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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 <net/inet_sock.h>
27#include <net/sock.h>
28#include <net/snmp.h>
29#include <net/ip.h>
30#include <linux/ipv6.h>
31#include <linux/seq_file.h>
32#include <linux/poll.h>
33
34/**
35 * struct udp_skb_cb - UDP(-Lite) private variables
36 *
37 * @header: private variables used by IPv4/IPv6
38 * @cscov: checksum coverage length (UDP-Lite only)
39 * @partial_cov: if set indicates partial csum coverage
40 */
41struct udp_skb_cb {
42 union {
43 struct inet_skb_parm h4;
44#if IS_ENABLED(CONFIG_IPV6)
45 struct inet6_skb_parm h6;
46#endif
47 } header;
48 __u16 cscov;
49 __u8 partial_cov;
50};
51#define UDP_SKB_CB(__skb) ((struct udp_skb_cb *)((__skb)->cb))
52
53/**
54 * struct udp_hslot - UDP hash slot
55 *
56 * @head: head of list of sockets
57 * @count: number of sockets in 'head' list
58 * @lock: spinlock protecting changes to head/count
59 */
60struct udp_hslot {
61 struct hlist_nulls_head head;
62 int count;
63 spinlock_t lock;
64} __attribute__((aligned(2 * sizeof(long))));
65
66/**
67 * struct udp_table - UDP table
68 *
69 * @hash: hash table, sockets are hashed on (local port)
70 * @hash2: hash table, sockets are hashed on (local port, local address)
71 * @mask: number of slots in hash tables, minus 1
72 * @log: log2(number of slots in hash table)
73 */
74struct udp_table {
75 struct udp_hslot *hash;
76 struct udp_hslot *hash2;
77 unsigned int mask;
78 unsigned int log;
79};
80extern struct udp_table udp_table;
81extern void udp_table_init(struct udp_table *, const char *);
82static inline struct udp_hslot *udp_hashslot(struct udp_table *table,
83 struct net *net, unsigned num)
84{
85 return &table->hash[udp_hashfn(net, num, table->mask)];
86}
87/*
88 * For secondary hash, net_hash_mix() is performed before calling
89 * udp_hashslot2(), this explains difference with udp_hashslot()
90 */
91static inline struct udp_hslot *udp_hashslot2(struct udp_table *table,
92 unsigned int hash)
93{
94 return &table->hash2[hash & table->mask];
95}
96
97/* Note: this must match 'valbool' in sock_setsockopt */
98#define UDP_CSUM_NOXMIT 1
99
100/* Used by SunRPC/xprt layer. */
101#define UDP_CSUM_NORCV 2
102
103/* Default, as per the RFC, is to always do csums. */
104#define UDP_CSUM_DEFAULT 0
105
106extern struct proto udp_prot;
107
108extern atomic_long_t udp_memory_allocated;
109
110/* sysctl variables for udp */
111extern long sysctl_udp_mem[3];
112extern int sysctl_udp_rmem_min;
113extern int sysctl_udp_wmem_min;
114
115struct sk_buff;
116
117/*
118 * Generic checksumming routines for UDP(-Lite) v4 and v6
119 */
120static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
121{
122 return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov);
123}
124
125static inline int udp_lib_checksum_complete(struct sk_buff *skb)
126{
127 return !skb_csum_unnecessary(skb) &&
128 __udp_lib_checksum_complete(skb);
129}
130
131/**
132 * udp_csum_outgoing - compute UDPv4/v6 checksum over fragments
133 * @sk: socket we are writing to
134 * @skb: sk_buff containing the filled-in UDP header
135 * (checksum field must be zeroed out)
136 */
137static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
138{
139 __wsum csum = csum_partial(skb_transport_header(skb),
140 sizeof(struct udphdr), 0);
141 skb_queue_walk(&sk->sk_write_queue, skb) {
142 csum = csum_add(csum, skb->csum);
143 }
144 return csum;
145}
146
147static inline __wsum udp_csum(struct sk_buff *skb)
148{
149 __wsum csum = csum_partial(skb_transport_header(skb),
150 sizeof(struct udphdr), skb->csum);
151
152 for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) {
153 csum = csum_add(csum, skb->csum);
154 }
155 return csum;
156}
157
158/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
159static inline void udp_lib_hash(struct sock *sk)
160{
161 BUG();
162}
163
164extern void udp_lib_unhash(struct sock *sk);
165extern void udp_lib_rehash(struct sock *sk, u16 new_hash);
166
167static inline void udp_lib_close(struct sock *sk, long timeout)
168{
169 sk_common_release(sk);
170}
171
172extern int udp_lib_get_port(struct sock *sk, unsigned short snum,
173 int (*)(const struct sock *,const struct sock *),
174 unsigned int hash2_nulladdr);
175
176/* net/ipv4/udp.c */
177extern int udp_get_port(struct sock *sk, unsigned short snum,
178 int (*saddr_cmp)(const struct sock *,
179 const struct sock *));
180extern void udp_err(struct sk_buff *, u32);
181extern int udp_sendmsg(struct kiocb *iocb, struct sock *sk,
182 struct msghdr *msg, size_t len);
183extern void udp_flush_pending_frames(struct sock *sk);
184extern int udp_rcv(struct sk_buff *skb);
185extern int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
186extern int udp_disconnect(struct sock *sk, int flags);
187extern unsigned int udp_poll(struct file *file, struct socket *sock,
188 poll_table *wait);
189extern int udp_lib_getsockopt(struct sock *sk, int level, int optname,
190 char __user *optval, int __user *optlen);
191extern int udp_lib_setsockopt(struct sock *sk, int level, int optname,
192 char __user *optval, unsigned int optlen,
193 int (*push_pending_frames)(struct sock *));
194extern struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
195 __be32 daddr, __be16 dport,
196 int dif);
197extern struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
198 __be32 daddr, __be16 dport,
199 int dif, struct udp_table *tbl);
200extern struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
201 const struct in6_addr *daddr, __be16 dport,
202 int dif);
203extern struct sock *__udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
204 const struct in6_addr *daddr, __be16 dport,
205 int dif, struct udp_table *tbl);
206
207/*
208 * SNMP statistics for UDP and UDP-Lite
209 */
210#define UDP_INC_STATS_USER(net, field, is_udplite) do { \
211 if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field); \
212 else SNMP_INC_STATS_USER((net)->mib.udp_statistics, field); } while(0)
213#define UDP_INC_STATS_BH(net, field, is_udplite) do { \
214 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field); \
215 else SNMP_INC_STATS_BH((net)->mib.udp_statistics, field); } while(0)
216
217#define UDP6_INC_STATS_BH(net, field, is_udplite) do { \
218 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\
219 else SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field); \
220} while(0)
221#define UDP6_INC_STATS_USER(net, field, __lite) do { \
222 if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field); \
223 else SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field); \
224} while(0)
225
226#if IS_ENABLED(CONFIG_IPV6)
227#define UDPX_INC_STATS_BH(sk, field) \
228 do { \
229 if ((sk)->sk_family == AF_INET) \
230 UDP_INC_STATS_BH(sock_net(sk), field, 0); \
231 else \
232 UDP6_INC_STATS_BH(sock_net(sk), field, 0); \
233 } while (0);
234#else
235#define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0)
236#endif
237
238/* /proc */
239int udp_seq_open(struct inode *inode, struct file *file);
240
241struct udp_seq_afinfo {
242 char *name;
243 sa_family_t family;
244 struct udp_table *udp_table;
245 const struct file_operations *seq_fops;
246 struct seq_operations seq_ops;
247};
248
249struct udp_iter_state {
250 struct seq_net_private p;
251 sa_family_t family;
252 int bucket;
253 struct udp_table *udp_table;
254};
255
256#ifdef CONFIG_PROC_FS
257extern int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);
258extern void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo);
259
260extern int udp4_proc_init(void);
261extern void udp4_proc_exit(void);
262#endif
263
264extern void udp_init(void);
265
266extern int udp4_ufo_send_check(struct sk_buff *skb);
267extern struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
268 netdev_features_t features);
269#endif /* _UDP_H */