syslog plugin: Copy the BUFFER_ADD() macro from src/utils_format_json.c.

Also determine the string representation of the severity in the switch
block, since it's much easier to read than the ?:-cascade.

Change-Id: Ieb5467633db3e06e1fad6a60b5a19fd7708e2002

diff --git a/src/syslog.c b/src/syslog.c
index a315351..4f5d0c4 100644 (file)
--- a/src/syslog.c
+++ b/src/syslog.c
@@ -80,57 +80,62 @@ static int sl_notification (const notification_t *n,
                user_data_t __attribute__((unused)) *user_data)
 {
        char  buf[1024] = "";
-       char *buf_ptr = buf;
-       int   buf_len = sizeof (buf);
-       int status;
+       size_t offset = 0;
        int log_severity;
+       char *severity_string;
+       int status;
 
        if (n->severity > notif_severity)
                return (0);
 
-       status = ssnprintf (buf_ptr, buf_len, "Notification: severity = %s",
-                       (n->severity == NOTIF_FAILURE) ? "FAILURE"
-                       : ((n->severity == NOTIF_WARNING) ? "WARNING"
-                               : ((n->severity == NOTIF_OKAY) ? "OKAY" : "UNKNOWN")));
-       if (status > 0)
-       {
-               buf_ptr += status;
-               buf_len -= status;
-       }
-
-#define APPEND(bufptr, buflen, key, value) \
-       if ((buflen > 0) && (strlen (value) > 0)) { \
-               int status = ssnprintf (bufptr, buflen, ", %s = %s", key, value); \
-               if (status > 0) { \
-                       bufptr += status; \
-                       buflen -= status; \
-               } \
-       }
-       APPEND (buf_ptr, buf_len, "host", n->host);
-       APPEND (buf_ptr, buf_len, "plugin", n->plugin);
-       APPEND (buf_ptr, buf_len, "plugin_instance", n->plugin_instance);
-       APPEND (buf_ptr, buf_len, "type", n->type);
-       APPEND (buf_ptr, buf_len, "type_instance", n->type_instance);
-       APPEND (buf_ptr, buf_len, "message", n->message);
-
-#undef APPEND
-
-       buf[sizeof (buf) - 1] = '\0';
-
        switch (n->severity)
        {
                case NOTIF_FAILURE:
+                       severity_string = "FAILURE";
                        log_severity = LOG_ERR;
                        break;
                case NOTIF_WARNING:
+                       severity_string = "WARNING";
                        log_severity = LOG_WARNING;
                        break;
                case NOTIF_OKAY:
+                       severity_string = "OKAY";
                        log_severity = LOG_NOTICE;
                        break;
                default:
+                       severity_string = "UNKNOWN";
                        log_severity = LOG_ERR;
        }
+
+#define BUFFER_ADD(...) do { \
+       status = ssnprintf (&buf[offset], sizeof (buf) - offset, \
+                       __VA_ARGS__); \
+       if (status < 1) \
+               return (-1); \
+       else if (((size_t) status) >= (sizeof (buf) - offset)) \
+               return (-ENOMEM); \
+       else \
+               offset += ((size_t) status); \
+} while (0)
+
+#define BUFFER_ADD_FIELD(field) do { \
+       if (n->field[0]) \
+               BUFFER_ADD (", " #field " = %s", n->field); \
+} while (0)
+
+       BUFFER_ADD ("Notification: severity = %s", severity_string);
+       BUFFER_ADD_FIELD (host);
+       BUFFER_ADD_FIELD (plugin);
+       BUFFER_ADD_FIELD (plugin_instance);
+       BUFFER_ADD_FIELD (type);
+       BUFFER_ADD_FIELD (type_instance);
+       BUFFER_ADD_FIELD (message);
+
+#undef BUFFER_ADD_FIELD
+#undef BUFFER_ADD
+
+       buf[sizeof (buf) - 1] = '\0';
+
        sl_log (log_severity, buf, NULL);
 
        return (0);