1 files changed, 112 insertions, 0 deletions
diff --git a/net/netfilter/ipvs/ip_vs_pe.c b/net/netfilter/ipvs/ip_vs_pe.c
new file mode 100644
index 000000000..166c669f0
--- /dev/null
+++ b/net/netfilter/ipvs/ip_vs_pe.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define KMSG_COMPONENT "IPVS"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <asm/string.h>
+#include <linux/kmod.h>
+#include <linux/sysctl.h>
+
+#include <net/ip_vs.h>
+
+/* IPVS pe list */
+static LIST_HEAD(ip_vs_pe);
+
+/* semaphore for IPVS PEs. */
+static DEFINE_MUTEX(ip_vs_pe_mutex);
+
+/* Get pe in the pe list by name */
+struct ip_vs_pe *__ip_vs_pe_getbyname(const char *pe_name)
+{
+	struct ip_vs_pe *pe;
+
+	IP_VS_DBG(10, "%s(): pe_name \"%s\"\n", __func__,
+		  pe_name);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(pe, &ip_vs_pe, n_list) {
+		/* Test and get the modules atomically */
+		if (pe->module &&
+		    !try_module_get(pe->module)) {
+			/* This pe is just deleted */
+			continue;
+		}
+		if (strcmp(pe_name, pe->name)==0) {
+			/* HIT */
+			rcu_read_unlock();
+			return pe;
+		}
+		module_put(pe->module);
+	}
+	rcu_read_unlock();
+
+	return NULL;
+}
+
+/* Lookup pe and try to load it if it doesn't exist */
+struct ip_vs_pe *ip_vs_pe_getbyname(const char *name)
+{
+	struct ip_vs_pe *pe;
+
+	/* Search for the pe by name */
+	pe = __ip_vs_pe_getbyname(name);
+
+	/* If pe not found, load the module and search again */
+	if (!pe) {
+		request_module("ip_vs_pe_%s", name);
+		pe = __ip_vs_pe_getbyname(name);
+	}
+
+	return pe;
+}
+
+/* Register a pe in the pe list */
+int register_ip_vs_pe(struct ip_vs_pe *pe)
+{
+	struct ip_vs_pe *tmp;
+
+	/* increase the module use count */
+	if (!ip_vs_use_count_inc())
+		return -ENOENT;
+
+	mutex_lock(&ip_vs_pe_mutex);
+	/* Make sure that the pe with this name doesn't exist
+	 * in the pe list.
+	 */
+	list_for_each_entry(tmp, &ip_vs_pe, n_list) {
+		if (strcmp(tmp->name, pe->name) == 0) {
+			mutex_unlock(&ip_vs_pe_mutex);
+			ip_vs_use_count_dec();
+			pr_err("%s(): [%s] pe already existed "
+			       "in the system\n", __func__, pe->name);
+			return -EINVAL;
+		}
+	}
+	/* Add it into the d-linked pe list */
+	list_add_rcu(&pe->n_list, &ip_vs_pe);
+	mutex_unlock(&ip_vs_pe_mutex);
+
+	pr_info("[%s] pe registered.\n", pe->name);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(register_ip_vs_pe);
+
+/* Unregister a pe from the pe list */
+int unregister_ip_vs_pe(struct ip_vs_pe *pe)
+{
+	mutex_lock(&ip_vs_pe_mutex);
+	/* Remove it from the d-linked pe list */
+	list_del_rcu(&pe->n_list);
+	mutex_unlock(&ip_vs_pe_mutex);
+
+	/* decrease the module use count */
+	ip_vs_use_count_dec();
+
+	pr_info("[%s] pe unregistered.\n", pe->name);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(unregister_ip_vs_pe);