nuttx/net/icmpv6/icmpv6_reply.c

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/****************************************************************************
* net/icmpv6/icmpv6_reply.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <stdint.h>
#include <string.h>
#include <debug.h>
#include <netinet/in.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <nuttx/net/net.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/icmpv6.h>
#include "utils/utils.h"
#include "netdev/netdev.h"
#include "devif/devif.h"
#include "inet/inet.h"
#include "icmpv6/icmpv6.h"
#ifdef CONFIG_NET_ICMPv6
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* The latest drafts declared increase in minimal mtu up to 1280. */
#define ICMPv6_MINMTULEN 1280
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: icmp_reply
*
* Description:
* Send an ICMPv6 message in response to a situation
* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header.
* MAY send more (we do).
* MUST NOT change this header information.
* MUST NOT reply to a multicast/broadcast IP address.
* MUST NOT reply to a multicast/broadcast MAC address.
* MUST reply to only the first fragment.
*
* Input Parameters:
* dev - The device driver structure containing the received packet
* type - ICMPv6 Message Type, eg. ICMPv6_DEST_UNREACHABLE
* code - ICMPv6 Message Code, eg. ICMPv6_PORT_UNREACH
* data - Additional 32-bit parameter in the ICMPv6 header
*
* Returned Value:
* None
*
****************************************************************************/
void icmpv6_reply(FAR struct net_driver_s *dev, int type, int code, int data)
{
int ipicmplen = IPv6_HDRLEN + sizeof(struct icmpv6_hdr_s);
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
FAR struct icmpv6_hdr_s *icmpv6 = (FAR struct icmpv6_hdr_s *)(ipv6 + 1);
uint16_t datalen;
if (net_ipv6addr_cmp(ipv6->destipaddr, g_ipv6_unspecaddr)
# ifdef CONFIG_NET_BROADCAST
|| net_is_addr_mcast(ipv6->destipaddr)
# endif /* CONFIG_NET_BROADCAST */
)
{
dev->d_len = 0;
return;
}
/* Get the data size of the packet. */
datalen = (ipv6->len[0] << 8) + ipv6->len[1];
/* RFC says return as much as we can without exceeding 1280 bytes. */
if (datalen > ICMPv6_MINMTULEN - ipicmplen)
{
datalen = ICMPv6_MINMTULEN - ipicmplen;
}
dev->d_len = ipicmplen + datalen;
/* Copy fields from original packet */
memmove(icmpv6 + 1, ipv6, datalen);
/* Set up the IPv6 header (most is probably already in place) */
ipv6->vtc = 0x60; /* Version/traffic class (MS) */
ipv6->tcf = 0; /* Traffic class(LS)/Flow label(MS) */
ipv6->flow = 0; /* Flow label (LS) */
ipv6->len[0] = (dev->d_len >> 8); /* Length excludes the IPv6 header */
ipv6->len[1] = (dev->d_len & 0xff);
ipv6->proto = IP_PROTO_ICMP6; /* Next header */
ipv6->ttl = 255; /* Hop limit */
net_ipv6addr_hdrcopy(ipv6->destipaddr, ipv6->srcipaddr);
net_ipv6addr_hdrcopy(ipv6->srcipaddr, dev->d_ipv6addr);
/* Initialize the ICMPv6 header */
icmpv6->type = type;
icmpv6->code = code;
icmpv6->data[0] = data >> 16;
icmpv6->data[1] = data & 0xffff;
/* Calculate the ICMPv6 checksum over the ICMPv6 header and payload. */
icmpv6->chksum = 0;
icmpv6->chksum = ~icmpv6_chksum(dev, IPv6_HDRLEN);
if (icmpv6->chksum == 0)
{
icmpv6->chksum = 0xffff;
}
ninfo("Outgoing ICMPv6 packet length: %d (%d)\n",
dev->d_len, (ipv6->len[0] << 8) | ipv6->len[1]);
}
#endif /* CONFIG_NET_ICMPv6 */