net/ipv6/protocol.c

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              PF_INET6 protocol dispatch tables.
   7  *
   8  * Authors:     Pedro Roque     <roque@di.fc.ul.pt>
   9  *
  10  *              This program is free software; you can redistribute it and/or
  11  *              modify it under the terms of the GNU General Public License
  12  *              as published by the Free Software Foundation; either version
  13  *              2 of the License, or (at your option) any later version.
  14  */
  15
  16 /*
  17  *      Changes:
  18  *
  19  *      Vince Laviano (vince@cs.stanford.edu)       16 May 2001
  20  *      - Removed unused variable 'inet6_protocol_base'
  21  *      - Modified inet6_del_protocol() to correctly maintain copy bit.
  22  */
  23 #include <linux/module.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/spinlock.h>
  26 #include <net/protocol.h>
  27
  28 const struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS] __read_mostly;
  29 const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS] __read_mostly;
  30
  31 int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char protocol)
  32 {
  33         return !cmpxchg((const struct inet6_protocol **)&inet6_protos[protocol],
  34                         NULL, prot) ? 0 : -1;
  35 }
  36 EXPORT_SYMBOL(inet6_add_protocol);
  37
  38 int inet6_add_offload(const struct net_offload *prot, unsigned char protocol)
  39 {
  40         return !cmpxchg((const struct net_offload **)&inet6_offloads[protocol],
  41                         NULL, prot) ? 0 : -1;
  42 }
  43 EXPORT_SYMBOL(inet6_add_offload);
  44
  45 /*
  46  *      Remove a protocol from the hash tables.
  47  */
  48
  49 int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char protocol)
  50 {
  51         int ret;
  52
  53         ret = (cmpxchg((const struct inet6_protocol **)&inet6_protos[protocol],
  54                        prot, NULL) == prot) ? 0 : -1;
  55
  56         synchronize_net();
  57
  58         return ret;
  59 }
  60 EXPORT_SYMBOL(inet6_del_protocol);
  61
  62 int inet6_del_offload(const struct net_offload *prot, unsigned char protocol)
  63 {
  64         int ret;
  65
  66         ret = (cmpxchg((const struct net_offload **)&inet6_offloads[protocol],
  67                        prot, NULL) == prot) ? 0 : -1;
  68
  69         synchronize_net();
  70
  71         return ret;
  72 }
  73 EXPORT_SYMBOL(inet6_del_offload);