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Linux kernel mirror (for testing)
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linux
1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Definitions for the UDP module.
7 *
8 * Version: @(#)udp.h 1.0.2 05/07/93
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 *
13 * Fixes:
14 * Alan Cox : Turned on udp checksums. I don't want to
15 * chase 'memory corruption' bugs that aren't!
16 *
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
21 */
22#ifndef _UDP_H
23#define _UDP_H
24
25#include <linux/list.h>
26#include <linux/bug.h>
27#include <net/inet_sock.h>
28#include <net/sock.h>
29#include <net/snmp.h>
30#include <net/ip.h>
31#include <linux/ipv6.h>
32#include <linux/seq_file.h>
33#include <linux/poll.h>
34
35/**
36 * struct udp_skb_cb - UDP(-Lite) private variables
37 *
38 * @header: private variables used by IPv4/IPv6
39 * @cscov: checksum coverage length (UDP-Lite only)
40 * @partial_cov: if set indicates partial csum coverage
41 */
42struct udp_skb_cb {
43 union {
44 struct inet_skb_parm h4;
45#if IS_ENABLED(CONFIG_IPV6)
46 struct inet6_skb_parm h6;
47#endif
48 } header;
49 __u16 cscov;
50 __u8 partial_cov;
51};
52#define UDP_SKB_CB(__skb) ((struct udp_skb_cb *)((__skb)->cb))
53
54/**
55 * struct udp_hslot - UDP hash slot
56 *
57 * @head: head of list of sockets
58 * @count: number of sockets in 'head' list
59 * @lock: spinlock protecting changes to head/count
60 */
61struct udp_hslot {
62 struct hlist_nulls_head head;
63 int count;
64 spinlock_t lock;
65} __attribute__((aligned(2 * sizeof(long))));
66
67/**
68 * struct udp_table - UDP table
69 *
70 * @hash: hash table, sockets are hashed on (local port)
71 * @hash2: hash table, sockets are hashed on (local port, local address)
72 * @mask: number of slots in hash tables, minus 1
73 * @log: log2(number of slots in hash table)
74 */
75struct udp_table {
76 struct udp_hslot *hash;
77 struct udp_hslot *hash2;
78 unsigned int mask;
79 unsigned int log;
80};
81extern struct udp_table udp_table;
82void udp_table_init(struct udp_table *, const char *);
83static inline struct udp_hslot *udp_hashslot(struct udp_table *table,
84 struct net *net, unsigned int num)
85{
86 return &table->hash[udp_hashfn(net, num, table->mask)];
87}
88/*
89 * For secondary hash, net_hash_mix() is performed before calling
90 * udp_hashslot2(), this explains difference with udp_hashslot()
91 */
92static inline struct udp_hslot *udp_hashslot2(struct udp_table *table,
93 unsigned int hash)
94{
95 return &table->hash2[hash & table->mask];
96}
97
98extern struct proto udp_prot;
99
100extern atomic_long_t udp_memory_allocated;
101
102/* sysctl variables for udp */
103extern long sysctl_udp_mem[3];
104extern int sysctl_udp_rmem_min;
105extern int sysctl_udp_wmem_min;
106
107struct sk_buff;
108
109/*
110 * Generic checksumming routines for UDP(-Lite) v4 and v6
111 */
112static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
113{
114 return (UDP_SKB_CB(skb)->cscov == skb->len ?
115 __skb_checksum_complete(skb) :
116 __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov));
117}
118
119static inline int udp_lib_checksum_complete(struct sk_buff *skb)
120{
121 return !skb_csum_unnecessary(skb) &&
122 __udp_lib_checksum_complete(skb);
123}
124
125/**
126 * udp_csum_outgoing - compute UDPv4/v6 checksum over fragments
127 * @sk: socket we are writing to
128 * @skb: sk_buff containing the filled-in UDP header
129 * (checksum field must be zeroed out)
130 */
131static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
132{
133 __wsum csum = csum_partial(skb_transport_header(skb),
134 sizeof(struct udphdr), 0);
135 skb_queue_walk(&sk->sk_write_queue, skb) {
136 csum = csum_add(csum, skb->csum);
137 }
138 return csum;
139}
140
141static inline __wsum udp_csum(struct sk_buff *skb)
142{
143 __wsum csum = csum_partial(skb_transport_header(skb),
144 sizeof(struct udphdr), skb->csum);
145
146 for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) {
147 csum = csum_add(csum, skb->csum);
148 }
149 return csum;
150}
151
152static inline __sum16 udp_v4_check(int len, __be32 saddr,
153 __be32 daddr, __wsum base)
154{
155 return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base);
156}
157
158void udp_set_csum(bool nocheck, struct sk_buff *skb,
159 __be32 saddr, __be32 daddr, int len);
160
161/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
162static inline void udp_lib_hash(struct sock *sk)
163{
164 BUG();
165}
166
167void udp_lib_unhash(struct sock *sk);
168void udp_lib_rehash(struct sock *sk, u16 new_hash);
169
170static inline void udp_lib_close(struct sock *sk, long timeout)
171{
172 sk_common_release(sk);
173}
174
175int udp_lib_get_port(struct sock *sk, unsigned short snum,
176 int (*)(const struct sock *, const struct sock *),
177 unsigned int hash2_nulladdr);
178
179/* net/ipv4/udp.c */
180void udp_v4_early_demux(struct sk_buff *skb);
181int udp_get_port(struct sock *sk, unsigned short snum,
182 int (*saddr_cmp)(const struct sock *,
183 const struct sock *));
184void udp_err(struct sk_buff *, u32);
185int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
186 size_t len);
187int udp_push_pending_frames(struct sock *sk);
188void udp_flush_pending_frames(struct sock *sk);
189void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst);
190int udp_rcv(struct sk_buff *skb);
191int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
192int udp_disconnect(struct sock *sk, int flags);
193unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait);
194struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
195 netdev_features_t features);
196int udp_lib_getsockopt(struct sock *sk, int level, int optname,
197 char __user *optval, int __user *optlen);
198int udp_lib_setsockopt(struct sock *sk, int level, int optname,
199 char __user *optval, unsigned int optlen,
200 int (*push_pending_frames)(struct sock *));
201struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
202 __be32 daddr, __be16 dport, int dif);
203struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
204 __be32 daddr, __be16 dport, int dif,
205 struct udp_table *tbl);
206struct sock *udp6_lib_lookup(struct net *net,
207 const struct in6_addr *saddr, __be16 sport,
208 const struct in6_addr *daddr, __be16 dport,
209 int dif);
210struct sock *__udp6_lib_lookup(struct net *net,
211 const struct in6_addr *saddr, __be16 sport,
212 const struct in6_addr *daddr, __be16 dport,
213 int dif, struct udp_table *tbl);
214
215/*
216 * SNMP statistics for UDP and UDP-Lite
217 */
218#define UDP_INC_STATS_USER(net, field, is_udplite) do { \
219 if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field); \
220 else SNMP_INC_STATS_USER((net)->mib.udp_statistics, field); } while(0)
221#define UDP_INC_STATS_BH(net, field, is_udplite) do { \
222 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field); \
223 else SNMP_INC_STATS_BH((net)->mib.udp_statistics, field); } while(0)
224
225#define UDP6_INC_STATS_BH(net, field, is_udplite) do { \
226 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\
227 else SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field); \
228} while(0)
229#define UDP6_INC_STATS_USER(net, field, __lite) do { \
230 if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field); \
231 else SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field); \
232} while(0)
233
234#if IS_ENABLED(CONFIG_IPV6)
235#define UDPX_INC_STATS_BH(sk, field) \
236do { \
237 if ((sk)->sk_family == AF_INET) \
238 UDP_INC_STATS_BH(sock_net(sk), field, 0); \
239 else \
240 UDP6_INC_STATS_BH(sock_net(sk), field, 0); \
241} while (0)
242#else
243#define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0)
244#endif
245
246/* /proc */
247int udp_seq_open(struct inode *inode, struct file *file);
248
249struct udp_seq_afinfo {
250 char *name;
251 sa_family_t family;
252 struct udp_table *udp_table;
253 const struct file_operations *seq_fops;
254 struct seq_operations seq_ops;
255};
256
257struct udp_iter_state {
258 struct seq_net_private p;
259 sa_family_t family;
260 int bucket;
261 struct udp_table *udp_table;
262};
263
264#ifdef CONFIG_PROC_FS
265int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);
266void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo);
267
268int udp4_proc_init(void);
269void udp4_proc_exit(void);
270#endif
271
272int udpv4_offload_init(void);
273
274void udp_init(void);
275
276void udp_encap_enable(void);
277#if IS_ENABLED(CONFIG_IPV6)
278void udpv6_encap_enable(void);
279#endif
280#endif /* _UDP_H */