xref: /kernel/linux/linux-5.10/net/ipv4/udplite.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  UDPLITE     An implementation of the UDP-Lite protocol (RFC 3828).
4 *
5 *  Authors:    Gerrit Renker       <gerrit@erg.abdn.ac.uk>
6 *
7 *  Changes:
8 *  Fixes:
9 */
10
11#define pr_fmt(fmt) "UDPLite: " fmt
12
13#include <linux/export.h>
14#include <linux/proc_fs.h>
15#include "udp_impl.h"
16
17struct udp_table 	udplite_table __read_mostly;
18EXPORT_SYMBOL(udplite_table);
19
20/* Designate sk as UDP-Lite socket */
21static int udplite_sk_init(struct sock *sk)
22{
23	udp_init_sock(sk);
24	udp_sk(sk)->pcflag = UDPLITE_BIT;
25	return 0;
26}
27
28static int udplite_rcv(struct sk_buff *skb)
29{
30	return __udp4_lib_rcv(skb, &udplite_table, IPPROTO_UDPLITE);
31}
32
33static int udplite_err(struct sk_buff *skb, u32 info)
34{
35	return __udp4_lib_err(skb, info, &udplite_table);
36}
37
38static const struct net_protocol udplite_protocol = {
39	.handler	= udplite_rcv,
40	.err_handler	= udplite_err,
41	.no_policy	= 1,
42	.netns_ok	= 1,
43};
44
45struct proto 	udplite_prot = {
46	.name		   = "UDP-Lite",
47	.owner		   = THIS_MODULE,
48	.close		   = udp_lib_close,
49	.connect	   = ip4_datagram_connect,
50	.disconnect	   = udp_disconnect,
51	.ioctl		   = udp_ioctl,
52	.init		   = udplite_sk_init,
53	.destroy	   = udp_destroy_sock,
54	.setsockopt	   = udp_setsockopt,
55	.getsockopt	   = udp_getsockopt,
56	.sendmsg	   = udp_sendmsg,
57	.recvmsg	   = udp_recvmsg,
58	.sendpage	   = udp_sendpage,
59	.hash		   = udp_lib_hash,
60	.unhash		   = udp_lib_unhash,
61	.rehash		   = udp_v4_rehash,
62	.get_port	   = udp_v4_get_port,
63	.memory_allocated  = &udp_memory_allocated,
64	.sysctl_mem	   = sysctl_udp_mem,
65	.sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
66	.sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
67	.obj_size	   = sizeof(struct udp_sock),
68	.h.udp_table	   = &udplite_table,
69};
70EXPORT_SYMBOL(udplite_prot);
71
72static struct inet_protosw udplite4_protosw = {
73	.type		=  SOCK_DGRAM,
74	.protocol	=  IPPROTO_UDPLITE,
75	.prot		=  &udplite_prot,
76	.ops		=  &inet_dgram_ops,
77	.flags		=  INET_PROTOSW_PERMANENT,
78};
79
80#ifdef CONFIG_PROC_FS
81static struct udp_seq_afinfo udplite4_seq_afinfo = {
82	.family		= AF_INET,
83	.udp_table 	= &udplite_table,
84};
85
86static int __net_init udplite4_proc_init_net(struct net *net)
87{
88	if (!proc_create_net_data("udplite", 0444, net->proc_net, &udp_seq_ops,
89			sizeof(struct udp_iter_state), &udplite4_seq_afinfo))
90		return -ENOMEM;
91	return 0;
92}
93
94static void __net_exit udplite4_proc_exit_net(struct net *net)
95{
96	remove_proc_entry("udplite", net->proc_net);
97}
98
99static struct pernet_operations udplite4_net_ops = {
100	.init = udplite4_proc_init_net,
101	.exit = udplite4_proc_exit_net,
102};
103
104static __init int udplite4_proc_init(void)
105{
106	return register_pernet_subsys(&udplite4_net_ops);
107}
108#else
109static inline int udplite4_proc_init(void)
110{
111	return 0;
112}
113#endif
114
115void __init udplite4_register(void)
116{
117	udp_table_init(&udplite_table, "UDP-Lite");
118	if (proto_register(&udplite_prot, 1))
119		goto out_register_err;
120
121	if (inet_add_protocol(&udplite_protocol, IPPROTO_UDPLITE) < 0)
122		goto out_unregister_proto;
123
124	inet_register_protosw(&udplite4_protosw);
125
126	if (udplite4_proc_init())
127		pr_err("%s: Cannot register /proc!\n", __func__);
128	return;
129
130out_unregister_proto:
131	proto_unregister(&udplite_prot);
132out_register_err:
133	pr_crit("%s: Cannot add UDP-Lite protocol\n", __func__);
134}
135