incubator-nuttx/net/igmp/igmp_send.c

173 lines
5.3 KiB
C

/****************************************************************************
* net/igmp/igmp_send.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 <debug.h>
#include <arpa/inet.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/netstats.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/ipopt.h>
#include <nuttx/net/tcp.h>
#include <nuttx/net/igmp.h>
#include "devif/devif.h"
#include "inet/inet.h"
#include "igmp/igmp.h"
#ifdef CONFIG_NET_IGMP
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Debug */
#undef IGMP_DUMPPKT /* Define to enable packet dump */
#ifndef CONFIG_DEBUG_NET
# undef IGMP_DUMPPKT
#endif
#ifdef IGMP_DUMPPKT
# define igmp_dumppkt(b,n) lib_dumpbuffer("IGMP", (FAR const uint8_t*)(b), (n))
#else
# define igmp_dumppkt(b,n)
#endif
/* Buffer layout */
#define RASIZE (4)
/****************************************************************************
* Private Functions
****************************************************************************/
static uint16_t igmp_chksum(FAR uint8_t *buffer, int buflen)
{
uint16_t sum = net_chksum((FAR uint16_t *)buffer, buflen);
return sum ? sum : 0xffff;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: igmp_send
*
* Description:
* Sends an IGMP IP packet on a network interface. This function constructs
* the IP header and calculates the IP header checksum.
*
* Input Parameters:
* dev - The device driver structure to use in the send operation.
* group - Describes the multicast group member and identifies the
* message to be sent.
* destipaddr - The IP address of the recipient of the message
* msgid - ID of message to send
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
void igmp_send(FAR struct net_driver_s *dev, FAR struct igmp_group_s *group,
FAR const in_addr_t *destipaddr, uint8_t msgid)
{
FAR struct igmp_iphdr_s *ipv4 = IPBUF(0);
FAR struct igmp_hdr_s *igmp;
uint16_t iphdrlen;
ninfo("msgid: %02x destipaddr: %08x\n", msgid, (int)*destipaddr);
/* The IGMP header immediately follows the IP header */
iphdrlen = IPv4_HDRLEN + RASIZE;
igmp = IPBUF(iphdrlen);
/* The total length to send is the size of the IP and IGMP headers and 4
* bytes for the ROUTER ALERT (and, eventually, the Ethernet header)
*/
dev->d_len = iphdrlen + IGMP_HDRLEN;
/* The total size of the data is the size of the IGMP header */
dev->d_sndlen = IGMP_HDRLEN;
/* Add the router alert option to the IPv4 header (RFC 2113) */
ipv4->ra[0] = HTONS(IPOPT_RA >> 16);
ipv4->ra[1] = HTONS(IPOPT_RA & 0xffff);
/* Initialize the IPv4 header */
ipv4->vhl = 0x46; /* 4->IP; 6->24 bytes */
ipv4->tos = 0;
ipv4->len[0] = (dev->d_len >> 8);
ipv4->len[1] = (dev->d_len & 0xff);
++g_ipid;
ipv4->ipid[0] = g_ipid >> 8;
ipv4->ipid[1] = g_ipid & 0xff;
ipv4->ipoffset[0] = IP_FLAG_DONTFRAG >> 8;
ipv4->ipoffset[1] = IP_FLAG_DONTFRAG & 0xff;
ipv4->ttl = IGMP_TTL;
ipv4->proto = IP_PROTO_IGMP;
net_ipv4addr_hdrcopy(ipv4->srcipaddr, &dev->d_ipaddr);
net_ipv4addr_hdrcopy(ipv4->destipaddr, destipaddr);
/* Calculate IP checksum. */
ipv4->ipchksum = 0;
ipv4->ipchksum = ~igmp_chksum((FAR uint8_t *)igmp, iphdrlen);
/* Set up the IGMP message */
igmp->type = msgid;
igmp->maxresp = 0;
net_ipv4addr_hdrcopy(igmp->grpaddr, &group->grpaddr);
/* Calculate the IGMP checksum. */
igmp->chksum = 0;
igmp->chksum = ~igmp_chksum(&igmp->type, IGMP_HDRLEN);
IGMP_STATINCR(g_netstats.igmp.poll_send);
IGMP_STATINCR(g_netstats.ipv4.sent);
ninfo("Outgoing IGMP packet length: %d (%d)\n",
dev->d_len, (ipv4->len[0] << 8) | ipv4->len[1]);
igmp_dumppkt(RA, iphdrlen + IGMP_HDRLEN);
}
#endif /* CONFIG_NET_IGMP */