// SPDX-License-Identifier: GPL-2.0-only
|
#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 NFLOGGER_NAME_LEN 64
|
|
int sysctl_nf_log_all_netns __read_mostly;
|
EXPORT_SYMBOL(sysctl_nf_log_all_netns);
|
|
static struct nf_logger __rcu *loggers[NFPROTO_NUMPROTO][NF_LOG_TYPE_MAX] __read_mostly;
|
static DEFINE_MUTEX(nf_log_mutex);
|
|
#define nft_log_dereference(logger) \
|
rcu_dereference_protected(logger, lockdep_is_held(&nf_log_mutex))
|
|
static struct nf_logger *__find_logger(int pf, const char *str_logger)
|
{
|
struct nf_logger *log;
|
int i;
|
|
for (i = 0; i < NF_LOG_TYPE_MAX; i++) {
|
if (loggers[pf][i] == NULL)
|
continue;
|
|
log = nft_log_dereference(loggers[pf][i]);
|
if (!strncasecmp(str_logger, log->name, strlen(log->name)))
|
return log;
|
}
|
|
return NULL;
|
}
|
|
int nf_log_set(struct net *net, u_int8_t pf, const struct nf_logger *logger)
|
{
|
const struct nf_logger *log;
|
|
if (pf == NFPROTO_UNSPEC || pf >= ARRAY_SIZE(net->nf.nf_loggers))
|
return -EOPNOTSUPP;
|
|
mutex_lock(&nf_log_mutex);
|
log = nft_log_dereference(net->nf.nf_loggers[pf]);
|
if (log == NULL)
|
rcu_assign_pointer(net->nf.nf_loggers[pf], logger);
|
|
mutex_unlock(&nf_log_mutex);
|
|
return 0;
|
}
|
EXPORT_SYMBOL(nf_log_set);
|
|
void nf_log_unset(struct net *net, const struct nf_logger *logger)
|
{
|
int i;
|
const struct nf_logger *log;
|
|
mutex_lock(&nf_log_mutex);
|
for (i = 0; i < NFPROTO_NUMPROTO; i++) {
|
log = nft_log_dereference(net->nf.nf_loggers[i]);
|
if (log == logger)
|
RCU_INIT_POINTER(net->nf.nf_loggers[i], NULL);
|
}
|
mutex_unlock(&nf_log_mutex);
|
}
|
EXPORT_SYMBOL(nf_log_unset);
|
|
/* return EEXIST if the same logger is registered, 0 on success. */
|
int nf_log_register(u_int8_t pf, struct nf_logger *logger)
|
{
|
int i;
|
int ret = 0;
|
|
if (pf >= ARRAY_SIZE(init_net.nf.nf_loggers))
|
return -EINVAL;
|
|
mutex_lock(&nf_log_mutex);
|
|
if (pf == NFPROTO_UNSPEC) {
|
for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
|
if (rcu_access_pointer(loggers[i][logger->type])) {
|
ret = -EEXIST;
|
goto unlock;
|
}
|
}
|
for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
|
rcu_assign_pointer(loggers[i][logger->type], logger);
|
} else {
|
if (rcu_access_pointer(loggers[pf][logger->type])) {
|
ret = -EEXIST;
|
goto unlock;
|
}
|
rcu_assign_pointer(loggers[pf][logger->type], logger);
|
}
|
|
unlock:
|
mutex_unlock(&nf_log_mutex);
|
return ret;
|
}
|
EXPORT_SYMBOL(nf_log_register);
|
|
void nf_log_unregister(struct nf_logger *logger)
|
{
|
const struct nf_logger *log;
|
int i;
|
|
mutex_lock(&nf_log_mutex);
|
for (i = 0; i < NFPROTO_NUMPROTO; i++) {
|
log = nft_log_dereference(loggers[i][logger->type]);
|
if (log == logger)
|
RCU_INIT_POINTER(loggers[i][logger->type], NULL);
|
}
|
mutex_unlock(&nf_log_mutex);
|
synchronize_rcu();
|
}
|
EXPORT_SYMBOL(nf_log_unregister);
|
|
int nf_log_bind_pf(struct net *net, u_int8_t pf,
|
const struct nf_logger *logger)
|
{
|
if (pf >= ARRAY_SIZE(net->nf.nf_loggers))
|
return -EINVAL;
|
mutex_lock(&nf_log_mutex);
|
if (__find_logger(pf, logger->name) == NULL) {
|
mutex_unlock(&nf_log_mutex);
|
return -ENOENT;
|
}
|
rcu_assign_pointer(net->nf.nf_loggers[pf], logger);
|
mutex_unlock(&nf_log_mutex);
|
return 0;
|
}
|
EXPORT_SYMBOL(nf_log_bind_pf);
|
|
void nf_log_unbind_pf(struct net *net, u_int8_t pf)
|
{
|
if (pf >= ARRAY_SIZE(net->nf.nf_loggers))
|
return;
|
mutex_lock(&nf_log_mutex);
|
RCU_INIT_POINTER(net->nf.nf_loggers[pf], NULL);
|
mutex_unlock(&nf_log_mutex);
|
}
|
EXPORT_SYMBOL(nf_log_unbind_pf);
|
|
void nf_logger_request_module(int pf, enum nf_log_type type)
|
{
|
if (loggers[pf][type] == NULL)
|
request_module("nf-logger-%u-%u", pf, type);
|
}
|
EXPORT_SYMBOL_GPL(nf_logger_request_module);
|
|
int nf_logger_find_get(int pf, enum nf_log_type type)
|
{
|
struct nf_logger *logger;
|
int ret = -ENOENT;
|
|
if (pf == NFPROTO_INET) {
|
ret = nf_logger_find_get(NFPROTO_IPV4, type);
|
if (ret < 0)
|
return ret;
|
|
ret = nf_logger_find_get(NFPROTO_IPV6, type);
|
if (ret < 0) {
|
nf_logger_put(NFPROTO_IPV4, type);
|
return ret;
|
}
|
|
return 0;
|
}
|
|
if (rcu_access_pointer(loggers[pf][type]) == NULL)
|
request_module("nf-logger-%u-%u", pf, type);
|
|
rcu_read_lock();
|
logger = rcu_dereference(loggers[pf][type]);
|
if (logger == NULL)
|
goto out;
|
|
if (try_module_get(logger->me))
|
ret = 0;
|
out:
|
rcu_read_unlock();
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(nf_logger_find_get);
|
|
void nf_logger_put(int pf, enum nf_log_type type)
|
{
|
struct nf_logger *logger;
|
|
if (pf == NFPROTO_INET) {
|
nf_logger_put(NFPROTO_IPV4, type);
|
nf_logger_put(NFPROTO_IPV6, type);
|
return;
|
}
|
|
BUG_ON(loggers[pf][type] == NULL);
|
|
rcu_read_lock();
|
logger = rcu_dereference(loggers[pf][type]);
|
module_put(logger->me);
|
rcu_read_unlock();
|
}
|
EXPORT_SYMBOL_GPL(nf_logger_put);
|
|
void nf_log_packet(struct net *net,
|
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();
|
if (loginfo != NULL)
|
logger = rcu_dereference(loggers[pf][loginfo->type]);
|
else
|
logger = rcu_dereference(net->nf.nf_loggers[pf]);
|
|
if (logger) {
|
va_start(args, fmt);
|
vsnprintf(prefix, sizeof(prefix), fmt, args);
|
va_end(args);
|
logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
|
}
|
rcu_read_unlock();
|
}
|
EXPORT_SYMBOL(nf_log_packet);
|
|
void nf_log_trace(struct net *net,
|
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(net->nf.nf_loggers[pf]);
|
if (logger) {
|
va_start(args, fmt);
|
vsnprintf(prefix, sizeof(prefix), fmt, args);
|
va_end(args);
|
logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
|
}
|
rcu_read_unlock();
|
}
|
EXPORT_SYMBOL(nf_log_trace);
|
|
#define S_SIZE (1024 - (sizeof(unsigned int) + 1))
|
|
struct nf_log_buf {
|
unsigned int count;
|
char buf[S_SIZE + 1];
|
};
|
static struct nf_log_buf emergency, *emergency_ptr = &emergency;
|
|
__printf(2, 3) int nf_log_buf_add(struct nf_log_buf *m, const char *f, ...)
|
{
|
va_list args;
|
int len;
|
|
if (likely(m->count < S_SIZE)) {
|
va_start(args, f);
|
len = vsnprintf(m->buf + m->count, S_SIZE - m->count, f, args);
|
va_end(args);
|
if (likely(m->count + len < S_SIZE)) {
|
m->count += len;
|
return 0;
|
}
|
}
|
m->count = S_SIZE;
|
printk_once(KERN_ERR KBUILD_MODNAME " please increase S_SIZE\n");
|
return -1;
|
}
|
EXPORT_SYMBOL_GPL(nf_log_buf_add);
|
|
struct nf_log_buf *nf_log_buf_open(void)
|
{
|
struct nf_log_buf *m = kmalloc(sizeof(*m), GFP_ATOMIC);
|
|
if (unlikely(!m)) {
|
local_bh_disable();
|
do {
|
m = xchg(&emergency_ptr, NULL);
|
} while (!m);
|
}
|
m->count = 0;
|
return m;
|
}
|
EXPORT_SYMBOL_GPL(nf_log_buf_open);
|
|
void nf_log_buf_close(struct nf_log_buf *m)
|
{
|
m->buf[m->count] = 0;
|
printk("%s\n", m->buf);
|
|
if (likely(m != &emergency))
|
kfree(m);
|
else {
|
emergency_ptr = m;
|
local_bh_enable();
|
}
|
}
|
EXPORT_SYMBOL_GPL(nf_log_buf_close);
|
|
#ifdef CONFIG_PROC_FS
|
static void *seq_start(struct seq_file *seq, loff_t *pos)
|
{
|
struct net *net = seq_file_net(seq);
|
|
mutex_lock(&nf_log_mutex);
|
|
if (*pos >= ARRAY_SIZE(net->nf.nf_loggers))
|
return NULL;
|
|
return pos;
|
}
|
|
static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
|
{
|
struct net *net = seq_file_net(s);
|
|
(*pos)++;
|
|
if (*pos >= ARRAY_SIZE(net->nf.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;
|
int i;
|
struct net *net = seq_file_net(s);
|
|
logger = nft_log_dereference(net->nf.nf_loggers[*pos]);
|
|
if (!logger)
|
seq_printf(s, "%2lld NONE (", *pos);
|
else
|
seq_printf(s, "%2lld %s (", *pos, logger->name);
|
|
if (seq_has_overflowed(s))
|
return -ENOSPC;
|
|
for (i = 0; i < NF_LOG_TYPE_MAX; i++) {
|
if (loggers[*pos][i] == NULL)
|
continue;
|
|
logger = nft_log_dereference(loggers[*pos][i]);
|
seq_puts(s, logger->name);
|
if (i == 0 && loggers[*pos][i + 1] != NULL)
|
seq_puts(s, ",");
|
|
if (seq_has_overflowed(s))
|
return -ENOSPC;
|
}
|
|
seq_puts(s, ")\n");
|
|
if (seq_has_overflowed(s))
|
return -ENOSPC;
|
return 0;
|
}
|
|
static const struct seq_operations nflog_seq_ops = {
|
.start = seq_start,
|
.next = seq_next,
|
.stop = seq_stop,
|
.show = seq_show,
|
};
|
#endif /* PROC_FS */
|
|
#ifdef CONFIG_SYSCTL
|
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_sysctl_fhdr;
|
|
static struct ctl_table nf_log_sysctl_ftable[] = {
|
{
|
.procname = "nf_log_all_netns",
|
.data = &sysctl_nf_log_all_netns,
|
.maxlen = sizeof(sysctl_nf_log_all_netns),
|
.mode = 0644,
|
.proc_handler = proc_dointvec,
|
},
|
{ }
|
};
|
|
static int nf_log_proc_dostring(struct ctl_table *table, int write,
|
void *buffer, size_t *lenp, loff_t *ppos)
|
{
|
const struct nf_logger *logger;
|
char buf[NFLOGGER_NAME_LEN];
|
int r = 0;
|
int tindex = (unsigned long)table->extra1;
|
struct net *net = table->extra2;
|
|
if (write) {
|
struct ctl_table tmp = *table;
|
|
/* proc_dostring() can append to existing strings, so we need to
|
* initialize it as an empty string.
|
*/
|
buf[0] = '\0';
|
tmp.data = buf;
|
r = proc_dostring(&tmp, write, buffer, lenp, ppos);
|
if (r)
|
return r;
|
|
if (!strcmp(buf, "NONE")) {
|
nf_log_unbind_pf(net, tindex);
|
return 0;
|
}
|
mutex_lock(&nf_log_mutex);
|
logger = __find_logger(tindex, buf);
|
if (logger == NULL) {
|
mutex_unlock(&nf_log_mutex);
|
return -ENOENT;
|
}
|
rcu_assign_pointer(net->nf.nf_loggers[tindex], logger);
|
mutex_unlock(&nf_log_mutex);
|
} else {
|
struct ctl_table tmp = *table;
|
|
tmp.data = buf;
|
mutex_lock(&nf_log_mutex);
|
logger = nft_log_dereference(net->nf.nf_loggers[tindex]);
|
if (!logger)
|
strlcpy(buf, "NONE", sizeof(buf));
|
else
|
strlcpy(buf, logger->name, sizeof(buf));
|
mutex_unlock(&nf_log_mutex);
|
r = proc_dostring(&tmp, write, buffer, lenp, ppos);
|
}
|
|
return r;
|
}
|
|
static int netfilter_log_sysctl_init(struct net *net)
|
{
|
int i;
|
struct ctl_table *table;
|
|
table = nf_log_sysctl_table;
|
if (!net_eq(net, &init_net)) {
|
table = kmemdup(nf_log_sysctl_table,
|
sizeof(nf_log_sysctl_table),
|
GFP_KERNEL);
|
if (!table)
|
goto err_alloc;
|
} else {
|
for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
|
snprintf(nf_log_sysctl_fnames[i],
|
3, "%d", i);
|
nf_log_sysctl_table[i].procname =
|
nf_log_sysctl_fnames[i];
|
nf_log_sysctl_table[i].maxlen = NFLOGGER_NAME_LEN;
|
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_sysctl_fhdr = register_net_sysctl(net, "net/netfilter",
|
nf_log_sysctl_ftable);
|
if (!nf_log_sysctl_fhdr)
|
goto err_freg;
|
}
|
|
for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
|
table[i].extra2 = net;
|
|
net->nf.nf_log_dir_header = register_net_sysctl(net,
|
"net/netfilter/nf_log",
|
table);
|
if (!net->nf.nf_log_dir_header)
|
goto err_reg;
|
|
return 0;
|
|
err_reg:
|
if (!net_eq(net, &init_net))
|
kfree(table);
|
else
|
unregister_net_sysctl_table(nf_log_sysctl_fhdr);
|
err_freg:
|
err_alloc:
|
return -ENOMEM;
|
}
|
|
static void netfilter_log_sysctl_exit(struct net *net)
|
{
|
struct ctl_table *table;
|
|
table = net->nf.nf_log_dir_header->ctl_table_arg;
|
unregister_net_sysctl_table(net->nf.nf_log_dir_header);
|
if (!net_eq(net, &init_net))
|
kfree(table);
|
else
|
unregister_net_sysctl_table(nf_log_sysctl_fhdr);
|
}
|
#else
|
static int netfilter_log_sysctl_init(struct net *net)
|
{
|
return 0;
|
}
|
|
static void netfilter_log_sysctl_exit(struct net *net)
|
{
|
}
|
#endif /* CONFIG_SYSCTL */
|
|
static int __net_init nf_log_net_init(struct net *net)
|
{
|
int ret = -ENOMEM;
|
|
#ifdef CONFIG_PROC_FS
|
if (!proc_create_net("nf_log", 0444, net->nf.proc_netfilter,
|
&nflog_seq_ops, sizeof(struct seq_net_private)))
|
return ret;
|
#endif
|
ret = netfilter_log_sysctl_init(net);
|
if (ret < 0)
|
goto out_sysctl;
|
|
return 0;
|
|
out_sysctl:
|
#ifdef CONFIG_PROC_FS
|
remove_proc_entry("nf_log", net->nf.proc_netfilter);
|
#endif
|
return ret;
|
}
|
|
static void __net_exit nf_log_net_exit(struct net *net)
|
{
|
netfilter_log_sysctl_exit(net);
|
#ifdef CONFIG_PROC_FS
|
remove_proc_entry("nf_log", net->nf.proc_netfilter);
|
#endif
|
}
|
|
static struct pernet_operations nf_log_net_ops = {
|
.init = nf_log_net_init,
|
.exit = nf_log_net_exit,
|
};
|
|
int __init netfilter_log_init(void)
|
{
|
return register_pernet_subsys(&nf_log_net_ops);
|
}
|
