text: /*
   * NET		An implementation of the SOCKET network access protocol.
   *		This is the master header file for the Linux NET layer,
   *		or, in plain English: the networking handling part of the
   *		kernel.
   *
   * Version:	@(#)net.h	1.0.3	05/25/93
   *
   * Authors:	Orest Zborowski, <obz@Kodak.COM>
   *		Ross Biro
   *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   *
   *		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 _LINUX_NET_H
  #define _LINUX_NET_H
  
  #include <linux/stringify.h>
  #include <linux/random.h>
  #include <linux/wait.h>
  #include <linux/fcntl.h>	/* For O_CLOEXEC and O_NONBLOCK */
  #include <linux/kmemcheck.h>
  #include <linux/rcupdate.h>
  #include <linux/once.h>
  #include <linux/fs.h>
  
  #include <uapi/linux/net.h>
  
  struct poll_table_struct;
  struct pipe_inode_info;
  struct inode;
  struct file;
  struct net;
  
  /* Historically, SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA were located
   * in sock->flags, but moved into sk->sk_wq->flags to be RCU protected.
   * Eventually all flags will be in sk->sk_wq_flags.
   */
  #define SOCKWQ_ASYNC_NOSPACE	0
  #define SOCKWQ_ASYNC_WAITDATA	1
  #define SOCK_NOSPACE		2
  #define SOCK_PASSCRED		3
  #define SOCK_PASSSEC		4
  
  #ifndef ARCH_HAS_SOCKET_TYPES
  /**
   * enum sock_type - Socket types
   * @SOCK_STREAM: stream (connection) socket
   * @SOCK_DGRAM: datagram (conn.less) socket
   * @SOCK_RAW: raw socket
   * @SOCK_RDM: reliably-delivered message
   * @SOCK_SEQPACKET: sequential packet socket
   * @SOCK_DCCP: Datagram Congestion Control Protocol socket
   * @SOCK_PACKET: linux specific way of getting packets at the dev level.
   *		  For writing rarp and other similar things on the user level.
   *
   * When adding some new socket type please
   * grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS
   * overrides this enum for binary compat reasons.
   */
  enum sock_type {
  	SOCK_STREAM	= 1,
  	SOCK_DGRAM	= 2,
  	SOCK_RAW	= 3,
  	SOCK_RDM	= 4,
  	SOCK_SEQPACKET	= 5,
  	SOCK_DCCP	= 6,
  	SOCK_PACKET	= 10,
  };
  
  #define SOCK_MAX (SOCK_PACKET + 1)
  /* Mask which covers at least up to SOCK_MASK-1.  The
   * remaining bits are used as flags. */
  #define SOCK_TYPE_MASK 0xf
  
  /* Flags for socket, socketpair, accept4 */
  #define SOCK_CLOEXEC	O_CLOEXEC
  #ifndef SOCK_NONBLOCK
  #define SOCK_NONBLOCK	O_NONBLOCK
  #endif
  
  #endif /* ARCH_HAS_SOCKET_TYPES */
  
  enum sock_shutdown_cmd {
  	SHUT_RD,
  	SHUT_WR,
  	SHUT_RDWR,
  };
  
  struct socket_wq {
  	/* Note: wait MUST be first field of socket_wq */
  	wait_queue_head_t	wait;
  	struct fasync_struct	*fasync_list;
  	unsigned long		flags; /* %SOCKWQ_ASYNC_NOSPACE, etc */
  	struct rcu_head		rcu;
  } ____cacheline_aligned_in_smp;
  
  /**
   *  struct socket - general BSD socket
   *  @state: socket state (%SS_CONNECTED, etc)
   *  @type: socket type (%SOCK_STREAM, etc)
   *  @flags: socket flags (%SOCK_NOSPACE, etc)
   *  @ops: protocol specific socket operations
   *  @file: File back pointer for gc
   *  @sk: internal networking protocol agnostic socket representation
   *  @wq: wait queue for several uses
   */
  struct socket {
  	socket_state		state;
  
  	kmemcheck_bitfield_begin(type);
  	short			type;
  	kmemcheck_bitfield_end(type);
  
  	unsigned long		flags;
  
  	struct socket_wq __rcu	*wq;
  
  	struct file		*file;
  	struct sock		*sk;
  	const struct proto_ops	*ops;
  };
  
  struct vm_area_struct;
  struct page;
  struct sockaddr;
  struct msghdr;
  struct module;
  struct sk_buff;
  typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
  			       unsigned int, size_t);
  
  struct proto_ops {
  	int		family;
  	struct module	*owner;
  	int		(*release)   (struct socket *sock);
  	int		(*bind)	     (struct socket *sock,
  				      struct sockaddr *myaddr,
  				      int sockaddr_len);
  	int		(*connect)   (struct socket *sock,
  				      struct sockaddr *vaddr,
  				      int sockaddr_len, int flags);
  	int		(*socketpair)(struct socket *sock1,
  				      struct socket *sock2);
  	int		(*accept)    (struct socket *sock,
  				      struct socket *newsock, int flags, bool kern);
  	int		(*getname)   (struct socket *sock,
  				      struct sockaddr *addr,
  				      int *sockaddr_len, int peer);
  	unsigned int	(*poll)	     (struct file *file, struct socket *sock,
  				      struct poll_table_struct *wait);
  	int		(*ioctl)     (struct socket *sock, unsigned int cmd,
  				      unsigned long arg);
  #ifdef CONFIG_COMPAT
  	int	 	(*compat_ioctl) (struct socket *sock, unsigned int cmd,
  				      unsigned long arg);
  #endif
  	int		(*listen)    (struct socket *sock, int len);
  	int		(*shutdown)  (struct socket *sock, int flags);
  	int		(*setsockopt)(struct socket *sock, int level,
  				      int optname, char __user *optval, unsigned int optlen);
  	int		(*getsockopt)(struct socket *sock, int level,
  				      int optname, char __user *optval, int __user *optlen);
  #ifdef CONFIG_COMPAT
  	int		(*compat_setsockopt)(struct socket *sock, int level,
  				      int optname, char __user *optval, unsigned int optlen);
  	int		(*compat_getsockopt)(struct socket *sock, int level,
  				      int optname, char __user *optval, int __user *optlen);
  #endif
  	int		(*sendmsg)   (struct socket *sock, struct msghdr *m,
  				      size_t total_len);
  	/* Notes for implementing recvmsg:
  	 * ===============================
  	 * msg->msg_namelen should get updated by the recvmsg handlers
  	 * iff msg_name != NULL. It is by default 0 to prevent
  	 * returning uninitialized memory to user space.  The recvfrom
  	 * handlers can assume that msg.msg_name is either NULL or has
  	 * a minimum size of sizeof(struct sockaddr_storage).
  	 */
  	int		(*recvmsg)   (struct socket *sock, struct msghdr *m,
  				      size_t total_len, int flags);
  	int		(*mmap)	     (struct file *file, struct socket *sock,
  				      struct vm_area_struct * vma);
  	ssize_t		(*sendpage)  (struct socket *sock, struct page *page,
  				      int offset, size_t size, int flags);
  	ssize_t 	(*splice_read)(struct socket *sock,  loff_t *ppos,
  				       struct pipe_inode_info *pipe, size_t len, unsigned int flags);
  	int		(*set_peek_off)(struct sock *sk, int val);
  	int		(*peek_len)(struct socket *sock);
  	int		(*read_sock)(struct sock *sk, read_descriptor_t *desc,
  				     sk_read_actor_t recv_actor);
  };
  
  #define DECLARE_SOCKADDR(type, dst, src)	\
  	type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
  
  struct net_proto_family {
  	int		family;
  	int		(*create)(struct net *net, struct socket *sock,
  				  int protocol, int kern);
  	struct module	*owner;
  };
  
  struct iovec;
  struct kvec;
  
  enum {
  	SOCK_WAKE_IO,
  	SOCK_WAKE_WAITD,
  	SOCK_WAKE_SPACE,
  	SOCK_WAKE_URG,
  };
  
  int sock_wake_async(struct socket_wq *sk_wq, int how, int band);
  int sock_register(const struct net_proto_family *fam);
  void sock_unregister(int family);
  int __sock_create(struct net *net, int family, int type, int proto,
  		  struct socket **res, int kern);
  int sock_create(int family, int type, int proto, struct socket **res);
  int sock_create_kern(struct net *net, int family, int type, int proto, struct socket **res);
  int sock_create_lite(int family, int type, int proto, struct socket **res);
  struct socket *sock_alloc(void);
  void sock_release(struct socket *sock);
  int sock_sendmsg(struct socket *sock, struct msghdr *msg);
  int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
  struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
  struct socket *sockfd_lookup(int fd, int *err);
  struct socket *sock_from_file(struct file *file, int *err);
  #define		     sockfd_put(sock) fput(sock->file)
  int net_ratelimit(void);
  
  #define net_ratelimited_function(function, ...)			\
  do {								\
  	if (net_ratelimit())					\
  		function(__VA_ARGS__);				\
  } while (0)
  
  #define net_emerg_ratelimited(fmt, ...)				\
  	net_ratelimited_function(pr_emerg, fmt, ##__VA_ARGS__)
  #define net_alert_ratelimited(fmt, ...)				\
  	net_ratelimited_function(pr_alert, fmt, ##__VA_ARGS__)
  #define net_crit_ratelimited(fmt, ...)				\
  	net_ratelimited_function(pr_crit, fmt, ##__VA_ARGS__)
  #define net_err_ratelimited(fmt, ...)				\
  	net_ratelimited_function(pr_err, fmt, ##__VA_ARGS__)
  #define net_notice_ratelimited(fmt, ...)			\
  	net_ratelimited_function(pr_notice, fmt, ##__VA_ARGS__)
  #define net_warn_ratelimited(fmt, ...)				\
  	net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
  #define net_info_ratelimited(fmt, ...)				\
  	net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
  #if defined(CONFIG_DYNAMIC_DEBUG)
  #define net_dbg_ratelimited(fmt, ...)					\
  do {									\
  	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);			\
  	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) &&	\
  	    net_ratelimit())						\
  		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),		\
  		                   ##__VA_ARGS__);			\
  } while (0)
  #elif defined(DEBUG)
  #define net_dbg_ratelimited(fmt, ...)				\
  	net_ratelimited_function(pr_debug, fmt, ##__VA_ARGS__)
  #else
  #define net_dbg_ratelimited(fmt, ...)				\
  	do {							\
  		if (0)						\
  			no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
  	} while (0)
  #endif
  
  #define net_get_random_once(buf, nbytes)			\
  	get_random_once((buf), (nbytes))
  
  int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
  		   size_t num, size_t len);
  int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
  		   size_t num, size_t len, int flags);
  
  int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen);
  int kernel_listen(struct socket *sock, int backlog);
  int kernel_accept(struct socket *sock, struct socket **newsock, int flags);
  int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
  		   int flags);
  int kernel_getsockname(struct socket *sock, struct sockaddr *addr,
  		       int *addrlen);
  int kernel_getpeername(struct socket *sock, struct sockaddr *addr,
  		       int *addrlen);
  int kernel_getsockopt(struct socket *sock, int level, int optname, char *optval,
  		      int *optlen);
  int kernel_setsockopt(struct socket *sock, int level, int optname, char *optval,
  		      unsigned int optlen);
  int kernel_sendpage(struct socket *sock, struct page *page, int offset,
  		    size_t size, int flags);
  int kernel_sock_ioctl(struct socket *sock, int cmd, unsigned long arg);
  int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
  
  #define MODULE_ALIAS_NETPROTO(proto) \
  	MODULE_ALIAS("net-pf-" __stringify(proto))
  
  #define MODULE_ALIAS_NET_PF_PROTO(pf, proto) \
  	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto))
  
  #define MODULE_ALIAS_NET_PF_PROTO_TYPE(pf, proto, type) \
  	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
  		     "-type-" __stringify(type))
  
  #define MODULE_ALIAS_NET_PF_PROTO_NAME(pf, proto, name) \
  	MODULE_ALIAS("net-pf-" __stringify(pf) "-proto-" __stringify(proto) \
  		     name)
  #endif	/* _LINUX_NET_H */
  