udplite.c

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/*
 *  UDPLITE     An implementation of the UDP-Lite protocol (RFC 3828).
 *
 *  Authors:    Gerrit Renker       <[email protected]>
 *
 *  Changes:
 *  Fixes:
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#define pr_fmt(fmt) "UDPLite: " fmt

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

struct udp_table    udplite_table __read_mostly;
EXPORT_SYMBOL(udplite_table);

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

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

static const struct net_protocol udplite_protocol = {
    .handler    = udplite_rcv,
    .err_handler    = udplite_err,
    .no_policy  = 1,
    .netns_ok   = 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,
    .sendpage      = udp_sendpage,
    .backlog_rcv       = udp_queue_rcv_skb,
    .hash          = udp_lib_hash,
    .unhash        = udp_lib_unhash,
    .get_port      = udp_v4_get_port,
    .obj_size      = sizeof(struct udp_sock),
    .slab_flags    = SLAB_DESTROY_BY_RCU,
    .h.udp_table       = &udplite_table,
#ifdef CONFIG_COMPAT
    .compat_setsockopt = compat_udp_setsockopt,
    .compat_getsockopt = compat_udp_getsockopt,
#endif
    .clear_sk      = sk_prot_clear_portaddr_nulls,
};
EXPORT_SYMBOL(udplite_prot);

static struct inet_protosw udplite4_protosw = {
    .type       =  SOCK_DGRAM,
    .protocol   =  IPPROTO_UDPLITE,
    .prot       =  &udplite_prot,
    .ops        =  &inet_dgram_ops,
    .no_check   =  0,       /* must checksum (RFC 3828) */
    .flags      =  INET_PROTOSW_PERMANENT,
};

#ifdef CONFIG_PROC_FS

static const struct file_operations udplite_afinfo_seq_fops = {
    .owner    = THIS_MODULE,
    .open     = udp_seq_open,
    .read     = seq_read,
    .llseek   = seq_lseek,
    .release  = seq_release_net
};

static struct udp_seq_afinfo udplite4_seq_afinfo = {
    .name       = "udplite",
    .family     = AF_INET,
    .udp_table  = &udplite_table,
    .seq_fops   = &udplite_afinfo_seq_fops,
    .seq_ops    = {
        .show       = udp4_seq_show,
    },
};

static int __net_init udplite4_proc_init_net(struct net *net)
{
    return udp_proc_register(net, &udplite4_seq_afinfo);
}

static void __net_exit udplite4_proc_exit_net(struct net *net)
{
    udp_proc_unregister(net, &udplite4_seq_afinfo);
}

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__);
}