Commit 17625274 authored by Eric Leblond's avatar Eric Leblond Committed by Patrick McHardy
Browse files

netfilter: sysctl support of logger choice 



This patchs adds support of modification of the used logger via sysctl.
It can be used to change the logger to module that can not use the bind
operation (ipt_LOG and ipt_ULOG). For this purpose, it creates a
directory /proc/sys/net/netfilter/nf_log which contains a file
per-protocol. The content of the file is the name current logger (NONE if
not set) and a logger can be setup by simply echoing its name to the file.
By echoing "NONE" to a /proc/sys/net/netfilter/nf_log/PROTO file, the
logger corresponding to this PROTO is set to NULL.

Signed-off-by: default avatarEric Leblond <eric@inl.fr>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 0f5b3e85

net/netfilter/nf_log.c

+84 −1
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
   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;
@@ -207,18 +208,100 @@ static const struct file_operations nflog_file_ops = { 
	.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, },

	{ }

};



int __init netfilter_log_init(void)

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 {

		rcu_read_lock();

		logger = rcu_dereference(nf_loggers[tindex]);

		if (!logger)

			table->data = "NONE";

		else

			table->data = logger->name;

		r = proc_dostring(table, write, filp, buffer, lenp, ppos);

		rcu_read_unlock();

	}



	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]));

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