**/
/*
- * This module allows to filter value lists based on Perl-compatible regular
- * expressions.
+ * This module allows to filter and rewrite value lists based on
+ * Perl-compatible regular expressions.
*/
#include "collectd.h"
#include "plugin.h"
#include "common.h"
+#include "utils_subst.h"
+
#include <pcre.h>
#define log_err(...) ERROR ("filter_pcre: " __VA_ARGS__)
*/
typedef struct {
+ /* regular expression */
pcre *re;
+ const char *re_str;
+
+ /* extra information from studying the pattern */
pcre_extra *extra;
+
+ /* replacment text for string substitution */
+ const char *replacement;
} c_pcre_t;
#define C_PCRE_INIT(regex) do { \
- (regex).re = NULL; \
- (regex).extra = NULL; \
+ (regex).re = NULL; \
+ (regex).re_str = NULL; \
+ (regex).extra = NULL; \
+ (regex).replacement = NULL; \
} while (0)
#define C_PCRE_FREE(regex) do { \
pcre_free ((regex).re); \
+ free ((void *)(regex).re_str); \
pcre_free ((regex).extra); \
+ free ((void *)(regex).replacement); \
C_PCRE_INIT (regex); \
} while (0)
int action;
} regex_t;
+typedef struct {
+ int vec[30];
+ int status;
+} ovec_t;
+
+typedef struct {
+ ovec_t host;
+ ovec_t plugin;
+ ovec_t plugin_instance;
+ ovec_t type;
+ ovec_t type_instance;
+} ovectors_t;
+
/*
* private variables
*/
*/
/* returns true if string matches the regular expression */
-static int c_pcre_match (c_pcre_t *re, const char *string)
+static int c_pcre_match (c_pcre_t *re, const char *string, ovec_t *ovec)
{
- int status;
- int ovector[30];
-
- if (NULL == re)
+ if ((NULL == re) || (NULL == re->re))
return 1;
if (NULL == string)
string = "";
- status = pcre_exec (re->re,
+ ovec->status = pcre_exec (re->re,
/* extra = */ re->extra,
/* subject = */ string,
/* length = */ strlen (string),
/* startoffset = */ 0,
/* options = */ 0,
- /* ovector = */ ovector,
- /* ovecsize = */ STATIC_ARRAY_SIZE (ovector));
+ /* ovector = */ ovec->vec,
+ /* ovecsize = */ STATIC_ARRAY_SIZE (ovec->vec));
- if (0 <= status)
+ if (0 <= ovec->status)
return 1;
- if (PCRE_ERROR_NOMATCH != status)
+ if (PCRE_ERROR_NOMATCH != ovec->status)
log_err ("PCRE matching of string \"%s\" failed with status %d",
- string, status);
+ string, ovec->status);
return 0;
} /* c_pcre_match */
+static int c_pcre_subst (c_pcre_t *re, char *string, size_t strlen,
+ ovec_t *ovec)
+{
+ char buffer[strlen];
+
+ if ((NULL == re) || (NULL == re->replacement))
+ return 0;
+
+ assert (0 <= ovec->status);
+
+ if (NULL == subst (buffer, sizeof (buffer), string,
+ ovec->vec[0], ovec->vec[1], re->replacement)) {
+ log_err ("Substitution in string \"%s\" (using regex \"%s\" and "
+ "replacement string \"%s\") failed.",
+ string, re->re_str, re->replacement);
+ return -1;
+ }
+
+ sstrncpy (string, buffer, strlen);
+ return 0;
+} /* c_pcre_subst */
+
static regex_t *regex_new (void)
{
regex_t *re;
+ regex_t *temp;
- ++regexes_num;
- regexes = (regex_t *)realloc (regexes, regexes_num * sizeof (*regexes));
- if (NULL == regexes) {
+ temp = (regex_t *) realloc (regexes, (regexes_num + 1)
+ * sizeof (*regexes));
+ if (NULL == temp) {
log_err ("Out of memory.");
- exit (5);
+ return NULL;
}
+ regexes = temp;
+ regexes_num++;
re = regexes + (regexes_num - 1);
} /* regex_delete */
/* returns true if the value list matches the regular expression */
-static int regex_match (regex_t *re, value_list_t *vl)
+static int regex_match (regex_t *re, value_list_t *vl, ovectors_t *ovectors)
{
int matches = 0;
if (NULL == re)
return 1;
- if ((NULL == re->host.re) || c_pcre_match (&re->host, vl->host))
+ if (c_pcre_match (&re->host, vl->host, &ovectors->host))
++matches;
- if ((NULL == re->plugin.re) || c_pcre_match (&re->plugin, vl->plugin))
+ if (c_pcre_match (&re->plugin, vl->plugin, &ovectors->plugin))
++matches;
- if ((NULL == re->plugin_instance.re)
- || c_pcre_match (&re->plugin_instance, vl->plugin_instance))
+ if (c_pcre_match (&re->plugin_instance, vl->plugin_instance,
+ &ovectors->plugin_instance))
++matches;
- if ((NULL == re->type.re) || c_pcre_match (&re->type, vl->type))
+ if (c_pcre_match (&re->type, vl->type, &ovectors->type))
++matches;
- if ((NULL == re->type_instance.re)
- || c_pcre_match (&re->type_instance, vl->type_instance))
+ if (c_pcre_match (&re->type_instance, vl->type_instance,
+ &ovectors->type_instance))
++matches;
if (5 == matches)
return 0;
} /* regex_match */
+static int regex_subst (regex_t *re, value_list_t *vl, ovectors_t *ovectors)
+{
+ if (NULL == re)
+ return 0;
+
+ c_pcre_subst (&re->host, vl->host, sizeof (vl->host),
+ &ovectors->host);
+ c_pcre_subst (&re->plugin, vl->plugin, sizeof (vl->plugin),
+ &ovectors->plugin);
+ c_pcre_subst (&re->plugin_instance, vl->plugin_instance,
+ sizeof (vl->plugin_instance), &ovectors->plugin_instance);
+ c_pcre_subst (&re->type, vl->type, sizeof (vl->type),
+ &ovectors->type);
+ c_pcre_subst (&re->type_instance, vl->type_instance,
+ sizeof (vl->type_instance), &ovectors->type_instance);
+ return 0;
+} /* regex_subst */
+
/*
* interface to collectd
*/
{
int i;
+ ovectors_t ovectors;
+
for (i = 0; i < regexes_num; ++i)
- if (regex_match (regexes + i, vl))
+ if (regex_match (regexes + i, vl, &ovectors)) {
+ regex_subst (regexes + i, vl, &ovectors);
return regexes[i].action;
+ }
return 0;
} /* c_pcre_filter */
return 1;
}
+ re->re_str = sstrdup (pattern);
+
re->extra = pcre_study (re->re,
/* options = */ 0,
/* errptr = */ &errptr);
return 0;
} /* config_set_regex */
+static int config_set_replacement (c_pcre_t *re, oconfig_item_t *ci)
+{
+ if ((0 != ci->children_num) || (1 != ci->values_num)
+ || (OCONFIG_TYPE_STRING != ci->values[0].type)) {
+ log_err ("<RegEx>: %s expects a single string argument.", ci->key);
+ return 1;
+ }
+
+ if (NULL == re->re) {
+ log_err ("<RegEx>: %s without an appropriate regex (%s) "
+ "is not allowed.", ci->key, ci->key + strlen ("Substitute"));
+ return 1;
+ }
+
+ re->replacement = sstrdup (ci->values[0].value.string);
+ return 0;
+} /* config_set_replacement */
+
static int config_set_action (int *action, oconfig_item_t *ci)
{
const char *action_str;
}
re = regex_new ();
+ if (NULL == re)
+ return -1;
for (i = 0; i < ci->children_num; ++i) {
oconfig_item_t *c = ci->children + i;
status = config_set_regex (&re->type_instance, c);
else if (0 == strcasecmp (c->key, "Action"))
status = config_set_action (&re->action, c);
+ else if (0 == strcasecmp (c->key, "SubstituteHost"))
+ status = config_set_replacement (&re->host, c);
+ else if (0 == strcasecmp (c->key, "SubstitutePlugin"))
+ status = config_set_replacement (&re->plugin, c);
+ else if (0 == strcasecmp (c->key, "SubstitutePluginInstance"))
+ status = config_set_replacement (&re->plugin_instance, c);
+ else if (0 == strcasecmp (c->key, "SubstituteType"))
+ status = config_set_replacement (&re->type, c);
+ else if (0 == strcasecmp (c->key, "SubstituteTypeInstance"))
+ status = config_set_replacement (&re->type_instance, c);
else
log_warn ("<RegEx>: Ignoring unknown config key \"%s\".", c->key);
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