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ash: use glob() from libc

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Adapted from dash.
The "homegrown" glob code is retained (ifdef'ed out).
This changes was inspired by bug 9261, which detected out-of bounds use of heap
for 2098 byte long name in the "homegrown" code. This is still not fixed...

function                                             old     new   delta
expandarg                                            960     982     +22
static.syntax_index_table                             26      25      -1
static.spec_symbls                                    27      26      -1
static.metachars                                       4       -      -4
addfname                                              42       -     -42
msort                                                126       -    -126
expmeta                                              528       -    -528
------------------------------------------------------------------------------
(add/remove: 0/4 grow/shrink: 1/2 up/down: 22/-702)          Total: -680 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2016-09-21 16:25:58 +02:00
parent d8330ca4a4
commit b3f29b452a
1 changed files with 91 additions and 11 deletions
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102
shell/ash.c
View File

@ -39,6 +39,7 @@
#include <setjmp.h>
#include <fnmatch.h>
#include <glob.h>
#include <sys/times.h>
#include <sys/utsname.h> /* for setting $HOSTNAME */
@ -2808,18 +2809,27 @@ enum {
static int
SIT(int c, int syntax)
{
static const char spec_symbls[] ALIGN1 = "\t\n !\"$&'()*-/:;<=>?[\\]`|}~";
/* Used to also have '/' in this string: "\t\n !\"$&'()*-/:;<=>?[\\]`|}~" */
static const char spec_symbls[] ALIGN1 = "\t\n !\"$&'()*-:;<=>?[\\]`|}~";
/*
* This causes '/' to be prepended with CTLESC in dquoted string,
* making "./file"* treated incorrectly because we feed
* ".\/file*" string to glob(), confusing it (see expandmeta func).
* The "homegrown" glob implementation is okay with that,
* but glibc one isn't. With '/' always treated as CWORD,
* both work fine.
*/
# if ENABLE_ASH_ALIAS
static const uint8_t syntax_index_table[] ALIGN1 = {
1, 2, 1, 3, 4, 5, 1, 6, /* "\t\n !\"$&'" */
7, 8, 3, 3, 3, 3, 1, 1, /* "()*-/:;<" */
7, 8, 3, 3,/*3,*/3, 1, 1, /* "()*-/:;<" */
3, 1, 3, 3, 9, 3, 10, 1, /* "=>?[\\]`|" */
11, 3 /* "}~" */
};
# else
static const uint8_t syntax_index_table[] ALIGN1 = {
0, 1, 0, 2, 3, 4, 0, 5, /* "\t\n !\"$&'" */
6, 7, 2, 2, 2, 2, 0, 0, /* "()*-/:;<" */
6, 7, 2, 2,/*2,*/2, 0, 0, /* "()*-/:;<" */
2, 0, 2, 2, 8, 2, 9, 0, /* "=>?[\\]`|" */
10, 2 /* "}~" */
};
@ -2901,7 +2911,8 @@ static const uint8_t syntax_index_table[] ALIGN1 = {
/* 44 "," */ CWORD_CWORD_CWORD_CWORD,
/* 45 "-" */ CWORD_CCTL_CCTL_CWORD,
/* 46 "." */ CWORD_CWORD_CWORD_CWORD,
/* 47 "/" */ CWORD_CCTL_CCTL_CWORD,
/* "/" was CWORD_CCTL_CCTL_CWORD, see comment in SIT() function why this is changed: */
/* 47 "/" */ CWORD_CWORD_CWORD_CWORD,
/* 48 "0" */ CWORD_CWORD_CWORD_CWORD,
/* 49 "1" */ CWORD_CWORD_CWORD_CWORD,
/* 50 "2" */ CWORD_CWORD_CWORD_CWORD,
@ -5633,7 +5644,6 @@ rmescapes(char *str, int flag)
while (*p) {
if ((unsigned char)*p == CTLQUOTEMARK) {
// Note: both inquotes and protect_against_glob only affect whether
// CTLESC,<ch> gets converted to <ch> or to \<ch>
inquotes = ~inquotes;
p++;
protect_against_glob = globbing;
@ -5697,11 +5707,14 @@ memtodest(const char *p, size_t len, int syntax, int quotes)
unsigned char c = *p++;
if (c) {
int n = SIT(c, syntax);
if ((quotes & QUOTES_ESC) &&
((n == CCTL) ||
(((quotes & EXP_FULL) || syntax != BASESYNTAX) &&
n == CBACK)))
if ((quotes & QUOTES_ESC)
&& ((n == CCTL)
|| (((quotes & EXP_FULL) || syntax != BASESYNTAX)
&& n == CBACK)
)
) {
USTPUTC(CTLESC, q);
}
} else if (!(quotes & QUOTES_KEEPNUL))
continue;
USTPUTC(c, q);
@ -6435,7 +6448,8 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
char *idx, *end;
if (!repl) {
if ((repl=strchr(str, CTLESC)))
repl = strchr(str, CTLESC);
if (repl)
*repl++ = '\0';
else
repl = nullstr;
@ -6976,6 +6990,70 @@ addfname(const char *name)
exparg.lastp = &sp->next;
}
/* If we want to use glob() from libc... */
#if 1
/* Add the result of glob() to the list */
static void
addglob(const glob_t *pglob)
{
char **p = pglob->gl_pathv;
do {
addfname(*p);
} while (*++p);
}
static void
expandmeta(struct strlist *str /*, int flag*/)
{
/* TODO - EXP_REDIR */
while (str) {
char *p;
glob_t pglob;
int i;
if (fflag)
goto nometa;
INT_OFF;
p = preglob(str->text, RMESCAPE_ALLOC | RMESCAPE_HEAP);
/*
* GLOB_NOMAGIC (GNU): if no *?[ chars in pattern, return it even if no match
* TODO?: GLOB_NOCHECK: if no match, return unchanged pattern (sans \* escapes?)
*/
i = glob(p, GLOB_NOMAGIC, NULL, &pglob);
if (p != str->text)
free(p);
switch (i) {
case 0:
/* GLOB_MAGCHAR is set if *?[ chars were seen (GNU) */
if (!(pglob.gl_flags & GLOB_MAGCHAR))
goto nometa2;
addglob(&pglob);
globfree(&pglob);
INT_ON;
break;
case GLOB_NOMATCH:
nometa2:
globfree(&pglob);
INT_ON;
nometa:
*exparg.lastp = str;
rmescapes(str->text, 0);
exparg.lastp = &str->next;
break;
default: /* GLOB_NOSPACE */
globfree(&pglob);
INT_ON;
ash_msg_and_raise_error(bb_msg_memory_exhausted);
}
str = str->next;
}
}
#else
/* Homegrown globbing code. (dash also has both, uses homegrown one.) */
/*
* Do metacharacter (i.e. *, ?, [...]) expansion.
*/
@ -7179,7 +7257,8 @@ expandmeta(struct strlist *str /*, int flag*/)
p = preglob(str->text, RMESCAPE_ALLOC | RMESCAPE_HEAP);
{
int i = strlen(str->text);
expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
//BUGGY estimation of how long expanded name can be
expdir = ckmalloc(i < 2048 ? 2048 : i+1);
}
expmeta(expdir, expdir, p);
free(expdir);
@ -7204,6 +7283,7 @@ expandmeta(struct strlist *str /*, int flag*/)
str = str->next;
}
}
#endif /* our globbing code */
/*
* Perform variable substitution and command substitution on an argument,