1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
3 * (C) 2006-2010 Patrick McHardy <kaber@trash.net>
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.
10 #include <linux/types.h>
11 #include <linux/timer.h>
12 #include <linux/netfilter.h>
14 #include <linux/icmp.h>
15 #include <linux/seq_file.h>
17 #include <net/checksum.h>
18 #include <linux/netfilter_ipv4.h>
19 #include <net/netfilter/nf_conntrack_tuple.h>
20 #include <net/netfilter/nf_conntrack_l4proto.h>
21 #include <net/netfilter/nf_conntrack_core.h>
22 #include <net/netfilter/nf_conntrack_zones.h>
23 #include <net/netfilter/nf_log.h>
25 static unsigned int nf_ct_icmp_timeout __read_mostly
= 30*HZ
;
27 static inline struct nf_icmp_net
*icmp_pernet(struct net
*net
)
29 return &net
->ct
.nf_ct_proto
.icmp
;
32 static bool icmp_pkt_to_tuple(const struct sk_buff
*skb
, unsigned int dataoff
,
33 struct nf_conntrack_tuple
*tuple
)
35 const struct icmphdr
*hp
;
38 hp
= skb_header_pointer(skb
, dataoff
, sizeof(_hdr
), &_hdr
);
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
;
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
61 static bool icmp_invert_tuple(struct nf_conntrack_tuple
*tuple
,
62 const struct nf_conntrack_tuple
*orig
)
64 if (orig
->dst
.u
.icmp
.type
>= sizeof(invmap
) ||
65 !invmap
[orig
->dst
.u
.icmp
.type
])
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
;
74 /* Print out the per-protocol part of the tuple. */
75 static void icmp_print_tuple(struct seq_file
*s
,
76 const struct nf_conntrack_tuple
*tuple
)
78 seq_printf(s
, "type=%u code=%u id=%u ",
79 tuple
->dst
.u
.icmp
.type
,
80 tuple
->dst
.u
.icmp
.code
,
81 ntohs(tuple
->src
.u
.icmp
.id
));
84 static unsigned int *icmp_get_timeouts(struct net
*net
)
86 return &icmp_pernet(net
)->timeout
;
89 /* Returns verdict for packet, or -1 for invalid. */
90 static int icmp_packet(struct nf_conn
*ct
,
91 const struct sk_buff
*skb
,
93 enum ip_conntrack_info ctinfo
,
96 unsigned int *timeout
)
98 /* Do not immediately delete the connection after the first
99 successful reply to avoid excessive conntrackd traffic
100 and also to handle correctly ICMP echo reply duplicates. */
101 nf_ct_refresh_acct(ct
, ctinfo
, skb
, *timeout
);
106 /* Called when a new connection for this protocol found. */
107 static bool icmp_new(struct nf_conn
*ct
, const struct sk_buff
*skb
,
108 unsigned int dataoff
, unsigned int *timeouts
)
110 static const u_int8_t valid_new
[] = {
112 [ICMP_TIMESTAMP
] = 1,
113 [ICMP_INFO_REQUEST
] = 1,
117 if (ct
->tuplehash
[0].tuple
.dst
.u
.icmp
.type
>= sizeof(valid_new
) ||
118 !valid_new
[ct
->tuplehash
[0].tuple
.dst
.u
.icmp
.type
]) {
119 /* Can't create a new ICMP `conn' with this. */
120 pr_debug("icmp: can't create new conn with type %u\n",
121 ct
->tuplehash
[0].tuple
.dst
.u
.icmp
.type
);
122 nf_ct_dump_tuple_ip(&ct
->tuplehash
[0].tuple
);
128 /* Returns conntrack if it dealt with ICMP, and filled in skb fields */
130 icmp_error_message(struct net
*net
, struct nf_conn
*tmpl
, struct sk_buff
*skb
,
131 enum ip_conntrack_info
*ctinfo
,
132 unsigned int hooknum
)
134 struct nf_conntrack_tuple innertuple
, origtuple
;
135 const struct nf_conntrack_l4proto
*innerproto
;
136 const struct nf_conntrack_tuple_hash
*h
;
137 u16 zone
= tmpl
? nf_ct_zone(tmpl
) : NF_CT_DEFAULT_ZONE
;
139 NF_CT_ASSERT(skb
->nfct
== NULL
);
141 /* Are they talking about one of our connections? */
142 if (!nf_ct_get_tuplepr(skb
,
143 skb_network_offset(skb
) + ip_hdrlen(skb
)
144 + sizeof(struct icmphdr
),
145 PF_INET
, &origtuple
)) {
146 pr_debug("icmp_error_message: failed to get tuple\n");
150 /* rcu_read_lock()ed by nf_hook_slow */
151 innerproto
= __nf_ct_l4proto_find(PF_INET
, origtuple
.dst
.protonum
);
153 /* Ordinarily, we'd expect the inverted tupleproto, but it's
154 been preserved inside the ICMP. */
155 if (!nf_ct_invert_tuple(&innertuple
, &origtuple
,
156 &nf_conntrack_l3proto_ipv4
, innerproto
)) {
157 pr_debug("icmp_error_message: no match\n");
161 *ctinfo
= IP_CT_RELATED
;
163 h
= nf_conntrack_find_get(net
, zone
, &innertuple
);
165 pr_debug("icmp_error_message: no match\n");
169 if (NF_CT_DIRECTION(h
) == IP_CT_DIR_REPLY
)
170 *ctinfo
+= IP_CT_IS_REPLY
;
172 /* Update skb to refer to this connection */
173 skb
->nfct
= &nf_ct_tuplehash_to_ctrack(h
)->ct_general
;
174 skb
->nfctinfo
= *ctinfo
;
178 /* Small and modified version of icmp_rcv */
180 icmp_error(struct net
*net
, struct nf_conn
*tmpl
,
181 struct sk_buff
*skb
, unsigned int dataoff
,
182 enum ip_conntrack_info
*ctinfo
, u_int8_t pf
, unsigned int hooknum
)
184 const struct icmphdr
*icmph
;
187 /* Not enough header? */
188 icmph
= skb_header_pointer(skb
, ip_hdrlen(skb
), sizeof(_ih
), &_ih
);
190 if (LOG_INVALID(net
, IPPROTO_ICMP
))
191 nf_log_packet(net
, PF_INET
, 0, skb
, NULL
, NULL
,
192 NULL
, "nf_ct_icmp: short packet ");
196 /* See ip_conntrack_proto_tcp.c */
197 if (net
->ct
.sysctl_checksum
&& hooknum
== NF_INET_PRE_ROUTING
&&
198 nf_ip_checksum(skb
, hooknum
, dataoff
, 0)) {
199 if (LOG_INVALID(net
, IPPROTO_ICMP
))
200 nf_log_packet(net
, PF_INET
, 0, skb
, NULL
, NULL
, NULL
,
201 "nf_ct_icmp: bad HW ICMP checksum ");
206 * 18 is the highest 'known' ICMP type. Anything else is a mystery
208 * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently
211 if (icmph
->type
> NR_ICMP_TYPES
) {
212 if (LOG_INVALID(net
, IPPROTO_ICMP
))
213 nf_log_packet(net
, PF_INET
, 0, skb
, NULL
, NULL
, NULL
,
214 "nf_ct_icmp: invalid ICMP type ");
218 /* Need to track icmp error message? */
219 if (icmph
->type
!= ICMP_DEST_UNREACH
&&
220 icmph
->type
!= ICMP_SOURCE_QUENCH
&&
221 icmph
->type
!= ICMP_TIME_EXCEEDED
&&
222 icmph
->type
!= ICMP_PARAMETERPROB
&&
223 icmph
->type
!= ICMP_REDIRECT
)
226 return icmp_error_message(net
, tmpl
, skb
, ctinfo
, hooknum
);
229 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
231 #include <linux/netfilter/nfnetlink.h>
232 #include <linux/netfilter/nfnetlink_conntrack.h>
234 static int icmp_tuple_to_nlattr(struct sk_buff
*skb
,
235 const struct nf_conntrack_tuple
*t
)
237 if (nla_put_be16(skb
, CTA_PROTO_ICMP_ID
, t
->src
.u
.icmp
.id
) ||
238 nla_put_u8(skb
, CTA_PROTO_ICMP_TYPE
, t
->dst
.u
.icmp
.type
) ||
239 nla_put_u8(skb
, CTA_PROTO_ICMP_CODE
, t
->dst
.u
.icmp
.code
))
240 goto nla_put_failure
;
247 static const struct nla_policy icmp_nla_policy
[CTA_PROTO_MAX
+1] = {
248 [CTA_PROTO_ICMP_TYPE
] = { .type
= NLA_U8
},
249 [CTA_PROTO_ICMP_CODE
] = { .type
= NLA_U8
},
250 [CTA_PROTO_ICMP_ID
] = { .type
= NLA_U16
},
253 static int icmp_nlattr_to_tuple(struct nlattr
*tb
[],
254 struct nf_conntrack_tuple
*tuple
)
256 if (!tb
[CTA_PROTO_ICMP_TYPE
] ||
257 !tb
[CTA_PROTO_ICMP_CODE
] ||
258 !tb
[CTA_PROTO_ICMP_ID
])
261 tuple
->dst
.u
.icmp
.type
= nla_get_u8(tb
[CTA_PROTO_ICMP_TYPE
]);
262 tuple
->dst
.u
.icmp
.code
= nla_get_u8(tb
[CTA_PROTO_ICMP_CODE
]);
263 tuple
->src
.u
.icmp
.id
= nla_get_be16(tb
[CTA_PROTO_ICMP_ID
]);
265 if (tuple
->dst
.u
.icmp
.type
>= sizeof(invmap
) ||
266 !invmap
[tuple
->dst
.u
.icmp
.type
])
272 static int icmp_nlattr_tuple_size(void)
274 return nla_policy_len(icmp_nla_policy
, CTA_PROTO_MAX
+ 1);
278 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
280 #include <linux/netfilter/nfnetlink.h>
281 #include <linux/netfilter/nfnetlink_cttimeout.h>
283 static int icmp_timeout_nlattr_to_obj(struct nlattr
*tb
[],
284 struct net
*net
, void *data
)
286 unsigned int *timeout
= data
;
287 struct nf_icmp_net
*in
= icmp_pernet(net
);
289 if (tb
[CTA_TIMEOUT_ICMP_TIMEOUT
]) {
291 ntohl(nla_get_be32(tb
[CTA_TIMEOUT_ICMP_TIMEOUT
])) * HZ
;
293 /* Set default ICMP timeout. */
294 *timeout
= in
->timeout
;
300 icmp_timeout_obj_to_nlattr(struct sk_buff
*skb
, const void *data
)
302 const unsigned int *timeout
= data
;
304 if (nla_put_be32(skb
, CTA_TIMEOUT_ICMP_TIMEOUT
, htonl(*timeout
/ HZ
)))
305 goto nla_put_failure
;
312 static const struct nla_policy
313 icmp_timeout_nla_policy
[CTA_TIMEOUT_ICMP_MAX
+1] = {
314 [CTA_TIMEOUT_ICMP_TIMEOUT
] = { .type
= NLA_U32
},
316 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
319 static struct ctl_table icmp_sysctl_table
[] = {
321 .procname
= "nf_conntrack_icmp_timeout",
322 .maxlen
= sizeof(unsigned int),
324 .proc_handler
= proc_dointvec_jiffies
,
328 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
329 static struct ctl_table icmp_compat_sysctl_table
[] = {
331 .procname
= "ip_conntrack_icmp_timeout",
332 .maxlen
= sizeof(unsigned int),
334 .proc_handler
= proc_dointvec_jiffies
,
338 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
339 #endif /* CONFIG_SYSCTL */
341 static int icmp_kmemdup_sysctl_table(struct nf_proto_net
*pn
,
342 struct nf_icmp_net
*in
)
345 pn
->ctl_table
= kmemdup(icmp_sysctl_table
,
346 sizeof(icmp_sysctl_table
),
351 pn
->ctl_table
[0].data
= &in
->timeout
;
356 static int icmp_kmemdup_compat_sysctl_table(struct nf_proto_net
*pn
,
357 struct nf_icmp_net
*in
)
360 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
361 pn
->ctl_compat_table
= kmemdup(icmp_compat_sysctl_table
,
362 sizeof(icmp_compat_sysctl_table
),
364 if (!pn
->ctl_compat_table
)
367 pn
->ctl_compat_table
[0].data
= &in
->timeout
;
373 static int icmp_init_net(struct net
*net
, u_int16_t proto
)
376 struct nf_icmp_net
*in
= icmp_pernet(net
);
377 struct nf_proto_net
*pn
= &in
->pn
;
379 in
->timeout
= nf_ct_icmp_timeout
;
381 ret
= icmp_kmemdup_compat_sysctl_table(pn
, in
);
385 ret
= icmp_kmemdup_sysctl_table(pn
, in
);
387 nf_ct_kfree_compat_sysctl_table(pn
);
392 static struct nf_proto_net
*icmp_get_net_proto(struct net
*net
)
394 return &net
->ct
.nf_ct_proto
.icmp
.pn
;
397 struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly
=
400 .l4proto
= IPPROTO_ICMP
,
402 .pkt_to_tuple
= icmp_pkt_to_tuple
,
403 .invert_tuple
= icmp_invert_tuple
,
404 .print_tuple
= icmp_print_tuple
,
405 .packet
= icmp_packet
,
406 .get_timeouts
= icmp_get_timeouts
,
411 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
412 .tuple_to_nlattr
= icmp_tuple_to_nlattr
,
413 .nlattr_tuple_size
= icmp_nlattr_tuple_size
,
414 .nlattr_to_tuple
= icmp_nlattr_to_tuple
,
415 .nla_policy
= icmp_nla_policy
,
417 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
419 .nlattr_to_obj
= icmp_timeout_nlattr_to_obj
,
420 .obj_to_nlattr
= icmp_timeout_obj_to_nlattr
,
421 .nlattr_max
= CTA_TIMEOUT_ICMP_MAX
,
422 .obj_size
= sizeof(unsigned int),
423 .nla_policy
= icmp_timeout_nla_policy
,
425 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
426 .init_net
= icmp_init_net
,
427 .get_net_proto
= icmp_get_net_proto
,