Add a new module, cdr_syslog, which allows writing CDRs to syslog.

The original patch for this was written by Brett Bryant, and I split it out into
it's own module.

(closes issue #12876)
Reported by: bbryant
Patches:
      06162008_cdr_custom_syslog.diff uploaded by bbryant (license 36)
      05212009_cdr_syslog.patch uploaded by seanbright (license 71)
Tested by: seanbright

Review: https://reviewboard.asterisk.org/r/297/


git-svn-id: http://svn.digium.com/svn/asterisk/trunk@203846 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 277 insertions, 0 deletions

diff --git a/cdr/cdr_syslog.c b/cdr/cdr_syslog.c
new file mode 100644
index 000000000..9455c7b24
--- /dev/null
+++ b/cdr/cdr_syslog.c
@@ -0,0 +1,277 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2009, malleable, LLC.
+ *
+ * Sean Bright <sean@malleable.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file cdr_syslog.c
+ *
+ * \brief syslog CDR logger
+ * \author Sean Bright <sean@malleable.com>
+ *
+ * See also
+ * \arg \ref Config_cdr
+ * \ingroup cdr_drivers
+ */
+
+/*** MODULEINFO
+	 <depend>syslog</depend>
+***/
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/module.h"
+#include "asterisk/lock.h"
+#include "asterisk/cdr.h"
+#include "asterisk/pbx.h"
+
+#include <syslog.h>
+
+#include "asterisk/syslog.h"
+
+static const char CONFIG[] = "cdr_syslog.conf";
+
+AST_THREADSTORAGE(syslog_buf);
+
+static const char name[] = "cdr-syslog";
+
+struct cdr_config {
+	AST_DECLARE_STRING_FIELDS(
+		AST_STRING_FIELD(ident);
+		AST_STRING_FIELD(format);
+	);
+	int facility;
+	int priority;
+	ast_mutex_t lock;
+	AST_LIST_ENTRY(cdr_config) list;
+};
+
+static AST_RWLIST_HEAD_STATIC(sinks, cdr_config);
+
+static void free_config(void)
+{
+	struct cdr_config *sink;
+	while ((sink = AST_RWLIST_REMOVE_HEAD(&sinks, list))) {
+		ast_mutex_destroy(&sink->lock);
+		ast_free(sink);
+	}
+}
+
+static int syslog_log(struct ast_cdr *cdr)
+{
+	struct ast_channel *dummy;
+	struct ast_str *str;
+	struct cdr_config *sink;
+
+	/* Batching saves memory management here.  Otherwise, it's the same as doing an
+	   allocation and free each time. */
+	if (!(str = ast_str_thread_get(&syslog_buf, 16))) {
+		return -1;
+	}
+
+	if (!(dummy = ast_dummy_channel_alloc())) {
+		ast_log(AST_LOG_ERROR, "Unable to allocate channel for variable substitution.\n");
+		return -1;
+	}
+
+	/* We need to dup here since the cdr actually belongs to the other channel,
+	   so when we release this channel we don't want the CDR getting cleaned
+	   up prematurely. */
+	dummy->cdr = ast_cdr_dup(cdr);
+
+	AST_RWLIST_RDLOCK(&sinks);
+
+	AST_LIST_TRAVERSE(&sinks, sink, list) {
+
+		ast_str_substitute_variables(&str, 0, dummy, sink->format);
+
+		/* Even though we have a lock on the list, we could be being chased by
+		   another thread and this lock ensures that we won't step on anyone's
+		   toes.  Once each CDR backend gets it's own thread, this lock can be
+		   removed. */
+		ast_mutex_lock(&sink->lock);
+
+		openlog(sink->ident, LOG_CONS, sink->facility);
+		syslog(sink->priority, "%s", ast_str_buffer(str));
+		closelog();
+
+		ast_mutex_unlock(&sink->lock);
+	}
+
+	AST_RWLIST_UNLOCK(&sinks);
+
+	ast_channel_release(dummy);
+
+	return 0;
+}
+
+static int load_config(int reload)
+{
+	struct ast_config *cfg;
+	struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
+	int default_facility = LOG_LOCAL4;
+	int default_priority = LOG_INFO;
+	const char *catg = NULL, *tmp;
+
+	cfg = ast_config_load(CONFIG, config_flags);
+	if (cfg == CONFIG_STATUS_FILEMISSING || cfg == CONFIG_STATUS_FILEINVALID) {
+		ast_log(AST_LOG_ERROR,
+			"Unable to load %s. Not logging custom CSV CDRs to syslog.\n", CONFIG);
+		return -1;
+	} else if (cfg == CONFIG_STATUS_FILEUNCHANGED) {
+		return 0;
+	}
+
+	if (reload) {
+		free_config();
+	}
+
+	if (!(ast_strlen_zero(tmp = ast_variable_retrieve(cfg, "general", "facility")))) {
+		int facility = ast_syslog_facility(tmp);
+		if (facility < 0) {
+			ast_log(AST_LOG_WARNING,
+				"Invalid facility '%s' specified, defaulting to '%s'\n",
+				tmp, ast_syslog_facility_name(default_facility));
+		} else {
+			default_facility = facility;
+		}
+	}
+
+	if (!(ast_strlen_zero(tmp = ast_variable_retrieve(cfg, "general", "priority")))) {
+		int priority = ast_syslog_priority(tmp);
+		if (priority < 0) {
+			ast_log(AST_LOG_WARNING,
+				"Invalid priority '%s' specified, defaulting to '%s'\n",
+				tmp, ast_syslog_priority_name(default_priority));
+		} else {
+			default_priority = priority;
+		}
+	}
+
+	while ((catg = ast_category_browse(cfg, catg))) {
+		struct cdr_config *sink;
+
+		if (!strcasecmp(catg, "general")) {
+			continue;
+		}
+
+		if (ast_strlen_zero(tmp = ast_variable_retrieve(cfg, catg, "template"))) {
+			ast_log(AST_LOG_WARNING,
+				"No 'template' parameter found for '%s'.  Skipping.\n", catg);
+			continue;
+		}
+
+		sink = ast_calloc_with_stringfields(1, struct cdr_config, 1024);
+
+		if (!sink) {
+			ast_log(AST_LOG_ERROR,
+				"Unable to allocate memory for configuration settings.\n");
+			free_config();
+			break;
+		}
+
+		ast_mutex_init(&sink->lock);
+		ast_string_field_set(sink, ident, catg);
+		ast_string_field_set(sink, format, tmp);
+
+		if (ast_strlen_zero(tmp = ast_variable_retrieve(cfg, catg, "facility"))) {
+			sink->facility = default_facility;
+		} else {
+			int facility = ast_syslog_facility(tmp);
+			if (facility < 0) {
+				ast_log(AST_LOG_WARNING,
+					"Invalid facility '%s' specified for '%s,' defaulting to '%s'\n",
+					tmp, catg, ast_syslog_facility_name(default_facility));
+			} else {
+				sink->facility = facility;
+			}
+		}
+
+		if (ast_strlen_zero(tmp = ast_variable_retrieve(cfg, catg, "priority"))) {
+			sink->priority = default_priority;
+		} else {
+			int priority = ast_syslog_priority(tmp);
+			if (priority < 0) {
+				ast_log(AST_LOG_WARNING,
+					"Invalid priority '%s' specified for '%s,' defaulting to '%s'\n",
+					tmp, catg, ast_syslog_priority_name(default_priority));
+			} else {
+				sink->priority = priority;
+			}
+		}
+
+		AST_RWLIST_INSERT_TAIL(&sinks, sink, list);
+	}
+
+	ast_config_destroy(cfg);
+
+	return AST_RWLIST_EMPTY(&sinks) ? -1 : 0;
+}
+
+static int unload_module(void)
+{
+	ast_cdr_unregister(name);
+
+	if (AST_RWLIST_WRLOCK(&sinks)) {
+		ast_cdr_register(name, ast_module_info->description, syslog_log);
+		ast_log(AST_LOG_ERROR, "Unable to lock sink list.  Unload failed.\n");
+		return -1;
+	}
+
+	free_config();
+	AST_RWLIST_UNLOCK(&sinks);
+	return 0;
+}
+
+static enum ast_module_load_result load_module(void)
+{
+	int res;
+
+	if (AST_RWLIST_WRLOCK(&sinks)) {
+		ast_log(AST_LOG_ERROR, "Unable to lock sink list.  Load failed.\n");
+		return AST_MODULE_LOAD_DECLINE;
+	}
+
+	res = load_config(0);
+	AST_RWLIST_UNLOCK(&sinks);
+	if (res) {
+		return AST_MODULE_LOAD_DECLINE;
+	}
+	ast_cdr_register(name, ast_module_info->description, syslog_log);
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+static int reload(void)
+{
+	int res;
+	if (AST_RWLIST_WRLOCK(&sinks)) {
+		ast_log(AST_LOG_ERROR, "Unable to lock sink list.  Load failed.\n");
+		return AST_MODULE_LOAD_DECLINE;
+	}
+
+	free_config();
+	res = load_config(1);
+	AST_RWLIST_UNLOCK(&sinks);
+
+	return res ? AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS;
+}
+
+AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "Customizable syslog CDR Backend",
+	.load = load_module,
+	.unload = unload_module,
+	.reload = reload,
+);