[linux.git] / net / netfilter / nf_log.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
#define NFLOGGER_NAME_LEN		64

static const struct nf_logger *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) {
		int i;
		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(nf_loggers[pf]);
		if (llog == NULL)
			rcu_assign_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(nf_loggers[i]);
		if (c_logger == logger)
			rcu_assign_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)
{
	mutex_lock(&nf_log_mutex);
	if (__find_logger(pf, logger->name) == NULL) {
		mutex_unlock(&nf_log_mutex);
		return -ENOENT;
	}
	rcu_assign_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)
{
	mutex_lock(&nf_log_mutex);
	rcu_assign_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)
	__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;
	struct nf_logger *t;
	int ret;

	logger = rcu_dereference(nf_loggers[*pos]);

	if (!logger)
		ret = seq_printf(s, "%2lld NONE (", *pos);
	else
		ret = seq_printf(s, "%2lld %s (", *pos, logger->name);

	if (ret < 0)
		return ret;

	mutex_lock(&nf_log_mutex);
	list_for_each_entry(t, &nf_loggers_l[*pos], list[*pos]) {
		ret = seq_printf(s, "%s", t->name);
		if (ret < 0) {
			mutex_unlock(&nf_log_mutex);
			return ret;
		}
		if (&t->list[*pos] != nf_loggers_l[*pos].prev) {
			ret = seq_printf(s, ",");
			if (ret < 0) {
				mutex_unlock(&nf_log_mutex);
				return ret;
			}
		}
	}
	mutex_unlock(&nf_log_mutex);

	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
struct ctl_path nf_log_sysctl_path[] = {
	{ .procname = "net", .ctl_name = CTL_NET, },
	{ .procname = "netfilter", .ctl_name = NET_NETFILTER, },
	{ .procname = "nf_log", .ctl_name = CTL_UNNUMBERED, },
	{ }
};

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, struct file *filp,
			 void *buffer, size_t *lenp, loff_t *ppos)
{
	const struct nf_logger *logger;
	int r = 0;
	int tindex = (unsigned long)table->extra1;

	if (write) {
		if (!strcmp(buffer, "NONE")) {
			nf_log_unbind_pf(tindex);
			return 0;
		}
		mutex_lock(&nf_log_mutex);
		logger = __find_logger(tindex, buffer);
		if (logger == NULL) {
			mutex_unlock(&nf_log_mutex);
			return -ENOENT;
		}
		rcu_assign_pointer(nf_loggers[tindex], logger);
		mutex_unlock(&nf_log_mutex);
	} else {
		mutex_lock(&nf_log_mutex);
		logger = nf_loggers[tindex];
		if (!logger)
			table->data = "NONE";
		else
			table->data = logger->name;
		r = proc_dostring(table, write, filp, 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].ctl_name	= CTL_UNNUMBERED;
		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;
}
Commit	Line	Data
f6ebe77f HW	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>
bbd86b9f	7	#include <linux/seq_file.h>
f6ebe77f	8	#include <net/protocol.h>
f01ffbd6	9	#include <net/netfilter/nf_log.h>
f6ebe77f HW	10
	11	#include "nf_internals.h"
	12
a5d29264	13	/* Internal logging interface, which relies on the real
f6ebe77f HW	14	LOG target modules */
	15
	16	#define NF_LOG_PREFIXLEN 128
17625274	17	#define NFLOGGER_NAME_LEN 64
f6ebe77f	18
7e9c6eeb	19	static const struct nf_logger *nf_loggers[NFPROTO_NUMPROTO] __read_mostly;
ca735b3a	20	static struct list_head nf_loggers_l[NFPROTO_NUMPROTO] __read_mostly;
9b73534d	21	static DEFINE_MUTEX(nf_log_mutex);
f6ebe77f	22
ca735b3a	23	static struct nf_logger __find_logger(int pf, const char str_logger)
f6ebe77f	24	{
ca735b3a	25	struct nf_logger *t;
f6ebe77f	26
ca735b3a EL	27	list_for_each_entry(t, &nf_loggers_l[pf], list[pf]) {
	28	if (!strnicmp(str_logger, t->name, strlen(t->name)))
	29	return t;
	30	}
d72367b6	31
ca735b3a	32	return NULL;
601e68e1	33	}
f6ebe77f	34
ca735b3a EL	35	/* return EEXIST if the same logger is registred, 0 on success. */
ca735b3a EL	36	int nf_log_register(u_int8_t pf, struct nf_logger *logger)
f6ebe77f	37	{
ca735b3a	38	const struct nf_logger *llog;
b6f0a365	39	int i;
ca735b3a	40
7e9c6eeb	41	if (pf >= ARRAY_SIZE(nf_loggers))
ca735b3a EL	42	return -EINVAL;
ca735b3a EL	43
b6f0a365 ED	44	for (i = 0; i < ARRAY_SIZE(logger->list); i++)
	45	INIT_LIST_HEAD(&logger->list[i]);
	46
9b73534d	47	mutex_lock(&nf_log_mutex);
ca735b3a EL	48
	49	if (pf == NFPROTO_UNSPEC) {
	50	int i;
	51	for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
	52	list_add_tail(&(logger->list[i]), &(nf_loggers_l[i]));
	53	} else {
	54	/* register at end of list to honor first register win */
	55	list_add_tail(&logger->list[pf], &nf_loggers_l[pf]);
	56	llog = rcu_dereference(nf_loggers[pf]);
	57	if (llog == NULL)
	58	rcu_assign_pointer(nf_loggers[pf], logger);
	59	}
	60
9b73534d	61	mutex_unlock(&nf_log_mutex);
f6ebe77f	62
ca735b3a	63	return 0;
f6ebe77f	64	}
ca735b3a	65	EXPORT_SYMBOL(nf_log_register);
f6ebe77f	66
ca735b3a	67	void nf_log_unregister(struct nf_logger *logger)
f6ebe77f	68	{
ca735b3a	69	const struct nf_logger *c_logger;
f6ebe77f HW	70	int i;
f6ebe77f HW	71
9b73534d	72	mutex_lock(&nf_log_mutex);
7e9c6eeb	73	for (i = 0; i < ARRAY_SIZE(nf_loggers); i++) {
ca735b3a EL	74	c_logger = rcu_dereference(nf_loggers[i]);
ca735b3a EL	75	if (c_logger == logger)
e92ad99c	76	rcu_assign_pointer(nf_loggers[i], NULL);
ca735b3a	77	list_del(&logger->list[i]);
f6ebe77f	78	}
9b73534d	79	mutex_unlock(&nf_log_mutex);
f6ebe77f	80
a5ea6169	81	synchronize_rcu();
f6ebe77f	82	}
e92ad99c	83	EXPORT_SYMBOL(nf_log_unregister);
f6ebe77f	84
ca735b3a EL	85	int nf_log_bind_pf(u_int8_t pf, const struct nf_logger *logger)
	86	{
	87	mutex_lock(&nf_log_mutex);
	88	if (__find_logger(pf, logger->name) == NULL) {
	89	mutex_unlock(&nf_log_mutex);
	90	return -ENOENT;
	91	}
	92	rcu_assign_pointer(nf_loggers[pf], logger);
	93	mutex_unlock(&nf_log_mutex);
	94	return 0;
	95	}
	96	EXPORT_SYMBOL(nf_log_bind_pf);
	97
	98	void nf_log_unbind_pf(u_int8_t pf)
	99	{
	100	mutex_lock(&nf_log_mutex);
	101	rcu_assign_pointer(nf_loggers[pf], NULL);
	102	mutex_unlock(&nf_log_mutex);
	103	}
	104	EXPORT_SYMBOL(nf_log_unbind_pf);
	105
76108cea	106	void nf_log_packet(u_int8_t pf,
f6ebe77f HW	107	unsigned int hooknum,
	108	const struct sk_buff *skb,
	109	const struct net_device *in,
	110	const struct net_device *out,
7b2f9631	111	const struct nf_loginfo *loginfo,
f6ebe77f HW	112	const char *fmt, ...)
	113	{
	114	va_list args;
	115	char prefix[NF_LOG_PREFIXLEN];
7b2f9631	116	const struct nf_logger *logger;
601e68e1	117
f6ebe77f	118	rcu_read_lock();
e92ad99c	119	logger = rcu_dereference(nf_loggers[pf]);
f6ebe77f HW	120	if (logger) {
	121	va_start(args, fmt);
	122	vsnprintf(prefix, sizeof(prefix), fmt, args);
	123	va_end(args);
f6ebe77f	124	logger->logfn(pf, hooknum, skb, in, out, loginfo, prefix);
f6ebe77f HW	125	}
	126	rcu_read_unlock();
	127	}
	128	EXPORT_SYMBOL(nf_log_packet);
	129
	130	#ifdef CONFIG_PROC_FS
	131	static void seq_start(struct seq_file seq, loff_t *pos)
ca7c48ca	132	__acquires(RCU)
f6ebe77f HW	133	{
	134	rcu_read_lock();
	135
7e9c6eeb	136	if (*pos >= ARRAY_SIZE(nf_loggers))
f6ebe77f HW	137	return NULL;
	138
	139	return pos;
	140	}
	141
	142	static void seq_next(struct seq_file s, void v, loff_t pos)
	143	{
	144	(*pos)++;
	145
7e9c6eeb	146	if (*pos >= ARRAY_SIZE(nf_loggers))
f6ebe77f HW	147	return NULL;
	148
	149	return pos;
	150	}
	151
	152	static void seq_stop(struct seq_file s, void v)
ca7c48ca	153	__releases(RCU)
f6ebe77f HW	154	{
	155	rcu_read_unlock();
	156	}
	157
	158	static int seq_show(struct seq_file s, void v)
	159	{
	160	loff_t *pos = v;
	161	const struct nf_logger *logger;
c7a913cd EL	162	struct nf_logger *t;
c7a913cd EL	163	int ret;
f6ebe77f	164
e92ad99c	165	logger = rcu_dereference(nf_loggers[*pos]);
f6ebe77f HW	166
f6ebe77f HW	167	if (!logger)
c7a913cd EL	168	ret = seq_printf(s, "%2lld NONE (", *pos);
	169	else
	170	ret = seq_printf(s, "%2lld %s (", *pos, logger->name);
	171
	172	if (ret < 0)
	173	return ret;
	174
	175	mutex_lock(&nf_log_mutex);
	176	list_for_each_entry(t, &nf_loggers_l[pos], list[pos]) {
	177	ret = seq_printf(s, "%s", t->name);
	178	if (ret < 0) {
	179	mutex_unlock(&nf_log_mutex);
	180	return ret;
	181	}
	182	if (&t->list[pos] != nf_loggers_l[pos].prev) {
	183	ret = seq_printf(s, ",");
	184	if (ret < 0) {
	185	mutex_unlock(&nf_log_mutex);
	186	return ret;
	187	}
	188	}
	189	}
	190	mutex_unlock(&nf_log_mutex);
601e68e1	191
c7a913cd	192	return seq_printf(s, ")\n");
f6ebe77f HW	193	}
f6ebe77f HW	194
56b3d975	195	static const struct seq_operations nflog_seq_ops = {
f6ebe77f HW	196	.start = seq_start,
	197	.next = seq_next,
	198	.stop = seq_stop,
	199	.show = seq_show,
	200	};
	201
	202	static int nflog_open(struct inode inode, struct file file)
	203	{
	204	return seq_open(file, &nflog_seq_ops);
	205	}
	206
da7071d7	207	static const struct file_operations nflog_file_ops = {
f6ebe77f HW	208	.owner = THIS_MODULE,
	209	.open = nflog_open,
	210	.read = seq_read,
	211	.llseek = seq_lseek,
	212	.release = seq_release,
	213	};
	214
17625274	215
f6ebe77f HW	216	#endif /* PROC_FS */
f6ebe77f HW	217
17625274 EL	218	#ifdef CONFIG_SYSCTL
	219	struct ctl_path nf_log_sysctl_path[] = {
	220	{ .procname = "net", .ctl_name = CTL_NET, },
	221	{ .procname = "netfilter", .ctl_name = NET_NETFILTER, },
	222	{ .procname = "nf_log", .ctl_name = CTL_UNNUMBERED, },
	223	{ }
	224	};
	225
	226	static char nf_log_sysctl_fnames[NFPROTO_NUMPROTO-NFPROTO_UNSPEC][3];
	227	static struct ctl_table nf_log_sysctl_table[NFPROTO_NUMPROTO+1];
	228	static struct ctl_table_header *nf_log_dir_header;
f6ebe77f	229
17625274 EL	230	static int nf_log_proc_dostring(ctl_table table, int write, struct file filp,
	231	void buffer, size_t lenp, loff_t *ppos)
	232	{
	233	const struct nf_logger *logger;
	234	int r = 0;
	235	int tindex = (unsigned long)table->extra1;
	236
	237	if (write) {
	238	if (!strcmp(buffer, "NONE")) {
	239	nf_log_unbind_pf(tindex);
	240	return 0;
	241	}
	242	mutex_lock(&nf_log_mutex);
	243	logger = __find_logger(tindex, buffer);
	244	if (logger == NULL) {
	245	mutex_unlock(&nf_log_mutex);
	246	return -ENOENT;
	247	}
	248	rcu_assign_pointer(nf_loggers[tindex], logger);
	249	mutex_unlock(&nf_log_mutex);
	250	} else {
266d07cb PM	251	mutex_lock(&nf_log_mutex);
266d07cb PM	252	logger = nf_loggers[tindex];
17625274 EL	253	if (!logger)
	254	table->data = "NONE";
	255	else
	256	table->data = logger->name;
	257	r = proc_dostring(table, write, filp, buffer, lenp, ppos);
266d07cb	258	mutex_unlock(&nf_log_mutex);
17625274 EL	259	}
	260
	261	return r;
	262	}
	263
	264	static __init int netfilter_log_sysctl_init(void)
f6ebe77f	265	{
ca735b3a	266	int i;
17625274 EL	267
	268	for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
	269	snprintf(nf_log_sysctl_fnames[i-NFPROTO_UNSPEC], 3, "%d", i);
	270	nf_log_sysctl_table[i].ctl_name = CTL_UNNUMBERED;
	271	nf_log_sysctl_table[i].procname =
	272	nf_log_sysctl_fnames[i-NFPROTO_UNSPEC];
	273	nf_log_sysctl_table[i].data = NULL;
	274	nf_log_sysctl_table[i].maxlen =
	275	NFLOGGER_NAME_LEN * sizeof(char);
	276	nf_log_sysctl_table[i].mode = 0644;
	277	nf_log_sysctl_table[i].proc_handler = nf_log_proc_dostring;
	278	nf_log_sysctl_table[i].extra1 = (void *)(unsigned long) i;
	279	}
	280
	281	nf_log_dir_header = register_sysctl_paths(nf_log_sysctl_path,
	282	nf_log_sysctl_table);
	283	if (!nf_log_dir_header)
	284	return -ENOMEM;
	285
	286	return 0;
	287	}
	288	#else
	289	static __init int netfilter_log_sysctl_init(void)
	290	{
	291	return 0;
	292	}
	293	#endif /* CONFIG_SYSCTL */
	294
	295	int __init netfilter_log_init(void)
	296	{
	297	int i, r;
f6ebe77f	298	#ifdef CONFIG_PROC_FS
8eeee8b1 DL	299	if (!proc_create("nf_log", S_IRUGO,
8eeee8b1 DL	300	proc_net_netfilter, &nflog_file_ops))
f6ebe77f	301	return -1;
62243927	302	#endif
ca735b3a	303
17625274 EL	304	/* Errors will trigger panic, unroll on error is unnecessary. */
	305	r = netfilter_log_sysctl_init();
	306	if (r < 0)
	307	return r;
	308
ca735b3a EL	309	for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
	310	INIT_LIST_HEAD(&(nf_loggers_l[i]));
	311
f6ebe77f HW	312	return 0;
f6ebe77f HW	313	}