1 /**
2 * collectd - src/iptables.c
3 * Copyright (C) 2007 Sjoerd van der Berg
4 * Copyright (C) 2007-2010 Florian octo Forster
5 * Copyright (C) 2009 Marco Chiappero
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 *
21 * Authors:
22 * Sjoerd van der Berg <harekiet at users.sourceforge.net>
23 * Florian Forster <octo at collectd.org>
24 * Marco Chiappero <marco at absence.it>
25 **/
27 #include "collectd.h"
29 #include "common.h"
30 #include "plugin.h"
32 #include <libiptc/libiptc.h>
33 #include <libiptc/libip6tc.h>
35 #ifdef HAVE_SYS_CAPABILITY_H
36 # include <sys/capability.h>
37 #endif
39 /*
40 * iptc_handle_t was available before libiptc was officially available as a
41 * shared library. Note, that when the shared lib was introduced, the API and
42 * ABI have changed slightly:
43 * 'iptc_handle_t' used to be 'struct iptc_handle *' and most functions used
44 * 'iptc_handle_t *' as an argument. Now, most functions use 'struct
45 * iptc_handle *' (thus removing one level of pointer indirection).
46 *
47 * HAVE_IPTC_HANDLE_T is used to determine which API ought to be used. While
48 * this is somewhat hacky, I didn't find better way to solve that :-/
49 * -tokkee
50 */
51 #ifndef HAVE_IPTC_HANDLE_T
52 typedef struct iptc_handle iptc_handle_t;
53 #endif
54 #ifndef HAVE_IP6TC_HANDLE_T
55 typedef struct ip6tc_handle ip6tc_handle_t;
56 #endif
58 /*
59 * (Module-)Global variables
60 */
62 /*
63 * Config format should be `Chain table chainname',
64 * e. g. `Chain mangle incoming'
65 */
66 static const char *config_keys[] =
67 {
68 "Chain",
69 "Chain6"
70 };
71 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
72 enum protocol_version_e
73 {
74 IPV4,
75 IPV6
76 };
77 typedef enum protocol_version_e protocol_version_t;
79 /*
80 * Each table/chain combo that will be queried goes into this list
81 */
82 #ifndef XT_TABLE_MAXNAMELEN
83 # define XT_TABLE_MAXNAMELEN 32
84 #endif
85 typedef struct {
86 protocol_version_t ip_version;
87 char table[XT_TABLE_MAXNAMELEN];
88 char chain[XT_TABLE_MAXNAMELEN];
89 union
90 {
91 int num;
92 char *comment;
93 } rule;
94 enum
95 {
96 RTYPE_NUM,
97 RTYPE_COMMENT,
98 RTYPE_COMMENT_ALL
99 } rule_type;
100 char name[64];
101 } ip_chain_t;
103 static ip_chain_t **chain_list = NULL;
104 static int chain_num = 0;
106 static int iptables_config (const char *key, const char *value)
107 {
108 /* int ip_value; */
109 protocol_version_t ip_version = 0;
111 if (strcasecmp (key, "Chain") == 0)
112 ip_version = IPV4;
113 else if (strcasecmp (key, "Chain6") == 0)
114 ip_version = IPV6;
115 else
116 return (1);
118 ip_chain_t temp = { 0 };
119 ip_chain_t *final, **list;
120 char *table;
121 int table_len;
122 char *chain;
123 int chain_len;
125 char *value_copy;
126 char *fields[4];
127 int fields_num;
129 value_copy = strdup (value);
130 if (value_copy == NULL)
131 {
132 char errbuf[1024];
133 ERROR ("strdup failed: %s",
134 sstrerror (errno, errbuf, sizeof (errbuf)));
135 return (1);
136 }
138 /*
139 * Time to fill the temp element
140 * Examine value string, it should look like:
141 * Chain[6] <table> <chain> [<comment|num> [name]]
142 */
144 /* set IPv4 or IPv6 */
145 temp.ip_version = ip_version;
147 /* Chain <table> <chain> [<comment|num> [name]] */
148 fields_num = strsplit (value_copy, fields, 4);
149 if (fields_num < 2)
150 {
151 free (value_copy);
152 return (1);
153 }
155 table = fields[0];
156 chain = fields[1];
158 table_len = strlen (table) + 1;
159 if ((unsigned int)table_len > sizeof(temp.table))
160 {
161 ERROR ("Table `%s' too long.", table);
162 free (value_copy);
163 return (1);
164 }
165 sstrncpy (temp.table, table, table_len);
167 chain_len = strlen (chain) + 1;
168 if ((unsigned int)chain_len > sizeof(temp.chain))
169 {
170 ERROR ("Chain `%s' too long.", chain);
171 free (value_copy);
172 return (1);
173 }
174 sstrncpy (temp.chain, chain, chain_len);
176 if (fields_num >= 3)
177 {
178 char *comment = fields[2];
179 int rule = atoi (comment);
181 if (rule)
182 {
183 temp.rule.num = rule;
184 temp.rule_type = RTYPE_NUM;
185 }
186 else
187 {
188 temp.rule.comment = strdup (comment);
189 if (temp.rule.comment == NULL)
190 {
191 free (value_copy);
192 return (1);
193 }
194 temp.rule_type = RTYPE_COMMENT;
195 }
196 }
197 else
198 {
199 temp.rule_type = RTYPE_COMMENT_ALL;
200 }
202 if (fields_num >= 4)
203 sstrncpy (temp.name, fields[3], sizeof (temp.name));
205 free (value_copy);
206 value_copy = NULL;
207 table = NULL;
208 chain = NULL;
210 list = realloc (chain_list, (chain_num + 1) * sizeof (ip_chain_t *));
211 if (list == NULL)
212 {
213 char errbuf[1024];
214 ERROR ("realloc failed: %s",
215 sstrerror (errno, errbuf, sizeof (errbuf)));
216 sfree (temp.rule.comment);
217 return (1);
218 }
220 chain_list = list;
221 final = malloc(sizeof (*final));
222 if (final == NULL)
223 {
224 char errbuf[1024];
225 ERROR ("malloc failed: %s",
226 sstrerror (errno, errbuf, sizeof (errbuf)));
227 sfree (temp.rule.comment);
228 return (1);
229 }
230 memcpy (final, &temp, sizeof (temp));
231 chain_list[chain_num] = final;
232 chain_num++;
234 DEBUG ("Chain #%i: table = %s; chain = %s;", chain_num, final->table, final->chain);
236 return (0);
237 } /* int iptables_config */
239 static int submit6_match (const struct ip6t_entry_match *match,
240 const struct ip6t_entry *entry,
241 const ip_chain_t *chain,
242 int rule_num)
243 {
244 int status;
245 value_list_t vl = VALUE_LIST_INIT;
247 /* Select the rules to collect */
248 if (chain->rule_type == RTYPE_NUM)
249 {
250 if (chain->rule.num != rule_num)
251 return (0);
252 }
253 else
254 {
255 if (strcmp (match->u.user.name, "comment") != 0)
256 return (0);
257 if ((chain->rule_type == RTYPE_COMMENT)
258 && (strcmp (chain->rule.comment, (char *) match->data) != 0))
259 return (0);
260 }
262 sstrncpy (vl.plugin, "ip6tables", sizeof (vl.plugin));
264 status = ssnprintf (vl.plugin_instance, sizeof (vl.plugin_instance),
265 "%s-%s", chain->table, chain->chain);
266 if ((status < 1) || ((unsigned int)status >= sizeof (vl.plugin_instance)))
267 return (0);
269 if (chain->name[0] != '\0')
270 {
271 sstrncpy (vl.type_instance, chain->name, sizeof (vl.type_instance));
272 }
273 else
274 {
275 if (chain->rule_type == RTYPE_NUM)
276 ssnprintf (vl.type_instance, sizeof (vl.type_instance),
277 "%i", chain->rule.num);
278 else
279 sstrncpy (vl.type_instance, (char *) match->data,
280 sizeof (vl.type_instance));
281 }
283 sstrncpy (vl.type, "ipt_bytes", sizeof (vl.type));
284 vl.values = &(value_t) { .derive = (derive_t) entry->counters.bcnt };
285 vl.values_len = 1;
286 plugin_dispatch_values (&vl);
288 sstrncpy (vl.type, "ipt_packets", sizeof (vl.type));
289 vl.values = &(value_t) { .derive = (derive_t) entry->counters.pcnt };
290 plugin_dispatch_values (&vl);
292 return (0);
293 } /* int submit6_match */
295 /* This needs to return `int' for IPT_MATCH_ITERATE to work. */
296 static int submit_match (const struct ipt_entry_match *match,
297 const struct ipt_entry *entry,
298 const ip_chain_t *chain,
299 int rule_num)
300 {
301 int status;
302 value_list_t vl = VALUE_LIST_INIT;
304 /* Select the rules to collect */
305 if (chain->rule_type == RTYPE_NUM)
306 {
307 if (chain->rule.num != rule_num)
308 return (0);
309 }
310 else
311 {
312 if (strcmp (match->u.user.name, "comment") != 0)
313 return (0);
314 if ((chain->rule_type == RTYPE_COMMENT)
315 && (strcmp (chain->rule.comment, (char *) match->data) != 0))
316 return (0);
317 }
319 sstrncpy (vl.plugin, "iptables", sizeof (vl.plugin));
321 status = ssnprintf (vl.plugin_instance, sizeof (vl.plugin_instance),
322 "%s-%s", chain->table, chain->chain);
323 if ((status < 1) || ((unsigned int)status >= sizeof (vl.plugin_instance)))
324 return (0);
326 if (chain->name[0] != '\0')
327 {
328 sstrncpy (vl.type_instance, chain->name, sizeof (vl.type_instance));
329 }
330 else
331 {
332 if (chain->rule_type == RTYPE_NUM)
333 ssnprintf (vl.type_instance, sizeof (vl.type_instance),
334 "%i", chain->rule.num);
335 else
336 sstrncpy (vl.type_instance, (char *) match->data,
337 sizeof (vl.type_instance));
338 }
340 sstrncpy (vl.type, "ipt_bytes", sizeof (vl.type));
341 vl.values = &(value_t) { .derive = (derive_t) entry->counters.bcnt };
342 vl.values_len = 1;
343 plugin_dispatch_values (&vl);
345 sstrncpy (vl.type, "ipt_packets", sizeof (vl.type));
346 vl.values = &(value_t) { .derive = (derive_t) entry->counters.pcnt };
347 plugin_dispatch_values (&vl);
349 return (0);
350 } /* int submit_match */
353 /* ipv6 submit_chain */
354 static void submit6_chain (ip6tc_handle_t *handle, ip_chain_t *chain)
355 {
356 const struct ip6t_entry *entry;
357 int rule_num;
359 /* Find first rule for chain and use the iterate macro */
360 entry = ip6tc_first_rule( chain->chain, handle );
361 if (entry == NULL)
362 {
363 DEBUG ("ip6tc_first_rule failed: %s", ip6tc_strerror (errno));
364 return;
365 }
367 rule_num = 1;
368 while (entry)
369 {
370 if (chain->rule_type == RTYPE_NUM)
371 {
372 submit6_match (NULL, entry, chain, rule_num);
373 }
374 else
375 {
376 IP6T_MATCH_ITERATE( entry, submit6_match, entry, chain, rule_num );
377 }
379 entry = ip6tc_next_rule( entry, handle );
380 rule_num++;
381 } /* while (entry) */
382 }
385 /* ipv4 submit_chain */
386 static void submit_chain (iptc_handle_t *handle, ip_chain_t *chain)
387 {
388 const struct ipt_entry *entry;
389 int rule_num;
391 /* Find first rule for chain and use the iterate macro */
392 entry = iptc_first_rule( chain->chain, handle );
393 if (entry == NULL)
394 {
395 DEBUG ("iptc_first_rule failed: %s", iptc_strerror (errno));
396 return;
397 }
399 rule_num = 1;
400 while (entry)
401 {
402 if (chain->rule_type == RTYPE_NUM)
403 {
404 submit_match (NULL, entry, chain, rule_num);
405 }
406 else
407 {
408 IPT_MATCH_ITERATE( entry, submit_match, entry, chain, rule_num );
409 }
411 entry = iptc_next_rule( entry, handle );
412 rule_num++;
413 } /* while (entry) */
414 }
417 static int iptables_read (void)
418 {
419 int num_failures = 0;
420 ip_chain_t *chain;
422 /* Init the iptc handle structure and query the correct table */
423 for (int i = 0; i < chain_num; i++)
424 {
425 chain = chain_list[i];
427 if (!chain)
428 {
429 DEBUG ("iptables plugin: chain == NULL");
430 continue;
431 }
433 if ( chain->ip_version == IPV4 )
434 {
435 #ifdef HAVE_IPTC_HANDLE_T
436 iptc_handle_t _handle;
437 iptc_handle_t *handle = &_handle;
439 *handle = iptc_init (chain->table);
440 #else
441 iptc_handle_t *handle;
442 handle = iptc_init (chain->table);
443 #endif
445 if (!handle)
446 {
447 ERROR ("iptables plugin: iptc_init (%s) failed: %s",
448 chain->table, iptc_strerror (errno));
449 num_failures++;
450 continue;
451 }
453 submit_chain (handle, chain);
454 iptc_free (handle);
455 }
456 else if ( chain->ip_version == IPV6 )
457 {
458 #ifdef HAVE_IP6TC_HANDLE_T
459 ip6tc_handle_t _handle;
460 ip6tc_handle_t *handle = &_handle;
462 *handle = ip6tc_init (chain->table);
463 #else
464 ip6tc_handle_t *handle;
465 handle = ip6tc_init (chain->table);
466 #endif
467 if (!handle)
468 {
469 ERROR ("iptables plugin: ip6tc_init (%s) failed: %s",
470 chain->table, ip6tc_strerror (errno));
471 num_failures++;
472 continue;
473 }
475 submit6_chain (handle, chain);
476 ip6tc_free (handle);
477 }
478 else
479 num_failures++;
480 } /* for (i = 0 .. chain_num) */
482 return ((num_failures < chain_num) ? 0 : -1);
483 } /* int iptables_read */
485 static int iptables_shutdown (void)
486 {
487 for (int i = 0; i < chain_num; i++)
488 {
489 if ((chain_list[i] != NULL) && (chain_list[i]->rule_type == RTYPE_COMMENT))
490 sfree (chain_list[i]->rule.comment);
491 sfree (chain_list[i]);
492 }
493 sfree (chain_list);
495 return (0);
496 } /* int iptables_shutdown */
498 static int iptables_init (void)
499 {
500 #if defined(HAVE_SYS_CAPABILITY_H) && defined(CAP_NET_ADMIN)
501 if (check_capability (CAP_NET_ADMIN) != 0)
502 {
503 if (getuid () == 0)
504 WARNING ("iptables plugin: Running collectd as root, but the "
505 "CAP_NET_ADMIN capability is missing. The plugin's read "
506 "function will probably fail. Is your init system dropping "
507 "capabilities?");
508 else
509 WARNING ("iptables plugin: collectd doesn't have the CAP_NET_ADMIN "
510 "capability. If you don't want to run collectd as root, try "
511 "running \"setcap cap_net_admin=ep\" on the collectd binary.");
512 }
513 #endif
514 return (0);
515 } /* int iptables_init */
517 void module_register (void)
518 {
519 plugin_register_config ("iptables", iptables_config,
520 config_keys, config_keys_num);
521 plugin_register_init ("iptables", iptables_init);
522 plugin_register_read ("iptables", iptables_read);
523 plugin_register_shutdown ("iptables", iptables_shutdown);
524 } /* void module_register */