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/timer.h>
11 #include <linux/module.h>
12 #include <linux/netfilter.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>
26 static unsigned int nf_ct_udp_timeout __read_mostly = 30*HZ;
27 static unsigned int nf_ct_udp_timeout_stream __read_mostly = 180*HZ;
29 static int udp_pkt_to_tuple(const struct sk_buff *skb,
31 struct nf_conntrack_tuple *tuple)
33 struct udphdr _hdr, *hp;
35 /* Actually only need first 8 bytes. */
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;
46 static int udp_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 udp_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 /* Print out the private part of the conntrack. */
64 static int udp_print_conntrack(struct seq_file *s,
65 const struct nf_conn *conntrack)
70 /* Returns verdict for packet, and may modify conntracktype */
71 static int udp_packet(struct nf_conn *conntrack,
72 const struct sk_buff *skb,
74 enum ip_conntrack_info ctinfo,
78 /* If we've seen traffic both ways, this is some kind of UDP
79 stream. Extend timeout. */
80 if (test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) {
81 nf_ct_refresh_acct(conntrack, ctinfo, skb,
82 nf_ct_udp_timeout_stream);
83 /* Also, more likely to be important, and not a probe */
84 if (!test_and_set_bit(IPS_ASSURED_BIT, &conntrack->status))
85 nf_conntrack_event_cache(IPCT_STATUS, skb);
87 nf_ct_refresh_acct(conntrack, ctinfo, skb, nf_ct_udp_timeout);
92 /* Called when a new connection for this protocol found. */
93 static int udp_new(struct nf_conn *conntrack, const struct sk_buff *skb,
99 static int udp_error(struct sk_buff *skb, unsigned int dataoff,
100 enum ip_conntrack_info *ctinfo,
102 unsigned int hooknum)
104 unsigned int udplen = skb->len - dataoff;
105 struct udphdr _hdr, *hdr;
107 /* Header is too small? */
108 hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
110 if (LOG_INVALID(IPPROTO_UDP))
111 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
112 "nf_ct_udp: short packet ");
116 /* Truncated/malformed packets */
117 if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) {
118 if (LOG_INVALID(IPPROTO_UDP))
119 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
120 "nf_ct_udp: truncated/malformed packet ");
124 /* Packet with no checksum */
128 /* Checksum invalid? Ignore.
129 * We skip checking packets on the outgoing path
130 * because the checksum is assumed to be correct.
131 * FIXME: Source route IP option packets --RR */
132 if (nf_conntrack_checksum &&
133 ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) ||
134 (pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING)) &&
135 nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) {
136 if (LOG_INVALID(IPPROTO_UDP))
137 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
138 "nf_ct_udp: bad UDP checksum ");
146 static unsigned int udp_sysctl_table_users;
147 static struct ctl_table_header *udp_sysctl_header;
148 static struct ctl_table udp_sysctl_table[] = {
150 .ctl_name = NET_NF_CONNTRACK_UDP_TIMEOUT,
151 .procname = "nf_conntrack_udp_timeout",
152 .data = &nf_ct_udp_timeout,
153 .maxlen = sizeof(unsigned int),
155 .proc_handler = &proc_dointvec_jiffies,
158 .ctl_name = NET_NF_CONNTRACK_UDP_TIMEOUT_STREAM,
159 .procname = "nf_conntrack_udp_timeout_stream",
160 .data = &nf_ct_udp_timeout_stream,
161 .maxlen = sizeof(unsigned int),
163 .proc_handler = &proc_dointvec_jiffies,
169 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
170 static struct ctl_table udp_compat_sysctl_table[] = {
172 .ctl_name = NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT,
173 .procname = "ip_conntrack_udp_timeout",
174 .data = &nf_ct_udp_timeout,
175 .maxlen = sizeof(unsigned int),
177 .proc_handler = &proc_dointvec_jiffies,
180 .ctl_name = NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT_STREAM,
181 .procname = "ip_conntrack_udp_timeout_stream",
182 .data = &nf_ct_udp_timeout_stream,
183 .maxlen = sizeof(unsigned int),
185 .proc_handler = &proc_dointvec_jiffies,
191 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
192 #endif /* CONFIG_SYSCTL */
194 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 =
197 .l4proto = IPPROTO_UDP,
199 .pkt_to_tuple = udp_pkt_to_tuple,
200 .invert_tuple = udp_invert_tuple,
201 .print_tuple = udp_print_tuple,
202 .print_conntrack = udp_print_conntrack,
203 .packet = udp_packet,
206 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
207 .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr,
208 .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple,
211 .ctl_table_users = &udp_sysctl_table_users,
212 .ctl_table_header = &udp_sysctl_header,
213 .ctl_table = udp_sysctl_table,
214 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
215 .ctl_compat_table = udp_compat_sysctl_table,
219 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);
221 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 =
224 .l4proto = IPPROTO_UDP,
226 .pkt_to_tuple = udp_pkt_to_tuple,
227 .invert_tuple = udp_invert_tuple,
228 .print_tuple = udp_print_tuple,
229 .print_conntrack = udp_print_conntrack,
230 .packet = udp_packet,
233 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
234 .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr,
235 .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple,
238 .ctl_table_users = &udp_sysctl_table_users,
239 .ctl_table_header = &udp_sysctl_header,
240 .ctl_table = udp_sysctl_table,
243 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6);