1 files changed, 387 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_proto_icmpv6.c b/net/netfilter/nf_conntrack_proto_icmpv6.c
new file mode 100644
index 000000000000..bed07b998a10
--- /dev/null
+++ b/net/netfilter/nf_conntrack_proto_icmpv6.c
@@ -0,0 +1,387 @@
+/*
+ * Copyright (C)2003,2004 USAGI/WIDE Project
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Author:
+ *	Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
+ */
+
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/in6.h>
+#include <linux/icmpv6.h>
+#include <linux/ipv6.h>
+#include <net/ipv6.h>
+#include <net/ip6_checksum.h>
+#include <linux/seq_file.h>
+#include <linux/netfilter_ipv6.h>
+#include <net/netfilter/nf_conntrack_tuple.h>
+#include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_timeout.h>
+#include <net/netfilter/nf_conntrack_zones.h>
+#include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
+#include <net/netfilter/nf_log.h>
+
+static const unsigned int nf_ct_icmpv6_timeout = 30*HZ;
+
+static inline struct nf_icmp_net *icmpv6_pernet(struct net *net)
+{
+	return &net->ct.nf_ct_proto.icmpv6;
+}
+
+static bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
+				unsigned int dataoff,
+				struct net *net,
+				struct nf_conntrack_tuple *tuple)
+{
+	const struct icmp6hdr *hp;
+	struct icmp6hdr _hdr;
+
+	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
+	if (hp == NULL)
+		return false;
+	tuple->dst.u.icmp.type = hp->icmp6_type;
+	tuple->src.u.icmp.id = hp->icmp6_identifier;
+	tuple->dst.u.icmp.code = hp->icmp6_code;
+
+	return true;
+}
+
+/* Add 1; spaces filled with 0. */
+static const u_int8_t invmap[] = {
+	[ICMPV6_ECHO_REQUEST - 128]	= ICMPV6_ECHO_REPLY + 1,
+	[ICMPV6_ECHO_REPLY - 128]	= ICMPV6_ECHO_REQUEST + 1,
+	[ICMPV6_NI_QUERY - 128]		= ICMPV6_NI_REPLY + 1,
+	[ICMPV6_NI_REPLY - 128]		= ICMPV6_NI_QUERY + 1
+};
+
+static const u_int8_t noct_valid_new[] = {
+	[ICMPV6_MGM_QUERY - 130] = 1,
+	[ICMPV6_MGM_REPORT - 130] = 1,
+	[ICMPV6_MGM_REDUCTION - 130] = 1,
+	[NDISC_ROUTER_SOLICITATION - 130] = 1,
+	[NDISC_ROUTER_ADVERTISEMENT - 130] = 1,
+	[NDISC_NEIGHBOUR_SOLICITATION - 130] = 1,
+	[NDISC_NEIGHBOUR_ADVERTISEMENT - 130] = 1,
+	[ICMPV6_MLD2_REPORT - 130] = 1
+};
+
+static bool icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple,
+				const struct nf_conntrack_tuple *orig)
+{
+	int type = orig->dst.u.icmp.type - 128;
+	if (type < 0 || type >= sizeof(invmap) || !invmap[type])
+		return false;
+
+	tuple->src.u.icmp.id   = orig->src.u.icmp.id;
+	tuple->dst.u.icmp.type = invmap[type] - 1;
+	tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
+	return true;
+}
+
+static unsigned int *icmpv6_get_timeouts(struct net *net)
+{
+	return &icmpv6_pernet(net)->timeout;
+}
+
+/* Returns verdict for packet, or -1 for invalid. */
+static int icmpv6_packet(struct nf_conn *ct,
+		       const struct sk_buff *skb,
+		       unsigned int dataoff,
+		       enum ip_conntrack_info ctinfo)
+{
+	unsigned int *timeout = nf_ct_timeout_lookup(ct);
+
+	if (!timeout)
+		timeout = icmpv6_get_timeouts(nf_ct_net(ct));
+
+	/* Do not immediately delete the connection after the first
+	   successful reply to avoid excessive conntrackd traffic
+	   and also to handle correctly ICMP echo reply duplicates. */
+	nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
+
+	return NF_ACCEPT;
+}
+
+/* Called when a new connection for this protocol found. */
+static bool icmpv6_new(struct nf_conn *ct, const struct sk_buff *skb,
+		       unsigned int dataoff)
+{
+	static const u_int8_t valid_new[] = {
+		[ICMPV6_ECHO_REQUEST - 128] = 1,
+		[ICMPV6_NI_QUERY - 128] = 1
+	};
+	int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
+
+	if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
+		/* Can't create a new ICMPv6 `conn' with this. */
+		pr_debug("icmpv6: can't create new conn with type %u\n",
+			 type + 128);
+		nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
+		return false;
+	}
+	return true;
+}
+
+static int
+icmpv6_error_message(struct net *net, struct nf_conn *tmpl,
+		     struct sk_buff *skb,
+		     unsigned int icmp6off)
+{
+	struct nf_conntrack_tuple intuple, origtuple;
+	const struct nf_conntrack_tuple_hash *h;
+	const struct nf_conntrack_l4proto *inproto;
+	enum ip_conntrack_info ctinfo;
+	struct nf_conntrack_zone tmp;
+
+	WARN_ON(skb_nfct(skb));
+
+	/* Are they talking about one of our connections? */
+	if (!nf_ct_get_tuplepr(skb,
+			       skb_network_offset(skb)
+				+ sizeof(struct ipv6hdr)
+				+ sizeof(struct icmp6hdr),
+			       PF_INET6, net, &origtuple)) {
+		pr_debug("icmpv6_error: Can't get tuple\n");
+		return -NF_ACCEPT;
+	}
+
+	/* rcu_read_lock()ed by nf_hook_thresh */
+	inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum);
+
+	/* Ordinarily, we'd expect the inverted tupleproto, but it's
+	   been preserved inside the ICMP. */
+	if (!nf_ct_invert_tuple(&intuple, &origtuple, inproto)) {
+		pr_debug("icmpv6_error: Can't invert tuple\n");
+		return -NF_ACCEPT;
+	}
+
+	ctinfo = IP_CT_RELATED;
+
+	h = nf_conntrack_find_get(net, nf_ct_zone_tmpl(tmpl, skb, &tmp),
+				  &intuple);
+	if (!h) {
+		pr_debug("icmpv6_error: no match\n");
+		return -NF_ACCEPT;
+	} else {
+		if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
+			ctinfo += IP_CT_IS_REPLY;
+	}
+
+	/* Update skb to refer to this connection */
+	nf_ct_set(skb, nf_ct_tuplehash_to_ctrack(h), ctinfo);
+	return NF_ACCEPT;
+}
+
+static void icmpv6_error_log(const struct sk_buff *skb, struct net *net,
+			     u8 pf, const char *msg)
+{
+	nf_l4proto_log_invalid(skb, net, pf, IPPROTO_ICMPV6, "%s", msg);
+}
+
+static int
+icmpv6_error(struct net *net, struct nf_conn *tmpl,
+	     struct sk_buff *skb, unsigned int dataoff,
+	     u8 pf, unsigned int hooknum)
+{
+	const struct icmp6hdr *icmp6h;
+	struct icmp6hdr _ih;
+	int type;
+
+	icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
+	if (icmp6h == NULL) {
+		icmpv6_error_log(skb, net, pf, "short packet");
+		return -NF_ACCEPT;
+	}
+
+	if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
+	    nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) {
+		icmpv6_error_log(skb, net, pf, "ICMPv6 checksum failed");
+		return -NF_ACCEPT;
+	}
+
+	type = icmp6h->icmp6_type - 130;
+	if (type >= 0 && type < sizeof(noct_valid_new) &&
+	    noct_valid_new[type]) {
+		nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
+		return NF_ACCEPT;
+	}
+
+	/* is not error message ? */
+	if (icmp6h->icmp6_type >= 128)
+		return NF_ACCEPT;
+
+	return icmpv6_error_message(net, tmpl, skb, dataoff);
+}
+
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
+				  const struct nf_conntrack_tuple *t)
+{
+	if (nla_put_be16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id) ||
+	    nla_put_u8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type) ||
+	    nla_put_u8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code))
+		goto nla_put_failure;
+	return 0;
+
+nla_put_failure:
+	return -1;
+}
+
+static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
+	[CTA_PROTO_ICMPV6_TYPE]	= { .type = NLA_U8 },
+	[CTA_PROTO_ICMPV6_CODE]	= { .type = NLA_U8 },
+	[CTA_PROTO_ICMPV6_ID]	= { .type = NLA_U16 },
+};
+
+static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
+				struct nf_conntrack_tuple *tuple)
+{
+	if (!tb[CTA_PROTO_ICMPV6_TYPE] ||
+	    !tb[CTA_PROTO_ICMPV6_CODE] ||
+	    !tb[CTA_PROTO_ICMPV6_ID])
+		return -EINVAL;
+
+	tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
+	tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
+	tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
+
+	if (tuple->dst.u.icmp.type < 128 ||
+	    tuple->dst.u.icmp.type - 128 >= sizeof(invmap) ||
+	    !invmap[tuple->dst.u.icmp.type - 128])
+		return -EINVAL;
+
+	return 0;
+}
+
+static unsigned int icmpv6_nlattr_tuple_size(void)
+{
+	static unsigned int size __read_mostly;
+
+	if (!size)
+		size = nla_policy_len(icmpv6_nla_policy, CTA_PROTO_MAX + 1);
+
+	return size;
+}
+#endif
+
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_cttimeout.h>
+
+static int icmpv6_timeout_nlattr_to_obj(struct nlattr *tb[],
+					struct net *net, void *data)
+{
+	unsigned int *timeout = data;
+	struct nf_icmp_net *in = icmpv6_pernet(net);
+
+	if (!timeout)
+		timeout = icmpv6_get_timeouts(net);
+	if (tb[CTA_TIMEOUT_ICMPV6_TIMEOUT]) {
+		*timeout =
+		    ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMPV6_TIMEOUT])) * HZ;
+	} else {
+		/* Set default ICMPv6 timeout. */
+		*timeout = in->timeout;
+	}
+	return 0;
+}
+
+static int
+icmpv6_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
+{
+	const unsigned int *timeout = data;
+
+	if (nla_put_be32(skb, CTA_TIMEOUT_ICMPV6_TIMEOUT, htonl(*timeout / HZ)))
+		goto nla_put_failure;
+	return 0;
+
+nla_put_failure:
+	return -ENOSPC;
+}
+
+static const struct nla_policy
+icmpv6_timeout_nla_policy[CTA_TIMEOUT_ICMPV6_MAX+1] = {
+	[CTA_TIMEOUT_ICMPV6_TIMEOUT]	= { .type = NLA_U32 },
+};
+#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table icmpv6_sysctl_table[] = {
+	{
+		.procname	= "nf_conntrack_icmpv6_timeout",
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+	{ }
+};
+#endif /* CONFIG_SYSCTL */
+
+static int icmpv6_kmemdup_sysctl_table(struct nf_proto_net *pn,
+				       struct nf_icmp_net *in)
+{
+#ifdef CONFIG_SYSCTL
+	pn->ctl_table = kmemdup(icmpv6_sysctl_table,
+				sizeof(icmpv6_sysctl_table),
+				GFP_KERNEL);
+	if (!pn->ctl_table)
+		return -ENOMEM;
+
+	pn->ctl_table[0].data = &in->timeout;
+#endif
+	return 0;
+}
+
+static int icmpv6_init_net(struct net *net, u_int16_t proto)
+{
+	struct nf_icmp_net *in = icmpv6_pernet(net);
+	struct nf_proto_net *pn = &in->pn;
+
+	in->timeout = nf_ct_icmpv6_timeout;
+
+	return icmpv6_kmemdup_sysctl_table(pn, in);
+}
+
+static struct nf_proto_net *icmpv6_get_net_proto(struct net *net)
+{
+	return &net->ct.nf_ct_proto.icmpv6.pn;
+}
+
+const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 =
+{
+	.l3proto		= PF_INET6,
+	.l4proto		= IPPROTO_ICMPV6,
+	.pkt_to_tuple		= icmpv6_pkt_to_tuple,
+	.invert_tuple		= icmpv6_invert_tuple,
+	.packet			= icmpv6_packet,
+	.new			= icmpv6_new,
+	.error			= icmpv6_error,
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
+	.tuple_to_nlattr	= icmpv6_tuple_to_nlattr,
+	.nlattr_tuple_size	= icmpv6_nlattr_tuple_size,
+	.nlattr_to_tuple	= icmpv6_nlattr_to_tuple,
+	.nla_policy		= icmpv6_nla_policy,
+#endif
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
+	.ctnl_timeout		= {
+		.nlattr_to_obj	= icmpv6_timeout_nlattr_to_obj,
+		.obj_to_nlattr	= icmpv6_timeout_obj_to_nlattr,
+		.nlattr_max	= CTA_TIMEOUT_ICMP_MAX,
+		.obj_size	= sizeof(unsigned int),
+		.nla_policy	= icmpv6_timeout_nla_policy,
+	},
+#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
+	.init_net		= icmpv6_init_net,
+	.get_net_proto		= icmpv6_get_net_proto,
+};