1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
3 * (C) 2006-2012 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/module.h>
13 #include <linux/udp.h>
14 #include <linux/seq_file.h>
15 #include <linux/skbuff.h>
16 #include <linux/ipv6.h>
17 #include <net/ip6_checksum.h>
18 #include <net/checksum.h>
20 #include <linux/netfilter.h>
21 #include <linux/netfilter_ipv4.h>
22 #include <linux/netfilter_ipv6.h>
23 #include <net/netfilter/nf_conntrack_l4proto.h>
24 #include <net/netfilter/nf_conntrack_ecache.h>
25 #include <net/netfilter/nf_conntrack_timeout.h>
26 #include <net/netfilter/nf_log.h>
27 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
28 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
30 static const unsigned int udp_timeouts
[UDP_CT_MAX
] = {
31 [UDP_CT_UNREPLIED
] = 30*HZ
,
32 [UDP_CT_REPLIED
] = 120*HZ
,
35 static unsigned int *udp_get_timeouts(struct net
*net
)
37 return nf_udp_pernet(net
)->timeouts
;
40 static void udp_error_log(const struct sk_buff
*skb
,
41 const struct nf_hook_state
*state
,
44 nf_l4proto_log_invalid(skb
, state
->net
, state
->pf
,
45 IPPROTO_UDP
, "%s", msg
);
48 static bool udp_error(struct sk_buff
*skb
,
50 const struct nf_hook_state
*state
)
52 unsigned int udplen
= skb
->len
- dataoff
;
53 const struct udphdr
*hdr
;
56 /* Header is too small? */
57 hdr
= skb_header_pointer(skb
, dataoff
, sizeof(_hdr
), &_hdr
);
59 udp_error_log(skb
, state
, "short packet");
63 /* Truncated/malformed packets */
64 if (ntohs(hdr
->len
) > udplen
|| ntohs(hdr
->len
) < sizeof(*hdr
)) {
65 udp_error_log(skb
, state
, "truncated/malformed packet");
69 /* Packet with no checksum */
73 /* Checksum invalid? Ignore.
74 * We skip checking packets on the outgoing path
75 * because the checksum is assumed to be correct.
76 * FIXME: Source route IP option packets --RR */
77 if (state
->hook
== NF_INET_PRE_ROUTING
&&
78 state
->net
->ct
.sysctl_checksum
&&
79 nf_checksum(skb
, state
->hook
, dataoff
, IPPROTO_UDP
, state
->pf
)) {
80 udp_error_log(skb
, state
, "bad checksum");
87 /* Returns verdict for packet, and may modify conntracktype */
88 static int udp_packet(struct nf_conn
*ct
,
91 enum ip_conntrack_info ctinfo
,
92 const struct nf_hook_state
*state
)
94 unsigned int *timeouts
;
96 if (udp_error(skb
, dataoff
, state
))
99 timeouts
= nf_ct_timeout_lookup(ct
);
101 timeouts
= udp_get_timeouts(nf_ct_net(ct
));
103 if (!nf_ct_is_confirmed(ct
))
104 ct
->proto
.udp
.stream_ts
= 2 * HZ
+ jiffies
;
106 /* If we've seen traffic both ways, this is some kind of UDP
107 * stream. Set Assured.
109 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
110 unsigned long extra
= timeouts
[UDP_CT_UNREPLIED
];
112 /* Still active after two seconds? Extend timeout. */
113 if (time_after(jiffies
, ct
->proto
.udp
.stream_ts
))
114 extra
= timeouts
[UDP_CT_REPLIED
];
116 nf_ct_refresh_acct(ct
, ctinfo
, skb
, extra
);
118 /* Also, more likely to be important, and not a probe */
119 if (!test_and_set_bit(IPS_ASSURED_BIT
, &ct
->status
))
120 nf_conntrack_event_cache(IPCT_ASSURED
, ct
);
122 nf_ct_refresh_acct(ct
, ctinfo
, skb
,
123 timeouts
[UDP_CT_UNREPLIED
]);
128 #ifdef CONFIG_NF_CT_PROTO_UDPLITE
129 static void udplite_error_log(const struct sk_buff
*skb
,
130 const struct nf_hook_state
*state
,
133 nf_l4proto_log_invalid(skb
, state
->net
, state
->pf
,
134 IPPROTO_UDPLITE
, "%s", msg
);
137 static bool udplite_error(struct sk_buff
*skb
,
138 unsigned int dataoff
,
139 const struct nf_hook_state
*state
)
141 unsigned int udplen
= skb
->len
- dataoff
;
142 const struct udphdr
*hdr
;
146 /* Header is too small? */
147 hdr
= skb_header_pointer(skb
, dataoff
, sizeof(_hdr
), &_hdr
);
149 udplite_error_log(skb
, state
, "short packet");
153 cscov
= ntohs(hdr
->len
);
156 } else if (cscov
< sizeof(*hdr
) || cscov
> udplen
) {
157 udplite_error_log(skb
, state
, "invalid checksum coverage");
161 /* UDPLITE mandates checksums */
163 udplite_error_log(skb
, state
, "checksum missing");
167 /* Checksum invalid? Ignore. */
168 if (state
->hook
== NF_INET_PRE_ROUTING
&&
169 state
->net
->ct
.sysctl_checksum
&&
170 nf_checksum_partial(skb
, state
->hook
, dataoff
, cscov
, IPPROTO_UDP
,
172 udplite_error_log(skb
, state
, "bad checksum");
179 /* Returns verdict for packet, and may modify conntracktype */
180 static int udplite_packet(struct nf_conn
*ct
,
182 unsigned int dataoff
,
183 enum ip_conntrack_info ctinfo
,
184 const struct nf_hook_state
*state
)
186 unsigned int *timeouts
;
188 if (udplite_error(skb
, dataoff
, state
))
191 timeouts
= nf_ct_timeout_lookup(ct
);
193 timeouts
= udp_get_timeouts(nf_ct_net(ct
));
195 /* If we've seen traffic both ways, this is some kind of UDP
196 stream. Extend timeout. */
197 if (test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
198 nf_ct_refresh_acct(ct
, ctinfo
, skb
,
199 timeouts
[UDP_CT_REPLIED
]);
200 /* Also, more likely to be important, and not a probe */
201 if (!test_and_set_bit(IPS_ASSURED_BIT
, &ct
->status
))
202 nf_conntrack_event_cache(IPCT_ASSURED
, ct
);
204 nf_ct_refresh_acct(ct
, ctinfo
, skb
,
205 timeouts
[UDP_CT_UNREPLIED
]);
211 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
213 #include <linux/netfilter/nfnetlink.h>
214 #include <linux/netfilter/nfnetlink_cttimeout.h>
216 static int udp_timeout_nlattr_to_obj(struct nlattr
*tb
[],
217 struct net
*net
, void *data
)
219 unsigned int *timeouts
= data
;
220 struct nf_udp_net
*un
= nf_udp_pernet(net
);
223 timeouts
= un
->timeouts
;
225 /* set default timeouts for UDP. */
226 timeouts
[UDP_CT_UNREPLIED
] = un
->timeouts
[UDP_CT_UNREPLIED
];
227 timeouts
[UDP_CT_REPLIED
] = un
->timeouts
[UDP_CT_REPLIED
];
229 if (tb
[CTA_TIMEOUT_UDP_UNREPLIED
]) {
230 timeouts
[UDP_CT_UNREPLIED
] =
231 ntohl(nla_get_be32(tb
[CTA_TIMEOUT_UDP_UNREPLIED
])) * HZ
;
233 if (tb
[CTA_TIMEOUT_UDP_REPLIED
]) {
234 timeouts
[UDP_CT_REPLIED
] =
235 ntohl(nla_get_be32(tb
[CTA_TIMEOUT_UDP_REPLIED
])) * HZ
;
241 udp_timeout_obj_to_nlattr(struct sk_buff
*skb
, const void *data
)
243 const unsigned int *timeouts
= data
;
245 if (nla_put_be32(skb
, CTA_TIMEOUT_UDP_UNREPLIED
,
246 htonl(timeouts
[UDP_CT_UNREPLIED
] / HZ
)) ||
247 nla_put_be32(skb
, CTA_TIMEOUT_UDP_REPLIED
,
248 htonl(timeouts
[UDP_CT_REPLIED
] / HZ
)))
249 goto nla_put_failure
;
256 static const struct nla_policy
257 udp_timeout_nla_policy
[CTA_TIMEOUT_UDP_MAX
+1] = {
258 [CTA_TIMEOUT_UDP_UNREPLIED
] = { .type
= NLA_U32
},
259 [CTA_TIMEOUT_UDP_REPLIED
] = { .type
= NLA_U32
},
261 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
264 static struct ctl_table udp_sysctl_table
[] = {
266 .procname
= "nf_conntrack_udp_timeout",
267 .maxlen
= sizeof(unsigned int),
269 .proc_handler
= proc_dointvec_jiffies
,
272 .procname
= "nf_conntrack_udp_timeout_stream",
273 .maxlen
= sizeof(unsigned int),
275 .proc_handler
= proc_dointvec_jiffies
,
279 #endif /* CONFIG_SYSCTL */
281 static int udp_kmemdup_sysctl_table(struct nf_proto_net
*pn
,
282 struct nf_udp_net
*un
)
287 pn
->ctl_table
= kmemdup(udp_sysctl_table
,
288 sizeof(udp_sysctl_table
),
292 pn
->ctl_table
[0].data
= &un
->timeouts
[UDP_CT_UNREPLIED
];
293 pn
->ctl_table
[1].data
= &un
->timeouts
[UDP_CT_REPLIED
];
298 static int udp_init_net(struct net
*net
)
300 struct nf_udp_net
*un
= nf_udp_pernet(net
);
301 struct nf_proto_net
*pn
= &un
->pn
;
306 for (i
= 0; i
< UDP_CT_MAX
; i
++)
307 un
->timeouts
[i
] = udp_timeouts
[i
];
310 return udp_kmemdup_sysctl_table(pn
, un
);
313 static struct nf_proto_net
*udp_get_net_proto(struct net
*net
)
315 return &net
->ct
.nf_ct_proto
.udp
.pn
;
318 const struct nf_conntrack_l4proto nf_conntrack_l4proto_udp
=
320 .l4proto
= IPPROTO_UDP
,
322 .packet
= udp_packet
,
323 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
324 .tuple_to_nlattr
= nf_ct_port_tuple_to_nlattr
,
325 .nlattr_to_tuple
= nf_ct_port_nlattr_to_tuple
,
326 .nlattr_tuple_size
= nf_ct_port_nlattr_tuple_size
,
327 .nla_policy
= nf_ct_port_nla_policy
,
329 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
331 .nlattr_to_obj
= udp_timeout_nlattr_to_obj
,
332 .obj_to_nlattr
= udp_timeout_obj_to_nlattr
,
333 .nlattr_max
= CTA_TIMEOUT_UDP_MAX
,
334 .obj_size
= sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX
,
335 .nla_policy
= udp_timeout_nla_policy
,
337 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
338 .init_net
= udp_init_net
,
339 .get_net_proto
= udp_get_net_proto
,
342 #ifdef CONFIG_NF_CT_PROTO_UDPLITE
343 const struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite
=
345 .l4proto
= IPPROTO_UDPLITE
,
347 .packet
= udplite_packet
,
348 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
349 .tuple_to_nlattr
= nf_ct_port_tuple_to_nlattr
,
350 .nlattr_to_tuple
= nf_ct_port_nlattr_to_tuple
,
351 .nlattr_tuple_size
= nf_ct_port_nlattr_tuple_size
,
352 .nla_policy
= nf_ct_port_nla_policy
,
354 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
356 .nlattr_to_obj
= udp_timeout_nlattr_to_obj
,
357 .obj_to_nlattr
= udp_timeout_obj_to_nlattr
,
358 .nlattr_max
= CTA_TIMEOUT_UDP_MAX
,
359 .obj_size
= sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX
,
360 .nla_policy
= udp_timeout_nla_policy
,
362 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
363 .init_net
= udp_init_net
,
364 .get_net_proto
= udp_get_net_proto
,