1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/skbuff.h>
#include <linux/netfilter.h>
#include <linux/seq_file.h>
#include <net/protocol.h>
#include <net/netfilter/nf_log.h>
#include "nf_internals.h"
/* Internal logging interface, which relies on the real
LOG target modules */
#define NF_LOG_PREFIXLEN 128
static const struct nf_logger *nf_loggers[NPROTO] __read_mostly;
static DEFINE_MUTEX(nf_log_mutex);
/* return EBUSY if somebody else is registered, EEXIST if the same logger
* is registred, 0 on success. */
int nf_log_register(int pf, const struct nf_logger *logger)
{
int ret;
if (pf >= NPROTO)
return -EINVAL;
/* Any setup of logging members must be done before
* substituting pointer. */
ret = mutex_lock_interruptible(&nf_log_mutex);
if (ret < 0)
return ret;
if (!nf_loggers[pf])
rcu_assign_pointer(nf_loggers[pf], logger);
else if (nf_loggers[pf] == logger)
ret = -EEXIST;
else
ret = -EBUSY;
mutex_unlock(&nf_log_mutex);
return ret;
}
EXPORT_SYMBOL(nf_log_register);
void nf_log_unregister_pf(int pf)
{
if (pf >= NPROTO)
return;
mutex_lock(&nf_log_mutex);
rcu_assign_pointer(nf_loggers[pf], NULL);
mutex_unlock(&nf_log_mutex);
/* Give time to concurrent readers. */
synchronize_rcu();
}
EXPORT_SYMBOL(nf_log_unregister_pf);
void nf_log_unregister(const struct nf_logger *logger)
{
int i;
mutex_lock(&nf_log_mutex);
for (i = 0; i < NPROTO; i++) {
if (nf_loggers[i] == logger)
rcu_assign_pointer(nf_loggers[i], NULL);
}
mutex_unlock(&nf_log_mutex);
synchronize_rcu();
}
EXPORT_SYMBOL(nf_log_unregister);
void nf_log_packet(int pf,
unsigned int hooknum,
const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const struct nf_loginfo *loginfo,
const char *fmt, ...)
{
va_list args;
char prefix[NF_LOG_PREFIXLEN];
const struct nf_logger *logger;
rcu_read_lock();
logger = rcu_dereference(nf_loggers[pf]);
if (logger) {
va_start(args, fmt);
vsnprintf(prefix, sizeof(prefix), fmt, args);
va_end(args);
logger->logfn(pf, hooknum, skb, in, out, loginfo, prefix);
} else if (net_ratelimit()) {
printk(KERN_WARNING "nf_log_packet: can\'t log since "
"no backend logging module loaded in! Please either "
"load one, or disable logging explicitly\n");
}
rcu_read_unlock();
}
EXPORT_SYMBOL(nf_log_packet);
#ifdef CONFIG_PROC_FS
static void *seq_start(struct seq_file *seq, loff_t *pos)
__acquires(RCU)
{
rcu_read_lock();
if (*pos >= NPROTO)
return NULL;
return pos;
}
static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
{
(*pos)++;
if (*pos >= NPROTO)
return NULL;
return pos;
}
static void seq_stop(struct seq_file *s, void *v)
__releases(RCU)
{
rcu_read_unlock();
}
static int seq_show(struct seq_file *s, void *v)
{
loff_t *pos = v;
const struct nf_logger *logger;
logger = rcu_dereference(nf_loggers[*pos]);
if (!logger)
return seq_printf(s, "%2lld NONE\n", *pos);
return seq_printf(s, "%2lld %s\n", *pos, logger->name);
}
static const struct seq_operations nflog_seq_ops = {
.start = seq_start,
.next = seq_next,
.stop = seq_stop,
.show = seq_show,
};
static int nflog_open(struct inode *inode, struct file *file)
{
return seq_open(file, &nflog_seq_ops);
}
static const struct file_operations nflog_file_ops = {
.owner = THIS_MODULE,
.open = nflog_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
#endif /* PROC_FS */
int __init netfilter_log_init(void)
{
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *pde;
pde = create_proc_entry("nf_log", S_IRUGO, proc_net_netfilter);
if (!pde)
return -1;
pde->proc_fops = &nflog_file_ops;
#endif
return 0;
}
|
