failed approach

gomspace/libgscsp/src/transaction.c

@@ -0,0 +1,67 @@
+/* Copyright (c) 2013-2017 GomSpace A/S. All rights reserved. */
+
+#include <gs/csp/csp.h>
+#include <gs/util/check.h>
+
+gs_error_t gs_csp_transaction_persistent(csp_conn_t * conn, uint32_t timeout,  const void * tx_buf,
+                                         size_t tx_len, void * rx_buf, size_t rx_max_len, size_t * rx_len)
+{
+    GS_CHECK_HANDLE(conn != NULL);
+
+    size_t size = (rx_max_len > tx_len) ? rx_max_len : tx_len;
+    csp_packet_t * packet = csp_buffer_get(size);
+    if (packet == NULL) {
+        return GS_ERROR_ALLOC;
+    }
+
+    /* Copy the request */
+    if (tx_len > 0 && tx_buf != NULL) {
+        memcpy(packet->data, tx_buf, tx_len);
+    }
+
+    packet->length = tx_len;
+
+    if (!csp_send(conn, packet, timeout)) {
+        csp_buffer_free(packet);
+        return GS_ERROR_IO;
+    }
+
+    /* If no reply is expected, return now */
+    if (rx_max_len == 0) {
+        return GS_OK;
+    }
+
+    packet = csp_read(conn, timeout);
+    if (packet == NULL) {
+        return GS_ERROR_IO;
+    }
+
+    gs_error_t return_val;
+    if (rx_max_len >= packet->length) {
+        size = packet->length;
+        return_val = GS_OK;
+    } else {
+        csp_log_error("Reply length %u, buffer only %u", packet->length, rx_max_len);
+        size = rx_max_len;
+        return_val = GS_ERROR_OVERFLOW;
+    }
+    memcpy(rx_buf, packet->data, size);
+    *rx_len = packet->length;
+    csp_buffer_free(packet);
+    return return_val;
+}
+
+gs_error_t gs_csp_transaction2(uint8_t prio, uint8_t dest, uint8_t port, uint32_t timeout, const void * tx_buf,
+                               size_t tx_len, void * rx_buf, size_t rx_max_len, size_t * rx_len, uint32_t opts)
+{
+    csp_conn_t * conn = csp_connect(prio, dest, port, 0, opts);
+    if (conn == NULL) {
+        return GS_ERROR_HANDLE;
+    }
+
+    gs_error_t res = gs_csp_transaction_persistent(conn, timeout, tx_buf, tx_len, rx_buf, rx_max_len, rx_len);
+
+    csp_close(conn);
+
+    return res;
+}