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authorDenys Vlasenko2010-09-06 10:26:37 +0200
committerDenys Vlasenko2010-09-06 10:26:37 +0200
commitc49d2d97939d77be3d1f3bbbbf9db30a55771c15 (patch)
tree8cf0a9ad8fd7e0d9762684fef0a7a5a4f7d43859 /shell/hush.c
parentd383b49aefecea99e5bfb2f9eb2956f1c6c013e1 (diff)
downloadbusybox-c49d2d97939d77be3d1f3bbbbf9db30a55771c15.zip
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hush: fix globbing+backslashes in unquoted $var expansion
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Diffstat (limited to 'shell/hush.c')
-rw-r--r--shell/hush.c134
1 files changed, 61 insertions, 73 deletions
diff --git a/shell/hush.c b/shell/hush.c
index 2a4e80b..ef46372 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -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) {
+ len--;
o_addchr(o, *str);
- if (*str == '\\') {
+ if (*str++ == '\\') {
+ /* \z -> \\\z; \<eol> -> \\<eol> */
o_addchr(o, '\\');
+ if (len) {
+ len--;
+ o_addchr(o, '\\');
+ o_addchr(o, *str++);
+ }
}
- str++;
- len--;
}
}
@@ -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*" */
@@ -6567,11 +6560,6 @@ static NOINLINE int run_pipe(struct pipe *pi)
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);
}