net: initial import of an IPv6 neighbor cache

Makefile.dep

@@ -48,6 +48,10 @@ ifneq (,$(filter sixlowpan,$(USEMODULE)))
 	USEMODULE += vtimer
 endif
 
+ifneq (,$(filter ng_ipv6_nc,$(USEMODULE)))
+    USEMODULE += ng_ipv6_addr
+endif
+
 ifneq (,$(filter aodvv2,$(USEMODULE)))
         USEMODULE += vtimer
         USEMODULE += sixlowpan

sys/Makefile

@@ -65,6 +65,9 @@ endif
 ifneq (,$(filter ng_ipv6_addr,$(USEMODULE)))
     DIRS += net/network_layer/ng_ipv6/addr
 endif
+ifneq (,$(filter ng_ipv6_nc,$(USEMODULE)))
+    DIRS += net/network_layer/ng_ipv6/nc
+endif
 ifneq (,$(filter ng_netapi,$(USEMODULE)))
     DIRS += net/crosslayer/ng_netapi
 endif

sys/include/net/ng_ipv6/nc.h

@@ -0,0 +1,220 @@
+/*
+ * Copyright (C) 2015 Martine Lenders <[email protected]>
+ *
+ * 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_ng_ipv6_nc  IPv6 neighbor cache
+ * @ingroup     net_ng_ipv6
+ * @brief       Translates IPv6 addresses to link layer addresses.
+ * @{
+ *
+ * @file
+ * @brief       Neighbor cache definitions.
+ *
+ * @author      Martine Lenders <[email protected]>
+ */
+
+#ifndef NG_IPV6_NC_H_
+#define NG_IPV6_NC_H_
+
+#include <stdint.h>
+
+#include "kernel_types.h"
+#include "net/ng_ipv6/addr.h"
+#include "net/ng_netif.h"
+#include "net/ng_pktqueue.h"
+#include "timex.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef NG_IPV6_NC_SIZE
+/**
+ * @brief   The size of the neighbor cache
+ */
+#define NG_IPV6_NC_SIZE             (NG_NETIF_NUMOF * 8)
+#endif
+
+#ifndef NG_IPV6_NC_L2_ADDR_MAX
+/**
+ * @brief   The maximum size of a link layer address
+ */
+#define NG_IPV6_NC_L2_ADDR_MAX      (8)
+#endif
+
+/**
+ * @{
+ * @name Flag definitions for ng_ipv6_nc_t
+ */
+/**
+ * @{
+ * @brief   States of a neighbor cache entry.
+ *
+ * @see <a href="http://tools.ietf.org/html/rfc4861#section-7.3.2">
+ *          RFC 4861, section 7.3.2
+ *      </a>
+ */
+#define NG_IPV6_NC_STATE_MASK           (0x07)  /**< Mask for neighbor cache state */
+#define NG_IPV6_NC_STATE_POS            (0)     /**< Shift of neighbor cache state */
+
+#define NG_IPV6_NC_STATE_UNMANAGED      (0x00)  /**< The entry is not manage by NDP */
+
+/**
+ * @brief The entry is unreachable
+ *
+ * @see <a href="http://tools.ietf.org/html/rfc7048#section-3">
+ *          RFC 7048, section 3
+ *      </a>
+ */
+#define NG_IPV6_NC_STATE_UNREACHABLE    (0x01)
+#define NG_IPV6_NC_STATE_INCOMPLETE     (0x02)  /**< Address resolution is performed */
+#define NG_IPV6_NC_STATE_STALE          (0x03)  /**< The entry is stale */
+#define NG_IPV6_NC_STATE_DELAY          (0x04)  /**< The entry was stale but packet was sent out */
+#define NG_IPV6_NC_STATE_PROBE          (0x05)  /**< Periodic reachabality confirmation */
+#define NG_IPV6_NC_STATE_REACHABLE      (0x07)  /**< The entry is reachable */
+/**
+ * @}
+ */
+
+#define NG_IPV6_NC_IS_ROUTER            (0x08)  /**< The neighbor is a router */
+
+#define NG_IPV6_NC_TYPE_MASK            (0x30)  /**< Mask for neighbor cache state */
+#define NG_IPV6_NC_TYPE_POS             (4)     /**< Shift of neighbor cache state */
+
+/**
+ * @{
+ * @brief   States of a neighbor cache entry.
+ *
+ * @see <a href="http://tools.ietf.org/html/rfc6775#section-3.5">
+ *          RFC 6775, section 3.5
+ *      </a>
+ */
+/**
+ * @brief The entry has no type
+ *
+ * @details The node sents multicast Neighbor Solicitations for hosts.
+ */
+#define NG_IPV6_NC_TYPE_NONE            (0x00)
+#define NG_IPV6_NC_TYPE_GC              (0x10)  /**< The entry is marked for removal */
+#define NG_IPV6_NC_TYPE_TENTATIVE       (0x20)  /**< The entry is temporary */
+#define NG_IPV6_NC_TYPE_REGISTERED      (0x30)  /**< The entry is registered */
+/**
+ * @}
+ */
+/**
+ * @}
+ */
+
+/**
+ * @brief   Neighbor cache entry as defined in
+ *          <a href="http://tools.ietf.org/html/rfc4861#section-5.1">
+ *              RFC 4861, section 5.1
+ *          </a>.
+ */
+typedef struct {
+    ng_pktqueue_t pkts;                     /**< Packets waiting for address resolution */
+    ng_ipv6_addr_t ipv6_addr;               /**< IPv6 address of the neighbor */
+    uint8_t l2_addr[NG_IPV6_NC_L2_ADDR_MAX];/**< Link layer address of the neighbor */
+    uint8_t l2_addr_len;                    /**< Length of ng_ipv6_nc_t::l2_addr */
+    uint8_t flags;                          /**< Flags as defined above */
+    kernel_pid_t iface;                     /**< PID to the interface where the neighbor is */
+} ng_ipv6_nc_t;
+
+/**
+ * @brief   Initializes neighbor cache
+ */
+void ng_ipv6_nc_init(void);
+
+/**
+ * @brief   Adds a neighbor to the neighbor cache
+ *
+ * @param[in] iface         PID to the interface where the neighbor is.
+ *                          Must not be KERNEL_PID_UNDEF.
+ * @param[in] ipv6_addr     IPv6 address of the neighbor. Must not be NULL.
+ * @param[in] l2_addr       Link layer address of the neighbor. NULL if unknown.
+ * @param[in] l2_addr_len   Length of @p l2_addr, must be lesser than or equal
+ *                          to NG_IPV6_L2_ADDR_MAX. 0 if unknown.
+ * @param[in] flags         Flags for the entry
+ *
+ * @return  0 on success
+ * @return  -EADDRINUSE, if @p ipv6_addr is already registered to the neighbor
+ *          cache.
+ * @return  -EFAULT, if @p ipv6_addr was NULL.
+ * @return  -EINVAL, if @p l2_addr_len is greater then @ref NG_IPV6_NC_L2_ADDR_MAX,
+ *          @p ipv6_addr is unspecified or @p iface is KERNEL_PID_UNDEF.
+ * @return  -ENOMEM, if no space is left to store entry.
+ */
+int ng_ipv6_nc_add(kernel_pid_t iface, const ng_ipv6_addr_t *ipv6_addr,
+                   const void *l2_addr, size_t l2_addr_len, uint8_t flags);
+
+/**
+ * @brief   Removes a neighbor from the neighbor cache
+ *
+ * @param[in] iface         PID to the interface where the neighbor is. If it
+ *                          is KERNEL_PID_UNDEF it will be removed for all
+ *                          interfaces.
+ * @param[in] ipv6_addr     IPv6 address of the neighbor
+ */
+void ng_ipv6_nc_remove(kernel_pid_t iface, const ng_ipv6_addr_t *ipv6_addr);
+
+/**
+ * @brief   Searches for any neighbor cache entry fitting the @p ipv6_addr.
+ *
+ * @param[in] iface         PID to the interface where the neighbor is. If it
+ *                          is KERNEL_PID_UNDEF it will be searched on all
+ *                          interfaces.
+ * @param[in] ipv6_addr     An IPv6 address
+ *
+ * @return  The neighbor cache entry, if one is found.
+ * @return  NULL, if none is found.
+ */
+ng_ipv6_nc_t *ng_ipv6_nc_get(kernel_pid_t iface, const ng_ipv6_addr_t *ipv6_addr);
+
+/**
+ * @brief   Searches for any neighbor cache entry fitting the @p ipv6_addr,
+ *          where you currently can send a packet to (do not confuse with
+ *          NG_IPV6_NC_STATE_REACHABLE).
+ *
+ * @param[in] iface         PID to the interface where the neighbor is. If it
+ *                          is KERNEL_PID_UNDEF it will be searched on all
+ *                          interfaces.
+ * @param[in] ipv6_addr     An IPv6 address
+ *
+ * @return  The neighbor cache entry, if one is found.
+ * @return  NULL, if none is found.
+ */
+ng_ipv6_nc_t *ng_ipv6_nc_get_reachable(kernel_pid_t iface,
+                                       const ng_ipv6_addr_t *ipv6_addr);
+
+/**
+ * @brief   Marks an entry as still reachable, if one with a fitting @p ipv6_addr
+ *          can be found.
+ *
+ * @details This function can be used by upper layer protocols for neighbor
+ *          discovery optimization to confirm that there was a reachability
+ *          confirmation (e. g. an ACK in TCP) from the neighbor.
+ *
+ * @see <a href="http://tools.ietf.org/html/rfc4861#section-7.3.1">
+ *          RFC 4861, section 7.3.1
+ *      </a>
+ *
+ * @param[in] ipv6_addr     An IPv6 address
+ *
+ * @return  The neighbor cache entry, if one is found.
+ * @return  NULL, if none is found.
+ */
+ng_ipv6_nc_t *ng_ipv6_nc_still_reachable(const ng_ipv6_addr_t *ipv6_addr);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NG_IPV6_NC_H_ */
+/**
+ * @}
+ */

sys/net/network_layer/ng_ipv6/nc/Makefile

@@ -0,0 +1,3 @@
+MODULE = ng_ipv6_nc
+
+include $(RIOTBASE)/Makefile.base