mcast.c

嵌入式系统设计与实例开发实验教材二源码 多线程应用程序设计 串行端口程序设计 AD接口实验 CAN总线通信实验 GPS通信实验 Linux内核移植与编译实验 IC卡读写实验 SD驱动使

	spin_unlock(&ma->mca_lock);
}

int igmp6_event_query(struct sk_buff *skb)
{
	struct ifmcaddr6 *ma;
	struct in6_addr *addrp;
	unsigned long resptime;
	struct inet6_dev *idev;
	struct icmp6hdr *hdr;

	if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
		return -EINVAL;

	hdr = (struct icmp6hdr*) skb->h.raw;

	/* Drop queries with not link local source */
	if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr)&IPV6_ADDR_LINKLOCAL))
		return -EINVAL;

	resptime = ntohs(hdr->icmp6_maxdelay);
	/* Translate milliseconds to jiffies */
	resptime = (resptime<<10)/(1024000/HZ);

	addrp = (struct in6_addr *) (hdr + 1);

	idev = in6_dev_get(skb->dev);

	if (idev == NULL)
		return 0;

	read_lock(&idev->lock);
	if (ipv6_addr_any(addrp)) {
		for (ma = idev->mc_list; ma; ma=ma->next)
			igmp6_group_queried(ma, resptime);
	} else {
		for (ma = idev->mc_list; ma; ma=ma->next) {
			if (ipv6_addr_cmp(addrp, &ma->mca_addr) == 0) {
				igmp6_group_queried(ma, resptime);
				break;
			}
		}
	}
	read_unlock(&idev->lock);
	in6_dev_put(idev);

	return 0;
}


int igmp6_event_report(struct sk_buff *skb)
{
	struct ifmcaddr6 *ma;
	struct in6_addr *addrp;
	struct inet6_dev *idev;
	struct icmp6hdr *hdr;

	/* Our own report looped back. Ignore it. */
	if (skb->pkt_type == PACKET_LOOPBACK)
		return 0;

	if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
		return -EINVAL;

	hdr = (struct icmp6hdr*) skb->h.raw;

	/* Drop reports with not link local source */
	if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr)&IPV6_ADDR_LINKLOCAL))
		return -EINVAL;

	addrp = (struct in6_addr *) (hdr + 1);

	idev = in6_dev_get(skb->dev);
	if (idev == NULL)
		return -ENODEV;

	/*
	 *	Cancel the timer for this group
	 */

	read_lock(&idev->lock);
	for (ma = idev->mc_list; ma; ma=ma->next) {
		if (ipv6_addr_cmp(&ma->mca_addr, addrp) == 0) {
			spin_lock(&ma->mca_lock);
			if (del_timer(&ma->mca_timer))
				atomic_dec(&ma->mca_refcnt);
			ma->mca_flags &= ~(MAF_LAST_REPORTER|MAF_TIMER_RUNNING);
			spin_unlock(&ma->mca_lock);
			break;
		}
	}
	read_unlock(&idev->lock);
	in6_dev_put(idev);
	return 0;
}

void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
{
	struct sock *sk = igmp6_socket->sk;
        struct sk_buff *skb;
        struct icmp6hdr *hdr;
	struct in6_addr *snd_addr;
	struct in6_addr *addrp;
	struct in6_addr addr_buf;
	struct in6_addr all_routers;
	int err, len, payload_len, full_len;
	u8 ra[8] = { IPPROTO_ICMPV6, 0,
		     IPV6_TLV_ROUTERALERT, 2, 0, 0,
		     IPV6_TLV_PADN, 0 };

	snd_addr = addr;
	if (type == ICMPV6_MGM_REDUCTION) {
		snd_addr = &all_routers;
		ipv6_addr_all_routers(&all_routers);
	}

	len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
	payload_len = len + sizeof(ra);
	full_len = sizeof(struct ipv6hdr) + payload_len;

	skb = sock_alloc_send_skb(sk, dev->hard_header_len + full_len + 15, 0, &err);

	if (skb == NULL)
		return;

	skb_reserve(skb, (dev->hard_header_len + 15) & ~15);
	if (dev->hard_header) {
		unsigned char ha[MAX_ADDR_LEN];
		ndisc_mc_map(snd_addr, ha, dev, 1);
		if (dev->hard_header(skb, dev, ETH_P_IPV6, ha, NULL, full_len) < 0)
			goto out;
	}

	if (ipv6_get_lladdr(dev, &addr_buf)) {
#if MCAST_DEBUG >= 1
		printk(KERN_DEBUG "igmp6: %s no linklocal address\n",
		       dev->name);
#endif
		goto out;
	}

	ip6_nd_hdr(sk, skb, dev, &addr_buf, snd_addr, NEXTHDR_HOP, payload_len);

	memcpy(skb_put(skb, sizeof(ra)), ra, sizeof(ra));

	hdr = (struct icmp6hdr *) skb_put(skb, sizeof(struct icmp6hdr));
	memset(hdr, 0, sizeof(struct icmp6hdr));
	hdr->icmp6_type = type;

	addrp = (struct in6_addr *) skb_put(skb, sizeof(struct in6_addr));
	ipv6_addr_copy(addrp, addr);

	hdr->icmp6_cksum = csum_ipv6_magic(&addr_buf, snd_addr, len,
					   IPPROTO_ICMPV6,
					   csum_partial((__u8 *) hdr, len, 0));

	dev_queue_xmit(skb);
	if (type == ICMPV6_MGM_REDUCTION)
		ICMP6_INC_STATS(Icmp6OutGroupMembReductions);
	else
		ICMP6_INC_STATS(Icmp6OutGroupMembResponses);
	ICMP6_INC_STATS(Icmp6OutMsgs);
	return;

out:
	kfree_skb(skb);
}

static void igmp6_join_group(struct ifmcaddr6 *ma)
{
	unsigned long delay;
	int addr_type;

	addr_type = ipv6_addr_type(&ma->mca_addr);

	if ((addr_type & (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_LOOPBACK)))
		return;

	igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);

	delay = net_random() % IGMP6_UNSOLICITED_IVAL;

	spin_lock_bh(&ma->mca_lock);
	if (del_timer(&ma->mca_timer)) {
		atomic_dec(&ma->mca_refcnt);
		delay = ma->mca_timer.expires - jiffies;
	}

	if (!mod_timer(&ma->mca_timer, jiffies + delay))
		atomic_inc(&ma->mca_refcnt);
	ma->mca_flags |= MAF_TIMER_RUNNING | MAF_LAST_REPORTER;
	spin_unlock_bh(&ma->mca_lock);
}

static void igmp6_leave_group(struct ifmcaddr6 *ma)
{
	int addr_type;

	addr_type = ipv6_addr_type(&ma->mca_addr);

	if ((addr_type & IPV6_ADDR_LINKLOCAL))
		return;

	if (ma->mca_flags & MAF_LAST_REPORTER)
		igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REDUCTION);

	spin_lock_bh(&ma->mca_lock);
	if (del_timer(&ma->mca_timer))
		atomic_dec(&ma->mca_refcnt);
	spin_unlock_bh(&ma->mca_lock);
}

void igmp6_timer_handler(unsigned long data)
{
	struct ifmcaddr6 *ma = (struct ifmcaddr6 *) data;

	igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);

	spin_lock(&ma->mca_lock);
	ma->mca_flags |=  MAF_LAST_REPORTER;
	ma->mca_flags &= ~MAF_TIMER_RUNNING;
	spin_unlock(&ma->mca_lock);
	ma_put(ma);
}

/* Device going down */

void ipv6_mc_down(struct inet6_dev *idev)
{
	struct ifmcaddr6 *i;

	/* Withdraw multicast list */

	read_lock_bh(&idev->lock);
	for (i = idev->mc_list; i; i=i->next)
		igmp6_group_dropped(i);
	read_unlock_bh(&idev->lock);
}


/* Device going up */

void ipv6_mc_up(struct inet6_dev *idev)
{
	struct ifmcaddr6 *i;

	/* Install multicast list, except for all-nodes (already installed) */

	read_lock_bh(&idev->lock);
	for (i = idev->mc_list; i; i=i->next)
		igmp6_group_added(i);
	read_unlock_bh(&idev->lock);
}

/* IPv6 device initialization. */

void ipv6_mc_init_dev(struct inet6_dev *idev)
{
	struct in6_addr maddr;

	/* Add all-nodes address. */
	ipv6_addr_all_nodes(&maddr);
	ipv6_dev_mc_inc(idev->dev, &maddr);
}

/*
 *	Device is about to be destroyed: clean up.
 */

void ipv6_mc_destroy_dev(struct inet6_dev *idev)
{
	struct ifmcaddr6 *i;
	struct in6_addr maddr;

	/* Delete all-nodes address. */
	ipv6_addr_all_nodes(&maddr);
	ipv6_dev_mc_dec(idev->dev, &maddr);

	write_lock_bh(&idev->lock);
	while ((i = idev->mc_list) != NULL) {
		idev->mc_list = i->next;
		write_unlock_bh(&idev->lock);

		igmp6_group_dropped(i);
		ma_put(i);

		write_lock_bh(&idev->lock);
	}
	write_unlock_bh(&idev->lock);
}

#ifdef CONFIG_PROC_FS
static int igmp6_read_proc(char *buffer, char **start, off_t offset,
			   int length, int *eof, void *data)
{
	off_t pos=0, begin=0;
	struct ifmcaddr6 *im;
	int len=0;
	struct net_device *dev;
	
	read_lock(&dev_base_lock);
	for (dev = dev_base; dev; dev = dev->next) {
		struct inet6_dev *idev;

		if ((idev = in6_dev_get(dev)) == NULL)
			continue;

		read_lock_bh(&idev->lock);
		for (im = idev->mc_list; im; im = im->next) {
			int i;

			len += sprintf(buffer+len,"%-4d %-15s ", dev->ifindex, dev->name);

			for (i=0; i<16; i++)
				len += sprintf(buffer+len, "%02x", im->mca_addr.s6_addr[i]);

			len+=sprintf(buffer+len,
				     " %5d %08X %ld\n",
				     im->mca_users,
				     im->mca_flags,
				     (im->mca_flags&MAF_TIMER_RUNNING) ? im->mca_timer.expires-jiffies : 0);

			pos=begin+len;
			if (pos < offset) {
				len=0;
				begin=pos;
			}
			if (pos > offset+length) {
				read_unlock_bh(&idev->lock);
				in6_dev_put(idev);
				goto done;
			}
		}
		read_unlock_bh(&idev->lock);
		in6_dev_put(idev);
	}
	*eof = 1;

done:
	read_unlock(&dev_base_lock);

	*start=buffer+(offset-begin);
	len-=(offset-begin);
	if(len>length)
		len=length;
	if (len<0)
		len=0;
	return len;
}
#endif

int __init igmp6_init(struct net_proto_family *ops)
{
	struct sock *sk;
	int err;

	igmp6_socket = sock_alloc();
	if (igmp6_socket == NULL) {
		printk(KERN_ERR
		       "Failed to create the IGMP6 control socket.\n");
		return -1;
	}
	igmp6_socket->inode->i_uid = 0;
	igmp6_socket->inode->i_gid = 0;
	igmp6_socket->type = SOCK_RAW;

	if((err = ops->create(igmp6_socket, IPPROTO_ICMPV6)) < 0) {
		printk(KERN_DEBUG 
		       "Failed to initialize the IGMP6 control socket (err %d).\n",
		       err);
		sock_release(igmp6_socket);
		igmp6_socket = NULL; /* For safety. */
		return err;
	}

	sk = igmp6_socket->sk;
	sk->allocation = GFP_ATOMIC;
	sk->prot->unhash(sk);

	sk->net_pinfo.af_inet6.hop_limit = 1;
#ifdef CONFIG_PROC_FS
	create_proc_read_entry("net/igmp6", 0, 0, igmp6_read_proc, NULL);
#endif

	return 0;
}

void igmp6_cleanup(void)
{
	sock_release(igmp6_socket);
	igmp6_socket = NULL; /* for safety */
#ifdef CONFIG_PROC_FS
	remove_proc_entry("net/igmp6", 0);
#endif
}