syslog: Add a message-id parameter for messages (#433)

The message-id parameter will enable systemd catalogs.
To enable message-id's the libqb should be configured with the
 --enable-systemd-journal option.

Co-authored-by: root <Aleksei Burlakov>

include/qb/qblog.h

@@ -249,6 +249,7 @@ typedef const char *(*qb_log_tags_stringify_fn)(uint32_t tags);
 
 /**
  * An instance of this structure is created for each log message
+ * with the message-id
  */
 struct qb_log_callsite {
 	const char *function;
@@ -258,6 +259,7 @@ struct qb_log_callsite {
 	uint32_t lineno;
 	uint32_t targets;
 	uint32_t tags;
+	const char *message_id;
 } __attribute__((aligned(8)));
 
 typedef void (*qb_log_filter_fn)(struct qb_log_callsite * cs);
@@ -319,6 +321,39 @@ struct qb_log_callsite* qb_log_callsite_get(const char *function,
 					    uint32_t lineno,
 					    uint32_t tags);
 
+/**
+ * Get or create a callsite at the given position.
+ * The same that qb_log_callsite_get but with the
+ * message_id parameter.
+ *
+ * The result can then be passed into qb_log_real_()
+ *
+ * @param message_id in the systemd catalog or NULL
+ * @param function originating function name
+ * @param filename originating filename
+ * @param format format string
+ * @param priority this takes syslog priorities.
+ * @param lineno file line number
+ * @param tags the tag
+ */
+struct qb_log_callsite* qb_log_callsite_get2(const char *message_id,
+					    const char *function,
+					    const char *filename,
+					    const char *format,
+					    uint8_t priority,
+					    uint32_t lineno,
+					    uint32_t tags);
+
+void qb_log_from_external_source_va2(const char *message_id,
+				    const char *function,
+				    const char *filename,
+				    const char *format,
+				    uint8_t priority,
+				    uint32_t lineno,
+				    uint32_t tags,
+				    va_list ap)
+	__attribute__ ((format (printf, 4, 0)));
+
 void qb_log_from_external_source_va(const char *function,
 				    const char *filename,
 				    const char *format,
@@ -332,6 +367,7 @@ void qb_log_from_external_source_va(const char *function,
  * This is the function to generate a log message if you want to
  * manually add tags.
  *
+ * @param message_id in the systemd catalog or NULL
  * @param priority this takes syslog priorities.
  * @param tags this is a uint32_t that you can use with
  *             qb_log_tags_stringify_fn_set() to "tag" a log message
@@ -340,13 +376,37 @@ void qb_log_from_external_source_va(const char *function,
  * @param fmt usual printf style format specifiers
  * @param args usual printf style args
  */
-#define qb_logt(priority, tags, fmt, args...) do {	\
+#define qb_logt2(message_id, priority, tags, fmt, args...) do {	\
 	struct qb_log_callsite* descriptor_pt =		\
-	qb_log_callsite_get(__func__, __FILE__, fmt,	\
+	qb_log_callsite_get2(message_id, __func__, __FILE__, fmt,	\
 			    priority, __LINE__, tags);	\
 	qb_log_real_(descriptor_pt, ##args);		\
     } while(0)
 
+/**
+ * This is the function to generate a log message if you want to
+ * manually add tags.
+ *
+ * @param priority this takes syslog priorities.
+ * @param tags this is a uint32_t that you can use with
+ *             qb_log_tags_stringify_fn_set() to "tag" a log message
+ *             with a feature or sub-system then you can use "%g"
+ *             in the format specifer to print it out.
+ * @param fmt usual printf style format specifiers
+ * @param args usual printf style args
+ */
+#define qb_logt(priority, tags, fmt, args...) qb_logt2(NULL, priority, tags, fmt, ##args)
+
+
+/**
+ * This is the main function to generate a log message.
+ *
+ * @param message_id in the systemd catalog or NULL
+ * @param priority this takes syslog priorities.
+ * @param fmt usual printf style format specifiers
+ * @param args usual printf style args
+ */
+#define qb_log2(message_id, priority, fmt, args...) qb_logt2(message_id, priority, 0, fmt, ##args)
 
 /**
  * This is the main function to generate a log message.

lib/log.c

@@ -317,7 +317,8 @@ qb_log_thread_log_write(struct qb_log_callsite *cs,
 }
 
 struct qb_log_callsite*
-qb_log_callsite_get(const char *function,
+qb_log_callsite_get2(const char *message_id,
+		    const char *function,
 		    const char *filename,
 		    const char *format,
 		    uint8_t priority,
@@ -335,8 +336,9 @@ qb_log_callsite_get(const char *function,
 		return NULL;
 	}
 
-	cs = qb_log_dcs_get(&new_dcs, function, filename,
-			    format, priority, lineno, tags);
+	cs = qb_log_dcs_get(&new_dcs, message_id, function, filename,
+ 			    format, priority, lineno, tags);
+
 	if (cs == NULL) {
 		return NULL;
 	}
@@ -380,8 +382,21 @@ qb_log_callsite_get(const char *function,
 	return cs;
 }
 
+struct qb_log_callsite*
+qb_log_callsite_get(const char *function,
+		    const char *filename,
+		    const char *format,
+		    uint8_t priority,
+		    uint32_t lineno,
+		    uint32_t tags)
+{
+	return qb_log_callsite_get2(NULL, function, filename, format,
+				    priority, lineno, tags);
+}
+
 void
-qb_log_from_external_source_va(const char *function,
+qb_log_from_external_source_va2(const char *message_id,
+			       const char *function,
 			       const char *filename,
 			       const char *format,
 			       uint8_t priority,
@@ -393,11 +408,22 @@ qb_log_from_external_source_va(const char *function,
 		return;
 	}
 
-	cs = qb_log_callsite_get(function, filename,
+	cs = qb_log_callsite_get2(message_id, function, filename,
 				 format, priority, lineno, tags);
 	qb_log_real_va_(cs, ap);
 }
 
+void
+qb_log_from_external_source_va(const char *function,
+			       const char *filename,
+			       const char *format,
+			       uint8_t priority,
+			       uint32_t lineno, uint32_t tags, va_list ap)
+{
+	qb_log_from_external_source_va2(NULL, function, filename,
+				   format, priority, lineno, tags, ap);
+}
+
 void
 qb_log_from_external_source(const char *function,
 			    const char *filename,

lib/log_dcs.c

@@ -58,7 +58,8 @@ _log_register_callsites(qb_array_t * a, uint32_t bin)
 }
 
 static struct qb_log_callsite *
-_log_dcs_new_cs(const char *function,
+_log_dcs_new_cs(const char *message_id,
+		const char *function,
 		const char *filename,
 		const char *format,
 		uint8_t priority, uint32_t lineno, uint32_t tags)
@@ -70,6 +71,7 @@ _log_dcs_new_cs(const char *function,
 	assert(rc == 0);
 	assert(cs != NULL);
 
+	cs->message_id = message_id ? strdup(message_id) : NULL;
 	cs->function = strdup(function);
 	cs->filename = strdup(filename);
 	cs->format = strdup(format);
@@ -82,6 +84,7 @@ _log_dcs_new_cs(const char *function,
 
 struct qb_log_callsite *
 qb_log_dcs_get(int32_t * newly_created,
+	       const char *message_id,
 	       const char *function,
 	       const char *filename,
 	       const char *format,
@@ -120,6 +123,7 @@ qb_log_dcs_get(int32_t * newly_created,
 	(void)qb_thread_lock(arr_next_lock);
 	if (csl_head->cs &&
 		priority == csl_head->cs->priority &&
+		(message_id ? (strcmp(message_id, csl_head->cs->message_id) == 0) : 1) &&
 		strcmp(safe_filename, csl_head->cs->filename) == 0 &&
 		strcmp(safe_format, csl_head->cs->format) == 0) {
 		(void)qb_thread_unlock(arr_next_lock);
@@ -130,7 +134,8 @@ qb_log_dcs_get(int32_t * newly_created,
 	 * so we will either have to create it or go through a list
 	 */
 	if (csl_head->cs == NULL) {
-		csl_head->cs = _log_dcs_new_cs(safe_function, safe_filename, safe_format,
+		csl_head->cs = _log_dcs_new_cs(message_id, safe_function,
+					       safe_filename, safe_format,
 					       priority, lineno, tags);
 		cs = csl_head->cs;
 		csl_head->next = NULL;
@@ -152,7 +157,8 @@ qb_log_dcs_get(int32_t * newly_created,
 			if (csl == NULL) {
 				goto cleanup;
 			}
-			csl->cs = _log_dcs_new_cs(safe_function, safe_filename, safe_format,
+			csl->cs = _log_dcs_new_cs(message_id, safe_function,
+						  safe_filename, safe_format,
 						  priority, lineno, tags);
 			csl->next = NULL;
 			csl_last->next = csl;

lib/log_int.h

@@ -125,6 +125,7 @@ void qb_log_thread_resume(struct qb_log_target *t);
 void qb_log_dcs_init(void);
 void qb_log_dcs_fini(void);
 struct qb_log_callsite *qb_log_dcs_get(int32_t *newly_created,
+				       const char *message_id,
 				       const char *function,
 				       const char *filename,
 				       const char *format,

lib/log_syslog.c

@@ -64,13 +64,24 @@ _syslog_logger(int32_t target,
 	}
 #ifdef USE_JOURNAL
 	if (t->use_journal) {
-		sd_journal_send("PRIORITY=%d", final_priority,
+		if (cs->message_id) {
+			sd_journal_send("MESSAGE_ID=%s", cs->message_id,
+				"PRIORITY=%d", final_priority,
 				"CODE_LINE=%d", cs->lineno,
 				"CODE_FILE=%s", cs->filename,
 				"CODE_FUNC=%s", cs->function,
 				"SYSLOG_IDENTIFIER=%s", t->name,
 				"MESSAGE=%s", output_buffer,
 				NULL);
+		} else {
+			sd_journal_send("PRIORITY=%d", final_priority,
+				"CODE_LINE=%d", cs->lineno,
+				"CODE_FILE=%s", cs->filename,
+				"CODE_FUNC=%s", cs->function,
+				"SYSLOG_IDENTIFIER=%s", t->name,
+				"MESSAGE=%s", output_buffer,
+				NULL);
+		}
 	} else {
 #endif
 		syslog(final_priority, "%s", output_buffer);

tests/check_log.c

@@ -1021,12 +1021,13 @@ START_TEST(test_journal)
 	pid_t log_pid;
 	sd_journal *jnl;
 	int count = 0;
+	const char *msgid="f77379a8490b408bbe5f6940505a777b";
 
 	qb_log_init("check_log", LOG_USER, LOG_DEBUG);
 	qb_log_ctl(QB_LOG_SYSLOG, QB_LOG_CONF_ENABLED, QB_TRUE);
 	rc = qb_log_ctl(QB_LOG_SYSLOG, QB_LOG_CONF_USE_JOURNAL, 1);
 	ck_assert_int_eq(rc, 0);
-	qb_log(LOG_ERR, "Test message 1 from libqb");
+	qb_log2(msgid, LOG_ERR, "Test message 1 from libqb");
 
 	qb_log_ctl(QB_LOG_BLACKBOX, QB_LOG_CONF_ENABLED, QB_TRUE);
 	rc = qb_log_ctl(QB_LOG_BLACKBOX, QB_LOG_CONF_USE_JOURNAL, 1);
@@ -1046,6 +1047,9 @@ START_TEST(test_journal)
 	    if (log_pid == getpid()) {
 	        rc = sd_journal_get_data(jnl, "MESSAGE", (const void **)&msg, &len);
 		ck_assert_int_eq(rc, 0);
+	        rc = sd_journal_get_data(jnl, "MESSAGE_ID", (const void **)&msg, &len);
+		ck_assert_int_eq(rc, 0);
+		ck_assert_str_eq(msg+11, msgid);
 		break;
 	    }
 	    if (++count > 20) {