sctp: do not leak chunks that are sent to unconfirmed paths
[linux-2.6-block.git] / net / netfilter / nf_conntrack_proto_udp.c
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1/* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
f229f6ce 3 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
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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.
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8 */
9
10#include <linux/types.h>
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11#include <linux/timer.h>
12#include <linux/module.h>
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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
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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>
f01ffbd6 25#include <net/netfilter/nf_log.h>
9d2493f8
CP
26#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
27#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
9fb9cbb1 28
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29static unsigned int udp_timeouts[UDP_CT_MAX] = {
30 [UDP_CT_UNREPLIED] = 30*HZ,
31 [UDP_CT_REPLIED] = 180*HZ,
32};
9fb9cbb1 33
0ce490ad
G
34static inline struct nf_udp_net *udp_pernet(struct net *net)
35{
36 return &net->ct.nf_ct_proto.udp;
37}
38
09f263cd 39static bool udp_pkt_to_tuple(const struct sk_buff *skb,
9fb9cbb1 40 unsigned int dataoff,
a31f1adc 41 struct net *net,
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42 struct nf_conntrack_tuple *tuple)
43{
da3f13c9
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44 const struct udphdr *hp;
45 struct udphdr _hdr;
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46
47 /* Actually only need first 8 bytes. */
48 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
49 if (hp == NULL)
09f263cd 50 return false;
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51
52 tuple->src.u.udp.port = hp->source;
53 tuple->dst.u.udp.port = hp->dest;
54
09f263cd 55 return true;
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56}
57
09f263cd
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58static bool udp_invert_tuple(struct nf_conntrack_tuple *tuple,
59 const struct nf_conntrack_tuple *orig)
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60{
61 tuple->src.u.udp.port = orig->dst.u.udp.port;
62 tuple->dst.u.udp.port = orig->src.u.udp.port;
09f263cd 63 return true;
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64}
65
66/* Print out the per-protocol part of the tuple. */
824f1fbe
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67static void udp_print_tuple(struct seq_file *s,
68 const struct nf_conntrack_tuple *tuple)
9fb9cbb1 69{
824f1fbe
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70 seq_printf(s, "sport=%hu dport=%hu ",
71 ntohs(tuple->src.u.udp.port),
72 ntohs(tuple->dst.u.udp.port));
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73}
74
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75static unsigned int *udp_get_timeouts(struct net *net)
76{
0ce490ad 77 return udp_pernet(net)->timeouts;
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78}
79
9fb9cbb1 80/* Returns verdict for packet, and may modify conntracktype */
c88130bc 81static int udp_packet(struct nf_conn *ct,
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82 const struct sk_buff *skb,
83 unsigned int dataoff,
84 enum ip_conntrack_info ctinfo,
76108cea 85 u_int8_t pf,
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86 unsigned int hooknum,
87 unsigned int *timeouts)
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88{
89 /* If we've seen traffic both ways, this is some kind of UDP
90 stream. Extend timeout. */
c88130bc 91 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
5a41db94 92 nf_ct_refresh_acct(ct, ctinfo, skb,
2c8503f5 93 timeouts[UDP_CT_REPLIED]);
9fb9cbb1 94 /* Also, more likely to be important, and not a probe */
c88130bc 95 if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
858b3133 96 nf_conntrack_event_cache(IPCT_ASSURED, ct);
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97 } else {
98 nf_ct_refresh_acct(ct, ctinfo, skb,
2c8503f5 99 timeouts[UDP_CT_UNREPLIED]);
5a41db94 100 }
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101 return NF_ACCEPT;
102}
103
104/* Called when a new connection for this protocol found. */
09f263cd 105static bool udp_new(struct nf_conn *ct, const struct sk_buff *skb,
2c8503f5 106 unsigned int dataoff, unsigned int *timeouts)
9fb9cbb1 107{
09f263cd 108 return true;
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109}
110
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111static int udp_error(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
112 unsigned int dataoff, enum ip_conntrack_info *ctinfo,
76108cea 113 u_int8_t pf,
96f6bf82 114 unsigned int hooknum)
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115{
116 unsigned int udplen = skb->len - dataoff;
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117 const struct udphdr *hdr;
118 struct udphdr _hdr;
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119
120 /* Header is too small? */
121 hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
122 if (hdr == NULL) {
c2a2c7e0 123 if (LOG_INVALID(net, IPPROTO_UDP))
30e0c6a6 124 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
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125 "nf_ct_udp: short packet ");
126 return -NF_ACCEPT;
127 }
128
129 /* Truncated/malformed packets */
130 if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) {
c2a2c7e0 131 if (LOG_INVALID(net, IPPROTO_UDP))
30e0c6a6 132 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
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133 "nf_ct_udp: truncated/malformed packet ");
134 return -NF_ACCEPT;
135 }
136
137 /* Packet with no checksum */
138 if (!hdr->check)
139 return NF_ACCEPT;
140
141 /* Checksum invalid? Ignore.
142 * We skip checking packets on the outgoing path
84fa7933 143 * because the checksum is assumed to be correct.
9fb9cbb1 144 * FIXME: Source route IP option packets --RR */
c04d0552 145 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
96f6bf82 146 nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) {
c2a2c7e0 147 if (LOG_INVALID(net, IPPROTO_UDP))
30e0c6a6 148 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
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149 "nf_ct_udp: bad UDP checksum ");
150 return -NF_ACCEPT;
151 }
152
153 return NF_ACCEPT;
154}
155
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156#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
157
158#include <linux/netfilter/nfnetlink.h>
159#include <linux/netfilter/nfnetlink_cttimeout.h>
160
8264deb8
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161static int udp_timeout_nlattr_to_obj(struct nlattr *tb[],
162 struct net *net, void *data)
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163{
164 unsigned int *timeouts = data;
8264deb8 165 struct nf_udp_net *un = udp_pernet(net);
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166
167 /* set default timeouts for UDP. */
8264deb8
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168 timeouts[UDP_CT_UNREPLIED] = un->timeouts[UDP_CT_UNREPLIED];
169 timeouts[UDP_CT_REPLIED] = un->timeouts[UDP_CT_REPLIED];
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170
171 if (tb[CTA_TIMEOUT_UDP_UNREPLIED]) {
172 timeouts[UDP_CT_UNREPLIED] =
173 ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_UNREPLIED])) * HZ;
174 }
175 if (tb[CTA_TIMEOUT_UDP_REPLIED]) {
176 timeouts[UDP_CT_REPLIED] =
177 ntohl(nla_get_be32(tb[CTA_TIMEOUT_UDP_REPLIED])) * HZ;
178 }
179 return 0;
180}
181
182static int
183udp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
184{
185 const unsigned int *timeouts = data;
186
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DM
187 if (nla_put_be32(skb, CTA_TIMEOUT_UDP_UNREPLIED,
188 htonl(timeouts[UDP_CT_UNREPLIED] / HZ)) ||
189 nla_put_be32(skb, CTA_TIMEOUT_UDP_REPLIED,
190 htonl(timeouts[UDP_CT_REPLIED] / HZ)))
191 goto nla_put_failure;
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192 return 0;
193
194nla_put_failure:
195 return -ENOSPC;
196}
197
198static const struct nla_policy
199udp_timeout_nla_policy[CTA_TIMEOUT_UDP_MAX+1] = {
200 [CTA_TIMEOUT_UDP_UNREPLIED] = { .type = NLA_U32 },
201 [CTA_TIMEOUT_UDP_REPLIED] = { .type = NLA_U32 },
202};
203#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
204
933a41e7 205#ifdef CONFIG_SYSCTL
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206static struct ctl_table udp_sysctl_table[] = {
207 {
933a41e7 208 .procname = "nf_conntrack_udp_timeout",
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209 .maxlen = sizeof(unsigned int),
210 .mode = 0644,
6d9f239a 211 .proc_handler = proc_dointvec_jiffies,
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212 },
213 {
933a41e7 214 .procname = "nf_conntrack_udp_timeout_stream",
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215 .maxlen = sizeof(unsigned int),
216 .mode = 0644,
6d9f239a 217 .proc_handler = proc_dointvec_jiffies,
933a41e7 218 },
f8572d8f 219 { }
933a41e7 220};
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221#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
222static struct ctl_table udp_compat_sysctl_table[] = {
223 {
a999e683 224 .procname = "ip_conntrack_udp_timeout",
a999e683
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225 .maxlen = sizeof(unsigned int),
226 .mode = 0644,
6d9f239a 227 .proc_handler = proc_dointvec_jiffies,
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228 },
229 {
a999e683 230 .procname = "ip_conntrack_udp_timeout_stream",
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231 .maxlen = sizeof(unsigned int),
232 .mode = 0644,
6d9f239a 233 .proc_handler = proc_dointvec_jiffies,
a999e683 234 },
f8572d8f 235 { }
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236};
237#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
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238#endif /* CONFIG_SYSCTL */
239
dee7364e
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240static int udp_kmemdup_sysctl_table(struct nf_proto_net *pn,
241 struct nf_udp_net *un)
0ce490ad
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242{
243#ifdef CONFIG_SYSCTL
0ce490ad
G
244 if (pn->ctl_table)
245 return 0;
246 pn->ctl_table = kmemdup(udp_sysctl_table,
247 sizeof(udp_sysctl_table),
248 GFP_KERNEL);
249 if (!pn->ctl_table)
250 return -ENOMEM;
251 pn->ctl_table[0].data = &un->timeouts[UDP_CT_UNREPLIED];
252 pn->ctl_table[1].data = &un->timeouts[UDP_CT_REPLIED];
253#endif
254 return 0;
255}
256
dee7364e
G
257static int udp_kmemdup_compat_sysctl_table(struct nf_proto_net *pn,
258 struct nf_udp_net *un)
0ce490ad
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259{
260#ifdef CONFIG_SYSCTL
261#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
0ce490ad
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262 pn->ctl_compat_table = kmemdup(udp_compat_sysctl_table,
263 sizeof(udp_compat_sysctl_table),
264 GFP_KERNEL);
265 if (!pn->ctl_compat_table)
266 return -ENOMEM;
267
268 pn->ctl_compat_table[0].data = &un->timeouts[UDP_CT_UNREPLIED];
269 pn->ctl_compat_table[1].data = &un->timeouts[UDP_CT_REPLIED];
270#endif
271#endif
272 return 0;
273}
274
dee7364e 275static int udp_init_net(struct net *net, u_int16_t proto)
0ce490ad
G
276{
277 int ret;
278 struct nf_udp_net *un = udp_pernet(net);
dee7364e 279 struct nf_proto_net *pn = &un->pn;
0ce490ad 280
dee7364e
G
281 if (!pn->users) {
282 int i;
0ce490ad 283
dee7364e
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284 for (i = 0; i < UDP_CT_MAX; i++)
285 un->timeouts[i] = udp_timeouts[i];
0ce490ad 286 }
0ce490ad 287
dee7364e
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288 if (proto == AF_INET) {
289 ret = udp_kmemdup_compat_sysctl_table(pn, un);
290 if (ret < 0)
291 return ret;
0ce490ad 292
dee7364e
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293 ret = udp_kmemdup_sysctl_table(pn, un);
294 if (ret < 0)
295 nf_ct_kfree_compat_sysctl_table(pn);
296 } else
297 ret = udp_kmemdup_sysctl_table(pn, un);
298
299 return ret;
0ce490ad
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300}
301
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302static struct nf_proto_net *udp_get_net_proto(struct net *net)
303{
304 return &net->ct.nf_ct_proto.udp.pn;
305}
306
61075af5 307struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 __read_mostly =
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308{
309 .l3proto = PF_INET,
605dcad6 310 .l4proto = IPPROTO_UDP,
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311 .name = "udp",
312 .pkt_to_tuple = udp_pkt_to_tuple,
313 .invert_tuple = udp_invert_tuple,
314 .print_tuple = udp_print_tuple,
9fb9cbb1 315 .packet = udp_packet,
2c8503f5 316 .get_timeouts = udp_get_timeouts,
9fb9cbb1 317 .new = udp_new,
96f6bf82 318 .error = udp_error,
c0cd1156 319#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
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320 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
321 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
a400c30e 322 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
f73e924c 323 .nla_policy = nf_ct_port_nla_policy,
c1d10adb 324#endif
50978462
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325#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
326 .ctnl_timeout = {
327 .nlattr_to_obj = udp_timeout_nlattr_to_obj,
328 .obj_to_nlattr = udp_timeout_obj_to_nlattr,
329 .nlattr_max = CTA_TIMEOUT_UDP_MAX,
330 .obj_size = sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
331 .nla_policy = udp_timeout_nla_policy,
332 },
333#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
dee7364e 334 .init_net = udp_init_net,
08911475 335 .get_net_proto = udp_get_net_proto,
9fb9cbb1 336};
13b18339 337EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);
9fb9cbb1 338
61075af5 339struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 __read_mostly =
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340{
341 .l3proto = PF_INET6,
605dcad6 342 .l4proto = IPPROTO_UDP,
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343 .name = "udp",
344 .pkt_to_tuple = udp_pkt_to_tuple,
345 .invert_tuple = udp_invert_tuple,
346 .print_tuple = udp_print_tuple,
9fb9cbb1 347 .packet = udp_packet,
2c8503f5 348 .get_timeouts = udp_get_timeouts,
9fb9cbb1 349 .new = udp_new,
96f6bf82 350 .error = udp_error,
c0cd1156 351#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
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352 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
353 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
a400c30e 354 .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
f73e924c 355 .nla_policy = nf_ct_port_nla_policy,
c1d10adb 356#endif
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357#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
358 .ctnl_timeout = {
359 .nlattr_to_obj = udp_timeout_nlattr_to_obj,
360 .obj_to_nlattr = udp_timeout_obj_to_nlattr,
361 .nlattr_max = CTA_TIMEOUT_UDP_MAX,
362 .obj_size = sizeof(unsigned int) * CTA_TIMEOUT_UDP_MAX,
363 .nla_policy = udp_timeout_nla_policy,
364 },
365#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
dee7364e 366 .init_net = udp_init_net,
08911475 367 .get_net_proto = udp_get_net_proto,
9fb9cbb1 368};
13b18339 369EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6);