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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 *
Jesper Juhl02c30a82005-05-05 16:16:16 -070010 * Authors: Ross Biro
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/list.h>
Paul Gortmaker187f1882011-11-23 20:12:59 -050026#include <linux/bug.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020027#include <net/inet_sock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <net/sock.h>
29#include <net/snmp.h>
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080030#include <net/ip.h>
31#include <linux/ipv6.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/seq_file.h>
Al Virobd01f842006-10-19 17:23:57 -040033#include <linux/poll.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080035/**
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;
Eric Dumazetdfd56b82011-12-10 09:48:31 +000045#if IS_ENABLED(CONFIG_IPV6)
Gerrit Renkerba4e58e2006-11-27 11:10:57 -080046 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))
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
Eric Dumazetfdcc8aa92009-11-08 10:17:05 +000054/**
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 */
Eric Dumazet645ca702008-10-29 01:41:45 -070061struct udp_hslot {
Eric Dumazet88ab1932008-11-16 19:39:21 -080062 struct hlist_nulls_head head;
Eric Dumazetfdcc8aa92009-11-08 10:17:05 +000063 int count;
Eric Dumazet645ca702008-10-29 01:41:45 -070064 spinlock_t lock;
65} __attribute__((aligned(2 * sizeof(long))));
Eric Dumazetf86dcc52009-10-07 00:37:59 +000066
Eric Dumazet512615b2009-11-08 10:17:58 +000067/**
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 */
Eric Dumazet645ca702008-10-29 01:41:45 -070075struct udp_table {
Eric Dumazetf86dcc52009-10-07 00:37:59 +000076 struct udp_hslot *hash;
Eric Dumazet512615b2009-11-08 10:17:58 +000077 struct udp_hslot *hash2;
78 unsigned int mask;
79 unsigned int log;
Eric Dumazet645ca702008-10-29 01:41:45 -070080};
81extern struct udp_table udp_table;
Joe Perches1a50bd02013-09-23 11:33:36 -070082void udp_table_init(struct udp_table *, const char *);
Eric Dumazetf86dcc52009-10-07 00:37:59 +000083static inline struct udp_hslot *udp_hashslot(struct udp_table *table,
Eric Dumazet95c96172012-04-15 05:58:06 +000084 struct net *net, unsigned int num)
Eric Dumazetf86dcc52009-10-07 00:37:59 +000085{
86 return &table->hash[udp_hashfn(net, num, table->mask)];
87}
Eric Dumazet512615b2009-11-08 10:17:58 +000088/*
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}
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Linus Torvalds1da177e2005-04-16 15:20:36 -070098extern struct proto udp_prot;
99
Eric Dumazet8d987e52010-11-09 23:24:26 +0000100extern atomic_long_t udp_memory_allocated;
Hideo Aoki95766ff2007-12-31 00:29:24 -0800101
102/* sysctl variables for udp */
Eric Dumazet8d987e52010-11-09 23:24:26 +0000103extern long sysctl_udp_mem[3];
Hideo Aoki95766ff2007-12-31 00:29:24 -0800104extern int sysctl_udp_rmem_min;
105extern int sysctl_udp_wmem_min;
106
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -0200107struct sk_buff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800109/*
110 * Generic checksumming routines for UDP(-Lite) v4 and v6
111 */
Al Virob51655b2006-11-14 21:40:42 -0800112static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800113{
Tom Herbertbbdff222014-06-14 23:24:20 -0700114 return (UDP_SKB_CB(skb)->cscov == skb->len ?
115 __skb_checksum_complete(skb) :
116 __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov));
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800117}
118
Al Viro8e5200f2006-11-20 18:06:37 -0800119static inline int udp_lib_checksum_complete(struct sk_buff *skb)
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800120{
Herbert Xu60476372007-04-09 11:59:39 -0700121 return !skb_csum_unnecessary(skb) &&
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800122 __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 */
Al Viro868c86b2006-11-14 21:35:48 -0800131static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800132{
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -0700133 __wsum csum = csum_partial(skb_transport_header(skb),
134 sizeof(struct udphdr), 0);
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800135 skb_queue_walk(&sk->sk_write_queue, skb) {
136 csum = csum_add(csum, skb->csum);
137 }
138 return csum;
139}
140
Herbert Xuf6b96642011-03-01 02:36:48 +0000141static 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
Tom Herbertaf5fcba2014-06-04 17:19:48 -0700152static 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
Tom Herbert57c67ff2014-08-22 13:34:44 -0700161struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb,
162 struct udphdr *uh);
163int udp_gro_complete(struct sk_buff *skb, int nhoff);
164
165static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb)
166{
167 struct udphdr *uh;
168 unsigned int hlen, off;
169
170 off = skb_gro_offset(skb);
171 hlen = off + sizeof(*uh);
172 uh = skb_gro_header_fast(skb, off);
173 if (skb_gro_header_hard(skb, hlen))
174 uh = skb_gro_header_slow(skb, hlen, off);
175
176 return uh;
177}
178
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800179/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
180static inline void udp_lib_hash(struct sock *sk)
181{
182 BUG();
183}
184
Joe Perches1a50bd02013-09-23 11:33:36 -0700185void udp_lib_unhash(struct sock *sk);
186void udp_lib_rehash(struct sock *sk, u16 new_hash);
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800187
188static inline void udp_lib_close(struct sock *sk, long timeout)
189{
190 sk_common_release(sk);
191}
192
Joe Perches1a50bd02013-09-23 11:33:36 -0700193int udp_lib_get_port(struct sock *sk, unsigned short snum,
194 int (*)(const struct sock *, const struct sock *),
195 unsigned int hash2_nulladdr);
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800196
Tom Herbert723b8e42015-02-24 09:17:31 -0800197u32 udp_flow_hashrnd(void);
198
Tom Herbertb8f1a552014-07-01 21:32:39 -0700199static inline __be16 udp_flow_src_port(struct net *net, struct sk_buff *skb,
200 int min, int max, bool use_eth)
201{
202 u32 hash;
203
204 if (min >= max) {
205 /* Use default range */
206 inet_get_local_port_range(net, &min, &max);
207 }
208
209 hash = skb_get_hash(skb);
Tom Herbert723b8e42015-02-24 09:17:31 -0800210 if (unlikely(!hash)) {
211 if (use_eth) {
212 /* Can't find a normal hash, caller has indicated an
213 * Ethernet packet so use that to compute a hash.
214 */
215 hash = jhash(skb->data, 2 * ETH_ALEN,
216 (__force u32) skb->protocol);
217 } else {
218 /* Can't derive any sort of hash for the packet, set
219 * to some consistent random value.
220 */
221 hash = udp_flow_hashrnd();
222 }
Tom Herbertb8f1a552014-07-01 21:32:39 -0700223 }
224
225 /* Since this is being sent on the wire obfuscate hash a bit
226 * to minimize possbility that any useful information to an
227 * attacker is leaked. Only upper 16 bits are relevant in the
228 * computation for 16 bit port value.
229 */
230 hash ^= hash << 16;
231
232 return htons((((u64) hash * (max - min)) >> 32) + min);
233}
234
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800235/* net/ipv4/udp.c */
Shawn Bohrer421b3882013-10-07 11:01:39 -0500236void udp_v4_early_demux(struct sk_buff *skb);
Joe Perches1a50bd02013-09-23 11:33:36 -0700237int udp_get_port(struct sock *sk, unsigned short snum,
238 int (*saddr_cmp)(const struct sock *,
239 const struct sock *));
240void udp_err(struct sk_buff *, u32);
Ying Xue1b784142015-03-02 15:37:48 +0800241int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len);
Joe Perches1a50bd02013-09-23 11:33:36 -0700242int udp_push_pending_frames(struct sock *sk);
243void udp_flush_pending_frames(struct sock *sk);
244void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst);
245int udp_rcv(struct sk_buff *skb);
246int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
247int udp_disconnect(struct sock *sk, int flags);
248unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait);
249struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
Tom Herbert8bce6d72014-09-29 20:22:29 -0700250 netdev_features_t features,
251 bool is_ipv6);
Joe Perches1a50bd02013-09-23 11:33:36 -0700252int udp_lib_getsockopt(struct sock *sk, int level, int optname,
253 char __user *optval, int __user *optlen);
254int udp_lib_setsockopt(struct sock *sk, int level, int optname,
255 char __user *optval, unsigned int optlen,
256 int (*push_pending_frames)(struct sock *));
257struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
258 __be32 daddr, __be16 dport, int dif);
259struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
260 __be32 daddr, __be16 dport, int dif,
261 struct udp_table *tbl);
262struct sock *udp6_lib_lookup(struct net *net,
263 const struct in6_addr *saddr, __be16 sport,
264 const struct in6_addr *daddr, __be16 dport,
265 int dif);
266struct sock *__udp6_lib_lookup(struct net *net,
267 const struct in6_addr *saddr, __be16 sport,
268 const struct in6_addr *daddr, __be16 dport,
269 int dif, struct udp_table *tbl);
KOVACS Krisztianbcd41302008-10-01 07:48:10 -0700270
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800271/*
272 * SNMP statistics for UDP and UDP-Lite
273 */
Pavel Emelyanov2f275f92008-07-18 04:03:27 -0700274#define UDP_INC_STATS_USER(net, field, is_udplite) do { \
Pavel Emelyanov386019d2008-07-18 04:03:45 -0700275 if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field); \
Pavel Emelyanov2f275f92008-07-18 04:03:27 -0700276 else SNMP_INC_STATS_USER((net)->mib.udp_statistics, field); } while(0)
277#define UDP_INC_STATS_BH(net, field, is_udplite) do { \
Pavel Emelyanov386019d2008-07-18 04:03:45 -0700278 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field); \
Pavel Emelyanov2f275f92008-07-18 04:03:27 -0700279 else SNMP_INC_STATS_BH((net)->mib.udp_statistics, field); } while(0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280
Denis V. Lunev0c7ed672008-10-07 14:49:36 -0700281#define UDP6_INC_STATS_BH(net, field, is_udplite) do { \
Denis V. Lunevbe713a42008-10-07 14:50:06 -0700282 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\
Denis V. Lunev0c7ed672008-10-07 14:49:36 -0700283 else SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field); \
284} while(0)
Denis V. Lunevbe713a42008-10-07 14:50:06 -0700285#define UDP6_INC_STATS_USER(net, field, __lite) do { \
286 if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field); \
287 else SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field); \
Denis V. Lunev0c7ed672008-10-07 14:49:36 -0700288} while(0)
Herbert Xu1781f7f2007-12-11 11:30:32 -0800289
Eric Dumazetdfd56b82011-12-10 09:48:31 +0000290#if IS_ENABLED(CONFIG_IPV6)
Joe Perchesf9bddcd2013-11-05 14:13:47 -0800291#define UDPX_INC_STATS_BH(sk, field) \
292do { \
293 if ((sk)->sk_family == AF_INET) \
294 UDP_INC_STATS_BH(sock_net(sk), field, 0); \
295 else \
296 UDP6_INC_STATS_BH(sock_net(sk), field, 0); \
297} while (0)
Herbert Xu1781f7f2007-12-11 11:30:32 -0800298#else
Pavel Emelyanov02833282008-07-05 21:18:48 -0700299#define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0)
Herbert Xu1781f7f2007-12-11 11:30:32 -0800300#endif
301
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302/* /proc */
Arjan van de Ven73cb88e2011-10-30 06:46:30 +0000303int udp_seq_open(struct inode *inode, struct file *file);
304
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305struct udp_seq_afinfo {
Arjan van de Ven73cb88e2011-10-30 06:46:30 +0000306 char *name;
307 sa_family_t family;
308 struct udp_table *udp_table;
309 const struct file_operations *seq_fops;
310 struct seq_operations seq_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311};
312
313struct udp_iter_state {
Denis V. Lunev6f191ef2008-03-28 18:23:33 -0700314 struct seq_net_private p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 sa_family_t family;
316 int bucket;
Eric Dumazet645ca702008-10-29 01:41:45 -0700317 struct udp_table *udp_table;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318};
319
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -0300320#ifdef CONFIG_PROC_FS
Joe Perches1a50bd02013-09-23 11:33:36 -0700321int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);
322void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo);
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -0300323
Joe Perches1a50bd02013-09-23 11:33:36 -0700324int udp4_proc_init(void);
325void udp4_proc_exit(void);
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -0300326#endif
Hideo Aoki95766ff2007-12-31 00:29:24 -0800327
Joe Perches1a50bd02013-09-23 11:33:36 -0700328int udpv4_offload_init(void);
Daniel Borkmannda5bab02013-06-08 12:56:03 +0200329
Joe Perches1a50bd02013-09-23 11:33:36 -0700330void udp_init(void);
Sridhar Samudralad7ca4cc2009-07-09 08:09:47 +0000331
Joe Perches1a50bd02013-09-23 11:33:36 -0700332void udp_encap_enable(void);
Benjamin LaHaised7f3f622012-04-27 08:24:08 +0000333#if IS_ENABLED(CONFIG_IPV6)
Joe Perches1a50bd02013-09-23 11:33:36 -0700334void udpv6_encap_enable(void);
Benjamin LaHaised7f3f622012-04-27 08:24:08 +0000335#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336#endif /* _UDP_H */