net/ipv6/protocol.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   4  *              operating system.  INET is implemented using the  BSD Socket
   5  *              interface as the means of communication with the user level.
   6  *
   7  *              PF_INET6 protocol dispatch tables.
   8  *
   9  * Authors:     Pedro Roque     <roque@di.fc.ul.pt>
  10  */
  11
  12 /*
  13  *      Changes:
  14  *
  15  *      Vince Laviano (vince@cs.stanford.edu)       16 May 2001
  16  *      - Removed unused variable 'inet6_protocol_base'
  17  *      - Modified inet6_del_protocol() to correctly maintain copy bit.
  18  */
  19 #include <linux/module.h>
  20 #include <linux/netdevice.h>
  21 #include <linux/spinlock.h>
  22 #include <net/protocol.h>
  23
  24 #if IS_ENABLED(CONFIG_IPV6)
  25 struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS] __read_mostly;
  26 EXPORT_SYMBOL(inet6_protos);
  27
  28 int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char protocol)
  29 {
  30         return !cmpxchg((const struct inet6_protocol **)&inet6_protos[protocol],
  31                         NULL, prot) ? 0 : -1;
  32 }
  33 EXPORT_SYMBOL(inet6_add_protocol);
  34
  35 int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char protocol)
  36 {
  37         int ret;
  38
  39         ret = (cmpxchg((const struct inet6_protocol **)&inet6_protos[protocol],
  40                        prot, NULL) == prot) ? 0 : -1;
  41
  42         synchronize_net();
  43
  44         return ret;
  45 }
  46 EXPORT_SYMBOL(inet6_del_protocol);
  47 #endif
  48
  49 const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS] __read_mostly;
  50 EXPORT_SYMBOL(inet6_offloads);
  51
  52 int inet6_add_offload(const struct net_offload *prot, unsigned char protocol)
  53 {
  54         return !cmpxchg((const struct net_offload **)&inet6_offloads[protocol],
  55                         NULL, prot) ? 0 : -1;
  56 }
  57 EXPORT_SYMBOL(inet6_add_offload);
  58
  59 int inet6_del_offload(const struct net_offload *prot, unsigned char protocol)
  60 {
  61         int ret;
  62
  63         ret = (cmpxchg((const struct net_offload **)&inet6_offloads[protocol],
  64                        prot, NULL) == prot) ? 0 : -1;
  65
  66         synchronize_net();
  67
  68         return ret;
  69 }
  70 EXPORT_SYMBOL(inet6_del_offload);