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