trusty: coverage: Add UUID helpers

Function to parse string was borrowed from Trusty.

Bug: 171750250
Test: trusty_test_fuzzer
Change-Id: I8430579f142db2c174874aff373bce6bb868de31

trusty/coverage/Android.bp

@@ -21,12 +21,14 @@ cc_library {
     vendor_available: true,
     srcs: [
         "coverage.cpp",
+        "uuid.cpp",
     ],
     export_include_dirs: [
         "include",
     ],
     shared_libs: [
         "libbase",
+        "libext2_uuid",
         "liblog",
         "libdmabufheap",
         "libtrusty",

trusty/coverage/include/trusty/coverage/tipc.h

@@ -19,16 +19,10 @@
 #pragma once
 
 #include <stdint.h>
+#include <trusty/coverage/uuid.h>
 
 #define COVERAGE_CLIENT_PORT "com.android.trusty.coverage.client"
 
-struct uuid {
-    uint32_t time_low;
-    uint16_t time_mid;
-    uint16_t time_hi_and_version;
-    uint8_t clock_seq_and_node[8];
-};
-
 enum coverage_client_cmd {
     COVERAGE_CLIENT_CMD_RESP_BIT = 1U,
     COVERAGE_CLIENT_CMD_SHIFT = 1U,

trusty/coverage/include/trusty/coverage/uuid.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+struct uuid {
+    uint32_t time_low;
+    uint16_t time_mid;
+    uint16_t time_hi_and_version;
+    uint8_t clock_seq_and_node[8];
+};
+
+/**
+ * str_to_uuid() - Converts a C string into a uuid
+ * @str: C-string representation of the uuid
+ * @uuid: &struct uuid to fill with the converted uuid
+ *
+ * Return: true on success, false otherwise
+ */
+bool str_to_uuid(const char* str, struct uuid* uuid);

trusty/coverage/uuid.cpp

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2021 The Android Open Sourete Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <string.h>
+#include <trusty/coverage/uuid.h>
+#include <uuid.h>
+
+#include <stdio.h>
+
+static uint16_t reverse_u16(uint16_t u) {
+    return u << 8 | u >> 8;
+}
+
+static uint32_t reverse_u32(uint32_t u) {
+    return reverse_u16((uint16_t)u) << 16 | reverse_u16(u >> 16);
+}
+
+bool str_to_uuid(const char* str, struct uuid* uuid) {
+    uuid_t uu;
+    static_assert(sizeof(uu) == sizeof(*uuid));
+
+    if (uuid_parse(str, uu)) {
+        return false;
+    }
+
+    memcpy(uuid, uu, sizeof(*uuid));
+    uuid->time_low = reverse_u32(uuid->time_low);
+    uuid->time_mid = reverse_u16(uuid->time_mid);
+    uuid->time_hi_and_version = reverse_u16(uuid->time_hi_and_version);
+    return true;
+}