v4.19.13 snapshot.
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
new file mode 100644
index 0000000..2356b4a
--- /dev/null
+++ b/net/ipv6/proc.c
@@ -0,0 +1,321 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		This file implements the various access functions for the
+ *		PROC file system.  This is very similar to the IPv4 version,
+ *		except it reports the sockets in the INET6 address family.
+ *
+ * Authors:	David S. Miller (davem@caip.rutgers.edu)
+ *		YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
+ *
+ *		This program 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 of the License, or (at your option) any later version.
+ */
+#include <linux/socket.h>
+#include <linux/net.h>
+#include <linux/ipv6.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/stddef.h>
+#include <linux/export.h>
+#include <net/net_namespace.h>
+#include <net/ip.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/transp_v6.h>
+#include <net/ipv6.h>
+
+#define MAX4(a, b, c, d) \
+	max_t(u32, max_t(u32, a, b), max_t(u32, c, d))
+#define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \
+			IPSTATS_MIB_MAX, ICMP_MIB_MAX)
+
+static int sockstat6_seq_show(struct seq_file *seq, void *v)
+{
+	struct net *net = seq->private;
+
+	seq_printf(seq, "TCP6: inuse %d\n",
+		       sock_prot_inuse_get(net, &tcpv6_prot));
+	seq_printf(seq, "UDP6: inuse %d\n",
+		       sock_prot_inuse_get(net, &udpv6_prot));
+	seq_printf(seq, "UDPLITE6: inuse %d\n",
+			sock_prot_inuse_get(net, &udplitev6_prot));
+	seq_printf(seq, "RAW6: inuse %d\n",
+		       sock_prot_inuse_get(net, &rawv6_prot));
+	seq_printf(seq, "FRAG6: inuse %u memory %lu\n",
+		   atomic_read(&net->ipv6.frags.rhashtable.nelems),
+		   frag_mem_limit(&net->ipv6.frags));
+	return 0;
+}
+
+static const struct snmp_mib snmp6_ipstats_list[] = {
+/* ipv6 mib according to RFC 2465 */
+	SNMP_MIB_ITEM("Ip6InReceives", IPSTATS_MIB_INPKTS),
+	SNMP_MIB_ITEM("Ip6InHdrErrors", IPSTATS_MIB_INHDRERRORS),
+	SNMP_MIB_ITEM("Ip6InTooBigErrors", IPSTATS_MIB_INTOOBIGERRORS),
+	SNMP_MIB_ITEM("Ip6InNoRoutes", IPSTATS_MIB_INNOROUTES),
+	SNMP_MIB_ITEM("Ip6InAddrErrors", IPSTATS_MIB_INADDRERRORS),
+	SNMP_MIB_ITEM("Ip6InUnknownProtos", IPSTATS_MIB_INUNKNOWNPROTOS),
+	SNMP_MIB_ITEM("Ip6InTruncatedPkts", IPSTATS_MIB_INTRUNCATEDPKTS),
+	SNMP_MIB_ITEM("Ip6InDiscards", IPSTATS_MIB_INDISCARDS),
+	SNMP_MIB_ITEM("Ip6InDelivers", IPSTATS_MIB_INDELIVERS),
+	SNMP_MIB_ITEM("Ip6OutForwDatagrams", IPSTATS_MIB_OUTFORWDATAGRAMS),
+	SNMP_MIB_ITEM("Ip6OutRequests", IPSTATS_MIB_OUTPKTS),
+	SNMP_MIB_ITEM("Ip6OutDiscards", IPSTATS_MIB_OUTDISCARDS),
+	SNMP_MIB_ITEM("Ip6OutNoRoutes", IPSTATS_MIB_OUTNOROUTES),
+	SNMP_MIB_ITEM("Ip6ReasmTimeout", IPSTATS_MIB_REASMTIMEOUT),
+	SNMP_MIB_ITEM("Ip6ReasmReqds", IPSTATS_MIB_REASMREQDS),
+	SNMP_MIB_ITEM("Ip6ReasmOKs", IPSTATS_MIB_REASMOKS),
+	SNMP_MIB_ITEM("Ip6ReasmFails", IPSTATS_MIB_REASMFAILS),
+	SNMP_MIB_ITEM("Ip6FragOKs", IPSTATS_MIB_FRAGOKS),
+	SNMP_MIB_ITEM("Ip6FragFails", IPSTATS_MIB_FRAGFAILS),
+	SNMP_MIB_ITEM("Ip6FragCreates", IPSTATS_MIB_FRAGCREATES),
+	SNMP_MIB_ITEM("Ip6InMcastPkts", IPSTATS_MIB_INMCASTPKTS),
+	SNMP_MIB_ITEM("Ip6OutMcastPkts", IPSTATS_MIB_OUTMCASTPKTS),
+	SNMP_MIB_ITEM("Ip6InOctets", IPSTATS_MIB_INOCTETS),
+	SNMP_MIB_ITEM("Ip6OutOctets", IPSTATS_MIB_OUTOCTETS),
+	SNMP_MIB_ITEM("Ip6InMcastOctets", IPSTATS_MIB_INMCASTOCTETS),
+	SNMP_MIB_ITEM("Ip6OutMcastOctets", IPSTATS_MIB_OUTMCASTOCTETS),
+	SNMP_MIB_ITEM("Ip6InBcastOctets", IPSTATS_MIB_INBCASTOCTETS),
+	SNMP_MIB_ITEM("Ip6OutBcastOctets", IPSTATS_MIB_OUTBCASTOCTETS),
+	/* IPSTATS_MIB_CSUMERRORS is not relevant in IPv6 (no checksum) */
+	SNMP_MIB_ITEM("Ip6InNoECTPkts", IPSTATS_MIB_NOECTPKTS),
+	SNMP_MIB_ITEM("Ip6InECT1Pkts", IPSTATS_MIB_ECT1PKTS),
+	SNMP_MIB_ITEM("Ip6InECT0Pkts", IPSTATS_MIB_ECT0PKTS),
+	SNMP_MIB_ITEM("Ip6InCEPkts", IPSTATS_MIB_CEPKTS),
+	SNMP_MIB_SENTINEL
+};
+
+static const struct snmp_mib snmp6_icmp6_list[] = {
+/* icmpv6 mib according to RFC 2466 */
+	SNMP_MIB_ITEM("Icmp6InMsgs", ICMP6_MIB_INMSGS),
+	SNMP_MIB_ITEM("Icmp6InErrors", ICMP6_MIB_INERRORS),
+	SNMP_MIB_ITEM("Icmp6OutMsgs", ICMP6_MIB_OUTMSGS),
+	SNMP_MIB_ITEM("Icmp6OutErrors", ICMP6_MIB_OUTERRORS),
+	SNMP_MIB_ITEM("Icmp6InCsumErrors", ICMP6_MIB_CSUMERRORS),
+	SNMP_MIB_SENTINEL
+};
+
+/* RFC 4293 v6 ICMPMsgStatsTable; named items for RFC 2466 compatibility */
+static const char *const icmp6type2name[256] = {
+	[ICMPV6_DEST_UNREACH] = "DestUnreachs",
+	[ICMPV6_PKT_TOOBIG] = "PktTooBigs",
+	[ICMPV6_TIME_EXCEED] = "TimeExcds",
+	[ICMPV6_PARAMPROB] = "ParmProblems",
+	[ICMPV6_ECHO_REQUEST] = "Echos",
+	[ICMPV6_ECHO_REPLY] = "EchoReplies",
+	[ICMPV6_MGM_QUERY] = "GroupMembQueries",
+	[ICMPV6_MGM_REPORT] = "GroupMembResponses",
+	[ICMPV6_MGM_REDUCTION] = "GroupMembReductions",
+	[ICMPV6_MLD2_REPORT] = "MLDv2Reports",
+	[NDISC_ROUTER_ADVERTISEMENT] = "RouterAdvertisements",
+	[NDISC_ROUTER_SOLICITATION] = "RouterSolicits",
+	[NDISC_NEIGHBOUR_ADVERTISEMENT] = "NeighborAdvertisements",
+	[NDISC_NEIGHBOUR_SOLICITATION] = "NeighborSolicits",
+	[NDISC_REDIRECT] = "Redirects",
+};
+
+
+static const struct snmp_mib snmp6_udp6_list[] = {
+	SNMP_MIB_ITEM("Udp6InDatagrams", UDP_MIB_INDATAGRAMS),
+	SNMP_MIB_ITEM("Udp6NoPorts", UDP_MIB_NOPORTS),
+	SNMP_MIB_ITEM("Udp6InErrors", UDP_MIB_INERRORS),
+	SNMP_MIB_ITEM("Udp6OutDatagrams", UDP_MIB_OUTDATAGRAMS),
+	SNMP_MIB_ITEM("Udp6RcvbufErrors", UDP_MIB_RCVBUFERRORS),
+	SNMP_MIB_ITEM("Udp6SndbufErrors", UDP_MIB_SNDBUFERRORS),
+	SNMP_MIB_ITEM("Udp6InCsumErrors", UDP_MIB_CSUMERRORS),
+	SNMP_MIB_ITEM("Udp6IgnoredMulti", UDP_MIB_IGNOREDMULTI),
+	SNMP_MIB_SENTINEL
+};
+
+static const struct snmp_mib snmp6_udplite6_list[] = {
+	SNMP_MIB_ITEM("UdpLite6InDatagrams", UDP_MIB_INDATAGRAMS),
+	SNMP_MIB_ITEM("UdpLite6NoPorts", UDP_MIB_NOPORTS),
+	SNMP_MIB_ITEM("UdpLite6InErrors", UDP_MIB_INERRORS),
+	SNMP_MIB_ITEM("UdpLite6OutDatagrams", UDP_MIB_OUTDATAGRAMS),
+	SNMP_MIB_ITEM("UdpLite6RcvbufErrors", UDP_MIB_RCVBUFERRORS),
+	SNMP_MIB_ITEM("UdpLite6SndbufErrors", UDP_MIB_SNDBUFERRORS),
+	SNMP_MIB_ITEM("UdpLite6InCsumErrors", UDP_MIB_CSUMERRORS),
+	SNMP_MIB_SENTINEL
+};
+
+static void snmp6_seq_show_icmpv6msg(struct seq_file *seq, atomic_long_t *smib)
+{
+	char name[32];
+	int i;
+
+	/* print by name -- deprecated items */
+	for (i = 0; i < ICMP6MSG_MIB_MAX; i++) {
+		int icmptype;
+		const char *p;
+
+		icmptype = i & 0xff;
+		p = icmp6type2name[icmptype];
+		if (!p)	/* don't print un-named types here */
+			continue;
+		snprintf(name, sizeof(name), "Icmp6%s%s",
+			i & 0x100 ? "Out" : "In", p);
+		seq_printf(seq, "%-32s\t%lu\n", name,
+			   atomic_long_read(smib + i));
+	}
+
+	/* print by number (nonzero only) - ICMPMsgStat format */
+	for (i = 0; i < ICMP6MSG_MIB_MAX; i++) {
+		unsigned long val;
+
+		val = atomic_long_read(smib + i);
+		if (!val)
+			continue;
+		snprintf(name, sizeof(name), "Icmp6%sType%u",
+			i & 0x100 ?  "Out" : "In", i & 0xff);
+		seq_printf(seq, "%-32s\t%lu\n", name, val);
+	}
+}
+
+/* can be called either with percpu mib (pcpumib != NULL),
+ * or shared one (smib != NULL)
+ */
+static void snmp6_seq_show_item(struct seq_file *seq, void __percpu *pcpumib,
+				atomic_long_t *smib,
+				const struct snmp_mib *itemlist)
+{
+	unsigned long buff[SNMP_MIB_MAX];
+	int i;
+
+	if (pcpumib) {
+		memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+
+		snmp_get_cpu_field_batch(buff, itemlist, pcpumib);
+		for (i = 0; itemlist[i].name; i++)
+			seq_printf(seq, "%-32s\t%lu\n",
+				   itemlist[i].name, buff[i]);
+	} else {
+		for (i = 0; itemlist[i].name; i++)
+			seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name,
+				   atomic_long_read(smib + itemlist[i].entry));
+	}
+}
+
+static void snmp6_seq_show_item64(struct seq_file *seq, void __percpu *mib,
+				  const struct snmp_mib *itemlist, size_t syncpoff)
+{
+	u64 buff64[SNMP_MIB_MAX];
+	int i;
+
+	memset(buff64, 0, sizeof(u64) * SNMP_MIB_MAX);
+
+	snmp_get_cpu_field64_batch(buff64, itemlist, mib, syncpoff);
+	for (i = 0; itemlist[i].name; i++)
+		seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name, buff64[i]);
+}
+
+static int snmp6_seq_show(struct seq_file *seq, void *v)
+{
+	struct net *net = (struct net *)seq->private;
+
+	snmp6_seq_show_item64(seq, net->mib.ipv6_statistics,
+			    snmp6_ipstats_list, offsetof(struct ipstats_mib, syncp));
+	snmp6_seq_show_item(seq, net->mib.icmpv6_statistics,
+			    NULL, snmp6_icmp6_list);
+	snmp6_seq_show_icmpv6msg(seq, net->mib.icmpv6msg_statistics->mibs);
+	snmp6_seq_show_item(seq, net->mib.udp_stats_in6,
+			    NULL, snmp6_udp6_list);
+	snmp6_seq_show_item(seq, net->mib.udplite_stats_in6,
+			    NULL, snmp6_udplite6_list);
+	return 0;
+}
+
+static int snmp6_dev_seq_show(struct seq_file *seq, void *v)
+{
+	struct inet6_dev *idev = (struct inet6_dev *)seq->private;
+
+	seq_printf(seq, "%-32s\t%u\n", "ifIndex", idev->dev->ifindex);
+	snmp6_seq_show_item64(seq, idev->stats.ipv6,
+			    snmp6_ipstats_list, offsetof(struct ipstats_mib, syncp));
+	snmp6_seq_show_item(seq, NULL, idev->stats.icmpv6dev->mibs,
+			    snmp6_icmp6_list);
+	snmp6_seq_show_icmpv6msg(seq, idev->stats.icmpv6msgdev->mibs);
+	return 0;
+}
+
+int snmp6_register_dev(struct inet6_dev *idev)
+{
+	struct proc_dir_entry *p;
+	struct net *net;
+
+	if (!idev || !idev->dev)
+		return -EINVAL;
+
+	net = dev_net(idev->dev);
+	if (!net->mib.proc_net_devsnmp6)
+		return -ENOENT;
+
+	p = proc_create_single_data(idev->dev->name, 0444,
+			net->mib.proc_net_devsnmp6, snmp6_dev_seq_show, idev);
+	if (!p)
+		return -ENOMEM;
+
+	idev->stats.proc_dir_entry = p;
+	return 0;
+}
+
+int snmp6_unregister_dev(struct inet6_dev *idev)
+{
+	struct net *net = dev_net(idev->dev);
+	if (!net->mib.proc_net_devsnmp6)
+		return -ENOENT;
+	if (!idev->stats.proc_dir_entry)
+		return -EINVAL;
+	proc_remove(idev->stats.proc_dir_entry);
+	idev->stats.proc_dir_entry = NULL;
+	return 0;
+}
+
+static int __net_init ipv6_proc_init_net(struct net *net)
+{
+	if (!proc_create_net_single("sockstat6", 0444, net->proc_net,
+			sockstat6_seq_show, NULL))
+		return -ENOMEM;
+
+	if (!proc_create_net_single("snmp6", 0444, net->proc_net,
+			snmp6_seq_show, NULL))
+		goto proc_snmp6_fail;
+
+	net->mib.proc_net_devsnmp6 = proc_mkdir("dev_snmp6", net->proc_net);
+	if (!net->mib.proc_net_devsnmp6)
+		goto proc_dev_snmp6_fail;
+	return 0;
+
+proc_dev_snmp6_fail:
+	remove_proc_entry("snmp6", net->proc_net);
+proc_snmp6_fail:
+	remove_proc_entry("sockstat6", net->proc_net);
+	return -ENOMEM;
+}
+
+static void __net_exit ipv6_proc_exit_net(struct net *net)
+{
+	remove_proc_entry("sockstat6", net->proc_net);
+	remove_proc_entry("dev_snmp6", net->proc_net);
+	remove_proc_entry("snmp6", net->proc_net);
+}
+
+static struct pernet_operations ipv6_proc_ops = {
+	.init = ipv6_proc_init_net,
+	.exit = ipv6_proc_exit_net,
+};
+
+int __init ipv6_misc_proc_init(void)
+{
+	return register_pernet_subsys(&ipv6_proc_ops);
+}
+
+void ipv6_misc_proc_exit(void)
+{
+	unregister_pernet_subsys(&ipv6_proc_ops);
+}