A work-in-progress rework of the Contiki MAC and radio layers. The

main ideas are:

* Separates the Contiki low-layer network stack into four layers:
  network (e.g. sicslowpan / rime), Medium Access Control MAC
  (e.g. CSMA), Radio Duty Cycling RDC (e.g. ContikiMAC, X-MAC), and
  radio (e.g. cc2420).
* Introduces a new way to configure the network stack. Four #defines
  that specify what mechanism/protocol/driver to use at the four
  layers: NETSTACK_CONF_NETWORK, NETSTACK_CONF_MAC, NETSTACK_CONF_RDC,
  NETSTACK_CONF_RADIO.
* Adds a callback mechanism to inform the MAC and network layers about
  the fate of a transmitted packet: if the packet was not possible to
  transmit, the cause of the failure is reported, and if the packets
  was successfully transmitted, the number of tries before it was
  finally transmitted is reported.
* NULL-protocols at both the MAC and RDC layers: nullmac and nullrdc,
  which can be used when MAC and RDC functionality is not needed.
* Extends the radio API with three new functions that enable more
  efficient radio duty cycling protocols: channel check, pending
  packet, and receiving packet.
* New initialization mechanism, which takes advantage of the NETSTACK
  #defines.

core/net/sicslowpan.c

@@ -32,7 +32,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: sicslowpan.c,v 1.17 2010/02/08 21:59:21 adamdunkels Exp $
+ * $Id: sicslowpan.c,v 1.18 2010/02/18 21:48:39 adamdunkels Exp $
  */
 /**
  * \file
@@ -54,6 +54,7 @@
 #include "net/uip-netif.h"
 #include "net/rime.h"
 #include "net/sicslowpan.h"
+#include "net/netstack.h"
 
 #define DEBUG 0
 #if DEBUG
@@ -1110,11 +1111,9 @@ send_packet(rimeaddr_t *dest)
    */
   packetbuf_set_addr(PACKETBUF_ADDR_RECEIVER, dest);
 
-  if(sicslowpan_mac != NULL) {
-  /** \todo: Fix sending delays so they aren't blocking, or even better would
-   *         be to figure out how to get rid of delays entirely */
-    sicslowpan_mac->send();
-  }
+  /* XXX we should provide a callback function that is called when the
+     packet is sent. For now, we just supply a NULL pointer. */
+  NETSTACK_MAC.send(NULL, NULL);
 
   /* If we are sending multiple packets in a row, we need to let the
      watchdog know that we are still alive. */
@@ -1295,7 +1294,7 @@ output(uip_lladdr_t *localdest)
  * (it is a SHALL in the RFC 4944 and should never happen)
  */
 static void
-input(const struct mac_driver *r)
+input(void)
 {
   /* size of the IP packet (read from fragment) */
   u16_t frag_size = 0;
@@ -1306,12 +1305,6 @@ input(const struct mac_driver *r)
   u16_t frag_tag = 0;
 #endif /*SICSLOWPAN_CONF_FRAG*/
 
-#ifdef SICSLOWPAN_CONF_CONVENTIONAL_MAC
-  if(r->read() <= 0) {
-    return;
-  }
-#endif /* SICSLOWPAN_CONF_CONVENTIONAL_MAC */
-
   /* init */
   uncomp_hdr_len = 0;
   rime_hdr_len = 0;
@@ -1477,7 +1470,6 @@ input(const struct mac_driver *r)
 #if SICSLOWPAN_CONF_FRAG
   }
 #endif /* SICSLOWPAN_CONF_FRAG */
-  return;
 }
 /** @} */
 
@@ -1485,14 +1477,11 @@ input(const struct mac_driver *r)
 /* \brief 6lowpan init function (called by the MAC layer)             */
 /*--------------------------------------------------------------------*/
 void
-sicslowpan_init(const struct mac_driver *m)
+sicslowpan_init(void)
 {
   /* remember the mac driver */
-  sicslowpan_mac = m;
+  sicslowpan_mac = &NETSTACK_MAC;
  
-  /* Set our input function as the receive function of the MAC. */
-  sicslowpan_mac->set_receive_function(input);
-
   /*
    * Set out output function as the function to be called from uIP to
    * send a packet.
@@ -1529,4 +1518,14 @@ sicslowpan_init(const struct mac_driver *m)
 #endif /*SICSLOWPAN_CONF_COMPRESSION == SICSLOWPAN_CONF_COMPRESSION_HC01*/
 }
 /*--------------------------------------------------------------------*/
+const struct mac_driver sicslowpan_driver = {
+  "Rime",
+  sicslowpan_init,
+  NULL,
+  input,
+  NULL,
+  NULL,
+  NULL,
+};
+/*--------------------------------------------------------------------*/
 /** @} */