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 NF_LOG_PREFIXLEN 128
17#define NFLOGGER_NAME_LEN 64
18
19static struct list_head nf_loggers_l[NFPROTO_NUMPROTO] __read_mostly;
20static DEFINE_MUTEX(nf_log_mutex);
21
22static struct nf_logger *__find_logger(int pf, const char *str_logger)
23{
24 struct nf_logger *t;
25
26 list_for_each_entry(t, &nf_loggers_l[pf], list[pf]) {
27 if (!strnicmp(str_logger, t->name, strlen(t->name)))
28 return t;
29 }
30
31 return NULL;
32}
33
34void nf_log_set(struct net *net, u_int8_t pf, const struct nf_logger *logger)
35{
36 const struct nf_logger *log;
37
38 if (pf == NFPROTO_UNSPEC)
39 return;
40
41 mutex_lock(&nf_log_mutex);
42 log = rcu_dereference_protected(net->nf.nf_loggers[pf],
43 lockdep_is_held(&nf_log_mutex));
44 if (log == NULL)
45 rcu_assign_pointer(net->nf.nf_loggers[pf], logger);
46
47 mutex_unlock(&nf_log_mutex);
48}
49EXPORT_SYMBOL(nf_log_set);
50
51void nf_log_unset(struct net *net, const struct nf_logger *logger)
52{
53 int i;
54 const struct nf_logger *log;
55
56 mutex_lock(&nf_log_mutex);
57 for (i = 0; i < NFPROTO_NUMPROTO; i++) {
58 log = rcu_dereference_protected(net->nf.nf_loggers[i],
59 lockdep_is_held(&nf_log_mutex));
60 if (log == logger)
61 RCU_INIT_POINTER(net->nf.nf_loggers[i], NULL);
62 }
63 mutex_unlock(&nf_log_mutex);
64 synchronize_rcu();
65}
66EXPORT_SYMBOL(nf_log_unset);
67
68
69int nf_log_register(u_int8_t pf, struct nf_logger *logger)
70{
71 int i;
72
73 if (pf >= ARRAY_SIZE(init_net.nf.nf_loggers))
74 return -EINVAL;
75
76 for (i = 0; i < ARRAY_SIZE(logger->list); i++)
77 INIT_LIST_HEAD(&logger->list[i]);
78
79 mutex_lock(&nf_log_mutex);
80
81 if (pf == NFPROTO_UNSPEC) {
82 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
83 list_add_tail(&(logger->list[i]), &(nf_loggers_l[i]));
84 } else {
85
86 list_add_tail(&logger->list[pf], &nf_loggers_l[pf]);
87 }
88
89 mutex_unlock(&nf_log_mutex);
90
91 return 0;
92}
93EXPORT_SYMBOL(nf_log_register);
94
95void nf_log_unregister(struct nf_logger *logger)
96{
97 int i;
98
99 mutex_lock(&nf_log_mutex);
100 for (i = 0; i < NFPROTO_NUMPROTO; i++)
101 list_del(&logger->list[i]);
102 mutex_unlock(&nf_log_mutex);
103}
104EXPORT_SYMBOL(nf_log_unregister);
105
106int nf_log_bind_pf(struct net *net, u_int8_t pf,
107 const struct nf_logger *logger)
108{
109 if (pf >= ARRAY_SIZE(net->nf.nf_loggers))
110 return -EINVAL;
111 mutex_lock(&nf_log_mutex);
112 if (__find_logger(pf, logger->name) == NULL) {
113 mutex_unlock(&nf_log_mutex);
114 return -ENOENT;
115 }
116 rcu_assign_pointer(net->nf.nf_loggers[pf], logger);
117 mutex_unlock(&nf_log_mutex);
118 return 0;
119}
120EXPORT_SYMBOL(nf_log_bind_pf);
121
122void nf_log_unbind_pf(struct net *net, u_int8_t pf)
123{
124 if (pf >= ARRAY_SIZE(net->nf.nf_loggers))
125 return;
126 mutex_lock(&nf_log_mutex);
127 RCU_INIT_POINTER(net->nf.nf_loggers[pf], NULL);
128 mutex_unlock(&nf_log_mutex);
129}
130EXPORT_SYMBOL(nf_log_unbind_pf);
131
132void nf_log_packet(struct net *net,
133 u_int8_t pf,
134 unsigned int hooknum,
135 const struct sk_buff *skb,
136 const struct net_device *in,
137 const struct net_device *out,
138 const struct nf_loginfo *loginfo,
139 const char *fmt, ...)
140{
141 va_list args;
142 char prefix[NF_LOG_PREFIXLEN];
143 const struct nf_logger *logger;
144
145 rcu_read_lock();
146 logger = rcu_dereference(net->nf.nf_loggers[pf]);
147 if (logger) {
148 va_start(args, fmt);
149 vsnprintf(prefix, sizeof(prefix), fmt, args);
150 va_end(args);
151 logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
152 }
153 rcu_read_unlock();
154}
155EXPORT_SYMBOL(nf_log_packet);
156
157#ifdef CONFIG_PROC_FS
158static void *seq_start(struct seq_file *seq, loff_t *pos)
159{
160 struct net *net = seq_file_net(seq);
161
162 mutex_lock(&nf_log_mutex);
163
164 if (*pos >= ARRAY_SIZE(net->nf.nf_loggers))
165 return NULL;
166
167 return pos;
168}
169
170static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
171{
172 struct net *net = seq_file_net(s);
173
174 (*pos)++;
175
176 if (*pos >= ARRAY_SIZE(net->nf.nf_loggers))
177 return NULL;
178
179 return pos;
180}
181
182static void seq_stop(struct seq_file *s, void *v)
183{
184 mutex_unlock(&nf_log_mutex);
185}
186
187static int seq_show(struct seq_file *s, void *v)
188{
189 loff_t *pos = v;
190 const struct nf_logger *logger;
191 struct nf_logger *t;
192 int ret;
193 struct net *net = seq_file_net(s);
194
195 logger = rcu_dereference_protected(net->nf.nf_loggers[*pos],
196 lockdep_is_held(&nf_log_mutex));
197
198 if (!logger)
199 ret = seq_printf(s, "%2lld NONE (", *pos);
200 else
201 ret = seq_printf(s, "%2lld %s (", *pos, logger->name);
202
203 if (ret < 0)
204 return ret;
205
206 list_for_each_entry(t, &nf_loggers_l[*pos], list[*pos]) {
207 ret = seq_printf(s, "%s", t->name);
208 if (ret < 0)
209 return ret;
210 if (&t->list[*pos] != nf_loggers_l[*pos].prev) {
211 ret = seq_printf(s, ",");
212 if (ret < 0)
213 return ret;
214 }
215 }
216
217 return seq_printf(s, ")\n");
218}
219
220static const struct seq_operations nflog_seq_ops = {
221 .start = seq_start,
222 .next = seq_next,
223 .stop = seq_stop,
224 .show = seq_show,
225};
226
227static int nflog_open(struct inode *inode, struct file *file)
228{
229 return seq_open_net(inode, file, &nflog_seq_ops,
230 sizeof(struct seq_net_private));
231}
232
233static const struct file_operations nflog_file_ops = {
234 .owner = THIS_MODULE,
235 .open = nflog_open,
236 .read = seq_read,
237 .llseek = seq_lseek,
238 .release = seq_release_net,
239};
240
241
242#endif
243
244#ifdef CONFIG_SYSCTL
245static char nf_log_sysctl_fnames[NFPROTO_NUMPROTO-NFPROTO_UNSPEC][3];
246static struct ctl_table nf_log_sysctl_table[NFPROTO_NUMPROTO+1];
247
248static int nf_log_proc_dostring(ctl_table *table, int write,
249 void __user *buffer, size_t *lenp, loff_t *ppos)
250{
251 const struct nf_logger *logger;
252 char buf[NFLOGGER_NAME_LEN];
253 size_t size = *lenp;
254 int r = 0;
255 int tindex = (unsigned long)table->extra1;
256 struct net *net = current->nsproxy->net_ns;
257
258 if (write) {
259 if (size > sizeof(buf))
260 size = sizeof(buf);
261 if (copy_from_user(buf, buffer, size))
262 return -EFAULT;
263
264 if (!strcmp(buf, "NONE")) {
265 nf_log_unbind_pf(net, tindex);
266 return 0;
267 }
268 mutex_lock(&nf_log_mutex);
269 logger = __find_logger(tindex, buf);
270 if (logger == NULL) {
271 mutex_unlock(&nf_log_mutex);
272 return -ENOENT;
273 }
274 rcu_assign_pointer(net->nf.nf_loggers[tindex], logger);
275 mutex_unlock(&nf_log_mutex);
276 } else {
277 mutex_lock(&nf_log_mutex);
278 logger = rcu_dereference_protected(net->nf.nf_loggers[tindex],
279 lockdep_is_held(&nf_log_mutex));
280 if (!logger)
281 table->data = "NONE";
282 else
283 table->data = logger->name;
284 r = proc_dostring(table, write, buffer, lenp, ppos);
285 mutex_unlock(&nf_log_mutex);
286 }
287
288 return r;
289}
290
291static int netfilter_log_sysctl_init(struct net *net)
292{
293 int i;
294 struct ctl_table *table;
295
296 table = nf_log_sysctl_table;
297 if (!net_eq(net, &init_net)) {
298 table = kmemdup(nf_log_sysctl_table,
299 sizeof(nf_log_sysctl_table),
300 GFP_KERNEL);
301 if (!table)
302 goto err_alloc;
303 } else {
304 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
305 snprintf(nf_log_sysctl_fnames[i],
306 3, "%d", i);
307 nf_log_sysctl_table[i].procname =
308 nf_log_sysctl_fnames[i];
309 nf_log_sysctl_table[i].data = NULL;
310 nf_log_sysctl_table[i].maxlen =
311 NFLOGGER_NAME_LEN * sizeof(char);
312 nf_log_sysctl_table[i].mode = 0644;
313 nf_log_sysctl_table[i].proc_handler =
314 nf_log_proc_dostring;
315 nf_log_sysctl_table[i].extra1 =
316 (void *)(unsigned long) i;
317 }
318 }
319
320 net->nf.nf_log_dir_header = register_net_sysctl(net,
321 "net/netfilter/nf_log",
322 table);
323 if (!net->nf.nf_log_dir_header)
324 goto err_reg;
325
326 return 0;
327
328err_reg:
329 if (!net_eq(net, &init_net))
330 kfree(table);
331err_alloc:
332 return -ENOMEM;
333}
334
335static void netfilter_log_sysctl_exit(struct net *net)
336{
337 struct ctl_table *table;
338
339 table = net->nf.nf_log_dir_header->ctl_table_arg;
340 unregister_net_sysctl_table(net->nf.nf_log_dir_header);
341 if (!net_eq(net, &init_net))
342 kfree(table);
343}
344#else
345static int netfilter_log_sysctl_init(struct net *net)
346{
347 return 0;
348}
349
350static void netfilter_log_sysctl_exit(struct net *net)
351{
352}
353#endif
354
355static int __net_init nf_log_net_init(struct net *net)
356{
357 int ret = -ENOMEM;
358
359#ifdef CONFIG_PROC_FS
360 if (!proc_create("nf_log", S_IRUGO,
361 net->nf.proc_netfilter, &nflog_file_ops))
362 return ret;
363#endif
364 ret = netfilter_log_sysctl_init(net);
365 if (ret < 0)
366 goto out_sysctl;
367
368 return 0;
369
370out_sysctl:
371#ifdef CONFIG_PROC_FS
372
373 if (!net_eq(net, &init_net))
374 remove_proc_entry("nf_log", net->nf.proc_netfilter);
375#endif
376 return ret;
377}
378
379static void __net_exit nf_log_net_exit(struct net *net)
380{
381 netfilter_log_sysctl_exit(net);
382#ifdef CONFIG_PROC_FS
383 remove_proc_entry("nf_log", net->nf.proc_netfilter);
384#endif
385}
386
387static struct pernet_operations nf_log_net_ops = {
388 .init = nf_log_net_init,
389 .exit = nf_log_net_exit,
390};
391
392int __init netfilter_log_init(void)
393{
394 int i, ret;
395
396 ret = register_pernet_subsys(&nf_log_net_ops);
397 if (ret < 0)
398 return ret;
399
400 for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
401 INIT_LIST_HEAD(&(nf_loggers_l[i]));
402
403 return 0;
404}
405
