log: Add support for journal logging

This logging is available if the software was build with the configure
option --with-systemd-journal.

It will be enabled by default if libsystemd is found.

The runtime parameter --log-journal enables to output of log messages
to the systemd journal.

Please note that the journal priority field has the same value as the
syslog level so no conversion is required here.

6 files changed, 71 insertions, 0 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 6b29bfe92..402b2ae93 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -46,6 +46,11 @@ AM_CFLAGS  += $(POLKIT_CFLAGS)
 AM_LDFLAGS += $(POLKIT_LIBS)
 endif
 
+if WITH_SYSTEMD_JOURNAL
+AM_CFLAGS += $(LIBSYSTEMD_CFLAGS)
+AM_LDFLAGS += $(LIBSYSTEMD_LIBS)
+endif
+
 ################################################################################
 # generic udev rules
 ################################################################################
diff --git a/src/main.c b/src/main.c
index c133abc93..b61cabd97 100644
--- a/src/main.c
+++ b/src/main.c
@@ -141,6 +141,7 @@ main (int argc, char *argv[])
 
     if (!mm_log_setup (mm_context_get_log_level (),
                        mm_context_get_log_file (),
+                       mm_context_get_log_journal (),
                        mm_context_get_log_timestamps (),
                        mm_context_get_log_relative_timestamps (),
                        &err)) {
diff --git a/src/mm-context.c b/src/mm-context.c
index 0a896e6d0..6b0dab79f 100644
--- a/src/mm-context.c
+++ b/src/mm-context.c
@@ -89,6 +89,7 @@ mm_context_get_no_auto_scan (void)
 
 static const gchar *log_level;
 static const gchar *log_file;
+static gboolean     log_journal;
 static gboolean     log_show_ts;
 static gboolean     log_rel_ts;
 
@@ -103,6 +104,13 @@ static const GOptionEntry log_entries[] = {
         "Path to log file",
         "[PATH]"
     },
+#if WITH_SYSTEMD_JOURNAL
+    {
+        "log-journal", 0, 0, G_OPTION_ARG_NONE, &log_journal,
+        "Log to systemd journal",
+        NULL
+    },
+#endif
     {
         "log-timestamps", 0, 0, G_OPTION_ARG_NONE, &log_show_ts,
         "Show timestamps in log output",
@@ -143,6 +151,12 @@ mm_context_get_log_file (void)
 }
 
 gboolean
+mm_context_get_log_journal (void)
+{
+    return log_journal;
+}
+
+gboolean
 mm_context_get_log_timestamps (void)
 {
     return log_show_ts;
diff --git a/src/mm-context.h b/src/mm-context.h
index e355692f6..143ee15b7 100644
--- a/src/mm-context.h
+++ b/src/mm-context.h
@@ -33,6 +33,7 @@ gboolean     mm_context_get_no_auto_scan          (void);
 /* Logging support */
 const gchar *mm_context_get_log_level               (void);
 const gchar *mm_context_get_log_file                (void);
+gboolean     mm_context_get_log_journal             (void);
 gboolean     mm_context_get_log_timestamps          (void);
 gboolean     mm_context_get_log_relative_timestamps (void);
 
diff --git a/src/mm-log.c b/src/mm-log.c
index fcbef34de..5691b26f1 100644
--- a/src/mm-log.c
+++ b/src/mm-log.c
@@ -35,6 +35,11 @@
 #include <libmbim-glib.h>
 #endif
 
+#if defined WITH_SYSTEMD_JOURNAL
+#define SD_JOURNAL_SUPPRESS_LOCATION
+#include <systemd/sd-journal.h>
+#endif
+
 #include "mm-log.h"
 
 enum {
@@ -148,6 +153,43 @@ log_backend_syslog (const char *loc,
     syslog (syslog_level, "%s", message);
 }
 
+#if defined WITH_SYSTEMD_JOURNAL
+static void
+log_backend_systemd_journal (const char *loc,
+                             const char *func,
+                             int syslog_level,
+                             const char *message,
+                             size_t length)
+{
+    const char *line;
+    size_t file_length;
+
+    if (loc == NULL) {
+        sd_journal_send ("MESSAGE=%s", message,
+                         "PRIORITY=%d", syslog_level,
+                         NULL);
+        return;
+    }
+
+    line = strstr (loc, ":");
+    if (line) {
+        file_length = line - loc;
+        line++;
+    } else {
+        /* This is not supposed to happen but we must be prepared for this */
+        line = loc;
+        file_length = 0;
+    }
+
+    sd_journal_send ("MESSAGE=%s", message,
+                     "PRIORITY=%d", syslog_level,
+                     "CODE_FUNC=%s", func,
+                     "CODE_FILE=%.*s", file_length, loc,
+                     "CODE_LINE=%s", line,
+                     NULL);
+}
+#endif
+
 void
 _mm_log (const char *loc,
          const char *func,
@@ -242,6 +284,7 @@ mm_log_set_level (const char *level, GError **error)
 gboolean
 mm_log_setup (const char *level,
               const char *log_file,
+              gboolean log_journal,
               gboolean show_timestamps,
               gboolean rel_timestamps,
               GError **error)
@@ -258,6 +301,12 @@ mm_log_setup (const char *level,
     /* Grab start time for relative timestamps */
     g_get_current_time (&rel_start);
 
+#if defined WITH_SYSTEMD_JOURNAL
+    if (log_journal) {
+        log_backend = log_backend_systemd_journal;
+        append_log_level_text = FALSE;
+    } else
+#endif
     if (log_file == NULL) {
         openlog (G_LOG_DOMAIN, LOG_CONS | LOG_PID | LOG_PERROR, LOG_DAEMON);
         log_backend = log_backend_syslog;
diff --git a/src/mm-log.h b/src/mm-log.h
index 6c34098ec..d9f11f27c 100644
--- a/src/mm-log.h
+++ b/src/mm-log.h
@@ -51,6 +51,7 @@ gboolean mm_log_set_level (const char *level, GError **error);
 
 gboolean mm_log_setup (const char *level,
                        const char *log_file,
+                       gboolean log_journal,
                        gboolean show_ts,
                        gboolean rel_ts,
                        GError **error);