1 files changed, 172 insertions, 0 deletions
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
new file mode 100644
index 0000000..fa8ae5d
--- /dev/null
+++ b/net/netfilter/nf_log.c
@@ -0,0 +1,172 @@
+#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;
+}