Le Mon, 1 Apr 2013 13:40:46 -0400,
Eric Paris <eparis@xxxxxxxxxxxxxx> a écrit :
> I feel like we talked about it... Regex ordering is a bit tricky. I
> think I hacked up a patch which added an additional tie breaker step
> with the total number of 'non-regex' type characters being used. It's
> been long lost though...
>
> Do you still have that hack around? Maybe we can see what others
> think?
I definitely have a bad memory...
I grepped my IRC logs and found this patch[0] from you at the date of
the 28th of Sept 2012.
Cheers
Laurent Bigonville
[0] http://fpaste.org/p48W/
diff --git a/libsemanage/src/semanage_store.c b/libsemanage/src/semanage_store.c
index cd7ce68..5ee3b9f 100644
--- a/libsemanage/src/semanage_store.c
+++ b/libsemanage/src/semanage_store.c
@@ -128,6 +128,7 @@ typedef struct semanage_file_context_node {
char *context;
int path_len;
int effective_len;
+ int nonmeta_len;
int type_len;
int context_len;
int meta; /* position of first meta char in path, -1 if none */
@@ -2000,6 +2001,12 @@ static int semanage_fc_compare(semanage_file_context_node_t * a,
if (b->meta < a->meta)
return 1;
+ /* total number of non meta chars? */
+ if (a->nonmeta_len < b->nonmeta_len)
+ return -1;
+ if (b->nonmeta_len < a->nonmeta_len)
+ return 1;
+
/* Check to see if either a or b have a shorter string
* length than the other. */
if (a->effective_len < b->effective_len)
@@ -2110,6 +2117,24 @@ static void semanage_fc_merge_sort(semanage_file_context_bucket_t * master)
}
}
+static int is_meta_char(char c)
+{
+ switch (c) {
+ case '.':
+ case '^':
+ case '$':
+ case '?':
+ case '*':
+ case '+':
+ case '|':
+ case '[':
+ case '(':
+ case '{':
+ return 1;
+ }
+ return 0;
+}
+
/* Compute the location of the first regular expression
* meta character in the path of the given node, if it exists.
* On return:
@@ -2127,25 +2152,15 @@ static void semanage_fc_find_meta(semanage_file_context_node_t * fc_node)
* spec_hasMetaChars in matchpathcon.c from
* libselinux-1.22. */
while (fc_node->path[c] != '\0') {
- switch (fc_node->path[c]) {
- case '.':
- case '^':
- case '$':
- case '?':
- case '*':
- case '+':
- case '|':
- case '[':
- case '(':
- case '{':
+ if (is_meta_char(fc_node->path[c])) {
fc_node->meta = c - escape_chars;
return;
- case '\\':
+ }
+ if (fc_node->path[c] == '\\') {
/* If an escape character is found,
* skip the next character. */
c++;
escape_chars++;
- break;
}
c++;
@@ -2208,7 +2223,7 @@ int semanage_fc_sort(semanage_handle_t * sh, const char *buf, size_t buf_len,
ssize_t sanity_check;
const char *line_buf, *line_end;
char *sorted_buf_pos;
- int escape_chars, just_saw_escape;
+ int escape_chars, just_saw_escape, meta_chars;
semanage_file_context_node_t *temp;
semanage_file_context_node_t *head;
@@ -2291,10 +2306,13 @@ int semanage_fc_sort(semanage_handle_t * sh, const char *buf, size_t buf_len,
temp->next = NULL;
/* Extract the regular expression from the line. */
+ meta_chars = 0;
escape_chars = 0;
just_saw_escape = 0;
start = i;
while (i < line_len && (!isspace(line_buf[i]))) {
+ if (is_meta_char(line_buf[i]))
+ meta_chars++;
if (line_buf[i] == '\\') {
if (!just_saw_escape) {
escape_chars++;
@@ -2399,6 +2417,7 @@ int semanage_fc_sort(semanage_handle_t * sh, const char *buf, size_t buf_len,
/* Initialize the data about the file context. */
temp->path_len = regex_len;
temp->effective_len = regex_len - escape_chars;
+ temp->nonmeta_len = regex_len - escape_chars - meta_chars;
temp->type_len = type_len;
temp->context_len = context_len;
semanage_fc_find_meta(temp);
