start of ctaphid

ctaphid.c

@@ -0,0 +1,109 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "ctaphid.h"
+#include "time.h"
+
+typedef enum
+{
+    IDLE = 0,
+    HANDLING_REQUEST,
+} CTAP_STATE;
+
+static int state;
+static int active_cid;
+static uint64_t active_cid_timestamp;
+static uint8_t ctap_buffer[CTAPHID_BUFFER_SIZE];
+
+void ctaphid_init()
+{
+    state = IDLE;
+    active_cid = 0;
+    active_cid_timestamp = millis();
+}
+
+uint32_t get_new_cid()
+{
+    static uint32_t cid = 1;
+    return cid++;
+}
+
+static int is_broadcast(CTAPHID_PACKET * pkt)
+{
+    return (pkt->cid == CTAPHID_BROADCAST_CID);
+}
+
+static int is_init_pkt(CTAPHID_PACKET * pkt)
+{
+    return (pkt->pkt.init.cmd == CTAPHID_INIT);
+}
+
+static int is_active_cid(CTAPHID_PACKET * pkt)
+{
+    return (pkt->cid == active_cid);
+}
+
+static int is_timed_out()
+{
+    return (millis() - active_cid_timestamp > 500);
+}
+
+
+
+void ctaphid_handle_packet(uint8_t * pkt_raw)
+{
+/*HID_MESSAGE_SIZE*/
+    CTAPHID_PACKET * pkt = (CTAPHID_PACKET *)(pkt_raw);
+
+    printf("Recv packet\n");
+    printf("  CID: %08x\n", pkt->cid);
+    printf("  cmd: %02x\n", pkt->pkt.init.cmd);
+    printf("  length: %d\n", ctaphid_packet_len(pkt));
+
+start_over:
+
+    switch (state)
+    {
+        case IDLE:
+            if (is_broadcast(pkt))
+            {
+                printf("starting a new request\n");
+                state = HANDLING_REQUEST;
+                active_cid = get_new_cid();
+                active_cid_timestamp = millis();
+            }
+            else
+            {
+                printf("Error, unknown request\n");
+            }
+            break;
+        case HANDLING_REQUEST:
+            if (is_active_cid(pkt))
+            {
+                if (is_init_pkt(pkt))
+                {
+                    printf("received abort request from %08x\n", pkt->cid);
+                    ctaphid_init();
+
+                }
+                active_cid_timestamp = millis();
+            }
+            else if (is_timed_out())
+            {
+                ctaphid_init();
+                goto start_over;
+            }
+            else
+            {
+                printf("Too busy with current transaction\n");
+            }
+            break;
+        default:
+            printf("invalid state\n");
+            exit(1);
+    }
+
+}
+
+
+