_ro_check) {
warningf(true, "read-only: %s", vq->name);
if (!error_ok)
errorfxz(2);
return (0);
}
if (!(vq->flag&INTEGER)) {
/* string dest */
if ((vq->flag&ALLOC)) {
#ifndef MKSH_SMALL
/* debugging */
if (s >= vq->val.s &&
s <= vq->val.s + strlen(vq->val.s)) {
internal_errorf(
"setstr: %s=%s: assigning to self",
vq->name, s);
}
#endif
afree(vq->val.s, vq->areap);
}
vq->flag &= ~(ISSET|ALLOC);
vq->type = 0;
if (s && (vq->flag & (UCASEV_AL|LCASEV|LJUST|RJUST)))
s = salloc = formatstr(vq, s);
if ((vq->flag&EXPORT))
exportprep(vq, s);
else {
strdupx(vq->val.s, s, vq->areap);
vq->flag |= ALLOC;
}
} else {
/* integer dest */
if (!v_evaluate(vq, s, error_ok, true))
return (0);
}
vq->flag |= ISSET;
if ((vq->flag&SPECIAL))
setspec(vq);
afree(salloc, ATEMP);
return (1);
}
/* set variable to integer */
void
setint(struct tbl *vq, mksh_ari_t n)
{
if (!(vq->flag&INTEGER)) {
struct tbl *vp = &vtemp;
vp->flag = (ISSET|INTEGER);
vp->type = 0;
vp->areap = ATEMP;
vp->val.i = n;
/* setstr can't fail here */
setstr(vq, str_val(vp), KSH_RETURN_ERROR);
} else
vq->val.i = n;
vq->flag |= ISSET;
if ((vq->flag&SPECIAL))
setspec(vq);
}
static int
getint(struct tbl *vp, mksh_ari_u *nump, bool arith)
{
mksh_uari_t c, num, base;
const char *s;
bool have_base = false, neg = false;
if (vp->flag&SPECIAL)
getspec(vp);
/* XXX is it possible for ISSET to be set and val.s to be NULL? */
if (!(vp->flag&ISSET) || (!(vp->flag&INTEGER) && vp->val.s == NULL))
return (-1);
if (vp->flag&INTEGER) {
nump->i = vp->val.i;
return (vp->type);
}
s = vp->val.s + vp->type;
base = 10;
num = 0;
if (arith && s[0] == '0' && (s[1] | 0x20) == 'x') {
s += 2;
base = 16;
have_base = true;
}
if (Flag(FPOSIX) && arith && s[0] == '0' && ksh_isdigit(s[1]) &&
!(vp->flag & ZEROFIL)) {
/* interpret as octal (deprecated) */
base = 8;
have_base = true;
}
while ((c = (unsigned char)*s++)) {
if (c == '-') {
neg = true;
continue;
} else if (c == '#') {
if (have_base || num < 1)
return (-1);
if ((base = num) == 1) {
unsigned int wc;
if (!UTFMODE)
wc = *(const unsigned char *)s;
else if (utf_mbtowc(&wc, s) == (size_t)-1)
/* OPTU-8 -> OPTU-16 */
/*
* (with a twist: 1#\uEF80 converts
* the same as 1#\x80 does, thus is
* not round-tripping correctly XXX)
*/
wc = 0xEF00 + *(const unsigned char *)s;
nump->u = (mksh_uari_t)wc;
return (1);
} else if (base > 36)
base = 10;
num = 0;
have_base = true;
continue;
} else if (ksh_isdigit(c))
c -= '0';
else if (ksh_islower(c))
c -= 'a' - 10;
else if (ksh_isupper(c))
c -= 'A' - 10;
else
return (-1);
if (c >= base)
return (-1);
num = num * base + c;
}
if (neg)
num = -num;
nump->u = num;
return (base);
}
/*
* convert variable vq to integer variable, setting its value from vp
* (vq and vp may be the same)
*/
struct tbl *
setint_v(struct tbl *vq, struct tbl *vp, bool arith)
{
int base;
mksh_ari_u num;
if ((base = getint(vp, &num, arith)) == -1)
return (NULL);
setint_n(vq, num.i, 0);
if (vq->type == 0)
/* default base */
vq->type = base;
return (vq);
}
/* convert variable vq to integer variable, setting its value to num */
void
setint_n(struct tbl *vq, mksh_ari_t num, int newbase)
{
if (!(vq->flag & INTEGER) && (vq->flag & ALLOC)) {
vq->flag &= ~ALLOC;
vq->type = 0;
afree(vq->val.s, vq->areap);
}
vq->val.i = num;
if (newbase != 0)
vq->type = newbase;
vq->flag |= ISSET|INTEGER;
if (vq->flag&SPECIAL)
setspec(vq);
}
static char *
formatstr(struct tbl *vp, const char *s)
{
int olen, nlen;
char *p, *q;
size_t psiz;
olen = (int)utf_mbswidth(s);
if (vp->flag & (RJUST|LJUST)) {
if (!vp->u2.field)
/* default field width */
vp->u2.field = olen;
nlen = vp->u2.field;
} else
nlen = olen;
p = alloc((psiz = nlen * /* MB_LEN_MAX */ 3 + 1), ATEMP);
if (vp->flag & (RJUST|LJUST)) {
int slen = olen, i = 0;
if (vp->flag & RJUST) {
const char *qq = s;
int n = 0;
while (i < slen)
i += utf_widthadj(qq, &qq);
/* strip trailing spaces (AT&T uses qq[-1] == ' ') */
while (qq > s && ksh_isspace(qq[-1])) {
--qq;
--slen;
}
if (vp->flag & ZEROFIL && vp->flag & INTEGER) {
if (!s[0] || !s[1])
goto uhm_no;
if (s[1] == '#')
n = 2;
else if (s[2] == '#')
n = 3;
uhm_no:
if (vp->u2.field <= n)
n = 0;
}
if (n) {
memcpy(p, s, n);
s += n;
}
while (slen > vp->u2.field)
slen -= utf_widthadj(s, &s);
if (vp->u2.field - slen)
memset(p + n, (vp->flag & ZEROFIL) ? '0' : ' ',
vp->u2.field - slen);
slen -= n;
shf_snprintf(p + vp->u2.field - slen,
psiz - (vp->u2.field - slen),
"%.*s", slen, s);
} else {
/* strip leading spaces/zeros */
while (ksh_isspace(*s))
s++;
if (vp->flag & ZEROFIL)
while (*s == '0')
s++;
shf_snprintf(p, nlen + 1, "%-*.*s",
vp->u2.field, vp->u2.field, s);
}
} else
memcpy(p, s, strlen(s) + 1);
if (vp->flag & UCASEV_AL) {
for (q = p; *q; q++)
*q = ksh_toupper(*q);
} else if (vp->flag & LCASEV) {
for (q = p; *q; q++)
*q = ksh_tolower(*q);
}
return (p);
}
/*
* make vp->val.s be "name=value" for quick exporting.
*/
static void
exportprep(struct tbl *vp, const char *val)
{
char *xp;
char *op = (vp->flag&ALLOC) ? vp->val.s : NULL;
size_t namelen, vallen;
namelen = strlen(vp->name);
vallen = strlen(val) + 1;
vp->flag |= ALLOC;
/* since name+val are both in memory this can go unchecked */
xp = alloc(namelen + 1 + vallen, vp->areap);
memcpy(vp->val.s = xp, vp->name, namelen);
xp += namelen;
*xp++ = '=';
/* offset to value */
vp->type = xp - vp->val.s;
memcpy(xp, val, vallen);
if (op != NULL)
afree(op, vp->areap);
}
/*
* lookup variable (according to (set&LOCAL)), set its attributes
* (INTEGER, RDONLY, EXPORT, TRACE, LJUST, RJUST, ZEROFIL, LCASEV,
* UCASEV_AL), and optionally set its value if an assignment.
*/
struct tbl *
typeset(const char *var, uint32_t set, uint32_t clr, int field, int base)
{
struct tbl *vp;
struct tbl *vpbase, *t;
char *tvar;
const char *val;
size_t len;
bool vappend = false;
enum namerefflag new_refflag = SRF_NOP;
if ((set & (ARRAY | ASSOC)) == ASSOC) {
new_refflag = SRF_ENABLE;
set &= ~(ARRAY | ASSOC);
}
if ((clr & (ARRAY | ASSOC)) == ASSOC) {
new_refflag = SRF_DISABLE;
clr &= ~(ARRAY | ASSOC);
}
/* check for valid variable name, search for value */
val = skip_varname(var, false);
if (val == var) {
/* no variable name given */
return (NULL);
}
if (*val == '[') {
if (new_refflag != SRF_NOP)
errorf("%s: %s", var,
"reference variable can't be an array");
len = array_ref_len(val);
if (len == 0)
return (NULL);
/*
* IMPORT is only used when the shell starts up and is
* setting up its environment. Allow only simple array
* references at this time since parameter/command
* substitution is performed on the [expression] which
* would be a major security hole.
*/
if (set & IMPORT) {
size_t i;
for (i = 1; i < len - 1; i++)
if (!ksh_isdigit(val[i]))
return (NULL);
}
val += len;
}
if (val[0] == '=') {
strndupx(tvar, var, val - var, ATEMP);
++val;
} else if (set & IMPORT) {
/* environment invalid variable name or no assignment */
return (NULL);
} else if (val[0] == '+' && val[1] == '=') {
strndupx(tvar, var, val - var, ATEMP);
val += 2;
vappend = true;
} else if (val[0] != '\0') {
/* other invalid variable names (not from environment) */
return (NULL);
} else {
/* just varname with no value part nor equals sign */
strdupx(tvar, var, ATEMP);
val = NULL;
/* handle foo[*] => foo (whole array) mapping for R39b */
len = strlen(tvar);
if (len > 3 && tvar[len - 3] == '[' && tvar[len - 2] == '*' &&
tvar[len - 1] == ']')
tvar[len - 3] = '\0';
}
if (new_refflag == SRF_ENABLE) {
const char *qval, *ccp;
/* bail out on 'nameref foo+=bar' */
if (vappend)
errorf("appending not allowed for nameref");
/* find value if variable already exists */
if ((qval = val) == NULL) {
varsearch(e->loc, &vp, tvar, hash(tvar));
if (vp == NULL)
goto nameref_empty;
qval = str_val(vp);
}
/* check target value for being a valid variable name */
ccp = skip_varname(qval, false);
if (ccp == qval) {
if (ksh_isdigit(qval[0])) {
int c;
if (getn(qval, &c))
goto nameref_rhs_checked;
} else if (qval[1] == '\0') switch (qval[0]) {
case '$':
case '!':
case '?':
case '#':
case '-':
goto nameref_rhs_checked;
}
nameref_empty:
errorf("%s: %s", var, "empty nameref target");
}
len = (*ccp == '[') ? array_ref_len(ccp) : 0;
if (ccp[len]) {
/*
* works for cases "no array", "valid array with
* junk after it" and "invalid array"; in the
* latter case, len is also 0 and points to '['
*/
errorf("%s: %s", qval,
"nameref target not a valid parameter name");
}
nameref_rhs_checked:
/* prevent nameref loops */
while (qval) {
if (!strcmp(qval, tvar))
errorf("%s: %s", qval,
"expression recurses on parameter");
varsearch(e->loc, &vp, qval, hash(qval));
qval = NULL;
if (vp && ((vp->flag & (ARRAY | ASSOC)) == ASSOC))
qval = str_val(vp);
}
}
/* prevent typeset from creating a local PATH/ENV/SHELL */
if (Flag(FRESTRICTED) && (strcmp(tvar, "PATH") == 0 ||
strcmp(tvar, "ENV") == 0 || strcmp(tvar, "SHELL") == 0))
errorf("%s: %s", tvar, "restricted");
innermost_refflag = new_refflag;
vp = (set & LOCAL) ? local(tvar, tobool(set & LOCAL_COPY)) :
global(tvar);
if (new_refflag == SRF_DISABLE && (vp->flag & (ARRAY|ASSOC)) == ASSOC)
vp->flag &= ~ASSOC;
else if (new_refflag == SRF_ENABLE) {
if (vp->flag & ARRAY) {
struct tbl *a, *tmp;
/* free up entire array */
for (a = vp->u.array; a; ) {
tmp = a;
a = a->u.array;
if (tmp->flag & ALLOC)
afree(tmp->val.s, tmp->areap);
afree(tmp, tmp->areap);
}
vp->u.array = NULL;
vp->flag &= ~ARRAY;
}
vp->flag |= ASSOC;
}
set &= ~(LOCAL|LOCAL_COPY);
vpbase = (vp->flag & ARRAY) ? global(arrayname(tvar)) : vp;
/*
* only allow export flag to be set; AT&T ksh allows any
* attribute to be changed which means it can be truncated or
* modified (-L/-R/-Z/-i)
*/
if ((vpbase->flag & RDONLY) &&
(val || clr || (set & ~EXPORT)))
/* XXX check calls - is error here ok by POSIX? */
errorfx(2, "read-only: %s", tvar);
afree(tvar, ATEMP);
/* most calls are with set/clr == 0 */
if (set | clr) {
bool ok = true;
/*
* XXX if x[0] isn't set, there will be problems: need
* to have one copy of attributes for arrays...
*/
for (t = vpbase; t; t = t->u.array) {
bool fake_assign;
char *s = NULL;
char *free_me = NULL;
fake_assign = (t->flag & ISSET) && (!val || t != vp) &&
((set & (UCASEV_AL|LCASEV|LJUST|RJUST|ZEROFIL)) ||
((t->flag & INTEGER) && (clr & INTEGER)) ||
(!(t->flag & INTEGER) && (set & INTEGER)));
if (fake_assign) {
if (t->flag & INTEGER) {
s = str_val(t);
free_me = NULL;
} else {
s = t->val.s + t->type;
free_me = (t->flag & ALLOC) ? t->val.s :
NULL;
}
t->flag &= ~ALLOC;
}
if (!(t->flag & INTEGER) && (set & INTEGER)) {
t->type = 0;
t->flag &= ~ALLOC;
}
t->flag = (t->flag | set) & ~clr;
/*
* Don't change base if assignment is to be
* done, in case assignment fails.
*/
if ((set & INTEGER) && base > 0 && (!val || t != vp))
t->type = base;
if (set & (LJUST|RJUST|ZEROFIL))
t->u2.field = field;
if (fake_assign) {
if (!setstr(t, s, KSH_RETURN_ERROR)) {
/*
* Somewhat arbitrary action
* here: zap contents of
* variable, but keep the flag
* settings.
*/
ok = false;
if (t->flag & INTEGER)
t->flag &= ~ISSET;
else {
if (t->flag & ALLOC)
afree(t->val.s, t->areap);
t->flag &= ~(ISSET|ALLOC);
t->type = 0;
}
}
if (free_me)
afree(free_me, t->areap);
}
}
if (!ok)
errorfz();
}
if (val != NULL) {
char *tval;
if (vappend) {
tval = shf_smprintf("%s%s", str_val(vp), val);
val = tval;
} else
tval = NULL;
if (vp->flag&INTEGER) {
/* do not zero base before assignment */
setstr(vp, val, KSH_UNWIND_ERROR | 0x4);
/* done after assignment to override default */
if (base > 0)
vp->type = base;
} else
/* setstr can't fail (readonly check already done) */
setstr(vp, val, KSH_RETURN_ERROR | 0x4);
if (tval != NULL)
afree(tval, ATEMP);
}
/* only x[0] is ever exported, so use vpbase */
if ((vpbase->flag&EXPORT) && !(vpbase->flag&INTEGER) &&
vpbase->type == 0)
exportprep(vpbase, (vpbase->flag&ISSET) ? vpbase->val.s : null);
return (vp);
}
/**
* Unset a variable. The flags can be:
* |1 = tear down entire array
* |2 = keep attributes, only unset content
*/
void
unset(struct tbl *vp, int flags)
{
if (vp->flag & ALLOC)
afree(vp->val.s, vp->areap);
if ((vp->flag & ARRAY) && (flags & 1)) {
struct tbl *a, *tmp;
/* free up entire array */
for (a = vp->u.array; a; ) {
tmp = a;
a = a->u.array;
if (tmp->flag & ALLOC)
afree(tmp->val.s, tmp->areap);
afree(tmp, tmp->areap);
}
vp->u.array = NULL;
}
if (flags & 2) {
vp->flag &= ~(ALLOC|ISSET);
return;
}
/* if foo[0] is being unset, the remainder of the array is kept... */
vp->flag &= SPECIAL | ((flags & 1) ? 0 : ARRAY|DEFINED);
if (vp->flag & SPECIAL)
/* responsible for 'unspecial'ing var */
unsetspec(vp);
}
/*
* Return a pointer to the first char past a legal variable name
* (returns the argument if there is no legal name, returns a pointer to
* the terminating NUL if whole string is legal).
*/
const char *
skip_varname(const char *s, bool aok)
{
size_t alen;
if (s && ksh_isalphx(*s)) {
while (*++s && ksh_isalnux(*s))
;
if (aok && *s == '[' && (alen = array_ref_len(s)))
s += alen;
}
return (s);
}
/* Return a pointer to the first character past any legal variable name */
const char *
skip_wdvarname(const char *s,
/* skip array de-reference? */
bool aok)
{
if (s[0] == CHAR && ksh_isalphx(s[1])) {
do {
s += 2;
} while (s[0] == CHAR && ksh_isalnux(s[1]));
if (aok && s[0] == CHAR && s[1] == '[') {
/* skip possible array de-reference */
const char *p = s;
char c;
int depth = 0;
while (/* CONSTCOND */ 1) {
if (p[0] != CHAR)
break;
c = p[1];
p += 2;
if (c == '[')
depth++;
else if (c == ']' && --depth == 0) {
s = p;
break;
}
}
}
}
return (s);
}
/* Check if coded string s is a variable name */
int
is_wdvarname(const char *s, bool aok)
{
const char *p = skip_wdvarname(s, aok);
return (p != s && p[0] == EOS);
}
/* Check if coded string s is a variable assignment */
int
is_wdvarassign(const char *s)
{
const char *p = skip_wdvarname(s, true);
return (p != s && p[0] == CHAR &&
(p[1] == '=' || (p[1] == '+' && p[2] == CHAR && p[3] == '=')));
}
/*
* Make the exported environment from the exported names in the dictionary.
*/
char **
makenv(void)
{
ssize_t i;
struct block *l;
XPtrV denv;
struct tbl *vp, **vpp;
XPinit(denv, 64);
for (l = e->loc; l != NULL; l = l->next) {
vpp = l->vars.tbls;
i = 1 << (l->vars.tshift);
while (--i >= 0)
if ((vp = *vpp++) != NULL &&
(vp->flag&(ISSET|EXPORT)) == (ISSET|EXPORT)) {
struct block *l2;
struct tbl *vp2;
uint32_t h = hash(vp->name);
/* unexport any redefined instances */
for (l2 = l->next; l2 != NULL; l2 = l2->next) {
vp2 = ktsearch(&l2->vars, vp->name, h);
if (vp2 != NULL)
vp2->flag &= ~EXPORT;
}
if ((vp->flag&INTEGER)) {
/* integer to string */
char *val;
val = str_val(vp);
vp->flag &= ~(INTEGER|RDONLY|SPECIAL);
/* setstr can't fail here */
setstr(vp, val, KSH_RETURN_ERROR);
}
XPput(denv, vp->val.s);
}
if (l->flags & BF_STOPENV)
break;
}
XPput(denv, NULL);
return ((char **)XPclose(denv));
}
/*
* handle special variables with side effects - PATH, SECONDS.
*/
/* Test if name is a special parameter */
static int
special(const char *name)
{
struct tbl *tp;
tp = ktsearch(&specials, name, hash(name));
return (tp && (tp->flag & ISSET) ? tp->type : V_NONE);
}
/* Make a variable non-special */
static void
unspecial(const char *name)
{
struct tbl *tp;
tp = ktsearch(&specials, name, hash(name));
if (tp)
ktdelete(tp);
}
static time_t seconds; /* time SECONDS last set */
static int user_lineno; /* what user set $LINENO to */
static void
getspec(struct tbl *vp)
{
mksh_ari_u num;
int st;
struct timeval tv;
switch ((st = special(vp->name))) {
case V_COLUMNS:
case V_LINES:
/*
* Do NOT export COLUMNS/LINES. Many applications
* check COLUMNS/LINES before checking ws.ws_col/row,
* so if the app is started with C/L in the environ
* and the window is then resized, the app won't
* see the change cause the environ doesn't change.
*/
if (got_winch)
change_winsz();
break;
}
switch (st) {
case V_BASHPID:
num.u = (mksh_uari_t)procpid;
break;
case V_COLUMNS:
num.i = x_cols;
break;
case V_HISTSIZE:
num.i = histsize;
break;
case V_LINENO:
num.i = current_lineno + user_lineno;
break;
case V_LINES:
num.i = x_lins;
break;
case V_EPOCHREALTIME: {
/* 10(%u) + 1(.) + 6 + NUL */
char buf[18];
vp->flag &= ~SPECIAL;
mksh_TIME(tv);
shf_snprintf(buf, sizeof(buf), "%u.%06u",
(unsigned)tv.tv_sec, (unsigned)tv.tv_usec);
setstr(vp, buf, KSH_RETURN_ERROR | 0x4);
vp->flag |= SPECIAL;
return;
}
case V_OPTIND:
num.i = user_opt.uoptind;
break;
case V_RANDOM:
num.i = rndget();
break;
case V_SECONDS:
/*
* On start up the value of SECONDS is used before
* it has been set - don't do anything in this case
* (see initcoms[] in main.c).
*/
if (vp->flag & ISSET) {
mksh_TIME(tv);
num.i = tv.tv_sec - seconds;
} else
return;
break;
default:
/* do nothing, do not touch vp at all */
return;
}
vp->flag &= ~SPECIAL;
setint_n(vp, num.i, 0);
vp->flag |= SPECIAL;
}
static void
setspec(struct tbl *vp)
{
mksh_ari_u num;
char *s;
int st;
switch ((st = special(vp->name))) {
#if HAVE_PERSISTENT_HISTORY
case V_HISTFILE:
sethistfile(str_val(vp));
return;
#endif
case V_IFS:
setctypes(s = str_val(vp), C_IFS);
ifs0 = *s;
return;
case V_PATH:
if (path)
afree(path, APERM);
s = str_val(vp);
strdupx(path, s, APERM);
/* clear tracked aliases */
flushcom(true);
return;
case V_TMPDIR:
if (tmpdir) {
afree(tmpdir, APERM);
tmpdir = NULL;
}
/*
* Use tmpdir iff it is an absolute path, is writable
* and searchable and is a directory...
*/
{
struct stat statb;
s = str_val(vp);
/* LINTED use of access */
if (s[0] == '/' && access(s, W_OK|X_OK) == 0 &&
stat(s, &statb) == 0 && S_ISDIR(statb.st_mode))
strdupx(tmpdir, s, APERM);
}
return;
/* common sub-cases */
case V_COLUMNS:
case V_LINES:
if (vp->flag & IMPORT) {
/* do not touch */
unspecial(vp->name);
vp->flag &= ~SPECIAL;
return;
}
/* FALLTHROUGH */
case V_HISTSIZE:
case V_LINENO:
case V_OPTIND:
case V_RANDOM:
case V_SECONDS:
case V_TMOUT:
vp->flag &= ~SPECIAL;
if (getint(vp, &num, false) == -1) {
s = str_val(vp);
if (st != V_RANDOM)
errorf("%s: %s: %s", vp->name, "bad number", s);
num.u = hash(s);
}
vp->flag |= SPECIAL;
break;
default:
/* do nothing, do not touch vp at all */
return;
}
/* process the singular parts of the common cases */
switch (st) {
case V_COLUMNS:
if (num.i >= MIN_COLS)
x_cols = num.i;
break;
case V_HISTSIZE:
sethistsize(num.i);
break;
case V_LINENO:
/* The -1 is because line numbering starts at 1. */
user_lineno = num.u - current_lineno - 1;
break;
case V_LINES:
if (num.i >= MIN_LINS)
x_lins = num.i;
break;
case V_OPTIND:
getopts_reset((int)num.i);
break;
case V_RANDOM:
/*
* mksh R39d+ no longer has the traditional repeatability
* of $RANDOM sequences, but always retains state
*/
rndset((unsigned long)num.u);
break;
case V_SECONDS:
{
struct timeval tv;
mksh_TIME(tv);
seconds = tv.tv_sec - num.i;
}
break;
case V_TMOUT:
ksh_tmout = num.i >= 0 ? num.i : 0;
break;
}
}
static void
unsetspec(struct tbl *vp)
{
/*
* AT&T ksh man page says OPTIND, OPTARG and _ lose special
* meaning, but OPTARG does not (still set by getopts) and _ is
* also still set in various places. Don't know what AT&T does
* for HISTSIZE, HISTFILE. Unsetting these in AT&T ksh does not
* loose the 'specialness': IFS, COLUMNS, PATH, TMPDIR
*/
switch (special(vp->name)) {
#if HAVE_PERSISTENT_HISTORY
case V_HISTFILE:
sethistfile(NULL);
return;
#endif
case V_IFS:
setctypes(TC_IFSWS, C_IFS);
ifs0 = ' ';
break;
case V_PATH:
if (path)
afree(path, APERM);
strdupx(path, def_path, APERM);
/* clear tracked aliases */
flushcom(true);
break;
case V_TMPDIR:
/* should not become unspecial */
if (tmpdir) {
afree(tmpdir, APERM);
tmpdir = NULL;
}
break;
case V_LINENO:
case V_RANDOM:
case V_SECONDS:
case V_TMOUT:
/* AT&T ksh leaves previous value in place */
unspecial(vp->name);
break;
}
}
/*
* Search for (and possibly create) a table entry starting with
* vp, indexed by val.
*/
struct tbl *
arraysearch(struct tbl *vp, uint32_t val)
{
struct tbl *prev, *curr, *news;
size_t len;
vp->flag = (vp->flag | (ARRAY | DEFINED)) & ~ASSOC;
/* the table entry is always [0] */
if (val == 0)
return (vp);
prev = vp;
curr = vp->u.array;
while (curr && curr->ua.index < val) {
prev = curr;
curr = curr->u.array;
}
if (curr && curr->ua.index == val) {
if (curr->flag&ISSET)
return (curr);
news = curr;
} else
news = NULL;
if (!news) {
len = strlen(vp->name);
checkoktoadd(len, 1 + offsetof(struct tbl, name[0]));
news = alloc(offsetof(struct tbl, name[0]) + ++len, vp->areap);
memcpy(news->name, vp->name, len);
}
news->flag = (vp->flag & ~(ALLOC|DEFINED|ISSET|SPECIAL)) | AINDEX;
news->type = vp->type;
news->areap = vp->areap;
news->u2.field = vp->u2.field;
news->ua.index = val;
if (curr != news) {
/* not reusing old array entry */
prev->u.array = news;
news->u.array = curr;
}
return (news);
}
/*
* Return the length of an array reference (eg, [1+2]) - cp is assumed
* to point to the open bracket. Returns 0 if there is no matching
* closing bracket.
*
* XXX this should parse the actual arithmetic syntax
*/
size_t
array_ref_len(const char *cp)
{
const char *s = cp;
char c;
int depth = 0;
while ((c = *s++) && (c != ']' || --depth))
if (c == '[')
depth++;
if (!c)
return (0);
return (s - cp);
}
/*
* Make a copy of the base of an array name
*/
char *
arrayname(const char *str)
{
const char *p;
char *rv;
if ((p = cstrchr(str, '[')) == 0)
/* Shouldn't happen, but why worry? */
strdupx(rv, str, ATEMP);
else
strndupx(rv, str, p - str, ATEMP);
return (rv);
}
/* set (or overwrite, if reset) the array variable var to the values in vals */
mksh_uari_t
set_array(const char *var, bool reset, const char **vals)
{
struct tbl *vp, *vq;
mksh_uari_t i = 0, j = 0;
const char *ccp = var;
char *cp = NULL;
size_t n;
/* to get local array, use "local foo; set -A foo" */
n = strlen(var);
if (n > 0 && var[n - 1] == '+') {
/* append mode */
reset = false;
strndupx(cp, var, n - 1, ATEMP);
ccp = cp;
}
vp = global(ccp);
/* Note: AT&T ksh allows set -A but not set +A of a read-only var */
if ((vp->flag&RDONLY))
errorfx(2, "read-only: %s", ccp);
/* This code is quite non-optimal */
if (reset) {
/* trash existing values and attributes */
unset(vp, 1);
/* allocate-by-access the [0] element to keep in scope */
arraysearch(vp, 0);
}
/*
* TODO: would be nice for assignment to completely succeed or
* completely fail. Only really effects integer arrays:
* evaluation of some of vals[] may fail...
*/
if (cp != NULL) {
/* find out where to set when appending */
for (vq = vp; vq; vq = vq->u.array) {
if (!(vq->flag & ISSET))
continue;
if (arrayindex(vq) >= j)
j = arrayindex(vq) + 1;
}
afree(cp, ATEMP);
}
while ((ccp = vals[i])) {
#if 0 /* temporarily taken out due to regression */
if (*ccp == '[') {
int level = 0;
while (*ccp) {
if (*ccp == ']' && --level == 0)
break;
if (*ccp == '[')
++level;
++ccp;
}
if (*ccp == ']' && level == 0 && ccp[1] == '=') {
strndupx(cp, vals[i] + 1, ccp - (vals[i] + 1),
ATEMP);
evaluate(substitute(cp, 0), (mksh_ari_t *)&j,
KSH_UNWIND_ERROR, true);
afree(cp, ATEMP);
ccp += 2;
} else
ccp = vals[i];
}
#endif
vq = arraysearch(vp, j);
/* would be nice to deal with errors here... (see above) */
setstr(vq, ccp, KSH_RETURN_ERROR);
i++;
j++;
}
return (i);
}
void
change_winsz(void)
{
struct timeval tv;
mksh_TIME(tv);
BAFHUpdateMem_mem(qh_state, &tv, sizeof(tv));
#ifdef TIOCGWINSZ
/* check if window size has changed */
if (tty_init_fd() < 2) {
struct winsize ws;
if (ioctl(tty_fd, TIOCGWINSZ, &ws) >= 0) {
if (ws.ws_col)
x_cols = ws.ws_col;
if (ws.ws_row)
x_lins = ws.ws_row;
}
}
#endif
/* bounds check for sane values, use defaults otherwise */
if (x_cols < MIN_COLS)
x_cols = 80;
if (x_lins < MIN_LINS)
x_lins = 24;
#ifdef SIGWINCH
got_winch = 0;
#endif
}
uint32_t
hash(const void *s)
{
register uint32_t h;
BAFHInit(h);
BAFHUpdateStr_reg(h, s);
BAFHFinish_reg(h);
return (h);
}
uint32_t
chvt_rndsetup(const void *bp, size_t sz)
{
register uint32_t h;
/* use LCG as seed but try to get them to deviate immediately */
h = lcg_state;
(void)rndget();
BAFHFinish_reg(h);
/* variation through pid, ppid, and the works */
BAFHUpdateMem_reg(h, &rndsetupstate, sizeof(rndsetupstate));
/* some variation, some possibly entropy, depending on OE */
BAFHUpdateMem_reg(h, bp, sz);
/* mix them all up */
BAFHFinish_reg(h);
return (h);
}
mksh_ari_t
rndget(void)
{
/*
* this is the same Linear Congruential PRNG as Borland
* C/C++ allegedly uses in its built-in rand() function
*/
return (((lcg_state = 22695477 * lcg_state + 1) >> 16) & 0x7FFF);
}
void
rndset(unsigned long v)
{
register uint32_t h;
#if defined(arc4random_pushb_fast) || defined(MKSH_A4PB)
register uint32_t t;
#endif
struct {
struct timeval tv;
void *sp;
uint32_t qh;
pid_t pp;
short r;
} z;
#ifdef DEBUG
/* clear the allocated space, for valgrind */
memset(&z, 0, sizeof(z));
#endif
h = lcg_state;
BAFHFinish_reg(h);
BAFHUpdateMem_reg(h, &v, sizeof(v));
mksh_TIME(z.tv);
z.sp = &lcg_state;
z.pp = procpid;
z.r = (short)rndget();
#if defined(arc4random_pushb_fast) || defined(MKSH_A4PB)
t = qh_state;
BAFHFinish_reg(t);
z.qh = (t & 0xFFFF8000) | rndget();
lcg_state = (t << 15) | rndget();
/*
* either we have very chap entropy get and push available,
* with malloc() pulling in this code already anyway, or the
* user requested us to use the old functions
*/
t = h;
BAFHUpdateMem_reg(t, &lcg_state, sizeof(lcg_state));
BAFHFinish_reg(t);
lcg_state = t;
#if defined(arc4random_pushb_fast)
arc4random_pushb_fast(&lcg_state, sizeof(lcg_state));
lcg_state = arc4random();
#else
lcg_state = arc4random_pushb(&lcg_state, sizeof(lcg_state));
#endif
BAFHUpdateMem_reg(h, &lcg_state, sizeof(lcg_state));
#else
z.qh = qh_state;
#endif
BAFHUpdateMem_reg(h, &z, sizeof(z));
BAFHFinish_reg(h);
lcg_state = h;
}
void
rndpush(const void *s)
{
register uint32_t h = qh_state;
BAFHUpdateStr_reg(h, s);
BAFHUpdateOctet_reg(h, 0);
qh_state = h;
}
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