// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  UDPLITE     An implementation of the UDP-Lite protocol (RFC 3828).
 *
 *  Authors:    Gerrit Renker       <gerrit@erg.abdn.ac.uk>
 *
 *  Changes:
 *  Fixes:
 */

#define pr_fmt(fmt) "UDPLite: " fmt

#include <linux/export.h>
#include <linux/proc_fs.h>
#include "udp_impl.h"

struct udp_table        udplite_table __read_mostly;
EXPORT_SYMBOL(udplite_table);

/* Designate sk as UDP-Lite socket */
static int udplite_sk_init(struct sock *sk)
{
        pr_warn_once("UDP-Lite is deprecated and scheduled to be removed in 2025, "
                     "please contact the netdev mailing list\n");
        return udp_init_sock(sk);
}

static int udplite_rcv(struct sk_buff *skb)
{
        return __udp4_lib_rcv(skb, &udplite_table, IPPROTO_UDPLITE);
}

static int udplite_err(struct sk_buff *skb, u32 info)
{
        return __udp4_lib_err(skb, info, &udplite_table);
}

static const struct net_protocol udplite_protocol = {
        .handler        = udplite_rcv,
        .err_handler    = udplite_err,
        .no_policy      = 1,
};

struct proto    udplite_prot = {
        .name              = "UDP-Lite",
        .owner             = THIS_MODULE,
        .close             = udp_lib_close,
        .connect           = ip4_datagram_connect,
        .disconnect        = udp_disconnect,
        .ioctl             = udp_ioctl,
        .init              = udplite_sk_init,
        .destroy           = udp_destroy_sock,
        .setsockopt        = udp_setsockopt,
        .getsockopt        = udp_getsockopt,
        .sendmsg           = udp_sendmsg,
        .recvmsg           = udp_recvmsg,
        .hash              = udp_lib_hash,
        .unhash            = udp_lib_unhash,
        .rehash            = udp_v4_rehash,
        .get_port          = udp_v4_get_port,

        .memory_allocated  = &net_aligned_data.udp_memory_allocated,
        .per_cpu_fw_alloc  = &udp_memory_per_cpu_fw_alloc,

        .sysctl_mem        = sysctl_udp_mem,
        .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
        .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
        .obj_size          = sizeof(struct udp_sock),
        .h.udp_table       = &udplite_table,
};
EXPORT_SYMBOL(udplite_prot);

static struct inet_protosw udplite4_protosw = {
        .type           =  SOCK_DGRAM,
        .protocol       =  IPPROTO_UDPLITE,
        .prot           =  &udplite_prot,
        .ops            =  &inet_dgram_ops,
        .flags          =  INET_PROTOSW_PERMANENT,
};

#ifdef CONFIG_PROC_FS
static struct udp_seq_afinfo udplite4_seq_afinfo = {
        .family         = AF_INET,
        .udp_table      = &udplite_table,
};

static int __net_init udplite4_proc_init_net(struct net *net)
{
        if (!proc_create_net_data("udplite", 0444, net->proc_net, &udp_seq_ops,
                        sizeof(struct udp_iter_state), &udplite4_seq_afinfo))
                return -ENOMEM;
        return 0;
}

static void __net_exit udplite4_proc_exit_net(struct net *net)
{
        remove_proc_entry("udplite", net->proc_net);
}

static struct pernet_operations udplite4_net_ops = {
        .init = udplite4_proc_init_net,
        .exit = udplite4_proc_exit_net,
};

static __init int udplite4_proc_init(void)
{
        return register_pernet_subsys(&udplite4_net_ops);
}
#else
static inline int udplite4_proc_init(void)
{
        return 0;
}
#endif

void __init udplite4_register(void)
{
        udp_table_init(&udplite_table, "UDP-Lite");
        if (proto_register(&udplite_prot, 1))
                goto out_register_err;

        if (inet_add_protocol(&udplite_protocol, IPPROTO_UDPLITE) < 0)
                goto out_unregister_proto;

        inet_register_protosw(&udplite4_protosw);

        if (udplite4_proc_init())
                pr_err("%s: Cannot register /proc!\n", __func__);
        return;

out_unregister_proto:
        proto_unregister(&udplite_prot);
out_register_err:
        pr_crit("%s: Cannot add UDP-Lite protocol\n", __func__);
}