commit a4a41b9023ef5b3a7c4a1cd82fb167fc63e706df Author: goldsimon <goldsimon@gmx.de> Date: Wed Sep 26 21:50:42 2012 +0200 - This also brings in LwIP's IPv6 codebase Signed-off-by: Tomas Hruby <tom@minix3.org>
1785 lines
56 KiB
C
1785 lines
56 KiB
C
/**
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* @file
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*
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* Neighbor discovery and stateless address autoconfiguration for IPv6.
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* Aims to be compliant with RFC 4861 (Neighbor discovery) and RFC 4862
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* (Address autoconfiguration).
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*/
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/*
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* Copyright (c) 2010 Inico Technologies Ltd.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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* OF SUCH DAMAGE.
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*
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* This file is part of the lwIP TCP/IP stack.
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*
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* Author: Ivan Delamer <delamer@inicotech.com>
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*
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*
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* Please coordinate changes and requests with Ivan Delamer
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* <delamer@inicotech.com>
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*/
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#include "lwip/opt.h"
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#if LWIP_IPV6 /* don't build if not configured for use in lwipopts.h */
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#include "lwip/nd6.h"
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#include "lwip/pbuf.h"
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#include "lwip/mem.h"
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#include "lwip/memp.h"
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#include "lwip/ip6.h"
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#include "lwip/ip6_addr.h"
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#include "lwip/inet_chksum.h"
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#include "lwip/netif.h"
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#include "lwip/icmp6.h"
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#include "lwip/mld6.h"
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#include "lwip/stats.h"
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#include <string.h>
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/* Router tables. */
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struct nd6_neighbor_cache_entry neighbor_cache[LWIP_ND6_NUM_NEIGHBORS];
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struct nd6_destination_cache_entry destination_cache[LWIP_ND6_NUM_DESTINATIONS];
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struct nd6_prefix_list_entry prefix_list[LWIP_ND6_NUM_PREFIXES];
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struct nd6_router_list_entry default_router_list[LWIP_ND6_NUM_ROUTERS];
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/* Default values, can be updated by a RA message. */
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u32_t reachable_time = LWIP_ND6_REACHABLE_TIME;
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u32_t retrans_timer = LWIP_ND6_RETRANS_TIMER; /* TODO implement this value in timer */
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/* Index for cache entries. */
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static u8_t nd6_cached_neighbor_index;
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static u8_t nd6_cached_destination_index;
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/* Multicast address holder. */
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static ip6_addr_t multicast_address;
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/* Static buffer to parse RA packet options (size of a prefix option, biggest option) */
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static u8_t nd6_ra_buffer[sizeof(struct prefix_option)];
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/* Forward declarations. */
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static s8_t nd6_find_neighbor_cache_entry(ip6_addr_t * ip6addr);
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static s8_t nd6_new_neighbor_cache_entry(void);
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static void nd6_free_neighbor_cache_entry(s8_t i);
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static s8_t nd6_find_destination_cache_entry(ip6_addr_t * ip6addr);
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static s8_t nd6_new_destination_cache_entry(void);
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static s8_t nd6_is_prefix_in_netif(ip6_addr_t * ip6addr, struct netif * netif);
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static s8_t nd6_get_router(ip6_addr_t * router_addr, struct netif * netif);
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static s8_t nd6_new_router(ip6_addr_t * router_addr, struct netif * netif);
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static s8_t nd6_get_onlink_prefix(ip6_addr_t * prefix, struct netif * netif);
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static s8_t nd6_new_onlink_prefix(ip6_addr_t * prefix, struct netif * netif);
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#define ND6_SEND_FLAG_MULTICAST_DEST 0x01
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#define ND6_SEND_FLAG_ALLNODES_DEST 0x02
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static void nd6_send_ns(struct netif * netif, ip6_addr_t * target_addr, u8_t flags);
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static void nd6_send_na(struct netif * netif, ip6_addr_t * target_addr, u8_t flags);
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#if LWIP_IPV6_SEND_ROUTER_SOLICIT
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static void nd6_send_rs(struct netif * netif);
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#endif /* LWIP_IPV6_SEND_ROUTER_SOLICIT */
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#if LWIP_ND6_QUEUEING
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static void nd6_free_q(struct nd6_q_entry *q);
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#else /* LWIP_ND6_QUEUEING */
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#define nd6_free_q(q) pbuf_free(q)
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#endif /* LWIP_ND6_QUEUEING */
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static void nd6_send_q(s8_t i);
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/**
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* Process an incoming neighbor discovery message
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*
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* @param p the nd packet, p->payload pointing to the icmpv6 header
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* @param inp the netif on which this packet was received
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*/
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void
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nd6_input(struct pbuf *p, struct netif *inp)
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{
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u8_t msg_type;
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s8_t i;
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ND6_STATS_INC(nd6.recv);
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msg_type = *((u8_t *)p->payload);
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switch (msg_type) {
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case ICMP6_TYPE_NA: /* Neighbor Advertisement. */
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{
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struct na_header * na_hdr;
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struct lladdr_option * lladdr_opt;
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/* Check that na header fits in packet. */
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if (p->len < (sizeof(struct na_header))) {
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/* TODO debug message */
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pbuf_free(p);
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ND6_STATS_INC(nd6.lenerr);
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ND6_STATS_INC(nd6.drop);
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return;
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}
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na_hdr = (struct na_header *)p->payload;
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/* Unsolicited NA?*/
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if (ip6_addr_ismulticast(ip6_current_dest_addr())) {
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/* This is an unsolicited NA.
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* link-layer changed?
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* part of DAD mechanism? */
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/* Check that link-layer address option also fits in packet. */
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if (p->len < (sizeof(struct na_header) + sizeof(struct lladdr_option))) {
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/* TODO debug message */
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pbuf_free(p);
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ND6_STATS_INC(nd6.lenerr);
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ND6_STATS_INC(nd6.drop);
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return;
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}
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lladdr_opt = (struct lladdr_option *)((u8_t*)p->payload + sizeof(struct na_header));
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/* Override ip6_current_dest_addr() so that we have an aligned copy. */
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ip6_addr_set(ip6_current_dest_addr(), &(na_hdr->target_address));
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#if LWIP_IPV6_DUP_DETECT_ATTEMPTS
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/* If the target address matches this netif, it is a DAD response. */
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for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
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if (ip6_addr_cmp(ip6_current_dest_addr(), netif_ip6_addr(inp, i))) {
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/* We are using a duplicate address. */
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netif_ip6_addr_set_state(inp, i, IP6_ADDR_INVALID);
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#if LWIP_IPV6_MLD
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/* Leave solicited node multicast group. */
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ip6_addr_set_solicitednode(&multicast_address, netif_ip6_addr(inp, i)->addr[3]);
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mld6_leavegroup(netif_ip6_addr(inp, i), &multicast_address);
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#endif /* LWIP_IPV6_MLD */
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#if LWIP_IPV6_AUTOCONFIG
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/* Check to see if this address was autoconfigured. */
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if (!ip6_addr_islinklocal(ip6_current_dest_addr())) {
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i = nd6_get_onlink_prefix(ip6_current_dest_addr(), inp);
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if (i >= 0) {
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/* Mark this prefix as duplicate, so that we don't use it
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* to generate this address again. */
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prefix_list[i].flags |= ND6_PREFIX_AUTOCONFIG_ADDRESS_DUPLICATE;
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}
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}
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#endif /* LWIP_IPV6_AUTOCONFIG */
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pbuf_free(p);
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return;
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}
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}
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#endif /* LWIP_IPV6_DUP_DETECT_ATTEMPTS */
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/* This is an unsolicited NA, most likely there was a LLADDR change. */
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i = nd6_find_neighbor_cache_entry(ip6_current_dest_addr());
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if (i >= 0) {
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if (na_hdr->flags & ND6_FLAG_OVERRIDE) {
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MEMCPY(neighbor_cache[i].lladdr, lladdr_opt->addr, inp->hwaddr_len);
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}
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}
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}
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else {
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/* This is a solicited NA.
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* neighbor address resolution response?
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* neighbor unreachability detection response? */
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/* Override ip6_current_dest_addr() so that we have an aligned copy. */
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ip6_addr_set(ip6_current_dest_addr(), &(na_hdr->target_address));
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/* Find the cache entry corresponding to this na. */
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i = nd6_find_neighbor_cache_entry(ip6_current_dest_addr());
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if (i < 0) {
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/* We no longer care about this target address. drop it. */
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pbuf_free(p);
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return;
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}
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/* Update cache entry. */
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neighbor_cache[i].netif = inp;
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neighbor_cache[i].counter.reachable_time = reachable_time;
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if ((na_hdr->flags & ND6_FLAG_OVERRIDE) ||
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(neighbor_cache[i].state == ND6_INCOMPLETE)) {
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/* Check that link-layer address option also fits in packet. */
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if (p->len < (sizeof(struct na_header) + sizeof(struct lladdr_option))) {
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/* TODO debug message */
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pbuf_free(p);
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ND6_STATS_INC(nd6.lenerr);
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ND6_STATS_INC(nd6.drop);
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return;
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}
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lladdr_opt = (struct lladdr_option *)((u8_t*)p->payload + sizeof(struct na_header));
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MEMCPY(neighbor_cache[i].lladdr, lladdr_opt->addr, inp->hwaddr_len);
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}
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neighbor_cache[i].state = ND6_REACHABLE;
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/* Send queued packets, if any. */
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if (neighbor_cache[i].q != NULL) {
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nd6_send_q(i);
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}
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}
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break; /* ICMP6_TYPE_NA */
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}
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case ICMP6_TYPE_NS: /* Neighbor solicitation. */
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{
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struct ns_header * ns_hdr;
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struct lladdr_option * lladdr_opt;
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u8_t accepted;
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/* Check that ns header fits in packet. */
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if (p->len < sizeof(struct ns_header)) {
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/* TODO debug message */
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pbuf_free(p);
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ND6_STATS_INC(nd6.lenerr);
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ND6_STATS_INC(nd6.drop);
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return;
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}
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ns_hdr = (struct ns_header *)p->payload;
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/* Check if there is a link-layer address provided. Only point to it if in this buffer. */
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lladdr_opt = NULL;
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if (p->len >= (sizeof(struct ns_header) + sizeof(struct lladdr_option))) {
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lladdr_opt = (struct lladdr_option *)((u8_t*)p->payload + sizeof(struct ns_header));
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}
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/* Check if the target address is configured on the receiving netif. */
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accepted = 0;
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for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; ++i) {
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if ((ip6_addr_isvalid(netif_ip6_addr_state(inp, i)) ||
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(ip6_addr_istentative(netif_ip6_addr_state(inp, i)) &&
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ip6_addr_isany(ip6_current_src_addr()))) &&
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ip6_addr_cmp(&(ns_hdr->target_address), netif_ip6_addr(inp, i))) {
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accepted = 1;
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break;
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}
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}
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/* NS not for us? */
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if (!accepted) {
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pbuf_free(p);
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return;
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}
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/* Check for ANY address in src (DAD algorithm). */
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if (ip6_addr_isany(ip6_current_src_addr())) {
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/* Sender is validating this address. */
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for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; ++i) {
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if (ip6_addr_cmp(&(ns_hdr->target_address), netif_ip6_addr(inp, i))) {
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/* Send a NA back so that the sender does not use this address. */
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nd6_send_na(inp, netif_ip6_addr(inp, i), ND6_FLAG_OVERRIDE | ND6_SEND_FLAG_ALLNODES_DEST);
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if (ip6_addr_istentative(netif_ip6_addr_state(inp, i))) {
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/* We shouldn't use this address either. */
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netif_ip6_addr_set_state(inp, i, IP6_ADDR_INVALID);
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}
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}
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}
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}
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else {
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/* Sender is trying to resolve our address. */
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/* Verify that they included their own link-layer address. */
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if (lladdr_opt == NULL) {
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/* Not a valid message. */
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pbuf_free(p);
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ND6_STATS_INC(nd6.proterr);
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ND6_STATS_INC(nd6.drop);
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return;
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}
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i = nd6_find_neighbor_cache_entry(ip6_current_src_addr());
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if ( i>= 0) {
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/* We already have a record for the solicitor. */
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if (neighbor_cache[i].state == ND6_INCOMPLETE) {
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neighbor_cache[i].netif = inp;
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MEMCPY(neighbor_cache[i].lladdr, lladdr_opt->addr, inp->hwaddr_len);
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/* Delay probe in case we get confirmation of reachability from upper layer (TCP). */
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neighbor_cache[i].state = ND6_DELAY;
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neighbor_cache[i].counter.delay_time = LWIP_ND6_DELAY_FIRST_PROBE_TIME;
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}
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}
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else
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{
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/* Add their IPv6 address and link-layer address to neighbor cache.
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* We will need it at least to send a unicast NA message, but most
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* likely we will also be communicating with this node soon. */
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i = nd6_new_neighbor_cache_entry();
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if (i < 0) {
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/* We couldn't assign a cache entry for this neighbor.
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* we won't be able to reply. drop it. */
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pbuf_free(p);
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ND6_STATS_INC(nd6.memerr);
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return;
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}
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neighbor_cache[i].netif = inp;
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MEMCPY(neighbor_cache[i].lladdr, lladdr_opt->addr, inp->hwaddr_len);
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ip6_addr_set(&(neighbor_cache[i].next_hop_address), ip6_current_src_addr());
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/* Receiving a message does not prove reachability: only in one direction.
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* Delay probe in case we get confirmation of reachability from upper layer (TCP). */
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neighbor_cache[i].state = ND6_DELAY;
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neighbor_cache[i].counter.delay_time = LWIP_ND6_DELAY_FIRST_PROBE_TIME;
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}
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/* Override ip6_current_dest_addr() so that we have an aligned copy. */
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ip6_addr_set(ip6_current_dest_addr(), &(ns_hdr->target_address));
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/* Send back a NA for us. Allocate the reply pbuf. */
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nd6_send_na(inp, ip6_current_dest_addr(), ND6_FLAG_SOLICITED | ND6_FLAG_OVERRIDE);
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}
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break; /* ICMP6_TYPE_NS */
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}
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case ICMP6_TYPE_RA: /* Router Advertisement. */
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{
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struct ra_header * ra_hdr;
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u8_t * buffer; /* Used to copy options. */
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u16_t offset;
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/* Check that RA header fits in packet. */
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if (p->len < sizeof(struct ra_header)) {
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/* TODO debug message */
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pbuf_free(p);
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ND6_STATS_INC(nd6.lenerr);
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ND6_STATS_INC(nd6.drop);
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return;
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}
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ra_hdr = (struct ra_header *)p->payload;
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/* If we are sending RS messages, stop. */
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#if LWIP_IPV6_SEND_ROUTER_SOLICIT
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inp->rs_count = 0;
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#endif /* LWIP_IPV6_SEND_ROUTER_SOLICIT */
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/* Get the matching default router entry. */
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i = nd6_get_router(ip6_current_src_addr(), inp);
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if (i < 0) {
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/* Create a new router entry. */
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i = nd6_new_router(ip6_current_src_addr(), inp);
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}
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if (i < 0) {
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/* Could not create a new router entry. */
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pbuf_free(p);
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ND6_STATS_INC(nd6.memerr);
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return;
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}
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/* Re-set invalidation timer. */
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default_router_list[i].invalidation_timer = ra_hdr->router_lifetime;
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/* Re-set default timer values. */
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#if LWIP_ND6_ALLOW_RA_UPDATES
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if (ra_hdr->retrans_timer > 0) {
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retrans_timer = ra_hdr->retrans_timer;
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}
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if (ra_hdr->reachable_time > 0) {
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reachable_time = ra_hdr->reachable_time;
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}
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#endif /* LWIP_ND6_ALLOW_RA_UPDATES */
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/* TODO set default hop limit... */
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/* ra_hdr->current_hop_limit;*/
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/* Update flags in local entry (incl. preference). */
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default_router_list[i].flags = ra_hdr->flags;
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/* Offset to options. */
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offset = sizeof(struct ra_header);
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/* Process each option. */
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while ((p->tot_len - offset) > 0) {
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if (p->len == p->tot_len) {
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/* no need to copy from contiguous pbuf */
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buffer = &((u8_t*)p->payload)[offset];
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} else {
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buffer = nd6_ra_buffer;
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pbuf_copy_partial(p, buffer, sizeof(struct prefix_option), offset);
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}
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switch (buffer[0]) {
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case ND6_OPTION_TYPE_SOURCE_LLADDR:
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{
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struct lladdr_option * lladdr_opt;
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lladdr_opt = (struct lladdr_option *)buffer;
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if ((default_router_list[i].neighbor_entry != NULL) &&
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(default_router_list[i].neighbor_entry->state == ND6_INCOMPLETE)) {
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SMEMCPY(default_router_list[i].neighbor_entry->lladdr, lladdr_opt->addr, inp->hwaddr_len);
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default_router_list[i].neighbor_entry->state = ND6_REACHABLE;
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default_router_list[i].neighbor_entry->counter.reachable_time = reachable_time;
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}
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|
break;
|
|
}
|
|
case ND6_OPTION_TYPE_MTU:
|
|
{
|
|
struct mtu_option * mtu_opt;
|
|
mtu_opt = (struct mtu_option *)buffer;
|
|
if (mtu_opt->mtu >= 1280) {
|
|
#if LWIP_ND6_ALLOW_RA_UPDATES
|
|
inp->mtu = mtu_opt->mtu;
|
|
#endif /* LWIP_ND6_ALLOW_RA_UPDATES */
|
|
}
|
|
break;
|
|
}
|
|
case ND6_OPTION_TYPE_PREFIX_INFO:
|
|
{
|
|
struct prefix_option * prefix_opt;
|
|
prefix_opt = (struct prefix_option *)buffer;
|
|
|
|
if (prefix_opt->flags & ND6_PREFIX_FLAG_ON_LINK) {
|
|
/* Add to on-link prefix list. */
|
|
|
|
/* Get a memory-aligned copy of the prefix. */
|
|
ip6_addr_set(ip6_current_dest_addr(), &(prefix_opt->prefix));
|
|
|
|
/* find cache entry for this prefix. */
|
|
i = nd6_get_onlink_prefix(ip6_current_dest_addr(), inp);
|
|
if (i < 0) {
|
|
/* Create a new cache entry. */
|
|
i = nd6_new_onlink_prefix(ip6_current_dest_addr(), inp);
|
|
}
|
|
if (i >= 0) {
|
|
prefix_list[i].invalidation_timer = prefix_opt->valid_lifetime;
|
|
|
|
#if LWIP_IPV6_AUTOCONFIG
|
|
if (prefix_opt->flags & ND6_PREFIX_FLAG_AUTONOMOUS) {
|
|
/* Mark prefix as autonomous, so that address autoconfiguration can take place.
|
|
* Only OR flag, so that we don't over-write other flags (such as ADDRESS_DUPLICATE)*/
|
|
prefix_list[i].flags |= ND6_PREFIX_AUTOCONFIG_AUTONOMOUS;
|
|
}
|
|
#endif /* LWIP_IPV6_AUTOCONFIG */
|
|
}
|
|
}
|
|
|
|
break;
|
|
}
|
|
case ND6_OPTION_TYPE_ROUTE_INFO:
|
|
{
|
|
/* TODO implement preferred routes.
|
|
struct route_option * route_opt;
|
|
route_opt = (struct route_option *)buffer;*/
|
|
|
|
break;
|
|
}
|
|
default:
|
|
/* Unrecognized option, abort. */
|
|
ND6_STATS_INC(nd6.proterr);
|
|
break;
|
|
}
|
|
offset += 8 * ((u16_t)buffer[1]);
|
|
}
|
|
|
|
break; /* ICMP6_TYPE_RA */
|
|
}
|
|
case ICMP6_TYPE_RD: /* Redirect */
|
|
{
|
|
struct redirect_header * redir_hdr;
|
|
struct lladdr_option * lladdr_opt;
|
|
|
|
/* Check that Redir header fits in packet. */
|
|
if (p->len < sizeof(struct redirect_header)) {
|
|
/* TODO debug message */
|
|
pbuf_free(p);
|
|
ND6_STATS_INC(nd6.lenerr);
|
|
ND6_STATS_INC(nd6.drop);
|
|
return;
|
|
}
|
|
|
|
redir_hdr = (struct redirect_header *)p->payload;
|
|
|
|
lladdr_opt = NULL;
|
|
if (p->len >= (sizeof(struct redirect_header) + sizeof(struct lladdr_option))) {
|
|
lladdr_opt = (struct lladdr_option *)((u8_t*)p->payload + sizeof(struct redirect_header));
|
|
}
|
|
|
|
/* Copy original destination address to current source address, to have an aligned copy. */
|
|
ip6_addr_set(ip6_current_src_addr(), &(redir_hdr->destination_address));
|
|
|
|
/* Find dest address in cache */
|
|
i = nd6_find_destination_cache_entry(ip6_current_src_addr());
|
|
if (i < 0) {
|
|
/* Destination not in cache, drop packet. */
|
|
pbuf_free(p);
|
|
return;
|
|
}
|
|
|
|
/* Set the new target address. */
|
|
ip6_addr_set(&(destination_cache[i].next_hop_addr), &(redir_hdr->target_address));
|
|
|
|
/* If Link-layer address of other router is given, try to add to neighbor cache. */
|
|
if (lladdr_opt != NULL) {
|
|
if (lladdr_opt->type == ND6_OPTION_TYPE_TARGET_LLADDR) {
|
|
/* Copy target address to current source address, to have an aligned copy. */
|
|
ip6_addr_set(ip6_current_src_addr(), &(redir_hdr->target_address));
|
|
|
|
i = nd6_find_neighbor_cache_entry(ip6_current_src_addr());
|
|
if (i < 0) {
|
|
i = nd6_new_neighbor_cache_entry();
|
|
if (i >= 0) {
|
|
neighbor_cache[i].netif = inp;
|
|
MEMCPY(neighbor_cache[i].lladdr, lladdr_opt->addr, inp->hwaddr_len);
|
|
ip6_addr_set(&(neighbor_cache[i].next_hop_address), ip6_current_src_addr());
|
|
|
|
/* Receiving a message does not prove reachability: only in one direction.
|
|
* Delay probe in case we get confirmation of reachability from upper layer (TCP). */
|
|
neighbor_cache[i].state = ND6_DELAY;
|
|
neighbor_cache[i].counter.delay_time = LWIP_ND6_DELAY_FIRST_PROBE_TIME;
|
|
}
|
|
}
|
|
if (i >= 0) {
|
|
if (neighbor_cache[i].state == ND6_INCOMPLETE) {
|
|
MEMCPY(neighbor_cache[i].lladdr, lladdr_opt->addr, inp->hwaddr_len);
|
|
/* Receiving a message does not prove reachability: only in one direction.
|
|
* Delay probe in case we get confirmation of reachability from upper layer (TCP). */
|
|
neighbor_cache[i].state = ND6_DELAY;
|
|
neighbor_cache[i].counter.delay_time = LWIP_ND6_DELAY_FIRST_PROBE_TIME;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
break; /* ICMP6_TYPE_RD */
|
|
}
|
|
case ICMP6_TYPE_PTB: /* Packet too big */
|
|
{
|
|
struct icmp6_hdr *icmp6hdr; /* Packet too big message */
|
|
struct ip6_hdr * ip6hdr; /* IPv6 header of the packet which caused the error */
|
|
|
|
/* Check that ICMPv6 header + IPv6 header fit in payload */
|
|
if (p->len < (sizeof(struct icmp6_hdr) + IP6_HLEN)) {
|
|
/* drop short packets */
|
|
pbuf_free(p);
|
|
ND6_STATS_INC(nd6.lenerr);
|
|
ND6_STATS_INC(nd6.drop);
|
|
return;
|
|
}
|
|
|
|
icmp6hdr = (struct icmp6_hdr *)p->payload;
|
|
ip6hdr = (struct ip6_hdr *)((u8_t*)p->payload + sizeof(struct icmp6_hdr));
|
|
|
|
/* Copy original destination address to current source address, to have an aligned copy. */
|
|
ip6_addr_set(ip6_current_src_addr(), &(ip6hdr->dest));
|
|
|
|
/* Look for entry in destination cache. */
|
|
i = nd6_find_destination_cache_entry(ip6_current_src_addr());
|
|
if (i < 0) {
|
|
/* Destination not in cache, drop packet. */
|
|
pbuf_free(p);
|
|
return;
|
|
}
|
|
|
|
/* Change the Path MTU. */
|
|
destination_cache[i].pmtu = icmp6hdr->data;
|
|
|
|
break; /* ICMP6_TYPE_PTB */
|
|
}
|
|
|
|
default:
|
|
ND6_STATS_INC(nd6.proterr);
|
|
ND6_STATS_INC(nd6.drop);
|
|
break; /* default */
|
|
}
|
|
|
|
pbuf_free(p);
|
|
}
|
|
|
|
|
|
/**
|
|
* Periodic timer for Neighbor discovery functions:
|
|
*
|
|
* - Update neighbor reachability states
|
|
* - Update destination cache entries age
|
|
* - Update invalidation timers of default routers and on-link prefixes
|
|
* - Perform duplicate address detection (DAD) for our addresses
|
|
* - Send router solicitations
|
|
*/
|
|
void
|
|
nd6_tmr(void)
|
|
{
|
|
s8_t i, j;
|
|
struct netif * netif;
|
|
|
|
/* Process neighbor entries. */
|
|
for (i = 0; i < LWIP_ND6_NUM_NEIGHBORS; i++) {
|
|
switch (neighbor_cache[i].state) {
|
|
case ND6_INCOMPLETE:
|
|
if (neighbor_cache[i].counter.probes_sent >= LWIP_ND6_MAX_MULTICAST_SOLICIT) {
|
|
/* Retries exceeded. */
|
|
nd6_free_neighbor_cache_entry(i);
|
|
}
|
|
else {
|
|
/* Send a NS for this entry. */
|
|
neighbor_cache[i].counter.probes_sent++;
|
|
nd6_send_ns(neighbor_cache[i].netif, &(neighbor_cache[i].next_hop_address), ND6_SEND_FLAG_MULTICAST_DEST);
|
|
}
|
|
break;
|
|
case ND6_REACHABLE:
|
|
/* Send queued packets, if any are left. Should have been sent already. */
|
|
if (neighbor_cache[i].q != NULL) {
|
|
nd6_send_q(i);
|
|
}
|
|
if (neighbor_cache[i].counter.reachable_time <= ND6_TMR_INTERVAL) {
|
|
/* Change to stale state. */
|
|
neighbor_cache[i].state = ND6_STALE;
|
|
neighbor_cache[i].counter.stale_time = 0;
|
|
}
|
|
else {
|
|
neighbor_cache[i].counter.reachable_time -= ND6_TMR_INTERVAL;
|
|
}
|
|
break;
|
|
case ND6_STALE:
|
|
neighbor_cache[i].counter.stale_time += ND6_TMR_INTERVAL;
|
|
break;
|
|
case ND6_DELAY:
|
|
if (neighbor_cache[i].counter.delay_time <= ND6_TMR_INTERVAL) {
|
|
/* Change to PROBE state. */
|
|
neighbor_cache[i].state = ND6_PROBE;
|
|
neighbor_cache[i].counter.probes_sent = 0;
|
|
}
|
|
else {
|
|
neighbor_cache[i].counter.delay_time -= ND6_TMR_INTERVAL;
|
|
}
|
|
break;
|
|
case ND6_PROBE:
|
|
if (neighbor_cache[i].counter.probes_sent >= LWIP_ND6_MAX_MULTICAST_SOLICIT) {
|
|
/* Retries exceeded. */
|
|
nd6_free_neighbor_cache_entry(i);
|
|
}
|
|
else {
|
|
/* Send a NS for this entry. */
|
|
neighbor_cache[i].counter.probes_sent++;
|
|
nd6_send_ns(neighbor_cache[i].netif, &(neighbor_cache[i].next_hop_address), 0);
|
|
}
|
|
break;
|
|
case ND6_NO_ENTRY:
|
|
default:
|
|
/* Do nothing. */
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Process destination entries. */
|
|
for (i = 0; i < LWIP_ND6_NUM_DESTINATIONS; i++) {
|
|
destination_cache[i].age++;
|
|
}
|
|
|
|
/* Process router entries. */
|
|
for (i = 0; i < LWIP_ND6_NUM_ROUTERS; i++) {
|
|
if (default_router_list[i].neighbor_entry != NULL) {
|
|
/* Active entry. */
|
|
if (default_router_list[i].invalidation_timer > 0) {
|
|
default_router_list[i].invalidation_timer -= ND6_TMR_INTERVAL / 1000;
|
|
}
|
|
if (default_router_list[i].invalidation_timer < ND6_TMR_INTERVAL / 1000) {
|
|
/* Less than 1 second remainig. Clear this entry. */
|
|
default_router_list[i].neighbor_entry->isrouter = 0;
|
|
default_router_list[i].neighbor_entry = NULL;
|
|
default_router_list[i].invalidation_timer = 0;
|
|
default_router_list[i].flags = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Process prefix entries. */
|
|
for (i = 0; i < LWIP_ND6_NUM_PREFIXES; i++) {
|
|
if (prefix_list[i].invalidation_timer < ND6_TMR_INTERVAL / 1000) {
|
|
prefix_list[i].invalidation_timer = 0;
|
|
}
|
|
if ((prefix_list[i].invalidation_timer > 0) &&
|
|
(prefix_list[i].netif != NULL)) {
|
|
prefix_list[i].invalidation_timer -= ND6_TMR_INTERVAL / 1000;
|
|
|
|
#if LWIP_IPV6_AUTOCONFIG
|
|
/* Initiate address autoconfiguration for this prefix, if conditions are met. */
|
|
if (prefix_list[i].netif->ip6_autoconfig_enabled &&
|
|
(prefix_list[i].flags & ND6_PREFIX_AUTOCONFIG_AUTONOMOUS) &&
|
|
!(prefix_list[i].flags & ND6_PREFIX_AUTOCONFIG_ADDRESS_GENERATED)) {
|
|
/* Try to get an address on this netif that is invalid.
|
|
* Skip 0 index (link-local address) */
|
|
for (j = 1; j < LWIP_IPV6_NUM_ADDRESSES; j++) {
|
|
if (netif_ip6_addr_state(prefix_list[i].netif, j) == IP6_ADDRESS_STATE_INVALID) {
|
|
/* Generate an address using this prefix and interface ID from link-local address. */
|
|
prefix_list[i].netif->ip6_addr[j].addr[0] = prefix_list[i].prefix.addr[0];
|
|
prefix_list[i].netif->ip6_addr[j].addr[1] = prefix_list[i].prefix.addr[1];
|
|
prefix_list[i].netif->ip6_addr[j].addr[2] = prefix_list[i].netif->ip6_addr[0].addr[2];
|
|
prefix_list[i].netif->ip6_addr[j].addr[3] = prefix_list[i].netif->ip6_addr[0].addr[3];
|
|
|
|
/* Mark it as tentative (DAD will be performed if configured). */
|
|
netif_ip6_addr_set_state(prefix_list[i].netif, j, IP6_ADDR_TENTATIVE);
|
|
|
|
/* Mark this prefix with ADDRESS_GENERATED, so that we don't try again. */
|
|
prefix_list[i].flags |= ND6_PREFIX_AUTOCONFIG_ADDRESS_GENERATED;
|
|
|
|
/* Exit loop. */
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
#endif /* LWIP_IPV6_AUTOCONFIG */
|
|
}
|
|
}
|
|
|
|
|
|
/* Process our own addresses, if DAD configured. */
|
|
for (netif = netif_list; netif != NULL; netif = netif->next) {
|
|
for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; ++i) {
|
|
if (ip6_addr_istentative(netif->ip6_addr_state[i])) {
|
|
if ((netif->ip6_addr_state[i] & 0x07) >= LWIP_IPV6_DUP_DETECT_ATTEMPTS) {
|
|
/* No NA received in response. Mark address as valid. */
|
|
netif->ip6_addr_state[i] = IP6_ADDR_PREFERRED;
|
|
/* TODO implement preferred and valid lifetimes. */
|
|
}
|
|
else if (netif->flags & NETIF_FLAG_UP) {
|
|
#if LWIP_IPV6_MLD
|
|
if ((netif->ip6_addr_state[i] & 0x07) == 0) {
|
|
/* Join solicited node multicast group. */
|
|
ip6_addr_set_solicitednode(&multicast_address, netif_ip6_addr(netif, i)->addr[3]);
|
|
mld6_joingroup(netif_ip6_addr(netif, i), &multicast_address);
|
|
}
|
|
#endif /* LWIP_IPV6_MLD */
|
|
/* Send a NS for this address. */
|
|
nd6_send_ns(netif, netif_ip6_addr(netif, i), ND6_SEND_FLAG_MULTICAST_DEST);
|
|
(netif->ip6_addr_state[i])++;
|
|
/* TODO send max 1 NS per tmr call? enable return*/
|
|
/*return;*/
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#if LWIP_IPV6_SEND_ROUTER_SOLICIT
|
|
/* Send router solicitation messages, if necessary. */
|
|
for (netif = netif_list; netif != NULL; netif = netif->next) {
|
|
if ((netif->rs_count > 0) && (netif->flags & NETIF_FLAG_UP)) {
|
|
nd6_send_rs(netif);
|
|
netif->rs_count--;
|
|
}
|
|
}
|
|
#endif /* LWIP_IPV6_SEND_ROUTER_SOLICIT */
|
|
|
|
}
|
|
|
|
/**
|
|
* Send a neighbor solicitation message
|
|
*
|
|
* @param netif the netif on which to send the message
|
|
* @param target_addr the IPv6 target address for the ND message
|
|
* @param flags one of ND6_SEND_FLAG_*
|
|
*/
|
|
static void
|
|
nd6_send_ns(struct netif * netif, ip6_addr_t * target_addr, u8_t flags)
|
|
{
|
|
struct ns_header * ns_hdr;
|
|
struct lladdr_option * lladdr_opt;
|
|
struct pbuf * p;
|
|
ip6_addr_t * src_addr;
|
|
|
|
if (ip6_addr_isvalid(netif_ip6_addr_state(netif,0))) {
|
|
/* Use link-local address as source address. */
|
|
src_addr = netif_ip6_addr(netif, 0);
|
|
} else {
|
|
src_addr = IP6_ADDR_ANY;
|
|
}
|
|
|
|
/* Allocate a packet. */
|
|
p = pbuf_alloc(PBUF_IP, sizeof(struct ns_header) + sizeof(struct lladdr_option), PBUF_RAM);
|
|
if ((p == NULL) || (p->len < (sizeof(struct ns_header) + sizeof(struct lladdr_option)))) {
|
|
/* We couldn't allocate a suitable pbuf for the ns. drop it. */
|
|
if (p != NULL) {
|
|
pbuf_free(p);
|
|
}
|
|
ND6_STATS_INC(nd6.memerr);
|
|
return;
|
|
}
|
|
|
|
/* Set fields. */
|
|
ns_hdr = (struct ns_header *)p->payload;
|
|
lladdr_opt = (struct lladdr_option *)((u8_t*)p->payload + sizeof(struct ns_header));
|
|
|
|
ns_hdr->type = ICMP6_TYPE_NS;
|
|
ns_hdr->code = 0;
|
|
ns_hdr->chksum = 0;
|
|
ns_hdr->reserved = 0;
|
|
ip6_addr_set(&(ns_hdr->target_address), target_addr);
|
|
|
|
lladdr_opt->type = ND6_OPTION_TYPE_SOURCE_LLADDR;
|
|
lladdr_opt->length = ((netif->hwaddr_len + 2) >> 3) + (((netif->hwaddr_len + 2) & 0x07) ? 1 : 0);
|
|
SMEMCPY(lladdr_opt->addr, netif->hwaddr, netif->hwaddr_len);
|
|
|
|
/* Generate the solicited node address for the target address. */
|
|
if (flags & ND6_SEND_FLAG_MULTICAST_DEST) {
|
|
ip6_addr_set_solicitednode(&multicast_address, target_addr->addr[3]);
|
|
target_addr = &multicast_address;
|
|
}
|
|
|
|
ns_hdr->chksum = ip6_chksum_pseudo(p, IP6_NEXTH_ICMP6, p->len, src_addr,
|
|
target_addr);
|
|
|
|
/* Send the packet out. */
|
|
ND6_STATS_INC(nd6.xmit);
|
|
ip6_output_if(p, (src_addr == IP6_ADDR_ANY) ? NULL : src_addr, target_addr,
|
|
LWIP_ICMP6_HL, 0, IP6_NEXTH_ICMP6, netif);
|
|
pbuf_free(p);
|
|
}
|
|
|
|
/**
|
|
* Send a neighbor advertisement message
|
|
*
|
|
* @param netif the netif on which to send the message
|
|
* @param target_addr the IPv6 target address for the ND message
|
|
* @param flags one of ND6_SEND_FLAG_*
|
|
*/
|
|
static void
|
|
nd6_send_na(struct netif * netif, ip6_addr_t * target_addr, u8_t flags)
|
|
{
|
|
struct na_header * na_hdr;
|
|
struct lladdr_option * lladdr_opt;
|
|
struct pbuf * p;
|
|
ip6_addr_t * src_addr;
|
|
ip6_addr_t * dest_addr;
|
|
|
|
/* Use link-local address as source address. */
|
|
/* src_addr = &(netif->ip6_addr[0]); */
|
|
/* Use target address as source address. */
|
|
src_addr = target_addr;
|
|
|
|
/* Allocate a packet. */
|
|
p = pbuf_alloc(PBUF_IP, sizeof(struct na_header) + sizeof(struct lladdr_option), PBUF_RAM);
|
|
if ((p == NULL) || (p->len < (sizeof(struct na_header) + sizeof(struct lladdr_option)))) {
|
|
/* We couldn't allocate a suitable pbuf for the ns. drop it. */
|
|
if (p != NULL) {
|
|
pbuf_free(p);
|
|
}
|
|
ND6_STATS_INC(nd6.memerr);
|
|
return;
|
|
}
|
|
|
|
/* Set fields. */
|
|
na_hdr = (struct na_header *)p->payload;
|
|
lladdr_opt = (struct lladdr_option *)((u8_t*)p->payload + sizeof(struct na_header));
|
|
|
|
na_hdr->type = ICMP6_TYPE_NA;
|
|
na_hdr->code = 0;
|
|
na_hdr->chksum = 0;
|
|
na_hdr->flags = flags & 0xf0;
|
|
na_hdr->reserved[0] = 0;
|
|
na_hdr->reserved[1] = 0;
|
|
na_hdr->reserved[2] = 0;
|
|
ip6_addr_set(&(na_hdr->target_address), target_addr);
|
|
|
|
lladdr_opt->type = ND6_OPTION_TYPE_TARGET_LLADDR;
|
|
lladdr_opt->length = ((netif->hwaddr_len + 2) >> 3) + (((netif->hwaddr_len + 2) & 0x07) ? 1 : 0);
|
|
SMEMCPY(lladdr_opt->addr, netif->hwaddr, netif->hwaddr_len);
|
|
|
|
/* Generate the solicited node address for the target address. */
|
|
if (flags & ND6_SEND_FLAG_MULTICAST_DEST) {
|
|
ip6_addr_set_solicitednode(&multicast_address, target_addr->addr[3]);
|
|
dest_addr = &multicast_address;
|
|
}
|
|
else if (flags & ND6_SEND_FLAG_ALLNODES_DEST) {
|
|
ip6_addr_set_allnodes_linklocal(&multicast_address);
|
|
dest_addr = &multicast_address;
|
|
}
|
|
else {
|
|
dest_addr = ip6_current_src_addr();
|
|
}
|
|
|
|
na_hdr->chksum = ip6_chksum_pseudo(p, IP6_NEXTH_ICMP6, p->len, src_addr,
|
|
dest_addr);
|
|
|
|
/* Send the packet out. */
|
|
ND6_STATS_INC(nd6.xmit);
|
|
ip6_output_if(p, src_addr, dest_addr,
|
|
LWIP_ICMP6_HL, 0, IP6_NEXTH_ICMP6, netif);
|
|
pbuf_free(p);
|
|
}
|
|
|
|
#if LWIP_IPV6_SEND_ROUTER_SOLICIT
|
|
/**
|
|
* Send a router solicitation message
|
|
*
|
|
* @param netif the netif on which to send the message
|
|
*/
|
|
static void
|
|
nd6_send_rs(struct netif * netif)
|
|
{
|
|
struct rs_header * rs_hdr;
|
|
struct lladdr_option * lladdr_opt;
|
|
struct pbuf * p;
|
|
ip6_addr_t * src_addr;
|
|
u16_t packet_len;
|
|
|
|
/* Link-local source address, or unspecified address? */
|
|
if (ip6_addr_isvalid(netif_ip6_addr_state(netif, 0))) {
|
|
src_addr = netif_ip6_addr(netif, 0);
|
|
}
|
|
else {
|
|
src_addr = IP6_ADDR_ANY;
|
|
}
|
|
|
|
/* Generate the all routers target address. */
|
|
ip6_addr_set_allrouters_linklocal(&multicast_address);
|
|
|
|
/* Allocate a packet. */
|
|
packet_len = sizeof(struct rs_header);
|
|
if (src_addr != IP6_ADDR_ANY) {
|
|
packet_len += sizeof(struct lladdr_option);
|
|
}
|
|
p = pbuf_alloc(PBUF_IP, packet_len, PBUF_RAM);
|
|
if ((p == NULL) || (p->len < packet_len)) {
|
|
/* We couldn't allocate a suitable pbuf for the ns. drop it. */
|
|
if (p != NULL) {
|
|
pbuf_free(p);
|
|
}
|
|
ND6_STATS_INC(nd6.memerr);
|
|
return;
|
|
}
|
|
|
|
/* Set fields. */
|
|
rs_hdr = (struct rs_header *)p->payload;
|
|
|
|
rs_hdr->type = ICMP6_TYPE_RS;
|
|
rs_hdr->code = 0;
|
|
rs_hdr->chksum = 0;
|
|
rs_hdr->reserved = 0;
|
|
|
|
if (src_addr != IP6_ADDR_ANY) {
|
|
/* Include our hw address. */
|
|
lladdr_opt = (struct lladdr_option *)((u8_t*)p->payload + sizeof(struct rs_header));
|
|
lladdr_opt->type = ND6_OPTION_TYPE_SOURCE_LLADDR;
|
|
lladdr_opt->length = ((netif->hwaddr_len + 2) >> 3) + (((netif->hwaddr_len + 2) & 0x07) ? 1 : 0);
|
|
SMEMCPY(lladdr_opt->addr, netif->hwaddr, netif->hwaddr_len);
|
|
}
|
|
|
|
rs_hdr->chksum = ip6_chksum_pseudo(p, IP6_NEXTH_ICMP6, p->len, src_addr,
|
|
&multicast_address);
|
|
|
|
/* Send the packet out. */
|
|
ND6_STATS_INC(nd6.xmit);
|
|
ip6_output_if(p, src_addr, &multicast_address,
|
|
LWIP_ICMP6_HL, 0, IP6_NEXTH_ICMP6, netif);
|
|
pbuf_free(p);
|
|
}
|
|
#endif /* LWIP_IPV6_SEND_ROUTER_SOLICIT */
|
|
|
|
/**
|
|
* Search for a neighbor cache entry
|
|
*
|
|
* @param ip6addr the IPv6 address of the neighbor
|
|
* @return The neighbor cache entry index that matched, -1 if no
|
|
* entry is found
|
|
*/
|
|
static s8_t
|
|
nd6_find_neighbor_cache_entry(ip6_addr_t * ip6addr)
|
|
{
|
|
s8_t i;
|
|
for (i = 0; i < LWIP_ND6_NUM_NEIGHBORS; i++) {
|
|
if (ip6_addr_cmp(ip6addr, &(neighbor_cache[i].next_hop_address))) {
|
|
return i;
|
|
}
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Create a new neighbor cache entry.
|
|
*
|
|
* If no unused entry is found, will try to recycle an old entry
|
|
* according to ad-hoc "age" heuristic.
|
|
*
|
|
* @return The neighbor cache entry index that was created, -1 if no
|
|
* entry could be created
|
|
*/
|
|
static s8_t
|
|
nd6_new_neighbor_cache_entry(void)
|
|
{
|
|
s8_t i;
|
|
s8_t j;
|
|
u32_t time;
|
|
|
|
|
|
/* First, try to find an empty entry. */
|
|
for (i = 0; i < LWIP_ND6_NUM_NEIGHBORS; i++) {
|
|
if (neighbor_cache[i].state == ND6_NO_ENTRY) {
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* We need to recycle an entry. in general, do not recycle if it is a router. */
|
|
|
|
/* Next, try to find a Stale entry. */
|
|
for (i = 0; i < LWIP_ND6_NUM_NEIGHBORS; i++) {
|
|
if ((neighbor_cache[i].state == ND6_STALE) &&
|
|
(!neighbor_cache[i].isrouter)) {
|
|
nd6_free_neighbor_cache_entry(i);
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* Next, try to find a Probe entry. */
|
|
for (i = 0; i < LWIP_ND6_NUM_NEIGHBORS; i++) {
|
|
if ((neighbor_cache[i].state == ND6_PROBE) &&
|
|
(!neighbor_cache[i].isrouter)) {
|
|
nd6_free_neighbor_cache_entry(i);
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* Next, try to find a Delayed entry. */
|
|
for (i = 0; i < LWIP_ND6_NUM_NEIGHBORS; i++) {
|
|
if ((neighbor_cache[i].state == ND6_DELAY) &&
|
|
(!neighbor_cache[i].isrouter)) {
|
|
nd6_free_neighbor_cache_entry(i);
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* Next, try to find the oldest reachable entry. */
|
|
time = 0xfffffffful;
|
|
j = -1;
|
|
for (i = 0; i < LWIP_ND6_NUM_NEIGHBORS; i++) {
|
|
if ((neighbor_cache[i].state == ND6_REACHABLE) &&
|
|
(!neighbor_cache[i].isrouter)) {
|
|
if (neighbor_cache[i].counter.reachable_time < time) {
|
|
j = i;
|
|
time = neighbor_cache[i].counter.reachable_time;
|
|
}
|
|
}
|
|
}
|
|
if (j >= 0) {
|
|
nd6_free_neighbor_cache_entry(j);
|
|
return j;
|
|
}
|
|
|
|
/* Next, find oldest incomplete entry without queued packets. */
|
|
time = 0;
|
|
j = -1;
|
|
for (i = 0; i < LWIP_ND6_NUM_NEIGHBORS; i++) {
|
|
if (
|
|
(neighbor_cache[i].q == NULL) &&
|
|
(neighbor_cache[i].state == ND6_INCOMPLETE) &&
|
|
(!neighbor_cache[i].isrouter)) {
|
|
if (neighbor_cache[i].counter.probes_sent >= time) {
|
|
j = i;
|
|
time = neighbor_cache[i].counter.probes_sent;
|
|
}
|
|
}
|
|
}
|
|
if (j >= 0) {
|
|
nd6_free_neighbor_cache_entry(j);
|
|
return j;
|
|
}
|
|
|
|
/* Next, find oldest incomplete entry with queued packets. */
|
|
time = 0;
|
|
j = -1;
|
|
for (i = 0; i < LWIP_ND6_NUM_NEIGHBORS; i++) {
|
|
if ((neighbor_cache[i].state == ND6_INCOMPLETE) &&
|
|
(!neighbor_cache[i].isrouter)) {
|
|
if (neighbor_cache[i].counter.probes_sent >= time) {
|
|
j = i;
|
|
time = neighbor_cache[i].counter.probes_sent;
|
|
}
|
|
}
|
|
}
|
|
if (j >= 0) {
|
|
nd6_free_neighbor_cache_entry(j);
|
|
return j;
|
|
}
|
|
|
|
/* No more entries to try. */
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Will free any resources associated with a neighbor cache
|
|
* entry, and will mark it as unused.
|
|
*
|
|
* @param i the neighbor cache entry index to free
|
|
*/
|
|
static void
|
|
nd6_free_neighbor_cache_entry(s8_t i)
|
|
{
|
|
if ((i < 0) || (i >= LWIP_ND6_NUM_NEIGHBORS)) {
|
|
return;
|
|
}
|
|
|
|
/* Free any queued packets. */
|
|
if (neighbor_cache[i].q != NULL) {
|
|
nd6_free_q(neighbor_cache[i].q);
|
|
neighbor_cache[i].q = NULL;
|
|
}
|
|
|
|
neighbor_cache[i].state = ND6_NO_ENTRY;
|
|
neighbor_cache[i].isrouter = 0;
|
|
neighbor_cache[i].netif = NULL;
|
|
neighbor_cache[i].counter.reachable_time = 0;
|
|
ip6_addr_set_zero(&(neighbor_cache[i].next_hop_address));
|
|
}
|
|
|
|
/**
|
|
* Search for a destination cache entry
|
|
*
|
|
* @param ip6addr the IPv6 address of the destination
|
|
* @return The destination cache entry index that matched, -1 if no
|
|
* entry is found
|
|
*/
|
|
static s8_t
|
|
nd6_find_destination_cache_entry(ip6_addr_t * ip6addr)
|
|
{
|
|
s8_t i;
|
|
for (i = 0; i < LWIP_ND6_NUM_DESTINATIONS; i++) {
|
|
if (ip6_addr_cmp(ip6addr, &(destination_cache[i].destination_addr))) {
|
|
return i;
|
|
}
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Create a new destination cache entry. If no unused entry is found,
|
|
* will recycle oldest entry.
|
|
*
|
|
* @return The destination cache entry index that was created, -1 if no
|
|
* entry was created
|
|
*/
|
|
static s8_t
|
|
nd6_new_destination_cache_entry(void)
|
|
{
|
|
s8_t i, j;
|
|
u32_t age;
|
|
|
|
/* Find an empty entry. */
|
|
for (i = 0; i < LWIP_ND6_NUM_DESTINATIONS; i++) {
|
|
if (ip6_addr_isany(&(destination_cache[i].destination_addr))) {
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* Find oldest entry. */
|
|
age = 0;
|
|
j = LWIP_ND6_NUM_DESTINATIONS - 1;
|
|
for (i = 0; i < LWIP_ND6_NUM_DESTINATIONS; i++) {
|
|
if (destination_cache[i].age > age) {
|
|
j = i;
|
|
}
|
|
}
|
|
|
|
return j;
|
|
}
|
|
|
|
/**
|
|
* Determine whether an address matches an on-link prefix.
|
|
*
|
|
* @param ip6addr the IPv6 address to match
|
|
* @return 1 if the address is on-link, 0 otherwise
|
|
*/
|
|
static s8_t
|
|
nd6_is_prefix_in_netif(ip6_addr_t * ip6addr, struct netif * netif)
|
|
{
|
|
s8_t i;
|
|
for (i = 0; i < LWIP_ND6_NUM_PREFIXES; i++) {
|
|
if ((prefix_list[i].netif == netif) &&
|
|
(prefix_list[i].invalidation_timer > 0) &&
|
|
ip6_addr_netcmp(ip6addr, &(prefix_list[i].prefix))) {
|
|
return 1;
|
|
}
|
|
}
|
|
/* Check to see if address prefix matches a (manually?) configured address. */
|
|
for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
|
|
if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
|
|
ip6_addr_netcmp(ip6addr, netif_ip6_addr(netif, i))) {
|
|
return 1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Select a default router for a destination.
|
|
*
|
|
* @param ip6addr the destination address
|
|
* @param netif the netif for the outgoing packet, if known
|
|
* @return the default router entry index, or -1 if no suitable
|
|
* router is found
|
|
*/
|
|
s8_t
|
|
nd6_select_router(ip6_addr_t * ip6addr, struct netif * netif)
|
|
{
|
|
s8_t i;
|
|
/* last_router is used for round-robin router selection (as recommended
|
|
* in RFC). This is more robust in case one router is not reachable,
|
|
* we are not stuck trying to resolve it. */
|
|
static s8_t last_router;
|
|
(void)ip6addr; /* TODO match preferred routes!! (must implement ND6_OPTION_TYPE_ROUTE_INFO) */
|
|
|
|
/* TODO: implement default router preference */
|
|
|
|
/* Look for reachable routers. */
|
|
for (i = 0; i < LWIP_ND6_NUM_ROUTERS; i++) {
|
|
if (++last_router >= LWIP_ND6_NUM_ROUTERS) {
|
|
last_router = 0;
|
|
}
|
|
if ((default_router_list[i].neighbor_entry != NULL) &&
|
|
(netif != NULL ? netif == default_router_list[i].neighbor_entry->netif : 1) &&
|
|
(default_router_list[i].invalidation_timer > 0) &&
|
|
(default_router_list[i].neighbor_entry->state == ND6_REACHABLE)) {
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* Look for router in other reachability states, but still valid according to timer. */
|
|
for (i = 0; i < LWIP_ND6_NUM_ROUTERS; i++) {
|
|
if (++last_router >= LWIP_ND6_NUM_ROUTERS) {
|
|
last_router = 0;
|
|
}
|
|
if ((default_router_list[i].neighbor_entry != NULL) &&
|
|
(netif != NULL ? netif == default_router_list[i].neighbor_entry->netif : 1) &&
|
|
(default_router_list[i].invalidation_timer > 0)) {
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* Look for any router for which we have any information at all. */
|
|
for (i = 0; i < LWIP_ND6_NUM_ROUTERS; i++) {
|
|
if (++last_router >= LWIP_ND6_NUM_ROUTERS) {
|
|
last_router = 0;
|
|
}
|
|
if (default_router_list[i].neighbor_entry != NULL &&
|
|
(netif != NULL ? netif == default_router_list[i].neighbor_entry->netif : 1)) {
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* no suitable router found. */
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Find an entry for a default router.
|
|
*
|
|
* @param router_addr the IPv6 address of the router
|
|
* @param netif the netif on which the router is found, if known
|
|
* @return the index of the router entry, or -1 if not found
|
|
*/
|
|
static s8_t
|
|
nd6_get_router(ip6_addr_t * router_addr, struct netif * netif)
|
|
{
|
|
s8_t i;
|
|
|
|
/* Look for router. */
|
|
for (i = 0; i < LWIP_ND6_NUM_ROUTERS; i++) {
|
|
if ((default_router_list[i].neighbor_entry != NULL) &&
|
|
((netif != NULL) ? netif == default_router_list[i].neighbor_entry->netif : 1) &&
|
|
ip6_addr_cmp(router_addr, &(default_router_list[i].neighbor_entry->next_hop_address))) {
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* router not found. */
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Create a new entry for a default router.
|
|
*
|
|
* @param router_addr the IPv6 address of the router
|
|
* @param netif the netif on which the router is connected, if known
|
|
* @return the index on the router table, or -1 if could not be created
|
|
*/
|
|
static s8_t
|
|
nd6_new_router(ip6_addr_t * router_addr, struct netif * netif)
|
|
{
|
|
s8_t router_index;
|
|
s8_t neighbor_index;
|
|
|
|
/* Do we have a neighbor entry for this router? */
|
|
neighbor_index = nd6_find_neighbor_cache_entry(router_addr);
|
|
if (neighbor_index < 0) {
|
|
/* Create a neighbor entry for this router. */
|
|
neighbor_index = nd6_new_neighbor_cache_entry();
|
|
if (neighbor_index < 0) {
|
|
/* Could not create neighbor entry for this router. */
|
|
return -1;
|
|
}
|
|
ip6_addr_set(&(neighbor_cache[neighbor_index].next_hop_address), router_addr);
|
|
neighbor_cache[neighbor_index].netif = netif;
|
|
neighbor_cache[neighbor_index].q = NULL;
|
|
neighbor_cache[neighbor_index].state = ND6_INCOMPLETE;
|
|
neighbor_cache[neighbor_index].counter.probes_sent = 0;
|
|
}
|
|
|
|
/* Mark neighbor as router. */
|
|
neighbor_cache[neighbor_index].isrouter = 1;
|
|
|
|
/* Look for empty entry. */
|
|
for (router_index = 0; router_index < LWIP_ND6_NUM_ROUTERS; router_index++) {
|
|
if (default_router_list[router_index].neighbor_entry == NULL) {
|
|
default_router_list[router_index].neighbor_entry = &(neighbor_cache[neighbor_index]);
|
|
return router_index;
|
|
}
|
|
}
|
|
|
|
/* Could not create a router entry. */
|
|
|
|
/* Mark neighbor entry as not-router. Entry might be useful as neighbor still. */
|
|
neighbor_cache[neighbor_index].isrouter = 0;
|
|
|
|
/* router not found. */
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Find the cached entry for an on-link prefix.
|
|
*
|
|
* @param prefix the IPv6 prefix that is on-link
|
|
* @param netif the netif on which the prefix is on-link
|
|
* @return the index on the prefix table, or -1 if not found
|
|
*/
|
|
static s8_t
|
|
nd6_get_onlink_prefix(ip6_addr_t * prefix, struct netif * netif)
|
|
{
|
|
s8_t i;
|
|
|
|
/* Look for prefix in list. */
|
|
for (i = 0; i < LWIP_ND6_NUM_PREFIXES; ++i) {
|
|
if ((ip6_addr_netcmp(&(prefix_list[i].prefix), prefix)) &&
|
|
(prefix_list[i].netif == netif)) {
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* Entry not available. */
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Creates a new entry for an on-link prefix.
|
|
*
|
|
* @param prefix the IPv6 prefix that is on-link
|
|
* @param netif the netif on which the prefix is on-link
|
|
* @return the index on the prefix table, or -1 if not created
|
|
*/
|
|
static s8_t
|
|
nd6_new_onlink_prefix(ip6_addr_t * prefix, struct netif * netif)
|
|
{
|
|
s8_t i;
|
|
|
|
/* Create new entry. */
|
|
for (i = 0; i < LWIP_ND6_NUM_PREFIXES; ++i) {
|
|
if ((prefix_list[i].netif == NULL) ||
|
|
(prefix_list[i].invalidation_timer == 0)) {
|
|
/* Found empty prefix entry. */
|
|
prefix_list[i].netif = netif;
|
|
ip6_addr_set(&(prefix_list[i].prefix), prefix);
|
|
prefix_list[i].flags = 0;
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* Entry not available. */
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Determine the next hop for a destination. Will determine if the
|
|
* destination is on-link, else a suitable on-link router is selected.
|
|
*
|
|
* The last entry index is cached for fast entry search.
|
|
*
|
|
* @param ip6addr the destination address
|
|
* @param netif the netif on which the packet will be sent
|
|
* @return the neighbor cache entry for the next hop, ERR_RTE if no
|
|
* suitable next hop was found, ERR_MEM if no cache entry
|
|
* could be created
|
|
*/
|
|
s8_t
|
|
nd6_get_next_hop_entry(ip6_addr_t * ip6addr, struct netif * netif)
|
|
{
|
|
s8_t i;
|
|
|
|
#if LWIP_NETIF_HWADDRHINT
|
|
if (netif->addr_hint != NULL) {
|
|
/* per-pcb cached entry was given */
|
|
u8_t addr_hint = *(netif->addr_hint);
|
|
if (addr_hint < LWIP_ND6_NUM_DESTINATIONS) {
|
|
nd6_cached_destination_index = addr_hint;
|
|
}
|
|
}
|
|
#endif /* LWIP_NETIF_HWADDRHINT */
|
|
|
|
/* Look for ip6addr in destination cache. */
|
|
if (ip6_addr_cmp(ip6addr, &(destination_cache[nd6_cached_destination_index].destination_addr))) {
|
|
/* the cached entry index is the right one! */
|
|
/* do nothing. */
|
|
ND6_STATS_INC(nd6.cachehit);
|
|
} else {
|
|
/* Search destination cache. */
|
|
i = nd6_find_destination_cache_entry(ip6addr);
|
|
if (i >= 0) {
|
|
/* found destination entry. make it our new cached index. */
|
|
nd6_cached_destination_index = i;
|
|
}
|
|
else {
|
|
/* Not found. Create a new destination entry. */
|
|
i = nd6_new_destination_cache_entry();
|
|
if (i >= 0) {
|
|
/* got new destination entry. make it our new cached index. */
|
|
nd6_cached_destination_index = i;
|
|
} else {
|
|
/* Could not create a destination cache entry. */
|
|
return ERR_MEM;
|
|
}
|
|
|
|
/* Copy dest address to destination cache. */
|
|
ip6_addr_set(&(destination_cache[nd6_cached_destination_index].destination_addr), ip6addr);
|
|
|
|
/* Now find the next hop. is it a neighbor? */
|
|
if (ip6_addr_islinklocal(ip6addr) ||
|
|
nd6_is_prefix_in_netif(ip6addr, netif)) {
|
|
/* Destination in local link. */
|
|
destination_cache[nd6_cached_destination_index].pmtu = netif->mtu;
|
|
ip6_addr_copy(destination_cache[nd6_cached_destination_index].next_hop_addr, destination_cache[nd6_cached_destination_index].destination_addr);
|
|
}
|
|
else {
|
|
/* We need to select a router. */
|
|
i = nd6_select_router(ip6addr, netif);
|
|
if (i < 0) {
|
|
/* No router found. */
|
|
ip6_addr_set_any(&(destination_cache[nd6_cached_destination_index].destination_addr));
|
|
return ERR_RTE;
|
|
}
|
|
destination_cache[nd6_cached_destination_index].pmtu = netif->mtu; /* Start with netif mtu, correct through ICMPv6 if necessary */
|
|
ip6_addr_copy(destination_cache[nd6_cached_destination_index].next_hop_addr, default_router_list[i].neighbor_entry->next_hop_address);
|
|
}
|
|
}
|
|
}
|
|
|
|
#if LWIP_NETIF_HWADDRHINT
|
|
if (netif->addr_hint != NULL) {
|
|
/* per-pcb cached entry was given */
|
|
*(netif->addr_hint) = nd6_cached_destination_index;
|
|
}
|
|
#endif /* LWIP_NETIF_HWADDRHINT */
|
|
|
|
/* Look in neighbor cache for the next-hop address. */
|
|
if (ip6_addr_cmp(&(destination_cache[nd6_cached_destination_index].next_hop_addr),
|
|
&(neighbor_cache[nd6_cached_neighbor_index].next_hop_address))) {
|
|
/* Cache hit. */
|
|
/* Do nothing. */
|
|
ND6_STATS_INC(nd6.cachehit);
|
|
} else {
|
|
i = nd6_find_neighbor_cache_entry(&(destination_cache[nd6_cached_destination_index].next_hop_addr));
|
|
if (i >= 0) {
|
|
/* Found a matching record, make it new cached entry. */
|
|
nd6_cached_neighbor_index = i;
|
|
}
|
|
else {
|
|
/* Neighbor not in cache. Make a new entry. */
|
|
i = nd6_new_neighbor_cache_entry();
|
|
if (i >= 0) {
|
|
/* got new neighbor entry. make it our new cached index. */
|
|
nd6_cached_neighbor_index = i;
|
|
} else {
|
|
/* Could not create a neighbor cache entry. */
|
|
return ERR_MEM;
|
|
}
|
|
|
|
/* Initialize fields. */
|
|
ip6_addr_copy(neighbor_cache[i].next_hop_address,
|
|
destination_cache[nd6_cached_destination_index].next_hop_addr);
|
|
neighbor_cache[i].isrouter = 0;
|
|
neighbor_cache[i].netif = netif;
|
|
neighbor_cache[i].state = ND6_INCOMPLETE;
|
|
neighbor_cache[i].counter.probes_sent = 0;
|
|
}
|
|
}
|
|
|
|
/* Reset this destination's age. */
|
|
destination_cache[nd6_cached_destination_index].age = 0;
|
|
|
|
return nd6_cached_neighbor_index;
|
|
}
|
|
|
|
/**
|
|
* Queue a packet for a neighbor.
|
|
*
|
|
* @param neighbor_index the index in the neighbor cache table
|
|
* @param q packet to be queued
|
|
* @return ERR_OK if succeeded, ERR_MEM if out of memory
|
|
*/
|
|
err_t
|
|
nd6_queue_packet(s8_t neighbor_index, struct pbuf * q)
|
|
{
|
|
err_t result = ERR_MEM;
|
|
struct pbuf *p;
|
|
int copy_needed = 0;
|
|
#if LWIP_ND6_QUEUEING
|
|
struct nd6_q_entry *new_entry, *r;
|
|
#endif /* LWIP_ND6_QUEUEING */
|
|
|
|
if ((neighbor_index < 0) || (neighbor_index >= LWIP_ND6_NUM_NEIGHBORS)) {
|
|
return ERR_ARG;
|
|
}
|
|
|
|
/* IF q includes a PBUF_REF, PBUF_POOL or PBUF_RAM, we have no choice but
|
|
* to copy the whole queue into a new PBUF_RAM (see bug #11400)
|
|
* PBUF_ROMs can be left as they are, since ROM must not get changed. */
|
|
p = q;
|
|
while (p) {
|
|
if(p->type != PBUF_ROM) {
|
|
copy_needed = 1;
|
|
break;
|
|
}
|
|
p = p->next;
|
|
}
|
|
if(copy_needed) {
|
|
/* copy the whole packet into new pbufs */
|
|
p = pbuf_alloc(PBUF_LINK, q->tot_len, PBUF_RAM);
|
|
while ((p == NULL) && (neighbor_cache[neighbor_index].q != NULL)) {
|
|
/* Free oldest packet (as per RFC recommendation) */
|
|
#if LWIP_ND6_QUEUEING
|
|
r = neighbor_cache[neighbor_index].q;
|
|
neighbor_cache[neighbor_index].q = r->next;
|
|
r->next = NULL;
|
|
nd6_free_q(r);
|
|
#else /* LWIP_ND6_QUEUEING */
|
|
pbuf_free(neighbor_cache[neighbor_index].q);
|
|
neighbor_cache[neighbor_index].q = NULL;
|
|
#endif /* LWIP_ND6_QUEUEING */
|
|
p = pbuf_alloc(PBUF_LINK, q->tot_len, PBUF_RAM);
|
|
}
|
|
if(p != NULL) {
|
|
if (pbuf_copy(p, q) != ERR_OK) {
|
|
pbuf_free(p);
|
|
p = NULL;
|
|
}
|
|
}
|
|
} else {
|
|
/* referencing the old pbuf is enough */
|
|
p = q;
|
|
pbuf_ref(p);
|
|
}
|
|
/* packet was copied/ref'd? */
|
|
if (p != NULL) {
|
|
/* queue packet ... */
|
|
#if LWIP_ND6_QUEUEING
|
|
/* allocate a new nd6 queue entry */
|
|
new_entry = (struct nd6_q_entry *)memp_malloc(MEMP_ND6_QUEUE);
|
|
if ((new_entry == NULL) && (neighbor_cache[neighbor_index].q != NULL)) {
|
|
/* Free oldest packet (as per RFC recommendation) */
|
|
r = neighbor_cache[neighbor_index].q;
|
|
neighbor_cache[neighbor_index].q = r->next;
|
|
r->next = NULL;
|
|
nd6_free_q(r);
|
|
new_entry = (struct nd6_q_entry *)memp_malloc(MEMP_ND6_QUEUE);
|
|
}
|
|
if (new_entry != NULL) {
|
|
new_entry->next = NULL;
|
|
new_entry->p = p;
|
|
if(neighbor_cache[neighbor_index].q != NULL) {
|
|
/* queue was already existent, append the new entry to the end */
|
|
r = neighbor_cache[neighbor_index].q;
|
|
while (r->next != NULL) {
|
|
r = r->next;
|
|
}
|
|
r->next = new_entry;
|
|
} else {
|
|
/* queue did not exist, first item in queue */
|
|
neighbor_cache[neighbor_index].q = new_entry;
|
|
}
|
|
LWIP_DEBUGF(LWIP_DBG_TRACE, ("ipv6: queued packet %p on neighbor entry %"S16_F"\n", (void *)p, (s16_t)neighbor_index));
|
|
result = ERR_OK;
|
|
} else {
|
|
/* the pool MEMP_ND6_QUEUE is empty */
|
|
pbuf_free(p);
|
|
LWIP_DEBUGF(LWIP_DBG_TRACE, ("ipv6: could not queue a copy of packet %p (out of memory)\n", (void *)p));
|
|
/* { result == ERR_MEM } through initialization */
|
|
}
|
|
#else /* LWIP_ND6_QUEUEING */
|
|
/* Queue a single packet. If an older packet is already queued, free it as per RFC. */
|
|
if (neighbor_cache[neighbor_index].q != NULL) {
|
|
pbuf_free(neighbor_cache[neighbor_index].q);
|
|
}
|
|
neighbor_cache[neighbor_index].q = p;
|
|
LWIP_DEBUGF(LWIP_DBG_TRACE, ("ipv6: queued packet %p on neighbor entry %"S16_F"\n", (void *)p, (s16_t)neighbor_index));
|
|
result = ERR_OK;
|
|
#endif /* LWIP_ND6_QUEUEING */
|
|
} else {
|
|
LWIP_DEBUGF(LWIP_DBG_TRACE, ("ipv6: could not queue a copy of packet %p (out of memory)\n", (void *)q));
|
|
/* { result == ERR_MEM } through initialization */
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
#if LWIP_ND6_QUEUEING
|
|
/**
|
|
* Free a complete queue of nd6 q entries
|
|
*
|
|
* @param q a queue of nd6_q_entry to free
|
|
*/
|
|
static void
|
|
nd6_free_q(struct nd6_q_entry *q)
|
|
{
|
|
struct nd6_q_entry *r;
|
|
LWIP_ASSERT("q != NULL", q != NULL);
|
|
LWIP_ASSERT("q->p != NULL", q->p != NULL);
|
|
while (q) {
|
|
r = q;
|
|
q = q->next;
|
|
LWIP_ASSERT("r->p != NULL", (r->p != NULL));
|
|
pbuf_free(r->p);
|
|
memp_free(MEMP_ND6_QUEUE, r);
|
|
}
|
|
}
|
|
#endif /* LWIP_ND6_QUEUEING */
|
|
|
|
/**
|
|
* Send queued packets for a neighbor
|
|
*
|
|
* @param i the neighbor to send packets to
|
|
*/
|
|
static void
|
|
nd6_send_q(s8_t i)
|
|
{
|
|
struct ip6_hdr *ip6hdr;
|
|
#if LWIP_ND6_QUEUEING
|
|
struct nd6_q_entry *q;
|
|
#endif /* LWIP_ND6_QUEUEING */
|
|
|
|
if ((i < 0) || (i >= LWIP_ND6_NUM_NEIGHBORS)) {
|
|
return;
|
|
}
|
|
|
|
#if LWIP_ND6_QUEUEING
|
|
while (neighbor_cache[i].q != NULL) {
|
|
/* remember first in queue */
|
|
q = neighbor_cache[i].q;
|
|
/* pop first item off the queue */
|
|
neighbor_cache[i].q = q->next;
|
|
/* Get ipv6 header. */
|
|
ip6hdr = (struct ip6_hdr *)(q->p->payload);
|
|
/* Override ip6_current_dest_addr() so that we have an aligned copy. */
|
|
ip6_addr_set(ip6_current_dest_addr(), &(ip6hdr->dest));
|
|
/* send the queued IPv6 packet */
|
|
(neighbor_cache[i].netif)->output_ip6(neighbor_cache[i].netif, q->p, ip6_current_dest_addr());
|
|
/* free the queued IP packet */
|
|
pbuf_free(q->p);
|
|
/* now queue entry can be freed */
|
|
memp_free(MEMP_ND6_QUEUE, q);
|
|
}
|
|
#else /* LWIP_ND6_QUEUEING */
|
|
if (neighbor_cache[i].q != NULL) {
|
|
/* Get ipv6 header. */
|
|
ip6hdr = (struct ip6_hdr *)(neighbor_cache[i].q->payload);
|
|
/* Override ip6_current_dest_addr() so that we have an aligned copy. */
|
|
ip6_addr_set(ip6_current_dest_addr(), &(ip6hdr->dest));
|
|
/* send the queued IPv6 packet */
|
|
(neighbor_cache[i].netif)->output_ip6(neighbor_cache[i].netif, neighbor_cache[i].q, ip6_current_dest_addr());
|
|
/* free the queued IP packet */
|
|
pbuf_free(neighbor_cache[i].q);
|
|
neighbor_cache[i].q = NULL;
|
|
}
|
|
#endif /* LWIP_ND6_QUEUEING */
|
|
}
|
|
|
|
|
|
/**
|
|
* Get the Path MTU for a destination.
|
|
*
|
|
* @param ip6addr the destination address
|
|
* @param netif the netif on which the packet will be sent
|
|
* @return the Path MTU, if known, or the netif default MTU
|
|
*/
|
|
u16_t
|
|
nd6_get_destination_mtu(ip6_addr_t * ip6addr, struct netif * netif)
|
|
{
|
|
s8_t i;
|
|
|
|
i = nd6_find_destination_cache_entry(ip6addr);
|
|
if (i >= 0) {
|
|
if (destination_cache[i].pmtu > 0) {
|
|
return destination_cache[i].pmtu;
|
|
}
|
|
}
|
|
|
|
if (netif != NULL) {
|
|
return netif->mtu;
|
|
}
|
|
|
|
return 1280; /* Minimum MTU */
|
|
}
|
|
|
|
|
|
#if LWIP_ND6_TCP_REACHABILITY_HINTS
|
|
/**
|
|
* Provide the Neighbor discovery process with a hint that a
|
|
* destination is reachable. Called by tcp_receive when ACKs are
|
|
* received or sent (as per RFC). This is useful to avoid sending
|
|
* NS messages every 30 seconds.
|
|
*
|
|
* @param ip6addr the destination address which is know to be reachable
|
|
* by an upper layer protocol (TCP)
|
|
*/
|
|
void
|
|
nd6_reachability_hint(ip6_addr_t * ip6addr)
|
|
{
|
|
s8_t i;
|
|
|
|
/* Find destination in cache. */
|
|
if (ip6_addr_cmp(ip6addr, &(destination_cache[nd6_cached_destination_index].destination_addr))) {
|
|
i = nd6_cached_destination_index;
|
|
ND6_STATS_INC(nd6.cachehit);
|
|
}
|
|
else {
|
|
i = nd6_find_destination_cache_entry(ip6addr);
|
|
}
|
|
if (i < 0) {
|
|
return;
|
|
}
|
|
|
|
/* Find next hop neighbor in cache. */
|
|
if (ip6_addr_cmp(&(destination_cache[i].next_hop_addr), &(neighbor_cache[nd6_cached_neighbor_index].next_hop_address))) {
|
|
i = nd6_cached_neighbor_index;
|
|
ND6_STATS_INC(nd6.cachehit);
|
|
}
|
|
else {
|
|
i = nd6_find_neighbor_cache_entry(&(destination_cache[i].next_hop_addr));
|
|
}
|
|
if (i < 0) {
|
|
return;
|
|
}
|
|
|
|
/* Set reachability state. */
|
|
neighbor_cache[i].state = ND6_REACHABLE;
|
|
neighbor_cache[i].counter.reachable_time = reachable_time;
|
|
}
|
|
#endif /* LWIP_ND6_TCP_REACHABILITY_HINTS */
|
|
|
|
#endif /* LWIP_IPV6 */
|