Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 1208 insertions, 0 deletions

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
new file mode 100644
index 000000000..e2af7ab99
--- /dev/null
+++ b/net/ipv6/icmp.c
@@ -0,0 +1,1208 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	Internet Control Message Protocol (ICMPv6)
+ *	Linux INET6 implementation
+ *
+ *	Authors:
+ *	Pedro Roque		<roque@di.fc.ul.pt>
+ *
+ *	Based on net/ipv4/icmp.c
+ *
+ *	RFC 1885
+ */
+
+/*
+ *	Changes:
+ *
+ *	Andi Kleen		:	exception handling
+ *	Andi Kleen			add rate limits. never reply to a icmp.
+ *					add more length checks and other fixes.
+ *	yoshfuji		:	ensure to sent parameter problem for
+ *					fragments.
+ *	YOSHIFUJI Hideaki @USAGI:	added sysctl for icmp rate limit.
+ *	Randy Dunlap and
+ *	YOSHIFUJI Hideaki @USAGI:	Per-interface statistics support
+ *	Kazunori MIYAZAWA @USAGI:       change output process to use ip6_append_data
+ */
+
+#define pr_fmt(fmt) "IPv6: " fmt
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/netfilter.h>
+#include <linux/slab.h>
+
+#ifdef CONFIG_SYSCTL
+#include <linux/sysctl.h>
+#endif
+
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/icmpv6.h>
+
+#include <net/ip.h>
+#include <net/sock.h>
+
+#include <net/ipv6.h>
+#include <net/ip6_checksum.h>
+#include <net/ping.h>
+#include <net/protocol.h>
+#include <net/raw.h>
+#include <net/rawv6.h>
+#include <net/seg6.h>
+#include <net/transp_v6.h>
+#include <net/ip6_route.h>
+#include <net/addrconf.h>
+#include <net/icmp.h>
+#include <net/xfrm.h>
+#include <net/inet_common.h>
+#include <net/dsfield.h>
+#include <net/l3mdev.h>
+
+#include <linux/uaccess.h>
+
+static DEFINE_PER_CPU(struct sock *, ipv6_icmp_sk);
+
+static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+		       u8 type, u8 code, int offset, __be32 info)
+{
+	/* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
+	struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
+	struct net *net = dev_net(skb->dev);
+
+	if (type == ICMPV6_PKT_TOOBIG)
+		ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL));
+	else if (type == NDISC_REDIRECT)
+		ip6_redirect(skb, net, skb->dev->ifindex, 0,
+			     sock_net_uid(net, NULL));
+
+	if (!(type & ICMPV6_INFOMSG_MASK))
+		if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
+			ping_err(skb, offset, ntohl(info));
+
+	return 0;
+}
+
+static int icmpv6_rcv(struct sk_buff *skb);
+
+static const struct inet6_protocol icmpv6_protocol = {
+	.handler	=	icmpv6_rcv,
+	.err_handler	=	icmpv6_err,
+	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
+};
+
+/* Called with BH disabled */
+static struct sock *icmpv6_xmit_lock(struct net *net)
+{
+	struct sock *sk;
+
+	sk = this_cpu_read(ipv6_icmp_sk);
+	if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
+		/* This can happen if the output path (f.e. SIT or
+		 * ip6ip6 tunnel) signals dst_link_failure() for an
+		 * outgoing ICMP6 packet.
+		 */
+		return NULL;
+	}
+	sock_net_set(sk, net);
+	return sk;
+}
+
+static void icmpv6_xmit_unlock(struct sock *sk)
+{
+	sock_net_set(sk, &init_net);
+	spin_unlock(&sk->sk_lock.slock);
+}
+
+/*
+ * Figure out, may we reply to this packet with icmp error.
+ *
+ * We do not reply, if:
+ *	- it was icmp error message.
+ *	- it is truncated, so that it is known, that protocol is ICMPV6
+ *	  (i.e. in the middle of some exthdr)
+ *
+ *	--ANK (980726)
+ */
+
+static bool is_ineligible(const struct sk_buff *skb)
+{
+	int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
+	int len = skb->len - ptr;
+	__u8 nexthdr = ipv6_hdr(skb)->nexthdr;
+	__be16 frag_off;
+
+	if (len < 0)
+		return true;
+
+	ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
+	if (ptr < 0)
+		return false;
+	if (nexthdr == IPPROTO_ICMPV6) {
+		u8 _type, *tp;
+		tp = skb_header_pointer(skb,
+			ptr+offsetof(struct icmp6hdr, icmp6_type),
+			sizeof(_type), &_type);
+
+		/* Based on RFC 8200, Section 4.5 Fragment Header, return
+		 * false if this is a fragment packet with no icmp header info.
+		 */
+		if (!tp && frag_off != 0)
+			return false;
+		else if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
+			return true;
+	}
+	return false;
+}
+
+static bool icmpv6_mask_allow(struct net *net, int type)
+{
+	if (type > ICMPV6_MSG_MAX)
+		return true;
+
+	/* Limit if icmp type is set in ratemask. */
+	if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask))
+		return true;
+
+	return false;
+}
+
+static bool icmpv6_global_allow(struct net *net, int type)
+{
+	if (icmpv6_mask_allow(net, type))
+		return true;
+
+	if (icmp_global_allow())
+		return true;
+
+	return false;
+}
+
+/*
+ * Check the ICMP output rate limit
+ */
+static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
+			       struct flowi6 *fl6)
+{
+	struct net *net = sock_net(sk);
+	struct dst_entry *dst;
+	bool res = false;
+
+	if (icmpv6_mask_allow(net, type))
+		return true;
+
+	/*
+	 * Look up the output route.
+	 * XXX: perhaps the expire for routing entries cloned by
+	 * this lookup should be more aggressive (not longer than timeout).
+	 */
+	dst = ip6_route_output(net, sk, fl6);
+	if (dst->error) {
+		IP6_INC_STATS(net, ip6_dst_idev(dst),
+			      IPSTATS_MIB_OUTNOROUTES);
+	} else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
+		res = true;
+	} else {
+		struct rt6_info *rt = (struct rt6_info *)dst;
+		int tmo = net->ipv6.sysctl.icmpv6_time;
+		struct inet_peer *peer;
+
+		/* Give more bandwidth to wider prefixes. */
+		if (rt->rt6i_dst.plen < 128)
+			tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
+
+		peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1);
+		res = inet_peer_xrlim_allow(peer, tmo);
+		if (peer)
+			inet_putpeer(peer);
+	}
+	dst_release(dst);
+	return res;
+}
+
+static bool icmpv6_rt_has_prefsrc(struct sock *sk, u8 type,
+				  struct flowi6 *fl6)
+{
+	struct net *net = sock_net(sk);
+	struct dst_entry *dst;
+	bool res = false;
+
+	dst = ip6_route_output(net, sk, fl6);
+	if (!dst->error) {
+		struct rt6_info *rt = (struct rt6_info *)dst;
+		struct in6_addr prefsrc;
+
+		rt6_get_prefsrc(rt, &prefsrc);
+		res = !ipv6_addr_any(&prefsrc);
+	}
+	dst_release(dst);
+	return res;
+}
+
+/*
+ *	an inline helper for the "simple" if statement below
+ *	checks if parameter problem report is caused by an
+ *	unrecognized IPv6 option that has the Option Type
+ *	highest-order two bits set to 10
+ */
+
+static bool opt_unrec(struct sk_buff *skb, __u32 offset)
+{
+	u8 _optval, *op;
+
+	offset += skb_network_offset(skb);
+	op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
+	if (!op)
+		return true;
+	return (*op & 0xC0) == 0x80;
+}
+
+void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
+				struct icmp6hdr *thdr, int len)
+{
+	struct sk_buff *skb;
+	struct icmp6hdr *icmp6h;
+
+	skb = skb_peek(&sk->sk_write_queue);
+	if (!skb)
+		return;
+
+	icmp6h = icmp6_hdr(skb);
+	memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
+	icmp6h->icmp6_cksum = 0;
+
+	if (skb_queue_len(&sk->sk_write_queue) == 1) {
+		skb->csum = csum_partial(icmp6h,
+					sizeof(struct icmp6hdr), skb->csum);
+		icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
+						      &fl6->daddr,
+						      len, fl6->flowi6_proto,
+						      skb->csum);
+	} else {
+		__wsum tmp_csum = 0;
+
+		skb_queue_walk(&sk->sk_write_queue, skb) {
+			tmp_csum = csum_add(tmp_csum, skb->csum);
+		}
+
+		tmp_csum = csum_partial(icmp6h,
+					sizeof(struct icmp6hdr), tmp_csum);
+		icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
+						      &fl6->daddr,
+						      len, fl6->flowi6_proto,
+						      tmp_csum);
+	}
+	ip6_push_pending_frames(sk);
+}
+
+struct icmpv6_msg {
+	struct sk_buff	*skb;
+	int		offset;
+	uint8_t		type;
+};
+
+static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
+{
+	struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
+	struct sk_buff *org_skb = msg->skb;
+	__wsum csum;
+
+	csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
+				      to, len);
+	skb->csum = csum_block_add(skb->csum, csum, odd);
+	if (!(msg->type & ICMPV6_INFOMSG_MASK))
+		nf_ct_attach(skb, org_skb);
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_IPV6_MIP6)
+static void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt)
+{
+	struct ipv6hdr *iph = ipv6_hdr(skb);
+	struct ipv6_destopt_hao *hao;
+	struct in6_addr tmp;
+	int off;
+
+	if (opt->dsthao) {
+		off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
+		if (likely(off >= 0)) {
+			hao = (struct ipv6_destopt_hao *)
+					(skb_network_header(skb) + off);
+			tmp = iph->saddr;
+			iph->saddr = hao->addr;
+			hao->addr = tmp;
+		}
+	}
+}
+#else
+static inline void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt) {}
+#endif
+
+static struct dst_entry *icmpv6_route_lookup(struct net *net,
+					     struct sk_buff *skb,
+					     struct sock *sk,
+					     struct flowi6 *fl6)
+{
+	struct dst_entry *dst, *dst2;
+	struct flowi6 fl2;
+	int err;
+
+	err = ip6_dst_lookup(net, sk, &dst, fl6);
+	if (err)
+		return ERR_PTR(err);
+
+	/*
+	 * We won't send icmp if the destination is known
+	 * anycast.
+	 */
+	if (ipv6_anycast_destination(dst, &fl6->daddr)) {
+		net_dbg_ratelimited("icmp6_send: acast source\n");
+		dst_release(dst);
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* No need to clone since we're just using its address. */
+	dst2 = dst;
+
+	dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
+	if (!IS_ERR(dst)) {
+		if (dst != dst2)
+			return dst;
+	} else {
+		if (PTR_ERR(dst) == -EPERM)
+			dst = NULL;
+		else
+			return dst;
+	}
+
+	err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
+	if (err)
+		goto relookup_failed;
+
+	err = ip6_dst_lookup(net, sk, &dst2, &fl2);
+	if (err)
+		goto relookup_failed;
+
+	dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
+	if (!IS_ERR(dst2)) {
+		dst_release(dst);
+		dst = dst2;
+	} else {
+		err = PTR_ERR(dst2);
+		if (err == -EPERM) {
+			dst_release(dst);
+			return dst2;
+		} else
+			goto relookup_failed;
+	}
+
+relookup_failed:
+	if (dst)
+		return dst;
+	return ERR_PTR(err);
+}
+
+static struct net_device *icmp6_dev(const struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+
+	/* for local traffic to local address, skb dev is the loopback
+	 * device. Check if there is a dst attached to the skb and if so
+	 * get the real device index. Same is needed for replies to a link
+	 * local address on a device enslaved to an L3 master device
+	 */
+	if (unlikely(dev->ifindex == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {
+		const struct rt6_info *rt6 = skb_rt6_info(skb);
+
+		/* The destination could be an external IP in Ext Hdr (SRv6, RPL, etc.),
+		 * and ip6_null_entry could be set to skb if no route is found.
+		 */
+		if (rt6 && rt6->rt6i_idev)
+			dev = rt6->rt6i_idev->dev;
+	}
+
+	return dev;
+}
+
+static int icmp6_iif(const struct sk_buff *skb)
+{
+	return icmp6_dev(skb)->ifindex;
+}
+
+/*
+ *	Send an ICMP message in response to a packet in error
+ */
+void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
+		const struct in6_addr *force_saddr,
+		const struct inet6_skb_parm *parm)
+{
+	struct inet6_dev *idev = NULL;
+	struct ipv6hdr *hdr = ipv6_hdr(skb);
+	struct sock *sk;
+	struct net *net;
+	struct ipv6_pinfo *np;
+	const struct in6_addr *saddr = NULL;
+	struct dst_entry *dst;
+	struct icmp6hdr tmp_hdr;
+	struct flowi6 fl6;
+	struct icmpv6_msg msg;
+	struct ipcm6_cookie ipc6;
+	int iif = 0;
+	int addr_type = 0;
+	int len;
+	u32 mark;
+
+	if ((u8 *)hdr < skb->head ||
+	    (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
+		return;
+
+	if (!skb->dev)
+		return;
+	net = dev_net(skb->dev);
+	mark = IP6_REPLY_MARK(net, skb->mark);
+	/*
+	 *	Make sure we respect the rules
+	 *	i.e. RFC 1885 2.4(e)
+	 *	Rule (e.1) is enforced by not using icmp6_send
+	 *	in any code that processes icmp errors.
+	 */
+	addr_type = ipv6_addr_type(&hdr->daddr);
+
+	if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
+	    ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
+		saddr = &hdr->daddr;
+
+	/*
+	 *	Dest addr check
+	 */
+
+	if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
+		if (type != ICMPV6_PKT_TOOBIG &&
+		    !(type == ICMPV6_PARAMPROB &&
+		      code == ICMPV6_UNK_OPTION &&
+		      (opt_unrec(skb, info))))
+			return;
+
+		saddr = NULL;
+	}
+
+	addr_type = ipv6_addr_type(&hdr->saddr);
+
+	/*
+	 *	Source addr check
+	 */
+
+	if (__ipv6_addr_needs_scope_id(addr_type)) {
+		iif = icmp6_iif(skb);
+	} else {
+		/*
+		 * The source device is used for looking up which routing table
+		 * to use for sending an ICMP error.
+		 */
+		iif = l3mdev_master_ifindex(skb->dev);
+	}
+
+	/*
+	 *	Must not send error if the source does not uniquely
+	 *	identify a single node (RFC2463 Section 2.4).
+	 *	We check unspecified / multicast addresses here,
+	 *	and anycast addresses will be checked later.
+	 */
+	if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
+		net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
+				    &hdr->saddr, &hdr->daddr);
+		return;
+	}
+
+	/*
+	 *	Never answer to a ICMP packet.
+	 */
+	if (is_ineligible(skb)) {
+		net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
+				    &hdr->saddr, &hdr->daddr);
+		return;
+	}
+
+	/* Needed by both icmp_global_allow and icmpv6_xmit_lock */
+	local_bh_disable();
+
+	/* Check global sysctl_icmp_msgs_per_sec ratelimit */
+	if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type))
+		goto out_bh_enable;
+
+	mip6_addr_swap(skb, parm);
+
+	sk = icmpv6_xmit_lock(net);
+	if (!sk)
+		goto out_bh_enable;
+
+	memset(&fl6, 0, sizeof(fl6));
+	fl6.flowi6_proto = IPPROTO_ICMPV6;
+	fl6.daddr = hdr->saddr;
+	if (force_saddr)
+		saddr = force_saddr;
+	if (saddr) {
+		fl6.saddr = *saddr;
+	} else if (!icmpv6_rt_has_prefsrc(sk, type, &fl6)) {
+		/* select a more meaningful saddr from input if */
+		struct net_device *in_netdev;
+
+		in_netdev = dev_get_by_index(net, parm->iif);
+		if (in_netdev) {
+			ipv6_dev_get_saddr(net, in_netdev, &fl6.daddr,
+					   inet6_sk(sk)->srcprefs,
+					   &fl6.saddr);
+			dev_put(in_netdev);
+		}
+	}
+	fl6.flowi6_mark = mark;
+	fl6.flowi6_oif = iif;
+	fl6.fl6_icmp_type = type;
+	fl6.fl6_icmp_code = code;
+	fl6.flowi6_uid = sock_net_uid(net, NULL);
+	fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
+	security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
+
+	np = inet6_sk(sk);
+
+	if (!icmpv6_xrlim_allow(sk, type, &fl6))
+		goto out;
+
+	tmp_hdr.icmp6_type = type;
+	tmp_hdr.icmp6_code = code;
+	tmp_hdr.icmp6_cksum = 0;
+	tmp_hdr.icmp6_pointer = htonl(info);
+
+	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
+		fl6.flowi6_oif = np->mcast_oif;
+	else if (!fl6.flowi6_oif)
+		fl6.flowi6_oif = np->ucast_oif;
+
+	ipcm6_init_sk(&ipc6, np);
+	ipc6.sockc.mark = mark;
+	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
+
+	dst = icmpv6_route_lookup(net, skb, sk, &fl6);
+	if (IS_ERR(dst))
+		goto out;
+
+	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
+
+	msg.skb = skb;
+	msg.offset = skb_network_offset(skb);
+	msg.type = type;
+
+	len = skb->len - msg.offset;
+	len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
+	if (len < 0) {
+		net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
+				    &hdr->saddr, &hdr->daddr);
+		goto out_dst_release;
+	}
+
+	rcu_read_lock();
+	idev = __in6_dev_get(skb->dev);
+
+	if (ip6_append_data(sk, icmpv6_getfrag, &msg,
+			    len + sizeof(struct icmp6hdr),
+			    sizeof(struct icmp6hdr),
+			    &ipc6, &fl6, (struct rt6_info *)dst,
+			    MSG_DONTWAIT)) {
+		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
+		ip6_flush_pending_frames(sk);
+	} else {
+		icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
+					   len + sizeof(struct icmp6hdr));
+	}
+	rcu_read_unlock();
+out_dst_release:
+	dst_release(dst);
+out:
+	icmpv6_xmit_unlock(sk);
+out_bh_enable:
+	local_bh_enable();
+}
+EXPORT_SYMBOL(icmp6_send);
+
+/* Slightly more convenient version of icmp6_send with drop reasons.
+ */
+void icmpv6_param_prob_reason(struct sk_buff *skb, u8 code, int pos,
+			      enum skb_drop_reason reason)
+{
+	icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL, IP6CB(skb));
+	kfree_skb_reason(skb, reason);
+}
+
+/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
+ * if sufficient data bytes are available
+ * @nhs is the size of the tunnel header(s) :
+ *  Either an IPv4 header for SIT encap
+ *         an IPv4 header + GRE header for GRE encap
+ */
+int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
+			       unsigned int data_len)
+{
+	struct in6_addr temp_saddr;
+	struct rt6_info *rt;
+	struct sk_buff *skb2;
+	u32 info = 0;
+
+	if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
+		return 1;
+
+	/* RFC 4884 (partial) support for ICMP extensions */
+	if (data_len < 128 || (data_len & 7) || skb->len < data_len)
+		data_len = 0;
+
+	skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
+
+	if (!skb2)
+		return 1;
+
+	skb_dst_drop(skb2);
+	skb_pull(skb2, nhs);
+	skb_reset_network_header(skb2);
+
+	rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
+			skb, 0);
+
+	if (rt && rt->dst.dev)
+		skb2->dev = rt->dst.dev;
+
+	ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
+
+	if (data_len) {
+		/* RFC 4884 (partial) support :
+		 * insert 0 padding at the end, before the extensions
+		 */
+		__skb_push(skb2, nhs);
+		skb_reset_network_header(skb2);
+		memmove(skb2->data, skb2->data + nhs, data_len - nhs);
+		memset(skb2->data + data_len - nhs, 0, nhs);
+		/* RFC 4884 4.5 : Length is measured in 64-bit words,
+		 * and stored in reserved[0]
+		 */
+		info = (data_len/8) << 24;
+	}
+	if (type == ICMP_TIME_EXCEEDED)
+		icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
+			   info, &temp_saddr, IP6CB(skb2));
+	else
+		icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
+			   info, &temp_saddr, IP6CB(skb2));
+	if (rt)
+		ip6_rt_put(rt);
+
+	kfree_skb(skb2);
+
+	return 0;
+}
+EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
+
+static void icmpv6_echo_reply(struct sk_buff *skb)
+{
+	struct net *net = dev_net(skb->dev);
+	struct sock *sk;
+	struct inet6_dev *idev;
+	struct ipv6_pinfo *np;
+	const struct in6_addr *saddr = NULL;
+	struct icmp6hdr *icmph = icmp6_hdr(skb);
+	struct icmp6hdr tmp_hdr;
+	struct flowi6 fl6;
+	struct icmpv6_msg msg;
+	struct dst_entry *dst;
+	struct ipcm6_cookie ipc6;
+	u32 mark = IP6_REPLY_MARK(net, skb->mark);
+	bool acast;
+	u8 type;
+
+	if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) &&
+	    net->ipv6.sysctl.icmpv6_echo_ignore_multicast)
+		return;
+
+	saddr = &ipv6_hdr(skb)->daddr;
+
+	acast = ipv6_anycast_destination(skb_dst(skb), saddr);
+	if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast)
+		return;
+
+	if (!ipv6_unicast_destination(skb) &&
+	    !(net->ipv6.sysctl.anycast_src_echo_reply && acast))
+		saddr = NULL;
+
+	if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
+		type = ICMPV6_EXT_ECHO_REPLY;
+	else
+		type = ICMPV6_ECHO_REPLY;
+
+	memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
+	tmp_hdr.icmp6_type = type;
+
+	memset(&fl6, 0, sizeof(fl6));
+	if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES)
+		fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb));
+
+	fl6.flowi6_proto = IPPROTO_ICMPV6;
+	fl6.daddr = ipv6_hdr(skb)->saddr;
+	if (saddr)
+		fl6.saddr = *saddr;
+	fl6.flowi6_oif = icmp6_iif(skb);
+	fl6.fl6_icmp_type = type;
+	fl6.flowi6_mark = mark;
+	fl6.flowi6_uid = sock_net_uid(net, NULL);
+	security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
+
+	local_bh_disable();
+	sk = icmpv6_xmit_lock(net);
+	if (!sk)
+		goto out_bh_enable;
+	np = inet6_sk(sk);
+
+	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
+		fl6.flowi6_oif = np->mcast_oif;
+	else if (!fl6.flowi6_oif)
+		fl6.flowi6_oif = np->ucast_oif;
+
+	if (ip6_dst_lookup(net, sk, &dst, &fl6))
+		goto out;
+	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
+	if (IS_ERR(dst))
+		goto out;
+
+	/* Check the ratelimit */
+	if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) ||
+	    !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6))
+		goto out_dst_release;
+
+	idev = __in6_dev_get(skb->dev);
+
+	msg.skb = skb;
+	msg.offset = 0;
+	msg.type = type;
+
+	ipcm6_init_sk(&ipc6, np);
+	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
+	ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
+	ipc6.sockc.mark = mark;
+
+	if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
+		if (!icmp_build_probe(skb, (struct icmphdr *)&tmp_hdr))
+			goto out_dst_release;
+
+	if (ip6_append_data(sk, icmpv6_getfrag, &msg,
+			    skb->len + sizeof(struct icmp6hdr),
+			    sizeof(struct icmp6hdr), &ipc6, &fl6,
+			    (struct rt6_info *)dst, MSG_DONTWAIT)) {
+		__ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
+		ip6_flush_pending_frames(sk);
+	} else {
+		icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
+					   skb->len + sizeof(struct icmp6hdr));
+	}
+out_dst_release:
+	dst_release(dst);
+out:
+	icmpv6_xmit_unlock(sk);
+out_bh_enable:
+	local_bh_enable();
+}
+
+void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
+{
+	struct inet6_skb_parm *opt = IP6CB(skb);
+	const struct inet6_protocol *ipprot;
+	int inner_offset;
+	__be16 frag_off;
+	u8 nexthdr;
+	struct net *net = dev_net(skb->dev);
+
+	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+		goto out;
+
+	seg6_icmp_srh(skb, opt);
+
+	nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
+	if (ipv6_ext_hdr(nexthdr)) {
+		/* now skip over extension headers */
+		inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
+						&nexthdr, &frag_off);
+		if (inner_offset < 0)
+			goto out;
+	} else {
+		inner_offset = sizeof(struct ipv6hdr);
+	}
+
+	/* Checkin header including 8 bytes of inner protocol header. */
+	if (!pskb_may_pull(skb, inner_offset+8))
+		goto out;
+
+	/* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
+	   Without this we will not able f.e. to make source routed
+	   pmtu discovery.
+	   Corresponding argument (opt) to notifiers is already added.
+	   --ANK (980726)
+	 */
+
+	ipprot = rcu_dereference(inet6_protos[nexthdr]);
+	if (ipprot && ipprot->err_handler)
+		ipprot->err_handler(skb, opt, type, code, inner_offset, info);
+
+	raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
+	return;
+
+out:
+	__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
+}
+
+/*
+ *	Handle icmp messages
+ */
+
+static int icmpv6_rcv(struct sk_buff *skb)
+{
+	enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
+	struct net *net = dev_net(skb->dev);
+	struct net_device *dev = icmp6_dev(skb);
+	struct inet6_dev *idev = __in6_dev_get(dev);
+	const struct in6_addr *saddr, *daddr;
+	struct icmp6hdr *hdr;
+	u8 type;
+
+	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+		struct sec_path *sp = skb_sec_path(skb);
+		int nh;
+
+		if (!(sp && sp->xvec[sp->len - 1]->props.flags &
+				 XFRM_STATE_ICMP)) {
+			reason = SKB_DROP_REASON_XFRM_POLICY;
+			goto drop_no_count;
+		}
+
+		if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
+			goto drop_no_count;
+
+		nh = skb_network_offset(skb);
+		skb_set_network_header(skb, sizeof(*hdr));
+
+		if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN,
+						skb)) {
+			reason = SKB_DROP_REASON_XFRM_POLICY;
+			goto drop_no_count;
+		}
+
+		skb_set_network_header(skb, nh);
+	}
+
+	__ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
+
+	saddr = &ipv6_hdr(skb)->saddr;
+	daddr = &ipv6_hdr(skb)->daddr;
+
+	if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
+		net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
+				    saddr, daddr);
+		goto csum_error;
+	}
+
+	if (!pskb_pull(skb, sizeof(*hdr)))
+		goto discard_it;
+
+	hdr = icmp6_hdr(skb);
+
+	type = hdr->icmp6_type;
+
+	ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
+
+	switch (type) {
+	case ICMPV6_ECHO_REQUEST:
+		if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
+			icmpv6_echo_reply(skb);
+		break;
+	case ICMPV6_EXT_ECHO_REQUEST:
+		if (!net->ipv6.sysctl.icmpv6_echo_ignore_all &&
+		    READ_ONCE(net->ipv4.sysctl_icmp_echo_enable_probe))
+			icmpv6_echo_reply(skb);
+		break;
+
+	case ICMPV6_ECHO_REPLY:
+		reason = ping_rcv(skb);
+		break;
+
+	case ICMPV6_EXT_ECHO_REPLY:
+		reason = ping_rcv(skb);
+		break;
+
+	case ICMPV6_PKT_TOOBIG:
+		/* BUGGG_FUTURE: if packet contains rthdr, we cannot update
+		   standard destination cache. Seems, only "advanced"
+		   destination cache will allow to solve this problem
+		   --ANK (980726)
+		 */
+		if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+			goto discard_it;
+		hdr = icmp6_hdr(skb);
+
+		/* to notify */
+		fallthrough;
+	case ICMPV6_DEST_UNREACH:
+	case ICMPV6_TIME_EXCEED:
+	case ICMPV6_PARAMPROB:
+		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
+		break;
+
+	case NDISC_ROUTER_SOLICITATION:
+	case NDISC_ROUTER_ADVERTISEMENT:
+	case NDISC_NEIGHBOUR_SOLICITATION:
+	case NDISC_NEIGHBOUR_ADVERTISEMENT:
+	case NDISC_REDIRECT:
+		ndisc_rcv(skb);
+		break;
+
+	case ICMPV6_MGM_QUERY:
+		igmp6_event_query(skb);
+		return 0;
+
+	case ICMPV6_MGM_REPORT:
+		igmp6_event_report(skb);
+		return 0;
+
+	case ICMPV6_MGM_REDUCTION:
+	case ICMPV6_NI_QUERY:
+	case ICMPV6_NI_REPLY:
+	case ICMPV6_MLD2_REPORT:
+	case ICMPV6_DHAAD_REQUEST:
+	case ICMPV6_DHAAD_REPLY:
+	case ICMPV6_MOBILE_PREFIX_SOL:
+	case ICMPV6_MOBILE_PREFIX_ADV:
+		break;
+
+	default:
+		/* informational */
+		if (type & ICMPV6_INFOMSG_MASK)
+			break;
+
+		net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
+				    saddr, daddr);
+
+		/*
+		 * error of unknown type.
+		 * must pass to upper level
+		 */
+
+		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
+	}
+
+	/* until the v6 path can be better sorted assume failure and
+	 * preserve the status quo behaviour for the rest of the paths to here
+	 */
+	if (reason)
+		kfree_skb_reason(skb, reason);
+	else
+		consume_skb(skb);
+
+	return 0;
+
+csum_error:
+	reason = SKB_DROP_REASON_ICMP_CSUM;
+	__ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
+discard_it:
+	__ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
+drop_no_count:
+	kfree_skb_reason(skb, reason);
+	return 0;
+}
+
+void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
+		      u8 type,
+		      const struct in6_addr *saddr,
+		      const struct in6_addr *daddr,
+		      int oif)
+{
+	memset(fl6, 0, sizeof(*fl6));
+	fl6->saddr = *saddr;
+	fl6->daddr = *daddr;
+	fl6->flowi6_proto	= IPPROTO_ICMPV6;
+	fl6->fl6_icmp_type	= type;
+	fl6->fl6_icmp_code	= 0;
+	fl6->flowi6_oif		= oif;
+	security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
+}
+
+int __init icmpv6_init(void)
+{
+	struct sock *sk;
+	int err, i;
+
+	for_each_possible_cpu(i) {
+		err = inet_ctl_sock_create(&sk, PF_INET6,
+					   SOCK_RAW, IPPROTO_ICMPV6, &init_net);
+		if (err < 0) {
+			pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
+			       err);
+			return err;
+		}
+
+		per_cpu(ipv6_icmp_sk, i) = sk;
+
+		/* Enough space for 2 64K ICMP packets, including
+		 * sk_buff struct overhead.
+		 */
+		sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
+	}
+
+	err = -EAGAIN;
+	if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
+		goto fail;
+
+	err = inet6_register_icmp_sender(icmp6_send);
+	if (err)
+		goto sender_reg_err;
+	return 0;
+
+sender_reg_err:
+	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
+fail:
+	pr_err("Failed to register ICMP6 protocol\n");
+	return err;
+}
+
+void icmpv6_cleanup(void)
+{
+	inet6_unregister_icmp_sender(icmp6_send);
+	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
+}
+
+
+static const struct icmp6_err {
+	int err;
+	int fatal;
+} tab_unreach[] = {
+	{	/* NOROUTE */
+		.err	= ENETUNREACH,
+		.fatal	= 0,
+	},
+	{	/* ADM_PROHIBITED */
+		.err	= EACCES,
+		.fatal	= 1,
+	},
+	{	/* Was NOT_NEIGHBOUR, now reserved */
+		.err	= EHOSTUNREACH,
+		.fatal	= 0,
+	},
+	{	/* ADDR_UNREACH	*/
+		.err	= EHOSTUNREACH,
+		.fatal	= 0,
+	},
+	{	/* PORT_UNREACH	*/
+		.err	= ECONNREFUSED,
+		.fatal	= 1,
+	},
+	{	/* POLICY_FAIL */
+		.err	= EACCES,
+		.fatal	= 1,
+	},
+	{	/* REJECT_ROUTE	*/
+		.err	= EACCES,
+		.fatal	= 1,
+	},
+};
+
+int icmpv6_err_convert(u8 type, u8 code, int *err)
+{
+	int fatal = 0;
+
+	*err = EPROTO;
+
+	switch (type) {
+	case ICMPV6_DEST_UNREACH:
+		fatal = 1;
+		if (code < ARRAY_SIZE(tab_unreach)) {
+			*err  = tab_unreach[code].err;
+			fatal = tab_unreach[code].fatal;
+		}
+		break;
+
+	case ICMPV6_PKT_TOOBIG:
+		*err = EMSGSIZE;
+		break;
+
+	case ICMPV6_PARAMPROB:
+		*err = EPROTO;
+		fatal = 1;
+		break;
+
+	case ICMPV6_TIME_EXCEED:
+		*err = EHOSTUNREACH;
+		break;
+	}
+
+	return fatal;
+}
+EXPORT_SYMBOL(icmpv6_err_convert);
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table ipv6_icmp_table_template[] = {
+	{
+		.procname	= "ratelimit",
+		.data		= &init_net.ipv6.sysctl.icmpv6_time,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_ms_jiffies,
+	},
+	{
+		.procname	= "echo_ignore_all",
+		.data		= &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler = proc_dou8vec_minmax,
+	},
+	{
+		.procname	= "echo_ignore_multicast",
+		.data		= &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler = proc_dou8vec_minmax,
+	},
+	{
+		.procname	= "echo_ignore_anycast",
+		.data		= &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast,
+		.maxlen		= sizeof(u8),
+		.mode		= 0644,
+		.proc_handler = proc_dou8vec_minmax,
+	},
+	{
+		.procname	= "ratemask",
+		.data		= &init_net.ipv6.sysctl.icmpv6_ratemask_ptr,
+		.maxlen		= ICMPV6_MSG_MAX + 1,
+		.mode		= 0644,
+		.proc_handler = proc_do_large_bitmap,
+	},
+	{ },
+};
+
+struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
+{
+	struct ctl_table *table;
+
+	table = kmemdup(ipv6_icmp_table_template,
+			sizeof(ipv6_icmp_table_template),
+			GFP_KERNEL);
+
+	if (table) {
+		table[0].data = &net->ipv6.sysctl.icmpv6_time;
+		table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
+		table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast;
+		table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast;
+		table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr;
+	}
+	return table;
+}
+#endif