=back
+=head1 FILTER CONFIGURATION
+
+TODO: Update this entire section once development is done.
+
+Starting with collectd 4.6 there is a powerful filtering infrastructure
+implemented in the daemon. The concept has mostly been copied from I<iptables>,
+the packet filter infrastructure for Linux. We'll use a similar terminology, so
+that users that are familiar with iptables feel right at home.
+
+=head2 Terminology
+
+The most important terms are:
+
+=over 4
+
+=item B<Match>
+
+A I<match> is a criteria to select specific values. Examples are, of course, the
+name of the value or it's current value.
+
+=item B<Target>
+
+A I<target> is some action that is to be performed with data. Such actions
+could, for example, be to change part of the value's identifier or to ignore
+the value completely. Built-in functions are B<write> and B<stop>, see below.
+
+Some targets, for example the built-in B<stop> target, signal that processing
+of a value should be stopped. In that case processing of the current chain will
+be aborted.
+
+=item B<Rule>
+
+The combination of any number of matches and at least one target is called a
+I<rule>. The target actions will be performed for all values for which B<all>
+matches apply. If the rule does not have any matches associated with it, the
+target action will be performed for all values.
+
+If any target returns the stop condition, the processing will stop right away.
+This means that any targets following the current one will not be called after
+the stop condition has been returned.
+
+=item B<Chain>
+
+A I<chain> is a list of rules and possibly default targets. The rules are tried
+in order and if one matches, the associated target will be called. If a value
+is handled by a rule, it depends on the target whether or not any subsequent
+rules are considered or if traversal of the chain is aborted. After all rules
+have been checked and no target returned the stop condition, the default
+targets will be executed.
+
+=back
+
+=head2 General structure
+
+The following shows the resulting structure:
+
+ +---------+
+ ! Chain !
+ +---------+
+ !
+ V
+ +---------+ +---------+ +---------+ +---------+
+ ! Rule !->! Match !->! Match !->! Target !
+ +---------+ +---------+ +---------+ +---------+
+ !
+ V
+ +---------+ +---------+ +---------+
+ ! Rule !->! Target !->! Target !
+ +---------+ +---------+ +---------+
+ !
+ V
+ :
+ :
+ !
+ V
+ +---------+ +---------+ +---------+
+ ! Rule !->! Match !->! Target !
+ +---------+ +---------+ +---------+
+ !
+ V
+ +---------+
+ ! Default !
+ ! Target !
+ +---------+
+
+=head2 Synopsis
+
+The configuration reflects this structure directly:
+
+ <Chain "main">
+ <Rule "ignore_mysql_show">
+ <Match "regex">
+ Plugin "^mysql$"
+ Type "^mysql_command$"
+ TypeInstance "^show_"
+ </Match>
+ <Target "stop">
+ </Target>
+ </Rule>
+ <Target "write">
+ Plugin "rrdtool"
+ </Target>
+ </Chain>
+
+The above configuration example will ignore all values where the plugin field
+is "mysql", the type is "mysql_command" and the type instance begins with
+"show_". All other values will be sent to the "rrdtool" write plugin via the
+default target of the chain.
+
+=head2 List of configuration options
+
+=over 4
+
+=item B<Chain> I<Name>
+
+Adds a new chain with a certain name. This name can be used to refer to a
+specific chain, for example to jump to it.
+
+Within the B<Chain> block, there can be B<Rule> blocks and B<Target> blocks.
+
+=item B<Rule> [I<Name>]
+
+Adds a new rule to the current chain. The name of the rule is optional and
+currently has no meaning for the daemon.
+
+Within the B<Rule> block, there may be any number of B<Match> blocks and there
+must be at least one B<Target> block.
+
+=item B<Match> I<Name>
+
+Adds a match to a B<Rule> block. The name specifies what kind of match should
+be performed. Available matches depend on the plugins that have been loaded.
+
+The arguments inside the B<Match> block are passed to the plugin implementing
+the match, so which arguments are valid here depends on the plugin being used.
+If you do not need any to pass any arguments to a match, you can use the
+shorter syntax:
+
+ Match "foobar"
+
+Which is equivalent to:
+
+ <Match "foobar">
+ </Match>
+
+=item B<Target> I<Name>
+
+Add a target to a rule or a default target to a chain. The name specifies what
+kind of target is to be added. Which targets are available depends on the
+plugins being loaded.
+
+The arguments inside the B<Target> block are passed to the plugin implementing
+the target, so which arguments are valid here depends on the plugin being used.
+If you do not need any to pass any arguments to a target, you can use the
+shorter syntax:
+
+ Target "stop"
+
+This is the same as writing:
+
+ <Target "stop">
+ </Target>
+
+=back
+
+=head2 Built-in targets
+
+The following targets are built into the core daemon and therefore need no
+plugins to be loaded:
+
+=over 4
+
+=item B<stop>
+
+Does nothing except returning with the stop condition, causing processing of
+the current chain to be aborted.
+
+=item B<write>
+
+Sends the value to write plugins.
+
+Available options:
+
+=over 4
+
+=item B<Plugin> I<Name>
+
+Name of the write plugin to which the data should be sent. This option may be
+given multiple times to send the data to more than one write plugin.
+
+Example:
+
+ Target "stop"
+
+=back
+
+If no plugin is explicitly specified, the values will be sent to all available
+write plugins.
+
+Example:
+
+ <Target "write">
+ Plugin "rrdtool"
+ </Target>
+
+=item B<jump>
+
+Starts processing the rules of another chain. If the end of that chain is
+reached, or a stop condition is encountered, processing will continue right
+after the B<jump> target, i.E<nbsp>e. with the next target or the next rule.
+
+Available options:
+
+=over 4
+
+=item B<Chain> I<Name>
+
+Jumps to the chain I<Name>. This argument is required and may appear only once.
+
+=back
+
+Example:
+
+ <Target "jump">
+ Chain "foobar"
+ </Target>
+
+=back
+
+=head2 Backwards compatibility
+
+If you use collectd with an old configuration, i.E<nbsp>e. one without a
+B<Chain> block, it will behave as it used to. This is equivalent to the
+following configuration:
+
+ <Chain "main">
+ Target "write"
+ </Chain>
+
+If you specify a B<Chain> block anywhere, the B<write> target will not be added
+anywhere and you will have to make sure that it is called where appropriate. We
+suggest to add the above snippet as default target to your main chain.
+
+TODO: Notifications will be implemented using chains, too. Describe that here!
+
=head1 SEE ALSO
L<collectd(1)>,
--- /dev/null
+/**
+ * collectd - src/filter_chain.h
+ * Copyright (C) 2008 Florian octo Forster
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors:
+ * Florian octo Forster <octo at verplant.org>
+ **/
+
+/*
+ * First tell the compiler to stick to the C99 and POSIX standards as close as
+ * possible.
+ */
+#ifndef __STRICT_ANSI__ /* {{{ */
+# define __STRICT_ANSI__
+#endif
+
+#ifndef _ISOC99_SOURCE
+# define _ISOC99_SOURCE
+#endif
+
+#ifdef _POSIX_C_SOURCE
+# undef _POSIX_C_SOURCE
+#endif
+#define _POSIX_C_SOURCE 200112L
+
+#if 0
+/* Single UNIX needed for strdup. */
+#ifdef _XOPEN_SOURCE
+# undef _XOPEN_SOURCE
+#endif
+#define _XOPEN_SOURCE 500
+#endif
+
+#ifndef _REENTRANT
+# define _REENTRANT
+#endif
+
+#ifndef _THREAD_SAFE
+# define _THREAD_SAFE
+#endif
+
+#ifdef _GNU_SOURCE
+# undef _GNU_SOURCE
+#endif
+/* }}} */
+
+#include "collectd.h"
+#include "configfile.h"
+#include "plugin.h"
+#include "common.h"
+#include "filter_chain.h"
+
+/*
+ * Data types
+ */
+/* List of matches, used in fc_rule_t and for the global `match_list_head'
+ * variable. */
+struct fc_match_s;
+typedef struct fc_match_s fc_match_t; /* {{{ */
+struct fc_match_s
+{
+ char name[DATA_MAX_NAME_LEN];
+ match_proc_t proc;
+ void *user_data;
+ fc_match_t *next;
+}; /* }}} */
+
+/* List of targets, used in fc_rule_t and for the global `target_list_head'
+ * variable. */
+struct fc_target_s;
+typedef struct fc_target_s fc_target_t; /* {{{ */
+struct fc_target_s
+{
+ char name[DATA_MAX_NAME_LEN];
+ void *user_data;
+ target_proc_t proc;
+ fc_target_t *next;
+}; /* }}} */
+
+/* List of rules, used in fc_chain_t */
+struct fc_fule_s;
+typedef struct fc_fule_s fc_rule_t; /* {{{ */
+struct fc_fule_s
+{
+ char name[DATA_MAX_NAME_LEN];
+ fc_match_t *matches;
+ fc_target_t *targets;
+ fc_rule_t *next;
+}; /* }}} */
+
+/* List of chains, used for `chain_list_head' */
+struct fc_chain_s;
+typedef struct fc_chain_s fc_chain_t; /* {{{ */
+struct fc_chain_s
+{
+ char name[DATA_MAX_NAME_LEN];
+ fc_rule_t *rules;
+ fc_target_t *targets;
+ fc_chain_t *next;
+}; /* }}} */
+
+/*
+ * Global variables
+ */
+static fc_match_t *match_list_head;
+static fc_target_t *target_list_head;
+static fc_chain_t *chain_list_head;
+
+/*
+ * Private functions
+ */
+static void fc_free_matches (fc_match_t *m) /* {{{ */
+{
+ if (m == NULL)
+ return;
+
+ if (m->proc.destroy != NULL)
+ (*m->proc.destroy) (&m->user_data);
+ else if (m->user_data != NULL)
+ {
+ ERROR ("Filter sybsystem: fc_free_matches: There is user data, but no "
+ "destroy functions has been specified. "
+ "Memory will probably be lost!");
+ }
+
+ if (m->next != NULL)
+ fc_free_matches (m->next);
+
+ free (m);
+} /* }}} void fc_free_matches */
+
+static void fc_free_targets (fc_target_t *t) /* {{{ */
+{
+ if (t == NULL)
+ return;
+
+ if (t->proc.destroy != NULL)
+ (*t->proc.destroy) (&t->user_data);
+ else if (t->user_data != NULL)
+ {
+ ERROR ("Filter sybsystem: fc_free_targets: There is user data, but no "
+ "destroy functions has been specified. "
+ "Memory will probably be lost!");
+ }
+
+ if (t->next != NULL)
+ fc_free_targets (t->next);
+
+ free (t);
+} /* }}} void fc_free_targets */
+
+static void fc_free_rules (fc_rule_t *r) /* {{{ */
+{
+ if (r == NULL)
+ return;
+
+ fc_free_matches (r->matches);
+ fc_free_targets (r->targets);
+
+ if (r->next != NULL)
+ fc_free_rules (r->next);
+
+ free (r);
+} /* }}} void fc_free_rules */
+
+static void fc_free_chains (fc_chain_t *c) /* {{{ */
+{
+ if (c == NULL)
+ return;
+
+ fc_free_rules (c->rules);
+ fc_free_targets (c->targets);
+
+ if (c->next != NULL)
+ fc_free_chains (c->next);
+
+ free (c);
+} /* }}} void fc_free_chains */
+
+static char *fc_strdup (const char *orig) /* {{{ */
+{
+ size_t sz;
+ char *dest;
+
+ if (orig == NULL)
+ return (NULL);
+
+ sz = strlen (orig) + 1;
+ dest = (char *) malloc (sz);
+ if (dest == NULL)
+ return (NULL);
+
+ memcpy (dest, orig, sz);
+
+ return (dest);
+} /* }}} char *fc_strdup */
+
+/*
+ * Configuration.
+ *
+ * The configuration looks somewhat like this:
+ *
+ * <Chain "main">
+ * <Rule>
+ * <Match "regex">
+ * Plugin "^mysql$"
+ * Type "^mysql_command$"
+ * TypeInstance "^show_"
+ * </Match>
+ * <Target "drop">
+ * </Target>
+ * </Rule>
+ *
+ * <Target "write">
+ * Plugin "rrdtool"
+ * </Target>
+ * </Chain>
+ */
+static int fc_config_add_match (fc_match_t **matches_head, /* {{{ */
+ oconfig_item_t *ci)
+{
+ fc_match_t *m;
+ fc_match_t *ptr;
+ int status;
+
+ if ((ci->values_num != 1)
+ || (ci->values[0].type != OCONFIG_TYPE_STRING))
+ {
+ WARNING ("Filter subsystem: `Match' blocks require "
+ "exactly one string argument.");
+ return (-1);
+ }
+
+ ptr = match_list_head;
+ while (ptr != NULL)
+ {
+ if (strcasecmp (ptr->name, ci->values[0].value.string) == 0)
+ break;
+ ptr = ptr->next;
+ }
+
+ if (ptr == NULL)
+ {
+ WARNING ("Filter subsystem: Cannot find a \"%s\" match. "
+ "Did you load the appropriate plugin?",
+ ci->values[0].value.string);
+ return (-1);
+ }
+
+ m = (fc_match_t *) malloc (sizeof (*m));
+ if (m == NULL)
+ {
+ ERROR ("fc_config_add_match: malloc failed.");
+ return (-1);
+ }
+ memset (m, 0, sizeof (*m));
+
+ sstrncpy (m->name, ptr->name, sizeof (m->name));
+ memcpy (&m->proc, &ptr->proc, sizeof (m->proc));
+ assert (m->proc.create != NULL);
+ m->user_data = NULL;
+ m->next = NULL;
+
+ status = (*m->proc.create) (ci, &m->user_data);
+ if (status != 0)
+ {
+ WARNING ("Filter subsystem: Failed to create a %s match.",
+ m->name);
+ fc_free_matches (m);
+ return (-1);
+ }
+
+ if (*matches_head != NULL)
+ {
+ ptr = *matches_head;
+ while (ptr->next != NULL)
+ ptr = ptr->next;
+
+ ptr->next = m;
+ }
+ else
+ {
+ *matches_head = m;
+ }
+
+ return (0);
+} /* }}} int fc_config_add_match */
+
+static int fc_config_add_target (fc_target_t **targets_head, /* {{{ */
+ oconfig_item_t *ci)
+{
+ fc_target_t *t;
+ fc_target_t *ptr;
+ int status;
+
+ if ((ci->values_num != 1)
+ || (ci->values[0].type != OCONFIG_TYPE_STRING))
+ {
+ WARNING ("Filter subsystem: `Target' blocks require "
+ "exactly one string argument.");
+ return (-1);
+ }
+
+ ptr = target_list_head;
+ while (ptr != NULL)
+ {
+ if (strcasecmp (ptr->name, ci->values[0].value.string) == 0)
+ break;
+ ptr = ptr->next;
+ }
+
+ if (ptr == NULL)
+ {
+ WARNING ("Filter subsystem: Cannot find a \"%s\" target. "
+ "Did you load the appropriate plugin?",
+ ci->values[0].value.string);
+ return (-1);
+ }
+
+ t = (fc_target_t *) malloc (sizeof (*t));
+ if (t == NULL)
+ {
+ ERROR ("fc_config_add_match: malloc failed.");
+ return (-1);
+ }
+ memset (t, 0, sizeof (*t));
+
+ sstrncpy (t->name, ptr->name, sizeof (t->name));
+ memcpy (&t->proc, &ptr->proc, sizeof (t->proc));
+ assert (t->proc.create != NULL);
+ t->user_data = NULL;
+ t->next = NULL;
+
+ status = (*t->proc.create) (ci, &t->user_data);
+ if (status != 0)
+ {
+ WARNING ("Filter subsystem: Failed to create a %s match.",
+ t->name);
+ fc_free_targets (t);
+ return (-1);
+ }
+
+ if (*targets_head != NULL)
+ {
+ ptr = *targets_head;
+ while (ptr->next != NULL)
+ ptr = ptr->next;
+
+ ptr->next = t;
+ }
+ else
+ {
+ *targets_head = t;
+ }
+
+ return (0);
+} /* }}} int fc_config_add_target */
+
+static int fc_config_add_rule (fc_chain_t *chain, /* {{{ */
+ oconfig_item_t *ci)
+{
+ fc_rule_t *rule;
+ char rule_name[2*DATA_MAX_NAME_LEN] = "Unnamed rule";
+ int status = 0;
+ int i;
+
+ if (ci->values_num > 1)
+ {
+ WARNING ("Filter subsystem: `Rule' blocks have at most one argument.");
+ return (-1);
+ }
+ else if ((ci->values_num == 1)
+ && (ci->values[0].type != OCONFIG_TYPE_STRING))
+ {
+ WARNING ("Filter subsystem: `Rule' blocks expect one string argument "
+ "or no argument at all.");
+ return (-1);
+ }
+
+ rule = (fc_rule_t *) malloc (sizeof (*rule));
+ if (rule == NULL)
+ {
+ ERROR ("fc_config_add_rule: malloc failed.");
+ return (-1);
+ }
+ memset (rule, 0, sizeof (*rule));
+ rule->next = NULL;
+
+ if (ci->values_num == 1)
+ {
+ sstrncpy (rule->name, ci->values[0].value.string, sizeof (rule->name));
+ ssnprintf (rule_name, sizeof (rule_name), "Rule \"%s\"",
+ ci->values[0].value.string);
+ }
+
+ for (i = 0; i < ci->children_num; i++)
+ {
+ oconfig_item_t *option = ci->children + i;
+ status = 0;
+
+ if (strcasecmp ("Match", option->key) == 0)
+ status = fc_config_add_match (&rule->matches, option);
+ else if (strcasecmp ("Target", option->key) == 0)
+ status = fc_config_add_target (&rule->targets, option);
+ else
+ {
+ WARNING ("Filter subsystem: %s: Option `%s' not allowed "
+ "inside a <Rule> block.", rule_name, option->key);
+ status = -1;
+ }
+
+ if (status != 0)
+ break;
+ } /* for (ci->children) */
+
+ /* Additional sanity checking. */
+ while (status == 0)
+ {
+ if (rule->targets == NULL)
+ {
+ WARNING ("Filter subsystem: %s: No target has been specified.",
+ rule_name);
+ status = -1;
+ break;
+ }
+
+ break;
+ } /* while (status == 0) */
+
+ if (status != 0)
+ {
+ fc_free_rules (rule);
+ return (-1);
+ }
+
+ if (chain->rules != NULL)
+ {
+ fc_rule_t *ptr;
+
+ ptr = chain->rules;
+ while (ptr->next != NULL)
+ ptr = ptr->next;
+
+ ptr->next = rule;
+ }
+ else
+ {
+ chain->rules = rule;
+ }
+
+ return (0);
+} /* }}} int fc_config_add_rule */
+
+static int fc_config_add_chain (const oconfig_item_t *ci) /* {{{ */
+{
+ fc_chain_t *chain;
+ int status = 0;
+ int i;
+
+ if ((ci->values_num != 1)
+ || (ci->values[0].type != OCONFIG_TYPE_STRING))
+ {
+ WARNING ("Filter subsystem: <Chain> blocks require exactly one "
+ "string argument.");
+ return (-1);
+ }
+
+ chain = (fc_chain_t *) malloc (sizeof (*chain));
+ if (chain == NULL)
+ {
+ ERROR ("fc_config_add_chain: malloc failed.");
+ return (-1);
+ }
+ memset (chain, 0, sizeof (*chain));
+ sstrncpy (chain->name, ci->values[0].value.string, sizeof (chain->name));
+ chain->rules = NULL;
+ chain->targets = NULL;
+ chain->next = NULL;
+
+ for (i = 0; i < ci->children_num; i++)
+ {
+ oconfig_item_t *option = ci->children + i;
+ status = 0;
+
+ if (strcasecmp ("Rule", option->key) == 0)
+ status = fc_config_add_rule (chain, option);
+ else
+ {
+ WARNING ("Filter subsystem: Chain %s: Option `%s' not allowed "
+ "inside a <Chain> block.", chain->name, option->key);
+ status = -1;
+ }
+
+ if (status != 0)
+ break;
+ } /* for (ci->children) */
+
+ /* Additional sanity checking. */
+ while (status == 0)
+ {
+ if (chain->targets == NULL)
+ {
+ WARNING ("Filter subsystem: Chain %s: No default target has been "
+ "specified. Please make sure that there is a <Target> block within "
+ "the <Chain> block!", chain->name);
+ status = -1;
+ break;
+ }
+
+ break;
+ } /* while (status == 0) */
+
+ if (status != 0)
+ {
+ fc_free_chains (chain);
+ return (-1);
+ }
+
+ if (chain_list_head != NULL)
+ {
+ fc_chain_t *ptr;
+
+ ptr = chain_list_head;
+ while (ptr->next != NULL)
+ ptr = ptr->next;
+
+ ptr->next = chain;
+ }
+ else
+ {
+ chain_list_head = chain;
+ }
+
+ return (0);
+} /* }}} int fc_config_add_chain */
+
+int fc_process_chain (const data_set_t *ds, value_list_t *vl, /* {{{ */
+ fc_chain_t *chain)
+{
+ fc_rule_t *rule;
+ fc_target_t *target;
+ int status;
+
+ if (chain == NULL)
+ return (-1);
+
+ status = FC_ACTION_CONTINUE;
+
+ for (rule = chain->rules; rule != NULL; rule = rule->next)
+ {
+ fc_match_t *match;
+
+ /* N. B.: rule->matches may be NULL. */
+ for (match = rule->matches; match != NULL; match = match->next)
+ {
+ status = (*match->proc.match) (ds, vl, /* meta = */ NULL,
+ &match->user_data);
+ if (status < 0)
+ {
+ WARNING ("fc_process: A match failed.");
+ break;
+ }
+ else if (status != FC_MATCH_MATCHES)
+ break;
+ }
+
+ /* for-loop has been aborted: Either error or no match. */
+ if (match != NULL)
+ continue;
+
+ for (target = rule->targets; target != NULL; target = target->next)
+ {
+ /* If we get here, all matches have matched the value. Execute the target. */
+ status = (*target->proc.invoke) (ds, vl, /* meta = */ NULL,
+ &target->user_data);
+ if (status < 0)
+ {
+ WARNING ("fc_process: A target failed.");
+ continue;
+ }
+ else if (status == FC_ACTION_CONTINUE)
+ continue;
+ else if (status == FC_ACTION_STOP)
+ break;
+ else
+ {
+ WARNING ("fc_process: Unknown target return value: %i", status);
+ }
+ }
+
+ if (status == FC_ACTION_STOP)
+ break;
+ } /* for (rule) */
+
+ /* for-loop has been aborted: A target returned `FC_ACTION_STOP' */
+ if (rule != NULL)
+ return (0);
+
+ for (target = chain->targets; target != NULL; target = target->next)
+ {
+ /* If we get here, all matches have matched the value. Execute the target. */
+ status = (*target->proc.invoke) (ds, vl, /* meta = */ NULL,
+ &target->user_data);
+ if (status < 0)
+ {
+ WARNING ("fc_process: The default target failed.");
+ }
+ }
+
+ return (0);
+} /* }}} int fc_process_chain */
+
+/*
+ * Built-in target "jump"
+ *
+ * Prefix `bit' like `_b_uilt-_i_n _t_arget'
+ */
+static int fc_bit_jump_create (const oconfig_item_t *ci, /* {{{ */
+ void **user_data)
+{
+ oconfig_item_t *ci_chain;
+
+ if (ci->children_num != 1)
+ {
+ ERROR ("Filter subsystem: The built-in target `jump' needs exactly "
+ "one `Chain' argument!");
+ return (-1);
+ }
+
+ ci_chain = ci->children;
+ if (strcasecmp ("Chain", ci_chain->key) != 0)
+ {
+ ERROR ("Filter subsystem: The built-in target `jump' does not "
+ "support the configuration option `%s'.",
+ ci_chain->key);
+ return (-1);
+ }
+
+ if ((ci_chain->values_num != 1)
+ || (ci_chain->values[0].type != OCONFIG_TYPE_STRING))
+ {
+ ERROR ("Filter subsystem: Built-in target `jump': The `Chain' option "
+ "needs exactly one string argument.");
+ return (-1);
+ }
+
+ *user_data = fc_strdup (ci_chain->values[0].value.string);
+ if (*user_data == NULL)
+ {
+ ERROR ("fc_bit_jump_create: fc_strdup failed.");
+ return (-1);
+ }
+
+ return (0);
+} /* }}} int fc_bit_jump_create */
+
+static int fc_bit_jump_destroy (void **user_data) /* {{{ */
+{
+ if (user_data != NULL)
+ {
+ free (*user_data);
+ *user_data = NULL;
+ }
+
+ return (0);
+} /* }}} int fc_bit_jump_destroy */
+
+static int fc_bit_jump_invoke (const data_set_t *ds, /* {{{ */
+ value_list_t *vl, notification_meta_t **meta, void **user_data)
+{
+ char *chain_name;
+ fc_chain_t *chain;
+ int status;
+
+ chain_name = *user_data;
+
+ for (chain = chain_list_head; chain != NULL; chain = chain->next)
+ if (strcasecmp (chain_name, chain->name) == 0)
+ break;
+
+ if (chain == NULL)
+ {
+ ERROR ("Filter subsystem: Built-in target `jump': There is no chain "
+ "named `%s'.", chain_name);
+ return (-1);
+ }
+
+ status = fc_process_chain (ds, vl, chain);
+ if (status < 0)
+ return (status);
+
+ return (FC_ACTION_CONTINUE);
+} /* }}} int fc_bit_jump_invoke */
+
+static int fc_bit_stop_invoke (const data_set_t *ds, /* {{{ */
+ value_list_t *vl, notification_meta_t **meta, void **user_data)
+{
+ return (FC_ACTION_STOP);
+} /* }}} int fc_bit_stop_invoke */
+
+static int fc_bit_write_create (const oconfig_item_t *ci, /* {{{ */
+ void **user_data)
+{
+ int i;
+
+ char **plugin_list;
+ size_t plugin_list_len;
+
+ plugin_list = NULL;
+ plugin_list_len = 0;
+
+ for (i = 0; i < ci->children_num; i++)
+ {
+ oconfig_item_t *child = ci->children + i;
+ char **temp;
+ int j;
+
+ if (strcasecmp ("Plugin", child->key) != 0)
+ {
+ ERROR ("Filter subsystem: The built-in target `write' does not "
+ "support the configuration option `%s'.",
+ child->key);
+ continue;
+ }
+
+ for (j = 0; j < child->values_num; j++)
+ {
+ if (child->values[j].type != OCONFIG_TYPE_STRING)
+ {
+ ERROR ("Filter subsystem: Built-in target `write': "
+ "The `Plugin' option accepts only string arguments.");
+ continue;
+ }
+
+ temp = (char **) realloc (plugin_list, (plugin_list_len + 2)
+ * (sizeof (*plugin_list)));
+ if (temp == NULL)
+ {
+ ERROR ("fc_bit_write_create: realloc failed.");
+ continue;
+ }
+ plugin_list = temp;
+
+ plugin_list[plugin_list_len] = fc_strdup (child->values[j].value.string);
+ if (plugin_list[plugin_list_len] == NULL)
+ {
+ ERROR ("fc_bit_write_create: fc_strdup failed.");
+ continue;
+ }
+ plugin_list_len++;
+ plugin_list[plugin_list_len] = NULL;
+ } /* for (j = 0; j < child->values_num; j++) */
+ } /* for (i = 0; i < ci->children_num; i++) */
+
+ *user_data = plugin_list;
+
+ return (0);
+} /* }}} int fc_bit_write_create */
+
+static int fc_bit_write_destroy (void **user_data) /* {{{ */
+{
+ char **plugin_list;
+ size_t i;
+
+ if ((user_data == NULL) || (*user_data == NULL))
+ return (0);
+
+ plugin_list = *user_data;
+
+ for (i = 0; plugin_list[i] != NULL; i++)
+ free (plugin_list[i]);
+ free (plugin_list);
+
+ return (0);
+} /* }}} int fc_bit_write_destroy */
+
+static int fc_bit_write_invoke (const data_set_t *ds, /* {{{ */
+ value_list_t *vl, notification_meta_t **meta, void **user_data)
+{
+ char **plugin_list;
+ int status;
+
+ plugin_list = NULL;
+ if (user_data != NULL)
+ plugin_list = *user_data;
+
+ if ((plugin_list == NULL) || (plugin_list[0] == NULL))
+ {
+ status = plugin_write (/* plugin = */ NULL, ds, vl);
+ if (status != 0)
+ {
+ INFO ("Filter subsystem: Built-in target `write': Dispatching value to "
+ "all write plugins failed with status %i.", status);
+ }
+ }
+ else
+ {
+ size_t i;
+
+ for (i = 0; plugin_list[i] != NULL; i++)
+ {
+ status = plugin_write (plugin_list[i], ds, vl);
+ if (status != 0)
+ {
+ INFO ("Filter subsystem: Built-in target `write': Dispatching value to "
+ "the `%s' plugin failed with status %i.", plugin_list[i], status);
+ }
+ } /* for (i = 0; plugin_list[i] != NULL; i++) */
+ }
+
+ return (FC_ACTION_CONTINUE);
+} /* }}} int fc_bit_write_invoke */
+
+static int fc_init_once (void) /* {{{ */
+{
+ static int done = 0;
+ target_proc_t tproc;
+
+ if (done != 0)
+ return (0);
+
+ memset (&tproc, 0, sizeof (tproc));
+ tproc.create = fc_bit_jump_create;
+ tproc.destroy = fc_bit_jump_destroy;
+ tproc.invoke = fc_bit_jump_invoke;
+ fc_register_target ("jump", tproc);
+
+ memset (&tproc, 0, sizeof (tproc));
+ tproc.create = NULL;
+ tproc.destroy = NULL;
+ tproc.invoke = fc_bit_stop_invoke;
+ fc_register_target ("stop", tproc);
+
+ memset (&tproc, 0, sizeof (tproc));
+ tproc.create = fc_bit_write_create;
+ tproc.destroy = fc_bit_write_destroy;
+ tproc.invoke = fc_bit_write_invoke;
+ fc_register_target ("write", tproc);
+
+ done++;
+ return (0);
+} /* }}} int fc_init_once */
+
+/*
+ * Public functions
+ */
+/* Add a match to list of available matches. */
+int fc_register_match (const char *name, match_proc_t proc) /* {{{ */
+{
+ fc_match_t *m;
+
+ m = (fc_match_t *) malloc (sizeof (*m));
+ if (m == NULL)
+ return (-ENOMEM);
+ memset (m, 0, sizeof (*m));
+
+ sstrncpy (m->name, name, sizeof (m->name));
+ memcpy (&m->proc, &proc, sizeof (m->proc));
+ m->next = NULL;
+
+ if (match_list_head == NULL)
+ {
+ match_list_head = m;
+ }
+ else
+ {
+ fc_match_t *ptr;
+
+ ptr = match_list_head;
+ while (ptr->next != NULL)
+ ptr = ptr->next;
+
+ ptr->next = m;
+ }
+
+ return (0);
+} /* }}} int fc_register_match */
+
+/* Add a target to list of available targets. */
+int fc_register_target (const char *name, target_proc_t proc) /* {{{ */
+{
+ fc_target_t *t;
+
+ t = (fc_target_t *) malloc (sizeof (*t));
+ if (t == NULL)
+ return (-ENOMEM);
+ memset (t, 0, sizeof (*t));
+
+ sstrncpy (t->name, name, sizeof (t->name));
+ memcpy (&t->proc, &proc, sizeof (t->proc));
+ t->next = NULL;
+
+ if (target_list_head == NULL)
+ {
+ target_list_head = t;
+ }
+ else
+ {
+ fc_target_t *ptr;
+
+ ptr = target_list_head;
+ while (ptr->next != NULL)
+ ptr = ptr->next;
+
+ ptr->next = t;
+ }
+
+ return (0);
+} /* }}} int fc_register_target */
+
+/* Iterate over all rules in the chain and execute all targets for which all
+ * matches match. */
+int fc_process (const data_set_t *ds, value_list_t *vl) /* {{{ */
+{
+ fc_chain_t *chain;
+
+ for (chain = chain_list_head; chain != NULL; chain = chain->next)
+ if (strcasecmp ("Main", chain->name) == 0)
+ break;
+
+ if (chain != NULL)
+ return (fc_process_chain (ds, vl, chain));
+
+ ERROR ("fc_process: TODO: Implement default behavior!");
+
+ return (0);
+} /* }}} int fc_process */
+
+int fc_configure (const oconfig_item_t *ci) /* {{{ */
+{
+ fc_init_once ();
+
+ if (ci == NULL)
+ return (-EINVAL);
+
+ if (strcasecmp ("Chain", ci->key) == 0)
+ return (fc_config_add_chain (ci));
+
+ WARNING ("Filter subsystem: Unknown top level config option `%s'.",
+ ci->key);
+
+ return (-1);
+} /* }}} int fc_configure */
+
+/* vim: set sw=2 sts=2 et fdm=marker : */
projects / collectd.git / commitdiff