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9fb9cbb1 YK |
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 | * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> | |
9 | * - enable working with Layer 3 protocol independent connection tracking. | |
10 | * | |
11 | * Derived from net/ipv4/netfilter/ip_conntrack_proto_udp.c | |
12 | */ | |
13 | ||
14 | #include <linux/types.h> | |
9fb9cbb1 YK |
15 | #include <linux/timer.h> |
16 | #include <linux/module.h> | |
17 | #include <linux/netfilter.h> | |
18 | #include <linux/udp.h> | |
19 | #include <linux/seq_file.h> | |
20 | #include <linux/skbuff.h> | |
21 | #include <linux/ipv6.h> | |
22 | #include <net/ip6_checksum.h> | |
23 | #include <net/checksum.h> | |
f6180121 | 24 | |
9fb9cbb1 YK |
25 | #include <linux/netfilter.h> |
26 | #include <linux/netfilter_ipv4.h> | |
27 | #include <linux/netfilter_ipv6.h> | |
605dcad6 | 28 | #include <net/netfilter/nf_conntrack_l4proto.h> |
f6180121 | 29 | #include <net/netfilter/nf_conntrack_ecache.h> |
9fb9cbb1 | 30 | |
933a41e7 PM |
31 | static unsigned int nf_ct_udp_timeout __read_mostly = 30*HZ; |
32 | static unsigned int nf_ct_udp_timeout_stream __read_mostly = 180*HZ; | |
9fb9cbb1 YK |
33 | |
34 | static int udp_pkt_to_tuple(const struct sk_buff *skb, | |
35 | unsigned int dataoff, | |
36 | struct nf_conntrack_tuple *tuple) | |
37 | { | |
38 | struct udphdr _hdr, *hp; | |
39 | ||
40 | /* Actually only need first 8 bytes. */ | |
41 | hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); | |
42 | if (hp == NULL) | |
43 | return 0; | |
44 | ||
45 | tuple->src.u.udp.port = hp->source; | |
46 | tuple->dst.u.udp.port = hp->dest; | |
47 | ||
48 | return 1; | |
49 | } | |
50 | ||
51 | static int udp_invert_tuple(struct nf_conntrack_tuple *tuple, | |
52 | const struct nf_conntrack_tuple *orig) | |
53 | { | |
54 | tuple->src.u.udp.port = orig->dst.u.udp.port; | |
55 | tuple->dst.u.udp.port = orig->src.u.udp.port; | |
56 | return 1; | |
57 | } | |
58 | ||
59 | /* Print out the per-protocol part of the tuple. */ | |
60 | static int udp_print_tuple(struct seq_file *s, | |
61 | const struct nf_conntrack_tuple *tuple) | |
62 | { | |
63 | return seq_printf(s, "sport=%hu dport=%hu ", | |
64 | ntohs(tuple->src.u.udp.port), | |
65 | ntohs(tuple->dst.u.udp.port)); | |
66 | } | |
67 | ||
68 | /* Print out the private part of the conntrack. */ | |
69 | static int udp_print_conntrack(struct seq_file *s, | |
70 | const struct nf_conn *conntrack) | |
71 | { | |
72 | return 0; | |
73 | } | |
74 | ||
75 | /* Returns verdict for packet, and may modify conntracktype */ | |
76 | static int udp_packet(struct nf_conn *conntrack, | |
77 | const struct sk_buff *skb, | |
78 | unsigned int dataoff, | |
79 | enum ip_conntrack_info ctinfo, | |
80 | int pf, | |
81 | unsigned int hooknum) | |
82 | { | |
83 | /* If we've seen traffic both ways, this is some kind of UDP | |
84 | stream. Extend timeout. */ | |
85 | if (test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) { | |
86 | nf_ct_refresh_acct(conntrack, ctinfo, skb, | |
87 | nf_ct_udp_timeout_stream); | |
88 | /* Also, more likely to be important, and not a probe */ | |
89 | if (!test_and_set_bit(IPS_ASSURED_BIT, &conntrack->status)) | |
90 | nf_conntrack_event_cache(IPCT_STATUS, skb); | |
91 | } else | |
92 | nf_ct_refresh_acct(conntrack, ctinfo, skb, nf_ct_udp_timeout); | |
93 | ||
94 | return NF_ACCEPT; | |
95 | } | |
96 | ||
97 | /* Called when a new connection for this protocol found. */ | |
98 | static int udp_new(struct nf_conn *conntrack, const struct sk_buff *skb, | |
99 | unsigned int dataoff) | |
100 | { | |
101 | return 1; | |
102 | } | |
103 | ||
104 | static int udp_error(struct sk_buff *skb, unsigned int dataoff, | |
105 | enum ip_conntrack_info *ctinfo, | |
106 | int pf, | |
96f6bf82 | 107 | unsigned int hooknum) |
9fb9cbb1 YK |
108 | { |
109 | unsigned int udplen = skb->len - dataoff; | |
110 | struct udphdr _hdr, *hdr; | |
111 | ||
112 | /* Header is too small? */ | |
113 | hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); | |
114 | if (hdr == NULL) { | |
115 | if (LOG_INVALID(IPPROTO_UDP)) | |
116 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, | |
117 | "nf_ct_udp: short packet "); | |
118 | return -NF_ACCEPT; | |
119 | } | |
120 | ||
121 | /* Truncated/malformed packets */ | |
122 | if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) { | |
123 | if (LOG_INVALID(IPPROTO_UDP)) | |
124 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, | |
125 | "nf_ct_udp: truncated/malformed packet "); | |
126 | return -NF_ACCEPT; | |
127 | } | |
128 | ||
129 | /* Packet with no checksum */ | |
130 | if (!hdr->check) | |
131 | return NF_ACCEPT; | |
132 | ||
133 | /* Checksum invalid? Ignore. | |
134 | * We skip checking packets on the outgoing path | |
84fa7933 | 135 | * because the checksum is assumed to be correct. |
9fb9cbb1 | 136 | * FIXME: Source route IP option packets --RR */ |
39a27a35 PM |
137 | if (nf_conntrack_checksum && |
138 | ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) || | |
96f6bf82 PM |
139 | (pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING)) && |
140 | nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) { | |
9fb9cbb1 YK |
141 | if (LOG_INVALID(IPPROTO_UDP)) |
142 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, | |
143 | "nf_ct_udp: bad UDP checksum "); | |
144 | return -NF_ACCEPT; | |
145 | } | |
146 | ||
147 | return NF_ACCEPT; | |
148 | } | |
149 | ||
933a41e7 PM |
150 | #ifdef CONFIG_SYSCTL |
151 | static unsigned int udp_sysctl_table_users; | |
152 | static struct ctl_table_header *udp_sysctl_header; | |
153 | static struct ctl_table udp_sysctl_table[] = { | |
154 | { | |
155 | .ctl_name = NET_NF_CONNTRACK_UDP_TIMEOUT, | |
156 | .procname = "nf_conntrack_udp_timeout", | |
157 | .data = &nf_ct_udp_timeout, | |
158 | .maxlen = sizeof(unsigned int), | |
159 | .mode = 0644, | |
160 | .proc_handler = &proc_dointvec_jiffies, | |
161 | }, | |
162 | { | |
163 | .ctl_name = NET_NF_CONNTRACK_UDP_TIMEOUT_STREAM, | |
164 | .procname = "nf_conntrack_udp_timeout_stream", | |
165 | .data = &nf_ct_udp_timeout_stream, | |
166 | .maxlen = sizeof(unsigned int), | |
167 | .mode = 0644, | |
168 | .proc_handler = &proc_dointvec_jiffies, | |
169 | }, | |
170 | { | |
171 | .ctl_name = 0 | |
172 | } | |
173 | }; | |
a999e683 PM |
174 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
175 | static struct ctl_table udp_compat_sysctl_table[] = { | |
176 | { | |
177 | .ctl_name = NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT, | |
178 | .procname = "ip_conntrack_udp_timeout", | |
179 | .data = &nf_ct_udp_timeout, | |
180 | .maxlen = sizeof(unsigned int), | |
181 | .mode = 0644, | |
182 | .proc_handler = &proc_dointvec_jiffies, | |
183 | }, | |
184 | { | |
185 | .ctl_name = NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT_STREAM, | |
186 | .procname = "ip_conntrack_udp_timeout_stream", | |
187 | .data = &nf_ct_udp_timeout_stream, | |
188 | .maxlen = sizeof(unsigned int), | |
189 | .mode = 0644, | |
190 | .proc_handler = &proc_dointvec_jiffies, | |
191 | }, | |
192 | { | |
193 | .ctl_name = 0 | |
194 | } | |
195 | }; | |
196 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
933a41e7 PM |
197 | #endif /* CONFIG_SYSCTL */ |
198 | ||
605dcad6 | 199 | struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 = |
9fb9cbb1 YK |
200 | { |
201 | .l3proto = PF_INET, | |
605dcad6 | 202 | .l4proto = IPPROTO_UDP, |
9fb9cbb1 YK |
203 | .name = "udp", |
204 | .pkt_to_tuple = udp_pkt_to_tuple, | |
205 | .invert_tuple = udp_invert_tuple, | |
206 | .print_tuple = udp_print_tuple, | |
207 | .print_conntrack = udp_print_conntrack, | |
208 | .packet = udp_packet, | |
209 | .new = udp_new, | |
96f6bf82 | 210 | .error = udp_error, |
e281db5c | 211 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
c1d10adb PNA |
212 | .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr, |
213 | .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple, | |
214 | #endif | |
933a41e7 PM |
215 | #ifdef CONFIG_SYSCTL |
216 | .ctl_table_users = &udp_sysctl_table_users, | |
217 | .ctl_table_header = &udp_sysctl_header, | |
218 | .ctl_table = udp_sysctl_table, | |
a999e683 PM |
219 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
220 | .ctl_compat_table = udp_compat_sysctl_table, | |
221 | #endif | |
933a41e7 | 222 | #endif |
9fb9cbb1 | 223 | }; |
13b18339 | 224 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4); |
9fb9cbb1 | 225 | |
605dcad6 | 226 | struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 = |
9fb9cbb1 YK |
227 | { |
228 | .l3proto = PF_INET6, | |
605dcad6 | 229 | .l4proto = IPPROTO_UDP, |
9fb9cbb1 YK |
230 | .name = "udp", |
231 | .pkt_to_tuple = udp_pkt_to_tuple, | |
232 | .invert_tuple = udp_invert_tuple, | |
233 | .print_tuple = udp_print_tuple, | |
234 | .print_conntrack = udp_print_conntrack, | |
235 | .packet = udp_packet, | |
236 | .new = udp_new, | |
96f6bf82 | 237 | .error = udp_error, |
e281db5c | 238 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
c1d10adb PNA |
239 | .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr, |
240 | .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple, | |
241 | #endif | |
933a41e7 PM |
242 | #ifdef CONFIG_SYSCTL |
243 | .ctl_table_users = &udp_sysctl_table_users, | |
244 | .ctl_table_header = &udp_sysctl_header, | |
245 | .ctl_table = udp_sysctl_table, | |
246 | #endif | |
9fb9cbb1 | 247 | }; |
13b18339 | 248 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6); |