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  * Version:     $Id: protocol.c,v 1.10 2001/05/18 02:25:49 davem Exp $
   9  *
  10  * Authors:     Pedro Roque     <roque@di.fc.ul.pt>
  11  *
  12  *              This program is free software; you can redistribute it and/or
  13  *              modify it under the terms of the GNU General Public License
  14  *              as published by the Free Software Foundation; either version
  15  *              2 of the License, or (at your option) any later version.
  16  */
  17
  18 /*
  19  *      Changes:
  20  *
  21  *      Vince Laviano (vince@cs.stanford.edu)       16 May 2001
  22  *      - Removed unused variable 'inet6_protocol_base'
  23  *      - Modified inet6_del_protocol() to correctly maintain copy bit.
  24  */
  25
  26 #include <linux/errno.h>
  27 #include <linux/types.h>
  28 #include <linux/socket.h>
  29 #include <linux/sockios.h>
  30 #include <linux/sched.h>
  31 #include <linux/net.h>
  32 #include <linux/in6.h>
  33 #include <linux/netdevice.h>
  34 #include <linux/if_arp.h>
  35
  36 #include <net/sock.h>
  37 #include <net/snmp.h>
  38
  39 #include <net/ipv6.h>
  40 #include <net/protocol.h>
  41
  42 struct inet6_protocol *inet6_protos[MAX_INET_PROTOS];
  43 static DEFINE_SPINLOCK(inet6_proto_lock);
  44
  45
  46 int inet6_add_protocol(struct inet6_protocol *prot, unsigned char protocol)
  47 {
  48         int ret, hash = protocol & (MAX_INET_PROTOS - 1);
  49
  50         spin_lock_bh(&inet6_proto_lock);
  51
  52         if (inet6_protos[hash]) {
  53                 ret = -1;
  54         } else {
  55                 inet6_protos[hash] = prot;
  56                 ret = 0;
  57         }
  58
  59         spin_unlock_bh(&inet6_proto_lock);
  60
  61         return ret;
  62 }
  63
  64 /*
  65  *      Remove a protocol from the hash tables.
  66  */
  67
  68 int inet6_del_protocol(struct inet6_protocol *prot, unsigned char protocol)
  69 {
  70         int ret, hash = protocol & (MAX_INET_PROTOS - 1);
  71
  72         spin_lock_bh(&inet6_proto_lock);
  73
  74         if (inet6_protos[hash] != prot) {
  75                 ret = -1;
  76         } else {
  77                 inet6_protos[hash] = NULL;
  78                 ret = 0;
  79         }
  80
  81         spin_unlock_bh(&inet6_proto_lock);
  82
  83         synchronize_net();
  84
  85         return ret;
  86 }