/* * INET		An implementation of the TCP/IP protocol suite for the LINUX *		operating system.  INET is implemented using the  BSD Socket *		interface as the means of communication with the user level. * *		Definitions for the UDP module. * * Version:	@(#)udp.h	1.0.2	05/07/93 * * Authors:	Ross Biro *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> * * Fixes: *		Alan Cox	: Turned on udp checksums. I don't want to *				  chase 'memory corruption' bugs that aren't! * *		This program is free software; you can redistribute it and/or *		modify it under the terms of the GNU General Public License *		as published by the Free Software Foundation; either version *		2 of the License, or (at your option) any later version. */#ifndef _UDP_H#define _UDP_H #include <linux/list.h>#include <linux/bug.h>#include <net/inet_sock.h>#include <net/sock.h>#include <net/snmp.h>#include <net/ip.h>#include <linux/ipv6.h>#include <linux/seq_file.h>#include <linux/poll.h> /** *	struct udp_skb_cb  -  UDP(-Lite) private variables * *	@header:      private variables used by IPv4/IPv6 *	@cscov:       checksum coverage length (UDP-Lite only) *	@partial_cov: if set indicates partial csum coverage */struct udp_skb_cb {	union {		struct inet_skb_parm	h4;#if IS_ENABLED(CONFIG_IPV6)		struct inet6_skb_parm	h6;#endif	} header;	__u16		cscov;	__u8		partial_cov;};#define UDP_SKB_CB(__skb)	((struct udp_skb_cb *)((__skb)->cb)) /** *	struct udp_hslot - UDP hash slot * *	@head:	head of list of sockets *	@count:	number of sockets in 'head' list *	@lock:	spinlock protecting changes to head/count */struct udp_hslot {	struct hlist_head	head;	int			count;	spinlock_t		lock;} __attribute__((aligned(2 * sizeof(long)))); /** *	struct udp_table - UDP table * *	@hash:	hash table, sockets are hashed on (local port) *	@hash2:	hash table, sockets are hashed on (local port, local address) *	@mask:	number of slots in hash tables, minus 1 *	@log:	log2(number of slots in hash table) */struct udp_table {	struct udp_hslot	*hash;	struct udp_hslot	*hash2;	unsigned int		mask;	unsigned int		log;};extern struct udp_table udp_table;void udp_table_init(struct udp_table *, const char *);static inline struct udp_hslot *udp_hashslot(struct udp_table *table,					     struct net *net, unsigned int num){	return &table->hash[udp_hashfn(net, num, table->mask)];}/* * For secondary hash, net_hash_mix() is performed before calling * udp_hashslot2(), this explains difference with udp_hashslot() */static inline struct udp_hslot *udp_hashslot2(struct udp_table *table,					      unsigned int hash){	return &table->hash2[hash & table->mask];} extern struct proto udp_prot; extern atomic_long_t udp_memory_allocated; /* sysctl variables for udp */extern long sysctl_udp_mem[3];extern int sysctl_udp_rmem_min;extern int sysctl_udp_wmem_min; struct sk_buff; /* *	Generic checksumming routines for UDP(-Lite) v4 and v6 */static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb){	return (UDP_SKB_CB(skb)->cscov == skb->len ?		__skb_checksum_complete(skb) :		__skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov));} static inline int udp_lib_checksum_complete(struct sk_buff *skb){	return !skb_csum_unnecessary(skb) &&		__udp_lib_checksum_complete(skb);} /** * 	udp_csum_outgoing  -  compute UDPv4/v6 checksum over fragments * 	@sk: 	socket we are writing to * 	@skb: 	sk_buff containing the filled-in UDP header * 	        (checksum field must be zeroed out) */static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb){	__wsum csum = csum_partial(skb_transport_header(skb),				   sizeof(struct udphdr), 0);	skb_queue_walk(&sk->sk_write_queue, skb) {		csum = csum_add(csum, skb->csum);	}	return csum;} static inline __wsum udp_csum(struct sk_buff *skb){	__wsum csum = csum_partial(skb_transport_header(skb),				   sizeof(struct udphdr), skb->csum); 	for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) {		csum = csum_add(csum, skb->csum);	}	return csum;} static inline __sum16 udp_v4_check(int len, __be32 saddr,				   __be32 daddr, __wsum base){	return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base);} void udp_set_csum(bool nocheck, struct sk_buff *skb,		  __be32 saddr, __be32 daddr, int len); static inline void udp_csum_pull_header(struct sk_buff *skb){	if (!skb->csum_valid && skb->ip_summed == CHECKSUM_NONE)		skb->csum = csum_partial(skb->data, sizeof(struct udphdr),					 skb->csum);	skb_pull_rcsum(skb, sizeof(struct udphdr));	UDP_SKB_CB(skb)->cscov -= sizeof(struct udphdr);} typedef struct sock *(*udp_lookup_t)(struct sk_buff *skb, __be16 sport,				     __be16 dport); struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb,				 struct udphdr *uh, udp_lookup_t lookup);int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup); static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb){	struct udphdr *uh;	unsigned int hlen, off; 	off  = skb_gro_offset(skb);	hlen = off + sizeof(*uh);	uh   = skb_gro_header_fast(skb, off);	if (skb_gro_header_hard(skb, hlen))		uh = skb_gro_header_slow(skb, hlen, off); 	return uh;} /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */static inline int udp_lib_hash(struct sock *sk){	BUG();	return 0;} void udp_lib_unhash(struct sock *sk);void udp_lib_rehash(struct sock *sk, u16 new_hash); static inline void udp_lib_close(struct sock *sk, long timeout){	sk_common_release(sk);} int udp_lib_get_port(struct sock *sk, unsigned short snum,		     unsigned int hash2_nulladdr); u32 udp_flow_hashrnd(void); static inline __be16 udp_flow_src_port(struct net *net, struct sk_buff *skb,				       int min, int max, bool use_eth){	u32 hash; 	if (min >= max) {		/* Use default range */		inet_get_local_port_range(net, &min, &max);	} 	hash = skb_get_hash(skb);	if (unlikely(!hash)) {		if (use_eth) {			/* Can't find a normal hash, caller has indicated an			 * Ethernet packet so use that to compute a hash.			 */			hash = jhash(skb->data, 2 * ETH_ALEN,				     (__force u32) skb->protocol);		} else {			/* Can't derive any sort of hash for the packet, set			 * to some consistent random value.			 */			hash = udp_flow_hashrnd();		}	} 	/* Since this is being sent on the wire obfuscate hash a bit	 * to minimize possbility that any useful information to an	 * attacker is leaked. Only upper 16 bits are relevant in the	 * computation for 16 bit port value.	 */	hash ^= hash << 16; 	return htons((((u64) hash * (max - min)) >> 32) + min);} /* net/ipv4/udp.c */void udp_destruct_sock(struct sock *sk);void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len);int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb);void udp_skb_destructor(struct sock *sk, struct sk_buff *skb);struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,			       int noblock, int *peeked, int *off, int *err);static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags,					   int noblock, int *err){	int peeked, off = 0; 	return __skb_recv_udp(sk, flags, noblock, &peeked, &off, err);} void udp_v4_early_demux(struct sk_buff *skb);bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst);int udp_get_port(struct sock *sk, unsigned short snum,		 int (*saddr_cmp)(const struct sock *,				  const struct sock *));void udp_err(struct sk_buff *, u32);int udp_abort(struct sock *sk, int err);int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len);int udp_push_pending_frames(struct sock *sk);void udp_flush_pending_frames(struct sock *sk);void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst);int udp_rcv(struct sk_buff *skb);int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);int udp_init_sock(struct sock *sk);int __udp_disconnect(struct sock *sk, int flags);int udp_disconnect(struct sock *sk, int flags);unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait);struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,				       netdev_features_t features,				       bool is_ipv6);int udp_lib_getsockopt(struct sock *sk, int level, int optname,		       char __user *optval, int __user *optlen);int udp_lib_setsockopt(struct sock *sk, int level, int optname,		       char __user *optval, unsigned int optlen,		       int (*push_pending_frames)(struct sock *));struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,			     __be32 daddr, __be16 dport, int dif);struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,			       __be32 daddr, __be16 dport, int dif,			       struct udp_table *tbl, struct sk_buff *skb);struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,				 __be16 sport, __be16 dport);struct sock *udp6_lib_lookup(struct net *net,			     const struct in6_addr *saddr, __be16 sport,			     const struct in6_addr *daddr, __be16 dport,			     int dif);struct sock *__udp6_lib_lookup(struct net *net,			       const struct in6_addr *saddr, __be16 sport,			       const struct in6_addr *daddr, __be16 dport,			       int dif, struct udp_table *tbl,			       struct sk_buff *skb);struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,				 __be16 sport, __be16 dport); /* UDP uses skb->dev_scratch to cache as much information as possible and avoid * possibly multiple cache miss on dequeue() */struct udp_dev_scratch {	/* skb->truesize and the stateless bit are embedded in a single field;	 * do not use a bitfield since the compiler emits better/smaller code	 * this way	 */	u32 _tsize_state; #if BITS_PER_LONG == 64	/* len and the bit needed to compute skb_csum_unnecessary	 * will be on cold cache lines at recvmsg time.	 * skb->len can be stored on 16 bits since the udp header has been	 * already validated and pulled.	 */	u16 len;	bool is_linear;	bool csum_unnecessary;#endif}; static inline struct udp_dev_scratch *udp_skb_scratch(struct sk_buff *skb){	return (struct udp_dev_scratch *)&skb->dev_scratch;} #if BITS_PER_LONG == 64static inline unsigned int udp_skb_len(struct sk_buff *skb){	return udp_skb_scratch(skb)->len;} static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb){	return udp_skb_scratch(skb)->csum_unnecessary;} static inline bool udp_skb_is_linear(struct sk_buff *skb){	return udp_skb_scratch(skb)->is_linear;} #elsestatic inline unsigned int udp_skb_len(struct sk_buff *skb){	return skb->len;} static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb){	return skb_csum_unnecessary(skb);} static inline bool udp_skb_is_linear(struct sk_buff *skb){	return !skb_is_nonlinear(skb);}#endif static inline int copy_linear_skb(struct sk_buff *skb, int len, int off,				  struct iov_iter *to){	int n; 	n = copy_to_iter(skb->data + off, len, to);	if (n == len)		return 0; 	iov_iter_revert(to, n);	return -EFAULT;} /* * 	SNMP statistics for UDP and UDP-Lite */#define UDP_INC_STATS(net, field, is_udplite)		      do { \	if (is_udplite) SNMP_INC_STATS((net)->mib.udplite_statistics, field);       \	else		SNMP_INC_STATS((net)->mib.udp_statistics, field);  }  while(0)#define __UDP_INC_STATS(net, field, is_udplite) 	      do { \	if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_statistics, field);         \	else		__SNMP_INC_STATS((net)->mib.udp_statistics, field);    }  while(0) #define __UDP6_INC_STATS(net, field, is_udplite)	    do { \	if (is_udplite) __SNMP_INC_STATS((net)->mib.udplite_stats_in6, field);\	else		__SNMP_INC_STATS((net)->mib.udp_stats_in6, field);  \} while(0)#define UDP6_INC_STATS(net, field, __lite)		    do { \	if (__lite) SNMP_INC_STATS((net)->mib.udplite_stats_in6, field);  \	else	    SNMP_INC_STATS((net)->mib.udp_stats_in6, field);      \} while(0) #if IS_ENABLED(CONFIG_IPV6)#define __UDPX_INC_STATS(sk, field)					\do {									\	if ((sk)->sk_family == AF_INET)					\		__UDP_INC_STATS(sock_net(sk), field, 0);		\	else								\		__UDP6_INC_STATS(sock_net(sk), field, 0);		\} while (0)#else#define __UDPX_INC_STATS(sk, field) __UDP_INC_STATS(sock_net(sk), field, 0)#endif /* /proc */int udp_seq_open(struct inode *inode, struct file *file); struct udp_seq_afinfo {	char				*name;	sa_family_t			family;	struct udp_table		*udp_table;	const struct file_operations	*seq_fops;	struct seq_operations		seq_ops;}; struct udp_iter_state {	struct seq_net_private  p;	sa_family_t		family;	int			bucket;	struct udp_table	*udp_table;}; #ifdef CONFIG_PROC_FSint udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo); int udp4_proc_init(void);void udp4_proc_exit(void);#endif int udpv4_offload_init(void); void udp_init(void); void udp_encap_enable(void);#if IS_ENABLED(CONFIG_IPV6)void udpv6_encap_enable(void);#endif #endif	/* _UDP_H */