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#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
if (!proc_create("nf_log", S_IRUGO,
proc_net_netfilter, &nflog_file_ops))
return -1;
#endif
return 0;
}
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