net/netfilter/nf_hooks_lwtunnel.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include <linux/sysctl.h>
   4 #include <net/lwtunnel.h>
   5 #include <net/netfilter/nf_hooks_lwtunnel.h>
   6
   7 static inline int nf_hooks_lwtunnel_get(void)
   8 {
   9         if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
  10                 return 1;
  11         else
  12                 return 0;
  13 }
  14
  15 static inline int nf_hooks_lwtunnel_set(int enable)
  16 {
  17         if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) {
  18                 if (!enable)
  19                         return -EBUSY;
  20         } else if (enable) {
  21                 static_branch_enable(&nf_hooks_lwtunnel_enabled);
  22         }
  23
  24         return 0;
  25 }
  26
  27 #ifdef CONFIG_SYSCTL
  28 int nf_hooks_lwtunnel_sysctl_handler(struct ctl_table *table, int write,
  29                                      void *buffer, size_t *lenp, loff_t *ppos)
  30 {
  31         int proc_nf_hooks_lwtunnel_enabled = 0;
  32         struct ctl_table tmp = {
  33                 .procname = table->procname,
  34                 .data = &proc_nf_hooks_lwtunnel_enabled,
  35                 .maxlen = sizeof(int),
  36                 .mode = table->mode,
  37                 .extra1 = SYSCTL_ZERO,
  38                 .extra2 = SYSCTL_ONE,
  39         };
  40         int ret;
  41
  42         if (!write)
  43                 proc_nf_hooks_lwtunnel_enabled = nf_hooks_lwtunnel_get();
  44
  45         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
  46
  47         if (write && ret == 0)
  48                 ret = nf_hooks_lwtunnel_set(proc_nf_hooks_lwtunnel_enabled);
  49
  50         return ret;
  51 }
  52 EXPORT_SYMBOL_GPL(nf_hooks_lwtunnel_sysctl_handler);
  53 #endif /* CONFIG_SYSCTL */