1
2#include <linux/kernel.h>
3#include <linux/init.h>
4#include <linux/module.h>
5#include <linux/proc_fs.h>
6#include <linux/skbuff.h>
7#include <linux/netfilter.h>
8#include <linux/seq_file.h>
9#include <net/protocol.h>
10#include <net/netfilter/nf_log.h>
11
12#include "nf_internals.h"
13
14
15
16
17#define NFLOGGER_NAME_LEN 64
18
19int sysctl_nf_log_all_netns __read_mostly;
20EXPORT_SYMBOL(sysctl_nf_log_all_netns);
21
22static struct nf_logger __rcu *loggers[NFPROTO_NUMPROTO][NF_LOG_TYPE_MAX] __read_mostly;
23static DEFINE_MUTEX(nf_log_mutex);
24
25#define nft_log_dereference(logger) \
26 rcu_dereference_protected(logger, lockdep_is_held(&nf_log_mutex))
27
28static struct nf_logger *__find_logger(int pf, const char *str_logger)
29{
30 struct nf_logger *log;
31 int i;
32
33 for (i = 0; i < NF_LOG_TYPE_MAX; i++) {
34 if (loggers[pf][i] == NULL)
35 continue;
36
37 log = nft_log_dereference(loggers[pf][i]);
38 if (!strncasecmp(str_logger, log->name, strlen(log->name)))
39 return log;
40 }
41
42 return NULL;
43}
44
45int nf_log_set(struct net *net, u_int8_t pf, const struct nf_logger *logger)
46{
47 const struct nf_logger *log;
48
49 if (pf == NFPROTO_UNSPEC || pf >= ARRAY_SIZE(net->nf.nf_loggers))
50 return -EOPNOTSUPP;
51
52 mutex_lock(&nf_log_mutex);
53 log = nft_log_dereference(net->nf.nf_loggers[pf]);
54 if (log == NULL)
55 rcu_assign_pointer(net->nf.nf_loggers[pf], logger);
56
57 mutex_unlock(&nf_log_mutex);
58
59 return 0;
60}
61EXPORT_SYMBOL(nf_log_set);
62
63void nf_log_unset(struct net *net, const struct nf_logger *logger)
64{
65 int i;
66 const struct nf_logger *log;
67
68 mutex_lock(&nf_log_mutex);
69 for (i = 0; i < NFPROTO_NUMPROTO; i++) {
70 log = nft_log_dereference(net->nf.nf_loggers[i]);
71 if (log == logger)
72 RCU_INIT_POINTER(net->nf.nf_loggers[i], NULL);
73 }
74 mutex_unlock(&nf_log_mutex);
75}
76EXPORT_SYMBOL(nf_log_unset);
77
78
79int nf_log_register(u_int8_t pf, struct nf_logger *logger)
80{
81 int i;
82 int ret = 0;
83
84 if (pf >= ARRAY_SIZE(init_net.nf.nf_loggers))
85 return -EINVAL;
86
87 mutex_lock(&nf_log_mutex);
88
89 if (pf == NFPROTO_UNSPEC) {
90 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
91 if (rcu_access_pointer(loggers[i][logger->type])) {
92 ret = -EEXIST;
93 goto unlock;
94 }
95 }
96 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
97 rcu_assign_pointer(loggers[i][logger->type], logger);
98 } else {
99 if (rcu_access_pointer(loggers[pf][logger->type])) {
100 ret = -EEXIST;
101 goto unlock;
102 }
103 rcu_assign_pointer(loggers[pf][logger->type], logger);
104 }
105
106unlock:
107 mutex_unlock(&nf_log_mutex);
108 return ret;
109}
110EXPORT_SYMBOL(nf_log_register);
111
112void nf_log_unregister(struct nf_logger *logger)
113{
114 const struct nf_logger *log;
115 int i;
116
117 mutex_lock(&nf_log_mutex);
118 for (i = 0; i < NFPROTO_NUMPROTO; i++) {
119 log = nft_log_dereference(loggers[i][logger->type]);
120 if (log == logger)
121 RCU_INIT_POINTER(loggers[i][logger->type], NULL);
122 }
123 mutex_unlock(&nf_log_mutex);
124 synchronize_rcu();
125}
126EXPORT_SYMBOL(nf_log_unregister);
127
128int nf_log_bind_pf(struct net *net, u_int8_t pf,
129 const struct nf_logger *logger)
130{
131 if (pf >= ARRAY_SIZE(net->nf.nf_loggers))
132 return -EINVAL;
133 mutex_lock(&nf_log_mutex);
134 if (__find_logger(pf, logger->name) == NULL) {
135 mutex_unlock(&nf_log_mutex);
136 return -ENOENT;
137 }
138 rcu_assign_pointer(net->nf.nf_loggers[pf], logger);
139 mutex_unlock(&nf_log_mutex);
140 return 0;
141}
142EXPORT_SYMBOL(nf_log_bind_pf);
143
144void nf_log_unbind_pf(struct net *net, u_int8_t pf)
145{
146 if (pf >= ARRAY_SIZE(net->nf.nf_loggers))
147 return;
148 mutex_lock(&nf_log_mutex);
149 RCU_INIT_POINTER(net->nf.nf_loggers[pf], NULL);
150 mutex_unlock(&nf_log_mutex);
151}
152EXPORT_SYMBOL(nf_log_unbind_pf);
153
154int nf_logger_find_get(int pf, enum nf_log_type type)
155{
156 struct nf_logger *logger;
157 int ret = -ENOENT;
158
159 if (pf == NFPROTO_INET) {
160 ret = nf_logger_find_get(NFPROTO_IPV4, type);
161 if (ret < 0)
162 return ret;
163
164 ret = nf_logger_find_get(NFPROTO_IPV6, type);
165 if (ret < 0) {
166 nf_logger_put(NFPROTO_IPV4, type);
167 return ret;
168 }
169
170 return 0;
171 }
172
173 rcu_read_lock();
174 logger = rcu_dereference(loggers[pf][type]);
175 if (logger == NULL)
176 goto out;
177
178 if (try_module_get(logger->me))
179 ret = 0;
180out:
181 rcu_read_unlock();
182 return ret;
183}
184EXPORT_SYMBOL_GPL(nf_logger_find_get);
185
186void nf_logger_put(int pf, enum nf_log_type type)
187{
188 struct nf_logger *logger;
189
190 if (pf == NFPROTO_INET) {
191 nf_logger_put(NFPROTO_IPV4, type);
192 nf_logger_put(NFPROTO_IPV6, type);
193 return;
194 }
195
196 BUG_ON(loggers[pf][type] == NULL);
197
198 rcu_read_lock();
199 logger = rcu_dereference(loggers[pf][type]);
200 module_put(logger->me);
201 rcu_read_unlock();
202}
203EXPORT_SYMBOL_GPL(nf_logger_put);
204
205void nf_log_packet(struct net *net,
206 u_int8_t pf,
207 unsigned int hooknum,
208 const struct sk_buff *skb,
209 const struct net_device *in,
210 const struct net_device *out,
211 const struct nf_loginfo *loginfo,
212 const char *fmt, ...)
213{
214 va_list args;
215 char prefix[NF_LOG_PREFIXLEN];
216 const struct nf_logger *logger;
217
218 rcu_read_lock();
219 if (loginfo != NULL)
220 logger = rcu_dereference(loggers[pf][loginfo->type]);
221 else
222 logger = rcu_dereference(net->nf.nf_loggers[pf]);
223
224 if (logger) {
225 va_start(args, fmt);
226 vsnprintf(prefix, sizeof(prefix), fmt, args);
227 va_end(args);
228 logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
229 }
230 rcu_read_unlock();
231}
232EXPORT_SYMBOL(nf_log_packet);
233
234void nf_log_trace(struct net *net,
235 u_int8_t pf,
236 unsigned int hooknum,
237 const struct sk_buff *skb,
238 const struct net_device *in,
239 const struct net_device *out,
240 const struct nf_loginfo *loginfo, const char *fmt, ...)
241{
242 va_list args;
243 char prefix[NF_LOG_PREFIXLEN];
244 const struct nf_logger *logger;
245
246 rcu_read_lock();
247 logger = rcu_dereference(net->nf.nf_loggers[pf]);
248 if (logger) {
249 va_start(args, fmt);
250 vsnprintf(prefix, sizeof(prefix), fmt, args);
251 va_end(args);
252 logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
253 }
254 rcu_read_unlock();
255}
256EXPORT_SYMBOL(nf_log_trace);
257
258#define S_SIZE (1024 - (sizeof(unsigned int) + 1))
259
260struct nf_log_buf {
261 unsigned int count;
262 char buf[S_SIZE + 1];
263};
264static struct nf_log_buf emergency, *emergency_ptr = &emergency;
265
266__printf(2, 3) int nf_log_buf_add(struct nf_log_buf *m, const char *f, ...)
267{
268 va_list args;
269 int len;
270
271 if (likely(m->count < S_SIZE)) {
272 va_start(args, f);
273 len = vsnprintf(m->buf + m->count, S_SIZE - m->count, f, args);
274 va_end(args);
275 if (likely(m->count + len < S_SIZE)) {
276 m->count += len;
277 return 0;
278 }
279 }
280 m->count = S_SIZE;
281 printk_once(KERN_ERR KBUILD_MODNAME " please increase S_SIZE\n");
282 return -1;
283}
284EXPORT_SYMBOL_GPL(nf_log_buf_add);
285
286struct nf_log_buf *nf_log_buf_open(void)
287{
288 struct nf_log_buf *m = kmalloc(sizeof(*m), GFP_ATOMIC);
289
290 if (unlikely(!m)) {
291 local_bh_disable();
292 do {
293 m = xchg(&emergency_ptr, NULL);
294 } while (!m);
295 }
296 m->count = 0;
297 return m;
298}
299EXPORT_SYMBOL_GPL(nf_log_buf_open);
300
301void nf_log_buf_close(struct nf_log_buf *m)
302{
303 m->buf[m->count] = 0;
304 printk("%s\n", m->buf);
305
306 if (likely(m != &emergency))
307 kfree(m);
308 else {
309 emergency_ptr = m;
310 local_bh_enable();
311 }
312}
313EXPORT_SYMBOL_GPL(nf_log_buf_close);
314
315#ifdef CONFIG_PROC_FS
316static void *seq_start(struct seq_file *seq, loff_t *pos)
317{
318 struct net *net = seq_file_net(seq);
319
320 mutex_lock(&nf_log_mutex);
321
322 if (*pos >= ARRAY_SIZE(net->nf.nf_loggers))
323 return NULL;
324
325 return pos;
326}
327
328static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
329{
330 struct net *net = seq_file_net(s);
331
332 (*pos)++;
333
334 if (*pos >= ARRAY_SIZE(net->nf.nf_loggers))
335 return NULL;
336
337 return pos;
338}
339
340static void seq_stop(struct seq_file *s, void *v)
341{
342 mutex_unlock(&nf_log_mutex);
343}
344
345static int seq_show(struct seq_file *s, void *v)
346{
347 loff_t *pos = v;
348 const struct nf_logger *logger;
349 int i;
350 struct net *net = seq_file_net(s);
351
352 logger = nft_log_dereference(net->nf.nf_loggers[*pos]);
353
354 if (!logger)
355 seq_printf(s, "%2lld NONE (", *pos);
356 else
357 seq_printf(s, "%2lld %s (", *pos, logger->name);
358
359 if (seq_has_overflowed(s))
360 return -ENOSPC;
361
362 for (i = 0; i < NF_LOG_TYPE_MAX; i++) {
363 if (loggers[*pos][i] == NULL)
364 continue;
365
366 logger = nft_log_dereference(loggers[*pos][i]);
367 seq_puts(s, logger->name);
368 if (i == 0 && loggers[*pos][i + 1] != NULL)
369 seq_puts(s, ",");
370
371 if (seq_has_overflowed(s))
372 return -ENOSPC;
373 }
374
375 seq_puts(s, ")\n");
376
377 if (seq_has_overflowed(s))
378 return -ENOSPC;
379 return 0;
380}
381
382static const struct seq_operations nflog_seq_ops = {
383 .start = seq_start,
384 .next = seq_next,
385 .stop = seq_stop,
386 .show = seq_show,
387};
388#endif
389
390#ifdef CONFIG_SYSCTL
391static char nf_log_sysctl_fnames[NFPROTO_NUMPROTO-NFPROTO_UNSPEC][3];
392static struct ctl_table nf_log_sysctl_table[NFPROTO_NUMPROTO+1];
393static struct ctl_table_header *nf_log_sysctl_fhdr;
394
395static struct ctl_table nf_log_sysctl_ftable[] = {
396 {
397 .procname = "nf_log_all_netns",
398 .data = &sysctl_nf_log_all_netns,
399 .maxlen = sizeof(sysctl_nf_log_all_netns),
400 .mode = 0644,
401 .proc_handler = proc_dointvec,
402 },
403 { }
404};
405
406static int nf_log_proc_dostring(struct ctl_table *table, int write,
407 void *buffer, size_t *lenp, loff_t *ppos)
408{
409 const struct nf_logger *logger;
410 char buf[NFLOGGER_NAME_LEN];
411 int r = 0;
412 int tindex = (unsigned long)table->extra1;
413 struct net *net = table->extra2;
414
415 if (write) {
416 struct ctl_table tmp = *table;
417
418
419
420
421 buf[0] = '\0';
422 tmp.data = buf;
423 r = proc_dostring(&tmp, write, buffer, lenp, ppos);
424 if (r)
425 return r;
426
427 if (!strcmp(buf, "NONE")) {
428 nf_log_unbind_pf(net, tindex);
429 return 0;
430 }
431 mutex_lock(&nf_log_mutex);
432 logger = __find_logger(tindex, buf);
433 if (logger == NULL) {
434 mutex_unlock(&nf_log_mutex);
435 return -ENOENT;
436 }
437 rcu_assign_pointer(net->nf.nf_loggers[tindex], logger);
438 mutex_unlock(&nf_log_mutex);
439 } else {
440 struct ctl_table tmp = *table;
441
442 tmp.data = buf;
443 mutex_lock(&nf_log_mutex);
444 logger = nft_log_dereference(net->nf.nf_loggers[tindex]);
445 if (!logger)
446 strlcpy(buf, "NONE", sizeof(buf));
447 else
448 strlcpy(buf, logger->name, sizeof(buf));
449 mutex_unlock(&nf_log_mutex);
450 r = proc_dostring(&tmp, write, buffer, lenp, ppos);
451 }
452
453 return r;
454}
455
456static int netfilter_log_sysctl_init(struct net *net)
457{
458 int i;
459 struct ctl_table *table;
460
461 table = nf_log_sysctl_table;
462 if (!net_eq(net, &init_net)) {
463 table = kmemdup(nf_log_sysctl_table,
464 sizeof(nf_log_sysctl_table),
465 GFP_KERNEL);
466 if (!table)
467 goto err_alloc;
468 } else {
469 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
470 snprintf(nf_log_sysctl_fnames[i],
471 3, "%d", i);
472 nf_log_sysctl_table[i].procname =
473 nf_log_sysctl_fnames[i];
474 nf_log_sysctl_table[i].maxlen = NFLOGGER_NAME_LEN;
475 nf_log_sysctl_table[i].mode = 0644;
476 nf_log_sysctl_table[i].proc_handler =
477 nf_log_proc_dostring;
478 nf_log_sysctl_table[i].extra1 =
479 (void *)(unsigned long) i;
480 }
481 nf_log_sysctl_fhdr = register_net_sysctl(net, "net/netfilter",
482 nf_log_sysctl_ftable);
483 if (!nf_log_sysctl_fhdr)
484 goto err_freg;
485 }
486
487 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
488 table[i].extra2 = net;
489
490 net->nf.nf_log_dir_header = register_net_sysctl(net,
491 "net/netfilter/nf_log",
492 table);
493 if (!net->nf.nf_log_dir_header)
494 goto err_reg;
495
496 return 0;
497
498err_reg:
499 if (!net_eq(net, &init_net))
500 kfree(table);
501 else
502 unregister_net_sysctl_table(nf_log_sysctl_fhdr);
503err_freg:
504err_alloc:
505 return -ENOMEM;
506}
507
508static void netfilter_log_sysctl_exit(struct net *net)
509{
510 struct ctl_table *table;
511
512 table = net->nf.nf_log_dir_header->ctl_table_arg;
513 unregister_net_sysctl_table(net->nf.nf_log_dir_header);
514 if (!net_eq(net, &init_net))
515 kfree(table);
516 else
517 unregister_net_sysctl_table(nf_log_sysctl_fhdr);
518}
519#else
520static int netfilter_log_sysctl_init(struct net *net)
521{
522 return 0;
523}
524
525static void netfilter_log_sysctl_exit(struct net *net)
526{
527}
528#endif
529
530static int __net_init nf_log_net_init(struct net *net)
531{
532 int ret = -ENOMEM;
533
534#ifdef CONFIG_PROC_FS
535 if (!proc_create_net("nf_log", 0444, net->nf.proc_netfilter,
536 &nflog_seq_ops, sizeof(struct seq_net_private)))
537 return ret;
538#endif
539 ret = netfilter_log_sysctl_init(net);
540 if (ret < 0)
541 goto out_sysctl;
542
543 return 0;
544
545out_sysctl:
546#ifdef CONFIG_PROC_FS
547 remove_proc_entry("nf_log", net->nf.proc_netfilter);
548#endif
549 return ret;
550}
551
552static void __net_exit nf_log_net_exit(struct net *net)
553{
554 netfilter_log_sysctl_exit(net);
555#ifdef CONFIG_PROC_FS
556 remove_proc_entry("nf_log", net->nf.proc_netfilter);
557#endif
558}
559
560static struct pernet_operations nf_log_net_ops = {
561 .init = nf_log_net_init,
562 .exit = nf_log_net_exit,
563};
564
565int __init netfilter_log_init(void)
566{
567 return register_pernet_subsys(&nf_log_net_ops);
568}
569
