[mirror_ubuntu-disco-kernel.git] / net / 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_timeout.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/nf_log.h>

static const unsigned int nf_ct_icmp_timeout = 30*HZ;

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;
}

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

	if (state->pf != NFPROTO_IPV4)
		return -NF_ACCEPT;

	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 -NF_ACCEPT;
	}

	if (!timeout)
		timeout = &nf_icmp_pernet(nf_ct_net(ct))->timeout;

	nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
	return NF_ACCEPT;
}

/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
static int
icmp_error_message(struct nf_conn *tmpl, struct sk_buff *skb,
		   const struct nf_hook_state *state)
{
	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, state->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(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, innerproto)) {
		pr_debug("icmp_error_message: no match\n");
		return -NF_ACCEPT;
	}

	ctinfo = IP_CT_RELATED;

	h = nf_conntrack_find_get(state->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,
			   const struct nf_hook_state *state,
			   const char *msg)
{
	nf_l4proto_log_invalid(skb, state->net, state->pf,
			       IPPROTO_ICMP, "%s", msg);
}

/* Small and modified version of icmp_rcv */
int nf_conntrack_icmpv4_error(struct nf_conn *tmpl,
			      struct sk_buff *skb, unsigned int dataoff,
			      const struct nf_hook_state *state)
{
	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, state, "short packet");
		return -NF_ACCEPT;
	}

	/* See ip_conntrack_proto_tcp.c */
	if (state->net->ct.sysctl_checksum &&
	    state->hook == NF_INET_PRE_ROUTING &&
	    nf_ip_checksum(skb, state->hook, dataoff, 0)) {
		icmp_error_log(skb, state, "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, state, "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(tmpl, skb, state);
}

#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 unsigned int icmp_nlattr_tuple_size(void)
{
	static unsigned int size __read_mostly;

	if (!size)
		size = nla_policy_len(icmp_nla_policy, CTA_PROTO_MAX + 1);

	return size;
}
#endif

#ifdef CONFIG_NF_CONNTRACK_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 = nf_icmp_pernet(net);

	if (tb[CTA_TIMEOUT_ICMP_TIMEOUT]) {
		if (!timeout)
			timeout = &in->timeout;
		*timeout =
			ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMP_TIMEOUT])) * HZ;
	} else if (timeout) {
		/* 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_CONNTRACK_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)
{
	struct nf_icmp_net *in = nf_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;
}

const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp =
{
	.l4proto		= IPPROTO_ICMP,
	.pkt_to_tuple		= icmp_pkt_to_tuple,
	.invert_tuple		= icmp_invert_tuple,
	.packet			= icmp_packet,
	.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
#ifdef CONFIG_NF_CONNTRACK_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_CONNTRACK_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>
c779e849	22	#include <net/netfilter/nf_conntrack_timeout.h>
5d0aa2cc	23	#include <net/netfilter/nf_conntrack_zones.h>
f01ffbd6	24	#include <net/netfilter/nf_log.h>
9fb9cbb1	25
2c9e8637	26	static const unsigned int nf_ct_icmp_timeout = 30*HZ;
9fb9cbb1	27
09f263cd	28	static bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
a31f1adc	29	struct net net, struct nf_conntrack_tuple tuple)
9fb9cbb1	30	{
7cc3864d JE	31	const struct icmphdr *hp;
7cc3864d JE	32	struct icmphdr _hdr;
9fb9cbb1 YK	33
	34	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	35	if (hp == NULL)
09f263cd	36	return false;
9fb9cbb1 YK	37
	38	tuple->dst.u.icmp.type = hp->type;
	39	tuple->src.u.icmp.id = hp->un.echo.id;
	40	tuple->dst.u.icmp.code = hp->code;
	41
09f263cd	42	return true;
9fb9cbb1 YK	43	}
9fb9cbb1 YK	44
c1d10adb PNA	45	/* Add 1; spaces filled with 0. */
	46	static const u_int8_t invmap[] = {
	47	[ICMP_ECHO] = ICMP_ECHOREPLY + 1,
	48	[ICMP_ECHOREPLY] = ICMP_ECHO + 1,
	49	[ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1,
	50	[ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1,
	51	[ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1,
	52	[ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1,
	53	[ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1,
	54	[ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1
	55	};
	56
09f263cd JE	57	static bool icmp_invert_tuple(struct nf_conntrack_tuple *tuple,
09f263cd JE	58	const struct nf_conntrack_tuple *orig)
9fb9cbb1	59	{
3666ed1c JP	60	if (orig->dst.u.icmp.type >= sizeof(invmap) \|\|
3666ed1c JP	61	!invmap[orig->dst.u.icmp.type])
09f263cd	62	return false;
9fb9cbb1 YK	63
	64	tuple->src.u.icmp.id = orig->src.u.icmp.id;
	65	tuple->dst.u.icmp.type = invmap[orig->dst.u.icmp.type] - 1;
	66	tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
09f263cd	67	return true;
9fb9cbb1 YK	68	}
9fb9cbb1 YK	69
9fb9cbb1 YK	70	/* Returns verdict for packet, or -1 for invalid. */
9fb9cbb1 YK	71	static int icmp_packet(struct nf_conn *ct,
83d213fd	72	struct sk_buff *skb,
9fb9cbb1	73	unsigned int dataoff,
93e66024 FW	74	enum ip_conntrack_info ctinfo,
93e66024 FW	75	const struct nf_hook_state *state)
9fb9cbb1	76	{
f87fb666 JK	77	/* Do not immediately delete the connection after the first
	78	successful reply to avoid excessive conntrackd traffic
	79	and also to handle correctly ICMP echo reply duplicates. */
c779e849	80	unsigned int *timeout = nf_ct_timeout_lookup(ct);
c1d10adb PNA	81	static const u_int8_t valid_new[] = {
	82	[ICMP_ECHO] = 1,
	83	[ICMP_TIMESTAMP] = 1,
	84	[ICMP_INFO_REQUEST] = 1,
	85	[ICMP_ADDRESS] = 1
	86	};
9fb9cbb1	87
dd2934a9 FW	88	if (state->pf != NFPROTO_IPV4)
	89	return -NF_ACCEPT;
	90
3666ed1c JP	91	if (ct->tuplehash[0].tuple.dst.u.icmp.type >= sizeof(valid_new) \|\|
3666ed1c JP	92	!valid_new[ct->tuplehash[0].tuple.dst.u.icmp.type]) {
9fb9cbb1	93	/* Can't create a new ICMP `conn' with this. */
0d53778e	94	pr_debug("icmp: can't create new conn with type %u\n",
c88130bc	95	ct->tuplehash[0].tuple.dst.u.icmp.type);
3c9fba65	96	nf_ct_dump_tuple_ip(&ct->tuplehash[0].tuple);
9976fc6e	97	return -NF_ACCEPT;
9fb9cbb1	98	}
9976fc6e FW	99
9976fc6e FW	100	if (!timeout)
a95a7774	101	timeout = &nf_icmp_pernet(nf_ct_net(ct))->timeout;
9976fc6e FW	102
	103	nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
	104	return NF_ACCEPT;
9fb9cbb1 YK	105	}
9fb9cbb1 YK	106
9fb9cbb1 YK	107	/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
9fb9cbb1 YK	108	static int
93e66024 FW	109	icmp_error_message(struct nf_conn tmpl, struct sk_buff skb,
93e66024 FW	110	const struct nf_hook_state *state)
9fb9cbb1 YK	111	{
9fb9cbb1 YK	112	struct nf_conntrack_tuple innertuple, origtuple;
7cc3864d JE	113	const struct nf_conntrack_l4proto *innerproto;
7cc3864d JE	114	const struct nf_conntrack_tuple_hash *h;
308ac914	115	const struct nf_conntrack_zone *zone;
11df4b76	116	enum ip_conntrack_info ctinfo;
5e8018fc	117	struct nf_conntrack_zone tmp;
9fb9cbb1	118
44d6e2f2	119	WARN_ON(skb_nfct(skb));
5e8018fc	120	zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
9fb9cbb1	121
e2a3123f YK	122	/* Are they talking about one of our connections? */
	123	if (!nf_ct_get_tuplepr(skb,
	124	skb_network_offset(skb) + ip_hdrlen(skb)
	125	+ sizeof(struct icmphdr),
93e66024	126	PF_INET, state->net, &origtuple)) {
e2a3123f	127	pr_debug("icmp_error_message: failed to get tuple\n");
9fb9cbb1 YK	128	return -NF_ACCEPT;
	129	}
	130
e2361cb9	131	/* rcu_read_lock()ed by nf_hook_thresh */
dd2934a9	132	innerproto = __nf_ct_l4proto_find(origtuple.dst.protonum);
9fb9cbb1	133
e905a9ed YH	134	/* Ordinarily, we'd expect the inverted tupleproto, but it's
e905a9ed YH	135	been preserved inside the ICMP. */
d1b6fe94	136	if (!nf_ct_invert_tuple(&innertuple, &origtuple, innerproto)) {
0d53778e	137	pr_debug("icmp_error_message: no match\n");
9fb9cbb1 YK	138	return -NF_ACCEPT;
	139	}
	140
11df4b76	141	ctinfo = IP_CT_RELATED;
9fb9cbb1	142
93e66024	143	h = nf_conntrack_find_get(state->net, zone, &innertuple);
9fb9cbb1	144	if (!h) {
130e7a83 YK	145	pr_debug("icmp_error_message: no match\n");
130e7a83 YK	146	return -NF_ACCEPT;
9fb9cbb1 YK	147	}
9fb9cbb1 YK	148
130e7a83	149	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
11df4b76	150	ctinfo += IP_CT_IS_REPLY;
130e7a83	151
e905a9ed	152	/* Update skb to refer to this connection */
c74454fa	153	nf_ct_set(skb, nf_ct_tuplehash_to_ctrack(h), ctinfo);
88ed01d1	154	return NF_ACCEPT;
9fb9cbb1 YK	155	}
9fb9cbb1 YK	156
93e66024 FW	157	static void icmp_error_log(const struct sk_buff *skb,
	158	const struct nf_hook_state *state,
	159	const char *msg)
c4f3db15	160	{
93e66024 FW	161	nf_l4proto_log_invalid(skb, state->net, state->pf,
93e66024 FW	162	IPPROTO_ICMP, "%s", msg);
c4f3db15 FW	163	}
c4f3db15 FW	164
9fb9cbb1	165	/* Small and modified version of icmp_rcv */
6fe78fa4 FW	166	int nf_conntrack_icmpv4_error(struct nf_conn *tmpl,
	167	struct sk_buff *skb, unsigned int dataoff,
	168	const struct nf_hook_state *state)
9fb9cbb1	169	{
7cc3864d JE	170	const struct icmphdr *icmph;
7cc3864d JE	171	struct icmphdr _ih;
9fb9cbb1 YK	172
9fb9cbb1 YK	173	/* Not enough header? */
c9bdd4b5	174	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
9fb9cbb1	175	if (icmph == NULL) {
93e66024	176	icmp_error_log(skb, state, "short packet");
9fb9cbb1 YK	177	return -NF_ACCEPT;
	178	}
	179
	180	/* See ip_conntrack_proto_tcp.c */
93e66024 FW	181	if (state->net->ct.sysctl_checksum &&
	182	state->hook == NF_INET_PRE_ROUTING &&
	183	nf_ip_checksum(skb, state->hook, dataoff, 0)) {
	184	icmp_error_log(skb, state, "bad hw icmp checksum");
9fb9cbb1	185	return -NF_ACCEPT;
9fb9cbb1 YK	186	}
9fb9cbb1 YK	187
9fb9cbb1 YK	188	/*
	189	* 18 is the highest 'known' ICMP type. Anything else is a mystery
	190	*
	191	* RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently
	192	* discarded.
	193	*/
	194	if (icmph->type > NR_ICMP_TYPES) {
93e66024	195	icmp_error_log(skb, state, "invalid icmp type");
9fb9cbb1 YK	196	return -NF_ACCEPT;
	197	}
	198
	199	/* Need to track icmp error message? */
3666ed1c JP	200	if (icmph->type != ICMP_DEST_UNREACH &&
	201	icmph->type != ICMP_SOURCE_QUENCH &&
	202	icmph->type != ICMP_TIME_EXCEEDED &&
	203	icmph->type != ICMP_PARAMETERPROB &&
	204	icmph->type != ICMP_REDIRECT)
9fb9cbb1 YK	205	return NF_ACCEPT;
9fb9cbb1 YK	206
93e66024	207	return icmp_error_message(tmpl, skb, state);
9fb9cbb1 YK	208	}
9fb9cbb1 YK	209
24de3d37	210	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
c1d10adb PNA	211
	212	#include <linux/netfilter/nfnetlink.h>
	213	#include <linux/netfilter/nfnetlink_conntrack.h>
	214
fdf70832	215	static int icmp_tuple_to_nlattr(struct sk_buff *skb,
c1d10adb PNA	216	const struct nf_conntrack_tuple *t)
c1d10adb PNA	217	{
d317e4f6 DM	218	if (nla_put_be16(skb, CTA_PROTO_ICMP_ID, t->src.u.icmp.id) \|\|
	219	nla_put_u8(skb, CTA_PROTO_ICMP_TYPE, t->dst.u.icmp.type) \|\|
	220	nla_put_u8(skb, CTA_PROTO_ICMP_CODE, t->dst.u.icmp.code))
	221	goto nla_put_failure;
c1d10adb PNA	222	return 0;
c1d10adb PNA	223
df6fb868	224	nla_put_failure:
c1d10adb PNA	225	return -1;
	226	}
	227
f73e924c PM	228	static const struct nla_policy icmp_nla_policy[CTA_PROTO_MAX+1] = {
	229	[CTA_PROTO_ICMP_TYPE] = { .type = NLA_U8 },
	230	[CTA_PROTO_ICMP_CODE] = { .type = NLA_U8 },
	231	[CTA_PROTO_ICMP_ID] = { .type = NLA_U16 },
c1d10adb PNA	232	};
c1d10adb PNA	233
fdf70832	234	static int icmp_nlattr_to_tuple(struct nlattr *tb[],
c1d10adb PNA	235	struct nf_conntrack_tuple *tuple)
c1d10adb PNA	236	{
3666ed1c JP	237	if (!tb[CTA_PROTO_ICMP_TYPE] \|\|
	238	!tb[CTA_PROTO_ICMP_CODE] \|\|
	239	!tb[CTA_PROTO_ICMP_ID])
c1d10adb PNA	240	return -EINVAL;
c1d10adb PNA	241
77236b6e PM	242	tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]);
	243	tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]);
	244	tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]);
c1d10adb	245
3666ed1c JP	246	if (tuple->dst.u.icmp.type >= sizeof(invmap) \|\|
3666ed1c JP	247	!invmap[tuple->dst.u.icmp.type])
c1d10adb PNA	248	return -EINVAL;
	249
	250	return 0;
	251	}
a400c30e	252
5caaed15	253	static unsigned int icmp_nlattr_tuple_size(void)
a400c30e	254	{
5caaed15 FW	255	static unsigned int size __read_mostly;
	256
	257	if (!size)
	258	size = nla_policy_len(icmp_nla_policy, CTA_PROTO_MAX + 1);
	259
	260	return size;
a400c30e	261	}
c1d10adb PNA	262	#endif
c1d10adb PNA	263
a874752a	264	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
50978462 PNA	265
	266	#include <linux/netfilter/nfnetlink.h>
	267	#include <linux/netfilter/nfnetlink_cttimeout.h>
	268
8264deb8 G	269	static int icmp_timeout_nlattr_to_obj(struct nlattr *tb[],
8264deb8 G	270	struct net net, void data)
50978462 PNA	271	{
50978462 PNA	272	unsigned int *timeout = data;
a95a7774	273	struct nf_icmp_net *in = nf_icmp_pernet(net);
50978462 PNA	274
50978462 PNA	275	if (tb[CTA_TIMEOUT_ICMP_TIMEOUT]) {
c779e849 FW	276	if (!timeout)
c779e849 FW	277	timeout = &in->timeout;
50978462 PNA	278	*timeout =
50978462 PNA	279	ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMP_TIMEOUT])) * HZ;
c779e849	280	} else if (timeout) {
50978462	281	/* Set default ICMP timeout. */
8264deb8	282	*timeout = in->timeout;
50978462 PNA	283	}
	284	return 0;
	285	}
	286
	287	static int
	288	icmp_timeout_obj_to_nlattr(struct sk_buff skb, const void data)
	289	{
	290	const unsigned int *timeout = data;
	291
d317e4f6 DM	292	if (nla_put_be32(skb, CTA_TIMEOUT_ICMP_TIMEOUT, htonl(*timeout / HZ)))
d317e4f6 DM	293	goto nla_put_failure;
50978462 PNA	294	return 0;
	295
	296	nla_put_failure:
	297	return -ENOSPC;
	298	}
	299
	300	static const struct nla_policy
	301	icmp_timeout_nla_policy[CTA_TIMEOUT_ICMP_MAX+1] = {
	302	[CTA_TIMEOUT_ICMP_TIMEOUT] = { .type = NLA_U32 },
	303	};
a874752a	304	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
50978462	305
933a41e7	306	#ifdef CONFIG_SYSCTL
933a41e7 PM	307	static struct ctl_table icmp_sysctl_table[] = {
933a41e7 PM	308	{
933a41e7	309	.procname = "nf_conntrack_icmp_timeout",
933a41e7 PM	310	.maxlen = sizeof(unsigned int),
933a41e7 PM	311	.mode = 0644,
6d9f239a	312	.proc_handler = proc_dointvec_jiffies,
933a41e7	313	},
f8572d8f	314	{ }
933a41e7 PM	315	};
	316	#endif /* CONFIG_SYSCTL */
	317
a9082b45 G	318	static int icmp_kmemdup_sysctl_table(struct nf_proto_net *pn,
a9082b45 G	319	struct nf_icmp_net *in)
4b626b9c	320	{
4b626b9c G	321	#ifdef CONFIG_SYSCTL
	322	pn->ctl_table = kmemdup(icmp_sysctl_table,
	323	sizeof(icmp_sysctl_table),
	324	GFP_KERNEL);
	325	if (!pn->ctl_table)
	326	return -ENOMEM;
a9082b45	327
4b626b9c	328	pn->ctl_table[0].data = &in->timeout;
a9082b45 G	329	#endif
	330	return 0;
	331	}
	332
ca2ca6e1	333	static int icmp_init_net(struct net *net)
a9082b45	334	{
a95a7774	335	struct nf_icmp_net *in = nf_icmp_pernet(net);
a9082b45 G	336	struct nf_proto_net *pn = &in->pn;
	337
	338	in->timeout = nf_ct_icmp_timeout;
	339
adf05168	340	return icmp_kmemdup_sysctl_table(pn, in);
a9082b45 G	341	}
a9082b45 G	342
08911475 PNA	343	static struct nf_proto_net icmp_get_net_proto(struct net net)
	344	{
	345	return &net->ct.nf_ct_proto.icmp.pn;
	346	}
	347
9dae47ab	348	const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp =
9fb9cbb1	349	{
605dcad6	350	.l4proto = IPPROTO_ICMP,
9fb9cbb1 YK	351	.pkt_to_tuple = icmp_pkt_to_tuple,
9fb9cbb1 YK	352	.invert_tuple = icmp_invert_tuple,
9fb9cbb1	353	.packet = icmp_packet,
9fb9cbb1	354	.destroy = NULL,
c1d10adb	355	.me = NULL,
24de3d37	356	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
fdf70832	357	.tuple_to_nlattr = icmp_tuple_to_nlattr,
a400c30e	358	.nlattr_tuple_size = icmp_nlattr_tuple_size,
fdf70832	359	.nlattr_to_tuple = icmp_nlattr_to_tuple,
f73e924c	360	.nla_policy = icmp_nla_policy,
c1d10adb	361	#endif
a874752a	362	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
50978462 PNA	363	.ctnl_timeout = {
	364	.nlattr_to_obj = icmp_timeout_nlattr_to_obj,
	365	.obj_to_nlattr = icmp_timeout_obj_to_nlattr,
	366	.nlattr_max = CTA_TIMEOUT_ICMP_MAX,
	367	.obj_size = sizeof(unsigned int),
	368	.nla_policy = icmp_timeout_nla_policy,
	369	},
a874752a	370	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
4b626b9c	371	.init_net = icmp_init_net,
08911475	372	.get_net_proto = icmp_get_net_proto,
9fb9cbb1	373	};