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 int udplite_pkt_to_tuple(const struct sk_buff *skb,
32 struct nf_conntrack_tuple *tuple)
34 struct udphdr _hdr, *hp;
36 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
40 tuple->src.u.udp.port = hp->source;
41 tuple->dst.u.udp.port = hp->dest;
45 static int udplite_invert_tuple(struct nf_conntrack_tuple *tuple,
46 const struct nf_conntrack_tuple *orig)
48 tuple->src.u.udp.port = orig->dst.u.udp.port;
49 tuple->dst.u.udp.port = orig->src.u.udp.port;
53 /* Print out the per-protocol part of the tuple. */
54 static int udplite_print_tuple(struct seq_file *s,
55 const struct nf_conntrack_tuple *tuple)
57 return seq_printf(s, "sport=%hu dport=%hu ",
58 ntohs(tuple->src.u.udp.port),
59 ntohs(tuple->dst.u.udp.port));
62 /* Returns verdict for packet, and may modify conntracktype */
63 static int udplite_packet(struct nf_conn *conntrack,
64 const struct sk_buff *skb,
66 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 nf_ct_refresh_acct(conntrack, ctinfo, skb,
74 nf_ct_udplite_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 nf_conntrack_event_cache(IPCT_STATUS, skb);
79 nf_ct_refresh_acct(conntrack, ctinfo, skb,
80 nf_ct_udplite_timeout);
85 /* Called when a new connection for this protocol found. */
86 static int udplite_new(struct nf_conn *conntrack, const struct sk_buff *skb,
92 static int udplite_error(struct sk_buff *skb, unsigned int dataoff,
93 enum ip_conntrack_info *ctinfo,
97 unsigned int udplen = skb->len - dataoff;
98 struct udphdr _hdr, *hdr;
101 /* Header is too small? */
102 hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
104 if (LOG_INVALID(IPPROTO_UDPLITE))
105 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
106 "nf_ct_udplite: short packet ");
110 cscov = ntohs(hdr->len);
113 else if (cscov < sizeof(*hdr) || cscov > udplen) {
114 if (LOG_INVALID(IPPROTO_UDPLITE))
115 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
116 "nf_ct_udplite: invalid checksum coverage ");
120 /* UDPLITE mandates checksums */
122 if (LOG_INVALID(IPPROTO_UDPLITE))
123 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
124 "nf_ct_udplite: checksum missing ");
128 /* Checksum invalid? Ignore. */
129 if (nf_conntrack_checksum && !skb_csum_unnecessary(skb) &&
130 hooknum == NF_INET_PRE_ROUTING) {
132 struct iphdr *iph = ip_hdr(skb);
134 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
135 udplen, IPPROTO_UDPLITE, 0);
137 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
138 __wsum hsum = skb_checksum(skb, 0, dataoff, 0);
140 skb->csum = ~csum_unfold(
141 csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
142 udplen, IPPROTO_UDPLITE,
146 skb->ip_summed = CHECKSUM_NONE;
147 if (__skb_checksum_complete_head(skb, dataoff + cscov)) {
148 if (LOG_INVALID(IPPROTO_UDPLITE))
149 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
150 "nf_ct_udplite: bad UDPLite "
154 skb->ip_summed = CHECKSUM_UNNECESSARY;
161 static unsigned int udplite_sysctl_table_users;
162 static struct ctl_table_header *udplite_sysctl_header;
163 static struct ctl_table udplite_sysctl_table[] = {
165 .ctl_name = CTL_UNNUMBERED,
166 .procname = "nf_conntrack_udplite_timeout",
167 .data = &nf_ct_udplite_timeout,
168 .maxlen = sizeof(unsigned int),
170 .proc_handler = &proc_dointvec_jiffies,
173 .ctl_name = CTL_UNNUMBERED,
174 .procname = "nf_conntrack_udplite_timeout_stream",
175 .data = &nf_ct_udplite_timeout_stream,
176 .maxlen = sizeof(unsigned int),
178 .proc_handler = &proc_dointvec_jiffies,
184 #endif /* CONFIG_SYSCTL */
186 static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite4 __read_mostly =
189 .l4proto = IPPROTO_UDPLITE,
191 .pkt_to_tuple = udplite_pkt_to_tuple,
192 .invert_tuple = udplite_invert_tuple,
193 .print_tuple = udplite_print_tuple,
194 .packet = udplite_packet,
196 .error = udplite_error,
197 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
198 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
199 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
200 .nla_policy = nf_ct_port_nla_policy,
203 .ctl_table_users = &udplite_sysctl_table_users,
204 .ctl_table_header = &udplite_sysctl_header,
205 .ctl_table = udplite_sysctl_table,
209 static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite6 __read_mostly =
212 .l4proto = IPPROTO_UDPLITE,
214 .pkt_to_tuple = udplite_pkt_to_tuple,
215 .invert_tuple = udplite_invert_tuple,
216 .print_tuple = udplite_print_tuple,
217 .packet = udplite_packet,
219 .error = udplite_error,
220 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
221 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
222 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
223 .nla_policy = nf_ct_port_nla_policy,
226 .ctl_table_users = &udplite_sysctl_table_users,
227 .ctl_table_header = &udplite_sysctl_header,
228 .ctl_table = udplite_sysctl_table,
232 static int __init nf_conntrack_proto_udplite_init(void)
236 err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite4);
239 err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite6);
244 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
249 static void __exit nf_conntrack_proto_udplite_exit(void)
251 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite6);
252 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
255 module_init(nf_conntrack_proto_udplite_init);
256 module_exit(nf_conntrack_proto_udplite_exit);
258 MODULE_LICENSE("GPL");