// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * INET         An implementation of the TCP/IP protocol suite for the LINUX
 *              operating system.  INET is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              INET protocol dispatch tables.
 *
 * Authors:     Ross Biro
 *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *
 * Fixes:
 *              Alan Cox        : Ahah! udp icmp errors don't work because
 *                                udp_err is never called!
 *              Alan Cox        : Added new fields for init and ready for
 *                                proper fragmentation (_NO_ 4K limits!)
 *              Richard Colella : Hang on hash collision
 *              Vince Laviano   : Modified inet_del_protocol() to correctly
 *                                maintain copy bit.
 */
#include <linux/cache.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <net/protocol.h>

struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly;
EXPORT_SYMBOL(inet_protos);
const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly;
EXPORT_SYMBOL(inet_offloads);

int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
{
        return !cmpxchg((const struct net_protocol **)&inet_protos[protocol],
                        NULL, prot) ? 0 : -1;
}
EXPORT_SYMBOL(inet_add_protocol);

int inet_add_offload(const struct net_offload *prot, unsigned char protocol)
{
        return !cmpxchg((const struct net_offload **)&inet_offloads[protocol],
                        NULL, prot) ? 0 : -1;
}
EXPORT_SYMBOL(inet_add_offload);

int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
{
        int ret;

        ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol],
                       prot, NULL) == prot) ? 0 : -1;

        synchronize_net();

        return ret;
}
EXPORT_SYMBOL(inet_del_protocol);

int inet_del_offload(const struct net_offload *prot, unsigned char protocol)
{
        int ret;

        ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol],
                       prot, NULL) == prot) ? 0 : -1;

        synchronize_net();

        return ret;
}
EXPORT_SYMBOL(inet_del_offload);