bios: Implement an iterator for bios attribute table
Traversing bios attribute table should be platform-independent, so
implement a c-version bios attribute table iterator in libpldm, also
implement a c++ auxiliary function to traverse a bios table.
Signed-off-by: John Wang <wangzqbj@inspur.com>
Change-Id: I2afcaac306603410e711aa4772ba35b5e0b131d5
diff --git a/libpldm/bios_table.c b/libpldm/bios_table.c
new file mode 100644
index 0000000..26d30bf
--- /dev/null
+++ b/libpldm/bios_table.c
@@ -0,0 +1,199 @@
+#include <assert.h>
+#include <endian.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "bios.h"
+#include "bios_table.h"
+
+#define POINTER_CHECK(pointer) \
+ do { \
+ if (pointer == NULL) \
+ return PLDM_ERROR_INVALID_DATA; \
+ } while (0)
+
+#define ATTR_TYPE_EXPECT(type, expected) \
+ do { \
+ if (type != expected && type != (expected | 0x80)) \
+ return PLDM_ERROR_INVALID_DATA; \
+ } while (0)
+
+uint8_t pldm_bios_table_attr_entry_enum_decode_pv_num(
+ const struct pldm_bios_attr_table_entry *entry)
+{
+ return entry->metadata[0];
+}
+
+int pldm_bios_table_attr_entry_enum_decode_pv_num_check(
+ const struct pldm_bios_attr_table_entry *entry, uint8_t *pv_num)
+{
+ POINTER_CHECK(entry);
+ POINTER_CHECK(pv_num);
+ ATTR_TYPE_EXPECT(entry->attr_type, PLDM_BIOS_ENUMERATION);
+ *pv_num = pldm_bios_table_attr_entry_enum_decode_pv_num(entry);
+ return PLDM_SUCCESS;
+}
+
+uint8_t pldm_bios_table_attr_entry_enum_decode_def_num(
+ const struct pldm_bios_attr_table_entry *entry)
+{
+ uint8_t pv_num = pldm_bios_table_attr_entry_enum_decode_pv_num(entry);
+ return entry->metadata[sizeof(uint8_t) /* pv_num */ +
+ sizeof(uint16_t) * pv_num];
+}
+
+int pldm_bios_table_attr_entry_enum_decode_def_num_check(
+ const struct pldm_bios_attr_table_entry *entry, uint8_t *def_num)
+{
+ POINTER_CHECK(entry);
+ POINTER_CHECK(def_num);
+ ATTR_TYPE_EXPECT(entry->attr_type, PLDM_BIOS_ENUMERATION);
+ *def_num = pldm_bios_table_attr_entry_enum_decode_def_num(entry);
+ return PLDM_SUCCESS;
+}
+
+/** @brief Get length of an enum attribute entry
+ */
+static size_t
+attr_table_entry_length_enum(const struct pldm_bios_attr_table_entry *entry)
+{
+ uint8_t pv_num = pldm_bios_table_attr_entry_enum_decode_pv_num(entry);
+ uint8_t def_num = pldm_bios_table_attr_entry_enum_decode_def_num(entry);
+ return sizeof(*entry) - 1 + sizeof(pv_num) + pv_num * sizeof(uint16_t) +
+ sizeof(def_num) + def_num;
+}
+
+#define ATTR_ENTRY_STRING_LENGTH_MIN \
+ sizeof(uint8_t) /* string type */ + \
+ sizeof(uint16_t) /* minimum string length */ + \
+ sizeof(uint16_t) /* maximum string length */ + \
+ sizeof(uint16_t) /* default string length */
+
+uint16_t pldm_bios_table_attr_entry_string_decode_def_string_length(
+ const struct pldm_bios_attr_table_entry *entry)
+{
+ int def_string_pos = ATTR_ENTRY_STRING_LENGTH_MIN - sizeof(uint16_t);
+ uint16_t def_string_length =
+ *(uint16_t *)(entry->metadata + def_string_pos);
+ return le16toh(def_string_length);
+}
+
+int pldm_bios_table_attr_entry_string_decode_def_string_length_check(
+ const struct pldm_bios_attr_table_entry *entry, uint16_t *def_string_length)
+{
+ POINTER_CHECK(entry);
+ POINTER_CHECK(def_string_length);
+ ATTR_TYPE_EXPECT(entry->attr_type, PLDM_BIOS_STRING);
+ *def_string_length =
+ pldm_bios_table_attr_entry_string_decode_def_string_length(entry);
+ return PLDM_SUCCESS;
+}
+
+/** @brief Get length of a string attribute entry
+ */
+static size_t
+attr_table_entry_length_string(const struct pldm_bios_attr_table_entry *entry)
+{
+ uint16_t def_string_len =
+ pldm_bios_table_attr_entry_string_decode_def_string_length(entry);
+ return sizeof(*entry) - 1 + ATTR_ENTRY_STRING_LENGTH_MIN +
+ def_string_len;
+}
+
+struct attr_table_entry {
+ uint8_t attr_type;
+ size_t (*entry_length_handler)(
+ const struct pldm_bios_attr_table_entry *);
+};
+
+static struct attr_table_entry attr_table_entrys[] = {
+ {.attr_type = PLDM_BIOS_ENUMERATION,
+ .entry_length_handler = attr_table_entry_length_enum},
+ {.attr_type = PLDM_BIOS_ENUMERATION_READ_ONLY,
+ .entry_length_handler = attr_table_entry_length_enum},
+ {.attr_type = PLDM_BIOS_STRING,
+ .entry_length_handler = attr_table_entry_length_string},
+ {.attr_type = PLDM_BIOS_STRING_READ_ONLY,
+ .entry_length_handler = attr_table_entry_length_string},
+};
+
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
+
+static struct attr_table_entry *find_attr_table_entry_by_type(uint8_t attr_type)
+{
+ size_t i;
+ for (i = 0; i < ARRAY_SIZE(attr_table_entrys); i++) {
+ if (attr_type == attr_table_entrys[i].attr_type)
+ return &attr_table_entrys[i];
+ }
+ return NULL;
+}
+
+static size_t attr_table_entry_length(const void *table_entry)
+{
+ const struct pldm_bios_attr_table_entry *entry = table_entry;
+ struct attr_table_entry *attr_table_entry =
+ find_attr_table_entry_by_type(entry->attr_type);
+ assert(attr_table_entry != NULL);
+ assert(attr_table_entry->entry_length_handler != NULL);
+
+ return attr_table_entry->entry_length_handler(entry);
+}
+
+struct pldm_bios_table_iter {
+ const uint8_t *table_data;
+ size_t table_len;
+ size_t current_pos;
+ size_t (*entry_length_handler)(const void *table_entry);
+};
+
+struct pldm_bios_table_iter *
+pldm_bios_table_iter_create(const void *table, size_t length,
+ enum pldm_bios_table_types type)
+{
+ struct pldm_bios_table_iter *iter = malloc(sizeof(*iter));
+ assert(iter != NULL);
+ iter->table_data = table;
+ iter->table_len = length;
+ iter->current_pos = 0;
+ iter->entry_length_handler = NULL;
+ switch (type) {
+ case PLDM_BIOS_STRING_TABLE:
+ break;
+ case PLDM_BIOS_ATTR_TABLE:
+ iter->entry_length_handler = attr_table_entry_length;
+ break;
+ case PLDM_BIOS_ATTR_VAL_TABLE:
+ break;
+ }
+
+ return iter;
+}
+
+void pldm_bios_table_iter_free(struct pldm_bios_table_iter *iter)
+{
+ free(iter);
+}
+
+#define pad_and_check_max 7
+bool pldm_bios_table_iter_is_end(const struct pldm_bios_table_iter *iter)
+{
+ if (iter->table_len - iter->current_pos <= pad_and_check_max)
+ return true;
+ return false;
+}
+
+void pldm_bios_table_iter_next(struct pldm_bios_table_iter *iter)
+{
+ if (pldm_bios_table_iter_is_end(iter))
+ return;
+ const void *entry = iter->table_data + iter->current_pos;
+ iter->current_pos += iter->entry_length_handler(entry);
+}
+
+const void *pldm_bios_table_iter_value(struct pldm_bios_table_iter *iter)
+{
+ return iter->table_data + iter->current_pos;
+}
\ No newline at end of file