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v3.1
  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 <net/inet_sock.h>
 27#include <net/sock.h>
 28#include <net/snmp.h>
 29#include <net/ip.h>
 30#include <linux/ipv6.h>
 31#include <linux/seq_file.h>
 32#include <linux/poll.h>
 33
 34/**
 35 *	struct udp_skb_cb  -  UDP(-Lite) private variables
 36 *
 37 *	@header:      private variables used by IPv4/IPv6
 38 *	@cscov:       checksum coverage length (UDP-Lite only)
 39 *	@partial_cov: if set indicates partial csum coverage
 40 */
 41struct udp_skb_cb {
 42	union {
 43		struct inet_skb_parm	h4;
 44#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
 45		struct inet6_skb_parm	h6;
 46#endif
 47	} header;
 48	__u16		cscov;
 49	__u8		partial_cov;
 50};
 51#define UDP_SKB_CB(__skb)	((struct udp_skb_cb *)((__skb)->cb))
 52
 53/**
 54 *	struct udp_hslot - UDP hash slot
 55 *
 56 *	@head:	head of list of sockets
 57 *	@count:	number of sockets in 'head' list
 58 *	@lock:	spinlock protecting changes to head/count
 59 */
 60struct udp_hslot {
 61	struct hlist_nulls_head	head;
 62	int			count;
 63	spinlock_t		lock;
 64} __attribute__((aligned(2 * sizeof(long))));
 65
 66/**
 67 *	struct udp_table - UDP table
 68 *
 69 *	@hash:	hash table, sockets are hashed on (local port)
 70 *	@hash2:	hash table, sockets are hashed on (local port, local address)
 71 *	@mask:	number of slots in hash tables, minus 1
 72 *	@log:	log2(number of slots in hash table)
 73 */
 74struct udp_table {
 75	struct udp_hslot	*hash;
 76	struct udp_hslot	*hash2;
 77	unsigned int		mask;
 78	unsigned int		log;
 79};
 80extern struct udp_table udp_table;
 81extern void udp_table_init(struct udp_table *, const char *);
 82static inline struct udp_hslot *udp_hashslot(struct udp_table *table,
 83					     struct net *net, unsigned num)
 84{
 85	return &table->hash[udp_hashfn(net, num, table->mask)];
 86}
 87/*
 88 * For secondary hash, net_hash_mix() is performed before calling
 89 * udp_hashslot2(), this explains difference with udp_hashslot()
 90 */
 91static inline struct udp_hslot *udp_hashslot2(struct udp_table *table,
 92					      unsigned int hash)
 93{
 94	return &table->hash2[hash & table->mask];
 95}
 96
 97/* Note: this must match 'valbool' in sock_setsockopt */
 98#define UDP_CSUM_NOXMIT		1
 99
100/* Used by SunRPC/xprt layer. */
101#define UDP_CSUM_NORCV		2
102
103/* Default, as per the RFC, is to always do csums. */
104#define UDP_CSUM_DEFAULT	0
105
106extern struct proto udp_prot;
107
108extern atomic_long_t udp_memory_allocated;
109
110/* sysctl variables for udp */
111extern long sysctl_udp_mem[3];
112extern int sysctl_udp_rmem_min;
113extern int sysctl_udp_wmem_min;
114
115struct sk_buff;
116
117/*
118 *	Generic checksumming routines for UDP(-Lite) v4 and v6
119 */
120static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
121{
122	return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov);
 
 
123}
124
125static inline int udp_lib_checksum_complete(struct sk_buff *skb)
126{
127	return !skb_csum_unnecessary(skb) &&
128		__udp_lib_checksum_complete(skb);
129}
130
131/**
132 * 	udp_csum_outgoing  -  compute UDPv4/v6 checksum over fragments
133 * 	@sk: 	socket we are writing to
134 * 	@skb: 	sk_buff containing the filled-in UDP header
135 * 	        (checksum field must be zeroed out)
136 */
137static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
138{
139	__wsum csum = csum_partial(skb_transport_header(skb),
140				   sizeof(struct udphdr), 0);
141	skb_queue_walk(&sk->sk_write_queue, skb) {
142		csum = csum_add(csum, skb->csum);
143	}
144	return csum;
145}
146
147static inline __wsum udp_csum(struct sk_buff *skb)
148{
149	__wsum csum = csum_partial(skb_transport_header(skb),
150				   sizeof(struct udphdr), skb->csum);
151
152	for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) {
153		csum = csum_add(csum, skb->csum);
154	}
155	return csum;
156}
157
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
158/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
159static inline void udp_lib_hash(struct sock *sk)
160{
161	BUG();
 
162}
163
164extern void udp_lib_unhash(struct sock *sk);
165extern void udp_lib_rehash(struct sock *sk, u16 new_hash);
166
167static inline void udp_lib_close(struct sock *sk, long timeout)
168{
169	sk_common_release(sk);
170}
171
172extern int udp_lib_get_port(struct sock *sk, unsigned short snum,
173			    int (*)(const struct sock *,const struct sock *),
174			    unsigned int hash2_nulladdr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
175
176/* net/ipv4/udp.c */
177extern int udp_get_port(struct sock *sk, unsigned short snum,
178			int (*saddr_cmp)(const struct sock *,
179					 const struct sock *));
180extern void udp_err(struct sk_buff *, u32);
181extern int udp_sendmsg(struct kiocb *iocb, struct sock *sk,
182			    struct msghdr *msg, size_t len);
183extern void udp_flush_pending_frames(struct sock *sk);
184extern int udp_rcv(struct sk_buff *skb);
185extern int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
186extern int udp_disconnect(struct sock *sk, int flags);
187extern unsigned int udp_poll(struct file *file, struct socket *sock,
188			     poll_table *wait);
189extern int udp_lib_getsockopt(struct sock *sk, int level, int optname,
190			      char __user *optval, int __user *optlen);
191extern int udp_lib_setsockopt(struct sock *sk, int level, int optname,
192			      char __user *optval, unsigned int optlen,
193			      int (*push_pending_frames)(struct sock *));
194extern struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
195				    __be32 daddr, __be16 dport,
196				    int dif);
197extern struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
198				    const struct in6_addr *daddr, __be16 dport,
199				    int dif);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
200
201/*
202 * 	SNMP statistics for UDP and UDP-Lite
203 */
204#define UDP_INC_STATS_USER(net, field, is_udplite)	      do { \
205	if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field);       \
206	else		SNMP_INC_STATS_USER((net)->mib.udp_statistics, field);  }  while(0)
207#define UDP_INC_STATS_BH(net, field, is_udplite) 	      do { \
208	if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field);         \
209	else		SNMP_INC_STATS_BH((net)->mib.udp_statistics, field);    }  while(0)
210
211#define UDP6_INC_STATS_BH(net, field, is_udplite) 	    do { \
212	if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\
213	else		SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field);  \
214} while(0)
215#define UDP6_INC_STATS_USER(net, field, __lite)		    do { \
216	if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field);  \
217	else	    SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field);      \
218} while(0)
219
220#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
221#define UDPX_INC_STATS_BH(sk, field) \
222	do { \
223		if ((sk)->sk_family == AF_INET) \
224			UDP_INC_STATS_BH(sock_net(sk), field, 0); \
225		else \
226			UDP6_INC_STATS_BH(sock_net(sk), field, 0); \
227	} while (0);
228#else
229#define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0)
230#endif
231
232/* /proc */
 
 
233struct udp_seq_afinfo {
234	char			*name;
235	sa_family_t		family;
236	struct udp_table	*udp_table;
237	struct file_operations	seq_fops;
238	struct seq_operations	seq_ops;
239};
240
241struct udp_iter_state {
242	struct seq_net_private  p;
243	sa_family_t		family;
244	int			bucket;
245	struct udp_table	*udp_table;
246};
247
248#ifdef CONFIG_PROC_FS
249extern int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);
250extern void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo);
251
252extern int udp4_proc_init(void);
253extern void udp4_proc_exit(void);
254#endif
255
256extern void udp_init(void);
 
 
 
 
 
 
 
257
258extern int udp4_ufo_send_check(struct sk_buff *skb);
259extern struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, u32 features);
260#endif	/* _UDP_H */
v4.17
  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 */
 42struct 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 */
 61struct 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 */
 75struct udp_table {
 76	struct udp_hslot	*hash;
 77	struct udp_hslot	*hash2;
 78	unsigned int		mask;
 79	unsigned int		log;
 80};
 81extern struct udp_table udp_table;
 82void udp_table_init(struct udp_table *, const char *);
 83static 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 */
 92static inline struct udp_hslot *udp_hashslot2(struct udp_table *table,
 93					      unsigned int hash)
 94{
 95	return &table->hash2[hash & table->mask];
 96}
 97
 
 
 
 
 
 
 
 
 
 98extern struct proto udp_prot;
 99
100extern atomic_long_t udp_memory_allocated;
101
102/* sysctl variables for udp */
103extern long sysctl_udp_mem[3];
104extern int sysctl_udp_rmem_min;
105extern int sysctl_udp_wmem_min;
106
107struct sk_buff;
108
109/*
110 *	Generic checksumming routines for UDP(-Lite) v4 and v6
111 */
112static 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
119static 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 */
131static 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
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
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
161static inline void udp_csum_pull_header(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
170typedef struct sock *(*udp_lookup_t)(struct sk_buff *skb, __be16 sport,
171				     __be16 dport);
172
173struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb,
174				 struct udphdr *uh, udp_lookup_t lookup);
175int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup);
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
191/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
192static inline int udp_lib_hash(struct sock *sk)
193{
194	BUG();
195	return 0;
196}
197
198void udp_lib_unhash(struct sock *sk);
199void udp_lib_rehash(struct sock *sk, u16 new_hash);
200
201static inline void udp_lib_close(struct sock *sk, long timeout)
202{
203	sk_common_release(sk);
204}
205
206int udp_lib_get_port(struct sock *sk, unsigned short snum,
207		     unsigned int hash2_nulladdr);
208
209u32 udp_flow_hashrnd(void);
210
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);
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		}
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
247/* net/ipv4/udp.c */
248void udp_destruct_sock(struct sock *sk);
249void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len);
250int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb);
251void udp_skb_destructor(struct sock *sk, struct sk_buff *skb);
252struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
253			       int noblock, int *peeked, int *off, int *err);
254static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags,
255					   int noblock, int *err)
256{
257	int peeked, off = 0;
258
259	return __skb_recv_udp(sk, flags, noblock, &peeked, &off, err);
260}
261
262int udp_v4_early_demux(struct sk_buff *skb);
263bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst);
264int udp_get_port(struct sock *sk, unsigned short snum,
265		 int (*saddr_cmp)(const struct sock *,
266				  const struct sock *));
267void udp_err(struct sk_buff *, u32);
268int udp_abort(struct sock *sk, int err);
269int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len);
270int udp_push_pending_frames(struct sock *sk);
271void udp_flush_pending_frames(struct sock *sk);
272void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst);
273int udp_rcv(struct sk_buff *skb);
274int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
275int udp_init_sock(struct sock *sk);
276int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
277int __udp_disconnect(struct sock *sk, int flags);
278int udp_disconnect(struct sock *sk, int flags);
279__poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait);
280struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
281				       netdev_features_t features,
282				       bool is_ipv6);
283int udp_lib_getsockopt(struct sock *sk, int level, int optname,
284		       char __user *optval, int __user *optlen);
285int udp_lib_setsockopt(struct sock *sk, int level, int optname,
286		       char __user *optval, unsigned int optlen,
287		       int (*push_pending_frames)(struct sock *));
288struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
289			     __be32 daddr, __be16 dport, int dif);
290struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
291			       __be32 daddr, __be16 dport, int dif, int sdif,
292			       struct udp_table *tbl, struct sk_buff *skb);
293struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
294				 __be16 sport, __be16 dport);
295struct sock *udp6_lib_lookup(struct net *net,
296			     const struct in6_addr *saddr, __be16 sport,
297			     const struct in6_addr *daddr, __be16 dport,
298			     int dif);
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, int sdif, struct udp_table *tbl,
303			       struct sk_buff *skb);
304struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
305				 __be16 sport, __be16 dport);
306
307/* UDP uses skb->dev_scratch to cache as much information as possible and avoid
308 * possibly multiple cache miss on dequeue()
309 */
310struct udp_dev_scratch {
311	/* skb->truesize and the stateless bit are embedded in a single field;
312	 * do not use a bitfield since the compiler emits better/smaller code
313	 * this way
314	 */
315	u32 _tsize_state;
316
317#if BITS_PER_LONG == 64
318	/* len and the bit needed to compute skb_csum_unnecessary
319	 * will be on cold cache lines at recvmsg time.
320	 * skb->len can be stored on 16 bits since the udp header has been
321	 * already validated and pulled.
322	 */
323	u16 len;
324	bool is_linear;
325	bool csum_unnecessary;
326#endif
327};
328
329static inline struct udp_dev_scratch *udp_skb_scratch(struct sk_buff *skb)
330{
331	return (struct udp_dev_scratch *)&skb->dev_scratch;
332}
333
334#if BITS_PER_LONG == 64
335static inline unsigned int udp_skb_len(struct sk_buff *skb)
336{
337	return udp_skb_scratch(skb)->len;
338}
339
340static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)
341{
342	return udp_skb_scratch(skb)->csum_unnecessary;
343}
344
345static inline bool udp_skb_is_linear(struct sk_buff *skb)
346{
347	return udp_skb_scratch(skb)->is_linear;
348}
349
350#else
351static inline unsigned int udp_skb_len(struct sk_buff *skb)
352{
353	return skb->len;
354}
355
356static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)
357{
358	return skb_csum_unnecessary(skb);
359}
360
361static inline bool udp_skb_is_linear(struct sk_buff *skb)
362{
363	return !skb_is_nonlinear(skb);
364}
365#endif
366
367static inline int copy_linear_skb(struct sk_buff *skb, int len, int off,
368				  struct iov_iter *to)
369{
370	int n;
371
372	n = copy_to_iter(skb->data + off, len, to);
373	if (n == len)
374		return 0;
375
376	iov_iter_revert(to, n);
377	return -EFAULT;
378}
379
380/*
381 * 	SNMP statistics for UDP and UDP-Lite
382 */
383#define UDP_INC_STATS(net, field, is_udplite)		      do { \
384	if (is_udplite) SNMP_INC_STATS((net)->mib.udplite_statistics, field);       \
385	else		SNMP_INC_STATS((net)->mib.udp_statistics, field);  }  while(0)
386#define __UDP_INC_STATS(net, field, is_udplite) 	      do { \
387	if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_statistics, field);         \
388	else		__SNMP_INC_STATS((net)->mib.udp_statistics, field);    }  while(0)
389
390#define __UDP6_INC_STATS(net, field, is_udplite)	    do { \
391	if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_stats_in6, field);\
392	else		__SNMP_INC_STATS((net)->mib.udp_stats_in6, field);  \
393} while(0)
394#define UDP6_INC_STATS(net, field, __lite)		    do { \
395	if (__lite) SNMP_INC_STATS((net)->mib.udplite_stats_in6, field);  \
396	else	    SNMP_INC_STATS((net)->mib.udp_stats_in6, field);      \
397} while(0)
398
399#if IS_ENABLED(CONFIG_IPV6)
400#define __UDPX_INC_STATS(sk, field)					\
401do {									\
402	if ((sk)->sk_family == AF_INET)					\
403		__UDP_INC_STATS(sock_net(sk), field, 0);		\
404	else								\
405		__UDP6_INC_STATS(sock_net(sk), field, 0);		\
406} while (0)
407#else
408#define __UDPX_INC_STATS(sk, field) __UDP_INC_STATS(sock_net(sk), field, 0)
409#endif
410
411/* /proc */
412int udp_seq_open(struct inode *inode, struct file *file);
413
414struct udp_seq_afinfo {
415	char				*name;
416	sa_family_t			family;
417	struct udp_table		*udp_table;
418	const struct file_operations	*seq_fops;
419	struct seq_operations		seq_ops;
420};
421
422struct udp_iter_state {
423	struct seq_net_private  p;
424	sa_family_t		family;
425	int			bucket;
426	struct udp_table	*udp_table;
427};
428
429#ifdef CONFIG_PROC_FS
430int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);
431void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo);
432
433int udp4_proc_init(void);
434void udp4_proc_exit(void);
435#endif
436
437int udpv4_offload_init(void);
438
439void udp_init(void);
440
441void udp_encap_enable(void);
442#if IS_ENABLED(CONFIG_IPV6)
443void udpv6_encap_enable(void);
444#endif
445
 
 
446#endif	/* _UDP_H */