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.h>
19 #include <linux/netfilter_ipv4.h>
20 #include <linux/netfilter_ipv4/ip_conntrack_protocol.h>
22 unsigned long ip_ct_udp_timeout
= 30*HZ
;
23 unsigned long ip_ct_udp_timeout_stream
= 180*HZ
;
25 static int udp_pkt_to_tuple(const struct sk_buff
*skb
,
27 struct ip_conntrack_tuple
*tuple
)
29 struct udphdr _hdr
, *hp
;
31 /* Actually only need first 8 bytes. */
32 hp
= skb_header_pointer(skb
, dataoff
, sizeof(_hdr
), &_hdr
);
36 tuple
->src
.u
.udp
.port
= hp
->source
;
37 tuple
->dst
.u
.udp
.port
= hp
->dest
;
42 static int udp_invert_tuple(struct ip_conntrack_tuple
*tuple
,
43 const struct ip_conntrack_tuple
*orig
)
45 tuple
->src
.u
.udp
.port
= orig
->dst
.u
.udp
.port
;
46 tuple
->dst
.u
.udp
.port
= orig
->src
.u
.udp
.port
;
50 /* Print out the per-protocol part of the tuple. */
51 static int udp_print_tuple(struct seq_file
*s
,
52 const struct ip_conntrack_tuple
*tuple
)
54 return seq_printf(s
, "sport=%hu dport=%hu ",
55 ntohs(tuple
->src
.u
.udp
.port
),
56 ntohs(tuple
->dst
.u
.udp
.port
));
59 /* Print out the private part of the conntrack. */
60 static int udp_print_conntrack(struct seq_file
*s
,
61 const struct ip_conntrack
*conntrack
)
66 /* Returns verdict for packet, and may modify conntracktype */
67 static int udp_packet(struct ip_conntrack
*conntrack
,
68 const struct sk_buff
*skb
,
69 enum ip_conntrack_info ctinfo
)
71 /* If we've seen traffic both ways, this is some kind of UDP
72 stream. Extend timeout. */
73 if (test_bit(IPS_SEEN_REPLY_BIT
, &conntrack
->status
)) {
74 ip_ct_refresh_acct(conntrack
, ctinfo
, skb
,
75 ip_ct_udp_timeout_stream
);
76 /* Also, more likely to be important, and not a probe */
77 if (!test_and_set_bit(IPS_ASSURED_BIT
, &conntrack
->status
))
78 ip_conntrack_event_cache(IPCT_STATUS
, skb
);
80 ip_ct_refresh_acct(conntrack
, ctinfo
, skb
, ip_ct_udp_timeout
);
85 /* Called when a new connection for this protocol found. */
86 static int udp_new(struct ip_conntrack
*conntrack
, const struct sk_buff
*skb
)
91 static int udp_error(struct sk_buff
*skb
, enum ip_conntrack_info
*ctinfo
,
94 struct iphdr
*iph
= skb
->nh
.iph
;
95 unsigned int udplen
= skb
->len
- iph
->ihl
* 4;
96 struct udphdr _hdr
, *hdr
;
98 /* Header is too small? */
99 hdr
= skb_header_pointer(skb
, iph
->ihl
*4, sizeof(_hdr
), &_hdr
);
101 if (LOG_INVALID(IPPROTO_UDP
))
102 nf_log_packet(PF_INET
, 0, skb
, NULL
, NULL
, NULL
,
103 "ip_ct_udp: short packet ");
107 /* Truncated/malformed packets */
108 if (ntohs(hdr
->len
) > udplen
|| ntohs(hdr
->len
) < sizeof(*hdr
)) {
109 if (LOG_INVALID(IPPROTO_UDP
))
110 nf_log_packet(PF_INET
, 0, skb
, NULL
, NULL
, NULL
,
111 "ip_ct_udp: truncated/malformed packet ");
115 /* Packet with no checksum */
119 /* Checksum invalid? Ignore.
120 * We skip checking packets on the outgoing path
121 * because the semantic of CHECKSUM_HW is different there
122 * and moreover root might send raw packets.
123 * FIXME: Source route IP option packets --RR */
124 if (hooknum
== NF_IP_PRE_ROUTING
125 && skb
->ip_summed
!= CHECKSUM_UNNECESSARY
126 && csum_tcpudp_magic(iph
->saddr
, iph
->daddr
, udplen
, IPPROTO_UDP
,
127 skb
->ip_summed
== CHECKSUM_HW
? skb
->csum
128 : skb_checksum(skb
, iph
->ihl
*4, udplen
, 0))) {
129 if (LOG_INVALID(IPPROTO_UDP
))
130 nf_log_packet(PF_INET
, 0, skb
, NULL
, NULL
, NULL
,
131 "ip_ct_udp: bad UDP checksum ");
138 struct ip_conntrack_protocol ip_conntrack_protocol_udp
=
140 .proto
= IPPROTO_UDP
,
142 .pkt_to_tuple
= udp_pkt_to_tuple
,
143 .invert_tuple
= udp_invert_tuple
,
144 .print_tuple
= udp_print_tuple
,
145 .print_conntrack
= udp_print_conntrack
,
146 .packet
= udp_packet
,
149 #if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
150 defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
151 .tuple_to_nfattr
= ip_ct_port_tuple_to_nfattr
,
152 .nfattr_to_tuple
= ip_ct_port_nfattr_to_tuple
,