igmp.c

linux 内核源代码

		return;
	spin_lock_bh(&im->lock);
	pmc->interface = im->interface;
	in_dev_hold(in_dev);
	pmc->multiaddr = im->multiaddr;
	pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
		IGMP_Unsolicited_Report_Count;
	pmc->sfmode = im->sfmode;
	if (pmc->sfmode == MCAST_INCLUDE) {
		struct ip_sf_list *psf;

		pmc->tomb = im->tomb;
		pmc->sources = im->sources;
		im->tomb = im->sources = NULL;
		for (psf=pmc->sources; psf; psf=psf->sf_next)
			psf->sf_crcount = pmc->crcount;
	}
	spin_unlock_bh(&im->lock);

	spin_lock_bh(&in_dev->mc_tomb_lock);
	pmc->next = in_dev->mc_tomb;
	in_dev->mc_tomb = pmc;
	spin_unlock_bh(&in_dev->mc_tomb_lock);
}

static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr)
{
	struct ip_mc_list *pmc, *pmc_prev;
	struct ip_sf_list *psf, *psf_next;

	spin_lock_bh(&in_dev->mc_tomb_lock);
	pmc_prev = NULL;
	for (pmc=in_dev->mc_tomb; pmc; pmc=pmc->next) {
		if (pmc->multiaddr == multiaddr)
			break;
		pmc_prev = pmc;
	}
	if (pmc) {
		if (pmc_prev)
			pmc_prev->next = pmc->next;
		else
			in_dev->mc_tomb = pmc->next;
	}
	spin_unlock_bh(&in_dev->mc_tomb_lock);
	if (pmc) {
		for (psf=pmc->tomb; psf; psf=psf_next) {
			psf_next = psf->sf_next;
			kfree(psf);
		}
		in_dev_put(pmc->interface);
		kfree(pmc);
	}
}

static void igmpv3_clear_delrec(struct in_device *in_dev)
{
	struct ip_mc_list *pmc, *nextpmc;

	spin_lock_bh(&in_dev->mc_tomb_lock);
	pmc = in_dev->mc_tomb;
	in_dev->mc_tomb = NULL;
	spin_unlock_bh(&in_dev->mc_tomb_lock);

	for (; pmc; pmc = nextpmc) {
		nextpmc = pmc->next;
		ip_mc_clear_src(pmc);
		in_dev_put(pmc->interface);
		kfree(pmc);
	}
	/* clear dead sources, too */
	read_lock(&in_dev->mc_list_lock);
	for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
		struct ip_sf_list *psf, *psf_next;

		spin_lock_bh(&pmc->lock);
		psf = pmc->tomb;
		pmc->tomb = NULL;
		spin_unlock_bh(&pmc->lock);
		for (; psf; psf=psf_next) {
			psf_next = psf->sf_next;
			kfree(psf);
		}
	}
	read_unlock(&in_dev->mc_list_lock);
}
#endif

static void igmp_group_dropped(struct ip_mc_list *im)
{
	struct in_device *in_dev = im->interface;
#ifdef CONFIG_IP_MULTICAST
	int reporter;
#endif

	if (im->loaded) {
		im->loaded = 0;
		ip_mc_filter_del(in_dev, im->multiaddr);
	}

#ifdef CONFIG_IP_MULTICAST
	if (im->multiaddr == IGMP_ALL_HOSTS)
		return;

	reporter = im->reporter;
	igmp_stop_timer(im);

	if (!in_dev->dead) {
		if (IGMP_V1_SEEN(in_dev))
			goto done;
		if (IGMP_V2_SEEN(in_dev)) {
			if (reporter)
				igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
			goto done;
		}
		/* IGMPv3 */
		igmpv3_add_delrec(in_dev, im);

		igmp_ifc_event(in_dev);
	}
done:
#endif
	ip_mc_clear_src(im);
}

static void igmp_group_added(struct ip_mc_list *im)
{
	struct in_device *in_dev = im->interface;

	if (im->loaded == 0) {
		im->loaded = 1;
		ip_mc_filter_add(in_dev, im->multiaddr);
	}

#ifdef CONFIG_IP_MULTICAST
	if (im->multiaddr == IGMP_ALL_HOSTS)
		return;

	if (in_dev->dead)
		return;
	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
		spin_lock_bh(&im->lock);
		igmp_start_timer(im, IGMP_Initial_Report_Delay);
		spin_unlock_bh(&im->lock);
		return;
	}
	/* else, v3 */

	im->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
		IGMP_Unsolicited_Report_Count;
	igmp_ifc_event(in_dev);
#endif
}


/*
 *	Multicast list managers
 */


/*
 *	A socket has joined a multicast group on device dev.
 */

void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
{
	struct ip_mc_list *im;

	ASSERT_RTNL();

	for (im=in_dev->mc_list; im; im=im->next) {
		if (im->multiaddr == addr) {
			im->users++;
			ip_mc_add_src(in_dev, &addr, MCAST_EXCLUDE, 0, NULL, 0);
			goto out;
		}
	}

	im = kmalloc(sizeof(*im), GFP_KERNEL);
	if (!im)
		goto out;

	im->users=1;
	im->interface=in_dev;
	in_dev_hold(in_dev);
	im->multiaddr=addr;
	/* initial mode is (EX, empty) */
	im->sfmode = MCAST_EXCLUDE;
	im->sfcount[MCAST_INCLUDE] = 0;
	im->sfcount[MCAST_EXCLUDE] = 1;
	im->sources = NULL;
	im->tomb = NULL;
	im->crcount = 0;
	atomic_set(&im->refcnt, 1);
	spin_lock_init(&im->lock);
#ifdef CONFIG_IP_MULTICAST
	im->tm_running=0;
	init_timer(&im->timer);
	im->timer.data=(unsigned long)im;
	im->timer.function=&igmp_timer_expire;
	im->unsolicit_count = IGMP_Unsolicited_Report_Count;
	im->reporter = 0;
	im->gsquery = 0;
#endif
	im->loaded = 0;
	write_lock_bh(&in_dev->mc_list_lock);
	im->next=in_dev->mc_list;
	in_dev->mc_list=im;
	write_unlock_bh(&in_dev->mc_list_lock);
#ifdef CONFIG_IP_MULTICAST
	igmpv3_del_delrec(in_dev, im->multiaddr);
#endif
	igmp_group_added(im);
	if (!in_dev->dead)
		ip_rt_multicast_event(in_dev);
out:
	return;
}

/*
 *	Resend IGMP JOIN report; used for bonding.
 */
void ip_mc_rejoin_group(struct ip_mc_list *im)
{
#ifdef CONFIG_IP_MULTICAST
	struct in_device *in_dev = im->interface;

	if (im->multiaddr == IGMP_ALL_HOSTS)
		return;

	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
		igmp_mod_timer(im, IGMP_Initial_Report_Delay);
		return;
	}
	/* else, v3 */
	im->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
		IGMP_Unsolicited_Report_Count;
	igmp_ifc_event(in_dev);
#endif
}

/*
 *	A socket has left a multicast group on device dev
 */

void ip_mc_dec_group(struct in_device *in_dev, __be32 addr)
{
	struct ip_mc_list *i, **ip;

	ASSERT_RTNL();

	for (ip=&in_dev->mc_list; (i=*ip)!=NULL; ip=&i->next) {
		if (i->multiaddr==addr) {
			if (--i->users == 0) {
				write_lock_bh(&in_dev->mc_list_lock);
				*ip = i->next;
				write_unlock_bh(&in_dev->mc_list_lock);
				igmp_group_dropped(i);

				if (!in_dev->dead)
					ip_rt_multicast_event(in_dev);

				ip_ma_put(i);
				return;
			}
			break;
		}
	}
}

/* Device going down */

void ip_mc_down(struct in_device *in_dev)
{
	struct ip_mc_list *i;

	ASSERT_RTNL();

	for (i=in_dev->mc_list; i; i=i->next)
		igmp_group_dropped(i);

#ifdef CONFIG_IP_MULTICAST
	in_dev->mr_ifc_count = 0;
	if (del_timer(&in_dev->mr_ifc_timer))
		__in_dev_put(in_dev);
	in_dev->mr_gq_running = 0;
	if (del_timer(&in_dev->mr_gq_timer))
		__in_dev_put(in_dev);
	igmpv3_clear_delrec(in_dev);
#endif

	ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
}

void ip_mc_init_dev(struct in_device *in_dev)
{
	ASSERT_RTNL();

	in_dev->mc_tomb = NULL;
#ifdef CONFIG_IP_MULTICAST
	in_dev->mr_gq_running = 0;
	init_timer(&in_dev->mr_gq_timer);
	in_dev->mr_gq_timer.data=(unsigned long) in_dev;
	in_dev->mr_gq_timer.function=&igmp_gq_timer_expire;
	in_dev->mr_ifc_count = 0;
	init_timer(&in_dev->mr_ifc_timer);
	in_dev->mr_ifc_timer.data=(unsigned long) in_dev;
	in_dev->mr_ifc_timer.function=&igmp_ifc_timer_expire;
	in_dev->mr_qrv = IGMP_Unsolicited_Report_Count;
#endif

	rwlock_init(&in_dev->mc_list_lock);
	spin_lock_init(&in_dev->mc_tomb_lock);
}

/* Device going up */

void ip_mc_up(struct in_device *in_dev)
{
	struct ip_mc_list *i;

	ASSERT_RTNL();

	ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);

	for (i=in_dev->mc_list; i; i=i->next)
		igmp_group_added(i);
}

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

void ip_mc_destroy_dev(struct in_device *in_dev)
{
	struct ip_mc_list *i;

	ASSERT_RTNL();

	/* Deactivate timers */
	ip_mc_down(in_dev);

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

		igmp_group_dropped(i);
		ip_ma_put(i);

		write_lock_bh(&in_dev->mc_list_lock);
	}
	write_unlock_bh(&in_dev->mc_list_lock);
}

static struct in_device * ip_mc_find_dev(struct ip_mreqn *imr)
{
	struct flowi fl = { .nl_u = { .ip4_u =
				      { .daddr = imr->imr_multiaddr.s_addr } } };
	struct rtable *rt;
	struct net_device *dev = NULL;
	struct in_device *idev = NULL;

	if (imr->imr_ifindex) {
		idev = inetdev_by_index(imr->imr_ifindex);
		if (idev)
			__in_dev_put(idev);
		return idev;
	}
	if (imr->imr_address.s_addr) {
		dev = ip_dev_find(imr->imr_address.s_addr);
		if (!dev)
			return NULL;
		dev_put(dev);
	}

	if (!dev && !ip_route_output_key(&rt, &fl)) {
		dev = rt->u.dst.dev;
		ip_rt_put(rt);
	}
	if (dev) {
		imr->imr_ifindex = dev->ifindex;
		idev = __in_dev_get_rtnl(dev);
	}
	return idev;
}

/*
 *	Join a socket to a group
 */
int sysctl_igmp_max_memberships __read_mostly = IP_MAX_MEMBERSHIPS;
int sysctl_igmp_max_msf __read_mostly = IP_MAX_MSF;


static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
	__be32 *psfsrc)
{
	struct ip_sf_list *psf, *psf_prev;
	int rv = 0;

	psf_prev = NULL;
	for (psf=pmc->sources; psf; psf=psf->sf_next) {
		if (psf->sf_inaddr == *psfsrc)
			break;
		psf_prev = psf;
	}
	if (!psf || psf->sf_count[sfmode] == 0) {
		/* source filter not found, or count wrong =>  bug */
		return -ESRCH;
	}
	psf->sf_count[sfmode]--;
	if (psf->sf_count[sfmode] == 0) {
		ip_rt_multicast_event(pmc->interface);
	}
	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
#ifdef CONFIG_IP_MULTICAST
		struct in_device *in_dev = pmc->interface;
#endif

		/* no more filters for this source */
		if (psf_prev)
			psf_prev->sf_next = psf->sf_next;
		else
			pmc->sources = psf->sf_next;
#ifdef CONFIG_IP_MULTICAST
		if (psf->sf_oldin &&
		    !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
			psf->sf_crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
				IGMP_Unsolicited_Report_Count;
			psf->sf_next = pmc->tomb;
			pmc->tomb = psf;
			rv = 1;
		} else
#endif
			kfree(psf);
	}
	return rv;
}

#ifndef CONFIG_IP_MULTICAST
#define igmp_ifc_event(x)	do { } while (0)
#endif

static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
			 int sfcount, __be32 *psfsrc, int delta)
{
	struct ip_mc_list *pmc;
	int	changerec = 0;
	int	i, err;

	if (!in_dev)
		return -ENODEV;
	read_lock(&in_dev->mc_list_lock);
	for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
		if (*pmca == pmc->multiaddr)
			break;
	}
	if (!pmc) {
		/* MCA not found?? bug */
		read_unlock(&in_dev->mc_list_lock);
		return -ESRCH;
	}
	spin_lock_bh(&pmc->lock);
	read_unlock(&in_dev->mc_list_lock);
#ifdef CONFIG_IP_MULTICAST
	sf_markstate(pmc);
#endif
	if (!delta) {
		err = -EINVAL;
		if (!pmc->sfcount[sfmode])
			goto out_unlock;
		pmc->sfcount[sfmode]--;
	}
	err = 0;
	for (i=0; i<sfcount; i++) {
		int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);

		changerec |= rv > 0;
		if (!err && rv < 0)
			err = rv;
	}
	if (pmc->sfmode == MCAST_EXCLUDE &&
	    pmc->sfcount[MCAST_EXCLUDE] == 0 &&
	    pmc->sfcount[MCAST_INCLUDE]) {
#ifdef CONFIG_IP_MULTICAST
		struct ip_sf_list *psf;
#endif

		/* filter mode change */
		pmc->sfmode = MCAST_INCLUDE;
#ifdef CONFIG_IP_MULTICAST
		pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
			IGMP_Unsolicited_Report_Count;
		in_dev->mr_ifc_count = pmc->crcount;
		for (psf=pmc->sources; psf; psf = psf->sf_next)
			psf->sf_crcount = 0;
		igmp_ifc_event(pmc->interface);
	} else if (sf_setstate(pmc) || changerec) {
		igmp_ifc_event(pmc->interface);
#endif
	}
out_unlock:
	spin_unlock_bh(&pmc->lock);
	return err;
}

/*
 * Add multicast single-source filter to the interface list
 */
static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
	__be32 *psfsrc, int delta)
{
	struct ip_sf_list *psf, *psf_prev;

	psf_prev = NULL;
	for (psf=pmc->sources; psf; psf=psf->sf_next) {
		if (psf->sf_inaddr == *psfsrc)
			break;
		psf_prev = psf;
	}
	if (!psf) {