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CommitLineData
1da177e4
LT
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 *
02c30a84 10 * Authors: Ross Biro
1da177e4
LT
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
1da177e4 25#include <linux/list.h>
187f1882 26#include <linux/bug.h>
14c85021 27#include <net/inet_sock.h>
1da177e4
LT
28#include <net/sock.h>
29#include <net/snmp.h>
ba4e58ec
GR
30#include <net/ip.h>
31#include <linux/ipv6.h>
1da177e4 32#include <linux/seq_file.h>
bd01f843 33#include <linux/poll.h>
1da177e4 34
ba4e58ec
GR
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;
dfd56b8b 45#if IS_ENABLED(CONFIG_IPV6)
ba4e58ec
GR
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))
1da177e4 53
fdcc8aa9
ED
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 */
645ca708 61struct udp_hslot {
ca065d0c 62 struct hlist_head head;
fdcc8aa9 63 int count;
645ca708
ED
64 spinlock_t lock;
65} __attribute__((aligned(2 * sizeof(long))));
f86dcc5a 66
512615b6
ED
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 */
645ca708 75struct udp_table {
f86dcc5a 76 struct udp_hslot *hash;
512615b6
ED
77 struct udp_hslot *hash2;
78 unsigned int mask;
79 unsigned int log;
645ca708
ED
80};
81extern struct udp_table udp_table;
1a50bd06 82void udp_table_init(struct udp_table *, const char *);
f86dcc5a 83static inline struct udp_hslot *udp_hashslot(struct udp_table *table,
95c96174 84 struct net *net, unsigned int num)
f86dcc5a
ED
85{
86 return &table->hash[udp_hashfn(net, num, table->mask)];
87}
512615b6
ED
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}
1da177e4 97
1da177e4
LT
98extern struct proto udp_prot;
99
8d987e5c 100extern atomic_long_t udp_memory_allocated;
95766fff
HA
101
102/* sysctl variables for udp */
8d987e5c 103extern long sysctl_udp_mem[3];
95766fff
HA
104extern int sysctl_udp_rmem_min;
105extern int sysctl_udp_wmem_min;
106
14c85021 107struct sk_buff;
1da177e4 108
ba4e58ec
GR
109/*
110 * Generic checksumming routines for UDP(-Lite) v4 and v6
111 */
b51655b9 112static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
ba4e58ec 113{
bbdff225
TH
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));
ba4e58ec
GR
117}
118
8e5200f5 119static inline int udp_lib_checksum_complete(struct sk_buff *skb)
ba4e58ec 120{
60476372 121 return !skb_csum_unnecessary(skb) &&
ba4e58ec
GR
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 */
868c86bc 131static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
ba4e58ec 132{
9c70220b
ACM
133 __wsum csum = csum_partial(skb_transport_header(skb),
134 sizeof(struct udphdr), 0);
ba4e58ec
GR
135 skb_queue_walk(&sk->sk_write_queue, skb) {
136 csum = csum_add(csum, skb->csum);
137 }
138 return csum;
139}
140
f6b9664f
HX
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
af5fcba7
TH
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
e6afc8ac 161static inline void udp_csum_pull_header(struct sk_buff *skb)
162{
595d0b29
ED
163 if (!skb->csum_valid && skb->ip_summed == CHECKSUM_NONE)
164 skb->csum = csum_partial(skb->data, sizeof(struct udphdr),
e6afc8ac 165 skb->csum);
166 skb_pull_rcsum(skb, sizeof(struct udphdr));
167 UDP_SKB_CB(skb)->cscov -= sizeof(struct udphdr);
168}
169
a6024562
TH
170typedef struct sock *(*udp_lookup_t)(struct sk_buff *skb, __be16 sport,
171 __be16 dport);
172
57c67ff4 173struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb,
a6024562
TH
174 struct udphdr *uh, udp_lookup_t lookup);
175int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup);
57c67ff4
TH
176
177static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb)
178{
179 struct udphdr *uh;
180 unsigned int hlen, off;
181
182 off = skb_gro_offset(skb);
183 hlen = off + sizeof(*uh);
184 uh = skb_gro_header_fast(skb, off);
185 if (skb_gro_header_hard(skb, hlen))
186 uh = skb_gro_header_slow(skb, hlen, off);
187
188 return uh;
189}
190
ba4e58ec 191/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
086c653f 192static inline int udp_lib_hash(struct sock *sk)
ba4e58ec
GR
193{
194 BUG();
086c653f 195 return 0;
ba4e58ec
GR
196}
197
1a50bd06
JP
198void udp_lib_unhash(struct sock *sk);
199void udp_lib_rehash(struct sock *sk, u16 new_hash);
ba4e58ec
GR
200
201static inline void udp_lib_close(struct sock *sk, long timeout)
202{
203 sk_common_release(sk);
204}
205
1a50bd06 206int udp_lib_get_port(struct sock *sk, unsigned short snum,
1a50bd06 207 unsigned int hash2_nulladdr);
ba4e58ec 208
723b8e46
TH
209u32 udp_flow_hashrnd(void);
210
b8f1a556
TH
211static inline __be16 udp_flow_src_port(struct net *net, struct sk_buff *skb,
212 int min, int max, bool use_eth)
213{
214 u32 hash;
215
216 if (min >= max) {
217 /* Use default range */
218 inet_get_local_port_range(net, &min, &max);
219 }
220
221 hash = skb_get_hash(skb);
723b8e46
TH
222 if (unlikely(!hash)) {
223 if (use_eth) {
224 /* Can't find a normal hash, caller has indicated an
225 * Ethernet packet so use that to compute a hash.
226 */
227 hash = jhash(skb->data, 2 * ETH_ALEN,
228 (__force u32) skb->protocol);
229 } else {
230 /* Can't derive any sort of hash for the packet, set
231 * to some consistent random value.
232 */
233 hash = udp_flow_hashrnd();
234 }
b8f1a556
TH
235 }
236
237 /* Since this is being sent on the wire obfuscate hash a bit
238 * to minimize possbility that any useful information to an
239 * attacker is leaked. Only upper 16 bits are relevant in the
240 * computation for 16 bit port value.
241 */
242 hash ^= hash << 16;
243
244 return htons((((u64) hash * (max - min)) >> 32) + min);
245}
246
8b4099ff
PA
247static inline int udp_rqueue_get(struct sock *sk)
248{
249 return sk_rmem_alloc_get(sk) - READ_ONCE(udp_sk(sk)->forward_deficit);
250}
251
ba4e58ec 252/* net/ipv4/udp.c */
c915fe13 253void udp_destruct_sock(struct sock *sk);
f970bd9e
PA
254void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len);
255int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb);
7c13f97f 256void udp_skb_destructor(struct sock *sk, struct sk_buff *skb);
2276f58a
PA
257struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
258 int noblock, int *peeked, int *off, int *err);
7c13f97f
PA
259static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags,
260 int noblock, int *err)
261{
262 int peeked, off = 0;
263
264 return __skb_recv_udp(sk, flags, noblock, &peeked, &off, err);
265}
f970bd9e 266
7487449c 267int udp_v4_early_demux(struct sk_buff *skb);
64f0f5d1 268bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst);
1a50bd06
JP
269int udp_get_port(struct sock *sk, unsigned short snum,
270 int (*saddr_cmp)(const struct sock *,
271 const struct sock *));
272void udp_err(struct sk_buff *, u32);
5d77dca8 273int udp_abort(struct sock *sk, int err);
1b784140 274int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len);
1a50bd06
JP
275int udp_push_pending_frames(struct sock *sk);
276void udp_flush_pending_frames(struct sock *sk);
277void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst);
278int udp_rcv(struct sk_buff *skb);
279int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
f970bd9e 280int udp_init_sock(struct sock *sk);
286c72de 281int __udp_disconnect(struct sock *sk, int flags);
1a50bd06
JP
282int udp_disconnect(struct sock *sk, int flags);
283unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait);
284struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
8bce6d7d
TH
285 netdev_features_t features,
286 bool is_ipv6);
1a50bd06
JP
287int udp_lib_getsockopt(struct sock *sk, int level, int optname,
288 char __user *optval, int __user *optlen);
289int udp_lib_setsockopt(struct sock *sk, int level, int optname,
290 char __user *optval, unsigned int optlen,
291 int (*push_pending_frames)(struct sock *));
292struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
293 __be32 daddr, __be16 dport, int dif);
294struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
fb74c277 295 __be32 daddr, __be16 dport, int dif, int sdif,
538950a1 296 struct udp_table *tbl, struct sk_buff *skb);
63058308
TH
297struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
298 __be16 sport, __be16 dport);
1a50bd06
JP
299struct sock *udp6_lib_lookup(struct net *net,
300 const struct in6_addr *saddr, __be16 sport,
301 const struct in6_addr *daddr, __be16 dport,
302 int dif);
303struct sock *__udp6_lib_lookup(struct net *net,
304 const struct in6_addr *saddr, __be16 sport,
305 const struct in6_addr *daddr, __be16 dport,
1801b570 306 int dif, int sdif, struct udp_table *tbl,
538950a1 307 struct sk_buff *skb);
63058308
TH
308struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
309 __be16 sport, __be16 dport);
bcd41303 310
b26bbdae
PA
311/* UDP uses skb->dev_scratch to cache as much information as possible and avoid
312 * possibly multiple cache miss on dequeue()
313 */
b26bbdae 314struct udp_dev_scratch {
dce4551c
PA
315 /* skb->truesize and the stateless bit are embedded in a single field;
316 * do not use a bitfield since the compiler emits better/smaller code
317 * this way
318 */
319 u32 _tsize_state;
320
321#if BITS_PER_LONG == 64
322 /* len and the bit needed to compute skb_csum_unnecessary
323 * will be on cold cache lines at recvmsg time.
324 * skb->len can be stored on 16 bits since the udp header has been
325 * already validated and pulled.
326 */
b26bbdae
PA
327 u16 len;
328 bool is_linear;
329 bool csum_unnecessary;
dce4551c 330#endif
b26bbdae
PA
331};
332
dce4551c
PA
333static inline struct udp_dev_scratch *udp_skb_scratch(struct sk_buff *skb)
334{
335 return (struct udp_dev_scratch *)&skb->dev_scratch;
336}
337
338#if BITS_PER_LONG == 64
b26bbdae
PA
339static inline unsigned int udp_skb_len(struct sk_buff *skb)
340{
dce4551c 341 return udp_skb_scratch(skb)->len;
b26bbdae
PA
342}
343
344static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)
345{
dce4551c 346 return udp_skb_scratch(skb)->csum_unnecessary;
b26bbdae
PA
347}
348
349static inline bool udp_skb_is_linear(struct sk_buff *skb)
350{
dce4551c 351 return udp_skb_scratch(skb)->is_linear;
b26bbdae
PA
352}
353
354#else
355static inline unsigned int udp_skb_len(struct sk_buff *skb)
356{
357 return skb->len;
358}
359
360static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)
361{
362 return skb_csum_unnecessary(skb);
363}
364
365static inline bool udp_skb_is_linear(struct sk_buff *skb)
366{
367 return !skb_is_nonlinear(skb);
368}
369#endif
370
371static inline int copy_linear_skb(struct sk_buff *skb, int len, int off,
372 struct iov_iter *to)
373{
42b73059 374 int n;
b26bbdae 375
42b73059
AV
376 n = copy_to_iter(skb->data + off, len, to);
377 if (n == len)
b26bbdae
PA
378 return 0;
379
42b73059 380 iov_iter_revert(to, n);
b26bbdae
PA
381 return -EFAULT;
382}
383
ba4e58ec
GR
384/*
385 * SNMP statistics for UDP and UDP-Lite
386 */
6aef70a8
ED
387#define UDP_INC_STATS(net, field, is_udplite) do { \
388 if (is_udplite) SNMP_INC_STATS((net)->mib.udplite_statistics, field); \
389 else SNMP_INC_STATS((net)->mib.udp_statistics, field); } while(0)
02c22347 390#define __UDP_INC_STATS(net, field, is_udplite) do { \
13415e46
ED
391 if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_statistics, field); \
392 else __SNMP_INC_STATS((net)->mib.udp_statistics, field); } while(0)
1da177e4 393
02c22347 394#define __UDP6_INC_STATS(net, field, is_udplite) do { \
13415e46
ED
395 if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_stats_in6, field);\
396 else __SNMP_INC_STATS((net)->mib.udp_stats_in6, field); \
0c7ed677 397} while(0)
6aef70a8
ED
398#define UDP6_INC_STATS(net, field, __lite) do { \
399 if (__lite) SNMP_INC_STATS((net)->mib.udplite_stats_in6, field); \
400 else SNMP_INC_STATS((net)->mib.udp_stats_in6, field); \
0c7ed677 401} while(0)
1781f7f5 402
dfd56b8b 403#if IS_ENABLED(CONFIG_IPV6)
02c22347 404#define __UDPX_INC_STATS(sk, field) \
f9bddcdf
JP
405do { \
406 if ((sk)->sk_family == AF_INET) \
02c22347 407 __UDP_INC_STATS(sock_net(sk), field, 0); \
f9bddcdf 408 else \
02c22347 409 __UDP6_INC_STATS(sock_net(sk), field, 0); \
f9bddcdf 410} while (0)
1781f7f5 411#else
02c22347 412#define __UDPX_INC_STATS(sk, field) __UDP_INC_STATS(sock_net(sk), field, 0)
1781f7f5
HX
413#endif
414
1da177e4 415/* /proc */
73cb88ec
AV
416int udp_seq_open(struct inode *inode, struct file *file);
417
1da177e4 418struct udp_seq_afinfo {
73cb88ec
AV
419 char *name;
420 sa_family_t family;
421 struct udp_table *udp_table;
422 const struct file_operations *seq_fops;
423 struct seq_operations seq_ops;
1da177e4
LT
424};
425
426struct udp_iter_state {
6f191efe 427 struct seq_net_private p;
1da177e4
LT
428 sa_family_t family;
429 int bucket;
645ca708 430 struct udp_table *udp_table;
1da177e4
LT
431};
432
20380731 433#ifdef CONFIG_PROC_FS
1a50bd06
JP
434int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);
435void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo);
20380731 436
1a50bd06
JP
437int udp4_proc_init(void);
438void udp4_proc_exit(void);
20380731 439#endif
95766fff 440
1a50bd06 441int udpv4_offload_init(void);
da5bab07 442
1a50bd06 443void udp_init(void);
d7ca4cc0 444
1a50bd06 445void udp_encap_enable(void);
d7f3f621 446#if IS_ENABLED(CONFIG_IPV6)
1a50bd06 447void udpv6_encap_enable(void);
d7f3f621 448#endif
dddb64bc 449
1da177e4 450#endif /* _UDP_H */