Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1184 insertions, 0 deletions

diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
new file mode 100644
index 000000000..fc82617b6
--- /dev/null
+++ b/net/sctp/ipv6.c
@@ -0,0 +1,1184 @@
+/* SCTP kernel implementation
+ * (C) Copyright IBM Corp. 2002, 2004
+ * Copyright (c) 2001 Nokia, Inc.
+ * Copyright (c) 2001 La Monte H.P. Yarroll
+ * Copyright (c) 2002-2003 Intel Corp.
+ *
+ * This file is part of the SCTP kernel implementation
+ *
+ * SCTP over IPv6.
+ *
+ * This SCTP implementation is free software;
+ * you can redistribute it and/or modify it under the terms of
+ * the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This SCTP implementation is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ *		   ************************
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU CC; see the file COPYING.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Please send any bug reports or fixes you make to the
+ * email address(es):
+ *    lksctp developers <linux-sctp@vger.kernel.org>
+ *
+ * Written or modified by:
+ *    Le Yanqun		    <yanqun.le@nokia.com>
+ *    Hui Huang		    <hui.huang@nokia.com>
+ *    La Monte H.P. Yarroll <piggy@acm.org>
+ *    Sridhar Samudrala	    <sri@us.ibm.com>
+ *    Jon Grimm		    <jgrimm@us.ibm.com>
+ *    Ardelle Fan	    <ardelle.fan@intel.com>
+ *
+ * Based on:
+ *	linux/net/ipv6/tcp_ipv6.c
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/netdevice.h>
+#include <linux/init.h>
+#include <linux/ipsec.h>
+#include <linux/slab.h>
+
+#include <linux/ipv6.h>
+#include <linux/icmpv6.h>
+#include <linux/random.h>
+#include <linux/seq_file.h>
+
+#include <net/protocol.h>
+#include <net/ndisc.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <net/transp_v6.h>
+#include <net/addrconf.h>
+#include <net/ip6_route.h>
+#include <net/inet_common.h>
+#include <net/inet_ecn.h>
+#include <net/sctp/sctp.h>
+
+#include <linux/uaccess.h>
+
+static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
+					 union sctp_addr *s2);
+static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
+			      __be16 port);
+static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
+			    const union sctp_addr *addr2);
+
+/* Event handler for inet6 address addition/deletion events.
+ * The sctp_local_addr_list needs to be protocted by a spin lock since
+ * multiple notifiers (say IPv4 and IPv6) may be running at the same
+ * time and thus corrupt the list.
+ * The reader side is protected with RCU.
+ */
+static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
+				void *ptr)
+{
+	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
+	struct sctp_sockaddr_entry *addr = NULL;
+	struct sctp_sockaddr_entry *temp;
+	struct net *net = dev_net(ifa->idev->dev);
+	int found = 0;
+
+	switch (ev) {
+	case NETDEV_UP:
+		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
+		if (addr) {
+			addr->a.v6.sin6_family = AF_INET6;
+			addr->a.v6.sin6_addr = ifa->addr;
+			addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
+			addr->valid = 1;
+			spin_lock_bh(&net->sctp.local_addr_lock);
+			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
+			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
+			spin_unlock_bh(&net->sctp.local_addr_lock);
+		}
+		break;
+	case NETDEV_DOWN:
+		spin_lock_bh(&net->sctp.local_addr_lock);
+		list_for_each_entry_safe(addr, temp,
+					&net->sctp.local_addr_list, list) {
+			if (addr->a.sa.sa_family == AF_INET6 &&
+					ipv6_addr_equal(&addr->a.v6.sin6_addr,
+						&ifa->addr)) {
+				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
+				found = 1;
+				addr->valid = 0;
+				list_del_rcu(&addr->list);
+				break;
+			}
+		}
+		spin_unlock_bh(&net->sctp.local_addr_lock);
+		if (found)
+			kfree_rcu(addr, rcu);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block sctp_inet6addr_notifier = {
+	.notifier_call = sctp_inet6addr_event,
+};
+
+/* ICMP error handler. */
+static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+			u8 type, u8 code, int offset, __be32 info)
+{
+	struct inet6_dev *idev;
+	struct sock *sk;
+	struct sctp_association *asoc;
+	struct sctp_transport *transport;
+	struct ipv6_pinfo *np;
+	__u16 saveip, savesctp;
+	int err;
+	struct net *net = dev_net(skb->dev);
+
+	idev = in6_dev_get(skb->dev);
+
+	/* Fix up skb to look at the embedded net header. */
+	saveip	 = skb->network_header;
+	savesctp = skb->transport_header;
+	skb_reset_network_header(skb);
+	skb_set_transport_header(skb, offset);
+	sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
+	/* Put back, the original pointers. */
+	skb->network_header   = saveip;
+	skb->transport_header = savesctp;
+	if (!sk) {
+		__ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
+		goto out;
+	}
+
+	/* Warning:  The sock lock is held.  Remember to call
+	 * sctp_err_finish!
+	 */
+
+	switch (type) {
+	case ICMPV6_PKT_TOOBIG:
+		if (ip6_sk_accept_pmtu(sk))
+			sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
+		goto out_unlock;
+	case ICMPV6_PARAMPROB:
+		if (ICMPV6_UNK_NEXTHDR == code) {
+			sctp_icmp_proto_unreachable(sk, asoc, transport);
+			goto out_unlock;
+		}
+		break;
+	case NDISC_REDIRECT:
+		sctp_icmp_redirect(sk, transport, skb);
+		goto out_unlock;
+	default:
+		break;
+	}
+
+	np = inet6_sk(sk);
+	icmpv6_err_convert(type, code, &err);
+	if (!sock_owned_by_user(sk) && np->recverr) {
+		sk->sk_err = err;
+		sk->sk_error_report(sk);
+	} else {  /* Only an error on timeout */
+		sk->sk_err_soft = err;
+	}
+
+out_unlock:
+	sctp_err_finish(sk, transport);
+out:
+	if (likely(idev != NULL))
+		in6_dev_put(idev);
+}
+
+static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
+{
+	struct sock *sk = skb->sk;
+	struct ipv6_pinfo *np = inet6_sk(sk);
+	struct flowi6 *fl6 = &transport->fl.u.ip6;
+	__u8 tclass = np->tclass;
+	int res;
+
+	pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
+		 skb->len, &fl6->saddr, &fl6->daddr);
+
+	if (transport->dscp & SCTP_DSCP_SET_MASK)
+		tclass = transport->dscp & SCTP_DSCP_VAL_MASK;
+
+	if (INET_ECN_is_capable(tclass))
+		IP6_ECN_flow_xmit(sk, fl6->flowlabel);
+
+	if (!(transport->param_flags & SPP_PMTUD_ENABLE))
+		skb->ignore_df = 1;
+
+	SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
+
+	rcu_read_lock();
+	res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
+		       tclass);
+	rcu_read_unlock();
+	return res;
+}
+
+/* Returns the dst cache entry for the given source and destination ip
+ * addresses.
+ */
+static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
+			    struct flowi *fl, struct sock *sk)
+{
+	struct sctp_association *asoc = t->asoc;
+	struct dst_entry *dst = NULL;
+	struct flowi _fl;
+	struct flowi6 *fl6 = &_fl.u.ip6;
+	struct sctp_bind_addr *bp;
+	struct ipv6_pinfo *np = inet6_sk(sk);
+	struct sctp_sockaddr_entry *laddr;
+	union sctp_addr *daddr = &t->ipaddr;
+	union sctp_addr dst_saddr;
+	struct in6_addr *final_p, final;
+	enum sctp_scope scope;
+	__u8 matchlen = 0;
+
+	memset(&_fl, 0, sizeof(_fl));
+	fl6->daddr = daddr->v6.sin6_addr;
+	fl6->fl6_dport = daddr->v6.sin6_port;
+	fl6->flowi6_proto = IPPROTO_SCTP;
+	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
+		fl6->flowi6_oif = daddr->v6.sin6_scope_id;
+	else if (asoc)
+		fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
+	if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
+		fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
+
+	if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
+		struct ip6_flowlabel *flowlabel;
+
+		flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
+		if (!flowlabel)
+			goto out;
+		fl6_sock_release(flowlabel);
+	}
+
+	pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
+
+	if (asoc)
+		fl6->fl6_sport = htons(asoc->base.bind_addr.port);
+
+	if (saddr) {
+		fl6->saddr = saddr->v6.sin6_addr;
+		if (!fl6->fl6_sport)
+			fl6->fl6_sport = saddr->v6.sin6_port;
+
+		pr_debug("src=%pI6 - ", &fl6->saddr);
+	}
+
+	rcu_read_lock();
+	final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
+	rcu_read_unlock();
+
+	dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
+	if (!asoc || saddr) {
+		t->dst = dst;
+		memcpy(fl, &_fl, sizeof(_fl));
+		goto out;
+	}
+
+	bp = &asoc->base.bind_addr;
+	scope = sctp_scope(daddr);
+	/* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
+	 * to see if we can use it.
+	 */
+	if (!IS_ERR(dst)) {
+		/* Walk through the bind address list and look for a bind
+		 * address that matches the source address of the returned dst.
+		 */
+		sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
+		rcu_read_lock();
+		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+			if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
+			    (laddr->state != SCTP_ADDR_SRC &&
+			     !asoc->src_out_of_asoc_ok))
+				continue;
+
+			/* Do not compare against v4 addrs */
+			if ((laddr->a.sa.sa_family == AF_INET6) &&
+			    (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
+				rcu_read_unlock();
+				t->dst = dst;
+				memcpy(fl, &_fl, sizeof(_fl));
+				goto out;
+			}
+		}
+		rcu_read_unlock();
+		/* None of the bound addresses match the source address of the
+		 * dst. So release it.
+		 */
+		dst_release(dst);
+		dst = NULL;
+	}
+
+	/* Walk through the bind address list and try to get the
+	 * best source address for a given destination.
+	 */
+	rcu_read_lock();
+	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+		struct dst_entry *bdst;
+		__u8 bmatchlen;
+
+		if (!laddr->valid ||
+		    laddr->state != SCTP_ADDR_SRC ||
+		    laddr->a.sa.sa_family != AF_INET6 ||
+		    scope > sctp_scope(&laddr->a))
+			continue;
+
+		fl6->saddr = laddr->a.v6.sin6_addr;
+		fl6->fl6_sport = laddr->a.v6.sin6_port;
+		final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
+		bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
+
+		if (IS_ERR(bdst))
+			continue;
+
+		if (ipv6_chk_addr(dev_net(bdst->dev),
+				  &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
+			if (!IS_ERR_OR_NULL(dst))
+				dst_release(dst);
+			dst = bdst;
+			t->dst = dst;
+			memcpy(fl, &_fl, sizeof(_fl));
+			break;
+		}
+
+		bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
+		if (matchlen > bmatchlen) {
+			dst_release(bdst);
+			continue;
+		}
+
+		if (!IS_ERR_OR_NULL(dst))
+			dst_release(dst);
+		dst = bdst;
+		matchlen = bmatchlen;
+		t->dst = dst;
+		memcpy(fl, &_fl, sizeof(_fl));
+	}
+	rcu_read_unlock();
+
+out:
+	if (!IS_ERR_OR_NULL(dst)) {
+		struct rt6_info *rt;
+
+		rt = (struct rt6_info *)dst;
+		t->dst_cookie = rt6_get_cookie(rt);
+		pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
+			 &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
+			 &fl->u.ip6.saddr);
+	} else {
+		t->dst = NULL;
+		pr_debug("no route\n");
+	}
+}
+
+/* Returns the number of consecutive initial bits that match in the 2 ipv6
+ * addresses.
+ */
+static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
+					 union sctp_addr *s2)
+{
+	return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
+}
+
+/* Fills in the source address(saddr) based on the destination address(daddr)
+ * and asoc's bind address list.
+ */
+static void sctp_v6_get_saddr(struct sctp_sock *sk,
+			      struct sctp_transport *t,
+			      struct flowi *fl)
+{
+	struct flowi6 *fl6 = &fl->u.ip6;
+	union sctp_addr *saddr = &t->saddr;
+
+	pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
+
+	if (t->dst) {
+		saddr->v6.sin6_family = AF_INET6;
+		saddr->v6.sin6_addr = fl6->saddr;
+	}
+}
+
+/* Make a copy of all potential local addresses. */
+static void sctp_v6_copy_addrlist(struct list_head *addrlist,
+				  struct net_device *dev)
+{
+	struct inet6_dev *in6_dev;
+	struct inet6_ifaddr *ifp;
+	struct sctp_sockaddr_entry *addr;
+
+	rcu_read_lock();
+	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
+		rcu_read_unlock();
+		return;
+	}
+
+	read_lock_bh(&in6_dev->lock);
+	list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
+		/* Add the address to the local list.  */
+		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
+		if (addr) {
+			addr->a.v6.sin6_family = AF_INET6;
+			addr->a.v6.sin6_addr = ifp->addr;
+			addr->a.v6.sin6_scope_id = dev->ifindex;
+			addr->valid = 1;
+			INIT_LIST_HEAD(&addr->list);
+			list_add_tail(&addr->list, addrlist);
+		}
+	}
+
+	read_unlock_bh(&in6_dev->lock);
+	rcu_read_unlock();
+}
+
+/* Copy over any ip options */
+static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
+{
+	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
+	struct ipv6_txoptions *opt;
+
+	newnp = inet6_sk(newsk);
+
+	rcu_read_lock();
+	opt = rcu_dereference(np->opt);
+	if (opt) {
+		opt = ipv6_dup_options(newsk, opt);
+		if (!opt)
+			pr_err("%s: Failed to copy ip options\n", __func__);
+	}
+	RCU_INIT_POINTER(newnp->opt, opt);
+	rcu_read_unlock();
+}
+
+/* Account for the IP options */
+static int sctp_v6_ip_options_len(struct sock *sk)
+{
+	struct ipv6_pinfo *np = inet6_sk(sk);
+	struct ipv6_txoptions *opt;
+	int len = 0;
+
+	rcu_read_lock();
+	opt = rcu_dereference(np->opt);
+	if (opt)
+		len = opt->opt_flen + opt->opt_nflen;
+
+	rcu_read_unlock();
+	return len;
+}
+
+/* Initialize a sockaddr_storage from in incoming skb. */
+static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
+			     int is_saddr)
+{
+	/* Always called on head skb, so this is safe */
+	struct sctphdr *sh = sctp_hdr(skb);
+	struct sockaddr_in6 *sa = &addr->v6;
+
+	addr->v6.sin6_family = AF_INET6;
+	addr->v6.sin6_flowinfo = 0; /* FIXME */
+	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
+
+	if (is_saddr) {
+		sa->sin6_port = sh->source;
+		sa->sin6_addr = ipv6_hdr(skb)->saddr;
+	} else {
+		sa->sin6_port = sh->dest;
+		sa->sin6_addr = ipv6_hdr(skb)->daddr;
+	}
+}
+
+/* Initialize an sctp_addr from a socket. */
+static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
+{
+	addr->v6.sin6_family = AF_INET6;
+	addr->v6.sin6_port = 0;
+	addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
+}
+
+/* Initialize sk->sk_rcv_saddr from sctp_addr. */
+static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
+{
+	if (addr->sa.sa_family == AF_INET) {
+		sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
+		sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
+		sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
+		sk->sk_v6_rcv_saddr.s6_addr32[3] =
+			addr->v4.sin_addr.s_addr;
+	} else {
+		sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
+	}
+}
+
+/* Initialize sk->sk_daddr from sctp_addr. */
+static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
+{
+	if (addr->sa.sa_family == AF_INET) {
+		sk->sk_v6_daddr.s6_addr32[0] = 0;
+		sk->sk_v6_daddr.s6_addr32[1] = 0;
+		sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
+		sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
+	} else {
+		sk->sk_v6_daddr = addr->v6.sin6_addr;
+	}
+}
+
+/* Initialize a sctp_addr from an address parameter. */
+static bool sctp_v6_from_addr_param(union sctp_addr *addr,
+				    union sctp_addr_param *param,
+				    __be16 port, int iif)
+{
+	if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param))
+		return false;
+
+	addr->v6.sin6_family = AF_INET6;
+	addr->v6.sin6_port = port;
+	addr->v6.sin6_flowinfo = 0; /* BUG */
+	addr->v6.sin6_addr = param->v6.addr;
+	addr->v6.sin6_scope_id = iif;
+
+	return true;
+}
+
+/* Initialize an address parameter from a sctp_addr and return the length
+ * of the address parameter.
+ */
+static int sctp_v6_to_addr_param(const union sctp_addr *addr,
+				 union sctp_addr_param *param)
+{
+	int length = sizeof(struct sctp_ipv6addr_param);
+
+	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
+	param->v6.param_hdr.length = htons(length);
+	param->v6.addr = addr->v6.sin6_addr;
+
+	return length;
+}
+
+/* Initialize a sctp_addr from struct in6_addr. */
+static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
+			      __be16 port)
+{
+	addr->sa.sa_family = AF_INET6;
+	addr->v6.sin6_port = port;
+	addr->v6.sin6_flowinfo = 0;
+	addr->v6.sin6_addr = *saddr;
+	addr->v6.sin6_scope_id = 0;
+}
+
+static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
+			      const union sctp_addr *addr2)
+{
+	if (addr1->sa.sa_family != addr2->sa.sa_family) {
+		if (addr1->sa.sa_family == AF_INET &&
+		    addr2->sa.sa_family == AF_INET6 &&
+		    ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
+		    addr2->v6.sin6_addr.s6_addr32[3] ==
+		    addr1->v4.sin_addr.s_addr)
+			return 1;
+
+		if (addr2->sa.sa_family == AF_INET &&
+		    addr1->sa.sa_family == AF_INET6 &&
+		    ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
+		    addr1->v6.sin6_addr.s6_addr32[3] ==
+		    addr2->v4.sin_addr.s_addr)
+			return 1;
+
+		return 0;
+	}
+
+	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
+		return 0;
+
+	/* If this is a linklocal address, compare the scope_id. */
+	if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
+	    addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
+	    addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
+		return 0;
+
+	return 1;
+}
+
+/* Compare addresses exactly.
+ * v4-mapped-v6 is also in consideration.
+ */
+static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
+			    const union sctp_addr *addr2)
+{
+	return __sctp_v6_cmp_addr(addr1, addr2) &&
+	       addr1->v6.sin6_port == addr2->v6.sin6_port;
+}
+
+/* Initialize addr struct to INADDR_ANY. */
+static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
+{
+	memset(addr, 0x00, sizeof(union sctp_addr));
+	addr->v6.sin6_family = AF_INET6;
+	addr->v6.sin6_port = port;
+}
+
+/* Is this a wildcard address? */
+static int sctp_v6_is_any(const union sctp_addr *addr)
+{
+	return ipv6_addr_any(&addr->v6.sin6_addr);
+}
+
+/* Should this be available for binding?   */
+static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
+{
+	int type;
+	struct net *net = sock_net(&sp->inet.sk);
+	const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
+
+	type = ipv6_addr_type(in6);
+	if (IPV6_ADDR_ANY == type)
+		return 1;
+	if (type == IPV6_ADDR_MAPPED) {
+		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
+			return 0;
+		sctp_v6_map_v4(addr);
+		return sctp_get_af_specific(AF_INET)->available(addr, sp);
+	}
+	if (!(type & IPV6_ADDR_UNICAST))
+		return 0;
+
+	return ipv6_can_nonlocal_bind(net, &sp->inet) ||
+	       ipv6_chk_addr(net, in6, NULL, 0);
+}
+
+/* This function checks if the address is a valid address to be used for
+ * SCTP.
+ *
+ * Output:
+ * Return 0 - If the address is a non-unicast or an illegal address.
+ * Return 1 - If the address is a unicast.
+ */
+static int sctp_v6_addr_valid(union sctp_addr *addr,
+			      struct sctp_sock *sp,
+			      const struct sk_buff *skb)
+{
+	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
+
+	/* Support v4-mapped-v6 address. */
+	if (ret == IPV6_ADDR_MAPPED) {
+		/* Note: This routine is used in input, so v4-mapped-v6
+		 * are disallowed here when there is no sctp_sock.
+		 */
+		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
+			return 0;
+		sctp_v6_map_v4(addr);
+		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
+	}
+
+	/* Is this a non-unicast address */
+	if (!(ret & IPV6_ADDR_UNICAST))
+		return 0;
+
+	return 1;
+}
+
+/* What is the scope of 'addr'?  */
+static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
+{
+	enum sctp_scope retval;
+	int v6scope;
+
+	/* The IPv6 scope is really a set of bit fields.
+	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
+	 */
+
+	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
+	switch (v6scope) {
+	case IFA_HOST:
+		retval = SCTP_SCOPE_LOOPBACK;
+		break;
+	case IFA_LINK:
+		retval = SCTP_SCOPE_LINK;
+		break;
+	case IFA_SITE:
+		retval = SCTP_SCOPE_PRIVATE;
+		break;
+	default:
+		retval = SCTP_SCOPE_GLOBAL;
+		break;
+	}
+
+	return retval;
+}
+
+/* Create and initialize a new sk for the socket to be returned by accept(). */
+static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
+					     struct sctp_association *asoc,
+					     bool kern)
+{
+	struct sock *newsk;
+	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
+	struct sctp6_sock *newsctp6sk;
+
+	newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
+	if (!newsk)
+		goto out;
+
+	sock_init_data(NULL, newsk);
+
+	sctp_copy_sock(newsk, sk, asoc);
+	sock_reset_flag(sk, SOCK_ZAPPED);
+
+	newsctp6sk = (struct sctp6_sock *)newsk;
+	inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
+
+	sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
+
+	newnp = inet6_sk(newsk);
+
+	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
+	newnp->ipv6_mc_list = NULL;
+	newnp->ipv6_ac_list = NULL;
+	newnp->ipv6_fl_list = NULL;
+
+	sctp_v6_copy_ip_options(sk, newsk);
+
+	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
+	 * and getpeername().
+	 */
+	sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
+
+	newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
+
+	sk_refcnt_debug_inc(newsk);
+
+	if (newsk->sk_prot->init(newsk)) {
+		sk_common_release(newsk);
+		newsk = NULL;
+	}
+
+out:
+	return newsk;
+}
+
+/* Format a sockaddr for return to user space. This makes sure the return is
+ * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
+ */
+static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
+{
+	if (sp->v4mapped) {
+		if (addr->sa.sa_family == AF_INET)
+			sctp_v4_map_v6(addr);
+	} else {
+		if (addr->sa.sa_family == AF_INET6 &&
+		    ipv6_addr_v4mapped(&addr->v6.sin6_addr))
+			sctp_v6_map_v4(addr);
+	}
+
+	if (addr->sa.sa_family == AF_INET) {
+		memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
+		return sizeof(struct sockaddr_in);
+	}
+	return sizeof(struct sockaddr_in6);
+}
+
+/* Where did this skb come from?  */
+static int sctp_v6_skb_iif(const struct sk_buff *skb)
+{
+	return IP6CB(skb)->iif;
+}
+
+/* Was this packet marked by Explicit Congestion Notification? */
+static int sctp_v6_is_ce(const struct sk_buff *skb)
+{
+	return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
+}
+
+/* Dump the v6 addr to the seq file. */
+static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
+{
+	seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
+}
+
+static void sctp_v6_ecn_capable(struct sock *sk)
+{
+	inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
+}
+
+/* Initialize a PF_INET msgname from a ulpevent. */
+static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
+				     char *msgname, int *addrlen)
+{
+	union sctp_addr *addr;
+	struct sctp_association *asoc;
+	union sctp_addr *paddr;
+
+	if (!msgname)
+		return;
+
+	addr = (union sctp_addr *)msgname;
+	asoc = event->asoc;
+	paddr = &asoc->peer.primary_addr;
+
+	if (paddr->sa.sa_family == AF_INET) {
+		addr->v4.sin_family = AF_INET;
+		addr->v4.sin_port = htons(asoc->peer.port);
+		addr->v4.sin_addr = paddr->v4.sin_addr;
+	} else {
+		addr->v6.sin6_family = AF_INET6;
+		addr->v6.sin6_flowinfo = 0;
+		if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
+			addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
+		else
+			addr->v6.sin6_scope_id = 0;
+		addr->v6.sin6_port = htons(asoc->peer.port);
+		addr->v6.sin6_addr = paddr->v6.sin6_addr;
+	}
+
+	*addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
+}
+
+/* Initialize a msg_name from an inbound skb. */
+static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
+				   int *addr_len)
+{
+	union sctp_addr *addr;
+	struct sctphdr *sh;
+
+	if (!msgname)
+		return;
+
+	addr = (union sctp_addr *)msgname;
+	sh = sctp_hdr(skb);
+
+	if (ip_hdr(skb)->version == 4) {
+		addr->v4.sin_family = AF_INET;
+		addr->v4.sin_port = sh->source;
+		addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
+	} else {
+		addr->v6.sin6_family = AF_INET6;
+		addr->v6.sin6_flowinfo = 0;
+		addr->v6.sin6_port = sh->source;
+		addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
+		if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
+			addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
+		else
+			addr->v6.sin6_scope_id = 0;
+	}
+
+	*addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
+}
+
+/* Do we support this AF? */
+static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
+{
+	switch (family) {
+	case AF_INET6:
+		return 1;
+	/* v4-mapped-v6 addresses */
+	case AF_INET:
+		if (!__ipv6_only_sock(sctp_opt2sk(sp)))
+			return 1;
+		/* fallthru */
+	default:
+		return 0;
+	}
+}
+
+/* Address matching with wildcards allowed.  This extra level
+ * of indirection lets us choose whether a PF_INET6 should
+ * disallow any v4 addresses if we so choose.
+ */
+static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
+			       const union sctp_addr *addr2,
+			       struct sctp_sock *opt)
+{
+	struct sock *sk = sctp_opt2sk(opt);
+	struct sctp_af *af1, *af2;
+
+	af1 = sctp_get_af_specific(addr1->sa.sa_family);
+	af2 = sctp_get_af_specific(addr2->sa.sa_family);
+
+	if (!af1 || !af2)
+		return 0;
+
+	/* If the socket is IPv6 only, v4 addrs will not match */
+	if (__ipv6_only_sock(sk) && af1 != af2)
+		return 0;
+
+	/* Today, wildcard AF_INET/AF_INET6. */
+	if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
+		return 1;
+
+	if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
+		return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
+
+	return __sctp_v6_cmp_addr(addr1, addr2);
+}
+
+/* Verify that the provided sockaddr looks bindable.   Common verification,
+ * has already been taken care of.
+ */
+static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
+{
+	struct sctp_af *af;
+
+	/* ASSERT: address family has already been verified. */
+	if (addr->sa.sa_family != AF_INET6)
+		af = sctp_get_af_specific(addr->sa.sa_family);
+	else {
+		int type = ipv6_addr_type(&addr->v6.sin6_addr);
+		struct net_device *dev;
+
+		if (type & IPV6_ADDR_LINKLOCAL) {
+			struct net *net;
+			if (!addr->v6.sin6_scope_id)
+				return 0;
+			net = sock_net(&opt->inet.sk);
+			rcu_read_lock();
+			dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
+			if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) ||
+				      ipv6_chk_addr(net, &addr->v6.sin6_addr,
+						    dev, 0))) {
+				rcu_read_unlock();
+				return 0;
+			}
+			rcu_read_unlock();
+		}
+
+		af = opt->pf->af;
+	}
+	return af->available(addr, opt);
+}
+
+/* Verify that the provided sockaddr looks sendable.   Common verification,
+ * has already been taken care of.
+ */
+static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
+{
+	struct sctp_af *af = NULL;
+
+	/* ASSERT: address family has already been verified. */
+	if (addr->sa.sa_family != AF_INET6)
+		af = sctp_get_af_specific(addr->sa.sa_family);
+	else {
+		int type = ipv6_addr_type(&addr->v6.sin6_addr);
+		struct net_device *dev;
+
+		if (type & IPV6_ADDR_LINKLOCAL) {
+			if (!addr->v6.sin6_scope_id)
+				return 0;
+			rcu_read_lock();
+			dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
+						   addr->v6.sin6_scope_id);
+			rcu_read_unlock();
+			if (!dev)
+				return 0;
+		}
+		af = opt->pf->af;
+	}
+
+	return af != NULL;
+}
+
+/* Fill in Supported Address Type information for INIT and INIT-ACK
+ * chunks.   Note: In the future, we may want to look at sock options
+ * to determine whether a PF_INET6 socket really wants to have IPV4
+ * addresses.
+ * Returns number of addresses supported.
+ */
+static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
+				      __be16 *types)
+{
+	types[0] = SCTP_PARAM_IPV6_ADDRESS;
+	if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
+		types[1] = SCTP_PARAM_IPV4_ADDRESS;
+		return 2;
+	}
+	return 1;
+}
+
+/* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
+static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
+			int peer)
+{
+	int rc;
+
+	rc = inet6_getname(sock, uaddr, peer);
+
+	if (rc < 0)
+		return rc;
+
+	rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
+					  (union sctp_addr *)uaddr);
+
+	return rc;
+}
+
+static const struct proto_ops inet6_seqpacket_ops = {
+	.family		   = PF_INET6,
+	.owner		   = THIS_MODULE,
+	.release	   = inet6_release,
+	.bind		   = inet6_bind,
+	.connect	   = sctp_inet_connect,
+	.socketpair	   = sock_no_socketpair,
+	.accept		   = inet_accept,
+	.getname	   = sctp_getname,
+	.poll		   = sctp_poll,
+	.ioctl		   = inet6_ioctl,
+	.listen		   = sctp_inet_listen,
+	.shutdown	   = inet_shutdown,
+	.setsockopt	   = sock_common_setsockopt,
+	.getsockopt	   = sock_common_getsockopt,
+	.sendmsg	   = inet_sendmsg,
+	.recvmsg	   = inet_recvmsg,
+	.mmap		   = sock_no_mmap,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_sock_common_setsockopt,
+	.compat_getsockopt = compat_sock_common_getsockopt,
+#endif
+};
+
+static struct inet_protosw sctpv6_seqpacket_protosw = {
+	.type          = SOCK_SEQPACKET,
+	.protocol      = IPPROTO_SCTP,
+	.prot 	       = &sctpv6_prot,
+	.ops           = &inet6_seqpacket_ops,
+	.flags         = SCTP_PROTOSW_FLAG
+};
+static struct inet_protosw sctpv6_stream_protosw = {
+	.type          = SOCK_STREAM,
+	.protocol      = IPPROTO_SCTP,
+	.prot 	       = &sctpv6_prot,
+	.ops           = &inet6_seqpacket_ops,
+	.flags         = SCTP_PROTOSW_FLAG,
+};
+
+static int sctp6_rcv(struct sk_buff *skb)
+{
+	return sctp_rcv(skb) ? -1 : 0;
+}
+
+static const struct inet6_protocol sctpv6_protocol = {
+	.handler      = sctp6_rcv,
+	.err_handler  = sctp_v6_err,
+	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
+};
+
+static struct sctp_af sctp_af_inet6 = {
+	.sa_family	   = AF_INET6,
+	.sctp_xmit	   = sctp_v6_xmit,
+	.setsockopt	   = ipv6_setsockopt,
+	.getsockopt	   = ipv6_getsockopt,
+	.get_dst	   = sctp_v6_get_dst,
+	.get_saddr	   = sctp_v6_get_saddr,
+	.copy_addrlist	   = sctp_v6_copy_addrlist,
+	.from_skb	   = sctp_v6_from_skb,
+	.from_sk	   = sctp_v6_from_sk,
+	.from_addr_param   = sctp_v6_from_addr_param,
+	.to_addr_param	   = sctp_v6_to_addr_param,
+	.cmp_addr	   = sctp_v6_cmp_addr,
+	.scope		   = sctp_v6_scope,
+	.addr_valid	   = sctp_v6_addr_valid,
+	.inaddr_any	   = sctp_v6_inaddr_any,
+	.is_any		   = sctp_v6_is_any,
+	.available	   = sctp_v6_available,
+	.skb_iif	   = sctp_v6_skb_iif,
+	.is_ce		   = sctp_v6_is_ce,
+	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
+	.ecn_capable	   = sctp_v6_ecn_capable,
+	.net_header_len	   = sizeof(struct ipv6hdr),
+	.sockaddr_len	   = sizeof(struct sockaddr_in6),
+	.ip_options_len	   = sctp_v6_ip_options_len,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_ipv6_setsockopt,
+	.compat_getsockopt = compat_ipv6_getsockopt,
+#endif
+};
+
+static struct sctp_pf sctp_pf_inet6 = {
+	.event_msgname = sctp_inet6_event_msgname,
+	.skb_msgname   = sctp_inet6_skb_msgname,
+	.af_supported  = sctp_inet6_af_supported,
+	.cmp_addr      = sctp_inet6_cmp_addr,
+	.bind_verify   = sctp_inet6_bind_verify,
+	.send_verify   = sctp_inet6_send_verify,
+	.supported_addrs = sctp_inet6_supported_addrs,
+	.create_accept_sk = sctp_v6_create_accept_sk,
+	.addr_to_user  = sctp_v6_addr_to_user,
+	.to_sk_saddr   = sctp_v6_to_sk_saddr,
+	.to_sk_daddr   = sctp_v6_to_sk_daddr,
+	.copy_ip_options = sctp_v6_copy_ip_options,
+	.af            = &sctp_af_inet6,
+};
+
+/* Initialize IPv6 support and register with socket layer.  */
+void sctp_v6_pf_init(void)
+{
+	/* Register the SCTP specific PF_INET6 functions. */
+	sctp_register_pf(&sctp_pf_inet6, PF_INET6);
+
+	/* Register the SCTP specific AF_INET6 functions. */
+	sctp_register_af(&sctp_af_inet6);
+}
+
+void sctp_v6_pf_exit(void)
+{
+	list_del(&sctp_af_inet6.list);
+}
+
+/* Initialize IPv6 support and register with socket layer.  */
+int sctp_v6_protosw_init(void)
+{
+	int rc;
+
+	rc = proto_register(&sctpv6_prot, 1);
+	if (rc)
+		return rc;
+
+	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
+	inet6_register_protosw(&sctpv6_seqpacket_protosw);
+	inet6_register_protosw(&sctpv6_stream_protosw);
+
+	return 0;
+}
+
+void sctp_v6_protosw_exit(void)
+{
+	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
+	inet6_unregister_protosw(&sctpv6_stream_protosw);
+	proto_unregister(&sctpv6_prot);
+}
+
+
+/* Register with inet6 layer. */
+int sctp_v6_add_protocol(void)
+{
+	/* Register notifier for inet6 address additions/deletions. */
+	register_inet6addr_notifier(&sctp_inet6addr_notifier);
+
+	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
+		return -EAGAIN;
+
+	return 0;
+}
+
+/* Unregister with inet6 layer. */
+void sctp_v6_del_protocol(void)
+{
+	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
+	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
+}