1 files changed, 250 insertions, 0 deletions
diff --git a/lib/smbios-parser.c b/lib/smbios-parser.c
new file mode 100644
index 00000000000..9a62b3c760d
--- /dev/null
+++ b/lib/smbios-parser.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020, Bachmann electronic GmbH
+ */
+
+#define LOG_CATEGORY	LOGC_BOOT
+
+#include <errno.h>
+#include <smbios.h>
+#include <string.h>
+#include <tables_csum.h>
+#include <linux/kernel.h>
+
+const struct smbios_entry *smbios_entry(u64 address, u32 size)
+{
+	const struct smbios_entry *entry = (struct smbios_entry *)(uintptr_t)address;
+
+	if (!address || !size)
+		return NULL;
+
+	if (memcmp(entry->anchor, "_SM_", 4))
+		return NULL;
+
+	if (table_compute_checksum(entry, entry->length))
+		return NULL;
+
+	return entry;
+}
+
+static u8 *find_next_header(u8 *pos)
+{
+	/* search for _double_ NULL bytes */
+	while (!((*pos == 0) && (*(pos + 1) == 0)))
+		pos++;
+
+	/* step behind the double NULL bytes */
+	pos += 2;
+
+	return pos;
+}
+
+static struct smbios_header *get_next_header(const struct smbios_header *curr)
+{
+	u8 *pos = ((u8 *)curr) + curr->length;
+
+	return (struct smbios_header *)find_next_header(pos);
+}
+
+const struct smbios_header *smbios_header(const struct smbios_entry *entry, int type)
+{
+	const unsigned int num_header = entry->struct_count;
+	const struct smbios_header *header = (struct smbios_header *)((uintptr_t)entry->struct_table_address);
+
+	for (unsigned int i = 0; i < num_header; i++) {
+		if (header->type == type)
+			return header;
+
+		header = get_next_header(header);
+	}
+
+	return NULL;
+}
+
+static char *string_from_smbios_table(const struct smbios_header *header,
+				      int idx)
+{
+	unsigned int i = 1;
+	u8 *pos;
+
+	if (!header)
+		return NULL;
+
+	pos = ((u8 *)header) + header->length;
+
+	while (i < idx) {
+		if (*pos == 0x0)
+			i++;
+
+		pos++;
+	}
+
+	return (char *)pos;
+}
+
+char *smbios_string(const struct smbios_header *header, int index)
+{
+	if (!header)
+		return NULL;
+
+	return string_from_smbios_table(header, index);
+}
+
+int smbios_update_version_full(void *smbios_tab, const char *version)
+{
+	const struct smbios_header *hdr;
+	struct smbios_type0 *bios;
+	uint old_len, len;
+	char *ptr;
+
+	log_info("Updating SMBIOS table at %p\n", smbios_tab);
+	hdr = smbios_header(smbios_tab, SMBIOS_BIOS_INFORMATION);
+	if (!hdr)
+		return log_msg_ret("tab", -ENOENT);
+	bios = (struct smbios_type0 *)hdr;
+	ptr = smbios_string(hdr, bios->bios_ver);
+	if (!ptr)
+		return log_msg_ret("str", -ENOMEDIUM);
+
+	/*
+	 * This string is supposed to have at least enough bytes and is
+	 * padded with spaces. Update it, taking care not to move the
+	 * \0 terminator, so that other strings in the string table
+	 * are not disturbed. See smbios_add_string()
+	 */
+	old_len = strnlen(ptr, SMBIOS_STR_MAX);
+	len = strnlen(version, SMBIOS_STR_MAX);
+	if (len > old_len)
+		return log_ret(-ENOSPC);
+
+	log_debug("Replacing SMBIOS type 0 version string '%s'\n", ptr);
+	memcpy(ptr, version, len);
+#ifdef LOG_DEBUG
+	print_buffer((ulong)ptr, ptr, 1, old_len + 1, 0);
+#endif
+
+	return 0;
+}
+
+struct smbios_filter_param {
+	u32 offset;
+	u32 size;
+	bool is_string;
+};
+
+struct smbios_filter_table {
+	int type;
+	struct smbios_filter_param *params;
+	u32 count;
+};
+
+struct smbios_filter_param smbios_type1_filter_params[] = {
+	{offsetof(struct smbios_type1, serial_number),
+	 FIELD_SIZEOF(struct smbios_type1, serial_number), true},
+	{offsetof(struct smbios_type1, uuid),
+	 FIELD_SIZEOF(struct smbios_type1, uuid), false},
+	{offsetof(struct smbios_type1, wakeup_type),
+	 FIELD_SIZEOF(struct smbios_type1, wakeup_type), false},
+};
+
+struct smbios_filter_param smbios_type2_filter_params[] = {
+	{offsetof(struct smbios_type2, serial_number),
+	 FIELD_SIZEOF(struct smbios_type2, serial_number), true},
+	{offsetof(struct smbios_type2, chassis_location),
+	 FIELD_SIZEOF(struct smbios_type2, chassis_location), false},
+};
+
+struct smbios_filter_param smbios_type3_filter_params[] = {
+	{offsetof(struct smbios_type3, serial_number),
+	 FIELD_SIZEOF(struct smbios_type3, serial_number), true},
+	{offsetof(struct smbios_type3, asset_tag_number),
+	 FIELD_SIZEOF(struct smbios_type3, asset_tag_number), true},
+};
+
+struct smbios_filter_param smbios_type4_filter_params[] = {
+	{offsetof(struct smbios_type4, serial_number),
+	 FIELD_SIZEOF(struct smbios_type4, serial_number), true},
+	{offsetof(struct smbios_type4, asset_tag),
+	 FIELD_SIZEOF(struct smbios_type4, asset_tag), true},
+	{offsetof(struct smbios_type4, part_number),
+	 FIELD_SIZEOF(struct smbios_type4, part_number), true},
+	{offsetof(struct smbios_type4, core_count),
+	 FIELD_SIZEOF(struct smbios_type4, core_count), false},
+	{offsetof(struct smbios_type4, core_enabled),
+	 FIELD_SIZEOF(struct smbios_type4, core_enabled), false},
+	{offsetof(struct smbios_type4, thread_count),
+	 FIELD_SIZEOF(struct smbios_type4, thread_count), false},
+	{offsetof(struct smbios_type4, core_count2),
+	 FIELD_SIZEOF(struct smbios_type4, core_count2), false},
+	{offsetof(struct smbios_type4, core_enabled2),
+	 FIELD_SIZEOF(struct smbios_type4, core_enabled2), false},
+	{offsetof(struct smbios_type4, thread_count2),
+	 FIELD_SIZEOF(struct smbios_type4, thread_count2), false},
+	{offsetof(struct smbios_type4, voltage),
+	 FIELD_SIZEOF(struct smbios_type4, voltage), false},
+};
+
+struct smbios_filter_table smbios_filter_tables[] = {
+	{SMBIOS_SYSTEM_INFORMATION, smbios_type1_filter_params,
+	 ARRAY_SIZE(smbios_type1_filter_params)},
+	{SMBIOS_BOARD_INFORMATION, smbios_type2_filter_params,
+	 ARRAY_SIZE(smbios_type2_filter_params)},
+	{SMBIOS_SYSTEM_ENCLOSURE, smbios_type3_filter_params,
+	 ARRAY_SIZE(smbios_type3_filter_params)},
+	{SMBIOS_PROCESSOR_INFORMATION, smbios_type4_filter_params,
+	 ARRAY_SIZE(smbios_type4_filter_params)},
+};
+
+static void clear_smbios_table(struct smbios_header *header,
+			       struct smbios_filter_param *filter,
+			       u32 count)
+{
+	u32 i;
+	char *str;
+	u8 string_id;
+
+	for (i = 0; i < count; i++) {
+		if (filter[i].is_string) {
+			string_id = *((u8 *)header + filter[i].offset);
+			if (string_id == 0) /* string is empty */
+				continue;
+
+			str = smbios_string(header, string_id);
+			if (!str)
+				continue;
+
+			/* string is cleared to space, keep '\0' terminator */
+			memset(str, ' ', strlen(str));
+
+		} else {
+			memset((void *)((u8 *)header + filter[i].offset),
+			       0, filter[i].size);
+		}
+	}
+}
+
+void smbios_prepare_measurement(const struct smbios3_entry *entry,
+				struct smbios_header *smbios_copy)
+{
+	u32 i, j;
+	void *table_end;
+	struct smbios_header *header;
+
+	table_end = (void *)((u8 *)smbios_copy + entry->table_maximum_size);
+
+	for (i = 0; i < ARRAY_SIZE(smbios_filter_tables); i++) {
+		header = smbios_copy;
+		for (j = 0; (void *)header < table_end; j++) {
+			if (header->type == smbios_filter_tables[i].type)
+				break;
+
+			header = get_next_header(header);
+		}
+		if ((void *)header >= table_end)
+			continue;
+
+		clear_smbios_table(header,
+				   smbios_filter_tables[i].params,
+				   smbios_filter_tables[i].count);
+	}
+}