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/* SPDX-License-Identifier: GPL-2.0-or-later *//* * 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! */#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>#include <linux/indirect_call_wrapper.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)(const struct sk_buff *skb, __be16 sport,				     __be16 dport); INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,							   struct sk_buff *));INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp6_gro_receive(struct list_head *,							   struct sk_buff *));INDIRECT_CALLABLE_DECLARE(int udp6_gro_complete(struct sk_buff *, int));INDIRECT_CALLABLE_DECLARE(void udp_v6_early_demux(struct sk_buff *));INDIRECT_CALLABLE_DECLARE(int udpv6_rcv(struct sk_buff *)); struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,				struct udphdr *uh, struct sock *sk);int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup); struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,				  netdev_features_t features, bool is_ipv6); 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);} static inline int udp_rqueue_get(struct sock *sk){	return sk_rmem_alloc_get(sk) - READ_ONCE(udp_sk(sk)->forward_deficit);} static inline bool udp_sk_bound_dev_eq(struct net *net, int bound_dev_if,				       int dif, int sdif){#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)	return inet_bound_dev_eq(!!net->ipv4.sysctl_udp_l3mdev_accept,				 bound_dev_if, dif, sdif);#else	return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);#endif} /* 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 *off, int *err);static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags,					   int noblock, int *err){	int off = 0; 	return __skb_recv_udp(sk, flags, noblock, &off, err);} int 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 *));int 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);int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size);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_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);int __udp_disconnect(struct sock *sk, int flags);int udp_disconnect(struct sock *sk, int flags);__poll_t 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,		       sockptr_t 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, int sdif,			       struct udp_table *tbl, struct sk_buff *skb);struct sock *udp4_lib_lookup_skb(const 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, int sdif, struct udp_table *tbl,			       struct sk_buff *skb);struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,				 __be16 sport, __be16 dport);int udp_read_sock(struct sock *sk, read_descriptor_t *desc,		  sk_read_actor_t recv_actor); /* 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_MIB(sk, ipv4)						\({									\	ipv4 ? (IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_statistics :	\				 sock_net(sk)->mib.udp_statistics) :	\		(IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_stats_in6 :	\				 sock_net(sk)->mib.udp_stats_in6);	\})#else#define __UDPX_MIB(sk, ipv4)						\({									\	IS_UDPLITE(sk) ? sock_net(sk)->mib.udplite_statistics :		\			 sock_net(sk)->mib.udp_statistics;		\})#endif #define __UDPX_INC_STATS(sk, field) \	__SNMP_INC_STATS(__UDPX_MIB(sk, (sk)->sk_family == AF_INET), field) #ifdef CONFIG_PROC_FSstruct udp_seq_afinfo {	sa_family_t			family;	struct udp_table		*udp_table;}; struct udp_iter_state {	struct seq_net_private  p;	int			bucket;	struct udp_seq_afinfo	*bpf_seq_afinfo;}; void *udp_seq_start(struct seq_file *seq, loff_t *pos);void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos);void udp_seq_stop(struct seq_file *seq, void *v); extern const struct seq_operations udp_seq_ops;extern const struct seq_operations udp6_seq_ops; int udp4_proc_init(void);void udp4_proc_exit(void);#endif /* CONFIG_PROC_FS */ int udpv4_offload_init(void); void udp_init(void); DECLARE_STATIC_KEY_FALSE(udp_encap_needed_key);void udp_encap_enable(void);void udp_encap_disable(void);#if IS_ENABLED(CONFIG_IPV6)DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key);void udpv6_encap_enable(void);#endif static inline struct sk_buff *udp_rcv_segment(struct sock *sk,					      struct sk_buff *skb, bool ipv4){	netdev_features_t features = NETIF_F_SG;	struct sk_buff *segs; 	/* Avoid csum recalculation by skb_segment unless userspace explicitly	 * asks for the final checksum values	 */	if (!inet_get_convert_csum(sk))		features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM; 	/* UDP segmentation expects packets of type CHECKSUM_PARTIAL or	 * CHECKSUM_NONE in __udp_gso_segment. UDP GRO indeed builds partial	 * packets in udp_gro_complete_segment. As does UDP GSO, verified by	 * udp_send_skb. But when those packets are looped in dev_loopback_xmit	 * their ip_summed is set to CHECKSUM_UNNECESSARY. Reset in this	 * specific case, where PARTIAL is both correct and required.	 */	if (skb->pkt_type == PACKET_LOOPBACK)

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