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/sched.h>
11 #include <linux/timer.h>
12 #include <linux/netfilter.h>
15 #include <linux/udp.h>
16 #include <linux/seq_file.h>
17 #include <net/checksum.h>
18 #include <linux/netfilter_ipv4.h>
19 #include <linux/netfilter_ipv4/ip_conntrack_protocol.h>
21 unsigned int ip_ct_udp_timeout __read_mostly
= 30*HZ
;
22 unsigned int ip_ct_udp_timeout_stream __read_mostly
= 180*HZ
;
24 static int udp_pkt_to_tuple(const struct sk_buff
*skb
,
26 struct ip_conntrack_tuple
*tuple
)
28 struct udphdr _hdr
, *hp
;
30 /* Actually only need first 8 bytes. */
31 hp
= skb_header_pointer(skb
, dataoff
, sizeof(_hdr
), &_hdr
);
35 tuple
->src
.u
.udp
.port
= hp
->source
;
36 tuple
->dst
.u
.udp
.port
= hp
->dest
;
41 static int udp_invert_tuple(struct ip_conntrack_tuple
*tuple
,
42 const struct ip_conntrack_tuple
*orig
)
44 tuple
->src
.u
.udp
.port
= orig
->dst
.u
.udp
.port
;
45 tuple
->dst
.u
.udp
.port
= orig
->src
.u
.udp
.port
;
49 /* Print out the per-protocol part of the tuple. */
50 static int udp_print_tuple(struct seq_file
*s
,
51 const struct ip_conntrack_tuple
*tuple
)
53 return seq_printf(s
, "sport=%hu dport=%hu ",
54 ntohs(tuple
->src
.u
.udp
.port
),
55 ntohs(tuple
->dst
.u
.udp
.port
));
58 /* Print out the private part of the conntrack. */
59 static int udp_print_conntrack(struct seq_file
*s
,
60 const struct ip_conntrack
*conntrack
)
65 /* Returns verdict for packet, and may modify conntracktype */
66 static int udp_packet(struct ip_conntrack
*conntrack
,
67 const struct sk_buff
*skb
,
68 enum ip_conntrack_info ctinfo
)
70 /* If we've seen traffic both ways, this is some kind of UDP
71 stream. Extend timeout. */
72 if (test_bit(IPS_SEEN_REPLY_BIT
, &conntrack
->status
)) {
73 ip_ct_refresh_acct(conntrack
, ctinfo
, skb
,
74 ip_ct_udp_timeout_stream
);
75 /* Also, more likely to be important, and not a probe */
76 if (!test_and_set_bit(IPS_ASSURED_BIT
, &conntrack
->status
))
77 ip_conntrack_event_cache(IPCT_STATUS
, skb
);
79 ip_ct_refresh_acct(conntrack
, ctinfo
, skb
, ip_ct_udp_timeout
);
84 /* Called when a new connection for this protocol found. */
85 static int udp_new(struct ip_conntrack
*conntrack
, const struct sk_buff
*skb
)
90 static int udp_error(struct sk_buff
*skb
, enum ip_conntrack_info
*ctinfo
,
93 struct iphdr
*iph
= skb
->nh
.iph
;
94 unsigned int udplen
= skb
->len
- iph
->ihl
* 4;
95 struct udphdr _hdr
, *hdr
;
97 /* Header is too small? */
98 hdr
= skb_header_pointer(skb
, iph
->ihl
*4, sizeof(_hdr
), &_hdr
);
100 if (LOG_INVALID(IPPROTO_UDP
))
101 nf_log_packet(PF_INET
, 0, skb
, NULL
, NULL
, NULL
,
102 "ip_ct_udp: short packet ");
106 /* Truncated/malformed packets */
107 if (ntohs(hdr
->len
) > udplen
|| ntohs(hdr
->len
) < sizeof(*hdr
)) {
108 if (LOG_INVALID(IPPROTO_UDP
))
109 nf_log_packet(PF_INET
, 0, skb
, NULL
, NULL
, NULL
,
110 "ip_ct_udp: truncated/malformed packet ");
114 /* Packet with no checksum */
118 /* Checksum invalid? Ignore.
119 * We skip checking packets on the outgoing path
120 * because the checksum is assumed to be correct.
121 * FIXME: Source route IP option packets --RR */
122 if (ip_conntrack_checksum
&& hooknum
== NF_IP_PRE_ROUTING
&&
123 nf_ip_checksum(skb
, hooknum
, iph
->ihl
* 4, IPPROTO_UDP
)) {
124 if (LOG_INVALID(IPPROTO_UDP
))
125 nf_log_packet(PF_INET
, 0, skb
, NULL
, NULL
, NULL
,
126 "ip_ct_udp: bad UDP checksum ");
133 struct ip_conntrack_protocol ip_conntrack_protocol_udp
=
135 .proto
= IPPROTO_UDP
,
137 .pkt_to_tuple
= udp_pkt_to_tuple
,
138 .invert_tuple
= udp_invert_tuple
,
139 .print_tuple
= udp_print_tuple
,
140 .print_conntrack
= udp_print_conntrack
,
141 .packet
= udp_packet
,
144 #if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
145 defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
146 .tuple_to_nfattr
= ip_ct_port_tuple_to_nfattr
,
147 .nfattr_to_tuple
= ip_ct_port_nfattr_to_tuple
,