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GUI: Fix Tomato RAF theme for all builds. Compilation typo.
[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / net / ipv4 / netfilter / nf_conntrack_l3proto_ipv4.c
blob5a03c02af999a45ac7d3f9e403ea1c2d38bc0c5a
1
2 /* (C) 1999-2001 Paul `Rusty' Russell
3 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
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/ip.h>
12 #include <linux/netfilter.h>
13 #include <linux/module.h>
14 #include <linux/skbuff.h>
15 #include <linux/icmp.h>
16 #include <linux/sysctl.h>
17 #include <net/route.h>
18 #include <net/ip.h>
19
20 #include <linux/netfilter_ipv4.h>
21 #include <net/netfilter/nf_conntrack.h>
22 #include <net/netfilter/nf_conntrack_helper.h>
23 #include <net/netfilter/nf_conntrack_l4proto.h>
24 #include <net/netfilter/nf_conntrack_l3proto.h>
25 #include <net/netfilter/nf_conntrack_zones.h>
26 #include <net/netfilter/nf_conntrack_core.h>
27 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
28 #include <net/netfilter/nf_nat_helper.h>
29 #include <net/netfilter/ipv4/nf_defrag_ipv4.h>
30 #include <net/netfilter/nf_log.h>
31
32 int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
33 struct nf_conn *ct,
34 enum ip_conntrack_info ctinfo);
35 EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook);
36
37 static bool ipv4_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
38 struct nf_conntrack_tuple *tuple)
39 {
40 const __be32 *ap;
41 __be32 _addrs[2];
42 ap = skb_header_pointer(skb, nhoff + offsetof(struct iphdr, saddr),
43 sizeof(u_int32_t) * 2, _addrs);
44 if (ap == NULL)
45 return false;
46
47 tuple->src.u3.ip = ap[0];
48 tuple->dst.u3.ip = ap[1];
49
50 return true;
51 }
52
53 static bool ipv4_invert_tuple(struct nf_conntrack_tuple *tuple,
54 const struct nf_conntrack_tuple *orig)
55 {
56 tuple->src.u3.ip = orig->dst.u3.ip;
57 tuple->dst.u3.ip = orig->src.u3.ip;
58
59 return true;
60 }
61
62 static int ipv4_print_tuple(struct seq_file *s,
63 const struct nf_conntrack_tuple *tuple)
64 {
65 return seq_printf(s, "src=%pI4 dst=%pI4 ",
66 &tuple->src.u3.ip, &tuple->dst.u3.ip);
67 }
68
69 static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
70 unsigned int *dataoff, u_int8_t *protonum)
71 {
72 const struct iphdr *iph;
73 struct iphdr _iph;
74
75 iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
76 if (iph == NULL)
77 return -NF_DROP;
78
79 /* Conntrack defragments packets, we might still see fragments
80 * inside ICMP packets though. */
81 if (iph->frag_off & htons(IP_OFFSET))
82 return -NF_DROP;
83
84 *dataoff = nhoff + (iph->ihl << 2);
85 *protonum = iph->protocol;
86
87 return NF_ACCEPT;
88 }
89
90 static unsigned int ipv4_confirm(unsigned int hooknum,
91 struct sk_buff *skb,
92 const struct net_device *in,
93 const struct net_device *out,
94 int (*okfn)(struct sk_buff *))
95 {
96 struct nf_conn *ct;
97 enum ip_conntrack_info ctinfo;
98 const struct nf_conn_help *help;
99 const struct nf_conntrack_helper *helper;
100 unsigned int ret;
101
102 /* This is where we call the helper: as the packet goes out. */
103 ct = nf_ct_get(skb, &ctinfo);
104 if (!ct || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY)
105 goto out;
106
107 help = nfct_help(ct);
108 if (!help)
109 goto out;
110
111 /* rcu_read_lock()ed by nf_hook_slow */
112 helper = rcu_dereference(help->helper);
113 if (!helper)
114 goto out;
115
116 ret = helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
117 ct, ctinfo);
118 if (ret != NF_ACCEPT) {
119 nf_log_packet(NFPROTO_IPV4, hooknum, skb, in, out, NULL,
120 "nf_ct_%s: dropping packet", helper->name);
121 return ret;
122 }
123
124 if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status)) {
125 typeof(nf_nat_seq_adjust_hook) seq_adjust;
126
127 seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook);
128 if (!seq_adjust || !seq_adjust(skb, ct, ctinfo)) {
129 NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
130 return NF_DROP;
131 }
132 }
133 out:
134 /* We've seen it coming out the other side: confirm it */
135 return nf_conntrack_confirm(skb);
136 }
137
138 static unsigned int ipv4_conntrack_in(unsigned int hooknum,
139 struct sk_buff *skb,
140 const struct net_device *in,
141 const struct net_device *out,
142 int (*okfn)(struct sk_buff *))
143 {
144 return nf_conntrack_in(dev_net(in), PF_INET, hooknum, skb);
145 }
146
147 static unsigned int ipv4_conntrack_local(unsigned int hooknum,
148 struct sk_buff *skb,
149 const struct net_device *in,
150 const struct net_device *out,
151 int (*okfn)(struct sk_buff *))
152 {
153 /* root is playing with raw sockets. */
154 if (skb->len < sizeof(struct iphdr) ||
155 ip_hdrlen(skb) < sizeof(struct iphdr))
156 return NF_ACCEPT;
157 return nf_conntrack_in(dev_net(out), PF_INET, hooknum, skb);
158 }
159
160 /* Connection tracking may drop packets, but never alters them, so
161 make it the first hook. */
162 static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
163 {
164 .hook = ipv4_conntrack_in,
165 .owner = THIS_MODULE,
166 .pf = NFPROTO_IPV4,
167 .hooknum = NF_INET_PRE_ROUTING,
168 .priority = NF_IP_PRI_CONNTRACK,
169 },
170 {
171 .hook = ipv4_conntrack_local,
172 .owner = THIS_MODULE,
173 .pf = NFPROTO_IPV4,
174 .hooknum = NF_INET_LOCAL_OUT,
175 .priority = NF_IP_PRI_CONNTRACK,
176 },
177 {
178 .hook = ipv4_confirm,
179 .owner = THIS_MODULE,
180 .pf = NFPROTO_IPV4,
181 .hooknum = NF_INET_POST_ROUTING,
182 .priority = NF_IP_PRI_CONNTRACK_CONFIRM,
183 },
184 {
185 .hook = ipv4_confirm,
186 .owner = THIS_MODULE,
187 .pf = NFPROTO_IPV4,
188 .hooknum = NF_INET_LOCAL_IN,
189 .priority = NF_IP_PRI_CONNTRACK_CONFIRM,
190 },
191 };
192
193 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
194 static int log_invalid_proto_min = 0;
195 static int log_invalid_proto_max = 255;
196
197 static ctl_table ip_ct_sysctl_table[] = {
198 {
199 .procname = "ip_conntrack_max",
200 .data = &nf_conntrack_max,
201 .maxlen = sizeof(int),
202 .mode = 0644,
203 .proc_handler = proc_dointvec,
204 },
205 {
206 .procname = "ip_conntrack_count",
207 .data = &init_net.ct.count,
208 .maxlen = sizeof(int),
209 .mode = 0444,
210 .proc_handler = proc_dointvec,
211 },
212 {
213 .procname = "ip_conntrack_buckets",
214 .data = &init_net.ct.htable_size,
215 .maxlen = sizeof(unsigned int),
216 .mode = 0444,
217 .proc_handler = proc_dointvec,
218 },
219 {
220 .procname = "ip_conntrack_checksum",
221 .data = &init_net.ct.sysctl_checksum,
222 .maxlen = sizeof(int),
223 .mode = 0644,
224 .proc_handler = proc_dointvec,
225 },
226 {
227 .procname = "ip_conntrack_log_invalid",
228 .data = &init_net.ct.sysctl_log_invalid,
229 .maxlen = sizeof(unsigned int),
230 .mode = 0644,
231 .proc_handler = proc_dointvec_minmax,
232 .extra1 = &log_invalid_proto_min,
233 .extra2 = &log_invalid_proto_max,
234 },
235 { }
236 };
237 #endif /* CONFIG_SYSCTL && CONFIG_NF_CONNTRACK_PROC_COMPAT */
238
239 /* Fast function for those who don't want to parse /proc (and I don't
240 blame them). */
241 /* Reversing the socket's dst/src point of view gives us the reply
242 mapping. */
243 static int
244 getorigdst(struct sock *sk, int optval, void __user *user, int *len)
245 {
246 const struct inet_sock *inet = inet_sk(sk);
247 const struct nf_conntrack_tuple_hash *h;
248 struct nf_conntrack_tuple tuple;
249
250 memset(&tuple, 0, sizeof(tuple));
251 tuple.src.u3.ip = inet->inet_rcv_saddr;
252 tuple.src.u.tcp.port = inet->inet_sport;
253 tuple.dst.u3.ip = inet->inet_daddr;
254 tuple.dst.u.tcp.port = inet->inet_dport;
255 tuple.src.l3num = PF_INET;
256 tuple.dst.protonum = sk->sk_protocol;
257
258 /* We only do TCP and SCTP at the moment: is there a better way? */
259 if (sk->sk_protocol != IPPROTO_TCP && sk->sk_protocol != IPPROTO_SCTP) {
260 pr_debug("SO_ORIGINAL_DST: Not a TCP/SCTP socket\n");
261 return -ENOPROTOOPT;
262 }
263
264 if ((unsigned int) *len < sizeof(struct sockaddr_in)) {
265 pr_debug("SO_ORIGINAL_DST: len %d not %Zu\n",
266 *len, sizeof(struct sockaddr_in));
267 return -EINVAL;
268 }
269
270 h = nf_conntrack_find_get(sock_net(sk), NF_CT_DEFAULT_ZONE, &tuple);
271 if (h) {
272 struct sockaddr_in sin;
273 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
274
275 sin.sin_family = AF_INET;
276 sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL]
277 .tuple.dst.u.tcp.port;
278 sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL]
279 .tuple.dst.u3.ip;
280 memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
281
282 pr_debug("SO_ORIGINAL_DST: %pI4 %u\n",
283 &sin.sin_addr.s_addr, ntohs(sin.sin_port));
284 nf_ct_put(ct);
285 if (copy_to_user(user, &sin, sizeof(sin)) != 0)
286 return -EFAULT;
287 else
288 return 0;
289 }
290 pr_debug("SO_ORIGINAL_DST: Can't find %pI4/%u-%pI4/%u.\n",
291 &tuple.src.u3.ip, ntohs(tuple.src.u.tcp.port),
292 &tuple.dst.u3.ip, ntohs(tuple.dst.u.tcp.port));
293 return -ENOENT;
294 }
295
296 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
297
298 #include <linux/netfilter/nfnetlink.h>
299 #include <linux/netfilter/nfnetlink_conntrack.h>
300
301 static int ipv4_tuple_to_nlattr(struct sk_buff *skb,
302 const struct nf_conntrack_tuple *tuple)
303 {
304 NLA_PUT_BE32(skb, CTA_IP_V4_SRC, tuple->src.u3.ip);
305 NLA_PUT_BE32(skb, CTA_IP_V4_DST, tuple->dst.u3.ip);
306 return 0;
307
308 nla_put_failure:
309 return -1;
310 }
311
312 static const struct nla_policy ipv4_nla_policy[CTA_IP_MAX+1] = {
313 [CTA_IP_V4_SRC] = { .type = NLA_U32 },
314 [CTA_IP_V4_DST] = { .type = NLA_U32 },
315 };
316
317 static int ipv4_nlattr_to_tuple(struct nlattr *tb[],
318 struct nf_conntrack_tuple *t)
319 {
320 if (!tb[CTA_IP_V4_SRC] || !tb[CTA_IP_V4_DST])
321 return -EINVAL;
322
323 t->src.u3.ip = nla_get_be32(tb[CTA_IP_V4_SRC]);
324 t->dst.u3.ip = nla_get_be32(tb[CTA_IP_V4_DST]);
325
326 return 0;
327 }
328
329 static int ipv4_nlattr_tuple_size(void)
330 {
331 return nla_policy_len(ipv4_nla_policy, CTA_IP_MAX + 1);
332 }
333 #endif
334
335 static struct nf_sockopt_ops so_getorigdst = {
336 .pf = PF_INET,
337 .get_optmin = SO_ORIGINAL_DST,
338 .get_optmax = SO_ORIGINAL_DST+1,
339 .get = &getorigdst,
340 .owner = THIS_MODULE,
341 };
342
343 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 __read_mostly = {
344 .l3proto = PF_INET,
345 .name = "ipv4",
346 .pkt_to_tuple = ipv4_pkt_to_tuple,
347 .invert_tuple = ipv4_invert_tuple,
348 .print_tuple = ipv4_print_tuple,
349 .get_l4proto = ipv4_get_l4proto,
350 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
351 .tuple_to_nlattr = ipv4_tuple_to_nlattr,
352 .nlattr_tuple_size = ipv4_nlattr_tuple_size,
353 .nlattr_to_tuple = ipv4_nlattr_to_tuple,
354 .nla_policy = ipv4_nla_policy,
355 #endif
356 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
357 .ctl_table_path = nf_net_ipv4_netfilter_sysctl_path,
358 .ctl_table = ip_ct_sysctl_table,
359 #endif
360 .me = THIS_MODULE,
361 };
362
363 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
364 &nf_conntrack_htable_size, 0600);
365
366 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
367 MODULE_ALIAS("ip_conntrack");
368 MODULE_LICENSE("GPL");
369
370 static int __init nf_conntrack_l3proto_ipv4_init(void)
371 {
372 int ret = 0;
373
374 need_conntrack();
375 nf_defrag_ipv4_enable();
376
377 ret = nf_register_sockopt(&so_getorigdst);
378 if (ret < 0) {
379 printk(KERN_ERR "Unable to register netfilter socket option\n");
380 return ret;
381 }
382
383 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp4);
384 if (ret < 0) {
385 pr_err("nf_conntrack_ipv4: can't register tcp.\n");
386 goto cleanup_sockopt;
387 }
388
389 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp4);
390 if (ret < 0) {
391 pr_err("nf_conntrack_ipv4: can't register udp.\n");
392 goto cleanup_tcp;
393 }
394
395 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmp);
396 if (ret < 0) {
397 pr_err("nf_conntrack_ipv4: can't register icmp.\n");
398 goto cleanup_udp;
399 }
400
401 ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4);
402 if (ret < 0) {
403 pr_err("nf_conntrack_ipv4: can't register ipv4\n");
404 goto cleanup_icmp;
405 }
406
407 ret = nf_register_hooks(ipv4_conntrack_ops,
408 ARRAY_SIZE(ipv4_conntrack_ops));
409 if (ret < 0) {
410 pr_err("nf_conntrack_ipv4: can't register hooks.\n");
411 goto cleanup_ipv4;
412 }
413 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
414 ret = nf_conntrack_ipv4_compat_init();
415 if (ret < 0)
416 goto cleanup_hooks;
417 #endif
418 return ret;
419 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
420 cleanup_hooks:
421 nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
422 #endif
423 cleanup_ipv4:
424 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
425 cleanup_icmp:
426 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
427 cleanup_udp:
428 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
429 cleanup_tcp:
430 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
431 cleanup_sockopt:
432 nf_unregister_sockopt(&so_getorigdst);
433 return ret;
434 }
435
436 static void __exit nf_conntrack_l3proto_ipv4_fini(void)
437 {
438 synchronize_net();
439 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
440 nf_conntrack_ipv4_compat_fini();
441 #endif
442 nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
443 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
444 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
445 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
446 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
447 nf_unregister_sockopt(&so_getorigdst);
448 }
449
450 module_init(nf_conntrack_l3proto_ipv4_init);
451 module_exit(nf_conntrack_l3proto_ipv4_fini);
452
453 void need_ipv4_conntrack(void)
454 {
455 return;
456 }
457 EXPORT_SYMBOL_GPL(need_ipv4_conntrack);
Tomato firmware and modifications.