[NETFILTER]: nf_log: move logging stuff to seperate header
[linux-2.6.git] / net / netfilter / nf_conntrack_proto_udp.c
1 /* (C) 1999-2001 Paul `Rusty' Russell
2  * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
3  *
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.
7  */
8
9 #include <linux/types.h>
10 #include <linux/timer.h>
11 #include <linux/module.h>
12 #include <linux/udp.h>
13 #include <linux/seq_file.h>
14 #include <linux/skbuff.h>
15 #include <linux/ipv6.h>
16 #include <net/ip6_checksum.h>
17 #include <net/checksum.h>
18
19 #include <linux/netfilter.h>
20 #include <linux/netfilter_ipv4.h>
21 #include <linux/netfilter_ipv6.h>
22 #include <net/netfilter/nf_conntrack_l4proto.h>
23 #include <net/netfilter/nf_conntrack_ecache.h>
24 #include <net/netfilter/nf_log.h>
25
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;
28
29 static int udp_pkt_to_tuple(const struct sk_buff *skb,
30                              unsigned int dataoff,
31                              struct nf_conntrack_tuple *tuple)
32 {
33         struct udphdr _hdr, *hp;
34
35         /* Actually only need first 8 bytes. */
36         hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
37         if (hp == NULL)
38                 return 0;
39
40         tuple->src.u.udp.port = hp->source;
41         tuple->dst.u.udp.port = hp->dest;
42
43         return 1;
44 }
45
46 static int udp_invert_tuple(struct nf_conntrack_tuple *tuple,
47                             const struct nf_conntrack_tuple *orig)
48 {
49         tuple->src.u.udp.port = orig->dst.u.udp.port;
50         tuple->dst.u.udp.port = orig->src.u.udp.port;
51         return 1;
52 }
53
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)
57 {
58         return seq_printf(s, "sport=%hu dport=%hu ",
59                           ntohs(tuple->src.u.udp.port),
60                           ntohs(tuple->dst.u.udp.port));
61 }
62
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)
66 {
67         return 0;
68 }
69
70 /* Returns verdict for packet, and may modify conntracktype */
71 static int udp_packet(struct nf_conn *conntrack,
72                       const struct sk_buff *skb,
73                       unsigned int dataoff,
74                       enum ip_conntrack_info ctinfo,
75                       int pf,
76                       unsigned int hooknum)
77 {
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);
86         } else
87                 nf_ct_refresh_acct(conntrack, ctinfo, skb, nf_ct_udp_timeout);
88
89         return NF_ACCEPT;
90 }
91
92 /* Called when a new connection for this protocol found. */
93 static int udp_new(struct nf_conn *conntrack, const struct sk_buff *skb,
94                    unsigned int dataoff)
95 {
96         return 1;
97 }
98
99 static int udp_error(struct sk_buff *skb, unsigned int dataoff,
100                      enum ip_conntrack_info *ctinfo,
101                      int pf,
102                      unsigned int hooknum)
103 {
104         unsigned int udplen = skb->len - dataoff;
105         struct udphdr _hdr, *hdr;
106
107         /* Header is too small? */
108         hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
109         if (hdr == NULL) {
110                 if (LOG_INVALID(IPPROTO_UDP))
111                         nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
112                                       "nf_ct_udp: short packet ");
113                 return -NF_ACCEPT;
114         }
115
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 ");
121                 return -NF_ACCEPT;
122         }
123
124         /* Packet with no checksum */
125         if (!hdr->check)
126                 return NF_ACCEPT;
127
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 && hooknum == NF_INET_PRE_ROUTING &&
133             nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) {
134                 if (LOG_INVALID(IPPROTO_UDP))
135                         nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
136                                 "nf_ct_udp: bad UDP checksum ");
137                 return -NF_ACCEPT;
138         }
139
140         return NF_ACCEPT;
141 }
142
143 #ifdef CONFIG_SYSCTL
144 static unsigned int udp_sysctl_table_users;
145 static struct ctl_table_header *udp_sysctl_header;
146 static struct ctl_table udp_sysctl_table[] = {
147         {
148                 .procname       = "nf_conntrack_udp_timeout",
149                 .data           = &nf_ct_udp_timeout,
150                 .maxlen         = sizeof(unsigned int),
151                 .mode           = 0644,
152                 .proc_handler   = &proc_dointvec_jiffies,
153         },
154         {
155                 .procname       = "nf_conntrack_udp_timeout_stream",
156                 .data           = &nf_ct_udp_timeout_stream,
157                 .maxlen         = sizeof(unsigned int),
158                 .mode           = 0644,
159                 .proc_handler   = &proc_dointvec_jiffies,
160         },
161         {
162                 .ctl_name       = 0
163         }
164 };
165 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
166 static struct ctl_table udp_compat_sysctl_table[] = {
167         {
168                 .procname       = "ip_conntrack_udp_timeout",
169                 .data           = &nf_ct_udp_timeout,
170                 .maxlen         = sizeof(unsigned int),
171                 .mode           = 0644,
172                 .proc_handler   = &proc_dointvec_jiffies,
173         },
174         {
175                 .procname       = "ip_conntrack_udp_timeout_stream",
176                 .data           = &nf_ct_udp_timeout_stream,
177                 .maxlen         = sizeof(unsigned int),
178                 .mode           = 0644,
179                 .proc_handler   = &proc_dointvec_jiffies,
180         },
181         {
182                 .ctl_name       = 0
183         }
184 };
185 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
186 #endif /* CONFIG_SYSCTL */
187
188 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 __read_mostly =
189 {
190         .l3proto                = PF_INET,
191         .l4proto                = IPPROTO_UDP,
192         .name                   = "udp",
193         .pkt_to_tuple           = udp_pkt_to_tuple,
194         .invert_tuple           = udp_invert_tuple,
195         .print_tuple            = udp_print_tuple,
196         .print_conntrack        = udp_print_conntrack,
197         .packet                 = udp_packet,
198         .new                    = udp_new,
199         .error                  = udp_error,
200 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
201         .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
202         .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
203         .nla_policy             = nf_ct_port_nla_policy,
204 #endif
205 #ifdef CONFIG_SYSCTL
206         .ctl_table_users        = &udp_sysctl_table_users,
207         .ctl_table_header       = &udp_sysctl_header,
208         .ctl_table              = udp_sysctl_table,
209 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
210         .ctl_compat_table       = udp_compat_sysctl_table,
211 #endif
212 #endif
213 };
214 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);
215
216 struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 __read_mostly =
217 {
218         .l3proto                = PF_INET6,
219         .l4proto                = IPPROTO_UDP,
220         .name                   = "udp",
221         .pkt_to_tuple           = udp_pkt_to_tuple,
222         .invert_tuple           = udp_invert_tuple,
223         .print_tuple            = udp_print_tuple,
224         .print_conntrack        = udp_print_conntrack,
225         .packet                 = udp_packet,
226         .new                    = udp_new,
227         .error                  = udp_error,
228 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
229         .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
230         .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
231         .nla_policy             = nf_ct_port_nla_policy,
232 #endif
233 #ifdef CONFIG_SYSCTL
234         .ctl_table_users        = &udp_sysctl_table_users,
235         .ctl_table_header       = &udp_sysctl_header,
236         .ctl_table              = udp_sysctl_table,
237 #endif
238 };
239 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6);