mcast.c

linux 内核源代码

		if (pmc->ifindex != gsf->gf_interface)
			continue;
		if (ipv6_addr_equal(&pmc->addr, group))
			break;
	}
	if (!pmc) {		/* must have a prior join */
		err = -EINVAL;
		goto done;
	}
	if (gsf->gf_numsrc) {
		newpsl = sock_kmalloc(sk, IP6_SFLSIZE(gsf->gf_numsrc),
							  GFP_ATOMIC);
		if (!newpsl) {
			err = -ENOBUFS;
			goto done;
		}
		newpsl->sl_max = newpsl->sl_count = gsf->gf_numsrc;
		for (i=0; i<newpsl->sl_count; ++i) {
			struct sockaddr_in6 *psin6;

			psin6 = (struct sockaddr_in6 *)&gsf->gf_slist[i];
			newpsl->sl_addr[i] = psin6->sin6_addr;
		}
		err = ip6_mc_add_src(idev, group, gsf->gf_fmode,
			newpsl->sl_count, newpsl->sl_addr, 0);
		if (err) {
			sock_kfree_s(sk, newpsl, IP6_SFLSIZE(newpsl->sl_max));
			goto done;
		}
	} else {
		newpsl = NULL;
		(void) ip6_mc_add_src(idev, group, gsf->gf_fmode, 0, NULL, 0);
	}

	write_lock_bh(&pmc->sflock);
	psl = pmc->sflist;
	if (psl) {
		(void) ip6_mc_del_src(idev, group, pmc->sfmode,
			psl->sl_count, psl->sl_addr, 0);
		sock_kfree_s(sk, psl, IP6_SFLSIZE(psl->sl_max));
	} else
		(void) ip6_mc_del_src(idev, group, pmc->sfmode, 0, NULL, 0);
	pmc->sflist = newpsl;
	pmc->sfmode = gsf->gf_fmode;
	write_unlock_bh(&pmc->sflock);
	err = 0;
done:
	read_unlock_bh(&ipv6_sk_mc_lock);
	read_unlock_bh(&idev->lock);
	in6_dev_put(idev);
	dev_put(dev);
	if (leavegroup)
		err = ipv6_sock_mc_drop(sk, gsf->gf_interface, group);
	return err;
}

int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
	struct group_filter __user *optval, int __user *optlen)
{
	int err, i, count, copycount;
	struct in6_addr *group;
	struct ipv6_mc_socklist *pmc;
	struct inet6_dev *idev;
	struct net_device *dev;
	struct ipv6_pinfo *inet6 = inet6_sk(sk);
	struct ip6_sf_socklist *psl;

	group = &((struct sockaddr_in6 *)&gsf->gf_group)->sin6_addr;

	if (!ipv6_addr_is_multicast(group))
		return -EINVAL;

	idev = ip6_mc_find_dev(group, gsf->gf_interface);

	if (!idev)
		return -ENODEV;

	dev = idev->dev;

	err = -EADDRNOTAVAIL;
	/*
	 * changes to the ipv6_mc_list require the socket lock and
	 * a read lock on ip6_sk_mc_lock. We have the socket lock,
	 * so reading the list is safe.
	 */

	for (pmc=inet6->ipv6_mc_list; pmc; pmc=pmc->next) {
		if (pmc->ifindex != gsf->gf_interface)
			continue;
		if (ipv6_addr_equal(group, &pmc->addr))
			break;
	}
	if (!pmc)		/* must have a prior join */
		goto done;
	gsf->gf_fmode = pmc->sfmode;
	psl = pmc->sflist;
	count = psl ? psl->sl_count : 0;
	read_unlock_bh(&idev->lock);
	in6_dev_put(idev);
	dev_put(dev);

	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
	gsf->gf_numsrc = count;
	if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
	    copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
		return -EFAULT;
	}
	/* changes to psl require the socket lock, a read lock on
	 * on ipv6_sk_mc_lock and a write lock on pmc->sflock. We
	 * have the socket lock, so reading here is safe.
	 */
	for (i=0; i<copycount; i++) {
		struct sockaddr_in6 *psin6;
		struct sockaddr_storage ss;

		psin6 = (struct sockaddr_in6 *)&ss;
		memset(&ss, 0, sizeof(ss));
		psin6->sin6_family = AF_INET6;
		psin6->sin6_addr = psl->sl_addr[i];
		if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
			return -EFAULT;
	}
	return 0;
done:
	read_unlock_bh(&idev->lock);
	in6_dev_put(idev);
	dev_put(dev);
	return err;
}

int inet6_mc_check(struct sock *sk, struct in6_addr *mc_addr,
	struct in6_addr *src_addr)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct ipv6_mc_socklist *mc;
	struct ip6_sf_socklist *psl;
	int rv = 1;

	read_lock(&ipv6_sk_mc_lock);
	for (mc = np->ipv6_mc_list; mc; mc = mc->next) {
		if (ipv6_addr_equal(&mc->addr, mc_addr))
			break;
	}
	if (!mc) {
		read_unlock(&ipv6_sk_mc_lock);
		return 1;
	}
	read_lock(&mc->sflock);
	psl = mc->sflist;
	if (!psl) {
		rv = mc->sfmode == MCAST_EXCLUDE;
	} else {
		int i;

		for (i=0; i<psl->sl_count; i++) {
			if (ipv6_addr_equal(&psl->sl_addr[i], src_addr))
				break;
		}
		if (mc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
			rv = 0;
		if (mc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
			rv = 0;
	}
	read_unlock(&mc->sflock);
	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 = kzalloc(sizeof(*pmc), GFP_ATOMIC);
	if (!pmc)
		return;

	spin_lock_bh(&im->mca_lock);
	spin_lock_init(&pmc->mca_lock);
	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_equal(&pmc->mca_addr, pmca))
			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_equal(&mc->mca_addr, addr)) {
			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 = kzalloc(sizeof(struct ifmcaddr6), GFP_ATOMIC);

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

	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);
	spin_lock_init(&mc->mca_lock);

	/* 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_equal(&ma->mca_addr, addr)) {
			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 = icmp6_hdr(skb);

	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_equal(&mc->mca_addr, group))
				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_equal(&psf->sf_addr, src_addr))
						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);
}