sys/net/gnrc: added XBee-to-GNRC glue code

sys/include/net/gnrc/netdev2/xbee_adpt.h

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+/**
+ * @addtogroup  net_gnrc
+ * @{
+ *
+ * @file
+ * @brief       GNRC to XBee netdev2 glue code interface
+ *
+ * Although the XBee devices are IEEE802.15.4 transceivers, use their own
+ * proprietary format for communicating between the host CPU and the device over
+ * UART. The XBee device driver expects the data to send to be given in this
+ * format, hence we need to introduce an XBee specific adaption layer that
+ * translates between GNRC and the XBee proprietary header format.
+ *
+ * For this custom header format, we can not make use of the existing adaption
+ * layers for other IEEE802.15.4 devices.
+ *
+ * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
+ */
+
+#ifndef GNRC_NETDEV2_XBEE_ADPT_H_
+#define GNRC_NETDEV2_XBEE_ADPT_H_
+
+#include "xbee.h"
+#include "net/gnrc/netdev2.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief   Initialize GNRC handler for netdev2 XBee devices
+ *
+ * @param[out] gnrc_netdev2     gnrc_netdev2 struct to initialize
+ * @param[in]  dev              XBee device to handle
+ */
+void gnrc_netdev2_xbee_init(gnrc_netdev2_t *gnrc_netdev2, xbee_t *dev);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GNRC_NETDEV2_XBEE_ADPT_H_ */
+/** @} */

sys/net/gnrc/link_layer/netdev2/gnrc_netdev2_xbee.c

@@ -0,0 +1,182 @@
+/*
+ * Copyright (C) 2016 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_gnrc
+ * @{
+ *
+ * @file
+ * @brief       GNRC to netdev adapter for XBee devices
+ *
+ * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
+ *
+ * @}
+ */
+
+#include "assert.h"
+#include "xbee.h"
+#include "net/gnrc.h"
+#include "net/gnrc/netdev2/xbee_adpt.h"
+
+#define ENABLE_DEBUG    (0)
+#include "debug.h"
+
+#define BCAST   (GNRC_NETIF_HDR_FLAGS_BROADCAST | GNRC_NETIF_HDR_FLAGS_MULTICAST)
+
+static gnrc_pktsnip_t *xbee_adpt_recv(gnrc_netdev2_t *gnrc_netdev2)
+{
+    netdev2_t *dev = gnrc_netdev2->dev;
+    int pktlen;
+    int xhdr_len;
+    gnrc_pktsnip_t *payload;
+    gnrc_pktsnip_t *netif_snip;
+    gnrc_pktsnip_t *xhdr_snip;
+    gnrc_netif_hdr_t *netif;
+    xbee_l2hdr_t l2hdr;
+
+    assert(dev);
+
+    /* see how much data there is to process */
+    pktlen = dev->driver->recv(dev, NULL, 0, NULL);
+    if (pktlen <= 0) {
+        DEBUG("[xbee-gnrc] recv: no data available to process\n");
+        return NULL;
+    }
+
+    /* allocate space for the packet in the pktbuf */
+    payload = gnrc_pktbuf_add(NULL, NULL, pktlen, XBEE_DEFAULT_PROTOCOL);
+    if (payload == NULL) {
+        DEBUG("[xbee-gnrc] recv: unable to allocate space in the pktbuf\n");
+        /* tell the driver to drop the packet */
+        dev->driver->recv(dev, NULL, 1, NULL);
+        return NULL;
+    }
+
+    /* copy the complete including the XBee header into the packet buffer */
+    dev->driver->recv(dev, payload->data, pktlen, NULL);
+
+    /* try to parse the L2 header data from the XBee header */
+    xhdr_len = xbee_parse_hdr((xbee_t *)dev, (uint8_t *)payload->data, &l2hdr);
+    if (xhdr_len < 0) {
+        DEBUG("[xbee-gnrc] recv: unable to parse XBee header\n");
+        gnrc_pktbuf_release(payload);
+        return NULL;
+    }
+
+    /* crop the XBee header from the payload */
+    xhdr_snip = gnrc_pktbuf_mark(payload, xhdr_len, GNRC_NETTYPE_UNDEF);
+    if (xhdr_snip == NULL) {
+        DEBUG("[xbee-gnrc] recv: unable to mark XBee header snip\n");
+        gnrc_pktbuf_release(payload);
+        return NULL;
+    }
+    gnrc_pktbuf_remove_snip(payload, xhdr_snip);
+
+    /* create a netif hdr from the obtained data */
+    netif_snip = gnrc_netif_hdr_build(l2hdr.src_addr, l2hdr.addr_len,
+                                      l2hdr.dst_addr, l2hdr.addr_len);
+    if (netif_snip == NULL) {
+        DEBUG("[xbee-gnrc] recv: unable to allocate netif header\n");
+        gnrc_pktbuf_release(payload);
+        return NULL;
+    }
+    netif = (gnrc_netif_hdr_t *)netif_snip->data;
+    netif->if_pid = gnrc_netdev2->pid;
+    netif->rssi = l2hdr.rssi;
+    if (l2hdr.bcast) {
+        netif->flags = GNRC_NETIF_HDR_FLAGS_BROADCAST;
+    }
+
+    DEBUG("[xbee-gnrc] recv: successfully parsed packet\n");
+
+    /* and append the netif header */
+    LL_APPEND(payload, netif_snip);
+
+    return payload;
+}
+
+static int xbee_adpt_send(gnrc_netdev2_t *dev, gnrc_pktsnip_t *pkt)
+{
+    int res;
+    size_t size;
+    size_t count;
+    gnrc_pktsnip_t *vec;
+    gnrc_netif_hdr_t *hdr;
+    uint8_t xhdr[XBEE_MAX_TXHDR_LENGTH];
+
+    /* check device descriptor and packet */
+    assert(dev && pkt);
+
+    /* get the payload size and the dst address details */
+    size = gnrc_pkt_len(pkt->next);
+    DEBUG("[xbee-gnrc] send: payload of packet is %i\n", (int)size);
+    hdr = (gnrc_netif_hdr_t *)pkt->data;
+    if (hdr->flags & BCAST) {
+        uint16_t addr = 0xffff;
+        res = xbee_build_hdr((xbee_t *)dev, xhdr, size, &addr, 2);
+        DEBUG("[xbee-gnrc] send: preparing to send broadcast\n");
+    }
+    else {
+        uint8_t *addr = gnrc_netif_hdr_get_dst_addr(hdr);
+        res = xbee_build_hdr((xbee_t *)dev, xhdr, size, addr, hdr->dst_l2addr_len);
+        if (res < 0) {
+            if (res == -EOVERFLOW) {
+                DEBUG("[xbee-gnrc] send: payload length exceeds max limit\n");
+            }
+            else if (res == -ENOMSG) {
+                DEBUG("[xbee-gnrc] send: invalid destination l2 address\n");
+            }
+            return res;
+        }
+        if (hdr->dst_l2addr_len == IEEE802154_SHORT_ADDRESS_LEN) {
+            DEBUG("[xbee-gnrc] send: preparing to send unicast to %02x:%02x\n",
+                  (int)addr[0], (int)addr[1]);
+        }
+        else {
+            DEBUG("[xbee-gnrc] send: preparing to send unicast to "
+                  "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
+                  (int)addr[0], (int)addr[1], (int)addr[2], (int)addr[3],
+                  (int)addr[4], (int)addr[5], (int)addr[6], (int)addr[7]);
+        }
+    }
+
+    /* now let's extract the iovector and send out the stuff */
+    vec = gnrc_pktbuf_get_iovec(pkt, &count);
+    if (vec != NULL) {
+        pkt = vec;
+        struct iovec *vector = (struct iovec *)pkt->data;
+        vector[0].iov_base = xhdr;
+        vector[0].iov_len = res;
+#ifdef MODULE_NETSTATS_L2
+        if (hdr->flags & BCAST) {
+            dev->dev->stats.tx_mcast_count++;
+        }
+        else {
+            dev->dev->stats.tx_unicast_count++;
+        }
+#endif
+        DEBUG("[xbee-gnrc] send: triggering the drivers send function\n");
+        res = dev->dev->driver->send(dev->dev, vector, count);
+    }
+    else {
+        DEBUG("[xbee-gnrc] send: unable to create iovec\n");
+    }
+
+    gnrc_pktbuf_release(pkt);
+
+    return res;
+}
+
+void gnrc_netdev2_xbee_init(gnrc_netdev2_t *gnrc_netdev2, xbee_t *dev)
+{
+    assert(gnrc_netdev2 && dev);
+
+    gnrc_netdev2->send = xbee_adpt_send;
+    gnrc_netdev2->recv = xbee_adpt_recv;
+    gnrc_netdev2->dev = (netdev2_t *)dev;
+}