mcast.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 2,496 行 · 第 1/4 页

		if (mc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
			rv = 0;
	}
	read_unlock(&ipv6_sk_mc_lock);

	return rv;
}

static void ma_put(struct ifmcaddr6 *mc)
{
	if (atomic_dec_and_test(&mc->mca_refcnt)) {
		in6_dev_put(mc->idev);
		kfree(mc);
	}
}

static void igmp6_group_added(struct ifmcaddr6 *mc)
{
	struct net_device *dev = mc->idev->dev;
	char buf[MAX_ADDR_LEN];

	spin_lock_bh(&mc->mca_lock);
	if (!(mc->mca_flags&MAF_LOADED)) {
		mc->mca_flags |= MAF_LOADED;
		if (ndisc_mc_map(&mc->mca_addr, buf, dev, 0) == 0)
			dev_mc_add(dev, buf, dev->addr_len, 0);
	}
	spin_unlock_bh(&mc->mca_lock);

	if (!(dev->flags & IFF_UP) || (mc->mca_flags & MAF_NOREPORT))
		return;

	if (MLD_V1_SEEN(mc->idev)) {
		igmp6_join_group(mc);
		return;
	}
	/* else v2 */

	mc->mca_crcount = mc->idev->mc_qrv;
	mld_ifc_event(mc->idev);
}

static void igmp6_group_dropped(struct ifmcaddr6 *mc)
{
	struct net_device *dev = mc->idev->dev;
	char buf[MAX_ADDR_LEN];

	spin_lock_bh(&mc->mca_lock);
	if (mc->mca_flags&MAF_LOADED) {
		mc->mca_flags &= ~MAF_LOADED;
		if (ndisc_mc_map(&mc->mca_addr, buf, dev, 0) == 0)
			dev_mc_delete(dev, buf, dev->addr_len, 0);
	}

	if (mc->mca_flags & MAF_NOREPORT)
		goto done;
	spin_unlock_bh(&mc->mca_lock);

	if (!mc->idev->dead)
		igmp6_leave_group(mc);

	spin_lock_bh(&mc->mca_lock);
	if (del_timer(&mc->mca_timer))
		atomic_dec(&mc->mca_refcnt);
done:
	ip6_mc_clear_src(mc);
	spin_unlock_bh(&mc->mca_lock);
}

/*
 * deleted ifmcaddr6 manipulation
 */
static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
{
	struct ifmcaddr6 *pmc;

	/* this is an "ifmcaddr6" for convenience; only the fields below
	 * are actually used. In particular, the refcnt and users are not
	 * used for management of the delete list. Using the same structure
	 * for deleted items allows change reports to use common code with
	 * non-deleted or query-response MCA's.
	 */
	pmc = (struct ifmcaddr6 *)kmalloc(sizeof(*pmc), GFP_ATOMIC);
	if (!pmc)
		return;
	memset(pmc, 0, sizeof(*pmc));
	spin_lock_bh(&im->mca_lock);
	pmc->mca_lock = SPIN_LOCK_UNLOCKED;
	pmc->idev = im->idev;
	in6_dev_hold(idev);
	pmc->mca_addr = im->mca_addr;
	pmc->mca_crcount = idev->mc_qrv;
	pmc->mca_sfmode = im->mca_sfmode;
	if (pmc->mca_sfmode == MCAST_INCLUDE) {
		struct ip6_sf_list *psf;

		pmc->mca_tomb = im->mca_tomb;
		pmc->mca_sources = im->mca_sources;
		im->mca_tomb = im->mca_sources = NULL;
		for (psf=pmc->mca_sources; psf; psf=psf->sf_next)
			psf->sf_crcount = pmc->mca_crcount;
	}
	spin_unlock_bh(&im->mca_lock);

	write_lock_bh(&idev->mc_lock);
	pmc->next = idev->mc_tomb;
	idev->mc_tomb = pmc;
	write_unlock_bh(&idev->mc_lock);
}

static void mld_del_delrec(struct inet6_dev *idev, struct in6_addr *pmca)
{
	struct ifmcaddr6 *pmc, *pmc_prev;
	struct ip6_sf_list *psf, *psf_next;

	write_lock_bh(&idev->mc_lock);
	pmc_prev = NULL;
	for (pmc=idev->mc_tomb; pmc; pmc=pmc->next) {
		if (ipv6_addr_cmp(&pmc->mca_addr, pmca) == 0)
			break;
		pmc_prev = pmc;
	}
	if (pmc) {
		if (pmc_prev)
			pmc_prev->next = pmc->next;
		else
			idev->mc_tomb = pmc->next;
	}
	write_unlock_bh(&idev->mc_lock);
	if (pmc) {
		for (psf=pmc->mca_tomb; psf; psf=psf_next) {
			psf_next = psf->sf_next;
			kfree(psf);
		}
		in6_dev_put(pmc->idev);
		kfree(pmc);
	}
}

static void mld_clear_delrec(struct inet6_dev *idev)
{
	struct ifmcaddr6 *pmc, *nextpmc;

	write_lock_bh(&idev->mc_lock);
	pmc = idev->mc_tomb;
	idev->mc_tomb = NULL;
	write_unlock_bh(&idev->mc_lock);

	for (; pmc; pmc = nextpmc) {
		nextpmc = pmc->next;
		ip6_mc_clear_src(pmc);
		in6_dev_put(pmc->idev);
		kfree(pmc);
	}

	/* clear dead sources, too */
	read_lock_bh(&idev->lock);
	for (pmc=idev->mc_list; pmc; pmc=pmc->next) {
		struct ip6_sf_list *psf, *psf_next;

		spin_lock_bh(&pmc->mca_lock);
		psf = pmc->mca_tomb;
		pmc->mca_tomb = NULL;
		spin_unlock_bh(&pmc->mca_lock);
		for (; psf; psf=psf_next) {
			psf_next = psf->sf_next;
			kfree(psf);
		}
	}
	read_unlock_bh(&idev->lock);
}


/*
 *	device multicast group inc (add if not found)
 */
int ipv6_dev_mc_inc(struct net_device *dev, struct in6_addr *addr)
{
	struct ifmcaddr6 *mc;
	struct inet6_dev *idev;

	idev = in6_dev_get(dev);

	if (idev == NULL)
		return -EINVAL;

	write_lock_bh(&idev->lock);
	if (idev->dead) {
		write_unlock_bh(&idev->lock);
		in6_dev_put(idev);
		return -ENODEV;
	}

	for (mc = idev->mc_list; mc; mc = mc->next) {
		if (ipv6_addr_cmp(&mc->mca_addr, addr) == 0) {
			mc->mca_users++;
			write_unlock_bh(&idev->lock);
			ip6_mc_add_src(idev, &mc->mca_addr, MCAST_EXCLUDE, 0,
				NULL, 0);
			in6_dev_put(idev);
			return 0;
		}
	}

	/*
	 *	not found: create a new one.
	 */

	mc = kmalloc(sizeof(struct ifmcaddr6), GFP_ATOMIC);

	if (mc == NULL) {
		write_unlock_bh(&idev->lock);
		in6_dev_put(idev);
		return -ENOMEM;
	}

	memset(mc, 0, sizeof(struct ifmcaddr6));
	init_timer(&mc->mca_timer);
	mc->mca_timer.function = igmp6_timer_handler;
	mc->mca_timer.data = (unsigned long) mc;

	ipv6_addr_copy(&mc->mca_addr, addr);
	mc->idev = idev;
	mc->mca_users = 1;
	/* mca_stamp should be updated upon changes */
	mc->mca_cstamp = mc->mca_tstamp = jiffies;
	atomic_set(&mc->mca_refcnt, 2);
	mc->mca_lock = SPIN_LOCK_UNLOCKED;

	/* initial mode is (EX, empty) */
	mc->mca_sfmode = MCAST_EXCLUDE;
	mc->mca_sfcount[MCAST_EXCLUDE] = 1;

	if (ipv6_addr_is_ll_all_nodes(&mc->mca_addr) ||
	    IPV6_ADDR_MC_SCOPE(&mc->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
		mc->mca_flags |= MAF_NOREPORT;

	mc->next = idev->mc_list;
	idev->mc_list = mc;
	write_unlock_bh(&idev->lock);

	mld_del_delrec(idev, &mc->mca_addr);
	igmp6_group_added(mc);
	ma_put(mc);
	return 0;
}

/*
 *	device multicast group del
 */
int __ipv6_dev_mc_dec(struct inet6_dev *idev, struct in6_addr *addr)
{
	struct ifmcaddr6 *ma, **map;

	write_lock_bh(&idev->lock);
	for (map = &idev->mc_list; (ma=*map) != NULL; map = &ma->next) {
		if (ipv6_addr_cmp(&ma->mca_addr, addr) == 0) {
			if (--ma->mca_users == 0) {
				*map = ma->next;
				write_unlock_bh(&idev->lock);

				igmp6_group_dropped(ma);

				ma_put(ma);
				return 0;
			}
			write_unlock_bh(&idev->lock);
			return 0;
		}
	}
	write_unlock_bh(&idev->lock);

	return -ENOENT;
}

int ipv6_dev_mc_dec(struct net_device *dev, struct in6_addr *addr)
{
	struct inet6_dev *idev = in6_dev_get(dev);
	int err;

	if (!idev)
		return -ENODEV;

	err = __ipv6_dev_mc_dec(idev, addr);

	in6_dev_put(idev);

	return err;
}

/*
 * identify MLD packets for MLD filter exceptions
 */
int ipv6_is_mld(struct sk_buff *skb, int nexthdr)
{
	struct icmp6hdr *pic;

	if (nexthdr != IPPROTO_ICMPV6)
		return 0;

	if (!pskb_may_pull(skb, sizeof(struct icmp6hdr)))
		return 0;

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

	switch (pic->icmp6_type) {
	case ICMPV6_MGM_QUERY:
	case ICMPV6_MGM_REPORT:
	case ICMPV6_MGM_REDUCTION:
	case ICMPV6_MLD2_REPORT:
		return 1;
	default:
		break;
	}
	return 0;
}

/*
 *	check if the interface/address pair is valid
 */
int ipv6_chk_mcast_addr(struct net_device *dev, struct in6_addr *group,
	struct in6_addr *src_addr)
{
	struct inet6_dev *idev;
	struct ifmcaddr6 *mc;
	int rv = 0;

	idev = in6_dev_get(dev);
	if (idev) {
		read_lock_bh(&idev->lock);
		for (mc = idev->mc_list; mc; mc=mc->next) {
			if (ipv6_addr_cmp(&mc->mca_addr, group) == 0)
				break;
		}
		if (mc) {
			if (src_addr && !ipv6_addr_any(src_addr)) {
				struct ip6_sf_list *psf;

				spin_lock_bh(&mc->mca_lock);
				for (psf=mc->mca_sources;psf;psf=psf->sf_next) {
					if (ipv6_addr_cmp(&psf->sf_addr,
					    src_addr) == 0)
						break;
				}
				if (psf)
					rv = psf->sf_count[MCAST_INCLUDE] ||
						psf->sf_count[MCAST_EXCLUDE] !=
						mc->mca_sfcount[MCAST_EXCLUDE];
				else
					rv = mc->mca_sfcount[MCAST_EXCLUDE] !=0;
				spin_unlock_bh(&mc->mca_lock);
			} else
				rv = 1; /* don't filter unspecified source */
		}
		read_unlock_bh(&idev->lock);
		in6_dev_put(idev);
	}
	return rv;
}

static void mld_gq_start_timer(struct inet6_dev *idev)
{
	int tv = net_random() % idev->mc_maxdelay;

	idev->mc_gq_running = 1;
	if (!mod_timer(&idev->mc_gq_timer, jiffies+tv+2))
		in6_dev_hold(idev);
}

static void mld_ifc_start_timer(struct inet6_dev *idev, int delay)
{
	int tv = net_random() % delay;

	if (!mod_timer(&idev->mc_ifc_timer, jiffies+tv+2))
		in6_dev_hold(idev);
}

/*
 *	IGMP handling (alias multicast ICMPv6 messages)
 */

static void igmp6_group_queried(struct ifmcaddr6 *ma, unsigned long resptime)
{
	unsigned long delay = resptime;

	/* Do not start timer for these addresses */
	if (ipv6_addr_is_ll_all_nodes(&ma->mca_addr) ||
	    IPV6_ADDR_MC_SCOPE(&ma->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
		return;

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

	if (delay >= resptime) {
		if (resptime)
			delay = net_random() % resptime;
		else
			delay = 1;
	}
	ma->mca_timer.expires = jiffies + delay;
	if (!mod_timer(&ma->mca_timer, jiffies + delay))
		atomic_inc(&ma->mca_refcnt);
	ma->mca_flags |= MAF_TIMER_RUNNING;
}

static void mld_marksources(struct ifmcaddr6 *pmc, int nsrcs,
	struct in6_addr *srcs)
{
	struct ip6_sf_list *psf;
	int i, scount;

	scount = 0;
	for (psf=pmc->mca_sources; psf; psf=psf->sf_next) {
		if (scount == nsrcs)
			break;
		for (i=0; i<nsrcs; i++)
			if (ipv6_addr_cmp(&srcs[i], &psf->sf_addr) == 0) {
				psf->sf_gsresp = 1;
				scount++;
				break;
			}
	}
}

int igmp6_event_query(struct sk_buff *skb)
{
	struct mld2_query *mlh2 = (struct mld2_query *) skb->h.raw;
	struct ifmcaddr6 *ma;
	struct in6_addr *group;
	unsigned long max_delay;
	struct inet6_dev *idev;
	struct icmp6hdr *hdr;
	int group_type;
	int mark = 0;
	int len;

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

	/* compute payload length excluding extension headers */
	len = ntohs(skb->nh.ipv6h->payload_len) + sizeof(struct ipv6hdr);
	len -= (char *)skb->h.raw - (char *)skb->nh.ipv6h; 

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

	idev = in6_dev_get(skb->dev);

	if (idev == NULL)
		return 0;

	hdr = (struct icmp6hdr *) skb->h.raw;
	group = (struct in6_addr *) (hdr + 1);
	group_type = ipv6_addr_type(group);

	if (group_type != IPV6_ADDR_ANY &&
	    !(group_type&IPV6_ADDR_MULTICAST)) {
		in6_dev_put(idev);
		return -EINVAL;
	}

	if (len == 24) {
		int switchback;
		/* MLDv1 router present */

		/* Translate milliseconds to jiffies */
		max_delay = (ntohs(hdr->icmp6_maxdelay)*HZ)/1000;

		switchback = (idev->mc_qrv + 1) * max_delay;
		idev->mc_v1_seen = jiffies + switchback;

		/* cancel the interface change timer */
		idev->mc_ifc_count = 0;
		if (del_timer(&idev->mc_ifc_timer))
			__in6_dev_put(idev);
		/* clear deleted report items */
		mld_clear_delrec(idev);
	} else if (len >= 28) {
		max_delay = (MLDV2_MRC(ntohs(mlh2->mrc))*HZ)/1000;
		if (!max_delay)
			max_delay = 1;
		idev->mc_maxdelay = max_delay;
		if (mlh2->qrv)
			idev->mc_qrv = mlh2->qrv;
		if (group_type == IPV6_ADDR_ANY) { /* general query */
			if (mlh2->nsrcs) {
				in6_dev_put(idev);
				return -EINVAL; /* no sources allowed */
			}
			mld_gq_start_timer(idev);
			in6_dev_put(idev);
			return 0;
		}
		/* mark sources to include, if group & source-specific */
		mark = mlh2->nsrcs != 0;
	} else {
		in6_dev_put(idev);
		return -EINVAL;
	}

	read_lock_bh(&idev->lock);
	if (group_type == IPV6_ADDR_ANY) {
		for (ma = idev->mc_list; ma; ma=ma->next) {
			spin_lock_bh(&ma->mca_lock);
			igmp6_group_queried(ma, max_delay);
			spin_unlock_bh(&ma->mca_lock);
		}
	} else {
		for (ma = idev->mc_list; ma; ma=ma->next) {
			if (group_type != IPV6_ADDR_ANY &&
			    ipv6_addr_cmp(group, &ma->mca_addr) != 0)
				continue;
			spin_lock_bh(&ma->mca_lock);
			if (ma->mca_flags & MAF_TIMER_RUNNING) {
				/* gsquery <- gsquery && mark */
				if (!mark)
					ma->mca_flags &= ~MAF_GSQUERY;
			} else {
				/* gsquery <- mark */
				if (mark)
					ma->mca_flags |= MAF_GSQUERY;
				else
					ma->mca_flags &= ~MAF_GSQUERY;
			}
			if (ma->mca_flags & MAF_GSQUERY)
				mld_marksources(ma, ntohs(mlh2->nsrcs),
					mlh2->srcs);
			igmp6_group_queried(ma, max_delay);
			spin_unlock_bh(&ma->mca_lock);
			if (group_type != IPV6_ADDR_ANY)
				break;
		}
	}
	read_unlock_bh(&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;
	int addr_type;

	/* 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 */
	addr_type = ipv6_addr_type(&skb->nh.ipv6h->saddr);
	if (addr_type != IPV6_ADDR_ANY && 
	    !(addr_type&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_bh(&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_bh(&idev->lock);
	in6_dev_put(idev);
	return 0;
}

static int is_in(struct ifmcaddr6 *pmc, struct ip6_sf_list *psf, int type,
	int gdeleted, int sdeleted)
{
	switch (type) {
	case MLD2_MODE_IS_INCLUDE:
	case MLD2_MODE_IS_EXCLUDE:
		if (gdeleted || sdeleted)
			return 0;
		return !((pmc->mca_flags & MAF_GSQUERY) && !psf->sf_gsresp);
	case MLD2_CHANGE_TO_INCLUDE:
		if (gdeleted || sdeleted)
			return 0;
		return psf->sf_count[MCAST_INCLUDE] != 0;
	case MLD2_CHANGE_TO_EXCLUDE:
		if (gdeleted || sdeleted)
			return 0;
		if (pmc->mca_sfcount[MCAST_EXCLUDE] == 0 ||
		    psf->sf_count[MCAST_INCLUDE])
			return 0;
		return pmc->mca_sfcount[MCAST_EXCLUDE] ==
			psf->sf_count[MCAST_EXCLUDE];
	case MLD2_ALLOW_NEW_SOURCES:
		if (gdeleted || !psf->sf_crcount)
			return 0;
		return (pmc->mca_sfmode == MCAST_INCLUDE) ^ sdeleted;
	case MLD2_BLOCK_OLD_SOURCES:
		if (pmc->mca_sfmode == MCAST_INCLUDE)
			return gdeleted || (psf->sf_crcount && sdeleted);
		return psf->sf_crcount && !gdeleted && !sdeleted;
	}
	return 0;
}