net: added ng_nomac module

sys/Makefile

@@ -86,6 +86,9 @@ endif
 ifneq (,$(filter nhdp,$(USEMODULE)))
     DIRS += net/routing/nhdp
 endif
+ifneq (,$(filter ng_nomac,$(USEMODULE)))
+    DIRS += net/link_layer/ng_nomac
+endif
 
 DIRS += $(dir $(wildcard $(addsuffix /Makefile, ${USEMODULE})))
 

sys/include/net/ng_nomac.h

@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2015 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @defgroup    net_nomac Simplest possible MAC layer
+ * @ingroup     net
+ * @brief       Simplest possible MAC protocol that sends without considering
+ *              the state of the medium
+ * @{
+ *
+ * @file
+ * @brief       Interface definition for the NOMAC MAC layer
+ *
+ * @author      Hauke Petersen <[email protected]>
+ */
+
+#ifndef NG_NOMAC_H_
+#define NG_NOMAC_H_
+
+#include "kernel.h"
+#include "net/ng_netdev.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief   Set the default message queue size for NOMAC layers
+ */
+#ifndef NG_NOMAC_MSG_QUEUE_SIZE
+#define NG_NOMAC_MSG_QUEUE_SIZE         (8U)
+#endif
+
+/**
+ * @brief   Initialize an instance of the NOMAC layer
+ *
+ * The initialization starts a new thread that connects to the given netdev
+ * device and starts a link layer event loop.
+ *
+ * @param[in] stack         stack for the control thread
+ * @param[in] stacksize     size of *stack*
+ * @param[in] priority      priority for the thread housing the NOMAC instance
+ * @param[in] name          name of the thread housing the NOMAC instance
+ * @param[in] dev           netdev device, needs to be already initialized
+ *
+ * @return                  PID of NOMAC thread on success
+ * @return                  -EINVAL if creation of thread fails
+ * @return                  -ENODEV if *dev* is invalid
+ */
+kernel_pid_t ng_nomac_init(char *stack, int stacksize, char priority,
+                           const char *name, ng_netdev_t *dev);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __NOMAC_H_ */
+/** @} */

sys/net/link_layer/ng_nomac/Makefile

@@ -0,0 +1 @@
+include $(RIOTBASE)/Makefile.base

sys/net/link_layer/ng_nomac/ng_nomac.c

@@ -0,0 +1,157 @@
+/*
+ * Copyright (C) 2015 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @{
+ * @ingroup     net_nomac
+ * @file
+ * @brief       Implementation of the NOMAC MAC protocol
+ *
+ * @author      Hauke Petersen <[email protected]>
+ * @}
+ */
+
+#include <errno.h>
+
+#include "kernel.h"
+#include "msg.h"
+#include "thread.h"
+#include "net/ng_nomac.h"
+#include "net/ng_netreg.h"
+#include "net/ng_pkt.h"
+#include "net/ng_nettype.h"
+#include "net/ng_netdev.h"
+#include "net/ng_netapi.h"
+#include "net/ng_netif.h"
+#include "net/ng_pktbuf.h"
+
+#define ENABLE_DEBUG    (0)
+#include "debug.h"
+
+/**
+ * @brief   Function called by the device driver on device events
+ *
+ * @param[in] event         type of event
+ * @param[in] data          optional parameter
+ */
+static void _event_cb(ng_netdev_event_t event, void *data)
+{
+    DEBUG("nomac: event triggered -> %i\n", event);
+    /* NOMAC only understands the RX_COMPLETE event... */
+    if (event == NETDEV_EVENT_RX_COMPLETE) {
+        ng_pktsnip_t *pkt;
+        ng_netreg_entry_t *sendto;
+
+        /* get pointer to the received packet */
+        pkt = (ng_pktsnip_t *)data;
+        /* find out, who to send the packet to */
+        sendto = ng_netreg_lookup(pkt->type, NG_NETREG_DEMUX_CTX_ALL);
+        /* throw away packet if no one is interested */
+        if (sendto == NULL) {
+            DEBUG("nomac: unable to forward packet of type %i\n", pkt->type);
+            ng_pktbuf_release(pkt);
+        }
+        /* send the packet to everyone interested in it's type */
+        ng_pktbuf_hold(pkt, ng_netreg_num(pkt->type, NG_NETREG_DEMUX_CTX_ALL) - 1);
+        while (sendto != NULL) {
+            DEBUG("nomac: sending pkt %p to PID %u\n", pkt, sendto->pid);
+            ng_netapi_send(sendto->pid, pkt);
+            sendto = ng_netreg_getnext(sendto);
+        }
+    }
+}
+
+/**
+ * @brief   Startup code and event loop of the NOMAC layer
+ *
+ * @param[in] args          expects a pointer to the underlying netdev device
+ *
+ * @return                  never returns
+ */
+static void *_nomac_thread(void *args)
+{
+    ng_netdev_t *dev = (ng_netdev_t *)args;
+    ng_netapi_opt_t *opt;
+    int res;
+    msg_t msg, reply, msg_queue[NG_NOMAC_MSG_QUEUE_SIZE];
+
+    /* setup the MAC layers message queue */
+    msg_init_queue(msg_queue, NG_NOMAC_MSG_QUEUE_SIZE);
+    /* save the PID to the device descriptor and register the device */
+    dev->mac_pid = thread_getpid();
+    ng_netif_add(dev->mac_pid);
+    /* register the event callback with the device driver */
+    dev->driver->add_event_callback(dev, _event_cb);
+
+    /* start the event loop */
+    while (1) {
+        DEBUG("nomac: waiting for incoming messages\n");
+        msg_receive(&msg);
+        /* dispatch NETDEV and NETAPI messages */
+        switch (msg.type) {
+            case NG_NETDEV_MSG_TYPE_EVENT:
+                DEBUG("nomac: NG_NETDEV_MSG_TYPE_EVENT received\n");
+                dev->driver->isr_event(dev, msg.content.value);
+                break;
+            case NG_NETAPI_MSG_TYPE_SND:
+                DEBUG("nomac: NG_NETAPI_MSG_TYPE_SND received\n");
+                dev->driver->send_data(dev, (ng_pktsnip_t *)msg.content.ptr);
+                break;
+            case NG_NETAPI_MSG_TYPE_SET:
+                /* TODO: filter out MAC layer options -> for now forward
+                         everything to the device driver */
+                DEBUG("nomac: NG_NETAPI_MSG_TYPE_SET received\n");
+                /* read incoming options */
+                opt = (ng_netapi_opt_t *)msg.content.ptr;
+                /* set option for device driver */
+                res = dev->driver->set(dev, opt->opt, opt->data, opt->data_len);
+                /* send reply to calling thread */
+                reply.type = NG_NETAPI_MSG_TYPE_ACK;
+                reply.content.value = (uint32_t)res;
+                msg_reply(&msg, &reply);
+                break;
+            case NG_NETAPI_MSG_TYPE_GET:
+                /* TODO: filter out MAC layer options -> for now forward
+                         everything to the device driver */
+                DEBUG("nomac: NG_NETAPI_MSG_TYPE_GET received\n");
+                /* read incoming options */
+                opt = (ng_netapi_opt_t *)msg.content.ptr;
+                /* get option from device driver */
+                res = dev->driver->get(dev, opt->opt, opt->data,
+                                       (size_t*)(&(opt->data_len)));
+                /* send reply to calling thread */
+                reply.type = NG_NETAPI_MSG_TYPE_ACK;
+                reply.content.value = (uint32_t)res;
+                msg_reply(&msg, &reply);
+                break;
+            default:
+                DEBUG("nomac: Unknown command %" PRIu16 "\n", msg.type);
+                break;
+        }
+    }
+    /* never reached */
+    return NULL;
+}
+
+kernel_pid_t ng_nomac_init(char *stack, int stacksize, char priority,
+                        const char *name, ng_netdev_t *dev)
+{
+    kernel_pid_t res;
+
+    /* check if given netdev device is defined and the driver is set */
+    if (dev == NULL || dev->driver == NULL) {
+        return -ENODEV;
+    }
+    /* create new NOMAC thread */
+    res = thread_create(stack, stacksize, priority, CREATE_STACKTEST,
+                         _nomac_thread, (void *)dev, name);
+    if (res <= 0) {
+        return -EINVAL;
+    }
+    return res;
+}