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[NETFILTER]: Convert DEBUGP to pr_debug
[deliverable/linux.git] / net / ipv4 / netfilter / nf_conntrack_l3proto_ipv4.c
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.
7 */
8
9 #include <linux/types.h>
10 #include <linux/ip.h>
11 #include <linux/netfilter.h>
12 #include <linux/module.h>
13 #include <linux/skbuff.h>
14 #include <linux/icmp.h>
15 #include <linux/sysctl.h>
16 #include <net/route.h>
17 #include <net/ip.h>
18
19 #include <linux/netfilter_ipv4.h>
20 #include <net/netfilter/nf_conntrack.h>
21 #include <net/netfilter/nf_conntrack_helper.h>
22 #include <net/netfilter/nf_conntrack_l4proto.h>
23 #include <net/netfilter/nf_conntrack_l3proto.h>
24 #include <net/netfilter/nf_conntrack_core.h>
25 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
26
27 static int ipv4_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
28 struct nf_conntrack_tuple *tuple)
29 {
30 __be32 _addrs[2], *ap;
31 ap = skb_header_pointer(skb, nhoff + offsetof(struct iphdr, saddr),
32 sizeof(u_int32_t) * 2, _addrs);
33 if (ap == NULL)
34 return 0;
35
36 tuple->src.u3.ip = ap[0];
37 tuple->dst.u3.ip = ap[1];
38
39 return 1;
40 }
41
42 static int ipv4_invert_tuple(struct nf_conntrack_tuple *tuple,
43 const struct nf_conntrack_tuple *orig)
44 {
45 tuple->src.u3.ip = orig->dst.u3.ip;
46 tuple->dst.u3.ip = orig->src.u3.ip;
47
48 return 1;
49 }
50
51 static int ipv4_print_tuple(struct seq_file *s,
52 const struct nf_conntrack_tuple *tuple)
53 {
54 return seq_printf(s, "src=%u.%u.%u.%u dst=%u.%u.%u.%u ",
55 NIPQUAD(tuple->src.u3.ip),
56 NIPQUAD(tuple->dst.u3.ip));
57 }
58
59 static int ipv4_print_conntrack(struct seq_file *s,
60 const struct nf_conn *conntrack)
61 {
62 return 0;
63 }
64
65 /* Returns new sk_buff, or NULL */
66 static struct sk_buff *
67 nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
68 {
69 skb_orphan(skb);
70
71 local_bh_disable();
72 skb = ip_defrag(skb, user);
73 local_bh_enable();
74
75 if (skb)
76 ip_send_check(ip_hdr(skb));
77
78 return skb;
79 }
80
81 static int
82 ipv4_prepare(struct sk_buff **pskb, unsigned int hooknum, unsigned int *dataoff,
83 u_int8_t *protonum)
84 {
85 /* Never happen */
86 if (ip_hdr(*pskb)->frag_off & htons(IP_OFFSET)) {
87 if (net_ratelimit()) {
88 printk(KERN_ERR "ipv4_prepare: Frag of proto %u (hook=%u)\n",
89 ip_hdr(*pskb)->protocol, hooknum);
90 }
91 return -NF_DROP;
92 }
93
94 *dataoff = skb_network_offset(*pskb) + ip_hdrlen(*pskb);
95 *protonum = ip_hdr(*pskb)->protocol;
96
97 return NF_ACCEPT;
98 }
99
100 static unsigned int ipv4_confirm(unsigned int hooknum,
101 struct sk_buff **pskb,
102 const struct net_device *in,
103 const struct net_device *out,
104 int (*okfn)(struct sk_buff *))
105 {
106 /* We've seen it coming out the other side: confirm it */
107 return nf_conntrack_confirm(pskb);
108 }
109
110 static unsigned int ipv4_conntrack_help(unsigned int hooknum,
111 struct sk_buff **pskb,
112 const struct net_device *in,
113 const struct net_device *out,
114 int (*okfn)(struct sk_buff *))
115 {
116 struct nf_conn *ct;
117 enum ip_conntrack_info ctinfo;
118 struct nf_conn_help *help;
119 struct nf_conntrack_helper *helper;
120
121 /* This is where we call the helper: as the packet goes out. */
122 ct = nf_ct_get(*pskb, &ctinfo);
123 if (!ct || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY)
124 return NF_ACCEPT;
125
126 help = nfct_help(ct);
127 if (!help)
128 return NF_ACCEPT;
129 /* rcu_read_lock()ed by nf_hook_slow */
130 helper = rcu_dereference(help->helper);
131 if (!helper)
132 return NF_ACCEPT;
133 return helper->help(pskb, skb_network_offset(*pskb) + ip_hdrlen(*pskb),
134 ct, ctinfo);
135 }
136
137 static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,
138 struct sk_buff **pskb,
139 const struct net_device *in,
140 const struct net_device *out,
141 int (*okfn)(struct sk_buff *))
142 {
143 /* Previously seen (loopback)? Ignore. Do this before
144 fragment check. */
145 if ((*pskb)->nfct)
146 return NF_ACCEPT;
147
148 /* Gather fragments. */
149 if (ip_hdr(*pskb)->frag_off & htons(IP_MF | IP_OFFSET)) {
150 *pskb = nf_ct_ipv4_gather_frags(*pskb,
151 hooknum == NF_IP_PRE_ROUTING ?
152 IP_DEFRAG_CONNTRACK_IN :
153 IP_DEFRAG_CONNTRACK_OUT);
154 if (!*pskb)
155 return NF_STOLEN;
156 }
157 return NF_ACCEPT;
158 }
159
160 static unsigned int ipv4_conntrack_in(unsigned int hooknum,
161 struct sk_buff **pskb,
162 const struct net_device *in,
163 const struct net_device *out,
164 int (*okfn)(struct sk_buff *))
165 {
166 return nf_conntrack_in(PF_INET, hooknum, pskb);
167 }
168
169 static unsigned int ipv4_conntrack_local(unsigned int hooknum,
170 struct sk_buff **pskb,
171 const struct net_device *in,
172 const struct net_device *out,
173 int (*okfn)(struct sk_buff *))
174 {
175 /* root is playing with raw sockets. */
176 if ((*pskb)->len < sizeof(struct iphdr)
177 || ip_hdrlen(*pskb) < sizeof(struct iphdr)) {
178 if (net_ratelimit())
179 printk("ipt_hook: happy cracking.\n");
180 return NF_ACCEPT;
181 }
182 return nf_conntrack_in(PF_INET, hooknum, pskb);
183 }
184
185 /* Connection tracking may drop packets, but never alters them, so
186 make it the first hook. */
187 static struct nf_hook_ops ipv4_conntrack_ops[] = {
188 {
189 .hook = ipv4_conntrack_defrag,
190 .owner = THIS_MODULE,
191 .pf = PF_INET,
192 .hooknum = NF_IP_PRE_ROUTING,
193 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
194 },
195 {
196 .hook = ipv4_conntrack_in,
197 .owner = THIS_MODULE,
198 .pf = PF_INET,
199 .hooknum = NF_IP_PRE_ROUTING,
200 .priority = NF_IP_PRI_CONNTRACK,
201 },
202 {
203 .hook = ipv4_conntrack_defrag,
204 .owner = THIS_MODULE,
205 .pf = PF_INET,
206 .hooknum = NF_IP_LOCAL_OUT,
207 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
208 },
209 {
210 .hook = ipv4_conntrack_local,
211 .owner = THIS_MODULE,
212 .pf = PF_INET,
213 .hooknum = NF_IP_LOCAL_OUT,
214 .priority = NF_IP_PRI_CONNTRACK,
215 },
216 {
217 .hook = ipv4_conntrack_help,
218 .owner = THIS_MODULE,
219 .pf = PF_INET,
220 .hooknum = NF_IP_POST_ROUTING,
221 .priority = NF_IP_PRI_CONNTRACK_HELPER,
222 },
223 {
224 .hook = ipv4_conntrack_help,
225 .owner = THIS_MODULE,
226 .pf = PF_INET,
227 .hooknum = NF_IP_LOCAL_IN,
228 .priority = NF_IP_PRI_CONNTRACK_HELPER,
229 },
230 {
231 .hook = ipv4_confirm,
232 .owner = THIS_MODULE,
233 .pf = PF_INET,
234 .hooknum = NF_IP_POST_ROUTING,
235 .priority = NF_IP_PRI_CONNTRACK_CONFIRM,
236 },
237 {
238 .hook = ipv4_confirm,
239 .owner = THIS_MODULE,
240 .pf = PF_INET,
241 .hooknum = NF_IP_LOCAL_IN,
242 .priority = NF_IP_PRI_CONNTRACK_CONFIRM,
243 },
244 };
245
246 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
247 static int log_invalid_proto_min = 0;
248 static int log_invalid_proto_max = 255;
249
250 static ctl_table ip_ct_sysctl_table[] = {
251 {
252 .ctl_name = NET_IPV4_NF_CONNTRACK_MAX,
253 .procname = "ip_conntrack_max",
254 .data = &nf_conntrack_max,
255 .maxlen = sizeof(int),
256 .mode = 0644,
257 .proc_handler = &proc_dointvec,
258 },
259 {
260 .ctl_name = NET_IPV4_NF_CONNTRACK_COUNT,
261 .procname = "ip_conntrack_count",
262 .data = &nf_conntrack_count,
263 .maxlen = sizeof(int),
264 .mode = 0444,
265 .proc_handler = &proc_dointvec,
266 },
267 {
268 .ctl_name = NET_IPV4_NF_CONNTRACK_BUCKETS,
269 .procname = "ip_conntrack_buckets",
270 .data = &nf_conntrack_htable_size,
271 .maxlen = sizeof(unsigned int),
272 .mode = 0444,
273 .proc_handler = &proc_dointvec,
274 },
275 {
276 .ctl_name = NET_IPV4_NF_CONNTRACK_CHECKSUM,
277 .procname = "ip_conntrack_checksum",
278 .data = &nf_conntrack_checksum,
279 .maxlen = sizeof(int),
280 .mode = 0644,
281 .proc_handler = &proc_dointvec,
282 },
283 {
284 .ctl_name = NET_IPV4_NF_CONNTRACK_LOG_INVALID,
285 .procname = "ip_conntrack_log_invalid",
286 .data = &nf_ct_log_invalid,
287 .maxlen = sizeof(unsigned int),
288 .mode = 0644,
289 .proc_handler = &proc_dointvec_minmax,
290 .strategy = &sysctl_intvec,
291 .extra1 = &log_invalid_proto_min,
292 .extra2 = &log_invalid_proto_max,
293 },
294 {
295 .ctl_name = 0
296 }
297 };
298 #endif /* CONFIG_SYSCTL && CONFIG_NF_CONNTRACK_PROC_COMPAT */
299
300 /* Fast function for those who don't want to parse /proc (and I don't
301 blame them). */
302 /* Reversing the socket's dst/src point of view gives us the reply
303 mapping. */
304 static int
305 getorigdst(struct sock *sk, int optval, void __user *user, int *len)
306 {
307 struct inet_sock *inet = inet_sk(sk);
308 struct nf_conntrack_tuple_hash *h;
309 struct nf_conntrack_tuple tuple;
310
311 NF_CT_TUPLE_U_BLANK(&tuple);
312 tuple.src.u3.ip = inet->rcv_saddr;
313 tuple.src.u.tcp.port = inet->sport;
314 tuple.dst.u3.ip = inet->daddr;
315 tuple.dst.u.tcp.port = inet->dport;
316 tuple.src.l3num = PF_INET;
317 tuple.dst.protonum = IPPROTO_TCP;
318
319 /* We only do TCP at the moment: is there a better way? */
320 if (strcmp(sk->sk_prot->name, "TCP")) {
321 pr_debug("SO_ORIGINAL_DST: Not a TCP socket\n");
322 return -ENOPROTOOPT;
323 }
324
325 if ((unsigned int) *len < sizeof(struct sockaddr_in)) {
326 pr_debug("SO_ORIGINAL_DST: len %d not %Zu\n",
327 *len, sizeof(struct sockaddr_in));
328 return -EINVAL;
329 }
330
331 h = nf_conntrack_find_get(&tuple);
332 if (h) {
333 struct sockaddr_in sin;
334 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
335
336 sin.sin_family = AF_INET;
337 sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL]
338 .tuple.dst.u.tcp.port;
339 sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL]
340 .tuple.dst.u3.ip;
341 memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
342
343 pr_debug("SO_ORIGINAL_DST: %u.%u.%u.%u %u\n",
344 NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
345 nf_ct_put(ct);
346 if (copy_to_user(user, &sin, sizeof(sin)) != 0)
347 return -EFAULT;
348 else
349 return 0;
350 }
351 pr_debug("SO_ORIGINAL_DST: Can't find %u.%u.%u.%u/%u-%u.%u.%u.%u/%u.\n",
352 NIPQUAD(tuple.src.u3.ip), ntohs(tuple.src.u.tcp.port),
353 NIPQUAD(tuple.dst.u3.ip), ntohs(tuple.dst.u.tcp.port));
354 return -ENOENT;
355 }
356
357 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
358
359 #include <linux/netfilter/nfnetlink.h>
360 #include <linux/netfilter/nfnetlink_conntrack.h>
361
362 static int ipv4_tuple_to_nfattr(struct sk_buff *skb,
363 const struct nf_conntrack_tuple *tuple)
364 {
365 NFA_PUT(skb, CTA_IP_V4_SRC, sizeof(u_int32_t),
366 &tuple->src.u3.ip);
367 NFA_PUT(skb, CTA_IP_V4_DST, sizeof(u_int32_t),
368 &tuple->dst.u3.ip);
369 return 0;
370
371 nfattr_failure:
372 return -1;
373 }
374
375 static const size_t cta_min_ip[CTA_IP_MAX] = {
376 [CTA_IP_V4_SRC-1] = sizeof(u_int32_t),
377 [CTA_IP_V4_DST-1] = sizeof(u_int32_t),
378 };
379
380 static int ipv4_nfattr_to_tuple(struct nfattr *tb[],
381 struct nf_conntrack_tuple *t)
382 {
383 if (!tb[CTA_IP_V4_SRC-1] || !tb[CTA_IP_V4_DST-1])
384 return -EINVAL;
385
386 if (nfattr_bad_size(tb, CTA_IP_MAX, cta_min_ip))
387 return -EINVAL;
388
389 t->src.u3.ip = *(__be32 *)NFA_DATA(tb[CTA_IP_V4_SRC-1]);
390 t->dst.u3.ip = *(__be32 *)NFA_DATA(tb[CTA_IP_V4_DST-1]);
391
392 return 0;
393 }
394 #endif
395
396 static struct nf_sockopt_ops so_getorigdst = {
397 .pf = PF_INET,
398 .get_optmin = SO_ORIGINAL_DST,
399 .get_optmax = SO_ORIGINAL_DST+1,
400 .get = &getorigdst,
401 };
402
403 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 = {
404 .l3proto = PF_INET,
405 .name = "ipv4",
406 .pkt_to_tuple = ipv4_pkt_to_tuple,
407 .invert_tuple = ipv4_invert_tuple,
408 .print_tuple = ipv4_print_tuple,
409 .print_conntrack = ipv4_print_conntrack,
410 .prepare = ipv4_prepare,
411 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
412 .tuple_to_nfattr = ipv4_tuple_to_nfattr,
413 .nfattr_to_tuple = ipv4_nfattr_to_tuple,
414 #endif
415 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
416 .ctl_table_path = nf_net_ipv4_netfilter_sysctl_path,
417 .ctl_table = ip_ct_sysctl_table,
418 #endif
419 .me = THIS_MODULE,
420 };
421
422 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
423 MODULE_ALIAS("ip_conntrack");
424 MODULE_LICENSE("GPL");
425
426 static int __init nf_conntrack_l3proto_ipv4_init(void)
427 {
428 int ret = 0;
429
430 need_conntrack();
431
432 ret = nf_register_sockopt(&so_getorigdst);
433 if (ret < 0) {
434 printk(KERN_ERR "Unable to register netfilter socket option\n");
435 return ret;
436 }
437
438 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp4);
439 if (ret < 0) {
440 printk("nf_conntrack_ipv4: can't register tcp.\n");
441 goto cleanup_sockopt;
442 }
443
444 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp4);
445 if (ret < 0) {
446 printk("nf_conntrack_ipv4: can't register udp.\n");
447 goto cleanup_tcp;
448 }
449
450 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmp);
451 if (ret < 0) {
452 printk("nf_conntrack_ipv4: can't register icmp.\n");
453 goto cleanup_udp;
454 }
455
456 ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4);
457 if (ret < 0) {
458 printk("nf_conntrack_ipv4: can't register ipv4\n");
459 goto cleanup_icmp;
460 }
461
462 ret = nf_register_hooks(ipv4_conntrack_ops,
463 ARRAY_SIZE(ipv4_conntrack_ops));
464 if (ret < 0) {
465 printk("nf_conntrack_ipv4: can't register hooks.\n");
466 goto cleanup_ipv4;
467 }
468 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
469 ret = nf_conntrack_ipv4_compat_init();
470 if (ret < 0)
471 goto cleanup_hooks;
472 #endif
473 return ret;
474 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
475 cleanup_hooks:
476 nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
477 #endif
478 cleanup_ipv4:
479 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
480 cleanup_icmp:
481 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
482 cleanup_udp:
483 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
484 cleanup_tcp:
485 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
486 cleanup_sockopt:
487 nf_unregister_sockopt(&so_getorigdst);
488 return ret;
489 }
490
491 static void __exit nf_conntrack_l3proto_ipv4_fini(void)
492 {
493 synchronize_net();
494 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
495 nf_conntrack_ipv4_compat_fini();
496 #endif
497 nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
498 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
499 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
500 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
501 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
502 nf_unregister_sockopt(&so_getorigdst);
503 }
504
505 module_init(nf_conntrack_l3proto_ipv4_init);
506 module_exit(nf_conntrack_l3proto_ipv4_fini);
Linux kernel - Deliverables
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