?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
USB: usbfs: fix -ENOENT error code to be -ENODEV
[linux-2.6/libata-dev.git] / net / ipv4 / netfilter / nf_conntrack_l3proto_ipv4.c
blob7d2ead7228ac700265a35b295767f58bc4fd2952
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_core.h>
26 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
27 #include <net/netfilter/nf_nat_helper.h>
28 #include <net/netfilter/ipv4/nf_defrag_ipv4.h>
29
30 int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
31 struct nf_conn *ct,
32 enum ip_conntrack_info ctinfo);
33 EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook);
34
35 static bool ipv4_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
36 struct nf_conntrack_tuple *tuple)
37 {
38 const __be32 *ap;
39 __be32 _addrs[2];
40 ap = skb_header_pointer(skb, nhoff + offsetof(struct iphdr, saddr),
41 sizeof(u_int32_t) * 2, _addrs);
42 if (ap == NULL)
43 return false;
44
45 tuple->src.u3.ip = ap[0];
46 tuple->dst.u3.ip = ap[1];
47
48 return true;
49 }
50
51 static bool ipv4_invert_tuple(struct nf_conntrack_tuple *tuple,
52 const struct nf_conntrack_tuple *orig)
53 {
54 tuple->src.u3.ip = orig->dst.u3.ip;
55 tuple->dst.u3.ip = orig->src.u3.ip;
56
57 return true;
58 }
59
60 static int ipv4_print_tuple(struct seq_file *s,
61 const struct nf_conntrack_tuple *tuple)
62 {
63 return seq_printf(s, "src=%pI4 dst=%pI4 ",
64 &tuple->src.u3.ip, &tuple->dst.u3.ip);
65 }
66
67 static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
68 unsigned int *dataoff, u_int8_t *protonum)
69 {
70 const struct iphdr *iph;
71 struct iphdr _iph;
72
73 iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
74 if (iph == NULL)
75 return -NF_DROP;
76
77 /* Conntrack defragments packets, we might still see fragments
78 * inside ICMP packets though. */
79 if (iph->frag_off & htons(IP_OFFSET))
80 return -NF_DROP;
81
82 *dataoff = nhoff + (iph->ihl << 2);
83 *protonum = iph->protocol;
84
85 return NF_ACCEPT;
86 }
87
88 static unsigned int ipv4_confirm(unsigned int hooknum,
89 struct sk_buff *skb,
90 const struct net_device *in,
91 const struct net_device *out,
92 int (*okfn)(struct sk_buff *))
93 {
94 struct nf_conn *ct;
95 enum ip_conntrack_info ctinfo;
96 const struct nf_conn_help *help;
97 const struct nf_conntrack_helper *helper;
98 unsigned int ret;
99
100 /* This is where we call the helper: as the packet goes out. */
101 ct = nf_ct_get(skb, &ctinfo);
102 if (!ct || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY)
103 goto out;
104
105 help = nfct_help(ct);
106 if (!help)
107 goto out;
108
109 /* rcu_read_lock()ed by nf_hook_slow */
110 helper = rcu_dereference(help->helper);
111 if (!helper)
112 goto out;
113
114 ret = helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
115 ct, ctinfo);
116 if (ret != NF_ACCEPT)
117 return ret;
118
119 if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status)) {
120 typeof(nf_nat_seq_adjust_hook) seq_adjust;
121
122 seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook);
123 if (!seq_adjust || !seq_adjust(skb, ct, ctinfo)) {
124 NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
125 return NF_DROP;
126 }
127 }
128 out:
129 /* We've seen it coming out the other side: confirm it */
130 return nf_conntrack_confirm(skb);
131 }
132
133 static unsigned int ipv4_conntrack_in(unsigned int hooknum,
134 struct sk_buff *skb,
135 const struct net_device *in,
136 const struct net_device *out,
137 int (*okfn)(struct sk_buff *))
138 {
139 return nf_conntrack_in(dev_net(in), PF_INET, hooknum, skb);
140 }
141
142 static unsigned int ipv4_conntrack_local(unsigned int hooknum,
143 struct sk_buff *skb,
144 const struct net_device *in,
145 const struct net_device *out,
146 int (*okfn)(struct sk_buff *))
147 {
148 /* root is playing with raw sockets. */
149 if (skb->len < sizeof(struct iphdr) ||
150 ip_hdrlen(skb) < sizeof(struct iphdr))
151 return NF_ACCEPT;
152 return nf_conntrack_in(dev_net(out), PF_INET, hooknum, skb);
153 }
154
155 /* Connection tracking may drop packets, but never alters them, so
156 make it the first hook. */
157 static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
158 {
159 .hook = ipv4_conntrack_in,
160 .owner = THIS_MODULE,
161 .pf = PF_INET,
162 .hooknum = NF_INET_PRE_ROUTING,
163 .priority = NF_IP_PRI_CONNTRACK,
164 },
165 {
166 .hook = ipv4_conntrack_local,
167 .owner = THIS_MODULE,
168 .pf = PF_INET,
169 .hooknum = NF_INET_LOCAL_OUT,
170 .priority = NF_IP_PRI_CONNTRACK,
171 },
172 {
173 .hook = ipv4_confirm,
174 .owner = THIS_MODULE,
175 .pf = PF_INET,
176 .hooknum = NF_INET_POST_ROUTING,
177 .priority = NF_IP_PRI_CONNTRACK_CONFIRM,
178 },
179 {
180 .hook = ipv4_confirm,
181 .owner = THIS_MODULE,
182 .pf = PF_INET,
183 .hooknum = NF_INET_LOCAL_IN,
184 .priority = NF_IP_PRI_CONNTRACK_CONFIRM,
185 },
186 };
187
188 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
189 static int log_invalid_proto_min = 0;
190 static int log_invalid_proto_max = 255;
191
192 static ctl_table ip_ct_sysctl_table[] = {
193 {
194 .ctl_name = NET_IPV4_NF_CONNTRACK_MAX,
195 .procname = "ip_conntrack_max",
196 .data = &nf_conntrack_max,
197 .maxlen = sizeof(int),
198 .mode = 0644,
199 .proc_handler = proc_dointvec,
200 },
201 {
202 .ctl_name = NET_IPV4_NF_CONNTRACK_COUNT,
203 .procname = "ip_conntrack_count",
204 .data = &init_net.ct.count,
205 .maxlen = sizeof(int),
206 .mode = 0444,
207 .proc_handler = proc_dointvec,
208 },
209 {
210 .ctl_name = NET_IPV4_NF_CONNTRACK_BUCKETS,
211 .procname = "ip_conntrack_buckets",
212 .data = &nf_conntrack_htable_size,
213 .maxlen = sizeof(unsigned int),
214 .mode = 0444,
215 .proc_handler = proc_dointvec,
216 },
217 {
218 .ctl_name = NET_IPV4_NF_CONNTRACK_CHECKSUM,
219 .procname = "ip_conntrack_checksum",
220 .data = &init_net.ct.sysctl_checksum,
221 .maxlen = sizeof(int),
222 .mode = 0644,
223 .proc_handler = proc_dointvec,
224 },
225 {
226 .ctl_name = NET_IPV4_NF_CONNTRACK_LOG_INVALID,
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 .strategy = sysctl_intvec,
233 .extra1 = &log_invalid_proto_min,
234 .extra2 = &log_invalid_proto_max,
235 },
236 {
237 .ctl_name = 0
238 }
239 };
240 #endif /* CONFIG_SYSCTL && CONFIG_NF_CONNTRACK_PROC_COMPAT */
241
242 /* Fast function for those who don't want to parse /proc (and I don't
243 blame them). */
244 /* Reversing the socket's dst/src point of view gives us the reply
245 mapping. */
246 static int
247 getorigdst(struct sock *sk, int optval, void __user *user, int *len)
248 {
249 const struct inet_sock *inet = inet_sk(sk);
250 const struct nf_conntrack_tuple_hash *h;
251 struct nf_conntrack_tuple tuple;
252
253 memset(&tuple, 0, sizeof(tuple));
254 tuple.src.u3.ip = inet->rcv_saddr;
255 tuple.src.u.tcp.port = inet->sport;
256 tuple.dst.u3.ip = inet->daddr;
257 tuple.dst.u.tcp.port = inet->dport;
258 tuple.src.l3num = PF_INET;
259 tuple.dst.protonum = IPPROTO_TCP;
260
261 /* We only do TCP at the moment: is there a better way? */
262 if (strcmp(sk->sk_prot->name, "TCP")) {
263 pr_debug("SO_ORIGINAL_DST: Not a TCP socket\n");
264 return -ENOPROTOOPT;
265 }
266
267 if ((unsigned int) *len < sizeof(struct sockaddr_in)) {
268 pr_debug("SO_ORIGINAL_DST: len %d not %Zu\n",
269 *len, sizeof(struct sockaddr_in));
270 return -EINVAL;
271 }
272
273 h = nf_conntrack_find_get(sock_net(sk), &tuple);
274 if (h) {
275 struct sockaddr_in sin;
276 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
277
278 sin.sin_family = AF_INET;
279 sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL]
280 .tuple.dst.u.tcp.port;
281 sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL]
282 .tuple.dst.u3.ip;
283 memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
284
285 pr_debug("SO_ORIGINAL_DST: %pI4 %u\n",
286 &sin.sin_addr.s_addr, ntohs(sin.sin_port));
287 nf_ct_put(ct);
288 if (copy_to_user(user, &sin, sizeof(sin)) != 0)
289 return -EFAULT;
290 else
291 return 0;
292 }
293 pr_debug("SO_ORIGINAL_DST: Can't find %pI4/%u-%pI4/%u.\n",
294 &tuple.src.u3.ip, ntohs(tuple.src.u.tcp.port),
295 &tuple.dst.u3.ip, ntohs(tuple.dst.u.tcp.port));
296 return -ENOENT;
297 }
298
299 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
300
301 #include <linux/netfilter/nfnetlink.h>
302 #include <linux/netfilter/nfnetlink_conntrack.h>
303
304 static int ipv4_tuple_to_nlattr(struct sk_buff *skb,
305 const struct nf_conntrack_tuple *tuple)
306 {
307 NLA_PUT_BE32(skb, CTA_IP_V4_SRC, tuple->src.u3.ip);
308 NLA_PUT_BE32(skb, CTA_IP_V4_DST, tuple->dst.u3.ip);
309 return 0;
310
311 nla_put_failure:
312 return -1;
313 }
314
315 static const struct nla_policy ipv4_nla_policy[CTA_IP_MAX+1] = {
316 [CTA_IP_V4_SRC] = { .type = NLA_U32 },
317 [CTA_IP_V4_DST] = { .type = NLA_U32 },
318 };
319
320 static int ipv4_nlattr_to_tuple(struct nlattr *tb[],
321 struct nf_conntrack_tuple *t)
322 {
323 if (!tb[CTA_IP_V4_SRC] || !tb[CTA_IP_V4_DST])
324 return -EINVAL;
325
326 t->src.u3.ip = nla_get_be32(tb[CTA_IP_V4_SRC]);
327 t->dst.u3.ip = nla_get_be32(tb[CTA_IP_V4_DST]);
328
329 return 0;
330 }
331
332 static int ipv4_nlattr_tuple_size(void)
333 {
334 return nla_policy_len(ipv4_nla_policy, CTA_IP_MAX + 1);
335 }
336 #endif
337
338 static struct nf_sockopt_ops so_getorigdst = {
339 .pf = PF_INET,
340 .get_optmin = SO_ORIGINAL_DST,
341 .get_optmax = SO_ORIGINAL_DST+1,
342 .get = &getorigdst,
343 .owner = THIS_MODULE,
344 };
345
346 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 __read_mostly = {
347 .l3proto = PF_INET,
348 .name = "ipv4",
349 .pkt_to_tuple = ipv4_pkt_to_tuple,
350 .invert_tuple = ipv4_invert_tuple,
351 .print_tuple = ipv4_print_tuple,
352 .get_l4proto = ipv4_get_l4proto,
353 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
354 .tuple_to_nlattr = ipv4_tuple_to_nlattr,
355 .nlattr_tuple_size = ipv4_nlattr_tuple_size,
356 .nlattr_to_tuple = ipv4_nlattr_to_tuple,
357 .nla_policy = ipv4_nla_policy,
358 #endif
359 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
360 .ctl_table_path = nf_net_ipv4_netfilter_sysctl_path,
361 .ctl_table = ip_ct_sysctl_table,
362 #endif
363 .me = THIS_MODULE,
364 };
365
366 module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
367 &nf_conntrack_htable_size, 0600);
368
369 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
370 MODULE_ALIAS("ip_conntrack");
371 MODULE_LICENSE("GPL");
372
373 static int __init nf_conntrack_l3proto_ipv4_init(void)
374 {
375 int ret = 0;
376
377 need_conntrack();
378 nf_defrag_ipv4_enable();
379
380 ret = nf_register_sockopt(&so_getorigdst);
381 if (ret < 0) {
382 printk(KERN_ERR "Unable to register netfilter socket option\n");
383 return ret;
384 }
385
386 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp4);
387 if (ret < 0) {
388 printk("nf_conntrack_ipv4: can't register tcp.\n");
389 goto cleanup_sockopt;
390 }
391
392 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp4);
393 if (ret < 0) {
394 printk("nf_conntrack_ipv4: can't register udp.\n");
395 goto cleanup_tcp;
396 }
397
398 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmp);
399 if (ret < 0) {
400 printk("nf_conntrack_ipv4: can't register icmp.\n");
401 goto cleanup_udp;
402 }
403
404 ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4);
405 if (ret < 0) {
406 printk("nf_conntrack_ipv4: can't register ipv4\n");
407 goto cleanup_icmp;
408 }
409
410 ret = nf_register_hooks(ipv4_conntrack_ops,
411 ARRAY_SIZE(ipv4_conntrack_ops));
412 if (ret < 0) {
413 printk("nf_conntrack_ipv4: can't register hooks.\n");
414 goto cleanup_ipv4;
415 }
416 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
417 ret = nf_conntrack_ipv4_compat_init();
418 if (ret < 0)
419 goto cleanup_hooks;
420 #endif
421 return ret;
422 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
423 cleanup_hooks:
424 nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
425 #endif
426 cleanup_ipv4:
427 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
428 cleanup_icmp:
429 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
430 cleanup_udp:
431 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
432 cleanup_tcp:
433 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
434 cleanup_sockopt:
435 nf_unregister_sockopt(&so_getorigdst);
436 return ret;
437 }
438
439 static void __exit nf_conntrack_l3proto_ipv4_fini(void)
440 {
441 synchronize_net();
442 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
443 nf_conntrack_ipv4_compat_fini();
444 #endif
445 nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
446 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
447 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
448 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
449 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
450 nf_unregister_sockopt(&so_getorigdst);
451 }
452
453 module_init(nf_conntrack_l3proto_ipv4_init);
454 module_exit(nf_conntrack_l3proto_ipv4_fini);
455
456 void need_ipv4_conntrack(void)
457 {
458 return;
459 }
460 EXPORT_SYMBOL_GPL(need_ipv4_conntrack);
Linux 2.6 libata-dev (mirror)