1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
3 * (C) 2007 Patrick McHardy <kaber@trash.net>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/types.h>
11 #include <linux/timer.h>
12 #include <linux/module.h>
13 #include <linux/udp.h>
14 #include <linux/seq_file.h>
15 #include <linux/skbuff.h>
16 #include <linux/ipv6.h>
17 #include <net/ip6_checksum.h>
18 #include <net/checksum.h>
20 #include <linux/netfilter.h>
21 #include <linux/netfilter_ipv4.h>
22 #include <linux/netfilter_ipv6.h>
23 #include <net/netfilter/nf_conntrack_l4proto.h>
24 #include <net/netfilter/nf_conntrack_ecache.h>
25 #include <net/netfilter/nf_log.h>
27 static unsigned int nf_ct_udplite_timeout __read_mostly = 30*HZ;
28 static unsigned int nf_ct_udplite_timeout_stream __read_mostly = 180*HZ;
30 static bool udplite_pkt_to_tuple(const struct sk_buff *skb,
32 struct nf_conntrack_tuple *tuple)
34 const struct udphdr *hp;
37 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
41 tuple->src.u.udp.port = hp->source;
42 tuple->dst.u.udp.port = hp->dest;
46 static bool udplite_invert_tuple(struct nf_conntrack_tuple *tuple,
47 const struct nf_conntrack_tuple *orig)
49 tuple->src.u.udp.port = orig->dst.u.udp.port;
50 tuple->dst.u.udp.port = orig->src.u.udp.port;
54 /* Print out the per-protocol part of the tuple. */
55 static int udplite_print_tuple(struct seq_file *s,
56 const struct nf_conntrack_tuple *tuple)
58 return seq_printf(s, "sport=%hu dport=%hu ",
59 ntohs(tuple->src.u.udp.port),
60 ntohs(tuple->dst.u.udp.port));
63 /* Returns verdict for packet, and may modify conntracktype */
64 static int udplite_packet(struct nf_conn *ct,
65 const struct sk_buff *skb,
67 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, &ct->status)) {
74 nf_ct_refresh_acct(ct, ctinfo, skb,
75 nf_ct_udplite_timeout_stream);
76 /* Also, more likely to be important, and not a probe */
77 if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
78 nf_conntrack_event_cache(IPCT_STATUS, ct);
80 nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_udplite_timeout);
85 /* Called when a new connection for this protocol found. */
86 static bool udplite_new(struct nf_conn *ct, const struct sk_buff *skb,
92 static int udplite_error(struct net *net,
95 enum ip_conntrack_info *ctinfo,
99 unsigned int udplen = skb->len - dataoff;
100 const struct udphdr *hdr;
104 /* Header is too small? */
105 hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
107 if (LOG_INVALID(net, IPPROTO_UDPLITE))
108 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
109 "nf_ct_udplite: short packet ");
113 cscov = ntohs(hdr->len);
116 else if (cscov < sizeof(*hdr) || cscov > udplen) {
117 if (LOG_INVALID(net, IPPROTO_UDPLITE))
118 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
119 "nf_ct_udplite: invalid checksum coverage ");
123 /* UDPLITE mandates checksums */
125 if (LOG_INVALID(net, IPPROTO_UDPLITE))
126 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
127 "nf_ct_udplite: checksum missing ");
131 /* Checksum invalid? Ignore. */
132 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
133 nf_checksum_partial(skb, hooknum, dataoff, cscov, IPPROTO_UDP,
135 if (LOG_INVALID(net, IPPROTO_UDPLITE))
136 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
137 "nf_ct_udplite: bad UDPLite checksum ");
145 static unsigned int udplite_sysctl_table_users;
146 static struct ctl_table_header *udplite_sysctl_header;
147 static struct ctl_table udplite_sysctl_table[] = {
149 .ctl_name = CTL_UNNUMBERED,
150 .procname = "nf_conntrack_udplite_timeout",
151 .data = &nf_ct_udplite_timeout,
152 .maxlen = sizeof(unsigned int),
154 .proc_handler = &proc_dointvec_jiffies,
157 .ctl_name = CTL_UNNUMBERED,
158 .procname = "nf_conntrack_udplite_timeout_stream",
159 .data = &nf_ct_udplite_timeout_stream,
160 .maxlen = sizeof(unsigned int),
162 .proc_handler = &proc_dointvec_jiffies,
168 #endif /* CONFIG_SYSCTL */
170 static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite4 __read_mostly =
173 .l4proto = IPPROTO_UDPLITE,
175 .pkt_to_tuple = udplite_pkt_to_tuple,
176 .invert_tuple = udplite_invert_tuple,
177 .print_tuple = udplite_print_tuple,
178 .packet = udplite_packet,
180 .error = udplite_error,
181 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
182 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
183 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
184 .nla_policy = nf_ct_port_nla_policy,
187 .ctl_table_users = &udplite_sysctl_table_users,
188 .ctl_table_header = &udplite_sysctl_header,
189 .ctl_table = udplite_sysctl_table,
193 static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite6 __read_mostly =
196 .l4proto = IPPROTO_UDPLITE,
198 .pkt_to_tuple = udplite_pkt_to_tuple,
199 .invert_tuple = udplite_invert_tuple,
200 .print_tuple = udplite_print_tuple,
201 .packet = udplite_packet,
203 .error = udplite_error,
204 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
205 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
206 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
207 .nla_policy = nf_ct_port_nla_policy,
210 .ctl_table_users = &udplite_sysctl_table_users,
211 .ctl_table_header = &udplite_sysctl_header,
212 .ctl_table = udplite_sysctl_table,
216 static int __init nf_conntrack_proto_udplite_init(void)
220 err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite4);
223 err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite6);
228 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
233 static void __exit nf_conntrack_proto_udplite_exit(void)
235 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite6);
236 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
239 module_init(nf_conntrack_proto_udplite_init);
240 module_exit(nf_conntrack_proto_udplite_exit);
242 MODULE_LICENSE("GPL");