Merge tag 'v2.6.37' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / net / netfilter / ipvs / ip_vs_pe.c

diff --git a/net/netfilter/ipvs/ip_vs_pe.c b/net/netfilter/ipvs/ip_vs_pe.c
new file mode 100644 (file)
index 0000000..3414af7
--- /dev/null
+++ b/net/netfilter/ipvs/ip_vs_pe.c
@@ -0,0 +1,147 @@
+#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);
+
+/* lock for service table */
+static DEFINE_SPINLOCK(ip_vs_pe_lock);
+
+/* Bind a service with a pe */
+void ip_vs_bind_pe(struct ip_vs_service *svc, struct ip_vs_pe *pe)
+{
+       svc->pe = pe;
+}
+
+/* Unbind a service from its pe */
+void ip_vs_unbind_pe(struct ip_vs_service *svc)
+{
+       svc->pe = NULL;
+}
+
+/* Get pe in the pe list by name */
+static struct ip_vs_pe *
+ip_vs_pe_getbyname(const char *pe_name)
+{
+       struct ip_vs_pe *pe;
+
+       IP_VS_DBG(2, "%s(): pe_name \"%s\"\n", __func__,
+                 pe_name);
+
+       spin_lock_bh(&ip_vs_pe_lock);
+
+       list_for_each_entry(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 */
+                       spin_unlock_bh(&ip_vs_pe_lock);
+                       return pe;
+               }
+               if (pe->module)
+                       module_put(pe->module);
+       }
+
+       spin_unlock_bh(&ip_vs_pe_lock);
+       return NULL;
+}
+
+/* Lookup pe and try to load it if it doesn't exist */
+struct ip_vs_pe *ip_vs_pe_get(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;
+}
+
+void ip_vs_pe_put(struct ip_vs_pe *pe)
+{
+       if (pe && pe->module)
+               module_put(pe->module);
+}
+
+/* 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 */
+       ip_vs_use_count_inc();
+
+       spin_lock_bh(&ip_vs_pe_lock);
+
+       if (!list_empty(&pe->n_list)) {
+               spin_unlock_bh(&ip_vs_pe_lock);
+               ip_vs_use_count_dec();
+               pr_err("%s(): [%s] pe already linked\n",
+                      __func__, pe->name);
+               return -EINVAL;
+       }
+
+       /* 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) {
+                       spin_unlock_bh(&ip_vs_pe_lock);
+                       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(&pe->n_list, &ip_vs_pe);
+       spin_unlock_bh(&ip_vs_pe_lock);
+
+       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)
+{
+       spin_lock_bh(&ip_vs_pe_lock);
+       if (list_empty(&pe->n_list)) {
+               spin_unlock_bh(&ip_vs_pe_lock);
+               pr_err("%s(): [%s] pe is not in the list. failed\n",
+                      __func__, pe->name);
+               return -EINVAL;
+       }
+
+       /* Remove it from the d-linked pe list */
+       list_del(&pe->n_list);
+       spin_unlock_bh(&ip_vs_pe_lock);
+
+       /* 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);