[glib-networking] Add GTLS_DEBUG to ease debugging

[Michael Catanzaro <mcatanzaro src gnome org>]

commit f856e264e917d82131e441f19e73b08a7644cc55
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Sat Nov 10 15:58:04 2018 -0600

    Add GTLS_DEBUG to ease debugging
    
    I've rewritten this at least three times now, and it takes a nontrivial
    amount of time to do so. Let's keep it permanently.

 tls/gnutls/gtlsconnection-gnutls.c | 32 ++++++++++++++++++++++++++++++++
 tls/gnutls/gtlsconnection-gnutls.h |  4 ++++
 2 files changed, 36 insertions(+)
---
diff --git a/tls/gnutls/gtlsconnection-gnutls.c b/tls/gnutls/gtlsconnection-gnutls.c
index 15ca40a..37f40a4 100644
--- a/tls/gnutls/gtlsconnection-gnutls.c
+++ b/tls/gnutls/gtlsconnection-gnutls.c
@@ -56,6 +56,7 @@
 #endif
 
 #include <glib/gi18n-lib.h>
+#include <glib/gprintf.h>
 
 /*
  * GTlsConnectionGnutls is the base abstract implementation of TLS and DTLS
@@ -2982,3 +2983,34 @@ g_tls_connection_gnutls_request_certificate (GTlsConnectionGnutls  *gnutls,
                                                       priv->read_cancellable, error);
   return res != G_TLS_INTERACTION_FAILED;
 }
+
+void
+GTLS_DEBUG (gpointer    gnutls,
+            const char *message,
+            ...)
+{
+  char *result = NULL;
+  int ret;
+
+  g_assert (G_IS_TLS_CONNECTION (gnutls));
+
+  va_list args;
+  va_start (args, message);
+
+  ret = g_vasprintf (&result, message, args);
+  g_assert (ret > 0);
+
+  if (G_IS_TLS_CLIENT_CONNECTION (gnutls))
+    g_printf ("CLIENT %p: ", gnutls);
+  else if (G_IS_TLS_SERVER_CONNECTION (gnutls))
+    g_printf ("SERVER %p: ", gnutls);
+  else
+    g_assert_not_reached ();
+
+  g_printf ("%s\n", result);
+
+  fflush (stdout);
+
+  g_free (result);
+  va_end (args);
+}
diff --git a/tls/gnutls/gtlsconnection-gnutls.h b/tls/gnutls/gtlsconnection-gnutls.h
index 71c69cd..028960b 100644
--- a/tls/gnutls/gtlsconnection-gnutls.h
+++ b/tls/gnutls/gtlsconnection-gnutls.h
@@ -90,6 +90,10 @@ gboolean g_tls_connection_gnutls_close_internal (GIOStream            *stream,
                                                  GCancellable         *cancellable,
                                                  GError              **error);
 
+void GTLS_DEBUG (gpointer    gnutls,
+                 const char *message,
+                 ...);
+
 G_END_DECLS
 
 #endif /* __G_TLS_CONNECTION_GNUTLS_H___ */