net/ipv6/protocol.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * INET     An implementation of the TCP/IP protocol suite for the LINUX
0004  *      operating system.  INET is implemented using the  BSD Socket
0005  *      interface as the means of communication with the user level.
0006  *
0007  *      PF_INET6 protocol dispatch tables.
0008  *
0009  * Authors: Pedro Roque <roque@di.fc.ul.pt>
0010  */
0011
0012 /*
0013  *      Changes:
0014  *
0015  *      Vince Laviano (vince@cs.stanford.edu)       16 May 2001
0016  *      - Removed unused variable 'inet6_protocol_base'
0017  *      - Modified inet6_del_protocol() to correctly maintain copy bit.
0018  */
0019 #include <linux/module.h>
0020 #include <linux/netdevice.h>
0021 #include <linux/spinlock.h>
0022 #include <net/protocol.h>
0023
0024 #if IS_ENABLED(CONFIG_IPV6)
0025 struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS] __read_mostly;
0026 EXPORT_SYMBOL(inet6_protos);
0027
0028 int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char protocol)
0029 {
0030     return !cmpxchg((const struct inet6_protocol **)&inet6_protos[protocol],
0031             NULL, prot) ? 0 : -1;
0032 }
0033 EXPORT_SYMBOL(inet6_add_protocol);
0034
0035 int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char protocol)
0036 {
0037     int ret;
0038
0039     ret = (cmpxchg((const struct inet6_protocol **)&inet6_protos[protocol],
0040                prot, NULL) == prot) ? 0 : -1;
0041
0042     synchronize_net();
0043
0044     return ret;
0045 }
0046 EXPORT_SYMBOL(inet6_del_protocol);
0047 #endif
0048
0049 const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS] __read_mostly;
0050 EXPORT_SYMBOL(inet6_offloads);
0051
0052 int inet6_add_offload(const struct net_offload *prot, unsigned char protocol)
0053 {
0054     return !cmpxchg((const struct net_offload **)&inet6_offloads[protocol],
0055             NULL, prot) ? 0 : -1;
0056 }
0057 EXPORT_SYMBOL(inet6_add_offload);
0058
0059 int inet6_del_offload(const struct net_offload *prot, unsigned char protocol)
0060 {
0061     int ret;
0062
0063     ret = (cmpxchg((const struct net_offload **)&inet6_offloads[protocol],
0064                prot, NULL) == prot) ? 0 : -1;
0065
0066     synchronize_net();
0067
0068     return ret;
0069 }
0070 EXPORT_SYMBOL(inet6_del_offload);