journal: add native logger module for the SystemD Journal

NEWS

@@ -93,6 +93,7 @@ libVLC:
    identifier (if there is one available)
 
 Logging
+ * Support for the SystemD Journal
  * Use --syslog and --syslog-debug command line options to include debug
    messages in syslog. With --syslog, errors and warnings will be sent only.
 

configure.ac

@@ -868,6 +868,16 @@ AS_IF([test "${enable_dbus}" != "no"], [
 ])
 AM_CONDITIONAL([HAVE_DBUS], [test "${have_dbus}" = "yes"])
 
+
+dnl Check for systemd
+PKG_CHECK_MODULES([SYSTEMD], [libsystemd], [
+  have_systemd="yes"
+], [
+  AC_MSG_WARN([${SYSTEMD_PKG_ERRORS}.])
+])
+AM_CONDITIONAL([HAVE_SYSTEMD], [test "${have_systemd}" = "yes"])
+
+
 dnl Check for ntohl, etc.
 VLC_SAVE_FLAGS
 CFLAGS="${CFLAGS} -Wall -Werror"

modules/logger/Makefile.am

@@ -7,3 +7,10 @@ libsyslog_plugin_la_SOURCES = logger/syslog.c
 if HAVE_SYSLOG
 logger_LTLIBRARIES += libsyslog_plugin.la
 endif
+
+libsd_journal_plugin_la_SOURCES = logger/journal.c
+libsd_journal_plugin_la_CPPFLAGS = $(AM_CPPFLAGS) $(SYSTEMD_CFLAGS)
+libsd_journal_plugin_la_LIBADD = $(SYSTEMD_LIBS)
+if HAVE_SYSTEMD
+logger_LTLIBRARIES += libsd_journal_plugin.la
+endif

modules/logger/journal.c

@@ -0,0 +1,86 @@
+/*****************************************************************************
+ * journal.c: SystemD journal logger plugin
+ *****************************************************************************
+ * Copyright © 2015 Rémi Denis-Courmont
+ *
+ * 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; either version 2 of the License, 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 Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <stdarg.h>
+#include <inttypes.h>
+#include <syslog.h>
+#include <systemd/sd-journal.h>
+
+#include <vlc_common.h>
+#include <vlc_plugin.h>
+
+static const int priorities[4] = {
+    [VLC_MSG_INFO] = LOG_INFO,
+    [VLC_MSG_ERR]  = LOG_ERR,
+    [VLC_MSG_WARN] = LOG_WARNING,
+    [VLC_MSG_DBG]  = LOG_DEBUG,
+};
+
+static void Log(void *opaque, int type, const vlc_log_t *meta,
+                const char *format, va_list ap)
+{
+    static const char default_msg[] = "message lost";
+    char *msg;
+    int canc = vlc_savecancel();
+
+    if (vasprintf(&msg, format, ap) == -1)
+        msg = (char *)default_msg;
+
+    sd_journal_send("MESSAGE=%s", msg,
+        "PRIORITY=%d", priorities[type],
+        "CODE_FILE=%s", (meta->file != NULL) ? meta->file : "",
+        "CODE_LINE=%u", meta->line,
+        "CODE_FUNC=%s", (meta->func != NULL) ? meta->func : "",
+        //"ERRNO=%d"
+        "VLC_OBJECT_ID=%"PRIxPTR, meta->i_object_id,
+        "VLC_OBJECT_TYPE=%s", meta->psz_object_type,
+        "VLC_MODULE=%s", meta->psz_module,
+        "VLC_HEADER=%s", (meta->psz_header != NULL) ? meta->psz_header : "",
+        NULL);
+
+    vlc_restorecancel(canc);
+
+    if (msg != default_msg)
+        free(msg);
+    (void) opaque;
+}
+
+static vlc_log_cb Open(vlc_object_t *obj, void **sysp)
+{
+    if (!var_InheritBool(obj, "syslog"))
+        return NULL;
+
+    (void) sysp;
+    return Log;
+}
+
+vlc_module_begin()
+    set_shortname(N_("Journal"))
+    set_description(N_("SystemD journal logger"))
+    set_category(CAT_ADVANCED)
+    set_subcategory(SUBCAT_ADVANCED_MISC)
+    set_capability("logger", 30)
+    set_callbacks(Open, NULL)
+    add_shortcut("journal")
+vlc_module_end()