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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
98/* Note: this must match 'valbool' in sock_setsockopt */
99#define UDP_CSUM_NOXMIT 1
100
101/* Used by SunRPC/xprt layer. */
102#define UDP_CSUM_NORCV 2
103
104/* Default, as per the RFC, is to always do csums. */
105#define UDP_CSUM_DEFAULT 0
106
107extern struct proto udp_prot;
108
109extern atomic_long_t udp_memory_allocated;
110
111/* sysctl variables for udp */
112extern long sysctl_udp_mem[3];
113extern int sysctl_udp_rmem_min;
114extern int sysctl_udp_wmem_min;
115
116struct sk_buff;
117
118/*
119 * Generic checksumming routines for UDP(-Lite) v4 and v6
120 */
121static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
122{
123 return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov);
124}
125
126static inline int udp_lib_checksum_complete(struct sk_buff *skb)
127{
128 return !skb_csum_unnecessary(skb) &&
129 __udp_lib_checksum_complete(skb);
130}
131
132/**
133 * udp_csum_outgoing - compute UDPv4/v6 checksum over fragments
134 * @sk: socket we are writing to
135 * @skb: sk_buff containing the filled-in UDP header
136 * (checksum field must be zeroed out)
137 */
138static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
139{
140 __wsum csum = csum_partial(skb_transport_header(skb),
141 sizeof(struct udphdr), 0);
142 skb_queue_walk(&sk->sk_write_queue, skb) {
143 csum = csum_add(csum, skb->csum);
144 }
145 return csum;
146}
147
148static inline __wsum udp_csum(struct sk_buff *skb)
149{
150 __wsum csum = csum_partial(skb_transport_header(skb),
151 sizeof(struct udphdr), skb->csum);
152
153 for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) {
154 csum = csum_add(csum, skb->csum);
155 }
156 return csum;
157}
158
159/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
160static inline void udp_lib_hash(struct sock *sk)
161{
162 BUG();
163}
164
165void udp_lib_unhash(struct sock *sk);
166void udp_lib_rehash(struct sock *sk, u16 new_hash);
167
168static inline void udp_lib_close(struct sock *sk, long timeout)
169{
170 sk_common_release(sk);
171}
172
173int udp_lib_get_port(struct sock *sk, unsigned short snum,
174 int (*)(const struct sock *, const struct sock *),
175 unsigned int hash2_nulladdr);
176
177/* net/ipv4/udp.c */
178void udp_v4_early_demux(struct sk_buff *skb);
179int udp_get_port(struct sock *sk, unsigned short snum,
180 int (*saddr_cmp)(const struct sock *,
181 const struct sock *));
182void udp_err(struct sk_buff *, u32);
183int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
184 size_t len);
185int udp_push_pending_frames(struct sock *sk);
186void udp_flush_pending_frames(struct sock *sk);
187void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst);
188int udp_rcv(struct sk_buff *skb);
189int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
190int udp_disconnect(struct sock *sk, int flags);
191unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait);
192struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
193 netdev_features_t features);
194int udp_lib_getsockopt(struct sock *sk, int level, int optname,
195 char __user *optval, int __user *optlen);
196int udp_lib_setsockopt(struct sock *sk, int level, int optname,
197 char __user *optval, unsigned int optlen,
198 int (*push_pending_frames)(struct sock *));
199struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
200 __be32 daddr, __be16 dport, int dif);
201struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
202 __be32 daddr, __be16 dport, int dif,
203 struct udp_table *tbl);
204struct sock *udp6_lib_lookup(struct net *net,
205 const struct in6_addr *saddr, __be16 sport,
206 const struct in6_addr *daddr, __be16 dport,
207 int dif);
208struct sock *__udp6_lib_lookup(struct net *net,
209 const struct in6_addr *saddr, __be16 sport,
210 const struct in6_addr *daddr, __be16 dport,
211 int dif, struct udp_table *tbl);
212
213/*
214 * SNMP statistics for UDP and UDP-Lite
215 */
216#define UDP_INC_STATS_USER(net, field, is_udplite) do { \
217 if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field); \
218 else SNMP_INC_STATS_USER((net)->mib.udp_statistics, field); } while(0)
219#define UDP_INC_STATS_BH(net, field, is_udplite) do { \
220 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field); \
221 else SNMP_INC_STATS_BH((net)->mib.udp_statistics, field); } while(0)
222
223#define UDP6_INC_STATS_BH(net, field, is_udplite) do { \
224 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\
225 else SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field); \
226} while(0)
227#define UDP6_INC_STATS_USER(net, field, __lite) do { \
228 if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field); \
229 else SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field); \
230} while(0)
231
232#if IS_ENABLED(CONFIG_IPV6)
233#define UDPX_INC_STATS_BH(sk, field) \
234do { \
235 if ((sk)->sk_family == AF_INET) \
236 UDP_INC_STATS_BH(sock_net(sk), field, 0); \
237 else \
238 UDP6_INC_STATS_BH(sock_net(sk), field, 0); \
239} while (0)
240#else
241#define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0)
242#endif
243
244/* /proc */
245int udp_seq_open(struct inode *inode, struct file *file);
246
247struct udp_seq_afinfo {
248 char *name;
249 sa_family_t family;
250 struct udp_table *udp_table;
251 const struct file_operations *seq_fops;
252 struct seq_operations seq_ops;
253};
254
255struct udp_iter_state {
256 struct seq_net_private p;
257 sa_family_t family;
258 int bucket;
259 struct udp_table *udp_table;
260};
261
262#ifdef CONFIG_PROC_FS
263int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);
264void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo);
265
266int udp4_proc_init(void);
267void udp4_proc_exit(void);
268#endif
269
270int udpv4_offload_init(void);
271
272void udp_init(void);
273
274void udp_encap_enable(void);
275#if IS_ENABLED(CONFIG_IPV6)
276void udpv6_encap_enable(void);
277#endif
278#endif /* _UDP_H */