1 /**
2 * collectd - src/match_regex.c
3 * Copyright (C) 2008 Sebastian Harl
4 * Copyright (C) 2008 Florian Forster
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 *
24 * Authors:
25 * Sebastian Harl <sh at tokkee.org>
26 * Florian Forster <octo at collectd.org>
27 **/
29 /*
30 * This module allows to filter and rewrite value lists based on
31 * Perl-compatible regular expressions.
32 */
34 #include "collectd.h"
36 #include "filter_chain.h"
38 #include <sys/types.h>
39 #include <regex.h>
41 #define log_err(...) ERROR ("`regex' match: " __VA_ARGS__)
42 #define log_warn(...) WARNING ("`regex' match: " __VA_ARGS__)
44 /*
45 * private data types
46 */
48 struct mr_regex_s;
49 typedef struct mr_regex_s mr_regex_t;
50 struct mr_regex_s
51 {
52 regex_t re;
53 char *re_str;
55 mr_regex_t *next;
56 };
58 struct mr_match_s;
59 typedef struct mr_match_s mr_match_t;
60 struct mr_match_s
61 {
62 mr_regex_t *host;
63 mr_regex_t *plugin;
64 mr_regex_t *plugin_instance;
65 mr_regex_t *type;
66 mr_regex_t *type_instance;
67 _Bool invert;
68 };
70 /*
71 * internal helper functions
72 */
73 static void mr_free_regex (mr_regex_t *r) /* {{{ */
74 {
75 if (r == NULL)
76 return;
78 regfree (&r->re);
79 memset (&r->re, 0, sizeof (r->re));
80 free (r->re_str);
82 if (r->next != NULL)
83 mr_free_regex (r->next);
84 } /* }}} void mr_free_regex */
86 static void mr_free_match (mr_match_t *m) /* {{{ */
87 {
88 if (m == NULL)
89 return;
91 mr_free_regex (m->host);
92 mr_free_regex (m->plugin);
93 mr_free_regex (m->plugin_instance);
94 mr_free_regex (m->type);
95 mr_free_regex (m->type_instance);
97 free (m);
98 } /* }}} void mr_free_match */
100 static int mr_match_regexen (mr_regex_t *re_head, /* {{{ */
101 const char *string)
102 {
103 if (re_head == NULL)
104 return (FC_MATCH_MATCHES);
106 for (mr_regex_t *re = re_head; re != NULL; re = re->next)
107 {
108 int status;
110 status = regexec (&re->re, string,
111 /* nmatch = */ 0, /* pmatch = */ NULL,
112 /* eflags = */ 0);
113 if (status == 0)
114 {
115 DEBUG ("regex match: Regular expression `%s' matches `%s'.",
116 re->re_str, string);
117 }
118 else
119 {
120 DEBUG ("regex match: Regular expression `%s' does not match `%s'.",
121 re->re_str, string);
122 return (FC_MATCH_NO_MATCH);
123 }
125 }
127 return (FC_MATCH_MATCHES);
128 } /* }}} int mr_match_regexen */
130 static int mr_config_add_regex (mr_regex_t **re_head, /* {{{ */
131 oconfig_item_t *ci)
132 {
133 mr_regex_t *re;
134 int status;
136 if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_STRING))
137 {
138 log_warn ("`%s' needs exactly one string argument.", ci->key);
139 return (-1);
140 }
142 re = calloc (1, sizeof (*re));
143 if (re == NULL)
144 {
145 log_err ("mr_config_add_regex: calloc failed.");
146 return (-1);
147 }
148 re->next = NULL;
150 re->re_str = strdup (ci->values[0].value.string);
151 if (re->re_str == NULL)
152 {
153 free (re);
154 log_err ("mr_config_add_regex: strdup failed.");
155 return (-1);
156 }
158 status = regcomp (&re->re, re->re_str, REG_EXTENDED | REG_NOSUB);
159 if (status != 0)
160 {
161 char errmsg[1024];
162 regerror (status, &re->re, errmsg, sizeof (errmsg));
163 errmsg[sizeof (errmsg) - 1] = 0;
164 log_err ("Compiling regex `%s' for `%s' failed: %s.",
165 re->re_str, ci->key, errmsg);
166 free (re->re_str);
167 free (re);
168 return (-1);
169 }
171 if (*re_head == NULL)
172 {
173 *re_head = re;
174 }
175 else
176 {
177 mr_regex_t *ptr;
179 ptr = *re_head;
180 while (ptr->next != NULL)
181 ptr = ptr->next;
183 ptr->next = re;
184 }
186 return (0);
187 } /* }}} int mr_config_add_regex */
189 static int mr_create (const oconfig_item_t *ci, void **user_data) /* {{{ */
190 {
191 mr_match_t *m;
192 int status;
194 m = calloc (1, sizeof (*m));
195 if (m == NULL)
196 {
197 log_err ("mr_create: calloc failed.");
198 return (-ENOMEM);
199 }
201 m->invert = 0;
203 status = 0;
204 for (int i = 0; i < ci->children_num; i++)
205 {
206 oconfig_item_t *child = ci->children + i;
208 if ((strcasecmp ("Host", child->key) == 0)
209 || (strcasecmp ("Hostname", child->key) == 0))
210 status = mr_config_add_regex (&m->host, child);
211 else if (strcasecmp ("Plugin", child->key) == 0)
212 status = mr_config_add_regex (&m->plugin, child);
213 else if (strcasecmp ("PluginInstance", child->key) == 0)
214 status = mr_config_add_regex (&m->plugin_instance, child);
215 else if (strcasecmp ("Type", child->key) == 0)
216 status = mr_config_add_regex (&m->type, child);
217 else if (strcasecmp ("TypeInstance", child->key) == 0)
218 status = mr_config_add_regex (&m->type_instance, child);
219 else if (strcasecmp ("Invert", child->key) == 0)
220 status = cf_util_get_boolean(child, &m->invert);
221 else
222 {
223 log_err ("The `%s' configuration option is not understood and "
224 "will be ignored.", child->key);
225 status = 0;
226 }
228 if (status != 0)
229 break;
230 }
232 /* Additional sanity-checking */
233 while (status == 0)
234 {
235 if ((m->host == NULL)
236 && (m->plugin == NULL)
237 && (m->plugin_instance == NULL)
238 && (m->type == NULL)
239 && (m->type_instance == NULL))
240 {
241 log_err ("No (valid) regular expressions have been configured. "
242 "This match will be ignored.");
243 status = -1;
244 }
246 break;
247 }
249 if (status != 0)
250 {
251 mr_free_match (m);
252 return (status);
253 }
255 *user_data = m;
256 return (0);
257 } /* }}} int mr_create */
259 static int mr_destroy (void **user_data) /* {{{ */
260 {
261 if ((user_data != NULL) && (*user_data != NULL))
262 mr_free_match (*user_data);
263 return (0);
264 } /* }}} int mr_destroy */
266 static int mr_match (const data_set_t __attribute__((unused)) *ds, /* {{{ */
267 const value_list_t *vl,
268 notification_meta_t __attribute__((unused)) **meta,
269 void **user_data)
270 {
271 mr_match_t *m;
272 int match_value = FC_MATCH_MATCHES;
273 int nomatch_value = FC_MATCH_NO_MATCH;
275 if ((user_data == NULL) || (*user_data == NULL))
276 return (-1);
278 m = *user_data;
280 if (m->invert)
281 {
282 match_value = FC_MATCH_NO_MATCH;
283 nomatch_value = FC_MATCH_MATCHES;
284 }
286 if (mr_match_regexen (m->host, vl->host) == FC_MATCH_NO_MATCH)
287 return (nomatch_value);
288 if (mr_match_regexen (m->plugin, vl->plugin) == FC_MATCH_NO_MATCH)
289 return (nomatch_value);
290 if (mr_match_regexen (m->plugin_instance,
291 vl->plugin_instance) == FC_MATCH_NO_MATCH)
292 return (nomatch_value);
293 if (mr_match_regexen (m->type, vl->type) == FC_MATCH_NO_MATCH)
294 return (nomatch_value);
295 if (mr_match_regexen (m->type_instance,
296 vl->type_instance) == FC_MATCH_NO_MATCH)
297 return (nomatch_value);
299 return (match_value);
300 } /* }}} int mr_match */
302 void module_register (void)
303 {
304 match_proc_t mproc = { 0 };
306 mproc.create = mr_create;
307 mproc.destroy = mr_destroy;
308 mproc.match = mr_match;
309 fc_register_match ("regex", mproc);
310 } /* module_register */
312 /* vim: set sw=4 ts=4 tw=78 noexpandtab fdm=marker : */