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Subject[PATCH] TOMOYO: Add recursive directory matching operator support.
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Date
[PATCH] TOMOYO: Add recursive directory matching operator support.

This patch introduces new operator /\{dir\}/ which matches
'/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/ /dir/dir/dir/ ).
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
security/tomoyo/common.c | 200 ++++++++++++++++++++++++++++-------------------
security/tomoyo/common.h | 4
2 files changed, 121 insertions(+), 83 deletions(-)
--- security-testing-2.6.orig/security/tomoyo/common.c
+++ security-testing-2.6/security/tomoyo/common.c
@@ -187,6 +187,8 @@ bool tomoyo_is_correct_path(const char *
const s8 pattern_type, const s8 end_type,
const char *function)
{
+ const char *const start = filename;
+ bool in_repetition = false;
bool contains_pattern = false;
unsigned char c;
unsigned char d;
@@ -212,9 +214,13 @@ bool tomoyo_is_correct_path(const char *
if (c == '/')
goto out;
}
- while ((c = *filename++) != '\0') {
+ while (1) {
+ c = *filename++;
+ if (!c)
+ break;
if (c == '\\') {
- switch ((c = *filename++)) {
+ c = *filename++;
+ switch (c) {
case '\\': /* "\\" */
continue;
case '$': /* "\$" */
@@ -231,6 +237,22 @@ bool tomoyo_is_correct_path(const char *
break; /* Must not contain pattern */
contains_pattern = true;
continue;
+ case '{': /* "/\{" */
+ if (filename - 3 < start ||
+ *(filename - 3) != '/')
+ break;
+ if (pattern_type == -1)
+ break; /* Must not contain pattern */
+ contains_pattern = true;
+ in_repetition = true;
+ continue;
+ case '}': /* "\}/" */
+ if (*filename != '/')
+ break;
+ if (!in_repetition)
+ break;
+ in_repetition = false;
+ continue;
case '0': /* "\ooo" */
case '1':
case '2':
@@ -246,6 +268,8 @@ bool tomoyo_is_correct_path(const char *
continue; /* pattern is not \000 */
}
goto out;
+ } else if (in_repetition && c == '/') {
+ goto out;
} else if (tomoyo_is_invalid(c)) {
goto out;
}
@@ -254,6 +278,8 @@ bool tomoyo_is_correct_path(const char *
if (!contains_pattern)
goto out;
}
+ if (in_repetition)
+ goto out;
return true;
out:
printk(KERN_DEBUG "%s: Invalid pathname '%s'\n", function,
@@ -360,33 +386,6 @@ struct tomoyo_domain_info *tomoyo_find_d
}

/**
- * tomoyo_path_depth - Evaluate the number of '/' in a string.
- *
- * @pathname: The string to evaluate.
- *
- * Returns path depth of the string.
- *
- * I score 2 for each of the '/' in the @pathname
- * and score 1 if the @pathname ends with '/'.
- */
-static int tomoyo_path_depth(const char *pathname)
-{
- int i = 0;
-
- if (pathname) {
- const char *ep = pathname + strlen(pathname);
- if (pathname < ep--) {
- if (*ep != '/')
- i++;
- while (pathname <= ep)
- if (*ep-- == '/')
- i += 2;
- }
- }
- return i;
-}
-
-/**
* tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
*
* @filename: The string to evaluate.
@@ -444,11 +443,10 @@ void tomoyo_fill_path_info(struct tomoyo
ptr->is_dir = len && (name[len - 1] == '/');
ptr->is_patterned = (ptr->const_len < len);
ptr->hash = full_name_hash(name, len);
- ptr->depth = tomoyo_path_depth(name);
}

/**
- * tomoyo_file_matches_to_pattern2 - Pattern matching without '/' character
+ * tomoyo_file_matches_pattern2 - Pattern matching without '/' character
* and "\-" pattern.
*
* @filename: The start of string to check.
@@ -458,10 +456,10 @@ void tomoyo_fill_path_info(struct tomoyo
*
* Returns true if @filename matches @pattern, false otherwise.
*/
-static bool tomoyo_file_matches_to_pattern2(const char *filename,
- const char *filename_end,
- const char *pattern,
- const char *pattern_end)
+static bool tomoyo_file_matches_pattern2(const char *filename,
+ const char *filename_end,
+ const char *pattern,
+ const char *pattern_end)
{
while (filename < filename_end && pattern < pattern_end) {
char c;
@@ -519,7 +517,7 @@ static bool tomoyo_file_matches_to_patte
case '*':
case '@':
for (i = 0; i <= filename_end - filename; i++) {
- if (tomoyo_file_matches_to_pattern2(
+ if (tomoyo_file_matches_pattern2(
filename + i, filename_end,
pattern + 1, pattern_end))
return true;
@@ -550,7 +548,7 @@ static bool tomoyo_file_matches_to_patte
j++;
}
for (i = 1; i <= j; i++) {
- if (tomoyo_file_matches_to_pattern2(
+ if (tomoyo_file_matches_pattern2(
filename + i, filename_end,
pattern + 1, pattern_end))
return true;
@@ -567,7 +565,7 @@ static bool tomoyo_file_matches_to_patte
}

/**
- * tomoyo_file_matches_to_pattern - Pattern matching without without '/' character.
+ * tomoyo_file_matches_pattern - Pattern matching without without '/' character.
*
* @filename: The start of string to check.
* @filename_end: The end of string to check.
@@ -576,7 +574,7 @@ static bool tomoyo_file_matches_to_patte
*
* Returns true if @filename matches @pattern, false otherwise.
*/
-static bool tomoyo_file_matches_to_pattern(const char *filename,
+static bool tomoyo_file_matches_pattern(const char *filename,
const char *filename_end,
const char *pattern,
const char *pattern_end)
@@ -589,10 +587,10 @@ static bool tomoyo_file_matches_to_patte
/* Split at "\-" pattern. */
if (*pattern++ != '\\' || *pattern++ != '-')
continue;
- result = tomoyo_file_matches_to_pattern2(filename,
- filename_end,
- pattern_start,
- pattern - 2);
+ result = tomoyo_file_matches_pattern2(filename,
+ filename_end,
+ pattern_start,
+ pattern - 2);
if (first)
result = !result;
if (result)
@@ -600,13 +598,79 @@ static bool tomoyo_file_matches_to_patte
first = false;
pattern_start = pattern;
}
- result = tomoyo_file_matches_to_pattern2(filename, filename_end,
- pattern_start, pattern_end);
+ result = tomoyo_file_matches_pattern2(filename, filename_end,
+ pattern_start, pattern_end);
return first ? result : !result;
}

/**
+ * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
+ *
+ * @f: The start of string to check.
+ * @p: The start of pattern to compare.
+ *
+ * Returns true if @f matches @p, false otherwise.
+ */
+static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
+{
+ const char *f_delimiter;
+ const char *p_delimiter;
+
+ while (*f && *p) {
+ f_delimiter = strchr(f, '/');
+ if (!f_delimiter)
+ f_delimiter = f + strlen(f);
+ p_delimiter = strchr(p, '/');
+ if (!p_delimiter)
+ p_delimiter = p + strlen(p);
+ if (*p == '\\' && *(p + 1) == '{')
+ goto recursive;
+ if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
+ p_delimiter))
+ return false;
+ f = f_delimiter;
+ if (*f)
+ f++;
+ p = p_delimiter;
+ if (*p)
+ p++;
+ }
+ /* Ignore trailing "\*" and "\@" in @pattern. */
+ while (*p == '\\' &&
+ (*(p + 1) == '*' || *(p + 1) == '@'))
+ p += 2;
+ return !*f && !*p;
+ recursive:
+ /*
+ * The "\{" pattern is permitted only after '/' character.
+ * This guarantees that below "*(p - 1)" is safe.
+ * Also, the "\}" pattern is permitted only before '/' character
+ * so that "\{" + "\}" pair will not break the "\-" operator.
+ */
+ if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
+ *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
+ return false; /* Bad pattern. */
+ do {
+ /* Compare current component with pattern. */
+ if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
+ p_delimiter - 2))
+ break;
+ /* Proceed to next component. */
+ f = f_delimiter;
+ if (!*f)
+ break;
+ f++;
+ /* Continue comparison. */
+ if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
+ return true;
+ f_delimiter = strchr(f, '/');
+ } while (f_delimiter);
+ return false; /* Not matched. */
+}
+
+/**
* tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
+ *
* @filename: The filename to check.
* @pattern: The pattern to compare.
*
@@ -615,24 +679,24 @@ static bool tomoyo_file_matches_to_patte
* The following patterns are available.
* \\ \ itself.
* \ooo Octal representation of a byte.
- * \* More than or equals to 0 character other than '/'.
- * \@ More than or equals to 0 character other than '/' or '.'.
+ * \* Zero or more repetitions of characters other than '/'.
+ * \@ Zero or more repetitions of characters other than '/' or '.'.
* \? 1 byte character other than '/'.
- * \$ More than or equals to 1 decimal digit.
+ * \$ One or more repetitions of decimal digits.
* \+ 1 decimal digit.
- * \X More than or equals to 1 hexadecimal digit.
+ * \X One or more repetitions of hexadecimal digits.
* \x 1 hexadecimal digit.
- * \A More than or equals to 1 alphabet character.
+ * \A One or more repetitions of alphabet characters.
* \a 1 alphabet character.
+ *
* \- Subtraction operator.
+ *
+ * /\{dir\}/ '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
+ * /dir/dir/dir/ ).
*/
bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
const struct tomoyo_path_info *pattern)
{
- /*
- if (!filename || !pattern)
- return false;
- */
const char *f = filename->name;
const char *p = pattern->name;
const int len = pattern->const_len;
@@ -640,37 +704,15 @@ bool tomoyo_path_matches_pattern(const s
/* If @pattern doesn't contain pattern, I can use strcmp(). */
if (!pattern->is_patterned)
return !tomoyo_pathcmp(filename, pattern);
- /* Dont compare if the number of '/' differs. */
- if (filename->depth != pattern->depth)
+ /* Don't compare directory and non-directory. */
+ if (filename->is_dir != pattern->is_dir)
return false;
/* Compare the initial length without patterns. */
if (strncmp(f, p, len))
return false;
f += len;
p += len;
- /* Main loop. Compare each directory component. */
- while (*f && *p) {
- const char *f_delimiter = strchr(f, '/');
- const char *p_delimiter = strchr(p, '/');
- if (!f_delimiter)
- f_delimiter = f + strlen(f);
- if (!p_delimiter)
- p_delimiter = p + strlen(p);
- if (!tomoyo_file_matches_to_pattern(f, f_delimiter,
- p, p_delimiter))
- return false;
- f = f_delimiter;
- if (*f)
- f++;
- p = p_delimiter;
- if (*p)
- p++;
- }
- /* Ignore trailing "\*" and "\@" in @pattern. */
- while (*p == '\\' &&
- (*(p + 1) == '*' || *(p + 1) == '@'))
- p += 2;
- return !*f && !*p;
+ return tomoyo_path_matches_pattern2(f, p);
}

/**
--- security-testing-2.6.orig/security/tomoyo/common.h
+++ security-testing-2.6/security/tomoyo/common.h
@@ -56,9 +56,6 @@ struct tomoyo_page_buffer {
* (5) "is_patterned" is a bool which is true if "name" contains wildcard
* characters, false otherwise. This allows TOMOYO to use "hash" and
* strcmp() for string comparison if "is_patterned" is false.
- * (6) "depth" is calculated using the number of "/" characters in "name".
- * This allows TOMOYO to avoid comparing two pathnames which never match
- * (e.g. whether "/var/www/html/index.html" matches "/tmp/sh-thd-\$").
*/
struct tomoyo_path_info {
const char *name;
@@ -66,7 +63,6 @@ struct tomoyo_path_info {
u16 const_len; /* = tomoyo_const_part_length(name) */
bool is_dir; /* = tomoyo_strendswith(name, "/") */
bool is_patterned; /* = tomoyo_path_contains_pattern(name) */
- u16 depth; /* = tomoyo_path_depth(name) */
};

/*

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