From: Wilfred Mallawa <wilfred.mallawa@wdc.com>

This is to support uni-directional transports such as SPDM over Storage.
As specified by the DMTF DSP0286.

Also update spdm_socket_rsp() to use the new send()/receive() functions. For
the case of spdm_socket_receive(), this allows us to do error checking
in one place with the addition of spdm_socket_command_valid().

Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 backends/spdm-socket.c       | 56 ++++++++++++++++++++++++++++--------
 include/system/spdm-socket.h | 32 +++++++++++++++++++++
 2 files changed, 76 insertions(+), 12 deletions(-)

diff --git a/backends/spdm-socket.c b/backends/spdm-socket.c
index 2c709c68c8..ab74a02d9c 100644
--- a/backends/spdm-socket.c
+++ b/backends/spdm-socket.c
@@ -184,29 +184,61 @@ int spdm_socket_connect(uint16_t port, Error **errp)
     return client_socket;
 }
 
-uint32_t spdm_socket_rsp(const int socket, uint32_t transport_type,
-                         void *req, uint32_t req_len,
-                         void *rsp, uint32_t rsp_len)
+static bool spdm_socket_command_valid(uint32_t command)
+{
+    switch (command) {
+    case SPDM_SOCKET_COMMAND_NORMAL:
+    case SPDM_SOCKET_STORAGE_CMD_IF_SEND:
+    case SPDM_SOCKET_STORAGE_CMD_IF_RECV:
+    case SOCKET_SPDM_STORAGE_ACK_STATUS:
+    case SPDM_SOCKET_COMMAND_OOB_ENCAP_KEY_UPDATE:
+    case SPDM_SOCKET_COMMAND_CONTINUE:
+    case SPDM_SOCKET_COMMAND_SHUTDOWN:
+    case SPDM_SOCKET_COMMAND_UNKOWN:
+    case SPDM_SOCKET_COMMAND_TEST:
+        return true;
+    default:
+        return false;
+    }
+}
+
+uint32_t spdm_socket_receive(const int socket, uint32_t transport_type,
+                             void *rsp, uint32_t rsp_len)
 {
     uint32_t command;
     bool result;
 
-    result = send_platform_data(socket, transport_type,
-                                SPDM_SOCKET_COMMAND_NORMAL,
-                                req, req_len);
-    if (!result) {
+    result = receive_platform_data(socket, transport_type, &command,
+                                   (uint8_t *)rsp, &rsp_len);
+
+    /* we may have received some data, but check if the command is valid */
+    if (!result || !spdm_socket_command_valid(command)) {
         return 0;
     }
 
-    result = receive_platform_data(socket, transport_type, &command,
-                                   (uint8_t *)rsp, &rsp_len);
+    return rsp_len;
+}
+
+bool spdm_socket_send(const int socket, uint32_t socket_cmd,
+                      uint32_t transport_type, void *req, uint32_t req_len)
+{
+    return send_platform_data(socket, transport_type, socket_cmd, req,
+                              req_len);
+}
+
+uint32_t spdm_socket_rsp(const int socket, uint32_t transport_type,
+                         void *req, uint32_t req_len,
+                         void *rsp, uint32_t rsp_len)
+{
+    bool result;
+
+    result = spdm_socket_send(socket, SPDM_SOCKET_COMMAND_NORMAL,
+                              transport_type, req, req_len);
     if (!result) {
         return 0;
     }
 
-    assert(command != 0);
-
-    return rsp_len;
+    return spdm_socket_receive(socket, transport_type, rsp, rsp_len);
 }
 
 void spdm_socket_close(const int socket, uint32_t transport_type)
diff --git a/include/system/spdm-socket.h b/include/system/spdm-socket.h
index 5d8bd9aa4e..29aa04fd52 100644
--- a/include/system/spdm-socket.h
+++ b/include/system/spdm-socket.h
@@ -50,6 +50,35 @@ uint32_t spdm_socket_rsp(const int socket, uint32_t transport_type,
                          void *req, uint32_t req_len,
                          void *rsp, uint32_t rsp_len);
 
+/**
+ * spdm_socket_rsp: Receive a message from an SPDM server
+ * @socket: socket returned from spdm_socket_connect()
+ * @transport_type: SPDM_SOCKET_TRANSPORT_TYPE_* macro
+ * @rsp: response buffer
+ * @rsp_len: response buffer length
+ *
+ * Receives a message from the SPDM server and returns the number of bytes
+ * received or 0 on failure. This can be used to receive a message from the SPDM
+ * server without sending anything first.
+ */
+uint32_t spdm_socket_receive(const int socket, uint32_t transport_type,
+                             void *rsp, uint32_t rsp_len);
+
+/**
+ * spdm_socket_rsp: Sends a message to an SPDM server
+ * @socket: socket returned from spdm_socket_connect()
+ * @socket_cmd: socket command type (normal/if_recv/if_send etc...)
+ * @transport_type: SPDM_SOCKET_TRANSPORT_TYPE_* macro
+ * @req: request buffer
+ * @req_len: request buffer length
+ *
+ * Sends platform data to a SPDM server on socket, returns true on success.
+ * The response from the server must then be fetched by using
+ * spdm_socket_receive().
+ */
+bool spdm_socket_send(const int socket, uint32_t socket_cmd,
+                      uint32_t transport_type, void *req, uint32_t req_len);
+
 /**
  * spdm_socket_close: send a shutdown command to the server
  * @socket: socket returned from spdm_socket_connect()
@@ -60,6 +89,9 @@ uint32_t spdm_socket_rsp(const int socket, uint32_t transport_type,
 void spdm_socket_close(const int socket, uint32_t transport_type);
 
 #define SPDM_SOCKET_COMMAND_NORMAL                0x0001
+#define SPDM_SOCKET_STORAGE_CMD_IF_SEND           0x0002
+#define SPDM_SOCKET_STORAGE_CMD_IF_RECV           0x0003
+#define SOCKET_SPDM_STORAGE_ACK_STATUS            0x0004
 #define SPDM_SOCKET_COMMAND_OOB_ENCAP_KEY_UPDATE  0x8001
 #define SPDM_SOCKET_COMMAND_CONTINUE              0xFFFD
 #define SPDM_SOCKET_COMMAND_SHUTDOWN              0xFFFE
-- 
2.51.0