1/**
2 * @file
3 *
4 * Ethernet output for IPv6. Uses ND tables for link-layer addressing.
5 */
6
7/*
8 * Copyright (c) 2010 Inico Technologies Ltd.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without modification,
12 * are permitted provided that the following conditions are met:
13 *
14 * 1. Redistributions of source code must retain the above copyright notice,
15 *    this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright notice,
17 *    this list of conditions and the following disclaimer in the documentation
18 *    and/or other materials provided with the distribution.
19 * 3. The name of the author may not be used to endorse or promote products
20 *    derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
31 * OF SUCH DAMAGE.
32 *
33 * This file is part of the lwIP TCP/IP stack.
34 *
35 * Author: Ivan Delamer <delamer@inicotech.com>
36 *
37 *
38 * Please coordinate changes and requests with Ivan Delamer
39 * <delamer@inicotech.com>
40 */
41
42#include "lwip/opt.h"
43
44#if LWIP_IPV6 && LWIP_ETHERNET
45
46#include "lwip/ethip6.h"
47#include "lwip/nd6.h"
48#include "lwip/pbuf.h"
49#include "lwip/ip6.h"
50#include "lwip/ip6_addr.h"
51#include "lwip/inet_chksum.h"
52#include "lwip/netif.h"
53#include "lwip/icmp6.h"
54#include "lwip/prot/ethernet.h"
55#include "netif/ethernet.h"
56
57#include <string.h>
58
59/**
60 * Resolve and fill-in Ethernet address header for outgoing IPv6 packet.
61 *
62 * For IPv6 multicast, corresponding Ethernet addresses
63 * are selected and the packet is transmitted on the link.
64 *
65 * For unicast addresses, ask the ND6 module what to do. It will either let us
66 * send the the packet right away, or queue the packet for later itself, unless
67 * an error occurs.
68 *
69 * @todo anycast addresses
70 *
71 * @param netif The lwIP network interface which the IP packet will be sent on.
72 * @param q The pbuf(s) containing the IP packet to be sent.
73 * @param ip6addr The IP address of the packet destination.
74 *
75 * @return
76 * - ERR_OK or the return value of @ref nd6_get_next_hop_addr_or_queue.
77 */
78err_t
79ethip6_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr)
80{
81  struct eth_addr dest;
82  const u8_t *hwaddr;
83  err_t result;
84
85  /* multicast destination IP address? */
86  if (ip6_addr_ismulticast(ip6addr)) {
87    /* Hash IP multicast address to MAC address.*/
88    dest.addr[0] = 0x33;
89    dest.addr[1] = 0x33;
90    dest.addr[2] = ((const u8_t *)(&(ip6addr->addr[3])))[0];
91    dest.addr[3] = ((const u8_t *)(&(ip6addr->addr[3])))[1];
92    dest.addr[4] = ((const u8_t *)(&(ip6addr->addr[3])))[2];
93    dest.addr[5] = ((const u8_t *)(&(ip6addr->addr[3])))[3];
94
95    /* Send out. */
96    return ethernet_output(netif, q, (const struct eth_addr*)(netif->hwaddr), &dest, ETHTYPE_IPV6);
97  }
98
99  /* We have a unicast destination IP address */
100  /* @todo anycast? */
101
102  /* Ask ND6 what to do with the packet. */
103  result = nd6_get_next_hop_addr_or_queue(netif, q, ip6addr, &hwaddr);
104  if (result != ERR_OK) {
105    return result;
106  }
107
108  /* If no hardware address is returned, nd6 has queued the packet for later. */
109  if (hwaddr == NULL) {
110    return ERR_OK;
111  }
112
113  /* Send out the packet using the returned hardware address. */
114  SMEMCPY(dest.addr, hwaddr, 6);
115  return ethernet_output(netif, q, (const struct eth_addr*)(netif->hwaddr), &dest, ETHTYPE_IPV6);
116}
117
118#endif /* LWIP_IPV6 && LWIP_ETHERNET */
119