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 *ct,
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, &ct->status)) {
73 nf_ct_refresh_acct(ct, 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, &ct->status))
77 nf_conntrack_event_cache(IPCT_STATUS, skb);
79 nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_udplite_timeout);
84 /* Called when a new connection for this protocol found. */
85 static int udplite_new(struct nf_conn *ct, const struct sk_buff *skb,
91 static int udplite_error(struct sk_buff *skb, unsigned int dataoff,
92 enum ip_conntrack_info *ctinfo,
96 unsigned int udplen = skb->len - dataoff;
97 struct udphdr _hdr, *hdr;
100 /* Header is too small? */
101 hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
103 if (LOG_INVALID(IPPROTO_UDPLITE))
104 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
105 "nf_ct_udplite: short packet ");
109 cscov = ntohs(hdr->len);
112 else if (cscov < sizeof(*hdr) || cscov > udplen) {
113 if (LOG_INVALID(IPPROTO_UDPLITE))
114 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
115 "nf_ct_udplite: invalid checksum coverage ");
119 /* UDPLITE mandates checksums */
121 if (LOG_INVALID(IPPROTO_UDPLITE))
122 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
123 "nf_ct_udplite: checksum missing ");
127 /* Checksum invalid? Ignore. */
128 if (nf_conntrack_checksum && !skb_csum_unnecessary(skb) &&
129 hooknum == NF_INET_PRE_ROUTING) {
131 struct iphdr *iph = ip_hdr(skb);
133 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
134 udplen, IPPROTO_UDPLITE, 0);
136 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
137 __wsum hsum = skb_checksum(skb, 0, dataoff, 0);
139 skb->csum = ~csum_unfold(
140 csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
141 udplen, IPPROTO_UDPLITE,
145 skb->ip_summed = CHECKSUM_NONE;
146 if (__skb_checksum_complete_head(skb, dataoff + cscov)) {
147 if (LOG_INVALID(IPPROTO_UDPLITE))
148 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
149 "nf_ct_udplite: bad UDPLite "
153 skb->ip_summed = CHECKSUM_UNNECESSARY;
160 static unsigned int udplite_sysctl_table_users;
161 static struct ctl_table_header *udplite_sysctl_header;
162 static struct ctl_table udplite_sysctl_table[] = {
164 .ctl_name = CTL_UNNUMBERED,
165 .procname = "nf_conntrack_udplite_timeout",
166 .data = &nf_ct_udplite_timeout,
167 .maxlen = sizeof(unsigned int),
169 .proc_handler = &proc_dointvec_jiffies,
172 .ctl_name = CTL_UNNUMBERED,
173 .procname = "nf_conntrack_udplite_timeout_stream",
174 .data = &nf_ct_udplite_timeout_stream,
175 .maxlen = sizeof(unsigned int),
177 .proc_handler = &proc_dointvec_jiffies,
183 #endif /* CONFIG_SYSCTL */
185 static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite4 __read_mostly =
188 .l4proto = IPPROTO_UDPLITE,
190 .pkt_to_tuple = udplite_pkt_to_tuple,
191 .invert_tuple = udplite_invert_tuple,
192 .print_tuple = udplite_print_tuple,
193 .packet = udplite_packet,
195 .error = udplite_error,
196 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
197 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
198 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
199 .nla_policy = nf_ct_port_nla_policy,
202 .ctl_table_users = &udplite_sysctl_table_users,
203 .ctl_table_header = &udplite_sysctl_header,
204 .ctl_table = udplite_sysctl_table,
208 static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite6 __read_mostly =
211 .l4proto = IPPROTO_UDPLITE,
213 .pkt_to_tuple = udplite_pkt_to_tuple,
214 .invert_tuple = udplite_invert_tuple,
215 .print_tuple = udplite_print_tuple,
216 .packet = udplite_packet,
218 .error = udplite_error,
219 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
220 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
221 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
222 .nla_policy = nf_ct_port_nla_policy,
225 .ctl_table_users = &udplite_sysctl_table_users,
226 .ctl_table_header = &udplite_sysctl_header,
227 .ctl_table = udplite_sysctl_table,
231 static int __init nf_conntrack_proto_udplite_init(void)
235 err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite4);
238 err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite6);
243 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
248 static void __exit nf_conntrack_proto_udplite_exit(void)
250 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite6);
251 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
254 module_init(nf_conntrack_proto_udplite_init);
255 module_exit(nf_conntrack_proto_udplite_exit);
257 MODULE_LICENSE("GPL");