logging: support date modifiers in log filenames

Allow log filenames to contain date modifiers, e.g.:

  - eve-log:
    filename: eve-%Y-%m-%d-%H:%M:%S.json

src/util-logopenfile.c

@@ -160,6 +160,26 @@ static int SCLogFileWrite(const char *buffer, int buffer_len, LogFileCtx *log_ct
     return ret;
 }
 
+/** \brief generate filename based on pattern
+ *  \param pattern pattern to use
+ *  \retval char* on success
+ *  \retval NULL on error
+ */
+static char *SCLogFilenameFromPattern(const char *pattern)
+{
+    char *filename = SCMalloc(PATH_MAX);
+    if (filename == NULL) {
+        return NULL;
+    }
+
+    int rc = SCTimeToStringPattern(time(NULL), pattern, filename, PATH_MAX);
+    if (rc != 0) {
+        return NULL;
+    }
+
+    return filename;
+}
+
 static void SCLogFileClose(LogFileCtx *log_ctx)
 {
     if (log_ctx->fp)
@@ -178,25 +198,31 @@ SCLogOpenFileFp(const char *path, const char *append_setting, uint32_t mode)
 {
     FILE *ret = NULL;
 
+    char *filename = SCLogFilenameFromPattern(path);
+    if (filename == NULL) {
+        return NULL;
+    }
+
     if (ConfValIsTrue(append_setting)) {
-        ret = fopen(path, "a");
+        ret = fopen(filename, "a");
     } else {
-        ret = fopen(path, "w");
+        ret = fopen(filename, "w");
     }
 
     if (ret == NULL) {
         SCLogError(SC_ERR_FOPEN, "Error opening file: \"%s\": %s",
-                   path, strerror(errno));
+                   filename, strerror(errno));
     } else {
         if (mode != 0) {
-            int r = chmod(path, mode);
+            int r = chmod(filename, mode);
             if (r < 0) {
                 SCLogWarning(SC_WARN_CHMOD, "Could not chmod %s to %u: %s",
-                             path, mode, strerror(errno));
+                             filename, mode, strerror(errno));
             }
         }
     }
 
+    SCFree(filename);
     return ret;
 }
 

src/util-time.c

@@ -478,3 +478,37 @@ int SCStringPatternToTime (char *string, char **patterns, int num_patterns,
 
     return 0;
 }
+
+/**
+ * \brief Convert epoch time to string pattern.
+ *
+ * This function converts epoch time to a string based on a pattern.
+ *
+ * \param epoch   Epoch time.
+ * \param pattern String pattern.
+ * \param str     Formated string.
+ * \param size    Size of allocated string.
+ *
+ * \retval 0 on success.
+ * \retval 1 on failure.
+ */
+int SCTimeToStringPattern (time_t epoch, const char *pattern, char *str, size_t size)
+{
+    struct tm tm;
+    memset(&tm, 0, sizeof(tm));
+    struct tm *tp = (struct tm *)SCLocalTime(epoch, &tm);
+    char buffer[PATH_MAX] = { 0 };
+
+    if (unlikely(tp == NULL)) {
+        return 1;
+    }
+
+    int r = strftime(buffer, sizeof(buffer), pattern, tp);
+    if (r == 0) {
+        return 1;
+    }
+
+    strlcpy(str, buffer, size);
+
+    return 0;
+}

src/util-time.h

@@ -58,6 +58,8 @@ void CreateFormattedTimeString(const struct tm *t, const char * fmt, char *str,
 time_t SCMkTimeUtc(struct tm *tp);
 int SCStringPatternToTime(char *string, char **patterns,
                            int num_patterns, struct tm *time);
+int SCTimeToStringPattern (time_t epoch, const char *pattern, char *str,
+                           size_t size);
 
 #endif /* __UTIL_TIME_H__ */