added code to support FEC networking

2013-12-23 12:55:19 +00:00
parent a5e20fdd1c
commit 2763966f4c
11 changed files with 759 additions and 96 deletions
--- a/net/udp.c
+++ b/net/udp.c
@@ -0,0 +1,180 @@
+/*
+ * File:        udp.c
+ * Purpose:     User Datagram Protocol driver
+ *
+ * Notes:
+ *
+ * Modifications:
+ *
+ */
+#include "bas_types.h"
+#include "net.h"
+
+#ifdef DBUG_NETWORK
+
+/********************************************************************/
+typedef struct
+{
+    uint16_t port;
+    void (*handler)(NIF *, NBUF *);
+} UDP_BOUND_PORT;
+
+/********************************************************************/
+
+#define UDP_MAX_PORTS   (5)     /* plenty for this implementation */
+
+
+static UDP_BOUND_PORT
+udp_port_table[UDP_MAX_PORTS];
+
+static uint16
+udp_port;
+
+/********************************************************************/
+void
+udp_init (void)
+{
+    int index;
+
+    for (index = 0; index < UDP_MAX_PORTS; ++index)
+    {
+        udp_port_table[index].port = 0;
+    }
+
+    udp_port = DEFAULT_UDP_PORT;    /* next free port */
+}
+/********************************************************************/
+void
+udp_prime_port (uint16 init_port)
+{
+    udp_port = init_port;
+}
+/********************************************************************/
+void
+udp_bind_port (uint16 port, void (*handler)(NIF *, NBUF *))
+{
+    int index;
+
+    for (index = 0; index < UDP_MAX_PORTS; ++index)
+    {
+        if (udp_port_table[index].port == 0)
+        {
+            udp_port_table[index].port = port;
+            udp_port_table[index].handler = handler;
+            return;
+        }
+    }
+}
+/********************************************************************/
+void
+udp_free_port (uint16 port)
+{
+    int index;
+
+    for (index = 0; index < UDP_MAX_PORTS; ++index)
+    {
+        if (udp_port_table[index].port == port)
+        {
+            udp_port_table[index].port = 0;
+            return;
+        }
+    }
+}
+/********************************************************************/
+static void *
+udp_port_handler (uint16 port)
+{
+    int index;
+
+    for (index = 0; index < UDP_MAX_PORTS; ++index)
+    {
+        if (udp_port_table[index].port == port)
+        {
+            return (void *)udp_port_table[index].handler;
+        }
+    }
+    return NULL;
+}
+/********************************************************************/
+uint16
+udp_obtain_free_port (void)
+{
+    uint16 port;
+
+    port = udp_port;
+    if (--udp_port <= 255)
+        udp_port = DEFAULT_UDP_PORT;
+
+    return port;
+}
+/********************************************************************/
+int
+udp_send ( NIF *nif, uint8 *dest, int sport, int dport, NBUF *pNbuf)
+{
+    /*
+     * This function takes data and creates a UDP frame and
+     * passes it onto the IP layer
+     */
+    udp_frame_hdr   *udpframe;
+
+    udpframe = (udp_frame_hdr *)&pNbuf->data[UDP_HDR_OFFSET];
+
+    /* Set UDP source port */
+    udpframe->src_port = (uint16)sport;
+
+    /* Set UDP destination port */
+    udpframe->dest_port = (uint16)dport;
+
+    /* Set length */
+    udpframe->length = (uint16)(pNbuf->length + UDP_HDR_SIZE);
+
+    /* No checksum calcualation needed */
+    udpframe->chksum = (uint16)0;
+
+    /* Add the length of the UDP packet to the total length of the packet */
+    pNbuf->length += 8;
+
+    return (ip_send(nif,
+                    dest,
+                    ip_get_myip(nif_get_protocol_info(nif,ETH_FRM_IP)),
+                    IP_PROTO_UDP,
+                    pNbuf));
+}
+/********************************************************************/
+void
+udp_handler (NIF *nif, NBUF *pNbuf)
+{
+    /*
+     * This function handles incoming UDP packets
+     */
+    udp_frame_hdr   *udpframe;
+    void (*handler)(NIF *, NBUF *);
+
+    udpframe = (udp_frame_hdr *)&pNbuf->data[pNbuf->offset];
+
+    /*
+     * Adjust the length and valid data offset of the packet we are
+     * passing on
+     */
+    pNbuf->length -= UDP_HDR_SIZE;
+    pNbuf->offset += UDP_HDR_SIZE;
+
+    /*
+     * Traverse the list of bound ports to see if there is a higher
+     * level protocol to pass the packet on to
+     */
+    if ((handler = (void(*)(NIF*,NBUF*))udp_port_handler(UDP_DEST(udpframe))) != NULL)
+        handler(nif, pNbuf);
+    else
+    {
+        #ifdef DBUG_PRINT
+            printf("Received UDP packet for non-supported port\n");
+        #endif
+        nbuf_free(pNbuf);
+    }
+
+    return;
+}
+/********************************************************************/
+
+#endif /* #ifdef DBUG_NETWORK */