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59eecdfb PM |
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> | |
4 | * | |
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. | |
8 | */ | |
9 | ||
10 | #include <linux/types.h> | |
11 | #include <linux/timer.h> | |
12 | #include <linux/module.h> | |
59eecdfb PM |
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> | |
19 | ||
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> | |
f01ffbd6 | 25 | #include <net/netfilter/nf_log.h> |
59eecdfb PM |
26 | |
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; | |
29 | ||
09f263cd JE |
30 | static bool udplite_pkt_to_tuple(const struct sk_buff *skb, |
31 | unsigned int dataoff, | |
32 | struct nf_conntrack_tuple *tuple) | |
59eecdfb | 33 | { |
da3f13c9 JE |
34 | const struct udphdr *hp; |
35 | struct udphdr _hdr; | |
59eecdfb PM |
36 | |
37 | hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); | |
38 | if (hp == NULL) | |
09f263cd | 39 | return false; |
59eecdfb PM |
40 | |
41 | tuple->src.u.udp.port = hp->source; | |
42 | tuple->dst.u.udp.port = hp->dest; | |
09f263cd | 43 | return true; |
59eecdfb PM |
44 | } |
45 | ||
09f263cd JE |
46 | static bool udplite_invert_tuple(struct nf_conntrack_tuple *tuple, |
47 | const struct nf_conntrack_tuple *orig) | |
59eecdfb PM |
48 | { |
49 | tuple->src.u.udp.port = orig->dst.u.udp.port; | |
50 | tuple->dst.u.udp.port = orig->src.u.udp.port; | |
09f263cd | 51 | return true; |
59eecdfb PM |
52 | } |
53 | ||
54 | /* Print out the per-protocol part of the tuple. */ | |
55 | static int udplite_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 | ||
59eecdfb | 63 | /* Returns verdict for packet, and may modify conntracktype */ |
c88130bc | 64 | static int udplite_packet(struct nf_conn *ct, |
59eecdfb PM |
65 | const struct sk_buff *skb, |
66 | unsigned int dataoff, | |
67 | enum ip_conntrack_info ctinfo, | |
76108cea | 68 | u_int8_t pf, |
59eecdfb PM |
69 | unsigned int hooknum) |
70 | { | |
71 | /* If we've seen traffic both ways, this is some kind of UDP | |
72 | stream. Extend timeout. */ | |
c88130bc PM |
73 | if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { |
74 | nf_ct_refresh_acct(ct, ctinfo, skb, | |
59eecdfb PM |
75 | nf_ct_udplite_timeout_stream); |
76 | /* Also, more likely to be important, and not a probe */ | |
c88130bc | 77 | if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status)) |
a71996fc | 78 | nf_conntrack_event_cache(IPCT_STATUS, ct); |
59eecdfb | 79 | } else |
c88130bc | 80 | nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_udplite_timeout); |
59eecdfb PM |
81 | |
82 | return NF_ACCEPT; | |
83 | } | |
84 | ||
85 | /* Called when a new connection for this protocol found. */ | |
09f263cd JE |
86 | static bool udplite_new(struct nf_conn *ct, const struct sk_buff *skb, |
87 | unsigned int dataoff) | |
59eecdfb | 88 | { |
09f263cd | 89 | return true; |
59eecdfb PM |
90 | } |
91 | ||
74c51a14 AD |
92 | static int udplite_error(struct net *net, |
93 | struct sk_buff *skb, | |
94 | unsigned int dataoff, | |
59eecdfb | 95 | enum ip_conntrack_info *ctinfo, |
76108cea | 96 | u_int8_t pf, |
59eecdfb PM |
97 | unsigned int hooknum) |
98 | { | |
99 | unsigned int udplen = skb->len - dataoff; | |
da3f13c9 JE |
100 | const struct udphdr *hdr; |
101 | struct udphdr _hdr; | |
59eecdfb PM |
102 | unsigned int cscov; |
103 | ||
104 | /* Header is too small? */ | |
105 | hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); | |
106 | if (hdr == NULL) { | |
c2a2c7e0 | 107 | if (LOG_INVALID(net, IPPROTO_UDPLITE)) |
59eecdfb PM |
108 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, |
109 | "nf_ct_udplite: short packet "); | |
110 | return -NF_ACCEPT; | |
111 | } | |
112 | ||
113 | cscov = ntohs(hdr->len); | |
114 | if (cscov == 0) | |
115 | cscov = udplen; | |
116 | else if (cscov < sizeof(*hdr) || cscov > udplen) { | |
c2a2c7e0 | 117 | if (LOG_INVALID(net, IPPROTO_UDPLITE)) |
59eecdfb PM |
118 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, |
119 | "nf_ct_udplite: invalid checksum coverage "); | |
120 | return -NF_ACCEPT; | |
121 | } | |
122 | ||
123 | /* UDPLITE mandates checksums */ | |
124 | if (!hdr->check) { | |
c2a2c7e0 | 125 | if (LOG_INVALID(net, IPPROTO_UDPLITE)) |
59eecdfb PM |
126 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, |
127 | "nf_ct_udplite: checksum missing "); | |
128 | return -NF_ACCEPT; | |
129 | } | |
130 | ||
131 | /* Checksum invalid? Ignore. */ | |
c04d0552 | 132 | if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING && |
d63a6507 PM |
133 | nf_checksum_partial(skb, hooknum, dataoff, cscov, IPPROTO_UDP, |
134 | pf)) { | |
c2a2c7e0 | 135 | if (LOG_INVALID(net, IPPROTO_UDPLITE)) |
d63a6507 PM |
136 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, |
137 | "nf_ct_udplite: bad UDPLite checksum "); | |
138 | return -NF_ACCEPT; | |
59eecdfb PM |
139 | } |
140 | ||
141 | return NF_ACCEPT; | |
142 | } | |
143 | ||
144 | #ifdef CONFIG_SYSCTL | |
145 | static unsigned int udplite_sysctl_table_users; | |
146 | static struct ctl_table_header *udplite_sysctl_header; | |
147 | static struct ctl_table udplite_sysctl_table[] = { | |
148 | { | |
149 | .ctl_name = CTL_UNNUMBERED, | |
150 | .procname = "nf_conntrack_udplite_timeout", | |
151 | .data = &nf_ct_udplite_timeout, | |
152 | .maxlen = sizeof(unsigned int), | |
153 | .mode = 0644, | |
6d9f239a | 154 | .proc_handler = proc_dointvec_jiffies, |
59eecdfb PM |
155 | }, |
156 | { | |
157 | .ctl_name = CTL_UNNUMBERED, | |
158 | .procname = "nf_conntrack_udplite_timeout_stream", | |
159 | .data = &nf_ct_udplite_timeout_stream, | |
160 | .maxlen = sizeof(unsigned int), | |
161 | .mode = 0644, | |
6d9f239a | 162 | .proc_handler = proc_dointvec_jiffies, |
59eecdfb PM |
163 | }, |
164 | { | |
165 | .ctl_name = 0 | |
166 | } | |
167 | }; | |
168 | #endif /* CONFIG_SYSCTL */ | |
169 | ||
170 | static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite4 __read_mostly = | |
171 | { | |
172 | .l3proto = PF_INET, | |
173 | .l4proto = IPPROTO_UDPLITE, | |
174 | .name = "udplite", | |
175 | .pkt_to_tuple = udplite_pkt_to_tuple, | |
176 | .invert_tuple = udplite_invert_tuple, | |
177 | .print_tuple = udplite_print_tuple, | |
59eecdfb PM |
178 | .packet = udplite_packet, |
179 | .new = udplite_new, | |
180 | .error = udplite_error, | |
181 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) | |
fdf70832 | 182 | .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, |
a400c30e | 183 | .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size, |
fdf70832 | 184 | .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, |
f73e924c | 185 | .nla_policy = nf_ct_port_nla_policy, |
59eecdfb PM |
186 | #endif |
187 | #ifdef CONFIG_SYSCTL | |
188 | .ctl_table_users = &udplite_sysctl_table_users, | |
189 | .ctl_table_header = &udplite_sysctl_header, | |
190 | .ctl_table = udplite_sysctl_table, | |
191 | #endif | |
192 | }; | |
193 | ||
194 | static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite6 __read_mostly = | |
195 | { | |
196 | .l3proto = PF_INET6, | |
197 | .l4proto = IPPROTO_UDPLITE, | |
198 | .name = "udplite", | |
199 | .pkt_to_tuple = udplite_pkt_to_tuple, | |
200 | .invert_tuple = udplite_invert_tuple, | |
201 | .print_tuple = udplite_print_tuple, | |
59eecdfb PM |
202 | .packet = udplite_packet, |
203 | .new = udplite_new, | |
204 | .error = udplite_error, | |
205 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) | |
fdf70832 | 206 | .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, |
5ff48294 | 207 | .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size, |
fdf70832 | 208 | .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, |
f73e924c | 209 | .nla_policy = nf_ct_port_nla_policy, |
59eecdfb PM |
210 | #endif |
211 | #ifdef CONFIG_SYSCTL | |
212 | .ctl_table_users = &udplite_sysctl_table_users, | |
213 | .ctl_table_header = &udplite_sysctl_header, | |
214 | .ctl_table = udplite_sysctl_table, | |
215 | #endif | |
216 | }; | |
217 | ||
218 | static int __init nf_conntrack_proto_udplite_init(void) | |
219 | { | |
220 | int err; | |
221 | ||
222 | err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite4); | |
223 | if (err < 0) | |
224 | goto err1; | |
225 | err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite6); | |
226 | if (err < 0) | |
227 | goto err2; | |
228 | return 0; | |
229 | err2: | |
230 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4); | |
231 | err1: | |
232 | return err; | |
233 | } | |
234 | ||
235 | static void __exit nf_conntrack_proto_udplite_exit(void) | |
236 | { | |
237 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite6); | |
238 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4); | |
239 | } | |
240 | ||
241 | module_init(nf_conntrack_proto_udplite_init); | |
242 | module_exit(nf_conntrack_proto_udplite_exit); | |
243 | ||
244 | MODULE_LICENSE("GPL"); |