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.
8 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
9 * - enable working with Layer 3 protocol independent connection tracking.
11 * Derived from net/ipv4/netfilter/ip_conntrack_proto_udp.c
14 #include <linux/types.h>
15 #include <linux/sched.h>
16 #include <linux/timer.h>
17 #include <linux/module.h>
18 #include <linux/netfilter.h>
19 #include <linux/udp.h>
20 #include <linux/seq_file.h>
21 #include <linux/skbuff.h>
22 #include <linux/ipv6.h>
23 #include <net/ip6_checksum.h>
24 #include <net/checksum.h>
26 #include <linux/netfilter.h>
27 #include <linux/netfilter_ipv4.h>
28 #include <linux/netfilter_ipv6.h>
29 #include <net/netfilter/nf_conntrack_l4proto.h>
30 #include <net/netfilter/nf_conntrack_ecache.h>
32 static unsigned int nf_ct_udp_timeout __read_mostly
= 30*HZ
;
33 static unsigned int nf_ct_udp_timeout_stream __read_mostly
= 180*HZ
;
35 static int udp_pkt_to_tuple(const struct sk_buff
*skb
,
37 struct nf_conntrack_tuple
*tuple
)
39 struct udphdr _hdr
, *hp
;
41 /* Actually only need first 8 bytes. */
42 hp
= skb_header_pointer(skb
, dataoff
, sizeof(_hdr
), &_hdr
);
46 tuple
->src
.u
.udp
.port
= hp
->source
;
47 tuple
->dst
.u
.udp
.port
= hp
->dest
;
52 static int udp_invert_tuple(struct nf_conntrack_tuple
*tuple
,
53 const struct nf_conntrack_tuple
*orig
)
55 tuple
->src
.u
.udp
.port
= orig
->dst
.u
.udp
.port
;
56 tuple
->dst
.u
.udp
.port
= orig
->src
.u
.udp
.port
;
60 /* Print out the per-protocol part of the tuple. */
61 static int udp_print_tuple(struct seq_file
*s
,
62 const struct nf_conntrack_tuple
*tuple
)
64 return seq_printf(s
, "sport=%hu dport=%hu ",
65 ntohs(tuple
->src
.u
.udp
.port
),
66 ntohs(tuple
->dst
.u
.udp
.port
));
69 /* Print out the private part of the conntrack. */
70 static int udp_print_conntrack(struct seq_file
*s
,
71 const struct nf_conn
*conntrack
)
76 /* Returns verdict for packet, and may modify conntracktype */
77 static int udp_packet(struct nf_conn
*conntrack
,
78 const struct sk_buff
*skb
,
80 enum ip_conntrack_info ctinfo
,
84 /* If we've seen traffic both ways, this is some kind of UDP
85 stream. Extend timeout. */
86 if (test_bit(IPS_SEEN_REPLY_BIT
, &conntrack
->status
)) {
87 nf_ct_refresh_acct(conntrack
, ctinfo
, skb
,
88 nf_ct_udp_timeout_stream
);
89 /* Also, more likely to be important, and not a probe */
90 if (!test_and_set_bit(IPS_ASSURED_BIT
, &conntrack
->status
))
91 nf_conntrack_event_cache(IPCT_STATUS
, skb
);
93 nf_ct_refresh_acct(conntrack
, ctinfo
, skb
, nf_ct_udp_timeout
);
98 /* Called when a new connection for this protocol found. */
99 static int udp_new(struct nf_conn
*conntrack
, const struct sk_buff
*skb
,
100 unsigned int dataoff
)
105 static int udp_error(struct sk_buff
*skb
, unsigned int dataoff
,
106 enum ip_conntrack_info
*ctinfo
,
108 unsigned int hooknum
)
110 unsigned int udplen
= skb
->len
- dataoff
;
111 struct udphdr _hdr
, *hdr
;
113 /* Header is too small? */
114 hdr
= skb_header_pointer(skb
, dataoff
, sizeof(_hdr
), &_hdr
);
116 if (LOG_INVALID(IPPROTO_UDP
))
117 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
118 "nf_ct_udp: short packet ");
122 /* Truncated/malformed packets */
123 if (ntohs(hdr
->len
) > udplen
|| ntohs(hdr
->len
) < sizeof(*hdr
)) {
124 if (LOG_INVALID(IPPROTO_UDP
))
125 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
126 "nf_ct_udp: truncated/malformed packet ");
130 /* Packet with no checksum */
134 /* Checksum invalid? Ignore.
135 * We skip checking packets on the outgoing path
136 * because the checksum is assumed to be correct.
137 * FIXME: Source route IP option packets --RR */
138 if (nf_conntrack_checksum
&&
139 ((pf
== PF_INET
&& hooknum
== NF_IP_PRE_ROUTING
) ||
140 (pf
== PF_INET6
&& hooknum
== NF_IP6_PRE_ROUTING
)) &&
141 nf_checksum(skb
, hooknum
, dataoff
, IPPROTO_UDP
, pf
)) {
142 if (LOG_INVALID(IPPROTO_UDP
))
143 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
144 "nf_ct_udp: bad UDP checksum ");
152 static unsigned int udp_sysctl_table_users
;
153 static struct ctl_table_header
*udp_sysctl_header
;
154 static struct ctl_table udp_sysctl_table
[] = {
156 .ctl_name
= NET_NF_CONNTRACK_UDP_TIMEOUT
,
157 .procname
= "nf_conntrack_udp_timeout",
158 .data
= &nf_ct_udp_timeout
,
159 .maxlen
= sizeof(unsigned int),
161 .proc_handler
= &proc_dointvec_jiffies
,
164 .ctl_name
= NET_NF_CONNTRACK_UDP_TIMEOUT_STREAM
,
165 .procname
= "nf_conntrack_udp_timeout_stream",
166 .data
= &nf_ct_udp_timeout_stream
,
167 .maxlen
= sizeof(unsigned int),
169 .proc_handler
= &proc_dointvec_jiffies
,
175 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
176 static struct ctl_table udp_compat_sysctl_table
[] = {
178 .ctl_name
= NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT
,
179 .procname
= "ip_conntrack_udp_timeout",
180 .data
= &nf_ct_udp_timeout
,
181 .maxlen
= sizeof(unsigned int),
183 .proc_handler
= &proc_dointvec_jiffies
,
186 .ctl_name
= NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT_STREAM
,
187 .procname
= "ip_conntrack_udp_timeout_stream",
188 .data
= &nf_ct_udp_timeout_stream
,
189 .maxlen
= sizeof(unsigned int),
191 .proc_handler
= &proc_dointvec_jiffies
,
197 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
198 #endif /* CONFIG_SYSCTL */
200 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4
=
203 .l4proto
= IPPROTO_UDP
,
205 .pkt_to_tuple
= udp_pkt_to_tuple
,
206 .invert_tuple
= udp_invert_tuple
,
207 .print_tuple
= udp_print_tuple
,
208 .print_conntrack
= udp_print_conntrack
,
209 .packet
= udp_packet
,
212 #if defined(CONFIG_NF_CT_NETLINK) || \
213 defined(CONFIG_NF_CT_NETLINK_MODULE)
214 .tuple_to_nfattr
= nf_ct_port_tuple_to_nfattr
,
215 .nfattr_to_tuple
= nf_ct_port_nfattr_to_tuple
,
218 .ctl_table_users
= &udp_sysctl_table_users
,
219 .ctl_table_header
= &udp_sysctl_header
,
220 .ctl_table
= udp_sysctl_table
,
221 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
222 .ctl_compat_table
= udp_compat_sysctl_table
,
226 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4
);
228 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6
=
231 .l4proto
= IPPROTO_UDP
,
233 .pkt_to_tuple
= udp_pkt_to_tuple
,
234 .invert_tuple
= udp_invert_tuple
,
235 .print_tuple
= udp_print_tuple
,
236 .print_conntrack
= udp_print_conntrack
,
237 .packet
= udp_packet
,
240 #if defined(CONFIG_NF_CT_NETLINK) || \
241 defined(CONFIG_NF_CT_NETLINK_MODULE)
242 .tuple_to_nfattr
= nf_ct_port_tuple_to_nfattr
,
243 .nfattr_to_tuple
= nf_ct_port_nfattr_to_tuple
,
246 .ctl_table_users
= &udp_sysctl_table_users
,
247 .ctl_table_header
= &udp_sysctl_header
,
248 .ctl_table
= udp_sysctl_table
,
251 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6
);