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
  24 #include <linux/errno.h>
  25 #include <linux/types.h>
  26 #include <linux/socket.h>
  27 #include <linux/sockios.h>
  28 #include <linux/net.h>
  29 #include <linux/in6.h>
  30 #include <linux/netdevice.h>
  31 #include <linux/if_arp.h>
  32
  33 #include <net/sock.h>
  34 #include <net/snmp.h>
  35
  36 #include <net/ipv6.h>
  37 #include <net/protocol.h>
  38
  39 struct inet6_protocol *inet6_protos[MAX_INET_PROTOS];
  40 static DEFINE_SPINLOCK(inet6_proto_lock);
  41
  42
  43 int inet6_add_protocol(struct inet6_protocol *prot, unsigned char protocol)
  44 {
  45         int ret, hash = protocol & (MAX_INET_PROTOS - 1);
  46
  47         spin_lock_bh(&inet6_proto_lock);
  48
  49         if (inet6_protos[hash]) {
  50                 ret = -1;
  51         } else {
  52                 inet6_protos[hash] = prot;
  53                 ret = 0;
  54         }
  55
  56         spin_unlock_bh(&inet6_proto_lock);
  57
  58         return ret;
  59 }
  60
  61 EXPORT_SYMBOL(inet6_add_protocol);
  62
  63 /*
  64  *      Remove a protocol from the hash tables.
  65  */
  66
  67 int inet6_del_protocol(struct inet6_protocol *prot, unsigned char protocol)
  68 {
  69         int ret, hash = protocol & (MAX_INET_PROTOS - 1);
  70
  71         spin_lock_bh(&inet6_proto_lock);
  72
  73         if (inet6_protos[hash] != prot) {
  74                 ret = -1;
  75         } else {
  76                 inet6_protos[hash] = NULL;
  77                 ret = 0;
  78         }
  79
  80         spin_unlock_bh(&inet6_proto_lock);
  81
  82         synchronize_net();
  83
  84         return ret;
  85 }
  86
  87 EXPORT_SYMBOL(inet6_del_protocol);