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);
197 logger = rcu_dereference(loggers[pf][type]);
201 module_put(logger->me);
204 EXPORT_SYMBOL_GPL(nf_logger_put);
206 void nf_log_packet(struct net *net,
208 unsigned int hooknum,
209 const struct sk_buff *skb,
210 const struct net_device *in,
211 const struct net_device *out,
212 const struct nf_loginfo *loginfo,
213 const char *fmt, ...)
216 char prefix[NF_LOG_PREFIXLEN];
217 const struct nf_logger *logger;
221 logger = rcu_dereference(loggers[pf][loginfo->type]);
223 logger = rcu_dereference(net->nf.nf_loggers[pf]);
227 vsnprintf(prefix, sizeof(prefix), fmt, args);
229 logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
233 EXPORT_SYMBOL(nf_log_packet);
235 void nf_log_trace(struct net *net,
237 unsigned int hooknum,
238 const struct sk_buff *skb,
239 const struct net_device *in,
240 const struct net_device *out,
241 const struct nf_loginfo *loginfo, const char *fmt, ...)
244 char prefix[NF_LOG_PREFIXLEN];
245 const struct nf_logger *logger;
248 logger = rcu_dereference(net->nf.nf_loggers[pf]);
251 vsnprintf(prefix, sizeof(prefix), fmt, args);
253 logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
257 EXPORT_SYMBOL(nf_log_trace);
259 #define S_SIZE (1024 - (sizeof(unsigned int) + 1))
263 char buf[S_SIZE + 1];
265 static struct nf_log_buf emergency, *emergency_ptr = &emergency;
267 __printf(2, 3) int nf_log_buf_add(struct nf_log_buf *m, const char *f, ...)
272 if (likely(m->count < S_SIZE)) {
274 len = vsnprintf(m->buf + m->count, S_SIZE - m->count, f, args);
276 if (likely(m->count + len < S_SIZE)) {
282 printk_once(KERN_ERR KBUILD_MODNAME " please increase S_SIZE\n");
285 EXPORT_SYMBOL_GPL(nf_log_buf_add);
287 struct nf_log_buf *nf_log_buf_open(void)
289 struct nf_log_buf *m = kmalloc(sizeof(*m), GFP_ATOMIC);
294 m = xchg(&emergency_ptr, NULL);
300 EXPORT_SYMBOL_GPL(nf_log_buf_open);
302 void nf_log_buf_close(struct nf_log_buf *m)
304 m->buf[m->count] = 0;
305 printk("%s\n", m->buf);
307 if (likely(m != &emergency))
314 EXPORT_SYMBOL_GPL(nf_log_buf_close);
316 #ifdef CONFIG_PROC_FS
317 static void *seq_start(struct seq_file *seq, loff_t *pos)
319 struct net *net = seq_file_net(seq);
321 mutex_lock(&nf_log_mutex);
323 if (*pos >= ARRAY_SIZE(net->nf.nf_loggers))
329 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
331 struct net *net = seq_file_net(s);
335 if (*pos >= ARRAY_SIZE(net->nf.nf_loggers))
341 static void seq_stop(struct seq_file *s, void *v)
343 mutex_unlock(&nf_log_mutex);
346 static int seq_show(struct seq_file *s, void *v)
349 const struct nf_logger *logger;
351 struct net *net = seq_file_net(s);
353 logger = nft_log_dereference(net->nf.nf_loggers[*pos]);
356 seq_printf(s, "%2lld NONE (", *pos);
358 seq_printf(s, "%2lld %s (", *pos, logger->name);
360 if (seq_has_overflowed(s))
363 for (i = 0; i < NF_LOG_TYPE_MAX; i++) {
364 if (loggers[*pos][i] == NULL)
367 logger = nft_log_dereference(loggers[*pos][i]);
368 seq_puts(s, logger->name);
369 if (i == 0 && loggers[*pos][i + 1] != NULL)
372 if (seq_has_overflowed(s))
378 if (seq_has_overflowed(s))
383 static const struct seq_operations nflog_seq_ops = {
392 static char nf_log_sysctl_fnames[NFPROTO_NUMPROTO-NFPROTO_UNSPEC][3];
393 static struct ctl_table nf_log_sysctl_table[NFPROTO_NUMPROTO+1];
394 static struct ctl_table_header *nf_log_sysctl_fhdr;
396 static struct ctl_table nf_log_sysctl_ftable[] = {
398 .procname = "nf_log_all_netns",
399 .data = &sysctl_nf_log_all_netns,
400 .maxlen = sizeof(sysctl_nf_log_all_netns),
402 .proc_handler = proc_dointvec,
407 static int nf_log_proc_dostring(struct ctl_table *table, int write,
408 void *buffer, size_t *lenp, loff_t *ppos)
410 const struct nf_logger *logger;
411 char buf[NFLOGGER_NAME_LEN];
413 int tindex = (unsigned long)table->extra1;
414 struct net *net = table->extra2;
417 struct ctl_table tmp = *table;
419 /* proc_dostring() can append to existing strings, so we need to
420 * initialize it as an empty string.
424 r = proc_dostring(&tmp, write, buffer, lenp, ppos);
428 if (!strcmp(buf, "NONE")) {
429 nf_log_unbind_pf(net, tindex);
432 mutex_lock(&nf_log_mutex);
433 logger = __find_logger(tindex, buf);
434 if (logger == NULL) {
435 mutex_unlock(&nf_log_mutex);
438 rcu_assign_pointer(net->nf.nf_loggers[tindex], logger);
439 mutex_unlock(&nf_log_mutex);
441 struct ctl_table tmp = *table;
444 mutex_lock(&nf_log_mutex);
445 logger = nft_log_dereference(net->nf.nf_loggers[tindex]);
447 strscpy(buf, "NONE", sizeof(buf));
449 strscpy(buf, logger->name, sizeof(buf));
450 mutex_unlock(&nf_log_mutex);
451 r = proc_dostring(&tmp, write, buffer, lenp, ppos);
457 static int netfilter_log_sysctl_init(struct net *net)
460 struct ctl_table *table;
462 table = nf_log_sysctl_table;
463 if (!net_eq(net, &init_net)) {
464 table = kmemdup(nf_log_sysctl_table,
465 sizeof(nf_log_sysctl_table),
470 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
471 snprintf(nf_log_sysctl_fnames[i],
473 nf_log_sysctl_table[i].procname =
474 nf_log_sysctl_fnames[i];
475 nf_log_sysctl_table[i].maxlen = NFLOGGER_NAME_LEN;
476 nf_log_sysctl_table[i].mode = 0644;
477 nf_log_sysctl_table[i].proc_handler =
478 nf_log_proc_dostring;
479 nf_log_sysctl_table[i].extra1 =
480 (void *)(unsigned long) i;
482 nf_log_sysctl_fhdr = register_net_sysctl(net, "net/netfilter",
483 nf_log_sysctl_ftable);
484 if (!nf_log_sysctl_fhdr)
488 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
489 table[i].extra2 = net;
491 net->nf.nf_log_dir_header = register_net_sysctl_sz(net,
492 "net/netfilter/nf_log",
494 ARRAY_SIZE(nf_log_sysctl_table));
495 if (!net->nf.nf_log_dir_header)
501 if (!net_eq(net, &init_net))
504 unregister_net_sysctl_table(nf_log_sysctl_fhdr);
510 static void netfilter_log_sysctl_exit(struct net *net)
512 struct ctl_table *table;
514 table = net->nf.nf_log_dir_header->ctl_table_arg;
515 unregister_net_sysctl_table(net->nf.nf_log_dir_header);
516 if (!net_eq(net, &init_net))
519 unregister_net_sysctl_table(nf_log_sysctl_fhdr);
522 static int netfilter_log_sysctl_init(struct net *net)
527 static void netfilter_log_sysctl_exit(struct net *net)
530 #endif /* CONFIG_SYSCTL */
532 static int __net_init nf_log_net_init(struct net *net)
536 #ifdef CONFIG_PROC_FS
537 if (!proc_create_net("nf_log", 0444, net->nf.proc_netfilter,
538 &nflog_seq_ops, sizeof(struct seq_net_private)))
541 ret = netfilter_log_sysctl_init(net);
548 #ifdef CONFIG_PROC_FS
549 remove_proc_entry("nf_log", net->nf.proc_netfilter);
554 static void __net_exit nf_log_net_exit(struct net *net)
556 netfilter_log_sysctl_exit(net);
557 #ifdef CONFIG_PROC_FS
558 remove_proc_entry("nf_log", net->nf.proc_netfilter);
562 static struct pernet_operations nf_log_net_ops = {
563 .init = nf_log_net_init,
564 .exit = nf_log_net_exit,
567 int __init netfilter_log_init(void)
569 return register_pernet_subsys(&nf_log_net_ops);