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>
25 #include <linux/netfilter.h>
26 #include <linux/netfilter_ipv4.h>
27 #include <linux/netfilter_ipv6.h>
28 #include <net/netfilter/nf_conntrack_protocol.h>
30 unsigned int nf_ct_udp_timeout __read_mostly
= 30*HZ
;
31 unsigned int nf_ct_udp_timeout_stream __read_mostly
= 180*HZ
;
33 static int udp_pkt_to_tuple(const struct sk_buff
*skb
,
35 struct nf_conntrack_tuple
*tuple
)
37 struct udphdr _hdr
, *hp
;
39 /* Actually only need first 8 bytes. */
40 hp
= skb_header_pointer(skb
, dataoff
, sizeof(_hdr
), &_hdr
);
44 tuple
->src
.u
.udp
.port
= hp
->source
;
45 tuple
->dst
.u
.udp
.port
= hp
->dest
;
50 static int udp_invert_tuple(struct nf_conntrack_tuple
*tuple
,
51 const struct nf_conntrack_tuple
*orig
)
53 tuple
->src
.u
.udp
.port
= orig
->dst
.u
.udp
.port
;
54 tuple
->dst
.u
.udp
.port
= orig
->src
.u
.udp
.port
;
58 /* Print out the per-protocol part of the tuple. */
59 static int udp_print_tuple(struct seq_file
*s
,
60 const struct nf_conntrack_tuple
*tuple
)
62 return seq_printf(s
, "sport=%hu dport=%hu ",
63 ntohs(tuple
->src
.u
.udp
.port
),
64 ntohs(tuple
->dst
.u
.udp
.port
));
67 /* Print out the private part of the conntrack. */
68 static int udp_print_conntrack(struct seq_file
*s
,
69 const struct nf_conn
*conntrack
)
74 /* Returns verdict for packet, and may modify conntracktype */
75 static int udp_packet(struct nf_conn
*conntrack
,
76 const struct sk_buff
*skb
,
78 enum ip_conntrack_info ctinfo
,
82 /* If we've seen traffic both ways, this is some kind of UDP
83 stream. Extend timeout. */
84 if (test_bit(IPS_SEEN_REPLY_BIT
, &conntrack
->status
)) {
85 nf_ct_refresh_acct(conntrack
, ctinfo
, skb
,
86 nf_ct_udp_timeout_stream
);
87 /* Also, more likely to be important, and not a probe */
88 if (!test_and_set_bit(IPS_ASSURED_BIT
, &conntrack
->status
))
89 nf_conntrack_event_cache(IPCT_STATUS
, skb
);
91 nf_ct_refresh_acct(conntrack
, ctinfo
, skb
, nf_ct_udp_timeout
);
96 /* Called when a new connection for this protocol found. */
97 static int udp_new(struct nf_conn
*conntrack
, const struct sk_buff
*skb
,
103 static int udp_error(struct sk_buff
*skb
, unsigned int dataoff
,
104 enum ip_conntrack_info
*ctinfo
,
106 unsigned int hooknum
)
108 unsigned int udplen
= skb
->len
- dataoff
;
109 struct udphdr _hdr
, *hdr
;
111 /* Header is too small? */
112 hdr
= skb_header_pointer(skb
, dataoff
, sizeof(_hdr
), &_hdr
);
114 if (LOG_INVALID(IPPROTO_UDP
))
115 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
116 "nf_ct_udp: short packet ");
120 /* Truncated/malformed packets */
121 if (ntohs(hdr
->len
) > udplen
|| ntohs(hdr
->len
) < sizeof(*hdr
)) {
122 if (LOG_INVALID(IPPROTO_UDP
))
123 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
124 "nf_ct_udp: truncated/malformed packet ");
128 /* Packet with no checksum */
132 /* Checksum invalid? Ignore.
133 * We skip checking packets on the outgoing path
134 * because the checksum is assumed to be correct.
135 * FIXME: Source route IP option packets --RR */
136 if (nf_conntrack_checksum
&&
137 ((pf
== PF_INET
&& hooknum
== NF_IP_PRE_ROUTING
) ||
138 (pf
== PF_INET6
&& hooknum
== NF_IP6_PRE_ROUTING
)) &&
139 nf_checksum(skb
, hooknum
, dataoff
, IPPROTO_UDP
, pf
)) {
140 if (LOG_INVALID(IPPROTO_UDP
))
141 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
142 "nf_ct_udp: bad UDP checksum ");
149 struct nf_conntrack_protocol nf_conntrack_protocol_udp4
=
152 .proto
= IPPROTO_UDP
,
154 .pkt_to_tuple
= udp_pkt_to_tuple
,
155 .invert_tuple
= udp_invert_tuple
,
156 .print_tuple
= udp_print_tuple
,
157 .print_conntrack
= udp_print_conntrack
,
158 .packet
= udp_packet
,
161 #if defined(CONFIG_NF_CT_NETLINK) || \
162 defined(CONFIG_NF_CT_NETLINK_MODULE)
163 .tuple_to_nfattr
= nf_ct_port_tuple_to_nfattr
,
164 .nfattr_to_tuple
= nf_ct_port_nfattr_to_tuple
,
168 struct nf_conntrack_protocol nf_conntrack_protocol_udp6
=
171 .proto
= IPPROTO_UDP
,
173 .pkt_to_tuple
= udp_pkt_to_tuple
,
174 .invert_tuple
= udp_invert_tuple
,
175 .print_tuple
= udp_print_tuple
,
176 .print_conntrack
= udp_print_conntrack
,
177 .packet
= udp_packet
,
180 #if defined(CONFIG_NF_CT_NETLINK) || \
181 defined(CONFIG_NF_CT_NETLINK_MODULE)
182 .tuple_to_nfattr
= nf_ct_port_tuple_to_nfattr
,
183 .nfattr_to_tuple
= nf_ct_port_nfattr_to_tuple
,
187 EXPORT_SYMBOL(nf_conntrack_protocol_udp4
);
188 EXPORT_SYMBOL(nf_conntrack_protocol_udp6
);