[apparmor] [PATCH] [parsers] allow for nested alternations expressions

[Steve Beattie]

On Mon, Nov 04, 2013 at 05:28:22PM -0800, John Johansen wrote:
> On 11/04/2013 04:34 PM, Steve Beattie wrote:
> > Well, part of the slowdown was me writing some unit tests for that
> > function. Here's the patch that does that:
[SNIP]
> > +	//MY_REGEX_TEST("\\", "\\", ePatternBasic);
> > +	MY_REGEX_TEST("\\\\", "\\\\", ePatternBasic);
> > +	//MY_REGEX_TEST("\\blort", "\\blort", ePatternBasic);
> > +	MY_REGEX_TEST("\\\\blort", "\\\\blort", ePatternBasic);
> > +	//MY_REGEX_TEST("blort\\", "blort\\", ePatternBasic);
> why are these 3 commented out?

Ah, right, I'd forgotten about these. They're commented out
because as-is, they fail; however I wasn't sure if that was the
correct expected output. Basically, what happens is that if whatever
follows isn't expecting an escape character, then the escaping '\' is
dropped. Thus, the current behavior is that '\\' becomes '' and both
'\\blort' and 'blort\\' become 'blort'.

The question is, is this a bug? I think so... but I'm willing to hear
countering arguments.

Attached is an updated patch that uncomments them out, adds the expected
and resultant strings to the testcase output, and frees the strings
allocated within the testcase.

Signed-off-by: Steve Beattie <steve at nxnw.org>
---
 parser/parser_regex.c |  107 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)

Index: b/parser/parser_regex.c
===================================================================
--- a/parser/parser_regex.c
+++ b/parser/parser_regex.c
@@ -1262,6 +1262,109 @@ static int test_filter_slashes(void)
 	return rc;
 }
 
+#define MY_REGEX_TEST(input, expected_str, expected_type)						\
+	do {												\
+		char tbuf[PATH_MAX + 3];								\
+		char *test_string;									\
+		char* output_string = NULL;							\
+		pattern_t ptype;									\
+		int pos;										\
+													\
+		test_string = strdup((input)); 								\
+		ptype = convert_aaregex_to_pcre(test_string, 0, tbuf, PATH_MAX + 3, &pos);		\
+		asprintf(&output_string, "simple regex conversion for '%s'\texpected = '%s'\tresult = '%s'", \
+				(input), expected_str, tbuf);						\
+		MY_TEST(strcmp(tbuf, (expected_str)) == 0, output_string);				\
+		MY_TEST(ptype == (expected_type), "simple regex conversion type check for '" input "'"); \
+		free(test_string); 									\
+	}												\
+	while (0)
+
+#define MY_REGEX_FAIL_TEST(input)						\
+	do {												\
+		char tbuf[PATH_MAX + 3];								\
+		char *test_string;									\
+		pattern_t ptype;									\
+		int pos;										\
+													\
+		test_string = strdup((input)); 								\
+		ptype = convert_aaregex_to_pcre(test_string, 0, tbuf, PATH_MAX + 3, &pos);		\
+		MY_TEST(ptype == ePatternInvalid, "simple regex conversion invalid type check for '" input "'"); \
+		free(test_string); 									\
+	}												\
+	while (0)
+
+static int test_aaregex_to_pcre(void)
+{
+	int rc = 0;
+
+	MY_REGEX_TEST("/most/basic/test", "/most/basic/test", ePatternBasic);
+
+	MY_REGEX_TEST("\\", "\\", ePatternBasic);
+	MY_REGEX_TEST("\\\\", "\\\\", ePatternBasic);
+	MY_REGEX_TEST("\\blort", "\\blort", ePatternBasic);
+	MY_REGEX_TEST("\\\\blort", "\\\\blort", ePatternBasic);
+	MY_REGEX_TEST("blort\\", "blort\\", ePatternBasic);
+	MY_REGEX_TEST("blort\\\\", "blort\\\\", ePatternBasic);
+	MY_REGEX_TEST("*", "[^/\\x00]*", ePatternRegex);
+	MY_REGEX_TEST("blort*", "blort[^/\\x00]*", ePatternRegex);
+	MY_REGEX_TEST("*blort", "[^/\\x00]*blort", ePatternRegex);
+	MY_REGEX_TEST("\\*", "\\*", ePatternBasic);
+	MY_REGEX_TEST("blort\\*", "blort\\*", ePatternBasic);
+	MY_REGEX_TEST("\\*blort", "\\*blort", ePatternBasic);
+
+	/* simple quoting */
+	MY_REGEX_TEST("\\[", "\\[", ePatternBasic);
+	MY_REGEX_TEST("\\]", "\\]", ePatternBasic);
+	MY_REGEX_TEST("\\?", "?", ePatternBasic);
+	MY_REGEX_TEST("\\{", "\\{", ePatternBasic);
+	MY_REGEX_TEST("\\}", "\\}", ePatternBasic);
+	MY_REGEX_TEST("\\,", ",", ePatternBasic);
+	MY_REGEX_TEST("^", "\\^", ePatternBasic);
+	MY_REGEX_TEST("$", "\\$", ePatternBasic);
+	MY_REGEX_TEST(".", "\\.", ePatternBasic);
+	MY_REGEX_TEST("+", "\\+", ePatternBasic);
+	MY_REGEX_TEST("|", "\\|", ePatternBasic);
+	MY_REGEX_TEST("(", "\\(", ePatternBasic);
+	MY_REGEX_TEST(")", "\\)", ePatternBasic);
+	MY_REGEX_TEST("\\^", "\\^", ePatternBasic);
+	MY_REGEX_TEST("\\$", "\\$", ePatternBasic);
+	MY_REGEX_TEST("\\.", "\\.", ePatternBasic);
+	MY_REGEX_TEST("\\+", "\\+", ePatternBasic);
+	MY_REGEX_TEST("\\|", "\\|", ePatternBasic);
+	MY_REGEX_TEST("\\(", "\\(", ePatternBasic);
+	MY_REGEX_TEST("\\)", "\\)", ePatternBasic);
+
+	/* simple character class tests */
+	MY_REGEX_TEST("[blort]", "[blort]", ePatternRegex);
+	MY_REGEX_FAIL_TEST("[blort");
+	MY_REGEX_FAIL_TEST("b[lort");
+	MY_REGEX_FAIL_TEST("blort[");
+	MY_REGEX_FAIL_TEST("blort]");
+	MY_REGEX_FAIL_TEST("blo]rt");
+	MY_REGEX_FAIL_TEST("]blort");
+
+	/* simple alternation tests */
+	MY_REGEX_TEST("{alpha,beta}", "(alpha|beta)", ePatternRegex);
+	MY_REGEX_TEST("baz{alpha,beta}blort", "baz(alpha|beta)blort", ePatternRegex);
+	MY_REGEX_FAIL_TEST("{beta}");
+	MY_REGEX_FAIL_TEST("biz{beta");
+	MY_REGEX_FAIL_TEST("biz}beta");
+	MY_REGEX_FAIL_TEST("biz{be,ta");
+	MY_REGEX_FAIL_TEST("biz,be}ta");
+	MY_REGEX_FAIL_TEST("biz{}beta");
+
+	/* nested alternations */
+	MY_REGEX_TEST("{{alpha,blort,nested},beta}", "((alpha|blort|nested)|beta)", ePatternRegex);
+	MY_REGEX_FAIL_TEST("{{alpha,blort,nested}beta}");
+	MY_REGEX_TEST("{{alpha,{blort,nested}},beta}", "((alpha|(blort|nested))|beta)", ePatternRegex);
+	MY_REGEX_TEST("{{alpha,alpha{blort,nested}}beta,beta}", "((alpha|alpha(blort|nested))beta|beta)", ePatternRegex);
+	MY_REGEX_TEST("{{alpha,alpha{blort,nested}}beta,beta}", "((alpha|alpha(blort|nested))beta|beta)", ePatternRegex);
+	MY_REGEX_TEST("{{a,b{c,d}}e,{f,{g,{h{i,j,k},l}m},n}o}", "((a|b(c|d))e|(f|(g|(h(i|j|k)|l)m)|n)o)", ePatternRegex);
+
+	return rc;
+}
+
 int main(void)
 {
 	int rc = 0;
@@ -1271,6 +1374,10 @@ int main(void)
 	if (retval != 0)
 		rc = retval;
 
+	retval = test_aaregex_to_pcre();
+	if (retval != 0)
+		rc = retval;
+
 	return rc;
 }
 #endif /* UNIT_TEST */

-- 
Steve Beattie
<sbeattie at ubuntu.com>
http://NxNW.org/~steve/
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