[mirror_ubuntu-disco-kernel.git] / net / ipv4 / netfilter / nf_conntrack_proto_icmp.c

/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
 * (C) 2006-2010 Patrick McHardy <kaber@trash.net>
 *
 * 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.
 */

#include <linux/types.h>
#include <linux/timer.h>
#include <linux/netfilter.h>
#include <linux/in.h>
#include <linux/icmp.h>
#include <linux/seq_file.h>
#include <net/ip.h>
#include <net/checksum.h>
#include <linux/netfilter_ipv4.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_zones.h>
#include <net/netfilter/nf_log.h>

static unsigned int nf_ct_icmp_timeout __read_mostly = 30*HZ;

static inline struct nf_icmp_net *icmp_pernet(struct net *net)
{
	return &net->ct.nf_ct_proto.icmp;
}

static bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
			      struct net *net, struct nf_conntrack_tuple *tuple)
{
	const struct icmphdr *hp;
	struct icmphdr _hdr;

	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	if (hp == NULL)
		return false;

	tuple->dst.u.icmp.type = hp->type;
	tuple->src.u.icmp.id = hp->un.echo.id;
	tuple->dst.u.icmp.code = hp->code;

	return true;
}

/* Add 1; spaces filled with 0. */
static const u_int8_t invmap[] = {
	[ICMP_ECHO] = ICMP_ECHOREPLY + 1,
	[ICMP_ECHOREPLY] = ICMP_ECHO + 1,
	[ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1,
	[ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1,
	[ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1,
	[ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1,
	[ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1,
	[ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1
};

static bool icmp_invert_tuple(struct nf_conntrack_tuple *tuple,
			      const struct nf_conntrack_tuple *orig)
{
	if (orig->dst.u.icmp.type >= sizeof(invmap) ||
	    !invmap[orig->dst.u.icmp.type])
		return false;

	tuple->src.u.icmp.id = orig->src.u.icmp.id;
	tuple->dst.u.icmp.type = invmap[orig->dst.u.icmp.type] - 1;
	tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
	return true;
}

static unsigned int *icmp_get_timeouts(struct net *net)
{
	return &icmp_pernet(net)->timeout;
}

/* Returns verdict for packet, or -1 for invalid. */
static int icmp_packet(struct nf_conn *ct,
		       const struct sk_buff *skb,
		       unsigned int dataoff,
		       enum ip_conntrack_info ctinfo,
		       unsigned int *timeout)
{
	/* 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 icmp_new(struct nf_conn *ct, const struct sk_buff *skb,
		     unsigned int dataoff, unsigned int *timeouts)
{
	static const u_int8_t valid_new[] = {
		[ICMP_ECHO] = 1,
		[ICMP_TIMESTAMP] = 1,
		[ICMP_INFO_REQUEST] = 1,
		[ICMP_ADDRESS] = 1
	};

	if (ct->tuplehash[0].tuple.dst.u.icmp.type >= sizeof(valid_new) ||
	    !valid_new[ct->tuplehash[0].tuple.dst.u.icmp.type]) {
		/* Can't create a new ICMP `conn' with this. */
		pr_debug("icmp: can't create new conn with type %u\n",
			 ct->tuplehash[0].tuple.dst.u.icmp.type);
		nf_ct_dump_tuple_ip(&ct->tuplehash[0].tuple);
		return false;
	}
	return true;
}

/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
static int
icmp_error_message(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
		 unsigned int hooknum)
{
	struct nf_conntrack_tuple innertuple, origtuple;
	const struct nf_conntrack_l4proto *innerproto;
	const struct nf_conntrack_tuple_hash *h;
	const struct nf_conntrack_zone *zone;
	enum ip_conntrack_info ctinfo;
	struct nf_conntrack_zone tmp;

	WARN_ON(skb_nfct(skb));
	zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);

	/* Are they talking about one of our connections? */
	if (!nf_ct_get_tuplepr(skb,
			       skb_network_offset(skb) + ip_hdrlen(skb)
						       + sizeof(struct icmphdr),
			       PF_INET, net, &origtuple)) {
		pr_debug("icmp_error_message: failed to get tuple\n");
		return -NF_ACCEPT;
	}

	/* rcu_read_lock()ed by nf_hook_thresh */
	innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum);

	/* Ordinarily, we'd expect the inverted tupleproto, but it's
	   been preserved inside the ICMP. */
	if (!nf_ct_invert_tuple(&innertuple, &origtuple,
				&nf_conntrack_l3proto_ipv4, innerproto)) {
		pr_debug("icmp_error_message: no match\n");
		return -NF_ACCEPT;
	}

	ctinfo = IP_CT_RELATED;

	h = nf_conntrack_find_get(net, zone, &innertuple);
	if (!h) {
		pr_debug("icmp_error_message: no match\n");
		return -NF_ACCEPT;
	}

	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 icmp_error_log(const struct sk_buff *skb, struct net *net,
			   u8 pf, const char *msg)
{
	nf_l4proto_log_invalid(skb, net, pf, IPPROTO_ICMP, "%s", msg);
}

/* Small and modified version of icmp_rcv */
static int
icmp_error(struct net *net, struct nf_conn *tmpl,
	   struct sk_buff *skb, unsigned int dataoff,
	   u8 pf, unsigned int hooknum)
{
	const struct icmphdr *icmph;
	struct icmphdr _ih;

	/* Not enough header? */
	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
	if (icmph == NULL) {
		icmp_error_log(skb, net, pf, "short packet");
		return -NF_ACCEPT;
	}

	/* See ip_conntrack_proto_tcp.c */
	if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
	    nf_ip_checksum(skb, hooknum, dataoff, 0)) {
		icmp_error_log(skb, net, pf, "bad hw icmp checksum");
		return -NF_ACCEPT;
	}

	/*
	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
	 *
	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently
	 *		  discarded.
	 */
	if (icmph->type > NR_ICMP_TYPES) {
		icmp_error_log(skb, net, pf, "invalid icmp type");
		return -NF_ACCEPT;
	}

	/* Need to track icmp error message? */
	if (icmph->type != ICMP_DEST_UNREACH &&
	    icmph->type != ICMP_SOURCE_QUENCH &&
	    icmph->type != ICMP_TIME_EXCEEDED &&
	    icmph->type != ICMP_PARAMETERPROB &&
	    icmph->type != ICMP_REDIRECT)
		return NF_ACCEPT;

	return icmp_error_message(net, tmpl, skb, hooknum);
}

#if IS_ENABLED(CONFIG_NF_CT_NETLINK)

#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_conntrack.h>

static int icmp_tuple_to_nlattr(struct sk_buff *skb,
				const struct nf_conntrack_tuple *t)
{
	if (nla_put_be16(skb, CTA_PROTO_ICMP_ID, t->src.u.icmp.id) ||
	    nla_put_u8(skb, CTA_PROTO_ICMP_TYPE, t->dst.u.icmp.type) ||
	    nla_put_u8(skb, CTA_PROTO_ICMP_CODE, t->dst.u.icmp.code))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -1;
}

static const struct nla_policy icmp_nla_policy[CTA_PROTO_MAX+1] = {
	[CTA_PROTO_ICMP_TYPE]	= { .type = NLA_U8 },
	[CTA_PROTO_ICMP_CODE]	= { .type = NLA_U8 },
	[CTA_PROTO_ICMP_ID]	= { .type = NLA_U16 },
};

static int icmp_nlattr_to_tuple(struct nlattr *tb[],
				struct nf_conntrack_tuple *tuple)
{
	if (!tb[CTA_PROTO_ICMP_TYPE] ||
	    !tb[CTA_PROTO_ICMP_CODE] ||
	    !tb[CTA_PROTO_ICMP_ID])
		return -EINVAL;

	tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]);
	tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]);
	tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]);

	if (tuple->dst.u.icmp.type >= sizeof(invmap) ||
	    !invmap[tuple->dst.u.icmp.type])
		return -EINVAL;

	return 0;
}

static int icmp_nlattr_tuple_size(void)
{
	return nla_policy_len(icmp_nla_policy, CTA_PROTO_MAX + 1);
}
#endif

#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)

#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_cttimeout.h>

static int icmp_timeout_nlattr_to_obj(struct nlattr *tb[],
				      struct net *net, void *data)
{
	unsigned int *timeout = data;
	struct nf_icmp_net *in = icmp_pernet(net);

	if (tb[CTA_TIMEOUT_ICMP_TIMEOUT]) {
		*timeout =
			ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMP_TIMEOUT])) * HZ;
	} else {
		/* Set default ICMP timeout. */
		*timeout = in->timeout;
	}
	return 0;
}

static int
icmp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
{
	const unsigned int *timeout = data;

	if (nla_put_be32(skb, CTA_TIMEOUT_ICMP_TIMEOUT, htonl(*timeout / HZ)))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -ENOSPC;
}

static const struct nla_policy
icmp_timeout_nla_policy[CTA_TIMEOUT_ICMP_MAX+1] = {
	[CTA_TIMEOUT_ICMP_TIMEOUT]	= { .type = NLA_U32 },
};
#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */

#ifdef CONFIG_SYSCTL
static struct ctl_table icmp_sysctl_table[] = {
	{
		.procname	= "nf_conntrack_icmp_timeout",
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_jiffies,
	},
	{ }
};
#endif /* CONFIG_SYSCTL */

static int icmp_kmemdup_sysctl_table(struct nf_proto_net *pn,
				     struct nf_icmp_net *in)
{
#ifdef CONFIG_SYSCTL
	pn->ctl_table = kmemdup(icmp_sysctl_table,
				sizeof(icmp_sysctl_table),
				GFP_KERNEL);
	if (!pn->ctl_table)
		return -ENOMEM;

	pn->ctl_table[0].data = &in->timeout;
#endif
	return 0;
}

static int icmp_init_net(struct net *net, u_int16_t proto)
{
	struct nf_icmp_net *in = icmp_pernet(net);
	struct nf_proto_net *pn = &in->pn;

	in->timeout = nf_ct_icmp_timeout;

	return icmp_kmemdup_sysctl_table(pn, in);
}

static struct nf_proto_net *icmp_get_net_proto(struct net *net)
{
	return &net->ct.nf_ct_proto.icmp.pn;
}

struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly =
{
	.l3proto		= PF_INET,
	.l4proto		= IPPROTO_ICMP,
	.pkt_to_tuple		= icmp_pkt_to_tuple,
	.invert_tuple		= icmp_invert_tuple,
	.packet			= icmp_packet,
	.get_timeouts		= icmp_get_timeouts,
	.new			= icmp_new,
	.error			= icmp_error,
	.destroy		= NULL,
	.me			= NULL,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
	.tuple_to_nlattr	= icmp_tuple_to_nlattr,
	.nlattr_tuple_size	= icmp_nlattr_tuple_size,
	.nlattr_to_tuple	= icmp_nlattr_to_tuple,
	.nla_policy		= icmp_nla_policy,
#endif
#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
	.ctnl_timeout		= {
		.nlattr_to_obj	= icmp_timeout_nlattr_to_obj,
		.obj_to_nlattr	= icmp_timeout_obj_to_nlattr,
		.nlattr_max	= CTA_TIMEOUT_ICMP_MAX,
		.obj_size	= sizeof(unsigned int),
		.nla_policy	= icmp_timeout_nla_policy,
	},
#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
	.init_net		= icmp_init_net,
	.get_net_proto		= icmp_get_net_proto,
};
Commit	Line	Data
9fb9cbb1 YK	1	/* (C) 1999-2001 Paul `Rusty' Russell
9fb9cbb1 YK	2	* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
f229f6ce	3	* (C) 2006-2010 Patrick McHardy <kaber@trash.net>
9fb9cbb1 YK	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
9fb9cbb1 YK	8	*/
	9
	10	#include <linux/types.h>
9fb9cbb1 YK	11	#include <linux/timer.h>
	12	#include <linux/netfilter.h>
	13	#include <linux/in.h>
	14	#include <linux/icmp.h>
	15	#include <linux/seq_file.h>
	16	#include <net/ip.h>
	17	#include <net/checksum.h>
	18	#include <linux/netfilter_ipv4.h>
	19	#include <net/netfilter/nf_conntrack_tuple.h>
605dcad6	20	#include <net/netfilter/nf_conntrack_l4proto.h>
9fb9cbb1	21	#include <net/netfilter/nf_conntrack_core.h>
5d0aa2cc	22	#include <net/netfilter/nf_conntrack_zones.h>
f01ffbd6	23	#include <net/netfilter/nf_log.h>
9fb9cbb1	24
71320afc	25	static unsigned int nf_ct_icmp_timeout __read_mostly = 30*HZ;
9fb9cbb1	26
4b626b9c G	27	static inline struct nf_icmp_net icmp_pernet(struct net net)
	28	{
	29	return &net->ct.nf_ct_proto.icmp;
	30	}
	31
09f263cd	32	static bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
a31f1adc	33	struct net net, struct nf_conntrack_tuple tuple)
9fb9cbb1	34	{
7cc3864d JE	35	const struct icmphdr *hp;
7cc3864d JE	36	struct icmphdr _hdr;
9fb9cbb1 YK	37
	38	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	39	if (hp == NULL)
09f263cd	40	return false;
9fb9cbb1 YK	41
	42	tuple->dst.u.icmp.type = hp->type;
	43	tuple->src.u.icmp.id = hp->un.echo.id;
	44	tuple->dst.u.icmp.code = hp->code;
	45
09f263cd	46	return true;
9fb9cbb1 YK	47	}
9fb9cbb1 YK	48
c1d10adb PNA	49	/* Add 1; spaces filled with 0. */
	50	static const u_int8_t invmap[] = {
	51	[ICMP_ECHO] = ICMP_ECHOREPLY + 1,
	52	[ICMP_ECHOREPLY] = ICMP_ECHO + 1,
	53	[ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1,
	54	[ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1,
	55	[ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1,
	56	[ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1,
	57	[ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1,
	58	[ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1
	59	};
	60
09f263cd JE	61	static bool icmp_invert_tuple(struct nf_conntrack_tuple *tuple,
09f263cd JE	62	const struct nf_conntrack_tuple *orig)
9fb9cbb1	63	{
3666ed1c JP	64	if (orig->dst.u.icmp.type >= sizeof(invmap) \|\|
3666ed1c JP	65	!invmap[orig->dst.u.icmp.type])
09f263cd	66	return false;
9fb9cbb1 YK	67
	68	tuple->src.u.icmp.id = orig->src.u.icmp.id;
	69	tuple->dst.u.icmp.type = invmap[orig->dst.u.icmp.type] - 1;
	70	tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
09f263cd	71	return true;
9fb9cbb1 YK	72	}
9fb9cbb1 YK	73
2c8503f5 PNA	74	static unsigned int icmp_get_timeouts(struct net net)
2c8503f5 PNA	75	{
4b626b9c	76	return &icmp_pernet(net)->timeout;
2c8503f5 PNA	77	}
2c8503f5 PNA	78
9fb9cbb1 YK	79	/* Returns verdict for packet, or -1 for invalid. */
	80	static int icmp_packet(struct nf_conn *ct,
	81	const struct sk_buff *skb,
	82	unsigned int dataoff,
	83	enum ip_conntrack_info ctinfo,
2c8503f5	84	unsigned int *timeout)
9fb9cbb1	85	{
f87fb666 JK	86	/* Do not immediately delete the connection after the first
	87	successful reply to avoid excessive conntrackd traffic
	88	and also to handle correctly ICMP echo reply duplicates. */
2c8503f5	89	nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
9fb9cbb1 YK	90
	91	return NF_ACCEPT;
	92	}
	93
	94	/* Called when a new connection for this protocol found. */
09f263cd	95	static bool icmp_new(struct nf_conn ct, const struct sk_buff skb,
2c8503f5	96	unsigned int dataoff, unsigned int *timeouts)
9fb9cbb1	97	{
c1d10adb PNA	98	static const u_int8_t valid_new[] = {
	99	[ICMP_ECHO] = 1,
	100	[ICMP_TIMESTAMP] = 1,
	101	[ICMP_INFO_REQUEST] = 1,
	102	[ICMP_ADDRESS] = 1
	103	};
9fb9cbb1	104
3666ed1c JP	105	if (ct->tuplehash[0].tuple.dst.u.icmp.type >= sizeof(valid_new) \|\|
3666ed1c JP	106	!valid_new[ct->tuplehash[0].tuple.dst.u.icmp.type]) {
9fb9cbb1	107	/* Can't create a new ICMP `conn' with this. */
0d53778e	108	pr_debug("icmp: can't create new conn with type %u\n",
c88130bc	109	ct->tuplehash[0].tuple.dst.u.icmp.type);
3c9fba65	110	nf_ct_dump_tuple_ip(&ct->tuplehash[0].tuple);
09f263cd	111	return false;
9fb9cbb1	112	}
09f263cd	113	return true;
9fb9cbb1 YK	114	}
9fb9cbb1 YK	115
9fb9cbb1 YK	116	/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
9fb9cbb1 YK	117	static int
5d0aa2cc	118	icmp_error_message(struct net net, struct nf_conn tmpl, struct sk_buff *skb,
e905a9ed	119	unsigned int hooknum)
9fb9cbb1 YK	120	{
9fb9cbb1 YK	121	struct nf_conntrack_tuple innertuple, origtuple;
7cc3864d JE	122	const struct nf_conntrack_l4proto *innerproto;
7cc3864d JE	123	const struct nf_conntrack_tuple_hash *h;
308ac914	124	const struct nf_conntrack_zone *zone;
11df4b76	125	enum ip_conntrack_info ctinfo;
5e8018fc	126	struct nf_conntrack_zone tmp;
9fb9cbb1	127
44d6e2f2	128	WARN_ON(skb_nfct(skb));
5e8018fc	129	zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
9fb9cbb1	130
e2a3123f YK	131	/* Are they talking about one of our connections? */
	132	if (!nf_ct_get_tuplepr(skb,
	133	skb_network_offset(skb) + ip_hdrlen(skb)
	134	+ sizeof(struct icmphdr),
a31f1adc	135	PF_INET, net, &origtuple)) {
e2a3123f	136	pr_debug("icmp_error_message: failed to get tuple\n");
9fb9cbb1 YK	137	return -NF_ACCEPT;
	138	}
	139
e2361cb9	140	/* rcu_read_lock()ed by nf_hook_thresh */
e2a3123f	141	innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum);
9fb9cbb1	142
e905a9ed YH	143	/* Ordinarily, we'd expect the inverted tupleproto, but it's
	144	been preserved inside the ICMP. */
	145	if (!nf_ct_invert_tuple(&innertuple, &origtuple,
9fb9cbb1	146	&nf_conntrack_l3proto_ipv4, innerproto)) {
0d53778e	147	pr_debug("icmp_error_message: no match\n");
9fb9cbb1 YK	148	return -NF_ACCEPT;
	149	}
	150
11df4b76	151	ctinfo = IP_CT_RELATED;
9fb9cbb1	152
5d0aa2cc	153	h = nf_conntrack_find_get(net, zone, &innertuple);
9fb9cbb1	154	if (!h) {
130e7a83 YK	155	pr_debug("icmp_error_message: no match\n");
130e7a83 YK	156	return -NF_ACCEPT;
9fb9cbb1 YK	157	}
9fb9cbb1 YK	158
130e7a83	159	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
11df4b76	160	ctinfo += IP_CT_IS_REPLY;
130e7a83	161
e905a9ed	162	/* Update skb to refer to this connection */
c74454fa	163	nf_ct_set(skb, nf_ct_tuplehash_to_ctrack(h), ctinfo);
88ed01d1	164	return NF_ACCEPT;
9fb9cbb1 YK	165	}
9fb9cbb1 YK	166
c4f3db15 FW	167	static void icmp_error_log(const struct sk_buff skb, struct net net,
	168	u8 pf, const char *msg)
	169	{
	170	nf_l4proto_log_invalid(skb, net, pf, IPPROTO_ICMP, "%s", msg);
	171	}
	172
9fb9cbb1 YK	173	/* Small and modified version of icmp_rcv */
9fb9cbb1 YK	174	static int
8fea97ec PM	175	icmp_error(struct net net, struct nf_conn tmpl,
8fea97ec PM	176	struct sk_buff *skb, unsigned int dataoff,
11df4b76	177	u8 pf, unsigned int hooknum)
9fb9cbb1	178	{
7cc3864d JE	179	const struct icmphdr *icmph;
7cc3864d JE	180	struct icmphdr _ih;
9fb9cbb1 YK	181
9fb9cbb1 YK	182	/* Not enough header? */
c9bdd4b5	183	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
9fb9cbb1	184	if (icmph == NULL) {
c4f3db15	185	icmp_error_log(skb, net, pf, "short packet");
9fb9cbb1 YK	186	return -NF_ACCEPT;
	187	}
	188
	189	/* See ip_conntrack_proto_tcp.c */
c04d0552	190	if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
96f6bf82	191	nf_ip_checksum(skb, hooknum, dataoff, 0)) {
c4f3db15	192	icmp_error_log(skb, net, pf, "bad hw icmp checksum");
9fb9cbb1	193	return -NF_ACCEPT;
9fb9cbb1 YK	194	}
9fb9cbb1 YK	195
9fb9cbb1 YK	196	/*
	197	* 18 is the highest 'known' ICMP type. Anything else is a mystery
	198	*
	199	* RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently
	200	* discarded.
	201	*/
	202	if (icmph->type > NR_ICMP_TYPES) {
c4f3db15	203	icmp_error_log(skb, net, pf, "invalid icmp type");
9fb9cbb1 YK	204	return -NF_ACCEPT;
	205	}
	206
	207	/* Need to track icmp error message? */
3666ed1c JP	208	if (icmph->type != ICMP_DEST_UNREACH &&
	209	icmph->type != ICMP_SOURCE_QUENCH &&
	210	icmph->type != ICMP_TIME_EXCEEDED &&
	211	icmph->type != ICMP_PARAMETERPROB &&
	212	icmph->type != ICMP_REDIRECT)
9fb9cbb1 YK	213	return NF_ACCEPT;
9fb9cbb1 YK	214
11df4b76	215	return icmp_error_message(net, tmpl, skb, hooknum);
9fb9cbb1 YK	216	}
9fb9cbb1 YK	217
24de3d37	218	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
c1d10adb PNA	219
	220	#include <linux/netfilter/nfnetlink.h>
	221	#include <linux/netfilter/nfnetlink_conntrack.h>
	222
fdf70832	223	static int icmp_tuple_to_nlattr(struct sk_buff *skb,
c1d10adb PNA	224	const struct nf_conntrack_tuple *t)
c1d10adb PNA	225	{
d317e4f6 DM	226	if (nla_put_be16(skb, CTA_PROTO_ICMP_ID, t->src.u.icmp.id) \|\|
	227	nla_put_u8(skb, CTA_PROTO_ICMP_TYPE, t->dst.u.icmp.type) \|\|
	228	nla_put_u8(skb, CTA_PROTO_ICMP_CODE, t->dst.u.icmp.code))
	229	goto nla_put_failure;
c1d10adb PNA	230	return 0;
c1d10adb PNA	231
df6fb868	232	nla_put_failure:
c1d10adb PNA	233	return -1;
	234	}
	235
f73e924c PM	236	static const struct nla_policy icmp_nla_policy[CTA_PROTO_MAX+1] = {
	237	[CTA_PROTO_ICMP_TYPE] = { .type = NLA_U8 },
	238	[CTA_PROTO_ICMP_CODE] = { .type = NLA_U8 },
	239	[CTA_PROTO_ICMP_ID] = { .type = NLA_U16 },
c1d10adb PNA	240	};
c1d10adb PNA	241
fdf70832	242	static int icmp_nlattr_to_tuple(struct nlattr *tb[],
c1d10adb PNA	243	struct nf_conntrack_tuple *tuple)
c1d10adb PNA	244	{
3666ed1c JP	245	if (!tb[CTA_PROTO_ICMP_TYPE] \|\|
	246	!tb[CTA_PROTO_ICMP_CODE] \|\|
	247	!tb[CTA_PROTO_ICMP_ID])
c1d10adb PNA	248	return -EINVAL;
c1d10adb PNA	249
77236b6e PM	250	tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]);
	251	tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]);
	252	tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]);
c1d10adb	253
3666ed1c JP	254	if (tuple->dst.u.icmp.type >= sizeof(invmap) \|\|
3666ed1c JP	255	!invmap[tuple->dst.u.icmp.type])
c1d10adb PNA	256	return -EINVAL;
	257
	258	return 0;
	259	}
a400c30e HE	260
	261	static int icmp_nlattr_tuple_size(void)
	262	{
	263	return nla_policy_len(icmp_nla_policy, CTA_PROTO_MAX + 1);
	264	}
c1d10adb PNA	265	#endif
c1d10adb PNA	266
50978462 PNA	267	#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
	268
	269	#include <linux/netfilter/nfnetlink.h>
	270	#include <linux/netfilter/nfnetlink_cttimeout.h>
	271
8264deb8 G	272	static int icmp_timeout_nlattr_to_obj(struct nlattr *tb[],
8264deb8 G	273	struct net net, void data)
50978462 PNA	274	{
50978462 PNA	275	unsigned int *timeout = data;
8264deb8	276	struct nf_icmp_net *in = icmp_pernet(net);
50978462 PNA	277
	278	if (tb[CTA_TIMEOUT_ICMP_TIMEOUT]) {
	279	*timeout =
	280	ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMP_TIMEOUT])) * HZ;
	281	} else {
	282	/* Set default ICMP timeout. */
8264deb8	283	*timeout = in->timeout;
50978462 PNA	284	}
	285	return 0;
	286	}
	287
	288	static int
	289	icmp_timeout_obj_to_nlattr(struct sk_buff skb, const void data)
	290	{
	291	const unsigned int *timeout = data;
	292
d317e4f6 DM	293	if (nla_put_be32(skb, CTA_TIMEOUT_ICMP_TIMEOUT, htonl(*timeout / HZ)))
d317e4f6 DM	294	goto nla_put_failure;
50978462 PNA	295	return 0;
	296
	297	nla_put_failure:
	298	return -ENOSPC;
	299	}
	300
	301	static const struct nla_policy
	302	icmp_timeout_nla_policy[CTA_TIMEOUT_ICMP_MAX+1] = {
	303	[CTA_TIMEOUT_ICMP_TIMEOUT] = { .type = NLA_U32 },
	304	};
	305	#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
	306
933a41e7	307	#ifdef CONFIG_SYSCTL
933a41e7 PM	308	static struct ctl_table icmp_sysctl_table[] = {
933a41e7 PM	309	{
933a41e7	310	.procname = "nf_conntrack_icmp_timeout",
933a41e7 PM	311	.maxlen = sizeof(unsigned int),
933a41e7 PM	312	.mode = 0644,
6d9f239a	313	.proc_handler = proc_dointvec_jiffies,
933a41e7	314	},
f8572d8f	315	{ }
933a41e7 PM	316	};
	317	#endif /* CONFIG_SYSCTL */
	318
a9082b45 G	319	static int icmp_kmemdup_sysctl_table(struct nf_proto_net *pn,
a9082b45 G	320	struct nf_icmp_net *in)
4b626b9c	321	{
4b626b9c G	322	#ifdef CONFIG_SYSCTL
	323	pn->ctl_table = kmemdup(icmp_sysctl_table,
	324	sizeof(icmp_sysctl_table),
	325	GFP_KERNEL);
	326	if (!pn->ctl_table)
	327	return -ENOMEM;
a9082b45	328
4b626b9c	329	pn->ctl_table[0].data = &in->timeout;
a9082b45 G	330	#endif
	331	return 0;
	332	}
	333
a9082b45 G	334	static int icmp_init_net(struct net *net, u_int16_t proto)
a9082b45 G	335	{
a9082b45 G	336	struct nf_icmp_net *in = icmp_pernet(net);
	337	struct nf_proto_net *pn = &in->pn;
	338
	339	in->timeout = nf_ct_icmp_timeout;
	340
adf05168	341	return icmp_kmemdup_sysctl_table(pn, in);
a9082b45 G	342	}
a9082b45 G	343
08911475 PNA	344	static struct nf_proto_net icmp_get_net_proto(struct net net)
	345	{
	346	return &net->ct.nf_ct_proto.icmp.pn;
	347	}
	348
61075af5	349	struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly =
9fb9cbb1	350	{
9fb9cbb1	351	.l3proto = PF_INET,
605dcad6	352	.l4proto = IPPROTO_ICMP,
9fb9cbb1 YK	353	.pkt_to_tuple = icmp_pkt_to_tuple,
9fb9cbb1 YK	354	.invert_tuple = icmp_invert_tuple,
9fb9cbb1	355	.packet = icmp_packet,
2c8503f5	356	.get_timeouts = icmp_get_timeouts,
9fb9cbb1 YK	357	.new = icmp_new,
	358	.error = icmp_error,
	359	.destroy = NULL,
c1d10adb	360	.me = NULL,
24de3d37	361	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
fdf70832	362	.tuple_to_nlattr = icmp_tuple_to_nlattr,
a400c30e	363	.nlattr_tuple_size = icmp_nlattr_tuple_size,
fdf70832	364	.nlattr_to_tuple = icmp_nlattr_to_tuple,
f73e924c	365	.nla_policy = icmp_nla_policy,
c1d10adb	366	#endif
50978462 PNA	367	#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
	368	.ctnl_timeout = {
	369	.nlattr_to_obj = icmp_timeout_nlattr_to_obj,
	370	.obj_to_nlattr = icmp_timeout_obj_to_nlattr,
	371	.nlattr_max = CTA_TIMEOUT_ICMP_MAX,
	372	.obj_size = sizeof(unsigned int),
	373	.nla_policy = icmp_timeout_nla_policy,
	374	},
	375	#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
4b626b9c	376	.init_net = icmp_init_net,
08911475	377	.get_net_proto = icmp_get_net_proto,
9fb9cbb1	378	};