1 // SPDX-License-Identifier: GPL-2.0-only
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>
12 #include "nf_internals.h"
14 /* Internal logging interface, which relies on the real
17 #define NFLOGGER_NAME_LEN 64
19 int sysctl_nf_log_all_netns __read_mostly;
20 EXPORT_SYMBOL(sysctl_nf_log_all_netns);
22 static struct nf_logger __rcu *loggers[NFPROTO_NUMPROTO][NF_LOG_TYPE_MAX] __read_mostly;
23 static DEFINE_MUTEX(nf_log_mutex);
25 #define nft_log_dereference(logger) \
26 rcu_dereference_protected(logger, lockdep_is_held(&nf_log_mutex))
28 static struct nf_logger *__find_logger(int pf, const char *str_logger)
30 struct nf_logger *log;
33 for (i = 0; i < NF_LOG_TYPE_MAX; i++) {
34 if (loggers[pf][i] == NULL)
37 log = nft_log_dereference(loggers[pf][i]);
38 if (!strncasecmp(str_logger, log->name, strlen(log->name)))
45 int nf_log_set(struct net *net, u_int8_t pf, const struct nf_logger *logger)
47 const struct nf_logger *log;
49 if (pf == NFPROTO_UNSPEC || pf >= ARRAY_SIZE(net->nf.nf_loggers))
52 mutex_lock(&nf_log_mutex);
53 log = nft_log_dereference(net->nf.nf_loggers[pf]);
55 rcu_assign_pointer(net->nf.nf_loggers[pf], logger);
57 mutex_unlock(&nf_log_mutex);
61 EXPORT_SYMBOL(nf_log_set);
63 void nf_log_unset(struct net *net, const struct nf_logger *logger)
66 const struct nf_logger *log;
68 mutex_lock(&nf_log_mutex);
69 for (i = 0; i < NFPROTO_NUMPROTO; i++) {
70 log = nft_log_dereference(net->nf.nf_loggers[i]);
72 RCU_INIT_POINTER(net->nf.nf_loggers[i], NULL);
74 mutex_unlock(&nf_log_mutex);
76 EXPORT_SYMBOL(nf_log_unset);
78 /* return EEXIST if the same logger is registered, 0 on success. */
79 int nf_log_register(u_int8_t pf, struct nf_logger *logger)
84 if (pf >= ARRAY_SIZE(init_net.nf.nf_loggers))
87 mutex_lock(&nf_log_mutex);
89 if (pf == NFPROTO_UNSPEC) {
90 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
91 if (rcu_access_pointer(loggers[i][logger->type])) {
96 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
97 rcu_assign_pointer(loggers[i][logger->type], logger);
99 if (rcu_access_pointer(loggers[pf][logger->type])) {
103 rcu_assign_pointer(loggers[pf][logger->type], logger);
107 mutex_unlock(&nf_log_mutex);
110 EXPORT_SYMBOL(nf_log_register);
112 void nf_log_unregister(struct nf_logger *logger)
114 const struct nf_logger *log;
117 mutex_lock(&nf_log_mutex);
118 for (i = 0; i < NFPROTO_NUMPROTO; i++) {
119 log = nft_log_dereference(loggers[i][logger->type]);
121 RCU_INIT_POINTER(loggers[i][logger->type], NULL);
123 mutex_unlock(&nf_log_mutex);
126 EXPORT_SYMBOL(nf_log_unregister);
128 int nf_log_bind_pf(struct net *net, u_int8_t pf,
129 const struct nf_logger *logger)
131 if (pf >= ARRAY_SIZE(net->nf.nf_loggers))
133 mutex_lock(&nf_log_mutex);
134 if (__find_logger(pf, logger->name) == NULL) {
135 mutex_unlock(&nf_log_mutex);
138 rcu_assign_pointer(net->nf.nf_loggers[pf], logger);
139 mutex_unlock(&nf_log_mutex);
142 EXPORT_SYMBOL(nf_log_bind_pf);
144 void nf_log_unbind_pf(struct net *net, u_int8_t pf)
146 if (pf >= ARRAY_SIZE(net->nf.nf_loggers))
148 mutex_lock(&nf_log_mutex);
149 RCU_INIT_POINTER(net->nf.nf_loggers[pf], NULL);
150 mutex_unlock(&nf_log_mutex);
152 EXPORT_SYMBOL(nf_log_unbind_pf);
154 int nf_logger_find_get(int pf, enum nf_log_type type)
156 struct nf_logger *logger;
159 if (pf == NFPROTO_INET) {
160 ret = nf_logger_find_get(NFPROTO_IPV4, type);
164 ret = nf_logger_find_get(NFPROTO_IPV6, type);
166 nf_logger_put(NFPROTO_IPV4, type);
174 logger = rcu_dereference(loggers[pf][type]);
178 if (try_module_get(logger->me))
184 EXPORT_SYMBOL_GPL(nf_logger_find_get);
186 void nf_logger_put(int pf, enum nf_log_type type)
188 struct nf_logger *logger;
190 if (pf == NFPROTO_INET) {
191 nf_logger_put(NFPROTO_IPV4, type);
192 nf_logger_put(NFPROTO_IPV6, type);
196 BUG_ON(loggers[pf][type] == NULL);
199 logger = rcu_dereference(loggers[pf][type]);
200 module_put(logger->me);
203 EXPORT_SYMBOL_GPL(nf_logger_put);
205 void nf_log_packet(struct net *net,
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, ...)
215 char prefix[NF_LOG_PREFIXLEN];
216 const struct nf_logger *logger;
220 logger = rcu_dereference(loggers[pf][loginfo->type]);
222 logger = rcu_dereference(net->nf.nf_loggers[pf]);
226 vsnprintf(prefix, sizeof(prefix), fmt, args);
228 logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
232 EXPORT_SYMBOL(nf_log_packet);
234 void nf_log_trace(struct net *net,
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, ...)
243 char prefix[NF_LOG_PREFIXLEN];
244 const struct nf_logger *logger;
247 logger = rcu_dereference(net->nf.nf_loggers[pf]);
250 vsnprintf(prefix, sizeof(prefix), fmt, args);
252 logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
256 EXPORT_SYMBOL(nf_log_trace);
258 #define S_SIZE (1024 - (sizeof(unsigned int) + 1))
262 char buf[S_SIZE + 1];
264 static struct nf_log_buf emergency, *emergency_ptr = &emergency;
266 __printf(2, 3) int nf_log_buf_add(struct nf_log_buf *m, const char *f, ...)
271 if (likely(m->count < S_SIZE)) {
273 len = vsnprintf(m->buf + m->count, S_SIZE - m->count, f, args);
275 if (likely(m->count + len < S_SIZE)) {
281 printk_once(KERN_ERR KBUILD_MODNAME " please increase S_SIZE\n");
284 EXPORT_SYMBOL_GPL(nf_log_buf_add);
286 struct nf_log_buf *nf_log_buf_open(void)
288 struct nf_log_buf *m = kmalloc(sizeof(*m), GFP_ATOMIC);
293 m = xchg(&emergency_ptr, NULL);
299 EXPORT_SYMBOL_GPL(nf_log_buf_open);
301 void nf_log_buf_close(struct nf_log_buf *m)
303 m->buf[m->count] = 0;
304 printk("%s\n", m->buf);
306 if (likely(m != &emergency))
313 EXPORT_SYMBOL_GPL(nf_log_buf_close);
315 #ifdef CONFIG_PROC_FS
316 static void *seq_start(struct seq_file *seq, loff_t *pos)
318 struct net *net = seq_file_net(seq);
320 mutex_lock(&nf_log_mutex);
322 if (*pos >= ARRAY_SIZE(net->nf.nf_loggers))
328 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
330 struct net *net = seq_file_net(s);
334 if (*pos >= ARRAY_SIZE(net->nf.nf_loggers))
340 static void seq_stop(struct seq_file *s, void *v)
342 mutex_unlock(&nf_log_mutex);
345 static int seq_show(struct seq_file *s, void *v)
348 const struct nf_logger *logger;
350 struct net *net = seq_file_net(s);
352 logger = nft_log_dereference(net->nf.nf_loggers[*pos]);
355 seq_printf(s, "%2lld NONE (", *pos);
357 seq_printf(s, "%2lld %s (", *pos, logger->name);
359 if (seq_has_overflowed(s))
362 for (i = 0; i < NF_LOG_TYPE_MAX; i++) {
363 if (loggers[*pos][i] == NULL)
366 logger = nft_log_dereference(loggers[*pos][i]);
367 seq_puts(s, logger->name);
368 if (i == 0 && loggers[*pos][i + 1] != NULL)
371 if (seq_has_overflowed(s))
377 if (seq_has_overflowed(s))
382 static const struct seq_operations nflog_seq_ops = {
391 static char nf_log_sysctl_fnames[NFPROTO_NUMPROTO-NFPROTO_UNSPEC][3];
392 static struct ctl_table nf_log_sysctl_table[NFPROTO_NUMPROTO+1];
393 static struct ctl_table_header *nf_log_sysctl_fhdr;
395 static struct ctl_table nf_log_sysctl_ftable[] = {
397 .procname = "nf_log_all_netns",
398 .data = &sysctl_nf_log_all_netns,
399 .maxlen = sizeof(sysctl_nf_log_all_netns),
401 .proc_handler = proc_dointvec,
406 static int nf_log_proc_dostring(struct ctl_table *table, int write,
407 void *buffer, size_t *lenp, loff_t *ppos)
409 const struct nf_logger *logger;
410 char buf[NFLOGGER_NAME_LEN];
412 int tindex = (unsigned long)table->extra1;
413 struct net *net = table->extra2;
416 struct ctl_table tmp = *table;
418 /* proc_dostring() can append to existing strings, so we need to
419 * initialize it as an empty string.
423 r = proc_dostring(&tmp, write, buffer, lenp, ppos);
427 if (!strcmp(buf, "NONE")) {
428 nf_log_unbind_pf(net, tindex);
431 mutex_lock(&nf_log_mutex);
432 logger = __find_logger(tindex, buf);
433 if (logger == NULL) {
434 mutex_unlock(&nf_log_mutex);
437 rcu_assign_pointer(net->nf.nf_loggers[tindex], logger);
438 mutex_unlock(&nf_log_mutex);
440 struct ctl_table tmp = *table;
443 mutex_lock(&nf_log_mutex);
444 logger = nft_log_dereference(net->nf.nf_loggers[tindex]);
446 strlcpy(buf, "NONE", sizeof(buf));
448 strlcpy(buf, logger->name, sizeof(buf));
449 mutex_unlock(&nf_log_mutex);
450 r = proc_dostring(&tmp, write, buffer, lenp, ppos);
456 static int netfilter_log_sysctl_init(struct net *net)
459 struct ctl_table *table;
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),
469 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
470 snprintf(nf_log_sysctl_fnames[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;
481 nf_log_sysctl_fhdr = register_net_sysctl(net, "net/netfilter",
482 nf_log_sysctl_ftable);
483 if (!nf_log_sysctl_fhdr)
487 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
488 table[i].extra2 = net;
490 net->nf.nf_log_dir_header = register_net_sysctl(net,
491 "net/netfilter/nf_log",
493 if (!net->nf.nf_log_dir_header)
499 if (!net_eq(net, &init_net))
502 unregister_net_sysctl_table(nf_log_sysctl_fhdr);
508 static void netfilter_log_sysctl_exit(struct net *net)
510 struct ctl_table *table;
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))
517 unregister_net_sysctl_table(nf_log_sysctl_fhdr);
520 static int netfilter_log_sysctl_init(struct net *net)
525 static void netfilter_log_sysctl_exit(struct net *net)
528 #endif /* CONFIG_SYSCTL */
530 static int __net_init nf_log_net_init(struct net *net)
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)))
539 ret = netfilter_log_sysctl_init(net);
546 #ifdef CONFIG_PROC_FS
547 remove_proc_entry("nf_log", net->nf.proc_netfilter);
552 static void __net_exit nf_log_net_exit(struct net *net)
554 netfilter_log_sysctl_exit(net);
555 #ifdef CONFIG_PROC_FS
556 remove_proc_entry("nf_log", net->nf.proc_netfilter);
560 static struct pernet_operations nf_log_net_ops = {
561 .init = nf_log_net_init,
562 .exit = nf_log_net_exit,
565 int __init netfilter_log_init(void)
567 return register_pernet_subsys(&nf_log_net_ops);