1#include <linux/kernel.h>
2#include <linux/init.h>
3#include <linux/module.h>
4#include <linux/proc_fs.h>
5#include <linux/skbuff.h>
6#include <linux/netfilter.h>
7#include <linux/seq_file.h>
8#include <net/protocol.h>
9#include <net/netfilter/nf_log.h>
10
11#include "nf_internals.h"
12
13
14
15
16#define NFLOGGER_NAME_LEN 64
17
18int sysctl_nf_log_all_netns __read_mostly;
19EXPORT_SYMBOL(sysctl_nf_log_all_netns);
20
21static struct nf_logger __rcu *loggers[NFPROTO_NUMPROTO][NF_LOG_TYPE_MAX] __read_mostly;
22static DEFINE_MUTEX(nf_log_mutex);
23
24#define nft_log_dereference(logger) \
25 rcu_dereference_protected(logger, lockdep_is_held(&nf_log_mutex))
26
27static struct nf_logger *__find_logger(int pf, const char *str_logger)
28{
29 struct nf_logger *log;
30 int i;
31
32 for (i = 0; i < NF_LOG_TYPE_MAX; i++) {
33 if (loggers[pf][i] == NULL)
34 continue;
35
36 log = nft_log_dereference(loggers[pf][i]);
37 if (!strncasecmp(str_logger, log->name, strlen(log->name)))
38 return log;
39 }
40
41 return NULL;
42}
43
44int nf_log_set(struct net *net, u_int8_t pf, const struct nf_logger *logger)
45{
46 const struct nf_logger *log;
47
48 if (pf == NFPROTO_UNSPEC || pf >= ARRAY_SIZE(net->nf.nf_loggers))
49 return -EOPNOTSUPP;
50
51 mutex_lock(&nf_log_mutex);
52 log = nft_log_dereference(net->nf.nf_loggers[pf]);
53 if (log == NULL)
54 rcu_assign_pointer(net->nf.nf_loggers[pf], logger);
55
56 mutex_unlock(&nf_log_mutex);
57
58 return 0;
59}
60EXPORT_SYMBOL(nf_log_set);
61
62void nf_log_unset(struct net *net, const struct nf_logger *logger)
63{
64 int i;
65 const struct nf_logger *log;
66
67 mutex_lock(&nf_log_mutex);
68 for (i = 0; i < NFPROTO_NUMPROTO; i++) {
69 log = nft_log_dereference(net->nf.nf_loggers[i]);
70 if (log == logger)
71 RCU_INIT_POINTER(net->nf.nf_loggers[i], NULL);
72 }
73 mutex_unlock(&nf_log_mutex);
74}
75EXPORT_SYMBOL(nf_log_unset);
76
77
78int nf_log_register(u_int8_t pf, struct nf_logger *logger)
79{
80 int i;
81 int ret = 0;
82
83 if (pf >= ARRAY_SIZE(init_net.nf.nf_loggers))
84 return -EINVAL;
85
86 mutex_lock(&nf_log_mutex);
87
88 if (pf == NFPROTO_UNSPEC) {
89 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
90 if (rcu_access_pointer(loggers[i][logger->type])) {
91 ret = -EEXIST;
92 goto unlock;
93 }
94 }
95 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
96 rcu_assign_pointer(loggers[i][logger->type], logger);
97 } else {
98 if (rcu_access_pointer(loggers[pf][logger->type])) {
99 ret = -EEXIST;
100 goto unlock;
101 }
102 rcu_assign_pointer(loggers[pf][logger->type], logger);
103 }
104
105unlock:
106 mutex_unlock(&nf_log_mutex);
107 return ret;
108}
109EXPORT_SYMBOL(nf_log_register);
110
111void nf_log_unregister(struct nf_logger *logger)
112{
113 const struct nf_logger *log;
114 int i;
115
116 mutex_lock(&nf_log_mutex);
117 for (i = 0; i < NFPROTO_NUMPROTO; i++) {
118 log = nft_log_dereference(loggers[i][logger->type]);
119 if (log == logger)
120 RCU_INIT_POINTER(loggers[i][logger->type], NULL);
121 }
122 mutex_unlock(&nf_log_mutex);
123 synchronize_rcu();
124}
125EXPORT_SYMBOL(nf_log_unregister);
126
127int nf_log_bind_pf(struct net *net, u_int8_t pf,
128 const struct nf_logger *logger)
129{
130 if (pf >= ARRAY_SIZE(net->nf.nf_loggers))
131 return -EINVAL;
132 mutex_lock(&nf_log_mutex);
133 if (__find_logger(pf, logger->name) == NULL) {
134 mutex_unlock(&nf_log_mutex);
135 return -ENOENT;
136 }
137 rcu_assign_pointer(net->nf.nf_loggers[pf], logger);
138 mutex_unlock(&nf_log_mutex);
139 return 0;
140}
141EXPORT_SYMBOL(nf_log_bind_pf);
142
143void nf_log_unbind_pf(struct net *net, u_int8_t pf)
144{
145 if (pf >= ARRAY_SIZE(net->nf.nf_loggers))
146 return;
147 mutex_lock(&nf_log_mutex);
148 RCU_INIT_POINTER(net->nf.nf_loggers[pf], NULL);
149 mutex_unlock(&nf_log_mutex);
150}
151EXPORT_SYMBOL(nf_log_unbind_pf);
152
153void nf_logger_request_module(int pf, enum nf_log_type type)
154{
155 if (loggers[pf][type] == NULL)
156 request_module("nf-logger-%u-%u", pf, type);
157}
158EXPORT_SYMBOL_GPL(nf_logger_request_module);
159
160int nf_logger_find_get(int pf, enum nf_log_type type)
161{
162 struct nf_logger *logger;
163 int ret = -ENOENT;
164
165 if (pf == NFPROTO_INET) {
166 ret = nf_logger_find_get(NFPROTO_IPV4, type);
167 if (ret < 0)
168 return ret;
169
170 ret = nf_logger_find_get(NFPROTO_IPV6, type);
171 if (ret < 0) {
172 nf_logger_put(NFPROTO_IPV4, type);
173 return ret;
174 }
175
176 return 0;
177 }
178
179 if (rcu_access_pointer(loggers[pf][type]) == NULL)
180 request_module("nf-logger-%u-%u", pf, type);
181
182 rcu_read_lock();
183 logger = rcu_dereference(loggers[pf][type]);
184 if (logger == NULL)
185 goto out;
186
187 if (try_module_get(logger->me))
188 ret = 0;
189out:
190 rcu_read_unlock();
191 return ret;
192}
193EXPORT_SYMBOL_GPL(nf_logger_find_get);
194
195void nf_logger_put(int pf, enum nf_log_type type)
196{
197 struct nf_logger *logger;
198
199 if (pf == NFPROTO_INET) {
200 nf_logger_put(NFPROTO_IPV4, type);
201 nf_logger_put(NFPROTO_IPV6, type);
202 return;
203 }
204
205 BUG_ON(loggers[pf][type] == NULL);
206
207 rcu_read_lock();
208 logger = rcu_dereference(loggers[pf][type]);
209 module_put(logger->me);
210 rcu_read_unlock();
211}
212EXPORT_SYMBOL_GPL(nf_logger_put);
213
214void nf_log_packet(struct net *net,
215 u_int8_t pf,
216 unsigned int hooknum,
217 const struct sk_buff *skb,
218 const struct net_device *in,
219 const struct net_device *out,
220 const struct nf_loginfo *loginfo,
221 const char *fmt, ...)
222{
223 va_list args;
224 char prefix[NF_LOG_PREFIXLEN];
225 const struct nf_logger *logger;
226
227 rcu_read_lock();
228 if (loginfo != NULL)
229 logger = rcu_dereference(loggers[pf][loginfo->type]);
230 else
231 logger = rcu_dereference(net->nf.nf_loggers[pf]);
232
233 if (logger) {
234 va_start(args, fmt);
235 vsnprintf(prefix, sizeof(prefix), fmt, args);
236 va_end(args);
237 logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
238 }
239 rcu_read_unlock();
240}
241EXPORT_SYMBOL(nf_log_packet);
242
243void nf_log_trace(struct net *net,
244 u_int8_t pf,
245 unsigned int hooknum,
246 const struct sk_buff *skb,
247 const struct net_device *in,
248 const struct net_device *out,
249 const struct nf_loginfo *loginfo, const char *fmt, ...)
250{
251 va_list args;
252 char prefix[NF_LOG_PREFIXLEN];
253 const struct nf_logger *logger;
254
255 rcu_read_lock();
256 logger = rcu_dereference(net->nf.nf_loggers[pf]);
257 if (logger) {
258 va_start(args, fmt);
259 vsnprintf(prefix, sizeof(prefix), fmt, args);
260 va_end(args);
261 logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
262 }
263 rcu_read_unlock();
264}
265EXPORT_SYMBOL(nf_log_trace);
266
267#define S_SIZE (1024 - (sizeof(unsigned int) + 1))
268
269struct nf_log_buf {
270 unsigned int count;
271 char buf[S_SIZE + 1];
272};
273static struct nf_log_buf emergency, *emergency_ptr = &emergency;
274
275__printf(2, 3) int nf_log_buf_add(struct nf_log_buf *m, const char *f, ...)
276{
277 va_list args;
278 int len;
279
280 if (likely(m->count < S_SIZE)) {
281 va_start(args, f);
282 len = vsnprintf(m->buf + m->count, S_SIZE - m->count, f, args);
283 va_end(args);
284 if (likely(m->count + len < S_SIZE)) {
285 m->count += len;
286 return 0;
287 }
288 }
289 m->count = S_SIZE;
290 printk_once(KERN_ERR KBUILD_MODNAME " please increase S_SIZE\n");
291 return -1;
292}
293EXPORT_SYMBOL_GPL(nf_log_buf_add);
294
295struct nf_log_buf *nf_log_buf_open(void)
296{
297 struct nf_log_buf *m = kmalloc(sizeof(*m), GFP_ATOMIC);
298
299 if (unlikely(!m)) {
300 local_bh_disable();
301 do {
302 m = xchg(&emergency_ptr, NULL);
303 } while (!m);
304 }
305 m->count = 0;
306 return m;
307}
308EXPORT_SYMBOL_GPL(nf_log_buf_open);
309
310void nf_log_buf_close(struct nf_log_buf *m)
311{
312 m->buf[m->count] = 0;
313 printk("%s\n", m->buf);
314
315 if (likely(m != &emergency))
316 kfree(m);
317 else {
318 emergency_ptr = m;
319 local_bh_enable();
320 }
321}
322EXPORT_SYMBOL_GPL(nf_log_buf_close);
323
324#ifdef CONFIG_PROC_FS
325static void *seq_start(struct seq_file *seq, loff_t *pos)
326{
327 struct net *net = seq_file_net(seq);
328
329 mutex_lock(&nf_log_mutex);
330
331 if (*pos >= ARRAY_SIZE(net->nf.nf_loggers))
332 return NULL;
333
334 return pos;
335}
336
337static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
338{
339 struct net *net = seq_file_net(s);
340
341 (*pos)++;
342
343 if (*pos >= ARRAY_SIZE(net->nf.nf_loggers))
344 return NULL;
345
346 return pos;
347}
348
349static void seq_stop(struct seq_file *s, void *v)
350{
351 mutex_unlock(&nf_log_mutex);
352}
353
354static int seq_show(struct seq_file *s, void *v)
355{
356 loff_t *pos = v;
357 const struct nf_logger *logger;
358 int i;
359 struct net *net = seq_file_net(s);
360
361 logger = nft_log_dereference(net->nf.nf_loggers[*pos]);
362
363 if (!logger)
364 seq_printf(s, "%2lld NONE (", *pos);
365 else
366 seq_printf(s, "%2lld %s (", *pos, logger->name);
367
368 if (seq_has_overflowed(s))
369 return -ENOSPC;
370
371 for (i = 0; i < NF_LOG_TYPE_MAX; i++) {
372 if (loggers[*pos][i] == NULL)
373 continue;
374
375 logger = nft_log_dereference(loggers[*pos][i]);
376 seq_printf(s, "%s", logger->name);
377 if (i == 0 && loggers[*pos][i + 1] != NULL)
378 seq_puts(s, ",");
379
380 if (seq_has_overflowed(s))
381 return -ENOSPC;
382 }
383
384 seq_puts(s, ")\n");
385
386 if (seq_has_overflowed(s))
387 return -ENOSPC;
388 return 0;
389}
390
391static const struct seq_operations nflog_seq_ops = {
392 .start = seq_start,
393 .next = seq_next,
394 .stop = seq_stop,
395 .show = seq_show,
396};
397
398static int nflog_open(struct inode *inode, struct file *file)
399{
400 return seq_open_net(inode, file, &nflog_seq_ops,
401 sizeof(struct seq_net_private));
402}
403
404static const struct file_operations nflog_file_ops = {
405 .open = nflog_open,
406 .read = seq_read,
407 .llseek = seq_lseek,
408 .release = seq_release_net,
409};
410
411
412#endif
413
414#ifdef CONFIG_SYSCTL
415static char nf_log_sysctl_fnames[NFPROTO_NUMPROTO-NFPROTO_UNSPEC][3];
416static struct ctl_table nf_log_sysctl_table[NFPROTO_NUMPROTO+1];
417static struct ctl_table_header *nf_log_sysctl_fhdr;
418
419static struct ctl_table nf_log_sysctl_ftable[] = {
420 {
421 .procname = "nf_log_all_netns",
422 .data = &sysctl_nf_log_all_netns,
423 .maxlen = sizeof(sysctl_nf_log_all_netns),
424 .mode = 0644,
425 .proc_handler = proc_dointvec,
426 },
427 { }
428};
429
430static int nf_log_proc_dostring(struct ctl_table *table, int write,
431 void __user *buffer, size_t *lenp, loff_t *ppos)
432{
433 const struct nf_logger *logger;
434 char buf[NFLOGGER_NAME_LEN];
435 int r = 0;
436 int tindex = (unsigned long)table->extra1;
437 struct net *net = table->extra2;
438
439 if (write) {
440 struct ctl_table tmp = *table;
441
442 tmp.data = buf;
443 r = proc_dostring(&tmp, write, buffer, lenp, ppos);
444 if (r)
445 return r;
446
447 if (!strcmp(buf, "NONE")) {
448 nf_log_unbind_pf(net, tindex);
449 return 0;
450 }
451 mutex_lock(&nf_log_mutex);
452 logger = __find_logger(tindex, buf);
453 if (logger == NULL) {
454 mutex_unlock(&nf_log_mutex);
455 return -ENOENT;
456 }
457 rcu_assign_pointer(net->nf.nf_loggers[tindex], logger);
458 mutex_unlock(&nf_log_mutex);
459 } else {
460 mutex_lock(&nf_log_mutex);
461 logger = nft_log_dereference(net->nf.nf_loggers[tindex]);
462 if (!logger)
463 table->data = "NONE";
464 else
465 table->data = logger->name;
466 r = proc_dostring(table, write, buffer, lenp, ppos);
467 mutex_unlock(&nf_log_mutex);
468 }
469
470 return r;
471}
472
473static int netfilter_log_sysctl_init(struct net *net)
474{
475 int i;
476 struct ctl_table *table;
477
478 table = nf_log_sysctl_table;
479 if (!net_eq(net, &init_net)) {
480 table = kmemdup(nf_log_sysctl_table,
481 sizeof(nf_log_sysctl_table),
482 GFP_KERNEL);
483 if (!table)
484 goto err_alloc;
485 } else {
486 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
487 snprintf(nf_log_sysctl_fnames[i],
488 3, "%d", i);
489 nf_log_sysctl_table[i].procname =
490 nf_log_sysctl_fnames[i];
491 nf_log_sysctl_table[i].maxlen = NFLOGGER_NAME_LEN;
492 nf_log_sysctl_table[i].mode = 0644;
493 nf_log_sysctl_table[i].proc_handler =
494 nf_log_proc_dostring;
495 nf_log_sysctl_table[i].extra1 =
496 (void *)(unsigned long) i;
497 }
498 nf_log_sysctl_fhdr = register_net_sysctl(net, "net/netfilter",
499 nf_log_sysctl_ftable);
500 if (!nf_log_sysctl_fhdr)
501 goto err_freg;
502 }
503
504 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
505 table[i].extra2 = net;
506
507 net->nf.nf_log_dir_header = register_net_sysctl(net,
508 "net/netfilter/nf_log",
509 table);
510 if (!net->nf.nf_log_dir_header)
511 goto err_reg;
512
513 return 0;
514
515err_reg:
516 if (!net_eq(net, &init_net))
517 kfree(table);
518 else
519 unregister_net_sysctl_table(nf_log_sysctl_fhdr);
520err_freg:
521err_alloc:
522 return -ENOMEM;
523}
524
525static void netfilter_log_sysctl_exit(struct net *net)
526{
527 struct ctl_table *table;
528
529 table = net->nf.nf_log_dir_header->ctl_table_arg;
530 unregister_net_sysctl_table(net->nf.nf_log_dir_header);
531 if (!net_eq(net, &init_net))
532 kfree(table);
533 else
534 unregister_net_sysctl_table(nf_log_sysctl_fhdr);
535}
536#else
537static int netfilter_log_sysctl_init(struct net *net)
538{
539 return 0;
540}
541
542static void netfilter_log_sysctl_exit(struct net *net)
543{
544}
545#endif
546
547static int __net_init nf_log_net_init(struct net *net)
548{
549 int ret = -ENOMEM;
550
551#ifdef CONFIG_PROC_FS
552 if (!proc_create("nf_log", S_IRUGO,
553 net->nf.proc_netfilter, &nflog_file_ops))
554 return ret;
555#endif
556 ret = netfilter_log_sysctl_init(net);
557 if (ret < 0)
558 goto out_sysctl;
559
560 return 0;
561
562out_sysctl:
563#ifdef CONFIG_PROC_FS
564 remove_proc_entry("nf_log", net->nf.proc_netfilter);
565#endif
566 return ret;
567}
568
569static void __net_exit nf_log_net_exit(struct net *net)
570{
571 netfilter_log_sysctl_exit(net);
572#ifdef CONFIG_PROC_FS
573 remove_proc_entry("nf_log", net->nf.proc_netfilter);
574#endif
575}
576
577static struct pernet_operations nf_log_net_ops = {
578 .init = nf_log_net_init,
579 .exit = nf_log_net_exit,
580};
581
582int __init netfilter_log_init(void)
583{
584 return register_pernet_subsys(&nf_log_net_ops);
585}
586
