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Added removal of MySQL style comments to query canonicalization.

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Also fixed minor issues with the canonicalization regular expressions.
This commit is contained in:
Markus Makela
2016-01-08 10:43:38 +02:00
parent c067bbe34a
commit e0c84e0fe3
3 changed files with 122 additions and 39 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
query_classifier/query_classifier.cc
View File

@ -1443,6 +1443,11 @@ char* qc_get_canonical(GWBUF* querybuf)
memcpy(buffer, (uint8_t*) GWBUF_DATA(querybuf) + 5, bufsize);
buffer[bufsize] = '\0';
char* replaced = replace_quoted(buffer);
if (replaced == NULL || (querystr = remove_mysql_comments(replaced)) == NULL)
{
querystr = NULL;
}
replaced = querystr;
if (replaced == NULL || (querystr = replace_values(replaced)) == NULL)
{
querystr = NULL;

93
utils/skygw_utils.cc
View File

@ -2031,6 +2031,59 @@ void skygw_file_close(
}
}
static pcre2_code* remove_comments_re = NULL;
static const PCRE2_SPTR remove_comments_pattern = (PCRE2_SPTR)
"((--\\s.*)|(#.*))";
/**
* Remove SQL comments from the end of a string
*
* The inline comments are not removed due to the fact that they can alter the
* behavior of the query.
* @param str String to modify
* @return Pointer to new modified string or NULL if memory allocation failed
*/
char* remove_mysql_comments(const char* str)
{
static const PCRE2_SPTR replace = (PCRE2_SPTR) "";
pcre2_match_data* mdata;
size_t orig_len = strlen(str);
size_t len = orig_len;
char* output = NULL;
if (len > 0)
{
if ((output = (char*) malloc(len * sizeof (char))) &&
(mdata = pcre2_match_data_create_from_pattern(remove_comments_re, NULL)))
{
while (pcre2_substitute(remove_comments_re, (PCRE2_SPTR) str, orig_len, 0,
PCRE2_SUBSTITUTE_GLOBAL, mdata, NULL,
replace, PCRE2_ZERO_TERMINATED,
(PCRE2_UCHAR8*) output, &len) == PCRE2_ERROR_NOMEMORY)
{
char* tmp = (char*) realloc(output, len *= 2);
if (tmp == NULL)
{
free(output);
output = NULL;
break;
}
output = tmp;
}
pcre2_match_data_free(mdata);
}
else
{
free(output);
output = NULL;
}
}
else
{
output = strdup(str);
}
return output;
}
static pcre2_code* replace_values_re = NULL;
static const PCRE2_SPTR replace_values_pattern = (PCRE2_SPTR) "(?i)([-=,+*/([:space:]]|\\b|[@])"
@ -2047,8 +2100,10 @@ char* replace_values(const char* str)
pcre2_match_data* mdata;
size_t orig_len = strlen(str);
size_t len = orig_len;
char* output;
char* output = NULL;
if (len > 0)
{
if ((output = (char*) malloc(len * sizeof (char))) &&
(mdata = pcre2_match_data_create_from_pattern(replace_values_re, NULL)))
{
@ -2073,6 +2128,11 @@ char* replace_values(const char* str)
free(output);
output = NULL;
}
}
else
{
output = strdup(str);
}
return output;
}
@ -2168,7 +2228,8 @@ retblock:
}
static pcre2_code* replace_quoted_re = NULL;
static const PCRE2_SPTR replace_quoted_pattern = (PCRE2_SPTR) "(['\"])[^'\"]*(['\"])";
static const PCRE2_SPTR replace_quoted_pattern = (PCRE2_SPTR)
"(((?>(?<=[\"]))[^\"]*(?>(?=[\"])))|((?>(?<=[']))[^']*(?>(?=[']))))";
/**
* Replace everything inside single or double quotes with question marks.
@ -2177,12 +2238,13 @@ static const PCRE2_SPTR replace_quoted_pattern = (PCRE2_SPTR) "(['\"])[^'\"]*(['
*/
char* replace_quoted(const char* str)
{
static const PCRE2_SPTR replace = (PCRE2_SPTR) "$1?$2";
static const PCRE2_SPTR replace = (PCRE2_SPTR) "?";
pcre2_match_data* mdata;
size_t orig_len = strlen(str);
size_t len = orig_len;
char* output;
char* output = NULL;
if (len > 0)
{
if ((output = (char*) malloc(len * sizeof (char))) &&
(mdata = pcre2_match_data_create_from_pattern(replace_quoted_re, NULL)))
{
@ -2207,6 +2269,11 @@ char* replace_quoted(const char* str)
free(output);
output = NULL;
}
}
else
{
output = strdup(str);
}
return output;
}
@ -2310,10 +2377,18 @@ bool utils_init()
bool rval = true;
PCRE2_SIZE erroffset;
int errcore;
int errcode;
ss_info_dassert(remove_comments_re == NULL, "utils_init called multiple times");
remove_comments_re = pcre2_compile(remove_comments_pattern, PCRE2_ZERO_TERMINATED, 0, &errcode,
&erroffset, NULL);
if (remove_comments_re == NULL)
{
rval = false;
}
ss_info_dassert(replace_quoted_re == NULL, "utils_init called multiple times");
replace_quoted_re = pcre2_compile(replace_quoted_pattern, PCRE2_ZERO_TERMINATED, 0, &errcore,
replace_quoted_re = pcre2_compile(replace_quoted_pattern, PCRE2_ZERO_TERMINATED, 0, &errcode,
&erroffset, NULL);
if (replace_quoted_re == NULL)
{
@ -2321,7 +2396,7 @@ bool utils_init()
}
ss_info_dassert(replace_values_re == NULL, "utils_init called multiple times");
replace_values_re = pcre2_compile(replace_values_pattern, PCRE2_ZERO_TERMINATED, 0, &errcore,
replace_values_re = pcre2_compile(replace_values_pattern, PCRE2_ZERO_TERMINATED, 0, &errcode,
&erroffset, NULL);
if (replace_values_re == NULL)
{
@ -2336,6 +2411,8 @@ bool utils_init()
*/
void utils_end()
{
pcre2_code_free(remove_comments_re);
remove_comments_re = NULL;
pcre2_code_free(replace_quoted_re);
replace_quoted_re = NULL;
pcre2_code_free(replace_values_re);

1
utils/skygw_utils.h
View File

@ -276,6 +276,7 @@ EXTERN_C_BLOCK_BEGIN
size_t get_decimal_len(size_t s);
char* remove_mysql_comments(const char* str);
char* replace_values(const char* str);
char* replace_literal(char* haystack,
const char* needle,