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 | } ; |
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_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 | void udp_table_init(struct udp_table *, const char *); |
83 | static 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 | */ |
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 | extern struct proto udp_prot; |
99 | |
100 | extern atomic_long_t udp_memory_allocated; |
101 | |
102 | /* sysctl variables for udp */ |
103 | extern long sysctl_udp_mem[3]; |
104 | extern int sysctl_udp_rmem_min; |
105 | extern int sysctl_udp_wmem_min; |
106 | |
107 | struct sk_buff; |
108 | |
109 | /* |
110 | * Generic checksumming routines for UDP(-Lite) v4 and v6 |
111 | */ |
112 | static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb) |
113 | { |
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)); |
117 | } |
118 | |
119 | static inline int udp_lib_checksum_complete(struct sk_buff *skb) |
120 | { |
121 | return !skb_csum_unnecessary(skb) && |
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 | */ |
131 | static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb) |
132 | { |
133 | __wsum csum = csum_partial(skb_transport_header(skb), |
134 | sizeof(struct udphdr), 0); |
135 | skb_queue_walk(&sk->sk_write_queue, skb) { |
136 | csum = csum_add(csum, skb->csum); |
137 | } |
138 | return csum; |
139 | } |
140 | |
141 | static 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 | |
152 | static 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 | |
158 | void udp_set_csum(bool nocheck, struct sk_buff *skb, |
159 | __be32 saddr, __be32 daddr, int len); |
160 | |
161 | static inline void (struct sk_buff *skb) |
162 | { |
163 | if (!skb->csum_valid && skb->ip_summed == CHECKSUM_NONE) |
164 | skb->csum = csum_partial(skb->data, sizeof(struct udphdr), |
165 | skb->csum); |
166 | skb_pull_rcsum(skb, sizeof(struct udphdr)); |
167 | UDP_SKB_CB(skb)->cscov -= sizeof(struct udphdr); |
168 | } |
169 | |
170 | typedef struct sock *(*udp_lookup_t)(struct sk_buff *skb, __be16 sport, |
171 | __be16 dport); |
172 | |
173 | struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, |
174 | struct udphdr *uh, udp_lookup_t lookup); |
175 | int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup); |
176 | |
177 | struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, |
178 | netdev_features_t features); |
179 | |
180 | static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb) |
181 | { |
182 | struct udphdr *uh; |
183 | unsigned int hlen, off; |
184 | |
185 | off = skb_gro_offset(skb); |
186 | hlen = off + sizeof(*uh); |
187 | uh = skb_gro_header_fast(skb, off); |
188 | if (skb_gro_header_hard(skb, hlen)) |
189 | uh = skb_gro_header_slow(skb, hlen, off); |
190 | |
191 | return uh; |
192 | } |
193 | |
194 | /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */ |
195 | static inline int udp_lib_hash(struct sock *sk) |
196 | { |
197 | BUG(); |
198 | return 0; |
199 | } |
200 | |
201 | void udp_lib_unhash(struct sock *sk); |
202 | void udp_lib_rehash(struct sock *sk, u16 new_hash); |
203 | |
204 | static inline void udp_lib_close(struct sock *sk, long timeout) |
205 | { |
206 | sk_common_release(sk); |
207 | } |
208 | |
209 | int udp_lib_get_port(struct sock *sk, unsigned short snum, |
210 | unsigned int hash2_nulladdr); |
211 | |
212 | u32 udp_flow_hashrnd(void); |
213 | |
214 | static inline __be16 udp_flow_src_port(struct net *net, struct sk_buff *skb, |
215 | int min, int max, bool use_eth) |
216 | { |
217 | u32 hash; |
218 | |
219 | if (min >= max) { |
220 | /* Use default range */ |
221 | inet_get_local_port_range(net, &min, &max); |
222 | } |
223 | |
224 | hash = skb_get_hash(skb); |
225 | if (unlikely(!hash)) { |
226 | if (use_eth) { |
227 | /* Can't find a normal hash, caller has indicated an |
228 | * Ethernet packet so use that to compute a hash. |
229 | */ |
230 | hash = jhash(skb->data, 2 * ETH_ALEN, |
231 | (__force u32) skb->protocol); |
232 | } else { |
233 | /* Can't derive any sort of hash for the packet, set |
234 | * to some consistent random value. |
235 | */ |
236 | hash = udp_flow_hashrnd(); |
237 | } |
238 | } |
239 | |
240 | /* Since this is being sent on the wire obfuscate hash a bit |
241 | * to minimize possbility that any useful information to an |
242 | * attacker is leaked. Only upper 16 bits are relevant in the |
243 | * computation for 16 bit port value. |
244 | */ |
245 | hash ^= hash << 16; |
246 | |
247 | return htons((((u64) hash * (max - min)) >> 32) + min); |
248 | } |
249 | |
250 | static inline int udp_rqueue_get(struct sock *sk) |
251 | { |
252 | return sk_rmem_alloc_get(sk) - READ_ONCE(udp_sk(sk)->forward_deficit); |
253 | } |
254 | |
255 | static inline bool udp_sk_bound_dev_eq(struct net *net, int bound_dev_if, |
256 | int dif, int sdif) |
257 | { |
258 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) |
259 | return inet_bound_dev_eq(!!net->ipv4.sysctl_udp_l3mdev_accept, |
260 | bound_dev_if, dif, sdif); |
261 | #else |
262 | return inet_bound_dev_eq(true, bound_dev_if, dif, sdif); |
263 | #endif |
264 | } |
265 | |
266 | /* net/ipv4/udp.c */ |
267 | void udp_destruct_sock(struct sock *sk); |
268 | void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len); |
269 | int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb); |
270 | void udp_skb_destructor(struct sock *sk, struct sk_buff *skb); |
271 | struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, |
272 | int noblock, int *peeked, int *off, int *err); |
273 | static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags, |
274 | int noblock, int *err) |
275 | { |
276 | int peeked, off = 0; |
277 | |
278 | return __skb_recv_udp(sk, flags, noblock, &peeked, &off, err); |
279 | } |
280 | |
281 | int udp_v4_early_demux(struct sk_buff *skb); |
282 | bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst); |
283 | int udp_get_port(struct sock *sk, unsigned short snum, |
284 | int (*saddr_cmp)(const struct sock *, |
285 | const struct sock *)); |
286 | int udp_err(struct sk_buff *, u32); |
287 | int udp_abort(struct sock *sk, int err); |
288 | int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len); |
289 | int udp_push_pending_frames(struct sock *sk); |
290 | void udp_flush_pending_frames(struct sock *sk); |
291 | int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size); |
292 | void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst); |
293 | int udp_rcv(struct sk_buff *skb); |
294 | int udp_ioctl(struct sock *sk, int cmd, unsigned long arg); |
295 | int udp_init_sock(struct sock *sk); |
296 | int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); |
297 | int __udp_disconnect(struct sock *sk, int flags); |
298 | int udp_disconnect(struct sock *sk, int flags); |
299 | __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait); |
300 | struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, |
301 | netdev_features_t features, |
302 | bool is_ipv6); |
303 | int udp_lib_getsockopt(struct sock *sk, int level, int optname, |
304 | char __user *optval, int __user *optlen); |
305 | int udp_lib_setsockopt(struct sock *sk, int level, int optname, |
306 | char __user *optval, unsigned int optlen, |
307 | int (*push_pending_frames)(struct sock *)); |
308 | struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, |
309 | __be32 daddr, __be16 dport, int dif); |
310 | struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, |
311 | __be32 daddr, __be16 dport, int dif, int sdif, |
312 | struct udp_table *tbl, struct sk_buff *skb); |
313 | struct sock *udp4_lib_lookup_skb(struct sk_buff *skb, |
314 | __be16 sport, __be16 dport); |
315 | struct sock *udp6_lib_lookup(struct net *net, |
316 | const struct in6_addr *saddr, __be16 sport, |
317 | const struct in6_addr *daddr, __be16 dport, |
318 | int dif); |
319 | struct sock *__udp6_lib_lookup(struct net *net, |
320 | const struct in6_addr *saddr, __be16 sport, |
321 | const struct in6_addr *daddr, __be16 dport, |
322 | int dif, int sdif, struct udp_table *tbl, |
323 | struct sk_buff *skb); |
324 | struct sock *udp6_lib_lookup_skb(struct sk_buff *skb, |
325 | __be16 sport, __be16 dport); |
326 | |
327 | /* UDP uses skb->dev_scratch to cache as much information as possible and avoid |
328 | * possibly multiple cache miss on dequeue() |
329 | */ |
330 | struct udp_dev_scratch { |
331 | /* skb->truesize and the stateless bit are embedded in a single field; |
332 | * do not use a bitfield since the compiler emits better/smaller code |
333 | * this way |
334 | */ |
335 | u32 _tsize_state; |
336 | |
337 | #if BITS_PER_LONG == 64 |
338 | /* len and the bit needed to compute skb_csum_unnecessary |
339 | * will be on cold cache lines at recvmsg time. |
340 | * skb->len can be stored on 16 bits since the udp header has been |
341 | * already validated and pulled. |
342 | */ |
343 | u16 len; |
344 | bool is_linear; |
345 | bool csum_unnecessary; |
346 | #endif |
347 | }; |
348 | |
349 | static inline struct udp_dev_scratch *udp_skb_scratch(struct sk_buff *skb) |
350 | { |
351 | return (struct udp_dev_scratch *)&skb->dev_scratch; |
352 | } |
353 | |
354 | #if BITS_PER_LONG == 64 |
355 | static inline unsigned int udp_skb_len(struct sk_buff *skb) |
356 | { |
357 | return udp_skb_scratch(skb)->len; |
358 | } |
359 | |
360 | static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb) |
361 | { |
362 | return udp_skb_scratch(skb)->csum_unnecessary; |
363 | } |
364 | |
365 | static inline bool udp_skb_is_linear(struct sk_buff *skb) |
366 | { |
367 | return udp_skb_scratch(skb)->is_linear; |
368 | } |
369 | |
370 | #else |
371 | static inline unsigned int udp_skb_len(struct sk_buff *skb) |
372 | { |
373 | return skb->len; |
374 | } |
375 | |
376 | static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb) |
377 | { |
378 | return skb_csum_unnecessary(skb); |
379 | } |
380 | |
381 | static inline bool udp_skb_is_linear(struct sk_buff *skb) |
382 | { |
383 | return !skb_is_nonlinear(skb); |
384 | } |
385 | #endif |
386 | |
387 | static inline int copy_linear_skb(struct sk_buff *skb, int len, int off, |
388 | struct iov_iter *to) |
389 | { |
390 | int n; |
391 | |
392 | n = copy_to_iter(skb->data + off, len, to); |
393 | if (n == len) |
394 | return 0; |
395 | |
396 | iov_iter_revert(to, n); |
397 | return -EFAULT; |
398 | } |
399 | |
400 | /* |
401 | * SNMP statistics for UDP and UDP-Lite |
402 | */ |
403 | #define UDP_INC_STATS(net, field, is_udplite) do { \ |
404 | if (is_udplite) SNMP_INC_STATS((net)->mib.udplite_statistics, field); \ |
405 | else SNMP_INC_STATS((net)->mib.udp_statistics, field); } while(0) |
406 | #define __UDP_INC_STATS(net, field, is_udplite) do { \ |
407 | if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_statistics, field); \ |
408 | else __SNMP_INC_STATS((net)->mib.udp_statistics, field); } while(0) |
409 | |
410 | #define __UDP6_INC_STATS(net, field, is_udplite) do { \ |
411 | if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_stats_in6, field);\ |
412 | else __SNMP_INC_STATS((net)->mib.udp_stats_in6, field); \ |
413 | } while(0) |
414 | #define UDP6_INC_STATS(net, field, __lite) do { \ |
415 | if (__lite) SNMP_INC_STATS((net)->mib.udplite_stats_in6, field); \ |
416 | else SNMP_INC_STATS((net)->mib.udp_stats_in6, field); \ |
417 | } while(0) |
418 | |
419 | #if IS_ENABLED(CONFIG_IPV6) |
420 | #define __UDPX_MIB(sk, ipv4) \ |
421 | ({ \ |
422 | ipv4 ? (IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_statistics : \ |
423 | sock_net(sk)->mib.udp_statistics) : \ |
424 | (IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_stats_in6 : \ |
425 | sock_net(sk)->mib.udp_stats_in6); \ |
426 | }) |
427 | #else |
428 | #define __UDPX_MIB(sk, ipv4) \ |
429 | ({ \ |
430 | IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_statistics : \ |
431 | sock_net(sk)->mib.udp_statistics; \ |
432 | }) |
433 | #endif |
434 | |
435 | #define __UDPX_INC_STATS(sk, field) \ |
436 | __SNMP_INC_STATS(__UDPX_MIB(sk, (sk)->sk_family == AF_INET), field) |
437 | |
438 | #ifdef CONFIG_PROC_FS |
439 | struct udp_seq_afinfo { |
440 | sa_family_t family; |
441 | struct udp_table *udp_table; |
442 | }; |
443 | |
444 | struct udp_iter_state { |
445 | struct seq_net_private p; |
446 | int bucket; |
447 | }; |
448 | |
449 | void *udp_seq_start(struct seq_file *seq, loff_t *pos); |
450 | void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos); |
451 | void udp_seq_stop(struct seq_file *seq, void *v); |
452 | |
453 | extern const struct seq_operations udp_seq_ops; |
454 | extern const struct seq_operations udp6_seq_ops; |
455 | |
456 | int udp4_proc_init(void); |
457 | void udp4_proc_exit(void); |
458 | #endif /* CONFIG_PROC_FS */ |
459 | |
460 | int udpv4_offload_init(void); |
461 | |
462 | void udp_init(void); |
463 | |
464 | DECLARE_STATIC_KEY_FALSE(udp_encap_needed_key); |
465 | void udp_encap_enable(void); |
466 | #if IS_ENABLED(CONFIG_IPV6) |
467 | DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key); |
468 | void udpv6_encap_enable(void); |
469 | #endif |
470 | |
471 | static inline struct sk_buff *udp_rcv_segment(struct sock *sk, |
472 | struct sk_buff *skb, bool ipv4) |
473 | { |
474 | struct sk_buff *segs; |
475 | |
476 | /* the GSO CB lays after the UDP one, no need to save and restore any |
477 | * CB fragment |
478 | */ |
479 | segs = __skb_gso_segment(skb, NETIF_F_SG, false); |
480 | if (unlikely(IS_ERR_OR_NULL(segs))) { |
481 | int segs_nr = skb_shinfo(skb)->gso_segs; |
482 | |
483 | atomic_add(segs_nr, &sk->sk_drops); |
484 | SNMP_ADD_STATS(__UDPX_MIB(sk, ipv4), UDP_MIB_INERRORS, segs_nr); |
485 | kfree_skb(skb); |
486 | return NULL; |
487 | } |
488 | |
489 | consume_skb(skb); |
490 | return segs; |
491 | } |
492 | |
493 | #endif /* _UDP_H */ |
494 | |