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 */
42 struct 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 */
61 struct 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 */
75 struct udp_table {
76 struct udp_hslot *hash;
77 struct udp_hslot *hash2;
78 unsigned int mask;
79 unsigned int log;
80 };
81 extern struct udp_table udp_table;
82 extern void udp_table_init(struct udp_table *, const char *);
udp_hashslot(struct udp_table * table,struct net * net,unsigned num)83 static inline struct udp_hslot *udp_hashslot(struct udp_table *table,
84 struct net *net, unsigned 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 */
udp_hashslot2(struct udp_table * table,unsigned int hash)92 static 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
107 extern struct proto udp_prot;
108
109 extern atomic_long_t udp_memory_allocated;
110
111 /* sysctl variables for udp */
112 extern long sysctl_udp_mem[3];
113 extern int sysctl_udp_rmem_min;
114 extern int sysctl_udp_wmem_min;
115
116 struct sk_buff;
117
118 /*
119 * Generic checksumming routines for UDP(-Lite) v4 and v6
120 */
__udp_lib_checksum_complete(struct sk_buff * skb)121 static 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
udp_lib_checksum_complete(struct sk_buff * skb)126 static 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 */
udp_csum_outgoing(struct sock * sk,struct sk_buff * skb)138 static 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
udp_csum(struct sk_buff * skb)148 static 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 */
udp_lib_hash(struct sock * sk)160 static inline void udp_lib_hash(struct sock *sk)
161 {
162 BUG();
163 }
164
165 extern void udp_lib_unhash(struct sock *sk);
166 extern void udp_lib_rehash(struct sock *sk, u16 new_hash);
167
udp_lib_close(struct sock * sk,long timeout)168 static inline void udp_lib_close(struct sock *sk, long timeout)
169 {
170 sk_common_release(sk);
171 }
172
173 extern int 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 */
178 extern int udp_get_port(struct sock *sk, unsigned short snum,
179 int (*saddr_cmp)(const struct sock *,
180 const struct sock *));
181 extern void udp_err(struct sk_buff *, u32);
182 extern int udp_sendmsg(struct kiocb *iocb, struct sock *sk,
183 struct msghdr *msg, size_t len);
184 extern int udp_push_pending_frames(struct sock *sk);
185 extern void udp_flush_pending_frames(struct sock *sk);
186 extern int udp_rcv(struct sk_buff *skb);
187 extern int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
188 extern int udp_disconnect(struct sock *sk, int flags);
189 extern unsigned int udp_poll(struct file *file, struct socket *sock,
190 poll_table *wait);
191 extern int udp_lib_getsockopt(struct sock *sk, int level, int optname,
192 char __user *optval, int __user *optlen);
193 extern int udp_lib_setsockopt(struct sock *sk, int level, int optname,
194 char __user *optval, unsigned int optlen,
195 int (*push_pending_frames)(struct sock *));
196 extern struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
197 __be32 daddr, __be16 dport,
198 int dif);
199 extern struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
200 __be32 daddr, __be16 dport,
201 int dif, struct udp_table *tbl);
202 extern struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
203 const struct in6_addr *daddr, __be16 dport,
204 int dif);
205 extern struct sock *__udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
206 const struct in6_addr *daddr, __be16 dport,
207 int dif, struct udp_table *tbl);
208
209 /*
210 * SNMP statistics for UDP and UDP-Lite
211 */
212 #define UDP_INC_STATS_USER(net, field, is_udplite) do { \
213 if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field); \
214 else SNMP_INC_STATS_USER((net)->mib.udp_statistics, field); } while(0)
215 #define UDP_INC_STATS_BH(net, field, is_udplite) do { \
216 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field); \
217 else SNMP_INC_STATS_BH((net)->mib.udp_statistics, field); } while(0)
218
219 #define UDP6_INC_STATS_BH(net, field, is_udplite) do { \
220 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\
221 else SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field); \
222 } while(0)
223 #define UDP6_INC_STATS_USER(net, field, __lite) do { \
224 if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field); \
225 else SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field); \
226 } while(0)
227
228 #if IS_ENABLED(CONFIG_IPV6)
229 #define UDPX_INC_STATS_BH(sk, field) \
230 do { \
231 if ((sk)->sk_family == AF_INET) \
232 UDP_INC_STATS_BH(sock_net(sk), field, 0); \
233 else \
234 UDP6_INC_STATS_BH(sock_net(sk), field, 0); \
235 } while (0);
236 #else
237 #define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0)
238 #endif
239
240 /* /proc */
241 int udp_seq_open(struct inode *inode, struct file *file);
242
243 struct udp_seq_afinfo {
244 char *name;
245 sa_family_t family;
246 struct udp_table *udp_table;
247 const struct file_operations *seq_fops;
248 struct seq_operations seq_ops;
249 };
250
251 struct udp_iter_state {
252 struct seq_net_private p;
253 sa_family_t family;
254 int bucket;
255 struct udp_table *udp_table;
256 };
257
258 #ifdef CONFIG_PROC_FS
259 extern int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);
260 extern void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo);
261
262 extern int udp4_proc_init(void);
263 extern void udp4_proc_exit(void);
264 #endif
265
266 extern void udp_init(void);
267
268 extern int udp4_ufo_send_check(struct sk_buff *skb);
269 extern struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
270 netdev_features_t features);
271 #endif /* _UDP_H */
272