igmp.c

linux 内核源代码

		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
		if (!psf)
			return -ENOBUFS;
		psf->sf_inaddr = *psfsrc;
		if (psf_prev) {
			psf_prev->sf_next = psf;
		} else
			pmc->sources = psf;
	}
	psf->sf_count[sfmode]++;
	if (psf->sf_count[sfmode] == 1) {
		ip_rt_multicast_event(pmc->interface);
	}
	return 0;
}

#ifdef CONFIG_IP_MULTICAST
static void sf_markstate(struct ip_mc_list *pmc)
{
	struct ip_sf_list *psf;
	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];

	for (psf=pmc->sources; psf; psf=psf->sf_next)
		if (pmc->sfcount[MCAST_EXCLUDE]) {
			psf->sf_oldin = mca_xcount ==
				psf->sf_count[MCAST_EXCLUDE] &&
				!psf->sf_count[MCAST_INCLUDE];
		} else
			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
}

static int sf_setstate(struct ip_mc_list *pmc)
{
	struct ip_sf_list *psf, *dpsf;
	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
	int qrv = pmc->interface->mr_qrv;
	int new_in, rv;

	rv = 0;
	for (psf=pmc->sources; psf; psf=psf->sf_next) {
		if (pmc->sfcount[MCAST_EXCLUDE]) {
			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
				!psf->sf_count[MCAST_INCLUDE];
		} else
			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
		if (new_in) {
			if (!psf->sf_oldin) {
				struct ip_sf_list *prev = NULL;

				for (dpsf=pmc->tomb; dpsf; dpsf=dpsf->sf_next) {
					if (dpsf->sf_inaddr == psf->sf_inaddr)
						break;
					prev = dpsf;
				}
				if (dpsf) {
					if (prev)
						prev->sf_next = dpsf->sf_next;
					else
						pmc->tomb = dpsf->sf_next;
					kfree(dpsf);
				}
				psf->sf_crcount = qrv;
				rv++;
			}
		} else if (psf->sf_oldin) {

			psf->sf_crcount = 0;
			/*
			 * add or update "delete" records if an active filter
			 * is now inactive
			 */
			for (dpsf=pmc->tomb; dpsf; dpsf=dpsf->sf_next)
				if (dpsf->sf_inaddr == psf->sf_inaddr)
					break;
			if (!dpsf) {
				dpsf = (struct ip_sf_list *)
					kmalloc(sizeof(*dpsf), GFP_ATOMIC);
				if (!dpsf)
					continue;
				*dpsf = *psf;
				/* pmc->lock held by callers */
				dpsf->sf_next = pmc->tomb;
				pmc->tomb = dpsf;
			}
			dpsf->sf_crcount = qrv;
			rv++;
		}
	}
	return rv;
}
#endif

/*
 * Add multicast source filter list to the interface list
 */
static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
			 int sfcount, __be32 *psfsrc, int delta)
{
	struct ip_mc_list *pmc;
	int	isexclude;
	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
	isexclude = pmc->sfmode == MCAST_EXCLUDE;
	if (!delta)
		pmc->sfcount[sfmode]++;
	err = 0;
	for (i=0; i<sfcount; i++) {
		err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i], delta);
		if (err)
			break;
	}
	if (err) {
		int j;

		pmc->sfcount[sfmode]--;
		for (j=0; j<i; j++)
			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
#ifdef CONFIG_IP_MULTICAST
		struct ip_sf_list *psf;
		in_dev = pmc->interface;
#endif

		/* filter mode change */
		if (pmc->sfcount[MCAST_EXCLUDE])
			pmc->sfmode = MCAST_EXCLUDE;
		else if (pmc->sfcount[MCAST_INCLUDE])
			pmc->sfmode = MCAST_INCLUDE;
#ifdef CONFIG_IP_MULTICAST
		/* else no filters; keep old mode for reports */

		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(in_dev);
	} else if (sf_setstate(pmc)) {
		igmp_ifc_event(in_dev);
#endif
	}
	spin_unlock_bh(&pmc->lock);
	return err;
}

static void ip_mc_clear_src(struct ip_mc_list *pmc)
{
	struct ip_sf_list *psf, *nextpsf;

	for (psf=pmc->tomb; psf; psf=nextpsf) {
		nextpsf = psf->sf_next;
		kfree(psf);
	}
	pmc->tomb = NULL;
	for (psf=pmc->sources; psf; psf=nextpsf) {
		nextpsf = psf->sf_next;
		kfree(psf);
	}
	pmc->sources = NULL;
	pmc->sfmode = MCAST_EXCLUDE;
	pmc->sfcount[MCAST_INCLUDE] = 0;
	pmc->sfcount[MCAST_EXCLUDE] = 1;
}


/*
 * Join a multicast group
 */
int ip_mc_join_group(struct sock *sk , struct ip_mreqn *imr)
{
	int err;
	__be32 addr = imr->imr_multiaddr.s_addr;
	struct ip_mc_socklist *iml=NULL, *i;
	struct in_device *in_dev;
	struct inet_sock *inet = inet_sk(sk);
	int ifindex;
	int count = 0;

	if (!MULTICAST(addr))
		return -EINVAL;

	rtnl_lock();

	in_dev = ip_mc_find_dev(imr);

	if (!in_dev) {
		iml = NULL;
		err = -ENODEV;
		goto done;
	}

	err = -EADDRINUSE;
	ifindex = imr->imr_ifindex;
	for (i = inet->mc_list; i; i = i->next) {
		if (i->multi.imr_multiaddr.s_addr == addr &&
		    i->multi.imr_ifindex == ifindex)
			goto done;
		count++;
	}
	err = -ENOBUFS;
	if (count >= sysctl_igmp_max_memberships)
		goto done;
	iml = sock_kmalloc(sk,sizeof(*iml),GFP_KERNEL);
	if (iml == NULL)
		goto done;

	memcpy(&iml->multi, imr, sizeof(*imr));
	iml->next = inet->mc_list;
	iml->sflist = NULL;
	iml->sfmode = MCAST_EXCLUDE;
	inet->mc_list = iml;
	ip_mc_inc_group(in_dev, addr);
	err = 0;
done:
	rtnl_unlock();
	return err;
}

static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
			   struct in_device *in_dev)
{
	int err;

	if (iml->sflist == NULL) {
		/* any-source empty exclude case */
		return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
			iml->sfmode, 0, NULL, 0);
	}
	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
			iml->sfmode, iml->sflist->sl_count,
			iml->sflist->sl_addr, 0);
	sock_kfree_s(sk, iml->sflist, IP_SFLSIZE(iml->sflist->sl_max));
	iml->sflist = NULL;
	return err;
}

/*
 *	Ask a socket to leave a group.
 */

int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
{
	struct inet_sock *inet = inet_sk(sk);
	struct ip_mc_socklist *iml, **imlp;
	struct in_device *in_dev;
	__be32 group = imr->imr_multiaddr.s_addr;
	u32 ifindex;
	int ret = -EADDRNOTAVAIL;

	rtnl_lock();
	in_dev = ip_mc_find_dev(imr);
	ifindex = imr->imr_ifindex;
	for (imlp = &inet->mc_list; (iml = *imlp) != NULL; imlp = &iml->next) {
		if (iml->multi.imr_multiaddr.s_addr != group)
			continue;
		if (ifindex) {
			if (iml->multi.imr_ifindex != ifindex)
				continue;
		} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
				iml->multi.imr_address.s_addr)
			continue;

		(void) ip_mc_leave_src(sk, iml, in_dev);

		*imlp = iml->next;

		if (in_dev)
			ip_mc_dec_group(in_dev, group);
		rtnl_unlock();
		sock_kfree_s(sk, iml, sizeof(*iml));
		return 0;
	}
	if (!in_dev)
		ret = -ENODEV;
	rtnl_unlock();
	return ret;
}

int ip_mc_source(int add, int omode, struct sock *sk, struct
	ip_mreq_source *mreqs, int ifindex)
{
	int err;
	struct ip_mreqn imr;
	__be32 addr = mreqs->imr_multiaddr;
	struct ip_mc_socklist *pmc;
	struct in_device *in_dev = NULL;
	struct inet_sock *inet = inet_sk(sk);
	struct ip_sf_socklist *psl;
	int leavegroup = 0;
	int i, j, rv;

	if (!MULTICAST(addr))
		return -EINVAL;

	rtnl_lock();

	imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
	imr.imr_address.s_addr = mreqs->imr_interface;
	imr.imr_ifindex = ifindex;
	in_dev = ip_mc_find_dev(&imr);

	if (!in_dev) {
		err = -ENODEV;
		goto done;
	}
	err = -EADDRNOTAVAIL;

	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
		if (pmc->multi.imr_multiaddr.s_addr == imr.imr_multiaddr.s_addr
		    && pmc->multi.imr_ifindex == imr.imr_ifindex)
			break;
	}
	if (!pmc) {		/* must have a prior join */
		err = -EINVAL;
		goto done;
	}
	/* if a source filter was set, must be the same mode as before */
	if (pmc->sflist) {
		if (pmc->sfmode != omode) {
			err = -EINVAL;
			goto done;
		}
	} else if (pmc->sfmode != omode) {
		/* allow mode switches for empty-set filters */
		ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
			NULL, 0);
		pmc->sfmode = omode;
	}

	psl = pmc->sflist;
	if (!add) {
		if (!psl)
			goto done;	/* err = -EADDRNOTAVAIL */
		rv = !0;
		for (i=0; i<psl->sl_count; i++) {
			rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
				sizeof(__be32));
			if (rv == 0)
				break;
		}
		if (rv)		/* source not found */
			goto done;	/* err = -EADDRNOTAVAIL */

		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
			leavegroup = 1;
			goto done;
		}

		/* update the interface filter */
		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
			&mreqs->imr_sourceaddr, 1);

		for (j=i+1; j<psl->sl_count; j++)
			psl->sl_addr[j-1] = psl->sl_addr[j];
		psl->sl_count--;
		err = 0;
		goto done;
	}
	/* else, add a new source to the filter */

	if (psl && psl->sl_count >= sysctl_igmp_max_msf) {
		err = -ENOBUFS;
		goto done;
	}
	if (!psl || psl->sl_count == psl->sl_max) {
		struct ip_sf_socklist *newpsl;
		int count = IP_SFBLOCK;

		if (psl)
			count += psl->sl_max;
		newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
		if (!newpsl) {
			err = -ENOBUFS;
			goto done;
		}
		newpsl->sl_max = count;
		newpsl->sl_count = count - IP_SFBLOCK;
		if (psl) {
			for (i=0; i<psl->sl_count; i++)
				newpsl->sl_addr[i] = psl->sl_addr[i];
			sock_kfree_s(sk, psl, IP_SFLSIZE(psl->sl_max));
		}
		pmc->sflist = psl = newpsl;
	}
	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
	for (i=0; i<psl->sl_count; i++) {
		rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
			sizeof(__be32));
		if (rv == 0)
			break;
	}
	if (rv == 0)		/* address already there is an error */
		goto done;
	for (j=psl->sl_count-1; j>=i; j--)
		psl->sl_addr[j+1] = psl->sl_addr[j];
	psl->sl_addr[i] = mreqs->imr_sourceaddr;
	psl->sl_count++;
	err = 0;
	/* update the interface list */
	ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
		&mreqs->imr_sourceaddr, 1);
done:
	rtnl_unlock();
	if (leavegroup)
		return ip_mc_leave_group(sk, &imr);
	return err;
}

int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
{
	int err = 0;
	struct ip_mreqn	imr;
	__be32 addr = msf->imsf_multiaddr;
	struct ip_mc_socklist *pmc;
	struct in_device *in_dev;
	struct inet_sock *inet = inet_sk(sk);
	struct ip_sf_socklist *newpsl, *psl;
	int leavegroup = 0;

	if (!MULTICAST(addr))
		return -EINVAL;
	if (msf->imsf_fmode != MCAST_INCLUDE &&
	    msf->imsf_fmode != MCAST_EXCLUDE)
		return -EINVAL;

	rtnl_lock();

	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
	imr.imr_address.s_addr = msf->imsf_interface;
	imr.imr_ifindex = ifindex;
	in_dev = ip_mc_find_dev(&imr);

	if (!in_dev) {
		err = -ENODEV;
		goto done;
	}

	/* special case - (INCLUDE, empty) == LEAVE_GROUP */
	if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
		leavegroup = 1;
		goto done;
	}

	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
		    pmc->multi.imr_ifindex == imr.imr_ifindex)
			break;
	}
	if (!pmc) {		/* must have a prior join */
		err = -EINVAL;
		goto done;
	}
	if (msf->imsf_numsrc) {
		newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
							   GFP_KERNEL);
		if (!newpsl) {
			err = -ENOBUFS;
			goto done;
		}
		newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
		memcpy(newpsl->sl_addr, msf->imsf_slist,
			msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
		err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
			msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
		if (err) {
			sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
			goto done;
		}
	} else {
		newpsl = NULL;
		(void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
				     msf->imsf_fmode, 0, NULL, 0);
	}
	psl = pmc->sflist;
	if (psl) {
		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
			psl->sl_count, psl->sl_addr, 0);
		sock_kfree_s(sk, psl, IP_SFLSIZE(psl->sl_max));
	} else
		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
			0, NULL, 0);
	pmc->sflist = newpsl;
	pmc->sfmode = msf->imsf_fmode;
	err = 0;
done:
	rtnl_unlock();
	if (leavegroup)
		err = ip_mc_leave_group(sk, &imr);
	return err;
}

int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
	struct ip_msfilter __user *optval, int __user *optlen)
{
	int err, len, count, copycount;
	struct ip_mreqn	imr;
	__be32 addr = msf->imsf_multiaddr;
	struct ip_mc_socklist *pmc;
	struct in_device *in_dev;
	struct inet_sock *inet = inet_sk(sk);