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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. | |
9fb9cbb1 YK |
7 | */ |
8 | ||
9 | #include <linux/types.h> | |
9fb9cbb1 YK |
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> | |
f6180121 | 19 | |
9fb9cbb1 YK |
20 | #include <linux/netfilter.h> |
21 | #include <linux/netfilter_ipv4.h> | |
22 | #include <linux/netfilter_ipv6.h> | |
605dcad6 | 23 | #include <net/netfilter/nf_conntrack_l4proto.h> |
f6180121 | 24 | #include <net/netfilter/nf_conntrack_ecache.h> |
9fb9cbb1 | 25 | |
933a41e7 PM |
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; | |
9fb9cbb1 YK |
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, | |
96f6bf82 | 102 | unsigned int hooknum) |
9fb9cbb1 YK |
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 | |
84fa7933 | 130 | * because the checksum is assumed to be correct. |
9fb9cbb1 | 131 | * FIXME: Source route IP option packets --RR */ |
39a27a35 PM |
132 | if (nf_conntrack_checksum && |
133 | ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) || | |
96f6bf82 PM |
134 | (pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING)) && |
135 | nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) { | |
9fb9cbb1 YK |
136 | if (LOG_INVALID(IPPROTO_UDP)) |
137 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, | |
138 | "nf_ct_udp: bad UDP checksum "); | |
139 | return -NF_ACCEPT; | |
140 | } | |
141 | ||
142 | return NF_ACCEPT; | |
143 | } | |
144 | ||
933a41e7 PM |
145 | #ifdef CONFIG_SYSCTL |
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[] = { | |
149 | { | |
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), | |
154 | .mode = 0644, | |
155 | .proc_handler = &proc_dointvec_jiffies, | |
156 | }, | |
157 | { | |
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), | |
162 | .mode = 0644, | |
163 | .proc_handler = &proc_dointvec_jiffies, | |
164 | }, | |
165 | { | |
166 | .ctl_name = 0 | |
167 | } | |
168 | }; | |
a999e683 PM |
169 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
170 | static struct ctl_table udp_compat_sysctl_table[] = { | |
171 | { | |
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), | |
176 | .mode = 0644, | |
177 | .proc_handler = &proc_dointvec_jiffies, | |
178 | }, | |
179 | { | |
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), | |
184 | .mode = 0644, | |
185 | .proc_handler = &proc_dointvec_jiffies, | |
186 | }, | |
187 | { | |
188 | .ctl_name = 0 | |
189 | } | |
190 | }; | |
191 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ | |
933a41e7 PM |
192 | #endif /* CONFIG_SYSCTL */ |
193 | ||
605dcad6 | 194 | struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 = |
9fb9cbb1 YK |
195 | { |
196 | .l3proto = PF_INET, | |
605dcad6 | 197 | .l4proto = IPPROTO_UDP, |
9fb9cbb1 YK |
198 | .name = "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, | |
204 | .new = udp_new, | |
96f6bf82 | 205 | .error = udp_error, |
e281db5c | 206 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
c1d10adb PNA |
207 | .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr, |
208 | .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple, | |
209 | #endif | |
933a41e7 PM |
210 | #ifdef CONFIG_SYSCTL |
211 | .ctl_table_users = &udp_sysctl_table_users, | |
212 | .ctl_table_header = &udp_sysctl_header, | |
213 | .ctl_table = udp_sysctl_table, | |
a999e683 PM |
214 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
215 | .ctl_compat_table = udp_compat_sysctl_table, | |
216 | #endif | |
933a41e7 | 217 | #endif |
9fb9cbb1 | 218 | }; |
13b18339 | 219 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4); |
9fb9cbb1 | 220 | |
605dcad6 | 221 | struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 = |
9fb9cbb1 YK |
222 | { |
223 | .l3proto = PF_INET6, | |
605dcad6 | 224 | .l4proto = IPPROTO_UDP, |
9fb9cbb1 YK |
225 | .name = "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, | |
231 | .new = udp_new, | |
96f6bf82 | 232 | .error = udp_error, |
e281db5c | 233 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
c1d10adb PNA |
234 | .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr, |
235 | .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple, | |
236 | #endif | |
933a41e7 PM |
237 | #ifdef CONFIG_SYSCTL |
238 | .ctl_table_users = &udp_sysctl_table_users, | |
239 | .ctl_table_header = &udp_sysctl_header, | |
240 | .ctl_table = udp_sysctl_table, | |
241 | #endif | |
9fb9cbb1 | 242 | }; |
13b18339 | 243 | EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6); |