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/*
* Copyright (c) 2002-2013, 2015 Balabit
* Copyright (c) 1998-2013, 2015 Balázs Scheidler
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation, or (at your option) any later version.
*
* 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
*
* As an additional exemption you are allowed to compile & link against the
* OpenSSL libraries as published by the OpenSSL project. See the file
* COPYING for details.
*
*/
#include "pdb-ruleset.h"
#include "pdb-program.h"
#include "pdb-lookup-params.h"
#include "scratch-buffers.h"
static NVHandle class_handle = 0;
static NVHandle rule_id_handle = 0;
static LogTagId system_tag;
static LogTagId unknown_tag;
/**
* _add_matches_to_message:
*
* Adds the values from the given GArray of RParserMatch entries to the NVTable
* of the passed LogMessage.
*
* @msg: the LogMessage to add the matches to
* @matches: an array of RParserMatch entries
* @ref_handle: if the matches are indirect matches, they are referenced based on this handle (eg. LM_V_MESSAGE)
**/
static void
_add_matches_to_message(LogMessage *msg, GArray *matches, NVHandle ref_handle, const gchar *input_string)
{
gint i;
for (i = 0; i < matches->len; i++)
{
RParserMatch *match = &g_array_index(matches, RParserMatch, i);
if (match->match)
{
log_msg_set_value(msg, match->handle, match->match, match->len);
g_free(match->match);
}
else if (ref_handle != LM_V_NONE && log_msg_is_handle_settable_with_an_indirect_value(match->handle))
{
log_msg_set_value_indirect_with_type(msg, match->handle, ref_handle, match->ofs, match->len, match->type);
}
else
{
log_msg_set_value_with_type(msg, match->handle, input_string + match->ofs, match->len, match->type);
}
}
}
const gchar *
_calculate_program(PDBLookupParams *lookup, LogMessage *msg, gssize *program_len)
{
if (lookup->program_handle)
return log_msg_get_value(msg, lookup->program_handle, program_len);
GString *program = scratch_buffers_alloc();
log_template_format(lookup->program_template, msg, &DEFAULT_TEMPLATE_EVAL_OPTIONS, program);
*program_len = program->len;
return program->str;
}
/*
* Looks up a matching rule in the ruleset.
*
* NOTE: it also modifies @msg to store the name-value pairs found during lookup, so
*/
PDBRule *
pdb_ruleset_lookup(PDBRuleSet *rule_set, PDBLookupParams *lookup, GArray *dbg_list)
{
RNode *node;
LogMessage *msg = lookup->msg;
GArray *prg_matches, *matches;
const gchar *program_value;
gssize program_len;
if (G_UNLIKELY(!rule_set->programs))
return FALSE;
program_value = _calculate_program(lookup, msg, &program_len);
prg_matches = g_array_new(FALSE, TRUE, sizeof(RParserMatch));
node = r_find_node(rule_set->programs, (gchar *) program_value, program_len, prg_matches);
if (node)
{
_add_matches_to_message(msg, prg_matches, lookup->program_handle, program_value);
g_array_free(prg_matches, TRUE);
PDBProgram *program = (PDBProgram *) node->value;
if (program->rules)
{
RNode *msg_node;
const gchar *message;
gssize message_len;
/* NOTE: We're not using g_array_sized_new as that does not
* correctly zero-initialize the new items even if clear_ is TRUE
*/
matches = g_array_new(FALSE, TRUE, sizeof(RParserMatch));
g_array_set_size(matches, 1);
if (lookup->message_handle)
{
message = log_msg_get_value(msg, lookup->message_handle, &message_len);
}
else
{
message = lookup->message_string;
message_len = lookup->message_len;
}
if (G_UNLIKELY(dbg_list))
msg_node = r_find_node_dbg(program->rules, (gchar *) message, message_len, matches, dbg_list);
else
msg_node = r_find_node(program->rules, (gchar *) message, message_len, matches);
if (msg_node)
{
PDBRule *rule = (PDBRule *) msg_node->value;
GString *buffer = g_string_sized_new(32);
msg_debug("patterndb rule matches",
evt_tag_str("rule_id", rule->rule_id));
log_msg_set_value(msg, class_handle, rule->class ? rule->class : "system", -1);
log_msg_set_value(msg, rule_id_handle, rule->rule_id, -1);
_add_matches_to_message(msg, matches, lookup->message_handle, message);
g_array_free(matches, TRUE);
if (!rule->class)
{
log_msg_set_tag_by_id(msg, system_tag);
}
log_msg_clear_tag_by_id(msg, unknown_tag);
g_string_free(buffer, TRUE);
pdb_rule_ref(rule);
return rule;
}
else
{
log_msg_set_value(msg, class_handle, "unknown", 7);
log_msg_set_tag_by_id(msg, unknown_tag);
}
g_array_free(matches, TRUE);
}
}
else
{
g_array_free(prg_matches, TRUE);
}
return NULL;
}
PDBRuleSet *
pdb_rule_set_new(const gchar *prefix)
{
PDBRuleSet *self = g_new0(PDBRuleSet, 1);
self->is_empty = TRUE;
self->prefix = g_strdup(prefix);
return self;
}
void
pdb_rule_set_free(PDBRuleSet *self)
{
if (self->programs)
r_free_node(self->programs, (GDestroyNotify) pdb_program_unref);
g_free(self->version);
g_free(self->pub_date);
g_free(self->prefix);
g_free(self);
}
void
pdb_rule_set_global_init(void)
{
class_handle = log_msg_get_value_handle(".classifier.class");
rule_id_handle = log_msg_get_value_handle(".classifier.rule_id");
system_tag = log_tags_get_by_name(".classifier.system");
unknown_tag = log_tags_get_by_name(".classifier.unknown");
}
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