esp-idf/components/lwip/core/ipv6/ethip6.c
2018-05-29 20:07:45 +08:00

160 lines
5.6 KiB
C

/**
* @file
*
* Ethernet output for IPv6. Uses ND tables for link-layer addressing.
*/
/*
* Copyright (c) 2010 Inico Technologies Ltd.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Ivan Delamer <delamer@inicotech.com>
*
*
* Please coordinate changes and requests with Ivan Delamer
* <delamer@inicotech.com>
*/
#include "lwip/opt.h"
#if LWIP_IPV6 && LWIP_ETHERNET
#include "lwip/ethip6.h"
#include "lwip/nd6.h"
#include "lwip/pbuf.h"
#include "lwip/ip6.h"
#include "lwip/ip6_addr.h"
#include "lwip/inet_chksum.h"
#include "lwip/netif.h"
#include "lwip/icmp6.h"
#include "netif/ethernet.h"
#include <string.h>
/**
* Send an IPv6 packet on the network using netif->linkoutput
* The ethernet header is filled in before sending.
*
* @params netif the lwIP network interface on which to send the packet
* @params p the packet to send, p->payload pointing to the (uninitialized) ethernet header
* @params src the source MAC address to be copied into the ethernet header
* @params dst the destination MAC address to be copied into the ethernet header
* @return ERR_OK if the packet was sent, any other err_t on failure
*/
static err_t
ethip6_send(struct netif *netif, struct pbuf *p, struct eth_addr *src, struct eth_addr *dst)
{
struct eth_hdr *ethhdr = (struct eth_hdr *)p->payload;
LWIP_ASSERT("netif->hwaddr_len must be 6 for ethip6!",
(netif->hwaddr_len == 6));
SMEMCPY(&ethhdr->dest, dst, 6);
SMEMCPY(&ethhdr->src, src, 6);
ethhdr->type = PP_HTONS(ETHTYPE_IPV6);
LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("ethip6_send: sending packet %p\n", (void *)p));
/* send the packet */
return netif->linkoutput(netif, p);
}
/**
* Resolve and fill-in Ethernet address header for outgoing IPv6 packet.
*
* For IPv6 multicast, corresponding Ethernet addresses
* are selected and the packet is transmitted on the link.
*
* For unicast addresses, ...
*
* @TODO anycast addresses
*
* @param netif The lwIP network interface which the IP packet will be sent on.
* @param q The pbuf(s) containing the IP packet to be sent.
* @param ip6addr The IP address of the packet destination.
*
* @return
* - ERR_RTE No route to destination (no gateway to external networks),
* or the return type of either etharp_query() or etharp_send_ip().
*/
err_t
ethip6_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr)
{
struct eth_addr dest;
s8_t i;
/* make room for Ethernet header - should not fail */
if (pbuf_header(q, sizeof(struct eth_hdr)) != 0) {
/* bail out */
LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
("etharp_output: could not allocate room for header.\n"));
return ERR_BUF;
}
/* multicast destination IP address? */
if (ip6_addr_ismulticast(ip6addr)) {
/* Hash IP multicast address to MAC address.*/
dest.addr[0] = 0x33;
dest.addr[1] = 0x33;
dest.addr[2] = ((const u8_t *)(&(ip6addr->addr[3])))[0];
dest.addr[3] = ((const u8_t *)(&(ip6addr->addr[3])))[1];
dest.addr[4] = ((const u8_t *)(&(ip6addr->addr[3])))[2];
dest.addr[5] = ((const u8_t *)(&(ip6addr->addr[3])))[3];
/* Send out. */
return ethip6_send(netif, q, (struct eth_addr*)(netif->hwaddr), &dest);
}
/* We have a unicast destination IP address */
/* TODO anycast? */
/* Get next hop record. */
i = nd6_get_next_hop_entry(ip6addr, netif);
if (i < 0) {
/* failed to get a next hop neighbor record. */
return ERR_MEM;
}
/* Now that we have a destination record, send or queue the packet. */
if (neighbor_cache[i].state == ND6_STALE) {
/* Switch to delay state. */
neighbor_cache[i].state = ND6_DELAY;
neighbor_cache[i].counter.delay_time = LWIP_ND6_DELAY_FIRST_PROBE_TIME;
}
/* TODO should we send or queue if PROBE? send for now, to let unicast NS pass. */
if ((neighbor_cache[i].state == ND6_REACHABLE) ||
(neighbor_cache[i].state == ND6_DELAY) ||
(neighbor_cache[i].state == ND6_PROBE)) {
/* Send out. */
SMEMCPY(dest.addr, neighbor_cache[i].lladdr, 6);
return ethip6_send(netif, q, (struct eth_addr*)(netif->hwaddr), &dest);
}
/* We should queue packet on this interface. */
pbuf_header(q, -(s16_t)SIZEOF_ETH_HDR);
return nd6_queue_packet(i, q);
}
#endif /* LWIP_IPV6 && LWIP_ETHERNET */