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10#include <linux/types.h>
11#include <linux/timer.h>
12#include <linux/module.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>
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>
25#include <net/netfilter/nf_log.h>
26
27static unsigned int nf_ct_udplite_timeout __read_mostly = 30*HZ;
28static unsigned int nf_ct_udplite_timeout_stream __read_mostly = 180*HZ;
29
30static bool udplite_pkt_to_tuple(const struct sk_buff *skb,
31 unsigned int dataoff,
32 struct nf_conntrack_tuple *tuple)
33{
34 const struct udphdr *hp;
35 struct udphdr _hdr;
36
37 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
38 if (hp == NULL)
39 return false;
40
41 tuple->src.u.udp.port = hp->source;
42 tuple->dst.u.udp.port = hp->dest;
43 return true;
44}
45
46static bool udplite_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 true;
52}
53
54
55static 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
63
64static int udplite_packet(struct nf_conn *ct,
65 const struct sk_buff *skb,
66 unsigned int dataoff,
67 enum ip_conntrack_info ctinfo,
68 u_int8_t pf,
69 unsigned int hooknum)
70{
71
72
73 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
74 nf_ct_refresh_acct(ct, ctinfo, skb,
75 nf_ct_udplite_timeout_stream);
76
77 if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
78 nf_conntrack_event_cache(IPCT_STATUS, ct);
79 } else
80 nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_udplite_timeout);
81
82 return NF_ACCEPT;
83}
84
85
86static bool udplite_new(struct nf_conn *ct, const struct sk_buff *skb,
87 unsigned int dataoff)
88{
89 return true;
90}
91
92static int udplite_error(struct net *net,
93 struct sk_buff *skb,
94 unsigned int dataoff,
95 enum ip_conntrack_info *ctinfo,
96 u_int8_t pf,
97 unsigned int hooknum)
98{
99 unsigned int udplen = skb->len - dataoff;
100 const struct udphdr *hdr;
101 struct udphdr _hdr;
102 unsigned int cscov;
103
104
105 hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
106 if (hdr == NULL) {
107 if (LOG_INVALID(net, IPPROTO_UDPLITE))
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) {
117 if (LOG_INVALID(net, IPPROTO_UDPLITE))
118 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
119 "nf_ct_udplite: invalid checksum coverage ");
120 return -NF_ACCEPT;
121 }
122
123
124 if (!hdr->check) {
125 if (LOG_INVALID(net, IPPROTO_UDPLITE))
126 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
127 "nf_ct_udplite: checksum missing ");
128 return -NF_ACCEPT;
129 }
130
131
132 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
133 nf_checksum_partial(skb, hooknum, dataoff, cscov, IPPROTO_UDP,
134 pf)) {
135 if (LOG_INVALID(net, IPPROTO_UDPLITE))
136 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
137 "nf_ct_udplite: bad UDPLite checksum ");
138 return -NF_ACCEPT;
139 }
140
141 return NF_ACCEPT;
142}
143
144#ifdef CONFIG_SYSCTL
145static unsigned int udplite_sysctl_table_users;
146static struct ctl_table_header *udplite_sysctl_header;
147static 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,
154 .proc_handler = proc_dointvec_jiffies,
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,
162 .proc_handler = proc_dointvec_jiffies,
163 },
164 {
165 .ctl_name = 0
166 }
167};
168#endif
169
170static 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,
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)
182 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
183 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
184 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
185 .nla_policy = nf_ct_port_nla_policy,
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
194static 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,
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)
206 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
207 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
208 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
209 .nla_policy = nf_ct_port_nla_policy,
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
218static 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;
229err2:
230 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
231err1:
232 return err;
233}
234
235static 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
241module_init(nf_conntrack_proto_udplite_init);
242module_exit(nf_conntrack_proto_udplite_exit);
243
244MODULE_LICENSE("GPL");
245
