Improve logging in C providers

Use CMLogMessage instead of CMTraceMessage for each message with level
> ERROR.

The logging level is now read from the config file.

The Stderr option for logging to stderr in now also honored.

2 files changed, 89 insertions, 11 deletions

diff --git a/src/openlmi.c b/src/openlmi.c
index ac539bd..25cf57c 100644
--- a/src/openlmi.c
+++ b/src/openlmi.c
@@ -22,7 +22,6 @@
 
 #include <stdlib.h>
 #include <stdarg.h>
-#include <stdbool.h>
 #include <unistd.h>
 #include <sys/utsname.h>
 #include <string.h>
@@ -32,7 +31,6 @@
 #include <glib.h>
 
 static char *_fqdn = NULL;
-static int _log_level = _LMI_DEBUG_DEBUG;
 static const CMPIBroker *_cb = NULL;
 static char *_provider = NULL;
 
@@ -46,6 +44,12 @@ static pthread_mutex_t _init_mutex = PTHREAD_MUTEX_INITIALIZER;
 // Cache for SystemCreationClassName
 static char *_system_creation_class_name = NULL;
 
+// Cache for log level
+static int _log_level = _LMI_DEBUG_NONE;
+
+// Cache for log stderr
+static bool _log_stderr = false;
+
 static ConfigEntry _toplevel_config_defaults[] = {
     { "CIM", "Namespace", "root/cimv2" },
     { "CIM", "SystemClassName", "Linux_ComputerSystem" },
@@ -137,6 +141,24 @@ char *lmi_read_config(const char *group, const char *key)
     return g_key_file_get_string(_masterKeyFile, group, key, NULL);
 }
 
+bool lmi_read_config_boolean(const char *group, const char *key)
+{
+    char *value = lmi_read_config(group, key);
+    if (value == NULL) {
+        return false;
+    }
+    char *true_values[] = { "1", "yes", "true", "on" };
+    size_t len = sizeof(true_values) / sizeof(true_values[0]);
+    for (size_t i = 0; i < len; ++i) {
+        if (strcasecmp(true_values[i], value) == 0) {
+            free(value);
+            return true;
+        }
+    }
+    free(value);
+    return false;
+}
+
 GKeyFile *parse_config(const char *provider_name, const ConfigEntry *provider_config_defaults)
 {
     GError *error = NULL;
@@ -241,6 +263,8 @@ void lmi_init(const char *provider, const CMPIBroker *cb, const ConfigEntry *pro
     }
     // Read config only on first call of this function
     _masterKeyFile = parse_config(provider, provider_config_defaults);
+    // We might read different log config, reread it in next _log_debug call
+    _log_level = _LMI_DEBUG_NONE;
     pthread_mutex_unlock(&_init_mutex);
 }
 
@@ -262,6 +286,24 @@ void lmi_set_log_level(int level)
 void _lmi_debug(int level, const char *file, int line, const char *format, ...)
 {
     const char *lvl[] = { "NONE", "ERROR", "WARNING", "INFO", "DEBUG" };
+    if (_log_level == _LMI_DEBUG_NONE) {
+        // Read log level from config or default
+        _log_level = _LMI_DEBUG_ERROR; // Default
+        char *level = lmi_read_config("Log", "Level");
+        if (level != NULL) {
+            size_t len = sizeof(lvl) / sizeof(lvl[0]);
+            for (size_t i = 0; i < len; ++i) {
+                if (strcasecmp(level, lvl[i]) == 0) {
+                    _log_level = i;
+                    break;
+                }
+            }
+            free(level);
+        }
+
+        // Read if log to stderr
+        _log_stderr = lmi_read_config_boolean("Log", "Stderr");
+    }
     if (level > 4) {
         level = 4;
     }
@@ -269,6 +311,11 @@ void _lmi_debug(int level, const char *file, int line, const char *format, ...)
         level = 1;
     }
 
+    if (level > _log_level) {
+        // Do not log this message
+        return;
+    }
+
     char *message, *text;
     va_list args;
     va_start(args, format);
@@ -281,16 +328,28 @@ void _lmi_debug(int level, const char *file, int line, const char *format, ...)
     rc.rc = CMPI_RC_OK;
     if (_cb != NULL) {
         // try to use standard CMPI logging
-        rc = _cb->eft->trace(_cb, CMPI_LEV_INFO, _provider, text, NULL);
-    }
 
-    if (_cb == NULL || rc.rc != CMPI_RC_OK) {
-        // Fallback to stderr
-        if (level > _log_level) {
-            free(text);
-            return;
+        // CMPI has different severity levels (1=info, 4=fatal)
+        int severity = CMPI_SEV_INFO;
+        switch (level) {
+            case _LMI_DEBUG_DEBUG:
+                severity = CMPI_DEV_DEBUG;
+                break;
+            case _LMI_DEBUG_INFO:
+                severity = CMPI_SEV_INFO;
+                break;
+            case _LMI_DEBUG_WARN:
+                severity = CMPI_SEV_WARNING;
+                break;
+            case _LMI_DEBUG_ERROR:
+                severity = CMPI_SEV_ERROR;
+                break;
         }
+        rc = CMLogMessage(_cb, severity, _provider, text, NULL);
+    }
 
+    if (_log_stderr || _cb == NULL || rc.rc != CMPI_RC_OK) {
+        // Fallback to stderr
         fprintf(stderr, "%s\n", text);
     }
     free(text);
diff --git a/src/openlmi.h b/src/openlmi.h
index 93778ce..7d64bd1 100644
--- a/src/openlmi.h
+++ b/src/openlmi.h
@@ -22,6 +22,7 @@
 #define OPENLMI_H
 
 #include <cmpidt.h>
+#include <stdbool.h>
 
 typedef struct {
     const char *group;
@@ -78,11 +79,26 @@ void lmi_init(const char *provider, const CMPIBroker *cb,
 char *lmi_read_config(const char *group, const char *key);
 
 /**
+ * Reads a boolean value out of configuration files or default configuration
+ * options.
+ *
+ * Values "1", "yes", "true", and "on" are converted to TRUE, others to FALSE
+ *
+ * @param group Configration group
+ * @param key Configration key
+ * @return Boolean value of the key, false if the key is not in the
+ *         configuration files neither in default options.
+ */
+bool lmi_read_config_boolean(const char *group, const char *key);
+
+/**
  * To use standard CIMOM logging facility, broker must be assigned. Without
  * calling this function, logging will go to stderr.
  *
- * \p log_id Identification of log messages
- * \p cb CMPIBroker
+ * @deprecated Use lmi_init instead
+ *
+ * @param log_id Identification of log messages
+ * @param cb CMPIBroker
  */
 void lmi_init_logging(const char *log_id, const CMPIBroker *cb);
 
@@ -96,6 +112,9 @@ int lmi_log_level(void);
 /**
  * Set logging level
  *
+ * @note This method shouldn't be used directly, user setting
+ *       from the configuration file should be honored
+ *
  * @param level new logging level
  */
 void lmi_set_log_level(int level);