mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 02:09:42 +00:00
![Jan Engelhardt](/assets/img/avatar_default.png)
The netfilter subsystem only supports a handful of protocols (much less than PF_*) and even non-PF protocols like ARP and pseudo-protocols like PF_BRIDGE. By creating NFPROTO_*, we can earn a few memory savings on arrays that previously were always PF_MAX-sized and keep the pseudo-protocols to ourselves. Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Patrick McHardy <kaber@trash.net>
172 lines
3.5 KiB
C
172 lines
3.5 KiB
C
#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[NFPROTO_NUMPROTO] __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(u_int8_t pf, const struct nf_logger *logger)
|
|
{
|
|
int ret;
|
|
|
|
if (pf >= ARRAY_SIZE(nf_loggers))
|
|
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(u_int8_t pf)
|
|
{
|
|
if (pf >= ARRAY_SIZE(nf_loggers))
|
|
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 < ARRAY_SIZE(nf_loggers); 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(u_int8_t 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);
|
|
}
|
|
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 >= ARRAY_SIZE(nf_loggers))
|
|
return NULL;
|
|
|
|
return pos;
|
|
}
|
|
|
|
static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
|
|
{
|
|
(*pos)++;
|
|
|
|
if (*pos >= ARRAY_SIZE(nf_loggers))
|
|
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;
|
|
}
|