base: GetTID responder implementation

A pldm terminus is defined as the point of communication termination
for PLDM messages and the PLDM functions associated with those messages.

The Terminus ID(TID) is a value that identifies a PLDM terminus.

This commit assignes 1 to the BMC as the TID.

Signed-off-by: John Wang <wangzqbj@inspur.com>
Change-Id: I7adb0e1274f326fe6cf148771f230f530c9a567c
diff --git a/libpldm/base.c b/libpldm/base.c
index 36df1b0..5927ba1 100644
--- a/libpldm/base.c
+++ b/libpldm/base.c
@@ -322,3 +322,48 @@
 
 	return PLDM_SUCCESS;
 }
+
+int encode_get_tid_resp(uint8_t instance_id, uint8_t completion_code,
+			uint8_t tid, struct pldm_msg *msg)
+{
+	if (msg == NULL) {
+		return PLDM_ERROR_INVALID_DATA;
+	}
+
+	struct pldm_get_tid_resp *response =
+	    (struct pldm_get_tid_resp *)msg->payload;
+
+	response->completion_code = completion_code;
+	struct pldm_header_info header = {0};
+	header.instance = instance_id;
+	header.msg_type = PLDM_RESPONSE;
+	header.command = PLDM_GET_TID;
+	pack_pldm_header(&header, &(msg->hdr));
+
+	response->tid = tid;
+
+	return PLDM_SUCCESS;
+}
+
+int decode_get_tid_resp(const struct pldm_msg *msg, size_t payload_length,
+			uint8_t *completion_code, uint8_t *tid)
+{
+	if (msg == NULL || tid == NULL || completion_code == NULL) {
+		return PLDM_ERROR_INVALID_DATA;
+	}
+
+	if (payload_length != PLDM_GET_TID_RESP_BYTES) {
+		return PLDM_ERROR_INVALID_LENGTH;
+	}
+
+	struct pldm_get_tid_resp *response =
+	    (struct pldm_get_tid_resp *)msg->payload;
+	*completion_code = response->completion_code;
+	if (PLDM_SUCCESS != *completion_code) {
+		return PLDM_SUCCESS;
+	};
+
+	*tid = response->tid;
+
+	return PLDM_SUCCESS;
+}
diff --git a/libpldm/base.h b/libpldm/base.h
index f15ca7e..d30a300 100644
--- a/libpldm/base.h
+++ b/libpldm/base.h
@@ -23,6 +23,7 @@
 /** @brief PLDM Commands
  */
 enum pldm_supported_commands {
+	PLDM_GET_TID = 0x2,
 	PLDM_GET_PLDM_VERSION = 0x3,
 	PLDM_GET_PLDM_TYPES = 0x4,
 	PLDM_GET_PLDM_COMMANDS = 0x5
@@ -73,6 +74,7 @@
 
 /* Response lengths are inclusive of completion code */
 #define PLDM_GET_TYPES_RESP_BYTES 9
+#define PLDM_GET_TID_RESP_BYTES 2
 #define PLDM_GET_COMMANDS_RESP_BYTES 33
 /* Response data has only one version and does not contain the checksum */
 #define PLDM_GET_VERSION_RESP_BYTES 10
@@ -181,6 +183,16 @@
 	uint8_t version_data[1];       //!< PLDM GetVersion version field
 } __attribute__((packed));
 
+/** @struct pldm_get_tid_resp
+ *
+ *  Structure representing PLDM get tid response.
+ */
+
+struct pldm_get_tid_resp {
+	uint8_t completion_code; //!< completion code
+	uint8_t tid;		 //!< PLDM GetTID TID field
+} __attribute__((packed));
+
 /**
  * @brief Populate the PLDM message with the PLDM header.The caller of this API
  *        allocates buffer for the PLDM header when forming the PLDM message.
@@ -292,6 +304,19 @@
 			    uint32_t *next_transfer_handle,
 			    uint8_t *transfer_flag, ver32_t *version);
 
+/* GetTID */
+
+/** @brief Decode a GetTID response message
+ *
+ *  @param[in] msg - Response message
+ *  @param[in] payload_length - Length of response message payload
+ *  @param[out] completion_code - Pointer to response msg's PLDM completion code
+ *  @param[out] tid - Pointer to the terminus id
+ *  @return pldm_completion_codes
+ */
+int decode_get_tid_resp(const struct pldm_msg *msg, size_t payload_length,
+			uint8_t *completion_code, uint8_t *tid);
+
 /* Responder */
 
 /* GetPLDMTypes */
@@ -371,6 +396,21 @@
 			   uint32_t *transfer_handle, uint8_t *transfer_opflag,
 			   uint8_t *type);
 
+/* GetTID */
+
+/** @brief Create a PLDM response message for GetTID
+ *
+ *  @param[in] instance_id - Message's instance id
+ *  @param[in] completion_code - PLDM completion code
+ *  @param[in] tid - Terminus ID
+ *  @param[in,out] msg - Message will be written to this
+ *  @return pldm_completion_codes
+ *  @note  Caller is responsible for memory alloc and dealloc of param
+ *         'msg.payload'
+ */
+int encode_get_tid_resp(uint8_t instance_id, uint8_t completion_code,
+			uint8_t tid, struct pldm_msg *msg);
+
 #ifdef __cplusplus
 }
 #endif