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hush: fix globbing+backslashes in unquoted $var expansion

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Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
This commit is contained in:
Denys Vlasenko 2010-09-06 10:26:37 +02:00
parent d383b49aef
commit c49d2d9793
5 changed files with 172 additions and 88 deletions
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138
shell/hush.c
View File

@ -2007,12 +2007,17 @@ static void o_addstr_with_NUL(o_string *o, const char *str)
static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
{
while (len) {
o_addchr(o, *str);
if (*str == '\\') {
o_addchr(o, '\\');
}
str++;
len--;
o_addchr(o, *str);
if (*str++ == '\\') {
/* \z -> \\\z; \<eol> -> \\<eol> */
o_addchr(o, '\\');
if (len) {
len--;
o_addchr(o, '\\');
o_addchr(o, *str++);
}
}
}
}
@ -2067,12 +2072,8 @@ static void o_addQchr(o_string *o, int ch)
o->data[o->length] = '\0';
}
static void o_addQblock(o_string *o, const char *str, int len)
static void o_addqblock(o_string *o, const char *str, int len)
{
if (!o->o_escape) {
o_addblock(o, str, len);
return;
}
while (len) {
char ch;
int sz;
@ -2099,6 +2100,15 @@ static void o_addQblock(o_string *o, const char *str, int len)
}
}
static void o_addQblock(o_string *o, const char *str, int len)
{
if (!o->o_escape) {
o_addblock(o, str, len);
return;
}
o_addqblock(o, str, len);
}
static void o_addQstr(o_string *o, const char *str)
{
o_addQblock(o, str, strlen(str));
@ -2356,11 +2366,11 @@ static int glob_brace(char *pattern, o_string *o, int n)
/* Performs globbing on last list[],
* saving each result as a new list[].
*/
static int o_glob(o_string *o, int n)
static int perform_glob(o_string *o, int n)
{
char *pattern, *copy;
debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
if (!o->data)
return o_save_ptr_helper(o, n);
pattern = o->data + o_get_last_ptr(o, n);
@ -2378,7 +2388,7 @@ static int o_glob(o_string *o, int n)
n = glob_brace(copy, o, n);
free(copy);
if (DEBUG_GLOB)
debug_print_list("o_glob returning", o, n);
debug_print_list("perform_glob returning", o, n);
return n;
}
@ -2403,13 +2413,13 @@ static int glob_needed(const char *s)
/* Performs globbing on last list[],
* saving each result as a new list[].
*/
static int o_glob(o_string *o, int n)
static int perform_glob(o_string *o, int n)
{
glob_t globdata;
int gr;
char *pattern;
debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
if (!o->data)
return o_save_ptr_helper(o, n);
pattern = o->data + o_get_last_ptr(o, n);
@ -2455,7 +2465,7 @@ static int o_glob(o_string *o, int n)
}
globfree(&globdata);
if (DEBUG_GLOB)
debug_print_list("o_glob returning", o, n);
debug_print_list("perform_glob returning", o, n);
return n;
}
@ -2470,7 +2480,7 @@ static int o_save_ptr(o_string *o, int n)
* (if it was requested back then when it was filled)
* so don't do that again! */
if (!o->has_empty_slot)
return o_glob(o, n); /* o_save_ptr_helper is inside */
return perform_glob(o, n); /* o_save_ptr_helper is inside */
}
return o_save_ptr_helper(o, n);
}
@ -2927,15 +2937,6 @@ static int done_word(o_string *word, struct parse_context *ctx)
(ctx->ctx_res_w == RES_SNTX));
return (ctx->ctx_res_w == RES_SNTX);
}
# ifdef CMD_SINGLEWORD_NOGLOB_COND
if (strcmp(word->data, "export") == 0
# if ENABLE_HUSH_LOCAL
|| strcmp(word->data, "local") == 0
# endif
) {
command->cmd_type = CMD_SINGLEWORD_NOGLOB_COND;
} else
# endif
# if ENABLE_HUSH_BASH_COMPAT
if (strcmp(word->data, "[[") == 0) {
command->cmd_type = CMD_SINGLEWORD_NOGLOB;
@ -4371,10 +4372,19 @@ static int expand_on_ifs(o_string *output, int n, const char *str)
while (1) {
int word_len = strcspn(str, G.ifs);
if (word_len) {
if (output->o_escape || !output->o_glob)
o_addQblock(output, str, word_len);
else /* protect backslashes against globbing up :) */
if (output->o_escape)
o_addqblock(output, str, word_len);
else if (!output->o_glob)
o_addblock(output, str, word_len);
else /* if (!escape && glob) */ {
/* Protect backslashes against globbing up :)
* Example: "v='\*'; echo b$v"
*/
o_addblock_duplicate_backslash(output, str, word_len);
/*/ Why can't we do it easier? */
/*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
/*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
}
str += word_len;
}
if (!*str) /* EOL - do not finalize word */
@ -4594,8 +4604,9 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
if (exp_op == *exp_word) /* ## or %% */
exp_word++;
//TODO: avoid xstrdup unless needed
// (see HACK ALERT below)
// (see HACK ALERT below for an example)
val = to_be_freed = xstrdup(val);
//TODO: fix expansion rules:
exp_exp_word = expand_pseudo_dquoted(exp_word);
if (exp_exp_word)
exp_word = exp_exp_word;
@ -4613,10 +4624,26 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
}
#if ENABLE_HUSH_BASH_COMPAT
else if (exp_op == '/' || exp_op == '\\') {
/* It's ${var/[/]pattern[/repl]} thing.
* Note that in encoded form it has TWO parts:
* var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
*/
/* Empty variable always gives nothing: */
// "v=''; echo ${v/*/w}" prints ""
// "v=''; echo ${v/*/w}" prints "", not "w"
if (val && val[0]) {
/* It's ${var/[/]pattern[/repl]} thing */
/*
* Pattern is taken literally, while
* repl should be de-backslased and globbed
* by the usual expansion rules:
* >az; >bz;
* v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
* v='a bz'; echo "${v/a*z/\z}" prints "\z"
* v='a bz'; echo ${v/a*z/a*z} prints "az"
* v='a bz'; echo ${v/a*z/\z} prints "z"
* (note that a*z _pattern_ is never globbed!)
*/
//TODO: fix expansion rules:
char *pattern, *repl, *t;
pattern = expand_pseudo_dquoted(exp_word);
if (!pattern)
@ -4772,7 +4799,6 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
char first_ch;
int i;
char *to_be_freed = NULL;
const char *val = NULL;
#if ENABLE_HUSH_TICK
@ -4795,10 +4821,11 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
switch (first_ch & 0x7f) {
/* Highest bit in first_ch indicates that var is double-quoted */
case '*':
case '@':
i = 1;
if (!G.global_argv[i])
case '@': {
int i;
if (!G.global_argv[1])
break;
i = 1;
ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
smallint sv = output->o_escape;
@ -4839,6 +4866,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
}
}
break;
}
case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
/* "Empty variable", used to make "" etc to not disappear */
arg++;
@ -4984,41 +5012,6 @@ static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
}
#endif
#ifdef CMD_SINGLEWORD_NOGLOB_COND
static char **expand_strvec_to_strvec_singleword_noglob_cond(char **argv)
{
int n;
char **list;
char **v;
o_string output = NULL_O_STRING;
n = 0;
v = argv;
while (*v) {
int is_var = is_well_formed_var_name(*v, '=');
/* is_var * 0x80: singleword expansion for vars */
n = expand_vars_to_list(&output, n, *v, is_var * 0x80);
/* Subtle! expand_vars_to_list did not glob last word yet.
* It does this only when fed with further data.
* Therefore we set globbing flags AFTER it, not before:
*/
/* if it is not recognizably abc=...; then: */
output.o_escape = !is_var; /* protect against globbing for "$var" */
/* (unquoted $var will temporarily switch it off) */
output.o_glob = !is_var; /* and indeed do globbing */
v++;
}
debug_print_list("expand_cond", &output, n);
/* output.data (malloced in one block) gets returned in "list" */
list = o_finalize_list(&output, n);
debug_print_strings("expand_cond[1]", list);
return list;
}
#endif
/* Used for expansion of right hand of assignments */
/* NB: should NOT do globbing!
* "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*" */
@ -6566,11 +6559,6 @@ static NOINLINE int run_pipe(struct pipe *pi)
else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
}
#endif
#ifdef CMD_SINGLEWORD_NOGLOB_COND
else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB_COND) {
argv_expanded = expand_strvec_to_strvec_singleword_noglob_cond(argv + command->assignment_cnt);
}
#endif
else {
argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);

18
shell/hush_test/hush-glob/glob2.right Normal file
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@ -0,0 +1,18 @@
Expected Actual
Z\* : Z\*
Z* : Z*
Z\f : Z\f
Z\* : Z\*
Z\z : Z\z
Zz : Zz
Z\z : Z\z
Z\z : Z\z
Z\ : Z\
Z\ : Z\
Z\f Zf : Z\f Zf
Z\f Zf : Z\f Zf
Done: 0

27
shell/hush_test/hush-glob/glob2.tests Executable file
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@ -0,0 +1,27 @@
# This test demonstrates that in unquoted $v, backslashes expand by this rule:
# \z -> \\\z; \<eol> -> \\<eol> (for any z, special or not),
# and subsequently globbing converts \\ to \ and treats \z as literal z
# even if it is a special char.
>'Zf'
>'Z\f'
echo 'Expected' 'Actual'
v='\*'; echo 'Z\* :' Z$v
echo 'Z* :' Z\*
echo 'Z\f :' Z\\*
echo 'Z\* :' Z\\\* # NB! only this matches Z$v output
echo
v='\z'; echo 'Z\z :' Z$v
echo 'Zz :' Z\z
echo 'Z\z :' Z\\z
echo 'Z\z :' Z\\\z
echo
v='\'; echo 'Z\ :' Z$v
echo 'Z\ :' Z\\
echo
v='*'; echo 'Z\f Zf :' Z$v
echo 'Z\f Zf :' Z*
echo
rm 'Z\f' 'Zf'
echo Done: $?

25
shell/hush_test/hush-vars/var_bash4.right
View File

@ -1,23 +1,40 @@
Source: a*b\*c
Replace str: _\\_\z_
Pattern: single backslash and star: "replace literal star"
In assignment: a_\_z_b\*c
Unquoted: a_\_z_b\*c
Unquoted =: a_\_z_b\*c
Quoted: a_\_\z_b\*c
Quoted =: a_\_\z_b\*c
Pattern: double backslash and star: "replace backslash and everything after it"
In assignment: a*b_\_z_
Unquoted: a*b_\_z_
Unquoted =: a*b_\_z_
Quoted: a*b_\_\z_
Quoted =: a*b_\_\z_
Source: a\bc
Replace str: _\\_\z_
Pattern: single backslash and b: "replace b"
In assignment: a\_\_z_c
Unquoted: a\_\_z_c
Unquoted =: a\_\_z_c
Quoted: a\_\_\z_c
Quoted =: a\_\_\z_c
Pattern: double backslash and b: "replace backslash and b"
In assignment: a_\_z_c
Unquoted: a_\_z_c
Unquoted =: a_\_z_c
Quoted: a_\_\z_c
Quoted =: a_\_\z_c
Source: a\bc
Replace str: _\\_\z_ (as variable $s)
Pattern: single backslash and b: "replace b"
Unquoted: a\_\\_\z_c
Unquoted =: a\_\\_\z_c
Quoted: a\_\\_\z_c
Quoted =: a\_\\_\z_c
Pattern: double backslash and b: "replace backslash and b"
Unquoted: a_\\_\z_c
Unquoted =: a_\\_\z_c
Quoted: a_\\_\z_c
Quoted =: a_\\_\z_c
Done: 0

52
shell/hush_test/hush-vars/var_bash4.tests
View File

@ -6,23 +6,30 @@
# even in quotes.
#
# bash4 (and probably bash3 too): "Quoted:" results are different from
# unquoted and assignment expansions - they have a backslash before z.
# unquoted expansions - they have a backslash before z.
#
# The difference only exists if repl is a literal. If it is a variable:
# ${v/.../$s}, then all backslashes are preserved in both cases.
v='a*b\*c'
echo 'Source: ' "$v"
echo 'Replace str: ' '_\\_\z_'
echo 'Pattern: ' 'single backslash and star: "replace literal star"'
r=${v/\*/_\\_\z_}
echo 'In assignment:' "$r"
echo 'Unquoted: ' ${v/\*/_\\_\z_}
r=${v/\*/_\\_\z_}
echo 'Unquoted =: ' "$r"
echo 'Quoted: ' "${v/\*/_\\_\z_}"
r="${v/\*/_\\_\z_}"
echo 'Quoted =: ' "$r"
echo 'Pattern: ' 'double backslash and star: "replace backslash and everything after it"'
r=${v/\\*/_\\_\z_}
echo 'In assignment:' "$r"
echo 'Unquoted: ' ${v/\\*/_\\_\z_}
r=${v/\\*/_\\_\z_}
echo 'Unquoted =: ' "$r"
echo 'Quoted: ' "${v/\\*/_\\_\z_}"
r="${v/\\*/_\\_\z_}"
echo 'Quoted =: ' "$r"
echo
@ -31,16 +38,43 @@ echo 'Source: ' "$v"
echo 'Replace str: ' '_\\_\z_'
echo 'Pattern: ' 'single backslash and b: "replace b"'
r=${v/\b/_\\_\z_}
echo 'In assignment:' "$r"
echo 'Unquoted: ' ${v/\b/_\\_\z_}
r=${v/\b/_\\_\z_}
echo 'Unquoted =: ' "$r"
echo 'Quoted: ' "${v/\b/_\\_\z_}"
r="${v/\b/_\\_\z_}"
echo 'Quoted =: ' "$r"
echo 'Pattern: ' 'double backslash and b: "replace backslash and b"'
r=${v/\\b/_\\_\z_}
echo 'In assignment:' "$r"
echo 'Unquoted: ' ${v/\\b/_\\_\z_}
r=${v/\\b/_\\_\z_}
echo 'Unquoted =: ' "$r"
echo 'Quoted: ' "${v/\\b/_\\_\z_}"
r="${v/\\b/_\\_\z_}"
echo 'Quoted =: ' "$r"
echo
v='a\bc'
s='_\\_\z_'
echo 'Source: ' "$v"
echo 'Replace str: ' "$s" '(as variable $s)'
echo 'Pattern: ' 'single backslash and b: "replace b"'
echo 'Unquoted: ' ${v/\b/$s}
r=${v/\b/$s}
echo 'Unquoted =: ' "$r"
echo 'Quoted: ' "${v/\b/$s}"
r="${v/\b/$s}"
echo 'Quoted =: ' "$r"
echo 'Pattern: ' 'double backslash and b: "replace backslash and b"'
echo 'Unquoted: ' ${v/\\b/$s}
r=${v/\\b/$s}
echo 'Unquoted =: ' "$r"
echo 'Quoted: ' "${v/\\b/$s}"
r="${v/\\b/$s}"
echo 'Quoted =: ' "$r"
echo