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/netfilter.h>
11 #include <linux/slab.h>
12 #include <linux/module.h>
13 #include <linux/skbuff.h>
14 #include <linux/proc_fs.h>
15 #include <linux/seq_file.h>
16 #include <linux/percpu.h>
17 #include <linux/netdevice.h>
18 #include <net/net_namespace.h>
19 #ifdef CONFIG_SYSCTL
20 #include <linux/sysctl.h>
21 #endif
22 
23 #include <net/netfilter/nf_conntrack.h>
24 #include <net/netfilter/nf_conntrack_core.h>
25 #include <net/netfilter/nf_conntrack_l3proto.h>
26 #include <net/netfilter/nf_conntrack_l4proto.h>
27 #include <net/netfilter/nf_conntrack_expect.h>
28 #include <net/netfilter/nf_conntrack_helper.h>
29 #include <net/netfilter/nf_conntrack_acct.h>
30 #include <net/netfilter/nf_conntrack_zones.h>
31 
32 MODULE_LICENSE("GPL");
33 
34 #ifdef CONFIG_PROC_FS
35 int
36 print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,
37             const struct nf_conntrack_l3proto *l3proto,
38             const struct nf_conntrack_l4proto *l4proto)
39 {
40 	return l3proto->print_tuple(s, tuple) || l4proto->print_tuple(s, tuple);
41 }
42 EXPORT_SYMBOL_GPL(print_tuple);
43 
44 struct ct_iter_state {
45 	struct seq_net_private p;
46 	unsigned int bucket;
47 };
48 
49 static struct hlist_nulls_node *ct_get_first(struct seq_file *seq)
50 {
51 	struct net *net = seq_file_net(seq);
52 	struct ct_iter_state *st = seq->private;
53 	struct hlist_nulls_node *n;
54 
55 	for (st->bucket = 0;
56 	     st->bucket < net->ct.htable_size;
57 	     st->bucket++) {
58 		n = rcu_dereference(net->ct.hash[st->bucket].first);
59 		if (!is_a_nulls(n))
60 			return n;
61 	}
62 	return NULL;
63 }
64 
65 static struct hlist_nulls_node *ct_get_next(struct seq_file *seq,
66 				      struct hlist_nulls_node *head)
67 {
68 	struct net *net = seq_file_net(seq);
69 	struct ct_iter_state *st = seq->private;
70 
71 	head = rcu_dereference(head->next);
72 	while (is_a_nulls(head)) {
73 		if (likely(get_nulls_value(head) == st->bucket)) {
74 			if (++st->bucket >= net->ct.htable_size)
75 				return NULL;
76 		}
77 		head = rcu_dereference(net->ct.hash[st->bucket].first);
78 	}
79 	return head;
80 }
81 
82 static struct hlist_nulls_node *ct_get_idx(struct seq_file *seq, loff_t pos)
83 {
84 	struct hlist_nulls_node *head = ct_get_first(seq);
85 
86 	if (head)
87 		while (pos && (head = ct_get_next(seq, head)))
88 			pos--;
89 	return pos ? NULL : head;
90 }
91 
92 static void *ct_seq_start(struct seq_file *seq, loff_t *pos)
93 	__acquires(RCU)
94 {
95 	rcu_read_lock();
96 	return ct_get_idx(seq, *pos);
97 }
98 
99 static void *ct_seq_next(struct seq_file *s, void *v, loff_t *pos)
100 {
101 	(*pos)++;
102 	return ct_get_next(s, v);
103 }
104 
105 static void ct_seq_stop(struct seq_file *s, void *v)
106 	__releases(RCU)
107 {
108 	rcu_read_unlock();
109 }
110 
111 /* return 0 on success, 1 in case of error */
112 static int ct_seq_show(struct seq_file *s, void *v)
113 {
114 	struct nf_conntrack_tuple_hash *hash = v;
115 	struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(hash);
116 	const struct nf_conntrack_l3proto *l3proto;
117 	const struct nf_conntrack_l4proto *l4proto;
118 	int ret = 0;
119 
120 	NF_CT_ASSERT(ct);
121 	if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
122 		return 0;
123 
124 	/* we only want to print DIR_ORIGINAL */
125 	if (NF_CT_DIRECTION(hash))
126 		goto release;
127 
128 	l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));
129 	NF_CT_ASSERT(l3proto);
130 	l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
131 	NF_CT_ASSERT(l4proto);
132 
133 	ret = -ENOSPC;
134 	if (seq_printf(s, "%-8s %u %-8s %u %ld ",
135 		       l3proto->name, nf_ct_l3num(ct),
136 		       l4proto->name, nf_ct_protonum(ct),
137 		       timer_pending(&ct->timeout)
138 		       ? (long)(ct->timeout.expires - jiffies)/HZ : 0) != 0)
139 		goto release;
140 
141 	if (l4proto->print_conntrack && l4proto->print_conntrack(s, ct))
142 		goto release;
143 
144 	if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
145 			l3proto, l4proto))
146 		goto release;
147 
148 	if (seq_print_acct(s, ct, IP_CT_DIR_ORIGINAL))
149 		goto release;
150 
151 	if (!(test_bit(IPS_SEEN_REPLY_BIT, &ct->status)))
152 		if (seq_printf(s, "[UNREPLIED] "))
153 			goto release;
154 
155 	if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
156 			l3proto, l4proto))
157 		goto release;
158 
159 	if (seq_print_acct(s, ct, IP_CT_DIR_REPLY))
160 		goto release;
161 
162 	if (test_bit(IPS_ASSURED_BIT, &ct->status))
163 		if (seq_printf(s, "[ASSURED] "))
164 			goto release;
165 
166 #if defined(CONFIG_NF_CONNTRACK_MARK)
167 	if (seq_printf(s, "mark=%u ", ct->mark))
168 		goto release;
169 #endif
170 
171 #ifdef CONFIG_NF_CONNTRACK_SECMARK
172 	if (seq_printf(s, "secmark=%u ", ct->secmark))
173 		goto release;
174 #endif
175 
176 #ifdef CONFIG_NF_CONNTRACK_ZONES
177 	if (seq_printf(s, "zone=%u ", nf_ct_zone(ct)))
178 		goto release;
179 #endif
180 
181 	if (seq_printf(s, "use=%u\n", atomic_read(&ct->ct_general.use)))
182 		goto release;
183 
184 	ret = 0;
185 release:
186 	nf_ct_put(ct);
187 	return 0;
188 }
189 
190 static const struct seq_operations ct_seq_ops = {
191 	.start = ct_seq_start,
192 	.next  = ct_seq_next,
193 	.stop  = ct_seq_stop,
194 	.show  = ct_seq_show
195 };
196 
197 static int ct_open(struct inode *inode, struct file *file)
198 {
199 	return seq_open_net(inode, file, &ct_seq_ops,
200 			sizeof(struct ct_iter_state));
201 }
202 
203 static const struct file_operations ct_file_ops = {
204 	.owner   = THIS_MODULE,
205 	.open    = ct_open,
206 	.read    = seq_read,
207 	.llseek  = seq_lseek,
208 	.release = seq_release_net,
209 };
210 
211 static void *ct_cpu_seq_start(struct seq_file *seq, loff_t *pos)
212 {
213 	struct net *net = seq_file_net(seq);
214 	int cpu;
215 
216 	if (*pos == 0)
217 		return SEQ_START_TOKEN;
218 
219 	for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
220 		if (!cpu_possible(cpu))
221 			continue;
222 		*pos = cpu + 1;
223 		return per_cpu_ptr(net->ct.stat, cpu);
224 	}
225 
226 	return NULL;
227 }
228 
229 static void *ct_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
230 {
231 	struct net *net = seq_file_net(seq);
232 	int cpu;
233 
234 	for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
235 		if (!cpu_possible(cpu))
236 			continue;
237 		*pos = cpu + 1;
238 		return per_cpu_ptr(net->ct.stat, cpu);
239 	}
240 
241 	return NULL;
242 }
243 
244 static void ct_cpu_seq_stop(struct seq_file *seq, void *v)
245 {
246 }
247 
248 static int ct_cpu_seq_show(struct seq_file *seq, void *v)
249 {
250 	struct net *net = seq_file_net(seq);
251 	unsigned int nr_conntracks = atomic_read(&net->ct.count);
252 	const struct ip_conntrack_stat *st = v;
253 
254 	if (v == SEQ_START_TOKEN) {
255 		seq_printf(seq, "entries  searched found new invalid ignore delete delete_list insert insert_failed drop early_drop icmp_error  expect_new expect_create expect_delete\n");
256 		return 0;
257 	}
258 
259 	seq_printf(seq, "%08x  %08x %08x %08x %08x %08x %08x %08x "
260 			"%08x %08x %08x %08x %08x  %08x %08x %08x \n",
261 		   nr_conntracks,
262 		   st->searched,
263 		   st->found,
264 		   st->new,
265 		   st->invalid,
266 		   st->ignore,
267 		   st->delete,
268 		   st->delete_list,
269 		   st->insert,
270 		   st->insert_failed,
271 		   st->drop,
272 		   st->early_drop,
273 		   st->error,
274 
275 		   st->expect_new,
276 		   st->expect_create,
277 		   st->expect_delete
278 		);
279 	return 0;
280 }
281 
282 static const struct seq_operations ct_cpu_seq_ops = {
283 	.start	= ct_cpu_seq_start,
284 	.next	= ct_cpu_seq_next,
285 	.stop	= ct_cpu_seq_stop,
286 	.show	= ct_cpu_seq_show,
287 };
288 
289 static int ct_cpu_seq_open(struct inode *inode, struct file *file)
290 {
291 	return seq_open_net(inode, file, &ct_cpu_seq_ops,
292 			    sizeof(struct seq_net_private));
293 }
294 
295 static const struct file_operations ct_cpu_seq_fops = {
296 	.owner	 = THIS_MODULE,
297 	.open	 = ct_cpu_seq_open,
298 	.read	 = seq_read,
299 	.llseek	 = seq_lseek,
300 	.release = seq_release_net,
301 };
302 
303 static int nf_conntrack_standalone_init_proc(struct net *net)
304 {
305 	struct proc_dir_entry *pde;
306 
307 	pde = proc_net_fops_create(net, "nf_conntrack", 0440, &ct_file_ops);
308 	if (!pde)
309 		goto out_nf_conntrack;
310 
311 	pde = proc_create("nf_conntrack", S_IRUGO, net->proc_net_stat,
312 			  &ct_cpu_seq_fops);
313 	if (!pde)
314 		goto out_stat_nf_conntrack;
315 	return 0;
316 
317 out_stat_nf_conntrack:
318 	proc_net_remove(net, "nf_conntrack");
319 out_nf_conntrack:
320 	return -ENOMEM;
321 }
322 
323 static void nf_conntrack_standalone_fini_proc(struct net *net)
324 {
325 	remove_proc_entry("nf_conntrack", net->proc_net_stat);
326 	proc_net_remove(net, "nf_conntrack");
327 }
328 #else
329 static int nf_conntrack_standalone_init_proc(struct net *net)
330 {
331 	return 0;
332 }
333 
334 static void nf_conntrack_standalone_fini_proc(struct net *net)
335 {
336 }
337 #endif /* CONFIG_PROC_FS */
338 
339 /* Sysctl support */
340 
341 #ifdef CONFIG_SYSCTL
342 /* Log invalid packets of a given protocol */
343 static int log_invalid_proto_min = 0;
344 static int log_invalid_proto_max = 255;
345 
346 static struct ctl_table_header *nf_ct_netfilter_header;
347 
348 static ctl_table nf_ct_sysctl_table[] = {
349 	{
350 		.procname	= "nf_conntrack_max",
351 		.data		= &nf_conntrack_max,
352 		.maxlen		= sizeof(int),
353 		.mode		= 0644,
354 		.proc_handler	= proc_dointvec,
355 	},
356 	{
357 		.procname	= "nf_conntrack_count",
358 		.data		= &init_net.ct.count,
359 		.maxlen		= sizeof(int),
360 		.mode		= 0444,
361 		.proc_handler	= proc_dointvec,
362 	},
363 	{
364 		.procname       = "nf_conntrack_buckets",
365 		.data           = &init_net.ct.htable_size,
366 		.maxlen         = sizeof(unsigned int),
367 		.mode           = 0444,
368 		.proc_handler   = proc_dointvec,
369 	},
370 	{
371 		.procname	= "nf_conntrack_checksum",
372 		.data		= &init_net.ct.sysctl_checksum,
373 		.maxlen		= sizeof(unsigned int),
374 		.mode		= 0644,
375 		.proc_handler	= proc_dointvec,
376 	},
377 	{
378 		.procname	= "nf_conntrack_log_invalid",
379 		.data		= &init_net.ct.sysctl_log_invalid,
380 		.maxlen		= sizeof(unsigned int),
381 		.mode		= 0644,
382 		.proc_handler	= proc_dointvec_minmax,
383 		.extra1		= &log_invalid_proto_min,
384 		.extra2		= &log_invalid_proto_max,
385 	},
386 	{
387 		.procname	= "nf_conntrack_expect_max",
388 		.data		= &nf_ct_expect_max,
389 		.maxlen		= sizeof(int),
390 		.mode		= 0644,
391 		.proc_handler	= proc_dointvec,
392 	},
393 	{ }
394 };
395 
396 #define NET_NF_CONNTRACK_MAX 2089
397 
398 static ctl_table nf_ct_netfilter_table[] = {
399 	{
400 		.procname	= "nf_conntrack_max",
401 		.data		= &nf_conntrack_max,
402 		.maxlen		= sizeof(int),
403 		.mode		= 0644,
404 		.proc_handler	= proc_dointvec,
405 	},
406 	{ }
407 };
408 
409 static struct ctl_path nf_ct_path[] = {
410 	{ .procname = "net", },
411 	{ }
412 };
413 
414 static int nf_conntrack_standalone_init_sysctl(struct net *net)
415 {
416 	struct ctl_table *table;
417 
418 	if (net_eq(net, &init_net)) {
419 		nf_ct_netfilter_header =
420 		       register_sysctl_paths(nf_ct_path, nf_ct_netfilter_table);
421 		if (!nf_ct_netfilter_header)
422 			goto out;
423 	}
424 
425 	table = kmemdup(nf_ct_sysctl_table, sizeof(nf_ct_sysctl_table),
426 			GFP_KERNEL);
427 	if (!table)
428 		goto out_kmemdup;
429 
430 	table[1].data = &net->ct.count;
431 	table[2].data = &net->ct.htable_size;
432 	table[3].data = &net->ct.sysctl_checksum;
433 	table[4].data = &net->ct.sysctl_log_invalid;
434 
435 	net->ct.sysctl_header = register_net_sysctl_table(net,
436 					nf_net_netfilter_sysctl_path, table);
437 	if (!net->ct.sysctl_header)
438 		goto out_unregister_netfilter;
439 
440 	return 0;
441 
442 out_unregister_netfilter:
443 	kfree(table);
444 out_kmemdup:
445 	if (net_eq(net, &init_net))
446 		unregister_sysctl_table(nf_ct_netfilter_header);
447 out:
448 	printk("nf_conntrack: can't register to sysctl.\n");
449 	return -ENOMEM;
450 }
451 
452 static void nf_conntrack_standalone_fini_sysctl(struct net *net)
453 {
454 	struct ctl_table *table;
455 
456 	if (net_eq(net, &init_net))
457 		unregister_sysctl_table(nf_ct_netfilter_header);
458 	table = net->ct.sysctl_header->ctl_table_arg;
459 	unregister_net_sysctl_table(net->ct.sysctl_header);
460 	kfree(table);
461 }
462 #else
463 static int nf_conntrack_standalone_init_sysctl(struct net *net)
464 {
465 	return 0;
466 }
467 
468 static void nf_conntrack_standalone_fini_sysctl(struct net *net)
469 {
470 }
471 #endif /* CONFIG_SYSCTL */
472 
473 static int nf_conntrack_net_init(struct net *net)
474 {
475 	int ret;
476 
477 	ret = nf_conntrack_init(net);
478 	if (ret < 0)
479 		goto out_init;
480 	ret = nf_conntrack_standalone_init_proc(net);
481 	if (ret < 0)
482 		goto out_proc;
483 	net->ct.sysctl_checksum = 1;
484 	net->ct.sysctl_log_invalid = 0;
485 	ret = nf_conntrack_standalone_init_sysctl(net);
486 	if (ret < 0)
487 		goto out_sysctl;
488 	return 0;
489 
490 out_sysctl:
491 	nf_conntrack_standalone_fini_proc(net);
492 out_proc:
493 	nf_conntrack_cleanup(net);
494 out_init:
495 	return ret;
496 }
497 
498 static void nf_conntrack_net_exit(struct net *net)
499 {
500 	nf_conntrack_standalone_fini_sysctl(net);
501 	nf_conntrack_standalone_fini_proc(net);
502 	nf_conntrack_cleanup(net);
503 }
504 
505 static struct pernet_operations nf_conntrack_net_ops = {
506 	.init = nf_conntrack_net_init,
507 	.exit = nf_conntrack_net_exit,
508 };
509 
510 static int __init nf_conntrack_standalone_init(void)
511 {
512 	return register_pernet_subsys(&nf_conntrack_net_ops);
513 }
514 
515 static void __exit nf_conntrack_standalone_fini(void)
516 {
517 	unregister_pernet_subsys(&nf_conntrack_net_ops);
518 }
519 
520 module_init(nf_conntrack_standalone_init);
521 module_exit(nf_conntrack_standalone_fini);
522 
523 /* Some modules need us, but don't depend directly on any symbol.
524    They should call this. */
525 void need_conntrack(void)
526 {
527 }
528 EXPORT_SYMBOL_GPL(need_conntrack);
529