blob: ce0c406f58a8b645cc4500c85dfad2008d0db70d [file] [log] [blame]
#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
#define NFLOGGER_NAME_LEN 64
static const struct nf_logger __rcu *nf_loggers[NFPROTO_NUMPROTO] __read_mostly;
static struct list_head nf_loggers_l[NFPROTO_NUMPROTO] __read_mostly;
static DEFINE_MUTEX(nf_log_mutex);
static struct nf_logger *__find_logger(int pf, const char *str_logger)
{
struct nf_logger *t;
list_for_each_entry(t, &nf_loggers_l[pf], list[pf]) {
if (!strnicmp(str_logger, t->name, strlen(t->name)))
return t;
}
return NULL;
}
/* return EEXIST if the same logger is registred, 0 on success. */
int nf_log_register(u_int8_t pf, struct nf_logger *logger)
{
const struct nf_logger *llog;
int i;
if (pf >= ARRAY_SIZE(nf_loggers))
return -EINVAL;
for (i = 0; i < ARRAY_SIZE(logger->list); i++)
INIT_LIST_HEAD(&logger->list[i]);
mutex_lock(&nf_log_mutex);
if (pf == NFPROTO_UNSPEC) {
for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
list_add_tail(&(logger->list[i]), &(nf_loggers_l[i]));
} else {
/* register at end of list to honor first register win */
list_add_tail(&logger->list[pf], &nf_loggers_l[pf]);
llog = rcu_dereference_protected(nf_loggers[pf],
lockdep_is_held(&nf_log_mutex));
if (llog == NULL)
RCU_INIT_POINTER(nf_loggers[pf], logger);
}
mutex_unlock(&nf_log_mutex);
return 0;
}
EXPORT_SYMBOL(nf_log_register);
void nf_log_unregister(struct nf_logger *logger)
{
const struct nf_logger *c_logger;
int i;
mutex_lock(&nf_log_mutex);
for (i = 0; i < ARRAY_SIZE(nf_loggers); i++) {
c_logger = rcu_dereference_protected(nf_loggers[i],
lockdep_is_held(&nf_log_mutex));
if (c_logger == logger)
RCU_INIT_POINTER(nf_loggers[i], NULL);
list_del(&logger->list[i]);
}
mutex_unlock(&nf_log_mutex);
synchronize_rcu();
}
EXPORT_SYMBOL(nf_log_unregister);
int nf_log_bind_pf(u_int8_t pf, const struct nf_logger *logger)
{
if (pf >= ARRAY_SIZE(nf_loggers))
return -EINVAL;
mutex_lock(&nf_log_mutex);
if (__find_logger(pf, logger->name) == NULL) {
mutex_unlock(&nf_log_mutex);
return -ENOENT;
}
RCU_INIT_POINTER(nf_loggers[pf], logger);
mutex_unlock(&nf_log_mutex);
return 0;
}
EXPORT_SYMBOL(nf_log_bind_pf);
void nf_log_unbind_pf(u_int8_t pf)
{
if (pf >= ARRAY_SIZE(nf_loggers))
return;
mutex_lock(&nf_log_mutex);
RCU_INIT_POINTER(nf_loggers[pf], NULL);
mutex_unlock(&nf_log_mutex);
}
EXPORT_SYMBOL(nf_log_unbind_pf);
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)
{
mutex_lock(&nf_log_mutex);
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)
{
mutex_unlock(&nf_log_mutex);
}
static int seq_show(struct seq_file *s, void *v)
{
loff_t *pos = v;
const struct nf_logger *logger;
struct nf_logger *t;
int ret;
logger = rcu_dereference_protected(nf_loggers[*pos],
lockdep_is_held(&nf_log_mutex));
if (!logger)
ret = seq_printf(s, "%2lld NONE (", *pos);
else
ret = seq_printf(s, "%2lld %s (", *pos, logger->name);
if (ret < 0)
return ret;
list_for_each_entry(t, &nf_loggers_l[*pos], list[*pos]) {
ret = seq_printf(s, "%s", t->name);
if (ret < 0)
return ret;
if (&t->list[*pos] != nf_loggers_l[*pos].prev) {
ret = seq_printf(s, ",");
if (ret < 0)
return ret;
}
}
return seq_printf(s, ")\n");
}
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 */
#ifdef CONFIG_SYSCTL
static struct ctl_path nf_log_sysctl_path[] = {
{ .procname = "net", },
{ .procname = "netfilter", },
{ .procname = "nf_log", },
{ }
};
static char nf_log_sysctl_fnames[NFPROTO_NUMPROTO-NFPROTO_UNSPEC][3];
static struct ctl_table nf_log_sysctl_table[NFPROTO_NUMPROTO+1];
static struct ctl_table_header *nf_log_dir_header;
static int nf_log_proc_dostring(ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
const struct nf_logger *logger;
char buf[NFLOGGER_NAME_LEN];
size_t size = *lenp;
int r = 0;
int tindex = (unsigned long)table->extra1;
if (write) {
if (size > sizeof(buf))
size = sizeof(buf);
if (copy_from_user(buf, buffer, size))
return -EFAULT;
if (!strcmp(buf, "NONE")) {
nf_log_unbind_pf(tindex);
return 0;
}
mutex_lock(&nf_log_mutex);
logger = __find_logger(tindex, buf);
if (logger == NULL) {
mutex_unlock(&nf_log_mutex);
return -ENOENT;
}
RCU_INIT_POINTER(nf_loggers[tindex], logger);
mutex_unlock(&nf_log_mutex);
} else {
mutex_lock(&nf_log_mutex);
logger = rcu_dereference_protected(nf_loggers[tindex],
lockdep_is_held(&nf_log_mutex));
if (!logger)
table->data = "NONE";
else
table->data = logger->name;
r = proc_dostring(table, write, buffer, lenp, ppos);
mutex_unlock(&nf_log_mutex);
}
return r;
}
static __init int netfilter_log_sysctl_init(void)
{
int i;
for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
snprintf(nf_log_sysctl_fnames[i-NFPROTO_UNSPEC], 3, "%d", i);
nf_log_sysctl_table[i].procname =
nf_log_sysctl_fnames[i-NFPROTO_UNSPEC];
nf_log_sysctl_table[i].data = NULL;
nf_log_sysctl_table[i].maxlen =
NFLOGGER_NAME_LEN * sizeof(char);
nf_log_sysctl_table[i].mode = 0644;
nf_log_sysctl_table[i].proc_handler = nf_log_proc_dostring;
nf_log_sysctl_table[i].extra1 = (void *)(unsigned long) i;
}
nf_log_dir_header = register_sysctl_paths(nf_log_sysctl_path,
nf_log_sysctl_table);
if (!nf_log_dir_header)
return -ENOMEM;
return 0;
}
#else
static __init int netfilter_log_sysctl_init(void)
{
return 0;
}
#endif /* CONFIG_SYSCTL */
int __init netfilter_log_init(void)
{
int i, r;
#ifdef CONFIG_PROC_FS
if (!proc_create("nf_log", S_IRUGO,
proc_net_netfilter, &nflog_file_ops))
return -1;
#endif
/* Errors will trigger panic, unroll on error is unnecessary. */
r = netfilter_log_sysctl_init();
if (r < 0)
return r;
for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
INIT_LIST_HEAD(&(nf_loggers_l[i]));
return 0;
}