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: https://origsvn.digium.com/svn/asterisk/trunk@203846 65c4cc65-6c06-0410-ace0-fbb531ad65f3

CHANGES

@@ -188,6 +188,8 @@ CDR
    linkedid is based on uniqueID, but spreads to other channels as transfers, dials,
    etc are performed. Thus the peices of CDR can be grouped into multilegged sets.
  * Multiple files and formats can now be specified in cdr_custom.conf.
+ * cdr_syslog has been added which allows CDRs to be written directly to syslog.
+   See configs/cdr_syslog.conf.sample for more information.
 
 Calendaring for Asterisk
 ------------------------

build_tools/menuselect-deps.in

@@ -49,6 +49,7 @@ SQLITE=@PBX_SQLITE@
 SS7=@PBX_SS7@
 OPENSSL=@PBX_OPENSSL@
 SUPPSERV=@PBX_SUPPSERV@
+SYSLOG=@PBX_SYSLOG@
 TONEZONE=@PBX_TONEZONE@
 UNIXODBC=@PBX_UNIXODBC@
 USB=@PBX_USB@

cdr/cdr_syslog.c

+/*
+ * 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,
+);

configs/cdr_syslog.conf.sample

+;
+; Asterisk Call Detail Records (CDR) - Syslog Backend
+;
+
+; The cdr_syslog module writes CDRs using the facilities provided by syslog.
+;
+; Not only must you configure cdr_syslog from this file (cdr_syslog.conf) but
+; you will also need to make changes to your /etc/syslog.conf before CDRs will
+; be written to syslog.
+;
+; As an example, you can add the following to /etc/syslog.conf:
+;
+;    local4.info        /var/log/asterisk-cdr.log
+;
+; And then instruct syslogd to re-read the configuration file by sending it a
+; HUP signal.  On Linux this can be done like this:
+;
+;    kill -HUP `cat /var/run/syslogd.pid`
+;
+; Finally, you will need to uncomment the [cdr-simple] section below, and restart
+; Asterisk.  When calls are placed, you should start seeing records appear in
+; /var/log/asterisk-cdr.log.
+
+[general]
+; Facility
+;
+; The 'facility' keyword specifies the syslog facility to use when writing out
+; CDRs.
+;
+; Accepted values: One of the following:
+;                  user, local0, local1, local2, local3, local4, local5, local6
+;                  and local7.
+;
+;                  Note: Depending on your platform, the following may also be
+;                        available:
+;                        auth, authpriv, cron, daemon, ftp, kern, lpr, mail,
+;                        news, syslog, and uucp.
+;
+; Default value:   local4
+
+;facility=local0
+
+; Priority
+;
+; Use the 'priority' keyword to select which of the syslog priority levels to
+; use when logging CDRs.
+;
+; Accepted values: One of the following:
+;                  alert, crit, debug, emerg, err, info, notice, warning
+; Default value:   info
+
+;priority=warn
+
+; Note: The settings for 'facility' and 'priority' in the [general] section
+;       define the default values for all of the logging locations created
+;       below in separate sections.
+
+;[cdr-master]
+;facility = local5
+;priority = debug
+
+; Template
+;
+; The 'template' value allows you to specify a custom format for messages
+; written to syslog.  This is similar to how cdr_custom is configured.
+;
+; Allowed values: A diaplan style string.
+; Default value:  None, this is required field.
+;
+; Note: Because of the way substitution is done, the only meaningful values
+;       available when the record is logged are those available via the CDR()
+;       dialplan function.  All other channel variables will be unavailable.
+
+;template = "${CDR(clid)}","${CDR(src)}","${CDR(dst)}","${CDR(dcontext)}","${CDR(channel)}","${CDR(dstchannel)}","${CDR(lastapp)}","${CDR(lastdata)}","${CDR(start)}","${CDR(answer)}","${CDR(end)}","${CDR(duration)}","${CDR(billsec)}","${CDR(disposition)}","${CDR(amaflags)}","${CDR(accountcode)}","${CDR(uniqueid)}","${CDR(userfield)}"
+
+;[cdr-simple]
+
+; Since we don't specify a facility or priority for this logging location, the
+; records will use the defaults specified in the [general] section.
+
+;template = "We received a call from ${CDR(src)}"

configure

 #! /bin/sh
-# From configure.ac Revision: 201137 .
+# From configure.ac Revision: 203569 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.61 for asterisk 1.6.
 #
@@ -1046,6 +1046,7 @@ PBX_SYSLOG_FACILITY_LOG_MAIL
 PBX_SYSLOG_FACILITY_LOG_NEWS
 PBX_SYSLOG_FACILITY_LOG_SYSLOG
 PBX_SYSLOG_FACILITY_LOG_UUCP
+PBX_SYSLOG
 LTLIBOBJS'
 ac_subst_files=''
       ac_precious_vars='build_alias
@@ -54504,6 +54505,8 @@ fi
+PBX_SYSLOG=0
+
 if test "${ac_cv_header_syslog_h}" = "yes"; then
    # syslog facilities
@@ -55342,8 +55345,11 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
     fi
+   PBX_SYSLOG=1
 fi
+
+
 ac_config_files="$ac_config_files build_tools/menuselect-deps makeopts channels/h323/Makefile"
@@ -56592,10 +56598,11 @@ PBX_SYSLOG_FACILITY_LOG_MAIL!$PBX_SYSLOG_FACILITY_LOG_MAIL$ac_delim
 PBX_SYSLOG_FACILITY_LOG_NEWS!$PBX_SYSLOG_FACILITY_LOG_NEWS$ac_delim
 PBX_SYSLOG_FACILITY_LOG_SYSLOG!$PBX_SYSLOG_FACILITY_LOG_SYSLOG$ac_delim
 PBX_SYSLOG_FACILITY_LOG_UUCP!$PBX_SYSLOG_FACILITY_LOG_UUCP$ac_delim
+PBX_SYSLOG!$PBX_SYSLOG$ac_delim
 LTLIBOBJS!$LTLIBOBJS$ac_delim
 _ACEOF
-  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 40; then
+  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 41; then
     break
   elif $ac_last_try; then
     { { echo "$as_me:$LINENO: error: could not make $CONFIG_STATUS" >&5

configure.ac

@@ -1747,6 +1747,8 @@ AC_SUBST([GENERIC_ODBC_LIB])
 AC_SUBST([GENERIC_ODBC_INCLUDE])
 AC_SUBST([PBX_GENERIC_ODBC])
 
+PBX_SYSLOG=0
+
 if test "${ac_cv_header_syslog_h}" = "yes"; then
    # syslog facilities
    AST_C_DEFINE_CHECK([SYSLOG_FACILITY_LOG_AUTH],     [LOG_AUTH],     [syslog.h])
@@ -1760,8 +1762,11 @@ if test "${ac_cv_header_syslog_h}" = "yes"; then
    AST_C_DEFINE_CHECK([SYSLOG_FACILITY_LOG_NEWS],     [LOG_NEWS],     [syslog.h])
    AST_C_DEFINE_CHECK([SYSLOG_FACILITY_LOG_SYSLOG],   [LOG_SYSLOG],   [syslog.h])
    AST_C_DEFINE_CHECK([SYSLOG_FACILITY_LOG_UUCP],     [LOG_UUCP],     [syslog.h])
+   PBX_SYSLOG=1
 fi
 
+AC_SUBST([PBX_SYSLOG])
+
 AC_CONFIG_FILES([build_tools/menuselect-deps makeopts channels/h323/Makefile])
 AST_CHECK_MANDATORY