1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
9 #include <linux/types.h>
10 #include <linux/timer.h>
11 #include <linux/module.h>
12 #include <linux/udp.h>
13 #include <linux/seq_file.h>
14 #include <linux/skbuff.h>
15 #include <linux/ipv6.h>
16 #include <net/ip6_checksum.h>
17 #include <net/checksum.h>
19 #include <linux/netfilter.h>
20 #include <linux/netfilter_ipv4.h>
21 #include <linux/netfilter_ipv6.h>
22 #include <net/netfilter/nf_conntrack_l4proto.h>
23 #include <net/netfilter/nf_conntrack_ecache.h>
25 static unsigned int nf_ct_udp_timeout __read_mostly
= 30*HZ
;
26 static unsigned int nf_ct_udp_timeout_stream __read_mostly
= 180*HZ
;
28 static int udp_pkt_to_tuple(const struct sk_buff
*skb
,
30 struct nf_conntrack_tuple
*tuple
)
32 struct udphdr _hdr
, *hp
;
34 /* Actually only need first 8 bytes. */
35 hp
= skb_header_pointer(skb
, dataoff
, sizeof(_hdr
), &_hdr
);
39 tuple
->src
.u
.udp
.port
= hp
->source
;
40 tuple
->dst
.u
.udp
.port
= hp
->dest
;
45 static int udp_invert_tuple(struct nf_conntrack_tuple
*tuple
,
46 const struct nf_conntrack_tuple
*orig
)
48 tuple
->src
.u
.udp
.port
= orig
->dst
.u
.udp
.port
;
49 tuple
->dst
.u
.udp
.port
= orig
->src
.u
.udp
.port
;
53 /* Print out the per-protocol part of the tuple. */
54 static int udp_print_tuple(struct seq_file
*s
,
55 const struct nf_conntrack_tuple
*tuple
)
57 return seq_printf(s
, "sport=%hu dport=%hu ",
58 ntohs(tuple
->src
.u
.udp
.port
),
59 ntohs(tuple
->dst
.u
.udp
.port
));
62 /* Print out the private part of the conntrack. */
63 static int udp_print_conntrack(struct seq_file
*s
,
64 const struct nf_conn
*conntrack
)
69 /* Returns verdict for packet, and may modify conntracktype */
70 static int udp_packet(struct nf_conn
*conntrack
,
71 const struct sk_buff
*skb
,
73 enum ip_conntrack_info ctinfo
,
77 /* If we've seen traffic both ways, this is some kind of UDP
78 stream. Extend timeout. */
79 if (test_bit(IPS_SEEN_REPLY_BIT
, &conntrack
->status
)) {
80 nf_ct_refresh_acct(conntrack
, ctinfo
, skb
,
81 nf_ct_udp_timeout_stream
);
82 /* Also, more likely to be important, and not a probe */
83 if (!test_and_set_bit(IPS_ASSURED_BIT
, &conntrack
->status
))
84 nf_conntrack_event_cache(IPCT_STATUS
, skb
);
86 nf_ct_refresh_acct(conntrack
, ctinfo
, skb
, nf_ct_udp_timeout
);
91 /* Called when a new connection for this protocol found. */
92 static int udp_new(struct nf_conn
*conntrack
, const struct sk_buff
*skb
,
98 static int udp_error(struct sk_buff
*skb
, unsigned int dataoff
,
99 enum ip_conntrack_info
*ctinfo
,
101 unsigned int hooknum
)
103 unsigned int udplen
= skb
->len
- dataoff
;
104 struct udphdr _hdr
, *hdr
;
106 /* Header is too small? */
107 hdr
= skb_header_pointer(skb
, dataoff
, sizeof(_hdr
), &_hdr
);
109 if (LOG_INVALID(IPPROTO_UDP
))
110 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
111 "nf_ct_udp: short packet ");
115 /* Truncated/malformed packets */
116 if (ntohs(hdr
->len
) > udplen
|| ntohs(hdr
->len
) < sizeof(*hdr
)) {
117 if (LOG_INVALID(IPPROTO_UDP
))
118 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
119 "nf_ct_udp: truncated/malformed packet ");
123 /* Packet with no checksum */
127 /* Checksum invalid? Ignore.
128 * We skip checking packets on the outgoing path
129 * because the checksum is assumed to be correct.
130 * FIXME: Source route IP option packets --RR */
131 if (nf_conntrack_checksum
&&
132 ((pf
== PF_INET
&& hooknum
== NF_IP_PRE_ROUTING
) ||
133 (pf
== PF_INET6
&& hooknum
== NF_IP6_PRE_ROUTING
)) &&
134 nf_checksum(skb
, hooknum
, dataoff
, IPPROTO_UDP
, pf
)) {
135 if (LOG_INVALID(IPPROTO_UDP
))
136 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
137 "nf_ct_udp: bad UDP checksum ");
145 static unsigned int udp_sysctl_table_users
;
146 static struct ctl_table_header
*udp_sysctl_header
;
147 static struct ctl_table udp_sysctl_table
[] = {
149 .ctl_name
= NET_NF_CONNTRACK_UDP_TIMEOUT
,
150 .procname
= "nf_conntrack_udp_timeout",
151 .data
= &nf_ct_udp_timeout
,
152 .maxlen
= sizeof(unsigned int),
154 .proc_handler
= &proc_dointvec_jiffies
,
157 .ctl_name
= NET_NF_CONNTRACK_UDP_TIMEOUT_STREAM
,
158 .procname
= "nf_conntrack_udp_timeout_stream",
159 .data
= &nf_ct_udp_timeout_stream
,
160 .maxlen
= sizeof(unsigned int),
162 .proc_handler
= &proc_dointvec_jiffies
,
168 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
169 static struct ctl_table udp_compat_sysctl_table
[] = {
171 .ctl_name
= NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT
,
172 .procname
= "ip_conntrack_udp_timeout",
173 .data
= &nf_ct_udp_timeout
,
174 .maxlen
= sizeof(unsigned int),
176 .proc_handler
= &proc_dointvec_jiffies
,
179 .ctl_name
= NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT_STREAM
,
180 .procname
= "ip_conntrack_udp_timeout_stream",
181 .data
= &nf_ct_udp_timeout_stream
,
182 .maxlen
= sizeof(unsigned int),
184 .proc_handler
= &proc_dointvec_jiffies
,
190 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
191 #endif /* CONFIG_SYSCTL */
193 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 __read_mostly
=
196 .l4proto
= IPPROTO_UDP
,
198 .pkt_to_tuple
= udp_pkt_to_tuple
,
199 .invert_tuple
= udp_invert_tuple
,
200 .print_tuple
= udp_print_tuple
,
201 .print_conntrack
= udp_print_conntrack
,
202 .packet
= udp_packet
,
205 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
206 .tuple_to_nlattr
= nf_ct_port_tuple_to_nlattr
,
207 .nlattr_to_tuple
= nf_ct_port_nlattr_to_tuple
,
210 .ctl_table_users
= &udp_sysctl_table_users
,
211 .ctl_table_header
= &udp_sysctl_header
,
212 .ctl_table
= udp_sysctl_table
,
213 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
214 .ctl_compat_table
= udp_compat_sysctl_table
,
218 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4
);
220 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 __read_mostly
=
223 .l4proto
= IPPROTO_UDP
,
225 .pkt_to_tuple
= udp_pkt_to_tuple
,
226 .invert_tuple
= udp_invert_tuple
,
227 .print_tuple
= udp_print_tuple
,
228 .print_conntrack
= udp_print_conntrack
,
229 .packet
= udp_packet
,
232 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
233 .tuple_to_nlattr
= nf_ct_port_tuple_to_nlattr
,
234 .nlattr_to_tuple
= nf_ct_port_nlattr_to_tuple
,
237 .ctl_table_users
= &udp_sysctl_table_users
,
238 .ctl_table_header
= &udp_sysctl_header
,
239 .ctl_table
= udp_sysctl_table
,
242 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6
);