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.
6 * Definitions for the UDP module.
8 * Version: @(#)udp.h 1.0.2 05/07/93
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
14 * Alan Cox : Turned on udp checksums. I don't want to
15 * chase 'memory corruption' bugs that aren't!
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.
25 #include <linux/list.h>
26 #include <linux/bug.h>
27 #include <net/inet_sock.h>
31 #include <linux/ipv6.h>
32 #include <linux/seq_file.h>
33 #include <linux/poll.h>
36 * struct udp_skb_cb - UDP(-Lite) private variables
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
44 struct inet_skb_parm h4;
45 #if IS_ENABLED(CONFIG_IPV6)
46 struct inet6_skb_parm h6;
52 #define UDP_SKB_CB(__skb) ((struct udp_skb_cb *)((__skb)->cb))
55 * struct udp_hslot - UDP hash slot
57 * @head: head of list of sockets
58 * @count: number of sockets in 'head' list
59 * @lock: spinlock protecting changes to head/count
62 struct hlist_head head;
65 } __attribute__((aligned(2 * sizeof(long))));
68 * struct udp_table - UDP table
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)
76 struct udp_hslot *hash;
77 struct udp_hslot *hash2;
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)
86 return &table->hash[udp_hashfn(net, num, table->mask)];
89 * For secondary hash, net_hash_mix() is performed before calling
90 * udp_hashslot2(), this explains difference with udp_hashslot()
92 static inline struct udp_hslot *udp_hashslot2(struct udp_table *table,
95 return &table->hash2[hash & table->mask];
98 extern struct proto udp_prot;
100 extern atomic_long_t udp_memory_allocated;
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;
110 * Generic checksumming routines for UDP(-Lite) v4 and v6
112 static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
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));
119 static inline int udp_lib_checksum_complete(struct sk_buff *skb)
121 return !skb_csum_unnecessary(skb) &&
122 __udp_lib_checksum_complete(skb);
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)
131 static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
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);
141 static inline __wsum udp_csum(struct sk_buff *skb)
143 __wsum csum = csum_partial(skb_transport_header(skb),
144 sizeof(struct udphdr), skb->csum);
146 for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) {
147 csum = csum_add(csum, skb->csum);
152 static inline __sum16 udp_v4_check(int len, __be32 saddr,
153 __be32 daddr, __wsum base)
155 return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base);
158 void udp_set_csum(bool nocheck, struct sk_buff *skb,
159 __be32 saddr, __be32 daddr, int len);
161 static inline void udp_csum_pull_header(struct sk_buff *skb)
163 if (!skb->csum_valid && skb->ip_summed == CHECKSUM_NONE)
164 skb->csum = csum_partial(skb->data, sizeof(struct udphdr),
166 skb_pull_rcsum(skb, sizeof(struct udphdr));
167 UDP_SKB_CB(skb)->cscov -= sizeof(struct udphdr);
170 typedef struct sock *(*udp_lookup_t)(struct sk_buff *skb, __be16 sport,
173 struct sk_buff **udp_gro_receive(struct sk_buff **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);
177 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
178 netdev_features_t features,
181 static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb)
184 unsigned int hlen, off;
186 off = skb_gro_offset(skb);
187 hlen = off + sizeof(*uh);
188 uh = skb_gro_header_fast(skb, off);
189 if (skb_gro_header_hard(skb, hlen))
190 uh = skb_gro_header_slow(skb, hlen, off);
195 /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
196 static inline int udp_lib_hash(struct sock *sk)
202 void udp_lib_unhash(struct sock *sk);
203 void udp_lib_rehash(struct sock *sk, u16 new_hash);
205 static inline void udp_lib_close(struct sock *sk, long timeout)
207 sk_common_release(sk);
210 int udp_lib_get_port(struct sock *sk, unsigned short snum,
211 unsigned int hash2_nulladdr);
213 u32 udp_flow_hashrnd(void);
215 static inline __be16 udp_flow_src_port(struct net *net, struct sk_buff *skb,
216 int min, int max, bool use_eth)
221 /* Use default range */
222 inet_get_local_port_range(net, &min, &max);
225 hash = skb_get_hash(skb);
226 if (unlikely(!hash)) {
228 /* Can't find a normal hash, caller has indicated an
229 * Ethernet packet so use that to compute a hash.
231 hash = jhash(skb->data, 2 * ETH_ALEN,
232 (__force u32) skb->protocol);
234 /* Can't derive any sort of hash for the packet, set
235 * to some consistent random value.
237 hash = udp_flow_hashrnd();
241 /* Since this is being sent on the wire obfuscate hash a bit
242 * to minimize possbility that any useful information to an
243 * attacker is leaked. Only upper 16 bits are relevant in the
244 * computation for 16 bit port value.
248 return htons((((u64) hash * (max - min)) >> 32) + min);
252 void udp_destruct_sock(struct sock *sk);
253 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len);
254 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb);
255 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb);
256 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
257 int noblock, int *peeked, int *off, int *err);
258 static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags,
259 int noblock, int *err)
263 return __skb_recv_udp(sk, flags, noblock, &peeked, &off, err);
266 int udp_v4_early_demux(struct sk_buff *skb);
267 bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst);
268 int udp_get_port(struct sock *sk, unsigned short snum,
269 int (*saddr_cmp)(const struct sock *,
270 const struct sock *));
271 void udp_err(struct sk_buff *, u32);
272 int udp_abort(struct sock *sk, int err);
273 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len);
274 int udp_push_pending_frames(struct sock *sk);
275 void udp_flush_pending_frames(struct sock *sk);
276 int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size);
277 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst);
278 int udp_rcv(struct sk_buff *skb);
279 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
280 int udp_init_sock(struct sock *sk);
281 int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
282 int __udp_disconnect(struct sock *sk, int flags);
283 int udp_disconnect(struct sock *sk, int flags);
284 __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait);
285 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
286 netdev_features_t features,
288 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
289 char __user *optval, int __user *optlen);
290 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
291 char __user *optval, unsigned int optlen,
292 int (*push_pending_frames)(struct sock *));
293 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
294 __be32 daddr, __be16 dport, int dif);
295 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
296 __be32 daddr, __be16 dport, int dif, int sdif,
297 struct udp_table *tbl, struct sk_buff *skb);
298 struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
299 __be16 sport, __be16 dport);
300 struct sock *udp6_lib_lookup(struct net *net,
301 const struct in6_addr *saddr, __be16 sport,
302 const struct in6_addr *daddr, __be16 dport,
304 struct sock *__udp6_lib_lookup(struct net *net,
305 const struct in6_addr *saddr, __be16 sport,
306 const struct in6_addr *daddr, __be16 dport,
307 int dif, int sdif, struct udp_table *tbl,
308 struct sk_buff *skb);
309 struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
310 __be16 sport, __be16 dport);
312 /* UDP uses skb->dev_scratch to cache as much information as possible and avoid
313 * possibly multiple cache miss on dequeue()
315 struct udp_dev_scratch {
316 /* skb->truesize and the stateless bit are embedded in a single field;
317 * do not use a bitfield since the compiler emits better/smaller code
322 #if BITS_PER_LONG == 64
323 /* len and the bit needed to compute skb_csum_unnecessary
324 * will be on cold cache lines at recvmsg time.
325 * skb->len can be stored on 16 bits since the udp header has been
326 * already validated and pulled.
330 bool csum_unnecessary;
334 static inline struct udp_dev_scratch *udp_skb_scratch(struct sk_buff *skb)
336 return (struct udp_dev_scratch *)&skb->dev_scratch;
339 #if BITS_PER_LONG == 64
340 static inline unsigned int udp_skb_len(struct sk_buff *skb)
342 return udp_skb_scratch(skb)->len;
345 static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)
347 return udp_skb_scratch(skb)->csum_unnecessary;
350 static inline bool udp_skb_is_linear(struct sk_buff *skb)
352 return udp_skb_scratch(skb)->is_linear;
356 static inline unsigned int udp_skb_len(struct sk_buff *skb)
361 static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)
363 return skb_csum_unnecessary(skb);
366 static inline bool udp_skb_is_linear(struct sk_buff *skb)
368 return !skb_is_nonlinear(skb);
372 static inline int copy_linear_skb(struct sk_buff *skb, int len, int off,
377 n = copy_to_iter(skb->data + off, len, to);
381 iov_iter_revert(to, n);
386 * SNMP statistics for UDP and UDP-Lite
388 #define UDP_INC_STATS(net, field, is_udplite) do { \
389 if (is_udplite) SNMP_INC_STATS((net)->mib.udplite_statistics, field); \
390 else SNMP_INC_STATS((net)->mib.udp_statistics, field); } while(0)
391 #define __UDP_INC_STATS(net, field, is_udplite) do { \
392 if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_statistics, field); \
393 else __SNMP_INC_STATS((net)->mib.udp_statistics, field); } while(0)
395 #define __UDP6_INC_STATS(net, field, is_udplite) do { \
396 if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_stats_in6, field);\
397 else __SNMP_INC_STATS((net)->mib.udp_stats_in6, field); \
399 #define UDP6_INC_STATS(net, field, __lite) do { \
400 if (__lite) SNMP_INC_STATS((net)->mib.udplite_stats_in6, field); \
401 else SNMP_INC_STATS((net)->mib.udp_stats_in6, field); \
404 #if IS_ENABLED(CONFIG_IPV6)
405 #define __UDPX_INC_STATS(sk, field) \
407 if ((sk)->sk_family == AF_INET) \
408 __UDP_INC_STATS(sock_net(sk), field, 0); \
410 __UDP6_INC_STATS(sock_net(sk), field, 0); \
413 #define __UDPX_INC_STATS(sk, field) __UDP_INC_STATS(sock_net(sk), field, 0)
417 int udp_seq_open(struct inode *inode, struct file *file);
419 struct udp_seq_afinfo {
422 struct udp_table *udp_table;
423 const struct file_operations *seq_fops;
424 struct seq_operations seq_ops;
427 struct udp_iter_state {
428 struct seq_net_private p;
431 struct udp_table *udp_table;
434 #ifdef CONFIG_PROC_FS
435 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);
436 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo);
438 int udp4_proc_init(void);
439 void udp4_proc_exit(void);
442 int udpv4_offload_init(void);
446 void udp_encap_enable(void);
447 #if IS_ENABLED(CONFIG_IPV6)
448 void udpv6_encap_enable(void);