Add locking around keystore operations.

1 files changed, 108 insertions, 0 deletions

diff --git a/locks.c b/locks.c
new file mode 100644
index 0000000..2165753
--- /dev/null
+++ b/locks.c
@@ -0,0 +1,108 @@
+/*
+ * locks.c
+ * -------
+ * Dummy lock code for libhal.
+ *
+ * Copyright (c) 2017, NORDUnet A/S All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of the NORDUnet nor the names of its contributors may
+ *   be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "hal.h"
+#include "hal_internal.h"
+
+/*
+ * There are three slightly peculiar things about this module.
+ *
+ * 1) We want to include optional support for GNU weak functions,
+ *    because they're convenient, but we don't want to require support
+ *    for them.  So we wrap this in a compilation time conditional
+ *    which defaults to something compatible with C99, but allow this
+ *    to be overriden via an external definition.
+ *
+ * 2) The functions in this module are all no-ops, just here so that
+ *    things will link correctly on platforms that don't define them.
+ *    Real definitions for these functions have to come from the port
+ *    to a specific environment, eg, from sw/stm32/projects/hsm.c.
+ *
+ * 3) Because we want to expose as little as possible of the
+ *    underlying mechanisms, some of the functions here are closures
+ *    encapsulating objects things which would otherwise be arguments.
+ *    So, for example, we have functions to lock and unlock the HSM
+ *    keystore, rather than general lock and unlock functions which
+ *    they HSM keystore lock as an argument.  Since the versions in
+ *    this file are the no-ops, the lock itself goes away here.
+ */
+
+#ifndef ENABLE_WEAK_FUNCTIONS
+#define ENABLE_WEAK_FUNCTIONS 0
+#endif
+
+#if ENABLE_WEAK_FUNCTIONS
+#define WEAK_FUNCTION __attribute__((weak))
+#else
+#define WEAK_FUNCTION
+#endif
+
+/*
+ * Critical sections -- disable preemption BRIEFLY.
+ */
+
+WEAK_FUNCTION void hal_critical_section_start(void)
+{
+  return;
+}
+
+WEAK_FUNCTION void hal_critical_section_end(void)
+{
+  return;
+}
+
+/*
+ * Keystore lock -- lock call blocks indefinitely.
+ */
+
+WEAK_FUNCTION void hal_ks_lock(void)
+{
+  return;
+}
+
+WEAK_FUNCTION void hal_ks_unlock(void)
+{
+  return;
+}
+
+/*
+ * Local variables:
+ * indent-tabs-mode: nil
+ * End:
+ */