output: XML: support reopening file via SIGHUP

This feature is useful for log-rotation.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/output/ulogd_output_XML.c b/output/ulogd_output_XML.c
index fcc130d0f3b9bf628f475586443633c5311671ea..0ab843e989ed103950159965755467e3f7e57c0c 100644 (file)
--- a/output/ulogd_output_XML.c
+++ b/output/ulogd_output_XML.c
@@ -162,40 +162,41 @@ static int xml_fini(struct ulogd_pluginstance *pi)
        return 0;
 }
 
-static int xml_start(struct ulogd_pluginstance *upi)
+static int xml_open_file(struct ulogd_pluginstance *upi)
 {
-       struct xml_priv *op = (struct xml_priv *) &upi->private;
-       char buf[PATH_MAX], filename[FILENAME_MAX];
        time_t now;
        struct tm *tm;
+       char buf[PATH_MAX], filename[FILENAME_MAX];
+       struct xml_priv *op = (struct xml_priv *) &upi->private;
        int ret;
 
-       if (upi->config_kset->ces[CFG_XML_STDOUT].u.value != 0) {
-               op->of = stdout;
-       } else {
-               now = time(NULL);
-               tm = localtime(&now);
-               ret = snprintf(filename, sizeof(filename),
-                              "ulogd-%.2d%.2d%.4d-%.2d%.2d%.2d.xml",
-                              tm->tm_mday, tm->tm_mon + 1, 1900 + tm->tm_year,
-                              tm->tm_hour, tm->tm_min, tm->tm_sec);
-
-               if (ret == -1 || ret >= (int)sizeof(filename))
-                       return -1;
+       now = time(NULL);
+       tm = localtime(&now);
+       ret = snprintf(filename, sizeof(filename),
+                      "ulogd-%.2d%.2d%.4d-%.2d%.2d%.2d.xml",
+                      tm->tm_mday, tm->tm_mon + 1, 1900 + tm->tm_year,
+                      tm->tm_hour, tm->tm_min, tm->tm_sec);
 
-               ret = snprintf(buf, sizeof(buf), "%s/%s",
-                              upi->config_kset->ces[CFG_XML_DIR].u.string,
-                              filename);
-               if (ret == -1 || ret >= (int)sizeof(buf))
-                       return -1;
+       if (ret == -1 || ret >= (int)sizeof(filename))
+               return -1;
+
+       ret = snprintf(buf, sizeof(buf), "%s/%s",
+                      upi->config_kset->ces[CFG_XML_DIR].u.string,
+                      filename);
+       if (ret == -1 || ret >= (int)sizeof(buf))
+               return -1;
+
+       op->of = fopen(buf, "a");
+       if (!op->of)
+               return -1;
+
+       return 0;
+}
+
+static void xml_print_header(struct ulogd_pluginstance *upi)
+{
+       struct xml_priv *op = (struct xml_priv *) &upi->private;
 
-               op->of = fopen(buf, "a");
-               if (!op->of) {
-                       ulogd_log(ULOGD_FATAL, "can't open XML file: %s\n", 
-                                 strerror(errno));
-                       return -1;
-               }
-       }
        fprintf(op->of, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
 
        struct ulogd_pluginstance *input_plugin =
@@ -209,10 +210,44 @@ static int xml_start(struct ulogd_pluginstance *upi)
 
        if (upi->config_kset->ces[CFG_XML_SYNC].u.value != 0)
                fflush(op->of);
+}
+
+static int xml_start(struct ulogd_pluginstance *upi)
+{
+       struct xml_priv *op = (struct xml_priv *) &upi->private;
 
+       if (upi->config_kset->ces[CFG_XML_STDOUT].u.value != 0) {
+               op->of = stdout;
+       } else {
+               if (xml_open_file(upi) < 0) {
+                       ulogd_log(ULOGD_FATAL, "can't open XML file: %s\n", 
+                                 strerror(errno));
+                       return -1;
+               }
+       }
+       xml_print_header(upi);
        return 0;
 }
 
+static void
+xml_signal_handler(struct ulogd_pluginstance *upi, int signal)
+{
+       switch (signal) {
+       case SIGHUP:
+               ulogd_log(ULOGD_NOTICE, "XML: reopening logfile\n");
+               xml_fini(upi);
+               if (xml_open_file(upi) < 0) {
+                       ulogd_log(ULOGD_FATAL, "can't open XML file: %s\n", 
+                                 strerror(errno));
+                       return;
+               }
+               xml_print_header(upi);
+               break;
+       default:
+               break;
+       }
+}
+
 static struct ulogd_plugin xml_plugin = {
        .name = "XML",
        .input = {
@@ -230,6 +265,7 @@ static struct ulogd_plugin xml_plugin = {
        .start          = &xml_start,
        .stop           = &xml_fini,
        .interp         = &xml_output,
+       .signal         = &xml_signal_handler,
        .version        = ULOGD_VERSION,
 };