krb5 commit: Trace log on k5tls load failure

[Greg Hudson]

https://github.com/krb5/krb5/commit/d43d811ea80966434910619b479212f3ed987ca4
commit d43d811ea80966434910619b479212f3ed987ca4
Author: Greg Hudson <ghudson at mit.edu>
Date:   Wed Jan 17 18:31:43 2018 -0500

    Trace log on k5tls load failure
    
    If sendto_kdc fails to establish an MS-KKDCP connection because the
    k5tls module cannot be loaded, output a trace log before closing the
    connection.  Reported by Jochen Hein.
    
    ticket: 8634 (new)

 src/include/k5-trace.h       |    2 ++
 src/lib/krb5/os/sendto_kdc.c |    6 +++++-
 2 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/src/include/k5-trace.h b/src/include/k5-trace.h
index 390a8b7..27c9d14 100644
--- a/src/include/k5-trace.h
+++ b/src/include/k5-trace.h
@@ -364,6 +364,8 @@ void krb5int_trace(krb5_context context, const char *fmt, ...);
 #define TRACE_SENDTO_KDC(c, len, rlm, master, tcp)                     \
     TRACE(c, "Sending request ({int} bytes) to {data}{str}{str}", len,  \
           rlm, (master) ? " (master)" : "", (tcp) ? " (tcp only)" : "")
+#define TRACE_SENDTO_KDC_K5TLS_LOAD_ERROR(c, ret)       \
+    TRACE(c, "Error loading k5tls module: {kerr}", ret)
 #define TRACE_SENDTO_KDC_MASTER(c, master)                              \
     TRACE(c, "Response was{str} from master KDC", (master) ? "" : " not")
 #define TRACE_SENDTO_KDC_RESOLVING(c, hostname)         \
diff --git a/src/lib/krb5/os/sendto_kdc.c b/src/lib/krb5/os/sendto_kdc.c
index e8bc0ad..80c08f6 100644
--- a/src/lib/krb5/os/sendto_kdc.c
+++ b/src/lib/krb5/os/sendto_kdc.c
@@ -151,6 +151,7 @@ static krb5_error_code
 init_tls_vtable(krb5_context context)
 {
     krb5_plugin_initvt_fn initfn;
+    krb5_error_code ret;
 
     if (context->tls != NULL)
         return 0;
@@ -161,8 +162,11 @@ init_tls_vtable(krb5_context context)
 
     /* Attempt to load the module; just let it stay nulled out on failure. */
     k5_plugin_register_dyn(context, PLUGIN_INTERFACE_TLS, "k5tls", "tls");
-    if (k5_plugin_load(context, PLUGIN_INTERFACE_TLS, "k5tls", &initfn) == 0)
+    ret = k5_plugin_load(context, PLUGIN_INTERFACE_TLS, "k5tls", &initfn);
+    if (!ret)
         (*initfn)(context, 0, 0, (krb5_plugin_vtable)context->tls);
+    else
+        TRACE_SENDTO_KDC_K5TLS_LOAD_ERROR(context, ret);
 
     return 0;
 }