dm: mei: add guid handling functions

libuuid sports only uuid (big endian encoding),
though mei requires guids (little endian encoding).
The base types are based on <linux/uuid.h> header.

Tracked-On: #1536
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Acked-by: Wang, Yu1 <yu1.wang@intel.com>

devicemodel/hw/pci/virtio/virtio_mei.c

@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2018 Intel Corporation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+/*
+ * MEI device virtualization.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/queue.h>
+#include <sys/uio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stddef.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <dirent.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <assert.h>
+#include <pthread.h>
+#include <time.h>
+
+#include <linux/uuid.h>
+#include <linux/mei.h>
+
+#include "types.h"
+#include "vmmapi.h"
+#include "mevent.h"
+#include "pci_core.h"
+#include "virtio.h"
+#include "dm.h"
+
+#include "mei.h"
+
+#ifndef UUID_STR_LEN
+#define UUID_STR_LEN 37
+#endif
+
+#ifndef GUID_INIT
+#define GUID_INIT(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7) \
+	UUID_LE(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7)
+#endif
+
+static int guid_parse(const char *str, size_t maxlen, guid_t *guid)
+{
+	const char *p = "00000000-0000-0000-0000-000000000000";
+	const size_t len = strnlen(p, UUID_STR_LEN);
+	uint32_t a;
+	uint16_t b, c;
+	uint8_t d[2], e[6];
+	char buf[3];
+	unsigned int i;
+
+	if (strnlen(str, maxlen) != len)
+		return -1;
+
+	for (i = 0; i < len; i++) {
+		if (str[i] == '-') {
+			if (p[i] == '-')
+				continue;
+			else
+				return -1;
+		} else if (!isxdigit(str[i])) {
+			return -1;
+		}
+	}
+
+	a = strtoul(str +  0, NULL, 16);
+	b = strtoul(str +  9, NULL, 16);
+	c = strtoul(str + 14, NULL, 16);
+
+	buf[2] = 0;
+	for (i = 0; i < 2; i++) {
+		buf[0] = str[19 + i * 2];
+		buf[1] = str[19 + i * 2 + 1];
+		d[i] = strtoul(buf, NULL, 16);
+	}
+
+	for (i = 0; i < 6; i++) {
+		buf[0] = str[24 + i * 2];
+		buf[1] = str[24 + i * 2 + 1];
+		e[i] = strtoul(buf, NULL, 16);
+	}
+
+	*guid = GUID_INIT(a, b, c,
+			  d[0], d[1], e[0], e[1], e[2], e[3], e[4], e[5]);
+
+	return 0;
+}
+
+static int guid_unparse(const guid_t *guid, char *str, size_t len)
+{
+	unsigned int i;
+	size_t pos = 0;
+
+	if (len < UUID_STR_LEN)
+		return -EINVAL;
+
+	pos += snprintf(str + pos, len - pos, "%02x", guid->b[3]);
+	pos += snprintf(str + pos, len - pos, "%02x", guid->b[2]);
+	pos += snprintf(str + pos, len - pos, "%02x", guid->b[1]);
+	pos += snprintf(str + pos, len - pos, "%02x", guid->b[0]);
+	str[pos] = '-';
+	pos++;
+	pos += snprintf(str + pos, len - pos, "%02x", guid->b[5]);
+	pos += snprintf(str + pos, len - pos, "%02x", guid->b[4]);
+	str[pos] = '-';
+	pos++;
+	pos += snprintf(str + pos, len - pos, "%02x", guid->b[7]);
+	pos += snprintf(str + pos, len - pos, "%02x", guid->b[6]);
+	str[pos] = '-';
+	pos++;
+	pos += snprintf(str + pos, len - pos, "%02x", guid->b[8]);
+	pos += snprintf(str + pos, len - pos, "%02x", guid->b[9]);
+	str[pos] = '-';
+	pos++;
+	for (i = 10; i < 16; i++)
+		pos += snprintf(str + pos, len - pos, "%02x", guid->b[i]);
+
+	return 0;
+}
+